City of Attalla

Alabama – The municipality was looking for a solution to reduce the overall Total Phosphorus (TP) as well to handle the summer algae blooms in their lagoon. After running a successful pilot trial with a FRC DAF, the solution was clear. FRC was chosen to design a full-scale DAF system based on the pilot trial.

The overall objective was TP removal. The engineer chose to leave the lagoon intact and reduce TP with DAF instead of converting to a full mechanical, high-rate wastewater treatment system, saving the city millions of dollars.

Algae and TP removal is straightforward using a FRC DAF, effectively reducing TP well below 1 mg/l. An added benefit for using DAF in this scenario is reducing the algae and Total Suspended Solids (TSS) while also protecting the downstream Ultra-Violet (UV) system. The small footprint of the two parallel DAF units allowed for a reduced building size, saving on overall construction costs.

Design Data

FRC Solution

  • Flocculator – Chemicals are dosed to precipitate the algae and phosphorous
  • DAF – Floats and separates the precipitated solids yielding effluent that is directly discharged to the UV system

Talk to an FRC engineer about your application.