A University of Maine researcher and professor thinks he may have found a way to remove the “forever” from “forever chemicals.”
Over the next three to four years, Onur Apul, an assistant professor of environmental engineering, will investigate how to destroy forever chemicals, or PFASs, that accumulate in a common water filtration technology used by US municipalities.
Apul’s work will be boosted by a recently announced $250,000 grant from the National Science Foundation.
His work on removing PFAS from granular activated carbons, a key component of the filter, comes as Maine and much of the rest of the country are reaching agreement on how to address PFAS contamination.
PFAS chemicals that have been used for decades in the manufacture of products such as nonstick cookware and rainwear. The chemicals, which have been linked to a number of health problems, have become widespread in the environment because they don’t break down, and the question of how to destroy them is attracting more attention and research.
When drinking water systems use granular activated carbons to filter chemicals from drinking water, the carbons become loaded with PFAS that they trap. When they are used up, they usually end up in landfills for safekeeping, but the cycle of PFAS contamination continues there.
PFAS chemicals then end up in liquid runoff from landfills. That runoff then ends up in wastewater treatment facilities that are not required to treat wastewater for PFAS. Those facilities dump treated water into rivers, continuing the cycle of contamination.
But some scientific work has already shown that a system used to recycle granular activated carbons could also destroy PFAS captured in the carbons, stopping the waste cycle dead in its tracks, Apul said.
“PFAS is a unique class of contaminants because they are virtually indestructible,” Apul said. “Those natural methods, nothing really destroys them. We are dealing with a practically indestructible chemical substance, but of course, nothing is really indestructible. Try giving it to my little boy.”
With other chemicals and substances, there’s almost always a natural way to destroy them, he said. Whether through the sun or other natural chemical reactions, nature is full of ways to break things down, but not PFAS, Apul said.
Using ultraviolet light or facilitating chemical reactions to force the destruction of PFAS has so far proven too costly or too difficult, he said.
“PFAS is a persistent chemical, so it keeps circulating in the environment,” Apul said. “The big conceptual idea is to find where it accumulates and destroy it.”
Apul’s background is in engineering and water treatment, which led him to look to existing systems as a means of disposing of these chemicals. That’s when he came up with the idea, Apul said.
If granular activated carbons are not used to capture PFAS, they can be recycled through thermal regeneration, heating the carbon and extracting the liquid, allowing the carbon to be reused, he said.
Some existing research has shown that PFASs attached to these carbons break down through thermal regeneration, nullifying the idea that PFASs really last forever, Apul said.
So Apul will spend the next few years trying to figure out what properties of granular activated carbon and PFAS cause toxic chemicals to break down, an effort to improve the chemical destruction process without hindering carbon recovery for reuse, he said.
Essentially, Apul and his team are taking preexisting technology and trying to use it to find a solution to a problem that affects Maine and the rest of the country.
“We don’t need to build new reactors. We don’t need to buy new chemicals. No need to invest in infrastructure,” he said. “Anything we look at in the lab would work in an engineered system, which is a pragmatic way to do it.”
