Highly selective adsorption of vanadium (V) by nano-hydrous zirconium oxide-modified anion exchange resin

Abstract

Adsorption is widely used in removal of toxic vanadium (V) [V(V)] from water streams, and a fit-for-purpose adsorbent plays a vital role in this process. Herein HZrO@D201, an adsorbent with decoration of nanosized hydrous zirconium oxide (HZrO) on anion exchange resin D201, is fabricated for efficient V(V) removal. Compared to pristine D201, HZrO@D201 excelled in V(V) removal with a maximum adsorption capacity of 118.1 mg/g, due to potential formation of inner sphere complexation between V(V) and HZrO. HZrO@D201 could also functioned well in a wide pH range (3.00 to 9.00) and exhibited outstanding selective V(V) adsorption under the presence of competing anions (chloride, nitrate, sulfate, and phosphate). The adsorption thermodynamics was in accordance with the Langmuir model, while adsorption kinetics followed the Pseudo-Second-Order model. When treating actual vanadium contaminated groundwater from Panzhihua region (China), HZrO@D201 indicated a satisfactory lifespan in the column experiment for V(V) removal (2.41 times longer than D201), and the treated groundwater could meet the vanadium standard of drinking water source in China (less than 50 μg/L). Regeneration of HZrO@D201 was easily achievable with negligible capacity loss. Results from this work suggests a promising application potential of HZrO@D201 in vanadium pollution control.

Keywords: Anion exchange resin; Hydrous zirconium oxide; Nanocomposite; Selective adsorption; Vanadium (V).