Degradation of tertiary alkylamines during chlorination/chloramination: Implications for formation of aldehydes, nitriles, halonitroalkanes, and nitrosamines
Degradation of tertiary alkylamines during chlorination/chloramination: Implications for formation of aldehydes, nitriles, halonitroalkanes, and nitrosamines
复制标题
DOI：
10.1021/es703017z
复制
发表时间：
2008-07-01
影响因子：
11.4
通讯作者：
Schreiber, I. Marie
中科院分区：
文献类型：
--
作者：
Mitch, William A.;Schreiber, I. Marie
饮用水公用事业正在探索利用受废水排放和农业径流影响的沃茨来满足不断增长的人口的需求。由于这些沃茨中有机氮浓度升高，氯和氯胺消毒过程中有机氮转化为有毒含氮消毒副产物的途径是当前关注的问题。叔烷基胺是人类排泄物和各种消费品中的重要官能团，可通过废水排放物释放到饮用水供应中。我们研究了模型叔烷基胺在氯化和氯胺化过程中的降解途径。我们的研究结果表明，叔烷基胺降解几乎瞬间在氯化形成醛和仲烷基胺定量，没有显着的区域选择性。在氯胺化过程中也观察到类似的结果，但观察到的降解速率要慢得多，醛的产率较低。由于这些主要产物相当稳定，这些结果解释了为什么叔胺是仲亚硝胺在氯胺化过程中的重要前体。氯化过程中生成的三氯硝基甲烷产率很低，但在氯胺化过程中没有观察到;一氯硝基甲烷和二氯硝基甲烷从未被检测到。尽管在氯胺化过程中醛的产率很高，但我们的结果表明氯胺和醛之间的反应的腈产率很低。
Drinking water utilities are exploring the use of waters impacted by wastewater effluents and agricultural runoff to meet the demands of growing populations. Due to the elevated organic nitrogen concentrations in these waters, the pathways responsible for transformation of organic nitrogen into toxic nitrogenous disinfection byproducts during chlorine and chloramine disinfection are of current concern. Tertiary alkylamines are important functional groups in human waste products and various consumer products that can be released to drinking water supplies via wastewater effluents. We investigated degradation pathways for model tertiary alkylamines during chlorination and chloramination. Our results indicate that tertiary alkylamines degrade nearly instantaneously during chlorination to form aldehydes and secondary alkylamines quantitatively, with no significant regioselectivity. Similar results were observed during chloramination, but the observed degradation rates were much slower, with lower yields of aldehydes. As these major products were fairly stable, these results explain why tertiary amines are significant precursors of secondary nitrosamines during chloramination. Trichloronitromethane formed at very low yields during chlorination, but was not observed during chloramination; monochloronitromethane and dichloronitromethane were never detected. Despite the significant yields of aldehydes during chloramination, our results indicated low nitrile yields by the reaction between chloramines and aldehydes.