Removal of PFAS from groundwater by ozone nanobubbles

Per- and poly-fluoroalkyl substances (PFAS) are a family of manufactured chemicals that have been extensively used for aqueous film-forming foam (AFFF). They are highly water-soluble, persistent, and ubiquitous with adverse health effects. Removal of PFAS is important for water treatment and reuse. To eliminate PFAS, we have fabricated a new nanobubble generator to create ozone nanobubbles (ONB) and use it to degrade PFAS in spiked water and in authentic groundwater. Reductive and oxidative species, namely O2.- and OH. free radicals, are concurrently created that enable alternate reductive and oxidative attacks at the C-F bonds of PFAS, leading to chain shortenings and eventual mineralization of PFAS. Results thus far showed 98% PFAS removal in 90 min from a groundwater containing an initial concentration of 90 ppt. In its final form, this paper will present PFAS degradation results and identified products under various treatment conditions including contact time, ozonation rate, and others.