Sandia team works to develop a filtration system to remove PFAS from water

May 16, 2023

Craig Fritz/Sandia National Laboratories

Ryan Davis, left, and Andrew Knight simulate working at Sandia National Laboratories on the problem of PFAS contamination. Photo by Craig Fritz

A team from Sandia National Laboratories is working on a filtration system that will remove PFAS chemicals from water.

"What's unique about (PFAS chemicals) is that they have a carbon fluorine bond, and that carbon fluorine bond is very strong. So not many things readily break it down," Andrew Knight, a Sandia chemist, said in an interview with NM Political Report.

This strong bond has earned PFAS the nickname "forever chemicals."

In recent years, the prevalence of PFAS chemicals has received increased attention as more is learned about the potential health impacts of the substances.

One of the ways that people can ingest PFAS is through drinking water.

That's where Sandia's team hopes to cut out exposure by designing materials that will remove the PFAS from the water.

Knight and Ryan Davis, a materials science specialist with a background in environmental chemistry, have teamed up in search of the solution and have seen promising results.

"In the past couple of years, we’ve been working to identify strategies to focus on PFAS remediation," Knight said.

The material Knight and Davis are working with is similar to one that Knight investigated while in graduate school. He said when he was in graduate school he was involved in research looking at using the material to separate and attract uranium.

Knight said through conversations and reviewing of literature, it appeared that the material could have characteristics that would allow it to bind to PFAS chemicals. This would allow it to be used in a filtration system, either on a small scale such as in households or at a larger scale like water treatment facilities.

"We have a material that has been around and has been effective for other applications and seemed like it could be useful for this one as well," he said.

Knight and Davis received $100,000 in funding recently from the Sandia Technology Maturation Program to build the data to show how well the materials work.

Knight said that funding could also help them learn about what can be done to make it more effective.

Davis said he was surprised by how efficient the materials were in the preliminary study.

As he was doing the experiment to see what the capacity was—or how much PFAS the material could contain—he said he kept adding more and more into the solution.

"All the PFAS got sucked up," he said. "I was shocked by how much a small amount of this material could hold in terms of sucking out the PFAS out of the water."

But one area that still needs to be investigated is how to properly dispose of the material after it has sucked up the PFAS from the water.

"That's a critical question in determining how this can be effective commercially," Knight said.

Commercial water filters, such as Brita filters, can be disposed of in trash in regular landfills.

While Sandia does the research to develop the technology, ultimately the lab will need to partner with a company that is interested in taking it to the commercial market.

Knight said exploring what can be done to dispose of materials containing PFAS is an important next step in the process.

Knight said another area that is being researched is how to degrade PFAS to a form that is not harmful to human health and the environment.

All of this is important because new studies are being released regularly documenting the dangers of PFAS, including increased risk of premature birth, higher cholesterol, weakened immune systems, liver problems and cancer.

A study released this week in the journal Environmental Health Perspectives found that when pregnant people are exposed to PFAS, their child is more likely to experience obesity.

Sandia is not alone in looking for solutions to the PFAS problem. University of California at Riverside published a study in May looking at the potential use of two species of bacteria to clean up PFAS. UC Riverside is also looking at using hydrogen and ultraviolet light to remove PFAS from water. Another team at the University of Illinois Urbana-Champaign has been looking at using electrodes to attract, capture and destroy certain PFAS chemicals.

Knight said that one thing unique about the materials Sandia is using in the filtration system is that they are relatively simple, but allows for a little bit increased specificity and more capacity than other conventional methods such as granulated activated carbon or ion exchange.

He said it could be scaled to meet needs and could have a lower cost compared to some other methods that are being explored.

"It's really trying to find this middle ground of something that's very effective, but also something that can be readily deployed," he said.

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