What is AFFF?

AFFF and the removal of PFAS from water

AFFF (Aqueous Film Forming Foam) plays a key role in the context of PFAS contamination of water resources. These fluorinated firefighting foams have been used for decades, particularly at airports, military sites and industrial and large-scale fires. As a result of these applications, some of these sites are now among the most relevant hotspots for PFAS contamination in soil and groundwater. Here, PFAS concentrations are often significantly elevated, requiring specially designed and efficient water treatment concepts.

Challenges in removing PFAS from AFFF-contaminated water

The challenge associated with AFFF lies in the chemical complexity of the substances it contains. In addition to well-known PFAS such as PFOS and PFOA, many AFFF formulations contain a mixture of fluorinated surfactants and so-called precursors. Some of these precursors are difficult to detect analytically, but can transform into highly persistent PFAS in the environment or during biological processes. Water treatment concepts must be designed not only for individual target substances, but also for broad groups of substances and variable compositions.

Technical requirements for filtration

Due to the high tenside concentrations in AFFF-contaminated water, standard methods often reach their limits:

• Activated carbon (GAC): Proven for long-chain PFAS, however with reduced service life under high loads. Regular replacement and careful monitoring are required.
• Ion exchangers (IX): Particularly effective for short- and medium-chain PFAS. Higher investment costs, but often better separation performance for complex AFFF contamination.
• Foam fractionation: Uses the surface-active property of PFAS to selectively separate them from the water. Often useful as an upstream or supplementary process to reduce the overall load.

In practice, multi-stage, combined treatment concepts have proven to be particularly robust and sustainable.

Here you can find our PFAS removal solutions.