University of Illinois researchers unveil a pioneering electrochemical method to remove and destroy PFAS from water, offering a solution for the semiconductor industry’s rising pollution concerns.
In a groundbreaking achievement, researchers at the University of Illinois Urbana-Champaign have developed a novel electrochemical strategy capable of capturing, concentrating and destroying diverse mixtures of per- and polyfluoroalkyl substances (PFAS) from water in a single, efficient process. This advancement is particularly relevant for the semiconductor industry, which faces significant PFAS pollution issues as it expands.
The study, led by Xiao Su, a professor of chemical and biomolecular engineering, addresses the limitations of previous methods. While earlier studies demonstrated that electrochemically driven adsorption, or electrosorption, could remove longer-chain PFAS, they struggled with ultra-short-chain molecules due to their distinct chemical characteristics.
“We decided upon redox electrodialysis because the very short-chain PFAS behave a lot like salt ions in water,” Su said in a news release. “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.”
Published in the journal Nature Communications, this study marks the first successful integration of redox electrodialysis with electrosorption to handle the full spectrum of PFAS sizes.
The dual-function device not only removes ultra-short-chain PFAS by desalination but also filters out short- and long-chain PFAS using carbon electrodes, concentrating all the contaminants for easier destruction.
Addressing a significant hurdle, Su’s team developed an inexpensive nanofiltration membrane that resists fouling, an issue that plagued previous ion-exchange membranes. This innovation stems from their earlier work combining redox polymers with nanofiltration membranes to achieve energy-efficient desalination.
“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. “This process also concentrates all the PFAS, making them easier to destroy once captured.”
Employing electrochemical oxidation, the redox electrodialysis process ultimately converts captured PFAS into fluoride ions, effectively eliminating these persistent pollutants from the environment.
The implications of this technology are vast, particularly as semiconductor production is set to increase significantly in the coming years. This growth will likely bring more PFAS-related challenges, making sustainable production practices more crucial than ever.
“This work is very timely due to interest from the U.S. government, wastewater treatment facilities and the semiconductor industry,” added Su. “Semiconductor production is expected to rise over the coming years, and PFAS abatement for sustainable production will become a major issue moving forward.”