JP3194684B2 - Natural water membrane purification method - Google Patents

Natural water membrane purification method

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Publication number
JP3194684B2
JP3194684B2 JP03174795A JP3174795A JP3194684B2 JP 3194684 B2 JP3194684 B2 JP 3194684B2 JP 03174795 A JP03174795 A JP 03174795A JP 3174795 A JP3174795 A JP 3174795A JP 3194684 B2 JP3194684 B2 JP 3194684B2
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JP
Japan
Prior art keywords
backwashing
water
filtration
membrane module
hollow fiber
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.)
Expired - Lifetime
Application number
JP03174795A
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Japanese (ja)
Other versions
JPH08197053A (en
Inventor
修志 中塚
智暢 阿瀬
Original Assignee
ダイセル化学工業株式会社
ダイセン・メンブレン・システムズ株式会社
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Priority to JP03174795A priority Critical patent/JP3194684B2/en
Publication of JPH08197053A publication Critical patent/JPH08197053A/en
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Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【0001】[0001]
【産業上の利用分野】本発明は、中空糸型の濾過膜モジ
ュールを用いた天然水の膜浄化方法に関し、更に詳しく
は水浄化システムにおける中空糸型の濾過膜モジュール
の処理能力を回復させながら行う天然水の膜浄化方法に
関し、特に逆洗洗浄の操作性、効率がよく、しかも中空
糸型の濾過膜モジュールへの負荷が少ない膜洗浄を伴う
天然水の膜浄化方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying natural water using a hollow fiber type filtration membrane module, and more particularly to a method for recovering the processing capacity of a hollow fiber type filtration membrane module in a water purification system. More particularly, the present invention relates to a method for purifying natural water with high operability and efficiency in backwashing, and with a small load on a hollow fiber type filtration membrane module.
【0002】[0002]
【従来の技術】最近、膜分離技術を適用する水浄化シス
テムは、従来の凝集−沈澱−砂濾過−塩素滅菌工程を経
る方法に代わる新たな技術として注目されている。例え
ば、分離膜を用いた水浄化システムとしてはクロスフロ
ー濾過が広く試行されている。ここにクロスフロー濾過
とは、分離膜の一方の膜面(原水供給側分離膜面)に原
水を供給し、分離膜を透過した透過水を分離膜の他方の
膜面(透過水側分離膜面)から回収する際、原水供給側
分離膜面に平行に原水を流して濾過を行うことにより、
分離膜表面に付着した原水に含まれていた濁質物質をそ
の膜表面からはぎ取る効果を有する濾過方法をいう。し
かし、クロスフロー濾過によっても、濾過時間の経過に
よって原水に含まれる濁質物質が分離膜表面に積層し
て、分離膜の目詰まりを生ずる。
2. Description of the Related Art Recently, a water purification system to which a membrane separation technique is applied has been attracting attention as a new technique which replaces a conventional method involving a coagulation-precipitation-sand filtration-chlorine sterilization process. For example, as a water purification system using a separation membrane, cross-flow filtration has been widely tried. Here, the cross-flow filtration means that raw water is supplied to one membrane surface of the separation membrane (raw water supply side separation membrane surface), and the permeated water that has passed through the separation membrane is separated into the other membrane surface of the separation membrane (permeated water side separation membrane). Surface), the raw water flows in parallel to the raw water supply-side separation membrane surface and is filtered.
It refers to a filtration method that has an effect of stripping turbid substances contained in raw water attached to the surface of a separation membrane from the surface of the membrane. However, even in the cross-flow filtration, the turbid substances contained in the raw water are stacked on the surface of the separation membrane with the passage of the filtration time, and the separation membrane is clogged.
【0003】この目詰まりは水浄化システムの運転中断
の原因となるため、この目詰まりを解消あるいは予防す
るために、一般に逆流洗浄(以下、「逆洗」と称す。)
が行われている。分離膜の長期使用を可能とするため、
原水濁度、透過水量、透過水圧等の各種変化量等に基づ
いて逆洗頻度、逆洗時間等を変化させる方法等が提案さ
れている。例えばクロスフロー濾過における逆洗として
は、原水濁度に依存した定期的な逆洗が水道協会雑誌
(Vol.61,No.11,19−26,1992)
に記載され、特開平4−247226号公報には、水質
と濾過量の変動により濾過量低下傾向時に膜の逆洗条件
を変更させる方法が開示され、特開平5−317660
号公報には、原水濁度の変動に応じて逆洗の頻度を調節
し、分離膜を閉鎖させる危険を排除し、かつ用水の回収
率を高めることができる方法が開示されている。
[0003] Since the clogging causes an interruption of the operation of the water purification system, in order to eliminate or prevent the clogging, backwashing is generally performed (hereinafter referred to as "backwashing").
Has been done. To enable long-term use of the separation membrane,
A method has been proposed in which the frequency of backwashing, the time of backwashing, and the like are changed based on various changes in raw water turbidity, permeated water amount, permeated water pressure, and the like. For example, as backwashing in cross-flow filtration, periodic backwashing depending on raw water turbidity is performed by a magazine of the Japan Water Works Association (Vol. 61, No. 11, 19-26, 1992).
Japanese Patent Application Laid-Open No. 4-247226 discloses a method for changing the backwashing conditions of a membrane when the filtration amount tends to decrease due to fluctuations in water quality and filtration amount.
The publication discloses a method in which the frequency of backwashing is adjusted according to the fluctuation of raw water turbidity, the danger of closing the separation membrane is eliminated, and the recovery rate of water can be increased.
【0004】[0004]
【発明が解決しようとする課題】しかしこれらの方法に
よれば、原水側分離膜面に濁質物質が付着した場合に
は、その目詰まりによって原水供給側の原水圧が上昇す
るため、その上昇した圧力の数倍の圧力を逆洗圧として
用い、濁質物質の剥離を実施しようとするものである。
従って、分離膜には常に高圧が負荷されることとなり、
分離膜の耐用年数が短縮される恐れがある。しかも、高
圧負荷は分離膜のみならず、使用されるポンプにも及
ぶ。従って、逆洗効率の向上、ならびに高価な分離膜モ
ジュールの使用条件を緩和し、かつ、各種水浄化システ
ムに容易に対応できる逆洗方法の開発が熱望されてい
る。
However, according to these methods, when a turbid substance adheres to the raw water side separation membrane surface, the raw water pressure on the raw water supply side rises due to clogging, so that the rising A pressure several times higher than the above pressure is used as the backwash pressure to remove the suspended substance.
Therefore, a high pressure is always applied to the separation membrane,
The service life of the separation membrane may be shortened. Moreover, the high pressure load extends not only to the separation membrane but also to the pump used. Therefore, there is a strong demand for improvement of the backwashing efficiency, development of a backwashing method capable of relaxing the use conditions of the expensive separation membrane module and easily coping with various water purification systems.
【0005】[0005]
【課題を解決するための手段】本発明者は上記現状に鑑
み、水浄化システムならびに逆洗について詳細に検討し
た結果、逆洗前に休止過程を設ければ逆洗効率が向上す
ることを見いだし、本発明を完成するに至った。
Means for Solving the Problems In view of the above situation, the present inventor has studied the water purification system and backwashing in detail, and has found that if a pause process is provided before the backwashing, the backwashing efficiency is improved. Thus, the present invention has been completed.
【0006】すなわち本発明は、中空糸型の限外または
精密濾過膜モジュールを用いて天然水を濾過しながら、
中空糸型の濾過膜モジュールを該濾過膜モジュールから
の透過水または別途供給される清浄水により圧力制御ま
たはあらかじめ定められた周期で所定圧力範囲で間欠的
な逆洗を行う天然水の膜浄化方法において、前記逆洗の
前に濾過膜モジュールに原水を供給するための原水供
給ポンプを所定時間停止する濾過処理の休止過程(但
し、この休止過程において次亜塩素酸ナトリウム溶液に
濾過膜モジュールを接触させる場合を除く)を設けるこ
とを特徴とする天然水の膜浄化方法を提供するものであ
る。また、濾過処理の休止過程が30秒〜15分である
ことを特徴とする前記天然水の膜浄化方法を提供するも
のである。また本発明は、前記中空糸型の限外または精
密濾過膜モジュールが酢酸セルロース製濾過膜モジュー
ルであることを特徴とする前記天然水の膜浄化方法を提
供するものである。さらに、中空糸型の限外または精密
濾過膜モジュールを用いて天然水を濾過しながら、中空
糸型の濾過膜モジュールを該濾過膜モジュールからの透
過水または別途供給される清浄水により圧力制御または
あらかじめ定められた周期で所定圧力範囲で間欠的な逆
洗を行う天然水の膜浄化方法において、濾過膜モジュー
ルの目詰まりによる処理能力低下に応じて、殺菌剤を含
む逆洗水による逆洗操作、逆洗および濾過処理の休止
操作、逆洗操作の連続した三操作からなる休止付き
逆洗過程を設けることを特徴とする天然水の膜浄化方法
を提供するものである。また、中空糸型の限外または精
密濾過膜モジュールを用いて天然水を濾過しながら、中
空糸型の濾過膜モジュールを該濾過膜モジュールからの
透過水または別途供給される清浄水により圧力制御また
はあらかじめ定められた周期で所定圧力範囲で間欠的な
逆洗を行う天然水の膜浄化方法において、前記逆洗の直
前に濾過処理の休止過程を設けた天然水の膜浄化を行い
ながら、濾過膜モジュールの目詰まりによる処理能力低
下に応じて、殺菌剤を含む逆洗水による逆洗操作、逆
洗および濾過処理の休止操作、逆洗操作の連続した
三操作からなる休止付き逆洗過程を設けることを特徴と
する天然水の膜浄化方法を提供するものである。加え
て、逆洗および濾過処理の休止操作が1〜10時間で
あることを特徴とする前記天然水の膜浄化方法を提供す
るものである。
That is, the present invention provides a method of filtering natural water using a hollow fiber type ultra or microfiltration membrane module.
A method for purifying natural water by performing pressure control or intermittent backwashing of a hollow fiber type filtration membrane module with permeated water from the filtration membrane module or separately supplied clean water in a predetermined pressure range at a predetermined cycle. in raw water supply for supplying raw water to the filtration membrane module <br/> immediately preceding the backwash
Pause process of filtration process in which feed pump is stopped for a predetermined time (however,
Then, during this resting process, the sodium hypochlorite solution
(Excluding the case where the filtration membrane module is brought into contact with the filtration membrane module) . The present invention also provides the method for purifying a membrane of natural water, wherein the suspension process of the filtration treatment is performed for 30 seconds to 15 minutes. The present invention also provides the method for purifying a natural water membrane, wherein the hollow fiber type ultra or microfiltration membrane module is a cellulose acetate filtration membrane module. Further, while filtering natural water using a hollow fiber type ultra or microfiltration membrane module, the hollow fiber type filtration membrane module is pressure-controlled or controlled by permeated water from the filtration membrane module or separately supplied clean water. In a natural water membrane purification method in which intermittent backwashing is performed in a predetermined pressure range at a predetermined cycle, a backwashing operation using backwashing water containing a disinfectant according to a reduction in processing capacity due to clogging of a filtration membrane module. The present invention also provides a method for purifying natural water membranes, characterized by providing a backwashing step with a pause consisting of three consecutive operations of backwashing and filtration, and backwashing. In addition, while filtering natural water using a hollow fiber type ultra or microfiltration membrane module, the hollow fiber type filtration membrane module is pressure-controlled or controlled by permeated water from the filtration membrane module or separately supplied clean water. In a method for purifying natural water that performs intermittent backwashing in a predetermined pressure range at a predetermined cycle, a membrane is purified while performing membrane purification of natural water provided with a suspension process of a filtration process immediately before the backwashing. In response to a decrease in processing capacity due to clogging of the module, a backwashing process with a pause consisting of three consecutive operations of backwashing operation with backwashing water containing a disinfectant, backwashing and filtration treatment, and backwashing operation is provided. Another object of the present invention is to provide a method for purifying natural water by membrane. In addition, the present invention provides the membrane purification method for natural water, wherein the backwashing and filtration treatments are suspended for 1 to 10 hours.
【0007】[0007]
【作用】本発明の第一の態様は、中空糸型の濾過膜モジ
ュールに原水を供給するための原水供給ポンプを所定時
間停止することによって濾過処理を休止させる過程を有
する。この過程を「濾過処理の休止過程」という。当該
過程により、濾過処理により加圧され、圧密化していた
中空糸型の濾過膜モジュールの「原水供給側分離膜面の
目詰まり物質」は、一時的に放圧され、濾過膜面との付
着力が緩和されるため、膜面から濾過膜面との付着力が
緩和されるため、膜面から剥離し易い状態になる。な
お、前記の「所定」とは、膜モジュールの処理能力の状
況に応じて本発明を実施する際に、実施者において適宜
定められることを意味する(以下における「所定」も同
様である)。従って、当該過程を逆洗の直前に設けるこ
とにより、逆洗効率が向上する。なお、逆洗水に殺菌剤
を含ませて、中空糸型の濾過膜モジュールの殺菌ならび
に濾過膜表面に付着した微生物や有機物を分解させるこ
とも可能である。本発明の第二の態様は、濾過処理後に
殺菌剤を含む逆洗水による逆洗操作、逆洗および濾過
処理の休止操作、逆洗操作の連続した三操作からな
る「休止付き逆洗過程」を設ける。この場合、逆洗およ
び濾過処理の休止操作で、化学的に殺菌剤による中空
糸型の濾過膜の洗浄を十分に行ない、かつ、膜への高圧
負荷を緩和させる。以下、詳細に本発明を説明する。
The first aspect of the present invention has a step of stopping the filtration process by stopping the raw water supply pump for supplying raw water to the hollow fiber type filtration membrane module for a predetermined time. This process is referred to as a “stop process of the filtration process”. In this process, the "clogging substance on the raw water supply side separation membrane surface" of the hollow fiber type filtration membrane module which has been pressurized and consolidated by the filtration treatment is temporarily released and attached to the filtration membrane surface. Since the adhesive force is eased, the adhesive force from the membrane surface to the filtration membrane surface is eased, so that the membrane surface is easily separated. The above “predetermined” means that the present invention is appropriately determined by the practitioner when implementing the present invention according to the state of the processing capability of the membrane module (the same applies to “predetermined” below). Therefore, by providing the process immediately before the backwash, the backwash efficiency is improved. In addition, it is also possible to add a bactericide to the backwash water to sterilize the hollow fiber type filtration membrane module and decompose microorganisms and organic substances attached to the filtration membrane surface. The second embodiment of the present invention is a "backwashing process with a pause" consisting of a backwashing operation with a backwashing water containing a bactericide after a filtration treatment, a backwashing and a suspension operation of a filtration treatment, and a continuous backwashing operation of three operations. Is provided. In this case, the hollow fiber type filtration membrane is sufficiently washed with a bactericide and the high-pressure load on the membrane is reduced by suspending the backwashing and filtration treatments. Hereinafter, the present invention will be described in detail.
【0008】中空糸型の濾過膜モジュールを用いた水浄
化システムでは、濾過処理による透過水生成と、中空糸
型の濾過膜の目詰まりを防ぐための逆洗とを交互に実施
し、これを通常運転とするのが一般的である。ここに逆
洗は、原水供給側分離膜面に付着した濁質物質の除去の
ため、圧力制御もしくは定時間間隔で行われる。すなわ
ち、中空糸型の濾過膜に対し透過水生成と逆方向に逆洗
水を流入するものである。なお、洗浄後の洗浄水は洗浄
水排出経路より排出される。水浄化システムが内圧式ク
ロスフロー濾過の場合には、中空糸型の濾過膜の内面が
原水供給分離膜面となり、ここに付着した濁質物質は、
中空糸型の濾過膜の外面すなわち透過水側分離膜面から
逆洗水を注入させることにより剥離・除去される。
In a water purification system using a hollow fiber type filtration membrane module, generation of permeated water by filtration and backwashing for preventing clogging of the hollow fiber type filtration membrane are performed alternately. It is common to operate normally. Here, the backwashing is performed at a pressure control or at regular time intervals in order to remove suspended substances adhered to the separation membrane surface on the raw water supply side. That is, the backwash water flows into the hollow fiber type filtration membrane in the opposite direction to the generation of the permeated water. The cleaning water after the cleaning is discharged from the cleaning water discharge path. When the water purification system is an internal pressure type cross-flow filtration, the inner surface of the hollow fiber type filtration membrane becomes the raw water supply / separation membrane surface, and the turbid substance attached here is:
It is separated and removed by injecting backwash water from the outer surface of the hollow fiber type filtration membrane, that is, the permeated water side separation membrane surface.
【0009】本発明の第一の膜浄化方法は、中空糸型の
濾過膜モジュールを用いた水浄化システムの通常運転に
おける「逆洗」の直前に、前記した「濾過処理の休止過
程」を設けるものである。当該過程により加圧されて圧
密化していた原水供給側分離膜面の目詰まりが一時的に
放圧され、膜面から剥離し易い状態となり、このため透
過水の流れとは逆方向に行われる逆洗は、その逆洗効率
が向上する。従って、当該過程を逆洗の直前に設けるこ
とにより、効果的な逆洗が可能となる。なお、濾過処理
の休止過程は、30秒から15分であることが好まし
く、特には2〜10分の範囲であることが好ましい。こ
の範囲で目詰まり物質の圧力緩和が起こり、逆洗効率が
向上し、かつ、濾過処理の遅延による処理量の著しい低
下も生じないからである。さらに、濾過処理の休止過程
は毎逆洗時に設けてもよいし、濾過性能が低下した場合
にのみ設けてもよい。
In the first membrane purification method of the present invention, the above-mentioned "stopping process of filtration treatment" is provided immediately before "backwashing" in a normal operation of a water purification system using a hollow fiber type filtration membrane module. Things. The clogging of the raw water supply side separation membrane surface, which was pressurized and compacted by the process, is temporarily released, and the membrane is easily peeled off from the membrane surface, so that the flow is performed in the opposite direction to the flow of the permeated water. Backwashing improves the backwashing efficiency. Therefore, by providing this process immediately before backwashing, effective backwashing becomes possible. The suspension process of the filtration treatment is preferably for 30 seconds to 15 minutes, and particularly preferably for 2 to 10 minutes. This is because the pressure of the clogging substance is relaxed in this range, the backwashing efficiency is improved, and the processing amount is not significantly reduced due to the delay of the filtration processing. Furthermore, the pause process of the filtration treatment may be provided at each backwash, or may be provided only when the filtration performance is reduced.
【0010】本発明の第二の態様は、中空糸型の濾過膜
モジュールを用いた水浄化システムにおける天然水の膜
浄化方法として、「休止付き逆洗過程」を設けるもので
ある。この過程は、水浄化システムの通常濾過運転稼働
中に、数十時間に1回設けてもよいし、濾過膜の性能が
低下した場合にのみ設けてもよい。なお、濾過膜の性能
の低下は、フラックスの低下や濾過圧の上昇の程度など
より把握される指標を目安とする。この過程は、まず濾
過処理後に殺菌剤を含む逆洗水による逆洗操作を実施
し、その後逆洗および濾過処理の休止操作を設けるも
のである。このことにより中空糸型の濾過膜は殺菌剤が
満たされた状態となり、薬剤による濁質物質の分解が進
み、中空糸型の濾過膜への圧力負荷が緩和されるととも
に化学的分解による濁質物質の除去が可能となる。次い
で、逆洗操作により濁質物質の系外への除去を行い、
その後濾過運転を継続する。なお、逆洗および濾過処理
の休止操作は、1〜10時間であることが好ましく、
特には2〜5時間の範囲が好ましい。この範囲で濁質物
質の分解が十分なされ、十分な圧力負荷の緩和がなされ
るからである。なお、水浄化システムの通常運転に、前
記した「濾過処理の休止過程」を設けた濾過運転を行
い、さらに、数十時間に一回の頻度で当該「休止付き逆
洗過程」を設けた濾過運転を行ってもよい。
[0010] A second aspect of the present invention is to provide a "backwash process with a pause" as a method for purifying natural water in a water purification system using a hollow fiber type filtration membrane module. This process may be provided once every several tens of hours during the normal filtration operation of the water purification system, or may be provided only when the performance of the filtration membrane is reduced. It should be noted that a decrease in the performance of the filtration membrane is taken as an index based on the degree of decrease in the flux or increase in the filtration pressure. In this process, first, after the filtration treatment, a backwash operation with backwash water containing a bactericide is performed, and thereafter, the backwash and the filtration treatment are stopped. As a result, the hollow fiber type filtration membrane is filled with a bactericide, the decomposition of the turbid substance by the chemical proceeds, the pressure load on the hollow fiber type filtration membrane is reduced, and the turbidity due to the chemical decomposition is reduced. The substance can be removed. Next, the suspended substance is removed from the system by a backwashing operation,
Thereafter, the filtration operation is continued. In addition, the pause operation of the backwashing and the filtration treatment is preferably 1 to 10 hours,
Particularly, the range of 2 to 5 hours is preferable. This is because the suspended substance is sufficiently decomposed in this range, and the pressure load is sufficiently alleviated. In addition, in the normal operation of the water purification system, a filtration operation provided with the above-mentioned "stop process of the filtration process" is performed, and the filtration operation provided with the "backwash process with a stop" is performed once every several tens of hours. You may drive.
【0011】本発明においては、逆洗には、濾過膜モジ
ュールからの透過水または別途供給される清浄水を用い
ることができる。また、別途供給される清浄水として前
記濾過膜モジュールからの透過水に殺菌剤を添加したも
のを用いてもよい。殺菌剤としては、次亜塩素酸ナトリ
ウム、塩素、過酸化水素およびオゾンなどの酸化性殺菌
剤、クエン酸およびシュウ酸などの有機酸、塩酸および
硝酸などの無機酸、水酸化ナトリウムなどのアルカリお
よびカチオン系、アニオン系、ノニオン系および両性界
面活性剤等を使用することができる。中でも有機性の目
詰まり物質を効果的に酸化分解できる次亜塩素酸ナトリ
ウムが適する。
In the present invention, permeated water from the filtration membrane module or clean water separately supplied can be used for backwashing. Further, as the separately supplied clean water, a water obtained by adding a germicide to permeated water from the filtration membrane module may be used. Disinfectants include oxidizing disinfectants such as sodium hypochlorite, chlorine, hydrogen peroxide and ozone; organic acids such as citric acid and oxalic acid; inorganic acids such as hydrochloric acid and nitric acid; alkalis such as sodium hydroxide; Cationic, anionic, nonionic, amphoteric surfactants and the like can be used. Among them, sodium hypochlorite, which can effectively oxidize and decompose organic clogging substances, is suitable.
【0012】本発明は、中空糸型の濾過膜モジュールを
用いた水浄化システムを対象とし、中空糸型限外または
精密濾過膜モジュールを用いることができる。これら中
空糸型の濾過膜モジュールの材質としては、親水性高分
子材料である酢酸セルロース、ポリアクリロニトリル重
合体、ポリビニルアルコール等を用いることが可能であ
り、特には酢酸セルロースが逆洗効果が顕著に現れるた
めに好ましい。
The present invention is directed to a water purification system using a hollow fiber type filtration membrane module, and can use a hollow fiber type ultrafiltration or microfiltration membrane module. As a material of these hollow fiber type filtration membrane modules, it is possible to use a hydrophilic polymer material such as cellulose acetate, polyacrylonitrile polymer, polyvinyl alcohol, and the like. Preferred to appear.
【0013】浄化用に供給される原水としては、地下
水、雨水、河川水および湖沼水等の天然水を用いること
ができる。
As raw water supplied for purification, natural water such as groundwater, rainwater, river water and lake water can be used.
【0014】以下に中空糸型の濾過膜モジュールを用い
た内圧式クロスフロー濾過による水浄化システムにおい
て、本発明の天然水の膜浄化方法について、図面を参照
して説明する。
A method for purifying a natural water membrane according to the present invention in a water purification system by internal pressure type cross flow filtration using a hollow fiber type filtration membrane module will be described below with reference to the drawings.
【0015】まず、本発明の「濾過処理の休止過程」を
設けた天然水の膜浄化方法について説明する。水浄化シ
ステムは、透過水生成と中空糸型の濾過膜モジュールの
目詰まりを防ぐための逆洗とを交互に実施している。こ
こに、透過水生成時と逆洗時におけるポンプ、流路弁の
操作は以下の通りである。透過水生成時においては、透
過水自動弁13を開、洗浄水排出自動弁14、逆洗自動
弁19は閉の状態で原水供給ポンプ11により原水を中
空糸型の濾過膜モジュールに供給して濾過を行い、生成
した透過水を透過水タンク17に貯留する。なお、中空
糸型の濾過膜モジュールを透過しない原水は循環経路1
6、原水供給ポンプ11を経て再び中空糸型の濾過膜モ
ジュール12に送られる。一方本発明の第一の態様によ
る逆洗時には、まず原水ポンプ11が停止され、中空糸
型の濾過膜モジュール12への原水の供給が30秒〜1
0分間停止される。次に、原水供給ポンプ11を停止さ
せて原水の供給を停止したまま、中空糸型の濾過膜モジ
ュール12の原水供給側分離膜面に付着した濁質物質を
除去するために、透過水生成時とは逆方向に中空糸型の
濾過膜モジュール12に逆洗水を供給する。膜面に付着
した濁質物質を剥離した後、濁質物質を系外へ排出す
る。中空糸型の濾過膜モジュール12の逆洗は、例えば
30〜60分に一度程度の頻度で行う。逆洗水に透過水
を使用する場合には、透過水自動弁13を閉、洗浄水排
出自動弁14、逆洗自動弁19を開とすると共に、逆洗
水供給ポンプ18により透過水タンク17の一部を透過
水生成時とは逆方向に中空糸型の濾過膜モジュール12
に、例えば約1分間供給する。これにより中空糸型の濾
過膜モジュール12の原水供給側分離膜面の濁質物質を
剥離した後、濁質物質を高濃度に含有した逆洗水を逆洗
水排出経路15を経て逆洗水排出自動弁14から系外へ
排出させる。なお、殺菌剤を貯留する薬剤タンク21を
設けて、逆洗水に殺菌剤を含ませることも可能である。
かかる場合には、逆洗水供給ポンプ18の稼働と共に薬
剤供給ポンプ22を稼働させ、合わせて薬剤自動弁25
を開とする。
First, a method for purifying natural water membranes provided with the "stop process of filtration treatment" of the present invention will be described. The water purification system alternately performs permeated water generation and backwashing to prevent clogging of the hollow fiber type filtration membrane module. Here, the operation of the pump and the flow path valve at the time of generation of permeated water and at the time of backwashing are as follows. At the time of generation of permeated water, the raw water is supplied to the hollow fiber type filtration membrane module by the raw water supply pump 11 with the automatic permeated water valve 13 opened, the automatic cleaning water discharge valve 14 and the automatic backwash valve 19 closed. Filtration is performed, and the generated permeate is stored in a permeate tank 17. The raw water that does not pass through the hollow fiber type filtration membrane module is
6. It is sent to the hollow fiber type filtration membrane module 12 again through the raw water supply pump 11. On the other hand, at the time of backwashing according to the first aspect of the present invention, first, the raw water pump 11 is stopped, and supply of raw water to the hollow fiber type filtration membrane module 12 is performed for 30 seconds to 1 hour.
Stop for 0 minutes. Next, with the raw water supply pump 11 stopped and the supply of raw water stopped, in order to remove turbid substances attached to the raw water supply side separation membrane surface of the hollow fiber type filtration membrane module 12, The backwash water is supplied to the hollow fiber type filtration membrane module 12 in the opposite direction. After the suspended substance adhered to the membrane surface is peeled off, the suspended substance is discharged out of the system. Backwashing of the hollow fiber type filtration membrane module 12 is performed, for example, about once every 30 to 60 minutes. When permeated water is used as the backwash water, the automatic permeated water valve 13 is closed, the automatic flush water discharge valve 14 and the automatic backwash valve 19 are opened, and the permeated water tank 17 is controlled by the backwash water supply pump 18. Part of the hollow fiber type filtration membrane module 12
For about 1 minute. As a result, the turbid substance on the raw water supply side separation membrane surface of the hollow fiber type filtration membrane module 12 is peeled off, and then the backwash water containing the turbid substance at a high concentration is passed through the backwash water discharge path 15 to the backwash water. It is discharged from the automatic discharge valve 14 to the outside of the system. In addition, it is also possible to provide a chemical tank 21 for storing a germicide, and to make the backwash water contain a germicide.
In such a case, the medicine supply pump 22 is operated together with the operation of the backwash water supply pump 18, and the automatic medicine valve 25 is also operated.
Open.
【0016】次に本発明による「休止付き逆洗過程」を
伴う膜洗浄方法について説明する。この膜洗浄方法を伴
う水浄化システムにおいては、透過水生成と中空糸型の
濾過膜モジュールの目詰まりを防ぐための逆洗とを交互
に実施し、この逆洗が上記した濾過処理の休止過程を設
けた膜洗浄方法を実施している場合でもよい。通常の透
過水生成時には、上記と同様にポンプ・弁等が稼働し、
次に休止付き逆洗過程に入ると、殺菌剤を含む逆洗水に
よる逆洗操作、すなわち原水供給ポンプ11を停止
し、逆洗自動弁19、薬剤自動弁25を開とし、逆洗水
供給ポンプ18ならびに薬剤供給ポンプ22により殺菌
剤を含有した逆洗水により逆洗を1〜3分行う。その
後、逆洗および濾過処理の休止操作、すなわち原水供
給ポンプ11は停止したまま、逆洗水供給ポンプ18な
らびに薬剤供給ポンプ22を停止し、逆洗自動弁19、
薬剤自動弁25を閉とし1〜10時間、透過水生成なら
びに逆洗を共に停止する期間を設ける。次に、逆洗自動
弁19を開とし、逆洗水供給ポンプ18により逆洗操作
を行う。なお逆洗操作においても、薬剤自動弁25
を開とし薬剤供給ポンプ22により薬剤を逆洗水に含め
ることも可能である。
Next, a description will be given of a method of cleaning a film with a “backwash process with pause” according to the present invention. In the water purification system with this membrane cleaning method, generation of permeated water and backwashing to prevent clogging of the hollow fiber type filtration membrane module are alternately performed, and this backwashing is a process of stopping the above-described filtration process. May be carried out when the membrane cleaning method provided with. During normal permeate generation, pumps and valves operate in the same manner as above,
Next, in the backwashing process with a pause, the backwashing operation using the backwashing water containing the sterilizing agent, that is, the raw water supply pump 11 is stopped, the backwashing automatic valve 19 and the chemical automatic valve 25 are opened, and the backwashing water supply is performed. Backwashing is performed for 1-3 minutes with backwash water containing a bactericide by the pump 18 and the chemical supply pump 22. Thereafter, the backwashing and filtration processes are stopped, that is, the backwash water supply pump 18 and the chemical supply pump 22 are stopped while the raw water supply pump 11 is stopped, and the backwash automatic valve 19,
The automatic chemical valve 25 is closed and a period is provided for stopping permeated water generation and backwashing for 1 to 10 hours. Next, the backwash automatic valve 19 is opened, and the backwash water supply pump 18 performs a backwash operation. In addition, also in the backwashing operation, the automatic chemical valve 25
Can be opened and the medicine supplied to the backwash water by the medicine supply pump 22.
【0017】[0017]
【実施例】以下、本発明を実施例によりさらに具体的に
説明する。
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.
【0018】(実施例1)中空糸型の濾過膜モジュール
として酢酸セルロース製の限外濾過膜モジュール(分画
分子量15万、有効膜面積50m2)を用いて河川水の
内圧式濾過運転を行った。運転は「濾過処理の休止過
程」を設ける方法で行った。すなわち、45分間の透過
水生成期間の後に、原水供給ポンプを10分間停止して
濾過処理を休止した。その後、圧力1.7Kg/cm2
で透過水を逆洗水として中空糸膜の外壁面側から1分間
圧入して中空糸膜の内壁面の付着物を逆洗した。なお、
逆洗水には透過水に次亜塩素酸ナトリウムを注入し、濃
度5mg/リットルに調整した水溶液を用いた。上記の
一連の操作を自動弁を用いて周期的に行い、濾過速度の
経日変化を測定した結果、濾過速度は低下することなく
安定した運転が継続した。
(Example 1) An internal pressure filtration operation of river water was carried out using a cellulose acetate ultrafiltration membrane module (fraction molecular weight: 150,000, effective membrane area: 50 m 2 ) as a hollow fiber type filtration membrane module. Was. The operation was performed by a method of providing a "stop process of filtration treatment". That is, after the permeated water generation period of 45 minutes, the raw water supply pump was stopped for 10 minutes to suspend the filtration process. Thereafter, the pressure was 1.7 kg / cm 2.
The permeated water was used as backwashing water for 1 minute from the outer wall surface side of the hollow fiber membrane to press-back it, and the deposits on the inner wall surface of the hollow fiber membrane were backwashed. In addition,
As the backwashing water, an aqueous solution prepared by injecting sodium hypochlorite into permeated water and adjusting the concentration to 5 mg / liter was used. The above series of operations were periodically performed using an automatic valve, and the daily change in the filtration rate was measured. As a result, stable operation was continued without decreasing the filtration rate.
【0019】(実施例2)実施例1と同じ中空糸型の膜
モジュールを用いて、「休止付き逆洗過程」を設けて内
圧式濾過運転を行った。すなわち、45分ごとに1分間
の逆洗を周期的に行う膜浄化方法において、逆洗操
作、2時間の濾過処理の休止、逆洗操作の連続した
三操作を30時間に1回設けた。なお、逆洗時には実施
例1と同様に殺菌剤として次亜塩素酸ナトリウムを含む
逆洗水(NaClO濃度5mg/リットル)を用いた。
この運転操作では濾過速度は低下しなかった。
(Example 2) Using the same hollow fiber type membrane module as in Example 1, an internal pressure filtration operation was performed by providing a "backwashing process with pause". That is, in the membrane purification method in which backwashing is periodically performed for 1 minute every 45 minutes, three successive operations of a backwashing operation, a suspension of filtration treatment for 2 hours, and a backwashing operation are provided once every 30 hours. At the time of back washing, back washing water (NaClO concentration 5 mg / liter) containing sodium hypochlorite was used as a bactericide as in Example 1.
This operation did not reduce the filtration rate.
【0020】(比較例)実施例1と同じ中空糸型の膜モ
ジュールを用いる運転操作において、「濾過処理の休止
過程」および「休止付き逆洗過程」を設けることなく、
45分ごとに1分間の逆洗操作のみを行った。実施例1
および2の前後に計3回の比較例を実施したが、濾過速
度はいずれも経時的に減少した。
(Comparative Example) In the operation using the same hollow fiber type membrane module as in Example 1, the "filtration process pause process" and the "backwash process with pause" were not provided.
Only a 1 minute backwash operation was performed every 45 minutes. Example 1
A total of three comparative examples were performed before and after the steps 2 and 3, but the filtration rate decreased with time.
【0021】上述の実施例1、実施例2および比較例の
濾過運転結果を一連の実験データとして図2に示す。
FIG. 2 shows a series of experimental data showing the results of the filtration operation of the above-described Examples 1, 2 and Comparative Examples.
【0022】[0022]
【発明の効果】本発明による膜洗浄方法を伴う天然水の
膜浄化方法を用いることにより、中空糸型の濾過膜の目
詰まり処理は極めて容易な操作により行われ、しかも迅
速かつ確実に中空糸型の濾過膜の機能が回復できる。し
かも本発明によれば、中空糸型の濾過膜に対する圧力負
荷が緩和されるため、中空糸型の濾過膜モジュールの延
命を図ることが可能である。加えて、殺菌剤の併用によ
り、中空糸型の濾過膜モジュールの殺菌のみならず濁質
物質を化学的に分解させ、膜自体へ圧力負荷をより緩和
する。さらに、中空糸型の濾過膜の殺菌剤への浸漬時間
が長いため、無駄な殺菌剤を使用せずに膜洗浄が可能と
なる。従って、殺菌剤の使用量を低減することが可能と
なり、費用のみならず環境へ与える影響も低減すること
が可能となる。
According to the present invention, the method for purifying natural water with the membrane washing method according to the present invention enables the hollow fiber type filtration membrane to be clogged by an extremely easy operation, and to quickly and reliably carry out the hollow fiber filtration. The function of the type filtration membrane can be restored. Moreover, according to the present invention, the pressure load on the hollow fiber type filtration membrane is reduced, so that the life of the hollow fiber type filtration membrane module can be extended. In addition, the combined use of a disinfectant not only disinfects the hollow fiber type filtration membrane module but also chemically decomposes turbid substances and further reduces the pressure load on the membrane itself. Further, since the immersion time of the hollow fiber type filtration membrane in the sterilizing agent is long, the membrane can be washed without using a useless sterilizing agent. Therefore, it is possible to reduce the use amount of the bactericide, and it is possible to reduce not only the cost but also the influence on the environment.
【図面の簡単な説明】[Brief description of the drawings]
【図1】 本発明による天然水の膜浄化方法を実施する
ための浄化装置の一例を示す。
FIG. 1 shows an example of a purification device for carrying out a method for purifying a natural water membrane according to the present invention.
【図2】 天然水の水浄化における本発明の実施例の結
果を示した図である。
FIG. 2 is a view showing a result of an example of the present invention in water purification of natural water.
【符号の説明】[Explanation of symbols]
10 逆止弁 11 原水供給ポンプ 12 中空糸型の濾過膜モジュール 14 洗浄水排出自動弁 15 逆洗水排出経路 16 循環経路 17 透過水タンク 18 逆洗水供給ポンプ 19 逆洗自動弁 21 薬剤タンク 22 薬剤供給ポンプ 25 薬剤自動弁 DESCRIPTION OF SYMBOLS 10 Check valve 11 Raw water supply pump 12 Hollow fiber type filtration membrane module 14 Washing water discharge automatic valve 15 Backwash water discharge path 16 Circulation path 17 Permeated water tank 18 Backwash water supply pump 19 Backwash automatic valve 21 Chemical tank 22 Drug supply pump 25 Automatic drug valve
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 FI B01D 71/16 B01D 71/16 (56)参考文献 特開 平8−141375(JP,A) (58)調査した分野(Int.Cl.7,DB名) C02F 1/44 B01D 61/00 - 71/16 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI B01D 71/16 B01D 71/16 (56) References JP-A-8-141375 (JP, A) (58) Fields investigated (Int. .Cl. 7 , DB name) C02F 1/44 B01D 61/00-71/16

Claims (6)

    (57)【特許請求の範囲】(57) [Claims]
  1. 【請求項1】 中空糸型の限外または精密濾過膜モジュ
    ールを用いて天然水を濾過しながら、中空糸型の濾過膜
    モジュールを該濾過膜モジュールからの透過水または別
    途供給される清浄水により圧力制御またはあらかじめ定
    められた周期で所定圧力範囲で間欠的な逆洗を行う天然
    水の膜浄化方法において、前記逆洗の直前に濾過膜モジ
    ュールに原水を供給するための原水供給ポンプを所定時
    間停止する濾過処理の休止過程(但し、この休止過程に
    おいて次亜塩素酸ナトリウム溶液に濾過膜モジュールを
    接触させる場合を除く)を設けることを特徴とする天然
    水の膜浄化方法。
    1. While filtering natural water using a hollow fiber type ultrafiltration or microfiltration membrane module, a hollow fiber type filtration membrane module is filtered by permeated water from the filtration membrane module or separately supplied clean water. in the membrane method of purifying natural water performing intermittent backwashing at a predetermined pressure range in the pressure control or predetermined period, filtration membranes character immediately preceding the backwash
    When the raw water supply pump for supplying raw water to the
    Pause process of the filtration process that stops for a while (however,
    The filtration membrane module in the sodium hypochlorite solution
    Excluding the case of contact) .
  2. 【請求項2】 前記濾過処理の休止過程が30秒〜15
    分であることを特徴とする請求項1記載の天然水の膜浄
    化方法。
    2. The method according to claim 1, wherein the pause of the filtration is 30 seconds to 15 seconds.
    2. The method for purifying natural water membrane according to claim 1, wherein
  3. 【請求項3】 前記中空糸型の限外または精密濾過膜モ
    ジュールが酢酸セルロース製濾過膜モジュールであるこ
    とを特徴とする請求項1記載の天然水の膜浄化方法。
    3. The method for purifying natural water according to claim 1, wherein the hollow fiber type ultrafiltration or microfiltration membrane module is a cellulose acetate filtration membrane module.
  4. 【請求項4】 中空糸型の限外または精密濾過膜モジュ
    ールを用いて天然水を濾過しながら、中空糸型の濾過膜
    モジュールを該濾過膜モジュールからの透過水または別
    途供給される清浄水により圧力制御またはあらかじめ定
    められた周期で所定圧力範囲で間欠的な逆洗を行う天然
    水の膜浄化方法において、濾過膜モジュールの目詰まり
    による処理能力低下に応じて、殺菌剤を含む逆洗水によ
    る逆洗操作、逆洗および濾過処理の休止操作、逆洗
    操作の連続した三操作からなる休止付き逆洗過程を設
    けることを特徴とする天然水の膜浄化方法。
    4. While filtering natural water using a hollow fiber type ultrafiltration or microfiltration membrane module, the hollow fiber type filtration membrane module is filtered by permeated water from the filtration membrane module or clean water separately supplied. In a natural water membrane purification method in which pressure control or intermittent backwashing is performed intermittently in a predetermined pressure range at a predetermined cycle, the backwashing water containing a bactericide is used in accordance with a reduction in processing capacity due to clogging of a filtration membrane module. A method for purifying natural water membranes, characterized by providing a backwashing process with a backstop consisting of three successive backwashing operations, a backwashing operation, a backwashing operation, and a backwashing operation, and a backwashing operation.
  5. 【請求項5】 中空糸型の限外または精密濾過膜モジュ
    ールを用いて天然水を濾過しながら、中空糸型の濾過膜
    モジュールを該濾過膜モジュールからの透過水または別
    途供給される清浄水により圧力制御またはあらかじめ定
    められた周期で所定圧力範囲で間欠的な逆洗を行う天然
    水の膜浄化方法において、前記逆洗の直前に濾過処理の
    休止過程を設けた天然水の膜浄化を行いながら、濾過膜
    モジュールの目詰まりによる処理能力低下に応じて、殺
    菌剤を含む逆洗水による逆洗操作、逆洗および濾過処
    理の休止操作、逆洗操作の連続した三操作からなる
    休止付き逆洗過程を設けることを特徴とする天然水の膜
    浄化方法。
    5. While filtering natural water using a hollow fiber type ultra or microfiltration membrane module, the hollow fiber type filtration membrane module is filtered by permeated water from the filtration membrane module or separately supplied clean water. In a natural water membrane purification method of performing intermittent backwashing in a predetermined pressure range at a predetermined cycle with pressure control or a predetermined cycle, while performing membrane purification of natural water provided with a suspension process of a filtration process immediately before the backwashing, In accordance with the decrease in processing capacity due to clogging of the filter membrane module, backwashing with backwashing using backwashing water containing a germicide, backwashing and filtering, and backwashing consisting of three consecutive backwashing operations. A method for purifying a membrane of natural water, comprising the steps of:
  6. 【請求項6】 逆洗および濾過処理の休止操作が1〜
    10時間であることを特徴とする請求項4または5記載
    の天然水の膜浄化方法。
    6. The method according to claim 1, wherein the suspending operation of the backwashing and the filtration is performed in the following manner.
    The method for purifying natural water membrane according to claim 4 or 5, wherein the treatment time is 10 hours.
JP03174795A 1995-01-27 1995-01-27 Natural water membrane purification method Expired - Lifetime JP3194684B2 (en)

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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP03174795A JP3194684B2 (en) 1995-01-27 1995-01-27 Natural water membrane purification method

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JP3194684B2 true JP3194684B2 (en) 2001-07-30

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* Cited by examiner, † Cited by third party
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JPH10309446A (en) * 1997-03-13 1998-11-24 Nok Corp Purification device
JPH119973A (en) * 1997-06-26 1999-01-19 Ebara Corp Method for filtration back-washing of membrane module for turbidity removal
JP3462975B2 (en) * 1997-07-04 2003-11-05 株式会社荏原製作所 Method for backwashing filtration of membrane module for turbidity
JP3405911B2 (en) * 1997-12-25 2003-05-12 株式会社荏原製作所 Backwashing method of internal pressure type turbidity membrane module by flow rate and pressure fluctuation
JP4710107B2 (en) * 2000-07-13 2011-06-29 栗田工業株式会社 Operation method of membrane separator
JP2008539054A (en) * 2005-04-29 2008-11-13 シーメンス・ウォーター・テクノロジーズ・コーポレイションSiemens Water Technologies Corp. Chemical cleaning for membrane filters
KR20080045231A (en) 2005-08-22 2008-05-22 지멘스 워터 테크놀로지스 코포레이션 An assembly for water filtration using a tube manifold to minimise backwash
JP4804097B2 (en) * 2005-10-11 2011-10-26 ダイセル化学工業株式会社 Continuous operation method of water purification system
JP2007330925A (en) * 2006-06-16 2007-12-27 Daicen Membrane Systems Ltd Leach operation method
JP2007330924A (en) * 2006-06-16 2007-12-27 Daicen Membrane Systems Ltd Leach operation method
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CA2731774A1 (en) 2008-07-24 2010-01-28 Siemens Water Technologies Corp. Frame system for membrane filtration modules
WO2010142673A1 (en) 2009-06-11 2010-12-16 Siemens Water Technologies Corp. Methods for cleaning a porous polymeric membrane and a kit for cleaning a porous polymeric membrane
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