Solving the City of Tacoma's High Effluent TSS Problem: Unexpected Causes of Deflocculation
The Central Treatment Plant for the City of Tacoma has had problems with elevated effluent TSS concentrations and turbidity during periods of low flow. After eliminating other possibilities, it was determined that ammonia return in the filtrate from the belt filter presses was the likely cause of deflocculation, as concentrations in the mixed liquor were found to increase from 20 mg/L-N to 90 mg/L-N during the day. Given that ammonia acts as a monovalent cation, it is likely that the high filtrate ammonia concentrations affected the ionic composition of the mixed liquor, increasing the monovalent to divalent cation ratio and leading to deflocculation and high effluent TSS concentrations. In order to test this, bench-scale protocols were developed. Results of continuous flow and batch experiments clearly showed that the filtrate caused an increase in effluent turbidity and TSS concentrations. Several modifications to the operation of the dewatering system at the Central Treatment Plant were recommended to reduce the impact of filtrate on the mixed liquor.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: 2008-01-01
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 These proceedings are not peer reviewed.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