超声波/H_2O_2协同降解水中三唑磷的研究

Degradation of triazophos in aqueous solution by ultrasonic/H_2O_2 system

研究了超声波／H2O2联合处理对水模拟体系中有机磷农药三唑磷的去除效果，并分析了超声功率、农药初始浓度和溶液初始pH对三唑磷降解的影响。结果表明，超声波／H2O2联合处理对水模拟体系中的三唑磷具有良好的降解效果。在本实验研究条件下，与单独超声和H2O2处理相比，超声波／H2O2联合处理对三唑磷具有明显的协同降解作用；在超声功率为475～850W时，三唑磷的降解率随功率的上升而显著增加；在农药浓度为2～20mg／L的范围内，降低农药初始浓度有利于提高三唑磷的降解率；pH对三唑磷的降解有显著影响，且碱性条件更有利于三唑磷的降解。当溶液pH为9、三唑磷初始浓度为2．46mg/L、H2O2添加浓度为2．5g／L时，采用300W的超声波处理90min，三唑磷的降解率高达79．2％。动力学分析的结果表明，一级动力学模型能很好模拟超声波／H2O2联合处理作用下三唑磷的降解。

This study focused on the degradation of one of organophosphorus pesticides triazophos by an ultrasonic/H2O2 system and the factors including ultrasonic power,initial concentration of triazophos and pH value of aqueous solution on the degradation were investigated. Results indicated that the ultrasonic/H2O2 system was effective in the degradation of triazophos in aqueous solution and had a noticeable synergetic effect in the removal of triazophos compared with the single treatment of ultrasonic and H2O2. Furthermore,the degradation efficiency of triazophos was significantly improved as ultrasonic power increased from 475 W to 850 W. In addition,the degradation efficiency declined as the initial concentration of triazophos increased from 2 mg/L to 20 mg/L under ultrasonic/H2O2 treatment. It was also found that the degradation of triazophos was strongly pH-dependent and alkalinity condition favored the degradation. The degradation efficiency was 79.2% when the ultrasonic treatment was operated at 300 W for 90 min with pH value of 9 with the concentrations of triazophos and H2O2at 2.46 mg/L and 2.5 g/L,respectively. The degradation kinetics of triazophos was fitted to the first-order kinetics model well.