饮用水中内分泌干扰物阿特拉津UV光氧化研究

Degradation of Endocrine Disruptor Atrazine in Drinking Water by UV Radiation

采用单独紫外光氧化工艺去除饮用水中低浓度阿特拉津,研究了不同影响因素对阿特拉津降解效果的影响,并分析了阿特拉津的降解机理.结果表明:单独紫外光氧化对阿特拉津有很好的去除效果,在光强为205μW/cm2条件下,光解120min后,阿特拉津去除率为92.38%.阿特拉津的光解过程符合一级反应动力学模型.通过提高紫外照射光强,可以在短时间内提高阿特拉津的去除率.阿特拉津的初始浓度对光解反应基本没有影响.自来水中的有机物及多种离子的存在会降低阿特拉津的光解速率.紫外光氧化阿特拉津主要降解途径是脱氯反应,反应速率很快.羟基化产物(OHA)是主要的中间产物.OHA在紫外光作用下可以继续发生脱烷基反应,生成OHDIA和OHDEA,反应速率非常缓慢.反应液中pH值的变化与中间产物的形成过程有很好的相关性.

The degradation of atrazine with low concentration in drinking water by UV radiation was studied. The main influencing factors and degradation mechanism of this technology were discussed. Experimental results show that the photolytic degradation of atrazine by UV radiation alone is very efficient. Under 205 μW/cm2 irradiation intensity, atrazine removal ratio is 92.38 96 after 120 minutes. The rate of photodecomposition in aqueous solution follows first-order kinetics. The removal ratio of atrazine can be greatly enhanced by increasing the intensity of UV radiation. The initial concentration of atrazine has no effect on the oxidation reaction. The organic matter and various ion in tap water will decrease the degradation rate. The primary degradation pathway is dechlorination. The reaction rate is high. The hydroxylated compound is the major intermediate product. Hydroyatrazine can be further decomposed by UV radiation and form dealkylated derivatives. But the rate of dealkylated reaction is very low. There is intimate relationship between the change of pH in the solution and the formation of intermediate products.