Effect of Organic Loading Rate on the Performance of Acidogenic Reactor and Methanogenic Reactor during Two Stage Anaerobic Codigestion of Cattle Manure with Green Grocery Waste.

Abstract

Energy is a very essential part of our daily life but due to increase in human population the demand in energy is increasing. The fossil fuel is the primary energy source but the problem with fossil fuel is their rising demand with energy issues and GHG gas emissions. To overcome these problems biogas production through anaerobic digestion is the best alternative option. In two stage anaerobic digestion process at high organic loading rates the methanogenic reactor become unstable due to high VF As accumulation while the acidogenic reactor still can form more VF As. This can be overcome through constant VF As loading rate in methanogenic reactor. The Aim of the current research was to study the effect of organic loading rate on the performance of acidogenic reactor and methanogenic reactor during two stage anaerobic co-digestion of cattle manure with green grocery waste. The experiment was performed in two stage reactors having working volume of 5 liters each at controlled temperature of 37°C with retention time 10 days. Each OLR was run for more than two retention times and study the effect of OLR on the biogas production. The biogas yield at 5.5, 6, 6.5 and 7 OLR g VS L-'dai' was 0.242,0.292,0.210 and 0.168 NLig VS. While the maximum VFAs production at 7 OLR that was 13.3 giL. After this the methanogenic reactor was fed at different VF As loading rates in suspended growth reactor with biogas yield 0.07, 1.13,2.04, 1.02 and 0.47 NLig VFAs and attached growth reactor with biogas yield 0.25, 1.23, 2.31, 1.19 and 0.50 NLig VFAs at 0.25, 0.5, 0.75, 1 and 1.25 g VFAs L-' dai' respectively. This study concludes that high biogas yield was at 6 OLR, high VF As production at 7 OLR and high biogas yield at 0.75 VFAs loading rate giL in attached growth reactor during VFAs loading rate.