JPH0819791A - Nitration method and apparatus - Google Patents
Nitration method and apparatusInfo
- Publication number
- JPH0819791A JPH0819791A JP15498194A JP15498194A JPH0819791A JP H0819791 A JPH0819791 A JP H0819791A JP 15498194 A JP15498194 A JP 15498194A JP 15498194 A JP15498194 A JP 15498194A JP H0819791 A JPH0819791 A JP H0819791A
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- JP
- Japan
- Prior art keywords
- nitrification
- water
- treated
- tank
- nitrifying
- 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.)
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- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、被処理水中の窒素化合
物をプラグフロー型の硝化槽を用いて生物学的に硝化す
る硝化方法および装置に関し、窒素化合物含有排液の生
物学的硝化脱窒法に利用可能な硝化方法および装置に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nitrification method and apparatus for biologically nitrifying nitrogen compounds in water to be treated by using a plug flow type nitrification tank. The present invention relates to a nitrification method and apparatus that can be used in the nitrification method.
【０００２】[0002]
【従来の技術】アンモニア性または有機性窒素化合物を
含む排液を処理する方法として、生物学的硝化脱窒処理
法がある。この方法は活性汚泥の存在下に好気性処理し
て排液中のＣＯＤ、ＢＯＤ成分を分解するとともに、有
機性窒素化合物をアンモニア性窒素とし、その後硝化細
菌が増殖した活性汚泥の存在下に曝気してアンモニア性
窒素（ＮＨ4−Ｎ）を硝化細菌により亜硝酸性または硝
酸性窒素（以下、これらをまとめてＮＯx−Ｎという場
合がある）に硝化（酸化）した後、脱窒細菌が増殖した
活性汚泥の存在下に嫌気状態に維持することにより、亜
硝酸性また硝酸性窒素を窒素ガスに還元して脱窒する方
法である。2. Description of the Related Art As a method for treating an effluent containing an ammoniacal or organic nitrogen compound, there is a biological nitrification denitrification treatment method. This method decomposes COD and BOD components in the effluent by aerobic treatment in the presence of activated sludge, converts organic nitrogen compounds into ammonia nitrogen, and then aerates in the presence of activated sludge in which nitrifying bacteria have proliferated. After nitrifying (oxidizing) ammoniacal nitrogen (NH 4 —N) into nitrite or nitrate nitrogen (hereinafter collectively referred to as NOx-N) by nitrifying bacteria, denitrifying bacteria grow. This is a method of denitrifying by reducing nitrite or nitrate nitrogen to nitrogen gas by maintaining it in an anaerobic state in the presence of the activated sludge.
【０００３】硝化および脱窒の両反応ともｐＨ変化を伴
う反応であるが、特に硝化反応では、１モルのＮＨ4 +が
硝化される際に２モルのＨ+が発生するため、硝化処理
水のｐＨが大幅に低下する。ところが硝化細菌の硝化活
性は図４に示すようにｐＨによって大きく影響を受ける
ため、何らかの手段で硝化槽内のｐＨを硝化細菌の活性
が高い範囲内に制御することが必要である。Both nitrification and denitrification reactions are reactions involving pH changes. Particularly, in the nitrification reaction, 2 mol of H + is generated when 1 mol of NH 4 + is nitrified, so that nitrification-treated water is treated. The pH of is drastically reduced. However, the nitrifying activity of nitrifying bacteria is greatly affected by the pH as shown in FIG. 4, so it is necessary to control the pH in the nitrifying tank within a range where the activity of the nitrifying bacteria is high by some means.
【０００４】ところで硝化におけるｐＨ変化は、被処理
水のＮＨ4 +濃度およびアルカリ度によって決定される。
すなわち、被処理水のアルカリ度がＮＨ4 +濃度と比較し
て十分に大きい場合は、硝化によるｐＨ低下は小さくな
り、逆にアルカリ度がＮＨ4 +濃度と比較して小さい場合
にはｐＨ低下は大きくなる。The pH change in nitrification is determined by the NH 4 + concentration and alkalinity of the water to be treated.
That is, when the alkalinity of the water to be treated is sufficiently higher than the NH 4 + concentration, the pH drop due to nitrification is small, and conversely, when the alkalinity is small compared to the NH 4 + concentration, the pH drop is low. Grows.
【０００５】従来、硝化によるｐＨ低下に対処するため
に、ｐＨ調整剤として水酸化ナトリウム等のアルカリを
添加して、ｐＨを所定値に維持することが行われてお
り、ｐＨ調整剤としては炭酸アルカリの使用も可能とさ
れている（例えば特開昭５６−１１１０９７号、同５５
−１０２４９８号、同５９−１３９９８７号）。しかし
これらの従来例に示されている硝化は完全混合型のもの
であって、プラグフロー型の硝化槽への適用については
示唆されていない。Conventionally, in order to deal with the decrease in pH due to nitrification, an alkali such as sodium hydroxide is added as a pH adjusting agent to maintain the pH at a predetermined value. It is also possible to use an alkali (for example, JP-A-56-111097 and JP-A-55-11550).
-102498, 59-139987). However, the nitrification shown in these conventional examples is of a completely mixed type, and no application to a plug flow type nitrification tank is suggested.
【０００６】活性汚泥法など、完全混合型の浮遊法によ
って硝化を行う場合、被処理水はほぼ完全混合状態とな
っているため、ｐＨ制御は硝化槽液中にｐＨセンサーを
入れ、ｐＨが所定の範囲内になるようにＮａＯＨ等のア
ルカリを添加することにより、容易に制御することがで
きる。When nitrification is carried out by a complete mixing type floating method such as the activated sludge method, the water to be treated is in a nearly completely mixed state. Therefore, a pH sensor is put in the nitrification tank liquid to control the pH. It can be easily controlled by adding an alkali such as NaOH so as to fall within the range.
【０００７】これに対し、硝化細菌が増殖した生物ろ過
層を有する硝化槽を用いて硝化を行う場合は、被処理水
がプラグフローで流れているため、硝化槽全体のｐＨを
所定の範囲に調整することは困難であり、流下方向にｐ
Ｈが低下する。この場合でも硝化槽の前段にｐＨ調整槽
を設け、硝化槽の入口でｐＨ調整を行うことはできる
が、被処理水のアルカリ度がＮＨ4 +濃度と比較して低い
場合は、硝化槽内でのｐＨ低下が大きく、硝化細菌の活
性を高く維持することが困難となり、このため安定して
高い硝化速度（ＮＨ4−Ｎ除去速度）で硝化することは
できない。また、あらかじめ硝化槽内でのｐＨ低下を見
越して、硝化槽入口でのｐＨを高く設定すると、硝化槽
入口のｐＨが高くなりすぎて、硝化細菌の反応が阻害さ
れる場合がある。On the other hand, when nitrification is carried out using a nitrification tank having a biological filtration layer in which nitrifying bacteria have proliferated, the pH of the whole nitrification tank falls within a predetermined range because the water to be treated flows in a plug flow. It is difficult to adjust and p
H decreases. Even in this case, it is possible to install a pH adjustment tank at the front stage of the nitrification tank and adjust the pH at the entrance of the nitrification tank, but if the alkalinity of the water to be treated is lower than the NH 4 + concentration, In this case, it is difficult to maintain the activity of nitrifying bacteria at a high level due to a large decrease in pH, and therefore nitrification cannot be stably performed at a high nitrification rate (NH 4 -N removal rate). Also, if the pH at the entrance of the nitrification tank is set to a high value in anticipation of a decrease in pH in the nitrification tank, the pH at the entrance of the nitrification tank becomes too high, and the reaction of nitrifying bacteria may be hindered.
【０００８】硝化槽内でのｐＨの低下を防止するには、
例えば硝化槽から流出する硝化処理水を再び入口に循環
し、被処理水と循環水とを混合した状態でｐＨ調整する
ことが可能である。この場合、硝化槽入口でのＮＨ4 +濃
度がアルカリ度と比較して小さくなるため、硝化槽内の
ｐＨ低下が小さくなる。理論的には、循環比（被処理水
流量に対する循環水量の割合）を大きくすればするだ
け、被処理水の流れが完全混合状態に近づき、浮遊法と
同様の条件に近づく。しかし、実際には循環ポンプの動
力コストの増加、硝化槽内の液流速が増加することによ
る圧力損失の増加などから、上記のような方法では限界
がある。このためプラグフロー型の硝化槽により硝化す
る場合、低コストで簡単にｐＨ調整することができ、こ
れにより安定して高い硝化速度で硝化することが可能な
硝化方法が要望されている。To prevent the pH from decreasing in the nitrification tank,
For example, it is possible to circulate the nitrification-treated water flowing out from the nitrification tank again to the inlet, and to adjust the pH in a state where the water to be treated and the circulating water are mixed. In this case, since the NH 4 + concentration at the entrance of the nitrification tank becomes smaller than the alkalinity, the pH drop in the nitrification tank becomes small. Theoretically, as the circulation ratio (ratio of the circulating water amount to the treated water flow rate) is increased, the flow of the treated water approaches a completely mixed state, and the conditions similar to those of the floating method are approached. However, in practice, there is a limit in the above method due to an increase in power cost of the circulation pump and an increase in pressure loss due to an increase in liquid flow rate in the nitrification tank. Therefore, when nitrification is performed by a plug flow type nitrification tank, there is a demand for a nitrification method capable of easily adjusting the pH at low cost and thereby stably nitrifying at a high nitrification rate.
【０００９】[0009]
【発明が解決しようとする課題】本発明の目的は、被処
理水中の窒素化合物をプラグフロー型の硝化槽を用いて
生物学的に硝化するに際し、被処理水中のｐＨ、ＮＨ4 +
濃度、有機性窒素化合物含有量またはアルカリ度などが
変動する場合でも、硝化槽内のｐＨを、硝化細菌の硝化
活性が高くなるように低コストで簡単に維持することが
でき、これにより安定して高い硝化速度で硝化すること
が可能な硝化方法および装置を提供することである。An object of the present invention is to provide a, upon biologically nitrifying using nitrification tank plug flow of nitrogen compounds in the water to be treated, in the for-treatment water pH, NH 4 +
Even when the concentration, organic nitrogen compound content or alkalinity changes, the pH in the nitrification tank can be easily maintained at a low cost so that the nitrifying activity of nitrifying bacteria becomes high, and thereby stable To provide a nitrification method and device capable of nitrifying at a high nitrification rate.
【００１０】[0010]
【課題を解決するための手段】本発明は次の硝化方法お
よび装置である。 （１）プラグフロー型の硝化槽に被処理水を通水して生
物学的に硝化する方法において、被処理水をｐＨ６．０
〜９．７の状態で硝化槽に通水して硝化し、硝化処理水
がｐＨ６．０〜９．７を維持するように、被処理水に炭
酸アルカリを添加することを特徴とする硝化方法。 （２）被処理水のｐＨを調整するｐＨ調整槽と、ｐＨ調
整された被処理水を生物学的に硝化するプラグフロー型
の硝化槽と、この硝化槽に導入する被処理水のｐＨを測
定する第一のｐＨ測定装置と、この第一のｐＨ測定装置
の測定値がｐＨ６．０〜９．７になるように、ｐＨ調整
槽にｐＨ調整剤を添加する第一の薬注装置と、硝化処理
水のｐＨを測定する第二のｐＨ測定装置と、この第二の
ｐＨ測定装置の測定値がｐＨ６．０〜９．７を維持する
ように、被処理水に炭酸アルカリを添加する第二の薬注
装置とを備えていることを特徴とする硝化装置。The present invention is the following nitrification method and apparatus. (1) In the method of biologically nitrifying treated water by passing it through a plug flow type nitrification tank, the treated water has a pH of 6.0.
To 9.7, water is passed through the nitrification tank to be nitrified, and an alkali carbonate is added to the water to be treated so that the nitrification-treated water maintains a pH of 6.0 to 9.7. . (2) A pH adjusting tank for adjusting the pH of the water to be treated, a plug flow type nitrification tank for biologically nitrifying the pH-adjusted water to be treated, and a pH of the water to be introduced to the nitrification tank. A first pH measuring device for measuring, and a first chemical injection device for adding a pH adjusting agent to a pH adjusting tank so that the measured value of the first pH measuring device becomes pH 6.0 to 9.7. , A second pH measuring device for measuring the pH of the nitrification-treated water, and an alkali carbonate is added to the water to be treated so that the measurement value of the second pH measuring device maintains the pH of 6.0 to 9.7. A nitrification device comprising a second chemical injection device.
【００１１】本発明の方法および装置において処理の対
象となる被処理水は、アンモニア性窒素または有機性窒
素化合物を含有する液であり、他の不純物を含んでいて
もよい。特にアルカリ度（Ｍ−アルカリ度、以下同じ）
がＮＨ4 +濃度と比較して低く、硝化によりｐＨが大きく
低下する排液、あるいはｐＨ、ＮＨ4 +濃度、有機性窒素
化合物含有量またはアルカリ度が変動する排液などが処
理に適している。このような被処理水は硝化槽に導入す
る前に、活性汚泥を用いた好気性処理により有機物を分
解し、あるいは硝化処理水の循環により脱窒工程を行う
などの処理を行ってもよい。The water to be treated in the method and apparatus of the present invention is a liquid containing ammoniacal nitrogen or organic nitrogen compound and may contain other impurities. Especially alkalinity (M-alkalinity, same below)
Is lower than the NH 4 + concentration and the pH is greatly reduced by nitrification, or the pH, NH 4 + concentration, the organic nitrogen compound content or the alkalinity is changed. . Such water to be treated may be subjected to a treatment such as decomposing organic matter by aerobic treatment using activated sludge or performing a denitrification process by circulating nitrification treated water before introducing it into the nitrification tank.
【００１２】本発明で使用するプラグフロー型の硝化槽
は、硝化細菌が増殖した生物汚泥層を槽内に充填し、こ
の充填層に被処理水をプラグフロー（一方向流）で通水
して、好気性下に接触させて硝化する装置である。生物
汚泥層の形成方法としては、造粒化汚泥を充填するも
の、あるいは充填層に生物汚泥を付着させるものなど、
任意に選択することができる。In the plug flow type nitrification tank used in the present invention, a biological sludge layer in which nitrifying bacteria have grown is filled in the tank, and the water to be treated is passed through this packed layer by plug flow (one-way flow). Then, it is a device for nitrifying by contacting under aerobic conditions. As a method for forming a biological sludge layer, a method of filling the granulated sludge, or a method of attaching the biological sludge to the packed layer,
It can be arbitrarily selected.
【００１３】本発明では、硝化細菌の硝化活性が高くな
るように、被処理水をｐＨ６．０〜９．７、好ましくは
ｐＨ６．５〜９．５の状態でプラグフロー型の硝化槽に
導入して生物学的に硝化する。上記ｐＨ範囲において硝
化細菌の硝化活性が高くなることは図４に示されてい
る。通常の排水は上記ｐＨ範囲に入るので、ｐＨ調整す
ることなく、そのまま硝化槽に導入することができる
が、上記ｐＨ範囲から外れる被処理水の場合は、ｐＨ調
整剤を添加して上記範囲にｐＨ調整して硝化槽に導入す
る。In the present invention, the water to be treated is introduced into a plug flow type nitrification tank at a pH of 6.0 to 9.7, preferably 6.5 to 9.5 so that the nitrifying bacteria have a high nitrifying activity. And nitrify biologically. It is shown in FIG. 4 that the nitrifying activity of nitrifying bacteria is high in the above pH range. Since ordinary waste water falls within the above pH range, it can be introduced into the nitrification tank as it is without pH adjustment. However, in the case of water to be treated which is out of the above pH range, a pH adjusting agent is added to bring it into the above range. Adjust the pH and introduce into the nitrification tank.
【００１４】ｐＨ調整には、水酸化ナトリウム、水酸化
カリウム等のアルカリ；硫酸、塩酸等の酸などが使用で
きるが、後述する炭酸アルカリ以外のｐＨ調整剤を使用
するのが好ましい。ｐＨ調整はｐＨ調整槽に被処理水を
導入し、ここにｐＨ調整剤を添加して行われるが、硝化
槽から流出する硝化処理水をｐＨ調整槽に循環するのが
好ましい。またｐＨ調整は被処理水のｐＨを調整するた
めに、ｐＨ調整槽内のｐＨを測定し、その測定値が上記
範囲となるように、ｐＨ調整剤の添加量を制御して行う
のが一般的であるが、硝化槽の前に脱窒槽等が設けられ
る場合は、硝化槽入口のｐＨを測定しながらｐＨ調整剤
の添加量を制御することも可能である。For adjusting the pH, alkali such as sodium hydroxide and potassium hydroxide; acid such as sulfuric acid and hydrochloric acid can be used, but it is preferable to use a pH adjusting agent other than the alkali carbonate described later. The pH is adjusted by introducing water to be treated into a pH adjusting tank and adding a pH adjusting agent thereto, but it is preferable to circulate the nitrification treated water flowing out from the nitrifying tank to the pH adjusting tank. In addition, the pH adjustment is generally performed by measuring the pH in the pH adjusting tank in order to adjust the pH of the water to be treated and controlling the addition amount of the pH adjusting agent so that the measured value falls within the above range. However, when a denitrification tank or the like is provided before the nitrification tank, it is possible to control the addition amount of the pH adjusting agent while measuring the pH at the entrance of the nitrification tank.
【００１５】また本発明では、硝化処理水がｐＨ６．０
〜９．７、好ましくは６．５〜９．５を維持するように
炭酸アルカリを添加するが、使用する炭酸アルカリとし
ては、炭酸ナトリウム、炭酸カリウム、炭酸ナトリウム
カリウム等のアルカリ金属の炭酸塩；炭酸水素ナトリウ
ム、炭酸水素カリウム等のアルカリ金属の炭酸水素塩な
どがあげられる。これらは一種単独で使用することもで
きるし、二種以上を組合せて使用することもできる。こ
れらの炭酸アルカリはｐＨ緩衝剤としての作用を有し、
硝化により亜硝酸または硝酸が生成してもｐＨ低下を抑
制する作用を有する。Further, in the present invention, the nitrification-treated water has a pH of 6.0.
Alkali carbonate is added so as to maintain ˜9.7, preferably 6.5 to 9.5, and as the alkali carbonate to be used, carbonates of alkali metals such as sodium carbonate, potassium carbonate and sodium potassium carbonate; Examples thereof include hydrogencarbonates of alkali metals such as sodium hydrogencarbonate and potassium hydrogencarbonate. These may be used alone or in combination of two or more. These alkali carbonates have a function as a pH buffer,
Even if nitrous acid or nitric acid is produced by nitrification, it has an action of suppressing a pH decrease.
【００１６】本発明の硝化装置を構成するｐＨ調整槽
は、被処理水を導入し、ｐＨ調整剤を添加して均一に混
合し、ｐＨ調整するように構成されたものである。均一
に混合するために任意の攪拌手段を用いることができ
る。ｐＨ調整槽には硝化槽から硝化処理水を循環して混
合するように構成するのが好ましく、また炭酸アルカリ
もｐＨ調整槽に添加するのが好ましい。The pH adjusting tank constituting the nitrification apparatus of the present invention is configured to introduce water to be treated, add a pH adjusting agent and mix them uniformly to adjust the pH. Any stirring means can be used for uniform mixing. The pH adjusting tank is preferably configured so that nitrification-treated water is circulated and mixed from the nitrification tank, and alkali carbonate is also preferably added to the pH adjusting tank.
【００１７】第一のｐＨ測定装置は硝化槽に導入する被
処理水のｐＨを測定し、その測定値に基づいて、被処理
水にｐＨ調整剤としてアルカリまたは酸を添加し、被処
理水を前記ｐＨに制御するように構成する。The first pH measuring device measures the pH of the water to be treated which is introduced into the nitrification tank, and based on the measured value, alkali or acid is added to the water to be treated as a pH adjuster to treat the water to be treated. It is configured to control the pH.
【００１８】第二のｐＨ測定装置は、硝化槽で硝化した
硝化処理水のｐＨを測定し、その測定値が前記ｐＨ値を
維持するように、第二の薬注装置から被処理水に添加す
る炭酸アルカリの添加量を制御するように構成する。上
記の制御はフィードバック制御であり、硝化処理水のｐ
Ｈが上記下限値を超え、あるいは下限値に近づいたとき
に炭酸アルカリの添加量を増大させ、上限値を超え、あ
るいは上限値に近づいたときに炭酸アルカリの添加量を
減少させるように制御する。The second pH measuring device measures the pH of the nitrification-treated water nitrified in the nitrification tank, and adds it to the water to be treated from the second chemical injection device so that the measured value maintains the pH value. The amount of alkali carbonate to be added is controlled. The above control is feedback control, and the p
When H exceeds the above lower limit or approaches the lower limit, the amount of alkali carbonate added is increased, and when H exceeds the upper limit or approaches the upper limit, the amount of alkali carbonate added is controlled to decrease. .
【００１９】本発明では、上記のようにしてｐＨ調整し
た被処理水を、プラグフロー型の硝化槽に導入し、好気
性下にプラグフローで通水して、硝化細菌により硝化を
行う。硝化槽における硝化はアンモニア性窒素を亜硝酸
または硝酸性窒素に酸化するものであるから、被処理水
中に有機物が存在する場合はあらかじめ活性汚泥処理等
により除去しておくことにより、硝化槽における硝化細
菌を優勢にして効率よく硝化を行うことができる。In the present invention, the water to be treated whose pH has been adjusted as described above is introduced into a plug flow type nitrification tank, and water is aerobically passed through by plug flow to nitrify by nitrifying bacteria. Nitrification in the nitrification tank oxidizes ammoniacal nitrogen to nitrous acid or nitrate nitrogen.Therefore, if organic matter is present in the water to be treated, it should be removed by activated sludge treatment beforehand. Bacteria can be predominant and nitrification can be performed efficiently.
【００２０】本発明では、被処理水のｐＨを前記範囲と
し、しかも硝化処理水のｐＨが前記範囲を維持するよう
に被処理水に炭酸アルカリを添加することにより、硝化
細菌の硝化活性が高くなるｐＨ範囲で硝化が行われ、し
かも被処理水に緩衝性が付与されるため、硝化反応によ
り亜硝酸または硝酸が生成しても緩衝作用によりｐＨの
低下は防止されプラグフローの場合でも効率よく硝化が
行われる。In the present invention, the nitrification activity of nitrifying bacteria is increased by adding the alkali carbonate to the water to be treated so that the pH of the water to be treated is within the above range and the pH of the nitrification treated water is maintained within the above range. Since nitrification is performed in the pH range and the water to be treated is given a buffering property, even if nitrous acid or nitric acid is produced by the nitrification reaction, the buffering action prevents the pH from decreasing and the efficiency is high even in the case of plug flow. Nitrification is performed.
【００２１】本発明の硝化方法および装置は、アンモニ
ア含有液または有機性排液の生物学的硝化脱窒法におけ
る硝化方法および装置として用いられるが、硝化のみを
対象とする場合にも利用可能である。The nitrification method and apparatus of the present invention is used as a nitrification method and apparatus in a biological nitrification denitrification method of an ammonia-containing liquid or an organic waste liquid, but it can also be used when only nitrification is targeted. .
【００２２】生物学的硝化脱窒法として利用する場合
は、予め活性汚泥法等の好気性処理により有機物を分解
すると同時に有機性窒素化合物をアンモニア性窒素に変
換しておくことが好適である。また脱窒槽を硝化槽の前
段に設けて硝化処理水を循環し、この脱窒槽に被処理水
を導入して、脱窒細菌の存在下に嫌気状態に維持するこ
とにより脱窒を行った後、硝化槽に導入して硝化を行う
ことができる。この場合は脱窒槽と硝化槽を１個の槽内
に設けることができ、例えば生物濾過装置の中間に散気
装置を設けて、上部を好気状態に保ち、上向流で被処理
水を通水すると、上部を硝化槽、下部を脱窒槽として一
体化することができる。このような場合でも、前記のよ
うに制御することにより、効率よく硝化を行うことがで
きる。When used as a biological nitrification / denitrification method, it is preferable to previously decompose an organic matter by an aerobic treatment such as an activated sludge method and at the same time convert an organic nitrogen compound into ammoniacal nitrogen. In addition, a denitrification tank was installed in the preceding stage of the nitrification tank to circulate the nitrification-treated water, and the water to be treated was introduced into this denitrification tank, and denitrification was performed by maintaining the anaerobic state in the presence of denitrification bacteria , Can be introduced into a nitrification tank to perform nitrification. In this case, a denitrification tank and a nitrification tank can be provided in one tank. For example, an air diffuser is provided in the middle of the biological filtration device to keep the upper part in an aerobic state and the treated water is treated in an upward flow. When water is passed, the upper part can be integrated with the nitrification tank and the lower part with the denitrification tank. Even in such a case, nitrification can be efficiently performed by controlling as described above.
【００２３】[0023]
【実施例】次に本発明の実施例を図面により説明する。
図１は実施例の硝化装置を示す系統図、図２は硝化槽お
よび脱窒槽が一体化した硝化装置を示す系統図である。
図１において、１はｐＨ調整槽、２は第一のｐＨ測定装
置、３はアルカリ貯槽、４は酸貯槽、５はプラグフロー
型の硝化槽、６は第二のｐＨ測定装置、７は炭酸アルカ
リ貯槽、８は制御装置である。Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 is a system diagram showing a nitrification apparatus of the embodiment, and FIG. 2 is a system diagram showing a nitrification apparatus in which a nitrification tank and a denitrification tank are integrated.
In FIG. 1, 1 is a pH adjusting tank, 2 is a first pH measuring device, 3 is an alkali storage tank, 4 is an acid storage tank, 5 is a plug flow type nitrification tank, 6 is a second pH measuring device, and 7 is carbonic acid. Alkaline storage tank, 8 is a control device.
【００２４】ｐＨ調整槽１には被処理水路１１、アルカ
リ注入路１２、酸注入路１３、連絡路１４、循環路１５
および炭酸アルカリ注入路１６が接続し、槽内液のｐＨ
を測定する第一のｐＨ測定装置２と攪拌機１７が設けら
れている。被処理水路１１には被処理水ポンプ２１、循
環路１５には循環ポンプ２２が設けられている。アルカ
リ注入路１２、酸注入路１３および炭酸アルカリ注入路
１６には、それぞれ薬注ポンプ２３、２４、２５が設け
られている。The pH adjusting tank 1 has a treated water channel 11, an alkali injecting channel 12, an acid injecting channel 13, a connecting channel 14, and a circulating channel 15.
And the alkali carbonate injection path 16 are connected, and the pH of the liquid in the tank is
A first pH measuring device 2 and a stirrer 17 are provided for measuring pH. A treated water pump 21 is provided in the treated water passage 11, and a circulation pump 22 is provided in the circulation passage 15. Chemical injection pumps 23, 24, and 25 are provided in the alkali injection path 12, the acid injection path 13, and the alkali carbonate injection path 16, respectively.
【００２５】硝化槽５の内部には、硝化細菌を有する生
物ろ過層３１が形成されている。生物ろ過層３１の下部
には散気装置３２が設けられて空気供給路３３に接続
し、硝化槽５の上部には硝化処理水のｐＨを測定する第
二のｐＨ測定装置６が設けられている。また硝化槽５の
下部にはｐＨ調整槽１からの連絡路１４、生物ろ過層３
１の上部には処理水路３４およびｐＨ調整槽１への循環
路１５、ならびに硝化槽５の上部には排ガス路３５が接
続している。Inside the nitrification tank 5, a biological filtration layer 31 containing nitrifying bacteria is formed. An air diffuser 32 is provided below the biological filtration layer 31 and connected to the air supply passage 33, and a second pH measuring device 6 for measuring the pH of the nitrification-treated water is provided above the nitrification tank 5. There is. Further, in the lower part of the nitrification tank 5, the communication path 14 from the pH adjusting tank 1 and the biological filtration layer 3 are provided.
A treatment water passage 34 and a circulation passage 15 to the pH adjusting tank 1 are connected to an upper portion of the No. 1 and an exhaust gas passage 35 is connected to an upper portion of the nitrification tank 5.
【００２６】制御装置８は第一のｐＨ測定装置２の測定
ｐＨ信号を入力し、測定値がｐＨ６．０、好ましくは
６．５より低い場合には薬注ポンプ２３に駆動信号を出
力し、測定値がｐＨ９．７、好ましくは９．５より高い
場合には薬注ポンプ２４に駆動信号を出力するように構
成されている。また制御装置８は第二のｐＨ測定装置６
の測定ｐＨ信号を入力し、フィードバック制御により測
定値がｐＨ６．０、好ましくは６．５より低い場合は必
要薬注量を演算して薬注ポンプ２５に駆動信号を出力す
るように構成されている。The control device 8 inputs the measured pH signal of the first pH measuring device 2 and outputs a driving signal to the chemical injection pump 23 when the measured value is lower than pH 6.0, preferably 6.5. It is arranged to output a drive signal to the dosing pump 24 when the measured value is above pH 9.7, preferably above 9.5. Further, the control device 8 is the second pH measuring device 6
When the measured pH signal is input by feedback control and the measured value is lower than pH 6.0, preferably lower than 6.5, the necessary amount of chemical injection is calculated and a drive signal is output to the chemical injection pump 25. There is.
【００２７】アルカリ貯槽３、アルカリ注入路１２、酸
貯槽４、酸注入路１３および薬注ポンプ２３、２４が第
一の薬注装置を構成し、第一のｐＨ測定装置２の測定ｐ
Ｈ値に応じて、制御装置８の制御信号によりアルカリま
たは酸を注入するように構成されている。また炭酸アル
カリ貯槽７、炭酸アルカリ注入路１６および薬注ポンプ
２５が第二の薬注装置を構成し、第二のｐＨ測定装置６
の測定ｐＨ値に応じて、制御装置８の制御信号により炭
酸アルカリを注入するように構成されている。The alkali storage tank 3, the alkali injection passage 12, the acid storage tank 4, the acid injection passage 13 and the chemical injection pumps 23 and 24 constitute the first chemical injection device, and the measurement p of the first pH measuring device 2 is measured.
The control signal of the control device 8 is used to inject an alkali or an acid in accordance with the H value. Further, the alkali carbonate storage tank 7, the alkali carbonate injection passage 16 and the chemical injection pump 25 constitute a second chemical injection device, and the second pH measuring device 6
The control device 8 is configured to inject the alkali carbonate according to the measured pH value.
【００２８】図２において、１０は脱窒硝化槽であっ
て、上部の硝化槽５と下部の脱窒槽９とが一体化した構
造になっている。この脱窒硝化槽１０では、槽内に一体
的に充填された生物ろ過層３１ａ、３１ｂの中間に、空
気供給路３３に接続する散気装置３２が設けられ、散気
装置３２の上部に硝化細菌を含む生物ろ過層３１ａ、下
部に脱窒細菌を含む生物ろ過層３１ｂが形成されてい
る。他の構成は図１と同様である。In FIG. 2, reference numeral 10 denotes a denitrification nitrification tank having a structure in which an upper nitrification tank 5 and a lower denitrification tank 9 are integrated. In the denitrification and nitrification tank 10, an air diffuser 32 connected to the air supply path 33 is provided between the biological filtration layers 31a and 31b that are integrally filled in the tank, and the nitrification is provided above the air diffuser 32. A biological filter layer 31a containing bacteria and a biological filter layer 31b containing denitrifying bacteria are formed below. Other configurations are the same as those in FIG.
【００２９】図１の装置により硝化を行うには、まず被
処理水ポンプ２１を駆動して被処理水路１１から被処理
水をｐＨ調整槽１に導入し、循環ポンプ２２を駆動して
循環路１５から硝化処理水を導入し、攪拌機１７で攪拌
する。そしてｐＨ調整槽１の槽内液のｐＨを第一のｐＨ
測定装置２で測定し、測定ｐＨを制御装置８に入力す
る。この測定ｐＨ値に応じて制御装置８から制御信号を
出力して、薬注ポンプ２３または２４を駆動し、槽内液
がｐＨ６．５〜９．５となるように、アルカリ貯槽３ま
たは酸貯槽４中のアルカリまたは酸を、アルカリ注入路
１２または酸注入路１３を通して注入する。In order to carry out nitrification by the apparatus shown in FIG. 1, first, the treated water pump 21 is driven to introduce the treated water from the treated water passage 11 into the pH adjusting tank 1, and the circulation pump 22 is driven to drive the circulation passage. Nitrification-treated water is introduced from 15, and stirred by a stirrer 17. The pH of the liquid in the pH adjusting tank 1 is set to the first pH.
The measurement is performed by the measuring device 2, and the measured pH is input to the control device 8. A control signal is output from the control device 8 in accordance with the measured pH value to drive the chemical injection pump 23 or 24 so that the liquid in the tank has a pH of 6.5 to 9.5 and the alkali storage tank 3 or the acid storage tank. The alkali or acid in 4 is injected through the alkali injection path 12 or the acid injection path 13.
【００３０】上記ｐＨに調整した被処理水（槽内液）は
連絡路１４を通して硝化槽５に導入する。ここでは、空
気供給路３３から供給する空気を散気装置３２で散気し
た状態で、被処理水を生物ろ過層３１中を上向流で通水
し、硝化細菌の作用により、被処理水中のＮＨ4−Ｎを
ＮＯx−Ｎに生物学的に硝化する。被処理水中に有機性
窒素化合物が含有されている場合は、この有機物性窒素
化合物はＢＯＤ分解細菌の作用によりＮＨ4−Ｎに分解
され、さらに硝化細菌の作用によりＮＯx−Ｎに硝化さ
れる。The water to be treated (solution in the tank) adjusted to the above pH is introduced into the nitrification tank 5 through the communication passage 14. Here, in the state where the air supplied from the air supply path 33 is diffused by the diffuser 32, the water to be treated is passed through the biological filtration layer 31 in an upward flow, and the water to be treated is treated by the action of nitrifying bacteria. Biologically nitrifying the NH 4 —N of the above into NOx —N. When the water to be treated contains an organic nitrogen compound, the organic nitrogen compound is decomposed into NH 4 —N by the action of BOD-decomposing bacteria, and further nitrified into NOx-N by the action of nitrifying bacteria.
【００３１】硝化処理水の一部は、循環路１５から循環
ポンプ２２によりｐＨ調整槽１に循環する。残部は処理
水として処理水路３４から取出す。硝化処理水の一部を
循環して被処理水と混合することにより、硝化槽５入口
におけるＮＨ4 +濃度がアルカリ度と比較して小さくなる
ため、ｐＨの低下を小さくすることができ、これにより
循環しない場合に比べて炭酸アルカリの添加量を少なく
することができる。なお、硝化処理水の循環は必ずしも
必要ではなく、場合によっては省略することもできる。A part of the nitrification-treated water is circulated from the circulation path 15 to the pH adjusting tank 1 by the circulation pump 22. The rest is taken out from the treated water passage 34 as treated water. By circulating a part of the nitrification-treated water and mixing it with the water to be treated, the NH 4 + concentration at the inlet of the nitrification tank 5 becomes smaller than the alkalinity, so that the decrease in pH can be reduced. Thus, the amount of alkali carbonate added can be reduced as compared with the case where no circulation is performed. The circulation of the nitrification-treated water is not always necessary and may be omitted in some cases.
【００３２】上記の処理において、硝化処理水のｐＨを
第二のｐＨ測定装置６により測定し、測定ｐＨ値を制御
装置８に入力する。制御装置８ではこの測定ｐＨ値によ
り必要炭酸アルカリ量を演算して、制御信号を出力し、
薬注ポンプ２５を駆動する。これにより硝化処理水のｐ
Ｈが前記範囲となるように、炭酸アルカリ貯槽７中の炭
酸アルカリが炭酸アルカリ注入路１６を通してｐＨ調整
槽１に添加される。この場合、炭酸アルカリの添加信号
とｐＨ測定位置とが離れているので、フィードバック制
御により必要添加量を演算して制御するのが好ましい。
炭酸アルカリの添加および硝化処理水の循環によりｐＨ
調整槽１内の槽内液のｐＨが所定のｐＨの範囲外になる
場合には、制御装置８の判定によりアルカリまたは酸を
添加してｐＨ調整が行われる。In the above treatment, the pH of the nitrification-treated water is measured by the second pH measuring device 6, and the measured pH value is input to the control device 8. The controller 8 calculates the necessary amount of alkali carbonate based on the measured pH value and outputs a control signal,
The chemical injection pump 25 is driven. As a result, p
The alkali carbonate in the alkali carbonate storage tank 7 is added to the pH adjusting tank 1 through the alkali carbonate injection passage 16 so that H falls within the above range. In this case, since the alkali carbonate addition signal and the pH measurement position are apart from each other, it is preferable to calculate and control the required addition amount by feedback control.
PH by adding alkali carbonate and circulating nitrifying water
When the pH of the in-tank liquid in the adjusting tank 1 is out of the predetermined pH range, the pH is adjusted by adding an alkali or an acid according to the judgment of the controller 8.
【００３３】被処理水の水質に応じて、ｐＨ調整剤、炭
酸アルカリとして表１のような使い分けが好ましい。It is preferable to properly use the pH adjuster and the alkali carbonate as shown in Table 1 according to the quality of the water to be treated.
【表１】 表１において、ＮａＯＨ、Ｈ2ＳＯ4はそれぞれ炭酸アル
カリ以外の他のアルカリまたは酸でもよく、それぞれア
ルカリ貯槽３または酸貯槽４から注入される。[Table 1] In Table 1, NaOH and H 2 SO 4 may be alkalis or acids other than alkali carbonate, respectively, and are injected from the alkali storage tank 3 or the acid storage tank 4, respectively.
【００３４】以上のような操作を繰返して行うことによ
り、硝化槽５内でのｐＨの低下を防止して、高い硝化速
度で安定して硝化を行うことができる。また被処理水の
ｐＨ、ＮＨ4 +濃度、有機性窒素化合物含有量またはアル
カリ度などが変動しても、それに応じてｐＨ調整がなさ
れるので、高い硝化速度を維持でき、しかも注入する薬
品の量を必要最低限に抑えることができる。By repeating the above operation, it is possible to prevent the pH from decreasing in the nitrification tank 5 and to perform nitrification stably at a high nitrification rate. Further, even if the pH of the water to be treated, the NH 4 + concentration, the organic nitrogen compound content or the alkalinity changes, the pH is adjusted accordingly, so that a high nitrification rate can be maintained, and the chemicals to be injected can be maintained. The amount can be kept to the minimum necessary.
【００３５】図２の装置においても、図１の場合と同様
にして操作することができる。この場合、脱窒硝化槽１
０の内部は、散気装置３２より下が嫌気状態となるの
で、生物ろ過層は下部に脱窒細菌を有する生物ろ過層３
１ｂ、および上部に硝化細菌を有する生物ろ過層３１ａ
が形成され、１つの槽内で脱窒および硝化が行われる。
なお図２の場合、脱窒槽９におけるｐＨ変化は無視でき
る程度であるため、第一のｐＨ測定装置２をｐＨ調整槽
１に設けているが、硝化槽５の被処理水のｐＨを測定す
るためには、第一のｐＨ測定装置２を生物ろ過層３１ａ
と３１ｂの間に設けることもできる。The apparatus shown in FIG. 2 can be operated in the same manner as in the case shown in FIG. In this case, denitrification nitrification tank 1
Since the inside of 0 is in an anaerobic state below the aeration device 32, the biological filtration layer is a biological filtration layer 3 having denitrifying bacteria at the bottom.
1b, and biological filtration layer 31a having nitrifying bacteria on the top
Are formed, and denitrification and nitrification are performed in one tank.
In the case of FIG. 2, since the pH change in the denitrification tank 9 is negligible, the first pH measuring device 2 is provided in the pH adjusting tank 1, but the pH of the water to be treated in the nitrification tank 5 is measured. In order to do so, the first pH measuring device 2 is attached to the biological filtration layer 31a.
And 31b may be provided.
【００３６】実施例１、比較例１ ＮＨ4 +＝５０ｍｇ−Ｎ／ｌ、ＢＯＤ＝２〜５ｍｇ／ｌ、
Ｍ−アルカリ度＝７０〜１６０ｍｇ−ＣａＣＯ3／ｌ、
ｐＨ＝６．６〜７．３（ただしＮＨ4 +濃度は５０ｍｇ−
Ｎ／ｌになるように人為的に制御したが、他は上記値の
範囲内で変動した）の工場廃水を被処理水として、図１
の装置により硝化を行った。硝化槽５内部には、直径
３．５ｍｍのポリスチレン性の浮上性ろ材に硝化細菌を
含む微生物汚泥を付着させて生物ろ過層３１を形成し
た。炭酸アルカリとしては炭酸ナトリウムを用いた。ｐ
Ｈ調整剤としては、水酸化ナトリウムおよび硫酸を用い
た。循環路１５からの循環量は被処理水路１１からの被
処理水量と同量とした。Example 1, Comparative Example 1 NH 4 + = 50 mg-N / l, BOD = 2-5 mg / l,
M- alkalinity = 70~160mg-CaCO 3 / l,
pH = 6.6 to 7.3 (NH 4 + concentration is 50 mg-
It was artificially controlled to be N / l, but other values varied within the range of the above values).
Nitrification was carried out by the above apparatus. Inside the nitrification tank 5, a microbial sludge containing nitrifying bacteria was attached to a polystyrene-based floating filter medium having a diameter of 3.5 mm to form a biological filtration layer 31. Sodium carbonate was used as the alkali carbonate. p
As the H regulator, sodium hydroxide and sulfuric acid were used. The circulation amount from the circulation passage 15 was the same as the treatment water amount from the treatment water passage 11.
【００３７】硝化の操作は次のようにして行った。すな
わち、生物ろ過層３１が定常になった後、最初の１か月
間は炭酸ナトリウムの添加は行わず、水酸化ナトリウム
または硫酸を添加してｐＨ調整槽１内をｐＨ８．５に制
御して硝化を行った（比較例１）。次の１か月間は、ｐ
Ｈ調整槽１内がｐＨ８．５になるように水酸化ナトリウ
ムまたは硫酸を添加し、さらに硝化処理水がｐＨ６．５
になるように炭酸ナトリウムを添加して制御を行った
（実施例１）。その他の条件は試験期間中全く同じと
し、硝化負荷１．５ｋｇ−Ｎ／ｍ3・ｄａｙで運転し
た。試験期間中の硝化槽５出口の硝化処理水のｐＨおよ
びＮＨ4 +の除去率を図３に示す。The operation of nitrification was performed as follows. That is, after the biological filtration layer 31 becomes steady, sodium carbonate is not added for the first month, but sodium hydroxide or sulfuric acid is added to control the pH in the pH adjusting tank 1 to 8.5 and nitrification. Was performed (Comparative Example 1). P for the next month
Sodium hydroxide or sulfuric acid was added so that the inside of the H adjusting tank 1 had a pH of 8.5, and the nitrification-treated water had a pH of 6.5.
Sodium carbonate was added so as to achieve the control (Example 1). The other conditions were exactly the same during the test period, and the system was operated at a nitrification load of 1.5 kg-N / m 3 · day. The pH of the nitrification-treated water at the outlet of the nitrification tank 5 and the NH 4 + removal rate during the test period are shown in FIG.
【００３８】図３からわかるように、被処理水のアルカ
リ度の変動によって最初の１か月間（比較例となる試験
期間）は硝化処理水のｐＨが変動し、それに伴いＮＨ4 +
の除去率も変動している。それに対して、硝化処理水の
ｐＨが６．５になるように炭酸ナトリウムを添加した次
の１か月間（実施例の試験期間）は、ＮＨ4 +の除去率が
安定した値を示しており、しかも平均で除去率が１７％
増加した。As can be seen from FIG. 3, the pH of the nitrification-treated water fluctuates during the first month (test period as a comparative example) due to the fluctuation of the alkalinity of the water to be treated, and accordingly NH 4 +.
The removal rate of is also fluctuating. On the other hand, the removal rate of NH 4 + shows a stable value during the next month (the test period of the example) in which sodium carbonate was added so that the pH of the nitrification-treated water was 6.5. Moreover, the removal rate is 17% on average
Increased.
【００３９】[0039]
【発明の効果】本発明の硝化方法は、硝化処理水のｐＨ
が特定の範囲となるように、被処理水に炭酸アルカリを
添加して硝化を行うので、被処理水のｐＨ、ＮＨ4 +濃
度、有機性窒素化合物含有量またはアルカリ度などが変
動する場合でも、低コストかつ簡単な操作で、硝化槽内
のｐＨを硝化細菌の硝化活性が高くなる範囲に維持する
ことができ、これにより安定して高い硝化速度で硝化を
行うことができる。The nitrification method of the present invention is characterized by the pH of nitrification-treated water.
Since alkali carbonate is added to the water to be treated to nitrify it so that it falls within a specific range, even if the pH, NH 4 + concentration, organic nitrogen compound content or alkalinity of the water to be treated changes. The pH in the nitrification tank can be maintained in a range where the nitrifying activity of nitrifying bacteria is high by low cost and simple operation, and thus nitrification can be stably performed at a high nitrification rate.
【００４０】本発明の硝化装置は、硝化処理水のｐＨを
測定するｐＨ測定装置、およびこの装置の測定ｐＨ値に
応じて、硝化処理水のｐＨが特定の範囲になるように、
被処理水に炭酸アルカリを添加する薬注装置を備えてい
るので、被処理水のｐＨ、ＮＨ4 +濃度、有機性窒素化合
物含有量またはアルカリ度などが変動する場合でも、簡
単な構造の装置を用いかつ簡単な操作により、硝化槽内
のｐＨを硝化細菌の硝化活性が高くなる範囲に維持する
ことができ、これにより安定して高い硝化速度で硝化を
行うことができる。The nitrification apparatus of the present invention is a pH measuring apparatus for measuring the pH of nitrification-treated water, and the pH of the nitrification-treated water falls within a specific range depending on the pH value measured by this apparatus.
Since it is equipped with a chemical injection device that adds alkali carbonate to the water to be treated, it has a simple structure even when the pH, NH 4 + concentration, organic nitrogen compound content or alkalinity of the water to be treated fluctuates. The pH in the nitrification tank can be maintained in a range in which the nitrifying activity of nitrifying bacteria is high by using the above and a simple operation, whereby stable nitrification can be performed at a high nitrification rate.
【図１】本発明の実施例の硝化装置を示す系統図であ
る。FIG. 1 is a system diagram showing a nitrification apparatus according to an embodiment of the present invention.
【図２】本発明の他の実施例の硝化装置を示す系統図で
ある。FIG. 2 is a system diagram showing a nitrification apparatus according to another embodiment of the present invention.
【図３】実施例１および比較例１の試験結果を示すグラ
フである。FIG. 3 is a graph showing test results of Example 1 and Comparative Example 1.
【図４】硝化細菌の硝化活性とｐＨとの関係を示すグラ
フである。FIG. 4 is a graph showing the relationship between nitrifying activity of nitrifying bacteria and pH.
１ ｐＨ調整槽 ２ 第一のｐＨ測定装置 ３ アルカリ貯槽 ４ 酸貯槽 ５ 硝化槽 ６ 第二のｐＨ測定装置 ７ 炭酸アルカリ貯槽 ８ 制御装置 ９ 脱窒槽 １０ 脱窒硝化槽 １１ 被処理水路 １２ アルカリ注入路 １３ 酸注入路 １４ 連絡路 １５ 循環路 １６ 炭酸アルカリ注入路 １７ 攪拌機 ２１ 被処理水ポンプ ２２ 循環ポンプ ２３、２４、２５ 薬注ポンプ ３１、３１ａ、３１ｂ 生物ろ過層 ３２ 散気装置 ３３ 空気供給路 ３４ 処理水路 ３５ 排ガス路 1 pH adjusting tank 2 First pH measuring device 3 Alkaline storage tank 4 Acid storage tank 5 Nitrification tank 6 Second pH measuring device 7 Alkali carbonate storage tank 8 Control device 9 Denitrification tank 10 Denitrification nitrification tank 11 Treated water channel 12 Alkali injection channel 13 Acid injection path 14 Connection path 15 Circulation path 16 Alkali carbonate injection path 17 Stirrer 21 Treated water pump 22 Circulation pump 23, 24, 25 Chemical injection pump 31, 31a, 31b Biofiltration layer 32 Air diffuser 33 Air supply path 34 Treated water channel 35 Exhaust gas channel
Claims (2)
水して生物学的に硝化する方法において、被処理水をｐ
Ｈ６．０〜９．７の状態で硝化槽に通水して硝化し、硝
化処理水がｐＨ６．０〜９．７を維持するように、被処
理水に炭酸アルカリを添加することを特徴とする硝化方
法。1. A method for biologically nitrifying water to be treated by passing the water to be treated through a plug flow type nitrification tank.
It is characterized in that an alkali carbonate is added to the water to be treated so that the nitrification-treated water maintains a pH of 6.0 to 9.7 by passing water through the nitrification tank in a state of H 6.0 to 9.7. Nitrification method.
と、 ｐＨ調整された被処理水を生物学的に硝化するプラグフ
ロー型の硝化槽と、 この硝化槽に導入する被処理水のｐＨを測定する第一の
ｐＨ測定装置と、 この第一のｐＨ測定装置の測定値がｐＨ６．０〜９．７
になるように、ｐＨ調整槽にｐＨ調整剤を添加する第一
の薬注装置と、 硝化処理水のｐＨを測定する第二のｐＨ測定装置と、 この第二のｐＨ測定装置の測定値がｐＨ６．０〜９．７
を維持するように、被処理水に炭酸アルカリを添加する
第二の薬注装置とを備えていることを特徴とする硝化装
置。2. A pH adjusting tank for adjusting the pH of the water to be treated, a plug flow type nitrifying tank for biologically nitrifying the pH-adjusted water, and the water to be introduced into the nitrifying tank. A first pH measuring device for measuring pH, and a measurement value of the first pH measuring device is pH 6.0 to 9.7.
The first chemical injection device for adding a pH adjusting agent to the pH adjusting tank, the second pH measuring device for measuring the pH of the nitrification-treated water, and the measured value of the second pH measuring device are pH 6.0 to 9.7
And a second chemical injection device for adding an alkali carbonate to the water to be treated so that the nitrification device is maintained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15498194A JP3396959B2 (en) | 1994-07-06 | 1994-07-06 | Nitrification method and apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15498194A JP3396959B2 (en) | 1994-07-06 | 1994-07-06 | Nitrification method and apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0819791A true JPH0819791A (en) | 1996-01-23 |
| JP3396959B2 JP3396959B2 (en) | 2003-04-14 |
Family
ID=15596107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15498194A Expired - Fee Related JP3396959B2 (en) | 1994-07-06 | 1994-07-06 | Nitrification method and apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3396959B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011519309A (en) * | 2008-04-28 | 2011-07-07 | ポステック アカデミー−インダストリー ファンデーション | Biofilm reactor with helical structure and water treatment apparatus using the same |
| JP5936774B2 (en) * | 2013-06-13 | 2016-06-22 | 三菱重工メカトロシステムズ株式会社 | Waste water treatment method and waste water treatment system |
-
1994
- 1994-07-06 JP JP15498194A patent/JP3396959B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011519309A (en) * | 2008-04-28 | 2011-07-07 | ポステック アカデミー−インダストリー ファンデーション | Biofilm reactor with helical structure and water treatment apparatus using the same |
| JP5936774B2 (en) * | 2013-06-13 | 2016-06-22 | 三菱重工メカトロシステムズ株式会社 | Waste water treatment method and waste water treatment system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3396959B2 (en) | 2003-04-14 |
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