Evaluation and Applicability of Flame Ionization Detector for Fugitive Emission

Landfills have been reported as one of the largest sources of atmospheric methane and have also been reported as a significant cause of global warming. According to the Intergovernmental Panel on Climate Change, globally fills contribute to 15% of total annual greenhouse gas emissions. Methane emission from landfills can be reduced considerably using gas collection system and cover system. The landfill covers need to work efficiently or prevent gas emission to the atmosphere to achieve an effective gas collection system. Based on the cover materials and presence of possible cracks in the cover, fugitive emissions may occur. To increase the efficiency of gas collection system, it is important to understand methane fluxes through the landfill cover systems and determine methane losses from landfills. Various methods, including static flux chamber, dynamic flux chamber, mass balance, or micrometeorological methods can be used for methane flux assessment on the landfill cover. These methods can be expensive and time consuming. However, in some cases measuring relative intensity of methane might be sufficient to avoid landfill contribution to greenhouse gas effect instead of knowing the methane fluxes. A portable flame ionization detector (FID) can be useful to determine the intensity of methane emissions and to identify possible locations of fugitive emissions. The study illustrates the application of the portable FID in a landfill for fugitive emission assessment. An extensive investigation was conducted using portable FID in a landfill cells, and a contour profile was developed for methane emissions. Based on the investigation, an average of 29.01 ppm methane emission was observed. However, few locations were detected as potential leaks for fugitive emissions and only one of the locations had emissions more than regulatory requirement of 500 ppm. The methane concentration results from portable FID were also confirmed using gas chromatograph (GC) in the laboratory.