JP2023112836A - Pure water manufacturing equipment and method of operating pure water manufacturing equipment - Google Patents

Pure water manufacturing equipment and method of operating pure water manufacturing equipment Download PDF

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JP2023112836A
JP2023112836A JP2022014798A JP2022014798A JP2023112836A JP 2023112836 A JP2023112836 A JP 2023112836A JP 2022014798 A JP2022014798 A JP 2022014798A JP 2022014798 A JP2022014798 A JP 2022014798A JP 2023112836 A JP2023112836 A JP 2023112836A
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water
chamber
osmosis membrane
reverse osmosis
treated
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JP7347556B2 (en
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麗奈 田部井
Rena Tabei
晃久 加藤
Akihisa Kato
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Kurita Water Industries Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
    • B01D61/44—Ion-selective electrodialysis
    • B01D61/46—Apparatus therefor
    • B01D61/48—Apparatus therefor having one or more compartments filled with ion-exchange material, e.g. electrodeionisation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
    • B01D61/44—Ion-selective electrodialysis
    • B01D61/54—Controlling or regulating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/58—Multistep processes
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/30—Treatment of water, waste water, or sewage by irradiation
    • C02F1/32—Treatment of water, waste water, or sewage by irradiation with ultraviolet light
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/469—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00—Multistage treatment of water, waste water or sewage
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
    • Y02A20/124—Water desalination
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
    • Y02A20/124—Water desalination
    • Y02A20/131—Reverse-osmosis

Abstract

To provide a pure water manufacturing equipment and its operation method capable of producing pure water with stable water quality even if the treated water quality of the reverse osmosis membrane device fluctuates in a pure water manufacturing device that has a reverse osmosis membrane device and an electro-deionization device and supplies treated water at high pH to the reverse osmosis membrane device.SOLUTION: A primary pure water production system has a reverse osmosis membrane device, an ultraviolet oxidation device, an electro-deionization device 8, and a feed water pump that supplies feed water to the electro-deionization device 8. In this primary pure water manufacturing device, the treated water W4 treated by the ultraviolet oxidation device is passed through a demineralization chamber 25 of the electro-deionizer 8 to produce demineralized water W5. At this time, the demineralized water W5 is separated as the supply water (electrode water) for a concentration chamber 26 and electrode chambers (anode chamber 27 and cathode chamber 28) of the electrode deionizer 8, and supplied in the reverse direction of the water flow direction in the demineralization chamber 25. When the conductivity of the treated water in the reverse osmosis membrane device 5 becomes 0.3 mS/m or higher, the flow rate of the treated water W4 to the desalination chamber 25 is controlled to decrease to less than 50 to 100%.SELECTED DRAWING: Figure 2

Description

本発明は、純水製造装置の運転方法に関し、特に半導体、液晶等の電子産業分野で利用される超純水を製造する超純水製造システムを構成する純水製造装置及びその運転方法に関する。 TECHNICAL FIELD The present invention relates to a method of operating a pure water production apparatus, and more particularly to a pure water production apparatus constituting an ultrapure water production system for producing ultrapure water used in the electronics industry such as semiconductors and liquid crystals, and a method of operating the same.

従来、半導体等の電子産業分野で用いられている超純水は、前処理システム、一次純水製造装置及び一次純水を処理するサブシステム（二次純水製造装置）で構成される超純水製造システムで原水を処理することにより製造されている。 Conventionally, the ultrapure water used in the electronic industry field such as semiconductors is an ultrapure It is produced by treating raw water in a water production system.

例えば、図１に示すように超純水製造システム１は、前処理装置２と一次純水製造装置（純水製造装置）３とサブシステム４といった３段の装置で構成されている。このような超純水製造システム１の前処理装置２では、原水Ｗの濾過、凝集沈殿、精密濾過膜などによる前処理が施され、主に懸濁物質が除去される。 For example, as shown in FIG. 1, an ultrapure water production system 1 is composed of three stages of devices: a pretreatment device 2 , a primary pure water production device (pure water production device) 3 , and a subsystem 4 . In the pretreatment device 2 of such an ultrapure water production system 1, the raw water W is subjected to pretreatment such as filtration, coagulation sedimentation, and microfiltration membranes, mainly removing suspended solids.

一次純水製造装置３は、前処理水Ｗ１を処理する逆浸透膜装置５と、紫外線酸化装置６と、電気脱イオン装置８と、この電気脱イオン装置８に給水を供給する給水ポンプ７とを有する。この一次純水製造装置３で前処理水Ｗ１中の大半の電解質、微粒子、生菌等の除去を行うとともに有機物を分解して、一次純水（純水）Ｗ２を得る。 The primary pure water production device 3 includes a reverse osmosis membrane device 5 for treating the pretreated water W1, an ultraviolet oxidation device 6, an electrodeionization device 8, and a water supply pump 7 for supplying water to the electrodeionization device 8. have The primary pure water production apparatus 3 removes most of the electrolytes, fine particles, viable bacteria, etc. from the pretreated water W1 and decomposes organic matter to obtain primary pure water (pure water) W2.

そして、サブシステム４は、サブタンク１０と供給ポンプ１１と紫外線酸化装置６と非再生型混床式イオン交換装置１３と限外ろ過膜（ＵＦ膜）１４とを有し、限外ろ過膜（ＵＦ膜）１４からユースポイント１５を経由してサブタンク１０に還流する構成となっている。このサブシステム４では、一次純水製造装置３で製造された一次純水Ｗ２中に含まれる微量の有機物（ＴＯＣ成分）を酸化分解し、炭酸イオン、有機酸類、アニオン性物質、さらには金属イオンやカチオン性物質を除去し、最後に限外濾過（ＵＦ）膜１４で微粒子を除去して超純水Ｗ３とし、これをユースポイント１５に供給して、未使用の超純水Ｗ３はサブシステム４の前段に還流する。 The sub-system 4 includes a sub-tank 10, a supply pump 11, an ultraviolet oxidation device 6, a non-regenerative mixed-bed ion exchange device 13, and an ultrafiltration membrane (UF membrane) 14. Membrane) 14 is configured to flow back to sub-tank 10 via use point 15 . This subsystem 4 oxidatively decomposes trace amounts of organic substances (TOC components) contained in the primary pure water W2 produced by the primary pure water producing apparatus 3 to produce carbonate ions, organic acids, anionic substances, and metal ions. and cationic substances are removed, and finally fine particles are removed by an ultrafiltration (UF) membrane 14 to obtain ultrapure water W3, which is supplied to a point of use 15, and unused ultrapure water W3 is sent to a subsystem Reflux to the previous stage of 4.

上述したような超純水製造システム１の一次純水製造装置３では、逆浸透膜装置５の処理性能向上を目的に、逆浸透膜装置の給水にＮａＯＨ等のアルカリを注入してｐＨ８．５以上とし、各種成分のイオン化を促進して処理することが行われている。 In the primary pure water production device 3 of the ultrapure water production system 1 as described above, for the purpose of improving the treatment performance of the reverse osmosis membrane device 5, alkali such as NaOH is injected into the water supply of the reverse osmosis membrane device to achieve a pH of 8.5. As described above, treatment is performed by promoting ionization of various components.

しかしながら、逆浸透膜装置５の給水にアルカリを注入すると、後段の電気脱イオン装置８への給水の水質（電気伝導率など）が増加し、電気脱イオン装置８への負荷が大きくなる、という問題点がある。特に原水水質の変動や逆浸透膜装置５の回収率の変更などにより、逆浸透膜装置５の処理水水質がさらに低下した場合においては、電気脱イオン装置８での処理水（脱塩水）の水質も低下し、これに起因して所望とする水質の純水Ｗ２が得られなくなるおそれがある、という問題点がある。 However, when alkali is injected into the water supply of the reverse osmosis membrane device 5, the water quality (electrical conductivity, etc.) of the water supply to the subsequent electrodeionization device 8 increases, and the load on the electrodeionization device 8 increases. There is a problem. In particular, when the quality of the treated water from the reverse osmosis membrane device 5 further deteriorates due to fluctuations in the quality of the raw water or a change in the recovery rate of the reverse osmosis membrane device 5, the water (demineralized water) treated by the electrodeionization device 8 There is a problem that the water quality is also lowered, and this may make it impossible to obtain the pure water W2 having the desired quality.

本発明は上記課題に鑑みてなされたものであり、逆浸透膜装置と電気脱イオン装置とを有し、逆浸透膜装置に高ｐＨで被処理水を供給する純水製造装置における逆浸透膜装置の処理水質が変動しても安定した水質で純水を製造することが可能な純水製造装置及びその運転方法を提供することを目的とする。 The present invention has been made in view of the above problems. It is an object of the present invention to provide a pure water production apparatus capable of producing pure water with stable water quality even when the quality of water treated by the apparatus fluctuates, and to provide a method of operating the same.

上記目的に鑑み、本発明は第一に、逆浸透膜装置と電気脱イオン装置とをこの順に備え、前記電気脱イオン装置の脱塩室にこの逆浸透膜装置の処理水を通水するとともに該脱塩室を通過した処理水の一部を前記脱塩室と逆方向に濃縮室に通水する純水製造装置であって、前記逆浸透膜装置の処理水の導電率又は比抵抗値を測定する計測手段と、前記計測手段の測定値に基づいて前記電気脱イオン装置の脱塩室に供給する水量を制御する制御手段とを有し、前記制御手段は、前記計測手段の測定値に基づく逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ未満の場合の前記脱塩室への流量を１００％とした場合に、該逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ以上となったら該脱塩室流量を５０～１００％未満に減少させるように制御する、純水製造装置を提供する（発明１）。 In view of the above object, the present invention firstly comprises a reverse osmosis membrane device and an electrodeionization device in this order, and supplies treated water from the reverse osmosis membrane device to the desalination chamber of the electrodeionization device. A water purifying apparatus in which part of the treated water that has passed through the deionization chambers is passed through a concentration chamber in a direction opposite to the deionization chambers, wherein the conductivity or specific resistance value of the treated water of the reverse osmosis membrane device and a control means for controlling the amount of water supplied to the deionization chamber of the electrodeionization apparatus based on the measurement value of the measurement means, wherein the control means measures the measurement value of the measurement means The conductivity of the treated water of the reverse osmosis membrane device is 0 when the flow rate to the deionization chamber is 100% when the conductivity of the treated water of the reverse osmosis device is less than 0.3 mS / m based on Provided is a pure water production apparatus which is controlled to reduce the flow rate of the demineralization chamber to less than 50 to less than 100% when it reaches 3 mS/m or more (Invention 1).

かかる発明（発明１）によれば、電気脱イオン装置の処理水の水質の低下を抑制することができる。これは以下のような理由によると考えられる。すなわち、逆浸透膜装置の処理水の水質が低下した場合には、電気脱イオン装置に負荷がかかり、電気脱イオン装置の処理水（脱塩水）の水質の低下を招きやすいので、逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ以上となったら、電気脱イオン装置の負荷を低減するために脱塩室流量を減少させるように制御することが考えられるが、そうすると脱塩室のイオン交換樹脂に吸着していたイオンは濃縮室に移動し、濃縮室のイオン濃度が増加することにより、濃縮室から脱塩室へのイオンの逆拡散が増加し、処理水の水質が低下する。そこで、電気脱イオン装置の脱塩室を通過した処理水の一部を前記脱塩室と逆方向に濃縮室に通水することにより、濃縮室下部のイオン濃度を低く維持できるので、電気脱イオン装置の処理水の水質の低下を抑制することができる。 According to this invention (Invention 1), it is possible to suppress deterioration of the water quality of the treated water of the electrodeionization apparatus. It is considered that this is due to the following reasons. That is, when the water quality of the treated water of the reverse osmosis membrane device deteriorates, the electrodeionization device is overloaded, and the water quality of the treated water (demineralized water) of the electrodeionization device tends to deteriorate. When the conductivity of the treated water in the device reaches 0.3 mS/m or more, it is conceivable to control the deionization chamber flow rate to decrease in order to reduce the load on the electrodeionization device. The ions adsorbed on the ion-exchange resin move to the concentrating compartment, and the ion concentration in the concentrating compartment increases, which increases the back diffusion of ions from the concentrating compartment to the demineralization compartment, resulting in a decrease in the quality of the treated water. do. Therefore, by passing a portion of the treated water that has passed through the desalting chambers of the electrodeionization apparatus through the concentrating chambers in the opposite direction to the desalting chambers, the ion concentration in the lower portions of the concentrating chambers can be maintained low, thereby improving the electrodeionization. It is possible to suppress the deterioration of the water quality of the treated water of the ion device.

上記発明（発明１）においては、前記逆浸透膜装置と前記電気脱イオン装置との間に紫外線酸化装置を有することが好ましい（発明２）。 In the above invention (invention 1), it is preferable to have an ultraviolet oxidation device between the reverse osmosis membrane device and the electrodeionization device (invention 2).

かかる発明（発明２）によれば、紫外線酸化装置で逆浸透膜処理水に残存するＴＯＣを分解することで、得られる純水の水質をさらに向上させることができる。 According to this invention (invention 2), by decomposing the TOC remaining in the reverse osmosis membrane-treated water with the ultraviolet oxidation device, the quality of the pure water obtained can be further improved.

上記発明（発明１，２）においては、前記電気脱イオン装置が、脱塩室の処理水の一部を該電気脱イオン装置の電極室に通水することが好ましい（発明３）。 In the above inventions (Inventions 1 and 2), it is preferable that the electrodeionization apparatus causes part of the treated water in the deionization chamber to flow through the electrode chambers of the electrodeionization apparatus (Invention 3).

かかる発明（発明３）によれば、逆浸透膜装置、あるいは紫外線酸化装置で処理された処理水を電気脱イオン装置の電極室に流通すると、電気脱イオン装置の電極及び電極室内のイオン交換体の劣化やスケール生成が促進される。そこで、電気脱イオン装置の脱塩室の処理水の一部を電気脱イオン装置の電極室に通水することで、電気脱イオン装置の電極及び電極室内のイオン交換体の劣化やスケール生成を抑制することができ、電気脱イオン装置を長期間安定して運転することができる。 According to this invention (invention 3), when the treated water treated by the reverse osmosis membrane device or the ultraviolet oxidation device flows through the electrode chamber of the electrodeionization device, the electrode of the electrodeionization device and the ion exchanger in the electrode chamber deterioration and scale formation are accelerated. Therefore, by passing part of the treated water in the desalting chamber of the electrodeionization apparatus through the electrode chamber of the electrodeionization apparatus, the deterioration and scale formation of the electrodes and the ion exchanger in the electrode chamber of the electrodeionization apparatus can be prevented. can be suppressed, and the electrodeionization apparatus can be stably operated for a long period of time.

また、本発明は第二に、逆浸透膜装置と電気脱イオン装置とをこの順に備え、前記逆浸透膜装置にｐＨ８．５以上の給水を供給し、前記電気脱イオン装置の脱塩室にこの逆浸透膜装置の処理水を通水するとともに該脱塩室を通過した処理水の一部を前記脱塩室と逆方向に濃縮室に通水する純水製造装置の運転方法において、前記逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ未満の場合の前記脱塩室への流量を１００％とした場合に、前記逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ以上となったら該脱塩室流量を５０～１００％未満に減少させるように制御する、純水製造装置の運転方法を提供する（発明４）。 Secondly, according to the present invention, a reverse osmosis membrane device and an electrodeionization device are provided in this order, water having a pH of 8.5 or higher is supplied to the reverse osmosis membrane device, In the method for operating a water purifying apparatus in which the treated water of the reverse osmosis membrane device is passed and part of the treated water that has passed through the desalting chambers is passed through the concentrating chambers in a direction opposite to the desalting chambers, The conductivity of the treated water of the reverse osmosis membrane device is 0.3 mS when the flow rate to the desalination chamber is 100% when the conductivity of the treated water of the reverse osmosis device is less than 0.3 mS / m. /m or more, there is provided a method of operating a water purifying apparatus for controlling the desalting chamber flow rate to be reduced to less than 50 to less than 100% (Invention 4).

かかる発明（発明４）によれば、逆浸透膜装置の処理水の水質が低下した場合には、電気脱イオン装置に負荷がかかり、電気脱イオン装置の処理水の水質の低下を招きやすいので、逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ以上となったら脱塩室流量を５０～１００％未満に減少させるように制御するとともに、電気脱イオン装置の脱塩室を通過した処理水の一部を前記脱塩室と逆方向に濃縮室に通水することにより、電気脱イオン装置の処理水の水質の低下を抑制することができる。 According to this invention (Invention 4), when the water quality of the treated water of the reverse osmosis membrane device deteriorates, the electrodeionization device is overloaded, and the water quality of the treated water of the electrodeionization device tends to deteriorate. , When the conductivity of the treated water of the reverse osmosis membrane device becomes 0.3 mS / m or more, the desalination chamber flow rate is controlled to decrease to less than 50 to 100%, and the water passes through the desalination chamber of the electrodeionization device. By passing part of the treated water through the concentrating chambers in the opposite direction to the deionization chambers, it is possible to suppress deterioration in water quality of the treated water of the electrodeionization apparatus.

上記発明（発明４）においては、前記純水製造装置が、前記逆浸透膜装置と前記電気脱イオン装置との間に紫外線酸化装置を有することが好ましい（発明５）。 In the above invention (invention 4), it is preferable that the water purification device has an ultraviolet oxidation device between the reverse osmosis membrane device and the electrodeionization device (invention 5).

かかる発明（発明５）によれば、紫外線酸化装置で逆浸透膜処理水に残存するＴＯＣを分解することで、得られる純水の水質をさらに向上させることができる。 According to this invention (invention 5), by decomposing the TOC remaining in the reverse osmosis membrane-treated water with the ultraviolet oxidation device, the quality of the pure water obtained can be further improved.

上記発明（発明４，５）においては、前記電気脱イオン装置の脱塩室の処理水の一部を該電気脱イオン装置の電極室に通水することが好ましい（発明６）。 In the above inventions (Inventions 4 and 5), it is preferable that part of the treated water in the deionization chamber of the electrodeionization apparatus is passed through the electrode chambers of the electrodeionization apparatus (Invention 6).

かかる発明（発明６）によれば、逆浸透膜装置、あるいは紫外線酸化装置で処理された処理水を電気脱イオン装置の電極室に流通すると、電気脱イオン装置の電極及び電極室内のイオン交換体の劣化やスケール生成が促進される。そこで、電気脱イオン装置の脱塩室の処理水の一部を電気脱イオン装置の電極室に通水することで、電気脱イオン装置の電極及び電極室内のイオン交換体の劣化やスケール生成を抑制することができ、電気脱イオン装置を長期間安定して運転することができる。 According to this invention (invention 6), when the treated water treated by the reverse osmosis membrane device or the ultraviolet oxidation device is passed through the electrode chamber of the electrodeionization device, the electrode of the electrodeionization device and the ion exchanger in the electrode chamber deterioration and scale formation are accelerated. Therefore, by passing part of the treated water in the desalting chamber of the electrodeionization apparatus through the electrode chamber of the electrodeionization apparatus, the deterioration and scale formation of the electrodes and the ion exchanger in the electrode chamber of the electrodeionization apparatus can be prevented. can be suppressed, and the electrodeionization apparatus can be stably operated for a long period of time.

本発明の純水製造装置によれば、電気脱イオン装置の脱塩室を通過した処理水の一部を前記脱塩室と逆方向に濃縮室に通水するとともに、逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ以上となったら脱塩室流量を５０～１００％未満に減少させるように制御することができるので、水質の低下を抑制し、所定の水質の純水を安定的に製造することが可能となる。 According to the pure water production apparatus of the present invention, part of the treated water that has passed through the deionization chambers of the electrodeionization device is passed through the concentration chambers in the opposite direction to the deionization chambers, and the water is treated by the reverse osmosis membrane device. When the electrical conductivity of water reaches 0.3 mS/m or more, the demineralization chamber flow rate can be controlled to be reduced to less than 50% to less than 100%. It becomes possible to manufacture stably.

本発明の一実施形態による純水製造装置の運転方法を適用可能な一次純水製造装置を備えた超純水製造システムを示すフロー図である。1 is a flow chart showing an ultrapure water production system equipped with a primary pure water production device to which a pure water production device operating method according to an embodiment of the present invention can be applied; FIG. 前記実施形態よる純水製造装置の運転方法における電気脱イオン装置の構造の一例を示す概略図である。It is a schematic diagram showing an example of the structure of the electrodeionization apparatus in the operation method of the pure water production apparatus according to the embodiment. 実施例１で用いた電気脱イオン装置の構造を示す概略図である。1 is a schematic diagram showing the structure of an electrodeionization apparatus used in Example 1. FIG. 実施例１の純水製造装置の運転方法における電気脱イオン装置の処理水の抵抗率の変化を示すグラフである。5 is a graph showing changes in resistivity of treated water of the electrodeionization apparatus in the operation method of the pure water production apparatus of Example 1. FIG. 比較例１で用いた電気脱イオン装置の構造を示す概略図である。1 is a schematic diagram showing the structure of an electrodeionization apparatus used in Comparative Example 1. FIG. 比較例１の純水製造装置の運転方法における電気脱イオン装置の処理水の抵抗率の変化を示すグラフである。5 is a graph showing changes in resistivity of treated water of the electrodeionization apparatus in the operating method of the pure water production apparatus of Comparative Example 1. FIG. 実施例２の電気脱イオン装置を用いた試験装置を示す概略図である。2 is a schematic diagram showing a test apparatus using the electrodeionization apparatus of Example 2. FIG. 実施例２における電気脱イオン装置の処理水の抵抗率の変化を示すグラフである。5 is a graph showing changes in resistivity of treated water of the electrodeionization apparatus in Example 2. FIG. 比較例２の電気脱イオン装置を用いた試験装置を示す概略図である。3 is a schematic diagram showing a test apparatus using the electrodeionization apparatus of Comparative Example 2. FIG. 比較例２における電気脱イオン装置の処理水の抵抗率の変化を示すグラフである。7 is a graph showing changes in resistivity of treated water of an electrodeionization apparatus in Comparative Example 2. FIG.

以下、本発明の一実施形態による純水製造装置の運転方法について添付図面を参照に説明する。 A method of operating a pure water production apparatus according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

［純水製造装置］
図１は本実施形態の純水製造装置の運転方法を適用可能な超純水製造システムを示すフロー図であり、逆浸透膜装置５の処理水の導電率を測定する計測手段（図示せず）と、この計測手段の測定値に基づいて電気脱イオン装置８の脱塩室に供給する水量を制御する制御手段（図示せず）とを有する以外は、前述した従来例と同じであるので、その詳細な説明を省略する。この超純水製造システム１の純水製造装置としての一次純水製造装置３では、紫外線酸化装置６の処理水を電気脱イオン装置８に通水する。 [Pure water production equipment]
FIG. 1 is a flow diagram showing an ultrapure water production system to which the operation method of the pure water production apparatus of the present embodiment can be applied. ) and a control means (not shown) for controlling the amount of water supplied to the deionization chamber of the electrodeionization apparatus 8 based on the measured value of the measurement means, the apparatus is the same as the conventional example described above. , the detailed description thereof will be omitted. In the primary pure water production device 3 as the pure water production device of this ultrapure water production system 1 , the water treated by the ultraviolet oxidation device 6 is passed through the electrodeionization device 8 .

（電気脱イオン装置）
図２において、電気脱イオン装置８は、電極（陽極２１、陰極２２）の間に複数のアニオン交換膜２３及びカチオン交換膜２４を交互に配列して脱塩室２５と濃縮室２６とを交互に形成し、両側に陽極室２７と陰極室２８を形成したものであり、脱塩室２５にはイオン交換樹脂、イオン交換繊維もしくはグラフト交換体等からなるイオン交換体（アニオン交換体及びカチオン交換体）が混合もしくは複層状に充填されている。また、濃縮室２６と、陽極室２７及び陰極室２８にも、同様にイオン交換体が充填されている。 (Electrodeionization device)
In FIG. 2, the electrodeionization apparatus 8 alternately arranges a plurality of anion exchange membranes 23 and cation exchange membranes 24 between electrodes (anode 21 and cathode 22) to alternately demineralize compartments 25 and concentrate compartments 26. An anode chamber 27 and a cathode chamber 28 are formed on both sides, and an ion exchanger (anion exchanger and cation exchanger) made of ion exchange resin, ion exchange fiber, graft exchanger, or the like is contained in the desalting chamber 25. body) is mixed or filled in multiple layers. The concentrating compartment 26, the anode compartment 27 and the cathode compartment 28 are similarly filled with ion exchangers.

そして、この電気脱イオン装置８には、脱塩室２５に紫外線酸化装置６で処理した被処理水Ｗ４を通水して脱塩水Ｗ５を取り出し、濃縮室２６にこの脱塩水Ｗ５を分取して通水する濃縮室通水手段（図示せず）が設けられていて、脱塩水Ｗ５を脱塩室２５の脱塩水Ｗ５の取り出し口に近い側から濃縮室２６内に導入すると共に、脱塩室２５の処理原水（被処理水Ｗ４）の入口に近い側から流出する、すなわち脱塩室２５における被処理水Ｗ４の流通方向と反対方向から脱塩水Ｗ５を濃縮室２６に導入して濃縮水Ｗ６を吐出する構成となっている。一方、陽極室２７及び陰極室２８にも脱塩水Ｗ５を分取して電極水として流通させ、それぞれ陽極排出水Ｗ７、陰極排出水Ｗ８として排出する構造となっている。 In the electrodeionization apparatus 8, water to be treated W4 treated by the ultraviolet oxidation apparatus 6 is passed through the demineralization chamber 25 to take out the demineralized water W5. desalted water W5 is introduced into the concentrating chamber 26 from the side near the outlet of the desalted water W5 of the desalting chamber 25, and desalting is performed. Demineralized water W5 is introduced into the concentrating chamber 26 from the side near the entrance of the raw water (to-be-treated water W4) of the chamber 25, that is, from the direction opposite to the direction of flow of the to-be-treated water W4 in the demineralizing chamber 25, to obtain concentrated water. It is configured to eject W6. On the other hand, the desalted water W5 is divided into the anode chamber 27 and the cathode chamber 28 and circulated as electrode water, and discharged as anode discharge water W7 and cathode discharge water W8, respectively.

［純水製造装置の運転方法］
上述したような構成を有する一次純水製造装置３の運転方法について図１及び図２を参照して説明する。まず、原水Ｗを前処理装置２により前処理を施した前処理水Ｗ１を一次純水製造装置３に供給し、逆浸透膜（ＲＯ）装置５の給水に図示しないアルカリ添加手段からＮａＯＨ等のアルカリを注入してｐＨ８．５以上とする。逆浸透膜（ＲＯ）装置５で塩類のほかイオン性、コロイド性のＴＯＣを除去するとともに炭酸ガスをイオン化して除去する。そして、紫外線酸化装置６において残存する有機物を分解する。この紫外線酸化装置６で処理した被処理水Ｗ４を電気脱イオン装置８に通水して、ＵＶ酸化により分解した有機物に起因するイオン性の不純物を除去して、一次純水Ｗ２を製造する。 [Method of operating pure water production device]
A method of operating the primary pure water production apparatus 3 having the above-described configuration will be described with reference to FIGS. 1 and 2. FIG. First, the raw water W is pretreated by the pretreatment device 2, and the pretreated water W1 is supplied to the primary pure water production device 3. Alkali is injected to make pH 8.5 or higher. A reverse osmosis membrane (RO) device 5 removes ionic and colloidal TOC in addition to salts and ionizes and removes carbon dioxide gas. Then, the remaining organic matter is decomposed in the ultraviolet oxidation device 6 . The water to be treated W4 treated by the ultraviolet oxidation device 6 is passed through an electrodeionization device 8 to remove ionic impurities caused by organic matter decomposed by UV oxidation to produce primary pure water W2.

具体的には、図２に示すように電気脱イオン装置８の脱塩室２５に紫外線酸化装置６の処理水を被処理水Ｗ４として供給する。そして、この脱塩室２５を透過した脱塩水Ｗ５を分取して濃縮室２６及び電極室（陽極室２７、陰極室２８）に供給とする。従来のように紫外線酸化装置６の処理水（被処理水Ｗ４）を電気脱イオン装置８の濃縮室２６及び電極室（陽極室２７、陰極室２８）に流通すると、被処理水Ｗ４には過酸化水素なども含まれているので、電気脱イオン装置８の電極２１，２２や濃縮室２６や陽極室２７又は陰極室２８内のイオン交換体の劣化が促進される。そこで、濃縮室２６と陽極室２７及び陰極室２８に脱塩水Ｗ５を供給することで、電気脱イオン装置８の電極２１，２２や濃縮室２６や陽極室２７又は陰極室２８内のイオン交換体の劣化を抑制することができ、電気脱イオン装置８の運転電圧の上昇を抑制し、耐用期間を長期化することができる。 Specifically, as shown in FIG. 2, the treated water from the ultraviolet oxidation device 6 is supplied to the demineralization chamber 25 of the electrodeionization device 8 as the water to be treated W4. Then, the desalted water W5 that has passed through the desalting chamber 25 is collected and supplied to the concentrating chamber 26 and the electrode chambers (anode chamber 27 and cathode chamber 28). When the treated water (water to be treated W4) of the ultraviolet oxidation device 6 flows through the concentrating chamber 26 and the electrode chambers (anode chamber 27 and cathode chamber 28) of the electrodeionization device 8 as in the conventional case, the water to be treated W4 is saturated. Since it also contains hydrogen oxide, the deterioration of the electrodes 21 and 22 of the electrodeionization apparatus 8, the ion exchangers in the concentration chamber 26, the anode chamber 27, or the cathode chamber 28 is accelerated. Therefore, by supplying demineralized water W5 to the concentration chamber 26, the anode chamber 27 and the cathode chamber 28, the electrodes 21 and 22 of the electrodeionization apparatus 8, the ion exchangers in the concentration chamber 26, the anode chamber 27 and the cathode chamber 28 can be suppressed, the operating voltage of the electrodeionization device 8 can be suppressed, and the service life can be lengthened.

特に、電気脱イオン装置８として、脱塩室２５を通過した脱塩水Ｗ５の一部を被濃縮水として濃縮室２６に脱塩室２５の通水方向とは逆方向に向流一過式で通水し、濃縮室２６から濃縮水Ｗ６を系外へ排出させているので、脱塩室２５の取り出し側ほど濃縮室２６の被濃縮水中のイオン濃度が低いものとなり、濃度拡散による脱塩室２５への影響が小さくなるため、ホウ素などの弱イオンの除去率が向上している。 In particular, in the electrodeionization apparatus 8, part of the desalted water W5 that has passed through the desalting chambers 25 is used as the water to be concentrated, and is passed through the concentrating chambers 26 in a direction opposite to the water flow direction of the desalting chambers 25. Since the water is passed through and the concentrated water W6 is discharged from the concentration chamber 26 to the outside of the system, the concentration of ions in the water to be concentrated in the concentration chamber 26 becomes lower toward the take-out side of the deionization chamber 25, and the deionization chamber is caused by concentration diffusion. Since the effect on 25 is reduced, the removal rate of weak ions such as boron is improved.

本実施形態においては、上述したような一次純水Ｗ２の製造プロセスにおいて、図示しない計測手段により逆浸透膜装置５の処理水の導電率を測定し、逆浸透膜装置５の処理水の導電率が０．３ｍＳ／ｍ未満の場合を通常状態として、その際の電気脱イオン装置８の脱塩室２５への給水量を１００％として設定する。そして、逆浸透膜装置５の処理水の導電率が０．３ｍＳ／ｍ以上となったら脱塩室２５への被処理水Ｗ４の流量を５０～１００％未満に減少させるように制御する。被処理水Ｗ４の流量を５０％以下としてもそれ以上の脱塩水Ｗ５の水質の安定が得られないばかりか、一次純水Ｗ２の製造量が低下する。この脱塩室２５への被処理水Ｗ４の流量の制御は、逆浸透膜装置５の被処理水Ｗ４の導電率の値に対応して、連続的もしくは段階的に変動させるのが一般的であるが、固定値として設定してもよい。上述したような被処理水Ｗ４の脱塩室２５への供給量は、例えば、電気脱イオン装置８の脱塩室２５への被処理水Ｗ４の供給路に分岐菅を設け、この分岐菅への被処理水Ｗ４の流量を増減させることにより、脱塩室２５への被処理水Ｗ４の供給量を制御すればよい。 In this embodiment, in the process of producing the primary pure water W2 as described above, the conductivity of the treated water of the reverse osmosis membrane device 5 is measured by measuring means (not shown), and the conductivity of the treated water of the reverse osmosis membrane device 5 is is less than 0.3 mS/m as a normal state, and the amount of water supplied to the deionization chamber 25 of the electrodeionization apparatus 8 at that time is set as 100%. Then, when the conductivity of the treated water of the reverse osmosis membrane device 5 reaches 0.3 mS/m or more, the flow rate of the treated water W4 to the demineralization chamber 25 is controlled to be reduced to 50 to less than 100%. Even if the flow rate of the water W4 to be treated is set to 50% or less, the quality of the desalted water W5 cannot be stabilized further, and the production amount of the primary pure water W2 decreases. The control of the flow rate of the water W4 to be treated to the demineralization chamber 25 is generally performed by varying it continuously or stepwise according to the value of the conductivity of the water W4 to be treated in the reverse osmosis membrane device 5. However, it may be set as a fixed value. The supply amount of the water to be treated W4 to the desalting chamber 25 as described above can be determined, for example, by providing a branch pipe in the supply path of the water to be treated W4 to the desalting chamber 25 of the electrodeionization apparatus 8, The amount of water to be treated W4 supplied to the demineralization chamber 25 may be controlled by increasing or decreasing the flow rate of the water to be treated W4.

このような制御を行うのは以下のような理由による。すなわち、逆浸透膜装置８の処理水の水質が低下した場合には、これを処理する電気脱イオン装置８に負荷がかかり、電気脱イオン装置８の脱塩室２５の処理水（脱塩水）Ｗ５の水質の低下を招くおそれがある。そこで、逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ以上となったら、電気脱イオン装置８の負荷を低減するために脱塩室２５の流量を減少させるように制御する。この場合、脱塩室２５に供給する被処理水Ｗ４と、濃縮室２６に供給する濃縮水とを同じ方向に通水すると、脱塩室２５のイオン交換樹脂に吸着していたイオンは濃縮室２６に移動し、濃縮室２６のイオン濃度が増加することにより、濃縮室２６から脱塩室２５へのイオンの逆拡散が増加し、処理水（脱塩水）Ｗ５の水質が低下する。これに対し、本実施形態においては、電気脱イオン装置８の脱塩室２５を通過した処理水（脱塩水）Ｗ５の一部を該脱塩室２５と逆方向に濃縮室２６に通水することにより、濃縮室２６の下部のイオン濃度を低く維持することができるので、電気脱イオン装置８の処理水（脱塩水）Ｗ５の水質の低下を抑制することができる。 Such control is performed for the following reasons. That is, when the water quality of the treated water of the reverse osmosis membrane device 8 deteriorates, the electrodeionization device 8 that processes it is overloaded, and the treated water (demineralized water) in the desalination chamber 25 of the electrodeionization device 8 There is a possibility of causing deterioration of the water quality of W5. Therefore, when the conductivity of the treated water of the reverse osmosis membrane device becomes 0.3 mS/m or more, the flow rate of the deionization chamber 25 is controlled to decrease in order to reduce the load on the electrodeionization device 8 . In this case, when the water to be treated W4 supplied to the desalting chambers 25 and the concentrated water supplied to the concentrating chambers 26 are passed in the same direction, the ions adsorbed on the ion exchange resin in the desalting chambers 25 are removed from the concentrating chambers. 26, the concentration of ions in the concentration compartment 26 increases, the reverse diffusion of ions from the concentration compartment 26 to the demineralization compartment 25 increases, and the water quality of the treated water (demineralized water) W5 deteriorates. In contrast, in the present embodiment, part of the treated water (demineralized water) W5 that has passed through the demineralization chambers 25 of the electrodeionization apparatus 8 is passed through the concentrating chambers 26 in the opposite direction to the demineralization chambers 25. As a result, the ion concentration in the lower portion of the concentrating chamber 26 can be maintained low, so that deterioration of water quality of the treated water (demineralized water) W5 of the electrodeionization apparatus 8 can be suppressed.

このようにして一次純水Ｗ２を製造したら、サブタンク１０に貯留し、この一次純水Ｗ２を供給ポンプ１１により供給して処理する。サブシステム４では、紫外線酸化装置６と非再生型混床式イオン交換装置１３と限外ろ過膜１４とによる処理を行う。紫外線酸化装置６では、ＵＶランプより出される波長１８５ｎｍの紫外線によりＴＯＣを有機酸さらにはＣＯ２レベルにまで分解する。分解された有機酸及びＣＯ２は後段の非再生型混床式イオン交換装置１３で除去される。限外ろ過膜１４では、微小粒子が除去され、非再生型混床式イオン交換装置１３の流出粒子も除去され、二次純水（超純水）Ｗ３を製造することができる。そして、この超純水Ｗ３はユースポイント１５に供給された後、未使用分がサブタンク１０に返送することで、超純水製造システム１を運転することができる。 After the primary pure water W2 is produced in this manner, it is stored in the sub-tank 10, and the primary pure water W2 is supplied by the supply pump 11 and processed. In the subsystem 4 , treatment is performed by an ultraviolet oxidation device 6 , a non-regenerative mixed-bed ion exchange device 13 and an ultrafiltration membrane 14 . In the ultraviolet oxidizer 6, the TOC is decomposed into organic acids and further down to the level of CO 2 by ultraviolet rays with a wavelength of 185 nm emitted from a UV lamp. The decomposed organic acid and CO 2 are removed in the non-regenerative mixed-bed ion exchange unit 13 in the latter stage. The ultrafiltration membrane 14 removes microparticles, and also removes particles flowing out of the non-regenerative mixed-bed ion exchange device 13, so that secondary pure water (ultrapure water) W3 can be produced. After the ultrapure water W3 is supplied to the point of use 15, the unused portion is returned to the sub-tank 10, whereby the ultrapure water production system 1 can be operated.

以上、本発明について前記実施形態に基づき説明してきたが、本発明は前記実施形態に限定されず、種々の変更実施が可能である。例えば、本発明において適用可能な超純水製造システム１としては、一次純水製造装置３が逆浸透膜装置５の処理水を電気脱イオン装置８で処理する構成であれば、紫外線酸化装置６を必ずしも有する必要はなく、その他種々の構成のものに適用可能である。またサブシステム４の構成も特に制限はなく、汎用的な種々の構成を適用可能である。 Although the present invention has been described above based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications can be made. For example, as the ultrapure water production system 1 applicable in the present invention, if the primary pure water production device 3 is configured to treat the treated water of the reverse osmosis membrane device 5 with the electrodeionization device 8, the ultraviolet oxidation device 6 , and can be applied to various other configurations. Also, the configuration of the subsystem 4 is not particularly limited, and various general-purpose configurations can be applied.

以下の具体的実施例に基づき、本発明をさらに詳細に説明する。 The present invention will be described in more detail based on the following specific examples.

〔実施例１〕
図３及び表１に示す構造の試験用の電気脱イオン装置に表２に示す通水条件で表３に示す給水（被処理水）を脱塩室２５に通水し、電気脱イオン装置は定電流運転とした。そして、給水（被処理水）にＮａＯＨを添加して、ｐＨ１０．５とした後の処理水の抵抗率を測定した。結果を図４に示す。なお、給水の初期導電率は０．２５ｍＳ／ｍであり、ＮａＯＨを添加後の給水の導電率は、６．８ｍＳ／ｍであった。 [Example 1]
The test electrodeionization apparatus having the structure shown in FIG. Constant current operation was used. Then, NaOH was added to the water supply (water to be treated) to adjust the pH to 10.5, and then the resistivity of the treated water was measured. The results are shown in FIG. The initial conductivity of the feed water was 0.25 mS/m, and the conductivity of the feed water after adding NaOH was 6.8 mS/m.

Figure 2023112836000002
Figure 2023112836000002

Figure 2023112836000003
Figure 2023112836000003

Figure 2023112836000004
Figure 2023112836000004

〔比較例１〕
実施例１において、試験用の電気脱イオン装置として、図５に示すように被処理水Ｗ４を並行して、脱塩室２５及び濃縮室２６に供給する構造とした以外は同様にして、ＮａＯＨを添加後の処理水の抵抗率を測定した。結果を図６に示す。 [Comparative Example 1]
In the same manner as in Example 1, except that the test electrodeionization apparatus was configured such that the water to be treated W4 was supplied in parallel to the desalting chamber 25 and the concentrating chamber 26 as shown in FIG. was measured. The results are shown in FIG.

図４及び図６から明らかなとおり、実施例１においては、ＮａＯＨの添加により電気脱イオン装置の処理水（脱塩水）の抵抗率の変化はほとんどなかった。これは、処理水（脱塩水）を濃縮室２６に通水することにより、濃縮室２６から脱塩室２５へのイオンの拡散が防止されたためであると考えられる。これに対し、比較例１ではＮａＯＨの添加により電気脱イオン装置の処理水（脱塩水）の抵抗率が大きく低下した。これは、濃縮室２６のＮａ濃度が増加したことにより、濃縮室２６から脱塩室へのイオンの拡散が起こったためであると考えられる。 As is clear from FIGS. 4 and 6, in Example 1, the addition of NaOH hardly changed the resistivity of the treated water (demineralized water) of the electrodeionization apparatus. This is probably because the diffusion of ions from the concentration chamber 26 to the demineralization chamber 25 was prevented by passing the treated water (demineralized water) through the concentration chamber 26 . In contrast, in Comparative Example 1, addition of NaOH significantly lowered the resistivity of the treated water (demineralized water) of the electrodeionization apparatus. It is believed that this is because the concentration of Na in the concentrating compartments 26 increased, causing ions to diffuse from the concentrating compartments 26 to the desalting compartments.

〔実施例２〕
図７に示す電気脱イオン装置の制御用の試験装置を用意した。この試験装置５１は、超純水（ＵＰＷ）流路５２と、電気脱イオン装置５３と、脱塩水流路５４と、濃縮水流路５５と、超純水（ＵＰＷ）流路５２の分岐管５６とを有し、脱塩水流路５４には、流量計５８Ａと比抵抗値計５９がそれぞれ接続されている。また、濃縮水流路５５には、流量計５８Ｂと導電率計５７Ａとがそれぞれ接続されている。さらに、分岐管５６には、流量計５８Ｃと導電率計５７Ｂとがそれぞれ接続されている。そして、超純水流路５２にはシリカ（ＳｉＯ２）源としてケイ酸ナトリウム（Ｎａ２ＳｉＯ３）溶液タンク６１と、炭酸ナトリウ（ＮａＨＣＯ３）溶液タンク６２と、ホウ素源として水酸化ホウ素（Ｂ（ＯＨ）３）溶液タンク６３とがそれぞれ薬液ポンプ６１Ａ，６２Ａ，６３Ａを介して接続した構成を有する。なお、電気脱イオン装置５３としては、ＩＰ－ＬＸＭＸ４－４（Ｅｖｏｑｕａ社製）を用いて、濃縮室には脱塩室の処理水（脱塩水）を逆方向に通水する構成とした。 [Example 2]
A test apparatus for controlling the electrodeionization apparatus shown in FIG. 7 was prepared. This test apparatus 51 includes an ultrapure water (UPW) channel 52, an electrodeionization device 53, a demineralized water channel 54, a concentrated water channel 55, and a branch pipe 56 of the ultrapure water (UPW) channel 52. A flow meter 58A and a resistivity meter 59 are connected to the desalted water flow path 54, respectively. A flow meter 58B and a conductivity meter 57A are connected to the concentrated water flow path 55, respectively. Furthermore, a flow meter 58C and a conductivity meter 57B are connected to the branch pipe 56, respectively. In the ultrapure water channel 52, a sodium silicate (Na 2 SiO 3 ) solution tank 61 as a silica (SiO 2 ) source, a sodium carbonate (NaHCO 3 ) solution tank 62, and a boron source of boron hydroxide (B( OH) 3 ) and a solution tank 63 are connected via chemical pumps 61A, 62A and 63A, respectively. IP-LXMX4-4 (manufactured by Evoqua) was used as the electrodeionization device 53, and the treated water (demineralized water) from the demineralization chamber was passed through the concentrating chamber in the opposite direction.

上述したような試験装置において、電気脱イオン装置５３に、表４に示す通水条件及び表５に示す給水条件において、電気脱イオン装置５３を定電流運転し、脱塩室流量を１００％（４．７Ｌ／分）から６０％（２，４Ｌ／分）に減少させ、再度１００％（４．７Ｌ／分）に変化させたときの処理水（脱塩水）の抵抗率を測定した。結果を図８に示す。 In the test apparatus as described above, the electrodeionization device 53 is operated at a constant current under the water supply conditions shown in Table 4 and the water supply conditions shown in Table 5, and the deionization chamber flow rate is set to 100% ( 4.7 L/min) to 60% (2.4 L/min) and again to 100% (4.7 L/min), the resistivity of the treated water (demineralized water) was measured. The results are shown in FIG.

Figure 2023112836000005
Figure 2023112836000005

Figure 2023112836000006
Figure 2023112836000006

〔比較例２〕
図９に示す電気脱イオン装置の制御用の試験装置を用意した。この試験装置５１Ａは、前述した実施例２の試験装置において、電気脱イオン装置５３の脱塩室と濃縮室に給水を並行方向に供給する構造を有する以外、基本的に同じ構成を有する。 [Comparative Example 2]
A test apparatus for controlling the electrodeionization apparatus shown in FIG. 9 was prepared. This test apparatus 51A has basically the same configuration as the test apparatus of the second embodiment described above, except that it has a structure in which water is supplied in parallel to the desalting chamber and the concentration chamber of the electrodeionization device 53 .

この試験装置において、電気脱イオン装置５３に、表４に示す通水条件及び表５に示す給水条件において、電気脱イオン装置５３を定電流運転し、脱塩室流量を１００％（４．７Ｌ／分）から６０％（２，４Ｌ／分）に減少させ、再度１００％（４．７Ｌ／分）に変化させたときの処理水（脱塩水）の抵抗率を測定した。結果を図１０に示す。 In this test apparatus, the electrodeionization device 53 is operated at a constant current under the water supply conditions shown in Table 4 and the water supply conditions shown in Table 5, and the deionization chamber flow rate is set to 100% (4.7 L). /min) to 60% (2.4 L/min) and again to 100% (4.7 L/min), the resistivity of the treated water (demineralized water) was measured. The results are shown in FIG.

Figure 2023112836000007
Figure 2023112836000007

図８及び図１０から明らかなように、実施例２によれば、脱塩室への流量を６０％に減少させると処理水の抵抗率が増加し水質が向上し、再度流量を増加させてもほとんど水質の低下が起こっていないことがわかる。これに対し、比較例２では、脱塩室への流量を低下させることにより、処理水の抵抗率が増加することはないばかりか、流量減少直後には一時的に、抵抗率が減少し、水質低下が発生することがわかる。 As is clear from FIGS. 8 and 10, according to Example 2, when the flow rate to the demineralization chamber was reduced to 60%, the resistivity of the treated water increased and the water quality improved. It can be seen that there is almost no deterioration in water quality. In contrast, in Comparative Example 2, the resistivity of the treated water did not increase by reducing the flow rate to the demineralization chamber, and the resistivity decreased temporarily immediately after the flow rate decreased. It can be seen that water quality deterioration occurs.

これは、比較例２においては、脱塩室流量が減少すると、脱塩室の吸着帯が短縮する。そうすると、脱塩室のイオン交換樹脂に吸着していたイオンは濃縮室に移動する。そのため、濃縮室のイオン濃度が増加する。これにより、濃縮室から脱塩室へのイオンの逆拡散が増加し、処理水の抵抗率が減少する。これに対し、実施例２では処理水カウンターフローとしているので、処理水を濃縮室に通水することにより、濃縮室下部のイオン濃度が低く保たれるため、比較例２のような現象が起こらなかったと考えられる。 This is because, in Comparative Example 2, when the flow rate in the deionization chamber decreases, the adsorption band in the deionization chamber shortens. Then, the ions adsorbed on the ion exchange resin in the desalting compartment move to the concentrating compartment. Therefore, the concentration of ions in the concentrating compartment increases. This increases the back diffusion of ions from the concentrating compartments to the desalting compartments and reduces the resistivity of the treated water. On the other hand, in Example 2, since the treated water is counter-flowed, the ion concentration in the lower part of the concentration chamber is kept low by passing the treated water through the concentration chamber. It is thought that there was not.

１ 超純水製造システム
２ 前処理装置
３ 一次純水製造装置（純水製造装置）
４ サブシステム
５ 逆浸透膜装置
６ 紫外線酸化装置
７ 給水ポンプ
８ 電気脱イオン装置
１０ サブタンク
１１ 供給ポンプ
１２ 紫外線酸化装置
１３ 非再生型混床式イオン交換装置
１４ 限外ろ過膜（ＵＦ膜）
１５ ユースポイント
２１ 陽極（電極）
２２ 陰極（電極）
２３ アニオン交換膜
２４ カチオン交換膜
２５ 脱塩室
２６ 濃縮室
２７ 陽極室
２８ 陰極室
Ｗ 原水
Ｗ１ 前処理水
Ｗ２ 一次純水（純水）
Ｗ３ 超純水
Ｗ４ 被処理水
Ｗ５ 脱塩水
Ｗ６ 濃縮水
Ｗ７ 陽極排出水
Ｗ８ 陰極排出水 1 Ultrapure water production system 2 Pretreatment device 3 Primary pure water production device (pure water production device)
4 Subsystem 5 Reverse osmosis membrane device 6 Ultraviolet oxidation device 7 Water supply pump 8 Electrodeionization device 10 Subtank 11 Supply pump 12 Ultraviolet oxidation device 13 Non-regenerative mixed-bed ion exchange device 14 Ultrafiltration membrane (UF membrane)
15 point of use 21 anode (electrode)
22 cathode (electrode)
23 Anion exchange membrane 24 Cation exchange membrane 25 Demineralization compartment 26 Concentration compartment 27 Anode compartment 28 Cathode compartment W Raw water W1 Pretreated water W2 Primary pure water (pure water)
W3 Ultrapure water W4 Water to be treated W5 Demineralized water W6 Concentrated water W7 Anode discharge water W8 Cathode discharge water

Claims (6)

逆浸透膜装置と電気脱イオン装置とをこの順に備え、前記電気脱イオン装置の脱塩室にこの逆浸透膜装置の処理水を通水するとともに該脱塩室を通過した処理水の一部を前記脱塩室と逆方向に濃縮室に通水する純水製造装置であって、
前記逆浸透膜装置の処理水の導電率又は比抵抗値を測定する計測手段と、前記計測手段の測定値に基づいて前記電気脱イオン装置の脱塩室に供給する水量を制御する制御手段とを有し、
前記制御手段は、前記計測手段の測定値に基づく逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ未満の場合の前記脱塩室への流量を１００％とした場合に、該逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ以上となったら該脱塩室流量を５０～１００％未満に減少させるように制御する、純水製造装置。 A reverse osmosis membrane device and an electrodeionization device are provided in this order, and the treated water of the reverse osmosis membrane device is passed through the desalination chamber of the electrodeionization device and part of the treated water that has passed through the desalination chamber. is passed through the concentrating chamber in a direction opposite to the desalting chamber,
measuring means for measuring the conductivity or specific resistance value of the treated water of the reverse osmosis membrane device; and control means for controlling the amount of water supplied to the desalting chamber of the electrodeionization device based on the measured value of the measuring means. has
The control means controls the reverse A water purifying apparatus, wherein the demineralization chamber flow rate is controlled to be reduced to less than 50 to less than 100% when the conductivity of treated water in the osmosis membrane apparatus reaches 0.3 mS/m or more. 前記逆浸透膜装置と前記電気脱イオン装置との間に紫外線酸化装置を有する、請求項１に記載の純水製造装置。 2. The pure water production system according to claim 1, further comprising an ultraviolet oxidation device between said reverse osmosis membrane device and said electrodeionization device. 前記電気脱イオン装置が、脱塩室の処理水の一部を該電気脱イオン装置の電極室に通水する、請求項１又は２に記載の純水製造装置。 3. The pure water production apparatus according to claim 1, wherein said electrodeionization device passes a part of the treated water in the deionization chamber to the electrode chamber of said electrodeionization device. 逆浸透膜装置と電気脱イオン装置とをこの順に備え、前記逆浸透膜装置にｐＨ８．５以上の給水を供給し、前記電気脱イオン装置の脱塩室にこの逆浸透膜装置の処理水を通水するとともに該脱塩室を通過した処理水の一部を前記脱塩室と逆方向に濃縮室に通水する純水製造装置の運転方法であって、
前記逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ未満の場合の前記脱塩室への流量を１００％とした場合に、前記逆浸透膜装置の処理水の導電率が０．３ｍＳ／ｍ以上となったら該脱塩室流量を５０～１００％未満に減少させるように制御する、純水製造装置の運転方法。 A reverse osmosis membrane device and an electrodeionization device are provided in this order, water having a pH of 8.5 or higher is supplied to the reverse osmosis membrane device, and treated water from the reverse osmosis membrane device is supplied to a desalination chamber of the electrodeionization device. A method of operating a water purifying apparatus in which part of the treated water that has passed through the desalting chambers is passed through the concentrating chambers in a direction opposite to that of the desalting chambers, the method comprising:
Assuming that the flow rate to the desalting chamber is 100% when the conductivity of the treated water of the reverse osmosis membrane device is less than 0.3 mS/m, the conductivity of the treated water of the reverse osmosis membrane device is 0.3 mS/m. A method of operating a pure water production apparatus, wherein the demineralization chamber flow rate is controlled to be reduced to less than 50% to less than 100% when the flow rate is 3 mS/m or more. 前記純水製造装置が、前記逆浸透膜装置と前記電気脱イオン装置との間に紫外線酸化装置を有する、請求項４に記載の純水製造装置の運転方法。 5. The method of operating a water purifier according to claim 4, wherein said water purifier has an ultraviolet oxidation device between said reverse osmosis membrane device and said electrodeionization device. 前記電気脱イオン装置の脱塩室の処理水の一部を該電気脱イオン装置の電極室に通水する、請求項４又は５に記載の純水製造装置の運転方法。 6. The method of operating a pure water production apparatus according to claim 4, wherein a portion of the treated water in the desalting chamber of said electrodeionization device is passed through the electrode chamber of said electrodeionization device.
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