摘要
Benzothiazole, a high-production chemical used in domestic and industrial applications, possesses a persistent nature and is ubiquitous in aquatic environments; this study aims to investigate benzothiazole degradation by utilizing a UV-activated persulfate process (UV/persulfate). The results demonstrated that the UV/persulfate process can efficiently degrade benzothiazole in deionized water (the pseudo-first-order degradation rate constant (k obs ) was 0.0847 min −1 under the experimental conditions of [benzothiazole] 0 = 10 mg/L, [persulfate] 0 = 150 mg/L and initial solution pH = 7). k obs and persulfate dose (18.75 to 150 mg/L) exhibited a linearly proportional relationship (R 2 = 0.9696). The optimal benzothiazole degradation rate occurred at pH 7 (k obs = 0.0847 min −1 ) compared with those at pH 3 (k obs = 0.0516 min −1 ) and 11 (k obs = 0.0450 min −1 ). The presence of common water constituents (HCO 3 – , Cl – , NO 3 – and dissolved organic matter) had an inhibitory effect on benzothiazole degradation. Radical scavenger experiments showed that both SO 4 • – and •OH were involved in benzothiazole degradation, with SO 4 • – playing a relatively predominant role. The second-order rate constant between SO 4 • – and benzothiazole was 2.1 × 10 9 M −1 s −1 . Two transformation byproducts of benzothiazole degradation were detected, which were generated through the dihydroxylation and trihydroxylation reactions of benzothiazole. During the UV/persulfate process, the toxicity (Microtox®) increased and then declined within 60 min of reaction time. The results suggested that the UV/persulfate process is an efficient way to remove benzothiazole from water.