High Solid Anaerobic Co-digestion Pilot Scale Experiment of Kitchen Waste and Cow-dung

Under mesophilic condition (37°C), a bench-scale experiment based on high solid anaerobic digestion process was conducted in a fed-batch single phase reactor. The result shows: (1) According to gas production and ph value change, there are mainly four stages concerned: start-up stage, recovery stage, stabilization stage and super saturation stage.(2)After the start-up stage, the ph value reached minimum of about 5.6; during the recovery stage, pH value in the reactor stabilized between 6.8~7.8 with the increase of TS concentration, the gas production and methane concentration also increased. (3) The anaerobic digestion of the bio-waste as a whole worked fine during the stabilization stage, the maximum daily gas production happened on the 125th day, the maximum was 3.78L.d^-1 and TS concentration in the digestive juice was 14.78%, methane concentration was about 50%~55%, HRT was 20 days and the biodegradation rate was 65.28%.(4)During the saturation stage, the TS concentration reached 17.71% and ammonia concentration was 3770mg.L^-1, inhibiting metabolism of methanobacteria, pH value of digestive juice steadily decreased to about 5.8 and biodegradation rate also fell to 48.25%.