Improving the carbon footprint of food and packaging waste management in a supermarket of the Italian retail sector.

In a consumer society, the retail sector contributes significantly to waste production. Supermarkets play a central role in the challenges of resources efficiency and waste prevention. The circular economy has become a major alternative to the classical economic model and the retail sector has begun moving along this path. The aim of this study is to analyse supermarket waste management systems to identify more sustainable and circular processes. A specific case study was analysed to assess and improve the waste management system of a supermarket. We used the DMAIC (Define - Measure - Analyse - Improve - Control) model from the Lean Six Sigma methodology to collect data and information. We evaluated the environmental performance of the waste management system through its carbon footprint and compared the environmental impacts in terms of CO-eq of different waste treatments for each waste category. We introduced a new waste management system in the supermarket, which demonstrated better performance. Our comparison of different waste treatments highlights the importance of recycling, particularly in the context of the circular economy. We then focused on organic matter, as the category producing the most waste and compared composting and anaerobic digestion. We found that anaerobic digestion releases less greenhouse gas emissions. Similar improvement programs can be directly adopted by other stores without repeating the analysis. Our study can inform future research into the use of organic waste for obtaining biogas and other sub-products. The integration of the Lean Six Sigma methodology and other environmental tools can also be assessed as a strategy in the circular economy.