The present invention relates to a process for the purification of an acidic human milk oligosaccharide (HMO) from a fermentation broth using ion exchange methods. This process allows for a reduction of the number and/or extent of desalting operations, such as electrodialysis. It is even possible to refrain from such operations.

The present invention relates to a process for the purification of an acidic human milk oligosaccharide (HMO) from a fermentation broth using ion exchange methods. This process allows for a reduction of the number and/or extent of desalting operations, such as electrodialysis. It is even possible to refrain from such operations.

The present invention relates to a method for identifying the unit causing a raw water leak in a condenser of a thermal power plant consisting of n units.

The present invention relates to a method for identifying the unit causing a raw water leak in a condenser of a thermal power plant consisting of n units.

A method of removing boron from water to be treated includes subjecting the water to be treated to reverse osmosis membrane treatment, subjecting at least part of permeated water after the reverse osmosis membrane treatment to cation-removing treatment, and measuring a concentration of boron in the resulting permeated water after the cation-removing treatment, in which a measured value for the concentration of boron is used to regulate at least one of: (a) the recovery rate of water to be treated in the above reverse osmosis membrane treatment, (b) the temperature of the water to be treated, (c) the pH of the water to be treated, (d) the supply pressure of the water to be treated, which pressure is applied to the reverse osmosis membrane during the reverse osmosis membrane treatment, and (e) when the reverse osmosis membrane used for the reverse osmosis membrane treatment should be changed.

To provide an acid-type sulfonic acid group-containing polymer which is excellent in hydrogen gas barrier properties and hot water resistance and which generates less oligomer during production; a liquid composition and a polymer electrolyte membrane comprising this acid-type sulfonic acid group-containing polymer; and a membrane electrode assembly and a polymer electrolyte fuel cell provided with the polymer electrolyte membrane.

This acid-type sulfonic acid group-containing polymer is a polymer which has perfluoromonomer units, no monomer units having a halogen atom other than a fluorine atom, and acid-type sulfonic acid groups, and of which the hydrogen gas permeability coefficient under the conditions of a temperature of 80° C. and a relative humidity of 10%, is at most 2.5×10.sup.−9 cm.sup.3.Math.cm/(s.Math.cm.sup.2.Math.cmHg), and the mass reduction rate when being immersed in hot water at 120° C. for 24 hours is at most 15 mass %, wherein the TQ value of a polymer having fluorosulfonyl groups which is a precursor of the polymer having acid-type sulfonic acid groups, is at least 220° C.

To provide an acid-type sulfonic acid group-containing polymer which is excellent in hydrogen gas barrier properties and hot water resistance and which generates less oligomer during production; a liquid composition and a polymer electrolyte membrane comprising this acid-type sulfonic acid group-containing polymer; and a membrane electrode assembly and a polymer electrolyte fuel cell provided with the polymer electrolyte membrane.

This acid-type sulfonic acid group-containing polymer is a polymer which has perfluoromonomer units, no monomer units having a halogen atom other than a fluorine atom, and acid-type sulfonic acid groups, and of which the hydrogen gas permeability coefficient under the conditions of a temperature of 80° C. and a relative humidity of 10%, is at most 2.5×10.sup.−9 cm.sup.3.Math.cm/(s.Math.cm.sup.2.Math.cmHg), and the mass reduction rate when being immersed in hot water at 120° C. for 24 hours is at most 15 mass %, wherein the TQ value of a polymer having fluorosulfonyl groups which is a precursor of the polymer having acid-type sulfonic acid groups, is at least 220° C.

To provide an ion exchange membrane for alkali chloride electrolysis which is a membrane having a high water permeability and being capable of maintaining a low electrolysis voltage while suppressing the amount of water supplied to a cathode chamber to be minimum, and which is capable of forming an aqueous alkali hydroxide solution having a high caustic alkali quality. The ion exchange membrane for alkali chloride electrolysis comprises a layer 12 made of a fluorinated polymer having carboxylic acid functional groups, and a layer 14A and a layer 14B made of a fluorinated polymer having sulfonic acid functional groups, wherein a reinforcing material 20 containing reinforcing threads 22 is disposed between the layer 14A and the layer 14B, the thickness when dried, of the layer 12 is from 9 to 28 μm, the layer 14B includes a layer having an ion exchange capacity of from 1.3 to 2.5 meq/g, the thickness when dried, of the layer 14B is from 6 to 100 μm, the layer 14A includes a layer having an ion exchange capacity of from 0.9 to 1.25 meq/g, and the thickness when dried, of the layer 14A is from 40 to 110 μm.

To provide an ion exchange membrane for alkali chloride electrolysis which is a membrane having a high water permeability and being capable of maintaining a low electrolysis voltage while suppressing the amount of water supplied to a cathode chamber to be minimum, and which is capable of forming an aqueous alkali hydroxide solution having a high caustic alkali quality. The ion exchange membrane for alkali chloride electrolysis comprises a layer 12 made of a fluorinated polymer having carboxylic acid functional groups, and a layer 14A and a layer 14B made of a fluorinated polymer having sulfonic acid functional groups, wherein a reinforcing material 20 containing reinforcing threads 22 is disposed between the layer 14A and the layer 14B, the thickness when dried, of the layer 12 is from 9 to 28 μm, the layer 14B includes a layer having an ion exchange capacity of from 1.3 to 2.5 meq/g, the thickness when dried, of the layer 14B is from 6 to 100 μm, the layer 14A includes a layer having an ion exchange capacity of from 0.9 to 1.25 meq/g, and the thickness when dried, of the layer 14A is from 40 to 110 μm.

Provided is a method for analyzing the metal impurity content that includes passing water to be analyzed through a monolithic organic porous anion exchanger, thereby allowing the monolithic organic porous anion exchanger to capture metal impurities in the water to be analyzed; passing an eluent through the monolithic organic porous anion exchanger which has been allowed to capture metal impurities in the water to be analyzed, to collect an effluent, thereby obtaining a collected eluent containing metal impurities in the water to be analyzed eluted from the monolithic organic porous anion exchanger; and measuring the content of each metal impurity in the collected eluent.