Control measures for wastewater treatment plants during storm flow

In the context of the development of treatment plant control techniques, three measures for maintaining a high efficiency of treatment plants during rainfall events were tested. The three measures are increasing the nitrification volume by operating a facultative aeration, bypassing the primary sedimentation and adding flocculants before secondary sedimentation. Ammonia concentrations and ammonia loads were used in combination with rainfall forecasts as the criteria for putting the measures into operation. A simulation based on the Activated Sludge Model No. 1 and a pilot scale plant were used for testing the measures. The results show that all three measures may be suitable to cope with peak loads of treatment plants during rainfall events.