Effective remediation of arsenate from contaminated water by zirconium modified pomegranate peel as an anion exchanger

Abstract We have synthesized zirconium-modified pomegranate peel (SPP@Zr) as a novel biomass-based anion exchanger for the effective remediation of arsenate (As(V)) from contaminated water. The synthesized material was morphologically and texturally characterized. The adsorption kinetics and isotherm studies revealed that the experimental results could be better interpreted in terms of pseudo-second-order kinetic and Langmuir isotherm models, respectively. The SPP@Zr exhibited outstanding remediation capacities for As(V), having a maximal loading capacity of 83.33 mg g−1 at pH 4.0 and 298 K. Thermodynamic studies revealed the arsenate sorption onto as-synthesized adsorbent was endothermic and spontaneous. The spent adsorbent could be readily regenerated using an alkaline solution and be repeatedly used. The mechanism study has shown that both ligand exchange and electrostatic attraction play crucial roles in the adsorption of oxyanions of As(V). An X-ray photoelectron spectroscopy (XPS) study of sorption products revealed that no reduction of As(V) to As(III) occurred during the adsorption process. Finally, the SPP@Zr was applied for the dearsenification of natural groundwater samples and was found very efficient at capturing arsenic far below the mark of tolerance level (10 μg L−1) of drinking water.