A first-of-its-kind study from the University of Illinois Urbana-Champaign describes an electrochemical strategy to capture and destroy an array of PFAS molecules including ultra-short-chain PFAS.
While a previous U of I study outlined a method for electrochemical removal of PFAS from water, the method was ineffective against ultra-short-chain molecules because of their size and chemical property differences.
The new method, published in Nature Communications, combines redox electrodialysis with the previously developed electrosorption method into a single device that can be used to capture and destroy PFAS across the entire size spectrum.
"We decided upon redox electrodialysis because the very short-chain PFAS behave a lot like salt ions in water," said Xiao Su, a chemical and biomolecular engineering professor at the University of Illinois. "The challenge was to produce an efficient, effective electrodialysis system to capture the ultra-short-chain PFAS, have it work in tandem with the electrosorption process for the longer-chain PFAS, destroy them with electrochemical oxidation, and make it happen within a single device."
"After experimenting with a variety of device configurations, we finally settled on a system that desalinates the PFAS-contaminated water to remove the ultra-short-chain molecules, then at the same time, carbon electrodes remove the remaining short- and long-chain molecules," Su added.
To address wastewater contamination, the team intends to scale up the process and incorporate the system into on-site wastewater streams. "This work is very timely due to interest from the U.S. government, wastewater treatment facilities and the semiconductor industry," Su said. "Semiconductor production is expected to rise over the coming years, and PFAS abatement for sustainable production will become a major issue moving forward."