ABSTRACT
Solid waste landfills can pose major environmental threats to the quality of groundwater resources. Unlike inorganic compounds, volatile organic contamination (VOC) can diffuse through the geomembrane, then breakthrough the underlying barrier and contaminate the surrounding groundwater. Understanding the progress and minimizing the migration of VOCs in landfill liners aids both barrier design and analysis of existing landfills. Most research focused on the transport of the liquid phase. The leaked leachate was approximated as uniform flow over the whole surface area of soil liner. The seepage velocity was evaluated by an equivalent hydraulic gradient, which depends on the height of the leachate level accumulated on the geomembrane. The medium was considered to be fully saturated with dissolved VOC due to aqueous phase advection and diffusion. Landfills generally have three types of covers: daily, intermediate, and final. Many daily covers are approximately 30cm thick exposed layers of clay soil over refuse. In this chapter, a mathematical model is proposed for non-isothermal, multi-phase moisture and VOC transport (in solid, liquid and gas phases) for unsaturated soil, incorporating finite deformations.
