紫外/氯胺工艺中含氮消毒副产物的生成机制解析  

Formation Mechanisms of Nitrogenous Disinfection By‑products in UV/Chloramine Process

作　　者：张欣然[1,2,3] 董双石 翟家欣[4] 任鹏飞 ZHANG Xin‑ran;DONG Shuang‑shi;ZHAI Jia‑xin;REN Peng‑fei(Key Laboratory of Groundwater Resources and Environment,Jilin University,Changchun 130021,China;School of Environmental Science and Engineering,Sun Yat‑sen University,Guangzhou 510275,China;Shenzhen Research Institute of Sun Yat‑sen University,Shenzhen 518000,China;Guangzhou Research Institute of Environmental Protection,Guangzhou 510620,China;Guangzhou Municipal Engineering Design&Research Institute,Guangzhou 510001,China)

机构地区：[1]吉林大学地下水资源与环境教育部重点实验室,吉林长春130021 [2]中山大学环境科学与工程学院,广东广州510275 [3]中山大学深圳研究院,广东深圳518000 [4]广州市环境保护科学研究院,广东广州510620 [5]广州市市政工程设计研究总院有限公司,广东广州510001

出　　处：《中国给水排水》2023年第5期31-37,共7页China Water & Wastewater

基　　金：深圳市科技计划项目(JCYJ20210324140812034);国家自然科学基金资助项目(51808156);地下水资源与环境教育部重点实验室开放课题(202005005KF);广东省基础与应用基础研究基金资助项目(2019A1515011664);中央高校基本科研业务费专项(20lgzd22)。

摘　　要：针对紫外/氯胺工艺在水处理过程中存在的高毒性含氮消毒副产物生成风险,考察了典型含氮消毒副产物二氯乙腈的生成行为和机制,并提出了控制策略。结果表明,相比单独氯胺体系,紫外/氯胺体系可使3种氨基酸的二氯乙腈生成量下降26.6%~46.7%,但会显著促进15种酚类物质的二氯乙腈生成势;两种工艺中3种腐殖质的二氯乙腈生成量基本相当。氮同位素(^(15)N)溯源分析表明,紫外/氯胺体系处理氨基酸时生成的^(15)N-二氯乙腈占总二氯乙腈的70%以上,说明氯胺是二氯乙腈的重要氮源,而非水中含氮有机质;并证明了紫外/氯胺体系中的二氯乙腈主要通过“醛途径”生成。以酪氨酸为例,鉴定得到了一系列醛类和腈类中间产物,进而解析了紫外/氯胺体系中二氯乙腈的生成路径。在紫外/氯胺工艺的实际工程应用中,建议对酚含量较高的水体进行预处理,并尽量延长紫外/氯胺处理时间、缩短后氯胺接触时间、调节pH为碱性条件,以减少二氯乙腈的生成。In view of the high toxicity of nitrogenous disinfection by‑products in UV/chloramine process,the formation behavior and mechanism of dichloroacetonitrile(a typical nitrogenous disinfection by‑product)was investigated,and the control strategy was proposed.Compared with chloramine system,the UV/chloramine system reduced the dichloroacetonitrile production of three amino acids by 26.6%-46.7%,but significantly promoted the dichloroacetonitrile production of fifteen phenolic substances.The dichloroacetonitrile production of three humic substances in the two processes was basically the same.The nitrogen isotope(^(15)N)tracing showed that the ^(15)N‑dichloroacetonitrile formed in the UV/chloramine system accounted for more than 70%of the total dichloroacetonitrile during the treatment of three amino acids,indicating that chloramine was an important precursor of dichloroacetonitrile,rather than nitrogenous organics in water.The results also proved that dichloroacetonitrile in the UV/chloramine system was mainly produced through the“aldehyde pathway”.A series of aldehyde and nitrile intermediates were identified by using tyrosine as a representative compound,and then the formation pathway of dichloroacetonitrile in UV/chloramine system was analyzed.In the practical engineering application of UV/chloramine process,it is recommended to pretreat the water with high phenol content,prolong the reaction time as far as possible,shorten the contact time of post‑chloramination and adjust the pH to alkaline condition,so as to reduce the formation of dichloroacetonitrile.

关 键 词：紫外/氯胺工艺 含氮消毒副产物 氮同位素示踪 二氯乙腈 

分 类 号：TU991[建筑科学—市政工程]