Experimental investigation on anaerobic co-digestion of food waste and water hyacinth in batch type reactor under mesophilic condition

Abstract

India generated around 1.45 lakh tonne of municipal solid waste (MSW) per day, out of which 40% is organic biodegradable waste, which has food waste as the major component. Scientific conversion of this food waste to energy is always challenging. In the present study, anaerobic digestibility of food waste as a mono digestion substrate and co-digestion of food waste with water hyacinth were tested and analyzed in a batch type anaerobic digester of capacity 60 l. Four different samples, i.e., only food waste, only water hyacinth, and with food waste to water hyacinth in the ratio of 15:2 and 8:3 to maintain total solids contain equal in all samples were analyzed for the anaerobic digestion (AD). Biogas yield for the above four samples were found to be 370.85 (ml/g VS), 320.54 (ml/g VS), 286.50 (ml/g VS), and 298.83 (ml/g VS), respectively. The average methane content was found to be 68.3%, 58.2%, 52.1%, and 65.4%, respectively whereas CO2 content was found to be 30.2%, 40.9%, 46.6%, and 33.3%, respectively, using gas chromatography. The temperature variation for anaerobic digester was measured in the range of 32 to 43 °C during the experiment without supplying any external heat. pH value of all samples was ranged between 6.5 and 7.5 at the end of the experiment. The results of this study conclude that co-digestion of food waste with water hyacinth has higher operational stability compared to mono digestion of food waste.