Green sorption media for the removal of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) from water

Adsorption as a remediation technology for short-chain per- and polyfluoroalkyl substances (PFAS) from water – a critical review

“…They have been tested for their removal capacity of PFOS and PFOA, with reported removal efficiencies up to 46% for PFOS because of the hydrophobic interactions of PFAS with sand, in addition to their electrostatic interactions with clay and iron. 111 Many other engineered materials have been used as sorbents. For example, mesoporous cetyltrimethylammonium bromide (CTAB)-functionalized magnetic microspheres (mesoporous Fe 3 O 4 @SiO 2 @CTAB-SiO 2 ) were fabricated and tested for their adsorption capacity for trace amounts of PFOS in acidic conditions.…”

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

“…To date, PFAS studies on soil/sediments have mostly focused on agricultural soils impacted by contaminated wastewater treatment biosolids or surface soils near fluorochemical manufacturing facilities, along with a few on the stormwater sediments of sewers, ponds, and gully pots. ,− However, no study has investigated PFASs and precursors in the forebay and filter material of mature stormwater biofilters in urban areas. Although some lab-scale experiments reported unpromising PFAS adsorption by conventional soil media for highly contaminated groundwater/soil, ,− a critical review argued that PFAS sorption behaviors are more complex than can be described by a single soil/sediment property (e.g., soil organic carbon–water partitioning coefficient, K OC , the only parameter considered in most studies); instead, combination of several physio-chemical and kinetic factors (e.g., OM, pH, clay content, index cations, ionic strength, cocontaminants, contact time, and unsaturated/saturated flow conditions) may have significant increasing effects on PFAS sorption. ,,, There is particularly a critical knowledge gap regarding the fate of PFASs in biofiltration systems under field conditions, wherein the following numerous factors and their variations may also play a role: catchment land use and area, biofilter’s design characteristics such as surface hydraulic loading rate, media depth, age, initial and accumulated OM and fine particle content in the filter material, surface chemistry of soil particles, number of inlets, existence/type of forebay (pretreatment), and stormwater chemistry (e.g., TSS, pH, OM, and competing ions and OMPs) . Field data on the type and concentration of PFASs and precursors accumulated in mature (around 10 years old) stormwater biofilter facilities will deepen the current knowledge about (1) the actual role of biofiltration systems in the sorption and fate of PFASs, (2) the potential remobilization and transformation of PFASs in biofilters, (3) design modifications for targeted PFAS removals in the future, (4) the long-term operation of biofilters, including maintenance/disposal needs and measures throughout their lifecycle, and (5) the health risk assessment associated with accumulated PFASs.…”

A Critical Review on PFAS Removal from Water: Removal Mechanism and Future Challenges

“…Per-and polyfluoroalkyl substances (PFAS) are man-made fluorine-containing organic compounds exhibiting distinctive physiochemical characteristics due to the strong carbon and fluorine bonding (C-F) [1,2]. PFAS are comprised of hydrophobic and oleophobic carbon chains in which the hydrogen can be completely or partly substituted with fluorine atoms [3,4].…”