Enhancement of Anaerobic digestion of cow manure through inoculation under mesophilic conditions

Abstract Now a days, anaerobic digestion (AD) systems are using a wide range of techniques to improve their performance, including co-digestion, inoculation, and addition of various accelerants. The AD of cow-manure (CM) was inoculated with ruminant intestinal waste (IW) in this study. It was hypothesized that methanogens present in intestinal waste will enhance anaerobic digestion, which will result in increased methane production. Five different CM/IW ratios (1:0, 9:1, 7:3, 1:1, 0:1) of wet weight were introduced in AD systems at mesophilic environmental (37 ◦C) to find the best combination of CM and IW. All of the mixture CM/IW ratios (9:1, 7:3, and 1:1) demonstrated a good synergistic effect and yielded a higher cumulative biogas yields than CM and RIW alone. The CM/IW (9:1) had the maximum cumulative biogas yield (239 mL/g VS), COD removal rate (40%), VS removal rate (27%), and total solid (TS) removal rate (24%). In the current study fertility status (nitrogen, N; phosphorus, P and potassium, K) of digestate was determine while most of the previous studies are only on biogas production. Digestate with ratio of 9 to 1 was found to be the best with cumulative NPK 4.53%. The inoculation technique using IW can be an effective means of increasing the bio-degradation waste's efficiency and generating more energy.