Waste Containment System to Limit Landfill Gas Emission—Mechanism, Measurement, and Performance Assessment

Abstract

The biodegradation of municipal solid wastes (MSW) within waste containment system (engineered landfill) generates various gases, primarily, methane and carbon dioxide, commonly known as landfill gases or biogas. Methane generation in landfills and the resulting emissions to the atmosphere have become most anthropogenic methane source. The generation of landfill gas could create a pressure gradient within the waste containment system that forces the gas to migrate. As reported by few case studies, the migration of landfill gas through landfill covers is unavoidable even with the provision of gas drainage layer in the landfill capping system. Hence, the performance of waste containment system, in specific, cap barriers under gas flow condition needs to be evaluated, monitored, and understood. This chapter essentially deals with the nature and movement of gases in various cap barriers due to transport mechanisms like advection and diffusion. The mechanism involved in the generation of landfill gas due to biodegradation of MSW, gas transport through cap barrier, and development of test apparatus for the determination of transport parameters have been explained. This chapter highlights the need for evaluation of gas permeability and the diffusion coefficient of the cap barriers experimentally. The factors governing the performance of various cap barriers under gas flow conditions have been explained.