Water
,
caustic soda
and a
common organic reagent
brought to a
boil
: this is enough to permanently get rid of one of the most widespread classes of
Pfas
, the dreaded chemical contaminants that pollute water and soil, threatening human health and the environment.
Researchers from Northwestern University in the United States have discovered this.
Their 'recipe', published in the journal Science, is the first so simple and low-cost: this could pave the way for similar methods to degrade other types of Pfas as well.
These substances have been used for
more than 70 years as non-
stick
and
waterproofing
agents
, for example in cookware, cosmetics, fire fighting foams, water repellent fabrics and products that resist grease and oil.
They have earned the nickname of '
eternal pollutants
' for their extraordinary thermal and chemical stability, which makes them capable of resisting most natural degradation processes.
Currently there are techniques to destroy them, such as incineration, but they require large amounts of energy and very high temperatures, with high costs.
This problem was brilliantly overcome by researchers led by chemist William Dichtel, who discovered the
Achilles 'heel
of one of Pfas' most abundant classes.
These molecules, in fact, are made up of
long chains of carbon and fluorine atoms
(apparently indestructible) at the end of which there is a head formed by
charged oxygen atoms
.
To decapitate it, just mix the Pfas with water, the dimethyl sulfoxide solvent and caustic soda, bringing everything to a boil: once the molecule loses its 'head', a series of reactions is triggered that fragments the chain into non-toxic by-products.