Personal Research Database

Full Text: 2009\J Haz Mat171, 973.pdf

Abstract: This paper presents the equilibrium, thermodynamic and kinetic studies on aluminum biosorption from aqueous solution by brown algae (Padina pavonica) biomass. Optimum biosorption conditions were determined as a function of pH, biomass dosage, contact time, and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of Al(III) by P. pavonica biomass. The biosorption capacity of P. pavonica biomass was found as 77.3 mg/g. The metal ions were desorbed from P. pavonica using 1 M HCl. The high stability of P. pavonica permitted a slight decrease about 20% in the recovery of Al(III) ions after 10 times of adsorption-elution process. The mean free energy value evaluated from the D-R model indicated that the biosorption of Al(III) onto P. pavonica biomass was taken place by chemical ion exchange. The calculated thermodynamic parameters, Delta G degrees, Delta H degrees, and Delta S degrees, showed that the biosorption of Al(III) onto P. pavonica biomass was feasible, spontaneous and endothermic under examined conditions. Experimental data was also tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. The results showed that the biosorption processes of Al(III) onto P. pavonica biomass followed well pseudo-second-order kinetics. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Absorption Spectrometric Determination, Activated Carbons, Adsorption, Algae, Aluminum, Aqueous Solution, Biomass, Biosorption, Biosorption Isotherm, Biosorption Kinetics, Brown Algae, Capacity, Chemical, Copper, Data, Endothermic, Energy, Equilibrium, Freundlich, Function, Heavy-Metals, Ion Exchange, Ion-Exchange, Ions, Isotherm, Kinetic, Kinetic Models, Kinetic Studies, Kinetics, Langmuir, Lead, Marine-Algae, Metal, Metal Ions, Model, Models, NOV, P, P.Pavonica, pH, Pseudo First Order, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetics, Pseudomonas-Aeruginosa, Recovery, Removal, Rights, Solution, Sorption, Spontaneous, Stability, Temperature, Thermodynamic, Thermodynamic Parameters, Thermodynamics, Value

? Hsu, T.C. (2009), Experimental assessment of adsorption of Cu²⁺ and Ni²⁺ from aqueous solution by oyster shell powder. Journal of Hazardous Materials, 171 (1-3), 995-1000.

Full Text: 2009\J Haz Mat171, 995.pdf

Abstract: In this study, I found that oyster shell powder (OSP) can effectively adsorb Cu²⁺ and Ni²⁺ from wastewater, with the adsorption capacity being higher for the former ion. The isotherms for the adsorption of Cu²⁺ and Ni²⁺ on the OSP fitted the Langmuir, Freundlich, and Dubinin-Kaganer-Radushkevich isotherms quite well (R-2 = 0.949-0.984, 0.912-0.988 and 0.900-0.990, respectively). Positive values of Delta H degrees, and Delta S degrees, indicated that these adsorptions were endothermic in nature; the values of E (between 1.722 and 3.553 kJ mol^-1) were consistent with a physical adsorption mechanism. Moreover, the adsorptions of Cu²⁺ and Ni²⁺ on the OSP followed pseudo-second-order kinetics. The adsorption capacities of the OSP toward Cu²⁺ and Ni²⁺ were 49.26-103.1 and 48.75-94.3 mg g^-1, respectively. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Capacities, Adsorption Capacity, Adsorption Mechanism, Aqueous Solution, Assessment, Bagasse Fly-Ash, Capacity, Copper, Cu²⁺, Endothermic, Freundlich, Heavy-Metals, Ions, Isotherms, Kinetics, Langmuir, Mechanism, Montmorillonite, Ni²⁺, NOV, Oyster Shell Powder, Physical, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second-Order, Pseudo-Second-Order Kinetics, Removal, Rights, Sewage-Sludge, Solution, Sugar-Industry Waste, Thermodynamics, Wastewater, Water

? Benhamou, A., Baudu, M., Derriche, Z. and Basly, J.P. (2009), Aqueous heavy metals removal on amine-functionalized Si-MCM-41 and Si-MCM-48. Journal of Hazardous Materials, 171 (1-3), 1001-1008.

Full Text: 2009\J Haz Mat171, 1001.pdf

Abstract: Ordered mesoporous silica with hexagonal and cubic structure, type MCM-41 and MCM-48 respectively, were synthesized under basic media using pure silica, cetyltrimethylammonium bromide and tetramethylammonium hydroxide, for MCM-41 and tetraethylorthosilica, cetyltrimethylammonium and NaOH for MCM-48. The expanded materials were prepared by post-synthesis method with N-N dimethyldodecylamine (DMDDA) and dodecylamine (DDA). Small angle X-ray diffraction, nitrogen adsorption-desorption measurements, FT-IR and thermogravimetry were used to characterize the samples. The expanded materials were tested for adsorption of Cd²⁺, Co²⁺, Cu²⁺, and Pb²⁺ in aqueous solution. Aminated materials were found to be fast adsorbents for metallic ions cation with affinity for Cu²⁺, Pb²⁺, than for Cd²⁺ and Co²⁺ from single solution. In mixed metallic ions cation solutions, competition by the adsorption sites is likely to occur, the adsorption preference is for Cu²⁺ and Pb²⁺. The kinetic of the reaction is very rapid and follow pseudo-second order and clearly indicated that Langmuir model describe better the for metal ions adsorption on aminated mesoporous material than Freundlich model. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbents, Adsorption, Adsorption-Desorption, Amine, Aqueous Solution, Bromide, Cation, Cd²⁺, Co²⁺, Competition, Cu²⁺, Expansion, Freundlich, Freundlich Model, FT-IR, FTIR, Heavy Metals, Hydroxide, Ions, Ions Adsorption, Kinetic, Langmuir, Langmuir Model, MCM-41, Mcm-48, Media, Mesoporous, Mesoporous Material, Mesoporous Materials, Mesoporous Silica, Metal, Metal Ions, Metals, Metals Removal, Model, Molecular-Sieves, NaOH, Nitrogen, NOV, Pb²⁺, Preference, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second-Order, Remediation, Removal, Rights, SBA-15, Si-MCM-41, Silica, Solution, Solutions, Sorbents, Sorption, Structure, Thermogravimetry, Waste-Water, X-Ray, X-Ray Diffraction

? Goyal, M., Bhagat, M. and Dhawan, R. (2009), Removal of mercury from water by fixed bed activated carbon columns. Journal of Hazardous Materials, 171 (1-3), 1009-1015.

Full Text: 2009\J Haz Mat171, 1009.pdf

Abstract: The breakthrough curves for Hg(II) ions on a sample of granulated activated carbon (GAC) and a sample of activated carbon cloth (ACC) are generally S-shaped. The breakthrough time increases with increase in the bed depth but decreases on increasing the hydraulic loading rate (HLR) and the feed concentration. The adsorption of Hg(II) ions increases with HLR and attains a maximum value at HLR around 7 m³/h/m². At low HLR, laminar flow conditions prevail so that the mass transfer takes place across a nearly stationary film of the liquid covering the carbon particles. This high resistance leads to low mass transfer and results in smaller adsorption. On increasing HLR, the interface resistance decreases resulting in an increase in adsorption. Beyond a certain HLR, the rate of adsorption decreases due to decrease in the residence time of the solution within the carbon bed and a lower time available for mass transfer. The adsorption zone parameters of the carbon column have been determined using the carbon bed column data and invoking the mathematical treatment suggested by Michaels. Bed Depth Service Time (BDST) theoretical model has been used to calculate the critical bed depth and the depth of the mass transfer zone. These have been found to be in agreement with the experimental values. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption, Adsorption Zone, Aqueous-Solution, BDST Model, Cadmium(II), Carbon, Charcoal, Chloride, Critical Bed Depth, Elsevier, Fixed-Bed, Hg(II), Hg(II) Ions, Mass Transfer, Mercury, Particles, Removal, Sorption, Treatment, Water

? Repo, E., Kurniawan, T.A., Warchol, J.K. and Sillanpää, M.E.T. (2009), Removal of Co(II) and Ni(II) ions from contaminated water using silica gel functionalized with EDTA and/or DTPA as chelating agents. Journal of Hazardous Materials, 171 (1-3), 1071-1080.

Full Text: 2009\J Haz Mat171, 1071.pdf

Abstract: In this study, the removal of Co(II) and Ni(II) ions from contaminated water was investigated using silica gel materials functionalized with both ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA). The modified adsorbents were characterized using elemental analysis, surface area and pore size analysis, and zeta potential analysis. The adsorption and regeneration studies were conducted in batch mode. The optimum conditions for the removal of both metals at an initial concentration of 10 mg/L were 2 g/L of dose, pH 3, 50 rpm of agitation speed and 4 h of contact time. The removal of Co(II) and Ni(II) by EDTA- and/or DTPA-modified silica gels was substantially higher than that by their unmodified form. The maximum Co(II) and Ni(II) uptakes by the EDTA-modified silica gel were 20.0 and 21.6 mg/g, comparable to their adsorption capacities by DTPA-modified silica gel (Co(II): 16.1 mg/g; Ni(II): 16.7 mg/g). At the same concentration of 10 mg/L, the removal of both metals by the modified adsorbents ranged from 96% to 99%. The two-site Langmuir model was representative to simulate adsorption isotherms. The kinetics of Co(II) and Ni(II) adsorption by modified silica gels followed pseudo-second-order. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbents, Adsorption, Adsorption, Adsorption Capacities, Adsorption Isotherms, Agitation, Analysis, Batch, Batch Mode, Chemically-Modified Chitosan, Co(II), Co(II) and Ni(II), Concentration, EDTA, Environmental Protection, Equilibrium, Gel, Heavy Metal Removal, Ions, Isotherms, Kinetics, Langmuir, Langmuir Model, Metal-Ions, Metals, Mode, Model, Modified, Ni(II), Ni(II) Ions, NOV, Peat, pH, Potential, Pseudo Second Order, Pseudo-Second-Order, Recovery, Regeneration, Removal, Resins, Rights, Separation, Silica, Silica Gel, Size, Surface, Surface Area, Surface Modification, Waste-Water, Wastewater Treatment, Water, Zeta Potential

? Deiana, A.C., Sardella, M.F., Silva, H., Amaya, A. and Tancredi, N. (2009), Use of grape stalk, a waste of the viticulture industry, to obtain activated carbon. Journal of Hazardous Materials, 172 (1), 13-19.

Full Text: 2009\J Haz Mat172, 13.pdf

Abstract: Grape stalk is an organic waste produced in great amounts in the industrialization processes of grape. This work presents the results of studies carried out to use this waste as raw material to prepare activated carbon through the physical and chemical route. The physicochemical characterization of this material suggests the presence of unusually high levels of ashes. Metal content was determined and high levels of potassium, sodium, iron, calcium and magnesium in carbonized and raw grape stalk were exhibited. This characteristic made difficult physical activation at high temperatures. A leaching step was included before the activation with steam, and adsorbents with surface areas between 700 and 900 m²/g were obtained. Physical activation was also performed at lower temperatures using carbonized grape stalk without leaching, leading to the development of some grade of porosity, with an area of 472 m²/g. These results would indicate the catalytic effect of the minerals present in this raw material. Chemical activation using phosphoric acid as activating agent seemed to be a very efficient method as final products with BET areas between 1000 and 1500 m²/g were obtained. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Activation, Carbon, Chemical Activation, Connectivity, Elsevier, Extraction, Grape Stalk, Industrialization, Leaching, Magnesium, Nitrogen Sorption Measurements, Physical Activation, Porous Solids, Sodium

? Wang, Y., Tang, X.W., Chen, Y.M., Zhan, L.T., Li, Z.Z. and Tang, Q. (2009), Adsorption behavior and mechanism of Cd(II) on loess soil from China. Journal of Hazardous Materials, 172 (1), 30-37.

Full Text: 2009\J Haz Mat172, 30.pdf

Abstract: Cadmium is a toxic heavy metal that has caused serious public health problems. It is necessary to find a cost effective method to deal with wastewater containing Cd(II). Loess soils in China have proven to be a potential adsorbent for Cd(II) removal from wastewater. The adsorption capacity of loess towards Cd(II) has been determined to be about 9.37 mg g^-1. Slurry concentration, initial solution pH, reaction time and temperature have also been found to significantly influence the efficiency of Cd(II) removal. The adsorption isotherms and kinetics of loess soil from China can be best-fit with the Langmuir model and pseudo-second order kinetics model, respectively. The thermodynamic analysis revealed that the adsorption process was spontaneous, endothermic and the system disorder increased with duration. The natural organic matter in loess soil is mainly responsible for Cd(II) removal at pH < 4.2, while clay minerals contribute to a further gradual adsorption process. Chemical precipitation dominates the adsorption stage at pH > 8.97. Further studies using X-ray diffraction, Fourier transform infrared spectra of Cd(II) laden loess soil and Cd(II) species distribution have confirmed the adsorption mechanism. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Adsorption Isotherms, Adsorption Mechanism, Analysis, Aqueous-Solutions, Behavior, Cadmium, Cadmium Ions, Capacity, Cd(II), Cd(II) Removal, China, Clay, Clay Minerals, Concentration, Cost, Cost-Effective, Distribution, Duration, Efficiency, Endothermic, Equilibrium, Granular Activated Carbon, Health, Heavy Metal, Heavy-Metal Ions, Isotherm, Isotherms, Kaolinite, Kinetics, Kinetics, Kinetics Model, Langmuir, Langmuir Model, Loess, Mechanism, Metal, Minerals, Model, Natural, Organic, Organic Matter, pH, Potential, Precipitation, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second Order, Pseudo-Second Order Kinetics, Pseudo-Second-Order, Public, Public Health, Removal, Rights, Soil, Soils, Solution, Sorption, Species, Spontaneous, Temperature, Thermodynamic, Thermodynamics, Toxic, Waste, Wastewater, X-Ray, X-Ray Diffraction

? Chou, W.L. and Huang, Y.H. (2009), Electrochemical removal of indium ions from aqueous solution using iron electrodes. Journal of Hazardous Materials, 172 (1), 46-53.

Full Text: 2009\J Haz Mat172, 46.pdf

Abstract: The removal of indium ions from aqueous solution was carried out by electrocoagulation in batch mode using an iron electrode. Various operating parameters that could potentially affect the removal efficiency were investigated, including the current density, pH variation, supporting electrolyte, initial concentration, and temperature. The optimum current density, supporting electrolyte concentration, and temperature were found to be 6.4 mA/cm(2), 0.003N NaCl, and 298 K, respectively. When the pH values lower than 6.1, the removal efficiencies of indium ions via electrocoagulation were up to 5 times greater than those by adding sodium hydroxide. The indium ion removal efficiency decreased with an increase in the initial concentration. Results for the indium ion removal kinetics at various current densities show that the kinetic rates conformed to the pseudo-second-order kinetic model with good correlation. The experimental data were also tested against different adsorption isotherm models for describing the electrocoagulation process. The adsorption of indium ions preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of adsorbed molecules. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Isotherm, Adsorption Isotherm Models, Adsorption Isotherms, Aluminum, Aqueous Solution, Batch, Batch Mode, Concentration, Correlation, Coverage, Data, Efficiency, Electrocoagulation, Electrocoagulation, Experimental, Extraction, Flotation, Gallium, Hydroxide, Indium Ion Removal, Ions, Iron, Iron Electrode, Isotherm, Isotherm Models, Kinetic, Kinetic Model, Kinetics, Langmuir, Langmuir Adsorption Isotherm, Mode, Model, Models, Monolayer, NaCl, pH, Phosphate, Plate Electrodes, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Rates, Removal, Removal Efficiency, Rights, Separation, Sodium, Solution, Specific Energy Consumption, Temperature, Waste-Water Treatment, Zn(II)

? Shen, D.Z., Fan, J.X., Zhou, W.Z., Gao, B.Y., Yue, Q.Y. and Kang, Q. (2009), Adsorption kinetics and isotherm of anionic dyes onto organo-bentonite from single and multisolute systems. Journal of Hazardous Materials, 172 (1), 99-107.

Full Text: 2009\J Haz Mat172, 99.pdf

Abstract: The performances of polydiallydimethylammonium modified bentonite (PDADMA-bentonite) as an adsorbent to remove anionic dyes, namely Acid Scarlet GR (AS-GR), Acid Turquoise Blue 2G (ATB-2G) and Indigo Carmine (IC), were investigated in single, binary and ternary dye systems. In adsorption from single dye solutions with initial concentration of 100 mu mol/L, the dosage of PDADMA-bentonite needed to remove 95% dye was 0.42, 0.68 and 0.75 g/L for AS-GR, ATB-2G and IC, respectively. The adsorption isotherms of the three dyes obeyed the Langmuir isotherm model with the equilibrium constants of 0.372, 0.629 and 4.31 L/mu mol, the saturation adsorption amount of 176.3, 149.2 and 228.7 mu mol/g for ATB-2G, IC and AS-GR, respectively. In adsorption from mixed dye solutions, the isotherm of each individual dye followed an expanded Langmuir isotherm model and the relationship between the total amount of dyes adsorbed and the total equilibrium dye concentration was interpreted well by Langmuir isotherm model. In the region of insufficient dosage of PDADMA-bentonite, the dye with a larger affinity was preferentially removed by adsorption. Desorption was observed in the kinetic curve of the dye with lower affinity on PDADMA-bentonite surface by the competitive adsorption. The kinetics in single dye solution and the total adsorption of dyes in binary and ternary dye systems nicely followed pseudo-second-order kinetic model. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Isotherm, Adsorption Isotherms, Adsorption Kinetics, Adsorption Kinetics and Isotherm, Anionic Dyes, Aqueous-Solution, Bentonite, Cation-Exchange, Competitive, Competitive Adsorption, Concentration, Desorption, Disperse Dyes, Dye, Dyes, Equilibrium, Indigo, Isotherm, Isotherm Model, Isotherms, Kinetic, Kinetic Model, Kinetics, Langmuir, Langmuir Isotherm, Langmuir Isotherm Model, Methylene-Blue, Mixed Dyes, Model, Modified, Organo-Bentonite, Organobentonite, Photo-Fenton Oxidation, Plant Effluent, Polyelectrolyte, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Reactive Dyes, Rights, Saturation, Solution, Solutions, Surface, Surfactant-Modified Bentonite, Systems, Textile Waste-Water

? Naeem, A., Saddique, M.T., Mustafa, S., Tasleem, S., Shah, K.H. and Waseem, M. (2009), Removal of Co²⁺ ions from aqueous solution by cation exchange sorption onto NiO. Journal of Hazardous Materials, 172 (1), 124-128.

Full Text: 2009\J Haz Mat172, 124.pdf

Abstract: Batch adsorption technique was used to study the adsorption of cobalt on NiO. The aim of this work was to examine the effect of pH, concentration and temperature on the ion exchange removal of Co²⁺ from aqueous solution by the NiO surface. We used Langmuir model to interpret the adsorption data. The Kurbatov-type plots were tested to determine the adsorption mechanism. The kinetics of Co²⁺ adsorption on NiO was best described by film diffusion model. A well-known thermodynamic equation was used to assess the enthalpy and entropy of the system. The thermodynamic data were indicative of the spontaneous nature of the endothermic sorption process of Co²⁺ onto the NiO. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Acid, Adsorption, Adsorption Mechanism, Aqueous, Cation Exchange, Co(II), Cobalt, Copper, Diffusion, Divalent Metal-Ions, Elsevier, Endothermic, Ion Exchange, Kaolinite, Kinetics, Mechanism, Metal Oxide, Ni(II), Nickel, NiO, Oxides, pH, Removal, Sorption, System, Temperature, Thermodynamic

? Thakkar, R. and Chudasama, U. (2009), Synthesis and characterization of zirconium titanium phosphate and its application in separation of metal ions. Journal of Hazardous Materials, 172 (1), 129-137.

Full Text: 2009\J Haz Mat172, 129.pdf

Abstract: An advanced inorganic ion exchanger, zirconium titanium phosphate (ZTP) of the class of tetravalent bimetallic acid (TBMA) salt has been synthesized by sol-gel route. ZTP has been characterized for ICP-AES, TGA, FTIR and XRD. Chemical stability of the material in various media-acids, bases and organic solvents has been assessed. Cation exchange capacity (CEC) and effect of calcination (100-500 degrees C) on CEC has also been studied. Distribution behaviour of metal ions Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ (d-block), Cd²⁺, Hg²⁺, Pb²⁺, Bi³⁺ (heavy) and La³⁺, Ce³⁺, Th⁴⁺, UO₂²⁺ (f-block) towards ZTP has been studied and distribution coefficient (K-d) determined in aqueous as well as various electrolyte media/concentrations. Based on the differential selectivity, breakthrough capacity (BTC) and elution behaviour of various metal ions towards ZTP, a few binary and ternary metal ion separations have been carried out. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.

Keywords: Acid Salts, Aqueous, Arsenate, Behavior, Calcination, Capacity, Cation Exchange, Cation Exchanger, Cation-Exchanger, Cu²⁺, Distribution Coefficient, Elsevier, Exchange Properties, FTIR, Metal, Metal Ions, Metal Separation, Mixed Material, Phase, Phosphate, Sol-Gel, Sorption, Tetravalent Bimetallic Acid Salt, Tin(IV), Titanium, Zirconium Titanium Phosphate, Zn²⁺

? Sundaram, C.S., Viswanathan, N. and Meenakshi, S. (2009), Fluoride sorption by nano-hydroxyapatite/chitin composite. Journal of Hazardous Materials, 172 (1), 147-151.

Full Text: 2009\J Haz Mat172, 147.pdf

Abstract: In this study the fluoride adsorption potential of novel nano-hydroxyapatite/chitin (n-HApCh) composite was explored. The sorbent was characterized using FTIR studies. The effects of pH, interfering anions and contact time were studied. The sorption data obtained under optimized conditions were subjected to Langmuir and Freundlich isotherms. Kinetic studies indicate that the rate of sorption of fluoride on n-HApCh composite follows pseudo-second-order and pore diffusion patterns. n-HApCh composite possesses higher defluoridation capacity (DC) of 2840 mg F^- kg^-1 than nano-hydroxyapatite (n-HAp) which showed a DC of 1296 mgF^- kg^-1. Field trials were conducted with the sample collected from a nearby fluoride endemic area. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption, Anions, Capacity, Chemistry, Chitin, Chitin, Composite, Data, Dc, Defluoridation, Diffusion, Equilibrium, Fluoride, Fluoride Adsorption, Fluoride Removal, Freundlich, Freundlich Isotherms, FTIR, FTIR Studies, Hydroxyapatite, Ion Exchange, Isotherms, Kinetic, Kinetic Studies, Kinetics, Langmuir, Langmuir and Freundlich Isotherms, N-Hap, pH, Pore Diffusion, Potential, Pseudo Second Order, Pseudo-Second-Order, Rights, Sorbent, Sorption, Water

? Malekpour, A., Hajialigol, S. and Taher, M.A. (2009), Study on solid-phase extraction and flame atomic absorption spectrometry for the selective determination of cadmium in water and plant samples with modified clinoptilolite. Journal of Hazardous Materials,