Dissolved organic matter (DOM) composition influences the formation of disinfection byproducts (DBPs) during drinking water treatment, yet the role of DOM composition at the molecular level in forming both known and novel DBPs has not been established. We characterized the composition of DOM from drinking water utilities that draw from surface (n = 4) and groundwaters (n = 14), focusing on groundwater because the reactivity of its DOM is poorly understood. We quantified the formation of targeted DBPs, identified novel high molecular weight (HMW) halogenated DBPs, and analyzed DOM transformation after reaction with free available chlorine. Characterization by UV–visible spectroscopy and Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) reveals a high degree of variability in DOM composition and reactivity with chlorine, particularly among groundwater samples. Despite the variability in DOM composition, novel DBPs with up to three halogens are compositionally similar among all waters and are positively correlated with trihalomethane and, to a lesser extent, haloacetonitrile formation. These relationships demonstrate that some low molecular weight DBPs and novel DBPs detected by FT-ICR MS share similar aromatic precursors, providing evidence that DBPs such as trihalomethanes are a useful proxy for the formation of their HMW counterparts.

中文翻译：

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对传统和新型卤化消毒副产品形成的分子级洞察

溶解有机物 (DOM) 成分会影响饮用水处理过程中消毒副产物 (DBP) 的形成，但尚未确定 DOM 成分在分子水平上在形成已知和新型 DBP 中的作用。我们描述了取自地表水 ( n = 4) 和地下水 ( n= 14)，专注于地下水，因为对其 DOM 的反应性知之甚少。我们量化了目标 DBP 的形成，鉴定了新型高分子量 (HMW) 卤化 DBP，并分析了与游离有效氯反应后的 DOM 转化。紫外-可见光谱和傅里叶变换离子回旋共振质谱 (FT-ICR MS) 的表征揭示了 DOM 组成和与氯的反应性的高度可变性，尤其是在地下水样品中。尽管 DOM 组成存在差异，但含有多达三个卤素的新型 DBP 在所有水体中的组成相似，并且与三卤甲烷和在较小程度上与卤代乙腈的形成呈正相关。