Personal Research Database



Yüklə 2,92 Mb.
səhifə199/252
tarix15.08.2018
ölçüsü2,92 Mb.
#62455
1   ...   195   196   197   198   199   200   201   202   ...   252
175 (1-3), 393-398.

Full Text: 2010\J Haz Mat175, 393.pdf

Abstract: Adsorption of uranium(VI) on a natural clinoptilolite zeolite from Sweetwater County, Wyoming was investigated. Batch experiments were conducted to study the effects of pH and initial feed concentrations on uranium removal efficiency. It was found that the clinoptilolite can neutralize both acidic and low basic water solutions through its alkalinity and ion-exchange reactions with U within the solution. and adsorption of uranium(VI) species on clinoptilolite not only depends on the pH but also the initial feed concentration. The highest uranium removal efficiency (95.6%) was obtained at initial uranium concentration of 5 mg/L and pH 6.0. The Langmuir adsorption isotherm model correlates well with the uranium adsorption equilibrium data for the concentration range of 0.1-500 mg/L. From the experimental data obtained in this work, it was found that the zeolite sample investigated in this work is a mixture of clinoptilolite-Na zeolite and mineral impurities with a relatively large specific surface area (BET of 18 m(2)/g) and promising adsorption properties for uranium removal from contaminated water. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption, Adsorption Isotherm, Amphoteric, Batch Experiments, Carbon, Clinoptilolite, Equilibrium, Fluoride, Ion Exchange, Isotherm, Langmuir, Langmuir Adsorption Isotherm, Mechanism, pH, Removal, Sorption, Surface, Thermodynamic Behavior, Uranium, Water, Zeolite

? Pereira, A.S., Ferreira, G., Caetano, L., Martines, M.A.U., Padilha, P.M., Santos, A. and Castro, G.R. (2010), Preconcentration and determination of Cu(II) in a fresh water sample using modified silica gel as a solid-phase extraction adsorbent. Journal of Hazardous Materials, 175 (1-3), 399-403.

Full Text: 2010\J Haz Mat175, 399.pdf

Abstract: A method was developed to attach 4-amino-2-mercaptopyrimidine (AMP) onto silica gel surface and to determine trace metals. The Surface functionalization reaction was performed with a silylant agent, chloropropyltrimethoxysilane (Si-CPTS), and the product, Si-AMP, was characterized by FT-IR and elemental analysis to evaluate the Surface modification. The functionalized silica was applied in the sorption of Cu(II) ions from an aqueous medium. The series of adsorption isotherms were adjusted to a modified Langmuir equation and the maximum number of moles of adsorbed copper was 0.447 mmol g(-1). The modified material was placed in a preconcentration system, where it reached ail approximately 20-fold enrichment factor using 5 mg of Si-AMP. The proposed method was applied in the preconcentration and determination of Cu(II) in a fresh water sample from the Parana river and was validated through a comparative analysis of a standard reference material (1643 e). (C) 2009 Elsevier B.V. All rights reserved.

Keywords: 2-Aminothiazole, Activated Carbon, Adsorption, Adsorption Isotherms, Analysis, Aqueous Medium, Atomic-Absorption-Spectrometry, Copper, Copper, Cu(II), FTIR, Heavy-Metal Ions, ICP-OES, Isotherms, Langmuir, Mesoporous Silica, Modified Silica, Ni(II), Online Preconcentration, Preconcentration, Silica, Sorption, Surface Modification, System, Water

? Zhang, Y., Li, Q., Sun, L., Tang, R. and Zhai, J.P. (2010), High efficient removal of mercury from aqueous solution by polyaniline/humic acid nanocomposite. Journal of Hazardous Materials, 175 (1-3), 404-409.

Full Text: 2010\J Haz Mat175, 404.pdf

Abstract: A composite sorbent PANI/HA was prepared by adding humic acid (HA) into chemical oxidation process of polyaniline (PANI). The sorbent was characterized by BET analysis, transmission electron microscopy, and FT-IR spectra. Batch adsorption results showed that the sorbent had high affinity to Hg(II) in aqueous solutions. The adsorption kinetics results of Hg(II) showed that the adsorption reached equilibrium within 200 min and adsorption rates could be described by pseudo-second-order kinetics. Sorption of Hg(II) to PANI/HA agreed well to the Langmuir adsorption model at different ionic strengths with the maximum adsorption capacity of 671 mg g-1 (I = 0.20 M). The experimental results showed solution pH values had a major impact on Hg(II) adsorption and with the help of HA the sorbent can effectively remove Hg(II) in a wide pH range (pH 4-7.5). An adsorption mechanism was proposed based on the XPS results. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption, Adsorption Capacity, Adsorption Kinetics, Adsorption Mechanism, Analysis, Aqueous Solution, Aqueous Solutions, Batch Adsorption, BET, Capacity, Chemical, Chemical Oxidation, Chitosan, Composite, Cr(VI), Electron Microscopy, Equilibrium, Experimental, FT-IR, FTIR, FTIR Spectra, Heavy-Metals, Hg(II), Humic Acid, Humic-Acid, Impact, Ion-Exchange, Kinetics, Langmuir, Mar, Mechanism, Mercury, Model, Nanocomposite, Nanoparticles, Oxidation, Pani, Pani, Ha Nanocomposite, pH, Polyaniline, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second-Order, Pseudo-Second-Order Kinetics, Range, Rates, Removal, Rights, Solution, Solutions, Sorbent, Sorption, Transmission, Waste-Water, XPS

? Lopes, C.B., Otero, M., Lin, Z., Silva, C.M., Pereira, E., Rocha, J. and Duarte, A.C. (2010), Effect of pH and temperature on Hg2+ water decontamination using ETS-4 titanosilicate. Journal of Hazardous Materials, 175 (1-3), 439-444.

Full Text: 2010\J Haz Mat175, 439.pdf

Abstract: Batch stirred tank experiments were carried out to study the effect of pH (range 2-10, at 294 K) and temperature (277, 294 and 313 K, at pH 5) on the uptake of Hg2+ ions by ETS-4 microporous titanosilicate. Changes in the p H have a significant effect on the ETS-4 uptake efficiency, the optima I range being 4-6. Due to competition effects, the chemical used to adjust the pH of the Hg2+ solution also influences the uptake efficiency. Thermodynamic parameters for the uptake of Hg2+ ions were calculated. For the temperature range Studied, the Hg2+ sorption increased with decreasing temperature. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Aqueous-Solution, ETS-4 Titanosilicate, Ions, Mercury(II) Removal, Mercury Removal, pH, Sorption, Temperature, Thermodynamic, Thermodynamic Parameters, Water

? Huang, C.C. and Su, Y.J. (2010), Removal of copper ions from wastewater by adsorption/electrosorption on modified activated carbon cloths. Journal of Hazardous Materials, 175 (1-3), 477-483.

Full Text: 2010\J Haz Mat175, 477.pdf

Abstract: Adsorption and electrosorption of copper ions (Cu2+) from wastewater were investigated with variously modified activated carbon fiber (ACF) cloth electrodes. Commercial polyacrylonitrile-based ACF cloths were modified by nitric acid or impregnated with chitosan solution. The surface characteristics of ACFs before and after modification were evaluated by nitrogen adsorption-desorption isotherms, zeta potential, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry. Adsorption and electrosorption capacities of Cu2+ on ACF cloths without and with a bias potential were measured. respectively, and the electrosorption isotherms were also investigated. The initial pH of the copper ion solution was adjusted to 4.0. Experimental results showed that electrosorption effectively increases adsorption capacity. The adsorption/electrosorption isotherms of Cu2+ oil ACF cloths were in good agreement with Langmuir and Freundlich equations. The equilibrium adsorption capacity at 0.3V was 0.389 mmol/g, which is two times higher than that at open circuit. The maximum electrosorption capacity of Cu2+ oil chitosan impregnated ACF cloths was 0.854 mmol/g, which is about 2.2 times higher than that on the pristine cloths. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: ACF, Activated Carbon, Activated Carbon Cloth, Adsorption, Adsorption Capacity, Aqueous-Solution, Chemistry, Chitosan, Copper, Cr(VI), Electrosorption, Electrosorption, Enhancement, Equilibrium, Fiber, Fibers, Fourier Transform Infrared, Freundlich, FTIR, Industrial Wastewater, Infrared, Isotherms, Langmuir, Metal-Ions, pH, Removal, Wastewater, X-Ray Photoelectron Spectroscopy, XPS, Zeta Potential

? Chaichanawong, J., Yamamoto, T. and Ohmori, T. (2010), Enhancement effect of carbon adsorbent on ozonation of aqueous phenol. Journal of Hazardous Materials, 175 (1-3), 673-679.

Full Text: 2010\J Haz Mat175, 673.pdf

Abstract: Removal of aqueous phenol was examined by the simultaneous use of ozone and porous carbon adsorbents possessing different porous Structures and surface properties. The removal efficiency of aqueous phenol was higher with the simultaneous use of ozone and carbon adsorbents than the use of ozone alone, due to the adsorptive-concentration effect of the adsorbents. The enhancement effect of macroporous carbon cryogel beads (CCB) oil the ozonation of aqueous phenol was confirmed to be greater than in microporous activated carbon beads. Introduction of acidic functional groups to CCB by liquid-phase oxidation significantly diminished the adsorptive-concentration effect of CCB, since the interaction of aqueous phenol with the surface of CCB decreased. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption, Beads, Biodegradation, Catalytic-Oxidation, Degradation, Desorption Characteristics, Liquid-Phase Oxidation, Oxidation, Ozonation, Ozone, Phenol, Porosity, Removal, Surface Chemistry, Surface-Properties, TOC, Waste-Water

? Srinivasan, A. and Viraraghavan, T. (2010), Oil removal from water by fungal biomass: A factorial design analysis. Journal of Hazardous Materials, 175 (1-3), 695-702.

Full Text: 2010\J Haz Mat175, 695.pdf

Abstract: A fractional factorial design analysis was conducted to screen the significant factors influencing removal of three emulsified oils from water, namely, standard mineral oil (SMO), canola oil (CO) and Bright-Edge 80 Cutting Oil using non-viable biomass of fungus Mucor rouxii rich with chitosan in its cell wall. Factors investigated were pH of the solution (3-9), temperature (5-30 degrees C), adsorbent dose (0.05-0.5 g), concentration of oil (50-350 mg/L) and rotational speed of the shaker (100-200 rpm). It was observed that pH of the solution was the most influencing parameter oil the removal of all the three oils studied. Higher oil removal efficiencies (80-99%) were obtained at a pH of 3.0 by M. rouxii biomass for all the three oils studied. Temperature had an effect oil SMO and Bright-Edge 80 removal while adsorbent dose was found to influence the removal of SMO. Average removals of SMO and Bright-Edge 80 were higher by 13% at a solution temperature of 30 degrees C compared to removals at 5 degrees C. Oil concentration had an effect on the removal of CO. The average removal of CO was found to be higher by approximately 15% at an initial oil concentration of 50 mg/L than at 350 mg/L (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption, Analysis, Biomass, Chitosan, CO, Factorial Design, Mucor Rouxii, Mucor-Rouxii, Oil Removal, pH, Removal, Temperature, Water

? He, Q., Hu, Z., Jiang, Y., Chang, X.J., Tu, Z.F. and Zhang, L.N. (2010), Preconcentration of Cu(II), Fe(III) and Pb(II) with 2-((2-aminoethylamino)methyl)phenol-functionalized activated carbon followed by ICP-OES determination. Journal of Hazardous Materials, 175 (1-3), 710-714.

Full Text: 2010\J Haz Mat175, 710.pdf

Abstract: A procedure for separation and preconcentration trace amount of Cu(II), Fe(III) and Pb(II) by 2-((2-aminoethylamino)methyl)phenol-functionalized activated carbon (AC-AMP) packed column has been proposed. Under the optimized conditions (pH 4, flow rate 2.0 mLmin(-1)), Cu(II), Fe(III) and Pb(II) were retained on the column, then quantitatively eluted by 2 mL 1 mol L-1 nitric acid solution and determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). The tolerance limits of electrolytes were very high. The adsorption capacity of AC-AMP was found to be 12.1. 67.1, and 16.2 mg g(-1) for Cu(II), Fe(III), and Pb(II), respectively. According to the definition of International Union of Pure and Applied Chemistry, the detection limits (3 sigma) of this method for Cu(II), Fe(III) and Pb(II) were 0.27, 0.41 and 0.16 mu g L-1, respectively. The relative standard deviation under optimum conditions is less than 3.0% (n = 11). The proposed method has been validated by analyzing a certified reference material and successfully applied to the preconcentration and determination of Cu(II), Fe(III), and Pb(II) in actual samples with satisfactory results. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: 2-((2-Aminoethylamino)Methyl)Phenol, Activated Carbon, Adsorption, Adsorption Capacity, Atomic-Absorption-Spectrometry, Chemistry, Copper, Coprecipitation, Cu(II), Enrichment, Heavy-Metal Ions, ICP-OES, Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), Lead, Liquid-Liquid Microextraction, Pb(II), pH, Preconcentration, Separation, Solid-Phase Extraction, Solid-Phase Extraction, Water Samples

? Zhao, G.H., Li, Y.F., Liu, X.X. and Liu, X.L. (2010), Preparation of capsules containing 1-nonanol for rapidly removing high concentration phenol from aqueous solution. Journal of Hazardous Materials, 175 (1-3), 715-725.

Full Text: 2010\J Haz Mat175, 715.pdf

Abstract: This study investigated the potential of capsules containing 1-nonanol for the adsorption of phenol at high initial concentrations. The polysulfone capsules containing 1-nonanol (PSF@1-nonanol capsules) were Successfully prepared with a phase inversion method, and the results showed that 1-nonanol was encapsulated with polysulfone as an encapsulation capacity of 67.99% was achieved. Systematic Studies on phenol adsorption equilibrium, kinetics and isotherms by PSF@1-nonanol capsules were carried out. The results showed that the rate of adsorption of phenol is initially quite rapid and equilibrium is reached in about 90 min. Phenol adsorption uptake was found to increase with increase in initial concentration and adsorption time, whereas adsorption of phenol was more favourable at acidic pH and low temperature. The adsorption kinetics of phenol followed pseudo-second-order model, and the best fits of adsorption isotherms were achieved with the Freundlich equation. These results demonstrate that the use of PSF@1-nonanol capsules enhanced the mass transfer rate and the uptakes to phenol at high initial concentrations. Furthermore, after seven times of repeated extraction and stripping, the microcapsules kept almost the same adsorption ability, which indicated that the PSF@1-nonanol capsules have very good stability in the adsorption process. Therefore, PSF@1-nonanol capsules can be taken as an ideal adsorbent for rapid removal of high concentration phenol from aqueous solution. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: 1-Nonanol, Activated Carbon, Adsorbent, Adsorption, Adsorption Equilibrium, Adsorption Isotherms, Adsorption Kinetics, Adsorptive Removal, Aqueous Solution, Bagasse Fly-Ash, Capacity, Capsule, Capsules, Concentration, Encapsulation, Equilibrium, Extraction, Freundlich, Freundlich Equation, Inversion, Ionic Liquid, Isotherms, Kinetics, Low Temperature, Mar, Mass Transfer, Model, pH, Phenol, Phenol Adsorption, Polystyrene Microcapsules, Polysulfone, Polysulfone Microcapsules, Potential, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Rare-Earth-Metals, Removal, Rights, Separation, Solution, Stability, Stripping, Temperature, Time, Uptake

? Rodríguez-Jordá, M.P., Garrido, F. and García-González, M.T. (2010), Potential use of gypsum and lime rich industrial by-products for induced reduction of Pb, Zn and Ni leachability in an acid soil. Journal of Hazardous Materials, 175 (1-3), 762-769.

Full Text: 2010\J Haz Mat175, 762.pdf

Abstract: This study evaluates the potential use of four industrial by-products (phosphogypsum (PG), Fed gypsum (RG), Sugar foam (SF), and ashes from biomass combustion (ACB)), applied at two rates in single and combined amendments to reduce the mobility and availability of Pb, Zn and Ni in a metal-spiked acid soil. Leaching experiments were done to estimate leachability indexes and assess their effectiveness. Most of the treatments significantly reduced the metal leachability although only a few were effective for all metals. Based on principal component and cluster analysis, sugar foam (SF) and a mixture of RG and ACB (RG+ACB), both applied at high rate, were selected as first choices to reduce mobility and availability of the three metals. Metal sorption mechanisms involved in the reduction of their leachability were identified using scanning electron microscopy. In the SF-treated samples, the metals were found associated to amorphous Al-hydroxy polymers deposited on phyllosilicates and organic matter particles. In the (RG+ACB)-treated samples, Pb, Zn, and traces of Ni were found associated to Fe/Ti oxide phases with a significant concentration Of S, Suggesting the formation of metal-sulfate ternary complexes. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Analysis, Biomass, Cd, Contaminated Soils, Cu, Feasibility, Heavy-Metals, In Situ Remediation, In-Situ Remediation, Industrial By-Products, Metal Availability, Metal Leachability, Mobility, Phosphogypsum, Polymers, Sewage-Sludge, Soil, Sorption, Toxic Elements

? Poch, J. and Villaescusa, I. (2010), A model to describe Cr(VI) kinetics biosorption. Journal of Hazardous Materials, 175 (1-3), 770-778.

Full Text: 2010\J Haz Mat175, 770.pdf

Abstract: in this work, the effect of pH control on kinetics of Cr(VI) sorption onto grape stalks has been studied. A set of experiments were performed at a constant pH 3 +/- 0.1 which was assured by means of a Programmable Logic Controller (PLC). In a second set of experiments the initial pH was adjusted to pH 3 and then pH was allowed to freely evolve during the sorption process. Both sets of experiments were carried out at different temperatures within the range 5-50 degrees C. Constant temperature was assured by water recirculation from a thermostatic bath. Results demonstrated that pH has high influence on kinetics only at the lowest temperatures studied. A model based on a complex reaction sequence which takes into account Cr(VI) sorption, reduction of Cr(VI) to Cr(III), sorption of the formed Cr(III) which includes the pH variation during the sorption process has been proposed to model Cr(VI) kinetics sorption onto grape stalk waste. Furthermore. the robustness of the model has been tested. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Bacteria, Batch Reactor, Biomaterials, Biosorption, Box Plots, Complex, Cr(III), Cr(VI), Cr(VI) Reduction, Effect of pH, Effect of Temperature, Grape Stalk, Hexavalent Chromium, Kinetics, Mechanism, pH, Reduction, Removal, Sorption, Waste, Water

? Reffas, A., Bernardet, V., David, B., Reinert, L., Lehocine, M.B., Dubois, M., Batisse, N. and Duclaux, L. (2010), Carbons prepared from coffee grounds by H3PO4 activation: Characterization and adsorption of methylene blue and Nylosan Red N-2RBL. Journal of Hazardous Materials, 175 (1-3), 779-788.

Full Text: 2010\J Haz Mat175, 779.pdf

Abstract: Activated carbons were prepared by the pyrolysis of coffee grounds impregnated by phosphoric acid at 450 degrees C for different impregnation ratios: 30, 60, 120 and 180 wt.%. Materials were characterized for their surface chemistry by elemental analysis, “Boehm titrations”, point of zero charge measurements, Infrared spectroscopy, thermogravimetric analysis (TGA); as well as for their porous and morphological structure by Scanning Electron Microscopy (SEM) and nitrogen adsorption at 77 K. The impregnation ratio was found to govern the porous structure of the prepared activated carbons. Low impregnation ratios (< 120 wt.%) led to essentially microporous and acidic activated carbons whereas high impregnation ratios (> 120 wt.%) yielded to essentially mesoporous carbons with Specific Surface areas as high as 925 m(2) g(-1), pore volume as large as 0.7 cm(3) g(-1), and neutral surface. The activated carbons prepared from coffee grounds were compared to a commercial activated carbon (S-BET similar to 1400 m(2) g(-1)) for their adsorption isotherms of methylene blue and “Nylosan Red N-2RBL”, a cationic and anionic (azo) dye respectively. The mesoporous structure of the material produced at 180 wt.% H3PO4 ratio was found to be appropriate for an efficient sorption of the latter azo dye. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Activated Carbons, Adsorption, Adsorption Isotherms, Analysis, Capacities, Carbonization, Characterization, Chemical Activation, Coffee Grounds, Dye, Dye Adsorption, H3PO4, H3PO4 Activated Carbons, Isotherms, Mesoporous, Methylene Blue, Peach Stones, Phosphoric-Acid, Pore, Pore-Size, Porosity, Porosity, Sem, Shell, Sites, Sorption, Surface Chemistry, ZnCl2

? Saxena, A., Srivastava, A.K., Singh, B., Gupta, A.K., Suryanarayana, M.V.S. and Pandey, P. (2010), Kinetics of adsorptive removal of DEClP and GB on impregnated Al2O3 nanoparticles. Journal of Hazardous Materials, 175 (1-3), 795-801.

Full Text: 2010\J Haz Mat175, 795.pdf

Abstract: Nanoparticles of AP-Al2O3 (aero-gel produced alumina) have been produced by an alkoxide based synthesis involving aluminum powder, methanol, toluene and water. Thus produced alumina nanoparticles were characterized and the data indicated the formation of nanoparticles of alumina in the size range of 2-30 nm with high surface area (375 m(2)/g). Thereafter, these nanoparticles were impregnated with reactive chemicals. Adsorptive removal kinetics for DEClP (diethylchlorophosphate) and GB (isopropy-Imethylphosphonofluoridate, sarin) was monitored by GC-FID (gas chromatograph coupled with flame ionization detector) technique and found to be following pseudo first order reaction kinetics. Among impregnated AP-Al2O3 nanoparticles based sorbent systems AP-Al2O3 impregnated with 9-molybdo-3-vanadophosphoric acid (10%, w/w) was found to be the most reactive with least half-life values of 7 and 30 min for the removal of DEClP and GB, respectively, whereas unimpregnated AP-Al2O3 nanoparticles showed the best adsorption potential among all studied systems. In addition to this, hydrolysis reaction (identified using GC/MS (gas chromatograph coupled with mass spectrometer) technique) was found to be the route of degradation of DEClP and GB on impregnated alumina nanoparticles. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Degradation, Diethylchlorophosphate (DECLP), Dmmp, Gamma-Al2O3, Impregnation, In-Situ Degradation, Kinetics, Metal Oxide Nanoparticles, Nanoparticles, Oxide, Reagents, Removal, Sarin, Sarin (GB, Isopropylmethylphosphonofluoridate), Simulants, Sorbent, Sorbents, Sorption Kinetics, Sulfur Mustard, Surface, Synthesis, Toluene, Water

? Wang, X.S., Chen, L.F., Li, F.Y., Chen, K.L., Wan, W.Y. and Tang, Y.J. (2010), Removal of Cr(VI) with wheat-residue derived black carbon: Reaction mechanism and adsorption performance. Journal of Hazardous Materials, 175 (1-3), 816-822.

Full Text: 2010\J Haz Mat175, 816.pdf

Abstract: The removal of Cr(VI) from aqueous solutions using black carbon (BC) isolated from the burning residues of wheat straw was investigated as a function of pH, contact time, reaction temperature, supporting electrolyte concentration and analytical initial Cr(VI) concentration in batch studies. The effect of surface properties on the adsorption behavior of Cr(VI) was investigated with scanning electron microscope (SEM) equipped with the energy dispersive X-ray spectroscope (EDS) and Fourier transform-infrared (FTIR) spectroscopy. The removal mechanism of Cr(VI) onto the BC was investigated and the result showed that the adsorption reaction consumed a large amount of protons along the reduction of Cr(VI) to Cr(III). The oxidation of the BC took place concurrently to the chromium reduction and led to the formation of hydroxyl and carboxyl functions. An initial solution pH of 1.0 was most favorable for Cr(VI) removal. The adsorption process followed the pseudo-second order equation and Freundlich isotherm very well. The Cr(VI) adsorption was temperature-dependent and almost independent on the sodium chloride concentrations. The maximum adsorption capacity for Cr(VI) was found at 21.34mg/g in an acidic medium, which is comparable to other low-cost adsorbents. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbents, Adsorption, Adsorption Behavior, Adsorption Capacity, Adsorption Performance, Aqueous Solutions, Aqueous-Solution, Batch, Batch Studies, Behavior, Biosorption, Black Carbon, Capacity, Carbon, Chloride, Chromium, Concentration, Cr(VI), Cr(VI), Eds, Energy, Equilibrium, Freundlich, Freundlich Isotherm, FTIR, Function, Functions, Hexavalent Chromium, Isotherm, Kinetics, Low Cost, Low Cost Adsorbents, Low-Cost Adsorbents, Mar, Mechanism, Oxidation, Performance, pH, Phenanthrene, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second-Order, Reaction, Reduction, Reduction, Removal, Residues, Rights, SEM, Sodium, Sodium Chloride, Solution, Solutions, Sorption, Spectroscopy, Straw, Surface, Surface Properties, Temperature, Time, X-Ray

? Kim, S.C., Davis, J.G., Truman, C.C., Ascough, J.C. and Carlson, K. (2010), Simulated rainfall study for transport of veterinary antibiotics - mass balance analysis. Journal of Hazardous Materials,


Yüklə 2,92 Mb.

Dostları ilə paylaş:
1   ...   195   196   197   198   199   200   201   202   ...   252




Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©genderi.org 2024
rəhbərliyinə müraciət

    Ana səhifə