ORCID Profile
0000-0001-6454-3264
Current Organisations
Aalto University
,
Federation University
,
New York University Abu Dhabi
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Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 08-2022
Publisher: Elsevier BV
Date: 07-2023
Publisher: Elsevier BV
Date: 2023
DOI: 10.1016/J.CHEMOSPHERE.2022.137133
Abstract: In recent years, enzymatic remediation/biocatalysis has gained prominence for the bioremediation of recalcitrant chemicals. Laccase is one of the commonly investigated enzymes for bioremediation applications. There is a growing interest in immobilizing this enzyme onto adsorbents for achieving high pollutant removal through simultaneous adsorption and biodegradation. Due to the influence of the biomolecule-support interface on laccase activity and stability, it is crucial to functionalize the solid carrier prior to immobilization. Date stone (PDS), as an eco-friendly, low-cost, and effective natural adsorbent, was utilized as a carrier for laccase (fungus Trametes versicolor). After activating PDS through chemical treatments, the surface area increased by thirty-six-fold, and carbonyl groups became more prominent. Batch experiments were carried out for ketoprofen and aspirin biodegradation in aqueous solutions. After six cycles, the laccase maintained 54% of its original activity confirmed by oxidation tests of 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). In addition, the storage, pH, and thermal stability of immobilized laccase on functionalized date stone (LFPDS) were found to be superior to that of free laccase, demonstrating its potential for ongoing applications. In the aqueous batch mode, this immobilized laccase system was used to degrade 25 mg L
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.ULTSONCH.2015.05.007
Abstract: There is a limited work on the use of pulsed ultrasound for water disinfection particularly the case of natural water. Hence, pulsed ultrasound disinfection of natural water was thoroughly investigated in this study along with continuous ultrasound as a standard for comparison. Total coliform measurements were applied to evaluate treatment efficiency. Factorial design of 2(3) for the tested experimental factors such as power, treatment time and operational mode was applied. Two levels of power with 40% and 70% litudes, treatment time of 5 and 15 min and operational modes of continuous and pulsed with On to Off ratio (R) of 0.1:0.6 s were investigated. Results showed that increasing power and treatment time or both increases total coliform reduction, whereas switching from continuous to pulsed mode in combination with power and treatment time has negative effect on total coliform reduction. A regression model for predicting total coliform reduction under different operating conditions was developed and validated. Energy and cost analyses applying electrical and calorimetric powers were conducted to serve as selection guidelines for the choosing optimum parameters of ultrasound disinfection. The outcome of these analyses indicated that low power level, short treatment time, and high R ratios are the most effective operating parameters.
Publisher: Elsevier BV
Date: 07-2020
Publisher: IntechOpen
Date: 25-03-2020
Publisher: Elsevier BV
Date: 2021
Publisher: MDPI AG
Date: 27-08-2022
DOI: 10.3390/MEMBRANES12090837
Abstract: Membrane contactor technology affords great opportunities for nitrogen recovery from waste streams. This study presents a performance comparison between lab- and pilot-scale membrane contactors using landfill leachate s les. Polypropylene (PP) and polytetrafluoroethylene (PTFE) fibers in different dimensions were compared in terms of ammonia (NH3) recovery on a lab scale using a synthetic ammonium solution. The effect of pre-treating the leachate with tannin coagulation on nitrogen recovery was also evaluated. An ammonia transfer on the lab and pilot scale was scrutinized using landfill leachate as a feed solution. It was found that PTFE fibers performed better than PP fibers. Among PTFE fibers, the most porous one (denoted as M1) had the highest NH3 flux of 19.2 g/m2.h. Tannin pre-treatment reduced fouling and increased NH3, which in turn improved nitrogen recovery. The mass transfer coefficient of the lab-scale reactor was more than double that of the pilot reactor (1.80 × 10−7 m/s vs. 4.45 × 10−7 m/s). This was likely attributed to the difference in reactor design. An analysis of the membrane surface showed that the landfill leachate caused a combination of inorganic and organic fouling. Cleaning with UV and 0.01 M H2O2 was capable of removing the fouling completely and restoring the membrane characteristics.
Publisher: MDPI AG
Date: 29-04-2023
DOI: 10.3390/MEMBRANES13050483
Abstract: This study addressed the fouling issue in membrane distillation (M.D.) technology, a promising method for water purification and wastewater reclamation. To enhance the anti-fouling properties of the M.D. membrane, a tin sulfide (TS) coating onto polytetrafluoroethylene (PTFE) was proposed and evaluated with air gap membrane distillation (AGMD) using landfill leachate wastewater at high recovery rates (80% and 90%). The presence of TS on the membrane surface was confirmed using various techniques, such as Field Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Energy Dispersive Spectroscopy (EDS), contact angle measurement, and porosity analysis. The results indicated the TS-PTFE membrane exhibited better anti-fouling properties than the pristine PTFE membrane, and its fouling factors (FFs) were 10.4–13.1% compared to 14.4–16.5% for the PTFE membrane. The fouling was attributed to pore blockage and cake formation of carbonous and nitrogenous compounds. The study also found that physical cleaning with deionized (DI) water effectively restored the water flux, with more than 97% recovered for the TS-PTFE membrane. Additionally, the TS-PTFE membrane showed better water flux and product quality at 55 °C and excellent stability in maintaining the contact angle over time compared to the PTFE membrane.
Publisher: Desalination Publications
Date: 2018
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.ULTRAS.2014.10.003
Abstract: Obtaining accurate power characteristics of ultrasonic treatment systems is an important step towards their industrial scalability. Calorimetric measurements are most commonly used for quantifying the dissipated ultrasonic power. However, accuracy of these measurements is affected by various heat losses, especially when working at high power densities. In this work, electrical power measurements were conducted at all locations in the piezoelectric ultrasonic system equipped with ½″ and ¾″ probes. A set of heat transfer calculations were developed to estimate the convection heat losses from the reaction solution. Chemical dosimeters represented by the oxidation of potassium iodide, Fricke solution and 4-nitrophenol were used to chemically correlate the effect of various electrical litudes and treatment regimes. This allowed estimation of sonochemical-efficiency (SE) and energy conversion (XUS) of the ultrasonic system. Results of this study showed overall conversion efficiencies of 60-70%. This correlated well with the chemical dosimeter yield curves of both organic and inorganic aqueous solutions. All dosimeters showed bubble shielding and coalescence effects at higher ultrasonic power levels, less pronounced for the ½″ probe case. SE and XUS values in the range of 10(-10) mol/J and 10(-3) J/J respectively confirmed that conversion of ultrasonic power to chemical yield declined with litude.
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.ULTSONCH.2015.08.013
Abstract: To date, the successful application of large scale ultrasound in water treatment has been a challenge. Magnetostrictive ultrasound technologies for constructing a large-scale water treatment system are proposed in this study. Comprehensive energy evaluation of the proposed system was conducted. The effects of chosen waveform, scalability and reactor design on the performance of the system were explored using chemical dosimetry. Of the fundamental waveforms tested sine, triangle and square, the highest chemical yield resulted from the square wave source. Scaling up from the 0.5L bench-scale system to the 15 L large-scale unit resulted in a gain of approximately 50% in sonochemical efficiency (SE) for the system. The use of a reactor tank with 45° inclined sides further increased SE of the system by 70%. The ability of the large scale system in removing contaminants from natural water s les was also investigated. The results revealed that the large-scale unit was capable of achieving a maximum removal of microbes and dissolved organic carbon (DOC) of 35% and 5.7% respectively at a power density approximately 3.9 W/L. The results of this study suggest that magnetostrictive ultrasound technology excited with square wave has the potential to be competitive in the water treatment industry.
Publisher: Canadian Center of Science and Education
Date: 15-07-2020
DOI: 10.5539/JAS.V12N8P1
Abstract: Applying biochar (BC) to broad acre crops is an effective way to sequester carbon while improving soil fertility and reducing nutrient leaching. Adopting a similar approach in a hydroponic environment, BC may enhance nutrient availability and reduce natural fluctuations in the nutrient solution. This study monitored the effect of BC addition to peatmoss growth media with ratios of 0%, 5%, 25% and 50% on pH, electrical conductivity (EC) and macronutrient retention, over 15 days using hydroponic nutrient solution controls. Deionised water was used to measure nutrient releases in the closed loop hydroponic system, showing that biochar increased pH level in both retention and release stages. As expected, the pH increased by a maximum of 1.5 units with the highest biochar to growth media ratio due to the natural liming nature of the BC. The EC was also affected, as BC increased in the media EC reduced. With regards to retention of nutrients, BC recovered nitrate, phosphate, calcium and sulphate but did not affect magnesium. Potassium levels increased in solution with increasing BC ratio. In terms of outcomes relevant to global agriculture, the results show that the same level of production can nominally be obtained with around half the nutrient requirements.
Publisher: No publisher found
Date: 2023
Publisher: MDPI AG
Date: 24-03-2014
DOI: 10.3390/EN7031829
Publisher: Elsevier BV
Date: 02-2023
Publisher: American Speech Language Hearing Association
Date: 16-11-2022
DOI: 10.1044/2022_AJSLP-21-00396
Abstract: Access to augmentative and alternative communication (AAC) systems in languages other than English and multilingual AAC systems remains limited for many people with complex communication needs, despite a growing interest in this field, and an acknowledged need for culturally responsive AAC practice. The purpose of this scoping review was to identify published research that has reported on the development of components or whole AAC systems in languages other than English, and the linguistic and cultural factors that influenced research methods and AAC system development. Nine databases were systematically searched for published research that presented development of components or whole AAC systems in languages other than English. The Mixed Methods Appraisal Tool was used to assess the quality of studies. Charted data from studies included journal and publication date, research team, language of AAC system, aims of the study, study methodologies, study participants, and type of AAC systems developed. An analytical framework was developed to identify the cultural and linguistic factors that influenced research methods and or AAC system outcomes. A total of 22 studies were included (13 qualitative, one quantitative nonrandomized, six quantitative descriptive, and two mixed-methods studies). Overall quality of studies was high. Some qualitative studies were of lower quality due to limited analysis or interpretation of results. Linguistic factors were extensively reported in the existing literature, whereas cultural factors were rarely explicitly reported. Factors contributing to lack of reporting of cultural considerations are posited with suggestions for future research. 0.23641/asha.21482607
Publisher: IOP Publishing
Date: 18-09-2012
Publisher: Walter de Gruyter GmbH
Date: 13-07-2012
Abstract: The aim of this work is to identify the optimum process parameters of sonication, manosonication and thermosonication for deactivating E. coli ATCC 25922 in water-based suspension. The influence of ultrasonic intensity, frequency, pressure, temperature and treatment time on the efficiency of ultrasonic treatments was investigated in this study theoretically and experimentally. The theoretical part of this study involved solving the Rayleigh-Plesset equation with different parameters and evaluating their effects on the collapse pressure of a bubble with initial radius of 0.01mm. The experimental part of the work was conducted using ultrasonic horn reactor at three levels of intensities low (17.56 W/cm2), intermediate (21.49 W/cm2) and high (24.17 W/cm2) with fixed frequency. Thermosonication and manosonication experiments were conducted at the sub-lethal temperatures of E. coli 45, 50, 55 and 60°C and pressures of 2, 3 and 4 bars. The optimum treatment conditions of sonication, manosonication and thermosonication were evaluated through calculating the specific energy required to obtain 5 log reduction of E. coli in each treatment. Thermosonication treatment at 21.49W/cm2 and 45°C for 4 minutes was found to be the optimum treatment conditions to deactivate E. coli in water-based suspension.
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.ENVINT.2019.03.065
Abstract: Millions of people around the world suffer from or prone to health problems caused by high concentration of fluoride in drinking water sources. One of the environmentally friendly and cost-effective ways for removing fluoride is the use of bone char. In this review, the structural properties and binding affinity of fluoride ions from different water sources was critically discussed. The effect of experimental conditions on enhancing the adsorption capacity of fluoride ions using bone char s les was addressed. It appears that surface properties, and conditions of the bone char production such as temperature and residence time play an important role in designing the optimal fluoride removal process. The optimum temperature for fluoride removal seems to be in the range of 500-700 °C and a residence time of 2 h. Applying various equilibrium adsorption isotherms for understanding fluoride adsorption mechanism was presented. The effect of bone char modification with different elements were discussed and recommendations for a further increase in the removal efficiency was proposed. Cost of bone char production and large-scale treatment systems were also discussed based on information available from scientific and commercial sources. Challenges with existing domestic defluoridation designs were highlighted and suggestions for new conceptual designs were provided.
Publisher: Elsevier BV
Date: 11-2022
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 06-2022
Publisher: Elsevier BV
Date: 08-2015
Publisher: MDPI AG
Date: 24-04-2023
DOI: 10.3390/MEMBRANES13050456
Abstract: Membrane fouling remains a major obstacle to ultrafiltration. Due to their effectiveness and minimal energy demand, membranes have been extensively employed in water treatment. To improve the antifouling property of the PVDF membrane, a composite ultrafiltration membrane was created employing the in-situ embedment approach throughout the phase inversion process and utilizing a new 2D material, MAX phase Ti3ALC2. The membranes were described using FTIR (Fourier transform infrared spectroscopy), EDS (energy dispersive spectroscopy), CA (water contact angle), and porosity measurements. Additionally, atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS) were employed. Standard flux and rejection tests were applied to study the produced membranes’ performance. Adding Ti3ALC2 reduced composite membranes’ surface roughness and hydrophobicity compared to the pristine membrane. Porosity and membrane pore size increased with the addition up to 0.3% w/v, which decreased as the additive percentage increased. The mixed matric membrane with 0.7% w/v of Ti3ALC2 (M7) had the lowest CA. The alteration in the membranes’ properties reflected well on their performance. The membrane with the highest porosity (0.1% w/v of Ti3ALC2, M1) achieved the highest pure water and protein solution fluxes of 182.5 and 148.7. The most hydrophilic membrane (M7) recorded the highest protein rejection and flux recovery ratio of 90.6, which was much higher than that of the pristine membrane, 26.2. MAX phase Ti3ALC2 is a potential material for antifouling membrane modification because of its protein permeability, improved water permeability, and outstanding antifouling characteristics.
Publisher: Elsevier BV
Date: 06-2021
Publisher: Wiley
Date: 14-04-2022
DOI: 10.1002/NAU.24927
Abstract: This study aimed to assess, for the first time, the dynamic morphometry of pelvic floor muscles (PFM) using three‐dimensional transperineal ultrasound (3D‐TPUS) and its progression at two‐time points of gestation between women with and without gestational diabetes mellitus (GDM), and whether the PFM dysfunction is connected to GDM. The study comprised 83 consecutive pregnant women with ( n = 38) and without ( n = 45) GDM screened at 24–30 and 38–40 weeks of gestation. 3D‐TPUS and a mobility test were used to quantify PFM dynamic morphometry during maximum contraction and the Valsalva maneuver. When compared to the control group, GDM women had no significant variations in all levator hiatal dimensions at 24–30 weeks of gestation. Meanwhile, women with GDM experienced an increase in levator hiatal area (LHa) ( p 0.000) during PFM contraction and enlargement in LHa ( p 0.001) during Valsalva maneuver ( p = 0.010) at 38–40 weeks of gestation. As a result, the mobility index among GDM women had a lower value ( p = 0.000). The dynamic morphometry development of PFM in GDM women at two stages during pregnancy revealed a substantial decrease ( p = 0.000) in all LHa dimensions of contraction, distension, and mobility. Using 3D‐TPUS, we found that GDM women had a specific pattern of PFM functional changes in the third trimester of pregnancy. These initial findings revealed alterations in PFM functionality, such as decreased contractility, distensibility, or mobility. This dysfunctional PFM could contribute to the long‐term development of pelvic floor dysfunction years after a GDM pregnancy.
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 06-2022
Publisher: Elsevier BV
Date: 10-2021
Publisher: Public Library of Science (PLoS)
Date: 07-12-2020
DOI: 10.1371/JOURNAL.PONE.0241962
Abstract: There is le evidence that gestational diabetes mellitus has a direct influence on urinary incontinence and pelvic floor muscles. There are no standardized pelvic floor muscle exercise programs in the literature for the physiotherapy and differ in the type of exercise, intensity, type and duration of application, and the frequency and duration of treatment sessions. The aim of this systematic review will be to investigate that Pelvic Floor Muscle Training can prevent and/or decrease the pregnancy specific urinary incontinence in women with gestational diabetes mellitus or gestational hyperglycemia. We will perform a systematic review according to the Cochrane methodology of Randomized Controlled Trials. An overall search strategy will be developed and adapted for Embase, MEDLINE, LILACS, and CENTRAL databases, with the date of consultation until June 2020. The MeSH terms used will be "Pregnancy", "Hyperglycemia", "Diabetes Mellitus, Type 2", "Diabetes Mellitus, Type 1", "Pregnancy in Diabetics", "Diabetes, Gestational", "Urinary Incontinence", "Pelvic Floor Muscle Strength". Primary outcomes : improvement or cure of pregnancy specific urinary incontinence (which can be assessed by questionnaires, and tools such as t on test, voiding diary, urodynamic study). Secondary outcomes : improvement of pelvic floor muscle strength (pelvic floor functional assessment, perineometer, electromyography, functional ultrasonography), improved quality of life (questionnaires), presence or absence of postpartum Urinary Incontinence and adverse effects. Quality assessment by Cochrane instrument. Metanalysis if plausible, will be performed by the software Review Manager 5.3. The present study will be the first to analyze the effectiveness of pelvic floor exercises in pregnant women with Gestational Diabetes Mellitus or Hyperglycemia, who suffer from pregnancy specific urinary incontinence. Randomized Controlled Trials design will be chosen because they present the highest level of evidence. It is expected to obtain robust and conclusive evidence to support clinical practice, in addition to promoting studies on the theme and contributing to new studies. Systematic review registration: PROSPERO CRD42017065281 .
Publisher: MDPI AG
Date: 28-09-2022
DOI: 10.3390/MEMBRANES12100951
Abstract: This study reports on the impact of elevated recovery (i.e., 80%, 85%, and 90%) on the fouling and performance of air gap membrane distillation (AGMD) with real seawater and landfill leachate wastewater s les using polytetrafluoroethylene (PTFE) polymer membranes. Increasing the feed temperature from 55 °C to 65 °C improved the water flux of seawater and wastewater and shortened the operating time by 42.8% for all recoveries. The average water flux in the 80%, 85%, and 90% recovery experiments at the 65 °C feed temperature was 32%, 37.32%, and 36.7% higher than the case of 55 °C for the same recoveries. The water flux decline was more severe at a higher temperature and recovery. The highest flux decline was observed with a 90% recovery at 65 °C feed temperature, followed by an 85% recovery at 65 °C. Close examination of the foulants layer revealed that seawater formed a cake fouling layer made predominantly of metal oxides. In contrast, the landfill leachate fouling was a combination of pore blocking and cake formation, consisting mainly of carbonous and nitrogenous compounds. Physical cleaning with deionized (DI) water at 55 °C and 65 °C and chemical cleaning with hydrogen peroxide (H2O2) were investigated for their efficiency in removing membrane foulants. Analytical results revealed that seawater fouling caused membrane pore blockage while wastewater fouling formed a porous layer on the membrane surface. The results showed that membrane cleaning with hydrogen peroxide restored % of the water flux. Interestingly, the fouling factor in seawater tests was 10%, while it was 16% for the wastewater tests.
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.CHEMOSPHERE.2015.11.079
Abstract: In this study, the structural alteration to DOC for a range of ultrasound treatments was investigated with chemical fractionation and UV-vis spectroscopic measurement. Ultrasound treatments were applied in continuous and pulsed modes at power levels of 48 and 84 W for effective treatment times of 5 and 15 min. Overall results show that the ultrasound treatments tended to degrade the hydrophobic aromatic fraction, while increasing the hydrophilic fraction to a lesser extent. The highest recorded reduction of hydrophobic DOC (17.8%) was achieved with pulse treatment of 84 W for15 min, while the highest increase in the hydrophilic DOC (10.5%) was obtained with continuous treatment at 84 W and 5 min. The optimal ultrasound treatment conditions were found to be pulse mode at high power and short treatment time, causing a minimal increase in the hydrophilic fraction of 1.3% with moderate removal of the hydrophobic fraction of 15.52%. The same treatment conditions, with longer treatment time, resulted in the highest removal of SUVA254 and SUVA280 of 17.09% and 16.93, respectively. These results indicate the potential for ultrasound treatments in DOC structural alteration. The hydrophobic fraction showed strong and significant correlations with UV absorbance at 254 and 280 nm. A254/A204 also exhibited strong and significant correlations with the hydrophobic/hydrophilic ratio. The other UV ratios (A250/A365 (E2/E3) and A254/A436) had weak and insignificant correlations with the hydrophobic/hydrophilic ratio. This confirms the applicability of UV indices as a suitable surrogate method for estimating the hydrophobic/hydrophilic structure.
Publisher: Elsevier BV
Date: 02-2012
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.ENVINT.2019.03.012
Abstract: Arsenic (As) is an emerging contaminant on a global scale posing threat to environmental and human health. The relatively brief history of the applications of biochar and bone char has mapped the endeavors to remove As from water to a considerable extent. This critical review attempts to provide a comprehensive overview for the first time on the potential of bio- and bone-char in the immobilization of inorganic As in water. It seeks to offer a rational assessment of what is existing and what needs to be done in future research as an implication for As toxicity of human health risks through acute and chronic exposure to As contaminated water. Bio- and bone-char are recognized as promising alternatives to activated carbon due to their lower production and activation cost. The surface modification via chemical methods has been adopted to improve the adsorption capacity for anionic As species. Surface complexation, ion exchange, precipitation and electrostatic interactions are the main mechanisms involved in the adsorption of As onto the char surface. However, arsenic-bio-bone char interactions along with their chemical bonding for the removal of As in aqueous solution is still a subject of debate. Hence, the proposed mechanisms need to be scrutinized further using advanced analytical techniques such as synchrotron-based X-ray. Moving this technology from laboratory phase to field scale applications is an urgent necessity in order to establish a sustainable As mitigation in drinking water on a global scale.
Publisher: MDPI AG
Date: 20-05-2017
DOI: 10.3390/EN10050731
Publisher: Springer Science and Business Media LLC
Date: 05-05-2022
DOI: 10.1038/S41598-022-10801-Z
Abstract: Gestational diabetes mellitus (GDM) plus rectus abdominis muscle (RAM) myopathy predicts long-term urinary incontinence (UI). Atrophic and stiff RAM are characteristics of diabetes-induced myopathy (DiM) in pregnant rats. This study aimed to determine whether swimming exercise (SE) has a therapeutic effect in mild hyperglycemic pregnant rats model. We hypothesized that SE training might help to reverse RAM DiM. Mild hyperglycemic pregnant rats model was obtained by a unique subcutaneous injection of 100 mg/kg streptozotocin (diabetic group) or citrate buffer (non-diabetic group) on the first day of life in Wistar female newborns. At 90 days of life, the rats are mated and randomly allocated to remain sedentary or subjected to a SE protocol. The SE protocol started at gestational day 0 and consisted of 60 min/day for 6 days/week in a period of 20 days in a swim tunnel. On day 21, rats were sacrificed, and RAM was collected and studied by picrosirius red, immunohistochemistry, and transmission electron microscopy. The SE protocol increased the fiber area and diameter, and the slow-twitch and fast-twitch fiber area and diameter in the diabetic exercised group, a finding was also seen in control sedentary animals. There was a decreased type I collagen but not type III collagen area and showed a similar type I/type III ratio compared with the control sedentary group. In conclusion, SE during pregnancy reversed the RAM DiM in pregnant rats. These findings may be a potential protocol to consider in patients with RAM damage caused by GDM.
Publisher: Informa UK Limited
Date: 02-01-2015
Publisher: Elsevier BV
Date: 02-2014
Publisher: Elsevier
Date: 2022
Publisher: MDPI AG
Date: 29-09-2023
DOI: 10.3390/W15193437
Publisher: Elsevier BV
Date: 09-2012
Publisher: MDPI AG
Date: 20-03-2023
DOI: 10.3390/MEMBRANES13030357
Abstract: In this work, MXene as a hydrophilic 2D nanosheet has been suggested to tailor the polyphenylsulfone (PPSU) flat sheet membrane characteristics via bulk modification. The amount of MXene varied in the PPSU casting solution from 0–1.5 wt.%, while a series of characterization tools have been employed to detect the surface characteristics changes. This included atomic force microscopy (AFM), scanning electron microscopy (SEM), contact angle, pore size and porosity, and Fourier-transform infrared spectroscopy (FTIR). Results disclosed that the MXene content could significantly influence some of the membranes’ surface characteristics while no effect was seen on others. The optimal MXene content was found to be 0.6 wt.%, as revealed by the experimental work. The roughness parameters of the 0.6 wt.% nanocomposite membrane were notably enhanced, while greater hydrophilicity has been imparted compared to the nascent PPSU membrane. This witnessed enhancement in the surface characteristics of the nanocomposite was indeed reflected in their performance. A triple enhancement in the pure water flux was witnessed without compromising the retention of the membranes against the Cu2+, Cd2+ and Pd2+ feed. In parallel, high, and comparable separation rates ( %) were achieved by all membranes regardless of the MXene content. In addition, promising antifouling features were observed with the nanocomposite membranes, disclosing that these nanocomposite membranes could offer a promising potential to treat heavy metals-containing wastewater for various applications.
Publisher: Elsevier BV
Date: 07-2016
DOI: 10.1016/J.ULTSONCH.2015.11.028
Abstract: The application of pulsed mode ultrasound (PMU) as a pre-treatment for alum coagulation was investigated at various alum dosages and pH levels. The effects of the treatments on turbidity and dissolved organic carbon (DOC) removal and residual Al were evaluated. Response surface methodology (RSM) was utilized to optimize the operating conditions of the applied treatments. The results showed that PMU pre-treatment increased turbidity and DOC removal percentages from maximum of 96.6% and 43% to 98.8% and 52%, respectively. It also helped decrease the minimum residual Al from 0.100 to 0.094 ppm. The multiple response optimization was carried out using the desirability function. A desirability value of >0.97 estimated respective turbidity removal, DOC removal and Al residual of 89.24%, 45.66% and ∼ 0.1 ppm for coagulation (control) and 90.61%, >55% and ∼ 0 for coagulation preceded by PMU. These figures were validated via confirmatory experiments. PMU pre-treatment increased total coliform removal from 80% to >98% and decreased trihalomethane formation potential (THMFP) from 250 to 200 ppb CH3Cl. Additionally, PMU application prior to coagulation improved the settleability of sludge due to the degassing effects. The results of this study confirms that PMU pre-treatment can significantly improve coagulation performance.
Publisher: Elsevier
Date: 2023
Publisher: Elsevier BV
Date: 04-2021
Publisher: MDPI AG
Date: 08-08-2019
DOI: 10.3390/C5030047
Abstract: Agricultural runoff is a major cause of degradation to freshwater sources. Nitrate is of particular interest, due to the abundant use of nitrogen-based fertilizers in agricultural practices globally. This study investigated the nitrate removal of biochar produced from an agricultural waste product, macadamia nutshell (MBC). Kinetic experiments and structural analyses showed that MBC pyrolsed at 900 °C exhibited inferior NO3− removal compared to that pyrolsed at 1000 °C, which was subsequently used in the column experiments. Concentrations of 5, 10 and 15 mg/L, with flowrates of 2, 5 and 10 mL/min, were examined over a 360 min treatment time. Detailed statistical analyses were applied using 23 factorial design. Nitrate removal was significantly affected by flowrate, concentration and their interactions. The highest nitrate removal capacity of 0.11 mg/g MBC was achieved at a NO3− concentration of 15 mg/L and flowrate of 2 mL/min. The more crystalline structure and rough texture of MBC prepared at 1000 °C resulted in higher NO3− removal compared to MBC prepared at 900 °C. The operating parameters with the highest NO3− removal were used to study the removal capacity of the column. Breakthrough and exhaustion times of the column were 25 and 330 min respectively. Approximately 92% of the column bed was saturated after exhaustion.
Publisher: MDPI AG
Date: 22-12-2022
DOI: 10.3390/MEMBRANES13010015
Abstract: The concerns regarding the reactive nitrogen levels exceeding the planetary limits are well documented in the literature. A large portion of anthropogenic nitrogen ends in wastewater. Nitrogen removal in typical wastewater treatment processes consumes a considerable amount of energy. Nitrogen recovery can help in saving energy and meeting the regulatory discharge limits. This has motivated researchers and industry professionals alike to devise effective nitrogen recovery systems. Membrane technologies form a fundamental part of these systems. This work presents a thorough overview of the subject using scientometric analysis and presents an evaluation of membrane technologies guided by literature findings. The focus of nitrogen recovery research has shifted over time from nutrient concentration to the production of marketable products using improved membrane materials and designs. A practical approach for selecting hybrid systems based on the recovery goals has been proposed. A comparison between membrane technologies in terms of energy requirements, recovery efficiency, and process scale showed that gas permeable membrane (GPM) and its combination with other technologies are the most promising recovery techniques and they merit further industry attention and investment. Recommendations for potential future search trends based on industry and end users’ needs have also been proposed.
Publisher: Elsevier BV
Date: 12-2022
Publisher: Elsevier BV
Date: 12-2022
Publisher: Elsevier BV
Date: 03-2021
Publisher: Informa UK Limited
Date: 18-08-2015
Publisher: Elsevier BV
Date: 06-2023
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.SCITOTENV.2015.09.143
Abstract: The application of pulsed ultrasound for DOC removal from natural water s les has been thoroughly investigated in this work. Natural water s les were treated with ultrasound at power levels of 48 and 84 W with treatment times of 5 and 15 min. Chemical fractionation was conducted for both untreated and treated s les to clearly identify the change in DOC structure caused by ultrasonic treatments. Statistical analyses applying 2(3) factorial design were performed to study the behaviour of the response (i.e. DOC removal) under different operating conditions. Overall, ultrasonic treatments resulted in DOC removal of 7-15% depending on the applied operating conditions. The treated water had high microbial loading that interfered with DOC removal due primarily to the release of microbial products when exposed to ultrasound. Pulse ultrasound was found to be more effective than the continuous mode for DOC removal at the same effective power level. A regression model was developed and tested for DOC removal prediction. The model was adequate in predicting DOC removal with a maximum deviation from the experimental data of <11%. Pulsed ultrasound at low power levels and short treatment times was found to be the most energy efficient treatment for DOC removal.
Publisher: Desalination Publications
Date: 2018
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.SCITOTENV.2022.156014
Abstract: Despite water being critical for human survival, its uneven distribution, and exposure to countless sources of pollution make water shortages increasingly urgent. Membrane technology offers an efficient solution for alleviating the water shortage impact. The selectivity and permeability of membranes can be improved by incorporating additives of different nature and size scales. However, with the vast debate about the environmental and economic feasibility of the common nanoscale materials in water treatment applications, we can infer that there is a long way before the first industrial nanocomposite membrane is commercialized. This stumbling block has motivated the scientific community to search for alternative modification routes and/or materials with sustainable features. Herein, we present a pragmatic review merging the concept of sustainability, nanotechnology, and membrane technology through the application of natural additives (e.g., Clays, Arabic Gum, zeolite, lignin, Aquaporin), recycled additives (e.g., Biochar, fly ash), and recycled waste (e.g., Polyethylene Terephthalate, recycled polystyrene) for polymeric membrane synthesis and modification. Imparted features on polymeric membranes, induced by the presence of sustainable natural and waste-based materials, are scrutinized. In addition, the strategies harnessed to eliminate the hurdles associated with the application of these nano and micro size additives for composite membranes modification are elaborated. The expanding research efforts devoted recently to membrane sustainability and the prospects for these materials are discussed. The findings of the investigations reported in this work indicate that the application of natural and waste-based additives for composite membrane fabrication/modification is a nascent research area that deserves the attention of both research and industry.
Publisher: Elsevier BV
Date: 07-2023
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.ULTSONCH.2019.104816
Abstract: Air Gap Membrane distillation (AGMD) is a thermally driven separation process capable of treating challenging water types, but its low productivity is a major drawback. Membrane fouling is a common problem in many membrane treatment systems, which exacerbates AGMD's low overall productivity. In this study, we investigated the direct application of low-power ultrasound (8-23 W), as an in-line cleaning and performance boosting technique for AGMD. Two different highly saline feedwaters, namely natural groundwater (3970 μS/cm) and RO reject stream water (12760 μS/cm) were treated using Polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) membranes. Theoretical calculations and experimental investigations are presented, showing that the applied ultrasonic power range only produced acoustic streaming effects that enhanced cleaning and mass transfer. Attenuated Total Reflection Fourier-Transform Infrared Spectroscopy (ATR FT-IR) analysis showed that ultrasound was capable of effectively removing silica and calcium scaling. Ultrasound application on a fouled membrane resulted in a 100% increase in the permeate flux. Cleaning effects accounted for around 30-50% of this increase and the remainder was attributed to mass transfer improvements. Contaminant rejection percentages were consistently high for all treatments (>99%), indicating that ultrasound did not deteriorate the membrane structure. Scanning Electron Microscopy (SEM) analysis of the membrane surface was used to confirm this observation. The images of the membrane surface demonstrated that ultrasound successfully cleaned the previously fouled membrane, with no signs of structural damage. The results of this study highlight the efficient and effective application of direct low power ultrasound for improving AGMD performance.
No related grants have been discovered for Raed Al-juboori.