Adsorption of Pd and Pt on Chemically Modified Chitosan

Abstract

Chitosan is a polymer which consists of D-glucosamine with β-（1,4）bond, and is generally produced by the deacetylation of chitin. Chitin is a main component of the outer shell of shrimp and crab, and are typical waste marine resources. We have paid attention to the effective utilization of such waste marine resources. In this study, a chitosan derivative with pyridine group was synthesized. Using the chitosan derivative, the adsorption characteristics of Pd（Ⅱ）and Pt（Ⅳ）ions were studied. Firstly, chitosan was crosslinked with ethylene glycol diglycidyl ether. This resin is called CLC. CLC was further modified by picolinaldehyde, which is called IPC. IPC was then reduced by means of sodium borohydride to finally obtain the resin called APC. Using APC, adsorption and desorption of the metals was carried out by means of a batch method and column test. From the metal adsorption experiment, it was found that APC was a superior resin for Pd（Ⅱ）and Pt（Ⅳ）and the order of adsorption ability was Pd（Ⅱ）＞ Pt（Ⅳ）. The adsorption behavior was explained well by the Langmuir adsorption isotherm. Column test using APC showed that Pd（Ⅱ）and Pt（Ⅳ）were successfully separated from each other by the column packed with APC.