JP2004049977A

JP2004049977A - Refined water making method by reverse osmosis module and refined water making apparatus employing the method

Info

Publication number: JP2004049977A
Application number: JP2002208199A
Authority: JP
Inventors: Akihiko Sugimoto; 杉本　章彦; Mitsuyoshi Okamoto; 岡本　光好
Original assignee: Toray Medical Co Ltd
Current assignee: Toray Medical Co Ltd
Priority date: 2002-07-17
Filing date: 2002-07-17
Publication date: 2004-02-19
Anticipated expiration: 2022-07-17
Also published as: JP4296534B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refined water making method due to a reverse osmosis membrane module having a sterilization and disinfection function for keeping refined water cleanness and excellent in operability, ecconomical efficiency and safety, and a refined water making apparatus. <P>SOLUTION: In the refined water making method for feeding pretreated raw water, which is treated in a pretreatment part for removing residual chlorine in raw water, to the reverse osmosis membrane module under pressure and separating the same into refined water and concentrated water by a reverse osmosis membrane, a heating device for making high temperature water with a temperature of 60 to <75°C is provided and the high temprature water made by the heating device is supplied to the membrane separation module part. Further, branch pipelines communicating with the refined water pipeline and concentrated water pipeline of the membrane separation module part through the heating device are provided and the high temperature water supplied to the membrane separation module part is recovered/circulated to the heating device through the branch pipelines to disinfect the reverse osmosis membrane module. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、逆浸透膜モジュール式の精製水製造方法と製造装置に関する。
【０００２】
さらに詳しくは、医療分野において、洗浄、配合、希釈用途に使用される純水あるいは純水に近い精製水、特には細菌やエンドトキシンによる汚染が実質的にない状態で透析装置に供給する精製水の製造が可能な逆浸透膜モジュール式の精製水製造方法と製造装置に関する。
【０００３】
【従来の技術】
現在、逆浸透膜式精製水製造装置で使用される逆浸透膜は、特に医療分野では、その使用環境から低圧運転で透過水量が多く、塩排除率の高い架橋ポリアミド複合膜が多用されている。しかし、該逆浸透膜の膜表面緻密層は約０．２μｍ程度の厚みであり、原水中に残留塩素が含まれていると経時塩素劣化を引き起こし塩排除率低下などの性能低下に至る。
【０００４】
従来、一般的な逆浸透膜モジュール式の精製水の製造装置は、図１に示す通り、前処理部１、加圧部２、膜分離部３で構成され、それぞれを連結する管路として前処理原水６、加圧原水管路７、精製水管路８、濃縮水管路９がある。更に、該前処理部として活性炭濾過器あるいは活性炭繊維フィルターなどが設けられ残留塩素を除去するシステムが構築されている。
【０００５】
しかし、該活性炭濾過器あるいは活性炭繊維フィルターで処理させた原水は残留塩素が取り除かれ、逆に生菌増殖に好適な環境となってしまう。この前処理された原水は前処理原水管路６を通じて加圧部２に送られる。加圧部２は高圧ポンプなどで構成され、原水を加圧（約０．５〜２．０ＭＰａ）して原水加圧管路７を通じて膜分離部３に供給される。膜分離部３は逆浸透膜モジュール、圧力調整弁等で構成され、逆浸透膜を介して精製水と濃縮水に分離される。精製水は逆浸透膜の２次側（斜線部）を通過し精製水管路８を経てユースポイントに送液される。
【０００６】
この場合、ユースポイントで瞬間的に多量の精製水を使用する場合は、図３に示すように精製水貯留槽５を有している場合もある。前述のとおり、逆浸透膜１次側まで脱塩素水で供給されるため、ほとんどの場合、生菌増殖が認められる。逆浸透膜において原水中の生菌は排除され、逆浸透膜２次側には生菌が存在しないはずであるが、膜リークあるいは膜１次側と２次側を水密に維持しているＯリングなどの損傷によっても膜２次側は汚染される。また、初期状態においての膜モジュールのハンドリング、突発的工事などによる逆汚染の懸念もある。膜２次側から精製水管路８の領域については前処理水と同様に脱塩素水であり、生菌増殖に好適な環境であることに変わりなく汚染の心配もあるものである。
【０００７】
また、医療分野で使用される逆浸透膜モジュール式の精製水製造装置は、半導体業界などの工業用途と異なり、１日の治療が終われば装置は長時間停機しているのが一般的である。さらに、病院では緊急透析のために集中治療室に単身用逆浸透膜式精製水製造装置を長期間保管されている場合があるなど該装置の清浄度を維持することは難しい。また、透析治療は病院でのみ行われるのではなく、透析患者の家庭で行われる所謂、在宅透析を考慮しなければならない。この場合にも単身用逆浸透膜式の精製水製造装置が個人用透析装置とセットで使用されるが、在宅透析においては病院での装置使用の時間および使用頻度は比べものにならないくらい少なく、清浄度維持はますます困難な状況にある。
【０００８】
一方、透析治療技術法の発展に伴い、一層高いレベルの清浄度を透析液に要求されるようになった。すなわち、従来の透析療法が取り除いていた尿毒素成分よりさらに分子量の大きい成分が見出され、よりサイズの大きい物質を血液中から除去する必要が生じ、例えばＨＰＭ（ハイパフォーマンスメンブレン）という透析膜の孔径（ポアサイズ）の大きなダイアライザーが使用され始めた。
【０００９】
しかし、このことは従来は透析膜で阻止されていた透析液中の不純物が血液側に混入する危険性が高くなることを意味する。さらにはオンラインＨＤＦという、血液中の血漿成分を積極的に取り出し、それとほぼ当量の補液を血液に還流させる際に、透析液をクリーンに浄化することにより、患者の傍らで補液を製造する療法も普及し始めている。
【００１０】
そのため透析液が従来以上に高清浄度であることが要求されるが、透析液中の細菌のみならず、細菌の一種であるグラム陰性菌から派生するエンドトキシンも問題となってきた。エンドトキシンは、症状的にはパイロジェンとよばれる発熱を引き起こす毒素成分の総称である。グラム陰性菌自体は特別危険な細菌でなくとも、それが代謝あるいは死滅した際に、細胞壁から剥離して生成されるエンドトキシン、非常に取扱の難しい物質である。多量のエンドトキシンが体内に混入した場合には、患者に血圧低下や発熱をもたらし、さらに重篤な場合は患者の生命を危険な状態に陥れるものである。さらに、このエンドトキシンが細かく分裂した破片（フラグメント）による慢性的な障害が指摘されている。また、透析液のエンドトキシンの９割以上が逆浸透膜式モジュールによる精製水に由来するとの報告もある（例えば、第４３回透析医学会雑誌「Ｐ−３６０」）。
【００１１】
また、この逆浸透膜式モジュールの精製水中に棲息する細菌は、エンドトキシンを発生するグラム陰性かん菌が多い（例えば、「膜処理技術大系下巻」（フジ・テクノシステム））のである。
【００１２】
従来から逆浸透装置の薬液による殺菌消毒には、例えば、ホルマリンが使われていたが、処置後の薬剤洗い流しが困難（薬液残留）であること、さらに地球環境の問題から使用できなくなってきた。ホルマリン以外では過酸化水素および過酢酸などの酸素系薬剤、あるいは塩素系薬剤が間歇的に用いられている。
【００１３】
しかしながら、酸素系薬剤では、逆浸透膜内部の原水濃縮側に重金属（特に鉄分）が存在すると、それが触媒として作用し薬剤による膜の酸化劣化が急激に進行するため、事前にクエン酸などの酸洗浄を実施して重金属を取り除かなければならないなど操作が煩雑であり、処置時間が長くなるなどの問題がある。同様に塩素系薬剤も高濃度の場合は塩素による膜劣化は避けられない。また、逆浸透膜の構造が複雑なことから、薬剤では拡散・浸透しない箇所があるために、十分な殺菌効果が得られない場合が多い。
【００１４】
上記薬剤の他に殺菌消毒に熱水を使用するものがある。
【００１５】
例えば、特開平８−２５２６００号公報や特開平１１−３３３２６６号公報があるが、前者は熱水温度８０℃以上、後者は熱水温度９０℃以上の加熱条件が必要であり、逆浸透膜の耐熱性とは別に装置内配管の材質、熱水を排水する建家排水配管の耐熱性に注意しなければならない。
【００１６】
また、耐熱性の高い部材を使用しようとすれば一般的にコストアップにつながり、熱水温度が高くなると配管接合部の膨張と収縮の繰り返しにより緩みが生じ、水漏れなどの事故を誘発しかねない。
【００１７】
このような事情から、在宅透析における逆浸透膜式精製水製造装置も考慮して、経済的で、安全で安定的な殺菌消毒方法を実現することが求められている。
【００１８】
【発明が解決しようとする課題】
本発明は、従来装置の上記問題点を改善し、精製水清浄度を維持するための殺菌消毒機能を具備した逆浸透膜モジュール式の精製水製造装置を提供することを目的とする。更には、従来装置以上に操作性、経済性および安全性に優れた逆浸透膜モジュール式の精製水製造装置を提供することを目的とする。
【００１９】
【課題を解決するための手段】
かかる目的を達成する本発明の逆浸透膜モジュール式による精製水製造方法は、原水中の残留塩素を除去する前処理部で処理された前処理原水を逆浸透膜モジュールに圧送し、該前処理原水を逆浸透膜によって精製水と濃縮水に分離する精製水の製造方法において、６０℃以上７５℃未満の高温水を作成する加熱装置を設けて、該加熱装置により作成された前記高温水を前記膜分離モジュール部に供給し、さらに該膜分離モジュール部の精製水管路と濃縮水管路のそれぞれに前記加熱装置と連通する分岐管路を設け、膜分離モジュール部に供給した前記高温水を該分岐管路を介して前記加熱制御装置に回収／循環せしめて逆浸透膜モジュールを高温水消毒するように構成したことを特徴とする逆浸透膜モジュール式の精製水製造方法である。
【００２０】
また、本発明の逆浸透膜モジュール式の精製水製造装置は、以下の構成からなるものである。
【００２１】
すなわち、原水中の残留塩素を除去する前処理部と該前処理部で処理された前処理原水を圧送する加圧部と、該前処理原水を逆浸透膜によって精製水と濃縮水に分離する膜分離部を有する逆浸透膜モジュール式の精製水製造装置において、６０℃以上７５℃未満の高温水を作成する加熱装置を設け、さらに、前記前処理部と前記加圧部を連結する前処理原水配管上に前記加熱装置を連結させる高温水供給分岐管路を設け、さらに前記膜分離部の精製水管と濃縮水管上に前記加熱装置と連通する分岐管路を設け、膜分離部に供給した前記高温水を前記加熱装置に回収／循環せしめて逆浸透膜モジュールを高温水消毒するように構成したことを特徴とする逆浸透膜モジュール式の精製水製造装置である。
【００２２】
かかる本発明の逆浸透膜モジュール式の精製水製造装置において、好ましくは、膜分離部で分離された精製水を貯留する精製水貯留タンクを設け、さらにその精製貯留タンクに加熱制御機能を設けて加熱装置としたことを特徴とする逆浸透膜モジュール式の精製水製造装置である。
【００２３】
また、更にかかる本発明の逆浸透膜モジュール式の精製水製造装置において、好ましくは、逆浸透膜モジュール式の精製水製造装置による精製水が透析装置に供給されるように構成されてなるものである。
【００２４】
また、本発明は、上述した逆浸透膜モジュール式の精製水製造装置により精製された水を利用するように構成されてなる人工透析装置を提供するものである。
【００２５】
【発明の実施の形態】
以下、更に詳しく本発明を説明をする。
【００２６】
まず、本発明者らは、逆浸透膜式精製水製造装置および精製水送液配管など逆浸透膜モジュールで膜分離された精製水中に棲息する生菌の種類に着眼した。
【００２７】
その結果、逆浸透膜を透過した精製水中には生菌の栄養源になる有機物はほとんど存在せず、棲息できる生菌はシュードモナスなどのグラム陰性菌と呼ばれる、所謂、貧栄養菌に限られていることから、殺菌消毒の対象を貧栄養菌に絞り込み高温水に対する耐性を確認した。
【００２８】
表１は、透析用逆浸透膜式精製水製造装置の精製水をサンプルとして採取し、それを５０℃、６０℃、７０℃の各温度に加熱し、さらに加熱時間をそれぞれの加熱温度において１０分、３０分、６０分と変えて加熱処理を行ったものである。
【００２９】
【表１】

【００３０】
また、生菌は熱処理で完全に死滅していなければ、時間経過とともに再度増殖してくる可能性があることから、生菌測定は加熱処理直後と１日経過から１ヶ月経過後まで漸次測定フォローを実施して確実な殺菌効果が得られているかを検証したものである。生菌測定は３５℃−４８時間の寒天培地法により測定したものであり、測定結果から次の（１）、（２）の知見を得たのである。
（１）５０℃の加熱処理では処理直後で処理前の生菌数（ブランク数）より明らかに低下しているが完全死滅には至っていない。このため、１日経過以降では加熱時間に関わらず測定不能なまでに多数の生菌が増殖している。
（２）６０℃以上の加熱処理では１０分以上の加熱時間において、直後の殺菌状態（生菌数０ＣＦＵ／ｍｌ）が１ヶ月維持されており、生菌を死滅させることができたことを示している。すなわち、シュードモナスを殺菌対象とした場合、６０℃、１０分以上の高温水で十分殺菌効果があることが認められたのである。
【００３１】
本発明者らはかかる知見に基づき本発明に到達したものであり、更に具体的に、本発明の逆浸透膜モジュール式の精製水の製造方法と製造装置について説明をする。
【００３２】
本発明の逆浸透膜モジュール式の精製水の製造方法と製造装置は、図２に示したように加熱部４を設けてなるものである。
【００３３】
該加熱部４は、６０℃以上７５℃未満の温度の高温水を作成するものであり、加熱の方式は、電熱式ヒータによる加熱等の他に蒸気による熱交換方式でも良い。
【００３４】
加熱部４で加熱された高温水は前処理原水管路６と加熱部４を連結させる分岐管路１０を通り前処理原水管路６に送られる。加熱部４に高温水送液用ポンプがない場合は、加圧部２の高圧ポンプを使用することができる。この場合、通常の造水運転圧力とは異なり、膜にダメージを与えないように０．２ＭＰａ以下の低圧運転で行われる。加熱部４に高温水送液ポンプと高温水貯留タンクを設けて自己送液能力がある場合は、高温水分岐管路１０は加圧原水管路７に連結してもよい。
【００３５】
加熱高温水は膜分離部３に供給され、精製水管路８と濃縮水管路９とに分離されて出てくる。高温水消毒時はユースポイントに送液される精製水管路８、装置外に排出される濃縮水管路９を加熱部４とを連結させる分岐配管１１、１２にそれぞれ切り替えて加熱部４に回収／循環され、高温水循環経路内を一定温度に保つように制御される。
【００３６】
図３に示した本発明装置の態様例では、膜分離部３から得られた精製水は精製水貯留部５に貯留され、そこからポンプなどによりユースポイントに送られる。
【００３７】
この場合、精製水貯留部５の貯留槽内部に加熱部４を内蔵させることにより貯留槽で精製水を加温することが可能になる。加熱により得られた高温水は、前処理水管路６に連結された分岐管路１０を経て加圧部２に供給される。加圧部２、膜分離部３を経て得られた加温水の一部は精製水管路８を経て、精製水貯留部５の貯留槽に回収されて再度加熱される。膜分離部３を経て濃縮水管路９を通る高温水は前処理原水管路６から分岐した分岐管１２に回路を切り替えて循環される。
【００３８】
透析のシステムにおいては、透析液を３６℃まで加温するために必ず透析監視装置へ供給される透析液は、あるレベルまで加温されることが一般的であるが、図３に示す通りその加温機能を精製水貯留槽に搭載してある場合は、通常は透析液温度をある所定温度に加温制御するための加温装置として利用し、逆浸透膜モジュールを高温水殺菌する際には、それよりも高温度に加熱して使用することができるなどシステム全体での特別なコストアップにはならないのである。
【００３９】
本発明の逆浸透膜モジュール式の精製水製造方法もしくは装置において、加熱制置により作成され、回収／循環せしめられて逆浸透膜モジュールを高温水消毒する高温水温度は、好ましくは６０℃以上７５℃以下、より好ましくは６０℃以上７０℃以下のものである。また、加熱時間は逆浸透膜モジュールの内部の隅々まで所定高温水で満たし、温度で安定してから３０分以上見込んでおくのが良い。
【００４０】
本発明による高温水消毒を自動化することにより、特別な耐熱部材を選ぶ必要がなく、比較的温度が低くて効果が得られることから安全で、消費電力の面から経済的な殺菌消毒法である。また、前述したグラム陰性菌は貧栄養菌であり、成長速度が遅いことが知られており、高温水消毒を１週間に１回あるいは３日に１回程度の操作頻度で行うことにより、仮に生菌がごく僅か棲息していたとしても、その増殖を押さえ逆浸透膜モジュールを清浄維持できるのである。
【００４１】
上述の本発明にかかる逆浸透膜モジュール式の精製水製造装置により精製された水は、人工透析装置に効果的に利用することができる。すなわち、本発明は、該精製水製造装置で精製された水を利用するように構成された人工透析装置を提供するものである。
【００４２】
本発明にかかる逆浸透膜モジュール式の精製水製造装置において、その消毒手法は消毒用薬剤の停滞などの危険性を考える必要が実際上なく、また操作が簡単であることから、隔日に実施される個人透析、あるいは日曜が休みになるセンター透析などには極めて有用な透析装置を構成できるものだからである。
【００４３】
【発明の効果】
本発明によれば、従来考えられていた逆浸透膜式の精製水製造装置、特に医療分野における該装置の精製水側殺菌消毒を比較的低い温度の高温水で行うものであり、操作が容易で、安全で、安定的に実施することが可能となる。
【００４４】
さらに、本発明にかかる逆浸透膜モジュール式の精製水製造装置は、エンドトキシンを産生するグラム陰性菌を殺菌対象とするものであり、エンドトキシン汚染のない良質な透析治療を可能にすることができる。
【００４５】
本発明は、停機時間の長いあるいは使用頻度の少ない医療用逆浸透膜モジュール式の精製水製造装置、特に在宅透析で使用される単身用逆浸透膜モジュール式精製水製造装置の清浄度維持に特に有効である。
【００４６】
また、本発明方法・装置によれば、消毒用薬剤の停滞などの危険性を考えることなく、操作が簡単であることから隔日に実施される個人透析、あるいは日曜が休みになるセンター透析に極めて有用な消毒手段を提供できたものである。
【図面の簡単な説明】
【図１】図１は、従来において通常の逆浸透膜式モジュール式精製水製造装置を示した概略フロー図である。
【図２】図２は、本発明の方法・装置の一実施態様例を示したものであり、図１の装置において特に加熱部を設け、熱水循環による消毒システムを示したフロー図である。
【図３】図３は、本発明の方法・装置の一実施態様例を示したものであり、図１の装置に精製水貯留部および貯槽内加熱部を設け熱水循環による消毒システムを示したフロー図である。
【符号の説明】
１：前処理部
２：加圧部
３：膜分離部
４：加熱部
５：精製水貯留部
６：前処理原水管路
７：加圧原水管路
８：精製水管路
９：濃縮水管路
１０：分岐管路
１１：分岐管路
１２：分岐管路[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and apparatus for producing purified water using a reverse osmosis membrane module.
[0002]
More specifically, in the medical field, purified water or purified water close to pure water used for washing, blending, and dilution applications, particularly purified water supplied to a dialysis machine in a state substantially free of bacteria and endotoxin contamination. The present invention relates to a reverse osmosis membrane modular purified water production method and a production apparatus that can be produced.
[0003]
[Prior art]
At present, the reverse osmosis membrane used in the reverse osmosis membrane-type purified water production apparatus is often used in the medical field, in particular, in the medical field, a crosslinked polyamide composite membrane having a large amount of permeated water at low pressure operation and a high salt rejection rate due to its use environment. . However, the dense layer on the surface of the reverse osmosis membrane has a thickness of about 0.2 μm, and if residual chlorine is contained in the raw water, it causes deterioration with time of chlorine and leads to a decrease in performance such as a decrease in salt rejection.
[0004]
BACKGROUND ART Conventionally, a general reverse osmosis membrane module type purified water production apparatus includes a pretreatment section 1, a pressurization section 2, and a membrane separation section 3 as shown in FIG. There are treated raw water 6, pressurized raw water conduit 7, purified water conduit 8, and concentrated water conduit 9. Further, an activated carbon filter or an activated carbon fiber filter is provided as the pretreatment unit, and a system for removing residual chlorine has been constructed.
[0005]
However, the raw water treated with the activated carbon filter or the activated carbon fiber filter is free of residual chlorine, and on the contrary, becomes an environment suitable for the growth of live bacteria. The pretreated raw water is sent to the pressurizing unit 2 through the pretreated raw water pipe 6. The pressurizing section 2 is composed of a high-pressure pump or the like, and pressurizes raw water (about 0.5 to 2.0 MPa) and supplies the raw water to the membrane separation section 3 through a raw water pressurizing pipe 7. The membrane separation unit 3 includes a reverse osmosis membrane module, a pressure control valve, and the like, and is separated into purified water and concentrated water via the reverse osmosis membrane. The purified water passes through the secondary side (hatched portion) of the reverse osmosis membrane and is sent to the use point via the purified water pipe 8.
[0006]
In this case, when a large amount of purified water is used instantaneously at the point of use, a purified water storage tank 5 may be provided as shown in FIG. As described above, since the water is supplied to the primary side of the reverse osmosis membrane with dechlorinated water, viable cell growth is observed in most cases. Live bacteria in raw water are eliminated in the reverse osmosis membrane, and there should be no viable bacteria on the secondary side of the reverse osmosis membrane. However, membrane leakage or O which maintains the membrane primary and secondary sides watertight is not possible. The membrane secondary side is also contaminated by damage such as a ring. In addition, there is a concern about reverse contamination due to handling of the membrane module in an initial state, sudden construction, and the like. The area from the secondary side of the membrane to the purified water pipeline 8 is dechlorinated water as in the case of the pre-treated water, and there is no doubt that the environment is suitable for the growth of viable bacteria, and there is a concern about contamination.
[0007]
In addition, the reverse osmosis membrane module type purified water production device used in the medical field is different from industrial applications such as the semiconductor industry, and the device is generally stopped for a long time after one day of treatment. . Further, in hospitals, it is difficult to maintain the cleanliness of a single-use reverse osmosis membrane-type purified water producing apparatus in an intensive care unit for an emergency dialysis, for example, for a long period of time. In addition, dialysis treatment must be performed not only in a hospital but also in a so-called home dialysis performed in the home of a dialysis patient. In this case as well, a single-use reverse osmosis membrane-type purified water production system is used as a set with a personal dialysis system.However, in home dialysis, the time and frequency of use of the system in hospitals is so small that it cannot be compared. Degree maintenance is increasingly difficult.
[0008]
On the other hand, with the development of the dialysis treatment technique, a higher level of cleanliness has been required for the dialysate. That is, a component having a higher molecular weight than the uremic toxin component removed by the conventional dialysis therapy is found, and it is necessary to remove a larger substance from the blood. For example, the pore size of a dialysis membrane called HPM (high performance membrane) is required. Large (pore size) dialysers have begun to be used.
[0009]
However, this means that there is a high risk that impurities in the dialysate, which were conventionally blocked by the dialysis membrane, are mixed into the blood side. In addition, online HDF, a therapy that actively removes blood plasma components from blood and returns a nearly equivalent amount of replacement fluid to the blood, purifies the dialysate cleanly to produce a replacement fluid beside the patient. It is starting to spread.
[0010]
Therefore, the dialysate is required to have a higher degree of cleanliness than before. However, not only bacteria in the dialysate but also endotoxins derived from gram-negative bacteria, which is a kind of bacteria, have become a problem. Endotoxin is a general term for a toxin component that causes fever, which is symptomatically called pyrogen. Gram-negative bacteria are not particularly dangerous bacteria, but are endotoxins, which are exfoliated from cell walls when they are metabolized or killed, and are very difficult to handle. When a large amount of endotoxin is contaminated in the body, it causes a decrease in blood pressure and fever in the patient, and when serious, endangers the patient's life. In addition, chronic damage due to finely divided fragments of this endotoxin has been pointed out. In addition, there is a report that 90% or more of endotoxin in a dialysis solution is derived from purified water by a reverse osmosis membrane module (for example, the 43rd dialysis medical association magazine “P-360”).
[0011]
In addition, the bacteria that inhabit the purified water of the reverse osmosis membrane module are mostly gram-negative bacilli that generate endotoxin (for example, “Membrane Processing Technology System 2” (Fuji Techno System)).
[0012]
Conventionally, for example, formalin has been used for sterilization and disinfection using a chemical solution in a reverse osmosis device. However, it has become difficult to wash out the chemical after treatment (residual chemical solution), and it has become impossible to use it because of the problem of the global environment. Other than formalin, oxygen-based drugs such as hydrogen peroxide and peracetic acid, or chlorine-based drugs are used intermittently.
[0013]
However, in the case of oxygen-based chemicals, if heavy metals (especially iron) are present on the concentrated side of raw water inside the reverse osmosis membrane, they act as a catalyst and the oxidative degradation of the membrane by the chemicals proceeds rapidly. The operation is complicated, for example, heavy metals must be removed by carrying out acid cleaning, and there is a problem that the treatment time is long. Similarly, when the concentration of chlorine-based chemicals is high, film deterioration due to chlorine cannot be avoided. In addition, since the structure of the reverse osmosis membrane is complex, there are many places where the medicine does not diffuse or permeate, so that a sufficient sterilizing effect cannot be obtained in many cases.
[0014]
In addition to the above-mentioned chemicals, there are some which use hot water for sterilization.
[0015]
For example, JP-A-8-252600 and JP-A-11-333266 are known. The former requires heating conditions of a hot water temperature of 80 ° C. or higher, and the latter requires a heating condition of a hot water temperature of 90 ° C. or higher. In addition to heat resistance, attention must be paid to the material of the piping inside the equipment and the heat resistance of the building drainage pipe that drains hot water.
[0016]
In addition, the use of a member with high heat resistance generally leads to an increase in cost, and if the temperature of hot water increases, loosening occurs due to repeated expansion and contraction of the pipe joint, which may lead to accidents such as water leakage. Absent.
[0017]
Under such circumstances, it is required to realize an economical, safe and stable sterilization and disinfection method in consideration of a reverse osmosis membrane type purified water production apparatus in home dialysis.
[0018]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a reverse osmosis membrane module type purified water production apparatus having a sterilization function for improving the purity of purified water while improving the above problems of the conventional apparatus. It is a further object of the present invention to provide a reverse osmosis membrane module type purified water producing apparatus which is more operable, economical and safe than conventional apparatuses.
[0019]
[Means for Solving the Problems]
In order to achieve the above object, a method for producing purified water by a reverse osmosis membrane module of the present invention comprises feeding a pretreated raw water treated in a pretreatment section for removing residual chlorine in the raw water to a reverse osmosis membrane module under pressure. In a method for producing purified water in which raw water is separated into purified water and concentrated water by a reverse osmosis membrane, a heating device for producing high-temperature water of 60 ° C or more and less than 75 ° C is provided, and the high-temperature water produced by the heating device is provided. The high-temperature water supplied to the membrane separation module is provided to each of the purified water pipeline and the concentrated water pipeline of the membrane separation module. A reverse osmosis membrane module-type purified water production method, characterized in that the reverse osmosis membrane module is collected / circulated to the heating control device via a branch pipe to disinfect the reverse osmosis membrane module with high-temperature water.
[0020]
Further, a reverse osmosis membrane module type purified water production apparatus of the present invention has the following configuration.
[0021]
That is, a pretreatment section for removing residual chlorine in the raw water, a pressurizing section for pumping the pretreatment raw water treated in the pretreatment section, and separating the pretreatment raw water into purified water and concentrated water by a reverse osmosis membrane. In a reverse osmosis membrane module type purified water production device having a membrane separation unit, a heating device for producing high-temperature water of 60 ° C. or more and less than 75 ° C. is provided, and further, a pre-treatment for connecting the pre-treatment unit and the pressurizing unit A high-temperature water supply branch line connecting the heating device is provided on the raw water pipe, and a branch line communicating with the heating device is further provided on the purified water pipe and the concentrated water pipe of the membrane separation unit, and the supply is performed to the membrane separation unit. A reverse osmosis membrane module type purified water production apparatus, wherein the high temperature water is recovered / circulated to the heating device to disinfect the reverse osmosis membrane module with high temperature water.
[0022]
In the reverse osmosis membrane module-type purified water production apparatus of the present invention, preferably, a purified water storage tank for storing purified water separated by the membrane separation unit is provided, and the purification storage tank is further provided with a heating control function. It is a reverse osmosis membrane module type purified water production apparatus, which is a heating apparatus.
[0023]
Further, in the reverse osmosis membrane module-type purified water production apparatus of the present invention, preferably, the purified water produced by the reverse osmosis membrane module-type purified water production apparatus is configured to be supplied to a dialysis apparatus. is there.
[0024]
The present invention also provides an artificial dialysis device configured to use water purified by the above-described reverse osmosis membrane module-type purified water production device.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail.
[0026]
First, the present inventors have focused on the types of living bacteria that live in purified water that has been subjected to membrane separation by a reverse osmosis membrane module such as a reverse osmosis membrane type purified water production device and a purified water supply pipe.
[0027]
As a result, there is almost no organic matter serving as a nutrient source for live bacteria in purified water that has passed through the reverse osmosis membrane, and live bacteria that can live are limited to so-called oligotrophic bacteria called gram-negative bacteria such as Pseudomonas. Therefore, the target of sterilization was narrowed down to oligotrophic bacteria and its resistance to high-temperature water was confirmed.
[0028]
Table 1 shows that the purified water from the reverse osmosis membrane type purified water production apparatus for dialysis was sampled, heated to 50 ° C., 60 ° C., and 70 ° C., and further heated for 10 minutes at each heating temperature. Minutes, 30 minutes, and 60 minutes.
[0029]
[Table 1]

[0030]
In addition, if live bacteria are not completely killed by heat treatment, they may grow again over time. Therefore, live bacteria measurement should be performed immediately after heat treatment and gradually from 1 day to 1 month. And verified whether a certain sterilization effect was obtained. The viable bacteria were measured by the agar medium method at 35 ° C. for 48 hours, and the following findings (1) and (2) were obtained from the measurement results.
(1) In the heat treatment at 50 ° C., the viable cell count (blank count) immediately after the treatment is clearly lower than that before the treatment, but is not completely killed. Therefore, after one day, a large number of viable bacteria have proliferated until measurement becomes impossible regardless of the heating time.
(2) In the heat treatment at 60 ° C. or more, the sterilization state immediately after the heating time was 10 minutes or more (the number of viable bacteria 0 CFU / ml) was maintained for one month, indicating that the viable bacteria could be killed. ing. That is, when Pseudomonas was to be sterilized, it was confirmed that high-temperature water at 60 ° C. for 10 minutes or more had a sufficient sterilizing effect.
[0031]
The present inventors have reached the present invention based on such findings, and more specifically, a method and an apparatus for producing purified water of the reverse osmosis membrane module type of the present invention will be described.
[0032]
The method and apparatus for producing purified water of the reverse osmosis membrane module type of the present invention are provided with a heating unit 4 as shown in FIG.
[0033]
The heating unit 4 is for producing high-temperature water having a temperature of 60 ° C. or more and less than 75 ° C. The heating method may be a heat exchange method using steam in addition to heating using an electric heater.
[0034]
The high-temperature water heated by the heating unit 4 is sent to the pretreatment raw water pipeline 6 through a branch pipeline 10 connecting the pretreatment raw water pipeline 6 and the heating unit 4. If the heating unit 4 does not have a high-temperature water pump, the high-pressure pump of the pressurizing unit 2 can be used. In this case, unlike the normal fresh water operating pressure, the operation is performed at a low pressure of 0.2 MPa or less so as not to damage the membrane. If the heating section 4 is provided with a high-temperature water liquid supply pump and a high-temperature water storage tank and has a self-liquid supply capability, the high-temperature water branch pipe 10 may be connected to the pressurized raw water pipe 7.
[0035]
The heated high-temperature water is supplied to the membrane separation unit 3 and is separated into a purified water pipe 8 and a concentrated water pipe 9 and comes out. At the time of high-temperature water disinfection, the purified water pipe 8 sent to the point of use and the concentrated water pipe 9 discharged outside the apparatus are switched to branch

pipes

11 and 12 connecting the heating section 4 and collected / recovered by the heating section 4. It is circulated and controlled to maintain a constant temperature in the high-temperature water circulation path.
[0036]
In the embodiment of the apparatus of the present invention shown in FIG. 3, purified water obtained from the membrane separation unit 3 is stored in a purified water storage unit 5 and sent to a use point by a pump or the like from there.
[0037]
In this case, by providing the heating unit 4 inside the storage tank of the purified water storage unit 5, it becomes possible to heat the purified water in the storage tank. The high-temperature water obtained by the heating is supplied to the pressurizing unit 2 via the branch pipe 10 connected to the pretreatment water pipe 6. A portion of the heated water obtained through the pressurizing section 2 and the membrane separation section 3 is collected in the storage tank of the purified water storage section 5 through the purified water pipe 8 and is heated again. The high-temperature water passing through the concentrated water pipe 9 via the membrane separation unit 3 is circulated by switching the circuit to a branch pipe 12 branched from the pretreatment raw water pipe 6.
[0038]
In a dialysis system, the dialysis solution always supplied to the dialysis monitoring device in order to heat the dialysis solution to 36 ° C. is generally heated to a certain level, but as shown in FIG. When the heating function is installed in the purified water storage tank, it is usually used as a heating device to control the temperature of the dialysate to a certain predetermined temperature, and when the reverse osmosis membrane module is sterilized with high temperature water. Does not increase the overall cost of the system as a whole, because it can be used after being heated to a higher temperature.
[0039]
In the method or apparatus for producing purified water of the reverse osmosis membrane module type of the present invention, the high-temperature water temperature which is prepared by heating, recovered / circulated, and disinfects the reverse osmosis membrane module with high-temperature water is preferably 60 ° C. or more and 75 ° C. ° C or lower, more preferably 60 ° C or higher and 70 ° C or lower. Further, it is preferable that the heating time is filled with a predetermined high-temperature water to every corner inside the reverse osmosis membrane module and 30 minutes or more after the temperature is stabilized.
[0040]
By automating the high-temperature water disinfection according to the present invention, there is no need to select a special heat-resistant member, and since the effect is obtained at a relatively low temperature, the method is safe and economical in terms of power consumption. . In addition, the gram-negative bacteria described above are oligotrophic bacteria, and are known to have a low growth rate. Therefore, by performing high-temperature water disinfection once a week or about once every three days, it is assumed that Even if there are very few live bacteria, they can suppress the growth and keep the reverse osmosis membrane module clean.
[0041]
The water purified by the above-described reverse osmosis membrane module type purified water production apparatus according to the present invention can be effectively used for an artificial dialysis apparatus. That is, the present invention provides an artificial dialysis device configured to use water purified by the purified water production device.
[0042]
In the purified water production apparatus of the reverse osmosis membrane module type according to the present invention, the disinfection method is practiced every other day because there is practically no need to consider the danger such as stagnation of the disinfectant and the operation is simple. This is because a very useful dialysis device can be constructed for personal dialysis or center dialysis where Sundays are closed.
[0043]
【The invention's effect】
According to the present invention, a reverse osmosis membrane-type purified water production apparatus which has been conventionally considered, particularly, in which the purified water side sterilization and disinfection of the apparatus in the medical field is performed with high-temperature water having a relatively low temperature, and the operation is easy. Thus, it is possible to perform the operation safely and stably.
[0044]
Further, the reverse osmosis membrane module-type purified water production apparatus according to the present invention targets gram-negative bacteria that produce endotoxin, thereby enabling high-quality dialysis treatment without endotoxin contamination.
[0045]
The present invention is particularly useful for maintaining the cleanliness of a medical reverse osmosis membrane module-type purified water production apparatus having a long stoppage time or less frequently used, particularly a single-use reverse osmosis membrane module-type purified water production apparatus used in home dialysis. It is valid.
[0046]
Further, according to the method / apparatus of the present invention, the operation is simple and the personal dialysis performed every other day or the center dialysis where Sunday is closed without considering the danger such as stagnation of the disinfecting agent. It has provided useful disinfection means.
[Brief description of the drawings]
FIG. 1 is a schematic flow chart showing a conventional reverse osmosis membrane type modular purified water production apparatus in the related art.
FIG. 2 shows an example of an embodiment of the method / apparatus of the present invention, and is a flow diagram showing a disinfection system provided with a heating unit in the apparatus of FIG. 1 and circulating hot water. .
FIG. 3 shows an embodiment of the method / apparatus of the present invention, and shows a disinfection system using hot water circulation by providing a purified water storage section and a heating section in a storage tank in the apparatus shown in FIG. FIG.
[Explanation of symbols]
1: Pretreatment unit 2: Pressurization unit 3: Membrane separation unit 4: Heating unit 5: Purified water storage unit 6: Pretreatment raw water pipeline 7: Pressurized raw water pipeline 8: Purified water pipeline 9: Concentrated water pipeline 10 : Branch line 11: Branch line 12: Branch line

Claims

A method for producing purified water in which pretreated raw water treated in a pretreatment section for removing residual chlorine in raw water is pumped to a reverse osmosis membrane module, and the pretreated raw water is separated into purified water and concentrated water by a reverse osmosis membrane. Providing a heating device for producing high-temperature water of 60 ° C. or more and less than 75 ° C., supplying the high-temperature water produced by the heating device to the membrane separation module section, and further comprising a purified water pipe of the membrane separation module section. A branch line communicating with the heating device is provided in each of the concentrated water lines, and the high-temperature water supplied to the membrane separation module section is collected / circulated to the heating device through the branch line to form a reverse osmosis membrane module. A method for producing purified water using a reverse osmosis membrane module, which is configured to disinfect high-temperature water.

A pretreatment section for removing residual chlorine in the raw water, a pressurizing section for pumping the pretreatment raw water treated in the pretreatment section, and a membrane separation for separating the pretreatment raw water into purified water and concentrated water by a reverse osmosis membrane In a reverse osmosis membrane module type purified water production apparatus having a section, a heating control apparatus for producing high-temperature water of 60 ° C. or more and less than 75 ° C. is provided, and further, pre-treated raw water for connecting the pre-treatment section and the pressurizing section. A high-temperature water supply branch pipe connecting the heating device is provided on the pipe, and a branch pipe communicating with the heating device is further provided on the purified water pipe and the concentrated water pipe of the membrane separation unit, and the supply to the membrane separation unit is performed. A reverse osmosis membrane module type purified water production apparatus, wherein high temperature water is collected / circulated to the heating device to disinfect the reverse osmosis membrane module with high temperature water.

In the reverse osmosis membrane type purified water production apparatus according to claim 2, a purified water storage tank for storing purified water separated by the membrane separation unit is provided, and the heating device is further provided with a heating function in the purified storage tank. A reverse osmosis membrane module type purified water production apparatus, characterized in that:

4. A reverse osmosis membrane module-type purified water production apparatus characterized in that purified water produced by the reverse osmosis membrane module-type purified water production apparatus according to claim 2 or 3 is supplied to a dialysis apparatus. .

A dialysis apparatus characterized by using water purified by the reverse osmosis membrane module type purified water production apparatus according to claim 2 or 3.