Abstract：
Dissolved organic matter (DOM) is important in determining the drinking water treatment and the supplied water quality. However, a comprehensive DOM study for the whole water supply system is lacking and the potential effects of secondary water supply are largely unknown. This was studied using dissolved organic carbon (DOC), absorption spectroscopy, and fluorescence excitation-emission matrices-parallel factor analysis (EEM-PARAFAC). Four fluorescent components were identified, including humic-like C1-C2, tryptophan-like C3, and tyrosine-like C4. In the drinking water treatment plants, the advanced treatment using ozone and biological activated carbon (O3-BAC) was more effective in removing DOC than the conventional process, with the removals of C1 and C3 improved by 17.7%-25.1% and 19.2%-27.0%. The absorption coefficient and C1-C4 correlated significantly with DOC in water treatments, suggesting that absorption and fluorescence could effectively track the changes in bulk DOM. DOM generally remained stable in each drinking water distribution system, suggesting the importance of the treated water quality in determining that of the corresponding network. The optical indices changed notably between distribution networks of different treatment plants, which enabled the identification of changing water sources. A comparison of DOM in the direct and secondary water supplies suggested limited impacts of secondary water supply, although the changes in organic carbon and absorption indices were detected in some locations. These results have implications for better understanding the changes of DOM in the whole water supply system to help ensure the supplied water quality.
摘要：
溶解性有机物（DOM）在确定饮用水处理和供水质量方面很重要。然而,缺乏对整个供水系统的全面DOM研究，二次供水的潜在影响在很大程度上是未知的。这是使用溶解有机碳(DOC)研究的，吸收光谱学,和荧光激发-发射矩阵-平行因子分析(EEM-PARAFAC)。确定了四种荧光成分，包括腐殖质样C1-C2、色氨酸样C3和酪氨酸样C4。在饮用水处理厂，使用臭氧和生物活性炭（O3-BAC）的深度处理比常规工艺更有效地去除DOC，C1和C3的去除分别提高了17.7%-25.1%和19.2%-27.0%。水处理中吸收系数和C1-C4与DOC显著相关，表明吸收和荧光可以有效地跟踪体DOM的变化。DOM在每个饮用水分配系统中通常保持稳定，表明处理后的水质在确定相应网络中的重要性。不同处理厂的分配网络之间的光学指数发生了显著变化，这使得能够识别变化的水源。直接供水和二次供水中DOM的比较表明二次供水的影响有限，尽管在某些地方检测到有机碳和吸收指数的变化。这些结果对于更好地了解整个供水系统中DOM的变化，以帮助确保供水水质具有重要意义。
