Chemico-osmotic efficiency of geosynthetic clay liners: Testing apparatus and preliminary results

The membrane behaviour of conventional and enhanced Geosynthetic Clay Liners is regarded with interest for applications in barrier systems as the presence of chemical osmosis improves the GCL containmenty properties. With the purpose of assessing the existence and persistence of chemico-osmotic behavior in GCLs, an apparatus able to perform chemico-osmotic diffusion tests on GCLs and soils has been developed. The paper describes the main features of the systems and preliminary results obtained using conventional and polymer-amended GCLs and a 20 mM KCl solution. The measured osmotic efficiency and solute diffusion coefficients were close to results in the literature on similar GCL materials and similar testing conditions, proving the system reliability.