Study on Anti-scaling Performance of Reverse Osmosis Membrane of Composite Exfoliated and Modified Nano-montmorillonite
The high operating pressure,high salt rejection ratio and concentration polarization in the reverse osmosis process make it easy to form calcium sulfate scale on the reverse osmosis membrane surface,resulting in reduced water permeability and high operating costs.In addition to process control,the nature of membrane surfaces are crucial to control membrane fouling.Nanomaterials have been extensively used to improve water permeability and optimize the surface properties of polyamide(PA)layers contributed by their excellent hydrophilic properties and abundant specific ion channels.In this study,the surface roughness,hydrophilicity and surface charge of the PA membrane were modified by the incorporation of exfoliated and modified nano-montmorillonite.As compared to the control membrane,the SDS-MMT membrane exhibited the best anti-scaling properties and lower flux decline ratio(DF=27.1％±6.2％)and higher flux recovery ratio(FR=94.6％±9.3％).It can be concluded that the presence of montmorillonite and surfactant SDS improves the hydrophilicity and cross-linking degree of the PA membrane surface,and the decrease of corresponding—COOH content,which is conducive to anti-scaling.This study also sheds new light on the research of anti-scaling membranes in membrane separation.
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维普
