臭氧降解水中痕量阿特拉津实验研究

An experimental study on ozone degradation of trace Atrazine in water

在磷酸盐缓冲液(PhosphateBuffer,PB)中考察了不同反应条件下臭氧(O3)降解阿特拉津(Atrazine,ATZ)的效果并对其氧化降解机理及氧化动力学进行探讨。结果表明,在pH7的PB中,恒温水浴20℃,ATZ、O3初始浓度分别为2.5、20μmol/L,反应时长20min时,O3对ATZ的降解率可达93%。机理分析表明,在O3降解ATZ过程中磷酸盐具有很好的缓冲效果且对O3分解无不良影响。反应体系pH值对O3降解ATZ有显著影响,在弱酸性条件下以直接氧化降解为主,氧化效果较弱;在弱碱性条件下以HO·氧化降解为主,氧化效果较强。动力学分析表明,O3降解ATZ动力学更为符合拟二级反应动力学。

The degradation of Atrazine (ATZ) by ozone (O 3) under different reaction conditions was investigated in Phosphate Buffer (PB). The oxidative degradation mechanism and oxidation kinetics were discussed. The results showed that in the PB of pH 7, the initial concentration of ATZ and O 3 was 2.5 and 20 μmol/L in the constant temperature water bath at 20°C, and the degradation rate of ATZ by O 3 was 93% in the reaction time of 20 min. The mechanism analysis showed that phosphate had a good buffering effect and no adverse effect on O 3 decomposition during O 3 degrading ATZ. The pH value of the reaction system has a significant effect on the degradation of ATZ by O 3. Under weakly acidic conditions, the direct oxidation degradation is dominant, and the oxidation effect is weak. Under weak alkaline conditions, HO·oxidative degradation is dominant, and the oxidation effect is stronger. Kinetic analysis showed that O 3 degrading ATZ kinetics was more consistent with pseudo-secondary reaction kinetics.