Sarveishwhary Rajendran, Cheng Wei Nyeow, Nazzatush Shimar Jamaludin, Kah Hin Low, Kheng Soo Tay
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.