Abstract: 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.

Abstract: 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.

Abstract: Time until a conductivity meter is ready to measure a conductivity after an electric decationizing apparatus starts is shortened. Water to be treated that contains cations and anions is supplied to the electric decationizing apparatus while applying a first voltage to the electric decationizing apparatus, and decationized water is generated. Next, the decationized water that is generated by the electric decationizing apparatus is supplied to the conductivity meter in order to measure conductivity of the decationized water. Before the first voltage is applied to the electric decationizing apparatus and before the conductivity meter begins measuring the conductivity of the decationized water, a second voltage that is lower than the first voltage is applied to the electric decationizing apparatus in a state in which the electric decationizing apparatus is charged with water to be treated.

Abstract: The present invention provides an electric device for producing deionized water comprising: desalting chamber (4) defined by at least two ion-exchange membranes (1, 2) and filled with an ion exchanger; first concentration chamber (5a) positioned adjacent to one side of the desalting chamber with one of the ion-exchange membranes therebetween; second concentration chamber (5b) positioned adjacent to the other side of the desalting chamber with another of the ion-exchange membranes therebetween; and a pair of electrode chambers (6a, 6b) with one electrode chamber being disposed at the outer side of first concentration chamber (5a) and the other electrode chamber being disposed at the outer side of second concentration chamber (5b), wherein the electric device for producing deionized water is provided with: main body part (20) formed to include desalting chamber (4), concentration chambers (5a, 5b), and electrode chambers (6a, 6b); a pair of fixing plates (9a, 9b) disposed in such a way that main body part (20)

Abstract: The present invention provides an electric device for producing deionized water comprising: desalting chamber (4) defined by at least two ion-exchange membranes (1, 2) and filled with an ion exchanger; first concentration chamber (5a) positioned adjacent to one side of the desalting chamber with one of the ion-exchange membranes therebetween; second concentration chamber (5b) positioned adjacent to the other side of the desalting chamber with another of the ion-exchange membranes therebetween; and a pair of electrode chambers (6a, 6b) with one electrode chamber being disposed at the outer side of first concentration chamber (5a) and the other electrode chamber being disposed at the outer side of second concentration chamber (5b), wherein the electric device for producing deionized water is provided with: main body part (20) formed to include desalting chamber (4), concentration chambers (5a, 5b), and electrode chambers (6a, 6b); a pair of fixing plates (9a, 9b) disposed in such a way that main body part (20)