JP3769093B2

JP3769093B2 - Advanced wastewater treatment device and advanced treatment method

Info

Publication number: JP3769093B2
Application number: JP07827197A
Authority: JP
Inventors: 望安永; 誠司古川; 好孝河相; 淳二廣辻; 繁樹中山
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1997-03-28
Filing date: 1997-03-28
Publication date: 2006-04-19
Anticipated expiration: 2017-03-28
Also published as: JPH10272479A

Description

【０００１】
【発明の属する技術分野】
本発明は、排水の高度処理装置および高度処理方法に関するものであり、さらに詳しくは本発明は、通常の排水のオゾン処理の際に少量の過酸化水素を添加して処理する過酸化水素−オゾン併用排水処理方法において、ＴＯＣ除去効率を低下させずに効率的且つ経済的に排水を処理する装置ならびにこれを用いた処理方法に関するものである。
【０００２】
【従来の技術】
過酸化水素−オゾン併用の排水処理方法は、添加した過酸化水素とオゾンとを反応させて、過酸化水素やオゾンよりも酸化分解力が非常に強いヒドロキシラジカル（ＯＨラジカル）を効率的に生成させて、これを使ってオゾンのみでは分解できない難分解性物質をも除去する方法である。
【０００３】
従来のこの種の処理装置の一例を図１６に示す。図１６において、１はオゾン反応器、２はオゾン発生装置、３は被処理水供給ポンプ、４は過酸化水素添加ポンプ、５はオゾン反応器１内にとりつけられた散気装置、６は排オゾン分解装置、７は過酸化水素貯留タンクであり、ａ〜ｅは配管である。
【０００４】
次に動作について説明する。
汚濁有機物を含む被処理水は、被処理水供給ポンプ３により、ポンプ配管ａを介してオゾン反応器１に供給される。また、過酸化水素は過酸化水素貯留タンク７から過酸化水素添加ポンプ４により、配管ｂを介してオゾン反応器１に供給され、被処理水に添加される。さらに、オゾン発生装置２では、空気または酸素、あるいは酸素富化ガスを原料としてオゾン化ガスを生成し、配管ｄを介して散気装置５に供給する。散気装置５では、オゾン化ガスを微細気泡としてオゾン反応器１に供給することにより被処理水中にオゾンを溶解させる。オゾン反応器１では溶解したオゾンと添加された過酸化水素とが反応してＯＨラジカルが生成し、これが被処理水中に含有する汚濁有機物を分解除去して、水を高度処理する。
オゾン反応器１内の被処理水に溶解しきれなかったオゾンは、排オゾンとして、配管ｅを介してオゾン分解触媒が充填されている排オゾン処理装置６に導かれ、酸素に無害分解化され、大気へ放出される。
【０００５】
【発明が解決しようとする課題】
従来の過酸化水素添加オゾン処理装置は以上のような構成であったので、例えば図１７に有機物濃度の１指標である全有機炭素濃度（ＴＯＣ濃度、Total Organic Carbon）とオゾン消費量との関係の一例を示すように、単位有機性炭素量を分解除去するのに必要なオゾン量（ΔＯ₃／ΔＴＯＣ）は１７８（g−Ｏ₃／g−ＴＯＣ）程度と多量のオゾンが必要であり、処理条件の最適化はされておらず、汚濁有機物の分解除去効率が悪くて経済的でなく実用性に乏しいという問題があった。また、接触段数を複数にして多段接触させる場合も処理条件の最適化はされておらず、経済的でなく実用性に乏しかった。
なお図１７は図１６と同型式の容積４Ｌ、水深１．４ｍの反応装置を用いて、ＴＯＣ濃度７mg／Ｌの下水処理水の凝集ろ過水を被処理水として発生オゾン濃度２０g／Ｎm³、供給オゾン化ガス流量１Ｌ／分、滞留時間５〜２０分、過酸化水素添加濃度５〜２０mg／Ｌの条件で得られた実験結果である。
【０００６】
本発明は上記のような問題点を解消するためになされたもので、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を低減し、汚濁有機物の分解除去効率が良好で、経済的で実用的な過酸化水素−オゾン併用タイプの排水の高度処理装置およびこれを用いた排水の高度処理方法を提供することを目的とするものである。
【０００７】
【課題を解決するための手段】
本発明者らは上述の課題を解決すべく鋭意研究を行った結果、本発明を完成することができた。
すなわち本発明は、被処理水に過酸化水素とオゾンとを添加、混合して被処理水中の有機物を分解除去する装置において、該装置は、被処理水の配管と、前記配管に過酸化水素を注入する手段と、過酸化水素が添加された被処理水の前記配管にオゾン化ガスを少なくとも二箇所以上で分割注入するための手段と、前記配管の後に未溶解のオゾン化ガスと処理水とを分離して、未溶解のオゾン化ガスを無害分解化して放出する手段と、を備えたことを特徴とする排水の高度処理装置を提供するものである。
【０００８】
また本発明は、被処理水の配管の断面が円形である前記の排水の高度処理装置を提供するものである。
【０００９】
さらに本発明は、オゾン化ガスの導入箇所が少なくとも４箇所以上である前記の排水の高度処理装置を提供するものである。
【００１０】
さらにまた本発明は、被処理水に過酸化水素とオゾンとを添加、混合して被処理水中の有機物を分解除去する方法において、配管に被処理水を通水し、前記配管を流れる被処理水に過酸化水素を注入し、続いて過酸化水素を含み且つ前記配管を流れる被処理水に、少なくとも二箇所以上でオゾン化ガスを分割注入し、前記配管後に未溶解のオゾン化ガスと処理水とを分離して、未溶解のオゾン化ガスを無害分解化して放出することを特徴とする排水の高度処理方法を提供するものである。
【００１１】
また本発明は、被処理水が加圧され、配管内で被処理水中の有機物の分解が進む前記の排水の高度処理方法を提供するものである。
【００１２】
さらに本発明は、オゾン化ガスが、あらかじめ定められた量で配分されて分割注入される前記の排水の高度処理方法を提供するものである。
【００１３】
さらにまた本発明は、オゾン化ガスが、均等配分された注入量で分割注入される前記の排水の高度処理方法を提供するものである。
【００１４】
また本発明は、被処理水にオゾン化ガスが分割注入されるよりも前に、被処理水に対して予定されている過酸化水素注入量の全量を注入する前記の排水の高度処理方法を提供するものである。
【００１５】
さらに本発明は、過酸化水素を含む被処理水とオゾン化ガスとの反応時間が少なくとも８秒以上に設定される前記の排水の高度処理方法を提供するものである。
【００１６】
【発明の実施の形態】
本発明者らは、ＴＯＣの除去効率が、オゾンの溶解効率に密接な関連があることを見いだした。本発明によれば、あらかじめ所定量の過酸化水素を添加した被処理水の配管に、あらかじめ定めた間隔で少なくとも二箇所以上でオゾン化ガスを導入することにより、配管内の圧力損失を小さくすることができる。その結果、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）が低減され、且つ汚濁有機物の分解除去効率が良好となる。さらに装置全体も小型化され実用上有利である。
【００１７】
本発明者らは、動力学モデルに基づく計算機シミュレーションを繰り返し、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を低減し、汚濁有機物の分解除去効率が良好となる過酸化水素とオゾンとを併用した排水の高度処理方法について研究してきた。その結果、いくつかの重要な現象を発見し、本発明に想到した。
【００１８】
図１に本発明の装置の一実施態様を示す。また表１にシミュレーション条件を示す。モデルは反応器にはオゾン化ガス注入口が４点あり、オゾン化ガス注入後の被処理水の流れは完全混合とした。被処理水のＴＯＣは５．７mgＣ／Ｌ、オゾン化ガス総流量は４．８Ｌ／分とする。動力学モデルは文献“Reactions of Hydroxyl Radicals with Hydrogen Peroxide at Ambient and Elevated Temparatures”（J．Phys．Chem.，86，55-68，1982）に記載のモデルを簡略化したものを用いた。図２に簡略化したモデルの反応スキームおよび反応式を示す。
【００１９】
【表１】

【００２０】
次に図１の装置の動作について説明する。
汚濁有機物を含む被処理水は、被処理水供給ポンプ３により、ポンプ配管ａを介して被処理水の流路からなるオゾン反応器１に供給される。流路は、その断面が円形であれば、オゾンの反応効率が高まり、被処理水中の有機物の分解が進むために望ましい。また、過酸化水素の導入手段は、過酸化水素添加ポンプ４であり、過酸化水素貯留タンク７から過酸化水素が配管ｂを介してオゾン反応器１に導入され、被処理水に添加される。さらに、オゾン発生装置２は空気または酸素、あるいは酸素富化ガスを原料としてオゾン化ガスを生成し、生成されたオゾン化ガスは配管ｄを介し分岐され、オゾン化ガス流量計９により所定量の流量となるように調節されてオゾン化ガス注入口５に供給される。例えば２点注入の場合は、最上流側の流量計および上流から３個目の流量計を所定量に合わせ、その他の流量計は閉じる。４点注入の場合は全流量計を所定量に合わせる。オゾン化ガス注入口５では、オゾン化ガスを被処理水に加えられた圧力を利用して微細気泡としてオゾン反応器１に供給することにより、被処理水中にオゾンを溶解させるのが好ましい。また、オゾン化ガス注入口５は、汚濁有機物が十分に分解されるに十分な被処理水−オゾン化ガスの接触がなされるような間隔でもって設けられるのがよい。オゾン反応器１では溶解したオゾンと添加された過酸化水素とが反応してＯＨラジカルが生成し、これが被処理水中に含有する汚濁有機物を分解除去して、水を高度処理する。
オゾン反応器１内の被処理水に溶解しきれなかったオゾンは、気液分離槽８で排オゾンとして、配管ｅを介してオゾン分解触媒が充填されている排オゾン処理装置６に導かれ、酸素に無害分解化され、大気へ放出される。
【００２１】
以下、本発明の実施の形態を図面を参照しながらさらに説明する。
実施の形態１．
図３は、過酸化水素注入率４０mg／Ｌ、注入オゾン濃度１２０mg／Ｌとしたときの１点注入、２点注入のときの処理水のＴＯＣの変化である。１点注入の場合は滞留時間が０秒の時に、２点注入の場合は滞留時間が０秒と１６秒の時にオゾン化ガスを注入しており、注入したときにＴＯＣが大きく減少している。これよりオゾン化ガスの注入点数を２点に増やすことでＴＯＣの値が小さくなり、処理水質が改善される。
また１点注入、２点注入のどちらの場合でもオゾン化ガス注入後約８秒でほぼ定常状態になっており、少なくとも８秒以上の反応時間で処理が完全に完了するといえる。
【００２２】
図４は、図３と同条件での単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）の結果である。１点注入の場合は、ΔＯ₃/ΔＴＯＣが３４．４、２点注入の場合は２７．６と改善されている。従って図３および図４よりオゾン化ガスの注入点数を２点に増やすことでＴＯＣ値および単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）が小さくなり、処理水質および処理効率が改善される。これはオゾンの供給を２度に分けたことにより水中に溶解するオゾンの急激な上昇を抑えることによってＯＨラジカルの無効消費が抑えられたためであるといえる。
【００２３】
図５は、それぞれ注入オゾン濃度６０mg／Ｌ、オゾン注入点数４点、注入オゾン化ガスの流量は一段目の注入口で１．９２Ｌ／分、以下流れ方向に順に１．４４Ｌ／分、０．９６Ｌ／分、０．４８Ｌ／分とする傾斜配分および各段の注入オゾン化ガス流量を１．２Ｌ／分ずつとする均等配分して注入したときの過酸化水素注入率を１０、２２、４０mg／Ｌと変化させたときの処理水のＴＯＣの変化である。均等配分と傾斜配分のそれぞれの過酸化水素の注入率について比較すると、若干ではあるが均等配分のほうがＴＯＣ濃度が低い結果となっている。
【００２４】
図６は、それぞれ注入オゾン濃度６０mg／Ｌ、オゾン注入点数４点、注入オゾン化ガスの流量は一段目の注入口で１．９２Ｌ／分、以下流れ方向に順に１．４４Ｌ／分、０．９６Ｌ／分、０．４８Ｌ／分とする傾斜配分および各段の注入オゾン化ガス流量を１．２Ｌ／分ずつとする均等配分して注入したときの過酸化水素注入率を１０、２２、４０mg／Ｌと変化させたときの単位有機性炭素量を分解除去するために必要なオゾン量（トＯ₃／トＴＯＣ）の変化である。均等配分と傾斜配分のそれぞれの過酸化水素の注入率について比較すると、図５同様若干ではあるが均等配分のほうが単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／トＴＯＣ）が低い結果となっている。以上図５および図６より注入オゾン化ガス流量を均等配分したほうが傾斜配分した場合よりも処理水のＴＯＣも低く、単位有機性炭素量を分解除去するために必要なオゾン量（トＯ₃／トＴＯＣ）も小さく、処理水質がよくかつ効率よく処理できる。
【００２５】
図７は、それぞれ注入オゾン濃度１２０mg／Ｌ、オゾン注入点数４点、注入オゾンの導入量は均等に分配すなわち１．２Ｌ／分ずつ注入して、過酸化水素注入率４０．０mg／Ｌ、過酸化水素の全量をあらかじめ被処理水に添加した最初注入の場合およびオゾンの注入を各段の注入口で行う分割注入の場合の処理水のＴＯＣの変化である。あらかじめ全量の過酸化水素を注入したほうが処理水のＴＯＣが低くなっており、処理水質がよくなっている。
【００２６】
図８は、それぞれ注入オゾン濃度１２０mg／Ｌ、オゾン注入点数４点、注入オゾンの導入量は均等に分配すなわち１．２Ｌ／分ずつ注入して、過酸化水素注入率４０．０mg／Ｌ、過酸化水素の全量をあらかじめ被処理水に添加した最初注入の場合およびオゾンの注入を各段の注入口で行う分割注入の場合の被処理水の単位有機性炭素量を分解除去するために必要なオゾン量（トＯ₃／トＴＯＣ）の変化である。図７同様あらかじめ全量の過酸化水素を注入したほうが被処理水の単位有機性炭素量を分解除去するために必要なオゾン量（トＯ₃／トＴＯＣ）が低くなり、効率よく処理ができる。
【００２７】
図９は、それぞれ注入オゾン濃度１２０mg／Ｌ、オゾン注入点数４点、注入オゾン化ガスの導入量は均等配分すなわち１．２Ｌ／分ずつ注入して、過酸化水素注入率４０．０mg／Ｌ、過酸化水素の全量をあらかじめ被処理水に添加した最初注入の場合およびオゾンの注入を各段の注入口で行う分割注入の場合の処理水の過酸化水素の変化である。これより消費された過酸化水素量は最初注入のほうが多く、効率的に過酸化水素が消費されている。以上図７、図８、図９よりあらかじめ全量の過酸化水素を注入したほうが処理水のＴＯＣおよび単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／トＴＯＣ）が低くなって効率よく処理ができ、過酸化水素も効率よく利用される。
【００２８】
図１０および図１１は、注入オゾン濃度６０mg／Ｌ、オゾン注入点数４点、注入オゾン化ガスの流量は均等配分、過酸化水素はあらかじめ全量を注入した場合のオゾン化ガス注入点数とＴＯＣおよび単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）との関係である。ＴＯＣおよび単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）は、注入点数が増加すると減少していく傾向が見られるが、注入点数が４点以降は減少の度合いがすなわち曲線の傾きの絶対値が小さくなる。
【００２９】
以上の結果より発明者らは次のような考察を導いた。すなわち、（１）被処理水の流路にオゾン化ガス注入口を設けることにより、汚濁有機物の分解除去効率が良好となり、過酸化水素とオゾンとを併用した排水の高度処理方法では反応が非常に早く完了し、装置をコンパクトにすることができる。（２）配管上のオゾン化ガス注入口の数が処理水質および処理効率に関係があり、オゾン化ガスの導入量は均等に配分したほうが処理水質および処理効率がよい。（３）過酸化水素の注入点は、あらかじめ予定されている過酸化水素投入量の全量を最初に注入したほうが処理水質および処理効率がよく、実装置を考えた場合に分岐点や流量計等を設置することを考えると分注するよりも有利である。（４)オゾン化ガスの注入点数が４点以上となると、処理水のＴＯＣおよび単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）は変化が小さくなる。
【００３０】
実施の形態２．
次にオゾンの注入点数をパラメータとしたときの結果について示す。
図１２および図１３は、過酸化水素を注入率４０．０mg／Ｌであらかじめ被処理水に注入し、オゾンの導入量を均等に配分したときの被処理水のＴＯＣおよび単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を示すものである。横軸は注入オゾン濃度である。これより注入オゾン濃度が大きいほど処理水のＴＯＣは低くなるが、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）は大きくなることが分かる。オゾン化ガスの注入点数を増やすことで処理水のＴＯＣも低く、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）も小さくできる。
【００３１】
図１４および図１５は、それぞれオゾン導入量を注入オゾン濃度６０．０mg／Ｌで均等に配分して注入したときの処理水のＴＯＣ、および、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を示すものである。最適過酸化水素注入率が存在することが分かり、今回のシミュレーション条件では約４０mg／Ｌである。これ以上過酸化水素注入率を増加しても処理水のＴＯＣも、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）も変化はない。
これらの結果より発明者らは次のような考察を導いた。すなわち、（１）被処理水の水質を向上するには、注入オゾン濃度を大きくすればよいが、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）は大きくなるため、注入オゾン濃度と単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）が操作条件として重要である。（２）過酸化水素注入率には最適値が存在する。
【００３２】
【発明の効果】
以上のように請求項１の発明によれば、被処理水に過酸化水素とオゾンとを添加、混合して被処理水中の有機物を分解除去する装置において、該装置は、被処理水の配管と、前記配管に過酸化水素を注入する手段と、過酸化水素が添加された被処理水の前記配管にオゾン化ガスを少なくとも二箇所以上で分割注入するための手段と、前記配管の後に未溶解のオゾン化ガスと処理水とを分離して、未溶解のオゾン化ガスを無害分解化して放出する手段と、を備えているため、流路内の圧力損失を小さくすることができる。そのため、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を低減し、汚濁有機物の分解除去効率が良好で、経済的で実用的な過酸化水素−オゾン化ガス併用による排水の処理方法による水の高度処理を実現できる。また、装置自体もコンパクトにすることができ実用上有利である。
【００３３】
また、請求項２の発明によれば、被処理水の配管の断面が円形であるため、オゾンの溶解効率が高まるために有利である。
【００３４】
また、請求項３の発明によれば、オゾン化ガスの導入箇所を少なくとも４点以上とすることで必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を増加させずに効率よく処理できる。
【００３５】
また、請求項４の発明によれば、被処理水に過酸化水素とオゾンとを添加、混合して被処理水中の有機物を分解除去する方法において、配管に被処理水を通水し、前記配管を流れる被処理水に過酸化水素を注入し、続いて過酸化水素を含み且つ前記配管を流れる被処理水に、少なくとも二箇所以上でオゾン化ガスを分割注入し、前記配管後に未溶解のオゾン化ガスと処理水とを分離して、未溶解のオゾン化ガスを無害分解化して放出するため、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を低減し、汚濁有機物の分解除去効率が良好で、経済的で実用的な過酸化水素−オゾン併用タイプの排水の高度処理方法を提供することができる。
【００３６】
また、請求項５の発明によれば、被処理水が加圧されて配管を流れるために、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／トＴＯＣ）を低減し、汚濁有機物の分解除去効率が良好で、経済的で実用的な過酸化水素併用オゾン処理方法による水の高度処理を実現できる。
【００３７】
また、請求項６の発明によれば、オゾン化ガスをあらかじめ定めた割合で分配して分割注入されることにより、単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ_３／ΔＴＯＣ）を低減し、汚濁有機物の分解除去効率が良好で、経済的で実用的な過酸化水素併用オゾン処理方法による水の高度処理を実現できる。
【００３８】
また、請求項７の発明によれば、オゾン化ガスを均等配分された注入量で分割注入するので単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ_３／ΔＴＯＣ）を増加させずに、一層効率よく処理できる。
【００３９】
また、請求項８の発明によれば、予め被処理水に対して予定されている過酸化水素注入量の全量を注入することにより、必要なオゾン量（ΔＯ_３／ΔＴＯＣ）を増加させずに一層効率よく処理できる。
【００４０】
また、請求項９の発明によれば、過酸化水素を含む被処理水とオゾン化ガスとの反応時間が少なくとも８秒以上に設定されるため、必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を増加させずに一層効率よく処理できる。
【図面の簡単な説明】
【図１】本発明の装置の一実施態様を説明するための図である。
【図２】この発明のシミュレーションに用いた反応のモデルと反応式である。
【図３】過酸化水素注入率４０mg／Ｌ、注入オゾン濃度を１２０mg／Ｌ、１点注入、２点注入のときの処理水のＴＯＣの変化を示す図である。
【図４】過酸化水素注入率４０mg／Ｌ、注入オゾン濃度１２０mg／Ｌで注入したときの１点注入および２点注入の単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を示す図である。
【図５】過酸化水素注入率を１０、２２、４０mg／Ｌ、注入オゾン濃度６０mg／Ｌでオゾン注入点数が４点の場合の注入ガス流量が均等分配と傾斜分配のときのＴＯＣを示す処理特性図である。
【図６】過酸化水素注入率を１０、２２、４０mg／Ｌ、注入オゾン濃度６０mg／Ｌでオゾン注入点数が４点の場合の注入ガス流量が均等分配と傾斜分配のときの単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）を示す処理特性図である。
【図７】過酸化水素の注入方法が最初注入および分割注入の場合のオゾン注入点数４点、オゾン化ガス均等分配におけるＴＯＣの変化を示す処理特性図である。
【図８】過酸化水素の注入方法が最初注入および分割注入の場合のオゾン注入点数４点、オゾン化ガス均等分配における単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）の変化を示す処理特性図である。
【図９】過酸化水素の注入方法が最初注入および分割注入の場合のオゾン注入点数４点、オゾン化ガス均等分配における過酸化水素の変化を示す処理特性図である。
【図１０】過酸化水素注入率４０mg／Ｌ、注入オゾン濃度１２０mg／Ｌで注入したときの注入点数に対するＴＯＣの変化を示す処理特性図である。
【図１１】過酸化水素注入率４０mg／Ｌ、注入オゾン濃度１２０mg／Ｌで注入したときの注入点数に対する単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）の変化を示す処理特性図である。
【図１２】過酸化水素注入率が４０mg／Ｌの場合の注入オゾン濃度に対するＴＯＣの変化を示す処理特性図である。
【図１３】過酸化水素注入率が４０mg／Ｌの場合の注入オゾン濃度に対する単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）の変化を示す処理特性図である。
【図１４】注入オゾン濃度が６０mg／Ｌの場合の過酸化水素注入率に対するＴＯＣの変化を示す処理特性図である。
【図１５】注入オゾン濃度が４０mg／Ｌの場合の過酸化水素注入率に対する単位有機性炭素量を分解除去するために必要なオゾン量（ΔＯ₃／ΔＴＯＣ）の変化を示す処理特性図である。
【図１６】従来の過酸化水素併用オゾン処理装置の構成図である。
【図１７】従来の過酸化水素併用オゾン処理装置によるＴＯＣ濃度とオゾン消費量の関係を示す処理特性図である。
【符号の説明】
１オゾン反応器、２オゾン発生装置、３被処理水供給ポンプ、４過酸化水素添加ポンプ、５オゾン化ガス注入口、６排オゾン分解装置、７過酸化水素貯留タンク、８気液分離槽、９オゾン化ガス流量計、ａ，ｂ被処理水配管、ｃ処理水配管、ｄ，ｅオゾン化ガス配管。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an advanced wastewater treatment apparatus and advanced treatment method, and more particularly, the present invention relates to hydrogen peroxide-ozone that is treated by adding a small amount of hydrogen peroxide during normal wastewater ozone treatment. The combined wastewater treatment method relates to an apparatus for treating wastewater efficiently and economically without reducing the TOC removal efficiency, and a treatment method using the same.
[0002]
[Prior art]
The wastewater treatment method combined with hydrogen peroxide and ozone reacts the added hydrogen peroxide with ozone to efficiently generate hydroxy radicals (OH radicals), which are much stronger in oxidative degradation than hydrogen peroxide and ozone. In this way, this method is also used to remove difficult-to-decompose substances that cannot be decomposed by ozone alone.
[0003]
An example of this type of conventional processing apparatus is shown in FIG. In FIG. 16, 1 is an ozone reactor, 2 is an ozone generator, 3 is a treated water supply pump, 4 is a hydrogen peroxide addition pump, 5 is an air diffuser installed in the

ozone reactor

1, and 6 is an exhaust device. An ozonolysis apparatus, 7 is a hydrogen peroxide storage tank, and a to e are pipes.
[0004]
Next, the operation will be described.
To-be-treated water containing polluted organic substances is supplied to the ozone reactor 1 by the to-be-treated water supply pump 3 through the pump pipe a. Hydrogen peroxide is supplied from the hydrogen peroxide storage tank 7 to the ozone reactor 1 via the pipe b by the hydrogen peroxide addition pump 4 and added to the water to be treated. Further, the ozone generator 2 generates ozonized gas using air, oxygen, or oxygen-enriched gas as a raw material, and supplies it to the diffuser 5 via the pipe d. In the air diffuser 5, ozone is dissolved in the water to be treated by supplying ozonized gas as fine bubbles to the ozone reactor 1. In the ozone reactor 1, dissolved ozone and added hydrogen peroxide react to generate OH radicals, which decompose and remove pollutant organic substances contained in the water to be treated, thereby subjecting the water to advanced treatment.
The ozone that could not be completely dissolved in the water to be treated in the ozone reactor 1 is led as exhausted ozone to the exhausted ozone treatment device 6 filled with the ozone decomposition catalyst through the pipe e, and is harmlessly decomposed into oxygen. Released into the atmosphere.
[0005]
[Problems to be solved by the invention]
Since the conventional hydrogen peroxide-added ozone treatment apparatus has the above-described configuration, for example, FIG. 17 shows the relationship between the total organic carbon concentration (TOC concentration, Total Organic Carbon), which is one index of the organic matter concentration, and the ozone consumption. As shown in an example, the amount of ozone (ΔO ₃ / ΔTOC) required for decomposing and removing the unit organic carbon amount is about 178 (gO ₃ / g-TOC), and a large amount of ozone is required. The processing conditions have not been optimized, and there has been a problem that the efficiency of decomposition and removal of polluted organic substances is poor, which is not economical and practical. In addition, even when the number of contact stages is set to a plurality of levels, the processing conditions are not optimized, which is not economical and practical.
Note that FIG. 17 uses a reactor of the same type as FIG. 16 with a volume of 4 L and a water depth of 1.4 m, and the generated ozone concentration is 20 g / Nm ³ , using flocculated filtered water of sewage treated water with a TOC concentration of 7 mg / L as treated water It is the experimental result obtained on the conditions of supply ozonization gas flow rate 1L / min, residence time 5-20 minutes, and hydrogen peroxide addition density | concentration 5-20 mg / L.
[0006]
The present invention has been made to solve the above-described problems, and reduces the amount of ozone (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount, thereby decomposing and removing pollutant organic matter. It is an object of the present invention to provide an advanced treatment apparatus for wastewater of a combined hydrogen peroxide-ozone type that is favorable, economical, and practical, and an advanced wastewater treatment method using the same.
[0007]
[Means for Solving the Problems]
As a result of intensive studies aimed at solving the above-mentioned problems, the present inventors have completed the present invention.
That is, the present invention includes adding hydrogen peroxide and ozone to the water to be treated, in the apparatus for decomposing and removing organic substances in the water to be treated is mixed, the apparatus comprising a pipe of the water to be treated, hydrogen peroxide to said piping Means for injecting ozonized gas into the pipe to be treated to which hydrogen peroxide has been added at least at two or more locations, undissolved ozonized gas and treated water after the pipe And a means for decomposing and releasing undissolved ozonized gas harmlessly, and providing an advanced wastewater treatment device.
[0008]
The present invention also provides the above-described advanced wastewater treatment apparatus in which the pipe of the water to be treated has a circular cross section.
[0009]
Furthermore, the present invention provides the above-described advanced wastewater treatment apparatus in which ozonized gas introduction sites are at least four or more.
[0010]
Furthermore, the present invention is added to the hydrogen peroxide and ozone to the water to be treated and mixed to a method for removing the decomposition of organic matter in the water to be treated, and passed through the treatment water in the piping, be treated flowing through the pipe Hydrogen peroxide is injected into water, and then ozonized gas is dividedly injected into water to be treated that contains hydrogen peroxide and flows through the pipe at least at two or more locations, and is treated with undissolved ozonized gas after the pipe. The present invention provides an advanced wastewater treatment method characterized by separating water and decomposing and releasing undissolved ozonized gas harmlessly.
[0011]
The present invention also provides the above-described advanced wastewater treatment method in which the water to be treated is pressurized and the decomposition of organic substances in the water to be treated proceeds in the pipe .
[0012]
Furthermore, the present invention provides the above-described advanced wastewater treatment method in which ozonized gas is distributed in a predetermined amount and dividedly injected .
[0013]
Furthermore, the present invention provides the above-described advanced wastewater treatment method in which ozonized gas is dividedly injected at an evenly distributed injection amount .
[0014]
The present invention, before the ozonized gas is divided injected into the water to be treated, the advanced treatment method of the waste water injecting the entire amount of hydrogen peroxide injection rate, which is destined for the water to be treated It is to provide.
[0015]
Furthermore, the present invention provides the above-described advanced wastewater treatment method in which the reaction time between the water to be treated containing hydrogen peroxide and the ozonized gas is set to at least 8 seconds or more.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The present inventors have found that the removal efficiency of TOC is closely related to the dissolution efficiency of ozone. According to the present invention, the pressure loss in the pipe is reduced by introducing the ozonized gas into the pipe of the water to be treated to which a predetermined amount of hydrogen peroxide has been added in advance at at least two predetermined intervals. be able to. As a result, the amount of ozone (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount is reduced, and the efficiency of decomposing and removing polluted organic substances is improved. Furthermore, the entire apparatus is reduced in size and is practically advantageous.
[0017]
The present inventors have repeated computer simulation based on a kinetic model to reduce the amount of ozone (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon content, and the efficiency of decomposing and removing polluted organic matter is good. We have been studying advanced wastewater treatment methods using both hydrogen peroxide and ozone. As a result, several important phenomena were discovered and the present invention was conceived.
[0018]
FIG. 1 shows an embodiment of the apparatus of the present invention. Table 1 shows the simulation conditions. The model had four ozonized gas inlets in the reactor, and the flow of water to be treated after the ozonized gas injection was completely mixed. The TOC of water to be treated is 5.7 mgC / L, and the total flow of ozonized gas is 4.8 L / min. The kinetic model was a simplified version of the model described in the literature “Reactions of Hydroxyl Radicals with Hydrogen Peroxide at Ambient and Elevated Temparatures” (J. Phys. Chem., 86, 55-68, 1982). FIG. 2 shows a simplified model reaction scheme and reaction formula.
[0019]
[Table 1]

[0020]
Next, the operation of the apparatus shown in FIG. 1 will be described.
To-be-treated water containing polluted organic substances is supplied by the to-be-treated water supply pump 3 to the ozone reactor 1 composed of the flow path of to-be-treated water through the pump pipe a. If the cross section of the flow path is circular, ozone reaction efficiency is increased, and decomposition of organic substances in the water to be treated is desirable. The hydrogen peroxide introduction means is a hydrogen peroxide addition pump 4, and hydrogen peroxide is introduced from the hydrogen peroxide storage tank 7 into the ozone reactor 1 through the pipe b and added to the water to be treated. . Further, the ozone generator 2 generates ozonized gas using air, oxygen, or oxygen-enriched gas as a raw material, and the generated ozonized gas is branched through a pipe d. The flow rate is adjusted to be supplied to the ozonized gas inlet 5. For example, in the case of two-point injection, the uppermost flow meter and the third flow meter from the upstream are set to a predetermined amount, and the other flow meters are closed. In the case of four-point injection, adjust all flow meters to a predetermined amount. At the ozonized gas inlet 5, it is preferable to dissolve ozone in the water to be treated by supplying the ozonized gas to the ozone reactor 1 as fine bubbles using the pressure applied to the water to be treated. In addition, the ozonized gas inlet 5 is preferably provided at an interval such that sufficient contact between the water to be treated and the ozonized gas is achieved so that the polluted organic matter is sufficiently decomposed. In the ozone reactor 1, dissolved ozone and added hydrogen peroxide react to generate OH radicals, which decompose and remove pollutant organic substances contained in the water to be treated, thereby subjecting the water to advanced treatment.
The ozone that could not be completely dissolved in the water to be treated in the ozone reactor 1 is led as exhausted ozone in the gas-liquid separation tank 8 to the exhausted ozone treatment device 6 filled with the ozone decomposition catalyst via the pipe e. It is harmlessly decomposed into oxygen and released into the atmosphere.
[0021]
Hereinafter, embodiments of the present invention will be further described with reference to the drawings.
Embodiment 1 FIG.
FIG. 3 shows the change in the TOC of the treated water during one-point injection and two-point injection when the hydrogen peroxide injection rate is 40 mg / L and the injection ozone concentration is 120 mg / L. In the case of 1-point injection, the residence time is 0 seconds, and in the case of 2-point injection, the ozonized gas is injected when the residence time is 0 seconds and 16 seconds, and the TOC decreases greatly when injected. . From this, by increasing the number of ozonized gas injection points to two, the value of TOC is reduced and the quality of the treated water is improved.
In either case of one-point injection or two-point injection, the state is almost steady at about 8 seconds after the ozonized gas injection, and it can be said that the treatment is completely completed in a reaction time of at least 8 seconds or more.
[0022]
FIG. 4 shows the results of the ozone amount (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount under the same conditions as in FIG. In the case of one-point injection, ΔO ₃ / ΔTOC is improved to 34.4 and 27.6 in the case of two-point injection. Therefore, the ozone amount (ΔO ₃ / ΔTOC) required for decomposing and removing the TOC value and the unit organic carbon amount is reduced by increasing the number of ozonized gas injection points to 2 from FIG. 3 and FIG. And the processing efficiency is improved. This is because the ineffective consumption of OH radicals was suppressed by suppressing the rapid increase of ozone dissolved in water by dividing the supply of ozone twice.
[0023]
FIG. 5 shows an injection ozone concentration of 60 mg / L, an ozone injection point of 4 points, an injection ozonization gas flow rate of 1.92 L / min at the first-stage injection port, and 1.44 L / min. The hydrogen peroxide injection rate was 10, 22, and 40 mg when the injection was carried out with a gradient distribution of 96 L / min and 0.48 L / min and an even distribution with the injection ozonization gas flow rate at each stage being 1.2 L / min. This is the change in the TOC of the treated water when changed to / L. Comparing the hydrogen peroxide injection rates of the uniform distribution and the gradient distribution, the TOC concentration is lower in the uniform distribution although it is slightly.
[0024]
FIG. 6 shows an injection ozone concentration of 60 mg / L, an ozone injection point of 4 points, and an injection ozonization gas flow rate of 1.92 L / min at the first stage inlet, 1.44 L / min in the flow direction, and. The hydrogen peroxide injection rate was 10, 22, and 40 mg when the injection was carried out with a gradient distribution of 96 L / min and 0.48 L / min and an even distribution with the injection ozonization gas flow rate at each stage being 1.2 L / min. / L is the change in the amount of ozone (toO ₃ / toTOC) required to decompose and remove the unit organic carbon amount. Comparing the hydrogen peroxide injection rates of the uniform distribution and the inclined distribution, the amount of ozone (ΔO ₃ / to TOC) required for decomposing and removing the unit organic carbon amount is slightly smaller than that in FIG. ) Is low. 5 and 6, the TOC of the treated water is lower when the flow rate of the injected ozonized gas is evenly distributed than when the flow rate of the injected ozonized gas is evenly distributed, and the amount of ozone necessary for decomposing and removing the unit organic carbon amount (g / O ₃ / To TOC) is small, the quality of the treated water is good and the treatment can be performed efficiently.
[0025]
FIG. 7 shows an injection ozone concentration of 120 mg / L, an ozone injection point of 4 points, and an injection amount of injected ozone distributed evenly, that is, 1.2 L / min. This is a change in the TOC of treated water in the case of initial injection in which the entire amount of hydrogen oxide is added to the water to be treated in advance and in the case of divided injection in which ozone is injected at each stage inlet. If the total amount of hydrogen peroxide is injected in advance, the TOC of the treated water is lower and the quality of the treated water is improved.
[0026]
FIG. 8 shows an injection ozone concentration of 120 mg / L, an ozone injection point of 4 points, and an introduction amount of injected ozone of evenly distributed, that is, injection of 1.2 L / min, and a hydrogen peroxide injection rate of 40.0 mg / L. Necessary for decomposing and removing the unit organic carbon content of water to be treated in the case of the first injection in which the total amount of hydrogen oxide is added to the water to be treated in advance and in the case of divided injection in which ozone is injected at each stage inlet This is a change in the amount of ozone (to O ₃ / to TOC). As shown in FIG. 7, the total amount of hydrogen peroxide injected in advance reduces the ozone amount (to O ₃ / to TOC) required for decomposing and removing the unit organic carbon amount of the water to be treated, thereby enabling efficient treatment.
[0027]
FIG. 9 shows an injection ozone concentration of 120 mg / L, an ozone injection point of 4 points, and an injection amount of injected ozonized gas is equally distributed, that is, 1.2 L / min, and a hydrogen peroxide injection rate of 40.0 mg / L, This is a change in hydrogen peroxide in the treated water in the case of the first injection in which the total amount of hydrogen peroxide was previously added to the water to be treated and in the case of divided injection in which ozone is injected at each stage inlet. The amount of hydrogen peroxide consumed is larger in the first injection, and hydrogen peroxide is efficiently consumed. 7, 8, and 9, the amount of ozone (ΔO ₃ / toTOC) required for decomposing and removing the TOC and unit organic carbon content of the treated water is lower when the total amount of hydrogen peroxide is injected in advance. Can be processed efficiently, and hydrogen peroxide is also used efficiently.
[0028]
FIGS. 10 and 11 show the injection ozone concentration of 60 mg / L, the number of ozone injection points of 4, the flow rate of the injection ozonized gas is evenly distributed, the hydrogen peroxide is injected in advance, the number of ozonized gas injection points, the TOC, and the unit. This is the relationship with the amount of ozone (ΔO ₃ / ΔTOC) necessary for decomposing and removing the amount of organic carbon. The amount of ozone (ΔO ₃ / ΔTOC) required for decomposing and removing TOC and unit organic carbon content tends to decrease as the number of injection points increases, but the degree of decrease after 4 injection points. That is, the absolute value of the slope of the curve becomes small.
[0029]
From the above results, the inventors derived the following consideration. That is, (1) By providing an ozonized gas inlet in the flow path of the water to be treated, the decomposition and removal efficiency of polluted organic matter is improved, and the reaction is extremely effective in the advanced wastewater treatment method using both hydrogen peroxide and ozone. Can be completed quickly and the device can be made compact. (2) The number of ozonized gas inlets on the pipe is related to the treated water quality and the treatment efficiency, and the treatment water quality and the treatment efficiency are better when the amount of ozonized gas introduced is evenly distributed. (3) As for the injection point of hydrogen peroxide, the treatment water quality and treatment efficiency are better when the total amount of hydrogen peroxide input that is planned in advance is injected first. It is more advantageous than dispensing when considering the installation. (4) When the number of ozonized gas injection points is 4 or more, the amount of ozone (ΔO ₃ / ΔTOC) necessary for decomposing and removing the TOC and unit organic carbon content of the treated water becomes small.
[0030]
Embodiment 2. FIG.
Next, the results when the number of ozone injection points is used as a parameter will be shown.
12 and 13 show the TOC and unit organic carbon amount of water to be treated when hydrogen peroxide is injected into the water to be treated in advance at an injection rate of 40.0 mg / L and the amount of ozone introduced is evenly distributed. This shows the amount of ozone (ΔO ₃ / ΔTOC) required for decomposing and removing. The horizontal axis represents the injected ozone concentration. It can be seen from this that the TOC of the treated water decreases as the injected ozone concentration increases, but the amount of ozone (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount increases. By increasing the number of ozonized gas injection points, the TOC of the treated water is lowered, and the ozone amount (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount can be reduced.
[0031]
FIG. 14 and FIG. 15 respectively show the TOC of treated water and the unit organic carbon amount required for decomposing and removing when the ozone introduction amount is equally distributed at an injection ozone concentration of 60.0 mg / L. This indicates the amount of ozone (ΔO ₃ / ΔTOC). It can be seen that there is an optimal hydrogen peroxide injection rate, which is about 40 mg / L under the simulation conditions of this time. Even if the hydrogen peroxide injection rate is further increased, the TOC of the treated water and the ozone amount (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount are not changed.
From these results, the inventors derived the following consideration. That is, (1) In order to improve the quality of the water to be treated, the concentration of injected ozone may be increased, but the amount of ozone (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount is increased. Therefore, the ozone concentration (ΔO ₃ / ΔTOC) necessary for decomposing and removing the injected ozone concentration and the unit organic carbon amount is important as the operating condition. (2) There is an optimum value for the hydrogen peroxide injection rate.
[0032]
【The invention's effect】
As described above, according to the first aspect of the present invention, in the apparatus for adding and mixing hydrogen peroxide and ozone to the water to be treated and mixing and decomposing and removing the organic matter in the water to be treated, the apparatus comprises a pipe for the water to be treated. When the means for injecting hydrogen peroxide into the pipe, and means for dividing injected at the ozonized gas at least two or more places in the pipe of the water to be treated hydrogen peroxide is added, non after the pipe A means for separating the dissolved ozonized gas and the treated water and decomposing and releasing the undissolved ozonized gas harmlessly is provided, so that the pressure loss in the flow path can be reduced. Therefore, the amount of ozone (ΔO ₃ / ΔTOC) required for decomposing and removing unit organic carbon is reduced, and the decomposition and removal efficiency of polluted organic substances is good, economical and practical hydrogen peroxide-ozonized gas Advanced water treatment can be realized by the combined wastewater treatment method. Further, the apparatus itself can be made compact, which is practically advantageous.
[0033]
Further, according to the invention of claim 2, since the cross section of the pipe of the water to be treated is circular, it is advantageous because the ozone dissolution efficiency is increased.
[0034]
In addition, according to the invention of claim 3, it is possible to efficiently perform the treatment without increasing the necessary ozone amount (ΔO ₃ / ΔTOC) by setting the ozonized gas introduction site to at least four points or more.
[0035]
According to the invention of claim 4, in the method for adding and mixing hydrogen peroxide and ozone to the water to be treated to decompose and remove organic substances in the water to be treated, the water to be treated is passed through a pipe , Hydrogen peroxide was injected into the treatment water flowing in the pipe, followed by the water to be treated and include hydrogen peroxide flowing through the pipe, dividing injected ozonized gas in at least two or more places, undissolved after said pipe The ozone amount (ΔO ₃ / ΔTOC) required for decomposing and removing the unit organic carbon is reduced because the ozonized gas and treated water are separated and the undissolved ozonized gas is harmlessly decomposed and released. In addition, it is possible to provide an economical and practical hydrogen peroxide-ozone combined type wastewater treatment method that has good decomposition and removal efficiency of polluted organic substances.
[0036]
According to the invention of claim 5, since the water to be treated is pressurized and flows through the pipe , the amount of ozone (ΔO ₃ / toTOC) necessary for decomposing and removing the unit organic carbon amount is reduced. In addition, it is possible to realize advanced treatment of water by an economical and practical ozone treatment method using hydrogen peroxide with good decomposition and removal efficiency of polluted organic substances.
[0037]
According to the invention of claim 6, the ozone amount (ΔO ₃ / ΔTOC required for decomposing and removing the unit organic carbon amount is obtained by dividing and injecting the ozonized gas at a predetermined ratio and dividing and injecting it. ), The decomposition and removal efficiency of polluted organic matter is good, and the advanced treatment of water by the economical and practical ozone treatment method combined with hydrogen peroxide can be realized.
[0038]
According to the invention of claim 7, since the ozonized gas is dividedly injected at an evenly distributed injection amount, the ozone amount (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount is increased. And more efficiently processing.
[0039]
Further, according to the invention of claim 8, by injecting the entire amount of hydrogen peroxide injection rate, which is scheduled in advance for the water to be treated, without increasing the amount of ozone required (ΔO 3 _/ ΔTOC) It can be processed more efficiently.
[0040]
According to the invention of claim 9, since the reaction time between the water to be treated containing hydrogen peroxide and the ozonized gas is set to at least 8 seconds or more, the necessary amount of ozone (ΔO ₃ / ΔTOC) is increased. Can be processed more efficiently.
[Brief description of the drawings]
FIG. 1 is a view for explaining an embodiment of the apparatus of the present invention.
FIG. 2 is a reaction model and reaction formula used in the simulation of the present invention.
FIG. 3 is a diagram showing a change in TOC of treated water when hydrogen peroxide injection rate is 40 mg / L, injection ozone concentration is 120 mg / L, one-point injection, and two-point injection.
FIG. 4 shows the amount of ozone (ΔO ₃₎ required for decomposing and removing the unit organic carbon amount of one-point injection and two-point injection when injected at a hydrogen peroxide injection rate of 40 mg / L and an injection ozone concentration of 120 mg / L. / ΔTOC).
FIG. 5 shows the TOC when the injection gas flow rate is equal distribution and inclined distribution when the hydrogen peroxide injection rate is 10, 22, 40 mg / L, the injection ozone concentration is 60 mg / L, and the number of ozone injection points is four. FIG.
[Fig. 6] Unit organic carbon when the hydrogen peroxide injection rate is 10, 22, 40 mg / L, the injection ozone concentration is 60 mg / L, and the number of ozone injection points is 4 and the injection gas flow rate is equal distribution and gradient distribution. a processing characteristic diagram showing an amount of ozone (ΔO ₃ / ΔTOC) required to decompose and remove the amount.
FIG. 7 is a processing characteristic diagram showing a change in TOC in the case of four ozone injection points when the hydrogen peroxide injection method is initial injection and divided injection, and ozonized gas equal distribution.
FIG. 8 shows four ozone injection points when hydrogen peroxide is injected first and divided injections, and the amount of ozone necessary to decompose and remove the unit organic carbon amount in ozonated gas equal distribution (ΔO ₃ / It is a process characteristic figure which shows the change of (DELTA) TOC.
FIG. 9 is a process characteristic diagram showing the change in hydrogen peroxide in the ozonized gas even distribution when the hydrogen peroxide injection method is the initial injection and divided injection in four ozone injection points.
FIG. 10 is a processing characteristic diagram showing a change in TOC with respect to the number of injection points when injection is performed at a hydrogen peroxide injection rate of 40 mg / L and an injection ozone concentration of 120 mg / L.
FIG. 11 shows the change in the amount of ozone (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount with respect to the number of injection points when injected at a hydrogen peroxide injection rate of 40 mg / L and an injection ozone concentration of 120 mg / L. FIG.
FIG. 12 is a processing characteristic diagram showing the change in TOC with respect to the injected ozone concentration when the hydrogen peroxide injection rate is 40 mg / L.
FIG. 13 is a processing characteristic diagram showing a change in ozone amount (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount relative to the injected ozone concentration when the hydrogen peroxide injection rate is 40 mg / L. .
FIG. 14 is a processing characteristic diagram showing a change in TOC with respect to an injection rate of hydrogen peroxide when an injection ozone concentration is 60 mg / L.
FIG. 15 is a processing characteristic diagram showing a change in the amount of ozone (ΔO ₃ / ΔTOC) necessary for decomposing and removing the unit organic carbon amount with respect to the hydrogen peroxide injection rate when the injected ozone concentration is 40 mg / L. .
FIG. 16 is a configuration diagram of a conventional hydrogen peroxide combined ozone treatment apparatus.
FIG. 17 is a processing characteristic diagram showing the relationship between TOC concentration and ozone consumption by a conventional hydrogen peroxide combined ozone treatment apparatus.
[Explanation of symbols]
1 ozone reactor, 2 ozone generator, 3 treated water supply pump, 4 hydrogen peroxide addition pump, 5 ozonized gas inlet, 6 waste ozone decomposition device, 7 hydrogen peroxide storage tank, 8 gas-liquid separation tank, 9 Ozonized gas flow meter, a, b treated water piping, c treated water piping, d, e ozonized gas piping.

Claims

In an apparatus for adding and mixing hydrogen peroxide and ozone to water to be treated to decompose and remove organic substances in the water to be treated, the apparatus includes a pipe for water to be treated and means for adding hydrogen peroxide to the pipe. , Means for dividing and injecting ozonized gas into the pipe to be treated to which hydrogen peroxide has been added in at least two or more locations, and separating the undissolved ozonized gas and treated water after the pipe And a means for decomposing and releasing undissolved ozonized gas harmlessly, and an advanced wastewater treatment apparatus.

The wastewater advanced treatment apparatus according to claim 1, wherein a pipe of the water to be treated has a circular cross section.

The wastewater advanced treatment apparatus according to claim 1 or 2, wherein ozonized gas is introduced at least at four or more places.

In a method of adding and mixing hydrogen peroxide and ozone to the water to be treated to decompose and remove organic substances in the water to be treated, the water to be treated is passed through a pipe , and hydrogen peroxide is added to the water to be treated flowing through the pipe. Injecting and then separately injecting ozonized gas into treated water containing hydrogen peroxide and flowing through the pipe at at least two locations, separating undissolved ozonized gas and treated water after the pipe An advanced wastewater treatment method characterized in that undissolved ozonized gas is harmlessly decomposed and released.

The advanced treatment method of waste water according to claim 4, wherein the water to be treated is pressurized, and decomposition of organic matter in the water to be treated proceeds in the pipe .

The advanced wastewater treatment method according to claim 4 or 5, wherein the ozonized gas is distributed and injected in a predetermined amount.

The advanced treatment method of waste water according to claim 6, wherein the ozonized gas is divided and injected at an equally distributed injection amount.

The whole amount of the hydrogen peroxide injection amount scheduled for the water to be treated is injected before the ozonized gas is separately injected into the water to be treated. Advanced wastewater treatment method.

The wastewater advanced treatment method according to any one of claims 4 to 8, wherein a reaction time between the water to be treated containing hydrogen peroxide and the ozonized gas is set to at least 8 seconds or more.