Abstract: An exhaust gas treatment facility includes: a combustion chamber for combustion-treating an exhaust gas; a nozzle for letting water flow along an inner wall surface of the combustion chamber; a water-feeding line for supplying water to the nozzle; a primary gas-cleaning chamber; a scrubber; and the like. The water-feeding line has a pipe, a pump, and pipes. An alkali-adding apparatus is provided on the pipe on an upstream side of the pump. The alkali-adding apparatus is controlled so as to regulate a detected pH by a pH meter to be 10 or higher.

Abstract: A pure water production method for producing pure water by decarboxylating water to be treated under acidic conditions and then deionizing the result by using a reverse osmosis membrane separation device, the pH of inflow water flowing into the reverse osmosis membrane separation device and the water quality of permeated water of the reverse osmosis membrane separation device being measured, and the pH of the inflow water being adjusted on the basis of the measured pH and water quality so that the water quality of the permeated water is within a prescribed range, wherein the pH of the inflow water is changed by a predetermined width, and an operation condition adjusting step is performed for adjusting the pH of the inflow water by comparing the(average value before the water quality change average value after the water quality change.

Abstract: Provided is a method for controlling a pH to a neutral range (pH 6 to 8) by adding an alkali or an acid to decarbonated water, including controlling the amount of the alkali or the acid added using an electrical conductivity meter. The decarbonated water is, for example, water obtained by decarbonating industrial water or groundwater so that the concentration of carbonic acid is 10 ppm or less. The method may further have a step of producing pure water by RO treatment of the decarbonated water with a pH adjusted to 6 to 8 by the pH control.

Abstract: Provided is a method for treating water containing a low-molecular-weight organic substance which enables the low-molecular-weight organic substance to be removed with certainty at a sufficient level without subjecting the water to a biological treatment. A method for treating water containing a low-molecular-weight organic substance, the method comprising passing raw water to a high-pressure reverse-osmosis-membrane separation device, the raw water containing a low-molecular-weight organic substance having a molecular weight of 200 or less at a concentration of 0.5 mgC/L or more, wherein an amount of brine discharged from a reverse-osmosis-membrane module (5a) disposed at an end of a final stage of the high-pressure reverse-osmosis-membrane separation device is 2.1 m3/(m2·D) or more.

Abstract: A water treatment chemical for a membrane, being is a water treatment chemical for preventing membrane contamination caused by an organic compound having a phenolic hydroxy group and including an organic amine having two or more nitrogen atoms and having five or more carboxyl groups or four or more phosphate groups. A membrane treatment method including adding the water treatment chemical for a membrane to water to be treated which contains an organic compound having a phenolic hydroxy group and then subjecting the water to be treated to membrane separation treatment.

Abstract: The present invention provides an apparatus and method for producing ultrapure water of extremely high purity that sufficiently meets the requirement for its quality at low production cost with reduced footprint. The apparatus for producing ultrapure water includes a pretreatment system, a primary water purification system, and a subsystem, wherein the primary water purification system includes a high-pressure reverse osmotic membrane separation unit, a degassing unit, an ultraviolet oxidation unit, and an ion-exchange unit in this order.

Abstract: Provided is a method for controlling a pH to a neutral range (pH 6 to 8) by adding an alkali or an acid to decarbonated water, including controlling the amount of the alkali or the acid added using an electrical conductivity meter. The decarbonated water is, for example, water obtained by decarbonating industrial water or groundwater so that the concentration of carbonic acid is 10 ppm or less. The method may further have a step of producing pure water by RO treatment of the decarbonated water with a pH adjusted to 6 to 8 by the pH control.

Abstract: The present invention provides an apparatus and method for producing ultrapure water of extremely high purity that sufficiently meets the requirement for its quality at low production cost with reduced footprint. The apparatus for producing ultrapure water includes a pretreatment system, a primary water purification system, and a subsystem, wherein the primary water purification system includes a high-pressure reverse osmotic membrane separation unit, a degassing unit, an ultraviolet oxidation unit, and an ion-exchange unit in this order.

Abstract: A method for producing ultrapure water includes supplying raw water (industrial water, tap water, well water, or used ultrapure water discharged from semiconductor plants) to a pretreatment system for treating the raw water to produce water, supplying the water to a primary water purification system having a reverse osmosis membrane separation unit to produce a primarily purified water, and supplying the primarily purified water to a secondary purification system to produce ultrapure water.

Abstract: Provided is a method for treating water containing a low-molecular-weight organic substance which enables the low-molecular-weight organic substance to be removed with certainty at a sufficient level without subjecting the water to a biological treatment. A method for treating water containing a low-molecular-weight organic substance, the method comprising passing raw water to a high-pressure reverse-osmosis-membrane separation device, the raw water containing a low-molecular-weight organic substance having a molecular weight of 200 or less at a concentration of 0.5 mgC/L or more, wherein an amount of brine discharged from a reverse-osmosis-membrane module (5a) disposed at an end of a final stage of the high-pressure reverse-osmosis-membrane separation device is 2.1 m3/(m2·D) or more.

Abstract: Disclosed is a treatment apparatus capable of inhibiting growth of microorganisms and carrying out long-term stable treatment in an activated carbon tower and a reverse osmosis membrane separation device during processes including activated carbon treatment and RO membrane separation treatment of a later step in a system for manufacturing ultrapure water used in an electronic device factory.

Abstract: When recovering water by performing a reverse-osmosis-membrane separation treatment on wastewater containing a cationic surfactant such as process wastewater from the electronics industry, high-quality treated water is obtained consistently over the long term while preventing blockage of the reverse-osmosis membrane caused by the cationic surfactant. A reverse-osmosis-membrane separation treatment is performed using a first reverse-osmosis-membrane separation device (3) on wastewater containing a cationic surfactant such as process wastewater from the electronics industry after first adjusting the same to a pH of 3-5, a reverse-osmosis-membrane separation treatment is performed using a second reverse-osmosis-membrane separation device (4) on permeated water from the first reverse-osmosis-membrane separation device (3) after first adjusting the same to a pH of 6.5-10.5, and the permeated water from the second reverse-osmosis-membrane separation device (4) is recovered as treated water.

Abstract: A method and an apparatus for treating water containing boron that enable boron to be removed from water containing boron with efficiency by using an RO device and an ion-exchange device in the acidic to neutral pH range in which an RO film has high resistance to degradation are provided. A method for treating water containing boron, comprising: a step in which water containing boron is passed through a high-pressure reverse osmosis membrane device; and a step in which the water passed through the device is subsequently treated by an ion-exchange device. An apparatus for treating water containing boron comprising: a high-pressure reverse osmosis membrane device into which water containing boron is fed; and an ion-exchange device through which water that permeated through the high-pressure reverse osmosis membrane device is passed.

Abstract: Provided is an ultrapure water producing apparatus equipped with fewer reverse osmosis membrane separation units. The ultrapure water producing apparatus includes a primary water purification system 2 and a subsystem 3 configured to treat water treated by the primary water purification system 2. A reverse osmosis membrane separation unit is provided in at least the primary water purification system 2. The reverse osmosis membrane separation unit installed in the primary water purification system 2 is a high-pressure reverse osmosis membrane separation unit installed in a single stage. The high-pressure reverse osmosis membrane separation unit has a standard operating pressure of 5.52 MPa, a pure water flux of 0.5 m3/m2·D or more, and a NaCl rejection of 99.5% or more (32,000 mg/L NaCl).

Abstract: In an ultrapure water producing method, a pre-treatment system treats raw water supplied from a raw water storage tank. A heat exchanger adjusts the treated water to a predetermined temperature before the water is supplied to a first bio-treatment means which is further connected to a second bio-treatment means. The second bio-treatment means is connected to a microbial body separation apparatus and, after treatments are performed in those apparatuses, the result is supplied as treated water to a primary pure water apparatus. Before the second bio-treatment means, a second supply mechanism is provided for adding a nitride source as a nutrient source and oxidizing agent (bactericidal agent). According to the ultrapure water producing method, urea in raw water can be removed to a high degree.

Abstract: Ultrapure water of high purity having extremely low TOC concentration is produced by efficiently degrading urea in raw water by biological activated carbon treatment even when the raw water contains ammonium nitrogen. The ultrapure water production method, where raw water is treated in a primary pure water system, and then the resulting water is treated in a subsystem, contains a step of treating pretreated water with chlorine based oxidizer added by a biological treatment means installed upstream to the subsystem. Chlorine based oxidizer is added so that the chlorine based oxidizer concentration is 5 times or more than the ammonium nitrogen concentration of water treated in the biological treatment means in terms of Cl2.

Abstract: A water treatment method and a method for producing ultrapure water are provided in which urea in raw water is sufficiently decomposed, and an organism (bacterial cells) in biological treatment is prevented from flowing downstream. In a water treatment method for performing biological treatment of raw water containing urea, a carbon source is added to the raw water, and the raw water is then supplied to biological treatment means 1 and 2 having a fixed bed formed of an organism-supporting carrier to perform the biological treatment. The biological treatment after the addition of the carbon source to the raw water improves the efficiency of decomposition and removal of urea. The biological treatment means using a fixed bed formed of an organism-supporting carrier decreases the number of bacterial cells flowing downstream.

Abstract: In an ultrapure water producing method, a pre-treatment system treats raw water supplied from a raw water storage tank. A heat exchanger adjusts the treated water to a predetermined temperature before the water is supplied to a first bio-treatment means which is further connected to a second bio-treatment means. The second bio-treatment means is connected to a microbial body separation apparatus and, after treatments are performed in those apparatuses, the result is supplied as treated water to a primary pure water apparatus. Before the second bio-treatment means, a second supply mechanism is provided for adding a nitride source as a nutrient source and oxidizing agent (bactericidal agent). According to the ultrapure water producing method, urea in raw water can be removed to a high degree.

Abstract: In a water treatment method, raw water supplied from a water supply reservoir for reserving the raw water is biologically treated by a biological treatment means before being supplied to a primary pure water apparatus. Thereafter, urea or a urea derivative and/or an ammoniacal nitrogen source (NH3—N) are added before the biological treatment means. In such a treatment flow, it is preferred that a reduction treatment means is provided after the biological treatment means and before the primary pure water apparatus. According to the water treatment method, the TOC, in particular urea, in the raw water can highly be decomposed.

Abstract: A urea removal capability is increased in a water treatment method of introducing raw water containing organic substances, specially, urea to a reaction tank, adding water-soluble bromide salt and an oxidizing agent to perform an oxidation treatment on the urea, subsequently, performing a bio-treatment by a bio-treatment means. According to the water treatment method, TOC, particularly, urea in the raw water can be highly decomposed.