Enhanced methane production during the anaerobic digestion of chicken manure through the addition of pristine and recovered biochar
Tien Ngo, Kashish Ranlaul, Andrew S. Ball
Abstract
This study investigates the impact of a 50:50 mixture of pristine and recovered biochar (CBC) on high-solids anaerobic digestion of chicken manure, comparing its performance with pristine biochar (PBC), recovered biochar (RBC), and a Control group. The experiment, conducted under mesophilic conditions using a 15% total solid content and 5% biochar dosage, showed that CBC treatment achieves the highest cumulative biogas production (314 mL g-1-VS) and the highest cumulative methane production o(112 mL g-1-VS) over 21 days. Further, digesters containing CBC exhibited the highest rate of COD removal (80.8%), surpassing digesters amended with PBC (71.1%), RBC (69.2%) and Control (57.8%). Although digesters amended with PBC showed a higher TAN adsorption capacity of 48 mg g-1 compared to the 32 mg g-1 of CBC, both TAN adsorption and the existing microbial population of 1.2 ×1014 microbes per gram, have allowed CBC to exhibit superior digester performance. These findings offer valuable insights for optimising anaerobic digestion processes and cutting operational costs in waste-to-energy projects incorporating biochar as an additive.