JPH09141289A - Operation control method for oxidation ditch system - Google Patents
Operation control method for oxidation ditch systemInfo
- Publication number
- JPH09141289A JPH09141289A JP7307032A JP30703295A JPH09141289A JP H09141289 A JPH09141289 A JP H09141289A JP 7307032 A JP7307032 A JP 7307032A JP 30703295 A JP30703295 A JP 30703295A JP H09141289 A JPH09141289 A JP H09141289A
- Authority
- JP
- Japan
- Prior art keywords
- aeration
- mechanical
- respiration rate
- raw water
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- 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
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
Landscapes
- Activated Sludge Processes (AREA)
- Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は下水処理方法の一つ
であるオキシデーション・ディッチ法(以下OD法と略
称)において、呼吸速度計を用いて運転制御する方法に
関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling operation by using a respiration rate meter in an oxidation ditch method (hereinafter abbreviated as OD method) which is one of sewage treatment methods.
【0002】[0002]
【従来の技術】近年における下水道の整備に伴って小規
模な下水処理場での処理方法についても研究が進んでお
り、中でもシステム構成が簡易であり、建設費及び維持
管理費が低廉で処理水質が安定しているOD法が注目さ
れている。このOD法とは活性汚泥法の一種であり、図
6に示したように適宜な水深を有する無終端水路で成る
楕円形の生物反応槽1内に原水2を流入して隔壁4を利
用して循環流を作り、ロータ等の機械的曝気撹拌機3を
用いて矢印Aに示したように原水を循環させながら活性
汚泥と混合して、処理に必要な酸素を供給する。2. Description of the Related Art With the recent improvement of sewerage, research on treatment methods at small-scale sewage treatment plants is progressing. Above all, the system configuration is simple, construction cost and maintenance cost are low, and treated water quality is low. The OD method, which is stable, is drawing attention. This OD method is a type of activated sludge method. As shown in FIG. 6, raw water 2 is introduced into an elliptic biological reaction tank 1 which is an endless water channel having an appropriate water depth, and partition walls 4 are used. A circulation flow is created by using a mechanical aeration stirrer 3 such as a rotor to mix the raw water with the activated sludge while circulating the raw water as shown by the arrow A to supply oxygen necessary for the treatment.
【0003】5は最終沈澱池であり、この最終沈澱池5
の上澄液は処理水6として図外の消毒槽等を経由してか
ら放流され、該最終沈澱池5内に沈降した汚泥の一部は
管路7を経由して生物反応槽1に返送され、余剰汚泥8
は図外の余剰汚泥処理装置に送り込まれて処理される。
機械的曝気撹拌機3は生物反応槽1基につき1台か2
台、もしくは4台使用されるのが通例である。Reference numeral 5 is a final sedimentation pond, and this final sedimentation pond 5
The supernatant liquid is discharged as treated water 6 through a disinfecting tank (not shown), etc., and a part of the sludge settled in the final settling tank 5 is returned to the biological reaction tank 1 via a pipe 7. And excess sludge 8
Is sent to a surplus sludge treatment device (not shown) for treatment.
1 or 2 mechanical aeration mixers per bioreactor
It is customary to use four or four units.
【0004】このOD法は流入する原水2の水理学的滞
留時間(HRT)が標準活性汚泥法よりも長く設定され
ることと、活性汚泥浮遊物(MLSS)を高くすること
により、容積負荷と汚泥負荷がともに低く運転されると
いう特徴がある。従って流入負荷変動に強く、汚泥発生
量が少ないという長所があり、維持管理が比較的容易で
あることから小規模な下水処理場での採用数が増えてい
る現状にある。In this OD method, the hydraulic retention time (HRT) of the inflowing raw water 2 is set to be longer than that of the standard activated sludge method, and the activated sludge suspended matter (MLSS) is increased so that the volume load is increased. It has the characteristic that both sludge load is low. Therefore, it has the advantages that it is resistant to fluctuations in inflow load and that the amount of sludge generated is small, and because it is relatively easy to maintain and manage, the number of small-scale sewage treatment plants is increasing.
【0005】他方で閉鎖性水域での富栄養化を防止する
ため、下水処理においても原水中の窒素とかリンを低減
することが要求されている。OD法における窒素除去は
無終端水路内の流れ方向に溶存酸素(DO)の濃度勾配
を設けて部分的に嫌気・好気状態を作り、脱窒・硝化反
応を起こすことによって行うことが可能であるが、この
際には生物反応槽1内にDOの濃度勾配を保ちながら汚
泥の混合状態を均一に保つことが重要である。On the other hand, in order to prevent eutrophication in a closed water area, it is required to reduce nitrogen and phosphorus in raw water during sewage treatment. Nitrogen removal in the OD method can be performed by providing a concentration gradient of dissolved oxygen (DO) in the flow direction in the endless water channel to partially create an anaerobic / aerobic state and causing a denitrification / nitrification reaction. However, in this case, it is important to keep the mixing state of sludge uniform while maintaining the DO concentration gradient in the biological reaction tank 1.
【0006】[0006]
【発明が解決しようとする課題】上記したOD法は基本
的に低負荷運転で行われるように設定されているが、運
転開始の初期には更に負荷が小さくなっているのが一般
的であって、計画水量になるまでかなりの時間を要する
ことが知られている。このように時に連続して撹拌動作
を実施すると、溶存酸素濃度(以下DO濃度と略称)が
高くなり、所謂過曝気の状態になり易いという課題があ
る。The above-mentioned OD method is basically set to be carried out at low load operation, but the load is generally smaller at the beginning of operation. It is known that it takes a considerable amount of time to reach the planned water volume. When the stirring operation is continuously performed as described above, the dissolved oxygen concentration (hereinafter abbreviated as DO concentration) increases, and there is a problem that a so-called over-aeration state is likely to occur.
【0007】過曝気状態になると汚泥が分散してしま
い、最終沈澱池5における汚泥の沈澱分離性が低下して
処理水質が悪化する惧れが生じる。更に全体的にDO濃
度が高くなることによって嫌気状態を必要とする脱窒反
応が生じにくくなるので、窒素除去率も低下することに
なる。[0007] In the over-aeration state, sludge is dispersed, and the sedimentation separability of sludge in the final settling basin 5 is deteriorated, which may deteriorate the quality of treated water. Further, since the DO concentration becomes higher as a whole, the denitrification reaction that requires an anaerobic state is less likely to occur, so that the nitrogen removal rate also decreases.
【0008】上記に対処して、ある時間帯に前記撹拌機
による撹拌動作を停止することによる間欠曝気を実施す
る手段も知られているが、このような間欠曝気手段は、
曝気と停止の時間比とか1サイクルの合計時間の設定に
よって処理効率が異なってくるため、これら時間比及び
合計時間を最適に設定することは技術的に困難であると
いう問題がある。[0008] In response to the above, means for carrying out intermittent aeration by stopping the stirring operation by the agitator at a certain time is also known, but such intermittent aeration means is
Since the processing efficiency varies depending on the setting of the aeration / stopping time ratio or the total time of one cycle, there is a problem that it is technically difficult to optimally set the time ratio and the total time.
【0009】又、計画水量に近い原水の流入水量を確保
して連続運転する場合には、曝気撹拌機の運転台数とか
撹拌回転数を変えてDO濃度分布を調節する方法が採ら
れるが、負荷変動とか季節の変化に伴う水温変化等の影
響を考慮して上記要因を最適に調節すことき困難であ
る。例えば低負荷時にはDO濃度が高くなるため、嫌気
状態の部分が小さくなり、場合によっては反応槽全体が
好気状態になる可能性がある。このような場合には窒素
除去効果が極端に低下してしまう惧れがある。Further, in the case of continuously operating with the inflow of raw water close to the planned amount of water secured, a method of adjusting the DO concentration distribution by changing the operating number of aeration agitators or the agitation rotation number is used, but the load It is difficult to optimally adjust the above factors in consideration of the effects of fluctuations and changes in water temperature due to seasonal changes. For example, when the load is low, the DO concentration becomes high, so that the anaerobic portion becomes small, and in some cases, the entire reaction tank may become aerobic. In such a case, there is a fear that the nitrogen removing effect will be extremely lowered.
【0010】逆に高負荷時には嫌気状態の部分が多くな
り、好気状態で生じる硝化反応が停止して、結果として
窒素除去率が低下する惧れがある。この嫌気と好気の部
分を最適に制御する手法は開発されていないのが実情で
ある。On the other hand, when the load is high, the anaerobic portion increases, the nitrification reaction that occurs in the aerobic state is stopped, and as a result, the nitrogen removal rate may decrease. The reality is that no method has been developed for optimally controlling this anaerobic and aerobic part.
【0011】そこで本発明は上記に鑑みてなされたもの
であり、機械的曝気撹拌機の曝気と停止の時間比等の制
御因子を最適に設定して、過曝気を防止して汚泥の沈澱
分離性を高め、且つDO濃度が高くなることに伴う窒素
除去率の低下を防止して処理水質の向上をはかることが
できる運転制御方法を提供することを目的とするもので
ある。Therefore, the present invention has been made in view of the above, and optimally sets a control factor such as a time ratio of aeration and stop of a mechanical aeration stirrer to prevent excessive aeration and to separate sludge sedimentation. It is an object of the present invention to provide an operation control method capable of improving the quality of treated water by improving the quality of the treated water and preventing the decrease in the nitrogen removal rate due to the increase in the DO concentration.
【0012】[0012]
【課題を解決するための手段】本発明は上記の目的を達
成するために、無終端水路で成る生物反応槽内に原水を
流入して、水路に配備した機械的曝気撹拌機による曝気
作用を伴って原水を循環させながら活性汚泥と混合処理
するようにしたオキシデーション・ディッチ法による水
処理装置において、先ず請求項1により、原水流入口の
下流側に呼吸速度計を設置して、この呼吸速度計の計測
値に基づいて、制御装置により機械的曝気撹拌機の曝気
及び曝気停止状態を駆動制御する運転制御方法を提供す
る。[Means for Solving the Problems] In order to achieve the above object, the present invention allows raw water to flow into a bioreaction tank consisting of a non-terminating water channel to perform aeration by a mechanical aeration stirrer installed in the channel. In the water treatment apparatus by the oxidation-ditch method, in which the raw water is circulated and mixed with the activated sludge, first, according to claim 1, a respiration rate meter is installed on the downstream side of the raw water inlet, There is provided an operation control method in which a control device drives and controls aeration and an aeration stop state of a mechanical aeration stirrer based on a measurement value of a speedometer.
【0013】請求項2により、機械的曝気撹拌機の上流
側に呼吸速度計を設置するとともに、この機械的曝気撹
拌機の下流側に溶存酸素濃度計を設置して、呼吸速度計
の計測値が高い場合には機械的曝気撹拌機による酸素供
給を増大する制御を実施する一方、呼吸速度計の計測値
が低い場合には酸素供給を減少するような制御を実施
し、溶存酸素濃度の計測値と上記呼吸速度値とから溶存
酸素濃度がゼロになる位置を予測して機械的曝気撹拌機
の曝気及び曝気停止状態を駆動制御する。According to claim 2, a respiration rate meter is installed on the upstream side of the mechanical aeration stirrer, and a dissolved oxygen concentration meter is installed on the downstream side of the mechanical aeration stirrer. When the value is high, control is performed to increase the oxygen supply by the mechanical aeration stirrer, while when the measured value of the respiration rate meter is low, control is performed to reduce the oxygen supply to measure the dissolved oxygen concentration. The position where the dissolved oxygen concentration becomes zero is predicted from the value and the respiration rate value, and the aeration and aeration stop state of the mechanical aeration mixer are drive-controlled.
【0014】更に請求項3により、上記生物反応槽内に
複数台の機械的曝気撹拌機と呼吸速度計を設置して、こ
の呼吸速度計の計測値に基づいて、制御装置により複数
台の機械的曝気撹拌機の曝気及び曝気停止状態を個別に
駆動制御するようにしたオキシデーション・ディッチ法
における運転制御方法を提供する。Further, according to claim 3, a plurality of mechanical aeration stirrers and a respiration rate meter are installed in the biological reaction tank, and a plurality of machines are controlled by the controller based on the measured value of the respiration rate meter. Provided is an operation control method in an oxidation ditch method in which the aeration and aeration stop states of a static aeration stirrer are individually driven and controlled.
【0015】かかる請求項1記載の運転制御方法によれ
ば、流入汚濁物質濃度が高く微生物の呼吸速度も高い場
合には、呼吸速度の計測値に基づいて制御装置によって
機械的曝気撹拌機による曝気時間の設定を長くし、逆に
流入汚濁物質濃度が低い場合には、機械的曝気撹拌機に
よる曝気時間を短縮するか該撹拌機の停止時間を長くす
るような制御を実施する。According to the operation control method of the first aspect, when the influent pollutant concentration is high and the respiration rate of microorganisms is also high, the control device controls the aeration by the mechanical aeration mixer based on the measured respiration rate. When the time setting is made longer and conversely the inflowing pollutant concentration is low, control is performed such that the aeration time by the mechanical aeration stirrer is shortened or the stirrer is stopped for a long time.
【0016】請求項2記載の運転制御方法によれば、上
記作用に加えて溶存酸素濃度計によって溶存酸素濃度を
計測して、DO値と前記呼吸速度値とからDOがゼロに
なる位置を計算によって求め、これら計測値と計算値に
よって機械的曝気撹拌機の回転数を変えることにより、
好気状態の時間とか範囲が最適に決定される。According to the operation control method of the second aspect, in addition to the above action, the dissolved oxygen concentration is measured by the dissolved oxygen concentration meter, and the position where DO becomes zero is calculated from the DO value and the respiration rate value. By changing the number of rotations of the mechanical aeration agitator by these measured values and calculated values,
The aerobic time and range are optimally determined.
【0017】[0017]
【発明の実施の形態】以下図面に基づいて本発明にかか
るオキシデーション・ディッチ法における運転制御方法
の各種実施例を前記従来例の構成部分と同一の構成部分
に同一の符号を付して説明する。図1は本発明の第1実
施例を示す要部概略図であって、前記したように適宜の
水深を有する無終端水路で成る楕円形の生物反応槽1内
に原水2を流入して、ロータ等の機械的曝気撹拌機3を
駆動モータ3aの駆動力により回転して矢印Aに示した
原水の循環流を作る。そして原水2を活性汚泥と混合し
て機械的曝気撹拌機3により処理に必要な酸素を供給す
る。4は無終端水路を画成するための隔壁である。9は
図外の最終沈澱池内に沈降した汚泥から生物反応槽1へ
返送された返送汚泥である。BEST MODE FOR CARRYING OUT THE INVENTION Various embodiments of an operation control method in an oxidation / ditch method according to the present invention will be described below with reference to the drawings, in which the same components as those of the conventional example are designated by the same reference numerals. To do. FIG. 1 is a schematic view of a main part showing a first embodiment of the present invention, in which raw water 2 is introduced into an elliptical biological reaction tank 1 formed of an endless water channel having an appropriate water depth as described above, The mechanical aeration stirrer 3 such as a rotor is rotated by the driving force of the drive motor 3a to create a circulating flow of raw water shown by an arrow A. Then, the raw water 2 is mixed with the activated sludge and the mechanical aeration stirrer 3 supplies oxygen necessary for the treatment. Reference numeral 4 is a partition wall for defining an endless water channel. Reference numeral 9 is a sludge returned from the sludge settled in the final settling tank (not shown) to the biological reaction tank 1.
【0018】この第1実施例では、原水2の流入口の少
し下流側に呼吸速度計(Rr計と略称される)10が設
置されていて、この呼吸速度計10の計測値が制御装置
11に入力されている。そして該制御装置11の制御出
力11aにより機械的曝気撹拌機3の駆動状態が制御さ
れる。ここで機械的曝気撹拌機3の数は1台に限定され
るものではなく、必要に応じて数台設置する場合もあ
る。In the first embodiment, a respiration rate meter (abbreviated as Rr meter) 10 is installed slightly downstream of the inlet of the raw water 2, and the measured value of the respiration rate meter 10 is the control device 11. Has been entered in. Then, the drive state of the mechanical aeration stirrer 3 is controlled by the control output 11a of the control device 11. Here, the number of mechanical aeration stirrers 3 is not limited to one, and several may be installed as needed.
【0019】かかる第1実施例によれば、通常運転時に
は機械的曝気撹拌機3の間欠回転による曝気作用(エア
レーション)を伴って原水2が矢印Aに示す方向に流
れ、生物反応槽1内を隔壁4に沿って循環しながら活性
汚泥と混合して反応が進行する。反応終了後に流出水1
2として図外の最終沈澱池に送り込まれる。According to the first embodiment, during the normal operation, the raw water 2 flows in the direction shown by the arrow A with the aeration action (aeration) due to the intermittent rotation of the mechanical aeration stirrer 3 and flows in the biological reaction tank 1. The reaction proceeds by mixing with activated sludge while circulating along the partition walls 4. Effluent 1 after reaction
2 is sent to the final sedimentation pond outside the figure.
【0020】そして原水2の流入汚濁物質濃度が高い場
合には、微生物の呼吸速度Rrも高くなるので、曝気の
開始後にDO濃度の上昇速度が遅くなったり、基質の酸
化分解の所要時間が長くなったりする。そこで呼吸速度
計10によって微生物の呼吸速度Rrを計測し、得られ
た計測値を制御装置11に入力する。そして該制御装置
11の制御出力11aによって駆動モータ3aを駆動制
御することにより、機械的曝気撹拌機3による曝気時間
の設定を長くするような制御を実施する。When the concentration of pollutants in the raw water 2 is high, the respiration rate Rr of the microorganisms is also high, so that the rate of increase of the DO concentration is slow after the start of aeration, and the time required for the oxidative decomposition of the substrate is long. To become. Therefore, the respiration rate Rr of the microorganism is measured by the respiration rate meter 10, and the obtained measurement value is input to the control device 11. Then, by controlling the drive motor 3a by the control output 11a of the control device 11, control is performed to lengthen the aeration time set by the mechanical aeration stirrer 3.
【0021】逆に流入汚濁物質濃度が低い場合には、微
生物の呼吸速度Rrも低くなるので、曝気停止後のDO
濃度の低下に要する時間が長くなって脱窒反応のための
嫌気時間が短くなる。このような場合には呼吸速度計1
0によって計測した微生物の呼吸速度Rrに基づいて、
制御装置11の制御出力11aによって同様に駆動モー
タ3aを駆動制御して、機械的曝気撹拌機3による曝気
時間を短縮し、該撹拌機の停止時間を長くするような制
御を実施する。On the contrary, when the concentration of the inflowing pollutant is low, the respiration rate Rr of the microorganisms is also low, so that the DO after the aeration is stopped.
The time required for lowering the concentration becomes longer and the anaerobic time for the denitrification reaction becomes shorter. In such a case, respiration rate meter 1
Based on the respiration rate Rr of the microorganism measured by 0,
Similarly, the drive output of the drive motor 3a is controlled by the control output 11a of the control device 11 to shorten the aeration time of the mechanical aeration stirrer 3 and extend the stop time of the stirrer.
【0022】かかる制御を行うことにより、呼吸速度計
10の計測値によって流入汚濁物質濃度に起因する負荷
変動を検出し、間欠運転における曝気時間と停止時間の
制御を最適に実施することができる。By performing such control, it is possible to detect the load fluctuation due to the inflowing pollutant concentration by the measurement value of the respiration rate meter 10 and optimally control the aeration time and the stop time in the intermittent operation.
【0023】ここで呼吸速度計10の測定原理を簡単に
説明すると、通常活性度の評価として活性汚泥の呼吸速
度が用いられており、この呼吸速度計の動作原理は試料
水の溶存酸素(DO)の減衰速度から計算により求める
のが通例である。具体的には試料水を測定槽内に導入
し、活性汚泥を曝気してDO濃度を高めてから曝気を停
止して撹拌を実施すると、活性汚泥の好気性微生物によ
る酸素消費に伴ってDO濃度が低下するので、これをD
O計により測定してDOの減少速度から最小自乗法によ
り活性汚泥の呼吸速度が算出される。The measurement principle of the respiration rate meter 10 will be briefly described. Normally, the respiration rate of activated sludge is used as an evaluation of activity. The operation principle of this respiration rate meter is that dissolved oxygen (DO) in sample water is used. It is customary to calculate from the decay rate of). Specifically, when the sample water is introduced into the measuring tank, the activated sludge is aerated to increase the DO concentration, and then the aeration is stopped and stirring is performed, the DO concentration is increased due to the oxygen consumption by the aerobic microorganisms of the activated sludge. Will decrease, so change this to D
The respiration rate of the activated sludge is calculated by the least squares method from the reduction rate of DO measured by the O meter.
【0024】次に図2により本発明の第2実施例を説明
する。この第2実施例の基本的構成は第1実施例と同様
であり、同一の符号を付して表示してある。この例では
機械的曝気撹拌機3の上流側に呼吸速度計10が設置さ
れているとともに、この機械的曝気撹拌機3の下流側に
溶存酸素濃度計13(DO計)が設置されている。Next, a second embodiment of the present invention will be described with reference to FIG. The basic structure of the second embodiment is similar to that of the first embodiment, and is designated by the same reference numeral. In this example, the respiration rate meter 10 is installed on the upstream side of the mechanical aeration stirrer 3, and the dissolved oxygen concentration meter 13 (DO meter) is installed on the downstream side of the mechanical aeration stirrer 3.
【0025】この第2実施例では、流入汚濁物質濃度が
高い場合には呼吸速度計10の計測値も高くなるため、
制御装置11の制御出力11aによって駆動モータ3a
の回転数を上げて酸素供給を増大するような制御を実施
し、逆に呼吸速度計10の計測値が低い場合には、無駄
な酸素供給を避けるために駆動モータ3aの回転数を下
げて酸素供給を減少するような制御を実施する。更にD
O計13によって溶存酸素濃度を計測して、DO値と前
記Rr値とからDOがゼロになる位置を計算によって求
める。In the second embodiment, since the measured value of the respiration rate meter 10 becomes high when the inflowing pollutant concentration is high,
The drive motor 3a is controlled by the control output 11a of the controller 11.
When the respiration rate meter 10 has a low measurement value, the rotation speed of the drive motor 3a is decreased to avoid unnecessary oxygen supply. Control is performed to reduce the oxygen supply. Further D
The dissolved oxygen concentration is measured by the O meter 13, and the position at which DO becomes zero is calculated from the DO value and the Rr value.
【0026】これらの計測値と計算値によって機械的曝
気撹拌機3の回転数を変えることにより、好気状態の時
間とか好気部分の範囲を最適に決定することができる。By changing the number of revolutions of the mechanical aeration stirrer 3 based on these measured values and calculated values, it is possible to optimally determine the time of the aerobic state or the range of the aerobic portion.
【0027】次に図3により本発明の第3実施例を説明
する。この第3実施例は機械的曝気撹拌機を2台設置し
た例であり、原水2の流入口の下流側に1台目の機械的
曝気撹拌機14と駆動モータ3bが設置され、この1台
目の機械的曝気撹拌機14の下流側に前記実施例と同様
な呼吸速度計10と2台目の機械的曝気撹拌機3,駆動
モータ3aとが設置されている。1台台目の機械的曝気
撹拌機14に付設された駆動モータ3bは予め設定され
た固定速度で常時回転している。Next, a third embodiment of the present invention will be described with reference to FIG. The third embodiment is an example in which two mechanical aeration stirrers are installed, and the first mechanical aeration stirrer 14 and the drive motor 3b are installed on the downstream side of the inflow port of the raw water 2. On the downstream side of the eye mechanical aeration stirrer 14, a respiration rate meter 10 similar to that of the above embodiment, a second mechanical aeration stirrer 3 and a drive motor 3a are installed. The drive motor 3b attached to the first mechanical aeration stirrer 14 is constantly rotating at a preset fixed speed.
【0028】この実施例では呼吸速度計10の計測値に
よって流入汚濁物質濃度に起因する負荷変動を検出し
て、間欠運転における駆動モータ3aによる機械的曝気
撹拌機3の曝気時間と停止時間の制御だけを実施する。
尚、駆動モータ3aが可変速の場合には回転数の制御を
行い、駆動モータ3aが固定速度で回転する場合にはオ
ンオフ制御となる。In this embodiment, the load fluctuation caused by the inflowing pollutant concentration is detected by the measurement value of the respiration rate meter 10, and the aeration time and the stop time of the mechanical aeration stirrer 3 by the drive motor 3a in the intermittent operation are controlled. Only carry out.
When the drive motor 3a has a variable speed, the rotation speed is controlled, and when the drive motor 3a rotates at a fixed speed, the on / off control is performed.
【0029】前記流入汚濁物質濃度は曝気機3,14に
より供給される酸素を利用して活性汚泥により分解され
るものであるから、下流側になるほど汚濁物質濃度は低
くなる。そこで図3に示したRr計10が設置された位
置で汚濁物質に分解が終了しているならば、Rr計10
の計測値は内性呼吸だけの消費速度になり、分解が終了
していなければ汚濁物質の分解に要する値が加算された
消費速度となる。Since the inflow pollutant concentration is decomposed by activated sludge using oxygen supplied from the aerators 3 and 14, the pollutant concentration becomes lower toward the downstream side. Therefore, if the decomposition into pollutants is completed at the position where the Rr meter 10 shown in FIG.
The measured value of is the consumption rate of only internal respiration, and if the decomposition is not completed, it becomes the consumption rate to which the value required for decomposition of pollutants is added.
【0030】従って計測されたRr値によって内性呼吸
状態であることが判定された場合には、原水2の流入口
から2台目の曝気機である機械的曝気撹拌機3の駆動を
停止するか、もしくは回転数を最低限まで下げた運転を
行えばよく、逆に分解が終了していなければ該機械的曝
気撹拌機3の駆動を継続するか、回転数を上げて運転を
行うという制御を実施する。Therefore, when it is determined from the measured Rr value that the state is the internal respiration state, the drive of the mechanical aeration agitator 3 which is the second aerator from the inlet of the raw water 2 is stopped. Alternatively, the operation may be performed by lowering the rotation speed to the minimum. On the contrary, if the decomposition is not completed, the drive of the mechanical aeration stirrer 3 is continued or the operation is performed by increasing the rotation speed. Carry out.
【0031】図4は本発明の第4実施例を示す要部概略
図であり、この例では2台設置した機械的曝気撹拌機の
中で、原水2の流入口から流入方向へ向けて1台目の機
械的曝気撹拌機14の駆動モータ3bを可変速とし、2
台目の機械的曝気撹拌機3の駆動モータ3aは予め設定
された固定速で回転している。Rr計10は2台目の機
械的曝気撹拌機3の上流側に設置されている。従って制
御装置11の制御出力11aは1台目の機械的曝気撹拌
機14の駆動モータ3bに入力されている。FIG. 4 is a schematic view of an essential part showing a fourth embodiment of the present invention. In this example, in two mechanical aeration mixers installed, 1 from the inlet of raw water 2 toward the inflow direction The drive motor 3b of the second mechanical aeration stirrer 14 is set to a variable speed, and 2
The drive motor 3a of the third mechanical aeration mixer 3 is rotating at a preset fixed speed. The Rr meter 10 is installed on the upstream side of the second mechanical aeration stirrer 3. Therefore, the control output 11a of the control device 11 is input to the drive motor 3b of the first mechanical aeration mixer 14.
【0032】この第4実施例ではRr計10の計測値に
対する評価は前記第3実施例と同様であり、Rr値によ
って内性呼吸状態であることが判定された場合には、原
水2の流入口から1台目の曝気機である機械的曝気撹拌
機14の駆動を停止するか、もしくは回転数を最低限ま
で下げた運転を行えばよく、逆に分解が終了していなけ
れば該機械的曝気撹拌機14の駆動を継続するか、回転
数を上げて運転を行うという制御を実施する。In the fourth embodiment, the evaluation of the measurement value of the Rr meter 10 is the same as that in the third embodiment, and when the Rr value is judged to be the internal respiratory state, the flow rate of the raw water 2 is increased. The drive of the mechanical aeration stirrer 14 which is the first aerator from the inlet may be stopped or the operation may be performed with the number of rotations lowered to the minimum. Control is performed such that the aeration stirrer 14 is continuously driven or the rotation speed is increased to perform the operation.
【0033】図5は本発明の第5実施例を示す概略図で
あり、この例は前記第4実施例における2台設置した機
械的曝気撹拌機3,14の駆動モータ3a,3bをとも
に可変速とした例であり、制御装置11の制御出力11
aは両機械的曝気撹拌機の駆動モータ3a,3bに入力
されている。FIG. 5 is a schematic view showing a fifth embodiment of the present invention. In this embodiment, both drive motors 3a and 3b of the mechanical aeration stirrers 3 and 14 installed in the fourth embodiment can be used. This is an example of gear shifting, and the control output 11 of the control device 11
a is input to the drive motors 3a and 3b of both mechanical aeration mixers.
【0034】この第5実施例では、Rr値によって内性
呼吸状態であることが判定された場合には、先ず原水2
の流入口から2台目の曝気機である機械的曝気撹拌機3
の駆動を停止するか、もしくは回転数を最低限まで下げ
た運転を行い、それでも内性呼吸状態である場合には、
1台目の曝気機である機械的曝気撹拌機14の駆動停止
もしくは回転数を下げた運転を行う。逆に分解が終了し
ていなければ1台目の機械的曝気撹拌機14の回転数を
上げ、それでも内性呼吸状態にならない場合には、2台
目の機械的曝気撹拌機3の回転数を上げて運転を行うと
いう制御を実施する。In the fifth embodiment, when it is determined that the Rr value is the internal respiratory state, first, the raw water 2
Mechanical aeration stirrer 3 which is the second aerator from the inlet of
If you stop the drive of or drive with the rotation speed reduced to the minimum and still have an internal respiratory condition,
The drive of the mechanical aeration stirrer 14 which is the first aerator is stopped or operation is performed with the rotation speed reduced. On the contrary, if the decomposition is not completed, the rotation speed of the first mechanical aeration stirrer 14 is increased, and if the internal respiratory state is still not reached, the rotation speed of the second mechanical aeration stirrer 3 is increased. The control is carried out by raising the speed of operation.
【0035】[0035]
【発明の効果】以上詳細に説明したように、本発明にか
かるオキシデーション・ディッチ法における運転制御方
法によれば、以下に記す作用効果がもたらされる。即
ち、原水の汚濁物質濃度が高く微生物の呼吸速度も高い
場合には、呼吸速度の計測値に基づいて機械的曝気撹拌
機による曝気時間の設定を長くし、逆に流入汚濁物質濃
度が低い場合には、曝気時間を短縮するか停止時間を長
くするような制御を実施することにより、連続撹拌動作
に基づく過曝気を防止して汚泥の沈澱分離性を高めるこ
とができる。As described in detail above, according to the operation control method in the oxidation / ditch method according to the present invention, the following operational effects are brought about. That is, when the pollutant concentration of raw water is high and the respiration rate of microorganisms is also high, the aeration time is set longer by the mechanical aeration agitator based on the measured respiration rate. In this case, by performing control such that the aeration time is shortened or the stop time is lengthened, it is possible to prevent over-aeration based on the continuous stirring operation and enhance the sludge sedimentation separability.
【0036】又、請求項2記載の運転制御方法によれ
ば、上記効果に加えて溶存酸素濃度計によって計測され
たDO値と呼吸速度値とからDOがゼロになる位置を計
算によって求め、これら計測値と計算値によって機械的
曝気撹拌機の回転数を変えることにより、好気状態の時
間とか範囲を最適に決定することができる。According to the operation control method of the second aspect, in addition to the above effects, the position where DO becomes zero is calculated from the DO value and the respiration rate value measured by the dissolved oxygen concentration meter, and these values are calculated. By changing the rotation speed of the mechanical aeration stirrer based on the measured value and the calculated value, the time and range of the aerobic condition can be optimally determined.
【0037】従って本発明によれば、全体的にDO濃度
が高くなることによる窒素除去率の低下がなくなり、計
画水量に近い原水の流入水量を確保して連続運転する場
合でも機械的曝気撹拌機の曝気と停止の時間比等の制御
因子を最適に設定することができるため、前記過曝気の
防止とともにDO濃度が高くなることに伴う窒素除去率
の低下を防止し、処理水質の向上をはかることができる
運転制御方法を提供することができる。Therefore, according to the present invention, there is no decrease in the nitrogen removal rate due to an increase in the DO concentration as a whole, and a mechanical aeration stirrer is used even when continuous operation is performed with an inflow of raw water close to the planned amount of water being secured. Since it is possible to optimally set the control factors such as the time ratio of the aeration and the stoppage, the nitrogen removal rate is prevented from lowering due to the increase of the DO concentration and the treated water quality is improved together with the prevention of the over-aeration. It is possible to provide an operation control method capable of performing the operation control.
【図1】本発明の第1実施例を示す要部概略図。FIG. 1 is a schematic view of a main part showing a first embodiment of the present invention.
【図2】本発明の第2実施例を示す要部概略図。FIG. 2 is a schematic view of a main part showing a second embodiment of the present invention.
【図3】本発明の第3実施例を示す要部概略図。FIG. 3 is a schematic view of a main part showing a third embodiment of the present invention.
【図4】本発明の第4実施例を示す要部概略図。FIG. 4 is a schematic view of a main part showing a fourth embodiment of the present invention.
【図5】本発明の第5実施例を示す要部概略図。FIG. 5 is a schematic view of a main part showing a fifth embodiment of the present invention.
【図6】下水処理方法の一つであるオキシデーション・
ディッチ法を説明するための概要図。[Fig. 6] Oxidation, which is one of the sewage treatment methods
Schematic diagram for explaining the Ditch method.
1…生物反応槽 2…原水 3,14…機械的曝気撹拌機 3a,3b…駆動モータ 4…隔壁 5…最終沈澱池 9…返送汚泥 10…呼吸速度計 11…制御装置 13…溶存酸素濃度計 21…駆動モータ 1 ... Biological reaction tank 2 ... Raw water 3,14 ... Mechanical aeration stirrer 3a, 3b ... Drive motor 4 ... Partition wall 5 ... Final sedimentation tank 9 ... Return sludge 10 ... Respiratory speed meter 11 ... Control device 13 ... Dissolved oxygen concentration meter 21 ... Drive motor
Claims (3)
流入して、水路に配備した機械的曝気撹拌機による曝気
作用を伴って原水を循環させながら活性汚泥と混合処理
するようにしたオキシデーション・ディッチ法による水
処理装置において、 原水流入口の下流側に呼吸速度計を設置して、この呼吸
速度計の計測値に基づいて、制御装置により機械的曝気
撹拌機の曝気及び曝気停止状態を駆動制御することを特
徴とするオキシデーション・ディッチ法における運転制
御方法。1. Raw water is allowed to flow into a biological reaction tank consisting of an endless water channel, and the raw water is circulated with the aeration action of a mechanical aeration stirrer installed in the water channel to perform a mixed treatment with activated sludge. In a water treatment device using the oxidation-ditch method, a respiration rate meter is installed on the downstream side of the raw water inlet, and based on the measurement value of this respiration rate meter, the controller aerates and stops aeration of the mechanical aerator. An operation control method in the oxidation-ditch method, characterized by driving and controlling a state.
流入して、水路に配備した機械的曝気撹拌機による曝気
作用を伴って原水を循環させながら活性汚泥と混合処理
するようにしたオキシデーション・ディッチ法による水
処理装置において、 機械的曝気撹拌機の上流側に呼吸速度計を設置するとと
もに、この機械的曝気撹拌機の下流側に溶存酸素濃度計
を設置して、呼吸速度計の計測値が高い場合には機械的
曝気撹拌機による酸素供給を増大する制御を実施する一
方、呼吸速度計の計測値が低い場合には酸素供給を減少
するような制御を実施し、溶存酸素濃度の計測値と上記
呼吸速度値とから溶存酸素濃度がゼロになる位置を予測
して機械的曝気撹拌機の曝気及び曝気停止状態を駆動制
御することを特徴とするオキシデーション・ディッチ法
における運転制御方法。2. Raw water is allowed to flow into a biological reaction tank consisting of an endless water channel, and the raw water is circulated with the aeration action of a mechanical aeration stirrer installed in the water channel to perform a mixed treatment with activated sludge. In a water treatment device using the oxidation-ditch method, a respiration rate meter is installed upstream of the mechanical aeration stirrer, and a dissolved oxygen concentration meter is installed downstream of the mechanical aeration stirrer. When the measured value of is high, the oxygen supply by the mechanical aeration stirrer is controlled to increase, while when the measured value of the respiration rate meter is low, the oxygen supply is controlled to reduce the dissolved oxygen. Oxidation ditch characterized by predicting the position where the dissolved oxygen concentration becomes zero from the measured value of the concentration and the respiration rate value and drivingly controlling the aeration and aeration stop state of the mechanical aeration mixer Operation control method in.
流入して、水路に配備した機械的曝気撹拌機による曝気
作用を伴って原水を循環させながら活性汚泥と混合処理
するようにしたオキシデーション・ディッチ法による水
処理装置において、 上記生物反応槽内に複数台の機械的曝気撹拌機と呼吸速
度計を設置して、この呼吸速度計の計測値に基づいて、
制御装置により複数台の機械的曝気撹拌機の曝気及び曝
気停止状態を個別に駆動制御することを特徴とするオキ
シデーション・ディッチ法における運転制御方法。3. The raw water is introduced into a biological reaction tank consisting of an endless water channel, and the raw water is circulated with the aeration action of a mechanical aeration stirrer installed in the water channel to perform mixed treatment with activated sludge. In the water treatment device by the oxidation-ditch method, a plurality of mechanical aerators and respiration rate meters are installed in the biological reaction tank, and based on the measured values of this respiration rate meter,
An operation control method in an oxidation ditch method, characterized in that the control device individually drives and controls aeration and aeration stop states of a plurality of mechanical aeration mixers.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7307032A JPH09141289A (en) | 1995-11-27 | 1995-11-27 | Operation control method for oxidation ditch system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7307032A JPH09141289A (en) | 1995-11-27 | 1995-11-27 | Operation control method for oxidation ditch system |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH09141289A true JPH09141289A (en) | 1997-06-03 |
Family
ID=17964222
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP7307032A Pending JPH09141289A (en) | 1995-11-27 | 1995-11-27 | Operation control method for oxidation ditch system |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH09141289A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111410314A (en) * | 2020-04-30 | 2020-07-14 | 中原环保股份有限公司 | Pre-control method and device for denitrification and dephosphorization by improved oxidation ditch process |
-
1995
- 1995-11-27 JP JP7307032A patent/JPH09141289A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111410314A (en) * | 2020-04-30 | 2020-07-14 | 中原环保股份有限公司 | Pre-control method and device for denitrification and dephosphorization by improved oxidation ditch process |
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