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BioMed Research International
Volume 2017 (2017), Article ID 6571671, 7 pages
Research Article

Effect of Free Ammonia, Free Nitrous Acid, and Alkalinity on the Partial Nitrification of Pretreated Pig Slurry, Using an Alternating Oxic/Anoxic SBR

1Engineering and Environmental Biotechnology Group, Environmental Science Faculty & Center EULA-Chile, University of Concepción, P.O. Box 160-C, Concepción, Chile
2School of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso, 2362803 Valparaíso, Chile
3Laboratory of Biotechnology, Environment and Engineering, Faculty of Engineering, University of Playa Ancha, 2340000 Valparaíso, Chile
4Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, 2503500 Viña del Mar, Chile
5Department of Chemical and Environmental Engineering, University Federico Santa María, 2390123 Valparaíso, Chile
6Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain

Correspondence should be addressed to Marisol Belmonte

Received 18 May 2017; Accepted 1 August 2017; Published 6 September 2017

Academic Editor: Giuseppe Olivieri

Copyright © 2017 Marisol Belmonte et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The effect of free ammonia (NH3 or FA), free nitrous acid (HNO2 or FNA), and total alkalinity (TA) on the performance of a partial nitrification (PN) sequencing batch reactor (SBR) treating anaerobically pretreated pig slurry was studied. The SBR was operated under alternating oxic/anoxic (O/A) conditions and was fed during anoxic phases. This strategy allowed using organic matter to partially remove nitrite () and nitrate () generated during oxic phases. The desired to ratio of 1.3 g N/g N was obtained when an Ammonium Loading Rate (ALR) of 0.09 g -N/L·d was applied. The system was operated at a solid retention time (SRT) of 15–20 d and dissolved oxygen (DO) levels higher than 3 mg O2/L during the whole operational period. PN mainly occurred caused by the inhibitory effect of FNA on nitrite oxidizing bacteria (NOB). Once HNO2 concentration was negligible, was fully oxidized to in spite of the presence of FA. The use of biomass acclimated to ammonium as inoculum avoided a possible effect of FA on NOB activity.