In June of 2022, the EPA announced a huge pot of money available for Emerging Contaminants in small and disadvantaged communities — $5 billion, to be exact. The grants that are available to states through this fund are meant to address the health problem in drinking water known as PFAS contamination.
Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are organic and inorganic compounds that contain carbon-fluorine chains. But what makes them so special? Their carbon-fluorine bonds are extremely strong. This means that PFAS compounds don’t degrade easily from environmental factors, including temperature and infection from microbes. This gave them the nickname “forever chemicals”.
Because they don’t easily break down, PFAS substances are used in a wide variety of ways, including plastic manufacturing and medical applications. We can also find PFAS substances in our own homes in food-wrapping materials, non-stick cookware, and firefighting foam.
However, their long shelf-life also makes them difficult to deal with. They are toxic and can build up high concentrations in animals and humans due to their presence in most everyday items. Their chemical properties even make it hard to treat and detect in water. This forces water authorities to resort to unique remediation methods. In this blog, we will be taking a closer look at those remediation methods.
3 Treatment Solutions – Old (Removal) vs. New (Degradation)
1. Granular Activated Carbon
While PFAS treatment is difficult due to their chemical properties, experts have innovated unique solutions to remediate PFAS contaminations. One of the most effective treatment methods that remove PFAS from water is granular activated carbon (GAC). How does it work? GAC is made from raw materials with high carbon content that has been treated with heat to expand its surface area. This allows them to easily bind a lot of substances to itself, making it an ideal and cost-effective option for PFAS removal.
For example, the Town of New Windsor, New York detected PFAS contamination in their wells in 2019, causing them to partner with Aztech Environmental Technologies to develop a solution. Due to the reduced costs and better feasibility, the Town of New Windsor implemented a GAC treatment under the recommendation from Aztech. They installed six 20,000-pound carbon units that treated water at a rate of 1,500 gallons per minute. Shortly after, by 2020, the town’s PFAS contamination became undetectable, proving that the use of GAC is a cost-effective way to treat PFAS pollution.
2. Ion Exchange Resins
Another innovative and effective solution to PFAS contamination is the use of ion exchange (IX) resins. When substances and pollutants such as PFAS dilute or dissolve in water, they release electrically charged particles called ions. What does this have to do with IX resins? IX resins help exchange ions in the water, absorbing pollutant ions and releasing beneficial ions.
This occurs because the resins contain ions that have the opposite charge of the pollutant ions. Since opposite charges attract, the resins are able to easily bind with the pollutants and release beneficial ions into the water. Due to these properties, IX resins allow for fast results, short- and long-term applications, quick installations, and minimal maintenance.
In fact, the Air Force Civil Engineering Center (AFCEC) detected groundwater PFAS contamination in a former air force base in New Hampshire that exceeded US EPA thresholds. To remediate this issue, the AFCEC used a regenerable IX resin system due to its low life cycle costs. As a result, the IX resin system was able to reduce 99.9 percent of the contamination, allowing the PFAS levels to become undetectable and compliant under US EPA regulations.
3. Electron Beam
A different, more technical solution has been gaining popularity and potential to be applied on a large scale as well. Previously, GAC and IX resins have been shown to successfully separate PFAS from the water. So why develop another solution? Because they only separate PFAS from water, GAC and IX methods create residual waste. This further begs the question of how to dispose of the waste. Here is where the electron beam (e-beam) addresses those issues. It has been shown to effectively degrade particles that don’t naturally biodegrade. And because it directly breaks down PFAS, it doesn’t create any residual waste.
But how does the e-beam achieve this? High energy beams made of negatively-charged particles called electrons are fired at the water. These beams break the strong chemical bonds of PFAS particles in the water, allowing them to decompose.
If e-beams have been extremely successful and effective, why haven’t water authorities used them more often? E-beams have largely been avoided due to high capital and operating costs stemming from inefficient power supplies. However, advancements in technology have allowed for improvements in power supplied, energy efficiency, and cost reduction. With these new enhancements, PFAS remediation and destruction could become more possible on a larger scale.
While PFAS contamination continues to be an important issue in water treatment, many viable and cost-effective solutions can be implemented and developed to address them. From the case studies previously discussed, it is clear that PFAS remediation is possible in a short amount of time. However, to maximize their results, water systems must also consider different variables that could affect the effectiveness of such solutions. These factors include cost, treatment system design, and technological capacity. While PFAS issues persist, advancements in technology and human innovation can continue to make way for more cost-efficient and unique solutions that would allow more and more communities to have access to clean and safe water.
To learn more about EPA grant funding to states to address PFAS contamination in drinking water, visit: https://www.epa.gov/dwcapacity/emerging-contaminants-ec-small-or-disadvantaged-communities-grant-sdc#applicants1
- “Ion Exchange (IX),” DuPont Water Solutions, accessed January 9, 2023, https://www.dupont.com/water/technologies/ion-exchange-ix.html
- Fina III, Fil L. “Here’s How One Community Made Quick Work of PFAS: A New York town removes PFAS from its drinking water supply in four months using a granular activated carbon treatment system.” Fast-Track Fix, August, 2020. Treatment Plan Operation. https://www.tpomag.com/editorial/2020/08/heres-how-one-community-made-quick-work-of-pfas
- Fina III, Fil. “How one New York town restored drinking water production in just four months.” April 17, 2020. American City & County. https://www.americancityandcounty.com/2020/04/17/how-one-new-york-town-restored-drinking-water-production-in-just-four-months/
- “15 Case Studies,” Interstate Technology Regulatory Council, last modified June, 2022, https://pfas-1.itrcweb.org/15-case-studies/#15_2
- Li, Cang, “Ion exchange resins and their applications,” Water Technology Industrial Water Management, November 1, 2015, https://www.watertechonline.com/directory/article/15549544/ion-exchange-resins-and-their-applications
- Londhe, Kaushik, Cheng-Shiuan Lee, Yi Zhang, Slavica Grdanovska, Thomas Kroc, Charlie A. Cooper, and Arjun K. Venkatesan. “Energy evaluation of electron beam treatment of perfluoroalkyl substances in water: A critical review.” ACS ES&T Engineering 1, no. 5 (2021): 827-841.
- “Ion Exchange,” Pure Aqua, Inc., accessed January 9, 2023. https://pureaqua.com/ion-exchange-water-treatment-systems/
- “What Is Ion Exchange Resin and How Does It Work?,” SAMCO, November 28, 2017, https://samcotech.com/ion-exchange-resin-work-process/
- Tuser, Cristina. “What is Granular Activated Carbon (GAC)?” Wastewater Digest, January 3, 2022, https://www.wwdmag.com/editorial-topical/what-is-articles/article/10939799/what-is-granular-activated-carbon-gac