Effect of Narrow Feeding Regimes on Anaerobic Digestion Performance and Microbial Community Structure of Rice Straw in Continuously Stirred Tank Reactors

Abstract

Demand-oriented conversion of biogas is conducive to meeting the needs of biogas supply and reduces extra costs related to gas storage facilities. In this study, the effect of feeding regimes (FRs) on anaerobic digestion performance and microbial community structure of rice straw were investigated using continuously stirred tank reactors. The result showed that compared to the FRs of every day and every 6 days, the FR of every 3 days achieved the best biomethane yield and substrate conversion rate, which improved by 17.3% and 12.4%, respectively. Additionally, the FR of every 3 days had a significant impact on microbial richness and diversity, and also improved the abundance of dominant archaea Methanosaeta. This indicated that the FR of every 3 days was suitable for the growth rate of Methanosaeta, which resulted in better anaerobic digestion performance. A narrow FR is helpful to meet the demand-oriented conversion of biogas.