Personal Research Database

Full Text: 2009\J Haz Mat166, 734.pdf

Abstract: Bed filters using reactive materials are an emerging technology for on-site wastewater treatment. Used materials, which are enriched with phosphorus, can be used as a fertiliser or soil amendment. However the materials can also be enriched with metals from the wastewater. Six materials (opoka, sand, Polonite (R), limestone, two types of blast furnace slag) exposed to long-term wastewater loading in columns and in a compact filter well filled with Polonite were investigated for metal removal and accumulation. Wastewater applied to the columns had low heavy metal concentrations in the order Zn > Cu > Mn > Ni > Cr. All columns were able to remove 53%-83% of Zn except those filled with sand. Polonite demonstrated a high removal capacity of Mn (>98%), while only the slag materials were able to remove Ni. All materials showed increased Cu, Cr(III). Mn. Pb and Zn content after filtration. Speciation calculations showed that high concentrations of dissolved organic matter might have prevented efficient metal removal, particularly in the case of Cu. The low content of toxic heavy metals in the studied filter materials studied would probably not restrict their use as a fertiliser or soil amendment. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Blast Furnace Slag, Blast-Furnace Slag, Calcite, Capacity, Column Experiment, Contamination, Cr(III), Cu, Elsevier, Fertilizer, Heavy Metal, Heavy Metals, Heavy-Metals, Ions, Metal, Metal Removal, Metals, Pb, Phosphorus, Phosphorus Retention, Polonite (R), Removal, Soil Amendment, Sorbents, Sorption, Speciation, Technology, Treatment, Wastewater, Wastewater Treatment, Wetlands, Zinc

? Montes-Hernandez, G., Concha-Lozano, N., Renard, F. and Quirico, E. (2009), Removal of oxyanions from synthetic wastewater via carbonation process of calcium hydroxide: Applied and fundamental aspects. Journal of Hazardous Materials, 166 (2-3), 788-795.

Full Text: 2009\J Haz Mat166, 788.pdf

Abstract: Removal of oxyanions (selenite, selenate, arsenate, phosphate and nitrate) during calcite formation was experimentally studied using aqueous carbonation of calcium hydroxide under moderate pressure (P-CO₂ congruent to 20 bar) and temperature (30°C). The effects of Ca(OH)₂ dose (10 and 20g), Ca(OH)₂ source (commercial pure material or alkaline paper mill waste) and oxyanion initial concentration (from 0 to 70 mg atom/L) were investigated for this anisobaric gas-liquid-solid system. The Ca(OH)₂ carbonation reaction allowed successfully the removal of selenite (>90%). arsenate (>78%) and phosphate (congruent to 100%) from synthetic solutions. Conversely, nitrate and selenate had not any physicochemical affinity/effect during calcite formation. The rate of CO₂ transfer during calcite formation in presence of oxyanions was equal or slower than for an oxyanion-free system, allowing to define a retarding kinetic factor RF that can vary between 0 (no retarding effect) to 1 (total inhibition). For selenite and phosphate RF was quite high, close to 0.3. A small retarding effect was detected for arsenate (RF approximate to 0.05) and no retarding effect was detected for selenate and nitrate (RF approximate to 0). In general, RF depends on the oxyanion initial concentration, oxyanion nature and Ca(OH)₂ dose. The presence of oxyanions could also influence the crystal morphology and aggregation/agglomeration process. For example, a c-axis elongation of calcite crystals was clearly observed at the equilibrium, for calcite formation in presence of selenite and phosphate. The oxyanions removal process proposed herein was inspired on the common physicochemical treatment of wastewater using calcium hydroxide Ca(OH)₂. The particularity, for this novel method is the simultaneous calcium hydroxide carbonation with compressed carbon dioxide in order to stabilise the solid matter. This economical and ecological method could allow the removal of various oxyanions as well as the ex situ mineral sequestration of CO₂; particularly, when the Ca(OH)₂ source comes from alkaline solid waste. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Amorphous Iron Oxyhydroxide, Aqueous, Aqueous Carbonation, Arsenate, Calcium Hydroxide, Carbon, Carbon Dioxide, Chromate, CO₂, Coprecipitation, Crystal-Growth, Elsevier, Equilibrium, Interface, Kinetic, Mechanisms, Mineralization of CO₂, Oxyanions, Phosphate, Precipitation, Removal, Scattering, Selenate, Selenite, Solutions, Sorption, System, Temperature, Treatment, Wastewater, Water Treatment

? Zhang, J.H., He, M.C. and Shi, Y.H. (2009), Comparative sorption of benzo[]phrene to different humic acids and humin in sediments. Journal of Hazardous Materials, 166 (2-3), 802-809.

Full Text: 2009\J Haz Mat166, 802.pdf

Abstract: Sediment/soil organic matter (SOM) is the predominant sorbents for hydrophobic organic compounds (HOCs). The identification and comparison of sorption characterization of HOCs by different organic matter fractions are essential to predict the fate and transport of HOCs in soils and sediments. The objectives of this paper are to compare the sorption of benzo[alpha]phrene (BaP) to the humic acid (HA) and humin (HM) extracted from different sediments. The HA and HM were extracted with 0.1 M NaOH from five sediments in different areas in China, and their sorption isotherms for BaP were determined. All sorption isotherms were nonlinear and nonlinearity increased in the order HA < sediment < HM. BaP sorption capacities on the HA fractions were significantly related to their aliphaticity, but negatively correlated to aromatic carbon. However, more aromatic carbon in HM fractions can result in higher K-oc values of BaP than HA. This implied the importance of both aliphatic and aromatic groups in BaP sorption. HM contributed to 54-92% of the total sorption depending on initial concentrations, clearly indicating the dominance of HM in BaP sorption by the sediments. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Benzo[Alpha]Phrene (BaP), Carbon, China, Desorption, Distributed Reactivity Model, Elsevier, Equilibrium Sorption, Fractions, Groups, Humic Acid, Humic Acids, Humin, Hydrocarbons, Isotherms, Organic Compounds, Phenanthrene Sorption, Pollutants, Pyrene, Sediment, Sediments, Soil Organic-Matter, Soils, Sorption, Transport

? Yuan, P., Fan, M.D., Yang, D., He, H.P., Liu, D., Yuan, A.H., Zhua, J.X. and Chen, T.H. (2009), Montmorillonite-supported magnetite nanoparticles for the removal of hexavalent chromium [Cr(VI)] from aqueous solutions. Journal of Hazardous Materials, 166 (2-3), 821-829.

Full Text: 2009\J Haz Mat166, 821.pdf

Abstract: Montmorillonite-supported magnetite nanoparticles were prepared by co-precipitation and hydrosol method. The obtained materials were characterized by X-ray diffraction, nitrogen adsorption, elemental analysis, differential scanning calorimetry, transmission electron microscopy and X-ray photoelectron spectroscopy. The average sizes of the magnetite nanoparticles without and with montmorillonite support are around 25 and 15 nm, respectively. The montmorillonite-supported magnetite nanoparticles exist on the surface or inside the interparticle pores of clays, with better dispersing and less coaggregation than the ones without montmorillonite support. Batch tests were carried out to investigate the removal mechanism of hexavalent chromium [Cr(VI)] by these synthesized magnetite nanoparticles. The Cr(VI) uptake was mainly governed by a physico-chemical process, which included an electrostatic attraction followed by a redox process in which Cr(VI) was reduced into trivalent chromium. The adsorption of Cr(VI) was highly pH-dependent and the kinetics of the adsorption followed the Pseudo-second-order model. The adsorption data of unsupported and clay-supported magnetite nanoparticles fit well with the Langmuir and Freundlich isotherm equations. The montmorillonite-supported magnetite nanoparticles showed a much better adsorption capacity per unit mass of magnetite (15.3 mg/g) than unsupported magnetite (10.6 mg/g), and were more thermally stable than their unsupported counterparts. These fundamental results demonstrate that the montmorillonite-supported magnetite nanoparticles are readily prepared, enabling promising applications for the removal of Cr(VI) from aqueous solution. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbons, Adsorption, Adsorption Capacity, Aqueous, Batch Tests, Capacity, Chromium, Clay, Cr(VI), Elsevier, Fly-Ash, Freundlich, Freundlich Isotherm, Hexavalent Chromium, Isotherm, Kinetics, Langmuir, Magnetite, Mechanism, Metal Removal, Montmorillonite, Nanoparticles, Nitrogen, Particles, Pseudo Second Order, Pseudo-Second-Order Model, Reduction, Removal, Solutions, Sorption, Spectroscopy, Transmission Electron Microscopy, Waste-Water, Zero-Valent Iron

? Eren, E. and Afsin, B. (2009), Removal of basic dye using raw and acid activated bentonite samples. Journal of Hazardous Materials, 166 (2-3), 830-835.

Full Text: 2009\J Haz Mat166, 830.pdf

Abstract: The adsorption behavior of crystal violet (CV+) from aqueous solution onto raw (RB) and acid activated (AAB) bentonite samples was investigated as a function of parameters such as initial CV+ concentration, contact time and temperature. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. The adsorption rate was fast and more than half of the adsorbed-CV+ was removed in the first 55 min for RB and 25 min for 0.2-AAB at the room temperature (C-0 = 1.2 mmol/g). The pseudo-first order, and pseudo-second order kinetic models were used to describe the kinetic data and rate constants were evaluated. The results best fit the pseudo-second order kinetic model with the rate constant, k(2), in the range of 13.5210^-2 to 5.5310^-2 g/mmol and 52.7010^-2 to 6.6910^-2 mmol/g min for RB and 0.2-AAB sample, respectively (C-0 = 0.1-1.2 mmol/g). (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Acid Activation, Activation Thermodynamic, Adsorption, Adsorption Rate, Aqueous, Aqueous-Solution, Basic Dye, Bentonite, Cations, Clays, Crystal Violet, Dye, Dye Adsorption, Elsevier, Equilibrium, Freundlich, Isotherms, Kinetic, Kinetic Models, Kinetics, Langmuir, Model, Models, Pseudo Second Order, Pseudo-First Order, Pseudo-Second Order, Pseudo-Second-Order, Removal, Sorption, Temperature, Thermodynamics, Water, X-Ray Diffraction

? Ahmadpour, A., Tahmasbi, M., Bastami, T.R. and Besharati, J.A. (2009), Rapid removal of cobalt ion from aqueous solutions by almond green hull. Journal of Hazardous Materials, 166 (2-3), 925-930.

Full Text: 2009\J Haz Mat166, 925.pdf

Abstract: Almond green hull, an agriculture solid waste, was chemically treated and used for the adsorption of Co(II) from aqueous solutions. The efficiency of this new adsorbent was studied using batch adsorption technique under different experimental conditions such as sorbent amount, initial metal-ion concentration, contact time, adsorbent particle size, and chemical treatment. Optimum dose of sorbent for maximum metal-ion adsorption were 0.25g for 51.5 mg l^-1 and 0.4 g for 110 mg l^-1 solutions, respectively. High removal efficiencies of Co(II) were occurred in the first 1 min of sorbent contact time. The adsorption of Co(II) on almond green hull was also observed to follow the pseudo second-order kinetics. Adsorption isotherms were expressed by Langmuir and Freundlich adsorption models. The Langmuir adsorption model fits the experimental data reasonably well compared to the Freundlich model. The maximum adsorption capacity of this new sorbent was found to be 45.5 mg g^-1. The present study revealed that such a low cost material could be used as an efficient sorbent for the removal of cobalt from wastewater streams. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption Capacity, Adsorption Isotherms, Adsorptive Removal, Agricultural Waste, Almond, Almond Green Hull, Aqueous, Bagasse Fly-Ash, Biosorption, Capacity, Co(II), Cobalt, Coir Pith, Elsevier, Exchange, Freundlich, Heavy-Metals, Isotherms, Kinetics, Langmuir, Models, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo Second-Order, Pseudo-Second-Order, Removal, Second Order, Solutions, Sorbent, Sugar-Industry Waste, Treatment, Wastewater, Water

? Haghsheno, R., Mohebbi, A., Hashemipour, H. and Sarrafi, A. (2009), Study of kinetic and fixed bed operation of removal of sulfate anions from an industrial wastewater by an anion exchange resin. Journal of Hazardous Materials, 166 (2-3), 961-966.

Full Text: 2009\J Haz Mat166, 961.pdf

Abstract: Sulfate anions represent very important wastewater pollutants, which appear in the effluents discharged from copper mines. In this study, for the first time, an attempt has been made on the removal of sulfate anions by an ion exchange resin. This work is focused on the removal of sulfate anions from the Sarcheshmeh copper complex (Kerman province, Southeast of Iran) wastewater by an anion exchange resin. Batch experiments of sulfate anions adsorption on Lewatit K6362 resin were carried out to determine the adsorption equilibrium data and the relation of adsorption isotherms. Isothermal data can be fitted with Freundlich adsorption isotherms better than Langmuir equation. The results show that maximum removal of sulfate anions take places in the resin dosage of 1000 mg, 100 ml and the adsorption of sulfate anions on the resin follows reversible first-order kinetics. The overall adsorption rate constants were compared for different initial concentrations. Finally, the effects of parameters such as the flow rate, bed height and inlet adsorbate concentration on the breakthrough curve in a fixed bed column were studied in detail. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Equilibrium, Adsorption Isotherms, Adsorption Rate, Adsorptive Removal, Anion Exchange, Anions, Aqueous-Solution, Batch, Breakthrough Curve, CO(II), Column, Copper, Effluents, Equilibrium, First Order, Fixed Bed, Freundlich, Industrial Wastewater, Ion Exchange, Ion-Exchange, Iran, Isothermal, Isotherms, Kinetic, Kinetics, Langmuir, NI(II), Peat, Pollutants, Removal, Resin, Sorption, Sulfate, Wastewater

? Qaiser, S., Saleemi, A.R. and Umar, M. (2009), Biosorption of lead from aqueous solution by Ficus religiosa leaves: Batch and column study. Journal of Hazardous Materials, 166 (2-3), 998-1005.

Full Text: 2009\J Haz Mat166, 998.pdf

Abstract: The biosorption of lead by Ficus religiosa leaves (FRLs) in powder and immobilized form was investigated. Batch experiments were conducted to determine the biosorption capacity, equilibrium time, optimal pH and temperature. The maximum biosorption capacity of lead was 37.45 mg g(-1) at optimal pH of 4. The temperature change in the range of 20-40 degrees C affected the biosorption capacity and the maximum removal was observed at 25 degrees C. The thermodynamics parameters were determined from experimental data. The Langmuir and Freundlich models were used to explain the equilibrium data. The Langmuir model showed better fit of data with correlation coefficient of 0.97. The kinetics of biosorption followed pseudo second order model. For continuous biosorption experiments, FRLs biomass was immobilized in polysulfone matrix. Breakthrough curves were analyzed at different flow rates. pH and bed depth. Bed depth service time (BDST) and the Thomas models were used to describe the experimental data. A solution of 0.05 M HNO(3) did well to elute lead from biomass. The release of Ca, Mg and Na ions during lead biosorption revealed that ion exchange was the major removal mechanism. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aspergillus-Niger, Batch, Biosorption, Breakthrough, Capacity, Column, Column Study, Depth, Equilibrium, Equilibrium, Experimental, Fixed-Bed, Freundlich, Heavy-Metals, Husk, Ion Exchange, Ions, Kinetics, Langmuir, Langmuir and Freundlich Models, Langmuir Model, Lead, Mechanism, Model, pH, Pseudo-Second-Order, Removal, Sorption, Thermodynamics, Waste-Water

? Rao, M.M., Ramana, D.K., Seshaiah, K., Wang, M.C. and Chien, S.W.C. (2009), Removal of some metal ions by activated carbon prepared from Phaseolus aureus hulls. Journal of Hazardous Materials, 166 (2-3), 1006-1013.

Full Text: 2009\J Haz Mat166, 1006.pdf

Abstract: Removal of lead [Pb(II)], zinc [Zn(II)], copper [Cu(II)], and cadmium [Cd(II)] from aqueous solutions using activated carbon prepared from Phaseolus aureus hulls (ACPAH), an agricultural waste was studied. The influence of various parameters such as effect of pH, contact time, adsorbent dose, and initial concentration of metal ions on the removal was evaluated by batch method. The removal of metal ions by ACPAH was pH dependent and the optimum pH values were 7.0, 8.0, 7.0 and 6.0 for Cu(II), Cd(II), Zn(II), and Pb(II), respectively. The sorption isotherms were studied using Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherm models. The maximum adsorption capacity values of ACPAH for metal ions were 21.8 mg g(-1) for Pb(II), 21.2 mg g(-1) for Zn(II), 19.5 mg g(-1) for Cu(II), and 15.7 mg g(-1) for Cd(II). The experiments demonstrated that the removal of metal ions followed the pseudo-second-order kinetic model. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorption, Agricultural Waste, Apricot Stone, Aqueous-Solution, Batch Method, Cadmium, Cadmium, Capacity, Cd(II), Chemical-Properties, Copper, Cu(II), Desorption, Freundlich, Heavy-Metals, Ions, Isotherm, Isotherm Models, Isotherms, Kinetic, Kinetic Model, Langmuir, Lead, Mercury, Metal, Metal Ions, Model, Nanotubes, Pb(II), pH, Phaseolus Aureus Hulls, Pseudo-Second-Order, Removal, Sorption, Waste-Water, Zinc, Zn(II)

? Valsala, T.P., Roy, S.C., Shah, J.G., Gabriel, J., Raj, K. and Venugopal, V. (2009), Removal of radioactive caesium from low level radioactive waste (LLW) streams using cobalt ferrocyanide impregnated organic anion exchanger. Journal of Hazardous Materials, 166 (2-3), 1148-1153.

Full Text: 2009\J Haz Mat166, 1148.pdf

Abstract: The volumes of low level waste (LLW) generated during the operation of nuclear reactor are very high and require a concentration step before suitable matrix fixation. The volume reduction (concentration) is achieved either by co-precipitating technique or by the use of highly selective sorbents and ion exchange materials. The present study details the preparation of cobalt ferrocyanicle impregnated into anion exchange resin and its evaluation with respect to removal of Cs in LLW streams both in column mode and batch mode operations. The Kd values of the prepared exchanger materials were found to be very good in actual reactor LLW solutions also. It was observed that the exchanger performed very well in the pH range of 3-9. A batch size of 6 g l(-1) of the exchanger was enough to give satisfactory decontamination for Cs in actual reactor LLW streams. The lab scale and pilot plant scale performance of the exchanger material in both batch mode and column mode operations was very good. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Anion Exchange, Anion Exchanger, Batch, Chemical Treatment, Cobalt, Cobalt Ferrocyaide, Column, Decontamination Factor, Evaluation, Hexacyanoferrate(II), Ion Exchange, Ion-Exchange, Low, Low Level Waste, Natural-Waters, pH, Plant, Preparation, Radioactivity, Radiocesium, Reduction, Removal, Resin, Silica-Gel, Sorption, Spike Solution, Waste

? Ngomsik, A.F., Bee, A., Siaugue, J.M., Talbot, D., Cabuil, V. and Cote, G. (2009), Co(II) removal by magnetic alginate beads containing Cyanex 272 (R). Journal of Hazardous Materials, 166 (2-3), 1043-1049.

Full Text: 2009\J Haz Mat166, 1043.pdf

Abstract: In this study, a series of batch experiments is conducted to investigate the ability of magnetic alginate beads containing Cyanex 272 (R) to remove Co(II) ions from aqueous solutions. Equilibrium sorption experiments show a Co(II) uptake capacity of 0.4 mmol g(-1). The data are successfully modelled with a Langmuir equation. A series of kinetics experiments is then carried out and a pseudo-second order equation is used to fit the experimental data. The effect of pH on the sorption of Co(II) ions is also investigated. Desorption experiments by elution of the loaded beads with nitric acid at pH I show that the magnetic alginate beads could be reused without significant losses of their initial properties even after 3 adsorption-desorption cycles. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption-Desorption, Alginate, Aqueous-Solution, Capacity, Co(II), Desorption, Equilibrium, Experimental, Filtration Process, Heavy Metals, Heavy-Metals, Ions, Kinetics, Langmuir, Maghemite, Magnetic Separation, Nanoparticles, Nickel, pH, Pseudo-Second Order, Pseudo-Second-Order, Recovery, Remediation, Removal, Solvent-Extraction, Sorption, Uptake, Water

? Ranjan, D., Talat, M. and Hasan, S.H. (2009), Biosorption of arsenic from aqueous solution using agricultural residue ‘rice polish’. Journal of Hazardous Materials, 166 (2-3), 1050-1059.

Full Text: 2009\J Haz Mat166, 1050.pdf

Abstract: ‘Rice polish’ (an agricultural residue) was utilized successfully for the removal of arsenic from aqueous solution. Various parameters viz. pH, biosorbent dosage, initial metal ion concentration and temperature were studied. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models were used and the system followed all three isotherms, showing sorption to be monolayer on the heterogeneous surface of the biosorbent. The maximum sorption capacity calculated using Langmuir model was 138.88 mu g, g for As(III) at 20 degrees C and pH 7.0 and 147.05 mu g, g at 20 degrees C and pH 4.0 for As(V). The mean sorption energy (E) calculated from D-R model indicated chemisorption nature of sorption. Study of thermodynamic parameters revealed the exothermic, spontaneous and feasible nature of sorption process in case of both As(III) and As(V). The pseudo-second-order rate equation described better the kinetics of arsenic sorption with good correlation coefficients than pseudo-first-order equation. Mass transfer, intraparticle diffusion, richenberg and elovich models were applied to the data and it was found that initially the sorption of arsenic was governed by film diffusion followed by intraparticle diffusion. Rice polish was found to be efficient in removing arsenic from aqueous solution as compared to other biosorbents already used for the removal of arsenic. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorbents, Adsorption, Arsenic, As(III), As(V), Biosorption, Cadmium, Capacity, Coated Cement IOCC, Diffusion, Energy, Equilibrium, Freundlich, Intraparticle Diffusion, Isotherm, Isotherm Models, Isotherms, Kinetics, Langmuir, Langmuir Model, Mass Transfer, Metal, Metal Ion, Model, pH, Pseudo-First-Order, Pseudo-Second-Order, Removal, Rice, Rice Polish, Sorption, Sorption Kinetics, Thermodynamic Parameters, Waste-Water

? Noroozifar, M., Khorasani-Motlagh, M. and Fard, P.A. (2009), Cyanide uptake from wastewater by modified natrolite zeolite-iron oxyhydroxide system: Application of isotherm and kinetic models. Journal of Hazardous Materials, 166 (2-3), 1060-1066.

Full Text: 2009\J Haz Mat166, 1060.pdf

Abstract: A method for the removal of cyanides from wastewater is described. The method involves the adsorption of cyanides by a modified natural zeolite (natrolite) using batch technique. A new iron oxyhydroxide-natrolite system was used in this study. A combination of XRD, XRF and FTIR spectroscopies, as well as TG, DSC thermal analyses was used for characterization of zeolitic materials. such as pH, amount of adsorbent and contact time on the Cyanide removing Effects of parameters. yield are studied. It was observed that the yield increases by increasing dosage of adsorbent and contact time at a fixed pH 7.5. A yield of 82% was achieved at optimum conditions for removing cyanide from industrial wastewaters. The experimental data obtained for optimum conditions were selected for modeling the adsorption behavior of the materials using six isotherm equations (Freundlich, Langmuir, Langmuir-Freundlich, Dubinin-Radushkevich, Redlich-Peterson and Toth). The obtained modeling results indicated that, although the three-parameter models, taking into account the surface heterogeneity, provided the closest approach to the measurement data, the parameters estimates could be highly biased. The kinetic studies proved that the second-order kinetic was the applicable model. (C) 2009 Published by Elsevier B.V.

Keywords: Activated Carbon, Adsorbent, Adsorption, Behavior, Characterization, Cyanide, Experimental, Freundlich, FTIR, Ions, Iron, Iron Oxyhydroxide-Natrolite, Isotherm, Kinetic, Kinetic Models, Langmuir, Measurement, Model, Modeling, Modification, Modified, Natrolite, Natural, Natural Zeolite, Oxidation, pH, Removal, Sorption, Uptake, Wastewater, XRD, XRF, Zeolite

? Li, K.Q., Zheng, Z., Feng, J.W., Zhang, J.B., Luo, X.Z., Zhao, G.H. and Huang, X.F. (2009), Adsorption of p-nitroaniline from aqueous solutions onto activated carbon fiber prepared from cotton stalk. Journal of Hazardous Materials,