Adsorption, degradation and leaching migration characteristics of chlorothalonil in different soils.

The adsorption, degradation and leaching characteristics of chlorothalonil in two representative soil were studied using simulated soil degradation and soil column leaching. The results showed that the adsorption of chlorothalonil in clay and sandy soil can be characterized by the Freundlich equation. The adsorption coefficient (K) was 6.7158 and 1.2568, respectively. Both soils were physical adsorption. The residual degradation kinetics of chlorothalonil in both soils met the first-order kinetics degradation equation. As the concentration of chlorothalonil increased, the higher the residual amount of chlorothalonil in the soil, the slower the degradation rate and the longer the half-life. In the soil column, chlorothalonil was not easy to move and migrate in the two soil columns. The highest residual residues were in the range of 0 to 10 cm (the topmost), and then a decrease in order. The correlation analysis showed that the adsorption and leaching of chlorothalonil in the two soils may be affected by a combination of factors such as soil organic matter content, clay content, cation exchange capacity, and soil pH value, it posed a great risk of groundwater contamination, so should be given serious attention. [ABSTRACT FROM AUTHOR]