Ligand-Enhanced Zero-Valent Iron for Organic Contaminants Degradation: A Mini Review

For nearly three decades, zero-valent iron (ZVI) has been used in wastewater treatment and groundwater soil remediation. ZVI can degrade contaminants by reactions of adsorption, redox, co-precipitation. It also react with oxidants like hydrogen peroxide, persulfate, ozone to produce highly reactive radicals that rapidly remove even mineralize organic contaminants. However, the application is limited factors such as narrow pH range surface passivation. The addition chelating agents nitrilotriacetic acid (NTA), ethylenediaminetetraacetic (EDTA), or citrate ZVI-based processes identified greatly increase stability improve efficiency contaminant degradation. From perspective commonly inorganic applications, review addresses current status ligand-enhanced degradation contaminants, illustrates possible reaction mechanism, provides perspectives for further research.