A researcher has found a new approach to eliminate ‘forever chemicals’ from our drinking water by heating PFAS with granular activated carbon. This breakthrough is crucial for addressing concerns related to PFAS-laden waste, biosolids, and spent adsorbent materials, which worry both farmers and communities.
A scientist from the University of Missouri has unveiled an innovative technique for removing so-called “forever chemicals” from our drinking water.
PFAS, or per- and polyfluoroalkyl substances, are synthetic chemicals used in making a variety of products, such as cosmetics, carpets, non-stick cookware, stain-resistant textiles, firefighting foams, food packaging, and waterproof apparel.
These substances are pervasive; they contaminate the environment, our food, and even reside within our bodies. Research has demonstrated that PFAS exposure can lead to reduced fertility, developmental issues in children, and an increased likelihood of certain cancers. Moreover, these chemicals take hundreds to thousands of years to decompose.
For nearly a decade, scientists have been exploring methods to either extract PFAS from the environment or to convert them into safe, inorganic substances.
Now, Feng “Frank” Xiao, an associate professor at Mizzou’s College of Engineering, together with his team, has discovered a straightforward solution that utilizes readily available materials and equipment.
“You don’t require organic solvents or extremely high temperatures,” Xiao, an expert in PFAS degradation, shared. “Simply heat the PFAS with granular activated carbon (GAC).”
GAC consists of small granules made from carbon-rich materials like coal or wood that have undergone heating. It is widely utilized for filtering a variety of harmful pollutants from contaminated water and air. Consumers use GAC to purify aquarium water or filter their drinking water, and it is easily available online for just a few dollars per pound.
In a recent study published in the journal Environmental Science and Technology, Xiao and his team explained how they heated PFAS with GAC at 572 degrees Fahrenheit. This process led to 90% mineralization of the PFAS, breaking down these harmful chemicals into harmless, inorganic fluorine.
Previously, achieving such a degree of mineralization required heating above 1292 degrees Fahrenheit, applying high pressure, or using solvents. Xiao’s technique is far more cost-effective and sustainable, as GAC is inexpensive and can be reused multiple times.
Potential applications
The essence of Xiao’s innovation lies in the synergy of GAC and heat.
“With GAC involved, thermal degradation of PFAS occurs much more rapidly, and the mineralization is significantly enhanced,” Xiao explained. “This process is not costly, compared to reverse osmosis, and can be implemented locally using a standard furnace.”
This discovery marks a major advancement in managing PFAS-laden solid wastes, biosolids, and spent adsorbent materials that pose significant issues for farmers and communities alike.
“In the Midwest, we apply numerous herbicides and administer many pharmaceuticals to livestock,” Xiao mentioned. “These substances often contain high levels of PFAS. With this method, we can dramatically decrease the presence of these compounds in our lives.”
Xiao chose to work at Mizzou for the collaborative research opportunities available and the strong academic focus on undergraduate and graduate students.
“I teach environmental courses, and the students genuinely care about the environment. They are concerned about water quality and the health of our ecosystem,” Xiao noted.
Xiao conveys to his students his enthusiasm for practical research and the chance they have to contribute to improving the world through engineering.
“This discovery has meaningful real-world applications as it enables us to successfully and efficiently eliminate forever chemicals and other pollutants from our water,” he stated. “This is the type of technology we truly need.”
