Investigation on adsorption and degradation of fenhexamid in soil

In order to evaluate the ecological risk of fenhexamid in soil, the adsorption and degradation of fenhexamid in red soil and paddy soil were investigated. The leaching properties and the potential of ground water contamination were evaluated. The residues of fenhexamid were measured by ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The adsorption of fenhexamid in red soil and paddy soil followed the freundlich adsorption isotherm equation. The K_OC values were 373.69 and 726.86 mL/g, respectively, which revealed higher adsorption capacity of paddy soil than that of the red soil. The degradation half-lives of fenhexamid under the aerobic conditions in the red soil and the paddy soil were 0.63 and 5.06 d, respectively, whereas they were 6.80 and 9.24 d, respectively, under the anaerobic conditions. It was demonstrated that the degradation of fenhexamid was faster under the aerobic condition than that under the anaerobic conditions. Fenhexamid was of low ground water contamination potential and its ground water ubiquity score values were 1.19 and 1.10 in the red soil and the paddy soil, respectively. The results have provided more data for the evaluation of the ecological risk of fenhexamid.