Removal of Perfluorooctane and Perfluorobutane Sulfonate from Water via Carbon Adsorption and Ion Exchange

Abstract

This research investigated the removal of perfluorooctane sulfonate (PFOS) and perfluorobutane sulfonate (PFBS) from water by Filtrasorb®400 granular activated carbon (GAC) and Amberlite®IRA-458 ion exchange resin. Kinetic experiments showed that the time required for the uptake equilibrium was ∼50 hours for the GAC and ∼10 hours for the resin. Sorption isotherms showed that PFOS and PFBS uptake was endothermic and was promoted by hydrophobic effects on the GAC, and by a combination of hydrophobic adsorption and ion exchange on the resin. The aqueous solubility of PFOS was highly dependent on the ionic composition of the solution. PFOS and PFBS uptake by the resin was hysteretic and nearly irreversible using conventional regeneration methods.