新型溴代苯酚类消毒副产物的氯化降解机制

发布时间：2018-06-20 00:30

本文选题：消毒副产物 + 苯酚类消毒副产物　；参考：《环境科学》2017年08期

【摘要】：最近,13种新型极性卤代苯酚类消毒副产物在氯化消毒后的饮用水中被发现,它们按结构被分成4组,分别是二卤-4-羟基苯甲醛、二卤-4-羟基苯甲酸、二卤水杨酸和三卤苯酚.为研究它们在氯化消毒过程中的降解机制,选取了其中的4种全溴代种类,即3,5-二溴-4-羟基苯甲醛、3,5-二溴-4-羟基苯甲酸、3,5-二溴水杨酸以及2,4,6-三溴苯酚,利用UPLC/ESI-tq MS中的前体离子扫描,多反应监测和子离子扫描,鉴定了这几种消毒副产物在氯化消毒过程中的中间产物以及终产物,并根据这些中间产物和终产物与消毒时间的关系推测了其降解路径.结果表明,除了3,5-二溴水杨酸相对较稳定外,其余3种消毒副产物在氯化消毒过程中不稳定,通过取代、水解以及氧化等过程最终降解为卤乙酸等脂肪族小分子消毒副产物.在降解过程中有许多中间产物被检测并鉴定出来,其中包含一组具有五元环结构的新型消毒副产物(三卤代-羟基环戊烯二酮).
[Abstract]:Recently, 13 new halogenated phenol by-products were found in chlorinated drinking water. They were divided into 4 groups according to their structure: dihalogen-4-hydroxybenzaldehyde, dihalogen-4-hydroxybenzoic acid, dihalosalicylic acid and trihalophenol. In order to study their degradation mechanism in chlorination disinfection, four kinds of total brominated species were selected, that is, 3o 5- dibromo-4hydroxybenzaldehyde, 3o 5- dibromo-4- hydroxy benzoic acid, 3o-5- dibromo-salicylic acid and 2chl4 dibromo-6- tribromophenol, respectively. Using precursor ion scanning, multi-reaction monitoring and sub-ion scanning in UPLC / ESI-tq MS, the intermediate and final products of these disinfection by-products during chlorination were identified. According to the relationship between these intermediates and final products and disinfection time, the degradation pathway was deduced. The results showed that the other three disinfection by-products were unstable in the chlorination process except for the relative stability of 3-bromo-5-dibromo-salicylic acid. The disinfection by-products of aliphatic groups such as haloacetic acid and other small aliphatic molecules were degraded by substitution hydrolysis and oxidation. A number of intermediate products were detected and identified during the degradation process, including a group of new disinfection by-products (trihalo-hydroxy cyclopentenedione) with a five-member ring structure.
【作者单位】：南京大学环境学院污染控制与资源化研究国家重点实验室;
【基金】：国家自然科学基金项目(51438008,51408296) 江苏省自然科学基金项目(BK20140607)
【分类号】：TU991.25

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