Sedimentation challenges motivated a scientific stay in Concepción by Colombian mathematicians

Sedimentation challenges motivated a scientific stay in Concepción by Colombian mathematicians
  • They spent three months collaborating with Prof. Raimund Bürger, researcher at the Mathematical Modeling Center of the University of Chile and deputy director of CI²MA at UdeC.

A few weeks ago, Estefanía Guevara Blanquicett and Daniel Támara López completed their research stay at the facilities of the Center for Research in Mathematical Engineering (CI²MA) of the Universidad de Concepción. The graduate students from the National University (UNAL) of Colombia, were collaborating with the principal investigator of the Center for Mathematical Modeling (CMM) of the U. of Chile and deputy director of CI²MA Dr. Raimund Bürger.

Both are working on their theses for the PhD program in Mathematical Sciences at UNAL, under the direction of Dr. Carlos Acosta Medina, researcher of the Scientific Calculus and Mathematical Modeling research group and academic of the Department of Mathematics and Statistics of the Faculty of Exact and Natural Sciences of UNAL.

Both Daniel and Estefania are in the last stage of their doctoral studies and, in particular, she explained that her area of research is the “numerical analysis of partial differential equations and inverse problems”, a line in which she has been working since her master’s studies. She also mentioned that “the initiative to work in the field of wastewater treatment (in Colombia wastewater) arises, on the one hand, from the guidance of my thesis director who has been conducting studies related to the subject and, on the other hand, from the need that exists at the local level (Manizales, Colombia) to develop research on the management and treatment of wastewater”.

Guevara detailed that the objectives “have to do with the advances of my thesis, however, we still do not touch the inverse problems, but we are dedicated to understand and numerically solve a direct problem on sequenced batch reactors (SBR) with oxygen supply”. He also noted that “the next step in my work is to add aeration control to the model and develop numerical simulations”.

Estefanía Guevara’s stay at CI²MA is funded by the CMM, through the Doctoral Visitor Program 2023, especially for her travel and living expenses, which she complemented with the support she received through the National Call for the Support of International Mobility of the UNAL 2022-2024.

In the case of Daniel Támara, he had the support of the Faculty of Exact and Natural Sciences of the UNAL, Manizales branch, for the purchase of his air tickets. “Our research topic is one that Prof. Bürger has been working on for a long time (modeling and numerical solution of the sedimentation process) and, in fact, the idea of doing this internship arose from a meeting between Prof. Bürger and my thesis director, Carlos Daniel Acosta Medina, with whom I have worked since my master’s studies,” he said.

Although both Daniel’s and Estefania’s thesis are related to the sedimentation process in wastewater treatment, he explained that “each one has a specific problem to study. In my case, I am researching on the numerical solution of reactive sedimentation models in secondary sedimentation tanks (SST) with variable cross-sectional area”. He also explained that “such models are governed by partial differential equations of convection, diffusion and reaction. The idea is to be able to analyze the evolution in space and time of the concentrations of certain particles under the influence of chemical reactions.”

“So the main topic of my thesis is precisely the development of efficient numerical methods for reactive sedimentation models and, during the internship, we have made progress in this direction. We have managed to adapt an existing model to one that describes the solid phase from percentages and considers a TSS with variable cross-sectional area. In addition, we have an explicit method ready that considers the aforementioned novelties, and the idea is to compare it now with a semi-implicit one, on which we are currently working”, said Támara.

Prof. Raimund Bürger said that “it has been a very pleasant experience to have them visit us. Both of them have worked very hard and have made significant progress on the issues raised. In the meantime, we have already continued to contact each other and I trust that the stay will also lead to publishable research work (…) They have the doors open for future visits or stays at CI²MA. I would like to take this opportunity to thank the CMM for managing the funding through the BASAL FB210005 project”.

By Iván R. Tobar Bocaz, CMM journalist.

Posted on Jan 31, 2024 in News