Together with EPOC Enviro, CDM Smith scientists have been rigorously testing a new treatment train that targets PFAS, one that can separate and concentrate the compounds using a naturally-occurring process called foam frac­tion­a­tion. EPOC Enviro’s Surface Active Foam Frac­tion­a­tion® (SAFF) system is a mobile, ex-situ shipping container capable of reducing the equivalent of an Olympic-size swimming pool down to a single cup of PFAS concentrate. The technology has proven so promising that CDM Smith and EPOC are piloting this treatment technology throughout the U.S. It is the first deployment of its kind and holds incredible potential to treat very high concen­tra­tions of PFAS at source points like industrial manu­fac­tur­ing plants, fire training areas and landfills.  

How does it work?

Surface foam can occur naturally, like in the case of decomposing organic plant matter rising to an air-water interface. Or, it can be a sign of pollution. In Michigan, the Department of Environment, Great Lakes and Energy fields enough inquiries related to clusters of potentially toxic foam that it added a “Foam Sighting Form” to its website. In areas where high levels of the compounds have entered local waterways, that foam is potentially concen­trated PFAS. 

This happens because all PFAS share a strange chemistry: a hydrophilic head (highly soluble) and a hydrophobic tail (water repellent). When PFAS collide with pockets of air underwater, the air bubble traps the tail, and the molecules rise to the surface to collect as foam. 

Several years ago, recognizing that nature had already perfected its own way of separating and concen­trat­ing PFAS molecules, scientists at CDM Smith’s Research and Testing Laboratory theorized that foam frac­tion­a­tion could be employed as a field-ready PFAS separation technology. For it to work, they would need to find an efficient method of skimming off and collecting the foam. CDM Smith found a promising partner in EPOC Enviro, known elsewhere around the world as OPEC Systems, who was developing a three-stage foam frac­tion­a­tion system of their own.

SAFF® produces a relatively low volume of PFAS concentrate, which is further polished by a low-pressure evaporation process that distills and reduces the effluent into a PFAS hyper-concentrate. For every megaliter (264,172 gallons) of water treated, the SAFF® system produces only a few quarts of hyper-concentrate thereby dramat­i­cally reducing overall disposal costs.

What’s next?

CDM Smith recently announced that SAFF had arrived in North America for the first time, on its way to one of several scheduled pilot project sites. The unit is now up and running, generating flocs of foam. Early reports have been positive, and CDM Smith will continue piloting SAFF in a range of settings. 

To find the best use for this treatment train, consider the benefits: 

Sustainable: No chemical addition needed 

Destruction-ready: Generates smaller effluent, less energy needed to destroy 

Economical: Low price-per-gallon treated 

Powerful: Efficiently treats high concen­tra­tions of PFAS

For these reasons, CDM Smith researchers are validating foam frac­tion­a­tion as a PFAS treatment option for wastewater reclamation facilities, in-situ groundwater sites, landfills and inves­ti­ga­tion-derived waste, among others. 

Foam frac­tion­a­tion effec­tive­ness can vary—depending on the rate of aeration, water quality, PFAS chain lengths, bubble density and sizes, foam collection effec­tive­ness and the targeted concen­tra­tion factor to reduce the foam volume.