Changes in Physicochemical and Transport Properties of a Reverse Osmosis Membrane Exposed to Chloraminated Seawater

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• 作者：Lauren Valentino ; Tennie Renkens ; Thomas Maugin ; Jean-Philippe Crou茅 ; Benito J. Mari帽as
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：February 17, 2015
• 年：2015
• 卷：49
• 期：4
• 页码：2301-2309
• 全文大小：334K
• ISSN：1520-5851

文摘

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.