Description:
Anerobic co-digestion of food waste (FW) and sewage sludge (SS), thermal hydrolyzed sludge (THS), or the filtrate of THS (THF) were conducted to study their methane potential. In comparison to the co-digestion of SS with FW, the methane yield increased 9.7%~69.7% in the co-digestion of THS and FW, and 11.1%~101.1% in the co-digestion of THF and FW. The synergistic effect was weakened along with the addition of THS, while enhanced with the addition of THF, which could be attributed to the change of humic substances. Filtration removed most of humic acids from THS but remained fulvic acids in THF. Moreover, THF produced 71.4% of methane yield of THS although only 25% of organic matter was migrated from THS to THF. This indicated that hardly-biodegradable substances remained in dewatering cake and were removed from anaerobic digestion systems. The co-digestion of THF and FW provided a new way to enhance methane production