The City of Atlanta is currently expanding its water reclamation centers (WRCs) to meet a 0.75 mg/l effluent phosphorus limit. A high phosphate detergent ban resulted in a dramatic decrease in influent phosphorus of over 35%. A new pretreatment ordinance will also limit industrial discharge of phosphorus. The final plan involves building a tunnel to carry primary effluent from one WRC to another. All three WRCs will use biological phosphorus removal (BPR) with optional chemical addition. It is expected that a single permit with a mass limit for phosphorus will be issued to the three Atlanta WRCs. While the upgrades are under design, the existing plants have been operationally modified to achieve limited BPR with chemical addition. It has been determined that iron addition to the end of the anaerobic section of the BPR process yielded the most efficient use of chemical. This option has been incorporated in the plant designs.
Atlanta’s Phosphorus Removal Program Interim Biological – Chemical Removal of Phosphorus
Authors: Mark J. Tetreault, Tyler Richards, Phil Nungesser, Holly Elmendorf
1993 WEFTEC Technical Session