阿特拉津在紫外-氯消毒中的转化特性及机理研究

采用紫外-氯消毒技术去除水中的农药类内分泌干扰物阿特拉津，利用高效液相色谱（HPLC）测定水中阿特拉津残留浓度，并以液相-质谱联用（LC-MS、LC-MS/MS）技术鉴定其消毒副产物。结果表明，紫外-氯联合消毒技术能有效去除水中的阿特拉津。阿特拉津在紫外消毒过程中迅速降解，主要表现为脱氯羟基化作用，主要产物为2-羟基-4-乙胺基-6-异丙胺基-1，3，5-三氮苯（OIET），次要反应为氨基侧链脱烷基、氧化以及脱水成烯反应。后续加氯过程对阿特拉津及其主要产物没有明显的去除效果，但能有效去除乙烯胺类产物，且不明显引入消毒副产物，是一种安全有效的水处理工艺。

Conversion Characteristics and Mechanism of Atrazine in a Combination of UV and Chlorination

The technique of UV（254 nm） combined chlorination was used to remove endocrine disruptor atrazine in water. The variation of atrazine was conducted by HPLC and HPLC-MS/MS techniques. The results indicated that the technique of UV-Cl was an effective disinfection method. During UV disinfection process, 53.5% atrazine was decomposed in 10 min, and after 30 min, the removal efficiency was more than 90%. The photodegradation of atrazine followed the first order and its kinetic constant was 0.085 5 min^-1. Atrazine was decomposed primarily by dechlorohydroxylation and its main disinfection product was 2-hydroxy-4-acetamido -6-ethylamino-s-triazine（OIET）, which was obtained either from a hemolytic cleavage of the C-Cl bond followed by an electron transfer from the carbon to the chlorine radicals processed by the carbocation reaction with water, or the heterolytic cleavage of the excited state atrazine molecule which was favored by polar solvents such as water. In addition, there were other three groups products detected synchronously at a small amount： （1）dealkylated products such as 2-chloro--4-ethylamino-6-amino-s-triazine（CEAT）, 2-methoxy-4-methylamino-6-isopropylamino-s-triazine（OIMT）, etc, resulted from dealkylated reaction of amino groups, （2）oxidated products represented by 2-hydroxy-4-acetamindo-6-isopropylamino-s-triazine （ODIT）, etc, were from the attack of · OH radical, and （3）olefinated products including 2-chloro-4,6-divinylamino-s-triazine （CVVT）, 2-hydroxy-4-vinylamino-6- amino-s-triazine（OVAT）, 2-hydroxy-4-vinylamino-6 ethylamino-s-triazine（OVET）, etc, arised from the dehydrated-olefinated process. The subsequent chlorination could not effectively remove atrazine and its main photodegradation products except dehydrated-olefinated products such as OVET, OVAT, etc, and there was no more disinfection products appeared. So UV-Cl disinfection was proved to be an effective and safe water treatment technique.