Co-Digestion of Food Waste and Dairy Manure for Biogas Production

Co-digestion of food waste and dairy manure for biogas production was studied. Two mixtures of food waste and dairy manure were tested. For each mixture, the performance of the anaerobic digester was evaluated at two different organic loading rates. The results showed that the startup of a mesophilic digester treating mixtures of dairy manure and food waste was successful at the organic loading rate (OLR) of 2 g VS L super(-1)d super(-1). Stable performance of the digesters was obtained during digestion of the feed mixture consisting of 32% food waste and 68% manure at OLR values of 2 and 4 g VS L super(-1) d super(-1). At the OLR of 4 g VS L super(-1) d super(-1), a noticeable scum layer formed in the digester, causing relatively large variations in daily biogas production.