JP2004167461A - Method and apparatus for anaerobic digestion process - Google Patents
Method and apparatus for anaerobic digestion process Download PDFInfo
- Publication number
- JP2004167461A JP2004167461A JP2002339623A JP2002339623A JP2004167461A JP 2004167461 A JP2004167461 A JP 2004167461A JP 2002339623 A JP2002339623 A JP 2002339623A JP 2002339623 A JP2002339623 A JP 2002339623A JP 2004167461 A JP2004167461 A JP 2004167461A
- Authority
- JP
- Japan
- Prior art keywords
- anaerobic digestion
- liquid
- solid
- anaerobic
- organic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
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
- 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
- Separation Using Semi-Permeable Membranes (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
- Treatment Of Sludge (AREA)
- Apparatus Associated With Microorganisms And Enzymes (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
Description
【0001】
【発明の属する技術分野】
本発明は、家庭・レストラン・食品工場等から排出される廃水および生ごみ等の有機性廃棄物、家庭の浄化槽・工場等の廃水処理設備・下水処理場等から排出される有機性汚泥、畜産業から排出される畜産排泄物、水産業から排出される有機性廃棄物等を嫌気性消化処理方法及び該方法を実施するための装置に関する。
【0002】
【従来の技術】
嫌気性消化(メタン発酵)は、エネルギー回収型有機性廃水及び/又は廃棄物処理技術として用いられるようになってきた。有機性廃水や廃棄物の高効率嫌気性消化処理方法として、これまでに、固液分離膜によりメタン生成菌等の分解微生物を嫌気性消化槽内に高密度に維持する方法が提案されている(特許文献1)。
しかし、この固液分離膜を利用する嫌気性消化処理方法は、その膜分離工程において微生物等の微小な粒子が膜の細孔に詰まり閉塞を起こしやすいという問題点があった。閉塞した膜は洗浄により膜分離性能を回復することができるが、膜の洗浄には膜分離装置の停止や薬液の注入などの操作が必要で、このことが維持管理の煩雑さやコスト増大の原因となるため、膜の閉塞が起こりにくい技術が求められている。
【0003】
このような膜の閉塞の問題を解消するために、嫌気性消化槽内のガスを曝気して気液混相流を起こし膜面に対して掃流として作用させる方法が提案されている(特許文献2)。
しかしながら、この方法でも、嫌気性消化槽内の微生物や懸濁物濃度が高いため、膜の閉塞が起こるという問題があった。
【0004】
一方、メタン発酵槽内の微生物濃度を高く維持する方法として、微生物を固定化する担体をメタン発酵槽内に装備する方法が提案されている(特許文献3)。
この方法は、微生物が担体に固定化されるため微生物濃度が高く維持できるという利点を有するものであるが、固液分離膜を利用する方法とは異なり、担体に固定化されない微生物も存在し、さらに未分解の有機物粒子は担体に固定化されないのでメタン発酵槽内に維持されず系外に排出される。そのため、有機物の分解率がそれほど向上しないという難点があった。
【0005】
また、前記膜分離法はメタン発酵槽外に設けられた膜分離装置により微生物を濃縮して、濃縮された微生物をメタン発酵槽に返送するという方式で、メタン発酵槽内の微生物濃度を高く維持しようとするものである。これに対して、固定化法は外部の分離装置を用いることなく、メタン発酵槽内部で微生物を担体に固定化するという方法でメタン発酵槽内の微生物濃度を高く維持するものである。
したがって、従来よりこれらの方法はそれぞれ単独で用いられる別異の方式であり、両者の方法を結合させる発想はこれまでになかった。
【0006】
【特許文献1】特許第2885737号公報
【特許文献2】特開2000−024661号公報
【特許文献3】特開平09−038686号公報
【0007】
【発明が解決しようとする課題】
本発明は、上記従来技術の実情に鑑みなされたものであって、固液分離膜を利用した有機性廃水及び/又は廃棄物の高効率嫌気性消化処理方法において、膜の閉塞が最低限に抑えられ、かつ有機物を迅速に高い分解率で分解・消化処理することができ、同時にメタンや肥料を効率的に製造することができる、工業的に有利な嫌気性消化処理方法および装置を提供することを目的とする。
【0008】
【発明を解決するための手段】
本発明者は、前記課題を解決すべく鋭意研究を重ねた結果、膜分離方法と固定化担体方法を結合させると、膜の閉塞が最低限に抑えられ、かつ有機物を迅速に高い分解率で分解・消化処理することができ、同時にメタンや肥料を効率的に製造することができることを知見し、本発明を完成するに至った。
即ち、本発明によれば、以下の発明が提供される。
(1)有機性廃水及び/又は有機性廃棄物を嫌気性消化処理し、得られる消化液を固液分離膜により分離する嫌気性消化処理方法であって、嫌気性消化処理を嫌気性消化微生物固定化担体の存在下で行うことを特徴とする有機性廃水及び/又は有機性廃棄物の嫌気性消化処理方法。
(2)有機性廃水及び/又は有機性廃棄物の嫌気性消化処理方法であって、(I)嫌気性消化微生物固定化担体の存在下で、有機物を嫌気性消化微生物によりメタンと二酸化炭素に分解する工程、(II)該分解工程で得られた消化液を固液分離膜により懸濁粒子濃縮液と脱離液に分離する工程、(III)該分離工程で得られた懸濁粒子濃縮液を嫌気性消化槽内に返送することを特徴とする嫌気性消化処理方法。
(3)(I)の工程で得られるメタンを含有する気相部を燃料とすることを特徴とする上記(2)に記載の嫌気性消化処理方法。
(4)(II)の工程で得られる脱離液及び/又は懸濁粒子濃縮液を、肥料及び/又は肥料の原料として利用することを特徴とする上記(2)に記載の嫌気性消化処理方法。
(5)固液分離膜手段と嫌気性消化槽を備えた有機性廃水及び/又は有機性廃棄物の嫌気性消化処理装置であって、該嫌気性消火槽には嫌気性消化微生物固定化担体が収容されていることを特徴とする有機性廃水及び/又は有機性廃棄物の嫌気性消化処理装置。
(6)固液分離膜手段と嫌気性消化槽を備えた有機性廃水及び/又は有機性廃棄物の嫌気性消化処理装置であって、(I)嫌気性消化微生物固定化担体を収容してなる嫌気性消化槽、(II)該嫌気性消化槽で得られた消化液を懸濁粒子濃縮液と脱離液に分離する固液分離膜手段、(III)該固液分離膜手段で分離された懸濁粒子濃縮液を嫌気性消化槽に返送する手段とを備えたことを特徴とする嫌気性消化処理装置。
【0009】
【発明の実施の形態】
本発明の特徴は、従来の固液分離膜を利用した嫌気性消化処理方法の有する、膜が閉塞し易く、有機物を迅速に高い分解率で分解・消化処理することが困難であるといった問題点を克服するために、嫌気性消化槽内に嫌気性消化微生物固定化担体を収容する点にある。
【0010】
このように嫌気性消化槽内に予め嫌気性消化微生物固定化担体(以下、担体ともいう)を収容しておくと、嫌気性消化槽内の嫌気性消化微生物(以下、単に微生物ともいう)が担体に付着・固定化されると共に分離膜によって分離された懸濁粒子濃縮液が返送された場合にも、返送された微生物は固定化担体に付着・固定化および又は分解されるため槽内での浮遊状態の微生物を減少させることができる。また微生物が浮遊した消化液を膜分離するに当たっては、消化液の微生物濃度が低いため、膜の閉塞の原因となる微生物による細孔の詰まりが著しく減少し、膜の閉塞を効率的に抑制することが可能となる。更に、本発明においては、嫌気性消化槽内の微生物濃度は、担体に固定化された微生物と膜分離によって返送された微生物とが合算された、高濃度となり、これらが同時に有機物の分解反応に加わるため、有機物のメタンと二酸化炭素への分解反応が効率よく進む。
【0011】
本発明の処理対象となる有機性廃水としては、家庭・レストラン・食品工場・発酵工場等の有機性廃水一般などが挙げられ、また、有機性廃棄物としては、家庭・レストラン・食品工場等から排出される食品残渣、食品工場・浄化槽・下水処理場等で廃水処理時に発生する有機性汚泥、畜産排泄物、水産加工廃棄物等が含まれる他、嫌気性消化した後に排出される消化汚泥などが包含される。
【0012】
本明細書でいう固液分離膜とは、それ自体公知の浸漬型平膜や中空糸膜など、孔の大きさが0.01〜1 μm、望ましくは0.1〜0.2 μmで、嫌気性消化微生物を効率よく分離濃縮できる膜を意味する。このような分離膜についてはたとえ特開昭62−181772号公報によって詳細に開示されている。
【0013】
嫌気性消化微生物固定化担体とは、嫌気性消化微生物が付着・固定化できる固形物を意味し、担体の材質は、炭素繊維、ポリウレタン、ロックウール、ヘチマなど有機や無機材料の数多くの種類を用いることができ、担体の形状は従来用いられている平板、円筒、球状、円盤状などが利用できる。
【0014】
本明細書でいう嫌気性消化微生物とは、酸発酵微生物とメタン生成微生物の総称である。酸発酵性微生物とは、嫌気性消化において有機酸等を生成する微生物を意味し、Bacteroides sp.、Clostridium sp.、Bacillus sp.、Lactobacillus sp.等があげられる。メタン生成微生物とは、嫌気性消化においてメタンを生成する微生物を意味し、Methanosarcina sp.、Methanosaeta sp.、Methanogeum sp.等があげられる。両者とも従来よく知られているものである。
【0015】
以下、本発明方法を具体的に説明する。
本発明方法においては、まず、有機性廃水及び/又は有機性廃棄物を嫌気性消化する際に、嫌気性消化槽内に前記した担体を収容することが必要である。担体を収容する方法は、固定床でも流動床でも、それらを組み合わせた方法でも良い。
この嫌気性消化処理は、嫌気性消化微生物と担体を含む嫌気性消化槽内で、有機物含量を0.001〜30%、好ましくは0.01〜90%に調整し、反応温度は10〜100℃好ましく30〜35℃の中温発酵かまたは50〜60℃の高温発酵で嫌気性消化処理させ、有機物を分解しメタンを発生させる。この嫌気性消化処理工程においては、嫌気性消化槽内には空気及び/又は酸素は供給しない。
【0016】
次に、本発明においては、嫌気性消化微生物やその他の微生物等が懸濁した消化液を、固液分離膜手段により懸濁粒子濃縮液と微生物等の懸濁粒子を含まない脱離液とに分離する。
この分離膜として、前記したように、浸漬型平膜や中空糸膜などの従来公知の分離膜が利用でき、孔の大きさが0.01〜1 μm、望ましくは0.1〜0.2 μmであるものが好ましく用いられる。この固液分離工程においては、空気及び/又は酸素を供給しないことが望ましい。
【0017】
次に、固液分離膜手段により分離された懸濁粒子濃縮液を嫌気性消化槽内に返送する。この返送工程においても、空気及び/又は酸素を供給しないことが望ましい。
【0018】
本発明方法では、担体を収容した嫌気性消化槽で嫌気性消化し、消化液を固液分離膜装置で懸濁粒子濃縮液と脱離液に分離するものであるが、担体に微生物が固定化されているので、消化液に懸濁している微生物濃度が低く、膜の閉塞を抑制することができるので、装置の維持、管理が容易となる。また、本発明においては、嫌気性消化槽内の微生物濃度は、担体に固定化された微生物と膜分離によって返送された微生物とが合算された、高濃度となり、これらが同時に有機物の分解反応に加わるため、有機物のメタンと二酸化炭素への分解反応が効率よく進む。更に本発明方法では、従来の嫌気的消化法に比べ有機物分解率が向上するため、残渣の発生量も従来法に比べ減少する。
【0019】
これに対して、固体分離膜のみを用いる従来の嫌気性消化法は、前記したように、嫌気性消化槽内の微生物濃度を高く維持できるものの、膜の閉塞の問題があり、操作性が悪く維持管理が難しいという問題点があり、本発明のように、膜の閉塞が最低限に抑えられ、かつ有機物を迅速に高い分解率で分解・消化処理することができない。
【0020】
この嫌気性消化処理時に発生するメタンは、ボイラー燃料、消化ガス発電、マイクロガスタービンや水素への改質後燃料電池の燃料として利用することが出来る。
【0021】
嫌気性消化残渣や消化液の膜分離脱離液は、窒素やリンなどの肥料成分を多く含み発酵が進んでいるので、そのまま及び/又は肥料の原料として利用すること可能である。
【0022】
次に、本発明方法を好ましく実施するための処理装置を図面を参照しながら詳述する。
図1は本発明の嫌気性消化処理装置の説明図である。
図1において、1は有機性廃水及び/又は有機性廃棄物貯留タンク、2は原料配管、3は嫌気性消化槽、4は消化液配管、5は固液分離膜装置、6は懸濁粒子濃縮液返送配管、7は脱離液配管、8は脱離液貯留タンク、9は消化ガス配管、10は消化ガス貯留タンク、11は懸濁粒子濃縮液配管、12は懸濁粒子濃縮液貯留タンクを各示す。
【0023】
図1の装置によって本発明方法を実施するには、原料貯留タンク1より原料配管2を通って、嫌気的な分解を生じさせ、担体を含有する嫌気性消化槽3に、処理対象となる有機性廃水及び/又は有機性廃棄物または返送した膜分離固形分を供給・混合する。
【0024】
この嫌気性消化槽3において、嫌気的な条件で有機物は固定化微生物と浮遊微生物の分解作用を受け、メタンと二酸化炭素が生成する。この時、担体により嫌気性消化槽3内の嫌気性微生物濃度が高いので、有機物の分解が効率よく進む。
【0025】
本発明に係る嫌気性消化槽は、酸素がない嫌気条件に保たれ、槽内の消化液を撹拌し発酵反応を促進させるために、必要に応じ撹拌装置を具備させてもよい。
【0026】
一方、嫌気性消化槽3で得られた消化液は消化液配管4を通って固液分離膜装置5に導入される。固液分離膜装置5は嫌気条件に保たれ、消化液はこの固液分離膜装置5で懸濁粒子濃縮液と懸濁粒子を含まない脱離液に分離される。この時、嫌気性消化槽3内では固定化担体に微生物が固定化されているので、消化液中の浮遊微生物の濃度が低くなっているため、固液分離膜装置の閉塞が抑制される。 得られた懸濁粒子濃縮液は嫌気性消化微生物や未分解の有機物を含有しており、懸濁粒子濃縮液返送配管6により嫌気性消化槽3に返送され、返送された嫌気性微生物の一部は固定化され一部は浮遊状態のまま再度分解反応に関与し、返送された未分解の有機物は再度メタンや二酸化炭素への分解作用を受ける。また、固液分離膜装置からの脱離液は、脱離液配管7で、脱離液貯留タンク8に移送される。
【0027】
固液分離膜装置5で発生したメタンを含む消化ガスは消化ガス配管9を通って消化ガス貯留タンク10に貯留される。この場合の消化ガスは、通常メタン50〜100モル%、二酸化炭素0〜50モル%、水素0〜10モル%を含有する。
【0028】
一方、固液分離膜装置5で得られた懸濁粒子濃縮液の一部は、懸濁粒子濃縮液配管11を通って懸濁粒子濃縮液貯留タンク12で貯留される。
【0029】
脱離液(廃水)は、通常溶存有機物や溶存無機物の濃度の低いものであり、液体肥料として利用し、必要に応じ活性汚泥法などで廃水高度処理後放流される。懸濁粒子濃縮液は、有機物の分解が十分に行われており、同時にアンモニアやリン酸を多く含むので、そのまま有機肥料及び/又は肥料の原料となる。また、脱水後固形分をそのまま又は有機肥料や土壌改良材の原料として利用しても良く、含水率が下がり十分減量化されているので、焼却処分してもよい。
【0030】
【発明の効果】
本発明方法では、固定化担体に微生物が固定化されているので、消化液に懸濁している微生物濃度が低く、膜の閉塞が起こりにくい。従って、嫌気性消化装置の操作、維持管理が容易となる。また、嫌気性消化槽内では固定化された嫌気性消化微生物と固液分離膜によって分離され、返送された浮遊嫌気性消化微生物が同時に分解反応に関わるので、従来の方法に比べ有機物のメタンと二酸化炭素への転換速度や転換率が向上する。結果として、より多くのメタンガスが発生し、残渣の発生量が少なくなり、最終的な残渣汚泥処理量が低減される。
【 図面の簡単な説明】
【図1】本発明に係る有機性汚泥の嫌気性消化処理装置の説明図である。
【符号の説明】
1.原料貯留タンク
2.原料配管
3.嫌気性消化槽
4.消化液配管
5.固液分離膜装置
6.懸濁粒子濃縮液返送配管
7.脱離液配管
8.脱離液貯留タンク
9.消化ガス配管
10.消化ガス貯留タンク
11.懸濁粒子濃縮液配管
12.懸濁粒子濃縮液貯留タンク[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to organic waste such as wastewater and garbage discharged from households, restaurants and food factories, organic sludge and livestock discharged from wastewater treatment facilities and sewage treatment plants such as household septic tanks and factories. The present invention relates to an anaerobic digestion treatment method for livestock excrement discharged from industry, organic waste discharged from fisheries, and the like, and an apparatus for performing the method.
[0002]
[Prior art]
Anaerobic digestion (methane fermentation) has been used as an energy recovery organic wastewater and / or waste treatment technology. As a high-efficiency anaerobic digestion treatment method for organic wastewater and waste, a method has been proposed in which solid-liquid separation membranes are used to maintain a high concentration of degrading microorganisms such as methanogens in an anaerobic digestion tank. (Patent Document 1).
However, the anaerobic digestion treatment method using the solid-liquid separation membrane has a problem that microscopic particles such as microorganisms are liable to be clogged in the pores of the membrane in the membrane separation step and are likely to be clogged. Although the membrane separation performance can be recovered by washing the clogged membrane, cleaning the membrane requires operations such as stopping the membrane separation device and injecting a chemical solution, which results in complicated maintenance and increased costs. Therefore, there is a demand for a technique that does not easily cause blockage of the membrane.
[0003]
In order to solve such a problem of membrane clogging, a method has been proposed in which a gas in an anaerobic digestion tank is aerated to cause a gas-liquid multiphase flow to act as a scavenging flow on the membrane surface (Patent Literature) 2).
However, this method also has a problem that the membrane is clogged because the concentration of microorganisms and suspended matter in the anaerobic digestion tank is high.
[0004]
On the other hand, as a method of maintaining a high concentration of microorganisms in a methane fermentation tank, a method of equipping a methane fermentation tank with a carrier for immobilizing microorganisms has been proposed (Patent Document 3).
This method has the advantage that the microorganism concentration can be maintained high because the microorganisms are immobilized on the carrier, but unlike the method using a solid-liquid separation membrane, there are also microorganisms that are not immobilized on the carrier, Furthermore, undecomposed organic matter particles are not fixed to the carrier and are not maintained in the methane fermentation tank and are discharged out of the system. For this reason, there was a problem that the decomposition rate of the organic matter was not so improved.
[0005]
Further, the membrane separation method is a method in which microorganisms are concentrated by a membrane separation device provided outside the methane fermentation tank, and the concentrated microorganisms are returned to the methane fermentation tank, thereby maintaining a high concentration of microorganisms in the methane fermentation tank. What you are trying to do. On the other hand, the immobilization method is a method of immobilizing microorganisms on a carrier inside a methane fermentation tank without using an external separation device, thereby maintaining a high concentration of microorganisms in the methane fermentation tank.
Therefore, conventionally, these methods are different methods used independently, and there has never been an idea to combine the two methods.
[0006]
[Patent Document 1] Japanese Patent No. 2885737 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-024661 [Patent Document 3] Japanese Patent Application Laid-Open No. 09-038686 [0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances of the prior art, and in the method for highly efficient anaerobic digestion treatment of organic wastewater and / or waste using a solid-liquid separation membrane, membrane clogging is minimized. Provided is an industrially advantageous anaerobic digestion treatment method and apparatus that can suppress and can decompose and digest organic substances quickly and at a high decomposition rate, and can efficiently produce methane and fertilizers at the same time. The purpose is to:
[0008]
[Means for Solving the Invention]
The present inventor has conducted intensive studies to solve the above problems, and as a result, when the membrane separation method and the immobilized carrier method are combined, the clogging of the membrane is suppressed to a minimum, and organic substances are rapidly decomposed at a high decomposition rate. They have found that they can be decomposed and digested, and at the same time can efficiently produce methane and fertilizers, and have completed the present invention.
That is, according to the present invention, the following inventions are provided.
(1) An anaerobic digestion method in which organic wastewater and / or organic waste is subjected to anaerobic digestion and the obtained digested liquid is separated by a solid-liquid separation membrane. An anaerobic digestion treatment method for organic wastewater and / or organic waste, which is performed in the presence of an immobilized carrier.
(2) An anaerobic digestion treatment method for organic wastewater and / or organic waste, wherein (I) organic matter is converted into methane and carbon dioxide by anaerobic digestion microorganisms in the presence of an anaerobic digestion microorganism-immobilized carrier. Decomposing, (II) separating the digested liquid obtained in the decomposition step into a suspended particle concentrate and a desorbed liquid by a solid-liquid separation membrane, and (III) concentrating the suspended particles obtained in the separation step. An anaerobic digestion method comprising returning a liquid to an anaerobic digestion tank.
(3) The anaerobic digestion treatment method according to the above (2), wherein the methane-containing gas phase obtained in the step (I) is used as a fuel.
(4) The anaerobic digestion treatment according to the above (2), wherein the desorbed solution and / or the suspended particle concentrate obtained in the step (II) is used as a fertilizer and / or a raw material of the fertilizer. Method.
(5) An apparatus for anaerobic digestion of organic wastewater and / or organic waste, comprising a solid-liquid separation membrane means and an anaerobic digestion tank, wherein the anaerobic fire extinguishing tank has an anaerobic digestion microorganism-immobilized carrier. An apparatus for anaerobic digestion of organic wastewater and / or organic waste, characterized in that the wastewater is stored therein.
(6) An apparatus for anaerobic digestion of organic wastewater and / or organic waste comprising a solid-liquid separation membrane means and an anaerobic digestion tank, wherein (I) an anaerobic digestion microorganism-immobilized carrier is accommodated. Anaerobic digestion tank, (II) solid-liquid separation membrane means for separating the digested liquid obtained in the anaerobic digestion tank into a suspension particle concentrate and a separation liquid, and (III) separation by the solid-liquid separation membrane means. An anaerobic digestion treatment apparatus comprising: means for returning the concentrated suspended particle liquid to an anaerobic digestion tank.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
A feature of the present invention is that the conventional anaerobic digestion method using a solid-liquid separation membrane has a problem that the membrane is easily clogged and it is difficult to quickly decompose and digest organic substances at a high decomposition rate. In order to overcome this problem, an anaerobic digestion tank is provided with an anaerobic digestion microorganism-immobilized carrier.
[0010]
As described above, when the anaerobic digestion tank is preliminarily accommodated with the anaerobic digestion microorganism-immobilized carrier (hereinafter, also referred to as a carrier), the anaerobic digestion microorganism in the anaerobic digestion tank (hereinafter, also simply referred to as a microorganism) is contained. Even when the suspended particle concentrate that has been attached and fixed to the carrier and separated by the separation membrane is returned, the returned microorganisms are attached, fixed, and / or decomposed to the immobilized carrier, so that The suspended microorganisms can be reduced. In addition, when membrane separation of digested juice in which microorganisms are suspended is performed, since the concentration of microorganisms in the digested juice is low, clogging of pores by microorganisms that cause membrane blockage is significantly reduced, and membrane blockage is efficiently suppressed. It becomes possible. Furthermore, in the present invention, the concentration of microorganisms in the anaerobic digestion tank becomes a high concentration, which is the sum of the microorganisms fixed on the carrier and the microorganisms returned by membrane separation, and these are simultaneously involved in the decomposition reaction of organic substances. As a result, the decomposition reaction of organic matter into methane and carbon dioxide proceeds efficiently.
[0011]
Organic wastewater to be treated according to the present invention includes general organic wastewater from households, restaurants, food factories, fermentation factories, and the like.Organic wastes include those from households, restaurants, food factories, and the like. Includes discharged food residues, organic sludge generated during wastewater treatment in food factories, septic tanks, sewage treatment plants, etc., livestock excreta, fishery processing waste, and digested sludge discharged after anaerobic digestion. Is included.
[0012]
The solid-liquid separation membrane referred to in the present specification means a pore size of 0.01 to 1 μm, preferably 0.1 to 0.2 μm, such as a known immersion type flat membrane or hollow fiber membrane, It means a membrane that can efficiently separate and concentrate anaerobic digestive microorganisms. Such a separation membrane is disclosed in detail, for example, in JP-A-62-181772.
[0013]
The anaerobic digestion microorganism-immobilized carrier means a solid substance to which the anaerobic digestion microorganism can be attached and immobilized, and the material of the carrier can be any of a variety of organic and inorganic materials such as carbon fiber, polyurethane, rock wool, and loofah. The carrier can be used in the form of a conventionally used flat plate, cylinder, sphere, disk, or the like.
[0014]
The term "anaerobic digestive microorganism" as used herein is a general term for an acid-fermenting microorganism and a methane-producing microorganism. Acid-fermenting microorganisms refer to microorganisms that produce organic acids and the like in anaerobic digestion, and include Bacteroides sp. Clostridium sp. Bacillus sp. Lactobacillus sp. And the like. A methane-producing microorganism refers to a microorganism that produces methane in anaerobic digestion, and is described in Methanosarcina sp. , Methanosaeta sp. , Metanogeum sp. And the like. Both are well known in the past.
[0015]
Hereinafter, the method of the present invention will be specifically described.
In the method of the present invention, first, when anaerobically digesting organic wastewater and / or organic waste, it is necessary to accommodate the above-described carrier in an anaerobic digestion tank. The method for accommodating the carrier may be a fixed bed, a fluidized bed, or a combination thereof.
In this anaerobic digestion treatment, the organic matter content is adjusted to 0.001 to 30%, preferably 0.01 to 90% in an anaerobic digestion tank containing an anaerobic digestion microorganism and a carrier, and the reaction temperature is 10 to 100%. Anaerobic digestion treatment is carried out by medium temperature fermentation at preferably 30 to 35 ° C or high temperature fermentation at 50 to 60 ° C to decompose organic substances and generate methane. In this anaerobic digestion treatment step, no air and / or oxygen is supplied into the anaerobic digestion tank.
[0016]
Next, in the present invention, the digested liquid in which anaerobic digestive microorganisms and other microorganisms are suspended, the suspension liquid concentrated liquid and the desorbed liquid containing no suspended particles such as microorganisms by solid-liquid separation membrane means. To separate.
As the separation membrane, as described above, a conventionally known separation membrane such as an immersion type flat membrane or a hollow fiber membrane can be used, and the pore size is 0.01 to 1 μm, preferably 0.1 to 0.2 μm. Those having a size of μm are preferably used. In this solid-liquid separation step, it is desirable not to supply air and / or oxygen.
[0017]
Next, the suspended particle concentrate separated by the solid-liquid separation membrane is returned to the anaerobic digestion tank. It is desirable not to supply air and / or oxygen even in this returning step.
[0018]
In the method of the present invention, anaerobic digestion is performed in an anaerobic digestion tank containing a carrier, and the digested solution is separated into a suspended particle concentrate and a desorbed solution by a solid-liquid separation membrane device. Because of this, the concentration of microorganisms suspended in the digestive juice is low, and membrane clogging can be suppressed, so that maintenance and management of the device are facilitated. In the present invention, the concentration of microorganisms in the anaerobic digestion tank is a high concentration obtained by adding the microorganisms immobilized on the carrier and the microorganisms returned by membrane separation, and these are simultaneously involved in the decomposition reaction of organic substances. As a result, the decomposition reaction of organic matter into methane and carbon dioxide proceeds efficiently. Further, in the method of the present invention, since the decomposition rate of organic substances is improved as compared with the conventional anaerobic digestion method, the amount of generated residues is also reduced as compared with the conventional method.
[0019]
In contrast, the conventional anaerobic digestion method using only a solid separation membrane, as described above, can maintain a high concentration of microorganisms in the anaerobic digestion tank, but has a problem of membrane blockage and poor operability. There is a problem that it is difficult to maintain and manage, and as in the present invention, clogging of the membrane is minimized, and organic substances cannot be rapidly decomposed and digested at a high decomposition rate.
[0020]
Methane generated during this anaerobic digestion process can be used as fuel for boiler fuel, digestive gas power generation, micro gas turbines, or fuel cells after reforming to hydrogen.
[0021]
Since the anaerobic digestion residue and the membrane separation desorbed solution of digested juice contain a large amount of fertilizer components such as nitrogen and phosphorus and the fermentation is progressing, it can be used as it is and / or as a raw material of the fertilizer.
[0022]
Next, a processing apparatus for preferably carrying out the method of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory view of the anaerobic digestion treatment apparatus of the present invention.
In FIG. 1, 1 is an organic wastewater and / or organic waste storage tank, 2 is a raw material pipe, 3 is an anaerobic digestion tank, 4 is a digestive liquid pipe, 5 is a solid-liquid separation membrane device, and 6 is suspended particles. Concentrated liquid return pipe, 7 is a desorbed liquid pipe, 8 is a desorbed liquid storage tank, 9 is a digested gas pipe, 10 is a digested gas storage tank, 11 is a suspended particle concentrated liquid pipe, and 12 is a suspended particle concentrated liquid storage Each tank is shown.
[0023]
In order to carry out the method of the present invention by the apparatus shown in FIG. 1, an anaerobic decomposition is caused from a raw material storage tank 1 through a
[0024]
In the
[0025]
The anaerobic digestion tank according to the present invention may be maintained under anaerobic conditions without oxygen, and may be provided with a stirring device as needed in order to stir the digestion solution in the tank and promote the fermentation reaction.
[0026]
On the other hand, the digestion fluid obtained in the
[0027]
The digestion gas containing methane generated in the solid-liquid
[0028]
On the other hand, a part of the suspended particle concentrate obtained by the solid-liquid
[0029]
The desorbed liquid (waste water) usually has a low concentration of dissolved organic substances and dissolved inorganic substances, is used as a liquid fertilizer, and is discharged after advanced treatment of waste water by an activated sludge method as required. Since the suspended particle concentrate has sufficiently decomposed organic substances and contains a large amount of ammonia and phosphoric acid at the same time, it can be used as a raw material for organic fertilizer and / or fertilizer as it is. Further, the solid content after dehydration may be used as it is or as a raw material of an organic fertilizer or a soil improvement material, and may be incinerated because the water content is reduced and the amount is sufficiently reduced.
[0030]
【The invention's effect】
In the method of the present invention, since the microorganisms are immobilized on the immobilization carrier, the concentration of the microorganisms suspended in the digestive juice is low, and the membrane is not easily blocked. Therefore, the operation and maintenance of the anaerobic digester become easy. In the anaerobic digestion tank, the immobilized anaerobic digestion microorganisms and the suspended anaerobic digestion microorganisms separated and returned by the solid-liquid separation membrane are simultaneously involved in the decomposition reaction. The conversion rate and conversion rate to carbon dioxide are improved. As a result, more methane gas is generated, the amount of residue generated is reduced, and the final residual sludge throughput is reduced.
[Brief description of drawings]
FIG. 1 is an explanatory view of an apparatus for anaerobic digestion of organic sludge according to the present invention.
[Explanation of symbols]
1. Raw
Claims (6)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002339623A JP2004167461A (en) | 2002-11-22 | 2002-11-22 | Method and apparatus for anaerobic digestion process |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002339623A JP2004167461A (en) | 2002-11-22 | 2002-11-22 | Method and apparatus for anaerobic digestion process |
Publications (1)
Publication Number | Publication Date |
---|---|
JP2004167461A true JP2004167461A (en) | 2004-06-17 |
Family
ID=32702535
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2002339623A Pending JP2004167461A (en) | 2002-11-22 | 2002-11-22 | Method and apparatus for anaerobic digestion process |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2004167461A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006150216A (en) * | 2004-11-29 | 2006-06-15 | National Institute Of Advanced Industrial & Technology | Method for treating organic waste |
JP2009213990A (en) * | 2008-03-10 | 2009-09-24 | Fuji Electric Holdings Co Ltd | Methane fermentation method and apparatus |
US8968557B2 (en) | 2011-05-26 | 2015-03-03 | Paul T. Baskis | Method and apparatus for converting coal to petroleum product |
CN105601070A (en) * | 2016-01-13 | 2016-05-25 | 长沙上意电子科技有限公司 | Organic waste anaerobic digestion-microbial electrolysis coupling reaction system and method thereof |
US9829108B2 (en) | 2009-01-21 | 2017-11-28 | Brondolin S.P.A. | Die casting piston and ring assembly |
-
2002
- 2002-11-22 JP JP2002339623A patent/JP2004167461A/en active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006150216A (en) * | 2004-11-29 | 2006-06-15 | National Institute Of Advanced Industrial & Technology | Method for treating organic waste |
JP2009213990A (en) * | 2008-03-10 | 2009-09-24 | Fuji Electric Holdings Co Ltd | Methane fermentation method and apparatus |
US9829108B2 (en) | 2009-01-21 | 2017-11-28 | Brondolin S.P.A. | Die casting piston and ring assembly |
US8968557B2 (en) | 2011-05-26 | 2015-03-03 | Paul T. Baskis | Method and apparatus for converting coal to petroleum product |
CN105601070A (en) * | 2016-01-13 | 2016-05-25 | 长沙上意电子科技有限公司 | Organic waste anaerobic digestion-microbial electrolysis coupling reaction system and method thereof |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Zabranska et al. | Bioconversion of carbon dioxide to methane using hydrogen and hydrogenotrophic methanogens | |
US7083956B2 (en) | Method for hydrogen production from organic wastes using a two-phase bioreactor system | |
KR100841089B1 (en) | The apparatus and methods of the biogas production by using anaerobic digestion coupled with membrane | |
JPWO2011043144A1 (en) | Plant wastewater treatment method and treatment system | |
CN106915883B (en) | A kind of endogenous FNA pretreating sludge minimizing and process for reclaiming | |
Maurya et al. | Recent advances and future prospective of biogas production | |
Arvanitoyannis et al. | Food waste treatment methodologies | |
JP4864339B2 (en) | Organic waste processing apparatus and processing method | |
KR100985374B1 (en) | Method and apparatus for the production of hydrogen and methane from organic wastes | |
JP2006255538A (en) | Method and apparatus for treatment of food waste | |
JP2004167461A (en) | Method and apparatus for anaerobic digestion process | |
JP3873114B2 (en) | Processing method of organic solid waste | |
KR100750502B1 (en) | Organic livestock sewage treatment apparatus and organic livestock sewage treatment method | |
JP2006255537A (en) | Method and apparatus for treating garbage and paper refuse | |
JP3191400B2 (en) | Anaerobic treatment equipment | |
JP2001232388A (en) | Method and apparatus for treating waste liquor | |
KR102131743B1 (en) | Bio-reactor for sewage treatment and sewage treatment system comprising the same | |
JP3699999B2 (en) | Treatment method of organic sludge | |
KR20150029084A (en) | Sludge solubilization type elutriated two-phase anaerobic digestion apparatus and mixed wastewater treatment method using the same | |
JP2004243204A (en) | Digestion treatment method for organic waste | |
JP2003340412A (en) | Method for anaerobic digestive treatment of organic waste and apparatus therefor | |
JP2001149983A (en) | Bio gas generator | |
JP2007044661A (en) | Methane fermentation method | |
JP2008080336A (en) | Method and apparatus for generating biogas | |
KR20190001090A (en) | Bio-reactor for sewage treatment and sewage treatment system comprising the same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20040818 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20060907 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20060912 |
|
A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20070130 |