JP2000325989A - Biological denitrification treatment method - Google Patents
Biological denitrification treatment methodInfo
- Publication number
- JP2000325989A JP2000325989A JP14157099A JP14157099A JP2000325989A JP 2000325989 A JP2000325989 A JP 2000325989A JP 14157099 A JP14157099 A JP 14157099A JP 14157099 A JP14157099 A JP 14157099A JP 2000325989 A JP2000325989 A JP 2000325989A
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- Japan
- Prior art keywords
- nitrogen
- methanol
- amt
- hydrogen donor
- nitrogen load
- Prior art date
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Classifications
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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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E50/00—Technologies for the production of fuel of non-fossil origin
- Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel
Landscapes
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は硝酸性窒素を含む窒
素含有排水に水素供与体を添加して生物脱窒処理する方
法に係り、特に、排水の窒素濃度や水量が大幅に変動す
る場合であっても、水素供与体添加量の過不足を生じる
ことなく、脱窒に必要な最少量の水素供与体の添加量で
良好な水質の処理水を安定かつ効率的に得ることができ
る生物脱窒処理方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for biological denitrification by adding a hydrogen donor to a nitrogen-containing wastewater containing nitrate nitrogen, and particularly to a method in which the nitrogen concentration and the amount of water in the wastewater fluctuate greatly. Even if there is no excess or deficiency in the amount of hydrogen donor to be added, a biological dewatering system that can stably and efficiently obtain treated water of good water quality with the minimum amount of hydrogen donor required for denitrification. It relates to a nitriding treatment method.
【０００２】[0002]
【従来の技術】従来、ステンレス製造工程から排出され
る硝酸含有洗浄排水の処理には、脱窒反応槽と再曝気槽
を組み込んだ生物脱窒処理法が一般的に採用されてい
る。この洗浄排水の含有不純物は硝酸が主体であるた
め、生物脱窒反応時に脱窒用基質として脱窒反応量に見
合う量の水素供与体（一般的にはメタノール）を脱窒反
応槽に投入する必要がある。2. Description of the Related Art Conventionally, a biological denitrification treatment method incorporating a denitrification reaction tank and a re-aeration tank is generally employed for treating cleaning wastewater containing nitric acid discharged from a stainless steel manufacturing process. Since the impurities contained in the washing wastewater are mainly nitric acid, an amount of hydrogen donor (generally methanol) corresponding to the amount of the denitrification reaction is introduced into the denitrification reaction tank as a substrate for denitrification during the biological denitrification reaction. There is a need.
【０００３】即ち、脱窒反応槽に投入される水素供与体
量が不足する場合には、脱窒反応が不十分となり、脱窒
反応槽内で未分解の窒素が残留し、結果的に処理水の窒
素濃度が低下し得ない。逆に、過剰な水素供与体を投入
した場合には、脱窒反応は十分に進行するが、脱窒反応
槽で使用されずに残留した多量の水素供与体が再曝気槽
に流入し、再曝気槽内の溶存酸素（ＤＯ）の減少を引き
起こし、結果的には処理水の悪化を生じる。また、必要
以上に汚泥が増殖し、余剰汚泥量の増加につながる。That is, when the amount of the hydrogen donor supplied to the denitrification reaction tank is insufficient, the denitrification reaction becomes insufficient, and undecomposed nitrogen remains in the denitrification reaction tank. The nitrogen concentration of the water cannot be reduced. Conversely, when an excessive amount of hydrogen donor is charged, the denitrification reaction proceeds sufficiently, but a large amount of hydrogen donor that has not been used in the denitrification reaction tank flows into the re-aeration tank and is re-aerated. This causes a decrease in dissolved oxygen (DO) in the aeration tank, resulting in deterioration of the treated water. In addition, sludge multiplies more than necessary, leading to an increase in the amount of surplus sludge.
【０００４】しかし、この硝酸含有洗浄排水は、これが
排出されるステンレス製造工程の作業内容の変更や製造
品目により、その濃度、水量が大幅に変動する。従っ
て、大容量の原水調整槽や原水貯留槽が無い場合は、洗
浄排水の濃度ないし水量の変動に伴い、脱窒反応槽内の
窒素負荷量は大幅に変動することとなるため、水素供与
体の投入量の過不足に陥り易い。[0004] However, the concentration and amount of the nitric acid-containing washing wastewater fluctuate greatly depending on the change in the work content of the stainless steel manufacturing process from which the wastewater is discharged and on the items to be manufactured. Therefore, if there is no large-capacity raw water adjustment tank or raw water storage tank, the nitrogen load in the denitrification reaction tank will fluctuate significantly with the fluctuation of the concentration or amount of washing wastewater. It is easy to fall into excess or deficiency in the input amount.
【０００５】従来、ステンレス製造工程から排出される
硝酸含有洗浄排水の生物脱窒処理においては、水素供与
体添加量を適正化するための有効な指標が提供されてい
ないことから、処理水の残留窒素量を低減することを重
要視して、水素供与体が不足した場合の未分解窒素の残
留を防止して窒素濃度の低い処理水を安定に得るべく、
過剰量の水素供与体を添加しているのが実状である。Conventionally, in the biological denitrification treatment of nitric acid-containing washing wastewater discharged from a stainless steel production process, no effective index for optimizing the amount of added hydrogen donor has been provided. With an emphasis on reducing the amount of nitrogen, in order to prevent the remaining of undecomposed nitrogen when the hydrogen donor is insufficient, to obtain a stable treatment water with a low nitrogen concentration,
In fact, an excess amount of hydrogen donor is added.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、このよ
うに過剰量の水素供与体を添加する方法では、 水素供与体の添加量が多くなり、結果として運転コ
スト、維持管理コスト等の全体の処理コストが高騰す
る。 再曝気槽でのＤＯ不足により、処理水中の窒素以外
のＢＯＤやＣＯＤが増え、処理水水質が悪化する。 再曝気槽のＤＯを増加するために曝気量を増加する
と曝気のためのコストが嵩み、また、ＤＯ濃度の管理も
煩雑となる。 余剰汚泥の発生量が増大する。 といった問題を生じる上に、過剰量の水素供与体を添加
している場合であっても、硝酸含有洗浄排水の窒素濃度
や水量が大幅に増大すると処理水中に窒素が残留する恐
れもあった。However, in the method of adding an excessive amount of the hydrogen donor, the amount of the hydrogen donor to be added increases, and as a result, the overall processing cost such as the operation cost and the maintenance and management cost is increased. Soars. Due to the lack of DO in the re-aeration tank, BOD and COD other than nitrogen in the treated water increase, and the quality of the treated water deteriorates. If the amount of aeration is increased in order to increase the DO of the re-aeration tank, the cost for aeration increases, and the management of the DO concentration becomes complicated. The amount of excess sludge generated increases. In addition to the above problem, even when an excessive amount of hydrogen donor is added, nitrogen may remain in the treated water if the nitrogen concentration or the amount of water in the nitric acid-containing washing wastewater is significantly increased.
【０００７】本発明は、上記従来の問題点を解決し、硝
酸性窒素を含む窒素含有排水に水素供与体を添加して生
物脱窒処理するに当り、排水の窒素濃度や水量が大幅に
変動する場合であっても、水素供与体の過剰添加を行う
ことなく、脱窒に必要な最少量の水素供与体の添加量で
良好な水質の処理水を安定かつ効率的に得ることができ
る生物脱窒処理方法を提供することを目的とする。[0007] The present invention solves the above-mentioned conventional problems, and when adding a hydrogen donor to a nitrogen-containing wastewater containing nitrate nitrogen to carry out a biological denitrification treatment, the nitrogen concentration and water amount of the wastewater vary greatly. Even in the case of performing the treatment, it is possible to stably and efficiently obtain treated water having good water quality with the minimum amount of the hydrogen donor necessary for denitrification without excessive addition of the hydrogen donor. An object of the present invention is to provide a denitrification treatment method.
【０００８】[0008]
【課題を解決するための手段】本発明の生物脱窒処理方
法は、硝酸性窒素を含む窒素含有排水に水素供与体を添
加して脱窒反応槽にて生物脱窒処理する方法において、
該脱窒反応槽の窒素負荷量に応じて、該窒素負荷量に対
する前記水素供与体の添加比率、即ち、水素供与体量／
窒素負荷量を増減することを特徴とする。Means for Solving the Problems The biological denitrification method of the present invention is a method for biological denitrification in a denitrification reactor by adding a hydrogen donor to a nitrogen-containing wastewater containing nitrate nitrogen.
Depending on the nitrogen load of the denitrification reactor, the addition ratio of the hydrogen donor to the nitrogen load, that is, the amount of the hydrogen donor /
It is characterized by increasing or decreasing the nitrogen load.
【０００９】硝酸性窒素の脱窒反応は下式で表される。[0009] The denitrification reaction of nitrate nitrogen is represented by the following formula.
【００１０】ＮＯ3＋５Ｈ→１／２Ｎ2＋２Ｈ2Ｏ＋ＯＨ 硝酸を還元する水素供与体として一般的にはメタノール
が用いられており、その脱窒反応は下式で表される。NO 3 + 5H → １ ／ N 2 + 2H 2 O + OH Methanol is generally used as a hydrogen donor for reducing nitric acid, and its denitrification reaction is represented by the following formula.
【００１１】ＮＯ3＋５／６ＣＨ3ＯＨ→１／２Ｎ2＋５
／６ＣＯ2＋７／６Ｈ2Ｏ＋ＯＨ 即ち、６モルの硝酸性窒素を脱窒するには５モルのメタ
ノールが必要とされ、従って、１ｋｇの窒素の除去に必
要なメタノール量は１．９ｋｇとなる。NO 3 +5/6 CH 3 OH → 1 / 2N 2 +5
/ 6CO 2 + 7 / 6H 2 O + OH That is, to denitrify 6 moles of nitrate nitrogen, 5 moles of methanol are required, and therefore the amount of methanol required to remove 1 kg of nitrogen is 1.9 kg.
【００１２】実際には脱窒汚泥の増殖に必要とされる炭
素量、窒素量が加味されるため、１ｋｇの窒素の除去に
必要なメタノール量（以下「メタノール係数」と記
す。）は２〜２．３ｋｇとなる。In practice, the amounts of carbon and nitrogen required for multiplication of denitrification sludge are taken into account, so that the amount of methanol required to remove 1 kg of nitrogen (hereinafter referred to as "methanol coefficient") is 2 to 2. 2.3 kg.
【００１３】従って、窒素負荷量に予め設定したメタノ
ール係数を乗じ、図１（ｃ）に示す如くメタノール添加
量を設定することにより、窒素負荷量の変動に対応した
メタノールの投入が可能となると考えられる。Therefore, by multiplying the nitrogen load by a preset methanol coefficient and setting the amount of methanol to be added as shown in FIG. 1 (c), it is considered that the introduction of methanol corresponding to the fluctuation of the nitrogen load becomes possible. Can be
【００１４】しかし、これら反応式上から求めた窒素除
去に必要なメタノール量は、一定値ではなく、脱窒汚泥
の活性や窒素負荷量により変化し、窒素負荷量が極めて
少ない場合では、メタノールの添加なしで、脱窒汚泥の
みの内生呼吸の過程でも脱窒は生じている。この現象は
内生脱窒と呼ばれている。通常、脱窒汚泥の活性が高
く、また窒素負荷量が多い場合は、高いメタノール係数
となり、脱窒汚泥の活性が低く、窒素負荷量が少ない場
合は、低いメタノール係数になる。However, the amount of methanol required for nitrogen removal obtained from these reaction formulas is not a fixed value but varies depending on the activity of the denitrification sludge and the nitrogen load. Without addition, denitrification occurs even in the process of endogenous respiration of only denitrification sludge. This phenomenon is called endogenous denitrification. Usually, when the activity of the denitrification sludge is high and the nitrogen load is large, the methanol coefficient becomes high, and when the activity of the denitrification sludge is low and the nitrogen load is small, the methanol coefficient becomes low.
【００１５】従って、脱窒反応槽に一定の窒素濃度及び
一定水量の排水が流入し、窒素負荷量一定で運転されて
いる場合は、その条件に最適なメタノール係数で投入メ
タノール量を設定することが可能である。しかし、前述
したステンレス製造工程の洗浄排水等では、窒素負荷量
が大幅に変動するため、一定のメタノール係数でメタノ
ールの投入制御を行った場合、高負荷条件ではメタノー
ル不足となり、逆に低負荷条件ではメタノール過剰とな
ってしまう。Therefore, when wastewater with a fixed nitrogen concentration and a fixed amount of water flows into the denitrification reaction tank and the system is operated with a fixed nitrogen load, the amount of methanol to be charged should be set at an optimum methanol coefficient for the condition. Is possible. However, in the washing and drainage of the stainless steel manufacturing process described above, the nitrogen load fluctuates greatly.Therefore, when the methanol injection control is performed with a constant methanol coefficient, methanol shortage occurs under high load conditions, and conversely under low load conditions. Then, there will be excess methanol.
【００１６】本発明では、脱窒反応槽の窒素負荷量に応
じて水素供与体の添加量ではなく、窒素負荷量に対する
水素供与体の添加比率を増減するため、上述のような不
具合は防止され、必要最低限の水素供与体の添加量で良
好な水質の処理水を安定かつ効率的に得ることができ
る。In the present invention, the above-mentioned disadvantages are prevented because the ratio of the hydrogen donor to the nitrogen load is increased or decreased instead of the amount of the hydrogen donor added according to the nitrogen load of the denitrification reactor. In addition, it is possible to stably and efficiently obtain treated water having good water quality with a minimum necessary amount of added hydrogen donor.
【００１７】なお、本明細書では、水素供与体としてメ
タノールを例示して説明しているが、本発明において、
添加する水素供与体としてはメタノールに何ら限定され
ず、エタノール、酢酸等の従来の生物脱窒処理で用いら
れる水素供与体であればいずれも適用可能である。この
ような水素供与体は、脱窒反応槽に直接添加しても良
く、また、原水である窒素含有排水の流入配管に注入し
て原水と共に脱窒反応槽に導入しても良い。In this specification, methanol is described as an example of a hydrogen donor.
The hydrogen donor to be added is not limited to methanol at all, and any hydrogen donor used in conventional biological denitrification such as ethanol and acetic acid can be applied. Such a hydrogen donor may be directly added to the denitrification reaction tank, or may be injected into the inflow pipe of the nitrogen-containing wastewater as raw water and introduced into the denitrification reaction tank together with the raw water.
【００１８】[0018]
【発明の実施の形態】以下に本発明の実施の形態を詳細
に説明する。Embodiments of the present invention will be described below in detail.
【００１９】本発明の方法は、硝酸性窒素を含む窒素含
有排水に水素供与体を添加して脱窒反応槽で生物脱窒処
理するに当り、該脱窒反応槽の窒素負荷量に応じて前述
のメタノール係数の設定値を増減し、水素供与体量／窒
素負荷量の割合を増減すること以外は通常の処理条件で
実施することができる。According to the method of the present invention, when a hydrogen donor is added to a nitrogen-containing wastewater containing nitrate nitrogen to carry out biological denitrification in a denitrification reactor, the nitrogen load of the denitrification reactor depends on the nitrogen load. The process can be carried out under ordinary processing conditions except that the set value of the methanol coefficient is increased or decreased and the ratio of the amount of hydrogen donor / the amount of nitrogen loaded is increased or decreased.
【００２０】実際の処理設備においては、原水である窒
素含有排水の窒素濃度及び水量を連続的に測定し、脱窒
反応槽への流入窒素負荷量を求め、予め設定した各窒素
負荷量毎に最適なメタノール係数で演算したメタノール
量でメタノールの添加制御を行う。In an actual treatment facility, the nitrogen concentration and the amount of water in the nitrogen-containing wastewater, which is raw water, are continuously measured to determine the nitrogen load flowing into the denitrification reactor, and the nitrogen load is determined for each preset nitrogen load. The addition of methanol is controlled based on the amount of methanol calculated with the optimum methanol coefficient.
【００２１】このメタノール係数の設定方法としては、
図１（ａ）に示す如く、窒素負荷量の増加に応じて連続
的にメタノール係数が増加するように設定しても良く、
また、図１（ｂ）に示す如く、窒素負荷量の増加に応じ
て段階的にメタノール係数が増加するように設定しても
良い。The method for setting the methanol coefficient is as follows.
As shown in FIG. 1A, it may be set so that the methanol coefficient increases continuously as the nitrogen load increases.
Further, as shown in FIG. 1B, the methanol coefficient may be set to increase stepwise as the nitrogen load increases.
【００２２】このメタノール係数は、予め、原水である
窒素含有排水を用いて予備試験を行うことにより設定す
ることができる。This methanol coefficient can be set in advance by conducting a preliminary test using nitrogen-containing wastewater as raw water.
【００２３】このように、窒素負荷量に対応するメタノ
ール係数を用い、窒素負荷量にメタノール係数を乗じる
ことで、窒素負荷量の変動に応じた最適なメタノール添
加量を設定することができる。As described above, by using the methanol coefficient corresponding to the nitrogen load and multiplying the nitrogen load by the methanol coefficient, it is possible to set the optimum amount of methanol to be added according to the fluctuation of the nitrogen load.
【００２４】[0024]
【実施例】以下に実施例を挙げて本発明をより具体的に
説明する。The present invention will be described more specifically with reference to the following examples.
【００２５】実施例１ 水素供与体としてメタノールを用いている、ステンレス
製造工程から排出される洗浄排水の生物脱窒処理設備
で、本発明の実証確認運転を行った。この洗浄排水は硝
酸性窒素濃度が２００〜３５０ｍｇ−Ｎ／Ｌの範囲で変
動し、処理設備の脱窒反応槽容量当りの窒素負荷量は、
０．２〜２．４ｋｇ／ｍ3／日の範囲で大幅な変動を生
じている。Example 1 A demonstration and verification operation of the present invention was performed in a biological denitrification treatment facility for washing wastewater discharged from a stainless steel production process using methanol as a hydrogen donor. This washing wastewater has a nitrate nitrogen concentration varying in the range of 200 to 350 mg-N / L, and the nitrogen load per denitrification reaction tank capacity of the processing equipment is as follows:
Significant fluctuations occur in the range of 0.2 to 2.4 kg / m 3 / day.
【００２６】この処理において、メタノール係数Ｍは、
同排水を用いた生物脱窒処理の予備検討から、脱窒反応
槽容量当りの窒素負荷量Ｎが０〜０．４４ｋｇ／ｍ3／
日の範囲内では２．１、窒素負荷量Ｎが０．４５〜０．
８７ｋｇ／ｍ3／日の範囲内では２．３、窒素負荷量Ｎ
が０．８８ｋｇ／ｍ3／日以上では２．５が、脱窒処理
効果の面から適正であると推定された。In this process, the methanol coefficient M is
From preliminary examination of biological denitrification treatment using the wastewater, the nitrogen load N per denitrification reaction tank capacity was 0 to 0.44 kg / m 3 /
Within the range of 2.1 days, the nitrogen load N is 0.45-0.
2.3 within the range of 87 kg / m 3 / day, nitrogen load N
It was estimated that 2.5 was 0.88 kg / m 3 / day or more, which was appropriate from the viewpoint of denitrification effect.
【００２７】この処理設備の運転初期は、メタノール係
数を窒素負荷量に関係なく２．３と一定に設定し、図１
（ｃ）に示す如く、窒素負荷量Ｎに対応して、メタノー
ル添加量＝Ｎ×２．３でメタノール添加量を増減させて
投入を行っていた。この運転条件下では、窒素負荷量が
０．４ｋｇ／ｍ3／日より低い時には、脱窒反応槽の後
段に設置している再曝気槽のＤＯが不足し、曝気量不足
を生じていた。また、０．８ｋｇ／ｍ3／日より高負荷
条件では、脱窒反応槽のＯＲＰが−１５０ｍｖ以上とな
り、脱窒処理に適正な酸化還元状態が得られず、脱窒処
理が不十分になっていた。その結果、処理水（再曝気槽
の後段の沈殿槽の分離水）の残留窒素が１０ｍｇ／Ｌ以
上となり、沈殿槽で内生脱窒を生じ、汚泥の浮上現象が
生じていた。In the initial stage of the operation of the treatment equipment, the methanol coefficient was set to a constant value of 2.3 irrespective of the nitrogen load.
As shown in (c), according to the nitrogen load N, the amount of methanol added was changed to N × 2.3, and the amount of methanol added was increased or decreased to perform injection. Under these operating conditions, when the nitrogen load was lower than 0.4 kg / m 3 / day, the DO in the re-aeration tank installed downstream of the denitrification reaction tank was insufficient, resulting in insufficient aeration. Further, under a load condition higher than 0.8 kg / m 3 / day, the ORP of the denitrification reaction tank becomes -150 mv or more, and a proper oxidation-reduction state cannot be obtained for the denitrification treatment, and the denitrification treatment becomes insufficient. I was As a result, the residual nitrogen in the treated water (separation water in the sedimentation tank after the re-aeration tank) became 10 mg / L or more, endogenous denitrification occurred in the sedimentation tank, and the sludge floating phenomenon occurred.
【００２８】処理水の窒素濃度の悪化を防止する観点か
ら、低負荷域でも２．５以上のメタノール係数とし、メ
タノール添加量＝Ｎ×２．５でメタノールを投入したと
ころ、再曝気槽で未分解のメタノールが処理水に残留
し、処理水のＣＯＤが１５〜２５ｍｇ／Ｌと高い値を示
した。しかも、低負荷域ではメタノール過剰なため、発
生する余剰汚泥量が多くなり、汚泥処理に問題が生じ
た。From the viewpoint of preventing the nitrogen concentration of the treated water from deteriorating, the methanol coefficient was set to 2.5 or more even in the low load region, and methanol was added at an amount of methanol added = N × 2.5. Decomposed methanol remained in the treated water, and the COD of the treated water showed a high value of 15 to 25 mg / L. In addition, excess methanol is generated in a low load region due to excess methanol, which causes a problem in sludge treatment.
【００２９】そこで、予備検討結果から得られたメタノ
ール係数Ｍを用い、窒素負荷量Ｎに応じて、段階的にメ
タノール係数Ｍを変え、次のようにしてメタノール添加
量を制御した。 窒素負荷量Ｎが０〜０．４４ｋｇ／ｍ3／日のとき：メ
タノール係数Ｍを２．１とし、メタノール投入量＝Ｎ×
２．１とする。 窒素負荷量Ｎが０．４５〜０．８７ｋｇ／ｍ3／日のと
き：メタノール係数Ｍを２．３とし、メタノール投入量
＝Ｎ×２．３とする。 窒素負荷量Ｎが０．８８ｋｇ／ｍ3／日以上のとき：メ
タノール係数Ｍを２．５とし、メタノール投入量＝Ｎ×
２．５とする。 その結果、低負荷域から高負荷域まで安定して、脱窒反
応槽内のＯＲＰは脱窒処理に最適な−２５０〜−３００
ｍｖを示し、再曝気槽内のＤＯも１．５〜３ｍｇ／Ｌの
範囲であった。また、処理水中に残留する窒素は１ｍｇ
／Ｌ以下であり、ＣＯＤも１０ｍｇ／Ｌ以下と良好な処
理が継続して行われた。余剰汚泥の発生量も、運転初期
に比べて２５〜３０％低減した。Therefore, using the methanol coefficient M obtained from the preliminary examination results, the methanol coefficient M was changed stepwise according to the nitrogen load N, and the amount of methanol added was controlled as follows. When the nitrogen load N is 0 to 0.44 kg / m 3 / day: the methanol coefficient M is 2.1, and the methanol input amount = N ×
2.1. When the nitrogen load N is 0.45 to 0.87 kg / m 3 / day: The methanol coefficient M is 2.3, and the methanol input amount is N × 2.3. When the nitrogen load N is 0.88 kg / m 3 / day or more: The methanol coefficient M is set to 2.5, and the methanol input amount = N ×
2.5. As a result, the ORP in the denitrification reaction tank is stable from the low load range to the high load range, and the ORP in the denitrification reaction tank is -250 to -300
mv, and DO in the re-aeration tank was also in the range of 1.5 to 3 mg / L. The amount of nitrogen remaining in the treated water is 1 mg
/ L or less, and the COD was 10 mg / L or less. The amount of excess sludge generated was also reduced by 25 to 30% compared to the initial stage of operation.
【００３０】[0030]
【発明の効果】以上詳述した通り、本発明の生物脱窒処
理方法によれば、窒素負荷量の変動に応じて最適な水素
供与体添加量制御を行うことができ、 最少量の水素供与体添加量で生物脱窒処理すること
ができるため、処理コストを低減することができる。 再曝気槽に流入する残留水素供与体量が少ないた
め、再曝気槽のＤＯ不足による処理水水質の低下が防止
される。また、再曝気槽のＤＯ管理も容易となり、曝気
コストも低減できる。 余剰汚泥の発生量が低減され、汚泥処理の問題が軽
減される。 等の効果が奏され、窒素濃度や水量が大きく変動する硝
酸性窒素含有排水の生物脱窒処理においても、低窒素濃
度でＢＯＤ、ＣＯＤも低い高水質の処理水を安定かつ効
率的に得ることができる。As described in detail above, according to the biological denitrification treatment method of the present invention, it is possible to control the optimal amount of the hydrogen donor to be added in accordance with the fluctuation of the nitrogen load, Since the biological denitrification treatment can be performed with the added amount of the body, the treatment cost can be reduced. Since the amount of the residual hydrogen donor flowing into the re-aeration tank is small, a decrease in the quality of the treated water due to a shortage of DO in the re-aeration tank is prevented. Further, the DO management of the re-aeration tank becomes easy, and the aeration cost can be reduced. The amount of excess sludge generated is reduced, and the problem of sludge treatment is reduced. Even in biological denitrification treatment of nitrate-nitrogen-containing wastewater in which the nitrogen concentration and water volume fluctuate greatly, high-quality treated water with low nitrogen concentration and low BOD and COD can be obtained stably and efficiently. Can be.
【図１】メタノール係数又はメタノール添加量と窒素負
荷量との関係を示すグラフである。FIG. 1 is a graph showing a relationship between a methanol coefficient or an amount of added methanol and a nitrogen load.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 藤安 英一 山口県新南陽市野村南町4976番地 日新製 鋼株式会社周南製鋼所内 (72)発明者 北川 幹夫 東京都新宿区西新宿三丁目４番７号 栗田 工業株式会社内 (72)発明者 岡野 仁史 東京都新宿区西新宿三丁目４番７号 栗田 工業株式会社内 Ｆターム(参考） 4D040 AA01 BB02 BB91 BB93 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eiichi Fujiyasu 4976 Nomura Minami-cho, Shinnanyo-shi, Yamaguchi Nisshin Steel Co., Ltd. Shunan Steel Works (72) Inventor Mikio Kitagawa 3-4 Nishishinjuku, Shinjuku-ku, Tokyo No. 7 Kurita Kogyo Co., Ltd. (72) Inventor Hitoshi Okano 3-7 Nishi Shinjuku, Shinjuku-ku, Tokyo F-term in Kurita Kogyo Co., Ltd. 4D040 AA01 BB02 BB91 BB93
Claims (1)
与体を添加して脱窒反応槽にて生物脱窒処理する方法に
おいて、該脱窒反応槽の窒素負荷量に応じて、該窒素負
荷量に対する前記水素供与体の添加比率を増減すること
を特徴とする生物脱窒処理方法。1. A method for adding a hydrogen donor to a nitrogen-containing wastewater containing nitrate nitrogen to carry out biological denitrification in a denitrification reactor, wherein the nitrogen is added to the nitrogen-containing wastewater in accordance with the nitrogen load in the denitrification reactor. A biological denitrification treatment method characterized by increasing or decreasing the ratio of the hydrogen donor to the load.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14157099A JP3622573B2 (en) | 1999-05-21 | 1999-05-21 | Biological denitrification method |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002239594A (en) * | 2001-02-20 | 2002-08-27 | Sinto Brator Co Ltd | Wastewater denitrifying method |
| JP2005087853A (en) * | 2003-09-17 | 2005-04-07 | Fuji Electric Systems Co Ltd | Method and apparatus for treating methane fermentation waste liquid |
| JP2009505822A (en) * | 2005-08-24 | 2009-02-12 | パークソン コーポレーション | Denitrification process and denitrification device |
| JP2011507691A (en) * | 2007-12-28 | 2011-03-10 | メルコスール コマーシャル エリテーデーアー． | Method to increase the concentration of microbial colonies in the process of removing impurities by anaerobic digestion |
| JP5335238B2 (en) * | 2005-06-15 | 2013-11-06 | 一般財団法人電力中央研究所 | Microbial activity control substance supply method and apparatus, environmental purification method and bioreactor using the same |
-
1999
- 1999-05-21 JP JP14157099A patent/JP3622573B2/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002239594A (en) * | 2001-02-20 | 2002-08-27 | Sinto Brator Co Ltd | Wastewater denitrifying method |
| JP2005087853A (en) * | 2003-09-17 | 2005-04-07 | Fuji Electric Systems Co Ltd | Method and apparatus for treating methane fermentation waste liquid |
| JP5335238B2 (en) * | 2005-06-15 | 2013-11-06 | 一般財団法人電力中央研究所 | Microbial activity control substance supply method and apparatus, environmental purification method and bioreactor using the same |
| JP2009505822A (en) * | 2005-08-24 | 2009-02-12 | パークソン コーポレーション | Denitrification process and denitrification device |
| JP2012187587A (en) * | 2005-08-24 | 2012-10-04 | Parkson Corp | Denitrification process and system |
| JP2011507691A (en) * | 2007-12-28 | 2011-03-10 | メルコスール コマーシャル エリテーデーアー． | Method to increase the concentration of microbial colonies in the process of removing impurities by anaerobic digestion |
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