N-亚硝基二甲胺前体物在城市污水生物脱氮工艺中的去除与归趋机制

项目名称： N-亚硝基二甲胺前体物在城市污水生物脱氮工艺中的去除与归趋机制

项目编号： No.50878165

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 生物科学

项目作者： 李咏梅

作者单位： 同济大学

项目金额： 38万元

中文摘要： N-亚硝基二甲胺（NDMA）是最近发现的一种致癌性消毒副产物。NDMA前体物在城市污水生物处理系统中的去除与消毒过程中NDMA的形成密切相关。本课题建立了NDMA及其前体物的分析方法,调查了上海及周边地区6座污水厂中的NDMA及其前体物的存在与去除情况；在此基础上，考查了缺氧-好氧(AO)与厌氧-缺氧-好氧(AAO)系统中溶解性有机氮与NDMA前体物的去除，确定了最佳运行参数；研究了紫外与氯胺消毒过程中城市污水中NDMA及其总前体物的形成与去除情况，得出了有利于NDMA去除的紫外光解条件；研究了6种典型NDMA前体物(二甲胺、三甲胺、二甲基乙醇胺、二甲基氨基苯、二甲基甲酰胺，二甲基二硫代氨基甲酸钠)在AO与AAO系统中的生物降解，考察了水力停留时间和污泥龄对典型前体物去除及同时除磷脱氮的影响，推导了其生物降解的一级动力学模型。最后，对NDMA前体物降解菌种进行了分离鉴定，获得了优势菌种；研究了部分前体物的生物降解途径，发现某些含氮杂环有机物可能为NDMA前体物。以上研究成果对于在城市污水厂去除NDMA前体物，从源头控制NDMA的形成及其前体物的排放具有重要的理论和实践意义。

中文关键词： NDMA；NDMA前体物；消毒；生物降解；工艺参数

英文摘要： N-nitrosodimethylamine (NDMA) is a recently identified carcinogenic disinfection by-product. The removal of NDMA precursors in municipal wastewater treatment system is closely related the formation of NDMA during disinfection processes. In the present project, the analysis methods of NDMA and its precursors were first established, and then the occurrence and removal of NDMA and its precursors were investigated in 6 wastewater treatment plants (WWPTs) around Shanghai. Removals of dissolved organic nitrogen (DON) and NDMA precursors in anoxic-oxic (AO) and anaerobic-anoxic-oxic (AAO) systems were studied, and the optimal operational parameters were confirmed. The formation and removal of NDMA and its precursors during UV and chloramines disinfection were investigated and the effective UV condition was suggested. Biodegradation of 6 specific NDMA precursors (dimethylamine, trimethylamine, dimethylformamide, dimethylaminobenzene, N,N-dimethylethanolamine and N,N-dimethyldithiocarbamate) in AO and AAO systems was studied, and the effects of hydraulic retention time (HRT) and sludge retention time (SRT) were investigated. The first-order kinetics of the 6 specific NDMA precursors were suggested. At last, bacteria degrading the 6 specific NDMA precursors were isolated and identified. Biodegradation pathways of some NDMA precursors were investigated, and it was found that some nitrogenous heterocyclic compounds might be the NDMA precursors. The above results have important theretical and practical implications for the removal of NDMA precursors in WWPTs and the control of NDMA in the sources.

英文关键词： NDMA; NDMA precursor; disinfection; biodegradation; operational parameter