Adsorption kinetics and modeling of gadolinium and cobalt ions sorption by an ion-exchange resin

In this work, the removal of gadolinium and cobalt ions using Dowex HCR-S/S resin was studied. Batch-mode kinetic and equilibrium studies have been carried out. The effect of solution pH, shaking time, initial metal ion concentrations, resin dosage and temperature has been investigated. Equilibrium data were analyzed by sorption isotherm models. The results of sorption experiments indicate that the monolayer capacities of Gd(III) and Co(II) at equilibrium are 66.0 and 69.4 mg/g, respectively. The results of kinetic models showed that the pseudo-second-order kinetic model was found to correlate with the experimental data well. It was found that the amount of ions sorbed onto the resin increased with increasing temperature; this indicates the endothermic nature of the sorption process. It was concluded that resin has an efficient sorption capacity compared to many sorbents.