title: Use of strong anion exchange resins for the removal of perfluoroalkylated substances from contaminated drinking water in batch and continuous pilot plants.
abstract: In recent years abnormally high levels of perfluoroalkylated substances (PFAS) have been detected both in surface and underground water sampled in an area covering approximately 150 square kilometers in the Veneto region (Italy) indicating the presence of a pollution point source (fluorochemicals production plant). Adsorption on granular activated carbon is an emergency measure which is poorly effective requiring frequent replacement. This work focuses on the application of three strong anion exchange resins (Purolite® A520E, A600E and A532E) for the removal of traces of PFOA, PFOS, PFBA and PFBS (concentration of hundreds of ng L(-1)) from drinking water. This technology is attractive for the possibility of reusing resins after an in-situ regeneration step. A strong relationship between the hydrophobicity of the exchange functional group of the resin and its capacity in removing PFAS exists. A600E (non hydrophobic) and A520E (fairly hydrophobic) show a reduced sorption capacity compared to A532E (highly hydrophobic). While A600E and A520E can be regenerated with solvent-less dilute solutions of non-toxic NH4Cl and NH4OH, A532E requires concentrated solutions of methanol or ethanol and 1% NH4Cl and for the sake of this work it was regarded as non-regenerable. The volume of regeneration effluents requiring incineration can be efficiently reduced by more than 96.5% by using reverse osmosis coupled with under-vacuum evaporation. Transmission electron analysis on saturated resins showed that large molecular macro-aggregates of PFAS can form in the intraparticle pores of resin indicating that ion exchange is not the only mechanism involved in PFAS removal.
authors.affiliation: Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35030 Padova, Italy. Electronic address: alessandro.zaggia@unipd.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Zaggia
authors.affiliation: Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35030 Padova, Italy.
authors.forename: Lino
authors.initials: L
authors.lastname: Conte
authors.affiliation: Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35030 Padova, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Falletti
authors.affiliation: Acque del Chiampo S.p.A. - Servizio Idrico Integrato, Via Ferraretta 20, 36071 Vicenza, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Fant
authors.affiliation: Acque del Chiampo S.p.A. - Servizio Idrico Integrato, Via Ferraretta 20, 36071 Vicenza, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Chiorboli
mesh_terms: D000327:Adsorption; D000837:Anion Exchange Resins / Q000737:chemistry*; D019149:Bioreactors; D060766:Drinking Water / Q000032:analysis*; D005466:Fluorocarbons / Q000737:chemistry*; D060587:Groundwater / Q000032:analysis*; D007558:Italy; D010865:Pilot Projects; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D000837:Anion Exchange Resins; D060766:Drinking Water; D005466:Fluorocarbons; D014874:Water Pollutants, Chemical
keywords: Anion exchange resin; Granular activated carbon; Ion exchange; PFAS; Removal