High affinity cationic hydrophobic polymers for sequestration of PFAS from contaminated groundwater

Abstract

Poly and perfluoroalkyl substances (PFAS) represent a large family of organofluorine compounds that have been used in a variety of applications since the 1940s. Their applications include paints, water-resistant fabrics, fire-fighting foams, non-stick cookware, and food packing. The high stability presented by these compounds is a key factor for many possible applications, but it also means that they are very persistent in the environment, being classified as "forever chemicals". In recent years, these compounds have been reported as ubiquitous in the environment. Since they are highly persistent, there is a rising concern about the possible hazards to ecosystems and humans caused by exposure to PFAS. The U.S. Environmental Protection Agency (EPA) Health Advisory of 2022 indicated an acceptable limit of 0.004 and 0.02 ng L-1 of PFOA and PFOS in drinking water, respectively. Many wells from the Central Tucson Basis well field, used for the city supply, were recently shut down due to unsafe levels of PFAS. The city's aquifer contamination is a result of the application of aqueous film-forming foams (AFF) by a Department of Defense facility. Nowadays, methods usually applied for the treatment of contaminated groundwater are expensive and energy-intensive, making the research for a viable alternative method for remediation of great importance. The goal of this research project is to study (i) the sportive properties of an array of 25 PFAS compounds in the presence of high-PFAS-affinity cationic colloidal polymers in saturated sand, and (ii) the capacity of this complex for the removal of PFAS from the contaminated groundwater. These bench-scale experiments are a key point for the development of an effective in-situ remedial technology for the treatment of the PFAS-contaminated aquifer. (AU)