Chemically Modified Sawdust as Renewable Adsorbent for Arsenic Removal from Water

Environmentally friendly and cost-effective adsorbent materials for arsenic extraction are needed for removing pollutants from groundwater. Here, lanthanum or zirconium oxide nanoparticle-incorporated sawdust was used for the removal of arsenic anions from water. The chemically modified sawdust was fully characterized and used for extraction of arsenic from water. The influences of ionic strength, pH, and interfering ionic pollutants toward the extraction efficiency of arsenic anions were investigated to understand the mechanism. ZrO2-sawdust showed extraction capacities of 29 and 12 mg/g for arsenite and arsenate anions, respectively, while La(2)O(3-)sawdust extracted arsenite (22 mg/g) and arsenate (28 mg/g) anions efficiently. Desorption studies were performed on surface-modified sawdust to check the recyclability. La2O3-sawdust can be fully regenerated with no change in arsenic removal efficiency, while ZrO2-sawdust retains similar to 50% of its adsorption efficiency. Such modified renewable bioadsorbents are useful for developing environmentally friendly materials for water purification.