Comparing conventional and emerging adsorbents for per‐ and polyfluoroalkyl substances: Kinetic, equilibrium, and column experiments
Scott A. Grieco, Joseph Chang, Elizabeth Y. Maio, Michael Hwang
Abstract
Abstract An expanding list of states have established enforceable drinking water regulations and/or advisories for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid. Additionally, many state regulations extend to shorter chain per‐ and polyfluoroalkyl substances (PFAS) compounds not currently addressed by the United States Environmental Protection Agency (USEPA). This current work presents batch equilibrium and continuous column (rapid small‐scale column test) bench‐scale experiments conducted on drinking water sources with similar PFAS composition but varying background water quality (namely dissolved organic carbon). Adsorption of PFOA was evaluated using activated carbon and an emerging modified clay as adsorbents. Both batch equilibrium and continuous column experiments demonstrated that modified clay has a greater adsorptive capacity and faster adsorption kinetics compared to activated carbon for both long‐ and short‐chain compounds studied, as represented by PFOA and perfluorobutanesulfonic acid, respectively.