Treatment technologies for aqueous perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA): A critical review with an emphasis on field testing

• Review of existing technologies for the treatment of PFOS/PFOA contaminated water.
• Activated carbon has been the most widely used adsorbent for PFOS/PFOA removal.
• We summarised adsorption capacities of available and recently developed adsorbents.
• Tool for remediators and researchers.

Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are used in fire-fighting foams but this is now being questioned because concerns are growing about their toxicity and impacts on the environment. Past use has resulted in their widespread accumulation in water sources, sediments and biota. They may pose risks to human health and the environment. Several technologies have been tested for removing PFOS and PFOA from water but most have only been developed at laboratory scale. This paper provides a critical review of existing methods for removing PFOS and PFOA from wastewaters with an emphasis on identifying processes that show promise for the development of practical industrial-scale remediation technologies. It is concluded that among the remediation technologies cited in the literature, removal by activated carbon has been the most widely used, with several successful field tests being reported. However, a number of limitations to the use of activated carbon exist, such as being ineffective at removing PFOA and other PFCs. Other adsorbents that have the potential to treat aqueous PFOS and PFOA include organo-clays, clay minerals and carbon nanotubes.