Adsorption and desorption of Cu(II), Cd(II) and Pb(II) ions using chitosan crosslinked with epichlorohydrin-triphosphate as the adsorbent

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• 作者：Rogé ; rio Laus ; Thiago G. Costa ; Bruno Szpoganicz ; Valfredo T. Fá ; vere
• 关键词：Chitosan ; Epichlorohydrin ; Triphosphate ; Adsorption ; Desorption
• 刊名：Journal of Hazardous Materials
• 出版年：2010
• 出版时间：15 November 2010
• 年：2010
• 卷：183
• 期：1-3
• 页码：233-241
• 全文大小：405 K

文摘

In this study, chitosan (CTS) was crosslinked with both epichlorohydrin (ECH) and triphosphate (TPP), by covalent and ionic crosslinking, respectively. The resulting new CTS–ECH–TPP adsorbent was characterized by CHN analysis, EDS, FTIR spectroscopy, TGA and DSC, and the adsorption and desorption of Cu(II), Cd(II) and Pb(II) ions in aqueous solution were investigated. Potentiometric studies were also performed and revealed three titratable protons for each pK_a value of 5.14, 6.76 and 9.08. The results obtained showed that the optimum pH values for adsorption were 6.0 for Cu(II), 7.0 for Cd(II) and 5.0 for Pb(II). The kinetics study demonstrated that the adsorption process proceeded according to the pseudo-second-order model. Three isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich) were employed in the analysis of the adsorption equilibrium data. The Langmuir model resulted in the best fit and the new adsorbent had maximum adsorption capacities for Cu(II), Cd(II) and Pb(II) ions of 130.72, 83.75 and 166.94 mg g⁻¹, respectively. Desorption studies revealed that HNO₃ and HCl were the best eluents for desorption of Cu(II), Cd(II) and Pb(II) ions from the crosslinked chitosan.