4-6 清华大学2011毕业论文舒圆媛论文打印版

含甲胺基化合物的消毒副产物NDMA特性

与机理研究

清华大学环境学院给排水科学与工程2011届舒圆媛

指导教师：张晓健教授

摘要: N-亚硝基二甲胺（NDMA）由于其对人类健康潜在的巨大危害性已经成为饮用水安全领域研究的热点问题。弄清水体中哪些物质是NDMA的前体物，是研究该消毒副产物生成机理与控制技术的重要基础。已有文献报道，具有特定化学结构——如胺基的某些水处理药剂、农药等能显著生成NDMA，但已有研究在不同胺基结构对化学物质消毒生成NDMA的影响方面缺乏系统认识，并缺乏对其他含胺基官能团的物质消毒生成NDMA的研究。

本研究选取杀虫脒、抗蚜威、绿麦隆、氯化胆碱、聚二烯丙基二甲基氯化

铵、洁尔灭、十六烷基三甲基溴化铵等七种含甲基胺官能团的化学物质及酪氨

酸、赖氨酸和单宁酸进行氯胺、自由氯和二氧化氯消毒试验，识别具有较大

NDMA生成潜能的目标化合物和相应消毒剂。在此基础上，研究pH、消毒剂剂量和消毒剂接触时间对目标化合物与相应消毒剂反应生成NDMA的影响；研究不同物质与消毒剂反应生成NDMA的动力学；结合有机化学合成理论，提出含有不同胺基官能团结构的化学物质和消毒剂反应时可能的NDMA生成途径，为判别具有类似化学结构的环境物质在水处理过程中的NDMA生成风险和开发相应的控制技术提供理论依据。

本研究得出如下主要结论：

（1）含甲基胺官能团的化学物质是NDMA的重要前体物，但物质结构对

NDMA生成有重要影响。氯胺消毒时，聚二烯丙基二甲基氯化铵和杀虫脒有最大的NDMA生成潜能。

（2）消毒方式是所选物质生成NDMA的重要影响因素之一，在相同条件

下，氯胺消毒能产生比自由氯和二氧化氯消毒更多的NDMA。

（3）在氯胺消毒条件下，反应体系的pH值影响所选物质释放二甲胺

（DMA）及DMA进一步生成NDMA的反应。对绿麦隆和十六烷基三甲基溴

化铵的研究表明，pH越低，NDMA生成量越大。

（4）不同前体物释放DMA和生成NDMA的动力学特征由其物质结构决定。聚二烯丙基二甲基氯化铵具有最快的DMA释放速度。

（5）具有不同物质结构的前体物在氯胺消毒时生成NDMA的反应途径不同。季铵盐经过霍夫曼消除反应转化为三级胺；具有β-H结构的三级胺与氯胺作用生成亚胺从而释放DMA；具有羰基结构的三级胺通过自身水解释放DMA。

关键词：N-亚硝基二甲胺（NDMA）；前体物；甲基胺官能团；氯胺消毒

ABSTRACT

N-nitrosodimethylamine (NDMA) has been attracted more and more attention due to its strong toxicity to the humans. The identification of precursors of NDMA in the water treatment process is very important to probe the formation mechmism and develop the controlling technique of this chemical. Previous studies have reported that some water treatment chemical, pesticides that containing dimethylamine (DMA) functional group tended to produce high concentration of NDMA with chloramination. However, there few studies to assess how the structures of dimethylamine contained in the chemicals affect their NDMA formation during the treatment with disinftants, and reaction conditions affect the NDMA formation.

In this study, Chlordimeform (CD), Pirimicarb (Pi), chlortoluron (CT), 2-Hydroxyethyltrimethylammonium chloride (HMAC), Poly diallyl dimethyl ammonium chloride (PD), Benzalkonium Chloride (BKC), Hexadecyl trimethyl ammonium Bromide (HTAB) in which dimethylamine functional group was contained and L-Tyrosine, L-Lysine, Tannin in which dimethylamine functional group was not contained were disinfected with monochloramine, chlorine, chlorine dioxide to assess the formation of NDMA. The influence of pH, disinfectant dose, and contact time and the kinetics of DMA release from different precursors were investigated with chloramination. The NDMA formation pathways were proposed from different precursors. The main conclusions were as follows:

(1) The chemicals containing dimethylamine functional group tended to form NDMA, however, the structures of the dimethylamine functional group in the chemicals would play an impotant role of the formation of NDMA. PD showed the