A LABORATORY-BASED STUDY OF BIOMETHANATION BY THE CO-DIGESTION OF MUNICIPAL SOLID WASTE WITH DOMESTIC FOOD WASTE AND WASTEWATER SLUDGE

The increasing global demand for sustainable alternative sources of energy has driven the need for studies in renewable energy. Biogas may serve to satisfy energy demands as a viable substitute to fossil fuel, thereby reducing indiscriminate deforestation. The large volume of waste generated in the form of food and other solids in urban areas could serve as suitable organic substrates in the production of biogas thus, providing a cheap and eco-friendly method of managing wastes. In this study, municipal solid waste was co-digested with Food Waste (FW) and Municipal Solid Waste (MSW) at different ratios to optimize the production of biogas. The anaerobic digestion process was conducted at ambient (room) temperature for three weeks for a hydraulic retention time. The performances of the wastes were assessed based on the volume and quality of the biogas produced. The highest amount of biogas produced (765 cm3) was from the co-digestion of food waste and MSW in the ratio of 1.5:1.5. Methanogenic archaea isolated from the biogas digestate belonged to the following genera: Methanobacterium, Methanococcus, Methanosarcina, and Methanoplanus. In this study, the biogas produced from the co-digestion of food waste and municipal solid waste was better in terms of quality and quantity compared to that produced from the co-digestion of MSW with sludge. Thus, the findings of this study suggest that food waste has great potential as a substrate during the anaerobic digestion of municipal solid waste. Keywords: sludge, food waste, municipal solid waste, methanogens, biogas