Personal Research Database

Full Text: 2005\J Haz Mat127, 89.pdf

Abstract: The removal performance and the selectivity sequence of mixed metal ions (Co²⁺, Cr³⁺, Cu²⁺, Zn²⁺ and Ni²⁺) in aqueous solution were investigated by adsorption process on pure and chamfered-edge zeolite 4A prepared from coal fly ash (CFA), commercial grade zeolite 4A and the residual products recycled from CFA. The pure zeolite 4A (prepared from CFA) was synthesized under a novel temperature step-change method with reduced synthesis time. Batch method was employed to study the influential parameters such as initial metal ions concentration, adsorbent dose, contact time and initial pH of the solution on the adsorption process. The experimental data were well fitted by the pseudo-second-order kinetics model (for Co²⁺, Cr³⁺, Cu²⁺ and Zn²⁺ ions) and the pseudo-first-order kinetics model (for Ni²⁺ ions). The equilibrium data were well fitted by the Langmuir model and showed the affinity order: Cu²⁺ > Cr³⁺ > Zn²⁺ > Co²⁺ > Ni²⁺ (CFA prepared and commercial grade zeolite 4A). The adsorption process was found to be pH and concentration dependent. The sorption rate and sorption capacity of metal ions could be significantly improved by increasing pH value. The removal mechanism of metal ions was by adsorption and ion exchange processes. Compared to commercial grade zeolite 4A, the CFA prepared adsorbents could be alternative materials for the treatment of wastewater.

Keywords: Adsorbent, Adsorbent Dose, Adsorbents, Adsorption, Alternative, Aqueous Solution, Batch Method, Capacity, Co²⁺, Coal, Coal Fly Ash, Concentration, Cu²⁺, Data, Equilibrium, Experimental, Fly Ash, Heavy Metal, Heavy Metal Ions, Ion Exchange, Ion-Exchange, Kinetic, Kinetics, Kinetics Model, Langmuir, Langmuir Model, Mechanism, Metal, Metal Ions, Model, Ni²⁺, Performance, pH, pH Value, Pseudo First Order, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-First-Order, Pseudo-First-Order Kinetics, Pseudo-Second-Order, Pseudo-Second-Order Kinetics, Removal, Solution, Sorption, Sorption Capacity, Synthesis, Temperature, Treatment, Value, Wastewater, Zeolite, Zn²⁺

? Malkoc, E. and Nuhoglu, Y. (2005), Investigations of nickel(II) removal from aqueous solutions using tea factory waste. Journal of Hazardous Materials, 127 (1-3), 120-128.

Full Text: 2005\J Haz Mat127, 120.pdf

Abstract: This paper presents the data for the effect of adsorbent dose, initial metal concentration, solution pH, agitating rate and temperature on the adsorption of nickel(II) on waste tea. Batch adsorption studies have been carried out. The equilibrium nature of nickel(II) adsorption at different temperature (25-60C) has been described by the Freundlich and Langmuir isotherm. The adsorption capacity (Q(0)) calculated from Langmuir isotherm was 15.26 mg Ni(II) g^-1 at initial pH of 4.0 at 25C. The results of the thermodynamic investigations indicate that the adsorption reactions are spontaneous (G < 0), slightly endothermic (H > 0) and irreversible (S > 0). (c) 2005 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorbent Dose, Adsorption, Adsorption Capacity, Aqueous Solutions, Batch Adsorption, Capacity, Concentration, Data, Endothermic, Equilibrium, Freundlich, Investigations, Isotherm, Langmuir, Langmuir Isotherm, Metal, Ni(II), Nickel, Nickel(II), pH, Removal, Solution, Solutions, Temperature, Thermodynamic, Waste, Waste Tea

? El-Kamash, A.M., Zaki, A.A. and El Geleel, M.A. (2005), Modeling batch kinetics and thermodynamics of zinc and cadmium ions removal from waste solutions using synthetic zeolite A. Journal of Hazardous Materials, 127 (1-3), 211-220.

Full Text: 2005\J Haz Mat127, 211.pdf

Abstract: The sorptive removal of zinc and cadmium ions from aqueous solutions using synthetic zeolite A was investigated. Experiments were carried out as a function of solute concentration and temperature (298-333 K). Several kinetic models were used to test the experimental rate data and to examine the controlling mechanism of the sorption process. Various Parameters such as effective diffusion coefficient. activation energy and entropy of activation were evaluated. Equilibrium sorption data were analyzed using Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. Of the model tested, both Freundlich and D-R isotherm expressions were found to give better fit to the experimental equilibrium data compared to Langmuir model. The mean free energy is in all cases in the range corresponding to the ion exchange type of sorption. The results indicated that synthetic zeolite A can be used as an efficient ion exchange material for the removal of zinc and cadmium ions from industrial and radioactive wastewaters. (c) 2005 Elsevier B.V. All rights reserved.

Keywords: Modeling, Kinetics, Thermodynamics, Sorption, Heavy Metals, Zeolite, Exchange Processes, Natural Zeolites, Water, Sorption, Strontium, Cr³⁺

? Akhtar, M., Bhanger, M.I., Iqbal, S. and Hasany, S.M. (2006), Sorption potential of rice husk for the removal of 2,4-dichlorophenol from aqueous solutions: Kinetic and thermodynamic investigations. Journal of Hazardous Materials, 128 (1), 44-52.

Full Text: 2006\J Haz Mat128, 44.pdf

Abstract: The sorption potential of chemically and thermally treated rice husk (RHT) for the removal of 2,4-dichlorophenol (DCP) from aqueous solutions has been investigated. Sorption of DCP by rice husk was observed over a wide pH range of 1–10. The effect of contact time between liquid and solid phases, sorbent dose, pH, concentration of sorbate and temperature on the sorption of DCP onto rice husk has been studied. The pore area and average pore diameter of RHT by BET method are calculated to be 17±0.6 m²g⁻¹ and 51.3±1.5 nm, respectively. Maximum sorption (98±1.2%) was achieved for RHT from 6.1×10⁻⁵ mol dm⁻³ of sorbate solution using 0.1 g of rice husk for 10 min agitation time at pH 6 and 303 K, which is comparable to activated carbon commercial (ACC) 96.6±1.2%, but significantly higher than chemically treated rice husk (RHCT) 65±1.6% and rice husk untreated (RHUT) 41±2.3%. The sorption data obtained at optimized conditions was subjected to Freundlich, Langmuir and Dubinin–Radushkevich (D–R) isotherms. Sorption intensity 1/n (0.31 0.01) and sorption capacity multilayer Cm (12.0±1.6 mmol g⁻¹) have been evaluated using Freundlich sorption isotherm, whereas the values of sorption capacity monolayer Q (0.96±0.03 mmol g⁻¹) and binding energy, b, (4.5±1.0)×104 dm³ mol⁻¹ have been estimated by Langmuir isotherm. The Langmuir constant, b, was also used to calculate the dimensionless factor, RL, in the concentration range (0.6–6.1)×10⁻⁴ mol dm⁻³, suggesting greater sorption at low concentration. D–R sorption isotherm was employed to calculate sorption capacity Xm (2.5±0.07 mmol g⁻¹) and sorption energy E (14.7±0.13 kJ mol⁻¹). Lagergren and Morris–Weber equations were employed to study kinetics of sorption process using 0.2 g of RHT, 25 cm³ of 0.61×10−4 mol dm−3 sorbate concentration at pH 6, giving values of first-order rate constant, k, and rate constant of intraparticle transport, Rid, (0.48±0.04 min⁻¹ and 6.8±0.8 nmolg⁻¹ min^−1/2, respectively) at 0.61×10⁻⁴ mol dm⁻³ solution concentration of DCP, 0.1 g RHT, pH 6 and 2–10 min of agitation time. For thermodynamic studies, sorption potential was examined over temperature range 283–323 K by employing 6.1×10⁻⁴ mol dm⁻³ solution concentration of DCP, 0.1 g RHT at pH 6 and 10 min of agitation time and values of ΔH (−25±1 kJ mol⁻¹), ΔS (−61±4 J mol⁻¹ K⁻¹) and ΔG303K (−7.1±0.09 kJ mol⁻¹) were computed. The negative values of enthalpy, entropy, and free energy suggest that the sorption is exothermic, stable, and spontaneous in nature.

Keywords: Rice (Oryza sativa) Husk, 2,4-Dichlorophenol, Sorption Potential, HPLC, Kinetics, Thermodynamics

? Subramanian, B. and Gupta, G. (2006), Adsorption of trace elements from poultry litter by montmorillonite clay. Journal of Hazardous Materials, 128 (1), 80-83.

Full Text: 2006\J Haz Mat128, 80.pdf

Abstract: Poultry litter (PL) is used as fertilizer on agricultural lands because of its high nutrient content. However, the litter also contains trace elements such as As, Cd, Cu, Pb, and Zn. On land application of PL, these trace elements may be absorbed by crops, leach into groundwater, or enter the aquatic system as run-off. The objective of this research was to study the effect of the addition of montmorillonite clay-mineral (CM) in reducing the release of trace elements from PL. Cd, Cu, and Zn showed significant decreases of 29, 34, and 22%, respectively, in PL aqueous leachate (compared with the control-PL without CM) on mixing with 0.05 g CM but no change in As, Co, and Cr concentrations was observed. Lead showed a significant increase in PL aqueous leachate on mixing with 0.2 g CM but Pb concentration was two orders of magnitude less than in CM aqueous leachate alone. On washing, the settled precipitate (PL+CM) in the centrifuge tubes with water (desorption study) most of the adsorbed metals (Cd 85%, Cu 61%, and Zn 100%) were released. The results of this study show that the addition of CM resulted in significant adsorption of Cd and Cu from PL.

Keywords: Poultry Litter, Montmorillonite, Trace Elements, Copper, Cadmium, Zinc, Sorption

? Wang, S.R., Jin, X.C., Bu, Q.Y., Zhou, X.N. and Wu, F.C. (2006), Effects of particle size, organic matter and ionic strength on the phosphate sorption in different trophic lake sediments. Journal of Hazardous Materials, 128 (2-3), 95-105.

Full Text: 2006\J Haz Mat128, 95.pdf

Abstract: The trophic status and development of lake system is significantly influenced by the phosphate sorption at the sediment–water interface. The effects of organic matter, particle size and ionic strength on the phosphate sorption by sediments were investigated in this study. The results show that maximum phosphate sorption capacity (Q_max), equilibrium phosphate concentration (EPC0), phosphate sorption efficiency (k) and phosphate sorption rate decreased as particle size increased for all the studied sediments. But the reliable desorbed phosphorus (RDP) increased. Q_max, EPC0, k and RDP of different particle size fractions varied and there were no obvious differences among different trophic lake sediments. Qmax, EPC0 increased while k and RDP decreased as the pollution level of lake sediment increased. The phosphate sorption mainly occurred within 0.5 h. Power function and simple Elovich models were the best kinetic models for the phosphate sorption of the different particle size fractions. Qmax and phosphate sorption rate decreased with the decreasing of organic matter content of sediments and the increasing of ionic strength. This study suggests that ionic strength and organic matter had similar effects on the phosphate sorption for different trophic lake sediments.

Keywords: Phosphate Sorption, Organic Matter, Particle Size, Ionic Strength, Sediment, Lake

? Zhang, W.M., Chen, J.L., Pan, B.C., Zhang, Q.X. and Zhang, B. (2006), Synergistic adsorption of phenol from aqueous solution onto polymeric adsorbents. Journal of Hazardous Materials, 128 (2-3), 123-129.

Full Text: 2006\J Haz Mat128, 123.pdf

Abstract: Adsorption of phenol from aqueous solution onto a nonpolar adsorbent, aminated adsorbent and weak base adsorbent (Amberlite XAD4, NDA103 and Amberlite IRA96C, respectively) at temperatures from 293 to 313 K was studied for the weak interactions between the phenol molecules and the polymeric adsorbents. Isotherms of Langmuir and Freundlich equation with characteristic parameters for different adsorbents were well fitted to the batch equilibrium adsorption data. The adsorption capacity on NDA103 driven by hydrogen bonding and van der Waals interaction together is higher than that on IRA96C driven by hydrogen bonding interaction only and on XAD4 driven by van der Waals interaction only. For evaluating synergistic adsorption for phenol–water systems onto polymeric adsorbents, the adsorption capacity is normalized to the amounts of specific surface area and amino groups of adsorbents. The synergistic effect with other weak interactions would contribute more to the adsorption as acting simultaneously than that of acting individually.

Keywords: Polymeric Adsorbent, Phenol, Adsorption Behavior, Synergistic Effect

? Baskaralingam, P., Pulikesi, M., Elango, D., Ramamurthi, V. and Sivanesan, S. (2006), Adsorption of acid dye onto organobentonite. Journal of Hazardous Materials, 128 (2-3), 138-144.

Full Text: 2006\J Haz Mat128, 138.pdf

Abstract: Removal of Acid Red 151 from aqueous solution at different dye concentrations, adsorbent doses and pH has been studied. The bentonite clay has been modified using cationic surfactants, which has been confirmed using XRD and FT-IR analyses. Experimental result has shown that the acidic pH favours the adsorption. The adsorption isotherms are described by means of Langmuir and Freundlich isotherms. The adsorption capacity has been found to be 357.14 and 416.66 mg g⁻¹ for the cetyldimethylbenzylammonium chloride-bentonite (CDBA-bent) and cetylpyridinium chloride-bentonite (CP-bent), respectively. Kinetic studies show that the adsorption followed second-order kinetics.

Keywords: Adsorption, Acid dye, Organoclay, Isotherms, Kinetics

? Önal, Y., Akmil-Başar, Ç., Eren, D., Sarıcı-Özdemir, Ç. and Depci, T. (2006), Adsorption kinetics of malachite green onto activated carbon prepared from Tunçbilek lignite. Journal of Hazardous Materials, 128 (2-3), 150-157.

Full Text: 2006\J Haz Mat128, 150.pdf

Abstract: Adsorbent (T₃K618) has been prepared from Tunçbilek lignite by chemical activation with KOH. Pore properties of the activated carbon such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by t-plot based on N₂ adsorption isotherm. The N₂ adsorption isotherm of malachite green on T₃K618 is type I. The BET surface area of the adsorbent which was primarily contributed by micropores was determined 1000 m²/g. T₃K618 was used to adsorb malachite green (MG) from an aqueous solution in a batch reactor. The effects of initial dye concentration, agitation time, initial pH and adsorption temperature have been studied. It was also found that the adsorption isotherm followed both Freundlich and Dubinin–Radushkevich models. However, the Freundlich gave a better fit to all adsorption isotherms than the Dubinin–Radushkevich. The kinetics of adsorption of MG has been tested using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. Results show that the adsorption of MG from aqueous solution onto micropores T₃K618 proceeds according to the pseudo-second-order model. The intraparticle diffusion of MG molecules within the carbon particles was identified to be the rate-limiting step. The adsorption of the MG was endothermic (ΔH° = 6.55–62.37 kJ/mol) and was accompanied by an increase in entropy (ΔS° = 74–223 J/mol K) and a decrease in mean value of Gibbs energy (ΔG° = −6.48 to −10.32 kJ/mol) in the temperature range of 20–50 °C.

Keywords: Activated Carbon, Activation, Adsorbent, Adsorption, Adsorption Isotherm, Adsorption Isotherms, Adsorption Kinetics, Agitation, Aqueous Solution, Batch, Batch Reactor, BET, BET Surface Area, Carbon, Chemical, Chemical Activation, Concentration, Diffusion, Distribution, Dye, Endothermic, Energy, Entropy, Freundlich, Intraparticle Diffusion, Isotherm, Isotherms, Kinetics, Kinetics of Adsorption, Koh, Lignite, Malachite Green, Mg, Model, Models, Particles, pH, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Rate Limiting Step, Rate-Limiting Step, Reaction Kinetics, Size, Solution, Surface, Surface Area, Temperature, Value, Volume

? Mittal, A. (2006), Use of hen feathers as potential adsorbent for the removal of a hazardous dye, Brilliant Blue FCF, from wastewater. Journal of Hazardous Materials, 128 (2-3), 233-239.

Full Text: 2006\J Haz Mat128, 233.pdf

Abstract: Waste material, hen feather, a biosorbent, was successfully utilized in removing a water-soluble hazardous triphenylmethane dye, Brilliant Blue FCF from wastewater. The paper incorporates effect of pH, temperature, amount of adsorbent, contact time, concentration of adsorbate, etc. The adsorption data validates Langmuir and Freundlich adsorption isotherms and on the basis of these isotherms thermodynamic parameters like Gibb’s free energy, change in enthalpy and entropy were calculated. Kinetics of the ongoing adsorption was also monitored and specific rate constants for the involved process were calculated at different temperatures. Kinetic measurements suggest a first order adsorption kinetics and adsorption was found to be applicable via film diffusion process in the entire concentration range.

Keywords: Hen Feather, Brilliant Blue FCF, Adsorption, Kinetics, Waste mzaterial, Biosorbent

? Gupta S.S. and Bhattacharyya, K.G. (2006), Removal of Cd(II) from aqueous solution by kaolinite, montmorillonite and their poly(oxo zirconium) and tetrabutylammonium derivatives. Journal of Hazardous Materials, 128 (2-3), 247-257.

Full Text: 2006\J Haz Mat128, 247.pdf

Abstract: Kaolinite, montmorillonite and their poly(oxo zirconium) and tetrabutylammonium derivatives have been used in this work for removing Cd(II) from aqueous solution. Batch adsorption studies were carried out under various Cd(II) concentrations, amount of clay adsorbents, pH, interaction time and temperature. The uptake of the metal was initially very fast, but gradually slowed down indicating diffusion into the interior of the adsorbent particles. The adsorption processes were more akin towards second order reaction mechanism. The suitability of the adsorbent was tested by fitting the adsorption data with Langmuir and Freundlich isotherms, which gave good fits with both isotherms. Adsorption was poor in strongly acidic solution but was improved in alkaline medium and continuously increased with rise in pH. The values of the thermodynamic parameters, ΔH, ΔS and ΔG, indicated the interactions to be thermodynamically favourable.

Keywords: Kaolinite, Montmorillonite, Poly(Oxo Zirconium) Clay, Tetrabutylammonium Clay, Sorption Isotherm

? Karaca, S., Gürses, A., Ejder, M. and Açıkyıldız, M. (2006), Adsorptive removal of phosphate from aqueous solutions using raw and calcinated dolomite. Journal of Hazardous Materials, 128 (2-3), 273-279.

Full Text: 2006\J Haz Mat128, 273.pdf

Abstract: This study explored the feasibility of utilizing raw and calcinated dolomite under CO₂ atmosphere for phosphate removal in laboratory experiments. The experimental work emphasized the evaluation of phosphate adsorption characteristics of this adsorbent material. Studies were conducted to delineate the effect of contact time, initial phosphate concentration, temperature, pH, stirring speed, adsorbent dose and calcination temperature. Phosphate removal decreased with increasing temperature and slightly increased with increasing of pH. The observed decrease in the adsorption capacity with increase of the temperature from 20 to 40 and to 60 °C indicates that the low temperatures favor the phosphate removal by adsorption onto dolomite. Phosphate removal was seen to decrease with increasing calcination temperature due to the structural changes occurring in the structure and pore size distribution of dolomite samples during calcination. The experimental data obtained were applied to the Freundlich, Langmuir, BET, Halsey, Harkins–Jura, Smith and Henderson isotherm equations to test the fit of these equations to raw and calcinated dolomite samples. By considering the experimental results and adsorption models applied in this study, it can be concluded that adsorption of phosphate occurs predominantly through physical interactions, and the dolomite sample has a heteroporous structure. The large values of the constants for Henderson equation and the high value of ym obtained from BET equation indicate the microporous structure is more stable in raw and calcinated dolomite samples.

Keywords: Phosphate Adsorption, Dolomite, Calcination, Isotherm Models

? Yadav, A.K., Kaushik, C.P., Haritash, A.K., Kansal, A. and Rani, N. (2006), Defluoridation of groundwater using brick powder as an adsorbent. Journal of Hazardous Materials, 128 (2-3), 289-293.

Full Text: 2006\J Haz Mat128, 289.pdf

Abstract: Defluoridation of groundwater using brick powder as an adsorbent was studied in batch process. Different parameters of adsorption, viz. effect of pH, effect of dose and contact time were selected and optimized for the study. Feasible optimum conditions were applied to two groundwater samples of high fluoride concentration to study the suitability of adsorbent in field conditions. Comparison of adsorption by brick powder was made with adsorption by commercially available activated charcoal. In the optimum condition of pH and dose of adsorbents, the percentage defluoridation from synthetic sample, increased from 29.8 to 54.4% for brick powder and from 47.6 to 80.4% for commercially available activated charcoal with increasing the contact time starting from 15 to 120 min. Fluoride removal was found to be 48.73 and 56.4% from groundwater samples having 3.14 and 1.21 mg l⁻¹ fluoride, respectively, under the optimized conditions. Presence of other ions in samples did not significantly affect the deflouridation efficiency of brick powder. The optimum pH range for brick powder was found to be 6.0–8.0 and adsorption equilibrium was found to be 60 min. These conditions make it very suitable for use in drinking water treatment. Deflouridation capacity of brick powder can be explained on the basis of the chemical interaction of fluoride with the metal oxides under suitable pH conditions. The adsorption process was found to follow first order rate mechanism as well as Freundlich isotherm.

Keywords: Defluoridation, Adsorption, Brick Powder (BP), Commercially Available

? Lee, C.I., Yang, W.F. and Chiou, C.S. (2006), Utilization of water clarifier sludge for copper removal in a liquid fluidized-bed reactor. Journal of Hazardous Materials, 129 (1-3), 58-63.

Full Text: 2006\J Haz Mat129, 58.pdf

Abstract: A method was used to investigate the potential for using water clarifier sludge to remove copper in a fluidized-bed reactor (FBR). This study was conducted to evaluate the removal of copper in an aquatic system without prior treatment. Chemical analyses of water clarifier sludge through inductively coupled plasma-atomic emission spectrophotometry indicated that silicon, aluminum and iron oxides made up more than 84% of this average composition, similar to the composition of clay. The experimental results indicated that the copper removal efficiency was highly dependent on the pH. pH values also influence the character of the water clarifier sludge. After the copper was adsorbed by the water clarifier sludge, the pH of the solution was slightly increased. In the FBR, the copper removal efficiency reached 90% when the initial copper concentration was 20 mg, L, the pH was 4 and the operating time was 60 min. In addition, copper precipitation occured on the surface of clarifier sludge when the initial copper concentration was 20 mg, L and the pH was 7.0. The kinetics of copper ion adsorption at pH 5 showed that 94% copper ion was removed in 60 min and the adsorption equilibrium was attained in 5 h. The mechanisms of adsorption of copper ions on water clarifier sludge including the formation of surface complexation and surface precipitate. (c) 2005 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption, Adsorption Equilibrium, Aluminum, Analyses, Aqueous-Solutions, Batch, Character, Clay, Complexation, Composition, Concentration, Copper, Copper Ion, Copper Ions, Copper Removal, Efficiency, Emission, Equilibrium, Experimental, Fluidized Bed, Fluidized-Bed Reactor, Generation, Heavy-Metal Ions, Inductively Coupled Plasma-Atomic Emission, Influence, Ion Adsorption, Ions, Iron, Iron Oxides, Kinetics, Liquid, Low-Cost Adsorbents, Mechanisms, Oxides, Peat, pH, Potential, Precipitation, Removal, Removal Efficiency, Rights, Silicon, Sludge, Solution, Sorption, Spectrophotometry, Surface, Surface Complexation, Time, Treatment, Values, Waste-Water, Water, Water Clarifier Sludge

? Kurniawan, T.A., Lo, W.H. and Chan, G.Y.S. (2006), Physico-chemical treatments for removal of recalcitrant contaminants from landfill leachate. Journal of Hazardous Materials,