Per- and polyfluoroalkyl substances (PFASs), highly fluorinated aliphatic compounds used in various manufacturing industries, pose serious environmental concern due to their high resistance against environmental degradation processes. Perfluorooctane sulfonate (PFOS), one of the mostly used PFASs, also has high persistence, toxicity, and bioaccumulation potential resulting in high environmental and human health risk. Although few conventional water treatment technologies (adsorption by activated carbon, ion exchange resin) have been found to remove PFOS from water, the recalcitrant nature of the contaminant has stimulated further research on developing advanced treatment techniques specifically tailored for PFOS removal. In this study, we employed a nanohybrid, reduced graphene oxide/iron (rGO-Fe) synthesized through co-precipitation method, in a treatment system to evaluate PFOS removal performance. The rGO-Fe nanohybrid possesses substantial adsorption capacity due to high surface area and reduction capacity due to presence of low oxidation state Fe NPs. Additionally, the nanohybrid can catalytically generate hydroxyl radical ('OH) in presence of hydrogen peroxide (H2O2) which has high oxidation potential. These synergistic attributes make rGO-Fe nanohybrid a potential candidate for the effective removal of PFOS. In our preliminary studies, the performance of rGO-Fe nanohybrid was evaluated in two different setups. In first one, only nanohybrid was used where adsorption and reduction was the governing removal mechanism. For second setup, H2O2 was added which enabled further oxidation through formation of 'OH radical. Preliminary results suggest both of the setup exhibited high PFOS removal (over 90%) from aqueous solution (500 ppb) within first two hours. Further studies are ongoing to delineate the governing removal mechanisms and degradation product to optimize the performance of the rGO-Fe nanohybrid for PFOS removal.

Removal of perfluorooctane sulfonate (PFOS) from aqueous solution by reduced graphene oxide-iron nanohybrid

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.