PFAS removal performance of novel technologies for treatment of firefighting water and groundwater

Per- and polyfluoroalkyl substances (PFAS) are a group of widely used man-made organic chemical substances. PFAS have been used because of their particular physicochemical properties: most are stable at high temperatures, recalcitrant to chemical oxidation and biological degradation, and act as a surfactant. Many PFAS may also be bio-accumulative and toxic and there are concerns around their environmental effect. In this study several treatment technologies for PFAS removal were tested in the laboratory on both groundwater containing PFAS, and firefighting wastewater obtained from a firefighting training site where firefighting foam was applied. The treatment technologies assessed were performance of sorbents, coagulation/flocculation, nanofiltration, foam- and ozo fractionation technologies. In all cases the PFAS removal effectiveness was evaluated. Experiments showed that all sorbents were able to remove PFAS from both groundwater containing PFAS as well as firefighting wastewater, but the latter required sorbent dosages in g/L range. It was therefore concluded that groundwater containing PFAS can be treated with one of the tested sorbents directly, while for firefighting wastewater, typically has higher PFAS concentrations as well as other contaminants, a treatment train approach is likely to be more efficient.