Hollow fiber type composite nano-filtration membrane and preparation method thereof

Abstract

The invention relates to a hollow fiber type composite nano-filtration membrane and a preparation method thereof. The hollow fiber type composite nano-filtration membrane comprises a hollow fiber microporous base membrane adopted as a supporting layer, a polysulfone transition layer, and a polyamide composite layer, wherein the polysulfone transition layer is positioned inside membrane holes of the hollow fiber microporous base membrane, and the polyamide composite layer is positioned inside membrane holes of the polysulfone transition layer. The preparation method comprises: adopting a thermally induced phase separation method to obtain an asymmetric microporous base membrane, adopting an impregnation phase transformation method to obtain the polysulfone transition layer in the micro holes, and adopting pressure control and an interface condensation polymerization reaction to obtain the polyamide composite layer. The hollow fiber type composite nano-filtration membrane provides a sodium chloride salt solution entrapment rate of more than 90%, a divalent salt ion entrapment rate of more than 95%, and a pollutant entrapment rate of more than 99% under 0.2-0.8 MPa, such that the hollow fiber type composite nano-filtration membrane has characteristics of high strength, washing resistance, large flux and the like, wherein the pollutants have a molecular weight of 300-200,000 Daltons.

Description

technical field

[0001] The invention relates to a hollow fiber type composite nanofiltration membrane capable of treating suspended pollutants and a preparation method thereof. Background technique

[0002] The research and development of hollow fiber reverse osmosis membrane is expected to lead the future of membrane technology. At present, commercial RO membranes are all composite roll membranes, which are easy to pollute and difficult to clean, which puts forward high requirements on the influent water quality of RO membranes, so hollow fiber ultra / microfiltration (UF / MF) membranes have to be used as RO membranes. Pretreatment, the so-called dual-membrane (UF / MF-RO) water treatment integrated process, severely restricts the further reduction of membrane water treatment costs. Improving the anti-fouling performance of the membrane can relax the requirements of the influent water quality: this is the key to the integration of the double membrane method (UF / MF-RO) into the ...

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