Skip to main content

Phosphorus Removal and PAOs Populations at a Full-Scale Integrated Fixed-Film Activated Sludge (IFAS) Plant

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial


Integrated Fixed-Film Activated Sludge (IFAS) has been shown to be successful for the enhancement of nitrification and denitrification in conventional activated sludge systems, however only a few pilot scale studies have included Enhanced Biological Phosphorus Removal (EBPR) in their IFAS set up. This study reports for the first time an evaluation of the performance of biological phosphorus removal, including kinetics, in a full scale plant that was designed as an IFAS-BNR; moreover this study gives some insight on the identification and quantification of the polyphosphate accumulating organism (PAO) populations and their distribution on the fixed-film (media) and in the suspended activated sludge. In contrast to the general expectation that PAOs only reside in the suspended mixed liquor in an IFAS system, PAO presence and activity was observed in biofilms on the media. However, only a small percentage of the total PAO activity was associated with the media and the measured activity seemed to be associated with thicker biofilm that probably created diffusion limitation along the film depth. Observation of PAOs and Accumulibacter–like PAOs indicated that Accumulibacter were present in both biofilm and mixed liquor from stage 1 and stage 2 aeration basins. Other PAOs that did not appear to be related to Accumulibater were present in the system but they have not yet unidentified. Negative results were obtained with fluorescent in situ hybridization probes targeting Competibacter, but tetrad forming organisms were observed using staining techniques.

Document Type: Research Article


Publication date: 2008-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more