Iodide adsorption from aqueous solutions using zirconium-containing anion exchange resin as an oxidizing resin: batch and column studies

Abstract

In the current study, a zirconium-containing anion exchange resin was synthesized as an oxidizing resin for iodide adsorption from aqueous solutions. The static adsorption capacity of the oxidizing resin was 612.86 mg/g (obtained from isotherm studies and the Langmuir model). This capacity was 31% higher than the capacity of counter parent resin for iodide adsorption. Adsorption performance of the oxidizing resin was close to maximal over a wide range of pHs (2–7), and the best results were obtained at pH = 3 (8.5% higher than the resin capacity in neutral pH). Iodide removal selectivity in the presence of three commonly encountered anions \({{\text{SO}}}_{4}^{2-}\), \({{\text{NO}}}_{3}^{-}\) and \({{\text{Cl}}}^{-}\) was improved. The iodide selectivity of oxidizing resin in the presence of \({{\text{Cl}}}^{-}\) ion was excellent. Breakthrough curves of both resins with and without encountered anions were fitted with common breakthrough curve models. The results were consistent with the results of the batch mood experiments. Pseudo-second-order kinetic was described kinetic behavior of both resins well. An iodide adsorption mechanism was proposed using the results of batch experiments and the resin characterizations (XPS and Raman spectra). The potential of oxidizing resin for iodide oxidation into iodine increased the capacity and selectivity of resin toward iodide ions.