Abstract: Provided are a method and system for measuring hydrogen peroxide concentration in sample water collected from a prescribed position in a water treatment process and includes: collecting the sample water; measuring a concentration of a dissolved oxygen in the sample water or a treated water obtained by treating the sample water with the hydrogen peroxide decomposing device by first and second dissolved oxygen concentration measuring analyzers to obtain a corrected value that is a difference between the two dissolved oxygen concentration values; measuring the concentration of the dissolved oxygen in the sample and treated water by the first and second dissolved oxygen concentration measuring analyzers, respectively, and obtaining a measured value that is a difference between the dissolved oxygen concentration values; and calculating a corrected concentration of hydrogen peroxide from the measured value obtained during the measured value obtaining and the corrected value obtained during the corrected value obtai

Abstract: A method for purifying a nonaqueous liquid substance includes: filling a cartridge container with a macroporous or porous type ion exchange resin in a water-wet state to obtain an ion exchange resin-filled cartridge filled with the macroporous or porous type ion exchange resin before water content reduction; reducing a water content of the macroporous or porous type ion exchange resin in the cartridge container until a water content (A) of the macroporous or porous type ion exchange resin after water content reduction becomes 90 to 97% of a water content (B) of the macroporous or porous type ion exchange resin in a saturated equilibrium state; an initial blowing step of allowing the nonaqueous liquid substance before being purified to pass inside the cartridge container filled with the macroporous or porous type ion exchange resin after water content reduction and discharging an initial blow effluent from inside of the cartridge container; and purification.

Abstract: A diluted solution production method of the present invention is a diluted solution production method of producing a diluted solution of a second liquid by adding the second liquid a first liquid, the method including feeding the first liquid to a first pipe; and controlling pressure in a tank that stores the second liquid to add, through the second pipe that connects the tank to the first pipe, the second liquid to the first liquid in the first pipe. Adding the second liquid includes measuring a flow rate of the first liquid or the diluted solution that flows through the first pipe; measuring a component concentration of the diluted solution; and controlling the pressure in the tank, based on the measured values of the flow rate and the component concentration, so as to adjust the component concentration of the diluted solution to a specified value.

Abstract: Provided is a method for producing a chelate resin, wherein a highly pure treatment liquid can be obtained by reducing the amount of metal impurities in a to-be-treated liquid containing metal impurities. The method for producing a chelate resin comprises a purification step for purifying a to-be-purified chelate resin by bringing the chelate resin into contact with at least 5 wt % of a mineral acid solution containing 1 mg/L or less of metal impurities, wherein the total amount of metal impurities eluted when 3 wt % of hydrochloric acid is passed through the purified chelate resin in an amount equal to 25 times the amount of the chelate resin by volume ratio is 5 ?m/mL-R or less.

Abstract: The analyzing method for quantifying urea in a sample solution includes: a pretreatment step of pretreating the sample solution with at least one of a membrane device including a reverse osmosis membrane and an ion exchange device including an ion exchanger; and an analyzing step of analyzing a target substance in the pretreated sample solution. The analyzing step is based on, for example, flow injection analysis (FIA), and includes a step of quantifying the target substance by measuring the absorbance of a liquid containing a substance generated by reacting the target substance with a reagent.

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: A method for purifying an organic solvent, comprising contacting an organic solvent containing polyvalent metal ions with a monolithic organic porous ion exchanger. According to the present invention, a method for purifying an organic solvent can be provided, wherein a high rate of removing polyvalent metal ions in an organic solvent is achieved.

Abstract: A flocculation and sedimentation apparatus has: sedimentation tank that causes flocs in raw water to be sedimented and separated; sludge concentration tank that is surrounded by sedimentation tank and that collects and concentrates the flocs; and raw water supply mechanism having center line that passes through sludge concentration tank, wherein raw water supply mechanism rotates about center line and supplies the raw water to sedimentation tank. Raw water supply mechanism includes: raw water introducing portion that is located on center line and to which the raw water is introduced, raw water supply port that is open at a lower portion of an inner space of sedimentation tank and that supplies the raw water to sedimentation tank, and pipe portion that communicates both with raw water introducing portion and with raw water supply port and that extends above sludge concentration tank in a direction away from center line.

Abstract: Provided is a method for forming aerobic granules in which a semibatch reactor for forming granules is used, the method involving repeatedly carrying out an inflowing step for causing organic-matter-containing wastewater that includes organic matter to flow in, a biological treatment step for biologically treating substances to be treated in the organic-matter-containing drainage water by using microbial sludge, a settling step for allowing the microbial sludge to settle out, and a discharge step for discharging biologically treated water which has been biologically treated, wherein the reaction time is adjusted such that the value obtained by dividing the total cycle time by the reaction time and multiplying the resulting quotient by the ratio of the MLSS concentration to the BOD load charged into the semibatch reactor is within a range of 0.05 to 0.25 kgBOD/kgMLSS/d, and the sludge is drawn such that the sludge retention period is 5 to 25 days.

Abstract: Provided is a method of washing a hollow fiber membrane device which can efficiently remove fine particles while limiting the impact of an ultrapure water production system on the starting time. The method of washing a hollow fiber membrane device includes washing a hollow fiber membrane device with an alkaline aqueous solution before the hollow fiber membrane device is installed in an ultrapure water production system. The hollow fiber membrane device is washed by means of a washing device that is different from the ultrapure water production system.

Abstract: The level of cleanliness of a hollow fiber membrane device is evaluated before it is installed in an ultrapure water production system. A method of evaluating the level of cleanliness of the hollow fiber membrane device includes capturing fine particles in permeating water by means of a first filter membrane, wherein the permeating water is ultrapure water that permeates through the hollow fiber membrane device before the hollow fiber membrane device is installed in an ultrapure water production system; and analyzing the fine particles that are captured by the filter membrane.

Abstract: An ion exchanger filled cartridge accommodated inside an accommodating container of a metal removing column and in which an ion exchanger is filled is provided. The ion exchanger filled cartridge includes a cylinder portion, an upper lid in which a through hole for a liquid to be treated is formed and which is provided on an upper end of the cylinder portion, a lower lid in which a through hole for a treated liquid is formed and which is provided on a lower end of the cylinder portion, an insertion pipe connected to the lower lid, having an O-ring attached to an outer side, and inserted into a treated liquid discharge pipe provided on a bottom portion of the accommodating container of the metal removing column, and the ion exchanger filled inside the cylinder portion.

Abstract: In an insoluble material-generating apparatus, an iron salt and/or an aluminum salt, and a cationic polymer flocculant, are added to waste water containing dissolved substances to generate insoluble material. To the insoluble material-containing waste water, an anionic polymer flocculant is added, after which the waste water containing the anionic polymer flocculant and the insoluble material is stirred in a granulating flocculation precipitation tank, the insoluble material is granulated, and solid-liquid separation of the generated granulated material is performed to obtain treated water. The amount of the iron salt or the aluminum salt added is an iron or aluminum concentration of at least 0.4 mmol/L, and the cationic polymer flocculant and the anionic polymer flocculant are added so that the product of the cationic polymer flocculant concentration and the cationic group percentage is equal to or less than the product of the anionic polymer flocculant concentration and the anionic group percentage.

Abstract: A centrifugal filtration device is provided. The centrifugal filtration device has filtration membrane that filtrates liquid; cartridge that supports filtration membrane and that forms liquid chamber together with filtration membrane, wherein liquid chamber holds the liquid therein; and rotating member that rotates around rotation center and that supports cartridge such that filtration membrane is positioned outward of liquid chamber with respect to rotation center. Rotating member has a path that is connected to liquid chamber, and at least a part of a liquid contact part of the path that is in contact with the liquid is formed of titanium or a titanium alloy.

Abstract: A diluted solution production method of the present invention is a diluted solution production method of producing a diluted solution of a second liquid by adding the second liquid a first liquid, the method including feeding the first liquid to a first pipe; and controlling pressure in a tank that stores the second liquid to add, through the second pipe that connects the tank to the first pipe, the second liquid to the first liquid in the first pipe. Adding the second liquid includes measuring a flow rate of the first liquid or the diluted solution that flows through the first pipe; measuring a component concentration of the diluted solution; and controlling the pressure in the tank, based on the measured values of the flow rate and the component concentration, so as to adjust the component concentration of the diluted solution to a specified value.

Abstract: The water outlet of a subsystem that includes an ultraviolet oxidation device and the water inlet of each substrate treatment device are connected to each other via a main pipe. A hydrogen peroxide removal device is installed between the ultraviolet oxidation device of the subsystem and a non-regenerative ion-exchange device. In addition, a carbon dioxide supply device is installed at the middle of a pipe that branches from the water outlet of the subsystem to reach the substrate treatment device. According to an aspect, the hydrogen peroxide removal device is filled with a platinum-group metal catalyst. Thus, ultrapure water passed through the ultraviolet oxidation device is used as a base to produce carbonated water in which the concentration of hydrogen peroxide dissolved therein is limited to 2 ?g/L or less and to which carbon dioxide is added to adjust resistivity to be within the range of 0.03 to 5.0 M?·cm.

Abstract: Provided is a method for producing a one-liquid stabilized hypobromous acid composition which contains substantially no bromate ions, has excellent sterilization performance, exhibits almost no corrosiveness relative to metals, and displays excellent storage stability. This method for producing the stabilized hypobromous acid composition includes a step in which a reaction is induced by adding, under an inert gas atmosphere, bromine to a mixed solution including water, an alkali hydroxide, and sulfamic acid, wherein the proportion of bromine added is not more than 25 wt % relative to the total weight of the composition.

Abstract: A granule-forming method using a semi-batch reaction tank, wherein: operation cycles of a first operation cycle for performing a biological treatment step at a first sludge load and after the first operation cycle, a second operation cycle for performing the biological treatment step at a second sludge load are performed repeatedly; the first sludge load is set so that the soluble BOD concentration in the semi-batch reaction tank at the time of completion of the biological treatment step of the first operation cycle does not decrease to a threshold value or less; and the second sludge load is set so that the soluble BOD concentration in the semi-batch reaction tank at the time of completion of the biological treatment step of the second operation cycle is at or below the threshold value.

Abstract: A reverse osmosis membrane treatment system is provided with a first reverse osmosis membrane treatment device wherein water to be treated is passed through a first reverse osmosis membrane to obtain first permeate water and first concentrated water, and at least a second reverse osmosis membrane treatment device, wherein the first permeate water is passed through a second reverse osmosis membrane to obtain second permeate water and second concentrated water. The permeation flux per 1 MPa of effective pressure for the second reverse osmosis membrane is lower than the permeation flux per 1 MPa of effective pressure for the first reverse osmosis membrane, and the permeation flux per 1 MPa of effective pressure for the second reverse osmosis membrane is 0.5 m3/m2/d or less.

Abstract: The water outlet of a subsystem that includes an ultraviolet oxidation device and the water inlet of each substrate treatment device are connected to each other via a main pipe. A hydrogen peroxide removal device is installed between the ultraviolet oxidation device of the subsystem and a non-regenerative ion-exchange device. In addition, a carbon dioxide supply device is installed at the middle of a pipe that branches from the water outlet of the subsystem to reach the substrate treatment device. According to an aspect, the hydrogen peroxide removal device is filled with a platinum-group metal catalyst. Thus, ultrapure water passed through the ultraviolet oxidation device is used as a base to produce carbonated water in which the concentration of hydrogen peroxide dissolved therein is limited to 2 ?g/L or less and to which carbon dioxide is added to adjust resistivity to be within the range of 0.03 to 5.0 M?·cm.