title: Nanofiltration and granular activated carbon treatment of perfluoroalkyl acids.
abstract: Perfluoroalkyl acids (PFAAs) are of concern because of their persistence in the environment and the potential toxicological effects on humans exposed to PFAAs through a variety of possible exposure routes, including contaminated drinking water. This study evaluated the efficacy of nanofiltration (NF) and granular activated carbon (GAC) adsorption in removing a suite of PFAAs from water. Virgin flat-sheet NF membranes (NF270, Dow/Filmtec) were tested at permeate fluxes of 17-75 Lm(-2)h(-1) using deionized (DI) water and artificial groundwater. The effects of membrane fouling by humic acid on PFAA rejection were also tested under constant permeate flux conditions. Both virgin and fouled NF270 membranes demonstrated >93% removal for all PFAAs under all conditions tested. GAC efficacy was tested using rapid small-scale columns packed with Calgon Filtrasorb300 (F300) carbon and DI water with and without dissolved organic matter (DOM). DOM effects were also evaluated with F600 and Siemens AquaCarb1240C. The F300 GAC had <20% breakthrough of all PFAAs in DI water for up to 125,000 bed volumes (BVs). When DOM was present, >20% breakthrough of all PFAAs by 10,000 BVs was observed for all carbons.
authors.affiliation: Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO 80401, USA.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Appleman
authors.forename: Eric R V
authors.initials: ER
authors.lastname: Dickenson
authors.forename: Christopher
authors.initials: C
authors.lastname: Bellona
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Higgins
mesh_terms: D000143:Acids / Q000032:analysis / Q000737:chemistry*; D000327:Adsorption; D017738:Alkanesulfonic Acids / Q000032:analysis / Q000737:chemistry; D002210:Caprylates / Q000032:analysis / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry; D005374:Filtration / Q000379:methods*; D005466:Fluorocarbons / Q000032:analysis / Q000737:chemistry*; D007700:Kinetics; D036103:Nanotechnology; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D000143:Acids; D017738:Alkanesulfonic Acids; D002210:Caprylates; D005466:Fluorocarbons; D014874:Water Pollutants, Chemical; D014867:Water; D002606:Charcoal; D002244:Carbon; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid
keywords: Granular activated carbon adsorption; Nanofiltration; Perfluoroalkyl acids