"Eternal chemicals" PFAS have received increasing attention in recent years. Since they break down extremely slowly, they accumulate in our bodies and can increase the risk of negative health effects over time.
Cheng Zhang, a researcher at the Australian University of Queensland, has developed a technique with his colleagues to remove PFAS from water, both on a small and large scale, which he claims is five to ten times more effective than existing products on the market. The work has been ongoing since 2018.
In many cases, PFAS occur together with other pollutants, but our sorbents can selectively identify and capture PFAS from the pollution sources, says Zhang.
The technique involves adding a substance to the water that absorbs PFAS, which can then be separated from the water. A pilot plant will be built at the water treatment plant in Brisbane, one of the world's largest.
After filtration, we hopefully have PFAS-free water that can be released directly into nature, says Zhang.
Landfills and Taps
He has high hopes for the technique, which he says can also be used on a small scale, in centimeter-sized cylinders in homes to purify drinking water, or in large tanks for heavily PFAS-contaminated water, such as at landfills.
Our sorbent has a very high capacity to remove PFAS. One gram of it can treat several tons of water from a landfill without reaching its maximum capacity.
The researchers also have ideas on what to do with the PFAS sludge that accumulates during the purification process. First, you can break the bond with a solution using ethanol, which is then evaporated, leaving behind solid PFAS. This can then be added to batteries.
We haven't tested it comprehensively in the laboratory. But we have preliminary data showing that PFAS appears to work very well for improving battery performance.
Can be Stopped in the EU
Tove Mallin, a researcher and unit manager at Swedish RISE, says the results are interesting.
But the speculation that it will become so clean, and of just the kind of PFAS needed for new lithium-ion batteries, I think is a bit far-fetched, she says.
Another concern is a proposed EU regulation that bans fluoropolymers, which are used in the sorbent material. This would make it impossible to launch the technology within the EU. Mallin still believes that the technology itself can find other applications.
It's very interesting with new technologies, development is needed, she says.
PFAS stands for poly- and perfluoroalkyl substances and can also be called highly fluorinated substances.
There are over 10,000 PFAS substances. They have been produced since the 1950s and were considered useful due to their ability to repel water, fat, and dirt. They are used, among other things, as impregnation and in paint, cleaning agents, and makeup.
Since they are difficult to break down, they are found everywhere in the environment.
Repeatedly getting PFAS over a longer period can affect health in the long run. Fetuses, infants, and children are believed to be particularly sensitive. Studies have shown that PFAS substances can affect the immune system, birth weight, cholesterol levels in the blood, be reproductive toxins, and increase the risk of certain types of cancer.
Source: National Food Agency, Chemicals Agency
