农药在光照土壤层的迁移和降解

The transport and degradation of pesticide on irradiated soil layers

光照条件下 ,农药在土壤层中的降解速率不仅决定于光解本身 ,而且还是土层厚度、迁移过程的函数 .为此 ,描述了理解这些不同过程复合效果的理论框架 ,提出了允许实际光解过程和扩散过程分离定量的实验方案 ,同时进行了除草剂苄嘧磺隆在不同厚度土壤中的光解实验 ,并用数学模型评价了实验结果 .实验中确定了苄嘧磺隆在土壤中的实际光解速率常数 ,这个常数是不依赖于迁移动力学的 .

On irradiated soil layers, the observed overall pesticide degradation rate is not only determined by photodegradation itself but is also a function of the layer thickness and in many cases of transport processes. In this article we describe a theoretical framework understand combined effects of these different processes, and we present an experimental setup that allows a separate quantification of actual photodegradation and diffusive transport processes. For the compound bensulfuron methyl we performed experiments on soil layers of variable thickness and evaluated the results using a mathematical model. Thus, we were able to determine the actual photodegradation rate constants that are independed of transport kinetics.