JP3687292B2 - Method for entrapping immobilization of nitrifying bacteria and method for producing entrapping immobilization support - Google Patents
Method for entrapping immobilization of nitrifying bacteria and method for producing entrapping immobilization support Download PDFInfo
- Publication number
- JP3687292B2 JP3687292B2 JP21415297A JP21415297A JP3687292B2 JP 3687292 B2 JP3687292 B2 JP 3687292B2 JP 21415297 A JP21415297 A JP 21415297A JP 21415297 A JP21415297 A JP 21415297A JP 3687292 B2 JP3687292 B2 JP 3687292B2
- Authority
- JP
- Japan
- Prior art keywords
- activated sludge
- nitrifying bacteria
- activity
- entrapping immobilization
- carrier
- 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.)
- Expired - Fee Related
Links
Images
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
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
- Biological Treatment Of Waste Water (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、硝化細菌の包括固定化方法及びその担体に係り、特に包括固定化担体の活性度と担体強度の改良に関する。
【０００２】
【従来の技術】
廃水処理に用いられる活性汚泥中には硝化細菌が存在し、この硝化細菌と廃水中のアンモニア性窒素とが生物的に反応することにより硝化処理が行なわれる。しかし、この硝化細菌は脱窒細菌等の他の細菌に比べて増殖速度が遅く、特に冬場の低水温時期に細菌数が少なくなり、硝化性能が著しく低下する。
【０００３】
このことから、硝化細菌を含む活性汚泥を担体の表面や内部に固定化して硝化細菌を高濃度化し、これにより硝化性能を改善することが行なわれている。
硝化細菌の固定化を大別すると付着型と包括型があり、付着型は硝化細菌を含む活性汚泥を担体表面に自然付着させる方法である。一方、包括型は硝化細菌を含む活性汚泥を担体の内部に保持する方法であり、この２種類の固定化を比較すると、包括型は付着型よりも硝化細菌の活性の立ち上がりが速く、活性の安定性にも優れている。
【０００４】
ところで、硝化細菌を包括固定化する際に使用される固定化剤や重合開始剤は、微生物の活性度に阻害作用を及ぼすことは以前より知られている。
【０００５】
【発明が解決しようとする課題】
しかしながら、硝化細菌を包括固定化する際の固定化剤や重合開始剤を同じにしても包括固定化された硝化細菌の活性度や担体強度が悪い場合があるという欠点がある。従って、廃水処理に使用する包括固定化担体のロットによって廃水の処理性能にバラツキが生じてしまうという問題があった。
【０００６】
本発明は、このような事情に鑑みて成されたもので、硝化細菌の活性度と担体強度を高め、且つ安定した品質の包括固定化担体を製造することのできる硝化細菌の包括固定化方法及びその担体を提供することを目的とする。
【０００７】
【課題を解決するための手段】
本発明は前記目的を達成するために、硝化細菌を含有する活性汚泥を、固定化剤と混合して原材料を調製し、該原材料を重合してゲル化することにより前記硝化細菌を前記固定化剤内に包括固定化する硝化細菌の包括固定化方法において、硝化活性度を活性汚泥全体の呼吸速度に対する活性汚泥中の硝化細菌の呼吸速度の百分率で示した場合に、前記包括固定化される前の活性汚泥中の硝化細菌の前記硝化活性度を２０〜６０％の範囲に設定することを特徴とする。
【０００８】
また、本発明は前記目的を達成するために、硝化活性度を活性汚泥全体の呼吸速度に対する活性汚泥中の硝化細菌の呼吸速度の百分率で示した場合に、前記活性汚泥中の硝化細菌の前記硝化活性度を２０〜６０％の範囲に設定した活性汚泥を、固定化剤と混合して原材料を調製し、該原材料を重合してゲル化して得られることを特徴とする。本発明によれば、包括固定化される前の活性汚泥中の硝化細菌の硝化活性度を所定範囲に設定するようにしたので、包括固定化された後の硝化細菌の硝化活性と担体強度を高め、且つ品質が一定な包括固定化担体を作成することができる。
【０００９】
【発明の実施の形態】
以下添付図面に従って本発明に係る硝化細菌の包括固定化方法及びその担体の好ましい実施の形態について詳説する。
硝化細菌の硝化活性と担体強度の高い包括固定化担体を作成するには、包括固定化操作において重合反応を速やかに、且つ確実に進行させる必要がある。本発明の発明者等は、この重合反応の速度が包括固定化操作を行う前の活性汚泥中の硝化細菌の馴養度合いを示す指標である硝化細菌の硝化活性度により大きな影響を受けることを発見した。
【００１０】
本発明は、この知見に基づいてなされたものであり、本発明の硝化細菌の包括固定化方法及びその担体は、包括固定化前における活性汚泥中の硝化細菌の硝化活性度に着目し、その硝化活性度を所定範囲に設定するようにしたものであり、より具体的には、硝化活性度が１０〜７０％、好ましくは２０〜６０％に設定するように構成される。
【００１１】
上記構成において、硝化活性度が１０〜７０％、好ましくは２０〜６０％に設定された活性汚泥は、下水処理場の標準活性汚泥の中から選別してもよく、或いは前記硝化活性度のものを実験室にて調製することもできる。
次に、本発明の包括固定化方法及び担体を上記の如く構成した理論的な根拠について説明する。
【００１２】
先ず、活性汚泥中の硝化細菌の硝化活性度を判定する方法について説明する。活性汚泥の硝化活性度は、アンモニア性窒素が十分に存在する状態、例えばＮＨ4 −Ｎ濃度が５ｍｇ／ｌ程度の状態での活性汚泥全体の呼吸活性に対する活性汚泥中の硝化細菌の呼吸活性で示した。ここでは、呼吸活性として、酸素利用速度を測定し、硝化細菌の酸素利用速度はアリルチオ尿素を５ｍｇ／ｌ添加した状態での酸素利用速度を活性汚泥全体の酸素利用速度から引いて求めた。即ち、硝化活性度（Ａ）は次式で表すことができる。
【００１３】
【数１】
Ｃ：活性汚泥中の硝化細菌の酸素利用速度
Ｄ：アリルチオ尿素を５ｍｇ／ｌ添加による酸素利用速度
尚、本実施の形態では、活性汚泥中の硝化細菌の硝化活性度を呼吸速度から導くようにしたが、特にこの判定法に限るものではない。例えば、活性汚泥全体の菌数に対する活性汚泥中の硝化細菌の菌数を指標とすることでも可能である。要は活性汚泥中の硝化細菌の馴養度合いを判定できれば良い。
【００１４】
次に、包括固定化を行う前の活性汚泥中の硝化細菌の馴養度合いと重合反応の速度との関係を説明する。
図１は、下水処理場の標準活性汚泥処理施設から採取した活性汚泥であり、活性汚泥の硝化活性度が４０％のもの（サンプルＡと称す）を、固定化剤と混合して原材料を調製し、該原材料を重合してゲル化することにより硝化細菌を固定化剤内に包括固定化したものである。一方、図２は、前記活性汚泥をアンモニア性窒素（ＮＨ4 −Ｎ）濃度が３０ｍｇ／ｌの無機合成廃水で馴養して活性汚泥の硝化活性度を９０％にしたもの（サンプルＢと称す）を同様に包括固定化したものである。また、コントロールサンプルとして、活性汚泥を全く混合しないで固定化剤のみを重合した場合について行った。
【００１５】
この時の包括固定化の条件は、固定化剤として、アクリルアミドとメチレンビスアクリルアミドの混合溶液を使用し、各固定化剤の濃度を、製造される担体体積当たりの重量％にしてアクリルアミドを１５％、メチレンビスアクリルアミドを１％の割合で混合した。重合開始剤としては、過硫酸カリウムを使用した。
そして、包括固定化操作を行った場合の、重合反応の速度を、固定化剤の重合反応に伴う温度上昇がピークになるまでの時間を比較した。
【００１６】
その結果、図１に示すように、硝化活性度が４０％のサンプルＡの活性汚泥を用いた場合には、活性汚泥の濃度を高めるに従ってピーク時間が短くなった。即ち、コントロールサンプル（図中ａ）のピーク温度までの重合時間が約６分であるのに対し、活性汚泥濃度が１２０００ｍｇ／ｌ（図中ｂ）の時のピーク時間は約４分、活性汚泥濃度が３３０００ｍｇ／ｌ（図中ｃ）の時のピーク時間は約１．５分であった。
【００１７】
一方、図２から分かるように、硝化活性度が９０％のサンプルＢの活性汚泥を用いた場合には、活性汚泥の濃度を高めると、逆にピーク温度までの重合時間がコントロールサンプル（図中ｄ）よりも長くなった。即ち、コントロールサンプル（図中ｄ）のピーク温度までの重合時間が約６分であるのに対し、活性汚泥濃度が１００００ｍｇ／ｌ（図中ｅ）の時のピーク時間は約６．５分、活性汚泥濃度が２４０００ｍｇ／ｌ（図中ｆ）の時のピーク時間は約８分であった。
【００１８】
このことは、活性汚泥中の硝化細菌の馴養度合い、即ち活性汚泥の硝化活性度により、固定化剤の重合反応が促進される場合と促進されない場合があることを意味する。
そこで、活性汚泥の硝化活性度を変化させた場合に、硝化細菌の活性度と担体の物理的強度がどのように推移するかを調べた。
【００１９】
下水処理場の標準活性汚泥処理施設から硝化活性度の異なる活性汚泥を採取すると共に、採取した活性汚泥をアンモニア無機合成廃水で馴養することにより、硝化活性度が８％〜９５％の範囲の活性汚泥を調整し、これらを包括固定化操作に供した。
この時の包括固定化の条件は、固定化剤として、ポリエチレングリコールプレポリマーを用い、固定化剤の濃度を、製造される担体体積当たりの重量％にしてポリエチレングリコールプレポリ２を１５％とし、活性汚泥濃度で１５０００ｍｇ／ｌになるように調整した。
【００２０】
図３は、包括固定化前の活性汚泥の硝化活性度と、包括固定化操作により得られた包括固定化担体における硝化細菌の活性及び担体強度との関係を示したものである。硝化細菌の活性は、包括固定化前の硝化活性に対する包括固定化後の硝化活性の比である活性残存率で示した。また、担体の物理的強度は、担体を圧縮した時に担体が破壊するまでの圧縮強度（ｋｇ／ｃｍ2 ）で示した。
【００２１】
図３において、□−□の曲線は活性残存率を示し、■−■は担体の圧縮強度を示す。図３から分かるように、硝化活性度を大きくしていくに従って活性残存率も大きくなり、硝化活性度が２０％から６０％の範囲でほぼ安定し、再び低下する傾向があり、硝化活性度が１０％未満、または７０％を越えると活性残存率の低下度合いが大きくなる。硝化活性度が７０％を越えると、固定化剤の重合時間が長くなり、ゲル化前の固定化剤や重合開始剤などの薬剤と硝化細菌との接触により菌体の活性が阻害される為と考えられる。また、硝化活性度が１０％未満の場合には、活性汚泥中の硝化細菌の菌数が少ないことが包括固定化操作による活性残存率の低下が大きくなったものと推察される。従って、硝化活性度が１０％未満、または７０％を越える活性汚泥で作成した包括固定化担体を、実際の廃水処理装置に使用した場合には硝化性能が発揮されるまでに長時間を要してしまうという問題が生じる。
【００２２】
また、担体の圧縮強度は、硝化活性度が８％から６０％までは略３．８ｋｇ／ｃｍ2 で推移し、その後低下する傾向があり、硝化活性度が７０％が越えると圧縮強度の低下度合いが大きくなる。硝化活性度が７０％を越えると重合反応が緩慢になり担体強度が低下するものと推察される。従って、硝化活性度が７０％を越える活性汚泥で作成した包括固定化担体を、実際の廃水処理装置に使用した場合には、担体の寿命が短くなるばかりでなく、担体の破損により処理水が濁るという問題が生じる。
【００２３】
以上の結果から、硝化細菌の活性度と担体の物理的強度の両方を満足させるためには、包括固定化前の活性汚泥の硝化活性度を１０％〜７０％、好ましくは２０％〜６０％の範囲に設定すれば良いことが分かる。
そして、上記の如く構成された本発明の包括固定化担体によれば、包括固定化後の担体中の硝化細菌の活性残存率を大きくすることができ、且つ担体の物理的強度も向上させることができる。
【００２４】
また、本発明の包括固定化担体によれば、包括固定化前の活性汚泥の硝化活性度を１０％〜７０％、好ましくは２０％〜６０％の範囲に設定することにより、包括固定化後の担体中の硝化細菌の活性残存率と担体強度をほぼ一定にすることができるので、安定した品質の包括固定化担体を得ることができる。
尚、本実施の形態では、固定化剤として、アクリルアミドとメチレンビスアクリルアミドの混合液、ポリエチレングリコールプレポリマーを用いたが、重合反応によりゲル化する物質であればこれらに限定されない。また、重合開始剤は過硫酸カリウムに限らない。
【００２５】
【発明の効果】
以上説明したように、本発明の硝化細菌の包括固定化方法及びその担体によれば、硝化細菌の活性残存率と担体強度を高め、且つ安定した品質の包括固定化担体を得ることができる。
【図面の簡単な説明】
【図１】図１は、硝化活性度が４０％の活性汚泥を用いて包括固定化操作を行った時の重合速度を説明する説明図
【図２】図２は、硝化活性度が９０％の活性汚泥を用いて包括固定化操作を行った時の重合速度を説明する説明図
【図３】図３は、活性汚泥の硝化活性度と、硝化細菌の活性度及び担体の物理的強度との関係を説明する説明図
【符号の説明】
ａ…活性汚泥濃度が０ｍｇ／ｌのコントロールサンプル
ｂ…硝化活性度が４０％で活性汚泥濃度が１２０００ｍｇ／ｌの場合
ｃ…硝化活性度が４０％で活性汚泥濃度が３３０００ｍｇ／ｌの場合
ｄ…活性汚泥濃度が０ｍｇ／ｌのコントロールサンプル
ｅ…硝化活性度が９０％で活性汚泥濃度が１００００ｍｇ／ｌの場合
ｆ…硝化活性度が９０％で活性汚泥濃度が２４０００ｍｇ／ｌの場合[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for entrapping immobilization of nitrifying bacteria and a carrier thereof, and more particularly to improvement in activity and carrier strength of a entrapping immobilization carrier.
[0002]
[Prior art]
Nitrifying bacteria exist in the activated sludge used for wastewater treatment, and the nitrification treatment is carried out by biological reaction between the nitrifying bacteria and ammonia nitrogen in the wastewater. However, this nitrifying bacterium has a slower growth rate than other bacteria such as denitrifying bacterium, and the number of bacteria is reduced particularly during the low water temperature period in winter, so that the nitrifying performance is significantly lowered.
[0003]
For this reason, activated sludge containing nitrifying bacteria is immobilized on the surface or inside of the carrier to increase the concentration of nitrifying bacteria, thereby improving the nitrification performance.
The fixation of nitrifying bacteria can be broadly classified into attachment type and inclusion type, and the attachment type is a method in which activated sludge containing nitrifying bacteria is naturally attached to the surface of the carrier. On the other hand, the entrapment type is a method in which activated sludge containing nitrifying bacteria is retained inside the carrier. Comparing these two types of immobilization, the entrapment type has faster activation of nitrifying bacteria than the adherent type, and the activity Excellent stability.
[0004]
By the way, it has been known for a long time that an immobilizing agent and a polymerization initiator used for comprehensively immobilizing nitrifying bacteria have an inhibitory effect on the activity of microorganisms.
[0005]
[Problems to be solved by the invention]
However, there is a drawback that the activity and carrier strength of the entrapped nitrifying bacteria may be poor even if the fixing agent and the polymerization initiator used for entrapping immobilizing nitrifying bacteria are the same. Therefore, there is a problem that the wastewater treatment performance varies depending on the lot of the entrapping immobilization carrier used for wastewater treatment.
[0006]
The present invention has been made in view of such circumstances, and includes a method for comprehensively immobilizing nitrifying bacteria, which can increase the activity and carrier strength of nitrifying bacteria and can produce a entrapped immobilizing carrier with stable quality. And its support.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention prepares raw materials by mixing activated sludge containing nitrifying bacteria with a fixing agent, polymerizes the raw materials and gels the nitrifying bacteria. In the entrapped immobilization method of nitrifying bacteria that are entrapped and immobilized within the agent, the nitrifying activity is expressed as a percentage when the nitrifying activity is expressed as a percentage of the respiration rate of the nitrifying bacteria in the activated sludge relative to the respiration rate of the entire activated sludge. and sets the nitrification activity before the nitrifying bacteria in the activated sludge in the range of 20% to 60%.
[0008]
Further, the present invention in order to achieve the above object, the case shown nitrification activity as a percentage of the respiration rate of the nitrifying bacteria in the activated sludge of the entire activated sludge against respiratory rate, the nitrifying bacteria in the activated sludge An activated sludge whose nitrification activity is set to a range of 20 to 60% is mixed with a fixing agent to prepare a raw material, and the raw material is polymerized to be gelled. According to the present invention, since the nitrification activity of the nitrifying bacteria in the activated sludge before comprehensive immobilization is set within a predetermined range, the nitrification activity and carrier strength of the nitrifying bacteria after comprehensive immobilization are set. It is possible to produce a entrapping immobilization carrier having high quality and constant quality.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for comprehensively fixing nitrifying bacteria and a carrier thereof according to the present invention will be described in detail below with reference to the accompanying drawings.
In order to prepare a entrapping immobilization carrier having high nitrifying activity and carrier strength of nitrifying bacteria, it is necessary to advance the polymerization reaction promptly and reliably in the entrapping immobilization operation. The inventors of the present invention have found that the speed of this polymerization reaction is greatly influenced by the nitrification activity of nitrifying bacteria, which is an index indicating the degree of nitrifying bacteria's acclimatization in the activated sludge before the comprehensive immobilization operation. did.
[0010]
The present invention has been made on the basis of this finding, and the nitrifying bacteria entrapping and immobilizing method of the present invention and its carrier pay attention to the nitrifying activity of the nitrifying bacteria in the activated sludge before entrapping immobilization. The nitrification activity is set to a predetermined range, and more specifically, the nitrification activity is set to 10 to 70%, preferably 20 to 60%.
[0011]
In the above configuration, the activated sludge whose nitrification activity is set to 10 to 70%, preferably 20 to 60%, may be selected from the standard activated sludge of a sewage treatment plant, or of the nitrification activity Can also be prepared in the laboratory.
Next, the theoretical basis for constructing the entrapping immobilization method and carrier of the present invention as described above will be described.
[0012]
First, a method for determining the nitrification activity of nitrifying bacteria in activated sludge will be described. The nitrification activity of activated sludge is the respiration activity of nitrifying bacteria in activated sludge with respect to the respiration activity of the activated sludge in the state where ammonia nitrogen is sufficiently present, for example, the NH 4 -N concentration is about 5 mg / l. Indicated. Here, the oxygen utilization rate was measured as the respiratory activity, and the oxygen utilization rate of nitrifying bacteria was determined by subtracting the oxygen utilization rate in the state where 5 mg / l of allylthiourea was added from the oxygen utilization rate of the entire activated sludge. That is, the nitrification activity (A) can be expressed by the following equation.
[0013]
[Expression 1]
[0014]
Next, the relationship between the degree of acclimatization of the nitrifying bacteria in the activated sludge before the entrapping immobilization and the speed of the polymerization reaction will be described.
Fig. 1 shows activated sludge collected from a standard activated sludge treatment facility at a sewage treatment plant. The activated sludge with a nitrification activity of 40% (referred to as Sample A) is mixed with a fixing agent to prepare raw materials. The nitrifying bacteria are entrapped and immobilized in the immobilizing agent by polymerizing the raw material and gelling. On the other hand, FIG. 2 shows that the activated sludge is conditioned with inorganic synthetic wastewater having an ammoniacal nitrogen (NH 4 -N) concentration of 30 mg / l and the nitrification activity of the activated sludge is 90% (referred to as sample B). Is comprehensively fixed in the same manner. Moreover, it carried out about the case where only a fixing agent was polymerized, without mixing activated sludge as a control sample.
[0015]
The conditions for entrapping immobilization at this time were as follows. A mixed solution of acrylamide and methylene bisacrylamide was used as the immobilizing agent, and the concentration of each immobilizing agent was set to 15% by weight per carrier volume to be produced. Methylene bisacrylamide was mixed at a ratio of 1%. As the polymerization initiator, potassium persulfate was used.
And the time until the temperature rise accompanying the polymerization reaction of a fixing agent peaked was compared with the rate of the polymerization reaction when the entrapping immobilization operation was performed.
[0016]
As a result, as shown in FIG. 1, when the activated sludge of sample A having a nitrification activity of 40% was used, the peak time became shorter as the activated sludge concentration was increased. That is, while the polymerization time to the peak temperature of the control sample (a in the figure) is about 6 minutes, the peak time when the activated sludge concentration is 12000 mg / l (b in the figure) is about 4 minutes. The peak time when the concentration was 33000 mg / l (c in the figure) was about 1.5 minutes.
[0017]
On the other hand, as can be seen from FIG. 2, when the activated sludge of sample B having a nitrification activity of 90% was used, the polymerization time up to the peak temperature was conversely increased by increasing the activated sludge concentration. It became longer than d). That is, while the polymerization time to the peak temperature of the control sample (d in the figure) is about 6 minutes, the peak time when the activated sludge concentration is 10,000 mg / l (e in the figure) is about 6.5 minutes. The peak time when the activated sludge concentration was 24000 mg / l (f in the figure) was about 8 minutes.
[0018]
This means that the polymerization reaction of the immobilizing agent may or may not be accelerated depending on the degree of acclimatization of the nitrifying bacteria in the activated sludge, that is, the nitrifying activity of the activated sludge.
Therefore, it was examined how the activity of nitrifying bacteria and the physical strength of the carrier change when the nitrification activity of activated sludge is changed.
[0019]
By collecting activated sludge with different nitrification activity from the standard activated sludge treatment facility at the sewage treatment plant and acclimatizing the collected activated sludge with ammonia mineral synthetic wastewater, the nitrification activity is in the range of 8% to 95%. The sludge was adjusted and subjected to comprehensive immobilization operation.
The conditions for entrapping immobilization at this time were polyethylene glycol prepolymer as the immobilizing agent, the concentration of the immobilizing agent was set to 15% by weight per unit volume of the produced carrier, and
[0020]
FIG. 3 shows the relationship between the nitrification activity of activated sludge before entrapping immobilization and the activity and carrier strength of nitrifying bacteria in the entrapping immobilization support obtained by the entrapping immobilization operation. The activity of nitrifying bacteria was represented by the activity remaining ratio, which is the ratio of the nitrifying activity after entrapping immobilization to the nitrifying activity before entrapping immobilization. Further, the physical strength of the carrier is indicated by the compressive strength (kg / cm 2 ) until the carrier breaks when the carrier is compressed.
[0021]
In FIG. 3, the □-□ curve indicates the residual activity rate, and ■-■ indicates the compressive strength of the carrier. As can be seen from FIG. 3, as the nitrification activity is increased, the activity remaining rate is also increased, the nitrification activity is almost stable in the range of 20% to 60%, and tends to decrease again. If it is less than 10% or exceeds 70%, the degree of decrease in the activity remaining rate becomes large. If the nitrification activity exceeds 70%, the polymerization time of the immobilizing agent becomes longer, and the activity of the cells is inhibited by the contact between the nitrifying bacteria and the agent such as the immobilizing agent and the polymerization initiator before gelation. it is conceivable that. Further, when the nitrification activity is less than 10%, it is presumed that the decrease in the activity remaining rate due to the entrapping immobilization operation is large due to the small number of nitrifying bacteria in the activated sludge. Therefore, when a entrapping immobilization support made with activated sludge having a nitrification activity of less than 10% or more than 70% is used in an actual wastewater treatment device, it takes a long time to exhibit nitrification performance. Problem arises.
[0022]
In addition, the compressive strength of the carrier tends to decrease at a rate of 3.8 kg / cm 2 from 8% to 60% and then decrease, and when the nitrification activity exceeds 70%, the compressive strength decreases. The degree increases. If the nitrification activity exceeds 70%, it is presumed that the polymerization reaction becomes slow and the carrier strength decreases. Therefore, when the entrapping immobilization support made of activated sludge having a nitrification activity exceeding 70% is used in an actual wastewater treatment apparatus, not only the life of the support is shortened, but also the treated water is lost due to breakage of the support. The problem of turbidity arises.
[0023]
From the above results, in order to satisfy both the activity of nitrifying bacteria and the physical strength of the carrier, the nitrification activity of the activated sludge before comprehensive immobilization is 10% to 70%, preferably 20% to 60%. It can be seen that it should be set within the range.
According to the entrapping immobilization carrier of the present invention configured as described above, the activity remaining rate of nitrifying bacteria in the carrier after entrapping immobilization can be increased, and the physical strength of the carrier can also be improved. Can do.
[0024]
Further, according to the entrapping immobilization carrier of the present invention, the nitrification activity of the activated sludge before entrapping immobilization is set in the range of 10% to 70%, preferably 20% to 60%, so that after entrapping immobilization. Since the residual activity rate of nitrifying bacteria in the carrier and the carrier strength can be made almost constant, a entrapping immobilization carrier with stable quality can be obtained.
In this embodiment, a mixed solution of acrylamide and methylene bisacrylamide and a polyethylene glycol prepolymer are used as the immobilizing agent, but the fixing agent is not limited to these as long as it is a substance that gels by a polymerization reaction. Further, the polymerization initiator is not limited to potassium persulfate.
[0025]
【The invention's effect】
As described above, according to the method for entrapping immobilization of nitrifying bacteria and the carrier of the present invention, it is possible to increase the activity remaining rate of nitrifying bacteria and the strength of the carrier, and to obtain a entrapping immobilization carrier with stable quality.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram for explaining a polymerization rate when an entrapping immobilization operation is performed using activated sludge having a nitrification activity of 40%. FIG. 2 is a diagram showing a nitrification activity of 90%. FIG. 3 is a diagram for explaining the polymerization rate when the entrapping immobilization operation is performed using the activated sludge of FIG. 3. FIG. 3 shows the nitrification activity of activated sludge, the activity of nitrifying bacteria, and the physical strength of the carrier. Explanatory diagram explaining the relationship of [signs]
a ... control sample with activated sludge concentration of 0 mg / l b ... when nitrification activity is 40% and activated sludge concentration is 12000 mg / l c ... when nitrification activity is 40% and activated sludge concentration is 33000 mg / l d ... Control sample with activated sludge concentration of 0 mg / l e ... when nitrification activity is 90% and activated sludge concentration is 10,000 mg / l f ... when nitrification activity is 90% and activated sludge concentration is 24,000 mg / l
Claims (3)
硝化活性度を前記活性汚泥全体の呼吸速度に対する前記活性汚泥中の硝化細菌の呼吸速度の百分率で示した場合に、
前記包括固定化される前の活性汚泥中の硝化細菌の前記硝化活性度を２０〜６０％の範囲に設定することを特徴とする硝化細菌の包括固定化方法。Activated sludge containing nitrifying bacteria is mixed with a fixing agent to prepare a raw material, and the raw material is polymerized and gelled to comprehensively fix the nitrifying bacteria in the fixing agent. In the immobilization method,
When the nitrification activity is expressed as a percentage of the respiration rate of nitrifying bacteria in the activated sludge with respect to the respiration rate of the entire activated sludge,
The entrapping immobilization method of nitrifying bacteria and sets the nitrification activity of nitrifying bacteria in the activated sludge prior to being the entrapping immobilization in the range of 20% to 60%.
前記活性汚泥中の硝化細菌の前記硝化活性度を２０〜６０％の範囲に設定した活性汚泥を、固定化剤と混合して原材料を調製し、該原材料を重合してゲル化して得られることを特徴とする硝化細菌の包括固定化担体の製造方法。 When the nitrification activity is expressed as a percentage of the respiration rate of nitrifying bacteria in the activated sludge with respect to the respiration rate of the entire activated sludge,
Said activated sludge set nitrification activity in the range of 20% to 60% of nitrifying bacteria in the activated sludge, raw materials were prepared by mixing the immobilizing agent, it can be obtained by gelling the raw material polymer to A method for producing a entrapping immobilization carrier for nitrifying bacteria characterized by the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21415297A JP3687292B2 (en) | 1997-07-24 | 1997-07-24 | Method for entrapping immobilization of nitrifying bacteria and method for producing entrapping immobilization support |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21415297A JP3687292B2 (en) | 1997-07-24 | 1997-07-24 | Method for entrapping immobilization of nitrifying bacteria and method for producing entrapping immobilization support |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1133577A JPH1133577A (en) | 1999-02-09 |
| JP3687292B2 true JP3687292B2 (en) | 2005-08-24 |
Family
ID=16651092
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21415297A Expired - Fee Related JP3687292B2 (en) | 1997-07-24 | 1997-07-24 | Method for entrapping immobilization of nitrifying bacteria and method for producing entrapping immobilization support |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3687292B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1354786A (en) * | 1999-06-10 | 2002-06-19 | 株式会社拜克 | High-concentration culture method of nitrifying bacteria and denitrifying bacteria in activated sludge, culture accelerator for high-concentration culture method of nitrifying bacteria, and weight-reducing processing method of activated sludge |
| JP4203853B2 (en) * | 2003-11-13 | 2009-01-07 | 株式会社日立プラントテクノロジー | Method for producing nitrite-type nitrification carrier |
| JP4235836B2 (en) | 2006-03-23 | 2009-03-11 | 株式会社日立プラントテクノロジー | Comprehensive immobilization carrier, method for producing the same, and wastewater treatment method and apparatus using the same |
| JP5105251B2 (en) * | 2008-09-24 | 2012-12-26 | 株式会社日立プラントテクノロジー | Comprehensive immobilization carrier and method for producing the same |
-
1997
- 1997-07-24 JP JP21415297A patent/JP3687292B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1133577A (en) | 1999-02-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Dong et al. | Thermally reversible hydrogels: III. Immobilization of enzymes for feedback reaction control | |
| Sumino et al. | Immobilization of nitrifying bacteria by polyethylene glycol prepolymer | |
| KR101344801B1 (en) | Entrapping immobilization pellets and process for producing the same, and wastewater treatment process and equipment using the same | |
| JPH1052268A (en) | Carrier for microorganism and its production | |
| JPH0380803B2 (en) | ||
| JP3687292B2 (en) | Method for entrapping immobilization of nitrifying bacteria and method for producing entrapping immobilization support | |
| JP5282700B2 (en) | Manufacturing method and apparatus for entrapping immobilization carrier | |
| DE69816890T2 (en) | Process for performing a biocatalytic reaction | |
| JP3361570B2 (en) | Microorganism immobilization method using polymer hydrogel granules | |
| JPS60153998A (en) | Wastewater treatment agent and its manufacturing method | |
| JP3265981B2 (en) | Entrapping immobilization carrier for nitrogen removal and method for forming the same | |
| JP3422229B2 (en) | Method and apparatus for producing entrapped immobilized carrier | |
| Colmenarejo et al. | An analysis of the factors that influence biological phosphorous removal (BPR) in a sequencing batch anaerobic/aerobic reactor | |
| Piedade et al. | Behaviour of catalase immobilised on poly (acrylonitrile)‐g. co‐hydroxyethyl methacrylate when used in a continuous system | |
| JPS62166889A (en) | Immobilized microorganism, production thereof and treatment of water using said immobilized microorganism | |
| JP3422234B2 (en) | Method for producing entrapped immobilized carrier | |
| EP1316533A2 (en) | Chemical-resistant bioreactor carrier, processes for producing the carrier and use of the carrier | |
| CN1276882C (en) | Water treatment system | |
| CN121780503A (en) | A method for microbial 3D printing embedding and immobilization based on dual-network hydrogel | |
| JPH0141113B2 (en) | ||
| JPS6261583A (en) | Immobilization method of nitrifying bacteria | |
| JP2007237144A (en) | Method and apparatus for treating nitrogen-containing water | |
| JPS6168196A (en) | Wastewater treatment agent | |
| JP2008012383A (en) | Entrapment immobilization support, wastewater treatment apparatus and wastewater treatment method using inclusion immobilization support | |
| JPH0242475B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20040618 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20040629 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20040824 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20050208 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20050401 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20050517 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20050530 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080617 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090617 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090617 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100617 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100617 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110617 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120617 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130617 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130617 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140617 Year of fee payment: 9 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |