Guo Shu-Xi, Hu Hui-Xian, Wang Pin, Guo Yu-En, Lu Yao, Du Ye
College of Architecture and Environment, Sichuan University, Chengdu 610000, China.
Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan.
Water Res. 2025 Jul 14;286:124219. doi: 10.1016/j.watres.2025.124219.
Chloramination is widely employed in water treatment due to its reduced formation of traditional disinfection byproducts (DBPs); however, the halogenated DBPs formed through reactions with organic precursors in matrices such as Suwannee River Natural Organic Matter (SRNOM) and wastewater remain incompletely characterized. Tannic acid, a prevalent phenolic precursor in these matrices, was systematically investigated in this study to elucidate the structural features, formation mechanisms, and toxicological risks of halogenated DBPs generated during chloramination. Using ultra-performance liquid chromatography coupled with high-resolution mass spectrometry (UPLCHRMS), we identified 28 chlorinated disinfection byproducts (Cl-DBPs) and 17 brominated disinfection byproducts (Br-DBPs) compounds, with molecular structures resolved for 13 Cl-DBPs and 8 Br-DBPs. Key intermediates, such as gallic acid derivatives, underwent halogenation via electrophilic substitution, nucleophilic attack, and decarboxylation, yielding aromatic, non-aromatic cyclic, aliphatic, and heterocyclic halogenated DBPs. These halogenated DBPs were detected in chloraminated SRNOM and wastewater effluents, demonstrating their environmental prevalence. In vitro cytotoxicity results showed the toxicity of identified 3,5-dichloro-4-hydroxybenzoic acid lies between that of monochloroacetamide and dichloroacetamide, underscoring its health impacts. In silico toxicity analysis using Quantitative Structure-Activity Relationship (QSAR) models predicted higher acute ecological toxicity for most Cl-DBPs and Br-DBPs compared to traditional DBPs such as monochloroacetamide and dichloroacetamide, with certain compounds exhibiting potential developmental toxicity and mutagenicity risks. This study underscores the pivotal role of tannic acid as a key DBP precursor, and emphasizes the need for advanced monitoring and risk mitigation strategies to address the emerging threats posed by these contaminants in treated water systems.
由于氯胺消毒减少了传统消毒副产物（DBPs）的生成，因此在水处理中被广泛应用；然而，通过与诸如苏万尼河天然有机物（SRNOM）和废水等基质中的有机前体反应形成的卤代DBPs仍未得到充分表征。本研究对这些基质中普遍存在的酚类前体单宁酸进行了系统研究，以阐明氯胺消毒过程中产生的卤代DBPs的结构特征、形成机制和毒理学风险。使用超高效液相色谱与高分辨率质谱联用（UPLC-HRMS），我们鉴定出28种氯化消毒副产物（Cl-DBPs）和17种溴化消毒副产物（Br-DBPs）化合物，其中13种Cl-DBPs和8种Br-DBPs的分子结构得到了解析。关键中间体，如没食子酸衍生物，通过亲电取代、亲核攻击和脱羧进行卤化反应，生成芳香族、非芳香族环状、脂肪族和杂环卤代DBPs。这些卤代DBPs在氯胺消毒的SRNOM和废水排放物中被检测到，表明它们在环境中普遍存在。体外细胞毒性结果表明，所鉴定的3,5-二氯-4-羟基苯甲酸的毒性介于一氯乙酰胺和二氯乙酰胺之间，突出了其对健康的影响。使用定量构效关系（QSAR）模型进行的计算机毒性分析预测，与一氯乙酰胺和二氯乙酰胺等传统DBPs相比，大多数Cl-DBPs和Br-DBPs具有更高的急性生态毒性，某些化合物表现出潜在的发育毒性和致突变风险。本研究强调了单宁酸作为关键DBP前体的关键作用，并强调需要先进的监测和风险缓解策略，以应对这些污染物在处理后的水系统中带来的新威胁。
