Could light overcome “eternal pollutants”? A team of researchers is proposing an innovative method to break down PFAS, these persistent chemicals that contaminate our environment.
PFAS, used in many products for their non-stick and waterproof properties, are known for their extreme strength. Their chemical structure, based on carbon-fluorine bonds, makes them almost indestructible by traditional methods. These compounds accumulate in water, soil and living organisms, posing serious risks to health and the environment.
A team from Colorado State University developed a photocatalytic technique using light to break down these stubborn bonds. Their system is based on a photocatalyst organic activated by LEDs, which transfers electrons to PFAS molecules, causing their degradation. This approach works at low temperature and metal-free, making it safer and potentially more economical. PFAS, found in cookware, textiles and firefighting foams, are nicknamed “perennial pollutants” because of their persistence in the environment. Their natural degradation can take up to 1,000 years, and current treatment methods only concentrate them, not eliminate them. completely.
A new photocatalytic technique aims to transform PFAS into non-toxic products, such as hydrocarbons and fluoride ions, which can then decompose naturally. This process, described in the journal Naturerepresents a promising advance for the decontamination of water and soil.
However, everything is not perfect yet. The current system only works on a small scale and cannot degrade the most complex PFAS molecules, like Teflon. Additionally, the photocatalysts used degrade over time, requiring improvements for long-term use.
Researchers are now considering adapting this technology to treat contaminated water in wastewater treatment plants. They also hope to use it to remediate polluted soil, making it suitable for agriculture and preserving ecosystems again.
This method adds to other approaches in development, such as electrochemical oxidation and plasma destruction. Combined, these technologies could offer a comprehensive solution to eliminate PFAS efficiently and sustainably.
What is photocatalysis?
Photocatalysis is a chemical process that uses light to activate a reaction. It is based on a catalystoften a material semiconductorwhich absorbs theenergy light and transmits electrons. These electrons then initiate chemical reactions, such as the degradation of pollutants or the production of useful molecules. Unlike traditional methods, photocatalysis works at low temperatures and without harsh chemicals. It is therefore considered a clean and sustainable technology. Its best-known application is the breakdown of toxic substances in water or air, such as PFAS or volatile organic compounds.
The most commonly used photocatalysts are titanium dioxide (TiO₂) and certain organic compounds. These materials are chosen for their ability to absorb light and maintain their effectiveness over long periods of time. However, their performance depends on the length wave of the light used, often in the spectrum ultraviolet or visible.
The advantages of photocatalysis include its low energy cost and its environmental friendliness. It is already used in applications such as self-cleaning surfaces, air purification and wastewater treatment. With continued research, it could play a key role in the fight against pollution and the transition to greener technologies.
