A UMaine professor is researching how to destroy ‘forever chemicals’

A University of Maine researcher and professor thinks he may have found a way to take the “forever” out of “forever chemicals.” 

Over the next three to four years, Onur Apul, an assistant professor of environmental engineering, will look into how to destroy the forever chemicals, or PFAS, that accumulate in a common water filtration technology used by municipalities across the U.S.

Apul’s work will be propelled by a recently announced $250,000 grant from the National Science Foundation.

His work on removing PFAS from granular-activated carbons — a key filter component — comes as Maine and much of the rest of the country are coming to terms with how to address contamination from PFAS.

PFAS chemicals that have been used for decades in manufacturing products such as non-stick cookware and waterproof clothing. The chemicals, which have been linked with 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 the chemicals out of drinking water, the carbons become full of the PFAS they catch. When they’re spent, they generally end up in landfills for safekeeping, but the cycle of PFAS contamination continues there.

PFAS chemicals then end up in landfills’ liquid runoff. That runoff then ends up at wastewater treatment facilities that aren’t required to treat wastewater for PFAS. Those facilities release 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 might also be able to destroy PFAS captured in the carbons, stopping the waste cycle in its tracks, Apul said. 

“PFAS is a unique class of pollutants because they are virtually indestructible,” Apul said. “Those natural methods – nothing really destroys them. We are dealing with a virtually indestructible chemical, but of course, nothing is really indestructible. Try giving it to my toddler.” 

With other chemicals and substances, there is almost always a natural way to destroy them, he said. Whether that’s through the sun or other natural chemical reactions, nature is full of ways to deconstruct things, but not PFAS, Apul said.

Using ultraviolet light or facilitating chemical reactions to force the destruction of PFAS so far has 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 water treatment and engineering, which prompted him to think about systems already in place as a means of getting rid of these chemicals. That’s when the idea came to him, Apul said. 

If granular-activated carbons are not being used to capture PFAS, they can be recycled through thermal regeneration — heating the carbon and taking the liquid out, allowing the carbon to be reused, he said. 

Some existing research has shown that PFAS attached to these carbons decompose through thermal regeneration, upending the idea that PFAS really do 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 the toxic chemicals to decompose, an effort to improve the chemical destruction process without hindering the recovery of carbon for reuse, he said.

Fundamentally, Apul and his team are taking pre-existing technology and trying to use it to find a solution to a problem plaguing Maine and the rest of the country. 

“We don’t need to build new reactors. We don’t need to buy new chemicals. You don’t need to invest in infrastructure,” he said. “Whatever we observe in the lab would work in an engineering system, which is a pragmatic way of doing it.”