UNDER EMBARGO UNTIL: 16:00 GMT / 12 NOON ET WEDNESDAY 26 MARCH 2025

A new method to recycle fluoride from long-lived PFAS chemicals

Images available via the link in the notes section.

Oxford Chemistry researchers have developed a method to destroy fluorine-containing PFAS (sometimes labelled ‘forever chemicals’) while recovering their fluorine content for future use. The results have been published today (26 March 2025) in Nature.

PFAS – which stands for poly- and perfluoroalkylated substances – have been produced in large quantities for over 70 years. They are found in a wide variety of products including textiles, food packaging, non-stick cookware, and medical devices. Their unique properties come from multiple carbon-fluorine chemical bonds, a particularly strong chemical motif that also explains their resistance to degradation.

This longevity has led to PFAS sometimes being referred to as “forever chemicals”. Their persistence has resulted in widespread contamination around the world. Traces of PFAS have been found in drinking water and livestock, and have been associated with negative human health effects after chronic exposure.

This global problem urgently needs innovative technologies for the detection, recovery, and destruction of PFAS, as well as responsible pipelines to manage PFAS waste.

Now, a team of chemists at the University of Oxford and Colorado State University have shown it is possible to destroy a wide variety of these fluorine-containing PFAS chemicals while also recovering their fluorine content for reuse in industrial processes.

This operationally straightforward method works by reacting PFAS samples with potassium phosphate salts in the solid state. The reactants are ground together with ball bearings, which breaks down the long-lasting PFAS chemicals and allows the researchers to extract the fluorine content from the resulting product. In the study, the recovered fluoride was then used to generate common fluorinating reagents, which worked effectively in industrial reactions.

This recovery of fluoride, for re-entry into the fluorochemical industry, goes towards enabling a circular fluorine economy. This is particularly important given that fluorspar, the mineral from which essentially all fluorochemicals are manufactured, is categorised as critical for many industrial processes by nations around the world. Furthermore, the phosphate used as an activator in the PFAS destruction process was recovered and reused, implying no detrimental impact on the phosphorus cycle.

The team’s method enables the mechanical destruction of all PFAS classes, including those commonly found in products such as non-stick coatings, electrical insulation, and industrial tubing. This means that the fluorine content from everyday waste such as Teflon tape could be recovered and used to generate important fluorine-containing chemicals, including precursors to pharmaceutical and agrochemicals such as cholesterol-lowering statin medications (Lipitor), anti-seizure agents (Rufinamide), and herbicides (Triaziflam).

A serendipitous observation made in the course of a previous study served as a starting point for the team’s investigation. In an earlier set of experiments using a similar ball-milling method, they noticed that the PFAS-containing sealing rings of the ball-milling jars were degraded during the reaction, resulting in higher fluoride yields than expected. They concluded that their process must be breaking down the PFAS in these sealing rings and liberating fluoride. They wondered if the method may be able to break down and upcycle other examples of PFAS, and have now demonstrated that the method does indeed have broad applicability across a wide range of PFAS.

Professor Véronique Gouverneur (University of Oxford), who led the study, said:

“Fluoride recovery is important because our reserves of Fluorspar, essential for the manufacturing of e.g. life-saving medicines, are rapidly depleting due to extensive mining. This method not only eliminates PFAS waste but also contributes to a circular fluorine chemistry by transforming persistent pollutants into valuable fluorochemicals.”

Dr Long Yang (University of Oxford), one of the lead authors of the study, said:

“The mechanochemical destruction of PFAS with phosphate salts is an exciting innovation, offering a simple yet powerful solution to a long-standing environmental challenge. With this effective PFAS destruction method, we hope to shift away from the notion of PFAS as ‘forever chemicals’.”

Work at Colorado State University was led by Marshall Fixman and Branka Ladanyi Professor Robert Paton as part of the Department of Chemistry in the College of Natural Sciences.

Notes for editors:

For any further enquiries please contact: Long Yang (long.yang@chem.ox.ac.uk), Thomas Schlatzer (thomas.schlatzer@chem.ox.ac.uk), Christopher Goult (christopher.goult@chem.ox.ac.uk), or Zijun Chen (zijun.chen@chem.ox.ac.uk).

Images related to this study for use in articles are available at https://drive.google.com/drive/folders/1HTjyB_ji9ASdXgSoCQjKCLqjwotCMAjP?usp=sharing

These are for editorial purposes relating to this press release ONLY and MUST be credited (see file name). They MUST NOT be sold on to third parties.

The study ‘Phosphate–Enabled Mechanochemical PFAS Destruction for Fluoride Reuse’ will be published in Nature at 16:00 GMT / 12 noon ET Wednesday 26 March 2025 doi.org/10.1038/s41586-025-08698-5 To view a copy of the paper before this under embargo, contact one of the researchers above.

About the University of Oxford

Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the ninth year running, and number 3 in the QS World Rankings 2024. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.

Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.

Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 300 new companies since 1988. Over a third of these companies have been created in the past five years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.

About Colorado State University

Colorado State University, one of the nation’s top-performing public research institutions, has more than 33,000 students. Founded in 1870 as Colorado’s land-grant institution, CSU is renowned for its world-class faculty and research and academic programs in infectious disease, atmospheric science, clean energy technologies, human and animal health, environmental science, global business and more. CSU graduates on average carry less student debt and are employed at higher rates than their peers nationwide.

CSU’s College of Natural Sciences studies foundational science – asking fundamental questions and applying knowledge to every field of study. With eight departments and 10 centers, the College is a leader in research, teaching and community engagement, supporting more than 4,500 undergraduates and 700 master’s and Ph.D. candidates.

More information on Professor Paton: https://newsmediarelations.colostate.edu/contacts/robert-paton/
 

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