JPH0957261A - Two-stage type reverse osmosis membrane treatment - Google Patents
Two-stage type reverse osmosis membrane treatmentInfo
- Publication number
- JPH0957261A JPH0957261A JP24543495A JP24543495A JPH0957261A JP H0957261 A JPH0957261 A JP H0957261A JP 24543495 A JP24543495 A JP 24543495A JP 24543495 A JP24543495 A JP 24543495A JP H0957261 A JPH0957261 A JP H0957261A
- Authority
- JP
- Japan
- Prior art keywords
- reverse osmosis
- osmosis membrane
- water
- raw water
- raw
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Physical Water Treatments (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、原水から逆浸透膜
法により一次透過水を得る第１次逆浸透膜工程と、一次
透過水から逆浸透膜法により二次透過水を得る第２次逆
浸透膜工程とを備える２段式逆浸透膜処理方法に関し、
更に詳細には、発電所のボイラー用補給水として、半導
体装置の製造工場或いはその他の工場で使用する純水と
して、更にはそれらの工場で使用される超純水を製造す
るための原水として最適な純水を製造する２段式逆浸透
膜処理方法に関する。TECHNICAL FIELD The present invention relates to a primary reverse osmosis membrane process for obtaining primary permeated water from raw water by a reverse osmosis membrane method, and a secondary reverse osmosis membrane process for obtaining secondary permeated water from primary permeate water by a reverse osmosis membrane method. A two-stage reverse osmosis membrane treatment method comprising a reverse osmosis membrane step,
More specifically, it is optimal as make-up water for boilers at power plants, as pure water used in semiconductor device manufacturing factories or other factories, and as raw water for producing ultrapure water used in those factories. The present invention relates to a two-stage reverse osmosis membrane treatment method for producing pure water.
【０００２】[0002]
【従来の技術】半導体装置の微細化及び高集積化の傾向
と共に、半導体装置の製造工程で使用される超純水の水
質に対する要求は、益々厳しくなっている。そのため
に、超純水を製造するための原水、即ち純水に対して
も、益々高いレベルの水質、例えば従来に比べて電気伝
導率の一層低い純水が要求されている。ところで、従
来、純水の製造に当たっては、原水を主としてイオン交
換装置により処理して純水を得て来たが、イオン交換樹
脂を再生する薬剤を必要とするとともに再生の際に排出
される再生廃液の処理設備を必要とするので、イオン交
換装置を小型化して再生薬剤の使用量を減少させるとと
もに再生廃液の排出量を減少させたいと言う要求が高ま
っている。更には、純水製造装置の敷地面積を節減する
ためにイオン交換装置および再生廃液の処理設備を小型
化して装置の省スペース化を図ることが必要になってい
る。2. Description of the Related Art With the trend toward miniaturization and high integration of semiconductor devices, the demand for water quality of ultrapure water used in the manufacturing process of semiconductor devices is becoming more and more severe. Therefore, even with respect to raw water for producing ultrapure water, that is, pure water, there is a demand for ever-higher levels of water quality, for example, pure water having a lower electric conductivity than conventional ones. By the way, in the past, in the production of pure water, raw water was mainly processed by an ion exchange device to obtain pure water. However, a chemical that regenerates the ion exchange resin is required, and regeneration that is discharged during regeneration is required. Since a waste liquid treatment facility is required, there is an increasing demand for downsizing the ion exchange device to reduce the amount of regenerated chemicals used and the amount of regenerated waste liquid discharged. Furthermore, in order to reduce the site area of the pure water production apparatus, it is necessary to reduce the size of the ion exchange apparatus and the treatment equipment of the recycled waste liquid to save the space of the apparatus.
【０００３】そこで、これらの要求に対処して、従来、
純水の製造方法として採用されてきた方法、例えば陰陽
両イオン交換樹脂を組み合わせる方法、前段の逆浸透膜
法と後段のイオン交換樹脂法とを組み合わせる法などに
代わって、前段に２段逆浸透膜法を使用することによっ
て、後段のイオン交換装置を不要とするかあるいは小型
化しようとする提案が成されている。Therefore, in order to meet these demands, conventionally,
Instead of the method adopted as a method for producing pure water, for example, a method of combining both anion and cation ion exchange resins, a method of combining the reverse osmosis membrane method of the first step and the ion exchange resin method of the second step, etc. Proposals have been made to eliminate or reduce the size of the ion exchange device in the subsequent stage by using the membrane method.
【０００４】２段逆浸透膜法とは、原水を、順次、第１
逆浸透膜装置及び第２逆浸透膜装置に通水し、これによ
り純度の高い水質の純水を得るようにした方法であっ
て、例えば、第１逆浸透膜装置から流出した全カチオン
が１０ppm 前後の一次透過水を第２逆浸透膜装置に通す
ことにより、全カチオンが１ppm 前後ないしそれ以下の
二次透過水の処理水を得ることができる。The two-stage reverse osmosis membrane method is one in which raw water is sequentially
A method in which water is passed through the reverse osmosis membrane device and the second reverse osmosis membrane device to obtain pure water of high purity, and for example, all cations flowing out from the first reverse osmosis membrane device are 10 ppm. By passing the front and rear primary permeated water through the second reverse osmosis membrane device, it is possible to obtain treated water of the secondary permeated water in which all cations are around 1 ppm or less.
【０００５】ところで、２段逆浸透膜法で純水を製造す
る場合、炭酸は比較的容易に逆浸透膜を透過して、二次
透過水中に残留するので、結果的に得られる純水の水質
が悪くなると言う問題があった。By the way, when pure water is produced by the two-stage reverse osmosis membrane method, carbonic acid permeates the reverse osmosis membrane relatively easily and remains in the secondary permeated water. There was a problem that the water quality would deteriorate.
【０００６】この問題を改善するために、第１逆浸透膜
装置に供給する原水、あるいは第２逆浸透膜装置に給水
する一次透過水にアルカリを添加して水中の炭酸を逆浸
透膜で除去可能な炭酸水素イオンや炭酸イオンに変化さ
せてから逆浸透膜処理する方法が提案されている。例え
ば、特開昭６１−４５９１号公報は、第１逆浸透膜装置
に供給する原水のｐＨを５以下とし、かつ第２逆浸透膜
装置に給水する一次透過水のｐＨを９以上にすることを
提案している。また、特開昭６２−４２７８７号公報
は、２段の逆浸透膜装置の上流に脱炭酸装置を設けて、
脱炭酸装置への給水のｐＨを４．０〜６．０にすること
により原水中の炭酸水素イオン、炭酸イオン等の炭酸系
イオンを遊離の炭酸に変化させて炭酸ガスとして除去し
た後に、第１逆浸透膜装置に通水し、次いで第２逆浸透
膜装置に給水する１次透過水のｐＨを８〜９とすること
を提案している。また、特開平１−２３１９８８号公報
は、２段の逆浸透膜装置の上流に脱炭酸装置を設けて、
脱炭酸装置への給水のｐＨを４．０〜４．５にすること
により原水中の炭酸系イオンを炭酸ガスとして除去した
後に、脱炭酸処理した原水のｐＨを８．０〜８．５とし
て２段の逆浸透膜装置に給水することを提案している。
更には、特開平４−１６２７９号公報は、２段の逆浸透
膜装置に給水する原水のｐＨを８．６±０．２にするこ
とを提案している。In order to solve this problem, alkali is added to the raw water supplied to the first reverse osmosis membrane device or the primary permeate water supplied to the second reverse osmosis membrane device to remove carbon dioxide in the water by the reverse osmosis membrane. There has been proposed a method in which a reverse osmosis membrane treatment is performed after changing the hydrogen carbonate ion or carbonate ion to a possible one. For example, in JP-A-61-4591, the pH of the raw water supplied to the first reverse osmosis membrane device is set to 5 or less, and the pH of the primary permeate water supplied to the second reverse osmosis membrane device is set to 9 or more. Is proposed. Further, JP-A-62-42787 discloses that a decarboxylation device is provided upstream of a two-stage reverse osmosis membrane device,
After the pH of the water supplied to the decarbonator is adjusted to 4.0 to 6.0, the carbonate ions such as hydrogen carbonate ions and carbonate ions in the raw water are converted into free carbon dioxide and removed as carbon dioxide gas. It is proposed that the pH of the primary permeated water, which is passed through the first reverse osmosis membrane device and then supplied to the second reverse osmosis membrane device, be 8-9. Further, Japanese Patent Laid-Open No. 1-231988 discloses that a decarboxylation device is provided upstream of a two-stage reverse osmosis membrane device,
After removing carbonic acid ions in the raw water as carbon dioxide gas by adjusting the pH of the feed water to the decarbonation device to 4.0 to 4.5, the pH of the decarbonated raw water was adjusted to 8.0 to 8.5. It is proposed to supply water to a two-stage reverse osmosis membrane device.
Further, JP-A-4-16279 proposes that the pH of the raw water supplied to the two-stage reverse osmosis membrane device is 8.6 ± 0.2.
【０００７】[0007]
【発明が解決しようとする課題】しかし、上述した従来
の２段逆浸透膜法では、二次透過水、即ち処理水中の炭
酸の残留量は低くなるが、処理水の電気伝導率は必ずし
も低くならないと言う欠点があった。これでは、電気伝
導率の低い純水を必要とする半導体装置の製造工場等か
らの水質要求に相反することになるので、電気伝導率の
低い処理水を得ることができる２段逆浸透膜法の開発が
要望されていた。However, in the conventional two-stage reverse osmosis membrane method described above, the residual amount of carbon dioxide in the secondary permeated water, that is, the treated water is low, but the electric conductivity of the treated water is not always low. There was a drawback that it didn't. This conflicts with the water quality requirement from a semiconductor device manufacturing plant or the like that requires pure water with low electric conductivity, so that the two-stage reverse osmosis membrane method capable of obtaining treated water with low electric conductivity is obtained. Was required to be developed.
【０００８】そこで、本発明の目的は、２段逆浸透膜法
によって原水を処理するに当たり可及的に電気伝導率の
低い処理水を得る方法を提供することである。Therefore, an object of the present invention is to provide a method for obtaining treated water having as low an electric conductivity as possible in treating raw water by the two-stage reverse osmosis membrane method.
【０００９】[0009]
【課題を解決するための手段】本発明者等は、従来の２
段逆浸透膜法では、第１逆浸透膜装置に給水する原水の
ｐＨ、又は第２逆浸透膜装置に給水する一次透過水のｐ
Ｈを８以上に調整しており、そのために比較的多量のア
ルカリ、例えば苛性ソーダを原水又は一次透過水に添加
することが必要になること、その結果、二次透過水、即
ち２段逆浸透膜法で処理した処理水中にｐＨ調整用に添
加したナトリウムイオンなどの金属イオンが比較的多く
残存することになるので、低い電気伝導率の処理水を得
ることができないと推論した。そこで、本発明者等は、
研究の末、２段逆浸透膜法の第１逆浸透膜装置に導入す
る原水のｐＨと二次透過水の電気伝導率との関係につい
て一つの注目すべき事実を種々の実験を通して見い出し
た。次にその実験を説明する。実験例 先ず、本実験で使用した実験装置の概略構成を図２に示
すフローシートを参照して説明する。本実験装置４０
は、原水を脱炭酸処理する脱炭酸塔４２と、脱炭酸処理
した原水を収容する中間タンク４４と、逆浸透膜として
東レ（株）製のＳＵ７２０をそれぞれ使用した第１逆浸
透膜装置４６と、第２逆浸透膜装置４８とから構成さ
れ、更に、脱炭酸塔４２に流入する原水のｐＨを調整す
るために塩酸を注入する注入管が脱炭酸塔４２への給水
管に接続され、また、第１逆浸透膜装置４６への給水の
ｐＨを調整するために中間タンク４４に苛性ソーダ水溶
液を添加する添加管が中間タンク４４に設けてある。Means for Solving the Problems The present inventors have
In the step reverse osmosis membrane method, the pH of the raw water supplied to the first reverse osmosis membrane device or the p of the primary permeate water supplied to the second reverse osmosis membrane device.
Since H is adjusted to 8 or more, it is necessary to add a relatively large amount of alkali, such as caustic soda, to the raw water or the primary permeate, and as a result, the secondary permeate, that is, the two-stage reverse osmosis membrane. It was inferred that treated water having a low electric conductivity could not be obtained because a relatively large amount of metal ions such as sodium ions added for pH adjustment remained in the treated water treated by the method. Therefore, the present inventors
After the research, one remarkable fact was found out through various experiments regarding the relationship between the pH of the raw water introduced into the first reverse osmosis membrane apparatus of the two-stage reverse osmosis membrane method and the electrical conductivity of the secondary permeate. Next, the experiment will be described. Experimental Example First, the schematic configuration of the experimental apparatus used in this experiment will be described with reference to the flow sheet shown in FIG. This experimental device 40
Is a decarbonation tower 42 for decarboxylating raw water, an intermediate tank 44 for containing the decarbonated raw water, and a first reverse osmosis membrane device 46 using SU720 manufactured by Toray Industries, Inc. as a reverse osmosis membrane, respectively. , A second reverse osmosis membrane device 48, and an injection pipe for injecting hydrochloric acid to adjust the pH of the raw water flowing into the decarbonation tower 42 is connected to a water supply pipe to the decarbonation tower 42. The intermediate tank 44 is provided with an addition pipe for adding an aqueous solution of caustic soda to the intermediate tank 44 in order to adjust the pH of the water supplied to the first reverse osmosis membrane device 46.
【００１０】実験に当たっては、新潟県工業用水を除濁
して得た水を原水として使用した。先ず、脱炭酸塔４２
に給水する原水に塩酸水溶液を注入してｐＨを４．５に
調整した後、脱炭酸塔４２にて脱炭酸処理を施し、中間
タンク４４に収容した。次いで、脱炭酸処理した原水を
収容した給水タンク４４に苛性ソーダ水溶液を注入して
第１逆浸透膜装置４６に給水する原水のｐＨを所定の値
に調整した後に第１逆浸透膜装置４６及び第２逆浸透膜
装置４８に順次通水し、第２逆浸透膜装置４８から流出
する二次透過水の電気伝導率を測定した。実験では、第
１逆浸透膜装置４６に給水する原水のｐＨを５．５から
８．５の範囲で変化させ、そのｐＨの原水に対応する二
次透過水の電気伝導率を測定し、その測定結果を原水の
ｐＨと対比させて図３に示した。In the experiment, water obtained by suspending Niigata industrial water was used as raw water. First, decarbonation tower 42
An aqueous hydrochloric acid solution was injected into the raw water to be supplied to the above to adjust the pH to 4.5, and then the carbon dioxide was subjected to a decarbonation treatment in the decarbonation tower 42 and stored in the intermediate tank 44. Next, after the caustic soda aqueous solution is injected into the water supply tank 44 containing the decarbonated raw water to adjust the pH of the raw water to be supplied to the first reverse osmosis membrane device 46 to a predetermined value, the first reverse osmosis membrane device 46 and the first reverse osmosis membrane device 46 Water was sequentially passed through the second reverse osmosis membrane device 48, and the electrical conductivity of the secondary permeated water flowing out from the second reverse osmosis membrane device 48 was measured. In the experiment, the pH of the raw water supplied to the first reverse osmosis membrane device 46 was changed in the range of 5.5 to 8.5, and the electric conductivity of the secondary permeated water corresponding to the raw water of that pH was measured. The measurement results are shown in FIG. 3 in comparison with the pH of the raw water.
【００１１】図３に示した結果から判るとおり、二次透
過水の電気伝導率は、第１逆浸透膜装置４６に給水する
原水のｐＨが７．２及び７．８の点で臨界的に低下し、
７．２及び７．８の間では０．５μＳ／ｃｍ以下であっ
た。特に、第１逆浸透膜装置４６に給水する原水のｐＨ
が７．６〜７．７付近では極小値を示し、二次透過水の
電気伝導率は、最低値の０．２μＳ／ｃｍ程度を示し
た。As can be seen from the results shown in FIG. 3, the electric conductivity of the secondary permeated water is critical when the pH of the raw water supplied to the first reverse osmosis membrane device 46 is 7.2 and 7.8. Drop,
It was 0.5 μS / cm or less between 7.2 and 7.8. Particularly, the pH of the raw water supplied to the first reverse osmosis membrane device 46
Shows a minimum value in the vicinity of 7.6 to 7.7, and the electric conductivity of the secondary permeated water shows a minimum value of about 0.2 μS / cm.
【００１２】以上の知見に基づいて、上記目的を達成す
るために、本発明に係る２段逆浸透膜法は、逆浸透膜法
により原水から一次透過水を得る第１次逆浸透膜工程
と、逆浸透膜法により一次透過水から二次透過水を処理
水として得る第２次逆浸透膜工程とを備える２段式逆浸
透膜処理方法において、原水のｐＨを７．２から７．８
の範囲に調整して、第１次逆浸透膜工程に給水すること
を特徴としている。Based on the above findings, in order to achieve the above object, the two-stage reverse osmosis membrane method according to the present invention comprises a first reverse osmosis membrane step for obtaining primary permeated water from raw water by the reverse osmosis membrane method. In the two-stage reverse osmosis membrane treatment method, which comprises a secondary reverse osmosis membrane step of obtaining secondary permeate as treated water from primary permeate by the reverse osmosis membrane method, the pH of the raw water is from 7.2 to 7.8.
It is characterized in that the water is supplied to the first reverse osmosis membrane process after being adjusted to the above range.
【００１３】また、原水中の炭酸系イオンの除去には脱
炭酸工程を設けることが有効であり、その際には、本発
明に係る２段逆浸透膜法は、原水を脱炭酸処理する脱炭
酸工程と、脱炭酸処理した原水から逆浸透膜法により一
次透過水を得る第１次逆浸透膜工程と、一次透過水から
逆浸透膜法により二次透過水を処理水として得る第２次
逆浸透膜工程とを備える２段式逆浸透膜処理方法におい
て、脱炭酸処理した原水のｐＨを７．２から７．８の範
囲に調整して、第１次逆浸透膜工程に給水することを特
徴としている。Further, it is effective to provide a decarboxylation step for removing carbonate ions in the raw water. At that time, in the two-stage reverse osmosis membrane method according to the present invention, the decarbonation treatment of the raw water is performed. Carbonation step, primary reverse osmosis membrane step from reverse osmosis membrane method from decarbonated raw water, and secondary reverse osmosis membrane step from primary permeate water to reverse osmosis membrane method In a two-stage reverse osmosis membrane treatment method comprising a reverse osmosis membrane step, the pH of the decarbonated raw water is adjusted to a range of 7.2 to 7.8, and water is supplied to the first reverse osmosis membrane step. Is characterized by.
【００１４】本発明方法は、電気伝導率の低い純水を必
要とする発電所向けや半導体装置の製造工場向けの純水
製造方法として最適であり、また本発明方法をイオン交
換法と組み合わせることにより、電気伝導率が低く、か
つナトリウムイオン等のイオン濃度の極めて低い純水を
製造することができる。The method of the present invention is most suitable as a method for producing pure water for a power plant or a semiconductor device manufacturing plant that requires pure water having a low electric conductivity, and the method of the present invention is combined with an ion exchange method. Thus, pure water having a low electric conductivity and an extremely low concentration of ions such as sodium ions can be produced.
【００１５】[0015]
【発明の実施の形態】以下に、添付図面を参照して、本
発明の実施の形態を具体的かつ詳細に説明する。図１は
本発明に係る２段逆浸透膜法を実施する装置の一例の構
成を示すフローシートである。本例の水処理装置１０
は、高速繊維濾過装置１２と膜濾過装置１４とからなる
除濁装置と、脱炭酸塔１６と、脱炭酸処理した原水を収
容する中間タンク１８と、第１逆浸透膜装置２０と、第
２逆浸透膜装置２２とを備えている。更に、脱炭酸塔１
６に流入する原水のｐＨを調整するための第１薬剤注入
設備と、中間タンク１８に薬剤を投入して第１逆浸透膜
装置２０への給水のｐＨを調整するための第２薬剤注入
設備とが設けてある。Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a flow sheet showing the configuration of an example of an apparatus for carrying out the two-stage reverse osmosis membrane method according to the present invention. Water treatment device 10 of this example
Is a decontamination device comprising a high-speed fiber filtration device 12 and a membrane filtration device 14, a decarbonation tower 16, an intermediate tank 18 for containing decarbonated raw water, a first reverse osmosis membrane device 20, and a second The reverse osmosis membrane device 22 is provided. Furthermore, decarbonation tower 1
First chemical injection equipment for adjusting the pH of raw water flowing into No. 6 and second chemical injection equipment for adjusting the pH of the feed water to the first reverse osmosis membrane device 20 by introducing the chemical into the intermediate tank 18. And are provided.
【００１６】第１薬剤注入設備は第１薬剤槽２４と第１
薬剤ポンプ２６とｐＨ計２８とを備えており、第２薬剤
注入設備は第２薬剤槽３０と第２薬剤ポンプ３２とｐＨ
計３４とｐＨ計３４の測定値に基づいて第２薬剤ポンプ
３２を回転数制御して薬剤注入量を制御する制御装置３
６とを備えている。第２薬剤ポンプ３２の回転数制御に
代えて、流量調節弁を第２薬剤ポンプ３２の吐出管に設
け、流量調節弁の開度を調節することにより薬剤注入量
を制御しても良い。尚、原水を通水するためのポンプ等
は、簡単にするために図示していない。The first medicine injecting facility is composed of a first medicine tank 24 and a first medicine tank 24.
It is equipped with a drug pump 26 and a pH meter 28, and the second drug injecting facility is provided with a second drug tank 30, a second drug pump 32, and a pH.
A control device 3 for controlling the number of revolutions of the second medicine pump 32 based on the measured values of the total meter 34 and the pH meter 34 to control the medicine injection amount.
6 is provided. Instead of controlling the rotation speed of the second drug pump 32, a flow rate control valve may be provided in the discharge pipe of the second drug pump 32, and the drug injection amount may be controlled by adjusting the opening of the flow rate control valve. A pump for passing raw water is not shown for simplicity.
【００１７】高速繊維濾過装置１２は、いわゆる高速流
式の繊維濾過装置であって、繊維素の間に懸濁物を捕捉
できるように、多数の繊維素を集合させた繊維束や繊維
塊等の懸濁物捕捉用の担体を容器内に多数内蔵させて構
成した濾過装置である。繊維素の濾材には、例えば太さ
が１０μm 〜８０μm 程度、長さが数十cm〜数ｍのアク
リル繊維、ポリエステル繊維、ポリアミド繊維等の非燃
単繊維を多数（例えば、数十〜数百本）束ねた長繊維束
を多数使用する。そのような長繊維束の下端を容器内部
の下部に設けられた目板に固定し、長繊維束の各上端を
容器上方に伸ばして自由端にした箒状の濾材になってい
る。このような長繊維束の濾材を有する濾過装置に下降
流で原水を通すことにより、懸濁物を効率良く捕捉する
ことができる。The high-speed fiber filtering device 12 is a so-called high-speed flow type fiber filtering device, and is a fiber bundle or a fiber lump in which a large number of fibrous materials are collected so that a suspended matter can be captured between the fibrous materials. The filtration device is configured by incorporating a large number of carriers for capturing the suspended solids in a container. As the fibrous filter medium, for example, a large number of non-combustible single fibers such as acrylic fibers, polyester fibers, polyamide fibers having a thickness of about 10 μm to 80 μm and a length of several tens cm to several m (for example, several tens to several hundreds). Use a large number of bundled long fiber bundles. The lower end of such a long fiber bundle is fixed to a perforated plate provided at the lower part inside the container, and each upper end of the long fiber bundle is extended upward of the container to form a free end broom-shaped filter medium. The suspension can be efficiently captured by passing the raw water in a descending flow through a filtration device having such a filter material having a long fiber bundle.
【００１８】膜濾過装置１４は、その仕様に関し特に限
定されるものではなく、膜としては、セラミック等の無
機膜、又は酢酸セルロース系、ポリスルホン系、ポリプ
ロピレン系、ポリエチレン系、ポリアクリロニトリル系
など高分子化合物からなる有機膜等をチューブ状、プリ
ーツ状、中空糸状、スパイラル状、平膜状にしたものを
使用できる。本例では、旭化成工業（株）製のＬＮＶ−
５０１０（商品名）の限外濾過膜（ＵＦ）を用いたクロ
スフロー式の膜濾過装置で構成されている。また、大流
量の原水を膜濾過する場合には、中空糸膜を数百〜数千
本束ねてケースに入れたモジュール式の膜濾過装置を使
用することもできる。尚、膜濾過装置１４は、全量濾過
式でも良く、また精密濾過膜（ＭＦ）を使用しても良
い。The membrane filtering device 14 is not particularly limited in terms of its specifications, and as the membrane, an inorganic membrane such as ceramics, or a polymer such as cellulose acetate, polysulfone, polypropylene, polyethylene or polyacrylonitrile is used. An organic film or the like made of a compound may be used in the form of a tube, a pleat, a hollow fiber, a spiral, or a flat film. In this example, Asahi Kasei Corporation's LNV-
It is composed of a cross-flow type membrane filtration device using an ultrafiltration membrane (UF) of 5010 (trade name). Further, in the case of performing membrane filtration of a large amount of raw water, a modular membrane filtration device in which hundreds to thousands of hollow fiber membranes are bundled and placed in a case can be used. The membrane filtration device 14 may be a total filtration type or a microfiltration membrane (MF).
【００１９】脱炭酸塔１６は、既知の脱炭酸塔であっ
て、例えばラシヒリング等の気液接触用充填材を充填し
た充填層１６ａを有する塔で構成され、塔の上部から原
水を流下させ、塔下部から空気を導入して充填層内で気
液接触させ、原水中の炭酸を炭酸ガスとしてを除去す
る。また、塔の上部から真空ポンプ等でガスを吸引す
る、いわゆる真空式脱気塔でも良い。これにより、炭酸
水素イオン、炭酸イオン等の炭酸系イオンを炭酸ガスと
して原水から除去することができるので、第２逆浸透膜
装置２２から流出する二次透過水の炭酸系イオン濃度が
低くなる。The decarbonation tower 16 is a known decarbonation tower, and is composed of a tower having a packed bed 16a filled with a filler for gas-liquid contact such as Raschig ring, and raw water is flowed down from the upper part of the tower. Air is introduced from the lower part of the tower to make gas-liquid contact in the packed bed, and carbon dioxide in the raw water is removed as carbon dioxide gas. Further, a so-called vacuum type degassing tower in which gas is sucked from the upper part of the tower by a vacuum pump or the like may be used. As a result, carbonic acid ions such as hydrogencarbonate ions and carbonic acid ions can be removed from the raw water as carbon dioxide gas, so the carbonic acid ion concentration of the secondary permeate water flowing out from the second reverse osmosis membrane device 22 becomes low.
【００２０】第１逆浸透膜装置２０及び第２逆浸透膜装
置２２では、ポリアミド系樹脂や酢酸セルロース系、ポ
リスルホン系、ポリプロピレン系、ポリエチレン系、ポ
リアクリロニトリル系など高分子化合物からなる有機膜
等をチューブ状、プリーツ状、中空糸状、スパイラル
状、平膜状にしたものを使用できる。本例では、東レ
（株）製のＳＵ７２０を逆浸透膜として使用している。In the first reverse osmosis membrane device 20 and the second reverse osmosis membrane device 22, an organic film made of a polymer compound such as polyamide resin, cellulose acetate, polysulfone, polypropylene, polyethylene or polyacrylonitrile is used. Tubes, pleats, hollow fibers, spirals, and flat membranes can be used. In the present example, SU720 manufactured by Toray Industries, Inc. is used as the reverse osmosis membrane.
【００２１】以下に、図１を参照して、上述の水処理装
置を使用した本発明方法の実施を説明する。まず、原水
を高速繊維濾過装置１２に、次いで膜濾過装置１４に通
水し、除濁する。次いで、第１薬剤注入設備により塩酸
水溶液を除濁原水に注入し、ｐＨを４．０から４．５の
範囲に調整して原水中の炭酸系イオンを遊離の炭酸に変
化させる。次いで、ｐＨ調整した除濁原水を脱炭酸塔１
６の上部から流下させて充填層１６ａ内で塔下部から導
入した空気と気液接触させて原水中の炭酸を炭酸ガスと
して除去する。除去された炭酸ガスは、塔上部から排出
される。The implementation of the method of the present invention using the above-mentioned water treatment device will be described below with reference to FIG. First, raw water is passed through the high-speed fiber filtration device 12 and then through the membrane filtration device 14 to remove turbidity. Then, a hydrochloric acid aqueous solution is injected into the turbid raw water by the first chemical injection facility, and the pH is adjusted to a range of 4.0 to 4.5 to change the carbonate ion in the raw water into free carbonic acid. Next, the pH-adjusted turbid raw water is decarbonated in the tower 1.
6 is flowed down from the upper part of 6 to make gas-liquid contact with the air introduced from the lower part of the tower in the packed bed 16a to remove carbonic acid in the raw water as carbon dioxide gas. The removed carbon dioxide gas is discharged from the upper part of the tower.
【００２２】脱炭酸処理された原水は、炭酸系イオン濃
度の低い水質となって中間タンク１８に流入し、一時的
に滞留すると共にそこでｐＨが７．２から７．８の範囲
になるように調整され、これにより、脱炭酸処理後の原
水中に残留する少量の炭酸が逆浸透膜で除去可能な炭酸
水素イオン及び／又は炭酸イオンに変化させることがで
きる。ｐＨ調整は、第２薬剤注入設備によりアルカリ溶
液、例えば苛性ソーダ水溶液を中間タンク１８に添加す
ることより行われる。ｐＨ調整された原水は、第１逆浸
透膜装置２０及び第２逆浸透膜装置２２を経て二次透過
水として流出する。二次透過水は、炭酸濃度及び電気伝
導率の低い良好な水質の純水であって、本水処理装置１
０の処理水として系外に送水される。一方、第１逆浸透
膜装置２０の濃縮液は、一部系外に排出され、残りは中
間タンク１８に戻され、また第２逆浸透膜装置２２の濃
縮液はその全量が中間タンク１８に戻されて、再度第１
及び第２逆浸透膜装置２０、２２に給水される。The decarbonated raw water becomes a water quality having a low concentration of carbonate ions, flows into the intermediate tank 18, and is temporarily retained therein so that the pH thereof is in the range of 7.2 to 7.8. The amount of carbonic acid is adjusted so that a small amount of carbonic acid remaining in the raw water after the decarboxylation treatment can be converted into hydrogen carbonate ions and / or carbonate ions that can be removed by the reverse osmosis membrane. The pH is adjusted by adding an alkaline solution, for example, a caustic soda aqueous solution, to the intermediate tank 18 by the second chemical injection facility. The pH-adjusted raw water flows out as secondary permeated water through the first reverse osmosis membrane device 20 and the second reverse osmosis membrane device 22. The secondary permeated water is pure water of good water quality with low carbon dioxide concentration and electric conductivity, and
It is sent out of the system as treated water of 0. On the other hand, the concentrated liquid of the first reverse osmosis membrane device 20 is partially discharged to the outside of the system and the rest is returned to the intermediate tank 18, and the entire concentrated liquid of the second reverse osmosis membrane device 22 is stored in the intermediate tank 18. Returned to the first place again
Also, water is supplied to the second reverse osmosis membrane devices 20 and 22.
【００２３】上述の水処理装置１０を使用することによ
り、本発明方法に従って炭酸濃度及び電気伝導率の低い
純水を容易に製造することができる。尚、上述の水処理
装置１０は本発明方法を実施する装置の一例であって、
例えば除濁装置を別の形式の装置に代え、或いは炭酸系
イオン濃度やカルシウム、マグネシウム等の硬度成分の
極めて低い原水の場合には、脱炭酸塔を省略することも
できる。また、本発明方法とイオン交換法とを組み合わ
せて、二次透過水をイオン交換装置に通水することによ
り、発電所のボイラ用補給水として、或いは半導体装置
の製造工場その他の産業で使用する超純水の原水として
最適な純水を製造することができる。By using the above-mentioned water treatment device 10, pure water having a low carbon dioxide concentration and a low electric conductivity can be easily produced according to the method of the present invention. The above-mentioned water treatment device 10 is an example of a device for carrying out the method of the present invention,
For example, in the case where the turbidity removing device is replaced with another device, or in the case of raw water having extremely low carbonate ion concentration and hardness components such as calcium and magnesium, the decarbonation tower may be omitted. In addition, by combining the method of the present invention and the ion exchange method, the secondary permeated water is passed through the ion exchange device to be used as make-up water for a boiler of a power plant or in a semiconductor device manufacturing factory or other industries. It is possible to produce pure water that is optimal as raw water for ultrapure water.
【００２４】[0024]
【発明の効果】本発明方法によれば、第１次及び第２次
逆浸透膜工程を備えた２段式逆浸透膜処理方法におい
て、２段の逆浸透膜装置に給水する原水のｐＨを７．２
から７．８に調整して、第１次逆浸透膜工程に送水する
ことにより、電気伝導率の低い純水を製造することがで
きる。本発明方法により得た純水は、半導体装置の製造
工場等で必要とする電気伝導率の低い超純水を製造する
ための原水として最適である。According to the method of the present invention, in the two-stage reverse osmosis membrane treatment method including the first and second reverse osmosis membrane steps, the pH of the raw water supplied to the two-stage reverse osmosis membrane device is adjusted. 7.2
To 7.8 and feed water to the first reverse osmosis membrane step, whereby pure water having low electric conductivity can be produced. The pure water obtained by the method of the present invention is optimal as raw water for producing ultrapure water having a low electric conductivity, which is required in a semiconductor device manufacturing factory or the like.
【図１】本発明方法を実施する水処理装置の構成を示す
フローシートである。FIG. 1 is a flow sheet showing the configuration of a water treatment device for carrying out the method of the present invention.
【図２】実験装置の構成を示すフローシートである。FIG. 2 is a flow sheet showing the configuration of an experimental device.
【図３】実験結果を示すグラフである。FIG. 3 is a graph showing experimental results.
１０ 水処理装置 １２ 高速繊維濾過装置 １４ 膜濾過装置 １６ 脱炭酸塔 １８ 中間タンク ２０ 第１逆浸透膜装置 ２２ 第２逆浸透膜装置 ２４ 第１薬剤槽 ２６ 第１薬剤ポンプ ２８ ｐＨ計 ３０ 第２薬剤槽 ３２ 第２薬剤ポンプ ３４ ｐＨ計 ３６ 制御装置 10 Water Treatment Device 12 High-speed Fiber Filtration Device 14 Membrane Filtration Device 16 Decarbonation Tower 18 Intermediate Tank 20 First Reverse Osmosis Membrane Device 22 Second Reverse Osmosis Membrane Device 24 First Chemical Tank 26 First Chemical Pump 28 pH Meter 30 Second Drug tank 32 Second drug pump 34 pH meter 36 Control device
Claims (2)
得る第１次逆浸透膜工程と、逆浸透膜法により一次透過
水から二次透過水を処理水として得る第２次逆浸透膜工
程とを備える２段式逆浸透膜処理方法において、 原水のｐＨを７．２から７．８の範囲に調整して、第１
次逆浸透膜工程に給水することを特徴とする２段式逆浸
透膜処理方法。1. A primary reverse osmosis membrane process for obtaining primary permeated water from raw water by a reverse osmosis membrane method, and a secondary reverse osmosis membrane for obtaining secondary permeated water from primary permeated water as a treated water by a reverse osmosis membrane method. In the two-stage reverse osmosis membrane treatment method including the steps, the pH of the raw water is adjusted to the range of 7.2 to 7.8, and the first
A two-stage reverse osmosis membrane treatment method characterized by supplying water to the next reverse osmosis membrane step.
炭酸処理した原水から逆浸透膜法により一次透過水を得
る第１次逆浸透膜工程と、一次透過水から逆浸透膜法に
より二次透過水を処理水として得る第２次逆浸透膜工程
とを備える２段式逆浸透膜処理方法において、 脱炭酸処理した原水のｐＨを７．２から７．８の範囲に
調整して、第１次逆浸透膜工程に給水することを特徴と
する２段式逆浸透膜処理方法。2. A decarboxylation step of decarboxylating raw water, a first reverse osmosis membrane step of obtaining primary permeate from the decarbonated raw water by a reverse osmosis membrane method, and a reverse osmosis membrane method from the primary permeate In a two-stage reverse osmosis membrane treatment method comprising a secondary reverse osmosis membrane step of obtaining secondary permeated water as treated water, the pH of the decarbonated raw water is adjusted to a range of 7.2 to 7.8. , A two-stage reverse osmosis membrane treatment method, which comprises supplying water to the first reverse osmosis membrane step.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24543495A JPH0957261A (en) | 1995-08-30 | 1995-08-30 | Two-stage type reverse osmosis membrane treatment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24543495A JPH0957261A (en) | 1995-08-30 | 1995-08-30 | Two-stage type reverse osmosis membrane treatment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0957261A true JPH0957261A (en) | 1997-03-04 |
Family
ID=17133608
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24543495A Pending JPH0957261A (en) | 1995-08-30 | 1995-08-30 | Two-stage type reverse osmosis membrane treatment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0957261A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999050184A1 (en) * | 1998-03-31 | 1999-10-07 | United States Filter Corporation | Water treatment system and process comprising ph-adjustment |
| JP2003024715A (en) * | 2001-07-19 | 2003-01-28 | Nippon Rensui Co Ltd | Filter apparatus |
| JP2007268352A (en) * | 2006-03-30 | 2007-10-18 | Matsushita Electric Ind Co Ltd | Water treatment method and water treatment apparatus |
| CN104370320A (en) * | 2013-08-18 | 2015-02-25 | 四川锦美环保科技有限公司 | Device and device for realizing purging decarburization |
| US9073763B2 (en) | 1996-08-12 | 2015-07-07 | Debasish Mukhopadhyay | Method for high efficiency reverse osmosis operation |
| JP6269866B1 (en) * | 2017-01-30 | 2018-01-31 | 栗田工業株式会社 | PH control method by electric conductivity |
| CN109502846A (en) * | 2018-11-20 | 2019-03-22 | 江苏中电创新环境科技有限公司 | A kind of decarbonizing tower and decarbonization method |
-
1995
- 1995-08-30 JP JP24543495A patent/JPH0957261A/en active Pending
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9073763B2 (en) | 1996-08-12 | 2015-07-07 | Debasish Mukhopadhyay | Method for high efficiency reverse osmosis operation |
| US9428412B2 (en) | 1996-08-12 | 2016-08-30 | Debasish Mukhopadhyay | Method for high efficiency reverse osmosis operation |
| US6398965B1 (en) | 1998-03-31 | 2002-06-04 | United States Filter Corporation | Water treatment system and process |
| WO1999050184A1 (en) * | 1998-03-31 | 1999-10-07 | United States Filter Corporation | Water treatment system and process comprising ph-adjustment |
| JP2003024715A (en) * | 2001-07-19 | 2003-01-28 | Nippon Rensui Co Ltd | Filter apparatus |
| JP4649791B2 (en) * | 2001-07-19 | 2011-03-16 | 日本錬水株式会社 | Filtration device |
| JP2007268352A (en) * | 2006-03-30 | 2007-10-18 | Matsushita Electric Ind Co Ltd | Water treatment method and water treatment apparatus |
| CN104370320A (en) * | 2013-08-18 | 2015-02-25 | 四川锦美环保科技有限公司 | Device and device for realizing purging decarburization |
| JP6269866B1 (en) * | 2017-01-30 | 2018-01-31 | 栗田工業株式会社 | PH control method by electric conductivity |
| WO2018138957A1 (en) * | 2017-01-30 | 2018-08-02 | 栗田工業株式会社 | Method for controlling ph by electrical conductivity |
| JP2018122210A (en) * | 2017-01-30 | 2018-08-09 | 栗田工業株式会社 | pH VALUE CONTROL METHOD BY ELECTRIC CONDUCTIVITY |
| CN110177764A (en) * | 2017-01-30 | 2019-08-27 | 栗田工业株式会社 | PH control method based on conductivity |
| US11130688B2 (en) | 2017-01-30 | 2021-09-28 | Kurita Water Industries Ltd. | Method for controlling pH by electrical conductivity |
| CN109502846A (en) * | 2018-11-20 | 2019-03-22 | 江苏中电创新环境科技有限公司 | A kind of decarbonizing tower and decarbonization method |
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