Skip to main content

Recycling Nitrates to Headworks for Multiple Benefits in a Fixed Film Plant

The full text article is not available for purchase.

The publisher only permits individual articles to be downloaded by subscribers.

or click here to sign up for a free trial


This paper describes the results obtained at the Littleton/Englewood wastewater treatment plant using an intra-plant nitrified effluent recycle (NER). A NER capacity equal to 50-percent the design maximum month flow was implemented. By pacing the NER flow the plant can be essentially base-loaded thereby attenuating influent diurnal peaks and providing overall plant stability. The removal of nitrates in the headworks, recycled back via the NER was approximately 35-percent the mass returned. During the period studied the mass of nitrate removed through the headworks averaged about 580 lb/d as nitrogen. The corresponding mass of total inorganic nitrogen removed through the trickling filters averaged 1,230 lb/d. On average a total of 1,900 lb/d of nitrogen was removed upstream of the “official” nitrogen removal processes. For an example removal of 1,500 lb/d nitrogen, the annual cost of the NER system would be one-third the cost of the denitrification filter system using methanol. Implementation of the NER system significantly reduced odors and H2S levels measured at the primary clarifiers, thereby saving on odor control chemicals. By incorporating the intra-plant recycle, redundant and costly denitrification filter units were avoided.

Keywords: Nitrification; denitrification; denitrification filters; intra-plant recycle; odor control; trickling filters

Document Type: Research Article


Publication date: January 1, 2011

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 These proceedings are not peer reviewed.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Ingenta Connect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
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