Thesis project proposal autumn term: PFAS removal from municipal wastewater by foam fractionation

Om arbetsplatsen

Removal of per- and polyfluoroalkyl substances (PFAS) from municipal wastewater has previously not been required, since the concentrations are low and treatment with existing methods are extremely costly. The regulatory limits on PFAS concentrations in drinking water, environmental quality standards in surface waters, and guideline values for sewage sludge are being revised, which can motivate the need for increase PFAS removal from municipal wastewater. Therefore, there is a need for developing new technologies for cost-efficient PFAS removal, preferably introduced early in the treatment train in order to limit PFAS sorption to sludge.

One of the promising methods for PFAS removal, which was extensively studied and applied in full scale for leachate treatment is foam-fractionation (We et al. 2024). The method is based on removing foam that is formed during aeration of water. A recent study investigated PFAS removal by foam fractionation applied at different stages of conventional wastewater treatment (Malovanyy et al. 2025). The proposed Thesis project is to expand on this study.

Arbetsuppgifter

In the proposed project a number of experiments will be performed to investigate and further investigate influence of different parameters on the process efficiency. Foam fractionation experiments will be conducted using mechanically treated municipal wastewater (before primary sedimentation) and digested sludge as feed. Applying foam fractionation early in treatment line potentially allow for removal of PFAS both from water and sludge. The influence of treatment time, volume of concentrate, aeration rate, and air bubble size will be investigated in a number of experiments. For digested sludge a lower number of experiments will be performed in order to study the viability of foam fractionation for lowering PFAS content in sludge applied in agriculture.

This Thesis project is experimentally oriented and big part of the work will include running experiments and sending samples for analysis. Evaluation of results is also a part of the study. The theoretic evaluation of the result and comparison with other study will be included to a lesser or a large degree depending on the length of the Thesis project (15 hp or 30 hp).

Kvalifikationer

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 SWIC (Lindarängsvägen 99, Stockholm) and Käppala WWTP (Södra Kungsvägen 315, Lidingö). Daily attendance is required. Industrial supervisor: Andriy Malovanyy (SVOA). Practical help: Gabriel Persson (SVOA) and Erika Forsén (Käppalaförbundet).

If you are interested in doing a thesis project with us during the spring semester of 2026, there may be opportunities closer to that time. However, this specific project is intended solely for students planning to conduct their thesis during the autumn term.

Övrigt

The applicants are invited to send a short motivation letter (do not use AI !), a CV, and a transcript of records from education on university level. The application can be done in English or Swedish. The last day to apply is 30th of Aug 2025. Candidate selection is done continuously and can be finalized before this date. In line with SVOA policy, a successfully completed Master's project is rewarded with a compensation of 1 000 SEK (pre-tax) for every hp of the project (15 000 for a 15 hp project and 30 000 for a 30 hp project).