Optimization of bio-methane production process for combined treatment of sewage & municipal solid waste

Abstract: Handling solid waste such as municipal solid waste (MSW) has become a booming problem in highly populated urban areas. Even though it has a high potential of biogas generation in anaerobic digestion, it is not that successful as a single substrate. The early researches proved that it can be treated combined with sewage sludge as a co-digestion process. This study was done to find the best performing mixing ratio of MSW and sewage sludge (SS) which gives maximum bio methane output. In this study three mixing ratios for MSW to SS were used as 50:50, 60:40, and 80:20. The retention time was selected as 20 days and the process was continued for 11 days. The highest cumulative methane production was observed at 80:20 (MSW: SS) mixing ratio as 2957.8 ml of methane. The methane and carbon dioxide content in gas was measured by using gas chromatograph. Highest Total Volatile Solids reduction also recorded at 80: 20 (MSW: SS) ratio as 57.32% after 11 days. The best soluble COD reduction, 95.19% and COD reduction, 36.85% also recorded at 80:20 mixing ratio.