Personal Research Database

Full Text: 2010\Sep Sci Tec45, 1066.pdf

Abstract: Pure form, single phase, and highly crystalline low-silica zeolite Y was synthesized from natural nanotubular halloysite mineral by the hydrothermal method. In the synthesis process, the halloysite consisted of SiO₂ and Al₂O₃ was used as starting material with adding supplementary silica and alumina sources. Ammonium adsorption properties of the as-synthesized zeolite Y were studied using batch experiments and the results revealed that its adsorption properties were strongly dependent on contact time, adsorbent dosage, pH, ionic strength, temperature, and initial concentration. The equilibrium data fit well with the Langmuir isotherm compared with the Freundlich isotherm. Kinetic studies showed that the adsorption followed the pseudo-second-order model. Thermodynamic parameters such as change in free energy (G₀), enthalpy (H₀), and entropy (S₀) were also determined, which indicated that the adsorption of ammonium on zeolite Y was a spontaneous and exothermic process at ambient conditions. Due to its low cost, high adsorption capacity and fast adsorption rate, the zeolite Y synthesized from halloysite has the potential to be utilized for the cost-effective removal of ammonium from wastewater.

Keywords: Acid, Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Capacity, Adsorption Properties, Adsorption Rate, Alumina, Ammonium, Aqueous-Solution, Batch, Batch Experiments, Capacity, Clinoptilolite, Concentration, Cost, Cost-Effective, Data, Energy, Enthalpy, Entropy, Equilibrium, Exothermic, Experiments, Faujasitic Zeolites, Fly-Ash, Freundlich, Freundlich Isotherm, Halloysite, Hydrothermal Method, Ion-Exchange, Ionic Strength, Isotherm, Kinetic, Kinetic Studies, Landfill Leachate, Langmuir, Langmuir Isotherm, Low Cost, Model, Natural, Natural Zeolite, pH, Potential, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Removal, Silica, Sources, Strength, Synthesis, Temperature, Thermodynamic, Thermodynamic Parameters, Tuff, Wastewater, Zeolite, Zeolite Y

? Wawrzkiewicz, M. and Hubicki, Z. (2010), Weak base anion exchanger amberlite fpa51 as effective adsorbent for acid blue 74 removal from aqueous medium: Kinetic and equilibrium studies. Separation Science and Technology, 45 (8), 1076-1083.

Full Text: 2010\Sep Sci Tec45, 1076.pdf

Abstract: In this work, the macroporous anion exchange resin - Amberlite FPA51, is proposed as the effective adsorbent for the removal of Acid Blue 74 from aqueous solutions. The sorption mechanism was investigated under static conditions taking into account the phase contact time, solution pH, initial dye concentration, and temperature. The equilibrium data were fitted to the Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. The maximum monolayer capacity Q₀ was 123.8mg/g. The adsorption kinetics was found to follow the pseudo-second order model. The sorption energy was equal to 14.5kJ/mol and indicated that the adsorption process of the dye may be described via a chemical anion-exchange mechanism.

Keywords: Acid Blue, Activated Carbon, Adsorbent, Adsorption, Adsorption Kinetics, Anion Exchange Resin, Anion Exchanger, Aqueous Solutions, Capacity, Chemical, Concentration, Data, Dye, Energy, Equilibrium, Freundlich, Indigo Carmine Dye, Isotherm, Kinetic, Kinetics, Langmuir, Macroporous, Mechanism, Metal-Ions, Methylene-Blue, Model, Models, Monolayer, pH, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second Order Model, Pseudo-Second-Order, Reactive Dyes, Removal, Resin, Rice Husk, Solution, Solutions, Sorption, Sorption Mechanism, Temperature, Textile Wastewaters, Waste-Water, Work

? Park, K.H., Shim, W.G., Shon, H.K., Lee, S.G., Ngo, H.H., Vigneswaran, S. and Moon, H. (2010), Adsorption characteristics of acetaldehyde on activated carbons prepared from corn-based biomass precursor. Separation Science and Technology, 45 (8), 1084-1091.

Full Text: 2010\Sep Sci Tec45, 1084.pdf

Abstract: The ACs (R-1/2 and R-1/4) having two different textual and chemical properties are prepared from corn-based biomass precursor and evaluated together with a wood-based activated carbon (WAC) at room temperature using a gas chromatograph. The results obtained from the correlation studies indicate that the pore size distribution (below 8 angstrom) and the relatively lower energetic heterogeneity of ACs on acetaldehyde adsorption are considerable factors rather than that of a specific surface area and surface chemistry. The adsorption equilibrium of ACs is well correlated with the Sips equation. The pseudo second-order equation was better in describing the ACs’ adsorption kinetic of acetaldehyde.

Keywords: Acetaldehyde, Activated Carbon, Adsorption, Adsorption Equilibrium, Adsorption Kinetic, Biomass, Carbon, Chemical, Chemistry, Corn Grain, Correlation, Distribution, Equilibrium, Heterogeneity, Kinetic, Kinetics, Pseudo Second Order, Pseudo Second-Order, Pseudo Second-Order Equation, Pseudo-Second-Order, Room Temperature, Second Order, Second-Order, Second-Order Equation, Size, Specific Surface, Specific Surface Area, Surface, Surface Area, Surface Chemistry, Temperature, Water Vapor

? Nassar, N.N. (2010), Kinetics, mechanistic, equilibrium, and thermodynamic studies on the adsorption of acid red dye from wastewater by-Fe₂O₃ nanoadsorbents. Separation Science and Technology, 45 (8), 1092-1103.

Full Text: 2010\Sep Sci Tec45, 1092.pdf

Abstract: The presence of dyestuffs in wastewater poses an environmental concern since these organic contaminants are toxic to aquatic and non-aquatic life. In addition, these contaminants are difficult to remove or biodegrade, which poses a challenge to the conventional wastewater treatment techniques. In this work, the adsorption of acid red dye 27 (AR27) onto -Fe₂O₃ nanoadsorbents was studied for the removal of red dye from aqueous solutions by the batch-adsorption technique. The experiments were carried out at different conditions of contact time, initial AR27 concentration, temperature, co-existing ions, and solution pH. It was found that the adsorption was a rapid process, and equilibrium was achieved in less than 4 minutes. The removal of AR27 decreased with the increase in solution pH and temperature. Furthermore, the addition of chloride and nitrate anions has no remarkable influence on AR27 removal efficiency. On the other hand, the effects of sulfate and bicarbonate anions on the removal of AR27 were significant. The adsorption equilibrium data fitted very well using Langmuir and Freundlich adsorption isotherm models. The data obtained from adsorption isotherms at different temperatures were used to calculate thermodynamic quantities of adsorption, such as standard Gibbs free energy change [image omitted], enthalpy change [image omitted], and entropy change [image omitted]. The adsorption process was found to be spontaneous, exothermic and physical in nature. The results indicate that -Fe₂O₃ nanoadsorbents could be employed for the removal of dyes from wastewater.

Keywords: Activated Carbons, Adsorption, Adsorption Equilibrium, Adsorption Isotherm, Adsorption Isotherm Models, Adsorption Isotherms, Anions, Aqueous Solutions, Aqueous-Solutions, Batch Adsorption, Bentonite, Challenge, Chloride, Concentration, Contaminants, Conventional, Cost Effective, Data, Dye, Dyes, Efficiency, Effluents, Energy, Enthalpy, Entropy, Environmental, Equilibrium, Exothermic, Experiments, Freundlich, Freundlich Adsorption Isotherm, Gibbs Free Energy, Ions, Iron Oxide, Isotherm, Isotherms, Kinetics, Langmuir, Life, Low-Cost Adsorbents, Magnetic Nanoparticles, Methylene-Blue, Models, Nanoadsorbent, Nitrate, Organic, pH, Physical, Pore, Red Dye, Removal, Removal Efficiency, Removal of Dyes, Solution, Solutions, Sorption, Standard, Sulfate, Techniques, Temperature, Thermodynamic, Toxic, Treatment, Wastewater, Wastewater Treatment, Work

? Al-Khalisy, R.S., Al-Haidary, A.M.A. and Al-Dujaili, A.H. (2010), Aqueous phase adsorption of cephalexin onto bentonite and activated carbon. Separation Science and Technology, 45 (9), 1286-1294.

Full Text: 2010\Sep Sci Tec45, 1286.pdf

Abstract: The adsorption of cephalexin in aqueous solution has been investigated using bentonite and activated carbon as the adsorbents. Batch kinetics and isotherm studies were carried out to evaluate the effect of contact time, adsorbent dosage, pH, particle size, and temperature. Adsorption equilibrium data were well represented by the Langmuir and Freundlich isotherm models. The adsorption intensity was found to be increased as the aqueous phase pH increased, and had a maximum at pH=6.1. The pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models were used to describe the kinetic data. The experimental data fitted very well with the pseudo-second-order kinetic model and also followed the simple external and intraparticle model.

Keywords: Activated Carbon, Adsorbent, Adsorbent Dosage, Adsorbents, Adsorption, Adsorption Equilibrium, Antibiotics, Aqueous Phase, Aqueous Solution, Bentonite, Biosorption, Carbon, Cephalexin, Cephalosporins, Data, Diffusion, Equilibrium, Experimental, Freundlich, Freundlich Isotherm, Intraparticle Diffusion, Isotherm, Isotherms, Kinetic, Kinetic Data, Kinetic Model, Kinetic Models, Kinetics, Langmuir, Liquid Membrane, Methylene-Blue, Model, Models, Particle Size, pH, Pseudo First Order, Pseudo Second Order, Pseudo-First Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Removal, Size, Solution, Sorbents, Temperature

? Vasudevan, S., Lakshmi, J. and Sozhan, G. (2010), Studies relating to removal of arsenate by electrochemical coagulation: Optimization, kinetics, coagulant characterization. Separation Science and Technology, 45 (9), 1313-1325.

Full Text: 2010\Sep Sci Tec45, 1313.pdf

Abstract: The present investigation aims to remove arsenate [As(V)] by electrochemical coagulation using mild steel as anode and cathode. The results showed that the optimum removal efficiency of 98.6% was achieved at a current density of 0.2Adm-2, at a pH of 7.0. The effect of current density, solution pH, temperature, co-existing ions, adsorption isotherm, and kinetics has been studied. Kinetics reveals that the removal of arsenate by electrochemical coagulation is very rapid in the first 15min and remains almost constant with the progress of reaction. The adsorption kinetics obeys the second-order rate expression. An equilibrium isotherm was measured experimentally and the results were analyzed by Langmuir, Freundlich, Dubinin- Redushkevich, and Frumkin using the linearized correlation co-efficient. The characteristics parameters for each isotherm were determined. The Langmuir adsorption isotherm was found to fit the equilibrium data for arsenate adsorption. Temperature studies showed that the adsorption was endothermic and spontaneous in nature.

Keywords: Activated Carbon, Adsorption, Adsorption Isotherm, Adsorption Kinetics, Aqueous-Solutions, Arsenate, Arsenate Removal, Arsenic(V), Basic Dye, Characteristics, Characterization, Coagulation, Correlation, Correlation Coefficient, Data, Drinking-Water, Efficiency, Electrochemical Coagulation, Electrocoagulation, Endothermic, Equilibrium, Equilibrium Isotherm, Expression, First, Freundlich, Investigation, Ions, Iron, Isotherm, Isotherms, Kinetics, Langmuir, Langmuir Adsorption Isotherm, Oxide, pH, Progress, Removal, Removal Efficiency, Second Order, Second-Order, Solution, Temperature, Waste-Water

? Kumar, P., Sudha, S., Chand, S. and Srivastava, V.C. (2010), Phosphate removal from aqueous solution using coir-pith activated carbon. Separation Science and Technology, 45 (10), 1463-1470.

Full Text: 2010\Sep Sci Tec45, 1463.pdf

Abstract: The present study deals with the removal of phosphates from aqueous solution using activated carbon developed from coir pith. Batch adsorption experiments were performed to delineate the effect of initial pH, contact time, adsorbent dose and temperature on the removal of phosphates by coir-pith activated carbon (CAC) (activated by H2SO4). The removal was found to be maximum in the pH range of 6-10. The kinetics of adsorption showed that the phosphate adsorption onto CAC was a gradual process with a quasi-equilibrium being attained in 3h. The adsorption equilibrium data followed the Temkin isotherm. Thermodynamic parameters such as Go, Ho, and So were evaluated by applying the Arrhenius and van’t Hoff equations, and it was found that the adsorption of phosphate on CAC was spontaneous and endothermic.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Kinetics, Adsorption Thermodynamics, Coir Pith Activated Carbon, Equilibrium, Fly-Ash, Goethite, Husk Ash RHA, Isotherm, Kinetics, Metal-Ions, Phosphate, Removal, Sorption, Thermodynamic, Thermodynamics

? Largura, M.C.T., Debrassi, A., dos Santos, H.H., Marques, A.T. and Rodrigues, C.A. (2010), Adsorption of rhodamine B onto O-carboxymethylchitosan-N-lauryl. Separation Science and Technology, 45 (10), 1490-1498.

Full Text: 2010\Sep Sci Tec45, 1490.pdf

Abstract: The adsorption of a cationic dye (rhodamine B, RB) on O-carboximethyl-N-acetylated (L-CMCh) in aqueous solution was investigated. The effect of the process parameters such as the contact time, pH, and temperature are reported. Both temperature and pH influence dye adsorption. To determine the adsorption capacity, the equilibrium adsorption data were analyzed by the Langmuir, Langmuir-Freundlich, and Redlich-Peterson isotherm models. The results showed better agreement with the Langmuir-Freundlich model than the other models. The maximum adsorption capacity of RB for L-CMCh was determined as 38.5mgg^-1 at pH 8.5 and 25°C. The kinetic results follow a pseudo-second-order rate equation. The activation energy value for adsorption of RB on L-CMCh was found to be 52.0 kJmol^-1. The negative values of Gibbs free energy and enthalpy show the adsorption to be spontaneous and exothermic. The negative value of the enthalpy for adsorption of RB onto L-CMCh shows the adsorption to be exothermic.

Keywords: Activation Energy, Adsorbent, Adsorption, Aqueous-Solution, Batch, Carboxymethylchitosan-N-Acetylated, Chitosan Hydrobeads, Dye, Dye Removal, Equilibrium, Equilibrium Adsorption, Isotherm, Kinetic, Kinetic Adsorption, Kinetics, Langmuir, Malachite Green, Maximum Adsorption Capacity, Reactive Dye, Rhodamine B, Waste Materials, Water

? Yang, J.S., Park, Y.T., Baek, K. and Choi, J. (2010), Removal of metal ions from aqueous solutions using sawdust modified with citric acid or tartaric acid. Separation Science and Technology, 45 (12-13), 1963-1974.

Full Text: 2010\Sep Sci Tec45, 1963.pdf

Abstract: This study describes the adsorption of heavy metal ions (Cd(II), Cu(II), Ni(II), Pb(II), and Zn(II)) from aqueous solutions by pine (Pinus densiflora) sawdust modified with citric acid (CA) or tartaric acid (TA). The optimal parameters, contact time, and pH were determined and the adsorption isotherms were obtained. The removal efficiency of the modified sawdust increased as the pH increased. The maximum adsorption capacity of sawdust modified with CA or TA was 14 to 57 times higher than that of unmodified sawdust. These results indicate that either CA or TA can be used to enhance the removal of heavy metals using sawdust.

Keywords: Activated Carbon, Adsorbents, Adsorption, Adsorption, Adsorption Capacity, Adsorption Isotherms, Aqueous Solutions, Capacity, Cd(II), Citric Acid, Cr(VI), Cu(II), Efficiency, Electroplating Waste-Water, Equilibrium, Heavy Metal, Heavy Metal Ions, Heavy Metals, Heavy-Metals, Ions, Isotherms, Metal, Metal Ions, Metals, Modified, Ni(II), Pb(II), pH, Removal, Removal Efficiency, Rice Husk, Sawdust, Solutions, Tartaric Acid, Thermodynamics, Wood Sawdust

? Sonar, N.L., Pardeshi, V., Shukla, R., Sonavane, M.S., Valsala, T.P., Kulkarni, Y., Tyagi, A.K., Kaushik, C.P. and Manchanda, V.K. (2010), Evaluation of nickel sulphide prepared by different routes for removal of 106Ru from alkaline radioactive liquid waste. Separation Science and Technology, 45 (14), 2064-2075.

Full Text: 2010\Sep Sci Tec45, 2064.pdf

Abstract: An attempt has been made to synthesize nickel sulphide (NiS) compound by different routes. The NiS material thus obtained was coated on polymethyl metha acrylate (PMMA) beads to form a composite material, which was subjected to its performance evaluation for uptake of 106Ru from low level radioactive liquid waste (LLW) stream. Distribution Coefficient (Kd) of 106Ru from LLW using NiS-PMMA composite beads was found to be in the range of 9000-12000 (ml/g). The effect of various parameters viz. pH, ionic strength, temperature, time equilibration, etc. towards the uptake of 106Ru was investigated. The sorption mechanism was also studied. The G, H, and S value for sorption were evaluated. The sorption was observed to be spontaneous and endothermic in nature. From the practical utilization point of view, the rate of uptake of 106Ru by the composite material was studied. The data of sorption was investigated with Lagergren first-order, pseudo-first-order, and second-order plots. Its intraparticle diffusion mechanism was studied with the Weber Morris model. The kinetics was found to follow a pseudo-first-order pattern with intraparticle diffusion. However, intraparticle diffusion is not the rate controlling step.

Keywords: Adsorption, Aqueous-Solution, Beads, Coated, Complexes, Composite, Data, Diffusion, Endothermic, Equilibration, Evaluation, Exchange Resin, First Order, Intraparticle Diffusion, Ionic Strength, Kinetics, Lagergren, Liquid, Low Level Radioactive Liquid Waste (LLW), Low-Level, Mechanism, Metal-Ions, Model, Nickel, Nickel Sulphide, Nitrosylruthenium, Pattern, Performance, Performance Evaluation, pH, Pmma, Polymeric Material, Polymethyl Metha Acrylate, Pseudo First Order, Pseudo-First-Order, Purex Process, Removal, Ruthenium, Ruthenium, Second Order, Second-Order, Sorption, Sorption Mechanism, Stream, Strength, Temperature, Uptake, Utilization, Value, Waste, Weber Morris

? Ozdes, D., Gundogdu, A., Duran, C. and Senturk, H.B. (2010), Evaluation of adsorption characteristics of malachite green onto almond shell (Prunus dulcis). Separation Science and Technology, 45 (14), 2076-2085.

Full Text: 2010\Sep Sci Tec45, 2076.pdf

Abstract: The potential usage of almond shell (P. dulcis), which is an agricultural waste product, in the removal of malachite green from aqueous solutions was evaluated with respect to various experimental parameters including contact time, initial malachite green concentration, temperature, adsorbent concentration, etc. The adsorption kinetics of malachite green fitted well the pseudo-second-order kinetic model. The monolayer adsorption capacity of almond shell was found to be 29.0mg g-1. The adsorption of malachite green onto almond shell increased with raising the temperature. From the experimental results, almond shell could be employed as a low cost and easily available adsorbent for removal of malachite green in wastewater treatment process.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Capacity, Adsorption Kinetics, Agricultural, Agricultural Waste, Almond, Almond Shell, Aqueous Solutions, Aqueous-Solution, Basic-Dyes, Capacity, Concentration, Cost, Equilibrium, Experimental, Industrial Waste-Water, Kinetic, Kinetic Model, Kinetics, Low Cost, Malachite Green, Mechanism, Methylene-Blue, Model, Monolayer, P, Potential, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Removal, Removal, Solutions, Sorption, Temperature, Thermodynamic, Treatment, Waste, Wastewater, Wastewater Treatment

? Wang, X.H. and Wang, A.Q. (2010), Adsorption characteristics of chitosan-g-poly(acrylic acid)/attapulgite hydrogel composite for Hg(II) ions from aqueous solution. Separation Science and Technology, 45 (14), 2086-2094.

Full Text: 2010\Sep Sci Tec45, 2086.pdf

Abstract: Batch adsorption experiments were carried out to remove Hg(II) from aqueous solutions using chitosan-g-poly(acrylic acid)/attapulgite hydrogel composites as adsorbents. The factors influencing the adsorption capacity of the composites were investigated. The results indicate that the adsorption equilibrium of the composites can be achieved within about ten minutes and the equilibrium adsorption capacities of the composites with 10, 30, and 50wt% of attapulgite content were 785.20, 679.63, and 541.06mg g^-1, respectively. The negative values of G and positive values of H indicate that the adsorption processes are all spontaneous and endothermic.

Keywords: Activated Palygorskite, Adsorbents, Adsorption, Adsorption Capacities, Adsorption Capacity, Adsorption Equilibrium, Aqueous Solutions, Attapulgite, Batch Adsorption, Biosorption, Capacity, Carbons, Chitosan, Clay, Coal, Composite, Composites, Endothermic, Equilibrium, Experiments, Heavy-Metal Ions, Hg(II), Hydrogel, Hydrogel Composite, Mercury(II) Removal, Recovery, Solutions, Thermodynamic Parameter, Waste-Water, Wastewaters

? Khalid, N. and Rahman, S. (2010), Adsorptive removal of lead from battery wastewater by coconut coir. Separation Science and Technology, 45 (14), 2104-2112.

Full Text: 2010\Sep Sci Tec45, 2104.pdf

Abstract: The sorption behavior of lead ions on coconut coir has been investigated to decontaminate lead ions from aqueous solutions. Various physico-chemical parameters were optimized to simulate the best conditions in which this material can be used as an adsorbent. Maximum adsorption was observed at 0.0001 to 0.001mol L^-1 of acid solutions (HNO₃, HCl and HClO₄) using 0.4g of adsorbent for 4.83×10^-5mol L^-1 lead concentration in ten minutes equilibration time. The adsorption of lead was decreased with the increase in the concentrations of all the acids used. The kinetic data indicated an intraparticle diffusion process with sorption being pseudo-second order. The determined rate constant k² was 8.8912g mg-1min^-1. The adsorption data obeyed the Freundlich isotherm over the lead concentration range of 2.41×10^-4 to 1.45x10-3mol L^-1. The characteristic Freundlich constants i.e., 1/n=0.44±0.02 and K=0.184±0.0096m mol g-1 have been computed for the sorption system. The sorption mean free energy from the Dubinin-Radushkevich isotherm is 10.48±0.72kJ mol^-1 indicating the ion-exchange mechanism of chemisorption. The uptake of lead increases with the rise in temperature (293-333K). Thermodynamic quantities i.e., G, S, and H have also been calculated for the system. The sorption process was found to be endothermic. The proposed procedure was successfully applied for the removal of lead from battery wastewater samples.

Keywords: Activated Carbon, Adsorbent, Adsorption, Aqueous Solutions, Aqueous-Solutions, Behavior, Cadmium, Chemisorption, Coconut Coir, Composite, Concentration, Data, Diffusion, Endothermic, Energy, Equilibration, Extraction, Freundlich, Freundlich Isotherm, Heavy-Metal Ions, Intraparticle Diffusion, Ion Exchange, Ion-Exchange, Ionexchange, Ions, Isotherm, Kinetic, Kinetics, L1, Lead, Lead Adsorption, Mass-Spectrometry, Mechanism, Preconcentration, Procedure, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second-Order, Rate Constant, Removal, Solutions, Sorption, Sorption Isotherms, Sorption Process, Temperature, Thermodynamic, Thermodynamics, Trace-Metals, Uptake, Wastewater

? Ma, J.W., Wang, H., Wang, F.Y. and Huang, Z.H. (2010), Adsorption of 2,4-dichlorophenol from aqueous solution by a new low-cost adsorbent - activated bamboo charcoal. Separation Science and Technology, 45 (16), 2329-2336.

Full Text: 2010\Sep Sci Tec45, 2329.pdf

Abstract: Adsorption experiments were conducted to study the removal of 2,4-dichlorophenol (2,4-DCP) from aqueous solution by a new low-cost adsorbent-activated bamboo charcoal. The results showed that acidic pH was favorable for the adsorption and removal of 2,4-DCP. Higher initial 2,4-DCP concentrations led to higher adsorption capacity. Most of the adsorption of 2,4-DCP occurred within the first 5min, and about 90% of 2,4-DCP were removed from solution. After 5min, the adsorption capacity increased slowly with contact time and the adsorption reached equilibrium in less than 100min. As the adsorbent dose was increased, the removal of 2,4-DCP was increased, while the equilibrium time was slightly affected. Adsorption kinetics could be best described by the pseudo-second-order model, independent of adsorbent dosages. The adsorption behavior of 2,4-DCP onto bamboo charcoal fitted both Langmuir and Freundlich isotherms well, but followed Freundlich isotherm more precisely. This study demonstrated for the first time that activated bamboo charcoal could be used for the removal of 2,4-DCP in water treatment.

Keywords: 2,4-Dcp, Adsorbent, Adsorption, Adsorption Capacity, Adsorption Kinetics, Agricultural Waste, Bamboo, Capacity, Carbon, Charcoal, Contact Time, Drinking-Water, Dye Removal, Equilibrium, Fly-Ash, Freundlich, Freundlich Isotherm, Heavy-Metal Ions, Isotherm, Isotherms, Kinetics, Langmuir, Langmuir And Freundlich Isotherms, Model, pH, Phanerochaete-Chrysosporium, Phenolic-Compounds, Pseudo Second Order, Pseudo-Second-Order, Removal, Solid-Waste, Substituted Phenols, Treatment, Water, Water Treatment

? Anirudhan, T.S., Divya, L., Bringle, C.D. and Suchithra, P.S. (2010), Removal of Copper(II) and Zinc(II) from aqueous solutions using a lignocellulosic-based polymeric adsorbent containing amidoxime chelating functional groups. Separation Science and Technology, 45 (16), 2383-2393.

Full Text: 2010\Sep Sci Tec45, 2383.pdf

Abstract: In this study, the adsorption of Cu(II) and Zn(II) ions from aqueous solutions onto amidoximated polymerized banana stem (APBS) has been investigated. Infrared spectroscopy was used to confirm graft copolymer formation and amidoxime functionalization. The different variables affecting the sorption capacity such as pH of the solution, adsorption time, initial metal ion concentration, and temperature have been investigated. The optimum pH for maximum adsorption was 10.5 (99.99%) for Zn2+ and 6.0 (99.0%) for Cu²⁺ at an initial concentration of 10mgL-1. Equilibrium was achieved approximately within 3h. The experimental kinetic data were analyzed using pseudo-first-order and pseudo-second-order kinetic models and are well fitted with pseudo- second-order kinetics. The thermodynamic activation parameters such as Go, Ho, and So were determined to predict the nature of adsorption. The temperature dependence indicates an exothermic process. The experimental isotherm data were well fitted to the Langmuir model with maximum adsorption capacities of 42.32 and 85.89mgg-1 for Cu(II) and Zn(II), respectively, at 20 degrees C. The adsorption efficiency was tested using industrial effluents. Repeated adsorption/regeneration cycles show the feasibility of the APBS for the removal of Cu(II) and Zn(II) ions from water and industrial effluents.

Keywords: Acrylonitrile, Activation, Adsorbent, Adsorption, Adsorption, Amidoxime, Aqueous Solutions, Banana Stem, Banana Stem, Batch Reactor, Capacity, Copper(II), Cu(II), Cu²⁺, Cycles, Data, Effluents, Equilibrium, Graft Copolymerization, Industrial, Industrial Effluents, Isotherm, Kinetic, Kinetic Models, Kinetics, Langmuir, Langmuir Model, Model, Models, pH, Phosphate, Process, Pseudo Second Order, Pseudo-Second-Order, Removal, Second-Order, Sorption, Sorption Capacity, Temperature, Temperature Dependence, Thermodynamic, Wastewaters, Water, Zinc(II), Zn(II), Zn²⁺

? Jana, S., Purkait, M.K. and Mohanty, K. (2011), Preparation and characterizations of ceramic microfiltration membrane: Effect of inorganic precursors on membrane morphology. Separation Science and Technology, 46 (1), 33-45.

Full Text: 2011\Sep Sci Tec46, 33.pdf

Abstract: Ceramic disc type microfiltration membranes (50mm diameter and 5mm thickness) were prepared by the paste method from different compositions of clay, kaolin, and binding agents like sodium carbonate, sodium metasilicate, boric acid, and sintered at different temperatures. All the membranes were characterized by TGA, SEM, XRD, water permeability test, and acid-base treatment. With the increase of sintering temperature, the pore size as well as the permeability and flexural strength were increasing while porosity and pore density were decreasing. It was found that with increasing the amount of kaolin and decreasing the amount of clay the pore diameter was decreasing. A membrane prepared from 18% clay, 62% kaolin, and 20% binding material and sintered at 1000 degrees C has shown the lowest average pore size of 0.31m with porosity, pore density, and flexural strength of 0.22, 4.80x1012m-2 and 12.81MPa respectively. The membrane pore size and pore density were predicted directly from the particle size distribution of the clay and kaolin and were suitably represented by second-order polynomials.

Keywords: Alumina, Binding, Carbonate, Ceramic, Ceramic Membrane, Clay, Distribution, Elaboration, Filtration, Kaolin, Membrane, Microfiltration, Particle Size, Particle Size Distribution, Permeability, Pore Size Prediction, Porosity, Preparation, Second Order, Second-Order, SEM, Sintering, Size, Sodium, Strength, Supports, Temperature, TGA, Treatment, Ultrafiltration Membranes, Water, XRD

? Ma, H.M., Zhu, Z.L., Dong, L.J., Qiu, Y.L. and Zhao, J.F. (2011), Removal of arsenate from aqueous solution by manganese and iron (hydr)oxides coated resin. Separation Science and Technology, 46 (1), 130-136.

Full Text: 2011\Sep Sci Tec46, 130.pdf

Abstract: A composite adsorbent MIR, manganese and iron (hydr)oxides coated resin, was prepared by coating manganese and iron (hydr)oxides onto the weak basic anion exchange resin D301. The effects of solution pH, contact time, ionic strength, and coexisting ions on arsenate removal with MIR were investigated in batch experiments. The results showed that As(V) can be effectively removed in a wide pH range of 49. The presence of coexisting anions such as [image omitted] had no noticeable effect on arsenate removal efficiency. However, [image omitted] were found to interfere with the arsenate removal significantly. Arsenate adsorption efficiency decreased with the increment of ion strength of the solution. The adsorption isotherm could be well described by the Freundlich model. A pseudo second-order kinetics was able to provide a realistic description of the adsorption kinetics.

Keywords: Adsorbent, Adsorption, Adsorption Isotherm, Adsorption Kinetics, Aluminum, Anion Exchange Resin, Anions, Arsenate, Arsenate Removal, Arsenic, Arsenic(V) Removal, As(V), Batch, Batch Experiments, Coated, Coating, Composite, Dissolved Carbonate, Efficiency, Experiments, Ferrihydrite, Freundlich, Freundlich Model, Groundwater, Ion Strength, Ionic Strength, Ions, Iron, Iron (Hydr)Oxides, Isotherm, Kinetics, Manganese, Manganese (Hydr)Oxides, Model, Ph, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo Second-Order, Pseudo-Second-Order, Removal, Removal Efficiency, Resin, Second Order, Second Order Kinetics, Second-Order, Second-Order Kinetics, Solution, Sorption, Strength, Surface Speciation, Water Interface

? Vijayalakshmi, P., Bala, V.S.S., Thiruvengadaravi, K.V., Panneerselvam, P., Palanichamy, M. and Sivanesan, S. (2011), Removal of Acid Violet 17 from aqueous solutions by adsorption onto activated carbon prepared from pistachio nut shell. Separation Science and Technology, 46 (1), 155-163.

Full Text: 2011\Sep Sci Tec46, 155.pdf

Abstract: Adsorbents prepared from pistachio nut shell, an agricultural waste biomass, were successfully used to remove Acid Violet 17 from an aqueous solution. The activated carbons PNS1, PNS2, and PNS3 were characterized by scanning electron microscope (SEM), Fourier Transform - Infra Red spectroscopy (FTIR) and (BET). The effect of pH, adsorbent dosage, and temperature on dye removal was studied. Maximum color removal was observed at pH 2. The adsorption increased with the increase in adsorbent dosage. As the adsorption capacity increased with the increase in temperature, the process was concluded to be endothermic. The experimental data were analyzed by the Langmuir and Freundlich isotherm models of adsorption. Equilibrium data fitted well with the Langmuir model. The rates of adsorption confirmed the pseudo-second order kinetics with good correlation values. The results indicated that the activated carbon prepared from pistachio nut shell can be effectively used for the removal of Acid Violet 17 from aqueous solution.

Keywords: Acid Violet 17, Activated Carbon, Activated Carbons, Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Capacity, Agricultural, Agricultural Waste, Aqueous Solution, Bet, Biomass, Capacity, Carbon, Color Removal, Correlation, Data, Dye, Dye Removal, Effluent, Endothermic, Equilibrium, Experimental, Freundlich, Freundlich Isotherm, Ftir, Isotherm, Isotherms, Kinetics, Kinetics, Langmuir, Langmuir Model, Model, Models, pH, Pistachio Nut Shell, Pith, Products, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second Order, Pseudo-Second Order Kinetics, Pseudo-Second-Order, Rates, Removal, SEM, Solution, Sorption, Spectroscopy, Temperature, Waste, Waste Biomass, Waters

? Chauhan, K. and Chauhan, G.S. (2011), Separation of uranyl ions on starch-based functional hydrogels: Mechanism and kinetics. Separation Science and Technology, 46 (1), 172-178.

Full Text: 2011\Sep Sci Tec46, 172.pdf

Abstract: In this article, we report the mechanism and kinetics of adsorption of uranyl ions on starch-based functional hydrogels. The hydrogels were prepared from starch in native or hydrolyzed/oxidized form by crosslinking with N,N-methylenebisacrylamide. The hydrogels synthesized from the oxidized starch have carboxylic groups at C-6 position. The effect of the structure and external environmental factors, i.e., contact time, temperature, ion strength, and simulated seawater (0.55M NaCl and 3mM NaHCO₃), was investigated on the uranyl adsorption behavior of hydrogels. The adsorption of uranyl ions was rapid as the highest adsorption was observed after 6h and at 40ºC. The sorbents also exhibited appreciable ion uptake even from the simulated seawater. The equilibrium data was analyzed using Langmuir and Freundlich adsorption isotherms and pseudo-first order and pseudo-second order kinetic models. Evidence of adsorption was obtained by characterization of the uranyl ions-loaded hydrogels by FTIR spectroscopy and also by elution with 0.1N HCl.

Keywords: Acid Hydrogels, Acrylamide, Adsorption, Adsorption Behavior, Adsorption Isotherms, Aqueous-Solutions, Behavior, Carboxylic, Cellulose, Characterization, Crosslinking, Data, Elution, Environmental, Equilibrium, Freundlich, FTIR, FTIR Spectroscopy, Functional Starch, Graft-Copolymers, Heavy-Metals, Hydrogels, Ion Strength, Ions, Isotherms, Kinetic, Kinetic Models, Kinetics, Kinetics of Adsorption, Langmuir, Mechanism, Models, NaCl, Pseudo First Order, Pseudo Second Order, Pseudo-First Order, Pseudo-First Order and Pseudo-Second Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second-Order, Recovery, Removal, Seawater, Separation, Simulated Seawater, Sorbents, Spectroscopy, Starch, Strength, Structure, Temperature, Uptake, Uranium, Uranyl Ions

? Liu, Y., Li, H., Tan, G.Q. and Zhu, X.H. (2011), Fe²⁺-modified vermiculite for the removal of chromium(VI) from aqueous solution. Separation Science and Technology, 46 (2), 290-299.

Full Text: 2011\Sep Sci Tec46, 290.pdf

Abstract: A novel adsorbent: Fe²⁺-modified vermiculite was prepared in a two-step reaction. Adsorption experiments were carried out as a function of pH, contact time, and concentration of Cr(VI). It was found that Fe²⁺-modified vermiculite was particularly effective for the removal of Cr(VI) at pH 1.0. The adsorption of Cr(VI) reached equilibrium within 60min, and the pseudo-second-order kinetic model best described the adsorption kinetics. The adsorption data follow the Langmuir model more than the Freundlich model. At pH 1.0, the maximum Cr(VI) sorption capacity (Qmax) was 87.72mg center dot g-1. Desorption of Cr(VI) from Fe²⁺-modified vermiculite using NaOH treatment exhibited a higher desorption efficiency by more than 80%. The sorption mechanisms including electrostatic interaction and reduction were involved in the Cr (VI) removal. The results showed that Fe²⁺-modified vermiculite can be used as a new adsorbent for Cr(VI) removal which has a higher adsorption capacity and a faster adsorption rate.

Keywords: Adsorbent, Adsorption, Adsorption, Adsorption Capacity, Adsorption Kinetics, Adsorption Rate, Biosorption, Capacity, Chromium, Concentration, Cr(VI) Anion, Cr(VI), Cr(VI) Sorption, Data, Desorption, Efficiency, Equilibrium, Experiments, Fe²⁺-Modified Vermiculite, Freundlich, Freundlich Model, Function, Interaction, Ions, Iron, Kinetic, Kinetic Model, Kinetics, Langmuir, Langmuir Model, Mechanism, Mechanism, Mechanisms, Model, NaOH, NaOH Treatment, pH, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Reduction, Removal, Sorption, Sorption Capacity, Sorption Mechanisms, Treatment, Vermiculite, Waste

? Abu Al-Rub, F.A., Hamdi, J., Hamdi, N., Allaboun, H., Al Zarooni, M. and Al-Sharyani, M. (2011), Adsorption of phenol on different activated carbons prepared from date pits. Separation Science and Technology, 46 (2), 300-308.

Full Text: 2011\Sep Sci Tec46, 300.pdf

Abstract: The potential use of different activated carbons (ACs) prepared from dates pits and phosphoric acid for the removal of phenol from aqueous solutions was investigated. Date pits were converted into five different types of activated carbons by air and phosphoric acid activation. The specific surface area (BET) of the prepared ACs varied from 794 m²/g, for the phosphoric acid: date pit ratio of 5:1, to 1707 m2/g for a ratio of 2:1. Batch adsorption experiments revealed that the adsorption of phenol varied among all of the prepared ACs, where the 2:1 AC showed the highest uptake. Equilibrium pH studies showed that the phenol removal was pH dependent and the maximum phenol uptake occurred at an equilibrium pH of 3.0. Dynamics studies indicated that the initial uptake of phenol on 2:1 AC at pH 4 was rapid, where 80% of the maximum uptake was achieved during the first 30 minutes, both surface adsorption and intraparticle diffusion were involved in the adsorption process and the data followed the pseudo second-order reaction. The equilibrium adsorption data of phenol on 2:1 AC at solution pH 3 was best described by the Redlich-Peterson, Sips, and Langmuir models.

Keywords: Acid Activation, Acid-Activation, Activated Carbon, Activated Carbons, Activation, Adsorption, Air, Aqueous Solutions, Aqueous-Solutions, Batch Adsorption, BET, Data, Diffusion, Equilibrium, Experiments, Extraction, First, Intraparticle Diffusion, Isotherm, Isotherm, Kinetics, Langmuir, Models, pH, pH-Dependent, Phenol, Phenol Removal, Phosphoric Acid, Porosity, Potential, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Reactor, Redlich-Peterson, Removal, Second Order, Second-Order, Sips, Solution, Solutions, Sorption, Specific Surface, Specific Surface Area, Surface, Surface Area, Uptake, Water

? Homagai, P.L., Ghimire, K.N. and Inoue, K. (2011), Preparation and characterization of charred xanthated sugarcane bagasse for the separation of heavy metals from aqueous solutions. Separation Science and Technology, 46 (2), 330-339.

Full Text: 2011\Sep Sci Tec46, 330.pdf

Abstract: Introduction of xanthate group onto sugarcane (Saccharum officinarum) bagasse has been investigated for the removal of cadmium, lead, nickel, zinc, and copper from their aqueous media. The charred xanthated sugarcane bagasse (CXSB) was found to have significant adsorption capacity which is more than that of various bio-sorbents mentioned in the available literatures. The newly developed bio-sorbent was characterized by SEM, FTIR, TGA/DTA, and elemental analysis. The velocity of sorption of the tested metals was fast, reaching equilibrium within 40min. The maximum loading capacities was found to be 225 for Cd(II), 318 for Pb(II), 144 for Ni(II), 164 for Zn(II), and 178 for Cu(II) mg g^-1, respectively. The fast kinetics results and high adsorption capacity indicated that CXSB can be applied as the selective adsorbent for the treatment of heavy metal ions from aqueous solutions.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption, Adsorption Capacity, Analysis, Aqueous Solutions, Bagasse, Biosorbent, Biosorbents, Biosorption, Cadmium, Capacity, Cd(II), Cd²⁺, Characterization, Charred Sugarcane Bagasse, Copper, Cu(II), Equilibrium, FTIR, Heavy Metal, Heavy Metal Ions, Heavy Metals, Ions, Isotherm, Kinetics, Lead, Loading, Media, Metal, Metal Ions, Metals, Ni(II), Nickel, Pb(II), Preparation, Removal, SEM, Separation, Solutions, Sorption, Succinic Anhydride, Sugarcane, Treatment, Waste-Water, Wastewaters, Xanthation, Zinc, Zn(II)

? Yu, J.X., Chi, R.A., He, Z.Y. and Qi, Y.F. (2011), Adsorption performances of cationic dyes from aqueous solution on pyromellitic dianhydride modified sugarcane bagasse. Separation Science and Technology, 46 (3), 452-459.

Full Text: 2011\Sep Sci Tec46, 452.pdf

Abstract: In this study, pyromellitic dianhydride (PMDA) modified waste sugarcane bagasse (SCB) was prepared through a simple method to remove two cationic dyes: methylene blue (MB) and malachite green (MG) from aqueous solution. Adsorption performances of MB and MG on the modified sorbent were investigated in details. The adsorption capacities of the modified SCB for MB and MG were 571.4 and 377.4mgg-1, respectively, which were 10 and 12 times than that obtained on the unmodified SCB. Adsorption kinetics study showed equilibriums were obtained after adsorption for 13 hours for both dyes. The modified SCB could be used repeatedly after regeneration. FTIR results showed that carboxyl and hydroxyl groups on the modified SCB involved in adsorption process.

Keywords: Activated Carbon, Adsorption, Adsorption Kinetics, Basic Dye, Dyes, Equilibrium Isotherm Analyses, Fly-Ash, Ftir, Kinetics, Malachite Green, Malachite Green Removal, Methylene Blue, Methylene-Blue, Modified, Modified Biomass, Oil Palm Shell, Pyromellitic Dianhydride, Regeneration, Sawdust Adsorption, Sorption, Sugarcane, Sugarcane Bagasse, Waste-Water

? Kurniawan, T.A., Lo, W.H. and Sillanpää, M.E.T. (2011), Treatment of contaminated water laden with 4-chlorophenol using coconut shell waste-based activated carbon modified with chemical agents. Separation Science and Technology, 46 (3), 460-472.

Full Text: 2011\Sep Sci Tec46, 460.pdf

Abstract: This laboratory study investigates the performances of coconut shell waste-based activated carbon (CSBAC) in removing 4-chlorophenol (4-CP) from contaminated water. To improve its removal for target compound, the surface of CSBAC was modified with TiO2, NaOH, and/or HNO3. Under optimized conditions at the same initial concentration of 25mg/L, the NaOH-treated CSBAC could remove 91% of 4-CP, compared to the HNO3-oxidized CSBAC (60%) or the TiO2-coated CSBAC (72%). Although the NaOH-treated CSBAC could remove 91% of 4-CP, the adsorption treatment using this adsorbent alone was unable to meet the effluent limit of lower than 1mg/L. Therefore, subsequent biological processes are required to complement the removal of 4-CP from wastewater.

Keywords: 4-Chlorophenol, Activated Carbon, Adsorbent, Adsorption, Advanced Oxidation Processes, Agricultural Waste, Aqueous-Solutions, Biological, Carbon, Coconut Shell, Concentration, Ethylenediaminetetraacetic Acid, GAC Adsorption Treatment, Heavy-Metals, Hydrogen-Peroxide, Landfill Leachate, Light-Emitting-Diodes, Low-Cost Adsorbents, Modified, NaOH, Physico-Chemical Treatments, Recalcitrant Compounds, Removal, Salicylic-Acid, Surface, Surface Modification, TiO₂, Treatment, Wastewater, Water, Water Pollution Control

? Wang, X.S. and Zhang, W. (2011), Removal of basic dye crystal violet from aqueous solution by Cu(II)-loaded montmorillonite. Separation Science and Technology, 46 (4), 656-663.

Full Text: 2011\Sep Sci Tec46, 656.pdf

Abstract: The effects of contact time, reaction temperature, and ionic strength on crystal violet adsorption onto Cu(II)-loaded montmorillonite were studied. The kinetic experimental data were analyzed using pseudo-first-order, pseudo-second-order, and Elovich equations to examine the adsorption mechanism. The result suggested that the adsorption was best represented by the pseudo-second-order equation. The suitability of the Langmuir, Freundich, and Temkin isotherms to equilibrium data was also investigated at 25ºC. The maximum adsorption capacity was 114.3mg dye/g Cu(II)-loaded montmorillonite at adsorbent concentration 1g/L. The differential heat of adsorption was evaluated and the result showed that adsorption of crystal violet onto the Cu-loaded sample was chemical in nature. The ionic strength and reaction temperature exhibited an insignificant impact on the crystal violet adsorption. The Cu(II)-loaded montmorillonite could serve as low-cost adsorbents for removing crystal violet from aqueous solution compared to the data reported in the literature.

Keywords: Adsorption, Bentonite, Biosorbents, Chitosan, Crystal Violet, Cu(II)-Loaded Montmorillonite, Dye, Equilibrium, Isotherms, Kinetic, Kinetics, Kinetics, Langmuir, Mechanism, Metal-Ions, Models, Montmorillonite, Removal, Sorption, Wastewater Treatment

? Singh, V. and Kumary, P. (2011), Design of nanostructured tamarind seed kernel polysaccharide-silica hybrids for mercury(II) removal. Separation Science and Technology, 46 (5), 825-838.

Full Text: 2011\Sep Sci Tec46, 825.pdf

Abstract: Tamarind (Tamarindus indica L.) seed kernel polysaccharide-silica (TKP-Si) nanohybrids have been fabricated in a base catalyzed sol-gel reaction where tetraethylorthosilicate (TEOS) and tamarind kernel polysaccharide were used as silica precursor and template respectively. The nanohybrids were found to be photoluminescent and efficient in Hg(II) removal from the synthetic aqueous solution. The synthesized nanohybrids were characterized using Fourier Transform Infra-red spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA), and Photoluminescence (PL) analysis. For obtaining the most efficient sample in terms of mercury (II) binding, various ratios of reactants (Polysaccharide: TEOS: H₂O: EtOH) were used and the optimum sample thus obtained was calcined at 200ºC (in air) to further enhance its binding performance. A mechanism for the sorption of Hg(II) by the optimum hybrid sample (TH1) has been proposed and to understand its sorption behavior, kinetics and isotherm studies have also been performed. Regeneration studies indicated that the loaded Hg(II) from the used hybrid can be easily desorbed and can be successfully reused for eight consecutive adsorption-desorption cycles.

Keywords: Activated Carbon, Adsorption, Aqueous Solution, Aqueous-Solutions, FTIR, Hg(II) Adsoption, Isotherm, Kinetics, Mechanism, Mercury, Modified Guar Gum, Nanocomposites, Nanohybrid, Photoluminescence, Regeneration, Removal, Sol-Gel, Sol-Gel Method, Sorbent, Sorption, Tamarind Polysaccharide, TEOS, Waste-Water

? Liu, Y., Wang, W.B., Jin, Y.L. and Wang, A.Q. (2011), Adsorption behavior of methylene blue from aqueous solution by the hydrogel composites based on attapulgite. Separation Science and Technology, 46 (5), 858-868.

Full Text: 2011\Sep Sci Tec46, 858.pdf

Abstract: A series of carboxymethyl cellulose-g-poly (acrylic acid)/attapulgite hydrogel composites were synthesized for the removal of cationic dye methylene blue. Various factors affecting the uptake behavior were investigated. Adsorption rate of the hydrogel was quite fast, and adsorption equilibrium could be reached within 30min. Adsorption kinetics well followed the pseudo-second-order equation for all systems. The Langmuir isotherm was found to best represent the data for the dye uptake. Even when 20wt% attapulgite was introduced into the hydrogel, the corresponding maximum adsorption capacity reached 1979.48 mg/g at 30ºC. The as-prepared adsorbents exhibited excellent affinity for the dye, and can be applied to treat wastewater containing basic dyes.

Keywords: Adsorption, Adsorption Kinetics, Attapulgite, Basic-Dyes, Carboxymethyl Cellulose, Cellulose, Chitosan, Clay Nanocomposite, Composite, Composites, Diffusion, Dye, Dyes, Equilibrium, Fly-Ash, Hydrogel, Isotherm, Kinetics, Langmuir, Langmuir Isotherm, Methylene Blue, Removal, Sorption, Wastewater

? Kumar, B.N., Seshadri, N., Ramana, D.K.V., Seshaiah, K. and Reddy, A.V.R. (2011), Equilibrium, thermodynamic, and kinetic studies on Trichoderma viride biomass as biosorbent for the removal of Cu(II) from water. Separation Science and Technology, 46 (6), 997-1004.

Full Text: 2011\Sep Sci Tec46, 997.pdf

Abstract: Equilibrium, thermodynamic, and kinetic studies on the biosorption of Cu(II) using biomass, Trichoderma viride were carried out. The biosorbent was characterized by Fourier transform infrared spectroscopy and Scanning Electron Microscopy. The Langmuir and Freundlich isotherm models were applied to describe the biosorption process. The influence of pH, the biomass dosage, the contact time, the initial metal ion concentration, and the temperature of the solution on the biosorption was studied. The maximum Cu(II) biosorption was attained at pH 5. The equilibrium data were better fit by the Langmuir isotherm model than by the Freundlich isotherm. The maximum biosorption capacity of T. viride biomass was found to be 19.6mg/g for Cu(II). The kinetic studies indicated that the biosorption of Cu(II) followed the pseudo-second-order model. The calculated thermodynamic parameters, Gibbs-free energy (G^o), enthalpy (H^o), and entropy (S^o) showed that the biosorption of Cu(II) onto T. viride biomass was spontaneous and endothermic. It can be concluded that the T. viride biomass has the potential as an effective and low-cost biosorbent for Cu(II) removal from aqueous solutions.

Keywords: Adsorption, Aqueous-Solution, Aspergillus-niger, Biosorbent, Biosorption, Biosorption, Cadmium, Copper, Copper, Cu(II), Equilibrium, Freundlich, Freundlich Isotherm, Green Coconut Shell, Heavy-Metals, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Isotherm, Pb(II), pH, Removal, Rhizopus-Arrhizus, Thermodynamic, Thermodynamic Parameters, Trichoderma Viride

? Bektas, N., Aydin, S. and Oncel, M.S. (2011), The adsorption of arsenic ions using beidellite, zeolite, and sepiolite clays: A study of kinetic, equilibrium and thermodynamics. Separation Science and Technology, 46 (6), 1005-1016.

Full Text: 2011\Sep Sci Tec46, 1005.pdf

Abstract: Arsenic contamination in drinking water resources is a global problem, therefore, its removal from drinking water has become an important sustainable matter. The adsorption process can be more cost-effective and applicable, especially, if the absorbents used in the process are low-cost natural geo-materials. Beidellite, zeolite, and sepiolite are inexpensive and natural minerals available locally, modified, and used as adsorbents for the removal of arsenic ions from aqueous solutions in batch experiments. The kinetics of the adsorption process was separately tested for the pseudo-first order and pseudo-second order reactions and intra-particle diffusion models. The rate constants of adsorption for all these kinetic models were calculated. The comparison among the models showed that the pseudo second-order model best described the adsorption kinetics. Applied to the experimental equilibrium, at different temperatures were the Langmuir and Freundlich isotherm models. The Langmuir isotherm was used to calculate the adsorption capacities (Qº) of minerals for arsenic ions. The adsorption capacities of these three modified minerals, at different temperatures, ranged from 476 to 841 mu g/g. Thermodynamic studies showed that the arsenic uptake reactions by minerals were endothermic and spontaneous in nature. Bottled spring water containing arsenic, sold in markets, was used to conduct the arsenic adsorption study beidellite, zeolite, and sepiolite, minerals which efficiently removed the arsenate ions from the bottled drinking water. The use of modified beidellite, zeolite, and sepiolite as adsorbents in the arsenic ion removal processes is possible, based on the optimum parameters found.

Keywords: Adsorbent, Adsorption, Adsorption Kinetics, and Isotherms, Aqueous-Solutions, Arsenic, Beidellite, Clays, Clinoptilolite, Equation, Equilibrium, Freundlich, Freundlich Isotherm, Isotherm, Kinetic, Kinetic Models, Kinetics, Langmuir, Langmuir Isotherm, Laterite, Lead, Removal, Sepiolite, Sorption, Sulfate, Thermodynamic, Thermodynamics, Water, Zeolite

? Goswami, R., Deb, P., Thakur, R., Sarma, K.P. and Basumallick, A. (2011), Removal of As(III) from aqueous solution using functionalized ultrafine iron oxide nanoparticles. Separation Science and Technology, 46 (6), 1017-1022.

Full Text: 2011\Sep Sci Tec46, 1017.pdf

Abstract: Arsenic toxicity has become a major concern worldwide. Remediation of this problem needs the development of technology with improved materials and systems with high efficiency. We have demonstrated a simple and efficient method for the absolute removal of As(III) from high concentration As(III) treated water with a low contact time period. The process of As(III) adsorption follows pseudo-second-order kinetic model. The mechanism for high-adsorption efficiency is attributed to fatty acid binding domain-mediated surface conjugation of ultrafine Fe₂O₃ nanoparticles with As(III). We have also ensured the simultaneous separation of arsenic sorbed nanoparticles by entrapping them in hydrophilic calcium alginate beads and thereby a pure arsenic free solution has been obtained.

Keywords: Adsorption, Alginate, Arsenic, Arsenic Removal, As(III), As(V), Entrapment, Groundwater, Kinetic, Kinetic Model, Maghemite, Mechanism, Remediation, Removal, Separation, Toxicity

? Bulgariu, L., Bulgariu, D. and Macoveanu, M. (2011), Adsorptive performances of alkaline treated peat for heavy metal removal. Separation Science and Technology, 46 (6), 1023-1033.

Full Text: 2011\Sep Sci Tec46, 1023.pdf

Abstract: The adsorptive performances of alkaline treated peat have been investigated for the removal of Pb(II), Co(II), and Ni(II) ions from aqueous solutions. The influence of initial metal ions concentration and equilibrium contact time was studied in a series of batch experiments, in comparison with natural peat. An increasing of adsorption capacity of alkaline treated peat was obtained for all studied heavy metals (23.07% - Pb(II), 23.53% - Co(II), and 26.19% - Ni(II)). The Langmuir isotherm model was the best model for the mathematical description of studied heavy metals adsorption on alkaline treated peat. A significant decrease of equilibrium contact time in case of alkaline treated peat was also found. The kinetics of Pb(II), Co(II), and Ni(II) uptake by alkaline treated peat followed the pseudo-second order mechanism. The FT-IR spectrometry analysis showed that carboxylic (-COO-) and hydroxyl (-OH) groups play an important role in the heavy metals binding process. The heavy metal could by easily eluted from the loaded adsorbent with 0.1mol/L HCl and the adsorbent may be reused in several adsorption/desorption cycles. The alkaline treated peat has better adsorption characteristics for the removal of heavy metals from aqueous solutions, and the cost of this treatment is very low.

Keywords: Adsorption, Alkaline Treated Peat, Aqueous-Solutions, Biosorbents, Co(II), Copper, Equilibrium, Equilibrium Isotherm, FT-IR, FTIR, Heavy Metals, Ions, Isotherm, Kinetics, Langmuir, Langmuir Isotherm, Low-Cost Adsorbents, Mechanism, Ni(II), Ni(II) Ions, Pb(II), Removal, Sorbents, Sorption, Sphagnum Moss Peat, Wastewaters

? Khan, M.A., Lee, S.H., Kang, S., Paeng, K.J., Lee, G., Oh, S.E. and Jeon, B.H. (2011), Adsorption studies for the removal of methyl tert-butyl ether on various commercially available GACs from an aqueous medium. Separation Science and Technology, 46 (7), 1121-1130.

Full Text: 2011\Sep Sci Tec46, 1121.pdf

Abstract: This study highlights the potential of four commercially available granular-activated carbons (GACs) to remove Methyl tert-butyl ether (MTBE) from an aqueous medium. Thermodynamics and kinetics parameters were elucidated. The FT-IR spectra showed decrease in peak intensity after the adsorption. The decline in the peak intensity revealed that the adsorption occurred on available active sites over the surface of the GACs. The adsorption on GACs was maximum in the pH range 7-8, with maximum adsorption capacity (47.82mg/g, pH 8) observed with CGAC. The contact time studies showed optimum adsorption of MTBE on CGAC (67.05mg/g) at 300mg/L initial MTBE concentration. The applicability of the Freundlich model illustrates a multilayer adsorption process. The adsorption process is endothermic in nature. The kinetics studies showed that the adsorption follows the pseudo-second-order model on GACs and the intraparticle diffusion is the rate-controlling mechanism on CGAC.

Keywords: Activated Carbons, Adsorption, Basic Dye, Biodegradation, Degradation, Drinking-Water, Freundlich, FT-IR, FTIR, Granular Activated Carbons, Ions, Kinetics, Kinetics, Mechanism, Methyl Tert-Butyl Ether, MTBE, pH, Physisorption, Removal, Sorption, Thermodynamics, Thermodynamics

? Martínez-Miranda, V., García-Sánchez, J.J. and Solache-Ríos, M. (2011), Fluoride ions behavior in the presence of corrosion products of iron: Effects of other anions. Separation Science and Technology, 46 (9), 1443-1449.

Full Text: 2011\Sep Sci Tec46, 1443.pdf

Abstract: The behavior of fluoride ions in the presence of corrosion products of iron in drinking and water solutions was analyzed and the adsorption capacities of the iron oxides (corrosion products of iron) for fluoride ions were determined. Drinking water containing naturally 2.45mg of fluoride ions per liter was characterized and the concentrations of other anions were determined. The effect of contact time, the initial concentration of fluoride ions, and the effect of other anions naturally present in the drinking water were considered. The kinetic results could be adjusted to the pseudo-second order model, which indicated that the sorption mechanism was chemisorption and the equilibrium was reached in 24 hours. The presence of bicarbonate and chloride ions diminishes the removal efficiency of the fluoride ions, whereas other anions (sulfate, phosphate, and nitrate) did not show any significant effect. The results reflect that the iron oxides products from the corrosion of a hydraulic infrastructure allow the removal of fluoride ions from water.

Keywords: Adsorption, Aqueous-Solutions, Corrosion, Drinking Water, Drinking-Water, Fluoride, Hydrotalcite-Like Compounds, Ions, Iron, Kinetics, Magnesium, Model, Pseudo-Second Order, Pseudo-Second-Order, Removal, Sorption, Sorption, Systems, Waste

? Suteu, D., Bilba, D., Doroftei, F. and Malutan, T. (2011), Sorption of Brilliant Red HE-3B reactive dye from aqueous solution onto seashells waste: equilibrium and kinetic studies. Separation Science and Technology, 46 (9), 1462-1471.

Full Text: 2011\Sep Sci Tec46, 1462.pdf

Abstract: The potential of waste seashells powder, as a new adsorbent for Brilliant Red HE-3B reactive dye removal from aqueous solutions, was examined by the batch technique. The Freundlich, Langmuir, and Dubinin-Radushkevich adsorption models were applied to describe the equilibrium sorption data and to determine the corresponding isotherm constants. The values of the thermodynamic parameters, G, H, and S, indicate that the sorption of reactive dye is a spontaneous and endothermic process. The kinetic data evaluated by pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models suggested that the sorption of reactive dye onto seashell is a complex process and both surface sorption and intraparticle diffusion contributes to the rate limiting step.

Keywords: Adsorbent, Adsorption, Arsenate, Brilliant Red He-3b Dye, Calcite, Decolorization, Diffusion, Equilibrium, Equilibrium And Kinetic Studies, Isotherm, Kinetic, Pseudo-First Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second-Order, Reactive Dye, Removal, Seashells Waste Powder, Shells, Sorption, Thermodynamic Parameters

? Zahoor, M. and Mahramanlioglu, M. (2011), Removal of phenolic substances from water by adsorption and adsorption-ultrafiltration. Separation Science and Technology, 46 (9), 1482-1494.

Full Text: 2011\Sep Sci Tec46, 1482.pdf

Abstract: In this work a magnetic adsorbent, magnetic activated carbon (MAC) was prepared and characterized by powdered X-Ray diffraction (XRD). A comparison was made between powdered activated carbon (PAC) and MAC for foul control in ultrafiltration (UF) membrane processes. First, the adsorptive parameters for PAC and MAC were determined for phenol, chlorophenol, nitrophenol, and hydroquinone. Equilibrium data fitted well to the Langmuir model in the studied concentration range of the adsorbates. Adsorption kinetics followed a pseudo second-order kinetic model rather than pseudo first-order kinetic model. These adsorbents were then used in combination with UF membrane. The parameters like percent rejection and flow rate for the hybrid UF, PAC and UF, MAC were determined. The influences of both adsorbents on flow rates and percent rejections were almost equal. The problems associated with PAC in the UF processes like cake formation and blackening of the pipes were not observed for MAC. MAC was removed from the slurry after use through a magnetic process.

Keywords: Activated Carbon, Activated Carbon, Adsorption, Adsorption Kinetics, Aqueous-Solution, Equilibrium, Humic Substances, Isotherms, Kinetics, Magnetic Activated Carbon, Membrane Filtration Process, Model, Model Application, Molecular-Weight, Natural Organic-Matter, PAC-UF Systems, Performance, Pretreatment, Pseudo-First-Order, Pseudo-Second-Order, Ultrafiltration