Effects of C/N ratio on anaerobic co-digestion of cabbage, cauliflower, and restaurant food waste

Every day, a large amount of food waste (FW) is generated that causes serious environmental problems such as the production of greenhouse gases and leachate. A possible treatment for this waste is anaerobic digestion (AD), but there are several problems associated with the accumulation of volatile fatty acids (VFA), foaming, or low buffer capacity. In order to resolve or mitigate this problem, FW was mixed with cabbage and cauliflower (CCF) leaves and stalks at different carbon/nitrogen ratios (C/N) to add value to this agricultural waste and benefit from the advantages of co-digestion. Under the study conditions, promising results were obtained during the co-digestion of FW and agricultural wastes at C/N = 45. These include a high biodegradability (98%), a methane yield of 475 mLSTP CH4/g VS, and an organic loading rate (OLR) of 0.06 kg of VS/m3 h for the CCF and FW mixture (CCF + FW). Anaerobic co-digestion of CCF + FW might be an interesting option for the simultaneous treatment of these types of organic waste, with the consequent social and environmental benefits.