title: Changes in physicochemical and transport properties of a reverse osmosis membrane exposed to chloraminated seawater.
abstract: This study contributed to improving our understanding of how disinfectants, applied to control biofouling of reverse osmosis (RO) membranes, result in membrane performance degradation. We investigated changes in physicochemical properties and permeation performance of a RO membrane with fully aromatic polyamide (PA) active layer. Membrane samples were exposed to varying concentrations of monochloramine, bromide, and iodide in both synthetic and natural seawater. Elemental analysis of the membrane active layer by Rutherford backscattering spectrometry (RBS) revealed the incorporation of bromine and iodine into the polyamide. The kinetics of polyamide bromination were first order with respect to the concentration of the secondary oxidizing agent Br2 for the conditions investigated. Halogenated membranes were characterized after treatment with a reducing agent and heavy ion probes to reveal the occurrence of irreversible ring halogenation and an increase in carboxylic groups, the latter produced as a result of amide bond cleavage. Finally, permeation experiments revealed increases in both water permeability and salt passage as a result of oxidative damage.
authors.affiliation: NSF Science and Technology Center of Advanced Materials for the Purification of Water with Systems (WaterCAMPWS), Safe Global Water Institute, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
authors.forename: Lauren
authors.initials: L
authors.lastname: Valentino
authors.forename: Tennie
authors.initials: T
authors.lastname: Renkens
authors.forename: Thomas
authors.initials: T
authors.lastname: Maugin
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Croué
authors.forename: Benito J
authors.initials: BJ
authors.lastname: Mariñas
mesh_terms: D057219:Biofouling; D001965:Bromides / Q000737:chemistry; D002700:Chloramines; D005374:Filtration / Q000379:methods; D007454:Iodides / Q000737:chemistry; D008567:Membranes, Artificial; D009757:Nylons / Q000737:chemistry; D009995:Osmosis; D010539:Permeability; D012623:Seawater / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D001965:Bromides; D002700:Chloramines; D007454:Iodides; D008567:Membranes, Artificial; D009757:Nylons; C030816:chloramine