Centrifuge modelling of contaminant migration through composite liners

The transport, fate and remediation of contaminants in unsaturated porous media are not readily amenable to numerical simulation and bench testing is limited. The centrifugal technique is advantageous for modelling contaminant migration in fine-grained soils since the method is relatively quick and is performed under bulk densities and confining stresses encountered in natural soil deposits. In this paper, the results of centrifuge experiments of progression of a contaminant pulse through composite liners are reported. Centrifuge experiments have been performed with compacted clay liner having a model thickness of 10 mm and polyethylene (representing geomembrane) having a thickness of 0.05 min at different acceleration levels. In all the experiments, the polyethylene was placed above the clay liner. The results are presented in the form of solute breakthrough curves. It is concluded that the centrifuge test results yield more realistic data on contaminant migration through composite liners