Yang Du,Wen-Qian Wang,Zhou-Tao Pei,Fahmi Ahmad,Rou-Rou Xu,Yi-Min Zhang,Li-Wei Sun
Ultraviolet (UV)-absorbing chemicals (UV filters) are used in personal care products for the protection of human skin and hair from damage by UV radiation. Although these substances are released into the environment in the production and consumption processes, little is known about their ecotoxicology effects. The acute toxicity and potential ecological risk of UV filters benzophenone-3 (BP-3) and benzophenone-4 (BP-4) onChlorella vulgaris,Daphnia magna, andBrachydanio reriowere analyzed in the present study. The EC50values (96 h) of BP-3 and BP-4 onC. vulgariswere 2.98 and 201.00 mg/L, respectively. The 48 h-LC50of BP-3 and BP-4 onD. magnawere 1.09 and 47.47 mg/L, respectively. The 96 h-LC50of BP-3 and BP-4 onB. reriowere 3.89 and 633.00 mg/L, respectively. The toxicity of a mixture of BP-3 and BP-4 onC. vulgaris,D. magna, andB. rerioall showed antagonistic effects. The induced predicted no-effect concentrations of BP-3 and BP-4 by the assessment factor method were 1.80 × 10−3and 0.47 mg/L, respectively, by assessment factor (AF) method, which were both lower than the concentrations detected in the environment at present, verifying that BP-3 and BP-4 remain low-risk chemicals to the aquatic ecosystem.Keywords:benzophenone-3;benzophenone-4;UV filters;acute toxicity;ecological risk assessment
The degradation kinetics, reaction pathways, and disinfection by-products formation of an organic UV filter, benzophenone-4 (BP4) during UV/persulfate oxidation were investigated. BP4 can hardly be degraded by UV alone, but can be effectively decomposed by UV/persulfate following pseudo-first order kinetics. BP4 degradation rate was enhanced with increasing persulfate dosage and decreasing pH from 8 to 5. However, the degradation rate of BP4 at pH 9 was higher than that at pH 8 because of the presence of phenolic group in BP4 structure. and SO4−⋅ were confirmed as the major contributors to BP4 decomposition in radical scavenging experiments, and the second-order rate constants between HO⋅ and BP4 as well as those between SO4−⋅ and BP4 were estimated by establishing and solving a kinetic model. The presence of Br− and humic acid inhibited the decomposition of BP4, while NO3− promoted it. The mineralisation of BP4 was only 9.1% at the persulfate concentration of 50 μM. Six degradation intermediates were identified for the promulgation of the reaction pathways of BP4 during UV/persulfate oxidation were proposed as a result. In addition, the formation of DBP in the sequential chlorination was evaluated at different persulfate dosages, pH values, and water matrix. The results of this study can provide essential knowledge for the effective control of DBP formation with reducing potential hazard to provide safe drinking water to the public.
危险品化学品经营许可证（带存储）