A comparative study of adsorption of perfluorooctane sulfonate (PFOS) onto granular activated carbon, ion-exchange polymers and non-ion-exchange polymers

Perfluorooctane sulfonate (PFOS) is the latest chemical categorized as persistent organic pollutants (POPS) PFOS appears in the environmental water and tap water in ng L(-1) level. The process of adsorption has been identified as an effective technique to eliminate PFOS in water. Three non-ion-exchange polymers (DowV493. DowL493 and AmbXAD4), two ion-exchange polymers (DowMarathonA and AmblRA400) and one granular activated carbon (GAC) (Filtersorb400) were tested with regard to their sorption kinetics and isotherms at low PFOS concentrations (100-1000 ng L-1 equilibrium concentrations) The sorption capacities at 1 jig L-1 equilibrium concentration decreased in the following order Ion-exchange polymers > non-ion-exchange polymers > GAC. but at further low equilibrium concentration (100 rig L-1) non-ion-exchange polymers showed higher adsorption capacity than other adsorbents In the case of sorption kinetics. GAC and ion-exchange polymers reached the equilibrium concentration within 4 h and AmbXAD4 within 10 h DowV493 and DowL493 took more than 80 h to reach equilibrium concentration AmbIRA400 was identified as the best filter material to eliminate PFOS at equilibrium concentration >1000 ng L. Considering both adsorption isotherms and adsorption kinetics. AmbXAD4 and DowMarathonA were recommended to eliminate PFOS at ng L(-1) equilibrium concentration. (C) 2010 Elsevier Ltd All rights reserved