Simulation of entire Waste Water Treatment Plants

What are the benefits of hydrograv simulations?

• Virtual pre-launching of the entire WWTP already in the planning phase
• Analysis of hydraulic interactions between individual treatment steps
• Proof of various operating scenarios

Example: Support in the planning of the WWTP Emschermündung – one of the largest plants in Germany

(Qmax = 16,5 m³/s, 1.6 million PE)

• Simulation of serveral treatment steps as part of the planning for reconstruction and optimisation of the entire WWTP:
  • Pumping station
    
    • comparison of variants of different inflow designs to the screw pump station, investigation of different operating modes
  • Bar screen
    
    • functionial demonstration, especially the hydraulic distribution and deposition
  • Grit chamber
    
    • comparison of different variants, e.g. 6 or 8 lines in operation, optimization of the geometry and the operation mode, maximization of the separation rate
  • Primary clarifier
    
    • comparison of different variants, e.g. circular or rectangular design, test of grease separation
  • Secondary clarifier
    
    • extensive comparison of variants: test of different scraper systems, sludge hopper design, inlet design, number of required tanks, proofs of revision states and construction phase
  • Distribution channels and structures
    • Ensuring uniform hydraulic distribution, avoidance of depositions, e.g. by hydraulic correct installing agitators or aeration, uniform distribution of the distribution of MLSS, verification of hydraulic losses

Figure:   Entire model constisting of bar screen, grit chamber and primary clarification. Water level at maximum inflow.

Figure:   Entire model consisting of bar screen, grit chamber and primary clarification. Streamlines with velocities at maximum inflow

Figure:   Pumping station incl. bar screens. Exemplary comparison of variants. Flow velocities along the water level at stormwater inflow. Six out of eight pumps in operation.

Figure:   Primary clarification. Exemplary comparison of variants. Streamlines with velocities.

Figure:   Grit chamber. Exemplary illustration of a variant. Streamlines with velocities.

Figure:   Grit chamber. Separation rate of different classes of materials for different variants.

Figure:   Inlet channel to activated sludge tank, exemplary analysis of a variant. Concentrations close to the bottom normalized with the mean basin concentration (left). Flow velocities close to the bottom (right). Note: For better legibility the basin width is shown stretched 4 times.

Figure:   Inlet channel to the aeration tanks, exemplary distribution of the inflow concentration.

Figure:   Inflow channel secondary clarification, exemplary evaluation of an investigated variant. Standardized sludge concentration 5 cm above the basin bottom. Above dry weather, below rainy weather.

Figure:   Secondary clarification, exemplary analysis of a variant showing the sludge concentration at maximum inflow.
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