JP2000189993A - Activated sludge treatment by membrane separation - Google Patents

Activated sludge treatment by membrane separation

Info

Publication number
JP2000189993A
JP2000189993A JP36823498A JP36823498A JP2000189993A JP 2000189993 A JP2000189993 A JP 2000189993A JP 36823498 A JP36823498 A JP 36823498A JP 36823498 A JP36823498 A JP 36823498A JP 2000189993 A JP2000189993 A JP 2000189993A
Authority
JP
Japan
Prior art keywords
separation
activated sludge
membrane
water
separation membrane
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.)
Withdrawn
Application number
JP36823498A
Other languages
Japanese (ja)
Inventor
Masumi Kobayashi
真澄 小林
Manabu Yanou
学 矢能
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.)
Mitsubishi Rayon Co Ltd
Original Assignee
Mitsubishi Rayon Co 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 Mitsubishi Rayon Co Ltd filed Critical Mitsubishi Rayon Co Ltd
Priority to JP36823498A priority Critical patent/JP2000189993A/en
Publication of JP2000189993A publication Critical patent/JP2000189993A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00Technologies for wastewater treatment
    • Y02W10/10Biological treatment of water, waste water, or sewage

Landscapes

  • Separation Using Semi-Permeable Membranes (AREA)
  • Activated Sludge Processes (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a activated sludge treating method by membrane separation capable of performing a stable solid-liquid separation while preventing the excess adsorption of organic materials on the membrane surface of a separation membrane module in an initial operation stage of a waste water treating system. SOLUTION: In the activated sludge treating method by membrane separation capable of performing a biological treatment for degrading organic materials in water to be treated by microorganisms in the activated sludge and a solid- liquid separation treatment by the separation membrane module 3 in the same aerobic tank 6, a method that the activated sludge is previously added into the aerobic tank 6 so that the MLSS concentration of the water to be treated in the aerobic tank 6 is >=2000 mg/l is used.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、活性汚泥中の微生
物によって被処理水中の有機物を分解する生物処理と、
分離膜モジュールによる固液分離処理とを同一の槽内で
行う膜分離活性汚泥処理方法に関し、詳しくは、排水処
理システムの運転初期段階での分離膜モジュールの膜面
への有機物の付着を防ぎ、安定して固液分離処理を行う
ことができる膜分離活性汚泥処理方法に関する。
TECHNICAL FIELD The present invention relates to a biological treatment for decomposing organic substances in water to be treated by microorganisms in activated sludge,
Regarding the membrane separation activated sludge treatment method in which the solid-liquid separation treatment by the separation membrane module and the solid-liquid separation treatment in the same tank, specifically, to prevent organic substances from adhering to the membrane surface of the separation membrane module in the initial stage of operation of the wastewater treatment system, The present invention relates to a membrane separation activated sludge treatment method capable of performing a solid-liquid separation treatment stably.

【0002】[0002]

【従来の技術】下水やし尿などの生活排水、工場等から
の有機性産業排水などの汚濁性の高い排水(以下、被処
理水と記す)は、その中に含まれる種々の懸濁物質(S
S)、有機物等を取り除く処理が施されてから、河川な
どに放流されている。そのような排水処理システムにお
いては、例えば、図3に示すように、まず、調整槽31
に貯留された被処理水を、圧空ポンプ32とこれに接続
した散気装置33とが設けられた曝気槽34に、移送ポ
ンプ35を用いて移す。この曝気槽34中では、活性汚
泥中の好気性微生物に酸素を与えて被処理水中の有機物
(BOD成分)を分解する生物処理が行われる。その
後、沈殿槽36にて、重力沈降により固液分離を行い、
分離された処理水は河川などに放流され、一方、分離さ
れた汚泥の一部は返送汚泥として曝気槽34に戻され、
残りの汚泥は余剰汚泥として最終的に処分される。
BACKGROUND ART Highly polluting wastewater (hereinafter referred to as treated water) such as domestic wastewater such as sewage and human waste, and organic industrial wastewater from factories and the like are treated with various suspended substances contained therein. S
S), after being subjected to a process of removing organic substances and the like, is discharged to rivers and the like. In such a wastewater treatment system, for example, as shown in FIG.
Is transferred to an aeration tank 34 provided with a compressed air pump 32 and an air diffuser 33 connected thereto using a transfer pump 35. In the aeration tank 34, biological treatment is performed in which oxygen is supplied to the aerobic microorganisms in the activated sludge to decompose organic substances (BOD components) in the water to be treated. Thereafter, in the sedimentation tank 36, solid-liquid separation is performed by gravity sedimentation,
The separated treated water is discharged into a river or the like, while a part of the separated sludge is returned to the aeration tank 34 as returned sludge,
The remaining sludge is finally disposed of as excess sludge.

【0003】しかしながら、この活性汚泥による処理方
法では、糸状菌によるバルキングが発生した場合、バル
キング状態の汚泥が被処理水の水面に浮いてしまうため
に、沈殿槽36での重力沈降による固液分離ができなく
なり、河川等に放流される処理水中に汚泥が混入し、水
質を悪化させてしまうという問題があった。また、曝気
槽34において混合液浮遊物質(以下、MLSSと記
す)、すなわち活性汚泥を高濃度に維持することが困難
となり、生物処理の効率も悪くなるという問題があっ
た。
However, according to this activated sludge treatment method, if bulking due to filamentous fungi occurs, the sludge in the bulking state floats on the surface of the water to be treated, so that solid-liquid separation by gravity sedimentation in the sedimentation tank 36 is performed. There is a problem that sludge is mixed in the treated water discharged into a river or the like, and deteriorates the water quality. Further, there is a problem that it is difficult to maintain a high concentration of the mixed liquid suspended solid (hereinafter, referred to as MLSS), that is, activated sludge, in the aeration tank 34, and the efficiency of biological treatment is reduced.

【0004】このような問題を解決する方法として、近
年、吸引ポンプに接続された分離膜モジュールや、この
分離膜モジュールが複数配設された分離膜モジュールユ
ニットを用いた膜分離活性汚泥処理方法が利用されてき
ている。この膜分離活性汚泥処理方法としては、例え
ば、図1に示すようなシステムを用いた方法が挙げられ
る。まず、調整槽1に貯留された被処理水を、吸引ポン
プ2に接続した分離膜モジュール3と、圧空ポンプ4に
接続した散気装置5とが設けられた曝気槽6に、移送ポ
ンプ7を用いて移す。この曝気槽6中では、分離膜モジ
ュール3による固液分離処理と、活性汚泥中の好気性微
生物に酸素を与えて被処理水中の有機物(BOD成分)
を分解する生物処理とが行われる。被処理水は分離膜モ
ジュール3の濾液側を吸引することによって濾過され、
濾過された処理水(濾液)は河川等に放流される。この
ような膜分離活性汚泥処理方法を用いることによって、
沈殿槽が不要となるので、処理水の水質を良好に保つこ
とができ、また、曝気槽6のMLSS濃度を高く維持で
きるようになる。
As a method for solving such a problem, a separation membrane module connected to a suction pump or a membrane separation activated sludge treatment method using a separation membrane module unit provided with a plurality of the separation membrane modules has recently been proposed. Has been used. As this membrane separation activated sludge treatment method, for example, a method using a system as shown in FIG. 1 can be mentioned. First, the water to be treated stored in the adjustment tank 1 is transferred to an aeration tank 6 provided with a separation membrane module 3 connected to a suction pump 2 and an air diffuser 5 connected to a compressed air pump 4 by a transfer pump 7. Transfer using. In the aeration tank 6, the solid-liquid separation treatment by the separation membrane module 3 and the oxygenation of the aerobic microorganisms in the activated sludge to give organic substances (BOD components) in the water to be treated.
And a biological treatment for decomposing. The water to be treated is filtered by sucking the filtrate side of the separation membrane module 3,
The filtered treated water (filtrate) is discharged to a river or the like. By using such a membrane separation activated sludge treatment method,
Since a sedimentation tank is not required, the quality of the treated water can be kept good, and the MLSS concentration in the aeration tank 6 can be maintained high.

【0005】[0005]

【発明が解決しようとする課題】しかしながら、前記M
LSSは、従来の排水処理システムの最初の運転開始時
には曝気槽中にほとんど、またはまったく存在せず、運
転を長時間続けることによって徐々に十分な濃度、例え
ば3000〜5000mg/lまで増えるものであった
ため、排水処理システムの運転初期段階においてはML
SS濃度は低く、曝気槽でのBOD成分の分解能力は不
十分であった。そのため、図1に示すような膜分離活性
汚泥処理方法を用いた排水処理システムでは、運転初期
段階において、分解されないBOD成分の有機物が分離
膜モジュール3の膜面に多量に吸着して目詰まりを起こ
し、分離膜モジュール3の内外の差圧が上昇し、安定し
た固液分離処理ができなくなるという問題があった。
However, the above M
LSS is little or no present in the aeration tank at the first start of operation of the conventional wastewater treatment system, and gradually increases to a sufficient concentration, for example, 3000 to 5000 mg / l by continuing operation for a long time. Therefore, in the early stage of operation of the wastewater treatment system, ML
The SS concentration was low, and the ability to decompose BOD components in the aeration tank was insufficient. For this reason, in the wastewater treatment system using the membrane separation activated sludge treatment method as shown in FIG. As a result, there is a problem that the pressure difference between the inside and outside of the separation membrane module 3 increases, so that stable solid-liquid separation processing cannot be performed.

【0006】よって、本発明における課題は、排水処理
システムの運転初期段階における分離膜モジュールの膜
面への有機物の過度な吸着を防ぎ、安定して固液分離処
理を行うことができる膜分離活性汚泥処理方法を提供す
ることにある。
Accordingly, an object of the present invention is to prevent excessive adsorption of organic substances to the membrane surface of a separation membrane module in an initial stage of operation of a wastewater treatment system, and to carry out a solid-liquid separation process stably. It is to provide a sludge treatment method.

【0007】[0007]

【課題を解決するための手段】すなわち、本発明の膜分
離活性汚泥処理方法は、活性汚泥中の微生物によって被
処理水の有機物を分解する生物処理と、分離膜モジュー
ルによる固液分離処理とを同一の槽内で行う膜分離活性
汚泥処理方法において、最初の運転開始までに、あらか
じめ前記槽内の被処理水のMLSS濃度が2000mg
/l以上となるように前記槽内に活性汚泥を加えておく
ことを特徴とする。
That is, the membrane separation activated sludge treatment method of the present invention comprises a biological treatment in which microorganisms in activated sludge decompose organic substances in water to be treated and a solid-liquid separation treatment by a separation membrane module. In the membrane separation activated sludge treatment method performed in the same tank, the MLSS concentration of the water to be treated in the tank is set to 2000 mg before the first operation.
Activated sludge is added to the tank so as to be at least / l.

【0008】[0008]

【発明の実施の形態】以下、図面を参照しながら本発明
を詳しく説明する。図1は、膜分離活性汚泥処理方法を
用いた排水処理システムの一例を示す概略図である。ま
ず、スクリーン(図示略)等で被処理水中の比較的大き
な懸濁物質を取り除いた後、調整槽1に貯留された被処
理水を、吸引ポンプ2に接続した分離膜モジュール3
と、圧空ポンプ4に接続した散気装置5とが設けられた
曝気槽6に、移送ポンプ7を用いて移す。この曝気槽6
中では、分離膜モジュール3による固液分離処理と、活
性汚泥中の好気性微生物に酸素を与えて被処理水中の有
機物(BOD成分)を分解する生物処理とが行われる。
被処理水は分離膜モジュール3の濾液側を吸引すること
によって濾過され、濾過された処理水(濾液)は、集水
配管8によって集水され、河川等に放流される。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a wastewater treatment system using a membrane separation activated sludge treatment method. First, after a relatively large suspended substance in the water to be treated is removed with a screen (not shown) or the like, the water to be treated stored in the adjustment tank 1 is separated from the separation membrane module 3 connected to the suction pump 2.
And an aeration tank 6 provided with an air diffuser 5 connected to the compressed air pump 4 using a transfer pump 7. This aeration tank 6
Among them, a solid-liquid separation treatment by the separation membrane module 3 and a biological treatment for decomposing organic substances (BOD components) in the water to be treated by supplying oxygen to the aerobic microorganisms in the activated sludge are performed.
The water to be treated is filtered by sucking the filtrate side of the separation membrane module 3, and the filtered treated water (filtrate) is collected by the water collection pipe 8 and discharged to a river or the like.

【0009】本発明においては、このような排水処理シ
ステムの最初の運転開始までに、あらかじめ前記曝気槽
6内の被処理水のMLSS濃度が2000mg/l以上
となるように曝気槽6内に活性汚泥を加えておくこと
(以下、シーディングと記す)に特徴がある。MLSS
濃度が2000mg/l未満では、BOD成分の分解能
力が不十分となり、BOD成分が分離膜モジュール3の
膜面に多量に吸着され、安定して濾過処理を行うことが
できなくなる。MLSS濃度は、好ましくは3000〜
8000mg/lの範囲である。
In the present invention, the active water in the aeration tank 6 is controlled so that the MLSS concentration of the water to be treated in the aeration tank 6 becomes 2000 mg / l or more before the first operation of the wastewater treatment system. The feature is that sludge is added (hereinafter referred to as seeding). MLSS
If the concentration is less than 2000 mg / l, the ability to decompose the BOD component will be insufficient, and a large amount of the BOD component will be adsorbed on the membrane surface of the separation membrane module 3, making it impossible to perform a stable filtration treatment. The MLSS concentration is preferably between 3000 and
It is in the range of 8000 mg / l.

【0010】曝気槽6にシーディングする活性汚泥とし
ては、特に限定はされないが、例えば、既設の排水処理
システムから発生する余剰汚泥や返送汚泥などを用いる
ことができる。性状的に似た廃水を処理しているシステ
ムから得られた活性汚泥であることがより好ましい。活
性汚泥のシーディング方法は、特に限定はされないが、
例えば、排水処理システムの運転開始前に、曝気槽6中
の被処理水に活性汚泥が十分撹拌混合される位置へ添加
する方法、活性汚泥を水、被処理水等であらかじめ希釈
したものを曝気槽6に導入するなどの方法が挙げられ
る。
The activated sludge to be seeded into the aeration tank 6 is not particularly limited. For example, surplus sludge or return sludge generated from an existing wastewater treatment system can be used. More preferably, it is activated sludge obtained from a system treating wastewater having similar properties. The seeding method of the activated sludge is not particularly limited,
For example, before the operation of the wastewater treatment system is started, a method of adding the activated sludge to the treatment water in the aeration tank 6 to a position where the activated sludge is sufficiently stirred and mixed, aeration of the activated sludge previously diluted with water, treatment water, or the like is performed. A method such as introduction into the tank 6 may be used.

【0011】前記分離膜モジュール3は、複数の微細な
孔を有する濾過膜(分離膜)を備えたものであれば特に
限定されるものではなく、例えば、平膜タイプ、中空糸
膜タイプ、管状膜タイプ、袋状膜タイプなどの公知の分
離膜を適用することができ、中でも中空糸膜タイプが望
ましい。また、その材質としては、セルロース、ポリオ
レフィン、ポリスルフォン、ポリフッ化ビニリデン(P
VDF)、ポリ四フッ化エチレン(PTFE)、セラミ
ックス、ポリアクリロニトリル(PAN)などが挙げら
れる。分離膜モジュール3の濾過膜の孔の平均孔径は、
特に限定はされないが、例えば、一般に限外濾過膜と呼
ばれる平均孔径0.001〜0.1μmのもの、または
一般に精密濾過膜と呼ばれる平均孔径0.1〜1μmの
ものを用いることができる。
The separation membrane module 3 is not particularly limited as long as it has a filtration membrane (separation membrane) having a plurality of fine pores. For example, a flat membrane type, a hollow fiber membrane type, a tubular Known separation membranes such as a membrane type and a bag-like membrane type can be applied, and among them, a hollow fiber membrane type is preferable. In addition, as the material, cellulose, polyolefin, polysulfone, polyvinylidene fluoride (P
VDF), polytetrafluoroethylene (PTFE), ceramics, polyacrylonitrile (PAN) and the like. The average pore diameter of the pores of the filtration membrane of the separation membrane module 3 is:
Although not particularly limited, for example, those having an average pore diameter of 0.001 to 0.1 μm generally called an ultrafiltration membrane or those having an average pore diameter of 0.1 to 1 μm generally called a microfiltration membrane can be used.

【0012】分離膜モジュール3には、例えば、図3に
示すような、複数の中空糸で構成される中空糸膜からな
る分離膜21と、分離膜21の両端に設けられた管状支
持体22とを有して概略構成される中空糸分離膜モジュ
ールを適用できる。中空糸には、種々の多孔質かつ管状
の中空糸が使用でき、例えば、セルロース系、ポリオレ
フィン系、ポリビニルアルコール系、ポリメタクリル酸
メチル(PMMA)系、ポリスルフォン系、PAN等の
各種材料からなるものが使用できる。中でも、耐薬品性
の高さや、膜の伸度の高さ等を考慮すると、ポリエチレ
ンやポリプロピレン等のポリオレフィン系の中空糸が好
ましい。また、特に限定されるものではないが、中空糸
の外径は20〜2000μm、孔径は0.01〜1μ
m、空孔率は20〜90%、中空糸膜の膜厚は5〜30
0μmのものが好ましい。
The separation membrane module 3 includes, for example, a separation membrane 21 composed of a hollow fiber membrane composed of a plurality of hollow fibers, and a tubular support 22 provided at both ends of the separation membrane 21 as shown in FIG. And a hollow fiber separation membrane module having a schematic configuration including: As the hollow fiber, various porous and tubular hollow fibers can be used. For example, the hollow fiber is made of various materials such as cellulose, polyolefin, polyvinyl alcohol, polymethyl methacrylate (PMMA), polysulfone, and PAN. Things can be used. Above all, polyolefin-based hollow fibers such as polyethylene and polypropylene are preferable in consideration of high chemical resistance, high elongation of the film, and the like. Further, although not particularly limited, the outer diameter of the hollow fiber is 20 to 2000 μm, and the pore diameter is 0.01 to 1 μm.
m, the porosity is 20 to 90%, and the thickness of the hollow fiber membrane is 5 to 30.
Those having a thickness of 0 μm are preferred.

【0013】また、分離膜21は、表面に親水基を有す
る、いわゆる恒久親水化膜であることが望ましい。分離
膜21の表面が疎水性であると、被処理水中の有機物と
分離膜21表面の間に疎水性相互作用が働き、膜面への
有機物吸着が発生し、これが膜面閉塞につながり、濾過
寿命が短くなりやすく、また、安定して濾過処理を行え
なくなるからである。
The separation membrane 21 is preferably a so-called permanent hydrophilization membrane having a hydrophilic group on the surface. If the surface of the separation membrane 21 is hydrophobic, a hydrophobic interaction acts between the organic matter in the water to be treated and the surface of the separation membrane 21, causing organic matter to be adsorbed on the membrane surface, which leads to membrane surface blockage and filtration. This is because the life is likely to be short and the filtration process cannot be performed stably.

【0014】管状支持体22は、内部に内部路23の形
成された筒状のもので、その一端は閉止され、他端は前
記集水配管8に接続されている。なお、この図3に示す
管状支持体22は円筒状ものであるが、これに限られる
ものではなく、例えば、外形が四角柱状のものでもよ
い。さらに、この管状支持体22の側壁24には、その
長手方向に沿ったスリット25が形成されている。この
スリット25には、分離膜21の端部が挿入されつつ、
充填される密封材で閉塞され、分離膜21は強固に支持
固定される。ここで、分離膜21の端部とは、中空糸の
繊維方向両端部であり、各中空糸の両端部は、管状支持
体22の内部路23内に位置するようになる。
The tubular support 22 has a tubular shape with an internal passage 23 formed therein. One end of the tubular support 22 is closed, and the other end is connected to the water collecting pipe 8. The tubular support 22 shown in FIG. 3 is cylindrical, but is not limited to this. For example, the tubular support 22 may have a square pillar shape. Further, a slit 25 is formed in the side wall 24 of the tubular support 22 along the longitudinal direction thereof. While the end of the separation membrane 21 is inserted into the slit 25,
The separation membrane 21 is closed and firmly supported and fixed by the filled sealing material. Here, the ends of the separation membrane 21 are both ends in the fiber direction of the hollow fiber, and both ends of each hollow fiber are located in the internal passage 23 of the tubular support 22.

【0015】上記密封材は、分離膜21の各中空糸膜を
その端部を開口状態に保ったまま、集束して、スリット
25に固定するとともに、管状支持体22の内部路23
を外部から液密に仕切るもので、エポキシ樹脂、不飽和
ポリエステル樹脂、ポリウレタン等を液状にしたものを
スリット25に充填、硬化させることにより形成され
る。また、1つのスリットに対して2列以上の分離膜を
挿入、固定する、または、1つの管状支持体に2つ以上
のスリットを形成し、各スリットに分離膜を挿入、固定
することによって、1つの中空糸分離膜モジュールに複
数の分離膜21を形成することが可能となる。
The above-mentioned sealing material converges and fixes each hollow fiber membrane of the separation membrane 21 to the slit 25 while keeping the end of the hollow fiber membrane in an open state.
Is liquid-tightly partitioned from the outside, and is formed by filling the slit 25 with an epoxy resin, unsaturated polyester resin, polyurethane, or the like in a liquid state, and curing the slit. Also, by inserting and fixing two or more rows of separation membranes in one slit, or by forming two or more slits in one tubular support, and inserting and fixing the separation membrane in each slit, A plurality of separation membranes 21 can be formed in one hollow fiber separation membrane module.

【0016】このような中空糸分離膜モジュールは、汚
泥などによって複数の中空糸が集束、固着して一体化さ
れにくい。そのため、濾過処理中にエアースクラビング
によって気泡が1本1本の中空糸間に入り込みやすく、
良好な洗浄効果が期待でき、膜分離活性汚泥処理方法を
用いた排水処理システムには好適である。また、このよ
うな中空糸分離膜モジュールは、曝気槽6中に複数個配
置することが可能である。中空糸分離膜モジュールを複
数個配置することによって、処理性能を向上させること
ができる。
In such a hollow fiber separation membrane module, a plurality of hollow fibers are hardly bundled and fixed by sludge or the like, and thus are difficult to be integrated. Therefore, air bubbles easily enter between the hollow fibers by air scrubbing during the filtration process,
A good cleaning effect can be expected, and it is suitable for a wastewater treatment system using a membrane separation activated sludge treatment method. A plurality of such hollow fiber separation membrane modules can be arranged in the aeration tank 6. By arranging a plurality of hollow fiber separation membrane modules, the processing performance can be improved.

【0017】前記散気装置5は、多数の細孔の形成され
た中空体とされ、この散気装置5内に空気を送り込む圧
空ポンプ4に接続されており、圧空ポンプ4を稼働させ
ることによって、分離膜モジュール3に空気を気泡の状
態として送り込むことができるようになっている。この
散気装置5を用いることにより、曝気槽6中の活性汚泥
に酸素を送り込むと同時に、分離膜モジュール3の分離
膜にエアースクラビング処理、すなわち散気装置5から
発散し、上昇する気泡およびそれによって発生する水流
によって分離膜を揺動させ、分離膜の膜表面に付着した
汚泥を取り除く処理を施すことができ、固液分離能力を
長時間にわたって高く維持することができる。
The air diffuser 5 is a hollow body having a large number of pores, and is connected to a pneumatic pump 4 for feeding air into the air diffuser 5. The air can be sent to the separation membrane module 3 in the form of air bubbles. By using the air diffuser 5, oxygen is sent into the activated sludge in the aeration tank 6, and at the same time, the separation membrane of the separation membrane module 3 is subjected to air scrubbing, that is, bubbles rising from the air diffuser 5 and rising. Thus, the separation membrane can be swung by the water flow generated to remove sludge adhering to the membrane surface of the separation membrane, and the solid-liquid separation ability can be maintained high for a long time.

【0018】また、前記散気装置5によるエアースクラ
ビング処理を考慮すると、分離膜の膜面が鉛直方向に沿
うように分離膜モジュール3を配置することが望まし
い。膜面が鉛直方向に沿うように配置することで、その
下方から上昇する気泡がすべての分離膜の膜面全体に対
し均一に作用し、かつ円滑に曝気槽6上方に通り抜けや
すくなるからである。これに対して分離膜が水平に寝た
状態に分離膜モジュール3を配置すると、発散した気泡
は最下部に配置された分離膜に当たった後は、その分離
膜に沿って水平方向外方に向かって散ってしまい、上部
に配置された分離膜に対して有効にエアースクラビング
処理を施すことができなくなってしまう。
Further, in consideration of the air scrubbing process by the air diffuser 5, it is desirable to arrange the separation membrane module 3 so that the membrane surface of the separation membrane is along the vertical direction. This is because, by arranging the membrane surface along the vertical direction, bubbles rising from below act uniformly on the entire membrane surface of all the separation membranes, and easily pass over the aeration tank 6 smoothly. . On the other hand, if the separation membrane module 3 is placed in a state where the separation membrane is lying horizontally, the diverged air bubbles hit the separation membrane arranged at the bottom, and then move outward along the separation membrane in the horizontal direction. As a result, it becomes impossible to effectively perform the air scrubbing process on the separation membrane disposed on the upper portion.

【0019】また、排水処理システムには、薬液タンク
と、一端が薬液タンクに連通し、他端が前記集水配管8
に連通した薬液供給管とが設けられていてもよい。この
ような薬液タンクには、分離膜の洗浄を行うための、N
aOCl、NaOH、HCl等の水溶液からなる薬液を
入れることが可能である。
In the wastewater treatment system, a chemical tank and one end communicate with the chemical tank, and the other end is connected to the water collecting pipe 8.
May be provided with a chemical liquid supply pipe communicating with the liquid medicine supply pipe. In such a chemical tank, N.sub.2 for cleaning the separation membrane is provided.
A chemical solution consisting of an aqueous solution of aOCl, NaOH, HCl or the like can be added.

【0020】このような膜分離活性汚泥処理方法にあっ
ては、排水処理システムの運転初期段階であっても、曝
気槽6において被処理水中のBOD成分を十分に分解す
ることができるので、分離膜モジュール3の膜面へのB
OD成分の過度な吸着が防止され、安定して固液分離処
理が行われる。
In such a membrane separation activated sludge treatment method, the BOD component in the water to be treated can be sufficiently decomposed in the aeration tank 6 even in the initial stage of the operation of the wastewater treatment system. B on the membrane surface of membrane module 3
Excessive adsorption of the OD component is prevented, and the solid-liquid separation process is performed stably.

【0021】[0021]

【実施例】[実施例1]図1の排水処理システムを用
い、運転開始前に容量1m3 の曝気槽6へ10000m
g/lの活性汚泥300lをシーディングし、曝気槽6
内のMLSS濃度を3000mg/lとした後に、BO
D成分500mg/l、SS100mg/lの被処理水
の処理を行った。処理水量は1m3 /日であり、分離膜
モジュール3としては、三菱レイヨン(株)製ステラポ
アーL、UMF824LF(中空糸分離膜モジュール、
膜面積8m2 、孔径0.1μm)を使用した。運転開始
直後、10日後、30日後および90日後における分離
膜モジュール3の吸引圧(差圧)の測定結果を表1に示
す。
EXAMPLES Example 1 using the wastewater treatment system of FIG. 1, to the aeration tank 6 of capacity 1 m 3 before starting operation 10000m
g / l of activated sludge was seeded into aeration tank 6
After the MLSS concentration in the
Treatment of the water to be treated was performed at 500 mg / l for the D component and 100 mg / l for SS. The treated water amount is 1 m 3 / day, and the separation membrane module 3 is manufactured by Mitsubishi Rayon Co., Ltd. Stellapore L, UMF824LF (hollow fiber separation membrane module,
A membrane area of 8 m 2 and a pore diameter of 0.1 μm) were used. Table 1 shows the measurement results of the suction pressure (differential pressure) of the separation membrane module 3 immediately after the start of the operation, 10, 30, and 90 days later.

【0022】[比較例1]運転開始前に活性汚泥のシー
ディングを行わなかった以外は、実施例1と同様に行っ
た。結果を表1に示す。活性汚泥のシーディングを行わ
ない場合、膜面の目詰まりによる吸引圧の上昇が見られ
た。
[Comparative Example 1] The same operation as in Example 1 was performed, except that seeding of activated sludge was not performed before the start of operation. Table 1 shows the results. When the activated sludge was not seeded, an increase in suction pressure due to clogging of the membrane surface was observed.

【0023】[0023]

【表1】 [Table 1]

【0024】[0024]

【発明の効果】以上説明したように、本発明の膜分離活
性汚泥処理方法は、活性汚泥中の微生物によって被処理
水の有機物を分解する生物処理と、分離膜モジュールに
よる固液分離処理とを同一の槽内で行う膜分離活性汚泥
処理方法において、最初の運転開始までに、あらかじめ
前記槽内の被処理水のMLSS濃度が2000mg/l
以上となるように前記槽内に活性汚泥を加えておく方法
であるので、分離膜モジュールの膜面への有機物の過度
な吸着を防ぎ、分離膜モジュール内外の差圧の上昇を抑
え、安定して固液分離処理を行うことができる。
As described above, the membrane separation activated sludge treatment method of the present invention comprises a biological treatment in which microorganisms in activated sludge decompose organic matter in water to be treated and a solid-liquid separation treatment by a separation membrane module. In the membrane separation activated sludge treatment method performed in the same tank, the MLSS concentration of the water to be treated in the tank is set to 2000 mg / l before the first operation.
Since activated sludge is added to the tank as described above, excessive adsorption of organic substances to the membrane surface of the separation membrane module is prevented, the rise in the differential pressure inside and outside the separation membrane module is suppressed, and the To perform a solid-liquid separation process.

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

【図1】 膜分離活性汚泥処理方法を用いた排水処理シ
ステムの一例を示す概略図である。
FIG. 1 is a schematic diagram showing an example of a wastewater treatment system using a membrane separation activated sludge treatment method.

【図2】 中空糸分離膜モジュールの一例を示す斜視図
である。
FIG. 2 is a perspective view showing an example of a hollow fiber separation membrane module.

【図3】 従来の沈降分離を用いた排水処理システムの
一例を示す概略図である。
FIG. 3 is a schematic diagram showing an example of a conventional wastewater treatment system using settling separation.

【符号の説明】[Explanation of symbols]

3 分離膜モジュール 6 曝気槽 3 Separation membrane module 6 Aeration tank

───────────────────────────────────────────────────── フロントページの続き Fターム(参考) 4D006 GA06 GA07 HA15 JA06Z JA19Z JA53Z KB22 KC14 MA01 MA22 MB09 MC11 MC22 MC23 MC29 MC30 MC33 MC36 MC39 MC62 PB08 PC64 4D028 AA02 BC03 BC17 BD16 CA05 CB02  ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D006 GA06 GA07 HA15 JA06Z JA19Z JA53Z KB22 KC14 MA01 MA22 MB09 MC11 MC22 MC23 MC29 MC30 MC33 MC36 MC39 MC62 PB08 PC64 4D028 AA02 BC03 BC17 BD16 CA05 CB02

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 活性汚泥中の微生物によって被処理水の
有機物を分解する生物処理と、分離膜モジュールによる
固液分離処理とを同一の槽内で行う膜分離活性汚泥処理
方法において、最初の運転開始までに、あらかじめ前記
槽内の被処理水の混合液浮遊物質(MLSS)濃度が2
000mg/l以上となるように前記槽内に活性汚泥を
加えておくことを特徴とする膜分離活性汚泥処理方法。
1. A membrane separation activated sludge treatment method in which a biological treatment for decomposing organic substances of water to be treated by microorganisms in activated sludge and a solid-liquid separation treatment by a separation membrane module are performed in the same tank. Before the start, the concentration of the suspended solids (MLSS) of the liquid to be treated in the tank is 2
Activated sludge is added to the tank so as to have a concentration of 000 mg / l or more.
JP36823498A 1998-12-24 1998-12-24 Activated sludge treatment by membrane separation Withdrawn JP2000189993A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP36823498A JP2000189993A (en) 1998-12-24 1998-12-24 Activated sludge treatment by membrane separation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP36823498A JP2000189993A (en) 1998-12-24 1998-12-24 Activated sludge treatment by membrane separation

Publications (1)

Publication Number Publication Date
JP2000189993A true JP2000189993A (en) 2000-07-11

Family

ID=18491298

Family Applications (1)

Application Number Title Priority Date Filing Date
JP36823498A Withdrawn JP2000189993A (en) 1998-12-24 1998-12-24 Activated sludge treatment by membrane separation

Country Status (1)

Country Link
JP (1) JP2000189993A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20120112108A (en) 2011-03-29 2012-10-11 쿠리타 고교 가부시키가이샤 Method of treating organic waste water by membrane separator activated sludge device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20120112108A (en) 2011-03-29 2012-10-11 쿠리타 고교 가부시키가이샤 Method of treating organic waste water by membrane separator activated sludge device

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