The struggle to minimize the number of dangerous, man-made “forever chemicals” in the environment has achieved significant progress.
There are several applications for perfluoroalkyl and polyfluoroalkyl substances (PFAS) in society, however, they have also been related to cancer and other health issues.
They are known to be incredibly prevalent, with a recent study indicating that all rainfall on Earth contains lethal concentrations.
This is due in part to the fact that PFAS can take thousands of years to degrade, but scientists from the University of California, Los Angeles (UCLA), and Northwestern University have developed a novel method for degrading them.
By heating contaminated water with low-cost chemicals, they began a chemical process that “nibbled away” at ten distinct PFAS.
The method, which produced no toxic byproducts, could potentially make it simpler for water-treatment facilities to eliminate the compounds from drinking water.
There are around 12,000 PFAS that have a variety of applications, including firefighting foams, non-stick coatings on frying pans, and textiles.
Since their creation in the 1940s, numerous scientific studies have connected synthetic chemicals to health concerns.
Even though many manufacturers have eliminated them from their products, they are still commonly identified everywhere.
Their longevity is due to a link between carbon and fluorine atoms that cannot be broken by anything in nature.
PFAS are believed to enter the environment through industrial emissions, packaging transfer, wastewater, and foam evaporation.
Due to their ultra-strong carbon-fluorine bond, they can pass through the majority of water treatment systems unscathed.
For this reason, experts have been frantically searching for methods to remove PFAS from contaminated water sources as soon as possible.
However, the majority of contemporary technologies are harsh and costly, requiring extremely high temperatures, specific chemicals, or UV light irradiation.
Some of the processes generate hazardous byproducts that necessitate further removal operations.
The new method, published today in Science, requires only a common laboratory reagent and temperatures between 176 and 248 degrees Fahrenheit (80 and 120 degrees Celsius).
Perfluoroalkyl carboxylic acids (PFCAs), a kind of PFAS used to manufacture Teflon, were the subject of the study.
These are composed of a lengthy carbon chain with fluorine atoms attached, as well as two negatively charged oxygen atoms at one end.
This is referred to as the “carboxylic acid group” and can react with other molecules.
This carboxylic acid group is separated and water is produced upon heating the PFCA molecule in water with dimethyl sulfoxide (DMSO) and sodium hydroxide.
This subsequently triggered a chemical reaction that, according to co-corresponding author and UCLA professor Kendall Houk, “gradually chipped away at the molecule.”
Professor William Dichtel of Northwestern University stated, “That triggered all of these reactions, and it began spitting out fluorine atoms from these compounds to form fluoride, the safest form of fluorine.”
Although carbon-fluorine bonds are extraordinarily stable, the charged head group is their Achilles’ heel.
Experiments and computer models proved that the sole byproducts were carbon dioxide, formic acid, and fluoride.
All of these are non-toxic, and fluoride is commonly added to toothpaste to prevent tooth decay, therefore there is no maximum amount of water that can be decontaminated simultaneously.
The approach effectively destroyed 10 forms of PFCA and is believed to apply to the majority of the 40% of PFAS that include carboxylic acid groups.
The researchers expect that this will also lead to the development of methods to eliminate the thousands of additional toxins.
Professor Dichtel said in a statement, “There are other groups that do not have the same Achilles’ heel, but each will have its weakness.”
If we can identify it, we know how to activate it so that it may be destroyed.
