Optimisation of Total Emissions

Cross Field Optimisation of Loads

The progressive process in respect to optimisation of wastewater treatment plants leads to the fact that emissions of materials and organic substances in dry weather are becoming smaller. The focus of optimisation is now on heavy rain events, since in these cases mixing wastewater from (emergency) overflows of combined sewer systems is becoming a hydraulic and polluting burden.

In overall, they represent the largest source of emissions. For this reason, it makes sense to reduce the rainwater amounts in the sewer network. A stormwater source control helps also to reduce the inflow towards the treatment plant.

Experience has shown that municipal wastewater treatment plants can be stressed by combined wastewater during a precipitation event significantly higher than in the ATV-A 128 thresholds. Through the aid of dynamic simulations, it is possible to determine the unused plant capacity and the measures that need to be initiated for its use.  It is thus possible to reduce the volumes and loads, without overloading the sewage treatment plant. Through this holistic approach a significant optimisation of the complex sewage system is achieved, whereby the consequences of heavy precipitation are significantly reduced.

Below are exemplary results following a total emission optimisation of a combined sewer treatment system.

2QS - 2x dry weather wastewater flow + extraneous water
4QS - 4x dry weather wastewater flow + extraneous water
oO - no optimization
mO - with optimization (anticipatory adaptation of aeration in the water treatment plant)