Eawag, the Swiss Federal Institute of Aquatic Science and Technology, is an internationally networked aquatic research institute within the ETH Domain (Swiss Federal Institutes of Technology). Eawag conducts research, education and expert consulting to achieve the dual goals of meeting direct human needs for water and maintaining the function and integrity of aquatic ecosystems.

The Department of Process Engineering (ENG) has a vacancy for a

The Right Mix: optimizing densified activated sludge (DAS) composition for improved settling and nutrient removal

Many municipal wastewater treatment plants (WWTPs) around the world are approaching their maximum capacities, while the space is limited for plant expansion or new facilities. With increasingly stringent legislative requirements, there is a crucial need of intensified biological process for existing and future WWTPs. Densified Activated Sludge (DAS), a mixture of flocs and small, dense granules (average diameter ca. 200~500 µm), offers significant advantages over conventional activated sludge, such as higher biomass retention and improved settleability. DAS can help break the endless loop of seasonal sludge bulking and provides greater flexibility in tuning aeration strategies for enhanced nutrient removal. However, fundamental knowledge gaps remain regarding the optimal composition (i.e., fractions of flocs and granules) for both effective sedimentation and nutrient removal processes like nitrification and denitrification.

This project aims to bridge these gaps by investigating: a) the settling mechanisms of DAS and the impact of DAS composition on settling properties; b) the impact of DAS composition on microbial community structure and nutrient removal performance. Depending on interest, you can work with one or both of the aspects. You will have a unique opportunity to work closely with multiple Swiss WWTPs, developing both scientific and practical insights.

We are looking for a motivated master student or intern (enrolled in a university for the entire duration) with interests in advanced technologies for biological wastewater treatment. Fluent spoken and written English are essential. Skills in data analysis or programming is appreciated. Knowledge of German and/or having a valid driver’s license would be very beneficial. The preferred starting date is as soon as possible.

Eawag is a modern employer and offers an excellent working environment where staff can contribute their strengths, experience, and ways of thinking. We promote gender equality and are committed to staff diversity and inclusion. The compatibility of career and family is of central importance to us. For more information about Eawag and our work conditions please consult www.eawag.ch and www.eawag.ch/en/aboutus/working/employment.

Applications must be submitted until the position is filled and will therefore be evaluated on a rolling basis. Applications should include a short letter describing your interests and their relevance to this position, a CV and list of lectures/grades.


We look forward to receiving your application. Please send it through this webpage, as any other way of applying will not be considered. A click on the button below will take you directly to the application form.