State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai, 200092, China.
School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
Water Res. 2019 Dec 15;167:115096. doi: 10.1016/j.watres.2019.115096. Epub 2019 Sep 17.
The effects of UV/HO pre-oxidation or disinfection methods on the formation of partial disinfection by-products (DBPs) have been studied previously. This study assessed the effect of UV/HO pre-oxidation combined with optimisation of the disinfection method on the formation of six classes of CXR-type DBPs, including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetaldehydes (HALs), haloacetonitriles (HANs), halonitromethanes (HNMs), and haloacetamides (HAMs). Experimental results showed that a simulated distribution system (SDS) in-situ chloramination or pre-chlorination followed by chloramination effectively decreased total CXR-type DBP formation by 51.1-63.5% compared to SDS chlorination, but little reduction in DBP-associated toxicity was observed. The dominant contributors to the calculated toxicity were HANs and HALs. UV/HO pre-oxidation was able to destroy the aromatic and dissolved organic nitrogen components of natural organic matter. As a consequence, THM, HAA, and HAL formations increased by 49.5-55.0%, 47.8-61.9%, and 42.0-67.1%, respectively, whereas HAN, HNM, and HAM formations significantly decreased by 52.1-83.6%, 42.9-87.3%, and 74.1-100.0%. UV/HO pre-oxidation increased total CXR-type DBP formation, during SDS chlorination, whereas SDS in-situ chloramination or pre-chlorination followed by chloramination of UV/HO-treated water produced lower total CXR-type DBPs than water without UV/HO pre-oxidation. Nevertheless, the DBP-associated toxicity of water with UV/HO pre-oxidation was substantially lower than the toxicity for water without UV/HO pre-oxidation, decreased by 24.1-82.7%. HALs followed by HANs contribute to major toxic potencies in UV/HO treated water. The best DBP concentration and DBP-associated toxicity abatement results were achieved for water treated by UV/HO coupled with in-situ chloramination treatment.
先前已经有研究考察了 UV/HO 预氧化或消毒方法对部分消毒副产物（DBP）形成的影响。本研究评估了 UV/HO 预氧化与优化消毒方法相结合对六类 CXR 型 DBP（包括三卤甲烷（THMs）、卤乙酸（HAAs）、卤乙醛（HALs）、卤乙腈（HANs）、卤硝基甲烷（HNMs）和卤乙酰胺（HAMs））形成的影响。实验结果表明，与 SDS 氯化相比，模拟配水系统（SDS）原位氯胺化或预氯化后再进行氯胺化可使总 CXR 型 DBP 形成降低 51.1-63.5%，但 DBP 相关毒性的降低幅度较小。计算出的毒性的主要贡献者是 HANs 和 HALs。UV/HO 预氧化能够破坏天然有机物中的芳香族和溶解有机氮成分。因此，THM、HAA 和 HAL 的形成分别增加了 49.5-55.0%、47.8-61.9%和 42.0-67.1%，而 HAN、HNM 和 HAM 的形成则分别显著降低了 52.1-83.6%、42.9-87.3%和 74.1-100.0%。UV/HO 预氧化增加了 SDS 氯化过程中的总 CXR 型 DBP 形成量，而 SDS 原位氯胺化或 UV/HO 处理水的预氯化后再进行氯胺化生成的总 CXR 型 DBP 比未经 UV/HO 预氧化的水要少。然而，经 UV/HO 预氧化的水的 DBP 相关毒性显著低于未经 UV/HO 预氧化的水，降低了 24.1-82.7%。HALs 紧随 HANs 之后是 UV/HO 处理水中主要的毒性潜能。UV/HO 与原位氯胺化处理相结合处理的水达到了最佳的 DBP 浓度和 DBP 相关毒性降低效果。
