Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen, 361005, China.
School of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, 316022, China.
Environ Sci Pollut Res Int. 2018 Apr;25(10):9391-9401. doi: 10.1007/s11356-018-1223-z. Epub 2018 Jan 18.
This study investigated the transformation of triclosan (TCS) following co-exposure to UV irradiation and ClO. Special attention was given to understand the influencing of water quality parameters and toxicity changes during the co-exposure process. The results show that the co-exposure process prompted TCS elimination quickly and effectively, with more than 99% of TCS degraded under the experimental conditions. The molar yield ratios of 2,4-dichlorophenol/TCS (2,4-DCP/TCS) were calculated to be 35.81-74.49%; however, the by-product of 2,8-dichlorodibenzop-dioxin (2,8-ClDD) was not detected. The TCS degradation was sensitive to ClO dosage, pH, HO, and natural organic matter (NOM), but not to the carbonate (CO) concentration. Neutral and slightly alkaline condition were favorable to TCS elimination. The TCS removal rate increased from 85.33 to 99.75% when the ClO concentration increased from 0.25 to 1.5 mg L. TCS degradation can be promoted at low NOM level (1, 3, and 5 mg L), whereas was inhibited at high NOM concentrations of 7 and 9 mg L. While adding HO, the degradation rate of TCS increased with increasing HO concentration from 1 to 3 mg L; however, too low or overdosed HO (0.5 and 5 mg L) hindered TCS degradation. Based on the results of a microtox bioassay, the toxicity did not change following the co-exposure process.
本研究考察了三氯生（TCS）在同时暴露于紫外辐射和 ClO 下的转化情况。特别关注了解水质参数在共暴露过程中的影响和毒性变化。结果表明，共暴露过程能快速有效地促进 TCS 的消除，在实验条件下，超过 99%的 TCS 被降解。计算得出 2,4-二氯苯酚/TCS（2,4-DCP/TCS）的摩尔产率比为 35.81-74.49%；然而，未检测到 2,8-二氯二苯并-p-二恶英（2,8-ClDD）的副产物。TCS 的降解对 ClO 剂量、pH 值、HO 和天然有机物（NOM）敏感，但对碳酸盐（CO）浓度不敏感。中性和弱碱性条件有利于 TCS 的消除。当 ClO 浓度从 0.25 增加到 1.5 mg/L 时，TCS 的去除率从 85.33%增加到 99.75%。在低 NOM 水平（1、3 和 5 mg/L）下，TCS 降解可以被促进，而在高 NOM 浓度（7 和 9 mg/L）下则受到抑制。当添加 HO 时，TCS 的降解速率随着 HO 浓度从 1 增加到 3 mg/L 而增加；然而，过低或过高剂量的 HO（0.5 和 5 mg/L）会阻碍 TCS 的降解。根据微毒生物测定的结果，共暴露过程后毒性没有变化。
