KR-20260064713-A - Method of operating an electrodialysis device for an aqueous solution containing an organic solvent using an electrodialysis device equipped with an anion exchange membrane manufactured by a cross-linking polymerization method

KR20260064713AKR 20260064713 AKR20260064713 AKR 20260064713AKR-20260064713-A

Abstract

A method of operating an electrodialysis device comprises an electrodialysis process in which an aqueous solution containing halide ions and a polar organic solvent is electrodialyzed using an electrodialysis device equipped with an anion exchange membrane manufactured by a cross-linking polymerization method, wherein the aqueous solution contains 200 mg/L or more of iodide ions, and in the electrodialysis process, the anion exchange membrane comprises an anion exchange membrane in which, when an electrodialysis test is performed using a desalted solution containing iodide ions and sulfate ions, the iodide ion retention rate in the desalted solution is 5%, and the permeability (%) of iodide ions ( I- ) in the concentrate is defined as TI and the permeability (%) of sulfate ions ( SO42- ) is defined as TSO4 , wherein TI / TSO4 is 3.5 or higher.

Inventors

바바, 마사히코
나카무라, 유키
도이, 쇼이치

Assignees

가부시키가이샤 고도 시겐

Dates

Publication Date: 20260507
Application Date: 20241002
Priority Date: 20231012

Claims (9)

A method of operating an electrodialysis device comprising an electrodialysis process for electrodialyzing an aqueous solution containing halide ions and a polar organic solvent using an electrodialysis device equipped with an anion exchange membrane manufactured by a cross-linking polymerization method, and The above aqueous solution contains 200 mg/L or more of iodide ions, and In the above electrodialysis process, The above anion exchange membrane comprises an anion exchange membrane in which, when an electrodialysis test is performed using a desalination solution containing iodide ions and sulfate ions, the ratio T I / T SO 4 is 3.5 or higher when the residual iodide ion content in the desalination solution is 5% and the transmittance (%) of iodide ions ( I- ) in the concentrate is defined as T I and the transmittance (%) of sulfate ions ( SO 4 2- ) is defined as T SO 4 . Method of operating an electrodialysis device.
In paragraph 1, In the above electrodialysis process, A method of operating an electrodialysis device, wherein the above-mentioned polar organic solvent comprises an organic solvent having a relative permittivity of 5 or higher at 25°C.
In paragraph 1 or 2, A method of operating an electrodialysis device, wherein the above aqueous solution comprises 0.1 mass% or more and 50 mass% of the above polar organic solvent.
In paragraph 1 or 2, A method of operating an electrodialysis apparatus in which, in the above electrodialysis process, the concentration of halide ions in the desalinated solution by absorbance at the endpoint is 0.5 g/L or more and 5 g/L or less.
In paragraph 1 or 2, A method of operating an electrodialysis device, wherein the above iodide ions are obtained by reducing one or more selected from the group consisting of iodine ( I₂ ), iodic acid ( HIO₃ ), periodic acid ( HIO₄ ), and iodine compounds.
In paragraph 1 or 2, A method of operating an electrodialysis device, wherein the anion exchange membrane comprises a base substrate including a polyolefin and an ion-selective permeable layer formed on one side or both sides of the base substrate.
In paragraph 1 or 2, In the above electrodialysis process, The above anion exchange membrane comprises an anion exchange membrane having a rate of change in ion exchange capacity within ±5% before and after immersion treatment in a polar organic solvent at a concentration of 50 mass%. Method of operating an electrodialysis device.
In paragraph 1 or 2, In the above electrodialysis process, The above anion exchange membrane comprises an anion exchange membrane having a rate of change in water content measured by the Karl Fischer method within ±20% before and after an immersion treatment in isopropyl alcohol at a concentration of 50 mass%, Method of operating an electrodialysis device.
It is an electrodialysis device for electrodialyzing an aqueous solution containing halide ions and a polar organic solvent, and Concentration room and, Desalination room, and, The above concentration chamber and the above desalination chamber are partitioned by an anion exchange membrane and a cation exchange membrane manufactured by a cross-linking polymerization method, and The above aqueous solution contains 200 mg/L or more of iodide ions, and The above anion exchange membrane comprises an anion exchange membrane in which, when an electrodialysis test is performed using a desalination solution containing iodide ions and sulfate ions, the ratio T I / T SO 4 is 3.5 or higher when the residual iodide ion content in the desalination solution is 5% and the transmittance (%) of iodide ions ( I- ) in the concentrate is defined as T I and the transmittance (%) of sulfate ions ( SO 4 2- ) is defined as T SO 4 . Electrodialysis device.

Description

Method of operating an electrodialysis device for an aqueous solution containing an organic solvent using an electrodialysis device equipped with an anion exchange membrane manufactured by a cross-linking polymerization method The present invention relates to a method of operating an electrodialysis device and an electrodialysis device. Various developments have been made so far regarding the technology for electrodialyzing wastewater containing iodine. As a technology of this type, the technology described in Patent Document 1 is known, for example. In addition to iodine components such as iodide ions ( I- ), divalent ions such as sulfate ions ( SO₄2- ) may also coexist in the wastewater. For example, sulfate ions are typically contained in the wastewater at a concentration of 1 g/L or more, which is below the saturation solubility of sulfates, and more generally at a concentration of about 20 to 50 g/L. Patent Document 1 describes a method of performing electrodialysis on a stock solution contained in a desalination chamber, which contains an inorganic anion having iodine and an inorganic anion having fluorine, using a monovalent selective anion exchange membrane, etc. (Claim 1 of Patent Document 1, examples, etc.). FIG. 1 is a cross-sectional view schematically illustrating an example of the configuration of an electrodialysis device of the present embodiment. FIG. 2 is a schematic diagram illustrating an example of the configuration of an iodine recovery system of the present embodiment. FIG. 3 is a flowchart illustrating an example of an iodine recovery process of the present embodiment. Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in all drawings, like components are given like reference numerals, and descriptions are omitted as appropriate. Furthermore, the drawings are schematic diagrams and do not correspond to actual dimensional ratios. An overview of the operation method of the electrodialysis device of the present embodiment is described. The method of operating an electrodialysis device of the present embodiment includes an electrodialysis process of electrodialyzing an aqueous solution containing halide ions and a polar organic solvent using an electrodialysis device equipped with an anion exchange membrane manufactured by a cross-linking polymerization method. In this embodiment, by using an anion exchange membrane manufactured by a cross-linking polymerization method, solvent resistance can be improved compared to an anion exchange membrane manufactured by a casting method. In preliminary experiments, it was found that an anion exchange membrane manufactured by a casting method dissolved in a dimethylacetamide solvent at a concentration of about 50%. In addition, an electrodialysis device equipped with an anion exchange membrane manufactured by a cross-linking polymerization method is also preferably equipped with a cation exchange membrane manufactured by a cross-linking polymerization method. In addition, polar organic solvents have high water miscibility and are expected to reduce membrane damage to ion exchange membranes compared to non-polar organic solvents. According to the present embodiment, it is possible to realize a method of operating an electrodialysis device having excellent selective permeability of halide ions to a polar organic solvent. As one specific embodiment, one or more types of halide ions can be selectively permeated into a concentrate while leaving a polar organic solvent in an aqueous solution (desalted solution). In this embodiment, as the halide ion, iodide ions, chloride ions, fluoride ions, bromide ions, etc., can be used without limitation. These may be used individually or in combination of two or more types. Electrodialyzing an aqueous solution (desalted solution) containing halide ions and a polar organic solvent means (i) permeating at least one type of halide ion into the concentrate, and/or (ii) leaving at least one type of halide ion in the desalted solution. When using two or more types of halide ions with different mobilities during electrodialysis, it is possible to allow the species with relatively high mobility to pass through the concentrate and leave the species with relatively low mobility in the desalt solution. In addition, the mobility is in the order of iodide ions, bromide ions, chloride ions, and fluoride ions. In the first operating method, at least iodide ions can be selectively permeated into a concentrate from an aqueous solution (desalted solution) containing one or more types of halide ions. In the second operating method, iodide ions and chloride ions can be selectively permeated into a concentrate from an aqueous solution (desalted solution) containing multiple types of halide ions. In the third operating method, fluoride ions can be selectively retained in an aqueous solution (desalted solution) containing one or more types of halide ions. The operating method of