Researchers have demonstrated that they can attract, capture, and destroy perfluoroalkyl and polyfluoroalkyl substances (PFAS), a group of federally regulated substances nicknamed “the forever chemicals” due to their persistence in the natural environment. Using a tunable copolymer electrode, the team captured and destroyed PFAS present in water using electrochemical reactions. The proof-of-concept study shows that copolymers can drive electrochemical environmental applications.
Exposure to PFAS has gained intense attention recently due to their widespread occurrence in natural bodies of water, contaminated soil, and drinking water. PFAS are typically present in low concentrations and devices or methods designed to remove them must be highly selective toward them over other compounds found in natural waters. PFAS are electrically charged, held together by highly stable bonds, and are water-resistant, making them difficult to destroy using traditional waste-disposal methods.
The team tuned a copolymer electrode to attract and adsorb PFAS from water. The process not only removes the dangerous contaminants but also destroys them simultaneously using electrochemical reactions at the opposite electrode, making the overall system highly energy efficient.
To evaluate the method, the team used various water samples that included municipal wastewater, all spiked with either a low or moderate concentration of PFAS. Within three hours of starting the electrochemical adsorption process in the lab, there was a 93 percent reduction of PFAS concentration in the low-concentration spiked samples and an 82.5 percent reduction with moderate-concentration spiked samples, which shows the system can be efficient for different contamination contexts such as in drinking water or even chemical spills.
The process combines the separation and reaction steps in one device, an example of process intensification, which is an important approach for addressing environmental concerns related to energy and water. The team plans to continue to work with various emerging contaminants including endocrine disruptors.