Selective separation of Cr(VI) and V(V) from solution by simple pH controlled two-step adsorption/desorption process with ZrO2

The recovery and separation of vanadium and chromium from vanadium-containing chromate solution are necessary and valuable for the comprehensive utilization and environmental protection of V-Ti-bearing magnetite ore. In this work, a tetragonal ZrO2 adsorbent was used for harmless treatment and resource reuse of a low-concentration vanadium-containing chromate solution. Results confirmed that water after treatment met the wastewater discharge standard; in addition, Cr(VI) and V(V) were efficiently separated with the V/Cr separation coefficient of 362.05 for the pH of 3.5 and the V/Cr ratio of 1:1 at the concentration of 80 mg/L. This excellent and stable separation performance of ZrO2 was ascribed to the competitive adsorption of V(V) and Cr(VI) on ZrO2, owing to the strong effect of pH on their adsorption and desorption behavior. V(V) and Cr(VI) in vanadium-containing chromate solution can be removed, recovered, separated and enriched through a two-step adsorption/desorption process. The purity of vanadium and chromium can reach more than 99.8%. The adsorption of vanadium and chromium by ZrO2 has high application value, which is beneficial to the recovery of resources and environmental protection.