title: Methane from CO₂: Influence of different CO₂ concentrations in the flush gas on the methane production in BMP tests.
abstract: The influence of carbon dioxide (CO2) in the headspace gas on the specific methane (CH4) production of blank samples with just inoculum during Biochemical Methane Potential (BMP) tests was studied. The headspace of the bottles had been flushed with 15 different ratios of CO2 and N2 prior to incubation, while they were treated otherwise identically. The results revealed that the CH4 yield increased linearly with higher ratio of CO2 in the flush gas reaching a 30% higher yield at pure CO2 relative to pure N2 headspace conditions. However, a slightly distinct lag is noticeable during the initial phase of the degradation process at high ratios of CO2, hypothesizing a reversible disturbance of the biocenosis. Further experiments and analyses need to be performed to elucidate the underlying mechanisms.
authors.affiliation: Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 8, D-85748 Garching, Germany. Electronic address: k.koch@tum.de.
authors.forename: Konrad
authors.initials: K
authors.lastname: Koch
authors.affiliation: Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 8, D-85748 Garching, Germany; Bavarian State Research Center for Agriculture, Central Department for Quality Assurance and Analytics, Lange Point 6, D-85354 Freising, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Huber
authors.affiliation: Cranfield Water Science Institute, School of Energy, Environment and Agrifood, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK.
authors.forename: Yadira
authors.initials: Y
authors.lastname: Bajón Fernández
authors.affiliation: Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 8, D-85748 Garching, Germany.
authors.forename: Jörg E
authors.initials: JE
authors.lastname: Drewes
mesh_terms: D056804:Biofuels; D019149:Bioreactors; D002245:Carbon Dioxide / Q000378:metabolism*; D005858:Germany; D008697:Methane / Q000096:biosynthesis*; D009584:Nitrogen / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D056804:Biofuels; D002245:Carbon Dioxide; D009584:Nitrogen; D008697:Methane
keywords: Anaerobic digestion; BMP test; Carbon dioxide utilization; Headspace flushing