JP3696359B2

JP3696359B2 - Wastewater treatment equipment

Info

Publication number: JP3696359B2
Application number: JP1673397A
Authority: JP
Inventors: 辰彦鈴木; 進石川; 正則山中
Original assignee: Maezawa Industries Inc
Current assignee: Maezawa Industries Inc
Priority date: 1997-01-30
Filing date: 1997-01-30
Publication date: 2005-09-14
Anticipated expiration: 2017-01-30
Also published as: JPH10211496A

Description

【０００１】
【発明の属する技術分野】
本発明は、排水処理装置に関し、詳しくは、生物膜付着担体を用いた流動床によって下排水の処理を行う排水処理装置に関する。
【０００２】
【従来の技術】
流動担体を使用した流動床による排水処理法は、生物の保持量が多く、高い撹拌力が得られることから、処理効率が良好で、コンパクトな装置で十分な排水処理を行うことが可能である。このため、従来から多くの研究が成されているが、産業排水処理における小規模施設での実用化例はあるものの、公共の下水処理等の比較的大規模での実用例はほとんど無い。
【０００３】
図４は、流動床を用いた従来の排水処理装置の一例を示すものである。この排水処理装置は、下排水の処理において、硝化処理までを行った処理水（ＮＯ₂−Ｎ，ＮＯ₃−Ｎ等の酸化態窒素を含む硝化液）を流動床を用いて脱窒処理するためのものであって、流動床からなる脱窒槽１と酸化処理を行う接触曝気槽２とを有している。脱窒槽１の内部には、生物ろ床となる流動担体（接触材，ろ材等）３ａが充填されており、この流動担体充填部３の下方に被処理水の流入部４が、上方に処理水の流出部５がそれぞれ設けられている。また、流入部４には、被処理水にメタノール等の炭素源を添加する経路６が設けられており、脱窒槽１の上部は、流動担体３が処理水と共に流出するのを防止するため、水面積が大きくなるように形成されている。
【０００４】
前記接触曝気槽２は、接触材７ａを充填した接触材充填部７の下方に散気装置８を設けたもので、槽上部に脱窒槽１からの処理水の流入部９と曝気処理水の流出部１０とが設けられている。
【０００５】
上記構成の排水処理装置は、流入部４の被処理水に経路６からメタノール等の炭素源を添加して脱窒槽１に導入し、ここで脱窒処理を行って窒素を除去した後、余剰の炭素源を接触曝気槽２で酸化処理することにより除去している。
【０００６】
【発明が解決しようとする課題】
このように、炭素源を添加して脱窒処理を行う場合、経路６からの炭素源の添加量は、タイマーあるいはｐＨ，ＯＲＰ等のセンサーにより制御することもできるが、被処理水の流入変動に対して完全に制御することは困難であり、また、炭素源を過剰に添加した方が脱窒速度が上昇することから、通常は、炭素源をある程度過剰に添加するようにしている。したがって、この場合には、過剰に添加した炭素源の余剰分を酸化して除去する手段を設ける必要があり、従来は、上述のように、脱窒槽１とは別に接触曝気槽２を設けるようにしていた。このため、装置の設置面積が大きくなるとともに、配管等も複雑になるという問題があった。
【０００７】
そこで本発明は、単一の処理槽で効率のよい脱窒処理と酸化処理とを行うことができ、装置のコンパクト化を図ることができる排水処理装置を提供することを目的としている。
【０００８】
【課題を解決するための手段】
上記目的を達成するため、本発明の排水処理装置は、処理槽の上部にプラスチック製の空隙率９０％以上の接触材を充填し、下部に流動担体を充填するとともに、前記接触材充填部と流動担体充填部との間に散気手段を設け、前記流動担体充填部の下方に被処理水の流入部を、前記接触材充填部の上方に処理水の流出部を、それぞれ設け、前記接触材充填部を、２枚の仕切板により接触材充填室、処理水循環室及び処理水流出室の３室に区画し、前記２枚の仕切板のうち、接触材充填室と処理水循環室とを区画する第１の仕切板は、その上下に処理水が通過可能な空間を形成すべく、処理水中に没して設けられており、処理水循環室と処理水流出室とを区画する第２の仕切板は、その下部にのみ処理水が通過可能な空間を形成すべく、上端を水面上に突出させて設けることによって、前記接触材充填部に過剰に流動化した流動担体を洗浄する洗浄機能を設けたことを特徴としている。
【０００９】
さらに、本発明は、前記被処理水にメタノール等の炭素源を添加する経路を備えていることを特徴としている。
【００１０】
【発明の実施の形態】
図１は、排水処理装置の参考例を示す断面図である。この排水処理装置は、処理槽１１の上部に形成した大径部に、空隙率の大きなプラスチック製接触材１２ａを充填した接触材充填部１２を設け、処理槽１１の下部に、流動担体１３ａを充填した流動担体充填部１３を設けるとともに、前記接触材充填部１２と流動担体充填部１３との間に散気手段１４を設け、流動担体充填部１３の下方に被処理水の流入部１５を、前記接触材充填部１２の上方に処理水の流出部１６をそれぞれ設けたものである。さらに、脱窒処理を効率よく行うため、前記流入部１５には、処理槽１１内に流入する被処理水にメタノール等の炭素源を添加する炭素源添加経路１７が設けられている。
【００１１】
被処理水（原水）は、炭素源添加経路１７から添加されるメタノール等の炭素源と混合した状態で流入部１５から処理槽１１の底部に流入し、流動担体充填部１３及び接触材充填部１２を上向流で流れる。被処理水は、嫌気状態で運転されている流動担体充填部１３を通過する際に脱窒処理が行われ、散気手段１４からの散気により好気状態で運転されている接触材充填部１２を通過する際に余剰の炭素源の酸化処理が行われる。
【００１２】
このように、流動床法により下排水の生物処理を行う排水処理装置において、処理槽１１の下部に主として脱窒処理を行うための流動担体１３ａを充填し、上部には炭素源の酸化処理を行うための空隙率の大きなプラスチック製接触材１２ａを充填するとともに、プラスチック製接触材１２ａの下部に散気手段１４を設けたことにより、一つの処理槽１１で脱窒処理と余剰の炭素源の酸化処理とを行うことができるので、装置の設置面積を小さくすることができ、装置全体としてのコンパクト化を図ることができる。
【００１３】
なお、本参考例及び図２の形態例で用いるプラスチック製の空隙率の大きな接触材１２ａとは、ポリエチレン，ポリプロピレン，硬質塩化ビニル等を所定形状、例えば波状、ボール状，網状，ループ状，パイプ状等に形成し、９０％以上の空隙率を有するものであって、一般に知られている排水処理用接触材を使用することができる。また、流動担体１３ａとしては、アンスラサイト，ケイ砂，活性炭，軽量骨材等からなる直径０．４〜１ｍｍ程度のものを用いることができる。
【００１４】
さらに、本参考例において、図に想像線で示すように、接触材充填部１２を通過した槽上部の処理水の一部を流動担体充填部１３の下部に循環させる循環経路１８を設け、この循環経路１８を用いて処理水の一部を循環させることにより、処理効率をさらに高めることができる。
【００１５】
図２は、本発明の排水処理装置の一形態例を示す断面図である。この排水処理装置は、処理槽２１の上部の接触材充填部に、過剰に流動化した流動担体を洗浄するための洗浄機能を設けたものである。水面積を大きくするために大きく形成されている処理槽２１の上部には、該処理槽２１の上部を、接触材充填室２２，処理水循環室２３及び処理水流出室２４の３室に区画する２枚の仕切板２５，２６が設けられている。接触材充填室２２と処理水循環室２３とを区画する第１の仕切板２５は、処理水中に没するように設けられており、その上下に処理水が通過可能な空間が形成されている。また、処理水循環室２３と処理水流出室２４とを区画する第２の仕切板２６は、上端を水面上に突出させるように設けられており、その下部にのみ処理水が通過可能な空間が形成されている。
【００１６】
前記接触材充填室２２には、前記同様のプラスチック製接触材１２ａが充填されるとともに、該プラスチック製接触材１２ａの下方に散気手段１４が設けられており、処理水は、散気手段１４からの散気による上昇力でプラスチック製接触材１２ａ部分を上昇し、ここで余剰の炭素源の酸化処理が行われるとともに、処理槽下部の流動担体充填部１３からこの接触材充填室２２にまで上昇してきた過剰に流動化した流動担体１３ｂは、散気による撹拌力によって洗浄処理される。
【００１７】
接触材充填室２２を上昇した処理水及び流動担体１３ｂは、仕切板２５の上部空間を通過して処理水循環室２３内に流入し、該処理水循環室２３内を下降する。この処理水循環室２３を下降した処理水の一部は、流動担体１３ｂと共に仕切板２５の下部空間を通過して接触材充填室２２方向に流れ、処理水及び洗浄処理が不十分な流動担体１３ｂは再び接触材充填室２２を上昇し、十分に洗浄処理された流動担体１３ｂは、下方の流動担体充填部１３へ下降していく。
【００１８】
また、処理水循環室２３を下降した処理水の残部は、仕切板２６の下部空間を通過し、水面積を比較的大きくした処理水流出室２４を上昇し、ここで流動担体１３ｂの沈降分離が行われて上部の流出部１６から流出する。
【００１９】
このように、処理槽上部の接触材充填部に、生物膜の肥大化により流動化し過ぎた流動担体の洗浄を散気による撹拌で行う機能を付加することにより、流動担体に付着する生物膜の量を適正に制御することができ、流動担体充填部１３を最適な状態に管理することができる。
【００２０】
なお、洗浄機能は、上記散気による撹拌だけでなく、処理水等を注入して強く撹拌するようにしてもよい。また、仕切板の形状は任意であり、例えばドラフトチューブ形式に形成することもできる。
【００２１】
図３は、本発明の排水処理装置を用いた排水処理設備の一例を示すものであって、前記図２に示した構造を有する処理槽２１を脱窒槽として用い、ＢＯＤ，ＳＳの処理に加えて窒素の処理も行うようにしている。
【００２２】
流入下水（原水）は、スクリーン３１を通って原水槽３２に流入した後、ポンプ３３により配管３４を介して最初沈殿池３５に流入し、沈殿処理されてから硝化促進型のエアレーションタンク３６に流入する。このエアレーションタンク３６内には、硝化菌を包括固定化した担体が投入されており、底部の散気装置３７からの散気により原水中の窒素の硝化が行われる。担体分離スクリーン３８を介してエアレーションタンク３６から流出した処理水（硝化液）は、最終沈殿池３９に送られて汚泥の分離が行われる。この最終沈殿池３９で発生した汚泥は、一部が返送汚泥としてエアレーションタンク３６に循環し、残部が余剰汚泥として汚泥貯留槽４０に送られ、最初沈殿池３５の沈殿物と一緒に処理される。
【００２３】
前記最終沈殿池３９から流出した硝化液は、中継槽４１を介して前記処理槽（脱窒槽）２１に流入する。この処理槽２１では、流入水が十分に硝化処理されたものであるから、炭素源添加経路１７からメタノール等の炭素源が流入水に添加され、槽下部の流動担体充填部１３では主に脱窒反応が行われ、槽上部の接触材充填室２２では、散気手段１４からの散気により余剰の炭素源を酸化して除去する反応が行われる。
【００２４】
処理槽２１で窒素の除去及び余剰の炭素源の除去が行われた処理水は、仕上げ処理を行うろ過槽４２に送られ、ＳＳ成分の除去等が行われた後、処理水槽４３を経て河川等に放流される。また、ろ過槽４２の洗浄排水は、経路４４により原水槽３２に戻されて再処理される。
【００２５】
このように、下水の二次処理に、硝化菌を包括固定化した担体を投入した硝化促進型のエアレーションタンク３６を用い、その処理水（硝化液）を処理槽（脱窒槽）２１で脱窒処理する流れは、窒素規制の対応を迫られている既設の下水処理場において、非常に有望な改善策となり得る。なお、仕上げ処理としてのろ過槽４２は、省略することもできる。
【００２６】
【発明の効果】
以上説明したように、本発明の排水処理装置は、上部にプラスチック製の空隙率の大きな接触材を充填し、下部に流動担体を充填するとともに、前記接触材充填部と流動担体充填部との間に散気手段を設けて上向流で下排水の処理を行うので、単一の処理槽で十分な脱窒処理と余剰炭素源の酸化除去処理とを行うことができ、装置の簡略化やコンパクト化を図ることができる。
【図面の簡単な説明】
【図１】排水処理装置の参考例を示す断面図である。
【図２】本発明の排水処理装置の一形態例を示す断面図である。
【図３】本発明の排水処理装置を用いた排水処理設備の一例を示す系統図である。
【図４】従来の流動床法による排水処理装置の一例を示す断面図である。
【符号の説明】
１１…処理槽、１２…接触材充填部、１２ａ…空隙率の大きなプラスチック製接触材、１３…流動担体充填部、１３ａ，１３ｂ…流動担体、１４…散気手段、１５…流入部、１６…流出部、１７…炭素源添加経路、１８…循環経路、２１…処理槽、２２…接触材充填室、２３…処理水循環室、２４…処理水流出室、２５，２６…仕切板、３２…原水槽、３５…最初沈殿池、３６…エアレーションタンク、３９…最終沈殿池、４０…汚泥貯留槽、４１…中継槽、４２…ろ過槽、４３…処理水槽[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wastewater treatment apparatus, and more particularly, to a wastewater treatment apparatus that treats sewage with a fluidized bed using a biofilm-adhered carrier.
[0002]
[Prior art]
The wastewater treatment method using a fluidized bed using a fluid carrier has a large amount of organisms retained and a high agitation power, so that the treatment efficiency is good and sufficient wastewater treatment can be performed with a compact device. . For this reason, a lot of research has been done so far, but there are practical examples in a small-scale facility for industrial wastewater treatment, but there are few practical examples on a relatively large scale such as public sewage treatment.
[0003]
FIG. 4 shows an example of a conventional wastewater treatment apparatus using a fluidized bed. This waste water treatment apparatus denitrifies treated water (nitrification liquid containing oxidized nitrogen such as NO ₂ -N, NO ₃ -N) that has been subjected to nitrification treatment using a fluidized bed. Therefore, it has a denitrification tank 1 composed of a fluidized bed and a contact aeration tank 2 for performing oxidation treatment. The denitrification tank 1 is filled with a fluid carrier (contact material, filter medium, etc.) 3a that serves as a biological filter bed, and the inflow portion 4 of the water to be treated is treated above the fluid carrier filling portion 3 above. Water outflow portions 5 are respectively provided. In addition, the inflow section 4 is provided with a path 6 for adding a carbon source such as methanol to the water to be treated, and the upper part of the denitrification tank 1 prevents the fluid carrier 3 from flowing out together with the treated water. The water area is increased.
[0004]
The contact aeration tank 2 is provided with an air diffuser 8 below the contact material filling section 7 filled with the contact material 7a, and the treated water inflow section 9 from the denitrification tank 1 and the aerated treated water are provided at the upper portion of the tank. An outflow part 10 is provided.
[0005]
In the wastewater treatment apparatus having the above configuration, a carbon source such as methanol is added to the water to be treated in the inflow portion 4 from the path 6 and introduced into the denitrification tank 1, where denitrification treatment is performed to remove nitrogen, and surplus The carbon source is removed by oxidizing in the contact aeration tank 2.
[0006]
[Problems to be solved by the invention]
As described above, when the denitrification treatment is performed by adding a carbon source, the amount of carbon source added from the path 6 can be controlled by a timer or a sensor such as pH, ORP, etc. However, it is difficult to completely control the carbon source, and since the denitrification rate increases when the carbon source is excessively added, the carbon source is usually added to some extent excessively. Therefore, in this case, it is necessary to provide a means for oxidizing and removing the excess of the excessively added carbon source. Conventionally, as described above, the contact aeration tank 2 is provided separately from the denitrification tank 1. I was doing. For this reason, there existed a problem that the installation area of an apparatus became large and piping etc. became complicated.
[0007]
Therefore, an object of the present invention is to provide a wastewater treatment apparatus that can perform efficient denitrification treatment and oxidation treatment in a single treatment tank, and can achieve downsizing of the apparatus.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the wastewater treatment apparatus of the present invention fills the upper part of the treatment tank with a plastic contact material having a porosity of 90% or more, and fills the lower part with a fluid carrier, the diffuser means between the fluidized carrier filling section provided, the inlet of the water to be treated beneath the fluidized carrier filling section, the outflow of the treated water above the contact material filling unit, respectively, the contact The material filling section is divided into three chambers, a contact material filling chamber, a treated water circulation chamber, and a treated water outflow chamber, by two partition plates. Of the two partition plates, the contact material filling chamber and the treated water circulation chamber are separated from each other. The first partition plate to be partitioned is immersed in the treated water so as to form a space through which the treated water can pass above and below, and a second partition that partitions the treated water circulation chamber and the treated water outflow chamber. The partition plate has an upper end to form a space through which treated water can pass only at the bottom. By providing so as to protrude on the surface, it is characterized in that a cleaning function for cleaning the excess fluidized flow carrier to the contact material filling unit.
[0009]
Furthermore, the present invention is characterized that you have provided a path for adding a carbon source such as methanol in the treated water.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view showing a reference example of a wastewater treatment apparatus. This waste water treatment apparatus is provided with a contact material filling portion 12 filled with a plastic contact material 12a having a large porosity at a large diameter portion formed at the upper portion of the treatment tank 11, and a fluid carrier 13a is provided at the lower portion of the treatment tank 11. In addition to providing the fluid carrier filling portion 13 filled, an air diffuser 14 is provided between the contact material filling portion 12 and the fluid carrier filling portion 13, and an inflow portion 15 of water to be treated is provided below the fluid carrier filling portion 13. The outflow part 16 of the treated water is provided above the contact material filling part 12. Further, in order to efficiently perform the denitrification treatment, the inflow portion 15 is provided with a carbon source addition path 17 for adding a carbon source such as methanol to the water to be treated flowing into the treatment tank 11.
[0011]
The water to be treated (raw water) flows from the inflow part 15 to the bottom of the treatment tank 11 in a state of being mixed with a carbon source such as methanol added from the carbon source addition path 17, and the fluid carrier filling part 13 and the contact material filling part. 12 flows upward. The water to be treated is denitrified when it passes through the fluid carrier filling portion 13 that is operated in an anaerobic state, and the contact material filling portion that is operated in an aerobic state due to the aeration from the aeration means 14. When passing 12, an excess carbon source is oxidized.
[0012]
In this way, in the wastewater treatment apparatus that performs biological treatment of sewage by the fluidized bed method, the lower part of the treatment tank 11 is filled with the fluid carrier 13a for mainly performing the denitrification treatment, and the carbon source is oxidized at the upper part. In addition to filling the plastic contact material 12a with a large porosity to be performed and providing the aeration means 14 at the lower portion of the plastic contact material 12a, the denitrification treatment and the surplus carbon source can be performed in one processing tank 11. Since the oxidation treatment can be performed, the installation area of the apparatus can be reduced, and the apparatus as a whole can be made compact.
[0013]
The plastic contact material 12a having a large porosity used in this embodiment and the embodiment shown in FIG. 2 is made of polyethylene, polypropylene, hard vinyl chloride or the like in a predetermined shape, for example, a wave shape, a ball shape, a net shape, a loop shape, a pipe. It is formed in a shape and has a porosity of 90% or more, and a generally known waste water treatment contact material can be used. As the fluid carrier 13a, one having a diameter of about 0.4 to 1 mm made of anthracite, silica sand, activated carbon, lightweight aggregate or the like can be used.
[0014]
Furthermore, in this reference example, as shown by an imaginary line in the figure, a circulation path 18 is provided for circulating a part of the treated water in the upper part of the tank that has passed through the contact material filling part 12 to the lower part of the fluid carrier filling part 13, By circulating a part of the treated water using the circulation path 18, the treatment efficiency can be further increased.
[0015]
FIG. 2 is a cross-sectional view showing an embodiment of the waste water treatment apparatus of the present invention. In this waste water treatment apparatus, a cleaning function for cleaning the fluid carrier that has been excessively fluidized is provided in the contact material filling unit at the top of the processing tank 21. In the upper part of the treatment tank 21 that is formed to increase the water area, the upper part of the treatment tank 21 is divided into three chambers: a contact material filling chamber 22, a treatment water circulation chamber 23, and a treatment water outflow chamber 24. Two partition plates 25 and 26 are provided. The 1st partition plate 25 which divides the contact material filling chamber 22 and the treated water circulation chamber 23 is provided so that it may be immersed in treated water, and the space which can pass treated water is formed in the upper and lower sides. Further, the second partition plate 26 that divides the treated water circulation chamber 23 and the treated water outflow chamber 24 is provided so that the upper end protrudes above the water surface, and a space through which treated water can pass only at the lower part. Is formed.
[0016]
The contact material filling chamber 22 is filled with the same plastic contact material 12a as described above, and an aeration means 14 is provided below the plastic contact material 12a. The plastic contact material 12a portion is raised by the ascending force due to the air diffused from here, and the excess carbon source is oxidized here, and from the fluid carrier filling portion 13 at the bottom of the treatment tank to the contact material filling chamber 22 The excessively fluidized fluid carrier 13b that has risen is subjected to a cleaning process by a stirring force by aeration.
[0017]
The treated water and the fluid carrier 13b that have moved up in the contact material filling chamber 22 pass through the upper space of the partition plate 25, flow into the treated water circulation chamber 23, and descend in the treated water circulation chamber 23. A part of the treated water descending the treated water circulation chamber 23 passes through the lower space of the partition plate 25 together with the fluid carrier 13b and flows toward the contact material filling chamber 22, and the fluid carrier 13b with insufficient treated water and washing treatment. Ascends the contact material filling chamber 22 again, and the fluid carrier 13b that has been sufficiently cleaned descends to the fluid carrier filling portion 13 below.
[0018]
Further, the remaining portion of the treated water descending the treated water circulation chamber 23 passes through the lower space of the partition plate 26 and ascends the treated water outflow chamber 24 having a relatively large water area, where the flow carrier 13b is settled and separated. It flows out from the upper outflow part 16.
[0019]
In this way, by adding the function of washing the fluid carrier that has become too fluidized due to the enlargement of the biofilm to the contact material filling part at the upper part of the treatment tank by agitation by aeration, the biofilm adhering to the fluid carrier is removed. The amount can be controlled appropriately, and the fluid carrier filling unit 13 can be managed in an optimum state.
[0020]
In addition, the cleaning function may not only be agitated by the above-mentioned aeration, but may be agitated strongly by injecting treated water or the like. Moreover, the shape of a partition plate is arbitrary, For example, it can also form in a draft tube form.
[0021]
FIG. 3 shows an example of a wastewater treatment facility using the wastewater treatment apparatus of the present invention. The treatment tank 21 having the structure shown in FIG. 2 is used as a denitrification tank, and in addition to the treatment of BOD and SS. Nitrogen treatment is also performed.
[0022]
The inflowing sewage (raw water) flows into the raw water tank 32 through the screen 31, then flows into the settling basin 35 through the pipe 34 by the pump 33, and after flowing into the nitrification promotion type aeration tank 36. To do. In this aeration tank 36, a carrier in which nitrifying bacteria are entrapped and immobilized is introduced, and nitrification of nitrogen in raw water is performed by aeration from an aeration device 37 at the bottom. The treated water (nitrification liquid) that has flowed out of the aeration tank 36 via the carrier separation screen 38 is sent to the final sedimentation basin 39, where sludge is separated. Part of the sludge generated in the final sedimentation basin 39 is circulated as return sludge to the aeration tank 36, and the remaining part is sent as surplus sludge to the sludge storage tank 40, where it is treated together with the sediment in the initial sedimentation basin 35. .
[0023]
The nitrification liquid flowing out from the final sedimentation basin 39 flows into the treatment tank (denitrification tank) 21 via the relay tank 41. In this treatment tank 21, the influent water has been sufficiently nitrified, so a carbon source such as methanol is added to the inflow water from the carbon source addition path 17, and the fluid carrier filling section 13 at the bottom of the tank mainly removes it. Nitrogen reaction is performed, and in the contact material filling chamber 22 at the upper part of the tank, a reaction for oxidizing and removing the excess carbon source by the air diffused from the air diffuser 14 is performed.
[0024]
The treated water from which nitrogen has been removed and the excess carbon source has been removed in the treatment tank 21 is sent to a filtration tank 42 for finishing treatment, and after removal of the SS component and the like, the treated water is passed through the treated water tank 43 to the river. And so on. In addition, the cleaning waste water in the filtration tank 42 is returned to the raw water tank 32 through the path 44 and reprocessed.
[0025]
In this way, the nitrification promotion type aeration tank 36 into which the carrier in which nitrifying bacteria are entrapped and immobilized is used for the secondary treatment of sewage, and the treated water (nitrification liquid) is denitrified in the treatment tank (denitrification tank) 21. The treatment flow can be a very promising improvement measure in existing sewage treatment plants that are forced to comply with nitrogen regulations. In addition, the filtration tank 42 as a finishing process can also be abbreviate | omitted.
[0026]
【The invention's effect】
As described above, the wastewater treatment apparatus of the present invention fills the upper part with a plastic contact material having a large porosity and fills the lower part with a fluid carrier, and includes the contact material filling part and the fluid carrier filling part. Since the sewage treatment is performed in an upward flow with an air diffuser in between, sufficient denitrification treatment and oxidation removal treatment of surplus carbon source can be performed in a single treatment tank, simplifying the equipment And downsizing can be achieved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a reference example of a wastewater treatment apparatus.
FIG. 2 is a cross-sectional view showing an embodiment of the waste water treatment apparatus of the present invention.
FIG. 3 is a system diagram showing an example of waste water treatment equipment using the waste water treatment apparatus of the present invention.
FIG. 4 is a cross-sectional view showing an example of a wastewater treatment apparatus using a conventional fluidized bed method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Processing tank, 12 ... Contact material filling part, 12a ... Plastic contact material with large porosity, 13 ... Fluid carrier filling part, 13a, 13b ... Fluid carrier, 14 ... Air diffuser, 15 ... Inflow part, 16 ... Outflow part, 17 ... carbon source addition path, 18 ... circulation path, 21 ... treatment tank, 22 ... contact material filling chamber, 23 ... treated water circulation chamber, 24 ... treated water outflow chamber, 25, 26 ... partition plate, 32 ... original Water tank, 35 ... First sedimentation basin, 36 ... Aeration tank, 39 ... Final sedimentation basin, 40 ... Sludge storage tank, 41 ... Relay tank, 42 ... Filtration tank, 43 ... Treated water tank

Claims

The upper part of the treatment tank is filled with a plastic contact material having a porosity of 90% or more , the lower part is filled with a fluid carrier, and an aeration means is provided between the contact material filling part and the fluid carrier filling part, An inflow portion of the water to be treated is provided below the fluid carrier filling portion, an outflow portion of the treated water is provided above the contact material filling portion, and the contact material filling portion is provided with a contact material filling chamber by two partition plates. The first partition plate that divides the treated water circulation chamber and the treated water outflow chamber into three chambers, and divides the contact material filling chamber and the treated water circulation chamber among the two partition plates, has treated water above and below it. In order to form a space that can pass, the second partition plate that divides the treated water circulation chamber and the treated water outflow chamber into the treated water is a space through which treated water can pass only in the lower part. to form a, and being provided so as to protrude the upper end on the water surface Water treatment equipment.

The wastewater treatment apparatus according to claim 1, further comprising a path for adding a carbon source such as methanol to the water to be treated.