Enhanced hydrolysis and acidification strategy for efficient co-digestion of pretreated corn stover with chicken manure: Digestion performance and microbial community structure

Abstract

The effect of enhanced hydrolysis and acidification (EHA) strategy on co-digestion performance of pretreated corn stover (CS) with chicken manure (CM) was investigated. The EHA process was applied to the CS pretreated with KOH and liquid fraction of digestate (LFD), prior to anaerobic digestion. The results showed that the efficiencies of hydrolysis and acidification for the pretreated CS group were significantly higher than the CS group. The maximum cumulative biomethane yield of 240.5 mL·gVS−1 and 242.0 mL·gVS−1 were obtained for the KOH CS group and LFD CS group during the EHA process at 1 day, showing 26.6% and 27.4% improvement over that of the control, respectively. T90 was shortened by 38.2%–44.1% and 17.7%–38.2%, correspondingly. The synergistic effects and hydrolysis kinetics were also enhanced by the EHA process. The communities of bacteria (Firmicutes, Proteobacteria, and Bacteroidetes) and archaea (Methanosaeta, Methanobacterium, and Methanosarcina) were enriched by the EHA process, and their interactions contributed to the improved digestion performance. Therefore, the EHA process was recommended for efficient biomethane conversion in co-digestion of CS and CM.