Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals that includes PFOA, PFOS, GenX, and others that were developed in the 1940s. They are also known as “forever chemicals” because they do not break down and accumulate over time in both the environment and in the human body.
Where do PFAS come from?
They have been used in the production of Teflon and fluoropolymers that coat products to protect against heat, corrosion, and other chemicals. They were also used in the 1960s to develop a film-forming foam used to fight petroleum fires at oil refineries, airfields, and other similar locations.
Where can you find PFAS?
PFAS can be found in the drinking water of more than 110 million people. Studies indicate that exposure can lead to reproductive and developmental harm, liver and kidney, and immunological effects in laboratory animals. Both chemicals have caused tumors in animal studies. The most consistent findings from human studies are cancer, thyroid hormone disruption, increased cholesterol levels, low infant birth weights, and effects on the immune system.
How do you remove them?
PFAS removal is resistant to many, if not most, water treatment processes. Some removal processes can even increase their concentrations. Additionally, processes such as powdered activated carbon, can effectively remove older PFASs, but are less effective with newer PFASs.
But the good news, according to the EPA, is that these chemicals can be removed by up to 99.9 percent (EPA established health maximum level of 70 ppt) by processes such as granular activated carbon, membrane separation, ion exchange, and powdered activated carbon.
There are two forms of PFAS: short-chained and long-chained. Short-chain compound shave fewer carbons. Long-chain compounds are either sulfonic-based, with six or more carbons in the polymer chain, or carboxylic acid-based with 8 or more carbons in the polymer chain. There are different removal methods for each.
Granular Activated Carbon (GAC) is less efficient and more expensive than single-use resins. Reverse osmosis, foam fractionation and regenerable ion exchange resins create PFAS-laden waste streams that must be treated again with a single-use PFAS-selective resin.
Certain manufacturers have developed special ion exchange resins with high selectivity for poly- and perfluoroalkyl substances. For instance, ResinTech’s SIR-110-HP is a chloride form perchlorate, nitrate, and PFAS selective gel strong base anion resin with WQA Gold Seal Certification.
Water treated with these types of resins 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 they are high-capacity, single-use resins, 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.
For more information about how to treat PFO/PFAS, contact us today!