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JP3194679B2 - Cleaning method for filtration membrane module - Google Patents

Cleaning method for filtration membrane module

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Publication number
JP3194679B2
JP3194679B2 JP31130494A JP31130494A JP3194679B2 JP 3194679 B2 JP3194679 B2 JP 3194679B2 JP 31130494 A JP31130494 A JP 31130494A JP 31130494 A JP31130494 A JP 31130494A JP 3194679 B2 JP3194679 B2 JP 3194679B2
Authority
JP
Japan
Prior art keywords
filtration membrane
membrane module
water
filtration
cleaning
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 - Fee Related
Application number
JP31130494A
Other languages
Japanese (ja)
Other versions
JPH08141375A (en
Inventor
史野 安積
修志 中塚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daicel Corp
Original Assignee
Daicel Chemical Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Daicel Chemical Industries Ltd filed Critical Daicel Chemical Industries Ltd
Priority to JP31130494A priority Critical patent/JP3194679B2/en
Publication of JPH08141375A publication Critical patent/JPH08141375A/en
Application granted granted Critical
Publication of JP3194679B2 publication Critical patent/JP3194679B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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  • Separation Using Semi-Permeable Membranes (AREA)

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、水浄化システムの濾過
膜モジュールの洗浄方法に関し、更に詳しくは特定の薬
剤へ濾過膜を接触させ、その後フラッシングあるいは逆
洗操作を行うことにより濾過膜に付着した水不溶性未透
過物質を除去し、濾過膜モジュールの機能を回復させる
濾過膜モジュールの洗浄方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a filtration membrane module of a water purification system, and more particularly, to a method for contacting a filtration membrane with a specific agent and then performing a flushing or backwashing operation to attach the filtration membrane to the filtration membrane. The present invention relates to a method for cleaning a filtration membrane module for removing a water-insoluble unpermeated substance and restoring the function of the 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−沈殿−砂濾過−塩素殺菌工程を経
る方法に代わる新たな方法として注目されている。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
あり、全量濾過と比較して原水濁度の変動に強いことか
ら各種の試行がなされている。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、この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てい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じる。
2. Description of the Related Art In recent years, a water purification system to which a membrane separation technique is applied has been attracting attention as a new method which replaces the conventional method of agglomeration-sedimentation-sand filtration-chlorine sterilization. As a water purification system using a separation membrane, there is a cross-flow filtration, and various trials have been made since the water purification system is more resistant to fluctuations in raw water turbidity than full-volume filtration. 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 with this cross-flow filtration, the turbid substances contained in the raw water are stacked on the surface of the separation membrane over the elapse 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、一般的に逆流洗浄(以下、逆洗と称する。)
が行われている。しかし、低濃度の次亜塩素酸ナトリウ
ム(NaClO)溶液による逆洗とクロスフロー濾過を
交互に実施しても、長時間の連続運転を行う中で次第に
剥離できない非透過物質が膜面および膜内部に蓄積し、
水処理能力が低下する。そこで、数か月に一度程度、濾
過膜モジュールを薬品で処理して濾過膜モジュールの表
面などに付着した非透過物質を除去し、濾過膜モジュー
ルの水処理能力を回復させる方法が行われている。
[0003] The clogging causes an interruption of the operation of the water purification system. Therefore, in order to eliminate or prevent the clogging, backwashing (hereinafter referred to as "backwashing") is generally performed.
Has been done. However, even if backwashing with a low-concentration sodium hypochlorite (NaClO) solution and cross-flow filtration are performed alternately, non-permeable substances that cannot be peeled off gradually during the continuous operation for a long period of time will be generated on the membrane surface and inside the membrane. Accumulate in
Water treatment capacity decreases. Therefore, once every few months, a method of treating the filtration membrane module with a chemical to remove non-permeated substances attached to the surface of the filtration membrane module and recovering the water treatment capacity of the filtration membrane module has been performed. .

【0004】[0004]

【発明が解決しようとする課題】この薬品洗浄操作にお
いては、薬品が有毒でその後の濾過処理操作に悪影響を
及ぼすことがなく、また、濾過膜性能の劣化を起こさな
いことが重要であり、少量の薬品で非透過物質を迅速か
つ完全に濾過膜から除去し、濾過膜の透水性能を回復さ
せることが望まれる。
In this chemical cleaning operation, it is important that the chemical is not toxic and does not adversely affect the subsequent filtration operation and that the performance of the filtration membrane does not deteriorate. It is desired to quickly and completely remove non-permeate substances from the filtration membrane by using the above chemicals to restore the water permeability of the filtration membrane.

【0005】濾過膜モジュールの洗浄に使用される薬品
としては界面活性剤、酸、アルカリ酵素などがある。し
かし、表流水を浄化するため使用される濾過膜モジュー
ルの洗浄の場合、例えば、界面活性剤、酵素入り洗剤な
どを使用すると、洗浄後の濾過膜モジュールを透過水等
で丹念にすすぐことによりモジュール内の薬剤を完全に
除かなければ、最終生成物である上水が人体に悪影響を
及ぼすことになる。このような使用薬剤を濾過膜モジュ
ールから除去する多大な困難に加え、多量の洗浄水量が
生成する結果となり、洗浄排水の処理によりコストが必
要となる。一方、酸あるいはアルカリなどを使用した場
合には、これらの高濃度の薬品の使用が要求されるが、
これは濾過膜モジュール自体の損傷を招き、洗浄条件の
設定も難しい。さらに、使用済み排水の中和処理などの
後処理も必要となり、界面活性剤などを使用した場合と
同様に排水処理コストの増加にもつながる。そこで表流
水を浄化する濾過膜モジュールの洗浄においては、薬品
が無害であることはもちろんのこと、濾過膜モジュール
自体に対する劣化の影響がなく、安定で効果的な洗浄力
を有し、かつ簡便な洗浄方法の開発が強く望まれてい
る。
[0005] Chemicals used for washing the filtration membrane module include surfactants, acids and alkaline enzymes. However, in the case of washing a filtration membrane module used for purifying surface water, for example, if a surfactant or a detergent containing an enzyme is used, the module can be cleaned by thoroughly rinsing the washed filtration membrane module with permeated water or the like. If the drug inside is not completely removed, the final product, clean water, will have an adverse effect on the human body. In addition to the great difficulty in removing such used chemicals from the filtration membrane module, a large amount of washing water is generated, and the cost of treating the washing wastewater is increased. On the other hand, when acids or alkalis are used, the use of these high-concentration chemicals is required,
This causes damage to the filtration membrane module itself, and it is difficult to set the cleaning conditions. Further, post-treatment such as neutralization treatment of used waste water is also required, which leads to an increase in waste water treatment cost as in the case of using a surfactant or the like. Therefore, in the cleaning of the filtration membrane module for purifying surface water, not only the chemical is harmless, but also the deterioration of the filtration membrane module itself is not affected, and the stable and effective cleaning power is provided. Development of a cleaning method is strongly desired.

【0006】このような洗浄方法として、特開平5−1
03958号公報には、クエン酸とNaClOを用いて
有機性廃水の凝集分離に用いた膜モジュールの洗浄を開
示している。まず、膜をpH3.5〜4.5にしたクエ
ン酸水溶液を用いて循環洗浄する。次に同じ水溶液に膜
を浸漬し、さらに膜内に残存するクエン酸水溶液を水に
より押し出し洗浄したのち、有効塩素200mg/リッ
トル含むNaClO水溶液で膜を循環洗浄する。次に同
じ液に膜を浸漬するといった洗浄方法である。しかし、
洗浄剤としてNaClO溶液を用いた場合、原水のフミ
ン質などの有機物質がNaClOと反応し、発癌性物質
であるトリハロメタンが浄化システムの循環系内などに
残存してしまう可能性がある。
[0006] As such a cleaning method, Japanese Patent Laid-Open No. 5-1 is disclosed.
JP 03958 discloses washing of a membrane module used for coagulation and separation of organic wastewater using citric acid and NaClO. First, the membrane is circulated and washed using an aqueous citric acid solution having a pH of 3.5 to 4.5. Next, the membrane is immersed in the same aqueous solution, the aqueous citric acid solution remaining in the membrane is extruded and washed with water, and then the membrane is circulated and washed with an aqueous NaClO solution containing 200 mg / liter of available chlorine. Next, a cleaning method of immersing the film in the same liquid is used. But,
When a NaClO solution is used as a cleaning agent, organic substances such as humic substances in raw water react with NaClO, and trihalomethane, which is a carcinogen, may remain in the circulation system of the purification system.

【0007】また、特願平5−308589号には、濾
過膜モジュールの洗浄方法において、濃度5〜95mg
/リットルのNaClO溶液に濾過膜モジュールを浸漬
し、NaClO溶液の濃度と浸漬時間との積が1×10
3〜7×104(mg/リットル)・hの範囲であること
を特徴とする洗浄方法が示されている。しかし、このよ
うなNaClO溶液を用いた浸漬による洗浄操作では、
薬品浸漬後の洗浄操作が不適切な場合、濾過膜の洗浄が
不十分となり濾過膜の透水性能は回復しない。
Japanese Patent Application No. 5-308589 discloses a method for cleaning a filtration membrane module, which has a concentration of 5 to 95 mg.
Per liter of NaClO solution, the product of the concentration of the NaClO solution and the immersion time is 1 × 10
A cleaning method characterized by a range of 3 to 7 × 10 4 (mg / liter) · h is shown. However, in such a washing operation by immersion using a NaClO solution,
If the washing operation after chemical immersion is inappropriate, the washing of the filtration membrane is insufficient and the water permeability of the filtration membrane is not restored.

【0008】[0008]

【課題を解決するための手段】本発明者らは以上のよう
な問題点を克服するため鋭意検討した結果、濾過膜モジ
ュールの洗浄方法に特定濃度のNaClO溶液を使用
し、洗浄した後の操作を工夫したところ、濾過膜モジュ
ールの材質を損なわず機能を回復させ、排水の後処理も
不要でしかも管理が簡便であることを見出し、本発明を
完成するに至った。
Means for Solving the Problems The inventors of the present invention have made intensive studies to overcome the above problems, and as a result, using a NaClO solution of a specific concentration in a method for washing a filtration membrane module, and performing an operation after washing. As a result, they found that the function of the filtration membrane module was restored without damaging the material thereof, that post-treatment of waste water was unnecessary, and that the management was simple, and the present invention was completed.

【0009】すなわち、本発明は表流水の水浄化システ
ムにおける濾過膜モジュールの洗浄方法において、有効
塩素濃度10〜1000mg/リットルのNaClO溶
液に接触させる際、該NaClO溶液の有効塩素濃度と
接触時間との積が1000〜5000(mg/リット
ル)・hの範囲になるように接触させた後、で原水側の
膜表面を膜間差圧が0.3kg/cm2以下フラッシン
グするか、あるいは、逆洗を行うことを特徴とする濾過
膜モジュールの洗浄方法を提供するものである。以下に
本発明を詳細に説明する。
That is, the present invention relates to a method for cleaning a filtration membrane module in a water purification system for surface water, wherein when contacting with a NaClO solution having an effective chlorine concentration of 10 to 1000 mg / liter, the effective chlorine concentration and the contact time of the NaClO solution are reduced. And then flush the membrane surface on the raw water side with a transmembrane pressure of 0.3 kg / cm 2 or less, or vice versa. It is intended to provide a method for washing a filtration membrane module, characterized by performing washing. Hereinafter, the present invention will be described in detail.

【0010】本発明による洗浄方法が適用できる濾過膜
モジュールとしては、表流水の水浄化システムに用いら
れる濾過膜モジュールであり、膜形態には中空糸型、プ
レート・アンド・フレーム型、プリーツ型、スパイラル
型、チューブラー(管状)型等が挙げられるが、濾過膜
と薬品との接触後に行う膜表面のフラッシングあるいは
逆洗が最も効果的な中空糸濾過膜モジュールが好まし
い。また濾過膜の材質は特に限定されるものではなく、
高分子材料やセラミック材料等が使用できる。高分子材
料としては、酢酸セルロース、その他のセルロース誘導
体、ポリスルホン系樹脂、ポリアクリロニトリル共重合
体、ポリエチレン、ポリプロピレン、ポリアミド系樹
脂、ポリイミド系樹脂、ポリビニリデンフロライドなど
に適用できる。特に、酢酸セルロースは高濃度の酸およ
び、アルカリ薬剤による耐薬品性に劣るため、本発明に
よる洗浄方法が要求されている。酢酸セルロース膜を本
発明の洗浄方法の対象濾過膜モジュールとして用いる場
合は、化学的耐久性の優れているものとして酢化度が4
0〜62%の範囲にあるもの、好ましくは55〜62%
の範囲のものが適用させる。また、平均重合度は100
〜500の範囲にあるもの、好ましくは150〜350
のものが用いられる。この範囲外の酢酸セルロースを用
いた場合、膜がNaClO水溶液により化学的に劣化す
る可能性があり、また、本発明の洗浄方法を適用するた
めには、洗浄の際のNaClO溶液の接触時間とその濃
度範囲をかなり狭めなければならないため、洗浄の効果
を期待できない結果となる。
The filtration membrane module to which the washing method according to the present invention can be applied is a filtration membrane module used in a water purification system for surface water, and has a hollow fiber type, a plate and frame type, a pleated type, or the like. Spiral type, tubular (tubular) type and the like can be mentioned, but a hollow fiber filtration membrane module in which flushing or backwashing of the membrane surface after contact between the filtration membrane and the chemical is most effective is preferable. The material of the filtration membrane is not particularly limited,
Polymer materials and ceramic materials can be used. Examples of the polymer material include cellulose acetate, other cellulose derivatives, polysulfone resins, polyacrylonitrile copolymers, polyethylene, polypropylene, polyamide resins, polyimide resins, polyvinylidene fluoride, and the like. In particular, cellulose acetate is inferior in chemical resistance due to a high concentration of an acid and an alkaline agent, and thus a cleaning method according to the present invention is required. When a cellulose acetate membrane is used as a filtration membrane module to be subjected to the washing method of the present invention, the degree of acetylation of 4 is considered to be excellent in chemical durability.
Those in the range of 0 to 62%, preferably 55 to 62%
Those in the range are applied. The average degree of polymerization is 100
~ 500, preferably 150-350
Is used. When cellulose acetate outside this range is used, the membrane may be chemically degraded by the NaClO aqueous solution, and in order to apply the cleaning method of the present invention, the contact time of the NaClO solution during cleaning and Since the concentration range has to be considerably narrowed, the effect of cleaning cannot be expected.

【0011】本発明において使用する薬剤としてはNa
ClO溶液を使用するが、NaClOは、本来上水道の
殺菌消毒として使用されている薬剤であり、表流水の水
浄化システムにおける濾過膜モジュールの洗浄剤として
は、人体に与えないという無害性が実証されている。ま
た、NaClO溶液は強い酸化作用を有するため、表流
水の水浄化において濾過膜モジュールを目詰まりさせる
物質のうち、特に有機物質を酸化分解することによって
目詰まり物質を濾過膜モジュールから除去することがで
き、従って、濾過膜モジュールの透水速度が回復できる
と考えられる。本発明で用いるNaClO溶液の有効塩
素濃度は10〜1000mg/リットルが好ましく、よ
り好ましくは50〜500mg/リットルである。ま
た、本発明では、NaClO溶液を濾過膜に接触させて
目詰まり物質を酸化分解するが、このNaClO溶液の
有効塩素濃度と濾過膜への接触時間との積が1000〜
5000(mg/リットル)・hの範囲であることを特
徴としている。すなわち、この積の値が1000(mg
/リットル)・h以下の場合、濾過膜は洗浄剤によって
充分に洗浄できず、濾過膜モジュールの水処理能力を回
復できない。また、積の値が5000(mg/リット
ル)・hより大きい場合には、NaClO溶液による濾
過膜モジュールの劣化を生じてしまう場合がある。従っ
て、この範囲で洗浄することにより充分な洗浄効果が期
待でき、しかも長期にわたり洗浄した場合にも濾過膜モ
ジュール自体の変質なども起こらない。
The drug used in the present invention is Na
Although a ClO solution is used, NaClO is a chemical that is originally used as a disinfectant for waterworks, and as a cleaning agent for a filtration membrane module in a surface water purification system, its harmlessness that it is not given to the human body has been demonstrated. ing. Further, since the NaClO solution has a strong oxidizing effect, it is possible to remove the clogging substance from the filtration membrane module by oxidatively decomposing the organic substance, particularly, of the substances that clog the filtration membrane module in the purification of surface water. It is considered that the water permeation rate of the filtration membrane module can be restored. The effective chlorine concentration of the NaClO solution used in the present invention is preferably from 10 to 1000 mg / liter, more preferably from 50 to 500 mg / liter. Further, in the present invention, the clogging substance is oxidatively decomposed by bringing the NaClO solution into contact with the filtration membrane, and the product of the effective chlorine concentration of the NaClO solution and the contact time with the filtration membrane is 1000 to 1000.
The range is 5000 (mg / liter) · h. That is, the value of this product is 1000 (mg
/ Liter) · h or less, the filtration membrane cannot be sufficiently washed by the detergent, and the water treatment capacity of the filtration membrane module cannot be restored. If the value of the product is greater than 5000 (mg / liter) · h, the NaClO solution may cause deterioration of the filtration membrane module. Therefore, a sufficient washing effect can be expected by washing in this range, and even if the washing is performed for a long period, the filter membrane module itself does not deteriorate.

【0012】本発明においては、濾過膜モジュールをN
aClO溶液に接触させる方法として、流動を与えない
NaClO溶液に濾過膜を静置浸漬して膜目詰まり物質
を酸化分解する方法と、NaClO溶液に流動を与えて
酸化分解に加えて目詰まり物質をはぎ取る方法等が考え
られるが、洗浄方法の簡便性の点から前者(浸漬法)の
方が望ましい。また、浸漬法の場合、濾過膜の透過側に
NaClO溶液を注入して濾過膜を浸し、浸漬後のNa
ClO溶液を回収するという操作を採ると、回収が容易
であるのみならず、原水側のフミン質とNaClO溶液
が反応して発癌性のトリハロメタンが生成するとう危険
性も少なく、より得策である。
In the present invention, the filtration membrane module is
As a method of contacting with the aClO solution, a method of oxidatively decomposing a membrane clogging substance by immersing the filtration membrane in a NaClO solution that does not give a flow, or a method of giving a flow to the NaClO solution to remove the clogging substance by oxidative decomposition. Although a peeling method or the like is conceivable, the former (immersion method) is more preferable from the viewpoint of simplicity of the cleaning method. In the case of the immersion method, a NaClO solution is injected into the permeation side of the filtration membrane to immerse the filtration membrane,
When the operation of recovering the ClO solution is adopted, not only the recovery is easy, but also the danger that the humic substance on the raw water side reacts with the NaClO solution to generate carcinogenic trihalomethane is reduced, which is more advantageous.

【0013】本発明においては、NaClO溶液との接
触後の操作が重要である。即ち、本発明は濾過膜モジュ
ールをNaClO溶液に接触させた後、膜間差圧が0.
3kg/cm2以下で原水の膜表面をフラッシング、あ
るいは、逆洗を行うことを特徴とする。ここでいう膜間
差圧とは、フラッシング時の原水側(1次側)の圧力と
透過側(2次側)の圧力との差を意味する。また、フラ
ッシングとは、流体を原水側膜面方向に流動させ、膜表
面に付着した目詰まり物質を掃流する操作のことであ
る。さらに、逆洗とは流体を透過側から原水側に膜を介
して流通させる操作である。本発明では、フラッシング
時の膜間差圧0.3kg/cm2以下、好ましくは0.
1kg/cm2以下に操作することによって効果的な洗
浄が可能となる。膜間差圧が0.3kg/cm2以上で
フラッシングを行い、流体が原水側から膜を介して大き
く透過する場合、濾過膜モジュールに付着した目詰まり
物質が一旦NaClO溶液の接触によって酸化分解を受
けても、このフラッシングによって分解した目詰まり物
質が再び濾過膜を目詰まりさせるために、結局、濾過膜
モジュールの性能回復ができない。また、フラッシング
に用いる流体は、原水、浄化水、空気およびこれらの混
合流体等がある。フラッシングの時間は特に限定され
ず、濾過の透水速度がある一定レベルに回復するまで行
えばよいが、通常1〜100分程度である。一方、逆洗
を行う場合、流体として膜透過水などの浄化水や空気な
どを用いることができ、逆洗圧力は0.1〜2.0kg
/cm2が望ましい。
In the present invention, the operation after contact with the NaClO solution is important. That is, in the present invention, after the filtration membrane module is brought into contact with the NaClO solution, the transmembrane pressure is reduced to 0.1.
The method is characterized in that the raw water film surface is flushed or backwashed at a pressure of 3 kg / cm 2 or less. The transmembrane pressure here means the difference between the pressure on the raw water side (primary side) and the pressure on the permeation side (secondary side) during flushing. Flushing is an operation in which a fluid is caused to flow in the direction of the raw water-side membrane surface to sweep out clogging substances attached to the membrane surface. Further, backwashing is an operation of flowing a fluid from a permeate side to a raw water side via a membrane. In the present invention, the transmembrane pressure difference at the time of flushing is 0.3 kg / cm 2 or less, preferably 0.1 kg / cm 2 or less.
By controlling the pressure to 1 kg / cm 2 or less, effective cleaning becomes possible. When flushing is performed with a transmembrane pressure difference of 0.3 kg / cm 2 or more, and the fluid largely permeates through the membrane from the raw water side, the clogging substance adhering to the filtration membrane module once undergoes oxidative decomposition by contact with the NaClO solution. Even if it is received, the clogging substances decomposed by the flushing clog the filtration membrane again, so that the performance of the filtration membrane module cannot be recovered after all. Fluids used for flushing include raw water, purified water, air, and a mixed fluid thereof. The flushing time is not particularly limited, and may be performed until the water permeation rate of the filtration recovers to a certain level, and is usually about 1 to 100 minutes. On the other hand, when performing backwashing, purified water such as membrane permeated water or air can be used as the fluid, and the backwashing pressure is 0.1 to 2.0 kg.
/ Cm 2 is desirable.

【0014】本発明による洗浄方法においては、濾過膜
モジュールを水浄化システムから取り外して洗浄するこ
とも、濾過膜モジュールを水浄化システムに装着したま
ま洗浄することも可能である。濾過膜モジュールをシス
テムから取り外す場合には、予め用意したNaClO溶
液に濾過膜を接触させることが好ましい。一方、水浄化
システムに濾過膜モジュールの洗浄用の回路の切り替え
が用意されている場合には、濾過膜モジュールをシステ
ムに装着したまま洗浄することも可能である。なお、洗
浄用の回路とは、通常使用における透過水生成用回路と
は別の、供給原水の代わりにNaClO溶液ならびにす
すぎ用水を供給され、かつ、洗浄による処理廃液を排出
することのできる回路である。また、濾過膜モジュール
4本用の水浄化システムにおいて、予め5本の濾過膜モ
ジュールを設置しておけば、4本の濾過膜モジュールを
運転しながら残り1本の濾過膜モジュールを洗浄するこ
とができ、水浄化システムの運転を休止する必要がなく
なる。
In the cleaning method according to the present invention, the filtration membrane module can be removed from the water purification system for cleaning, or the filtration membrane module can be cleaned while attached to the water purification system. When removing the filtration membrane module from the system, it is preferable to contact the filtration membrane with a previously prepared NaClO solution. On the other hand, when the water purification system is provided with switching of the circuit for cleaning the filtration membrane module, it is possible to perform the cleaning while the filtration membrane module is attached to the system. Note that the washing circuit is a circuit that is different from the permeated water generation circuit in normal use and that can be supplied with a NaClO solution and rinsing water instead of the supply raw water, and can discharge the processing waste liquid due to the washing. is there. Further, in a water purification system for four filtration membrane modules, if five filtration membrane modules are installed in advance, the remaining one filtration membrane module can be washed while operating the four filtration membrane modules. Yes, there is no need to suspend operation of the water purification system.

【0015】本発明におけるNaClOは強力な酸化作
用ならびに分解作用を有し、酸素を放出しながらNaC
lとなる。よって、洗浄による排出処理液としては特別
の処理施設を必要としない。よって、洗浄のための特別
の処理施設なども必要がないため、水浄化システムの現
場において簡便に操作できる。
NaClO in the present invention has a strong oxidizing and decomposing action, and releases NaC while releasing oxygen.
l. Therefore, no special treatment facility is required as the treatment liquid discharged by washing. Therefore, there is no need for a special treatment facility or the like for washing, so that it can be easily operated at the site of the water purification system.

【0016】[0016]

【実施例】以下、実施例により本発明を具体的に説明す
るが、本発明はこれらに限定されるものではない。
EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.

【0017】(実施例1)濾過膜モジュールとして酢酸
セルロース性中空糸膜モジュール(膜面積5m2,有効
膜長さ1m)を用い、図1に示す水浄化システムにおい
て平均濁度7度の河川水で、約100日間濾過運転し
た。このシステムでは原水を中空糸膜の内側に流して濾
過し、30分ごとに1分間、透過水を中空糸膜の外側に
加圧して逆洗を行った。運転後、濾過膜モジュール3中
の任意の位置の中空糸膜(約1m)を取り出し、本発明
による洗浄回復性を試験する試料とした。この試料中空
糸膜の長さ50cmを膜中に気泡が入らないように注意
して有効塩素濃度500mg/リットルのNaClO水
溶液中に3時間静置浸漬した。この際のNaClO水溶
液の有効塩素濃度と溶液中の膜の接触時間の積は150
0(mg/リットル)・hである。
(Example 1) A cellulose acetate hollow fiber membrane module (membrane area 5 m 2 , effective membrane length 1 m) was used as a filtration membrane module, and river water having an average turbidity of 7 ° C was used in the water purification system shown in FIG. For about 100 days. In this system, raw water was passed through the inside of the hollow fiber membrane and filtered, and backwashing was performed by pressing permeated water to the outside of the hollow fiber membrane every 30 minutes for 1 minute. After the operation, the hollow fiber membrane (approximately 1 m) at an arbitrary position in the filtration membrane module 3 was taken out and used as a sample for testing the washing recovery property according to the present invention. The sample hollow fiber membrane having a length of 50 cm was immersed in a NaClO aqueous solution having an effective chlorine concentration of 500 mg / liter for 3 hours while taking care not to allow air bubbles to enter the membrane. At this time, the product of the effective chlorine concentration of the NaClO aqueous solution and the contact time of the film in the solution is 150.
0 (mg / liter) · h.

【0018】浸漬後の中空糸膜の膜内部の一端からイオ
ン交換水を膜間差圧0.05kg/cm2で100ミリ
リットル流し、内表面に付着していた目詰まり物質を掃
流した。この時、中空糸膜のもう一端は開放してある状
態である。以上のようにして洗浄した中空糸膜の洗浄回
復性能を、純水透過速度(PWP)を測定して求めた。
ここでPWPとは、有効長50cmの中空糸膜の内側に
25℃の純水で1kg/cm2の水圧をかけ、単位膜面
積・単位時間当たりの透過した純水の量をいう。洗浄後
の中空糸膜のPWPは410リットル/m2・h(kg
/cm2)であり、これは濾過に使用する前の中空糸膜
の450リットル/m2・h(kg/cm2)の90%の
洗浄回復率(下式(1))を示した。表−1にNaCl
O溶液との接触後の洗浄操作(「接触後の操作」と記
す)洗浄方法と洗浄回復率を示した。なお洗浄前の中空
糸膜のPWPは100リットル/m2・h(kg/c
2)であり、濾過運転後の中空糸膜のフラックス低下
率(下式(2))は22%であった。また、本洗浄操作
によって膜付着物の著しい流出が観察された。
Ion-exchanged water (100 ml) was flowed from one end of the hollow fiber membrane after immersion at a transmembrane pressure difference of 0.05 kg / cm 2 , and the clogging substance adhering to the inner surface was swept away. At this time, the other end of the hollow fiber membrane is open. The cleaning recovery performance of the hollow fiber membrane washed as described above was determined by measuring the pure water permeation rate (PWP).
Here, PWP refers to the amount of pure water permeated per unit membrane area and unit time by applying a water pressure of 1 kg / cm 2 with pure water at 25 ° C. inside a hollow fiber membrane having an effective length of 50 cm. The PWP of the hollow fiber membrane after washing is 410 liter / m 2 · h (kg
/ Cm 2 ), indicating a 90% washing recovery rate (the following formula (1)) of 450 l / m 2 · h (kg / cm 2 ) of the hollow fiber membrane before use for filtration. Table 1 shows NaCl
The washing operation after contact with the O solution (hereinafter referred to as "operation after contact") and the washing recovery rate are shown. The PWP of the hollow fiber membrane before washing was 100 l / m 2 · h (kg / c
m 2 ), and the flux reduction rate of the hollow fiber membrane after the filtration operation (the following formula (2)) was 22%. In addition, remarkable outflow of film deposits was observed by this cleaning operation.

【0019】[0019]

【数1】 洗浄回復率(%)=(洗浄後PWP/使用前PWP)×100 (1 ) 洗浄前PWP低下率(%)=(使用後PWP/使用前PWP)×100 (2 )## EQU1 ## Cleaning recovery rate (%) = (PWP after cleaning / PWP before use) × 100 (1) PWP reduction rate before cleaning (%) = (PWP after use / PWP before use) × 100 (2)

【0020】(実例例2)実例例1と同様に水浄化シス
テムによって河川水を約100日間濾過した後の酢酸セ
ルロース中空糸膜モジュールを水浄化システムから取り
出し、この濾過膜モジュール3の入口および出口の両原
水ポート部分を閉じた。次いで中空糸膜モジュール3の
透過側ケーシング内の透過水を取り除き、有効塩素濃度
100mg/リットルのNaClO水溶液が中空糸膜の
外表面に接触するようにケーシング内部に充填した。接
触時間が18時間後にケーシング内のNaClO水溶液
を除き、中空糸膜モジュールを再び水浄化システムに装
着した。その後、膜透過水を逆洗圧力0.5kg/cm
2で中空糸膜の外表面から透過して1分間逆洗を行い、
中空糸膜内表面の付着物を流し出した。次いで、濾過運
転を再開し、濾過初期の透水流速を測定し、次式(3)
によって洗浄回復率を求め、表−1に示した。 洗浄回復率(%)=(初期透水流速/使用前PWP)×100 (3)
(Example 2) As in Example 1, the cellulose acetate hollow fiber membrane module after the river water was filtered for about 100 days by the water purification system was taken out of the water purification system, and the inlet and outlet of the filtration membrane module 3 were removed. Closed both raw water ports. Next, the permeated water in the permeation-side casing of the hollow fiber membrane module 3 was removed, and an aqueous NaClO solution having an effective chlorine concentration of 100 mg / liter was filled into the casing so as to contact the outer surface of the hollow fiber membrane. After a contact time of 18 hours, the aqueous NaClO solution in the casing was removed, and the hollow fiber membrane module was mounted again on the water purification system. Then, the membrane permeated water is backwashed at a pressure of 0.5 kg / cm.
In step 2 , permeate from the outer surface of the hollow fiber membrane and backwash for 1 minute.
Deposits on the inner surface of the hollow fiber membrane were drained out. Next, the filtration operation was restarted, and the water permeation flow rate at the initial stage of the filtration was measured.
The cleaning recovery rate was determined by the above, and is shown in Table 1. Washing recovery rate (%) = (initial water permeation flow rate / PWP before use) × 100 (3)

【0021】(実例例3)実例例2と同様にして濾過し
た後の酢酸セルロース中空糸膜モジュールを実施例2と
同様に中空糸膜の外表面に有効塩素濃度100mg/リ
ットルのNaClO水溶液を18時間接触させ、水浄化
システムに濾過膜モジュールを装着した。その後、透過
側のポートを閉じて膜間差圧がゼロの状態でモジュール
の入口圧が1.0kg/cm2で中空糸膜表面を1分間
掃流した。実施例2と同様に洗浄回復率を求め、表−1
に示した。
Example 3 A cellulose acetate hollow fiber membrane module after filtration in the same manner as in Example 2 was treated with 18 ml of an aqueous NaClO solution having an effective chlorine concentration of 100 mg / liter on the outer surface of the hollow fiber membrane in the same manner as in Example 2. After contacting for a period of time, the water purification system was equipped with a filtration membrane module. Thereafter, the port on the permeation side was closed, and the membrane pressure was zero, and the hollow fiber membrane surface was purged for 1 minute at an inlet pressure of the module of 1.0 kg / cm 2 . The cleaning recovery rate was determined in the same manner as in Example 2, and Table 1
It was shown to.

【0022】(比較例1)実施例1と同様の水浄化シス
テムで使用した中空糸膜を有効塩素濃度500mg/リ
ットルのNaClO水溶液に静置浸漬した。浸漬3時間
後に中空糸膜を取り出し、膜間差圧1.0kg/cm2
でイオン交換水を100ミリリットル流し、中空糸膜内
表面を掃流した。その後、PWPを測定し洗浄回復率を
求めた。その結果を表−1に示す。
Comparative Example 1 A hollow fiber membrane used in the same water purification system as in Example 1 was immersed in a NaClO aqueous solution having an effective chlorine concentration of 500 mg / liter. After 3 hours of immersion, the hollow fiber membrane was taken out, and the transmembrane pressure difference was 1.0 kg / cm 2.
Then, 100 ml of ion-exchanged water was flowed to sweep the inner surface of the hollow fiber membrane. Thereafter, the PWP was measured to determine the cleaning recovery rate. Table 1 shows the results.

【0023】(比較例2)実施例1と同様の水浄化シス
テムにおいて使用した中空糸膜を有効塩素濃度500m
g/リットルのNaClO水溶液に50時間静置浸漬し
た。その後、実施例1と同様に膜間差圧0.05kg/
cm2でイオン交換水を100ミリリットル流し、中空
糸膜内表面を掃流した。その後、PWPを測定し洗浄回
復率を求めた。その結果を表−1に示す。
(Comparative Example 2) A hollow fiber membrane used in the same water purification system as in Example 1 was prepared using an effective chlorine concentration of 500 m.
It was immersed in a g / L NaClO aqueous solution for 50 hours. Then, as in Example 1, the transmembrane pressure difference was 0.05 kg /
100 ml of ion-exchanged water was flowed in cm 2 to sweep the inner surface of the hollow fiber membrane. Thereafter, the PWP was measured to determine the cleaning recovery rate. Table 1 shows the results.

【0024】[0024]

【表1】 [Table 1]

【0025】[0025]

【発明の効果】本発明の洗浄方法によれば、濾過膜モジ
ュールの特別な管理を要することなく水処理能の回復を
行うことができる。しかも水処理システムを休止するこ
となく連続運転しながら洗浄することも可能となる。さ
らに、NaClOは強アルカリ、強酸あるいは界面活性
剤などと異なり中和やその他の後処理が不要であり、水
浄化処理場において簡便に使用できる。
According to the cleaning method of the present invention, the water treatment capacity can be restored without requiring special management of the filtration membrane module. In addition, washing can be performed while the water treatment system is continuously operated without stopping. Furthermore, NaClO does not require neutralization or other post-treatments unlike strong alkalis, strong acids or surfactants, and can be used easily in water purification plants.

【0026】[0026]

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明の評価で用いた水浄化システムFIG. 1 is a water purification system used in the evaluation of the present invention.

【符号の説明】[Explanation of symbols]

1 逆止弁 2 ポンプ 3 中空糸膜モジュール 4 透過水自動弁 5 洗浄水排出自動弁 6 洗浄水排出経路 7 循環経路 8 透過水タンク 9 ポンプ 10 逆洗自動弁 DESCRIPTION OF SYMBOLS 1 Check valve 2 Pump 3 Hollow fiber membrane module 4 Automatic permeated water valve 5 Automatic washing water discharge valve 6 Washing water discharge path 7 Circulation path 8 Permeated water tank 9 Pump 10 Automatic backwashing valve

───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭60−220709(JP,A) 特開 昭57−71607(JP,A) 特開 平6−238135(JP,A) 特開 平6−238136(JP,A) 特開 平8−52330(JP,A) 特開 平7−136474(JP,A) 実開 平1−92202(JP,U) (58)調査した分野(Int.Cl.7,DB名) B01D 65/06 B01D 65/02 B01D 71/16 C02F 1/44 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-220709 (JP, A) JP-A-57-71607 (JP, A) JP-A-6-238135 (JP, A) JP-A-6-238135 238136 (JP, A) JP-A-8-52330 (JP, A) JP-A-7-136474 (JP, A) JP-A-1-92202 (JP, U) (58) Fields studied (Int. Cl. 7 , DB name) B01D 65/06 B01D 65/02 B01D 71/16 C02F 1/44

Claims (3)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】 表流水の水浄化システムにおける濾過膜
モジュールの洗浄方法において、有効塩素濃度10〜1
000mg/リットルの次亜塩素酸ナトリウム(NaC
lO)溶液に濾過膜モジュールを接触させる際、該Na
ClO溶液の有効塩素濃度と接触時間との積が1000
〜5000(mg/リットル)・hの範囲になるよう接
触させた後、原水側の膜表面を膜間差圧が0.3kg/
cm2以下でフラッシングするか、あるいは、逆洗を行
うことを特徴とする濾過膜モジュールの洗浄方法。
1. A method for cleaning a filtration membrane module in a surface water purification system, comprising the steps of:
000mg / L sodium hypochlorite (NaC
10) When contacting the filtration membrane module with the solution,
The product of the effective chlorine concentration of the ClO solution and the contact time is 1000
~ 5000 (mg / liter) · h, and the membrane pressure on the raw water side was 0.3 kg /
A method for cleaning a filtration membrane module, comprising flushing or backwashing at a density of not more than cm 2 .
【請求項2】 請求項1記載の濾過膜モジュールの膜材
質が酢酸セルロースであることを特徴とする濾過膜モジ
ュールの洗浄方法。
2. The method for cleaning a filtration membrane module according to claim 1, wherein the membrane material of the filtration membrane module is cellulose acetate.
【請求項3】 2本以上の濾過膜モジュールからなる水
処理システムにおいて、少なくとも1本の濾過膜モジュ
ールを使用しながら他の濾過膜モジュールを水処理シス
テムに装着したまま洗浄することを特徴とする請求項1
記載の濾過膜モジュールの洗浄方法。
3. A water treatment system comprising two or more filtration membrane modules, wherein at least one filtration membrane module is used while another filtration membrane module is washed while being attached to the water treatment system. Claim 1
A method for cleaning a filtration membrane module according to the above.
JP31130494A 1994-11-22 1994-11-22 Cleaning method for filtration membrane module Expired - Fee Related JP3194679B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP31130494A JP3194679B2 (en) 1994-11-22 1994-11-22 Cleaning method for filtration membrane module

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP31130494A JP3194679B2 (en) 1994-11-22 1994-11-22 Cleaning method for filtration membrane module

Publications (2)

Publication Number Publication Date
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JP3194679B2 true JP3194679B2 (en) 2001-07-30

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ID=18015531

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US6190557B1 (en) 1996-12-09 2001-02-20 Nitto Denko Corporation Spiral wound type membrane element, running method and washing method thereof
CN101058446A (en) * 2003-07-08 2007-10-24 三菱丽阳株式会社 Method of cleaning water purifier
JP4498854B2 (en) * 2004-08-17 2010-07-07 ダイセル化学工業株式会社 Operation method of water purification system
JP4804176B2 (en) * 2006-03-06 2011-11-02 ダイセン・メンブレン・システムズ株式会社 Seawater filtration
WO2012036003A1 (en) 2010-09-14 2012-03-22 東レ株式会社 Production method for chemicals by continuous fermentation
CN103492054B (en) * 2011-04-25 2015-06-03 东丽株式会社 Method for cleaning membrane module

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JPS5771607A (en) * 1980-10-23 1982-05-04 Sumitomo Metal Ind Ltd Cleaning of osmotic membrane
JPS60220709A (en) * 1984-04-17 1985-11-05 日本ヒユ−ム管株式会社 Composite concrete product
JPH0192202U (en) * 1987-12-08 1989-06-16
JPH06238135A (en) * 1993-02-17 1994-08-30 Daicel Chem Ind Ltd Permeated flux recovery method for hollow fiber filter membrane module
JP3359687B2 (en) * 1993-02-17 2002-12-24 ダイセル化学工業株式会社 Cleaning method for filtration membrane module

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104528884A (en) * 2015-01-07 2015-04-22 河北昊源环境工程有限公司 Membrane ultrasonic and synchronous incrustation removal ultrafiltration device and control method thereof

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