Efficient adsorption of Ag(Ⅰ) and Au(Ⅲ) on modified magnetic chitosan with amine functionalities

摘要

Sodium tripolyphosphate (TPP) crosslinked magnetic chitosan adsorbent was prepared and immobilized with pentamine moieties. The adsorption behavior of the prepared adsorbent toward Ag(Ⅰ) and Au(Ⅲ) was studied at different experimental condition using batch and column methods. The maximum adsorption capacity was found to be 1.7 and 2.3 mmolg~(-1) for Ag(Ⅰ) and Au(Ⅲ), respectively. The mechanism of interaction between metal ion and adsorbent was found to proceed via complex formation and/or ion exchange. Kinetics and thermodynamic studies showed that the adsorption followed pseudo-second order with endothermic nature. The regeneration of the loaded resin was performed using 1.0 M acidified thiourea and was found to be 95-97%. The flow rate of l.0mLmin~(-1) in column experiments was found to be the most preferable rate.