Skip to main content

The Impact of Degree of Recycle on the Nitrifier Growth Rate

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial

Abstract:

The nitrifier maximum specific growth rate μA,max, is a critical parameter for design and performance of nitrifying activated sludge systems. Although many investigations have been devoted to study μA,max, only a few have dealt with the effect of the reactor configuration on this important kinetic parameter. Bench-scale and full-scale trials were devised to study the impact of the internal mixed liquor recycle (IMLR) on the nitrifier growth rate constant. The nitrifier growth rate constant for an existing activated sludge plant was determined at different operational conditions using the High F/M test and by process model calibration. Overall, the results obtained during this study indicate that high IMLR values have a negative effect on μA,max. Based on the results obtained during this investigation, a 15-percent decrease in μA,max was observed at IMLR of 4Q or higher. It is surmised that at high IMLRs, the reactor behavior shifts from a plug-flow configuration to a “ quasi” complete mixed configuration influencing either the species selection in activated sludge population or at least adaptation of specific species. These results have a tremendous impact on the design of activated sludge processes that incorporate IMLR for denitrification such as the Bardenpho, MLE, UCT and A2/O.

Keywords: biological nutrient removal; high F/M method; kinetics; nitrification; nitrifier growth rate

Document Type: Research Article

DOI: https://doi.org/10.2175/193864709802770045

Publication date: 2009-01-01

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 These proceedings are not peer reviewed.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