表层土添加TiO_2与土壤厚度对多菌灵光解的影响

Effect of Addition of TiO_2 and the Thickness of Surface Soil on Photodegradation of Carbendazim Therein

以太阳光为光源,研究了TiO2用量、土壤厚度对多菌灵在土壤中的光解行为的影响。结果表明:多菌灵的光解符合准一级动力学方程,随添加TiO2用量从0增至200 mg.kg-1,多菌灵的一级光解动力学常数也增大,且2者的线性相关系数为0.962,其中最快的降解速率是最慢的2.85倍。在含有TiO2的土壤中,多菌灵在不同厚度土壤中的光解速率不同,土壤厚度较大情况下,多菌灵半衰期也较大。

Effects of some factors, like amount of TiO2 added as the catalyst, initial concentration of carbendazim, thickness of the surface soil on photolysis of carbendazim therein were studied under natural sunlight. Results show that photodegradation of earbendazim fitted the quasi-first-order kinetic equation. The constant of the equation increased from 0. 015 8 to 0. 045 h h^-1 with increasing TiO2 rate from 0 to 200 mg . kg^-1 , showing significant linear correlation （ r = 0. 962） , and the highest photodegradation rate reached 2.85 times as much as the slowest. The half-life of carhendazim increased with the increasing of soil thickness.