Case Studies

What are PFAS?

Per- and polyfluoroalkyl substances (PFAS), also known as “forever chemicals,” are a group of man-made chemicals that includes PFOA, PFOS, GenX, and many other chemicals. PFAS' have been manufactured and used in a variety of industries around the globe, including in the United States since the 1940s. PFOA and PFOS have been the most extensively produced and studied of these chemicals. 

PFAS Health Risk
Both chemicals are very persistent in the environment and in the human body – meaning they don’t break down and they can accumulate over time. Exposure to PFAS can lead to adverse health outcomes in humans and are estimated to be in the drinking water of over 110 million people. Studies indicate that PFOA and PFOS can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals. Both chemicals have caused tumors in animal studies. The most consistent findings from human epidemiology studies are increased cholesterol levels among the exposed population as well as low infant birth weights, effects on the immune system, cancer, and thyroid hormone disruption.

Causes of PFAS in Water
PFOA and other PFASs have been used to produce Teflon and other fluoropolymers, which coat a wide range of products to protect against heat, chemicals, and corrosion. PFASs also have been used in aqueous film-forming foam, which was developed in the late 1960s to extinguish petroleum fires. Other sources of the contaminant are due to oil refineries and airfield or other location at which PFAS were used for firefighting.

Working with Communities & Government Officials
Purolite works with government representatives to provide information and solutions for local water supplies. Learn more about this process.

How to Remove PFAS From Water
According to the EPA’s Drinking Water Treatability Database, PFOA and PFOS can be removed by up to 99.9 percent by processes such as granular activated carbon, membrane separation, ion exchange, and powdered activated carbon. Aside from these technologies, PFAS removal is resistant to many, if not most, water treatment processes, while other technologies may increase their concentrations. Other processes, such as powdered activated carbon, are effective at removing older PFASs, but become less effective with newer PFASs, many of which are replacing the legacy PFASs.

Purolite's Ion Exchange Removal System
Purolite has designed, developed and commercially tested a special ion exchange resin with high selectivity for poly- and perfluoroalkyl substances.  Purofine PFA694E resin is a single-use proprietary, uniform particle size resin with the dual removal mechanisms of ion exchange and adsorption technology built into each bead for maximum uptake of PFAS. 

Purolite can meet and surpass the Health Advisory (HA) levels of 0.004 for PFOA (interim,) 0.02 for PFOS (interim,) 10 ppt for Gen X Chemicals (final,) and 2,000 ppt for PFBS issued in June 2022 by the US EPA.

Water treated with this resin will consistently achieve simultaneous removal of both short- and long-chain PFAS—including PFOA, PFOS, PFNA, PFHxA, PFHxS, PFHpA, PFBS, and PFBA— to non-detectable levels.

And because it is a high-capacity, single-use resin, there is no need for regenerant chemicals or methanol that can increase the corrosiveness of treated water. All exhausted resin gets incinerated, which completely breaks down the compounds, preventing re-introduction into the environment.

Sources: U.S. Environmental Protection Agency, Environmental Working Group, Food & Water Watch

The use of ion exchange resin to remove PFAS compounds is prevalent. Here are several case studies that highlight performance versus existing technology.

PFAS Removal | Potable Water Treatment
PFAS Removal CA | Potable Water Treatment

Perfluoroalkyles | Produits par application