ORCID Profile
0000-0001-9752-9127
Current Organisations
University of South Australia
,
Universiti Teknologi MARA
,
Universiti Kebangsaan Malaysia
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Publisher: Springer Science and Business Media LLC
Date: 20-11-2013
Publisher: UiTM Press, Universiti Teknologi MARA
Date: 25-08-2020
Abstract: Oil palm plantations produce palm kernel shell (PKS) that can be converted into biochar for environment-friendly soil remediation and water treatment. Oxidation with hydrogen peroxide (H2O2) may enhance surface characteristics and the quality of low-rank PKS biochar as a sorbent for environmental decontamination. This study aims to determine the effect of oxidation on the surface characteristics (i.e., specific surface area, surface charge, and chemical properties) of PKS biochar, and compared with that of PKS activated carbon. The surface area for the oxidised PKS biochar was similar to that of PKS biochar, indicating that oxidation did not remove the pore blocking material from the surface area of the PKS biochar. However, oxidation has increased the amount of negatively charged oxygen functional groups in PKS biochar, as indicated by the analyses of the Fourier transform infrared spectroscopy (FTIR) and cation exchange capacity (CEC). The CEC value of raw and activated PKS biochar were similar and 4.6 and 2.6 times lower for PKS biochar and oxidised PKS biochar, respectively. Oxidation caused enlargement of pores on PKS biochar and caused a reduction of specific surface area. More research is required to establish the process conditions to create a greater surface area and sorption capacity.
Publisher: Science Publishing Corporation
Date: 21-07-2018
DOI: 10.14419/IJET.V7I3.11.15966
Abstract: Biochar has an alkaline and porous structure that could be a potential material for recycling phosphorous (P) from urine. Sawdust (SD) was pyrolyzed to produce sawdust biochar (SDB), and then impregnated with magnesium (Mg) to produce Mg-impregnated biochar (SDBM). Artificial human urine (AHU) solution was used for a batch sorption study, and various sorption parameters (i.e., sorbent/solution ratio, pH of AHU, and initial total P concentration of AHU) were optimized. The concentration of total P was measured using an inductively coupled plasma-optical emission spectroscopy (ICP-OES). The surface morphology and elemental analysis for SDB, SDBM and the struvite-loaded SDBM (SMSDB) were investigated using scanning electron spectroscopy-energy dispersive x-ray spectroscopy (SEM-EDX). The total P sorption capacity for SDBM (32755 mg/g) was higher than that of SDB (7782 mg/g) and SD (10682 mg/g). The optimum total P removal for SDBM (21.2%) was achieved at a sorbent/solution ratio of 0.06g/L at pH 9. Sorption of total P may have occurred on the heterogeneous surface of SDBM. The presence of struvite crystals indicates that phosphate was adsorbed and then precipitated on the surface of SDBM.
Publisher: African Journals Online (AJOL)
Date: 02-2018
Publisher: African Journals Online (AJOL)
Date: 02-2018
Publisher: Elsevier BV
Date: 12-2023
Publisher: Oxford University Press (OUP)
Date: 23-08-2016
DOI: 10.1093/HMG/DDW264
Publisher: Informa UK Limited
Date: 27-04-2023
Publisher: Science Publishing Corporation
Date: 21-07-2018
DOI: 10.14419/IJET.V7I3.11.16017
Abstract: Cocoa pod husk (CPH) was pyrolyzed at 500°C to produce biochar (CPHB) for sorption of lead (Pb) from aqueous system. Chemical characterization for CPHB was conducted using Fourier transform infrared (FTIR) spectroscopy, Boehm titration and X-ray fluorescence (XRF) spectroscopy. Sorption parameters for CPHB (i.e., sorbent dosage, pH, contact time, and Pb concentration) were optimized. Elemental compositions for CPHB are C (66% w/w), O (19% w/w), and N (2% w/w). The ash of CPHB consists of calcium oxide (CaO) (4.6% w/w) and potassium oxide (K2O) (4.2% w/w), with negligible amount of heavy metals (1% w/w). Upon treatment with artificial Pb wastewater, FTIR spectra for CPHB revealed shifting of nasymm(COO-) and nsymm(COO-) bands from 1560 cm-1 to 1575 cm-1 and 1416 cm-1 to 1398 cm-1, respectively. The optimum sorption parameters were determined (i.e., sorbent dosage: 1.0 g/L pH 5 input Pb concentration 50 mg/L and sorption time: 210 minutes). Sorption of Pb by CPHB was best described by pseudo-second-order kinetic model (R2= 0.835), and Langmuir isotherm model (R2= 0.962). Maximum Langmuir Pb sorption capacity for CPHB (qmax) was 69.9 mg/g. These findings suggested that the sorption of Pb by CPHB may have occurred through (1) coordination with polar groups (i.e., carboxylate and phenolate) and (2) precipitation with alkaline materials (i.e., CaO and K2O).
Publisher: Malaysian Institute of Chemistry
Date: 09-03-2023
Publisher: Malaysian Institute of Chemistry
Date: 29-06-2023
Publisher: IEEE
Date: 12-2010
Publisher: African Journals Online (AJOL)
Date: 02-2018
DOI: 10.4314/JFAS.V9I6S.8
Publisher: IEEE
Date: 12-2010
Publisher: Malaysian Society of Parasitology and Tropical Medicine
Date: 30-12-2020
Publisher: Elsevier BV
Date: 09-2020
Publisher: American Society of Tropical Medicine and Hygiene
Date: 05-10-2016
Publisher: MDPI AG
Date: 31-05-2023
DOI: 10.3390/NU15112579
Abstract: Background: People with polycystic ovary syndrome (PCOS) have higher weight gain and psychological distress compared to those without PCOS. While COVID-19 restrictions led to population level adverse changes in lifestyle, weight gain and psychological distress, their impact on people with PCOS is unclear. The aim of this study was to investigate the impact the 2020 COVID-19 restrictions had on weight, physical activity, diet and psychological distress for Australians with PCOS. Methods: Australian reproductive-aged women participated in an online survey with assessment of weight, physical activity, diet and psychological distress. Multivariable logistic and linear regression were used to examine associations between PCOS and residential location with health outcomes. Results: On adjusted analysis, those with PCOS gained more weight (2.9% 95% CI 0.027–3.020 p = 0.046), were less likely to meet physical activity recommendations (OR 0.50 95% CI 0.32–0.79 p = 0.003) and had higher sugar-sweetened beverage intake (OR 1.74 95% CI 1.10–2.75 p = 0.019) but no differences in psychological distress compared to women without PCOS. Conclusions: People with PCOS were more adversely affected by COVID-19 restrictions, which may worsen their clinical features and disease burden. Additional health care support may be necessary to assist people with PCOS to meet dietary and physical activity recommendations.
Publisher: IOP Publishing
Date: 05-2021
DOI: 10.1088/1755-1315/757/1/012048
Abstract: Poor soil drainage of the lateritic soil is due to its clayey texture and high bulk density. Palm oil mill effluent (POME) may be administrated to increase the water infiltration rate and improve the drainage of the lateritic soil. The share farm of the Faculty of Plantation and Agrotechnology, UiTM Jasin was treated with various volume of POME for 16 weeks by using Completely Randomized Design (CRD). Overall, treatment of POME did not increased water infiltration rate. The bulk density of the lateritic soil that was treated with POME is suitable for agriculture. Treatment 1 (2L) gave 68 mm/hour of water infiltration rate and 1.25 g/cm 3 of bulk density with 0.570 and 0.451 of p-values respectively which is acceptable with the consideration of cost benefits, cost inputs, and profit to the industry. The results shown were not significant might be due to types and soil textures, duration for the research to be completed, and also climate change factors.
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 11-10-2016
Publisher: Elsevier BV
Date: 2023
Publisher: Springer International Publishing
Date: 11-10-2015
DOI: 10.1007/978-3-319-10479-9_1
Abstract: Chitosan originates from the seafood processing industry and is one of the most abundant of bio-waste materials. Chitosan is a by-product of the alkaline deacetylation process of chitin. Chemically, chitosan is a polysaccharide that is soluble in acidic solution and precipitates at higher pHs. It has great potential for certain environmental applications, such as remediation of organic and inorganic contaminants, including toxic metals and dyes in soil, sediment and water, and development of contaminant sensors. Traditionally, seafood waste has been the primary source of chitin. More recently, alternative sources have emerged such as fungal mycelium, mushroom and krill wastes, and these new sources of chitin and chitosan may overcome seasonal supply limitations that have existed. The production of chitosan from the above-mentioned waste streams not only reduces waste volume, but alleviates pressure on landfills to which the waste would otherwise go. Chitosan production involves four major steps, viz., deproteination, demineralization, bleaching and deacetylation. These four processes require excessive usage of strong alkali at different stages, and drives chitosan's production cost up, potentially making the application of high-grade chitosan for commercial remediation untenable. Alternate chitosan processing techniques, such as microbial or enzymatic processes, may become more cost-effective due to lower energy consumption and waste generation. Chitosan has proved to be versatile for so many environmental applications, because it possesses certain key functional groups, including - OH and -NH2 . However, the efficacy of chitosan is diminished at low pH because of its increased solubility and instability. These deficiencies can be overcome by modifying chitosan's structure via crosslinking. Such modification not only enhances the structural stability of chitosan under low pH conditions, but also improves its physicochemical characteristics, such as porosity, hydraulic conductivity, permeability, surface area and sorption capacity. Crosslinked chitosan is an excellent sorbent for trace metals especially because of the high flexibility of its structural stability. Sorption of trace metals by chitosan is selective and independent of the size and hardness of metal ions, or the physical form of chitosan (e.g., film, powder and solution). Both -OH and -NH2 groups in chitosan provide vital binding sites for complexing metal cations. At low pH, -NH3 + groups attract and coagulate negatively charged contaminants such as metal oxyanions, humic acids and dye molecules. Grafting certain functional molecules into the chitin structure improves sorption capacity and selectivity for remediating specific metal ions. For ex le, introducing sulfur and nitrogen donor ligands to chitosan alters the sorption preference for metals. Low molecular weight chitosan derivatives have been used to remediate metal contaminated soil and sediments. They have also been applied in permeable reactive barriers to remediate metals in soil and groundwater. Both chitosan and modified chitosan have been used to phytoremediate metals however, the mechanisms by which they assist in mobilizing metals are not yet well understood. In addition, microbes have been used in combination with chitosan to remediate metals (e.g., Cu and Zn) in contaminated soils. Chitosan has also been used to remediate organic contaminants, such as oil-based wastewater, dyes, tannins, humic acids, phenols, bisphenoi-A, p-benzoquinone, organo-phosphorus insecticides, among others. Chitosan has also been utilized to develop optical and electrochemical sensors for in-situ detection of trace contaminants. In sensor technology, naturally-derived chitosan is used primarily as an immobilizing agent that results from its enzyme compatibility, and stabilizing effect on nanoparticles. Contaminant-sensing agents, such as enzymes, microbes and nanoparticles, have been homogeneously immobilized in chitosan gels by using coagulating (e.g., alginate, phosphate) or crosslinking agents (e.g., GA, ECH). Such immobilization maintains the stability of sensing elements in the chitosan gel phase, and prevents inactivation and loss of the sensing agent. In this review, we have shown that chitosan, an efficient by-product of a waste biomaterial, has great potential for many environmental applications. With certain limitations, chitosan and its derivatives can be used for remediating contaminated soil and wastewater. Notwithstanding, further research is needed to enhance the physicochemical properties of chitosan and mitigate its deficiencies.
Publisher: IWA Publishing
Date: 12-2011
DOI: 10.2166/WST.2011.805
Abstract: The potential of Pleurotus ostreatus spent mushroom compost (PSMC) as a green biosorbent for nickel (II) biosorption was investigated in this study. A novel approach of using the half-saturation concentration of biosorbent to rapidly determine the uptake, kinetics and mechanism of biosorption was employed together with cost per unit uptake analysis to determine the potential of this biosorbent. Fifty per cent nickel (II) biosorption was obtained at a half-saturation constant of 0.7 g biosorbent concentration, initial pH in the range of 4–8, 10 min contact time, 50 mL 50 mg/L nickel (II) initial concentration. The experimental data were well fitted with the Langmuir isotherm model and the maximum nickel (II) biosorption was 3.04 mg/g. The results corresponded well to a second pseudo order kinetic model with the coefficient of determination value of 0.9999. Based on FTIR analysis, the general alkyl, hydroxyl or amino, aliphatic alcohol and carbonyl functional groups of biosorbent were involved in the biosorption process. Therefore, biosorption of nickel (II) must involve several mechanisms simultaneously such as physical adsorption, chemisorption and ion exchange. Cost comparison for PSMC with Amberlite IRC-86 ion exchange resin indicates that the biosorbent has the potential to be developed into a cost effective and environmentally friendly treatment system.
Publisher: Springer Science and Business Media LLC
Date: 04-11-2016
DOI: 10.1007/S11356-015-5654-5
Abstract: Pristine chitosan beads were modified with sulfur (S)-containing functional groups to produce thiolated chitosan beads (ETB), thereby increasing S donor ligands and crosslinks. The effect of temperature, heating time, carbon disulfide (CS2)/chitosan ratio, and pH on total S content of ETB was examined using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The total S content of ETB increased with increasing CS2/chitosan ratio and decreased with decreasing pH and increasing temperature (>60 °C) and heating time (at 60 °C). Spectroscopic analyses revealed the presence of thiol (-SH)/thione, disulfide (-S-S-), and sulfonate groups in ETB. The thiolation mechanism involves decomposition of dithiocarbamate groups, thereby forming thiourea crosslinks and trithiocarbonate, resulting in -SH oxidation to produce -S-S- crosslinks. The partially formed ETB crosslinks contribute to its acid stability and are thermodynamically feasible in adsorbing Cd and Cu. The S-containing functional groups added to chitinous wastes act as sorbents for metal remediation from acidic environments.
Publisher: Informa UK Limited
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 16-02-2011
Publisher: Elsevier BV
Date: 08-2023
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/SR18279
Abstract: Changes in soil nutrients have been applied in legal investigations of the time of death or to locate a clandestine grave. However, research on forensic soil chemistry under the tropical climate conditions in Malaysia is at its infancy, with few data available for forensic investigations. This study aims to study changes of soil nutrients (i.e. ammonia, phosphate and nitrate) as well as soil pH and electrical conductivity (EC), and the associated stages of decomposition of rat carcasses (n = 3) under controlled tropical climate conditions. The results showed differences in soil pH between control and carcass soils. Soil EC and concentrations of ammonia and phosphate increased during early decomposition stages, and declined thereafter. Nitrate concentration increased at the later stage of decomposition. We also found that the top layer of soil (i.e. 5 cm from surface) rendered a significant pattern of soil nutrient dynamics compared with soil at 10 cm from the surface, possibly due to a slower rate of vertical transfer and the washing-off effect. We suggest that the soil EC value and changes of soil nutrients in the top 5 cm of the soil layer have potential in forensic investigation to determine the minimum post-mortem interval and serve as an indicator for hidden graves and cadaver decomposition islands.
Start Date: 2009
End Date: 2013
Funder: Universiti Teknologi MARA
View Funded ActivityStart Date: 2016
End Date: 2019
Funder: Ministry of Higher Education
View Funded ActivityStart Date: 2015
End Date: 2017
Funder: Ministry of Higher Education, Malaysia
View Funded Activity