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

2008 ◽  
Vol 42 (22) ◽  
pp. 8260-8265 ◽  
Author(s):  
Yan Zhou ◽  
Maite Pijuan ◽  
Raymond J. Zeng ◽  
Zhiguo Yuan
Keyword(s):  
Nitrous Oxide ◽  
Phosphorus Removal ◽  
Nitrous Acid ◽  
Acid Inhibition ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Oxide Reduction ◽  
Free Nitrous Acid ◽  
Nitrous Oxide Reduction ◽  
Biological Phosphorus

Could nitrite/free nitrous acid favour GAOs over PAOs in enhanced biological phosphorus removal systems?

2011 ◽  
Vol 63 (2) ◽  
pp. 345-351 ◽  
Author(s):  
M. Pijuan ◽  
L. Ye ◽  
Z. Yuan
Keyword(s):  
Phosphorus Removal ◽  
Nitrous Acid ◽  
Wastewater Treatment Plants ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Inhibitory Effects ◽  
Nitrogen Gas ◽  
Free Nitrous Acid ◽  
Polyphosphate Accumulating Organisms ◽  
Biological Phosphorus

Enhanced biological phosphorus removal (EBPR) normally occurs together with nitrogen removal in wastewater treatment plants (WWTPs). In recent years, efforts have been devoted to remove nitrogen via the nitrite pathway (oxidation of ammonia to nitrite and reduction of nitrite to nitrogen gas without going through nitrate), reducing the requirement for carbon and oxygen in the plant. However nitrite and free nitrous acid (FNA), the protonated species of nitrite, have been shown to cause EBPR deterioration under certain concentrations. This study provides a direct comparison between the different levels of FNA inhibition in the aerobic processes of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) by reviewing the studies published in this area. Also, new data is presented assessing the FNA effect on the anaerobic metabolism of these two groups of bacteria. Overall, FNA has shown inhibitory effects on most of the processes involved in the metabolism of PAOs and GAOs. However, the inhibition-initiation levels are different between different processes and, even more importantly between the two groups. In general, PAOs appear to be more affected than GAOs at the same level of FNA, thus giving GAOs competitive advantage over PAOs in EBPR systems when nitrite is present.

scholarly journals An efficient process for wastewater treatment to mitigate free nitrous acid generation and its inhibition on biological phosphorus removal

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Jianwei Zhao ◽  
Dongbo Wang ◽  
Xiaoming Li ◽  
Qi Yang ◽  
Hongbo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Nitrous Acid ◽  
Biological Phosphorus Removal ◽  
Free Nitrous Acid ◽  
Efficient Process ◽  
Acid Generation ◽  
Biological Phosphorus

scholarly journals Effect of Free Nitrous Acid on Nitrous Oxide Production and Denitrifying Phosphorus Removal by Polyphosphorus-Accumulating Organisms in Wastewater Treatment

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Zhijia Miao ◽  
Duo Li ◽  
Shan Guo ◽  
Zhirui Zhao ◽  
Xiaofeng Fang ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Phosphorus Removal ◽  
Nitrous Acid ◽  
Phosphorus Uptake ◽  
Complete Removal ◽  
Phosphorus Metabolism ◽  
Biological Phosphorus Removal ◽  
Denitrifying Phosphorus Removal ◽  
Free Nitrous Acid ◽  
Nitrous Oxide Production

The inhibition of free nitrous acid (FNA) on denitrifying phosphorus removal has been widely reported for enhanced biological phosphorus removal; however, few studies focus on the nitrous oxide (N2O) production involved in this process. In this study, the effects of FNA on N2O production and anoxic phosphorus metabolism were investigated using phosphorus-accumulating organisms (PAOs) culture highly enriched (91±4%) inCandidatus Accumulibacter phosphatis. Results show that the FNA concentration notably inhibited anoxic phosphorus metabolism and phosphorus uptake. Poly-β-hydroxyalkanoate (PHA) degradation was completely inhibited when the FNA concentration was approximately 0.0923 mgHNO2-N/L. Higher initial FNA concentrations (0.00035 to 0.0103 mgHNO2-N/L) led to more PHA consumption/TN (0.444 to 0.916 mmol-C/(mmol-N·gVSS)). Moreover, it was found that FNA, rather than nitrite and pH, was likely the true inhibitor of N2O production. The highest proportion of N2O to TN was 78.42% at 0.0031 mgHNO2-N/L (equivalent to 42.44 mgNO2-N/L at pH 7.5), due to the simultaneous effects of FNA on the subsequent conversion of NO2into N2O and then into N2. The traditional nitrite knee point can only indicate the exhaustion of nitrite, instead of the complete removal of TN.

scholarly journals Denitrifying capabilities of Tetrasphaera and their contribution towards nitrous oxide production in enhanced biological phosphorus removal processes

2018 ◽  
Vol 137 ◽  
pp. 262-272 ◽  
Author(s):  
Ricardo Marques ◽  
Anna Ribera-Guardia ◽  
Jorge Santos ◽  
Gilda Carvalho ◽  
Maria A.M. Reis ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Phosphorus Removal ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Oxide Production ◽  
Nitrous Oxide Production ◽  
Removal Processes ◽  
Biological Phosphorus

Heterotrophic Kinetic Parameter Estimation for Enhanced Biological Phosphorus Removal Processes Operated in Conventional and Membrane-Assisted Modes

2006 ◽  
Vol 41 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Zhe Zhang ◽  
Eric R. Hall
Keyword(s):  
Parameter Estimation ◽  
Phosphorus Removal ◽  
Growth Yield ◽  
Pilot Scale ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Nitrogen And Phosphorus ◽  
Parameter Values ◽  
The Impact ◽  
Biological Phosphorus

Abstract Parameter estimation and wastewater characterization are crucial for modelling of the membrane enhanced biological phosphorus removal (MEBPR) process. Prior to determining the values of a subset of kinetic and stoichiometric parameters used in ASM No. 2 (ASM2), the carbon, nitrogen and phosphorus fractions of influent wastewater at the University of British Columbia (UBC) pilot plant were characterized. It was found that the UBC wastewater contained fractions of volatile acids (SA), readily fermentable biodegradable COD (SF) and slowly biodegradable COD (XS) that fell within the ASM2 default value ranges. The contents of soluble inert COD (SI) and particulate inert COD (XI) were somewhat higher than ASM2 default values. Mixed liquor samples from pilot-scale MEBPR and conventional enhanced biological phosphorus removal (CEBPR) processes operated under parallel conditions, were then analyzed experimentally to assess the impact of operation in a membrane-assisted mode on the growth yield (YH), decay coefficient (bH) and maximum specific growth rate of heterotrophic biomass (µH). The resulting values for YH, bH and µH were slightly lower for the MEBPR train than for the CEBPR train, but the differences were not statistically significant. It is suggested that MEBPR simulation using ASM2 could be accomplished satisfactorily using parameter values determined for a conventional biological phosphorus removal process, if MEBPR parameter values are not available.

Full Scale Investigations on Enhanced Biological Phosphorus Removal – P-Release in the Anaerobic Reactor

1994 ◽  
Vol 29 (7) ◽  
pp. 153-156 ◽  
Author(s):  
D. Wedi ◽  
P. A. Wilderer
Keyword(s):  
Phosphorus Removal ◽  
Full Scale ◽  
Process Conditions ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Anaerobic Reactor ◽  
P Release ◽  
Acinetobacter Sp ◽  
Biological Phosphorus ◽  
P Removal

Most of the fundamental processes responsible for enhanced biological phosphorus removal (EBPR) were obtained through laboratory tests under defined conditions with pure or enriched cultures. Acinetobacter sp. was identified as the most important group of bacteria responsible for bio-P removal. Full scale data showed, however, that laboratory results do not match full scale results well enough. There is a lack of data on the effects of sub-optimal process conditions such as inadequate availability of volatile fatty acids (VFA), high nitrate recycle, storm water inflow or low temperatures. In this paper the results of full scale experiments on P-release are presented and compared with theoretical values. Measurements at a full scale Phoredox-system showed a surprisingly low P-release in the anaerobic reactor. Only 4 to 10% of the phosphorus in the activated sludge was released in the bulk liquid. With laboratory batch-tests, a maximum of 20% of the P in the sludge could be released. It is assumed that under the prevailing process conditions either the fraction of Acinetobacter sp. was very small, or bacteria other than Acinetobacter sp. were responsible for the P-removal, or most of the phosphorus was bound chemically but mediated by biological processes.

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