When a water system says it has removed PFAS, it means the chemicals are no longer in the water leaving the plant. That's real progress for the people drinking it. The PFAS themselves still exist. They've moved somewhere else.
How removal works today
The three most common treatment methods are activated carbon, ion exchange resin, and high-pressure membranes like reverse osmosis. Each one separates PFAS from water. None of them breaks the carbon-fluorine bond, the roughly 485 kJ/mol bond that makes these chemicals so persistent.
Activated carbon. PFAS stick to the surface of carbon granules. When the carbon fills up, it gets swapped out. The spent carbon is landfilled, incinerated, or reactivated at high temperature.
Ion exchange. Charged resin beads grab PFAS as water flows past. Spent resin is either disposed of or regenerated by washing it with a salty solution, which produces a smaller volume of brine loaded with PFAS.
Membranes. Water is pushed through a membrane and the PFAS stay behind in a reject stream, a concentrated leftover that still has to go somewhere.
Every one of these methods produces a second product: a smaller amount of material with a much higher PFAS concentration. Spent carbon. Spent resin. Regeneration brine. Membrane concentrate.
Where that material goes
Mostly to landfills, incinerators, deep-well injection, or storage. Each option has open questions.
Landfills can release PFAS back out through leachate, the liquid that drains through waste. Leachate often goes to wastewater treatment plants, which weren't designed to destroy PFAS either, so some of it cycles back into the environment.
Incineration can break C-F bonds, but only at very high temperatures held for long enough. When combustion is incomplete, it can form smaller fluorinated byproducts. The U.S. EPA's interim guidance on PFAS destruction and disposal openly flags uncertainties like these.
Storage buys time. It doesn't solve anything.
Destruction is its own field
A growing group of companies is working on true destruction: supercritical water oxidation, electrochemical oxidation, plasma, and hydrothermal treatment. They work by applying extreme conditions, meaning very high heat, pressure, or electrical current, and several are already running on concentrated waste streams. They set the performance bar that any new approach has to clear, including ours.
Where we fit
That concentrated waste stream is exactly where we're aiming. Our first program targets PFOA in the brines, concentrates, and regeneration streams that capture leaves behind. A small volume at high concentration is where a catalyst has the best chance of being practical.
Our approach is an enzyme that doesn't exist in nature: a designed protein that holds PFOA in place, paired with a metal cofactor that drives the chemistry, working in water under mild conditions.
Here's where we are, honestly. We have computational designs that bind and orient PFOA around a reactive metal center. We're preparing for wet-lab validation now. We haven't proven degradation yet, and we'll publish what the lab tells us either way.
The short version
Capture moves PFAS. Destruction ends it. The world needs both, and the step between them is where the forever problem is still unsolved.
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