Researchers at Australia’s national science agency, CSIRO, are joining the global effort to clean up PFAS. Here, three CSIRO scientists share their insights into what PFAS are and how they can be destroyed safely and permanently.
Per- and polyfluoroalkyl substances (PFAS) are man-made chemicals that do not degrade naturally and are often referred to as “forever chemicals.”
There are more than 15,000 types of PFAS, which are used in a wide variety of commercial, consumer, and industrial products due to their excellent stability, heat resistance, and oil and water repellency. Examples include nonstick cookware, waterproof textiles, cleaning products, construction materials, and traditional firefighting foam. However, the properties that make PFAS useful also make them difficult to clean up.
From “eternal chemicals” to “everywhere chemicals”
Once PFAS enter the environment, they can travel long distances through air, water, and soil. They can accumulate in ecosystems and organisms. Over the past few decades, they have spread around the world and have been detected in areas such as Antarctica.
CSIRO senior research scientist Dr Divina Navarro said PFAS were now used in so many products that it was not always possible to pinpoint their source.
“PFAS molecules are made up of carbon and fluorine bonds and are very strong and stable, which is why PFAS are so persistent in the environment.
“This molecule also has what we call a ‘water-loving head’ and a ‘water-repellent tail’ that help it easily move across the interface between air, water and soil.
“Concentrations of PFAS vary from place to place. Part of our job is to measure that and be able to advise governments and regulators on what background concentrations of PFAS compare to pollution.”
Are PFAS dangerous?
Exposure to high levels of PFAS can affect human, plant, and animal health. For example, a recent study of freshwater turtles showed that exposure to high levels of PFAS coincides with increased incidence of deadly diseases, malformations in hatchlings, and population declines.
Much research is still underway in Australia and around the world to understand how this happens and what concentrations of PFAS pose a significant health risk. But one thing is clear: PFAS pose a global problem, and innovative solutions are needed to safely detect, contain, and destroy PFAS.
How do we track PFAS in the environment?
In some cases, it’s obvious where to look for PFAS. For example, traditional firefighting foams containing PFAS were once commonly used at airports and military bases. That’s why CSIRO researchers are working with the Department of Defense to better understand how PFAS move through the environment. They have also helped develop ways to limit its spread.
PFAS can also accumulate in surface and groundwater and eventually reach wastewater treatment plants. This poses a major challenge for water utilities around the world.
Most treatment processes are not designed to remove PFAS, so PFAS often end up in biosolids, a byproduct of wastewater treatment that is used as fertilizer for agriculture.
“We’re understanding the cycles of matter and following the fate of matter so we can target where it might be,” Dr. Navarro said.
“Our team is building models based on what we discover about how PFAS move through surface water, groundwater, and different types of soil.
“Whether PFAS leaches from soil quickly or more slowly depends on the amount of organic carbon, clay, and minerals present.
“By collecting more data on how well different soils hold PFAS, we can train and test models to predict where PFAS will end up.”
How can you tell if PFAS are present in your soil or water?
PFAS are used in so many products that it is not always possible to trace their source. Another way scientists can detect PFAS is by testing soil and water samples.
But testing a group of more than 15,000 chemicals is no easy task. CSIRO senior research scientist Dr Robert Young said that for some methods to be effective, scientists already needed to know the chemical composition of the substance they were trying to detect.
“The method of manufacturing PFAS may not be very selective, so the product can contain a huge number of different fluorinated compounds,” Dr. Young said.
“Other test methods cast a wider net, but are not necessarily as good at distinguishing between individual molecules in a mixture.”
That is why CSIRO invested in a new ion cyclotron resonance (ICR) facility in Adelaide in 2025. Detect up to tens of thousands of chemicals in a single sample, helping control contamination.
ICR is excellent at distinguishing individual molecules by mass, even in very complex mixtures such as soil. Look for useful patterns in your data, such as the long carbon-fluorine chains that make up PFAS.
This precision allows scientists to detect contaminants such as PFAS much more quickly and effectively than other methods.
“ICR has the potential for rapid response. In the case of a chemical spill, samples can be taken and analyzed for the presence of high-priority contaminants in as little as a day,” Dr. Young said.
How can we remove PFAS from the environment?
Getting PFAS out of the environment and destroying it is a huge challenge and an expensive one.
In the case of hotspots, soil and other materials can be removed and destroyed in areas where PFAS are known to be present in high concentrations. In soil, PFAS can be bound in place by adding adsorbents. In contaminated waters, floating wetlands have proven effective in removing PFAS.
CSIRO Principal Research Scientist Dr Jens Brotevogel and his team are working with partners in Australia and overseas to test ways to permanently remove PFAS.
“In the grand scheme of things, we’re talking about extracting the equivalent of a few drops of water from an Olympic-sized swimming pool,” Dr. Brotevogel said.
“We can’t fix the whole world, so we need to be smart and targeted about how we deal with PFAS.
“Typically, we filter PFAS through granular activated carbon, ion exchange resins, or membranes to produce a more concentrated waste stream.
“Then you can use destructive techniques to process that waste. That’s the expensive part.”
Can “eternal chemicals” be destroyed?
The strong chemical bonds in PFAS are specifically created to withstand the tests of heat, UV light, oxidation, and time that cause small molecules to break down. Therefore, scientists around the world are researching different ways to destroy PFAS.
These include pyrolysis (heating without oxygen), gasification (heating with a small amount of oxygen), supercritical water oxidation (heat and high pressure like in a pressure cooker), and alkaline hydrothermal treatment (heat and high pH).
A new discovery shows how materials contaminated with PFAS can be safely destroyed by burning them.
Many of these methods are still being tested for effectiveness in destroying PFAS or in the scale-up phase. So CSIRO researchers, along with researchers in the US and Germany, are focusing on the two most promising treatments to safely destroy large quantities of PFAS.
One is to burn materials containing PFAS at high temperatures of around 1,000°C in specialized hazardous waste incinerators. Once completely petrified, all that remains are inorganic compounds such as calcium fluoride, carbon dioxide, and water.
The other, called thermal desorption, evaporates pollutants and leaves the soil structure intact so it can be reused.
Is it really safe to incinerate PFAS?
To safely and completely destroy PFAS, there is one final piece of the puzzle.
“When you do any heat treatment, you have to deal with emissions,” Dr. Brotevogel said.
“Treatment of PFAS with high heat breaks the bonds between carbon and fluorine, but it can also create harmful airborne chemicals, which can cause problems of their own if released into the environment.
“Our main goal is to understand all the steps in the mechanism by which PFAS degrade and how variables such as oxygen, water, and surface amounts affect that process.
“Doing so will allow us to apply our knowledge to a variety of thermal technologies to safely and completely destroy PFAS.”
An international team has already traced the entire chain of chemical reactions as PFAS decomposes during incineration. We were also able to find a way for recyclers to destroy PFAS in batteries while recovering valuable metals.
CSIRO researchers are leveraging international collaboration and cutting-edge technology to tackle our biggest challenge: reclaiming eternity from eternal chemicals.
Check out the new facilities that are revolutionizing the way we protect the environment.
This article will be published in an upcoming PFAS Special Focus Publication in January.
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