In this study, the experiment was carried out to produce methane by applying Semi-Continuous Leachate Recirculation Anaerobic Digestion System fed with source separated food waste from school cafeteria. There were two systems and each system consisted of a bioreactor and a leachate tank. Each bioreactor had a screen near the bottom of the reactor. 2L of Separated leachate was collected to the leachate tank each day by using a tubing pump and the leachate from the leachate tank was pumped to the bioreactor at the upper of the bioreactor. Through this circulation, the leachate having high concentration of VFAs was supplied to the bioreactor. At the beginning of the experiment, food waste/inoculum anaerobic sludge volume ratio was 2:8 that is 9g VS/L of OLR(Organic Loading Rate). Feeding was conducted every two weeks. Initial conditions of bioreactor was 30g VS/2･week and 33g VS/2･week were fed to bioreactor A and bioreactor B, respectively. Average biogas yields of the bioreactor were 0.723m³ Biogas/kg VS added in reactor A and 0.648m³ Biogas/kg VS added in reactor B.

• Byong-hi Lee(Dept. of Environmental Energy Eng., Kyonggi University)
• Chan-hui Cho(Dept. of Environmental Energy Eng., Kyonggi University)