title: Effects of feed solution chemistry on low pressure reverse osmosis filtration of cesium and strontium.
abstract: The objective of this study was to identify the removal mechanisms of radionuclides by reverse osmosis (RO) membranes under conditions relevant to full-scale water treatment. For this purpose, the effects of feed solution chemistry on the removal of Cs and Sr by a low pressure RO system was investigated by systematically varying membrane surface charge, ionic composition, and organic matter concentrations. The results showed that the effects of solution chemistry on the filtration of Cs and Sr were related to their hydrated ionic radius, resulting in the predominance of the Donnan's effect and electrostatic interactions, respectively. Consequently, the rejection of Cs increased more pronouncedly than Sr with the increases of feed concentration. Due to the Donnan's effect, different anions decreased the rejection of Cs to different extents in accordance to the order of anions' radii as SO4(2-)>Cl(-)>NO3(-)>F(-). The variations in Sr rejection were influenced by the electrostatic interactions between Sr(2+) and the membrane. In addition, humic acid (HA) lowered the rejection of Cs and caused significant membrane flux decline, but did not change the rejection of Sr. Sr also aggravated HA fouling of the membrane.
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875, PR China. Electronic address: dingshiyuan@bnu.edu.cn.
authors.forename: Shiyuan
authors.initials: S
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875, PR China. Electronic address: yangyu@bnu.edu.cn.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875, PR China. Electronic address: huanghaiou@bnu.edu.cn.
authors.forename: Haiou
authors.initials: H
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875, PR China. Electronic address: 799599501@qq.com.
authors.forename: Hengchen
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875, PR China; Xi'an High-Tech Institute, No. 2, Tongxin Street, Baqiao District, Xi'an 710025, PR China. Electronic address: houlian678@hotmail.com.
authors.forename: Li-an
authors.initials: LA
authors.lastname: Hou
mesh_terms: D002586:Cesium / Q000737:chemistry*; D005374:Filtration; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D009995:Osmosis; D011312:Pressure; D012996:Solutions; D013324:Strontium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D006812:Humic Substances; D008567:Membranes, Artificial; D012996:Solutions; D014874:Water Pollutants, Chemical; D002586:Cesium; D013324:Strontium
keywords: Cesium; Co-existing ions; Radionuclides; Reverse osmosis membrane; Strontium