State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Environ Sci Technol. 2010 May 15;44(10):3908-12. doi: 10.1021/es100397x.
Haloacetamides (HAcAms) are an emerging class of nitrogenous disinfection byproducts (N-DBPs). However, there is a limited understanding about the precursors of HAcAms. In this study, we screened the precursors of dichloroacetamide (DCAcAm), the most commonly identified HAcAm in chlorinated or chloraminated drinking water. DCAcAm formation potential (FP) of raw water samples collected in different months from a reservoir in China was determined during chlorination, and the highest DCAcAm FP typically occurred in the summer samples. Dissolved organic matter (DOM) in a representative summer raw water sample was separated into six fractions by a series of resin elutions. Among them, hydrophilic acid (HiA) DOM showed the maximum DCAcAm FP, followed by hydrophilic bases (HiB) and, to a much lower extent, hydrophobic acids (HoA). Fluorescence excitation-emission matrix (EEM) spectra revealed that a mass of protein-like substances in the HiA fraction, made up of amino acids (AAs), were the likely DCAcAm precursors. Finally, we investigated the DCAcAm yields of 20 AAs during chlorination. Among them, seven AAs (aspartic acid, histidine, tyrosine, tryptophan, glutamine, asparagine, phenylalanine) could form DCAcAm during chlorination, with the corresponding DCAcAm yields of 0.231, 0.189, 0.153, 0.104, 0.078, 0.058, and 0.050 mmol/mol AA.
卤乙酰胺（HAcAms）是一类新兴的含氮消毒副产物（N-DBPs）。然而，人们对 HAcAms 的前体物质了解有限。在这项研究中，我们筛选了二氯乙酰胺（DCAcAm）的前体物质，DCAcAm 是氯化或氯胺化饮用水中最常见的 HAcAm。在氯化过程中，测定了取自中国某水库不同月份的原水样品中二氯乙酰胺形成潜能（DCAcAm FP），夏季水样中二氯乙酰胺 FP 通常最高。采用一系列树脂洗脱法将代表性夏季原水水样中的溶解性有机物（DOM）分离成六个部分。其中，亲水性酸（HiA）DOM 表现出最大的 DCAcAm FP，其次是亲水性碱（HiB），而疏水性酸（HoA）的 FP 则低得多。荧光激发-发射矩阵（EEM）光谱表明，HiA 部分中大量的类蛋白质物质由氨基酸（AAs）组成，可能是 DCAcAm 的前体物质。最后，我们研究了 20 种氨基酸在氯化过程中的 DCAcAm 生成量。其中，七种氨基酸（天冬氨酸、组氨酸、酪氨酸、色氨酸、谷氨酰胺、天冬酰胺、苯丙氨酸）在氯化过程中可以形成 DCAcAm，对应的 DCAcAm 生成量分别为 0.231、0.189、0.153、0.104、0.078、0.058 和 0.050mmol/mol AA。
