ORCID Profile
0000-0002-6850-733X
Current Organisations
Zhejiang University
,
Hong Kong University of Science and Technology
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Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JHAZMAT.2018.11.047
Abstract: Highly efficient and cost-effective adsorbents for phosphate (P) recovery are the key to control eutrophication and recover phosphorus from waste streams to enhance food production. This study assembled corn stalk-derived biochar (BC) with various forms of layered double hydroxides (LDHs) (B-M-LDH) through simultaneous pyrolysis of waste biomass and metal (i.e., Zn/Al, Mg/Al, and Ni/Fe) hydroxide precipitates. Batch sorption experiments evaluated the kinetics and isotherms of phosphate adsorption as well as the influence of pH value and co-existing anions. Morphological characterization showed that crystalline LDH flakes were impregnated within the framework of fabricated B-M-LDH composites. Superior P adsorption capacity (152.1 mg (P) g
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JENVMAN.2019.04.041
Abstract: Engineered nanoparticles (NPs) are now used as additives in pesticides and fungicides and as novel fertilizers in agriculture so there is an urgent need to explore their effects on crop yield and quality in a full life cycle study. In the present study, three widely used NPs (TiO
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 09-2010
DOI: 10.1016/J.CHEMOSPHERE.2010.06.069
Abstract: The use of ethylenediaminetetraacetic acid (EDTA) for soil remediation is under concern due to its non-biodegradability and toxicity thus, its biodegradable structural isomer, [S,S]-ethylenediamine disuccinate ([S,S]-EDDS), has been proposed as an emerging substitute. In this study, batch experiments were performed to quantify the Pb extraction from goethite by EDTA and EDDS, respectively, and attenuated total reflectance-Fourier transform infrared (ATR/FT-IR) spectroscopy was used to investigate the corresponding mechanisms at the solid-liquid interface at different pH and reaction times. The Pb extraction was pH-dependent for both chelating agents mildly alkaline condition was favorable for EDDS, while mildly acidic condition for EDTA. The discrepancy between two structural isomers might be caused by their pH-dependent zwitterionic structures. The ATR/FT-IR results revealed that under acidic conditions, hydrogen-bonded carboxyl groups were present in both zwitterionic EDDS and EDTA. However, ring structure of zwitterionic EDDS formed with stable intramolecular hydrogen bond might limit the availability for EDDS to extract Pb from goethite. On the other hand, each protonated amine of zwitterionic EDTA could form hydrogen bonds with two neighbouring carboxyl groups, intensifying the negative charge of carboxyl groups and enhancing the Pb extraction efficiency. However, there was a higher amount of re-adsorption of PbEDTA than PbEDDS, because zwitterionic EDTA resulted in a greater Pb extraction and facilitated iron dissolution which significantly altered the goethite morphology, particle size, and surface area. These results suggested that, despite being structural isomers, EDDS and EDTA resulted in varying extents of Pb extraction and re-adsorption due to their different zwitterionic properties.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JHAZMAT.2018.11.042
Abstract: Compared to pyrolysis biochar (PBC), gasification biochar (GBC) differs in both composition and surface functionalities due to the use of an oxidizing purging gas. This work compares the effect of using PBC and GBC as soil amendments on the soil properties, trace metal bioavailability, soil microbial activity, and soil dissolved organic matter (DOM). Biochar-driven reduction of bioavailable metals does not necessarily result in a positive impact on the soil microbial growth. The DOM in the soil was strongly related to the soil microbial activity, as revealed by the strong correlation between the soil dehydrogenase activity (DHA) and soil dissolved organic carbon (r = 0.957, p < 0.01). Three identified fluorescent components (C1, C2, C3) in the soil DOM were closely associated with the soil microbial activity, for instance, with a clear positive correlation between the soil DHA and C1 (r = 0.718, p < 0.05) and a significant negative correlation between the total bacterial fatty acid methyl ester content and C3 (r = -0.768, p < 0.05). The bioavailability of Cd and Zn is not only related to the pH and surface functionalities of the biochar, but also to its aromatic carbon and inorganic mineral composition. This study further demonstrates that a fluorescence excitation-emission matrix coupled with parallel factor analysis is a useful tool to monitor changes in the soil quality after application of biochar, which is greatly relevant to the soil biota.
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.JHAZMAT.2019.121756
Abstract: Both thallium (Tl) and arsenic (As) bear severe toxicity. Brake fern (Pteris vittata L.) is well-known for its hyperaccumulation capacity of As, yet its role on Tl accumulation remains unknown. Herein, brake ferns growing near an As tailing site in Yunnan, Southwestern China are for the first time discovered as a co-hyperaccumulator of both Tl and As. The results showed that the brake ferns extracted both As and Tl efficiently from the soils into the fronds. The studied ferns growing on Tl and As co-polluted soils were found to accumulate extremely high levels of both As (7215-11110 mg/kg) and Tl (6.47-111 mg/kg). Conspicuously high bio-accumulation factor (BCF) was observed for As (7.8) and even higher for Tl (28.4) among these co-hyperaccumulators, wherein the contents of As and Tl in contaminated soils were 1240 ± 12 and 3.91 ± 0.01 mg/kg, respectively. The applied advanced characterization techniques (e.g. transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS)) indicated a preferential uptake of Tl(I) while simultaneous accumulation of As (III) and As(V) from the Tl(I)/Tl(III)-As (III)/As(V) co-existent rhizospheric soils. The findings benefit the phytoremediation practice and pose implications for managing and restoring Tl-As co-contaminated soils in other countries.
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.JENVMAN.2019.109542
Abstract: Microbial community is sensitive to the variations of environment, and it plays an important role in biogeochemical cycling in acid mine drainage (AMD). In this study, an integrated high-throughput absolute abundance quantification (iHAAQ) method was applied to study the dynamics of microbial community and the characteristics of microorganism. The results showed a significant difference in bacterial community with ersity being higher in watershed area. The main influential factors for bacterial communities in watershed were physicochemical properties (e.g., pH and potassium), while in mining areas the main driving factors were metals/metalloids (e.g., As, Zn, and Pb). Notably, the major functions of microbial community were transporter and ABC transporter in mining area, while two-component system was more abundant in watershed by the Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation analysis (level 3). In particular, Phyllobacterium, Bacteroides, and Sulfurovum were demonstrated to be potentially useful bacterial species for bioremediation, which should be a good choice for future studies. These results could facilitate our understanding of microbial ersity in different sediments of mining areas and identify microbial communities for bioremediation projects.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.JHAZMAT.2018.04.083
Abstract: To extract As bound to amorphous and crystalline iron oxides, this study proposed simultaneous application of oxalic acid and dithionite, which was observed to induce synergistic effect and accomplish effective extraction of As bound to both iron oxides. However, the formation of arsenic sulfide decreased overall removal of As because the insoluble precipitate form of As remained as a residual fraction of As in soil. Therefore, stepwise addition of dithionite in the simultaneous application was applied to minimize the formation of secondary minerals and maximize the As extraction. As a result, 74% of As bound to amorphous iron oxides and 65% of As bound to crystalline iron oxides were removed. More importantly, the stepwise application of oxalic acid and dithionite was effective to reduce the bioaccessible concentration of As in the treated soil. Therefore, the proposed application could reduce the potential risk of contaminated soil to human health by extraction-based remedial action.
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 11-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8GC00358K
Abstract: Propylene carbonate and γ-valerolactone prevent transformation of Sn 4+ (aq) into inactive SnO 2(s) , maintaining active Lewis acidity for glucose-to-fructose isomerisation.
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.BIORTECH.2018.10.068
Abstract: Hierarchical porous biochar derived from corn straw containing ternary needle-like iron-manganese-sulphur composites (Fe-Mn-S@HCS) are fabricated, and their physicochemical characteristics and performance for Pb removal were examined in detail. Introduction of Mn (transition metal) into Fe-biochar composites can effectively alter the chemical state of Fe simultaneous doping with S can enhance cation exchange for Pb removal. High uptake of Pb by Fe-Mn-S@HCS in a short time period was observed with the adsorption capacity of 181.5 mg g
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.CHEMOSPHERE.2017.11.023
Abstract: Chemical extraction of phosphorus (P) from incinerated sewage sludge ash (ISSA) is adversely influenced by co-dissolution of metals and metalloids. This study investigated P recovery and leaching of Zn, Cu, Pb, As and Ni from ISSA using inorganic acids (sulphuric acid and nitric acid), organic acids (oxalic acid and citric acid), and chelating agents (ethylenediaminetetraacetic acid (EDTA) and ethylene diamine tetramethylene phosphonate (EDTMP)). The aim of this study was to optimize a leaching process to recover P-leachate with high purity for P fertilizer production. The results show that both organic and inorganic acids extract P-containing phases but organic acids leach more trace elements, particularly Cu, Zn, Pb and As. Sulphuric acid was the most efficient for P recovery and achieved 94% of total extraction under the optimal conditions, which were 2-h reaction with 0.2 mol/L H
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.CHEMOSPHERE.2019.06.237
Abstract: Rice husk is a common agricultural waste. The utilization of rice husk biochar depends on the characteristics of biochar and its interaction mechanisms with heavy metals. In the present study, rice husk biochars at three different temperatures 300, 500, and 700 °C were produced (RH300, RH500, and RH700). The characteristics of these rice husk biochars and their interaction mechanisms with lead (Pb) were investigated, in order to reveal the potential environmental applications of the biochars. It was observed that the surface area (from 0.632 to 193.149 m
Publisher: Elsevier BV
Date: 06-2018
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.JHAZMAT.2021.127906
Abstract: Improving the recovery of organic matter and phosphorus (P) from hazardous biowastes such as swine manure using acidic substrates (ASs) in conjunction with aerobic composting is of great interest. This work aimed to investigate the effects of ASs on the humification and/or P migration as well as on microbial succession during the swine manure composting, employing multivariate and multiscale approaches. Adding ASs, derived from wood vinegar and humic acid, increased the degree of humification and thermal stability of the compost. The
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.SCITOTENV.2017.08.242
Abstract: Nitrogen (N) losses through gaseous emission of ammonia (NH
Publisher: American Chemical Society (ACS)
Date: 06-01-2009
DOI: 10.1021/ES8020292
Abstract: The effectiveness of biodegradable EDDS has aroused substantial interest over the past few years, yet there has been little information on the fate of metal-EDDS complexes that, prior to biodegradation, stay in contact with the soils. This study conducted 7-day batch experiments to investigate the kinetic interactions of CuEDDS(2-), ZnEDDS(2-), PbEDDS(2-), and AIEDDS(-), which are newly formed during EDDS application, with uncontaminated and metal-contaminated soils at pH 5.5 and 8. In uncontaminated soils, metal-EDDS complexes were adsorbed and induced mineral dissolution. In contaminated soils, on the contrary, significant metal exchange with sorbed metals on the soil surfaces (i.e., Cu, Zn, and Pb) resulted in a greater extent of metal resorption of the metal-EDDS complexes. The interactions of metal-EDDS complexes, moreover, are influenced by the characteristics of the metal center. Compared with ZnEDDS(2-) and PbEDDS(2-), CuEDDS(2-) was least adsorbed or exchanged, which may be attributed to higher ionic potential and the electron configuration of Cu. In addition, AIEDDS(-) was partially exchanged on the soil surfaces at low pH while entirely dissociated in solution at high pH. Therefore, the fate of in idual metal-EDDS complexes in the subsurface depends on the metal center, other sorbed metals and mineral cations on soils, and solution pH.
Publisher: American Chemical Society (ACS)
Date: 28-03-2019
Abstract: To study the mechanisms of chromium (Cr) mobilization in sediments of eutrophic lakes, monthly s ling was performed in the Meiliang Bay of Lake Taihu, China, combined with laboratory experiments. High-resolution dialysis and diffusive gradients in thin film (DGT) s ling techniques were used. Results indicated that in July 2016 and January 2017, the concentrations of soluble Cr and DGT-labile Cr(VI) in the overlying water exceeded both drinking and fishery water quality standards, resulting from the high mobility of Cr in sediments. In July (summer), the high concentration of soluble Cr (134.04 ± 7.20 μg/L) detected in the anaerobic sediments was primarily caused by the complexation of Cr(III) with dissolved organic matter (DOM). This mechanism was supported by an observed simultaneous increase of soluble Cr and DOM under simulated anaerobic conditions. In January (winter), the high concentrations of soluble Cr (97.55 ± 9.65 μg/L) and DGT-labile Cr(VI) (25.83 ± 1.25 μg/L) in aerobic sediments were primarily caused by reoxidation of Cr(III) by Mn(III/IV) oxides as evidenced by the lowest concentrations of soluble and DGT-labile Mn(II). This study sheds light on the full-year variation and mechanisms of Cr mobilization in eutrophic lake sediments and suggests the urgent need for remediation of Cr pollution especially for winter.
Publisher: Elsevier BV
Date: 2021
Publisher: Springer Science and Business Media LLC
Date: 19-02-2013
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 02-2020
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.SCITOTENV.2022.154341
Abstract: The addition of thermally conductive nanomaterials is an effective strategy for increasing the thermal conductivity of phase change materials (PCMs). However, nanomaterials are expensive and may significantly reduce the latent heat capacity of PCMs. In this study, low-cost and eco-friendly biochar microparticles were prepared from garlic stems, a common food waste in Singapore. The thermal properties of paraffin wax (PW) doped with 1, 3, and 5 wt% garlic stem biochar (GSB) microparticles were investigated. The GSB microparticles prepared at 700 °C had three-dimensional porous and two-dimensional flake-like structures, which contributed to the formation of additional heat transfer pathways in the PW. The addition of 5 wt% GSB microparticles enhanced the thermal conductivity of PW by 27.3% and 7.2% in the solid and liquid phases, respectively. The T-history test revealed that the melting and solidification rates of PW improved by 90 and 115 s, respectively. The improved heat transfer performance was mainly ascribed to the high degree of graphitization and the interconnected porous carbon structure of the GSB microparticles. The phase change temperatures of PW were slightly changed upon the addition of GSB microparticles, and the latent heat capacity was only reduced by 6.1%. These results suggest that the GSB microparticles can be used as a potential alternative to other nanoadditives such as metal- and metal oxide-based nanoadditives.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.ENVPOL.2017.01.044
Abstract: Produced water is a type of wastewater generated from hydraulic fracturing, which may pose a risk to the environment and humans due to its high ionic strength and the presence of elevated concentrations of metals/metalloids that exceed maximum contamination levels. The mobilization of As(V) and Se(VI) in produced water and selected soils from Qingshankou Formation in the Songliao Basin in China were investigated using column experiments and synthetic produced water whose quality was representative of waters arising at different times after well creation. Temporal effects of produced water on metal/metalloid transport and sorption/desorption were investigated by using HYDRUS-1D transport modelling. Rapid breakthrough and long tailings of As(V) and Se(VI) transport were observed in Day 1 and Day 14 solutions, but were reduced in Day 90 solution probably due to the elevated ionic strength. The influence of produced water on the hydrogeological conditions (i.e., change between equilibrium and non-equilibrium transport) was evidenced by the change of tracer breakthrough curves before and after the leaching of produced water. This possibly resulted from the sorption of polyacrylamide (PAM (-CH
Publisher: Elsevier BV
Date: 05-2022
DOI: 10.1016/J.ENVRES.2021.112179
Abstract: The accumulation of microplastics (MPs) and nanoplastics (NPs) in terrestrial and aquatic ecosystems has raised concerns because of their adverse effects on ecosystem functions and human health. Plastic waste management has become a universal problem in recent years. Hence, sustainable plastic waste management techniques are vital for achieving the United Nations Sustainable Development Goals. Although many reviews have focused on the occurrence and impact of micro- and nanoplastics (MNPs), there has been limited focus on the management of MNPs. This review first summarizes the ecotoxicological impacts of plastic waste sources and issues related to the sustainable management of MNPs in the environment. This paper then critically evaluates possible approaches for incorporating plastics into the circular economy in order to cope with the problem of plastics. Pollution associated with MNPs can be tackled through source reduction, incorporation of plastics into the circular economy, and suitable waste management. Appropriate infrastructure development, waste valorization, and economically sound plastic waste management techniques and viable alternatives are essential for reducing MNPs in the environment. Policymakers must pay more attention to this critical issue and implement appropriate environmental regulations to achieve environmental sustainability.
Publisher: American Chemical Society (ACS)
Date: 21-02-2018
Abstract: The progress in modern agricultural practices could not have been realized without the large-scale contribution of assorted pesticides (e.g., organophosphates and nonorganophosphates). Precise tracking of these chemicals has become very important for safeguarding the environment and food resources owing to their very high toxicity. Hence, the development of sensitive and convenient sensors for the on-site detection of pesticides is imperative to overcome practical limitations encountered in conventional methodologies, which require skilled manpower at the expense of high cost and low portability. In this regard, the role of novel, advanced functional materials such as metal-organic frameworks (MOFs) has drawn great interest as an alternative for conventional sensory systems because of their numerous advantages over other nanomaterials. This review was organized to address the recent advances in applications of MOFs for sensing various pesticides because of their tailorable optical and electrical characteristics. It also provides in-depth comparison of the performance of MOFs with other nanomaterial sensing platforms. Further, we discuss the present challenges (e.g., potential bias due to instability under certain conditions, variations in the diffusion rate of the pesticide, chemical interferences, and the precise measurement of luminesce quenching) in developing robust and sensitive sensors by using tailored porosity, functionalities, and better framework stability.
Publisher: American Chemical Society (ACS)
Date: 17-02-2023
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.SCITOTENV.2018.03.049
Abstract: Soil contamination by trace elements such as arsenic (As) can pose considerable threats to human health, and need to be carefully identified through site investigation before the soil remediation and development works. However, due to the high costs of soil s ling and testing, decisions on risk management or mitigation strategies are often based on limited data at the site, with substantial uncertainty in the spatial distributions of potentially toxic elements. This study incorporates the restricted maximum likelihood method with three-dimensional spatial autocovariance structure, to investigate the spatial variability features of As-containing soils of geogenic origin. A recent case study in Hong Kong is presented, where >550 s les were retrieved and tested for distributions of As concentrations. The proposed approach is applied to characterize their spatial correlation patterns, to predict the As concentrations at uns led locations, and to quantify the uncertainty of such estimates. The validity of the approach is illustrated by utilizing the multi-stage site investigation data, through which the advantages of the approach over traditional geostatistical methods are revealed and discussed. The new approach also quantifies the effectiveness of soil s ling on reduction of uncertainty levels across the site. This can become a useful indicator for risk management or mitigation strategies, as it is often necessary to balance between the available resources for soil s ling at the site and the needs for proper characterization of contaminant distributions.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9GC00734B
Abstract: Oxygen functionalities on GIO/GO are involved in the formation of active Al sites potentially with a microwave-absorbing ability, which facilitates glucose–fructose isomerisation in water.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 05-2020
Publisher: Informa UK Limited
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 25-01-2016
Publisher: Elsevier BV
Date: 02-2018
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.SCITOTENV.2018.02.247
Abstract: The low-alkalinity stabilization/solidification (S/S) treatment of the soil containing high concentrations of geogenic As by physical encapsulation is considered as a proper management before land development however, the choice of an effective binder and the leaching potential of As remain uncertain. In this study, the influence of S/S binders (cement blended with fuel ash (FA), furnace bottom ash (FBA), or ground granulated blast furnace slag (GGBS)) on the speciation and leaching characteristics of geogenic As was studied. The results of X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) showed the reduced amount of calcium silicate hydrate phase and the decrease in oxidation state of As(V)-O on the surface of Fe(III) oxides/hydroxides in the low-alkalinity S/S treated soils. This might be due to the binder incorporation and change in pH conditions, which slightly affected the As-Fe interaction and increased the non-specifically sorbed species of As. Therefore, the S/S treatment increased the leachability and bioaccessibility of geogenic As to varying degree but decreased the phyto-extractable As. The S/S treatment by cement incorporating 25% of class C fly ash (O4C1) could achieve comparable or better performance, while reducing the risk assessment code (RAC) to a greater extent compared to that of using cement only. This study illustrates the effectiveness and limitations of low-alkalinity binders (e.g., O4C1) for geogenic As immobilization and encapsulation, which provides a new insight for determining the appropriate S/S binder in soil remediation.
Publisher: Informa UK Limited
Date: 02-12-2017
Publisher: Elsevier BV
Date: 04-2019
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.SCITOTENV.2019.03.457
Abstract: China is facing a groundwater depletion and deterioration crisis, culminating from long-term over-exploitation and groundwater contamination. Aggravating factors include population growth, unprecedented urbanization and climate change. Sustainable groundwater management is called for, however, a valid means for a national-scale assessment of groundwater resource sustainability does not currently exist. Here we present a drivers-pressures-states-impact-response (DPSIR) assessment framework. Based on this framework, groundwater sustainability indices for mainland China's 31 provinces and municipalities were derived, with an average score of 59.5 out of 100, ranging from 47.3 for Tianjin to 72.9 for Tibet. We found that due to fewer Drivers and better States, groundwater resources in southern China are far more sustainable than those in the northern and eastern areas. An appraisal of subcategories shed light on the importance of affording attention to externalities such as societal, economic and environmental factors, which are interrelated as complex systems. Based on the assessment findings, implications for policy and decision-making suggestions for sustainable management of China's groundwater resources are put forward.
Publisher: Elsevier BV
Date: 05-2020
DOI: 10.1016/J.JHAZMAT.2019.121649
Abstract: Improving the sustainability and cost-effectiveness of biochar production is crucial to meet increased global market demand. Here, we developed a single-step microwave steam activation (STMSA) as a simplified yet efficient method to produce microwave activated biochar (MAB) from waste palm shell (WPS). The STMSA recorded a higher heating rate (70 °C/min) and higher conversion (45 wt%) of WPS into highly microporous MAB (micropore surface area of 679.22 m
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 06-2010
DOI: 10.1016/J.JHAZMAT.2010.02.021
Abstract: In situ biodegradable EDDS ([S,S]-stereoisomer of ethylenediaminedisuccinic acid) applications at low concentration may present conditions where applied EDDS is insufficient relative to sorbed metals in soils. This study investigated the influence of EDDS-to-metal molar ratios (MR), solution pH and soil-to-solution ratio on metal extraction under EDDS deficiency (i.e., MR<1). Batch kinetics experiments showed that Pb and Zn extraction exhibited different kinetic behaviors at MR 0.35-0.75, while Cu extraction was comparable. At MR 0.75 or below, newly extracted Pb was re-adsorbed onto the soil surfaces. Similar re-adsorption phenomenon, to a lower extent, was observed for newly extracted Zn at MR 0.5 or below, whereas this appeared to be marginal at MR 0.75, reflecting Zn extraction was less affected by EDDS deficiency than Pb extraction. Moreover, Pb extraction at an alkaline condition was preferable under EDDS deficiency because at MR 0.5 it was 30% higher at pH 8 and 9 than pH 5.5 and 7. The influence of varying soil-to-solution ratios (1:50-1:5) at MR 0.5 was marginal compared with that of MR and solution pH. These findings indicated that Pb extraction by deficient EDDS would be more difficult to accomplish compared to Cu and Zn extraction.
Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.JHAZMAT.2011.05.067
Abstract: This study evaluated the design of step-gradient, single-pulse, multi-pulse, and continuous injection of biodegradable EDDS ([S,S]-ethylene-diamine-disuccinic acid, under the same total dosage) and the significance of pore-water velocities during in situ soil flushing. In view of the metal breakthrough and extraction efficiency of each injection mode, single-pulse injection was found to be the least effective for all metals. Multi-pulse injection was consistently more effective than single-pulse injection, although the efficiency of second and third pulse injections significantly diminished. Continuous injection offered a simple operation and the greatest Ni and Cu extraction, whereas step-gradient injection was the best option for Zn and Pb extraction because it mitigated the influence of metal exchange. Moreover, a rinsing step with a background solution following the initial injection of the multi-pulse injection removed newly formed metal-EDDS complexes from soil pores effectively before further EDDS-flushing. A decrease in pore-water velocity provided a longer residence time for greater Ni and Cu extraction, but also enhanced the rate-limited metal exchange of Zn-EDDS and Pb-EDDS complexes and thus hindered Zn and Pb extraction. These results suggest a slower and continuous injection for the best Ni or Cu removal, but a faster and step-gradient injection for Zn or Pb removal.
Publisher: Elsevier BV
Date: 08-2019
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.SCITOTENV.2017.11.076
Abstract: The application of biochar (BC) as a filler in polymers can be viewed as a sustainable approach that incorporates pyrolysed waste based value-added material and simultaneously mitigate bio-waste in a smart way. The overarching aim of this work was to investigate the electrical, mechanical, thermal and rheological properties of biocomposite developed by utilizing date palm waste-derived BC for the reinforcing of polypropylene (PP) matrix. Date palm waste derived BC prepared at (700 and 900°C) were blended at different proportions with polypropylene and the resultant composites (BC/PP) were characterized using an array of techniques (scanning electron microscope, energy-dispersive X-ray spectroscopy and Fourier transform infra-red spectroscopy). Additionally the thermal, mechanical, electrical and rheological properties of the BC/PP composites were evaluated at different loading of BC content (from 0 to15% w/w). The mechanical properties of BC/PP composites showed an improvement in the tensile modulus while that of electrical characterization revealed an enhanced electrical conductivity with increased BC loading. Although the BC incorporation into the PP matrix has significantly reduced the total crystallinity of the resulted composites, however a positive effect on the crystallization temperature (T
Publisher: Elsevier BV
Date: 11-2019
Publisher: Springer Science and Business Media LLC
Date: 12-10-2012
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 10-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7RA04185C
Abstract: A multi-step chemical replication method using natural green leaves as templates can produce a porous, visible-light active TiO 2 -based photocatalyst.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.ENVINT.2019.01.076
Abstract: Thallium (Tl) is a typical toxic metal, which poses a great threat to human health through drinking water and the food chain (biomagnification). China has rich Tl-bearing mineral resources, which have been extensively explored and utilized, leading to release of large amounts of Tl into the environment. However, research on Tl pollution and removal techniques is relatively limited, because Tl has not been listed within the scope of environmental monitoring in China for several decades. This paper reviewed Tl pollution in wastewater arising from various industries in China, as well as the latest available methods for treating Tl-containing industrial wastewater, in order to give an outlook on effective technologies for controlling Tl pollution. Conventional physical and chemical treatment technologies are efficient at removing trace amounts of Tl, but it proved to be difficult to achieve the stringent environmental standard (≤0.1-5 μg/L) cost-effectively. Adsorption by using newly developed nanomaterials, and metal oxide modified polymer materials and microbial fuel cells are highly promising and expected to become next-generation technologies for remediation of Tl pollution. With the potential for greater Tl contamination in the environment under accelerated growth of industrialization, researches based on lab-scale implementation of such promising treatment technologies should be further expanded to pilot and industrial scale, ensuring environmental protection and the safety of drinking water for sustainable development. Comprehensive insights into experiences of Tl pollution in China and in-depth perspectives on new frontier technologies of Tl removal from wastewaters will also benefit other nations/regions worldwide, which are susceptible to high exposure to Tl likewise.
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.JHAZMAT.2019.05.098
Abstract: Biochar can act as "electron shuttle" in soil redox reactions. It is possible that biochar accepts the electrons from low molecular weight organic acids (LMWOAs) in soil and then transfer them to the acceptors, e.g., Cr(VI). This study evaluated the interaction between seven soil LMWOAs and peanut shell biochar (BC) as well as its effect on the electron shuttling of biochar for Cr(VI) reduction. Both redox reactions and sorption process occurred during the interaction of biochar and LMWOAs, which altered the contents of Cr(VI) reduction-relevant groups (i.e., CO and CO) on the surface of biochar. The redox reactions were more important to the electron transfer between biochar produced at 400℃ (BC400) and LMWOAs due to the repeated cycle of reduction-oxidation of surface functional groups. The reduction rate of Cr(VI) by LMWOAs mediated by BC400 was 1.10-7.09 × 10
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.BIORTECH.2018.09.027
Abstract: In this study, lignin was selected as the main component of waste biomass to synthesise carbonaceous adsorbents with environmentally persistent free radicals (EPFRs) through hydrothermal carbonisation (HTC) under different conditions. The HTC method with Fe(III) doping was superior for promoting dehydration and decarboxylation of lignin hydrochar than that with HTC Cu(II) doping. The deconstruction of oxygen-containing groups of lignin was reduced while esterification was enhanced by Fe(III). The Fe(III) addition was conducive to the formation of EPFRs as carbon-centred radicals with an adjacent oxygen atom and oxygen-centred radicals. A comparison of lignin with cellulose and d-xylose suggests that the formed EPFRs on lignin hydrochar were derived from their phenolic hydroxyl groups. A high removal efficiency of bisphenol A by lignin hydrochar was observed owing to oxygen-centred radicals, which activated H
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.SCITOTENV.2019.136080
Abstract: The application of pesticides reduces the loss of crops while simultaneously increasing crop productivity. However, the frequent use of pesticides can cause serious environmental problems due to their high accumulative and persistent nature. Recently, microalgae technology has received considerable success in the efficient treatment of pesticides pollution. In this review, the metabolic mechanisms responsible for the removal of pesticides are summarized based on previous studies. Different methods used to enhance the ability of microalgae to remove pesticides are critically evaluated. The recycling of microalgae biomass after wastewater treatment for biochar preparation and biodiesel production using the biorefinery approach is also introduced. Furthermore, we present potential future research directions to highlight the prospects of microalgae research in the removal of pesticides along with the production of value-added products.
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.SCITOTENV.2019.136079
Abstract: An effective adsorbent towards fluoroquinolone antibiotics was synthesized via a facile two-step approach, the co-precipitation of Fe, Mn with vinasse wastes and then pyrolysis under controlled conditions which denoted as FMB. Its adsorption behavior was examined based on a batch adsorption experiment of fluoroquinolone antibiotics pefloxacin (PEF) and ciprofloxacin (CIP). Experimental factors, such as pH, adsorbent dose, ionic strength, contact time and temperature have done a great deal to influence the adsorption of PEF and CIP. The FMB demonstrated excellent performance in reusability tests towards to both PEF and CIP, which showed that the recycling efficiency of PEF and CIP could remain ~55% and ~80% after five recycle cycles, respectively. The dominated adsorption mechanisms included pore filling effect, π-π stacking interaction, π-π EDA, hydrogen bonding and hydrophobicity. Overall, this work presented FMB was recognized as an effective, environmental-friendly and magnetically separable adsorbent for alleviating fluoroquinolone antibiotics contamination from water.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.CHEMOSPHERE.2019.125444
Abstract: While Co is the most effective metal for activating PMS, extensive efforts are made to develop Co/Fe species (CF) (e.g., CoFe
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.CHEMOSPHERE.2016.09.120
Abstract: Zero-valent iron (ZVI) was tested for the removal of 150 μg L
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.SCITOTENV.2017.09.015
Abstract: Remediation of CCA-contaminated soil (Cr, Cu, and As) by biodegradable chelant-enhanced washing (EDDS, S,S-ethylene-diamine-disuccinic-acid) needs further enhancement. This study investigated the effectiveness of coupling with pre-treatment by selective dissolution and post-treatment by soil amendments, respectively. Three groups of reagents (reductants, alkaline solvents, and organic ligands) were adopted in the pre-treatment to dissolve the oxide minerals before EDDS extraction. In the post-treatment, soil amendments (coal fly ash (CFA), acid mine drainage sludge (AMDS), green waste compost (GWC)), and their mixtures) were used for a 2-month stabilization after 2-h EDDS washing. Multi-endpoint evaluation was performed by assessing the chemical state, leachability, mobility, bioaccessibility, and plant-availability of residual metal(loid)s as well as the cytotoxicity, enzyme activities, and available nutrients of the treated soils. Pre-treatment by dithionite-citrate-bicarbonate significantly enhanced extraction efficiency, but also increased the leachability of As and Cr and bioaccessibility of Cr in the treated soils. While sodium hydroxide removed the majority of As without increasing its leachability and bioaccessibility, it increased the cytotoxicity and inhibited the acid phosphatase activity. Post-treatment with AMDS and CFA effectively controlled the mobility and leachability of residual As and Cr after EDDS washing. However, destabilized Cu was only marginally immobilized by GWC due to strong Cu-EDDS complexation. The bioaccessibility and phytoavailability of Cu was primarily reduced by EDDS washing, while those of As and Cr could be attenuated by AMDS and CFA. This study indicates that coupling chemical extraction with subsequent soil amendment plays complementary roles in mitigating effects of residual metal(loid)s and improving environmental quality.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 12-2021
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.BIORTECH.2017.08.170
Abstract: Valorisation of bread waste for hydroxymethylfurfural (HMF) synthesis was examined in dimethyl sulfoxide (DMSO)-, tetrahydrofuran (THF)-, acetonitrile (ACN)-, and acetone-water (1:1v/v), under heating at 140°C with SnCl
Publisher: American Chemical Society (ACS)
Date: 03-01-2022
Abstract: Electron transfer mediated by iron minerals is considered as a critical redox step for the dynamics of pollutants in soil. Herein, we explored the reduction process of Cr(VI) with different crystalline ferric oxyhydroxides in the presence of pyrogenic carbon (biochar). Both low- and high-crystallinity ferric oxyhydroxides induced Cr(VI) immobilization mainly
Publisher: Elsevier BV
Date: 02-2020
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.BIORTECH.2017.06.163
Abstract: This review addresses the use of biochar as a green and versatile catalyst support for emerging high-end applications beyond soil remediation, including chemical synthesis and biodiesel production from biomass, and pollutant degradation in the environment. Their catalytic performances are comparable or even superior to the conventional resin-, silica-, or carbon-based catalysts, owing to the favourable intrinsic features of biochar (various functional groups, intricate network of structures, etc.). Yet, distinctive active sites are needed for different applications. It is highlighted that the active site accessibility for substrates critically determines the performance, which is associated with the biochar physicochemical characteristics (-SO
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.JHAZMAT.2022.129691
Abstract: Biochar has been demonstrated as an efficient amendment for immobilizing contaminants. However, a certain number of micro/nano-scale particles are inevitably present in the fresh or aged biochar, which may facilitate the downward transport of contaminants along the soil profile, posing a detrimental impact on the groundwater. Herein, the effects of biochar colloids derived from wood chip and wheat straw at two temperatures (350 °C and 500 °C) on the transport and transformation of Cr(VI) in soil were investigated. All biochar colloids facilitated the transport of Cr(VI) in a loam clay Ultisol, which was attributed to the competition between biochar colloids and Cr(VI) for the available sorption sites on the soil surface. Wheat straw biochar colloids caused more transport of Cr(VI) than wood chip ones due to the more negative charge and higher polarity, which resulted in stronger electrostatic repulsion and competition with Cr(VI). It is soluble Cr(VI) that dominated the transport of Cr in the effluent solution, however, the particulate Cr(VI) could be reduced into Cr(III) before being carried by biochar colloids for co-transport. The 350 °C biochar colloids had higher electron donating capacities than 500 °C ones, resulting in more reduction of Cr(VI) and more co-transport as biochar colloids-associated Cr(III) in the effluent. Moreover, the more negatively charged 350 °C biochar colloids could also attach more soil Fe oxides, further facilitating the cotransport of Cr via the formation of a binary or ternary complex. Modeling showed the experimental-consistently results that biochar colloids caused 0.5-7.0 times faster transport of Cr(VI) than no biochar colloids in the long-term period. Our findings demonstrate that biochar colloids can enhance transport and transformation of Cr(VI) in soils, which arouse migration risk concern about in-situ remediation of Cr(VI)-contaminated soils by biochar.
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.03.057
Abstract: 243 surface soil s les were collected from the Yangtze River Delta (YRD) region, and the concentration distributions and compositional profiles of 27 parent PAHs (PPAHs), nitro- and oxy-derivatives (NPAHs and OPAHs), respectively, and health risk of 16 PPAHs were determined. Atmospheric s les were collected at two sites with high topsoil concentrations of PAHs to assist in identifying the emission sources of PPAHs. The total concentrations of PPAHs, NPAHs and OPAHs fell in the ranges of 21.0-3563.2 ng/g, 0.4-4.6 ng/g and 2.1-834.1 ng/g, respectively. PPAHs in topsoil were dominated by low and medium molecular weight species. The main components of OPAHs were 9FO and ANQ. For NPAHs, only 1N-NAP was frequently detected. Overall, the northern parts of the YRD region were more heavily contaminated by PPAHs and their corresponding derivatives. The soil TOC fraction and GDP per capita were significantly correlated with the spatial distribution of PPAHs. Specific ratios of isomeric species and principal component analysis (PCA) designated combustion of industrial coal and biomass, and traffic exhaust as the main mixed emission sources of PPAHs in surface soils in this region. The detected NPAHs and OPAHs were significantly associated with the corresponding PPAHs. The estimated incremental lifetime cancer risk attributed to 16 PPAHs in surface soil was greater than 10
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 04-2016
Publisher: Springer Science and Business Media LLC
Date: 27-05-2014
DOI: 10.1007/S11356-014-3032-3
Abstract: In situ metal stabilisation by amendments has been demonstrated as an appealing low-cost remediation strategy for contaminated soil. This study investigated the short-term leaching behaviour and long-term stability of As and Cu in soil amended with coal fly ash and/or green waste compost. Locally abundant inorganic (limestone and bentonite) and carbonaceous (lignite) resources were also studied for comparison. Column leaching experiments revealed that coal fly ash outperformed limestone and bentonite amendments for As stabilisation. It also maintained the As stability under continuous leaching of acidic solution, which was potentially attributed to high-affinity adsorption, co-precipitation, and pozzolanic reaction of coal fly ash. However, Cu leaching in the column experiments could not be mitigated by any of these inorganic amendments, suggesting the need for co-addition of carbonaceous materials that provides strong chelation with oxygen-containing functional groups for Cu stabilisation. Green waste compost suppressed the Cu leaching more effectively than lignite due to the difference in chemical composition and dissolved organic matter. After 9-month soil incubation, coal fly ash was able to minimise the concentrations of As and Cu in the soil solution without the addition of carbonaceous materials. Nevertheless, leachability tests suggested that the provision of green waste compost and lignite augmented the simultaneous reduction of As and Cu leachability in a fairly aggressive leaching environment. These results highlight the importance of assessing stability and remobilisation of sequestered metals under varying environmental conditions for ensuring a plausible and enduring soil stabilisation.
Publisher: Elsevier BV
Date: 05-2016
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JHAZMAT.2019.04.049
Abstract: CO
Publisher: Elsevier BV
Date: 05-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.02.005
Abstract: Multi-criteria analysis and detailed impact analysis were carried out to assess the sustainability of four remedial alternatives for metal-contaminated soil/sediment at former timber treatment sites and harbour sediment with different scales. The sustainability was evaluated in the aspects of human health and safety, environment, stakeholder concern, and land use, under four different scenarios with varying weighting factors. The Monte Carlo simulation was performed to reveal the likelihood of accomplishing sustainable remediation with different treatment options at different sites. The results showed that in-situ remedial technologies were more sustainable than ex-situ ones, where in-situ containment demonstrated both the most sustainable result and the highest probability to achieve sustainability amongst the four remedial alternatives in this study, reflecting the lesser extent of off-site and on-site impacts. Concerns associated with ex-situ options were adverse impacts tied to all four aspects and caused by excavation, extraction, and off-site disposal. The results of this study suggested the importance of considering the uncertainties resulting from the remedial options (i.e., stochastic analysis) in addition to the overall sustainability scores (i.e., deterministic analysis). The developed framework and model simulation could serve as an assessment for the sustainability likelihood of remedial options to ensure sustainable remediation of contaminated sites.
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.JHAZMAT.2019.120976
Abstract: Biofouling is the Achilles Heel of membrane processes. The accumulation of organic foulants and growth of microorganisms on the membrane surface reduce the permeability, shorten the membrane life, and increase the energy consumption. Advancements in novel carbon-based materials (CBMs) present significant opportunities in mitigating biofouling of membrane processes. This article provides a comprehensive review of the recent progress in the application of CBMs in antibiofouling membrane. It starts with a detailed summary of the different antibiofouling mechanisms of CBM-containing membrane systems. Next, developments in membrane modification using CBMs, especially carbon nanotubes and graphene family materials, are critically reviewed. Further, the antibiofouling potential of next-generation carbon-based membranes is surveyed. Finally, the current problems and future opportunities of applying CBMs for antibiofouling membranes are discussed.
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.CHEMOSPHERE.2016.09.110
Abstract: To enhance extraction of strongly bound metals from oxide minerals and organic matter, this study examined the sequential use of reductants, oxidants, alkaline solvents and organic acids followed by a biodegradable chelating agent (EDDS, [S,S]-ethylene-diamine-disuccinic-acid) in a two-stage soil washing. The soil was contaminated by Cu, Zn, and Pb at an e-waste recycling site in Qingyuan city, China. In addition to extraction efficiency, this study also examined the fate of residual metals (e.g., leachability, bioaccessibility, and distribution) and the soil quality parameters (i.e., cytotoxicity, enzyme activities, and available nutrients). The reductants (dithionite-citrate-bicarbonate and hydroxylamine hydrochloride) effectively extracted metals by mineral dissolution, but elevated the leachability and bioaccessibility of metals due to the transformation from Fe/Mn oxides to labile fractions. Subsequent EDDS washing was found necessary to mitigate the residual risks. In comparison, prior washing by oxidants (persulphate, hypochlorite, and hydrogen peroxide) was marginally useful because of limited amount of soil organic matter. Prior washing by alkaline solvents (sodium hydroxide and sodium bicarbonate) was also ineffective due to metal precipitation. In contrast, prior washing by low-molecular-weight organic acids (citrate and oxalate) improved the extraction efficiency. Compared to hydroxylamine hydrochloride, citrate and oxalate induced lower cytotoxicity (Microtox) and allowed higher enzyme activities (dehydrogenase, acid phosphatase, and urease) and soil nutrients (available nitrogen and phosphorus), which would facilitate reuse of the treated soil. Therefore, while sequential washing proved to enhance extraction efficacy, the selection of chemical agents besides EDDS should also include the consideration of effects on metal leachability/bioaccessibility and soil quality.
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.ENVPOL.2017.07.035
Abstract: Alkylated PAHs (APAHs) have been shown to be more toxic and persistent than their non-alkylated parent compounds. However, little is known about the extent of soil contamination by these pollutants. To help understand agricultural soil pollution by these compounds at a regional scale, a total of 18 methylated PAHs (MPAHs, a major class of APAHs) in 243 soil s les were analyzed. These soil s les were collected from 11 sites in the Yangtze River Delta (YRD) region, a representative fast developing area in China. The total concentration of MPAHs (∑18MPAHs) ranged from 5.5 to 696.2 ng/g dry soil, with methylnaphthalenes (M-NAPs) and methylphenanthrenes (M-PHEs) accounting for more than 70% of the compositional profile. Relatively high concentrations of ∑18MPAHs were found in Jiaxing and Huzhou areas of Zhejiang province, as well as on the border between the cities of Wuxi and Suzhou. Different MPAH groups showed dissimilar spatial distribution patterns. The spatial distribution of lower molecular weight MPAHs was related to agricultural straw burning and emissions/depositions from industrial activities, whereas that of higher molecular weight MPAHs was much more a function of the total organic carbon (TOC) content of soil. Although coal, biomass (crop straw and wood), and petroleum combustion were identified to be the major emission sources for most of the s ling sites, the areas with relatively severe pollution with ∑18MPAHs resulted from the localized hotspots of petroleum leakage. Isomeric MPAHs with methyl group substituted at 2- (β) position exhibited significantly higher concentrations than those substituted at 1- (α) position. Results of this work help to understand soil pollution by MPAHs, and are useful for designing effective strategies for pollution control so as to ensure food safety in areas with fast economic growth.
Publisher: Mary Ann Liebert Inc
Date: 10-2013
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.ENVPOL.2018.08.012
Abstract: Biochar has been used for immobilizing heavy metals in soils due to its abundant surface functional groups and mineral components. However, as carbonaceous material, biochar in soils is susceptible to natural aging, which could alter its structural properties and ability to retain heavy metals. In this study, the impacts of pre- and post-application aging on the properties of dairy manure and sawdust biochars and the significance of different mechanisms of complexation with surface functional groups and mineral precipitation for Cd immobilization in soils were investigated. The simulated natural aging including 25 dry-wet cycles and 25 freeze-thaw cycles decreased the pH of biochar from 8.2 to 10.7 to 7.5-9.7 while increased the release of dissolved organic carbon from 4.1 to 10.9 to 5.9-21.3 mg L
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.CHEMOSPHERE.2019.05.238
Abstract: Based on the "waste-treat-waste" concept, biochars were produced from cadmium (Cd)-contaminated rice straw (CRSBs) at 300, 500, and 700 °C (CRSB300, CRSB500, and CRSB700). The risks of the Cd remaining in CRSBs were evaluated and the optimal biochar pyrolysis temperature for Cd removal was investigated. It was observed that 41% of the total Cd in the raw rice straw was exchangeable, which may pose significant risks to crops and humans. Pyrolyzing at 300 °C did not significantly alter the Cd fractions, while the exchangeable fraction of Cd greatly dropped to 5.79% at 500 °C and further to 2.12% at 700 °C. Increasing the highest pyrolysis temperature resulted in CRSBs with higher pH values, greater surface area, and smaller pore sizes, thus providing more rapid and efficient removal of Cd from aqueous solutions. For Cd removal tests, increasing pyrolysis temperature (300-700 °C) increased the total (24.8-55.1 mg/g) and non-exchangeable (18.9-52.8 mg/g) Cd concentrations immobilized on the CRSBs and significantly decreased the exchangeable Cd fraction (23.7%-4.85%). It is suggested based on the study from aqueous solutions that CRSB700 was the most suitable for the remediation of Cd contaminated soil on site due to the lowest risks of remained Cd from feedstock, fastest and highest Cd removal, and most stable immobilization of Cd.
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.CHEMOSPHERE.2018.07.088
Abstract: A two stage multi-fraction 1
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 11-2017
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.ENVINT.2019.105406
Abstract: Arsenic-alkali residue (AAR) from antimony smelting is highly hazardous due to its ready leachability of As, seeking for proper disposal such as stabilization treatment. However, As stabilization in AAR would be challenging due to the high content of coexisting soluble carbonate. This study conducted the stabilization treatments of AAR by ferrous sulfate and lime, respectively, and revealed the significant influence of coexisting carbonate. It was found that ferrous sulfate was more efficient than lime, which required only one-tenth of dosages of lime to reduce the As leaching concentration from 915 mg/L to a level below 2.5 mg/L to meet the Chinese regulatory limit. The combining qualitative and quantitative analyses based on XRD, SEM-EDS, and thermodynamic modeling suggested that the formation of insoluble arsenate minerals, ferrous arsenate or calcium arsenate, was the predominant mechanism for As stabilization in the two treatment systems, and their efficiency difference was primarily attributed to the coexisting carbonate, which had a slight effect on ferrous arsenate but severely obstructed calcium arsenate formation. Moreover, the examination of As leaching concentrations in 1-year-cured s les indicated that the long-term stability of ferrous sulfate treatment was far superior to that of lime treatment. This study provides ferrous salts as a promising and green scheme for stabilization treatment of AAR as well as other similar As-bearing solid wastes with coexisting soluble carbonate.
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.BIORTECH.2019.122544
Abstract: Lignocellulosic wastes constitute a significant portion of the municipal solid waste, which should be valorised for the synthesis of value-added chemicals to achieve circular bioeconomy. This study evaluates the use of γ-valerolactone (GVL) and acetone as green co-solvents to produce levulinic acid (LA) from lignocellulosic paper towel waste at different temperatures using dilute H
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JHAZMAT.2019.04.071
Abstract: This study fabricated a new and multifunctional mixed metal-biochar composites (MMBC) using the mixture of two abundant industrial wastes, red mud (RM) and lignin, via pyrolysis under N
Publisher: American Chemical Society (ACS)
Date: 31-07-2020
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 09-2020
Publisher: Springer Science and Business Media LLC
Date: 15-05-2007
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 2018
Publisher: Frontiers Media SA
Date: 14-11-2018
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.CHEMOSPHERE.2019.125664
Abstract: Most of the volatile organic compounds (VOCs) are toxic and harmful to human health and environment. In this study, hydrochars activated with CO
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.BIORTECH.2017.08.196
Abstract: Hydrothermal liquefaction has been widely applied to obtain bioenergy and high-value chemicals from biomass in the presence of a solvent at moderate to high temperature (200-550°C) and pressure (5-25MPa). This article summarizes and discusses the conversion of agricultural and forestry wastes by hydrothermal liquefaction. The history and development of hydrothermal liquefaction technology for lignocellulosic biomass are briefly introduced. The research status in hydrothermal liquefaction of agricultural and forestry wastes is critically reviewed, particularly for the effects of liquefaction conditions on bio-oil yield and the decomposition mechanisms of main components in biomass. The limitations of hydrothermal liquefaction of agricultural and forestry wastes are discussed, and future research priorities are proposed.
Publisher: Elsevier BV
Date: 02-2015
DOI: 10.1016/J.JHAZMAT.2014.09.056
Abstract: Conventional marine disposal of contaminated sediment presents significant financial and environmental burden. This study aimed to recycle the contaminated sediment by assessing the roles and integration of binder formulation, sediment pretreatment, curing method, and waste inclusion in stabilization/solidification. The results demonstrated that the 28-d compressive strength of sediment blocks produced with coal fly ash and lime partially replacing cement at a binder-to-sediment ratio of 3:7 could be used as fill materials for construction. The X-ray diffraction analysis revealed that hydration products (calcium hydroxide) were difficult to form at high sediment content. Thermal pretreatment of sediment removed 90% of indigenous organic matter, significantly increased the compressive strength, and enabled reuse as non-load-bearing masonry units. Besides, 2-h CO2 curing accelerated early-stage carbonation inside the porous structure, sequestered 5.6% of CO2 (by weight) in the sediment blocks, and acquired strength comparable to 7-d curing. Thermogravimetric analysis indicated substantial weight loss corresponding to decomposition of poorly and well crystalline calcium carbonate. Moreover, partial replacement of contaminated sediment by various granular waste materials notably augmented the strength of sediment blocks. The metal leachability of sediment blocks was minimal and acceptable for reuse. These results suggest that contaminated sediment should be viewed as useful resources.
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.JENVMAN.2018.11.091
Abstract: In order to reduce landfill disposal of waterworks sludge (alum sludge) and incinerated sewage sludge ash (ISSA), this study proposed an innovative approach for upcycling them into value-added controlled low-strength materials (CLSM). Waterworks sludge interfered with cement hydration reaction and delayed the stiffening time of CLSM (>10 h) due to its high organics content (5%). The addition of triethanolamine (TEA) with a dosage of 0.1 wt% of binder effectively shortened the stiffening time to 4.5 h. The lab-scale results suggested that the optimal CLSM design (6% cement, 14% ISSA, 8% sludge, and 72% recycled fine aggregate at a water/binder ratio of 1.2) complied with the standard requirement of flowability (>200 mm), stiffening time (<5 h), and compressive strength (0.3-2.1 MPa). The pilot-scale field tests further confirmed that the sludge-incorporated CLSM achieved a high flowability (220 mm), short stiffening time (4 h), low compressive strength (1.38 MPa), and easy re-excavatability after 3 months. This study demonstrated that waterworks sludge can be potentially transformed into sustainable construction materials for urban development.
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.02.119
Abstract: Nanoscale zero-valent iron (nZVI) was tested for the removal of Cu(II), Zn(II), Cr(VI), and As(V) in model saline wastewaters from hydraulic fracturing. Increasing ionic strength (I) from 0.35 to 4.10 M (Day-1 to Day-90 wastewaters) increased Cu(II) removal (25.4-80.0%), inhibited Zn(II) removal (58.7-42.9%), slightly increased and then reduced Cr(VI) removal (65.7-44.1%), and almost unaffected As(V) removal (66.7-75.1%) by 8-h reaction with nZVI at 1-2 g L
Publisher: Springer Science and Business Media LLC
Date: 11-10-2022
DOI: 10.1007/S42773-022-00182-X
Abstract: Biochar is a waste-derived material that can sequester carbon at a large scale. The development of low-carbon and sustainable biochar-enhanced construction materials has attracted extensive interest. Biochar, having a porous nature and highly functionalised surface, can provide nucleation sites for chemical reactions and exhibit compatibility with cement, asphalt, and polymer materials. This study critically reviewed the state-of-the-art biochar-enhanced construction materials, including biochar-cement composites, biochar-asphalt composites, biochar-plastic composites, etc. The efficacies and mechanisms of biochar as construction materials were articulated to improve their functional properties. This critical review highlighted the roles of biochar in cement hydration, surface functional groups of engineered biochar for promoting chemical reactions, and value-added merits of biochar-enhanced construction materials (such as humidity regulation, thermal insulation, noise reduction, air/water purification, electromagnetic shielding, and self-sensing). The major properties of biochar are correlated to the features and functionalities of biochar-enhanced construction materials. Further advances in our understanding of biochar’s roles in various composites can foster the next-generation design of carbon–neutral construction materials. Graphical Abstract
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.ENVINT.2019.01.047
Abstract: This paper evaluates a novel sorbent for the removal of potentially toxic elements, inherent cations, and hetero-chloride from hydraulic fracturing wastewater (FWW). A series of iron-biochar (Fe-BC) composites with different Fe/BC impregnation mass ratios (0.5:1, 1:1, and 2:1) were prepared by mixing forestry wood waste-derived BC powder with an aqueous FeCl
Publisher: Elsevier BV
Date: 04-2022
DOI: 10.1016/J.JHAZMAT.2022.128223
Abstract: Heteroatom doping is a promising technique to enhance biochar for effective environmental remediation. However, development of electroactive heteroatom-doped biochars, e.g., sulfur-doped biochar, has been hindered due to complex nature of non-stoichiometric biomass-derived carbon and changeable electrochemical state of dopants. Herein, we produced a series of wood waste-derived biochars with customized levels of minerals and redox-active moieties, aiming to unravel the crucial factors for sulfur doping. Calcium (Ca) in biochar was found to preferentially coordinate with sulfur to form inactive inorganic sulfur minerals (i.e., CaSO
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.SCITOTENV.2017.09.271
Abstract: Soil pollution is a global problem in both developed and developing countries. Countries with rapidly developing economies such as China are faced with significant soil pollution problems due to accelerated industrialization and urbanization over the last decades. This paper provides an overview of published scientific data on soil pollution across China with particular focus on organic contamination in agricultural soils. Based on the related peer-reviewed papers published since 2000 (n=203), we evaluated the priority organic contaminants across China, revealed their spatial and temporal distributions at the national scale, identified their possible sources and fates in soil, assessed their potential environmental risks, and presented the challenges in current remediation technologies regarding the combined organic pollution of agricultural soils. The primary pollutants in Northeast China were polycyclic aromatic hydrocarbons (PAHs) due to intensive fossil fuel combustion. The concentrations of organochlorine pesticides (OCPs) and phthalic acid esters (PAEs) were higher in North and Central China owing to concentrated agricultural activities. The levels of polychlorinated biphenyls (PCBs) were higher in East and South China primarily because of past industrial operations and improper electronic waste processing. The co-existence of organic contaminants was severe in the Yangtze River Delta, Pearl River Delta, and Beijing-Tianjin-Hebei Region, which are the most populated and industrialized regions in China. Integrated biological-chemical remediation technologies, such as surfactant-enhanced bioremediation, have potential uses in the remediation of soil contaminated by multiple contaminants. This critical review highlighted several future research directions including combined pollution, interfacial interactions, food safety, bioavailability, ecological effects, and integrated remediation methods for combined organic pollution in soil.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.SCITOTENV.2017.11.159
Abstract: Polybrominated diphenyl ethers (PBDEs) are common pollutants released from electronic waste (e-waste) dismantling and recycling activities. Our city-wide survey of agricultural soils in Qingyuan (40 s ling sites), where e-waste recycling has been active, observed exceedance of PBDEs above background levels (average of 251.9ngg
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.JHAZMAT.2019.02.110
Abstract: Rapidly increasing development of nuclear power stimulates the exploration of low-cost and highly efficient materials to selectively remove uranium (VI) from contaminated wastewater streams. Herein, we successfully developed a novel hydroxyapatite (HAP) adsorbent by using a facile and template-free hydrothermal method. The XRD results demonstrated that the HAP was crystallized in hexagonal structure (space group P63/m(176)), and the images of SEM and TEM indicated that the HAP possessed hollow and hierarchical nanostructure. A large BET specific surface area (182.6 m
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.BIORTECH.2018.10.042
Abstract: A novel method incorporating electrochemical (EC) modification and one-step pyrolysis is developed to prepare sustainable Fe
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.SCITOTENV.2018.01.002
Abstract: In recent years, biochar has been extensively studied as a sorbent for immobilizing contaminants and minimizing their bioavailability in soils. Few studies have been conducted to evaluate the interactions between biochar and compost in soils and their impact on degradation of organic contaminants. In the present study, soils with high organic carbon content (HOC) and low organic carbon content (LOC) were spiked with 100mg·kg
Publisher: Elsevier BV
Date: 05-2022
DOI: 10.1016/J.JHAZMAT.2022.128479
Abstract: Electroactive Fe-biochar has attracted significant attention for As(III)/Cr(VI) immobilization through redox reactions, and its performance essentially lies in the regulation of various Fe/C moieties for desired redox performance. Here, a series of Fe-biochar with distinct Fe/C speciation were rationally produced via two-step pyrolysis of iron minerals and biomass waste at 400-850 °C (BCX-Fe-Y, X and Y represented the first- and second-step pyrolysis temperature, respectively). The redox transformation of Cr(VI) and As(III) by Fe-biochar was evaluated in simulated wastewater under oxic or anoxic conditions. Results showed that more effective Cr(VI) reduction could be achieved by BCX-Fe-400, while a higher amount of As (III) was oxidized by BCX-Fe-850 under the anoxic environment. Besides, BCX-Fe-400 could generate more reactive oxygen species (e.g.,
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2GC02568J
Abstract: Gluconic acid and glucuronic acid are produced from biomass-derived glucose over low-cost biochar-supported Cu catalysts in a microwave-enhanced base-free system.
Publisher: American Chemical Society (ACS)
Date: 11-12-2018
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 02-2023
DOI: 10.1016/J.JHAZMAT.2022.130308
Abstract: Rice grown in soils contaminated with arsenic (As) and lead (Pb) can cause lower rice yield and quality due to the toxic stress. Herein, we examined the role of functionalized biochars (raw phosphorus (P)-rich (PBC) and iron (Fe)-modified P-rich (FePBC)) coupled with different irrigation regimes (continuously flooded (CF) and intermittently flooded (IF)) in affecting rice yield and accumulation of As and Pb in rice grain. Results showed that FePBC increased the rice yield under both CF (47.4%) and IF (19.6%) conditions, compared to the controls. Grain As concentration was higher under CF (1.94-2.42 mg kg
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.03.022
Abstract: Biochar has been adopted to control the mobility and phytoavailability of trace elements (TEs) in soils. To date, no attempt has been made to determine the mobility and phytoavailability of arsenic (As) and lead (Pb) in a contaminated soil with biochars as amendments under predefined redox potentials (E
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 12-2023
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.SCITOTENV.2017.12.195
Abstract: Biochar is an emerging low-cost sorbent used for removing trace metals from water. In this study, we evaluated the removal potential of aqueous hexavalent chromium (Cr(VI)) by biochars produced from soybean (Glycinemax L.) and burcucumber (Sicyos angulatus L.) residues. The highest Cr(VI) removal from solution occurred at low pH values (pH2-5), and adsorption decreased approximately tenfold when the pH increased from 2 to 10. Synchrotron-based X-ray absorption spectroscopy (XAS) investigations showed that Cr(VI) species were reduced to trivalent chromium (Cr(III)) at the biochar surface following Cr(VI) adsorption. Linear combination fitting (LCF) of X-ray absorption near edge structure (XANES) data indicated that approximately 90% of the total Cr(VI) (962μM) was reduced to Cr(III). Extended X-ray absorption fine structure (EXAFS) fitting results yielded interatomic chromium (CrCr) distances consistent with the formation of Cr(III) precipitates as Cr(OH)
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.SCITOTENV.2017.12.194
Abstract: To date, no investigation has been carried out to explore the effects of biochars produced at different pyrolysis temperatures on the dynamics of redox potential (E
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.ENVINT.2019.04.006
Abstract: Iron nanoparticles encapsulated within boron and nitrogen co-doped carbon nanoshell (B/N-C@Fe) were synthesized through a novel and green pyrolysis process using melamine, boric acid, and ferric nitrate as the precursors. The surface morphology, structure, and composition of the B/N-C@Fe materials were thoroughly investigated. The materials were employed as novel catalysts for the activation of potassium monopersulfate triple salt (PMS) for the degradation of levofloxacin (LFX). Linear sweep voltammograms and quenching experiments were used to identify the mechanisms of PMS activation and LFX oxidation by B/N-C@Fe, where SO
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/S1001-0742(12)60296-4
Abstract: Natural and anthropogenic arsenic (As) contamination of water sources pose serious health concerns, especially for small communities in rural areas. This study assessed the applicability of three industrial byproducts (coal fly ash, lignite, and green waste compost) as the low-cost adsorbents for As(V) removal under various field-relevant conditions (dissolved oxygen, As(V)/Fe ratio, solution pH, and presence of competing species). The physico-chemical properties of the adsorbents were characterized by XRD, XRF, FT-IR, and NMR analysis. Batch experiments demonstrated that coal fly ash could provide effective As(V) removal (82.1%-95%) because it contained high content of amorphous iron/aluminium hydroxides for As(V) adsorption and dissolvable calcium minerals for calcium arsenate precipitation. However, the addition of lignite and green waste compost was found unfavourable since they hindered the As(V) removal by 10%-42% possibly due to dissolution of organic matter and ternary arsenate-iron-organic matter complexes. On the other hand, higher concentrations of dissolved iron (comparing As(V)/Fe ratios of 1:1 and 1:10) and dissolved oxygen (comparing 0.2 and 6 mg/L) only marginally enhanced the As(V) removal at pH 6 and 8. Thus, addition of dissolved iron, water aeration, or pH adjustment became unnecessary because coal fly ash was able to provide effective As(V) removal under the natural range of geochemical conditions. Moreover, the presence of low levels of background competing (0.8 or 8 mg/L of humic acid, phosphate, and silicate) imposed little influence on As(V) removal, possibly because the high adsorption capacity of coal fly ash was far from exhaustion. These results suggested that coal fly ash was a potentially promising adsorbent that warranted further investigation.
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.ENVINT.2019.01.024
Abstract: Potentially toxic elements such as heavy metals are ubiquitous in the environment. Risk-based environmental management relies upon identifying pollution sources, pathways, and the exposed population. In a Chinese urban setting, many residents live in high-rise buildings without private gardens. Therefore, the main residential risk of exposure to contaminated soils and dusts may be associated with public open spaces. As children are the most vulnerable receptor, playgrounds represent an important yet often overlooked exposure point. The present study assessed plausible sources of heavy metals at children's playgrounds in a representative metropolitan environment. Soil and equipment dust s les were collected from 71 playgrounds across Beijing, which were analyzed for 11 different heavy metals. Principal component analysis (PCA) was used to identify the latent constructs which control heavy metal variability and reflect potential sources. Cluster analysis (CA) was conducted to group s led locations, which provided further insights on plausible sources. The main factors extracted from the PCA were then subject to geostatistical analysis. The systematic combination of GIS with multivariate statistical analysis proved valuable for elucidating anthropogenic and natural sources. Elevated Be, V, Cr, Mn, Co, Ni, As in playground soils were found to derive mainly from the natural background (spatial autocorrelation = 2 km), while elevated Cu and Pb was attributed to traffic activities (spatial autocorrelation = 17 km), especially along the routes of Beijing's inner ring-roads, the major roads toward the northwest and northeast, and the international airport. These results suggest that heavy metals in playground equipment dust may derive mainly from atmospheric deposition of air pollution of both natural and anthropogenic origin (spatial autocorrelation = 11-13 km). Among them, Be, V, Mn, Co, Cu, As, Pb were attributed to atmospheric pollution deriving from the north of Beijing, brought by the prevailing northern wind in the winter season whereas, Cr and Ni may possibly be brought from the southeast by the summer season winds. Knowledge of anthropogenic vs. natural origins of heavy metals in playgrounds is critical in assessing health impact and designing policy instruments for metropolitan areas.
Publisher: American Chemical Society (ACS)
Date: 29-04-2021
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.SCITOTENV.2017.09.332
Abstract: In this study, alginate and polyvinyl alcohol (PVA)-alginate entrapped nanoscale zero-valent iron (nZVI) was tested for structural evolution, chemical transformation, and metals/metalloids removal (Cu(II), Cr(VI), Zn(II), and As(V)) after 1-2month passivation in model saline wastewaters from hydraulic fracturing. X-ray diffraction analysis confirmed successful prevention of Fe
Publisher: Wiley
Date: 05-01-2023
Abstract: Copper/carbon catalysts under different electron‐transfer regimes can evolve both radical and nonradical pathways in peroxide activation. However, the underlying trigger to manipulate the transition in between is unclear. Herein, it is revealed that Cu species in a state of sub‐nanometre particles (SNPs, 1 nm) exhibits an electrophilic nature, which is opposite to its nucleophilic nature at a larger scale (nanoclusters, 1 nm). This switch between nucleophile/electrophile nature leads to distinct catalytic mechanisms in activating peroxymonosulfate, i.e., nonradical 1 O 2 surface‐bound upon Cu SNPs and unleashed radical • OH induced by Cu nanoclusters. The vacancy defects of biomass‐derived carbon can stabilize Cu SNPs via a CuVC configuration, circumventing the contemporary difficulties in coordinating reserving MetalNC bonding. Depth profiling, chemical probes, and charge density difference modeling support the regulable electroactive nature over modulated Cu scales. This featured system is applied for tetracycline degradation, and Cu SNPs demonstrates the highest efficacy with their better peroxymonosulfate confinement in nonradical regime (88.9% removal, nucleophilic activation). Comparatively, severe Cu leaching caused by radical erosion (44.8% removal, electron‐donation) is undesirable. Overall, a regulable heterogeneous catalysis is unraveled over carbon‐supported Cu sites through scaling modulation and defect engineering. This study illuminates a promising path for customizing biomass‐derived Cu‐based catalysts to achieve versatile catalysis.
Publisher: American Chemical Society (ACS)
Date: 10-05-2021
Publisher: Elsevier BV
Date: 05-2023
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JENVMAN.2019.02.044
Abstract: Biochar application has multiple benefits for soil fertility improvement and climate change mitigation. Biochar can act as a source of nutrients and sequester carbon (C) in the soil. The nutrient release capacity of biochar once applied to the soil varies with the composition of the biochar, which is a function of the feedstock type and pyrolysis condition used for biochar production. Biochar has a crucial influence on soil C mineralization, including its positive or negative priming of microorganisms involved in soil C cycling. However, in various cases, biochar application to the soil may cause negative effects in the soil and the wider environment. For instance, biochar may suppress soil nutrient availability and crop productivity due to the reduction in plant nutrient uptake or reduction in soil C mineralization. Biochar application may also negatively affect environmental quality and human health because of harmful compounds such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins, and dibenzofurans (PCDD/DF). In this review, we discuss the linkage between biochar composition and function, evaluate the role biochar plays in soil fertility improvement and C sequestration, and discuss regulations and concerns regarding biochar's negative environmental impact. We also summarize advancements in biochar production technologies and discuss future challenges and priorities in biochar research.
Publisher: Elsevier BV
Date: 09-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0GC01761B
Abstract: NaCl promotes starch gelatinisation via selective interactions with –OH groups and assists auto-catalysed hydrolysis, reducing energy use by 70% in microwave compared to conventional heating.
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 10-2018
Publisher: Informa UK Limited
Date: 16-09-2016
Publisher: Elsevier BV
Date: 11-2017
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.BIORTECH.2017.01.017
Abstract: This study aimed to maximize the valorization of bread waste, a typical food waste stream, into hydroxymethylfurfural (HMF) by improving our kinetic understanding. The highest HMF yield (30mol%) was achieved using SnCl
Publisher: Elsevier BV
Date: 12-2019
Publisher: American Chemical Society (ACS)
Date: 23-10-2018
Publisher: Wiley
Date: 07-2015
Abstract: Recycling sewage sludge by pyrolysis has attracted increasing attention for pollutant removal from wastewater and soils. This study scrutinized As(III) sorption behavior on sludge-derived biochar (SDBC) under different pyrolysis conditions and solution chemistry. The SDBC pyrolyzed at a higher temperature showed a lower As(III) sorption capacity and increasingly nonlinear isotherm due to loss of surface sites and deoxygenation-dehydrogenation. The Langmuir sorption capacity on SDBC (3.08-6.04 mg g) was comparable to other waste-derived sorbents, with the highest As(III) sorption on SDBC pyrolyzed at 400°C for 2 h. The As(III) sorption kinetics best fit with the pseudo-second-order equation, thus suggesting the significance of the availability of surface sites and initial concentration. Sorption of As(III) was faster than that of Cr(VI) but slower than that of Pb(II), which was attributed to their differences in molar volume (correlated to diffusion coefficients) and sorption mechanisms. The X-ray photoelectron spectra revealed an increase of oxide oxygen (O) with a decrease of sorbed water, indicative of ligand exchange with hydroxyl groups on SDBC surfaces. The As(III) sorption was not pH dependent in acidic-neutral range (pH 8) because of As(III) speciation in solution. An increasing ionic strength (0.001-0.1 mol L) facilitated As(III) sorption, indicating the predominance of ligand exchange over electrostatic interactions, while high concentrations (0.1 mol L) of competing anions (fluoride, sulfate, carbonate, and phosphate) inhibited As(III) sorption. These results suggest that SDBC is applicable for As(III) immobilization in most environmentally relevant conditions.
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.JHAZMAT.2021.127060
Abstract: The science-informed design of 'green' carbonaceous materials (e.g., biochar and activated carbon) with high removal capacity of recalcitrant organic contaminants (e.g., pharmaceuticals and personal care products (PPCPs)) is indispensable for promoting sustainable wastewater treatment. In this study, machine learning (ML) incorporating PPCPs and biochar properties as well as adsorption conditions were applied to build adsorption prediction models and explore the contributions of various biochar's inherent properties to their PPCPs adsorption capacity. The results demonstrated that the models developed by detailed biochar properties (e.g., surface functionality and hierarchical porous structure) from advanced microscopic and spectroscopic techniques were more accurate (i.e., the root-mean-square error decreased by 18-24%) than those by general information such as bulk elemental composition and total pore volume. The relative importance of surface carbon functionalities ranked in the order of C-O bond > CO bond > non-polar carbon for predicting the adsorption capacity. According to the partial dependence analysis, the average pore diameters of adsorbents that were larger than the maximum diameter of PPCPs molecules by 1.5-fold to 2.5-fold favored the PPCPs adsorption. This study reveals new insights into the adsorption of PPCPs and provides a comprehensive reference for the sustainable engineering of biochar adsorbents for PPCPs wastewater treatment.
Publisher: American Chemical Society (ACS)
Date: 26-09-2019
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.SCITOTENV.2017.09.201
Abstract: To develop the environmentally benign thermo-chemical process, this study placed great emphasis on the influence of CO
Publisher: Springer Science and Business Media LLC
Date: 09-10-2022
DOI: 10.1007/S42773-022-00185-8
Abstract: Biochar from bio-waste pyrolysis presents excellent CO 2 sequestration capacity. This study innovated the design of cement-bonded particleboards utilizing a substantial amount of 50–70 wt.% pre-soaked biochar to render the products carbon-negative. We investigated the roles of biochar in magnesium oxysulfate cement (MOSC) system and demonstrated good mechanical and functional properties of biochar cement particleboards. In the presence of biochar, the amounts of hydration products were enriched in the cement systems as illustrated by the thermogravimetric analyses (TGA) and X-ray diffraction (XRD). We further incorporated supplementary cementitious materials (SCMs) and generated 5 Mg(OH) 2 ⋅MgSO 4 ·7H 2 O (5–1–7) phase in the MOSC system. As a result, our designs of biochar particleboards satisfied the standard requirements for flexural strength ( 5.5 MPa) and thickness swelling ( 2%). Moreover, our biochar particleboards presented a low thermal conductivity as the biochar pores disrupted thermal bridging within particleboards. We illustrated that the high dosage ratio of biochar could significantly offset the CO 2 emissions of the particleboards (i.e., carbon-negative) via life cycle assessment. Noticeable economic profits could also be accomplished for the biochar particleboards. For instance, the 50BC-MOSC bonded particleboard (with 50 wt.% pre-soaked biochar as aggregate, 50 wt.% MOSC as binder) with promising mechanical properties could store 137 kg CO 2 tonne −1 and yield an overall economic profit of 92 to 116 USD m −3 depending on the carbon prices in different countries. In summary, our new designs of carbon-negative biochar particleboards could curtail carbon emissions in the construction materials and promote the realization of carbon neutrality and circular economy. Graphical Abstract
Publisher: Elsevier BV
Date: 2017
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.ENVINT.2019.02.057
Abstract: Stabilization/solidification (S/S) is a low-cost and high-efficiency remediation method for contaminated soils, however, conventional cement-based S/S method has environmental constraints and sustainability concerns. This study proposes a low-carbon, cement-free, clay-based approach for simultaneous S/S of As and Pb in the contaminated soil, and accordingly elucidates the chemical interactions between alkali-activated clay binders and potentially toxic elements. Quantitative X-ray diffraction and
Publisher: American Chemical Society (ACS)
Date: 03-11-2022
Publisher: Informa UK Limited
Date: 11-2013
Publisher: Elsevier BV
Date: 08-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0SC01397H
Abstract: The isocyanate groups (–NCO) derived from –NC– bonds in the organic ligands enables the thermally treated ZIF-8 to act as wide-spectrum photocatalyst.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9GC03553B
Abstract: Valorization of lignin to valuable chemicals and biofuels increases the economic viability of sustainable biorefineries.
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JHAZMAT.2019.121138
Abstract: The oxidation of trivalent arsenic (As(III)) to pentavalent arsenic (As(V)) is a common pretreatment to remove As(III) from the aqueous phase. The graphitic carbon nitride as a photocatalyst can transform As(III) to As(V), but the photocatalyst does not adsorb any species of arsenic. In this study, a new composite material to achieve the simultaneous oxidation and adsorption of arsenic was synthesized by co-pyrolyzing alum sludge and melamine. It was hypothesized that graphitic carbon nitride derived from melamine oxidizes As(III) to As(V) and pyrolyzed alum sludge provides strong adsorption sites for the oxidized As(V). The composites were characterized by X-ray diffraction, Brunauer-Emmett-Teller(BET) surface, scanning electron microscope, and X-ray photoelectron spectrometer. The composite material effectively converted As(III) to As(V) under the light, and the total arsenic concentration decreased in the aqueous phase via the adsorption of As(V). Speciation analysis of arsenic on the composite showed that both As(III) and As(V) species were present on the surface of adsorbent, from which desorption by mixing with deionized water was difficult. This new and green composite material can oxidize As(III) and adsorb arsenic simultaneously under the light, which can be used to treat arsenic-containing water.
Publisher: Informa UK Limited
Date: 16-06-2015
DOI: 10.1080/09593330.2015.1054316
Abstract: Ciprofloxacin (CIP) is a commonly used antibiotic and widely detected in wastewaters and farmlands nowadays. This study evaluated the efficacy of next-generation adsorbent (graphene) and conventional adsorbent (granular activated carbon, GAC) for CIP removal. Batch experiments and characterization tests were conducted to investigate the adsorption kinetics, equilibrium isotherms, thermodynamic properties, and the influences of solution chemistry (pH, ionic strength, natural organic matter (NOM), and water sources). Compared to GAC, graphene showed significantly faster adsorption and reached equilibrium within 3 min, confirming the rapid access of CIP into the macroporous network of high surface area of graphene as revealed by the Brunner-Emmet-Teller measurements analysis. The kinetics was better described by a pseudo-second-order model, suggesting the importance of the initial CIP concentration related to surface site availability of graphene. The adsorption isotherm on graphene followed Langmuir model with a maximum adsorption capacity of 323 mg/g, which was higher than other reported carbonaceous adsorbents. The CIP adsorption was thermodynamically favourable on graphene and primarily occurred through π - π interaction, according to the FTIR spectroscopy. While the adsorption capacity of graphene decreased with increasing solution pH due to the speciation change of CIP, the adverse effects of ionic strength (0.01-0.5 mol L(-1)), presence of NOM (5 mg L⁻¹), and different water sources (river water or drinking water) were less significant on graphene than GAC. These results indicated that graphene can serve as an alternative adsorbent for CIP removal in commonly encountered field conditions, if proper separation and recovery is available in place.
Publisher: Elsevier BV
Date: 10-2017
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.SCITOTENV.2019.135725
Abstract: This study reports the preparation of nanobiochar (NBC) via top-down approach of bioenergy waste-derived dendro biochar through mechanised grinding in order to assess its capacity to remove emerging contaminants, such as antibiotics, agrochemicals, and potentially toxic elements from aqueous media. Preconditioned biochar was disc milled in ethanol media, and the resulting colloidal biochar was dispersed in water to obtain the NBC fraction by centrifugation. Adsorption edge and isotherm experiments were carried out at pH 3 to 8 and NBC dosages of 0.5 g/L for oxytetracycline (OTC), glyphosate (GL), hexavalent chromium (CrVI), and cadmium (CdII). NBC was characterised by scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area, and Fourier transform infrared spectroscopy, which demonstrated the flakey and graphitic nature of the NBC particles with a surface area of 28 m
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.ENVINT.2019.02.061
Abstract: Little is known about the effects of applying amendments on soil for immobilizing metal(loid)s on the soil microbial community. Alterations in the microbial community were examined after incubation of treated contaminated soils. One soil was contaminated with Pb and As, a second soil with Cd and Zn. Red pepper stalk (RPS) and biochars produced from RPS in either N
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.JENVMAN.2019.01.018
Abstract: Valorization of corn waste involves synthesis of hydrochar for use as a sorbent for ammonium nitrogen recovery from swine manure compost leachate. However, the inability to directly capture organic nitrogen and insoluble nitrogen, and the low sorption ability of hydrochar remain key issues. To overcome these issues, we used hydrothermal assisted pretreatment of compost leachate to promote the solubilization of nitrogen contained in feces, and the conversion of organic nitrogen into ammonium nitrogen in the compost leachate. The synthesis hydrochar was activated with KOH to enhance its sorption ability, and then characterized by SEM, FTIR, elemental analysis, specific surface area, pore volume and size analysis. The content of ammonium nitrogen in hydrolysis leachate at 210 °C increased by 22.3% compared with raw compost leachate. 3D-EEM analysis indicated that aromatic protein substances were rapidly hydrolyzed to gradually increase the content of ammonium nitrogen and produce considerable humic acids. The maximum adsorption capacity of ammonium nitrogen reached 140.3 mg/g at 45 °C for KOH-activated hydrochar of 260 °C. The Langmuir isotherm and pseudo second order kinetic models were good fit for the adsorption process of ammonium nitrogen at higher temperature (35 °C or 45 °C), and this reaction was mainly dominated by chemisorption. The adsorption of ammonium nitrogen was exothermic, spontaneous, and showed an increase in disorder at the solid-liquid interface. For resource recovery, the total release amount of ammonium nitrogen of five interval extractions could reach 12.2% of maximum adsorption capacity (140.3 mg/g) under alkaline (pH 8.0) condition. The nitrogen mass balance calculation revealed that 8.9% of total nitrogen in the compost leachate could be recovered.
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JHAZMAT.2019.121378
Abstract: Thallium (Tl) is typical rare element with severe toxicity comparable to Hg and Pb. To track Tl pollution, isotopic fractionation of Tl was evaluated during pyrite smelting for sulfuric acid production. Large variations in Tl isotope compositions were observed among the pyrite ore (PO) and its four different smelting wastes. The starting raw PO had an ε
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 02-2007
DOI: 10.1016/J.CHEMOSPHERE.2006.10.017
Abstract: Heavy metal- and organic-contaminated sites are ubiquitous, but few studies have been conducted to address such an issue. EDTA- and SDS-enhanced washing was studied for remediation of Pb- and/or marine diesel fuel (MDF)-contaminated soils. The feasibility of recovery and reuse of EDTA and SDS, as well as the physicochemical interactions among the chemical agents, contaminants and soils were extensively investigated using batch experiments. The optimal washing sequence was then determined. The experimental results showed that EDTA could be recovered and reused for four cycles without significant loss of its chelating capacity, while the extraction capability of SDS was noticeably reduced after each reuse cycle. The free phase of marine diesel fuel (MDF) in soils physically isolated the sorbed Pb on soils and thus reducing its extraction by EDTA. The presence of SDS alone or together with low concentration of EDTA was found to enhance Pb removal probably via electrostatic interaction and dissolution of soil organic matter. However, it hindered Pb extraction by high concentration of EDTA, because of the potential formation of complexes between some strongly-bound Pb and SDS, that are more resistant to desorption. Therefore, EDTA washing followed by SDS achieved the highest Pb removal efficiency. On the other hand, MDF removal by SDS was significantly hindered by coexisting Pb in soils, probably because the formation of Pb-dodecyl sulfate (DS) complex would decrease the effective amount of SDS available for forming micelles in solution and enhance MDF sorption. EDTA alone or together with SDS could enhance MDF removal, but the residual MDF after EDTA-washing became more resistant to SDS removal. Consequently, SDS washing followed by EDTA is considered as the optimal washing sequence for MDF removal.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 09-2023
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.CHEMOSPHERE.2017.12.008
Abstract: The Love River and Ho-Jin River, two major urban rivers in Kaohsiung City, Taiwan, are moderately to heavily polluted because different types of improperly treated wastewaters are discharged into the rivers. In this study, sediment and river water s les were collected from two rivers to investigate the river water quality and accumulation of polycyclic aromatic hydrocarbons (PAHs) in sediments. The spatial distribution, composition, and source appointment of PAHs of the sediments were examined. The impacts of PAHs on ecological system were assessed using toxic equivalence quotient (TEQ) of potentially carcinogenic PAHs (TEQ
Publisher: Elsevier BV
Date: 03-2023
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.05.172
Abstract: Shooting range soils contain mixed heavy metal contaminants including lead (Pb), cadmium (Cd), and zinc (Zn). Phosphate (P) compounds have been used to immobilize these metals, particularly Pb, thereby reducing their bioavailability. However, research on immobilization of Pb's co-contaminants showed the relative importance of soluble and insoluble P compounds, which is critical in evaluating the overall success of in situ stabilization practice in the sustainable remediation of mixed heavy metal contaminated soils. Soluble synthetic P fertilizer (diammonium phosphate DAP) and reactive (Sechura SPR) and unreactive (Christmas Island CPR) natural phosphate rocks (PR) were tested for Cd, Pb and Zn immobilization and later their mobility and bioavailability in a shooting range soil. The addition of P compounds resulted in the immobilization of Cd, Pb and Zn by 1.56-76.2%, 3.21-83.56%, and 2.31-74.6%, respectively. The reactive SPR significantly reduced Cd, Pb and Zn leaching while soluble DAP increased their leachate concentrations. The SPR reduced the bioaccumulation of Cd, Pb and Zn in earthworms by 7.13-23.4% and 14.3-54.6% in comparison with earthworms in the DAP and control treatment, respectively. Bioaccessible Cd, Pb and Zn concentrations as determined using a simplified bioaccessibility extraction test showed higher long-term stability of P-immobilized Pb and Zn than Cd. The differential effect of P-induced immobilization between P compounds and metals is due to the variation in the solubility characteristics of P compounds and nature of metal phosphate compounds formed. Therefore, Pb and Zn immobilization by P compounds is an effective long-term remediation strategy for mixed heavy metal contaminated soils.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.CHEMOSPHERE.2018.12.028
Abstract: Emulsified polycolloid substrate (EPS) was developed and applied in situ to form a biobarrier for the containment and enhanced bioremediation of a petroleum-hydrocarbon plume. EPS had a negative zeta potential (-35.7 mv), which promoted its even distribution after injection. Batch and column experiments were performed to evaluate the effectiveness of EPS on toluene containment and biodegradation. The EPS-to-water partition coefficient for toluene (target compound) was 943. Thus, toluene had a significant sorption affinity to EPS, which caused reduced toluene concentration in water phase in the EPS/water system. Groundwater containing toluene (18 mg/L) was pumped into the three-column system at a flow rate of 0.28 mL/min, while EPS was injected into the second column to form a biobarrier. A significant reduction of toluene concentration to 0.1 mg/L was observed immediately after EPS injection. This indicates that EPS could effectively contain toluene plume and prevent its further migration to farther downgradient zone. Approximately 99% of toluene was removed after 296 PVs of operation via sorption, natural attenuation, and EPS-enhanced biodegradation. Increase in total organic carbon and bacteria were also observed after EPS supplement. Supplement of EPS resulted in a growth of petroleum-hydrocarbon degrading bacteria, which enhanced the toluene biodegradation.
Publisher: Elsevier BV
Date: 2009
DOI: 10.1016/J.CHEMOSPHERE.2008.09.006
Abstract: The effectiveness of using biodegradable EDDS (S,S-ethylenediaminedisuccinic acid) for metal extraction has drawn increasing attention in recent years. In this study, an empirical model, which utilized the initial metal distribution in soils and a set of parameter values independently determined from sequential extraction, was developed for estimating the time-dependent heavy metal extraction by EDDS from single-metal and multi-metal contaminated soils. The model simulation provided a satisfactory description of the experimental results of the 7-d extraction kinetics of Cu, Zn, and Pb in both artificially contaminated and field-contaminated soils. Thus, independent and prior assessment of extraction efficiency would be available to facilitate the engineering applications of EDDS. Furthermore, a simple empirical equation using the initial metal distribution was also proposed to estimate the extraction efficiency at equilibrium. It was found that, for the same type of soils, higher extraction efficiency was achieved in multi-metal contaminated soils than in single-metal contaminated soils. The differences were 4-9%, 9-16%, and 21-31% for Cu, Zn, and Pb, respectively, probably due to the larger proportion of exchangeable and carbonate fractions of sorbed Zn and Pb in multi-metal contaminated soils. EDDS-promoted mineral dissolution, on the other hand, was more significant in multi-metal contaminated soils as a result of the higher EDDS concentration applied to the soils of higher total metal content.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8GC02466A
Abstract: Novel and sustainable aluminium-biochar composite carries amorphous Al-oxygen species, providing Lewis acidity to catalyse isomerisation of glucose to fructose.
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.ENVINT.2019.02.045
Abstract: Long term mining activities can cause significant metal pollution in the environment, thereby showing potential risk to the paddy field. Elucidating the interfacial processes of trace metals from contaminated paddy soil to rice within the rhizosphere can provide important information on metal biogeochemistry and food safety. The current study aims to explore the spatial distribution and molecular speciation of Cu from rhizosphere to rice plant in a mining-impacted paddy soil, and reveal the possible uptake mechanisms. X-ray absorption near edge structure (XANES) analysis indicated that Cu was primarily associated with iron oxide and sulfide in soil with a minor proportion of organic complexed species. In the rice s les, Cu showed much higher concentrations in the roots than the shoots, as most Cu was sequestered in the root surface and epidermis (primarily in the form of C/N ligands bound Cu species), rather than root xylem, as identified by micro X-ray fluorescence (μ-XRF) imaging coupling with μ-XANES. By contrast, in the root xylem, thiol-S bound Cu(I) complex was observed, representing the reduced product of Cu(II) by thiol-S ligands in rice root. The absorbed Cu was probably transported from the root to the aerial part as C/N ligand bound Cu complex such as Cu-histidine like species, which was observed in the root xylem. The large retention capacity and reduction of Cu(II) in rice root alleviated Cu toxicity to rice, which was beneficial for food safety (e.g., lower concentration of Cu in rice grains). These findings showed for the first time that the uptake mechanisms by rice from field contaminated sites, which shed light on Cu detoxification process and potential remediation strategies.
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.BIORTECH.2018.09.139
Abstract: Lignin is a highly aromatic low value biomass residue, which can be utilized for chemicals, fuels and materials production. In recent years significant attention has focused on adsorbent materials from lignin. However, only 5% of available lignin is exploited worldwide, thus significant opportunities still exist for materials development. This review summarizes recent research advances in lignin-based adsorbents, with a particular emphasis on lignin, its modification and carbon materials derived from this abundant feedstock. Lignin derived activated carbons have been utilized for air pollutant adsorption (e.g. CO
Publisher: Wiley
Date: 12-2020
Abstract: The heterogeneous metal‐organic framework Bi‐BTC successfully catalyzed the synthesis of para ‐xylene from bio‐based 2,5‐dimethylfuran and acrylic acid in a promising yield (92 %), under relatively mild conditions (160 °C, 10 bar), and with a low reaction‐energy barrier (47.3 kJ mol −1 ). The proposed reaction strategy also demonstrates a remarkable versatility for furan derivatives such as furan and 2‐methylfuran.
Publisher: Springer Science and Business Media LLC
Date: 17-07-2015
DOI: 10.1007/S00249-015-1059-0
Abstract: Liposomal drug delivery systems (LDDSs) are promising tools used for the treatment of diseases where highly toxic pharmacological agents are administered. Currently, destabilising LDDSs by a specific stimulus at a target site remains a major challenge. The bacterial mechanosensitive channel of large conductance (MscL) presents an excellent candidate biomolecule that could be employed as a remotely controlled pore-forming nanovalve for triggered drug release from LDDSs. In this study, we developed superparamagnetic nanoparticles for activation of the MscL nanovalves by magnetic field. Synthesised CoFe2O4 nanoparticles with the radius less than 10 nm were labelled by SH groups for attachment to MscL. Activation of MscL by magnetic field with the nanoparticles attached was examined by the patch cl technique showing that the number of activated channels under r pressure increased upon application of the magnetic field. In addition, we have not observed any cytotoxicity of the nanoparticles in human cultured cells. Our study suggests the possibility of using magnetic nanoparticles as a specific trigger for activation of MscL nanovalves for drug release in LDDSs.
Publisher: Informa UK Limited
Date: 31-01-2019
Publisher: Elsevier BV
Date: 11-2020
Publisher: Springer Science and Business Media LLC
Date: 04-02-2020
DOI: 10.1186/S13765-020-0493-6
Abstract: Eutrophication of natural water is a universal problem. Nitrogen (N) and phosphorus (P) from agricultural runoff are the main sources of nutrient input, provided that emissions from industrial point sources (IPS) are under control. Therefore, it is of great environmental importance to reduce pollution associated with agricultural runoff as a means of regulating eutrophication levels in natural water. Numerous methods proposed for treating agricultural runoff can be classified into three categories: source control, process control, and end treatment. In this review, major technologies for N and P control from agricultural runoff are summarized along with discussion of newly proposed technologies such as biochar biomimetics and microbial catalyst. Because agricultural runoff (from farmlands to receiving waters) is a complicated pollution process, it is difficult to regulate the nutrients discharged via such process. This review will thus offer a comprehensive understanding on the overall process of agricultural runoff and eutrophication to help establish control strategies against highly complicated agricultural non-point sources.
Publisher: Elsevier BV
Date: 03-2023
Publisher: American Chemical Society (ACS)
Date: 21-03-2023
Publisher: Elsevier BV
Date: 04-2022
DOI: 10.1016/J.ENVPOL.2022.118877
Abstract: The effects of catalytic hydrothermal (HT) pretreatment on animal manure followed by the addition of hydrochar on the nutrients recovery have not yet been investigated using a combination of chemical, microscopic, and spectroscopic techniques. Therefore, a catalytic HT process was employed to pretreat swine manure without additives (manure-HT) and with H
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.BIORTECH.2017.08.044
Abstract: This study laid an emphasis on the possible employment of biochar generated from pyrolysis of chicken manure to establish a green platform for producing biodiesel. To this end, the pseudo-catalytic transesterification reaction using chicken manure biochar and waste cooking oil was investigated. Compared with a commercial porous material (SiO
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.06.095
Abstract: This study aimed to produce a high-value platform chemical, hydroxymethylfurfural (HMF), from food waste and evaluate the catalytic performance of trivalent and tetravalent metals such as AlCl
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JHAZMAT.2018.10.086
Abstract: The plant microbial fuel cell (PMFC) is a novel technology which integrates plants, microbes, and electrochemical elements together to create renewable energy. However, information regarding using the PMFC system to remediate metal-contaminated soils is still limited. In this study, we evaluate the potential of PMFC systems to remediate soils polluted by Cr(VI). We compare different plants and different electrode materials with regard to their electricity generation and Cr(VI) removals under different soil Cr(VI) concentrations. In PMFC systems, the soil pH was transformed from slightly acidic to neutral, and the electrical conductivity was reduced during operation. The removal efficiency of Cr(VI) in soils could reach 99%, and the total Cr of soils could also be reduced. The closed circuit voltage of PMFC systems of Chinese pennisetum using the graphite carbon felt as the electrodes could reach the daily average value of 469.21 mV. PMFC systems have successfully demonstrated the ability to remove Cr(VI) from soils collected from actual metal-contaminated sites. Our results suggest that using PMFCs to remediate contaminated soils is promising, and the effects of decontamination are mostly contributed by bioelectrochemical processes and plant uptake.
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.05.175
Abstract: Ageing is a common phenomenon during biochar storage and its soil application. In this study, we exposed sludge-derived biochar (SDBC) in the air under 4 °C, 22 °C, and 45 °C for 30-120 d to imitate the ageing process after SDBC production. The aged SDBC was characterized and its sorption capacities for Pb(II), Cr(V) and As(III) were compared with the fresh ones in batch sorption experiments. The results showed an increase in acidity, cation exchange capacity, and carboxyl groups of SDBC surface, but a decrease in alkalinity and Fe(III) species during ageing, indicating the oxidation. In addition, ageing for more than 30 d was found to favor the Pb(II) and As(III) sorption, because of higher density of available oxygen-containing groups. The Cr(VI) sorption was found to be compromised by the ageing, because some reducing agents for Cr(VI) reduction was consumed there. Higher temperatures accelerated the above-mentioned ageing effect. Yet, when the SDBC was applied in the heavy-metal contaminated soil, its performance would be affected by both ageing of SDBC itself as well as long-term interactions among soil components, such as colloids and solution, heavy metals, and SDBC, which require further investigation.
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JHAZMAT.2019.121240
Abstract: High-efficiency and cost-effective catalysts are critical to completely mineralization of organic contaminants for in-situ groundwater remediation via advanced oxidation processes (AOPs). The engineered biochar is a promising method for waste biomass utilization and sustainable remediation. This study engineers maize stalk (S)- and maize cob (C)-derived biochars (i.e., SB300, SB600, CB300, and CB600, respectively) with oxygen-containing functional groups as a carbon-based support for nanoscale zero-valent iron (nZVI). Morphological and physiochemical characterization showed that nZVI could be impregnated within the framework of the synthesized Fe-CB600 composite, which exhibited the largest surface area, pore volume, iron loading capacity, and Fe
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JHAZMAT.2019.121243
Abstract: Bioretention systems, as one of the most practical management operations for low impact development of water recovery, utilize different soil amendments to remove contaminants from stormwater. For the sake of urban sustainability, the utilization of amendments derived from waste materials has a potential to reduce waste disposal at landfill while improving the quality of stormwater discharge. This study investigated the efficiency of food waste compost and wood waste biochar for metal removal from synthetic stormwater runoff under intermittent flow and co-presence of colloids. Throughout intermittent infiltration of 84 pore volumes of stormwater, columns amended with compost and biochar removed more than 50-70% of influent metals, whereas iron-oxide coated sand was much less effective. Only a small portion of metals adsorbed on the compost (< 0.74%) was reactivated during the drainage of urban pipelines that do not flow frequently, owing to abundant oxygen-containing functional groups in compost. In comparison, co-existing kaolinite enhanced metal removal by biochar owing to the abundance of active sites, whereas co-existing humic acid facilitated mobilization via metal-humate complexation. The results suggest that both waste-derived compost and biochar show promising potential for stormwater harvesting, while biochar is expected to be more recalcitrant and desirable in field-scale bioretention systems.
Publisher: Elsevier BV
Date: 12-2021
Publisher: Elsevier BV
Date: 07-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1GC03600A
Abstract: Industrial-scale upcycling of waste polyethylene terephthalate (PET) plastic into porous carbon globally for CO 2 capture was verified as a multifunctional alternative to conventional CO 2 absorption and plastic waste management technologies.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Informa UK Limited
Date: 30-09-2022
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.ENVPOL.2017.09.052
Abstract: The increasing application of iron-based nanoparticles (NPs), especially high concentrations of zero-valent iron nanoparticles (nZVI), has raised concerns regarding their environmental behavior and potential ecological effects. In the environment, iron-based NPs undergo physical, chemical, and/or biological transformations as influenced by environmental factors such as pH, ions, dissolved oxygen, natural organic matter (NOM), and biotas. This review presents recent research advances on environmental transformations of iron-based NPs, and articulates their relationships with the observed toxicities. The type and extent of physical, chemical, and biological transformations, including aggregation, oxidation, and bio-reduction, depend on the properties of NPs and the receiving environment. Toxicities of iron-based NPs to bacteria, algae, fish, and plants are increasingly observed, which are evaluated with a particular focus on the underlying mechanisms. The toxicity of iron-based NPs is a function of their properties, tolerance of test organisms, and environmental conditions. Oxidative stress induced by reactive oxygen species is considered as the primary toxic mechanism of iron-based NPs. Factors influencing the toxicity of iron-based NPs are addressed and environmental transformations play a significant role, for ex le, surface oxidation or coating by NOM generally lowers the toxicity of nZVI. Research gaps and future directions are suggested with an aim to boost concerted research efforts on environmental transformations and toxicity of iron-based NPs, e.g., toxicity studies of transformed NPs in field, expansion of toxicity endpoints, and roles of laden contaminants and surface coating. This review will enhance our understanding of potential risks of iron-based NPs and proper uses of environmentally benign NPs.
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 08-2017
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.SCITOTENV.2018.03.103
Abstract: Navigational dredging is an excavation of marine/freshwater sediment to maintain channels of sufficient depth for shipping safety. Due to historical inputs of anthropogenic contaminants, sediments are often contaminated by metals/metalloids, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and other contaminants. Its disposal can present significant environmental and financial burdens. This study developed a novel and green remediation method for contaminated sediment using stabilization/solidification with calcium-rich/low-calcium industrial by-products and CO
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.SCITOTENV.2018.03.104
Abstract: Cadmium (Cd) is a highly toxic metal released into the environment through anthropogenic activities. Phytoremediation is a green technology used for the stabilization or remediation of Cd-contaminated soils. Brassica crop species can produce high biomass under a range of climatic and growing conditions, allowing for considerable uptake and accumulation of Cd, depending on species. These crop species can tolerate Cd stress via different mechanisms, including the stimulation of the antioxidant defense system, chelation, compartmentation of Cd into metabolically inactive parts, and accumulation of total amino-acids and osmoprotectants. A higher Cd-stress level, however, overcomes the defense system and may cause oxidative stress in Brassica species due to overproduction of reactive oxygen species and lipid peroxidation. Therefore, numerous approaches have been followed to decrease Cd toxicity in Brassica species, including selection of Cd-tolerant cultivars, the use of inorganic and organic amendments, exogenous application of soil organisms, and employment of plant-growth regulators. Furthermore, the coupling of genetic engineering with cropping may also help to alleviate Cd toxicity in Brassica species. However, several field studies demonstrated contrasting results. This review suggests that the combination of Cd-tolerant Brassica cultivars and the application of soil amendments, along with proper agricultural practices, may be the most efficient means of the soil Cd phytoattenuation. Breeding and selection of Cd-tolerant species, as well as species with higher biomass production, might be needed in the future when aiming to use Brassica species for phytoremediation.
Publisher: Elsevier BV
Date: 08-2022
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 11-2022
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 12-2018
Publisher: American Chemical Society (ACS)
Date: 31-05-2017
Publisher: American Chemical Society (ACS)
Date: 15-03-2022
Abstract: Biochar application is a promising strategy for the remediation of contaminated soil, while ensuring sustainable waste management. Biochar remediation of heavy metal (HM)-contaminated soil primarily depends on the properties of the soil, biochar, and HM. The optimum conditions for HM immobilization in biochar-amended soils are site-specific and vary among studies. Therefore, a generalized approach to predict HM immobilization efficiency in biochar-amended soils is required. This study employs machine learning (ML) approaches to predict the HM immobilization efficiency of biochar in biochar-amended soils. The nitrogen content in the biochar (0.3-25.9%) and biochar application rate (0.5-10%) were the two most significant features affecting HM immobilization. Causal analysis showed that the empirical categories for HM immobilization efficiency, in the order of importance, were biochar properties > experimental conditions > soil properties > HM properties. Therefore, this study presents new insights into the effects of biochar properties and soil properties on HM immobilization. This approach can help determine the optimum conditions for enhanced HM immobilization in biochar-amended soils.
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 02-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0EM00057D
Abstract: Biochar is an effective amendment for trace metal/metalloid (TM) immobilization in soils.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 23-01-2020
Publisher: American Chemical Society (ACS)
Date: 05-09-2022
Publisher: Springer Science and Business Media LLC
Date: 03-12-2013
DOI: 10.1007/S11356-013-2300-Y
Abstract: Biodegradable chelating agents ([S,S]-ethylenediamine-N,N-disuccinic acid (EDDS) and glutamic-N,N-diacetic acid (GLDA)) and natural humic substances (lignite-derived, standard, and commercially available humic acids) are potentially useful for enhancing soil remediation of timber treatment sites. This study integrated macroscopic and spectroscopic analyses to assess their influence on the distribution and chemical speciation of the remaining metals as well as their interaction with the soil surface after 48-h washing of a field-contaminated soil. The results demonstrated that EDDS and GLDA were an appealing alternative to non-biodegradable ethylenediamine-tetraacetic acid, but the three humic substances were less effective. As shown by sequential extractions, Cu was primarily extracted from the carbonate fraction while Cr and As extraction resulted from (co-)dissolution of the oxide fraction. As a result, the relative proportion of strongly bound organic matter and residual fractions increased by 7-16 %. However, it was noteworthy that the exchangeable fraction also increased by 5-11 %, signifying that a portion of the remaining metals was destabilized by chelating agents and transformed to be more labile in the treated soil. The X-ray photoelectron spectroscopy spectra confirmed the substantial removal of readily accessible Cu from the soil surface, but Cr maintained its original chemical forms of trivalent chromium oxides and iron-chromium coprecipitates, whereas As remained as arsenic trioxide entoxide and copper arsenate precipitates. On the other hand, the absence of characteristic peaks of adsorbed carboxylate groups in the Fourier-transform infrared (FTIR) spectra inferred that the extent of adsorption of chelating agents and humic substances on the bulk soil was insufficient to be characterized by FTIR analysis. These results suggested that attention should be paid to the exchangeable fraction of Cu and oxides/coprecipitates of As prior to possible on-site reuse of the treated soil.
Publisher: American Chemical Society (ACS)
Date: 24-12-2018
Publisher: Springer Science and Business Media LLC
Date: 13-10-2016
DOI: 10.1007/S11356-016-7725-7
Abstract: The present study investigated phthalate esters (PAEs) and organochlorine pesticides (OCPs) in agricultural soils and vegetables from eastern China. The concentrations of PAEs ranged from 109 to 5560 ng/g in soils and 60.1 to 2390 ng/g in cabbages, with average concentrations of 946 and 601 ng/g, respectively. The concentrations of OCPs ranged from <0.1 to 662 ng/g in soils and <0.1 to 42.8 ng/g in cabbages, with average concentrations of 134 and 11.6 ng/g, respectively. OCPs were mainly in the 0-30 cm surface soil layers, while PAEs could infiltrate in deep soil profiles to 70-80 cm layer. Potential source analysis traced the occurrence of OCPs to both historical application and current usage, whereas building materials and agricultural plastic film were possible input sources of PAEs in the ambient environment. OCPs showed no apparent effect on soil microbial communities, whereas significant negative relationship was observed between PAEs and fungi in soils (R = -0.54, p < 0.01). Human health risk assessment data revealed marginal noncarcinogenic risks and low carcinogenic risks in these soils. Notably, PAEs posed a comparable or higher risk level compared with that of OCPs. This study suggests the need for better regulation on pollution control and management of PAE-elevated sites to protect soil quality and food safety.
Publisher: Springer Science and Business Media LLC
Date: 16-07-2020
Publisher: Elsevier BV
Date: 12-2021
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 03-2019
Publisher: Springer Science and Business Media LLC
Date: 31-08-2016
DOI: 10.1007/S10653-016-9867-4
Abstract: Metal stabilization using soil amendments is an extensively applied, economically viable and environmentally friendly remediation technique. The stabilization of Pb, Zn and As in contaminated soils was evaluated using natural starfish (NSF) and calcined starfish (CSF) wastes at different application rates (0, 2.5, 5.0 and 10.0 wt%). An incubation study was conducted over 14 months, and the efficiency of stabilization for Pb, Zn and As in soil was evaluated by the toxicity characteristic leaching procedure (TCLP) test. The TCLP-extractable Pb was reduced by 76.3-100 and 91.2-100 % in soil treated with NSF and CSF, respectively. The TCLP-extractable Zn was also reduced by 89.8-100 and 93.2-100 % in soil treated with NSF and CSF, respectively. These reductions could be associated with the increased metal adsorption and the formation of insoluble metal precipitates due to increased soil pH following application of the amendments. However, the TCLP-extractable As was increased in the soil treated with NSF, possibly due to the competitive adsorption of phosphorous. In contrast, the TCLP-extractable As in the 10 % CSF treatment was not detectable because insoluble Ca-As compounds might be formed at high pH values. Thermodynamic modeling by visual MINTEQ predicted the formation of ettringite (Ca
Publisher: American Chemical Society (ACS)
Date: 09-04-2020
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.CHEMOSPHERE.2016.11.048
Abstract: Bioretention systems have been recommended as one of the best management practices for low impact development for water recycling/reuse systems. Although improvement of the stormwater quality has been reported regarding pollutants eliminations such as suspended solids and heavy metals, a substantial removal of indicator bacteria is required for possible non-potable reuse. This study investigated the efficiency of wood biochar with H
Publisher: Elsevier BV
Date: 12-2021
Publisher: American Chemical Society (ACS)
Date: 24-09-2018
Publisher: Springer Science and Business Media LLC
Date: 18-11-2022
DOI: 10.1007/S42773-022-00187-6
Abstract: Anaerobic digestion (AD) has been considered as a promising technique for food waste (FW) recycling. However, the accumulation of volatile fatty acids (VFAs) restricts the stability of anaerobic reactors. The present study investigated the use of biochar produced at different conditions (750 °C-30 min, 750 °C-60 min, 750 °C-120 min, 550 °C-60 min, 650 °C-60 min, 850 °C-60 min, 950 °C-60 min) for enhancing the AD of FW. Batch experiments showed that all the biochar increased the methane production rates and biochar obtained at 750 °C-60 min resulted in the highest enhancement by 21.5%. It was further showed surface oxygen-containing functional groups and graphitization degree of biochar were the critical factors for improving methane production. Microbial analysis showed that biochar addition formed different microbial communities, and Methanosaeta , Romboutsia , and norank_f_Anaerolineaceae were enriched, which might be correlated with direct interspecies electron transfer (DIET). This research showed biochar could enhance the AD of FW and also revealed the main characteristics of biochar relating with the enhancement of AD. Graphical Abstract
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.CHEMOSPHERE.2019.125172
Abstract: Thallium (Tl) is an extremely toxic metal with high risk. Sediment s les from a well dated sediment core retrieved from a heavily polluted urban lake were measured to assess the magnitude of Tl pollution and reveal its transfer mechanisms within the lake. The results show that the lake has experienced serious Tl pollution during the past 60 years, owing to a large influx of Tl-bearing wastes mostly from a neighboring copper (Cu) smelter. The Tl contents in the sediment core at different depths generally correlated positively with the production scale of Cu smelting activities in the past. Further mineralogical analysis on the electrostatic precipitator dust from the Cu smelter and highly-polluted s les from the sediment core by electronic microscopy and X-ray diffraction suggested that Tl was primarily bound to quartz and aluminosilicates. Large quantities of Tl were also observed in diatom frustules collected from the sediments, suggesting a potentially significant role of biogenic silicates in the uptake and transfer of Tl in the sediment-water system. The findings indicate a new and emerging pollution source of thallium arising from copper metallurgy activities. The results also highlight the necessity of strengthened monitoring and regulations towards Tl pollution in environmental systems impacted by Cu smelting activities in China and other nations.
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 07-2008
DOI: 10.1016/J.JHAZMAT.2007.11.084
Abstract: Heavy metals and organic contaminants often coexist in contaminated soils, of which the remediation requires a combined or sequential use of surfactant and chelant in chemical-enhanced soil washing. This study investigated the Pb removal by EDTA-washing in the presence of the coexisting hydrophobic organic contaminants (marine diesel fuel, MDF) or anionic surfactant (sodium dodecyl sulfate, SDS). The results of batch experiments indicated a negative impact of MDF on Pb removal, whereas a positive or negative influence of SDS depending on the molar ratio of [EDTA]:[Pb]. The surface of MDF-contaminated soil was partially covered by free-phase MDF limiting the interaction between EDTA and sorbed Pb, especially at [EDTA]:[Pb]=1:1. Despite the ability of SDS itself for extracting Pb to some extent, probably through electrostatic interaction and dissolution of soil organic matter (SOM), the addition of SDS into EDTA solution only slightly enhanced Pb removal at [EDTA]:[Pb]=1:1 but inhibited at [EDTA]:[Pb]=2:1. This may be attributed to the SOM dissolution and the potential formation of ternary surface complexes, respectively. Along the same line of reasoning, it was not surprising that the optimal sequence for Pb removal was EDTA- followed by SDS-washing rather than the reverse sequence or simultaneous EDTA- and SDS-washing.
Publisher: Elsevier BV
Date: 07-2017
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.BIORTECH.2022.127376
Abstract: Lignocellulosic paper waste constitutes a major waste stream globally, which should be valorised for chemical production. However, paper properties (e.g., feedstock composition, cellulosic crystallinity, and thermal stability/degradability) vary with raw materials and pulping processes. This study investigated levulinic acid (LA), hydroxymethylfurfural (HMF), and furfural production by H
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.CHEMOSPHERE.2013.09.097
Abstract: Utilising locally available industrial by-products for in situ metal stabilisation presents a low-cost remediation approach for contaminated soil. This study explored the potential use of inorganic (acid mine drainage (AMD) sludge and zero-valent iron) and carbonaceous materials (green waste compost, manure compost, and lignite) for minimising the environmental risks of As and Cu at a timber treatment site. After 9-month soil incubation, significant sequestration of As and Cu in soil solution was accomplished by AMD sludge, on which adsorption and co-precipitation could take place. The efficacy of AMD sludge was comparable to that of zero-valent iron. There was marginal benefit of adding carbonaceous materials. However, in a moderately aggressive environment (Toxicity Characteristic Leaching Procedure), AMD sludge only suppressed the leachability of As but not Cu. Therefore, the provision of compost and lignite augmented the simultaneous reduction of Cu leachability, probably via surface complexation with oxygen-containing functional groups. Under continuous acid leaching in column experiments, combined application of AMD sludge with compost proved more effective than AMD sludge with lignite. This was possibly attributed to the larger amount of dissolved organic matter with aromatic moieties from lignite, which may enhance Cu and As mobility. Nevertheless, care should be taken to mitigate ecological impact associated with short-term substantial Ca release and continuous release of Al at a moderate level under acid leaching. This study also articulated the engineering implications and provided recommendations for field deployment, material processing, and assessment framework to ensure an environmentally sound application of reactive materials.
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.SCITOTENV.2018.05.298
Abstract: This study is a comparison of the effect of biochar produced by bioenergy systems, via the pyrolysis and gasification processes, on the immobilization of metals/metalloids in soil. Because the processes for these two techniques vary, the feedstocks undergo different heating regimens and, as a result, their respective char products exhibit different physico-chemical properties. Therefore, this study focuses on (1) the characterization of derivative biochar from the bioenergy system to understand their features and (2) an exploration of various biochar impacts on the mobility of As and Pb in contaminated soil. The results showed bioenergy biochars (BBCs) performed well in mitigating Pb extractability (1 M ammonium acetate) with a Pb immobilization >80%, but unfavorably mobilized the bioavailable As, likely because of electrostatic repulsion and ion exchange competition. The BBC surface functional group would chemically bond with the As and remain stable against the pH change. An increment in aromatic carbon would effectively enhance cation-π interaction for Pb immobilization. Nevertheless, an amendment with richer condensed structure and higher inorganic minerals (Ca
Publisher: Elsevier BV
Date: 08-2018
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.ENVINT.2019.02.019
Abstract: Shale gas extraction via horizontal drilling and hydraulic fracturing (HF) has enhanced gas production worldwide, which has altered global energy markets and reduced the prices of natural gas and oil. Water management has become the most challenging issue of HF, as it demands vast amounts of freshwater and generates high volumes of complex liquid wastes contaminated by erse potentially toxic elements at variable rates. This critical review focuses on characterizing HF wastewater and establishing strategies to mitigate environmental impacts. High prioritization was given to the constituents with mean concentrations over 10 times greater than the maximum contamination level (MCL) guidelines for drinking water. A number of potentially harmful organic compounds in HF wastewaters were identified via the risk quotient approach to predict the associated toxicity for freshwater organisms in recipient surface waters. Currently, two options for HF wastewater treatment are preferred, i.e., disposal by deep well injection or on-site re-use as a fracturing fluid. Supplementary treatment will be enforced by increasingly rigorous regulations. Partial treatment and reuse remain the preferred method for managing HF wastewater where feasible. Otherwise, advanced technologies such as membrane separation/distillation, forward osmosis, mechanical vapor compression, electrocoagulation, advanced oxidation, and adsorption-biological treatment will be required to satisfy the sustainable requirements for reuse or surface discharge.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JHAZMAT.2018.11.067
Abstract: Disposal of significant amounts of dredged contaminated sediment poses an economic and environmental problem worldwide. Transforming contaminated sediment into value-added construction materials using low-carbon MgO cement is a sustainable option however, the weak mechanical strength and unreliable water-solubility of MgO cement restrict its practical engineering applications. This study elucidates the potential role of industrial Si-rich minerals in the performance enhancement of MgO-based products via the promotion of magnesium silicate hydrate (M-S-H) gel formation. Quantitative X-ray diffraction and
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 06-2010
DOI: 10.1016/J.CHEMOSPHERE.2010.03.033
Abstract: Biodegradable EDDS ([S,S]-ethylenediaminedisuccinic acid) has been suggested for enhancing heavy metal extraction from contaminated soils. Recent studies showed that Zn and Pb are less effectively extracted due to metal exchange and re-adsorption onto the soil surfaces, especially for EDDS-deficiency conditions. This study therefore investigated the influence of dissolved organic matter and the co-presence of EDTA (ethylene-diamine-tetraacetic acid) on metal extraction from an artificially contaminated sandy soil under deficient amount of chelants in batch kinetics experiments. The addition of 10 and 20mgL(-1) of humic acid as dissolved organic matter (DOC) suppressed metal extraction by EDDS, probably resulting from the competition of adsorbed humic acid for heavy metals and adsorption of metal-humate complexes onto the soil surfaces. The effects were most significant for Pb because of greater extent of metal exchange of PbEDDS and high affinity towards organic matter. Thus, one should be cautious when there is a high content of organic matter in soils or groundwater. On the other hand, compared to in idual additions of EDDS or EDTA, the equimolar EDDS and EDTA mixture exhibited significantly higher Pb extraction without notable Pb re-adsorption. The synergistic performance of the EDDS and EDTA mixture probably resulted from the change of chemical speciation and thus less competition among Cu, Zn and Pb for each chelant. These findings suggest further investigation into an optimum chemistry of the chelant mixture taking into account the effectiveness and associated environmental impact.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.SCITOTENV.2018.11.282
Abstract: Production temperature significantly affects biochar properties and consequently the removal mechanisms of heavy metals. In this study, rice straw biochars were produced at 300, 500 and 700 °C (RSB300, RSB500 and RSB700). The influence of production temperature on the adsorption characteristics and removal mechanisms of lead on this set of rice straw biochars were investigated by batch adsorption tests, micro-structural analyses and sequential metal extractions. Biochars produced at higher temperatures had significantly higher pH values and surface areas, resulting in higher metal removal capacities and faster uptake kinetics. Precipitation was a key mechanism for lead removal from solution for all biochars: lead oxalate was precipitated on RSB300, and hydrocerussite was precipitated on RSB500 and RSB700. The immobilized lead fraction on the biochars could be ided into exchangeable, acid soluble and non-available fractions. RSB300 had 11.34% of the total immobilized Pb attributed to the exchangeable fraction, whereas for RSB500 and RSB700, it was 99%). Based on our results, RSB500 and RSB700 are likely much more appropriate for soil remediation of Pb as compared with RSB300.
Publisher: American Chemical Society (ACS)
Date: 03-11-2020
Publisher: Hindawi Limited
Date: 21-11-2013
DOI: 10.1155/2013/698031
Abstract: During acid mine drainage (AMD) treatment by alkaline reagent neutralisation, Ni and Zn are partially removed via sorption to Fe and Al hydroxide precipitates. This research evaluated the effect of surface area of precipitates, formed by neutralisation of AMD using three alkalinity reagents (NaOH, Ca(OH) 2 , and CaCO 3 ), on the sorption of Ni and Zn. The BET surface area of the precipitates formed by neutralisation of AMD with NaOH (173.7 m 2 g −1 ) and Ca(OH) 2 (168.2 m 2 g −1 ) was an order of magnitude greater than that produced by CaCO 3 neutralisation (16.7 m 2 g −1 ). At pH 6.5, the residual Ni concentration was 0.32 and 0.41 mg L −1 for NaOH and Ca(OH) 2 neutralised AMD, respectively, resulting in up to 60% lower Ni concentrations than achieved by CaCO 3 neutralisation which had no effect on Ni removal. The residual Zn concentration was even more dependent on precipitate surface area for NaOH and Ca(OH) 2 neutralised AMD (0.33 and 1.02 mg L −1 ), which was up to 85% lower than the CaCO 3 neutralised AMD (2.20 mg L −1 ). These results suggest that the surface area of precipitated flocs and the selection of neutralising reagent critically affect the sorption of Ni and Zn during AMD neutralisation.
Publisher: Elsevier BV
Date: 05-2022
DOI: 10.1016/J.JHAZMAT.2022.128503
Abstract: Microplastic (MP), an emerging contaminant, is globally prevalent and poses potential environmental threats and ecological risks to both aquatic and terrestrial ecosystems. When MPs enter into natural environments, they may serve as artificial substrates for microbial colonization and plastisphere formation, providing new ecological niches for microorganisms. Recent studies of the plastisphere have focused on aquatic ecosystems. However, our understanding of the soil plastisphere e.g. its formation process, microbial ecology, co-transport of organic pollutants and heavy metals, and effects on biogeochemical processes is still very limited. This review summarizes latest methods used to explore the soil plastisphere, assesses the factors influencing the microbial ecology of the soil plastisphere, and sheds light on potential ecological risks caused by the soil plastisphere. The formation and succession of soil plastisphere communities can be driven by MP characteristics and soil environmental factors. The soil plastisphere may affect a series of ecological processes, especially the co-transport of environmental contaminants, biodegradation of MPs, and soil carbon cycling. We aim to narrow the knowledge gap between the soil and aquatic plastisphere, and provide valuable guidance for future research on the soil plastisphere in MP-contaminated soils.
Publisher: Elsevier BV
Date: 07-2018
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JHAZMAT.2019.121455
Abstract: Biochar as a soil amendment could be involved in redox process of elements which would be affected by soil-redox-active components including minerals and organic acids. This study evaluated the effects of Fe mineral and lactate on reducing capacity of biochar for Cr(VI) reduction and the underlying mechanisms. Fe minerals inhibited the reduction of Cr(VI) by biochar, with the decrease of Cr(VI) reduction rate constant obtained by pseudo first-order reaction model from 2.18 to 2.47 × 10
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.CHEMOSPHERE.2017.12.151
Abstract: With the increasing application of hydraulic fracturing, it is urgent to develop an effective and economically feasible method to treat the large volumes of fracturing wastewater. In this study, bare and entrapped nanoscale zero-valent iron (nZVI) were introduced for the removal of carbon tetrachloride (CT) and 1,1,2-trichloroethane (TCA) in model high-salinity fracturing wastewater. With increasing ionic strength (I) from Day-1 (I = 0.35 M) to Day-90 (I = 4.10 M) wastewaters, bare nZVI presented significantly lower removal efficiency of CT (from 53.5% to 38.7%) and 1,1,2-TCA (from 71.1% to 21.7%) and underwent more serious Fe dissolution from 1.31 ± 1.19% in Day-1 to 5.79 ± 0.32% in Day-90 wastewater. Particle aggregation induced by high ionic strength was primarily responsible for the lowered performance of nZVI due to less available reactive sites on nZVI surface. The immobilization of nZVI in alginate with/without polyvinyl alcohol provided resistance to particle aggregation and contributed to the superior performance of entrapped nZVI in Day-90 wastewater for 1,1,2-TCA removal (62.6-72.3%), which also mitigated Fe dissolution (4.00-4.69%). Both adsorption (by polymer matrix) and reduction (by immobilized nZVI) were involved in the 1,1,2-TCA removal by entrapped nZVI. However, after 1-month immersion in synthetic fracturing wastewater, a marked drop in the reactivity of entrapped nZVI for 1,1,2-TCA removal from Day-90 wastewater was observed with significant release of Na and total organic carbon. In summary, bare nZVI was sensitive to the nature of the fracturing wastewater, while the use of environmentally benign entrapped nZVI was more promising for wastewater treatment.
Publisher: Elsevier BV
Date: 12-2022
Publisher: American Chemical Society (ACS)
Date: 02-03-2019
Abstract: Biochars have demonstrated great potential for water decontamination and soil remediation however, their redox reactivity toward trace contaminants and the corresponding redox-active moieties (RAMs, i.e., phenolic -OH, semiquinone-type persistent free radicals (PFRs), and quinoid C═O) remain poorly understood. Here we investigated the roles of the RAMs on biochar in oxidation of As(III) under varying pH and O
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.SCITOTENV.2017.10.193
Abstract: During the past decade, biochar has attracted immense scientific interest for agricultural and environmental applications. A broad range of biochars with advantageous properties (e.g., high surface area, flexible architecture, and high porosity) has been developed for pollution abatement. Nevertheless, biochar suffers from certain drawbacks (e.g., limited sorption capacity for anions and poor mechanical properties) that limit their practical applicability. This review focuses on recent advancements in biochar technology, especially with respect to its technical aspects, the variables associated with removing phosphates from water, and the challenges for such abatement. The attention paid to the specific remediation of phosphate from water using biochar is limited (n=1114 - Scopus) compared to the application of biochar to other common water pollutants (n=3998 - Scopus). The subject warrants immediate rigorous research because of the undesirable effects of excess phosphate in water bodies. This review will thus facilitate the construction of a roadmap for further developments and the expansion of this challenging area of research.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.BIORTECH.2019.02.105
Abstract: Due to abundant biomass and eco-friendliness, biochar is exemplified as one of the most promising candidates to mediate the degradation of environmental contaminants. Recently, environmentally persistent free radicals (EPFRs) have been detected in biochars, which can activate S
Publisher: Informa UK Limited
Date: 07-05-2022
Publisher: Elsevier BV
Date: 02-2018
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.BIORTECH.2019.122497
Abstract: Research attention is increasingly drawn on constructing a circular bioeconomy and enhancing the value of material flows. Circular bioeconomy aims to achieve sustainable consumption and production with reduction of greenhouse gas emission. This study identifies research gaps on how circular bioeconomy can be achieved through sustainable food waste management by comparing the similarities and differences in concepts of bioeconomy and circular economy, reviewing the benefits and limitations of the existing policies, and evaluating the global situations of food waste and its management on household and commercial basis to promote circular bioeconomy. Future development on food waste management is expected to capitalise on the multi-functionality of products, boundary and allocation in a circular system, and trade-off between food waste and resources. With future technological advances, food waste management in circular bioeconomy policy can facilitate the accomplishment of sustainable development goals.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.ENVPOL.2017.09.040
Abstract: The behaviour of arsenic (As) from geogenic soil exposed to aerobic conditions is critical to predict the impact of As on the environment, which processes remain unresolved. The current study examined the depth profile of As in geologically derived subsoil cores from Hong Kong and investigated the mobilization, plant availability, and bioaccessibility of As in As-contaminated soil at different depths (0-45.8 m). Results indicated significant heterogeneity, with high levels of As in three layers of soil reaching up to 505 mg/kg at a depth of 5 m, 404 mg/kg at a depth of 15 m, and 1510 mg/kg at a depth of 27-32 m. Arsenic in porewater s les was <11.5 μg/L in the study site. X-ray absorption spectroscopy (XAS) indicated that main As species in soil was arsenate (As(V)), as adsorbed fraction to Fe oxides (41-69% on goethite and 0-8% on ferrihydrite) or the mineral form scorodite (30-57%). Sequential extraction procedure demonstrated that 0.5 ± 0.4% of As was exchangeable. Aerobic incubation experiments exhibited that a very small amount (0.14-0.48 mg/kg) of As was desorbed from the soil because of the stable As(V) complex structure on abundant Fe oxides (mainly goethite), where indigenous microbes partly (59 ± 18%) contributed to the release of As comparing with the sterilized control. Furthermore, no As toxicity in the soil was observed with the growth of ryegrass. The bioaccessibility of As was <27% in the surface soil using simplified bioaccessibility extraction test. Our systematic evaluation indicated that As in the geogenic soil profile from Hong Kong is relatively stable exposing to aerobic environment. Nevertheless, children and workers should avoid incidental contact with excavated soil, because high concentration of As was present in the digestive solution (<0.1-268 μg/L).
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.05.019
Abstract: Geogenic sources of arsenic (As) have aroused extensive environmental concerns in many countries. This study evaluated the vertical profiles, leaching characteristics, and surface characteristics of As-containing soils in Hong Kong. The results indicated that elevated levels of As (486-1985 mg kg
Publisher: Elsevier BV
Date: 06-2009
DOI: 10.1016/J.CHEMOSPHERE.2009.02.058
Abstract: The influence of natural organic matter on contaminant removal by Fe(0) systems has been of increasing concern. Recent studies have shown that, in addition to direct sorption on the Fe(0) surfaces, humic acid complexation with dissolved iron released from corrosion results in the formation of colloids and aggregates in solution that may affect contaminant removal. High-pressure size-exclusion chromatographic analyses revealed increasing molecular weights of dissolved humic acids with reaction time. Humic acid aggregation occurred across a wide range of molecular weight fractions. Fourier transform infrared spectroscopic analysis of humic acid aggregates suggested the presence of inner-sphere complexation involving different oxygen-containing functional groups hydrophobic interactions also probably contributed to aggregation as the humic acid of more aromatic and hydrophobic character was aggregated at a faster rate. Because of multiple underlying processes, a variety of cross-correlated physicochemical properties of humic acids contributed to their aggregation. The presence of humic acid aggregates provided an additional hydrophobic domain for partitioning that enhanced trichloroethylene removal, although steric blocking of the Fe(0) surfaces may inhibit its reduction to some extent. Comparable effects were demonstrated for various types of humic acids.
Publisher: Elsevier BV
Date: 2023
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.CHEMOSPHERE.2017.11.128
Abstract: In idual and combined toxicities of endosulfan (ENDO) with phenanthrene (PHE) were evaluated using zebrafish (Danio rerio) adults. The 96-h LC
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.JHAZMAT.2019.121208
Abstract: Contaminated mining sites require ecological restoration work, of which phytoremediation using appropriate plant species is an attractive option. Our present study is focused on one typical contaminated mine site with indigenous plant cover. The X-ray absorption near edge structure (XANES) analysis indicated that Cu (the major contaminant) was primarily associated with goethite (adsorbed fraction), with a small amount of Cu oxalate-like species (organic fraction) in mine affected soil. With growth of plant species like Miscanthus floridulus and Stenoloma chusanum, the Cu-oxalate like organic species in rhizosphere soil significantly increased, with corresponding decrease in Cu-goethite. In the root cross-section of Miscanthus floridulus, synchrotron-based micro-X-ray fluorescence (μ-XRF) microscopy and micro-XANES results indicated that most Cu was sequestered around the root surface/epidermis, primarily forming Cu alginate-like species as a Cu-tolerance mechanism. From the root epidermis to the cortex and vascular bundle, more Cu(I)-glutathione was observed, suggesting reductive detoxification ability of Cu(II) to Cu(I) during the transport of Cu in the root. The observation of Cu-histidine in root internal cell layers showed another Cu detoxification pathway based on coordinating amino ligands. Miscanthus floridulus showed ability to accumulate phosphorous and nitrogen nutrients in rhizosphere and may be an option for in situ phytostabilization of metals in contaminated mining area.
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.ENVPOL.2022.119527
Abstract: Understanding the arsenic (As) enrichment mechanisms in the subsurface environment relies on a systematic investigation of As valence species and their partitioning with the Fe (oxyhydr)oxide phases in the subsoil profile. The present study explored the distribution, speciation, partitioning, and (im)mobilization of As associated with Fe in four subsoil cores (∼30 m depth) from Hong Kong using sequential chemical extraction and X-ray absorption near edge spectroscopy. The subsoil profiles exhibited relatively high concentrations of As at 26.1-982 mg/kg (median of 112 mg/kg), and the As was dominated by As(V) (85-96%) and primarily associated with the residual fraction (50.7-94.7%). A small amount of As (0.002-13.2 mg/kg) was easily mobilized from the four subsoil profiles, and a concentration of water-soluble As higher than 100 μg/L was observed for only some subsoil layers. The molar ratios of As:Fe in the oxalate-extractable Fe fraction ranged from 1.2 to 76.5 mmol/mol (median of 11.1 mmol/mol), revealing the participation of poorly crystalline Fe (oxyhydr)oxides in immobilizing most of the high geogenic As. The primary phases of ferric (oxyhydr)oxides were characterized as ferrihydrite (16-53%), lepidocrocite (0-32%), and goethite (0-62%), and these phases contributed to the sufficient ability of the subsoil to sequester 45.3-100% (median of 98.8%) of the exogenous As(V) (1.0 mg/L) in adsorption experiments. In contrast to As(V), exogenous As(III) showed a lower removal percentage (3.9-79.1%, median of 45.1%). The study revealed that the chemical speciation of As and Fe in the subsoil profiles is useful for predicting the immobilization of high geogenic As in the region, which is also helpful for the safe utilization of As-containing soil during land development worldwide.
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.JHAZMAT.2021.127369
Abstract: Low-carbon stabilization/solidification (S/S) is of increasing importance as an option for the treatment of municipal solid waste incineration fly ash (MIFA). This study tailored four binders (e.g., ordinary Portland cement (OPC), calcium aluminate cement (CAC), phosphate-modified OPC, and phosphate-modified CAC) for S/S of MIFA and evaluated the cytotoxicity of treated MIFA by using A549 cell-based in-vitro assay. After S/S treatment, the leachability of Cr, Cu, Zn and Pb from MIFA decreased by 76.1%, 93.4%, 69.6%, and 85.5%, respectively. Spectroscopic analysis indicated that the hydration products determined the immobilization efficiencies of various binders, and strong bonding between metallic cations and phosphate enhanced the immobilization efficiency. The treated MIFA showed significantly lower cellular reactive oxygen species (ROS)-inducing abilities than original MIFA, in which with phosphate-modified OPC treated MIFA showed the lowest ROS levels. Intracellular ROS and multicytotoxicity results also revealed that the treated MIFA not only decreased the cytotoxicity-inducing capability but also enhanced the tolerant dosage of cytotoxicity, in which phosphate-modified S/S treatments showed more effective mitigation (25% less cytotoxicity) than plain cement treatments due to the high-efficiency immobilization of potentially toxic elements. This study develops a pioneering assessment protocol to measure the success of sustainable treatment of MIFA in human health perspective.
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.05.013
Abstract: Cadmium (Cd) accumulation in vegetables is an important environmental issue that threatens human health globally. Understanding the response of vegetables to Cd stress and applying management strategies may help to reduce the Cd uptake by vegetables. The aim of the present review is to summarize the knowledge concerning the uptake and toxic effects of Cd in vegetables and the different management strategies to combat Cd stress in vegetables. Leafy vegetables grown in Cd contaminated soils potentially accumulate higher concentrations of Cd, posing a threat to food commodities. The Cd toxicity decreases seed germination, growth, biomass and quality of vegetables. This reduces the photosynthesis, stomatal conductance and alteration in mineral nutrition. Toxicity of Cd toxicity also interferes with vegetable biochemistry causing oxidative stress and resulting in decreased antioxidant enzyme activities. Several management options have been employed for the reduction of Cd uptake and toxicity in vegetables. The exogenous application of plant growth regulators, proper mineral nutrition, and the use of organic and inorganic amendments might be useful for reducing Cd toxicity in vegetables. The use of low Cd accumulating vegetable cultivars in conjunction with insolubilizing amendments and proper agricultural practices might be a useful technique for reducing Cd exposure in the food chain.
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JHAZMAT.2019.121321
Abstract: The degradation of di-(2-ethylhexyl) phthalate (DEHP) was examined as an ex le to capitalize on the potential interactions of peroxydisulfate (PS) and ferrous iron (Fe
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.ENVINT.2019.03.040
Abstract: Mercury (Hg) is a highly toxic element, which is frequently enriched in flooded soils due to its anthropogenic release. The mobilization of Hg and its species is of ultimate importance since it controls the transfer into the groundwater and plants and finally ends in the food chain, which has large implications on human health. Therefore, the remediation of those contaminated sites is an urgent need to protect humans and the environment. Often, the stabilization of Hg using amendments is a reliable option and biochar is considered a candidate to fulfill this purpose. We tested two different pine cone biochars pyrolyzed at 200 °C or 500 °C, respectively, with a view to decrease the mobilization of total Hg (Hg
Publisher: Elsevier BV
Date: 05-2018
DOI: 10.1016/J.WATRES.2018.01.055
Abstract: Iron redox cycle plays a primary role in controlling the mobility of P in sediments. It is crucial to better understand how lanthanum (La) modified bentonite (LMB, Phoslock
Publisher: Elsevier BV
Date: 11-2018
Publisher: Wiley
Date: 19-08-2019
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.CHEMOSPHERE.2022.134426
Abstract: The use of biochar to recover nitrogen and phosphorus from wastewater especially source-separated human urine is attractive from both economic and environmental standpoints. The widespread use of pharmaceuticals has raised concerns as they are not fully metabolized and ended up in human urine. The objective of this study is to examine adsorption of antibiotics (azithromycin, ciprofloxacin, sulfamethoxazole, trimethoprim, and tetracycline) and nutrients (ammonium and phosphate) in source-separated human urine by biochar and subsequent desorption. Batch adsorption experiments were conducted using biochar prepared from oak wood (OW) and paper mill sludge (PMS) to elucidate the effects of adsorption time, pH, and adsorbent dose. The desorption of adsorbed nutrients and antibiotics was also investigated. While the nutrient adsorption was more favorable by the PMS biochar, antibiotic adsorption was more prolific by the OW biochar. Hydrogen bonding and π-π interaction were identified as potential adsorption mechanisms. Experimental results agree with the Freundlich isotherm and pseudo-second order models (except the OW biochar for the kinetics). The findings suggest that biochar can adsorb both nutrients (43.30-266.67 mg g
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.SCITOTENV.2016.11.141
Abstract: Hydraulic fracturing has advanced the development of shale gas extraction, while inadvertent spills of flowback water may pose a risk to the surrounding environment due to its high salt content, metals/metalloids (As, Se, Fe and Sr), and organic additives. This study investigated the potential impact of flowback water on four representative soils from shale gas regions in Northeast China using synthetic flowback solutions. The compositions of the solutions were representative of flowback water arising at different stages after fracturing well establishment. The effects of solution composition of flowback water on soil ecosystem were assessed in terms of metal mobility and bioaccessibility, as well as biological endpoints using Microtox bioassay (Vibrio fischeri) and enzyme activity tests. After one-month artificial aging of the soils with various flowback solutions, the mobility and bioaccessibility of As(V) and Se(VI) decreased as the ionic strength of the flowback solutions increased. The results inferred a stronger binding affinity of As(V) and Se(VI) with the soils. Nevertheless, the soil toxicity to Vibrio fischeri only presented a moderate increase after aging, while dehydrogenase and phosphomonoesterase activities were significantly suppressed with increasing ionic strength of flowback solutions. On the contrary, polyacrylamide in the flowback solutions led to higher dehydrogenase activity. These results indicated that soil enzyme activities were sensitive to the composition of flowback solutions. A preliminary human health risk assessment related to As(V) suggested a low level of cancer risk through exposure via ingestion, while holistic assessment of environmental implications is required.
Publisher: Springer Science and Business Media LLC
Date: 06-10-2017
DOI: 10.1007/S11356-017-0266-X
Abstract: Cement-based stabilization/solidification (S/S) is a practical treatment approach for hazardous waste with anthropogenic As sources however, its applicability for geogenic As-containing soil and the long-term leaching potential remain uncertain. In this study, semi-dynamic leaching test was performed to investigate the influence of S/S binders (cement blended with fuel ash (FA), furnace bottom ash (FBA), or ground granulated blast furnace slag (GGBS)) on the long-term leaching characteristics of geogenic As. The results showed that mineral admixtures with higher Ca content and pozzolanic activity were more effective in reducing the leached As concentrations. Thus, cement blended with FBA was inferior to other binders in suppressing the As leaching, while 20% replacement of ordinary Portland cement by GGBS was considered most feasible for the S/S treatment of As-containing soils. The leachability of geogenic As was suppressed by the encapsulation effect of solidified matrix and interlocking network of hydration products that were supported by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results. The long-term leaching of geogenic As from the monolithic s les was diffusion-controlled. Increasing the Ca content in the s les led to a decrease in diffusion coefficient and an increase in feasibility for "controlled utilization" of the S/S-treated soils.
Publisher: Elsevier BV
Date: 12-2018
Publisher: Elsevier BV
Date: 02-2023
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JHAZMAT.2019.121192
Abstract: A high-performance carbon electrode is desirable for promoting electrochemical desalination efficiency in the membrane capacitive deionization (MCDI). Sugarcane bagasse (food waste) was employed in this study to prepare hierarchically porous biochars by microwave-assisted carbonization and activation with potassium hydroxide in N
Publisher: Springer Science and Business Media LLC
Date: 20-03-2015
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.ENVRES.2020.109156
Abstract: The selective degradation of recalcitrant antibiotics into byproducts with low toxicity and high biodegradability has been increasingly popular using peroxymonosulfate (PMS) based advanced oxidation processes (AOPs). In this paper, two Fe-based heterogeneous catalysts, bentonite supported Fe-Ni composite (BNF) and biochar-supported Fe composite (Fe/C), were tailored and comprehensively characterized for distinctive physicochemical properties, crystalline structures, and interfacial behaviors. Two widely used antibiotics, sulfapyridine (SPY) and oxytetracycline (OTCs) at their common concentrations in pharmaceutical wastewaters (250 and 10 mg L
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.ENVINT.2019.03.031
Abstract: Exchangeable lead (Pb) extracted by ammonium acetate from three independent incubation studies was assessed to understand the influence of feedstock, pyrolysis temperatures, and production conditions on Pb immobilization capacities of different biochars. Vegetable waste biochar, pine cone, wood bark, cocopeat, red pepper stalk, and palm kernel shell were used as feedstocks (food supply and agricultural wastes) to produce biochars at 200-650 °C with and without N
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.SCITOTENV.2018.04.406
Abstract: To date, studies on the mobility of arsenic (As) in soil amended with biochar have primarily relied on broad empirical observations, resulting in a gap between the behavior of As in amended soil and the chemical mechanisms controlling that behavior. This study focuses on the influence of abiotic factors in As mobility in As-contaminated soils amended with biochar. In order to understand the leaching of DOC and phosphate across a range of biomass feedstock and pyrolysis temperature, rice straw and granular sludge from an anaerobic digester were pyrolyzed at 300, 550, and 700 °C, and subjected to leaching studies by mixing air dried soil with 10 wt% of biochar at a soil: water ratio of 1:1(w/v). The concentration of DOC in the presence of granular sludge biochar and rice straw biochar increased from 190 mg L
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.SCITOTENV.2018.06.357
Abstract: A new and environmentally benign photocatalyst is introduced in this study, which was synthesized via incipient wetness impregnation onto MIL-47(V) using an ethanolic Fe(III) chloride solution. The resultant materials were characterized by XRD, FE-SEM, and HR-TEM analyses. The photocatalytic capability of Fe/MIL-47 towards removal of methylene blue (MB) was evaluated in comparison to MIL-53(Al), Cu/MIL-47, and Fe/zeolite-Y. The unmodified MIL-47 achieved 55% MB removal after 20-min exposure to UV/H
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.ENVINT.2019.03.022
Abstract: Rare earth elements (REEs) are gaining attention due to rapid rise of modern industries and technological developments in their usage and residual fingerprinting. Cryptic entry of REEs in the natural resources and environment is significant therefore, life on earth is prone to their nasty effects. Scientific sectors have expressed concerns over the entry of REEs into food chains, which ultimately influences their intake and metabolism in the living organisms. Extensive scientific collections and intensive look in to the latest explorations agglomerated in this document aim to depict the distribution of REEs in soil, sediments, surface waters and groundwater possibly around the globe. Furthermore, it draws attention towards potential risks of intensive industrialization and modern agriculture to the exposure of REEs, and their effects on living organisms. It also draws links of REEs usage and their footprints in natural resources with the major food chains involving plants, animals and humans. Scientific literature preferably spanning over the last five years was obtained online from the MEDLINE and other sources publishing the latest studies on REEs distribution, properties, usage, cycling and intrusion in the environment and food-chains. Distribution of REEs in agricultural soils, sediments, surface and ground water was drawn on the global map, together with transport pathways of REEs and their cycling in the natural resources. Fourteen REEs (Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Th and Yb) were plighted in this study. Wide range of their concentrations has been detected in agricultural soils (<15.9-249.1 μg g This review article precisely narrates the current status, sources, and potential effects of REEs on plants, animals, humans health. There are also a few ex les where REEs have been used to benefit human health. However, still there is scarce information about threshold levels of REEs in the soil, aquatic, and terrestrial resources as well as living entities. Therefore, an aggressive effort is required for global action to generate more data on REEs. This implies we prescribe an urgent need for inter-disciplinary studies about REEs in order to identify their toxic effects on both ecosystems and organisms.
Publisher: Elsevier BV
Date: 06-2018
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.BIORTECH.2016.08.002
Abstract: This study aimed to transform food waste into a value-added chemical, hydroxymethylfurfural (HMF), and unravel the tangled effects induced by the metal catalysts on each single step of the successive conversion pathway. The results showed that using cooked rice and bread crust as surrogates of starch-rich food waste, yields of 8.1-9.5% HMF and 44.2-64.8% glucose were achieved over SnCl4 catalyst. Protons released from metal hydrolysis and acidic by-products rendered Brønsted acidity to catalyze fructose dehydration and hydrolysis of glycosidic bond. Lewis acid site of metals could facilitate both fructose dehydration and glucose isomerization via promoting the rate-limiting internal hydride shift, with the catalytic activity determined by its electronegativity, electron configuration, and charge density. Lewis acid site of a higher valence also enhanced hydrolysis of polysaccharide. However, the metals also catalyzed undesirable polymerization possibly by polarizing the carbonyl groups of sugars and derivatives, which should be minimized by process optimization.
Publisher: Elsevier BV
Date: 10-2017
Publisher: Elsevier BV
Date: 03-2020
Publisher: Springer Science and Business Media LLC
Date: 14-01-2014
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.BIORTECH.2022.127694
Abstract: The process water (PW) from acid-catalyzed hydrothermal carbonization (HTC) is still an environmental burden due to the enriched organics, nutrients, and salts. This study proposed a novel strategy to valorize food waste digestate into multifunctional hydrochar by recirculating the PW in the HCl-catalyzed HTC process. The produced multifunctional hydrochar could be utilized as a high-quality solid fuel with HHV of 27.9 MJ kg
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.CHEMOSPHERE.2014.11.071
Abstract: Navigational/environmental dredging of contaminated sediment conventionally requires contained marine disposal and continuous monitoring. This study proposed a green remediation approach to treat and recycle the contaminated sediment by means of stabilization/solidification enhanced by the addition of selected solid wastes. With an increasing amount of contaminated sediment (20-70%), the 28-d compressive strength of sediment blocks decreased from greater than 10MPa to slightly above 1MPa. For augmenting the cement hydration, coal fly ash was more effective than lime and ground seashells, especially at low sediment content. The microscopic and spectroscopic analyses showed varying amounts of hydration products (primarily calcium hydroxide and calcium silicate hydrate) in the presence of coal fly ash, signifying the influence of pozzolanic reaction. To facilitate the waste utilization, cullet from beverage glass bottles and bottom ashes from coal combustion and waste incineration were found suitable to substitute coarse aggregate at 33% replacement ratio, beyond which the compressive strength decreased accordingly. The mercury intrusion porosimetry analysis indicated that the increase in the total pore area and average pore diameter were linearly correlated with the decrease of compressive strength due to waste replacement. All the sediment blocks complied with the acceptance criteria for reuse in terms of metal leachability. These results suggest that, with an appropriate mixture design, contaminated sediment and waste materials are useful resources for producing non-load-bearing masonry units or fill materials for construction uses.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.BIORTECH.2018.05.022
Abstract: Pollution of water by single antibiotics has been investigated in depth. However, in reality, a wide range of different contaminants is often mixed in the aquatic environment (contaminant cocktail). Here, single and competitive sorption dynamics of ionizable norfloxacin (NOR), sulfamerazine (SMR) and oxytetracycline (OTC) by both pristine and modified biochars were investigated. Sorption kinetics of the three antibiotics was faster in ternary-solute than single-solute system. Sorption efficiency was enhanced in the competitive system for NOR by the pristine biochar, and for OTC by both the pristine biochar and the modified biochar, while SMR sorption by the pristine biochar and the KOH-modified biochar was inhibited. Sorption was governed by electrostatic interactions, π-π EDA and H-bonds for antibiotics sorption by biochar. SMR and OTC sorption by biochar was influenced by cation bridging and surface complexation, respectively. This research finding will guide the development of treatment procedures for water polluted by multiple antibiotics.
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.SCITOTENV.2019.134112
Abstract: The nature of biochar-derived dissolved organic matter (DOM) has a crucial role in the interactions between biochar and metal immobilization, carbon dynamics, and microbial communities in soil. This study utilized excitation-emission matrix coupled with parallel factor analysis (EEM-PARAFAC) modeling to provide mechanistic evidence of biochar-induced influences on main soil biogeochemical processes. Three biochars produced from rice straw, wood, and grass residues were added to sandy and sandy loam soils and incubated for 473 d. Microbial and terrestrial humic-like fluorescent components were identified in the soils after incubation. The sandy loam soil exhibited a higher DOM with microbial sources than did the sandy soil. All biochars reduced Pb bioavailability, whereas the rice straw biochar enhanced the As bioavailability in the sandy loam soil. The biochar-derived aliphatic-DOM positively correlated with As bioavailability (r = 0.82) in the sandy loam soil and enhanced the cumulative CO
Publisher: Elsevier BV
Date: 08-2022
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 08-2016
Publisher: Elsevier BV
Date: 07-2019
Publisher: Informa UK Limited
Date: 21-12-2014
DOI: 10.1080/09593330.2014.992481
Abstract: There is an increasing interest to recycle greywater for meeting non-portable water demand. However, linear alkylbenzene sulphonates (a form of anionic surfactants) that are commonly found in greywater are less biodegradable at moderate to high concentrations. A fenton-like system is a relatively economic advanced oxidation process that can potentially be used for surfactant degradation in greywater treatment. This study investigated the feasibility of zerovalent iron (ZVI)-mediated Fenton's oxidation of sodium dodecylbenzene sulphonate (SDBS) using Fe0/H2O2 and Fe2+/Fe0/H2O2 systems under a range of operating conditions. For the Fe0/H2O2 binary system, the initial pH value and Fe0 dosage played important roles in final degradation efficiency. For the Fe2+/Fe0/H2O2 ternary systems, a small amount of Fe2+ (0.5-1.7 mM) contributed a synergistic effect to promote iron recycling and SDBS degradation. Approximately, 90% of SDBS mineralization efficiency was accomplished within 15 min at a pH range from 3.0 to 6.5, using 18 mM Fe0 and 15 mM H2O2. However, the removal kinetics was rate-limited by Fe2+ dissolution from the ZVI surfaces. The Fenton-like process of the Fe2+/Fe0/H2O2 ternary system also presents a promising treatment method for synthetic greywater, in which 90% TOC removal was achieved within the first 10 min 78% COD and 91% BOD5 were achieved after 120 min of reaction.
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 07-2015
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.BIORTECH.2017.09.110
Abstract: This study aims to produce levulinic acid (LA) from paper towel waste in environment-friendly and economically feasible conditions, and evaluate the difference using solid and aqueous Brønsted acids. Direct dehydration of glucose to LA required sufficiently strong Brønsted acidity, where Amberlyst 36 demonstrated rapid production of approximately 30Cmol% of LA in 20min. However, the maximum yield of LA was limited by mass transfer. In contrast, the yield of LA gradually increased to over 40Cmol% in 1M H
Publisher: Springer Science and Business Media LLC
Date: 28-03-2023
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 08-2019
Publisher: American Chemical Society (ACS)
Date: 28-05-2020
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.07.046
Abstract: In this study, we evaluated the feasibility of using ferric salts including FeCl
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.SCITOTENV.2017.04.208
Abstract: This study evaluated the feasibility of 2-h chemical-enhanced washing of As-containing soil resulting from geogenic sources in Hong Kong and the fate of As before and after remediation. The soil morphology and As speciation in soil was elucidated by scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy. Integrated analysis of the results suggests that the As (>90%) resides predominantly as arsenate bound to ferric iron oxides, with a minor contribution (<10%) from an As
Publisher: Elsevier BV
Date: 12-2014
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.SCITOTENV.2019.134240
Abstract: Phosphorus (P) recovery from digestate has attracted considerable interest. In this study, hydrothermal processes in combination with struvite crystallization were performed to promote P solubilization and capture from digestate its potential as a phosphate-based fertilizer was also investigated. Hydrothermal treatment with HCl and H
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 06-2018
Publisher: Elsevier BV
Date: 2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0CY00376J
Abstract: A core–shell structured FeCo–N@N-doped carbon derived from biomass wastes (sugarcane and palm kernel shell) is facilely prepared by hydrothermal carbonization and NH 3 microwave ammoxidation methods.
Publisher: American Chemical Society (ACS)
Date: 18-10-2018
Publisher: Elsevier BV
Date: 06-2007
DOI: 10.1016/J.CHEMOSPHERE.2007.01.022
Abstract: Ethylenediaminetetraacetic acid (EDTA) was used as a reference chelating agent in column experiments to investigate the effectiveness of chelant-enhanced flushing of soils artificially contaminated under various conditions (low/high Cu loading, and aging). The associated soil dissolution issues were of particular concern. Dissolution of indigenous Fe/Al oxides, Ca carbonates and organic matter was monitored over the course of flushing. Regardless of contamination condition, above 85% extraction efficiency could be accomplished by 10(-2) and 10(-3)M EDTA-flushing, but not 10(-4)M. The Cu extraction kinetics positively correlated to EDTA concentration but inversely to Cu loading in soils. In addition to extraction from weakly sorbed fractions, a large portion of Cu was extracted from oxide, organic matter and residual fractions, which appears to derive from soil dissolution. Cumulative dissolved amounts of Fe, Al, and Ca were found to reach as high as hundreds of mgkg(-1), which were comparable to Cu contamination. Soil organic matter, which is known to strongly interact with Fe and Al oxides, was also mobilized. The rate and extent of these soil dissolutions were also positively correlated to EDTA concentration. Therefore, the co-extraction of soil minerals and organic matter during chelant-enhanced flushing, which would alter both physical structure and chemical properties of the soils, is detrimental to future land use and deserves greater attention. The concentration of chelating agent is the most crucial factor for an effective soil flushing with minimal damage.
Publisher: Elsevier BV
Date: 06-2019
Publisher: Elsevier BV
Date: 12-2021
DOI: 10.1016/J.BIORTECH.2021.126067
Abstract: Recent studies show that fast hydropyrolysis (i.e., pyrolysis under hydrogen atmosphere operating at a rapid heating rate) is a promising technology for the conversion of biomass into liquid fuels (e.g., bio-oil and C
Publisher: Elsevier BV
Date: 06-2018
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.CHEMOSPHERE.2019.03.170
Abstract: The beneficial role of biochar on improvement of soil quality, C sequestration, and enhancing crop yield is widely reported. As such there is not much consolidated information available linking biochar modulated soil condition improvement and soil nutrient availability on crop yields. The present review paper addresses the above issues by compilation of world literature on biochar and a new dimension is introduced in this review by performing a meta-analysis of published data by using multivariate statistical analysis. Hence this review is a new in its kind and is useful to the broad spectrum of readers. Generally, alkalinity in biochar increases with increase in pyrolysis temperature and majority of the biochar is alkaline in nature except a few which are acidic. The N content in many biochar was reported to be more than 4% as well as less than 0.5%. Poultry litter biochar is a rich source of P (3.12%) and K (7.40%), while paper mill sludge biochar is higher in Ca content (31.1%) and swine solids biochar in Zn (49810 mg kg
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.SCITOTENV.2019.135547
Abstract: As an element with well-known toxicity, excessive thallium (Tl) in farmland soils, may threaten food security and induce extreme risks to human health. Identification of key contamination sources is prerequisite for remediation technologies. This study aims to examine the contamination level, health risks and source apportionment of Tl in common vegetables from typical farmlands distributed over a densely populated residential area in a pyrite mine city, which has been exploiting Tl-bearing pyrite minerals over 50 years. Results showed excessive Tl levels were exhibited in most of the vegetables (0.16-20.33 mg/kg) and alarming health risks may induce from the vegetables via the food chain. Source apportionment of Tl contamination in vegetables was then evaluated by using Pb isotope fingerprinting technique. Both vegetables and soils were characterized with overall low
Publisher: Elsevier BV
Date: 05-2018
DOI: 10.1016/J.CHEMOSPHERE.2018.01.162
Abstract: Biochar effect on the potential mobility of dibutyl phthalate (DBP), cadmium (Cd), and lead (Pb) in co-contaminated soils is not well investigated. A laboratory leaching study was conducted to evaluate the effect of biochars derived from bamboo (BB) and pig (PB) on the leachability of DBP, Cd, and Pb through soil columns packed with two soils with low or high organic carbon content (LOC 0.35% C: HOC 2.24% C) and spiked with DBP, Cd, and Pb. Application of PB to the LOC soil significantly (P < 0.05) reduced the leaching loss by up to 88% for DBP, 38% for Cd, and 71% for Pb, whereas its impact was insignificant in the HOC soil. The higher efficacy of PB in reducing the leaching of DBP, Cd, and Pb in the LOC soil than that of BB might be related to PB's higher specific surface area, surface alkalinity, pH, and mineral contents compared to those of BB. Co-contamination of Cd and Pb enhanced leaching of DBP in the LOC soil treated with PB, possibly by competition for the sorption sites. Leaching of DBP, Cd, and Pb were significantly (P < 0.05) higher in the LOC soil than in the HOC soil. This study revealed that the effectiveness of biochars was dependent on the soil organic carbon content. Application of PB to the LOC soil was effective in reducing the leaching risk of DBP, Cd, and Pb.
Publisher: Informa UK Limited
Date: 02-07-2018
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.JHAZMAT.2019.01.112
Abstract: In this study, concrete slurry waste (CSW) and fine incineration bottom ash (IBA) (<2.36 mm) were innovatively valorized to produce cold bonded lightweight aggregates (CBLAs) through a pelletizing method. The contribution of CSW to CBLAs as a fresh recycled cementitious paste was investigated and the influences of adding various binders (OPC, GGBS, lime, silica fume) on the properties of CBLAs were explored. Meanwhile, the leaching behaviours of the produced CBLAs were further assessed. The experimental results showed that CSW and IBA had a good compatibility to produce CBLAs by the pelletizing method. The use of fresh and workable CSW collected from ready-mixed concrete plants as a recycled cementitious paste could effectively bond the IBA particles. Due to the residual hydration behaviour of CSW, the produced CBLAs, even without additional binders, had good mechanical properties. The use of small percentages of cement and GGBS as additional binders could significantly increase the strength of CBLAs, while the use of lime and silica fume only showed slight improvement due to the high porosity induced. Moreover, it was found that using GGBS which could react with Ca(OH)
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.JHAZMAT.2019.122005
Abstract: Solidification/Stabilization (S/S) is an effective way to immobilize toxic metals in contaminated soil. However, utilization of ordinary Portland cement (PC) in this process has raised environmental concerns owing to the high carbon footprint from PC manufacturing and the risk of toxic element leaching in the long term. Hence there is an urgent need to seek for "green" immobilization approaches with long-term stability. In this study, a clay-based material, humic acid modified montmorillonite (HA-Mont) was applied to a Cd and Hg contaminated soil. Field emission scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (FESEM/EDS), N
Publisher: Elsevier BV
Date: 06-2021
Publisher: Wiley
Date: 16-06-2021
DOI: 10.1111/SUM.12731
Abstract: Engineered biochars are promising candidates in a wide range of environmental applications, including soil fertility improvement, contaminant immobilization, wastewater treatment and in situ carbon sequestration. This review provides a systematic classification of these novel biochar composites and identifies the promising future trends in composite research and application. It is proposed that metals, minerals, layered double hydroxides, carbonaceous nanomaterials and microorganisms enhance the performances of biochars via distinct mechanisms. In this review, four novel trends are identified and assessed critically. Firstly, facile synthesis methods, in particular ball milling and co‐pyrolysis, have emerged as popular composite fabrication strategies that are suitable for large‐scale applications. Secondly, biochar modification with green materials, such as natural clay minerals and microorganisms, align well with the on‐going green and sustainable remediation (GSR) movement. Furthermore, new applications in soil health improvement and climate change mitigation support the realization of United Nation's Sustainable Development Goals (SDGs). Finally, the importance of field studies is getting more attention, since evidence of field success is critically needed before large‐scale applications.
Publisher: Elsevier BV
Date: 08-2023
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 2023
DOI: 10.1016/J.JHAZMAT.2022.129904
Abstract: As an important subtopic within phytoremediation, hyperaccumulators have garnered significant attention due to their ability of super-enriching heavy metals. Identifying the factors that affecting phytoextraction efficiency has important application value in guiding the efficient remediation of heavy metal contaminated soil. However, it is challenging to identify the critical factors that affect the phytoextraction of heavy metals in soil-hyperaccumulator ecosystems because the current projections on phytoremediation extrapolations are rudimentary at best using simple linear models. Here, machine learning (ML) approaches were used to predict the important factors that affecting phytoextraction efficiency of hyperaccumulators. ML analysis was based on 173 data points with consideration of soil properties, experimental conditions, plant families, low-molecular-weight organic acids from plants, plant genes, and heavy metal properties. Heavy metal properties, especially the metal ion radius, were the most important factors that affect heavy metal accumulation in shoots, and the plant family was the most important factor that affect the bioconcentration factor, metal extraction ratio, and remediation time. Furthermore, the Crassulaceae family had the highest potential as hyperaccumulators for phytoremediation, which was related to the expression of genes encoding heavy metal transporting ATPase (HMA), Metallothioneins (MTL), and natural resistance associated macrophage protein (NRAMP), and also the secretion of malate and threonine. New insights into the effects of plant characteristics, experimental conditions, soil characteristics, and heavy metal properties on phytoextraction efficiency from ML model interpretation could guide the efficient phytoremediation by identifying the best hyperaccumulators and resolving its efficient remediation mechanisms.
Publisher: American Chemical Society (ACS)
Date: 27-09-2006
DOI: 10.1021/ES060625I
Abstract: The competitive effect influenced the transport behavior of Cu and Cd contrastingly in soils, as illustrated by the experimental findings obtained from column, batch kinetics, and sequential extraction tests. Of particular interest, Cd transport behavior changed from nonequilibrium in a single-metal system to equilibrium in a binary-metal system, whereas Cu exhibited a slightly greater degree of nonequilibrium transport under competition. The equilibrium time of specific sorption (approximately 7 days) was found to be much longer than that of nonspecific sorption (approximately 30 min). While there was a competitive effect on nonspecific sorption for both Cu and Cd, the majority of rate-limited specific sorption of Cd on oxide and organic matter fractions (contributing to approximately 20% of total sorption) was dramatically displaced by Cu. Such a strong suppression of specific sorption of Cd bythe presence of Cu resulted in a shorter equilibrium time of overall sorption, which probably accounts for its equilibrium transport. In contrast, the competitive effect on rate-limited sorption and transport behavior of Cu was less significant. This study demonstrated a correlation between the competitive effect of Cu and Cd on their nonspecific and specific sorption and the corresponding significance of rate-limited sorption and nonequilibrium transport behavior.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 05-2018
Publisher: Elsevier BV
Date: 11-2019
Publisher: Springer Science and Business Media LLC
Date: 04-08-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0GC00717J
Abstract: Biochar-based carbocatalysis is synergized from electroactive components including reactive-active moieties, metals, defective sites, heteroatoms, and graphitic structure for sustainable remediation.
Publisher: American Chemical Society (ACS)
Date: 17-06-2020
Publisher: Informa UK Limited
Date: 12-2013
DOI: 10.1080/09593330.2013.808243
Abstract: This study aims to investigate a new and sustainable approach for the reuse of industrial by-products from wastewater treatment. The dairy industry produces huge volumes of wastewater, characterized by high levels of phosphate that can result in eutrophication and degradation of aquatic ecosystems. This study evaluated the application of acid mine drainage (AMD) sludge, coal fly ash, and lignite as low-cost adsorbents for the removal of phosphate from dairy wastewater. Material characterization using X-ray fluorescence, X-ray diffraction, and Brunauer-Emmett-Teller surface area analysis revealed significant amounts of crystalline/amorphous Fe/Al/Si/Ca-based minerals and large surface areas of AMD sludge and fly ash. Batch adsorption isotherms were best described using the Freundlich model. The Freundlich distribution coefficients were 13.7 mg(0.577) L(0.423) g(-1) and 16.9 mg(0.478) L(0.522) g(-1) for AMD sludge and fly ash, respectively, and the nonlinearity constants suggested favourable adsorption for column applications. The breakthrough curves of fixed-bed columns, containing greater than 10 wt% of the waste materials (in idual or composite blends) mixed with sand, indicated that phosphate breakthrough did not occur within 100 pore volumes while the cumulative removal was 522 and 490 mg kg(-1) at 10 wt% AMD sludge and 10 wt% fly ash, respectively. By contrast, lignite exhibited negligible phosphate adsorption, possibly due to small amounts of inorganic minerals suitable for phosphate complexation and limited surface area. The results suggest that both AMD sludge and fly ash were potentially effective adsorbents if employed in idually at a ratio of 10 wt% or above for column application.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.SCITOTENV.2021.151124
Abstract: The science-informed design of stable carbonaceous materials as 'green' soil amendment will be indispensable for improving the soil fertility and carbon sequestration ability. In this study, a series of biochars were prepared from mineral-rich cellulosic corn straw (C), lignocellulosic pine wood (P), and lignin-rich walnut shell (W) at 500 or 700 °C. Their change of carbon stability after 90-day interaction with two typical soil clay minerals (i.e., kaolinite or montmorillonite) under a field-relevant condition (mass ratio of biochar to soil clay at 1:5) was evaluated as carbon loss (%) determined by the K
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 06-2023
Publisher: Springer Science and Business Media LLC
Date: 16-12-2016
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 2021
Publisher: American Chemical Society (ACS)
Date: 28-11-2016
DOI: 10.1021/ACS.ACCOUNTS.6B00460
Abstract: The future advances of supercapacitors depend on the development of novel carbon materials with optimized porous structures, high surface area, high conductivity, and high electrochemical stability. Traditionally, nanoporous carbons (NPCs) have been prepared by a variety of methods, such as templated synthesis, carbonization of polymer precursors, physical and chemical activation, etc. Inorganic solid materials such as mesoporous silica and zeolites have been successfully utilized as templates to prepare NPCs. However, the hard-templating methods typically involve several synthetic steps, such as preparation of the original templates, formation of carbon frameworks, and removal of the original templates. Therefore, these methods are not favorable for large-scale production. Metal-organic frameworks (MOFs) with high surface areas and large pore volumes have been studied over the years, and recently, enormous efforts have been made to utilize MOFs for electrochemical applications. However, their low conductivity and poor stability still present major challenges toward their practical applications in supercapacitors. MOFs can be used as precursors for the preparation of NPCs with high porosity. Their parent MOFs can be prepared with endless combinations of organic and inorganic constituents by simple coordination chemistry, and it is possible to control their porous architectures, pore volumes, surface areas, etc. These unique properties of MOF-derived NPCs make them highly attractive for many technological applications. Compared with carbonaceous materials prepared using conventional precursors, MOF-derived carbons have significant advantages in terms of a simple synthesis with inherent ersity affording precise control over porous architectures, pore volumes, and surface areas. In this Account, we will summarize our recent research developments on the preparation of three-dimensional (3-D) MOF-derived carbons for supercapacitor applications. This Account will be ided into three main sections: (1) useful background on carbon materials for supercapacitor applications, (2) the importance of MOF-derived carbons, and (3) potential future developments of MOF-derived carbons for supercapacitors. This Account focuses mostly on carbons derived from two types of MOFs, namely, zeolite imidazolate framework-8 (ZIF-8) and ZIF-67. By using ex les from our previous works, we will show the uniqueness of these carbons for achieving high performance by control of the chemical reactions/conditions as well proper utilization in asymmetric/symmetric supercapacitor configurations. This Account will promote further developments of MOF-derived multifunctional carbon materials with controlled porous architectures for optimization of their electrochemical performance toward supercapacitor applications.
Publisher: Elsevier BV
Date: 05-2018
DOI: 10.1016/J.CHEMOSPHERE.2018.02.074
Abstract: During the measurement of total organic carbon (TOC), dissolved organic carbon is converted into CO
Publisher: Elsevier BV
Date: 07-2022
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.SCITOTENV.2018.08.075
Abstract: Emissions of polycyclic aromatic hydrocarbons (PAHs) in China remain at a high level compared to those in developed countries. The Yangtze River Delta (YRD) is an economic and industrial center in China with an extremely large population. The potentially high emissions and excess cancer risk from human exposure in this region cannot be neglected. This study applied a multimedia model to estimate the concentrations of 16 US EPA priority PAHs in the environment in the YRD with a well-developed PAH-emission inventory for 2014. The model predicted that the average concentrations of ΣPAHs were 274 ng/m Multimedia modeling predicted distributions and compositions of PAHs in different environmental compartments, and deterministic and probabilistic ELCRs induced by air inhalation and soil ingestion were also provided.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0GC02644A
Abstract: Superheating of starch substrates in microwaves helps to actualize a green, energy-efficient biorefinery of food wastes.
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 2021
Publisher: American Chemical Society (ACS)
Date: 17-06-2021
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.ENVPOL.2019.02.092
Abstract: Thallium (Tl) is a trace metal of severe toxicity. Its health concerns via consumption of contaminated vegetables have often been overlooked or underestimated. This study was designed to gain insight into the actual level and distribution characteristics of Tl and metal (loid)s (Pb, Cd, Cr, Sb, Mn, Cu, Zn, Ni, and Co) in agricultural soils and common vegetables cultivated in different zones (upstream, midstream, and downstream) of a densely populated residential area in a typical mine city, which has been open-pit exploiting Tl-bearing pyrite minerals since 1960s. The results show that most of the agricultural soils exhibit contaminated levels of Tl, with Tl contents (upstream: 1.35-4.31 mg/kg, midstream: 2.43-5.19 mg/kg, and downstream: 0.65-2.33 mg/kg) mostly exceeding the maximum permissible level (MPL) for agricultural land use (1 mg/kg). Sequential extraction procedure indicates that even Tl is predominantly retained in the residual fraction, significant levels of Tl are still present in the geochemically mobile fractions. Besides, metals like Cu, Cd, Mn, and Co are mostly distributed in the labile fractions. Almost all metal (loid)s in edible parts of the vegetables exceed their corresponding MPL for consumption. The chronic daily intake (CDI) and hazard quotient (HQ) values calculated for inhabitants at different ages indicate non-negligible Tl risks via consumption of local vegetables, especially for children. Therefore, it is critical to establish effective measures for hazardous waste management and enforceable regulations in Tl-polluted area to mitigate potential severe impacts of Tl on human health through food chain.
Publisher: Wiley
Date: 05-02-2023
Abstract: In the recycling of retired lithium‐ion batteries (LIBs), the cathode materials containing valuable metals should be first separated from the current collector aluminum foil to decrease the difficulty and complexity in the subsequent metal extraction. However, strong the binding force of organic binder polyvinylidene fluoride (PVDF) prevents effective separation of cathode materials and Al foil, thus affecting metal recycling. This paper reviews the composition, property, function, and binding mechanism of PVDF, and elaborates on the separation technologies of cathode material and Al foil (e.g., physical separation, solid‐phase thermochemistry, solution chemistry, and solvent chemistry) as well as the corresponding reaction behavior and transformation mechanisms of PVDF. Due to the characteristic variation of the reaction systems, the dissolution, swelling, melting, and degradation processes and mechanisms of PVDF exhibit considerable differences, posing new challenges to efficient recycling of spent LIBs worldwide. It is critical to separate cathode materials and Al foil and recycle PVDF to reduce environmental risks from the recovery of retired LIBs resources. Developing fluorine‐free alternative materials and solid‐state electrolytes is a potential way to mitigate PVDF pollution in the recycling of spent LIBs in the EV era.
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.ENVPOL.2019.113032
Abstract: Although, health and environmental hazards of Ni are ironclad however, that of Nickle oxide nanoparticles (NiO-NPs) are still obscure. Therefore, impact of NiO-NPs exposure (0, 5, 50, 200, 500 and 1000 mg kg
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.BIORTECH.2021.126395
Abstract: Hydrothermal carbonization (HTC) provides a promising alternative to valorize food waste digestate (FWD) and avoid disposal issues. Although hydrochar derived from FWD alone had a low calorific content (HHV of 13.9 MJ kg
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.CHEMOSPHERE.2016.06.030
Abstract: While chelant-enhanced soil washing has been widely studied for metal extraction from contaminated soils, there are concerns about destabilization and leaching of residual metals after remediation. This study integrated 2-h soil washing enhanced by biodegradable ethylenediaminedisuccinic acid (EDDS) and 2-month stabilization using agricultural waste product (soybean stover biochar pyrolyzed at 300 and 700 °C), industrial by-product (coal fly ash (CFA)), and their mixture. After integration with 2-month stabilization, the leachability and mobility of residual metals (Cu, Zn, and Pb) in the field-contaminated soil were significantly reduced, especially for Cu, in comparison with 2-h EDDS washing alone. This suggested that the metals destabilized by EDDS-washing could be immobilized by subsequent stabilization with biochar and CFA. Moreover, when the remediation performance was evaluated for phytoavailability and bioaccessibility, prior EDDS washing helped to achieve a greater reduction in the bioavailable fraction of metals than sole stabilization treatment. This was probably because the weakly-bound metals were first removed by EDDS washing before stabilization. Both in idual and combined applications of biochar and CFA showed comparable effectiveness regardless of the difference in material properties, possibly due to the high level of amendments (150 ton ha(-1)). Based on the mobility and bioaccessibility results, the estimated human health risk (primarily resulting from Pb) could be mitigated to an acceptable level in water consumption pathway or reduced by half in soil ingestion pathway. These results suggest that an integration of EDDS washing with soil stabilization can alleviate post-remediation impacts of residual metals in the treated soil.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.CHEMOSPHERE.2018.02.085
Abstract: Utilization of bacterial volatilization can be problematic to remediate mercury (Hg)-contaminated soils because most of the Hg in soils is bound to soil particles. The objective of this study was to develop a two-stage system (chemical extraction followed by microbial reduction) for Hg-contaminated soil remediation. The tasks were to (1) select the extraction reagents for Hg extraction, (2) assess the effects of extraction reagents on the growth of Hg-reducing bacterial strains, and (3) evaluate the effectiveness of Ca
Publisher: Elsevier BV
Date: 05-2020
Publisher: Springer Science and Business Media LLC
Date: 24-08-2018
DOI: 10.1007/S10653-018-0174-0
Abstract: The retention of radioactive cesium (Cs) in soil is significantly related to the types of clay minerals, while the weathering process affects the irreversible adsorption sites in clay minerals. In this study, the effect of weathering (exposure duration of Cs and repeated wetting and drying cycles) on fractionation of Cs in soils was investigated using fractionation analysis by the sequential extraction. The residual fraction of Cs increased slowly with exposure time but increased rapidly by repeated wetting and drying cycles. XRD analysis shows that a 1.43 nm of interlayer size for vermiculite is shortened to 1.00 nm, i.e., similar to that of illite. The change implies the potential that the structure of expandable clay minerals is transformed to the non-expandable structure by weathering process after Cs retention. Based on the result, the residual fraction of Cs, most stable form of Cs in the soil, reached relatively rapidly to a maximum. However, the process is much slower kinetically in the field because the bench-scale weathering process used in this study is more aggressive. This study implies that Cs fractionations in the soil are converted into a more stable fraction by weathering processes in the soil. Therefore, Cs removal should be conducted as soon as possible after accidental release of Cs in an environmental side.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 08-2021
Publisher: Springer Science and Business Media LLC
Date: 19-07-2016
DOI: 10.1007/S10653-016-9853-X
Abstract: Atrazine is one of the most widely applied and persistent herbicides in the world. In view of limited information on the regional contamination of atrazine in soils in China, this study investigated the spatial distribution and environmental impacts of atrazine in agricultural soils collected from the Yangtze River Delta (YRD) as an illustrative analysis of rapidly developing regions in the country. The results showed that the concentrations of atrazine in the YRD agricultural soils ranged from <1.0 to 113 ng/g dry weight, with a mean of 5.7 ng/g, and a detection rate of 57.7 % in soils. Pesticide factory might be a major source for the elevated levels of atrazine in Zhejiang Province. The contamination of atrazine was closely associated with land use types. The concentrations and detection rates of atrazine were higher in corn fields and mulberry fields than in rice paddy fields. There was no significant difference in compositions of soil microbial phospholipids fatty acids among the areas with different atrazine levels. Positive relationship (R = 0.417, p < 0.05, n = 30) was observed between atrazine and total microbial biomass. However, other factors, such as soil type and land management practice, might have stronger influences on soil microbial communities. Human health risks via exposure to atrazine in soils were estimated according to the methods recommended by the US EPA. Atrazine by itself in all the soil s les imposed very low carcinogenic risks (<10
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.ENVPOL.2019.02.089
Abstract: Thallium (Tl) is a well-recognized hazardous heavy metal with very high toxicity. It is usually concentrated in sulfide minerals, such as pyrite (FeS
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.ENVRES.2018.10.002
Abstract: The presence of odorants/volatiles in the air exerted various types of negative impacts on the surrounding environment. Their concentrations in indoor/outdoor air, if exceeding the threshold level, may not only affect human health but also deteriorate living standards. To maintain and enhance the quality of life, a better tool for the removal of these molecules is in great demand. Metal-organic frameworks (MOFs) and their associated materials offer an excellent platform for the treatment of odorants/volatiles in air (and water) systems. The ersity of ligands and metal ions in their frame imparts large loading capacities and excellent selectivity for a variety of targetable VOCs and/or odorants. This review discusses the use of MOFs and their composites to treat odorants/volatile molecules in gaseous media, with extensive discussion of their adsorptive uptakes, along with methods for their synthesis and regeneration. Moreover, the progression of odorant/volatile removal by MOFs is considered, with a special note on future directions in this emerging research field.
Publisher: Wiley
Date: 17-03-2020
Publisher: Informa UK Limited
Date: 12-09-2020
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JHAZMAT.2019.121286
Abstract: Adsorbents that effectively remove dye substances from industrial effluents are needed for the protection of human health and the natural environment. However, adsorbent manufacture is associated with secondary environmental impacts. In this study, a green biochar/iron oxide composite was produced using a facile approach involving banana peel extract and FeSO
Publisher: Elsevier BV
Date: 12-2017
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.SCITOTENV.2019.135414
Abstract: Efficient conversion of food waste to value-added products necessitates the development of high-performance heterogeneous catalysts. This study evaluated the use of Al
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.ENVPOL.2019.01.047
Abstract: This study introduced a new approach for simultaneously enhancing Cr(VI) removal performance and mitigating release of dissolved Fe during nanoscale zero-valent iron (nZVI)-mediated reactions. After entrapping nZVI-impregnated biochar (BC) in the matrix of calcium-alginate (CA) bead, the physicochemical characterization of nZVI/BC/CA composites revealed that nZVI/BC particles were embedded inside CA having a spherical shape and several cracks on its outer layer. The multi-functionality of nZVI/BC/CA composites consisting of reductant (nZVI), porous adsorbent (BC), and external screening layer (CA) enhanced the removal of Cr(VI) with the maximum adsorption capacity of 86.4 mg/g (based on the Langmuir isotherm) and little release of dissolved Fe. With the XPS analysis and fitting results of kinetics (pseudo second order) and isotherms (Redlich-Peterson model), plausible removal mechanisms of Cr(VI) were simultaneous adsorption and micro-electrolysis reactions by nZVI/BC/CA composites. The practical applicability of nZVI/BC/CA composites was further demonstrated through the fixed-bed column experiments. These results provide new insights into the design of high-performance engineered biochar for wastewater treatment.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.SCITOTENV.2017.07.165
Abstract: Arsenic contamination in sediments has received increasing attention because it may be released to the water and threaten aquatic organisms. In this study, aluminum sulfate (ALS) was used to immobilize As in sediments through dosage-series and time-series experiments. Diffusive gradients in thin films (DGT) was used to obtain labile As at a vertically 2.0mm resolution. Our results indicated that a "static" layer with extremely low labile As concentration (minimally 0.13mgL
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.SCITOTENV.2018.02.185
Abstract: Previous studies indicated that using CO
Publisher: American Chemical Society (ACS)
Date: 25-09-2019
Publisher: Elsevier BV
Date: 07-2022
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 04-2021
Publisher: Springer Science and Business Media LLC
Date: 03-2016
DOI: 10.1007/S10653-016-9808-2
Abstract: Permeable reactive barriers (PRBs) have proved to be a promising passive treatment to control groundwater contamination and associated human health risks. This study explored the potential use of low-cost adsorbents as PRBs media and assessed their longevity and risk mitigation against leaching of acidic rainfall through an e-waste recycling site, of which Cu, Zn, and Pb were the major contaminants. Batch adsorption experiments suggested a higher adsorption capacity of inorganic industrial by-products [acid mine drainage sludge (AMDS) and coal fly ash (CFA)] and carbonaceous recycled products [food waste compost (FWC) and wood-derived biochar] compared to natural inorganic minerals (limestone and apatite). Continuous leaching tests of sand columns with 10 wt% low-cost adsorbents were then conducted to mimic the field situation of acidic rainfall infiltration through e-waste-contaminated soils (collected from Qingyuan, China) by using synthetic precipitation leaching procedure (SPLP) solution. In general, Zn leached out first, followed by Cu, and finally delayed breakthrough of Pb. In the worst-case scenario (e.g., at initial concentrations equal to 50-fold of average SPLP result), the columns with limestone, apatite, AMDS, or biochar were effective for a relatively short period of about 20-40 pore volumes of leaching, after which Cu breakthrough caused non-cancer risk concern and later-stage Pb leaching considerably increased both non-cancer and lifetime cancer risk associated with portable use of contaminated water. In contrast, the columns with CFA or FWC successfully mitigated overall risks to an acceptable level for a prolonged period of 100-200 pore volumes. Therefore, with proper selection of low-cost adsorbents (or their mixture), waste-based PRBs is a technically feasible and economically viable solution to mitigate human health risk due to contaminated groundwater at e-waste recycling sites.
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.ENVRES.2019.01.051
Abstract: Bacterial species for metabolizing dye molecules were isolated from dye rich water bodies. The best microbial species for such an application was selected amongst the isolated bacterial populations by conducting methylene blue (MB) batch degradation studies with the bacterial strains using NaCl-yeast as a nutrient medium. The most suitable bacterial species was Alcaligenes faecalis (A. faecalis) according to 16S rDNA sequencing. Process parameters were optimized and under the optimum conditions (e.g., inoculum size of 3 mL, temperature of 30 °C, 150 ppm, and time of 5 days), 96.2% of MB was removed. Furthermore, the effectiveness for the separation of MB combining bio-film with biochar was measured by a bio-sorption method in a packed bed bioreactor (PBBR) in which microbes was immobilized. The maximum MB removal efficiencies, when tested with 50 ppm dye using batch reactors containing free A. faecalis cells and the same cells immobilized on the biochar surface, were found to be 81.5% and 89.1%, respectively. The PBBR operated in continuous recycle mode at high dye concentration of 500 ppm provided 87.0% removal of MB through second-order kinetics over 10 days. The % removal was found in the order of PBBR>Immobilized batch>Free cell. The standalone biochar batch adsorption of MB can be described well by the pseudo-second order kinetics (R
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.09.040
Abstract: This study focused on the occurrence and spatial distribution of 13 common antibiotics in the agricultural soils of the Yangtze River Delta (YRD), China. Antibiotics were detected in all the 241 soil s les (i.e., 100% detection rate) with the total concentrations ranging from 4.55 to 2,010 ng/g dry weight. The concentrations of three antibiotic classes decreased in the order: quinolones (mean 48.8 ng/g) > tetracyclines (mean 34.9 ng/g) > sulfonamides (mean 2.35 ng/g). Ciprofloxacin was the prevalent compound with a mean concentration of 27.7 ng/g, followed by oxytetracycline (mean of 18.9 ng/g). A distinct spatial distribution was observed, where high concentrations of antibiotics were detected in the sites adjacent to the livestock and poultry farms. The potential sources of antibiotics in the agricultural soils were the application of manure and wastewater irrigation in this region. Risk assessment for single antibiotic compound indicated that tetracyclines and quinolones could pose a potential risk, in which doxycycline and ciprofloxacin had the most severe ecological effect in the agricultural soils. Antibiotic resistance genes (ARGs), such as tetA, sulI, and qnrS, were detected in 15 analyzed soil s les, and sulI showed significant correlations with quinolones, tetracyclines, copper, and zinc. Further studies on the distribution of other ARGs in agricultural soil at a region-scale are needed for the risk management of extensively used antibiotics and major ARGs.
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.SCITOTENV.2017.10.227
Abstract: The effectiveness of sediment dredging for the control of internal phosphorus (P) loading, was investigated seasonally in the eutrophic Lake Taihu. The high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) techniques were used to measure the concentrations of soluble Fe(II) and soluble reactive P (SRP) as well as DGT-labile Fe/P in the non-dredging and post-dredging sediments. The P resupply kinetics from sediment solids were interpreted using DGT Induced Fluxes in Sediments (DIFS) modeling. The results showed no obvious improvement in water and sediment quality after dredging for 6years, due to their geographical proximity (a line distance of approximately 9km). However, dredging significantly decreased the concentrations of soluble Fe(II)/SRP and DGT-labile Fe/P in sediments, with effects varying at different depths below the sediment-water interface More pronounced effects appeared in January and April. The diffusive flux of pore water SRP from sediments decreased from 0.746, 4.08 and 0.353mg/m
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2007
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JHAZMAT.2018.12.008
Abstract: Co-pyrolysis of lipid waste and red mud was investigated to achieve valorization of red mud by fabricating biochar composite. For the further sustainable approach, this study intentionally employed carbon dioxide (CO
Publisher: American Chemical Society (ACS)
Date: 02-04-2020
Publisher: American Chemical Society (ACS)
Date: 09-02-2008
DOI: 10.1021/ES072059C
Abstract: In zerovalent iron treatment systems, the presence of multiple solution components may impose combined effects that differ from corresponding in idual effects. The copresence of humic acid and hardness (Ca2+/Mg2+) was found to influence Cr(VI) reduction by Feo and iron dissolution in a way different from their respective presence in batch kinetics experiments with synthetic groundwater at initial pH 6 and 9.5. Cr(VI) reduction rate constants (k(obs)) were slightly inhibited by humic acid adsorption on iron filings (decreases of 7-9% and 10-12% in the presence of humic acid alone and together with hardness, respectively). The total amount of dissolved Fe steadily increased to 25 mg L(-1) in the presence of humic acid alone because the formation of soluble Fe-humate complexes appeared to suppress iron precipitation. Substantial amounts of soluble and colloidal Fe-humate complexes in groundwater may arouse aesthetic and safety concerns in groundwater use. In contrast, the coexistence of humic acid and Ca2+/Mg2+ significantly promoted aggregation of humic acid and metal hydrolyzed species, as indicated by XPS and TEM analyses, which remained nondissolved (>0.45 microm) in solution. These metal-humate aggregates may impose long-term impacts on PRBs in subsurface settings.
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.ENVPOL.2018.08.044
Abstract: Sediments nearby harbors are dredged regularly, and the sediments require the stringent treatment to meet the regulations on reuse and mitigate the environmental burdens from toxic pollutants. In this study, FeCl
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 04-2011
DOI: 10.1016/J.CHEMOSPHERE.2010.12.056
Abstract: Phenanthrene is commonly present together with heavy metals at many contaminated sites. This study investigated the influence of coexisting lead (Pb(2+)) or cadmium (Cd(2+)) on phenanthrene adsorption on soils. Batch experiments were conducted under different geochemical conditions including pH, mineral structure, organic matter content, and varying amounts of heavy metals. The results showed that the presence of heavy metals in solution at a fixed pH of 5.8±0.1 enhanced phenanthrene adsorption, the extent of which was closely related to the concentrations and the electro-negativity of the metals. The enhancement on phenanthrene adsorption was positively correlated to the amount of adsorbed metals. Although Cd(2+) is a softer Lewis acid, Pb(2+) displayed a more significant effect as it was adsorbed to a greater extent on the soil surfaces. Thus, density of cation accumulation appears to be more influential than metal softness in enhancing phenanthrene adsorption. Moreover, with a portion of organic matter removed by heating at 550°C, there was a stronger enhancement of phenanthrene adsorption by coexisting Pb(2+), indicating an increasingly dominant mechanisms associated with Pb(2+) at a lower organic matter content. Similar enhancement phenomenon was observed on bentonite and kaolinite, probably resulting from the cation-π bonding between the adsorbed soft metal cations and the aromatic ring of phenanthrene in solution. The desorption experiments further suggested that the bonding of phenanthrene adsorption was strengthened in the presence of Pb(2+) and that a larger proportion of adsorbed phenanthrene remained on the soils (residual fraction) even after sequential methanol extractions. Further spectroscopic analyses and surface characterization are required to provide direct evidence of the formation and relative significance of cation-π bond for phenanthrene adsorption.
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.SCITOTENV.2017.11.023
Abstract: Climate change gives rise to rapid degradation of rural soils in sloping subtropical and tropical areas and might further threaten environmental sustainability. In this study, we conducted an integrated evaluation of the effects of wood biochar (WB) application mixed with a green waste dreg compost (GWC) on runoff quality, soil losses, and agricultural productivity for a highly weathered tropical soil. A conventional agriculture method, in which soils are treated with anionic polyacrylamide (PAM), was also conducted for comparison. The amounts of runoff and soil loss, and nutrient retention were evaluated a year after WB application. Soil fertility was also investigated through a year pot experiment with rape (Brassica c estris L.) cultivation. Our results showed that the WB application not only effectively increased soil pH, soil organic carbon (SOC) and exchangeable K
Publisher: Elsevier BV
Date: 10-2021
Publisher: Springer Science and Business Media LLC
Date: 17-03-2013
Publisher: Elsevier BV
Date: 03-2019
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.BIORTECH.2018.07.048
Abstract: The catalytic activity of engineered biochar was scrutinized for generation of glucose and hydroxymethylfurfural (HMF) from starch-rich food waste (bread, rice, and spaghetti). The biochar catalysts were synthesized by chemical activation of pinewood sawdust with phosphoric acid at 400-600 °C. Higher activation temperatures enhanced the development of porosity and acidity (characterized by COPO
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 10-2016
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 04-2019
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JHAZMAT.2018.12.011
Abstract: As formaldehyde (FA) is well-known for its carcinogenic potential, various techniques for its removal have been developed based on recovery (e.g., adsorption/absorption and condensation) or destructive treatment (e.g., incineration and thermal/ catalytic oxidation). Among them, adsorption has been one of the most preferable options due to its low price and simplicity. In this review, we summarize state-of-the-art knowledge about adsorption mechanisms with respect to its key controlling variables (e.g., surface chemical properties of adsorbent, temperature, and relative humidity) and adsorption performance of materials with particular emphasis on advanced materials (e.g., carbon nanotubes, metal-organic frameworks, graphene oxides, and porous organic polymers) and their modified forms in comparison with conventional sorbents (e.g., AC and zeolite). However, it is yet difficult to assess the adsorption capacity of each material on a parallel basis because adsorption experiments of each material were conducted under different conditions (e.g., large differences in the initial loading concentrations). The partition coefficient (PC) was employed for evaluating adsorption performance between different materials at an equivalent level to overcome the limitation based on adsorption capacity concept. For instance, among the list of the surveyed materials, the highest PC was recorded by γ-CD-MOF-K (31.2 mol kg
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.SCITOTENV.2022.153768
Abstract: Incinerated sewage sludge ash is tested here as a cement and aggregate substitute in mortar blocks. It can be used at various percentages to reduce the overall cost of production and promote ash recycling. The compressive strength of the cast blocks was tested at 28 days to determine the optimal combination of ball milled ash (replacing cement) and sewage sludge ash (replacing sand). This was compared with a control block made of cement and sand only. The cast blocks with the optimal ash formulation were tested for their flexural strength and other properties such as surface functional groups, constituent phases and porosity. The control and ash mortars exhibited similar properties. A potential application of these blocks is to use them as part of seawalls. These blocks were thus suspended in the sea for 6 months. Marine organism attachment was observed over time in both control and ash mortar blocks. There was no significant difference between the mortars after 6 months. The mortar blocks were also subjected to leaching tests (NEN-7345). The leachates did not exhibit toxicity to microalgae. In contrast, mild toxicity was observed in the sea urchin embryo development assay. Overall, the study suggests that sewage sludge ash is a potential material to be used for seawall construction as it has the desirable mechanical properties. However, there remain some residual marine toxicity concerns that need to be further addressed.
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.SCITOTENV.2017.11.132
Abstract: Polluted land is a global issue, especially for developing countries. It has been reported that soil amendment with biochar may reduce the bioavailability of a wide range of contaminants, including heavy metal(loids), potentially reclaiming contaminated soils for agricultural use. However, there have been only limited reports on the in situ application of biochar at the field scale. This review was devoted to providing preliminary scientific evidence from these field trials, based on a review of 29 publications involving field applications of biochar in 8 different countries. The data show that biochar's effectiveness in reducing the impacts of pollution depends on a myriad of factors in the field, including the application time period, site-specific factors (e.g. climate, biochar dosage rate, and mixing depth), biochar feedstock type, and biochar properties. The results of this review indicate that biochar application can potentially reduce contaminant bioavailability in the field for instance, a significant decrease (control normalized mean value=0.55) in the Cd enrichment of rice crops was observed. It was found that the use of biochar may help increase crop yields on polluted land, and thus reduce the amount of mineral fertilizer used in the field. However, in order to maximize the benefits of biochar addition, farmers need to accept that the dosage rates of mineral fertilizers should be reduced. This review also revealed that the effectiveness of biochar in mitigating pollution may decrease with time due to ageing factors, such as leaching of biochar alkalinity.
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.ENVINT.2019.105046
Abstract: Soil contamination by potentially toxic elements (PTEs) has led to adverse environmental impacts. In this review, we discussed remediation of PTEs contaminated soils through immobilization techniques using different soil amendments with respect to type of element, soil, and amendment, immobilization efficiency, underlying mechanisms, and field applicability. Soil amendments such as manure, compost, biochar, clay minerals, phosphate compounds, coal fly ash, and liming materials are widely used as immobilizing agents for PTEs. Among these soil amendments, biochar has attracted increased interest over the past few years because of its promising surface properties. Integrated application of appropriate amendments is also recommended to maximize their use efficiency. These amendments can reduce PTE bioavailability in soils through erse mechanisms such as precipitation, complexation, redox reactions, ion exchange, and electrostatic interaction. However, soil properties such as soil pH, and clay, sesquioxides and organic matter content, and processes, such as sorption/desorption and redox processes, are the key factors governing the amendments' efficacy for PTEs immobilization in soils. Selecting proper immobilizing agents can yield cost-effective remediation techniques and fulfill green and sustainable remediation principles. Furthermore, long-term stability of immobilized PTE compounds and the environmental impacts and cost effectiveness of the amendments should be considered before application.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 09-2018
Publisher: Springer Science and Business Media LLC
Date: 21-06-2022
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.SCITOTENV.2020.136721
Abstract: Considering the high Zn content of municipal sewage sludge and its competition with Cd during plant uptake due to their similar properties, the presence of Zn in sludge-derived biochar (SDBC) may affect Cd immobilization and uptake by plants. To confirm this, SDBC s les with different Zn contents were prepared and characterized. Their Cd immobilization behavior was studied by conducting batch sorption experiments, and their effects on Cd uptake by lettuce were explored by conducting hydroponic experiments. The results reveal that some Zn contained in the sewage sludge was transformed into ZnO during pyrolysis. The Brunauer-Emmett-Teller (BET) surface area of the SDBC s les containing 2324 mg kg
Publisher: Elsevier BV
Date: 05-2018
DOI: 10.1016/J.JHAZMAT.2018.01.045
Abstract: The bioavailable PAHs (freely dissolved concentration, Cfree) were determined in sewage sludge (SL) or sewage sludge and biochar (BC) amended soil. SL or SL with a 2.5, 5 or 10% of BC was applied to the soil. The study was conducted as a long-term field experiment. Addition of BC to SL at a dose of 2.5 and 5% did not affect the content of Cfree PAHs in soils. However a significant difference (by 13%) in Cfree PAHs content was noted in experiment with 10% addition of BC. During the experiment, the concentration of Cfree PAHs in SL- and SL/BC-amended soil decreased. In particular s ling terms the content of Cfree PAHs in SL/BC-amended soil was significantly lower comparing to the Cfree PAHs content in SL-amended soil. After 18 months, Cfree PAH content was significantly lower in SL/BC-amended soil than in the experiment with SL alone, and did not differ significantly from the Σ16 Cfree content in the control soil. The largest decrease relative to the soil with sewage sludge alone was observed for 3-, 5- and 6-ring PAHs. This is the first field-based evidence that biochar soil amendment was effective to reduce of the Cfree of PAHs in sewage sludge-amended soils.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9SE00681H
Abstract: We describe the selective hydrogenation of furfural (FAL) into tetrahydrofurfuryl alcohol (THFA) under mild conditions (30 °C) in aqueous media using a Rh-loaded carbon (Rh/C) catalyst in a one-pot fashion.
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.08.012
Abstract: Chemical extraction of incinerated sewage sludge ash (ISSA) can effectively recycle P, but it may change the speciation and mobility of the remaining metals. This study investigated the changes of the leaching potential and distribution of metals in the chemically extracted ISSA. Batch extraction experiments with different extractants, including inorganic acids, organic acids, and chelating agents, were conducted on the ISSA collected from a local sewage sludge incinerator. The extraction of Zn, Cu, Pb, Ni, Cd, Ba, Cr and As from the ISSA and the corresponding changes of the mobility and speciation were examined. The results showed that the metals in ISSA were naturally stable because large portions of metals were associated with the residual fraction. The inorganic (HNO
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 03-2019
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.SCITOTENV.2018.01.037
Abstract: Low impact development (LID) systems are increasingly used to manage stormwater, but they have limited capacity to treat stormwater-a resource to supplement existing water supply in water-stressed urban areas. To enhance their pollutant removal capacity, infiltration-based LID systems can be augmented with natural or engineered geomedia that meet the following criteria: they should be economical, readily available, and have capacity to remove a wide range of stormwater pollutants in conditions expected during intermittent infiltration of stormwater. Biochar, a carbonaceous porous co-product of waste biomass pyrolysis/gasification, meets all these criteria. Biochar can adsorb pollutants, improve water-retention capacity of soil, retain and slowly release nutrients for plant uptake, and help sustain microbiota in soil and plants atop all these attributes could help improve removal of contaminants in stormwater treatment systems. This article discusses contaminant removal mechanisms by biochar, summarizes specific biochar properties that enhance targeted contaminants removal from stormwater, and identifies challenges and opportunities to retrofit biochar in LID to optimize stormwater treatment.
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.CHEMOSPHERE.2019.124775
Abstract: Enriched levels of thallium (Tl) in the environment are not only derived from anthropogenic sources but also have potential natural origins owing to Tl-rich sulphide mineralization. However, little is known regarding the geochemical fractionations of Tl in contaminated soils from geogenic sources. This study aims to reveal the Tl geochemical fractionations in different types of soils from a large-scale independent Tl mine in southwestern China, via a modified Institute for Reference Materials and Measurement (IRMM) sequential extraction (four-step) scheme. The results revealed that a large percentage of Tl was related to the labile portions (including reducible, weak-acid-exchangeable, and oxidizable fraction) of the soils (68.8-367 mg kg
Publisher: Elsevier BV
Date: 04-2016
DOI: 10.1016/J.CHEMOSPHERE.2016.01.060
Abstract: Currently, sludge pyrolysis has been considered as a promising technology to solve disposal problem of municipal sewage sludge, recover sludge heating value, sequester carbon and replenish nutrients in farmland soils. The resultant sludge-derived biochar (SDBC) is potentially an excellent stabilizing agent for metal species. This study applied the SDBC into four soils that had been contaminated in field with cationic Pb(II) and Cd(II)/Ni(II), and anionic Cr(VI) and As(III), respectively. The performance of metal stabilization under various operational and environmental conditions was evaluated with acid batch extraction and column leaching tests. Results indicated the SDBC could effectively stabilize these metals, which was favored by elevated temperature and longer aging. Periodic temperature decrease from 45 to 4 °C resulted in the release of immobilized Cr(VI) and As(III) but not Pb(II). However, a longer aging time offset such metal remobilization. This was possibly because more Pb was strongly bound and even formed stable precipitates, as shown by XRD and sequential extraction results. With increasing time, Cr(VI) was sorbed and partly reduced to Cr(III), while immobilized As(III) was co-oxidized to As(V) as indicated by XPS spectra. Column tests revealed that adding SDBC as a separate layer was unfavorable because the concentrated Cd(II) and Ni(II) in localized positions increased the peak levels of metal release under continuous acid leaching. In contrast, uniformly mixed SDBC could effectively delay the metal breakthrough and reduce their released amounts. Yet, a long-term monitoring may be required for evaluating the potential leaching risks and bioavailability/toxicity of these immobilized and transformed species in the SDBC-amended soils.
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.BIORTECH.2022.127601
Abstract: Net carbon management of agro-residues has been an important pathway for reducing the environmental burdens of agricultural production. Converting agro-residues into biochar through pyrolysis is a prominent management strategy for achieving carbon neutrality in a circular economy, meeting both environmental and social concerns. Based on the latest studies, this study critically analyzes the life cycle assessment (LCA) of biochar production from different agro-residues and compares typical technologies for biochar production. Although a direct comparison of results is not always feasible due to different functional units and system boundaries, the net carbon sequestration potential of biochar technology is remarkably promising. By pyrolyzing agro-residues, biochar can be effectively produced and customized as: (i) alternative energy source, (ii) soil amendment, and (iii) activated carbon substitution. The combination of life cycle assessment and circular economy modelling is encouraged to achieve greener and sustainable biochar production.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.JHAZMAT.2018.12.101
Abstract: Antimony (Sb) mobilization in sediments and its impact on water quality remained to be studied. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) technique were used to measure soluble Sb and labile Sb in sediment-overlying water profiles for a full year in a eutrophic region of Lake Taihu. Results showed that the highest mean concentrations of soluble Sb in overlying water (11.27 and 6.99 μg/L) appeared in December 2016 and January 2017, due to oxidation of Sb(III) to Sb(V) by Mn and Fe oxides, all of which exceeded the surface or drinking water limits set by China, United States and European Union. From April to November 2016, the concentrations of soluble Sb remained low with small monthly fluctuations and mean values ranging from 1.79 to 2.93 μg/L. This was attributed to the predominance of insoluble Sb(III) in sediments under anoxic conditions. The concentration of soluble Sb was slightly higher in summer than in autumn, due to the complexation of Sb(III) with DOM, as shown under anaerobic incubation. The mobility of inorganic Sb in sediments was mostly determined by the transition between Sb(III) and Sb(V), with Sb pollution in bottom water during winter being of concern.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.SCITOTENV.2019.02.006
Abstract: In this work, the degradation of cefalexin, norfloxacin, and ofloxacin was examined via various advanced oxidation processes (AOPs). Direct photolysis by ultraviolet (UV) and vacuum ultra violet (VUV) was less effective for the degradation of fluoroquinolone antibiotics such as norfloxacin and ofloxacin than that of cefalexin. Both hydrogen peroxide (H
Publisher: Elsevier BV
Date: 07-2020
Publisher: Walter de Gruyter GmbH
Date: 27-06-2017
Abstract: Nanobiotechnology is an immensely potential invention, which is expected to bring about revolutionary changes in many aspects of essential human needs including medical treatments and foods. Although the technology has passed through its embryonic stage, its medical applications in preparing and delivering drugs to target cells of human bodies to cure incurable diseases are still under scientific scrutiny. A 2007 study suggests that Australia needs to have a review of its regulatory framework for nanotechnology by 2017. This article examines the current regulation of nanotechnology and its medical applications in Australia, and observes that it would be premature to impose any stringent regulation at this stage on medical experimentations. We are of the view that an excessively precautionary policy may hinder further research, which is critical to discovering the benefit and harm with certainty. Hence, in the greater interest of the facilitation of research and affirmation of benefits of this technology, we recommend that adopting a hybrid regulatory method composed of self-regulation and accommodating government regulation would be an appropriate policy approach to the regulation of nanobiotechnology. We also accept the need for a set of internationally harmonized policy principles to guide our actions in relation to this technology.
Publisher: American Chemical Society (ACS)
Date: 11-02-2023
Publisher: Mary Ann Liebert Inc
Date: 12-2013
Publisher: Springer Science and Business Media LLC
Date: 23-06-2020
Publisher: American Chemical Society (ACS)
Date: 25-10-2022
Publisher: American Chemical Society (ACS)
Date: 17-04-2007
DOI: 10.1021/ES061756M
Abstract: EDTA-flushing of artificially contaminated soils enhanced Cu extraction but also induced mineral dissolution simultaneously. The mobilization and transport of these metal-EDTA complexes was investigated with column experiments. A quantitative transport model was proposed for simulating the experimental breakthrough curves of Cu, Fe, Al, and Ca. The rate-limited EDTA-promoted extraction and dissolution could be described by respective second-order kinetic terms, which were necessary for explaining the time-dependent depletion of extractable metals (sorbed and indigenous) in soils with continuous EDTA-flushing. Simultaneous simulation of extraction of sorbed Cu and dissolution of soil Fe, Al, and Ca is more conceptually accurate than in idual modeling of each metal because the latter approach tends to overestimate the concentration of free EDTA during transport and thus underestimate the rate coefficients of EDTA-promoted dissolution. The fitted rate coefficients of Cu were about an order of magnitude larger than those of Fe and Al these values probably reflect Cu extraction from weakly sorbed fractions and Fe and Al dissolution from amorphous oxides. The apparent retardation of Fe, Al, and Ca transport had to be taken into account by empirical determination, which was attributed to the metal lability in soils and thermodynamics of surface complexation.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.WASMAN.2018.11.016
Abstract: Changing in idual's recycling attitude and behaviour is of utmost importance in achieving sustainable construction and demolition (C&D) waste management, yet it has often been underachieved. To understand the motivations for recycling, this study identifies and prioritizes the key factors that affect C&D waste recycling behaviour of various stakeholders in Hong Kong (i.e., representatives from construction-waste-related organizations, environmental consultants and contractors, and government engineers) in a quantitative manner using statistical tools. Different from traditional C&D waste behavioural determinants studies, this paper utilizes an integrated analytical method through semi-structured interviews and survey questionnaire on the basis of Theory of Planned Behaviour (TPB). Qualitative thematic analysis and quantitative frequency analysis were performed to analyse responses from semi-structured interviews and questionnaires, followed by correlation analysis to quantify the relationships between factors. Results indicated that four key factors: (i) regulatory compliance, (ii) economic incentives, (iii) accreditation scheme, and (iv) logistics and management incentives directly influenced recycling behaviour of in iduals. Regulatory compliance was the most determining factor for consultants, contractors, experts, and government officials, whereas economic incentives were of great concern to the public. Under the factor of economic incentives, strong positive relationships were identified between disposal costs and collection and sorting costs, thus increasing waste disposal charging fee may promote recycling behaviour. In comparison, accreditation scheme deserved better recognition to facilitate a closed-loop material flow in the construction industry. These findings help to devise more effective and stakeholder-oriented policy tools to raise awareness and encourage behavioural change towards C&D waste recycling, and assist policy makers to establish regulations and practices for sustainable resource management.
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 04-2023
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.SCITOTENV.2017.10.310
Abstract: In this study, soil washing and stabilization as a two-step soil remediation strategy was performed to remediate Pb- and Cu-contaminated soils from shooting range and railway sites. Ferric nitrate (Fe(NO
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.ENVINT.2018.11.045
Abstract: In this study, a magnesium oxide (MgO) coated corncob biochar (MCB) was synthesized by pyrolyzing MgCl
Publisher: Springer Science and Business Media LLC
Date: 27-11-2017
DOI: 10.1007/S11356-017-0524-Y
Abstract: Cu(II)-catalyzed hydrolysis of β-lactam antibiotics has been well-identified and recognized as the key mechanism of antibiotic degradation. However, the overlooked Cu(II) oxidation susceptibly also plays an important role comparably with hydrolysis. This study evaluated the roles of hydrolysis and oxidation in Cu(II)-catalyzed degraded icillin (AMP), as a typical β-lactam antibiotic, under relevant environmental conditions (pH 5.0, 7.0, and 9.0 oxygen 0.2 and 6.2 mg/L). Under AMP and Cu(II) molar ratio of 1:1, AMP degradation was the fastest at pH 9.0, followed by pH 5.0 and pH 7.0. The facilitation of oxygen on AMP degradation was notable at pH 5.0 and 7.0 rather than pH 9.0. AMP degradation rate increased from 21.8% in 0.2 mg/L O
Publisher: Elsevier BV
Date: 05-2013
DOI: 10.1016/J.CHEMOSPHERE.2013.02.034
Abstract: Understanding the transport of metal-chelant complexes is a challenging but necessary task for assessing the in situ chelant applications for land remediation and the potential environmental risks. This study presented an integrated conceptual framework for delineating primary and secondary interactions between target metals, chelants and soil components. The mathematical transport model based on primary interactions reasonably simulated the breakthrough curves of multiple target metals (Cu, Zn, Pb, Cr, and Ni) and mineral cations (Fe, Al, Mg, Mn, and Ca) during EDTA flushing of a field-contaminated soil. The first-order extraction rates of target metals were on the order of 10(-6)s(-1), except Zn (10(-4)s(-1)) due to exceptionally large extractable amount in the soil. These rates compared well with previously reported values for field-contaminated soil, but were much smaller than those for artificially contaminated soil. The first-order dissolution rates of mineral cations (10(-6)-10(-5)s(-1)) were similar to the reported values for crystalline minerals, except Ca (10(-4)s(-1)) because of substantial proton-induced dissolution of carbonates. Nevertheless, due to a wide spectrum of extraction and dissolution rates at different stages, the model provided a more conservative prediction (i.e., overestimation) of metal-chelant transport while underestimated the transport of free chelant. Further revision of the proposed model may improve its prediction accuracy but attention should be paid to the model complexity and the number of adjustable parameters.
Publisher: Informa UK Limited
Date: 11-12-2018
Publisher: Wiley
Date: 05-2007
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.08.005
Abstract: There is a great heterogeneity in the distribution of mobile phosphorus (P) in natural sediments, while the assessment of P immobilization by amendment agents has mostly neglected this feature. In this study, the effects of aluminum sulfate (ALS) on P immobilization were investigated via a 60-day microcosm experiment using s led sediment cores. The high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) techniques were first employed to establish the profiles of soluble reactive P (SRP) and DGT-labile P in aluminum-amended sediments at 2 and 1 mm resolutions, respectively. Both concentrations of two mobile P forms decreased with increasing ALS dosages. The static layers with extremely low P concentrations (≤0.060 mg L
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.JHAZMAT.2019.120951
Abstract: In this study, concrete slurry waste (CSW) obtained from ready-mixed concrete plants was recycled as a fresh cementitious binder and used together with municipal solid waste incineration (MSWI) fine bottom ash (IBA) from waste-to-energy plants to produce cold bonded lightweight aggregates (CBLAs) by using a pelletizing technique. The influence of different curing methods on the properties of the produced CBLAs were experimentally investigated, including moist curing, steam curing, and accelerated CO
Publisher: Springer Science and Business Media LLC
Date: 18-07-2016
DOI: 10.1007/S10653-016-9851-Z
Abstract: Pyrolyzing sludge into biochar is a potentially promising recycling/disposal solution for municipal wastewater sludge, and the sludge-derived biochar (SDBC) presents an excellent sorbent for metal immobilization. As SDBC is composed of both mineral oxides and carbonized organic compartment, this study therefore compared the sorption behaviour of Pb and Zn on SDBC to those of in idual and mixture of activated carbon (AC) and amorphous aluminium oxide (Al
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.JCIS.2019.11.004
Abstract: While Co
Publisher: Wiley
Date: 22-02-2018
DOI: 10.1002/LDR.2896
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.ENVPOL.2019.07.059
Abstract: The effluents from nuclear mining processes contain relatively high content of radionuclides (such as uranium), which may seriously threaten the environment and human health. Herein, a novel adsorbent, porous hydroxyapatite, was prepared and proven highly efficient for removal of uranyl ions (U(VI)) given its high U(VI) uptake capacity of 111.4 mg/g, fast adsorption kinetics, and the potential stabilization of adsorbed U(VI). A nearly complete removal of U(VI) was achieved by porous HAP under optimized conditions. Langmuir model could well describe the adsorption equilibrium. The data fit well with pseudo-second-order kinetic model, suggesting that U(VI) adsorption is primarily attributed to chemisorption with porous HAP. Intraparticle diffusion analysis showed that the intraparticle diffusion is the rate-limiting step for U(VI) adsorption by porous HAP. After removal by porous HAP, the adsorbed U(VI) ions were incorporated into tetragonal autunite, which has a low solubility (log Ksp: -48.36). Our findings demonstrate that the porous HAP can effectively remediate uranium contamination and holds great promise for environmental applications.
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.ENVINT.2018.06.012
Abstract: In the recent techno-scientific revolution, nanotechnology has gained popularity at a rapid pace in different sectors and disciplines, specifically environmental, sensing, bioenergy, and agricultural systems. Controlled, easy, economical, and safe synthesis of nanomaterials is desired for the development of new-age nanotechnology. In general, nanomaterial synthesis techniques, such as chemical synthesis, are not completely safe or environmentally friendly due to harmful chemicals used or to toxic by-products produced. Moreover, a few nanomaterials are present as by-product during washing process, which may accumulate in water, air, and soil system to pose serious threats to plants, animals, and microbes. In contrast, using plants for nanomaterial (especially nanoparticle) synthesis has proven to be environmentally safe and economical. The role of plants as a source of nanoparticles is also likely to expand the number of options for sustainable green renewable energy, especially in biorefineries. Despite several advantages of nanotechnology, the nano-revolution has aroused concerns in terms of the fate of nanoparticles in the environment because of the potential health impacts caused by nanotoxicity upon their release. In the present panoramic review, we discuss the possibility that a multitudinous array of nanoparticles may find applications convergent with human welfare based on the synthesis of erse nanoparticles from plants and their extracts. The significance of plant-nanoparticle interactions has been elucidated further for nanoparticle synthesis, applications of nanoparticles, and the disadvantages of using plants for synthesizing nanoparticles. Finally, we discuss future prospects of plant-nanoparticle interactions in relation to the environment, energy, and agriculture with implications in nanotechnology.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.BIORTECH.2019.121878
Abstract: Lignin is one of the most promising renewable sources for aromatic hydrocarbons, while effective depolymerization towards its constituent monomers is a particular challenge because of the structural complexity and stability. Intensive research efforts have been directed towards exploiting effective valorization of lignin for the production of bio-based platform chemicals and fuels. The present contribution aims to provide a critical review of key advances in the identification of exact lignin structure subjected to various fractionation technologies and demonstrate the key roles of lignin structures in depolymerization for unique functionalized products. Various technologies (e.g., thermocatalytic approaches, photocatalytic conversion, and mechanochemical depolymerization) are reviewed and evaluated in terms of feasibility and potential for further upgrading. Overall, advances in pristine lignin structure analysis and conversion technologies can facilitate recovery and subsequent utilization of lignin towards tailored commodity chemicals and fungible fuels.
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.JHAZMAT.2021.126997
Abstract: Thallium (Tl) is an extremely toxic metal, while its occurrence and fate in paddy soil environment remain understudied. Herein, the enrichment and migration mechanisms and potential health risks of Tl and metal(loid)s were evaluated in paddy soils surrounding an industrial park utilizing Tl-bearing minerals. The results showed that Tl contamination was evident (0.63-3.16 mg/kg) in the paddy soils and Tl was generally enriched in root of rice (Oryza sativa L.) with a mean content of 1.27 mg/kg. A remarkably high level of Tl(III) (30-50%) was observed in the paddy soils. Further analyses by STEM-EDS and XPS indicated that Tl(I) in the paddy soils was jointly controlled by adsorption, oxidation, and precipitation of Fe/Mn(hydr)oxide (e.g. hematite and birnessite), which might act as important stabilization mechanisms for inhibiting potential Tl uptake by rice grains. The health quotient (HQ) values indicated a potentially high Tl risk for inhabitants via consumption of the rice grains. Therefore, it is critical to establish effective measures for controlling the discharge of Tl-containing waste and wastewater from different industrial activities to ensure food safety in the rice paddy soils.
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JHAZMAT.2019.03.077
Abstract: Layered double hydroxides (LDHs) have been intensively studied in recent years owing to their great potential in CO
Publisher: American Chemical Society (ACS)
Date: 06-01-2009
DOI: 10.1021/ES802030K
Abstract: Biodegradable EDDS ([S,S]-ethylenediaminedisuccinic acid) is an emerging chelant for enhancing heavy metal extraction. During soil remediation that involves continuous flushing, metal extraction is often limited by the amount of EDDS. Under EDDS deficiency, initial extraction of Zn and Pb followed by resorption was observed in batch kinetic experiments. Speciation calculations indicated that the percentages of ZnEDDS(2-) and PbEDDS(2-) in respective dissolved metal concentrations decreased with time, whereas the contribution of CuEDDS(2-) to total EDDS increased accordingly. This pointed to the metal exchange of newly formed ZnEDDS(2-) and PbEDDS(2-) with sorbed Cu on the soil surfaces, rather than with Fe oxides. A portion of displaced Zn and Pb was resorbed on the exchangeable and carbonate fractions, whereas the rest was mainly bound to dissolved organic matter (DOM) and remained in solution. On the other hand, although dissolved Al was the major mineral cation in solution under EDDS deficiency, the resulting competitive effect on metal extraction was marginal because Al readily dissociated from EDDS complexes and predominantly existed as colloidal precipitates, DOM-complexes, or hydrolyzed species. By contrast, under EDDS excess, metal resorption was indiscernible while more significant Al and Fe dissolution influenced the EDDS speciation.
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 12-2021
DOI: 10.1016/J.BIORTECH.2018.08.065
Abstract: Lignin is an abundant biomass resource in aromatic structure with a low price in market, which can serve as renewable precursors of value-added products. However, valorization rate of annually produced lignin is less than 2%, suggesting the need for technological advancement to capitalize lignin as a versatile feedstock. In recent years, efficient utilization of lignin has attracted wide attention. This paper summarizes the research advances in the utilization of lignin resources (mainly in the last three years), with a particular emphasis on two major approaches of lignin utilization: catalytic degradation into aromatics and thermochemical treatment for carbon material production. Hydrogenolysis, direct pyrolysis, hydrothermal liquefaction, and hydrothermal carbonization of lignin are discussed in detail. Based on this critical review, future research directions and development prospects are proposed for sustainable and cost-effective lignin valorization.
Publisher: Elsevier BV
Date: 08-2018
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.BIORTECH.2017.06.177
Abstract: This review lays great emphasis on production and characteristics of biochar through gasification. Specifically, the physicochemical properties and yield of biochar through the erse gasification conditions associated with various types of biomass were extensively evaluated. In addition, potential application scenarios of biochar through gasification were explored and their environmental implications were discussed. To qualitatively evaluate biochar sustainability through the gasification process, all gasification products (i.e., syngas and biochar) were evaluated via life cycle assessment (LCA). A concept of balancing syngas and biochar production for an economically and environmentally feasible gasification system was proposed and relevant challenges and solutions were suggested in this review.
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.ENVPOL.2018.08.093
Abstract: Magnetic biochar (MBC) has been used to remove hexavalent chromium (Cr(VI)) from water, but the roles of Fe
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.CHEMOSPHERE.2016.08.038
Abstract: The current contamination status of polychlorinated biphenyls (PCBs) was studied in the agricultural soils of the Yangtze River Delta (YRD), one of the largest economic zones in China. The concentrations of PCBs ranged from <0.1 to 130 ng/g dry weight. Higher concentrations of PCBs were observed in the 0-30 cm surface layers relative to the subsurface soils. A distinct spatial distribution was observed with a declining concentration gradient from the northwest to the southeast of the region. The composition of PCBs in the soils was consistent with the Chinese commercial PCB mixtures, but different from the compositions in global background soil. Local sources including large-scale use and disposal of PCB-containing products were the main potential sources to soil. The ecological effects and human health risks associated with combined persistent organic pollutants, including PCBs, organochlorine pesticides (OCPs), phthalate esters (PAEs) and polybrominated diphenyl ethers (PBDEs), were further estimated. The four toxic organic compounds and seven physicochemical parameters together could only explain 12.7% of the variation in microbial community composition, suggesting the soil ecosystem function was not strongly influenced by the combined pollution at low concentrations. However, the potential health risks to residents via multiple pathways were notably higher for PCBs than other chemicals. The potential risks were mainly derived from PCB-126, 81, and 169.
Publisher: Informa UK Limited
Date: 06-04-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0GC01281E
Abstract: Influence of exogenous and endogenous factors on phosphorus solid–liquid transformation during the hydrothermal processing of swine manure.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 12-2021
Publisher: Springer Science and Business Media LLC
Date: 07-12-2016
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 2021
DOI: 10.1016/J.ENVINT.2020.106207
Abstract: Industrial activities tend to deteriorate adjacent agricultural lands due to accumulation of potentially toxic elements in soils and crops. However, better understanding of their distinctive source partitions and transfer process remains insufficient in steel-making area. The paper focuses on the pollution levels, health risks, and provenance identification of Tl, As, Pb, Cu, Ni, Co, Sb, Cd, Zn, Be, Cr, Fe, Mn, Mo, Sn, and V in common vegetables from different farmlands near a steel-making plant. The results showed that the Tl, As, Pb, Cd, Cr, Cu and Mn were of high-level contamination in soils and generally above the maximum permissible level (MPL). Calculation using hazard quotients (HQ) exhibited that consumption of the studied vegetables may entail significant health risks to residents, especially for children, resulting from the elevated contents of Tl, As and associated toxic elements. Calculation by binary mixing model using Pb isotopic compositions suggested that steel-making activities contributed to 35-80% of the contamination of Pb and As in vegetables. It is necessary to adopt appropriate remediation measures to mitigate the farmland contamination and ensure the food safety of the agricultural products.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.SCITOTENV.2018.01.052
Abstract: The aim of this study was to develop a new approach for the preparation of spherical biochar (SBC) by employing a two-step thermal technology to potato peel waste (PPW). Potato starch (PS), as a carbon-rich material with microscale spherical shape, was separated from PPW as a precursor to synthesizing SBC. The synthesis process comprised (1) pre-oxidization (preheating under air) of PS at 220 °C and (2) subsequent pyrolysis of the pretreated s le at 700 °C. Results showed that the produced SBC successfully retained the original PS morphology and that pre-oxidization was the key for its shape maintenance, as it reduced surface tension and enhanced structural stability. The SBC possessed excellent chemical inertness (high aromaticity) and uniform particle size (10-30 μm). Zero-cost waste material with a facile and easy-to-control process allows the method to be readily scalable for industrialization, while offering a new perspective on the full use of PPW.
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 03-2011
DOI: 10.1016/J.CHEMOSPHERE.2011.01.040
Abstract: Chelating agents have been widely studied for extracting heavy metals from contaminated soils, and the effectiveness of EDDS ([S,S]-ethylene-diamine-disuccinic acid) has aroused extensive attention because of its biodegradability in the natural environment. However, in the course of EDDS-flushing, metal exchange of newly extracted metal-EDDS complexes with other sorbed metals and mineral cations may result in metal re-adsorption on the soil surfaces. Therefore, this study investigated the relative significance of metal exchange under different travel distances of chelant complexes, characteristics of soil contamination, and solution pH in the column experiments. As a result of metal exchange, the elution of Zn and Pb was retarded and the cumulative extraction was lower than those of Ni and Cu, especially over a longer travel distance. Compared with the field-contaminated soils, the effects of metal exchange were even more substantial in the artificially contaminated soil because of a greater amount of extractable metals and a larger proportion of weakly bound fractions. By contrast, metal exchange was insignificant at pH 8, probably due to less adsorption of metal-EDDS complexes. These findings highlight the conditions under which metal exchange of metal-EDDS complexes and the resulting impacts are more significant during EDDS-flushing.
Publisher: Elsevier BV
Date: 02-2021
Publisher: American Society of Civil Engineers (ASCE)
Date: 05-2008
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 03-2022
Publisher: Springer Science and Business Media LLC
Date: 29-06-2022
DOI: 10.1007/S44246-022-00010-8
Abstract: Soil organic carbon (SOC) is a crucial component that significantly affects the soil fertility, soil remediation, and carbon sequestration. Here, we review the redox-induced transformation of potentially toxic elements (PTEs) through the abiotic impact of SOC. The complex composition of SOC includes humus, pyrogenic carbon (e.g., biochar), dissolved organic matter, and anthropogenic carbon (e.g., compost), with varying concentrations and properties. The primary redox moieties on organic carbon are surface functionalities (e.g., phenol, quinone, and N/S-containing functional groups), environmentally persistent free radicals, and graphitic structures, and their contents are highly variable. Owing to these rich redox moieties, organic carbon can directly affect the reduction and oxidation of PTEs in the soil, such as Cr(VI) reduction and As(III) oxidation. In addition, the interactions between organic carbon and soil redox moieties (i.e., O 2 , Fe, and Mn minerals) cause the transformation of PTEs. The formation of reactive oxygen species, Fe(II), and Mn(III)/Mn(II) is the main contributor to the redox-induced transformation of PTEs, including Cr(VI) reduction and As(III)/Cr(III)/Tl(I) oxidation. We articulated both the positive and negative effects of organic carbon on the redox-induced transformation of PTEs, which could guide soil remediation efforts. Further scientific studies are necessary to better understand the potential transformations of PTEs by SOC, considering the complicated soil moieties, variable organic carbon composition, and both biotic and abiotic transformations of PTEs in the environment. Graphical Abstract
Publisher: American Chemical Society (ACS)
Date: 23-06-2022
Abstract: Electroplating sludge is a hazardous waste due to its high potential to leach toxic elements into the natural environment. To alleviate this issue, we tailored magnesium phosphate cement (MPC) as a low-carbon material for stabilization/solidification (S/S) of Zn-rich electroplating sludge. The interaction between MPC and ZnO was investigated to clarify the precipitate chemistry, microstructure transition, and chemical environment of Zn species in the MPC-treated Zn sludge system. Comprehensive characterization (by X-ray diffraction (XRD),
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 09-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3GC00472D
Abstract: Spent lithium iron phosphate batteries can be successfully regenerated via a pollution-free, short-range, and low-carbon hydro-oxygen repair route.
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.BIORTECH.2022.127838
Abstract: This study innovated the concept in designing an efficient and reusable microwave (MW) absorbent through concurrent exploitation of carbon graphitization, oxygen functionalization, and carbothermal iron reduction underpinned by an endothermic co-pyrolysis of wood waste and low-dosage iron. A powerful MW assimilation was accomplished from nanoscale amorphous magnetic particles as well as graphitized microporous carbon-iron skeleton in the biochar composites. Relative to a weak magnetic loss derived from the iron phase, the graphitic carbon architecture with abundant surface functionalities (i.e., CO and CO) exhibited a strong dielectric loss, which was thus prioritized as major active sites during MW reuse. The MW-absorbing biochar demonstrated a fast, robust, and durable removal of a refractory herbicide (2,4-dichlorophenoxy acetic acid) under mild MW irradiation with zero chemical input, low electricity consumption, and negligible Fe dissolution. Overall, this study will foster carbon-neutral industrial wastewater treatment and wood waste valorization.
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.BIORTECH.2018.11.013
Abstract: In this study, red seaweed (Gracilaria lemaneiformis) food waste with high carbohydrate content was valorized into levulinic acid (LA) and algae hydrochar through microwave-assisted low-temperature hydrothermal treatment in dilute acid solution. Various parameters including treatment temperature (160-200 °C), reaction time (1-40 min), acid concentration (0-0.6 M), and biomass-to-liquid ratio (1%-10%, w/v) were examined. The energy efficiency and carbon recovery of the proposed process were investigated. Under the experimental conditions of 5% (w/v) biomass loading, 0.2 M H
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.SCITOTENV.2017.08.168
Abstract: This report proposes a new approach to evaluate the odour nuisance of cattle manure s les from three different cattle breeds (i.e., native cattle, beef cattle, and milk cow) by means of quantification and speciation of volatile fatty acids (VFAs). To this end, non-catalytic esterification thermally induced in the presence of a porous material (silica) was undertaken, and the optimal operational parameters such as the derivatizing temperature (330°C) for the maximum yield (≥99±0.4%) of volatile fatty acid methyl esters (VFAMEs) were established. Among the VFA species in cattle manure based on quantification of VFAs, the major species were acetic, butyric and valeric acid. Considering the odour threshold of each VFA, our experimental results suggested that the major contributors to odour nuisance were C
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.SCITOTENV.2020.136769
Abstract: Directly returning rice straw to the paddy soil would significantly stimulate methane emission, and hydrochar has potential to be used as soil conditioner. However, the effects of hydrochar on the methane emission from paddy soil and the related mechanisms are still unclear. In the present study, straw-based hydrochar obtained at 200 °C (HC200), 250 °C (HC250) and 300 °C (HC300) and hydrochar after removal of bio-oil at these temperatures (CHC200, CHC250, and CHC300) were prepared and added to the paddy soil. The application of HC200, HC250 and HC300 resulted in the enhanced methane production compared to the control, showing 4.3, 1.6 and 1.5-fold higher methane production, respectively. It was related to the large amount of dissolved organic matter (DOM) released from hydrochar. Excitation-emission matrix fluorescence spectroscopy with parallel factor analysis (EEM-PARAFAC) showed that the hydrochar-derived DOM mainly included humic-like, phenolic and less aromatic structures, and with the increase of hydrothermal temperature, the content of humic-like substances and phenols increased, while biodegradable organics decreased. This was consistent with the maximum methane production by HC200. After incubation, there was no low-aromatic structures observed in the soil leachate, and the residual organics were mainly humus. The EEM-PARAFAC results were supported by compositional characterization of soil leachate by high-resolution mass spectrometry, and the refractory organics released from hydrochar was mainly lignins or (CRAM)-like structures in the range of H/C = 0.8-1.6 and O/C = 0.1-0.5. The organics dissolved from the washed hydrochar was significantly reduced, and some washed hydrochar (CHC250 and CHC300) even inhibited methane emission possibly due to their ability to adsorb organics. Microbial analysis further showed that the increased methane production resulted from hydrochar was associated with the enrichment of Janibacter, Anaeromyxobacter, Anaerolinea and Sporacetigenium. This present study provided a better understanding to the effect of hydrochar on methanogenesis in paddy soil.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.ENVINT.2019.105247
Abstract: Elevated level of arsenic (As) in marine sediment via deposition and accumulation presents long-term ecological risks. This study proposed a sustainable stabilization/solidification (S/S) of As-contaminated sediment via novel valorization of red mud waste, blast furnace slag and calcined clay mineral, which were selected to mitigate the increased leaching of As under alkaline environment of S/S treatment. Quantitative X-ray diffraction and thermogravimetric analyses illustrated that stable Ca-As complexes (e.g., Ca
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.CHEMOSPHERE.2016.07.007
Abstract: Biochar is being widely considered as a promising amendment agent for immobilizing heavy metals in contaminated acidic soils, where plenty of soluble Al(III) ions exist. In view of uncertain significance of the effects of coexisting Al(III) on Pb(II) sorption by biochars, this study used kenaf core biochar (KB550 high carbon, low ash) and sewage sludge biochar (SB550 low carbon, high ash) pyrolyzed at 550 °C to elucidate the influence of coexisting Al(III) species and biochars' mineral components on Pb(II) immobilization conducted in aqueous solution with initial pHs of 3.0-4.5. Results showed that Al(III) reduced Pb(II) sorption on KB550 primarily via pH buffering against biochar alkalinity, thus inhibiting lead carbonate formation. In contrast, the reduction on SB550 mainly resulted from direct competition for sorption sites, especially on Fe-rich phengite 2M1 and metakaolinite. Because of Pb-P precipitation and Pb-K interlayer exchange, the residual Pb(II) adsorption capacity resistant to coexisting Al(III) was 3-5 times higher on SB550 than on KB550. The Pb-K interlayer exchange was enhanced by lower pH and coexisting Al(III), while Pb-P precipitation was the dominant Pb(II) sorption mechanism on SB550 resistant to Al(III) buffering and competition at higher pH. Application of these two biochars as amendments confirmed that the mineral-rich SB550 was more suitable for Pb(II) immobilization in acidic soils with high levels of extractable Al(III).
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 05-2017
DOI: 10.1016/J.CHEMOSPHERE.2017.01.148
Abstract: In order to determine the efficacy of vegetable waste and pine cone biochar for immobilization of metal/metalloid (lead and arsenic) and abundance of microbial community in different agricultural soils, we applied the biochar produced at two different temperatures to two contaminated soils. Biochar was produced by vegetable waste, pine cone, and their mixture (1:1 ww
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.SCITOTENV.2019.02.289
Abstract: Massive realgar tailings abandoned in mining areas in China have caused serious arsenic (As) pollution seeking for urgent disposal. Stabilization treatment is a feasible strategy, however, stabilization technologies for realgar tailings, that are Fe-deficient, Ca-rich and S-rich, have not been well developed to date. In this study, we conducted a pilot-scale stabilization treatment of realgar tailings via ferrous sulfate addition to evaluate the transformation of As during stabilization. We found that Si, As, Ca, and S were the predominant elements in the raw realgar tailings with a low content of Fe, and realgar (As
Publisher: Elsevier BV
Date: 10-2022
Publisher: Wiley
Date: 20-04-2020
DOI: 10.1111/SUM.12589
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 06-2020
Publisher: Informa UK Limited
Date: 02-05-2020
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.SCITOTENV.2019.02.160
Abstract: The objective of this field-scale study was to assess the effectiveness of applying an emulsified polycolloid substrate (EPS containing cane molasses, soybean oil, and surfactants) biobarrier in the control and remediation of a petroleum-hydrocarbon plume in natural waters. An abandoned petrochemical manufacturing facility site was contaminated by benzene and other petroleum products due to a leakage from a storage tank. Because benzene is a petroleum hydrocarbon with a high migration ability, it was used as the target compound in the field-scale study. Batch partition and sorption experiment results indicated that the EPS to water partition coefficient for benzene was 232 mg/mg at 25 °C. This suggests that benzene had a higher sorption affinity to EPS, which decreased the benzene concentrations in groundwater. The EPS solution was pressure-injected into three remediation wells (RWs 150 L EPS in 800 L groundwater). Groundwater s les were collected from an upgradient background well, two downgradient monitor wells (MWs), and the three RWs for analyses. EPS injection increased total organic carbon (TOC) concentrations (up to 786 mg/L) in groundwater, which also resulted in the formation of anaerobic conditions. An abrupt drop in benzene concentration (from 6.9 to below 0.04 mg/L) was observed after EPS supplementation in the RWs due to both sorption and biodegradation mechanisms. Results show that the EPS supplement increased total viable bacteria and enhanced bioremediation efficiency, which accounted for the observed decrease in benzene concentration. The first-order decay rate in RW1 increased from 0.003 to 0.023 d
Publisher: Informa UK Limited
Date: 07-08-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9GC01843C
Abstract: Engineered biochar synergized from copper heteroatoms and CO 2 fosters non-radical persulfate activation for sustainable remediation.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1GC01948A
Abstract: This study provides new and critical insights into sustainable catalytic conversion of food (bread) waste to platform chemicals for achieving sustainable development goals and fostering a circular economy.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.SCITOTENV.2017.12.337
Abstract: After the application of sludge derived biochar (SDBC) for soil stabilization, it is subjected to continuous leaching that may change its surface properties and metal(loid) immobilization performance. This study simulated the continuous leaching through the fresh SDBC s le in columns with unsaturated and saturated zones under flushing with 0.01M NaNO
Publisher: Elsevier BV
Date: 09-2020
Publisher: American Chemical Society (ACS)
Date: 12-02-2019
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.BIORTECH.2018.06.029
Abstract: Pyrolyzing low-cost agro-waste into biochar is a promising means for waste biomass utilization. This study engineers corn stalk-derived biochar with abundant hydrophilic functional groups as a support material for iron nanoparticles impregnation (nZVI-HCS). Surface chemistry and morphology of nZVI-HCS composites is characterized by SEM, TEM, TG, XRD, FTIR, XPS, and BET techniques, which helps to elucidate the mechanisms of Pb
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.ENVINT.2019.105015
Abstract: The accumulation of potentially toxic elements (PTEs) in aquatic ecosystems has become a global concern, as PTEs may exert a wide range of toxicological impacts on aquatic organisms. Submerged plants and the microorganisms attached to their surfaces, however, have displayed great potential as a means of coping with such pollution. Therefore, it is crucial to understand the transport pathways of PTEs across sediment and organisms as well as their accumulation mechanisms in the presence of submerged plants and their biofilms. The majority of previous studies have demonstrated that submerged plants and their biofilms are indicators of PTE pollution in the aquatic environment, yet relatively little is known about PTE accumulation in epiphytic biofilms. In this review, we describe the transport pathways of PTEs in the aquatic environment in order to offer remarkable insights into bioaccumulation mechanisms in submerged plants and their biofilms. Based on the literature cited in this review, the roles of epiphytic biofilms in bioaccumulation and as an indicator of ecosystem health are discussed.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.ENVINT.2019.105257
Abstract: Hydrothermal liquefaction of sewage sludge to produce bio-oil and hydro-char unavoidably results in the production of high-strength organic wastewater (HTLWW). However, anaerobic digestion (AD) of HTLWW generally has low conversion efficiency due to the presence of complex and refractory organics. The present study showed that granular activated carbon (GAC) promoted the AD of HTLWW in continuous experiments, resulting in the higher methane yield (259 mL/g COD) compared to control experiment (202 mL/g COD). It was found that GAC increased the activities of both aceticlastic and hydrogenotrophic methanogens. The molecular transformation of organics in HTLWW was further analyzed. It was shown GAC promoted the degradation of soluble microbial by-products, fulvic- and humic-like substances as revealed by 3-dimensional fluorescence excitation-emission matrix (3D-EEM) analysis. Gas chromatography mass spectrometry (GC-MS) analysis showed that GAC resulted in the higher degradation of N-heterocyclic compounds, acids and aromatic compounds and less production of new organic species. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) analysis also showed that GAC promoted the degradation of nitrogenous organics. In addition, it was shown that GAC improved the removal of less oxidized, higher nitrogen content, and higher double bond equivalent (DBE) organic compounds. Microbial analysis showed that GAC not only increased the microbial concentration, but also enriched more syntrophic bacteria (e.g., Syntrophorhabdus and Synergistes), which were capable of degrading a wide range of different organics including nitrogenous and aromatic organics. Furthermore, profound effects on the methanogens and the enrichment of Methanothrix instead of Methanosarcina were observed. Overall, the present study revealed the molecular transformation and microbial mechanism in the AD of HTLWW with the presence of GAC.
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.ENVINT.2019.105376
Abstract: Biochar can reduce the mobility and availability of potentially toxic elements (PTEs) in soils and improve soil properties. However, immobilization efficiencies of biochar can be varied according to environmental conditions, such as pH and redox potential (E
Publisher: American Chemical Society (ACS)
Date: 07-04-2020
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.BIORTECH.2017.12.098
Abstract: Sulfonated biochar derived from forestry wood waste was employed for the catalytic conversion of starch-rich food waste (e.g., bread) into 5-hydroxymethylfurfural (HMF). Chemical and physical properties of catalyst were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area, and elemental analysis. The conversion of HMF was investigated via controlling the reaction parameters such as catalyst loading, temperature, and reaction time. Under the optimum reaction conditions the HMF yield of 30.4 Cmol% (i.e., 22 wt% of bread waste) was achieved in the mixture of dimethylsulfoxide (DMSO)/deionized-water (DIW) at 180 °C in 20 min. The effectiveness of sulfonated biochar catalyst was positively correlated to the density of strong/weak Brønsted acidity (SO
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.SCITOTENV.2018.07.218
Abstract: Contamination of groundwater with toxic arsenic (As) has become an emerging health and environmental problem around the world, which has seen significant attention amongst the scientists for development of new sorbents to remediate As-contaminated water. Here, we explored the arsenate (As(V)) and arsenite (As(III)) sorption to natural water melon rind (WMR), xanthated WMR and citric acid-modified WMR in aqueous solutions, and determined potential of the most potent sorbent for As removal in groundwater. Xanthated WMR (X-WMR) showed relatively higher As(V) and As(III) removal than the citric acid modified WMR (CA-WMR) and natural WMR. The maximum As(III) (99%) and As(V) (98%) removal was obtained at pH 8.2 and 4.6, respectively, by X-WMR at 4 mg L
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.SCITOTENV.2017.12.348
Abstract: It is proposed that the internal loading of phosphorus (P) from sediments plays an important role in seasonal nitrogen (N) limitation for harmful algal blooms (HABs), although there is a lack of experimental evidence. In this study, an eutrophic bay from the large and shallow Lake Taihu was studied for investigating the contribution of internal P to N limitation over one-year field s ling (February 2016 to January 2017). A prebloom-bloom period was identified from February to August according to the increase in Chla concentration in the water column, during which the ratio of total N to total P (TN/TP) exponentially decreased with month from 43.4 to 7.4. High-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) analysis showed large variations in the vertical distribution of mobile P (SRP and DGT-labile P) in sediments, resulting in the SRP diffusion flux at the sediment-water interface ranging from -0.01 to 6.76mg/m
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.SCITOTENV.2017.08.187
Abstract: A novel nitrogen-doped biochar embedded with cobalt (Co-NB) was fabricated via pyrolysis of glucose pretreated with melamine (N donor) and Co(II). The Co-NB showed high catalytic capability by converting p-nitrophenol (PNP) into p-aminophenol (PAP) by NaBH
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.CHEMOSPHERE.2018.04.081
Abstract: Chelant-enhanced soil washing, such as EDTA (ethylenediaminetetraacetic acid) and biodegradable EDDS ([S,S]-ethylene-diamine-disuccinic acid), has been widely studied, however, EDTA is persistent under natural conditions while EDDS has a low efficiency for Pb extraction. Therefore, we investigated the efficacy of mixed chelants (EDDS and EDTA mixture at 1:1 M ratio) for the removal of Cu, Zn, and Pb from a field-contaminated soil using various washing schemes (multi-pulse, step-gradient chelant, and continuous washing schemes). Speciation modelling of the target metals, mineral elements, and EDDS/EDTA was performed, while the leachability and bioaccessibility of residual metals in the treated soils were also assessed. Our results suggested that the combined use of EDDS and EDTA reached equivalent extraction efficiency of the target metals as EDTA, i.e., 50% reduction in the dosage of EDTA was made possible. This was accomplished by selective extraction of Cu by EDDS and Pb by EDTA, which was supported by the results of speciation calculation. Multi-pulse washing scheme with intermittent water rinsing steps removed entrapped metal-chelant complexes and free chelants, therefore reducing the leachability and bioaccessibility of residual metals in the treated soils. Step-gradient chelant washing with the maximum dosage of chelants in the first washing step only achieved marginal improvement but undesirably promoted Pb bioaccessibility. Continuous washing for 24 h enhanced metal extraction but promoted mineral dissolution, together with a large amount of uncomplexed chelants and increase in Cu leachability. Thus the combined use of EDDS and EDTA in multi-pulse washing is recommended for further studies.
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.ENVPOL.2019.07.012
Abstract: Solid wastes containing potentially toxic elements (PTEs) are widely generated around the globe. Critical concerns have been raised over their impacts on human health and the environment, especially for the exposure to PTEs during the transfer and disposal of the wastes. It is important to devise highly-efficient and cost-effective treatment technologies for the removal or immobilisation of PTEs in solid wastes. However, there is an inadequate overview of the global flow of PTEs-contaminated solid wastes in terms of geographical distribution patterns, which is vital information for decision making in sustainable waste management. Moreover, in view of the scarcity of resources and the call for a circular economy, there is a pressing need to recover materials (e.g., precious metals and rare earth elements) from waste streams and this is a more sustainable and environmentally friendly practice compared with ore mining. Therefore, this article aims to give a thorough overview to the global flow of PTEs and the recovery of waste materials. This review first summarises PTEs content in various types of solid wastes then, toxic metal(loid)s, radioactive elements, and rare earth elements are critically reviewed, with respect to their patterns of transport transformation and risks in the changing environment. Different treatments for the management of these contaminated solid wastes are discussed. Based on an improved understanding of the dynamics of metal(loid) fates and a review of existing management options, new scientific insights are provided for future research in the development of high-performance and sustainable treatment technologies for PTEs in solid wastes.
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.CHEMOSPHERE.2017.09.114
Abstract: Inorganic binder-based stabilization/solidification (S/S) of Pb-contaminated soil is a commonly used remediation approach. This paper investigates the influences of soluble Pb species on the hydration process of two types of inorganic binders: ordinary Portland cement (OPC) and magnesium potassium phosphate cement (MKPC). The environmental leachability, compressive strength, and setting time of the cement products are assessed as the primary performance indicators. The mechanisms of Pb involved in the hydration process are analyzed through X-ray diffraction (XRD), hydration heat evolution, and thermogravimetric analyses. Results show that the presence of Pb imposes adverse impact on the compressive strength (decreased by 30.4%) and the final setting time (prolonged by 334.7%) of OPC, but it exerts much less influence on those of MKPC. The reduced strength and delayed setting are attributed to the retarded hydration reaction rate of OPC during the induction period. These results suggest that the OPC-based S/S of soluble Pb mainly depends on physical encapsulation by calcium-silicate-hydrate (CSH) gels. In contrast, in case of MKPC-based S/S process, chemical stabilization with residual phosphate (pyromorphite and lead phosphate precipitation) and physical fixation of cementitious struvite-K are the major mechanisms. Therefore, MKPC is a more efficient and chemically stable inorganic binder for the Pb S/S process.
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.BIORTECH.2017.04.026
Abstract: Conversion of biomass waste to hydroxymethylfurfural (HMF), a value-added platform chemical, has captured great research interests driven by the economic and environmental incentives. This review evaluates the recent development of biomass conversion systems for high HMF yield and selectivity, with a focus on the performance of emerging catalysts and solvents from a mechanistic view. We highlight that the ratio and strength of Brønsted and Lewis acid in bifunctional catalyst are critical for maximizing HMF production by selective improvement in the kinetics of desirable reactions (hydrolysis, isomerization, and dehydration) over undesirable reactions (rehydration, polymerization). The characteristics of solvent mixture such as functional groups and speciation govern the reactivity of substrate towards desirable reactions and stability of HMF and intermediates against side reactions. Research efforts to unravel the interactions among co-catalysts/co-solvents and between catalysts and solvents are encouraged, thereby engineering a synergistic conversion system for biomass valorization.
Publisher: Wiley
Date: 30-05-2020
DOI: 10.1111/SUM.12592
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.JENVMAN.2019.109513
Abstract: Thallium (Tl) is an uncommon toxic element, with an even greater toxicity than that of As, Hg and Cd. Steel-making industry has been identified as an emerging new significant source of Tl contamination in China. This paper presents a pilot investigation of the contamination and geochemical transfer of Tl and associated metal(loid)s in river sediments affected by long-term waste discharge from the steel-making industry. The results uncovered an overall Tl contamination (1.96 ± 0.42 mg/kg) across a sediment profile of approximately 1.5 m in length, even 10 km downstream the steel plant. Highly elevated contents of Pb, Cu, Cd, Zn and Sb were found in the fluvial sediments, displaying strong positive correlations with Tl contents. Elevated levels of geochemically mobile Tl as well as Cd, Zn, Cu and Pb occurred in the fluvial sediments, signifying anthropogenic imprints from steel production activities at high temperature. Levels of contamination and ecological risk were calculated to be moderate to considerable for Tl, Cu, Zn and high to very high for Cd, Pb, Sb. The results highlight that there is a great challenge in view of potentially considerable Tl pollution due to continuous massive steel production in many other parts of China. It is high time to initiate process-based management of Tl contamination control for the ambient aquifer system in the steel-making area.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.ENVPOL.2018.12.031
Abstract: Iron (Fe) and manganese (Mn) reactions have been regarded as the primary factors responsible for the mobilization of phosphorus (P) in lake sediments, although their in idual roles are hard to distinguish. In this study, in situ mobilization of P, Fe and Mn in sediments was assessed by high resolution spatio-temporal s ling of their labile forms using diffusive gradient in thin films (DGT) and suction device (Rhizon) techniques. It was found that the monthly concentration distributions showed greater agreement and better correlation coefficients between labile P and labile Fe, than those between labile P and labile Mn, implying that Fe plays a key role in controlling P release in sediments. Furthermore, better correlations were observed between hourly changes in concentrations of soluble reactive phosphorus (SRP) and soluble Fe(II), than those between SRP and soluble Mn. Changes were observed under simulated anaerobic incubation conditions, suggesting that P release was caused by the reductive dissolution of Fe oxides. This was supported by the lack of influences on P release from reductive dissolution of Mn oxides in the sediment-water interface and top sediment layers under the anaerobic incubations. In simulated algal bloom experiments, positive correlations and consistent changes were observed between SRP and soluble Fe(II) concentrations, but not between SRP and soluble Mn concentrations. This further demonstrated the Fe-dependent and Mn-independent release of P in sediments. Therefore, Fe redox reactions have a high impact on P mobilization in sediments, while Mn redox reactions appear to have negligible influences.
Publisher: Springer Science and Business Media LLC
Date: 28-03-2017
DOI: 10.1007/S11356-017-8770-6
Abstract: Considering the resource waste and environmental burden for timber and plastic materials ending up at landfills, this study proposed upcycling wood and plastic waste into value-added wood-plastic composites (WPCs), complying with the standard requirements of flexural strength, thickness swelling, water absorption and thermal insulation. Biological deterioration is a major concern of WPCs. Bacterial survival, fungal attack and algal growth of bactericide-treated WPCs were holistically analysed. Melamine resin was adopted for impregnating anti-microbial agents on the surface. All the agents showed excellent bactericidal rate (Escherichia coli), yet poly-diallyl-dimethyl-ammonium chloride (PolyDADMAC) and silver had the lowest minimum inhibitory concentrations. In terms of weight loss and strength reduction due to fungal decay (Coriolus versicolor), PolyDADMAC, silver and cetyltrimethylammonium bromide (CTAB) imparted the highest resistance on the WPCs. Moreover, PolyDADMAC and copper provided the most protection against algal growth (Chlorella vulgaris), and the former presented durable inhibitory effect. This study presents a value-added solution to wood lastic waste recycling.
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.ENVINT.2018.12.049
Abstract: Globally, contamination of groundwater with toxic arsenic (As) is an environmental and public health issue given to its carcinogenic properties, thereby threatening millions of people relying on drinking As-contaminated well water. Here, we explored the efficiency of various biosorbents (egg shell, java plum seed, water chestnut shell, corn cob, tea waste and pomegranate peel) for arsenate (As(V)) and arsenite (As(III)) removal from As-contaminated water. Significantly, egg shell and java plum seed displayed the greatest As(III) elimination (78-87%) at 7 pH followed by water chestnut shell (75%), corn cob (67%), tea waste (74%) and pomegranate peel (65%). In contrast, 71% and 67% of As(V) was removed at pH 4.1 and 5.3 by egg shell and java plum seed, respectively. The maximum As(V) and As(III) sorption by all the biosorbents was obtained, notably for egg shell and java plum seed, after 2 h contact time. Langmuir isotherm and pseudo-second order models best fitted the sorption data for both forms of As. The -OH, -COOH, -NH
Publisher: Elsevier BV
Date: 07-2019
Publisher: Elsevier BV
Date: 08-2020
Location: No location found
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Daniel C.W. Tsang.