JP4222822B2

JP4222822B2 - Septic tank and sewage treatment method

Info

Publication number: JP4222822B2
Application number: JP2002346125A
Authority: JP
Inventors: 早百合藤田; 光之山田; 康一松尾; 真一水野; 伸悟永峯; 宏司高橋; 俊之岩間
Original assignee: FUJICLEAN CO., LTD.
Current assignee: FUJICLEAN CO., LTD.
Priority date: 2002-11-28
Filing date: 2002-11-28
Publication date: 2009-02-12
Anticipated expiration: 2022-11-28
Also published as: JP2004174433A

Description

【０００１】
【発明の属する技術分野】
本発明は生物濾過処理槽を有する浄化槽の構築技術に関し、詳しくは生物濾過処理槽における被処理水処理の一層の合理化に資する浄化槽の構築技術に関する。
【０００２】
【従来の技術】
特開２００１−２４６３９２号公報では、好気処理槽を有する浄化槽の一例が開示されている。この浄化槽における好気処理槽では、上下二段の区画室が形成されている。このうち上段側区画室は、充填材を固定的に充填して固定床とした好気処理室とされ、下段側区画室は、流動性充填材を充填して半固定床とした濾過室とされている。そして通常運転時には、好気処理室で好気処理された被処理水が、下方の濾過処理室に流通して適宜濾過処理されるよう構成される。
【０００３】
かかる従来の浄化槽によれば、被処理水は好気処理された後で濾過処理され、しかる後で下流側処理槽へ移送されるよう構成される、かかる処理を一層効率化するための工夫、および浄化槽におけるエネルギ効率を一層向上するための工夫を講じた浄化槽の構築が更に望まれる。
【０００４】
【特許文献１】
特開２００１−２４６３９２号公報
【０００５】
【発明が解決しようとする課題】
本発明は、かかる点に鑑みてなされたものであり、生物濾過処理の効率を一層向上するとともに、浄化槽におけるエネルギ効率を一層向上することが可能な浄化槽の構築技術を提供することを目的とする。
【０００６】
【課題を解決するための手段】
上記課題を達成するため、各請求項記載の発明が構成される。
本発明によれば、生物処理領域と濾過処理領域とが形成された生物濾過処理槽を有する浄化槽が構成される。「浄化槽」としては、被処理水の汚濁物質濃度の高低を問わず各種の浄化槽が包含され得る。また本発明における「生物処理」の典型としては、槽内の好気性微生物に酸素を供給することで被処理水に対する好気処理（酸化処理の一種であり、散気処理とも称呼される）がこれに該当する。
【０００７】
本発明における浄化槽は、生物処理領域と濾過処理領域とを区画する仕切壁と、仕切壁の上方の上方移流部と、仕切壁の下方の下方移流部を備える。本発明における生物濾過処理槽の生物処理領域には、被処理水中での流動が規制された固定床が形成される。生物処理領域を固定床で構成することにより、流動床の場合と比較して、濾材表面に生物膜を早く形成することが可能であり、生物処理の立ち上げを早めることが可能となる。「固定床」の形成態様としては、例えば一体型の固定床を槽内に配置して処理領域を形成する態様のみならず、多数の担体を稠密状に充填して固定床を形成する態様が可能であるが、特に前者による場合、被処理水の流動を許容しつつ担体の流動を防止するための多孔板を生物処理領域上端領域および下端領域に配置する必要がないため、浄化槽構造の一層の合理化に資することとなる。
【０００８】
なお、当該生物処理領域の固定床の比表面積の設定についは、生物処理を遂行するための微生物の有効付着面積の確保およびコストのバランスを図る見地より、４０〜４００ｍ^２／ｍ^３程度とするのが好ましく、特にコストパフォーマンスを最大限に奏する見地からすれば１００〜３００ｍ^２／ｍ^３程度に設定するのが更に好ましい。
【０００９】
さらに本発明に係る浄化槽では、生物処理領域と濾過処理領域との間で上方移流部及び下方移流部を通じて被処理水のみの移流が可能とされ、これにより生物濾過処理槽内に、被処理水を生物処理領域から濾過処理領域へ移送するとともに生物処理領域へ還流するよう旋回流が形成される。かかる旋回流を介して被処理水の流動を円滑に行なうことが可能となるため、浄化槽駆動のためのエネルギ効率を大幅に向上することができるとともに、旋回流によって濾過処理に供された被処理水を、さらに生物処理領域に還流することで生物処理を重畳的に行なうことが可能であり、被処理水の処理効率に優れることとなる。
【００１０】
本発明によれば、前記の浄化槽における生物処理領域と濾過処理領域とは並列状に配設される。また生物処理領域の下方にはエア供給手段が配置される。エア供給手段からのエア上向流は、生物処理領域における生物処理を遂行するとともに、生物濾過処理槽内に旋回流を形成する。エア供給手段がエア上向流を供給することで、生物処理領域において被処理水に好気処理が施されることとなる。しかも当該エア上向流によって生物濾過処理槽内に旋回流が形成されるので、好気処理を行うためのエア流を旋回流形成の駆動源と兼務させることで、浄化槽のエネルギ効率を一層向上することが可能となる。なお生物処理領域および濾過処理領域は並列して配置されれば足り、互いに隣接する形態、並列するものの離間して配置される形態のいずれをも包含する。
【００１１】
本発明によれば、前記の浄化槽における濾過処理領域には、被処理水中での流動が規制された固定床が形成される。濾過処理領域を固定床によって構成することにより、当該濾過処理領域が閉塞され難くなり、濾過処理領域の洗浄頻度を低減することができる。「固定床」の形成態様としては、例えば一体型の固定床を槽内に配置して処理領域を形成する態様のみならず、多数の担体を稠密状に充填して固定床を形成する態様が可能であるが、特に前者による場合、被処理水の流動を許容しつつ担体の流動を防止するための多孔板を生物処理領域上端領域および下端領域に配置する必要がないため、浄化槽構造の一層の合理化に資することとなる。なお、当該濾過処理領域の濾材比表面積の設定についは、濾過処理能力を高水準で保持する見地より、４０〜４００ｍ^２／ｍ^３程度とするのが好ましく、特に閉塞回避との均衡を考慮すれば、１００〜３００ｍ^２／ｍ^３程度に設定するのが更に好ましい。
【００１２】
本発明によれば、前記の浄化槽において、旋回流の単位時間当たりの流量を増大することで濾過処理領域が洗浄されるように構成される。上記のように濾過処理領域を固定床で構成した場合であっても、当該濾過処理領域の洗浄頻度が低減されるとはいえ、洗浄の必要性を完全に払拭することは困難である。本発明によれば、旋回流の容量を適宜コントロールすることで濾過処理領域の洗浄作用を兼務させることが可能となり、浄化槽構造の一層の合理化に資することとなる。
【００１３】
本発明によれば、前記の浄化槽における濾過処理領域には、被処理水中での流動が許容される粒状の担体が多数充填された流動床が形成される。濾過処理領域を多数の粒状担体が充填された流動床で構成することにより、固定床で構成する場合に比べて濾材比表面積を大幅に増大し、濾過処理能力を向上することが可能である。その一方、濾材比表面積の増大により濾過処理領域による濾過処理量が増大するため、本発明では、濾過処理領域を洗浄するためのエア供給手段が設定されることとなる。
【００１４】
本発明によれば、前記の浄化槽と実質的に同等の構成を有する浄化槽を用いた合理的な汚水の処理方法が構成される。
【００１５】
【発明の実施の形態】
以下、本発明の実施の形態である浄化槽、および当該浄化槽に設けられる生物濾過処理槽の詳細につき、図面を参照しつつ説明する。
図１に模式的に示すように、本実施の形態に係る浄化槽１０１は、浄化槽ハウジング１０２内に各種の機能を奏する処理槽が配置されてなる。処理槽は、浄化槽ハウジング１０２に流入する被処理水の処理流路１１７の上流側から順に、夾雑物除去槽１０３、嫌気濾床槽１０５、好気処理槽１０７、処理水槽１０９、消毒槽１１１という順で配置される。図１において流入部１１３から浄化槽１０１に流入した被処理水については、まず夾雑物除去槽１０３において、被処理水中の比較的大きめの固形物あるいは油脂等が固液分離されて当該被処理水から除去される。
【００１６】
夾雑物除去槽１０３で処理された被処理水は、次に嫌気濾床槽１０５へ移流される。嫌気濾床槽１０５内の濾床には、特に図示しないものの、有機汚濁物を嫌気処理（還元処理）する嫌気性微生物が付着した濾材が設けられており、被処理水中の有機汚濁物が当該嫌気濾床槽１０５内の嫌気性微生物によって適宜嫌気処理されることになる。嫌気濾床槽１０５において嫌気処理された被処理水は、次に好気処理槽１０７に移流される。さらに好気処理槽１０７から処理水槽１０９へ移送された被処理水は、消毒槽１１１において消毒処理を受けた後、浄化槽ハウジング１０２に付設された放流ポンプ槽１１５に送られ、当該放流ポンプ槽１１５から浄化槽１０１外部に放流される。
【００１７】
本発明の特徴的構成要素である好気処理槽１０７の詳細な構成が図２に示される。好気処理槽１０７は、本発明における「生物濾過処理槽」の一例に対応している。好気処理槽１０７は、仕切壁１２１を介して区画され、相互に並列状に配置された好気処理領域１２３および濾過処理領域１２５を有する。そして好気処理槽１０７内の被処理水は、仕切壁１２１よりも上方に水位境界線ＷＬを形成する。好気処理領域１２３内の被処理水の水位と、濾過処理領域１２５内の被処理水の水位、および処理水槽１０９内の被処理水の水位はいずれも等しくなるように構成される。
【００１８】
好気処理領域１２３内および濾過処理領域１２５内には、それぞれ固定床１２４，１２６が配置されている。固定床１２４，１２６は、槽内の被処理水に対する流動が規制された多孔性のプレート部材の集合体として構成されるとともに、特に図示しない取付ブラケットを介して好気処理槽１０７本体部に止着される。本実施の形態では、各固定床１２４，１２６は、それぞれポリエチレンを多孔プレート状に成形して構成されるととともに、比表面積については概ね４０〜４００ｍ^２／ｍ^３程度の範囲から適宜選択して採用される。なおコストパフォーマンスおよび処理効率の均衡を特に重視するならば、１００〜３００ｍ^２／ｍ^３程度の範囲から選択することが望ましい。
【００１９】
好気処理槽１０７内の被処理水は、好気処理領域１２３と濾過処理領域１２５との間で、上方移流部１３３および下方移流部１３５を通じて移流可能とされている。また好気処理槽１０７と、その下流側に設定される処理水槽１０９とは、処理水槽移流部１４１で連接されている。処理水槽移流部１４１は、図１に示す処理流路１１７の一部をなす。具体的には濾過処理領域１２５内の固定床１２６の下部領域と、処理水槽１０９の下部領域とが処理水槽移流部１４１で連接され、好気処理槽１０７内の被処理水は、この処理水槽移流部１４１を経由して処理水槽１０９に移流し、さらに処理水槽１０９内を上向していく構成とされている。
【００２０】
好気処理槽１０７の処理水槽移流部１４１近傍には、被処理水移送用エアリフトポンプ１４３が設置されている。被処理水移送用エアリフトポンプ１４３は、移送管１４５を介して夾雑物除去槽１０３（図１参照）に接続される。これにより、濾過処理領域１２５から処理水槽１０９側へと移流されようとする被処理水の一部は、当該被処理水移送用エアリフトポンプ１４３および移送管１４５を介して夾雑物除去槽１０３（図１参照）へ還流され、浄化槽１０１の各処理槽における処理を重畳的に受けることになる。
【００２１】
好気処理領域１２３内の固定床１２４の下方には、ブロワ１５１に連接されたエア供給手段１５３が設けられている。エア供給手段１５３は、特に図示しないものの多数の細孔が穿設された管状部材として構成されるとともに、ブロワ１５１から供給されたエアをエア流１５５として好気処理領域１２３内に吐出する。本実施の形態では、エア供給手段１５３からのエア供給量として１分あたり概ね４０リットルの流量設定とされている。
【００２２】
次に本実施の形態に係る浄化槽１０１の作用および使用方法について詳細に説明する。図１に示すように、流入部１１３を通じて浄化槽ハウジング１０２内の夾雑物除去槽１０３に流入した汚水等の被処理水に対し、当該夾雑物除去１０３内にて比較的大きめの固形物あるいは油脂等の固液分離処理がなされる。
【００２３】
夾雑物除去槽１０３で固液分離処理された被処理水は、嫌気濾床槽１０５へ移流され、当該被処理水中の有機汚濁物が当該嫌気濾床槽１０５内の嫌気性微生物によって嫌気処理される。嫌気濾床槽１０５において嫌気処理された被処理水は、処理流路１１７を通じて好気処理槽１０７に移流される。
【００２４】
次に、本実施の形態の好気処理槽１０７における各要素の作用について説明する。なお図２は、好気処理槽１０７にて好気処理が遂行される際の状態を示すものであり、さらに図２において被処理水の流れは白抜きの矢印で適宜示されている。図２から理解されるように、好気処理領域１２３において好気処理を行うには、当該好気処理領域１２３内の固定床１２４に付着した好気性微生物に酸素を供給するべく、好気処理領域１２３へとエア供給手段１５３からエア流１５５が吐出される。このエア流１５５は好気処理領域１２３内を上昇する上向流１５５ａを規定することとなる。
【００２５】
好気処理領域１２３内の固定床１２４には多数の好気性微生物が付着しており、当該好気性微生物は、上向流１５５ａによる酸素の供給を受けて好気処理領域１２３内の被処理水に対し好気性処理（酸化処理）を行う。
【００２６】
好気処理領域１２３における好気性処理で生じたＳＳ（Suspended Solid）等の固形生成物は、好気処理領域１２３内に生じた上向流１５５ａにより、好気処理領域１２３内の被処理水とともに、上方移流部１３３を経由して濾過処理領域１２５に移送される。このとき好気処理槽１０７内の被処理水の水位線ＷＬは、仕切壁１２１よりも上位に位置し、被処理水が上方移流部１３３を通過するのを許容する。
【００２７】
好気処理領域１２３における上向流１５５ａが上方移流部１３３を通じて濾過処理領域１２５に流れ込むことにより、濾過処理領域１２５内には下向流１５５ｂが形成される。そして好気処理領域１２３における好気処理で生じた固形生成物ならびに被処理水に含有される他の固形成分は、この下向流１５５ｂに従って濾過処理領域１２５内を下方に移動しつつ、濾過処理領域１２５内の固定床１２６に適宜捕捉されることとなる。
【００２８】
下向流１５５ｂによって濾過処理領域１２５を下方に移動した被処理水は、一部が下方移流部１３５を経由して好気処理領域１２３に還流し、残りの部分は処理水槽移流部１４１を経由して濾過処理領域１２５下部から処理水槽１０９へ移流される。
【００２９】
本実施の形態では、好気処理領域１２３に固定床１２４を用いているため、流動床の場合と比較して、当該固定床１２４の表面に好気性微生物の生物膜を早く形成することが可能であり、好気処理の立ち上げを早めることが可能である。しかも固定床１２４の比表面積を適宜選定することにより、好気処理能力の向上および目詰まりによる好気処理領域１２３の閉塞回避という背反することになり易い要請を、最適状態にてバランスさせることが容易に行なえる。
【００３０】
さらに本実施の形態では、エア供給手段１５３から吐出されたエア流１５５により、好気処理領域１２３内の上向流１５５ａ、上方移流部１３３における好気処理領域１２３から濾過処理領域１２５方向への流れ（図中右方向への流れ）、濾過処理領域１２５内の下向流１５５ｂ、下方移流部１３５における濾過処理領域１２５から好気処理領域１２３方向への流れ（図中左方向への流れ）が形成され、これにより好気処理領域１２３から濾過処理領域１２５へ、そして濾過処理領域１２５から好気処理領域１２３へと被処理水が循環する旋回流１５９を形成されることなる。
【００３１】
かくして浄化槽１０１の散気運転時（通常運転時）には、エア供給手段１５３からエア流１５５が好気処理領域１２３に供給され、当該エア流１５５によって好気処理領域１２３内に上向流１５５ａが形成されるとともに、当該上向流１５５ａによって好気処理領域１２３および濾過処理領域１２５間に被処理水の旋回流１５７が形成されることとなる。これにより、本来は好気処理領域１２３における好気性微生物への酸素の供給のために用いられるべきエア流につき、好気処理領域１２３から濾過処理領域１２５への被処理水移送手段を兼務させることが可能となり、浄化槽１０１におけるエネルギ効率の向上を図ることが可能となる。
【００３２】
しかも当該旋回流１５９により、濾過処理領域１２５において濾過処理を受けた被処理水の一部は、再び好気処理領域１２３に還流されて好気性処理を受けることになる。すなわち旋回流１５９の形成により、被処理水に対する生物処理および濾過処理を重畳的に繰り返すことによって、生物処理および濾過処理の効果を高めることが可能となる。
【００３３】
ところで上記散気運転による生物処理が進行した場合、濾過処理領域１２５内の固定床１２６によるＳＳ等の固形成分の捕捉量が増大することに起因して、当該固定床１２６の目詰まりが生じる可能性がある。この対策として、本実施の形態に係る浄化槽１０１では、エア供給手段１５３によるエア流１５５の単位時間当たりの流量を増大し、旋回流１５９の流量を強くすることでこれに対処している。すなわち通常の好気処理時に比べて大容量の旋回流を好気処理槽１０７内に循環させることで濾過処理領域１２５における下向流の単位時間当たりの流量を大きくし、これによって濾過処理領域１２５内の固定床１２６に捕捉された固形生成物を除去する。本実施の形態では濾過処理領域１２５洗浄の際に、ブロワ１５１からの単位時間当たりのエア供給量が好気処理時の概ね二倍となるように設定されている。
【００３４】
濾過処理領域１２５を洗浄した洗浄水は、当該濾過処理領域１２５の下部領域、すなわち旋回流１５９の下流側から被処理水移送用エアリフトポンプ１４３および移送管１４５を介して夾雑物除去槽１０３（図１参照）へ還流され、浄化槽１０１の各処理槽における処理を受けることになる。なお、濾過処理領域１２５を洗浄する際も、被処理水は処理流路１１７から好気処理槽１０７へと規制を受けることなく流入するため、洗浄水の引き抜きによって好気処理槽１０７内の水位が急減するといった事態は生じない。
【００３５】
本実施の形態では、濾過処理領域１２５を洗浄するのに旋回流１５９の流量を増大するのみで対処可能であり、浄化槽１０１の構造の一層の合理化に資することとなる。また旋回流１５９を介して、単に濾過処理領域１２５のみならず更に好気処理領域１２３の洗浄効果も得ることが可能となる。さらに濾過処理領域１２５（および好気処理領域１２３）を洗浄した洗浄水を旋回流１５９の下流領域である濾過処理領域１２３の下部領域から被処理水移送用エアリフトポンプ１４３で引き抜くため、固形成分を多量に包含した洗浄水が好気処理槽１０７内に徒に拡散するのを極力抑制することが可能となる。
【００３６】
（第２の実施形態）
次に本発明に第２の実施形態につき、図３および図４を参照しつつ説明する。第２の実施形態は、上記第１の実施形態における濾過処理領域１２５の構造変更に関する。従って、第１の実施形態と実質的に同等の要素については、便宜上、同等の符号を用いるとともに、詳細な説明を省略することとする。第２の実施形態に係る浄化槽２０１では、好気処理槽２０７中の濾過処理領域１２５につき、上記固定床１２６に代えて、流動式担体床が採用されている（すなわち第２の実施形態では、好気処理領域１２３には固定床１２６が設定される一方、濾過処理領域１２５には流動式担体床が設定される）。具体的には、図３に示すように、濾過処理領域１２５の上端部および下端部にそれぞれ上方多孔板２２７および下方多孔板２２９が配置されるとともに、当該上方多孔板２２７と下方多孔板２２９間に形成される空間領域に粒状の担体２２６が多数充填されて流動式担体床が構成される。各多孔板２２７，２２９には被処理水の流通を許容するとともに、担体２２６の流通を規制するように適宜設定された孔部が多数穿設されている。
【００３７】
また好気処理領域１２３の下方側にはブロワ１５１に連接されたエア供給手段２５３ａが配設される一方、濾過処理領域１２５における下方多孔板２２９の下方側にはブロワ１５１に連接された第２のエア供給手段２５３ｂが配設される。第１および第２のエア供給手段２５３ａ，２５３ｂの構成については上記第１の実施形態におけるエア供給手段１５３と実質的に同等ゆえに詳細な説明を省略する。また第２の実施形態の他の構成についても、上記第１の実施形態における構成と同等の内容を有するため、詳細な説明を省略する。
【００３８】
上記のように構成される第２の実施形態に係る浄化槽２０１において好気処理を行なう際には、図３に示すように、好気処理領域１２３の下部に配された第１のエア供給手段２５３ａから当該好気処理領域１２３にエア流１５５を供給する。このエア流１５５により、好気処理槽２０７内では、好気処理領域１２３に上向流１５５ａ、濾過処理領域１２５に下向流１５５ｂがそれぞれ作用する旋回流１５９が形成される。このとき濾過処理領域１２５の各担体２２６は、下向流１５５ｂによって濾過処理領域１２５下方側への流動圧力を受けることで下方多孔板２２９に支承されて濾床を形成し、これによって被処理水中の固形成分を捕捉して濾過処理を遂行する。
【００３９】
第２の実施形態によれば、上記第１の実施形態と同様に、旋回流１５９による効果および固定床１２６を用いた好気処理領域１２３の効果が得られることの他に、濾過処理領域１２５を流動式担体床で構成したことにより、当該濾過処理領域１２５の実質的な濾過面積を大幅に向上することが可能となり、濾過処理能力に優れた浄化槽２０１が得られる。
【００４０】
一方、濾過処理能力の向上に伴い、濾過処理が経時的に進行するにつれて、濾過処理領域１２５内の充填担体２２６が大量の濾過物を補足することに起因して目詰まりを生じ得る。そこで第２の実施形態では、図４に示すように、定期的に第２のエア供給手段２５３ｂから強いエア流２５６を濾過処理領域１２５に吐出する。このエア流２５６により、濾過処理領域１２５内には強い上向流２５６ｂが形成されるとともに、上方移流部１３３を通じて好気処理領域１２３に強い下向流２５６ａを生じさせつつ、下方移流部１３５を経由して循環することで、好気処理槽２０７内に強い旋回流２６０が形成される。
【００４１】
この旋回流２６０は、上向流２５６ｂによって濾過処理領域１２５内の各担体２２６を当該濾過処理領域１２５内（上方多孔板２２７と下方多孔板２２９間の空間領域内）で流動させつつ洗浄し、上記した好気処理時の旋回流１５９とは逆方向（図中反時計回り）に好気処理槽２０７内を流動していく。これにより担体２２６の洗浄水は、さらに好気処理領域１２３内の固定床１２６に対する洗浄作用も奏しつつ下方移流部１３５を経由して濾過処理領域１２５の下方、すなわち逆方向旋回流２６０の下流側領域に至り、そこから被処理水移送用エアリフトポンプ１４３及び移送管１４５を介して上流側処理槽に還流されることとなる。
【００４２】
（第３の実施形態）
次に本発明に第３の実施形態につき、図５および図６を参照しつつ説明する。第３の実施形態は、上記第１および第２の実施形態における好気処理領域１２３の構造変更に関する。従って、第１および第２の実施形態と実質的に同等の要素については、便宜上、詳細な説明を省略することとする。
【００４３】
第３の実施形態に係る浄化槽３０１に関し、図５では、好気処理槽３０７を用いて被処理水の好気処理を遂行する際の状態が示され、図６では濾過処理領域３２５の洗浄が遂行される際の状態が示される。
【００４４】
第３の実施形態では、浄化槽３０１内の好気処理槽３０７における好気処理領域３２３につき、多数の担体３２６を当該好気処理領域３２３中に流動不能に充填することで固定床を形成している。具体的には、図５に示すように、好気処理領域３２３の上端部・下端部、あるいはそれらの近傍に、それぞれ上方多孔板３２７および下方多孔板３２９を配設することで、当該上方多孔板３２７と下方多孔板３２９間に形成される空間領域に粒状の担体３２６を稠密状に充填する。この結果、各担体３２６は互いに当接し合うことで被処理水内での自由な流動が規制された状態とされる。すなわち第３の実施形態では、粒状の担体３２６を多数充填することで、好気性微生物が付着するための実質的な表面積を大幅に増大しつつも、担体３２６が被処理水に対して流動するのを規制して生物膜の生成速度を速めることが可能とされる。また好気処理領域３２３および濾過処理領域３２５の下方にはそれぞれエア供給手段３５３ａ，３５３ｂが配設されている。
【００４５】
上記のように構成される第３の実施形態に係る浄化槽３０１を用いて好気処理を行なう場合、図５に示すように、好気処理領域３２３の下部に配置されたエア供給手段３５３ａから当該好気処理領域３２３にエア流３５５を供給し、これによって好気処理槽３０７内には、好気処理領域１２３に上向流１５５ａ、濾過処理領域１２５に下向流１５５ｂがそれぞれ作用する旋回流１５９が形成される。このとき、好気処理領域３２３内の各担体３２６は被処理水に対する自由な流動が規制された状態とされているため、当該好気処理領域３２３を上昇する上向流３５５ａに対しては固定床状に作用しつつ好気処理を遂行する。また濾過処理領域３２５では、下向流１５５ｂにより各担体２２６は濾過処理領域３２５下方に押圧されつつ下方多孔板２２９に支承されて濾床を形成し、これによって被処理水中の固形成分を捕捉して濾過処理を遂行する。
【００４６】
第３の実施形態によれば、上記第１および第２に実施形態における固定床１２４による好気処理領域１２３の構成とは異なり、被処理水に対する流動が規制された多数の担体を固定状に充填して好気処理領域３２３を形成する構成により、当該好気処理領域３２３の実質的な比表面積の大幅向上を図ることが可能となり、好気処理能力に優れた構成が得られる。
【００４７】
なお第３の実施形態では、上記第２の実施形態と同様に、濾過処理領域３２５を流動式担体床で形成することに起因して、濾過処理の経時的進行とともに濾過処理領域３２５における担体３２６に濾過物による目詰まりの問題が生じ得る。従って第３の実施形態では、図６に示すように、定期的に第２のエア供給手段３５３ｂから強いエア流３５６を濾過処理領域３２５に吐出する。このエア流３５６により、濾過処理領域３２５内には強い上向流３５６ｂが形成されるとともに、当該上向流３５６ｂが上方移流部１３３を通じて好気処理領域３２３に強い下向流３５６ａを生じさせつつ、下方移流部１３５を経由して循環することで、好気処理槽３０７内に強い旋回流３６０が形成される。
【００４８】
この旋回流３６０は、上向流３５６ｂによって濾過処理領域３２５内の各担体３２６を当該濾過処理領域３２５内で流動させつつ洗浄し、上記した好気処理時の旋回流３５９とは逆方向（図中反時計回り）に好気処理槽３０７内を流動していく。これにより担体３２６の洗浄水は、さらに好気処理領域３２３内の各担体３２６に対する洗浄作用も奏しつつ下方移流部１３５を経由して濾過処理領域３２５の下方、すなわち逆方向旋回流３６０の下流側領域に至り、そこから被処理水移送用エアリフトポンプ１４３及び移送管１４５を介して上流側処理槽に還流されることとなる。なお当該逆方向旋回流３６０に対しても好気処理領域３２３内の担体３２６は流動が規制された状態を維持するため、担体３２６表面に形成された生物膜が必要以上に剥離するといった事態が未然に防止可能である。
【００４９】
上記した各実施の形態については、本発明の要旨の範囲内において下記のように様々な変更を行うことができる。例えば、好気処理領域１２３については担体を流動規制しつつ稠密状に充填して固定床を形成する一方、濾過処理領域１２５については槽本体に止着可能なプレート状の固定床を用いて形成するといった構成を採用してもよい。あるいは濾過処理領域１２５について、担体を流動規制しつつ稠密状に充填して固定床を形成する構成を採用してもよい。
【００５０】
また第２および第３の実施形態に係るブロワ１５１につき、それぞれ好気処理領域用及び濾過処理領域用と、独立して配置する構成を採用してもよいし、タイマーおよび位相制御手段を適宜利用して、単一のブロワを時間制御および風量制御して対応してもよい。また、被処理水移送用エアリフトポンプ１４３の駆動を兼務可能なブロワを用いて構成してもよい。
【００５１】
また被処理水の移送に関し、本実施の形態では一の被処理水移送用エアリフトポンプ１４３によって散気運転時および濾過処理領域洗浄時の双方における引き抜き・移送を行ったが、これを別々に設置してもよい。
【００５２】
なお処理水移送用エアリフトポンプ１４３によって、被処理水を好気処理槽１０７よりも上流側の処理槽であって、夾雑物除去槽１０３以外の処理槽、例えば嫌気濾床槽１０５に還流する構成も採用可能である。また好気処理槽１０７（および２０７，３０７）において仕切壁１２１を省略する構成も採用可能である。
【００５３】
さらに上記第２および第３の実施形態では、濾過処理領域１２５，３２５を洗浄する際に逆方向旋回流を利用する形態を採用したが、例えば濾過処理領域１２５，３２５における洗浄水が好気処理槽２０７，３０７に拡散するのを極力抑制する見地からは、旋回流を利用せず、濾過処理領域１２５，３２５の洗浄水が好気処理領域１２３，３２３側に流出しないように規制する構成を採用することも可能である。
【００５４】
【発明の効果】
本発明によれば、生物濾過処理槽を有する浄化槽において、生物濾過処理の効率を一層向上するとともに、浄化槽におけるエネルギ効率を一層向上することが可能な浄化槽の構築技術が提供されることとなった。
【図面の簡単な説明】
【図１】本発明の実施の形態に係る浄化槽の全体構成を示す。
【図２】本発明の実施の形態に係る生物濾過処理槽につき、散気運転時の状態を示す。
【図３】本発明の第２の実施形態に係る生物濾過処理槽につき、散気運転時の状態を示す。
【図４】本発明の第２の実施形態に係る生物濾過処理槽につき、濾過処理領域洗浄時の状態を示す。
【図５】本発明の第３の実施形態に係る生物濾過処理槽につき、散気運転時の状態を示す。
【図６】本発明の第３の実施形態に係る生物濾過処理槽につき、濾過処理領域洗浄時の状態を示す。
【符号の説明】
１０１浄化槽
１０２浄化槽ハウジング
１０３夾雑物除去槽
１０５嫌気濾床槽
１０７生物濾過処理槽
１０９処理水槽
１１１消毒槽
１１３流入部
１１５放流ポンプ
１１７処理流路
１１９被処理水
１２１仕切壁
１２３生物処理領域
１２４固定床
１２５濾過処理領域
１２６固定床
１３３上方移流部
１３５下方移流部
１４１処理水槽移流部
１４３被処理水移送用エアリフトポンプ
１４５移送管
１５１ブロワ
１５３エア供給手段
１５５上向流
１５７下降流
１５９旋回流
２２６粒状担体
２２７上方多孔板
２２９下方多孔板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technology for constructing a septic tank having a biological filtration treatment tank, and more particularly, to a technology for constructing a septic tank that contributes to further rationalization of water treatment in a biological filtration treatment tank.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 2001-246392 discloses an example of a septic tank having an aerobic treatment tank. In the aerobic treatment tank in this septic tank, upper and lower two-stage compartments are formed. Of these, the upper compartment is an aerobic treatment chamber that is fixedly filled with a filler and is a fixed bed, and the lower compartment is a filtration chamber that is filled with a fluid filler and is a semi-fixed bed. Has been. During normal operation, the water to be treated that has been aerobically treated in the aerobic treatment chamber flows into the lower filtration treatment chamber and is appropriately filtered.
[0003]
According to such a conventional septic tank, the water to be treated is filtered after being subjected to an aerobic treatment, and then transferred to a downstream treatment tank, and a device for further increasing the efficiency of such treatment, It is further desired to construct a septic tank that has been devised to further improve the energy efficiency of the septic tank.
[0004]
[Patent Document 1]
JP 2001-246392 A
[0005]
[Problems to be solved by the invention]
This invention is made | formed in view of this point, and it aims at providing the construction technology of the septic tank which can improve the energy efficiency in a septic tank further while improving the efficiency of biological filtration processing further. .
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in each claim is configured.
According to the present invention, a septic tank having a biological filtration treatment tank in which a biological treatment region and a filtration treatment region are formed is configured. The “septic tank” may include various septic tanks regardless of the level of contaminants in the water to be treated. In addition, as a typical example of “biological treatment” in the present invention, an aerobic treatment (a kind of oxidation treatment, also referred to as aeration treatment) is performed on water to be treated by supplying oxygen to aerobic microorganisms in the tank. This is the case.
[0007]
The septic tank in this invention is provided with the partition wall which divides a biological treatment area | region and a filtration process area | region, the upper advection part above a partition wall, and the lower advection part below a partition wall. In the biological treatment region of the biological filtration treatment tank according to the present invention, a fixed bed in which flow in the treated water is restricted is formed. By configuring the biological treatment region with a fixed bed, it is possible to form a biological film on the surface of the filter medium faster than in the case of a fluidized bed, and to speed up the start of biological treatment. As the formation mode of the “fixed bed”, for example, there is an embodiment in which a fixed bed is formed by densely filling a large number of carriers in addition to an embodiment in which an integrated fixed bed is arranged in a tank to form a treatment region. Although it is possible, especially in the former case, it is not necessary to arrange a perforated plate for preventing the flow of the carrier while allowing the flow of the water to be treated in the upper end region and the lower end region of the biological treatment region. It will contribute to rationalization.
[0008]
The specific surface area of the fixed bed in the biological treatment area is set to 40 to 400 m from the viewpoint of securing an effective adhesion area of microorganisms for performing biological treatment and balancing costs. ² / M ³ It is preferable to set it to about 100 to 300 m from the viewpoint of maximizing cost performance. ² / M ³ More preferably, the degree is set.
[0009]
Further, in the septic tank according to the present invention, only the water to be treated can be transferred between the biological treatment region and the filtration treatment region through the upper advection part and the lower advection part, and thereby, the treated water is placed in the biological filtration treatment tank. A swirling flow is formed so as to transfer the water from the biological treatment area to the filtration treatment area and to return to the biological treatment area. Since the water to be treated can be smoothly flowed through the swirl flow, the energy efficiency for driving the septic tank can be greatly improved, and the treatment to be subjected to the filtration process by the swirl flow Biological treatment can be performed in a superposed manner by returning water to the biological treatment region, and the treatment efficiency of the water to be treated is excellent.
[0010]
According to the present invention, the biological treatment area and the filtration treatment area in the septic tank are arranged in parallel. An air supply means is disposed below the biological treatment area. The air upward flow from the air supply means performs biological treatment in the biological treatment area and forms a swirl flow in the biological filtration treatment tank. When the air supply means supplies the air upward flow, the water to be treated is subjected to the aerobic treatment in the biological treatment region. In addition, a swirl flow is formed in the biological filtration treatment tank by the upward air flow, so that the energy efficiency of the septic tank is further improved by combining the air flow for performing the aerobic treatment with the drive source for the swirl flow formation. It becomes possible to do. The biological treatment area and the filtration treatment area need only be arranged in parallel, and include both forms that are adjacent to each other and forms that are arranged in parallel but are spaced apart.
[0011]
According to the present invention, a fixed bed in which flow in the water to be treated is restricted is formed in the filtration treatment region in the septic tank. By constituting the filtration treatment region with a fixed bed, the filtration treatment region is not easily blocked, and the frequency of cleaning the filtration treatment region can be reduced. As the formation mode of the “fixed bed”, for example, there is an embodiment in which a fixed bed is formed by densely filling a large number of carriers in addition to an embodiment in which an integrated fixed bed is arranged in a tank to form a treatment region. Although it is possible, especially in the former case, it is not necessary to arrange a perforated plate for preventing the flow of the carrier while allowing the flow of the water to be treated in the upper end region and the lower end region of the biological treatment region. It will contribute to rationalization. In addition, about the setting of the filter medium specific surface area of the said filtration process area | region, from the viewpoint of maintaining filtration processing capability at a high level, it is 40-400m. ² / M ³ It is preferable to set the degree to 100 to 300 m, especially considering the balance with blockage avoidance. ² / M ³ More preferably, the degree is set.
[0012]
According to the present invention, the septic tank is configured such that the filtration region is cleaned by increasing the flow rate per unit time of the swirling flow. Even when the filtration treatment area is configured as a fixed bed as described above, it is difficult to completely wipe out the necessity of washing, although the frequency of washing the filtration treatment area is reduced. According to the present invention, by appropriately controlling the volume of the swirling flow, it is possible to perform the cleaning operation of the filtration treatment region, which contributes to further rationalization of the septic tank structure.
[0013]
According to the present invention, a fluidized bed filled with a large number of granular carriers that are allowed to flow in the water to be treated is formed in the filtration region in the septic tank. By constituting the filtration treatment region with a fluidized bed filled with a large number of granular carriers, it is possible to significantly increase the filter medium specific surface area and improve the filtration treatment ability as compared with the case of constituting with a fixed bed. On the other hand, since the amount of filtration processing by the filtration treatment region increases due to the increase in the specific surface area of the filter medium, in the present invention, an air supply means for cleaning the filtration treatment region is set.
[0014]
According to the present invention, a rational sewage treatment method using a septic tank having a configuration substantially equivalent to that of the septic tank is configured.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the details of a septic tank according to an embodiment of the present invention and a biological filtration treatment tank provided in the septic tank will be described with reference to the drawings.
As schematically shown in FIG. 1, the septic tank 101 according to the present embodiment includes a processing tank having various functions disposed in a septic tank housing 102. The treatment tank is referred to as a contaminant removal tank 103, an anaerobic filter bed tank 105, an aerobic treatment tank 107, a treatment water tank 109, and a disinfection tank 111 in order from the upstream side of the treatment channel 117 of the water to be treated flowing into the septic tank housing 102. Arranged in order. In FIG. 1, the treated water that has flowed into the septic tank 101 from the inflow portion 113 is first separated from the treated water by solid-liquid separation of relatively large solids or oils and fats in the treated water in the contaminant removal tank 103. Removed.
[0016]
The treated water treated in the contaminant removal tank 103 is then transferred to the anaerobic filter bed tank 105. Although not particularly shown, the filter bed in the anaerobic filter bed tank 105 is provided with a filter medium to which anaerobic microorganisms for anaerobic treatment (reduction treatment) of organic contaminants are provided. An anaerobic treatment is appropriately performed by the anaerobic microorganisms in the anaerobic filter bed tank 105. The treated water that has been anaerobically treated in the anaerobic filter bed tank 105 is then transferred to the aerobic treatment tank 107. Further, the water to be treated transferred from the aerobic treatment tank 107 to the treatment water tank 109 is sterilized in the sterilization tank 111 and then sent to a discharge pump tank 115 attached to the septic tank housing 102, and the discharge pump tank 115. To the outside of the septic tank 101.
[0017]
A detailed configuration of the aerobic treatment tank 107, which is a characteristic component of the present invention, is shown in FIG. The aerobic treatment tank 107 corresponds to an example of the “biological filtration treatment tank” in the present invention. The aerobic treatment tank 107 is partitioned through a partition wall 121 and has an aerobic treatment region 123 and a filtration treatment region 125 arranged in parallel to each other. The water to be treated in the aerobic treatment tank 107 forms a water level boundary line WL above the partition wall 121. The water level in the aerobic treatment region 123, the water level in the filtration treatment region 125, and the water level in the treatment water tank 109 are configured to be equal.
[0018]
Fixed beds 124 and 126 are disposed in the aerobic treatment region 123 and the filtration treatment region 125, respectively. The fixed floors 124 and 126 are configured as an aggregate of porous plate members whose flow with respect to the water to be treated in the tank is restricted, and are fixed to the main body of the aerobic processing tank 107 via a mounting bracket (not shown). Worn. In the present embodiment, each of the fixed beds 124 and 126 is formed by molding polyethylene into a perforated plate, and the specific surface area is approximately 40 to 400 m. ² / M ³ It is appropriately selected from a range of degrees. If the balance between cost performance and processing efficiency is particularly important, 100-300m ² / M ³ It is desirable to select from a range of degrees.
[0019]
The water to be treated in the aerobic treatment tank 107 can be transferred between the aerobic treatment region 123 and the filtration treatment region 125 through the upper advection part 133 and the lower advection part 135. The aerobic treatment tank 107 and the treated water tank 109 set downstream thereof are connected by a treated water tank advection section 141. The treated water tank advection part 141 forms a part of the treatment channel 117 shown in FIG. Specifically, the lower region of the fixed bed 126 in the filtration treatment region 125 and the lower region of the treatment water tank 109 are connected by the treatment water tank advection unit 141, and the treated water in the aerobic treatment tank 107 is the treatment water tank. The water is transferred to the treated water tank 109 via the advection part 141 and further moved upward in the treated water tank 109.
[0020]
In the vicinity of the treated water tank advancing part 141 of the aerobic treatment tank 107, an air lift pump 143 for transferring treated water is installed. The to-be-treated water transfer air lift pump 143 is connected to the contaminant removal tank 103 (see FIG. 1) via the transfer pipe 145. As a result, a part of the water to be treated that is to be transferred from the filtration treatment region 125 to the treatment water tank 109 side through the air to be treated water transfer pump 143 and the transfer pipe 145 (see FIG. 1), and the treatment in each treatment tank of the septic tank 101 is received in a superimposed manner.
[0021]
An air supply unit 153 connected to the blower 151 is provided below the fixed floor 124 in the aerobic treatment region 123. Although not shown, the air supply means 153 is configured as a tubular member having a large number of pores, and discharges air supplied from the blower 151 into the aerobic treatment region 123 as an air flow 155. In the present embodiment, the air supply amount from the air supply means 153 is set to a flow rate of approximately 40 liters per minute.
[0022]
Next, the action and method of use of the septic tank 101 according to the present embodiment will be described in detail. As shown in FIG. 1, relatively large solids, oils and fats, etc. in the contaminant removal 103 with respect to water to be treated such as sewage flowing into the contaminant removal tank 103 in the septic tank housing 102 through the inflow portion 113. The solid-liquid separation process is performed.
[0023]
The treated water that has been subjected to the solid-liquid separation treatment in the contaminant removal tank 103 is transferred to the anaerobic filter bed tank 105, and the organic contaminants in the treated water are anaerobically treated by the anaerobic microorganisms in the anaerobic filter bed tank 105. The The water to be treated that has been anaerobically treated in the anaerobic filter bed tank 105 is transferred to the aerobic treatment tank 107 through the treatment channel 117.
[0024]
Next, the operation of each element in the aerobic treatment tank 107 of the present embodiment will be described. FIG. 2 shows a state when the aerobic treatment is performed in the aerobic treatment tank 107. Further, in FIG. 2, the flow of water to be treated is appropriately indicated by white arrows. As understood from FIG. 2, in order to perform the aerobic treatment in the aerobic treatment region 123, the aerobic treatment is performed in order to supply oxygen to the aerobic microorganisms attached to the fixed bed 124 in the aerobic treatment region 123. An air flow 155 is discharged from the air supply means 153 to the region 123. This air flow 155 defines an upward flow 155 a that rises in the aerobic treatment region 123.
[0025]
A large number of aerobic microorganisms adhere to the fixed bed 124 in the aerobic treatment region 123, and the aerobic microorganisms receive supply of oxygen by the upward flow 155a and are treated water in the aerobic treatment region 123. An aerobic treatment (oxidation treatment) is performed.
[0026]
Solid products such as SS (Suspended Solid) generated by the aerobic treatment in the aerobic treatment region 123 are combined with the water to be treated in the aerobic treatment region 123 by the upward flow 155a generated in the aerobic treatment region 123. Then, it is transferred to the filtration region 125 via the upper advection part 133. At this time, the water level line WL of the water to be treated in the aerobic treatment tank 107 is positioned higher than the partition wall 121 and allows the water to be treated to pass through the upper advection part 133.
[0027]
As the upward flow 155 a in the aerobic treatment region 123 flows into the filtration treatment region 125 through the upper advection part 133, a downward flow 155 b is formed in the filtration treatment region 125. The solid product generated by the aerobic treatment in the aerobic treatment region 123 and other solid components contained in the water to be treated move downward in the filtration treatment region 125 in accordance with the downward flow 155b, and the filtration treatment is performed. It will be appropriately captured by the fixed bed 126 in the region 125.
[0028]
The treated water that has moved downward in the filtration treatment area 125 by the downward flow 155b partially returns to the aerobic treatment area 123 via the lower advection part 135, and the remaining part passes through the treated water tank advection part 141. Then, the water is transferred from the lower part of the filtration treatment area 125 to the treatment water tank 109.
[0029]
In the present embodiment, since the fixed bed 124 is used in the aerobic treatment region 123, it is possible to form a biofilm of aerobic microorganisms on the surface of the fixed bed 124 faster than in the case of the fluidized bed. It is possible to accelerate the start of aerobic processing. In addition, by appropriately selecting the specific surface area of the fixed bed 124, it is possible to balance the requirements that are likely to be contradictory to the improvement of the aerobic treatment capacity and the prevention of the blockage of the aerobic treatment region 123 due to clogging in an optimal state. It can be done easily.
[0030]
Furthermore, in the present embodiment, the air flow 155 discharged from the air supply means 153 causes the upward flow 155a in the aerobic treatment region 123 to move from the aerobic treatment region 123 in the upper advection part 133 toward the filtration treatment region 125. Flow (flow to the right in the drawing), downward flow 155b in the filtration treatment region 125, flow from the filtration treatment region 125 to the aerobic treatment region 123 in the lower advection part 135 (flow to the left in the drawing) As a result, a swirling flow 159 in which the water to be treated circulates from the aerobic treatment region 123 to the filtration treatment region 125 and from the filtration treatment region 125 to the aerobic treatment region 123 is formed.
[0031]
Thus, during the aeration operation (normal operation) of the septic tank 101, the air flow 155 is supplied from the air supply means 153 to the aerobic treatment region 123, and the upward flow 155a into the aerobic treatment region 123 by the air flow 155. And the swirling flow 157 of the water to be treated is formed between the aerobic treatment region 123 and the filtration treatment region 125 by the upward flow 155a. Accordingly, the water flow to be used for the supply of oxygen to the aerobic microorganisms in the aerobic treatment region 123 is also used as the treated water transfer means from the aerobic treatment region 123 to the filtration treatment region 125. Thus, it is possible to improve the energy efficiency in the septic tank 101.
[0032]
Moreover, due to the swirl flow 159, part of the water to be treated that has undergone the filtration treatment in the filtration treatment region 125 is returned to the aerobic treatment region 123 and undergoes the aerobic treatment. That is, by forming the swirl flow 159, it is possible to enhance the effects of the biological treatment and the filtration treatment by repeatedly performing the biological treatment and the filtration treatment on the water to be treated.
[0033]
By the way, when the biological treatment by the aeration operation proceeds, the fixed bed 126 may be clogged due to an increase in the amount of solid components such as SS captured by the fixed bed 126 in the filtration region 125. There is sex. As a countermeasure, in the septic tank 101 according to the present embodiment, this is dealt with by increasing the flow rate per unit time of the air flow 155 by the air supply means 153 and increasing the flow rate of the swirl flow 159. That is, the flow rate per unit time of the downward flow in the filtration treatment region 125 is increased by circulating a swirling flow having a large capacity in the aerobic treatment tank 107 as compared with the normal aerobic treatment. The solid product trapped in the inner fixed bed 126 is removed. In the present embodiment, the air supply amount per unit time from the blower 151 is set to be approximately twice that in the aerobic process when the filtration process region 125 is cleaned.
[0034]
The washing water that has washed the filtration treatment region 125 passes through the lower region of the filtration treatment region 125, that is, the downstream side of the swirling flow 159, via the air lift pump 143 and the transfer pipe 145 for transferring the treated water, (FIG. 1) to be processed in each processing tank of the septic tank 101. Even when the filtration treatment area 125 is washed, the water to be treated flows from the treatment flow path 117 into the aerobic treatment tank 107 without being restricted, so that the water level in the aerobic treatment tank 107 is extracted by drawing out the washing water. There is no such situation as a sudden decline.
[0035]
In the present embodiment, it is possible to cope with the cleaning of the filtration treatment region 125 only by increasing the flow rate of the swirling flow 159, which contributes to further rationalization of the structure of the septic tank 101. In addition, it is possible to obtain not only the filtration treatment region 125 but also the aerobic treatment region 123 through the swirl flow 159. Further, since the washing water that has washed the filtration treatment region 125 (and the aerobic treatment region 123) is drawn out from the lower region of the filtration treatment region 123, which is the downstream region of the swirling flow 159, by the air lift pump 143 for transferring the treated water, It becomes possible to suppress as much as possible that the washing water contained in a large amount is diffused into the aerobic treatment tank 107.
[0036]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment relates to the structural change of the filtration region 125 in the first embodiment. Therefore, for the elements that are substantially equivalent to those of the first embodiment, the same reference numerals are used for the sake of convenience, and the detailed description is omitted. In the septic tank 201 according to the second embodiment, a fluidized carrier bed is employed instead of the fixed bed 126 for the filtration treatment region 125 in the aerobic treatment tank 207 (that is, in the second embodiment, A fixed bed 126 is set in the aerobic treatment area 123, while a fluid carrier bed is set in the filtration process area 125). Specifically, as shown in FIG. 3, an upper perforated plate 227 and a lower perforated plate 229 are disposed at the upper end and lower end of the filtration treatment region 125, respectively, and between the upper perforated plate 227 and the lower perforated plate 229. A large number of granular carriers 226 are filled in the space region formed to form a fluidized carrier bed. Each of the perforated plates 227 and 229 has a large number of holes appropriately set so as to allow the water to be treated to flow and restrict the flow of the carrier 226.
[0037]
An air supply means 253a connected to the blower 151 is disposed below the aerobic treatment region 123, while a second connected to the blower 151 is provided below the lower porous plate 229 in the filtration treatment region 125. The air supply means 253b is provided. The configuration of the first and second air supply units 253a and 253b is substantially the same as the air supply unit 153 in the first embodiment, and thus detailed description thereof is omitted. Further, other configurations of the second embodiment have the same contents as the configurations of the first embodiment, and thus detailed description thereof is omitted.
[0038]
When the aerobic treatment is performed in the septic tank 201 according to the second embodiment configured as described above, as shown in FIG. 3, the first air supply means arranged at the lower portion of the aerobic treatment region 123. An air flow 155 is supplied to the aerobic treatment region 123 from 253a. In the aerobic treatment tank 207, the air flow 155 forms a swirl flow 159 in which the upward flow 155 a acts on the aerobic treatment region 123 and the downward flow 155 b acts on the filtration treatment region 125. At this time, each carrier 226 in the filtration treatment region 125 is supported by the lower perforated plate 229 by receiving a flow pressure to the lower side of the filtration treatment region 125 by the downward flow 155b, thereby forming a filter bed. The solid component is captured and filtration is performed.
[0039]
According to the second embodiment, in addition to the effect of the swirling flow 159 and the effect of the aerobic treatment region 123 using the fixed bed 126 as in the first embodiment, the filtration treatment region 125 is obtained. Is constituted by a fluid type carrier bed, the substantial filtration area of the filtration treatment region 125 can be greatly improved, and the septic tank 201 having excellent filtration treatment ability can be obtained.
[0040]
On the other hand, as the filtration process progresses with the improvement of the filtration process capability, clogging may occur due to the filling carrier 226 in the filtration process region 125 supplementing a large amount of filtrate. Therefore, in the second embodiment, as shown in FIG. 4, a strong air flow 256 is periodically discharged from the second air supply unit 253 b to the filtration region 125. By this air flow 256, a strong upward flow 256b is formed in the filtration treatment region 125, and a strong downward flow 256a is generated in the aerobic treatment region 123 through the upper advection portion 133, while the lower advection portion 135 is By circulating via, a strong swirl flow 260 is formed in the aerobic treatment tank 207.
[0041]
This swirl flow 260 is washed while flowing each carrier 226 in the filtration treatment region 125 in the filtration treatment region 125 (in the space region between the upper porous plate 227 and the lower porous plate 229) by the upward flow 256b, It flows in the aerobic treatment tank 207 in the opposite direction (counterclockwise in the figure) to the swirl flow 159 during the aerobic treatment. As a result, the washing water of the carrier 226 further has a washing action on the fixed bed 126 in the aerobic treatment region 123 and passes through the lower advection section 135 and below the filtration treatment region 125, that is, downstream of the reverse swirl flow 260. It reaches an area and is returned to the upstream treatment tank through the air lift pump 143 and the transfer pipe 145 for transferring the water to be treated.
[0042]
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. The third embodiment relates to a structural change of the aerobic treatment region 123 in the first and second embodiments. Therefore, detailed description of elements substantially equivalent to those of the first and second embodiments will be omitted for convenience.
[0043]
Regarding the septic tank 301 according to the third embodiment, FIG. 5 shows a state when the aerobic treatment of the water to be treated is performed using the aerobic treatment tank 307, and FIG. The status as it is performed is shown.
[0044]
In the third embodiment, with respect to the aerobic treatment region 323 in the aerobic treatment tank 307 in the septic tank 301, a fixed bed is formed by filling a large number of carriers 326 into the aerobic treatment region 323 so as not to flow. Yes. Specifically, as shown in FIG. 5, an upper porous plate 327 and a lower porous plate 329 are disposed at the upper end portion and the lower end portion of the aerobic treatment region 323 or in the vicinity thereof, so that the upper porous portion A space region formed between the plate 327 and the lower porous plate 329 is packed densely with the granular carrier 326. As a result, the carriers 326 are brought into contact with each other, so that free flow in the water to be treated is regulated. That is, in the third embodiment, by filling a large number of granular carriers 326, the carrier 326 flows with respect to the water to be treated while greatly increasing the substantial surface area for aerobic microorganisms to adhere. It is possible to increase the generation rate of biofilm by regulating the above. Air supply means 353a and 353b are disposed below the aerobic treatment region 323 and the filtration treatment region 325, respectively.
[0045]
When performing the aerobic treatment using the septic tank 301 according to the third embodiment configured as described above, as shown in FIG. 5, the air supply means 353a disposed at the lower portion of the aerobic treatment region 323 The air flow 355 is supplied to the aerobic treatment region 323, and thereby, the swirl flow in which the upward flow 155 a acts on the aerobic treatment region 123 and the downward flow 155 b acts on the filtration treatment region 125, respectively. 159 is formed. At this time, since each carrier 326 in the aerobic treatment region 323 is in a state in which free flow with respect to the water to be treated is restricted, the carrier 326 is fixed to the upward flow 355a that rises in the aerobic treatment region 323. Perform aerobic treatment while acting like a floor. Further, in the filtration region 325, each carrier 226 is supported by the lower perforated plate 229 while being pressed downward by the downward flow 155b to form a filter bed, thereby capturing solid components in the water to be treated. The filtration process is performed.
[0046]
According to the third embodiment, unlike the structure of the aerobic treatment region 123 by the fixed bed 124 in the first and second embodiments, a large number of carriers whose flow with respect to the water to be treated is regulated are fixed. With the configuration in which the aerobic treatment region 323 is formed by filling, the substantial specific surface area of the aerobic treatment region 323 can be greatly improved, and a configuration with excellent aerobic treatment capability can be obtained.
[0047]
In the third embodiment, similarly to the second embodiment, the carrier 326 in the filtration treatment region 325 is formed with the progress of the filtration treatment over time due to the formation of the filtration treatment region 325 by the fluidized carrier bed. In addition, the problem of clogging by the filtrate may occur. Therefore, in the third embodiment, as shown in FIG. 6, a strong air flow 356 is periodically discharged from the second air supply means 353 b to the filtration processing region 325. By this air flow 356, a strong upward flow 356b is formed in the filtration treatment region 325, and the upward flow 356b generates a strong downward flow 356a in the aerobic treatment region 323 through the upper advection part 133. By circulating through the lower advection part 135, a strong swirl flow 360 is formed in the aerobic treatment tank 307.
[0048]
The swirl flow 360 is washed while the carriers 326 in the filtration treatment region 325 are caused to flow in the filtration treatment region 325 by the upward flow 356b, and is opposite to the swirl flow 359 during the aerobic treatment (see FIG. The inside of the aerobic treatment tank 307 flows in the counterclockwise direction. As a result, the washing water of the carrier 326 further has a washing action on each carrier 326 in the aerobic treatment region 323, and passes through the lower advection part 135, below the filtration treatment region 325, that is, downstream of the reverse swirl flow 360. It reaches an area, and is returned to the upstream treatment tank from there via the air lift pump 143 and the transfer pipe 145 for transferring the water to be treated. In addition, since the carrier 326 in the aerobic treatment region 323 maintains a state in which the flow is restricted even with respect to the reverse direction swirl flow 360, there is a situation in which the biofilm formed on the surface of the carrier 326 is separated more than necessary. It can be prevented beforehand.
[0049]
About each above-mentioned embodiment, various changes can be made as follows within the scope of the gist of the present invention. For example, while the aerobic treatment region 123 is packed densely while regulating the flow of the carrier, a fixed bed is formed, while the filtration treatment region 125 is formed using a plate-like fixed bed that can be fixed to the tank body. A configuration may be employed. Alternatively, the filtration treatment region 125 may be configured to form a fixed bed by densely filling the carrier while regulating the flow.
[0050]
In addition, the blower 151 according to the second and third embodiments may be configured to be arranged independently for the aerobic processing region and for the filtration processing region, respectively, or use a timer and phase control means as appropriate. Thus, a single blower may be dealt with by time control and air volume control. Moreover, you may comprise using the blower which can also drive the air lift pump 143 for to-be-processed water transfer.
[0051]
In addition, regarding the transfer of the water to be treated, in the present embodiment, the air lift pump 143 for transporting the water to be treated is pulled out and transferred both during the aeration operation and during the cleaning of the filtration treatment area. May be.
[0052]
A configuration in which treated water is returned to a treatment tank other than the contaminant removal tank 103, for example, an anaerobic filter bed tank 105, by a treatment water transfer air lift pump 143, upstream of the aerobic treatment tank 107. Can also be adopted. Moreover, the structure which abbreviate | omits the partition wall 121 in the aerobic treatment tank 107 (and 207,307) is also employable.
[0053]
Furthermore, in the said 2nd and 3rd embodiment, when the filtration process area | regions 125 and 325 were wash | cleaned, the form using a reverse swirl flow was employ | adopted, for example, the washing water in the filtration process area | regions 125 and 325 is aerobic treatment. From the viewpoint of suppressing the diffusion to the tanks 207 and 307 as much as possible, a configuration is used in which the swirling flow is not used and the washing water in the filtration treatment regions 125 and 325 is restricted from flowing out to the aerobic treatment regions 123 and 323 side. It is also possible to adopt.
[0054]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, in the septic tank which has a biological filtration processing tank, while improving the efficiency of a biological filtration process further, the construction technology of the septic tank which can further improve the energy efficiency in a septic tank was provided. .
[Brief description of the drawings]
FIG. 1 shows an overall configuration of a septic tank according to an embodiment of the present invention.
FIG. 2 shows a state during aeration operation for the biological filtration treatment tank according to the embodiment of the present invention.
FIG. 3 shows a state during aeration operation for a biological filtration treatment tank according to a second embodiment of the present invention.
FIG. 4 shows a state during washing of a filtration treatment area in a biological filtration treatment tank according to a second embodiment of the present invention.
FIG. 5 shows a state during aeration operation for a biological filtration treatment tank according to a third embodiment of the present invention.
FIG. 6 shows a state during washing of a filtration treatment area in a biological filtration treatment tank according to a third embodiment of the present invention.
[Explanation of symbols]
101 Septic tank
102 Septic tank housing
103 Debris removal tank
105 Anaerobic filter bed tank
107 biological filtration tank
109 treated water tank
111 Disinfection tank
113 Inflow part
115 Discharge pump
117 treatment channel
119 treated water
121 partition wall
123 Biological treatment area
124 fixed floor
125 Filtration area
126 Fixed floor
133 Upper advection section
135 Lower advection
141 Treated water tank advection section
143 Airlift pump for transferring treated water
145 transfer pipe
151 Blower
153 Air supply means
155 upward flow
157 Downstream
159 Swirl
226 Granular carrier
227 Upper perforated plate
229 Lower perforated plate

Claims

A septic tank having a biological filtration treatment tank in which a biological treatment region and a filtration treatment region are formed,
A partition wall that partitions the biological treatment region and the filtration treatment region, an upper advection part above the partition wall, and a lower advection part below the partition wall,
The biological treatment area, fixed bed flow in the water to be treated is regulated is formed Rutotomoni, air supply means is arranged below the biological treatment area,
In the filtration region, a fluidized bed filled with a large number of granular carriers allowed to flow in the water to be treated is formed, and a second air supply means is disposed below the fluidized bed,
Further, only the water to be treated can be transferred between the biological treatment area and the filtration treatment area through the upper advection section and the lower advection section . by air upflow from below, while the in the biological filtration treatment tank, that will be formed swirling flow to reflux into the biological treatment area with transferring treated water from the biological treatment area to the filtration area The clarification tank , wherein the carrier flows and the filtration region is washed by the upward air flow from the lower side of the fluidized bed by the second air supply means during the filtration region washing .

The septic tank according to claim 1 ,
The septic tank characterized by cleaning the said filtration process area | region by increasing the flow volume per unit time of the said swirling flow produced by the air upward flow from the said air supply means .

A method for treating sewage using a biological filtration treatment tank in which a biological treatment region and a filtration treatment region are formed,
In the biological treatment area, biologically treating the treated water using a fixed bed in which flow in the treated water is restricted,
In the filtration treatment region, the treatment water is filtered using a fluidized bed filled with a large number of granular carriers allowed to flow in the treatment water,
The swirl flow formed by the upward air flow from below the biological treatment region is processed through the upper and lower advection portions and the lower advection portion above and below the partition wall that partitions the biological treatment region and the filtration treatment region. a step of refluxing to the biological treatment area only water from the biological treatment area after transferring to the filtration area,
Washing the filtration region by flowing the carrier by upward air flow from below the fluidized bed;
A method for treating sewage, comprising: