Post-treatment modification method of polyamide composite nanofiltration membrane

Abstract

The invention discloses a post-treatment modification method of a polyamide composite nanofiltration membrane. The method comprises the following steps: carrying out post-treatment modification on a new nanofiltration membrane by using an alkaline alcohol solution, and dissolving and removing residual macromolecular chains in a polyamide active layer of the nanofiltration membrane by exerting a synergistic effect between an alkaline substance and an alcohol solvent, so that the polyamide active layer is etched and thinned, and the core functional layer which can play a solute interception role is reserved, so that the interception performance of the nanofiltration membrane is guaranteed, the mass transfer resistance of the nanofiltration membrane is greatly reduced, the water molecule permeability of the nanofiltration membrane is improved, the pure water flux is obviously improved, and the improvement amplitude can reach 100%. The post-treatment modification mode provided by the invention is low in cost and easy to operate, the treatment effect is superior to that of other traditional modification methods, and the method is expected to play an important role in performance improvement of the polyamide composite nanofiltration membrane.

Description

technical field [0001] The invention belongs to the technical field of membrane separation, and relates to a simple and effective nanofiltration membrane modification method capable of realizing synchronous regulation and optimization of multiple membrane structures and membrane performance parameters. Background technique [0002] With the rapid development of social economy, the shortage of global water resources has become increasingly prominent, and with the increasingly serious problem of water pollution, the problem of water resources has become a major challenge to the development of the national economy. Due to its excellent permeability and selectivity, polyamide composite nanofiltration membranes are widely used in water treatment fields such as seawater desalination, drinking water purification, brackish water desalination, industrial wastewater treatment, sewage and wastewater recycling, as well as food processing, biochemistry and Other industrial industries suc...

AI Technical Summary

Problems solved by technology

Therefore, how to overcome the disadvantages of traditional membrane material modification methods and overcome the contradiction between the improvement of water flux and the reduction of solute rejection rate, so as to further improve the permeation selectivity of polyamide composite nanofiltration membrane is the current nanofiltration membrane research. A major challenge in the field of production

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