Experimental investigation of biogas production from kitchen waste mixed with chicken manure

Biogas produced from solid kitchen waste (KW) mixed with chicken manure (M) at different mass ratios was investigated. The effect of the ratio of the amount of water to the mixed solid waste on the amount of biogas produced was studied. The results showed that at a fixed ratio of water-to-solid waste, the amount of biogas increased as the amount of chicken M increased. At a fixed M-to-KW ratio, the amount of biogas produced increased as the solid content increased and then decreased, reaching its maximum value at a solid waste-to-water ratio of 1:1. The pH of the bioreactor containing the KW-M mixture dropped with time, resulting in a decrease in the amount of biogas produced. Controlling the pH value by titrating with NaOH solution improved the production of biogas. Investigating biogas produced from sludge showed that the pH of the reactor slightly decreased and then increased slightly. The results also showed that the amount of biogas produced from sludge containing 3% solid waste was larger than the amount produced from sludge containing 6% solid waste.