The problem of per- and polyfluoroalkyl substances, or PFAS, a group of potentially cancer-causing “forever chemicals,” may finally have a solution, thanks to German scientists.
The PFAS group contains more than 10,000 synthetic substances that refuse to break down, leading to the term “forever chemicals,” and which instead build up in the body to cause developmental issues, immune problems, and even cancer.
Now, Helmholtz-Zentrum Dresden-Rossendorf (HZDR) researchers have reported not one, but two new solutions to the forever chemical problem in recent papers published in the journals Chemical Engineering Journal Advances and Scientific Reports.
One of these new processes for addressing this long-standing environmental problem employs hydrodynamic cavitation, while the other employs cold atmospheric plasma combined with gas dispersion.
Forever Chemicals Explained
PFAS have exceptionally stable carbon-fluorine bonds, which make them difficult to break down. Through industrial wastewater, these forever chemicals are released into oceans and rivers, where they can accumulate in plants, animals, and humans. While some of them are tied to specific health risks, many are still question marks, with their health consequences unclear.
The work at HZDR is part of Germany’s “National Water Strategy,” aimed at protecting the country’s water supplies. In a 2022 preliminary study that the new work built on, researchers degraded PFAS chemicals through a hydrodynamic cavitation process.
Work on these new processes was conducted at the Helmholtz Center for Environmental Research (UFZ), confirming that both processes degrade PFAS and produce fluoride, which the researchers hope will soon be adopted in industry.
The First Solution
“In hydrodynamic cavitation, we pass PFAS-enriched water through a constriction, generating small vapor bubbles,” explained co-author Dr. Sebastian Reinecke, head of the Department of Water and Environmental Technologies at HZDR. “When the bubbles burst under the rising ambient pressure in the water downstream of the constriction, the PFAS that are attached to the bubbles are exposed to local temperature spikes of several thousand degrees Celsius.”
While this occurs, highly reactive hydroxyl radicals form during cavitation, which the team believes then attack intermediate products, hastening the breakdown of PFAS.
The researchers demonstrated that PFAS chemicals in tap water were broken down, with higher concentrations of fluoride produced as treatment duration increased. A persistent and well-studied PFAS, perfluorooctane sulfonate (PFOS), was used in the research, with 37% of the dissolved chemical eventually breaking down.
“We are now conducting follow-up experiments to increase the degradation rate,” Reinecke added. “Our goal is to improve the process to a degradation rate of more than 80 percent of the PFAS in the solution and mineralizing more than 50 percent of the fluorine that is bound in the chemicals – that means, breaking down the carbon-fluorine bonds that are typical of PFAS.”
Plasma Vs. PFAS
Dr. Amit Kumar, an environmental engineer at HZDR, led another series of experiments on cold atmospheric plasma and gas dispersion, which offered the advantage of not requiring catalysts or additional chemicals. Kumar applied some of his previous research on breaking down micropollutants to the problem of forever chemicals.
“We generated plasma at the water surface while simultaneously introducing gas into the PFAS-contaminated water,” Reinecke explained. “The PFAS attach to the surface of the gas bubbles. As they rise, the water is constantly circulated. This brings the PFAS to the surface, where they are broken down in the plasma.”
Roughly 35% of the fluorine atoms in these forever chemicals were released as fluoride salts in the process, almost completely degrading long- and short-chain PFAS.
“While this method has significantly faster reaction kinetics than cavitation, it also consumes far more energy per volume unit,” Reinecke notes. “In addition, the process generates numerous transformation products that we have not yet been able to investigate in detail – for instance, gaseous compounds that form during the reaction.”
Scaling PFAS Degradation
With their central ideas proven, the researchers are now focused on scaling up these processes for industrial-scale wastewater applications. Part of this involves increasing the reaction volume from 50 milliliters to 5 liters and combining the two separate processes.
“I believe we’ll achieve high degradation rates by combining the highly reactive species from the plasma with the effects of cavitation,” says Reinecke.
Additionally, follow-up work is currently investigating whether any byproducts of the plasma process are harmful and how to mitigate those effects.
Merging the techniques could lead to a highly efficient new PFAS removal technology, providing a powerful tool for dealing with one of the most significant threats to clean water supplies.
The paper, “Enhanced Degradation and Defluorination of Perfluorooctane Sulfonate (PFOS) in Tap Water Using Gas-Dispersed Cold Atmospheric Plasma,” appeared in Scientific Reports on June 13, 2026, and the second study, “Degradation and Defluorination of Perfluorooctane Sulfonate (PFOS) Forever Chemical in Water Using Hydrodynamic Cavitation Treatment,” appeared in Chemical Engineering Journal Advances on March 26, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.