Circularity assessment of municipal waste management scenarios using a MFA-LCA based approach: A case study in Brazil

One of the critical elements of the so-called circular green transition is to move from waste minimization to materials circularity, i.e. to implement a systems engineering approach in which the residues of a process are not seen as waste but as a resource to another process of an integrated circular economy network. So, this study aims to apply a circularity assessment of municipal waste management scenarios combining Life Cycle Assessment (LCA) and Material Flow Analysis (MFA) approach. Four scenarios were considered: scenario 1: the existing conditions of the system, scenario 2: based or recovery of the organic fraction by composting, scenario 3: focused on the circularity of the organic fraction by anaerobic digestion, scenario 4: using recycling and incineration. The LCIA approach used was CML 2001. The circularity of each scenario was compared in terms of materials and energy recovery and effect of circularity solutions in the impact categories. A multicriteria analysis was used to aggregate the results of circularity in all impact categories and obtain a ranking of scenarios to determine the final result. From the results it could be noted that even if the three considered scenarios correspond to a significant improvement compared to the base scenarios in terms of materials recovery, scenario 4 was ranked in first place as it results in both materials and energy recovery rates higher than the others. Moreover scenario 4 also has less impacts related to the emissions involved during the biological processing of the organic fraction, mainly eutrophication and acidification potential. So, the LCA approach was shown to be an efficient way to support circular economy assessment by providing a more holistic circularity overview than considering only MFA.