Personal Research Database

Full Text: 2007\J Haz Mat145, 331.pdf

Abstract: Comparison analysis of linear least square method and nonlinear least square method for estimating the kinetic parameters was made using the experimental column data of methylene blue (MB) adsorption onto zeolite at different flow rates and initial concentration. The data were fitted to Thomas model equations using linear and nonlinear regressive analysis, respectively. The error analysis was performed. Present investigation showed that the linear and nonlinear methods are both suitable to predict the breakthrough curves using Thomas model parameters and the nonlinear method is better.

Keywords: Adsorption, Analysis, Breakthrough, Breakthrough Curves, Column, Concentration, Data, Error, Error Analysis, Experimental, Fixed Bed, Flow, Investigation, Kinetic, Kinetic Parameters, Linear Analysis, MB, Methods, Methylene Blue, Methylene Blue Adsorption, Model, Natural, Natural Zeolite, Nonlinear Analysis, Rates, Thomas Model, Zeolite

? Gao, R.Y. and Wang, J.L. (2007), Effects of pH and temperature on isotherm parameters of chlorophenols biosorption to anaerobic granular sludge. Journal of Hazardous Materials, 145 (3), 398-403.

Full Text: 2007\J Haz Mat145, 398.pdf

Abstract: As the most important parameters affecting the biosorption, pH and temperature were studied in this paper in order to more completely understand their effects on chlorophenols’ biosorption onto anaerobic granular sludge. Sorption isotherms of 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) at various temperatures were determined; the data of 4-CP could be simulated by Langnmir model, while the data of 2,4-DCP could only be reproduced by Freudlich equation. The uptake capacity of 4-CP and 2,4-DCP could reach 1.5 mg g^-1 and 5.04 mg g^-1 when 2,4-DCP concentration was 90 mg L^-1 and 4-CP concentration was 107 mg L^-1, respectively. 2,4-DCP was more strongly adsorbed onto the anaerobic granular sludge than 4-CP, which might be correlated with the numbers of chlorine substitute. The Experiments studying pH effects showed that the adsorption capacity of 4-CP and 2,4-DCP was quite pH dependent and increased with decrease in pH. (c) 2006 Elsevier B.V. All rights reserved.

Keywords: Chlorophenol, pH, Temperature, Biosorption, Anaerobic Granular Sludge, Activated-Sludge, Phenol, Sorption, Removal, PCP

? Hanif, M.A., Nadeem, R., Zafar, M.N., Akhtar, K. and Bhatti, H.N. (2007), Kinetic studies for Ni(II) biosorption from industrial wastewater by Cassia fistula (Golden Shower) biomass. Journal of Hazardous Materials, 145 (3), 501-505.

Full Text: 2007\J Haz Mat145, 501.pdf

Abstract: The present study explores the ability of Cassia fistula waste biomass to remove Ni(II) from industrial effluents. C.fistula biomass was found very effective for Ni(II) removal from wastewater of Ghee Industry (GI), Nickel Chrome Plating Industry (Ni-Cr PI), Battery Manufacturing Industry (BMI), Tanner Industry: Lower Heat Unit (TILHU), Tannery Industry: Higher Heat Unit (TIHHU), Textile Industry: Dying Unit (TIDU) and Textile Industry: Finishing Unit (TIFU). The initial Ni(II) concentration in industrial effluents was found to be 34.89±0.01, 183.56±0.08, 21.19±0.01, 43.29±0.03, 47.26±0.02, 31.38±0.01 and 31,09 0.01 mg/L in GI, Ni-Cr PI, BMI, TILHU, TIHHU, TIDU and TIFU, respectively. After biosorption the final Ni(II) concentration in industrial effluents was found to be 0.05±0.01, 17.26±0.08, 0.03 0.01, 0.05±0.01, 0.1±0.01, 0.07±0.01 and 0.06±0.01 mg/L in GI, Ni-Cr PI, BMI, TILHU, TIHHU, TIDU and TIFU, respectively. The % sorption Ni(11) ability of C. fistula from seven industries included in present study tend to be in following order: TILHU (99.88) > GI (99.85) approximate to BMI (99.85) > TIFU (99.80) > TIHHU (99.78) > TIDU (99.77) >> Ni-Cr PI (90.59). Sorption kinetic experiments were performed in order to investigate proper sorption time for Ni(II) removal from wastewater. Batch metal ion uptake capacity experiments indicated that sorption equilibrium reached much faster in case of industrial wastewater samples (480 min) in comparison to synthetic wastewater (1440 min) using same biosorbent. The kinetic data were analyzed in term of pseudo-first-order and pseudo-second-order expressions. Pseudo-second-order model described well the sorption kinetics of Ni(II) onto C. fistula biomass from industrial effluents in comparison to pseudo-first-order kinetic model. Due to unique high Ni(II) sorption capacity of C. fistula waste biomass it can be concluded that it is an excellent. biosorbent for Ni(II) uptake from industrial effluents. (c) 2007 Elsevier B.V All rights reserved.

Keywords: Aqueous-Solutions, Biomass, Biosorbent, Biosorption, Cadmium Removal, Capacity, Cassia Fistula, Comparison, Concentration, Copper, Effective, Effluents, Equilibrium, Fistula, Heavy-Metal Adsorption, Industrial, Industrial Effluents, Industrial Wastewater, Industries, Ion, Ions, Kinetic, Kinetic Model, Kinetics, Metal, Metal Ion, Model, Ni(II), Order, Pollution, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Removal, Sorption, Sorption Capacity, Sorption Equilibrium, Sorption Kinetics, Synthetic, Synthetic Wastewater, Time, Uptake, Vulgaris, Waste, Waste Biomass, Wastewater, Zinc

? Yang, H.Q., Xu, Z.H., Fan, M.H., Bland, A.E. and Judkins, R.R. (2007), Adsorbents for capturing mercury in coal-fired boiler flue gas. Journal of Hazardous Materials, 146 (1-2), 1-11.

Full Text: 2007\J Haz Mat146, 1.pdf

Abstract: This paper reviews recent advances in the research and development of sorbents used to capture mercury from coal-fired utility boiler flue gas.

Mercury emissions are the source of serious health concerns. Worldwide mercury emissions from human activities are estimated to be 1000 to 6000 t/annum. Mercury emissions from coal-fired power plants are believed to be the largest source of anthropogenic mercury emissions.

Mercury emissions from coal-fired utility boilers vary in total amount and speciation, depending on coal types, boiler operating conditions, and configurations of air pollution control devices (APCDs). The APCDs, such as fabric filter (FF) bag house, electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD), can remove some particulate-bound and oxidized forms of mercury. Elemental mercury often escapes from these devices. Activated carbon injection upstream of a particulate control device has been shown to have the best potential to remove both elemental and oxidized mercury from the flue gas. For this paper, NORIT FGD activated carbon was extensively studied for its mercury adsorption behavior. Results from bench-, pilot- and field-scale studies, mercury adsorption by coal chars, and a case of lignite-burned mercury control were reviewed.

Studies of brominated carbon, sulfur-impregnated carbon and chloride-impregnated carbon were also reviewed. Carbon substitutes, such as calcium sorbents, petroleum coke, zeolites and fly ash were analyzed for their mercury-adsorption performance. At this time, brominated activated carbon appears to be the best-performing mercury sorbent.

A non-injection regenerable sorbent technology is briefly introduced herein, and the issue of mercury leachability is briefly covered. Future research directions are suggested.

Keywords: Mercury, Sorbent, Adsorption, Activated Carbon, Flue Gas

? Fujiwara, K., Ramesh, A., Maki, T., Hasegawa, H. and Ueda, K. (2007), Adsorption of platinum(IV), palladium(II) and gold(III) from aqueous solutions onto L-lysine modified crosslinked chitosan resin. Journal of Hazardous Materials, 146 (1-2), 39-50.

Full Text: 2007\J Haz Mat146, 39.pdf

Abstract: Crosslinked chitosan resin chemically modified with l-lysine has been used to investigate the adsorption of Pt(IV), Pd(II) and Au(III) from aqueous solutions. Batch adsorption studies were carried out with various parameters, such as initial metal ion concentration, contact time, pH and temperature. The maximum adsorption capacity was found at pH 1.0 for Pt(IV), at pH 2.0 for Au(III) and Pd(II). Langmuir and Freundlich isotherm models were applied to analyze the experimental data. The best interpretation for the experimental data was given by the Langmuir isotherm and the maximum adsorption capacity was found to be 129.26 mg/g for Pt(IV), 109.47 mg/g for Pd(II) and 70.34 mg/g for Au(III). The kinetic data was tested using pseudo-first-order and pseudo-second-order kinetic models. Kinetic data correlated well with the pseudo-second-order kinetic model, indicating that the chemical sorption was the rate-limiting step. Thermodynamic parameters like Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were evaluated by applying the Van’t Hoff equation. The thermodynamic study indicated that the adsorption process is spontaneous and exothermic in nature. The desorption studies were carried out using various reagents. The maximum percent desorption of precious metal ions were obtained when the reagent 0.7 M thiourea–2 M HCl was used.

Keywords: Adsorption, Adsorption Capacity, Adsorption Process, Aqueous Solutions, Au(III), Capacity, Chelating Resin, Chemical, Chitosan, Concentration, Contact Time, Crosslinked, Crosslinked Chitosan Resin, Derivatives, Desorption, Desorption Studies, Energy, Enthalpy, Entropy, Exothermic, Experimental, Experimental Data, Free Energy, Freundlich, Freundlich Isotherm, Gibbs Free Energy, HCl, Ion, Isotherm, Isotherm Models, Kinetic, Kinetic Model, Kinetic Models, Kinetics, Kinetics, L-Lysine, Langmuir, Langmuir and Freundlich Isotherm, Langmuir Isotherm, Langmuir-Isotherm, Lmccr, Metal, Metal Ion, Metal Ion Concentration, Metal Ions, Metal-Ions, Model, Models, Modified, Parameters, Pd(II), pH, Preconcentration, Process, Pseudo Second Order, Pseudo Second Order Kinetic, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Pt(IV), Rate Limiting, Rate Limiting Step, Rate-Limiting Step, Recovery, Resin, Selective Adsorption, Solutions, Sorption, Spectrometry, Spontaneous, Temperature, Thermodynamic, Thermodynamic Study, Thermodynamics, Time, Water Samples

? Ding, P., Huang, K.L., Li, G.Y. and Zeng, W.W. (2007), Mechanisms and kinetics of chelating reaction between novel chitosan derivatives and Zn(II). Journal of Hazardous Materials, 146 (1-2), 58-64.

Full Text: 2007\J Haz Mat146, 58.pdf

Abstract: Modified chitosan such as chitosan alpha-ketoglutaric acid (KCTS) and hydroxamated chitosan alpha-ketoglutaric acid (HKCTS) are successfully prepared. The resulting polymers were characterized by C-13 NMR and X-ray diffraction (XRD), respectively. A adsorption system was applied to study the adsorption of Zn(II) ion onto chitosan derivatives. The isothermal sorption kinetics of chitosan derivatives for Zn(II) ion has been investigated. The kinetics experimental data correlated well with the second-order kinetic model, indicating that the chemical sorption was the rate-limiting step. The adsorption mechanism of chitosan derivatives with Zn(II) was studied by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The results indicated that the nitrogen in amino group and the oxygen in carboxyl group of KCTS were coordination atoms. N atom of amino group, O atom of hydroxamic acid and O atom of carbonyl group in HKCTS coordinated with Zn(OO). (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Acid, Adsorption, Adsorption Isotherm, Adsorption Mechanism, Aqueous-Solution, Beads, C-13, C-13 NMR, C-13-NMR, Carbonyl, Carbonyl Group, Carboxyl, Chelating Reaction, Chemical, Chitosan, Chitosan Derivatives, Coordination, Dye, Equilibrium, Experimental, Experimental Data, Fourier Transform Infrared Spectroscopy, FT-IR, FTIR, Group, Infrared Spectroscopy, Ion, Isothermal, Kinetic, Kinetic Model, Kinetics, Mechanism, Metal-Ions, Model, Nitrogen, NMR, Oxygen, Photoelectron Spectroscopy, Polymers, Rate Limiting, Rate Limiting Step, Rate-Limiting Step, Reaction, Second Order, Sorption, Sorption Kinetics, Spectroscopy, X-Ray Diffraction, X-Ray Photoelectron Spectroscopy, XPS, XRD, Zn(II), Zn(II) Ion

? Han, X., Wong, Y.S., Wong, M.H. and Tam, N.F.Y. (2007), Biosorption and bioreduction of Cr(VI) by a microalgal isolate, Chlorella miniata. Journal of Hazardous Materials, 146 (1-2), 65-72.

Full Text: 2007\J Haz Mat146, 65.pdf

Abstract: The ability and mechanism of a microalgal isolate, Chlorella miniata to remove Cr(VI) were investigated. Kinetic studies indicated that both biosorption and bioreduction were involved in the Cr(VI) removal. The adsorbed Cr(VI) was reduced to Cr(III), and desorption studies indicated that Cr(III) occupied most of the adsorption sites on the biomass. The equilibrium time for Cr(VI) removal was dependent on various factors including initial pH, biomass and Cr(VI) concentrations. Equilibrium study showed that the Cr(VI) removal capacity was negatively related to the initial pH, and the biosorption capacity of total Cr [Cr(III) and Cr(VI)] reached the maximum at initial pH of 3.0. The spectrum of Fourier Transform Infrared Spectrometer analysis (FTIR) further confirmed that amino group on the algal biomass was the main adsorption site for Cr(VI) biosorption in acidic pH while the reduced Cr(III) was mainly sequestered by carboxylate group. The comparison between biosorption–bioreduction and direct bioreduction kinetic models proved that biosorption of Cr(VI) was the first step, followed by Cr(VI) bioreduction and Cr(III) biosorption on the algal biomass.

Keywords: Algae, Biosorption, Hexavalent Chromium, Trivalent Chromium, Bioreduction

? Zainal, Z., Lee, C.Y., Hussein, M.Z., Kassim, A. and Yusof, N.A. (2007), Electrochemical-assisted photodegradation of mixed dye and textile effluents using TiO₂ thin films. Journal of Hazardous Materials, 146 (1-2), 73-80.

Full Text: 2007\J Haz Mat146, 73.pdf

Abstract: Mixed dye consists of six commercial dyes and textile effluents from cotton dyeing process were treated by electrochemical-assisted photodegradation under halogen lamp illumination. Two types of effluents were collected which are samples before and after undergone pre-treatment at the factory wastewater treatment plant. The photodegradation process was studied by evaluating the changes in concentration employing UV-vis spectrophotometer (UV-vis) and total organic carbon (TOC) analysis. The photoelectrochemical degradation of mixed dye was found to follow the Langmuir Hinshelwood pseudo-first order kinetic while pseudo-second order kinetic model for effluents by using TOC analyses. The chemical oxygen demand (COD) and biochemical oxygen demand (BOD) values of mixed dye and raw effluents were reported. Photoelectrochemical characteristic of pollutants was studied using the cyclic voltammetry technique. Raw effluent was found to exhibit stronger reduction behaviour at cathodic bias potential but slightly less photoresponse at anodic bias than mixed dye.

Keywords: Analyses, Analysis, Behaviour, Bias, Biochemical Oxygen Demand, BOD, Carbon, Changes, Chemical, Chemical Oxygen Demand, COD, Concentration, Degradation, Demand, Dye, Dyes, Effluents, Electrochemical-Assisted, Kinetic, Kinetic Model, Langmuir, Mixed Dye, Model, Organic, Organic Carbon, Oxygen, Photodegradation, Plant, Pollutants, Potential, Pre-Treatment, Pretreatment, Pseudo First Order, Pseudo Second Order, Pseudo-First Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second-Order, Reduction, Textile Effluents, TiO₂, TOC, Treatment, Wastewater, Wastewater Treatment, Wastewater Treatment Plant

? Atar, N. and Olgun, A. (2007), Removal of acid blue 062 on aqueous solution using calcinated colemanite ore waste. Journal of Hazardous Materials, 146 (1-2), 171-179.

Full Text: 2007\J Haz Mat146, 171.pdf

Abstract: Colemanite ore waste (CW) has been employed as adsorbent for the removal of acid blue 062 anionic dye (AB 062) from aqueous solution. The adsorption of AB 062 onto CW was examined with respect to contact time, calcination temperature, particle size, pH, adsorbent dosage and temperature. The physical and chemical properties of the CW, such as particle sizes and calcinations temperature, play important roles in dye adsorption. The dye adsorption largely depends on the initial pH of the solution with maximum uptake occurring at pH 1.Three simplified kinetics models, namely, pseudo-first order, pseudo-second order, and intraparticle diffusion models were tested to investigate the adsorption mechanisms. The kinetic adsorption of AB 062 on CW follows a pseudo-second order equation. The adsorption data have been analyzed using Langmuir and Freundlich isotherms. The results indicate that the Langmuir model provides the best correlation of the experimental data. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of the adsorption of dye onto CW. (C) 2006 Elsevier B.V. All rights reserved.

Keywords: Acid, Acidic Dye, Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Mechanisms, Anionic, Anionic Dye, Aqueous Solution, Bottom Ash, Calcination, Chemical, Chemical Properties, Colemanite Ore Waste, Column Operations, Contact Time, Correlation, De-Oiled-Soya, Diffusion, Diffusion Models, Dosage, Dye, Dye Adsorption, Dye Removal, Energy, Enthalpy, Entropy, Equilibrium Uptake, Experimental, Experimental Data, Fly-Ash, Free Energy, Freundlich, Freundlich Isotherms, Intraparticle Diffusion, Isotherms, Kinetic, Kinetic Adsorption, Kinetics, Langmuir, Langmuir and Freundlich Isotherms, Langmuir Model, Low-Cost Adsorbents, Malachite Green, Mechanisms, Methylene-Blue, Model, Models, Order, Parameters, Particle, Particle Size, pH, Physical, Properties, Pseudo Second Order, Pseudo-First Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second-Order, Removal, Size, Sorption Dynamics, Temperature, Thermodynamic, Thermodynamic Parameters, Time, Uptake, Waste

? Seyhan, S., Seki, Y., Yurdakoc, M. and Merdivan, M. (2007), Application of iron-rich natural clays in Çamlica, Turkey for boron sorption from water and its determination by fluorimetric-azomethine-H method. Journal of Hazardous Materials, 146 (1-2), 180-185.

Full Text: 2007\J Haz Mat146, 180.pdf

Abstract: In this study, iron-rich natural Çamlica Bentonites, CB1 and CB2, were used for the sorption of boron in water samples. Boron was determined by newly progressed fluorimetric azomethine-H method. The optimum conditions found using factorial designs are pH 10, 45 °C, 0.250 g of clay and 20 mL of sample volume. It was found that 180 min is enough time for the equilibrium state to be reached in boron adsorption. At these conditions, boron sorption percentage was 80% for CB1 and 30% for CB2. The adsorption isotherms are well described by linear Freundlich model. Various geothermal waters in our country were also studied for boron sorption.

Keywords: Boron, Sorption, Factorial Design, Iron-Rich Clay

? Ayar, A., Gezici, O. and Küçükosmanoğlu, M. (2007), Adsorptive removal of Methylene blue and Methyl orange from aqueous media by carboxylated diaminoethane sporopollenin: On the usability of an aminocarboxilic acid functionality-bearing solid-stationary phase in column techniques. Journal of Hazardous Materials, 146 (1-2), 186-193.

Full Text: 2007\J Haz Mat146, 186.pdf

Abstract: The adsorption phenomena of Methylene blue (MB) and Methyl orange (MO) on a carboxylated diaminoethane sporopollenin (CDAE-S) solid phase were investigated in a column arrangement by using breakthrough technique. The adsorption phenomena were evaluated using some common adsorption isotherm models and Scatchard plot analysis, and obtained results were interpreted for evaluating the usability of CDAE-S for removal, recovery and preconcentration of the studied dyes both at the laboratory and industrial scales. On the basis of Scatchard plot analysis, the interaction types between the CDAE-S and the studied dyes were criticized in terms of affinity phenomena. Thus, the usability of a biomacromolecule-derived material, CDAE-S, as a cheap, environmentally-friendly and effective solid-stationary phase exhibiting both cation-exchange and anion-exchange characteristics at the same time, is discussed through the present study. Besides, from the obtained results, the protonated CDAE-S, which functionally resembles an amino acid structure, are presented as a two-in-one solid-stationary phase, and its adaptability to common processes performed under column conditions is also drawn in detail.

Keywords: Breakthrough Curve, Dye, HPLC, Ion-Exchange, Scatchard Plot Analysis, Sorption, SPE

? Önal, Y., Akmil-Başar, Ç. and Sarıcı-Özdemir, Ç. (2007), Investigation kinetics mechanisms of adsorption malachite green onto activated carbon. Journal of Hazardous Materials, 146 (1-2), 194-203.

Full Text: 2007\J Haz Mat146, 194.pdf

Abstract: Lignite was used to prepare activated carbon (T3K618) by chemical activation with KOH. Pore properties of the activated carbon such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by t-plot based on N₂ adsorption isotherm. BET surface area of activated carbon is determined as 1000 m²/g. Adsorption capacity of malachite green (MG) onto T3K618 activated carbon was investigated in a batch system by considering the effects of various parameters like initial concentration (100, 150 and 200 mg/L) and temperature (25, 40 and 50 °C). The adsorption process was relatively fast and equilibrium was reached after about 20 min for 100, 150 mg/L at all adsorption temperature. Equilibrium time for 200 mg/L was determined as 20 min and 40 min at 298, 313 and 323 K, respectively. Simple mass and kinetic models were applied to the experimental data to examine the mechanisms of adsorption and potential rate controlling steps such as external mass transfer, intraparticle diffusion. Pseudo second-order model was found to explain the kinetics of MG adsorption most effectively. It was found that both mass transfer and pore diffusion are important in determining the adsorption rates. The intraparticle diffusion rate constant, external mass transfer coefficient, film and pore diffusion coefficient at various temperatures were evaluated. The activation energy (E_a) was determined as 48.56, 63.16, 67.93 kJ/mol for 100, 150, 200 mg/L, respectively. The Langmiur and Freundlich isotherm were used to describe the adsorption equilibrium studies at different temperatures. Langmiur isotherm shows better fit than Freundlich isotherm in the temperature range studied. The thermodynamic parameters, such as ΔG°, ΔS and ΔH° were calculated. The thermodynamics of dyes–T3K618 system indicates endothermic process.

Keywords: Acid Dyes, Activated Carbon, Activation, Activation Energy, Adsorption, Adsorption Equilibrium, Adsorption Isotherm, Adsorption Process, Adsorption Rates, Agricultural Waste, Aqueous-Solution, Batch, Batch System, BET, BET Surface Area, Capacity, Carbon, Chemical, Chemical Activation, Concentration, Congo Red, Diameter, Diffusion, Diffusion Coefficient, Diffusion Rate, Distribution, Dye Adsorption, Effects, Endothermic, Energy, Equilibrium, Equilibrium Studies, Experimental, Experimental Data, External Mass Transfer, External Mass Transfer Coefficient, Film, Fly-Ash, Freundlich, Freundlich Isotherm, Intraparticle Diffusion, Isotherm, Kinetic, Kinetic Models, Kinetics, Lignite, Malachite Green, Mass Transfer, Mass Transfer Coefficient, Mass-Transfer, Mechanisms, Methylene-Blue, Mg, Model, Models, N₂, N₂ Adsorption, N₂-Adsorption, N₂, Parameters, Pore, Pore Diffusion, Pore Diffusion Coefficient, Pore Size, Pore Size Distribution, Pore Volume, Process, Properties, Range, Rate, Rate Constant, Reaction Kinetics, Rice-Husk, Second Order, Size, Size Distribution, Solid-Waste, Surface, Surface Area, T-Plot, Temperature, Temperatures, Thermodynamic, Thermodynamic Parameters, Thermodynamics, Time, Transfer, Transfer Coefficient, Waste-Water

? Kumar, K.V. and Porkodi, K. (2007), Mass transfer, kinetics and equilibrium studies for the biosorption of methylene blue using Paspalum notatum. Journal of Hazardous Materials,