Removal of Antimony (V) from Aqueous Solution by Iron-based Adsorbents

Antimony pollution has attracted increasing attention for its toxicity. In this study, iron oxide, copper oxide and Fe-Cu binary oxide were synthesized by chemical precipitation/co-precipitation method and investigated using XRD, SEM and FTIR characterizations. Then Sb(V) removal from water by different adsorbents was evaluated. Moreover, the effect of solution pH and initial adsorbents dose was systematically investigated. It was found that removal capacity of kaolinite, aluminum oxide and MWCNTs was poor. However, Sb(V) adsorption on iron oxide and copper oxide was rapid and followed a pseudo-second-order rate law. The equilibrium adsorption capacity increased with the increasing of adsorbent dosage. Especially, when pH <5.0, the removal percentage of Sb(V) by iron oxide sharply increased. Sb(V) uptake by Fe-Cu binary oxide was better than both iron oxide and copper oxide. FTIR analysis confirmed the presence of active -OH and dynamic analysis indicated that chemical adsorption was dominant mechanism for Sb(V) adsorption. Above all, the production process of iron-based adsorbents was simple and they possessed high adsorption ability for Sb(V), Therefore, iron oxide and Fe-Cu binary oxide were promising adsorbents for antimony removal from contaminated water.