Joshua Samba, a fourth-year doctoral student in applied physics working in the Catalysis and Nanomaterials Laboratory of professor Michael Wong, is recruiting undergraduates at Rice University to join a project aimed at ridding landfills of “forever chemicals.”
The project, titled “Chemical-free UV unit that degrades PFAS in landfill leachate using non-toxic boron nitride,” is funded with a $25,000 grant from the U.S. Environmental Protection Agency. Rice is one of 21 student teams in the U.S. selected to join the "People, Prosperity and the Planet" program.
“This is entirely a student-run project, using research that has come out of my lab. The initial funding from EPA jump-starts this important, student-centered work,” said Wong, the Tina and Sunit Patel Professor in Molecular Nanotechnology and chair of chemical and biomolecular engineering.
“PFAS are per-and polyfluoroalkyl substances,” Samba said, “chemicals commonly used to make fluoropolymer coatings and products that are resistant to heat, oil, stains, grease and water. They’re used in many products, including waterproof clothing, food packaging and non-stick cooking surfaces.”
Forever chemicals have been linked to immunity, thyroid, kidney and reproductive problems. One of them, perfluorooctanoic acid (PFOA), has been designated a possible carcinogen, with a half-life of 92 years in the environment and two to eight years in the human body. PFAs are not readily degradable and linger in the environment. Scientists have found them in the blood of virtually all Americans, including newborns.
The EPA grant is rooted in a paper Wong’s group published in 2020 in the American Chemical Society journal Environmental Science and Technology Letters. The researchers discovered that boron nitride (BN) destroyed PFOA faster than any previously known photocatalyst.
“You take a flask of water that contains PFOA,” Wong said, “you throw in your BN powder and seal it up. You don’t need to add any hydrogen or purge it with oxygen. It’s just the air we breathe, the contaminated water and the BN powder. You expose that to ultraviolet light, specifically to UV-C light with a wavelength of 254 nanometers, come back in four hours, and 99 percent of the PFOA has been transformed into fluoride, carbon dioxide and hydrogen. All done at room temperature.”
Wong and his lab group also recently received a $250,000 grant from the National Science Foundation for their proposal titled “Destroying toxic and persistent perfluoroalkyl substances (PFAS) with advanced materials and light.”
Samba and the undergraduates participating in the EPA project will test the technology at landfills in greater Houston. “Any undergraduates with a passion for environmental justice or water treatment research who wish to take part should contact me,” Samba said.