Positively charged composite nano filtration membrane and preparation method

Abstract

The invention discloses a positively charged composite nano filtration membrane. The nano filtration membrane is characterized in that a modified meta-aramid hollow fiber membrane is taken as a base membrane, an ultra-thin polyamide layer is formed by positively charged polyelectrolyte, polyamine and polyacyl chloride through interfacial polymerization, and a method for preparing the composite nano filtration membrane is prepared. According to the composite nano filtration membrane, pure water throughput under 0.3 MPa is greater than or equal to 24 L (m2 h), the desalting rate of 2g / L divalentcation salt solution is greater than or equal to 90%, the needed cost is lower, and industrialization is easy. The preparation method is simple, operation is easy, reaction conditions are mild, the performance is stable, and the market application prospects are wider.

Description

technical field

[0001] The invention relates to the technical field of polymer nanofiltration membranes, in particular to a positively charged composite nanofiltration membrane and a preparation method thereof. Background technique

[0002] Nanofiltration (NF) is a membrane separation technology between ultrafiltration (UF) and reverse osmosis (RO). Nanofiltration membranes have good separation performance for high-priced and divalent salts and small molecular organics, and also have the advantages of low operating pressure, large pure water flux, and lower cost. They are widely used in water softening, desalination, and wastewater treatment. application prospects. At present, the preparation methods of nanofiltration membrane mainly include phase inversion method, dip coating method, surface graft polymerization method and interfacial polymerization method. Among them, the interfacial polymerization method is to prepare a nanofiltration functional separation layer on the u...

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