Anti-pollution reverse osmosis membrane and preparation method thereof

Abstract

The invention provides an anti-pollution reverse osmosis membrane and a preparation method thereof. The reverse osmosis membrane comprises a support layer and a polyamide desalination layer formed on the support layer, and the surface of the polyamide desalination layer is modified by a fluorine-containing amine and a guanidyl-containing compound. The reverse osmosis membrane disclosed by the invention is prepared by a method of firstly carrying out heat treatment on the polyamide desalination layer and then conducting reacting with a modified substance, and the modification process is carried out on the outer surface of the membrane without influencing the performance of the separation membrane. The surface of the membrane contains fluorine, so that the adhesion of pollutants is reduced, and after the pollutants are deposited in the later period, as the surface of the membrane contains guanidyl, microorganisms deposited on the surface of the membrane can be killed, and the pollution speed of the membrane is reduced.

Description

technical field [0001] The invention belongs to the field of membrane technology, and in particular relates to an anti-pollution reverse osmosis membrane and a preparation method thereof. Background technique [0002] Biological fouling is one of the main obstacles restricting the further popularization and application of reverse osmosis membrane separation technology. Introducing inorganic or organic antibacterial agents to the surface of the reverse osmosis membrane to prepare a new type of anti-biological fouling reverse osmosis membrane can effectively inhibit the growth and reproduction of microorganisms on the surface of the membrane. However, the current research work still has the following problems: (1) Although the modified membrane improves the anti-biofouling performance of the membrane, the permselective performance of the membrane is often sacrificed; (2) Some modification methods are complicated or not environmentally friendly, which is not conducive to Scale...

AI Technical Summary

Problems solved by technology

However, the current research work still has the following problems: (1) Although the modified membrane improves the anti-biofouling performance of the membrane, the permselective performance of the membrane is often sacrificed; (2) Some modification methods are complicated or not environmentally friendly, which is not conducive to Scale-scale preparation of modified membranes

[0003] CN108786498A discloses an anti-adhesion and anti-biological fouling reverse osmosis membrane; the reverse osmosis membrane is formed by linking the remaining acid chloride groups on the surface of the aromatic polyamide composite reverse osmosis membrane with biguanide-based chitosan; Immersing the ecological membrane into the biguanide-based chitosan material solution will affect the structure of the polyamide layer, and the obtained membrane has a low desalination rate, and this method needs to synthesize biguanide-based chitosan, which is costly and cumbersome to operate

[0004] Dong Chenxi ("Preparation and Performance Research of Anti-Biofouling Aromatic Polyamide Composite Reverse Osmosis Membrane", School of Chemical Engineering, Tianjin University, 2017) introduced PVAmG to the surface of reverse osmosis membrane by secondary interfacial polymerization method to prepare PVAmG modified For reverse osmosis membranes, the flux and rejection rate are basically unchanged after modification; this method needs to use polymer polyvinylamine (PVAm) and dicyandiamide containing active amino groups as raw materials to prepare cations with guanidine groups as antibacterial groups. Polymer——biguanidinated polyvinylamine (PVAmG), using the secondary interface polymerization modification method to make PVAmG react with the nascent membrane, and graft PVAmG to the surface of the reverse osmosis membrane, so this method is also to directly graft the nascent membrane Branch modification, and the synthesis of biguanylated polyvinylamine is required, the cost is high, and the operation is cumbersome

[0005] The above methods all make the primary membrane react with the modified product, which affects the desalination performance of the reverse osmosis membrane, and compound the modified product with a complex structure, which is costly and cumbersome to operate.

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