Effect of Biochar on the Anaerobic Digestion Performance and Microbial Structure Community of Cow and Swine Manure Inoculum

To improve the flexibility and efficiency of conventional biogas engineering, cow manure inoculum (CMI) and swine manure inoculum (SMI) were added to the anaerobic digestion of swine manure with different total solid (TS) concentrations. Biochar was added to the anaerobic digestion (AD) of swine manure with 3% TS concentration to determine its effect on AD of swine manure with different inocula. The methane production performance in the SMI reactors was better than that in the CMI reactors; biochar treatment reduced methane production rate by 5.27% and 23.08%, respectively. The NH4+-N concentration in the CMI reactors was higher than that in the SMI reactors; biochar treatment reduced the concentration of NH4+-N. CMI contained more cellulose hydrolytic acidification bacteria, while SMI contained more proteolytic bacteria. Biochar treatment promoted the growth of key bacteria, thereby improving the stability of the AD system and enhancing the degradation of organics during AD