Insights into nutrients recovery from food waste liquid Digestate: A critical review and systematic analysis

This review paper presents a critical analysis of global research on the liquid fraction of food waste (FW) digestate. The study found that research on FW liquid fraction management accounted for 43% of the literature, followed by treatment methods (26%) and physical–chemical characterization (22%). By 2023, China led in scientific production on FW liquid fraction, contributing 46%, followed by Poland with 10% and the USA with 8%. The review emphasizes current technologies for nutrient recovery from the liquid fraction, as well as practical implications and limitations, identifying gaps in the literature. The most used methods for nutrient recovery were biofertilizer production from microalgae and membrane technologies. However, there is a need for further research on nutrient value, circular economy integration, the impact of food additives, ecological problems associated with FW decomposition, pathogen breeding, harmonized legislation to support recovered fertilizer commercialization and innovative nutrient recovery technologies. This approach provides valuable insights for stakeholders, enabling the creation of effective strategies that promote sustainable agricultural practices and circular economy initiatives through nutrient recovery from FW digestate.