title: Influence of dissolved oxygen concentration on the start-up of the anammox-based process: ELAN®.
abstract: The anammox-based process ELAN® was started-up in two different sequencing batch reactor (SBR) pilot plant reactors treating municipal anaerobic digester supernatant. The main difference in the operation of both reactors was the dissolved oxygen (DO) concentration in the bulk liquid. SBR-1 was started at a DO value of 0.4 mg O2/L whereas SBR-2 was started at DO values of 3.0 mg O2/L. Despite both reactors working at a nitrogen removal rate of around 0.6 g N/(L d), in SBR-1, granules represented only a small fraction of the total biomass and reached a diameter of 1.1 mm after 7 months of operation, while in SBR-2 the biomass was mainly composed of granules with an average diameter of 3.2 mm after the same operational period. Oxygen microelectrode profiling revealed that granules from SBR-2 where only fully penetrated by oxygen with DO concentrations of 8 mg O2/L while granules from SBR-1 were already oxygen penetrated at DO concentrations of 1 mg O2/L. In this way granules from SBR-2 performed better due to the thick layer of ammonia oxidizing bacteria, which accounted for up to 20% of all the microbial populations, which protected the anammox bacteria from non-suitable liquid media conditions.
authors.affiliation: FCC Aqualia, Guillarei WWTP, Tui, E-36720, Spain E-mail: nicolas.morales.pereira@fcc.es.
authors.forename: N
authors.initials: N
authors.lastname: Morales
authors.affiliation: Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Lope Gomez de Marzoa s/n, E-15705 Santiago de Compostela, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Val del Río
authors.affiliation: FCC Aqualia, Guillarei WWTP, Tui, E-36720, Spain E-mail: nicolas.morales.pereira@fcc.es.
authors.forename: J R
authors.initials: JR
authors.lastname: Vázquez-Padín
authors.affiliation: FCC Aqualia, Guillarei WWTP, Tui, E-36720, Spain E-mail: nicolas.morales.pereira@fcc.es.
authors.forename: R
authors.initials: R
authors.lastname: Gutiérrez
authors.affiliation: FCC Aqualia, Guillarei WWTP, Tui, E-36720, Spain E-mail: nicolas.morales.pereira@fcc.es.
authors.forename: R
authors.initials: R
authors.lastname: Fernández-González
authors.affiliation: FCC Aqualia, Guillarei WWTP, Tui, E-36720, Spain E-mail: nicolas.morales.pereira@fcc.es.
authors.forename: P
authors.initials: P
authors.lastname: Icaran
authors.affiliation: FCC Aqualia, Guillarei WWTP, Tui, E-36720, Spain E-mail: nicolas.morales.pereira@fcc.es.
authors.forename: F
authors.initials: F
authors.lastname: Rogalla
authors.affiliation: Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Lope Gomez de Marzoa s/n, E-15705 Santiago de Compostela, Spain; Faculty of Engineering and Science, University Adolfo Ibáñez, Avda Padre Hurtado 750, Viña del Mar, Chile.
authors.forename: J L
authors.initials: JL
authors.lastname: Campos
authors.affiliation: Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Lope Gomez de Marzoa s/n, E-15705 Santiago de Compostela, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Méndez
authors.affiliation: Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Lope Gomez de Marzoa s/n, E-15705 Santiago de Compostela, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Mosquera-Corral
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D012722:Sewage / Q000032:analysis*; D014865:Waste Disposal, Fluid
chemical_list: D012722:Sewage; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen