Abstract: One of the necessary ways to control water pollution of Taihu Lake is to dredge its polluted sediments. Owing to our country’s current economic and technical limitations as well as the enormous quantity of contaminated dredged sediments, the underneath cohesive soil layers without any treatment are directly selected as impervious barrier of the Xuelang confined disposal facility (CDF). In order to prevent contaminants in dredged sediments from polluting surrounding environment and groundwater during dumping, a comprehensive experimental study for evaluating the ability of these soil layers to retard infiltration and transportation of main contaminants (total nitrogen, ammonia nitrogen, nitrite nitrogen, total phosphorus, chemical oxygen demand (COD)) in dredged sediments has been made using permeability test, static adsorption test, dynamic soil column test and so on. It is shown that the clay layers beneath the Xuelang CDF are capable to adsorb and retard the main contaminants greatly.

Key words: contaminant, dredged sediments, clay impervious barrier, infiltration, transportation, laboratory test