What is provided is a metal ion recovery device including a raw solution tank that is configured to store a metal ion containing raw solution including metal ions, a recovery liquid tank that is configured to store a metal ion recovery liquid including metal ions recovered from the metal ion containing raw solution, a cylindrical metal ion selective permeable membrane that partitions off the raw solution tank and the recovery liquid tank and selectively transmits the metal ions, an anode that is electrically connected to a surface of the selective permeable membrane on a side close to the raw solution tank, and a cathode that is electrically connected to a surface of the selective permeable membrane on a side close to the recovery liquid tank.

What is provided is a metal ion recovery device including a raw solution tank that is configured to store a metal ion containing raw solution including metal ions, a recovery liquid tank that is configured to store a metal ion recovery liquid including metal ions recovered from the metal ion containing raw solution, a cylindrical metal ion selective permeable membrane that partitions off the raw solution tank and the recovery liquid tank and selectively transmits the metal ions, an anode that is electrically connected to a surface of the selective permeable membrane on a side close to the raw solution tank, and a cathode that is electrically connected to a surface of the selective permeable membrane on a side close to the recovery liquid tank.

A method for efficiently treating boron from water to be treated, an apparatus for producing pure water, and a method for producing pure water. An apparatus for removing boron includes a low-pressure reverse osmosis membrane apparatus to which is supplied water to be treated, a pH adjustment apparatus to adjust a pH of permeated water from the low-pressure reverse osmosis membrane apparatus to 5.0 to 9.0, a high-pressure reverse osmosis membrane apparatus to which is supplied the water adjusted by the pH adjustment apparatus, and an electrodeionization to which is supplied permeated water from the high-pressure reverse osmosis membrane apparatus.

A method for efficiently treating boron from water to be treated, an apparatus for producing pure water, and a method for producing pure water. An apparatus for removing boron includes a low-pressure reverse osmosis membrane apparatus to which is supplied water to be treated, a pH adjustment apparatus to adjust a pH of permeated water from the low-pressure reverse osmosis membrane apparatus to 5.0 to 9.0, a high-pressure reverse osmosis membrane apparatus to which is supplied the water adjusted by the pH adjustment apparatus, and an electrodeionization to which is supplied permeated water from the high-pressure reverse osmosis membrane apparatus.

The present inventive concept relates to a chemically modified anion exchange membrane and a method of preparing the same and, more particularly, an anion exchange membrane in which sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane are substituted with anion conductive groups such as ammonium group, phosphonium group, imidazolium group, pyridinium group and sulfonium group, and a method of preparing an anion exchange membrane by chemically modifying sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane.

The present inventive concept relates to a chemically modified anion exchange membrane and a method of preparing the same and, more particularly, an anion exchange membrane in which sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane are substituted with anion conductive groups such as ammonium group, phosphonium group, imidazolium group, pyridinium group and sulfonium group, and a method of preparing an anion exchange membrane by chemically modifying sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane.

Disclosed is a method for resolving an optical isomer from a racemate by means of electrodialysis. Specifically, an electrodialysis technique is used in an enzymatic resolution process, mainly in the separation of products after enzymatic resolution. Taking a preparation process for D-pantolactone as an example, the key point is that D-pantoic acid and L-pantolactone are separated from an enzymatic resolution solution by means of an electrodialysis method, which replaces the existing organic solvent extraction method. The process method is simple and easy to operate, has a high yield of D-pantoic acid of a good purity, greatly reduces the usage amount of an organic solvent, reduces production costs and is environmentally friendly, such that the working environment of workers can be improved to a great extent, and the operation safety index is improved.

What is provided is a metal ion recovery device including: a raw solution tank that is configured to store a metal ion containing raw solution including metal ions; a recovery liquid tank that is configured to store a metal ion recovery liquid including metal ions recovered from the metal ion containing raw solution; a metal ion selective permeable membrane that separates the raw solution tank and the recovery liquid tank and selectively transmits the metal ions; an anode that is arranged on a side of the metal ion selective permeable membrane close to the raw solution tank; a cathode that is arranged on a side of the metal ion selective permeable membrane close to the recovery liquid tank; a porous current collector that is formed of a conductive material; a first spacer that is configured to maintain a gap between the metal ion selective permeable membrane and the anode; and a second spacer that is configured to maintain a gap between the metal ion selective permeable membrane and the cathode, in which the anode is arranged to be electrically connected to the metal ion selective permeable membrane through the porous current collector, and the cathode is arranged to be electrically connected to the metal ion selective permeable membrane through the porous current collector, and two or more of at least one of the raw solution tank and the recovery liquid tank are provided.

A system comprises an electrodialysis apparatus, which includes first and second reservoirs, wherein a salt concentration in the first reservoir reduces below a threshold concentration and salt concentration in the second reservoir increases during an operation mode. A first electrode comprises a first solution of a first redox-active electrolyte material, and a second electrode comprises a second solution of a second redox-active electrolyte material. In a first reversible redox reaction between the first electrode and first electrolyte material at least one ion is accepted from the first reservoir, and in a second reversible redox reaction between the second electrode and second electrolyte material at least one ion is driven into the second reservoir. A first type of membrane is disposed between the first and second reservoirs, and a second type of membrane, different from the first type, is disposed between the respective electrodes and reservoirs.

A system comprises an electrodialysis apparatus, which includes first and second reservoirs, wherein a salt concentration in the first reservoir reduces below a threshold concentration and salt concentration in the second reservoir increases during an operation mode. A first electrode comprises a first solution of a first redox-active electrolyte material, and a second electrode comprises a second solution of a second redox-active electrolyte material. In a first reversible redox reaction between the first electrode and first electrolyte material at least one ion is accepted from the first reservoir, and in a second reversible redox reaction between the second electrode and second electrolyte material at least one ion is driven into the second reservoir. A first type of membrane is disposed between the first and second reservoirs, and a second type of membrane, different from the first type, is disposed between the respective electrodes and reservoirs.