Personal Research Database

Full Text: 2009\J Haz Mat169, 52.pdf

Abstract: A new chelating polymeric sorbent as an extractant-impregnated resin (EIR) has been developed using brilliant green (BG) and Amberlite XAD-7 resin. The BG-impregnated resin showed superior binding affinity for Cr(VI) in the presence of many co-existing ions and no considerable interference was observed. The influence of various physicochemical parameters on the recovery of Cr(VI) were optimized by both static and dynamic methods. The Langmuir adsorption isotherm gave a satisfactory fit of the equilibrium data. The kinetic studies performed for Cr(VI) sorption revealed that <45 min was sufficient for reaching equilibrium metal ion sorption. A preconcentration factor of 100 was found for the column-mode extraction. The spectrophotometric determination of eluted Cr(VI) was carried out using quercetin as a selective reagent. The calibration graphs were linear in the range 5.010^-13 to 4.010^-7 M with a detection limit of 810^-9 M. The proposed method has been successfully employed for the analysis of natural water. The recoveries for the Cr(VI) amounts spiked to the samples were >93%, which confirmed accuracy of the measurements. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Amberlite XAD-7, Brilliant Green, Cr(VI), Column-Mode Separation, Extractant-Impregnated Resins, Quercetin, Atomic-Absorption-Spectrometry, Solid-Phase Extraction, Chemical Cross-Linking, Chelating Resin, Adsorption Characteristics, Salmonella-Typhimurium, Chromium Speciation, Aqueous-Solution, Mode Separation, Packed-Column

? El-Sheikh, A.H., Sweileh, J.A. and Saleh, M.I. (2009), Partially pyrolyzed olive pomace sorbent of high permeability for preconcentration of metals from environmental waters. Journal of Hazardous Materials, 169 (1-3), 58-64.

Full Text: 2009\J Haz Mat169, 58.pdf

Abstract: The aim of this work is to develop a preconcentration procedure of Cd²⁺, Zn²⁺ and Cu²⁺ in environmental waters using olive pomace (OP) prior to their determination by flame atomic absorption spectrometry (FAAS). Raw OP as preconcentrating sorbent was found to have low permeability towards the passed water samples and thus long time was needed. Even reducing the vacuum pressure caused cartridge blockage. Novel preconcentrating sorbents of high permeability were then prepared by heat pretreatment under inert atmosphere (partial pyrolysis) of OP at various temperatures (100, 150, 200, 250 and 300ºC). The permeability of OP pyrolyzed at 200°C (sorbent OP-200) was enhanced 11 times relative to the raw OP, which significantly reduced the time required in the preconcentration process. A preconcentration procedure was optimized using OP-200 as preconcentrating sorbent, in which the detection limits were 42 ng L^-1 for Cu²⁺, 76 ng L^-1 for Zn²⁺ and 172 ng mL^-1 for Cd²⁺. The method was linear within the studied concentration range (2-100 ng mL^-1). The proposed method gave recoveries from 83±6 to 103±5% for determination of metals in tap water; and recoveries from 81±6 to 100±6% in well water. The method was validated by comparison with independent method and by analysis of lake sediments LKSD-4 certified reference material. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Absorption, Activated Carbons, Analysis, Aqueous-Solution, Atmosphere, Atomic Absorption Spectrometry, Atomic-Absorption-Spectrometry, Basic Properties, Bioseparation, Cadmium Ions, Cd²⁺, Comparison, Concentration, Cr(VI) Removal, Cu²⁺, Environmental, Faas, Heavy-Metals, L1, Lake, Lake Sediments, Lead Ions, Metals, Olive Waste, Permeability, Preconcentration, Pressure, Pretreatment, Procedure, Pyrolysis, Reference, Rights, Sediments, Sorbent, Sorbents, Spectrometry, Tree Fern, Vacuum, Waste-Water, Water, Water Samples, Waters, Work, Zn²⁺

? Ponnusami, V., Gunasekar, V. and Srivastava, S.N. (2009), Kinetics of methylene blue removal from aqueous solution using gulmohar (Delonix regia) plant leaf powder: Multivariate regression analysis. Journal of Hazardous Materials, 169 (1-3), 119-127.

Full Text: 2009\J Haz Mat169, 119.pdf

Abstract: Effects of process variables namely pH, dye concentration, adsorbent dosage, temperature, particle size and agitation speed on kinetics of methylene blue adsorption onto gulmohar plant leaf powder were investigated. Quadratic models were proposed to predict pseudo second order rate constant and equilibrium uptake in terms of the process variables. Model coefficients were determined by multiple regression analysis. Statistical tools like Student’s t-test, F-test, ANOVA and lack-of-fit were used to define the most important process variables. The proposed models could predict the rate constant and equilibrium dye uptake with high R² values (0.94 and 0.947). It was found that rate constant increased with decrease in concentration, decrease in particle size, increase in adsorbent dosage, increase in agitation speed and increase in temperature. Meanwhile, it was found that equilibrium dye uptake increased with increase in concentration and decrease in dosage. Apart from these combined effects of the process variables were established through multiple regression analysis. Langmuir monolayer adsorption capacity of GUL was found to be 186.22 mg/g. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Capacity, Agitation, Agricultural Waste, Analysis, Anova, Aqueous Solution, Basic Dye, Biosorption, Capacity, Carbon, Concentration, Dye, Equilibrium, Gulmohar, Isotherm, Kinetics, Langmuir, Methylene Blue, Methylene Blue Adsorption, Model, Models, Monolayer, Multiple Regression, Particle Size, pH, Pith, Plant, Pseudo Second Order, Pseudo-Second-Order, Rate Constant, Regression, Regression Analysis, Removal, Rights, Second Order, Second-Order, Size, Solution, Sorption, Sorption, Temperature, Thermodynamics, Uptake

? Qu, Y., Zhang, C.J., Li, F., Bo, X.W., Liu, G.F. and Zhou, Q. (2009), Equilibrium and kinetics study on the adsorption of perfluorooctanoic acid from aqueous solution onto powdered activated carbon. Journal of Hazardous Materials, 169 (1-3), 146-152.

Full Text: 2009\J Haz Mat169, 146.pdf

Abstract: Powdered activated carbon (PAC) was applied to remove perfluorooctanoic acid (PFOA) from the aqueous PFOA solution in this study. Contact time, adsorbent dose and temperature were analyzed as the effect factors in the adsorption reaction. The contact time of maximum PFOA uptake was around I h while the sorption removal efficiency increased with the PAC concentrations. and the process of adsorption increased from 303 K to 313 K and then decreased from 313 K to 323 K. Among four applied models, the experimental isotherm data were discovered to follow Langmuir isotherm model more closely. Thermodynamically, adsorption was endothermic because enthalpy, entropy and Gibbs constants were 198.5 kJ/mol, 0.709 kJ/mol/K and negative, respectively, which also indicated that the adsorption process was spontaneous and feasible. From kinetic analysis, the adsorption was suggested to be pseudo-second-order model. The adsorption of PFOA on the PAC was mainly controlled by particle diffusion. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorbent Dose, Adsorption, Adsorption Kinetics, Analysis, Anionic Surfactants, Aqueous Solution, Carbon, Data, Decomposition, Diffusion, Efficiency, Endothermic, Enthalpy, Entropy, Equilibrium, Experimental, Iron, Isotherm, Isotherm Model, Kinetic, Kinetic Analysis, Kinetics, Langmuir, Langmuir Isotherm, Langmuir Isotherm Model, Mechanism, Model, Models, Pac, Particle Diffusion, Perfluorinated Surfactants, Peroxisome Proliferator, PFOA, Powdered Activated Carbon, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Removal, Removal Efficiency, Rights, Sediments, Solution, Sorption, Surface-Water Samples, Temperature, Thermodynamic Parameters, Uptake

? Nie, R., Chang, X.J., He, Q., Hu, Z. and Li, Z.H. (2009), Preparation of p-tert[(dimethylamino)methyl]-calix[4]arene functionalized aminopropylpolysiloxane resin for selective solid-phase extraction and preconcentration of metal ions. Journal of Hazardous Materials, 169 (1-3), 203-209.

Full Text: 2009\J Haz Mat169, 203.pdf

Abstract: A new p-tert-[(dimethylamino)methyl]-1.3-bisglyciyl-calix[4]arene functionalized aminopropylpolysiloxane resin (APPS-CA) has been prepared and investigated for selective solid-phase extraction (SPE) of trace Cr(III), Cu(II), Ni(II), Co(II) and Zn(II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The characterization of the surface modification was performed on the basis of FT-IR spectroscopy, elemental analysis and thermal gravimetric analysis. The separation/preconcentration conditions of analytes were investigated. including effect of pH, the shaking time, the sample flow rate and volume, the elution condition, the interfering ions and stability test. At pH 4.0, the maximum adsorption capacity of Cr(III), Cu(II), Ni(II), Co(II) and Zn(II) were 47.2, 34.3, 52.8, 29.8 and 36.4 mg g(-1). respectively. The adsorbed metal ions were quantitatively eluted by 2.0 mL of 0.5 mol L-1 HCl. Common coexisting ions did not interfere with the separation. According to the definition of International Union of Pure and Applied Chemistry, the detection limits (3 sigma) of this method were found to be 0.58, 0.33, 0.47, 0.61 and 0.14 ng mL(-1) for Cr(III), Cu(II). Ni(II), Co(II) and Zn(II), respectively. The relative standard deviation under optimum conditions is less than 4.0%. The application of this new adsorbent to preconcentration trace Cr(III), Cu(II), Ni(II), Co(II) and Zn(II) of two water samples gave high accurate and precise results. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Capacity, Aminopropylpolysiloxane, Analysis, Aqueous-Solutions, Capacity, Characterization, Chemistry, Chromatographic Selectivity, Copper(II) Ions, Cr, Cu, Determination, Extraction, FT-IR, FT-IR Spectroscopy, FTIR, FTIR Spectroscopy, Heavy Metal, Heavy-Metals, Inductively Coupled Plasma Optical Emission Spectrometry, Metal Ions, Modification, Ni, P-Tert[(Dimethylamino)Methyl]-1,3-Bisglyciyl-Calix[4]Arene, pH, Polymer, Preconcentration, Preparation, Removal, Resin, Separation, Silica, Solid Phase Extraction, Solid-Phase Extraction, Spe, Stability, Stationary-Phase, Surface Modification, Volume, Water, Water Samples, Zn

? Tüzen, M., Sari, A., Mendil, D. and Soylak, M. (2009), Biosorptive removal of mercury(II) from aqueous solution using lichen (Xanthoparmelia conspersa) biomass: Kinetic and equilibrium studies. Journal of Hazardous Materials, 169 (1-3), 263-270.

Full Text: 2009\J Haz Mat169, 263.pdf

Abstract: The potential use of the lichen biomass (Xanthoparmelia conspersa) to remove mercury(II) ions from aqueous solution by biosorption was evaluated using the batch method. Effects of pH, contact time, biomass concentration and temperature on the removal of Hg(II) ions were studied. The Langmuir isotherm models defined the equilibrium data precisely compared to Freundlich model and the maximum biosorption capacity obtained was 82.8 mg g^-1. From the D-R isotherm model, the mean free energy was calculated as 9.5 kJ mol^-1. It shows that the biosorption of Hg(II) ions onto X conspersa biomass was taken place by chemical ion-exchange. Experimental data were also performed to the pseudo-first-order and pseudo-second-order kinetic models. The results indicated that the biosorption of Hg(II) on the lichen biomass followed well the second-order kinetics. Thermodynamic parameters, ΔGº, ΔHº and ΔSº indicated the Hg(II) sorption to be exothermic and spontaneous with decreased randomness at the solid-solution interface. Furthermore, the lichen biomass could be regenerated using 1 M HCl, with up to 85% recovery. which allowed the reuse of the biomass in ten biosorption-desorption cycles without any considerable loss of biosorptive removal capacity. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aqueous Solution, Aspergillus-Niger, Batch, Batch Method, Biomass, Biosorption, Biosorption-Desorption, Capacity, Chemical, Cladonia-Furcata, Concentration, Cr(III), D-R Isotherm, Data, Energy, Equilibrium, Equilibrium Studies, Exothermic, Freundlich, Freundlich Model, Fungal Biomass, Hg(II), Hg(II) Ions, Inorganic Mercury, Interface, Ion Exchange, Ion-Exchange, Ionexchange, Ions, Isotherm, Isotherm Model, Kinetic, Kinetic Models, Kinetics, Langmuir, Langmuir Isotherm, Macroalga Cystoseira-Baccata, Mercury(II), Metal-Ions, Microalgae Chlamydomonas-reinhardtii, Model, Models, pH, Potential, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Randomness, Recovery, Removal, Reuse, Rights, Second Order, Second Order Kinetics, Second-Order, Second-Order Kinetics, Solution, Sorption, Temperature, Thermodynamic, Thermodynamic Parameters, X. conspersa

? Domínguez-Vargas, J.R., Navarro-Rodríguez, J.A., de Heredia, J.B. and Cuerda-Correa, E.M. (2009), Removal of chlorophenols in aqueous solution by carbon black low-cost adsorbents. Equilibrium study and influence of operation conditions. Journal of Hazardous Materials, 169 (1-3), 302-308.

Full Text: 2009\J Haz Mat169, 302.pdf

Abstract: The adsorption process of chlorophenols (CPs) by low-cost adsorbents such as carbon blacks has been studied. The influence of different parameters such as temperature, pH, ionic strength and textural properties of the adsorbents on the adsorption process of pentachlorophenol has been analyzed. The adsorption process is exothermal and parameters such as pH and ionic strength exert a noticeable influence on the adsorption capacity of the solute. These parameters influence the adsorption capacity in an opposite manner. Thus an increase in pH seems to unfavor the adsorption process, whereas the adsorption capacity increases with increasing ionic strength. In order to analyze the influence of the number of chlorine atoms in the molecule of solute the adsorption process of different chlorophenols (i.e., 4-chlorophenol, 3,5-dichlorophenol, 2,4,6-trichlorophenol and 2,3,4,6-tetrachlorophenol) was analyzed. As the number of chlorine atoms (and thus the volume of the molecule) increases, the penetration of the solute through the porous texture of the adsorbent is difficult and, consequently, the adsorption capacity decreases. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: 2-Chlorophenol, Activated Carbon, Adsorption, Adsorption Capacity, Adsorption In Liquid Phase, Aqueous, Biosorption, Capacity, Carbon, Carbon Black, Chlorophenols, Elsevier, Equilibrium, Kinetics, Liquid-Membrane, Low-Cost Adsorbents, Organic Pollutants Removal, Oxidation, pH, Phenol, Removal, Solute, Surface-Chemistry, Temperature, Water

? Qadri, S., Ganoe, A. and Haik, Y. (2009), Removal and recovery of acridine orange from solutions by use of magnetic nanoparticles. Journal of Hazardous Materials, 169 (1-3), 318-323.

Full Text: 2009\J Haz Mat169, 318.pdf

Abstract: Here we report a separation of a cationic dye, acridine orange (AO), by use of magnetic nanoparticles (gamma-Fe₂O₃). The particles were showed to capture 98% of the dye within the first 20 min of contact time. The maximum sorption capacity of the magnetic nanoparticles (MNPs) for AO was 59 mg/g. The sorption isotherms fit well with the Freundlich model. The sorption kinetics fits well the pseudo-second-order rate equation model. 60-90% dye recovery was achieved by rotary evaporating the dye bearing nanoparticles in acetone. The nanoparticles were recycled for additional dye removal. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Acetone, Acridine Orange, Aqueous-Solution, Azo Dyes, Capacity, Carbon Nanotubes, Cationic Dye, Dye, Dye Adsorption, Dye Recovery, Dye Removal, Equilibrium, First, Freundlich, Freundlich Model, Husk, Isotherms, Kinetics, Laccase, Magnetic, Magnetic Nanoparticles, Model, Nanoparticles, Particles, Peanut Hull, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Rate, Recovery, Removal, Rights, Separation, Solutions, Sorption, Sorption Capacity, Sorption Isotherms, Sorption Kinetics, Textile Dye

? Alkaram, U.F., Mukhlis, A.A. and Al-Dujaili, A.H. (2009), The removal of phenol from aqueous solutions by adsorption using surfactant-modified bentonite and kaolinite. Journal of Hazardous Materials, 169 (1-3), 324-332.

Full Text: 2009\J Haz Mat169, 324.pdf

Abstract: The natural bentonite (BC) and kaolinite (KC) were modified with two surfactant of hexadecyltrimethylammonium bromide (HDTMA) and phenyltrimethylammonium bromide (PTMA) to form four kinds of organic-modified clays, i.e., HDTMA-bentonite (BHM), HDTMA-kaolinite (KHM), PTMA-bentonite (KPM) and PTMA-kaolinite (KPM). The modified minerals were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) and FT-IR spectroscopy. The surface areas were determined using methylene blue adsorption method. Cation-exchange capacity (CEC) was estimated using an ethylenediamine complex of copper method and the modifier loading was calculated from the total carbon analysis. The ability of raw and organo-modified clays to remove phenol from aqueous solutions has been carried out as a function of contact time, pH and temperatures using a batch technique. The removal of phenol from aqueous solutions by modified clays seems to be more effective than unmodified samples. The adsorption capacity was found to increase with increasing temperature indication that the adsorptions were endothermic. The adsorption of phenol onto these clays was found to be increased by increasing of pH value and the adsorption patterns data are correlated well by Langmuir and Freundlich isotherm models and that the adsorption is physical in nature. The experimental data fitted very well with the pseudo-second-order kinetic model. The thermodynamic study of adsorption process showed that the adsorption of phenol with these six adsorbents was carried out spontaneously, and the process was endothermic in nature. (C) 2009 Published by Elsevier B.V.

Keywords: Adsorbents, Adsorption, Adsorption Capacity, Analysis, Aqueous Solutions, Batch, Bentonite, Bromide, Capacity, Carbon, CEC, Chlorinated Phenols, Clay, Clays, Copper, Data, Dye, Endothermic, Ethylenediamine, Experimental, Fluorescence, Freundlich, Freundlich Isotherm, FT-IR, FTIR, FTIR Spectroscopy, Function, HDTMA, Hexadecyltrimethylammonium, Indication, Isotherm, Kaolinite, Kinetic, Kinetic Model, Langmuir, Loading, Methylene Blue, Methylene Blue Adsorption, Methylene-Blue, Minerals, Model, Models, Modified, Modified Clays, Natural, Organo-Modified, pH, pH Value, Phase, Phenol, Physical, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, PTMA, Removal, Solutions, Sorption, Spectroscopy, Surface, Surface Areas, Surfactant, Temperature, Thermodynamic, Total Carbon, Value, X-Ray, X-Ray Diffraction, XRD

? Mohan, S. and Gandhimathi, R. (2009), Removal of heavy metal ions from municipal solid waste leachate using coal fly ash as an adsorbent. Journal of Hazardous Materials, 169 (1-3), 351-359.

Full Text: 2009\J Haz Mat169, 351.pdf

Abstract: The purpose of this study was to investigate the possibility of the utilization of coal fly ash as a low cost adsorbent material for the adsorption of heavy metal ions (Zn, Pb, Cd, Mn and Cu) present in the municipal solid waste leachate. Batch experiments were conducted to determine the effect of contact time and fly ash dosage on adsorption of heavy metals. Experimental data were evaluated to find out kinetic characteristics of the adsorption process. The isothermal data could be well described by the Freundlich adsorption model. Kinetic parameters of adsorption such as the pseudo first-order constant, pseudo second-order constant and the intraparticle diffusion rate constant were determined. The fly ash concentration required to achieve maximum heavy metal removal was found to be 2 g/L with the removal efficiencies of 39%, 28%, 74%, 42% and 71% for Cu. Mn, Pb, Zn and Cd respectively. The results of the study demonstrated that the fly ash could be used as an effective low cost adsorbent for the removal of heavy metal ions from municipal solid waste leachate. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Isotherms, Adsorption Kinetics, Aqueous-Solutions, Cadmium(II), Cd, Characteristics, Classification, Coal, Coal Fly Ash, Concentration, Cost, Cu, Data, Diffusion, Experiments, First Order, Fly Ash, Freundlich, General Treatment, Heavy Metal, Heavy Metal Ions, Heavy Metal Removal, Heavy Metals, Intraparticle Diffusion, Ions, Isothermal, Kinetic, Kinetic Parameters, Landfill Leachates, Leachate, Low Cost, Low Cost Adsorbent, Low-Cost Adsorbents, Metal, Metal Ions, Metals, Model, Municipal Solid Waste, Pb, Pseudo First Order, Pseudo First-Order, Pseudo Second Order, Pseudo Second-Order, Pseudo-First-Order, Pseudo-Second-Order, Purpose, Rate Constant, Removal, Rights, Second Order, Second-Order, Soils, Solid Waste, Solute Adsorption-Isotherm, Sorption, Utilization, Waste, Water

? Di Natale, F., Erto, A., Lancia, A. and Musmarra, D. (2009), A descriptive model for metallic ions adsorption from aqueous solutions onto activated carbons. Journal of Hazardous Materials, 169 (1-3), 360-369.

Full Text: 2009\J Haz Mat169, 360.pdf

Abstract: The design of adsorber units is mainly dependent on the equilibrium adsorption capacity of the sorbent in the working conditions. At the moment, these data are available in a limited number of experimental conditions and, for the case of activated carbon, there are no predictive models to assess the adsorption capacity as a function of the process parameters. This makes the adsorber design a complex and approximated task. In this work, a model for the description of metallic ions absorption onto activated carbon is presented. The model starts from an evaluation of ion speciation and it considers the approach of the multi-component Langmuir model to correlate the metal uptake to the ion concentration in solution. The model has been used to analyse available experimental data on the adsorption of As(V), Cd(II), Cr(III) and Cr(VI) ions on activated carbon. A good matching between experimental results and model predictions has been obtained for all the investigated conditions. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Absorption, Activated Carbon, Adsorber Design, Adsorption, Adsorption Capacity, Adsorption Model, Aqueous, Aqueous Solution, As(III), As(V), Capacity, Carbon, Cd, Chromium, Complex, Cr(VI), Elsevier, Equilibrium, Evaluation, Metal, Metallic Ions, Models, Removal, Solutions, Sorption, Speciation

? Tsimas, E.S., Tyrovola, K., Xekoukoulotakis, N.P., Nikolaidis, N.P., Diamadopoulos, E. and Mantzavinos, D. (2009), Simultaneous photocatalytic oxidation of As(III) and humic acid in aqueous TiO₂ suspensions. Journal of Hazardous Materials, 169 (1-3), 376-385.

Full Text: 2009\J Haz Mat169, 376.pdf

Abstract: The simultaneous photocatalytic oxidation of As(Ill) and humic acid (HA) in aqueous Degussa P25 TiO(2) suspensions was investigated. Preliminary photocatalytic studies of the binary As(III), TiO(2) and HA, TiO(2) systems showed that As(III)was oxidized more rapidly than HA and the extent of photocatalytic oxidation of each individual component (i.e. As(Ill) or HA) increased with decreasing its initial concentration and, or increasing catalyst loading. The simultaneous photocatalytic oxidation of As(Ill) and HA in the ternary As(III), HA, TiO(2) system showed that both As(Ill) and HA oxidation was reduced in the ternary system compared to the corresponding binary systems. The effect of operating conditions in the ternary system, such as initial As(III), HA and TiO(2) concentrations (in the range 3-20 mg, L, 10-100 mg, L and 50-250 mg, L respectively), initial solution pH (3.6-6.7) and reaction time (10-30 min), on photocatalytic As(III) and HA oxidation was assessed implementing a two-level factorial experimental design methodology. Seven and ten factors were found statistically important in the case of photocatalytic As(Ill) and HA oxidation respectively. Based on these statistically significant factors, a first order polynomial model describing As(III) and HA photocatalytic oxidation was constructed and a very good agreement was obtained between the experimental values and those predicted by the model, while the observed differences may be readily explained as random noise. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Arsenic, Arsenic Removal, As(III), Degradation, Design, Experimental, Factorial Design, First Order, Humic Acid, Kinetics, Mechanism, Methodology, Model, Noise, Organic-Matter, Oxidation, pH, Photocatalysis, TiO₂, Titanium-Dioxide, Water, Water, Zero-Valent Iron

? Li, Z.Z., Tang, X.W., Chen, Y.M., Wei, L.M. and Wang, Y. (2009), Activation of Firmiana Simplex leaf and the enhanced Pb(II) adsorption performance: Equilibrium and kinetic studies. Journal of Hazardous Materials,