JP2006055852A - Cleaning method and equipment for filter element - Google Patents

Cleaning method and equipment for filter element Download PDF

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JP2006055852A
JP2006055852A JP2005285179A JP2005285179A JP2006055852A JP 2006055852 A JP2006055852 A JP 2006055852A JP 2005285179 A JP2005285179 A JP 2005285179A JP 2005285179 A JP2005285179 A JP 2005285179A JP 2006055852 A JP2006055852 A JP 2006055852A
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water
filtration
filter
filter body
backwash
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JP4335193B2 (en
JP2006055852A5 (en
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Yousei Katsura
甬生 葛
Toshihiro Tanaka
俊博 田中
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Ebara Corp
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    • 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

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method and equipment for a filter element of a solid-liquid separator of biologically treated waste water which makes it possible to stably obtain a filter Flux nearly similar to an initial value for a long period of time in cleaning the filter element by idle cleaning in filtration using the water-permeable filter element. <P>SOLUTION: The cleaning method for the filter element is a solid-liquid separation method of filtering the liquid mixed with the activated sludge from a bio-reaction tank for aerobically treating raw water by the activated sludge by forming a dynamic filter layer of sludge on the surface of the filter element in a filtration separating tank installed with the water-permeable filter element to obtain filtrate and returning the waste water of back washing to the bio-reaction tank after completely returning the liquid mixed with the activated sludge to the bio-reaction tank in washing the filter element or at the point of time the filtration separating tank is filled with the filtrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、汚水処理に関するもので、特に活性汚泥の固液分離や余剰汚泥の濃縮等に使用する通水性ろ過体の洗浄に関するものであり、有機性工業廃水や生活排水等の処理に用いることができる通水性ろ過体の洗浄方法及び装置に関する。   The present invention relates to sewage treatment, and particularly relates to washing of water-permeable filter used for solid-liquid separation of activated sludge and concentration of excess sludge, and is used for treatment of organic industrial wastewater and domestic wastewater. The present invention relates to a method and apparatus for cleaning a water-permeable filter.

従来、活性汚泥による水処理では、処理水を得るためには活性汚泥の固液分離を行わなければならない。通常では、活性汚泥を沈澱池に導入させ、重力沈降によって、汚泥を沈降させ、上澄液を処理水として沈澱池から流出させる方法が用いられる。この場合、活性汚泥を沈降させるため十分に広い沈降面積を有し、かつ十分な長さの滞留時間を確保できる沈澱池が必要であり、処理装置の大型化と設置容積の増大要因となっている。また、活性汚泥がバルキング等、沈降性の悪化した場合、沈澱池より汚泥が流出し、処理水の悪化を招く。   Conventionally, in water treatment with activated sludge, solid sludge separation of activated sludge has to be performed in order to obtain treated water. Normally, a method is used in which activated sludge is introduced into a sedimentation basin, the sludge is sedimented by gravity sedimentation, and the supernatant is discharged from the sedimentation basin as treated water. In this case, there is a need for a sedimentation basin that has a sufficiently large sedimentation area to settle the activated sludge and can secure a sufficiently long residence time, which is a factor in increasing the size of the processing apparatus and increasing the installation volume. Yes. Moreover, when activated sludge deteriorates sedimentation property, such as bulking, sludge flows out from a sedimentation basin and causes deterioration of treated water.

近年、沈澱池に代わって膜分離による活性汚泥の固液分離を行う手法も用いられている。この場合、固液分離用膜として、一般的に精密ろ過膜や限外ろ過膜が用いられる。
その際、ろ過分離手段としてポンプによる吸引や加圧が必要であり、通常数十kPa〜数百kPaの圧力で行うため、ポンプによる動力が大きく、ランニングコストの増大となっている。また、膜分離でSSの全くない清澄な処理水が得られる一方、透過Fluxが低く、膜汚染を防止するため、定期的に薬洗する必要がある。
In recent years, a method of performing solid-liquid separation of activated sludge by membrane separation instead of a sedimentation basin has been used. In this case, a microfiltration membrane or an ultrafiltration membrane is generally used as the solid-liquid separation membrane.
At that time, suction or pressurization by a pump is required as a filtration separation means, and since it is usually performed at a pressure of several tens of kPa to several hundred kPa, the power of the pump is large and the running cost is increased. In addition, clear treated water having no SS is obtained by membrane separation, while permeation flux is low, and it is necessary to periodically wash the medicine in order to prevent membrane contamination.

最近、膜分離による活性汚泥の固液分離法の一方法として、曝気槽に不織布等の通気性シートからなるろ過体を浸漬させ、低い水頭圧でろ過水を得る方法が提案されている。この方法では、ろ過体表面に汚泥のダイナミックろ過層が形成するように活性汚泥混合液の流れ設定したろ過分離手段で清澄なろ過水を得るものである。この方法では、ろ過Flux低下時にろ過体を洗浄する手段としては、ろ過体下部に設置した散気管より曝気するようにしており、それによりろ過体表面に形成された汚泥のダイナミックろ過層が容易に剥離するので、安定したろ過Fluxが得られるとしている。   Recently, as a method of solid-liquid separation of activated sludge by membrane separation, a method has been proposed in which a filter body made of a breathable sheet such as a nonwoven fabric is immersed in an aeration tank to obtain filtered water with a low head pressure. In this method, clear filtered water is obtained by filtration separation means in which the flow of the activated sludge mixed liquid is set so that a sludge dynamic filtration layer is formed on the surface of the filter body. In this method, as a means for washing the filter body when the filtration flux is lowered, aeration is performed from an air diffuser installed at the lower part of the filter body, so that a sludge dynamic filtration layer formed on the surface of the filter body can be easily obtained. Since it exfoliates, it is said that a stable filtered flux is obtained.

しかし、前記ろ過体を曝気槽に浸漬しておき、ろ過Flux低下時にだけ空洗による洗浄を行う方式では、ろ過Fluxが徐々に低下することが認められた。すなわち、処理日数の増加にともない、空洗直後のろ過Fluxが初期値に比べ徐々に低下した。また、初期値に対する割合を示す回復率も同様に低下し、空洗回数の増加にともない、その低下の程度が大きくなる。ろ過体を曝気槽に浸漬した場合、ろ過体表面に形成された汚泥のダイナミックろ過層が空洗によって完全に剥離されなかった時、微細な汚泥フロックがろ過体表面に付着し、長期ろ過にともない、付着汚泥の微細化でろ過体表面の閉塞を引き起こす。また、空洗直後からダイナミックろ過層が形成されるまでの初期ろ過において、ろ過体表面を通過した汚泥が内部に堆積し、時間経過とともに徐々に濃縮されるため、ろ過抵抗が増大し、ろ過Fluxを著しく低下させる原因となる。
この結果、空洗では良好な洗浄効果が得られず、経過時間とともにろ過Fluxの低下が大きくなり、安定した処理を得ることが困難となる。
However, in the method in which the filter body is immersed in an aeration tank and washing is performed by washing with air only when the filtration flux is lowered, it is recognized that the filtration flux gradually decreases. That is, with the increase in the number of treatment days, the filtration flux immediately after the flushing gradually decreased compared to the initial value. In addition, the recovery rate indicating the ratio with respect to the initial value is similarly decreased, and the degree of the decrease is increased as the number of times of washing is increased. When the filter is immersed in an aeration tank, when the sludge dynamic filtration layer formed on the filter surface is not completely removed by air washing, fine sludge flocs adhere to the filter surface and accompany long-term filtration. The surface of the filter body is clogged by the refinement of the attached sludge. In addition, in the initial filtration from immediately after the washing to the formation of the dynamic filtration layer, the sludge that has passed through the surface of the filter body is accumulated inside and gradually concentrated over time, so that the filtration resistance increases and the filtration flux Cause a significant decrease in
As a result, a good cleaning effect cannot be obtained by empty washing, and the drop in the filtration flux increases with the elapsed time, making it difficult to obtain a stable treatment.

本発明は、このような従来の課題に鑑みてなされたものであり、通水性ろ過体の内部に対し水逆洗を行い、初期値とほぼ同様なろ過Fluxを、長期間にわたって安定して得られ、しかも、安定した水質も得ることができる生物処理汚水の固液分離装置のろ過体の洗浄方法及び装置を得ることを課題とする。   The present invention has been made in view of the above-described conventional problems, and the inside of a water-permeable filter body is back-washed with water to obtain a filtration flux almost the same as the initial value stably over a long period of time. In addition, an object of the present invention is to obtain a method and an apparatus for cleaning a filter body of a solid-liquid separation apparatus for biologically treated sewage that can obtain stable water quality.

本発明者等は、前記の課題により、処理時間の経過と関係なく、常にろ過体の表面に均一なダイナミックろ過層を形成する方法について種々研究した。
そして、ろ過体の内部に対して処理水槽からのろ過水又は薬品洗浄液で逆洗すれば、通常の空洗では完全に剥離できなかったろ過体表面及び内部の微細なフロック、あるいは生物スラムも容易に洗い落とすことが可能になることが確認された。
本発明は、このような知見に基づいてなされたものであり、次の構成からなるものである。
The present inventors have made various studies on methods for always forming a uniform dynamic filtration layer on the surface of the filter body regardless of the lapse of processing time due to the above-mentioned problems.
And if the inside of the filter body is back-washed with filtered water from the treatment water tank or chemical cleaning liquid, the surface of the filter body and fine flocs inside the body that could not be completely removed by normal air washing, or biological slums are easy. It was confirmed that it was possible to wash it off.
The present invention has been made based on such knowledge and has the following configuration.

(1)原水を流入させて好気的に活性汚泥による処理を行う生物反応槽からの活性汚泥混合液を、通水性ろ過体を設置したろ過分離槽に供給し、該ろ過分離槽で該ろ過体表面に汚泥のダイナミックろ過層を形成させてろ過を行ってろ過水を得、ろ過後の活性汚泥混合液を生物反応槽に返送する活性汚泥混合液の固液分離法において、該ろ過体洗浄時、ろ過分離槽内の活性汚泥混合液を生物反応槽に完全に返送した後、あるいはろ過分離槽にろ過水を満たした時点で該ろ過体の内部に対し水逆洗し、逆洗排水を生物反応槽に返送することを特徴とするろ過体の洗浄方法。
(2)ろ過体内部への水逆洗は、ろ過体上部の逆洗ラインにろ過水あるいは薬品洗浄液を流入させ、ろ過体下部の取水ラインより逆洗排水を排出することを特徴とする前記(1)記載のろ過体の洗浄方法。
(1) The activated sludge mixed liquid from the biological reaction tank that performs the treatment with activated sludge aerobically by flowing raw water is supplied to the filtration separation tank in which the water-permeable filter is installed, and the filtration separation tank is used for the filtration. In the solid-liquid separation method of the activated sludge mixed liquid, the sludge dynamic filtration layer is formed on the body surface to obtain filtered water by filtration, and the filtered activated sludge mixed liquid is returned to the biological reaction tank. After the activated sludge mixture in the filtration / separation tank is completely returned to the biological reaction tank, or when the filtration / separation tank is filled with filtered water, the inside of the filter body is back-washed with water, A method for washing a filter body, which is returned to a biological reaction tank.
(2) Water backwashing into the filter body is characterized in that filtered water or chemical cleaning liquid is allowed to flow into the backwash line at the top of the filter body, and backwash drainage is discharged from the water intake line at the bottom of the filter body. 1) The washing | cleaning method of the filter body of description.

(3)原水を流入させて好気的に活性汚泥による処理を行う生物反応槽からの活性汚泥混合液を供給され、通水性ろ過体を有し、該ろ過体によるろ過に際して該ろ過体表面に汚泥のダイナミックろ過層を形成してろ過水を得るろ過分離槽を用いる活性汚泥混合液の固液分離装置において、該ろ過分離槽内に浸漬されたダイナミックろ過層を形成した通水性ろ過体の下方に配置された空洗用の空洗散気管と、ろ過分離槽内の活性汚泥混合液の生物反応槽への返送用の配管、あるいはろ過分離槽にろ過水を満たすための処理水槽からの配管と、ろ過分離槽内の活性汚泥混合液を生物反応槽に完全に返送した後、あるいはろ過分離槽にろ過水を満たした時点で作動する、処理水槽からの該ろ過体の内部に処理水を送るよう接続された逆洗水ラインと、該ろ過体の内部からの逆洗排水を排出するための逆洗排水ラインとからなる逆洗ユニットを有することを特徴とするろ過体の洗浄装置。
(4)逆洗ユニットは、ろ過体支持部の上部の逆洗水ラインからろ過水あるいは薬品洗浄液を流入させ、下部の逆洗排水ラインより逆洗排水あるいは排液を排出するとともに、ろ過体と接触するように設けた通水性スペーサからろ過体内部に対し逆洗を行うように構成されていることを特徴とする前記(3)記載のろ過体の洗浄装置。
(3) The activated sludge mixed liquid is supplied from a biological reaction tank in which raw water is introduced and aerobically treated with activated sludge, and has a water-permeable filter body. In a solid-liquid separation device for an activated sludge mixed liquid using a filtration separation tank that forms a sludge dynamic filtration layer to obtain filtered water, below the water-permeable filter body that has formed a dynamic filtration layer immersed in the filtration separation tank An air-washing air diffuser for air-washing and piping for returning the activated sludge mixed liquid in the filtration / separation tank to the biological reaction tank, or piping from the treated water tank to fill the filtration / separation tank with filtered water After the activated sludge mixed liquid in the filtration separation tank is completely returned to the biological reaction tank or when the filtration separation tank is filled with filtered water, the treated water is introduced into the filter body from the treatment water tank. With backwash water line connected to send Cleaning device of the filtering body and having a backwash unit comprising a backwash drain line for discharging the backwash waste water from the interior of said filtration body.
(4) The backwash unit allows filtered water or chemical cleaning liquid to flow from the backwash water line at the top of the filter support part, and discharges backwash drainage or drainage from the bottom backwash drainage line. The apparatus for washing a filter body according to (3), wherein the filter body is back-washed from a water-permeable spacer provided in contact with the inside of the filter body.

本発明によれば、通水性ろ過体を用い、ろ過体表面に汚泥のダイナミックろ過層を形成してろ過水を得る汚泥混合液の固液分離方法において、ろ過分離槽に浸漬するろ過体モジュールに対し、定期的にろ過分離槽内の汚泥混合液を一旦全部生物反応槽へ返送した後、処理水槽のろ過水を用い、ろ過体モジュール内部に水逆洗を行えば、ろ過体表面に付着した微細な汚泥粒子を容易に落とすことができ、かつ、ろ過体内部に堆積した汚泥を、逆洗によって外部に排出することができる。この結果、ろ過体表面の汚泥微粒子閉塞による表面抵抗及び、ろ過体内部汚泥堆積による内部抵抗のいずれも低減することができ、ろ過Fluxがほぼ初期値に回復する。   According to the present invention, in a solid-liquid separation method of a sludge mixed liquid that uses a water-permeable filter and forms a sludge dynamic filtration layer on the surface of the filter to obtain filtrate, a filter module that is immersed in a filtration separation tank. On the other hand, after all the sludge mixed liquid in the filtration separation tank has been returned to the biological reaction tank on a regular basis, using the filtered water of the treated water tank, if the water is back-washed inside the filter module, it adheres to the filter surface. Fine sludge particles can be easily dropped, and sludge accumulated in the filter body can be discharged to the outside by backwashing. As a result, both the surface resistance due to the sludge fine particle blockage on the surface of the filter body and the internal resistance due to the accumulation of sludge inside the filter body can be reduced, and the filtration flux recovers to almost the initial value.

水逆洗は、ろ過体上部の逆洗ラインにろ過水を注入し、下部の取水ラインより逆洗排水を排出し、生物反応槽に返送される方式により、ろ過体内部の堆積汚泥を容易に排出でき、該汚泥を再度ろ過体内部に堆積しないため、常時安定したろ過Fluxが得られる。さらに水逆洗時、薬品洗浄液を逆洗水として用いれば、ろ過体表面に生物スラムが付着しても容易に洗い落とすことができる。すなわち、長期ろ過にともなう生物スラム付着による、ろ過Fluxの低下を抑制することができる。   In water backwashing, filtered water is injected into the backwash line at the top of the filter body, drained backwash water is discharged from the intake line at the bottom, and returned to the biological reaction tank to facilitate sedimentation of the sludge inside the filter body Since the sludge can be discharged and the sludge is not deposited again inside the filter body, a stable filtration flux can be obtained at all times. Further, when the chemical cleaning liquid is used as the backwashing water during the water backwashing, even if the biological slam adheres to the surface of the filter body, it can be easily washed off. That is, it is possible to suppress the decrease in the filtration flux due to the biological slam adhesion accompanying long-term filtration.

本発明によれば、通水性ろ過体(以下単に「ろ過体」とも言う)を用い、ろ過体表面に汚泥のダイナミックろ過層を形成してろ過水を得る汚泥混合液の固液分離方法において、ろ過分離槽に浸漬する通水性ろ過体モジュールに対し、定期的にろ過分離槽内の汚泥混合液を一旦全部生物反応槽へ返送した後、あるいはろ過分離槽にろ過水を満たした時点で、処理水槽のろ過水を用い、ろ過体モジュール内部に対し水逆洗を行えば、ろ過体表面に付着した微細な汚泥粒子を容易に落とすことができ、かつろ過体内部に堆積した汚泥を逆洗によって外部に排出することができる。
この結果、ろ過体表面に汚泥微粒子閉塞による表面抵抗及び、ろ過体内部汚泥堆積による内部抵抗のいずれも低減することができ、ろ過Fluxがほぼ初期値に回復する。
According to the present invention, in a solid-liquid separation method of a sludge mixed liquid that uses a water-permeable filter body (hereinafter also simply referred to as “filter body”) and forms a sludge dynamic filtration layer on the surface of the filter body to obtain filtered water, Treat the water-permeable filter module immersed in the filtration / separation tank after returning the sludge mixture in the filtration / separation tank to the biological reaction tank or filling the filtration / separation tank with filtered water. By using the filtered water in the aquarium and backwashing the inside of the filter body module, fine sludge particles adhering to the surface of the filter body can be easily removed, and sludge accumulated inside the filter body can be removed by backwashing. It can be discharged to the outside.
As a result, both the surface resistance due to sludge fine particle blockage on the filter body surface and the internal resistance due to accumulation of sludge inside the filter body can be reduced, and the filtration flux is almost restored to the initial value.

なお、ここでいう「水逆洗」とは、通水性ろ過体表面からろ過体内部へ通るろ過に対し、ろ過体内部の一端へ洗浄水を供給してろ過体内部を通過させて洗浄を行い、ろ過体内部の他端から洗浄廃水を排出する操作をいう。
本発明において、ろ過体内部に対して水逆洗を行う目的は、次の2点にある。
(イ)洗浄水をろ過体内部からろ過体の表面を通過させ、表面の内部に付着した微細な汚泥フロックを剥離させること。(ロ)ろ過体内部に侵入した汚泥を内部に堆積しないうちに洗浄水とともに外部に排出すること。この後者の場合、侵入汚泥を内部からろ過体表面を通過させて外部に出すことは困難であり、不合理であるため、上記した水逆洗の手段が有効と考えて、本発明方法を完成したのである。
In addition, “water backwashing” as used herein refers to the filtration that passes from the surface of the water-permeable filter body to the inside of the filter body, and supplies the wash water to one end inside the filter body to allow the inside of the filter body to be washed. An operation for discharging washing wastewater from the other end inside the filter body.
In the present invention, there are the following two points for the purpose of backwashing the inside of the filter body.
(B) The cleaning water is allowed to pass from the inside of the filter body through the surface of the filter body, and the fine sludge floc adhering to the inside of the surface is peeled off. (B) Discharge sludge that has entered the filter body to the outside together with cleaning water before it accumulates inside. In this latter case, it is difficult and unreasonable to pass the invading sludge from the inside through the surface of the filter body, and it is unreasonable. It was.

本発明においては、水逆洗を行う際のろ過分離槽の状態として、次の2種の場合を設定している。
1)ろ過分離槽内の汚泥混合液を生物反応槽へ完全に返送した場合(時点)。
2)ろ過分離槽内にろ過水を満たした場合。
このケース1)の場合においては、ろ過体内部にろ過水の残留がなく、ほぼ空洞であるため、ろ過体表面にろ過分離槽内に水を満たした場合に生じる水の抵抗を受けず、内部に流れる逆洗水の流速が大きく、ろ過体内部に堆積している汚泥、及びろ過体内部表面に付着している汚泥を効率よく剥離させ、完全に外部つまり生物反応槽に排出することができる。また、この場合、逆洗水量はろ過体内部のろ過水室容積の数倍程度であれば、良好な洗浄効果が得られるので、少ない逆洗水量で対応できる。
また、ケース2)の場合においては、ろ過分離槽内に水を満たしたことで、ろ過体表面に付着した微細汚泥フロックを溶解させ、ろ過体表面への付着力を弱める効果がある。この時に逆洗水をろ過体内部に供給すれば、ろ過体表面に付着した汚泥を容易に剥離させ、逆洗排水と共に生物反応槽に排出することができる。また、ろ過体内部の堆積汚泥もろ過分離槽内のろ過水がろ過体内部への侵入により希釈され、逆洗水の供給で堆積した汚泥を逆洗排水と共に容易に生物反応槽に排出することができる。
In the present invention, the following two cases are set as the state of the filtration separation tank when performing water backwashing.
1) When the sludge mixture in the filtration separation tank is completely returned to the biological reaction tank (time point).
2) When the filtration separation tank is filled with filtered water.
In the case of this case 1), there is no residue of filtered water inside the filter body, and it is almost hollow, so it is not subject to the resistance of water that occurs when the filter separation tank is filled with water. The flow rate of backwash water flowing through the filter is large, and the sludge accumulated inside the filter body and the sludge adhering to the inner surface of the filter body can be efficiently separated and completely discharged to the outside, that is, the biological reaction tank. . In this case, if the amount of backwash water is about several times the volume of the filtrate water chamber inside the filter body, a good cleaning effect can be obtained, so that it can be handled with a small amount of backwash water.
In case 2), the filtration separation tank is filled with water, so that fine sludge flocs adhering to the surface of the filter body are dissolved, and the adhesive force on the surface of the filter body is weakened. At this time, if backwash water is supplied to the inside of the filter body, sludge adhering to the surface of the filter body can be easily peeled off and discharged into the biological reaction tank together with the backwash waste water. The sludge accumulated in the filter body is also diluted by the infiltration of the filtration separation tank into the filter body, and the sludge accumulated by the backwash water supply is easily discharged into the biological reaction tank along with the backwash drainage. Can do.

水逆洗は、ろ過体上部の逆洗ラインにろ過水を注入し、下部の取水ラインより逆洗排水を排出し、生物反応槽に返送される構造により、ろ過体内部の堆積汚泥を容易に排出でき、該汚泥を再度ろ過体内部に堆積しないため、常時安定したろ過Fluxが得られる。
さらに水逆洗時、薬品洗浄液を逆洗水として用いれば、ろ過体表面に生物スラムが付着しても容易に洗い落とすことができる。長期ろ過にともなう生物スラム付着によるろ過Fluxの低下を抑制することができる。
薬品洗浄液としては、次亜塩素酸水溶液、アルカリ水溶液、酸水溶液、あるいはオゾン水溶液、過酸化水素水溶液等のいずれを用いることもできる。薬品洗浄液の選定及び洗浄頻度は処理対象汚泥、汚染状況より判断し、数日から数ヶ月に1回程度で行うのが好ましい。
Water backwashing injects filtered water into the backwash line at the top of the filter body, discharges backwash wastewater from the bottom water intake line, and returns it to the biological reaction tank, making it easy to remove accumulated sludge inside the filter body. Since the sludge can be discharged and the sludge is not deposited again in the filter body, a stable filtration flux can be obtained at all times.
Further, when the chemical cleaning liquid is used as the backwash water during the water backwashing, even if the biological slam adheres to the surface of the filter body, it can be easily washed off. The fall of the filtration flux by the biological slam adhesion accompanying long-term filtration can be suppressed.
As the chemical cleaning solution, any of hypochlorous acid aqueous solution, alkaline aqueous solution, acid aqueous solution, ozone aqueous solution, hydrogen peroxide aqueous solution and the like can be used. The selection of chemical cleaning liquid and the frequency of cleaning are determined from the sludge to be treated and the state of contamination, and it is preferable to carry out the cleaning once every few days to several months.

通水性ろ過体としては、通水性で耐圧性の多孔性表面をもつシート状体であれば、不織布、織布、金属網等のいずれを用いても同様な効果が得られる。そして、ろ過体形状としては、平面型、円筒型、中空型のいずれを用いることも可能であり、複数個を束ねてモジュールろ過体として用いることが可能である。
また、ろ過体モジュール構造としては、通水性ろ過体を保持する支持板は、できるだけ中空型であることが望ましい。該ろ過体モジュール上部に逆洗水が支持板内部に注入できる逆洗水流入管を有し、ろ過水を得る取水管は、該ろ過体モジュール下部に設置されており、逆洗排水の排出ラインが取水管に接続され、逆洗時はバブルの切り替えによって、逆洗排水が生物処理槽に返送できる構造であるものが望ましい。
通水性ろ過体によるろ過分離できる対象汚泥としては、活性汚泥、凝集汚泥、初沈汚泥等の何れも可能である。また、SSの高い排水、河川水等の固液分離として用いることも可能である。
If the water-permeable filter is a sheet-like body having a water-permeable and pressure-resistant porous surface, the same effect can be obtained by using any of nonwoven fabric, woven fabric, metal net, and the like. And as a filter body shape, any of a plane type, a cylindrical type, and a hollow type can be used, and a plurality can be bundled and used as a module filter body.
Moreover, as a filter body module structure, it is desirable for the support plate holding a water-permeable filter body to be as hollow as possible. There is a backwash water inflow pipe through which the backwash water can be injected into the support plate at the top of the filter module, and the intake pipe for obtaining filtered water is installed at the bottom of the filter module, and the discharge line for backwash drainage is It is desirable to have a structure that is connected to a water intake pipe and can return backwash wastewater to the biological treatment tank by switching bubbles during backwashing.
As the target sludge that can be filtered and separated by the water-permeable filter body, any of activated sludge, agglomerated sludge, initial settling sludge, and the like are possible. It can also be used for solid-liquid separation of drainage with high SS and river water.

図面により、本発明をより具体的に説明する。
図1は、団地下水に対する本発明による処理法の一例をフローシートで示すものである。
図1に示す如く、流入原水1が生物反応槽2に流入し、生物反応槽2において曝気ブロワ4より散気管3へ空気を供給することにより活性汚泥による好気処理を行う。活性汚泥混合液が、汚泥供給ポンプ5よりろ過分離槽10に供給される。ろ過分離槽10に流入した活性汚泥混合液は、通水性ろ過体11より水頭圧△Hでろ過され、ろ過水取水弁17を開放し、ろ過水取水管14を通じて排出され、処理水槽15に流入し、処理水21として取り出される。なお、ろ過後の汚泥混合液は、汚泥循環液19として生物反応槽2に返送される。
The present invention will be described more specifically with reference to the drawings.
FIG. 1 is a flow sheet showing an example of a treatment method according to the present invention for a group groundwater.
As shown in FIG. 1, inflow raw water 1 flows into a biological reaction tank 2, and aerobic treatment with activated sludge is performed by supplying air from the aeration blower 4 to the aeration pipe 3 in the biological reaction tank 2. The activated sludge mixed liquid is supplied to the filtration separation tank 10 from the sludge supply pump 5. The activated sludge mixed liquid that has flowed into the filtration separation tank 10 is filtered from the water-permeable filter 11 at a head pressure ΔH, opens the filtered water intake valve 17, is discharged through the filtered water intake pipe 14, and flows into the treated water tank 15. The treated water 21 is taken out. In addition, the sludge mixed liquid after filtration is returned to the biological reaction tank 2 as the sludge circulating liquid 19.

ろ過体11の洗浄法として、ろ過体浸漬中では通常、空洗によるろ過Fluxの安定化を行う。この時、空洗ブロワ9から数時間毎に1回の割合でろ過体下方の空洗散気管8に送気して行われる。
ろ過水を用いた水逆洗は、数週間に1回の頻度で定期的に行う。水逆洗時は、ろ過槽10内の混合液汚泥を、汚泥混合液供給バルブ6と汚泥混合液移送バルブ7の切り替えで、汚泥混合液ポンプ5より一旦生物反応槽2へ返送した後、逆洗ポンプ12を起動させ、処理水槽15の処理水(ろ過水)21をろ過体11上方の逆洗ライン13を通じてろ過体11の内部に供給される。
逆洗排水は、ろ過体11の下部の取水管より排出し、逆洗排水返送弁16を開き、逆洗排水返送ライン18を通じて生物反応槽2に返送される。この場合は、ろ過水取水弁17は閉となる。なお、この水逆洗時、ろ過体11の内部からその表面に出てろ過分離槽10に排出される逆洗排水は、常時汚泥混合液用ポンプ5より生物反応槽2に返送されようにする。
逆洗操作終了後は再び生物反応槽2の汚泥混合液をろ過分離槽10に供給すれば、通水性ろ過体11からのろ過水をろ過水取水弁17を経て連続して得られる。
As a washing method for the filter body 11, during the filtration body immersion, the filtration flux is usually stabilized by air washing. At this time, it is carried out by sending air from the air washing blower 9 to the air washing air diffuser 8 below the filter body once every several hours.
Water backwashing using filtered water is performed periodically at a frequency of once every several weeks. At the time of water backwashing, the mixed liquid sludge in the filtration tank 10 is temporarily returned to the biological reaction tank 2 from the sludge mixed liquid pump 5 by switching between the sludge mixed liquid supply valve 6 and the sludge mixed liquid transfer valve 7, and then reversely mixed. The washing pump 12 is activated, and the treated water (filtered water) 21 in the treated water tank 15 is supplied into the filter body 11 through the backwash line 13 above the filter body 11.
The backwash drainage is discharged from the intake pipe below the filter body 11, the backwash drainage return valve 16 is opened, and returned to the biological reaction tank 2 through the backwash drainage return line 18. In this case, the filtered water intake valve 17 is closed. In addition, at the time of this water backwashing, the backwash waste water which comes out to the surface from the inside of the filter body 11 and is discharged | emitted by the filtration separation tank 10 is always returned to the biological reaction tank 2 from the sludge liquid mixture pump 5. .
If the sludge mixed liquid of the biological reaction tank 2 is again supplied to the filtration separation tank 10 after the backwashing operation is completed, the filtrate from the water-permeable filter 11 can be continuously obtained through the filtered water intake valve 17.

なお、図2において、10はろ過分離槽、13は逆洗水ライン、22は逆洗排水ラインであり、円筒形のろ過体(織布)11は、ろ過体支持部23のスペーサ24上にゆるやかに嵌着されている。逆洗水は逆洗水ライン13から逆洗排水ライン22へ流出するとともに、スペーサ24を通してろ過体(織布)11の内部に堆積した汚泥及び表面に付着した汚泥粒子を洗い落としながら流れ、ろ過体の内部の汚泥は洗浄排水とともに逆洗排水ライン22から外部に出て、ろ過体11の表面に付着した汚泥粒子でろ過体11内部からの逆洗水で外に流れ出したものはろ過分離槽10の底部へ流下する。   In FIG. 2, 10 is a filtration separation tank, 13 is a backwash water line, 22 is a backwash drainage line, and the cylindrical filter body (woven fabric) 11 is placed on the spacer 24 of the filter support part 23. It is loosely fitted. The backwash water flows from the backwash water line 13 to the backwash drainage line 22 and flows through the spacer 24 while washing away the sludge accumulated inside the filter body (woven cloth) 11 and the sludge particles adhering to the surface, and the filter body. The sludge inside the slag flows out from the backwash drainage line 22 together with the wash sewage, and the sludge particles adhering to the surface of the filter body 11 flow out to the outside with the backwash water from the inside of the filter body 11. Flow down to the bottom.

以下実施例により本発明を具体的に説明する。ただし本発明はこの実施例のみに限定されるものではない。   The present invention will be specifically described below with reference to examples. However, the present invention is not limited to this example.

実施例1
(処理方法)
団地下水について、図1に示すフローシートで表わされる本発明による処理法により処理を行った。
この団地下水の水質は、第1表に示すとおりである。
団地下水を活性汚泥を用いて処理する生物反応槽は、活性汚泥のMLSSが約3500mg/リットルであった。前記生物反応槽から出る活性汚泥混合液を下記に示すろ過分離槽に導き、処理水を得た。
前記ろ過分離槽で得られる処理水の水質は、第1表に示すとおりである。
Example 1
(Processing method)
About the collective groundwater, it processed by the processing method by this invention represented with the flow sheet shown in FIG.
The quality of the groundwater is as shown in Table 1.
In the biological reaction tank that treats the groundwater with activated sludge, the MLSS of activated sludge was about 3500 mg / liter. The activated sludge mixed solution exiting from the biological reaction tank was guided to the filtration / separation tank shown below to obtain treated water.
The quality of the treated water obtained in the filtration separation tank is as shown in Table 1.

(ろ過分離槽)
ろ過分離槽としては、有効面積0.3m2 、有効容積0.6m3 の固液分離槽を用いた。ろ過分離槽10内部に有効面積1m2 /枚の平面形織布ろ過体5枚をろ過体モジュールとして浸漬設置した。織布の素材としては、ポリエステル製で、目開き200メッシュ、厚み0.09mmのものを用いた。なお、ろ過時の平均水頭圧を約10cmとした。
このろ過分離槽の処理条件を表で示すと、第2表のとおりである。
また、第3表にろ過体の空洗及びろ過水による逆洗の条件を示す。
(Filtration separation tank)
As the filtration separation tank, a solid-liquid separation tank having an effective area of 0.3 m 2 and an effective volume of 0.6 m 3 was used. Five flat woven fabric filter bodies having an effective area of 1 m 2 / sheet were immersed in the filter separation tank 10 as a filter module. The material of the woven fabric was made of polyester, having an opening of 200 mesh and a thickness of 0.09 mm. The average head pressure during filtration was about 10 cm.
Table 2 shows the processing conditions of the filtration / separation tank.
Table 3 shows the conditions for washing the filter body with air and backwashing with filtered water.

Figure 2006055852
Figure 2006055852

Figure 2006055852
Figure 2006055852

Figure 2006055852
Figure 2006055852

(処理結果)
図3にこの実施例におけるろ過Fluxの経過を示す。
処理対象とする活性汚泥のMLSSが約3500mg/リットルであり、2ヶ月の処理期間中、ろ過Fluxが4.2〜4.8m/dに維持でき、2週間に1回のろ過水による逆洗を加えたことにより、安定したろ過Fluxが得られた。なお、ろ過水の濁度が処理期間中で平均5度前後であり、清澄であった。
(Processing result)
FIG. 3 shows the course of the filtration flux in this example.
The MLSS of the activated sludge to be treated is about 3500 mg / liter, and the filtration flux can be maintained at 4.2 to 4.8 m / d during the treatment period of 2 months, and backwashing with filtered water once every 2 weeks. Was added to obtain a stable filtered flux. In addition, the turbidity of filtered water was around 5 degrees on average during the treatment period, and it was clear.

比較例1
実施例1と同様な操作条件で、ろ過体モジュール内部に対する定期的な水逆洗を行わないで、活性汚泥混合液のろ過処理を行った。その場合の平均ろ過Fluxの経過を図4に示す。
平均ろ過Fluxは、処理開始時に実施例1とほぼ同様の約4.8m/dであった。しかし、処理開始から約10日後に、ろ過Fluxが急激に低下した。これは、ろ過体表面への汚泥微粒子付着及びろ過体内部の汚泥堆積に起因するものである。
その結果、通常の空洗を4時間に1回の頻度で実施しても、ろ過Fluxの回復が得られず、処理開始から20日後に、ろ過Fluxが初期値の半分以下の1.8m/dに低下した。その後も徐々に低下し、1m/d以下となった。なお、ろ過水濁度は常時10度以下で実施例と大きな差異は認められなかった。
Comparative Example 1
Under the same operating conditions as in Example 1, the filtration treatment of the activated sludge mixture was performed without performing regular water backwashing on the inside of the filter module. The course of the average filtration flux in that case is shown in FIG.
The average filtration flux was about 4.8 m / d, which was almost the same as in Example 1 at the start of the treatment. However, after about 10 days from the start of the treatment, the filtration flux dropped rapidly. This is due to sludge fine particles adhering to the surface of the filter body and sludge accumulation inside the filter body.
As a result, even if normal empty washing was carried out once every 4 hours, recovery of the filtration flux was not obtained, and after 20 days from the start of the treatment, the filtration flux was 1.8 m / m or less of half of the initial value. d. After that, it gradually decreased to 1 m / d or less. In addition, filtration water turbidity was always 10 degrees or less, and the big difference with an Example was not recognized.

本発明の通水性ろ過体の洗浄装置を含む生物処理汚水の固液分離装置の説明図である。It is explanatory drawing of the solid-liquid separation apparatus of the biological treatment wastewater containing the washing | cleaning apparatus of the water-permeable filter of this invention. 本発明のろ過体の洗浄装置の逆洗処理状況の説明図である。It is explanatory drawing of the backwash process condition of the washing | cleaning apparatus of the filter body of this invention. 本発明の一実施例の経過日数と平均ろ過Fluxの関係を示すグラフである。It is a graph which shows the relationship between the elapsed days of one Example of this invention, and average filtration Flux. 比較例1の経過日数と平均ろ過Fluxの関係を示すグラフである。It is a graph which shows the relationship between the elapsed days of the comparative example 1, and the average filtration Flux.

符号の説明Explanation of symbols

1 流入原水
2 生物反応槽
3 散気管
4 曝気ブロワ
5 汚泥混合液用ポンプ
6 汚泥混合液供給バルブ
7 汚泥混合液返送バルブ
8 空洗散気管
9 空洗ブロワ
10 ろ過分離槽
11 通水性ろ過体
12 逆洗ポンプ
13 逆洗ライン
14 ろ過水取水管
15 処理水槽
16 逆洗排水返送弁
17 ろ過水取水弁
18 逆洗排水返送ライン
19 汚泥循環液
20 排泥ライン
21 処理水
22 逆洗排水ライン
23 ろ過体支持部
24 スペーサ
25 織布
DESCRIPTION OF SYMBOLS 1 Inflow raw water 2 Biological reaction tank 3 Aeration pipe 4 Aeration blower 5 Sludge liquid mixture pump 6 Sludge liquid mixture supply valve 7 Sludge liquid mixture return valve 8 Air washing air diffuser 9 Air washing blower 10 Filtration separation tank 11 Water-permeable filter body 12 Backwash pump 13 Backwash line 14 Filtration water intake pipe 15 Treated water tank 16 Backwash drainage return valve 17 Filtration water intake valve 18 Backwash drainage return line 19 Sludge circulating liquid 20 Waste mud line 21 Treated water 22 Backwash drainage line 23 Filtration Body support part 24 Spacer 25 Woven cloth

Claims (4)

原水を流入させて好気的に活性汚泥による処理を行う生物反応槽からの活性汚泥混合液を、通水性ろ過体を設置したろ過分離槽に供給し、該ろ過分離槽で該ろ過体表面に汚泥のダイナミックろ過層を形成させてろ過を行ってろ過水を得、ろ過後の活性汚泥混合液を生物反応槽に返送する活性汚泥混合液の固液分離法において、該ろ過体洗浄時、ろ過分離槽内の活性汚泥混合液を生物反応槽に完全に返送した後、あるいはろ過分離槽にろ過水を満たした時点で該ろ過体の内部に対し水逆洗し、逆洗排水を生物反応槽に返送することを特徴とするろ過体の洗浄方法。   The activated sludge mixed liquid from the biological reaction tank that performs the treatment with activated sludge aerobically by inflowing raw water is supplied to the filtration separation tank in which the water-permeable filter is installed, and the filtration separation tank is used for the surface of the filter body. In the solid-liquid separation method of the activated sludge mixed liquid in which the sludge dynamic filtration layer is formed and filtered to obtain filtered water, and the activated sludge mixed liquid after filtration is returned to the biological reaction tank, the filter is washed when the filter is washed. After the activated sludge mixed liquid in the separation tank is completely returned to the biological reaction tank, or when the filtered separation tank is filled with filtered water, the inside of the filter body is back-washed with water, and the backwash waste water is removed from the biological reaction tank. A method of cleaning a filter body, characterized by being returned to the factory. ろ過体内部への水逆洗は、ろ過体上部の逆洗ラインにろ過水あるいは薬品洗浄液を流入させ、ろ過体下部の取水ラインより逆洗排水を排出することを特徴とする請求項1記載のろ過体の洗浄方法。   The backwashing of water into the filter body is characterized in that filtered water or chemical washing liquid is allowed to flow into a backwash line at the top of the filter body, and backwash drainage is discharged from the water intake line at the bottom of the filter body. How to wash the filter. 原水を流入させて好気的に活性汚泥による処理を行う生物反応槽からの活性汚泥混合液を供給され、通水性ろ過体を有し、該ろ過体によるろ過に際して該ろ過体表面に汚泥のダイナミックろ過層を形成してろ過水を得るろ過分離槽を用いる活性汚泥混合液の固液分離装置において、該ろ過分離槽内に浸漬されたダイナミックろ過層を形成した通水性ろ過体の下方に配置された空洗用の空洗散気管と、ろ過分離槽内の活性汚泥混合液の生物反応槽への返送用の配管、あるいはろ過分離槽にろ過水を満たすための処理水槽からの配管と、ろ過分離槽内の活性汚泥混合液を生物反応槽に完全に返送した後、あるいはろ過分離槽にろ過水を満たした時点で作動する、処理水槽からの該ろ過体の内部に処理水を送るよう接続された逆洗水ラインと、該ろ過体の内部からの逆洗排水を排出するための逆洗排水ラインとからなる逆洗ユニットを有することを特徴とするろ過体の洗浄装置。   Activated sludge mixed liquid is supplied from a biological reaction tank in which raw water is introduced and aerobically treated with activated sludge, and has a water-permeable filter, and sludge dynamics are applied to the surface of the filter during filtration by the filter. In a solid-liquid separation device for an activated sludge mixed liquid using a filtration separation tank that forms a filtration layer to obtain filtered water, it is disposed below a water-permeable filter body that forms a dynamic filtration layer immersed in the filtration separation tank. Air washing air diffuser for air washing, piping for returning the activated sludge mixed liquid in the filtration separation tank to the biological reaction tank, piping from the treated water tank for filling the filtration separation tank with filtered water, and filtration Connected to send treated water from the treated water tank to the inside of the filter body that operates after the activated sludge mixed liquid in the separation tank is completely returned to the biological reaction tank or when the filtered separation tank is filled with filtered water Backwash water line and Body cleaning device of the filtering body and having a backwash unit comprising a backwash drain line for discharging the backwash effluent from the interior of. 逆洗ユニットは、ろ過体支持部の上部の逆洗水ラインからろ過水あるいは薬品洗浄液を流入させ、下部の逆洗排水ラインより逆洗排水あるいは排液を排出するとともに、ろ過体と接触するように設けた通水性スペーサからろ過体内部に対し逆洗を行うように構成されていることを特徴とする請求項3記載のろ過体の洗浄装置。   The backwash unit allows filtered water or chemical cleaning liquid to flow from the backwash water line at the top of the filter support part, discharges backwash wastewater or drainage from the backwash drainage line at the bottom, and makes contact with the filter body. 4. The filter cleaning apparatus according to claim 3, wherein the filter body is back-washed from the water-permeable spacer provided in the filter.
JP2005285179A 2005-09-29 2005-09-29 Method and apparatus for treating organic wastewater Expired - Fee Related JP4335193B2 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009538733A (en) * 2006-05-31 2009-11-12 エックス−フロー ベー.フェー. Apparatus for treatment of incoming fluid with bioreactor and membrane filtration module
JP2012108449A (en) * 2010-11-16 2012-06-07 E-Pin Optical Industry Co Ltd Optical imaging lens with two lenses

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009538733A (en) * 2006-05-31 2009-11-12 エックス−フロー ベー.フェー. Apparatus for treatment of incoming fluid with bioreactor and membrane filtration module
US10266439B2 (en) 2006-05-31 2019-04-23 X-Flow B.V. Method for cleaning membranes and an inlet side of a membrane filtration module of an apparatus having a bioreactor and membrane filtration module for treatment of an incoming fluid
JP2012108449A (en) * 2010-11-16 2012-06-07 E-Pin Optical Industry Co Ltd Optical imaging lens with two lenses

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