Controlling saturation to improve per- and polyfluoroalkyl substance (PFAS) removal in biochar-amended stormwater bioretention systems

When stormwater biofilters are not saturated, per- and polyfluoroalkyl substances (PFASs) sorb to the air–water interface. The design of black carbon-amended stormwater biofilters for PFAS removal can be improved by preventing saturation.