Abstract: A water intake mode passes water through a demineralization chamber of an electrodeionization device to obtain treated water when the electrodeionization device is not energized. A water intake and regeneration mode that, while the electrodeionization device is energized, is operated alternately in the water intake mode and passes water through the demineralization chamber to obtain treated water and water is passed through a concentration chamber and/or an electrode chamber of the electrodeionization device. Water quality of the treated water is measured, and a preset first threshold value is provided for the measured value of the water quality to prevent the water quality from deteriorating below a predetermined value. The water intake and regeneration mode and the water intake mode are switched based on the measured value using the first threshold value as a base point.

Abstract: A water treatment apparatus that can remove persistent organic materials more efficiently is provided. Water treatment apparatus has hypohalogenous acid addition unit that adds hypohalogenous acid to water to be treated that contains organic materials; and ultraviolet ray radiating apparatus that is positioned downstream of hypohalogenous acid addition unit and that radiates ultraviolet rays to the water to be treated to which the hypohalogenous acid has been added.

Abstract: A pure water production system includes a reverse osmosis membrane device; an electric deionized water production device that is disposed downstream of the reverse osmosis membrane device; and a control device that controls a processing condition of the reverse osmosis membrane device. The control device controls a processing condition of the reverse osmosis membrane device such that a removal rate of a specific substance of the electric deionized water production device is equal to or lower than a threshold value, and concentration of the specific substance in the treated water of the electric deionized water production device is equal to or lower than a prescribed value and specific resistance of the treated water of the electric deionized water production device is equal to or higher than a prescribed value.

Abstract: An ultrapure water production system capable of producing ultrapure water from which fine particles have been highly removed and supplying the ultrapure water to a point of use is equipped with at least an ultrafiltration membrane device, and includes: a first organic porous ion exchanger provided at a position downstream of the ultrafiltration membrane device in an ultrapure water supply line for supplying the ultrapure water to the point of use; and a microfiltration membrane device provided, in the ultrapure water supply line, at a position downstream of the first organic porous ion exchanger.

Abstract: A water treatment apparatus for decomposing and removing organic substances in water to be treated includes: a hydrogen peroxide source for storing hydrogen peroxide which is added to the water to be treated; an ultraviolet oxidation device for irradiating ultraviolet light to the water to be treated to which hydrogen peroxide has been added; and a hydrogen peroxide removal device for removing hydrogen peroxide contained in the outlet water from the ultraviolet oxidation device. The hydrogen peroxide removal device includes: an anode and a cathode; and a hydrogen peroxide removal chamber disposed between the anode and the cathode and provided with a metal catalyst with ability of decomposing hydrogen peroxide. A DC current is applied between the anode and cathode.

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 water treatment apparatus that can enhance the efficiency of removing hydrogen peroxide is provided. A water treatment apparatus (pure water production apparatus) has anion removing means that removes anions from water to be treated that contains hydrogen peroxide and the anions; and platinum group catalyst carriers (catalyst tower) that are positioned downstream of anion removing means.

Abstract: Provided are an apparatus for removing boron and a method for removing boron for reducing the boron concentration in water to be treated, and an apparatus and a method for producing pure water wherein the boron concentration is reduced. An apparatus for removing boron includes: a first electrodeionization device to which water to be treated is supplied; an ultraviolet oxidation device to which the water treated by the first electrodeionization device is supplied; an oxide removal device to which the water treated by the ultraviolet oxidation device is supplied; and a second electrodeionization device to which the water treated by the oxide removal device is supplied. A method for removing boron using the apparatus is provided. The oxide removal device is equipped with a platinum group metal catalyst, and the water that has been treated by the oxide removal device has a hydrogen peroxide concentration of less than 1 ppb.

Abstract: As a countermeasure for calcium fluoride scale in reverse osmosis membranes, a water treatment method and apparatus are provided that can add a scale inhibitor at an appropriate addition amount. A water treatment apparatus for treating water to be treated that contains fluorine and calcium by passing the water through at least a reverse osmosis membrane includes pH adjustment means for adjusting the pH of the water to be treated in a supply line, means for measuring the concentration of fluoride ions in the water to be treated and then determining the amount of scale inhibitor to be added by an addition means based on the measured fluoride ion concentration. After the scale inhibitor is added from an addition line, permeate from a permeate line and concentrate from a concentrate line are discharged from the reverse osmosis membrane.

Abstract: A water treatment system includes a reverse osmosis membrane device, an electrodeionization device that is located downstream of the reverse osmosis membrane device, a first heat exchanger that is located upstream of the reverse osmosis membrane device and that adjusts the temperature of the water supplied to the reverse osmosis membrane device according to the temperature of raw water supplied to the water treatment system, and a second heat exchanger that is located between the reverse osmosis membrane device and the electrodeionization device and that cools the water supplied to the electrodeionization device. One of the first heat exchanger and the second heat exchanger is an internal heat exchanger that exchanges heat inside the water treatment system, and the other is an external heat exchanger that exchanges heat with the outside of the water treatment system.

Abstract: The purpose is to provide a pure water production method and apparatus, which make it possible to prevent the increase in an ion load during a pure water production process, improve the efficiency of a biological treatment and reduce the generation amount of pulverized coal in a method for treating oxidation-treated water in which urea is oxidized and decomposed with a hypohalous acid with biological activated carbon. Provided is a pure water production method including: for adding a hypohalous acid to urea-containing water of interest and performing an oxidation treatment of the urea in an oxidation treatment apparatus; and measuring the concentration of residual chlorine in the oxidation-treated water, then adding hydrogen peroxide to the oxidation-treated water depending on the measured concentration of the residual chlorine, and then performing a biological treatment of the hydrogen peroxide-added water with biological activated carbon in a biological treatment apparatus.

Abstract: A particle measuring apparatus is provided that has improved measurement accuracy regardless of particle diameters and that ensures prompt measurement. A particle measuring apparatus has: first and second particle counters that obtain a number of particles that are contained in water that flows in a predetermined section of an ultrapure water production apparatus; and particle number calculation means that calculates the number of the particles that are contained in the water that flows in the predetermined section for each particle diameter range based on measurement results of the first and second particle counters. The first particle counter and the second particle counter have different counting efficiencies.

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 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.

Abstract: A urea treatment apparatus for treating urea in a water to be treated includes a first reaction tank in which urea in the water to be treated is treated; a first addition means connected to the first reaction tank or to a first piping connected to the first reaction tank and supplying the water to be treated to the first reaction tank, for adding a bromide salt and a chlorine-based oxidation agent to the water to be treated; a second reaction tank in which a residual urea in a first treated water treated by the first reaction tank is treated, a second addition means connected to the second reaction tank or to a second piping connected to the second reaction tank and supplying the first treated water to the second reaction tank, for adding a chlorine-based oxidation agent or a mineral acid to the first treated water.

Abstract: An ultrapure water production system capable of producing ultrapure water from which fine particles have been highly removed and supplying the ultrapure water to a point of use is equipped with at least an ultrafiltration membrane device, and includes: a first organic porous ion exchanger provided at a position downstream of the ultrafiltration membrane device in an ultrapure water supply line for supplying the ultrapure water to the point of use; and a microfiltration membrane device provided, in the ultrapure water supply line, at a position downstream of the first organic porous ion exchanger.

Abstract: A water treatment apparatus for decomposing and removing organic substances in water to be treated includes: a hydrogen peroxide source for storing hydrogen peroxide which is added to the water to be treated; an ultraviolet oxidation device for irradiating ultraviolet light to the water to be treated to which hydrogen peroxide has been added; and a hydrogen peroxide removal device for removing hydrogen peroxide contained in the outlet water from the ultraviolet oxidation device. The hydrogen peroxide removal device includes: an anode and a cathode; and a hydrogen peroxide removal chamber disposed between the anode and the cathode and provided with a metal catalyst with ability of decomposing hydrogen peroxide. A DC current is applied between the anode and cathode.

Abstract: A urea treatment apparatus for treating urea in a water to be treated includes a first reaction tank in which urea in the water to be treated is treated; a first addition means connected to the first reaction tank or to a first piping connected to the first reaction tank and supplying the water to be treated to the first reaction tank, for adding a bromide salt and a chlorine-based oxidation agent to the water to be treated; a second reaction tank in which a residual urea in a first treated water treated by the first reaction tank is treated, a second addition means connected to the second reaction tank or to a second piping connected to the second reaction tank and supplying the first treated water to the second reaction tank, for adding a chlorine-based oxidation agent or a mineral acid to the first treated water.

Abstract: A water treatment management apparatus used for monitoring and evaluating water supplied to a water treatment system such as an ultrapure water production system and performing appropriate management of operation of the water treatment system includes: a pure water production unit for evaluation to which water to be supplied to the water treatment system is supplied as target water, the pure water production unit for evaluation including a TOC removal apparatus for performing a unit operation of removing total organic carbon (TOC) components; and measuring means for measuring TOC concentration at a plurality of measurement points in the pure water production unit for evaluation, the plurality of the measurement points including an inlet and an outlet of the pure water production unit for evaluation.

Abstract: A database stores inventory status information indicating the inventory status of parts and delivery status information indicating the delivery status of the parts, and a part preparation device acquires part identification information indicating a part that is needed, required quantity information indicating the quantity of parts needed, and required timing information indicating when the part is needed, and selects a securement site for securing the required part based on the part identification information, required quantity information, required timing information that were acquired, as well as on inventory status information and delivery status information that are stored in the database.