Developing knowledge on practical scale to solve PFAS problem

For many years up until 2014, fire-extinguishing exercises were carried out on the Utrecht University campus to train the company emergency response staff who work there. Until recently, the fire-fighting foam contained PFAS, which is a collective name for chemicals that have water-, grease- and dirt-repellent properties, and are not or barely degradable in the environment. The chemicals ended up in the soil, and this place – very conveniently located on academic land – is now the site of the four-year PFAS Living Lab-project that was launched on 1 September 2024.

Understanding PFAS

The Living Lab is a test bed in which researchers and students investigate the behaviour of PFAS in the soil and seek measures to sustainably clean up such contaminants. The activities are part of KWR’s extensive research into PFAS, says Van Leeuwen, the project’s scientific coordinator. ‘We want to develop knowledge on a practical scale with the aim of solving the PFAS problem. It is therefore important to understand how PFAS behave in the soil. Because if these chemicals are present in the shallow soil, they can also penetrate to the deeper soil levels. If PFAS reach the groundwater, the quality of the raw water from which drinking water is produced is threatened. The added value of a Living Lab is that it allows you to carry out tests in the living environment. That’s on a larger scale than between four walls under laboratory conditions. Instead of working on a single soil type under controlled conditions, in the field you’re dealing with a variety of soil types each with its own characteristics. That makes it more difficult to come up with solutions, but it also gives you a better idea of the ultimate outcomes.”

Multidisciplinary approach

Although the project only got under way last spring, the first scientific paper has already been submitted for consideration. The paper presents the results of successful experiments in which PFAS are leached from the soil through the use of biodegradable soap. In addition, a number of other methods are in the line-up for the collection of new knowledge on sustainable PFAS remediation. Van Leeuwen: ‘Think of electrostatic sorption of PFAS in the soil, about which little is known. With this technique, through an electrical charge, the PFAS become, as it were, glued to a particle such as a mineral. We also test a variety of materials – the so-called “sorbents” – to which PFAS become attached. And we want to develop remediation techniques using bio- or geo-chemical barriers. When a PFAS contaminated groundwater plume turns up, a “reactive screen” of this type can be used to prevent it from spreading further. In addition, we study the impact of PFAS on the ecology.’ Thus, an extremely broad approach, which draws on a variety of scientific disciplines, and is also conducted jointly with KWR as a knowledge institute that works in water practice. ‘To come up with remediation solutions, you need to operate collaboratively on various approach pathways,’ says Van Leeuwen. ‘That is really the most efficient way.”

Photo: Esther Meijer

Photo: Esther Meijer

Photo: Esther Meijer

Photo: Esther Meijer

Nice interplay

By fulfilling a research function both at Utrecht University and at KWR, Van Leeuwen moves between fundamental science and practice. ‘At the university we use the Living Lab to investigate research questions related to PFAS. We try to link these to the situation in the field. Conversely, in my KWR work, I come across practice locations that face problems related to PFAS that need to be solved. I wouldn’t be able to tackle challenges of this sort if I belonged solely to the academic community. In this context we are currently working at KWR on a project proposal for the Province of Gelderland, where there are questions concerning PFAS. They heard about our Living Lab and came to us with a question that consultancies can’t solve, because they don’t have the knowledge and equipment. A nice interplay.”