Evaluation of Amberlite IRA96 and Dowex 1 x 8 ion-exchange resins for the removal of Cr(VI) from aqueous solution

The removal of Cr(VI) from aqueous solution by two commercially available resins (Amberlite IRA96 and Dowex 1 x 8) was investigated. Batch adsorption processes were carried out as a function of time, adsorbent dosage, pH and temperature to evaluate the performance of the resins. The optimum pH for Cr(VI) adsorption was found as 3.0 for these resins. It was found that more than 93% removal was achieved under optimal conditions. The maximum adsorption capacities are 0.46 and 0.54 mmolig of Amberlite IRA96 and Dowex 1 x 8 resin for Cr(VI) ion, respectively. The suitability of Freundlich and Langmuir adsorption models were investigated for Cr(VI)-resin equilibrium. A pseudo-second order kinetic model has been proposed to correlate the experimental data. The equilibrium adsorption level for Dowex 1 x 8 decreased with increasing temperature, while it increased for Amberlite IRA96. (C) 2010 Elsevier B.V. All rights reserved.