PFAS — per- and polyfluoroalkyl substances — are a family of several thousand synthetic compounds. They are nicknamed “forever chemicals” because the carbon-fluorine bond that characterises them is extremely stable: they barely degrade at all in the environment.
Where they come from
Non-stick coatings, water-repellent textiles, grease-resistant packaging, firefighting foams, industrial processes. They reach water through industrial discharges, fire training grounds and leaching from soil.
Why they are a concern
Their persistence allows them to accumulate in the environment and in living organisms. Health authorities are progressively tightening the limits applicable in drinking water, which is pushing operators to equip themselves.
What actually removes them
- Granular activated carbon: effective mainly on long-chain molecules.
- Ion exchange resins: selective and effective, including on short-chain compounds.
- Reverse osmosis: the broadest barrier, applied at the point of use.
Conventional sediment filtration or UV disinfection, by contrast, has no effect at all on these compounds.
The other emerging pollutants
Pharmaceutical residues, endocrine disruptors, microplastics: these families share the same characteristic. They are present at trace level and escape treatment trains designed for conventional contaminants. That is what justifies thinking in terms of successive treatment stages rather than a single piece of equipment.