JP6334244B2 - Water treatment process control system - Google Patents

Water treatment process control system Download PDF

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JP6334244B2
JP6334244B2 JP2014092210A JP2014092210A JP6334244B2 JP 6334244 B2 JP6334244 B2 JP 6334244B2 JP 2014092210 A JP2014092210 A JP 2014092210A JP 2014092210 A JP2014092210 A JP 2014092210A JP 6334244 B2 JP6334244 B2 JP 6334244B2
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simultaneous nitrification
denitrification
aeration
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佳記 西田
佳記 西田
一郎 山野井
一郎 山野井
剛 武本
剛 武本
隆広 舘
隆広 舘
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Hitachi Ltd
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    • Y—GENERAL 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
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Description

本発明は、活性汚泥を用いた水処理プロセスの制御システムに関する。
The present invention relates to a control system for a water treatment process using activated sludge.

下水処理場をはじめとする水処理装置では、環境汚濁物質を除去するための様々な水処理プロセスが導入されている。例えば、有機物を除去対象としている標準活性汚泥法では、生物反応槽の全てが曝気により空気が供給され、好気槽のみの構成となっている。好気槽では、好気性従属栄養菌が有機物を酸化し、下水中の有機物は除去される。   In water treatment apparatuses such as sewage treatment plants, various water treatment processes for removing environmental pollutants are introduced. For example, in the standard activated sludge method in which organic substances are to be removed, all of the biological reaction tank is supplied with air by aeration, and has only an aerobic tank. In the aerobic tank, the aerobic heterotrophic oxidizer oxidizes the organic matter and the organic matter in the sewage is removed.

一方、閉鎖性水域の環境保全のため、有機物除去に加えて窒素除去の必要性が高まってきている。一般的な窒素除去は、好気状態での硝化と、無酸素状態での脱窒から実現される。硝化は好気状態において、硝化菌が酸素を用い、下水中のアンモニア性窒素（ＮＨ４−Ｎ）を硝酸性窒素（ＮＯ３−Ｎ）へ酸化する反応である。脱窒は無酸素状態において、脱窒菌が有機物を用い、ＮＯ３−ＮをＮ２ガスへ還元する反応である。脱窒により生成するＮ２ガスは大気中へ放出されるため、液相中から窒素は除去される。   On the other hand, in order to preserve the environment of closed water areas, the need for nitrogen removal in addition to organic matter removal is increasing. General nitrogen removal is realized by nitrification in an aerobic state and denitrification in an oxygen-free state. Nitrification is a reaction in which nitrifying bacteria use oxygen to oxidize ammonia nitrogen (NH4-N) in sewage to nitrate nitrogen (NO3-N) in an aerobic state. Denitrification is a reaction in which denitrifying bacteria use organic matter to reduce NO3-N to N2 gas in the absence of oxygen. Since N2 gas generated by denitrification is released into the atmosphere, nitrogen is removed from the liquid phase.

そのため、一般的な下水処理での窒素除去では、好気状態と無酸素状態が必要となり、好気槽と無酸素槽を分離し、設置している。一方、同一反応槽内で硝化と脱窒を同時に進行させる同時硝化脱窒と呼ばれる方法も提案されている。同時硝化脱窒の実現には、曝気風量を制限し、好気状態と無酸素状態を併存しなければならない。そのため、曝気風量が過大であると、溶存酸素（ＤＯ）濃度が高くなり、硝化は進行するものの、脱窒性能は低下する。一方、曝気風量が過小であると、硝化性能が低下する。そのため、同時硝化脱窒による窒素除去では、硝化と脱窒の進行の両方を評価し、適切に曝気風量を制御する必要がある。   Therefore, nitrogen removal in general sewage treatment requires an aerobic state and an oxygen-free state, and the aerobic tank and the oxygen-free tank are separated and installed. On the other hand, a method called simultaneous nitrification / denitrification in which nitrification and denitrification proceed simultaneously in the same reaction tank has also been proposed. In order to realize simultaneous nitrification and denitrification, the amount of aerated air must be limited, and aerobic and anoxic conditions must coexist. Therefore, if the amount of aeration air is excessive, the dissolved oxygen (DO) concentration becomes high and nitrification proceeds, but the denitrification performance decreases. On the other hand, if the aeration air volume is too small, the nitrification performance decreases. Therefore, in nitrogen removal by simultaneous nitrification and denitrification, it is necessary to evaluate both the progress of nitrification and denitrification and to control the amount of aeration air appropriately.

硝化はｐＨが減少し、脱窒はｐＨが増加する反応であるため、硝化および脱窒の進行状況の評価指標としてｐＨを用いた水処理プロセスの運転制御方法が提案されている。（特許文献１）では、硝化によるｐＨの減少、脱窒によるｐＨの増加における変化速度および変化幅、ならびに変化速度が０になる時点の出現の有無に基づく運転制御方法が提案されている。また、（特許文献２）では、硝化に伴うｐＨの減少に基づき、同時硝化脱窒の進行の程度を判断し、曝気風量を制御している。例えば、計測値が設定した基準値よりも低ければ、硝化が優勢していると判断し、曝気風量を下げる。一方、計測値が基準値よりも高ければ、硝化が不足していると判断し、曝気風量を上げる。
Since nitrification is a reaction in which pH decreases and denitrification increases in pH, an operation control method of a water treatment process using pH as an evaluation index for the progress of nitrification and denitrification has been proposed. (Patent Document 1) proposes an operation control method based on a decrease in pH due to nitrification, a change rate and a change width in an increase in pH due to denitrification, and the presence or absence of a point at which the change rate becomes zero. Moreover, in (patent document 2), based on the reduction | decrease of pH accompanying nitrification, the progress of simultaneous nitrification denitrification is judged and the amount of aeration air is controlled. For example, if the measured value is lower than the set reference value, it is determined that nitrification is dominant and the aeration air volume is reduced. On the other hand, if the measured value is higher than the reference value, it is determined that nitrification is insufficient and the aeration air volume is increased.

特開平08-323394号公報Japanese Unexamined Patent Publication No. 08-323394 特許第４３８１４７３号公報Japanese Patent No. 4381473

先行技術において、例えば（特許文献１）では、ｐＨの低下に基づき硝化の進行を、ｐＨの上昇に基づき脱窒の進行を判断しているが、硝化と脱窒とが同時に進行する同時硝化脱窒の判断には利用できない。また、（特許文献２）では、硝化に伴うｐＨの減少に基づき、好気槽でのｐＨから同時硝化脱窒の進行を判断していた。しかし、同時硝化脱窒が進行しやすい曝気初期には有機物が豊富に存在しており、例えば有機酸の酸化などによりｐＨが上昇した場合などは、（特許文献２）の制御では同時硝化脱窒の進行の判断は困難となっている。
In the prior art, for example, (Patent Document 1) judges the progress of nitrification based on a decrease in pH and the progress of denitrification based on an increase in pH, but simultaneous nitrification and denitrification in which nitrification and denitrification proceed simultaneously. It cannot be used for judgment of Nitro. Moreover, in (patent document 2), based on the reduction | decrease of pH accompanying nitrification, progress of simultaneous nitrification denitrification was judged from pH in an aerobic tank. However, organic matter is abundant in the initial stage of aeration in which simultaneous nitrification and denitrification is likely to proceed. For example, when the pH rises due to oxidation of an organic acid or the like, the control of (Patent Document 2) performs simultaneous nitrification and denitrification. Judgment of the progress of is difficult.

従来の課題を達成するために、本発明は水処理プロセス制御システムにおいて、硝化と脱窒を同時に進行させる同時硝化脱窒領域を有する好気槽と、前記同時硝化脱窒領域の下流に設けられた硝化を進行させる硝化領域と、前記同時硝化脱窒領域内を曝気する第１曝気手段と、前記同時硝化脱窒領域への流入水のｐＨを計測する第１ｐＨ計測手段と、前記同時硝化脱窒領域のｐＨを計測する第２ｐＨ計測手段とを備え、前記第１ｐＨ計測手段の計測値に対する前記第２ｐＨ計測手段の計測値のｐＨの増加量を前記同時硝化脱窒領域のｐＨ増加量とし、前記同時硝化脱窒領域のｐＨ増加量基準値を設定し、前記同時硝化脱窒領域のｐＨ増加量が、前記同時硝化脱窒領域のｐＨ増加量基準値以上になるように、前記第１曝気手段による曝気風量を制御する第１曝気風量制御手段を有することを特徴とする。   In order to achieve the conventional problems, the present invention provides an aerobic tank having a simultaneous nitrification / denitrification region in which nitrification and denitrification proceed simultaneously, and a downstream of the simultaneous nitrification / denitrification region in a water treatment process control system. A first nitrification area for advancing nitrification, a first aeration means for aeration in the simultaneous nitrification denitrification area, a first pH measurement means for measuring the pH of the inflow water to the simultaneous nitrification denitrification area, and the simultaneous nitrification denitrification A second pH measuring means for measuring the pH of the nitrogenous region, and the amount of increase in pH of the measured value of the second pH measuring unit relative to the value measured by the first pH measuring unit is the amount of increase in pH of the simultaneous nitrification denitrifying region, The pH increase amount reference value of the simultaneous nitrification denitrification region is set, and the first aeration is performed such that the pH increase amount of the simultaneous nitrification denitrification region is equal to or greater than the pH increase amount reference value of the simultaneous nitrification denitrification region. Aeration air volume by means And having a first aeration amount control means Gosuru.

更に、本発明は水処理プロセス制御システムにおいて、前記ｐＨ増加量基準値を０以上の値に設定したことを特徴とするものである。   Furthermore, the present invention is characterized in that, in the water treatment process control system, the pH increase reference value is set to a value of 0 or more.

更に、本発明は水処理プロセス制御システムにおいて、前記第１曝気手段による曝気風量の最小値を設定し、前記第１曝気手段による曝気風量を、前記第１曝気手段による曝気風量の最小値以上とすることを特徴とする。   Further, in the water treatment process control system according to the present invention, a minimum value of the aeration air volume by the first aeration means is set, and the aeration air volume by the first aeration means is equal to or more than the minimum value of the aeration air volume by the first aeration means. It is characterized by doing.

更に、本発明は水処理プロセス制御システムにおいて、前記同時硝化脱窒領域のｐＨ増加量が、前記同時硝化脱窒領域のｐＨ増加量基準値を下回った場合、前記第１曝気手段による曝気風量を低減させることを特徴とする。   Further, in the water treatment process control system according to the present invention, when the pH increase amount of the simultaneous nitrification denitrification region is lower than a reference value of the pH increase amount of the simultaneous nitrification denitrification region, the aeration air amount by the first aeration means is reduced. It is characterized by reducing.

更に、本発明は水処理プロセス制御システムにおいて、前記同時硝化脱窒領域内の前記第２ｐＨ計測手段の上流に、前記同時硝化脱窒領域におけるｐＨを計測する第３ｐＨ計測手段を備え、前記第２ｐＨ計測手段の計測値が前記第３ｐＨ計測手段の計測値を下回った場合、前記第１曝気手段の風量を低減させることを特徴とする。   Furthermore, in the water treatment process control system, the present invention further comprises third pH measuring means for measuring the pH in the simultaneous nitrification denitrification region upstream of the second pH measurement means in the simultaneous nitrification denitrification region, When the measurement value of the measurement means falls below the measurement value of the third pH measurement means, the air volume of the first aeration means is reduced.

更に、本発明は水処理プロセス制御システムにおいて、前記第２ｐＨ計測手段の計測値が前記第３ｐＨ計測手段の計測値を上回った場合、前記第１曝気手段の風量を増加させることを特徴とする。   Furthermore, the present invention is characterized in that, in the water treatment process control system, when the measurement value of the second pH measurement means exceeds the measurement value of the third pH measurement means, the air volume of the first aeration means is increased.

更に、本発明は水処理プロセス制御システムにおいて、前記同時硝化脱窒領域の上流に、前記同時硝化脱窒領域への流入有機物負荷を計測する有機物負荷計測手段を備え、前記有機物負荷計測手段の計測値に対して前記同時硝化脱窒領域のｐＨ増加量基準値を設定することを特徴とする。
Furthermore, the present invention is a water treatment process control system, further comprising an organic substance load measuring means for measuring an inflow load of organic substances into the simultaneous nitrification / denitrification area upstream of the simultaneous nitrification / denitrification area, and measuring the organic substance load measurement means A reference value for increasing the pH of the simultaneous nitrification denitrification region is set for the value.

本発明によれば、同時硝化脱窒を行う水処理プロセス制御システムにおいて、曝気風量の制御により、好気状態での硝化と脱窒を同時に進行することを実現できる。   ADVANTAGE OF THE INVENTION According to this invention, in the water treatment process control system which performs simultaneous nitrification denitrification, it can implement | achieve nitrification and denitrification in an aerobic state simultaneously by controlling aeration air volume.

実施例１に係る水処理装置の構成を示す構成図である。It is a block diagram which shows the structure of the water treatment apparatus which concerns on Example 1. FIG. 好気状態における有機物（全有機炭素）と窒素の挙動を示す実験結果である。It is an experimental result which shows the behavior of the organic substance (total organic carbon) and nitrogen in an aerobic state. 好気状態におけるＤＯとｐＨの挙動を示す実験結果である。It is an experimental result which shows the behavior of DO and pH in an aerobic state. 実施例１における第１ブロワ５の曝気風量の制御フロー図である。It is a control flow figure of the aeration air volume of the 1st blower in Example 1. FIG. 下水中の有機物濃度と同時硝化脱窒領域のｐＨ増加量の関係を示す実験結果である。It is an experimental result which shows the relationship between the organic matter density | concentration in sewage, and the pH increase amount of simultaneous nitrification denitrification area | region. 実施例２に係る水処理装置の構成を示す構成図である。It is a block diagram which shows the structure of the water treatment apparatus which concerns on Example 2. FIG. 実施例２における第１ブロワ５の曝気風量の制御フロー図である。It is a control flow figure of the aeration air volume of the 1st blower in Example 2.

以下、本発明の実施例を図面を用いて説明する。 Embodiments of the present invention will be described below with reference to the drawings.

図１は、本発明の実施例１に係る水処理装置の構成を示す構成図である。この水処理装置は、標準活性汚泥法の流れにおいて、活性汚泥を利用して有機物と窒素を除去する。
FIG. 1 is a configuration diagram illustrating a configuration of a water treatment apparatus according to Embodiment 1 of the present invention. This water treatment device removes organic substances and nitrogen using activated sludge in the flow of the standard activated sludge method.

（水処理装置の構成）
図１に示すように、水処理装置は、主な構成要素として、同時硝化脱窒領域である同時硝化脱窒槽１と、硝化領域である好気槽２と、最終沈殿池３とを有している。これらの構成要素の機能について概要を説明すると、以下のとおりである。 (Configuration of water treatment equipment)
As shown in FIG. 1, the water treatment apparatus has a simultaneous nitrification / denitrification tank 1 that is a simultaneous nitrification / denitrification area, an aerobic tank 2 that is a nitrification area, and a final sedimentation tank 3 as main components. ing. The outline of the functions of these components will be described as follows.

（同時硝化脱窒槽）
同時硝化脱窒槽１は下水１００と、返送汚泥１０２とが流入し、活性汚泥中の硝化菌により、ＮＨ４−ＮをＮＯ３−Ｎへ酸化する硝化と、活性汚泥中の脱窒菌により、ＮＯ３−ＮをＮ２ガスへと還元する脱窒とが同時に進行する同時硝化脱窒が行われ、窒素を系外へ除去する槽である。また、好気性従属栄養菌による有機物酸化が行われる。 (Simultaneous nitrification denitrification tank)
In the simultaneous nitrification denitrification tank 1, sewage 100 and return sludge 102 flow in, and NO3-N is oxidized by nitrification in the activated sludge by nitrification to oxidize NH4-N to NO3-N and denitrification bacteria in the activated sludge. This is a tank in which simultaneous nitrification and denitrification in which denitrification to reduce N2 gas proceeds at the same time is performed and nitrogen is removed from the system. In addition, organic matter oxidation by aerobic heterotrophic bacteria is performed.

（好気槽）
好気槽２は、同時硝化脱窒槽１からの流出水中のＮＨ４−ＮをＮＯ３−Ｎへ硝化することを主な目的としている。また、好気性従属栄養菌による有機物酸化も行われる。 (Aerobic tank)
The aerobic tank 2 is mainly intended to nitrify NH4-N in the effluent from the simultaneous nitrification denitrification tank 1 to NO3-N. Organic matter oxidation by aerobic heterotrophic bacteria is also performed.

（最終沈殿池）
最終沈殿池３は、活性汚泥と上澄み液を沈降分離する設備である。沈降分離した上澄み液は、処理水１０１として系外に放流される。また、沈降分離した活性汚泥は返送汚泥１０２として同時硝化脱窒槽１へと返送され、再度一連の生物処理に利用される。

以下、本発明の水処理装置についてより詳細に説明する。
(Final sedimentation basin)
The final sedimentation basin 3 is a facility that separates activated sludge and supernatant liquid. The supernatant liquid that has settled and separated is discharged out of the system as treated water 101. In addition, the activated sludge that has settled and separated is returned to the simultaneous nitrification denitrification tank 1 as return sludge 102, and again used for a series of biological treatments.

Hereinafter, the water treatment apparatus of the present invention will be described in more detail.

図１に示すように、同時硝化脱窒槽１には下水１００と、最終沈殿池３からの返送汚泥１０２が流入する。同時硝化脱窒槽１には第１曝気手段である第１散気部４と第１ブロワ５とが設置されている。第１散気部４には第１ブロワ５により空気が供給される。同時硝化脱窒槽１の下流側には好気槽２が設置されており、同時硝化脱窒槽１からの流出水が流入する。好気槽２には第２散気部６と、第２散気部６に空気を供給する第２ブロワ７とが設置されている。好気槽２の下流側には最終沈殿池３が設置されており、流路８００と返送ポンプ８を通じて同時硝化脱窒槽１と連通している。

同時硝化脱窒槽１の上流には、第１ｐＨ計測手段である第１ｐＨ計９が設置され、第１ｐＨ計９により同時硝化脱窒槽１への流入水のｐＨが計測される。また、同時硝化脱窒槽１の上流には、有機物負荷計測手段である流量計１０と有機物濃度計１１とが設置され、流量計１０により同時硝化脱窒槽１への流入水量が計測され、有機物濃度計１１により同時硝化脱窒槽１への流入水の有機物濃度が計測される。流量計１０の計測値と有機物濃度計１１の計測値とから同時硝化脱窒槽１への流入有機物負荷が算出される。同時硝化脱窒槽１の下流部には、第２ｐＨ計測手段である第２ｐＨ計１２が設置され、第２ｐＨ計１２により同時硝化脱窒槽１内のｐＨが計測される。第１ｐＨ計９と、流量計１０と、有機物濃度計１１と、第２ｐＨ計１２とは、第１曝気風量制御手段１３と接続されている。また、第１曝気風量制御手段１３は、第１ブロワ５と接続されており、第１曝気風量制御手段１３により、第１ブロワ５の曝気風量は制御される。
As shown in FIG. 1, sewage 100 and return sludge 102 from the final sedimentation basin 3 flow into the simultaneous nitrification denitrification tank 1. The simultaneous nitrification denitrification tank 1 is provided with a first aeration unit 4 and a first blower 5 which are first aeration means. Air is supplied to the first air diffuser 4 by the first blower 5. An aerobic tank 2 is installed on the downstream side of the simultaneous nitrification / denitrification tank 1, and effluent water from the simultaneous nitrification / denitrification tank 1 flows in. The aerobic tank 2 is provided with a second air diffuser 6 and a second blower 7 for supplying air to the second air diffuser 6. A final sedimentation basin 3 is installed downstream of the aerobic tank 2 and communicates with the simultaneous nitrification / denitrification tank 1 through a flow path 800 and a return pump 8.

A first pH meter 9 as a first pH measuring means is installed upstream of the simultaneous nitrification denitrification tank 1, and the pH of the inflow water to the simultaneous nitrification denitrification tank 1 is measured by the first pH meter 9. Further, upstream of the simultaneous nitrification denitrification tank 1, a flow meter 10 and an organic substance concentration meter 11, which are organic substance load measuring means, are installed, and the amount of water flowing into the simultaneous nitrification denitrification tank 1 is measured by the flow meter 10, and the organic substance concentration A total of 11 measures the organic matter concentration of the inflow water to the simultaneous nitrification denitrification tank 1. The inflow organic matter load into the simultaneous nitrification denitrification tank 1 is calculated from the measurement value of the flow meter 10 and the measurement value of the organic matter concentration meter 11. A second pH meter 12 as a second pH measuring means is installed downstream of the simultaneous nitrification denitrification tank 1, and the pH in the simultaneous nitrification denitrification tank 1 is measured by the second pH meter 12. The first pH meter 9, the flow meter 10, the organic substance concentration meter 11, and the second pH meter 12 are connected to the first aeration air volume control means 13. The first aeration air volume control means 13 is connected to the first blower 5, and the aeration air volume of the first blower 5 is controlled by the first aeration air volume control means 13.

次に、本発明の実施例１に係る水処理装置における処理の流れを説明する。
Next, the process flow in the water treatment apparatus according to the first embodiment of the present invention will be described.

下水１００は返送汚泥１０２とともに同時硝化脱窒槽１に流入する。同時硝化脱窒槽１では、活性汚泥中の硝化菌によりＮＨ４−ＮがＮＯ３−Ｎへ酸化される硝化と、活性汚泥中の脱窒菌によりＮＯ３−ＮがＮ２ガスへと還元される脱窒とが同時に進行する同時硝化脱窒が行われ、系外へと窒素を除去する。また、同時硝化脱窒槽１では、好気性従属栄養菌により有機物が酸化される。好気槽２では、同時硝化脱窒槽１からの流出水中のＮＨ４−ＮをＮＯ３−Ｎへと硝化する。また、好気槽２では、好気性従属栄養菌により有機物も酸化される。最終沈殿池３では、好気槽２からの活性汚泥を沈降分離し、上澄み液を処理水１０１として系外に排出する。一方、最終沈殿池３において沈降分離された活性汚泥は、流路８００と返送ポンプ９により、返送汚泥１０２として同時硝化脱窒槽１へ返送する。

従来の標準活性汚泥法における第１ブロワ５の曝気風量制御は、例えば一定制御か、下水１００の流入水量に対する流量比一定制御である。しかしながら、同時硝化脱窒は、ＤＯなどの影響を強く受け、曝気風量が不適切であると、窒素除去性能は低下する。例えば、曝気風量が過大であると、硝化は進行するものの、ＤＯ濃度も高くなり、脱窒性能が低下する。一方、曝気風量が過小であると、硝化性能が低下する。
The sewage 100 flows into the simultaneous nitrification denitrification tank 1 together with the return sludge 102. In the simultaneous nitrification denitrification tank 1, there are nitrification in which NH4-N is oxidized to NO3-N by nitrifying bacteria in activated sludge and denitrification in which NO3-N is reduced to N2 gas by denitrifying bacteria in activated sludge. Simultaneous nitrification and denitrification, which proceeds at the same time, is performed to remove nitrogen out of the system. In the simultaneous nitrification denitrification tank 1, organic substances are oxidized by aerobic heterotrophic bacteria. In the aerobic tank 2, NH4-N in the effluent from the simultaneous nitrification denitrification tank 1 is nitrified to NO3-N. In the aerobic tank 2, organic substances are also oxidized by aerobic heterotrophic bacteria. In the final sedimentation basin 3, the activated sludge from the aerobic tank 2 is settled and separated, and the supernatant liquid is discharged out of the system as treated water 101. On the other hand, the activated sludge separated and separated in the final sedimentation basin 3 is returned to the simultaneous nitrification denitrification tank 1 as the return sludge 102 by the flow path 800 and the return pump 9.

The aeration air volume control of the first blower 5 in the conventional standard activated sludge method is, for example, constant control or constant flow ratio control with respect to the inflow water amount of the sewage 100. However, simultaneous nitrification denitrification is strongly influenced by DO and the like, and if the amount of aeration air is inappropriate, the nitrogen removal performance decreases. For example, if the aeration air volume is excessive, nitrification proceeds, but the DO concentration increases and the denitrification performance decreases. On the other hand, if the aeration air volume is too small, the nitrification performance decreases.

図２に、本願の発明者が回分実験により、好気状態における有機物（全有機炭素）と窒素の挙動を調べた結果を示す。   FIG. 2 shows the results obtained by examining the behavior of organic matter (total organic carbon) and nitrogen in an aerobic state by the batch experiment by the inventors of the present application.

全有機炭素の減少のうち、その大部分は曝気開始後２時間までに達成された。また、ＮＨ４−Ｎの減少量に対してＮＯ３−Ｎの生成量は低く、全窒素濃度は低下しており、曝気開始２時間は同時硝化脱窒が起こっていたと考えられる。曝気開始２時間以降は硝化が進行し、ＮＯ３−Ｎ濃度は上昇した。５時間目にはＮＨ４−Ｎ濃度は不検出となり、硝化が完了した。   Most of the reduction in total organic carbon was achieved by 2 hours after the start of aeration. In addition, the amount of NO3-N produced is lower than the amount of NH4-N reduced, the total nitrogen concentration is lowered, and it is considered that simultaneous nitrification and denitrification occurred for 2 hours from the start of aeration. Nitrification progressed after 2 hours from the start of aeration, and the NO3-N concentration increased. At 5 hours, the NH4-N concentration was not detected, and nitrification was completed.

図３にこの実験におけるＤＯやｐＨの挙動を示す。図３のグラフが示すように、ＤＯ濃度はＮＨ４−Ｎが完全に硝化されるまで低い値を示した。一方、ｐＨは曝気開始２時間までは増加を続け、２−５時間までは減少し、５時間目以降に再度増加した。そのため、同時硝化脱窒が進行している間はｐＨが増加し、硝化が進行している間はｐＨが低下し、硝化完了後に再び増加すると考えられる。同時硝化脱窒進行時におけるｐＨの増加の原因の一つとして、有機酸の酸化が考えられる。また、曝気風量が過大であると、同時硝化脱窒の進行と並行するｐＨの上昇期間は短く、曝気風量が過小であるとｐＨの上昇期間は長くなると考えられる。
FIG. 3 shows the behavior of DO and pH in this experiment. As the graph of FIG. 3 shows, the DO concentration was low until NH4-N was completely nitrified. On the other hand, the pH continued to increase until 2 hours from the start of aeration, decreased until 2-5 hours, and increased again after the 5th hour. Therefore, it is considered that the pH increases while simultaneous nitrification and denitrification is in progress, decreases while nitrification is in progress, and increases again after completion of nitrification. One possible cause of the increase in pH during the simultaneous nitrification and denitrification is the oxidation of organic acids. In addition, if the aeration air volume is excessive, the pH increase period in parallel with the progress of simultaneous nitrification denitrification is short, and if the aeration air volume is too low, the pH increase period is considered to be long.

そこで、本発明では、同時硝化脱窒性能を最大限確保するため、同時硝化脱窒槽１末端において同時硝化脱窒が完了する、つまり、同時硝化脱窒槽１の末端のｐＨが、同時硝化脱窒終了時のｐＨとなるように、第１ブロワ５の風量を制御フローによりコントロールする。   Therefore, in the present invention, simultaneous nitrification denitrification is completed at the end of the simultaneous nitrification denitrification tank 1 in order to ensure the maximum simultaneous nitrification denitrification performance. The air volume of the first blower 5 is controlled by the control flow so that the pH at the end is reached.

図４は第１ブロワ５の風量の制御フロー図である。以下、本実施例における第１曝気風量制御手段１３での制御フローについて詳細に説明する。
FIG. 4 is a control flow chart of the air volume of the first blower 5. Hereinafter, the control flow in the first aeration air volume control means 13 in the present embodiment will be described in detail.

まず、ステップ１０１(以下、Ｓ１０１と称す)において、流量計１０により計測した同時硝化脱窒槽１への流入水量（Ｑ）と、有機物濃度計１１により計測した同時硝化脱窒槽１への流入水の有機物濃度（Ｃｃ）とを取り込む。次に、Ｓ１０２において、同時硝化脱窒槽１への流入有機物負荷（Ｌｃ）を算出する。算出した同時硝化脱窒槽１への流入有機物負荷（Ｌｃ）に応じて、Ｓ１０３において第１ブロワ５の曝気風量の最小値（ｑ1-min）を設定し、Ｓ１０４において同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）を設定する。次に、Ｓ１０５において、例えば、同時硝化脱窒槽１への流入水量（Ｑ）に比例するように第１ブロワ５の曝気風量（ｑ1）を決定する。Ｓ１０６において、第１ｐＨ計９により計測した同時硝化脱窒槽１への流入水のｐＨ（ｐＨ1）と、第２ｐＨ計１２により計測した同時硝化脱窒槽１内のｐＨ（ｐＨ2）を取り込む。次に、Ｓ１０７において、同時硝化脱窒槽１のｐＨ増加量（ΔｐＨ）を算出する。次に、同時硝化脱窒槽１のｐＨ増加量（ΔｐＨ）と、同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）とを比較し、Ｓ１０８のようにΔｐＨ≧ΔｐＨ0であれば、第１ブロワ５の曝気風量は維持する（Ｓ１０９）。一方、ΔｐＨ＜ΔｐＨ0であれば、第１ブロワ５の曝気風量を、第１ブロワ５の曝気風量の最小値（ｑ1-min）以上を維持しながら、減少させる（Ｓ１１０）。
First, in step 101 (hereinafter referred to as S101), the amount of water flowing into the simultaneous nitrification / denitrification tank 1 (Q) measured by the flow meter 10 and the water flowing into the simultaneous nitrification / denitrification tank 1 measured by the organic substance concentration meter 11 The organic matter concentration (Cc) is taken in. Next, in S102, the inflow organic matter load (Lc) to the simultaneous nitrification denitrification tank 1 is calculated. In accordance with the calculated inflow organic matter load (Lc) to the simultaneous nitrification denitrification tank 1, the minimum value (q 1-min ) of the aeration air volume of the first blower 5 is set in S103, and the pH of the simultaneous nitrification denitrification tank 1 in S104. Set the increment reference value (ΔpH 0 ). Next, in S105, for example, the aeration air amount (q 1 ) of the first blower 5 is determined so as to be proportional to the inflow water amount (Q) to the simultaneous nitrification denitrification tank 1. In S106, the pH (pH 1 ) of the inflow water to the simultaneous nitrification denitrification tank 1 measured by the first pH meter 9 and the pH (pH 2 ) in the simultaneous nitrification denitrification tank 1 measured by the second pH meter 12 are taken in. Next, in S107, the pH increase amount (ΔpH) of the simultaneous nitrification denitrification tank 1 is calculated. Next, the pH increase amount (ΔpH) of the simultaneous nitrification denitrification tank 1 is compared with the pH increase amount reference value (ΔpH 0 ) of the simultaneous nitrification denitrification tank 1, and if ΔpH ≧ ΔpH 0 as in S108, The aeration air volume of 1 blower 5 is maintained (S109). On the other hand, if ΔpH <ΔpH 0 , the aeration air volume of the first blower 5 is decreased while maintaining the minimum value (q 1-min ) of the aeration air volume of the first blower 5 (S110).

本実施例では、流量計１０により同時硝化脱窒槽１への流入水量（Ｑ）を計測し、有機物濃度計１１により同時硝化脱窒槽１への流入水の有機物濃度（Ｃｃ）を計測し、第１ｐＨ計９により同時硝化脱窒槽１への流入水のｐＨ（ｐＨ1）を計測したが、必ずしも流量計１０や有機物濃度計１１、第１ｐＨ計９を設置する必要はなく、同時硝化脱窒槽１への流入水の流入水量（Ｑ）や有機物濃度（Ｃｃ）、ｐＨ（ｐＨ1）の変動を記録したデータベースに基づき、同時硝化脱窒槽１への流入水の流入水量（Ｑ）や有機物濃度（Ｃｃ）、ｐＨ（ｐＨ1）を推定しても良い。
In this embodiment, the flow rate 10 measures the amount of inflow water (Q) into the simultaneous nitrification denitrification tank 1, the organic matter concentration meter 11 measures the organic matter concentration (Cc) of the inflow water into the simultaneous nitrification denitrification tank 1, Although the pH (pH 1 ) of the inflow water to the simultaneous nitrification denitrification tank 1 was measured by the 1 pH meter 9, it is not always necessary to install the flow meter 10, the organic substance concentration meter 11, and the first pH meter 9, and the simultaneous nitrification denitrification tank 1 Based on a database that records the changes in the amount of influent water (Q), organic matter concentration (Cc), and pH (pH 1 ), the amount of influent water (Q) and organic matter concentration ( Cc) and pH (pH 1 ) may be estimated.

尚、本実施例では同時硝化脱窒槽１への流入水の有機物濃度（Ｃｃ）を有機物濃度計１０により計測したが、有機物濃度計１０は、吸光光度計（ＵＶ計）、全有機炭素計，生物学的酸素要求量（ＢＯＤ）計、化学的酸素要求量（ＣＯＤ）計など有機物濃度を直接または間接的に算出できるものであれば適用できる。
In this example, the organic matter concentration (Cc) of the inflow water to the simultaneous nitrification / denitrification tank 1 was measured by the organic matter concentration meter 10, and the organic matter concentration meter 10 is composed of an absorptiometer (UV meter), a total organic carbon meter, Any device that can directly or indirectly calculate the organic substance concentration, such as a biological oxygen demand (BOD) meter or a chemical oxygen demand (COD) meter, can be applied.

本実施例では、第２ｐＨ計を同時硝化脱窒槽１の末端に設置したが、同時硝化脱窒領域の末端のｐＨを推定できる所であれば良い。また、同時硝化脱窒槽１と好気槽２とを結ぶ配管内に設置し、同時硝化脱窒槽１の流出水のｐＨを計測しても良い。
In the present embodiment, the second pH meter is installed at the end of the simultaneous nitrification / denitrification tank 1, but it may be any place where the pH at the end of the simultaneous nitrification / denitrification region can be estimated. Moreover, it may install in the piping which connects the simultaneous nitrification denitrification tank 1 and the aerobic tank 2, and may measure the pH of the effluent of the simultaneous nitrification denitrification tank 1.

本実施例では、第１ブロワ５の曝気風量（ｑ1）は下水１００の流入水量（Ｑ）に対して比例になるように設定したが、例えば、一定値を維持する、もしくは有機物や窒素などの下水１００の水質に基づき設定してもよい。
In this embodiment, the aeration air volume (q 1 ) of the first blower 5 is set so as to be proportional to the inflow water volume (Q) of the sewage 100. For example, a constant value is maintained, or organic matter, nitrogen, etc. You may set based on the water quality of the sewage 100.

尚、第１ブロワ５の曝気風量の最小値（ｑ1-min）は、同時硝化脱窒槽１内が嫌気状態にならず、一定量の同時硝化脱窒を保証する風量の最小値である。本開発者の実験結果では、同時硝化脱窒領域の末端のＤＯ濃度が０．１０ｍｇ／Ｌにおいても同時硝化脱窒の進行を確認しており、例えば同時硝化脱窒槽内のＤＯ濃度が０．１０ｍｇ／Ｌ以上となる曝気風量を第１ブロワ５の曝気風量の最小値（ｑ1-min）として設定しても良い。また、第１ブロワ５の曝気風量の最小値（ｑ1-min）は、下水１００の流入水量（Ｑ）や、同時硝化脱窒槽１への流入水の有機物濃度（Ｃｃ）などの水質の線形関数もしくは非線形関数によって設定しても良い。また、下水１００の流入水量（Ｑ）や、同時硝化脱窒槽１への流入水の水質に対する第１ブロワ５の曝気風量の最小値（ｑ1-min）を設定した対応表を作成し、対応表に基づき、第１ブロワ５の曝気風量の最小値（ｑ1-min）を設定しても良い。
The minimum value (q 1-min ) of the aeration air volume of the first blower 5 is the minimum value of the air volume that guarantees a certain amount of simultaneous nitrification and denitrification without being in an anaerobic state in the simultaneous nitrification and denitrification tank 1. According to the experiment results of this developer, the progress of simultaneous nitrification / denitrification was confirmed even when the DO concentration at the end of the simultaneous nitrification / denitrification region was 0.10 mg / L. The aeration air volume that is 10 mg / L or more may be set as the minimum value (q 1-min ) of the aeration air volume of the first blower 5. Moreover, the minimum value (q 1-min ) of the aeration air volume of the first blower 5 is the linearity of water quality such as the inflow water quantity (Q) of the sewage 100 and the organic matter concentration (Cc) of the inflow water to the simultaneous nitrification denitrification tank 1. It may be set by a function or a nonlinear function. Also, create a correspondence table that sets the minimum amount (q 1-min ) of the aeration air volume of the first blower 5 against the inflow water volume (Q) of the sewage 100 and the quality of the inflow water to the simultaneous nitrification denitrification tank 1 Based on the table, the minimum value (q 1-min ) of the aeration air volume of the first blower 5 may be set.

そして、本開発者による実験結果では、同時硝化脱窒領域におけるｐＨ増加量は０．２以上であり、例えば同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）を０．２とすることもできる。ただし、活性汚泥の性状等に応じて、適宜修正することもできる。 In the experiment result by the developer, the pH increase amount in the simultaneous nitrification denitrification region is 0.2 or more. For example, the pH increase reference value (ΔpH 0 ) of the simultaneous nitrification denitrification tank 1 is set to 0.2. You can also. However, it can be modified as appropriate according to the properties of the activated sludge.

また、図５に本願の発明者が回分実験により、下水中の有機物と同時硝化脱窒領域のｐＨ増加量を調べた結果を示す。このグラフが示すように、有機物濃度が高いほど、同時硝化脱窒領域のｐＨ増加量が高い傾向を確認した。そのため、Ｓ１０２において算出した同時硝化脱窒槽１への流入有機物負荷（Ｌｃ）が高いほど、同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）を高く設定することも可能である。同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）の設定方法は、同時硝化脱窒槽１への流入有機物負荷（Ｌｃ）の線形関数もしくは非線形関数によって設定することも可能である。また、同時硝化脱窒槽１への流入有機物負荷（Ｌｃ）に対する同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）を設定した対応表を作成し、対応表に基づき、同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）を設定することも可能である。
Further, FIG. 5 shows the result of the inventors of the present application examining the amount of increase in pH in the sewage organic matter and the simultaneous nitrification denitrification region by a batch experiment. As this graph shows, it was confirmed that the higher the organic substance concentration, the higher the pH increase in the simultaneous nitrification denitrification region. Therefore, the higher the inflow organic matter load (Lc) to the simultaneous nitrification / denitrification tank 1 calculated in S102, the higher the pH increase reference value (ΔpH 0 ) of the simultaneous nitrification / denitrification tank 1 can be set. The method of setting the reference value for the increase in pH (ΔpH 0 ) of the simultaneous nitrification denitrification tank 1 can also be set by a linear function or a nonlinear function of the inflow organic matter load (Lc) to the simultaneous nitrification denitrification tank 1. Further, a correspondence table in which the pH increase reference value (ΔpH 0 ) of the simultaneous nitrification denitrification tank 1 with respect to the inflow organic matter load (Lc) to the simultaneous nitrification denitrification tank 1 is created, and based on the correspondence table, the simultaneous nitrification denitrification tank 1 It is also possible to set a reference value for the amount of increase in pH (ΔpH 0 ).

更に、流量計１０により計測した同時硝化脱窒槽１への流入水量（Ｑ）に基づき、第１ブロワ５の曝気風量の制御は、時間遅れを持つことも可能である。例えば、Ｓ１０７での同時硝化脱窒槽１のｐＨ増加量（ΔｐＨ）の算出において、第１ｐＨ計９による計測値（ｐＨ1）と、第２ｐＨ計による計測値（ｐＨ2）とは、同時刻のものを用いてもよく、また時間遅れを持っても良い。例えば、同時硝化脱窒槽１への流入水量（Ｑ）を用いて、第１ｐＨ計の設置位置から第２ｐＨ計の設置位置までの流下時間（Δｔ）を算出し、時刻ｔにおける第１ｐＨ計の計測値（ｐＨ1）と、時刻ｔ＋Δｔにおける第２ｐＨ計による計測値（ｐＨ2）とから、同時硝化脱窒槽１におけるｐＨの増加量（ΔｐＨ）を算出することも可能である。
Furthermore, the control of the aeration air volume of the first blower 5 based on the amount of inflow water (Q) into the simultaneous nitrification denitrification tank 1 measured by the flow meter 10 can have a time delay. For example, in the calculation of the pH increase (ΔpH) of the simultaneous nitrification denitrification tank 1 in S107, the measured value (pH 1 ) by the first pH meter 9 and the measured value (pH 2 ) by the second pH meter are the same at the same time. A thing may be used and there may be a time delay. For example, the flow time (Δt) from the installation position of the first pH meter to the installation position of the second pH meter is calculated using the amount of inflow water (Q) into the simultaneous nitrification denitrification tank 1, and the measurement by the first pH meter at time t From the value (pH 1 ) and the value (pH 2 ) measured by the second pH meter at time t + Δt, it is also possible to calculate the amount of increase in pH (ΔpH) in the simultaneous nitrification denitrification tank 1.

尚、Ｓ１１０において、第１ブロワ５の曝気風量（ｑ1）の変化量（Δｑ1）の設定は、例えば同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）と、同時硝化脱窒槽１のｐＨ増加量（ΔｐＨ）との差分に比例して制御するＰ制御に基づき設定することも可能である。また、第１ブロワ５の曝気風量（ｑ1）の変化量（Δｑ1）は、同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）に対するＰＩ制御やＰＩＤ制御に基づき、決定することも可能である。また、同時硝化脱窒槽１のｐＨ増加量（ΔｐＨ）、もしくは同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）と、同時硝化脱窒槽１のｐＨ増加量（ΔｐＨ）との差分に対する第１ブロワ５の曝気風量（ｑ1）の変化量（Δｑ1）を設定した対応表を作成し、対応表に基づき、第１ブロワ５の曝気風量（ｑ1）の変化量（Δｑ1）を設定することも可能である。
In S110, the setting of the change amount (Δq 1 ) of the aeration air volume (q 1 ) of the first blower 5 is, for example, the pH increase amount reference value (ΔpH 0 ) of the simultaneous nitrification denitrification tank 1 and the simultaneous nitrification denitrification tank 1 It is also possible to set based on P control which is controlled in proportion to the difference from the pH increase amount (ΔpH). Further, the amount of change (Δq 1 ) of the aeration air volume (q 1 ) of the first blower 5 may be determined based on PI control or PID control with respect to the pH increase reference value (ΔpH 0 ) of the simultaneous nitrification denitrification tank 1. Is possible. In addition, the pH increase amount (ΔpH) of the simultaneous nitrification denitrification tank 1 or the pH increase amount reference value (ΔpH 0 ) of the simultaneous nitrification denitrification tank 1 and the difference between the pH increase amount (ΔpH) of the simultaneous nitrification denitrification tank 1 1 to create a correspondence table set the aeration amount of the blower 5 (q 1) the amount of change ([Delta] q 1), based on the correspondence table, aeration amount of the first blower 5 variation of (q 1) of the ([Delta] q 1) It is also possible to set.

また、同時硝化脱窒槽１における硝化、脱窒の進行状況を評価する補助手段として、同時硝化脱窒槽１にＤＯ濃度計や酸化還元電位（ＯＲＰ）計、ＮＨ４−Ｎ濃度計、ＮＯ３−Ｎ濃度計などを設置することも可能である。例えば、同時硝化脱窒槽１のｐＨ増加量（ΔｐＨ）を用いた第１ブロワ５の曝気風量（ｑ1）の制御に加えて、同時硝化脱窒性能を確保できる同時硝化脱窒槽１のＤＯ濃度やＯＲＰの範囲を設定し、第１ブロワ５の曝気風量（ｑ1）を制御することも可能である。
Further, as an auxiliary means for evaluating the progress of nitrification and denitrification in the simultaneous nitrification / denitrification tank 1, a DO concentration meter, an oxidation-reduction potential (ORP) meter, an NH4-N concentration meter, and a NO3-N concentration are provided in the simultaneous nitrification / denitrification tank 1. It is also possible to install a meter. For example, in addition to controlling the aeration air volume (q 1 ) of the first blower 5 using the pH increase (ΔpH) of the simultaneous nitrification / denitrification tank 1, the DO concentration of the simultaneous nitrification / denitrification tank 1 that can ensure the simultaneous nitrification / denitrification performance It is also possible to set a range of ORP and control the aeration air volume (q 1 ) of the first blower 5.

本実施例では、同時硝化脱窒槽１と好気槽２を隔壁により分離し、それぞれ個別の反応槽としたが、必ずしも個別の反応槽に分離する必要はなく、同一反応槽内にて同時硝化脱窒領域と好気領域とを分離することも可能である。
In the present embodiment, the simultaneous nitrification denitrification tank 1 and the aerobic tank 2 are separated by partition walls, and are made into individual reaction tanks. However, it is not always necessary to separate them into separate reaction tanks, and simultaneous nitrification in the same reaction tank. It is also possible to separate the denitrification region and the aerobic region.

尚、第２ブロワ７の曝気風量制御に関してはその手段を問わない。例えば、第２ブロワ７の曝気風量を一定値に維持する、もしくは下水１００の流入水量（Ｑ）に比例して設定することも可能である。また、第２ブロワ７の曝気風量を、設定した好気槽２の目標水質に応じて制御することも可能である。例えば好気槽２において硝化の完了を目標とする場合、好気槽２のＤＯ濃度やＮＨ４−Ｎの基準値を設定し、基準値を満たすようにＰ制御、もしくはＰＩ制御、もしくはＰＩＤ制御により第２ブロワ７の曝気風量を制御することも可能である。
The means for controlling the aeration air volume of the second blower 7 is not limited. For example, the aeration air volume of the second blower 7 can be maintained at a constant value, or can be set in proportion to the inflow water volume (Q) of the sewage 100. It is also possible to control the aeration air volume of the second blower 7 according to the set target water quality of the aerobic tank 2. For example, when the goal is to complete nitrification in the aerobic tank 2, the DO concentration of the aerobic tank 2 and the reference value of NH4-N are set, and P control, PI control, or PID control is performed so as to satisfy the reference value. It is also possible to control the aeration volume of the second blower 7.

本実施例では、処理方法を標準活性汚泥法としたが、好気状態を有する生物処理方法であれば良く、例えば、嫌気好気活性汚泥法、循環式硝化内生脱窒法、嫌気無酸素好気法、嫌気−硝化内生脱窒法においても適用可能である。
In this embodiment, the standard activated sludge method is used as the treatment method, but any biological treatment method having an aerobic condition may be used.For example, an anaerobic aerobic activated sludge method, a circulating nitrification endogenous denitrification method, an anaerobic anaerobic anaerobic method. It can also be applied to the air method and anaerobic-nitrification endogenous denitrification method.

以上の第１ブロワ５の曝気風量制御により，標準活性汚泥法において、同時硝化脱窒槽１における同時硝化脱窒性能を確保できる。すなわち、同時硝化脱窒槽１において、第１ブロワ５の曝気風量が過大で、硝化が優勢となり、同時硝化脱窒の進行期間が短く、同時硝化脱窒槽１末端のｐＨが低下した場合、第１ブロワ５の曝気風量を抑え、同時硝化脱窒が進行するように制御することを実現できる。
By controlling the aeration air volume of the first blower 5 as described above, the simultaneous nitrification / denitrification performance in the simultaneous nitrification / denitrification tank 1 can be ensured in the standard activated sludge method. That is, in the simultaneous nitrification / denitrification tank 1, when the aeration air volume of the first blower 5 is excessive, nitrification becomes dominant, the progress period of the simultaneous nitrification / denitrification tank is short, and the pH at the end of the simultaneous nitrification / denitrification tank 1 decreases, It is possible to suppress the aeration air volume of the blower 5 and control the simultaneous nitrification denitrification to proceed.

本発明の他の実施例を図面を用いて説明する。   Another embodiment of the present invention will be described with reference to the drawings.

図６は、本発明の実施例２に係る水処理装置の構成を示す構成図である。   FIG. 6 is a configuration diagram illustrating the configuration of the water treatment device according to the second embodiment of the present invention.

本実施例では、前述の実施例１の構成において、同時硝化脱窒槽１において、第２ｐＨ計１２の上流側に第３ｐＨ計測手段である第３ｐＨ計１４を設置し、同時硝化脱窒槽１内のｐＨを計測する構成を備える。   In the present embodiment, in the configuration of the above-described first embodiment, in the simultaneous nitrification denitrification tank 1, a third pH meter 14 as a third pH measurement unit is installed on the upstream side of the second pH meter 12. A configuration for measuring pH is provided.

図７は、実施例２における第１ブロワ５の風量の制御フローを示す。   FIG. 7 shows a control flow of the air volume of the first blower 5 in the second embodiment.

前述の実施例１では、同時硝化脱窒性能を確保するのに必要な第１ブロワ５の曝気風量の最小値（ｑ1-min）を設定したが、実施例２では、第３ｐＨ計測計１４を追加することで、同時硝化脱窒槽１内のｐＨの変化をより詳しく把握し、第１ブロワ５の曝気風量（ｑ1）が第１ブロワ５の曝気風量の最小値（ｑ1-min）以上でありながら、同時硝化脱窒性能が確保できない場合に対応する。 In the above-described first embodiment, the minimum value (q 1-min ) of the aeration air volume of the first blower 5 necessary to ensure the simultaneous nitrification / denitrification performance is set, but in the second embodiment, the third pH meter 14 As a result, the change in pH in the simultaneous nitrification / denitrification tank 1 is grasped in more detail, and the aeration air volume (q 1 ) of the first blower 5 is the minimum value (q 1-min ) of the aeration air volume of the first blower 5. Although it is the above, it corresponds to the case where simultaneous nitrification denitrification performance cannot be secured.

以下、実施例２における第１曝気風量制御手段１３での制御フローについて詳細に説明する。   Hereinafter, the control flow in the first aeration air volume control means 13 in Embodiment 2 will be described in detail.

Ｓ２０５の第１ブロワ５の曝気風量（ｑ１）の決定までは実施例１での制御フローと同一である。Ｓ２０６において第１ｐＨ計９により計測した同時硝化脱窒槽１への流入水のｐＨ（ｐＨ1）と、第２ｐＨ計１２により計測した同時硝化脱窒槽１内のｐＨ（ｐＨ2）と、第３ｐＨ計１４により計測した同時硝化脱窒槽１内のｐＨ（ｐＨ3）を取り込む。次に、Ｓ２０７において、同時硝化脱窒槽１におけるｐＨの増加量（ΔｐＨ）を算出する。次に、同時硝化脱窒槽１でのｐＨ増加量（ΔｐＨ）と、同時硝化脱窒槽１のｐＨ増加量基準値（ΔｐＨ0）とを比較し、Ｓ２０８のようにΔｐＨ≧ΔｐＨ0であれば、第１ブロワ５の風量は維持する（Ｓ２０９）。一方、ΔｐＨ＜ΔｐＨ0であり、かつｐＨ3≦ｐＨ2の場合、硝化が優勢であると判断し、第１ブロワ５の曝気風量（ｑ1）を減少させる（Ｓ２１１）。ΔｐＨ＜ΔｐＨ0であり、かつｐＨ3＞ｐＨ2の場合、同時硝化脱窒の余地があると判断し、第１ブロワ５の曝気風量（ｑ1）を増加させる（Ｓ２１２）。
The control flow is the same as that in the first embodiment until the determination of the aeration air volume (q1) of the first blower 5 in S205. In S206, the pH (pH 1 ) of the inflow water to the simultaneous nitrification / denitrification tank 1 measured by the first pH meter 9, the pH (pH 2 ) in the simultaneous nitrification / denitrification tank 1 measured by the second pH meter 12, and the third pH meter The pH (pH 3 ) in the simultaneous nitrification denitrification tank 1 measured according to 14 is taken in. Next, in S207, the amount of increase in pH (ΔpH) in the simultaneous nitrification denitrification tank 1 is calculated. Next, the pH increase amount (ΔpH) in the simultaneous nitrification denitrification tank 1 is compared with the pH increase amount reference value (ΔpH 0 ) of the simultaneous nitrification denitrification tank 1, and if ΔpH ≧ ΔpH 0 as in S208, The air volume of the first blower 5 is maintained (S209). On the other hand, if ΔpH <ΔpH 0 and pH 3 ≦ pH 2 , it is determined that nitrification is dominant and the aeration air volume (q 1 ) of the first blower 5 is decreased (S211). When ΔpH <ΔpH 0 and pH 3 > pH 2 , it is determined that there is room for simultaneous nitrification and denitrification, and the aeration air volume (q 1 ) of the first blower 5 is increased (S212).

以上の実施例２における第１ブロワ５の曝気風量制御により、曝気風量が過小であり、同時硝化脱窒性能が低下した場合も、第１ブロワ５の曝気風量を増加させることで、同時硝化脱窒の性能を確保することが実現できる。
By controlling the aeration air volume of the first blower 5 in Example 2 above, even when the aeration air volume is too small and the simultaneous nitrification / denitrification performance is reduced, the aeration air volume of the first blower 5 is increased to increase the simultaneous nitrification / denitrification performance. It is possible to ensure the performance of nitrogen.

100 下水
101 処理水
102 返送汚泥
800 返送汚泥の移送流路
1 同時硝化脱窒槽
2 好気槽
3 最終沈殿池
4 第１散気部
5 第１ブロワ
6 第２散気部
7 第２ブロワ
8 返送ポンプ
9 第１ｐＨ計
10 流量計
11 有機物濃度計
12 第２ｐＨ計
13 第１風量制御手段
14 第３ｐＨ計 100 sewage
101 treated water
102 Return sludge
800 Return sludge transfer flow path
1 Simultaneous nitrification denitrification tank
2 Aerobic tank
3 Final sedimentation basin
4 First diffuser
5 First blower
6 Second diffuser
7 Second blower
8 Return pump
9 1st pH meter
10 Flow meter
11 Organic matter concentration meter
12 Second pH meter
13 First air flow control means
14 3rd pH meter

Claims (6)

水処理プロセス制御システムにおいて、
硝化と脱窒を同時に進行させる同時硝化脱窒領域を有する好気槽と、
前記同時硝化脱窒領域の下流に設けられた硝化を進行させる硝化領域と、
前記同時硝化脱窒領域内を曝気する第１曝気手段と、
前記同時硝化脱窒領域への流入水のｐＨを計測する第１ｐＨ計測手段と、
前記同時硝化脱窒領域のｐＨを計測する第２ｐＨ計測手段とを備え、
前記第１ｐＨ計測手段の計測値に対する前記第２ｐＨ計測手段の計測値のｐＨの増加量を
前記同時硝化脱窒領域のｐＨ増加量とし、
前記同時硝化脱窒領域のｐＨ増加量基準値を設定し、
前記同時硝化脱窒領域のｐＨ増加量が、前記同時硝化脱窒領域のｐＨ増加量基準値以上になるように、かつ、一定量の同時硝化脱窒を保証する曝気風量の最小値以上を維持するように前記第１曝気手段による曝気風量を制御する第１曝気風量制御手段を有する
ことを特徴とする水処理プロセス制御システム。
In water treatment process control system,
An aerobic tank having a simultaneous nitrification and denitrification region in which nitrification and denitrification proceed simultaneously;
A nitrification region for promoting nitrification provided downstream of the simultaneous nitrification denitrification region;
First aeration means for aeration in the simultaneous nitrification denitrification region;
First pH measuring means for measuring the pH of the inflow water to the simultaneous nitrification denitrification region;
A second pH measuring means for measuring the pH of the simultaneous nitrification denitrification region,
The amount of increase in pH of the measurement value of the second pH measurement means relative to the measurement value of the first pH measurement means is the amount of increase in pH of the simultaneous nitrification denitrification region,
Set the pH increase reference value of the simultaneous nitrification denitrification region,
The pH increase amount in the simultaneous nitrification denitrification region is equal to or greater than the pH increase reference value of the simultaneous nitrification denitrification region , and the minimum aeration air volume that guarantees a certain amount of simultaneous nitrification denitrification is maintained. A water treatment process control system comprising first aeration air volume control means for controlling the aeration air volume by the first aeration means.
請求項１において、前記ｐＨ増加量基準値を０以上の値に設定したことを特徴とする水処理プロセス制御システム。
 2. The water treatment process control system according to claim 1, wherein the pH increase reference value is set to 0 or more.
請求項１または２において、前記同時硝化脱窒領域のｐＨ増加量が、前記同時硝化脱窒領域のｐＨ増加量基準値を下回った場合、前記第１曝気手段による曝気風量を低減させることを特徴とする水処理プロセス制御システム。
3. The amount of aeration air by the first aeration means is reduced when the pH increase amount of the simultaneous nitrification denitrification region is lower than the pH increase reference value of the simultaneous nitrification denitrification region according to claim 1 or 2. And water treatment process control system.
請求項１乃至３のいずれかにおいて、前記同時硝化脱窒領域内の前記第２ｐＨ計測手段の上流に、前記同時硝化脱窒領域におけるｐＨを計測する第３ｐＨ計測手段を備え、
前記第２ｐＨ計測手段の計測値が前記第３ｐＨ計測手段の計測値を下回った場合、前記第
１曝気手段の風量を低減させることを特徴とする水処理プロセス制御システム。
 In any one of Claims 1 thru / or 3, The 3rd pH measurement means which measures pH in the simultaneous nitrification denitrification field in the upstream of the 2nd pH measurement means in the simultaneous nitrification denitrification field,
The water treatment process control system according to claim 1, wherein when the measurement value of the second pH measurement unit falls below the measurement value of the third pH measurement unit, the air volume of the first aeration unit is reduced.
請求項１乃至４のいずれかにおいて、前記第２ｐＨ計測手段の計測値が前記第３ｐＨ計測手段の計測値を上回った場合、前記第１曝気手段の風量を増加させることを特徴とする水処理プロセス制御システム。
 In any one of claims 1 to 4, wherein the 2pH when the measurement value of the measuring means exceeds the measured value of the first 3pH measuring means, the water treatment process, characterized in that increasing the air volume of the first aeration means Control system.
請求項１乃至５のいずれかにおいて、前記同時硝化脱窒領域の上流に、前記同時硝化脱窒領域への流入有機物負荷を計測する有機物負荷計測手段を備え、前記有機物負荷計測手段の計測値に対して前記同時硝化脱窒領域のｐＨ増加量基準値を設定することを特徴とする水処理プロセス制御システム。 In any one of Claims 1 thru | or 5, It equips upstream of the said simultaneous nitrification denitrification area | region, It comprises the organic substance load measurement means which measures the inflow organic substance load to the said simultaneous nitrification denitrification area | region, It becomes a measurement value of the said organic substance load measurement means. On the other hand, a water treatment process control system characterized in that a pH increase reference value for the simultaneous nitrification denitrification region is set.
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