NSF invests in engineering research to remove PFAS from the environment

The U.S. National Science Foundation has funded nine fundamental research projects to create new strategies to remediate perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the environment. PFAS persist and accumulate in soil, water and living organisms, and they can lead to adverse health effects.

The extreme chemical stability of PFAS is one attribute that has led to their widespread use in food packaging, nonstick pans, stain-repellant fabrics, electronics, fire-fighting foams and many other commercial applications.

However, once PFAS enter the environment, their stability becomes a problem. The chemicals are very resistant to degradation and are largely impervious to conventional water treatment methods, such as municipal drinking water treatment.

"NSF has long supported research on the prevention, mitigation and remediation of environmental pollution to protect the health of people and the planet," said Richard Dickinson, director of the NSF Division of Chemical, Bioengineering, Environmental and Transport Systems. "With these new studies, NSF hopes to enable effective, feasible and sustainable technologies to remedy PFAS contamination across the nation."

What makes PFAS endure are the strong bonds between carbon and fluorine. PFAS have many fluorine atoms to create their desired properties. PFAS include perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorobutane sulfonic acid (PFBS), GenX and other chemicals. While some early PFAS chemicals have been phased out in the U.S., they, as well as later replacements, can still be found in the environment, food and drinking water.

With more than $4.1 million in combined funding, the new research projects will use a variety of approaches to treat PFAS contamination, whether by capturing the chemicals or breaking their carbon-fluorine bonds to turn PFAS into benign products. Researchers will investigate biological technologies, chemical catalysis technologies, photolytic technologies and physical treatment technologies.

"Remediation of PFAS has been a difficult engineering challenge due to their unique environmental properties," said Karl Rockne, who coordinated the NSF Environmental Engineering program during his rotation as an NSF program officer. "They have both water-repelling and water-soluble properties, which makes separating these compounds from water and soil efficiently very challenging. Once captured, their extreme chemical stability makes them very difficult to degrade."

Rockne continued, "These nine projects will employ novel, cutting-edge strategies that address the twin engineering challenges of separation and destruction and that hold high potential for developing breakthrough technologies."

The nine projects for engineering research to advance solutions for environmental PFAS are funded through 13 awards:

• A "concentrate-and-destroy" technology for treating per- and polyfluoroalkyl substances using a new class of adsorptive photocatalysts: Auburn University, award 2041060; and University of Maryland, Baltimore County, award 2041059.
• Development of quantitative tools to assess the mechanisms and full potential of UV-ARPs for the treatment of PFASs in water: Texas A&M University, award 2050934; and California State University, Long Beach, award 2050882.
• Electrocatalytic hydrodefluorination of PFAS using molecular, metal-free catalysts: University of Cincinnati, award 2051260.
• Mechanistic investigation of thermal decomposition of poly- and perfluoroalkyl substances in the soil environment: University of North Dakota, award 2047062.
• Microbial electrochemical defluorination of PFAS using bioaugmented Acidmicrobium sp. Strain A6: Princeton University, award 2055015.
• Nickel and palladium single-atom electrocatalysts for selective capture and destruction of PFAS in complex water matrices: Yale University, award 2120418; and Clarkson University, award 2120452.
• Remediation of per- and polyfluoroalkyl substances in wastewater using anaerobic membrane bioreactors: SUNY at Buffalo, award 2112201; and the University of Southern California, award 2112651
• Tunable vacuum-ultraviolet irradiation systems with highly polarized redox environment for treatment of per- and polyfluoroalkyl substances: University of California, Riverside, award 2131745
• Understanding the surface-active properties of PFAS for enhanced removal by bubbling-assisted water treatment processes: SUNY at Stony Brook, award 2052772

This new research on the treatment and remediation of PFAS is co-funded by the Environmental Engineering program in the NSF Division of Chemical, Bioengineering, Environmental and Transport Systems and an unrestricted gift to the NSF from DuPont de Nemours Inc.