The effect of pH on the competition between polyphosphate-accumulating organisms and glycogen-accumulating organisms.
Water Res
; 39(15): 3727-37, 2005 Sep.
Article
em En
| MEDLINE
| ID: mdl-16098556
ABSTRACT
In enhanced biological phosphorus removal (EBPR) processes, glycogen-accumulating organisms (GAOs) may compete with polyphosphate-accumulating organisms (PAOs) for the often-limited carbon substrates, potentially resulting in disturbances to phosphorus removal. A detailed investigation of the effect of pH on the competition between PAOs and GAOs is reported in this study. The results show that a high external pH ( approximately 8) provided PAOs with an advantage over GAOs in EBPR systems. The phosphorus removal performance improved due to a population shift favouring PAOs over GAOs, which was shown through both chemical and microbiological methods. Two lab-scale reactors fed with propionate as the carbon source were subjected to an increase in pH from 7 to 8. The phosphorus removal and PAO population (as measured by quantitative fluorescence in situ hybridisation analysis of "Candidatus Accumulibacter phosphatis") increased in each system, where the PAOs appeared to out-compete a group of Alphaproteobacteria GAOs. A considerable improvement in the P removal was also observed in an acetate fed reactor, where the GAO population (primarily "Candidatus Competibacter phosphatis") decreased substantially after a similar increase in the pH. The results from this study suggest that pH could be used as a control parameter to reduce the undesirable proliferation of GAOs and improve phosphorus removal in EBPR systems.
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Base de dados:
MEDLINE
Assunto principal:
Fósforo
/
Poluentes Químicos da Água
/
Alphaproteobacteria
/
Gammaproteobacteria
Idioma:
En
Revista:
Water Res
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Austrália