Replacement of the aerators at the Au wastewater treatment plant
The best aerators and blowers and the best control tools are useless if the control system is not set correctly. At the Au wastewater treatment plant of the Hamm/Sieg municipality, the aeration technology with the blowers and the EMSR was completely replaced in 2024. Since then, the aeration has been running with the controller's initial settings. After the plant manager, Mr Rabbich, informed us that he was not satisfied with the nitrogen elimination, we looked at the controller settings and made adjustments.
Adjustment of the control parameters
The adjustment of the control parameters means that the aerated and non-aerated phases are now much more clearly delineated. The oxygen setpoint is reached more quickly in the aerated phase. This shortens the aerated phase and leaves more time for denitrification. As a result, both nitrification and denitrification are improved.
At the same time, you can see that the ventilation times are shorter, so the energy consumption of the fans is also reduced.
Regular checks
The control behaviour in the biological stage should be checked regularly. Adjusting the control parameters may take a few hours of work. The change in the settings must be observed and evaluated again and again over a period of several weeks. However, no installation or programming is required. The energy savings and the improvement in the discharge values result in a high added value of such a measure in a short time.
Norbert Meyer, June 2025
