Please use this identifier to cite or link to this item: http://repositorio.udec.cl/jspui/handle/11594/3545
Title: Una contribución a las simulaciones numéricas de tanques de sedimentación y aplicaciones relacionadas
Other Titles: A contribution to the numerical simulation of settling tanks and related applications
Authors: Bürger, Raimund , supervisor de grado
Mejías Neira, Camilo Ignacio
Keywords: Ecuaciones Diferenciales Parciales
Variables (Matemáticas)
Reutilización del Agua - Modelos Matemáticos - Modelos Matemáticos
Sedimentación - Modelos Matemáticos
Aguas Servidas - Purificación - Modelos Matemáticos
Issue Date: 2019
Publisher: Universidad de Concepción. Facultad de Ciencias Físicas y Matemáticas .Departamento de Ingeniería Matemática
Abstract: This dissertation deals with diverse mathematical and numerical aspects with new models and methods that try explain industrial processes about wastewater treatment, with focus in activated sludge settling, this processes are commonly treat with physical models excluding reactive part of the problem. At the rst part, we introduce a new time-discretization method that enable a more e cient simulation and it is compared with other methods. Di erent methods of discretization are presented, and are applied to two batch sedimentation cases: Kynch test and Diehl test above clear liquid. Performance is measured regarding the numerical error and the computational time. The proposed method is found to be easier to implement but slightly less e cient in terms of computational time. Next, we introduce a new model of batch sedimentation coupled with a simpli ed model of kinetic reaction concerning denitri cation. This is an important practical problem due to the possibility of secondary denitri cation causing ocs of activated sludge to rise to the top of the settler due to nitrogen gas bubbles forming in the ocs. We present a model that takes into consideration both hindered settling and compression behavior and also the reaction terms describing growth and decay of biomass, we aboard the governing equations, spatial and time discretization, numerical method and theoretical results and showed an examples using Kynch and Diehl test even at \overcompressed" case. Additionally, we present a new model of secondary settling tank. The model incorporate both uids ows and gravitational settling with compression behaviour and also enables the incorporation of kinetic of biological reactions to be included in the model. The model is based on conservation laws and the solid and uids phase velocities are replaced by a mixture velocity expressed by the given volumetric ows and model variables, and a solid- uid relative velocity, prescribed by a constitutive functions. Explicit expression for the total uxes of solid and liquid phases are derived. Constitutive functions for hindered and compressive settling are presented and the choice of initial data and feed input functions for a reactive denitri cation model are discussed. Numerical scheme is derived and a number of simulation results are presented for a reaction model with nitri cation. Moreover, corresponding error and convergence rates are presented. For all the situations described above, several numerical experiments illustrating the correct performance of the methods, and con rming the theoretical results, are reported. Finally, we propose di erent ways for make a future work in order to apply mathematical models and numerical schemes as a solution to the industrial processes, for example, build a package with this results and others, into a comercial software.
Description: Doctor en Ciencias Aplicadas con mención en Ingeniería Matemática Universidad de Concepción 2019
URI: http://repositorio.udec.cl/jspui/handle/11594/3545
Appears in Collections:Ingeniería Matemática - Tesis Doctorado

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