Modeling the PAO–GAO competition: Effects of carbon source, pH and temperature

Lopez-Vazquez, Carlos M., Oehmen, Adrian, Hooijmans, Christine M., Brdjanovic, Damir, Gijzen, Huub J., Yuan, Zhiguo and van Loosdrecht, Mark C. M. (2009) Modeling the PAO–GAO competition: Effects of carbon source, pH and temperature. Water Research, 43 2: 450-462. doi:10.1016/j.watres.2008.10.032

Author Lopez-Vazquez, Carlos M.
Oehmen, Adrian
Hooijmans, Christine M.
Brdjanovic, Damir
Gijzen, Huub J.
Yuan, Zhiguo
van Loosdrecht, Mark C. M.
Title Modeling the PAO–GAO competition: Effects of carbon source, pH and temperature
Journal name Water Research   Check publisher's open access policy
ISSN 0043-1354
Publication date 2009-02-01
Year available 2008
Sub-type Article (original research)
DOI 10.1016/j.watres.2008.10.032
Open Access Status DOI
Volume 43
Issue 2
Start page 450
End page 462
Total pages 13
Place of publication London, United Kingdom
Publisher I W A Publishing
Language eng
Subject C1
100305 Industrial Microbiology (incl. Biofeedstocks)
960912 Urban and Industrial Water Management
0905 Civil Engineering
Abstract The influence of different carbon sources (acetate to propionate ratios), temperature and pH levels on the competition between polyphosphate- and glycogen-accumulating organisms (PAO and GAO, respectively) was evaluated using a metabolic model that incorporated the carbon source, temperature and pH dependences of these microorganisms. The model satisfactorily described the bacterial activity of PAO (Accumulibacter) and GAO (Competibacter and Alphaproteobacteria-GAO) laboratory-enriched cultures cultivated on propionate (HPr) and acetate (HAc) at standard conditions (20 °C and pH 7.0). Using the calibrated model, the effects of different influent HAc to HPr ratios (100–0, 75–25, 50–50 and 0–100%), temperatures (10, 20 and 30 °C) and pH levels (6.0, 7.0 and 7.5) on the competition among Accumulibacter, Competibacter and Alphaproteobacteria-GAO were evaluated. The main aim was to assess which conditions were favorable for the existence of PAO and, therefore, beneficial for the biological phosphorus removal process in sewage treatment plants. At low temperature (10 °C), PAO were the dominant microorganisms regardless of the used influent carbon source or pH. At moderate temperature (20 °C), PAO dominated the competition when HAc and HPr were simultaneously supplied (75–25 and 50–50% HAc to HPr ratios). However, the use of either HAc or HPr as sole carbon source at 20 °C was not favorable for PAO unless a high pH was used (7.5). Meanwhile, at higher temperature (30 °C), GAO tended to be the dominant microorganisms. Nevertheless, the combined presence of acetate and propionate in the influent (75–25 and 50–50% HAc to HPr ratios) as well as a high pH (7.5) appear to be potential factors to favor the metabolism of PAO over GAO at higher sewage temperature (30 °C).
Keyword Enhanced biological phosphorus removal (EBPR)
Metabolic modeling
Microbial competition
Volatile fatty acids (VFA)
Poly-β-hydroxyalkanoates (PHA)
Defluviicoccus vanus
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

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Created: Tue, 23 Jun 2009, 21:33:00 EST by Sarah Borsellino on behalf of Advanced Water Management Centre