Comparison of Greenhouse Gas Emissions in Solid Waste Management Systems Using Life Cycle Assessment (LCA)

Municipal solid waste treatment is one of the greenhouse gas (GHG) emissions sources. Waste management systems can affect GHG emissions from these sources. This study evaluates the current and other three patterns of integrated waste management systems (IWMSs) with respect to greenhouse gas emissions, using life cycle assessment (LCA), based on the Lavandevil case.
System 1 represents the current MSW management in Lavandevil, including collection, transport and landfilling. Other three IWMSs along with collection, transport, landfilling and incineration include recycling (system 2), anaerobic digestion (system 3) and recycling and anaerobic digestion (system 4).
The results show that global warming potential (GWP) from system 1 amounts to 840 Kg CO2 eq, whereas GWP from system 4 reduces to 474 Kg CO2 eq for each ton of Lavandevil’s MSW. Considering the results obtained from this study, in all management systems (system S1-S4), lanfilling has the highest share in GWP increasing. GWP from landfilling can be reduced by power generation from landfill gas (LFG). Therefore, in this study, all management systems (system S1-S4) are assumed under two different methods (landfilling with and without energy recovery). By assumption, 75% recovery of landfill gas results in a GWP reduction of nearly 36% by GWP of landfilling.
The results show that source separation and use of separate waste in recycling and anaerobic decomposition processes have the highest impact in GWP reducing. Therefore, this study suhhests that source separation of waste, recycling and anaerobic decomposition treatment should be increased in the country’s waste management systems. On condition that both treatment systems could not be founded together, recycling is favorable over anaerobic digestion.