Removal of pesticides from rinsate by adsorption using agricultural residuals as medium

The feasibility of using agricultural residual with highly organic matter c ontent - spent mushroom compost (SMC) as adsorption medium for removal of p esticides including carbaryl, carbofuran, and aldicarb with a concentration range of 0-30 mg/L from rinsate was investigated. Bottle-point method was used to determine adsorption isotherms for single-pesticide and multi-pesti cides. It was found that SMC might potentially be used for on-farm treatmen t of pesticide rinsate. The adsorption capacity of SMC was increased compar ed to most soils, possibly related to the increased organic matter content. The rapid equilibrium of pesticide solution and SMC was consistent with a physical type of adsorption mechanism. The adsorption of carbamate pesticid es on SMC was found to exhibit nonlinear "favorable" adsorption behavior th at could be characterized well by the Freundlich isotherm model. In additio n, the multi-pesticide adsorption tests displayed the characteristics of co mpetitive behavior. The competitive ability of these three pesticides in mu lti-components adsorption was in the order carbaryl > carbofuran > aldicarb , which was consistent with the adsorbability of pesticides.