Personal Research Database

174 (1-3), 144-150.

Full Text: 2010\J Haz Mat174, 144.pdf

Abstract: Grape stalk wastes generated in the wine production process were used for the removal of nickel (II) from aqueous solution. The experimental breakthrough curves were obtained in fixed-bed columns. Experiments we carry out in order to evaluate the influence of inlet metal concentration (30 and 70 mg L-1) and the regeneration process in a double sorption cycle. The CXTFIT code was used to fit the experimental data and to determine the transport and sorption parameters of the convective-dispersive equation (CDE) and the two-site deterministic non-equilibrium (TSM/CDE) model by adjusting the models to the experimental breakthrough curves (BTC). The results showed that bed capacity as well as transport and sorption parameters were affected by the initial metal concentration, at the highest Ni(II) concentration the grape stalks column saturated quickly leading to earlier breakthrough. The sorption capacity of the sorbent was slightly reduced in a double sorption cycle, while the recovery of the metal in the desorption step was ranging between 80% and 85% in both cycles. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Aqueous Solutions, Biosorption, Breakthrough, Breakthrough Curves, Copper, Desorption, Equilibrium Uptake, Grape Stalk, Grape Stalks Wastes, Heavy-Metals, Modelling, Nickel, Nickel, Production, Regeneration, Removal, Sorbent, Sorption, Sorption Dynamics, Transport, Two-Site Non-Equilibrium Model, Wastewaters

? Kiser, J.R. and Manning, B.A. (2010), Reduction and immobilization of chromium(VI) by iron(II)-treated faujasite. Journal of Hazardous Materials, 174 (1-3), 167-174.

Full Text: 2010\J Haz Mat174, 167.pdf

Abstract: Removal of hexavalent chromium (Cr(VI)) from wastewater typically involves reduction of Cr(VI) to insoluble Cr(III) using zerovalent iron (Fe-0) or ferrous iron (Fe(II)). This study investigates the effectiveness of Fe(II)-treated faujasite (zeolite Fe(II)-Y) for reduction of Cr(VI) and immobilization (adsorption/co-precipitation) of the Cr(III) reaction product. The Fe(II)-faujasite material effectively removed high concentrations of dissolved Cr(VI) from aqueous solution resulting in Cr solid loadings as high as 0.30 mmol Cr per grain Fe(II)-faujasite or similar to 1.5% Cr (w:w). Results of Cr K-edge X-ray absorption near edge spectroscopy (XANES) confirmed that the oxidation state of Cr in Cr(VI)-treated Fe(II)-faujasite was Cr(III). The local atomic structure of Cr was investigated by extended X-ray absorption fine structure (EXAFS) spectroscopy and the structure of Cr in the product was described by a Cr-O first shell of six O atoms at 1.98(+/- 0.02) angstrom plus a second atomic shell of metal (Cr, Fe) at 3.13(+/- 0.02) angstrom. The EXAFS results, combined with SEM imaging and X-ray diffraction analyses, suggested that the product of the reaction of Cr(VI) with Fe(II)-faujasite is primarily a poorly order CrxFe1-x(OH)(3) mixed phase similar to previous investigations of the reaction of Cr(VI) with Fe-0 and not solely Cr(III) bound directly to zeolite cation exchange sites. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Aqueous-Solutions, Cation Exchange, Chromate Reduction, Chromium, Chromium(III) Iron, Chromium(VI), Coal Fly-Ash, Cr(VI), Exafs, Faujasite, Hexavalent Chromium, Ion-Exchange, Natural Clinoptilolite, Oxidation, Oxide Water Interface, Reduction, Removal, SEM, Subsurface Remediation, Wastewater, X-Ray, X-Ray Absorption, X-Ray Diffraction, Zeolite, Zero-Valent Iron, Zerovalent Iron

? Pose-Juan, E., Rial-Otero, R., Paradelo, M., Simal-Gandara, J., Arias, M. and Lopez-Periago, J.E. (2010), Behaviour of metalaxyl as copper oxychloride-metalaxyl commercial formulation vs. technical grade-metalaxyl in vineyards-devoted soils. Journal of Hazardous Materials, 174 (1-3), 181-187.

Full Text: 2010\J Haz Mat174, 181.pdf

Abstract: The objective of this work is to asses the sorption of metalaxyl applied as a copper oxychloride (CO)-metalaxyl formulation, for a set of selected soils devoted to vineyards. The method involved batch incubation of soils suspended with a commercial copper oxychloride-metalaxyl-based fungicide in 0.01 M CaCl2. Afterwards, the metalaxyl concentration remaining in solution was determined by high-performance liquid chromatography (HPLC). The amount of dissolved metalaxyl in the fungicide suspension depends mainly on the soil pH, its potential acidity, and the cation exchange capacity. Of the approx. 20% metalaxyl retained by the solid colloids, the effect of organic matter colloids in soils (15-20 mg kg(-1)) had a poor contribution (six times lower) than the copper oxychloride colloids (40%, w/w)in the commercial fungicide formulation (100-130 mg kg(-1)). When comparing these retention data with the behaviour of metalaxyl used as a technical grade fungicide of about 100% purity (10-15 mg kg(-1) in solids), it is clear that the commercial formulation increases a 30% retention of metalaxyl by soil (15-20 mg kg(-1) in solids). The overall effect of the metalaxyl formulation plus soil show values of 10 times higher retention than technical grade-metalaxyl plus soil. Commercial formulation can decrease the mobility of soluble metalaxyl in agricultural soils with regard to the expected values obtained from batch studies using analytical grade-metalaxyl. Therefore, the effect of surfactants should be considered in the assessment of water contamination by the pesticides used in agriculture. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adjuvants, Batch, Cation Exchange, Colloids, Contribution, Copper, Degradation, Fungicides, Groundwater, Metalaxyl, Mobility, Pesticides, pH, Retention, Soil, Soils, Sorption, Water

? Li, J.F., Li, Y.M. and Meng, Q.L. (2010), Removal of nitrate by zero-valent iron and pillared bentonite. Journal of Hazardous Materials, 174 (1-3), 188-193.

Full Text: 2010\J Haz Mat174, 188.pdf

Abstract: The pillared bentonite prepared by intercalating poly(hydroxo AI(Ill)) cations into bentonite interlayers was used together with Fe(0) for removing nitrate in column experiments. The obvious synergetic effect on nitrate removal was exhibited through uniformly mixing the pillared bentonite with Fe(0). In such a mixing manner, the nitrate was 100% removed, and the removal efficiency was much higher than the simple summation of adsorption by the pillared bentonite and reduction by Fe(0). The influencing factors such as bentonite type, amount of the pillared bentonite and initial pH of nitrate solutions were investigated. In this uniform mixture, the pillared bentonite could adsorb nitrate ions, and facilitated the mass transfer of nitrate onto Fe(0) surface, then accelerated the nitrate reduction. The pillared bentonite could also act as the proton-donor. and helped to keep the complete nitrate removal for at least 10 h even when the nitrate solution was fed at nearly neutral pH. (C) 2009 Published by Elsevier B.V.

Keywords: Adsorption, Adsorption, Chemical-Reduction, Chromate, Chromium(VI), Clay, Clay, Complete, Enhanced Reduction, Mass Transfer, Nitrate, pH, Reduction, Removal, Situ Redox Manipulation, Sorption, Water, Zero-Valent Iron, Zerovalent Iron

? Gao, J.F., Zhang, Q., Su, K., Chen, R.N. and Peng, Y.Z. (2010), Biosorption of Acid Yellow 17 from aqueous solution by non-living aerobic granular sludge. Journal of Hazardous Materials, 174 (1-3), 215-225.

Full Text: 2010\J Haz Mat174, 215.pdf

Abstract: Batch biosorption experiments were carried out for the removal of Acid Yellow 17 from aqueous solution using non-living aerobic granular sludge as an effective biosorbent. The effects of solution pH value, biosorbent dosage, initial Acid Yellow 17 concentration, NaCl concentration and temperature on the biosorption were investigated. The experimental results indicate that this process was highly dependent on pH value and the pH value of 2.0 was favorable. The Temkin isotherm was more applicable for describing the biosorption equilibrium at the whole concentration range than the Freundlich and Langmuir isotherm. The results of kinetics study show that the pseudo-second-order model fitted to the experimental data well. Both intraparticle diffusion and boundary layer diffusion might affect the biosorption rate. Thermodynamic studies demonstrate that the biosorption process was spontaneous and exothermic. The FTIR analysis before and after Acid Yellow 17 binding indicated that functional groups such as amine, hydroxyl, carboxyl and either on the non-living aerobic granular sludge would be the active binding sites for the biosorption of the studied dye. These results show that non-living aerobic granular sludge could be effectively used as a low-cost and alternative biosorbent for the removal of Acid Yellow 17 dye from wastewater. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Acid Yellow 17, Activated-Sludge, Alternative, Analysis, Aqueous Solution, Bagasse Fly-Ash, Basic Dye, Binding, Binding Sites, Biosorbent, Biosorption, Bottom Ash, Boundary Layer, Concentration, Data, De-Oiled-Soya, Diffusion, Dye, Equilibrium, Exothermic, Experimental, Experiments, Freundlich, FTIR, FTIR Analysis, Functional Groups, Intraparticle Diffusion, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Isotherm, Low Cost, Low-Cost Adsorbents, Malachite Green-Dye, Model, NaCl, Non-Living, Non-Living Aerobic Granular Sludge, of-the-Art, pH, pH Value, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Range, Removal, Rights, Sludge, Solution, Temkin Isotherm, Temperature, Thermodynamic, Value, Waste Materials, Wastewater, Water-Treatment

? Zabihi, M., Asl, A.H. and Ahmadpour, A. (2010), Studies on adsorption of mercury from aqueous solution on activated carbons prepared from walnut shell. Journal of Hazardous Materials, 174 (1-3), 251-256.

Full Text: 2010\J Haz Mat174, 251.pdf

Abstract: The adsorption ability of a powdered activated carbons (PAC) derived from walnut shell was investigated in an attempt to produce more economic and effective sorbents for the control of Hg(II) ion from industrial liquid streams. Carbonaceous sorbents derived from local walnut shell, were prepared by chemical activation methods using ZnCl₂ as activating reagents. Adsorption of Hg(II) from aqueous solutions was carried out under different experimental conditions by varying treatment time, metal ion concentration, pH and solution temperature. It was shown that Hg(II) uptake decreases with increasing pH of the solution. The proper choice of preparation conditions were resulted in microporous activated carbons with different BET surface areas of 780 (Carbon A, 1:0.5 ZnCl₂) and 803 (Carbon B, 1: 1 ZnCl₂) m(2)/g BET surface area. The monolayer adsorption capacity of these particular adsorbents were obtained as 151.5 and 100.9 mg/g for carbons A and B, respectively. It was determined that Hg(II) adsorption follows both Langmuir and Freundlich isotherms as well as pseudo-second-order kinetics. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbons, Activation, Adsorbents, Adsorption, Adsorption Capacity, Aqueous Solution, Aqueous Solutions, BET, BET Surface Area, Capacity, Carbon, Chemical, Chemical Activation, Choice, Concentration, Control, Economic, Experimental, Freundlich, Hg(II), Isotherms, Kinetic, Kinetics, Langmuir, Langmuir and Freundlich Isotherms, Lignin, Liquid, Local, Mercury, Metal, Methods, Monolayer, PAC, pH, Phosphoric-Acid, Pore, Preparation, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second-Order, Pseudo-Second-Order Kinetics, Removal, Rights, Solution, Solutions, Sorbent, Sorbents, Sorption, Streams, Surface, Surface Area, Surface Areas, Temperature, Treatment, Uptake, Walnut Shell, Waste-Water, ZnCl₂

? Subramanian, B., Namboodiri, V., Khodadoust, A.P. and Dionysiou, D.D. (2010), Extraction of pentachlorophenol from soils using environmentally benign lactic acid solutions. Journal of Hazardous Materials, 174 (1-3), 263-269.

Full Text: 2010\J Haz Mat174, 263.pdf

Abstract: Soil contamination with pentachlorophenol (PCP) is widespread across the globe. Soil washing/extraction is a common technique to remove this compound. Several soil washing/extraction solutions have been used but a majority of them have the problem of persistence in the environment due to their low biodegradability. Our aim was to investigate mixed solutions of lactic acid and water as potential alternatives to surfactant solutions or organic solvent systems used for the removal of PCP from three soils: montmorillonite, a natural sediment (with organic matter), and the same sediment without organic matter (ignited sediment). This study included the optimization of the concentration of lactic acid in water for maximum extraction efficiency and the determination of linear desorption constants for removal of PCP from the three soils with lactic acid. The effect of soil/sediment organic matter on the extraction efficiency was also studied. Initial experiments showed that 24 h was the optimum extraction time. High extraction efficiencies were obtained for montmorillonite (40-80%) and ignited sediment (similar to 90%). The natural sediment exhibited low PCP extraction due to presence of organic matter, while high desorption coefficient values (similar to 23 L/kg) were obtained for the ignited sediment. For all soils, a decrease in extraction was observed at higher concentrations of lactic acid. The specific surface area of soil/sediment was also found to be an important factor affecting the extraction of PCP. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Clay-Minerals, Contaminated Soil, Desorption, Extraction, Lactic Acid, Montmorillonite, Organic-Compounds, Pentachlorophenol, Potential Contributions, Removal, Sediment, Smectite Clays, Soil, Soil Organic Matter, Soils, Solvent, Sorption, Substituted Nitrobenzenes, Water, Water Systems

? Kwon, J.S., Yun, S.T., Lee, J.H., Kim, S.O. and Jo, H.Y. (2010), Removal of divalent heavy metals (Cd, Cu, Pb, and Zn) and arsenic(III) from aqueous solutions using scoria: Kinetics and equilibria of sorption. Journal of Hazardous Materials, 174 (1-3), 307-313.

Full Text: 2010\J Haz Mat174, 307.pdf

Abstract: Kinetic and equilibrium sorption experiments were conducted on removal of divalent heavy metals (Pb(II), Cu(II), Zn(II), Cd(II)) and trivalent arsenic (As(Ill)) from aqueous solutions by scoria (a vesicular pyroclastic rock with basaltic composition) from Jeju Island, Korea, in order to examine its potential use as an efficient sorbent. The removal efficiencies of Pb, Cu, Zn, Cd, and As by the scoria (size = 0.1-0.2 mm, dose = 60 g L^-1) were 94, 70, 63, 59, and 14%, respectively, after a reaction time of 24 h under a sorbate concentration of 1 mM and the solution pH of 5.0. A careful examination on ionic concentrations in sorption batches suggested that sorption behaviors of heavy metals onto scoria are mainly controlled by cation exchange. On the other hand, arsenic appeared to be sensitive to specific sorption onto hematite (a minor constituent of scoria). Equilibrium sorption tests indicated that the removal efficiency for heavy metals increases with increasing pH of aqueous solutions,which is resulted from precipitation as hydroxides. Similarly, multi-component systems containing heavy metals and arsenic showed that the arsenic removal increases with increasing pH of aqueous solutions, which can be attributed to coprecipitation with metal hydroxides. The empirically determined sorption kinetics were well fitted to a pseudo-second order model, while equilibrium sorption data for heavy metals and arsenic onto scoria were consistent with the Langmuir and Freundlich isotherms, respectively. Natural scoria studied in this work is an efficient sorbent for concurrent removal of divalent heavy metals and arsenic. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Aqueous Solutions, Arsenic, Arsenic Removal, Cadmium, Cation, Cation Exchange, Cd, Composition, Concentration, Coprecipitation, Cu, Cu(II), Data, Efficiency, Equilibria, Equilibrium, Examination, Experiments, Fly-Ash, Freundlich, Heavy Metals, Hematite, Isotherms, Kinetic, Kinetics, Korea, L1, Langmuir, Langmuir and Freundlich Isotherms, Lead(II), Metal, Metals, Minor, Model, Pb, Pb(II), pH, Potential, Precipitation, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second Order Model, Pseudo-Second-Order, Removal, Removal Efficiency, Rights, Rocks, Scoria, Single-Component, Size, Solution, Solutions, Sorbate, Sorbent, Sorption, Sorption Kinetics, Sorption Mechanisms, Systems, Uranyl, Waste, Work, Zn(II)

? Duman, O. and Ayranci, E. (2010), Adsorptive removal of cationic surfactants from aqueous solutions onto high-area activated carbon cloth monitored by in situ UV spectroscopy. Journal of Hazardous Materials, 174 (1-3), 359-367.

Full Text: 2010\J Haz Mat174, 359.pdf

Abstract: Activated carbon cloth (ACC) was used as adsorbent for the removal of cationic surfactants such as benzyltrimethylammonium chloride (BTMACl), benzyltriethylammonium chloride (BTEACl), benzyltributylammonium chloride (BTBACl), benzyldimethyldecylammonium chloride (BDMDACl), benzyldimethyltetradecyl ammonium chloride (BDMTDACl), benzyldimethylhexadecylammonium chloride (BDMHDACl), N-dodecylpyridinium chloride (N-DPCl) and N-cetylpyridinium chloride (CPCl) from aqueous solutions. The adsorption efficiency of the ACC was evaluated for cationic surfactants. Adsorption process was followed by in situ UV spectroscopic technique. The kinetic data, so obtained, were treated according to the pseudo first-order, the pseudo second-order, the Elovich and the intraparticle diffusion models in order to understand the adsorption mechanism of cationic surfactants onto the ACC. The best fit was found with the pseudo second-order model. The experimental isotherm data were obtained at 30ºC and analyzed by the Freundlich and the Langmuir models. The parameters of isotherm equations were determined. The Freundlich model was found to represent the experimental data better than the Langmuir model. The observed adsorption behaviors are discussed in terms of the pH of the solution, the nature of cationic surfactants (e.g. functional groups, size, and hydrophobicity) and the nature of the ACC (e.g. surface charge, pore size). A fair linear correlation was found between some adsorption parameters and apparent molar volumes at infinite dilution for benzyltrialkylammonium chlorides. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Acid, Activated Carbon, Activated Carbon Cloth, Adsorbent, Adsorption, Adsorption Mechanism, Ammonium, Anionic Surfactant, Aqueous Solutions, Carbon, Cationic Surfactant, Chain-Length, Charge, Chloride, Competition, Correlation, Data, Diffusion, Dilution, Efficiency, Electrodes, Electrosorption, Elovich, Experimental, First Order, Freundlich, Freundlich Model, Functional Groups, in Situ, in Situ UV Spectroscopy, Intraparticle Diffusion, Ions, Isotherm, Isotherm Equations, Isotherms, Kinetic, Langmuir, Langmuir Model, Mechanism, Model, Models, pH, Pseudo First Order, Pseudo First-Order, Pseudo Second Order, Pseudo Second-Order, Pseudo-First-Order, Pseudo-Second-Order, Quaternary Ammonium Chlorides, Removal, Rights, Second Order, Second-Order, Second-Order Model, Size, Solution, Solutions, Sorption, Spectroscopy, Surface, Surface Charge, Surfactants, UV, Waste-Water Purification

? Li, J., Wu, F., Mailhot, G. and Deng, N.S. (2010), Photodegradation of chloroform in aqueous solution: Impact of montmorillonite KSF particles. Journal of Hazardous Materials, 174 (1-3), 368-374.

Full Text: 2010\J Haz Mat174, 368.pdf

Abstract: In this work, photodegradation of chloroform in water suspensions of montmorillonite KSF (KSF) under a black light lamp (lambda = 365 nm) was investigated. The results showed that KSF induced the photodegradation of chloroform by producing hydroxyl radical ((OH)-O-center dot) that oxidized chloroform in the heterogeneous clay-water systems. The photodegradation of chloroform in KSF suspensions was greatly influenced by the concentration of KSF and the pH of KSF suspensions. The photodegradation of chloroform by KSF followed the Langmuir-Hinshelwood Model. Furthermore, the removal efficiency of chloroform can be enhanced by the presence of carboxylates (oxalate and citrate) and humic acid (HA). This work demonstrates that KSF can be used as a new and efficient photocatalyst in oxidation and removal of organic compounds. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Carboxylic Salts, Chloroform, Clay, Compounds, Ha, Hydroxyl Radicals, Irradiation, Model, Montmorillonite, Montmorillonite Ksf, Organic Compounds, Organic-Matter, Oxidation, pH, Photocatalytic Degradation, Photodegradation, Removal, Surface, Suspensions, TiO₂, Water

? Yusof, A.M., Keat, L.K., Ibrahim, Z., Majid, Z.A. and Nizam, N.A. (2010), Kinetic and equilibrium studies of the removal of ammonium ions from aqueous solution by rice husk ash-synthesized zeolite Y and powdered and granulated forms of mordenite. Journal of Hazardous Materials, 174 (1-3), 380-385.

Full Text: 2010\J Haz Mat174, 380.pdf

Abstract: The removal of ammonium from aqueous solutions using zeolite NaY prepared from a local agricultural waste, rice husk ash waste was investigated and a naturally occurring zeolite mordenite in powdered and granulated forms was used as comparison. Zeolite NaY and mordenite were well characterized by powder X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis and the total cation exchange capacity (CEC). CEC of the zeolites were measured as 3.15, 1.46 and 1.34 meq g(-1) for zeolite Y, powdered mordenite and granular mordenite, respectively. Adsorption kinetics and equilibrium data for the removal of NH₄⁺ ions were examined by fitting the experimental data to various models. Kinetic studies showed that the adsorption followed a pseudo-second-order reaction. The equilibrium pattern fits well with the Langmuir isotherm compared to the other isotherms. The monolayer adsorption capacity for zeolite Y (42.37 mg/g) was found to be higher than that powdered mordenite (15.13 mg/g) and granular mordenite (14.56 mg/g). Thus, it can be concluded that the low cost and economical rice husk ash-synthesized zeolite NaY could be a better sorbent for ammonium removal due to its rapid adsorption rate and higher adsorption capacity compared to natural mordenite. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Capacity, Adsorption Kinetics, Adsorption Rate, Agricultural, Agricultural Waste, Ammonium, Ammonium Removal, Analysis, Aqueous Solution, Aqueous Solutions, Capacity, Cation, Cation Exchange, CEC, Clinoptilolite, Comparison, Cost, Data, EDX, Energy, Equilibrium, Equilibrium Studies, Exchange, Experimental, Forms, Ions, Isotherm, Isotherm Equilibrium Study, Isotherms, Kinetic, Kinetic Studies, Kinetic Study, Kinetics, Langmuir, Langmuir Isotherm, Local, Low Cost, Models, Monolayer, Mordenite, Natural, Natural Zeolites, Pattern, Pseudo Second Order, Pseudo-Second-Order, Removal, Rice, Rice Husk, Rice Husk Ash, Rice-Husk, Rights, Sepiolite, Solution, Solutions, Sorbent, Waste, Waste-Water, X-Ray, X-Ray Diffraction, XRD, Zeolite, Zeolite Y, Zeolites

? Afkhami, A. and Moosavi, R. (2010), Adsorptive removal of Congo red, a carcinogenic textile dye, from aqueous solutions by maghemite nanoparticles. Journal of Hazardous Materials, 174 (1-3), 398-403.

Full Text: 2010\J Haz Mat174, 398.pdf

Abstract: The adsorption of Congo red (CR) onto maghemite nanoparticles (gamma-Fe2O3) and its desorption was investigated. The adsorption capacity was evaluated using both the Langmuir and Freundlich adsorption isotherm models. Maghemite nanoparticles (gamma-Fe2O3) were prepared easily in a surfactant-less microemulsion by co-precipitation method. The size of the produced maghemite nanoparticles was determined by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). Synthesized maghemite nanoparticles showed the highest adsorption capacities of CR compared to many other adsorbents and would be a good method to increase adsorption efficiency for the removal of CR in a wastewater treatment process. The maximum adsorption occurred at pH 5.9. The Langmuir adsorption capacity (q(max)) was found to be 208.33 mg g(-1) of the adsorbent. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Acid, Activated Carbon, Adsorption, Adsorption Capacity, Adsorption Isotherm, Analysis, Aqueous Solutions, Bentonite, Congo Red, Congo Red Adsorption, Desorption, Dye, Equilibrium, Ferrofluid, Freundlich, Iron-Oxide Nanoparticles, Isotherm, Isotherm Models, Kinetics, Langmuir, Maghemite, Maghemite Nanoparticles, Magnetic Nanoparticles, Nanoparticles, Particles, pH, Removal, Sem, Treatment, Waste Water Samples, Waste-Water, Wastewater, Wastewater Treatment, X-Ray, X-Ray Diffraction, XRD

? Adav, S.S., Lee, D.J. and Lai, J.Y. (2010), Aerobic granules with inhibitory strains and role of extracellular polymeric substances. Journal of Hazardous Materials,