Kinetics of Chromium Ion Removal from Tannery Wastes Using Amberlite IRA-400 Cl− and its Hybrids

Abstract

A strong base anion exchange resin Amberlite IRA-400 Cl− and its hybrids with Mn(OH)2 and Cu(OH)2 are used for the removal of chromium from the synthetic spent tannery bath. The recovery is examined by varying the experimental conditions, viz., resin dosage, stirring speed, and temperature. The rate of chromium removal by Amberlite IRA-400 Cl− increased almost four times when the resin dosage was increased from 0.2 to 1.0 g. Furthermore, the rate of chromium sorption almost doubled when the stirring speed was increased from 100 to 1,000 rpm, suggesting that the sorption is a diffusionally controlled process. The chromium removal capacity also increased with the rise of temperature, showing the endothermic nature of the process. The results are explained with the help of film diffusion, particle diffusion, and Lagergren pseudo-first-order kinetic models. The kinetics results of the Amberlite IRA-400 Cl− are compared with its hybrid anion exchange resins IRA-400 Mn(OH)2 and IRA-400 Cu(OH)2. It is found that the hybrid ion exchangers have greater removal ability and fast kinetics as compared to the parent exchanger.