Recent work by scientists at the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences (CAS) has resulted in a novel method which achieves complete mineralization and fluoride immobilization in PFOA, a commonly found PFAS compound.
The research, published in the Journal of the American Chemical Society, achieves the mineralization and immobilization by using a unique microcloud which has been enriched with wollastonite-bearing microdroplets. Thanks to the microdroplets prioritization of defluorination over C-C scission in perfluoroalkyl chains, the method achieves effective mineralization with limited detectable anionic PFAS byproducts. Additionally, thanks to the formation of CaF2-SiO2 interfacial structures, fluoride immobilization is achieved with negligible leaching.
Using their novel method the researchers were able to reduce PFOA contamination to well below the 4ppt limit set by the US EPA while producing well under 500ppt of anionic PFAS byproducts, the limit currently proposed by the European Environment Agency.
"Our study indicates that beyond potential applications of microdroplets in practical water treatment under ambient conditions, microdroplets from clouds and sea spray may possess a significant yet overlooked, self-cleaning capacity for PFAS pollutants on a global scale," said Prof. Wang Feng.