Foam fractionation tackles tough PFAS streams

AqueoUS Vets, a US-based water contaminant removal technology specialist, has released a novel foam fractionation system that can handle tough-to-treat Per- and polyfluoroalkyl (PFAS) streams from industrial processes.

Foam fractionation approved by the US EPA

The FoamPro system uses an innovative vacuum process that, according to its creators, improves mass transfer efficiency and reduces energy consumption when compared to conventional foam fractionation technologies.

The system is housed in a vertical unit that is taller than it is wide, which has the benefit of requiring only a small footprint on site, and which aids the foam process.

And while the system has been in use in more than 100 non-PFAS treatment applications for some time, it has recently been validated by the US Environmental Protection Agency (EPA) for removal of so-called forever chemicals from hard-to-treat wastewater streams.

Industries across the board are grappling with the challenge of treating PFAS in complex waste streams

AqueoUS Vets president & CEO Dr Mirka Wilderer told Aquatech Online: “Industries across the board are grappling with the challenge of treating PFAS in complex waste streams. This breakthrough technology marks a significant innovation, equipping our customers with an additional, powerful tool to address the growing PFAS problem.”

She added: “By integrating this solution into our portfolio of media filtration technologies, AqueoUS Vets reinforces its commitment to delivering the most sustainable treatment options with the lowest total cost of ownership. There is no single solution when it comes to PFAS remediation, and AqueoUS Vets is proud to offer customers greater flexibility in identifying the approach that best meets their needs.”

A versatile solution for PFAS removal

The system can be delivered and installed in modules, offering a ‘plug and play’ system to meet needs. Module flow ranges from 0.5 to 100 gallons a minute.

The versatility of the FoamPro system makes it suitable for a wide variety of PFAS industrial removal applications, these include:

• Aqueous Film Forming Foam (AFFF) rinse water
• Groundwater remediation
• RO brine
• Landfill leachate
• Textile wastewater
• Semiconductor & microelectronics wastewater
• IX / GAC pre-treatment.

The system also has the benefit of being able to remove volatile and semi-volatile organics, and to precipitate iron and manganese.

FoamPro testing on Aqueous Film Forming Foam (AFFF) rinse water

In testing before it was released commercially, the system was successfully treated on Aqueous Film Forming Foam (AFFF) rinse water with initial concentrations of perfluorooctane sulfonate (PFOS), perfluorohexane sulfonic acid (PFHxS) and perfluorooctanoic acid (PFOA) in the tens of thousands of parts per trillion. The tests resulted in a more than 99 per cent of the contaminants being removed.

Wilderer added: “The results to-date inspire confidence that the FoamPro solution will meaningfully impact the PFAS treatment space, reducing the overall cost burden on industry and taxpayers alike.”

How does foam fractionation work?

Foam fractionation works by passing air bubbles up through a wastewater solution that contains PFAS chemicals. The air bubbles attract the surface-active PFAS chemicals which are attracted to their air-liquid interface. The bubbles rise through the solution to the top of the chamber where they form a foam, which can be removed and further treated.

The method has gained popularity because it eliminates the need for chemicals, solvents, filter material, and adsorbents. The US government is also ramping up its efforts to remediate the PFAS contamination problem with new legislation, such as making polluters pay to clean waste streams.

[Image Credit: Angel Chyi En We,Arash Zamyadi,Anthony D. Stickland,Bradley O. Clarke,Stefano Freguia: A review of foam fractionation for the removal of per- and polyfluoroalkyl substances (PFAS) from aqueous matrices  published in Journal of Hazardous Materials]