title: Methane production in an UASB reactor operated under periodic mesophilic-thermophilic conditions.
abstract: Methane production was studied in a laboratory-scale 10 L anaerobic upflow sludge bed (UASB) reactor with periodic variations of the reactor temperature. On a daily basis the temperature was varied between 35 and 45 degrees C or 35 and 55 degrees C with a heating period of 6 h. Each temperature increase was accompanied by an increase in methane production and a decrease in the concentration of soluble organic matter in the effluent. In comparison to a reactor operated at 35 degrees C, a net increase in methane production of up to 22% was observed. Batch activity tests demonstrated a tolerance of mesophilic methanogenic populations to short-term, 2-6 h, temperature increases, although activity of acetoclastic methanogens decreased after 6 h exposure to a temperature of 55 degrees C. 16S sequencing of DGGE bands revealed proliferation of temperature-tolerant Methanospirillum hungatii sp. in the reactor.
authors.affiliation: Biotechnology Research Institute, NRC, 6100 Royalmount Ave, Montréal, QC, Canada H4P 2R2.
authors.forename: J-S
authors.initials: JS
authors.lastname: Bourque
authors.forename: S R
authors.initials: SR
authors.lastname: Guiot
authors.forename: B
authors.initials: B
authors.lastname: Tartakovsky
mesh_terms: D000693:Anaerobiosis / Q000502:physiology; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques; D002849:Chromatography, Gas; D004591:Electrophoresis, Polyacrylamide Gel; D006361:Heating / Q000009:adverse effects; D008697:Methane / Q000378:metabolism*; D019639:Methanospirillum / Q000201:enzymology* / Q000254:growth & development; D009691:Nucleic Acid Denaturation; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D012722:Sewage / Q000032:analysis / Q000382:microbiology; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods
chemical_list: D012722:Sewage; D008697:Methane; D010100:Oxygen