微囊藻次生嗅味类消毒副产物N-氯代亚胺的生成机制与控制机理研究

Period and sudden breakout of high-algae in raw water and its derived pollutants including microcystins, taste and odour(T&O) and extracellular organic matter(EOM) are hot topics recently. Especially, T&O caused by geosmin, 2-methylisoborneol, β-cyclocitral and dimethyl trisulfide which are released directly by algae is attract more and more attention of scholars, while not adequate efforts were engaged in secondary T&O pollutants produced by algae during chlorination and their evolution. This project firstly proposed researches focused on T&O chlorination byproducts of algae. In this project, based on chemical and sense analytical methods, T&O byproducts during chlorination of high-algae raw water named as N-chloraldimines are discriminated and indentified, pollution level of such kinds of compounds is investigated. Considering Microcystis derived pollutants as precursor, existing category, formation mechanism and transformation of N-chloraldimines are researched comprehensively, and also acute, mutagenic and genetic toxic effect are evaluated. To propose controlling techniques, different water treatment methods are compared and researched to reduce N-chloraldimines. Summarily, the project will help to analyze the influence of algae to potable water and provide technique references for management and control of emergency algae pollution.

原水中周期性、突发性高藻及其次生物土臭素、2-甲基异茨醇、?-环柠檬醛和二甲基三硫醚等导致的嗅味污染吸引了学者们的广泛关注，成为给水领域的热点问题，但对于消毒过程中藻类分泌物等次生物引发的二次嗅味污染物的迁移转化缺乏足够的研究。本课题率先提出了针对藻源性嗅味类消毒副产物N-氯代亚胺的相关研究，旨在化学分析和感官分析（FPA）相结合的基础上，对高藻原水经消毒过程产生的嗅味类消毒副产物N-氯代亚胺进行鉴定和识别，探明高藻期N-氯代亚胺污染状况，系统研究以微囊藻衍生污染为前体物的N-氯代亚胺的存在类型、产生机制和迁移转化规律，进行相应毒性评估，系统评价不同水处理技术对此类物质的去除效果，针对性的提出N-氯代亚胺控制技术方案，为进一步解析高藻对饮用水水质的影响及供水部门应对高藻衍生污染问题的管理和控制提供科学技术支撑。

饮用水中含氮消毒副产物（Nitrogenous disinfection byproducts, N-DBPs）由于具有比常规含碳消毒副产物（Carbonic disinfection byproducts, C-DBPs）可能更高的致畸致突变性而引发了广泛的关注。本课题围绕微囊藻次生的嗅味类含氮消毒副产物，展开了藻源性含氮前体物的识别，阐明了“微囊藻-含氮前体物-含氮消毒副产物”的源生关系；完成了主要消毒副产物的鉴定、产生途径解析及其嗅味特征等特性表达；调查了典型特征消毒副产物的水环境分布情况；同时考察了两种水处理工艺对典型含氮消毒副产物的控制效果。结果表明，水环境中微囊藻可释放氨基酸和蛋白质等溶解性含氮有机物，释放量分别可达0.023 pg/cell和2.56 pg/cell；氨基酸氯化消毒过程中可产生嗅味类含氮副产物N-氯代亚胺，但由于稳定性较差，最终转化为嗅味类含氮消毒副产物腈类物质；以苯丙氨酸典型消毒副产物苯乙腈为典型代表展开研究，发现该物质具有类似辛辣、苦杏仁的嗅味，在水环境中稳定存在，以氯为主要消毒剂的自来水样本中可广泛检出，检出含量高达10.7 μg/L；微囊藻为主的高藻原水中预氯化可形成“微囊藻-藻源苯丙氨酸-苯乙腈”的源生关系；活性炭吸附及UV-C/H2O2联用可较有效的去除水环境中的苯乙腈。.课题研究首次揭示了微囊藻与其衍生新型嗅味类含氮消毒副产物苯乙腈的必然联系，首次评价了自来水输水过程余氯存在情况下苯乙腈的稳定性，并广泛的调查了苯乙腈在以氯消毒为主的自来水中的含量水平，为饮用水消毒副产物的识别和控制提供了新的科学信息和理论支持。