Saving on operational costs while improving effluent quality by optimising propeller and aerator configuration

The challenge

Waterschap De Dommel wanted to retrofit the aeration system of their large WWTP in Eindhoven (NL). What's more, they discovered increased oxygen levels near the inlet of the anoxic zone, which lead to higher effluent nitrate. Instead of a risky and costly trial-and-error process, the utility selected CFD modelling to find the best solution for their challenges. This enabled Waterschap De Dommel to make confident decisions in terms of optimizing their plant.

Questions the utility had:

• What's the optimal placement of the new aeration system to maximise effluent quality?
• Can we save on energy consumption?

Our approach

We simulated one of the three identical bioreactors of the 750,000 p.e. WWTP in 3D. By applying our proprietary multiphase WWTP CFD model with integrated biokinetics, we could accurately visualise oxygen and nutrient concentrations, besides flow patterns. During the project, we tested nine different scenarios to optimise plant operations in terms of performance and cost. We tested operational, design changes and hybrid combinations.  

How Waterschap De Dommel benefited

• Three mixers could be switched off at certain flow rates, leading to less effluent nitrate and reduced energy consumption, while velocities were still high enough to prevent settling.
• We discovered the optimal aerator configuration.
• The CFD model was proven to be very accurate.

Want to learn more?

Read our in-depth blog articles on this case or watch the video:

• Saving costs and improving effluent by knowing what is happening in your bioreactor - Part I
• Saving costs and improving effluent by knowing what is happening in your bioreactor - Part II

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