Synergistic Effects of Anaerobic Co-Digestion of Chicken Manure and Corn Stover in Batch and Continuous Modes

Abstract

The present study aimed to evaluate the anaerobic co-digestion process of chicken manure and corn stover to identify the key parameters that influence methane production. Results from both batch and semi-continuous tests showed that co-digestion enhanced methane production, with an optimal chicken manure to corn stover ratio of 2:1 under experimental conditions. When this ratio was maintained, methane production increased by 36% in batch tests, resulting in a biochemical methane potential of 333 mL/g VS. In semi-continuous tests, co-digestion at a hydraulic retention time of 30 days resulted in a methane production increase of 39%, corresponding to a methane yield of 318 mL/g VS. The inclusion of chicken manure proved effective in improving buffer capacity by generating ammonium bicarbonate, which facilitated stable operation during the digestion process. The observed improvement in methane production could be ascribed to the C/N ratio and the increased biodegradability of chicken manure. These findings offer valuable insights into optimizing anaerobic co-digestion to achieve higher methane production levels.