PFOA and PFOS Breakdown in Experimental Sand, Laboratory-grade Water, Investigation-Derived Groundwater and Wastewater Effluent Samples at 50 kGy Electron Beam Dose

Abstract In recent years, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been recognized as widespread persistent organic pollutants and identified as a great concern to public health. Electron beam (eBeam) technology is a form of ionizing radiation that had been previously successful in mediating the breakdown of PFOA and PFOS. These studies report complete breakdown of PFOA and partial breakdown of PFOS in samples with high pH, nitrate content, alkalinity, and anoxic conditions when exposed to eBeam technology at a dose of 50 kilograys (kGy). In lab-spiked water and sand, the concentrations of PFOA were reduced by 87% and 86% respectively. PFOS was reduced by 16% in lab-spiked water and 28% in lab-spiked sand. In spiked IDW groundwater exposed to 50 kGy, PFOA and PFOS were reduced by 98% and 41% respectively. Groundwater samples were collected from a monitoring well at Randolph AFB in San Antonio, TX, USA. Similarly, PFOA was reduced by 94% and PFOS by 41% in spiked post-UV wastewater effluent collected at the Texas A&M water treatment plant in College Station, TX, USA. Although the aforementioned conditions facilitated the complete breakdown of PFOA, more optimization and higher doses will be needed to achieve the same in PFOS.