Selective adsorption of Co2+ and Mn2+ by cobalt/manganese imprinted thiourea-chitosan

Abstract

A cobalt/manganese-imprinted adsorbent grafted with thiourea (T-Co/Mn-CTS) was synthesized through the combination of the amino groups of thiourea with imprinted chitosan (Co/Mn-CTS) by using a sol-gel method along with a reverse-phase suspension method. Cobalt chloride and manganese chloride were employed as imprint molecules. The structures of the adsorbents were investigated by Fourier transform infrared spectroscopy. The results of static adsorption experiments indicated that the adsorption of Co2+ and Mn2+ occurred in the first 0.5 h, and the absorption capacity of T-Co/Mn-CTS for these ions was higher than that of Co/Mn-CTS. The selective adsorption performance of the template-imprinted-chitosan resin was better than that of the non-imprinted-chitosan resin, in the presence of other ions. The effect of interfering ions on the adsorption performance for Mn2+ was greater than that for Co2+. Dynamic adsorption experiments indicated that the breakthrough volumes of Co2+ and Mn2+ were 110 BV and 14 BV, respectively, with the corresponding breakthrough curves being symmetrical S-type and unsymmetrical S-type.

Keywords

• chitosan
• imprint
• thiourea
• selective adsorption