Per- and polyfluoroalkyl substances (PFAS), known for their environmental persistence, can contaminate water resources. A new study published in the Journal of Hazardous Materials reveals that a specific transport mechanism involving soil colloids is responsible for their unexpected presence in groundwater.
These mineral and organic particles, called colloids, can become mobile under the action of water in the soil. PFAS, which bind strongly to them, are then transported with these colloids, increasing their mobility and the risk of contamination to groundwater reserves and crops.
The research, conducted on soil monoliths collected from a former site contaminated by firefighting foams, allowed for the measurement of 39 PFAS concentrations before and after centrifugation. This approach distinguished between PFAS bound to colloids and those in solution, offering an unprecedented understanding of these pollutants' mobility.
These findings necessitate a reconsideration of current PFAS mobility models. They emphasize the importance of colloid mobilization and stability mechanisms for accurately predicting groundwater contamination risks and refining risk management strategies.
