Researchers at the University of Utah are investigating the destruction of “forever chemicals” using lower temperatures than established methods
This research on low-temperature PFAS destruction offers a promising new way to break down these chemicals under less intensive conditions.
The study is being led by Ling Zang, a professor at the University of Utah’s Department of Materials Science & Engineering and an associate dean for research at the Price College of Engineering.
Zang has previous experience researching PFAS
Professor Zang has previously researched PFAS removal through filtration and adsorption, as well as monitoring treatment performance. This new research will build on that by creating a method to destroy the removed PFAS rather than letting it enter another stream and continue to affect public health and the environment.
The method under investigation uses reactive chemicals called nucleophiles, which are strong enough to sever carbon-fluorine bonds in a process known as defluorination. It was found that this method released nearly all of the fluorine as fluoride from several tested PFAS compounds, including PFOA and trifluoroacetic acid.
The method was also efficient in removing the fluorine from two fluorinated plastics (PVDF and PCTFE), which are common in batteries, industry, and munitions.
These tests were conducted at 110 degrees Celsius (230 degrees Fahrenheit) or less for the most part, but some needed to go up as high as 150 degrees Celsius. Until now, most PFAS destruction methods have required temperatures of 1,000 degrees Celsius or more, making this a considerable achievement and offering a potential solution that is much easier to replicate on an industrial scale.
The lower-temperature method offers another environmental advantage, as the higher-temperature method, known as incineration, also risks incomplete breakdown of PFAS, meaning secondary pollutants are possible, such as smaller fluorinated compounds which can be more volatile than the original chemicals and disperse through the atmosphere. The new method avoids this risk.
No specialised conditions required
The method established by the University of Utah’s team highlights that it works in ordinary air and no special conditions or inputs are required, unlike other destruction methods which require inert gas atmospheres, deep-ultraviolet irradiation, highly reactive alkali metals, heavy-metal catalysts, externally applied high pressure, or energy-intensive mechanical processing.
Professor Ling Zang said: “The ultimate goal is to destroy and detoxify PFAS and reduce their hazards, so cleanup does not simply move contamination from water into another waste stream.”
Researchers at Arizona State University have also identified a new technique for breaking down PFAS using hydrogen activation. Read more about this method here.
