Per- and poly-fluoroalkyl substances (PFAS) are a family of manufactured chemicals that have been extensively used for aqueous film-forming foam (AFFF). Their prevalence and partition in both the soil and groundwater presents a great concern for public health. To eliminate PFAS from soil, we have fabricated a new nanobubble generator and fed it air and ozone gas to create air nanobubbles (ANO) and ozone nanobubbles (ONB), respectively. With its abundant gas-liquid interface emulating surfactants, ANO is used as an extractant to remove PFAS from a column packed with PFAS-contaminated soil. ONB is then used to mineralize the extracted PFAS from water via alternate attacks on the PFAS by reductive superoxide and oxidative hydroxyl free radicals generated at the ONB interface, leading to chain shortenings and eventual mineralization of PFAS. The process allows the extractive water with ANO to be reused for further soil washing. Preliminary results on PFAS-impacted concrete debris showed 85% removal of total PFAS in 75 min from an initial concentration of 98 ng/g in the concrete debris. In its final form, this paper will present results of PFAS removal from soil under various treatment conditions including contact time, ozonation rate, and others.
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