How does the choice of food waste collection strategy affect the environmental performance of the food waste system?

Abstract

Separating food waste supports a more circular economy. As the most visible part of the value chain, the collection system plays a key role in waste management performance. This study quantifies the environmental impacts of various food waste collection methods using life cycle assessment, focusing on climate change and potential trade-offs across other impact categories. Two different treatment alternatives were explored: composting and anaerobic digestion (AD). The functional unit was defined as the management of the average amount of food waste generated per person during a year in Norway. The results show that the collection strategy affects both sorting rate and environmental performance. Climate change impacts range from -9.7 to -7.5 kg CO₂ eq./person/year for AD and between -6.3 and 2.5 kg CO₂ eq./person/year for composting. Collection in paper bags in separate containers results in the lowest climate change impact for both treatment pathways, but may increase other environmental impacts. For the AD pathway, there are relatively small differences between the results for the studied collection options. The use of paper bags, however, is likely to be the only option that eliminates the risk of plastic pollution in the soil from bags. The study identifies a potential "separate container effect": a higher separation rate is achieved with separate containers compared to the optical bag sorting system. This emphasizes how crucial the choice of collection method is for effective food waste management.