Skip to main content

Understanding the hydraulic behavior of the anaerobic compartment of a BNR system using Computational Fluid Dynamics

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial

Abstract:

Flow characteristics of the anaerobic section of a biological phosphorus removal (BPR) pilot plant is investigated using Computational Fluid Dynamics (CFD) modeling tool. This includes the set-up and validation of an appropriate model and its application for detailed hydraulic analysis. The anaerobic tank investigated, consists of three compartments, identical in size and each equipped with an agitator. Validation of the CFD model is accomplished by: a) comparing experimentally measured Residence Time Distributions (RTD) to the CFD results and b) by using the CFD results to calculate the impeller dissipated power and comparing it to values found in literature. Hydraulic analysis illustrates good agreement between experimental and numerical RTD for various operational conditions. Comparing numerical with theoretical Hydraulic Residence Time (HRT = volume/flowrate) exhibits consistent results with regard to the whole anaerobic unit. Analysis of the separate compartments, however, reveals a high deviation of the Residence Time (RT) from one section to the other. A strong recirculation is found within the first compartment along with short-cuts in the following two sections at different conditions (flow and impeller speed) tested. Furthermore, analyzing velocity vectors and fluid particle trajectories, the performance of the second agitator is found to be insufficient to achieve the intended up-pumping effect and hence favors the “short cut behavior”.

Results of phosphate and COD (chemical oxygen demand) measurements during BPR operation reflect the impact of these hydraulics on the biological response.

The results of this study are used to point out the applicability of the model for detailed diagnostic and future design applications.

Document Type: Research Article

DOI: https://doi.org/10.2175/193864702784162633

Publication date: 2002-01-01

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 These proceedings are not peer reviewed.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