Enhanced degradation of triclosan by gamma radiation with addition of persulfate

In this study, gamma radiation was used for triclosan (TCS) degradation with addition of persulfate (PS) to enhance the mineralization of TCS. The influence of absorbed doses, PS concentration, and initial pH value on TCS degradation and mineralization was examined. The results showed that the degradation and mineralization of TCS were remarkably enhanced in the presence of PS. With addition of 1.5 mM PS, 8 mg/L TCS could be completely degraded at 300 Gy, which was much lower than that of the control group without PS (600 Gy). Furthermore, with addition of PS, higher mineralziaiton of TCS could be observed. The intermediates produced during the decomposition of TCS were identified and the possible degradation pathway was proposed. In addition, the biodegradability of TCS solution, as well as the intermediate products, was evaluated by a Wabo micro-respiration tester for 12 h. It demonstrated that the biodegradability of TCS solution increased after gamma radiation, which could be further enhanced by persulfate, suggesting that the combination of gamma radaition with persulfate could be a promising alternative process for the degradation of antibiotics in the wastewater.