JP4518235B2

JP4518235B2 - Water purification system

Info

Publication number: JP4518235B2
Application number: JP2003044192A
Authority: JP
Inventors: 宏明田中; 稔佐々木; 圭吾中村; 真司福井; 克知田中; 省三柴田
Original assignee: MATSUE DOKEN CO., LTD.; Public Works Research Institute; Yokogawa Electric Corp
Current assignee: MATSUE DOKEN CO., LTD.; Yokogawa Electric Corp; National Research and Development Agency Public Works Research Institute
Priority date: 2003-02-21
Filing date: 2003-02-21
Publication date: 2010-08-04
Anticipated expiration: 2023-02-21
Also published as: JP2004249248A

Description

【０００１】
【発明の属する技術分野】
本発明は湖沼、池、ダム等の閉鎖性水域等における溶存酸素（以下、ＤＯという）濃度や底層の水質および底質の改善システムに関する。
【０００２】
【従来の技術】
海（港湾）、湖沼、河川、ダム、堀等には生活排水や産業排水等が流入し、汚濁負荷を増大させている。また、港湾、ダム、堰は人工的な閉鎖性水域となり、自浄作用に必要な酸素を供給できなくなる。特に下層は酸素供給が消費量より少なくなり貧酸素状態となってしまう。
【０００３】
下層水が貧酸素状態に陥ると、底泥中の有機物は嫌気分解され、硫化水素やメタンガス等の生物にとって有害な物質が生成される。
また、底泥が酸素不足になるとリン等の栄養塩が溶出し易くなり、水中の栄養塩濃度を高め、赤潮等、植物プランクトンの異常増殖を引き起こす原因となる。
【０００４】
図１３は、港湾、湖沼、ダム、湖等（以下これらを総称して湖沼という）において夏季は水面付近（上層）は温度が高く、水深が下がると急に温度が低下する温度躍層Ａが形成された状態を示すもので、水底（下層）付近は温度が一番低くなっている（実線Ｃは温度分布曲線を示している）。
【０００５】
こうした状態では下層の温度が低く密度が大きい水は水塊を形成しており、表層付近の水温が高く密度が小さい水との混ざり合いはほとんどない。
従って、表層付近のＤＯ濃度の高い水は、下層へ供給されることはなく、下層の貧酸素状態は解消されない状態となっている。
【０００６】
このようなことは水温により成層化される水域だけでなく、汽水域のように塩分濃度の急激な変化が起きる塩分躍層の形成によっても同様な現象を生ずる。
本発明では、温度や塩分濃度または浮遊物質濃度の急変により密度差が生じ、成層化された水域より深い層を下層と定義する。また、密度差により成層化された領域を密度成層と定義する。
【０００７】
図１４はこのように劣化した下層の水質を改善する従来の装置を示すもので、散気装置によるもの、水流発生装置によるものなどの改善技術があり、図１４では湖沼の左側に散気装置による酸素供給技術を右側に水流発生装置による酸素供給技術を示している。
【０００８】
先づ、散気装置による酸素供給技術について説明する。散気装置はコンプレッサ２２により水底まで空気を送り、これを散気板２３から水底に放出するもので、下層の溶存酸素増加、及び連行水による温度躍層の破壊による上層からの溶存酸素を下層に供給することを狙ったものである。
【０００９】
次に、水流発生装置による酸素供給技術について説明する。図１４の右側に示すように、この酸素供給技術においては、水流発生装置を構成するポンプ２４によって溶存酸素の豊富な上層の水を吸い、下層に放出することにより周囲の水を連行水とし、下層水と混合させて溶存酸素供給を行うものである。
【００１０】
図１５は従来技術の他の例（原理図）を示すもので特開平１１-４７７８６号公報に記載されたものである。
図１５において、２０はポンプ船と称され、植物プランクトン及びＤＯ濃度の豊富な湖沼２１の表層水を吸水管２５を介してポンプ２４で吸込み、送水管２６にて下層（図中Ｂの領域）まで送り吐出口２７から放出させるものである。
【００１１】
下層Ｂと上層（図中Ａの領域）の境界は温度躍層２８と称され水の密度差が存在する。このため、下層Ｂへ送り込まれた表層水は下層Ｂの密度が大きい水と混合して、多少下層Ｂに留まり、プランクトン増殖を抑制する作用がある。
【００１２】
【特許文献１】
特開平１１−４７７８５号公報（第７頁、図８）
【００１３】
【発明が解決しようとする課題】
しかしながら、図１４の左側に示す水底に配置した散気板から空気を放出する方法では上昇流が発生して底泥を巻き上げ、水質をかえって悪化させてしまうという問題があった。
【００１４】
次に図１４の右側に示す水流発生装置を用いたものや、図１５に示す表層水をポンプで吸込み、下層で吐出させるものは上層の水の酸素溶解率が限られており、また、上層の水と下層の水に温度差があるため下層に送られた上層水は上方へ移動してしまい、この場合も改善箇所が限られたものとなり、効率的に問題があった。
【００１５】
本発明は上述のような課題を解決するためになされたもので、ＤＯ濃度を改善すべき水塊の水を汲み上げて酸素を注入し、高濃度酸素溶解水として再び汲み上げた水塊に戻すことにより、改善すべき水塊に限定し広い領域に渡って効率良く酸素を供給するとともに、底泥を巻き上げることのない水質浄化システムを提供することを目的としている。
【００１６】
【課題を解決するための手段】
この目的を達成する為に本発明は、請求項１においては、
水温が異なる密度成層を有する水域において、溶存酸素濃度を改善すべき水塊の水を吸引する吸引手段と、吸引した水に酸素を溶解し、その酸素溶解水を前記吸引した水塊へ吐出する吐出手段と、水深方向に前記改善すべき密度の異なる最低２水深を含むように複数個の温度計を配置し、前記溶存酸素濃度を改善すべき水塊の温度が所定のレベルに達したときに吸引及び吐出を中止するようにしたことを特徴とする。
【００１７】
請求項２においては、
塩分濃度が異なる密度成層を有する水域において、溶存酸素濃度を改善すべき水塊の水を吸引する吸引手段と、吸引した水に酸素を溶解し、その酸素溶解水を前記吸引した水塊へ吐出する吐出手段と、水深方向に前記改善すべき密度の異なる最低２水深を含むように複数個の導電率計を配置し、前記溶存酸素濃度を改善すべき水塊の導電率が所定のレベルに達したときに吸引及び吐出を中止するようにしたことを特徴とする。
【００１８】
請求項３においては、
浮遊物質濃度が異なる密度成層を有する水域において、溶存酸素濃度を改善すべき水塊の水を吸引する吸引手段と、吸引した水に酸素を溶解し、その酸素溶解水を前記吸引した水塊へ吐出する吐出手段と、水深方向に前記改善すべき密度の異なる最低２水深を含むように複数個の浮遊物質濃度計を配置し、前記溶存酸素濃度を改善すべき水塊の浮遊物質濃度が所定のレベルに達したときに吸引及び吐出を中止するようにしたことを特徴とする。
【００１９】
請求項４においては、請求項１又は請求項２または請求項３に記載の水質浄化システムにおいて、
前記温度計または前記導電率計又は前記浮遊物質濃度計はフロートから延長された紐に吊るされ、紐の端部が水底に配置したアンカーにより所定位置に固定されていることを特徴とする。
【００２１】
請求項５においては、請求項１乃至３のいずれかに記載の水質浄化システムにおいて、
前記溶存酸素濃度を改善すべき水塊に前記酸素溶解水を吐出するに際しては水面に対して平行若しくは僅かに下方に向けて吐出するようにしたことを特徴とする。
【００２２】
請求項６においては、請求項１乃至３のいずれかに記載の水質浄化システムにおいて、
前記溶存酸素濃度を改善すべき水塊に前記酸素溶解水を吐出するに際しては水面に対して垂直方向に吐出した水が水平方向に広がるように構成し、かつ、吐出された水によって水平方向の乱流が発生しない程度の速度で吐出するようにしたことを特徴とする。
【００２３】
請求項７においては、請求項１に記載の水質浄化システムにおいて、
前記溶存酸素濃度を改善すべき水塊に前記酸素溶解水を吐出するに際しては、その水塊の水温と同等の温度に冷却するために前記溶存酸素濃度を改善すべき水塊に配置され、コイル状又は蛇行配管を含む配管により配管を延長して構成した冷却手段を設けるとともに、前記冷却手段の、パイプの外側に熱交換用のフィンを複数設けたことを特徴とする。
【００２５】
請求項８においては、請求項１乃至３のいずれかに記載の水質浄化システムにおいて、
溶存酸素濃度を改善すべき水塊が存在する水域を複数領域に分割しそれぞれの領域に所定の距離を隔てて吸引／吐出口を設け、所定時間毎もしくはそれぞれの領域の溶存酸素濃度が所定のレベルに達したときに吸引／吐出口を切換えるようにしたことを特徴とする。
【００２７】
請求項９においては、請求項１乃至３のいずれかに記載の水質浄化システムにおいて、
吸引／吐出する水の少なくとも一方の溶存酸素濃度を測定する手段を設け、溶存酸素濃度が所定のレベルに達したときに吸引及び吐出を中止するようにしたことを特徴とする。
【００３２】
【発明の実施の形態】
図１は本発明の水質浄化システムの構成例を示す概略図である。図において、１は例えば市販のＰＳＡ（Pressure Swing Adsorption）方式を用いた酸素発生装置である。２は酸素発生器に空気を送出するコンプレッサである。３は吸引ポンプであり、湖沼２１の下層からパイプ５ａを介して水を汲み上げ、酸素溶解装置４に供給する。
【００３３】
酸素溶解装置４は例えば特開平１１−２０７１６２号公報に記載されたようなもので、図では省略するが、汲み上げた水が密閉タンクに注入され、同時に酸素発生装置で生成された酸素が加圧状態で供給される。そして、タンクに貯溜された水の水面に斜め上方向から汲み上げた水を噴射することにより、水に渦巻きを発生させながら酸素を溶け込ませるように構成されている。
【００３４】
上述の装置によれば泡の発生を抑制しながら高濃度の酸素溶解水を生成することができる。
生成された高濃度酸素溶解水は図示しない加圧ポンプ等の加圧手段により加圧されてパイプ５ｂを介して湖沼などの下層水塊に吐出される。
【００３５】
６（ａ，ｂ）はフロート（浮子）で、フロート６ａには所定の箇所に紐７ａの一端が接続され、他端は水底に配置されたアンカー８ａに接続されている。なお、この紐は例えばステンレス鋼やプラスチック樹脂等の腐食し難いものが使用され、深さ方向に所定の間隔で複数（図では6個）の温度センサ（９ａ〜９ｆ）が固定されている。なお、温度センサはＤＯ濃度を改善すべき水塊を含んで最低２台あればよい。
【００３６】
１０はドーナツ状に形成された浮き輪で、この浮き輪１０には外周を略３等分した箇所に３本の紐７ｃ，７ｄ，７ｅの一端が接続されている。そして、紐の他端はアンカー８ａを中心に所定の半径で描いた円周を略３等分した箇所に配置されたアンカー８ｂ，８ｃ，８ｄに接続されており、浮き輪１０は温度センサ９ｂと９ｃの間に沈められた状態で配置されている。
【００３７】
浮き輪１０には紐７ｂの一端が接続され他端は水面に浮かぶ浮子６ｂに接続されている。この紐７ｂの長さは増水や潮が満ちた場合などにより水面が上昇して浮子６ａが水中に没しても、６ｂのフロートは水中に没しないように余裕が持たせてある。
【００３８】
１２は測温抵抗体や熱電対等の温度センサ（９ａ〜９ｅ）からの信号を計測信号に変換する温度変換器、１３は入出力装置、１４は演算機能を有する表示手段であり、水深と水温の関係や水温の制御ポイント、躍層警報設定、制御目標水位、躍層範囲を演算した結果の傾き等が表示される。１６は吸引口、１７は吐出口である。
【００３９】
図２は湖沼２１の近傍に酸素発生装置１や酸素溶解装置４を配置した場合の本発明による水質浄化システムを示すもので、吐出パイプの先端に冷却手段１５を設けたものである。ここではパイプにドーナツ状のフィンを複数個設けた例を示している。この冷却手段１５の吐出口は水面に対して平行若しくは僅かに下向きにされる。なお、吸引口も平行か僅かに下向きに設けられ、これらは同じ深さの下層に配置されている。
【００４０】
図３は図２に示す冷却手段１５の詳細（ａ）と他の実施例（ｂ）を示すもので、（ｂ）は蛇行配管により下層での滞留時間を長くしている。この他パイプをコイル状に巻いたりしてもよい。
なお、吸入／吐出口を平行に維持する手段としては例えば水面に浮かべたフロート船をアンカーで繋留し、この船から平行に、かつ垂直に下層まで２本の棒を降しその棒の先端に水平に固定する。
【００４１】
図４は架台を設けたアンカー１８を水底に沈め、この架台に吸引口１６、吐出口１７を水平に固定した例を示す構成図である。
図４において、（１）で示す深さは例えば８ｍ，（２）は７.５ｍ，（３）で示す深さ（温度躍層Ａ）は４ｍである。また、アンカー１８は浮子6により水の吸引／吐出口が僅かに下方に向くように傾斜して配置されている。
【００４２】
図１，２，４において、高濃度酸素溶解水吐出口１７が水平若しくは僅かに下方に向けられ、また、吐出口からは高濃度酸素溶解水が吐出される為、吸引／吐出の水量は少ない水量で済む。その結果、水による底泥の巻き上げを防止することができる。なお、吸引されたＤＯ濃度を改善すべき水塊の水は酸素溶解装置４により高濃度に酸素が溶解され、生成された高濃度酸素溶解水は再びＤＯ濃度を改善すべき水塊に吐出されるが、吸引／吐出される途中や地上に配置された酸素溶解装置４で酸素を溶解している間に温度上昇が生じる。
【００４３】
その温度上昇は冷却手段により下層の水温と同等に冷却されるので高濃度酸素溶解水と下層の温度差に起因する上方（図２の矢印Ｂ方向）への拡散を防止することができ広い範囲に渡って水質浄化が可能である。
【００４４】
ところで、高濃度酸素溶解水が所定量吐出されると鉛直方向に緩やかな混合が起こりＤＯ濃度を改善すべき水塊（下層領域）の低温レベルが上昇する（又は上層領域の水温が下降する）。温度センサ９はＤＯ濃度を改善すべき水塊の上層と下層の温度変化を監視しており、ＤＯ濃度を改善すべき水塊の温度が予め定めた値に達すると温度変換器を介して表示手段１４に伝達される。その結果、表示手段の内部に組み込まれた警報機能が作動して吸入／吐出ポンプや酸素発生装置１及び酸素溶解装置４に対して運転の停止信号が出力される。
【００４５】
なお、広大な湖沼などの場合は１システムだけでは吸入／吐出量が限られ、酸素供給量が酸素消費量を下回ることが考えられる。その場合、湖沼の広さ、水深の具合、季節、流入／流出の程度を考慮して複数のシステムを配置する。
また、１システムで稼動した場合、所定の領域の溶存酸素量が高くなるに従って酸素移動効率が低下する。その場合は、図５に示すように吸引／吐出口を湖沼の所定の領域に複数個配置することも可能である。
【００４６】
図５において、Ａ，Ｂ，Ｃで示す部分は湖沼を３領域に区分けした状態を示すもので、それぞれの領域の水底付近にはパイプ５ａ〜５ｄを介して吸引口１６ａ，１６ｂ，１６ｃ及び吐出口１７ａ，１７ｂ，１７ｃが所定の距離を隔てて配置されている。１８ａ〜１８ｄはパイプ５ａ〜５ｆの流路を切換える例えば電磁弁である。
【００４７】
上述の構成において、はじめは電磁弁（ａ，ｂ）のみが開とされ、領域Ａの下層の吸引／吐出がおこなわれ、所定時間経過して酸素移動効率が低下したら電磁弁（ａ，ｂ）を閉として電磁弁（ｃ，ｄ）のみを開として、領域Ｂの浄化を行なう。更に所定時間が経過して領域Ｂの酸素移動効率が低下したら電磁弁（ｃ，ｄ）を閉として電磁弁（ｅ，ｆ）のみを開として、領域Ｃの浄化を行なう。
【００４８】
このように所定時間（日時）毎に又は図５に示すように吸引した下層水の溶存酸素の量をＤＯ濃度計１９ａで計測し、その計測値が予め定めた所定の値に改善された時点で電磁弁を切換えて運転することにより、１システムの稼動で広範囲の浄化が可能となる。なお、酸素溶解装置４の後段に設けたＤＯ濃度計１９ｂは前段に設けたＤＯ濃度計１９ａの値と比較して酸素溶解装置４の性能を監視するものである。この場合、所定の領域は深さ方向を含めた立体的な領域を含んでいるものとする。
【００４９】
例えば湖沼の底が階段状に深くなっている場合、段差部分の夫々に吸引／吐出口を配置し、最深部のＤＯ濃度が所定の値になった時にはその部分の吸引／吐出を中止し、他の段差部分の吸引／吐出を行なうことにより効率的な酸素の供給が可能となる。
【００５０】
図６，図７は本発明の水質浄化システムを用いて、ある貯水池における水塊のＤＯ濃度の改善を行った配置例を示すものである。
図６は本発明の水質浄化システムを設置した貯水池の平面図、図７は図６のセンターラインにおける断面図を示すものである。これらの図に示すように前ダム堤体のフロート２８上に設置された酸素溶解装置４から吸引／吐出パイプ５ａ,５ｂを延長し貯水池内の前ダム堤体から３０ｍのところに吸込口、７０ｍのところに吐出口を設けた。
【００５１】
また、前ダム堤体から５０ｍと１１０ｍのところに水深方向の水温とＤＯを測定するための温度センサおよびＤＯセンサを設置した。
センサ底部はアンカーで固定し、水面のフロートからケーブルを展張、温度センサは水深０.５ｃｍ、１.５ｍ、及び２．５ｍ以深は０.５ｍ間隔で、ＤＯ及びＯＲＰセンサは湖底面より約１ｍ上となる位置にそれぞれ設置した。吸込、吐出口にはそれぞれ水質分析用のサンプリング目標点とするためのブイを設置した。酸素発生装置は地上に設置したが、圧力容器を含む酸素溶解装置４は提体付近のフロート２８上に設置した。
【００５２】
また、この実施例では吸入／吐出口１６,１７をスピーカー状（末広がり）とし、水が３６０度の方向から吸引／吐出される構成とした。更に吸入に際しては底泥を吸込み難いように、また、吐出に際しては底泥を巻き上げないように中央部にコーン状の突起を有する円板３０を用い、これを吸入／吐出口１６,１７に所定の距離を隔てて対向して配置した。
【００５３】
このような吐出口１７から吐出される酸素溶解水は円板３０に当って３６０度の方向に広がっていくが、この場合の広がり速度によっては乱流となって底泥を巻き上げたり、水域層を乱す原因となる。従って本発明では酸素溶解水が層流状態で広がるように吐出速度を２０ｃｍ／秒以下とした。
【００５４】
図８は運転開始の前日の、提体から５０ｍ地点の水温と水深及びＤＯの状況を示している。両地点とも水深はおよそ６.３ｍとなっていた。この前週の台風の影響によって水温の勾配はなだらかになってしまったため、水温躍層はあまり明確ではないが、湖面付近と底層では１０℃以上の水温差が生じていた。また、ＤＯは４．５ｍ以深では完全に消費されている状況となっていた。
【００５５】
この翌日からテスト１として、酸素を溶解させずに２０時間、６時間３０分ほど停止した後さらに４２時間あまりの合計約３日間、９０ｍ^３／ｈｒの流量で３０ｍ地点から底層水を汲み上げ７０ｍ地点で吐出させる運転を行った。
【００５６】
図９はテスト１の前日、運転開始後１日、同３日、及び運転停止３日後の水温と水深の状況を示している。
水温変化の状況から、テスト１によって４ｍ以深の底層水が緩やかに撹拌混合されているものと推測された。表層付近の水温上昇は好天が続いた影響と考えられた。
【００５７】
図１０は１１０ｍ地点の水温と水深の状況を示している。５０ｍ地点とほぼ同様の結果を示しており、４ｍ以深の水温の推移に、上流方向にも吐出水が拡散し湖底から約２ｍの高さまでの底層水が撹拌されている様子が顕れていた。終了後３日間の運転停止期間では、テスト１によって撹拌混合した湖底から２ｍまでの底層水の水温は、深さ方向にむかってなだらかに低下していたテスト１の前日のような状況までは戻らなかった。
【００５８】
テスト１終了の４日後から、酸素を溶解させた水を底層に戻すテスト２を開始した。吸込み及び吐出流量はテスト１と同じ９０ｍ^３／ｈｒで、溶解装置出口で測定した吐出水のＤＯは運転開始から約５時間で５０ｍｇ/ｌに達し、その後の装置連続稼働中は５０〜６０ｍｇ/ｌ台で推移していた。５０m地点のＤＯ上昇が確認された運転開始後３５時間経過以降は、水温の状況等を勘案し間欠運転とした。
【００５９】
図１１はテスト２の前日から開始５日後までの５０ｍ地点の水温と水深及びＤＯの状況を示している。吐出口の開口部が水深でおよそ５.５ｍから６ｍにかけて位置していることから、同地点で吐出位置より１.０〜１.５ｍ程度上方まで酸素供給が行われており、また、池底付近では底質によって酸素が消費されているものと考えられる。
【００６０】
図１２は吸入口と吐出口の中間である５０ｍ地点だけでなく、図６に示す貯水池の提体と垂直方向に引いたセンターラインに沿って、テスト２開始１日後のＤＯを測定した結果をにまとめたものである。
図１２によれば、約1日間の底層への高濃度酸素水の供給によって、吸込部（３０ｍ地点）と吐出口（７０ｍ地点）間だけでなく、上流方向にも酸素の供給ができていることが確認できる。水温に関しても、酸素供給開始後３日目以降、概ね５０％以下の稼働率での間欠運転により表層部と底層部で１０℃以上の温度差が保たれており、実験に用いたシステムによって、温度躍層を破壊せずに底層のみへの酸素供給ができることが実証できた。
【００６１】
本発明の以上の説明は、説明および例示を目的として特定の好適な実施例を示したに過ぎない。したがって本発明はその本質から逸脱せずに多くの変更、変形をなし得ることは当業者に明らかである。例えば温度センサ９の固定方法や浮き輪１０の形状等は実施例に限るものではない。
【００６２】
また、実施例では密度変化の検出の目安として温度センサを用いたが、汽水域などで塩水を含む場合は導電率計を用いて密度変化を検出する。また浮遊物質による密度変化がある水域では、浮遊物質濃度計を用いてその密度変化を検出する。
また、パイプ５の流路を切換える手段は電磁弁に限るものではない。
特許請求の範囲の欄の記載により定義される本発明の範囲は、その範囲内の変更、変形を包含するものとする。
【００６３】
【発明の効果】
本発明の請求項１〜３の発明によれば、水温又は塩分濃度または浮遊物質濃度が異なる密度成層を有する水域において、溶存酸素濃度を改善すべき水塊の水を吸引する吸引手段と、吸引した水に酸素を溶解し、その酸素溶解水を前記吸引した水塊へ吐出する吐出手段と、前記水域の物理現象を検出する検出器とを具備し、前記改善すべき密度の異なる最低２水深を含むように、前記検出器を水深方向に複数個配置すると共に前記溶存酸素濃度を改善すべき水塊に前記酸素溶解水を吐出するに際しては、その水塊の水温又は塩分濃度または浮遊物質濃度が所定のレベルに達したときに吸引及び吐出を中止するようにしたので、下層の水質・底質改善を効果的に行なうと共に、電力の消費を押さえることができ、経済的な水質浄化システムを実現することができる。
【００６４】
請求項４の発明によれば、検出器がフロートから延長された紐に吊るされ、紐の端部が水底に配置したアンカーにより所定位置に固定されているので所定の領域の水温または導電率又は浮遊物質濃度を連続して監視することができる。
【００６５】
請求項５の発明によれば、前記溶存酸素濃度を改善すべき水塊に酸素溶解水を吐出するに際し、水面に対して平行若しくはわずかに下方に向けて吐出するようにしたので底泥を巻き上げることがない。
【００６６】
請求項６の発明によれば、前記溶存酸素濃度を改善すべき水塊に酸素溶解水を吐出するに際しては水面に対して垂直方向に吐出した水が水平方向に広がるように構成し、かつ、吐出された水によって水平方向の乱流が発生しない程度の速度で吐出するようにしたので、限定した水塊の水質浄化が可能となる。
【００６７】
請求項７の発明によれば、コイル状又は蛇行配管を含む配管により配管を延長して構成した冷却手段を設けるとともに、前記冷却手段の、パイプの外側に熱交換用のフィンを複数設けたので、効果的な冷却ができる。
【００６９】
請求項８の発明によれば、浄化すべき領域を複数領域に分割しそれぞれの領域に所定の距離を隔てて吸引／吐出口を設け所定時間毎に吸引／吐出口を切換えるようにしたので、所定時間（日時）毎もしくはそれぞれの領域の溶存酸素濃度が所定のレベルに達したときに電磁弁を切換えて運転することにより、１システムの稼動で広範囲の浄化が可能な水質浄化システムを実現することができる。
【００７０】
請求項９の発明によれば、吸引／吐出する水の少なくとも一方の溶存酸素濃度を測定する手段を設け、溶存酸素濃度が所定のレベルに達したときに吸引及び吐出を中止するようにしたので、電力の消費を押さえることができ、経済的な水質浄化システムを実現することができる。
【図面の簡単な説明】
【図１】本発明の実施形態の一例を示す図である。
【図２】冷却手段を用いた場合の高濃度酸素溶解水の広がり具合を示す図である。
【図３】冷却手段の一例を示す図である。
【図４】冷却手段を用いた場合の高濃度酸素溶解水の広がり具合を示す図である。
【図５】冷却手段の一例を示す図である。
【図６】本発明の水質浄化システムを用いて実証テストを行った貯水池の設置平面図である。
【図７】図６のセンタラインでの断面図である。
【図８】実験開始前の５０ｍ地点でのＤＯと水温と水深の関係を示す図である。
【図９】実験開始（テスト１）前後の５０ｍ地点での水温と水深の関係を示す図である。
【図１０】実験開始（テスト１）前後の７０ｍ地点での水温と水深の関係を示す図である。
【図１１】実験開始（テスト２）後の５０ｍ地点でのＤＯと水温と水深の関係を示す図である。
【図１２】実験開始（テスト２）１日後のセンターライン上でのＤＯと水深の分布を示す図である。
【図１３】湖沼などにおける温度躍層の状態を示す図である。
【図１４】従来例を示す図である。
【図１５】他の従来例を示す図である。
【符号の説明】
１酸素発生装置
２コンプレッサ
３吸引ポンプ
４酸素溶解装置
５ａ吸引パイプ
５ｂ吐出パイプ
６（ａ，ｂ）浮子
７（ａ，ｂ）紐
８（ａ〜ｄ）アンカー
９（ａ〜ｅ）温度センサ
１０浮き輪
１２温度変換器
１３入出力装置
１４表示手段
１５冷却手段
１６吸引口
１７吐出口
１８電磁弁
１９ＤＯ（溶存酸素）計
２０ポンプ船
２１湖沼
２８フロート
２９ブイ
３０円板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a system for improving dissolved oxygen (hereinafter referred to as DO) concentration, bottom water quality and bottom quality in closed water areas such as lakes, ponds, and dams.
[0002]
[Prior art]
Domestic wastewater and industrial wastewater flow into the sea (ports), lakes, rivers, dams, moats, etc., increasing the pollution load. In addition, harbors, dams, and weirs become artificial closed water areas, which cannot supply oxygen necessary for self-cleaning. In particular, in the lower layer, the oxygen supply becomes less than the consumption amount, resulting in a poor oxygen state.
[0003]
When the lower layer water falls into an anoxic state, the organic matter in the bottom mud is anaerobically decomposed, and substances harmful to living organisms such as hydrogen sulfide and methane gas are generated.
In addition, when the bottom mud becomes deficient in oxygen, nutrient salts such as phosphorus are likely to elute, increasing the concentration of nutrient salts in water and causing abnormal growth of phytoplankton such as red tide.
[0004]
FIG. 13 shows a temperature rise layer A in which the temperature near the water surface (upper layer) is high in the summer in harbors, lakes, dams, lakes, etc. (hereinafter collectively referred to as lakes), and the temperature suddenly decreases as the water depth decreases. It shows the formed state, and the temperature is the lowest in the vicinity of the water bottom (lower layer) (the solid line C shows the temperature distribution curve).
[0005]
In such a state, water having a low temperature and a high density in the lower layer forms a water mass, and hardly mixes with water having a high water temperature and a low density near the surface layer.
Accordingly, water with a high DO concentration near the surface layer is not supplied to the lower layer, and the poor oxygen state of the lower layer is not eliminated.
[0006]
Such a phenomenon occurs not only in the water area stratified by the water temperature, but also in the formation of a salt cradle layer in which the salinity concentration changes suddenly as in the brackish water area.
In the present invention, a density difference is caused by a sudden change in temperature, salinity concentration or suspended solid concentration, and a layer deeper than the stratified water area is defined as a lower layer. A region stratified by the density difference is defined as density stratification.
[0007]
FIG. 14 shows a conventional apparatus for improving the water quality of the lower layer thus deteriorated, and there are improvement techniques such as those using an air diffuser and a water flow generator. In FIG. 14, the air diffuser on the left side of the lake The oxygen supply technology by the water flow generator is shown on the right.
[0008]
First, an oxygen supply technique using an air diffuser will be described. The air diffuser sends air to the bottom of the water by the compressor 22 and releases it from the air diffuser plate 23 to the bottom of the water. It is aimed to supply to.
[0009]
Next, an oxygen supply technique using a water flow generator will be described. As shown on the right side of FIG. 14, in this oxygen supply technique, the surrounding water is taken as entrained water by sucking the upper layer water rich in dissolved oxygen by the pump 24 constituting the water flow generator and releasing it to the lower layer. The dissolved oxygen is supplied by mixing with lower layer water.
[0010]
FIG. 15 shows another example (principle diagram) of the prior art, which is described in Japanese Patent Application Laid-Open No. 11-47786.
In FIG. 15, 20 is called a pump ship, and the surface water of the lake 21 with abundant phytoplankton and DO concentration is sucked by the pump 24 through the water absorption pipe 25, and the lower layer (region B in the figure) by the water supply pipe 26. Until it is discharged from the discharge outlet 27.
[0011]
The boundary between the lower layer B and the upper layer (region A in the figure) is called a temperature jump layer 28 and there is a difference in water density. For this reason, the surface layer water fed to the lower layer B is mixed with the water having a higher density of the lower layer B, stays in the lower layer B to some extent, and has an action of suppressing plankton growth.
[0012]
[Patent Document 1]
JP 11-47785 A (Page 7, FIG. 8)
[0013]
[Problems to be solved by the invention]
However, in the method of releasing air from the diffuser plate arranged on the bottom of the water shown on the left side of FIG. 14, there is a problem that an upward flow is generated, the bottom mud is wound up, and the water quality is changed.
[0014]
Next, the one using the water flow generator shown on the right side of FIG. 14 or the one that sucks the surface layer water shown in FIG. 15 with a pump and discharges it at the lower layer has a limited oxygen dissolution rate in the upper layer. Since there is a temperature difference between the water in the water and the water in the lower layer, the upper layer water sent to the lower layer moves upward, and in this case as well, there are limited improvements and there is a problem efficiently.
[0015]
The present invention has been made to solve the above-mentioned problems, pumping up water in a water mass to improve DO concentration, injecting oxygen, and returning it to the water mass pumped up again as high-concentration oxygen-dissolved water. Therefore, it is intended to provide a water purification system that efficiently supplies oxygen over a wide area limited to a water mass to be improved and does not roll up bottom mud.
[0016]
[Means for Solving the Problems]
In order to achieve this object, the present invention provides, in claim 1,
In waters having a water temperature of different stratified, dissolved and suction means for sucking the water in the water masses should improve dissolved oxygen concentration, the oxygen sucked water, discharging the oxygen-dissolved water into the sucked water mass And a plurality of thermometers arranged to include at least two water depths having different densities to be improved in the water depth direction, and the temperature of the water mass to improve the dissolved oxygen concentration has reached a predetermined level. The suction and discharge are sometimes stopped .
[0017]
In claim 2 ,
In water areas with density stratification with different salinity concentrations, suction means for sucking water in the water mass whose dissolved oxygen concentration should be improved, oxygen is dissolved in the sucked water, and the oxygen-dissolved water is discharged to the sucked water mass A plurality of conductivity meters so as to include at least two water depths having different densities to be improved in the water depth direction, and the conductivity of the water mass to improve the dissolved oxygen concentration is at a predetermined level. It is characterized in that the suction and the discharge are stopped when it reaches .
[0018]
In claim 3 ,
In water areas having density stratification with different concentrations of suspended solids, suction means for sucking water in a water mass whose dissolved oxygen concentration should be improved, oxygen is dissolved in the sucked water, and the oxygen-dissolved water is supplied to the sucked water mass A plurality of suspended solids concentration meters are arranged so as to include a discharge means for discharging and at least two water depths having different densities to be improved in the water depth direction, and the suspended solid concentration of the water mass to be improved in the dissolved oxygen concentration is predetermined. The suction and the discharge are stopped when the level reaches the above level .
[0019]
In claim 4, Te water purification system smell of claim 1 or claim 2 or claim 3,
The thermometer or the conductivity meter or the suspended solids concentration meter suspended in straps extending from the float, characterized that you have been fixed in place by anchors that end of the strap is arranged on the sea bed.
[0021]
In Claim 5, in the water purification system in any one of Claims 1 thru | or 3 ,
When discharging the oxygen-dissolved water to the water mass whose dissolved oxygen concentration should be improved, the oxygen-dissolved water is discharged parallel or slightly downward with respect to the water surface .
[0022]
In Claim 6, in the water purification system in any one of Claims 1 thru | or 3 ,
When discharging the oxygen-dissolved water to the water mass to improve the dissolved oxygen concentration, the water discharged in a direction perpendicular to the water surface is configured to spread in the horizontal direction, and the water discharged in the horizontal direction It is characterized by discharging at a speed that does not generate turbulent flow .
[0023]
In Claim 7, in the water purification system of Claim 1 ,
When discharging the oxygen-dissolved water to the water mass to improve the dissolved oxygen concentration, the coil is disposed in the water mass to improve the dissolved oxygen concentration in order to cool to a temperature equivalent to the water temperature of the water mass, The cooling means is formed by extending a pipe by a pipe including a shape or a meandering pipe, and a plurality of fins for heat exchange are provided outside the pipe of the cooling means .
[0025]
In Claim 8, in the water purification system in any one of Claims 1 thru | or 3 ,
Divide the water area where the water mass to improve the dissolved oxygen concentration is divided into a plurality of areas, and provide suction / discharge ports at a predetermined distance in each area, and the dissolved oxygen concentration in each area is predetermined. The suction / discharge port is switched when the level is reached .
[0027]
In Claim 9, in the water purification system in any one of Claims 1 thru | or 3 ,
Means for measuring at least one of the dissolved oxygen concentration in the suction / discharge water provided, the dissolved oxygen concentration is characterized by being adapted to stop the suction and discharge upon reaching a predetermined level.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic view showing a configuration example of a water purification system of the present invention. In the figure, reference numeral 1 denotes an oxygen generator using a commercially available PSA (Pressure Swing Adsorption) system. A compressor 2 sends air to the oxygen generator. A suction pump 3 pumps water from the lower layer of the lake 21 through the pipe 5 a and supplies it to the oxygen dissolving device 4.
[0033]
The oxygen dissolving device 4 is, for example, as described in Japanese Patent Application Laid-Open No. 11-207162. Although omitted in the figure, the pumped water is injected into a sealed tank and simultaneously oxygen generated by the oxygen generator is pressurized. Supplied in state. And it is comprised so that oxygen may be dissolved, generating the swirl in water by injecting the water pumped up diagonally from the water surface stored in the tank.
[0034]
According to the above-described apparatus, it is possible to generate high-concentration oxygen-dissolved water while suppressing the generation of bubbles.
The generated high-concentration oxygen-dissolved water is pressurized by a pressurizing means such as a pressurizing pump (not shown) and discharged to a lower water mass such as a lake through a pipe 5b.
[0035]
6 (a, b) is a float (float). One end of a string 7a is connected to the float 6a at a predetermined location, and the other end is connected to an anchor 8a arranged on the bottom of the water. The string is made of, for example, stainless steel, plastic resin, or the like, which is not easily corroded, and a plurality (six in the figure) of temperature sensors (9a to 9f) are fixed at a predetermined interval in the depth direction. In addition, the temperature sensor should just be at least 2 units | sets including the water mass which should improve DO density | concentration.
[0036]
Reference numeral 10 denotes a floating ring formed in a donut shape, and one end of three strings 7c, 7d, and 7e is connected to the floating ring 10 at a location where the outer periphery is substantially divided into three equal parts. The other end of the string is connected to anchors 8b, 8c, and 8d arranged at approximately three equal parts of the circumference drawn with a predetermined radius around the anchor 8a, and the floating ring 10 is connected to the temperature sensor 9b. And 9c.
[0037]
One end of a string 7b is connected to the floating ring 10, and the other end is connected to a float 6b floating on the water surface. The length of the string 7b is given a margin so that the float of 6b does not immerse in the water even when the water surface rises due to water increase or when the tide is filled and the float 6a is submerged in the water.
[0038]
Reference numeral 12 denotes a temperature converter that converts a signal from a temperature sensor (9a to 9e) such as a resistance temperature detector or a thermocouple into a measurement signal, 13 denotes an input / output device, and 14 denotes a display means having an arithmetic function. And the control point of the water temperature, the climax alarm setting, the control target water level, the slope of the result of calculating the climax range, and the like are displayed. Reference numeral 16 denotes a suction port, and 17 denotes a discharge port.
[0039]
FIG. 2 shows the water purification system according to the present invention in the case where the oxygen generator 1 and the oxygen dissolving device 4 are arranged in the vicinity of the lake 21. The cooling means 15 is provided at the tip of the discharge pipe. Here, an example is shown in which a plurality of donut-shaped fins are provided on a pipe. The discharge port of the cooling means 15 is made parallel or slightly downward with respect to the water surface. The suction ports are also provided in parallel or slightly downward, and these are arranged in a lower layer of the same depth.
[0040]
FIG. 3 shows details (a) of the cooling means 15 shown in FIG. 2 and another embodiment (b). In (b), the residence time in the lower layer is extended by meandering piping. Other pipes may be wound in a coil shape.
As a means for maintaining the suction / discharge ports in parallel, for example, a float ship floating on the surface of the water is anchored by an anchor, and two rods are lowered from the ship to the lower layer in parallel and vertically to the tip of the rod. Fix horizontally.
[0041]
FIG. 4 is a block diagram showing an example in which the anchor 18 provided with a gantry is submerged in the bottom of the water and the suction port 16 and the discharge port 17 are fixed horizontally on the gantry.
In FIG. 4, the depth indicated by (1) is, for example, 8 m, (2) is 7.5 m, and the depth indicated by (3) (temperature jump layer A) is 4 m. Further, the anchor 18 is disposed so as to be inclined by the float 6 so that the water suction / discharge port is slightly directed downward.
[0042]
In FIGS. 1, 2, and 4, the high-concentration oxygen-dissolved water discharge port 17 is directed horizontally or slightly downward, and high-concentration oxygen-dissolved water is discharged from the discharge port, so that the amount of suction / discharge water is small. Just use water. As a result, it is possible to prevent the bottom mud from being rolled up by water. The water in the water mass to be improved in the DO concentration is dissolved in oxygen at a high concentration by the oxygen dissolving device 4, and the generated high concentration oxygen-dissolved water is discharged again to the water mass in the DO concentration to be improved. However, the temperature rises while oxygen is being dissolved in the oxygen dissolving device 4 arranged on the ground or during suction / discharge.
[0043]
The temperature rise is cooled by the cooling means to be equal to the water temperature of the lower layer, so that the upward diffusion (in the direction of arrow B in FIG. 2) due to the temperature difference between the high-concentration oxygen-dissolved water and the lower layer can be prevented. It is possible to purify water.
[0044]
By the way, when a predetermined amount of high-concentration oxygen-dissolved water is discharged, gentle mixing occurs in the vertical direction and the low-temperature level of the water mass (lower layer region) whose DO concentration should be improved increases (or the water temperature of the upper layer region decreases). . The temperature sensor 9 monitors the temperature change in the upper and lower layers of the water mass whose DO concentration should be improved. When the temperature of the water mass whose DO concentration should be improved reaches a predetermined value, the temperature sensor 9 displays the temperature via a temperature converter. Is transmitted to the means 14. As a result, an alarm function incorporated in the display means is activated and an operation stop signal is output to the suction / discharge pump, the oxygen generator 1 and the oxygen dissolver 4.
[0045]
In the case of a large lake or the like, it is conceivable that the intake / discharge amount is limited by only one system, and the oxygen supply amount is lower than the oxygen consumption amount. In that case, a plurality of systems are arranged in consideration of the size of the lake, the depth of the water, the season, and the degree of inflow / outflow.
Moreover, when it operates by 1 system, oxygen transfer efficiency falls as the amount of dissolved oxygen of a predetermined area | region becomes high. In that case, it is also possible to arrange a plurality of suction / discharge ports in a predetermined region of the lake as shown in FIG.
[0046]
In FIG. 5, the portions indicated by A, B, and C indicate a state where the lake is divided into three regions, and suction ports 16a, 16b, and 16c and discharges are provided near the bottom of each region through pipes 5a to 5d. The outlets 17a, 17b, and 17c are arranged at a predetermined distance. Reference numerals 18a to 18d are, for example, electromagnetic valves for switching the flow paths of the pipes 5a to 5f.
[0047]
In the above-described configuration, only the solenoid valves (a, b) are initially opened, and suction / discharge of the lower layer of the region A is performed. When the oxygen transfer efficiency decreases after a predetermined time has elapsed, the solenoid valves (a, b) Is closed and only the solenoid valves (c, d) are opened, and the region B is purified. When the oxygen transfer efficiency in the region B decreases after a predetermined time has passed, the solenoid valve (c, d) is closed and only the solenoid valve (e, f) is opened, and the region C is purified.
[0048]
Thus, every time (date and time) or as shown in FIG. 5, the amount of dissolved oxygen in the suctioned lower layer water is measured by the DO concentration meter 19a, and the measured value is improved to a predetermined value. By switching and operating the solenoid valve, it is possible to purify a wide range by operating one system. The DO concentration meter 19b provided at the rear stage of the oxygen dissolving device 4 monitors the performance of the oxygen dissolving device 4 in comparison with the value of the DO concentration meter 19a provided at the previous stage. In this case, it is assumed that the predetermined region includes a three-dimensional region including the depth direction.
[0049]
For example, when the bottom of a lake is deep like a staircase, a suction / discharge port is arranged at each step part, and when the DO concentration in the deepest part reaches a predetermined value, suction / discharge of that part is stopped, Efficient oxygen can be supplied by performing suction / discharge of other stepped portions.
[0050]
6 and 7 show an arrangement example in which the DO concentration of a water mass in a certain reservoir is improved using the water purification system of the present invention.
FIG. 6 is a plan view of a reservoir in which the water purification system of the present invention is installed, and FIG. 7 is a sectional view taken along the center line of FIG. As shown in these figures, the suction / discharge pipes 5a and 5b are extended from the oxygen dissolving device 4 installed on the float 28 of the front dam body, and a suction port 70m is located 30m from the front dam body in the reservoir. The discharge port was provided in the place.
[0051]
Moreover, the temperature sensor and DO sensor for measuring the water temperature and DO of a depth direction were installed in the place of 50m and 110m from the front dam body.
The bottom of the sensor is fixed with an anchor, and the cable is extended from the float on the surface of the water. Each was installed at the top position. A buoy for setting the sampling target point for water quality analysis was installed at each of the suction and discharge ports. The oxygen generator was installed on the ground, but the oxygen dissolver 4 including the pressure vessel was installed on the float 28 in the vicinity of the body.
[0052]
Further, in this embodiment, the suction / discharge ports 16 and 17 have a speaker shape (spreading), and water is sucked / discharged from a direction of 360 degrees. Further, a disc 30 having a cone-shaped protrusion at the center is used so that the bottom mud is difficult to suck during suction and the bottom mud is not rolled up during discharge. Were arranged facing each other with a distance of.
[0053]
The oxygen-dissolved water discharged from the discharge port 17 hits the disk 30 and spreads in the direction of 360 degrees, but depending on the spreading speed in this case, it becomes turbulent and winds up the bottom mud, Cause disturbance. Therefore, in the present invention, the discharge speed is set to 20 cm / second or less so that the oxygen-dissolved water spreads in a laminar flow state.
[0054]
FIG. 8 shows the water temperature, water depth, and DO status at a point 50 m from the body on the day before the start of operation. The water depth at both locations was approximately 6.3m. The gradient of the water temperature became gentle due to the influence of the typhoon last week, so the water temperature striking layer was not very clear, but there was a water temperature difference of 10 ° C or more between the lake surface and the bottom layer. In addition, DO was completely consumed at a depth of 4.5 m or more.
[0055]
From the next day, as Test 1, after stopping for 6 hours and 30 minutes without dissolving oxygen, the bottom water was pumped from 30m point at a flow rate of 90m ³ / hr for about 3 days in total for about 42 hours and 70m point. The operation to discharge was performed.
[0056]
FIG. 9 shows the water temperature and water depth the day before test 1, one day after the start of operation, three days after the start of operation, and three days after the stop of operation.
From the situation of the change in water temperature, it was estimated from Test 1 that the bottom layer water of 4 m or deeper was gently stirred and mixed. The rise in water temperature near the surface layer was considered to be the effect of continuous fine weather.
[0057]
FIG. 10 shows the water temperature and water depth at 110 m. The result was almost the same as that at the 50m point, and the state that the discharge water diffused in the upstream direction and the bottom water from the bottom of the lake to the height of about 2m was agitated in the transition of the water temperature deeper than 4m. During the three-day shutdown period, the temperature of the bottom water from the bottom of the lake agitated and mixed in Test 1 to 2 m has returned to the situation just before the previous day of Test 1, where it gradually decreased in the depth direction. There wasn't.
[0058]
Four days after the completion of Test 1, Test 2 was started in which water in which oxygen was dissolved was returned to the bottom layer. The suction and discharge flow rates were 90 m ³ / hr, the same as in Test 1, and the DO water measured at the dissolution device outlet reached 50 mg / l in about 5 hours from the start of the operation, and 50-60 mg / l during the subsequent continuous operation of the device. It was changing in 1 unit. After the start of operation when the DO rise at the 50 m point was confirmed, intermittent operation was performed in consideration of the water temperature.
[0059]
FIG. 11 shows the water temperature, water depth, and DO status at the 50 m point from the day before Test 2 to 5 days after the start. Since the opening of the discharge port is located from about 5.5m to 6m in depth, oxygen is supplied at about 1.0 to 1.5m above the discharge position. It is thought that oxygen is consumed by the sediment in the vicinity.
[0060]
FIG. 12 shows the result of measuring DO one day after the start of Test 2 not only at the 50-m point between the suction port and the discharge port, but also along the center line drawn in the vertical direction with the reservoir structure shown in FIG. Are summarized in
According to FIG. 12, by supplying high-concentration oxygen water to the bottom layer for about one day, oxygen can be supplied not only between the suction portion (30 m point) and the discharge port (70 m point) but also in the upstream direction. I can confirm that. Regarding the water temperature, since the third day after the start of oxygen supply, a temperature difference of 10 ° C. or more is maintained between the surface layer portion and the bottom layer portion by intermittent operation at an operation rate of approximately 50% or less, and depending on the system used in the experiment, It was proved that oxygen could be supplied only to the bottom layer without destroying the thermocline.
[0061]
The foregoing description of the present invention has only shown certain preferred embodiments for purposes of illustration and illustration. Accordingly, it will be apparent to those skilled in the art that the present invention can be modified and modified in many ways without departing from the essence thereof. For example, the fixing method of the temperature sensor 9 and the shape of the floating ring 10 are not limited to the embodiment.
[0062]
Moreover, although the temperature sensor was used as a standard of the detection of a density change in the Example, when a salt water is contained in a brackish water area etc., a density change is detected using a conductivity meter. In addition, in a water area where there is a density change due to suspended matter, the density change is detected using a suspended matter concentration meter.
The means for switching the flow path of the pipe 5 is not limited to the electromagnetic valve.
The scope of the present invention defined by the description in the appended claims is intended to include modifications and variations within the scope.
[0063]
【The invention's effect】
According to the first to third aspects of the present invention, in the water area having the density stratification with different water temperature, salinity concentration or suspended solid concentration, the suction means for sucking the water of the water mass whose dissolved oxygen concentration should be improved, and the suction A discharge means for discharging oxygen into the collected water and discharging the oxygen-dissolved water to the sucked water mass; and a detector for detecting a physical phenomenon in the water area, and having at least two water depths having different densities to be improved. When the oxygen-dissolved water is discharged into a water mass whose dissolved oxygen concentration is to be improved and a plurality of the detectors are arranged in the water depth direction so as to include the water temperature, salinity concentration or suspended solids concentration of the water mass Since the suction and discharge are stopped when the water reaches a predetermined level, the water quality and bottom quality of the lower layer can be effectively improved, and the consumption of electric power can be suppressed. Realization can do.
[0064]
According to the invention of claim 4, suspended in rope detector is extended from the float, the water temperature or the conductivity of the predetermined region since the end portion of the strap is secured in place by an anchor disposed on the water bottom or Suspended matter concentration can be monitored continuously.
[0065]
According to the invention of claim 5 , when the oxygen-dissolved water is discharged to the water mass whose dissolved oxygen concentration should be improved, it is discharged parallel or slightly downward with respect to the water surface. There is nothing.
[0066]
According to the invention of claim 6 , when the oxygen-dissolved water is discharged to the water mass to improve the dissolved oxygen concentration, the water discharged in the direction perpendicular to the water surface is configured to spread in the horizontal direction, and Since water is discharged at a speed that does not cause horizontal turbulence due to the discharged water, water quality purification of a limited water mass is possible.
[0067]
According to the seventh aspect of the present invention, the cooling means configured by extending the pipe by the pipe including the coiled shape or the meandering pipe is provided, and a plurality of fins for heat exchange are provided outside the pipe of the cooling means. Effective cooling .
[0069]
According to the invention of claim 8, the region to be purified is divided into a plurality of regions, and a suction / discharge port is provided in each region at a predetermined distance, and the suction / discharge port is switched every predetermined time. By switching and operating the solenoid valve at every predetermined time (date and time) or when the dissolved oxygen concentration in each region reaches a predetermined level, a water quality purification system capable of purifying a wide range by operating one system is realized. be able to.
[0070]
According to the ninth aspect of the present invention, there is provided means for measuring the dissolved oxygen concentration of at least one of the water to be sucked / discharged, and the suction and discharge are stopped when the dissolved oxygen concentration reaches a predetermined level. Therefore, it is possible to reduce power consumption and realize an economical water quality purification system.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an embodiment of the present invention.
FIG. 2 is a diagram showing how a high-concentration oxygen-dissolved water spreads when a cooling means is used.
FIG. 3 is a diagram illustrating an example of a cooling unit.
FIG. 4 is a diagram showing how a high-concentration oxygen-dissolved water spreads when a cooling means is used.
FIG. 5 is a diagram illustrating an example of a cooling unit.
FIG. 6 is an installation plan view of a reservoir subjected to a verification test using the water purification system of the present invention.
7 is a cross-sectional view taken along the center line in FIG. 6;
FIG. 8 is a diagram showing the relationship among DO, water temperature, and water depth at a 50 m point before the start of the experiment.
FIG. 9 is a diagram showing the relationship between water temperature and water depth at a point of 50 m before and after the start of the experiment (Test 1).
FIG. 10 is a diagram showing the relationship between water temperature and water depth at a point 70 m before and after the start of the experiment (Test 1).
FIG. 11 is a diagram showing a relationship among DO, water temperature, and water depth at a point of 50 m after the start of the experiment (test 2).
FIG. 12 is a diagram showing the DO and water depth distribution on the center line one day after the start of the experiment (Test 2).
FIG. 13 is a diagram showing a state of a temperature climbing layer in a lake or the like.
FIG. 14 is a diagram showing a conventional example.
FIG. 15 is a diagram showing another conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Oxygen generator 2 Compressor 3 Suction pump 4 Oxygen dissolution apparatus 5a Suction pipe 5b Discharge pipe 6 (a, b) Float 7 (a, b) String 8 (ad) Anchor 9 (ae) Temperature sensor 10 Floating Wheel 12 Temperature converter 13 Input / output device 14 Display means 15 Cooling means 16 Suction port 17 Discharge port 18 Solenoid valve 19 DO (dissolved oxygen) meter 20 Pump ship 21 Lake 28 Float 29 Buoy 30 Disc

Claims

In waters having a water temperature of different stratified, dissolved and suction means for sucking the water in the water masses should improve dissolved oxygen concentration, the oxygen sucked water, discharging the oxygen-dissolved water into the sucked water mass And a plurality of thermometers arranged to include at least two water depths having different densities to be improved in the water depth direction, and the temperature of the water mass to improve the dissolved oxygen concentration has reached a predetermined level. A water purification system characterized by occasionally stopping suction and discharge .

In water areas with density stratification with different salinity concentrations, suction means for sucking water in the water mass whose dissolved oxygen concentration should be improved, oxygen is dissolved in the sucked water, and the oxygen-dissolved water is discharged to the sucked water mass A plurality of conductivity meters so as to include at least two water depths having different densities to be improved in the water depth direction, and the conductivity of the water mass to improve the dissolved oxygen concentration is at a predetermined level. A water purification system characterized in that suction and discharge are stopped when it reaches the limit .

In water areas having density stratification with different concentrations of suspended solids, suction means for sucking water in a water mass whose dissolved oxygen concentration should be improved, oxygen is dissolved in the sucked water, and the oxygen-dissolved water is supplied to the sucked water mass A plurality of suspended solids concentration meters are arranged so as to include a discharge means for discharging and at least two water depths having different densities to be improved in the water depth direction, and the suspended solid concentration of the water mass to be improved in the dissolved oxygen concentration is predetermined. The water purification system is characterized in that the suction and the discharge are stopped when the level is reached .

The thermometer, the conductivity meter, or the suspended solids concentration meter is hung on a string extended from a float, and an end of the string is fixed at a predetermined position by an anchor disposed on a water bottom. The water purification system according to claim 1 or claim 2 or claim 3 .

Any one of claims 1 to 3, characterized in that when discharging the oxygen-dissolved water in the dissolved oxygen concentration water masses should improve was to be discharged toward the parallel or slightly downward relative to the water surface The water purification system described in 1.

When discharging the oxygen-dissolved water to the water mass to improve the dissolved oxygen concentration, the water discharged in a direction perpendicular to the water surface is configured to spread in the horizontal direction, and the water discharged in the horizontal direction The water purification system according to any one of claims 1 to 3 , wherein the water is discharged at a speed that does not generate turbulent flow .

When discharging the oxygen-dissolved water to the water mass to improve the dissolved oxygen concentration, the coil is disposed in the water mass to improve the dissolved oxygen concentration in order to cool to a temperature equivalent to the water temperature of the water mass, 2. The cooling device according to claim 1 , further comprising a cooling unit configured by extending a pipe with a pipe including a shape or a meandering pipe, and a plurality of heat exchange fins provided outside the pipe of the cooling unit . Water purification system.

Divide the water area where the water mass to improve the dissolved oxygen concentration is divided into a plurality of areas, and provide suction / discharge ports at a predetermined distance in each area, and the dissolved oxygen concentration in each area is predetermined. The water purification system according to any one of claims 1 to 3 , wherein the suction / discharge port is switched when the level is reached .

Means for measuring at least one of the dissolved oxygen concentration in the suction / discharge water provided, claims 1 to 3 dissolved oxygen concentration is characterized in that so as to stop the suction and discharge upon reaching the predetermined level The water purification system according to any one of the above.