Skip to main content

UNIFIED COMPUTATIONAL MODEL FOR ACTIVATED SLUDGE, IFAS AND MBBR SYSTEMS

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

Research was undertaken to measure kinetic parameters for an Unified computational model that can be applied to activated sludge, IFAS and MBBR systems. The model is for COD removal, nitrification and denitrification. There are significant advantages of such a model: 1) it eliminates the need to run separate computational models for each of the three systems; and (2) a single model can be used to evaluate all three configurations for plant design and retrofit.

Pilot scale continuous flow units were operated in the UCT/VIP configuration to measure the kinetic parameters for the model. The IFAS and MBBR systems (units) were operated in parallel with an activated sludge system. The systems were operated under identical wastewater loads, tank and nitrate recycle configuration, except for the biofilm support media in the aerobic zone of the IFAS and MBBR systems. The flow rate was 208 L/day and the nominal HRT was 12 hours. The operating temperature of 12 C was low enough to stress the nitrifiers in the mixed liquor suspended solids as the mixed liquor MCRT was lowered. Specific phases of the study included:

Activated sludge system operated at aerobic zone mixed liquor MCRTs of 3.1 days, 2.4 days, 1.7 days and 1.0 days;


Integrated Fixed Film Activated Sludge (IFAS) system operated with biofilm support media in the aerobic zone. The IFAS unit was operated in parallel and at the same mixed liquor MCRTs as the activated sludge system;


Moving Bed Biofilm Reactor (MBBR) system operated without return activated sludge (RAS) recycle with biofilm support media in the aerobic zone. The MBBR unit was operated in parallel to a control system without biofilm media and RAS.


The aerobic zone of each of the three systems was divided into three cells with equal volume to determine how the biofilm would develop, and COD uptake and nitrification rates would vary with the soluble biodegradable COD and ammonium-N along the aerobic zone.

The most important equations identified as part of this research effort are the rates of COD removal and nitrification per unit surface area of biofilm, and their dependence on the soluble biodegradable COD and ammonium-N concentrations. The structure of these equations is similar to the Monod equations used for removal (uptake and oxidation) of COD and ammonium-N in the mixed liquor suspended solids. By adding the removal rates of COD and ammonium-N in the biofilm to that in the mixed liquor suspended solids, the model is able to compute the total removal in each reactor.

The COD removal, ammonium-N removal and nitrification and denitrification, the concentration profiles and the effluent values computed by the model compared satisfactorily to the concentrations measured in the pilot unit. Additionally, the model was able to determine the amount of biofilm surface area that would be required and the best locations for the media to maximize the increase in nitrification. Based on this, the user is able to compute how much media will be required to retrofit a plant that is not nitrifying or is partially nitrifying.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Data/Media
No Metrics

Document Type: Research Article

Publication date: 2005-01-01

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