Personal Research Database

Full Text: 2009\J Env Sci-Chi21, 1473.pdf

Abstract: A novel adsorbent (AMPS-silica) was synthesized by bounding AMPS (2-acrylamido-2-methylpropanesulfonic acid) onto silica surface, which functioned with gamma-methacryloxypropyltrimethoxysilane reagent. The adsorbent was characterized by nitrogen adsorption/desorption measurement, thermogravimetric analysis (TGA) and potentiometric titration analysis. The TGA result indicated that the surface modification reactions introduced some organic functional groups onto the surface of silica. The surface area of AMPS-silica was 389.7 m²/g. The adsorbent was examined for copper ion removal in series of batch adsorption experiments. Results showed that the adsorption of Cu²⁺ onto AMPS-silica was pH dependent, and the adsorption capacity increased with increasing pH from 2 to 6. The adsorption kinetics showed that Cu²⁺ adsorption was fast and the data fitted well with a pseudo second-order kinetic model. The adsorption of Cu²⁺ onto AMPS-silica obeyed both Freundlich and Langmuir isotherms, with r² = 0.993 and r² = 0.984, respectively. The maximum Cu²⁺ adsorption capacity was 19.9 mg/g. The involved mechanism might be the adsorption through metal binding with organic functional groups such as carboxyl, amino and sulfonic groups. Cu²⁺ loaded on AMPS-silica could be desorbed in HNO₃ solution, and the adsorption properties remain stable after three adsorption-desorption cycles.

Keywords: 2-Acrylamido-2-Methylpropanesulfonic Acid (AMPS), Adsorbent, Adsorption, Adsorption Capacity, Adsorption Kinetics, Adsorption Properties, Adsorption-Desorption, Adsorption, Desorption, Analysis, Aqueous-Solutions, Batch, Batch Adsorption, Binding, Capacity, Copper, Copper Ion, Cu²⁺, Data, Equilibrium, Experiments, Freundlich, Functional Groups, Gamma-Methacryloxypropyltrimethoxysilane, Gel, Heavy-Metal Ions, Isotherms, Kinetic, Kinetic Model, Kinetics, Langmuir, Langmuir Isotherms, Lead, Measurement, Mechanism, Mechanisms, Mercury, Mesoporous Silica, Metal, Model, Modification, Nitrogen, Organic, Organically Functionalized Silica Gel, Parameters, pH, pH-Dependent, Potentiometric Titration, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Removal, Second Order, Second-Order, Selective Removal, Silica, Silica Gel, Solution, Surface, Surface Area, Surface Modification, TGA, Waste-Water

? Li, C.X., Gao, J., Pan, J.M., Zhang, Z.L. and Yan, Y.S. (2009), Synthesis, characterization, and adsorption performance of Pb(II)-imprinted polymer in nano-TiO₂ matrix. Journal of Environmental Sciences-China, 21 (12), 1722-1729.

Full Text: 2009\J Env Sci-Chi21, 1722.pdf

Abstract: Surface ion-imprinted in combination with sol-gel process was applied to synthesis a new Pb(II)-imprinted polymer for selective separation and enrichment of trace Pb(II) from aqueous solution. The prepared material was characterized by using the infrared spectra, X-ray diffractometer, and scanning electron microscopy. The batch experiments were conducted to study the optimal adsorption condition of adsorption trace Pb(H) from aqueous solutions on Pb(II)-imprinted polymer. The equilibrium was achieved in approximately 4.0 h, and the experimental kinetic data were fitted the pseudo second-order model better. The maximum adsorption capacity was 22.7 mg/g, and the Langmuir equation fitted the adsorption isotherm data. The results of selectivity experiment showed that selectively adsorbed rate of Pb(II) on Pb(II)-imprinted polymer was higher than all other studied ions. Desorption conditions of the adsorbed Pb(II) from the Pb(H)-imprinted polymer were also studied in batch experiments. The prepared Pb(H)-imprinted polymer was shown to be promising for the separation and enrichment of trace Pb(II) from water samples. The adsorption and desorption mechanisms were proposed.

Keywords: Adsorption, Adsorption Capacity, Adsorption Isotherm, Adsorption Performance, Aqueous Solution, Aqueous Solutions, Batch, Batch Experiments, Capacity, Characterization, Chitosan, Complexation, Data, Desorption, Electron Microscopy, Enrichment, Equilibrium, Experiment, Experimental, Experiments, Ion-Imprinted, Ions, Isotherm, Kinetic, Langmuir, Langmuir Equation, Matrix, Mechanisms, Metal, Model, Nano-TiO₂, Pb(II), Pb(II), Performance, Polymer, Preconcentration, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Removal, Scanning Electron Microscopy, Second Order, Second-Order, Second-Order Model, Selective, Selective Separation, Selectivity, Separation, Sol-Gel, Sol-Gel Process, Solid-Phase Extraction, Solution, Solutions, Sorption, Synthesis, Water, Water Samples, X-Ray

? Wang, Y.S., Zeng, L., Ren, X.F., Song, H. and Wang, A.Q. (2010), Removal of Methyl Violet from aqueous solutions using poly (acrylic acid-co-acrylamide)/attapulgite composite. Journal of Environmental Sciences-China, 22 (1), 7-14.

Full Text: J Env Sci-Chi22, 7.pdf

Abstract: The adsorption of Methyl Violet (MV) cationic dye from aqueous solution was carried out by using crosslinked poly (acrylic acid-co-acrylamide)/attapulgite (Poly(AA-co-AM)/ATP) composite as adsorbent. The factors influencing adsorption capacity of the composite such as pH, concentration of the dye, temperature, contact time, adsorbent dosage, ionic strength and surfactant were systematically investigated. The equilibrium data fitted very well to the Langmuir isotherm and the maximum adsorption capacity reached 1194 mg/g at 30ºC. The thermodynamic parameters including ΔG°, ΔH° and ΔS° for the adsorption processes of MV on the composite were also calculated, and the negative ΔH° and ΔG° confirmed that the adsorption process was exothermic and spontaneous. The kinetic studies showed that the adsorption process was consistent with the pseudo second-order kinetic model and the desorption studies revealed that the regeneration of the composite adsorbent can be easily achieved.

Keywords: Acid, Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Capacity, Adsorption Kinetics, Aqueous Solution, Aqueous Solutions, Basic-Dyes, Blue, Capacity, Cationic Dye, Composite, Concentration, Data, Desorption, Desorption Studies, Dye, Equilibrium, Exothermic, Hydrogels, Ionic Strength, Iron Humate, Isotherm, Kinetic, Kinetic Model, Kinetic Studies, Langmuir, Langmuir Isotherm, Methyl Violet, Model, pH, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Regeneration, Removal, Second Order, Second-Order, Solution, Solutions, Sorption, Strength, Superabsorbent Composite, Surfactant, Temperature, Thermodynamic, Thermodynamic Parameters, Water

? Kamal, M.H.M.A., Azira, W.M.K.W., Kasmawati, M., Haslizaidi, Z. and Saime, W.N.W. (2010), Sequestration of toxic Pb(II) ions by chemically treated rubber (Hevea brasiliensis) leaf powder. Journal of Environmental Sciences-China, 22 (2), 248-256.

Abstract: Rubber leaf powder (an agricultural waste) was treated with potassium permanganate followed by sodium carbonate and its performance in the removal of Pb(II) ions from aqueous solution was evaluated. The interactions between Pb(II) ions and functional groups on the adsorbent surface were confirmed by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDX). The effects of several important parameters which can affect adsorption capacity such as pH, adsorbent dosage, initial lead concentration and contact time were studied. The optimum pH range for lead adsorption was 4-5. Even at very low adsorbent dosage of 0.02 g, almost 100% of Pb(H) ions (23 mg/L) could be removed. The adsorption capacity was also dependent on lead concentration and contact time, and relatively a short period of time (60-90 min) was required to reach equilibrium. The equilibrium data were analyzed with Langmuir, Freundlich and Dubinin-Radushkevich isotherms. Based on Langmuir model, the maximum adsorption capacity of lead was 95.3 mg/g. Three kinetic models including pseudo first-order, pseudo second-order and Boyd were used to analyze the lead adsorption process, and the results showed that the pseudo second-order fitted well with correlation coefficients greater than 0.99.

Keywords: Activated Carbon, Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Capacity, Agricultural, Agricultural Waste, Aqueous Solution, Aqueous-Solutions, Capacity, Carbonate, Coconut Shell, Concentration, Copper Ions, Correlation, Cu(II) Ions, Cystoseira-Indica, Data, Divalent Metal-Ions, EDX, Electron Microscopy, Energy, Equilibrium, First Order, Freundlich, FT-IR, FTIR, Functional Groups, Heavy-Metals, Ions, Isotherm, Isotherms, Kinetic, Kinetic Models, Kinetics, Langmuir, Langmuir Model, Lead, Low-Cost, Model, Models, Modified Seaweed, Pb(II), Pb(II) Ions, Performance, Permanganate, pH, Potassium, Pseudo First Order, Pseudo First-Order, Pseudo Second Order, Pseudo Second-Order, Pseudo-First-Order, Pseudo-Second-Order, Range, Removal, Rubber Leaf Powder, Scanning Electron Microscopy, Second Order, Second-Order, SEM, Sodium, Solution, Spectroscopy, Surface, Time, Toxic, Waste, X-Ray

? Ngah, W.S.W. and Fatinathan, S. (2010), Pb(II) biosorption using chitosan and chitosan derivatives beads: Equilibrium, ion exchange and mechanism studies. Journal of Environmental Sciences-China, 22 (3), 338-346.

Full Text: 2010\J Env Sci-Chi22, 338.pdf

Abstract: The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initial pH, adsorbent dosage and different initial concentration of Pb(II) ions were evaluated. The mechanism involved during the adsorption process was explored based on ion exchange study and using spectroscopic techniques. The adsorption capacities obtained based on non-linear Langmuir isotherm for chitosan, chitosan-GLA and chitosan-alginate beads in single metal system were 34.98, 14.24 and 60.27 mg/g, respectively. However, the adsorption capacity of Pb(II) ions were reduced in the binary metal system due to the competitive adsorption between Pb(II) and Cu(II) ions. Based on the ion exchange study, the release of Ca²⁺ Mg²⁺, K⁺ and Na⁺ ions played an important role in the adsorption of Pb(II) ions by all three adsorbents but only at lower concentrations of Pb(II) ions. Infrared spectra showed that the binding between Pb(II) ions and the adsorbents involved mostly the nitrogen and oxygen atoms. All three adsorbents showed satisfactory adsorption capacities and can be considered as an efficient adsorbent for the removal of Pb(II) ions from aqueous solutions.

Keywords: Adsorbent, Adsorbent Dosage, Adsorbents, Adsorption, Adsorption Capacities, Adsorption Capacity, Alginate, Aqueous Solution, Aqueous Solutions, Aqueous-Solutions, Beads, Binding, Biosorption, Capacity, Chitosan, Chitosan And Chitosan Derivatives Beads, Chitosan Derivatives, Competitive, Competitive Adsorption, Concentration, Cross-Linking, Cu(II), Cu(II) Ions, Equilibrium, GLA Beads, Heavy-Metal Ions, Hydrogel Beads, Ion Exchange, Ion-Exchange, Ions, Isotherm, Langmuir, Langmuir Isotherm, Lead Ions, Mechanism, Metal, Na⁺, Nitrogen, Oxygen, Pb(II), Pb(II) Ions, pH, Release, Removal, Role, Solution, Solutions, Techniques, Waste-Water

? He, X.J., Yao, L., Liang, Z. and Ni, J.R. (2010), Paper sludge as a feasible soil amendment for the immobilization of Pb²⁺. Journal of Environmental Sciences-China, 22 (3), 413-420.

Full Text: 2010\J Env Sci-Chi22, 413.pdf

Abstract: The possibility of amending Pb²⁺ contaminated soil (S) with paper sludge (P) was investigated through adsorption and desorption experiments. The adsorption process of Pb²⁺ in soil containing paper sludge (SP) could be well described by pseudo second-order kinetic model and the Langmuir isotherm model. After P addition, the equilibrium time decreased greatly (from 28 to 8 hr) and the Pb²⁺ maximum adsorbed amount (Q_max) increased by a factor of more than three to 102.04 mg/g. Q_max reached its maximum as S:P was 9:1 (m/m) after 10 days contact between S and P. Moreover, Pb²⁺ adsorbed amount increased with the rise of pH during the adsorption process. Desorption experiments indicated that Pb²⁺ adsorption in SP was irreversible. The metal ion fraction was analyzed with Energy Dispersive Spectrometer and Environmental Scan Electron Microscope. As a result, the addition of P to soil was found to induce a decrease in the mobile forms. The Pb²⁺ complexes formation in the presence of carbonates was the main adsorption mechanism. Overall, the paper sludge could be one of the promising soil amendments for the remediation of soil with Pb²⁺ contamination.

Keywords: Adsorption, Adsorption, Adsorption Mechanism, Cadmium, Contamination, Desorption, Equilibrium, Experiments, Forms, Heavy-Metal, Immobilization, Isotherm, Isotherm Model, Kinetic, Kinetic Model, Langmuir, Langmuir Isotherm, Langmuir Isotherm Model, Lead, Mechanism, Metal, Metal Ion, Mill Sludge, Mobile, Model, Montmorillonite, Organic-Matter, P, Paper Sludge, Pb²⁺, Pb²⁺ Adsorption, pH, Phytoremediation, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Remediation, Removal, Second Order, Second-Order, Sludge, Soil, Soil Amendment, Sorption, Time

? Ferrero, F. (2010), Adsorption of Methylene Blue on magnesium silicate: Kinetics, equilibria and comparison with other adsorbents. Journal of Environmental Sciences-China, 22 (3), 467-473.

Full Text: 2010\J Env Sci-Chi22, 467.pdf

Abstract: Batch adsorption from aqueous solutions in a slightly basic medium of Methylene Blue, up to 2500 mg/L, onto synthetic magnesium silicate (Florisil) of three particle size ranges (mean diameters of 112, 200 and 425 mu m) was compared to the corresponding adsorption onto activated carbon and Amberlite XAD-2. The best fit of the kinetic results was achieved by a pseudo second-order equation. The equilibrium data were found to be well represented by the Langmuir isotherm equation. Amberlite XAD-2, an unspecific adsorbent capable of adsorbing exclusively through a surface effect, exhibited a poor dye uptake, confirming that the adsorption mechanism on Florisil was due to electrostatic attraction and ion exchange. Moreover, the comparison between Florisil and the other adsorbents was performed on the basis of the evaluation of the surface area and pore volume occupied by the adsorbed dye.

Keywords: Activated Carbon, Adsorbent, Adsorbents, Adsorption, Adsorption Isotherms, Adsorption Kinetics, Adsorption Mechanism, Aqueous Solutions, Aqueous-Solution, Batch Adsorption, Carbon, Clay, Color Removal, Comparison, Data, Dye, Dye Adsorption, Dye Removal, Earth, Effluents, Equilibria, Equilibrium, Evaluation, Florisil, Ion Exchange, Ion-Exchange, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Isotherm, Low-Cost Adsorbents, Magnesium, Magnesium Silicate, Mass-Transfer Processes, Mechanism, Methylene Blue, Particle Size, Pore Volume, Pseudo Second Order, Pseudo Second-Order, Pseudo Second-Order Equation, Pseudo-Second-Order, Second Order, Second-Order, Second-Order Equation, Silicate, Size, Solutions, Surface, Surface Area, Uptake, Volume

? Liu, Y., Zheng, Y.A. and Wang, A.Q. (2010), Enhanced adsorption of Methylene Blue from aqueous solution by chitosan-g-poly (acrylic acid)/vermiculite hydrogel composites. Journal of Environmental Sciences-China, 22 (4), 486-493.

Full Text: 2010\J Env Sci-Chi22, 486.pdf

Abstract: A series of chitosan-g-poly (acrylic acid)/vermiculite hydrogel composites were synthesized and used as adsorbents for the investigation of the effect of process parameters such as vermiculite content, pH of dye solution, contact time, initial concentration of dye solution, temperature, ionic strength and concentration of surfactant sodium dodecyl sulfate on the removal of Methylene Blue (MB) from aqueous solution. The results showed that the adsorption capacity for dye increased with increasing pH, contact time and initial dye concentration, but decreased with increasing temperature, ionic strength and sodium dodecyl sulfate concentration in the present of the surfactant. The adsorption kinetics of MB onto the hydrogel composite followed pseudo second-order kinetics and the adsorption equilibrium data obeyed Langmuir isotherm. By introducing 10 wt.% vermiculite into chitosan-g-poly (acrylic acid) polymeric network, the obtaining hydrogel composite showed the highest adsorption capacity for MB, and then could be regarded as a potential adsorbent for cationic dye removal in a wastewater treatment process.

Keywords: Activated Carbon, Adsorbent, Adsorbents, Adsorption, Adsorption Capacity, Adsorption Equilibrium, Adsorption Isotherms, Adsorption Kinetics, Aqueous Solution, Azo-Dye, Basic Dye, Capacity, Cationic Dye, Composite, Composites, Concentration, Content, Data, Dye, Dye Removal, Equilibrium, Hydrogel, Hydrogel Composites, Investigation, Ionic Strength, Isotherm, Kinetics, Langmuir, Langmuir Isotherm, MB, Methylene Blue, Nanocomposite, Network, pH, Polymeric, Potential, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo Second-Order, Pseudo-Second-Order, Removal, Second Order, Second Order Kinetics, Second-Order, Second-Order Kinetics, Sodium, Sodium Dodecyl Sulfate, Solution, Sorption, Strength, Sulfate, Surfactant, Surfactants, Temperature, Thermodynamics, Time, Treatment, Vermiculite, Wastewater, Wastewater Treatment

? Zhang, J.D., Shen, Z.M., Shan, W.P., Chen, Z.Y., Mei, Z.J., Lei, Y.M. and Wang, W.H. (2010), Adsorption behavior of phosphate on Lanthanum(III) doped mesoporous silicates material. Journal of Environmental Sciences-China, 22 (4), 507-511.

Full Text: 2010\J Env Sci-Chi22, 507.pdf

Abstract: A series of lanthanum doped meosoporous MCM-41 (La(x)M41, x is Si/La molar ratio) was prepared by sol-gel method. The surface structure of the materials was investigated with X-ray diffraction and N-2 adsorption/desorption technique. The content of La in the materials was determined by ICP. It was found that the La content of La(25)M41, La(50)M41 and La(100)M41 was 7.53%, 3.89% and 2.32%, respectively. The phosphate adsorption capacities increased with increasing amount of La incorporation. With 0.40 g La25M41 99.7% phosphate could be removed. The effects of Si/La molar ratio, La(x)M41 dose, pH, initial concentration of phosphate solution, co-ions on phosphate adsorption were also evaluated. The phosphate adsorption kinetics of La(x)M41 could be well-described by the pseudo second-order model, and Langmuir isotherm fit equilibrium data much better than the Freundlich isotherm.

Keywords: Adsorption, Adsorption Capacities, Adsorption Kinetics, Adsorption, Desorption, Aqueous-Solutions, Behavior, Concentration, Content, Data, Equilibrium, Eutrophication, Freundlich, Freundlich Isotherm, Ions, Isotherm, Kinetics, Langmuir, Langmuir Isotherm, Lanthanum, Lanthanum Doped, MCM-41, Mesoporous, Mesoporous Material, Mesoporous Silicates, Model, N-2, N₂, pH, Phosphate, Phosphate Adsorption, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Removal, Second Order, Second-Order, Second-Order Model, Sol-Gel, Solution, Structure, Surface, Surface Structure, X-Ray, X-Ray Diffraction

? Yang, C.P., Wang, J.Q., Lei, M., Xie, G.X., Zeng, G.M. and Luo, S.L. (2010), Biosorption of zinc(II) from aqueous solution by dried activated sludge. Journal of Environmental Sciences-China, 22 (5), 675-680.

Full Text: 2010\J Env Sci-Chi22, 675.pdf

Abstract: The biosorption potential of dried activated sludge as a biosorbent for zinc(II) removal from aqueous solution was investigated. The effects of initial pH, contact time, initial zinc ion concentration, and adsorbent dosage on the biosorption processes were determined, and the equilibrium data were modeled by the Langmuir and Freundlich isotherms. The Langmuir isotherm model (R-2 = 0.999) was proved to fit the equilibrium data much better than the Freundlich isotherm model (R-2 = 0.918). The monolayer adsorption capacity of dried activated sludge for zinc(II) was found to be 17.86 mg/g at pH of 5 and 25ºC. The kinetic data were tested using pseudo first-and second-order models. The results suggested that the pseudo second-order model (R-2 > 0.999) was better for the description of the adsorption behavior of zinc(II) onto the dried activated sludge. Fourier transform infrared spectral analysis showed that the dominant mechanism of zinc(II) biosorption onto the dried activated sludge was the binding between amide groups and zinc ions.

Keywords: Activated Sludge, Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Behavior, Adsorption Capacity, Analysis, Aqueous Solution, Behavior, Binding, Biomass, Biosorbent, Biosorption, Cadmium(II), Capacity, Concentration, Data, Dried Activated Sludge, Equilibrium, Freundlich, Freundlich Isotherm, Freundlich Isotherm Model, Ions, Isotherm, Isotherm Model, Isotherms, Kinetic, Kinetic Data, Kinetics, Langmuir, Langmuir And Freundlich Isotherms, Langmuir Isotherm, Langmuir Isotherm Model, Lead, Mechanism, Model, Models, Monolayer, pH, Potential, Precipitation, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Removal, Second Order, Second-Order, Second-Order Model, Sludge, Solution, Spectral Analysis, Waste-Water, Zinc, Zinc Ion, Zinc(II), Zn(II)

? Velmurugan, N., Hwang, G., Sathishkumar, M., Choi, T.K., Lee, K.J., Oh, B.T. and Lee, Y.S. (2010), Isolation, identification, Pb(II) biosorption isotherms and kinetics of a lead adsorbing Penicillium sp MRF-1 from South Korean mine soil. Journal of Environmental Sciences-China, 22 (7), 1049-1056.

Full Text: 2010\J Env Sci-Chi22, 1049.pdf

Abstract: A heavy metal contaminated soil sample collected from a mine in Chonnam Province of South Korea was found to be a source of heavy metal adsorbing biosorbents. Chemical analyses showed high contents of lead (Pb) at 357 mg/kg and cyanide (CN) at 14.6 mg/kg in the soil. The experimental results showed that Penicillium sp. MRF-1 was the best lead resistant fungus among the four individual metal tolerant fungal species isolated from the soil. Molecular characterization of Penicillium sp. MRF-1 was determined using ITS regions sequences. Effects of pH, temperature and contact time on adsorption of Pb(II) by Penicillium sp. MRF-1 were studied. Favorable conditions for maximum biosportion were found at pH 4 with 3 hr contact time. Biosorption of Pb(II) gradually increased with increasing temperature. Efficient performance of the biosorbent was described using Langmuir and Freundlich isotherms. Adsorption kinetics was studied using pseudo first-order and pseudo second-order models. Biosorbent Penicillium sp. MRF-1 showed the maximum desorption in alkali conditions. Consistent adsorption/desorption potential of the biosorbent in repetitive cycles validated the efficacy of it in large scale. SEM studies given notes on surface modification of fungal biomass under metal stress and FT-IR results showed the presence of amino groups in the surface structure of the biosorbent. In conclusion, the new biosorbent Penicillium sp. MRF-1 may potentially be used as an inexpensive, easily cultivatable material for the removal of lead from aqueous solution.

Keywords: 2-Parameter, Accumulation, Adsorption, Adsorption Kinetics, Adsorption, Desorption, Analyses, Aqueous Solution, Bioaccumulation, Biomass, Biosorbent, Biosorbents, Biosorption, Biosorption Isotherms, Characterization, Copper(II), Cyanide, Desorption, Efficacy, Experimental, First Order, Freundlich, FT-IR, FTIR, Fungal, Fungal Biomass, Fungus, Growth, Heavy Metal, Heavy Metal Resistant Fungus, Identification, Ions, Isotherms, Kinetics, Korea, Langmuir, Langmuir and Freundlich Isotherms, Lead, Metal, Models, Modification, Pb, Pb(II), Penicillium sp., Performance, pH, Potential, Pseudo First Order, Pseudo First-Order, Pseudo Second Order, Pseudo Second-Order, Pseudo-First-Order, Pseudo-Second-Order, Removal, Scale, Second Order, Second-Order, SEM, Soil, Solution, Sorption, Source, Species, Stress, Structure, Surface, Surface Modification, Surface Structure, Temperature

? Zhang, X.X., Wei, C.H., He, Q.C. and Ren, Y.A. (2010), Preparation and characterization of biomimetic adsorbent from poly-3-hydroxybutyrate. Journal of Environmental Sciences-China, 22 (8), 1267-1272.

Full Text: 2010\J Env Sci-Chi22, 1267.pdf

Abstract: Biomimetic adsorbent named as PHBBMA was prepared from lipophilic poly-3-hydroxybutyrate (PHB) by a modified double emulsion solvent evaporation method. PHBBMA, characterized by using scanning electron microscope and nitrogen adsorption/desorption measurements, is porous spherical particles. The characterization with the thermal gravimetric analysis and differential scanning calorimetry, H-1 nuclear magnetic resonance and Fourier transform infrared spectroscopy showed that PHBBMA preparation was a physical process without chemical reaction. The adsorption of PHBBMA for o-nitrochlorobenzene (o-NCB) was fitted better by Langmuir model than by Freundlich model, while the pseudo second-order model fitting was better than the pseudo first-order model fitting. The maximal adsorption capacity of PHBBMA for o-NCB was 57.83 mg/g at 30ºC, although its specific surface area (S-BET) was only 8.45 m²/g. PHBBMA is a safe and environmental friendly adsorbent with high adsorption capacity because its component is innocuous and biodegradable PHB produced reusing wastes and contaminants, no byproduct can produced, and its ester and hydrocarbyl groups have strong affinity with organochlorine compounds. The further work will focus on the modification and improvement of PHBBMA in order to increase its S-BET and adsorption capacity.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Adsorption, Desorption, Analysis, Biomimetic Adsorbent, Calorimetry, Capacity, Characterization, Chemical, China, Chlorinated Pesticides, Contaminants, Double Emulsion, Emulsion, Environmental, First Order, First-Order Model, Freundlich, Freundlich Model, Improvement, Infrared Spectroscopy, Langmuir, Langmuir Model, Magnetic, Magnetic Resonance, Model, Modification, Modified, Nitrogen, Particles, Physical, Poly-3-Hydroxybutyrate, Preparation, Pseudo First Order, Pseudo First-Order, Pseudo Second Order, Pseudo Second-Order, Pseudo-First-Order, Pseudo-Second-Order, Resins, River, Second Order, Second-Order, Second-Order Model, Solvent Evaporation Technique, Specific Surface, Specific Surface Area, Spectroscopy, Surface, Surface Area, Waste, Water, Work

? Li, L., Liu, S.X. and Zhu, T. (2010), Application of activated carbon derived from scrap tires for adsorption of Rhodamine B. Journal of Environmental Sciences-China, 22 (8), 1273-1280.

Full Text: 2010\J Env Sci-Chi22, 1273.pdf

Abstract: Activated carbon derived from solid hazardous waste scrap tires was evaluated as a potential adsorbent for cationic dye removal. The adsorption process with respect to operating parameters was investigated to evaluate the adsorption characteristics of the activated pyrolytic tire char (APTC) for Rhodamine B (RhB). Systematic research including equilibrium, kinetics and thermodynamic studies was performed. The results showed that APTC was a potential adsorbent for RhB with a higher adsorption capacity than most adsorbents. Solution pH and temperature exert significant influence while ionic strength showed little effect on the adsorption process. The adsorption equilibrium data obey Langmuir isotherm and the kinetic data were well described by the pseudo second-order kinetic model. The adsorption process followed intra-particle diffusion model with more than one process affecting the adsorption process. Thermodynamic study confirmed that the adsorption was a physisorption process with spontaneous, endothermic and random characteristics.

Keywords: Activated Carbon, Activated Pyrolytic Tire Char, Adsorbent, Adsorbents, Adsorption, Adsorption Capacity, Adsorption Equilibrium, Adsorption Isotherm, Aqueous-Solution, Biomass, Capacity, Carbon, Cationic Dye, Char, Characteristics, Data, Diffusion, Diffusion Model, Dye, Dye Removal, Dyes, Endothermic, Equilibrium, Hazardous Waste, Intra-Particle Diffusion, Intraparticle Diffusion, Intraparticle Diffusion Model, Ionic Strength, Isotherm, Kinetic, Kinetic Model, Kinetics, Langmuir, Langmuir Isotherm, Mercury, Model, pH, Potential, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Pyrolysis, Removal, Research, Rhodamine B, Rubber, Second Order, Second-Order, Solution pH, Strength, Temperature, Thermodynamic, Thermodynamic Studies, Thermodynamic Study, Thermodynamics, Waste, Waste Tires

? Liu,H.W., Dong, Y.W. Wang, H.Y. and Liu, Y. (2010), Adsorption behavior of ammonium by a bioadsorbent – Boston ivy leaf powder. Journal of Environmental Sciences-China, 22 (10), 1513-1518.

Full Text: 2010\J Env Sci-Chi22, 1513.pdf

Abstract: The adsorption behaviors of ammonium ions from aqueous solution by a novel bioadsorbent, the Boston ivy (Parthenocissus tricuspidata) leaf powder (BPTL) were investigated. The SEM images and FT-IR spectra were used to characterize BPTL. The mathematical models were used to analyze the adsorption kinetics and isotherms. The optimum pH range for ammonium adsorption by BPTL was found to be 5–10. The adsorption reached equilibrium at 14 hr, and the kinetic data were well fitted by the Logistic model. The intraparticle di_usion was the main rate-controlling step of the adsorption process. The high temperature was favorable to the ammonium adsorption by BPTL, indicating that the adsorption was endothermic. The adsorption equilibrium fitted well to both the Langmuir model and Freundlich model, and the maximum monolayer adsorption capacities calculated from Langmuir model were 3.37, 5.28 and 6.59 mg N/g at 15, 25 and 35°C, respectively, which were comparable to those by reported minerals. Both the separation factor (RL) from the Langmuir model and Freundlich exponent (n) suggested that the ammonium adsorption by BPTL was favorable. Therefore, the Boston ivy leaf powder could be considered a novel bioadsorbent for ammonium removal from aqueous solution.

Keywords: Ammonium Ion, Bioadsorbent, Isotherm, Kinetics, Plant Material

? Zhan, Y.H., Zhu, Z.L., Lin, J.W., Qiu, Y.L. and Zhao, J.F. (2010), Removal of humic acid from aqueous solution by cetylpyridinium bromide modified zeolite. Journal of Environmental Sciences-China, 22 (9), 1327-1334.

Full Text: 2010\J Env Sci-Chi22, 1327.pdf

Abstract: Natural zeolite was modified by loading cetylpyridinium bromide (CPB) to create more efficient sites for humic acid (HA) adsorption. The natural and CPB modified zeolites were characterized with X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy and elemental analysis. The effects of various experimental parameters such as contact time, initial HA concentration, solution pH and coexistent Ca²⁺, upon HA adsorption onto CPB modified zeolites were evaluated. The results showed that natural zeolite had negligible affinity for HA in aqueous solutions, but CPB modified zeolites exhibited high adsorption efficiency for HA. A higher CPB loading on natural zeolites exhibited a larger HA adsorption capacity. Acidic pH and coexistent Ca²⁺ were proved to be favorable for HA adsorption onto CPB modified zeolite. The kinetic process was well described by pseudo second-order model. The experimental isotherm data fitted well to Langmuir and Sips models. The maximum monolayer adsorption capacity of CPB modified zeolite with surfactant bilayer coverage was found to be 92.0 mg/g.

Keywords: Adsorption, Adsorption Capacity, Analysis, Aqueous Solution, Aqueous Solutions, As(V), Bentonite, Bromide, Capacity, Cetylpyridinium Bromide, Concentration, Coverage, Data, Drinking-Water, Efficiency, Electron Microscopy, Emission, Experimental, Field, Hdtma-Modified Zeolite, Humic Acid, Infrared Spectroscopy, Isotherm, Kinetic, Kinetics, Langmuir, Loading, Model, Models, Modified, Modified Zeolite, Monolayer, Natural, Natural Zeolite, Natural Zeolites, pH, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Removal, Scanning Electron Microscopy, Second Order, Second-Order, Second-Order Model, Solution, Solutions, Sorption, Spectroscopy, Surfactant, Surfactant-Modified Zeolite, Waste-Water, X-Ray, X-Ray Diffraction, Zeolite, Zeolites

? Liu, H.W., Dong, Y.H., Wang, H.Y. and Liu, Y. (2010), Adsorption behavior of ammonium by a bioadsorbent - Boston ivy leaf powder. Journal of Environmental Sciences-China, 22 (10), 1513-1518.

Full Text: 2010\J Env Sci-Chi22, 1513.pdf

Abstract: The adsorption behaviors of ammonium ions from aqueous solution by a novel bioadsorbent, the Boston ivy (Parthenocissus tricuspidata) leaf powder (BPTL) were investigated. The SEM images and FT-IR spectra were used to characterize BPTL. The mathematical models were used to analyze the adsorption kinetics and isotherms. The optimum pH range for ammonium adsorption by BPTL was found to be 5-10. The adsorption reached equilibrium at 14 hr, and the kinetic data were well fitted by the Logistic model. The intraparticle diffusion was the main rate-controlling step of the adsorption process. The high temperature was favorable to the ammonium adsorption by BPTL, indicating that the adsorption was endothermic. The adsorption equilibrium fitted well to both the Langmuir model and Freundlich model, and the maximum monolayer adsorption capacities calculated from Langmuir model were 3.37, 5.28 and 6.59 mg N/g at 15, 25 and 35ºC, respectively, which were comparable to those by reported minerals. Both the separation factor (R-L) from the Langmuir model and Freundlich exponent (n) suggested that the ammonium adsorption by BPTL was favorable. Therefore, the Boston ivy leaf powder could be considered a novel bioadsorbent for ammonium removal from aqueous solution.

Keywords: Adsorption, Adsorption Capacities, Adsorption Equilibrium, Adsorption Kinetics, Adsorption Kinetics And Isotherms, Ammonium, Ammonium Ion, Ammonium Removal, Aqueous Solution, Aqueous-Solution, Behavior, Bioadsorbent, Biosorbent, Clinoptilolite, Data, Diffusion, Endothermic, Equilibrium, Exchange, Freundlich, Freundlich Model, FT-IR, FTIR, FTIR Spectra, Intraparticle Diffusion, Ion, Ions, Isotherm, Isotherms, Kinetic, Kinetics, Langmuir, Langmuir Model, Mathematical Models, Minerals, Model, Models, Monolayer, pH, Phosphate, Plant Material, Removal, SEM, Separation, Solution, Temperature, Zeolite

? Tang, Y.L., Wang, J.M. and Gao, N.Y. (2010), Characteristics and model studies for fluoride and arsenic adsorption on goethite. Journal of Environmental Sciences-China, 22 (11), 1689-1694.

Full Text: 2010\J Env Sci-Chi22, 1689.pdf

Abstract: Fluoride and arsenic are major anionic elements of concern in drinking water treatment. The effects of contact time, pH, surface loading and ionic strength on adsorption of fluoride and As(V) were investigated using batch methods. Adsorption of fluoride and As(V) onto goethite obeyed a pseudo second-order rate law. Through experimental data and adsorption kinetic analysis, the affinity of As(V) onto goethite was stronger than fluoride. Fluoride and As(V) uptake by goethite all decreased with pH increasing at the same surface loading; however, ionic strength had slight influence on their adsorption. A surface sites-species model was used to quantify the adsorption of fluoride and As(V) onto goethite as function of pH and surface loading. This model can satisfactorily predict their adsorption characteristics with several adsorption constants.

Keywords: Acid, Activated Alumina, Adsorption, Adsorption Kinetic, Analysis, Arsenic, As(V), Batch, Competitive Adsorption, Complexation, Contact Time, Data, Drinking Water, Fluoride, Goethite, Groundwater, Hematite, Kinetic, Kinetics, Magnetite, Model, pH, Phosphate, Pseudo Second Order, Pseudo-Second-Order, Second-Order, Surface, Treatment, Uptake, Water, Water Treatment

? Wang, L.A., Zhang, J., Liu, J.Z., He, H., Yang, M., Yu, J.W., Ma, Z.C. and Jiang, F. (2010), Removal of bromate ion using powdered activated carbon. Journal of Environmental Sciences-China, 22 (12), 1846-1853.

Full Text: 2010\J Env Sci-Chi22, 1846.pdf

Abstract: Bromate ion (BrO3-) removal from drinking water by powdered activated carbons (PACs) in bath mode was evaluated under various operational conditions Six kinds of PACs including wood-based carbon fruit-based carbon coal-based carbon and these three carbons thermally deoxidized in a nitrogen atmosphere were selected to investigate their capacity on BrO3- removal With the highest zeta potential value and being richly mesoporous, coal-based carbon had a high and an excellent BrO3- adsorption efficiency The removal content of BrO3- by per gram of coal-based carbon was 0 45 mg within 5 hr in 100 mu g/L bromate solution The surface characteristics of PACs and bromide formation revealed that both physical and chemical PACs properties simultaneously affected the adsorption reduction process Under acidic conditions PACs possessed high zeta value and adequate basic groups and exhibited neutral or positive charges promoting BrO3- adsorption-reduction on the carbon surface Interestingly, the PAC(s) thermally deoxidized in N-2 atmosphere optimized their properties e g increasing their zeta values and decreasing the oxygen content which accelerated the BrO3- removal rate The maximum adsorption capacity of fruit-based carbon was the highest among all tested carbons (99 6 mg/g) possibly due to its highest pore volume Remarkably the thermal regeneration of PACs in N₂ atmosphere could completely recover the adsorption capacity of PACs The kinetic data obtained from carbons was analyzed using pseudo second-order and intraparticle diffusion models, with results showing that the intraparticle diffusion was the more applicable model to describe adsorption of BrO₃^- onto PACs.

Keywords: Activated Carbon, Activated Carbons, Adsorption, Adsorption Capacity, Adsorption Reduction Process, Atmosphere, Bromate, Bromide, Capacity, Carbon, Characteristics, Chemical, Data, Diffusion, Drinking Water, Efficiency, Impact, Intraparticle Diffusion, Kinetic, Mesoporous, Mode, Model, Models, N-2, N₂, Nitrogen, Oxygen, Ozonation, Ozone, Physical, Pore Volume, Potential, Powdered Activated Carbon, Powdered Activated Carbons, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Reduction, Regeneration, Removal, Second Order, Second-Order, Solution, Surface, Value, Volume, Water, Zeta Potential

? Lin, Y.F., Chen, H.W., Lin, K.L., Chen, B. and Chiou, C. (2011), Application of magnetic particles modified with amino groups to adsorb copper ions in aqueous solution. Journal of Environmental Sciences-China, 23 (1), 44-50.

Full Text: 2011\J Env Sci-Chi23, 44.pdf

Abstract: A magnetic adsorbent can be easily recovered from treated water by magnetic force, without requiring further downstream treatment. In this research, amine-functionalized silica magnetite has been synthesized using N[3-(trimethoxysilyl)propyl]-ethylenediamine (TPED) as a surface modification agent. The synthesized magnetic amine adsorbents were used to adsorb copper ions in an aqueous solution in a batch system, and the maximum adsorption was found to occur at pH 5.5±0.1. The adsorption equilibrium data fitted the Langmuir isotherm equation reasonably well, with a maximum adsorption capacity of 10.41 mg/g. A pseudo second-order model could best describe the adsorption kinetics, and the derived activation energy was 26.92 kJ/mol. The optimum condition to desorb Cu²⁺ from NH₂/SiO₂/Fe₃O₄ was provided by a solution with 0.1 mol/L HNO₃.

Keywords: Activated Carbon, Activation, Activation Energy, Adsorb, Adsorbent, Adsorbents, Adsorption, Adsorption Capacity, Adsorption Equilibrium, Adsorption Kinetics, Amine, Aqueous Solution, Batch, Batch System, Capacity, Coated Magnetite, Copper, Copper Ion, Cu²⁺, Data, Energy, Equilibrium, Force, Hydrogel Beads, Ions, Isotherm, Kinetics, Langmuir, Langmuir Isotherm, Magnetic, Magnetic Adsorbent, Magnetic Particles, Magnetite, Mercury Ions, Metal-Ions, Model, Modification, Modified, Nanoparticles, Particles, pH, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Removal, Research, Second Order, Second-Order, Second-Order Model, Silica, SiO₂, Solution, Surface, Surface Modification, Transfer Radical Polymerization, Treatment, Water

? Li, L., Hu, Q., Zeng, J.H., Qi, H.Y. and Zhuang, G.Q. (2011), Resistance and biosorption mechanism of silver ions by Bacillus cereus biomass. Journal of Environmental Sciences-China, 23 (1), 108-111.

Full Text: 2011\J Env Sci-Chi23, 108.pdf

Abstract: Biosorption of silver ions onto Bacillus cereus biomass was investigated. Overall kinetic experiments were performed for the determination of the necessary contact time for the attainment of equilibrium. It was found that the overall biosorption process was best described by pseudo second-order kinetic model. The crystals detected by scanning electron microscope and X-ray photoelectron spectroscopy suggested the precipitation was a possible mechanism of biosorption. The molecular genetics of silver resistance of B. cereus biomass was also detected and illustrated by a whole cell sensor tool.

Keywords: Bacillus, Bacillus Cereus, Biomass, Biosensor, Biosorption, Biosorption Mechanism, Crystal, Equilibrium, Experiments, Genetics, Ions, Isotherms, Kinetic, Kinetic Model, Kinetics, Kinetics, Mechanism, Model, Precipitation, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Resistance, Second Order, Second-Order, Sensor, Silver, Spectroscopy, X-Ray, X-Ray Photoelectron Spectroscopy

? Sui, Q., Huang, J., Liu, Y.S., Chang, X.F., Ji, G.B., Deng, S.B., Xie, T. and Yu, G. (2011), Rapid removal of bisphenol A on highly ordered mesoporous carbon. Journal of Environmental Sciences-China, 23 (2), 177-182.

Full Text: 2011\J Env Sci-Chi23, 177.pdf

Abstract: Bisphenol A (BPA) is of global concern due to its disruption of endocrine systems and ubiquity in the aquatic environment. It is important, therefore, that efforts are made to remove it from the aqueous phase. A novel adsorbent, mesoporous carbon CMK-3, prepared from hexagonal SBA-15 mesoporous silica was studied for BPA removal from aqueous phase, and compared with conventional powdered activated carbon (PAC). Characterization of CMK-3 by transmission electron microscopy (TEM), X-ray diffraction, and nitrogen adsorption indicated that prepared CMK-3 had an ordered mesoporous structure with a high specific surface area of 920 m²/g and a pore-size of about 4.9 nm. The adsorption of BPA on CMK-3 followed a pseudo second-order kinetic model. The kinetic constant was 0.00049 g/(mg.min), much higher than the adsorption of BPA on PAC. The adsorption isotherm fitted slightly better with the Freundlich model than the Langmuir model, and adsorption capacity decreased as temperature increased from 10 to 40ºC. No significant influence of pH on adsorption was observed at pH 3 to 9; however, adsorption capacity decreased dramatically from pH 9 to 13.

Keywords: 17-Alpha-Ethynyl Estradiol, 17-Beta-Estradiol, Activated Carbon, Adsorption, Adsorption Characteristics, Adsorption Isotherm, Aqueous-Solutions, Bisphenol A, Characterization, CMK-3, Electron Microscopy, Endocrine Disrupting Chemicals, Estrogenic Activity, Freundlich, Isotherm, Kinetic, Kinetic Model, Langmuir, Mesoporous Carbon, Nonylphenol, pH, Pharmaceuticals, Powdered Activated Carbon, Reactive Dyes, Removal, SBA-15, Silica, Temperature, Water, X-Ray Diffraction

? Zhang, J.D., Shen, Z.M., Mei, Z.J., Li, S.P. and Wang, W.H. (2011), Removal of phosphate by Fe-coordinated amino-functionalized 3D mesoporous silicates hybrid materials. Journal of Environmental Sciences-China, 23 (2), 199-205.

Full Text: 2011\J Env Sci-Chi23, 199.pdf

Abstract: Phosphate removal from aqueous waste streams is an important approach to control the eutrophication downstream bodies of water. A Fe(III) coordinated amino-functionalized silicate adsorbent for phosphate adsorption was synthesized by a post-grafting and metal cation incorporation process. The surface structure of the adsorbent was characterized by X-ray diffraction, N-2 adsoropion/desoprotion technique, and Fourier transform infrared spectroscopy. The experimental results showed that the adsorption equilibrium data were well fitted to the Langmuir equation. The maximum adsorption capacity of the modified silicate material was 51.8 mg/g. The kinetic data from the adsorption of phosphate were fitted to pseudo second-order model. The phosphate adsorption was highly pH dependent and the relatively high removal of phosphate fell within the pH range 3.0-6.0. The coexistence of other anions in solutions has an adverse effect on phosphate adsorption; a decrease in adsorption capacity followed the order of exogenous anions: F- > SO₄^2- > NO₃^- > Cl^-. In addition, the adsorbed phosphate could be desorbed by NaOH solutions. This silicate adsorbent with a large adsorption capacity and relatively high selectivity could be utilized for the removal of phosphate from aqueous waste streams or in aquatic environment.

Keywords: Adsorbents, Adsorption, Adsorption, Aluminum, Equilibrium, Fe Coordinated, Fe(III), Kinetic, Langmuir, MCM-41, Mesoporous Material, Molecular-Sieves, pH, Phosphate, Phosphate Removal, Phosphorus Removal, Removal, Selectivity, Slag, Waste, Waste-Water, Wastewaters, Water, X-Ray Diffraction

? Vimala, R. and Das, N. (2011), Mechanism of Cd(II) adsorption by macrofungus Pleurotus platypus. Journal of Environmental Sciences-China, 23 (2), 288-293.

Full Text: 2011\J Env Sci-Chi23, 288.pdf

Abstract: The mechanism of Cd(II) uptake by the dead biomass of macrofungus Pleurotus platypus was investigated using different chemical and instrumental techniques. Sequential removal of cell wall components of the biosorbent revealed that structural polysaccharides play a predominant role in the biosorption of Cd(II). The adsorption kinetics fitted well with the pseudo second-order model suggested that the adsorption of Cd(II) on P platypus involved a chemisorption process. Transmission electron microscopy of the cadmium exposed biomass confirmed the deposition of the metal mainly in the cell wall. Fourier transform infrared spectroscopic analysis of the metal loaded biosorbent confirmed the participation of -OH, -NH and C-O-C groups in the uptake of Cd(II). Energy dispersive X-ray analysis of the biosorbent before and after metal uptake revealed that the main mechanism of adsorption was ion-exchange. The effectiveness of CaCl₂ in the desorption of cadmium perhaps suggested the exchange of Ca²⁺ with Cd(II).

Keywords: Adsorption, Adsorption Kinetics, Aqueous-Solutions, Aspergillus-niger, Biomass, Biosorbent, Biosorption, Biosorption, Cadmium, Cadmium(II), Cd(II), Desorption, Electron Microscopy, Equilibrium, Heavy-Metal Ions, Ion Exchange, Ion-Exchange, Kinetics, Macrofungus, Mechanism, Pleurotus Platypus, Removal, Sorption, Uptake, Waste-Water

? Liu, Z.Q., Yan, X.M., Drikas, M., Zhou, D.N., Wang, D.S., Yang, M. and Qu, J.H. (2011), Removal of bentazone from micro-polluted water using MIEX resin: Kinetics, equilibrium, and mechanism. Journal of Environmental Sciences-China, 23 (3), 381-387.

Full Text: 2011\J Env Sci-Chi23, 381.pdf

Abstract: The contamination of surface and ground water by bentazone has attracted increasing global concern in recent years. We conducted a detailed investigation using MIEX resin to eliminate bentazone from waters. Batch experiments were carried out to evaluate the effect of process parameters, such as retention time, resin amount, and initial pesticide concentration, on removal efficiency of bentazone. Results showed the sorption process was fast and bentazone could be efficiently removed in 30 minutes. The kinetic process of bentazone sorption on MIEX resin was well described by pseudo second-order model and intraparticle diffusion was the rate controlling step. The MIEX resin possessed the highest sorption capacity of 0.2656 mmol/mL for bentazone according to Langmuir fitting. Bentazone is a hydrophobic ionizable organic compound, and both ionic charge and hydrophobic aromatic structure governed the sorption characteristics on MIEX resin. The different removal efficiencies of ionic and non-ionic pesticides, combined with the charge balance equations of bentazone, SO₄^2-, NO₃^- and Cl^-, indicated that removal of bentazone using MIEX resin occurred primarily via ion exchange.

Keywords: Activated Carbon, Adsorption, Anion-Exchange Resins, Batch, Bentazone, Coagulation, Equilibrium, Herbicide, Ion Exchange, Ion-Exchange, Kinetic, Kinetics, Langmuir, Micro-Polluted Water, Miex Resin, Performance, Precursors, Removal, Resin, Sorption, Substances

? Wei, L.L., Wang, K., Zhao, Q.L., Xie, C.M., Qiu, W. and Jia, T. (2011), Kinetics and equilibrium of adsorption of dissolved organic matter fractions from secondary effluent by fly ash. Journal of Environmental Sciences-China, 23 (7), 1057-1065.

Full Text: 2011\J Env Sci-Chi23, 1057.pdf

Abstract: Fly ash was used as a low-cost adsorbent for removing dissolved organic matter (DOM) in secondary effluent. Batch experiments were conducted under various adsorbent dosages, pH, contact time, temperatures and DOM fractional characteristics. Under the optimum conditions of fly ash dosage of 15 g/L, temperature of 303 K and contact time of 180 min, a removal of 22.5% of the dissolved organic carbon (DOC), 23.7% of UV-254, 25.9% of the trihalomethanes precursors in secondary effluent was obtained. The adsorption of DOM fractions onto fly ash all followed the pseudo second-order kinetic model, and the hydrophilic fraction adsorption by fly ash also fitted the intraparticle diffusion model quite well. Freundlich and Langmuir models were applicable to the fly ash adsorption and their constants were evaluated. The maximum adsorption capacities of the adsorptions revealed that fly ash was more effective in adsorbing hydrophilic fraction than the acidic fractions. Structure changes of the DOM fractions after fly ash adsorption were also characterized via spectrum analyzing. Those mechanisms presented critical step toward improved efficiencies of fly ash adsorption via further surface-modification.

Keywords: Activated Carbon, Adsorbent, Adsorption, Aqueous-Solution, Batch, Diffusion, Dissolved Organic Matter, Equilibrium, Fly Ash, Fractionation, Freundlich, Freundlich and Langmuir Models, Heavy-Metals, Humic-Acid, Kinetic, Kinetic Model, Kinetics, Langmuir, Low-Cost, Low-Cost Adsorbent, pH, Pulverized Fuel Ash, Removal, Sorption, Temperature, Transformation, Waters

? Mao, Y.L., Hu, H.W. and Yan, Y.S. (2011), Biosorption of cesium(I) from aqueous solution by a novel exopolymers secreted from Pseudomonas fluorescens C-2: Equilibrium and kinetic studies. Journal of Environmental Sciences-China, 23 (7), 1104-1112.

Full Text: 2011\J Env Sci-Chi23, 1104.pdf

Abstract: The biosorption characteristics of Cs(I) ions from aqueous solution using exopolymers (PFC02) produced from Pseudomonas fluorescens C-2 were investigated as a function of pH, biosorbent dosage, contact time and initial concentration. pH played a major role in the adsorption process, and the optimum pH for the removal of Cs(I) was 8.0. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of the Cs(I) ions by PFC02. The Lagergren first-order, pseudo second-order kinetic and intraparticle diffusion models were used to test the kinetic data. Langmuir model and D-R model fitted the equilibrium data better than the Freundlich isotherm. The monolayer adsorption capacities of PFC02 as obtained from Langmuir isotherm at 25ºC was found to be 32.63 mg/g. From the D-R isotherm model, the mean free energy was calculated as 26.73 kJ/mol, indicating that the biosorption of cesium was chetmisorption. The biosorption process was rapid, and the kinetic rates were best fitted to the pseudo second-order model, which indicated the biosorption process operated through chemisorption mechanism. FT-IR analysis of PFC02 showed the possible functional groups responsible for cesium adsorption were hydroxyl, carboxyl, carbonyl and sulphonate groups. SEM analysis showed the porous structure of the material while EDX analysis confirmed the adsorption of Cs(I) on PFC02. Cesium adsorbed onto the PFC02 could be desorbed efficiently using 1 mol/L HNO₃, and the enrichment factor was 50.0. Furthermore, PFC02 could be reused five times with only about 8.25% regeneration loss. The developed method was successfully utilized for the removal of Cs(I) ions from aqueous solution.

Keywords: Adsorption, Aqueous Solution, Biosorbent, Biosorption, Cadmium, Cesium, Cs(I), Diffusion, Equilibrium, Exopolymers, Freundlich, Freundlich Isotherm, FT-IR, FTIR, FTIR Analysis, Heavy-Metals, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Isotherm, Marine-Algae, Mechanism, Pb(II), pH, Pseudomonas Fluorescens, Pseudomonas Fluorescens C-2, Removal, Saccharomyces-Cerevisiae, SEM, SEM Analysis, Sorption, Waste Biomass