Zurina Zainal Abidin

Putra University, Malaysia, Putrajaya, Putrajaya, Malaysia

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Publications (9)17.95 Total impact

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    ABSTRACT: In this work, crude oil biodegradation has been optimized in a solid-liquid two phase partitioning bioreactor (TPPB) by applying a response surface methodology (RSM) based D-optimal design. Three key factors including phase ratio, substrate concentration in solid organic phase, and sodium chloride (NaCl) concentration in aqueous phase were taken as independent variables, while the efficiency of the biodegradation of absorbed crude oil on polymer beads was considered to be the dependent variable. Commercial thermoplastic polyurethane (Desmopan®) was used as the solid phase in the TPPB. The designed experiments were carried out batch wise using a mixed acclimatized bacterial consortium. Optimum combinations of key factors with a statistically significant cubic model were used to maximize biodegradation in the TPPB. The validity of the model was successfully verified by the good agreement between the model-predicted and experimental results. When applying the optimum parameters, gas chromatography-mass spectrometry (GC-MS) showed a significant reduction in n-alkanes and low molecular weight polycyclic aromatic hydrocarbons (PAHs). This consequently highlights the practical applicability of TPPB in crude oil biodegradation. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 2014.
    Biotechnology Progress 04/2014; · 1.85 Impact Factor
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    ABSTRACT: This study aims to investigate the influence of different stirring time for synthesis of silver nanoparticles in glutathione (GSH) aqueous solution. The silver nanoparticles (Ag-NPs) were prepared by green synthesis method using GSH as reducing agent and stabilizer, under moderate temperature at different stirring times. Silver nitrate (AgNO3) was taken as the metal precursor while Ag-NPs were prepared in the over reaction time. Formation of Ag-NPs was determined by UV-vis spectroscopy where surface plasmon absorption maxima can be observed at 344-354 nm from the UV-vis spectrum. The synthesized nanoparticles were also characterized by X-ray diffraction (XRD). The peaks in the XRD pattern confirmed that the Ag-NPs possessed a face-centered cubic and peaks of contaminated crystalline phases were unable to be located. Transmission electron microscopy (TEM) revealed that Ag-NPs synthesized were in spherical shape. Zeta potential results indicate that the stability of the Ag-NPs is increases at the 72 h stirring time of reaction comparison to GSH. The Fourier transform infrared (FT-IR) spectrum suggested the complexation present between GSH and Ag-NPs. The use of green chemistry reagents, such as peptide, provides green and economic features to this work. Ag-NPs were successfully synthesized in GSH aqueous solution under moderate temperature at different stirring times. The study clearly showed that the Ag-NPs synthesized in the long times of stirring, thus, the kinetic of GSH reaction is very slow. TEM results shows that with the increase of stirring times the mean particle size of Ag-NPs become increases. The FT-IR spectrum suggested the complexation present between GSH and Ag-NPs. These suggest that Ag-NPs can be employed as an effective bacteria inhibitor and can be applied in medical field.
    Chemistry Central Journal 02/2014; 8(1):11. · 1.31 Impact Factor
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    ABSTRACT: Abstract Soil contamination by crude oil is a major environmental and health hazard. Extraction of the total petroleum hydrocarbons (TPH) sorbed to the clay soil (kaolin) was carried out using synthetic sorbent (Desmopan®) and 2-propanol as a mobilizing agent. The crude oil-loaded polymer beads were bioregenerated in a solid–liquid two-phase partitioning bioreactor (TPPB). A central composite design under response surface methodology was employed for the experimental design and analysis of the results. The independent variables were extraction phase to soil ratio, mobilizing agent to soil ratio, and initial concentration of crude oil in polluted soil. The influences of three independent variables on the TPH reduction efficiency were determined using a statistically significant quadratic model (R 2 = 0.9673). Remediation was more efficient when the mobilizing agent to the soil ratio was equal to 3.00 ml g−1, compared to the higher (4.00 ml g−1) and lower (2.00 ml g−1) levels. The results exhibited that the interaction between the extraction phase ratio and the initial concentration of crude oil in kaolin had significantly influenced the TPH removal. The bioregeneration studies showed a significant reduction (72.07 ± 0.63 %) of low-molecular-weight (two- to three-ring) polycyclic aromatic hydrocarbons and n-alkanes (97.75 ± 0.26 %) present in the crude oil-loaded solid polymers within a 10-day experiment. These findings show that solid polymer extraction followed by bioregeneration of sorbents in a TPPB is applicable to treat crude oil-contaminated kaolin.
    Water Air and Soil Pollution 03/2013; · 1.75 Impact Factor
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    ABSTRACT: Produced water is a significant waste stream generated in association with oil and gas production. It contains high concentrations of hydrocarbon constituents and different salts. In this study, a membrane sequencing batch reactor (MSBR) was used to treat synthetic and real produced water. The MSBR was evaluated in terms of biodegradation of hydrocarbons in the synthetic produced water with various organic loading rates (OLR) (0.281, 0.563, 1.124, 2.248, and 3.372kg COD/(m3day)), cycle time (12, 24, and 48h), and membrane performance. The effects of salt concentrations at different total dissolved solids (TDS) (35,000, 50,000, 100,000, 150,000, 200,000, and 250,000mg/L) on biological treatment of the pollutants in the synthetic and real wastewater were studied. At an OLR of 1.124kg COD/(m3day), an HRT of 48h and TDS of 35,000mg/L, removal efficiencies of 97.5%, 97.2%, and 98.9% of COD, total organic carbon (TOC), and oil and grease (O&G), respectively were achieved. For the real produced water, removal rates of 86.2%, 90.8%, and 90% were obtained for the same conditions. However, with increasing salt content, the COD-removal efficiencies of the synthetic and real produced water were reduced to 90.4% and 17.7%, respectively at the highest TDS.
    Process Safety and Environmental Protection - PROCESS SAF ENVIRON PROT. 01/2012;
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    ABSTRACT: A membrane sequencing batch reactor (MSBR) treating hypersaline oily wastewater was modeled by artificial neural network (ANN). The MSBR operated at different total dissolved solids (TDSs) (35,000; 50,000; 100,000; 150,000; 200,000; 250,000mg/L), various organic loading rates (OLRs) (0.281, 0.563, 1.124, 2.248, and 3.372kg COD/(m(3)day)) and cyclic time (12, 24, and 48h). A feed-forward neural network trained by batch back propagation algorithm was employed to model the MSBR. A set of 193 operational data from the wastewater treatment with the MSBR was used to train the network. The training, validating and testing procedures for the effluent COD, total organic carbon (TOC) and oil and grease (O&G) concentrations were successful and a good correlation was observed between the measured and predicted values. The results showed that at OLR of 2.44kg COD/(m(3)day), TDS of 78,000mg/L and reaction time (RT) of 40h, the average removal rate of COD was 98%. In these conditions, the average effluent COD concentration was less than 100mg/L and met the discharge limits.
    Journal of hazardous materials 05/2011; 192(2):568-75. · 4.14 Impact Factor
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    ABSTRACT: This study focused on the characterization of fouling cake layer during operation of a membrane bioreactor system employed for the treatment of synthetic hypersaline oily wastewater. Also the effects of ultrasound and addition of four types of flocculants (aluminium sulfate, Chitosan, ferric chloride, polyaluminium chloride) on mitigation of membrane fouling were studied. The components of the foulants were examined by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray (EDX) analysis, inductively coupled plasma (ICP) and particle size analyzer (PSA). The FTIR demonstrated that membrane fouling layer is governed by the deposition of organic and inorganic substances composed of extracellular polymeric substances (EPS) (proteins, polysaccharides, etc.), hydrocarbon components and inorganic matters. The AFM images of the fouled membrane confirmed the idea of surface coverage as a fouling mechanism. The SEM analysis showed that rod-shape bacterial clusters were one of the contributors to membrane cake layer. The EDX and ICP results showed that Mg, Al, Ca, Na, K and Fe were the major metal elements in the fouling cake. The PSA results indicate that membrane foulants had a much smaller size than mixed liquor suspensions in the MSBR. Fouling mitigation experiments showed that the effect of organic flocculant was more than inorganic chemicals but the overall effects were not significant. Ultrasound could effectively remove the fouling cake from the membrane surface and thus recovered the membrane permeation flux for a long time.
    Chemical Engineering Journal. 01/2011; 168(1):140-150.
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    ABSTRACT: Oil and gas field wastewater or produced water is a significant waste stream in the oil and gas industries. In this study, the performance of a membrane sequencing batch reactor (MSBR) and membrane sequencing batch reactor/reverse osmosis (MSBR/RO) process treating produced wastewater were investigated and compared. The MSBR was operated in different hydraulic residence time (HRT) of 8, 20 and 44 h. Operation results showed that for a HRT of 20 h, the combined process effluent chemical oxygen demand (COD), total organic carbon (TOC) and oil and grease (O&G) removal efficiencies were 90.9%, 92% and 91.5%, respectively. The MSBR effluent concentration levels met the required standard for oil well re-injection. The RO treatment reduced the salt and organic contents to acceptable levels for irrigation and different industrial re-use. Foulant biopsy demonstrated that the fouling on the membrane surface was mainly due to inorganic (salts) and organic (microorganisms and their products, hydrocarbon constituents) matters.
    Bioresource Technology 09/2010; 101(18):6942-9. · 4.75 Impact Factor
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    ABSTRACT: Produced water is the largest waste stream generated in oil and gas industries. It is a mixture of different organic and inorganic compounds. Due to the increasing volume of waste all over the world in the current decade, the outcome and effect of discharging produced water on the environment has lately become a significant issue of environmental concern. Produced water is conventionally treated through different physical, chemical, and biological methods. In offshore platforms because of space constraints, compact physical and chemical systems are used. However, current technologies cannot remove small-suspended oil particles and dissolved elements. Besides, many chemical treatments, whose initial and/or running cost are high and produce hazardous sludge. In onshore facilities, biological pretreatment of oily wastewater can be a cost-effective and environmental friendly method. As high salt concentration and variations of influent characteristics have direct influence on the turbidity of the effluent, it is appropriate to incorporate a physical treatment, e.g., membrane to refine the final effluent. For these reasons, major research efforts in the future could focus on the optimization of current technologies and use of combined physico-chemical and/or biological treatment of produced water in order to comply with reuse and discharge limits.
    Journal of hazardous materials 06/2009; 170(2-3):530-51. · 4.14 Impact Factor
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    ABSTRACT: An adsorbent (H-KFC) was prepared from kenaf fibre char by acid treatment using HCl (3 M). The treatment caused an increase in the BET surface area and as a result there was an increase in the adsorption of Methylene blue dye (MB) in batch system studies. The adsorption process was investigated by varying the initial dye concentration, adsorbent dose, pH and temperature. The highest percentage removal of Methylene blue dye (MB) was found to be 95 wt% at a concentration of 50 mg/L. At a pH of 8.5, the sorption of dye was favourable. The equilibrium data was analysed using the Langmuir, Freundlich and Temkin isotherm models. It was found that the equilibrium data was best represented by the Langmuir isotherm model. The kinetic data obtained was analysed using a pseudo-first-order and pseudo-second-order equation. The experimental data fitted well the pseudo-second-order kinetic model. The intraparticle diffusion model showed three steps where intraparticle diffusion was not the only rate controlling step of the adsorption process. Thermodynamic studies indicated that the adsorption was endothermic, increasing in randomness of adsorbed species and spontaneous at high temperatures.
    Chemical Engineering Journal. s 181–182:449–457.