Adsorption-Desorption Behavior of Chlorimuron-Ethyl in Two Typical Soils in Northeastern China

With batch equilibrium methods, adsorption and desorption behavior and the effects of soil/solution ratio and pH on the adsorption of chlorimuron-ethyl in Brown earth and Black soil were investigated, besides, the mobility of chlorimuron-ethyl in both of the soils were also predicted from the adsorption results. Results show that the adsorption efficiency of chlorimuron-ethyl in Brown earth and Black soil increased but the adsorption intensity decreased as the soil/solution ratio increased. The adsorption amount of chlorimuron-ethyl in both of the soils decreased with the increase of pH value, and the adsorption mechanism may be different at different pH. Moreover, the adsorption and desorption isotherms can be well described with Freundlich equations, and Black soil had a much higher chlorimuron-ethyl adsorption ability than Brown earth. Besides, the desorption hysteresis was observed in both of the soils. Chlorimuron-ethyl can be easily leached to groundwater in Brown earth but the leaching ability was weaker in Black soil, which posts a certain hazard to people and the environment.