Anaerobic Co-digestion of Cooked Food Waste, Paper Waste and Potato Peel Waste

Abstract

Conventional anaerobic digestion technology of mono substrate has certain limitations such as it has low waste to energy conversion efficiency, low degradation rate, low buffering capacity which leads to large volume of digester and high cost of biogas production So, in order to improve conversion efficiency and to accelerate biogas production, the researchers co-digested new combinations of various substrates like cooked food waste (CFW), crushed paper waste (CPW), dry & crushed potato peel waste (DCPPW) in different proportion using cow dung inoculum in the present study. This study was carried out under mesophilic temperature condition of 33°C in lab scale digesters. The results of study showed that maximum methane gas was produced at ratios of 2:2:4 CFW: CPW: DCPPW and at pH value of 7.1 while no biogas was produced at the ratios of 2:4:4, 4:2:2, 2:2:2 CFW: CPW: DCPPW due to deviation of pH value from ideal (6.8-7.2) that is required for survival and growth of methanogenic bacteria. By analyzing the data, it has been found that factor A (Cooked Food waste) had significant 59.3 % impact on methane gas yield which was followed by interaction factor ABC (CFW*CPW*DCPPW) 20.5%, interaction factor AB (CFW*CPW) 12.26%, interaction factor BC (CPW* DCPPW) 3.37% and factor AC (CFW*DCPPW) 2.99%. The factor B (Crushed paper waste) as well as C (Dry & Crushed potato peel waste) alone had negligible impact on methane gas yield. Using formulated regression model, optimum volume of predicted methane gas was found out which was 398.5 Nml.