中文摘要：

采用室内砂柱模拟试验方法研究了红壤和黑土两种土壤胶体对草萘胺在砂质土柱中迁移的影响。结果表明，整个淋滤过程中红壤和黑土胶体的回收率比较高，分别达到66．76％和74．75％；胶体促进了草萘胺在砂质土柱中的迁移，与对照相比（无胶体），加入红壤和黑土胶体后草萘胺的回收率分别提高了9．82％和10．63％。但是吸附在胶体上迁移的草萘胺数量比较少，只占到迁移总量的1．15％（红壤）和1．68％（黑土），物理非平衡机制可能在迁移过程中起支配作用。

英文摘要：

Mobile colloids may play an important role in adsorbing and enhancing the transport of a variety of contaminants in soil and ground water. The mobility of soil colloids and their influences on napropamide transport in aquifers was evaluated in disturbed sandy columns. Leaching experiments were conducted under saturated flow conditions and miscible displacement experiments were carried out with napropamide alone and with mixtures of napropamide and soil colloids. Water dispersible colloids were fractionated from two main types of soils from China, Plinthic Alliti-Udic Ferrosols（P） and Molli-Gelic Cambosols（M ） with a concentration of 300 mg.L^-1. Soil colloid suspensions were spiked with 5 mg.L^-1 napropamide and after 24 h equilibration they were applied to sand columns at a rate of -2.0 cm.h^-1. Effluent sample were collected in a fraction collector and analyzed for colloid, soluble and sorbed napropamide over 8-9 pore volumns of leaching. Colloid-free solutions with napropamide concentration similar to those of the soil colloids were used as controls. The results show that soil colloids were highly mobile and their recovery in the effluent was 66.76%（P） and 77.45% （M）, indicating that colloids remained stable throughout the leaching experiment. Moreover, soil colloids enhanced napropamide transport significantly; the presence of colloid P and colloid M enhanced the transport of napropamide by 66.76% and 74.75%, respectively. However, the actual amount of napropamide transported bound to either colloid type was minimal（less than 1.70% of leaching amount was recovered ）, indicating that the transport processes were mainly dominated by physical exclusion.