Anaerobic co-digestion of commercial food waste and dairy manure: Characterizing biochemical parameters and synergistic effects

Abstract

Anaerobic digestion of commercial food waste is a promising alternative to landfilling commercial food waste. This study characterized 11 types of commercial food wastes and 12 co-digestion blends. Bio-methane potential, biodegradable fraction, and apparent first-order hydrolysis rate coefficients were reported based upon biochemical methane potential (BMP) assays. Food waste bio-methane potentials ranged from 165 to 496 mL CH4/g VS. Substrates high in lipids or readily degradable carbohydrates showed the highest methane production. Average bio-methane potential observed for co-digested substrates was −5% to +20% that of the bio-methane potential of the individual substrates weighted by VS content. Apparent hydrolysis rate coefficients ranged from 0.19 d−1 to 0.65 d−1. Co-digested substrates showed an accelerated apparent hydrolysis rate relative to the weighted average of individual substrate rates. These results provide a database of key bio-digestion parameters to advance modeling and utilization of commercial food waste in anaerobic digestion.