Business models for community composting: analyzing future scenarios through Life Cycle Assessment

Municipal biowaste constitutes a significant portion of municipal solid waste, which can cause environmental impacts if not properly managed. Scientific literature reports and assesses various treatment strategies using Life Cycle Assessment (LCA). Among these, community composting represents an interesting approach, but it is not yet as widespread or regulated as energy communities. Therefore, investigating its implementation and environmental performance is essential. In this context, this study aims to compare different community composting scenarios through LCA. Specifically, four scenarios are modeled for potential implementation in the Municipality of Messina, Italy. Scenario 1 represents the current biowaste management system using industrial composting. The other scenarios are defined according to three previously identified business models: citizen-driven (S2), institutional-driven (S3), and public-private partnership (S4). These include biowaste treatment via home-composting (S2), vermicomposting (S3), and pile composting (S4). The scenarios are evaluated based on managing 1 tonne of biowaste generated in the Municipality of Messina as the functional unit. Both primary and secondary data are used for the inventory analysis. The impact assessment employs the CML-IA baseline method. Results show that S3 (vermicomposting) exhibits the highest environmental impact across nearly all impact categories, primarily due to the treatment phase. S1 (centralized industrial composting) also shows a high environmental impact related to global warming and other categories, mainly linked to transportation. Results also highlight some directions for future research, such as evaluating different functional units and scenarios involving mixed biowaste treatment.