JP4710168B2

JP4710168B2 - Pressurized fluidized bed wastewater treatment system

Info

Publication number: JP4710168B2
Application number: JP2001152273A
Authority: JP
Inventors: 浩一茂木
Original assignee: IHI Corp
Current assignee: IHI Corp
Priority date: 2001-05-22
Filing date: 2001-05-22
Publication date: 2011-06-29
Anticipated expiration: 2021-05-22
Also published as: JP2002346582A

Description

【０００１】
【発明の属する技術分野】
本発明は下水や産業排水等の有機性排水中の有機成分を、加圧流動型のリアクター内に収納した微生物付着担体の微生物により分解させる加圧流動床方式排水処理装置に関するものである。
【０００２】
【従来の技術】
下水や産業排水、たとえば、食品製造分野、アルコール製造分野、紙パルプ製造分野、化学・石油化学分野の排水、及び、畜産、ごみ浸出水、し尿、嫌気処理水等の有機性排水の処理手法の一つとしては、微細砂等の粒状担体に好気性の微生物を担持させて表面に微生物膜を形成させてなる微生物付着担体を、リアクターに充填し、該リアクターに有機性排水を上向流又は下向流で通水して上記微生物付着担体を流動状態とさせ、この流動する微生物付着担体に担持された好気性微生物により有機性排水中の有機物の分解除去を行わせる好気性流動床方式の排水処理装置がある。
【０００３】
しかし、有機性排水中の有機物の生物処理を行う場合は、通常、処理すべき有機物量、すなわち、ＢＯＤ量に対して重量比で０．５〜１．０以上の溶存酸素を与えなければならないのに対し、上記好気性流動床方式の排水処理装置では、処理すべき有機性排水に対する酸素の溶解を大気圧の下で行うようにしていたため、たとえ純酸素ガスを吹き込んだとしても得られる溶存酸素濃度が低く、したがって、有機性排水を希釈してから酸素ガスを吹き込まざるを得ず、装置の大型化を招くという問題があり、かかる問題点を解決するために、従来、好気性微生物を担持させた微生物付着担体を充填してある流動床方式のリアクターを加圧状態とすることにより、リアクター内の処理すべき有機性排水中の溶存酸素濃度を高めることができるようにして、好気性処理の処理能力を高めるようにした加圧流動床方式の排水処理装置が開発されてきている。この種、加圧流動床方式排水処理装置としては、処理反応に必須となる酸素含有ガス（主に空気）を加圧状態のリアクター内部に直接注入することにより、該加圧されたリアクター内部にて酸素を有機性排水に溶解させる方式のもの（特開平４−４０２９５号）と、リアクターの前段に加圧された溶解槽を設けて、該溶解槽にて処理すべき有機性排水中に加圧下で予め酸素を溶解させた後、該酸素の溶解された有機性排水を加圧状態のままリアクターに供給する方式のもの（特開昭５４−８１６６０号、特開昭５６−１００６９５号）が従来提案されており、特に、酸素溶解効率面からは、後者の方が優れたものとなっている。
【０００４】
すなわち、上記リアクターの前段に溶解槽を設ける形式の加圧流動床方式排水処理装置は、図３にその一例の概略を示す如く、底部２ａに排水入口３を設け、又、上部側壁に処理水取出口４を設け、且つ頂部２ｂにガス出口５を設けて、内部に、微細砂等の粒状担体に好気性微生物を担持させて表面に好気性微生物膜を形成させてなる微生物付着担体６を充填してなるリアクター１を構成し、該リアクター１の上記排水入口３に、リアクター１の外側に配置した上下方向に延びる筒型の加圧容器となる溶解槽７の下端部を、高酸素濃度排水供給ライン８を介して接続し、且つ上記溶解槽７は、頂部に、図示しないポンプを備えた排水供給部から加圧状態、たとえば、０．５〜０．７ＭＰａで供給される有機性排水１０を導く排水供給ライン９を接続すると共に、底部に、コンプレッサー１２を加圧空気送給ライン１１を介して接続した構成として、排水供給部より排水供給ライン９を通して溶解槽７に加圧された状態で送られる有機性排水１０に、該溶解槽７内にてコンプレッサー１２より加圧空気送給ライン１１を通して送給される加圧空気１３を吹き込むことにより、約８０％の窒素と約２０％の酸素とからなる加圧空気１３の酸素のほぼ全量と窒素の一部を溶解させて有機性排水１０中の溶存酸素濃度を高めることができるようにしてあり、更に、上記リアクター１の処理水取出口４には、減圧弁１５を備えた処理水取出ライン１４を接続した構成として、溶解槽７にて溶存酸素濃度の高められた有機性排水１０ａを、加圧状態のまま高酸素濃度排水供給ライン８を通してリアクター１に導き、該リアクター１の排水入口３より処理水取出口４に向かう有機性排水１０ａの上昇流により微生物付着担体６を流動させながら該微生物付着担体６の微生物により有機性排水１０ａ中の有機成分を、十分な酸素の存在する状態で酸化分解させ、しかる後、該有機成分が分解されて清浄化された処理水１６を、処理水取出口４よりオーバーフローさせて、処理水取出ライン１４を通して回収できるようにしてある。
【０００５】
なお、上記溶解槽７における加圧条件の下でも有機性排水１０ａ中に溶解せずに残る窒素主体の排気ガス１７は、溶解槽７の頂部より図示しない減圧弁付の放出ラインを通して大気中に放出するようにしてある。又、リアクター１内部で発生するガス１８は、該リアクター１のガス出口５に接続した図示しない減圧弁を備えたガス排出ラインを通して回収するようにしてある。
【０００６】
【発明が解決しようとする課題】
ところが、図３に示した如き従来の加圧流動床方式排水処理装置では、リアクター１において微生物付着担体６を流動させるためのエネルギーが、リアクター１内を排水入口３から処理水取出口４へ向かう有機性排水１０ａの上昇流のみであり、処理対象となる有機性排水１０の排水量のみではリアクター１内にて形成される上昇流が弱くて、微生物付着担体６の流動が不十分になる虞があるため、必要な上昇流速、すなわち、微生物付着担体６の流動エネルギーを確保するには、リアクター１の外部に循環ポンプ等の外部補助装置を設けなければならないという問題があり、このため消費電力が大きくなるという問題がある。又、たとえ上記外部補助装置を設けたとしても、微生物付着担体６のリアクター１内における流動はプラグフロー的になるため、排水入口３の近傍となる下部に位置する微生物付着担体６には非常に高い負荷がかかる一方、リアクター１の上部の微生物付着担体６には低い負荷しかかからず、このため微生物付着担体６に担持された微生物の潜在保有能力を１００％生かすことができないと共に、余剰増殖微生物量が増加してしまうという問題もある。更に、微生物付着担体６の微生物膜が徐々に肥厚するようになると、その見かけ比重が小さくなってリアクター１から外へ流出する虞が生じるようになるため、これを防止するために、肥厚した微生物膜をこれを担持する粒状担体から剥離、分離する手段、たとえば、リアクター１より微生物付着担体６を取り出すためのポンプ及び微生物付着担体６を撹拌して肥厚した微生物膜を分離するための撹拌機等を設けることが必要になると考えられるが、設備費用、消費電力、効率等の面で実用的なものは提案されていないというのが実状である。更に又、外部補助装置によりリアクター１内における微生物付着担体６と有機性排水１０ａとの流動接触に必要な上昇流速を確保した場合、上昇流速を増加すればするほど微生物付着担体６の系外流出を招き易くなり、結果的に処理能力の低下を招く虞があるという問題もある。
【０００７】
更に、溶解槽７にて、たとえ５００ｋＰａ前後まで加圧したとしても、有機性排水１０中に溶解させることのできる酸素量は大気圧下で溶解させることのできる酸素量の５倍程度までであるため、ＢＯＤ量の大きな有機性排水１０に対しては、要求される溶存酸素濃度を十分に満たせない虞があり、このため、酸素供給量の更なる増加を図ることも望まれている。
【０００８】
そこで、本発明は、外部補助装置を要することなく微生物付着担体をリアクター内で効率よく循環させることができて、用いる微生物付着担体にかかる負荷の偏りを解消することができ、又、微生物付着担体の肥厚した微生物膜を剥離、除去することができ、更に、酸素供給量を高めることができて、ＢＯＤ量の大きな有機性排水も処理可能な加圧流動床方式排水処理装置を提供しようとするものである。
【０００９】
【課題を解決するための手段】
本発明は、上記課題を解決するために、底部に排水入口を設け且つ上部側壁に処理水取出口を設けて内部に流動層を形成するようにして微生物付着担体を収納してなるリアクター内に、頂部を貫通して上記処理水取出口よりも所要寸法下方の位置へ達するように下方に延びるようにガスリフト管を配し、該ガスリフト管の上端部をガス分離槽に連結し、上記リアクターの排水入口に、処理すべき有機性排水に加圧下で加圧空気を吹き込むことにより溶存酸素濃度を高めた有機性排水を供給できるようにした溶解槽を接続し、且つ上記ガスリフト管の下端部に、上記溶解槽の排気ガスを導くための加圧ガスラインを接続し、更に、上記ガス分離槽の下端部に一端部を接続した排水循環ラインの他端部を、上記溶解槽の頂部に接続してなり、上記溶解槽からガスリフト管に導入される排気ガスによるガスリフトポンプ効果によりリアクター内の微生物付着担体及び有機性排水をガスリフト管を通してガス分離槽に汲み上げ、該汲み上げられた微生物付着担体及び有機性排水を、自重により上記排水循環ライン、溶解槽を経由してリアクターの排水入口へ循環させるようにした構成とする。
【００１０】
有機性排水は、溶解槽において加圧された状態で加圧空気が吹き込まれて溶存酸素濃度が高められた有機性排水とされた後、リアクター内に底部の排水入口から供給され、該入口より処理水取出口に向かう間に、該有機性排水の上昇流に伴って流動する微生物付着担体と接触させられて、有機成分が十分な酸素の存在の下で酸化分解され、該酸化分解により清浄化された処理水は、処理水取出口より回収されるようになる。この際、溶解槽より加圧ガスラインを通してガスリフト管の下端部に導かれた排気ガスは、ガスリフト管内を急速に上昇させられ、この排気ガスの急速な上昇に伴うガスリフトポンプ効果により、ガスリフト管の下端部より有機性排水及び微生物付着担体がガス分離槽まで汲み上げられる。ガス分離槽に汲み上げられた有機性排水及び微生物付着担体は、ガス分離槽内で排気ガスと分離され、自重により排水循環ラインを通して溶解槽に導かれ、該溶解槽内にて新たに供給される有機性排水に混入されると共に、再度加圧空気が吹き込まれて溶存酸素濃度が高められた状態でリアクターの下端部まで戻される。これにより、ガスリフト管の下端部よりも下方となるリアクター内の下部の領域には、リアクターの下端部から上方に向かった後、ガスリフト管、ガス分離槽、排水循環ライン、溶解槽を経由して再びリアクターの下端部に戻る有機性排水と微生物付着担体の循環流が生じさせられ、このため有機性排水と微生物付着担体の強い流動接触状態が形成される。一方、ガスリフト管の下端部よりも上方で且つ処理水取出口よりも下方となる領域では、処理対象水量に相当する量の有機性排水が下方から上方に通過するのみで、緩やかな流動状態となる。
【００１１】
又、上部側壁に処理水取出口を設けて内部に流動層を形成するようにして微生物付着担体を収納してなるリアクター内に、下端部に高酸素濃度排水出口を有する溶解槽を上下方向に配して、その下端をリアクター内底部に一体に組み付け、該溶解槽の上端部に上記リアクターの外部より処理すべき有機性排水の供給ラインを接続すると共に、下端部に加圧空気の送給ラインを接続して、溶解槽内の処理すべき有機性排水に加圧下で加圧空気を吹き込むことにより溶存酸素濃度を高めた有機性排水を上記高酸素濃度排水出口より上記リアクターの下端部に供給できるようにし、且つ上記リアクター内に、頂部を貫通して上記処理水取出口よりも所要寸法下方の位置へ達するように下方に延びるようにガスリフト管を配して、該ガスリフト管の下端部と、上記溶解槽内の上端とを加圧ガスラインを介して接続すると共に、該ガスリフト管の上端部をガス分離槽に接続し、更に上記ガス分離槽の底部に接続した下降管を、リアクターの頂部及び溶解槽の頂部を貫通させて、下端部を該溶解槽内の有機性排水中に没入させ、上記溶解槽からガスリフト管に入る排気ガスによるガスリフトポンプ効果によりリアクター内の微生物付着担体及び有機性排水をガスリフト管を通してガス分離槽に汲み上げ、該汲み上げられた微生物付着担体及び有機性排水を、自重により上記下降管、溶解槽を経由してリアクターの下端部へ循環させるようにした構成とすることにより、溶解槽の下端部からリアクターの下端部に供給された有機性排水と微生物付着担体が上昇してガスリフト管内を汲み上げられるため、ガスリフト管の下端部よりも下方となるリアクター内の下部の領域に、ガスリフト管、ガス分離槽、下降管、溶解槽を経由して再びリアクターの下端部に戻る有機性排水と微生物付着担体の循環流を形成させることができ、装置をコンパクトなものとすることができる。
【００１２】
【発明の実施の形態】
以下、本発明の実施の形態を図面を参照して説明する。
【００１３】
図１は本発明の加圧流動床方式排水処理装置の実施の一形態を示すもので、図３に示したものと同様に底部に排水入口３を設け且つ上部側壁に処理水取出口４を設けて内部に流動層を形成するようにして微生物付着担体６を収納するようにした構成としてある加圧流動床方式排水処理装置におけるリアクター１の上方位置に、ガス分離槽１９を設置して、該ガス分離槽１９の底部を貫通させて上端部を挿入させたガスリフト管２０の下端部を、リアクター１の頂部２ｂを貫通させて処理水取出口４より所要寸法低い位置に達する深さ位置まで達するように配設すると共に、リアクター１の外側に配設した溶解槽５の上端部と上記ガスリフト管２０の下端部とをリアクター１の側壁を貫通させた加圧ガスライン２１にて接続して、溶解槽７の加圧条件下においても有機性排水１０中に溶解せずに残る窒素主体の排気ガス１７を、上記加圧ガスライン２１を通してガスリフト管２０の下端部に導いて該ガスリフト管２０内を上昇させることによりガスリフトポンプ効果を生じさせるようにし、更に、上記ガス分離槽１９の下端部と、溶解槽７の頂部とを排水循環ライン２２を介し接続して、上記ガスリフトポンプ効果によりリアクター１よりガスリフト管２０内を通してガス分離槽１９へ汲み上げられる有機性排水１０ａを、排水循環ライン２２を通して溶解槽７に導くことができるようにする。
【００１４】
２３は下端部をリアクター１の頂部２ｂのガス出口５に接続し、且つ上端部をガス分離槽１９の底部を貫通させて該ガス分離槽１９内部の有機性排水１０ａの水面より上方に開口させるようにして取り付けたガス取出管で、リアクター１内で発生して該ガス取出管２３を通してガス分離槽１９に導かれるガス１８と、溶解槽７より加圧ガスライン２１を通してガスリフト管２０の下端部に導かれた後、該ガスリフト管２０内を上昇してガス分離槽１９に達した排気ガス１７が、共にガス分離槽１９の頂部に設けたガス出口２４より、図示しない減圧弁を備えた排ガスラインを通して回収できるようにしてある。その他の構成は、図３に示したものと同様であり、同一のものには同一符号が付してある。
【００１５】
有機性排水１０は、従来と同様に０．５〜０．７ＭＰａに加圧された状態で排水供給部より排水供給ライン９を通して溶解槽７に送られ、該溶解槽７における加圧条件の下でコンプレッサー１２より加圧空気送給ライン１１を通して送給される加圧空気１３が吹き込まれて溶存酸素濃度が高められた有機性排水１０ａとされた後、高酸素濃度排水供給ライン８を通してリアクター１に送られる。該リアクター１に送られた有機性排水１０ａは、排水入口３より処理水取出口４に向かう間に、該有機性排水１０ａの上昇流に伴って流動する微生物付着担体６と接触させられることにより、十分な酸素の存在の下で有機成分が酸化分解され、該酸化分解により清浄化された処理水１６は、処理水取出口４より処理水取出ライン１４を通して回収されるようになる。この際、溶解槽７より加圧ガスライン２１を通してガスリフト管２０の下端部に導かれた排気ガス１７は、ガスリフト管２０の下端部の内部に侵入している有機性排水１０ａや微生物付着担体６に比して、その比重がきわめて小さいため、ガスリフト管２０内を急速に上昇させられ、この排気ガス１７のガスリフト管２０内における急速な上昇に伴うガスリフトポンプ効果により、ガスリフト管２０の下端部より有機性排水１０ａ及び微生物付着担体６がガス分離槽１９まで汲み上げられる。ガス分離槽１９まで汲み上げられた有機性排水１０ａ及び微生物付着担体６は、ガス分離槽１９内で排気ガス１７と分離されて比重が大きくなるため、自重により排水循環ライン２２を通して溶解槽７へ導かれる。該溶解槽７内へ導かれた有機性排水１０ａ及び微生物付着担体６は、排水供給ライン９を通して溶解槽７へ新たに供給される有機性排水１０に混入されると共に、加圧空気送給ライン１１を通して送給される加圧空気１３が吹き込まれて再び溶存酸素濃度が高められ、しかる後、高酸素濃度排水供給ライン８を通して排水入口３よりリアクター底部２ａまで戻され、これにより、ガスリフト管２０の下端部よりも下方となるリアクター１内の下部の領域Ａでは、下端部から上方に向かった後、ガスリフト管２０、ガス分離槽１９、排水循環ライン２１、溶解槽７、高酸素濃度排水供給ライン８を経由して再びリアクター１の下端部に戻される有機性排水１０ａと微生物付着担体６の循環流が生じさせられ、このため有機性排水１０ａと微生物付着担体６の強い流動接触状態が形成される。一方、ガスリフト管２０の下端部よりも上方で且つ処理水取出口４よりも下方となる領域Ｂでは、排水供給部より供給される処理対象水量、すなわち、上記溶解槽７に新たに供給される有機性排水１０の量に相当する量の有機性排水１０ａが下方から上方に通過するのみで、緩やかな流動状態となる。
【００１６】
このように、従来は大気中に放出していた溶解槽７での有機性排水１０ａに対する未溶解成分である排気ガス１７を利用して、リアクター１内の領域Ａと溶解槽７との間に有機性排水１０ａの循環流を積極的に生じさせることができるため、リアクター１内にて有機性排水１０ａと微生物付着担体６の流動状態を作り出すのに必要な高い上昇流速を生じさせるための循環ポンプの如き外部動力は不要となり、又、上記有機性排水１０ａの循環流に伴って微生物付着担体６も循環させることができることから、微生物付着担体６にかかる負荷を均一化することができて、従来に比してより高負荷の運転が可能となると共に、余剰増殖微生物の発生を抑制して余剰汚泥発生量を削減できる。更に、循環の途中で微生物付着担体６同士が接触することにより、過剰に肥厚した微生物膜が剥離されるので、特別な剥離、分離装置は不要となる。
【００１７】
更に、ガスリフト管２０よりも上方で且つ処理水取出口より下方の領域Ｂでは、流動状態を緩やかなものとすることができるので、循環ポンプ等の外部動力によって微生物付着担体６に必要な流動状態、すなわち、高い上昇流速を創出する場合に比して、処理水取出口４より微生物付着担体６が流出する虞を少なくすることができる。
【００１８】
更に又、リアクター１内の領域Ａと溶解槽７との間を循環する上記有機性排水１０ａは、溶解槽７を通過する毎に加圧空気１３が吹き込まれて溶存酸素濃度が高められるので、有機性排水１０の単位量当りの酸素供給量を増加させることができ、このため処理すべき有機性排水１０のＢＯＤ量が大きい場合にも、その処理を行うことが可能となる。
【００１９】
次に、図２は本発明の実施の他の形態を示すもので、図１に示した加圧流動床方式排水処理装置と同様の構成において、リアクター１の外側に設けていた溶解槽７を、リアクター１内に配置して、その下端をリアクター１の内底部に一体に設け、且つガス分離槽１９と溶解槽７内とを下降管２６で連通させた構成としたものである。
【００２０】
すなわち、図１に示した場合と同様に、上部側壁に処理水取出口４を設け、又、上方位置のガス分離槽１９に接続したガスリフト管２０が頂部２ｂを貫通して下端部を上記処理水取出口４より所要寸法低い位置に達するように配設してあるリアクター１内に、溶解槽７を収納し、該リアクター１の中央部分に上下方向に配置した溶解槽７の下端をリアクター１の内底面に一体に組付けて、リアクター１の底部に接続した加圧空気供給ライン１１を介してコンプレッサ１２からの加圧空気１３を下方より供給できるようにし、且つ該溶解槽７の上端部に、図示しない外部の排水供給部より加圧状態で供給される有機性排水１０を導く排水供給ライン９を、リアクター１の側壁を貫通させて接続すると共に、溶解槽７の下端部の周方向所要間隔位置に高酸素濃度排水出口２５を設けて、排水供給ライン９を通して溶解槽７内に導いた有機性排水１０に、溶解槽７内にて加圧空気１３を吹き込むことにより溶存酸素濃度の高められた有機性排水１０を、高酸素濃度排水出口２５を通してリアクター１の底部２ａ付近に放出できるようにしてある。更に、溶解槽７の頂部と上記ガスリフト管２０の下端部とを加圧ガスライン２１にて接続して、溶解槽７の加圧条件下においても有機性排水１０中に溶解せずに残る排気ガス１７を、上記加圧ガスライン２１を通してガスリフト２０管の下端部に導くようにしてあり、更に又、ガス分離槽１９の底部に接続した下降管２６を、リアクター１の頂部２ｂ及び溶解槽７の頂部を貫通して該溶解槽７内に挿入し、該下降管２６の下端を有機性排水１０中に没入させるように配設してある。
【００２１】
その他、図１に示したものと同一のものには同一符号が付してある。
【００２２】
本実施の形態によれば、図１に示す実施の形態と同様に０．５〜０．７ＭＰａに加圧された状態で排水供給部より排水供給ライン９を通して有機性排水１０を溶解槽７に供給すると、該有機性排水１０は、該溶解槽７内にて加圧空気送給ライン１１を通して送給される加圧空気１３が吹き込まれて溶存酸素濃度が高い有機性排水１０ａとされた後、高酸素濃度排水出口２５を通してリアクター１の底部２ａ付近に放出され、リアクター１内を上昇して処理水取出口４に向かう間に、該有機性排水１０ａの上昇流に伴って流動する微生物付着担体６と接触させられることにより、十分な酸素の存在の下で有機成分が酸化分解され、該酸化分解により清浄化された処理水１６は、処理水取出口４より処理水取出ライン１４を通して回収されるようになる。この際、溶解槽７より加圧ガスライン２１を通してガスリフト管２０の下端部に導かれた排気ガス１７によるガスリフトポンプ効果によってガスリフト管２０の下端部より有機性排水１０ａ及び微生物付着担体６がガス分離槽１９まで汲み上げられ、該汲み上げられた有機性排水１０ａ及び微生物付着担体６は、ガス分離槽１９内で排気ガス１７と分離された後、自重により下降管２６を通して溶解槽７へ導かれ、排水供給ライン９を通して溶解槽７へ新たに供給される有機性排水１０に混入されると共に、再び加圧空気１３が吹き込まれて溶存酸素濃度が高められ、しかる後、高酸素濃度排水出口２５よりリアクター１の底部２ａ付近の下端部まで戻される。これにより、図１の実施の形態と同様に、ガスリフト管２０の下端部よりも下方となるリアクター１内の下部の領域Ａでは、下端部から上方に向かった後、ガスリフト管２０、ガス分離槽１９、下降管２６、溶解槽７を経由して再びリアクター１の下端部に戻される有機性排水１０ａと微生物付着担体６の循環流が生じさせられ、このため有機性排水１０ａと微生物付着担体６の強い流動接触状態が形成され、一方、ガスリフト管２０の下端部よりも上方で且つ処理水取出口４よりも下方となる領域Ｂでは、排水供給部より供給される処理対象水量に相当する量の有機性排水１０ａが下方から上方に通過するのみで、緩やかな流動状態となる。
【００２３】
よって、本実施の形態によっても上記実施の形態と同様な効果を得ることができ、更に、溶解槽７とリアクター１を一体としてあるため、装置をコンパクトなものとすることができる。
【００２４】
なお、本発明は上記実施の形態のみに限定されるものではなく、たとえば、ガスリフト管２０の下端位置は図示より上方位置としてもよいこと、その他本発明の要旨を逸脱しない範囲内において種々変更を加え得ることは勿論である。
【００２５】
【発明の効果】
以上述べた如く、本発明の加圧流動床方式排水処理装置によれば、底部に排水入口を設け且つ上部側壁に処理水取出口を設けて内部に流動層を形成するようにして微生物付着担体を収納してなるリアクター内に、頂部を貫通して上記処理水取出口よりも所要寸法下方の位置へ達するように下方に延びるようにガスリフト管を配し、該ガスリフト管の上端部をガス分離槽に連結し、上記リアクターの排水入口に、処理すべき有機性排水に加圧下で加圧空気を吹き込むことにより溶存酸素濃度を高めた有機性排水を供給できるようにした溶解槽を接続し、且つ上記ガスリフト管の下端部に、上記溶解槽の排気ガスを導くための加圧ガスラインを接続し、更に、上記ガス分離槽の下端部に一端部を接続した排水循環ラインの他端部を、上記溶解槽の頂部に接続してなり、上記溶解槽からガスリフト管に導入される排気ガスによるガスリフトポンプ効果によりリアクター内の微生物付着担体及び有機性排水をガスリフト管を通してガス分離槽に汲み上げ、該汲み上げられた微生物付着担体及び有機性排水を、自重により上記排水循環ライン、溶解槽を経由してリアクターの排水入口へ循環させるようにした構成としてあるので、従来は大気中に放出していた溶解槽での有機性排水に対する未溶解成分である排気ガスを利用して、リアクターの下部の領域と溶解槽との間に積極的に有機性排水の循環流を生じさせることができるため、リアクター内に内部循環を生じさせるための循環ポンプの如き外部動力は不要とすることができること、上記有機性排水の循環流に伴って微生物付着担体も循環させることができることから、微生物付着担体にかかる負荷を均一化することができて、従来に比してより高負荷の運転が可能となること、余剰増殖微生物の発生を抑制して余剰汚泥発生量を削減でき、更に、循環の途中で微生物付着担体同士が接触することにより、過剰に肥厚した微生物膜が剥離されて、特別な剥離、分離装置は不要とすることができること、ガスリフト管の下端部よりも上方で且つ処理水取出口より下方の領域では、流動状態を緩やかなものとすることができるため、循環ポンプ等の外部動力によって微生物付着担体の流動状態を創出する場合に比して、処理水取出口より微生物付着担体が流出する虞を少なくすることができること、上記有機性排水の循環は、溶解槽を経由して行われ、該溶解槽を通過する毎に加圧空気が吹き込まれて酸素が供給されるため、有機性排水の単位量当りに対する酸素供給量を従来に比して増加させることができて、よりＢＯＤ量の大きな有機性排水の処理が可能になること、等の優れた効果を発揮することができ、又、上部側壁に処理水取出口を設けて内部に流動層を形成するようにして微生物付着担体を収納してなるリアクター内に、下端部に高酸素濃度排水出口を有する溶解槽を上下方向に配して、その下端をリアクター内底部に一体に組み付け、該溶解槽の上端部に上記リアクターの外部より処理すべき有機性排水の供給ラインを接続すると共に、下端部に加圧空気の送給ラインを接続して、溶解槽内の処理すべき有機性排水に加圧下で加圧空気を吹き込むことにより溶存酸素濃度を高めた有機性排水を上記高酸素濃度排水出口より上記リアクターの下端部に供給できるようにし、且つ上記リアクター内に、頂部を貫通して上記処理水取出口よりも所要寸法下方の位置へ達するように下方に延びるようにガスリフト管を配して、該ガスリフト管の下端部と、上記溶解槽内の上端とを加圧ガスラインを介して接続すると共に、該ガスリフト管の上端部をガス分離槽に接続し、更に上記ガス分離槽の底部に接続した下降管を、リアクターの頂部及び溶解槽の頂部を貫通させて、下端部を該溶解槽内の有機性排水中に没入させ、上記溶解槽からガスリフト管に入る排気ガスによるガスリフトポンプ効果によりリアクター内の微生物付着担体及び有機性排水をガスリフト管を通してガス分離槽に汲み上げ、該汲み上げられた微生物付着担体及び有機性排水を、自重により上記下降管、溶解槽を経由してリアクターの下端部へ循環させるようにした構成とすることにより、溶解槽の下端部からリアクターの下端部に供給された有機性排水と微生物付着担体が上昇してガスリフト管内を汲み上げられるため、ガスリフト管の下端部よりも下方となるリアクター内の下部の領域に、ガスリフト管、ガス分離槽、下降管、溶解槽を経由して再びリアクターの下端部に戻る有機性排水と微生物付着担体の循環流を形成させることができ、装置をコンパクトなものとすることができるという優れた効果を発揮する。
【図面の簡単な説明】
【図１】本発明の加圧流動床方式排水処理装置の実施の一形態を示す概要図である。
【図２】本発明の実施の他の形態を示す概要図である。
【図３】従来の加圧流動床方式排水処理装置の一例を示す概要図である。
【符号の説明】
１リアクター
２ａ底部
２ｂ頂部
３排水入口
４処理水取出口
６微生物付着担体
７溶解槽
９排水供給ライン
１０，１０ａ有機性排水
１１加圧空気送給ライン
１３加圧空気
１６処理水
１７排気ガス
１９ガス分離槽
２０ガスリフト管
２１加圧ガスライン
２２排水循環ライン
２５高酸素濃度排水出口
２６下降管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressurized fluidized bed wastewater treatment apparatus for decomposing organic components in organic wastewater such as sewage and industrial wastewater by microorganisms of a microorganism adhesion carrier housed in a pressurized fluidized reactor.
[0002]
[Prior art]
Treatment methods for sewage and industrial wastewater, such as wastewater from the food production field, alcohol production field, paper pulp production field, chemical / petrochemical field, and organic wastewater such as livestock, waste leachate, human waste, anaerobic water As one example, a microorganism-adhering carrier formed by supporting aerobic microorganisms on a particulate carrier such as fine sand to form a microbial film on the surface is filled into a reactor, and organic wastewater is flowed upward into the reactor. The aerobic fluidized bed system is used in which the microorganism-adhering carrier is fluidized by passing water downward, and the aerobic microorganisms supported on the flowing microorganism-adhering carrier decompose and remove organic substances in the organic waste water. There is a wastewater treatment device.
[0003]
However, when biological treatment of organic matter in organic wastewater is performed, it is usually necessary to provide dissolved oxygen at a weight ratio of 0.5 to 1.0 or more with respect to the amount of organic matter to be treated, that is, the amount of BOD. On the other hand, in the above-described aerobic fluidized bed wastewater treatment equipment, oxygen was dissolved in the organic wastewater to be treated under atmospheric pressure. Therefore, even if pure oxygen gas was blown in, the dissolved oxygen was obtained. The oxygen concentration is low, and therefore, there is a problem that oxygen gas must be blown after diluting the organic waste water, leading to an increase in the size of the apparatus. By bringing the fluidized bed reactor filled with the supported microorganism-adhering carrier into a pressurized state, the dissolved oxygen concentration in the organic wastewater to be treated in the reactor can be increased. And, wastewater treatment device PFBC scheme to enhance the processing capability of the aerobic treatment have been developed. In this type of pressurized fluidized bed wastewater treatment device, an oxygen-containing gas (mainly air), which is essential for the treatment reaction, is directly injected into the pressurized reactor, thereby allowing the pressurized reactor to enter the pressurized reactor. A method of dissolving oxygen in organic waste water (Japanese Patent Laid-Open No. 4-40295) and a pressurized dissolution tank in the front stage of the reactor are added to the organic waste water to be treated in the dissolution tank. A method in which oxygen is dissolved in advance under pressure, and then the organic waste water in which the oxygen is dissolved is supplied to the reactor in a pressurized state (Japanese Patent Laid-Open Nos. 54-81660 and 56-1000069). The latter has been proposed, and the latter is particularly excellent in terms of oxygen dissolution efficiency.
[0004]
That is, the pressurized fluidized bed wastewater treatment apparatus of the type in which a dissolution tank is provided in the previous stage of the reactor is provided with a drainage inlet 3 at the bottom 2a and treated water on the upper side wall as schematically shown in FIG. A microorganism-adhering carrier 6 is provided in which an outlet 4 is provided and a gas outlet 5 is provided at the top 2b, and an aerobic microorganism film is formed on the surface by supporting an aerobic microorganism on a particulate carrier such as fine sand. A reactor 1 formed by filling is formed, and a lower end portion of a dissolution tank 7 which is a cylindrical pressurization container extending in the vertical direction disposed outside the reactor 1 is provided at the drainage inlet 3 of the reactor 1 with a high oxygen concentration. Connected via a drainage supply line 8, and the dissolution tank 7 is an organic drainage supplied at a pressure from a drainage supply unit provided with a pump (not shown) at a top, for example, 0.5 to 0.7 MPa. Drain supply line 9 leading 10 As well as being connected to the bottom, the compressor 12 is connected via the pressurized air feed line 11 so that the organic waste water 10 is sent from the waste water supply part to the dissolution tank 7 through the waste water supply line 9 in a pressurized state. Then, compressed air consisting of about 80% nitrogen and about 20% oxygen is blown into the dissolution tank 7 by blowing pressurized air 13 fed from the compressor 12 through the pressurized air feed line 11. The oxygen concentration in the organic waste water 10 can be increased by dissolving almost the entire amount of oxygen 13 and a part of nitrogen, and a pressure reducing valve is provided at the treated water outlet 4 of the reactor 1. 15 is connected to the treated water take-out line 14 so that the organic waste water 10a whose dissolved oxygen concentration is increased in the dissolving tank 7 can be passed through the high oxygen concentration waste water supply line 8 in a pressurized state. The microorganism-adhering carrier 6 is caused to flow by the upward flow of the organic wastewater 10a directed from the wastewater inlet 3 of the reactor 1 to the treated water outlet 4 while being flown through the microorganisms in the microorganism-adhering carrier 6a. The organic component is oxidatively decomposed in the presence of sufficient oxygen, and then the treated water 16 that has been decomposed and purified by the organic component is caused to overflow from the treated water outlet 4 to be treated with a treated water extraction line 14. It can be recovered through.
[0005]
Note that the nitrogen-based exhaust gas 17 remaining without being dissolved in the organic waste water 10a even under the pressurizing condition in the dissolution tank 7 enters the atmosphere from the top of the dissolution tank 7 through a discharge line with a pressure reducing valve (not shown). It is supposed to be released. The gas 18 generated inside the reactor 1 is recovered through a gas discharge line equipped with a pressure reducing valve (not shown) connected to the gas outlet 5 of the reactor 1.
[0006]
[Problems to be solved by the invention]
However, in the conventional pressurized fluidized bed wastewater treatment apparatus as shown in FIG. 3, the energy for causing the microorganism-adhering carrier 6 to flow in the reactor 1 flows from the wastewater inlet 3 to the treated water outlet 4 in the reactor 1. There is only a rising flow of the organic waste water 10a, and if only the drainage amount of the organic waste water 10 to be treated is used, the rising flow formed in the reactor 1 is weak and the flow of the microorganism-adhering carrier 6 may be insufficient. For this reason, in order to secure the necessary ascending flow rate, that is, the flow energy of the microorganism-adhering carrier 6, there is a problem that an external auxiliary device such as a circulation pump must be provided outside the reactor 1, and thus power consumption is reduced. There is a problem of growing. Even if the external auxiliary device is provided, the flow of the microorganism-adhering carrier 6 in the reactor 1 is plug flow, so that the microorganism-adhering carrier 6 located in the lower part near the drainage inlet 3 is very much. While a high load is applied, the microbial adhesion carrier 6 on the upper part of the reactor 1 is subjected to a low load, so that the potential holding ability of the microorganisms supported on the microbial adhesion carrier 6 cannot be fully utilized, and excessive growth is achieved. There is also a problem that the amount of microorganisms increases. Further, when the microbial film of the microbial adhesion carrier 6 gradually thickens, the apparent specific gravity becomes small and there is a risk that it will flow out of the reactor 1. Means for separating and separating the membrane from the particulate carrier carrying the membrane, for example, a pump for taking out the microorganism-adhering carrier 6 from the reactor 1 and a stirrer for separating the thickened microorganism membrane by stirring the microorganism-adhering carrier 6 However, there is no practical proposal in terms of equipment cost, power consumption, efficiency, and the like. Furthermore, when an ascending flow rate necessary for fluid contact between the microorganism-adhering carrier 6 and the organic waste water 10a in the reactor 1 is secured by the external auxiliary device, the more the rising flow rate is increased, the more the microorganism-adhering carrier 6 flows out of the system. As a result, there is a problem that processing capacity may be lowered.
[0007]
Furthermore, even if it is pressurized to around 500 kPa in the dissolution tank 7, the amount of oxygen that can be dissolved in the organic waste water 10 is up to about five times the amount of oxygen that can be dissolved under atmospheric pressure. Therefore, there is a possibility that the required dissolved oxygen concentration may not be sufficiently satisfied for the organic waste water 10 having a large BOD amount. For this reason, it is desired to further increase the oxygen supply amount.
[0008]
Therefore, the present invention can efficiently circulate the microorganism-adhering carrier in the reactor without the need for an external auxiliary device, and can eliminate the uneven load on the microorganism-adhering carrier to be used. It is intended to provide a pressurized fluidized bed wastewater treatment device that can peel and remove thickened microbial membranes, can further increase the oxygen supply amount, and can treat organic wastewater with a large BOD amount. Is.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a reactor in which a microorganism-adhering carrier is accommodated by providing a drainage inlet at the bottom and a treated water outlet at the upper side wall to form a fluidized bed inside. A gas lift pipe extending through the top so as to reach a position below a required dimension from the treated water outlet, and connecting an upper end of the gas lift pipe to a gas separation tank. Connected to the drainage inlet is a dissolution tank capable of supplying organic wastewater whose concentration of dissolved oxygen is increased by blowing pressurized air into the organic wastewater to be treated, and is connected to the lower end of the gas lift pipe. , Connect a pressurized gas line for guiding the exhaust gas of the dissolution tank, and connect the other end of the drainage circulation line with one end connected to the lower end of the gas separation tank to the top of the dissolution tank And above The microbial adhesion carrier and organic wastewater in the reactor are pumped up to the gas separation tank through the gas lift pipe due to the gas lift pump effect of the exhaust gas introduced from the demolition tank into the gas lift pipe, and the microbial adhesion carrier and organic wastewater thus pumped up by its own weight. Is configured to circulate to the drainage inlet of the reactor via the drainage circulation line and dissolution tank.
[0010]
The organic wastewater is supplied from the bottom drainage inlet into the reactor after being pressurized into the dissolution tank and compressed into the organic wastewater in which the dissolved oxygen concentration is increased. While going to the treated water outlet, the organic component is contacted with the microorganism-adhering carrier flowing along with the upward flow of the organic waste water, and the organic components are oxidatively decomposed in the presence of sufficient oxygen, and cleaned by the oxidative decomposition. The treated water is collected from the treated water outlet. At this time, the exhaust gas led from the dissolution tank to the lower end of the gas lift pipe through the pressurized gas line is rapidly raised in the gas lift pipe, and due to the gas lift pump effect accompanying the rapid rise of the exhaust gas, Organic drainage and microbial adhesion carrier are pumped up to the gas separation tank from the lower end. The organic waste water and the microorganism adhesion carrier pumped up in the gas separation tank are separated from the exhaust gas in the gas separation tank, led to the dissolution tank through the drainage circulation line by its own weight, and newly supplied in the dissolution tank. In addition to being mixed into the organic waste water, the compressed air is blown again to return to the lower end of the reactor in a state where the dissolved oxygen concentration is increased. As a result, the lower region in the reactor below the lower end of the gas lift pipe is directed upward from the lower end of the reactor, and then passes through the gas lift pipe, the gas separation tank, the drain circulation line, and the dissolution tank. A circulation flow of the organic waste water and the microorganism adhesion carrier returning to the lower end of the reactor is generated, and thus a strong fluid contact state between the organic waste water and the microorganism adhesion carrier is formed. On the other hand, in the region that is above the lower end of the gas lift pipe and below the treated water outlet, only a quantity of organic wastewater corresponding to the amount of water to be treated passes from below to above, and a gentle flow state is obtained. Become.
[0011]
In addition, a dissolution tank having a high oxygen concentration drainage outlet at the lower end is provided in a vertical direction in a reactor in which a treated water outlet is provided on the upper side wall and a fluidized bed is formed therein to store a microorganism-adhering carrier. The lower end of the reactor is integrally assembled to the bottom of the reactor, and the organic waste water supply line to be treated from the outside of the reactor is connected to the upper end of the dissolution tank, and pressurized air is supplied to the lower end. Connect the line to the organic wastewater to be treated in the dissolution tank and blow the pressurized air under pressure to increase the dissolved oxygen concentration from the high oxygen concentration drainage outlet to the lower end of the reactor. In the reactor, a gas lift pipe is arranged in the reactor so as to extend downward through the top so as to reach a position below the treated water outlet by a required dimension. And a lower pipe connected to the gas separation tank at the upper end of the gas lift pipe, and further connected to the bottom of the gas separation tank, The top of the reactor and the top of the dissolution tank are penetrated, the lower end is immersed in the organic waste water in the dissolution tank, and the microorganism adhesion carrier in the reactor by the gas lift pump effect by the exhaust gas entering the gas lift pipe from the dissolution tank In addition, the organic waste water is pumped up to the gas separation tank through the gas lift pipe, and the microbial adhesion carrier and the organic waste water pumped up are circulated to the lower end of the reactor through the downcomer and dissolution tank by their own weight. As a result, the organic waste water and the microorganism-adhering carrier supplied from the lower end of the dissolution tank to the lower end of the reactor rise and are pumped up in the gas lift pipe. Therefore, the organic wastewater and the microorganism adhesion carrier that returns to the lower end of the reactor again through the gas lift pipe, gas separation tank, downcomer, and dissolution tank in the lower area of the reactor below the lower end of the gas lift pipe Therefore, the apparatus can be made compact.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 shows an embodiment of a pressurized fluidized bed wastewater treatment apparatus of the present invention. Like the one shown in FIG. 3, a drainage inlet 3 is provided at the bottom and a treated water outlet 4 is provided at the upper side wall. A gas separation tank 19 is installed at a position above the reactor 1 in the pressurized fluidized bed wastewater treatment apparatus that is configured to accommodate the microorganism adhesion carrier 6 so as to form a fluidized bed therein, The lower end of the gas lift pipe 20 inserted through the bottom of the gas separation tank 19 and inserted into the upper end is penetrated through the top 2b of the reactor 1 to a depth that reaches a position that is lower than the treated water outlet 4 by a required dimension. And the upper end of the dissolution tank 5 disposed outside the reactor 1 and the lower end of the gas lift pipe 20 are connected by a pressurized gas line 21 penetrating the side wall of the reactor 1. Addition of dissolution tank 7 A gas lift is achieved by introducing the nitrogen-based exhaust gas 17 that remains undissolved in the organic waste water 10 under the conditions to the lower end of the gas lift pipe 20 through the pressurized gas line 21 and raises the gas lift pipe 20. Further, a pump effect is generated, and the lower end of the gas separation tank 19 and the top of the dissolution tank 7 are connected via a drainage circulation line 22, and the gas lift pump effect passes through the gas lift pipe 20 from the reactor 1. The organic waste water 10 a pumped up to the gas separation tank 19 can be led to the dissolution tank 7 through the drain circulation line 22.
[0014]
23 has a lower end connected to the gas outlet 5 of the top 2b of the reactor 1, and an upper end penetrating the bottom of the gas separation tank 19 to open above the water surface of the organic waste water 10a inside the gas separation tank 19. The gas outlet pipe attached in this manner is generated in the reactor 1 and led to the gas separation tank 19 through the gas outlet pipe 23, and the lower end of the gas lift pipe 20 from the dissolution tank 7 through the pressurized gas line 21. Then, the exhaust gas 17 that has risen in the gas lift pipe 20 and reaches the gas separation tank 19 is exhausted from the gas outlet 24 provided at the top of the gas separation tank 19 with an unillustrated pressure reducing valve. It can be collected through the line. Other configurations are the same as those shown in FIG. 3, and the same components are denoted by the same reference numerals.
[0015]
The organic wastewater 10 is sent to the dissolution tank 7 through the drainage supply line 9 from the drainage supply part in a state of being pressurized to 0.5 to 0.7 MPa as in the conventional case, and under the pressurization condition in the dissolution tank 7. Then, after the pressurized air 13 fed from the compressor 12 through the pressurized air feeding line 11 is blown into the organic drainage 10a having the increased dissolved oxygen concentration, the reactor 1 is passed through the high oxygen concentration drainage supply line 8. Sent to. The organic wastewater 10a sent to the reactor 1 is brought into contact with the microorganism-adhering carrier 6 flowing along with the upward flow of the organic wastewater 10a while going from the drainage inlet 3 to the treated water outlet 4. The organic components are oxidatively decomposed in the presence of sufficient oxygen, and the treated water 16 purified by the oxidative decomposition is recovered from the treated water outlet 4 through the treated water extraction line 14. At this time, the exhaust gas 17 led from the dissolution tank 7 to the lower end of the gas lift pipe 20 through the pressurized gas line 21 is introduced into the organic waste water 10 a and the microorganism adhesion carrier 6 that have entered the lower end of the gas lift pipe 20. Since the specific gravity is extremely small as compared with the gas lift pipe 20, the gas lift pipe 20 can be rapidly raised. Due to the gas lift pump effect accompanying the rapid rise of the exhaust gas 17 in the gas lift pipe 20, the lower end of the gas lift pipe 20. The organic waste water 10a and the microorganism adhesion carrier 6 are pumped up to the gas separation tank 19. Since the organic waste water 10a and the microorganism adhesion carrier 6 pumped up to the gas separation tank 19 are separated from the exhaust gas 17 in the gas separation tank 19 and increase in specific gravity, they are led to the dissolution tank 7 through the drain circulation line 22 by their own weight. It is burned. The organic wastewater 10a and the microorganism adhesion carrier 6 introduced into the dissolution tank 7 are mixed into the organic wastewater 10 that is newly supplied to the dissolution tank 7 through the wastewater supply line 9, and a pressurized air supply line. The pressurized air 13 fed through 11 is blown to increase the dissolved oxygen concentration again, and then returned to the reactor bottom 2a from the drainage inlet 3 through the high oxygen concentration drainage supply line 8, whereby the gas lift pipe 20 In the lower region A in the reactor 1 which is lower than the lower end of the gas, the gas lift pipe 20, the gas separation tank 19, the drainage circulation line 21, the dissolution tank 7, and the high oxygen concentration drainage supply are provided after going upward from the lower end. A circulation flow of the organic waste water 10a and the microorganism-adhering carrier 6 which are returned to the lower end of the reactor 1 again via the line 8 is generated, and thus the organic waste water 10a and the microorganisms are generated. Strong fluid contact is formed of Chaku担体 6. On the other hand, in the region B that is above the lower end portion of the gas lift pipe 20 and below the treated water outlet 4, the amount of water to be treated supplied from the drainage supply unit, that is, newly supplied to the dissolution tank 7. The amount of the organic waste water 10a corresponding to the amount of the organic waste water 10 passes only from the lower side to the upper side, and a gentle fluid state is obtained.
[0016]
As described above, the exhaust gas 17 that is an undissolved component for the organic waste water 10a in the dissolution tank 7 that has been released to the atmosphere in the past is used to provide a space between the region A in the reactor 1 and the dissolution tank 7. Since the circulating flow of the organic waste water 10a can be positively generated, the circulation for generating a high ascending flow velocity necessary for creating the flow state of the organic waste water 10a and the microorganism adhesion carrier 6 in the reactor 1 is achieved. External power such as a pump is not required, and the microorganism-adhering carrier 6 can be circulated along with the circulating flow of the organic waste water 10a, so that the load on the microorganism-adhering carrier 6 can be made uniform, As compared with the conventional case, it is possible to operate at a higher load, and it is possible to reduce the generation amount of surplus sludge by suppressing the generation of surplus propagation microorganisms. In addition, since the microorganism film that is excessively thick is peeled off when the microorganism-adhering carriers 6 come in contact with each other during the circulation, a special peeling / separating device is not required.
[0017]
Furthermore, in the region B above the gas lift pipe 20 and below the treated water outlet, the flow state can be made gentle, so that the flow state necessary for the microorganism-adhering carrier 6 by external power such as a circulation pump or the like. That is, compared with the case where a high ascending flow rate is created, the possibility that the microorganism-adhering carrier 6 flows out from the treated water outlet 4 can be reduced.
[0018]
Furthermore, since the organic waste water 10a circulating between the region A in the reactor 1 and the dissolution tank 7 passes through the dissolution tank 7, the pressurized air 13 is blown to increase the dissolved oxygen concentration. The amount of oxygen supply per unit amount of the organic waste water 10 can be increased. Therefore, even when the amount of BOD of the organic waste water 10 to be treated is large, the treatment can be performed.
[0019]
Next, FIG. 2 shows another embodiment of the present invention. In the same configuration as the pressurized fluidized bed wastewater treatment apparatus shown in FIG. 1, a dissolution tank 7 provided outside the reactor 1 is provided. The reactor 1 is disposed in the reactor 1, and the lower end thereof is integrally provided on the inner bottom of the reactor 1, and the gas separation tank 19 and the dissolution tank 7 are communicated with each other through a downcomer 26.
[0020]
That is, as in the case shown in FIG. 1, the treated water outlet 4 is provided in the upper side wall, and the gas lift pipe 20 connected to the gas separation tank 19 in the upper position passes through the top 2b and the lower end is treated as described above. The dissolution tank 7 is accommodated in the reactor 1 arranged so as to reach a position lower in the required dimension than the water outlet 4, and the lower end of the dissolution tank 7 arranged in the vertical direction at the central portion of the reactor 1 is the reactor 1. The compressed air 13 from the compressor 12 can be supplied from below through the pressurized air supply line 11 connected to the bottom of the reactor 1 and the upper end of the dissolution tank 7. A drainage supply line 9 for guiding the organic drainage 10 supplied in a pressurized state from an external drainage supply unit (not shown) is connected through the side wall of the reactor 1 and the circumferential direction of the lower end of the dissolution tank 7 Required interval The high oxygen concentration drainage outlet 25 is provided in the organic tank 10, and the dissolved oxygen concentration is increased by blowing pressurized air 13 into the organic drainage 10 introduced into the dissolution tank 7 through the drainage supply line 9. The organic waste water 10 can be discharged near the bottom 2a of the reactor 1 through the high oxygen concentration drain outlet 25. Further, the top of the dissolution tank 7 and the lower end of the gas lift pipe 20 are connected by a pressurized gas line 21, and the exhaust gas remaining without being dissolved in the organic waste water 10 even under the pressurized condition of the dissolution tank 7. The gas 17 is led to the lower end of the gas lift 20 pipe through the pressurized gas line 21, and the downcomer pipe 26 connected to the bottom of the gas separation tank 19 is connected to the top 2 b of the reactor 1 and the dissolution tank 7. The lower end of the downcomer pipe 26 is disposed so as to be immersed in the organic waste water 10.
[0021]
In addition, the same components as those shown in FIG.
[0022]
According to the present embodiment, the organic waste water 10 is supplied to the dissolution tank 7 through the waste water supply line 9 from the waste water supply section in a state of being pressurized to 0.5 to 0.7 MPa as in the embodiment shown in FIG. When supplied, the organic waste water 10 is converted into an organic waste water 10a having a high dissolved oxygen concentration by blowing pressurized air 13 fed through the pressurized air feed line 11 in the dissolution tank 7. The microorganisms are discharged through the high oxygen concentration drainage outlet 25 to the vicinity of the bottom 2a of the reactor 1 and flow along with the upward flow of the organic drainage 10a while going up in the reactor 1 toward the treated water outlet 4 By contacting with the carrier 6, the organic component is oxidatively decomposed in the presence of sufficient oxygen, and the treated water 16 purified by the oxidative decomposition is recovered from the treated water outlet 4 through the treated water extraction line 14. To be It made. At this time, the organic waste water 10a and the microorganism-adhering carrier 6 are separated from the lower end of the gas lift pipe 20 by the gas lift pump effect by the exhaust gas 17 introduced from the dissolution tank 7 through the pressurized gas line 21 to the lower end of the gas lift pipe 20. The organic waste water 10a and the microorganism-adhered carrier 6 that have been pumped up to the tank 19 are separated from the exhaust gas 17 in the gas separation tank 19, and then guided to the dissolution tank 7 through the downcomer 26 by their own weight. In addition to being mixed into the organic wastewater 10 that is newly supplied to the dissolution tank 7 through the supply line 9, the pressurized air 13 is blown again to increase the dissolved oxygen concentration, and then the reactor is discharged from the high oxygen concentration drainage outlet 25. 1 is returned to the lower end near the bottom 2a. Thus, as in the embodiment of FIG. 1, in the lower region A in the reactor 1 below the lower end of the gas lift pipe 20, the gas lift pipe 20 and the gas separation tank are moved upward from the lower end. 19, a circulating flow of the organic waste water 10a and the microorganism-adhering carrier 6 that is returned to the lower end of the reactor 1 again via the downcomer 26 and the dissolution tank 7 is generated. On the other hand, in the region B that is above the lower end of the gas lift pipe 20 and below the treated water outlet 4, an amount corresponding to the amount of water to be treated supplied from the drainage supply unit Only when the organic waste water 10a passes from the lower side to the upper side, it becomes a gentle fluid state.
[0023]
Therefore, the present embodiment can provide the same effects as those of the above embodiment, and the apparatus can be made compact because the dissolution tank 7 and the reactor 1 are integrated.
[0024]
The present invention is not limited to the above-described embodiment. For example, the lower end position of the gas lift pipe 20 may be an upper position than illustrated, and various modifications may be made without departing from the scope of the present invention. Of course, it can be added.
[0025]
【The invention's effect】
As described above, according to the pressurized fluidized bed wastewater treatment apparatus of the present invention, a microorganism-adhering carrier is formed by providing a drainage inlet at the bottom and a treated water outlet at the upper side wall to form a fluidized bed inside. A gas lift pipe is disposed in the reactor containing the gas so as to extend downward through the top so as to reach a position below the required dimension of the treated water outlet, and gas separation is performed on the upper end of the gas lift pipe. Connected to the tank, and connected to the waste water inlet of the reactor was a dissolution tank that was able to supply organic waste water with increased dissolved oxygen concentration by blowing pressurized air into the organic waste water to be treated under pressure, A pressurized gas line for guiding the exhaust gas from the dissolution tank is connected to the lower end of the gas lift pipe, and the other end of the drainage circulation line is connected to the lower end of the gas separation tank. Of the above dissolution tank The microbial adhesion carrier and the organic waste water in the reactor are pumped up to the gas separation tank through the gas lift pipe by the gas lift pump effect by the exhaust gas introduced into the gas lift pipe from the lysis tank, and the microbial adhesion thus pumped up. Since the carrier and the organic wastewater are circulated to the reactor drainage inlet via the drainage circulation line and dissolution tank by their own weight, the organicity in the dissolution tank that has been released to the atmosphere in the past. By using exhaust gas, which is an undissolved component for wastewater, a circulation flow of organic wastewater can be positively generated between the lower area of the reactor and the dissolution tank, creating an internal circulation in the reactor. External power, such as a circulation pump, can be eliminated, and the microorganism-adhering carrier is also circulated along with the circulation flow of the organic waste water. Therefore, it is possible to make the load applied to the microorganism-adhering carrier uniform, and it is possible to operate at a higher load than before, and the amount of surplus sludge generated by suppressing the generation of surviving microorganisms. Furthermore, when the microorganism-adhering carriers come into contact with each other during the circulation, the excessively thickened microorganism film is peeled off, and a special peeling / separation device can be dispensed with, and the lower end of the gas lift pipe In the region above and below the treated water outlet, the flow state can be made gentle, so compared to the case where the flow state of the microorganism-adhering carrier is created by external power such as a circulation pump, It is possible to reduce the possibility that the microorganism-adhering carrier flows out from the treated water outlet, and the organic waste water is circulated through the dissolution tank, and pressurized air is passed through the dissolution tank. Since oxygen is supplied by blowing air, the amount of oxygen supply per unit amount of organic wastewater can be increased compared to the conventional amount, and organic wastewater with a larger BOD amount can be treated. In the reactor in which the microorganism-adhering carrier is accommodated in such a manner that a treated water outlet is provided in the upper side wall and a fluidized bed is formed inside, a lower end portion can be exhibited. A dissolution tank having a high oxygen concentration drainage outlet is arranged in the vertical direction, and its lower end is integrally assembled to the bottom of the reactor, and an organic wastewater supply line to be treated from the outside of the reactor at the upper end of the dissolution tank Connected to the lower end, a pressurized air supply line is connected to the organic wastewater to be treated in the dissolution tank, and pressurized air is blown into the organic wastewater under pressure to increase the dissolved oxygen concentration. The above high oxygen concentration A gas lift pipe is arranged so that it can be supplied from the water outlet to the lower end of the reactor and extends downward in the reactor so as to pass through the top and reach a position below the treated water outlet. The lower end of the gas lift pipe and the upper end of the dissolution tank are connected via a pressurized gas line, the upper end of the gas lift pipe is connected to a gas separation tank, and the gas separation tank A gas lift pump by exhaust gas that enters the gas lift pipe from the dissolution tank by letting the downcomer connected to the bottom through the top of the reactor and the top of the dissolution tank and immersing the lower end into the organic waste water in the dissolution tank As a result, the microbial adhesion carrier and the organic wastewater in the reactor are pumped up to the gas separation tank through the gas lift pipe, and the microbial adhesion carrier and the organic wastewater thus pumped up by their own weight. By adopting a structure that circulates to the lower end of the reactor via the downcomer and dissolution tank, the organic waste water and the microorganism adhesion carrier supplied from the lower end of the dissolution tank to the lower end of the reactor rise. Since the inside of the gas lift pipe is pumped up, the organic that returns to the lower end of the reactor again through the gas lift pipe, the gas separation tank, the downcomer, and the dissolution tank into the lower area of the reactor below the lower end of the gas lift pipe It is possible to form a circulating flow of the effluent wastewater and the microorganism-adhering carrier and to exhibit an excellent effect that the apparatus can be made compact.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an embodiment of a pressurized fluidized bed wastewater treatment apparatus of the present invention.
FIG. 2 is a schematic diagram showing another embodiment of the present invention.
FIG. 3 is a schematic view showing an example of a conventional pressurized fluidized bed wastewater treatment apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reactor 2a Bottom part 2b Top part 3 Drainage inlet 4 Treated water outlet 6 Microbe adhesion support 7 Dissolution tank 9 Drain supply line 10, 10a Organic waste water 11 Pressurized air supply line 13 Pressurized air 16 Treated water 17 Exhaust gas 19 Gas Separation tank 20 Gas lift pipe 21 Pressurized gas line 22 Drain circulation line 25 High oxygen concentration drain outlet 26 Downcomer pipe

Claims

A drainage inlet is provided at the bottom and a treated water outlet is provided on the upper side wall, and a fluidized bed is formed in the interior so that a microorganism-adhering carrier is accommodated in the reactor. Also, a gas lift pipe is arranged to extend downward so as to reach a position below the required dimension, the upper end of the gas lift pipe is connected to a gas separation tank, and the organic waste water to be treated is added to the waste water inlet of the reactor. Connected to a dissolution tank capable of supplying organic wastewater with a higher dissolved oxygen concentration by blowing pressurized air under pressure, and to the exhaust gas for introducing exhaust gas from the dissolution tank to the lower end of the gas lift pipe A pressure gas line is connected, and the other end of the drainage circulation line with one end connected to the lower end of the gas separation tank is connected to the top of the dissolution tank and introduced from the dissolution tank into the gas lift pipe. Exhausted The microbial adhesion carrier and organic wastewater in the reactor are pumped to the gas separation tank through the gas lift pipe by the gas lift pump effect by gas, and the microbial adhesion carrier and organic wastewater pumped up through the drainage circulation line and dissolution tank by their own weight. Then, a pressurized fluidized bed wastewater treatment device characterized by having a configuration in which it is circulated to the wastewater inlet of the reactor.

A dissolution tank having a high oxygen concentration drainage outlet at the lower end is arranged in the vertical direction in a reactor in which a treated water outlet is provided in the upper side wall and a fluidized bed is formed therein to store a microorganism adhesion carrier. The lower end of the reactor is integrally assembled with the bottom of the reactor, an organic waste water supply line to be treated is connected to the upper end of the dissolution tank from the outside of the reactor, and a pressurized air supply line is connected to the lower end. Organic wastewater with increased dissolved oxygen concentration can be supplied to the lower end of the reactor from the high oxygen concentration drainage outlet by connecting and blowing pressurized air under pressure into the organic wastewater to be treated in the dissolution tank In the reactor, a gas lift pipe is disposed so as to extend through the top so as to reach a position below a required dimension from the treated water outlet, and a lower end portion of the gas lift pipe. The upper end of the dissolution tank is connected via a pressurized gas line, the upper end of the gas lift pipe is connected to the gas separation tank, and the downcomer connected to the bottom of the gas separation tank is connected to the reactor. The top part and the top part of the dissolution tank are penetrated, the lower end part is immersed in the organic waste water in the dissolution tank, and the microorganism-adhering carrier and the organic substance in the reactor by the gas lift pump effect by the exhaust gas entering the gas lift pipe from the dissolution tank The microbial waste water is pumped up to the gas separation tank through the gas lift pipe, and the pumped microorganism adhering carrier and the organic waste water are circulated to the lower end of the reactor through the downcomer and dissolution tank by its own weight. A pressurized fluidized bed wastewater treatment apparatus characterized by that.