Lei Xin, Lei Yu, Guan Jingmeng, Westerhoff Paul, Yang Xin
School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China.
School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85287-3005, United States.
Environ Sci Technol. 2022 Apr 5;56(7):4457-4466. doi: 10.1021/acs.est.1c08388. Epub 2022 Mar 18.
Dissolved organic matter (DOM) scavenges sulfate radicals (SO), and SO-induced DOM transformations influence disinfection byproduct (DBP) formation when chlorination follows advanced oxidation processes (AOPs) used for pollutant destruction during water and wastewater treatment. Competition kinetics experiments and transient kinetics experiments were conducted in the presence of 19 DOM fractions. Second-order reaction rate constants for DOM reactions with SO () ranged from (6.38 ± 0.53) × 10 M s to (3.68 ± 0.34) × 10 M s. correlated with specific absorbance at 254 nm (SUVA) ( = 0.78) or total antioxidant capacity ( = 0.78), suggesting that DOM with more aromatics and antioxidative moieties reacted faster with SO. SO exposure activated DBP precursors and increased carbonaceous DBP (C-DBP) yields (e.g., trichloromethane, chloral hydrate, and 1,1,1-trichloropropanone) in humic acid and fulvic acid DOM fractions despite the great reduction in their organic carbon, chromophores, and fluorophores. Conversely, SO-induced reactions reduced nitrogenous DBP yields (e.g., dichloroacetonitrile and trichloronitromethane) in wastewater effluent organic matter and algal organic matter without forming more C-DBP precursors. DBP formation as a function of SO exposure (concentration × time) provides guidance on optimization strategies for SO-based AOPs in realistic water matrices.
溶解有机物（DOM）能清除硫酸根自由基（SO），并且在水和废水处理过程中，当氯化作用紧跟用于污染物降解的高级氧化过程（AOPs）之后时，SO诱导的DOM转化会影响消毒副产物（DBP）的形成。在19种DOM组分存在的情况下进行了竞争动力学实验和瞬态动力学实验。DOM与SO反应的二级反应速率常数（）范围为（6.38±0.53）×10 M s至（3.68±0.34）×10 M s。与254 nm处的比吸光度（SUVA）（= 0.78）或总抗氧化能力（= 0.78）相关，这表明具有更多芳香族和抗氧化部分的DOM与SO反应更快。尽管腐殖酸和富里酸DOM组分中的有机碳、发色团和荧光团大幅减少，但SO暴露会激活DBP前体并提高含碳DBP（C-DBP）的产量（例如三氯甲烷、水合氯醛和1,1,1-三氯丙酮）。相反，SO诱导的反应降低了废水流出物有机物和藻类有机物中含氮DBP的产量（例如二氯乙腈和三氯硝基甲烷），且未形成更多的C-DBP前体。作为SO暴露（浓度×时间）函数的DBP形成情况为实际水基质中基于SO的AOPs的优化策略提供了指导。
