苯线磷在表面土壤中的光催化降解研究

Study on Photodegradation of Fenamiphos in Surface Soil

以太阳为光源研究了TiO2量、苯线磷初始质量比、土壤厚度对苯线磷在土壤中光解行为的影响.结果表明:苯线磷的光解符合准一级动力学方程,且随添加TiO2用量从0mg·kg-1增加到200mg·kg-1,苯线磷的一级光解动力学常数也增大,其中最快的降解速率是最慢的1.51倍.在含有TiO2的土壤中,添加质量比相对较低的情况下,苯线磷的降解较快;苯线磷在不同厚度土壤中的光解速率不同,土壤厚度较大的情况下,苯线磷的半衰期也比较大.

The factors including the amount of TiO2 , the initial concentration of fenamiphos, soil thickness and their effect on photolysis of fenamiphos in the soil were studied by using TiO2 as the catalyst under natural sunlight. The results showed that the photodegradation of fenamiphos was fitted significantly into the quasi-first-order kinetic equation. The rate constant of photodegradation increased from 0. 006 7 h^-1 to 0. 010 1 h^-1 with the increasing of TiO2 amount from 0 mg·kg^-1 to 200 mg·kg^-1 ,and the fastest photodegradation rate reached 1.51 times compared to the slowest. The degradation rate of fenamiphos increased with decreasing of the initial concentration. The half-life of fenamiphos increased with increasing of soil thickness.