Abstract: A water treatment apparatus for removing dissolved oxygen contained in water to be treated includes: an anode; a cathode; and a dissolved oxygen removal chamber which is located between the anode and the cathode and filled with an ion exchanger. At least a portion of the ion exchanger filled in the dissolved oxygen removal chamber is an ion exchanger on which a metal catalyst is supported. The ion exchanger on which the metal catalyst is supported is filled in a single bed configuration in at least a portion of the dissolved oxygen removal chamber. A DC current is applied between the anode and the cathode.

Abstract: A measured value acquisition unit acquires measured values for each of a plurality of measurement items measured by one or more measuring instruments that measure the plurality of measurement items for an electrodeionization water production apparatus, a calculating unit calculates individual predicted product lifespans based on each of the measured values acquired by the measured value acquisition unit, a prediction unit predicts as the predicted product lifespan of the electrodeionization water production apparatus the shortest individual predicted product lifespan among a plurality of individual predicted product lifespans calculated by the calculation unit, and an output unit outputs information according to the predicted product lifespan predicted by the prediction unit.

Abstract: An electrodeionization device includes a deionization chamber partitioned by a pair of ion exchange membranes; and a concentration chamber disposed adjacent to the deionization chamber via the ion exchange membrane which is disposed on a side facing a cathode. When representing a particle size of 0.1 mm or more and 0.4 mm or less by small particle size; and a particle side exceeding 0.4 mm by large particle size, a large particle size layer consisting of an ion exchange resin of large particle size, and a mixed particle size layer in which ion exchange resins of large particle size and small particle size are mixed are arranged in the concentration chamber along a flow direction of water to be treated. At least a part of the ion exchange resin filled in the concentration chamber is a cation exchange resin.

Abstract: A method for operating a deionized water production system for producing deionized water from water to be treated using an electrodeionization device includes: providing a water intake mode, in which the water to be treated is passed through a demineralization chamber of the electrodeionization device without energizing the electrodeionization device to obtain treated water, and a water intake and regeneration mode, which is operated alternately with the water intake mode and in which treated water is passed through the demineralization chamber to obtain treated water while the electrodeionization device is energized, and water is further passed through at least one of a concentration chamber and an electrode chamber of the electrodeionization device; and operating the electrodeionization device such that the operation time of the water intake mode is 1.5 to 6.4 times the operation time of the water intake and regeneration mode.

Abstract: A water treatment apparatus for removing dissolved oxygen contained in water to be treated includes: an anode; a cathode; and a dissolved oxygen removal chamber which is located between the anode and the cathode and filled with an ion exchanger. At least a portion of the ion exchanger filled in the dissolved oxygen removal chamber is an ion exchanger on which a metal catalyst is supported. The ion exchanger on which the metal catalyst is supported is filled in a single bed configuration in at least a portion of the dissolved oxygen removal chamber. A DC current is applied between the anode and the cathode.

Abstract: A hydrogen peroxide removing apparatus for removing hydrogen peroxide contained in water to be processed includes: anode and cathode; and hydrogen peroxide removal chamber provided between anode and cathode and at least partially filled with a metal catalyst with hydrogen peroxide decomposition ability, wherein a DC voltage is applied between anode and cathode.