Read the full article by John Wiegand (MIT Technology Review)
“The PFAS sample slides around the inside of the plastic jar when I swirl it, dark and murky, like thin maple syrup. For many, these toxic so-called ‘forever chemicals’ amount to something of a specter, having crept into our lives—and bodies—quietly for more than half a century. In the environment, PFAS are clear and odorless. We may hear about them in the headlines, consider them when we turn on the tap for a glass of water or a shower, but we don’t see them. We can’t touch them. Except that’s exactly what I find myself doing.
PFAS stands for ‘per- and polyfluoroalkyl substances,’ a family of upwards of 15,000 or more human-made and incredibly durable chemical compounds that have been used in countless industrial and consumer applications for decades. Firefighting foams, waterproof hiking boots, raincoats, nonstick frying pans, dental floss, lipstick, and even the ink used to label packaging—all can contain PFAS. The compounds are ubiquitous in drinking water and soil, even migrating to Arctic sea ice. PFAS are called forever chemicals because once present in the environment, they do not degrade or break down. They accumulate, are transferred throughout the watershed, and ultimately persist.
The quest to reduce the amount of PFAS in the environment is what led me to an industrial park in a southern suburb of Grand Rapids, Michigan. The jar of PFAS concentrate in my hand is part of a demonstration arranged by my hosts, Revive Environmental, during a tour of the company’s PFAS destruction site, one of the first in the country to operate commercially and at scale. A few yards in front of me sits the company’s PFAS ‘Annihilator’ in a white shipping container.
The Annihilator represents just one of several technologies now vying to break down and destroy PFAS. These span the gamut from established processes like electrochemical oxidation and supercritical water oxidation to emerging techniques relying on ultraviolet light, plasma, ultrasound, or catalyst-driven thermal processes. Some are deployed in field tests. Other companies are actively running pilot programs, many with various divisions of the US Department of Defense and other government agencies. And many other technologies are still undergoing laboratory research.
There’s good reason for this. Not only are PFAS everywhere around us; they’re also in us. Humans can’t break down PFAS, and our bodies struggle to clear them from our systems. Studies suggest they’re in my blood and yours—the majority of Americans’, in fact—and they have been linked to increased risks of kidney and testicular cancer, decreased infant birthweights, and high blood pressure. And that’s only what we know about now: researchers continue to grapple with the full impacts of PFAS on human and environmental health.
Revive’s Annihilator and other nascent destruction technologies show the first signs of promise that these ‘forever chemicals’ can be removed from the environment permanently, limiting further human exposure and risk. But destroying PFAS is only one step in the full remediation process. Across the globe, researchers are developing new technologies and techniques to better understand, test, and track the chemicals—as well as identifying alternative materials—to eliminate PFAS for good.
Breaking it down
PFAS traces back to the mid-20th century, when the chemical giant 3M invented PFOA (perfluorooctanoic acid) to prevent nonstick coatings from clumping during production. Eventually, 3M began selling the material to fellow chemical companies, including DuPont, which used the material for its then revolutionary coating, Teflon. Later other manufacturers, such as Chemours and Corteva, would develop and produce their own brands. The health impacts of PFAS and extent to which the chemicals had pervaded the environment wouldn’t be discovered until the early 2000s, when legal action against DuPont unearthed evidence that chemical companies knew some of the risks PFAS posed to human health yet intentionally dumped them into waterways and unprotected holding ponds, where they eventually made their way into drinking water and people.
Though it has been years since the initial hazards of PFAS were made public, scientists and regulators have since struggled with how best to remediate the contamination and keep people safe. Traditionally, PFAS are treated through standard water filtration methods: granular activated carbon, reverse osmosis, ion exchange resins. These methods work extraordinarily well to capture PFAS. The problem is, though, that once captured, the chemicals don’t go away. The filters are discarded or chemically washed for reuse, and the notoriously clingy PFAS reenter the environment through landfills and wastewater. Incineration—another traditional mitigation technique—risks sending undestroyed PFAS compounds up the smokestack and into the air. All the while, PFAS continue to be manufactured, used, discarded, and circulated through the environment. And so the hunt is on for a way to make the forever chemicals a bit more ephemeral.
For the Annihilator, Revive uses a destruction method called supercritical water oxidation (SCWO) to cleave the durable carbon fluorine bonds that characterize PFAS compounds. In another shipping container, which serves as the monitoring station for the Annihilator, David Trueba points to a bank of computer monitors displaying data from the various sensors inside the destruction device. Trueba is the president and CEO of Revive and serves as one of my guides on the tour. SCWO is essentially a PFAS pressure cooker, he explains, heating and compressing the contaminated liquid to a supercritical state of above 500 °C and 3,200 PSI. In that state, where water is caught in a sort of purgatory between liquid and gas, oxygen becomes soluble, and the resulting oxidation drives the reaction that ultimately destroys the PFAS. Among other applications, SCWO has been used to decommission and destroy old stockpiles of mustard gas, the brutal chemical weapon that plagued the trenches of World War I. Battelle, a national research nonprofit, adapted SCWO to target PFAS and spun off Revive as a private entity with investment from Viking Global Investors in January 2023.
After the PFAS is destroyed, the solution undergoes several post-treatment procedures. Then it’s cooled and pumped into plastic totes for storage and eventual discharge to the local wastewater treatment plant. The finished product is aqua blue, resembling water you might see at a Caribbean beach, and Trueba says it tests below Michigan’s maximum contaminant level standards for PFAS.
Approaches and targets
Revive’s destruction operation targets PFAS in landfill leachate—a scientific term for what occurs when rainwater passes through landfill waste, absorbing chemicals and contaminants from the decomposing material along the way. Landfill leachate is one of the primary sources of PFAS contamination, which is unsurprising since that’s where many PFAS-laden products end up.
Earlier in the tour we’d walked to an adjacent facility where a pair of workers, clad in heavy jumpsuits, hard hats, and boots, manned a hose running from the back of a polished-steel semi-trailer. The workers were pumping leachate trucked from a nearby landfill by Heritage-Crystal Clean, an environmental services company that’s partnered with Revive. The smell was about what you’d expect from a brown, sludgy cocktail of decomposition.
‘It’s the smell of money,’ Trueba said. Later, he told me: ‘Innovation, in my mind, is not just an idea, but it’s getting paid for it. It’s getting the value in the market because the market values that it’s being adopted.’
That may sound a bit brutally capitalistic for a widespread societal issue like PFAS, yet experts point to the very real-world issues of cost facing the companies and municipalities footing the bill for PFAS destruction. As much as there’s a race to destroy PFAS, there’s also a race to do it as cost-effectively and efficiently as possible. And Revive, with its brand of SCWO technology, isn’t the only one running the track.
‘It’s important that this problem isn’t a tens or hundreds of trillion dollars problem. It needs to be kept to, like, a multibillion-dollar problem,’ says Daniel Cho, founder and CEO of Onvector, a water treatment company using plasma technology to destroy PFAS.
Video of Onvector’s technology shows a bright-blue flickering light, similar to a welding arc, accompanied by a high-pitched screech. During our conversation, Cho refers to the technology as ‘lightning and fire reliably delivered inside a flowing cyclone of water.’ It’s a catchy phrase, meant to contain several PhDs’ worth of science in a neat, memorable package. In reality, the technicalities are more complex.
Onvector’s technology combines the actions of a centrifugal separator with an electrode that ionizes gas injected into the device. The resulting reaction creates high-energy electrons that attack and break down the PFAS compounds. The system is currently deployed at Joint Base Cape Cod in Massachusetts and was partially supported through grant funding from AFWERX, the skunkworks division of the US Air Force. Cho expects to fully scale Onvector in 2024, he says.”…