JP6854381B1

JP6854381B1 - Denitrification tank repair method for human waste treatment facility

Info

Publication number: JP6854381B1
Application number: JP2020210988A
Authority: JP
Inventors: 友紀松田
Original assignee: Mitsubishi Heavy Industries Environmental and Chemical Engineering Co Ltd
Current assignee: Mitsubishi Heavy Industries Environmental and Chemical Engineering Co Ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-04-07
Anticipated expiration: 2040-12-21
Also published as: JP2022097821A

Abstract

【課題】し尿処理施設の延命化のため、施設の運転を継続しつつ、生物処理槽の中で最も上流に位置する脱窒素槽の補修を安価に実施する。
【解決手段】それぞれが別個の水槽で形成された脱窒素槽２と硝化槽３と沈殿槽４とを少なくとも備え、し尿を主成分とする被処理液を生物処理するし尿処理施設１において実施される脱窒素槽補修方法は、脱窒素槽２への被処理液の供給を停止し、脱窒素槽２を経由せずに被処理液を硝化槽３へ供給し、硝化槽３で被処理液の脱窒素及び硝化を行う第一工程と、硝化槽３から沈殿槽４へ被処理液を供給し、この供給経路において加水する第二工程と、沈殿槽４において被処理液から重力沈殿した沈殿液を硝化槽３へ返送する第三工程と、第一乃至第三工程を実施しつつ、脱窒素槽２を補修する第四工程とを有する。
【選択図】図３PROBLEM TO BE SOLVED: To repair a denitrification tank located at the most upstream of a biological treatment tank at a low cost while continuing the operation of the facility in order to prolong the life of the urine treatment facility.
SOLUTION: The urine treatment facility 1 is provided with at least a denitrification tank 2, a nitrification tank 3 and a settling tank 4 each of which is formed as a separate water tank, and biologically treats a liquid to be treated containing urine as a main component. In the denitrification tank repair method, the supply of the liquid to be treated to the denitrification tank 2 is stopped, the liquid to be treated is supplied to the nitrification tank 3 without passing through the denitrification tank 2, and the liquid to be treated is supplied in the nitrification tank 3. The first step of denitrifying and nitrifying, the second step of supplying the liquid to be treated from the nitrification tank 3 to the settling tank 4 and adding water in this supply path, and the precipitation caused by gravity precipitation from the liquid to be treated in the settling tank 4. It has a third step of returning the liquid to the nitrification tank 3 and a fourth step of repairing the denitrification tank 2 while carrying out the first to third steps.
[Selection diagram] Fig. 3

Description

本発明は、脱窒素槽と硝化槽とをそれぞれ別の水槽として備え、し尿を主成分とする被処理液を生物処理等するし尿処理施設の脱窒素槽補修方法に関する。 The present invention relates to a method for repairing a denitrification tank in a urine treatment facility, which comprises a denitrification tank and a nitrification tank as separate water tanks and biologically treats a liquid to be treated containing human waste as a main component.

し尿を主成分とする被処理液を生物処理するし尿処理施設においては、生物処理槽である脱窒素槽と硝化槽とが各々別個の水槽として設けられている場合がある。標準脱窒素処理方式のし尿処理施設では、一般的に、脱窒素槽と硝化槽とが各々別個の水槽に分離されている。例えば特許文献１に記載されているように、標準脱窒素処理方式の一種である二段脱窒素法（中間分離法）を用いるし尿処理施設でも、脱窒素槽と硝化槽とが各々別個の水槽に分離されている。 In a human waste treatment facility that biologically treats a liquid to be treated containing human waste as a main component, a denitrification tank and a nitrification tank, which are biological treatment tanks, may be provided as separate water tanks. In a standard denitrification treatment facility, the denitrification tank and the nitrification tank are generally separated into separate water tanks. For example, as described in Patent Document 1, even in a urine treatment facility that uses a two-stage denitrification method (intermediate separation method), which is a type of standard denitrification treatment method, the denitrification tank and the nitrification tank are separate water tanks. It is separated into.

特開昭６０−１５０８９８号公報Japanese Unexamined Patent Publication No. 60-150898

上記の特許文献１では、被処理液が投入される水槽の中で最も上流に位置する生物処理槽は、第一脱窒素槽である。第一脱窒素槽は、他の水槽に比べ、硫化水素などの腐食性ガスに曝されることから、水槽を形成するコンクリートが腐食して強度が低下する傾向にある。言い換えれば、生物処理槽の最も上流に位置する第一脱窒素槽は最も傷みやすく、第一脱窒素槽の下流に配置される各水槽は、第一脱窒素槽に比べ、痛みが少ない。従って、第一脱窒素槽を除く他の水槽は健全に使用できるにも関わらず、第一脱窒素槽のみ、補修が必要な場合がある。 In Patent Document 1 described above, the biological treatment tank located most upstream among the water tanks into which the liquid to be treated is charged is the first denitrification tank. Since the first denitrification tank is exposed to a corrosive gas such as hydrogen sulfide as compared with other water tanks, the concrete forming the water tank tends to corrode and its strength tends to decrease. In other words, the first denitrification tank located most upstream of the biological treatment tank is the most vulnerable, and each water tank located downstream of the first denitrification tank is less painful than the first denitrification tank. Therefore, although the other water tanks other than the first denitrification tank can be used soundly, only the first denitrification tank may need to be repaired.

ただし、第一脱窒素槽を補修する場合であっても、し尿処理施設の停止は回避しなければならない。そこで、第一脱窒素槽の代替え水槽を用意して、他の水槽と代替え水槽とを用いて施設の運転は継続しつつ、並行して第一脱窒素槽を補修する、という方法が考えられる。
しかし、し尿処理施設における水槽はいずれも大型であるため、第一脱窒素槽の補修時に代替え水槽を用いる方法では、大型の代替え水槽を設置するための敷地の確保や高額な製造費が必要となる。例えば、標準脱窒素処理方式の場合、各水槽は、被処理液（し尿等）の一日の処理量の１０倍程度を希釈するよう設計されている。このため、一日当り１００ｍ³の被処理液を処理する施設においては、第一脱窒素槽１０００ｍ³、硝化槽１０００ｍ³の水槽容量となり、第一脱窒素槽の代替え水槽も同等の水槽容量が必要であることから、代替え水槽を用いる方法では、製造コスト及び敷地確保のためのコストが高くならざるを得ない。 However, even when repairing the first denitrification tank, the shutdown of the urine treatment facility must be avoided. Therefore, it is conceivable to prepare an alternative water tank for the first denitrification tank and repair the first denitrification tank in parallel while continuing the operation of the facility using the other water tank and the alternative water tank. ..
However, since all the water tanks in the urine treatment facility are large, the method of using a substitute water tank when repairing the first denitrification tank requires securing a site for installing a large substitute water tank and high manufacturing costs. Become. For example, in the case of the standard denitrification treatment method, each water tank is designed to dilute about 10 times the daily treatment amount of the liquid to be treated (human waste, etc.). Therefore, in ^{a facility that treats 100 m 3} of the liquid to be treated per day, the capacity of the first denitrification tank is 1000 m ^{3 and} ^{the capacity of the nitrification tank is 1000 m 3} , and the alternative water tank of the first denitrification tank needs to have the same capacity. Therefore, in the method using the alternative water tank, the manufacturing cost and the cost for securing the site have to be high.

第一脱窒素槽を除く他の水槽は使用可能であるにも関わらず、代替え水槽を用いて第一脱窒素槽を補修するのに代えて、施設全体を放棄し、別途、新しい施設を設けるという選択も考えられる。
しかしながら、この選択は、経済性の観点から好ましくなく、やはり、施設の延命化を図り、より長期間の運転を継続できるよう、適切に補修することが望ましい。 Although other water tanks except the first denitrification tank can be used, instead of repairing the first denitrification tank with an alternative water tank, the entire facility is abandoned and a new facility is established separately. The choice is also conceivable.
However, this selection is not preferable from the viewpoint of economy, and it is still desirable to extend the life of the facility and appropriately repair it so that the operation can be continued for a longer period of time.

そこで、本発明では、し尿処理施設の延命化のため、施設の運転を継続しつつ、生物処理槽の中で最も上流に位置する脱窒素槽の補修を安価に実施することができる、し尿処理施設の脱窒素槽補修方法を提供することを目的とする。 Therefore, in the present invention, in order to prolong the life of the urine treatment facility, it is possible to inexpensively repair the denitrification tank located at the most upstream of the biological treatment tank while continuing the operation of the facility. The purpose is to provide a method for repairing the denitrification tank of the facility.

本発明のし尿処理施設の脱窒素槽補修方法は、それぞれが別個の水槽で形成された脱窒素槽と硝化槽と沈殿槽とを少なくとも備え、し尿を主成分とする第一被処理液を前記脱窒素槽に供給して脱窒素し、脱窒素した前記第一被処理液を前記脱窒素槽から前記硝化槽に供給して硝化し、硝化した前記第一被処理液を第二被処理液として前記硝化槽から前記沈殿槽に供給するし尿処理施設において、前記脱窒素槽への前記第一被処理液の供給を停止し、前記脱窒素槽を経由せずに前記第一被処理液を前記硝化槽へ供給し、前記硝化槽で前記第一被処理液の脱窒素及び硝化を行う第一工程と、前記硝化槽から前記沈殿槽へ前記第二被処理液を供給する際、前記第二被処理液の供給経路において加水する第二工程と、前記沈殿槽において前記第二被処理液から重力沈殿した沈殿液を、前記硝化槽へ返送する第三工程と、前記第一乃至第三工程を実施しつつ、前記脱窒素槽を補修する第四工程とを有する。
この補修方法では、脱窒素槽への第一被処理液の供給を停止し、代わりに硝化槽へ第一被処理液を供給して、硝化槽で脱窒素及び硝化の処理を行うので、脱窒素槽を空の水槽にして脱窒素槽の補修を容易にすることができる。また、脱窒素槽を使用せずに硝化槽で脱窒素と硝化の処理を行うため、第一被処理液の濃度が高まり、第一被処理液の粘性の増加や温度上昇があるが、第二被処理液の供給経路において加水するため、当該粘性や温度を低減することができる。そして、当該粘性や温度が低減した第二被処理液から得られる沈殿液を硝化槽へ返送するので、硝化槽において第一被処理液の粘性や温度を低減することができる。 The denitrification tank repair method of the human waste treatment facility of the present invention includes at least a denitrification tank, a nitrification tank, and a settling tank, each of which is formed as a separate water tank, and comprises the first liquid to be treated containing human waste as a main component. The first liquid to be treated, which was supplied to a denitrification tank to denitrify and denitrify, was supplied from the denitrification tank to the nitrification tank to be nitrogenized, and the nitrified first liquid to be treated was used as the second liquid to be treated. In the urine treatment facility where the nitrification tank is supplied to the settling tank, the supply of the first liquid to be treated to the denitrification tank is stopped, and the first liquid to be treated is supplied without passing through the denitrification tank. The first step of supplying to the nitrification tank and denitrifying and nitrifying the first liquid to be treated in the nitrification tank, and the first step of supplying the second liquid to be treated from the nitrification tank to the settling tank. (Ii) A second step of adding water in the supply path of the liquid to be treated, a third step of returning the precipitate liquid gravity-precipitated from the second liquid to be treated in the settling tank to the nitrification tank, and the first to third steps. It has a fourth step of repairing the denitrification tank while carrying out the step.
In this repair method, the supply of the first liquid to be treated to the denitrification tank is stopped, and instead, the first liquid to be treated is supplied to the nitrification tank, and the denitrification and nitrification treatments are performed in the nitrification tank. The nitrogen tank can be made an empty water tank to facilitate repair of the denitrification tank. Further, since the denitrification and nitrification treatments are performed in the nitrification tank without using the denitrification tank, the concentration of the first liquid to be treated increases, the viscosity of the first liquid to be treated increases, and the temperature rises. (Ii) Since water is added in the supply path of the liquid to be treated, the viscosity and temperature can be reduced. Then, since the precipitate liquid obtained from the second liquid to be treated whose viscosity and temperature have been reduced is returned to the nitrification tank, the viscosity and temperature of the first liquid to be treated can be reduced in the nitrification tank.

本発明によれば、し尿処理施設の延命化のため、し尿処理施設の運転を継続しつつ、生物処理槽の中で最も上流に位置する脱窒素槽の補修を安価に実施することができる。 According to the present invention, in order to prolong the life of the urine treatment facility, it is possible to inexpensively repair the denitrification tank located at the most upstream of the biological treatment tanks while continuing the operation of the urine treatment facility.

実施形態に係る脱窒素槽補修方法を適用可能なし尿処理施設の一例を示す概略図である。It is the schematic which shows an example of the urine processing facility to which the denitrification tank repair method which concerns on embodiment can be applied. 図１に示すし尿処理施設の第一脱窒素槽及び硝化槽の上面概略図である。FIG. 1 is a schematic top view of the first denitrification tank and the nitrification tank of the urine treatment facility shown in FIG. 図１に示すし尿処理施設に、実施形態に係る脱窒素槽補修方法を用いて第一仮設配管等を仮設した状態を示す概略図である。FIG. 5 is a schematic view showing a state in which a first temporary pipe or the like is temporarily installed in the urine treatment facility shown in FIG. 1 using the denitrification tank repair method according to the embodiment. 図３に示すし尿処理施設の第一脱窒素槽及び硝化槽の上面概略図である。FIG. 3 is a schematic top view of the first denitrification tank and the nitrification tank of the urine treatment facility shown in FIG. 図３の水中ポンプ周辺を拡大した模式図である。It is a schematic diagram which enlarged the periphery of the submersible pump of FIG.

以下、図面を参照して、本発明の実施形態であるし尿処理施設（以下「処理施設」という）の脱窒素槽補修方法について説明する。以下に示す構成や工程はあくまでも例示に過ぎず、明示しない種々の変形や技術の適用を排除する意図はない。以下に示す構成や工程は、本発明における必須の構成要件及びその趣旨を逸脱しない範囲で種々変形して実施することができる。 Hereinafter, a method for repairing a denitrification tank of a urine treatment facility (hereinafter referred to as “treatment facility”) according to an embodiment of the present invention will be described with reference to the drawings. The configurations and processes shown below are merely examples, and there is no intention to exclude the application of various modifications and techniques that are not specified. The configurations and steps shown below can be variously modified and implemented without departing from the essential configuration requirements and the gist of the present invention.

まず、本発明の脱窒素槽補修方法を適用可能な処理施設の一例として、標準脱窒素処理方式の一種である二段脱窒素法（中間分離法）が適用された処理施設１を説明する。
図１及び図２の処理施設１は、本発明の脱窒素槽補修方法を実施する前の処理施設を示す図である。脱窒素槽を補修する前の処理施設１は、予め設計された通り、処理施設１が備える各水槽を用いて通常の生物処理を行っているので、「通常運転時」の処理施設である。
一方、後述する図３〜図５は、本発明の脱窒素槽補修方法を実施して、第一脱窒素槽２を補修するときの処理施設１′の一部を示す図である。第一脱窒素槽２を補修するために後述の仮設配管等を仮設した処理施設１′は、生物処理に第一脱窒素槽２を使用せず、代わりに第一脱窒素槽２で行っていた脱窒素の機能を硝化槽３が兼ねる。すなわち、処理施設１の各水槽の一部が予め設計された通りの用法で使用されずに生物処理が行われるので、処理施設１′は、「補修時」の処理施設である。なお、図３に図示していない処理施設１′の構成は、図１の「通常運転時」の処理施設１の構成と同一である。 First, as an example of a treatment facility to which the denitrification tank repair method of the present invention can be applied, a treatment facility 1 to which a two-stage denitrification method (intermediate separation method), which is a kind of standard denitrification treatment method, is applied will be described.
The treatment facility 1 of FIGS. 1 and 2 is a diagram showing a treatment facility before carrying out the denitrification tank repair method of the present invention. The treatment facility 1 before repairing the denitrification tank is a treatment facility during "normal operation" because normal biological treatment is performed using each water tank provided in the treatment facility 1 as designed in advance.
On the other hand, FIGS. 3 to 5 described later are views showing a part of the treatment facility 1'when the first denitrification tank 2 is repaired by carrying out the denitrification tank repair method of the present invention. The treatment facility 1', in which a temporary pipe or the like described later is temporarily installed to repair the first denitrification tank 2, does not use the first denitrification tank 2 for biological treatment, but instead uses the first denitrification tank 2. The nitrification tank 3 also has the function of denitrifying. That is, the treatment facility 1'is a treatment facility "at the time of repair" because a part of each water tank of the treatment facility 1 is not used in the pre-designed usage and the biological treatment is performed. The configuration of the processing facility 1'not shown in FIG. 3 is the same as the configuration of the processing facility 1 in the "normal operation" of FIG.

図１に示す「通常運転時」の処理施設１は、二段脱窒素法が適用された処理施設であるので、前段として、供給管１０を介して供給される第一被処理液を脱窒素する第一脱窒素槽２と、当該脱窒素された第一被処理液が第一脱窒素槽２の備える排出管２ｅを介して供給され且つ当該供給された第一被処理液を硝化する硝化槽３と、当該硝化された第一被処理液が第二被処理液として硝化槽３の備える排出管３ｅを介して供給され且つ当該第二被処理液から沈殿液（第一沈殿液）を分離する沈殿槽（第一沈殿槽）４とを備える。
第一沈殿槽４は、整流筒４ｃを備えているので、第一沈殿槽４に注液される第二被処理液の流れを緩和し、当該第二被処理液からの第一沈殿液の分離を促進する。また、第一沈殿槽４は、排出管４ｅを備え、第一沈殿液が分離された第二被処理液は、第三被処理液として排出管４ｅから排出される。 Since the treatment facility 1 during "normal operation" shown in FIG. 1 is a treatment facility to which the two-stage denitrification method is applied, the first treatment liquid supplied via the supply pipe 10 is denitrified as the first stage. The first denitrification tank 2 and the denitrified first treatment liquid are supplied via the discharge pipe 2e provided in the first denitrification tank 2 and nitrify the supplied first treatment liquid. The tank 3 and the nitrified first treatment liquid are supplied as the second treatment liquid through the discharge pipe 3e provided in the nitrification tank 3, and the precipitation liquid (first precipitation liquid) is supplied from the second treatment liquid. A settling tank (first settling tank) 4 for separation is provided.
Since the first settling tank 4 includes the rectifying cylinder 4c, the flow of the second settling liquid injected into the first settling tank 4 is relaxed, and the first settling liquid from the second settling liquid is relaxed. Promote separation. Further, the first settling tank 4 includes a discharge pipe 4e, and the second liquid to be treated from which the first settling liquid is separated is discharged from the discharge pipe 4e as the third liquid to be treated.

なお、第一沈殿液は、第一ポンプ１４により圧送されて、第一沈殿槽４の底部に接続された返送配管１２を介して第一脱窒素槽２に返送される。また、硝化槽３で硝化された第一被処理液は、第二ポンプ１５により圧送されて、循環配管１１を介して硝化槽３から第一脱窒素槽２に循環される。
また、硝化槽３は、硝化のための散気装置３ｂを備えている。散気装置３ｂの空気溶解効率は、例えば６〜８％程度である。硝化槽３の構造は、図２を用いて後述する。
ここで、上記前段の各水槽２〜４はそれぞれ独立した別個の水槽として設けられる。第一被処理液はし尿を主成分とする液であり、し尿のみで形成された液でもよいし、し尿以外の成分（例えば、紙など）を含んで形成された液でもよい。 The first settling liquid is pumped by the first pump 14 and returned to the first denitrification tank 2 via the return pipe 12 connected to the bottom of the first settling tank 4. Further, the first liquid to be treated that has been nitrified in the nitrification tank 3 is pumped by the second pump 15 and circulated from the nitrification tank 3 to the first denitrification tank 2 via the circulation pipe 11.
Further, the nitrification tank 3 is provided with an air diffuser 3b for nitrification. The air dissolution efficiency of the air diffuser 3b is, for example, about 6 to 8%. The structure of the nitrification tank 3 will be described later with reference to FIG.
Here, each of the water tanks 2 to 4 in the preceding stage is provided as an independent and separate water tank. The first liquid to be treated is a liquid containing human waste as a main component, and may be a liquid formed only of human waste or a liquid formed containing components other than human waste (for example, paper).

二段脱窒素法が適用された処理施設１の前段は上述の構成であるが、後段は以下の構成である。すなわち、図１に示すように、処理施設１は、後段として、前段の第一沈殿槽４で排出管４ｅから排出された第三被処理液を脱窒素する第二脱窒素槽５と、当該脱窒素された第三被処理液が第二脱窒素槽５の備える排出管５ｅを介して供給され且つ当該供給された第三被処理液を曝気する再曝気槽６と、当該曝気された第三被処理液が第四被処理液として再曝気槽６の備える排出管６ｅを介して供給され且つ当該第四被処理液から沈殿液（第二沈殿液）を分離する第二沈殿槽７とを備える。第二沈殿槽７は、整流筒７ｃを備えているので、第二沈殿槽７に注液される第四被処理液の流れを緩和し、当該第四被処理液からの第二沈殿液の分離を促進する。
第二沈殿槽７は、排出管７ｅを備え、第二沈殿液が分離された第四被処理液は、第五被処理液として排出管７ｅから排出され、後処理施設（図示せず）に供給される。 The first stage of the treatment facility 1 to which the two-stage denitrification method is applied has the above-mentioned configuration, while the second stage has the following configuration. That is, as shown in FIG. 1, the treatment facility 1 has a second denitrification tank 5 for denitrifying the third liquid to be treated discharged from the discharge pipe 4e in the first settling tank 4 in the previous stage as a subsequent stage. A re-aeration tank 6 in which the denitrified third treatment liquid is supplied through the discharge pipe 5e provided in the second denitrification tank 5 and aerates the supplied third treatment liquid, and the aerated first. (3) With the second settling tank 7 in which the liquid to be treated is supplied as the fourth liquid to be treated via the discharge pipe 6e provided in the reaeration tank 6 and the precipitate liquid (second sediment liquid) is separated from the fourth liquid to be treated. To be equipped. Since the second settling tank 7 includes the rectifying cylinder 7c, the flow of the fourth settling liquid injected into the second settling tank 7 is relaxed, and the second settling liquid from the fourth settling liquid is relaxed. Promote separation.
The second settling tank 7 is provided with a discharge pipe 7e, and the fourth liquid to be treated from which the second sediment is separated is discharged from the discharge pipe 7e as the fifth liquid to be treated and sent to a post-treatment facility (not shown). Be supplied.

なお、第二沈殿液は、第三ポンプ１６により圧送されて、第二沈殿槽７の底部に接続された第二返送配管１３を介して第二脱窒素槽５に返送される。再曝気槽６は、図示しない散気装置を備えている。
ここで、上記後段の各水槽５〜７はそれぞれ独立した別個の水槽として設けられる。 The second settling liquid is pumped by the third pump 16 and returned to the second denitrification tank 5 via the second return pipe 13 connected to the bottom of the second settling tank 7. The re-aeration tank 6 includes an air diffuser (not shown).
Here, each of the water tanks 5 to 7 in the latter stage is provided as an independent and separate water tank.

処理施設１の硝化槽３は、図２に示すように、上面から見て略方形の硝化槽３の内部において、第一被処理液が流入する上流から、第一被処理液が流出する下流までの距離を、できるだけ大きくするように、当該上流と当該下流とを仕切る仕切壁３ａが設けられている。仕切壁３ａは、硝化槽３の略方形の１つの壁に接続し且つ当該壁に対面する壁に向かって垂直に伸びる壁であるが、当該対面する壁には接続はしない。
具体的には、仕切壁３ａは、硝化槽３の略方形の内部を当該上流の側（上流側）の半分と当該下流の側（下流側）の半分とに仕切り、当該上流側から当該下流側へ第一被処理液が流れる構造となっている。
これにより、硝化槽３の内部の第一被処理液は、図中破線矢印で示すように、当該内部の上流側から下流側に向かって、仕切壁３ａを迂回するように流れる。図２では、散気装置３ｂは、仕切壁３ａを挟んだ当該上流側と当該下流側の二箇所に配置されている。しかし、散気装置３ｂの位置や個数はこれに限られない。「通常運転時」の処理施設１では、散気装置３ｂにより第一被処理液を曝気することで、硝化槽３の内部の上流側と下流側の全域で、第一被処理液の硝化を行う。 As shown in FIG. 2, the nitrification tank 3 of the treatment facility 1 is inside the nitrification tank 3 which is substantially square when viewed from above, from the upstream where the first liquid to be treated flows in to the downstream where the first liquid to be treated flows out. A partition wall 3a that separates the upstream and the downstream is provided so as to make the distance to the distance as large as possible. The partition wall 3a is a wall that is connected to one of the substantially rectangular walls of the nitrification tank 3 and extends vertically toward the wall facing the wall, but is not connected to the facing wall.
Specifically, the partition wall 3a divides the inside of the substantially square shape of the nitrification tank 3 into a half of the upstream side (upstream side) and a half of the downstream side (downstream side), and from the upstream side to the downstream side. The structure is such that the first liquid to be treated flows to the side.
As a result, the first liquid to be treated inside the nitrification tank 3 flows so as to bypass the partition wall 3a from the upstream side to the downstream side of the inside as shown by the broken line arrow in the figure. In FIG. 2, the air diffuser 3b is arranged at two locations, the upstream side and the downstream side, sandwiching the partition wall 3a. However, the position and number of the air diffuser 3b are not limited to this. In the treatment facility 1 during "normal operation", the first liquid to be treated is aerated by the air diffuser 3b to nitrify the first liquid to be treated in the entire area upstream and downstream inside the nitrification tank 3. Do.

なお、処理施設１の第一脱窒素槽２も硝化槽３と同様の構造である。すなわち、上面から見て略方形の第一脱窒素槽２の内部に、第一被処理液が流入する上流から、第一被処理液が流出する下流までの距離を、できるだけ大きくするように、当該上流と当該下流とを仕切る仕切壁２ａが設けられている。 The first denitrification tank 2 of the treatment facility 1 has the same structure as the nitrification tank 3. That is, the distance from the upstream where the first liquid to be treated flows into the inside of the first denitrification tank 2 which is substantially square when viewed from the upper surface to the downstream where the first liquid to be treated flows out is made as large as possible. A partition wall 2a that separates the upstream and the downstream is provided.

では、図３、図４、及び図５を用いて、上述した「通常運転時」の処理施設１に、本実施形態の脱窒素槽補修方法を適用した処理施設１′、すなわち「補修時」の処理施設１′の説明を行う。
本実施形態の脱窒素槽補修方法は、少なくとも第一工程乃至第四工程の四つの工程を含む。 Then, using FIGS. 3, 4, and 5, the treatment facility 1'in which the denitrification tank repair method of the present embodiment is applied to the above-mentioned "normal operation" treatment facility 1, that is, "during repair". The processing facility 1'of the above will be described.
The denitrification tank repair method of the present embodiment includes at least four steps of the first step to the fourth step.

第一工程は、第一脱窒素槽２への第一被処理液の供給を停止し、第一脱窒素槽２を経由せずに第一被処理液を硝化槽３へ供給し、硝化槽３で第一被処理液の脱窒素及び硝化を行う工程である。
図２に示す硝化槽３で第一被処理液の脱窒素及び硝化を行う際は、硝化槽３の内部の上流側に配置した散気装置３ｂは停止（若しくは散気量を減少させる）し、下流側に配置した散気装置３ｂを動作させる。これにより、当該上流側で第一被処理液の脱窒素を行い、当該下流側で第一被処理液の硝化を行うことができる。なお、下流側に配置した散気装置３ｂは、硝化の効率を向上するために、後述の高効率な散気装置２４に交換するのが望ましい。
この工程により、第一脱窒素槽２を空の水槽とすることが可能になる。また、硝化槽３において、第一脱窒素槽２で行っていた脱窒素の処理と、もともと硝化槽３で行っていた硝化の処理の両方の処理を行うことができるので、第一脱窒素槽２を使用せずに、「通常運転時」と同様の生物処理を行うことができる。 In the first step, the supply of the first liquid to be treated to the first denitrification tank 2 is stopped, the first liquid to be treated is supplied to the nitrification tank 3 without passing through the first denitrification tank 2, and the nitrification tank is used. In step 3, the first liquid to be treated is denitrified and nitrified.
When the first liquid to be treated is denitrified and nitrified in the nitrification tank 3 shown in FIG. 2, the air diffuser 3b arranged on the upstream side inside the nitrification tank 3 is stopped (or the amount of air diffused is reduced). , Operate the air diffuser 3b arranged on the downstream side. As a result, the first liquid to be treated can be denitrified on the upstream side, and the first liquid to be treated can be nitrified on the downstream side. It is desirable that the air diffuser 3b arranged on the downstream side be replaced with a highly efficient air diffuser 24 described later in order to improve the efficiency of nitrification.
This step makes it possible to make the first denitrification tank 2 an empty water tank. Further, in the nitrification tank 3, both the denitrification treatment performed in the first denitrification tank 2 and the nitrification treatment originally performed in the nitrification tank 3 can be performed, so that the first denitrification tank 3 can be used. It is possible to carry out the same biological treatment as in "normal operation" without using 2.

第二工程は、硝化槽３から第一沈殿槽４へ第二被処理液を供給する際、第二被処理液の供給経路２５において水を供給、すなわち、供給経路２５の途中で第二被処理液に加水する工程である。
第一工程において、脱窒素槽２を使用せず、代わりに脱窒素槽２で行っていた脱窒素の処理を、硝化槽３で硝化の処理と併せて行う。言い換えれば、「通常運転時」の処理施設１では第一脱窒素槽２と硝化槽３の二つの水槽の各々で脱窒素と硝化の処理をそれぞれ行っていたが、「補修時」の処理施設１′では、硝化槽３、すなわち１つの水槽で脱窒素と硝化の処理を行う。
このため、例えば、「通常運転時」の処理施設１において、第一脱窒素槽２と硝化槽３の二つの水槽で第一被処理液を生物処理する際に、活性汚泥浮遊物質ＭＬＳＳ（Mixed Liquor Suspended Solid）が６０００ｍｇ／Ｌである場合、「補修時」の処理施設１′における硝化槽３のみでこの活性汚泥浮遊物質を含む第一被処理液の生物処理を行うには、ＭＬＳＳが２倍の１２０００ｍｇ／Ｌの濃度となる。硝化槽３に貯留された第一被処理液に含まれるＭＬＳＳの濃度が高い状態では、第一被処理液の粘性が増加して発泡し、また、第一被処理液の温度が上昇する可能性がある。
そして、硝化槽３で硝化された第一被処理液を第二被処理液として下流の水槽（直近の水槽は第一沈殿槽４）に供給するが、粘性や温度が高い第二被処理液を下流の水槽に供給すると、下流の複数の水槽におけるそれぞれの処理に悪影響を与える恐れがある。
しかし、第一工程では、供給経路２５において第二被処理液に加水し、第二被処理液の粘性や温度を低減することができるので、当該影響を抑制することができる。 In the second step, when the second liquid to be treated is supplied from the nitrification tank 3 to the first settling tank 4, water is supplied in the supply path 25 of the second liquid to be treated, that is, the second coating is supplied in the middle of the supply path 25. This is a step of adding water to the treatment liquid.
In the first step, the denitrification tank 2 is not used, and instead, the denitrification treatment performed in the denitrification tank 2 is performed together with the nitrification treatment in the nitrification tank 3. In other words, in the treatment facility 1 during "normal operation", denitrification and nitrification treatments were performed in each of the two water tanks, the first denitrification tank 2 and the nitrification tank 3, respectively, but the treatment facility during "repair" In 1', the denitrification and nitrification treatments are performed in the nitrification tank 3, that is, one water tank.
Therefore, for example, in the treatment facility 1 during "normal operation", when the first liquid to be treated is biologically treated in the two water tanks of the first denitrification tank 2 and the nitrification tank 3, the active sludge floating substance MLSS (Mixed) is used. When Liquor Suspended Solid) is 6000 mg / L, MLSS is 2 in order to perform biological treatment of the first liquid to be treated containing this active sludge suspended substance only in the nitrification tank 3 in the treatment facility 1'at the time of "repair". The concentration is doubled to 12000 mg / L. When the concentration of MLSS contained in the first liquid to be treated stored in the nitrification tank 3 is high, the viscosity of the first liquid to be treated may increase and foam, and the temperature of the first liquid to be treated may rise. There is sex.
Then, the first liquid to be treated that has been nitrified in the nitrification tank 3 is supplied as the second liquid to be treated to the downstream water tank (the nearest water tank is the first sedimentation tank 4), but the second liquid to be treated has a high viscosity and temperature. May adversely affect the treatment of each of the multiple downstream tanks.
However, in the first step, water is added to the second liquid to be treated in the supply path 25 to reduce the viscosity and temperature of the second liquid to be treated, so that the influence can be suppressed.

第三工程は、第一沈殿槽４において、第二被処理液から重力沈殿した沈殿液を硝化槽３へ返送する工程である。
第一沈殿槽４に貯留された第二被処理液は、第二工程において加水されて粘性や温度が低減されているので、その沈殿液の粘性や温度も低減している。従って、沈殿液を硝化槽３へ返送することで、硝化槽３内の第二被処理液の粘性の増加や温度上昇を抑制することができる。 The third step is a step of returning the precipitation liquid gravity-precipitated from the second liquid to be treated to the nitrification tank 3 in the first settling tank 4.
Since the second liquid to be treated stored in the first settling tank 4 is hydrated in the second step to reduce its viscosity and temperature, the viscosity and temperature of the settling liquid are also reduced. Therefore, by returning the precipitate liquid to the nitrification tank 3, it is possible to suppress an increase in viscosity and a temperature rise of the second liquid to be treated in the nitrification tank 3.

第四工程は、第一乃至第三工程を実施しつつ、第一脱窒素槽２を補修する工程である。
第一乃至第三工程を実施することで、第一脱窒素槽２を空の水槽にして補修しても、「通常運転時」の処理施設１と同様の生物処理を、「補修時」の処理施設１′で継続して行うことができる。
第一脱窒素槽２を空の水槽（空水槽）にする際は、第一脱窒素槽２に残留する第一被処理液を、ポンプ等で排出すればよい。
なお、第一脱窒素槽２の補修は、例えば、第一脱窒素槽２のコンクリートの壁面に生じたひび割れや、当該壁面からコンクリートの一部が剥離した損傷箇所に、セメント等を塗り込んで固めればよい。これにより、第一脱窒素槽２の壁面を新設時と同様の滑らかな壁面に修復することができる。 The fourth step is a step of repairing the first denitrification tank 2 while carrying out the first to third steps.
By carrying out the first to third steps, even if the first denitrification tank 2 is repaired as an empty water tank, the same biological treatment as that of the treatment facility 1 during "normal operation" can be performed during "repair". It can be continued at the processing facility 1'.
When the first denitrification tank 2 is made into an empty water tank (empty water tank), the first liquid to be treated remaining in the first denitrification tank 2 may be discharged by a pump or the like.
In the repair of the first denitrification tank 2, for example, cement or the like is applied to a crack generated on the concrete wall surface of the first denitrification tank 2 or a damaged part where a part of the concrete is peeled off from the wall surface. You just have to harden it. As a result, the wall surface of the first denitrification tank 2 can be restored to a smooth wall surface similar to that at the time of new installation.

上述の第一乃至第四工程の四つの工程のうち、第一工程、第二工程、及び、第三工程の各々は、それぞれ仮設工程を備える。そこで、以下、第一乃至第三工程が備える仮設工程について詳述する。
まず、第一工程が備える仮設工程について説明する。
第一工程は、図３及び図４に示すように、供給管１０と硝化槽３とを接続し、且つ、第一仮設配管バルブ２１Ｖを備えた第一仮設配管２１を配置する第一仮設工程と、供給管１０において、第一仮設配管２１及び供給管１０の接続点と第一脱窒素槽２との間に供給管仮設バルブ１０Ｖを配置する第二仮設工程とを備えている。
供給管仮設バルブ１０Ｖが開弁されると、第一被処理液が供給管１０を介して第一脱窒素槽２に供給される。一方、供給管仮設バルブ１０Ｖが閉弁されると、第一脱窒素槽２への第一被処理液の供給が停止される。
第一仮設配管バルブ２１Ｖが開弁されると、供給管１０から第一仮設配管２１を介して、第一被処理液が硝化槽３の内部における上記上流側の最も上流付近へ供給される。また、第一仮設配管バルブ２１Ｖが閉弁されると、硝化槽３への第一被処理液の供給が停止される。 Of the above-mentioned four steps of the first to fourth steps, each of the first step, the second step, and the third step includes a temporary step. Therefore, the temporary steps provided in the first to third steps will be described in detail below.
First, the temporary process provided in the first process will be described.
The first step is a first temporary step of connecting the supply pipe 10 and the vitrification tank 3 and arranging the first temporary pipe 21 provided with the first temporary pipe valve 21V, as shown in FIGS. 3 and 4. The supply pipe 10 includes a second temporary step of arranging the supply pipe temporary valve 10V between the connection point of the first temporary pipe 21 and the supply pipe 10 and the first denitrification tank 2.
When the temporary supply pipe valve 10V is opened, the first liquid to be treated is supplied to the first denitrification tank 2 via the supply pipe 10. On the other hand, when the temporary supply pipe valve 10V is closed, the supply of the first liquid to be treated to the first denitrification tank 2 is stopped.
When the first temporary pipe valve 21V is opened, the first liquid to be treated is supplied from the supply pipe 10 to the nearest upstream side on the upstream side inside the nitrification tank 3 via the first temporary pipe 21. Further, when the first temporary piping valve 21V is closed, the supply of the first liquid to be treated to the nitrification tank 3 is stopped.

ここで、第三仮設工程と第四仮設工程は、第三工程の備える仮設工程であるので、後述する。
では、次に、第一工程がさらに備える第五仮設工程と第六仮設工程と第七仮設工程を説明する。 Here, since the third temporary step and the fourth temporary step are temporary steps provided in the third step, they will be described later.
Next, the fifth temporary step, the sixth temporary step, and the seventh temporary step further provided by the first step will be described.

第一工程は、循環配管１１に循環配管仮設バルブ１１Ｖを配置する第五仮設工程と、循環配管１１における循環配管仮設バルブ１１Ｖ及び第二ポンプ１５の間と硝化槽３の内部における上流とを接続し、且つ、第三仮設配管バルブ２３Ｖを備えた第三仮設配管２３を配置する第六仮設工程とを備える。
循環配管仮設バルブ１１Ｖが開弁されると、硝化槽３で硝化された第一被処理液、すなわち、硝化槽３の内部において上記下流側の最も下流付近に存在する第二被処理液が循環配管１１を介して硝化槽３から第一脱窒素槽２に供給される。一方、循環配管仮設バルブ１１Ｖが閉弁されると、第一脱窒素槽２への第二被処理液の供給が停止される。
第三仮設配管バルブ２３Ｖが開弁されると、硝化槽３の内部において上記最も下流付近に存在する第二被処理液が、循環配管１１及び第三仮設配管２３を介して、硝化槽３の内部における上記上流側の最も上流付近に供給される。一方、第三仮設配管バルブ２３Ｖが閉弁されると、当該上流付近への第二被処理液の供給が停止される。 In the first step, the fifth temporary step of arranging the circulation pipe temporary valve 11V in the circulation pipe 11 and the connection between the circulation pipe temporary valve 11V and the second pump 15 in the circulation pipe 11 and the upstream inside the vitrification tank 3 are connected. In addition, a sixth temporary step of arranging the third temporary pipe 23 provided with the third temporary pipe valve 23V is provided.
When the temporary valve 11V for the circulation pipe is opened, the first liquid to be treated that has been nitrified in the nitrification tank 3, that is, the second liquid to be treated that exists in the most downstream side of the nitrification tank 3 is circulated. It is supplied from the nitrification tank 3 to the first denitrification tank 2 via the pipe 11. On the other hand, when the temporary circulation pipe valve 11V is closed, the supply of the second liquid to be treated to the first denitrification tank 2 is stopped.
When the third temporary pipe valve 23V is opened, the second liquid to be treated, which exists in the most downstream portion inside the nitrification tank 3, passes through the circulation pipe 11 and the third temporary pipe 23 to the nitrification tank 3. It is supplied to the vicinity of the most upstream side on the upstream side inside. On the other hand, when the third temporary piping valve 23V is closed, the supply of the second liquid to be treated to the vicinity of the upstream is stopped.

上述のとおり、「通常運転時」の処理施設１では第一脱窒素槽２と硝化槽３の二つの水槽の各々で脱窒素と硝化の処理をそれぞれ行っていたが、「補修時」の処理施設１′では、硝化槽３、すなわち１つの水槽で脱窒素と硝化の処理を行う。このため、第一脱窒素槽２と硝化槽３の二つの水槽で行っていた脱窒素と硝化の処理に要する第一被処理液の滞留時間（反応時間）と比べて、硝化槽３で脱窒素と硝化の処理を行う場合の滞留時間は短くなり、「補修時」の処理施設１′では脱窒素と硝化の処理が不十分になる恐れがある。
しかし、第五乃至第六仮設工程により、硝化槽３の内部における上記下流側の最も下流付近から上記上流側の最も上流付近へ、硝化された第一被処理液（第二被処理液）を循環させるため、硝化槽３の内部における第一被処理液の滞留時間を実質的に長くすることができる。従って、「補修時」の処理施設１′は、「通常運転時」の処理施設１と同様に、硝化槽３で十分な生物処理を行うことができる。 As described above, in the treatment facility 1 during "normal operation", the denitrification and nitrification treatments were performed in each of the two water tanks, the first denitrification tank 2 and the nitrification tank 3, respectively, but the treatment during "repair" At facility 1', denitrification and nitrification are performed in the nitrification tank 3, that is, one water tank. Therefore, compared with the residence time (reaction time) of the first liquid to be treated required for the denitrification and nitrification treatments performed in the two water tanks of the first denitrification tank 2 and the nitrification tank 3, the nitrification tank 3 is used for denitrification. The residence time when performing nitrogen and nitrification treatments is shortened, and there is a risk that the denitrification and nitrification treatments will be insufficient at the treatment facility 1'at the time of "repair".
However, by the fifth to sixth temporary steps, the nitrified first treated liquid (second treated liquid) is applied from the most downstream side on the downstream side to the most upstream side on the upstream side inside the nitrification tank 3. Since it is circulated, the residence time of the first liquid to be treated inside the nitrification tank 3 can be substantially lengthened. Therefore, the treatment facility 1'during "repair" can perform sufficient biological treatment in the nitrification tank 3 as in the treatment facility 1 during "normal operation".

それに加えて、第一工程は、硝化槽３の内部における上記下流側に、「通常運転時」の処理施設１の硝化槽３で使用する散気装置３ｂよりも高効率な散気装置２４を配置して、当該下流で第一被処理液を曝気して効果的に硝化する第七仮設工程を備える。
第七仮設工程では、「通常運転時」の処理施設１で硝化槽３がもともと備えている散気装置３ｂの散気管を交換することで、高効率な散気装置２４とすることができる。例えば、散気装置３ｂの散気管における孔径と孔の数よりも、孔径を大きくし且つ孔の数を多くした散気管に交換すればよい。高効率な散気装置２４は、空気溶解効率が１２％以上であることが望ましい。
なお、上述したように、図２の硝化槽３の内部において上記上流側に配置した散気装置３ｂは、取り外す必要はなく、動作を停止させるだけでよい。第一脱窒素層２の補修が終了した後、仮設した第一仮設配管２１等を取り外し、「補修時」の処理施設１′から「通常運転時」の処理施設１へ戻して再び運転する際、散気装置３ｂを使用するからである。 In addition, in the first step, an aeration device 24, which is more efficient than the aeration device 3b used in the nitrification tank 3 of the processing facility 1 during "normal operation", is installed on the downstream side inside the nitrification tank 3. It is provided with a seventh temporary step of arranging and aerating the first liquid to be treated downstream to effectively nitrify it.
In the seventh temporary step, the highly efficient air diffuser 24 can be obtained by replacing the air diffuser pipe of the air diffuser 3b originally provided in the nitrification tank 3 in the processing facility 1 during "normal operation". For example, it may be replaced with an air diffuser having a larger hole diameter and a larger number of holes than the pore diameter and the number of holes in the air diffuser 3b. It is desirable that the highly efficient air diffuser 24 has an air dissolution efficiency of 12% or more.
As described above, it is not necessary to remove the air diffuser 3b arranged on the upstream side inside the nitrification tank 3 of FIG. 2, and it is only necessary to stop the operation. After the repair of the first denitrification layer 2 is completed, when the temporarily installed first temporary pipe 21 and the like are removed and returned from the processing facility 1'during "repair" to the processing facility 1 during "normal operation" and operated again. This is because the air diffuser 3b is used.

次に、第二工程が備える仮設工程について説明する。
第二工程は、硝化槽３の内部において上記下流側の最も下流付近の第一被処理液の液中へ水中ポンプ２６を逆さまに配置し、且つ、水中ポンプ２６の吸込口２６ａを「通常運転時」の処理施設１における硝化槽３の液位Ｌａよりも低い液位Ｌｂに配置する第八仮設工程と、水中ポンプ２６と第一沈殿槽４とを接続する供給経路２５である水中ポンプ接続配管に、上記加水のための供給路（配管）２０を形成する第九仮設工程とを備える。
水中ポンプ２６を「逆さま」に配置とは、水中ポンプ２６を製造したメーカーが想定する水中ポンプ２６の使用時の姿勢（想定姿勢）と異なり、当該想定姿勢を上下逆転した姿勢に配置することを意味する。水中ポンプ２６の使用時の想定姿勢は、一般的に、鉛直方向で見て、上方にモーターが配置され且つ下方に吸込口が配置される姿勢である。 Next, the temporary process provided in the second process will be described.
In the second step, the submersible pump 26 is arranged upside down in the liquid of the first liquid to be treated near the most downstream side in the inside of the nitrification tank 3, and the suction port 26a of the submersible pump 26 is "normally operated". Submersible pump connection, which is a supply path 25 connecting the submersible pump 26 and the first settling tank 4, and the eighth temporary step of arranging the liquid level Lb lower than the liquid level La of the nitrification tank 3 in the treatment facility 1 of "Time". The pipe is provided with a ninth temporary step of forming the supply path (pipe) 20 for water addition.
Placing the submersible pump 26 "upside down" means that the submersible pump 26 is placed in an upside-down posture, unlike the posture (assumed posture) when the submersible pump 26 is used, which is assumed by the manufacturer of the submersible pump 26. means. The assumed posture when the submersible pump 26 is used is generally a posture in which the motor is arranged above and the suction port is arranged below when viewed in the vertical direction.

水中ポンプ２６を「逆さま」に配置して固定するには、例えば、図５に示すように、水中ポンプ２６の吸込口２６ａの互いに向かい合う２つの端部に１本のワイヤー２６ｃの両端をそれぞれ固定し、硝化槽３の上方且つ水平に配置した支柱２６ｂにワイヤー２６ｃの中央部を引掛けて吊るすとよい。
水中ポンプ２６には、水中ポンプ２６に内蔵されたモーターを駆動する電気ケーブル２６ｄと、当該モーターが駆動されることで、吸込口２６ａから吸い込んだ第一被処理液を第二被処理液として第一沈殿槽４へ移送するための上記供給経路２５である水中ポンプ接続配管が接続される。
そして、図５に示すように、水中ポンプ２６の吸込口２６ａを、「通常運転時」の処理施設１における硝化槽３の液位Ｌａ（図中破線）よりも低い液位Ｌｂ（図中実線）に配置する。液位Ｌｂは、液位Ｌａよりも、例えば、鉛直方向で２００ｍｍ程度低い。このため、水中ポンプ２６の全体が、硝化槽３に貯留された第一被処理液の液中に浸漬される。 To arrange and fix the submersible pump 26 "upside down", for example, as shown in FIG. 5, both ends of one wire 26c are fixed to the two opposite ends of the suction port 26a of the submersible pump 26. Then, the central portion of the wire 26c may be hooked and hung on the support column 26b arranged above and horizontally in the nitrification tank 3.
The submersible pump 26 includes an electric cable 26d for driving a motor built in the submersible pump 26 and a first liquid to be treated as a second liquid to be treated, which is sucked from the suction port 26a by driving the motor. (I) A submersible pump connection pipe, which is the supply path 25 for transferring to the settling tank 4, is connected.
Then, as shown in FIG. 5, the suction port 26a of the submersible pump 26 has a liquid level Lb (solid line in the figure) lower than the liquid level La (broken line in the figure) of the nitrification tank 3 in the treatment facility 1 during “normal operation”. ). The liquid level Lb is, for example, about 200 mm lower than the liquid level La in the vertical direction. Therefore, the entire submersible pump 26 is immersed in the liquid to be treated first stored in the nitrification tank 3.

仮に、水中ポンプ２６を想定姿勢で長時間使用した場合、水中ポンプ２６のモーターが熱を持ち、故障する恐れがあるが、第八仮設工程により、水中ポンプ２６を「逆さま」に配置して第一被処理液に浸漬することで、当該モーターを第一被処理液の液中で冷却することができ、結果として水中ポンプ２６の故障を回避できる。 If the submersible pump 26 is used for a long time in the assumed posture, the motor of the submersible pump 26 may get hot and break down. (1) By immersing in the liquid to be treated, the motor can be cooled in the liquid of the first liquid to be treated, and as a result, the failure of the submersible pump 26 can be avoided.

なお、液位Ｌａは、硝化槽３に備えられた排出管３ｅの開口の高さにあり、仮に硝化槽３に貯留された第一被処理液の液面が液位Ｌａより少々高くなった場合、第一被処理液が越流して排出管３ｅの開口に流れ込み、第二被処理液として第一沈殿槽４に供給される。
しかし、硝化槽３の液位Ｌａよりも低い液位Ｌｂに水中ポンプ２６の吸込口２６ａを配置して水中ポンプ２６を動作すると、硝化槽３の液位は液位Ｌｂに維持されるので、排出管３ｅを介して第二被処理液が第一沈殿槽４に供給されることはない。 The liquid level La is at the height of the opening of the discharge pipe 3e provided in the nitrification tank 3, and the liquid level of the first liquid to be treated temporarily stored in the nitrification tank 3 is slightly higher than the liquid level La. In this case, the first liquid to be treated overflows and flows into the opening of the discharge pipe 3e, and is supplied to the first settling tank 4 as the second liquid to be treated.
However, when the suction port 26a of the submersible pump 26 is arranged at the liquid level Lb lower than the liquid level La of the nitrification tank 3 and the submersible pump 26 is operated, the liquid level of the nitrification tank 3 is maintained at the liquid level Lb. The second liquid to be treated is not supplied to the first settling tank 4 via the discharge pipe 3e.

また、仮に硝化槽３に貯留された第一被処理液の液面を液位Ｌｂに下げず、液位Ｌａのまま維持した場合には、第一脱窒素槽２を空水槽にして補修を行う際、硝化槽３に貯留された第一被処理液が第一脱窒素槽２の備える排出管２ｅを逆流して第一脱窒素槽２に流れ込み、第一脱窒素槽２の補修を妨げる恐れがあるが、第八仮設工程により、硝化槽３の液位を液位Ｌｂに下げることで、当該逆流を防止することができる。 If the liquid level of the first liquid to be treated stored in the nitrification tank 3 is not lowered to the liquid level Lb and is maintained at the liquid level La, the first denitrification tank 2 is used as an empty water tank for repair. At that time, the first liquid to be treated stored in the nitrification tank 3 flows back into the discharge pipe 2e provided in the first denitrification tank 2 and flows into the first denitrification tank 2, which hinders the repair of the first denitrification tank 2. Although there is a risk, the backflow can be prevented by lowering the liquid level of the nitrification tank 3 to the liquid level Lb by the eighth temporary step.

次に、第三工程が備える仮設工程について説明する。
第三工程は、返送配管１２に返送配管仮設バルブ１２Ｖを配置する第三仮設工程と、返送配管１２における返送配管仮設バルブ１２Ｖ及び第一ポンプ１４の間と硝化槽３とを接続し、且つ、第二仮設配管バルブ２２Ｖを備えた第二仮設配管２２を配置する第四仮設工程とを備える。
返送配管仮設バルブ１２Ｖが開弁されると、第一沈殿槽４の第一沈殿液が、返送配管１２を介して、第一脱窒素槽２に供給される。一方、返送配管仮設バルブ１２Ｖが閉弁されると、第一沈殿液の第一脱窒素槽２への供給が停止される。
第二仮設配管バルブ２２Ｖが開弁されると、第一沈殿槽４の第一沈殿液が、返送配管１２から第二仮設配管２２を介して、硝化槽３の内部における上記上流側の最も上流付近に供給される。一方、第二仮設配管バルブ２２Ｖが閉弁されると、当該上流付近への第一沈殿液の供給が停止される。 Next, the temporary process provided in the third process will be described.
In the third step, the third temporary step of arranging the return pipe temporary valve 12V in the return pipe 12 and the vitrification tank 3 are connected between the return pipe temporary valve 12V and the first pump 14 in the return pipe 12. It includes a fourth temporary step of arranging the second temporary pipe 22 provided with the second temporary pipe valve 22V.
When the return pipe temporary valve 12V is opened, the first settling liquid of the first settling tank 4 is supplied to the first denitrification tank 2 via the return pipe 12. On the other hand, when the temporary return pipe valve 12V is closed, the supply of the first precipitation liquid to the first denitrification tank 2 is stopped.
When the second temporary piping valve 22V is opened, the first settling liquid of the first settling tank 4 passes from the return pipe 12 via the second temporary pipe 22 to the most upstream side of the inside of the nitrification tank 3 on the upstream side. Supplied in the vicinity. On the other hand, when the second temporary piping valve 22V is closed, the supply of the first settling liquid to the vicinity of the upstream is stopped.

「補修時」の処理施設１′において、第一工程、第二工程、及び、第三工程が備える各仮設工程で設置された各バルブは、それぞれ次のように開弁または閉弁のいずれか一方に択一的に設定される。
すなわち、供給管仮設バルブ１０Ｖを閉弁して第一脱窒素槽２への第一被処理液の供給を停止し、第一仮設配管バルブ２１Ｖを開弁して第一被処理液を硝化槽３へ供給し、返送配管仮設バルブ１２Ｖを閉弁して第一脱窒素槽２への第一沈殿液の返送を停止し、第二仮設配管バルブ２２Ｖを開弁して硝化槽３へ第一沈殿液を返送する。
また、循環配管仮設バルブ１１Ｖを閉弁して第一脱窒素槽２への第二被処理液の循環を停止し、第三仮設配管バルブ２３Ｖを開弁して第二被処理液を硝化槽３の内部における上流へ循環させる。 In the processing facility 1'at the time of "repair", each valve installed in each temporary process provided in the first process, the second process, and the third process is either opened or closed as follows. It is set alternately on one side.
That is, the temporary supply pipe valve 10V is closed to stop the supply of the first liquid to be treated to the first denitrification tank 2, and the first temporary piping valve 21V is opened to nitrify the first liquid to be treated. Supply to No. 3, close the temporary return pipe valve 12V to stop the return of the first sediment to the first denitrification tank 2, open the second temporary pipe valve 22V, and first to the nitrification tank 3. Return the sediment.
Further, the temporary circulation pipe valve 11V is closed to stop the circulation of the second liquid to be treated to the first denitrification tank 2, and the third temporary pipe valve 23V is opened to nitrify the second liquid to be treated. Circulate upstream inside 3.

本発明の補修方法が適用される処理施設は、標準脱窒素処理方式の処理施設に限られない。本発明の補修方法を適用することにより、処理施設の運転を継続しつつ、生物処理槽の中で最も上流に位置する脱窒素槽の補修を安価に実施して、処理施設の延命化を図ることができる。 The treatment facility to which the repair method of the present invention is applied is not limited to the treatment facility of the standard denitrification treatment method. By applying the repair method of the present invention, while continuing the operation of the treatment facility, the denitrification tank located at the most upstream of the biological treatment tanks can be repaired at low cost to prolong the life of the treatment facility. be able to.

１通常運転時の処理施設（し尿処理施設）
１′ 補修時の処理施設（し尿処理施設）
２第一脱窒素槽
２ａ仕切壁
２ｅ排出管
３硝化槽
３ａ仕切壁
３ｂ散気装置
３ｅ排出管
４第一沈殿槽
４ｃ整流筒
４ｅ排出管
５第二脱窒素槽
５ｅ排出管
６再曝気槽
６ｅ排出管
７第二沈殿槽
７ｃ整流筒
７ｅ排出管
１０供給管
１０Ｖ供給管仮設バルブ
１１循環配管
１１Ｖ循環配管仮設バルブ
１２返送配管
１２Ｖ返送配管仮設バルブ
１３第二返送配管
１４第一ポンプ
１５第二ポンプ
１６第三ポンプ
２０水の供給路（配管）
２１第一仮設配管
２１Ｖ第一仮設配管バルブ
２２第二仮設配管
２２Ｖ第二仮設配管バルブ
２３第三仮設配管
２３Ｖ第三仮設配管バルブ
２４高効率散気装置
２５供給経路（水中ポンプ接続配管）
２６水中ポンプ
２６ａ吸込口
２６ｂ支柱
２６ｃワイヤー
２６ｄ電気ケーブル
Ｌａ通常運転時の硝化槽内の液位
Ｌｂ補修時の硝化槽内の液位 1 Treatment facility during normal operation (sewage treatment facility)
1'Repair treatment facility (sewage treatment facility)
2 1st denitrification tank 2a partition wall 2e discharge pipe 3 nitrification tank 3a partition wall 3b air diffuser 3e discharge pipe 4 1st settling tank 4c rectifying pipe 4e discharge pipe 5 2nd denitrification tank 5e discharge pipe 6 re-exposure tank 6e Discharge pipe 7 Second settling tank 7c Straightening pipe 7e Discharge pipe 10 Supply pipe 10V Supply pipe Temporary valve 11 Circulation pipe 11V Circulation pipe Temporary valve 12 Return pipe 12V Return pipe Temporary valve 13 Second return pipe 14 First pump 15 Second pump 16 Third pump 20 Water supply path (piping)
21 1st temporary piping 21V 1st temporary piping valve 22 2nd temporary piping 22V 2nd temporary piping valve 23 3rd temporary piping 23V 3rd temporary piping valve 24 High efficiency air diffuser 25 Supply path (submersible pump connection piping)
26 Submersible pump 26a Suction port 26b Strut 26c Wire 26d Electric cable La Liquid level in the nitrification tank during normal operation Lb Liquid level in the nitrification tank during repair

Claims

Each is provided with at least a denitrification tank, a nitrification tank, and a settling tank formed of separate water tanks, and a first treatment liquid containing urine as a main component is supplied to the denitrification tank to denitrify and denitrify. A urine treatment facility in which the first liquid to be treated is supplied from the denitrification tank to the nitrification tank to be nitrified, and the nitrified first liquid to be treated is supplied from the nitrification tank to the settling tank as a second liquid to be treated. In
The supply of the first liquid to be treated to the denitrification tank is stopped, the first liquid to be treated is supplied to the nitrification tank without passing through the denitrification tank, and the first treatment is performed in the nitrification tank. The first step of denitrifying and nitrifying the liquid,
When the second liquid to be treated is supplied from the nitrification tank to the settling tank, a second step of adding water in the supply path of the second liquid to be treated and
A third step of returning the precipitate liquid gravity-precipitated from the second liquid to be treated in the sedimentation tank to the nitrification tank.
A method for repairing a denitrification tank in a urine treatment facility, which comprises a fourth step of repairing the denitrification tank while carrying out the first to third steps.

The urine treatment facility includes a supply pipe for supplying the first liquid to be treated to the denitrification tank, and a return pipe for returning the precipitate liquid from the settling tank to the denitrification tank by a first pump.
The first step is
The first temporary step of connecting the supply pipe and the nitrification tank and arranging the first temporary pipe provided with the first temporary pipe valve.
The supply pipe includes a first temporary pipe and a second temporary step of arranging a supply pipe temporary valve between the connection point of the supply pipe and the denitrification tank.
The third step is
The third temporary process of arranging the return pipe temporary valve on the return pipe, and
It is provided with a fourth temporary step of connecting the nitrification tank between the return pipe temporary valve and the first pump in the return pipe and arranging the second temporary pipe provided with the second temporary pipe valve.
The temporary supply pipe valve is closed to stop the supply of the first liquid to be treated to the denitrification tank, the first temporary pipe valve is opened, and the first liquid to be treated is sent to the nitrification tank. A request for supplying, closing the temporary return pipe valve to stop the return of the sediment to the denitrification tank, opening the second temporary pipe valve, and returning the precipitate to the nitrification tank. Item 2. The method for repairing a denitrification tank in a urine treatment facility according to Item 1.

The urine treatment facility denitrifies the first liquid to be treated upstream in the nitrification tank and nitrifies the first liquid to be treated downstream in the inside.
A circulation pipe for circulating the second liquid to be treated from the downstream inside the inside to the denitrification tank by the second pump is provided.
The first step is
The fifth temporary step of arranging the circulation pipe temporary valve in the circulation pipe, and
A sixth that connects between the circulation pipe temporary valve and the second pump in the circulation pipe and the upstream in the inside of the nitrification tank, and arranges the third temporary pipe provided with the third temporary pipe valve. With a temporary process
The temporary circulation pipe valve is closed to stop the circulation of the second liquid to be treated to the denitrification tank, and the third temporary pipe valve is opened to supply the second liquid to be treated to the nitrification tank. The method for repairing a denitrification tank of a urine treatment facility according to claim 2, wherein the liquid is circulated upstream in the inside.

In the first step, an air diffuser having a higher efficiency than the air diffuser used during normal operation of the urine treatment facility is arranged downstream of the inside of the nitrification tank to nitrify the first liquid to be treated. With the 7th temporary process
The second step is
The submersible pump is arranged upside down in the inside of the nitrification tank and into the liquid of the first liquid to be treated, and the suction port of the submersible pump is a liquid lower than the liquid level of the nitrification tank during the normal operation. The eighth temporary process to be placed in the position and
The submersible pump connection pipe, which is the supply path connecting the submersible pump and the settling tank, is provided with a ninth temporary step of forming a supply path for water addition.
The urine according to claim 3, wherein the submersible pump is operated to convey the liquid to be treated from the suction port to the settling tank via the submersible pump connecting pipe, and water is supplied from the supply path. How to repair the denitrification tank of the treatment facility.

The denitrification tank repair method for a urine treatment facility according to any one of claims 1 to 4, wherein the urine treatment facility is a standard denitrification treatment facility.