Application of landgem mathematical model for the estimation of gas emissions from contaminated sites. A case study of a dumping site in Lahore, Pakistan

Decomposition of organic waste in dumping sites and landfills prompts the uncontrolled emission of greenhouse gases which enhances global warming and related issues. The present investigation estimated the total landfill gas, methane, carbon dioxide and non-methane organic compounds emissions from Mahmood Booti dumping site located at Lahore, Pakistan from 1996 to 2045. LandGEM 3.02 model was utilized to evaluate the gas emission with the volumetric methane 50%, production potential (170 m³/Mg), and methane generation rate (0.050/year). The findings demonstrated that organic and food wastes had the maximum quantity in the solid waste stream (63.46%). Methane measured from solid waste was 1.150E+03 (Mg/year) in 1997 in the first year after waste was accepted by landfill while the maximum methane generation rate happened from 2014 to 2018, i.e., from 4.049×10⁴ to 4.654×10⁴ Mg/year, respectively. The study finding highlighted that all gases emissions have an increasing/rising trend up to 2021 and then gradually their level will decrease because most of the organic fractions of solid waste would degrade with time. The findings of this study can be used to identify the impacts and contribution of MBODS in the global emission of greenhouse gases. The study concludes that proper management of landfill gas will not only decreases greenhouse gas emissions, diminishing adverse impacts on public health but can also be used as a sustainable energy source.