JP4573991B2

JP4573991B2 - Sewage treatment apparatus and treatment method

Info

Publication number: JP4573991B2
Application number: JP2000338040A
Authority: JP
Inventors: 栄一鈴木; 剛市成
Original assignee: Fujiclean Co Ltd
Current assignee: Fujiclean Co Ltd
Priority date: 2000-11-06
Filing date: 2000-11-06
Publication date: 2010-11-04
Anticipated expiration: 2020-11-06
Also published as: JP2002136984A

Description

【０００１】
【発明の属する技術分野】
本発明は、担体を用いた汚水処理に係り、特に、汚水を生物処理する微生物を着床させた担体を用いた汚水処理技術に関する。
【０００２】
【従来の技術】
従来、例えば一般家庭から排出される原汚水を浄化する汚水処理槽が知られている。かかる従来の汚水処理槽では、上部多孔板と下部多孔板で囲まれる担体充填領域に、例えば好気性微生物を着床させた一定量の担体が充填されている。また、この担体充填領域を生物処理領域（好気処理領域）と濾過領域とに区画するとともに連通部を介して両領域間の担体の移動を可能とする隔壁、槽内の底部からエアー（酸素）を供給する散気装置が設けられている。そして、散気装置によって槽内へエアーを供給することで汚水は隔壁のまわりを循環し、生物処理領域と濾過領域との間を流動する。この汚水循環の際、担体充填領域外への担体の流出が上部多孔板によって阻止される。
【０００３】
このような構成の汚水処理槽では、生物処理領域において担体を汚水とともに流動させることで、微生物によって汚水中の有機汚濁物質を分解（酸化や還元）する、いわゆる生物処理が行われる。また、生物処理で発生する被濾過物等を担体によって濾過する濾過処理が行われる。更に、濾過処理によって担体に捕捉された汚泥等をエアー流によって物理的に剥離させ、汚泥等を含む逆洗水を汚水処理槽から抜き出す逆洗処理が行われる。
【０００４】
【発明が解決しようとする課題】
上記従来の汚水処理槽では、隔壁の頂部よりも汚水の水面が高い場合に、例えば生物処理領域の汚水が隔壁を越えて濾過領域へ移動し、また濾過領域の汚水が連通部を介して生物処理領域に移動することで槽内の汚水が循環する。
ところが、隔壁の頂部よりも汚水の水面が低くなると、生物処理領域と濾過領域との間で汚水の循環は確立されなくなる。そして、生物処理時に汚水の循環が行われなくなると、生物処理領域と濾過領域との間の担体の円滑な移動が阻止され好適な処理が阻害されるという問題がある。また、逆洗処理時に汚水の循環が行われなくなると、逆洗自体を行うことができないという問題がある。そして、このような水面低下による問題は、例えば流量調整機能付き浄化槽のように、処理過程において水面が変動するような処理槽に特に顕著である。
【０００５】
水面が低下しても循環が行われるように隔壁の頂部および上部多孔部材を低水位線（Ｌ.Ｗ.Ｌ.）以下にすると、担体を充填できる領域容量を削減することになり、処理効率が悪くなる。そこで、本発明は、微生物を着床させた担体が充填された処理槽を有する汚水の処理装置において、被処理汚水の水面が変動した場合でも被処理汚水の循環を極力維持することで好適な処理を行う合理的な汚水処理技術を提供することを課題とする。
【０００６】
【課題を解決するための手段】
前記課題を解決するために、本発明の汚水の処理装置は、請求項１及び２に記載の通りに構成されている。また、本発明の汚水の処理方法は、請求項３及び４に記載の通りである。
【０００７】
請求項１に記載の汚水の処理装置において、処理槽内には微生物を着床させた担体が充填されている。この微生物としては、汚水中の有機性汚濁物質を好気分解する好気性微生物や嫌気分解する嫌気性微生物がある。また、処理槽内には複数の領域と、これら領域を区画する区画部材（隔壁）が設けられている。また、処理槽へエアーを供給する散気装置が設けられている。そして、散気装置から処理槽へエアーが供給されると、そのエアー流によって被処理汚水が区画部材を越えて領域間を循環する。更に、区画部材の頂部よりも水面が低下した被処理汚水を領域間において移動させる被処理汚水移動手段（開孔部）が設けられている。ここで本発明でいう「頂部」とは領域を区画する区画部材においてその高さが最も高い箇所をいう。これにより、被処理汚水の水面が低下した場合でも領域間を被処理汚水が移動し被処理汚水の循環が維持されることとなる。また、領域間における担体の円滑な移動が維持されることとなる。
なお、本発明でいう「被処理汚水移動手段」とは、水面が区画部材の頂部よりも低い被処理汚水を領域間において移動させるものであって、例えば、区画部材の頂部よりも低い位置に領域間を常時連通する連通径路を設けこの連通径路を介して領域間を常時連通する態様や、被処理汚水の水面高さが区画部材の頂部よりも低くなった場合にのみ連通径路、ポンプ、バルブ等を用いて被処理汚水を領域間で移動させる態様等を広く含むものとする。また、このような連通径路の設置形態としては、処理槽内部に設ける場合、処理槽外部に設ける場合、また処理槽の内部および外部に設ける場合等、種々のパターンがある。また、本発明でいう「担体」には、例えば、パーライト、シラスバルーン、発泡コンクリート、活性炭、多孔質セラミック、多孔質硝子等の無機系担体、ポリエチレン、ポリプロピレン、ポリ塩化ビニル、ポリウレタン等の合成樹脂系担体が含まれるものとする。
以上のように、請求項１に記載した汚水の処理装置によれば、被処理汚水の水面が低下した場合でも被処理汚水の循環を極力維持することができる。例えば、流量調整機能付き浄化槽のように、処理過程において水面が変動するような処理槽に特に有効である。
【０００８】
ここで、被処理汚水移動手段は、区画部材に設けられた開孔部である。この開孔部は、被処理汚水は通過するが担体は通過しない開孔を有するものである。これにより、被処理汚水移動手段となる開孔部を区画部材に設けた簡単な構成によって、被処理汚水の水面が低下した場合でも被処理汚水の循環を極力維持することができる。とりわけ、領域間で被処理汚水は循環させるが担体の循環は行わないような処理槽に好適に用いることができる。
【０００９】
また、請求項１に記載の汚水の処理装置において、処理槽内には上部多孔部材と下部多孔部材とが設けられ、両多孔部材の間の空間部には好気性微生物を着床させた担体が充填されている。この空間部は、空間部内において上部多孔部材に設置された隔壁によって好気処理領域と、濾過領域と区画されている。また、処理槽へエアーを供給する散気装置が設けられている。そして、散気装置から処理槽へエアーが供給されると、そのエアー流によって被処理汚水が隔壁の頂部を越えて好気処理領域と濾過領域との間で循環する。更に、隔壁が、被処理汚水および担体が通過しない仕切部と、被処理汚水の通過を許容し且つ担体の通過を阻止する開孔部を有し、仕切部によって、空間部を好気処理領域と濾過領域とに区画する構成である。そして仕切部の下方に連通部が設けられる。また隔壁において該隔壁の頂部よりも下方で且つ上部多孔部材と仕切部の間には、開孔部が設けられている。この開孔部は、被処理汚水は通過するが担体は通過しない開孔を有するものである。これにより、被処理汚水の水面が低下した場合でも好気処理領域と濾過領域との間で被処理汚水が移動し被処理汚水の循環が維持されることとなる。また、好気処理領域と濾過領域との間における担体の円滑な移動が維持されることとなる。また、隔壁に開孔部を設けたため、好気処理領域と濾過領域との間で被処理汚水を移動させる構成が簡単である。しかも、好気処理領域と濾過領域との間における担体の循環は開孔部によって阻止されることとなる。従って、とりわけ、槽内で担体および被処理汚水を流動させて好気性処理（生物処理）および濾過を行う処理槽、すなわち好気処理領域と濾過領域との間で被処理汚水は循環させるが担体の循環は行わないような処理槽に好適に用いることができる。
【００１０】
また、請求項２に記載の汚水の処理装置では、処理槽の上部には、装置上流設備から空間部に被処理汚水を流入させる流入口が設けられ、処理槽の下部には、空間部から被処理汚水を流出させる流出口が設けられる。そして流出口の下流側は、処理槽で処理された処理水を装置下流設備側へ送る抜出径路と、処理水を装置上流設備へ送る循環径路とに分岐されている。この処理装置によれば、処理槽の流出口が抜出径路と循環径路とに連絡されているため、処理槽から抜き出される処理水の一部を装置上流設備側へ循環させることができる。
ここで、このような汚水の処理装置は、図１に示すような担体流動生物濾過槽を、夾雑物除去槽、嫌気濾床槽、処理水槽、消毒槽等の各種の処理槽の全部または一部と組み合わせることによって構成するのが好ましい。このように構成すれば、例えば、担体流動生物濾過槽の流出口と連絡する循環径路によって、担体流動生物濾過槽で処理された被処理汚水の一部を夾雑物除去槽へ循環させ、残りの被処理汚水を抜出径路によって処理水槽へ送ることができる。これにより、例えば、被処理汚水を担体流動生物濾過槽から１パスで抜き出す場合に比して、装置下流設備側へ送る被処理汚水の性状を安定化させることができる。
【００１１】
請求項３に記載の汚水の処理方法では、区画部材の頂部よりも水面が低下した被処理汚水を領域間において移動させる被処理汚水移動手段を設けたうえで、第１の処理行程において所定の手順を順次行うことによって、被処理汚水の水面が低下した場合でも領域間で被処理汚水を移動させ被処理汚水の循環を維持することができる。また、領域間における担体の円滑な移動を維持することができる。
例えば、流量調整機能付き浄化槽のように、処理過程において水面が変動するような汚水の処理に特に有効である。
【００１２】
また、請求項３に記載の汚水の処理方法では、区画部材に被処理汚水は通過するが担体は通過しないような開孔部を設けたうえで、第１の処理行程を行う。この第１の処理行程としては例えば担体流動生物濾過槽における通常運転がある。第１の処理行程（通常運転）において所定の手順を順次行うことによって、被処理汚水の水面が低下した場合でも領域間で被処理汚水を移動させ被処理汚水の循環を維持することができる。とりわけ、領域間で被処理汚水は循環させるが担体の循環は行わないような汚水処理に好適に用いることができる。
【００１３】
また、請求項３に記載の汚水の処理方法では、隔壁に被処理汚水は通過するが担体は通過しないような開孔部を設けたうえで、第１の処理行程において所定の手順を順次行うことによって、被処理汚水の水面が低下した場合でも好気処理領域と濾過領域との間で被処理汚水を移動させ被処理汚水の循環を維持することができる。好気処理領域と濾過領域との間における担体の円滑な移動を維持することができる。とりわけ、槽内で担体および被処理汚水を流動させて好気性処理（生物処理）および濾過を行う処理槽、すなわち好気処理領域と濾過領域との間で被処理汚水は循環させるが担体の循環は行わないような処理槽に好適に用いることができる。
【００１４】
また、請求項４に記載の汚水の処理方法では、第１の処理行程の次に第２の処理行程を行う。この第２の処理行程としては例えば担体流動生物濾過槽における逆洗運転がある。第２の処理行程（逆洗運転）において散気装置から濾過領域へエアーを供給することで、担体に捕捉された被濾過物をエアー流れによって該担体から剥離させることができる。また、この被濾過物は処理槽から抜き出される。すなわち、濾過領域の逆洗が行われることとなる。そしてこの際、隔壁の頂部よりも被処理汚水の水面が低下しても、開孔部及び連通部を介して好気処理領域と濾過領域との間で被処理汚水の循環は維持されることとなる。濾過領域の担体の逆洗過程において被処理汚水の水面は低下していくが、開孔部を設けることで開孔部を設けない場合に比して被処理汚水の循環を維持する時間を延ばすことできる。
従って、請求項４に記載の汚水の処理方法によれば、第２の処理行程において、濾過領域の担体を効率よく逆洗することができる。
【００１５】
【発明の実施の形態】
以下に、本発明の一実施の形態の担体流動生物濾過槽の構成等を図面を用いて説明する。ここで、図１は、汚水の処理行程の概要を示す図である。また、図２は、担体流動生物濾過槽１０の模式図である。また、図３は図２中の開孔部の構成を示す平面図であり、図４は別の実施の形態の開孔部の構成を示す平面図である。
【００１６】
図１に示すように、例えば一般家庭から排出された原汚水は、夾雑物除去槽１、嫌気濾床槽２、担体流動生物濾過槽１０、処理水槽３、消毒槽４等によって構成される汚水の処理装置で順に処理され、浄化水として放流される。
夾雑物除去槽１では、原汚水中に含まれる大きな固形物や油脂等の固液分離を行う。また、嫌気濾床槽２では、夾雑物除去槽１で処理された処理水中の有機性汚濁物質を嫌気性微生物の働きによって嫌気分解する。また、担体流動生物濾過槽１０（本発明における処理槽に対応している）では、酸素が存在する好気性条件下において、嫌気濾床槽２で処理された処理水Ａ中の有機汚濁物質を槽内の好気性微生物によって分解（酸化）する。また、処理水槽３では、担体流動生物濾過槽１０で処理された処理水を一時的に貯留し、必要に応じて夾雑物除去槽１へ循環させる。また、消毒槽４では、放流する前の処理水の消毒を行う。
【００１７】
図２に示すように、担体流動生物濾過槽１０の槽本体１２には、流入口１３および流出口１４が設けられている。流入口１３は、図１中の嫌気濾床槽２から抜き出された処理水Ａを槽本体１２へ受入れるものである。また、流出口１４は、担体流動生物濾過槽１０で処理された処理水Ｂを槽本体１２から抜き出すものである。なお、図２では処理水Ｂの抜き出し構造を模式的に示しているが、処理水Ｂの抜き出し構造は、例えば、槽本体１２の槽壁を越えて処理水Ｂが流出することで槽本体１２内の滞液量および水面高さが一定に保たれる、いわゆる押出し流れの原理を用いたものや、また、槽本体１２内の滞液量および水面高さを槽本体１２への受入れ量と槽本体１２からの抜き出し量とのバランスによって制御するものを用いることができる。このようにして、処理水Ａは担体流動生物濾過槽１０で連続式で処理される。
【００１８】
また、流出口１４の下流側は、循環径路１５と抜出径路１６との２つに分岐されており、槽本体１２から抜き出される処理水Ｂは、循環径路１５、抜出径路１６を介して夾雑物除去槽１、処理水槽３へ送られるように構成されている。例えば、後述する通常運転において、槽本体１２から抜き出される処理水Ｂの一部は循環径路１５を通じて夾雑物除去槽１へ戻され、残りは抜出径路１６を通じて処理水槽３へ送られる。また、後述する逆洗運転において、槽本体１２から抜き出される逆洗水は、循環径路１５を通じて夾雑物除去槽１へ送られる。そして、夾雑物除去槽１への液移送の際に、担体流動生物濾過槽１０の水面が一時的に低下するため、上流側の処理槽から担体流動生物濾過槽１０へ被処理汚水を受入れる箇所に流量調整手段（例えば、間欠定量ポンプ）が設けられている。
なお、夾雑物除去槽１等が本発明における装置上流設備に対応しており、処理水槽３が本発明における装置下流設備に対応している。
【００１９】
次に、槽本体１２の内部の構成について説明する。
槽本体１２には、上部多孔部材１８および下部多孔部材１９によって区画された高さＬ１の担体充填領域２０（本発明における空間部に対応している）が形成されている。この担体充填領域２０には、例えば、中空円筒状に形成された所定量の粒状担体Ｃ（本発明における担体に対応している）が充填されている。この粒状担体Ｃには、酸素が存在する好気性条件下において有機汚濁物質を分解（酸化）する好気性微生物が着床されている。そして、粒状担体Ｃは上部多孔部材１８および下部多孔部材１９によって区画された担体充填領域２０内を移動可能に構成されている。なお、上部多孔部材１８および下部多孔部材１９はいずれも複数の孔を有する多孔板であり、この孔は粒状担体Ｃが通過しない大きさに形成されている。すなわち、多孔部材１８，１９は被処理汚水の通過は許容するが粒状担体Ｃの通過は許容しない。従って、担体充填領域２０外への粒状担体Ｃの流出が多孔部材１８，１９によって阻止されることとなる。
【００２０】
担体充填領域２０内において、上部多孔部材１８にはＬ１よりも低い高さＨの隔壁４０（本発明における区画部材に対応している）が設置されている。また、隔壁４０の下部には、第１担体充填部２１と第２担体充填部２２を連通する連通口１１（本発明における連通部に対応している）が形成されている。隔壁４０は担体充填領域２０を左右に区画するものであり、担体充填領域２０は隔壁４０を介して第１担体充填部２１と第２担体充填部２２とに区画されている。従って、粒状担体Ｃは、隔壁４０によって第１担体充填部２１に属する粒状担体Ｃ１と、第２担体充填部２２に属する粒状担体Ｃ２とに分配される。そして、粒状担体Ｃ１，Ｃ２は連通口１１を介して第１担体充填部２１と第２担体充填部２２との間を移動可能に構成されている。なお、担体充填領域２０への粒状担体Ｃの初期充填時（図２）において、第１担体充填部２１および第２担体充填部２２における充填高さはいずれもＬ２（＜Ｌ１）である。
【００２１】
図２に示すように、隔壁４０は被処理汚水および粒状担体Ｃが通過しない仕切部４１と、被処理汚水は通過するが粒状担体Ｃは通過しない開孔部４２（本発明の被処理汚水移動手段に対応している）とによって構成されている。そして、上部多孔部材１８と仕切部４１との間に開孔部４２が設けられている。この開孔部４２は、図３に示すように、枠体４２ａ内に粒状担体Ｃの粒径よりも小さい複数のスリット４２ｂ（開孔）を有するものである。これにより、被処理汚水の水面が隔壁４０の頂部４０ａよりも低く、仕切部４１よりも高い場合には、被処理汚水はスリット４２ｂを介して第１担体充填部２１と第２担体充填部２２との間で移動することとなる。
なお、隔壁４０に、図３に示す開孔部４２にかえて図４に示すような開孔部４３を設けることもできる。この開孔部４３は、枠体４３ａ内に粒状担体Ｃの粒径よりも小さい複数の格子４３ｂ（開孔）を有するものである。従って、隔壁４０に開孔部４３を設けた場合でも開孔部４２を設けた場合と同様の効果を奏することとなる。
【００２２】
下部多孔部材１９の下方位置には、第１担体充填部２１と第２担体充填部２２の各々に対応した位置に、第１散気装置３１、第２散気装置３２が設置されている。散気装置３１，３２は、ブロワ（図示省略）に接続された散気管３１ａ，３２ａを備え、ブロワを起動させることによって散気管３１ａ，３２ａから第１担体充填部２１，第２担体充填部２２へ所定量のエアー（酸素を含むガス）を供給するように構成されている。また、初期充填時（図２）において、例えば第１散気装置３１を運転した場合には、エアーの上向流が第１担体充填部２１の粒状担体Ｃ１に作用することで、第２担体充填部２２の粒状担体Ｃ２は連通口１１を介して第１担体充填部２１内へ移動するように構成されている。この第１散気装置３１のエアーの上向流によって、更に、担体流動生物濾過槽１０における被処理汚水は、第１担体充填部２１と第２担体充填部２２との間で循環するように構成されている。
なお、担体流動生物濾過槽１０以外の他の処理槽は周知のものであり、他の処理槽の構成等についての詳細な説明は省略する。
【００２３】
次に、上記構成の担体流動生物濾過槽１０における汚水の処理方法について、図５〜図８を参照しながら説明する。ここで、図５は担体流動生物濾過槽１０の模式図であって、通常運転時の状態を示すものである。また、図６は担体流動生物濾過槽１０の模式図であって、逆洗運転時の状態を示すものである。図７は担体流動生物濾過槽１０の部分拡大図であって、隔壁４０の頂部４０ａよりも水面が高い場合の被処理汚水の移動状態を示すものである。また、図８は担体流動生物濾過槽１０の部分拡大図であって、隔壁４０の頂部４０ａよりも水面が低い場合の被処理汚水の移動状態を示すものである。
【００２４】
本実施の形態の汚水の処理方法には、通常運転と逆洗運転とがある。そして通常運転が本発明における第１の処理行程に対応しており、逆洗運転が本発明における第２の処理行程に対応している。通常運転では、処理水Ａ中の有機汚濁物質を、酸素が存在する好気性条件下において好気性微生物によって分解（酸化）する好気性処理（生物処理）と、この分解の際に発生する汚泥等の被濾過物を粒状担体Ｃによって濾過する処理とを行う。また、逆洗運転では、通常運転時に粒状担体Ｃによって濾過され、また粒状担体Ｃから剥離した汚泥等の被濾過物を槽本体１２から除去することで、槽本体１２を洗浄する逆洗処理を行う。なお、本実施の形態の通常運転では、第１担体充填部２１が好気性処理を行う好気処理領域（生物処理領域）を構成し、第２担体充填部２２が濾過を行う濾過領域を構成する。散気装置３１，３２によるエアーの供給先を切り換えることで、第１担体充填部２１を好気処理領域とし、第２担体充填部２２を濾過領域とすることもできる。
以下、通常運転および逆洗運転における処理態様を詳細に説明する。
【００２５】
まず、通常運転では、流入口１３から槽本体１２へ所定量の処理水Ａを供給する。そして、流出口１４から循環径路１５および抜出径路１６を通じてそれぞれ循環水および処理水Ｂが抜き出される。また、槽本体１２から抜き出される処理水の一部は循環径路１５を通じて夾雑物除去槽１へ戻される。このように構成したため、処理水を槽本体１２から１パスで抜き出す場合に比して、抜出径路１６を通じて抜き出される処理水Ｂの性状を安定化させることができる。
【００２６】
そして、この通常運転において第１散気装置３１を運転することで、図５に示すように第１担体充填部２１へ酸素を含むエアーを供給する。これにより、第１担体充填部２１の粒状担体Ｃ１に着床させた好気性微生物に酸素が付与される。これにより、第１担体充填部２１に好気性微生物が好気性処理を行うことができる好気性条件が形成される。また、第１担体充填部２１の下方からエアーを供給することで、第１担体充填部２１の被処理汚水はエアーの上向流を受け、被処理汚水の移動が開始される。そして、第１担体充填部２１と第２担体充填部２２との間で、隔壁４０を中心とした図５中の時計回り（右回り）の旋回流が形成される。すなわち、第１担体充填部２１には被処理汚水の上向流が形成され、第２担体充填部２２には被処理汚水の下向流が形成される。
【００２７】
通常運転において、図７に示すように隔壁４０の頂部４０ａよりも被処理汚水の水面が高い場合（水位線Ｈ.Ｗ.Ｌ.）は、上向流を受けた第１担体充填部２１の被処理汚水は、上部多孔部材１８の上側の径路および開孔部４２を通って２つの系統で第２担体充填部２２へ移動する。また、第２担体充填部２２の被処理汚水は、下部多孔部材１９の下側の径路および連通口１１を通って第１担体充填部２１へ移動する。これにより、第１担体充填部２１と第２担体充填部２２との間で被処理汚水が循環する流れ、いわゆる旋回流が形成される。
【００２８】
一方、図８に示すように隔壁４０の頂部４０ａよりも被処理汚水の水面が低い場合（水位線Ｌ.Ｗ.Ｌ.）は、上向流を受けた第１担体充填部２１の被処理汚水は、開孔部４２を通って第２担体充填部２２へ移動する。また、第２担体充填部２２の被処理汚水は、下部多孔部材１９の下側の径路および連通口１１を通って第１担体充填部２１へ移動する。これにより、第１担体充填部２１と第２担体充填部２２との間で旋回流が形成される。従って、隔壁４０の頂部４０ａよりも被処理汚水の水面が低い場合であっても、仕切部４１の上側に水面があれば、第１担体充填部２１と第２担体充填部２２との間での旋回流は維持されることとなる。
【００２９】
従って、通常運転時に夾雑物除去槽１へ循環水を移送する際、担体流動生物濾過槽１０の水面が低下するが、隔壁４０に開孔部４２を設けたことによって、被処理汚水の旋回流を維持することができる。また、被処理汚水の旋回流を維持することで、第１担体充填部２１と第２担体充填部２２との間における粒状担体の円滑な移動が維持されることとなる。
【００３０】
また、被処理汚水の旋回流に伴って第１担体充填部２１の粒状担体Ｃ１は上向流を受け、第２担体充填部２２の粒状担体Ｃ２は下向流を受ける。これにより、第２担体充填部２２の粒状担体Ｃ２は、隔壁４０の下方に形成された連通口１１を介して第１担体充填部２１内へ移動し、図５に示すように、第１担体充填部２１に高さＬ１まで粒状担体が充填された状態へと移行する。これにより、第１担体充填部２１側の粒状担体Ｃ１の量が初期充填時よりも増加する。
【００３１】
このような通常運転では、第１担体充填部２１の粒状担体Ｃ１に着床させた好気性微生物によって処理水Ａ中の有機汚濁物質が好気性処理され、第１担体充填部２１において汚泥等が発生する。そして、この汚泥等は、被処理汚水の上向流によって第２担体充填部２２へ流れ込み、第２担体充填部２２の上部の空間に徐々に堆積していく。而して、粒状担体Ｃ２の濾過作用によって第２担体充填部２２に堆積層Ｓが形成される。
【００３２】
通常運転が終了すると、次に逆洗運転を行う。この逆洗運転では、第２散気装置３２を運転することで、図６に示すように第２担体充填部２２へエアーを供給する。これにより、第２担体充填部２２の被処理汚水はエアーの上向流を受け、被処理汚水の移動が開始される。そして、第１担体充填部２１と第２担体充填部２２との間で、隔壁４０を中心とした図６中の反時計回り（左回り）の旋回流が形成される。すなわち、第１担体充填部２１には被処理汚水の下向流が形成され、第２担体充填部２２には被処理汚水の上向流が形成される。
【００３３】
また、この際第１担体充填部２１の粒状担体Ｃ１は、隔壁４０の下方に形成された連通口１１を介して第２担体充填部２２内へ移動しながら第２担体充填部２２内で流動化する。そして、第１担体充填部２１の粒状担体Ｃ１は、図６に示すように第２担体充填部２２内に粒状担体がほぼ満たされた状態になるまで第２担体充填部２２側へ移動する。この逆洗運転の間、第２担体充填部２２における粒状担体の流動化によって、粒状担体に捕捉された汚泥等が剥離し、堆積層Ｓやその他の汚泥等を含む逆洗水は、槽本体１２から循環径路１５を通じて夾雑物除去槽１へ抜き出される。
【００３４】
この逆洗運転において、図７に示すように、隔壁４０の頂部４０ａよりも被処理汚水の水面が高い場合（水位線Ｈ.Ｗ.Ｌ.）は、通常運転時と同様に、第１担体充填部２１と第２担体充填部２２との間で被処理汚水の旋回流が形成される。一方、図８に示すように、隔壁４０の頂部４０ａよりも被処理汚水の水面が低い場合（水位線Ｌ.Ｗ.Ｌ.）は、通常運転時と同様に、開孔部４２によって第１担体充填部２１と第２担体充填部２２との間で被処理汚水の旋回流が維持される。
逆洗運転では、夾雑物除去槽１へ逆洗水を移送するにつれて担体流動生物濾過槽１０の水面が低下していく。そして、被処理汚水の水面が仕切部４１よりも低くなるまで旋回流が維持され、被処理汚水の水面が仕切部４１よりも低くなると逆洗が終了する。従って、開孔部４２を設けない場合に比して旋回流が維持される時間を延ばすことができ、逆洗時間を延ばすことで粒状担体を効率よく逆洗することができる。
なお、この逆洗運転では、通常運転時よりも多量のエアーが供給されることが好ましい。これにより、粒状担体をより激しく流動させることができ、粒状担体に捕捉された汚泥等をより剥離させ易い。
逆洗運転が終了すると、必要に応じて再度通常運転を再開する。
【００３５】
以上のように構成した担体流動生物濾過槽１０および該担体流動生物濾過槽１０を用いた処理方法によれば、通常運転時に被処理汚水の水面が隔壁４０の頂部４０ａより低下した場合でも、開孔部４２を介して第１担体充填部２１（好気処理領域）と第２担体充填部２２（濾過領域）との間で被処理汚水の循環を維持することができる。これにより、また、第１担体充填部２１（好気処理領域）と第２担体充填部２２（濾過領域）との間における粒状担体の円滑な移動が維持されることとなる。また、隔壁４０に開孔部４２を設けたため、第１担体充填部２１（好気処理領域）と第２担体充填部２２（濾過領域）との間で被処理汚水を移動させる構成が簡単である。
また、逆洗運転時では、開孔部を設けない場合に比して被処理汚水の循環を維持する時間を延ばし、第２担体充填部２２（濾過領域）の担体を効率よく逆洗することができる。
【００３６】
なお、本発明は上記の実施の形態のみに限定されるものではなく、種々の応用や変形が考えられる。
【００３７】
上記実施の形態では、隔壁４０に開孔部４２を設ける場合について記載したが、同様の開孔部もしくは同様の機能を有する部材を隔壁４０以外に設けることもできる。例えば、担体流動生物濾過槽１０の外部に第１担体充填部２１（好気処理領域）と第２担体充填部２２（濾過領域）を連通する径路を設け、この径路内にスリット４２ｂや格子４３ｂを配置することもできる。
【００３８】
また、上記実施の形態では、散気装置によって第１担体充填部２１（好気処理領域）へエアーを供給することで、第１担体充填部２１（好気処理領域）と第２担体充填部２２（濾過領域）との間で被処理汚水が循環される場合について記載したが、被処理汚水を循環させる手段はこれに限定されず必要に応じて種々変更可能である。例えば、槽本体１２に循環ラインを設け、ポンプ等によって槽本体１２内の被処理汚水を循環するように構成することもできる。
【００３９】
また、上記実施の形態では、担体流動生物濾過槽１０内の被処理水の水面が隔壁４０の頂部４０ａよりも上側にある場合でも被処理水が開孔部４２を通過する場合について記載したが、被処理水の水面が隔壁４０の頂部４０ａより低下した場合にのみ、第１担体充填部２１（好気処理領域）と第２担体充填部２２（濾過領域）を連通するように構成することもできる。
【００４０】
【発明の効果】
以上説明したように、本発明によれば、微生物を着床させた担体が充填された処理槽を有する汚水の処理装置において、被処理汚水の水面が変動した場合でも被処理汚水の循環を極力維持することで好適な処理を行う合理的な汚水処理技術を実現することができる。
【図面の簡単な説明】
【図１】汚水の処理行程の概要を示す図である。
【図２】担体流動生物濾過槽１０の模式図である。
【図３】図２中の開孔部の構成を示す平面図である。
【図４】別の実施の形態の開孔部の構成を示す平面図である。
【図５】担体流動生物濾過槽１０の模式図であって、通常運転時の状態を示すものである。
【図６】担体流動生物濾過槽１０の模式図であって、逆洗運転時の状態を示すものである。
【図７】担体流動生物濾過槽１０の部分拡大図であって、隔壁４０の頂部４０ａよりも水面が高い場合の被処理汚水の移動状態を示すものである。
【図８】担体流動生物濾過槽１０の部分拡大図であって、隔壁４０の頂部４０ａよりも水面が低い場合の被処理汚水の移動状態を示すものである。
【符号の説明】
１０…担体流動生物濾過槽（処理槽）
１１…連通口（連通部）
１２…槽本体
１８…上部多孔部材
１９…下部多孔部材
２０…担体充填領域
２１…第１担体充填部
２２…第２担体充填部
３１…第１散気装置
３２…第２散気装置
４０…隔壁（区画部材）
４０ａ…頂部
４１…仕切部
４２，４３…開孔部
４２ａ，４３ａ…枠体
４２ｂ…スリット
４３ｂ…格子
Ｃ，Ｃ１，Ｃ２…粒状担体
Ｓ…堆積層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to sewage treatment using a carrier, and more particularly to a sewage treatment technique using a carrier on which a microorganism for biologically treating sewage is deposited.
[0002]
[Prior art]
Conventionally, for example, a sewage treatment tank that purifies raw sewage discharged from a general household is known. In such a conventional sewage treatment tank, a certain amount of carrier in which, for example, aerobic microorganisms are implanted is filled in a carrier filling region surrounded by an upper porous plate and a lower porous plate. In addition, the carrier filling region is divided into a biological treatment region (aerobic treatment region) and a filtration region, and a partition that enables the carrier to move between the two regions via the communicating portion, and air (oxygen from the bottom in the tank) ) Is provided. And by supplying air into a tank with a diffuser, sewage circulates around a partition, and flows between a biological treatment area | region and a filtration area | region. During this sewage circulation, the carrier is prevented from flowing out of the carrier filling region by the upper perforated plate.
[0003]
In the sewage treatment tank having such a configuration, so-called biological treatment is performed in which the organic contaminants in the sewage are decomposed (oxidized or reduced) by microorganisms by flowing the carrier together with the sewage in the biological treatment region. Moreover, the filtration process which filters the to-be-filtered material etc. which generate | occur | produce by biological treatment with a support | carrier is performed. Further, the backwash process is performed in which sludge and the like captured by the carrier by the filtration process are physically separated by an air flow, and the backwash water containing the sludge and the like is extracted from the wastewater treatment tank.
[0004]
[Problems to be solved by the invention]
In the above-described conventional sewage treatment tank, when the sewage water level is higher than the top of the partition wall, for example, the sewage in the biological treatment area moves over the partition wall to the filtration area, and the sewage in the filtration area passes through the communication part. The sewage in the tank circulates by moving to the treatment area.
However, when the surface of the sewage is lower than the top of the partition wall, the sewage circulation is not established between the biological treatment area and the filtration area. When the sewage is not circulated during the biological treatment, there is a problem in that the smooth movement of the carrier between the biological treatment region and the filtration region is prevented and suitable treatment is hindered. Further, there is a problem that the backwashing itself cannot be performed if the sewage is not circulated during the backwashing process. And the problem by such a water level fall is remarkable especially in the processing tank where a water surface fluctuates in a process like a septic tank with a flow control function.
[0005]
If the top of the partition and the upper porous member are made below the low water level line (L.W.L.) so that the circulation is performed even if the water level is lowered, the capacity of the region that can be filled with the carrier is reduced, and the processing efficiency is reduced. Becomes worse. Therefore, the present invention is suitable for a sewage treatment apparatus having a treatment tank filled with a carrier on which microorganisms are implanted, by maintaining the circulation of treated sewage as much as possible even when the surface of the treated sewage fluctuates. It is an object to provide a rational sewage treatment technology for treatment.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, wastewater treatment apparatus of the present invention is constructed as described in claim 1及beauty 2. Moreover, the wastewater treatment method of the present invention is as described in claims 3 and 4 .
[0007]
The sewage treatment apparatus according to claim 1, wherein the treatment tank is filled with a carrier on which microorganisms are deposited. These microorganisms include aerobic microorganisms that aerobically decompose organic pollutants in wastewater and anaerobic microorganisms that anaerobically decompose. Further, a plurality of regions and partition members (partition walls) for partitioning these regions are provided in the treatment tank. Further, an air diffuser for supplying air to the treatment tank is provided. And if air is supplied to a processing tank from a diffuser, the to-be-processed sewage will circulate between area | regions over a partition member with the air flow. Furthermore, the to-be-processed sewage moving means (opening part) which moves the to-be-processed sewage whose water surface fell rather than the top part of the division member between area | regions is provided. Here, the “top portion” as used in the present invention refers to a portion having the highest height in the partition member that partitions the region. Thereby, even when the surface of treated sewage falls, the treated sewage moves between the regions, and the circulation of the treated sewage is maintained. In addition, the smooth movement of the carrier between the regions is maintained.
The “treated sewage moving means” as used in the present invention is to move treated sewage whose water surface is lower than the top of the partition member between the regions, for example, at a position lower than the top of the partition member. A mode in which a communication path that always communicates between the areas is provided, and an area that always communicates between the areas through this communication path, or only when the water surface height of the treated wastewater is lower than the top of the partition member, the pump, A mode of moving the wastewater to be treated between regions using a valve or the like is widely included. In addition, there are various patterns for installing such a communication path, such as when it is provided inside the processing tank, when it is provided outside the processing tank, or when it is provided inside and outside the processing tank. Examples of the “carrier” in the present invention include inorganic carriers such as pearlite, shirasu balloon, foamed concrete, activated carbon, porous ceramic, and porous glass, and synthetic resins such as polyethylene, polypropylene, polyvinyl chloride, and polyurethane. System carriers shall be included.
As described above, according to the sewage treatment apparatus described in claim 1, the circulation of the treated sewage can be maintained as much as possible even when the surface of the treated sewage is lowered. For example, it is particularly effective for a treatment tank in which the water surface fluctuates during the treatment process, such as a septic tank with a flow rate adjusting function.
[0008]
Here, the treated sewage moving means, Ru opening der provided wards image member. The opening has an opening through which the treated sewage passes but the carrier does not pass. Thereby, by the simple structure which provided the opening part used as a to-be-processed sewage transfer means in a partition member, even when the water surface of to-be-processed sewage falls, the circulation of to-be-processed sewage can be maintained as much as possible. In particular, it can be suitably used in a treatment tank in which treated sewage is circulated between regions but the carrier is not circulated.
[0009]
The sewage treatment apparatus according to claim 1 , wherein an upper porous member and a lower porous member are provided in the treatment tank, and an aerobic microorganism is implanted in a space between the porous members. Is filled. This space part is divided into an aerobic treatment region and a filtration region by a partition installed in the upper porous member in the space part . Further, an air diffuser for supplying air to the treatment tank is provided. And if air is supplied to a processing tank from an air diffuser, the to-be-processed wastewater will circulate between an aerobic processing area | region and a filtration area | region over the top part of a partition by the air flow. Further, the partition wall has a partition part through which the treated sewage and the carrier do not pass, and an opening part that allows the treated sewage to pass through and prevents the carrier from passing through, and the partition part makes the space part an aerobic treatment region. And a filtration region. A communication portion is provided below the partition portion. In the partition, an opening is provided below the top of the partition and between the upper porous member and the partition . The opening has an opening through which the treated sewage passes but the carrier does not pass. Thereby, even when the surface of the treated sewage is lowered, the treated sewage moves between the aerobic treatment region and the filtration region, and the circulation of the treated sewage is maintained. In addition, the smooth movement of the carrier between the aerobic treatment region and the filtration region is maintained. Moreover, since the opening part was provided in the partition, the structure which moves a to-be-processed sewage between an aerobic treatment area | region and a filtration area | region is simple. In addition, the circulation of the carrier between the aerobic treatment region and the filtration region is prevented by the opening portion. Therefore, in particular, the carrier and the wastewater to be treated are flowed in the tank to perform the aerobic treatment (biological treatment) and filtration, that is, the wastewater to be treated is circulated between the aerobic treatment region and the filtration region. It can be suitably used for a processing tank in which no circulation is performed.
[0010]
In the sewage treatment apparatus according to claim 2 , an inflow port through which the sewage to be treated flows into the space part from the apparatus upstream equipment is provided in the upper part of the treatment tank, and the lower part of the treatment tank is provided from the space part. An outlet for discharging the sewage to be treated is provided. The downstream side of the outlet is branched into an extraction path for sending treated water treated in the treatment tank to the equipment downstream equipment side, and a circulation path for sending treated water to the equipment upstream equipment. According to this processing apparatus , since the outflow port of the processing tank is connected to the extraction path and the circulation path, a part of the processing water extracted from the processing tank can be circulated to the apparatus upstream equipment side.
Here, such a sewage treatment apparatus includes a carrier flow biological filtration tank as shown in FIG. 1, all or one of various treatment tanks such as a contaminant removal tank, an anaerobic filter bed tank, a treatment water tank, and a disinfection tank. It is preferable to configure by combining with a part. With this configuration, for example, a part of the treated sewage treated in the carrier fluid biological filtration tank is circulated to the contaminant removal tank by a circulation path communicating with the outlet of the carrier fluid biological filtration tank, and the remaining The treated sewage can be sent to the treated water tank through the extraction path. Thereby, compared with the case where the to-be-processed sewage is extracted from a support | carrier flow biological filtration tank by 1 pass, the property of the to-be-processed sewage sent to an apparatus downstream installation side can be stabilized, for example.
[0011]
In the sewage treatment method according to claim 3 , a sewage moving means for moving sewage whose water surface is lower than the top of the partition member is moved between the regions, and then a predetermined amount is given in the first treatment process. By sequentially performing the procedure, the treated sewage can be moved between the regions and the circulation of the treated sewage can be maintained even when the surface of the treated sewage is lowered. In addition, the smooth movement of the carrier between the regions can be maintained.
For example, it is particularly effective for the treatment of sewage whose water surface fluctuates during the treatment process, such as a septic tank with a flow rate adjusting function.
[0012]
In the sewage treatment method according to the third aspect , the first treatment process is performed after the partition member is provided with an opening portion through which the treated sewage passes but the carrier does not pass. As this first treatment process, for example, there is a normal operation in a carrier flow biological filtration tank. By sequentially performing a predetermined procedure in the first treatment process (normal operation), it is possible to move the treated wastewater between the regions and maintain the circulation of the treated wastewater even when the water level of the treated wastewater is lowered. In particular, it can be suitably used for sewage treatment in which sewage to be treated is circulated between regions but the carrier is not circulated.
[0013]
In the sewage treatment method according to claim 3 , a predetermined procedure is sequentially performed in the first treatment step after providing an opening in the partition wall so that the treated sewage passes but the carrier does not pass. Thus, even when the water level of the wastewater to be treated is lowered, the wastewater to be treated can be moved between the aerobic treatment region and the filtration region to maintain the circulation of the wastewater to be treated. Smooth movement of the carrier between the aerobic treatment region and the filtration region can be maintained. In particular, a treatment tank that performs aerobic treatment (biological treatment) and filtration by flowing the carrier and treated wastewater in the tank, that is, the treated wastewater is circulated between the aerobic treatment area and the filtration area, but the carrier is circulated. Can be suitably used for a treatment tank that does not carry out the treatment.
[0014]
In the sewage treatment method according to claim 4 , the second treatment process is performed after the first treatment process. As this second treatment process, for example, there is a backwash operation in a carrier fluidized biological filtration tank. By supplying air from the diffuser to the filtration region in the second treatment step (back washing operation), the object to be filtered captured by the carrier can be separated from the carrier by the air flow. Moreover, this to-be-filtered object is extracted from a processing tank. That is, backwashing of the filtration region is performed. At this time, even if the surface of the treated sewage is lower than the top of the partition wall, the circulation of the treated sewage is maintained between the aerobic treatment region and the filtration region via the opening and the communication portion. It becomes. In the backwash process of the carrier in the filtration region, the surface of the sewage to be treated is lowered, but by providing the opening part, the time for maintaining the circulation of the sewage to be treated is extended as compared with the case of not providing the opening part. I can.
Therefore, according to the method for treating sewage according to claim 4 , the carrier in the filtration region can be backwashed efficiently in the second treatment step.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Below, the structure of the carrier fluid biological filtration tank of one embodiment of this invention is demonstrated using drawing. Here, FIG. 1 is a diagram showing an outline of the treatment process of sewage. FIG. 2 is a schematic diagram of the carrier fluid biological filtration tank 10. 3 is a plan view showing the configuration of the aperture portion in FIG. 2, and FIG. 4 is a plan view showing the configuration of the aperture portion of another embodiment.
[0016]
As shown in FIG. 1, for example, raw sewage discharged from a general household is sewage constituted by a contaminant removal tank 1, an anaerobic filter bed tank 2, a carrier fluid biological filtration tank 10, a treatment water tank 3, a disinfection tank 4, and the like. Are sequentially processed by the treatment apparatus and discharged as purified water.
In the contaminant removal tank 1, solid-liquid separation of large solids and oils and fats contained in the raw sewage is performed. Moreover, in the anaerobic filter bed tank 2, the organic pollutant in the treated water treated in the contaminant removal tank 1 is anaerobically decomposed by the action of anaerobic microorganisms. In addition, in the carrier fluid biological filtration tank 10 (corresponding to the treatment tank in the present invention), organic pollutants in the treated water A treated in the anaerobic filter bed tank 2 under aerobic conditions in which oxygen is present. Degraded (oxidized) by aerobic microorganisms in the tank. In the treated water tank 3, treated water treated in the carrier fluid biological filtration tank 10 is temporarily stored and circulated to the contaminant removing tank 1 as necessary. In the sterilization tank 4, the treated water before being discharged is sterilized.
[0017]
As shown in FIG. 2, the tank body 12 of the carrier flow biological filtration tank 10 is provided with an inlet 13 and an outlet 14. The inflow port 13 receives the treated water A extracted from the anaerobic filter bed tank 2 in FIG. Moreover, the outflow port 14 extracts the treated water B treated in the carrier fluid biological filtration tank 10 from the tank body 12. In addition, in FIG. 2, the extraction structure of the treated water B is schematically shown. However, the extracted structure of the treated water B is, for example, the tank body 12 when the treated water B flows out over the tank wall of the tank body 12. The amount of stagnant liquid in the tank and the water surface height are kept constant, using the principle of so-called extrusion flow, and the amount of liquid stagnated in the tank body 12 and the water surface height are What controls according to the balance with the extraction amount from the tank main body 12 can be used. In this way, the treated water A is treated continuously in the carrier fluid biological filtration tank 10.
[0018]
Further, the downstream side of the outlet 14 is branched into a circulation path 15 and an extraction path 16, and the treated water B extracted from the tank body 12 passes through the circulation path 15 and the extraction path 16. It is configured to be sent to the contaminant removal tank 1 and the treated water tank 3. For example, in the normal operation described later, a part of the treated water B extracted from the tank body 12 is returned to the contaminant removal tank 1 through the circulation path 15 and the rest is sent to the treated water tank 3 through the extraction path 16. Further, in the backwash operation described later, the backwash water extracted from the tank body 12 is sent to the contaminant removal tank 1 through the circulation path 15. And, since the water surface of the carrier fluid biological filtration tank 10 is temporarily lowered during the liquid transfer to the contaminant removal tank 1, the treated wastewater is received from the upstream treatment tank into the carrier fluid biological filtration tank 10. Is provided with a flow rate adjusting means (for example, an intermittent metering pump).
In addition, the contaminant removal tank 1 etc. respond | corresponds to the apparatus upstream installation in this invention, and the treated water tank 3 respond | corresponds to the apparatus downstream installation in this invention.
[0019]
Next, the internal configuration of the tank body 12 will be described.
The tank body 12 is formed with a carrier filling region 20 (corresponding to a space portion in the present invention) having a height L1 defined by the upper porous member 18 and the lower porous member 19. The carrier filling region 20 is filled with, for example, a predetermined amount of granular carrier C (corresponding to the carrier in the present invention) formed in a hollow cylindrical shape. The granular carrier C is implanted with aerobic microorganisms that decompose (oxidize) organic pollutants under aerobic conditions where oxygen is present. The granular carrier C is configured to be movable in the carrier filling region 20 defined by the upper porous member 18 and the lower porous member 19. Each of the upper porous member 18 and the lower porous member 19 is a porous plate having a plurality of holes, and the holes are formed in such a size that the granular carrier C does not pass through. That is, the porous members 18 and 19 allow the treated wastewater to pass but do not allow the granular carrier C to pass. Therefore, the porous members 18 and 19 prevent the granular carrier C from flowing out of the carrier filling region 20.
[0020]
In the carrier filling region 20, the upper porous member 18 is provided with a partition wall 40 having a height H lower than L1 (corresponding to the partition member in the present invention). In addition, a communication port 11 (corresponding to the communication portion in the present invention) that connects the first carrier filling portion 21 and the second carrier filling portion 22 is formed in the lower portion of the partition wall 40. The partition wall 40 divides the carrier filling region 20 on the left and right sides. The carrier filling region 20 is partitioned into a first carrier filling part 21 and a second carrier filling part 22 via the partition wall 40. Accordingly, the granular carrier C is distributed by the partition wall 40 into the granular carrier C1 belonging to the first carrier filling part 21 and the granular carrier C2 belonging to the second carrier filling part 22. The granular carriers C1 and C2 are configured to be movable between the first carrier filling portion 21 and the second carrier filling portion 22 via the communication port 11. In the initial filling of the granular carrier C into the carrier filling region 20 (FIG. 2), the filling heights in the first carrier filling portion 21 and the second carrier filling portion 22 are both L2 (<L1).
[0021]
As shown in FIG. 2, the partition 40 has a partition 41 through which the treated sewage and the granular carrier C do not pass, and an opening 42 through which the treated sewage passes but does not pass the granular carrier C (the treated sewage transfer of the present invention). Corresponding to the means). An opening 42 is provided between the upper porous member 18 and the partition 41. As shown in FIG. 3, the opening 42 has a plurality of slits 42 b (openings) smaller than the particle size of the granular carrier C in the frame body 42 a. Thereby, when the surface of the wastewater to be treated is lower than the top portion 40a of the partition wall 40 and higher than the partitioning portion 41, the wastewater to be treated has the first carrier filling portion 21 and the second carrier filling portion 22 via the slit 42b. Will move between.
The partition wall 40 may be provided with an opening 43 as shown in FIG. 4 in place of the opening 42 shown in FIG. The opening 43 has a plurality of lattices 43b (openings) smaller than the particle size of the granular carrier C in the frame 43a. Therefore, even when the opening portion 43 is provided in the partition wall 40, the same effect as that in the case where the opening portion 42 is provided can be obtained.
[0022]
Below the lower porous member 19, a first air diffuser 31 and a second air diffuser 32 are installed at positions corresponding to the first carrier filler 21 and the second carrier filler 22. The air diffusers 31 and 32 include air diffusers 31a and 32a connected to a blower (not shown). When the blower is activated, the first carrier filler 21 and the second carrier filler 22 from the diffusers 31a and 32a. Is configured to supply a predetermined amount of air (a gas containing oxygen). Further, at the time of initial filling (FIG. 2), for example, when the first air diffuser 31 is operated, the upward flow of the air acts on the granular carrier C1 of the first carrier filling portion 21, so that the second carrier The granular carrier C <b> 2 of the filling part 22 is configured to move into the first carrier filling part 21 through the communication port 11. Due to the upward flow of the air in the first air diffuser 31, the treated sewage in the carrier fluid biological filtration tank 10 is further circulated between the first carrier filling part 21 and the second carrier filling part 22. It is configured.
In addition, other processing tanks other than the carrier fluid biological filtration tank 10 are well-known, and detailed description about the structure of another processing tank etc. is abbreviate | omitted.
[0023]
Next, a method for treating sewage in the carrier fluid biological filtration tank 10 having the above configuration will be described with reference to FIGS. Here, FIG. 5 is a schematic view of the carrier fluid biological filtration tank 10 and shows a state during normal operation. FIG. 6 is a schematic diagram of the carrier fluid biological filtration tank 10 and shows a state during the backwash operation. FIG. 7 is a partially enlarged view of the carrier fluid biological filtration tank 10, and shows the state of movement of the sewage to be treated when the water surface is higher than the top 40 a of the partition wall 40. FIG. 8 is a partially enlarged view of the carrier fluid biological filtration tank 10 and shows the state of movement of the sewage to be treated when the water surface is lower than the top 40a of the partition wall 40.
[0024]
The wastewater treatment method of the present embodiment includes a normal operation and a backwash operation. The normal operation corresponds to the first processing step in the present invention, and the backwash operation corresponds to the second processing step in the present invention. In normal operation, organic pollutants in the treated water A are decomposed (oxidized) by aerobic microorganisms under aerobic conditions where oxygen is present, and sludge generated during this decomposition The filtration object is filtered through the granular carrier C. Further, in the backwashing operation, a backwashing process for washing the tank body 12 is performed by removing, from the tank body 12, an object to be filtered such as sludge that has been filtered by the granular carrier C during normal operation and separated from the granular carrier C. Do. In the normal operation of the present embodiment, the first carrier filling unit 21 constitutes an aerobic treatment region (biological treatment region) in which aerobic treatment is performed, and the second carrier filling unit 22 constitutes a filtration region in which filtration is performed. To do. By switching the air supply destinations of the air diffusers 31 and 32, the first carrier filling unit 21 can be used as an aerobic treatment region and the second carrier filling unit 22 can be used as a filtration region.
Hereinafter, processing modes in the normal operation and the backwash operation will be described in detail.
[0025]
First, in normal operation, a predetermined amount of treated water A is supplied from the inlet 13 to the tank body 12. Then, the circulating water and the treated water B are extracted from the outlet 14 through the circulation path 15 and the extraction path 16, respectively. Further, part of the treated water extracted from the tank body 12 is returned to the contaminant removal tank 1 through the circulation path 15. Since it comprised in this way, compared with the case where process water is extracted from the tank main body 12 by 1 path | pass, the property of the process water B extracted through the extraction path 16 can be stabilized.
[0026]
And by operating the 1st air diffuser 31 in this normal driving | operation, the air containing oxygen is supplied to the 1st support | carrier filling part 21, as shown in FIG. As a result, oxygen is imparted to the aerobic microorganisms that have been deposited on the granular carrier C1 of the first carrier filling portion 21. Thereby, the aerobic condition in which the aerobic microorganism can perform the aerobic treatment is formed in the first carrier filling part 21. In addition, by supplying air from below the first carrier filling unit 21, the wastewater to be treated in the first carrier filling unit 21 receives an upward flow of air, and the movement of the wastewater to be treated is started. Then, a clockwise (clockwise) swirling flow in FIG. 5 centering on the partition 40 is formed between the first carrier filling portion 21 and the second carrier filling portion 22. That is, an upward flow of the treated sewage is formed in the first carrier filling part 21, and a downward flow of the treated sewage is formed in the second carrier filling part 22.
[0027]
In normal operation, as shown in FIG. 7, when the surface of the sewage to be treated is higher than the top 40a of the partition wall 40 (water level line H.W.L.), the first carrier filling unit 21 that has received an upward flow. The treated sewage moves to the second carrier filling unit 22 in two systems through the upper path of the upper porous member 18 and the opening 42. The treated sewage in the second carrier filling part 22 moves to the first carrier filling part 21 through the lower path of the lower porous member 19 and the communication port 11. Thereby, the flow through which the wastewater to be treated circulates between the first carrier filling part 21 and the second carrier filling part 22, a so-called swirl flow is formed.
[0028]
On the other hand, as shown in FIG. 8, when the surface of the wastewater to be treated is lower than the top portion 40a of the partition wall 40 (water level line LWL), the first carrier filling portion 21 that has received the upward flow is treated. The sewage moves to the second carrier filling unit 22 through the opening 42. The treated sewage in the second carrier filling part 22 moves to the first carrier filling part 21 through the lower path of the lower porous member 19 and the communication port 11. Thereby, a swirl flow is formed between the first carrier filling part 21 and the second carrier filling part 22. Therefore, even if the surface of the sewage to be treated is lower than the top 40a of the partition wall 40, if there is a water surface on the upper side of the partition 41, the space between the first carrier filling portion 21 and the second carrier filling portion 22 will be described. The swirling flow is maintained.
[0029]
Therefore, when the circulating water is transferred to the contaminant removal tank 1 during normal operation, the water surface of the carrier fluid biological filtration tank 10 is lowered. Can be maintained. Moreover, the smooth movement of the granular carrier between the first carrier filling portion 21 and the second carrier filling portion 22 is maintained by maintaining the swirling flow of the treated wastewater.
[0030]
Further, the granular carrier C1 of the first carrier filling unit 21 receives an upward flow and the granular carrier C2 of the second carrier filling unit 22 receives a downward flow along with the swirling flow of the sewage to be treated. Thereby, the granular carrier C2 of the second carrier filling part 22 moves into the first carrier filling part 21 through the communication port 11 formed below the partition wall 40, and as shown in FIG. It shifts to a state in which the granular carrier is filled up to the height L1 in the filling portion 21. Thereby, the quantity of the granular support | carrier C1 by the side of the 1st support | carrier filling part 21 increases from the time of initial filling.
[0031]
In such a normal operation, the organic pollutant in the treated water A is aerobically treated by the aerobic microorganisms that are deposited on the granular carrier C1 of the first carrier filling unit 21, and sludge and the like are removed in the first carrier filling unit 21. appear. The sludge and the like flow into the second carrier filling unit 22 by the upward flow of the sewage to be treated, and gradually accumulate in the space above the second carrier filling unit 22. Thus, the deposition layer S is formed in the second carrier filling portion 22 by the filtering action of the granular carrier C2.
[0032]
When the normal operation ends, the backwash operation is performed next. In this backwash operation, air is supplied to the second carrier filling section 22 by operating the second air diffuser 32 as shown in FIG. Thereby, the to-be-processed wastewater of the 2nd support | carrier filling part 22 receives the upward flow of air, and the movement of to-be-processed wastewater is started. Then, a counterclockwise (counterclockwise) swirl flow in FIG. 6 centering on the partition wall 40 is formed between the first carrier filling portion 21 and the second carrier filling portion 22. That is, a downflow of the treated sewage is formed in the first carrier filling unit 21, and an upward flow of the treated sewage is formed in the second carrier filling unit 22.
[0033]
At this time, the granular carrier C1 of the first carrier filling portion 21 flows in the second carrier filling portion 22 while moving into the second carrier filling portion 22 through the communication port 11 formed below the partition wall 40. Turn into. Then, the granular carrier C1 of the first carrier filling unit 21 moves toward the second carrier filling unit 22 until the granular carrier is almost filled in the second carrier filling unit 22 as shown in FIG. During this backwashing operation, the sludge trapped on the granular carrier is separated by fluidization of the granular carrier in the second carrier filling unit 22, and the backwash water containing the deposited layer S and other sludge is stored in the tank body. 12 is extracted to the contaminant removal tank 1 through the circulation path 15.
[0034]
In this backwash operation, as shown in FIG. 7, when the surface of the sewage to be treated is higher than the top 40a of the partition wall 40 (water level line H.W.L.), as in the normal operation, the first carrier A swirling flow of the wastewater to be treated is formed between the filling part 21 and the second carrier filling part 22. On the other hand, as shown in FIG. 8, when the surface of the treated sewage is lower than the top 40a of the partition wall 40 (water level line L.W.L.), the first portion is opened by the opening 42 as in the normal operation. A swirling flow of the wastewater to be treated is maintained between the carrier filling unit 21 and the second carrier filling unit 22.
In the backwash operation, as the backwash water is transferred to the contaminant removal tank 1, the water surface of the carrier fluid biological filtration tank 10 decreases. Then, the swirl flow is maintained until the water surface of the treated sewage becomes lower than the partition portion 41, and the backwashing ends when the water surface of the treated sewage becomes lower than the partition portion 41. Therefore, it is possible to extend the time during which the swirl flow is maintained as compared with the case where the opening 42 is not provided, and it is possible to backwash the granular carrier efficiently by extending the backwash time.
In this backwash operation, it is preferable that a larger amount of air is supplied than during normal operation. Thereby, a granular support | carrier can be made to flow more intensely and it is easy to peel sludge etc. which were capture | acquired by the granular support | carrier.
When the backwash operation is completed, normal operation is resumed again as necessary.
[0035]
According to the carrier fluid biological filtration tank 10 configured as described above and the treatment method using the carrier fluid biological filtration tank 10, even when the water level of the sewage to be treated is lower than the top 40a of the partition wall 40 during normal operation, the carrier fluid biological filtration tank 10 is opened. Circulation of the wastewater to be treated can be maintained between the first carrier filling portion 21 (aerobic treatment region) and the second carrier filling portion 22 (filtration region) via the hole 42. Thereby, the smooth movement of the granular carrier between the first carrier filling portion 21 (aerobic treatment region) and the second carrier filling portion 22 (filtration region) is also maintained. Moreover, since the opening part 42 was provided in the partition 40, the structure which moves a to-be-processed sewage between the 1st carrier filling part 21 (aerobic treatment area | region) and the 2nd carrier filling part 22 (filtration area | region) is simple. is there.
Further, during the backwash operation, the time for maintaining the circulation of the sewage to be treated is extended as compared with the case where no opening is provided, and the carrier in the second carrier filling unit 22 (filtering region) is backwashed efficiently. Can do.
[0036]
In addition, this invention is not limited only to said embodiment, A various application and deformation | transformation can be considered.
[0037]
In the above embodiment, the case where the opening portion 42 is provided in the partition wall 40 is described. However, a member having a similar opening portion or a similar function may be provided in addition to the partition wall 40. For example, a path that communicates the first carrier filling portion 21 (aerobic treatment region) and the second carrier filling portion 22 (filtration region) is provided outside the carrier fluid biological filtration tank 10, and slits 42b and lattices 43b are provided in the passage. Can also be arranged.
[0038]
Moreover, in the said embodiment, by supplying air to the 1st support | carrier filling part 21 (aerobic process area | region) with an air diffuser, the 1st support | carrier filling part 21 (aerobic process area | region) and a 2nd support | carrier filling part Although the case where to-be-processed sewage is circulated between 22 (filtration area | region) was described, the means to circulate to-be-processed sewage is not limited to this, It can change variously as needed. For example, a circulation line may be provided in the tank body 12 and the wastewater to be treated in the tank body 12 may be circulated by a pump or the like.
[0039]
Moreover, although the said embodiment described the case where to-be-processed water passes the opening part 42, even when the water surface of the to-be-processed water in the carrier fluid biological filtration tank 10 exists above the top part 40a of the partition 40, it described. The first carrier filling portion 21 (aerobic treatment region) and the second carrier filling portion 22 (filtration region) are communicated only when the water level of the water to be treated is lower than the top 40a of the partition wall 40. You can also.
[0040]
【The invention's effect】
As described above, according to the present invention, in a sewage treatment apparatus having a treatment tank filled with a carrier on which microorganisms are implanted, circulation of treated sewage is maximized even when the surface of treated sewage fluctuates. The rational sewage treatment technology which performs a suitable process by maintaining can be implement | achieved.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a wastewater treatment process.
FIG. 2 is a schematic diagram of a carrier flow biological filtration tank 10. FIG.
FIG. 3 is a plan view showing a configuration of an aperture portion in FIG. 2;
FIG. 4 is a plan view showing a configuration of an aperture portion according to another embodiment.
FIG. 5 is a schematic diagram of the carrier fluid biological filtration tank 10 and shows a state during normal operation.
FIG. 6 is a schematic diagram of the carrier fluid biological filtration tank 10 and shows a state during a backwash operation.
FIG. 7 is a partially enlarged view of the carrier fluid biological filtration tank 10 and shows the state of movement of treated sewage when the water surface is higher than the top 40a of the partition wall 40.
FIG. 8 is a partially enlarged view of the carrier fluid biological filtration tank 10 and shows the state of movement of the sewage to be treated when the water surface is lower than the top 40a of the partition wall 40.
[Explanation of symbols]
10 ... Carrier fluid biological filtration tank (treatment tank)
11. Communication port (communication part)
DESCRIPTION OF SYMBOLS 12 ... Tank main body 18 ... Upper porous member 19 ... Lower porous member 20 ... Carrier filling area | region 21 ... 1st carrier filling part 22 ... 2nd carrier filling part 31 ... 1st air diffuser 32 ... 2nd air diffuser 40 ... Partition (Division member)
40a ... Top 41 ... Partition 42, 43 ... Opening 42a, 43a ... Frame 42b ... Slit 43b ... Lattice C, C1, C2 ... Granular carrier S ... Deposited layer

Claims

A treatment tank in which a carrier on which aerobic microorganisms are implanted is filled in a space between the upper porous member and the lower porous member, an air diffuser for supplying air to the treatment tank, and a favorable treatment by the aerobic microorganisms. An aerobic treatment region for performing an aerobic treatment, a filtration region for filtering an object to be filtered, a partition wall installed in the upper porous member in the space, and a communication portion communicating the aerobic treatment region and the filtration region. Have
A sewage treatment apparatus configured to circulate between the aerobic treatment region and the filtration region so that treated sewage passes over the top of the partition wall by the air flow of the air diffuser,
The partition has a partition part through which the treated sewage and the carrier do not pass, and an opening part that allows the treated sewage to pass through and prevents the carrier from passing through. It is configured to divide the aerobic treatment region and the filtration region,
The communication part is provided below the partition part,
In the partition, the opening is provided below the top of the partition and between the upper porous member and the partition, and the treated sewage whose water surface is lower than the top is passed through the opening. The wastewater treatment apparatus is configured to move between the aerobic treatment region and the filtration region .

The sewage treatment apparatus according to claim 1,
In the upper part of the treatment tank, an inflow port is provided for allowing the treated sewage to flow into the space part from the equipment upstream equipment, and in the lower part of the treatment tank, an outlet for allowing the treated sewage to flow out from the space part. Provided,
The downstream side of the outlet is branched into an extraction path for sending treated water treated in the treatment tank to the equipment downstream equipment side, and a circulation path for sending the treated water to the equipment upstream equipment. Sewage treatment equipment.

A treatment tank filled with an aerobic microorganism-implanted carrier in a space between the upper porous member and the lower porous member, an air diffuser for supplying air to the treatment tank, and an aerobic treatment An air treatment region, a filtration region for performing filtration, a partition wall installed in the upper porous member in the space portion, and a communication portion for communicating the aerobic treatment region and the filtration region;
The partition wall has a partition portion through which the treated sewage and the end body do not pass, and an opening portion that allows the treated sewage to pass through and prevents the carrier from passing, and the partition portion allows the space portion to be It is configured to partition into an aerobic treatment region and the filtration region,
While providing the communication part below the partition part,
In the partition, the opening is provided below the top of the partition and between the upper porous member and the partition,
In the first treatment process, air is supplied from the air diffuser to the aerobic treatment region, and the treated sewage whose water surface is lower than the top of the partition wall is passed through the aperture and the communication part. It is circulated between an air treatment region and the filtration region, the treated sewage is subjected to an aerobic treatment by an aerobic microorganism in the aerobic treatment region, and an object to be filtered is filtered by a carrier in the filtration region. Sewage treatment method.

A method for treating sewage according to claim 3 ,
In the second treatment step, air is supplied from the air diffuser to the filtration region, and the treated sewage whose water surface is lower than the top of the partition wall is treated with the aerobic treatment via the opening and the communication part. Circulating between the region and the filtration region, causing the carrier in the filtration region to flow, separating the material to be filtered from the carrier, and extracting the material to be filtered from the treatment tank Method.