Iron oxides accelerate soil electron transport to promote the degradation of organic pollutants: A review

Abstract

Organic pollutants in soil pose a threat to ecosystems and human health. Abundant iron oxides with high biological activity readily undergo electron exchange with organic pollutants, thereby facilitating pollutant degradation and the remediation of organic contaminants in soil. Here, the research progress on iron oxide-mediated electron transfer processes in soil and their roles in promoting the degradation of organic pollutants is reviewed. First, the unique properties and functions of iron oxides are introduced. Subsequently, direct and indirect electron transfer processes facilitated by iron oxides in soil are described, including oxidative degradation, reductive degradation, and radical-mediated degradation of organic contaminants during iron transformation. Finally, the environmental implications of soil iron oxides are summarized, including enhancement of organic pollutant bioremediation, regulation of methane emissions, promotion of biogenic element cycling, and contributions to microbial electrochemical processes. Overall, understanding the behaviour of iron oxides could contribute to the development of more effective strategies for soil pollution remediation.