Successive non-radical and radical process of peroxymonosulfate-based oxidation using various activation methods for enhancing mineralization of sulfamethoxazole

To enhance the mineralization of toxic organic pollutants is crucial for the alleviation of environmental pollution . In this study, the successive non-radicals and radicals process (SNRP) of peroxymonosulfate (PMS)-based oxidation was performed using various methods for PMS activation , including UV, ozone, gamma radiation and biochar and applied for enhancing the mineralization of sulfamethoxazole (SMX). The results showed that SNRP-UV could improve the mineralization of SMX, and both SNRP-UV and PMS/UV could completely mineralize SMX. For SNRP-Ozone, SNRP-Radiation and SNRP-Biochar, compared to the sole radical oxidation, all SNRPs could enhance the mineralization of SMX. The biochar-induced SNRP obtained the maximum mineralization increment, followed by gamma irradiation-induced SNRP and ozone-induced SNRP. Sulfate radicals were mainly responsible for SMX mineralization for SNRP-Biochar, while hydroxyl radicals for SNRP-Radiation, and the synergetic effect of ozone and sulfate radicals for SNRP-Ozone. Different degradation intermediate products were identified in different SNRP, further revealing that SNRP induced by different methods had different mineralization capacity. This study further demonstrated that SNRP could be a new strategy for enhancing the mineralization of SMX.