How a Simple Bench-Scale Test Greatly Improved the Primary Treatment Performance of Fine Mesh Sieves
In Norway fine mesh sieves are frequently used for primary treatment or as the only treatment before wastewater is discharged to coastal waters. The reasons for this are the intensive product development of fine mesh sieves taking place in Norway, and the significantly reduced investment costs and space requirements compared to other primary treatment processes. Historically the design of these sieves was not very sophisticated. The goal of this R & D was to develop a fairly simple test procedure that can be used to characterize wastewater, establish design criteria for fine mesh sieves and predict removal efficiencies for full-scale plants under different operating conditions. The bench-scale test procedure was verified at several full-scale municipal wastewater treatment plants that used different types of fine mesh sieves (rotating belt, rotating disc, rotating drum, stationary), by comparing the bench-scale test results to the fullscale results. To achieve high removal efficiencies it was crucial to operate the sieves with a filter mat. Rotating belt sieves performed best in the full-scale tests. Properly operated the rotating belt sieves consistently removed more than 50 % SS and 20 % BOD5, as required by the European Union for primary treatment. Fine mesh sieves with pumped influent should have frequency controlled pumps to avoid on/off operation. At plants with several sieves in parallel, all sieves should be running even at low water flows. This will enable operation with thick filter mats and high removal efficiencies. Simple screw presses dewatered the sludge from the sieves to typically 25 – 30 % total solids. Using fine mesh sieves with < 500 microns openings was found to normally be the most economical process for primary treatment.
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: 2006-01-01
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 These proceedings are not peer reviewed.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