Can water treatment technologies truly remove forever chemicals from drinking water?

How well do these technologies actually remove PFAS from water?

The most effective technologies can remove over 90% of PFAS, but performance depends heavily on the specific technology and the type of PFAS. Nanofiltration (NF), a membrane process similar to reverse osmosis, removed 98% of total PFAS from groundwater contaminated with firefighting foam, producing drinking water with only 1.4 ng/L total PFAS — well below most proposed safety limits [1]. Ion exchange (IX) resins, which act like chemical sponges, achieved over 90% removal for 35 different PFAS compounds when given enough contact time (24 hours), though shorter contact times were less effective for some chemicals [2]. Granular activated carbon (GAC), the most common treatment, can also be highly effective, but its performance varies: one study found that increasing the frequency of GAC replacement to meet stricter PFAS targets produced a net health benefit of 6.9 to 300 disability-adjusted life years per million people per year [3].

However, conventional treatment methods — the kind used in most municipal water plants — are essentially useless against PFAS. A study of a drinking water system in China found that removal efficiency for PFAS in each processing unit was 'almost zero' [7]. Even worse, a study in Chennai, India, found that PFAS concentrations actually increased by 5% to 103% after conventional treatment, likely because treatment chemicals or processes released PFAS already present in the system [5]. This means that for most people served by standard water treatment plants, PFAS are not being removed at all.

The persistent problem: what happens to the PFAS after removal?

Removing PFAS from water is only half the battle — the chemicals don't disappear, they just move to a different medium (like spent filters or concentrated waste), and that waste must be dealt with. For example, nanofiltration produces a concentrated 'reject' stream containing the removed PFAS. One study addressed this by using foam fractionation on that concentrate, achieving 90-94% additional removal and producing a small, highly concentrated foamate (just 2% of the original water volume) that contained PFAS at 41 times the original concentration [1]. This doesn't destroy the PFAS, but it dramatically reduces the volume that needs further treatment or disposal.

Thermal destruction is one way to truly break the 'forever chemical' cycle. A full-scale study of GAC reactivation (heating spent carbon to high temperatures to restore its effectiveness) found that the process achieved >99.9% destruction removal efficiency of PFAS, with no detectable PFAS on the reactivated carbon and emissions well below regulatory limits [4]. This suggests that combining removal with thermal destruction can permanently eliminate PFAS, though the energy costs and emissions from the heating process itself must be considered [3].

For ion exchange resins, regeneration (cleaning the resin so it can be reused) is possible but incomplete. One study found that using simple salt solutions could release up to 94% of short-chain PFAS from general-purpose resins, but long-chain PFAS and PFAS-specific resins showed 'no meaningful regeneration' without organic solvents [2]. This means that for many applications, the spent resin becomes a PFAS-laden waste that must be incinerated or landfilled, potentially re-releasing the chemicals into the environment.

Are there any emerging approaches that might change the game?

Researchers are exploring several novel methods that could complement or replace current technologies, though most are still in early stages. One promising approach uses aquatic plants (phytoremediation): a study of 18 wetland plant species found that some, like Eriophorum angustifolium and Carex rostrata, could absorb and even degrade PFAS, with enzymes (peroxidases and laccases) playing a role in breaking down the chemicals [9]. The effectiveness depended on having high plant biomass relative to water volume, suggesting this could work for treating contaminated wetlands or as a polishing step.

Hydrogel adsorbents are another emerging technology, particularly for short-chain PFAS, which are harder to remove than long-chain ones. These materials offer high adsorption capacity and fast uptake, but they are prone to biofouling (microbial growth) that reduces their effectiveness. Researchers are working on antibiofouling modifications, but the authors note that 'there is a lack of studies on the development and evaluation of hydrogels with both biofouling resistance and short-chain PFAS removal capabilities' [6].

Even aeration — simply bubbling air through water — can help, by concentrating PFAS at the air-water interface where they can be more easily captured by activated carbon. Molecular dynamics simulations showed that PFAS molecules are thermodynamically driven to the air-water interface (with free energies 3-7 kcal/mol lower than in bulk water), and that longer-chain PFAS like PFOS are more strongly held there than shorter ones like PFBS [8]. This explains why aeration enhances GAC performance, though it's not a standalone solution.

About These Sources

This answer is built on 9 peer-reviewed studies — published from 2021 to 2025, 4 from 2024 or later, 6 in Q1 journals, collectively cited 424 times — selected as the most relevant from 11 studies that passed quality screening, drawn from 57 papers retrieved from a database of over 500 million.

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