Fe (III)-Aminopolycarboxylate Complexes Enhance Photo-Fenton-Like UV/Sodium Percarbonate Process for Pharmaceutical Degradation.

Pharmaceutical residues are frequently detected in aquatic systems due to incomplete degradation during conventional treatment. This study evaluated a batch-scale ultraviolet/sodium percarbonate/Fe (III)-aminopolycarboxylate system for ibuprofen degradation under near-neutral conditions. Four Fe (III)-aminopolycarboxylate complexes, prepared using iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid, were compared. Fe (III)-diethylenetriaminepentaacetic acid showed the highest catalytic activity at pH 7, increasing the apparent rate constant from 0.0551 to 0.2270 min-1. Radical scavenging experiments suggested an apparent shift from carbonate radical-mediated oxidation toward hydroxyl radical-driven degradation. Response surface methodology identified catalyst concentration and reaction time as the most influential factors. Under proportional dosage-escalated conditions, 94.7% ibuprofen degradation was achieved within 14 min. Liquid chromatography-tandem mass spectrometry tentatively identified eight transformation products. The system also degraded structurally diverse pharmaceuticals in mineral and surface water matrices, supporting its potential for further development.