Using Whey as a Supplemental Carbon Source under Real Time Control Conditions …or a story of… Turds and Whey
Abstract:The COD:TKN ratio in the influent wastewater to the J.D Phillips Water Reclamation Facility (WRF) in Colorado Springs is too low to allow sufficient denitrification to meet the discharge limit for pH. To reduce the reliance on adding caustic to the effluent to raise the effluent pH, Colorado Springs Utility (CSU), began a search of local industries to find a source of local supplemental carbon to increase denitrification, and hence alkalinity recovery. Simultaneously, a local dairy approached CSU requesting relief from significant monthly excess BOD and TSS surcharges. The dairy manufactures cottage cheese, producing acid whey as a waste. A full scale pilot test was initiated at the WRF to investigate the opportunity to use whey as a supplemental carbon source to enhance denitrification. During this test, it was discovered that fermented whey provided superior results to unfermented whey.
The costs of implementing and operating advanced aeration control systems have to be justified by the reduction in energy consumption and/or improvements of the effluent quality. Control measures should also not introduce operational problems like foaming or bulking or higher green house gas emissions (mainly N2O). In addition to the effluent pH issues, as with all utilities, CSU is faced with reducing operating costs as much as possible. The effluent ammonia limit for the WRF varies on a monthly basis, which raised the question – “With the use of on-line analyzers, could the activated sludge process be operated to produce an effluent just below the permit limit to save aeration power?” A desktop analysis using BioWin™ and the BioWin™ Controller was performed to predict which of feed-forward or feed-back control would provide the best control. On-line ammonia and nitrate probes were installed at various locations and programmed into the aeration blower and mixed liquor recycle pump control systems to determine if aeration blower airflow and whey feed rates could be optimized. This paper will summarize the results achieved through the full scale pilot test, list future activities at the WRF and briefly discuss the outcome of the pretreatment permit negotiations with the dairy.
Document Type: Research Article
Publication date: 2010-01-01
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. 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