Bioresource Technology, Vol.80, No.2, 153-156, 2001
Two-phase anaerobic digestion of spent tea leaves for biogas and manure generation
Anaerobic digestion of spent tea leaves from an instant tea manufacturing factory was studied in a two-phase digester. The hydrolysis and acidification phase resulted in the formation of high organic strength liquid called leachate, with a chemical oxygen demand (COD) of 12,880 mg/l, within the retention time of 10 days. The leachate was tested in a batch methanaogensis reactor for biogas production. An average biogas yield of 0.48 m(3)/kg of COD destroyed was obtained with an average COD reduction of 93%. The biogas was analyzed for 73% methane content.
Keywords:spent tea leaves;two-phase biomethanation;hydrolysis;acidification;leachate;methanation;biogas yield