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Selection techniques of industrial reverse osmosis membranes



In the industrial use of reverse osmosis membrane or more, but also to pay attention to the way to choose, how to choose industrial reverse osmosis membrane? Next small make-up for you to introduce the selection of industrial reverse osmosis membrane skills, follow this article to understand it.


(1) Film heat resistance and mechanical strength


The membrane of heat-resisting performance improvement, which is beneficial to need in the industry under the high temperature used in the separation process of operation, and performance improvement of the other, means that the separable higher temperature solution, solution temperature rise, the water through the rate of increase, in high voltage side of the membrane mass transfer coefficient and the coefficient of permeability of salt is also a slight increase. Therefore, we should try to choose the film material with better heat resistance, and consider the properties of the solution to be tested, the use time, and the requirements of the film performance.


(2) Chemical stability of the membrane


The chemical stability of the membrane mainly depends on the oxidation resistance and hydrolysis resistance of the membrane, which not only depends on the chemical properties of the membrane itself but also depends on the properties of the separation fluid. Generally, aqueous solutions contain oxidizing substances such as sodium hypochlorite, dissolved oxygen, hydrogen peroxide, and hexavalent chromium, which are easy to produce active free radicals and chain initiate reactions and chain transfer reactions with polymer film materials, resulting in membrane oxidation and affecting film performance and life. In addition, the membrane is hydrolyzed and oxidized at the same time. When the main chain of polymer for molding contains hydrolyzed chemical groups -CONH-, -COOR -,-CN2-O-, etc., these groups are easy to produce hydrolysis and degradation reaction under the action of acid or alkali so that the membrane performance is damaged.

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