Modelling and simulation of final clarifiers in wastewater treatment plants Original Research Article

The complex dynamic process of clarification, settling and thickening in final clarifiers of wastewater treatment plants is very sensitive to changes in hydraulic and organic loading. Vitasovicʹs solid flux model and several modifications of the sludge settling velocity in this model are investigated and applied to the sewage plant of Siegen. The underflow and effluent suspended solids concentrations are used for comparison of simulation results. Hydraulic overloading during rainfall periods are modelled very well. However, the effluent suspended solids concentration during dry weather periods with changes in organic loading is not yet sufficiently modelled by all the proposed modifications of the sludge settling model.