The Orlando Activated Sludge Process … To Aerate Or Not To Aerate

The City of Orlando's Water Conserv II Water Reclamation Facility is operating in a process control regime that was not intended by design. The facility was expanded in 1986, increasing permit capacity to 25 mgd, without any regulatory requirements for nitrate; however, in 1992, a nitrate limitation of 10 mg/l as a monthly average was included in the Florida DEP operating permit. Since that time, the City has successfully met all nitrate permit limits by altering the design mode of operation within the plug flow conventional activated sludge process. Even though the facility was not specifically designed to accomplish nitrification or denitrification, the operational protocol of the plug flow conventional activated sludge system has been modified to allow nitrification and denitrification to take place simultaneously within the same aeration zone.