New model for activated sludge flocculation integrating cellular biochemical reaction potential with the microbial ecology

Applicants are invited for a PhD fellowship/scholarship at Graduate School of Technical Sciences, Aarhus University, Denmark, within the Biological and Chemical Engineering programme. The position is based on a collaboration between Novonesis and Aarhus University and is available from 15 January 2027 or later. You can submit your application via the link under 'how to apply'.

Title
New model for activated sludge flocculation integrating cellular biochemical reaction potential with the microbial ecology

Research area and project description
While bacterial and activated sludge flocculation is the most important component of wastewater treatment processes, mechanisms governing flocculation are poorly understood. It is difficult to control and optimize activated sludge flocculation, and so downstream clarifiers for removing activated sludge from treated water are overdesigned or overloaded.

Effective flocculation is currently explained in terms of achieving the right balance between good and bad flocculating bacteria. Industrial wastewater treatment plants commonly experience poor flocculating sludges with impaired flocculation, which is attributed to too many bad flocculating bacteria. However, there is in fact a poor correlation between the microbial ecology of industrial wastewater treatment activated sludges and flocculation.
In this project the candidate will build on ongoing research in the host lab demonstrating that biochemical reactions occur within activation sludge that also likely promote flocculation The candidate will establish abiotic and biotic activated sludge models, assess the effect of flocculation stressors characteristic of industrial wastewaters, as well as biological, chemical and mechanical strategies for overcoming these. The research will inform strategies for the industrial to consider to increase the hydraulic of their wastewater treatment plant.

Qualifications and specific competences
Applicants to the PhD position must have a relevant master's degree in biology, biotechnology, biochemistry, biological or chemical engineering or a closely related field.

Place of employment and place of work
The place of employment is Aarhus University, and the place of work will be divided approximately evenly between Department of Biological and Chemical Engineering, Ole Worms Alle 3, 8000 Aarhus C., Denmark, and Novonesis, Hallas Alle 1, 4400 Kalundborg, Denmark.

Contacts
Applicants seeking further information regarding the PhD position are invited to contact:

• Associate Professor Thomas Seviour, e-mail: twseviour@bce.au.dk (main supervisor)
• Professor Barth Smets, e-mail: Bfsm@bce.au.dk (co-supervisor)

For information about application requirements and mandatory attachments, please see our application guide. If answers cannot be found there, please contact:

• admission.gradschool.tech@au.dk

How to apply
Please follow this link to submit your application.

Application deadline is 27 November 2026 23:59 CET.

Preferred starting date is 15 January 2027.

For technical reasons, you must upload a project description. Please copy the project description above and upload it as a PDF in the application.

Please note:

• Only documents received prior to the application deadline will be evaluated. Thus, documents sent after deadline will not be considered.
• The programme committee may request further information or invite the applicant to attend an interview.
• Shortlisting will be used, which means that the evaluation committee only will evaluate the most relevant applications.

Formalities and salary range
Salary and terms as agreed between the Danish Ministry of Taxation and the Confederation of Professional Unions. You will be employed as an academic staff member at basic salary grades 4–8. As a PhD fellow you will also receive a monthly non-pensionable allowance.

Aarhus University’s ambition is to be an attractive and inspiring workplace for all and to foster a culture in which each individual has opportunities to thrive, achieve and develop. We view equality and diversity as assets, and we welcome all applicants.

The application must be submitted via the online recruitment system, which can be accessed under ‘How to apply’.