Poly- and perfluorinated alkyl substances (PFAS)
PFAS represent a large family of organic compounds that are widely used as processing additives during fluoropolymer production and as surfactants in consumer applications (e.g., surface coatings for textiles, furniture, and paper products) over the past seven decades.
Due to the persistent and bioaccumulative nature of long-chain PFAS, manufacturers has begun adopting short-chain and ultra-short chain PFAS and other fluorinated alternatives (e.g., perfluoropolyethers) for commercial production.
I have recently published a critical review paper that focused on ultra short- and short-chain PFAS to highlight the current studies involving the removal of ultra-short and short-chain PFAS and identified the future research needs.
Current technological advances suggest that amine-containing sorbents can provide alternative solutions to PFAS control in the treatment of municipal water and wastewater at relatively low PFAS concentrations.
I have provided critical analysis of the development and application of amine-containing sorbents for PFAS removal in ES&T Letters.
Poly(ethylenimine)-Functionalized Cellulose
This study in ES&T Letters reported on poly(ethylenimine)-functionalized cellulose microcrystals (PEI-f-CMC) that showed a near-instant and high removal of PFAS under concentrations relevant to their actual occurrence in the natural environment (i.e., <1000 ng/L). The selective removal efficiency of 22 PFAS from different classes (i.e., legacy carboxylic and sulfonated PFAS, emerging carboxylic and sulfonated PFAS, and PFAS-precursors) using PEI-f-CMC was confirmed in lake water as well as solutions codosed with two additional types of natural organic matter. The performance of PEI-f-CMC was maintained in eight consecutive adsorption/regeneration cycles to remove PFAS. The PEI-f-CMC with its unique fast kinetics and high adsorption activity toward PFAS exhibits a great potential for being a promising alternative adsorbent for PFAS control.
Cationic Hydrogel
This study in Water Research showed the selective removal of 16 PFAS from different classes using DMAPAA-Q polymer from surface waters and treated wastewater. This work was among the first materials to demonstrate high adsorption of short- and long-chain legacy and emerging PFAS under environmentally relevant concentrations.