New legislation from EU call for removal of micropollutants such as pharmaceuticals from wastewater. Stockholm Vatten och Avfall (SVOA), a municipal water utility in Stockholm, is currently rebuilding Henriksdal wastewater treatment plant (WWTP) to a process based on membrane bioreactor (MBR) to treat water from 1.6 million people equivalents. But to meet the new requirements, Henriksdal WWTP will have to implement additional treatment for micropollutant removal.
The most commonly used alternatives for micropollutant removal are either ozone or activated carbon or a combination of the two. Where ozonation typically requires a high energy usage and is liked with at risk of forming toxic biproducts or transformation products, activated carbon is associated with a high carbon footprint. This poses a challenge in meeting other goals of sustainability while implementing quaternary treatment. Another callenge is that Henriksdal WWTP is located underground inside a rock, where available space is limited. This means that a compact and optimized solution for micropollutant removal is sought.
To test and challenge conventional design parameter for ozone and granulated activated carbon filters (GAC-filters) a pilot with four parallel treatment lines is operated at Henriksdal since March 2026. The startup and initial tests were evaluated in a previous master thesis (Lilja, 2026) and the pilot will continue in operation for at least another year.
The aim of the Master Thesis project is to investigate optimisation of ozone and GAC in the pilot plant. In the proposed project, different ozone doses will be tested and potential effects on toxicity will be investigated. Depending on treatment results optimisation of pilot operation might include changes in ozone dose, retention time or backwash strategy for the filters. The project could also include sensor evaluation for online monitoring and control. The exact trials in the pilot project will be decided based on the outcome of the literature study, already existing ideas, and depending on what is practically possible to test in the pilot.
This Master Thesis project is experimentally oriented and will involve operating a pilot plant, performing chemical analyses, running batch trials, possibly installing and calibrating sensors, and evaluating online data.
To be eligible for this thesis project, you should be enrolled in a program within chemistry, environmental engineering, water engineering, or another relevant field of study.
Most of the work will be performed at Henriksdals reningsverk (Värmdövägen 23, Stockholm). Daily attendance is required.
Industrial supervisor: Sofia Lovisa Andersson, sofia.lovisa.andersson@svoa.se (SVOA). Practical help: Gabriel Persson (SVOA).
This specific project is intended solely for students planning to conduct their thesis during the spring term 2027. However, if you are interested in doing a thesis project with us during the autumn semester of 2027, there may be opportunities closer to that time.
The applicants are invited to send a motivation letter, a CV, and a transcript of records from education on university level (in Swedish or English). The last day to apply is 30th of Nov 2026. Candidate selection is done continuously. In line with SVOA policy, a successfully completed Master's project is rewarded with a compensation of 30 000 SEK (pre-tax).
We are Swedens largest water and waste company. We have the environments, as well as both present and future Stockholmers, best interest at heart in everything we do. With us, you get to work with vital societal functions, and for a sustainable environment.
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