Topic background 

Biological activated carbon (BAC) filters are used throughout the world to treat water by removing organic contaminants, specifically small organic contaminants. The water becomes suitable for further use, ultimately as freshwater. Despite increasing use, because of their low cost and low environmental footprint, there are many scientific questions about how they work. For instance, will aeration or oxygen dosing boost the filter performance, or is the frequent removal of the biological material (biofilm) from the surface of the carbon particles helpful. Also, the properties of the carbon particles are important to understand. If we understand these aspects, we can further optimize the technology and operate it better, to clean water to an even higher degree at lower costs.

Research challenges 

To understand BAC filters better, we will set up a detailed description of the physical-chemical transport processes and the relevant biology and combine that into a complete mathematical framework. Existing knowledge from Wetsus and Wageningen is implemented in this code as well as knowledge from literature. In setting up this model, important choices are made about which phenomena are relevant and must be included, and which parts are less relevant. Important is a physical description of the functioning and growth of the bacterial phase (in the form of biofilm). The BAC column behaves like a reactor that operates dynamically, and this dynamic behavior will be studied and quantified by numerical modeling. The results of the model are compared with existing data from literature and the Wetsus laboratory.

Your assignment
You will build a comprehensive model of a BAC column filter’s dynamic operation, taking into account variables such as oxygen dosing and biofilm growth. The project involves creating models for mass transport, adsorption, and reaction, and solving simplified models using spreadsheet software such as Microsoft Excel. For more complex numerical programs, you will need to use Maple software.

The ultimate goal of this project is to gain a better understanding of the key processes involved in the operation of BAC columns. By doing so, you can make recommendations for improving the design and use of these filters. This project offers a great opportunity to develop your modeling and problem-solving skills in the field of water treatment.

Professor/University group/Wetsus supervisor(s): Prof. Dr. Ir. Bert van der Wal (Wageningen University), Dr.Ir. Jouke Dykstra (Wageningen University), Dr. Amanda Larasati (Wetsus), Dr. Maarten Biesheuvel (Wetsus)

Project partners: Advanced Water Treatment theme

We are looking for a student having an MSc degree in chemical engineering, or a related education that combines aspects of chemistry and physics. You have a strong interest in theoretical modelling of mass transport, adsorption, and chemical reactions by methods from the field of chemical reactor design (not molecular dynamics, density functional theory, computational fluid dynamics, etc.). You like to read scientific literature critically, and you like to think deeply about a technological process to find out what are the key mechanisms. You can communicate your research results in personal discussions, and by writing reports and scientific papers.

Keywords: contaminant removal, process modelling, combined biological-physical system, multicomponent reaction, and transport process.

Salary and working conditions are according to the collective labour agreement of the Cooperative Association of Dutch Universities (VSNU) for PhD students.

Wetsus, European centre of excellence for sustainable water technology is a facilitating intermediary for trendsetting know-how development. Wetsus creates a unique environment and strategic cooperation for development of profitable and sustainable state of the art water treatment technology.

The inspiring and multidisciplinary collaboration between companies and research institutes from all over Europe in Wetsus results in innovations that contribute significantly to the solution of the global water problems. Wetsus’ scientific research program is defined by the private and public water sector.

Read more about our current PhD program. All info about the research at Wetsus can be found here.