A Series Of Experimental Studies On Sodium Soda Residue As Impermeable Barrier Materials In The Lining System Of MSW Landfills

Based on several main design indexes of a liner system such as hydraulic conductivities , adsorption and attenuation efficiency against chemicals and retardation of chemicals transport and so on, this thesis systematically investigated soda residue and its compound soils with weathering clay and subclay for its use in clay liner of landfill. The main points of this thesis are as the following:1,A serie of tests are firstly performed for soda residue and two practical impermeable clay speciments(weathering clay and subclay)from two different MSW landfills of Qingdao to wholely evaluate three soils'several main indexes of design including compaction, permeability,shear strength and shrinkage.Test results show:soda residue has poorer compaction,higher shear strength and lower shrinkage than two clay speciments,and moreover its permeability values can be achieved the order of 10-7cm/s when compacted under optimum or near to optimum water contents.2,On the base of above experiments,the soda residue is respectively combinated with two clay speciments,forming two types of mixture compoud soils(soda residue+weathering clay and soda residue+subclay)and two intercalation compound soils(soda residue/weathering clay and soda residue/subclay),and then their permeating coefficients are tested.It can be concluded that both intercalation compound soils and the soda residue+subclay mixture compoud soils with 30%～40%subclay content are obtained the permeability values ranged in the order of 10-8cm/s.3,In this phase,the soda residue liner, the weathering clay liner, the subclay liner, the 60%soda residue+40%subclay mixture compound liner,the soda residue/weathering clay intercalation compound liner and the soda residue/subclay intercalation compound liner were selected for simulative column experiments by tap water and leachate in the imitated compactive permeameter. In order to investigate the capabilities and stabilities of watertight capabilities and the attenuation efficiencies against pollutants of six liners,we...