Seminar - Farzad Meysami - Implicit and explicit coupling in transport of salt through liner system

Wednesday 21 May 2008, 1.10 - 1.55 pm
Civil Engineering Lecture Theatre 3

Abstract:

One of the major goals of geoenviromental engineering is to protect groundwater against the presence of man-made chemicals in the natural soil environment. Liners are crucial components of many barrier systems which are used to limit and control contaminant migration from landfill to the groundwater.

Many different types of waste have negative impacts upon the wider environment. Contaminants, which are released to the ground from a landfill, can find their way down into groundwater. Movement of water and dispersion within the aquifer spreads the contaminant over a wider area which makes the water supplies unsafe. In this study the focus will be on barrier systems for municipal soil waste (MSW) with particular emphasis on salt contaminants as an important constituent in waste. The explicit coupling expressed as the influence of hyperfiltration and chemical-osmosis conter-advection on solute transport while implicit coupling expresses the dependence of effective salt diffusion coefficient on the chemical-osmosis efficiency coefficient .

Since the influence of membrane coupling is ignored in the advection-diffusion equation, the objective of the investigation is to assess how the discrepancy between coupled and uncoupled solutions (analysed by Shakelford and Malusis 2004) works when a more realistic representation of the multi-layered liner is used. This implicit and explicit coupling is done using COMSOL multiphysics (Finite Element).