Battelle is the latest organization to combat per- and polyfluoroalkyl chemicals (PFAS), using supercritical water oxidation technology to fight contaminants. And his solution may still have the boldest name: PFAS Annihilator.
PFAS, or so-called forever chemicals, persist in the environment. They have been found in water, air, fish and soil in places around the world and linked to harmful effects on the health of humans and animals. But Battelle says its technology will make it difficult to continue calling them chemicals “forever,” says Amy Dindal, PFAS program manager for Battelle, based in Columbus, Ohio.
“The final product consists of inert salts and PFAS-free water,” says Dindal, summarizing the results of a recent demonstration pilot project at a wastewater treatment plant in Michigan. There, a mobile Annihilator was used to “safely and completely destroy” the PFAS in the contaminated water at a facility operated by Heritage-Crystal Clean.
PFAS chemicals are a concern because they have been used extensively in everything from non-stick cookware to food packaging and fire fighting foams. Now that federal agencies and others are trying to tackle PFAS, with phasing out and cleaning, Battelle’s technology and that of companies like 374Water and Aclarity are in high demand.
“It’s really about state, federal, government, commerce, industry, nonprofit organizations like Battelle working together that we will achieve success,” says Dindal.
The US Environmental Protection Agency has identified more than 120,000 locations in the United States where people can be exposed to PFAS. So there is a lot of work to be done.
But let’s go back to the Annihilator. It works by sucking up contaminated wastewater, then mixing hydrogen peroxide, isopropanol as a co-fuel, and sodium hydroxide as a neutralizing agent.
“After going through a heat exchanger, an oven removes the salts,” explains Battelle. “Then the water enters the reactor at a temperature and pressure designed to break the carbon-fluorine bond.
“The resulting production is carbon dioxide and hydrofluoric acid which is neutralized with sodium hydroxide which transforms it into inert salts.”
This is the inert Dindal was talking about. There are carbon dioxide emissions, she says, but those are “significantly below any regulatory level.”
Battelle says that in testing over 30 types of PFAS-contaminated samples, the Annihilator has consistently demonstrated destruction greater than 99.99% of the total PFAS.
It’s enough? Yes, because even though there is no national PFAS cleanliness standard in the United States, Dindall notes that the guidelines generally require at least 99% destruction.
At the pilot site, located in Grand Rapids, Michigan, the Annihilator worked for 10 days to remove PFAS from leachate samples, says Brian Recatto, president and CEO of Heritage-Crystal Clean, based in Elgin, Illinois.
“Personally, I thought the unit worked very well,” Recatto says. “We were in parts per trillion levels of contamination and, at the end of the treatment process, far below what we think will be the standards for drinking water.”
Dindal notes that chemical destruction by supercritical water oxidation has existed since the 1980s, used by agencies such as the Department of Defense to treat chemicals and stocks. Battelle optimized it during three years of research, eliminating PFAS in hundreds of samples from around the country.
The mobile unit is now upscaling. Some larger units are under construction. The new Annihilators will be 10 times larger, similar in size to a container, and will be deployed to commercial and government sites later this year.
Battelle and Heritage-Crystal Clean recently signed an agreement to collaborate in the destruction of the PFAS. Heritage has eight commercial wastewater treatment plants and customers asking for ways to remove PFAS from waste before it goes to public wastewater treatment plants, Recatto says.
Heritage plans to help Battelle apply its technology, with on-site Annhilator systems operational by the end of the year.
The CEO says Heritage is talking to some interested customers “and I don’t think we’ll have a problem finding a buyer.”