Abstract
The effects of hydrogen (H2) injection amount, mixing, and sodium formate on in-situ biogas upgrading performance and microbial community structure were investigated during thermophilic digestion of pig manure in a continuous stirred tank reactor with a working volume of 11.2 L and an organic loading rate of 2.0 g volatile solid (VS)/(L∙d). Continuous mixing was favorable for in-situ biogas upgrading. The relative methane content and methane yield were maintained at approximately 80% and 269 L/kg VS, respectively, under continuous mixing conditions with an H2 injection rate of 0.66 ml/(min∙VReactor) and an H2:CO2 ratio of 4:1. The added H2 inhibited acetate production, but not propionate production, during acidogenesis. Sodium formate was more beneficial for the acetogenesis of propionate degradation and restored system stability. Strictly hydrogenotrophic methanogens (Methanoculleus, Methanobrevibacter, and Methanobacterium) were dominant in the thermophilic in-situ biogas upgrading system. The syntrophic relationship between syntrophic acetate-oxidizing bacteria (Gelria) and hydrogenotrophic methanogens was weakened after the addition of H2.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
