Photo-persulfate oxidation and mineralization of benzoic acid: Kinetics and optimization under UVC irradiation.

The strong oxidant, persulfate (PS, SO), was applied to treat the synthetic wastewater of benzoic acid (BA) under UV irradiation. UVC light initiated a chain reaction that derived the sulfate radical (SO•) and hydroxyl radical (HO•) from SO ion. The experiment parameters, including light irradiation (UVA and UVC), pH, dose ratio ([PS]/[BA]), initial concentration ([BA], mg/L), was optimized based on degradation efficiency and total organic carbon (TOC) removal of BA, which reached up to 100% and 96%, respectively, under pH 3.