Recent advances in persulfate activation by magnetic ferrite-carbon composites for organic contaminants degradation: Role of carbon materials and environmental application

Abstract

Residual organic contaminants in water environment pose a huge threat to ecosystem and human health. As an efficient and clean technology, persulfate (PS)-based advanced oxidation processes (PS-AOPs) can efficiently remove organic contaminants from wastewater. Spinel ferrite magnetic materials or carbonaceous materials (rGO, CNTs, BC, etc.) have been widely used as the effective heterogeneous catalysts for activation of PS to degrade various organic contaminants in water. Coupling carbon catalysts with spinel ferrite improves the PS activation efficiency and solves the separation problem of carbon catalysts. This paper firstly reviews the recent advances in PS activation by magnetic ferrite-carbon (MFC) composite materials for organic contaminants degradation in water. In-depth discussion of the mechanism for PS (including PMS and PDS) activation by MFC composite catalysts was conducted, and the degradation of organic contaminants in MFC/PS systems was achieved via the radical and/or non-radical reaction pathways. The main role of carbon materials involved in MFC/PS systems includes preventing the aggregation of ferrite particles and increasing the exposure of reactive sites on ferrites, providing additional active sites for PS activation, promoting electron transfer involved in PS activation and organic contaminant degradation and reducing the leaching of metal ions from ferrites. Moreover, the environmental application of MFC-activated PS oxidation systems was discussed, including the effect of reaction conditions, stability and reusability of MFC catalyst, flow reactor configuration and cost-efficiency analysis. Finally, the possible future developments are presented.