Skip to main content

MICROBIAL SUCCESSION IN ACTIVATED SLUDGE: ECOLOGICAL PRINCIPLES LINK COMMUNITY DIVERSITY AND OPERATING PERFORMANCE

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial

Abstract:

Heterotrophic biomass in activated sludge wastewater treatment systems often is described according to the kinetics of substrate utilization. Typically, two “groups” of microorganisms are described, namely floc-formers and filaments. Previous studies have attempted to correlate bioreactor operation with the relative abundance of these two “groups” of microorganisms. For example, plug flow bioreactors with high substrate concentrations have been shown to favor floc-formers (e.g., Monod-type r-strategists) while completely mixed bioreactors with low substrate concentrations have been shown to favor filaments (e.g., Monod-type K-strategists). The objective of this study was to determine if additional factors impact the diversity of the microbial community in activated sludge bioreactors. To meet this objective, we have begun to systematically explore correlations between the relative abundance of representative model microorganisms and bioreactor operating strategies. For these studies, fluorescence in situ hybridizations with 16S rRNA-targeted oligonucleotide probes have been used to identify and enumerate Acinetobacter spp. in samples from laboratory-scale activated sludge wastewater treatment systems. Preliminary results suggest that long idle stages, as would be expected in secondary clarifiers operated with significant sludge blankets, correlate with an elevated relative abundance of Acinetobacter spp. This elevated relative abundance appears to be independent of the initial concentration of growth limiting substrate in the bioreactors (i.e., long idle stages result in selective enrichment of Acinetobacter spp. in both plug flow and completely mixed bioreactors). Based upon these results, we hypothesize that the inclusion of long idle stages in bioreactor operation provides a selective pressure that dictates the composition of the microbial community independent of the initial concentration of growth limiting substrate. These results have broad implications for biological wastewater treatment – suggesting that the current two “groups” of heterotrophic microorganisms may be insufficient to capture the essential diversity of microorganisms in activated sludge bioreactors.

Document Type: Research Article

DOI: https://doi.org/10.2175/193864701790902482

Publication date: 2001-01-01

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