How Green Chemistry can Solve the Forever Problem

Abstract

Per- and polyfluoroalkyl substances (PFAS) are a class of thousands of man-made chemicals with a partially or fully fluorinated carbon chain. Developed in 1940s, these amphiphilic compounds, with a hydrophilic head and a hydrophobic tail, have unique properties to repel oil, water, and grease and have excellent chemical, biological, and thermal stability due to strong C-F bond (105.4 kcal/mol).1 Thus, they have well-known uses in a variety of consumer and industrial products namely, outdoor gear, food packaging, personal care products, home furnishings, electronics, surface coatings and firefighting foams.2 Due to their ubiquitous use and persistence, these highly mobile3 forever chemicals have been detected across environmental media and even in indoor spaces,4 food,5 and humans6 via various pathways. Owing to their health and environmental concerns, and analytical improvements, there has been increased attention towards regulating, remediating, phasing-out, and substituting these chemicals of high concern (Figure 1). However, the replacement of legacy long chain PFAS compounds with structurally similar shorter and ultrashort chain PFAS have resulted in regrettable substitutes which are highly mobile, more hydrophilic, not well regulated, and difficult to remove due to low adsorption potential.7 Our aim is to synthesize and assess the effectiveness of sorbents that are cheap, scalable, and have the potential to adsorb problematic short chain PFAS via electrostatic interactions. This presentation will highlight various facets of PFAS to create awareness and discuss the effectiveness of our cationic polymer which has been grafted onto natural fibres for remediating problematic PFAS from water. Our study will include benchmarking our sorbent against existing commercial options, with a particular focus on assessing its behaviour concerning pH sensitivity, kinetics, adsorption properties and testing in natural water samples to better understand its sorbent behaviour under different conditions. The current state of knowledge on emergence, distribution, remediation, and safe-by-design replacements to PFAS will help raise awareness for this next global public health emergency.