Opportunities for holistic waste stream valorization from food waste treatment facilities: a review

Abstract

Abstract Difficult-to-biodegrade fractions (DBFs) generated from the biological treatment of food waste (FW) account for approximately 30% of the actual waste. These wastes are difficult to degrade or are considered indigestible residues of the aerobic and anaerobic fermentation treatment of FW treatment facilities. The currently applied disposal routes for DBFs exert environmental pressure and underutilize waste as resources. Therefore, these challenges must be overcome. An innovative strategy for the enhancement of the energy value and beneficial products from FW and the associated DBFs is proposed in this review. We propose conceptual future optimization routes for FW and DBFs via three types of technology integration. Pyrolysis techniques thoroughly treat DBFs to produce various value-added bio-energy products, such as pyrogenic bio-char, syngas, and bio-oil. Anaerobic digestion treats FW while utilizing pyrolysis products for robust performance enhancement and bio-methane upgrade. This holistic route offers conceptual information and proper direction as crucial knowledge for real application to harness the inherent resources of waste streams generated from FW treatment facilities.