Apparatus and Procedures for Assessing Inorganic Diffusion Coefficients for Geosynthetic Clay Liners

    Volume 23, Issue 2 (June 2000)

    ISSN: 0149-6115

    CODEN: GTJOAD

    Page Count: 9


    Rowe, RK
    Professor and Chair, University of Western Ontario, London, Ontario

    Lake, CB
    Graduate student, University of Western Ontario, London, Ontario

    Petrov, RJ
    University of Western Ontario, London, Ontario

    (Received 4 November 1998; accepted 2 December 1999)

    Abstract

    The apparatus and procedure for performing tests to obtain inorganic diffusion coefficients for Geosynthetic Clay Liners (GCLs) are described, and the processes (diffusion, anion exclusion and osmosis) that can affect the interpretation of these tests are discussed. Results from several inorganic diffusion tests on GCL and bentonite specimens show that the diffusion coefficients deduced for sodium (Na+) and chloride (Cl) are directly related to the final bentonite void ratio. It is shown that diffusion through GCLs (or thin bentonite layers) can be modeled using a bulk porous media diffusion coefficient (Dp) consisting of the total porosity, nt, and a deduced diffusion coefficient, Dt, (Dp = ntDt) without the need to establish the true effective diffusion coefficient () without the need to establish the true effective diffusion coefficient (De) and effective porosity (ne). However, for a longer bentonite plug sample it is shown that the true effective diffusion coefficient (De) and effective porosity (ne) must be established to predict the contaminant transport through the sample.


    Paper ID: GTJ11045J

    DOI: 10.1520/GTJ11045J

    ASTM International is a member of CrossRef.

    Author
    Title Apparatus and Procedures for Assessing Inorganic Diffusion Coefficients for Geosynthetic Clay Liners
    Symposium , 0000-00-00
    Committee D18