Temporal variation of LFG emission from different types of landfill cover

Abstract : A research project "OSSIMED" funded by the French Environment and Energy Management Agency (ADEME) started in 2011. The main goal was to identify the amplitude and importance of the methane and carbon dioxide emissions variations observed on a landfill site and to give hints for a more robust assessment of the global greenhouse gas emission of a landfill site in operation. Nine monitoring areas were selected on 3 types of cover (daily, intermediate and final cover) of a pilot site and different time scales were considered in order to allow the LFG emission monitoring on an hour, day, week and seasonal basis. The whole methane flux assessment conducted with the LFG surface fluxes variations monitoring for each area allows to precise the diffusive and convective fraction of the methane fluxes for each type of cover. These results explain the difference between the high oxidation rates observed for the diffusive fluxes and the medium oxidation rate observed for the whole methane emissions.