Per- and polyfluoroalkyl substances (PFAS) are often called “forever chemicals” for a reason. Engineered for extreme chemical stability, they resist natural degradation and can persist in the environment for decades. PFAS have been widely used in products ranging from firefighting foams to industrial coatings, but the same durability that made them useful has now become a serious environmental liability. As concerns over toxicity and bioaccumulation grow, most remediation strategies today focus on destroying PFAS as completely and safely as possible.
Yet this dominant narrative overlooks a critical aspect of PFAS. PFAS are not just pollutants. They are also rich in fluorine, a strategically important element underpinning modern chemical manufacturing, pharmaceuticals, and energy technologies. In most current treatment approaches, this embedded fluorine value is irreversibly lost. Our recent work asks a different question: instead of viewing PFAS solely as contaminant to eliminate, can they be reimagined as a resource to recover?
At the same time, the world faces another pressing challenge. The rapid expansion of electric vehicles and grid-scale energy storage has driven unprecedented global demand for lithium. Traditional lithium production from hard-rock mining is energy- and chemical-intensive, while brine-based extraction relies on slow evaporation processes that can take months or even years, consuming vast amounts of land and water. As lithium becomes increasingly central to the clean-energy transition, developing faster, cleaner, and more sustainable recovery routes has emerged as a global priority.
Our work was motivated by a simple but powerful idea: to connect these two seemingly unrelated problems—PFAS pollution and lithium scarcity—into a single, integrated solution.
At Rice University, our research group led by Prof. James M. Tour developed a new strategy called electrothermal fluorination (ETF). This work builds upon their prior research achievements, including the electrothermal mineralization of per‑ and polyfluoroalkyl substances (PFAS) in soil (Nat. Commun., 2024, 15, 6117) and PFAS adsorbed on granular activated carbon (GAC) matrices (Nat. Water, 2025, 3, 486). Instead of treating PFAS as something to burn or bury, we use their fluorine content directly as a chemical reagent to help recover lithium from brine.
The process relies on ultrafast electrical heating, known as flash Joule heating, which delivers intense heat in a fraction of a second. We combine brine salts with granular activated carbon that has already been used to capture PFAS from aqueous film-forming foam (AFFF), a widely used firefighting formulation. When a brief electrical pulse is applied, the mixture heats and cools fast within seconds. Under these extreme but tightly controlled conditions, PFAS are broken down and their fluorine is converted into non-toxic inorganic fluoride, without generating new persistent fluorinated byproducts.
That fluoride then plays a crucial role. It selectively reacts with lithium-containing salts in the brine. Because brine contain many dissolved ions, lithium is notoriously difficult to isolate. Instead of trying to “catch” lithium using complex membranes or sorbents, our approach changes lithium’s chemical identity, transforming it into lithium fluoride (LiF), a form that can be separated far more easily from the rest of the mixture.
From there, lithium recovery follows a straightforward path. After fluorination, simple washing removes the more soluble salts, followed by a brief electrically driven distillation that isolates lithium fluoride from the remaining components (Fig. 1a). Using a range of fluorine-containing waste streams, this approach delivers lithium fluoride with high purity and high recovery yields (Fig. 1b).
Fig. 1. ETF process for lithium extraction from brine. (a) Overview of the lithium recovery pathway, where fluorine from PFAS-containing waste is used to transform brine salts and enable lithium separation through a simple, three-step process. (b) Lithium purity and recovery efficiency achieved using different fluorine sources.
In short, this work offers a clear case of “one stone, two birds”: pollution management and resource recovery achieved together in a single system. PFAS, often regarded as some of the most problematic environmental contaminants, are not merely destroyed. Instead, they are converted into a useful fluorine source. At the same time, lithium, a critical material for batteries and clean energy technologies, is recovered more efficiently and with a smaller environmental footprint. Even the carbon materials used in the process are upgraded into graphene, creating an additional value stream rather than secondary waste.
Life-cycle assessments and techno-economic analyses underscore this advantage. Compared with conventional lithium extraction routes, the ETF approach shows lower energy demand, reduced greenhouse gas emissions, and less water consumption. When the value of both the recovered lithium products and co-produced graphene is considered, the process also becomes economically compelling.
Besides, the electrothermal processing is inherently well suited for scale-up. Because heating is internal and occurs rapidly, the same principles can be extended in larger reactors with higher throughput. In our work, we demonstrate larger-batch operation using upgraded power systems, pointing toward future industrial deployment with even lower energy cost per unit of lithium recovered.
More broadly, this research reflects a shift in how we think about waste. Instead of following a linear model of produce, use, and then discard, it embraces a circular approach, where even the most persistent contaminants can be transformed into valuable inputs for clean-energy technologies. By reframing PFAS as a fluorine feedstock rather than an intractable problem, this work offers a new perspective on how environmental remediation and resource sustainability can advance together.
In a world grappling with both pollution and resource scarcity, solutions that address multiple challenges at once may be exactly what the energy transition needs.
Full text link: https://doi.org/10.1038/s44221-026-00593-1.