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Published (Version of record)CC BY V4.0, Open Access
Published (Version of record)CC BY V4.0, Open
Journal article
Coarse bubble mixing in anoxic zone greatly stimulates nitrous oxide emissions from biological nitrogen removal process
Water research X, Vol.25, 100263
01/12/2024
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Source: InCites
Abstract
The biological nitrogen removal process in wastewater treatment inevitably produces nitrous oxide (N2O), a potent greenhouse gas. Coarse bubble mixing is widely employed in wastewater treatment processes to mix anoxic tanks; however, its impacts on N2O emissions are rarely reported. This study investigates the effects of coarse bubble mixing on N2O emissions in a pilot-scale mainstream nitrite shunt reactor over a 50-day steady-state period. Online and offline N2O monitoring campaigns show that coarse bubble mixing in the anoxic zones significantly elevates N2O emissions, yielding an extremely high emission factor of 15.5 ± 3.5%. Intensive sampling and isotopic analyses suggest that the elevated emissions are primarily due to the inhibition of the N2O denitrification process by oxygen in the anoxic phase introduced by coarse bubbling. Substituting coarse bubble mixing with submersible pump mixing resulted in a substantial reduction of N2O emissions, decreasing the emission factor by an order of magnitude to 1.2 ± 0.8%. The findings reveal that a previously overlooked factor, coarse bubble mixing, can significantly stimulate N2O emissions. The use of coarse bubble mixing in anoxic tanks of biological nitrogen removal warrants caution.
Details
- Title
- Coarse bubble mixing in anoxic zone greatly stimulates nitrous oxide emissions from biological nitrogen removal process
- Creators
- Haoran Duan (Author) - The University of QueenslandShane Watt (Author) - Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, AustraliaDirk Erler (Author) - Southern Cross UniversityHuijuan Li (Author) - Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, AustraliaZhiyao Wang (Author) - The University of QueenslandMin Zheng (Author) - Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales 2052, AustraliaShihu Hu (Author) - The University of QueenslandLiu Ye (Author) - The University of QueenslandZhiguo Yuan (Author) - City University of Hong Kong
- Publication Details
- Water research X, Vol.25, 100263
- Publisher
- Elsevier Ltd; AMSTERDAM
- Grant note
- This study was funded by the Advance Queensland Innovation Partnerships (AQIP) scheme. The authors acknowledge the strong support from industry partners: Urban Utilities (QLD), City of Gold Coast, Wide Bay Water (Fraser Coast Regional Council), South Australia Water Corporation and Western Australia Water Corporation. Haoran Duan is a recipient of the Australian Research Council (ARC) Early Career Industry Fellowship (IE230100422). Zhiyao Wang would like to acknowledge the support of the Early Career Researcher Philanthropic Grants 2023 from University of Queensland. Shihu Hu is the is the awardee of ARC Industry Fellowship (IM230100030). Zhiguo Yuan is a Global STEM Professor jointly funded by the Innovation, Technology and Industry Bureau (“ITIB”) and Education Bureau (“EDB”) of the Government of the Hong Kong Special Administrative Region, China and acknowledges financial support from the Hong Kong Jockey Club for the JC STEM Lab of Sustainable Urban Water Management.
- Identifiers
- 991013225798802368
- Copyright
- © 2024 The Author(s).
- Academic Unit
- Faculty of Science and Engineering; Science
- Language
- English
- Resource Type
- Journal article