紫外激活过硫酸盐降解莠灭净的动力学研究

采用紫外（UV）激活过硫酸盐（PS）氧化降解水中莠灭净（AMT）.比较了单独UV和UV/PS两种工艺的降解效果和经济性，并考察了底物初始浓度、PS投加量以及反应初始pH值3个因素对UV/PS去除AMT动力学的影响.同时采用间接法对反应中生成的主要自由基进行了鉴定.结果表明：UV/PS比单独UV系统降解AMT更经济有效.AMT降解过程符合准一级动力学模型（R²≥0.95），随着底物浓度的增加，准一级反应速率常数kobs逐渐减小；kobs随PS投加量的增加逐渐增大；控制pH为5~10时，kobs逐渐减小，pH值为5时，kobs达到最大值，为0.0540min-1；pH为7时反应中主要生成的自由基为·SO₄^-.

Kinetic study of ametryn degradation by UV activated persulfate

The degradation of the ametryn (AMT) by means of UV/Persulfate (PS) was investigated.The effect of degradation and economical efficiency were compared between UV and UV/PS, while emphasis was given on the effect of initial substrate concentration, PS dosage, and initial pH for the kinetics of AMT degradation by UV/PS. The main radical generated in the reaction were identified using the indirect method. The results showed that degradation of AMT by UV/PS was more cost-effective than UV alone . AMT degradation follows the first-order kinetic well (R²≥0.95), the persudo-first-order-constant kobs decreases with the increase of AMT concentration;the value of kobs was magnified gradually with the increasing PS dosage; controlling the pH of 5~10, kobs reaches the top of 0.0540min-1when pH=5; the main radical generated is ·SO₄^- when pH=7.