JP7230386B2 - Water treatment device and water treatment method - Google Patents

Water treatment device and water treatment method Download PDF

Info

Publication number
JP7230386B2
JP7230386B2 JP2018172879A JP2018172879A JP7230386B2 JP 7230386 B2 JP7230386 B2 JP 7230386B2 JP 2018172879 A JP2018172879 A JP 2018172879A JP 2018172879 A JP2018172879 A JP 2018172879A JP 7230386 B2 JP7230386 B2 JP 7230386B2
Authority
JP
Japan
Prior art keywords
tank
water
aeration
water treatment
treated
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.)
Active
Application number
JP2018172879A
Other languages
Japanese (ja)
Other versions
JP2020044471A (en
Inventor
隆太 梅田
恵介 渡辺
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.)
New Oji Paper Co Ltd
Oji Holdings Corp
Original Assignee
Oji Holdings Corp
Oji Paper 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 Oji Holdings Corp, Oji Paper Co Ltd filed Critical Oji Holdings Corp
Priority to JP2018172879A priority Critical patent/JP7230386B2/en
Publication of JP2020044471A publication Critical patent/JP2020044471A/en
Application granted granted Critical
Publication of JP7230386B2 publication Critical patent/JP7230386B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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

  • Biological Treatment Of Waste Water (AREA)
  • Activated Sludge Processes (AREA)

Description

本発明は、水処理装置および水処理方法に関する。 The present invention relates to a water treatment device and a water treatment method.

一般的な水質指標のひとつに、生物化学的酸素要求量(Biochemical Oxygen Demand;BOD)と呼ばれる値がある。例えば、食品加工系排水などの有機物を含む排水は、BODの値が高くなる。
BODが高い被処理水の水処理方法として、微生物により有機物を分解除去する処理槽を用いる方法が知られており、例えば活性汚泥法や生物膜法などがよく知られている。活性汚泥法は、曝気装置を備える処理槽である曝気槽を用いて、活性汚泥中の好気性微生物に被処理水中の有機物などの汚濁物質を分解させる方法である。生物膜法は、担体の表面または内部に付着させた微生物に被処理水中の有機物などの汚濁物質を分解させる方法である。
One of the common water quality indices is a value called biochemical oxygen demand (BOD). For example, waste water containing organic matter such as food processing waste water has a high BOD value.
As a method for treating water having a high BOD, a method using a treatment tank in which organic matter is decomposed and removed by microorganisms is known. For example, the activated sludge method and the biofilm method are well known. The activated sludge method is a method in which aerobic microorganisms in activated sludge decompose contaminants such as organic matter in water to be treated using an aeration tank, which is a treatment tank equipped with an aerator. The biofilm method is a method of decomposing contaminants such as organic substances in water to be treated by microorganisms adhered to the surface or inside of a carrier.

特許文献1には、好気性条件下で有機性排水を微生物により処理する有機性排水の処理方法であって、有機性排水を1kgBOD/m/day以上の高負荷にて好気性生物処理を行う第1の生物処理工程と、第1の生物処理工程で処理した処理水を、凝集剤を使用した凝集処理にて凝集分離を行う工程と、凝集分離された処理水を第1の生物処理よりも低い負荷で好気性生物処理を行う第2の生物処理工程と、を含む、有機性排水の処理方法が記載されている。特許文献1では、第1の生物処理および第2の生物処理のいずれでも担体を用いており、第1の生物処理は固定床もしくは流動床担体を、第2の生物処理は繊維及び活性炭のいずれかもしくは両方を含む生物担体を用いることが好ましいと記載されている。 Patent Document 1 discloses a method for treating organic wastewater by treating organic wastewater with microorganisms under aerobic conditions, wherein the organic wastewater is subjected to aerobic biological treatment at a high load of 1 kgBOD/m 3 /day or more. a first biological treatment step to perform, a step of flocculating and separating the treated water treated in the first biological treatment step by flocculation treatment using a flocculant, and flocculating and separating the flocculated treated water to the first biological treatment and a second biological treatment step that performs aerobic biological treatment at a lower load. In Patent Document 1, both the first biological treatment and the second biological treatment use a carrier, the first biological treatment uses a fixed bed or fluidized bed carrier, and the second biological treatment uses either fiber or activated carbon. It is stated that it is preferable to use a biological carrier containing either or both.

特許文献2には、有機性排水を生物処理槽に導入して活性汚泥処理し、生物処理槽の処理液を汚泥と処理水とに固液分離する生物処理方法において、生物処理槽内の汚泥の一部及び/又は分離汚泥の少なくとも一部を、槽内に孔径5~100μmの浸漬濾材を設けた汚泥処理槽に導入して好気性生物処理し、浸漬濾材の透過液を生物処理槽に返送する、有機性排水の生物処理方法が記載されている。
また、特許文献2には、有機性排水を第1生物処理槽に導入して細菌により生物処理し、第1生物処理槽からの細菌を含む処理液を第2生物処理槽に導入して活性汚泥処理し、第2生物処理槽の処理液を汚泥と処理水とに固液分離する生物処理方法において、第2生物処理槽内の汚泥の一部及び/又は分離汚泥の少なくとも一部を、槽内に孔径5~100μmの浸漬濾材を設けた汚泥処理槽に導入して好気性生物処理し、浸漬濾材の透過液を第1生物処理槽及び/又は第2生物処理槽に返送する、有機性排水の生物処理方法も記載されている。
Patent Document 2 describes a biological treatment method in which organic wastewater is introduced into a biological treatment tank and treated with activated sludge, and the treated liquid in the biological treatment tank is separated into solid-liquid sludge and treated water. Part of and / or at least part of the separated sludge is introduced into a sludge treatment tank provided with an immersion filter medium with a pore size of 5 to 100 μm in the tank for aerobic biological treatment, and the permeate of the immersion filter medium is introduced into the biological treatment tank. A method for the biological treatment of returning, organic waste water is described.
Further, in Patent Document 2, organic wastewater is introduced into a first biological treatment tank and biologically treated with bacteria, and the treated liquid containing bacteria from the first biological treatment tank is introduced into a second biological treatment tank and activated. In a biological treatment method in which sludge is treated and the treated liquid in the second biological treatment tank is solid-liquid separated into sludge and treated water, part of the sludge in the second biological treatment tank and/or at least part of the separated sludge is The organic A method for biological treatment of toxic wastewater is also described.

特開2006-828号公報JP-A-2006-828 特開2006-247494号公報JP 2006-247494 A

BODが高い被処理水を効率的に水処理しようとする場合、曝気槽の容積に対する1日間に処理できるBOD量(BOD容積負荷)を高くする必要があるが、通常の活性汚泥法では高BOD容積負荷処理できないと考えられていた(例えば、特許文献1の[0028]参照)。
また、本発明者らが、流動床担体などの生物膜法にて曝気槽を用いて高BOD容積負荷処理を行ったところ、過剰に汚泥量が増えてしまう問題が生じることがわかった。
When trying to efficiently treat water with high BOD, it is necessary to increase the amount of BOD that can be treated per day (BOD volume load) relative to the volume of the aeration tank. It was thought that volume load processing could not be performed (for example, see [0028] of Patent Document 1).
In addition, when the present inventors performed high BOD volume load treatment using an aeration tank in a biofilm method such as a fluidized bed carrier, it was found that the problem of an excessive increase in the amount of sludge occurred.

一方、特許文献1に記載の生物膜法を用いる方法は、第1の生物処理および第2の生物処理のいずれでも担体を用いる点で運用コストが高く、また、第1の生物処理および第2の生物処理の間に凝集剤を使用して凝集分離する点で薬品コストおよび設備コストが高いことがわかった。
特許文献2に記載の方法は、汚泥処理槽において担体として浸透膜などの浸漬濾材として用いる点で運用コストやメンテナンスコストが高く、浸漬濾材の透過液(返送汚泥)をその量を制御しながら生物処理槽に返送する手段が必要な点で設備コストおよびメンテナンスコストが高いことがわかった。
On the other hand, the method using the biofilm method described in Patent Document 1 has a high operating cost in that a carrier is used in both the first biological treatment and the second biological treatment, and the first biological treatment and the second biological treatment Chemical and equipment costs were found to be high in terms of flocculation using flocculants during biological treatment of biomass.
The method described in Patent Document 2 is high in operation and maintenance costs in that it is used as a submerged filter medium such as a permeable membrane as a carrier in the sludge treatment tank, and the permeate of the submerged filter medium (returned sludge) is controlled to the amount of organisms. Equipment and maintenance costs were found to be high due to the need for a means of returning the waste to the treatment tank.

本発明が解決しようとする課題は、BODが高い被処理水を用いて高BOD容積負荷処理を行う場合に汚泥量を顕著に減らすことができ、かつ、低コストである水処理装置を提供することにある。 The problem to be solved by the present invention is to provide a low-cost water treatment apparatus that can significantly reduce the amount of sludge when performing high BOD volume load treatment using water to be treated with high BOD. That's what it is.

上記の課題を解決するために鋭意検討を行った結果、本発明者らは、流動床担体による生物処理を行う曝気槽と、汚泥減量をするための担体を含まない消化槽をこの順で連結することにより、上記の課題を解決できることを見出した。
具体的に、本発明および本発明の好ましい構成は、以下のとおりである。
As a result of intensive studies to solve the above problems, the present inventors connected an aeration tank for biological treatment with a fluidized bed carrier and a digestion tank containing no carrier for sludge reduction in this order. The inventors have found that the above problems can be solved by
Specifically, the present invention and preferred configurations of the present invention are as follows.

[1] 曝気槽および消化槽をこの順で備える水処理装置であって;
被処理水の曝気槽に対するBOD容積負荷が0.8~4.0kg/m/dayであり;
曝気槽が曝気手段および流動床担体を備え;
消化槽が曝気手段を備え、かつ、担体を含まない;水処理装置。
[2] 曝気槽でのBOD除去率が70%以上である[1]に記載の水処理装置。
[3] 流動床担体の充填率が40~50%である[1]または[2]に記載の水処理装置。
[4] 流動床担体がポリプロピレン製である[1]~[3]のいずれか一つに記載の水処理装置。
[5] 流動床担体が略円柱状である[1]~[4]のいずれか一つに記載の水処理装置。
[6] 曝気槽が、流動床担体の消化槽への移動を制限できるスクリーンを備える[1]~[5]のいずれか一つに記載の水処理装置。
[7] 被処理水の曝気槽に対するBOD容積負荷が1.5~2.5kg/m/dayである[1]~[6]のいずれか一つに記載の水処理装置。
[8] 被処理水が食品加工系排水である[1]~[7]のいずれか一つに記載の水処理装置。
[9] 被処理水の温度が1~15℃である[1]~[8]のいずれか一つに記載の水処理装置。
[10] 消化槽の下流に沈殿槽を有する[1]~[9]のいずれか一つに記載の水処理装置。
[11] 沈殿槽から、曝気槽および消化槽の少なくとも一方に汚泥を返送する手段を備えない[10]に記載の水処理装置。
[12] 曝気槽および消化槽をこの順で備える水処理装置に被処理水を通過させる水処理方法であって;
被処理水の曝気槽に対するBOD容積負荷が0.8~4.0kg/m/dayであり;
曝気槽が曝気手段および流動床担体を備え;
消化槽が曝気手段を備え、かつ、担体を含まない;水処理方法。
[1] A water treatment apparatus comprising an aeration tank and a digestion tank in this order;
BOD volumetric load on the aeration tank of the water to be treated is 0.8 to 4.0 kg/m 3 /day;
an aeration tank comprising an aeration means and a fluidized bed carrier;
A digester equipped with aeration means and containing no carrier; water treatment equipment.
[2] The water treatment device according to [1], wherein the BOD removal rate in the aeration tank is 70% or more.
[3] The water treatment apparatus according to [1] or [2], wherein the fluidized bed carrier has a packing rate of 40 to 50%.
[4] The water treatment apparatus according to any one of [1] to [3], wherein the fluidized bed carrier is made of polypropylene.
[5] The water treatment apparatus according to any one of [1] to [4], wherein the fluidized bed carrier is substantially cylindrical.
[6] The water treatment apparatus according to any one of [1] to [5], wherein the aeration tank is equipped with a screen capable of restricting movement of the fluidized bed carrier to the digestion tank.
[7] The water treatment apparatus according to any one of [1] to [6], wherein the BOD volume load of the water to be treated to the aeration tank is 1.5 to 2.5 kg/m 3 /day.
[8] The water treatment apparatus according to any one of [1] to [7], wherein the water to be treated is food processing wastewater.
[9] The water treatment apparatus according to any one of [1] to [8], wherein the temperature of the water to be treated is 1 to 15°C.
[10] The water treatment apparatus according to any one of [1] to [9], which has a sedimentation tank downstream of the digestion tank.
[11] The water treatment apparatus according to [10], which does not include means for returning sludge from the sedimentation tank to at least one of the aeration tank and the digestion tank.
[12] A water treatment method of passing water to be treated through a water treatment apparatus comprising an aeration tank and a digestion tank in this order;
BOD volumetric load on the aeration tank of the water to be treated is 0.8 to 4.0 kg/m 3 /day;
an aeration tank comprising an aeration means and a fluidized bed carrier;
A digester equipped with aeration means and containing no carrier; a water treatment method.

本発明によれば、BODが高い被処理水を用いて高BOD容積負荷処理を行う場合に汚泥量を顕著に減らすことができ、かつ、低コストである水処理装置を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, when performing a high BOD volume load process using the to-be-processed water with high BOD, the amount of sludge can be reduced remarkably, and a low-cost water treatment apparatus can be provided.

図1は、本発明の水処理装置の一例の断面概略図である。FIG. 1 is a schematic cross-sectional view of an example of the water treatment apparatus of the present invention. 図2は、本発明の水処理装置の他の一例の断面概略図である。FIG. 2 is a schematic cross-sectional view of another example of the water treatment apparatus of the present invention. 図3は、本発明の水処理装置の他の一例の断面概略図である。FIG. 3 is a schematic cross-sectional view of another example of the water treatment apparatus of the present invention. 図4は、本発明の水処理装置の他の一例の断面概略図である。FIG. 4 is a schematic cross-sectional view of another example of the water treatment apparatus of the present invention.

以下において、本発明について詳細に説明する。以下に記載する構成要件の説明は、代表的な実施形態や具体例に基づいてなされることがあるが、本発明はそのような実施形態に限定されるものではない。なお、本明細書において「~」を用いて表される数値範囲は「~」前後に記載される数値を下限値および上限値として含む範囲を意味する。 The present invention will be described in detail below. Although the constituent elements described below may be described based on representative embodiments and specific examples, the present invention is not limited to such embodiments. In the present specification, a numerical range represented by "-" means a range including the numerical values described before and after "-" as lower and upper limits.

[水処理装置]
本発明の水処理装置は、曝気槽および消化槽をこの順で備える水処理装置であって;被処理水の曝気槽に対するBOD容積負荷が0.8~4.0kg/m/dayであり;曝気槽が曝気手段および流動床担体を備え;消化槽が曝気手段を備え、かつ、担体を含まない。
この構成により、本発明の水処理装置は、BODが高い被処理水を用いて高BOD容積負荷処理を行う場合に汚泥量を顕著に減らすことができ、かつ、低コストである。曝気手段を備え、かつ、担体を含まない消化槽の作用により、低コストで、高BOD容積負荷処理を行う際に多量に出る汚泥の減量が可能となる。また、曝気槽では担体として流動床担体を用いることにより、流動床担体内に生物相を保持させることができ、高BOD容積負荷処理を小さな体積で(曝気槽の設置スペースを縮小して)行うことができ、設備コストを低くできる。
以下、本発明の水処理装置の好ましい態様を説明する。
[Water treatment equipment]
The water treatment apparatus of the present invention comprises an aeration tank and a digestion tank in this order; the BOD volume load of the water to be treated on the aeration tank is 0.8 to 4.0 kg/m 3 /day. an aeration tank with aeration means and a fluid bed carrier; a digestion tank with aeration means and no carrier.
With this configuration, the water treatment apparatus of the present invention can significantly reduce the amount of sludge when performing high BOD volume load treatment using water to be treated with high BOD, and is low cost. The action of a digestion tank equipped with an aeration means and containing no carrier makes it possible to reduce the amount of sludge, which is generated in large amounts when performing high BOD volume load treatment, at low cost. In addition, by using a fluidized bed carrier as a carrier in the aeration tank, the biophase can be retained in the fluidized bed carrier, and high BOD volume load treatment can be performed in a small volume (reducing the installation space of the aeration tank). can reduce equipment costs.
Preferred embodiments of the water treatment apparatus of the present invention are described below.

<全体構成>
まず、本発明の水処理装置の全体構成について説明する。
図1は、本発明の水処理装置の一例の断面概略図である。図1に示した水処理装置は、曝気槽11および消化槽12をこの順で備える水処理装置であって、曝気槽11が曝気手段22および流動床担体21を備え;消化槽が曝気手段22を備え、かつ、担体を含まない。
<Overall composition>
First, the overall configuration of the water treatment apparatus of the present invention will be described.
FIG. 1 is a schematic cross-sectional view of an example of the water treatment apparatus of the present invention. The water treatment apparatus shown in FIG. 1 is a water treatment apparatus comprising an aeration tank 11 and a digestion tank 12 in this order, the aeration tank 11 having an aeration means 22 and a fluidized bed carrier 21; and does not contain a carrier.

図1に示した水処理装置を用いる水処理方法を説明する。図1では、水の流れを実線の矢印で示している。図1に示した水処理装置では、被処理水1は曝気槽11に送液される。
曝気槽11において、被処理水1は、曝気手段22からの気体に曝気されながら流動床担体21によって生物処理された後、生物処理水2として曝気槽11から消化槽12に送液される。
消化槽12において、生物処理水2は曝気手段22からの気体に曝気された後、処理水3として消化槽12から下流に排出される。消化槽12からの処理水3は、そのまま海洋や河川等の外部領域に放出されてもよく、用水として回収および再利用されてもよく、あるいは、さらに排水処理が施されてもよい。
A water treatment method using the water treatment apparatus shown in FIG. 1 will be described. In FIG. 1, the flow of water is indicated by solid arrows. In the water treatment apparatus shown in FIG. 1, the water 1 to be treated is sent to the aeration tank 11 .
In the aeration tank 11 , the water to be treated 1 is biologically treated by the fluidized bed carrier 21 while being aerated with the gas from the aeration means 22 , and then sent as the biologically treated water 2 from the aeration tank 11 to the digestion tank 12 .
In the digestion tank 12 , the biologically treated water 2 is aerated with gas from the aeration means 22 and then discharged downstream from the digestion tank 12 as treated water 3 . The treated water 3 from the digestion tank 12 may be discharged to an external area such as the ocean or a river as it is, may be recovered and reused as industrial water, or may be further subjected to wastewater treatment.

図2は、本発明の水処理装置の他の一例の断面概略図である。図2に示した水処理装置は、図1に示した構成の水処理装置において、さらに曝気槽11が、流動床担体21の消化槽12への移動を制限できるスクリーン23を備える構成である。 FIG. 2 is a schematic cross-sectional view of another example of the water treatment apparatus of the present invention. The water treatment apparatus shown in FIG. 2 is a water treatment apparatus having the structure shown in FIG.

図3は、本発明の水処理装置の他の一例の断面概略図である。図3に示した水処理装置は、図2に示した構成の水処理装置において、さらに消化槽12の下流に沈殿槽13を有する構成である。 FIG. 3 is a schematic cross-sectional view of another example of the water treatment apparatus of the present invention. The water treatment apparatus shown in FIG. 3 has a sedimentation tank 13 downstream of the digestion tank 12 in addition to the water treatment apparatus shown in FIG.

図4は、本発明の水処理装置の他の一例の断面概略図である。図4に示した水処理装置は、図3に示した構成の水処理装置において、さらに曝気槽11の上流に調整槽14を有する構成である。 FIG. 4 is a schematic cross-sectional view of another example of the water treatment apparatus of the present invention. The water treatment apparatus shown in FIG. 4 is the same as the water treatment apparatus shown in FIG.

<被処理水>
本発明の水処理装置は高BOD容積負荷処理を行うことができるため、BODが高い被処理水を用いることができる。このような被処理水としては、例えば、食品加工総合排水や水産加工工場の排水などの食品加工系排水、植物工場の養液や陸上養殖の飼育水といった生物汚濁水、下水、一般汚水の浄化処理に用いることができる。中でも、本発明の水処理装置は、被処理水が食品加工系排水である場合に、特に好ましく用いられる。
<Water to be treated>
Since the water treatment apparatus of the present invention can perform high BOD volume load treatment, water to be treated with high BOD can be used. Such water to be treated includes, for example, food processing wastewater such as general wastewater from food processing and wastewater from fishery processing factories, biocontaminated water such as nutrient solution from plant factories and breeding water for land-based aquaculture, sewage, and general sewage purification. can be used for processing. Above all, the water treatment apparatus of the present invention is particularly preferably used when the water to be treated is food processing wastewater.

(BOD容積負荷)
本発明では、被処理水の曝気槽に対するBOD容積負荷が0.8~4.0kg/m/dayである。なお、BOD容積負荷の単位として「kg-BOD/m/day」を用いられることもあるが、本明細書における「kg/m/day」と同義である。
本発明の水処理装置は、被処理水の曝気槽に対するBOD容積負荷を高くして水処理ができる。BOD容積負荷の下限値は1.0kg/m/day以上であることが好ましく、1.2kg/m/day以上であることがより好ましく、1.5kg/m/day以上であることが特に好ましく、2.0kg/m/day以上であることがより特に好ましい。ただし、処理水のS-BODの高さ、生物処理水のS-BOD除去率の低さを許容しつつ、高BOD容積負荷処理を重視する場合は、BOD容積負荷を2.5kg/m/day以上とすることも好ましく、3.0kg/m/day以上とすることも好ましい。
被処理水の曝気槽に対するBOD容積負荷をある程度低くすることで、さらに処理水のS-BODを低くでき、かつ、曝気槽S-BOD処理率を高くすることができる。この観点から、BOD容積負荷の上限値は3.5kg/m/day以下であることが好ましく、3.0kg/m/day以下であることがより好ましく、2.5kg/m/day以下であることが特に好ましい。
(BOD volume load)
In the present invention, the BOD volume load of the water to be treated to the aeration tank is 0.8 to 4.0 kg/m 3 /day. Although "kg-BOD/m 3 /day" is sometimes used as a unit of BOD volume load, it is synonymous with "kg/m 3 /day" in this specification.
The water treatment apparatus of the present invention can treat water by increasing the BOD volume load on the aeration tank of the water to be treated. The lower limit of the BOD volume load is preferably 1.0 kg/m 3 /day or more, more preferably 1.2 kg/m 3 /day or more, and 1.5 kg/m 3 /day or more. is particularly preferred, and 2.0 kg/m 3 /day or more is more particularly preferred. However, when emphasizing high BOD volume load treatment while allowing high S-BOD in treated water and low S-BOD removal rate in biologically treated water, BOD volume load should be 2.5 kg/m 3 /day or more, and preferably 3.0 kg/m 3 /day or more.
By reducing the BOD volume load of the water to be treated to the aeration tank to some extent, the S-BOD of the treated water can be further reduced and the S-BOD treatment rate of the aeration tank can be increased. From this point of view, the upper limit of the BOD volume load is preferably 3.5 kg/m 3 /day or less, more preferably 3.0 kg/m 3 /day or less, and 2.5 kg/m 3 /day. The following are particularly preferred.

(その他の被処理水の水質)
被処理水のSS濃度は、例えば50~1000mg/Lであることが好ましく、200~500mg/Lであることがより好ましく、300~400mg/Lであることが特に好ましい。
被処理水のT-BOD(トータルBOD)は、例えば200~2000mg/Lであることが好ましく、600~1000mg/Lであることがより好ましく、800~900mg/Lであることが特に好ましい。
被処理水のS-BOD(溶解性BOD)は、例えば100~1000mg/Lであることが好ましく、300~500mg/Lであることがより好ましく、400~450mg/Lであることが特に好ましい。なお、S-BODとT-BODの関係は、以下のとおりである。
T-BODは全溶液中のBODであり、S-BODは懸濁物質を取り除いた後(JIS K0102 14.1懸濁物質測定方法に基づく)の溶解性BODである。
(Other quality of treated water)
The SS concentration of the water to be treated is, for example, preferably 50-1000 mg/L, more preferably 200-500 mg/L, and particularly preferably 300-400 mg/L.
The T-BOD (total BOD) of the water to be treated is, for example, preferably 200-2000 mg/L, more preferably 600-1000 mg/L, and particularly preferably 800-900 mg/L.
The S-BOD (soluble BOD) of the water to be treated is, for example, preferably 100-1000 mg/L, more preferably 300-500 mg/L, and particularly preferably 400-450 mg/L. The relationship between S-BOD and T-BOD is as follows.
T-BOD is the BOD in the total solution and S-BOD is the soluble BOD after removing the suspended solids (based on JIS K0102 14.1 Suspended solids determination method).

本発明の水処理装置は、被処理水の温度に制限はなく、高温の被処理水であっても、低温の被処理水であっても用いることもできる。低温の被処理水を用いることにより、設備管理および維持管理を簡便にすることができ、好ましい。例えば、低温の被処理水として、被処理水の温度が1~15℃である場合でも汚泥量を顕著に減らすことができ、かつ、BOD除去率を高くすることができる。特に、低温の被処理水の温度が5~12℃、特に7~11℃である場合にBOD除去率を高くすることができる。 The water treatment apparatus of the present invention is not limited to the temperature of the water to be treated, and can be used for both high-temperature water and low-temperature water. It is preferable to use low-temperature water to be treated, because facility management and maintenance can be simplified. For example, as low-temperature water to be treated, even when the temperature of water to be treated is 1 to 15° C., the amount of sludge can be significantly reduced and the BOD removal rate can be increased. In particular, when the temperature of the low-temperature water to be treated is 5 to 12°C, particularly 7 to 11°C, the BOD removal rate can be increased.

<曝気槽>
本発明の水処理装置は曝気槽を備える。また、本発明では、曝気槽が曝気手段および流動床担体を備える。
曝気槽の体積は特に制限はない。本発明では、流動床担体を用いて高BOD容積負荷処理を行うことにより、曝気槽の体積を小さくすることができ、曝気槽の設置に必要な敷地面積も小さくすることができる。
曝気槽の材質としては、コンクリート製、金属製、樹脂製などを挙げることができる。中でも、樹脂製であることが好ましく、例えば、塩化ビニルや繊維強化プラスチックなどを好ましく採用することができる。
<Aeration tank>
The water treatment apparatus of the present invention includes an aeration tank. Also, in the present invention, the aeration tank comprises an aeration means and a fluidized bed carrier.
The volume of the aeration tank is not particularly limited. In the present invention, by performing high BOD volume load treatment using a fluidized bed carrier, the volume of the aeration tank can be reduced, and the site area required for installation of the aeration tank can also be reduced.
Examples of materials for the aeration tank include concrete, metal, and resin. Among them, it is preferably made of resin, and for example, vinyl chloride, fiber-reinforced plastic, or the like can be preferably used.

(曝気手段)
曝気槽の曝気手段としては特に制限はなく、公知の曝気手段を用いることができる。
(Aeration means)
The aeration means for the aeration tank is not particularly limited, and known aeration means can be used.

(流動床担体)
曝気槽は流動床担体を備え、具体的には曝気槽に流動床担体が充填されることが好ましい。流動床担体は、流動状態で(固定されずに)充填されていることにより、高BOD容積負荷処理を行うことができ、好ましくは短時間でBOD低下ができる。
本発明では、流動床担体の充填率が40~50%であることが好ましく、45~50%であることがより好ましい。
流動床担体は、流動床担体の内部に微生物が密集できる形状や材質であることが、低水温(10℃前後)でも曝気槽での生物処理を可能とする観点からより好ましい。
(Fluid bed carrier)
Preferably, the aeration tank comprises a fluidized bed support, and in particular the aeration tank is packed with a fluidized bed support. The fluidized bed carrier is packed in a fluidized state (not fixed), so that high BOD volume load treatment can be performed, and preferably BOD can be lowered in a short time.
In the present invention, the packing rate of the fluidized bed carrier is preferably 40-50%, more preferably 45-50%.
It is more preferable that the fluidized bed carrier has a shape and material that allows the microorganisms to congregate inside the fluidized bed carrier from the viewpoint of enabling biological treatment in an aeration tank even at low water temperatures (around 10°C).

流動床担体の形状は、立方体(キューブ状)、直方体、柱状、短冊形、金平糖型、四面体、球体、サッカーボールのような形状等であることが好ましく、柱状であることがより好ましい。柱状とは、底面および上面が同じ形状であって、底面と上面をつなぐ側面を備える形状である。本発明では、流動床担体が、略円柱状であることが特に好ましい。略円柱状である場合、底面および上面は完全な円形状であっても、円の一部が変形した形状であっても、複数の円を平面的に重ねあわせた形状であってもよい。 The shape of the fluidized bed carrier is preferably cubic (cube-shaped), rectangular parallelepiped, columnar, strip-shaped, confetti-shaped, tetrahedral, spherical, soccer-ball-like shape, etc., and more preferably columnar. A columnar shape is a shape in which the bottom surface and the top surface have the same shape, and side surfaces connect the bottom surface and the top surface. In the present invention, it is particularly preferred that the fluidized bed carrier has a substantially cylindrical shape. In the case of a substantially cylindrical shape, the bottom surface and the top surface may be completely circular, partially deformed circles, or a plurality of overlapping circles in a plane.

流動床担体の材質としては、例えば樹脂、セラミックなどの無機物を用いることができる。流動床担体に用いられる樹脂としては、熱可塑性樹脂、熱硬化性樹脂、ゴム、エラストマー等を挙げることができる。
熱可塑性樹脂としては、ポリビニルアルコール樹脂、アクリル樹脂、メタクリル樹脂、酢酸ビニル樹脂、塩化ビニル樹脂、塩化ビニリデン樹脂、スチレン樹脂、エチレン酢酸ビニル樹脂、ABS樹脂、ポリエチレン、ポリプロピレン、ポリスチレン、ポリアセタール、ポリアミド樹脂、ポリエステル、ポリウレタン、及びそれらの共重合体などが使用できる。
熱硬化性樹脂としては、エポキシ樹脂、不飽和ポリエステル樹脂、フェノール樹脂、ユリア樹脂、メラミン樹脂、ポリウレタン樹脂、シリコン樹脂、ジアリルフタレート樹脂、及びそれらの共重合体などが使用できる。
ゴムとしては、天然ゴム、イソプレンゴム、ブタジエンゴム、ブチルゴム、エピクロロヒドリンゴム、NBR、MBR、CR、フッ素ゴム、アクリルゴム、シリコーンゴム、EPM、EPDM、及びそれらの共重合体などが使用できる。
エラストマーとしては、スチレン系エラストマー、ポリオレフィン系エラストマー、ポリウレタン系エラストマー、ポリエステル系エラストマー、ポリアミド系エラストマー、ポリブタジエン系エラストマー、及びそれらの共重合体などが使用できる。
上述した樹脂、ゴム、エラストマーは、単独で使用することもでき、また、2種類以上を混合して使用することもできる。
これらの中でも、熱可塑性樹脂が、高BOD容積負荷処理を行いやすい観点から好ましい。熱可塑性樹脂の中では、ポリビニルアルコール、ポリウレタン、ポリプロピレン、ポリエチレンを用いることがより好ましい。本発明では流動床担体がポリプロピレン製であることが特に好ましい。
Inorganic substances such as resins and ceramics can be used as materials for the fluidized bed carrier. Examples of resins used for the fluidized bed carrier include thermoplastic resins, thermosetting resins, rubbers, elastomers, and the like.
Examples of thermoplastic resins include polyvinyl alcohol resin, acrylic resin, methacrylic resin, vinyl acetate resin, vinyl chloride resin, vinylidene chloride resin, styrene resin, ethylene vinyl acetate resin, ABS resin, polyethylene, polypropylene, polystyrene, polyacetal, polyamide resin, Polyesters, polyurethanes, copolymers thereof, and the like can be used.
As thermosetting resins, epoxy resins, unsaturated polyester resins, phenol resins, urea resins, melamine resins, polyurethane resins, silicone resins, diallyl phthalate resins, and copolymers thereof can be used.
As the rubber, natural rubber, isoprene rubber, butadiene rubber, butyl rubber, epichlorohydrin rubber, NBR, MBR, CR, fluororubber, acrylic rubber, silicone rubber, EPM, EPDM, and copolymers thereof can be used.
Examples of elastomers that can be used include styrene elastomers, polyolefin elastomers, polyurethane elastomers, polyester elastomers, polyamide elastomers, polybutadiene elastomers, and copolymers thereof.
The resins, rubbers, and elastomers mentioned above can be used alone, or two or more of them can be mixed and used.
Among these, thermoplastic resins are preferable from the viewpoint of facilitating high BOD volume load treatment. Among thermoplastic resins, it is more preferable to use polyvinyl alcohol, polyurethane, polypropylene, and polyethylene. It is particularly preferred according to the invention that the fluidized bed carrier is made of polypropylene.

(スクリーン)
本発明では、曝気槽が、流動床担体の消化槽への移動を制限できるスクリーンを備えることが好ましい。この構成により、消化槽が担体を含まない状態を維持しやすくでき、消化槽でのBOD容積負荷を減らして、消化槽での汚泥減量の作用を高めることができる。スクリーンとしては特に制限はなく、膜状や筒状などの公知のスクリーンを用いることができる。
(screen)
In the present invention, the aeration tank is preferably equipped with a screen capable of restricting the movement of the fluidized bed carrier to the digestion tank. With this configuration, the digestion tank can be easily maintained in a carrier-free state, the BOD volume load in the digestion tank can be reduced, and the effect of reducing the amount of sludge in the digestion tank can be enhanced. The screen is not particularly limited, and known screens such as film-shaped and cylindrical screens can be used.

(曝気槽でのBOD除去率)
曝気槽でのBOD除去率を高くすることが、消化槽ではBOD除去率を低くすることができ、消化槽での汚泥減量の作用を高める観点から好ましい。
本発明では、曝気槽でのBOD除去率が70%以上であることが好ましく、80%以上であることがより好ましく、90%以上であることが特に好ましい。本発明の水処理装置では、被処理水の曝気槽に対するBOD容積負荷が0.8~4.0kg/m/dayと高い場合であっても、曝気槽でのBOD除去率を70%以上にすることができる。また、被処理水の曝気槽に対するBOD容積負荷が1.0~3.0kg/m/day程度の高い場合であれば、曝気槽でのBOD除去率を80%以上にすることができる。
さらに、本発明の水処理装置では、被処理水の水温が、例えば10℃前後と低温であっても、曝気槽でのBOD除去率を高くすることができる。
(BOD removal rate in aeration tank)
It is preferable to increase the BOD removal rate in the aeration tank from the viewpoint that the BOD removal rate in the digestion tank can be lowered and the sludge reduction effect in the digestion tank is enhanced.
In the present invention, the BOD removal rate in the aeration tank is preferably 70% or higher, more preferably 80% or higher, and particularly preferably 90% or higher. In the water treatment apparatus of the present invention, even when the BOD volume load on the aeration tank of the water to be treated is as high as 0.8 to 4.0 kg/m 3 /day, the BOD removal rate in the aeration tank is 70% or more. can be Further, when the BOD volume load of the water to be treated to the aeration tank is as high as about 1.0 to 3.0 kg/m 3 /day, the BOD removal rate in the aeration tank can be 80% or more.
Furthermore, in the water treatment apparatus of the present invention, the BOD removal rate in the aeration tank can be increased even if the temperature of the water to be treated is as low as, for example, around 10°C.

<消化槽>
本発明の水処理装置は消化槽を備える。また、本発明では、消化槽が曝気手段を備え、かつ、担体を含まない。消化槽が「担体を含まない」とは、厳密に担体となり得る物質を全く含まない場合に限定されることはなく、実質的に担体を含んでいなければよい。積極的に担体を添加する運用とせずに低コスト化でき、消化槽でのBOD除去率を低くして汚泥減量ができれば、本発明の解決しようとする課題は解決し得る。また、より効果的に汚泥の減量を行いたい場合は、担体を消化槽に投入するなどといった拡張も容易である。
消化槽を設けることにより、消化槽を設けない場合の汚泥量(単位:kg/day)を基準として、消化槽の後の汚泥量を5質量%以上減らせることが好ましく、10質量%以上減らせることがより好ましい。なお、消化槽を設けない場合の汚泥量は1.5kg/day以下であることが好ましい。また、消化槽の後の汚泥量は1.2kg/day以下であることが好ましい。
消化槽の体積は特に制限はない。例えば、消化槽の体積を、曝気槽の体積と同程度とする構成を挙げることができる。
消化槽の材質は特に制限はない。例えば、消化槽の材質を、曝気槽の材質と同じとする構成を挙げることができる。
<Digestion tank>
The water treatment apparatus of the present invention includes a digestion tank. Also, in the present invention, the digester is provided with aeration means and does not contain a carrier. The digestive tank "does not contain a carrier" is not strictly limited to the case where it does not contain any substance that can serve as a carrier, and it may contain substantially no carrier. The problem to be solved by the present invention can be solved if the cost can be reduced without actively adding a carrier, and if the BOD removal rate in the digestion tank can be lowered to reduce the amount of sludge. Moreover, when it is desired to reduce the amount of sludge more effectively, it is easy to extend the method by, for example, putting the carrier into the digestion tank.
By providing a digestion tank, it is preferable to reduce the amount of sludge after the digestion tank by 5% by mass or more, preferably by 10% by mass or more, based on the amount of sludge (unit: kg / day) when no digestion tank is provided. is more preferable. The amount of sludge when no digestion tank is provided is preferably 1.5 kg/day or less. Also, the amount of sludge after the digestion tank is preferably 1.2 kg/day or less.
The volume of the digester is not particularly limited. For example, a configuration in which the volume of the digestion tank is approximately the same as the volume of the aeration tank can be mentioned.
There are no particular restrictions on the material of the digester. For example, the digestion tank may be made of the same material as the aeration tank.

(曝気手段)
消化槽の曝気手段は、公知の曝気手段を用いてもよいが、間欠曝気できる曝気手段であることが好ましい。
また、消化槽は、曝気槽からの汚泥が消化槽に溜まるように曝気手段を間欠曝気できるように制御する制御手段を備えることが好ましい。消化槽で間欠曝気する構成とすることにより、曝気が停止している期間に汚泥の固形分が沈降し、消化槽に滞留する汚泥の密度が上昇するため汚泥消化を促進できる作用が生じ、下流の沈殿槽からの返送汚泥を無くすことができる。
一方、消化槽は発生汚泥量の多寡に応じて機能の使用不使用を選択可能であることが、設置スペースを調整する観点から好ましい。例えば、排水の状態によって汚泥量が想定より少ない場合等に、消化槽として区切ってある槽を消化槽以外の別の用途に転用することが可能である。その際は、曝気槽からの生物処理水をそのまま処理水として放流するか、沈殿槽に導入してもよい。
(Aeration means)
As the aeration means for the digestion tank, known aeration means may be used, but an aeration means capable of intermittent aeration is preferable.
The digester preferably also comprises control means for intermittently aerating the aeration means so that sludge from the aeration tank accumulates in the digester. By adopting a structure in which intermittent aeration is performed in the digestion tank, the solid content of the sludge settles during the period when the aeration is stopped, and the density of the sludge remaining in the digestion tank increases. The return sludge from the sedimentation tank can be eliminated.
On the other hand, it is preferable from the viewpoint of adjusting the installation space that the digestion tank can select whether or not to use the function according to the amount of generated sludge. For example, when the amount of sludge is less than expected due to the state of the wastewater, it is possible to divert the tanks separated as digestion tanks to other uses other than the digestion tank. In that case, the biologically treated water from the aeration tank may be discharged as it is as treated water, or may be introduced into the sedimentation tank.

<沈殿槽>
本発明の水処理装置は、消化槽の下流に沈殿槽を有することが好ましい。消化槽からの処理水は、沈殿槽に送液され、沈殿槽で固液分離された後に、海洋や河川等の外部領域に放出されるか、用水として回収および再利用されることが好ましい。
本発明の水処理装置は、沈殿槽から、曝気槽および消化槽の少なくとも一方に汚泥を返送する手段を備えないことが好ましい。汚泥を返送しないことにより、返送汚泥用の流路やポンプの設備コストおよびメンテナンスコストを低くすることができ、維持管理が容易となる。
<Sedimentation tank>
The water treatment apparatus of the present invention preferably has a sedimentation tank downstream of the digestion tank. It is preferable that the treated water from the digestion tank is sent to the sedimentation tank, solid-liquid separated in the sedimentation tank, and then discharged to an external area such as the ocean or a river, or recovered and reused as industrial water.
The water treatment apparatus of the present invention preferably does not have means for returning sludge from the sedimentation tank to at least one of the aeration tank and the digestion tank. By not returning the sludge, it is possible to reduce the facility cost and maintenance cost of the return sludge flow path and pump, thereby facilitating maintenance.

<その他の装置>
水処理装置は、その他の装置を有していてもよい。
水処理装置は、被処理水、生物処理水および処理水を送液するために、ポンプなどの公知の送液手段を備えることが好ましい。
水処理装置は、調整槽を備えることが好ましい。曝気槽の上流に調整槽を有する構成とすることで、被処理水の曝気槽に対するBOD容積負荷や、その他の被処理水の水質を制御しやすくなる。
水処理装置は、曝気槽と消化槽の間などに凝集分離手段を備えないことが、水処理装置自体をさらに簡素化でき、かつ、凝集剤に起因する薬品コストも生じない観点から好ましい。
水処理装置は洗浄設備を有していても、有していなくてもよい。流動床担体を洗浄する際には、水処理装置から流動床担体を取り出して洗浄してもよく、水処理装置内で逆流洗浄をしてもよく、洗濯機等によって負荷をかけて洗浄してもよい。水処理装置は洗浄設備を有さないことが水処理装置自体をさらに簡素化できて好ましい。流動床担体は優れた強度を有し、耐久性に優れていることが好ましく、耐久性に優れる流動床担体を用いる場合は、水処理装置は洗浄設備を有さないことが好ましい。
<Other devices>
The water treatment device may have other devices.
It is preferable that the water treatment apparatus is provided with a known liquid transfer means such as a pump in order to transfer the water to be treated, the biologically treated water and the treated water.
It is preferable that the water treatment apparatus include an adjustment tank. By providing the adjustment tank upstream of the aeration tank, it becomes easier to control the BOD volume load of the water to be treated on the aeration tank and other water qualities of the water to be treated.
It is preferable that the water treatment apparatus does not include a flocculating means between the aeration tank and the digestion tank, from the viewpoint of further simplifying the water treatment apparatus itself and not incurring chemical costs due to the flocculant.
The water treatment equipment may or may not have a washing facility. When washing the fluidized bed carrier, the fluidized bed carrier may be washed after being removed from the water treatment apparatus, or may be washed by backflow washing in the water treatment apparatus, or washed under load by a washing machine or the like. good too. It is preferable that the water treatment apparatus does not have a washing facility, because the water treatment apparatus itself can be further simplified. The fluidized bed carrier preferably has excellent strength and durability. When using a fluidized bed carrier with excellent durability, the water treatment apparatus preferably does not have a washing facility.

<処理水>
処理水のS-BOD(溶解性BOD)は、200mg/L以下であることが好ましく、150mg/L以下であることがより好ましく、100mg/L以下であることが特に好ましく、50mg/L以下であることがより特に好ましい。
<Treatment water>
The S-BOD (soluble BOD) of the treated water is preferably 200 mg/L or less, more preferably 150 mg/L or less, particularly preferably 100 mg/L or less, and 50 mg/L or less. It is more particularly preferred to have

[水処理方法]
本発明の水処理方法は、曝気槽および消化槽をこの順で備える水処理装置に被処理水を通過させる水処理方法であって;被処理水の曝気槽に対するBOD容積負荷が0.8~4.0kg/m/dayであり;曝気槽が曝気手段および流動床担体を備え;消化槽が曝気手段を備え、かつ、担体を含まない。
本発明の水処理方法の好ましい態様は、本発明の水処理方法の好ましい態様と同様である。
[Water treatment method]
The water treatment method of the present invention is a water treatment method in which water to be treated is passed through a water treatment apparatus comprising an aeration tank and a digestion tank in this order; 4.0 kg/m 3 /day; aeration tank with aeration means and fluidized bed carrier; digestion tank with aeration means and no carrier.
Preferred aspects of the water treatment method of the present invention are the same as the preferred aspects of the water treatment method of the present invention.

本発明の水処理方法では、曝気槽内に微生物が未固着の流動床担体を投入し、曝気槽に被処理水を通過させるだけで自動的に微生物を流動床担体に固着させることができる。そのため、流動床担体を、微生物を固着した担体とする工程は特に必要はない。 In the water treatment method of the present invention, the microorganisms can be automatically fixed to the fluidized-bed carrier simply by putting the fluidized-bed carrier to which microorganisms have not adhered into the aeration tank and allowing the water to be treated to pass through the aeration tank. Therefore, there is no particular need for a step of using a fluidized bed carrier as a carrier to which microorganisms are adhered.

以下に実施例と比較例を挙げて本発明の特徴をさらに具体的に説明する。以下の実施例に示す材料、使用量、割合、処理内容、処理手順等は、本発明の趣旨を逸脱しない限り適宜変更することができる。したがって、本発明の範囲は以下に示す具体例により限定的に解釈されるべきものではない。 EXAMPLES The characteristics of the present invention will be described more specifically below with reference to examples and comparative examples. The materials, amounts used, proportions, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the specific examples shown below.

[実施例1]
容積5Lの曝気槽と、容積5Lの消化槽と、容積2Lの沈殿槽を連結し、実施例1の水処理装置とした。
曝気槽として、略円柱状のポリプロピレン担体を収容した、流動床式の生物処理槽を用いた。曝気槽では、流動床担体の充填率を50%とした。消化槽への流路の前にスクリーンを設け、曝気槽から消化槽に流動床担体が移動しないようにした。
消化槽として、活性汚泥槽を用いた。消化槽は、汚泥を消化するための曝気手段を備えるものの、担体は収容しなかった。消化槽から曝気槽への汚泥返送は行わなかった。
被処理水として食品加工系排水を用いた。
実施例1の水処理装置で水処理を行った。実施例1では、BOD容積負荷を2.18kg-BOD/m/dayとした。まず、設定した容積負荷になるように被処理水の通水量を設定し、曝気槽に通水した。曝気槽で曝気を行い、流動床担体に微生物を保持させて、生物処理を行った。その後、曝気槽からのオーバーフローを生物処理水として消化槽に通水し、曝気装置で間欠曝気して、曝気槽からの汚泥をある程度溜めることと、汚泥を消化することを繰り返すように制御した。消化槽からのオーバーフロー分を沈殿槽に通水して、最終的に沈殿槽のオーバーフローを処理水として得た。沈殿槽から、曝気槽または消化槽への汚泥返送は行わなかった。
実施例1の水処理方法における被処理水のSS濃度、S-BOD(溶解性BOD)、T-BOD(トータルBOD)は下記表1のとおりであった。曝気槽からの生物処理水のS-BODを測定し、被処理水のS-BODを基準とする曝気槽S-BOD除去率を求め、下記表1に記載した。沈殿槽からの処理水のS-BODを測定し、下記表1に記載した。各BOD濃度はJIS K 0102 21に準拠して測定した。
実施例1の水処理における汚泥量を測定し、下記表1に記載した。消化槽の後の汚泥量は以下の方法で測定した。
沈殿槽下部から抜き出した汚泥を乾燥機で完全に乾燥させ、絶乾汚泥量を測定し、含水率を85%とした時の1日あたりの重量を算出した。
各パラメータの値は10日間程度の試験結果を平均して算出した。
なお、実施例1で用いた被処理水の水温は20℃であった。
[Example 1]
A 5 L volume aeration tank, a 5 L volume digestion tank, and a 2 L volume sedimentation tank were connected to form the water treatment apparatus of Example 1.
As the aeration tank, a fluidized bed biological treatment tank containing a substantially cylindrical polypropylene carrier was used. In the aeration tank, the filling rate of the fluidized bed carrier was set to 50%. A screen was installed in front of the flow path to the digester to prevent transfer of the fluidized bed carrier from the aeration tank to the digester.
An activated sludge tank was used as a digester. The digester was equipped with aeration means for digesting the sludge, but did not contain carriers. No sludge was returned from the digester to the aeration tank.
Food processing wastewater was used as the water to be treated.
Water treatment was performed using the water treatment apparatus of Example 1. In Example 1, the BOD volume load was set at 2.18 kg-BOD/m 3 /day. First, the flow rate of the water to be treated was set so as to achieve the set volumetric load, and the water was passed through the aeration tank. Aeration was carried out in an aeration tank to retain microorganisms in the fluidized bed carrier, and biological treatment was carried out. After that, the overflow from the aeration tank was passed through the digestion tank as biologically treated water, and intermittent aeration was performed by the aeration equipment, and the sludge from the aeration tank was accumulated to some extent, and the sludge was digested repeatedly. The overflow from the digestion tank was passed through the sedimentation tank, and finally the overflow of the sedimentation tank was obtained as treated water. There was no sludge return from the sedimentation tank to the aeration tank or the digester.
The SS concentration, S-BOD (soluble BOD), and T-BOD (total BOD) of the water to be treated in the water treatment method of Example 1 were as shown in Table 1 below. The S-BOD of the biologically treated water from the aeration tank was measured, and the S-BOD removal rate of the aeration tank based on the S-BOD of the water to be treated was determined and shown in Table 1 below. The S-BOD of the treated water from the sedimentation tank was measured and listed in Table 1 below. Each BOD concentration was measured according to JIS K 0102-21.
The amount of sludge in the water treatment of Example 1 was measured and shown in Table 1 below. The amount of sludge after the digestion tank was measured by the following method.
The sludge extracted from the lower part of the sedimentation tank was completely dried in a dryer, and the absolute dry sludge amount was measured to calculate the weight per day when the water content was 85%.
The value of each parameter was calculated by averaging the test results for about 10 days.
The water temperature of the water to be treated used in Example 1 was 20°C.

[実施例2]
BOD容積負荷を3.82kg/m/dayとした以外は実施例1と同様にして、水処理を行った。
[Example 2]
Water treatment was carried out in the same manner as in Example 1, except that the BOD volume load was 3.82 kg/m 3 /day.

[比較例1]
消化槽を備えない以外は実施例1の水処理装置と同様の比較例1の水処理装置を製造した。実施例1の水処理装置の代わりに、比較例1の水処理装置を用いた以外は実施例1と同様にして、水処理を行った。
消化槽を設けない場合の汚泥量は以下の方法で測定した。
実施例1と同様にして沈殿槽下部の絶乾汚泥量から含水率85%想定の1日当たりの汚泥量を算出した。
[Comparative Example 1]
A water treatment apparatus of Comparative Example 1 was manufactured in the same manner as the water treatment apparatus of Example 1 except that the digestion tank was not provided. Water treatment was performed in the same manner as in Example 1, except that the water treatment apparatus of Comparative Example 1 was used instead of the water treatment apparatus of Example 1.
The amount of sludge without a digestion tank was measured by the following method.
In the same manner as in Example 1, the amount of sludge per day assuming a moisture content of 85% was calculated from the absolute dry sludge amount at the bottom of the sedimentation tank.

Figure 0007230386000001
Figure 0007230386000001

以上の実施例および比較例より、本発明の水処理装置は、BODが高い被処理水を用いて高BOD容積負荷処理を行う場合に汚泥量を顕著に減らすことができ、かつ、低コストであることがわかった。一方、消化槽無しの比較例1の水処理装置を用いた場合、消化槽を設けた実施例1の水処理装置に比べて汚泥量が12質量%程度多かった。
さらに本発明の水処理装置の好ましい態様では、高BOD容積負荷処理を行う場合にS-BOD除去率を高くできることがわかった。実施例1および2の条件でそれぞれ排水の水処理を行った場合、BOD容積負荷2.18kg/m/dayの場合のBOD除去率は90%以上となり、BOD容積負荷3.82kg/m/dayの場合のBOD除去率は70%以上となった。
From the above examples and comparative examples, the water treatment apparatus of the present invention can significantly reduce the amount of sludge when performing high BOD volume load treatment using water to be treated with high BOD, and at low cost It turns out there is. On the other hand, when the water treatment apparatus of Comparative Example 1 without a digestion tank was used, the amount of sludge was about 12% by mass larger than that of the water treatment apparatus of Example 1 provided with a digestion tank.
Furthermore, it was found that in a preferred embodiment of the water treatment apparatus of the present invention, the S-BOD removal rate can be increased when performing high BOD volume load treatment. When the wastewater was treated under the conditions of Examples 1 and 2, respectively, the BOD removal rate was 90% or more when the BOD volume load was 2.18 kg/m 3 /day, and the BOD volume load was 3.82 kg/m 3 . /day, the BOD removal rate was 70% or more.

[実施例3~6]
BOD容積負荷および水温を下記表2のとおりとした以外は実施例1と同様にして、水処理を行った。その結果を下記表2に示した。
[Examples 3 to 6]
Water treatment was carried out in the same manner as in Example 1, except that the BOD volume load and water temperature were as shown in Table 2 below. The results are shown in Table 2 below.

Figure 0007230386000002
Figure 0007230386000002

上記表2より、本発明の水処理装置の好ましい態様では、BOD負荷が高い被処理水の水温が10℃前後であっても、S-BOD除去率を高くできることがわかった。曝気槽で流動床担体を用いることで、流動床担体内部の深くに微生物が密集できたため、被処理水の水温が低くてもS-BOD除去率を高くできたと考えられる。 From Table 2 above, it was found that in a preferred embodiment of the water treatment apparatus of the present invention, the S-BOD removal rate can be increased even when the temperature of the water to be treated with a high BOD load is around 10°C. It is considered that the use of the fluidized bed carrier in the aeration tank allowed the microorganisms to grow densely deep inside the fluidized bed carrier, resulting in a high S-BOD removal rate even when the temperature of the water to be treated was low.

1 被処理水
2 生物処理水
3 処理水
11 曝気槽
12 消化槽
13 沈殿槽
14 調整槽
21 担体
22 曝気手段
23 スクリーン
1 Water to be treated 2 Biologically treated water 3 Treated water 11 Aeration tank 12 Digestion tank 13 Sedimentation tank 14 Adjustment tank 21 Carrier 22 Aeration means 23 Screen

Claims (9)

曝気槽消化槽および沈殿槽をこの順で備える水処理装置であって;
被処理水の前記曝気槽に対するBOD容積負荷が0.8~4.0kg/m/dayであり;
前記被処理水の温度が5~12℃であり、
前記曝気槽が曝気手段および流動床担体を備え;
前記消化槽が曝気手段を備え、かつ、担体を含まず;
前記消化槽が曝気手段を間欠曝気できるように制御する制御手段を備え、
前記沈殿槽から、前記曝気槽および前記消化槽の少なくとも一方に汚泥を返送する手段を備えない、水処理装置。
A water treatment apparatus comprising an aeration tank , a digestion tank and a sedimentation tank in this order;
BOD volume load of the water to be treated on the aeration tank is 0.8 to 4.0 kg/m 3 /day;
The temperature of the water to be treated is 5 to 12 ° C.,
said aeration tank comprising an aeration means and a fluidized bed carrier;
said digester is equipped with aeration means and does not contain a carrier;
A control means for controlling the aeration means so that the digestion tank can perform intermittent aeration ,
A water treatment system comprising no means for returning sludge from said sedimentation tank to at least one of said aeration tank and said digestion tank .
前記曝気槽でのBOD除去率が70%以上である、請求項1に記載の水処理装置。 The water treatment apparatus according to claim 1, wherein the BOD removal rate in said aeration tank is 70% or more. 前記流動床担体の充填率が40~50%である、請求項1または2に記載の水処理装置。 3. The water treatment apparatus according to claim 1, wherein the fluidized bed carrier has a packing rate of 40 to 50%. 前記流動床担体がポリプロピレン製である、請求項1~3のいずれか一項に記載の水処理装置。 A water treatment apparatus according to any one of claims 1 to 3, wherein said fluidized bed carrier is made of polypropylene. 前記流動床担体が略円柱状である、請求項1~4のいずれか一項に記載の水処理装置。 The water treatment apparatus according to any one of claims 1 to 4, wherein the fluidized bed carrier is substantially cylindrical. 前記曝気槽が、前記流動床担体の前記消化槽への移動を制限できるスクリーンを備える、請求項1~5のいずれか一項に記載の水処理装置。 A water treatment apparatus according to any one of claims 1 to 5, wherein said aeration tank comprises a screen capable of restricting movement of said fluidized bed carrier to said digestion tank. 前記被処理水の前記曝気槽に対するBOD容積負荷が1.5~2.5kg/m/dayである、請求項1~6のいずれか一項に記載の水処理装置。 The water treatment apparatus according to any one of claims 1 to 6, wherein the BOD volumetric load of the water to be treated on the aeration tank is 1.5 to 2.5 kg/m 3 /day. 前記被処理水が食品加工系排水である、請求項1~7のいずれか一項に記載の水処理装置。 The water treatment apparatus according to any one of claims 1 to 7, wherein the water to be treated is food processing wastewater. 曝気槽消化槽および沈殿槽をこの順で備える水処理装置に被処理水を通過させる水処理方法であって;
前記被処理水の前記曝気槽に対するBOD容積負荷が0.8~4.0kg/m/dayであり;
前記被処理水の温度が5~12℃であり、
前記曝気槽が曝気手段および流動床担体を備え;
前記消化槽が曝気手段を備え、かつ、担体を含まず;
前記消化槽が曝気手段を間欠曝気できるように制御する制御手段を備え、
前記沈殿槽から、前記曝気槽および前記消化槽の少なくとも一方に汚泥を返送する手段を備えない、水処理方法。
A water treatment method for passing water to be treated through a water treatment apparatus comprising an aeration tank , a digestion tank and a sedimentation tank in this order;
BOD volume load on the aeration tank of the water to be treated is 0.8 to 4.0 kg/m 3 /day;
The temperature of the water to be treated is 5 to 12 ° C.,
said aeration tank comprising an aeration means and a fluidized bed carrier;
said digester is equipped with aeration means and does not contain a carrier;
A control means for controlling the aeration means so that the digestion tank can perform intermittent aeration ,
A water treatment method that does not include means for returning sludge from the sedimentation tank to at least one of the aeration tank and the digestion tank .
JP2018172879A 2018-09-14 2018-09-14 Water treatment device and water treatment method Active JP7230386B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2018172879A JP7230386B2 (en) 2018-09-14 2018-09-14 Water treatment device and water treatment method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2018172879A JP7230386B2 (en) 2018-09-14 2018-09-14 Water treatment device and water treatment method

Publications (2)

Publication Number Publication Date
JP2020044471A JP2020044471A (en) 2020-03-26
JP7230386B2 true JP7230386B2 (en) 2023-03-01

Family

ID=69900273

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2018172879A Active JP7230386B2 (en) 2018-09-14 2018-09-14 Water treatment device and water treatment method

Country Status (1)

Country Link
JP (1) JP7230386B2 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001347284A (en) 2000-06-08 2001-12-18 Kuraray Co Ltd Wastewater treatment method
JP2015071157A (en) 2013-09-03 2015-04-16 三菱レイヨン株式会社 Animal and vegetable oils-containing wastewater treatment system
JP2015116537A (en) 2013-12-18 2015-06-25 オルガノ株式会社 Biological treatment device and biological treatment method

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0615079B2 (en) * 1986-08-22 1994-03-02 荏原インフイルコ株式会社 Sewage treatment equipment

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001347284A (en) 2000-06-08 2001-12-18 Kuraray Co Ltd Wastewater treatment method
JP2015071157A (en) 2013-09-03 2015-04-16 三菱レイヨン株式会社 Animal and vegetable oils-containing wastewater treatment system
JP2015116537A (en) 2013-12-18 2015-06-25 オルガノ株式会社 Biological treatment device and biological treatment method

Also Published As

Publication number Publication date
JP2020044471A (en) 2020-03-26

Similar Documents

Publication Publication Date Title
TW311130B (en)
JP5208136B2 (en) Outside-tank membrane separation activated sludge method
JP6723920B2 (en) Membrane water treatment equipment, methods of incorporating adsorption to adsorbent powder materials, and means for limiting membrane wear
KR102620469B1 (en) Systems and methods for handling contaminated fluids with low environmental impact
NZ543478A (en) Apparatus and method for the treatment of waste
KR100807219B1 (en) Purification apparatus and method for high organic wastewater
JP2019068772A (en) Water treatment device and water treatment method
KR100992827B1 (en) Cleaning system for waste-water purifier
KR20140114586A (en) Sludge and Waste Water Treatment Apparatus of High Density and nitrogen treatment process using the same
US20140346125A1 (en) Desalting Salty Sludge System and Method
KR101594822B1 (en) The method and processing apparatus of the floating fish cage sludge using biological activated carbon
JP7230386B2 (en) Water treatment device and water treatment method
KR20190095151A (en) The water treatment system for fish breeding by applying membrane filtration process
CN104045206A (en) UV (ultraviolet)/O3+BAF (biological aerated filter) advanced oxidation sewage treatment facility
JP6899104B2 (en) Wastewater treatment method and wastewater treatment equipment
KR102122549B1 (en) water treating apparatus for sewage and wastewater
JP3607088B2 (en) Method and system for continuous simultaneous removal of nitrogen and suspended solids from wastewater
JP7119568B2 (en) Water treatment device and water treatment method
JP2000197895A (en) Water purifying treatment method and apparatus
JP4850015B2 (en) Outside-tank membrane separation activated sludge method
KR20030013491A (en) Sewage treatment system utilized bio-ball, bio-tank and lock-filter
KR100430034B1 (en) Waste water treatment system
KR102663413B1 (en) Method and system for supplying and filtering aquaculture water
JP7255341B2 (en) Water treatment device and water treatment method
KR20190004168A (en) A waste water of stock raising disposal plant

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20210806

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20220512

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20220517

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20220704

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20221004

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20221122

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20221124

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20230117

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20230130

R150 Certificate of patent or registration of utility model

Ref document number: 7230386

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150