Comparison of Primary Clarifier Performance, Baffled Versus Conventional Feedwell at the Buffalo Sewer Authority

Primary clarifier performance effects the overall operation of wastewater treatment facilities. Removal of solids under highly variable flow and solids loadings is important. The Buffalo Sewer Authority's Bird Island Treatment Plant has four 48.8 m (160 ft) diameter primary clarifiers. The Authority identified a need to increase primary clarifier performance during high flow events and has installed a baffled inlet modification in one clarifier. The Flocculating Energy Dissipating Well Arrangement (FEDWA™) baffle influent well system is a series of open baffles which create multiple areas of flow impingement, each reducing kinetic energy and promoting staged, tapered flocculation. Extensive evaluation using CFD, performance monitoring, drogue tests, tracer tests and underflow solids profiles demonstrated improved performance at peak flow using the baffled inlet. The results have significant implications for communities that need to extend the hydraulic limitations of existing primary clarifiers.