Column experiments to investigate the fate of per- and polyfluoroalkyl substances (PFASs) in the subsurface during soil stabilization with colloidal activated carbon

Remediation of sites contaminated with per- and polyfluoroalkyl substances (PFASs) is key to reduce the contamination of drinking water sources and subsequent human exposure. PFAS production and use is increasingly being restricted worldwide, however, legacy contamination plumes in soil and groundwater system are still posing a threat due to their persistence against degradation. One of the most widely studied soil remediation techniques for PFASs is stabilisation, which results in the long-term entrapment of the contaminants with the addition of fixation agents in the subsurface, aiming to prevent their leaching from soil to groundwater. In relation to this, the aim of this study was to identify the leaching behaviour of PFASs in a treatment scenario using activated carbon. Results have shown significantly increased sorption of PFASs in soil amended with activated carbons compared to untreated soil. Additionally, there was a positive correlation between the length of the perfluorocarbon chain and sorption efficiency. The study is a step towards increasing our understanding on the efficiency and longevity of stabilisation with activated carbons as a remediation strategy for PFAS-contaminated soils and groundwater.