Modified Alginate Beads as Biosensor and Biosorbent for Simultaneous Detection and Removal of Cobalt Ions from Aqueous Solution

摘要

A novel biomaterial was prepared to simultaneously detect and remove cobalt ions from aqueous solution by modifying alginate (AG) polymer with a high selectivity and sensitive indicator for Co~2+, 4-(5-chloro-2-pyridylazo)-l,3-phenylene-diamine (5-Cl-PADAB). The analysis of FT-IR spectra proved that 5-Cl-PADAB was covalently connected to AG. The modified AG beads can effectively adsorb Co~2+ and indicate the presence of Co~2+ in aqueous solution. After adsorption of Co~2+, the color of the modified AG beads changed from yellow to pink, resulting in a noticeable change, which can be observed by naked eyes. The adsorption of Co~2+ by the modified AG beads can be described by pseudo second-order kinetic model and the Freundlich isotherm model. The AG bead modified with an indicator is a promising biosensor and biosorbent for simultaneous detection and removal of cobalt ions from aqueous solution.