芳香族碘代消毒副产物在氯或氯胺作用下的转化与分解

Most recently, a new category of disinfection byproducts (DBPs) with relatively high toxicity, namely aromatic iodinated DBPs, have been detected in disinfected drinking waters as well as wastewater effluents. However, in previous studies, the study of aromatic iodinated DBPs focused on their detection, identification and toxicity tests, while few studies have been carried out to investigate the other aspects of aromatic iodinated DBPs. The objective of this project is to investigate the transformation and decomposition of aromatic iodinated DBPs in the presence of disinfectants, including chlorine and monochloramine. Generally, the transformation pathways and decomposition kinetics of aromatic iodinated DBPs in the presence of chlorine or monochloramine will be investigated, the effects of different factors on the transformation and decomposition of aromatic iodinated DBPs in the presence of chlorine or monochloramine will be studied, and the overall toxicity of waters before and after the transformation and decomposition of aromatic iodinated DBPs will be examined. With the experimental results in this project, it is anticipated that the transformation and decomposition of aromatic iodinated DBPs in the presence of chlorine or monochloramine will be illustrated, and the overall toxicity of waters before and after the transformation and decomposition of aromatic iodinated DBPs will be clarified; the black box from the input of “organic matter + iodide + chlorine/monochloramine” through the output of “iodo-trihalomethanes + iodo-haloacetic acids” and “nitrogenous iodinated DBPs” will be opened to a significant extent; the change of iodinated DBPs and the overall toxicity change of tap water in the distribution systems will be clarified, and some scientific suggestions will be provided for the control of iodinated DBPs during disinfection of drinking waters and wastewater effluents.

近年来，研究发现了一类高毒性的新型消毒副产物，即芳香族碘代消毒副产物。而迄今为止，除了少量对芳香族碘代消毒副产物的检测、鉴定和毒性研究外鲜有其它相关报道。本项目拟对芳香族碘代消毒副产物在消毒剂氯或氯胺作用下的转化与分解过程进行研究，包括芳香族碘代消毒副产物在氯或氯胺作用下的转化路径，分解动力学，影响因素，及转化前后的毒性变化情况。通过本项目的研究，拟实现对芳香族碘代消毒副产物在氯或氯胺作用下的转化与分解过程的完整解析，并阐明该过程所引起的水样毒性变化，从而对自来水输水管网中碘代消毒副产物的变化以及由此引起的对人类的健康风险进行科学解析，为饮用水和污水消毒过程中碘代消毒副产物的控制以及消毒过程的优化提供有效的科学建议；并试图从芳香族碘代消毒副产物在消毒剂作用下的转化与分解着手，部分揭开从“有机质+碘离子+氯/氯胺”开始到消毒副产物“碘代三卤甲烷+碘代卤乙酸”和“含氮碘代消毒副产物”生成的黑匣子。

芳香族碘代消毒副产物是一类高毒性的新型消毒副产物，而它们也是消毒过程中产生的重要中间产物，会进一步与消毒剂发生反应生成其它种类的消毒副产物。本研究对芳香族碘代消毒副产物在氯胺作用下的转化过程进行了探索。首先建立了水中极性碘代消毒副产物的全面分析方法，包括除氯剂的选取，前处理及检测方法的建立与优化。经过对多种除氯剂的效应及其适用范围的评估，选定抗坏血酸为最适用于极性碘代消毒副产物分析的除氯剂；基于液液萃取法的局限性，建立了一种新的固相萃取前处理-液质测定的分析方法，可实现对极性碘代消毒副产物的快速准确定量分析。对芳香族碘代消毒副产物在氯胺作用下的转化过程进行了详细解析，包括芳香族碘代消毒副产物相互之间的转化以及芳香族碘代消毒副产物向脂肪族碘代消毒副产物的转化。首次发现芳香族碘代消毒副产物在氯胺作用下可发生相互之间的转化，并对其转化产物，转化路径，转化动力学，影响因素及毒性变化进行了系统研究，阐明了一碘代苯酚在氯胺作用下向三碘代苯酚和二碘代硝基苯酚的转化过程；且进一步的研究发现芳香族碘代消毒副产物在氯胺作用下会以碘代苯醌为中间体发生苯环的断裂，进而生成脂肪族碘代消毒副产物，包括碘代三卤甲烷和碘代卤乙酸。研究重点阐明了芳香族碘代消毒副产物在氯胺作用下的转化产物，转化路径，转化动力学，影响因素及毒性变化，全面解析了此类新型消毒副产物在消毒剂氯胺作用下的转化特征，为阐明芳香族碘代消毒副产物在消毒过程和输水管网中的变化情况提供了重要的理论依据。