School of Public Health, Soochow University, Suzhou 215122, China.
School of Public Health, Soochow University, Suzhou 215122, China.
Sci Total Environ. 2023 May 1;871:161971. doi: 10.1016/j.scitotenv.2023.161971. Epub 2023 Feb 3.
To prevent the reactions of disinfection byproducts (DBPs) or natural organic matters with residual chlorine in drinking water in the course of the water store, residual chlorine is quenched by chlorine quenchers, while some chlorine quenchers may result in dechlorination of DBPs. Phenolic compounds are a group of highly toxic DBPs compared to regulated aliphatic DBPs (trihalomethanes (THMs) and haloacetic acids (HAAs)), which might be a great threat to drinking water safety. Nevertheless, impact of popular chlorine quenchers on phenolic DBPs is less understanding. In this study, the influences of ammonium chloride, ascorbic acid, sodium thiosulfate, and sodium sulfite on phenolic DBPs are assessed. Total concentration of 19 phenolic DBPs in drinking water from 7 Chinese cities was 145-1821 ng/L, suggesting a widely occurrence of these pollutants. Four assessed chlorine quenchers have not impacts on mass spectra of studied phenolic DBPs. Additionally, when the storage time ≤24 h, recoveries of 19 phenolic DBPs using four assessed chlorine quenchers are within the accept levels (70-130 %). However, when the storage time increased to 168 h, ascorbic acid and sodium thiosulfate satisfied the recovery requirement of phenolic DBPs during the sample analysis, and ammonium chloride and sodium sulfite showed a unacceptable impact on bromo-chloro-phenols. In general, ascorbic acid and sodium thiosulfate are recommended to be the ideal chlorine quenchers of phenolic DBPs. Mechanism study indicated that sodium sulfite induced the dechlorination of 2-chloro-4-bromophenol via nucleophilic reaction. This study is the first attempt to provide the impact of chlorine quenchers on phenolic DBPs and corresponding reaction mechanism.
为了防止在储水过程中饮用水中消毒副产物（DBPs）或天然有机物与余氯发生反应，余氯会被氯猝灭剂淬灭，而一些氯猝灭剂可能导致 DBPs 的脱氯。与受管制的脂肪族 DBPs（三卤甲烷（THMs）和卤乙酸（HAAs））相比，酚类化合物是一组毒性更高的 DBPs，它们可能对饮用水安全构成巨大威胁。然而，目前对于常用氯猝灭剂对酚类 DBPs 的影响了解较少。在这项研究中，评估了氯化铵、抗坏血酸、硫代硫酸钠和亚硫酸钠对酚类 DBPs 的影响。来自中国 7 个城市的饮用水中 19 种酚类 DBPs 的总浓度为 145-1821ng/L，表明这些污染物广泛存在。四种评估的氯猝灭剂对所研究的酚类 DBPs 的质谱没有影响。此外，当储存时间≤24 小时时，使用四种评估的氯猝灭剂时，19 种酚类 DBPs 的回收率在可接受范围内（70-130%）。然而，当储存时间增加到 168 小时时，抗坏血酸和硫代硫酸钠满足了酚类 DBPs 在样品分析过程中的回收率要求，而氯化铵和亚硫酸钠对溴氯酚类化合物表现出不可接受的影响。总的来说，抗坏血酸和硫代硫酸钠被推荐为酚类 DBPs 的理想氯猝灭剂。机理研究表明，亚硫酸钠通过亲核反应诱导 2-氯-4-溴苯酚脱氯。本研究首次尝试提供氯猝灭剂对酚类 DBPs 的影响及其相应的反应机制。
