Chemical pollutants are bad news for the environment, but some types of pollutants are more harmful than other types of pollutants,media New Atlas reported. Toxic substances such as PFAS and GenX are called “permanent chemicals” because they last long in the environment. Researchers at Rice University have discovered a powerful new tool that they say can help neutralise the threat. They found a new catalyst that could destroy them in a matter of hours.
The trouble with “permanent chemicals” such as perfluororide and polyfluoroalenic substances (PFAS) is not only that they stay in the environment for long periods of time, but also how widely they are used. More than 4,000 compounds are among these chemicals, which appear in everything from waterproofcloths and non-stick pots to fire foams and food packaging. Studies have also shown that tap water and almost all Americans have these compounds in their blood.
Rice University’s team hopes to build on earlier work to develop catalysts for other chemical contaminants, such as trichloroethylene (TCE) and nitrates. Through a lengthy trial and error process, researchers have found some success in the synthetic mineral boron nitride (BN) in perfluorooctanoic acid (PFOA), one of the most common PFAS chemicals.
“The observation sway,” said Michael Wong, the study’s director. “You take a water bottle with some PFOA, you throw it in your BN powder, and then you seal it. That’s it. You don’t need to add any hydrogen or purify it with oxygen. Just the air we breathe, contaminated water and BN powder. You expose it to ultraviolet light, especially UV-C light at a wavelength of 254 nanometers, and come back four hours later, 99% of the PFOA has been converted into fluoride, carbon dioxide and hydrogen. “
These promising results have prompted researchers to explore the potential of the catalyst to process other “permanent chemicals”. In the United States, PFOA has been largely phased out, but other synthetic “permanent chemicals” have been replaced, including a chemical called GenX.
“It’s similar to the PFOA story,” Michael says. “They can find GenX everywhere now. But one difference between the two is that people have previously reported some success in degrading PFOA with catalysts. For GenX, they haven’t. “
But Michael and his team may have found a potential way forward. Their experiments showed that BN can also destroy GenX at 254 nanometers of light, and although the effect varies, about 20 percent of the GenX in the water sample is destroyed after two hours of exposure.
The researchers say they already have ideas on how to improve the performance of catalysts in handling GenX. They also patented the technology and hope to continue developing its application in water treatment systems as one of the original applications.
“We tried a lot of things,” Michael said. “We tried a few materials and I thought it would be useful. None of them succeeded. This should n’t be effective, and it does. “
The study was published in the journal Environmental Science and Technology Letters.