Personal Research Database

Full Text: 2009\J Haz Mat163, 1254.pdf

Abstract: Present study deals with the adsorption of Pb(II) from aqueous solution on rice husk ash. Rice husk is a by-product generally obtained from rice mill. Rice husk ash is a solid obtained after burning of rice husk. Batch studies were performed to evaluate the influences of various experimental parameters like pH, initial concentration, adsorbent dosage, contact time and the effect of temperature. Optimum conditions for Pb(II) removal were found to be pH 5, adsorbent dosage 5 g/L of solution and equilibrium time 1 h. Adsorption of Pb(II) followed pseudo-second-order kinetics. The effective diffusion coefficient is of the order of 10^-10 m²/s. The equilibrium adsorption isotherm was better described by Freuindlich adsorption isotherm model. The adsorption capacity (q_max) of rice husk ash for Pb(II) ions in terms of monolayer adsorption was 91.74 mg/g. The change of entropy (ΔS) and enthalpy (ΔH) were estimated at 0.132 kJ/(mol K) and 28.923 kJ/mol respectively. The negative value of Gibbs free energy (ΔG) indicates feasible and spontaneous adsorption of Pb(II) on rice husk ash. The value of the adsorption energy (E), calculated using Dubinin-Radushkevich isotherm, was 9.901 kJ/mol and it indicated that the adsorption process was chemical in nature. Application study was also carried out to find the suitability of the process in waste water treatment operation. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption Isotherm, Aqueous-Solution, Bagasse Fly-Ash, Effective Diffusivity, Equilibrium, Heavy-Metals, Isotherm, Kinetics, Removal, Rice Husk Ash, Sorption Energy, Sugar-Industry Waste, Water

? Sharma, N., Kaur, K. and Kaur, S. (2009), Kinetic and equilibrium studies on the removal of Cd²⁺ ions from water using polyacrylamide grafted rice (Oryza sativa) husk and (Tectona grandis) saw dust. Journal of Hazardous Materials, 163 (2-3), 1338-1344.

Full Text: 2009\J Haz Mat163, 1338.pdf

of heavy metals has resulted in an increased flux of metallic substances into the aquatic environment which poses a danger to human health. The present work relates to the removal of cadmium ions by treatment with polyacrylamide grafted rice (Oryza sativa) husk, saguan (Tectona grandis) saw dust. The drinking water guideline value recommended by WHO for cadmium is 0.005 ppm. The adsorbent has been prepared by treatment of rice husk, saw dust with acrylamide. Removal has been studied at various pH values for different times of contact and adsorbate concentrations and is found to be pH-dependent, maximum removal occurs at pH 9 and at a contact time of 180 min for both the adsorbents. The results were found to be consistent with both the Langmuir and Freundlich isotherm models. The value of n (rate constant) determined at pH 9 has been found to be 1 (within experimental limits). This is further substantiated by applying the Lagergren model. The intra-particle diffusion constants were determined by the Morris-Weber model. Continous flow column studies have also been undertaken and the breakthrough characteristics were determined. Desorption has been affected with 0.5 M HCl. The results suggest that both polyacrylamide grafted rice husk, saw dust can be used as efficient and cost effective adsorbents for cadmium ion removal. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorbents, Adsorption, Aquatic Environment, Aqueous-Solutions, Breakthrough, Cadmium, Cadmium Ions, Cd²⁺, Characteristics, Column, Column Studies, Contact, Contaminated Water, Copper, Cost, Cost-Effective, Desorption, Diffusion, Drinking, Drinking Water, Dust, Environment, Equilibrium, Equilibrium Studies, Experimental, Flow, Freundlich, Freundlich Isotherm, Grafted, Guideline, Health, Heavy Metals, Human, Human Health, Intra-Particle Diffusion, Intraparticle, Intraparticle Diffusion, Ions, Isotherm, Isotherm Models, Kinetic, Kinetics, Lagergren, Lagergren Model, Langmuir, Low-Cost, Metal-Ions, Metallic, Metals, Model, Models, Orange Waste, pH, pH-Dependent, Polyacrylamide, Polyacrylamide Grafted Rice Husk, Saw Dust, Rate Constant, Removal, Rice, Rights, Saw Dust, Time, Treatment, Value, Values, Water, Work

? Jiang, Y., Pang, H. and Liao, B. (2009), Removal of copper(II) ions from aqueous solution by modified bagasse. Journal of Hazardous Materials, 164 (1), 1-9.

Full Text: 2009\J Haz Mat164, 1.pdf

Abstract: Bagasse-based ion adsorbent was prepared by chemically modifying bagasse with acrylonitrile and hydroxylamine with the aim to enhance the ability of removal heavy metal ions from wastewater. The purified modified materials were characterized by Fourier transform infrared (FT-IR). Batch experiments of Cu(II) ions (Cu²⁺) adsorption on the bagasse adsorbent were performed. Effects of the adsorbent dosage, initial pH of the solution, temperature of the Cu²⁺ solution, and initial Cu²⁺ concentration on the adsorption of Cu²⁺ were studied, respectively. Langmuir and Freundlich models were applied to describe the adsorption isotherm of Cu²⁺ by bagasse adsorbent. The results indicated that Langmuir model fitted the adsorption equilibrium data better than the Freundlich isotherm model. Two kinetic models, including pseudo-first-order and pseudo-second-order, were also used to analyze the Cu²⁺ adsorption process, and the results showed that the pseudo-second-order with correlation coefficients greater than 0.999 was more suitable than pseudo-first-order. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorbents, Adsorption, Agricultural By-Products, Bagasse, Cu²⁺, Equilibrium, Equilibrium, Heavy-Metal, Kinetics, Kinetics, Metal-Ions, Modification, Sawdust Adsorption, Sorption, Waste-Water, Wheat Bran

? Uddin, M.T., Islam, M.A., Mahmud, S. and Rukanuzzaman, M. (2009), Adsorptive removal of methylene blue by tea waste. Journal of Hazardous Materials, 164 (1), 53-60.

Full Text: 2009\J Haz Mat164, 53.pdf

Abstract: The potentiality of tea waste for the adsorptive removal of methylene blue, a cationic dye, from aqueous solution was studied. Batch kinetics and isotherm studies were carried out under varying experimental conditions of contact time, initial methylene blue concentration, adsorbent dosage and pH. The nature of the possible adsorbent and methylene blue interactions was examined by the FTIR technique. The pH(pzc) of the adsorbent was estimated by titration method and a value of 4.3±0.2 was obtained. An adsorption-desorption study was carried out resulting the mechanism of adsorption was reversible and ion-exchange. Adsorption equilibrium of tea waste reached within 5 h for methylene blue concentrations of 20-50 mg/L. The sorption was analyzed using pseudo-first-order and pseudo-second order kinetic models and the sorption kinetics was found to follow a pseudo-second order kinetic model. The extent of the dye removal increased with increasing initial dye concentration. The equilibrium data in aqueous solutions were well represented by the Langmuir isotherm model. The adsorption capacity of methylene blue onto tea waste was found to be as high as 85.16 mg/g, which is several folds higher than the adsorption capacity of a number of recently studied in the literature potential adsorbents. Tea waste appears as a very prospective adsorbent for the removal of methylene blue from aqueous solution. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbons, Adsorption, Aqueous-Solutions, Aspergillus-Niger, Basic-Dyes, Fixed-Bed, Fly-Ash, Isotherms, Kinetics, Kinetics, Methylene Blue, Process Design, Solid-Waste, Tea Waste, Textile Effluents

? Hovsepyan, A. and Bonzongo, J.C.J. (2009), Aluminum drinking water treatment residuals (Al-WTRs) as sorbent for mercury: Implications for soil remediation. Journal of Hazardous Materials, 164 (1), 73-80.

Full Text: 2009\J Haz Mat164, 73.pdf

Abstract: The potential of readily available and non-hazardous waste material, aluminum drinking water treatment residuals (Al-WTRs), to efficiently sorb and immobilize mercury (Hg) from aqueous solutions was evaluated. Al-WTR samples with average specific surface area of 48 m²/g and internal micropore surface area of 120 m²/g were used in a series of batch sorption experiments. Obtained sorption isotherms indicated a strong affinity of Hg for Al-WTRs. Using the Langmuir adsorption model, a relatively high maximum sorption capacity of 79 mg Hg/g Al-WTRs was determined. Sorption kinetic data was best fit to a pseudo-first-order model, while the use of the Weber-Morris and Bangham models suggested that the intraparticle diffusion could be the rate-limiting step. Also, Al-WTRs effectively immoblized Hg in the pH range of 3-8. The results from these short-term experiments demonstrate that Al-WTRs can be effectively used to remove Hg from aqueous solutions. This ability points to the potential of Al-WTRs as a sorbent in soil remediation techniques based on Hg-immobilization. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorptive Removal, Aqueous-Solution, Fibers, Heavy-Metal Toxicity, Immobilization, Immobilization, Mercury, Oxides, Phosphorus, Sludge, Soil Remediation, Sorption, Surface Characterization, Water Treatment Residuals, Waterworks Sludge

? Zainal, Z., Hui, L.K., Hussein, M.Z., Abdullah, A.H. and Hamadneh, I.R. (2009), Characterization of TiO₂-Chitosan/Glass photocatalyst for the removal of a monoazo dye via photodegradation-adsorption process. Journal of Hazardous Materials, 164 (1), 138-145.

Full Text: 2009\J Haz Mat164, 138.pdf

Abstract: In this paper, the newly explored TiO₂-Chitosan/Glass was suggested as a promising alternative material to conventional means of wastewater treatment. Characterization of TiO₂-Chitosan/Glass photocatalyst was studied with SEM-EDX, XRD, and Fourier transform infrared spectroscopy (FTIR) analysis. The combination effect of photodegradation-adsorption process for the removal of methyl orange (MO), an acid dye of the monoazo series occur promisingly when four layers of TiO₂-Chitosan/Class photocatalyst was used for MO removal. Approximately, 87.0% of total MO removal was achieved. The reactive -NH₂, -OH, and metal oxide contents in the prepared photocatalyst responsible for the photodegradation-adsorption effect were confirmed by FTIR study. Similarly, MO removal behavior was well supported by SEM-EDX and XRD analysis. Significant dependence of MO removal on the TiO₂-Chitosan loading can be explained in terms of relationship between quantum yield of photocatalytic reactions and photocatalyst structure/activity. Hence, the research work done thus far suggests a new method, having both the advantages of photodegradation-adsorption process in the abatement of various wastewater pollutants. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Acid-Solutions, Adsorption, Anionic Dyes, Aqueous TiO₂ Suspensions, Chitosan, Gel-Supported TiO₂, Linked Chitosan Beads, Metal-Ions, Photodegradation, Removal, TiO₂-Assisted Photodegradation, Titanium Dioxide, Titanium-Dioxide, Visible Light, Visible-Light Irradiation, Waste-Water

? Iqbal, M., Saeed, A. and Zafar, S.I. (2009), FTIR spectrophotometry, kinetics and adsorption isotherms modeling, ion exchange, and EDX analysis for understanding the mechanism of Cd²⁺ and Pb²⁺ removal by mango peel waste. Journal of Hazardous Materials, 164 (1), 161-171.

Full Text: 2009\J Haz Mat164, 161.pdf

Abstract: Mango peel waste (MPW) was evaluated as a new sorbent for the removal of Cd²⁺ and Pb²⁺ from aqueous solution. The maximum sorption capacity of Cd²⁺ and Pb²⁺ was found to be 68.92 and 99.05 mg g^-1, respectively. The kinetics of sorption of both metals was fast, reaching at equilibrium in 60 min. Sorption kinetics and equilibria followed pseudo-second order and Langmuir adsorption isotherm models. FTIR analysis revealed that carboxyl and hydroxyl functional groups were mainly responsible for the sorption of Cd²⁺ and Pb²⁺. Chemical modification of MPW for blocking of carboxyl and hydroxyl groups showed that 72.46% and 76.26% removal of Cd²⁺ and Pb²⁺, respectively, was due to the involvement of carboxylic group, whereas 26.64% and 23.74% was due to the hydroxyl group. EDX analysis of MPW before and after metal sorption and release of cations (Ca²⁺, Mg²⁺, Na⁺, K⁺) and proton H+ from MPW with the corresponding uptake of Cd²⁺ and Pb²⁺ revealed that the main mechanism of sorption was ion exchange. The regeneration experiments showed that the MPW could be reused for five cycles without significant loss in its initial sorption capacity. The study points to the potential of new use of MPW as an effective sorbent for the removal of Cd²⁺ and Pb²⁺ from aqueous solution. (C) 2008 Published by Elsevier B.V.

Keywords: Aqueous-Solution, Biosorbent, Biosorption, Cadmium, Cadmium(II), Cd(II), Equilibrium, Heavy-Metals, Ion Exchange, Lead, Lead Ions, Mango Peel Waste, Pb(II), Sorption, Sorption Mechanism

? Doğan, M., Abak, H. and Alkan, M. (2009), Adsorption of Methylene blue onto hazelnut shell: Kinetics, mechanism and activation parameters. Journal of Hazardous Materials, 164 (1), 172-181.

Full Text: 2009\J Haz Mat164, 172.pdf

Abstract: The adsorption kinetics of methylene blue (MB) on the hazelnut shell with respect to the initial dye concentration, pH, ionic strength, particle size and temperature were investigated. The rate and the transport/kinetic processes of MB adsorption were described by applying the first-order Lagergren, the pseudo-second-order. mass transfer coefficient and the intraparticle diffusion models. Kinetic studies showed that the kinetic data were well described by the pseudo-second-order kinetic model. Significant increases in initial adsorption rate were observed with the increase in temperature followed by pH and initial MB concentration. The intraparticle diffusion was found to be the rate-limiting step in the adsorption process. Adsorption activation energy was calculated to be 45.6 kJ mol^-1. The values of activation parameters such as free energy (ΔG(center dot)), enthalpy (ΔH-center dot) and entropy (ΔS-center dot) were also determined as 83.4 kJ mol^-1, 42.9 kJ mol^-1 and -133.5 J mol^-1 K^-1, respectively. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aqueous-Solutions, Basic-Dyes, Coir Pith, Color Removal, Congo-Red, Dye Adsorption, Fly-Ash, Hazelnut Shell, Kinetic, Kinetics, Leaf Powder, Mechanism and Activation Parameters, Methylene Blue, Textile Effluents, Waste-Water

? Tor, A., Danaoglu, N., Arslan, G. and Cengeloglu, Y. (2009), Removal of fluoride from water by using granular red mud: Batch and column studies. Journal of Hazardous Materials, 164 (1), 271-278.

Full Text: 2009\J Haz Mat164, 271.pdf

Abstract: This paper describes the removal of fluoride from water using granular red mud (GRM) according to batch and column adsorption techniques. For the batch technique, the experiments demonstrated that maximum fluoride removal was obtained at a pH of 4.7 and it took 6 h to attain equilibrium and equilibrium time did not depend upon the initial fluoride concentration. Kinetics data were fitted with pseudo-second-order model. The Redlich-Peterson and Freundlich isotherm models better represented the adsorption data in comparison to the Langmuir model. Column experiments were carried out under a constant influent concentration and bed depth, and different flow rates. The capacities of the breakthrough and exhaustion points decreased with increase of the flow rate. Thomas model was applied to the experimental results. The modelled breakthrough curves were obtained, and they were in agreement with the corresponding experimental data. The column adsorption was reversal and the regeneration operation was accomplished by pumping 0.2 M of NaOH through the loaded GRM-column. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption, Alumina, Anion-Exchange Membranes, Aqueous-Solution, Arsenate, Donnan Dialysis, Drinking-Water, Fluoride Removal, Granular Red Mud, Ion-Exchange, Kinetics, Silica, Sorption

? Dimović, S., Smičiklas, I., Plećaš, I., Antonović, D. and Mitrić, M. (2009), Comparative study of differently treated animal bones for Co²⁺ removal. Journal of Hazardous Materials, 164 (1), 279-287.

Full Text: 2009\J Haz Mat164, 279.pdf

Abstract: The objective of the present study was the evaluation of differently treated bovine bones for Co²⁺ removal from aqueous media. Powdered bones (B), as well as samples prepared by H₂O₂ oxidation (BH₂O₂) and annealing at 400-1000C (B400-B1000), were tested as sorbent materials. A combination of XRD, FTIR spectroscopies, DTA/TGA analyses, specific surface area (S-p) and point of zero charge (pH(PZC)) measurements was utilized for physicochemical characterization of sorbents. Sorption of Co²⁺ was studied in batch conditions as a function of pH, contact time and Co²⁺ concentration. Initial pH values in the range4-8 were found optimal for sorption experiments. Equilibrium time of 24 h was required in all investigated systems. The maximum sorption capacities differ significantly from 0.078 to 0.495 mmol/g, whereas the affinity towards Co²⁺ decreased in the order: B400 > BH₂O₂ > B600 > B > B800> B1000. The pseudo-second-order model and Langmuir theoretical equation were used for fitting the kinetic and equilibrium data, respectively. Ion-exchange with Ca²⁺ and specific cation sorption were identified as main removal mechanisms. The amounts of Co²⁺ desorbed from loaded bone sorbents increased with the decrease of pH as well as with the increase of Ca²⁺ concentration. Heating at 400C was found to be an optimal treatment for the production of the Co²⁺ removal agent. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Animal Bones, Aqueous-Solution, Biosorption, Cations, Charcoal, Co²⁺, Cobalt, Equilibrium, Heavy-Metals, Ion Exchange, Manganese, Sorption, Sorption, Synthetic Hydroxyapatites, Waste-Derived 11, Water Treatment

? Koivula, M.P., Kujala, K., Rönkkömäki, H. and Mäkelä, M. (2009), Sorption of Pb(II), Cr(III), Cu(II), As(III) to peat, and utilization of the sorption properties in industrial waste landfill hydraulic barrier layers. Journal of Hazardous Materials, 164 (1), 345-352.

Full Text: 2009\J Haz Mat164, 345.pdf

Abstract: The low conductivity landfill barrier layers protect the groundwater and soil by limiting the water flow through the bottom layers of the landfill material. Many materials used in hydraulic barrier layers also have sorption properties which could be used to reduce environmental risks. The adsorption of lead, chromium, copper, and arsenic to peat was studied with a batch-type test and a column test for compacted peat, both without pH adjustment in acidic conditions. Peat adsorbed all the metals well, 40000 mg/kg of lead, 13000 mg/kg of chromium, and 8400 mg/kg of copper in the column test. Arsenic was only tested in a batch-type test, and in that peat adsorbed 60 mg/kg of arsenic. The column test showed heavy metals to be adsorbed on the surface layers of the compacted peat sample, on the first centimeter of the sample. The adsorption was much greater in the column test than in the batch-type test, partly due to the different pH conditions and the buffer capacity of the peat in the column test. The liquid/solid ratio of the column experiment represented a time period of approximately 40 years in a landfill, under Finnish climate conditions. The hydraulic conductivity of the peat decreased as it was compressed, but it already met the hydraulic conductivity limits set by European Union legislation for the hydraulic barrier layer (110^-9 m/s at a pressure of 150 kPa for a 5-m layer), with a pressure of 50 kPa. The results show that peat would be an excellent material to construct compacted, low hydraulic conductivity layers with adsorption properties in, e.g. industrial waste landfills. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption, Aqueous-Solutions, Batch, Heavy Metals, Hydraulic Barrier Layer, Landfill, Metals, Moss, Peat, Removal, Water, Zinc

? Yuan, H.P., Zhang, J.H., Lu, Z.M., Min, H. and Wu, C. (2009), Studies on biosorption equilibrium and kinetics of Cd²⁺ by Streptomyces sp K33 and HL-12. Journal of Hazardous Materials, 164 (2-3), 423-431.

Full Text: 2009\J Haz Mat164, 423.pdf

Abstract: The sorption of Cd²⁺ by Streptomyces sp. K33 and HL-12 was investigated. The removal efficiency increased with pH, but no obvious differences with different temperatures. Fourier transform infrared (FT-IR) was used to characterize the interaction between Cd²⁺ and K33 and HL-12. Results revealed that the presence of amino, carboxyl, hydroxyl and carbonyl groups were responsible for the biosorption of Cd²⁺. Strain HL-12 had more changes in the functional groups than K33. Biosorption equilibrium was established earlier by strain K33 than that by HL-12, and K33 had higher adsorption ratio. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms were used to describe the adsorption experiment, Langmuir model fitted the experiment data best. Strain K33 showed greater sorption capacities with 38.49 mg Cd²⁺/g dry cells. Pseudo-first-order and second-order kinetic models were used to describe the kinetic data, and second-order kinetic model fitted better. About 70% recovery of Cd²⁺ could be obtained at pH ≤ 3 from metal-loaded biomass of strains HL-12 and K33. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aqueous-Solution, Biomass, Biosorption, Cadmium, Cadmium, Desorption, FT-IR, Heavy-Metals, Immobilized Cells, Kinetics, Mechanism, Pseudomonas-Aeruginosa PU21, Removal, Sorption, Streptomyces sp.

? Dhaouadi, H. and M’Henni, F. (2009), Vat dye sorption onto crude dehydrated sewage sludge. Journal of Hazardous Materials, 164 (2-3), 448-458.

Full Text: 2009\J Haz Mat164, 448.pdf

Abstract: In this work, sewage sludge is used as a textile dye adsorbent. A sample of crude dehydrated sewage sludge issued from an urban wastewater treatment plant (high-rate aeration, activated sludge process, Sahline, Tunisia) is utilized for vat dye retention. The main objective of this work is to evaluate the “efficiency” of the crude material on vat dye sorption. However, no treatment to modify any of the adsorbent properties was considered. Although the relatively low specific surface area (about 3.2 m² g^-1) compared to more conventional adsorbents, the used material shows very interesting retention capacities when used with water pollutants. The pseudo, first and second order kinetic models have been used to investigate the retention mechanism. When linearized, the pseudo-second order fit, for the both used dyes, in a better way the obtained experimental results than the pseudo-first order kinetic model. For equilibrium dye uptake amount it is found that the used material has a capacity (Langmuir Freundlich monolayer) of 73.1 mg/g to fix the VAT RED 10 and 58.7 mg/g to fix the VAT ORANGE 11. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent Characterization, Adsorption, Aqueous-Solutions, Error Functions, Fixed-Bed Systems, Isotherm, Isotherm Sensitivity Analysis, Kinetic and Equilibrium Modelization, Kinetics, Methylene-Blue, Nonlinear-Regression Analysis, Removal, Sewage Sludge, Vat Dye Retention

? Tan, I.A.W., Ahmad, A.L. and Hameed, B.H. (2009), Adsorption isotherms, kinetics, thermodynamics and desorption studies of 2,4,6-trichlorophenol on oil palm empty fruit bunch-based activated carbon. Journal of Hazardous Materials,