Natural polyphenol-assisted peroxymonosulfate activation for the degradation of ofloxacin in iron-based Fenton-like process

In this study, trace chlorogenic acid (CGA) was introduced as a natural reductant and ligand to facilitate the activation of Fe(III) in a sulfate radical-based advanced oxidation process (SR-AOP), enabling effective Fenton-like degradation of ofloxacin (OFL) under mild conditions. The CGA/Fe(III)/PMS system exhibited excellent performance in the degradation of ofloxacin (OFL) at near-neutral pH. The presence of CGA effectively promoted Fe(III)/Fe(II) cycling via dual redox and chelation effects, thereby enhancing PMS activation. Reactive oxygen species (ROS) analysis suggested that sulfate radicals (SO 4 ·− ) were the dominant contributors to OFL degrdation, while other reactive species played minor roles. The system maintained high activity in the presence of common coexisting anions in water (e.g., Cl − , and SO 4 2− ), whereas HCO 3 − and HPO 4 2− significantly suppressed degradation. These findings demonstrated the promising potential of CGA as an environmentally compatible additive for Fe(III)-based AOPs, providing useful mechanistic insight for mitigating antibiotic contamination in aquatic environments. Graphical abstract