水源水中天然有机物组分解析及其在饮用水处理工艺中的行为研究

Natural organic matter (NOM) is a heterogeneous mixture of complex organic matter and occurs ubiquitously in source water. NOM has a strong implication with water supply. It may not only negatively affects the performance of water treatment processes，but also react with disinfectants such as chlorine to form a variety of harmful disinfection byproducts (DBPs) during disinfection of drinking water. In addition, NOM may promote undesired microbial growth in water distribution systems. Thus, control and removal of NOM is of particular importance for the water treatment industry. However, due to the extremely complex nature of NOM, the molecular compositions and treatability of NOM in different water treatment processes are still not well known. In addition, the increasing amount and variability of NOM concentrations and compositions due to climate change and anthropogenic activity represents severe challenges for control and removal of NOM in water treatment and distribution systems. The objectives of this study are to characterize the major molecular compositions and their seasonal variation of NOM in typical source waters in different regions of China and to investigate the treatability of major molecular compositions of NOM in coagulation/flocculation, ozonation, and chlorination. "Fingerprints" characterization method based on fluorescence excitation/emission matrix (EEM) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) will be established and applied to characterize the molecular compositions of NOM. In addition, the treatability of major molecular compositions of NOM will be investigated through laboratory scale experiments. Results of this study will improve our knowledge on the molecular composition, variation, and treatability of NOM in source waters, and provide useful information for control of NOM and DBPs in drinking water.

水源水中天然有机物（Natural Organic Matter, NOM）的存在不但可能影响饮用水处理工艺的效率、增加处理成本，而且会在消毒工艺中与消毒剂反应生成具有致癌性的消毒副产物。同时NOM还是输水管网中微生物生长的重要碳源。因此NOM的去除和控制一直是水处理行业关注的重要问题。NOM的分子组成极其复杂，不同的组成分子在水处理工艺中的行为也有所不同，但目前对水源水中NOM的分子组成及其处理行为的认识仍然非常有限。气候变化和人类活动的影响进一步增加了水源水NOM分子组成的复杂性，给水处理中NOM的去除和控制带来了新的挑战。本研究将通过建立水源水中NOM主要分子组成的指纹图谱分析方法，结合实验室不同处理工艺模拟实验，揭示我国不同流域典型水源水中NOM的主要分子组成、动态变化及其在不同处理工艺中的行为，为饮用水处理过程NOM及消毒副产物的去除和控制提供方法学和理论基础。

水中溶解性有机物是一类来源于天然源和人类活动源的有机物混合物，其广泛存在于水体环境中，组成十分复杂。饮用水中的溶解性有机物会影响饮用水处理过程的各个工艺，尤其是在饮用水消毒工艺中与消毒剂发生反应，生成具有致癌性的消毒副产物。探明溶解性有机物在水处理过程中，尤其是氯消毒中的转化规律对保障饮用水安全具有重要科学意义。本研究对我国不同饮用水溶解性有机物的分子组成及其在饮用水氯消毒工艺中的转化规律进行了研究。发现我国不同地区饮用水水源中天然有机物的组成分子既有共性也有差异性，其中木质素、丹宁类分子在各地水源中普遍存在。不同水源中溶解性有机物在氯消毒过程中生成的三卤甲烷和卤乙酸类消毒副产物生成势与溶解性有机物组成密切相关，氧碳比高，不饱和度高的分子式消毒副产物的主要前体物。同时，本研究对新型卤代苯醌类消毒副产物在不同水源饮用水中生成的浓度水平进行了研究，发现在长江下游、黄河下游、辽河下游、海河下游等的8个饮用水出水中2,6-二氯-1,4-苯醌均有检出，浓度水平在8-36ng/L之间。进一步对卤代苯醌类消毒副产物毒性评价的研究显示，卤代苯醌类消毒副产物均具有细胞毒性和遗传毒性。