Chemical evolution of GCLs during oedopermeameter tests
Evolution chimique des GSB dans des essais en oedoperméamètres
Résumé
Geosynthetic clay liners (GCLs) are used in landfill liner applications. The contact between clay and aggressive fluids like leachate may alter the chemical saturation of the clay and thus result in an increase in the hydraulic conductivity of the GCL. This paper presents the results of a project aiming at evaluating the impact of a real methanogenic leachate with a high electrical conductivity on the hydraulic conductivity of three different GCLs. Oedopermeameter tests were performed during four to five months according to NF P 84-705. The three GCLs tested contained either natural sodium bentonite or sodium activated calcium bentonite. The cation composition of the effluent was continuously analysed during the test duration. Results tend to show that various bentonites react differently in contact with a given fluid and that the nature of the bentonite has to be adapted to the chemical environment by which it will be surrounded.