草萘胺在五种土壤及其胶体上的吸附行为

土壤胶体是土壤中颗粒最细小的部分,由于具有巨大的比表面积和较高的吸附容量,是环境中污染物的重要吸附剂,直接影响到污染物的归趋和生物有效性.本文采用批次吸附试验的方法,研究了农药草萘胺在黄棕壤等5种土壤及土壤胶体上的吸附行为.结果表明,草萘胺在供试土壤及胶体上的吸附均能很好地符合Freundlich方程;与本体土壤相比,...

Adsorption of napropamide on five soils and soil colloids

Colloids,the fine particles in the soil act as "carrier" preventing adsorption of pesticide to immobile soil matrix.Owing to their high specific surface area,colloids have a high sorptive capacity and can be excellent sorbent of low solubility,strongly absorbing contaminants.Studies have indicated that colloids are capable of adsorbing and enhancing the transport of a variety of contaminants in soil and ground water.The purpose of this study was determined the extent of adsorption of napropamide on bulk soils and soil colloids.Equilibrium batch adsorption experiments were performed over concentration range of 1 to 12.5 mg/L napropamide on bulk soil samples and colloidal suspensions of 100 mg/L.Freundlich coefficient Kf ranged from 3.98 to 12.82 for bulk soil and from 946 to 2 679 for soil colloids.For the colloids the Kf values decreased in the order of black soil colloid > Huangnitu colloid > calcareous soil colloid > yellow brown soil colloid > red soil colloid.A significantly positive correlation existed between Kf and organic carbon content of soil colloids(p<0.01),indicating that organic matter content of colloids was the crucial factor in affecting adsorption.