Deep inside the Sweeney Water Treatment Plant near the Cape Fear River, a pilot project is underway that may help lower costs for filtering out forever chemicals.
It’s an initiative of NC Pure, a collaborative project funded by the state government and organized by scientists at UNC Chapel Hill.
Orlando Coronell, Co-Director of the UNC Chapel Hill Department of Environmental Sciences and Engineering, said, "the resin that we are developing is an ion exchange resin. So it removes negative ions. But it is tailored so that he has a greater affinity for PFAS compared to the other negative ions in water.”
So far, the resins seem to work well in a lab, but they’re trying them out under real-world conditions at the water utility to confirm. The next step is all about making the resin reusable, unlike the Granular Activated Carbon it may replace. GAC needs to be superheated to be reusable, and up to 15% of the matter is destroyed in the process.
Regenerating this new resin will require a solvent that lifts the PFAS away, leaving it clean and ready for another round of filtration.
"So the real solution is to take the PFAS out of the water concentrated into a much smaller volume. And that's what we're trying to do with the novel sorbents. And then you can take that small volume of waste to a destruction technology," Coronell said.
The pilot project should have some preliminary data in the coming months, and if they can make it easy to regenerate on-site without losing any resin, it could prove to be much more fiscally sustainable than the GAC method, which requires shipping thousands of pounds of material offsite.
Editor's note: This article initially stated that up to 50% can be destroyed when it is superheated before reuse; the correct figure is 15%.
