Study on Biogas Production of Joint Anaerobic Digestion with Excess Sludge and Kitchen Waste

Excess sludge from wastewater treatment plant and kitchen waste were mixed at different ratios to investigate the digestion process and efficiency in a joint anaerobic digestion system. The results showed that the efficiency of joint anaerobic digestion couldbe higher than that for pure excess sludge or pure kitchen waste, when the TS ratio of excess sludge to kitchen waste was 1:4.After the digestion of 66 days, the degradation rates of COD, TS and VS could reach 49.7%, 37.8% and 30.0% respectively, and the corresponding gas productions of TS and VS could reach 368mL/g and 677mL/g respectively.