PhD defense : Activated sludge batch settling: from experimental investigation using an ultrasonic transducer to 1D modelling, sensitivity analysis and parameter identification

PhD defense : Florent LOCATELLI

Team : MécaFlu

Title : Activated sludge batch settling: from experimental investigation using an ultrasonic transducer to 1D modelling, sensitivity analysis and parameter identification

Abstract : In order to optimise the design and operation of activated sludge wastewater treatment plants, powerful tools, such as numerical models, are required. A thorough experimental investigation of the simulated phenomena is key to the development and improvement of these models. It is however delicate in the case of secondary clarifiers, where treated water and sludge particles are separated, and the process of model development is thus often impaired by a lack of precise enough data. During this Ph.D., an experimental setup combining a settling column and an ultrasonic transducer was designed. It was used to measure detailed settling velocity and concentration profiles, which allowed understanding the mechanisms of sedimentation and compression of activated sludge better. These results have been applied to the development of a numerical approach. A settling model using a well-known approach and completed with experimental functions was built. A methodology based on the automatic differentiation of the model was developed. It was used, on the one hand, to analyse the sensitivity of the results to the model parameters and, on the other hand, to identify the parameter values on the basis of experimental data. The combination of the proposed experimental and numerical methods yields an efficient process for the development of sedimentation models.

This thesis was supervised by Karim Bekkour (University of Strasbourg) and co-diriged by Julien Laurent (ENGEES).

The presentation will take place on Thursday 24th September 2015 at 2.00pm in room 419 of ENGEES (1 Quai Koch, Strasbourg) and will be held in English.