The pollution of antimony (Sb) species in natural waters has drawn more and more attention due to their high cumulative toxicity and carcinogenicity. In recent years, it is highly in demand to develop efficient and economical technologies to address the increasing pollution of antimony all over the world. Iron-based composite materials (e.g. Fe⁰, Fe₃O₄, and FeMnO_x) have become a research hotspot in the field of antimony treatment based on their various advantages, including high adsorption capacity, easy separation and recycling, safety and environmental friendliness, etc. This article summarizes the preparation, modification and application of iron-based composite materials based on zero-valent iron, ferric oxide and iron bimetallic oxide for the removal of Sb(Ⅲ) and Sb(Ⅴ) in water. The adsorption mechanisms of Sb(Ⅲ) and Sb(Ⅴ) by different iron-based composite materials are emphatically discussed. The effects of temperature, pH and co-existing ions on the Sb adsorption of iron-based composite materials are also investigated, to find the optimal adsorption condition. Finally, some primary issues about antimony removal are proposed and the outlook of key developing trends on the antimony removal by iron-based composite materials are presented.
Contents
1 Introduction
2 The removal of Sb by zero-valent iron based composite materials
2.1 The physical modification of nano-Fe⁰
2.2 The loading modification of nano-Fe⁰
2.3 The stabilization modification of nano-Fe⁰
3 The removal of Sb by ferric oxide based composite materials
3.1 The composite materials based on magnetic Fe₃O₄
3.2 The composite materials based on ferric oxide hydrate
4 The removal of Sb by iron bimetallic oxide based composite materials
4.1 Iron and manganese oxides
4.2 Other iron bimetallic oxides
5 Conclusion