Free Nitrous Acid Inhibition on Nitrous Oxide Reduction by a Denitrifying-Enhanced Biological Phosphorus Removal Sludge

Zhou, Yan, Pijuan, Maite, Zeng, Raymond J. and Yuan, Zhiguo (2008) Free Nitrous Acid Inhibition on Nitrous Oxide Reduction by a Denitrifying-Enhanced Biological Phosphorus Removal Sludge. Environmental Science & Technology, 42 22: 8260-8265. doi:10.1021/es800650j

Author Zhou, Yan
Pijuan, Maite
Zeng, Raymond J.
Yuan, Zhiguo
Title Free Nitrous Acid Inhibition on Nitrous Oxide Reduction by a Denitrifying-Enhanced Biological Phosphorus Removal Sludge
Journal name Environmental Science & Technology   Check publisher's open access policy
ISSN 0013-936X
Publication date 2008-11-15
Year available 2008
Sub-type Article (original research)
DOI 10.1021/es800650j
Open Access Status DOI
Volume 42
Issue 22
Start page 8260
End page 8265
Total pages 6
Place of publication Washington, D.C., U.S.A.
Publisher American Chemical Society
Language eng
Subject C1
9699 Other Environment
090409 Wastewater Treatment Processes
Abstract Denitrifying sulfur conversion-assisted enhanced biological phosphorus removal (DS-EBPR) has recently been developed for simultaneously removing nitrogen and phosphorus from saline sewage with minimal sludge production. This novel process could potentially enable sustainable wastewater treatment. Yet, the core functional bacteria and their roles are unknown. Here, we used high-throughput 16S rRNA gene sequencing coupled with principal coordinates analysis and ANOVA with Tukey's test to unravel the spatiotemporal heterogeneity of functional bacteria and their synergetic and competitive interactions. We did not find any obvious spatial heterogeneity within the bacterial population in different size-fractionated sludge samples, but the main functional bacteria varied significantly with operation time. Thauera was enriched (9.26~13.63%) as become the core functional genus in the DS-EBPR reactors and links denitrifying phosphorus removal to sulfide oxidation. The other two functional genera were sulfate-reducing Desulfobacter (4.31~12.85%) and nitrate-reducing and sulfide-oxidizing Thiobacillus (4.79~9.92%). These bacteria cooperated in the DS-EBPR process: Desulfobacter reduced sulfate to sulfide for utilization by Thiobacillus, while Thauera and Thiobacillus competed for nitrate and sulfide as well as Thauera and Desulfobacter competed for acetate. This study is the first to unravel the interactions among core functional bacteria in DS-EBPR, thus improving our understanding of how this removal process works.
Formatted abstract
Nitrite has generally been recognized as an inhibitor of N2O reduction during denitrification. This inhibitory effect is investigated under various pH conditions using a denitrifying-enhanced biological phosphorus removal (EBPR) sludge. The degree of inhibition was observed to correlate much more strongly with the free nitrous acid (FNA) concentration than with the nitrite concentration, suggesting that FNA, rather than nitrite, is likely the true inhibitor on N2O reduction. Fifty percent inhibition was observed at an FNA concentration of 0.0007−0.001 mg HNO2-N/L (equivalent to approximately 3−4 mg NO2−-N/L at pH 7), while complete inhibition occurred when the FNA concentration was greater than 0.004 mg HNO2-N/L. The results also suggest that the inhibition on N2O reduction was not due to the electron competition between N2O and NO2− reductases. The inhibition was found to be reversible, with the rate of recovery independent of the duration of the inhibition, but dependent on the concentration of FNA the biomass was exposed to during the inhibition period. A higher FNA concentration caused slower recovery.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2009 Higher Education Research Data Collection
Advanced Water Management Centre Publications
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Citation counts: TR Web of Science Citation Count  Cited 117 times in Thomson Reuters Web of Science Article | Citations
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Created: Wed, 08 Apr 2009, 00:55:39 EST by Suzanne Read on behalf of Advanced Water Management Centre