Ultimate Resourcization of Waste: Crab Shell-Derived Biochar for Antimony Removal and Sequential Utilization as an Anode for a Li-Ion Battery

Abstract

The development of high-capacity adsorbents is pivotal for the removal of antimonite (Sb(III)) and antimonate (Sb(V)) as priority pollutants in water. Herein, a Fe-La-doped biomass carbon adsorbent (Cs/Fe-La) was prepared for efficient removal of both Sb(III) and Sb(V). Cs/Fe-La shows excellent adsorption behavior for both Sb(III) and Sb(V) at 40 °C with a maximum capacity of 498 and 337 mg/g, respectively. Additionally, the antimony adsorption mechanism and the contribution of Cs/Fe-La composition to high capacity were analyzed based on the characterization of physicochemical analysis and adsorption studies, and the pseudo-second-order kinetic model as well as the Langmuir model fit the results well. Remarkably, considering the secondary pollution caused by direct disposal of antimony-containing waste adsorbents, an antimony-enriched waste adsorbent (Cs/Fe-La-SbOx) was used as an anode material for a Li-ion battery. The heat-treated waste adsorbent exhibited good cycling performance with a reversible specific capacity of 833.8 mAh/g after 500 cycles. This work has demonstrated a promising pathway that can achieve the removal and sustainable utilization of antimony simultaneously by minimizing antimony contamination and maximizing the recycling of antimony-enriched adsorbents.