2024.02 Foam fractionation for PFAS removal

Foam Fractionation of Concentrates for the Removal of PFAS

Concerns about the occurrence of highly persistent organic substances, such as per- and polyfluoroalkyl substances  (PFAS), in all major water bodies used for drinking water production have steadily been increasing in recent years. To ensure the quality of our drinking water, there is an urgent need to effectively remove these substances. Membrane filtration, using nanofiltration and reverse osmosis, can effectively remove PFAS from the produced drinking water. However, during filtration, a retentate stream with elevated concentrations of PFAS is produced. To protect the source water bodies and reduce the overall PFAS load in the environment, additional treatment of these retentate streams is required. One promising removal technology to reduce the load of PFAS is the use of foam fractionation. During foam fractionation, the target substances are concentrated at the bubble interface. The PFAS-laden foam can subsequently be removed, making it highly relevant for a broad scope of water treatment processes.

Research challenges
While foam fractionation has proven effective in concentrating PFAS in a variety of matrices, a limited foundational understanding of the presence is currently available. It’s known that cations can affect the foam fractionation process beneficially. Additionally, the  presence of certain co-surfactants can enhance the concentrating factor of foam fractionation. However, the mode of interaction of these constituents and PFAS during the process are not fully understood. Currently, foam fractionation is able to effectively remove long-chain PFAS, but cannot effectively concentrate and remove persistent, short-chain PFAS. By improving our foundational knowledge of the foam fractionation process, we aim to fully unlock the potential of foam fractionation and further develop the technology for the removal of PFAS.

Your assignment
Your work aims to increase the foundational knowledge of the foam fractionation process for the removal of PFAS. To achieve this, you will be investigating foam fractionation in a controlled environment. You will study a broad range of PFAS at environmentally relevant concentrations to get an understanding of the role of their concentration on the process efficiency. You will investigate the delicate interplay between the matrix and process conditions. You will systematically study in the impact of the water matrix, gas composition and process parameters to enhance the PFAS concentrating factor and removal efficiency. Effective removal methods of PFAS from the process will be explored to further enhance the process. You will translate these results into enhancements for the foam fractionation process that you will implement in larger-scale, environmentally relevant conditions to evaluate your findings in real conditions.

Your Profile
You have a master’s degree in chemical engineering, process engineering, environmental engineering or similar. You are a highly motivated student with an affinity for physicochemical processes and process engineering. You are willing to delve into topics outside of your current knowledge base and enjoy working in a dynamic, multidisciplinary, and international environment.

Keywords: PFAS, foam fractionation, micropollutants, separation processes, water treatment

Supervisory Team: University promotor and co-promotor: Dr. Ir. Slawomir Porada (Wroclaw University of Science and Technology, Faculty of Chemistry, Wroclaw, Poland)
Wetsus supervisor: Dr. Ir. Maarten Biesheuvel, Dr. ir. Sam Rutten

Project partners: Advanced Water Treatment

Only applications that are complete, in English, and submitted via the application webpage before the deadline will be considered eligible.

Guidelines for applicants:  https://phdpositionswetsus.eu/guide-for-applicants/