Kinetics of tebuconazole photodegradation behavior in soil

Kinetics of tebuconazole photodegradation in soil and the associated influencing factors were investigated under high-pressure mercury lamp. The results show that tebuconazole photodegradation in soil matches with the first order chemical reaction series. The order of tebuconazole photodegradation rate in different soils is as follows: lime concretion black soil > river cultivated fluviogenic soil > krasnozem > brown earth > purple soil. The order is closely related with organic matter and clay content of the soil. Tebuconazole photodegradation accelerates with increasing soil moisture, because that water enhances pesticide molecule mobility in soils. Tebuconazole is more rapidly photodegraded in neutral than in acid and alkaline soil conditions. Negative correlations exist between photodegradation rate and tebuconazole concentration of 20~100 mg·kg^-1. Surfactants, DDBS and HDTMA have photoquenching effect on tebuconazole photodegradation. Urea photoquenches tebuconazole photodegradation, while KCl exhibits photosensitizing effect. Degradation half-life of tebuconazole in soil is 10~22 minutes.