Anaerobic co-digestion of corn stover and wastewater from hydrothermal carbonation

This study aimed to investigate the interactions between wastewater of hydrothermal carbonation (W-HTC) and corn stover (CS) during anaerobic co-digestion. The results showed the maximum cumulative methane production of co-digestion was 280.7 ± 3.2 mL/g VS, and it increased by 5.84% and 10.69% compared with mono-digestion of CS and W-HTC, respectively. Increasing the HTC temperature and excess addition of W-HTC inhibits early and middle stage of co-digestion due to toxic organic inhibitors, and the negative effect of phenols is substantially more than furans. The microbial analysis illustrated the addition of W-HTC can promote the growth of Clostridia and Bacteroidia. The growth of Methanomassiliicoccus and Methanosarcina was more vigorous in most of co-digestions, which was positively correlated with methane production. The study concluded methanogenesis can be enhanced by the co-digestion of W-HTC and CS, which provide optimization of process conditions and some reaction mechanism for application of W-HTC in anaerobic digestion.