Co-digestion of municipal organic wastes with night soil and cow dung for biogas production: A Review

Currently, biogas production is one of the most promising renewable energy sources and it represents a very promising way to overcome the problem of waste treatment. Biogas, which is principally composed of methane and carbon dioxide, can be obtained by anaerobic fermentation of biomass such as manure, night soil, sewage sludge and municipal solid wastes. Furthermore, the solid residuals of fermentation (the digested slurry) might be reused as fertilizer, to enhance the fertility of the soil. The huge amount of waste generates in the urban areas especially organic fraction of municipal solid waste or simply municipal bio-waste, which is used as feedstock for biogas production; represents an environmentally sustainable energy source since it improves solid waste management while simultaneously providing an alternative clean energy source. The primary advantages of biogas technology is the use of organic wastes with a low nutrient content to degrade by co-digesting with different substrates in the anaerobic bioreactors, and the process simultaneously leads to low cost production of biogas, which could be vital for meeting future energy needs. This review clearly indicates that co-digestion of municipal organic waste with night soil and cow dung is one of the most effective biological processes to treat a wide variety of solid organic wastes and the use of these wastes for biogas production. In addition, this review briefly discussed the factors affecting biogas production and analytical methods.