Batch Equilibrium and Kinetics Studies of Cd (II) Ion Removal from Aqueous Solution Using Porous Chitosan Hydrogel Beads

Document Type: Research Article

Authors

1 Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, I.R. IRAN

2 Biochemical and Bioenvironmental Engineering Research Centre (BBRC), Sharif University of Technology, Tehran, I.R. IRAN

3 Biotechnology Group, Chemical Engineering Department, Trbiat Modares University, Tehran, I.R. IRAN

Abstract

In this study chitosan hydrogel beads with porosity ~ 0.86 and diameter ~ 20.07 mm were prepared from 85 % deacetylated chitosan for removal of Cd2+ ions from aqueous solutions.  Chitosan powder was dissolved into dilute acetic acid as solvent and formed into spherical beads using a phase inversion technique. The effect of temperature, initial concentration of Cd2+ ions, and the period of agitation were perused to achieve the best isotherm model. Freundlich model was better fitted than Langmuir model (R2 > 0.99 and R2> 0.93 respectively, at pH of 6.3, and shaker speed of 200 rpm), the constants of Langmuir and Freundlich models were calculated, which RL value and qmax (mg/g wet weight) at 30 °C, 40 °C, 50 °C showed maximum uptake capacity of 61.35 (mg/g wet weight) obtained at 30 °C. The calculated heat of adsorption was -8.69,-7.051, -5.513 kJ mol-1 at 30, 40, 50 °C respectively which verified an exothermic process. Kinetic studies of the adsorption phenomena were conducted in a batch system by initial concentrations from 100 to 500 mgL-1 until the equilibrium concentration Ce (mgL-1) was reached. First-order, and second-order kinetic models were used; the experimental data were in reliable compliance with second-order kinetic model with R2 value greater than 0.97. The rate constants of the kinetic models were also calculated and tabulated. To investigate the surface morphology of the chitosan beads before and after adsorption process, they were observed by the use of Scanning Electron Microscopy (SEM). The surface characterization of the beads in both cases showed metal ions binding toward the surface of porous chitosan beads. All of the experiments carried out at pH of 6.3 and agitation rate of 200 rpm, which were opted according to optimum status of previous researcher’s reports.

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[1] Yin, P., Yu, Q., Jin, B., Ling, Z., Biosorption Removal of Cadmium from Aqueous Solution by using Pretreated Fungal Biomass Cultured from Starch Wastewater, J. Water Res., 33, 1960 (1999).
[2] Wan Ngah,  W.S.,  Endud,  C.S.,  Mayanar,  R., Removal of Copper (II) Ions from Aqueous Solution onto Chitosan and Cross-Linked Chitosan Beads, Reactive and Func. Polym., 50, 181 (2002).
[3] Wan Ngah,  W.S.,  Ghani,  S.A.,  Kamari,  A., Adsorption Behavior of Fe (II) and Fe (III) Ions in Aqueous Solution on Chitosan and Cross-Linked Chitosan Beads, Biores. Technol., 96, 443  (2005).
[4] Maghsoodi,V. et al., Influence of Different Nitrogen Sources on Amount of Chitosan Production by Aspergillus nigerin Solid State Fermentation, Iran. J. Chem. Chem. Eng., 27 (1), (2008).
[5] Harish Prashanth, K.V., Tharanathan R.N., Chitin/ Chitosan: Modifications and Their Unlimited Application Potential-an Overview, Trends in Food Sci. & Technol., 17, 1 (2006).
[6] Guibal E., Interactions of Metal Ions with Chitosan-Based Sorbents: A Review, Sep. and Purification Technol., 38, 43 (2004).
[7] Trimukhe,  K.D.,  Varma, A.J., A Morphological Study of Heavy Metal Complexes of Chitosan and Crosslinked Chitosans by SEM and WAXRD, Carbohyd. Polym., 62 (1), 57 (2005).
[8] Zhao,  F., Yu,  B., Yue, Z., Wang, T., Wen, X., Liu, Z., Zhao, C., Preparation of Porous Chitosan Gel Beads for Copper (II) Ion Adsorption, J. of Hazard. Mater., 147, 67 (2007).
[9] Wan Ngah, W.S., Kamari, A., Koay, Y.J., Equilibrium and Kinetics Studies of Adsorption of Copper (II) on Chitosan and Chitosan/PVA Beads, Int. J. of Biol. Macromolecules, 34, 155 (2004).
[10] Cestari, A.R., Vieira, E.F.S., Oliveira, I.A.D., Bruns R.E., The Removal of Cu (II) and Co (II) from Aqueous Solutions using Cross-Linked Chitosan-Evaluation by the Factorial Design Methodology, Biotechnol. and Bioeng., 50, 207 (1996).
[11] Jeon, C., Park, K.H., Adsorption and Desorption Characteristics of Mercury (II) Ions using Aminated Chitosan Bead, J. Water Res., 39, 3938 (2005).
[12] Baroni, P., Vieira, R.S., Meneghetti, E., Dasilva, M.G.C., Beppu, M.M., Evaluation of Batch Adsorption of Chromium Ions on Natural and Crosslinked Chitosan Membranes, J. of Hazard. Mater., 152 (3), 1155 (2008).
[13] Chilton, N.G., Losso, J.N., Marshall Wayne, E., Rao Ramu, M., Freundlich Adsorption Isotherms of Agricultural By-Product-Based Powdered Activated Carbons in a Geosmin-Water System, Biores. Technol., 85, 131 (2002).
[14] Donia, A.M., Atia, A.A., Elwakeel, K.Z., Recovery of Gold (III) and Silver (I) on a Chemically Modified Chitosan with Magnetic Properties, J. Hydrometallurgy, 87, 197 (2007).