4. Conclusions
This study was aimed at assessing different municipal solid waste management scenarios using a comparative LCA approach in the capital of Iran. Based on the results obtained, the scenario Sc-3 (incineration combined with composting) and Sc-1 (landfilling combined with composting) led to the most adverse environmental impact on the Human Health and Ecosystem Quality damage categories. In the Climate Change damage category, the scenario Sc-1 resulted in the worst impact while the other scenarios showed improving impacts on this damage category. Also, the scenario Sc-1 had the least helpful effect on the Resources damage category. Overall, normalized values of different scenarios showed that the scenario Sc-1 was the worst scenario among the studied scenarios. These findings stresses that ‘landfilling combined with composting’ scenario; a conventional but fading MSW management practice in Iran, had adverse impacts on the environment; therefore, more eco-friendly scenarios should be implemented. To achieve that, the combination of AD with incineration (Sc-4), is suggested as the most environmentally-friendly procedure. Finally, although the ‘incineration combined with composting’ scenario (Sc-3) is being considered to be implemented in Iran in the future, but the findings of this study revealed that this scenario may not fulfill the environmental expectations for it seems to have adverse impacts on the environment.