Among the waste treatment methods, anaerobic digestion is an attractive option for the degradation of fermentable household wastes into useful products such as biogas and high quality compost. Therefore, we conducted a comparative experimental study between the anaerobic digestion of fermentable household waste and anaerobic co-digestion of fermentable household waste and septic tank sludge. The experiment was conducted in two tanks of 80 liters. The first tank was filled only with 14 kg of biodegradable household waste and the second was filled with 14 kg of household waste mixed with 4.2 L fresh septic tank sludge in a ratio Volatile Suspended Solids (VSS) of septic tank sludge on Volatile Organic Matter of waste (=MOV) (VSS / MOV = 0.3). The evolution of the COD yields a balance on the degradation of organic matter and biogas production.
Anaerobic digestion and anaerobic co-digestion took place at a temperature of 25C° in two stages so that the first step in a 80 L tank, stops at acidogenesis and that the second step (methanogenesis) takes place in another 10 L digester. The results yield that 1.3Nm3 methane are produced from the anaerobic digestion of waste and 1.8 Nm3 methane are produced from co-digestion of waste and faecal sludge.