Personal Research Database

Full Text: 2009\J Haz Mat169, 386.pdf

Abstract: Although various biosorbents have been reported effective to purify wastewaters containing heavy metals, the high tendency to decomposition in the environment makes them unsuitable for long-term persistent utilization. In this paper, a simple and new activation method was proposed to mineralize the Firmiana Simplex leaf (FSL) into an enhanced adsorbent for Pb(II) removal from aqueous solution. The leaves activated at various temperatures were characterized with BET N-2 adsorption test. FT-IR test and XRD test. After activation, the mass percent of inorganic components (including whewellite, quartz, phosphate and calcite) increased and the specific surface area increased from 0.08283 to 9.32 m²g^-1 with the increasing activation temperature (AT) from 100 to 400°C. Proper activation temperature (200°C) helps to preserve the beneficial groups (amine and carboxyl). The affinities of the adsorbents towards Pb(II) were increased with increasing AT from 300, 100, 200 to 400 degrees C according to the adsorption isotherms. The adsorbent activated at 200°C (AL2) was found most suitable for Pb(II) adsorption regarding the high yield efficiency (36.52%), high Pb(II) adsorption capacity (136.7 mg g^-1 by Langmuir model), high adsorption affinity (H type isotherm) and rapid adsorption rate (within 20 min by kinetic study). The Pb(II) removal efficiency of AL2 was obviously affected by the solution pH rather than by the adsorbent dosage. The adsorption was viewed as a chemical process based on IR spectra along with a physical process based on the correlation between the average pore size of the adsorbent and the adsorption capacity. The activation method proposed in this paper was proved effective and potentially applicable in the treatment of Pb(II) polluted wastewaters. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Leaf, Activation, Adsorption, Adsorption Capacity, Adsorption Isotherms, Adsorption Rate, Aqueous, Aqueous-Solution, Biosorbents, Biosorption, Capacity, Contamination, Decomposition, Elsevier, Equilibrium, Firmiana Simplex Leaf, FT-IR, FTIR, Groups, Heavy Metals, Heavy-Metals, IR, Isotherm, Isotherms, Kinetic, Leaves, Mechanism, Metals, N-2, Pb(II), pH, Phosphate, Removal, Sorbents, Sorption, Spectra, Surface Area, Temperature, Treatment, XRD

? Alemayehu, E. and Lennartz, B. (2009), Virgin volcanic rocks: Kinetics and equilibrium studies for the adsorption of cadmium from water. Journal of Hazardous Materials, 169 (1-3), 395-401.

Full Text: 2009\J Haz Mat169, 395.pdf

Abstract: This study was initiated to investigate the adsorption of cadmium from aqueous solution by two different rock types-Pumice (VPum) and Scoria (VSco), which are readily available in Ethiopia and other countries. The influence of operational conditions, such as particle size, adsorbent/solution ratio, contact time, cadmium initial concentration, and pH was analyzed. The competition between metals was also evaluated. The Cd(II) removal capacity was predominantly affected by the pH conditions, being increased under alkaline conditions. For both adsorbents, when particle size was 0.075-0.425 mm, the maximum Cd(H) adsorption was observed at pH 6.0 (contact time = 24 h, shaking speed = 200 rpm, adsorbent dose = 50 g L^-1). Adsorption process revealed that the initial uptake was very fast during the first 1 h. The kinetics of the interactions follows pseudo second-order. Equilibrium assays confirm that VPum has a larger capacity and affinity for Cd(II) adsorption than VSco. Both Langmuir and Freundlich models described equally well the experimental data. VPum and VSco were found to be promising material for the removal of cadmium from metal bearing water. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorbent Dose, Adsorbents, Adsorption, Aqueous Solution, Aqueous-Solutions, Cadmium, Capacity, Cd(II), Cd(II) Adsorption, Cd(II) Removal, Coated Sand, Competition, Concentration, Data, Equilibrium, Equilibrium Studies, Ethiopia, Experimental, First, Freundlich, Heavy-Metals, Ions, Kinetics, L1, Langmuir, Metal, Metals, Models, Particle Size, pH, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Pumice, Quality, Removal, Rights, Scoria, Scoria, Second Order, Second-Order, Size, Soils, Solution, Sorption, Uptake, Water

? Rosal, R., Gonzalo, M.S., Rodríguez, A. and García-Calvo, E. (2009), Ozonation of clofibric acid catalyzed by titanium dioxide. Journal of Hazardous Materials, 169 (1-3), 411-418.

Full Text: 2009\J Haz Mat169, 411.pdf

Abstract: The removal of clofibric acid from aqueous solution has been investigated in catalytic and non-catalytic semicontinuous ozonation runs. Kinetic data were analyzed using second order expressions for the reaction between organics and ozone or hydroxyl radicals. Catalytic runs used a commercial titanium dioxide catalyst consisting of fumed colloidal particles. The kinetic constant of the non-catalytic ozonation of clofibric acid at pH 3 was 8.16×10^-3±3.4×10^-4 L mmol^-1 s^-1. The extent of mineralization during non-catalytic runs ranged from 50% at pH 7 to 20% at pH 3 in a reaction that essentially took place during the first 10-20 min. The catalyst increased the total extent of mineralization, its effect being more important during the first part of the reaction. The pseudo-homogeneous catalytic rate constant was 2.17×10^-2 L mmol^-1 s^-1 at pH 3 and 6.80×10^-1 L mmol^-1 s^-1 at pH 5, with up to a threefold increase with respect to non-catalytic constants using catalyst load of 1 g/L. A set of stopped-flow experiments were designed to elucidate the role of catalyst. whose effect was probably due to the adsorption of organics on catalytic sites rather than to the promotion of ozone decomposition. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aqueous Solution, Catalyst, Catalytic, Catalytic Ozonation, Clofibric Acid, Data, Decomposition, Drinking-Water, Drugs, Environment, Experiments, First, Imperative Technologies, Kinetic, Load, Mineralization, North-Sea, Organics, Ozonation, Ozone, Particles, Personal Care Products, pH, Pharmaceutical Residues, Promotion, Rate Constant, Removal, Rights, Risk-Assessment, Role, Second Order, Second-Order, Sewage-Treatment Plants, Solution, Titanium, Titanium Dioxide, Waste-Water Treatment

? Cavaco, S.A., Fernandes, S., Augusto, C.M., Quina, M.J. and Gando-Ferreira, L.M. (2009), Evaluation of chelating ion-exchange resins for separating Cr(III) from industrial effluents. Journal of Hazardous Materials, 169 (1-3), 516-523.

Full Text: 2009\J Haz Mat169, 516.pdf

Abstract: In this study two chelating resins containing iminodiacetic acid groups (Amberlite IRC 748 and Diaion CR 11) and a chelating resin based on sulfonic and diphosphonic acid groups (Diphonix) were investigated in order to separate Cr(III) from industrial effluents produced in hard and decorative electroplating. Samples of two industrial plants were characterized during a period of about one year and a half in terms of the metals content (Cr, Cu, Na, Ca, Fe and Ni),Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Chemical Oxygen Demand (COD) and pH. Some of the physical properties of the resins, namely the moisture content, apparent density, intraparticle porosity and the particle size distribution were also evaluated. To quantify the sorption capacity of the resins, batch experiments were performed using synthetic solutions of Cr(III), as well as solutions of Fe in the case of Diphonix. The Langmuir and Langmuir-Freundlich isotherms enabled a good description of the ion-exchange equilibrium data, and the maximum sorption capacity determined for Amberlite and Diaion was 3.6 mequiv./g(dry resin). For Diphonix that parameter was 3.4 mequiv./g(dry resin). The Diphonix resin exhibits a high selectivity for transition metals (Fe, Ni) over the chromium trivalent. Therefore, it was screened as the most suitable for selectively removing those metal impurities from chromium electroplating effluents. For this resin, the sorption capacity is strongly dependent on the initial pH of the solution. Though, high regeneration efficiencies of Diphonix for stripping Cr(III) were found by using a mixture of NaOH/H₂O₂. The mathematical model tested for describing the dynamics of the process allowed a good fitting to the experimental data and enabled the estimation of effective pore diffusivity of Cr(III). The saturations of Diphonix with industrial effluents demonstrated that the breakthrough capacity of the resin is affected by the presence of other species in solution, such as Fe and Ni. Nevertheless, these effluents may be treated with this resin, being possible to separate Cr(Ill) from other transition metallic ions in solution. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aqueous-Solution, Breakthrough Curves, Capacity, Chromium, Cr(III), Cu, Diffusivity, Elsevier, Equilibrium, Evaluation, Groups, Ion Exchange, Ion Exchange Resins, Ion-Exchange Equilibrium, Isotherms, Kinetics, Mathematical Model, Metal, Metal-Ions, Metals, pH, Recovery, Regeneration, Removal, Solutions, Sorption, Species, Stripping, Waste Acid-Solution, Wastewater, Water

? Islam, M. and Patel, R. (2009), Nitrate sorption by thermally activated Mg, Al chloride hydrotalcite-like compound. Journal of Hazardous Materials, 169 (1-3), 524-531.

Full Text: 2009\J Haz Mat169, 524.pdf

Abstract: A laboratory study was conducted to investigate the ability of Mg-Al-Cl hydrotalcite-like compound for the removal of nitrate from synthetic nitrate solution. In the present study Mg-Al-Cl hydrotalcite was synthesized by co-precipitation method and was characterized using SEM, XRD, FTIR and TGA-DSC. To know the practical applicability, a detailed removal study of nitrate ion was carried out. The removal of nitrate was 87.6% under neutral condition, using 0.3 g of adsorbent in 100 mL of nitrate solution having initial concentration of 10 mg, L Adsorption kinetic study revealed that the adsorption process followed first-order kinetics. Adsorption data were fitted to linearly transformed Langmuir isotherm with R(2) (correlation coefficient)> 0.99. Thermodynamic parameters were also calculated to study the effect of temperature on the removal process. In order to understand the adsorption type, equilibrium data were tested with Dubinin-Radushkevich isotherm. The percentage removal was found to decrease gradually with increase in pH and the optimum pH was found to be 6. The process was rapid and equilibrium was established within first 40 min. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Isotherms, Adsorption Kinetic, Aqueous-Solution, Chloride, Co-Precipitation, Contaminated Groundwater, Coprecipitation, Denitrification, Denitrifying Submerged Filter, Equilibrium, First Order, FTIR, Hydrotalcite, Hydrotalcites, Ion-Exchange, Catalytic Process, Isotherm, Kinetic, Kinetics, Langmuir Isotherm, Nitrate, pH, Powder, Reduction, Removal, SEM, Sorption, Thermodynamic, Thermodynamic Parameter, Thermodynamic Parameters, Water, XRD, Zero-Valent Iron

? Kao, W.C., Wu, J.Y., Chang, C.C. and Chang, J.S. (2009), Cadmium biosorption by polyvinyl alcohol immobilized recombinant Escherichia coli. Journal of Hazardous Materials, 169 (1-3), 651-658.

Full Text: 2009\J Haz Mat169, 651.pdf

Abstract: Recombinant Escherichia coli expressing human metallothionein protein was immobilized with polyvinyl alcohol (PVA) for the removal of cadmium from solution. The adsorption ability was strongly affected by pH with optimal performance at pH 5.0, while it was less sensitive to temperature over the range of 20-42ºC. The adsorption kinetics and equilibrium of PVA-immobilized cells was best described by pseudo-second order model and Langmuir isotherm, respectively. Over the Cd concentrations range of 10-150 mg/l, PVA-cells had the highest Cd removal percentage (82.7%) at 10 mg Cd/l and a biomass loading of 15.4wt.%. Better adsorption ability was obtained when biomass loading was increased, as the highest adsorption capacity of 4.29 mg/g was achieved at 33.0 wt.% of biomass (initial Cd concentration = 100 mg/l). An aqueous solution of 0.01 M Na(3)NTA displayed the best desorption efficiency (57-89%) for four A/D cycles, while 51-61% of the original adsorption capacity was retained after regeneration. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Capacity, Adsorption Kinetics, Alcohol, Aqueous Solution, Aqueous-Solution, Biomass, Biosorption, Cadmium, Capacity, Cd, Cellulose, Chitin Beads, Chromium, Column, Concentration, Desorption, Efficiency, Equilibrium, Escherichia, Escherichia Coli, Fungal Biomass, Heavy Metal, Heavy-Metals, Human, Immobilization, Immobilized, Isotherm, Kinetics, Langmuir, Langmuir Isotherm, Lead(II), Loading, Metallothionein, Model, Olive Stone, Performance, pH, Polyvinyl Alcohol, Protein, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second Order Model, Pseudo-Second-Order, Regeneration, Removal, Rights, Solution, Temperature

? Korichi, S. and Bensmaili, A. (2009), Sorption of uranium(VI) on homoionic sodium smectite experimental study and surface complexation modeling. Journal of Hazardous Materials, 169 (1-3), 780-793.

Full Text: 2009\J Haz Mat169, 780.pdf

Keywords: Adsorption, Aluminum, Aqueous, Aqueous-Solution, Assessment, Clay, Complex, Complexation, Edge Site Surface, Elsevier, Heterogeneity, Humic-Acid, Modeling, Montmorillonite Clay, pH, Proton Adsorption, Purified Na-Smectite, Radionuclide Migration, Ray-Absorption Spectroscopy, Reactive Transport, Retardation, Sodium, Solid-Solution Interface, Sorption, Speciation, Species, Specific Surface Area, Subsurface Media, Surface Area, Surface Complexation Modeling, Titration Curves, Transport, Uranium, Uranyl-Ion

? Wang, J.N., Li, A.M., Xu, L. and Zhou, Y. (2009), Adsorption of tannic and gallic acids on a new polymeric adsorbent and the effect of Cu(II) on their removal. Journal of Hazardous Materials, 169 (1-3), 794-800.

Full Text: 2009\J Haz Mat169, 794.pdf

Abstract: In this paper, a new polymeric adsorbent WJN-09 for adsorbing and removing tannic and gallic acids from water was prepared, and its adsorption capacities for these two natural organic acids were tested by using the commercial resins XAD-7, XAD-4 and NDA-7 as references. The adsorption capacities of WJN-09 for tannic and gallic acids were higher than those of XAD-4, XAD-7 and NDA-7 at 303 K, which may be attributed to its amino function groups, pore structure and Zeta potential. The adsorption enthalpy changes Delta H exhibited that the adsorption of tannic acid by WJN-09 was a chemical and endothermic process. Furthermore, batch kinetic studies indicated that the tannic acid adsorbed to WJN-09 could be fitted well by both pseudo-first-order and pseudo-second-order adsorption equations, but the intra-particle diffusion played a dominant role in the adsorption of gallic acid. Changes of resin’s Zeta potential and acids’ average molecular size were observed when Cu(II) was added in solutions, which could explain the significant increase in WIN-09’s adsorption capacity for tannic and gallic acids in the presence of Cu(II). (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Capacities, Adsorption Capacity, Adsorption Enthalpy, Aqueous-Solutions, Batch, Capacity, Changes, Chemical, Chitosan, Cu(II), Diffusion, Dissolved Organic-Matter, Dye Adsorption, Endothermic, Enthalpy, Function, Gallic Acid, Humic Substances, Intra-Particle Diffusion, Intraparticle Diffusion, Isotherms, Kinetic, Kinetic Studies, Kinetics, Metal-Ions, Natural, Organic, Polymeric, Polymeric Adsorbent, Potential, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, References, Removal, Resins, Rights, Role, Size, Solutions, Structure, Tannic Acid, Water, XAD-4

? Zonoz, F.M., Ahmadi, S.J., Nosrati, S.A. and Maragheh, M.G. (2009), Preparation and characterization of zirconium(IV) molybdo tungsto vanado silicate as a novel inorganic ion exchanger in sorption of radionuclides. Journal of Hazardous Materials, 169 (1-3), 808-812.

Full Text: 2009\J Haz Mat169, 808.pdf

Abstract: A new mixed metal heteropoly anion-based cation exchanger Zr(IV) molybdo, tungsto vanado silicate (ZMTVS) was prepared under varying conditions. The material was characterized by FTIR, X-ray diffraction, TGA-DTA and SEM techniques. Its ion exchange capacity (IEC) for K⁺ was found to be 0.86 meq g^-1. Distribution coefficients (K-d) values for 10 metal ions and three radioisotopes were determined. On the basis of Kd values, two important and analytically difficult quantitative binary separations viz. Ni(II)-Co(II) and Ni(II)-Pb(II) were achieved on its column. Decontamination of aqueous nuclear waste solution was also studied. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Aqueous, Capacity, Cation-Exchanger, Distribution Coefficient, Elsevier, FTIR, Inorganic Ion Exchanger, Ion Exchange, Metal, Metal Ions, Nuclear Waste, SEM, Separation, Sorption, Zirconium Molybdo Tungsto Vanado Silicate

? Wu, P.X., Wu, W.M., Li, S.Z., Xing, N., Zhu, N.W., Li, P., Wu, J.H., Yang, C. and Dang, Z. (2009), Removal of Cd²⁺ from aqueous solution by adsorption using Fe-montmorillonite. Journal of Hazardous Materials, 169 (1-3), 824-830.

Full Text: 2009\J Haz Mat169, 824.pdf

Abstract: Fe-montmorillonite (Fe-Mont.) is obtained by exchanging the original interlayer cations of montmorillonite by poly-hydroxyl ferric. In this paper, Fe-Mont. was synthesized by using Ca-montmorillonite (Ca-Mont.) directly under ultrasonic treatment with the aim to enhance the ability of removal of heavy metal ions from wastewater. The modified materials were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR). Batch equilibrium experiments of Cd(II) ions (Cd²⁺) adsorption on the Fe-Mont. were performed. Effects of the initial pH of the solution and contact time on the adsorption of Cd²⁺ were studied. Four types of adsorption isotherms were applied to describe the adsorption isotherms of Cd²⁺ by Fe-Mont. The relationship between adsorbing capacity (q_e) and equilibrium mass concentration (C-e) is in accordance with the isothermal adsorption equation of Langmuir. Three kinetic models, including pseudo-first-order, pseudo-second-order and the Elovich equation model, were used to analyze the Cd²⁺ adsorption process. The pseudo-second-order chemical reaction kinetics provide the best correlation of the experimental data, therefore the adsorption dynamics follows the laws of pseudo-second-order kinetics. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Acid, Adsorption, Adsorption Dynamics, Adsorption Isotherm, Adsorption Isotherms, Aqueous Solution, Cadmium, Cadmium Ions, Capacity, Cd(II), Cd(II) Ions, Cd²⁺, Chemical, Clay, Concentration, Copper, Correlation, Data, Dynamics, Elovich, Elovich Equation, Equilibrium, Experimental, Experiments, Fe-Montmorillonite, FT-IR, FTIR, Heavy Metal, Heavy Metal Ions, Heavy-Metals, Ions, Isothermal, Isothermal Adsorption, Isotherms, Kaolinite, Kinetic, Kinetic Models, Kinetics, Langmuir, Laws, Metal, Metal Ions, Model, Models, Modified, Montmorillonite, pH, Pillared Montmorillonite, Pseudo First Order, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetics, Reaction Kinetics, Removal, Rights, Solution, Treatment, Ultrasonic, Waste, Wastewater, Water-Treatment, X-Ray, X-Ray Diffraction, XRD

? Belhalfaoui, B., Aziz, A., Elandaloussi, E., Ouali, M.S. and De Ménorval, L.C. (2009), Succinate-bonded cellulose: A regenerable and powerful sorbent for cadmium-removal from spiked high-hardness groundwater. Journal of Hazardous Materials, 169 (1-3), 831-837.

Full Text: 2009\J Haz Mat169, 831.pdf

Abstract: The primary objective of this work was to evaluate a chemically modified cellulose for the sorption efficiency and selectivity to remove cadmium from spiked high-hardness groundwater. Heterogeneous esterification of cellulose with succinic anhydride in toluene under basic conditions has proceeded very efficiently to yield the succinylated cellulose (SC) with fairly high DS value, as confirmed by FTIR and solid-state MAS C-13 NMR spectroscopies. Deprotonation of the free carboxylic acid group was achieved by alkaline treatment of SC with saturated NaHCO₃ aqueous solution. Batch experiments were carried out on the resulting sodic material (NaSC) to examine its cadmium-removing capability in both distilled water (DW) and spiked groundwater (GW). The results obtained from the sorption characteristics (kinetics, isotherms and pH effect) have revealed that NaSC material is particularly effective in removing cadmium from both DW and GW solutions, with a maximum uptake of 185.2 and 178.6 mg g^-1, respectively. These comparable sorption capacities strongly suggest that NaSC sorbent is highly selective to heavy metal over alkaline earth cations (Ca²⁺ and Mg²⁺) and therefore less susceptible to interference from background ions, naturally present in groundwater. On the other hand, cadmium sorption is shown to decrease with a decrease in pH which is indubitably inherent to the competing proton during the ion-exchange process. Furthermore, the material has proven to be efficiently regenerable by using a NaCl brine solution. Thus, the use of the sorbent sequentially to the first regeneration led to nearly no attenuation in the material’s capacity for cadmium-removal. Finally, the sorption effectiveness of NaSC is compared to those of other low-cost sorbents so far reported in the literature. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Anhydride, Aqueous Solution, Aqueous-Solutions, Brine, C-13, Cadmium, Capacity, Carboxylic, Cd(II), Cellulose, Characteristics, Effectiveness, Efficiency, Esterification, Experiments, First, FTIR, Groundwater, Heavy Metal, Heavy-Metal Ions, Ion Exchange, Ion-Exchange, Ionexchange, Ions, Isotherms, Kinetics, Literature, Low Cost, Mas, Metal, Modified, NaCl, NMR, pH, pH Effect, Polyethyleneimine, Primary, Regeneration, Rights, Selectivity, Solution, Solutions, Sorbent, Sorbents, Sorption, Sorption, Sugarcane Bagasse Cellulose, Toluene, Treatment, Uptake, Value, Water, Work

? Shi, T.H., Jia, S.G., Chen, Y., Wen, Y.H., Du, C.M., Guo, H.L. and Wang, Z.C. (2009), Adsorption of Pb(II), Cr(III), Cu(II), Cd(II) and Ni(II) onto a vanadium mine tailing from aqueous solution. Journal of Hazardous Materials,