Bio energy conversion of organic fraction of Varanasi's municipal solid waste

Abstract

The present study was aimed at finding out the anaerobic digestion potential of organic fraction of municipal solid waste of Varanasi, India. Anaerobic digestion was preferred as the organic fraction has a high moisture content of about 85% on an average basis and a high C/N ratio in the range of 25-30. Sodium hydroxide was added to the substrate in the hydrolysis phase and cow dung slurry was used as inoculums in the methanogenesis step. The pH, COD and VFA were the vital parameters monitored in the hydrolysis stage, while biogas production rate was the parameter observed during methanogenesis step. The pH value decreased due to the formation of VFA during hydrolysis. Due to alkaline hydrolysis pre-treatment of waste, methane production was rapid in the methanogenesis step. The total biogas yield was found to be in the range of 0.35-0.40 N m3/kg volatile solids with a methane content of 60-65 %. © 2011 Published by Elsevier Ltd.