JP5441714B2 - Pure water production method and apparatus, ozone water production method and apparatus, and cleaning method and apparatus - Google Patents

Description

The present invention relates to a pure water production method and apparatus, an ozone water production method and apparatus, and a cleaning method and apparatus using water from which hydrogen peroxide has been removed.
This application claims priority based on Japanese Patent Application No. 2007-333451 for which it applied to Japan Patent Office on December 26, 2007, and uses the content here.

  Conventionally, so-called ultrapure water (secondary pure water) used for cleaning silicon wafers in the semiconductor industry, as shown in FIG. 5, is a pretreatment system 10, a primary pure water system 20, a secondary pure water system (sub-water). It is manufactured by processing raw water (industrial water, city water, well water, etc.) by an ultrapure water manufacturing apparatus 210 constituted by a system 40.

  The role of each system in FIG. 5 is as follows. The pretreatment system 10 includes, for example, a raw water tank 12, a coagulation sedimentation device 14, a filtration device 16, and a filtration water tank 18. The pretreatment system removes suspended substances and colloidal substances contained in the raw water of the raw water tank 12. The primary pure water system 20 includes, for example, an ion exchange device 22, an ultraviolet irradiation device 24, a microfiltration membrane device 26, a reverse osmosis (RO) membrane device 28, and a deaeration device 30. The primary pure water system 20 removes ions and organic components from the raw water from which suspended substances and the like have been removed by the pretreatment system 10 to obtain primary pure water.

  The subsystem 40 is a system for producing ultrapure water. The subsystem 40 includes, for example, a primary pure water tank 42, a heat exchanger 44, an ultraviolet oxidation device 46, a non-regenerative ion exchange device 48, and a final filter (UF membrane) device 50. The non-regenerative ion exchange device 48 is filled with an ion exchanger including an anion exchanger. The subsystem 40 is a process for producing ultrapure water by further increasing the purity of the primary pure water obtained by the primary pure water system 20. The primary pure water obtained by the primary pure water system 20 is stored in the primary pure water tank 42. The primary pure water in the primary pure water tank 42 is adjusted to a predetermined temperature by the heat exchanger 44. Next, the ultraviolet oxidizer 46 irradiates ultraviolet rays to decompose the TOC (total organic carbon) component in the pure water into organic acids and further to carbon dioxide. The organic acid and carbon dioxide are removed by the anion exchanger of the non-regenerative ion exchanger 48. Further, in the UF membrane device 50, the fine particles are removed, and ultrapure water is produced. The purity of the ultrapure water is maintained while circulating in the subsystem 40. On the other hand, a part of the ultrapure water is supplied to each use point 250, 252, 254. In each use point, ultrapure water is used as it is for cleaning wafers or the like, or ozone is further dissolved in ultrapure water and used for cleaning.

  As described above, when producing ultrapure water, the TOC component in pure water is decomposed by an ultraviolet oxidizer, and it is known that hydrogen peroxide of about 10 to 30 ppb is generated by this ultraviolet irradiation. Yes. Conventionally, as a method and apparatus for removing hydrogen peroxide in pure water, a combination of an oxidizing substance decomposing apparatus and a membrane deaerator (for example, Patent Document 1), a non-regenerative ion exchange apparatus To a membrane deaerator (for example, Patent Document 2), a method for contacting with a metal ion type cation exchange resin (for example, Patent Document 3), a device for contacting with a catalyst resin supporting palladium (for example, Patent Document 3) For example, Patent Document 4), a method of contacting with a reducing resin (for example, Patent Document 5), a catalyst-type oxidizing substance decomposition apparatus (for example, Patent Document 6), an anion exchange resin carrying sulfite ions A method of bringing it into contact (for example, Patent Document 7) has been reported. As described above, in order to remove hydrogen peroxide in pure water, a method of removing it with an ion exchange device, particularly an anion exchanger, is used.

  In addition, hydrogen peroxide in pure water increases the self-decomposition rate of ozone. For such a problem, an ozone water production method using ultrapure water with reduced hydrogen peroxide concentration is disclosed (for example, Patent Document 8).

However, when water containing hydrogen peroxide is passed through the ion exchange device for a certain period, there is a problem that the hydrogen peroxide removing ability is lowered and hydrogen peroxide leaks in a large amount into the treated water.
Japanese Patent Laid-Open No. 11-77091 Japanese Patent Laid-Open No. 10-57956 Japanese Patent Laid-Open No. 11-277059 JP 9-192658 A Japanese Patent Laid-Open No. 7-16580 Japanese Patent Laid-Open No. 2002-210494 JP 2001-179252 A Japanese Patent No. 3734207

  An object of the present invention is to effectively remove hydrogen peroxide from water containing hydrogen peroxide over a long period of time by an ion exchange device.

  When the inventor has stopped water flow for a certain period of time with respect to an ion exchange apparatus having reduced hydrogen peroxide removal ability, the hydrogen peroxide removal ability is restored again and hydrogen peroxide in water can be removed. And found the present invention.

That method of manufacturing pure water according to the present invention, there a water containing hydrogen peroxide, in the manufacturing method of the pure water with intermittent manner step of Rohm ion exchange apparatus OH type anion exchanger is filled In this stage, water is passed within a period in which the ability to remove hydrogen peroxide below a desired concentration is maintained, and then the water passage is stopped for a period in which the hydrogen peroxide removing ability of the ion exchange device is restored. Features. In the method, a plurality of the ion exchange devices may be arranged in parallel, and the water containing the hydrogen peroxide may be alternately passed through the plurality of ion exchange devices. The ion exchanger may be a single bed form of an OH type anion exchanger. The OH type anion exchanger may be a strongly basic anion exchanger.

The ozone water production method of the present invention is characterized in that ozone is dissolved in water that has passed through the ion exchange device by the pure water production method.

Apparatus for producing pure water according to the present invention, pure water having an ion exchange apparatus OH type anion exchanger is filled, and means for intermittent manner passed through a water containing hydrogen peroxide to the ion exchange unit In this manufacturing apparatus, the means passes water during a period in which the ability to remove hydrogen peroxide below a desired concentration is maintained, and then passes through the period during which the hydrogen peroxide removal ability of the ion exchange device is restored. It is characterized by stopping . In this apparatus, a plurality of the ion exchange devices may be arranged in parallel, and may have means for alternately passing water containing hydrogen peroxide through the plurality of ion exchange devices. The ion exchange device may be a single bed form of an OH type anion exchanger. The OH type anion exchanger may be a strongly basic anion exchanger.

The ozone water production apparatus of the present invention comprises the pure water production apparatus and means for dissolving ozone in the water that has passed through the ion exchange device .

The cleaning method of the present invention is characterized in that an electronic component or an electronic component manufacturing instrument is cleaned with water that has passed through the ion exchange device according to the pure water manufacturing method. The cleaning apparatus of the present invention includes the pure water manufacturing apparatus and an apparatus for cleaning an electronic component or an electronic component manufacturing instrument with water that has passed through the ion exchange device .

According to the method for producing pure water according to the present invention, hydrogen peroxide can be effectively removed from water containing hydrogen peroxide over a long period of time by an ion exchange device.

It is a flowchart of the ultrapure water manufacturing apparatus concerning the 1st Embodiment of this invention. It is a flowchart of the ultrapure water manufacturing apparatus concerning the 2nd Embodiment of this invention. It is a flowchart of the ultrapure water manufacturing apparatus concerning the 3rd Embodiment of this invention. It is a flowchart of the ultrapure water manufacturing apparatus concerning the 4th Embodiment of this invention. It is a flowchart of the conventional common ultrapure water manufacturing apparatus.

Explanation of symbols

52, 52a, 52b Ion exchange device 53, 55 Hydrogen peroxide removal device 54 Ozone water dissolution device 70, 72 Control device 110, 120 Ozone water production device

(First embodiment)
A first embodiment of the hydrogen peroxide removal apparatus of the present invention will be described with reference to FIG. FIG. 1 is a flowchart of the ultrapure water production apparatus 8 according to the embodiment of the present invention. In the present invention, “pure water” includes “ultra pure water”.

  The ultrapure water production apparatus 8 is different from the conventional ultrapure water production apparatus 210 shown in FIG. 5 in that a hydrogen peroxide removal apparatus 53 including one ion exchange device 52, an opening / closing valve 51, and a control device 70 is provided. It is added and includes a pretreatment system 10, a primary pure water system 20, a subsystem 40, and a hydrogen peroxide removal device 53. Between the subsystem 40 and the use point 60, an opening / closing valve 51 and an ion exchange device 52 are arranged in this order. The subsystem 40 is connected to each use point 62, 64.

  In the pretreatment system 10, a raw water tank 12, a coagulation sedimentation apparatus 14, a filtration apparatus 16, and a filtration water tank 18 are sequentially installed. The pretreatment system 10 removes suspended substances and colloidal substances contained in the raw water of the raw water tank 12. The raw water tank 12, the coagulation sedimentation apparatus 14, the coagulation sedimentation apparatus 14, the filtration apparatus 16, and the filtration water tank 18 are not particularly limited, and existing apparatuses can be used.

  In the primary pure water system 20, an ion exchange device 22, an ultraviolet irradiation device 24, a microfiltration membrane device 26, an RO membrane device 28, and a deaeration device 30 are sequentially installed. The ion exchanger 22 is filled with an ion exchanger. There are no particular limitations on the packing form of the ion exchanger, and any form such as a single bed form of an anion exchanger or a cation exchanger, or a mixed bed form or a multiple bed form of an anion exchanger and a cation exchanger, can be used. Also good.

  The ultraviolet irradiation device 24 is not particularly limited, and an existing device can be used. For example, there is an ultraviolet oxidizer that can irradiate ultraviolet rays having a wavelength around 185 nm in addition to ultraviolet rays having a wavelength around 254 nm. An ultraviolet oxidizer that can strongly irradiate ultraviolet rays having a wavelength of around 185 nm is preferable in terms of decomposition of the TOC component contained in the filtered water obtained by the pretreatment system 10.

  The microfiltration membrane device 26 is not particularly limited, and an existing device can be used. The RO membrane device 28 is not particularly limited, and an existing device can be used. The deaeration device 30 is not particularly limited, and an existing device can be used. For example, a vacuum deaerator, a membrane deaerator, etc. can be mentioned.

  The subsystem 40 is a system for producing ultrapure water by further increasing the purity of the primary pure water obtained by the primary pure water system 20. The subsystem 40 is sequentially installed so that the primary pure water tank 42, the heat exchanger 44, the ultraviolet oxidation device 46, the non-regenerative ion exchange device 48, and the final filter (UF membrane) device 50 can circulate ultrapure water. ing.

  The ultraviolet oxidation device 46 is not particularly limited as long as it has an ability to effectively decompose the TOC component in the primary pure water, and an existing device can be used.

  As the non-regenerative ion exchange device 48, an existing device can be used. Further, the non-regenerative ion exchange device 48 is filled with an ion exchanger. There are no particular limitations on the packing form of the ion exchanger, and any form such as a single bed form of an anion exchanger or a cation exchanger, or a mixed bed form or a multiple bed form of an anion exchanger and a cation exchanger, can be used. It is preferable that it is determined according to the quality of primary pure water and the quality of the intended ultrapure water.

  The heat exchanger 44 is not particularly limited as long as the primary pure water can be set to an arbitrary temperature, and an existing apparatus can be used. The UF membrane device 50 is not particularly limited, and an existing device can be used.

  As long as the ion exchange device 52 is filled with the OH type anion exchanger, the filling form is not particularly limited. Single bed form of OH type anion exchanger may be used, mixed bed form with other anion exchangers may be used, mixed bed form with cation exchanger or multiple bed form may be used. . However, from the viewpoint of effectively removing hydrogen peroxide, the OH-type anion exchanger is preferably packed in a single bed form.

  The OH type anion exchanger may be a strong basic anion exchanger or a weak basic anion exchanger. However, it is preferable to select a strongly basic anion exchanger from the viewpoint of improving the ability to remove hydrogen peroxide.

  The type of the OH type anion exchanger is not particularly limited, and examples thereof include ion exchange resins, ion exchange fibers, and monolithic porous ion exchangers. Among these, it is preferable to use an ion exchange resin having high versatility. The shape of the ion exchange resin is not particularly limited, and may be a gel shape, a porous shape, or a macroporous shape.

  Further, the ion exchanger filled in the ion exchange device 52 may be a regenerative type or a non-regenerative type. However, since the ion exchanger may be contaminated when it is regenerated, In the present embodiment, which is installed immediately before the point 60, the non-regenerative type is preferable. The ion exchange device 52 preferably includes a blow valve on the secondary side. Since water staying in the apparatus when water flow is stopped may be contaminated by the eluate from the inner wall of the ion exchanger or ion exchanger 52, the contaminated water immediately after the start of water flow is drained. It is.

  In the present embodiment, the hydrogen peroxide removal device 53 includes an ion exchange device 52, an opening / closing valve 51, and a control device 70.

  “Means for intermittently passing water containing hydrogen peroxide to an ion exchange device filled with an OH-type anion exchanger” means control for performing water flow to the ion exchange device 52 and stopping water flow. The device is not particularly limited as long as it has such a function. For example, the control device 70 that opens and closes the opening / closing valve 51 installed on the primary side of the ion exchange device 52 at regular intervals, or the activation of a pump for supplying ultrapure water from the subsystem 40 to the ion exchange device 52 And the control apparatus which performs a stop may be sufficient. The opening / closing of the opening / closing valve 51 and the starting and stopping of the pump may be performed automatically or manually.

  A method for producing ultrapure water and a method for removing hydrogen peroxide in ultrapure water in this embodiment will be described.

  In the pretreatment system 10, after the raw water is received in the raw water tank 12, the raw water is sequentially processed in the precipitation agglomeration tank 14 and the filtration device 16 to mainly remove colloids and suspended substances to obtain filtered water. The obtained filtered water is stored in the filtered water tank 18. In the primary pure water system 20, the filtered water in the filtered water tank 18 is adsorbed and removed by the ion exchanger 22, and the TOC that is ion-exchanged is removed by the ion exchanger.

  Next, the ultraviolet irradiation device 24 irradiates the filtered water with ultraviolet rays to sterilize the filtered water, or decomposes the TOC component in the filtered water to the state of organic acid and further to carbon dioxide. Subsequently, the microfiltration membrane device 26 and the RO membrane device 28 remove particle components and decomposition products such as organic acids generated by the ultraviolet irradiation device 24. Further, the permeated water is removed by the deaerator 30 to obtain dissolved primary oxygen.

  In the subsystem 40, the purity of the primary pure water obtained by the primary pure water system 20 is further increased to obtain ultrapure water. The primary pure water obtained by the primary system is stored in the primary pure water tank 42. The primary pure water is brought to a predetermined temperature by the heat exchanger 44 and then irradiated with ultraviolet rays by the ultraviolet oxidizer 46 to decompose the TOC component in the water into an organic acid and further to carbon dioxide. In addition, hydrogen peroxide is produced in the water during UV irradiation. Next, the non-regenerative ion exchange device 48 removes a trace amount of ion components and organic acids and carbon dioxide generated by ultraviolet irradiation.

  Fine particles are removed by the UF membrane device 50 to obtain ultrapure water. A part of the obtained ultrapure water is sent to the use points 62 and 64 as they are. Further, another part of the obtained ultrapure water is passed through the ion exchange device 52, and after contacted with the OH type anion exchanger to remove hydrogen peroxide, it is sent to the use point 60. Other part of the ultrapure water is returned to the primary pure water tank 42 and circulates in the subsystem 40. After passing water from the subsystem 40 to the ion exchange device 52 for a certain period, the control device 70 closes the open / close valve 51 and stops water flow. After a lapse of a predetermined period after the stoppage of water flow, the control device 70 opens the opening / closing valve 51, restarts the water flow, and restarts the removal of hydrogen peroxide in the ultrapure water. In this manner, water flow and stop to the ion exchange device 52 are repeatedly performed.

  The flow rate to the ion exchange device 52 of ultrapure water is not particularly limited, and can be determined according to the capability of the ion exchange device 52. For example, the space velocity (SV) for the anion exchanger is preferably set in the range of 1 to 500 L / L · R · h−1, and set in the range of 10 to 100 L / LR · h−1. More preferred. In addition, SV is represented by L / LR · h−1 which is a flow rate (L) circulated in one hour with respect to a unit volume (LR) of the ion exchanger.

  The water flow period to the ion exchange device 52 in the present embodiment is not particularly limited, and the amount of hydrogen peroxide in the ultrapure water and the treatment amount are taken into consideration, and the hydrogen peroxide in the ultrapure water is less than the desired concentration. It is preferable to set arbitrarily within the period in which the ability to remove the light is maintained. In addition, the water passage period may be set at a fixed time, or the amount of hydrogen peroxide leak measured on the secondary side of the ion exchange device 52, and the time when the concentration reaches a certain concentration is set as the end point of the water flow period. You may do it.

  The period during which the water flow to the ion exchange device 52 is stopped is not particularly limited, and the ion exchange device is considered in consideration of the amount of ultrapure water treated, the concentration of hydrogen peroxide in ultrapure water, the size of the ion exchange device 52, and the like. A period during which the hydrogen peroxide removal capacity of 52 is restored can be set. For example, to treat ultrapure water containing 15 to 30 ppb hydrogen peroxide and maintain the hydrogen peroxide concentration at a concentration of 10 ppb or less, the period for stopping the water flow in the range of 1 to 24 hours is set. It is preferable to set. Immediately after the start of water flow, it is preferable to supply ultrapure water from which hydrogen peroxide has been removed to the use point 60 after draining the contaminated water remaining in the ion exchange device 52. This is to prevent contamination of the use point.

  Although the ultrapure water before removing the hydrogen peroxide in the present embodiment is not particularly limited, the resistivity is preferably 15 MΩ · cm or more and TOC 10 ppb or less. Moreover, although the water temperature of ultrapure water is not specifically limited, 5-40 degreeC is preferable, 15-30 degreeC is more preferable, and it is more preferable that it is 20-25 degreeC.

  According to this embodiment, the hydrogen peroxide removal capability of the ion exchange device 52 can be restored by stopping the flow of ultrapure water to the ion exchange device 52. For this reason, hydrogen peroxide in ultrapure water can be effectively removed over a long period of time by repeating the water flow to and the stop of the ion exchange device 52.

(Second Embodiment)
A second embodiment of the hydrogen peroxide removal apparatus of the present invention will be described with reference to FIG. FIG. 2 is a flowchart of the ultrapure water production apparatus 100 according to the second embodiment. In this embodiment, the hydrogen peroxide removing device 53 of the first embodiment shown in FIG. 1 is changed to a hydrogen peroxide removing device 55 in which ion exchange devices 52a and 52b are arranged in parallel. In the present embodiment, the hydrogen peroxide removing device 55 includes ion exchange devices 52a and 52b arranged in parallel, and an open / close valve 51a is connected to the primary side of the ion exchange device 52a, so that the primary ion exchange device 52b is primary. An open / close valve 51b is connected to the side. Further, a control device 72 is connected to the on-off valves 51a and 52b. The flow paths on the primary side of the open / close valves 51 a and 51 b are integrated into one flow path and connected to the subsystem 40. Further, the secondary-side flow paths of the ion exchange devices 52a and 52b are connected to the use point 61 after being integrated into one flow path.

  The “means for alternately passing water containing hydrogen peroxide through a plurality of ion exchange devices” in the present embodiment is a control device that alternately performs water flow to the ion exchange devices 52a and 52b and stops water flow. There is no particular limitation as long as it has such a function. For example, water is supplied to each of the ion exchange devices 52a and 52b from the control device 72 that alternately opens and closes the opening / closing valves 51a and 51b installed on the primary side of the ion exchange devices 52a and 52b at regular intervals, respectively. It may be a control device for starting and stopping the pump. In addition, opening / closing of the opening / closing valves 51a and 51b and starting and stopping of the pump may be performed automatically or manually.

  A method for producing ultrapure water and a method for removing hydrogen peroxide in ultrapure water in the present embodiment will be described.

  The ultrapure water produced by the subsystem 40 is supplied to the use point 61 after passing through the ion exchange device 52a and removing hydrogen peroxide. After passing water through the ion exchange device 52a for a certain period of time, the control device 72 opens the open / close valve 51b and starts water flow through the ion exchange device 52b. At this time, the water treated by the ion exchange device 52 b is drained without being supplied to the use point 61. On the other hand, the supply of the water treated by the ion exchange device 52a to the use point 61 is continued. Further, after a certain period of time has elapsed, drainage of the ion exchange device 52b is stopped, and water treated by the ion exchange device 52b is supplied to the use point 61. Next, the control device 72 closes the open / close valve 51a to stop water flow to the ion exchange device 52a. Thus, the hydrogen peroxide removal in the ion exchange device 52a is switched to the hydrogen peroxide removal in the ion exchange device 52b.

  After passing water through the ion exchange device 52b for a certain period of time, the control device 72 opens the open / close valve 51a to start water passage to the ion exchange device 52a. At this time, the water treated by the ion exchange device 52 a is drained without being supplied to the use point 61. On the other hand, the supply of the water treated by the ion exchange device 52b to the use point 61 is continued. Furthermore, after the end of a certain period, drainage of the ion exchange device 52 a is stopped, and water treated by the ion exchange device 52 a is supplied to the use point 61. Next, the control device 72 closes the open / close valve 51b to stop water flow to the ion exchange device 52b. In this way, the switching of water flow to the ion exchange devices 52a and 52b is alternately repeated to remove the hydrogen peroxide in the ultrapure water, and the ultrapure water from which the hydrogen peroxide has been removed is supplied to the use point 61. To do.

  As the ion exchange devices 52a and 52b, the same ones as the ion exchange device 52 of the first embodiment can be used. There are no particular limitations on the period of water flow to the ion exchange devices 52a and 52b, and the amount of hydrogen peroxide and the amount of treatment in ultrapure water, as well as the recovery period for removing hydrogen peroxide from the ion exchange devices 52a and 52b, are determined. In consideration, it is preferable to arbitrarily set the hydrogen peroxide in the ultrapure water within a period in which the ability to remove hydrogen peroxide to a desired concentration or less is maintained. Further, the water flow period may be stopped after a predetermined period of time, or the leakage amount of hydrogen peroxide is measured on the secondary side of the ion exchange devices 52a and 52b to reach a certain concentration. The water flow may be stopped at that time.

  The period for stopping the water flow to the ion exchangers 52a and 52b is not particularly limited, taking into consideration the amount of ultrapure water treated, the concentration of hydrogen peroxide in the ultrapure water, the scale of the ion exchangers 52a and 52b, and the like. In addition, a period for recovering the hydrogen peroxide removal ability can be set. For example, in order to treat ultrapure water containing 15 to 30 ppb hydrogen peroxide and maintain the hydrogen peroxide concentration at a concentration of 10 ppb or less, it is preferably set within a range of 1 to 24 hours. Moreover, the drainage period after resuming water flow at the time of switching between the ion exchangers 52a and 52b is not particularly limited, and a period sufficient to drain contaminated water staying in the ion exchanger 52a or 52b is set. It is preferable.

  According to the present embodiment, since the two ion exchange devices 52a and 52b can be alternately switched to pass water, hydrogen peroxide is continuously removed without stopping the supply of ultrapure water to the use point 61. be able to.

(Third embodiment)
A third embodiment of the hydrogen peroxide removal apparatus of the present invention will be described with reference to FIG.
FIG. 3 is a flowchart of the ozone water production apparatus 110 according to the third embodiment. In the present embodiment, an ozone dissolving device 54 is installed on the secondary side of the hydrogen peroxide removing device 53 of the first embodiment shown in FIG. 1, and an ozone generating device 56 is provided in the ozone dissolving device 54. It is connected.

  The ozone dissolving device 54 is not particularly limited, a membrane dissolving device for dissolving ozone gas in water through a gas permeable membrane, a device for dissolving ozone gas in water by bubbling, a device for dissolving ozone gas in water through an ejector, Examples include a device that supplies ozone gas upstream of the pump and dissolves it by stirring in the pump. The gas permeable membrane used for dissolving the membrane is preferably a fluororesin-based hydrophobic porous membrane that can withstand the strong oxidizing power of ozone. Moreover, the ozone generator 56 is not specifically limited, The ozone generator by silent discharge, an electrolysis method, etc. is mentioned.

A method for removing hydrogen peroxide in water and a method for producing ozone water in the present embodiment will be described.
The ultrapure water produced by the subsystem 40 is processed by the hydrogen peroxide removing device 53 to remove hydrogen peroxide. The ozone gas produced by the ozone generator 56 is sent to the ozone dissolver 54. The ozone gas is dissolved by the ozone dissolving device 54 in the water from which the hydrogen peroxide has been removed. Ozone water in which ozone of a predetermined concentration is dissolved in water is supplied to the use point 66.

  In the present embodiment, the dissolved ozone concentration is not particularly limited, and is preferably set according to the use at the use point 66. For example, it is preferably set within a range of 1 to 100 ppm depending on the use.

  According to this embodiment, since water from which hydrogen peroxide has been removed can be used, self-decomposition of ozone in the obtained ozone water can be suppressed. As a result, the ozone concentration in the ozone water is stabilized. Moreover, high concentration ozone water can be stably supplied to a use point.

(Fourth embodiment)
A fourth embodiment of the hydrogen peroxide removal apparatus of the present invention will be described with reference to FIG. FIG. 4 is a flowchart of the ozone water production apparatus 120 according to the fourth embodiment. In this embodiment, the hydrogen peroxide removing device 53 of the third embodiment shown in FIG. 3 is changed to a hydrogen peroxide removing device 55 in which ion exchange devices 52a and 52b are arranged in parallel.

A method for removing hydrogen peroxide in water and a method for producing ozone water in the present embodiment will be described.
The ultrapure water produced by the subsystem 40 is processed by the hydrogen peroxide removing device 55 to remove hydrogen peroxide. The ozone gas produced by the ozone generator 56 is sent to the ozone dissolver 54. In the water from which the hydrogen peroxide has been removed, ozone gas is dissolved by the ozone dissolving device 54, and ozone water in which ozone of a predetermined concentration is dissolved is supplied to the use point 67.

  According to this embodiment, since the two ion exchange devices 52a and 52b can be switched alternately to pass water, hydrogen peroxide in water can be removed continuously. As a result, ozone water with a stable ozone concentration can be continuously supplied to the use point. In addition, high-concentration ozone water can be supplied to the use point stably and continuously.

(Other embodiments)
The hydrogen peroxide removal method and the hydrogen peroxide removal apparatus of the present invention are not limited to the above-described embodiments.
In the first to fourth embodiments, branched water (ultra-pure water) from the outlet of the UF membrane device 50 of the subsystem 40 is used as water to be treated and is passed through each ion exchange device. However, the water to be treated is not limited to the branched water and may be water containing hydrogen peroxide. For example, it may be the outlet water of the ultraviolet oxidation device 46 and the non-regenerative ion exchange device 48, or may be water in which ultrapure water produced by the subsystem 40 is received in a tank. Furthermore, the water of the primary system 20 may be sufficient.

  In the first to fourth embodiments, the hydrogen peroxide removing device 53 or 55 is arranged while the branch water of the subsystem 40 is sent to each use point. However, the arrangement location is not limited to this. For example, the non-regenerative ion exchange device 48 may be provided with “means for intermittently passing water containing hydrogen peroxide” such as the hydrogen peroxide removing device 53 or 55. Further, a “means for alternately passing water containing hydrogen peroxide through a plurality of ion exchange devices” may be provided in a form such as the hydrogen peroxide removing device 55.

  In the second and fourth embodiments, two ion exchange devices 52a and 52b are arranged in parallel as the hydrogen peroxide removing device 55, but three or more ion exchange devices may be provided. It is preferable to determine the number of installed units in consideration of the amount of water treated and the capacity of the ion exchangers in the ion exchange devices 52a and 52b.

  The pretreatment system 10, the primary pure water system 20, and the subsystem 40 in the first to fourth embodiments are examples and are not limited to the above-described embodiments. Devices other than those described above can be used, or other combinations can be used.

  In the first to fourth embodiments, the opening / closing valve 51 is installed on the temporary side of the ion exchange device 52, and the opening / closing valves 51a, 51b are installed on the temporary side of the ion exchange devices 52a, 52b. The installation location of is not limited to this, and may be installed on the secondary side of the ion exchange devices 52, 52a, 52b.

  In the first and second embodiments, the water from which hydrogen peroxide has been removed is directly sent to the use point by the ion exchange device 52 or the ion exchange device 52a or 52b, but the ion exchange devices 52, 52a, Another device may be installed on the secondary side of 52b. In particular, it is preferable to install a filtration membrane device (microfilter device or UF membrane device) for removing fine particles. This is because there is a possibility that dust will be generated from the open / close valve or the like due to water supply / stop to each ion exchange device, and the generated fine particles can be removed. Similarly, in the third and fourth embodiments, another device, particularly a filtration membrane device for removing fine particles, may be installed on the secondary side of the ion exchange devices 52, 52a, 52b.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, it is not limited to an Example.
Example 1
An acrylic column was packed with 100 mL of an ion exchange resin, AmberJet 4002 (OH) (OH-type strongly basic anion exchange resin, gel type) manufactured by Rohm and Haas, and an ion exchange apparatus A. Got. Water having a hydrogen peroxide concentration of 15 to 30 ppb at 20 to 25 ° C. was passed through the obtained ion exchange apparatus A at SV = 50 L / LR · h−1. Two hours after the start of water flow, the opening / closing valve on the primary side of the ion exchange device A was closed to stop water flow and left for 5 hours. After leaving for 5 hours, water was passed again for 2 hours. In this way, treated water was obtained by continuously passing water for 10 days in a cycle of 2 hours water flow / 5 hours water flow stop. 29 hours after the start of water flow (total water flow time: 9 hours, water flow rate: BV (water flow rate with respect to the resin volume of the ion exchanger = volume times) = 450) and 10 days later (total water flow time: 68 hours, water flow rate) : BV = 3400), the hydrogen peroxide concentration was measured for the treated water. The measured values are shown in Table 1. The water in this example was obtained by passing primary pure water through a heat exchanger, a membrane deaerator, an ultraviolet oxidation device, a non-regenerative mixed bed ion exchanger, and a UF membrane device in this order. The obtained resistivity = 18 MΩ · cm or more and TOC = 1 ppb or less ultrapure water (hereinafter the same in Examples 2 to 4 and Comparative Examples 1 and 2).

(Example 2)
An acrylic column was packed with 100 mL of an ion exchange resin, Amberlite IRA900 (OH) (OH-type strongly basic anion exchange resin, macroporous type) manufactured by Rohm and Haas, and an ion exchange apparatus B. Got. Thereafter, water was continuously passed for 10 days in the same manner as in Example 1 to obtain treated water. The treated water obtained 29 hours after the start of water flow (total water flow time: 9 hours, water flow rate: BV = 450) and 10 days later (total water flow time: 68 hours, water flow rate: BV = 3400), The hydrogen peroxide concentration was measured, and the results are shown in Table 1.

(Comparative Example 1)
Water having a hydrogen peroxide concentration of 15 to 30 ppb at 20 to 25 ° C. was passed through the ion exchange apparatus A obtained in Example 1 at SV = 50 L / LR · h−1 to obtain treated water. It was. The hydrogen peroxide concentration in the treated water 30 minutes after the start of water flow (BV = 25) and 24 hours after (BV = 1200) was measured, and the results are shown in Table 1.

(Comparative Example 2)
To the ion exchange apparatus B obtained in Example 2, water having a hydrogen peroxide concentration of 15 to 30 ppb at 20 to 25 ° C. was passed at SV = 50 L / LR · h−1 to obtain treated water. It was. The hydrogen peroxide concentration in the treated water 30 minutes after the start of water flow (BV = 25) and 24 hours after (BV = 1200) was measured, and the results are shown in Table 1.

(Example 3)
In Comparative Example 1, after passing water for 24 hours, water flow to the ion exchange apparatus A was stopped for 3 days. After that, water supply with a hydrogen peroxide concentration of 15 to 30 ppb at 20 to 25 ° C. was resumed at SV = 50 L / LR · h−1. The hydrogen peroxide concentration in the treated water 30 minutes after restarting the water flow was measured, and the results are shown in Table 2.

Example 4
In Comparative Example 2, after passing water for 24 hours, passing water to the ion exchange device B was stopped for 3 days. Thereafter, the water flow of 20 to 25 ° C. and a hydrogen peroxide concentration of 15 to 30 ppb was resumed at SV = 50 L / LR · h−1. The hydrogen peroxide concentration in the treated water 30 minutes after restarting the water flow was measured, and the results are shown in Table 2.

(Example 5)
A G5 cylinder (manufactured by Organo Corporation) was charged with 5 L of ion exchange resin, Amber Jet 4002 (OH), manufactured by Rohm and Haas, and ion exchange apparatus C was obtained. Treated water was obtained by passing water having a hydrogen peroxide concentration of 15 to 20 ppb at a flow rate of 200 L / h (SV = 40 L / LR · h−1). Then, ozone gas was melt | dissolved in the obtained treated water by Japan Gore-Tex Co., Ltd. product and GM-02RES (ozone melt | dissolution membrane module), and ozone water was manufactured. The hydrogen peroxide concentration in the treated water and the ozone concentration in the ozone water at 3 hours and 4 days after the start of production of the ozone water were measured, and the results are shown in Table 3. The water in this example was obtained by processing primary pure water in the order of an ultraviolet oxidizer, a non-regenerative mixed bed ion exchanger, and a UF membrane device, and the resistivity = 18 MΩ · cm or higher. , TOC = 1 ppb or less ultrapure water (hereinafter the same in Comparative Example 3).

(Comparative Example 3)
Ozone water was produced under the same conditions as in Example 5 except that water having a hydrogen peroxide concentration of 15 to 20 ppb was not passed through the ion exchange device C. The hydrogen peroxide concentration in the treated water and the ozone concentration in the ozone water were measured 4 days after the start of production of the ozone water, and the results are shown in Table 3.

(Hydrogen peroxide concentration)
As a method for quantifying low-concentration hydrogen peroxide in ultrapure water, a known phenol phthaline method, for example, the method described in JP-B-56-54582 was used.

(Measurement of ozone concentration)
The ozone concentration was measured by an ultraviolet absorptiometry using a portable dissolved ozone concentration meter (OM-101P-30, manufactured by Aplix Corporation).

  From the results of Table 1, in Examples 1 and 2, the concentration of hydrogen peroxide in the treated water was almost the same at 29 hours after the start of water flow (BV = 450) and 10 days after the start of water flow (BV = 3400). It was kept low. On the other hand, in Comparative Examples 1 and 2, the hydrogen peroxide concentration exceeded 10 ppb after 24 hours of water flow (BV = 1200). From this, it was found that hydrogen peroxide can be removed without reducing the hydrogen peroxide removal ability of the OH-type anion exchange resin by intermittently passing water through the ion exchange device. . As is clear from the results in Table 2, even in the ion exchange apparatus used for removing hydrogen peroxide in Comparative Examples 1 and 2, hydrogen peroxide removal from the OH-type anion exchange resin was stopped by stopping the water flow. It was confirmed that the ability could be restored.

  As shown in Table 3, in Example 5, ozone water was produced using treated water from which hydrogen peroxide had been removed by passing water through an ion exchange device, so that treatment was performed even 4 days after the start of ozone water production. The water maintained a hydrogen peroxide concentration of 10 ppb or less, and the ozone concentration of ozone water also exceeded 40 ppm.

  On the other hand, in Comparative Example 3, since the water to be treated was not passed through the ion exchange device, the hydrogen peroxide concentration in the water was at a high level. Further, the ozone water produced with such water had a lower ozone concentration than that of Example 5. From this, and from the results of Examples 1 to 4, by repeating the water flow and stopping to the ion exchange device and removing hydrogen peroxide in water, ozone water having a stable concentration can be obtained over a long period of time. Furthermore, it was suggested that highly concentrated ozone water could be obtained.

  According to the method for removing hydrogen peroxide of the present invention, water containing hydrogen peroxide is intermittently passed through the ion exchange device. In addition, when a plurality of ion exchange devices are arranged, hydrogen peroxide is contained. Since water is alternately passed, hydrogen peroxide can be effectively removed from water containing hydrogen peroxide over a long period of time.

Claims (18)

Water containing hydrogen peroxide, a method of producing pure water having a step of intermittent manner passed through the ion exchange apparatus OH type anion exchanger is filled, in said step, over the following desired concentration A method for producing pure water, wherein water is passed within a period during which the ability to remove hydrogen oxide is maintained, and thereafter, water passing is stopped for a period during which the hydrogen peroxide removing ability of the ion exchange device is restored . The method for producing pure water according to claim 1, wherein the water containing hydrogen peroxide is passed through the ion exchange device for a certain period of time. The method for producing pure water according to claim 1, wherein the concentration of hydrogen peroxide contained in water is measured on the secondary side of the ion exchange device, and the water flow period is set based on the measured concentration of hydrogen peroxide. The method for producing pure water according to claim 1, wherein a plurality of the ion exchange devices are arranged in parallel, and the water containing the hydrogen peroxide is alternately passed through the plurality of ion exchange devices. The ozone water manufacturing method which melt | dissolves ozone further in the water which passed the said ion exchanger by the manufacturing method of any one of Claim 1 to 4. An ion exchange device OH type anion exchanger is filled, an apparatus for producing a pure water and a means for intermittent manner passed through the water containing hydrogen peroxide to the ion exchange unit, said means, Purified water is passed during a period in which the ability to remove hydrogen peroxide below a desired concentration is maintained, and then stopped for a period in which the hydrogen peroxide removing ability of the ion exchange device is restored . manufacturing device. The pure water production apparatus according to claim 6, wherein the means causes water containing the hydrogen peroxide to flow through the ion exchange device for a certain period of time. The pure water according to claim 6, wherein the means measures the concentration of hydrogen peroxide contained in water on the secondary side of the ion exchange device, and sets the water passage period based on the measured concentration of hydrogen peroxide. Manufacturing equipment. The apparatus for producing pure water according to claim 6, comprising a plurality of ion exchange devices arranged in parallel, and means for alternately passing water containing hydrogen peroxide through the plurality of ion exchange devices. The pure water production apparatus according to claim 6 , wherein the means is a control device that opens and closes an open / close valve installed on a primary side of the ion exchange device at regular intervals . The apparatus for producing pure water according to claim 6 , wherein the means is a control device for starting and stopping a pump for supplying water containing hydrogen peroxide to the ion exchange device. The pure water production apparatus according to claim 9, wherein the means is a control device that alternately opens and closes the opening and closing valves respectively installed on the primary sides of the plurality of ion exchange devices at regular intervals . The pure water production apparatus according to claim 9, wherein the means is a control device that starts and stops a pump that supplies water containing hydrogen peroxide to the plurality of ion exchange devices. An ozone water production apparatus comprising: the pure water production apparatus according to any one of claims 6 to 13; and means for dissolving ozone in water that has passed through the ion exchange apparatus. With water which has passed through the ion exchange unit by the method according to claim 1, any one of 4, cleaning method characterized by cleaning the electronic component or electronic component manufacturing device. To the production apparatus of the pure water according to any one of claims 6 13, with water that has passed through the ion exchanger, characterized in that it comprises a device and for cleaning electronic components or electronic parts manufacturing instruments Cleaning device. Ozone is dissolved in the water that has passed through the ion exchange device by the manufacturing method according to any one of claims 1 to 4 to produce ozone water, and an electronic component or an electronic component manufacturing instrument is prepared using the ozone water. A cleaning method characterized by cleaning. The apparatus for producing pure water according to any one of claims 6 to 13, an apparatus for producing ozone water by dissolving ozone in the water that has passed through the ion exchange apparatus, and electronic components or An apparatus for cleaning an electronic component manufacturing apparatus.

Images