CONTROLLING NITROGEN REMOVAL USING REDOX AND AMMONIUM SENSORS
Redox sensors have been in use at the wastewater treatment plants in Odense, Denmark since 1990 Starting in April 2000 at the Northeast WWTP the signals from ammonium and redox sensors have been employed for the automatic control of the nitrogen removal process. This resulted in a reduction of the effluent total nitrogen concentration from 5.9 mg/L to 4.2 mg/L. At the same time there was a small increase in carbon source consumption and a fairly large increase in power consumption for aeration. The increased power consumption may be related to an increase in the load on the activated sludge unit but this not likely. The problem has to be investigated further.