A simulation model for methane emissions from landfills with interaction of vegetation and cover soil

摘要

Highlights•Combined effect of vegetation and cover soil on CH4oxidation, transport and emission was modeled.•O2emission and CH4transport via plant directly was modeled.•A significant difference of gas profile distribution and CH4emission rate was obtained in vegetated and bare areas.AbstractGlobal climate change and ecological problems brought about by greenhouse gas effect have become a severe threat to humanity in the 21st century. Vegetation plays an important role in methane (CH4) transport, oxidation and emissions from municipal solid waste (MSW) landfills as it modifies the physical and chemical properties of the cover soil, and transports CH4to the atmosphere directly via their conduits, which are mainly aerenchymatous structures. In this study, a novel 2-D simulation CH4emission model was established, based on an interactive mechanism of cover soil and vegetation, to model CH4transport, oxidation and emissions in landfill cover soil. Results of the simulation model showed that the distribution of CH4concentration and emission fluxes displayed a significant difference between vegetated and non-vegetated areas. CH4emission flux was 1–2 orders of magnitude higher than bare areas in simulation conditions. Vegetation play a negative role in CH4emissions from landfill cover soil due to the strong CH4transport capacity even though vegetation also promotes CH4oxidation via changing properties of cover soil and emitting O2via root system. The model will be proposed to allow decision makers to reconsider the actual CH4emission from vegetated and non-vegetated covered landfills.