Keywords: municipal solid waste, MSW, waste characterisation, landfilling, landfill gas, methane, air pollution, India, greenhouse gases, GHG emissions, first–order decay modelling
Assessment of landfill gas and methane emission at Keru landfill site, Jodhpur (India)
Jodhpur is densely populated and urbanised city of Rajasthan state. The population of the city is considerably increased in past few decades due to rapid urbanisation and industrialisation within the city. Presently inhabitants of Jodhpur generate about 392 t/d of MSW. MSW management has remained one of the most neglected areas of the municipal systems. About 70–80% of generated MSW is collected and dumped at Keru landfill site. Only 100 t of the collected MSW is treated through composting plant, therefore, along with residue from composting process, the majority of MSW is dumped at Keru landfill site. In the absence of LFG collection system, this landfill is a major source of air pollution due to generation of GHGs. In present study, various physico–chemical parameters of the MSW deposited at Keru landfill site were analysed for characterisation. First–order decay (FOD) model was used to estimate the LFG and methane generation potential of Keru landfill and the results are compared with applying modified triangular model (MTM) and has been proposed. Using FOD model the methane generation potential yields an estimate of 1.55 Gg/y, which accounts to about 0.08–0.31% of existing Indian landfill methane emission estimated, and 0.008% of global landfill methane emission. LFG and methane emission from Keru landfill for the year 2006–2011 has been estimated in this study and discussed with Indian and global implications of national methane emission.