Skip to main content

Beneficial Use of Dairy Wastes in POTWs

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

Publicly Owned Treatment Works (POTWs) are increasingly facing more restrictive effluent nutrient limits as Total Maximum Daily Loads (TMDLs) are being applied to receiving waters that are impaired due to the presence of excessive nutrients. This is causing an increasing number of POTWs to upgrade to provide total nitrogen control (denitrification and nitrification) and total phosphorus control. The cost of iron addition and subsequent excess sludge handling and disposal are causing more POTWs to upgrade to biological phosphorus removal. The readily biodegradable chemical oxygen demand (CODrb) naturally present in domestic sewage is inadequate for the denitrification and total phosphorus removal needs of these facilities. Historically, these facilities have added methanol as their additional source of CODrb. The cost of methanol had increased 380 percent through the 5 year period ending in January 2007. Additionally, the safety and security risks of handling methanol have posed concerns. These concerns have caused many of these facilities to turn to 56 percent by weight acetic acid as the current low cost source of CODrb. The cost of this material has increased by 35 percent during this same 5-year period. In either case, the cost of this type of supplemental CODrb is only expected to increase for POTWs making the operating costs of denitrification and biological phosphorus removal only increase with time while continuing to be influenced by market conditions. In addition, POTWs are facing rising energy costs (greater than 26 percent increase over the last 5 years). This has caused an increasing number of POTWs to implement energy recovery with anaerobic digestion facilities. This practice will only expand as energy costs continue to increase. Within 200 miles of nearly all POTWs, there are fluid milk plants that supply our nation's steady demand. These plants dispose of a small quantity of benign wastes generated from return products and off-spec products (approximately 0.5 percent of production). This concentrated waste has historically been transported at the industry's expense and utilized as animal feed or applied to agricultural lands. As more and more livestock operations consolidate and the distances to suitable agricultural lands increase, the disposal costs will continue to increase. These concentrated wastes offer a source of CODrb. There is a "win-win" solution for POTWs and the dairy industry with a combined savings projected at $15 million per year. One needs a low cost source of CODrb; the other provides this source and needs a low cost disposal option. This paper presents greater details of this synergy and concludes with case histories of those who have benefited from implementing this solution.
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: 2007-10-01

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
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