The characteristics and mechanism of Co(II) removal from aqueous solution by a novel xanthate-modified magnetic chitosan

A novel xanthate-modified magnetic chitosan (XMCS) was prepared, characterized and applied for Co(II) removal from aqueous solution, and compared with magnetic chitosan (MCS). The characteristics and mechanism of Co(II) sorption was investigated. The experimental results showed that the introduction of thiol group on magnetic chitosan greatly increased the adsorption capacity for Co(II). The kinetics of Co(II) sorption could be described by pseudo second-order equation, and the adsorption isotherm followed the Langmuir model for both MCS and XMCS. The maximum adsorption capacity was found to be 18.5 mg/g and 2.98 mg/g, respectively from the Langmuir isotherm for XMCS and MCS. The mechanism of Co(II) adsorption onto XMCS was tentatively proposed through FTIR and XPS analysis. (C) 2011 Elsevier B.V. All rights reserved.