光催化氧化法降解有机磷农药的动力学研究

目的]进一步对有机磷敌敌畏农药光催化降解的反应动力学进行研究。方法]采用Sol-gel法在玻璃圆形反应器上镀制了TiO2膜,以紫外/二氧化钛膜(UV/TiO2)光催化氧化法来降解有机磷农药敌敌畏溶液,探讨了光催化反应时间、溶液的初始浓度对降解敌敌畏溶液的影响。结果]由玻璃筒负载的TiO2膜对单一的敌敌畏溶液具有很好的光催化降解效果,TiO2膜具有很好的光催化活性。敌敌畏溶液的初始浓度越低,光催化降解效果越好,经90 min光催化氧化处理后,不同浓度敌敌畏的降解率都能达到90%以上。动力学研究表明,敌敌畏的降解速率对敌敌畏浓度为一级反应,反应速率方程为:Ct=C0e-0.0719t(mg/L)。结论]光催化降解有机磷农药敌敌畏溶液具有很好的降解效果。

Kinetic Study on Degradation of Organophosphorus Pesticides by Photo-catalytic Oxidation

Objective] A further study on the kinetics of organophosphorus pesticide dichlorvos degradated by photo-catalytic oxidation was made.Method] The TiO2 film being prepared on glass-reactor with sol-gel method,UV/TiO2 photo-catalytic oxidation was applied to degrade the organophosphorus pesticide dichlorvos.The effects of some factors such as the photo-catalysis time,initial concentration of solution on the degradation of dichlorvos were discussed.Result] The TiO2 film loaded by grass had good photo-catalytic degradation effect on single dichlorvos solution and the TiO2 film had good photo-catalysis activity.The photo-catalytic degradation effect was better when the initial concn.of dichlorvos solution was lower.The degradation rate of dichlorvos at different concn.could reach above 90% after the dichlorvos was treated with photo-catalytic oxidation for 90 min.The kinetic study showed that the reaction between degradation rate of dichlorvos and its concn.was first order reaction and the reaction rate equation was Ct=C0e-0.071 9 t(mg/L).Conclusion] The degradation of organophosphorus Pesticide dichlorvos by photo-catalytic oxidation had good effect.