Adsorption of perfluorooctane sulfonate (n-PFOS) onto non ion-exchange polymers and granular activated carbon: Batch and column test

Perfluorooctane sulfonate (n-PFOS) is the latest chemical categorized as persistence organic pollutants (POPs). n-PFOS appears in the environmental water and tap water, which mainly comes from industrial wastewater. The process of adsorption has been identified as an effective technique to eliminate n-PFOS in water. We studied the sorption kinetics and sorption isotherms of n-PFOS for the non ion-exchange filter materials of Dow V493, Dow L493, Amb XAD and Filtrasorb 400 (GAC) by batch experiments. And the same materials were checked with a column experiment. Amb XAD 4 was recognized as the best candidate among the four filter materials tested. Dow V493 and Dow L493 showed higher Freundlich constant and lower kinetic constant whereas GAC showed highest kinetic constant and lowest Freundlich constant suggesting comparatively less performance at real application. This fact was proved by the column test results by giving the best performance by Amb XAD4. It was noticed in the column test that Amb XAD 4 removed 99.99% PFOS up to 23,000 bed volumes pass through with the condition of 10 μg/L inflow concentration and flow rate of 15 mL/min (0.75 bed volumes/min). In the recovery experiment, ion-exchange polymers showed a high possibility to regenerate by an organic solvent.