The Research Of Release Characteristics And Collection Efficiency Of Landfill Gas

Landfilling is the predominant method for municipal solid waste (MSW) treatment inChina. To investigate the fugitive methane and non-methane organic compounds (NMOCs)emission and the effectiveness of the control measures from active municipal solid wastelandfills, field measurement campaigns were conducted at Chinese landfills. Moreover, themonitoring results play a guiding role for the control of landfill gas (LFG). LFG collection isconsidered an effective method to reduce the methane emission from MSW landfills. Theaccurate efficiency of the LFG collection system, which plays a significant role in planning,design, and operation of a landfill, is practically unknown for Chinese landfills. Methanecollection efficiencies of three Chinese landfills with different collection systems were studiedin this study.Soil cover cannot completely prevent the release of LFG, and methane oxidation is themost important factors affecting methane release. Methane release of operating surface wassignificant, while methane oxidation did not been detected. Both in the soil covered surfaceand operating surface detected the concentrations of methane greater than0.1%. There was nosignificant correlation between the LFG emissions with meteorological conditions.Sulfur-containing compounds were the main odor sources of landfill, there were more typesof odorous pollutants which olfactory threshold were greater than1detected in workingsurface than the soil cover surface.Collection efficiencies of landfills with vertical wells and/or horizontal pipes rangedfrom5.8-27.9%, while a system equipped with geomembrane could get an efficiency of up to65.3%. The reasons why performances of the landfills studied in this research were notsatisfying were attributed to the high-level leachate, the pressure of gas collection pump didnot regulate scientifically, and the nonstandard operation technology.Using LandGEM model to estimate A landfill site, the generated methane and NMOCSduring the operating period accounted for88%and91%of the generated in the life ofcollection respectively. The gas production of per ton of MSW was30.2Kg/Mg. While, theemissions reductions of per ton of MSW were8.5Kg/Mg,10.2Kg/Mg,20.2Kg/Mg and24.6Kg/Mg for the four collection techniques (vertical wells, combined horizontal trenches andvertical wells, combined horizontal trenches and under-membrane pipes, novel combined collection system), and they accounted the amount of waste generated28%,34%,67%,81%respectively.