title: Biomass aggregation influences NaN3short-term effects on anammox bacteria activity.
abstract: The main bottleneck to maintain the long-term stability of the partial nitritation-anammox processes, especially those operated at low temperatures and nitrogen concentrations, is the undesirable development of nitrite oxidizing bacteria (NOB). When this occurs, the punctual addition of compounds with the capacity to specifically inhibit NOB without affecting the process efficiency might be of interest. Sodium azide (NaN3) is an already known NOB inhibitor which at low concentrations does not significantly affect the ammonia oxidizing bacteria (AOB) activity. However, studies about its influence on anammox bacteria are unavailable. For this reason, the objective of the present study was to evaluate the effect of NaN3on the anammox activity. Three different types of anammox biomass were used: granular biomass comprising AOB and anammox bacteria (G1), anammox enriched granules (G2) and previous anammox granules disaggregated (F1). No inhibitory effect of NaN3was measured on G1 sludge. However, the anammox activity decreased in the case of G2 and F1. Granular biomass activity was less affected (IC5090 mg/L, G2) than flocculent one (IC505 mg/L, F1). Summing up, not only does the granular structure protect the anammox bacteria from the NaN3inhibitory effect, but also the AOB act as a barrier decreasing the inhibition.
authors.affiliation: Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, Santiago de Compostela E-15705, Spain E-mail: alba.pedrouso@usc.es.
authors.forename: A
authors.initials: A
authors.lastname: Pedrouso
authors.affiliation: Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, Santiago de Compostela E-15705, Spain E-mail: alba.pedrouso@usc.es.
authors.forename: A
authors.initials: A
authors.lastname: Val Del Río
authors.affiliation: Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar, Chile.
authors.forename: J L
authors.initials: JL
authors.lastname: Campos
authors.affiliation: Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, Santiago de Compostela E-15705, Spain E-mail: alba.pedrouso@usc.es.
authors.forename: R
authors.initials: R
authors.lastname: Méndez
authors.affiliation: Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, Santiago de Compostela E-15705, Spain E-mail: alba.pedrouso@usc.es.
authors.forename: A
authors.initials: A
authors.lastname: Mosquera-Corral
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D000693:Anaerobiosis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D018533:Biomass; D058440:Denitrification / Q000187:drug effects; D005427:Flocculation / Q000187:drug effects; D009609:Nitrous Oxide / Q000032:analysis; D010084:Oxidation-Reduction / Q000187:drug effects; D010316:Particle Size; D019810:Sodium Azide / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D064751:Ammonium Compounds; D019810:Sodium Azide; D009609:Nitrous Oxide