Parameter calibration in a model of the secondary settling tank in wastewater treatment

Abstract: In a wastewater treatment plant, particles (activated sludge) are separated from the liquid in a process called continuous sedimentation. This process is of crucial importance when purifying water in a wastewater treatment plant. This report will focus on a special case of sedimentation, namely batch sedimentation, which means that no flux into or out from the sedimentation tank are present. The goal is to implement and calibrate a mathematical model, that describes the phenomenon. During batch sedimentation, both in reality and in the model world, the conservation law implies solutions with shock waves. These shock waves set high standard for the numerical method used in the implementation. A specific model for this purpose is going to be used. Some interesting results were found about the induction period in the initial phase of the sedimentation. Further improvements were observed when dispersion was taken into account in the model. Nevertheless, there is no doubt about the fact that more research in this area is needed.