Environmental impacts of food waste management technologies: A critical review of life cycle assessment (LCA) studies

Food waste is a serious global problem. Therefore, it is essential to reduce food waste and adopt recycling strategies to minimize its environmental impacts. However, conventional waste disposal methods emit harmful gases such as dioxin, CH4, N2O, and NH3, which contaminate the air and water resources. This work reviews the environmental consequences of food waste based on lifecycle assessment (LCA) techniques using methods such as anaerobic digestion, composting, and landfilling. It also pays attention to novel techniques like gasification and hydrothermal carbonization. This review critically evaluates and compares the environmental impacts assessed by LCA such as global warming potential (GWP), climate change (CC), marine eutrophication (MEP), human toxicity (HT), terrestrial eco-toxicity (Tecox), terrestrial acidification (TAP), freshwater ecotoxicity (FEW), freshwater eutrophication (FEP), marine ecotoxicity (ME), fossil depletion (FD), ozone layer depletion potential (OLDP), and land occupation (LO) for each method. This study also highlights the importance of technological innovation and the need to improve current food waste valorization practices by focusing on the LCAs of the approaches listed above. With respect to its novelty, this work consolidates a useful comparison among the food waste utilization technologies with respect to environmental impacts based on LCA studies. Furthermore, this work emphasizes the need for in-depth research on the LCA of sustainable techniques such as gasification, fermentation and hydrothermal carbonization to support evidence-based decision-making.