Intra-event variations of organic micropollutants in highway runoff and a presedimentation-biofilter treatment facility

Occurrence, Concentration, and Distribution of 35 PFASs and Their Precursors Retained in 20 Stormwater Biofilters

“…Fate and transport of PFASs possessing a range of hydrophobic, hydrophilic, surfactant type, and surface active properties are more complex than many better-known OMPs in soil–water–air media . For instance, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and petroleum hydrocarbons, the main OMPs investigated in biofilter fate studies, show high hydrophobic adsorption to organic matter (OM), suspended solids (SS), sediments, and filter material, with their fate controlled by particle transport/retention mechanisms. ,,− PFAS molecules and precursors, however, are involved in both hydrophobic and electrostatic adsorption to soil/sediment/SS particles and air–water interfaces (AWI), a significant PFAS retention mechanism under unsaturated conditions. − PFASs, especially LC compounds, bind to OM through their hydrophobic head and to the media’s charged sites through their ionic functional head (either directly or indirectly via metal oxides) . The electrostatic sorption/desorption interactions depend on the functional head charge (i.e., anionic, cationic, or zwitterionic), soil material (sorbent type), soil cation exchange capacity, microbial population, DOC, and changes in solution/soil pH, cations (e.g., Na + and Ca 2+ ), and ionic strength. − In general, LC-PFASs are expected to be adsorbed to particles faster and thus removed by biofilters more efficiently relative to SC-PFASs .…”