A Case for Low Return Sludge Flow Rates
Abstract:A common problem encountered by traditional activated sludge systems involves failure to develop biomass that separates efficiently from the liquid, leaving behind a clear effluent that is low in BOD5 and suspended solids. Another problem is the bleed-through of ammonia due to low detention time in the aeration tank. Oftentimes, failure may be attributed to high return sludge flow rates (RSF) that affect not only clarifier hydraulics, but also the growth of bacteria in the system. In order to promote efficient separation and nitrification, system conditions should be maintained that favor the growth of flocforming bacteria and nitrifiers over nuisance microorganisms that may include filaments. Favorable conditions are encouraged by a regime of higher detention time and feast and famine experienced by the bacteria in the system. By viewing system operation through this lens, the following paper proposes that many activated sludge treatment systems can achieve significant operational improvement through reduction in RSF. This paper further provides a method for minimizing RSF and presents examples of successful application of this method
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 These proceedings are not peer reviewed. 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