介质阻挡放电对水中敌草隆的降解研究

DIELECTRIC BARRIER DISCHARGE INDUCED DEGRADATION OF DIURON IN AQUEOUS SOLUTION

采用介质阻挡放电方法降解水溶液中的敌草隆,对影响敌草隆降解的因素进行了研究,并初步探讨了其降解动力学.结果表明,提高放电功率、减小介质层厚度和减小放电间距均能提高敌草隆的降解率,酸性条件下更有利于敌草隆的降解.相同实验条件下敌草隆初始浓度的升高会导致其降解率降低.添加不同种类的金属离子(Fe2+,Fe3+,Cu2+)均能提高敌草隆的降解率,不同金属离子在投加量为30mg·l-1时,敌草隆降解率提高量的大小顺序为:Fe2+>Fe3+>Cu2+.自由基清除剂(叔丁醇、异丙醇、碳酸钠)的加入抑制了敌草隆的降解.敌草隆在介质阻挡放电反应器中的降解符合一级反应动力学.

Degradation of Diuron in aqueous solution was conducted in a dielectric barrier discharge reactor. The factors that affect the degradation efficiency and degradation kinetics were examined. The results showed that the degradation efficiency of Diuron increased with increasing input power, reducing the dielectric thickness and reducing discharge gap. Acidic solution condition was favourable to Diuron degradation. The degradation rates of Diuron decreased with increasing initial Diuron concentration under the same experimental conditions. The degradation efficiency of Diuron increased dramatically with the adding of metal ion （ Fe^2＋ , Fe^3＋ , Cu^2＋ ）, and the degradation efficiency enhancement was Fe^2＋ 〉 Fe^3＋ 〉 Cu^2＋ at metal ion concentration of 30 mg· 1^-1. The radical scavengers had a strong inhibition effect on Diuron degradation, at the same time, the degradation of Diuron by dielectric barrier discharge could be depicted by first-order reaction kinetics.