AWWA WQTC58841

This study focuses on the settling step (solid-liquid gravity driven separation) in conventional drinking water treatment plants. To simulate settler performance, a numerical model is presented herein. The model takes into account the presence of the sludge by adding a 1D settling source term. The expression of the source term is fitted on a well-known test case, the single batch-settling test. An advection equation is solved by a finite difference method and validated experimentally. Moreover, the comparison between batch and numerical settling curves gives a sludge parameter estimation of the Takacs settling velocity model. The coupling of this model with CFD is implemented in the ESTET-ASTRID software. First results on an industrial application show the model efficiency. A lab-scale pilot dedicated to the validation of the CFD model is described and hydrodynamics results are presented. Includes 17 references, figures.