Skip to main content

A PRACTICAL METHOD FOR QUANTIFICATION OF PAO AND GAO POPULATIONS IN ACTIVATED SLUDGE SYSTEMS

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial

Abstract:

Enhanced Biological Phosphorus Removal (EBPR) from wastewater relies on the enrichment of activated sludge with Phosphorus Accumulating Organisms (PAO). Nevertheless, the presence and proliferation of Glycogen Accumulating Organisms (GAO) that compete for substrate against PAO may be detrimental for EBPR systems leading to deterioration and, in extreme cases, failure of the process. Therefore, from both process evaluation and modeling perspectives, the estimation of PAO and GAO populations in activated sludge systems rises as a relevant issue. A simple method for the quantification of PAO and GAO population fractions in activated sludge systems is presented in this paper. In order to develop such a method the activity observed in anaerobic batch tests executed under different PAO-GAO ratios by mixing highly enriched PAO and GAO cultures was studied. Strong correlations between PAO-GAO population ratios and biomass activity were observed (R2 > 0.97). This served as a basis for the proposal of a simple, practical and seemingly reliable method to quantify the PAO and GAO populations in activated sludge systems based on commonly measured and reliable analytical parameters such as mixed liquor suspended solids (MLVSS), acetate (HAc) and orthophosphate (PO4 3−-P). The proposed method was evaluated using activated sludge from municipal wastewater treatment plants. The results from the quantification performed following the proposed method were compared to direct population estimations carried out with FISH analysis (determining Candidatus Accumulibacter Phosphatis as PAO and Candidatus Competibacter Phosphatis as GAO). Average differences in the determination of PAO and GAO fractions were around 4 and 1%, respectively. The method showed to be potentially suitable to estimate the PAO and GAO populations regarding the total PAO-GAO biomass. It could be used not only to evaluate the performance of Enhanced Biological Phosphorus Removal (EBPR) systems but also in the calibration of potential activated sludge mathematical models regarding the PAO-GAO coexistence.

Document Type: Research Article

DOI: https://doi.org/10.2175/193864707787977082

Publication date: 2007-01-01

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
X
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