ABSTRACT
To increase the production of methane, when cattle manure (CM) is digested, pretreatments can be applied and/or the manure can be co-digested with other wastes. In this research work, a mixture of CM, food waste (FW) and raw glycerine (Gly) in a proportion in weight of 87% CM, 10% FW and 3% Gly was digested, (a) without pretreatment and (b) with pretreatment by ultrasound, applying a sonication energy of 1040â kJ/kg total solids. Specific methane production was 290â Lâ CH4/kg volatile solids (VS) without pretreatment and 520â Lâ CH4/kg VS with pretreatment. With respect to the volumetric methane production, 1.07â Lâ CH4/Lreactor.day was produced in the first case, and in the second case, 1.98â Lâ CH4/Lreactor.day. We can conclude that the application of ultrasound pretreatment significantly improved the production of biogas.