What is PFAS?
PFAS stands for Per- and Poly-Fluoroalkyl Substances, a group of more than 7000 widely used synthetic, man-made chemicals. They all contain carbon-fluorine bonds, which are one of the strongest chemical bonds in organic chemistry, they are not easy-degradable and remain in the environment, thus widely considered as “forever chemicals”. They accumulate in animal and human tissue and are toxic at low levels of bioaccumulation, causing endocrine nervous system and several other health problems.
In the US, there are currently no enforceable federal drinking water standards for any PFAS compounds, however state legislation and regulations pertaining to PFAS have increased in recent years in response to cases of contamination across the country. To date, 11 states have set their own drinking water standards through a combination of legislative, regulatory, and advisory body actions.
In late 2021, the EPA laid out a new PFAS Strategic Roadmap in which it slated the proposal of new federal drinking water standards (NPDWR – National Primary Drinking Water Regulations) for two PFAS chemicals – PFOA and PFOS, the Strategic Roadmap was released on March 2023 and expected to be finalized on January 2024.
EPA has identified the following as best available technologies:
- Granular activated carbon (GAC)
- Anion Exchange (AIX)
- Nanofiltration (NF)
- Reverse Osmosis (RO)
In Europe, PFOS & PFOA were phased out and now restricted under the EU POP (Persistent Organic Pollutants) regulations thus, manufacture, import and export are largely prohibited. In late 2020 amended was made in the EU Quality of Water Directive minimizing PFOS & PFOA levels in drinking water, according to the Directive each state member must enact regulation that will entry into force in 2026.
PFAS Removal Technologies
PFAS are found in rivers, lakes, and reservoirs all over the world. The most common types of PFAS detected are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), which have already been phased out of production in Europe and the United States. The highest levels of PFAS contamination are found in industrial and urban areas, as well as in areas with a high population density.
PFAS projects include:
Cleanup of municipal wastewater treatment water, prior to discharge (recycling back into the environment).
Cleanup of industrial wastewater prior to being discharged into a receiving body.
Treatment of municipal drinking water that has been contaminated with PFAS.
At IDE we offer a complete range of removal solutions:
Carbon adsorption – GAC
Specialty anion ion exchange resin
Reverse osmosis or nanofiltration
Other typical water purification techniques, include biodegradation, micron filtration, sand filtration, ultrafiltration, coagulation, flocculation, clarification, and oxidation by ultraviolet light, hypochlorite, chlorine dioxide, chloramine, ozone, or permanganate, are not able to effectively remove PFAS from water/wastewater.
Granular Activated Carbon (GAC):
GAC can remove low concentrations (ng/L) of PFAS from drinking water. The GAC efficiently treats longer PFAS chains and less efficient for treating the short-chain PFAS. The presence of other organic matters may reduce the GAC adsorption efficiency. The carbon media may be recycled for use elsewhere after the PFAS is burned off.
Ion-Exchanger (IX):
An ion-exchanger is efficient for removal of anionic and long-chain PFAS at low concentrations (ng/L). Adsorption capacity is higher compared to GAC and the adsorption kinetics is faster. It is less efficient for water containing organic or inorganic matter and is limited in removal of short-chain PFAS. The media is typically used once and incinerated but the resin lasts a long time, so the economics are attractive.
Membrane (RO/NF):
Membrane technology is effective for short-chain as well as long-chain PFAS. Other organic and inorganic impurities are also removed. High removal rate and time-efficiency לנסח מחדש. The energy requirement for membrane wastewater treatment is high compared to adsorption or ion exchange resin.
