Properties Of Mixed Soil (Silty Clay And Dredged Soil) Used As Impermeable Materials In Clay Liner Of Landfill

With the quantity of municipal solid waste increasing day-by-day, sanitary landfills for these waste are more and more in china. Clay has become one of the most important barrier materials in landfills, because of their low hydraulic conductivity, high adsorption capacity against chemicals and retardation of chemicals transport. Due to the high organic content of dredged soil, its ability to adsorb various contaminants such as heavy metals warrant investigation of its use in caly liner of landfill.The main points of this thesis are as the following :1 , By the batch tests .investigations on cation adsorption of the mixed soil (dredged soil and silty clay) have carried out. It is shown that the mixed soil (dredged soil and silty clay) has much larger adsorption capacity in the case of Cu2+ and Zn2+ than silty clay2, The geotechnical properties of the mixed soil (dredged soil and silty clay) are studied and compared with the original silty clay by series of laboratory tests involving compactibility, permeability and strength which are mainly cared in clay liners of landfill.3 , To determine diffusion parameters of cations through the mixed soil, vertical diffusion tests are carried out . It is shown that the mixed soil's strong adsorption capacity in the case of Cu2+ results in a barrier with the mixed soil having a much less diffusion coefficient than silty clay.4, After the batch tests ,geotechnical characteristics of cation contaminated mixed soil are studied. It is found that changes in the mechnical properties of the mixed soil are small than silty clay.