title: RBS characterization of arsenic(III) partitioning from aqueous phase into the active layers of thin-film composite NF/RO membranes.
abstract: The main objective of this study was to apply Rutherford backscattering spectrometry (RBS) for characterizing the partitioning of arsenic(III) from aqueous phase into the active layer of NF/RO membranes. NF/RO membranes with active layer materials including polyamide (PA), PA-polyvinyl alcohol derivative (PVA), and sulfonated-polyethersulfone (SPES) were investigated. The partition coefficient was found to be constant in the investigated As-(III) concentration range of 0.005-0.02 M at each pH investigated. The partitioning of As(III) when predominantly present as H3AsO3 (pH 3.5-8.0) was not affected by pH. In contrast, the partition coefficient of As(III) at pH 10.5, when it was predominantly present as H2AsO3-, was found to be approximately 33-49% lower than that of H3AsO3. The partition coefficients of H3AsO3 and H2AsO3- for membranes containing PA in their active layers were within the respective ranges of 6.2-8.1 and 3.6-5.4, while the corresponding values (4.8 and 3.0, respectively) for the membrane with SPES active layer were approximately 30% lower than the average values for the PA membranes.
authors.affiliation: Department of Civil and Environmental Engineering, National Science Foundation Science and Technology Center of Advanced Materials for the Purification of Water with Systems, University of Illinois at Urbana-Champaign, 61801, USA.
authors.forename: Baoxia
authors.initials: B
authors.lastname: Mi
authors.forename: Benito J
authors.initials: BJ
authors.lastname: Mariñas
authors.forename: David G
authors.initials: DG
authors.lastname: Cahill
mesh_terms: D001151:Arsenic / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D009995:Osmosis; D013057:Spectrum Analysis; D014462:Ultrafiltration; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods
chemical_list: D008567:Membranes, Artificial; D014874:Water Pollutants, Chemical; D001151:Arsenic