title: Methanogenic population dynamics and performance of an anaerobic membrane bioreactor (AnMBR) treating swine manure under high shear conditions.
abstract: A 6-L, completely mixed anaerobic bioreactor with an external ultrafiltration membrane module was operated for 300 days to evaluate the startup and performance of an anaerobic membrane bioreactor (AnMBR) treating swine manure. The reactor had a successful startup at the initial loading rate of 1g volatile solids (VS)/L/day. After a two-fold increase in loading rate followed by a sudden, two-fold increase in flow velocity through the membrane module on day 75, the performance of the AnMBR deteriorated as measured by volatile fatty acid (VFA) accumulation, decrease in pH, and decrease in biogas production. The methanogenic population dynamics in the reactor were monitored with terminal restriction fragment length polymorphism (T-RFLP). Changes in the relative levels of Methanosarcinaceae and Methanosaetaceae were consistent with changes in VFA concentrations, i.e., high and low levels of acetate corresponded to a high abundance of Methanosarcinaceae and Methanosaetaceae, respectively. The levels of hydrogenotrophic methanogens of the order of Methanomicrobiales increased during decreased reactor performance suggesting that syntrophic interactions involving hydrogenotrophic methanogens remained intact regardless of the degree of shear in the AnMBR.
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 N Mathews Ave, IL 61801, USA.
authors.forename: Sudini I
authors.initials: SI
authors.lastname: Padmasiri
authors.forename: Jiangzhao
authors.initials: J
authors.lastname: Zhang
authors.forename: Mark
authors.initials: M
authors.lastname: Fitch
authors.forename: Birgir
authors.initials: B
authors.lastname: Norddahl
authors.forename: Eberhard
authors.initials: E
authors.lastname: Morgenroth
authors.forename: Lutgarde
authors.initials: L
authors.lastname: Raskin
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D019149:Bioreactors; D019605:Euryarchaeota / Q000235:genetics*; D008372:Manure / Q000032:analysis* / Q000382:microbiology*; D008567:Membranes, Artificial; D008697:Methane / Q000737:chemistry*; D033081:Shear Strength; D013552:Swine; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods
chemical_list: D008372:Manure; D008567:Membranes, Artificial; D008697:Methane