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Air Force researchers develop new weapon to cleanse water

Professors Selma Mededovic Thagard and Thomas Holsen, the Clarkson University team responsible developing the enhanced contact electrical discharge plasma reactor. The reactor cleans contaminated water without producing waste.

CLARKSON UNIVERSITY/DVIDS

By THOMAS GNAU | Dayton Daily News | Published: December 3, 2019

(Tribune News Service) — As the Ohio gears up for wider testing of public water systems for potentially harmful chemicals, civilian researchers at Wright-Patterson Air Force Base believe they may be closing in on a new weapon in the battle against toxic water.

Researchers at the base recently completed a two-week field demonstration of a plasma technology they say destroys potentially harmful chemicals perfluorooctane sulfonate and perfluorooctanoic acid — also known as PFOS and PFOA — in groundwater.

This is the only technology that actually destroys PFAS molecules that has been demonstrated at this scale, according to the researchers involved.

And on Monday, Ohio Gov. Mike DeWine’s office announced that the Ohio Environmental Protection Agency (EPA) and the Ohio Department of Health (ODH) will test close to 1,500 public water systems — supplying water for about 90 percent of the state’s population — for PFAS.

Many have expressed concern about keeping the chemicals out of the area’s groundwater.

“ODH and Ohio EPA look forward to working with public and private water systems and local health departments to protect the health of all Ohioans,” ODH Director Amy Acton said.

The Wright-Patterson research was the first field demonstration of a device called the “Enhanced Contact Plasma Reactor,” conducted under an Air Force contract with a New York university, Wright-Patterson said.

The device uses electricity, water and argon gas to not just reduce potentially harmful chemicals but destroy them altogether, according to the Air Force. Wright-Patterson was the installation chosen for the field demonstration.

The argon gas concentrates PFAS at the gas-liquid interface, and plasma is generated at that interface, which then destroys PFAS, said Selma Mededovic, the project’s principal investigator from Potsdam, N.Y.-based Clarkson University.

The base research project involved parking a specially equipped trailer — with the plasma unit, pumps and storage tanks on board — near the area to be treated. With these mobile trailers, any PFAS-impacted source water can be targeted, Mededovic said.

“The field demonstration was quite successful. We were able to achieve regulatory limits imposed by the EPA,” she said.

One wrinkle at the moment: The approach can treat up to just two gallons of water a minute. The objective is to treat greater volumes at greater speed, and armed with an Air Force SBIR award — a Small Business Innovation Research grant — Mededovic’s company, DMAX Plasma, intends to attempt that.

Mededovic said she would like to treat closer to 100 gallons a minute.

Testing and refinement of the technology continue, and there is potential for the process to be deployed as a supplement or add-on to other technologies, such as ion exchange, Mededovic said.

PFAS are a group of man-made chemicals that include different types of substances including some known as PFOA, PFOS, GenX and others. PFAS can be found in a foam used to put out fires, and foams like that were used in training at Wright-Patterson and other military installations to put out aircraft fires.

The firefighting foam has since been phased out by the Air Force.

The base said its drinking water is tested regularly and contains PFOS/PFOA “well below” the EPA lifetime health advisory level. The base is also home to a water treatment facility using granulated activated carbon, and has filtered more than 225 million gallons of drinking water for PFOS and PFOA, so far.

In June, Montgomery County officials expressed concern about the quality of the region’s drinking water, but raised no immediate warning or threat. They also expressed misgivings about information they were receiving from the city on the issue. Dayton city officials responded on the same day, saying the city’s water supply was and is safe.

In an emailed statement, Michael Colbert, Montgomery County administrator, said Monday the county is working with the Ohio EPA on testing for PFAS and other chemicals.

“We will share those testing results when they are available,” Colbert said in his statement. “We appreciate the commitment and leadership demonstrated by our partners at Wright-Patterson Air Force Base, as we work as a region to improve and protect water quality.”

In her own statement, Shelley Dickstein, Dayton city manager, said city leaders are interested in seeing how the Air Force/DMAX technology performs with larger water systems such as Dayton’s.

“The city of Dayton continues to work to provide all our customers with a reliable and affordable source of high quality drinking water,” Dickstein said. “We continue to work with all of our regional partners, such as the Ohio EPA, Montgomery County, and municipalities to share the most recent testing data and collaborate on short- and long-term strategies to ensure the continuous delivery of high quality water to our citizens.”

“PFOS/PFOA is a national issue, and research like this could lead to the breakthroughs we need to address potential contamination,” said Mark Correll, deputy assistant secretary of the Air Force for installations, energy and the environment. “This demonstration is another example of the Air Force’s commitment to our nation, our communities and our environment.”

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©2019 the Dayton Daily News (Dayton, Ohio)
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