Personal Research Database

Full Text: 2008\J Haz Mat151, 628.pdf

Abstract: Arsenic is present at relatively high concentrations in surface water and groundwater as a result of both natural impacts and anthropogenic discharge, which requires proper treatment before use. The present study describes As adsorption on a siderite-hematite filter as a function of activating condition, empty bed contact time, and As species. Hydrogen peroxide activating increased As adsorption on siderite by 16.2 g/g, and on hematite by 13.0 g/g. The H₂O₂ conditioning enhanced adsorption efficiency of activated siderite-hematite filters up to throughput of 500 pore volumes of 500 mu g/L As water. At values greater than 47 min, the empty bed contact time (EBCT) had only a weak influence on the removal capacity of pristine siderite-hematite filters. Due to the formation of fresh Fe(III)-oxide layer in the H₂O₂-conditioned filter and the pristine hematite-siderite filter, both of them may be utilized as a cost-effective reactor for treating As water. A toxicity characteristic leaching procedure (TCLP) test showed that the spent minerals were not hazardous and could be safely landfilled. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Arsenate, Arsertite, Dimethylarsinic Acid, Fenton’s Reagent, Removal, Contaminated Water, Fentons Reagent, Drinking-Water, Removal, Iron, Sorption, Groundwater, Speciation, Ferrihydrite, Desorption

? Eren, E. and Afsin, B. (2008), An investigation of Cu(II) adsorption by raw and acid-activated bentonite: A combined potentiometric, thermodynamic, XRD, IR, DTA study. Journal of Hazardous Materials, 151 (2-3), 682-691.

Full Text: 2008\J Haz Mat151, 682.pdf

Abstract: Adsorption of Cu(II) by raw bentonite (RB) and acid-activated bentonite (AAB) samples was investigated as a function of the initial Cu(II) concentration, solution pH, ionic strenght, temperature, the competitive and complexation effects of ligands (Cl-, SO42-, PO43-). Langmuir monolayer adsorption capacity of the RB (42.41 mg g(-1)) was found greater than that of the AAB (32.17 mg g(-1)). The effect of structural charges on the reactivity of the edge groups was evidenced by the particular proton adsorption behaviour of the bentonite samples. The spontaneity of the adsorption process is established by decrease in Delta G which varied from -034 to -0.71 kJ mol(-1) (RB), -1.13 to -1.49 kJ mol(-1) (AAB) in temperature range 303-313 K. Infrared (IR) spectra of the bentonite samples showed that the positions and shapes of the fundamental vibrations of the OH and Si-O groups were influenced by the adsorbed Cu(II) cations. Differential thermal analysis (DTA) results showed that adsorbed Cu(II) cations have a great effect on the thermal behaviour of the bentonite samples. The X-ray diffraction (XRD) spectra indicated that the Cu(II) adsorption onto the bentonite samples led to changes in unit cell dimensions and symmetry of the parent bentonites. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Acid-Activated Bentonite, Adsorption, Adsorption Capacity, Analysis, Behaviour, Bentonite, Bentonites, Capacity, Cations, Changes, Clay, Clays, Competitive, Complexation, Concentration, Copper(II), Cu(II), Cu(II) Adsorption, Effects, Function, Heavy-Metal, Heavy-Metals, Investigation, IR, Kaolinite, Langmuir, Ligands, Mar, Mercury(II), Monolayer, Montmorillonite, pH, Rights, Soils, Solution, Sorption, Surface Charge, Temperature, Thermal Analysis, Thermodynamic, Water, X-Ray, X-Ray Diffraction, XRD

? Hojamberdiev, M., Kameshima, Y., Nakajima, A., Okada, K. and Kadirova, Z. (2008), Preparation and sorption properties of materials from paper sludge. Journal of Hazardous Materials, 151 (2-3), 710-719.

Full Text: 2008\J Haz Mat151, 710.pdf

Abstract: Three materials were prepared from paper sludge (PS) using different treatment processes and their sorption abilities for phosphate and methylene blue (MB) were determined. The samples were a powder sample prepared by heating PS in air (sample C), a pellet prepared by grinding, forming and heating PS in air (sample G) and a powder prepared by physical activation of PS in flowing wet nitrogen (sample A). The three samples were heated at 600-900C for 6h. On heating at 700-800C, the organic fibers, limestone (CaCO₃) kaolinite (Al₂Si₂O₅(OH)₄) and talc (Mg₃Si₄O₁₀(OH)₂) in the original PS were converted to amorphous CaO-Al₂O₃-SiO₂ (CAS) and talc in sample C, while CAS was formed in sample G and activated carbon, CAS and talc was formed in sample A. On heating at 900C the CAS converted to gehlenite (Ca₂Al₂SiO₇) and anorthite (CaAl₂Si₂O₈). The specific surface areas (SBET) of the three samples achieved maximum values of 23, 37 and 70 m²/g upon heating at 700, 600 and 600C, respectively. The SBET value of the activated sample A was distinctly lower than usually reported for activated carbon. The samples C, G and A achieved maximum phosphate sorption capacities of 2.04, 1.38 and 1.70 mmol/g, calculated from the Langmuir model, upon heating at 700, 700 and 800 C, respectively. The maximum sorption capacity for phosphate in sample C is attributed to the sorption by CAS, namely, adsorption on the alumina component and precipitation as Ca-phosphates. The MB multifunctional sorption capacity of sample A was 0.11 mmol/g. The phosphate and MB sorption rates show better correlation with a pseudo-second order model than with other models. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Activation, Adsorbents, Adsorption, Alumina, Ash, Calcination, Capacity, Carbon, Carbons, Composites, Fibers, Kaolinite, Langmuir, Mechanical Grinding, Methylene Blue, Methylene-Blue, Model, Models, Paper Sludge, Phosphate, Phosphate Ion, Phosphate Removal, Phosphorus Removal, Physical Activation, Physical Activation, Pseudo-Second Order, Rights, Simultaneous Sorption, Sludge, Sorption, Treatment, Waste-Water

? Ardejani, F.D., Badii, K., Limaee, N.Y., Shafaei, S.Z. and Mirhabibi, A.R. (2008), Adsorption of Direct Red 80 dye from aqueous solution onto almond shells: Effect of pH, initial concentration and shell type. Journal of Hazardous Materials, 151 (2-3), 730-737.

Full Text: 2008\J Haz Mat151, 730.pdf

Abstract: The adsorption of Direct Red 80 (DR 80) dye from aqueous solution on almond shells as an eco-friendly and low-cost adsorbent was studied. The effect of shell type (internal, external and mixture shells), pH and initial dye concentration were considered to evaluate the sorption capacity of almond shell adsorbent. The mixture type of almond shell showed to be more effective. The adsorption studies revealed that the mixture type of almond shells remove about 97% of the DR 80 dye from aqueous phase after I h of the adsorption process in a batch system. Although, pH changes did not appreciably affect the adsorption process but the maximum adsorption capacity of different types of almond shells (20.5, 16.96 and 16.4 mg/g for mixture, external and internal shells) were obtained at pH 2. However, in order to have a better control on the experimental conditions, pH 6 was selected for conducting all adsorption experiments. Initial dye concentration was varied from 50 to 150 mg/L. Higher concentrations of dye in aqueous solution reduced DR 80 dye adsorption efficiency of almond shells. Equilibrium data were attempted by various adsorption isotherms including Langmuir, Freundlich and Brunauer-Emmett-Teller (BET) models. It was found that the adsorption process by mixture type of almond shells follows the Langmuir non-linear isotherm. Furthermore, the experimental data by internal and external almond shells could be well described by the BET and Freundlich isotherm models, respectively. The pseudo-second-order kinetics provides the best correlation of the experimental data. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Isotherms, Almond Shells, Anionic Dyes, Aqueous Solution, Basic Dye, BET, Capacity, Changes, Direct Red 80 (DR 80), Dye, Efficiency, Equilibrium, Experimental, Experiments, Fly-Ash, Freundlich, Freundlich Isotherm, Hydrogen-Peroxide, Industry Waste, Isotherm, Isotherms, Kinetics, Langmuir, Methylene-Blue, Models, pH, Pseudo-Second-Order Kinetics, Removal, Rights, Solution, Sorption, Textile Waste-Water

? Sharma, Y.C., Singh, B., Agrawal, A. and Weng, C.H. (2008), Removal of chromium by riverbed sand from water and wastewater: Effect of important parameters. Journal of Hazardous Materials, 151 (2-3), 789-793.

Full Text: 2008\J Haz Mat151, 789.pdf

Abstract: Application of riverbed sand, a non-toxic substance for the removal of Cr(VI) for aqueous solutions has been investigated. Removal of Cr(VI) was dependent on initial concentration and removal increased from 43.2% to 74.3% by decreasing initial concentration from 7.510^-5 M to 1.010^-5 M at 25C, 1.010^-2 M NaClO₄ ionic strength and 100 rpm. Higher removal was obtained at particles of smaller sizes of the adsorbent. Removal decreased from 74.3% to 40.7% by increasing temperature from 25C to 35C exhibiting exothermic nature of the process of removal. Thermodynamic parameters, namely change in free energy (G), enthalpy (H) and entropy (S), were calculated and were found to be -0.81 kcal mol^-1, -17.21 kcal mol^-1 and 56.94 cal mol^-1, respectively at 25C. pH of the solution has pronounced effect on the removal and higher removal was obtained in acidic pH ranges, maximum (74.3%) being at 2.5 pH. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Riverbed Sand, Removal, Cr(VI), pH, Temperature, Industrial-Waste, Adsorption, Adsorbents, Sorption

? Kumar, K.V., Porkodi, K. and Rocha, F. (2008), Isotherms and thermodynamics by linear and non-linear regression analysis for the sorption of Methylene blue onto activated carbon: Comparison of various error functions. Journal of Hazardous Materials, 151 (2-3), 794-804.

Full Text: 2008\J Haz Mat151, 794.pdf

Abstract: A comparison of linear and non-linear regression method in selecting the optimum isotherm was made to the experimental equilibrium data of methylene blue sorption by activated carbon. The r(2) was used to select the best fill linear theoretical isotherm. In the case of non-linear regression method, six error functions, namely coefficient of determination (r(2)), hybrid fractional error function (HYBRID), Marquardt’s percent standard deviation (MPSD), average relative error (ARE), sum of the errors squared (ERRSQ) and sum of the absolute errors (EABS) were used to predict the parameters involved in the two and three parameter isotherms and also to predict the optimum isotherm. For two parameter isotherm, MPSD was found to be the best error function in minimizing the error distribution between the experimental equilibrium data and predicted isotherms. In the case of three parameter isotherm, r2 was found to be the best error function to minimize the error distribution structure between experimental equilibrium data and theoretical isotherms. The present study showed that the size of the error function alone is not a deciding factor to choose the optimum isotherm. In addition to the size of error function, the theory behind the predicted isotherm should be verified with the help of experimental data while selecting the optimum isotherm. A coefficient of non-determination, K-2 was explained and was found to be very useful in identifying the best error function while selecting the optimum isotherm. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Analysis, Carbon, Comparison, Data, Determination, Distribution, Equilibrium, Error, Error Function, Errors, Experimental, Function, Functions, Hybrid, Isotherm, Isotherms, Linear Regression, Methylene Blue, Non-Linear Regression, Nonlinear Regression, Regression, Regression Analysis, Size, Sorption, Standard, Structure, Theory, Thermodynamics, Three Parameter Isotherm, Two Parameter Isotherm

? Maji, S.K., Pal, A. and Pal, T. (2008), Arsenic removal from real-life groundwater by adsorption on laterite soil. Journal of Hazardous Materials, 151 (2-3), 811-820.

Full Text: 2008\J Haz Mat151, 811.pdf

Abstract: The adsorption characteristics of arsenic on laterite soil, a low-cost natural adsorbent, were studied in the laboratory scale using real-life sample. The studies were conducted by both batch and continuous mode. Laterite soil was found to be an efficient adsorbent for arsenic removal from the groundwater collected from arsenic affected area. The initial concentration of arsenic in the sample was 0.33 ppm. Under optimized conditions the laterite soil could remove up to 98% of total arsenic. The optimum adsorbent dose was 20 g/l and the equilibrium time was 30 min. Isotherm studies showed that the process is favorable and spontaneous. The kinetics showed that the removal of arsenic by laterite soil is a pseudo-second-order reaction. In the column study the flow rate was maintained at 1.49 m³/(m² h). Using 10 cm column depth, the breakthrough and exhaust time found were 6.75 h and 19.0 h, respectively. Height of adsorption zone was 9.85 cm, the rate at which the adsorption zone was moving through the bed was 0.80 cm/h, and the percentage of the total column saturated at breakthrough was 47.12%. The value of adsorption rate coefficient (K) and the adsorption capacity coefficient (N) were 1.21 l/(mg h) and 69.22 mg/l, respectively. Aqueous NaOH (1 M) could regenerate the adsorbent, and the regenerated adsorbent showed higher efficiency. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorbent Dose, Adsorption, Adsorption Capacity Coefficient, Adsorption Isotherm, Adsorption Rate Coefficient, Alumina, Aqueous-Solution, Arsenic, Arsenic Removal, As(III), As(V), Capacity, Column Study, Efficiency, Equilibrium, Groundwater, Hydroxide, Isotherm, Kinetics, Laterite, Laterite Soil, Loaded Coral Limestone, Model, Natural Adsorbent, Rate-Limiting Step, Reaction Kinetics, Real-Life Groundwater, Removal, Rights, Soil, Water

? Mittal, A., Gupta, V.K., Malviya, A. and Mittal, J. (2008), Process development for the batch and bulk removal and recovery of a hazardous, water-soluble azo dye (Metanil Yellow) by adsorption over waste materials (Bottom Ash and De-Oiled Soya). Journal of Hazardous Materials, 151 (2-3), 821-832.

Full Text: 2008\J Haz Mat151, 821.pdf

Abstract: Bottom Ash and De-Oiled Soya have been used as adsorbents for the removal of a hazardous azo dye-Metanil Yellow from its aqueous solutions. Adsorption of Metanil Yellow on these adsorbents has been studied as function of time, temperature, concentration and pH. Batch adsorption studies, kinetic studies and column operations enabled extraction of lethal dye from wastewaters. Adsorption equilibrium data confirms both Langmuir and Freundlich isotherm models and monolayer coverage of dye over adsorbents. Kinetic data have been employed to calculate specific rate constants, indicating thereby involvement of first order kinetics in the on-going adsorption and activation energy was determined as 0.813 and 1.060 kJ mol^-1 for Bottom Ash and De-Oiled Soya, respectively. For both adsorbents, the adsorption process has been found governing by film diffusion, over the entire concentration range. Column operations have also been performed for the bulk removal of the dye and also to examine the practical utilization of fixed bed adsorption technique in elimination of dangerous effluent. Saturation factors for Bottom Ash and De-Oiled Soya columns have been calculated as 99.15 and 99.38%, respectively. Attempts have also been made to regenerate the dye from the exhausted columns using aqueous sodium hydroxide as eluent. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activation, Activation Energy, Adsorbents, Adsorption, Adsorption Equilibrium, Adsorption Process, Aqueous Solutions, Azo Dye, Batch, Batch Adsorption, Bottom Ash, Column, Concentration, Coverage, Data, De-Oiled Soya, Development, Diffusion, Dye, Energy, Equilibrium, Extraction, Film Diffusion, First, First Order, Fixed Bed, Fixed Bed Adsorption, Freundlich, Freundlich Isotherm, Function, Isotherm, Kinetic, Kinetic Studies, Kinetics, Langmuir, Metanil Yellow, Models, Monolayer, pH, Rate Constants, Recovery, Removal, Sodium, Solutions, Temperature, Utilization, Waste, Waste Materials, Wastewaters

? Fu, L., Wang, H.Y., Lu, H.X., Su, W. and Ren, A.J. (2008), Comment on “The removal of phenolic compounds from aqueous solutions by organophilic bentonite”. Journal of Hazardous Materials, 151 (2-3), 851-854.

Full Text: 2008\J Haz Mat151, 851.pdf

Abstract: Quotation and calculation accuracy can play a key role in a scientific paper. This comment mainly presents the possible errors in an article by Akqay et al., including the questionable expression of Polanyi potential (epsilon) in the Dubinin-Radushkevich (DR) equation used by the authors and the discrepancies in adsorption thermodynamic parameters study. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Accuracy, Activated Carbon, Adsorption, Adsorption Potential Theory, Aqueous Solutions, Authors, Calculation, Comment on, Dr Equation, Errors, Expression, Isotherms, Kinetics, Mar, Miscible Organic Liquids, Natural Sorbent, Potential, Quotation Errors, Removal, Rights, Role, Solutions, Sorption, Surfactant-Modified Montmorillonite, Thermodynamic, Thermodynamic Parameters, Thermodynamics, Water Solution

? Elangovan, R., Philip, L. and Chandraraj, K. (2008), Biosorption of chromium species by aquatic weeds: Kinetics and mechanism studies. Journal of Hazardous Materials, 152 (1), 100-112.

Full Text: 2008\J Haz Mat152, 100.pdf

Abstract: In this paper, we have presented the results of Cr(VI) and Cr(III) removal from aqueous phase by different aquatic weeds as biosorbents. Batch kinetic and equilibrium experiments were conducted to determine the adsorption kinetic rate constants and maximum adsorption capacities of selected biosorbents. In most of the cases, adsorption followed a second-order kinetics. For Cr(III), maximum adsorption capacity was exhibited by reed mat (7.18 mg/g). In case of Cr(VI), mangrove leaves showed maximum removallreduction capacity (8.87 mg/g) followed by water lily (8.44 mg/g). There was a significant difference in the concentrations of Cr(VI) and total chromium removed by the biosorbents. In case of Cr(VI) removal, first it was reduced to Cr(III) with the help of tannin, phenolic compounds and other functional groups on the biosorbent and subsequently adsorbed. Acid treatment significantly increased Cr(VI) removal capacity of the biosorbents whereas, alkali treatment reduced the Cr(VI) removal capacities of the biosorbents. FTIR spectrum showed the changes in functional groups during acid treatment and biosorption of Cr(VI) and Cr(III). Aquatic weeds seem to be a promising biosorbent for the removal of chromium ions from water environment. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Acid and Alkali Treatment, Activated Carbons, Adsorption, Adsorption Kinetic, Aquatic Weeds, Aqueous-Solution, Biosorbent, Biosorption, Capacity, Changes, Chromium, Cr(III), Cr(VI), Dead Fungal Biomass, Environment, Equilibrium, Experiments, First, FTIR, Heavy-Metal Biosorption, Hexavalent Chromium, Hexavalent Chromium, Kinetic, Kinetic Studies, Kinetics, Mechanism, Reed, Removal, Rice Husk, Rights, Second-Order Kinetics, Tannin Gel, Treatment, Trivalent Chromium, Waste-Waters, Water

? Ghodbane, I., Nouri, L., Hamdaoui, O. and Chiha, M. (2008), Kinetic and equilibrium study for the sorption of cadmium(II) ions from aqueous phase by eucalyptus bark. Journal of Hazardous Materials, 152 (1), 148-158.

Full Text: 2008\J Haz Mat152, 148.pdf

Abstract: The efficiency of eucalyptus bark as a low cost sorbent for removing cadmium ions from aqueous solution has been investigated in batch mode. The equilibrium data could be well described by the Langmuir isotherm but a worse fit was obtained by the Freundlich model. The five linearized forms of the Langmuir equation as well as the non-linear curve fitting analysis method were discussed. Results show that the non-linear method may be a better way to obtain the Langmuir parameters. Maximum cadmium uptake obtained at a temperature of 20C was 14.53 mg g^-1. The influence of temperature on the sorption isotherms of cadmium has been also studied. The monolayer sorption capacity increased from 14.53 to 16.47 when the temperature was raised from 20 to 50C. The G values were negative, which indicates that the sorption was spontaneous in nature. The effect of experimental parameters such as contact time, cadmium initial concentration, sorbent dose, temperature, solution initial pH, agitation speed, and ionic strength on the sorption kinetics of cadmium was investigated. Pseudo-second-order model was evaluated using the six linear forms as well as the non-linear curve fitting analysis method. Modeling of kinetic results shows that sorption process is best described by the Pseudo-second-order model using the non-linear method. The pseudo-second-order model parameters were function of the initial concentration, the sorbent dose, the solution pH, the agitation speed, the temperature, and the ionic strength. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Agricultural Waste, Analysis, Aqueous Solution, Cadmium, Cadmium(II), Cadmium(II), Cadmium(II) Ions, Capacity, Carbons, Component Adsorption, Cost, Efficiency, Equilibrium, Eucalyptus Bark, Experimental, Freundlich, Function, Heavy-Metals, Isotherm, Isotherms, Kinetic, Kinetics, Langmuir, Langmuir Equation, Langmuir Isotherm, Linear Analysis, Model, Modeling, Monolayer, Non-Linear Analysis, pH, Pseudo-Second-Order, Pseudo-Second-Order Model, Removal, Rights, Single, Solution, Sorption, Sorption Isotherms, Sorption Kinetics, Sorption Process, Temperature, Water, Zinc

? Xiong, J.B., He, Z.L., Mahmood, Q., Liu, D., Yang, X. and Islam, E. (2008), Phosphate removal from solution using steel slag through magnetic separation. Journal of Hazardous Materials, 152 (1), 211-215.

Full Text: 2008\J Haz Mat152, 211.pdf

Abstract: Steel slag with magnetic separation was used to remove phosphate from aqueous solutions. The influence of adsorbent dose, pH, and temperature on phosphate removal was investigated in a series of batch experiments. Phosphate removal increased with the increasing temperature, adsorbent dose and decreased with increasing initial phosphate concentrations, while it was at its peak at pH of 5.5. The phosphate removal predominantly occurred through ion exchange. The specific surface area of the steel slag was 2.09 m(2)/g. The adsorption of phosphate followed both Langmuir and Freundlich isotherms. The maximum adsorption capacity of the steel slag was 5.3 mg P/g. The removal rates of total phosphorus (TP) and dissolved phosphorus (DP) from secondary effluents were 62-79% and 71-82%, respectively. Due to their low cost and high capability, it was concluded that the steel slag may be an efficient adsorbent to remove phosphate both from solution and wastewater. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activated Alumina, Adsorbent, Adsorption, Adsorption, Aqueous-Solutions, Blast-Furnace Slags, Dyes, Fly-Ash, Iron, Isotherm, Isotherms, Langmuir and Freundlich Isotherms, Magnetic Separation, pH, Phosphate, Phosphorus Removal, Phosphorus Removal, Soils, Steel Slag, Waste-Water, Wastewater

? Lee, I.H., Kuan, Y.C. and Chern, J.M. (2008), Prediction of ion-exchange column breakthrough curves by constant-pattern wave approach. Journal of Hazardous Materials, 152 (1), 241-249.

Full Text: 2008\J Haz Mat152, 241.pdf

Abstract: The release of heavy metals from industrial wastewaters represents one of major threats to environment. Compared with chemical precipitation method, fixed-bed ion-exchange process can effectively remove heavy metals from wastewaters and generate no hazardous sludge. In order to design and operate fixed-bed ion-exchange processes successfully, it is very important to understand the column dynamics. In this study, the column experiments for Cu²⁺/H⁺, Zn²⁺/H⁺, and Cd²⁺/H⁺ systems using Amberlite IR-120 were performed to measure the breakthrough curves under varying operating conditions. The experimental results showed that total cation concentration in the mobile-phase played a key role on the breakthrough curves; a higher feed concentration resulted in an earlier breakthrough. Furthermore, the column dynamics was also predicted by self-sharpening and constant-pattern wave models. The self-sharpening wave model assuming local ion-exchange equilibrium could provide a simple and quick estimation for the breakthrough volume, but the predicted breakthrough curves did not match the experimental data very well. On the contrary, the constant-pattern wave model using a constant driving force model for finite ion-exchange rate provided a better fit to the experimental data. The obtained liquid-phase mass transfer coefficient was correlated to the flow velocity and other operating parameters; the breakthrough curves under varying operating conditions could thus be predicted by the constant-pattern wave model using the correlation. (c) 2007 Elsevier B.V. All rights reserved.

Keywords: Column Dynamics, Constant-Pattern Wave, Heavy Metal, Ion-Exchange Resin, Fixed-Bed Adsorption, Granular Activated Carbon, Aqueous-Solutions, Heavy-Metals, Waste-Water, Removal, Batch, Adsorbent, Zeolites, Lead(II)

? El Nemr, A., Khaled, A., Abdelwahab, O. and El-Sikaily, A. (2008), Treatment of wastewater containing toxic chromium using new activated carbon developed from date palm seed. Journal of Hazardous Materials,