Regeneration method for failure polyethylenimine-modified cation exchange membranes

A technology of cation exchange membrane and polyethyleneimine, which is applied in the field of regeneration of cation exchange membrane, can solve problems such as invalidation, pollution, monovalent selectivity of single cation exchange membrane, achieve prolong life, improve cross-linking stability, and the method is simple and easy line effect

Inactive Publication Date: 2017-01-04
ZHEJIANG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of this invention is to provide a kind of regeneration method of the polyethyleneimine modified cationic exchange membrane of invalidation, to solve its in use process because inorganic compound, macromolecule or solid substance accumulate on the cationic exchange membrane surface or membrane interior The surface and internal contamination of the membrane and the chemical degradation of the polyethyleneimine monovalent selective group on the surface of the cation exchange membrane caused the failure of the monovalent selectivity of the single cation exchange membrane

Method used

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  • Regeneration method for failure polyethylenimine-modified cation exchange membranes
  • Regeneration method for failure polyethylenimine-modified cation exchange membranes
  • Regeneration method for failure polyethylenimine-modified cation exchange membranes

Examples

Experimental program
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Embodiment 1

[0036] Japanese SELEMION that loses ion selectivity after industrial application TM The cation exchange membrane is an invalid membrane, soaked in 10% methanol solution and treated with ultrasonic vibration at 60kHz for 2h, then soaked in 0.05M dilute sulfuric acid solution and treated with ultrasonic vibration at 60kHz for 2h, in order to eliminate the monovalent selective functional failure membrane The pollutants on the surface and the chemically degraded polyethyleneimine (PEI) functional groups were rinsed three times with deionized water after two ultrasonic treatments to remove the residual solution on the surface, and then used figure 1 The electrodeposition apparatus shown performs electrodeposition.

[0037] Fix the cation exchange membrane to be deposited in the middle, and the two auxiliary membranes are Japanese SELEMION TM anion exchange membrane. When energized, the two sides of the film to be deposited form a concentrated chamber and a dilute chamber respecti...

Embodiment 2

[0040] According to embodiment 1, add sodium chloride concentration in the dilute chamber and be 0.5mol / L, the mixed solution that polyethyleneimine concentration is reduced to 2g / L, be the sodium chloride solution of 0.5mol / L in the concentrated chamber, with 0.2 The mol / L sodium sulfate solution is used as the electrolyte solution in the electrode chamber, and the current on the membrane surface is kept at 10mA / cm 2The deposition of polyethyleneimine on the film was completed after energizing for 0.5 hours; the film deposited with polyethyleneimine was taken out, the surface of the film was cleaned with deionized water, and then placed in an aqueous solution of epichlorohydrin with a volume concentration of 20% for crosslinking for 2 hours; The cross-linked membrane is rinsed with ultrapure water to remove the surface cross-linking agent, and then the membrane is tested in an electrodialysis device according to Example 1, and the change of the modified membrane over time—the ...

Embodiment 3

[0042] According to embodiment 1, adding the concentration of sodium chloride in the dilute chamber is a mixed solution of 0.5mol / L and polyethylenimine concentration of 2g / L; The sodium sulfate solution is used as the electrolyte solution in the electrode chamber, and the surface current of the electrodeposited film is adjusted to 20mA / cm 2 The deposition of polyethyleneimine on the film is completed under electricity and energized for 0.5 hours; then the film deposited with polyethyleneimine is taken out, the surface of the film is cleaned with deionized water, and then cross-linked in an aqueous solution of epichlorohydrin with a volume concentration of 20%. 2h; the membrane after crosslinking is rinsed with ultrapure water to remove the surface crosslinking agent, and then the membrane is tested in an electrodialysis device according to Example 1, and the change of the concentration of divalent cations over time of the modified membrane is as follows Image 6 .

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Abstract

The invention discloses a regeneration method for failure polyethylenimine-modified cation exchange membranes. The regeneration method includes steps of (1), successively soaking the failure polyethylenimine-modified cation exchange membranes in alcoholic solution and dilute sulfuric acid to carry out ultrasonic vibration cleaning treatment on the failure polyethylenimine-modified cation exchange membranes, and cleaning the cleaned failure polyethylenimine-modified cation exchange membranes by the aid of deionized water to remove residual solution and substances on the surfaces of the failure polyethylenimine-modified cation exchange membranes; (2), arranging new polyethylenimine on the surfaces of the cation exchange membranes by means of electro-deposition by the aid of electro-deposition processes after the cation exchange membranes are treated at the step (1); (3), soaking the cation exchange membranes in epichlorohydrin aqueous solution after the cation exchange membranes are treated at the step (2), carrying out cross-linking by the aid of epichlorohydrin which is used as a cross-linking agent and then washing the cation exchange membranes to restore monovalent cation selectivity functions of the failure polyethylenimine-modified cation exchange membranes. The regeneration method has the advantage that problems of membrane surface and internal contamination of existing polyethylenimine-modified cation exchange membranes in service procedures and failure of monovalent cation selectivity of the existing polyethylenimine-modified cation exchange membranes can be solved by the aid of the regeneration method.

Description

technical field [0001] The invention relates to a method for regenerating invalid polyethyleneimine (PEI) modified cation exchange membranes. Background technique [0002] Ion-exchange membranes are currently widely used in various industrial fields, and cation membranes with monovalent cation selectivity are highly valued. Due to its high amino content, high reactivity and good film-forming properties of polyethyleneimine. Among them, cation exchange membranes modified with PEI have been widely used in seawater desalination and water treatment. CN102941026 discloses a method for introducing functional polymer polyethyleneimine on a cation exchange base membrane by a deposition method, and using ion imprinting technology to prepare an ion exchange composite membrane selective to a single cation. However, the fouling of the membrane and the damage of the functional layer are a real problem of this kind of cation exchange membrane, which will not only destroy the ion selecti...

Claims

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Application Information

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IPC IPC(8): B01J49/00C25D9/02
CPCC25D9/02
Inventor 沈江南赵严汤恺妮董祥柳慧敏
Owner ZHEJIANG UNIV OF TECH
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