UC Riverside develops PFAS breakdown method

Island environmentalists weigh in on the new technology.

Ultraviolet light used for water treatment of PFAS. — Courtesy UC Riverside

The University of California, Riverside (UCR) announced in a press release that the school’s chemical engineering and environmental scientists published in the peer-reviewed Journal of Hazardous Materials Letters in November a new method to break down per- and polyfluoroalkyl substances (PFAS) found in drinking water “into smaller compounds that are essentially harmless.” 

PFAS describes a family of long-lasting chemicals that break down very slowly, earning them the nickname “forever chemicals.” Extended periods of exposure to PFAS or high concentrations of the chemicals are toxic. It can affect developing fetuses, the thyroid, liver, kidneys, hormone levels, and the immune system. PFAS were manufactured and used in industrial and commercial products since the 1940s “because of their useful properties,” according to the U.S. Environmental Protection Agency (EPA). There are thousands of different types of PFAS, with varying degrees of usage and understanding of them. The EPA states that PFAS can be found in numerous sources, such as drinking water, food storage (e.g. grease-resistant paper, fast food containers, candy wrappers) products, fire-extinguishing foam, and many more goods.

The Island had its own bouts with the chemicals before, such as hazardous PFAS levels found in private West Tisbury wells. Measures to address the issue have also been taken. Martha’s Vineyard Airport began a pilot PFAS mitigation program using PlumeStop, an activated carbon substance made by the company Regenesis. There is also ongoing litigation in the Martha’s Vineyard Regional High School v. the Town of Oak Bluffs Planning Board case in Massachusetts Land Court, because of the planning board’s rejection of a special permit for a synthetic turf field at the high school over PFAS concerns. 

According to the release, the patent-pending process “infuses contaminated water with hydrogen, then blasts the water with high-energy, short-wavelength ultraviolet light. The hydrogen polarizes water molecules to make them more reactive, while the light catalyzes chemical reactions that destroy the pollutants.” The “one-two punch” breaks the “strong fluorine-to-carbon” chemical bonds that make PFAS “so persistent and accumulative in the environment.” The release states that the “molecular destruction” of PFAS using the new method, when compared with other ultraviolet water-treatment methods, increased from 10 percent to nearly 100 percent. 

The versatility of the PFAS breakdown method’s application was underscored by UCR Associate Professor in chemical and environmental engineering Haizhou Liu, who was the corresponding author of the paper. 

“The technology will work for all types of water sources, including drinking water, wastewater, brine, hazardous industrial wastewater, and landfill leachate,” Liu told The Times.

Additionally, no other undesirable byproducts or impurities are generated, and “the cleanup technology is green.” 

“After the interaction, hydrogen will become water. The advantage of this technology is that it is very sustainable,” Liu said. 

PFAS has been a rising concern for regulators. The EPA held a public comment period this fall on whether to designate two PFAS substances, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), as hazardous material under the Comprehensive Environmental Response, Compensation, and Liability Act, also known as the “Superfund.” California’s State Water Resources Control Board issued an order this year for public drinking water providers to test for PFAS, the release states. In Massachusetts, a PFAS Interagency Task Force was appointed by the state legislature in 2020 to investigate PFAS contamination in the water and ground, according to the state’s Department of Environmental Protection. A report was issued by the task force in April, which made several recommendations for Massachusetts to implement “in order to protect public health and the environment from PFAS contamination.” Former Massachusetts Attorney General and now Governor-elect Maura Healey sued 13 manufacturers of PFAS used in firefighting foam in May for “causing millions of dollars in damages” to communities across the state “by knowingly contaminating drinking water sources, groundwater, and other natural resources with highly toxic PFAS chemicals that pose a serious threat to public health and the environment.”

Liu’s lab received a $400,000 grant from the National Science Foundation to develop the method, and the “regulatory push,” particularly from California and federal agencies, led his team toward commercialization with support from a $50,000 proof-of-concept grant from UCR’s Office of Technology Partnership to “scale up this technology to handle larger volumes of water,” according to the release. Liu said the patent is being pursued for “commercialization and licensing” purposes, and “one of the markets” that the technology will be offered to is municipalities with PFAS concerns. 

Ben Robinson, Tisbury commissioner on the Martha’s Vineyard Commission and an Island leader in climate change–related resilience planning and adaptation, said he heard about Liu’s method when the paper was published. 

“It is good to see the development of treatment methods, and let us hope that the technology is scalable and affordable. We will need it. Already public and private wells and water supplies on the Vineyard show PFAS exposures above safe limits, and we know that ubiquity of this class of chemicals already in the environment,” Robinson said. “It is clear we will need to clean our drinking water supplies, as well as slow down the prevalence of this chemical family in our product environment.” 

Robinson noted that PFAS dangers were first outlined in the 1960s by chemists who “developed it for various companies when they tested toxicity on rodents.” However, he said this information “was suppressed to protect the profitability of the products.”

“The EPA identified the concern in 2000; now in 2022, we are still allowing their use in many consumer products,” Robinson said. “We should follow the precautionary principle instead of ignoring the serious health and environmental concerns of manmade compounds, this being just the latest example that will take significant investment to clean up.” 

Brendan O’Neill, executive director of the Vineyard Conservation Society, felt that the technology was promising. “Any small steps like this are welcome,” he said. 

O’Neill did point out that UCR’s “process was most effective with nonacidic water flows.” 

“In many places in the world, like M.V., acid precipitation and soil conditions make acidic water. Neutralizing that is one more cost,” O’Neill said. 

When asked about this observation, Liu said, “The process will work across different acidity and alkalinity, and can be adjusted depending on the pH of the water. In addition, pH adjustment to acidic water to a neutral level can be done relatively easily prior to the PFAS treatment.” 

Vineyard Conservation Society ecologist Jeremy Houser said he had written a commentary in August about a different potential PFAS-destroying method published in Science, a peer-reviewed journal, in the nonprofit’s newsletter, The Conservation Almanac. While Houser views these as promising advancements, he expressed doubt over their effectiveness in eliminating PFAS on a large environmental scale. 

“New discoveries that might lower the costs of cleaning up PFAS are useful insofar as they make it more likely that the cleanup is actually done, but as the Almanac piece explains, the larger problem with PFAS pollution is its ubiquity, and the diffuse nature of it,” Houser said. “Methods that work to destroy PFAS once it is isolated and collected can’t be broadcast over the whole environment, so for now the benefit of these new methods would be mostly limited to point source pollution.”

Houser said this limitation means “the far more important issue remains keeping PFAS from entering the environment in the first place.”