JPH08141375A - Cleaning method for filtration film module - Google Patents
Cleaning method for filtration film moduleInfo
- Publication number
- JPH08141375A JPH08141375A JP6311304A JP31130494A JPH08141375A JP H08141375 A JPH08141375 A JP H08141375A JP 6311304 A JP6311304 A JP 6311304A JP 31130494 A JP31130494 A JP 31130494A JP H08141375 A JPH08141375 A JP H08141375A
- Authority
- JP
- Japan
- Prior art keywords
- filtration membrane
- water
- membrane module
- 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.)
- Granted
Links
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
Description
【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 specifically, it attaches to a filtration membrane by contacting the filtration membrane with a specific chemical and then performing flushing or backwashing operation. The present invention relates to a method for cleaning a filtration membrane module, which removes the water-insoluble unpermeated substance and restores 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 Recently, a water purification system to which a membrane separation technique is applied has been attracting attention as a new method replacing the conventional method of coagulation-precipitation-sand filtration-chlorine sterilization. As a water purification system using a separation membrane, there is cross-flow filtration, and various trials have been made because it is more resistant to fluctuations in raw water turbidity than full-scale filtration. Here, cross-flow filtration means that raw water is supplied to one membrane surface (raw water supply side separation membrane surface) of the separation membrane, and permeated water that has permeated through the separation membrane is passed to the other membrane surface (permeated water side separation membrane). Surface), by collecting the raw water in parallel with the surface of the separation membrane on the raw water supply side,
It refers to a filtration method which has an effect of stripping off suspended matter contained in raw water adhering to the surface of a separation membrane from the surface of the membrane. However, even by this cross-flow filtration, the suspended substances contained in the raw water are laminated on the surface of the separation membrane due to the passage of 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。Since this clogging causes an interruption of the operation of the water purification system, in order to eliminate or prevent the clogging, backwashing (hereinafter referred to as backwashing) is generally performed.
Has been done. However, even when backwashing with a low-concentration sodium hypochlorite (NaClO) solution and cross-flow filtration are alternately performed, non-permeable substances that cannot be gradually removed during continuous operation for a long period of time are formed on the membrane surface and inside the membrane. Accumulated in
Water treatment capacity decreases. Therefore, once every few months, a method of recovering the water treatment capacity of the filtration membrane module by treating the filtration membrane module with a chemical to remove the non-permeable substance adhering to the surface of the filtration membrane module, etc. is 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 toxic and does not adversely affect the subsequent filtration processing operation, and that the filtration membrane performance is not deteriorated. It is desirable to quickly and completely remove the non-permeable substance from the filtration membrane with the above chemicals and 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。Chemicals used for cleaning the filtration membrane module include surfactants, acids and alkaline enzymes. However, in the case of cleaning the filtration membrane module used to purify surface water, for example, if a detergent or enzyme-containing detergent is used, the filtration membrane module after cleaning is thoroughly rinsed with permeated water, etc. Unless the drug inside is completely removed, the final product, clean water, will adversely affect the human body. In addition to the great difficulty of removing such used chemicals from the filtration membrane module, a large amount of washing water is generated, and the treatment of the washing waste water requires a cost. On the other hand, when acid or alkali is used, use of these high-concentration chemicals is required.
This causes damage to the filtration membrane module itself, and it is difficult to set cleaning conditions. Furthermore, post-treatment such as neutralization of used wastewater is also required, which leads to an increase in wastewater treatment cost as in the case of using a surfactant or the like. Therefore, in cleaning the filtration membrane module for purifying surface water, the chemicals are not harmful, and there is no deterioration effect on the filtration membrane module itself, which has stable and effective cleaning power, and is simple and easy. 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。As such a cleaning method, Japanese Laid-Open Patent Publication No. 5-1
Japanese Patent No. 03958 discloses cleaning of a membrane module used for coagulation separation of organic wastewater using citric acid and NaClO. First, the membrane is circulated and washed with an aqueous citric acid solution adjusted to pH 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 a NaClO aqueous solution containing 200 mg / liter of available chlorine. Then, the cleaning method is to immerse the film in the same liquid. But,
When a NaClO solution is used as a cleaning agent, an organic substance such as humic substance in raw water may react with NaClO, and a carcinogen trihalomethane 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。[0007] Japanese Patent Application No. 5-308589 discloses a method for cleaning a filtration membrane module, which has a concentration of 5 to 95 mg.
The filtration membrane module is dipped in 1 / l of NaClO solution, and 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 cleaning operation by immersion using a NaClO solution,
If the washing operation after immersion in chemicals is inappropriate, the filtration membrane will not be sufficiently washed and the water permeability of the filtration membrane will not be 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 As a result of intensive investigations by the present inventors in order to overcome the above-mentioned problems, as a result of using a NaClO solution having a specific concentration as a cleaning method for a filtration membrane module, an operation after cleaning is performed. The inventors have found that the function is restored without damaging the material of the filtration membrane module, the post-treatment of waste water is not required, and the management is simple, and the present invention has been 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, according to the present invention, in the method for cleaning a filtration membrane module in a surface water purification system, when contacting a NaClO solution having an effective chlorine concentration of 10 to 1000 mg / liter, the effective chlorine concentration of the NaClO solution and the contact time are After contacting so that the product of 1000 to 5000 (mg / liter) · h is reached, the membrane pressure on the raw water side is flushed with a transmembrane pressure difference of 0.3 kg / cm 2 or less, or vice versa. The present invention provides a method for cleaning a filtration membrane module, which is characterized by performing cleaning. The present invention will be described in detail below.
【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 cleaning method according to the present invention can be applied is a filtration membrane module used in a water purification system of surface water, and the membrane forms are hollow fiber type, plate and frame type, pleated type, Examples thereof include a spiral type and a tubular type, and a hollow fiber filtration membrane module is most effective in flushing or backwashing the membrane surface after contacting the filtration membrane with a chemical. The material of the filtration membrane is not particularly limited,
Polymer materials and ceramic materials can be used. As the polymer material, cellulose acetate, other cellulose derivatives, polysulfone-based resins, polyacrylonitrile copolymers, polyethylene, polypropylene, polyamide-based resins, polyimide-based resins, polyvinylidene fluoride, etc. can be used. In particular, cellulose acetate is inferior in chemical resistance due to high concentration of acid and alkaline chemicals, and therefore the cleaning method according to the present invention is required. When the cellulose acetate membrane is used as the target filtration membrane module of the cleaning method of the present invention, the degree of acetylation is 4 because it has excellent chemical durability.
Those in the range of 0 to 62%, preferably 55 to 62%
The thing of the range of applies. The average degree of polymerization is 100.
~ 500, preferably 150-350
What is used. When cellulose acetate outside this range is used, the membrane may be chemically deteriorated 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 must be narrowed considerably, 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 sterilizing and disinfecting waterworks, and it has been proved that it is harmless to humans as a cleaning agent for filtration membrane modules in surface water purification systems. ing. Further, since the NaClO solution has a strong oxidizing action, it is possible to remove the clogging substance from the filtration membrane module by oxidatively decomposing an organic substance among substances that clogging the filtration membrane module in the purification of surface water. It is considered that the water permeability of the filtration membrane module can be recovered. The effective chlorine concentration of the NaClO solution used in the present invention is preferably 10 to 1000 mg / liter, more preferably 50 to 500 mg / liter. Further, in the present invention, the NaClO solution is brought into contact with the filter membrane to oxidize and decompose the clogged substance, and the product of the effective chlorine concentration of this NaClO solution and the contact time with the filter membrane is 1000 to 1000.
It is characterized in that it is in the range of 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 with the detergent, and the water treatment capacity of the filtration membrane module cannot be recovered. Further, when the product value is larger than 5000 (mg / liter) · h, the NaClO solution may cause deterioration of the filtration membrane module. Therefore, by washing in this range, a sufficient washing effect can be expected, and even if the washing is performed for a long period of time, deterioration of the filtration membrane module itself does not occur.
【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 the method of contacting with the aClO solution, the filtration membrane is left to immerse in a NaClO solution that does not give a flow to oxidize and decompose the membrane clogging substance, and a flow to the NaClO solution is given to oxidize and decompose the clogging substance. Although a stripping method or the like can be considered, the former (immersion method) is preferable from the viewpoint of the convenience of the cleaning method. In the case of the dipping method, a NaClO solution is injected into the permeate side of the filtration membrane to immerse the filtration membrane, and
If the operation of recovering the ClO solution is adopted, not only the recovery is easy, but also the risk that a humic substance on the raw water side reacts with the NaClO solution to generate a carcinogenic trihalomethane, which is a better strategy.
【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, according to the present invention, after contacting the filtration membrane module with the NaClO solution, the transmembrane pressure difference becomes 0.
It is characterized in that the surface of the raw water film is flushed or backwashed at 3 kg / cm 2 or less. The transmembrane pressure difference referred to 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 of flowing a fluid in the direction of the membrane surface on the raw water side to sweep away the clogging substances adhering to the membrane surface. Further, backwashing is an operation in which the fluid is passed from the permeate side to the raw water side through the membrane. In the present invention, the transmembrane pressure difference during flushing is 0.3 kg / cm 2 or less, preferably 0.
By operating at 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 when the fluid largely permeates from the raw water side through the membrane, the clogging substance attached to the filtration membrane module once undergoes oxidative decomposition by contact with the NaClO solution. Even if received, the clogging substance decomposed by the flushing again clogs the filtration membrane, and eventually the performance of the filtration membrane module cannot be recovered. Fluids used for flushing include raw water, purified water, air, and mixed fluids thereof. The flushing time is not particularly limited, and may be performed until the water permeation rate of filtration is restored to a certain level, but it is usually about 1 to 100 minutes. On the other hand, when backwashing, purified water such as membrane permeate 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, it is possible to remove the filtration membrane module from the water purification system for washing, or to carry out the washing while the filtration membrane module is mounted in the water purification system. When the filtration membrane module is removed from the system, it is preferable to bring the filtration membrane into contact with a previously prepared NaClO solution. On the other hand, when the water purification system is provided with a switching circuit for cleaning the filtration membrane module, it is possible to perform the cleaning while the filtration membrane module is mounted in the system. Note that the circuit for cleaning is a circuit different from the circuit for generating permeated water in normal use, which is supplied with a NaClO solution and rinsing water instead of the supply raw water, and is capable of discharging the treatment waste liquid by cleaning. is there. In addition, in the 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. This eliminates the need to suspend the 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。The NaClO in the present invention has a strong oxidizing action and a decomposing action and emits oxygen while releasing NaC.
It becomes l. Therefore, no special treatment facility is required for the treatment liquid discharged by cleaning. Therefore, there is no need for a special treatment facility for cleaning, so that the operation can be performed easily 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 in detail with reference to examples, but the present invention is not limited thereto.
【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 degrees was used in the water purification system shown in FIG. Then, the filtration operation was performed for about 100 days. In this system, raw water was flown inside the hollow fiber membranes to be filtered, and permeate was pressurized to the outside of the hollow fiber membranes every 30 minutes for backwashing. After the operation, the hollow fiber membrane (about 1 m) at an arbitrary position in the filtration membrane module 3 was taken out and used as a sample to be tested for washing recovery according to the present invention. The sample hollow fiber membrane having a length of 50 cm was immersed in an aqueous solution of NaClO having an effective chlorine concentration of 500 mg / liter for 3 hours while being careful not to allow 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.
It is 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
ｍ2）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。100 ml of ion-exchanged water was caused to flow from one end inside the hollow fiber membrane after the immersion at a transmembrane pressure difference of 0.05 kg / cm 2 to sweep away the clogging substances adhering to the inner surface. At this time, the other end of the hollow fiber membrane is in an open state. The wash recovery performance of the hollow fiber membrane washed as described above was determined by measuring the pure water permeation rate (PWP).
Here, PWP means the amount of pure water per unit membrane area and unit time when a pressure of 1 kg / cm 2 of pure water at 25 ° C. is applied to the inside of a hollow fiber membrane having an effective length of 50 cm. The PWP of the hollow fiber membrane after washing is 410 liters / m 2 · h (kg
/ Cm 2 ), which showed a 90% washing recovery rate (following formula (1)) of 450 liter / m 2 · h (kg / cm 2 ) of the hollow fiber membrane before being used for filtration. Table-1 shows NaCl
The cleaning method after the contact with the O solution (hereinafter referred to as "operation after contact") and the cleaning recovery rate are shown. The PWP of the hollow fiber membrane before washing is 100 liter / m 2 · h (kg / c
m 2 ), and the flux reduction rate (following formula (2)) of the hollow fiber membrane after the filtration operation was 22%. In addition, a significant outflow of the film deposit was observed by the main washing 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 ）[Equation 1] Cleaning recovery rate (%) = (PWP after cleaning / PWP before use) × 100 (1) PWP decrease 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 filtering the river water by the water purification system for about 100 days was taken out from the water purification system, and the inlet and outlet of this filtration membrane module 3 were removed. Both raw water ports were closed. Then, the permeated water in the permeation side casing of the hollow fiber membrane module 3 was removed, and a NaClO aqueous solution having an effective chlorine concentration of 100 mg / liter was filled inside the casing so as to come into contact with the outer surface of the hollow fiber membrane. After 18 hours of contact time, the aqueous NaClO solution in the casing was removed, and the hollow fiber membrane module was attached to the water purification system again. After that, the back-wash pressure of the membrane-permeated water is 0.5 kg / cm.
In step 2 , permeate from the outer surface of the hollow fiber membrane and back wash for 1 minute.
The deposit on the inner surface of the hollow fiber membrane was poured out. Then, the filtration operation is restarted, and the permeation flow velocity at the initial stage of filtration is measured, and the following equation (3)
The cleaning recovery rate was determined by Table 1 and shown in Table 1. Cleaning recovery rate (%) = (initial water flow rate / PWP before use) x 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 The cellulose acetate hollow fiber membrane module after filtering in the same manner as in Example 2 was subjected to the same procedure as in Example 2 except that 18 mL of an aqueous solution of NaClO having an effective chlorine concentration of 100 mg / liter was applied to the outer surface of the hollow fiber membrane. After contacting for a time, the water purification system was equipped with a filtration membrane module. After that, the port on the permeate side was closed, and the hollow fiber membrane surface was swept for 1 minute at a module inlet pressure of 1.0 kg / cm 2 with the transmembrane pressure difference being zero. The cleaning recovery rate was calculated 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) The hollow fiber membrane used in the same water purification system as in Example 1 was allowed to stand and immerse in a NaClO aqueous solution having an effective chlorine concentration of 500 mg / liter. The hollow fiber membrane was taken out 3 hours after the immersion, 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. Then, the PWP was measured to obtain the cleaning recovery rate. The results are shown in Table-1.
【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 treated with an effective chlorine concentration of 500 m.
It was dipped in a g / l aqueous solution of NaClO for 50 hours. Then, as in Example 1, transmembrane pressure difference of 0.05 kg /
100 ml of ion-exchanged water was caused to flow in cm 2 , and the inner surface of the hollow fiber membrane was swept. Then, the PWP was measured to obtain the cleaning recovery rate. The results are shown in Table-1.
【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 recovered without requiring special management of the filtration membrane module. Moreover, it is possible to perform the washing while continuously operating the water treatment system without stopping. Furthermore, unlike strong alkalis, strong acids, or surfactants, NaClO does not require neutralization or other post-treatments, and can be conveniently used in water purification plants.
【００２６】[0026]
【図１】本発明の評価で用いた水浄化システムFIG. 1 Water purification system used in the evaluation of the present invention
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 1 Check Valve 2 Pump 3 Hollow Fiber Membrane Module 4 Automatic Permeate Water Valve 5 Automatic Wash Water Discharge Valve 6 Cleaning Water Discharge Route 7 Circulation Path 8 Permeate Tank 9 Pump 10 Reverse Wash Automatic Valve
Claims (3)
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, wherein the effective chlorine concentration is 10 to 1
000mg / l sodium hypochlorite (NaC
10) when contacting the filtration membrane module with the Na
The product of the effective chlorine concentration of the ClO solution and the contact time is 1000
~ 5000 (mg / liter) · h after contacting so as to be in the range, the transmembrane pressure on the raw water side is 0.3 kg /
A method for cleaning a filtration membrane module, which comprises performing flushing at a cm 2 or less or performing backwashing.
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.
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 and another filtration membrane module is washed while being mounted in the water treatment system. Claim 1
A method for cleaning a filtration membrane module as described above.
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 |
|---|---|
| JPH08141375A true JPH08141375A (en) | 1996-06-04 |
| JP3194679B2 JP3194679B2 (en) | 2001-07-30 |
Family
ID=18015531
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31130494A Expired - Fee Related JP3194679B2 (en) | 1994-11-22 | 1994-11-22 | Cleaning method for filtration membrane module |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3194679B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6190557B1 (en) | 1996-12-09 | 2001-02-20 | Nitto Denko Corporation | Spiral wound type membrane element, running method and washing method thereof |
| WO2005003038A1 (en) * | 2003-07-08 | 2005-01-13 | Mitsubishi Rayon Co., Ltd. | Water purifier and method of cleaning the same |
| JP2006055680A (en) * | 2004-08-17 | 2006-03-02 | Daicel Chem Ind Ltd | Operation method for water cleaning system |
| JP2007237016A (en) * | 2006-03-06 | 2007-09-20 | Daicen Membrane Systems Ltd | Seawater filtering method |
| WO2012036003A1 (en) | 2010-09-14 | 2012-03-22 | 東レ株式会社 | Production method for chemicals by continuous fermentation |
| JP6003646B2 (en) * | 2011-04-25 | 2016-10-05 | 東レ株式会社 | Membrane module cleaning method |
Families Citing this family (1)
| 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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| JPH0192202U (en) * | 1987-12-08 | 1989-06-16 | ||
| JPH06238136A (en) * | 1993-02-17 | 1994-08-30 | Daicel Chem Ind Ltd | Method for washing filter membrane module |
| JPH06238135A (en) * | 1993-02-17 | 1994-08-30 | Daicel Chem Ind Ltd | Permeated flux recovery method for hollow fiber filter membrane module |
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1994
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 | ||
| JPH06238136A (en) * | 1993-02-17 | 1994-08-30 | Daicel Chem Ind Ltd | Method for washing filter membrane module |
| JPH06238135A (en) * | 1993-02-17 | 1994-08-30 | Daicel Chem Ind Ltd | Permeated flux recovery method for hollow fiber filter membrane module |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6190557B1 (en) | 1996-12-09 | 2001-02-20 | Nitto Denko Corporation | Spiral wound type membrane element, running method and washing method thereof |
| WO2005003038A1 (en) * | 2003-07-08 | 2005-01-13 | Mitsubishi Rayon Co., Ltd. | Water purifier and method of cleaning the same |
| JPWO2005003038A1 (en) * | 2003-07-08 | 2006-08-10 | 三菱レイヨン株式会社 | Water purifier and cleaning method thereof |
| CN100347097C (en) * | 2003-07-08 | 2007-11-07 | 三菱丽阳株式会社 | Water purifier and method of cleaning the same |
| JP2006055680A (en) * | 2004-08-17 | 2006-03-02 | Daicel Chem Ind Ltd | Operation method for water cleaning system |
| 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 |
| JP2007237016A (en) * | 2006-03-06 | 2007-09-20 | Daicen Membrane Systems Ltd | Seawater filtering method |
| WO2012036003A1 (en) | 2010-09-14 | 2012-03-22 | 東レ株式会社 | Production method for chemicals by continuous fermentation |
| JP6003646B2 (en) * | 2011-04-25 | 2016-10-05 | 東レ株式会社 | Membrane module cleaning method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3194679B2 (en) | 2001-07-30 |
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