Temporal and spatial variation of greenhouse gas emissions from a limited-controlled landfill site

Landfilling biodegradable waste is an important source of global greenhouse gas (GHG) emissions. Among the several types of landfill, limited-controlled landfill is a common method used to dispose of domestic solid waste, especially in developing countries. However, information about GHG emissions from limited-controlled landfill sites has rarely been reported. In this study, the GHG emissions from a typical limited-controlled landfill site were investigated under a regular period for one year. The number and positions of static chambers were arranged according to the guidance on Monitoring Landfill Gas Surface Emissions by the UK Environment Agency to obtain representative data from the heterogeneous surface of the landfill. Inverse distance weighting (IDW) was applied to evaluate and visualise the GHG emissions from the whole landfill surface based on the measurements of distributed static chambers. As an important GHG source of the landfill site, the emissions from the landfill leachate treatment plant were also measured. The results revealed that CH₄ and N₂O emission fluxes from the landfill area were 1324.73 ± 2005.17 mg C m^-2 d^-1 and 2.16 ± 2.33 mg N m^-2 d^-1, respectively, and the fluxes from the leachate treatment plants were 23.92 ± 29.20 mg C m^-2 d^-1 and 16.40 ± 16.89 mg N m^-2 d^-1, respectively. CH₄ and N₂O releases preferred to present spatial heterogeneity, while temporal heterogeneity was expected to exist in CH₄ and CO₂ emissions. The annual GHG emissions from the limited-controlled landfill was calculated to be 1.078 Gg CO₂-eq yr^-1, which was the least among all types of landfill sites. In addition, the GHG emission factor was 0.042 t CO₂-eq t^-1 waste yr^-1 which could not be ignored compared to the sanitary landfills. Therefore, it is advisable to give more attention and determine a potential solution for reducing GHG emissions from limited-controlled landfill sites.