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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).
Recently, 13 novel polar halogenated phenol disinfection by-products were found in chlorinated drinking water. They were divided into 4 groups by structure, namely dihalo-4-hydroxybenzaldehyde, dihalo-4- Hydroxybenzoic acid, dihalosalicylic acid and trihalophenol.In order to study their mechanism of degradation in the process of chlorination disinfection, four kinds of all-bromo species were selected, namely 3,5-dibromo-4-hydroxybenzaldehyde , 3,5-dibromo-4-hydroxybenzoic acid, 3,5-dibromosalicylic acid, and 2,4,6-tribromophenol, using a precursor ion scan in UPLC / ESI-tq MS, Monitoring and ion-scan, identified the intermediate and final products of these disinfection byproducts during the chlorination process, and deduced the degradation pathways according to the relationship between these intermediates and final products and the disinfection time.The results showed that in addition to 3 , 5-dibromosalicylic acid were relatively stable. The other three kinds of disinfection by-products were not stable in the process of chlorination. They were eventually degraded to aliphatic small molecule disinfection by-products such as haloacetic acid through substitution, hydrolysis and oxidation. During the degradation process there are many intermediate products were detected and identified, which contains a group with a five-membered ring structure New DBPs (trihalo - hydroxy-cyclopentene-dione).