【０００１】
【発明の属する技術分野】
本発明は、牛，馬，羊，豚等の畜類の畜糞尿、し尿、食品加工工場の廃液，焼酎製造工場の廃液等の工場廃水、生ゴミ等の生活廃水等の有機物を含む汚水を処理する汚水処理装置に関するものである。
【０００２】
【従来の技術】
従来より、有機物を含む汚水の処理方法としては種々の生物処理が行われている。なかでも、有機物分解能を有する好気性細菌群を含む泥状の微生物集塊を循環しながら連続的に汚水を処理する活性汚泥法が多く用いられている。
しかしながら、活性汚泥法は、多大な設備投資と運転経費が必要で設備負荷を要するという問題を有していた。また、汚水処理に伴って発生した余剰汚泥等の固形廃棄物を、必要に応じて減容のため焼却し、埋立等によって処分しなければならず、これらの処分に伴い周辺環境が汚染されるという問題を有していた。また、汚水処理の際に悪臭が発生するため、立地場所が限られるという問題を有していた。
そこで、近年、余剰汚泥等の固形廃棄物がほとんど発生しないとともに悪臭の発生もほとんどなく、さらに設備負荷を要さない有機物を含む汚水の処理技術が開発されている。
【０００３】
従来の技術としては、（特許文献１）に「原水槽と調整槽と１以上の曝気槽と沈殿槽とを有する汚水処理装置において、汚水処理装置の最下流位置に好気性微生物群を含んだ水が収容され原水槽と連通した管路を有する濃縮槽を備えた汚水処理装置」が開示されている。
【０００４】
（特許文献２）には、「有機物を含む排水を調整準備槽、曝気反応槽、沈殿分離槽に順次送る工程と、沈殿分離槽において沈殿分離された未分解残留物質を残留物分解槽に送る工程と、残留分解槽に送られた未分解残留物の一部を調整準備槽又は曝気反応槽に送る工程と、を備えた排水の処理方法」が開示されている。
【０００５】
【特許文献１】
特開平１１−２６２７８４号公報
【特許文献２】
特開２００２−１８４６９号公報
【０００６】
【発明が解決しようとする課題】
しかしながら上記従来の技術においては、以下のような課題を有していた。
（１）（特許文献１）及び（特許文献２）に開示の技術は、系内に嫌気性微生物群が発生し難いので、汚水中の硝酸や亜硝酸の分解能力に乏しく汚水の処理効率が低いという課題を有していた。
（２）系内に微生物群が定着する場所がなく微生物膜が生成発達し難いので、汚水の分解処理効率が低いという課題を有していた。
【０００７】
本発明は上記従来の課題を解決するもので、系内に嫌気性微生物群を発生させることができるとともに、微生物群を定着させて微生物膜を生成発達させることができるので、好気性微生物群の働きを嫌気性微生物群が補って有機物の分解効率を高め処理効率に優れる汚水処理装置を提供することを目的とする。
【０００８】
【課題を解決するための手段】
上記従来の課題を解決するために本発明の汚水処理装置は、以下の構成を有している。
【０００９】
本発明の請求項１に記載の汚水処理装置は、好気性微生物群等の汚物を分解する分解性微生物群が分散された汚水が貯留され処理される１乃至複数の曝気槽と、（ａ）前記曝気槽に配設され通水性を有する多孔質体保持部と、前記多孔質体保持部に収容された多孔質体と、及び／又は、（ｂ）前記曝気槽の内壁面に形設された若しくは前記曝気槽に配設された凹凸部と、を備えた構成を有している。
この構成により、以下のような作用が得られる。
（１）曝気槽が多孔質体や凹凸部を備えているので、多孔質体の細孔内や多孔質体間、凹凸部の凹部内等の溶存酸素が少ない部分に嫌気性微生物群を定着させることができる。この結果、汚水に混合された好気性微生物群が汚水中の有機物を摂取して酸化し水，炭酸ガス，アンモニア等に無機化し分解処理し、嫌気性微生物群が汚水中の有機物を酸化若しくは還元して有機酸，炭酸ガス等を生成し、また汚水中の硝酸や亜硝酸を還元して窒素ガスを生成するとともに有機物を酸化分解することができる。これにより、好気性微生物群の働きを嫌気性微生物群が補って汚水の分解処理効率を高めることができる。
（２）多孔質体の表面や凹凸部に微生物膜が生成発達するので、曝気槽内の酸素と汚水中の有機物が微生物膜内に取り込まれることによって有機物が分解され、汚水の分解処理効率を高めることができる。
【００１０】
ここで、汚水としては、牛，馬，羊，豚，鶏等の畜類の畜糞尿、し尿、食品加工工場の廃液，焼酎製造工場の廃液等の工場排水、生ゴミや米のとぎ汁等の生活排水、養魚場，河川，湖沼等の水等の有機物の汚物を含むものが用いられる。なお、粗大な生ゴミ等は破砕等して微細化して水に懸濁させておくのが好ましい。分解処理効率を高めるためである。
【００１１】
多孔質体保持部としては、金属製や合成樹脂製等で形成された網，ガーゼ，織布，不織布，浸透膜，複数の開口部が穿設された金属製や合成樹脂製等の板状体等でカゴ状，袋状，箱状等に形成された通水性を有するものが用いられ、内部に多孔質体が収容される。
多孔質体が収容された多孔質体保持部は、曝気槽の所定箇所に配設され少なくとも一部が汚水に浸漬される。
【００１２】
多孔質体としては、木炭，竹炭，活性炭等の炭材、パーライト，バーミキュライト，ゼオライト，泡ガラス等の表面に開口する凹凸や微細孔が形成されたものが用いられる。特に、炭材が好適である。表面に無数の微細孔を有し微生物群が定着しやすいからである。
多孔質体は、平均粒径が２〜５０ｍｍの粒状や片状等に形成されたものを用いるのが好ましい。多孔質体の表面積を大きくして汚水と接触する細孔の数を増やすとともに微生物膜が生成発達できる面積を広げることができるからである。また、多孔質体同士の接触点が増え嫌気性微生物群の発生数を増やすことができるからである。
多孔質体の平均粒径が２ｍｍより小さくなるにつれ多孔質体の細孔が破壊されるものが多く発生し嫌気性微生物群が発生し難くなる傾向がみられ、平均粒径が５０ｍｍより大きくなるにつれ多孔質体の表面積が小さくなり汚水と接触する細孔の数や多孔質体同士の接触点が少なくなり嫌気性微生物群が発生し難くなる傾向がみられるため、いずれも好ましくない。
なお、多孔質体保持部の網目や開口部は、収容された多孔質体が流出しないような大きさに形成される。また、多孔質体保持部は、必要に応じて完全に包み込んだり蓋部等を設けることができる。比重の小さな多孔質体を用いた場合でも、浮上して分散しないようにするためである。
【００１３】
凹凸部としては、曝気槽の内壁面がコンクリート製等で形設された場合の微細な凹凸を有する素地、曝気槽の内壁面が金属製等の板材等で形成された場合の溶射皮膜やブラスト等で形設された粗面、金属製や合成樹脂製等で形成され曝気槽内に配設されたメッシュや網状体等が用いられる。
凹凸部の表面粗さとしては、ＪＩＳ Ｂ０６０１−１９９４で規定される最大高さで０．１〜５ｍｍが好適に用いられる。最大高さが０．１ｍｍより小さくなるにつれ凹凸が小さく嫌気性微生物群が発生し難くなる傾向がみられ、５ｍｍより大きくなるにつれ凹凸部の表面積が小さくなり嫌気性微生物群が発生し難くなるとともに流され易く定着し難くなる傾向がみられるため、いずれも好ましくない。
【００１４】
曝気槽内の汚水には、好気性微生物群や嫌気性微生物群の分解性微生物群に加え、タンパク質や脂質等を分解する酵素群を添加し分散させることもできる。これにより、汚水に含まれるタンパク質や油脂等の分解を促し汚水の分解処理効率を高めることができる。
【００１５】
分解性微生物群としては、好気性や嫌気性の細菌，カビ菌，原生動物等の微生物群が用いられる。特に、豚等の家畜の糞尿を酸素の存在下で粘度質土壌や暗室のコンクリート等内で貯留し一定期間にわたって水分を蒸発させつつ熟成及び濃縮させたものが好適に用いられる。
豚等の家畜の糞尿に含まれる腸内細菌群を利用した分解性微生物群を用いることにより、以下のような作用が得られる。
（１）家畜の腸内細菌群を含んだ糞尿を熟成・濃縮させることにより酵素群が生成される。分解性微生物群が酵素群を含有しているので、汚水中の有機物がほぼ完全に分解され余剰汚泥等の固形廃棄物量をほぼゼロにすることができる。理由は不明であるが、酵素群が有機物の細胞壁を破壊する際の触媒として作用しているとともに、細胞壁の破壊された有機物を栄養にして炭酸ガス，水，窒素ガス等に分解していると推察している。
（２）有機物の分解時間が早く悪臭も発生し難い。理由は不明であるが、有機物の分解が酵素群による触媒反応であり反応時間が短いためであると推察している。
（３）系内への汚水の供給量よりも汚水が処理されて生成された処理水の発生量が少なくなるので、処理水を汚水の希釈水として循環利用することにより系外へ処理水を排出せず、河川等の周辺環境を汚染することがない。理由は不明であるが、酵素群が有機物を分解する際に大量の水を消費するからであり、酵素群は水を水素ガスと酸素ガスに分解していると推察している。
【００１６】
分析の結果、家畜の糞尿に含まれる腸内細菌群としては、無芽胞グラム陽性桿菌類（Ｇｒｏｕｐ２０）、グラム陽性桿菌類（コリネ型細菌群、ｃｏｒｙｎｅｆｏｒｍ ｂａｃｔｅｒｉａ）、グラム陽性球菌類（スタネ型細菌群、Ｓｔａｐｎｅｆｏｒｍ ｂａｃｔｅｒｉａ）、シュードモナスアエルギノーサ（緑膿菌、Ｐｓｅｕｄｏｍｏｎａｓａｅｒｕｇｉｎｏｓａ）、シュードモナススツッゼリー（Ｐｓｅｕｄｏｍｏｎａｓ Ｓｔｕｔｚｅｒｉ）、セラチアリクエファシエンス（Ｓｅｒｒａｔｉａ Ｌｉｇｕｅｆａｃｉｅｎｓ）、セラチアマルセッセンス（Ｓｅｒｒａｔｉａｍａｒｃｅｓｃｅｎｓ）、ステノトロホモナスマルトフィーラ（Ｓｔｅｎｏｔｒｏｐｈｏｍｏｎａｓｍａｌｔｏｐｈｉｌｉａ）、バチルススヘリカス（Ｂａｃｉｌｌｕｓｓｐｈａｅｒｉｃｕｓ）を含有していることが確認された。
豚等の家畜の糞尿に含まれる腸内細菌群を利用した分解性微生物群としては、例えば、矢部菌群（商品名：アースラブ、アースラブ・ニッポン社製）を用いることができる。
【００１７】
なお、曝気槽内の汚水の溶存酸素量を、汚水のＢＯＤ値に応じて６〜１０ｐｐｍになるように調整すると、曝気のためのエネルギー消費が少なく、かつ、好気性微生物群の活性を高めることができ分解処理効率を高めることができ好ましい。溶存酸素量が６ｐｐｍより少なくなるにつれ好気性微生物群の活性が低下する傾向がみられ、１０ｐｐｍより多くなるにつれ曝気のためのエネルギー消費量が増加する傾向が見られるため好ましくない。
【００１８】
請求項２に記載の発明は、請求項１に記載の汚水処理装置であって、（ａ）前記曝気槽が、所定部に貫通孔が形成された仕切板で区画され、前記多孔質体保持部が、前記貫通孔に配設されている、及び／又は、（ｂ）前記曝気槽が、１乃至複数の前記多孔質体保持部で区画されている構成を有している。
この構成により、請求項１で得られる作用に加え、以下のような作用が得られる。
（１）曝気槽を区画する仕切板の貫通孔に通水性を有する多孔質体保持部が配設され、及び／又は、曝気槽が多孔質体保持部で区画されているので、曝気槽内の汚水が多孔質体に接触し易く、汚水に混合された好気性微生物群による有機物の分解処理に加え、多孔質体に生成発達した微生物膜や嫌気性微生物群によって汚水を処理することができ、汚水の処理効率を高めることができる。
（２）曝気槽内の汚水が多孔質体保持部に収容された多孔質体を通過する際に、浮遊物質等が多孔質体に捕捉され易く、浮遊物質等の分解を促進することができる。
【００１９】
ここで、汚水は、複数に区画された曝気槽の一端側の上流部へ供給するのが望ましい。汚水処理装置は閉じたシステムで用いられるので、汚水が供給された曝気槽の上流部の水位が上昇することにより曝気槽内の水位を平均化するように自然な水流が形成されるため、曝気槽内に水流を形成する手段を配設する必要がなく設備負荷を要さず、さらに多孔質体保持部に収容された多孔質体を汚水が通過する際に浮遊物質等が多孔質体に捕捉され易くなるからである。
【００２０】
請求項３に記載の発明は、請求項１又は２に記載の汚水処理装置であって、前記曝気槽を複数有し、複数の前記曝気槽が、前記曝気槽の上方で連通された曝気槽連通部を備えた構成を有している。
この構成により、請求項１又は２で得られる作用に加え、以下のような作用が得られる。
（１）複数の曝気槽が上方で連通された曝気槽連通部を備えているので、汚水が処理されて生成した上澄液を下流側の曝気槽に送って、そこで上澄液をさらに曝気処理することができ処理効率に優れる。
【００２１】
本発明の請求項４に記載の発明は、請求項１乃至３の内いずれか１に記載の汚水処理装置であって、前記曝気槽の上流部の上方に配設され浮遊物質を含有する汚水を収集する浮遊物質収集部と、前記浮遊物質収集部で収集された前記汚水が貯留され分解処理される濃縮分解槽と、を備えた構成を有している。
この構成により、請求項１乃至３の内いずれか１で得られる作用に加え、以下のような作用が得られる。
（１）曝気槽の上流部の上方に配設された浮遊物質収集部と、収集された浮遊物質を含有する汚水が貯留され分解処理される濃縮分解槽と、を備えているので、分解処理に時間を要する浮遊物質を濃縮分解槽に集め、曝気槽とは別の系統で分解性微生物群等によって時間をかけて処理することができ曝気槽の処理効率を高めることができる。
（２）濃縮分解槽を備えているので、分解処理に時間のかかる浮遊物質を多量に含有した汚水をある程度分解した後に曝気槽に導入することができ、曝気槽内の分解性微生物群に過剰な負荷を与えることなく汚水処理を行うことができる。また、曝気槽内の分解性微生物群の濃度を必要以上に高めることなく汚水の処理を行うことができ、運転経費を低く抑えることができる。
（３）浮遊物質を大量に含む汚水だけを濃縮分解槽内の分解性微生物群等で分解するので、分解性微生物群の濃度は濃縮分解槽内だけを高めればよく、また濃縮分解槽内の高濃度の汚水を餌にして分解性微生物群を増殖させることができるので、コストの高い分解性微生物群が必要最小限の量ですみ運転経費を低く抑えることができる。
【００２２】
ここで、濃縮分解槽としては、エアレーション装置が配設されたものが用いられる。汚水に混合された好気性微生物群の働きを活発にするとともに濃縮分解槽内での汚水の嫌気性腐敗を防止するためである。
【００２３】
浮遊物質収集部には、濃縮分解槽に連通する分解槽連通部を接続し、分解槽連通部には圧送ポンプ等の搬送手段を配設するのが好ましい。浮遊物質収集部で収集された浮遊物質を含有する汚水を、搬送手段を用い分解槽連通部を通して濃縮分解槽に供給することができるからである。なお、分解槽連通部や搬送手段を配設することなく、浮遊物質収集部で収集した汚水を濃縮分解槽に人力等で搬送し供給することもできる。
【００２４】
本発明の請求項５に記載の発明は、請求項１乃至４の内いずれか１に記載の汚水処理装置であって、前記曝気槽で前記汚水が処理された処理水を前記曝気槽の上流部に還流する処理水還流部を備えた構成を有している。
この構成により、請求項１乃至４の内いずれか１で得られる作用に加え、以下のような作用が得られる。
（１）処理水還流部を備え、高濃度の汚水を処理水で希釈することができるので、分解性微生物群に過剰な負荷を与えることなく汚水処理を行うことができる。
（２）処理水は分解性微生物群を含有しているので、これを繰り返し利用することで曝気槽内の分解性微生物群の濃度を必要以上に高めることなく汚水の処理を行うことができ、運転経費を低く抑えることができる。
（３）処理水還流部を用いて処理水を曝気槽の上流部に還流することで曝気槽の上流部の水位が上昇するので、曝気槽内の水位を平均化するように自然な水流が形成されるため、曝気槽内に水流を形成する手段を配設する必要がなく設備負荷を軽減することができる。
【００２５】
【発明の実施の形態】
以下、本発明の一実施の形態を、図面を参照しながら説明する。
（実施の形態１）
図１は、本発明の実施の形態１における汚水処理装置の要部平面模式図であり、図２は図１のＡ−Ａ線における要部断面模式図であり、図３は図１のＢ−Ｂ線における要部断面模式図である。
図１において、１は実施の形態１における汚水処理装置、２は牛，馬，羊，豚，鶏等の畜類の畜糞尿、し尿、食品加工工場の廃液，焼酎製造工場の廃液等の工場排水、生ゴミや米のとぎ汁等の生活排水等の有機物の汚物を含む汚水が貯留される汚水貯留槽、３は汚水貯留槽２に連設された曝気槽としての第１曝気槽、３ａ，３ｂは第１曝気槽３の内部を３槽に区画した仕切板、４ａ，４ｂは仕切板３ａ，３ｂの所定部に形成された貫通孔に通水性を有する金網等で箱状等に形成され配設された多孔質体保持部、５ａ，５ｂは平均粒径が２〜５０ｍｍの粒状等に形成され多孔質体保持部４ａ，４ｂに各々収容された木炭や竹炭等の多孔質体、６は仕切板３ａ，多孔質体保持部４ａで区画された第１曝気槽３の上流部として汚水の濃度を希釈調整する第１上流調整曝気槽、７は仕切板３ａ，多孔質体保持部４ａと仕切板３ｂ，多孔質体保持部４ｂで区画された第１曝気槽３の第１中流曝気槽、８は仕切板３ｂ，多孔質体保持部４ｂで区画された第１曝気槽３の第１下流曝気槽、９は第１曝気槽３の一部に連設され連通された曝気槽としての第２曝気槽、９ａは第２曝気槽９の内部を２槽に区画した仕切板、９ｂは仕切板９ａの所定部に形成された貫通孔に通水性を有する金網等で箱状等に形成され配設された多孔質体保持部、９ｃは平均粒径が２〜５０ｍｍの粒状等に形成され多孔質体保持部９ｂに収容された木炭や竹炭等の多孔質体、１０は仕切板９ａ，多孔質体保持部９ｂで区画された第２曝気槽９の第２上流曝気槽、１１は仕切板９ａ，多孔質体保持部９ｂで区画された第２曝気槽９の第２下流曝気槽、１２は第２曝気槽９の第２下流曝気槽１１と連通され第１曝気槽の第１上流調整曝気槽６に連設された処理水槽、１３は処理水槽１２と汚水貯留槽２に連設された濃縮分解槽、１４は汚水貯留槽２の下部と第１上流調整曝気槽６とを連通した管体からなる貯留槽連通部、１４ａは貯留槽連通部１４に配設され汚水貯留槽２内に貯留された高濃度の汚水を第１上流調整曝気槽６内に圧送し定量供給するポンプ、１５は処理水槽１２と第１曝気槽３の上流部である第１上流調整曝気槽６とを連通した管体からなる処理水還流部、１５ａは処理水還流部１５に配設され処理水槽１２内の処理水を第１上流調整曝気槽６に必要に応じて圧送するポンプ、１５ｂは第２曝気槽９の下流部である第２下流曝気槽１１の下部と第１曝気槽３の上流部である第１上流調整曝気槽６の上部とを連通する管体からなる曝気槽還流部、１５ｃは曝気槽還流部１５ｂに配設され第２下流曝気槽１１の汚水を第１上流調整曝気槽６に圧送するポンプ、１６は第１曝気槽３の上流部の第１上流調整曝気槽６と濃縮分解槽１３とを連通する管体からなる分解槽連通部、１６ａは分解槽連通部１６の端部の第１上流調整曝気槽６内の上方に配設され浮遊物質を含有する汚水を収集する漏斗状等に形成された浮遊物質収集部、１６ｂは分解槽連通部１６に配設され第１上流調整曝気槽６内の汚水を濃縮分解槽１３に圧送するポンプである。
ここで、本実施の形態においては、汚水貯留槽２の少なくとも下部と濃縮分解槽１３との間は、図示しない開閉弁が配設され開閉可能に形成された１乃至複数の連通孔で連通されている。なお、以下の説明においては開閉弁が閉止され汚水貯留槽２と濃縮分解槽１３とが完全に仕切られている場合について説明する。
【００２６】
図２において、１７ａ，１７ｂ，１７ｃ，１７ｄは汚水貯留槽２，第１上流調整曝気槽６，第１中流曝気槽７，第１下流曝気槽８の底部に各々配設され酸素を含有する気体を噴出し各槽内のエアレーションを行う散気管、１８は散気管１７ａ，１７ｂ，１７ｃ，１７ｄに接続した散気配管、１９は散気配管１８に接続し気体を圧送するエアポンプ等のコンプレッサである。
図３において、２０は第１曝気槽３の第１下流曝気槽８と第２曝気槽９の第２上流曝気槽１０とが各々の上方の汚水の水面近傍で連通された曝気槽連通部、２１は第２下流曝気槽１１と処理水槽１２とが各々の上方の水面近傍で連通された処理水槽連通部、２２ａ，２２ｂ，２２ｃ，２２ｄは濃縮分解槽１３，処理水槽１２，第２下流曝気槽１１，第２上流曝気槽１０の底部に各々配設され酸素を含有する気体を噴出し各槽内のエアレーションを行う散気管、２３は散気管２２ａ，２２ｂ，２２ｃ，２２ｄに接続し他端がコンプレッサ１９に接続した散気配管である。
【００２７】
以上のように構成された実施の形態１における汚水処理装置ついて、以下その使用方法を説明する。
始めに、第１曝気槽３、第２曝気槽９、処理水槽１２、濃縮分解槽１３に所定量の水を貯留するとともに、第１曝気槽３、第２曝気槽９、処理水槽１２、濃縮分解槽１３に所定量の矢部菌群（商品名：アースラブ、アースラブ・ニッポン社製）等の好気性及び嫌気性の細菌，カビ菌，原生動物等の微生物群である分解性微生物群を混合し分散する。次いで、コンプレッサ１９を駆動して散気管１７ｂ，１７ｃ，１７ｄ，２２ａ，２２ｂ，２２ｃ，２２ｄから酸素を含有する気体を噴出させ第１曝気槽３の第１上流調整曝気槽６，第１中流曝気槽７，第１下流曝気槽８、第２曝気槽９の第２上流曝気槽１０，第２下流曝気槽、処理水槽１２、濃縮分解槽１３のエアレーションを行う。汚水貯留槽２内には畜糞尿、し尿、工場廃水、生活廃水等の有機物を含む汚水を貯留しておく。汚水貯留槽２も散気管１７ａを用いてエアレーションを行うことができる。
次いで、ポンプ１４ａを駆動して汚水貯留槽２に貯留された汚水の所定量を貯留槽連通部１４から第１上流調整曝気槽６へ供給し、高濃度の汚水を第１上流調整曝気槽６内の水で希釈する。ポンプ１４ａの駆動によって第１上流調整曝気槽６へ定量供給する汚水の供給量は、汚水のＢＯＤ値に応じて調節する。第１上流調整曝気槽６内の分解性微生物群に過度の負担をかけないようにするためである。第１上流調整曝気槽６に供給された汚水は、第１上流調整曝気槽６内の分解性微生物群によって分解される。第１上流調整曝気槽６の上方の浮遊物質を含む高濃度の汚水は、ポンプ１６ｂを駆動することによって浮遊物質収集部１６ａで収集され分解槽連通部１６を通って濃縮分解槽１３に搬送される。濃縮分解槽１３に搬送された浮遊物質を含む高濃度の汚水は、濃縮分解槽１３内の分解性微生物群によって分解される。濃縮分解槽１３内で時間をかけて分解された汚水及び濃縮分解槽１３内で増殖した分解性微生物群は、図示しないポンプ等によって第１上流調整曝気槽６に供給され継続して分解処理が行われる。
【００２８】
第１上流調整曝気槽６内に汚水が供給されることによって第１上流調整曝気槽６内の水位が上昇するので、第１上流調整曝気槽６内の汚水は、第１曝気槽３内の水位が一定になるように多孔質体保持部４ａに収容された多孔質体５ａを通過して第１中流曝気槽７内に入り、第１中流曝気槽７内の分解性微生物群及び多孔質体５ａ内に発生した嫌気性微生物群によって分解処理される。第１中流曝気槽７内の汚水は、次いで、多孔質体保持部４ｂに収容された多孔質体５ｂを通過して第１下流曝気槽８内に入り、第１下流曝気槽８内の分解性微生物群及び多孔質体５ｂ内に発生した嫌気性微生物群によって分解処理される。
第１下流曝気槽８内で分解された汚水の上澄液は、曝気槽連通部２０を通過して第２上流曝気槽１０内に入る。第２上流曝気槽１０内の汚水は、次いで、多孔質体保持部９ｂに収容された多孔質体９ｃを通過して第２下流曝気槽１１内に入り第２下流曝気槽１１内の好気性微生物群及び多孔質体９ｃ内に発生した嫌気性微生物群によって分解処理される。第２下流曝気槽１１に達した汚水は、ポンプ１５ｃを駆動することにより第２下流曝気槽１１の下部に連通する曝気槽還流部１５ｂを通って第１上流調整曝気槽６内へ供給され、繰り返し第１曝気槽３と第２曝気槽９で分解処理される。第２下流曝気槽１１内で分解された汚水の上澄液（処理水）は、処理水槽連通部２１を通過して処理水槽１２内に入る。以上のようにして、第１上流調整曝気槽６内で希釈された汚水が第１中流曝気槽７、第１下流曝気槽８、第２上流曝気槽１０、第２下流曝気槽１１と通過していくにつれて、汚水中の有機物が分解性微生物群によって分解され処理水となる。
処理水槽１２内に入った処理水は、ポンプ１５ａを駆動することにより処理水還流部１５から第１上流調整曝気槽６へ供給され、第１上流調整曝気槽６内の汚水を希釈する。
【００２９】
以上のように、実施の形態１における汚水処理装置は構成されているので、以下のような作用が得られる。
（１）第１曝気槽及び第２曝気槽に配設され通水性を有する多孔質体保持部と、多孔質体保持部に収容された多孔質体と、を備えているので、多孔質体の細孔内や多孔質体間等の溶存酸素量の少ない部分に嫌気性微生物群を発生させることができる。この結果、汚水に混合された好気性微生物群が汚水中の有機物を摂取して酸化し水，炭酸ガス，アンモニア等に無機化し分解処理し、嫌気性微生物群が汚水中の有機物を酸化若しくは還元して有機酸，炭酸ガス等を生成し、また汚水中の硝酸や亜硝酸を還元して窒素ガスを生成するとともに有機物を酸化分解することができる。これにより、好気性微生物群の働きを嫌気性微生物群が補って汚水の分解処理効率を高めることができる。
（２）多孔質体の表面に微生物膜が生成発達するので、曝気槽内の酸素と汚水中の有機物が微生物膜内に取り込まれることによって有機物が分解され、汚水の分解処理効率を高めることができる。
（３）第１曝気槽や第２曝気槽を区画する仕切板に通水性を有する多孔質体保持部が形成されているので、曝気槽内の汚水が多孔質体に接触し易く、汚水に混合された好気性微生物群による有機物の分解処理に加え、多孔質体に生成発達した微生物膜や嫌気性微生物群によって汚水を処理することができ、汚水の処理効率を高めることができる。
（４）第１曝気槽や第２曝気槽内の汚水が多孔質体保持部に収容された多孔質体を通過する際に、浮遊物質等が多孔質体に捕捉され易く、浮遊物質等の分解を促進することができる。
（５）第１曝気槽と第２曝気槽が上方で連通された曝気槽連通部を備えているので、汚水が処理されて生成した上澄液を下流側の曝気槽に送って、そこで上澄液をさらに曝気処理することができ処理効率に優れる。
（６）第１曝気槽の上流部の第１上流調整曝気槽の上方に配設された浮遊物質収集部と、収集された浮遊物質を含有する汚水が貯留され分解処理される濃縮分解槽と、を備えているので、分解処理に時間を要する浮遊物質を濃縮分解槽に集め、曝気槽とは別の系統で時間をかけて処理することができ曝気槽の処理効率を高めることができる。
（７）濃縮分解槽を備えているので、分解処理に時間のかかる浮遊物質を多量に含有した汚水をある程度分解した後に曝気槽に導入することができ、曝気槽内の好気性微生物群等に過剰な負荷を与えることなく汚水処理を行うことができる。また、曝気槽内の好気性微生物群の濃度を必要以上に高めることなく汚水の処理を行うことができ、運転経費を低く抑えることができる。
（８）浮遊物質を大量に含む汚水だけを濃縮分解槽内の好気性微生物群等で分解するので、好気性微生物群の濃度は濃縮分解槽内だけを高めればよく、また好気性微生物群を濃縮分解槽内で増殖することができ、コストの高い好気性微生物群が必要最小限の量ですみ運転経費を低く抑えることができる。
（９）処理水還流部を備え、高濃度の汚水を処理水で希釈することができるので、分解性微生物群に過剰な負荷を与えることなく汚水処理を行うことができる。
（１０）処理水は分解性微生物群を含有しているので、処理水還流部で処理水を第１上流調整曝気槽に還流して、閉じたシステムの中でこれを繰り返し循環利用することで曝気槽内の分解性微生物群の濃度を必要以上に高めることなく汚水の処理を行うことができ、運転経費を低く抑えることができる。
（１１）処理水還流部を用いて処理水を曝気槽の上流部に還流することで曝気槽の上流部の水位が上昇するので、曝気槽内の水位を平均化するように自然な水流が形成されるため、曝気槽内に水流を形成する手段を配設する必要がなく設備負荷を軽減することができる。
（１２）多孔質体の平均粒径が２〜５０ｍｍの粒状や片状に形成されているので、多孔質体の表面積を大きくして汚水と接触する細孔の数を増やすとともに微生物膜が生成発達できる面積を広げることができ、さらに多孔質体同士の接触点が増え嫌気性微生物群の発生数を増やすことができる。これにより、汚水の処理効率を高めることができる。
（１３）汚水貯留槽にエアレーションを行う散気管が配設されているので、汚水貯留槽内の汚水が嫌気性腐敗をおこすのを防止することができる。
（１４）汚水貯留槽に貯留された汚水がポンプで第１上流調整曝気槽に定量供給されるので、第１上流調整曝気槽内の水位が上昇し、これにより汚水を第１中流曝気槽、第１下流曝気槽内に順次移動させる自然な水流を形成することができ、処理効率を高めることができる。また、高濃度の汚水が第１上流調整曝気槽にポンプで定量供給されて第１上流調整曝気槽内の水で希釈されるので、第１上流曝気槽内の好気性微生物群に過度の負荷を与えず処理効率を高めることができる。
（１５）汚水貯留槽と濃縮分解槽との間が開閉可能に形成された連通孔で連通されているので、汚水貯留槽を使用せずに汚水発生源等からそのまま第１上流調整曝気槽に汚水を供給する場合は、汚水貯留槽と濃縮分解槽とを連通させて全体を濃縮分解槽として用い濃縮分解槽の容積を大きくすることができ自在性に優れる。
（１６）第２下流曝気槽の下部と第１上流調整曝気槽とを連通する曝気槽還流部を備えているので、第２下流曝気槽に達した汚水を第１上流調整曝気槽内へ供給して、閉じたシステムの中で循環させて第１曝気槽と第２曝気槽で分解処理することができ、処理能力を高めることができる。
（１７）曝気槽還流部を備えているので、第１曝気槽から第２曝気槽へ向かう水流を形成することができ、多孔質体保持部に収容された多孔質体に汚水を通過させて汚水の分解を促進させることができる。
【００３０】
なお、仕切板によって第１曝気槽３が３槽に区画され、第２曝気槽９が２槽に区画された場合について説明したが、汚水処理装置の大きさや汚水の種類によっては、各曝気槽の区画数をさらに多くしたり少なくしたりできる。また、汚水処理装置内に第１曝気槽３，第２曝気槽９の２槽が形成された場合について説明したが、汚水処理装置の大きさや汚水の種類によっては、１槽の曝気槽だけもよく、３槽以上を形成することもできる。
また、濃縮分解槽１３で浮遊物質を含む高濃度の汚水を分解処理した後、その分解物を汚水貯留槽２又は第１上流調整曝気槽６へ搬送するために、濃縮分解槽１３と汚水貯留槽２を連通する管体からなる連通部や、濃縮分解槽１３と第１上流調整曝気槽６を連通する管体からなる連通部を配設し、ポンプ等の搬送手段を用いて各連通部を通して搬送可能にすることもできる。これにより、人力等で処理物を搬送する必要がなく作業性に優れる。
また、仕切板３ａ，３ｂ，９ａの代わりに多孔質体保持部４ａ，４ｂ，９ｂで曝気槽内を区画することもできる。この場合も同様の作用が得られる。
また、第１曝気槽３，第２曝気槽９の内壁面をコンクリート製等で形成したり、第１曝気槽３や第２曝気槽９内にメッシュ等を配設して、ＪＩＳ Ｂ０６０１−１９９４で規定される表面粗さが最大高さで０．１〜５ｍｍの凹凸部を形設したり配設する場合もある。この場合も、凹凸部に好気性微生物群や嫌気性微生物群等を定着させることができ分解処理効率を高めることができる。
また、汚水を貯留する汚水貯留槽２を備えた場合について説明したが、汚水貯留槽を配設せずに汚水発生源等からそのまま第１上流調整曝気槽内に汚水を定量供給する場合もある。この場合も同様の作用が得られる。
また、処理水槽１２にポンプが配設された排水路を設けて、処理水槽１２内の処理水を系外に排出することもできる。これにより、処理水の水位が上昇した場合に、処理水を河川や浄水処理場等に放流したり養豚場や鶏舎等の畜舎の洗浄水等として用いることができる。なお、処理水は有機物が分解されているとともに分解性微生物群を含有しているので、河川や浄水処理場等に放流しても周辺環境に負担を与えない。
【００３１】
【実施例】
以下、本発明を実施例により具体的に説明する。なお、本発明はこれらの実施例に限定されるものではない。
（実施例１）
実施の形態１で説明した汚水処理装置を用いて汚水の分解処理を行った。汚水処理装置の各槽の容積は、汚水貯留槽０．８４ｍ３、第１上流調整曝気槽１．１７ｍ３、第１中流曝気槽１．３８ｍ３、第１下流曝気槽１．１７ｍ３、第２上流曝気槽１．１７ｍ３、第２下流曝気槽１．３８ｍ３、処理水槽１．１７ｍ３、濃縮分解槽０．８４ｍ３であった。多孔質体保持部は、幅０．７ｍ、厚み０．２４ｍ、高さ０．９ｍの箱状に金網を用いて形成し、各多孔質体保持部に平均粒径３ｍｍの粒状の多孔質体としての木炭を各々０．１５ｍ３収容した。
以上のような汚水処理装置の第１上流調整曝気槽、第１中流曝気槽、第１下流曝気槽、第２上流曝気槽、第２下流曝気槽、処理水槽の全体に６ｍ３の水と、分解性微生物群としての液状の矢部菌群（商品名：アースラブ、アースラブ・ジャパン社製）３００ｋｇを入れた。次いで、第１上流調整曝気槽、第１中流曝気槽、第１下流曝気槽、第２上流曝気槽、第２下流曝気槽内の水の溶存酸素量が６〜１０ｐｐｍになるように各槽の底部に配設された散気管から空気を各槽に供給した。次に、汚水としての豚の糞尿０．１ｍ３を汚水貯留槽に貯留した後、ポンプを駆動して４Ｌ／分の流量で汚水を汚水貯留槽から第１上流調整曝気槽内へ定量供給し、汚水の処理を開始した。２４時間後、処理水槽内の処理水を採取しＢＯＤの測定を行った。なお、ＢＯＤの測定は、ＪＩＳ Ｋ０１０２ ２１及び３２．３に基づいた。処理前の汚水（豚の糞尿を水で６０倍に希釈したもの）のＢＯＤは８００ｍｇ／Ｌであった。
【００３２】
処理水槽の上部から採取した処理水（２４時間処理したもの）のＢＯＤは１７０ｍｇ／Ｌであった。また、処理水は臭いが全くしなかった。２４時間後のＢＯＤの低下量からすると、４８時間後にはＢＯＤが２０ｍｇ／Ｌ程度になると予想された。
本実施例によれば、２４時間という短時間で処理水のＢＯＤを著しく低下させ、臭いも除去できる汚水処理が可能であることが明らかになった。
さらに、汚水中の有機物をほぼ完全に分解し余剰汚泥等の固形廃棄物量をほぼゼロにすることができることが明らかになった。これは、分解性微生物群として用いた矢部菌が家畜の腸内細菌群を含んだ糞尿を熟成・濃縮させて生成された酵素群を含有しているので、酵素群が有機物の細胞壁を破壊する際の触媒として作用しているとともに、細胞壁の破壊された有機物を栄養にして炭酸ガス，水，窒素ガス等に分解していると推察している。
また、２４時間曝気処理後の汚水処理装置内の汚水及び水の水位は、処理前の汚水及び水の水位よりも低くなった。これにより、処理水を汚水の希釈水として循環利用することにより系外へ処理水を排出せず、河川等の周辺環境の汚染を防止できることが明らかになった。これは、矢部菌が含有する酵素群が有機物を分解する際に大量の水を消費するからであり、酵素群は水を水素ガスと酸素ガスに分解していると推察している。
【００３３】
（比較例１）
実施例１で用いた汚水処理装置に配設された多孔質体保持部を多孔質体とともに除去し、第１上流調整曝気槽，第１中流曝気槽，第１下流曝気槽、第２上流曝気槽，第２下流曝気槽を多孔質体を介さずに連通し、比較例１の汚水処理装置を作成した。
この比較例１の汚水処理装置を用いて実施例１と同様の条件で汚水処理を行い、汚水を投入してから２４時間後、処理水槽の上部から処理水を採取しＢＯＤの測定を行った。
この結果、測定されたＢＯＤは２３０ｍｇ／Ｌであり、実施例１の汚水処理装置で処理された処理水のＢＯＤと比較すると約３０％程度大きくなっていた。
以上のように本実施例によれば、系内に多孔質体を備えているので、嫌気性微生物群を発生させることができるとともに、微生物群を定着させて微生物膜を生成発達させることができるので、好気性微生物群の働きを嫌気性微生物群が補って有機物の分解効率を高め処理効率に優れていることが明らかになった。
【００３４】
【発明の効果】
以上のように、本発明の汚水処理装置によれば、以下のような有利な効果が得られる。
請求項１に記載の発明によれば、
（１）曝気槽が多孔質体や凹凸部を備えているので、多孔質体の細孔内や多孔質体間、凹凸部の凹部内等に嫌気性微生物群を発生させることができる。この結果、汚水に混合された好気性微生物群が汚水中の有機物を摂取して酸化し水，炭酸ガス，アンモニア等に無機化し分解処理し、嫌気性微生物群が汚水中の有機物を酸化若しくは還元して有機酸，炭酸ガス等を生成し、また汚水中の硝酸や亜硝酸を還元して窒素ガスを生成するとともに有機物を酸化分解することができる。これにより、好気性微生物群の働きを嫌気性微生物群が補って汚水の分解処理効率の高い汚水処理装置を提供することができる。
（２）多孔質体の表面や凹凸部に微生物膜が生成発達するので、曝気槽内の酸素と汚水中の有機物が微生物膜内に取り込まれることによって有機物が分解され、汚水の分解処理効率の高い汚水処理装置を提供することができる。
【００３５】
請求項２に記載の発明によれば、請求項１の効果に加え、
（１）曝気槽を区画する仕切板の貫通孔に通水性を有する多孔質体保持部が配設され、及び／又は、曝気槽が多孔質体保持部で区画されているので、曝気槽内の汚水が多孔質体に接触し易く、汚水に混合された好気性微生物群による有機物の分解処理に加え、多孔質体に生成発達した微生物膜や嫌気性微生物群によって汚水を処理することができ、汚水の処理効率の高い汚水処理装置を提供することができる。
（２）曝気槽内の汚水が多孔質体保持部に収容された多孔質体を通過する際に、浮遊物質等が多孔質体に捕捉され易く、浮遊物質等の分解を促進することができる汚水処理装置を提供することができる。
【００３６】
請求項３に記載の発明によれば、請求項１又は２の効果に加え、
（１）複数の曝気槽が上方で連通された曝気槽連通部を備えているので、汚水が処理されて生成した上澄液を下流側の曝気槽に送って、そこで上澄液をさらに曝気処理することができ処理効率に優れた汚水処理装置を提供することができる。
【００３７】
請求項４に記載の発明によれば、請求項１乃至３の内いずれか１の効果に加え、
（１）曝気槽の上流部の上方に配設された浮遊物質収集部と、収集された浮遊物質を含有する汚水が貯留され分解処理される濃縮分解槽と、を備えているので、分解処理に時間を要する浮遊物質を濃縮分解槽に集め、曝気槽とは別の系統で時間をかけて処理することができ曝気槽の処理効率を高めることができる汚水処理装置を提供することができる。
（２）濃縮分解槽を備えているので、分解処理に時間のかかる浮遊物質を多量に含有した汚水をある程度分解した後に曝気槽に導入することができ、曝気槽内の好気性微生物群等に過剰な負荷を与えることなく効率良く汚水処理を行うことができる汚水処理装置を提供することができる。また、曝気槽内の好気性微生物群の濃度を必要以上に高めることなく汚水の処理を行うことができ、運転経費を低く抑えることができるコスト性に優れた汚水処理装置を提供することができる。
（３）浮遊物質を大量に含む汚水だけを濃縮分解槽内の好気性微生物群等で分解するので、好気性微生物群の濃度は濃縮分解槽内だけを高めればよく、また濃縮分解槽内の高濃度の汚水を餌にして好気性微生物群を増殖させることができるので、コストの高い好気性微生物群が必要最小限の量ですみ運転経費を低く抑えることができるコスト性に優れた汚水処理装置を提供することができる。
【００３８】
請求項５に記載の発明によれば、請求項１乃至４の内いずれか１の効果に加え、
（１）処理水還流部を備え、高濃度の汚水を処理水で希釈することができるので、分解性微生物群に過剰な負荷を与えることなく汚水処理を行うことができる汚水処理装置を提供することができる。
（２）処理水は分解性微生物群を含有しているので、これを繰り返し利用することで曝気槽内の分解性微生物群の濃度を必要以上に高めることなく汚水の処理を行うことができ、運転経費を低く抑えコスト性に優れた汚水処理装置を提供することができる。
（３）処理水還流部を用いて処理水を曝気槽の上流部に還流することで曝気槽の上流部の水位が上昇するので、曝気槽内の水位を平均化するように自然な水流が形成されるため、曝気槽内に水流を形成する手段を配設する必要がなく設備負荷を軽減することができる汚水処理装置を提供することができる。
【図面の簡単な説明】
【図１】実施の形態１における汚水処理装置の要部平面模式図
【図２】図１のＡ−Ａ線における要部断面模式図
【図３】図１のＢ−Ｂ線における要部断面模式図
【符号の説明】
１ 汚水処理装置
２ 汚水貯留槽
３ 第１曝気槽
３ａ，３ｂ 仕切板
４ａ，４ｂ 多孔質体保持部
５ａ，５ｂ 多孔質体
６ 第１上流調整曝気槽
７ 第１中流曝気槽
８ 第１下流曝気槽
９ 第２曝気槽
９ａ 仕切板
９ｂ 多孔質体保持部
９ｃ 多孔質体
１０ 第２上流曝気槽
１１ 第２下流曝気槽
１２ 処理水槽
１３ 濃縮分解槽
１４ 貯留槽連通部
１４ａ，１５ａ，１５ｃ，１６ｂ ポンプ
１５ 処理水還流部
１５ｂ 曝気槽還流部
１６ 分解槽連通部
１６ａ 浮遊物質収集部
１７ａ，１７ｂ，１７ｃ，１７ｄ，２２ａ，２２ｂ，２２ｃ，２２ｄ 散気管
１８，２３ 散気配管
１９ コンプレッサ
２０ 曝気槽連通部
２１ 処理水槽連通部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention treats wastewater containing organic matter such as animal waste such as cattle, horses, sheep, and pigs, human waste, wastewater from a food processing factory, wastewater from a shochu manufacturing factory, and household wastewater such as garbage. The present invention relates to a sewage treatment apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, various biological treatments have been performed as a method for treating wastewater containing organic matter. Above all, an activated sludge method for continuously treating wastewater while circulating a sludge-like microbial conglomerate containing an aerobic bacterial group having an organic substance decomposability is often used.
However, the activated sludge method has a problem that a large capital investment and an operation cost are required, and the equipment load is required. In addition, solid waste such as excess sludge generated during sewage treatment must be incinerated for volume reduction as necessary and disposed of by landfill, etc., and the surrounding environment is contaminated with these disposals. Had the problem that In addition, there is a problem that the location is limited due to the generation of offensive odor during sewage treatment.
Therefore, in recent years, a technology for treating wastewater containing organic matter that hardly generates solid waste such as excess sludge and hardly generates an odor and does not require a load on equipment has been developed.
[0003]
As a conventional technique, (Patent Document 1) discloses that “a sewage treatment apparatus having a raw water tank, an adjustment tank, one or more aeration tanks, and a sedimentation tank includes an aerobic microorganism group at the most downstream position of the sewage treatment apparatus. A sewage treatment apparatus having a concentration tank having a pipe containing water and communicating with a raw water tank is disclosed.
[0004]
(Patent Document 2) describes "a step of sequentially sending wastewater containing organic matter to an adjustment preparation tank, an aeration reaction tank, and a sedimentation separation tank, and the step of sending undecomposed residual substances precipitated and separated in the sedimentation separation tank to the residue decomposition tank. And a step of sending a part of the undecomposed residue sent to the residual decomposition tank to an adjustment preparation tank or an aeration reaction tank.
[0005]
[Patent Document 1]
JP-A-11-262784
[Patent Document 2]
JP-A-2002-18469
[0006]
[Problems to be solved by the invention]
However, the above-described conventional technology has the following problems.
(1) The technologies disclosed in (Patent Document 1) and (Patent Document 2) have a low ability to decompose nitric acid and nitrous acid in sewage, and the efficiency of sewage treatment is low because anaerobic microorganisms are hardly generated in the system. Had the problem of being low.
(2) There is no place in the system where the microorganisms colonize, and it is difficult to form and develop a microbial membrane.
[0007]
The present invention solves the above-mentioned conventional problems, and can generate an anaerobic microorganism group in a system, and can also form and develop a microbial membrane by fixing the microorganism group. It is an object of the present invention to provide a sewage treatment apparatus in which anaerobic microorganisms supplement the work to increase the efficiency of decomposing organic substances and improve the treatment efficiency.
[0008]
[Means for Solving the Problems]
In order to solve the above conventional problems, a sewage treatment apparatus of the present invention has the following configuration.
[0009]
The sewage treatment apparatus according to claim 1 of the present invention comprises one or more aeration tanks for storing and treating sewage in which degrading microorganisms that decompose filth such as aerobic microorganisms are dispersed; A porous body holding portion provided in the aeration tank and having water permeability; a porous body accommodated in the porous body holding portion; and / or (b) formed on an inner wall surface of the aeration tank. Or an uneven portion provided in the aeration tank.
With this configuration, the following operation is obtained.
(1) Since the aeration tank is provided with a porous body and an uneven portion, anaerobic microorganisms are fixed in a portion of the porous body where the amount of dissolved oxygen is low, such as in the pores, between the porous bodies, and in the concave portion of the uneven portion. Can be done. As a result, the aerobic microorganisms mixed with the sewage ingest and oxidize the organic matter in the sewage to be decomposed into water, carbon dioxide, ammonia, etc., and the anaerobic microorganisms oxidize or reduce the organic matter in the sewage. As a result, organic acids, carbon dioxide gas and the like can be generated, and nitric acid and nitrous acid in wastewater can be reduced to generate nitrogen gas and oxidatively decompose organic substances. Thereby, the function of the aerobic microorganisms can be supplemented by the anaerobic microorganisms, and the efficiency of the wastewater decomposition treatment can be increased.
(2) Since a microbial membrane is formed and developed on the surface and irregularities of the porous body, the organic matter in the aeration tank and the organic matter in the sewage are taken into the microbial membrane, whereby the organic matter is decomposed, and the efficiency of the sewage decomposition treatment is improved. Can be enhanced.
[0010]
Here, the sewage includes animal waste such as cows, horses, sheep, pigs, and chickens, human waste, wastewater from food processing plants, factory wastewater from shochu manufacturing plants, and daily life such as garbage and rice juice. Waste containing organic matter such as water from drainage, fish farms, rivers, lakes and marshes is used. It is preferable that coarse garbage and the like are finely divided by crushing or the like and suspended in water. This is for improving the efficiency of the decomposition treatment.
[0011]
As the porous body holding portion, a net formed of metal or synthetic resin, a gauze, a woven fabric, a nonwoven fabric, a permeable membrane, a metal or synthetic resin plate having a plurality of openings are formed. A body or the like having a water permeability formed in a cage shape, a bag shape, a box shape, or the like is used, and a porous body is accommodated therein.
The porous body holding section in which the porous body is accommodated is disposed at a predetermined position in the aeration tank, and at least a part thereof is immersed in sewage.
[0012]
As the porous body, carbonaceous materials such as charcoal, bamboo charcoal, activated carbon and the like, perlite, vermiculite, zeolite, foamed glass and the like, which have irregularities and fine holes formed on the surface thereof are used. In particular, carbonaceous materials are preferred. This is because the surface has countless micropores, and the microorganism group is easily fixed.
It is preferable to use a porous body having a mean particle size of 2 to 50 mm and formed in a granular shape or a flake shape. This is because the surface area of the porous body can be increased to increase the number of pores that come into contact with the sewage, and also increase the area where the microbial membrane can be formed and developed. In addition, the number of contact points between the porous bodies increases, and the number of anaerobic microorganisms generated can be increased.
As the average particle diameter of the porous body becomes smaller than 2 mm, there is a tendency that many pores of the porous body are destroyed and anaerobic microorganisms tend to be hardly generated, and the average particle diameter becomes larger than 50 mm. As the surface area of the porous body becomes smaller, the number of pores that come into contact with the wastewater and the number of contact points between the porous bodies decrease, and the tendency that anaerobic microbial groups hardly occur is observed.
The meshes and openings of the porous body holding portion are formed in such a size that the contained porous body does not flow out. In addition, the porous body holding portion can be completely wrapped or provided with a lid or the like as necessary. This is because even when a porous material having a small specific gravity is used, it does not float and disperse.
[0013]
As the uneven portion, a base material having fine irregularities when the inner wall surface of the aeration tank is formed of concrete or the like, a thermal spray coating or blasting when the inner wall surface of the aeration tank is formed of a metal plate or the like. For example, a rough surface formed by a method such as a mesh or a mesh formed of a metal or a synthetic resin and disposed in an aeration tank is used.
As the surface roughness of the uneven portion, a maximum height of 0.1 to 5 mm specified by JIS B0601-1994 is preferably used. As the maximum height becomes smaller than 0.1 mm, there is a tendency that anaerobic microorganisms are less likely to have small irregularities, and as the maximum height becomes larger than 5 mm, the surface area of the irregularities becomes smaller and anaerobic microorganisms are less likely to be produced. Either of them is not preferable because there is a tendency that the toner is easily washed away and is hardly fixed.
[0014]
To the wastewater in the aeration tank, in addition to the degrading microorganisms of the aerobic microorganisms and the anaerobic microorganisms, an enzyme group that degrades proteins and lipids can be added and dispersed. Thereby, it is possible to promote the decomposition of proteins and oils and fats contained in the sewage, thereby increasing the efficiency of the sewage decomposition treatment.
[0015]
As the degradable microorganisms, microorganisms such as aerobic and anaerobic bacteria, fungi, and protozoa are used. In particular, those obtained by storing manure of livestock such as pigs in viscous soil or concrete in a dark room in the presence of oxygen, and aging and concentrating while evaporating water for a certain period of time are preferably used.
The following effects can be obtained by using a degrading microorganism group utilizing intestinal bacterial groups contained in manure of livestock such as pigs.
(1) Enzymes are produced by aging and concentrating manure containing the intestinal bacteria of livestock. Since the degrading microorganisms contain enzymes, the organic matter in the wastewater is almost completely decomposed, and the amount of solid waste such as excess sludge can be reduced to almost zero. Although the reason is unknown, it is said that the enzymes act as catalysts when destroying the cell wall of organic matter, and that they break down the organic matter whose cell wall has been broken down into carbon dioxide, water, nitrogen gas, etc. I guess.
(2) The decomposition time of organic substances is short, and odor is unlikely to occur. Although the reason is unknown, it is speculated that the decomposition of organic substances is a catalytic reaction by the enzyme group and the reaction time is short.
(3) Since the amount of treated water generated by processing the sewage is smaller than the supply amount of the sewage into the system, the treated water is circulated and used as dilution water for the sewage to discharge the treated water to the outside of the system. It does not emit and does not pollute the surrounding environment such as rivers. Although the reason is unknown, it is because the enzymes consume a large amount of water when decomposing organic substances, and it is speculated that the enzymes decompose water into hydrogen gas and oxygen gas.
[0016]
As a result of the analysis, the intestinal bacterial groups contained in the manure of livestock include spore-free gram-positive bacilli (Group 20), gram-positive bacilli (coryneform bacterium, coryneform bacteria), and gram-positive cocci (stane-form bacterium) , Stapneform bacteria), Pseudomonas aer Guinot Sa (Pseudomonas aeruginosa, Pseudomonasaeruginosa), Pseudomonas scan caught jelly (Pseudomonas Stutzeri), Serratia requesters tumefaciens (Serratia Liguefaciens), Serratia circle set sense (Serratiamarcescens), Stenotrophomonas Marthe feeler (Stenotrophomonasmaltophilia ), Bacillus sp. haericus).
As the degrading microorganisms utilizing intestinal bacteria contained in the excrement of livestock such as pigs, for example, Yabe bacteria (trade name: Earthlab, manufactured by Earthlab Nippon) can be used.
[0017]
In addition, when the dissolved oxygen amount of the sewage in the aeration tank is adjusted to be 6 to 10 ppm according to the BOD value of the sewage, the energy consumption for aeration is small and the activity of the aerobic microorganism group is increased. This is preferable because the decomposition treatment efficiency can be increased. The activity of the aerobic microorganisms tends to decrease as the dissolved oxygen content becomes less than 6 ppm, and the energy consumption for aeration tends to increase as the dissolved oxygen content becomes more than 10 ppm, which is not preferable.
[0018]
The invention according to claim 2 is the sewage treatment apparatus according to claim 1, wherein (a) the aeration tank is partitioned by a partition plate having a through hole formed in a predetermined portion, and the porous body holding member is held. A portion is provided in the through-hole, and / or (b) the aeration tank is divided by one or a plurality of the porous body holding portions.
With this configuration, the following operation is obtained in addition to the operation obtained in the first aspect.
(1) Since the porous body holding portion having water permeability is disposed in the through hole of the partition plate that partitions the aeration tank, and / or the aeration tank is partitioned by the porous body holding portion, the inside of the aeration tank is Wastewater easily contacts the porous body, and in addition to the decomposition of organic matter by the aerobic microorganisms mixed with the wastewater, the wastewater can be treated by the microbial membranes and anaerobic microorganisms formed and developed on the porous body. , The efficiency of wastewater treatment can be increased.
(2) When the sewage in the aeration tank passes through the porous body accommodated in the porous body holding portion, the floating substance and the like are easily captured by the porous body, and the decomposition of the floating substance and the like can be promoted. .
[0019]
Here, it is desirable that the sewage be supplied to an upstream portion on one end side of the aeration tank divided into a plurality of sections. Since the sewage treatment equipment is used in a closed system, the natural water flow is formed so that the water level in the upstream of the aeration tank to which the sewage is supplied rises and the water level in the aeration tank is averaged. There is no need to provide a means for forming a water flow in the tank, and no equipment load is required.Furthermore, when sewage passes through the porous body accommodated in the porous body holding part, floating substances and the like are converted to the porous body. This is because they are easily captured.
[0020]
The invention according to claim 3 is the sewage treatment apparatus according to claim 1 or 2, wherein the aeration tank has a plurality of the aeration tanks, and the plurality of aeration tanks are communicated above the aeration tank. It has a configuration provided with a communication portion.
With this configuration, the following operation is obtained in addition to the operation obtained in the first or second aspect.
(1) Since a plurality of aeration tanks are provided with an aeration tank communication part communicated upward, the supernatant liquid generated by treating the sewage is sent to the downstream aeration tank, where the supernatant liquid is further aerated. It can be processed and has excellent processing efficiency.
[0021]
The invention according to claim 4 of the present invention is the sewage treatment apparatus according to any one of claims 1 to 3, wherein the sewage is disposed above an upstream part of the aeration tank and contains suspended matter. And a concentration / decomposition tank in which the wastewater collected by the suspended substance collection unit is stored and decomposed.
With this configuration, the following operation is obtained in addition to the operation obtained in any one of the first to third aspects.
(1) Since there is provided a suspended solids collecting section disposed above the upstream part of the aeration tank and a concentration and decomposition tank for storing and decomposing wastewater containing collected suspended solids, the decomposition treatment is performed. The suspended solids that require a long time are collected in a concentration and decomposition tank, and can be treated with degrading microorganisms or the like over a long period of time in a system different from the aeration tank, thereby improving the processing efficiency of the aeration tank.
(2) Since a concentration / decomposition tank is provided, it is possible to decompose sewage containing a large amount of suspended solids, which takes a long time to decompose, and then introduce the sewage into the aeration tank. Wastewater treatment can be performed without imposing a heavy load. In addition, sewage treatment can be performed without unnecessarily increasing the concentration of the degrading microorganisms in the aeration tank, and operating costs can be kept low.
(3) Since only wastewater containing a large amount of suspended matter is decomposed by the degrading microorganisms in the concentration and decomposition tank, the concentration of the degrading microorganisms may be increased only in the concentration and decomposition tank, and Since high-concentration sewage can be used as feed to grow the degradable microorganisms, the cost of the degradable microorganisms can be kept to a minimum and the operation cost can be kept low.
[0022]
Here, as the concentration and decomposition tank, a tank provided with an aeration device is used. This is to activate the function of the aerobic microorganisms mixed in the sewage and to prevent anaerobic decay of the sewage in the concentration and decomposition tank.
[0023]
It is preferable to connect a decomposition tank communication part communicating with the concentration and decomposition tank to the suspended solids collection part, and to provide a conveying means such as a pressure pump in the decomposition tank communication part. This is because the sewage containing the suspended matter collected by the suspended matter collecting part can be supplied to the concentration and decomposition tank through the decomposition tank communication part by using the transport means. In addition, the wastewater collected by the suspended solids collection unit can be transported and supplied to the concentration / decomposition tank by human power or the like without providing the communication unit of the decomposition tank or the transporting means.
[0024]
The invention according to claim 5 of the present invention is the sewage treatment apparatus according to any one of claims 1 to 4, wherein the sewage treated in the aeration tank is treated upstream of the aeration tank. It has a configuration provided with a treated water reflux section for refluxing in the section.
With this configuration, the following operation is obtained in addition to the operation obtained in any one of the first to fourth aspects.
(1) Since a treated water recirculation unit is provided and high-concentration sewage can be diluted with treated water, sewage treatment can be performed without imposing an excessive load on the degrading microorganisms.
(2) Since the treated water contains the degrading microorganisms, the wastewater can be treated without repeatedly increasing the concentration of the degrading microorganisms in the aeration tank by using this repeatedly. Operating costs can be kept low.
(3) By returning the treated water to the upstream part of the aeration tank using the treated water reflux part, the water level in the upstream part of the aeration tank rises, so that a natural water flow is created so as to average the water level in the aeration tank. Since it is formed, it is not necessary to provide a means for forming a water flow in the aeration tank, and the load on equipment can be reduced.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a schematic plan view of a main part of a sewage treatment apparatus according to Embodiment 1 of the present invention, FIG. 2 is a schematic cross-sectional view of a main part along line AA in FIG. 1, and FIG. It is a principal part cross-section schematic diagram in the -B line.
In FIG. 1, reference numeral 1 denotes a sewage treatment apparatus according to the first embodiment; A sewage storage tank for storing sewage containing organic waste such as household wastewater such as garbage and rice juice, 3 is a first aeration tank as an aeration tank connected to the sewage storage tank 2, 3a, 3b. Is a partition plate which divides the inside of the first aeration tank 3 into three tanks, and 4a, 4b are formed in a box shape or the like by a wire mesh having water permeability through through holes formed in predetermined portions of the partition plates 3a, 3b. The provided porous body holders 5a and 5b are formed of granules having an average particle diameter of 2 to 50 mm and the like, and porous bodies such as charcoal and bamboo charcoal contained in the porous body holders 4a and 4b, respectively. Dilution adjustment of the concentration of sewage as the upstream part of the first aeration tank 3 divided by the partition plate 3a and the porous body holding part 4a A first upstream adjusting aeration tank, 7 is a first middle aeration tank of the first aeration tank 3 divided by the partition plate 3a, the porous body holding portion 4a and the partition plate 3b, the porous body holding portion 4b, and 8 is a partition. A first downstream aeration tank of the first aeration tank 3 partitioned by the plate 3b and the porous body holding portion 4b, and a second aeration tank 9 as an aeration tank connected to and communicated with a part of the first aeration tank 3 , 9a is a partition plate which divides the inside of the second aeration tank 9 into two tanks, 9b is a box-shaped or the like formed by a wire mesh or the like having water permeability in a through hole formed in a predetermined portion of the partition plate 9a. The porous body holding portion 9c is a porous body such as charcoal or bamboo charcoal which is formed in a granular shape having an average particle diameter of 2 to 50 mm and is accommodated in the porous body holding portion 9b, 10 is a partition plate 9a, a porous body A second upstream aeration tank of the second aeration tank 9 partitioned by the holding section 9b, 11 is a second aeration section partitioned by the partition plate 9a and the porous body holding section 9b. Reference numeral 9 denotes a second downstream aeration tank, 12 is a treated water tank connected to the second downstream aeration tank 11 of the second aeration tank 9 and connected to the first upstream regulated aeration tank 6 of the first aeration tank 9, and 13 is a treated water tank 12 , A concentration / decomposition tank connected to the sewage storage tank 2, a storage tank communication part 14 formed of a pipe connecting the lower part of the sewage storage tank 2 and the first upstream aeration tank 6, and 14 a a storage tank communication part 14. A pump for pumping high-concentration sewage stored in the sewage storage tank 2 into the first upstream adjustment aeration tank 6 and supplying a fixed amount thereof, and 15 is an upstream part of the treatment water tank 12 and the first aeration tank 3. A treated water recirculation section 15a comprising a pipe communicating with the first upstream regulated aeration tank 6 is disposed in the treated water recirculation section 15, and the treated water in the treated water tank 12 is supplied to the first upstream regulated aeration tank 6 as required. Pump 15b is a lower part of the second downstream aeration tank 11 which is a downstream part of the second aeration tank 9 and a first aeration. The aeration tank recirculation section 15c, which is a pipe body communicating with the upper portion of the first upstream adjustment aeration tank 6 which is the upstream section of the tank 3, is disposed in the aeration tank recirculation section 15b to remove the wastewater from the second downstream aeration tank 11 1, a pump for pumping to the upstream adjusting aeration tank 6; 16 is a decomposition tank communicating portion formed of a pipe communicating the first upstream adjusting aeration tank 6 upstream of the first aeration tank 3 with the concentration / decomposition tank 13; A floating substance collecting part formed in a funnel shape or the like which is disposed above the first upstream regulating aeration tank 6 at an end of the tank communicating part 16 and collects sewage containing the floating substance, and 16b is a decomposition tank communicating part 16 And a pump for pumping sewage in the first upstream regulation aeration tank 6 to the concentration and decomposition tank 13.
Here, in the present embodiment, at least a lower portion of the sewage storage tank 2 and the concentration / decomposition tank 13 are connected to each other by one or a plurality of communication holes which are provided with an on-off valve (not shown) and which can be opened and closed. ing. In the following description, a case will be described in which the on-off valve is closed and the sewage storage tank 2 and the concentration / decomposition tank 13 are completely separated.
[0026]
In FIG. 2, oxygen-containing gases 17a, 17b, 17c and 17d are respectively disposed at the bottoms of the sewage storage tank 2, the first upstream aeration tank 6, the first middle aeration tank 7 and the first downstream aeration tank 8. Is a diffuser pipe for aeration in each tank, 18 is a diffuser pipe connected to the diffuser pipes 17a, 17b, 17c, 17d, and 19 is a compressor such as an air pump connected to the diffuser pipe 18 to pump gas. .
In FIG. 3, reference numeral 20 denotes an aeration tank communication part in which a first downstream aeration tank 8 of the first aeration tank 3 and a second upstream aeration tank 10 of the second aeration tank 9 are communicated near the surface of the sewage above each. Reference numeral 21 denotes a treatment water tank communication part in which the second downstream aeration tank 11 and the treatment water tank 12 communicate with each other in the vicinity of the upper water surface, and reference numerals 22a, 22b, 22c, and 22d denote concentration / decomposition tanks 13, treatment water tanks 12, and second downstream aeration. A diffuser pipe, which is provided at the bottom of the tank 11 and the second upstream aeration tank 10 and injects a gas containing oxygen to perform aeration in each tank, 23 is connected to the diffuser pipes 22a, 22b, 22c, 22d and connected to the other end. Is an air diffuser pipe connected to the compressor 19.
[0027]
A method of using the sewage treatment apparatus according to Embodiment 1 configured as described above will be described below.
First, while storing a predetermined amount of water in the first aeration tank 3, the second aeration tank 9, the treatment water tank 12, and the concentration decomposition tank 13, the first aeration tank 3, the second aeration tank 9, the treatment water tank 12, A predetermined amount of degradable microorganisms such as aerobic and anaerobic bacteria such as Yabe fungi (trade name: Earthlab, manufactured by Earthlab Nippon), fungi, protozoa, etc. are mixed in the decomposition tank 13. Spread. Next, the compressor 19 is driven to blow out a gas containing oxygen from the diffuser pipes 17b, 17c, 17d, 22a, 22b, 22c, 22d, so that the first upstream adjusting aeration tank 6 of the first aeration tank 3 and the first middle-flow aeration. The aeration of the tank 7, the first downstream aeration tank 8, the second upstream aeration tank 10 of the second aeration tank 9, the second downstream aeration tank, the treatment water tank 12, and the concentration decomposition tank 13 is performed. The sewage storage tank 2 stores sewage containing organic matter such as animal waste, human waste, factory wastewater, domestic wastewater, and the like. The sewage storage tank 2 can also perform aeration using the air diffuser 17a.
Next, the pump 14a is driven to supply a predetermined amount of the sewage stored in the sewage storage tank 2 from the storage tank communication section 14 to the first upstream adjustment aeration tank 6, and the high concentration sewage is supplied to the first upstream adjustment aeration tank 6 Dilute with water. The supply amount of the sewage supplied quantitatively to the first upstream adjustment aeration tank 6 by driving the pump 14a is adjusted according to the BOD value of the sewage. This is to prevent an excessive burden on the degrading microorganisms in the first upstream regulation aeration tank 6. The sewage supplied to the first upstream adjustment aeration tank 6 is decomposed by the degrading microorganisms in the first upstream adjustment aeration tank 6. The high-concentration sewage containing suspended matter above the first upstream regulating aeration tank 6 is collected by the suspended matter collection part 16a by driving the pump 16b, and is conveyed to the concentration and decomposition tank 13 through the decomposition tank communication part 16. You. The high-concentration sewage containing suspended substances transported to the concentration and decomposition tank 13 is decomposed by the degrading microorganisms in the concentration and decomposition tank 13. The sewage decomposed over time in the concentration / decomposition tank 13 and the degradable microorganisms proliferated in the concentration / decomposition tank 13 are supplied to the first upstream regulating aeration tank 6 by a pump (not shown) or the like to be continuously decomposed. Done.
[0028]
Since the water level in the first upstream adjustment aeration tank 6 rises due to the supply of the sewage into the first upstream adjustment aeration tank 6, the sewage in the first upstream adjustment aeration tank 6 is removed from the first upstream adjustment aeration tank 6. After passing through the porous body 5a accommodated in the porous body holding portion 4a so as to keep the water level constant, the water enters the first middle-flow aeration tank 7, and the degradable microorganisms and porous material in the first middle-flow aeration tank 7 It is decomposed by the anaerobic microorganisms generated in the body 5a. The sewage in the first midstream aeration tank 7 then passes through the porous body 5b accommodated in the porous body holding unit 4b, enters the first downstream aeration tank 8, and decomposes in the first downstream aeration tank 8. It is decomposed by the anaerobic microorganisms and the anaerobic microorganisms generated in the porous body 5b.
The supernatant liquid of the sewage decomposed in the first downstream aeration tank 8 passes through the aeration tank communication section 20 and enters the second upstream aeration tank 10. The sewage in the second upstream aeration tank 10 then passes through the porous body 9c accommodated in the porous body holding portion 9b, enters the second downstream aeration tank 11, and is aerobic in the second downstream aeration tank 11. Decomposition treatment is performed by the microorganisms and the anaerobic microorganisms generated in the porous body 9c. The sewage that has reached the second downstream aeration tank 11 is supplied into the first upstream adjustment aeration tank 6 through the aeration tank recirculation section 15b communicating with the lower portion of the second downstream aeration tank 11 by driving the pump 15c. Decomposition is repeatedly performed in the first aeration tank 3 and the second aeration tank 9. The supernatant (treated water) of the sewage decomposed in the second downstream aeration tank 11 passes through the treated water tank communication section 21 and enters the treated water tank 12. As described above, the sewage diluted in the first upstream regulation aeration tank 6 passes through the first middle aeration tank 7, the first downstream aeration tank 8, the second upstream aeration tank 10, and the second downstream aeration tank 11. As it progresses, organic matter in the sewage is decomposed by degrading microorganisms and becomes treated water.
The treated water that has entered the treated water tank 12 is supplied from the treated water recirculation unit 15 to the first upstream adjustment aeration tank 6 by driving the pump 15a, and dilutes the sewage in the first upstream adjustment aeration tank 6.
[0029]
As described above, since the sewage treatment apparatus according to Embodiment 1 is configured, the following operation is obtained.
(1) Since a porous body holding portion provided in the first aeration tank and the second aeration tank and having water permeability and a porous body accommodated in the porous body holding portion are provided, the porous body is provided. Anaerobic microorganisms can be generated in a portion having a small amount of dissolved oxygen, such as in the pores or between porous bodies. As a result, the aerobic microorganisms mixed with the sewage ingest and oxidize the organic matter in the sewage to be decomposed into water, carbon dioxide, ammonia, etc., and the anaerobic microorganisms oxidize or reduce the organic matter in the sewage. As a result, organic acids, carbon dioxide gas and the like can be generated, and nitric acid and nitrous acid in wastewater can be reduced to generate nitrogen gas and oxidatively decompose organic substances. Thereby, the function of the aerobic microorganisms can be supplemented by the anaerobic microorganisms, and the efficiency of the wastewater decomposition treatment can be increased.
(2) Since a microbial membrane is formed and developed on the surface of the porous body, the oxygen in the aeration tank and the organic matter in the sewage are taken into the microbial membrane, whereby the organic matter is decomposed and the efficiency of the sewage decomposition treatment is improved. it can.
(3) Since the porous body holding portion having water permeability is formed on the partition plate that partitions the first aeration tank and the second aeration tank, sewage in the aeration tank easily comes into contact with the porous body, and In addition to the decomposition treatment of organic substances by the mixed aerobic microorganisms, sewage can be treated by the microbial membranes and anaerobic microorganisms formed and developed on the porous body, and the treatment efficiency of sewage can be increased.
(4) When the sewage in the first aeration tank or the second aeration tank passes through the porous body accommodated in the porous body holding unit, the floating substance and the like are easily captured by the porous body, and the Decomposition can be promoted.
(5) Since the first aeration tank and the second aeration tank are provided with an aeration tank communication part communicated upward, the supernatant liquid generated by treating the sewage is sent to the downstream aeration tank, where it is discharged. The supernatant can be further aerated and the processing efficiency is excellent.
(6) a suspended solids collecting section disposed above the first upstream regulating aeration tank upstream of the first aeration tank, and a concentrated decomposition tank in which wastewater containing collected suspended substances is stored and decomposed. , The suspended matter that requires time for the decomposition treatment is collected in the concentration and decomposition tank, and can be processed over a long time in a system different from the aeration tank, so that the processing efficiency of the aeration tank can be increased.
(7) Since it has a concentration / decomposition tank, it can be introduced into the aeration tank after decomposing to some extent sewage containing a large amount of suspended matter that takes time to decompose. Sewage treatment can be performed without giving an excessive load. In addition, sewage treatment can be performed without unnecessarily increasing the concentration of aerobic microorganisms in the aeration tank, and operation costs can be kept low.
(8) Since only sewage containing a large amount of suspended matter is decomposed by the aerobic microorganisms in the concentration and decomposition tank, the concentration of the aerobic microorganisms may be increased only in the concentration and decomposition tank. The aerobic microorganisms can be grown in the concentration / decomposition tank, and the costly aerobic microorganisms can be kept in a minimum necessary amount and the operating cost can be kept low.
(9) Since the treatment water recirculation section is provided, and high-concentration wastewater can be diluted with the treatment water, the wastewater treatment can be performed without imposing an excessive load on the degrading microorganisms.
(10) Since the treated water contains the degrading microorganisms, the treated water is returned to the first upstream regulating aeration tank in the treated water reflux section, and is repeatedly circulated and used in a closed system. Sewage treatment can be performed without unnecessarily increasing the concentration of the degrading microorganisms in the aeration tank, and operation costs can be kept low.
(11) Since the water level in the upstream part of the aeration tank rises by returning the treated water to the upstream part of the aeration tank using the treated water recirculation part, a natural water flow is created so as to average the water level in the aeration tank. Since it is formed, it is not necessary to provide a means for forming a water flow in the aeration tank, and the load on equipment can be reduced.
(12) Since the porous body is formed into particles or flakes having an average particle diameter of 2 to 50 mm, the surface area of the porous body is increased to increase the number of pores that come into contact with sewage and to form a microbial membrane. The area that can be developed can be increased, and the number of contact points between the porous bodies can be increased, thereby increasing the number of anaerobic microorganisms generated. Thereby, the treatment efficiency of sewage can be improved.
(13) Since the diffuser pipe for aeration is provided in the sewage storage tank, it is possible to prevent sewage in the sewage storage tank from causing anaerobic decay.
(14) Since the sewage stored in the sewage storage tank is quantitatively supplied to the first upstream adjustment aeration tank by a pump, the water level in the first upstream adjustment aeration tank rises, thereby discharging the wastewater into the first middle flow aeration tank. A natural water flow that is sequentially moved in the first downstream aeration tank can be formed, and the processing efficiency can be increased. In addition, since high-concentration sewage is quantitatively supplied to the first upstream aeration tank by a pump and diluted with water in the first upstream aeration tank, excessive load is applied to the aerobic microorganisms in the first upstream aeration tank. , And the processing efficiency can be improved.
(15) Since the communication between the sewage storage tank and the concentration / decomposition tank is made through a communication hole formed to be openable and closable, the sewage storage tank is not used and the sewage generation source or the like directly passes to the first upstream adjustment aeration tank. When supplying sewage, the sewage storage tank and the concentration / decomposition tank are communicated with each other, and the whole is used as the concentration / decomposition tank, so that the capacity of the concentration / decomposition tank can be increased, and the flexibility is excellent.
(16) Since an aeration tank recirculation section is provided for communicating the lower part of the second downstream aeration tank with the first upstream adjustment aeration tank, the sewage that has reached the second downstream aeration tank is supplied into the first upstream adjustment aeration tank. Then, the first aeration tank and the second aeration tank can be circulated in the closed system for decomposition treatment, and the processing capacity can be increased.
(17) Since the aeration tank reflux section is provided, a water flow from the first aeration tank to the second aeration tank can be formed, and sewage can be passed through the porous body accommodated in the porous body holding unit. It can promote the decomposition of sewage.
[0030]
The case where the first aeration tank 3 is divided into three tanks by the partition plate and the second aeration tank 9 is divided into two tanks has been described. However, depending on the size of the sewage treatment device and the type of sewage, each aeration tank is different. Can be increased or decreased. Also, the case where two tanks of the first aeration tank 3 and the second aeration tank 9 are formed in the sewage treatment apparatus has been described. However, depending on the size of the sewage treatment apparatus and the type of sewage, only one aeration tank is required. Often, three or more tanks can be formed.
In addition, after the high-concentration wastewater containing suspended substances is decomposed in the concentration / decomposition tank 13, the concentrated decomposition / decomposition tank 13 and the wastewater storage tank are conveyed to the decomposed product to the wastewater storage tank 2 or the first upstream regulation aeration tank 6. A communication part consisting of a pipe communicating the tank 2 and a communication part consisting of a pipe communicating the concentration / decomposition tank 13 and the first upstream adjustment aeration tank 6 are provided, and each communication part is provided using a conveying means such as a pump. Can be conveyed through. Thus, it is not necessary to transport the processed material manually, and the workability is excellent.
Further, instead of the partition plates 3a, 3b, 9a, the inside of the aeration tank can be partitioned by the porous body holding portions 4a, 4b, 9b. In this case, the same operation can be obtained.
Further, the inner wall surfaces of the first aeration tank 3 and the second aeration tank 9 may be formed of concrete or the like, or a mesh or the like may be provided in the first aeration tank 3 or the second aeration tank 9 in accordance with JIS B0601-1994. In some cases, irregularities having a surface roughness of 0.1 to 5 mm at the maximum height defined by the above are formed or arranged. Also in this case, an aerobic microorganism group, an anaerobic microorganism group, or the like can be fixed on the uneven portion, and the decomposition treatment efficiency can be increased.
Further, the case where the sewage storage tank 2 for storing sewage is provided has been described. However, there is a case where sewage is supplied quantitatively from the sewage generation source or the like directly into the first upstream regulation aeration tank without disposing the sewage storage tank. . In this case, the same operation can be obtained.
Further, a drainage channel provided with a pump may be provided in the treated water tank 12 to discharge the treated water in the treated water tank 12 out of the system. Thereby, when the water level of the treated water rises, the treated water can be discharged to a river, a water purification plant, or the like, and can be used as washing water for a pig farm, a poultry house, or other livestock stalls. Since the treated water contains degraded microorganisms as well as decomposed organic substances, it does not impose a burden on the surrounding environment even when discharged into a river or a water treatment plant.
[0031]
【Example】
Hereinafter, the present invention will be described specifically with reference to examples. Note that the present invention is not limited to these examples.
(Example 1)
The sewage decomposition treatment was performed using the sewage treatment apparatus described in the first embodiment. The capacity of each tank of the sewage treatment equipment is 0.84 m 3 , 1st upstream regulating aeration tank 1.17m 3 , The first midstream aeration tank 1.38m 3 , First downstream aeration tank 1.17m 3 , Second upstream aeration tank 1.17m 3 , Second downstream aeration tank 1.38m 3 , Treated water tank 1.17m 3 0.84m 3 Met. The porous body holding portion is formed using a metal net in a box shape having a width of 0.7 m, a thickness of 0.24 m, and a height of 0.9 m, and each porous body holding portion has a granular porous material having an average particle diameter of 3 mm. 0.15m each charcoal 3 Housed.
The first upstream regulating aeration tank, the first midstream aeration tank, the first downstream aeration tank, the second upstream aeration tank, the second downstream aeration tank, and the treated water tank of the above-described sewage treatment apparatus are 6 m in total. 3 Of water and 300 kg of liquid Yabe bacteria group (trade name: Earthlab, manufactured by Earthlab Japan) as a degrading microorganism group. Next, the dissolved oxygen amount of water in the first upstream aeration tank, the first middle aeration tank, the first downstream aeration tank, the second upstream aeration tank, and the second downstream aeration tank is set to 6 to 10 ppm. Air was supplied to each tank from an air diffuser arranged at the bottom. Next, pig manure as sewage 0.1m 3 Was stored in the sewage storage tank, the pump was driven to supply a constant amount of sewage from the sewage storage tank into the first upstream aeration tank at a flow rate of 4 L / min, and the treatment of sewage was started. Twenty-four hours later, the treated water in the treated water tank was collected and the BOD was measured. The measurement of BOD was based on JIS K01021 21 and 32.3. The BOD of the sewage before treatment (pig manure diluted 60 times with water) was 800 mg / L.
[0032]
The BOD of the treated water (treated for 24 hours) collected from the upper part of the treated water tank was 170 mg / L. Further, the treated water did not smell at all. Based on the decrease in BOD after 24 hours, it was expected that the BOD would be about 20 mg / L after 48 hours.
According to the present example, it has been clarified that the BOD of treated water can be significantly reduced in a short time of 24 hours and sewage treatment capable of removing odor can be performed.
Furthermore, it was found that the organic matter in the sewage can be almost completely decomposed and the amount of solid waste such as excess sludge can be reduced to almost zero. This is because Yabe bacteria used as degrading microorganisms contain enzymes generated by aging and concentrating manure containing intestinal bacteria in livestock, and the enzymes destroy cell walls of organic matter In addition to acting as a catalyst at the time, it is speculated that the organic matter whose cell walls have been destroyed is nourished and decomposed into carbon dioxide, water, nitrogen gas and the like.
Further, the water levels of the sewage and water in the sewage treatment apparatus after the aeration treatment for 24 hours were lower than the water levels of the sewage and water before the treatment. As a result, it became clear that by circulating the treated water as the diluting water, the treated water was not discharged to the outside of the system and pollution of the surrounding environment such as rivers could be prevented. This is because a large amount of water is consumed when the enzyme group contained by the Yabe bacterium decomposes organic matter, and it is speculated that the enzyme group decomposes water into hydrogen gas and oxygen gas.
[0033]
(Comparative Example 1)
The porous body holding portion provided in the sewage treatment apparatus used in Example 1 is removed together with the porous body, and a first upstream aeration tank, a first middle aeration tank, a first downstream aeration tank, a second upstream aeration tank are provided. The sewage treatment apparatus of Comparative Example 1 was prepared by connecting the tank and the second downstream aeration tank without passing through the porous body.
Using the sewage treatment apparatus of Comparative Example 1, sewage treatment was performed under the same conditions as in Example 1, and after 24 hours from the introduction of sewage, treated water was collected from the upper part of the treated water tank and BOD was measured. .
As a result, the measured BOD was 230 mg / L, which was about 30% larger than the BOD of the treated water treated by the sewage treatment apparatus of Example 1.
As described above, according to the present embodiment, since a porous body is provided in the system, an anaerobic microorganism group can be generated, and the microorganism group can be fixed to form and develop a microbial membrane. Therefore, it became clear that the function of the aerobic microorganisms was supplemented by the anaerobic microorganisms, and the decomposition efficiency of organic matter was increased and the treatment efficiency was excellent.
[0034]
【The invention's effect】
As described above, according to the sewage treatment apparatus of the present invention, the following advantageous effects can be obtained.
According to the first aspect of the present invention,
(1) Since the aeration tank is provided with the porous body and the irregularities, anaerobic microorganisms can be generated in the pores of the porous body, between the porous bodies, in the recesses of the irregularity, and the like. As a result, the aerobic microorganisms mixed with the sewage ingest and oxidize the organic matter in the sewage to be decomposed into water, carbon dioxide, ammonia, etc., and the anaerobic microorganisms oxidize or reduce the organic matter in the sewage. As a result, organic acids, carbon dioxide gas and the like can be generated, and nitric acid and nitrous acid in wastewater can be reduced to generate nitrogen gas and oxidatively decompose organic substances. Thereby, the function of the aerobic microorganisms is supplemented by the anaerobic microorganisms, so that it is possible to provide a sewage treatment apparatus with high efficiency of sewage decomposition treatment.
(2) Since a microbial membrane is formed and developed on the surface and irregularities of the porous body, the organic matter is decomposed by the oxygen in the aeration tank and the organic matter in the sewage being taken into the microbial membrane. A high sewage treatment apparatus can be provided.
[0035]
According to the invention described in claim 2, in addition to the effect of claim 1,
(1) Since the porous body holding portion having water permeability is disposed in the through hole of the partition plate that partitions the aeration tank, and / or the aeration tank is partitioned by the porous body holding portion, the inside of the aeration tank is Wastewater easily contacts the porous body, and in addition to the decomposition of organic matter by the aerobic microorganisms mixed with the wastewater, the wastewater can be treated by the microbial membranes and anaerobic microorganisms formed and developed on the porous body. Thus, it is possible to provide a sewage treatment apparatus with high sewage treatment efficiency.
(2) When the sewage in the aeration tank passes through the porous body accommodated in the porous body holding portion, the floating substance and the like are easily captured by the porous body, and the decomposition of the floating substance and the like can be promoted. A sewage treatment apparatus can be provided.
[0036]
According to the invention described in claim 3, in addition to the effect of claim 1 or 2,
(1) Since a plurality of aeration tanks are provided with an aeration tank communication part communicated upward, the supernatant liquid generated by treating the sewage is sent to the downstream aeration tank, where the supernatant liquid is further aerated. It is possible to provide a sewage treatment apparatus which can be treated and has excellent treatment efficiency.
[0037]
According to the invention described in claim 4, in addition to the effect of any one of claims 1 to 3,
(1) Since there is provided a suspended solids collecting section disposed above the upstream part of the aeration tank and a concentration and decomposition tank for storing and decomposing wastewater containing collected suspended solids, the decomposition treatment is performed. It is possible to provide a sewage treatment apparatus capable of collecting suspended substances which require a long time in a concentration and decomposition tank and treating the suspended substance in a system different from the aeration tank over time, thereby improving the treatment efficiency of the aeration tank.
(2) Since it has a concentration / decomposition tank, it is possible to decompose sewage containing a large amount of suspended solids that takes a long time to decompose and introduce it into the aeration tank after it has been decomposed to some extent. A sewage treatment apparatus capable of efficiently performing sewage treatment without giving an excessive load can be provided. In addition, it is possible to provide a highly cost-effective sewage treatment apparatus that can perform sewage treatment without unnecessarily increasing the concentration of the aerobic microorganisms in the aeration tank, thereby reducing operating costs. .
(3) Since only sewage containing a large amount of suspended matter is decomposed by the aerobic microorganisms in the concentration and decomposition tank, the concentration of the aerobic microorganisms may be increased only in the concentration and decomposition tank. High-concentration sewage can be used to feed and aerobic microorganisms can be proliferated, so the costly aerobic microorganisms can be kept to a minimum and the operating cost can be kept low. An apparatus can be provided.
[0038]
According to the invention described in claim 5, in addition to the effect of any one of claims 1 to 4,
(1) Provided is a sewage treatment apparatus that includes a treated water recirculation section and can dilute high-concentration sewage with treated water, so that sewage treatment can be performed without imposing an excessive load on degrading microorganisms. be able to.
(2) Since the treated water contains the degrading microorganisms, the wastewater can be treated without repeatedly increasing the concentration of the degrading microorganisms in the aeration tank by using this repeatedly. It is possible to provide a sewage treatment apparatus with low operating costs and excellent cost performance.
(3) By returning the treated water to the upstream part of the aeration tank using the treated water reflux part, the water level in the upstream part of the aeration tank rises, so that a natural water flow is created so as to average the water level in the aeration tank. Since it is formed, it is not necessary to arrange a means for forming a water flow in the aeration tank, and it is possible to provide a sewage treatment apparatus capable of reducing the facility load.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a main part of a sewage treatment apparatus according to a first embodiment.
FIG. 2 is a schematic cross-sectional view of a main part taken along line AA of FIG.
FIG. 3 is a schematic cross-sectional view of a main part along line BB in FIG. 1;
[Explanation of symbols]
1 Sewage treatment equipment
2 Sewage storage tank
3 First aeration tank
3a, 3b partition plate
4a, 4b Porous body holding unit
5a, 5b porous body
6 First upstream regulating aeration tank
7 First midstream aeration tank
8 First downstream aeration tank
9 Second aeration tank
9a Partition plate
9b Porous body holding part
9c porous body
10 Second upstream aeration tank
11 2nd downstream aeration tank
12 treatment water tank
13 Concentration and decomposition tank
14 Storage tank communication section
14a, 15a, 15c, 16b pump
15 Treated water reflux section
15b Aeration tank reflux section
16 Disassembly tank communication section
16a Suspended solids collection unit
17a, 17b, 17c, 17d, 22a, 22b, 22c, 22d Air diffuser
18,23 Aeration pipe
19 Compressor
20 Aeration tank communication section
21 Treatment tank connection
