Improving effluent quality in an oxidation ditch
Quantifying inhomogeneous mixing
An oxidation ditch was modelled in 3D using multiphase CFD combined with biokinetics (CFD-biokinetic model). The operational performance was evaluated at different conditions in terms of oxygen transfer and ammonium removal.
- High vertical and horizontal gradients of oxygen and nutrients were found
- Ammonium concentrations accumulated at the bottom due to lower dissolved oxygen levels (brush aerators in this case)
- Performance of the oxidation ditch could be improved by modifying the aerators