Nitrite accumulation inside sludge flocs significantly influencing nitrous oxide production by ammonium-oxidizing bacteria

Chen, X; Yuan, Z; Ni, BJ

Nitrite accumulation inside sludge flocs significantly influencing nitrous oxide production by ammonium-oxidizing bacteria

Chen, X Yuan, Z Ni, BJ

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Publication Type:: Journal Article
Citation:: Water Research, 2018, 143 pp. 99 - 108
Issue Date:: 2018-10-15

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Field	Value	Language
dc.contributor.author	Chen, X	en_US
dc.contributor.author	Yuan, Z	en_US
dc.contributor.author	Ni, BJ https://orcid.org/0000-0002-1129-7837	en_US
dc.date.available	2018-06-13	en_US
dc.date.issued	2018-10-15	en_US
dc.identifier.citation	Water Research, 2018, 143 pp. 99 - 108	en_US
dc.identifier.issn	0043-1354	en_US
dc.identifier.uri	http://hdl.handle.net/10453/132325
dc.description.abstract	© 2018 Elsevier Ltd This work aims to clarify the role of potential nitrite (NO2−) accumulation inside sludge flocs in N2O production by ammonium-oxidizing bacteria (AOB) at different dissolved oxygen (DO) levels with focus on the conditions of no significant bulk NO2− accumulation (<0.2 mg N/L). To this end, an augmented nitrifying sludge with much higher abundance of nitrite-oxidizing bacteria (NOB) than AOB was enriched and then used for systematically designed batch tests, which targeted a range of DO levels from 0 to 3.0 mg O2/L at a fixed ammonium concentration of 10 mg N/L. A two-pathway N2O model was applied to facilitate the interpretation of batch experimental data, thus shedding light on the relationships between N2O production pathways and key process parameters (i.e., DO and NO2− accumulation inside sludge flocs). The results demonstrated (i) the biomass specific N2O production rate firstly increased and then decreased with DO, with the maximum value of 3.03 ± 0.05 mg N/h/g VSS obtained at DO level of 0.75 mg O2/L, (ii) the AOB denitrification pathway for N2O production was dominant (98.0%) at all DO levels tested even without significant bulk NO2− accumulation (<0.2 mg N/L) observed in the system, but its contribution decreased with DO, (iii) DO had a positive impact on the hydroxylamine pathway for N2O production which therefore increased with DO, and (iv) the nitrite accumulation existed inside the sludge flocs and induced significant N2O production from the AOB denitrification pathway.	en_US
dc.relation.ispartof	Water Research	en_US
dc.relation.isbasedon	10.1016/j.watres.2018.06.025	en_US
dc.subject.classification	Environmental Engineering	en_US
dc.subject.mesh	Bacteria	en_US
dc.subject.mesh	Nitrites	en_US
dc.subject.mesh	Oxygen	en_US
dc.subject.mesh	Nitrous Oxide	en_US
dc.subject.mesh	Ammonium Compounds	en_US
dc.subject.mesh	Hydroxylamine	en_US
dc.subject.mesh	Bioreactors	en_US
dc.subject.mesh	Sewage	en_US
dc.subject.mesh	Waste Disposal, Fluid	en_US
dc.subject.mesh	Oxidation-Reduction	en_US
dc.subject.mesh	Flocculation	en_US
dc.subject.mesh	Models, Theoretical	en_US
dc.title	Nitrite accumulation inside sludge flocs significantly influencing nitrous oxide production by ammonium-oxidizing bacteria	en_US
dc.type	Journal Article
utslib.citation.volume	143	en_US
utslib.for	0904 Chemical Engineering	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology/School of Civil and Environmental Engineering
pubs.organisational-group	/University of Technology Sydney/Strength - CTWW - Centre for Technology in Water and Wastewater Treatment
utslib.copyright.status	closed_access
pubs.publication-status	Published	en_US
pubs.volume	143	en_US

Abstract:

© 2018 Elsevier Ltd This work aims to clarify the role of potential nitrite (NO2−) accumulation inside sludge flocs in N2O production by ammonium-oxidizing bacteria (AOB) at different dissolved oxygen (DO) levels with focus on the conditions of no significant bulk NO2− accumulation (<0.2 mg N/L). To this end, an augmented nitrifying sludge with much higher abundance of nitrite-oxidizing bacteria (NOB) than AOB was enriched and then used for systematically designed batch tests, which targeted a range of DO levels from 0 to 3.0 mg O2/L at a fixed ammonium concentration of 10 mg N/L. A two-pathway N2O model was applied to facilitate the interpretation of batch experimental data, thus shedding light on the relationships between N2O production pathways and key process parameters (i.e., DO and NO2− accumulation inside sludge flocs). The results demonstrated (i) the biomass specific N2O production rate firstly increased and then decreased with DO, with the maximum value of 3.03 ± 0.05 mg N/h/g VSS obtained at DO level of 0.75 mg O2/L, (ii) the AOB denitrification pathway for N2O production was dominant (98.0%) at all DO levels tested even without significant bulk NO2− accumulation (<0.2 mg N/L) observed in the system, but its contribution decreased with DO, (iii) DO had a positive impact on the hydroxylamine pathway for N2O production which therefore increased with DO, and (iv) the nitrite accumulation existed inside the sludge flocs and induced significant N2O production from the AOB denitrification pathway.

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http://hdl.handle.net/10453/132325