Scientists at ETH Zurich have developed a new method to break down certain types of per- and polyfluoroalkyl compounds (PFAS) without using large amounts of energy. The work was published in the scientific journal magazine Little Science (Little Science).
Also known as “forever chemicals,” PFAS are widely used in products such as nonstick cookware and waterproof clothing because of their water- and oil-repellent properties. Their chemical persistence has led to widespread environmental pollution and serious health problems, including cancer and immune system disorders.
In the new study, the team focused on a subgroup of PFAS called perfluorooctane sulfonates, or PFOS. Because of its toxicity, PFOS is now strictly restricted or even banned worldwide.
To break down PFOS molecules and thus separate them in water, researchers have for the first time used piezomaterial nanoparticles. When exposed to ultrasound, they become electrically charged and act as catalysts.
The particles’ electric charge triggers a chain reaction that breaks down PFOS compounds into their component parts. Mass spectrometry showed that their method was able to break down 90.5% of PFOS molecules.
The scientists noted that their method is much more economical than existing methods that require temperatures above 1000°C.
Previous researchers developed A range of methods to remove PFAS from various environments.