[1]张欣然,董双石,翟家欣,等.紫外/氯胺工艺中含氮消毒副产物的生成机制解析[J].中国给水排水,2023,39(5):31-37.
ZHANGXin-ran,DONGShuang-shi,ZHAIJia-xin,et al.Formation Mechanisms of Nitrogenous Disinfection By-products in UV/Chloramine Process[J].China Water & Wastewater,2023,39(5):31-37.
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ZHANGXin-ran,DONGShuang-shi,ZHAIJia-xin,et al.Formation Mechanisms of Nitrogenous Disinfection By-products in UV/Chloramine Process[J].China Water & Wastewater,2023,39(5):31-37.
紫外/氯胺工艺中含氮消毒副产物的生成机制解析
中国给水排水[ISSN:1000-4062/CN:12-1073/TU]
卷:
第39卷
期数:
2023年第5期
页码:
31-37
栏目:
出版日期:
2023-03-01
- Title:
- Formation Mechanisms of Nitrogenous Disinfection By-products in UV/Chloramine Process
- Keywords:
- UV/chloramine process; nitrogenous disinfection by-product; nitrogen isotope tracer; dichloroacetonitrile
- 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(15N)溯源分析表明,紫外/氯胺体系处理氨基酸时生成的15N-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。
- Abstract:
- 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 (15N) tracing showed that the 15N-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.
更新日期/Last Update:
2023-03-01