Abstract: Provided are a method for supplying water of specified concentration, including: a step of adding at least two liquids, a conductive first liquid and a non-conductive second liquid, to ultrapure water to produce water of specified concentration containing a first liquid-component and a second liquid-component at specified concentrations, in which a mixed solution in which the first liquid and the second liquid are mixed at a specified mixing ratio in advance is prepared; and the mixed solution is added to the ultrapure water so that a conductivity or specific resistance of the ultrapure water after the addition satisfies a specified value, and an apparatus therefor.

Abstract: The dilute chemical solution supply device 1 comprises: a dilute chemical solution preparation unit 2 that prepares a dilute chemical solution W1; a reservoir 3 for the prepared dilute chemical solution; a dilute chemical solution adjustment/supply mechanism 4 that supplies, as washing water W2, the dilute chemical solution W1 stored in the reservoir 3 to a plurality of single-wafer type washers 5A, 5B, and 5C; and a return mechanism that is connected to each of the single-wafer type washers 5A, 5B, and 5C and refluxes excess water from the single-wafer type washers to the reservoir 3. According to such a dilute chemical solution supply device, it is possible to accurately adjust the concentration of the solute of the dilute chemical solution and suppress the discharge of excess water, and the dilute chemical solution supply device is thus suitable for washing of wafers, etc.

Abstract: A pH-adjusted water production device has a configuration in which a platinum group metal support resin column, a membrane-type degassing device, and a gas dissolving membrane device are provided on an ultra-pure water supply line, and a pH-adjuster injection device is provided between the platinum group metal support resin column and the membrane-type degassing device. An inert gas source is connected to the gas phase side of the membrane-type degassing device while an inert gas source is connected also on the gas phase side of the gas dissolving membrane device, and a discharge line communicates with the gas dissolving membrane device.

Abstract: There is provided an apparatus for removing fine particles having membranes for removing fine particles in a liquid, wherein a microfiltration membrane or ultrafiltration membrane having a positive charge and a microfiltration membrane or ultrafiltration membrane having a negative charge are arranged in series. There is also provided a method for removing fine particles using the apparatus. Liquids may be passed through the membrane having a negative charge and the membrane having a positive charge in order; thereby, extrafine particles having a particle size of 50 nm or smaller, especially of 10 nm or smaller, in the liquids can be removed highly. The liquid passing may be carried out in the order reverse thereto.

Abstract: Provided are a method for supplying water of specified concentration, including: a step of adding at least two liquids, a conductive first liquid and a non-conductive second liquid, to ultrapure water to produce water of specified concentration containing a first liquid-component and a second liquid-component at specified concentrations, in which a mixed solution in which the first liquid and the second liquid are mixed at a specified mixing ratio in advance is prepared; and the mixed solution is added to the ultrapure water so that a conductivity or specific resistance of the ultrapure water after the addition satisfies a specified value, and an apparatus therefor.

Abstract: The ultrapure-water production system includes an auxiliary treatment apparatus and a dead-end filtration apparatus. The auxiliary treatment apparatus treats water such that the number of microparticles present in water treated by the auxiliary treatment apparatus is 800 to 1200 particles/mL. The dead-end filtration apparatus includes a filtration membrane that is a microfiltration membrane having pores formed in the surface of the membrane at an opening ratio of 50% to 90% with a size of 0.05 to 1 ?m, and having a thickness of 0.1 to 1 mm, or an ultrafiltration membrane having pores formed in the surface of the membrane with a size of 0.005 to 0.05 ?m, the number of the pores being 1E13 to 1E15 pores/m2, the ultrafiltration membrane having a thickness of 0.1 to 1 mm and a transmembrane pressure of 0.02 to 0.10 MPa at a permeation flux of 10 m3/m2/d.

Abstract: A wet cleaning apparatus that cleans an item with carbon dioxide gas-dissolved water produced by dissolving carbon dioxide gas in ultrapure water, the wet cleaning apparatus including: a carbon dioxide gas-dissolving unit that dissolves carbon dioxide gas in ultrapure water; a cleaning unit that cleans an item, the cleaning unit receiving carbon dioxide gas-dissolved water fed from the carbon dioxide gas-dissolving unit; and a filtration membrane module disposed on a pipe through which the carbon dioxide gas-dissolved water is fed to the cleaning unit, the filtration membrane module being filled with a porous membrane including a cationic functional group.

Abstract: An ion exchange device is used that includes an anion exchange tank, a cation exchange tank and a tower body side portion, in which the anion exchange tank and the cation exchange tank are allowed to communicate by communication means that is arranged around the outside of the anion exchange tank and the cation exchange tank. The ion exchange device also includes supply/discharge pipes for supplying or discharging a liquid to or from an upper portion and a lower portion of the anion exchange tank, and supply/discharge pipes for supplying or discharging a liquid to or from an upper portion and a lower portion of the cation exchange tank. A water collection/distribution member that allows water to pass but prevents passage of an ion-exchange resin is provided in a flat plate.

Abstract: In a subsystem or water-feed path located upsteam of a use point in an ultrapure water production/supply process, fine particles having a particle diameter of 50 nm or less, in particular 10 nm or less are highly removed. A device for removing fine particles in water has a membrane filtration device including a microfiltration membrane or an ultrafiltration membrane having a weak cationic functional group. The microfiltration membrane or the ultrafiltration membrane having a weak cationic functional group is preferred to have a polyketone film with the weak cationic functional group. Negatively-charged particles in water are adsorbed by the weak cationic functional group and can thus be removed.

Abstract: Provided is an ultrapure water production apparatus capable of producing high-quality ultrapure water from which microparticles have been removed at a high level. An ultrapure water production apparatus comprising a subsystem that produces ultrapure water from primary pure water, the subsystem including a membrane unit disposed at the end of the subsystem, wherein the membrane unit is constituted by a plurality of membrane devices arranged in series, the first of the membrane devices being a UF membrane device, an MF membrane device, or an RO membrane device, the last of the membrane devices being a UF membrane device or an MF membrane that is not modified with an ion-exchange group.

Abstract: Provided is a desalting device which includes a tower body and a bulge portion bulging downward therefrom, and which prevents uneven flow and causes no dead space within the tower body. The desalting device includes a tower body having a bulge portion 1b bulging downward at a bottom portion thereof, an ion-exchange resin packed in the tower body, and a plurality of strainers 3 for collecting water being arranged within the bulge portion 1b. The strainers are arranged only in a central region of an inside of the bulge portion excluding an outer peripheral portion of the bulge portion.

Abstract: Provided is a desalting device which includes a tower body and a bulge portion bulging downward therefrom, and which prevents uneven flow and causes no dead space within the tower body. The desalting device includes a tower body having a bulge portion 1b bulging downward at a bottom portion thereof, an ion-exchange resin packed in the tower body, and a plurality of strainers 3 for collecting water being arranged within the bulge portion 1b. The strainers are arranged only in a central region of an inside of the bulge portion excluding an outer peripheral portion of the bulge portion.

Abstract: There is provided an apparatus and method for fluid mixing, which enable mixing efficiency to be enhanced and enable a lodging impurity to be easily removed. A liquid, powder, or the like is added from a pipe 2 to a liquid flowing in a pipe 1, and the resultant liquid then passes a plurality of half-open ball valves 3A to 3C, thereby being mixed. The ball valves 3A to 3C each have angular difference ? in the position around the axis thereof. Sufficient mixing can be performed without preparing a static mixer having a complicated structure. In addition, in the case where clogging due to an impurity occurs, the valve is opened with the result that the impurity can be released.