JP3697334B2 - Sewage treatment equipment - Google Patents

Description

さらに、図１３および図１４において２次処理水５中の水質、特にＳＳ、色度、臭気等を除去する場合には、図１４のように、砂ろ過２０とオゾン反応槽２２との組み合わせでオゾン処理して、上記水質を良好にした高度処理水２３が得られる。しかしながら、このような２次処理水のオゾン処理方法では、２次処理水５中の残存するＣＯＤ、特に難分解性ＣＯＤは除去することはできなかった。
【００１１】
本発明はこのような点を考慮してなされたものであり、下水中のＣＯＤ、Ｎ、Ｐ等の汚泥物を効果的に除去することができる下水処理設備を提供することを目的とする。
【００１２】
【課題を解決するための手段】
本発明の特徴は、下水中の浮遊性物質を固液分離する第１沈殿池と、空気供給手段を有し、曝気反応を行なって有機物を分解除去する反応タンクと、余剰汚泥の一部を沈殿分離する第２沈殿池とを備え、第１沈殿池に回転式の撹拌装置を設置し、反応タンクと第１沈殿池との間に、ポンプを有し反応タンク内の下水を第１沈殿池へ戻す戻り管を設置し、第１沈殿池の流入側に流量計を設置し、この流量計のＰＶ値に基づいて前記撹拌装置の回転速度を制御することを特徴とする下水処理設備である。
【００１５】
本発明の特徴によれば、第１沈殿池に撹拌装置を設けたことにより、第１沈殿池内で下水を嫌気処理することができる。
【００１８】
【発明の実施の形態】
第１の実施の形態
以下、図面を参照して本発明の第１の実施の形態について説明する。
【００１９】
まず本発明の基本原理について以下説明する。
【００２０】
（１）第１沈殿池の沈殿機能を停止させて、第１沈殿池を反応タンクとして機能させれば、
（ａ）反応タンクの容積が増加することによる負荷の低減、（ｂ）既存の反応タンクを硝化槽あるいは無酸素槽−硝化槽に使用できることによる硝化反応、脱窒反応、Ｐ除去反応の効率化が可能となる。
【００２１】
（２）第１沈殿池あるいは下水処理場内・場外ポンプ井あるいは下水管をオゾン反応タンクとして機能させれば、下水中の難分解性ＣＯＤ成分を易分解性ＣＯＤ成分に変換し、その後、従来の反応タンクで易分解性ＣＯＤ成分を処理できるので、従来に比べて下水中のＣＯＤが低減することが可能となる。
【００２２】
次に図１により具体的構成について述べる。図１に示すように、下水処理設備は下水管２０から流入する下水１中の浮遊物質を固液分離する第１沈殿池３１と、第１沈殿池３１に流入管１１を介して接続されるとともに曝気反応を行なって有機物を分解除去する反応タンク３と、反応タンク３に流入管１２を介して接続されるとともに余剰汚泥の一部を沈殿分離する第２沈殿池４とを備えている。
【００２３】
第１沈殿池３１には散気管３２が設けられ、この散気管３２はブロア３４に空気管３３を介して接続されている。また第１沈殿池３１には、流出管１４を介してポンプ６が接続されている。
【００２４】
さらに反応タンク３には散気管１８ａが設けられ、この散気管１８ａはブロア９に空気管１８を介して接続されている。また第２沈殿池４には、流出管１６，１７を介してポンプ８が接続され、さらに流出管１６にはポンプ７を有する流出管１５が接続されている。
【００２５】
図１において、下水管２０内の下水中の汚泥物質であるＣＯＤ、ＢＯＤは、第１沈殿池３１内で散気管３２からの空気により好気処理されて、下水の上澄み液は次の反応タンク３へ供給される。上澄み液は、次に反応タンク３内で散気管１８ａからの空気により好気的に処理され、第２沈殿池４へ流入して高度処理水３５として流出管１３から放流される。
【００２６】
この間、第１沈殿池３１内の汚泥はポンプ６によって排出され、第２沈殿池４内の余剰汚泥の一部はポンプ８により系外へ排出され、余剰汚泥の残りはポンプ７により反応タンク３に戻される。
【００２７】
本実施例の形態によれば、散気管３２により第１沈殿池３１内の下水１中の汚泥物質、特にＣＯＤを効率的に除去することができる。
【００２８】
なお、図１において第２沈殿池４の底部から第１沈殿池３１の上流側にポンプと配管からなる返送汚泥手段を設置することにより、第２沈殿池４に余剰汚泥を返送してもよい。この返送汚泥手段は、既存の流出管１５から第１の沈殿池３１へ分岐した管によって構成してもよく、またポンプの代わりにエアリフト管を用いてもよい。
第２の実施の形態
次に図２により本発明の第２の実施の形態について説明する。図２に示す第２の実施の形態は第１沈殿池３１に散気管３２を設ける代わりに撹拌モータ３７で回転する撹拌機３６を設けたものであり、他は図１に示す第２の実施の形態と略同一である。
【００２９】
図２において、図１に示す第１の実施の形態と同一部分には同一符号を付して詳細な説明は省略する。
【００３０】
図２に示すように、第１沈殿池３１において流入する下水１中の汚泥物質であるＢＯＤ、ＣＯＤは、この第１沈殿池３１内で、撹拌モータ３７により駆動する撹拌翼３６によって撹拌され、このようにして汚泥物質が嫌気処理される。嫌気処理された水は反応タンク３に供給され、ここで散気管１８ａからの空気により好気処理される。その後、上澄み液は第２沈殿池４へ流入し、高度処理水３５として第２沈殿池４から流出管１３を経て放流される。
【００３１】
本実施の形態によれば、撹拌機３６の動作のみで第１沈殿池３１内を撹拌して第１沈殿池３１を嫌気状態に維持でき、容易に嫌気処理することができる。
【００３２】
なお撹拌翼３６を用いることなく、第１沈殿池３１内の底部に水中ポンプを設置して、水中ポンプの駆動により、第１沈殿池３１内を撹拌してもよい。
第３の実施の形態
次に図３により本発明の第３の実施の形態について説明する。図３に示す第３の実施の形態は反応タンク３と第１沈殿池３１との間にポンプ３８を有する戻り管３９を設けたものであり、他は図２に示す第２実施の形態と略同一である。図３において、図２に示す第２の実施の形態と同一部分には同一符号を付して詳細な説明を省略する。
【００３３】
図３において、反応タンク３内で下水１中のＣＯＤが好気除去されると同時に、下水１中のＮが硝化される。硝化液は、ポンプ３８を駆動することによって、戻り管３９を介して第１沈殿池３１内の上流に返送循環される。返送された硝化液は、第１沈殿池３１内の脱窒細菌により、下水１中の有機物を水素供与体として脱窒反応し、窒素ガスまで変換される。
【００３４】
反応タンク３および第１沈殿池３１による硝化・脱窒反応により下水１中のＮが除去され、その水は第２沈殿池４を経て高度処理水３５として放流される。
【００３５】
本実施の形態によれば、返送手段として、第１沈殿池３１と反応タンク３との間に、ポンプ３８を有する戻り管３９を配設したことにより、反応タンク３で十分硝化反応が進んだ硝化液を第１沈殿池３１へ返送することができる。また、ポンプ３８という平易な運転であるので、返送が容易となる。
【００３６】
なお戻り管３９の設置場所は反応タンク３の下流側に設けることが好ましいが、反応タンク３のいずれの箇所に接続してもよい。また、戻り管３９を流出管１２から分岐してもよく、かつ第１沈殿池４からも分岐してもよい。また、ポンプ３８の代わりにエアリフト方式の循環返送を採用してもよい。
第４の実施の形態
次に図４により本発明の第４の実施の形態について説明する。
【００３７】
図４に示す第４の実施の形態は反応タンク４０の内部に仕切板４１を配設し、この仕切板４１の前段に撹拌モータ４２を有する追加撹拌翼４３を設け、また、仕切板４１の後段部分の底部に散気管４４を設け、この散気管４４を空気管４５を介してブロア４６に連結したものである。他は図２に示す第２の実施の形態と略同一である。図４において、図２に示す第２の実施の形態と同一部分には同一符号を付して詳細な説明は省略する。
【００３８】
図４において、第１沈殿池３１は嫌気槽として機能する。また、反応タンク４０の前段部分は無酸素槽として、反応タンク４０の後段部分は好気槽として機能する。このように第１沈殿池３１と反応タンク４０により嫌気無酸素好気法（Ａ₂ Ｏ法）を達成することができ、下水１中の有機物のみならず、ＮとＰが同時に除去される。また、反応タンク４０の後段で十分硝化反応が進んだ硝化液は、ポンプ３８を有する戻り管３９によって反応タンク４０の前段に戻される。
【００３９】
本実施の形態によれば、返送手段としてポンプ３８を用い、撹拌手段として撹拌モータ４２を用いたので、簡易な運転操作で、各々返送手段および撹拌手段を動作することが可能となる。
【００４０】
なお、返送手段および撹拌手段は図４に示すものに限定されることはなく、また仕切板４１は必ずしも設置しなくてもよい。
第５の実施の形態
次に図５により、本発明の第５の実施の形態について説明する。
【００４１】
図５に示す第５の実施の形態は、第１沈殿池３１の底部に、散気管５０を設け、この散気管５０に流入管５１を介してオゾン発生器５２を接続したものである。また、第１沈殿池３１の最上部には流出管５３が接続されている。その他は図１に示す第１の実施の形態と略同一である。図５において、図１に示す第１の実施の形態と同一部分には同一符号を付して詳細な説明は省略する。
【００４２】
図５において第１沈殿池３１内の下水１中の難分解性ＣＯＤ成分は、オゾン発生器５２からのオゾンによって第１沈殿池３１内でオゾン処理されて易分解性ＣＯＤ成分に変換される。易分解性ＣＯＤ成分はＢＯＤ成分と等しいので、このＢＯＤ増加分は次ステップの反応タンク３内で好気処理される。このように、第１沈殿池３１内に流入する下水１中の難分解性ＣＯＤ成分が除去されるので、第１沈殿池３１内の下水１中のＣＯＤが高効率で除去される。
【００４３】
本実施の形態によれば、オゾン発生器５２で発生したオゾンを第１沈殿池３１内に供給して難分解性ＣＯＤ成分を易分解性ＣＯＤ成分とするので、ＣＯＤを高効率に除去することができる。
【００４４】
なお、図５では、オゾン発生器５２のオゾンガスを第１沈殿池３１のみに供給したが、オゾンガスを反応タンク３や第２沈殿池４あるいはそれ以外の次ステップのラインに供給してもよい。
第６の実施の形態
次に図６により本発明の第６の実施の形態について説明する。
【００４５】
図６に示すように、下水処理設備はポンプ５５が設置された場内ポンプ井５４を備え、場内ポンプ井５４内にはさらに散気管５６が設置されている。また散気管５６は空気管５８を介してブロア５７に接続されている。
【００４６】
場内ポンプ井５４に流入する下水５３中の汚泥物質は、ブロア５７から供給される空気によって好気処理され、浄化された水は第１沈殿池３１へ流入する下水１として水処理系へ供給される。
【００４７】
本実施の形態によれば、場内ポンプ井５４内にブロア５７に接続された散気管５６を配設したので、場内ポンプ井５４内部の曝気が容易である。
【００４８】
なお、図６のように新たにブロア５７を配設することなく、他のブロアから配管を取り回すことも可能である。また、場内ポンプ井５４のみならず、場外ポンプ井や下水管を直接、曝気してもよい。
第７の実施の形態
次に図７により本発明の第７の実施の形態について説明する。
【００４９】
図７に示すように、下水処理設備はポンプ５５が設置された場内ポンプ井５４を備え、場内ポンプ井５４内には散気管５６が設置されている。また散気管５６はオゾン管６１を介してオゾン発生器６０に接続されている。
【００５０】
図７において場内ポンプ井５４内に流入する下水５３中の汚泥物質、特に難分解性成分は、このポンプ井５４でオゾン発生器６０から送られるオゾンによってオゾン処理されて、易分解性ＣＯＤ成分に変換される。
【００５１】
本実施の形態によれば、場内ポンプ井５４内にオゾン発生器６０に接続された散気管５６を配設したので、場内ポンプ井５４内部のオゾン曝気が容易である。
【００５２】
なお、図７のように新たにオゾン発生器６０を配設しなくても、他のオゾン発生器から配管を取り回すことも可能である。また、場内ポンプ井５４のみならず、場外ポンプ井や下水管を直接、オゾン曝気することも可能である。
第８の実施の形態
次に図８により本発明の第８の実施の形態について説明する。
【００５３】
図８に示すように、下水処理設備は散気管１８ａが設置された反応タンク３を備え、散気管１８ａには空気管１８を介してブロア９が接続されている。また反応タンク３への流入管１１に流量計７０が取付けられており、流量計７０は比率一定制御回路７１および風量一定制御回路７２を介してブロア９に伝送路７３，７４，７５により接続されている。
【００５４】
図８において、比率一定制御回路７１と風量一定制御回路７２により流量計７０のＰＶ値に比例させて、ブロア９の風量を調節することができる。
【００５５】
本実施の形態によれば、流量計７０を反応タンク３の流入直前に配したので、反応タンク３に直接影響を及ぼす流量を正確に計測でき、制御の安定性を向上させることができる。
【００５６】
なお、流量計７０の設置場所は流入管１１に限定されることなく、その流入管１１よりも前段に配置してもよい。
第９の実施の形態
次に図９により本発明の第９の実施の形態について説明する。
【００５７】
図９に示す第９の実施の形態は、反応タンク３内のＤＯ計８０を設置するとともに、このＤＯ計８０をＤＯ一定制御回路８１および風量一定制御回路７２を介してブロア９に伝送路８２，８３，７５により接続したものである。他は図８に示す第８の実施の形態と略同一である。
【００５８】
図９において、反応タンク３内の流出口直前にＤＯ計８０を設置するとともにＤＯ計８０のＰＶ値が目標値ＳＶ値になるように、ＤＯ一定制御回路８１中のＰＩ調節機能を用いて、風量のＭＶ値の制御を行なう。
【００５９】
本実施の形態によれば、ＤＯ計８０を反応タンク３の流出直前に配したので、反応タンク３の流れ方向の影響を受けないで、反応タンク３のＤＯ値を正確に計測でき、制御の安定性が向上する。
【００６０】
なお、ＤＯ計８０の設置場所は反応タンク３の流出直前に限定されない。反応タンク３の液絡部に設置してもよく、また制御方式としては、ＰＩに限定されず、Ｐ動作のみやＰＩＤ動作も使用できる。
第１０の実施の形態
次に図１０により本発明の第１０の実施の形態について説明する。
【００６１】
図１０に示すように、下水処理設備に撹拌モータ３７によって駆動する撹拌槽３６が設置された第１沈殿池３１を備え、第１沈殿池３１の流入側に流量計８５が設置されている。流量計８５は比率一定制御回路８６および速度一定制御回路８７を介して伝送路８８，８９，９０により撹拌モータ３７に接続されている。
【００６２】
図１０において流量計８５のＰＶ値に比例して、比率一定制御回路８６および速度一定制御回路８７により撹拌モータ３７の回転速度を制御することができる。この場合、流量計８５を第１沈殿池３１の流入側に設けたので、第１沈殿池３１に直接影響を及ぼす流量を正確に計測でき、制御の安定性が向上する。また、速度一定制御回路８７を用いているので、第１沈殿池３１の撹拌状態のきめの細かい制御ができる。
【００６３】
なお、流量計８５の設置場所は第１沈殿池３１の流入側に限定されない。それよりもさらに前段に配設することも可能である。また、制御方式も速度一定制御回路だけでなく、撹拌モータ３７のＯＮ−ＯＦＦ制御も使用できる。
第１１の実施の形態
次に図１１により本発明の第１１の実施の形態について説明する。
【００６４】
図１１に示すように、下水処理設備は第１沈殿池３１と、ブロア９に空気管１８を介して接続された散気管１８ａを有する反応タンク３とを備え、反応タンク３と第１沈殿池３１との間にポンプ３８を有する戻り管３９が配設されている。第１沈殿池３１の流入側に流量計８５が設置され、流量計８５は比率一定制御回路９１および流量一定制御回路９２を介して伝送路９３，９４，９５によるポンプ３８に接続されている。
【００６５】
図１１において流量計８５のＰＶ値に比例して比率一定制御回路９１および流量一定制御回路９２によりポンプ３８の流量を制御することができる。この場合、流量計８５を第１沈殿池３１の流入側に配したので、第１沈殿池３１に直接影響を及ぼす流量を正確に計測でき、制御の安定性が向上する。
【００６６】
なお、流量計８５の設置場所は第１沈殿池３１の流入側に限定されない。それよりもさらに前段に配設してもよい。
第１２の実施の形態
次に図１２により本発明の第１２の実施の形態について説明する。
【００６７】
図１２に示すように、下水処理設備は散気管５６が設置された場内ポンプ井５４を備え、散気管５６にはオゾン管６１を介してオゾン発生器６０が接続されている。また、場内ポンプ井５４の流入側には流量計１００が設置されており、この流量計１００は比率一定制御回路１０１およびオゾン注入量一定制御回路１０２を介して伝送路１０３，１０４，１０５によりオゾン発生器６０に接続されている。
【００６８】
図１２に示すように、流量計１００のＰＶ値に比例して、比率一定制御回路１０１およびオゾン注入量一定制御回路１０２によりオゾン発生器６０の注入量を制御することができる。
【００６９】
本実施の形態によれば、流量計１００を場内ポンプ井５４の流入側に配設したので、場内ポンプ井５４に直接影響を及ぼす流量を正確に計測でき、制御の安定性が向上する。
【００７０】
なお、流量計１００の設置場所は場内ポンプ井５４の流入直前に限定されない。それよりさらに前段の下水管に配設してもよい。
【００７１】
【発明の効果】
以上のように本発明によれば、下水中の汚泥物質を効果的に除去することができる。
【図面の簡単な説明】
【図１】本発明による下水処理装置の第１の実施の形態を示す構成図。
【図２】本発明による下水処理装置の第２の実施の形態を示す構成図。
【図３】本発明による下水処理装置の第３の実施の形態を示す構成図。
【図４】本発明による下水処理装置の第４の実施の形態を示す構成図。
【図５】本発明による下水処理装置の第５の実施の形態を示す構成図。
【図６】本発明による下水処理装置の第６の実施の形態を示す構成図。
【図７】本発明による下水処理装置の第７の実施の形態を示す構成図。
【図８】本発明による下水処理装置の第８の実施の形態を示す構成図。
【図９】本発明による下水処理装置の第９の実施の形態を示す構成図。
【図１０】本発明による下水処理装置の第１０の実施の形態を示す構成図。
【図１１】本発明による下水処理装置の第１１の実施の形態を示す構成図。
【図１２】本発明による下水処理装置の第１２の実施の形態を示す構成図。
【図１３】従来の下水処理装置を示す構成図。
【図１４】従来の下水処理装置を示す構成図。
【符号の説明】
１ 流入下水
３，４０ 反応タンク
４ 第２沈殿池
９，４６，５７ ブロア
３１ 第１沈殿池
３６，４３ 撹拌翼
３７，４２ 撹拌モータ
３８ ポンプ
５２ オゾン発生器
５４ 場内ポンプ井
７０，８５，１００ 流量計
７１，８６，９１，１０１ 比率一定制御回路
７２ 風量一定制御回路
８０ ＤＯ計
８１ ＤＯ一定制御回路
８７ 速度一定制御回路
９２ 流量一定制御回路
１０２ オゾン注入量一定制御回路[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sewage treatment facility capable of removing sludge substances such as COD, N, and P in sewage in a sewage treatment plant, an off-site pumping station, or a sewage pipe.
[0002]
[Prior art]
A conventional sewage treatment facility is shown in FIGS.
[0003]
FIG. 13 is a diagram showing a process of the standard activated sludge method. In FIG. 13, the suspended substance (SS) of the sewage 1 in the inflow sewage pipe 10 is separated and settled in the first settling basin 2, and the supernatant is supplied into the reaction tank 3 through the inflow pipe 11. In the reaction tank 3, microorganisms decompose and remove supernatant sludge substances, particularly organic substances, with the air aerated from the blower 8. A part of the surplus sludge that is a microorganism group that has grown at this time flows into the second sedimentation basin 4 through the inflow pipe 12, and is separated by sedimentation in the second sedimentation basin 4. The surplus sludge is then discharged out of the water treatment system through the outflow pipes 16 and 17 by driving the pump 8 in a timely manner, and is sludge treated. Further, the remainder of the excess sludge is returned to the inflow side of the reaction tank 3 through the outflow pipe 15 by driving the pump 7.
[0004]
The sludge in the first sedimentation basin 2 is discharged to the outside by the pump 6 through the outflow pipe 14, and the supernatant liquid in the second sedimentation basin 4 is discharged as the secondary treated water 5 through the outflow pipe 13. Is done.
[0005]
FIG. 14 shows an advanced treatment process of sewage by sand filtration and ozone treatment. SS in the secondary treated water 5 in the inflow pipe 24 is removed by the sand filter 20 and sent to the ozone reactor 22 through the inflow pipe 25. Next, the secondary treated water 5 is subjected to ozone treatment in an ozone reaction tank 22 in which ozone gas from the ozone generator 21 is aerated, and thus highly treated water 23 having improved water quality is obtained.
[0006]
The advanced treated water 23 is discharged through the outflow pipe 26. The ozone gas in the ozone generator 21 flows into the ozone reaction tank 22 through the inflow pipe 27 and is exhausted as exhaust ozone 29 from the exhaust pipe 28.
[0007]
[Problems to be solved by the invention]
By the way, in the process of the activated sludge method shown in FIG.
(1) The concentration of sludge substance in the sewage 1 flowing into the first sedimentation basin becomes high (increased concentration load),
(2) The flow rate of the sewage 1 flowing into the first sedimentation basin increases (increase in flow rate load),
(3) The water temperature drops in winter,
(4) Inhibitors are mixed into the sewage 1 flowing into the first sedimentation basin,
(5) Insufficient process operation management
(6) Due to a decrease in the activity of microorganisms in the reaction tank 3,
There is a problem that the water quality in the secondary treated water 5, particularly the organic substance removal characteristics such as COD and BOD deteriorate.
[0008]
Furthermore, in the reaction tank 3, even if BOD can be removed, there is a problem that a part of the COD, particularly a hardly decomposable COD component, cannot be removed, and the COD in the secondary treated water 5 deteriorates.
[0009]
Also in other conventional processes, such as the process shown in Table 1 for removing N and P, nitrification activity in the aerobic part or denitrification in the anaerobic part due to the causes (1) to (6) above. There is a problem that the activity of microbial groups that remove P, such as P accumulating bacteria, decreases the water quality in the treated water, especially the nutrient removal characteristics such as N and P, due to the decrease in activity. did.
[0010]
[Table 1]

Further, in FIG. 13 and FIG. 14, when removing the water quality in the secondary treated water 5, particularly SS, chromaticity, odor, etc., as shown in FIG. 14, the combination of the sand filtration 20 and the ozone reaction tank 22 is used. Ozone treatment is performed to obtain highly treated water 23 with improved water quality. However, in such an ozone treatment method of secondary treated water, the remaining COD in the secondary treated water 5, in particular, hardly decomposable COD could not be removed.
[0011]
The present invention has been made in consideration of such points, and an object thereof is to provide a sewage treatment facility capable of effectively removing sludge such as COD, N, and P in sewage.
[0012]
[Means for Solving the Problems]
A feature of the present invention is that a first sedimentation basin for solid-liquid separation of suspended substances in sewage, an air supply means, a reaction tank for decomposing and removing organic substances by aeration reaction, and a part of excess sludge are removed. A second settling basin that separates and separates the sedimentation, a rotary stirring device is installed in the first settling basin, and a sewage in the reaction tank is pumped between the reaction tank and the first settling basin. A sewage treatment facility characterized in that a return pipe for returning to the pond is installed, a flow meter is installed on the inflow side of the first settling basin, and the rotational speed of the agitator is controlled based on the PV value of the flow meter. is there.
[0015]
According to the feature of the present invention, by providing a stirring device in the first sedimentation basin, sewage can be anaerobically treated in the first sedimentation basin.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
[0019]
First, the basic principle of the present invention will be described below.
[0020]
(1) If the sedimentation function of the first sedimentation basin is stopped and the first sedimentation basin functions as a reaction tank,
(A) Reduction of load due to increase in volume of reaction tank, (b) Efficiency of nitrification reaction, denitrification reaction and P removal reaction by using existing reaction tank as nitrification tank or oxygen-free tank-nitrification tank Is possible.
[0021]
(2) If the first sedimentation basin or the pump well or sewage pipe in the sewage treatment plant functions as an ozone reaction tank, the refractory COD component in the sewage is converted into a readily degradable COD component, Since the easily decomposable COD component can be treated in the reaction tank, COD in the sewage can be reduced as compared with the conventional case.
[0022]
Next, a specific configuration will be described with reference to FIG. As shown in FIG. 1, a sewage treatment facility is connected to a first sedimentation basin 31 for solid-liquid separation of suspended solids in sewage 1 flowing from a sewage pipe 20 and to the first sedimentation basin 31 via an inflow pipe 11. In addition, a reaction tank 3 that performs aeration reaction to decompose and remove organic substances, and a second sedimentation tank 4 that is connected to the reaction tank 3 via an inflow pipe 12 and separates and separates a part of excess sludge are provided.
[0023]
The first settling basin 31 is provided with an air diffuser 32, and the air diffuser 32 is connected to the blower 34 via an air tube 33. A pump 6 is connected to the first settling basin 31 via the outflow pipe 14.
[0024]
Further, the reaction tank 3 is provided with an air diffusion pipe 18 a, and the air diffusion pipe 18 a is connected to the blower 9 through the air pipe 18. In addition, a pump 8 is connected to the second sedimentation tank 4 via outflow pipes 16 and 17, and an outflow pipe 15 having a pump 7 is connected to the outflow pipe 16.
[0025]
In FIG. 1, COD and BOD which are sludge substances in the sewage in the sewage pipe 20 are aerobically treated by the air from the diffuser pipe 32 in the first sedimentation basin 31, and the supernatant of the sewage is used in the next reaction tank. 3 is supplied. The supernatant liquid is then aerobically processed in the reaction tank 3 by the air from the diffuser pipe 18 a, flows into the second sedimentation basin 4, and is discharged from the outflow pipe 13 as the advanced treated water 35.
[0026]
During this time, the sludge in the first settling basin 31 is discharged by the pump 6, a part of the excess sludge in the second settling basin 4 is discharged out of the system by the pump 8, and the remaining surplus sludge is discharged by the pump 7 to the reaction tank 3. Returned to
[0027]
According to this embodiment, sludge substances, particularly COD, in the sewage 1 in the first settling basin 31 can be efficiently removed by the air diffuser 32.
[0028]
In FIG. 1, surplus sludge may be returned to the second sedimentation tank 4 by installing a return sludge means including a pump and piping from the bottom of the second sedimentation tank 4 to the upstream side of the first sedimentation tank 31. . This return sludge means may be constituted by a pipe branched from the existing outflow pipe 15 to the first settling basin 31, and an air lift pipe may be used instead of the pump.
Second embodiment Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment shown in FIG. 2, a stirrer 36 that is rotated by a stirring motor 37 is provided in place of the aeration pipe 32 in the first settling basin 31, and the other is the second embodiment shown in FIG. The form is substantially the same.
[0029]
In FIG. 2, the same parts as those of the first embodiment shown in FIG.
[0030]
As shown in FIG. 2, BOD and COD, which are sludge substances in the sewage 1 flowing into the first sedimentation basin 31, are stirred in the first sedimentation basin 31 by a stirring blade 36 driven by a stirring motor 37, In this way, the sludge substance is anaerobically treated. The anaerobically treated water is supplied to the reaction tank 3 where it is aerobically treated with air from the air diffuser 18a. Thereafter, the supernatant liquid flows into the second sedimentation basin 4 and is discharged from the second sedimentation basin 4 through the outflow pipe 13 as the advanced treated water 35.
[0031]
According to the present embodiment, the first settling basin 31 can be stirred by only the operation of the stirrer 36 to maintain the first settling basin 31 in an anaerobic state, and anaerobic treatment can be easily performed.
[0032]
Instead of using the stirring blade 36, a submersible pump may be installed at the bottom of the first sedimentation basin 31, and the interior of the first sedimentation basin 31 may be agitated by driving the submersible pump.
Third embodiment Next, a third embodiment of the present invention will be described with reference to FIG. The third embodiment shown in FIG. 3 is provided with a return pipe 39 having a pump 38 between the reaction tank 3 and the first settling basin 31, and the others are the same as the second embodiment shown in FIG. It is almost the same. In FIG. 3, the same parts as those of the second embodiment shown in FIG.
[0033]
In FIG. 3, COD in the sewage 1 is removed aerobically in the reaction tank 3, and N in the sewage 1 is nitrified. The nitrating liquid is returned and circulated upstream in the first sedimentation basin 31 via the return pipe 39 by driving the pump 38. The returned nitrification solution is denitrified by denitrifying bacteria in the first sedimentation basin 31 using the organic matter in the sewage 1 as a hydrogen donor, and converted to nitrogen gas.
[0034]
N in the sewage 1 is removed by the nitrification / denitrification reaction by the reaction tank 3 and the first sedimentation basin 31, and the water is discharged as the advanced treated water 35 through the second sedimentation basin 4.
[0035]
According to the present embodiment, as the return means, the return pipe 39 having the pump 38 is disposed between the first sedimentation tank 31 and the reaction tank 3, so that the nitrification reaction has sufficiently progressed in the reaction tank 3. The nitrification liquid can be returned to the first sedimentation basin 31. Further, since the pump 38 is a simple operation, it can be returned easily.
[0036]
The return pipe 39 is preferably installed on the downstream side of the reaction tank 3, but may be connected to any part of the reaction tank 3. Further, the return pipe 39 may be branched from the outflow pipe 12 and may also be branched from the first sedimentation tank 4. Further, instead of the pump 38, an air lift type circulation return may be employed.
Fourth embodiment Next, a fourth embodiment of the present invention will be described with reference to FIG.
[0037]
In the fourth embodiment shown in FIG. 4, a partition plate 41 is provided inside the reaction tank 40, an additional stirring blade 43 having a stirring motor 42 is provided in the previous stage of the partition plate 41, and A diffuser tube 44 is provided at the bottom of the rear portion, and the diffuser tube 44 is connected to a blower 46 via an air tube 45. The rest is substantially the same as the second embodiment shown in FIG. In FIG. 4, the same parts as those of the second embodiment shown in FIG.
[0038]
In FIG. 4, the 1st sedimentation basin 31 functions as an anaerobic tank. Further, the front part of the reaction tank 40 functions as an oxygen-free tank, and the rear part of the reaction tank 40 functions as an aerobic tank. Thus, the anaerobic anaerobic anaerobic method (A ₂ O method) can be achieved by the first sedimentation tank 31 and the reaction tank 40, and not only organic substances in the sewage 1 but also N and P are removed simultaneously. Further, the nitrification liquid that has sufficiently undergone the nitrification reaction at the subsequent stage of the reaction tank 40 is returned to the previous stage of the reaction tank 40 by a return pipe 39 having a pump 38.
[0039]
According to the present embodiment, since the pump 38 is used as the return means and the agitation motor 42 is used as the agitation means, it is possible to operate the return means and the agitation means with a simple operation.
[0040]
The return means and the agitation means are not limited to those shown in FIG. 4, and the partition plate 41 does not necessarily have to be installed.
Fifth embodiment Next, a fifth embodiment of the present invention will be described with reference to FIG.
[0041]
In the fifth embodiment shown in FIG. 5, a diffuser pipe 50 is provided at the bottom of the first sedimentation tank 31, and an ozone generator 52 is connected to the diffuser pipe 50 via an inflow pipe 51. An outflow pipe 53 is connected to the uppermost part of the first sedimentation tank 31. Others are substantially the same as those of the first embodiment shown in FIG. In FIG. 5, the same parts as those of the first embodiment shown in FIG.
[0042]
In FIG. 5, the hardly decomposable COD component in the sewage 1 in the first sedimentation basin 31 is ozone-treated in the first sedimentation basin 31 by ozone from the ozone generator 52 and converted into an easily decomposable COD component. Since the readily decomposable COD component is equal to the BOD component, this BOD increase is aerobically processed in the reaction tank 3 in the next step. Thus, since the hardly decomposable COD component in the sewage 1 flowing into the first sedimentation basin 31 is removed, the COD in the sewage 1 in the first sedimentation basin 31 is removed with high efficiency.
[0043]
According to the present embodiment, the ozone generated by the ozone generator 52 is supplied into the first sedimentation basin 31 to convert the hardly decomposable COD component into an easily decomposable COD component, so that COD is removed with high efficiency. Can do.
[0044]
In FIG. 5, the ozone gas from the ozone generator 52 is supplied only to the first sedimentation basin 31, but the ozone gas may be supplied to the reaction tank 3, the second sedimentation basin 4, or the other next line.
Sixth Embodiment Next, a sixth embodiment of the present invention will be described with reference to FIG.
[0045]
As shown in FIG. 6, the sewage treatment facility includes an on-site pump well 54 in which a pump 55 is installed, and an aeration pipe 56 is further installed in the on-site pump well 54. The air diffuser 56 is connected to a blower 57 via an air tube 58.
[0046]
The sludge substance in the sewage 53 flowing into the on-site pump well 54 is aerobically treated by the air supplied from the blower 57, and the purified water is supplied to the water treatment system as sewage 1 flowing into the first sedimentation basin 31. The
[0047]
According to the present embodiment, since the diffuser pipe 56 connected to the blower 57 is arranged in the in-field pump well 54, aeration inside the in-field pump well 54 is easy.
[0048]
In addition, it is also possible to route piping from another blower without newly providing the blower 57 as shown in FIG. Further, not only the in-house pump well 54 but also the off-site pump well and the sewage pipe may be directly aerated.
7. Seventh embodiment Next, a seventh embodiment of the present invention will be described with reference to FIG.
[0049]
As shown in FIG. 7, the sewage treatment facility includes an on-site pump well 54 in which a pump 55 is installed, and an aeration pipe 56 is installed in the on-site pump well 54. The air diffuser 56 is connected to an ozone generator 60 through an ozone pipe 61.
[0050]
In FIG. 7, sludge substances in the sewage 53 flowing into the on-site pump well 54, in particular, hardly decomposable components, are ozone-treated by ozone sent from the ozone generator 60 in the pump well 54 to be easily decomposable COD components. Converted.
[0051]
According to the present embodiment, since the diffuser pipe 56 connected to the ozone generator 60 is disposed in the in-house pump well 54, ozone aeration inside the in-house pump well 54 is easy.
[0052]
In addition, even if it does not arrange | position the ozone generator 60 newly like FIG. 7, it is also possible to route piping from another ozone generator. Further, not only the in-house pump well 54 but also the off-site pump well and the sewage pipe can be directly aerated with ozone.
Eighth embodiment Next, an eighth embodiment of the present invention will be described with reference to FIG.
[0053]
As shown in FIG. 8, the sewage treatment facility includes a reaction tank 3 in which a diffuser pipe 18 a is installed, and a blower 9 is connected to the diffuser pipe 18 a via an air pipe 18. A flow meter 70 is attached to the inflow pipe 11 to the reaction tank 3, and the flow meter 70 is connected to the blower 9 by transmission lines 73, 74, 75 through a constant ratio control circuit 71 and a constant air volume control circuit 72. ing.
[0054]
In FIG. 8, the air volume of the blower 9 can be adjusted in proportion to the PV value of the flow meter 70 by the constant ratio control circuit 71 and the constant air volume control circuit 72.
[0055]
According to the present embodiment, since the flow meter 70 is arranged immediately before the inflow of the reaction tank 3, the flow rate directly affecting the reaction tank 3 can be accurately measured, and the stability of control can be improved.
[0056]
In addition, the installation place of the flowmeter 70 is not limited to the inflow pipe 11, and may be disposed in front of the inflow pipe 11.
Ninth embodiment Next, a ninth embodiment of the present invention will be described with reference to FIG.
[0057]
In the ninth embodiment shown in FIG. 9, a DO meter 80 in the reaction tank 3 is installed, and the DO meter 80 is connected to the blower 9 via the DO constant control circuit 81 and the air volume constant control circuit 72. , 83, 75. The rest is substantially the same as the eighth embodiment shown in FIG.
[0058]
In FIG. 9, using the PI adjustment function in the DO constant control circuit 81 so that the DO meter 80 is installed just before the outlet in the reaction tank 3 and the PV value of the DO meter 80 becomes the target SV value, The air volume MV value is controlled.
[0059]
According to this embodiment, since the DO meter 80 is arranged immediately before the reaction tank 3 flows out, the DO value of the reaction tank 3 can be accurately measured without being affected by the flow direction of the reaction tank 3, and the control Stability is improved.
[0060]
The installation location of the DO meter 80 is not limited to immediately before the reaction tank 3 flows out. You may install in the liquid junction part of the reaction tank 3, and it is not limited to PI as a control system, Only P operation | movement or PID operation | movement can also be used.
Tenth embodiment Next, a tenth embodiment of the present invention will be described with reference to FIG.
[0061]
As shown in FIG. 10, a sewage treatment facility includes a first settling basin 31 in which a stirring tank 36 driven by a stirring motor 37 is installed, and a flow meter 85 is installed on the inflow side of the first settling basin 31. The flow meter 85 is connected to the agitation motor 37 by transmission paths 88, 89, 90 through a constant ratio control circuit 86 and a constant speed control circuit 87.
[0062]
In FIG. 10, the rotational speed of the stirring motor 37 can be controlled by the constant ratio control circuit 86 and the constant speed control circuit 87 in proportion to the PV value of the flow meter 85. In this case, since the flow meter 85 is provided on the inflow side of the first settling basin 31, the flow rate directly affecting the first settling basin 31 can be accurately measured, and the stability of control is improved. Further, since the constant speed control circuit 87 is used, fine control of the stirring state of the first settling basin 31 can be performed.
[0063]
The installation place of the flow meter 85 is not limited to the inflow side of the first sedimentation basin 31. It is also possible to dispose further upstream. Further, the control method can use not only the constant speed control circuit but also the ON / OFF control of the stirring motor 37.
Eleventh embodiment Next, an eleventh embodiment of the present invention will be described with reference to FIG.
[0064]
As shown in FIG. 11, the sewage treatment facility includes a first sedimentation tank 31 and a reaction tank 3 having a diffuser pipe 18 a connected to the blower 9 via an air pipe 18. The reaction tank 3 and the first sedimentation tank A return pipe 39 having a pump 38 is disposed between the pipe 31 and the pipe 31. A flow meter 85 is installed on the inflow side of the first sedimentation basin 31, and the flow meter 85 is connected to the pump 38 by the transmission lines 93, 94, 95 via the constant ratio control circuit 91 and the constant flow control circuit 92.
[0065]
In FIG. 11, the constant flow rate control circuit 91 and the constant flow rate control circuit 92 can control the flow rate of the pump 38 in proportion to the PV value of the flow meter 85. In this case, since the flow meter 85 is arranged on the inflow side of the first sedimentation basin 31, the flow rate directly affecting the first sedimentation basin 31 can be accurately measured, and the stability of control is improved.
[0066]
The installation place of the flow meter 85 is not limited to the inflow side of the first sedimentation basin 31. You may arrange | position in the front | former stage further than it.
Twelfth embodiment Next, a twelfth embodiment of the present invention will be described with reference to FIG.
[0067]
As shown in FIG. 12, the sewage treatment facility includes an in-situ pump well 54 in which a diffuser pipe 56 is installed, and an ozone generator 60 is connected to the diffuser pipe 56 via an ozone pipe 61. In addition, a flow meter 100 is installed on the inflow side of the in-house pump well 54. The flow meter 100 is supplied with ozone through transmission lines 103, 104, and 105 via a constant ratio control circuit 101 and a constant ozone injection amount control circuit 102. Connected to the generator 60.
[0068]
As shown in FIG. 12, the injection amount of the ozone generator 60 can be controlled by the constant ratio control circuit 101 and the ozone injection amount constant control circuit 102 in proportion to the PV value of the flow meter 100.
[0069]
According to the present embodiment, since the flow meter 100 is disposed on the inflow side of the in-house pump well 54, the flow rate directly affecting the in-house pump well 54 can be accurately measured, and control stability is improved.
[0070]
The installation location of the flow meter 100 is not limited to immediately before the inflow of the on-site pump well 54. Further, it may be disposed in the sewage pipe in the previous stage.
[0071]
【The invention's effect】
As described above, according to the present invention, sludge substances in sewage can be effectively removed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment of a sewage treatment apparatus according to the present invention.
FIG. 2 is a configuration diagram showing a second embodiment of a sewage treatment apparatus according to the present invention.
FIG. 3 is a configuration diagram showing a third embodiment of a sewage treatment apparatus according to the present invention.
FIG. 4 is a configuration diagram showing a fourth embodiment of a sewage treatment apparatus according to the present invention.
FIG. 5 is a configuration diagram showing a fifth embodiment of a sewage treatment apparatus according to the present invention.
FIG. 6 is a configuration diagram showing a sixth embodiment of a sewage treatment apparatus according to the present invention.
FIG. 7 is a configuration diagram showing a seventh embodiment of a sewage treatment apparatus according to the present invention.
FIG. 8 is a configuration diagram showing an eighth embodiment of a sewage treatment apparatus according to the present invention.
FIG. 9 is a configuration diagram showing a ninth embodiment of a sewage treatment apparatus according to the present invention.
FIG. 10 is a configuration diagram showing a tenth embodiment of a sewage treatment apparatus according to the present invention.
FIG. 11 is a configuration diagram showing an eleventh embodiment of a sewage treatment apparatus according to the present invention.
FIG. 12 is a configuration diagram showing a twelfth embodiment of a sewage treatment apparatus according to the present invention.
FIG. 13 is a configuration diagram showing a conventional sewage treatment apparatus.
FIG. 14 is a configuration diagram showing a conventional sewage treatment apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inflow sewage 3,40 Reaction tank 4 2nd sedimentation tank 9,46,57 Blower 31 1st sedimentation tank 36,43 Stirring blade 37,42 Stirring motor 38 Pump 52 Ozone generator 54 In-situ pump well 70,85,100 Flow rate Total 71, 86, 91, 101 Constant ratio control circuit 72 Air flow constant control circuit 80 DO meter 81 DO constant control circuit 87 Constant speed control circuit 92 Constant flow rate control circuit 102 Constant ozone injection amount control circuit

Claims (2)

A first sedimentation basin for solid-liquid separation of suspended substances in sewage,
A reaction tank having an air supply means and performing aeration reaction to decompose and remove organic substances;
A second settling basin that settles and separates a portion of the excess sludge,
Installed a rotary stirring device in the 1st sedimentation basin
A return pipe is installed between the reaction tank and the first sedimentation basin to return the sewage in the reaction tank to the first sedimentation basin with a pump.
A sewage treatment facility, wherein a flow meter is installed on the inflow side of the first settling basin, and the rotational speed of the stirring device is controlled based on the PV value of the flow meter. A first sedimentation basin for solid-liquid separation of suspended substances in sewage,
  A reaction tank having an air supply means and performing aeration reaction to decompose and remove organic substances;
  A second settling basin that settles and separates a portion of the excess sludge,
Installed a rotary stirring device in the 1st sedimentation basin
A return pipe is installed between the reaction tank and the first sedimentation basin to return the sewage in the reaction tank to the first sedimentation basin with a pump.
A sewage treatment facility, wherein a flow meter is installed on the inflow side of the first settling basin, and the rotational speed of the agitator is controlled in proportion to the PV value of the flow meter.

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