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Author Pedrouso, A.; del Rio, A.V.; Morales, N.; Vazquez-Padin, J.R.; Campos, J.L.; Mendez, R.; Mosquera-Corral, A.
Title Nitrite oxidizing bacteria suppression based on in-situ free nitrous acid production at mainstream conditions Type
Year 2017 Publication Separation And Purification Technology Abbreviated Journal Sep. Purif. Technol.
Volume 186 Issue Pages 55-62
Keywords Ammonium oxidizing bacteria; Flocculent sludge; Free nitrous acid; Mainstream; Nitrite oxidizing bacteria; Partial nitritation
Abstract The application of autotrophic nitrogen removal processes in the main line of wastewater treatment plants will contribute to achieve its self-energy-sufficiency. However, the effective suppression of nitrite oxidizing bacteria (NOB) activity at the conditions of low temperature and low ammonium concentration (mainstream conditions) was identified as one of the main bottlenecks. In this study, stable partial nitritation at 16 degrees C and 50 mg NH4+-N/L was achieved maintaining inside the reactor free nitrous acid (FNA) concentrations inhibitory for NOB (>0.02 mg HNO2-N/L), without dissolved oxygen concentration control, The FNA inhibitory concentration was generated by the partial nitritation process, and its stimulation was studied with two different inhibitors: sodium azide and nitrite. The microbiological analysis revealed that, throughout the operational period with inhibitory FNA levels, the NOB populations (dominated by Nitrospira) were effectively washed out from the reactor. This is an advantage that allowed maintaining a good stability of the process, even when the FNA concentration was not enough to inhibit the NOB, taking about 40 days to develop significant activity. The observed delay on the NOB development is expected to enable the establishment of corrective actions to avoid the partial nitritation destabilization. The use of the FNA to achieve a stable partial nitritation process is recommended to profit from the natural pH decrease associated to the nitritation process and from its favoured accumulation at low temperatures as those from the mainstream. In this research study an analysis about the influence of ammonium and alkalinity concentrations was also performed to know in which scenarios the FNA inhibitory concentration can be achieved. (C) 2017 Elsevier B.V. All rights reserved.
Address [Pedrouso, Alba; del Rio, Angeles Val; Mendez, Ramon; Mosquera-Corral, Anuska] Univ Santiago de Compostela, Sch Engn, Dept Chem Engn, E-15705 Santiago De Compostela, Spain, Email: alba.pedrouso@usc.es;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1383-5866 ISBN Medium
Area Expedition Conference
Notes WOS:000406730700007 Approved
Call Number UAI @ eduardo.moreno @ Serial 755
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