饮用水氯（胺）化消毒衍生致嗅副产物的产生机制与控制方法

Chlor(am)ination process can not only produce the carcinogenic, teratogenic and mutagenic disinfection by-products (DBPs), but also lead to the formation of several odorous derivatives in drinking water. These chlor(am)inated odorous derivatives are closely related to the water characteristics and often ignored due to the interference of chlorine/chloramine odors. In fact, as an important part of TOX, these odorous derivatives have complicated structures and different odorous threshold in water. Their presence will influence the water quality and also have direct or indirect toxicity for human health. In order to minimize the risk of chlor(am)inated odorous derivatives in drinking water, this project will focus on the formation mechanism and control methods of these odorous derivatives, and the following main contents will be investigated: (1) to identify the chlor(am)inated organic odorous derivatives species and concentrations under different influence factors; (2) to investigate the formation and degradation kinetics of organic odorous derivatives, and find the important transformation pathways; (3) to explore the change rules of odorous derivatives precursors during drinking water treatment processes and the effects of disinfection methods on odorous derivatives formation, and find effective control technology; (4) to investigate the inorganic odors caused by disinfectants, and discover the transformation mechanism from low-odorous monochloramine to high-odorous dichloramine. As shown above, the reliable and integrated theory of chlor(am)inated odorous derivatives control in drinking water will be presented in this project.

饮用水氯（胺）消毒过程中不仅会产生“三致”的消毒副产物，也可生成多类型强致嗅的衍生物。由于其产生与水质密切相关，也常被消毒剂氯味掩盖，易被忽略存在。事实上，其结构复杂、嗅阈值差异大，是TOX的重要组成部分，在直接影响饮用品质的同时，也具有较强的直接或间接致毒作用。饮用水氯（胺）消毒衍生嗅味是本领域开始关注的重要水质问题，本项目将重点开展其生成控制理论研究。通过对衍生有机嗅味的识别与解析，获得不同水质条件下氯（胺）消毒衍生嗅味物质的组成规律，找出关键的致嗅因子；探索有机嗅味的产生与转变规律，掌握典型衍生有机嗅味的生成规律和动力学特征，获得重要转变途径；解析前体物在净水工艺中的变化规律，揭示消毒方式对衍生有机嗅味的生成影响，探索有效的末端控制技术；通过对消毒剂衍生无机嗅味的转变特性研究，揭示出厂水低嗅味一氯胺向高嗅味二氯胺转化的影响机制；最终为我国饮用水中消毒衍生嗅味的有效控制提供理论依据。

饮用水消毒衍生的嗅味主要包含有机嗅味和无机嗅味两大部分，其中有机嗅味主要通过氯（氯）与水中广泛存在的溶解性有机物反应生成，无机嗅味主要是消毒剂本身的嗅味。氯（胺）消毒衍生有机嗅味物质普遍具有一定的“三致”特性，同时也可继续转化成为高致毒性含氮和碘代消毒副产物等，从而对饮用水水质构成双重威胁。课题以饮用水消毒过程中衍生的嗅味物质的识别解析、生成机制、转变规律与风险削减为研究重点，系统性开展了氯（胺）化消毒后N-氯代亚胺、碘代三卤甲烷（I-THMs）和卤代苯甲醚等多类型衍生有机嗅味的识别与解析、典型氯（胺）衍生嗅味物质的生成与转化机制、常规和深度处理净水工艺中衍生嗅味物质生成风险控制、消毒剂衍生无机嗅味的变迁规律与调控等研究工作。课题建立了消毒剂自身无机嗅味与衍生有机嗅味共存条件下，多类型衍生有机嗅味的识别与解析方法，开展了不同浓缩富集手段、质谱条件等条件下衍生嗅味物质的检测方法优化；以有机嗅味前体物为研究对象，发现藻源有机物为致嗅物N-氯代亚胺的重要前体物；并研究了UV预处理对前体物和碘源的影响，以及后续氯胺化过程中致嗅物质I-THMs的生成机理，发现UV辐照会显著增强I-THMs的生成；针对浓度变化较大的N-氯代亚胺开展其稳定性研究，发现N-氯代亚胺的浓度变化方向主要是由自身衰减和氯化生成两方面共同作用导致，探明了氯（胺）化消毒过程有机嗅味物质的产生与变化机制及其反应动力学模型建立；明晰上海市水源水经氯（胺）化消毒后衍生的有机嗅味物质关键种类与浓度水平，探明了紫外/高级氧化工艺和活性炭吸附工艺去除衍生有机嗅味的技术方法；系统研究了饮用水一氯胺消毒过程中氯胺形态与嗅味特性的迁移转化规律，发现嗅味强度跟余氯形态密切相关，二氯胺和有机氯胺占比较高嗅味强度也更高。本课题的研究成果可以为我国饮用水消毒处理过程衍生嗅味问题的有效控制提供理论依据和技术支持。