摘要：The photodecomposition effect and photolysis-active species of sulfamethoxazole (SMX) were investigated in Milli-Q water under UV light. Various factors, such as light intensity, pH of solutions, concentration of SMX and common anions, were investigated in this study. It was proven that the higher light intensity, acidic solution and less concentration of SMX were beneficial for photodegradation of SMX. The results verified that SMX could be excited effectively, and induced the formation of reactive oxygen species. Moreover, the contributions of oxidation reaction and incited triplet states to photodegradation of SMX were clarified by the role of different active species scavengers and deoxygenation process. It was proven that the photodegradation of SMX was predominantly attributed to direct photolysis. The indirect photolysis of SMX was carried out in the presence of dissolved oxygen to form hydroxyl radicals, singlet oxygen and superoxide radicals. The clear hypothesized photolysis schemes are valuable for studying other photochemical processes in other complex aqueous matrices.
