Photo-degradation ibuprofen by UV/H2O2 process: response surface analysis and degradation mechanism

The removal of ibuprofen (IBP) in aqueous solution using UV/H 2 O 2 process was evaluated. The response surface methodology (RSM) and Box–Behnken design were employed to investigate the effects of process parameters on IBP removal, including the initial IBP concentration, H 2 O 2 dosage, UV light intensity, and initial pH value of solution. The RSM model developed herein fits well with the experiments, and provides a good insight into the OH radical irritated degradation mechanisms and kinetics. High resolution accurate mass spectrometry coupled with liquid chromatography was used to identify the degradation intermediates. A total of 23 degradation products were identified, including mono-hydroxylated products and dihydroxylated products. A series of OH radical-initiated reactions, including hydroxylation, dihydroxylation, decarboxylation, demethylation, ring break, lead to the final mineralization of IBP to CO 2 and H 2 O. UV/H 2 O 2 technology could be a promising technology for IBP removal in aqueous solution.