Personal Research Database

Full Text: 2009\J Haz Mat165, 63.pdf

Abstract: This paper presents the adsorption of Pb(II) from aqueous solution onto Unye (Turkey) bentonite in raw (RB), iron oxide-coated (ICB) and magnesium oxide-coated (MCB) forms. Adsorption of Pb(II) by samples was investigated as a function of the initial Pb(II) concentration, solution pH, ionic strength, temperature and inorganic ligand effect (Cl-). Changes in the surface and structure were characterized by means of XRD and N-2 gas adsorption data. The Langmuir monolayer adsorption capacities of RB, ICB and MCB in 0.1 M KNO3 solution were estimated as 16.70, 22.20 and 31.86 mg/g, respectively. The spontaneity of the adsorption process is established by decrease in Delta G which varied from -21.60 to -28.60 kJ/mol (RB), -21.74 to -32.22 kJ/mol (ICB) and -26.27 to -33.11 (MCB) in temperature range 303-338 K. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Capacities, Adsorption Characteristics, Aqueous Solution, Aqueous-Solution, Bentonite, Clay, Concentration, Copper, Cu(II), Data, Fly-Ash, Forms, Function, Ionic Strength, Ions, Iron, Langmuir, Lead, Lead Ions, Ligand, Magnesium, Manganese Oxide, Metal-Ions, Monolayer, N-2, N₂, Pb(II), pH, Removal, Rights, Solution, Strength, Structure, Surface, Surface Complexation, Temperature, Thermodynamic, Turkey, Waste-Water, XRD

? Khaled, A., El Nemr, A., EI-Sikaily, A. and Abdelwahab, O. (2009), Removal of Direct N Blue-106 from artificial textile dye effluent using activated carbon from orange peel: Adsorption isotherm and kinetic studies. Journal of Hazardous Materials, 165 (1-3), 100-110.

Full Text: 2009\J Haz Mat165, 100.pdf

Abstract: The purpose of this study is to suggest an efficient process. which does not require a huge investment for the removal of direct dye from wastewater. Activated Carbon developed from agricultural waste material was characterized and utilized for the removal of Direct Navy Blue 106 (DNB-106) from wastewater. Systematic studies on DNB-106 adsorption equilibrium and kinetics by low-cost activated carbons were carried out. Adsorption Studies were carried out at different initial concentrations of DNB-106 (50, 75, 100, 125 and 150 mgl^-1), contact time (5-180 min), pH (2.0, 3.0, 4.7, 6.3, 7.2, 8.0, 10.3 and 12.7) and sorbent doses (2.0, 4.0 and 6.0 g l^-1). Both Langmuir and Freundlich models fitted the adsorption data quite reasonably (R-2 > 97). The maximum adsorption capacity was 107.53 mg g^-1 for 150 mg l^-1 of DNB-106 concentration and 2 g l^-1 carbon concentration. Various mechanisms were established for DNB-106 adsorption on developed adsorbents. The kinetic studies were conducted to delineate the effect of initial dye concentration, contact time and solid to liquid concentration. The developed carbon might be successfully used for the removal of DNB-106 from liquid industrial wastes. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorption, Agricultural Solid-Waste, Alga Ulva-Lactuca, Aqueous-Solution, Cancer Risk, Coir Pith, Direct N Blue-106, Equilibrium, Green, Isotherm, Kinetics, Methylene-Blue, Orange Peel, Tree Fern, Wastewater

? Akar, S.T., Gorgulu, A., Anilan, B., Kaynak, Z. and Akar, T. (2009), Investigation of the biosorption characteristics of Lead(II) ions onto Symphoricarpus albus: Batch and dynamic flow studies. Journal of Hazardous Materials, 165 (1-3), 126-133.

Full Text: 2009\J Haz Mat165, 126.pdf

Abstract: This work reports the results of the study for Lead(II) binding by the natural and low cost biosorbent Symphoricarpus albus. Batch biosorption experiments demonstrated the high rate of Lead(II) biosorption and the kinetic data were successfully described by a pseudo-second-order model. Biosorption of Lead(II) onto S. albus biomass showed a pH-dependent profile and Lead(II) biosorption was higher when pH or temperature was increased. As much as 88.5% removal of Lead(II) is also possible in the multi-metal mixture. The Langmuir isotherm better fits the biosorption data and the monolayer biosorption capacity was 3.0010^-4 mol g^-1 at 45 C. The biomass was characterized with FTIR and SEM analysis. Desorption studies revealed that the natural biomass could be regenerated using 10 mM HNO₃ solution with about 99% recovery and reused in five biosorption-desorption cycles. Therefore, S. albus which is cheap, highly selective and easily regenerable seems to be a promising substrate to entrap Lead(II) ions in aqueous solutions. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aqueous-Solution, Biosorption, Cd(II), Column, Cu(II) Ions, Desorption, Equilibrium, Heavy-Metal Removal, Langmuir, Lead(II), Mechanism, Natural Biomass, Pb(II), pH, Textile Dye, Waste Biomass

? Chang, P.H., Li, Z.H., Yu, T.L., Munkhbayer, S., Kuo, T.H., Hung, Y.C., Jean, J.S. and Lin, K.H. (2009), Sorptive removal of tetracycline from water by palygorskite. Journal of Hazardous Materials, 165 (1-3), 148-155.

Full Text: 2009\J Haz Mat165, 148.pdf

Abstract: Extensive use of pharmaceuticals and growth hormone in farm animal and live stocks has resulted in their frequent detection in soils, groundwater, and wastewater. The fate and transport of these compounds are strongly affected by their sorptive behavior to the soil minerals and humic materials. In this research, we conducted the sorption of tetracycline (TC), a common antibiotic, on palygorskite (PFL-1), a fibrous clay mineral of high surface area and high sorptivity towards organic compounds. The results showed that the sorption capacity of TC on PFL-1 was as high as 210 mmol/kg at pH 8.7. The sorption was relatively fast and reached equilibrium in 2 h. Solution pH and ionic strength had significant effects on TC sorption. The sorption of TC by palygorskite is endothermic and the free energy of sorption is in the range of -10 to -30 kJ/mol, suggesting a strong physical sorption. The X-ray diffraction patterns before and after TC sorption revealed no changes in d-spacing and intensity under different pH and initial TC concentrations, indicating that the sorbed TC molecules are on the external surface of the mineral in contrast to intercalation of TC into swelling clays, such as montmorillonite. The small positive value of entropy change suggested that TC molecules are in disordered arrangement on palygorskite surfaces. Surface sorption of TC on PFL-1 is further supported by the derivative of gravimetric analysis and by the calculation of the amount of TC sorption normalized to the surface area. The results suggest that palygorskite Could be a good candidate to remove TC from wastewater containing higher amounts of TC. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aqueous-Solution, Base-Line, Cation-Exchange, Clay, Heavy-Metals, Minerals, Palygorskite, Pharmaceutical, Raman-Spectra, Sepiolite, Society Source Clays, Sorption, Tetracycline, Thermal-Analysis

? Zhang, J., Xie, S.D. and Ho, Y.S. (2009), Removal of fluoride ions from aqueous solution using modified attapulgite as adsorbent. Journal of Hazardous Materials, 165 (1-3), 218-222.

Full Text: 2009\J Haz Mat-Ho.pdf; 2009\J Haz Mat-Ho2.pdf; 2009\J Haz Mat165, 218.pdf

Abstract: Adsorption of fluoride ions from water using modified attapulgite with magnesium and aluminum salts was conducted by batch experiments. The effects of temperatures and mass ratios of attapulgite, magnesium and aluminum salts were investigated. Linear and non-linear methods were applied for fitting the adsorption data with Langmuir, Freundlich, and Redlich-Peterson isotherms. Modified attapulgite with a mass ratio attapulgite: MgCl₂·6H₂O:AlCl₃·2H₂O = 2:1:2 had higher fluoride adsorption capacity. In addition, the fluoride adsorption using the modified attapulgite included an anion exchange process.

Keywords: Fluorosis, Attapulgite, Modification, Isotherm, Sorption, Anion Exchange

? Chen, H. and Wang, A.Q. (2009), Adsorption characteristics of Cu(II) from aqueous solution onto poly(acrylamide)/attapulgite composite. Journal of Hazardous Materials, 165 (1-3), 223-231.

Full Text: 2009\J Haz Mat165, 223.pdf

Abstract: Batch adsorption experiments were carried out to remove Cu(II) ions from its aqueous Solutions using a poly(acrylamide)/attapulgite composite. The different parameters effecting on the adsorption capacity such as contact time, initial metal ion concentration, temperature and pH of the solution have been investigated. The adsorption kinetic experiments revealed that there are three stages in the whole adsorption process. It was found that Cu(II) adsorption onto the composite followed pseudo-second-order kinetics and were mainly controlled by the film diffusion mechanism, along with a considerable contribution of the intra-particle diffusion mechanism. Analysis of adsorption results obtained at different temperatures showed that the adsorption pattern on the composite well followed the Langmuir, Freundlih and D-R isotherms, and the characteristic parameters for each adsorption isotherm were also determined. The adsorption process has been found endothermic in nature and thermodynamic parameters have been Calculated. The analysis for variations of IR spectra and the values of the mean free energies of adsorption (E,) demonstrated that the chelation model should be the dominating adsorption mechanism. The species of copper salts can affect the adsorption capacity of the composite, which are in the order of CuSO₄ > CuCl₂ > Cu(NO₃)₂ >> Cu(CH₃COO)₂. (C) 2008 Published by Elsevier B.V.

Keywords: Adsorption, Adsorption Isotherm, Carbons, Composite, Cu(II), Equilibrium, Heavy-Metals, Hydrogels, Intra-Particle Diffusion, Isotherms, Kinetics, Langmuir, Palygorskite, pH, Poly(Sodium Acrylate), Removal, Superabsorbent Composite, Thermodynamic Parameters, Waste-Water, Water Absorbency

? Yao, L., Ye, Z.F., Tong, M.P., Lai, P. and Ni, J.R. (2009), Removal of Cr³⁺ from aqueous solution by biosorption with aerobic granules. Journal of Hazardous Materials, 165 (1-3), 250-255.

Full Text: 2009\J Haz Mat165, 250.pdf

Abstract: Aerobic granules were utilized as an effective biosorbent to remove Cr³⁺ from aqueous solution. The results showed that the initial pH, contact time, and Cr³⁺ concentration affected the biosorption process significantly. Both Freundlich and Langmuir isotherms were able to describe the equilibrium data reasonably with high correlation coefficients (R^-2 > 0.95) and pseudo-second-order model best fitted the biosorption process at experimental conditions. Moreover, Environmental Scanning Electronic microscope (ESEM), X-ray energy dispersion (EDX), and Fourier transform infrared (FTIR) analyses revealed that metal complexation, chemical precipitation, and ion exchange were involved in the removal of Cr³⁺ with aerobic granules. Further analysis by a metal ion fraction test demonstrated that metal complexation could be the dominant mechanism of biosorption, whereas chemical precipitation and ion exchange appeared only to have minor role in the overall Cr³⁺ biosorption process. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Aerobic Granules, Biomass, Biosorprion, Cr(III), Cr³⁺, Equilibrium, Esem, Green, Heavy-Metals, Langmuir, Metal Ion Fraction, Pb(II), pH, Removal, Sequential Extraction, Sludge, Sorption, Waste-Water Treatment

? Bhattacharyya, K.G., Sarma, J. and Sarma, A. (2009), Azadirachta indica leaf powder as a biosorbent for Ni(II) in aqueous medium. Journal of Hazardous Materials, 165 (1-3), 271-278.

Full Text: 2009\J Haz Mat165, 271.pdf

Abstract: Azadirachta indica leaves are converted to a fine powder for use as a biosorbent for the removal of metal ions in aqueous solution. In this work, the adsorptive interactions between Ni(II) and the powder were studied under a variety of conditions involving variations in pH, Ni(II) concentration, biosorbent amount, interaction time and temperature, all in single batch processes. The experimental data have been interpreted on the basis of existing mathematical models of equilibrium kinetics and thermodynamics. The biosorption of Ni(II) increased in the pH range of 2.0-5.0 with similar to 92.6% adsorption at pH 5.0 for the highest amount of the biosorbent (4 g/L). The biosorption followed second-order kinetics and intra-particle diffusion was likely to have significant influence in controlling the process. The Langmuir monolayer adsorption capacity varied from 2.4 to 9.1 mg/g and the equilibrium coefficient from 1.09 to 2.78 L/g with strong indication that the Ni(II) ions were field on the biosorbent Surface by formation of an adsorption complex. The thermodynamic parameters showed the process to be exothermic in nature supported by appropriate ranges of values of enthalpy change, entropy change and Gibbs energy change. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption, Azadirachta Indica Leaf Powder, Binding, Biomass, Biosorption, Biosorption, Cu(II), Heavy-Metal Ions, Intra-Particle Diffusion, Isotherm, Kinetics, Peat, Removal, Sorption, Thermodynamics

? Caner, N., Kiran, I., Ilhan, S. and Iscen, C.F. (2009), Isotherm and kinetic studies of Burazol Blue ED dye biosorption by dried anaerobic sludge. Journal of Hazardous Materials, 165 (1-3), 279-284.

Full Text: 2009\J Haz Mat165, 279.pdf

Abstract: Biosorption potential of dried anaerobic sludge (DAS) for Burazol Blue ED (BB) was studied with respect to pH, equilibrium time, initial dye concentrations and temperature to determine equilibrium and kinetic models. The most suitable pH, equilibrium time and initial dye concentration were determined as 0.5±0.03, 75 min and 150 mg/L, respectively, at a biomass dosage of 0.4 g/L and 25C±1.0. The equilibrium data was best described by the Langmuir isotherm model. Maximum uptake capacity (q_m) of DAS for the dyestuff (BB) were 118.3, 125.8 and 127.5 mg/g biomass at temperatures of 25, 40 and 50C. respectively, indicating that the biosorption process is spontaneous and favored at higher temperatures. The overall biosorption process was best described by pseudo-second-order kinetic model. Gibbs free energy changes were Calculated as -356.8, -519.7 and -520.6 J/mol at 25, 40 and 50C, respectively. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated-Sludge, Adsorption, Anaerobic Sludge, Aqueous-Solution, Biomass, Biosorption, Burazol Blue Ed, Carbons, Desorption, Equilibrium, Isotherms, Kinetics, Langmuir, Mechanism, Methylene-Blue, pH, Removal

? Deng, S.B., Ma, R., Yu, Q., Huang, J. and Yu, G. (2009), Enhanced removal of pentachlorophenol and 2,4-D from aqueous solution by an aminated biosorbent. Journal of Hazardous Materials, 165 (1-3), 408-414.

Full Text: 2009\J Haz Mat165, 408.pdf

Abstract: The fungal biomasses of Penicillium chrysogenum were used as raw materials to prepare the aminated adsorbent through chemical grafting of polyethylenimine (PEI) on the biomass surface. Due to the protonation of amine groups, the PEI-modified biomass was found to possess the zero point of zeta potential at pH 10.2, higher than the pristine biomass at pH 3.8. The aminated biosorbent was effective in removing anionic pentachlorophenol (PCP) and 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solution. The sorption was pH-dependent and the sorption kinetic data were well described by the pseudo-second-order model. The sorption isotherms on the aminated biosorbent conformed to the Langmuir equation, with the maximum sorption capacity of 1.23 mmol/g for PCP and 1.22 mmol/g for 2,4-D. In the presence of Cu²⁺ or Pb²⁺, the sorption capacities for both PCP and 2,4-D were further enhanced, attributed to the formation of surface complex. FTIR and zeta potential analysis before and after the sorption revealed that the amine groups on the biomass surface played an important role in the sorption of PCP and 2,4-D, due to the electrostatic interaction between the positive protonated amine groups and the negative PCP/2.4-D. (C) 2008 Elsevier B.V. All Fights reserved.

Keywords: 2,4-Dichlorophenol, Adsorption, Anionic Adsorbate, Biosorption, Chlorophenols, Electrostatic Interaction, Fungal Biomass, Heavy-Metals, Kinetics, Langmuir, Pei, Pei-Modified Adsorbent, pH, Sorption, Sorption Behavior, Sorption Mechanism, Waste

? Gavilan, K.C., Pestov, A.V., Garcia, H.M., Yatluk, Y., Roussy, J. and Guibal, E. (2009), Mercury sorption on a thiocarbamoyl derivative of chitosan. Journal of Hazardous Materials, 165 (1-3), 415-426.

Full Text: 2009\J Haz Mat165, 415.pdf

Abstract: The grafting of thiourea on chitosan backbone allows synthesizing a thiocarbamoyl derivative that was very efficient for mercury sorption in acidic solutions. Though the sorption capacity is not increased compared to raw chitosan in near neutral solutions, this modification allowed maintaining high sorption capacity (close to 2.3 mmol Hg g^-1) at pH 2. Mercury sorption in acidic solutions is not affected by the presence of competitor metals (such as Zn(II), Pb(II), Cu(II), Cd(II), Ni(II)) or the presence of nitrate anions (even at concentration as high as 0.8 M)). The presence of chloride or sulfate anions (0.8 M) decreased Hg(II) sorption capacity to 1 mmol Hg g^-1. Kinetics are controlled by a combination of pseudo second-order reaction rate and resistance to intraparticle diffusion. Mercury desorption reached about 75% using thiourea (in HCl solution). (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Aqueous-Solutions, Cadmium Sorption, Chitosan, Competition, Cross-Linked Chitosan, Cu(II), Hydrochloric-Acid, Impregnated Macroporous Resins, Kinetics, Mercury, Metal-Ions, Palladium Sorption, Particle Diffusion Kinetics, pH, Selective Adsorption, Sorption Isotherms, Thiocarbamoylation, Uptake Kinetics

? Yao, R.H., Meng, F.P., Zhang, L.J., Ma, D.D. and Wang, M.L. (2009), Defluoridation of water using neodymium-modified chitosan. Journal of Hazardous Materials, 165 (1-3), 454-460.

Full Text: 2009\J Haz Mat165, 454.pdf

Abstract: The water containing high fluoride ions could do harm to human and environment. In this work, the applicability of neodymium-modified chitosan as adsorbents for the removal of excess fluoride ions from water was studied. The effect of various physico-chemical parameters such as temperature (283-323 K), pH (5-9), adsorbent dose (0.2-2.0 g L^-1), particle size (0.10-0.50 mm) and the presence of co-anions (NO₃^-, Cl^- and SO₄^2-) on removal of fluoride ions were studied. The equilibrium sorption data were fitted reasonably well for Langmuir isotherm model, the maximum equilibrium sorption had found to be 11.411-22.380 mg g^-1. Sorption dynamics study revealed that the pseudo-second-order was suitable to describe the kinetics process of fluoride ions sorption onto the adsorbent with the initial sorption rate 1.70, 2.10 and 2.67 mg g^-1 min^-1 at 283, 303 and 323 K, and the sorption process was complex, both the boundary of liquid film and intra-particle diffusion contributed to the rate-determining step. The used adsorbents could be regenerated in 24 h by 4g L^-1 of sodium hydroxide. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.

Keywords: Adsorption, Alumina, Aqueous-Solutions, Chitosan, Defluoridation, Drinking-Water, Equilibrium, Fluoride Removal, Intra-Particle Diffusion, Langmuir, Neodymium, pH, Sorption, Sorption

? Li, X.N., Xu, Q.Y., Han, G.M., Zhu, W.Q., Chen, Z.H., He, X.B. and Tian, X.J. (2009), Equilibrium and kinetic studies of copper(II) removal by three species of dead fungal biomasses. Journal of Hazardous Materials, 165 (1-3), 469-474.

Full Text: 2009\J Haz Mat165, 469.pdf

Abstract: The batch experiments were conducted to study the copper(II) removal by formaldehyde inactivated Cladosporium cladosporioides, Gliomastix murorum and Bjerkandera sp., at conditions of agitation speed of 150 rpm, temperature of 25C, biosorbent dose of 2 g l^-1 and contact time of 12 h. It was found that, for each biomass, the optimum pH was 6.0 and the equilibrium establishing time was about 2 h. Without acid or alkali treatment for improving adsorption properties, the experimental maximum copper(H) biosorptions were relatively high: 7.74 mg g^-1 for C. cladosporioides, 9.01 mg g^-1 for G. murorum, and 12.08 mg g^-1 for Bjerkandera sp.. The biosorption data of all the dead fungal biomasses were quite fitted to Langmuir isotherm model and pseudo second-order kinetic model; first-order Lagergren kinetic model gave good adjustment to the data of Bjerkandera sp. but did not fit the data of C. cladosporioides and G. murorum very well. These fungal biomasses exhibited relatively high capacity for the removal of copper(II) from aqueous solutions. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Isotherm, Aqueous-Solutions, Aspergillus-Niger, Biosorption, Biosorption, By-Products, Copper, Dead Fungal Biomass, Heavy-Metal Ions, Kinetics, Langmuir, Pb(II), Phanerochaete-chrysosporium, Rhizopus-arrhizus, Saccharomyces-cerevisiae

? Tuzen, M., Sari, A., Mendil, D., Uluozlu, O.D., Soylak, M. and Dogan, M. (2009), Characterization of biosorption process of As(III) on green algae Ulothrix cylindricum. Journal of Hazardous Materials, 165 (1-3), 566-572.

Full Text: 2009\J Haz Mat165, 566.pdf

Abstract: Arsenic (As) is generally found as As(III) and As(V) in environmental samples. Toxicity of As(III) is higher than As(V). This paper presents the characteristics of As(III) biosorption from aqueous solution using the green algae (Ulothrix cylindricum) biomass as a function of pH, biomass dosage, contact time, and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of As(III) by U. cylindricum biomass. The biosorption capacity of U. cylindricum biomass was found as 67.2 mg/g. The metal ions were desorbed from U. cylindricum using 1 M HCl. The high stability of U. cylindricum permitted 10 times of adsorption-elution process along the studies with a slightly decrease about 16% in recovery of As(III) ions. The mean free energy value evaluated from the D-R model indicated that the biosorption of As(III) onto U. cylindricum biomass was taken place by chemical ion-exchange. The calculated thermodynamic parameters, G°, H° and S° showed that the biosorption of As(III) onto U. cylindricum biomass was feasible, spontaneous and exothermic under examined conditions. Experimental data were also tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. The results showed that the biosorption processes of As(III) followed well pseudo-second-order kinetics. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Alumina, Adsorption Characteristics, Aqueous-Solution, Arsenic Removal, As(III), Biomass, Biosorption, Chelating Resin, Drinking-Water, Green Algae, Langmuir, Marine-Algae, Metal-Ions, pH, Sorption, Thermodynamic Parameters, U.Cylindricum

? Al-Ghouti, M.A., Khraisheh, M.A.M., Ahmad, M.N.M. and Allen, S. (2009), Adsorption behaviour of methylene blue onto Jordanian diatomite: A kinetic study. Journal of Hazardous Materials, 165 (1-3), 589-598.

Full Text: 2009\J Haz Mat165, 589.pdf

Abstract: The effect of initial concentration, particle size, mass of the adsorbent. pH and agitation speed oil adsorption behaviour of methylene blue (MB) onto Jordanian diatomite has been investigated. The maximum adsorption capacity, q, increased from 75 to 105 mg/g when pH of the dye solution increased from 4 to 11. It is clear that the ionisable charge sites on the diatomite surface increased when pH increased from 4 to 11. When the solution pH was above the pH(ZPC), the diatomite surface had a negative charge, while at low pH (pH < 5.4) it has a positive charge. The adsorption capacity increased from 88.6 to 143.3 mg/g as the initial MB concentrations increased from 89.6 to 225.2 mg/dm(3). The experimental results were also applied to the pseudo-first and -second order kinetic models. It is noticed that the whole experimental data of MB adsorption onto diatomite did not follow the pseudo-first order model and had low correlation coefficients (R-2 < 0.3). The calculated adsorption capacity, q(e,cal), values obtained from pseudo-first order kinetic model did not give acceptable value, q(e,exp). The maximum uptake capacity seems to be independent of the particle size of the diatomite when the particle size distribution is less than 250-500 mu m. While at larger particle size 250-500 mu m, the maximum uptake capacity was dependent on the particle size. It would imply that the MB adsorption is limited by the external surface and that intraparticle diffusion is reduced. The effect of the agitation speeds oil the removal of MB from aqueous solution using the diatomite is quite low. The MB removal increased from 43 to 100% when mass of the diatomite increased from 0.3 to 1.7 g. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Acid Dye, Activated Carbons, Adsorption, Aqueous-Solution, Bone Char, Cadmium Ions, Diatomite, Equilibrium, Kinetic Studies, Methylene Blue, Natural Adsorbents, pH, Reactive Dye, Removal, Sorption, Waste Treatment

? El-Sofany, E.A., Zaher, W.F. and Aly, H.F. (2009), Sorption potential of impregnated charcoal for removal of heavy metals from phosphoric acid. Journal of Hazardous Materials,