PFAS Remediation Techniques

The techniques at a glance

Every PFAS remedy in use today falls into one of three groups: in situ sequestration in the aquifer, separation from pumped or treated water, and destruction of a concentrate. The table is the short version; the sections below give the detail.

Technique	Medium	Status	What it leaves behind
Colloidal activated carbon barrier	Groundwater, in situ	Field-validated for plume control; the standard in situ approach	PFAS held on carbon in the aquifer; monitoring continues
Granular activated carbon (GAC)	Pumped water, drinking water	Full scale, most common ex situ treatment	Spent carbon for reactivation or incineration
Anion exchange resin	Pumped water, drinking water	Full scale; longer bed life than GAC on many waters	Spent single-use resin for incineration, or regenerant brine
Reverse osmosis / nanofiltration	Water	Full scale, usually point-of-entry or polishing	Concentrate, typically 10 to 20% of the feed, still needing treatment
Powdered activated carbon dosing	Water treatment plants, batch wastewater	Full scale for spikes and interim control	Carbon leaves with the sludge
Foam fractionation	High-concentration water	Commercial on leachate and AFFF-impacted water; growing	A small volume of PFAS-rich foamate for destruction
Excavation and disposal	Soil	Full scale	Soil moved to a landfill or incinerator
Soil stabilization with sorbents	Soil, sediment	Full scale where leaching, not mass, is the driver	PFAS immobilized in place; leach testing proves it
Thermal destruction (incineration, SCWO)	Concentrates, spent media, soil	Incineration full scale; SCWO early commercial	Fluoride, CO₂ and water when complete; stack emissions managed
Electrochemical, plasma, sonochemical, UV-sulfite	Concentrates	Pilot to early commercial	Partial defluorination unless run to completion

Why PFAS resist the usual remedies

Per- and polyfluoroalkyl substances are built around the carbon-fluorine bond, the strongest single bond in organic chemistry. The permanganate, persulfate and peroxide chemistries that destroy chlorinated solvents and fuels do not touch it, and bacteria do not use it for energy. The regulatory targets are measured in parts per trillion, three orders of magnitude below most other groundwater standards. The family runs to thousands of compounds, and the short-chain substitutes for PFOA and PFOS are more mobile and harder to capture than the long-chain legacy compounds. Plumes are long, and the source is often a fire-training area or airfield where the PFAS arrived with chlorinated solvents, fuels and metals that need treating too.

The regulatory numbers that set treatment targets

In April 2024 the U.S. EPA finalized the first national drinking water regulation for PFAS, with maximum contaminant levels of 4.0 parts per trillion for PFOA and for PFOS, 10 ppt each for PFHxS, PFNA and HFPO-DA (GenX), and a hazard index of 1 for mixtures of PFHxS, PFNA, HFPO-DA and PFBS. In May 2025 the EPA announced it would keep the PFOA and PFOS limits, propose moving the compliance date from 2029 to 2031, and rescind and reconsider the limits for the other four; that rulemaking was still in progress as of this writing. Separately, PFOA and PFOS have been CERCLA hazardous substances since 2024, which brings Superfund liability and reporting into site decisions. Many states, including California, Michigan, Minnesota, New Jersey and New York, carry their own groundwater and drinking water standards, some tighter than the federal numbers. Confirm the applicable standard before sizing any treatment; it decides whether the goal is mass removal, flux reduction or compliance at a tap.

In situ: colloidal activated carbon sequestration

For a PFAS plume moving toward a well, a stream or a property line, the field-validated in situ approach is sequestration on injectable colloidal activated carbon (CAC). The carbon is milled to a few micrometers or less, suspended in water, and injected at low pressure through direct-push points or existing wells. It travels through the formation, deposits on the sediment grains, and turns a band of aquifer into a sorption zone. Groundwater keeps flowing; PFAS do not. Because no trench is dug, a CAC barrier costs a fraction of a trenched permeable reactive barrier and can be placed at depths and under structures where trenching is impossible.

What CAC does not do is destroy anything. The carbon holds the PFAS until its capacity is used or the chemistry changes, so a CAC remedy is a plume-control and risk-reduction remedy with a monitoring plan attached, not a closure in itself. Capacity is finite and site-specific: long-chain compounds such as PFOS and PFOA bind strongly; short-chain compounds such as PFBA and PFBS bind less and break through first; dissolved organic carbon and co-contaminants compete for sites. A bench sorption test on the site’s own groundwater, run before the carbon mass is set, is the difference between a barrier that lasts and one that is re-injected in three years. Field demonstrations funded through the Department of Defense’s SERDP and ESTCP programs are the main published record for CAC on PFAS plumes.

Hepure’s injectable product is Fluxsorb RC: an aqueous dispersion of 6 to 15% activated carbon by weight with particles under 3 µm, supplied in 275-gallon totes, listed for PFAS, hydrocarbons, chlorinated solvents and coal-combustion-residual inorganics. Where chlorinated solvents share the plume, Ferox zero valent iron is placed alongside it to treat the solvents the carbon only holds. Our colloidal carbon page covers how CAC behaves in an aquifer and how it compares with powdered and granular grades.

Soil and sediment

Excavation and disposal remains the most common source-area remedy for small volumes: dig, haul to a landfill permitted for PFAS waste or to an incinerator, backfill. It is fast and certain, and the cost and liability of the off-site disposal are what drive the search for alternatives at larger sites.

Stabilization with sorbent amendments leaves the soil in place or in a lined cell and cuts what leaches out of it. Powdered activated carbon mixed into soil or placed as a layer over contaminated sediment binds PFAS and other hydrophobic organics, and leach tests before and after treatment document the reduction. Dose rates around 1% of soil weight are a common starting point; the bench leach test sets the real number. Fluxsorb RP, Hepure’s powdered activated carbon, is made for this work in soils, sediments and ponds and ships in bulk bags or bulk trailers.

Thermal treatment of soil, either high-temperature incineration or thermal desorption with off-gas treatment, destroys or removes PFAS but at high energy and handling cost; it is used for concentrated source soils and spent media rather than for whole plumes. Soil washing, which moves PFAS into a water stream for treatment, is at the demonstration stage.

Pumped water and drinking water

Granular activated carbon is the most widely installed PFAS treatment: water passes through a packed bed and PFAS adsorb to the carbon. Bituminous coal-based carbons generally outperform coconut-shell carbons on long-chain PFAS, and removal of short-chain compounds is weaker, so beds are sized and change-out scheduled from the short-chain breakthrough. Spent carbon is thermally reactivated or incinerated.

Anion exchange resin binds the negatively charged PFAS molecules selectively and, on many waters, runs far longer between change-outs than GAC, with better capture of short-chain compounds. Single-use resin is incinerated when exhausted; regenerable systems produce a concentrated brine that itself needs destruction. Resin costs more per vessel than carbon, so GAC followed by resin in series is a common layout.

Reverse osmosis and nanofiltration reject more than 90% of PFAS, short chains included, and are the usual choice where the whole PFAS family must be removed at a point of entry. The cost is the concentrate stream, typically 10 to 20% of the feed, which still holds all of the PFAS and needs treatment or disposal, plus energy and membrane fouling.

Powdered activated carbon dosed into a treatment plant or a batch tank removes long-chain PFAS during a spike or as an interim measure and then leaves with the solids. It is not a replacement for a GAC or resin bed in long-term compliance, but it is the tool a plant can deploy this week with no capital project. CarbPure TRA, certified to NSF/ANSI 61, is Hepure’s powdered carbon for potable plants; Fluxsorb RP fits process water, wastewater and batch-treated stormwater where drinking water certification is not required.

Foam fractionation uses PFAS’s own surfactant behavior: fine air bubbles rising through the water carry PFAS to the surface as a foam that is skimmed off, leaving a small volume of concentrate. It works best on high-concentration water such as landfill leachate and AFFF-impacted groundwater and is now deployed commercially at a growing number of sites, usually as the concentration step ahead of a destruction technology.

Destruction: what happens to the concentrate

Every separation technique produces something that still contains the PFAS: spent carbon, spent resin, membrane concentrate, foamate, excavated soil. The EPA’s interim guidance on PFAS destruction and disposal (updated 2024) lists thermal treatment, hazardous-waste landfilling and deep-well injection as the current options and ranks them by how much is known about their emissions. The destruction technologies themselves:

• High-temperature incineration, above roughly 1,000 °C with adequate residence time, is the established route for spent media and AFFF stock; lower temperatures risk products of incomplete combustion.
• Supercritical water oxidation (water above 374 °C and 22.1 MPa) has shown destruction efficiencies above 99% in pilot units and is in early commercial use on concentrates.
• Electrochemical oxidation on boron-doped diamond electrodes, plasma reactors, sonochemical treatment and UV-activated sulfite reduction all defluorinate PFAS in the laboratory and at pilot scale. Energy use and electrode life keep them tied to small, concentrated streams.
• Reductive pathways on zero valent iron are a research topic, not a remedy. Published work shows partial defluorination under laboratory conditions; nothing has gone to full scale, and we say so on our ZVI and PFAS FAQ. ZVI’s place at a PFAS site is the chlorinated solvents and metals in the same plume.
• Biodegradation transforms some polyfluorinated precursors and short-chain compounds slowly and incompletely; it is not a standalone PFAS remedy.

Matching the technique to the situation

Situation	Usual approach	Why
Dissolved plume moving toward a receptor	Colloidal activated carbon barrier	Cuts flux at a fraction of the cost of trenching; placed through existing wells
Source-area soil, small volume	Excavate and dispose	Fast and certain; disposal cost and liability drive the decision as volumes grow
Source-area soil or sediment, large volume	Stabilize with powdered activated carbon; leach test to prove it	Keeps the mass in place and the leachate below the standard
Pump-and-treat or drinking water supply	GAC, resin, or both in series; RO where short chains must go	Established, permitted, sized from breakthrough curves
Treatment plant spike or interim control	Powdered activated carbon dosing	Deployable immediately with existing feed equipment
Landfill leachate or AFFF-impacted water	Foam fractionation, then destruction of the foamate	Concentrates the PFAS before the expensive step
PFAS with chlorinated solvents or metals in one plume	Colloidal carbon plus Ferox zero valent iron	Carbon holds the PFAS; iron destroys the solvents and immobilizes the metals

What Hepure supplies for PFAS sites

Hepure supplies the carbon and the co-contaminant chemistry; it does not design the remedy or run the injection. Fluxsorb RC colloidal carbon in 275-gallon totes for injected barriers; Fluxsorb RP powdered activated carbon in bulk bags or bulk trailers for soil mixing, sediments and batch water treatment; CarbPure TRA powdered activated carbon, certified to NSF/ANSI 61, in supersacks or pneumatic bulk trailers for treatment plants; and Ferox zero valent iron, oxidants and bioremediation amendments for the solvents, fuels and metals that share the site. Send Pat (West, x1) or Bob (East, x2) the PFAS results, the co-contaminant data, the hydrogeology and the delivery address, and you will get a product recommendation and a quantity estimate; we recommend a bench sorption test on the site’s water before the carbon mass is fixed. The cost differences between colloidal, powdered and granular carbon are set out on our colloidal carbon FAQ.

Common questions

What is the most effective PFAS remediation technique?

For water, granular activated carbon and anion exchange resin are the proven full-scale treatments, with reverse osmosis where short-chain compounds must be removed. For a plume in the ground, colloidal activated carbon sequestration is the field-validated approach. No single technique handles every PFAS, every medium and every concentration, so most sites run a treatment train: capture, concentrate, destroy.

Can PFAS be destroyed?

Yes, in a concentrate. High-temperature incineration is established; supercritical water oxidation, electrochemical oxidation and plasma have shown near-complete destruction at pilot scale and are entering commercial use. In an aquifer, no: destruction in situ remains a research goal.

How long does a colloidal carbon barrier last?

Until the sorption capacity in the treated zone is used, which depends on the PFAS flux, the chain-length mix and the competing organics in the water. The bench sorption test and the mass flux calculation give the estimate; the monitoring wells confirm it. Re-injection extends it.

What are the EPA drinking water limits for PFAS?

4.0 ppt each for PFOA and PFOS, finalized in April 2024, with compliance proposed for 2031. The 10 ppt limits for PFHxS, PFNA and HFPO-DA and the hazard index were under reconsideration as of this writing; check the current rule and your state’s standard.

Does zero valent iron treat PFAS?

Not at field scale. ZVI has shown partial defluorination in the laboratory and remains a research subject. It is used at PFAS sites for the chlorinated solvents and metals that usually accompany the PFAS, alongside a carbon barrier for the PFAS itself.

GAC or ion exchange?

GAC costs less per vessel and handles long-chain PFAS well; resin captures short-chain compounds better and runs longer between change-outs on many waters. The breakthrough curve from a column test on your water, not a rule of thumb, makes the choice, and many systems use both in series.

References

• U.S. EPA. PFAS National Primary Drinking Water Regulation, final rule, April 2024; announcement of reconsideration and compliance-date extension, May 2025.
• U.S. EPA. Interim Guidance on the Destruction and Disposal of PFAS and Materials Containing PFAS, updated 2024.
• U.S. EPA. Designation of PFOA and PFOS as CERCLA Hazardous Substances, final rule, April 2024.
• Interstate Technology and Regulatory Council (ITRC). PFAS Technical and Regulatory Guidance Document, treatment technologies section.
• SERDP/ESTCP. Field demonstrations of colloidal activated carbon for in situ PFAS plume control.