State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China.
School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
Environ Sci Technol. 2023 Nov 28;57(47):18940-18949. doi: 10.1021/acs.est.3c00835. Epub 2023 May 19.
Peracetic acid (PAA) is an emerging alternative disinfectant for saline waters; HOBr or HOCl is known as the sole species contributing to halogenation reactions during PAA oxidation and disinfection. However, new results herein strongly indicated that the brominating agents (e.g., BrCl, Br, BrOCl, and BrO) are generated at concentrations typically lower than HOCl and HOBr but played significant roles in micropollutants transformation. The presence of Cl and Br at environmentally relevant levels could greatly accelerate the micropollutants (e.g., 17α-ethinylestraiol (EE2)) transformation by PAA. The kinetic model and quantum chemical calculations collectively indicated that the reactivities of bromine species toward EE2 follow the order of BrCl > Br > BrOCl > BrO > HOBr. In saline waters with elevated Cl and Br levels, these overlooked brominating agents influence bromination rates of more nucleophilic constituents of natural organic matter and increase the total organic bromine. Overall, this work refines our knowledge regarding the species-specific reactivity of brominating agents and highlights the critical roles of these agents in micropollutant abatement and disinfection byproduct formation during PAA oxidation and disinfection.
过氧乙酸（PAA）是一种新兴的盐水替代消毒剂；HOBr 或 HOCl 是已知的在 PAA 氧化和消毒过程中唯一参与卤化反应的物质。然而，本文中的新结果强烈表明，溴化剂（例如 BrCl、Br、BrOCl 和 BrO）以通常低于 HOCl 和 HOBr 的浓度生成，但在微污染物转化中发挥着重要作用。环境相关水平的 Cl 和 Br 的存在可以大大加速 PAA 对微污染物（如 17α-乙炔雌二醇（EE2））的转化。动力学模型和量子化学计算共同表明，溴物种对 EE2 的反应活性遵循 BrCl > Br > BrOCl > BrO > HOBr 的顺序。在氯和溴水平升高的盐水中，这些被忽视的溴化剂影响天然有机物中更亲核成分的溴化速率，并增加总有机溴。总的来说，这项工作完善了我们对溴化剂特定物种反应性的认识，并强调了这些溴化剂在 PAA 氧化和消毒过程中微污染物去除和消毒副产物形成中的关键作用。
