Effects of Feeding Regimes on Process Performance and Microbial Community Structure in Anaerobic Semi-continuously Stirred Tank Reactors Treating Corn Stover
2022
Li, Yuqian | Ma, Junwei | Yuan, Hairong | Li, Xiujin
Corn stover is one of the dominant agricultural wastes in China, with high lignocellulose contents. Anaerobic digestion of corn stover converts biomass to biogas as sustainable energy. To improve the performance of anaerobic digestion, as well as for flexible biogas production, the effects of different feeding regimes on biogas production, system stability, and microbial community structure were investigated using laboratory-scale semi-continuously stirred tank reactors (semi-CSTRs) fed pretreated corn stover once a day (R1), every 2 days (R2) and every 3 days (R3) at an equivalent amount. The results showed that R3 and R2 produced 11.1% and 8.4% more methane, respectively. R3 correspondingly had higher lignocellulose conversion rates and system stability, followed by R2 and R1. Greater fluctuations in biogas, VFA concentrations and pH were found in less frequently fed reactors during the time interval between two feeds. Additionally, less feeding increased the relative abundance of Bacteroidetes and Firmicutes during hydrolysis and acidogenesis, and the dominant genus of archaea in all reactors was Methanobacterium, which is a hydrogenotrophic methanogen. Therefore, appropriately reducing the feeding frequency can increase the process performance of anaerobic digestion of corn stover.
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