JP2004275829A

JP2004275829A - Water quality improvement controlling device of confluential sewerage treatment equipment

Info

Publication number: JP2004275829A
Application number: JP2003068117A
Authority: JP
Inventors: Yukio Hiraoka; 岡由紀夫平
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2003-03-13
Filing date: 2003-03-13
Publication date: 2004-10-07
Anticipated expiration: 2023-03-13
Also published as: JP4439831B2

Abstract

<P>PROBLEM TO BE SOLVED: To more suitably control the exhaust amount of a pollution load to discharge points such as rivers by using a water quality improvement agent. <P>SOLUTION: In the subject controlling device of a confluential sewerage treatment equipment, measurement signals including rainfall signals (12), storm sewage pump well water level signals (29) and inflow conduit water level signals (28), and operation status signals denoting the operation status of a job site and including storm sewage pump operation status signals (14) and inflow gate operation status signals (8) are inputted into a process controller (11), the injection rate of a water quality improvement agent is calculated based on the measurement signals and operation status signals of the job site, and operation commands are outputted to a water quality improvement agent injection pump (20) based on the calculated injection rate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、雨水と汚水が同じ幹線に流入する合流式下水道の合流幹線を経由して雨水ポンプ井に流入した雨水を雨水ポンプにより汲み出し、汲み出した雨水に水質改善剤注入装置により水質改善剤を混入して放流先へ排出する合流式下水道処理設備の水質改善制御装置に関する。
【０００２】
【従来の技術】
合流式下水道では、雨天時に未処理の汚水が雨水とともに、河川等の公共用水域に排出されるので、水質汚濁等の問題を発生し、大きな問題となっている。
【０００３】
合流式下水道におけるこの種の水質汚濁の問題を解決する方法として、
（１）水貯留施設を設け、降雨を一時的に水貯留施設に貯留し、そこから処理場へ送って処理する方法、
（２）汚水管と雨水管を分離して整備し、汚水は汚水処理場へ送って処理する方法、
（３）渠内に一時的に雨水を貯留し、なるべく処理場への送水を多くする方法、
等がある。
【０００４】
しかし、（１）、（２）の方法については、雨水貯留設備や汚水管を建設するために多くのコストがかかり、またその整備のために膨大な時間もかかる。（３）の方法については、雨水は速やかに排出するという観点から見ると、雨水を管渠内に貯めるという逆の運用方法であり、降雨の状況によっては、溢れた水により浸水等を引き起こしてしまう虞がある、といった問題点がある。
【０００５】
そこで、この越流水の問題を解決する簡易的な方法として、雨水を雨水ポンプにより河川等に排出する際に、その吐出側で水質改善剤として消毒剤、例えば次亜塩素酸ナトリウム（以下、「次亜」と称する）等の消毒剤注入等による滅菌・消毒を行うことにより、河川等への水質汚濁の影響を低減する方法がある（例えば、特許文献１参照）。雨天時の流入雨水の特性として、降雨開始直後に汚濁負荷濃度が最も高く、降雨時間の経過により徐々にその濃度は低下する傾向にあることから、この消毒剤注入量は降雨開始後に排出する雨水への消毒剤注入率を高くし、その後この注入率を低くしていくことが望ましい。しかし、実際は、消毒剤注入率を一定にした制御（注入率一定制御）が一般的であり、降雨の状況や流入雨水の汚濁負荷濃度特性を考慮して、時々刻々と適量の水質改善剤、例えば消毒剤等を決定し、注入する方式はほとんど例を見ない。
【０００６】
【特許文献１】
特開２０００−１２９７６３号公報（図２とその説明）
【０００７】
【発明が解決しようとする課題】
本発明は、上述した合流式下水道越流水の対策として、河川等の放流先への汚濁負荷排出量を水質改善剤により、より適切に低減し得る、合流式下水道処理設備の水質改善制御装置を提供することを目的とする。
【０００８】
【課題を解決するための手段】
上記目的を達成するために請求項１に係る発明は、幹線流域の降雨量を表す降雨量信号、雨水ポンプ井に設置された水位計からの雨水ポンプ井水位信号、及び流入渠に設置された水位計からの流入渠水位信号を含む計測信号、並びに雨水ポンプ運転状況及び流入ゲート運用状況を含む現場の運用状況を表す運用状況信号を取込み、計測信号及び現場の運用状況信号をもとに水質改善剤の注入率を算定し、算定された注入率を達成するように水質改善剤注入装置に対し運用指令を出力するプロセスコントローラを備えたことを特徴とする。
【０００９】
この発明によれば、汚濁負荷発生量や降雨の状況を考慮した適切量の水質改善剤注入が可能であり、河川等の放流先への汚濁負荷排出を適切に低減することができる。
【００１０】
請求項２に係る発明は、請求項１に記載の水質改善制御装置において、水質改善剤注入装置が雨水ポンプ井から汲み出した雨水に水質改善剤を注入する注入ポンプを含み、プロセスコントローラから出力される運用指令が、注入ポンプの運転指令、停止指令及び回転数指令を含むことを特徴とする。
【００１１】
請求項３に係る発明は、請求項１に記載の水質改善制御装置において、プロセスコントローラが、雨水ポンプ井に流入する汚濁負荷流入量及び雨水ポンプの吐出量をもとに水質改善剤の注入率を算出することを特徴とする。
【００１２】
請求項４に係る発明は、請求項３に記載の水質改善制御装置において、プロセスコントローラが、流入渠水位信号、流入ゲート運用状況、地域住民の生活パターン及び工場廃水の規則的なパターンに従って排出される通常発生分の汚濁負荷量と、地表に堆積した汚濁負荷量が降雨時に下水管渠に流入する降雨時発生分汚濁負荷量と、に基づいて汚濁負荷流入量を推定することを特徴とする。
【００１３】
請求項５に係る発明は、請求項４に記載の水質改善制御装置において、プロセスコントローラが、通常発生分の汚濁負荷量を、少なくとも時刻、平日／休日の区別、及びイベントの有無を考慮して推定することを特徴とする。
【００１４】
請求項６に係る発明は、請求項４に記載の水質改善制御装置において、プロセスコントローラが、降雨時発生分汚濁負荷量を、降雨時発生分汚濁負荷全体量と、単位時間あたりの雨水流入量と、に基づいて推定することを特徴とする。
【００１５】
請求項７に係る発明は、請求項６に記載の水質改善制御装置において、プロセスコントローラが、汚濁負荷全体量を、地上雨量計により刻々と計測される降雨信号に基づいて、今回の降雨信号と前回の降雨信号との間にある一定時間以上の間隔が開いたときに今回の降雨と前回の降雨とを別の降雨とみなし、前回の降雨と今回の降雨との間の時間間隔を表す無降雨時間と、少なくとも日付および季節とを考慮して推定することを特徴とする。
【００１６】
請求項８に係る発明は、請求項７に記載の水質改善制御装置において、プロセスコントローラが、無降雨時間を、雨量レーダからの信号を処理して推定することを特徴とする。
【００１７】
請求項９に係る発明は、請求項７に記載の水質改善制御装置において、プロセスコントローラが、無降雨時間を、気象業務機関から配信される気象情報を利用して推定することを特徴とする。
【００１８】
請求項１０に係る発明は、請求項６に記載の水質改善制御装置において、プロセスコントローラが、単位時間あたりの雨水流入量を、地上雨量計により計測される降雨信号を単位時間当たりの降雨量に換算した降雨強度と、流入幹線に設置された幹線流量計もしくは幹線水位計により得られる幹線流量もしくは幹線水位と、流入渠に設置された水位計により計測される流入渠水位とを考慮して推定することを特徴とする。
【００１９】
請求項１１に係る発明は、請求項１０に記載の水質改善制御装置において、プロセスコントローラが、単位時間あたりの雨水流入量を、降雨強度と、幹線流量もしくは幹線水位と、流入渠水位とを考慮して、一定時間先までの雨水流入量として推定することを特徴とする。
【００２０】
請求項１２に係る発明は、請求項１１に記載の水質改善制御装置において、プロセスコントローラが、一定時間先までの雨水流入量を、雨量レーダからの信号を処理して推定することを特徴とする。
【００２１】
請求項１３に係る発明は、請求項１１に記載の水質改善制御装置において、プロセスコントローラが、一定時間先までの雨水流入量を、気象業務機関から配信される気象情報を利用して推定することを特徴とする。
【００２２】
請求項１４に係る発明は、請求項２ないし１３のいずれか１項に記載の水質改善制御装置において、プロセスコントローラが、現在継続中の降雨が終了したことが判定されたとき、終了した降雨に対する情報として、運用状況信号、計測信号、及び放流先水質の運用状況を保存する運転実績保存手段を備えていることを特徴とする。
【００２３】
請求項１５に係る発明は、請求項１４に記載の水質改善制御装置において、プロセスコントローラが、運転実績保存手段に保存された最新の降雨に関する情報を、各演算機能の演算式に自動的に反映させる手段を備えていることを特徴とする。
【００２４】
請求項１６に係る発明は、請求項１５に記載の水質改善制御装置において、プロセスコントローラが、運転実績保存手段に保存された降雨に関する情報を、要求により伝送路を介して支援端末に提供する手段を備えていることを特徴とする。
【００２５】
請求項１７に係る発明は、請求項１６に記載の水質改善制御装置において、支援端末から、プロセスコントローラに含まれる各演算機能の演算式を変更することができることを特徴とする。
【００２６】
【発明の実施の形態】
本発明の水質改善制御装置は、図１に示すように、流入幹線１及び流入渠２を介して流入した雨水１９を雨水ポンプ井３に導き、複数台の雨水ポンプ５を適宜運転し、吐出弁６及び放流管渠３７を介して雨水を河川等の放流先３３へ排出するプロセスにおいて、放流先３３の水質悪化を防止するために、放流先３３へ排出する排水に水質改善剤として次亜塩素酸ナトリウム（次亜）等の消毒剤を適切に注入するために消毒剤注入ポンプ２０をより適切に、より実情に即して運転するための制御装置に関するものである。
【００２７】
合流式下水道においては、雨水と汚水が同じ幹線に流入する。晴天時は、通常、流入幹線１に流入する汚水量が少ないため、雨水ポンプ井３に設けられた越流堰２３により流入渠２への流入が堰き止められ、汚水管渠３８を介して下水処理施設へ送水される。しかし、降雨により、流入幹線１に雨水が入ってくるようになると、雨水は越流堰２３を越えて流入渠２に流入し、さらに流入ゲート４が開くと、雨水ポンプ井３にも雨水が流入する。その雨水は複数台の雨水ポンプ５により放流先３３へ排出する。この時、排出する雨水には汚水分も混合されてしまうため、そのまま排出すると、放流先３３の水質を悪化させてしまうことになる。このため、消毒剤注入ポンプ２０により、排出する雨水に消毒剤を注入し、排出する雨水の水質を改善する。
【００２８】
設備本来の放流制御及び本発明による水質改善の制御はプロセスコントローラ１１を介して行われる。そのため、プロセスコントローラ１１はマイクロプロセッサを含み、ここには、雨水ポンプ５の運転状況信号１４、流入ゲート運用状況信号８、吐出弁６の開度を表す吐出弁開度信号１３、消毒剤注入ポンプ２０の運転状況信号２２、地上雨量計７からの降雨量信号１２、幹線流量計９（及び／又は幹線水位計）からの流量信号１０（及び／又は水位信号）、流入渠２に設けられた水位計２４からの流入渠水位信号２８、雨水ポンプ井３に設けられた水位計２５からの雨水ポンプ井水位信号２９、放流管渠３７に設けられた水位計２６からの放流管渠水位信号３０、及び放流先３３の水質を検出する水質計２７からの放流先水質信号３１が取込まれる。プロセスコントローラ１１はこれらの入力情報を用いて所要の論理演算を行い、雨水ポンプ制御指令１５を出力して雨水ポンプ５を制御し、消毒剤注入ポンプ制御指令２１を出力して消毒剤注入ポンプ２０を制御し、吐出弁開度指令１６を出力して吐出弁６の開度を制御し、流入ゲート制御信号３２を出力して流入ゲート４を制御する。所要の論理演算に用いる演算式は、内蔵または外付けの記憶手段ないし保存手段に保存されている。
【００２９】
さて、汚濁負荷は大きく分けて、住民の生活パターンや工場廃水等のある程度規則的なパターンにより排出される第１の汚濁負荷分（通常発生分の汚濁負荷）と、地表等に堆積した汚濁負荷が降雨時に下水管渠に流入する第２の汚濁負荷分（降雨時発生分の汚濁負荷）とに分けられる。第１の汚濁負荷分は、日間変動、週間変動等といった周期的な特性を有する。また、第２の汚濁負荷分は、季節の影響や前の降雨が終わってから次の降雨が始まるまでの時間（無降雨時間）等により大きな影響を受ける。雨天時の流入雨水の特性として、降雨開始直後に汚濁負荷濃度が最も高く、降雨時間の経過により徐々にその濃度は低下する傾向にあることから、この第２の汚濁負荷分の影響を考慮することは極めて重要なことになる。
【００３０】
実際の汚濁負荷の下水管渠への流入に際しては、汚濁負荷濃度は管渠に流れ込む雨水の量によっても影響を受ける。降雨開始直後に汚濁負荷濃度が高くなるとしても、緩やかな降雨と急激な降雨とでは、その汚濁負荷濃度の特性に違いが出る。したがって、降雨状況により管渠に流入する雨水流入量を予測し、これを考慮して汚濁負荷分を算出することも重要なことになる。
【００３１】
図２は本発明による水質改善制御を実施するプロセスコントローラ１１における、消毒剤注入率を算定する演算の機能構成の一例を示すものである。消毒剤注入率の算定にあたっては、大別して７つの機能手段１０１〜１０７、すなわち、第２の汚濁負荷分に対応する汚濁負荷全体量を推定する汚濁負荷全体量推定手段１０１、第１の汚濁負荷分を推定する汚濁負荷量推定手段１０２、雨水流入量演算手段１０３、第２の汚濁負荷分を推定する汚濁負荷量推定手段１０４、汚濁負荷越流量推定手段１０５、雨水ポンプ吐出量演算手段１０６、及び消毒剤注入率演算手段１０７を用いる。
【００３２】
汚濁負荷全体量推定手段１０１は、ある降雨において、日付や季節等のほか、降雨量信号１２及び必要に応じてその他の降雨情報を基にして決定される無降雨時間を参照して、地表等に堆積した汚濁負荷が降雨時に下水管渠に流入する汚濁負荷全体量を推定する。その場合、地上雨量計７で観測される降雨量信号１２により、降雨量信号１２の間隔がある一定時間以上に開けば別の降雨とみなし、その最初の降雨量信号発生時点を降雨開始タイミングと判定する。そして、その前回の降雨量信号が途絶えてから今回の降雨量信号が発生するまでの間隔を無降雨時間とする。この無降雨時間と日付や季節的な要素を考慮して、今回の降雨で発生する汚濁負荷全体量を推定する。
【００３３】
汚濁負荷量推定手段１０２は、地域住民の生活パターンや工場廃水等のある程度規則的なパターンにより排出される汚濁負荷分を推定する。この推定では、時刻、平日／休日モード、イベントの有無等の要素を考慮して、単位時間あたりの第１の汚濁負荷量を推定する。
【００３４】
雨水流入量演算手段１０３は、地上雨量計７で観測される降雨量信号１２を降雨強度に換算した値（単位時間あたりの降雨量を１時間あたりの値に換算したもの［ｍｍ／ｈ］）や、幹線流量計９（あるいは幹線水位計）からの流量信号１０（あるいは水位信号）、流入渠水位計２４によって検出された流入渠水位信号２８を利用して、雨水流入量演算式により流入幹線１に流入する単位時間あたりの雨水流入量を算出する。
【００３５】
汚濁負荷量推定手段１０４は、汚濁負荷全体量推定手段１０１によって推定された汚濁負荷全体量に基づき、雨水流入量演算手段１０３によって推定された単位時間あたりの雨水流入量を考慮して、単位時間あたりの第２の汚濁負荷量を推定する。単位時間あたりの汚濁負荷量は積算処理を行い、今回の降雨で発生するトータルの汚濁負荷量を上回れば、それ以降の単位時間あたりの汚濁負荷量を０にするといった処理も行う。
【００３６】
汚濁負荷量推定手段１０４で算出された単位時間あたりの汚濁負荷量と、汚濁負荷量推定手段１０２で算出された単位時間あたりの汚濁負荷量との合計が、単位時間あたりの総汚濁負荷量となる。
【００３７】
汚濁負荷越流量推定手段１０５は、越流堰２３を越えて雨水ポンプ井３に流入する単位時間あたりの汚濁負荷量を推定する。単位時間あたりの総汚濁負荷量のうち、一部あるいは全部は下水処理施設へ流れてしまう。このため汚濁負荷越流量推定手段１０５は、総汚濁負荷量のほか、流入渠２の水位（水位信号２８）、あるいは流入ゲート４の運用状況（運用状況信号８）を考慮して、単位時間あたりの汚濁負荷流入量を推定する。
【００３８】
雨水ポンプ吐出量演算手段１０６は、雨水ポンプ運転状況信号１４、雨水ポンプ井水位信号２９、及び放流管渠水位信号３０を利用して、雨水ポンプ５のＱ−Ｈ特性に基づき雨水ポンプ５の吐出量を演算する。
【００３９】
消毒剤注入率演算手段１０７は、汚濁負荷越流量推定手段１０５によって推定された単位時間あたりの汚濁負荷越流量と、雨水ポンプ吐出量演算手段１０６によって推定された雨水ポンプ吐出量により、適切な消毒剤注入率を算出し、消毒剤注入ポンプ制御指令として消毒剤注入ポンプ２０に対して出力する。
【００４０】
以上の演算により、過去の降雨における汚濁負荷発生量の統計データに基づいて汚濁負荷発生量を推定し、降雨の状況に応じた適切な消毒剤注入を行うことが可能となる。なお、これらの演算については、降雨地点等と雨水ポンプ井３との間の雨水の移動時間に対応する時間遅れを考慮する必要がある。このため、対象機場の特性を考慮して、時間遅れの影響を考慮するものとする。
【００４１】
汚濁負荷全体量推定手段１０１、汚濁負荷量推定手段１０２、汚濁負荷量推定手段１０４、および汚濁負荷越流量推定手段１０５の各推定演算においては、それぞれ種々あり得るモデル式の中からパラメータのチューニングを含めて適切なものを予め経験的に、あるいは実験的に選定しておけばよい。
【００４２】
汚濁負荷全体量推定手段１０１及び消毒剤注入率演算手段１０７では、対象機場における過去の降雨における汚濁負荷発生量の統計データや放流先の水質基準を満たすために必要な消毒剤注入量のデータを考慮することが不可欠である。したがって、降雨時の運転実績を保存し、このデータを、統計的手法を用いて演算式に反映させることにより、より精度の高い制御を行うことが可能となる。これらのデータの反映については、伝送路１８を介して監視端末１７から行う方式や、プロセスコントローラ１１内で自動的に降雨実績のファイリングやデータの反映を行わせることも可能である。
【００４３】
また、雨水流入量演算手段１０３による雨水流入量演算においては、一定時間先の雨水流入量を予測し、その要素を加味することも可能である。これには、地上雨量計７や幹線流量計９あるいは幹線水位計の測定結果だけでなく、例えば、雨量レーダ３５により観測されたデータを雨量レーダデータ処理装置３６によって処理し、その処理結果を利用する方式や、気象業務センター等から配信される各種気象データを利用する方式があり得る。その場合、雨量レーダデータ処理装置３６や、気象情報端末３４を介して入手可能な気象データ情報を、伝送路１８を介してプロセスコントローラ１１へ導入し、その情報を雨水流入量演算手段１０３の入力情報として利用することになる。さらに、雨量レーダデータ処理装置３６や、気象情報端末３４からの情報は、汚濁負荷全体量推定手段１０１における無降雨時間の算定に用いることもできる。
【００４４】
以上述べた実施の形態によれば、次のような作用効果を奏することができる。すなわち、
１）河川等の放流先３３へ排水する雨水の水質を適切に改善することができ、合流式下水道越流水の対策として有効である。
２）雨水滞水池等の大規模な施設を必要としないため、比較的安価に実現することができる。
３）過去の統計データに基づいた適切な水質改善剤注入ポンプの運用が可能である。
【００４５】
【発明の効果】
本発明によれば、合流式下水道越流水の水質改善対策として、過去の降雨における汚濁負荷発生量等の統計データに基づいて汚濁負荷発生量を推定し、降雨の状況に応じた適量の水質改善剤を注入することにより、河川等の放流先への汚濁負荷排出量をより適切に低減することができる。
【図面の簡単な説明】
【図１】本発明による水質改善制御装置の一実施形態を示すブロック図である。
【図２】図１の水質改善制御装置におけるプロセスコントローラの消毒剤注入率算定のための機能構成例を示すブロック図である。
【符号の説明】
１流入幹線
２流入渠
３雨水ポンプ井
４流入ゲート
５雨水ポンプ
６吐出弁
７地上雨量計
８流入ゲート運用状況信号
９幹線流量計もしくは幹線水位計
１０幹線流量もしくは幹線水位信号
１１プロセスコントローラ
１２降雨量信号
１３吐出弁開度信号
１４雨水ポンプ運転状況信号
１５雨水ポンプ制御指令
１６吐出弁開度変更指令
１７監視端末
１８伝送路
１９流入雨水
２０消毒剤注入ポンプ
２１消毒剤注入ポンプ制御指令
２２消毒剤注入ポンプ運転状況信号
２３越流堰
２４水位計（流入渠）
２５水位計（雨水ポンプ井）
２６水位計（放流管渠）
２７水質計
２８流入渠水位信号
２９雨水ポンプ井水位信号
３０放流管渠水位信号
３１放流先水質信号
３２流入ゲート制御信号
３３放流先（河川等）
３４気象情報端末
３５雨量レーダ
３６雨量レーダデータ処理装置
３７放流管渠
３８汚水管渠
１０１汚濁負荷全体量推定手段
１０２汚濁負荷量推定手段
１０３雨水流入量演算
１０４汚濁負荷量推定手段
１０５汚濁負荷流入量推定手段
１０６雨水ポンプ吐出量演算手段
１０７消毒剤注入率演算手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention uses a rainwater pump to pump out rainwater flowing into a rainwater pump well via a merging main line of a combined sewer in which rainwater and sewage flow into the same main line, and a water quality improving agent is injected into the pumped out rainwater by a water quality improving agent injection device. The present invention relates to a water quality improvement control device for a combined sewerage treatment facility that mixes and discharges to a discharge destination.
[0002]
[Prior art]
In the combined sewer system, untreated wastewater is discharged to public water bodies such as rivers together with rainwater during rainy weather, and thus causes problems such as water pollution, which is a serious problem.
[0003]
To solve this kind of water pollution problem in combined sewers,
(1) A method of providing a water storage facility, temporarily storing rainfall in the water storage facility, and sending the rainwater to a treatment plant for treatment.
(2) Separating and maintaining sewage pipes and rainwater pipes, and sending sewage to a sewage treatment plant for treatment.
(3) A method of temporarily storing rainwater in a culvert and increasing the amount of water sent to a treatment plant as much as possible.
Etc.
[0004]
However, the methods (1) and (2) require a lot of cost for constructing rainwater storage facilities and sewage pipes, and it takes enormous time for maintenance. The method (3) is the reverse operation method of storing rainwater in a sewer from the viewpoint of promptly discharging rainwater. Depending on the rainfall situation, flooding may cause flooding and the like. There is a problem that there is a possibility that it will occur.
[0005]
Therefore, as a simple method for solving the overflow water problem, when rainwater is discharged into a river or the like by a rainwater pump, a disinfectant such as sodium hypochlorite (hereinafter, referred to as “water hypochlorite”) is used as a water quality improving agent on the discharge side. There is a method for reducing the influence of water pollution on rivers and the like by performing sterilization and disinfection by injecting a disinfectant such as "hypoxia"). As the characteristics of rainwater inflow during rainy weather, the pollutant load concentration is highest immediately after the start of rainfall, and the concentration tends to gradually decrease over the course of the rainfall time. It is desirable to increase the injection rate of the disinfectant into the fuel, and then reduce the injection rate. However, in practice, a control with a constant disinfectant injection rate (constant injection rate control) is generally used. In consideration of the rainfall situation and the characteristics of the pollutant load concentration of the incoming rainwater, an appropriate amount of the water quality improver For example, there is almost no example of a method of determining and injecting a disinfectant or the like.
[0006]
[Patent Document 1]
JP-A-2000-129763 (FIG. 2 and its description)
[0007]
[Problems to be solved by the invention]
The present invention provides a water quality improvement control device for a combined sewer treatment facility, which can more appropriately reduce a pollutant load discharge amount to a discharge destination such as a river by a water quality improving agent as a countermeasure for the combined sewer overflow water described above. The purpose is to provide.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 has a rainfall signal indicating rainfall in a main basin, a rainwater pump well water level signal from a water level gauge installed in a rainwater pump well, and installed in an inflow culvert. The measurement signal including the inflow water level signal from the water level gauge and the operation status signal indicating the on-site operation status including the rainwater pump operation status and the inflow gate operation status are taken in, and the water quality is determined based on the measurement signal and the on-site operation status signal. A process controller is provided for calculating the injection rate of the improving agent and outputting an operation command to the water quality improving agent injection device so as to achieve the calculated injection rate.
[0009]
According to the present invention, it is possible to inject an appropriate amount of a water quality improving agent in consideration of a pollutant load generation amount and a rainfall situation, and to appropriately reduce a pollutant load discharge to a discharge destination such as a river.
[0010]
According to a second aspect of the present invention, in the water quality improvement control device according to the first aspect, the water quality improvement agent injection device includes an injection pump for injecting the water quality improvement agent into rainwater pumped from the rainwater pump well, and is output from the process controller. The operation commands include an operation command, a stop command, and a rotation speed command of the infusion pump.
[0011]
According to a third aspect of the present invention, in the water quality improvement control device according to the first aspect, the process controller sets the injection rate of the water quality improving agent based on a pollution load inflow amount flowing into the rainwater pump well and a discharge amount of the rainwater pump. Is calculated.
[0012]
According to a fourth aspect of the present invention, in the water quality improvement control device according to the third aspect, the process controller discharges water according to an inflow culvert water level signal, an inflow gate operation status, a living pattern of local residents, and a regular pattern of factory wastewater. The pollutant load inflow is estimated based on the pollutant load in normal occurrence and the pollutant load accumulated in the ground surface and the pollutant load in rainfall when the pollutant load flows into the sewer during rainfall. .
[0013]
According to a fifth aspect of the present invention, in the water quality improvement control device according to the fourth aspect, the process controller considers at least a time, a weekday / holiday distinction, and the presence / absence of an event by the process controller. It is characterized by estimation.
[0014]
According to a sixth aspect of the present invention, in the water quality improvement control device according to the fourth aspect, the process controller calculates the amount of pollution load generated during rainfall, the total amount of pollution load generated during rainfall, and the amount of rainwater inflow per unit time. And estimating based on
[0015]
According to a seventh aspect of the present invention, in the water quality improvement control device according to the sixth aspect, the process controller determines a total amount of the pollutant load based on a rainfall signal measured momentarily by a ground rain gauge and a current rainfall signal. When an interval of a certain time or more is opened between the previous rainfall signal and the previous rainfall signal, the current rainfall and the previous rainfall are regarded as different rainfalls, and no value indicating the time interval between the previous rainfall and the current rainfall is provided. The estimation is performed in consideration of the rainfall time and at least the date and the season.
[0016]
The invention according to claim 8 is the water quality improvement control device according to claim 7, wherein the process controller estimates the no-rainfall time by processing a signal from a rainfall radar.
[0017]
According to a ninth aspect of the present invention, in the water quality improvement control device according to the seventh aspect, the process controller estimates the non-rainfall time using weather information distributed from a meteorological service organization.
[0018]
According to a tenth aspect of the present invention, in the water quality improvement control device according to the sixth aspect, the process controller converts a rainwater inflow amount per unit time into a rainfall signal measured by a ground rain gauge into a rainfall amount per unit time. Estimated considering the converted rainfall intensity, the main flow or main water level obtained by the main flow meter or main water level meter installed on the inflow main line, and the inflow culvert water level measured by the water level meter installed on the inflow culvert. It is characterized by doing.
[0019]
According to an eleventh aspect of the present invention, in the water quality improvement control device according to the tenth aspect, the process controller considers a rainwater inflow amount per unit time, a rainfall intensity, a main flow rate or a main water level, and an inflow culvert water level. Then, it is estimated as the amount of rainwater inflow up to a certain time.
[0020]
According to a twelfth aspect of the present invention, in the water quality improvement control device according to the eleventh aspect, the process controller estimates a rainwater inflow amount up to a predetermined time ahead by processing a signal from a rainfall radar. .
[0021]
According to a thirteenth aspect of the present invention, in the water quality improvement control device according to the eleventh aspect, the process controller estimates a rainwater inflow amount up to a predetermined time ahead using weather information distributed from a meteorological service organization. It is characterized by.
[0022]
According to a fourteenth aspect of the present invention, in the water quality improvement control device according to any one of the second to thirteenth aspects, when the process controller determines that the currently continuing rainfall has ended, It is characterized by including an operation result storage means for storing the operation status signal, the measurement signal, and the operation status of the discharge water quality as information.
[0023]
According to a fifteenth aspect of the present invention, in the water quality improvement control device according to the fourteenth aspect, the process controller automatically reflects the latest rainfall information stored in the operation result storage means in the arithmetic expression of each arithmetic function. Characterized in that it is provided with means for causing it to:
[0024]
According to a sixteenth aspect of the present invention, in the water quality improvement control device according to the fifteenth aspect, the process controller provides the information on rainfall stored in the operation result storage means to the support terminal via a transmission path upon request. It is characterized by having.
[0025]
According to a seventeenth aspect of the present invention, in the water quality improvement control device according to the sixteenth aspect, an arithmetic expression of each arithmetic function included in the process controller can be changed from the support terminal.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
As shown in FIG. 1, the water quality improvement control device of the present invention guides rainwater 19 flowing through the inflow trunk line 1 and the inflow culvert 2 to the rainwater pump well 3, appropriately operates the plurality of rainwater pumps 5, and discharges the water. In the process of discharging rainwater to the discharge destination 33 such as a river through the valve 6 and the discharge pipe 37, in order to prevent the water quality of the discharge destination 33 from deteriorating, the wastewater discharged to the discharge destination 33 is used as a water quality improving agent as a water quality improving agent. The present invention relates to a control device for operating a disinfectant injection pump 20 more appropriately and in accordance with the actual situation in order to appropriately inject a disinfectant such as sodium chlorate (hypochlorite).
[0027]
In a combined sewer, rainwater and sewage flow into the same main line. When the weather is fine, the amount of sewage flowing into the inflow trunk line 1 is usually small, so that the overflow to the inflow channel 2 is blocked by the overflow weir 23 provided in the rainwater pump well 3, and the sewage is discharged through the sewage conduit 38. Water is sent to the treatment facility. However, when rainwater comes into the inflow main line 1 due to rainfall, the rainwater flows into the inflow channel 2 over the overflow weir 23, and when the inflow gate 4 is further opened, the rainwater also flows into the rainwater pump well 3. Inflow. The rainwater is discharged to a discharge destination 33 by a plurality of rainwater pumps 5. At this time, since the contaminated water is mixed with the discharged rainwater, if discharged as it is, the water quality of the discharge destination 33 will be deteriorated. Therefore, the disinfectant injection pump 20 injects a disinfectant into the discharged rainwater to improve the quality of the discharged rainwater.
[0028]
The original discharge control of the equipment and the control of water quality improvement according to the present invention are performed via the process controller 11. Therefore, the process controller 11 includes a microprocessor, in which an operation status signal 14 of the rainwater pump 5, an inflow gate operation status signal 8, a discharge valve opening signal 13 indicating the opening of the discharge valve 6, a disinfectant injection pump 20, an operation status signal 22; a rainfall signal 12 from the ground rain gauge 7; a flow signal 10 (and / or a water level signal) from the main flow meter 9 (and / or a main water level gauge); Inflow water level signal 28 from water level gauge 24, rainwater pump well water level signal 29 from water level gauge 25 provided in rainwater pump well 3, discharge water level signal 30 from water level gauge 26 provided in water discharge pipe 37 , And a discharge destination water quality signal 31 from a water quality meter 27 that detects the water quality of the discharge destination 33. The process controller 11 performs a required logical operation using the input information, outputs a rainwater pump control command 15 to control the rainwater pump 5, and outputs a disinfectant injection pump control command 21 to output the disinfectant injection pump 20. And outputs the discharge valve opening command 16 to control the opening of the discharge valve 6, and outputs the inflow gate control signal 32 to control the inflow gate 4. Arithmetic expressions used for required logical operations are stored in internal or external storage means or storage means.
[0029]
By the way, the pollution load is roughly divided into a first pollution load (normally generated pollution load) discharged according to a somewhat regular pattern such as a living pattern of residents and factory wastewater, and a pollution load accumulated on the ground surface. Is divided into a second pollutant load (a pollutant load generated during rainfall) that flows into a sewer pipe during rainfall. The first pollutant load has periodic characteristics such as daily variation, weekly variation, and the like. The second pollutant load is greatly affected by the influence of the season, the time from the end of the previous rainfall to the start of the next rainfall (no rainfall time), and the like. As the characteristics of the inflowing rainwater during rainy weather, the pollutant load concentration is highest immediately after the start of rainfall, and the concentration tends to gradually decrease as the rainfall time elapses. That becomes extremely important.
[0030]
When the actual pollutant load flows into the sewer, the pollutant load concentration is also affected by the amount of rainwater flowing into the sewer. Even if the pollutant load concentration increases immediately after the start of rainfall, there is a difference in the characteristics of the pollutant load concentration between gentle rainfall and rapid rainfall. Therefore, it is also important to predict the amount of rainwater flowing into the sewer according to the rainfall situation, and calculate the pollution load in consideration of this.
[0031]
FIG. 2 shows an example of a functional configuration of a calculation for calculating a disinfectant injection rate in the process controller 11 that performs the water quality improvement control according to the present invention. In calculating the disinfectant injection rate, there are roughly seven functional units 101 to 107, that is, a total pollutant load amount estimating unit 101 for estimating the total pollutant load amount corresponding to the second pollutant load, and a first pollutant load. Load estimating means 102 for estimating the amount of pollutant, rainwater inflow amount calculating means 103, pollutant load estimating means 104 for estimating the second pollutant load, pollutant load overflow estimating means 105, rainwater pump discharge amount calculating means 106, And the disinfectant injection rate calculating means 107 is used.
[0032]
The pollutant load total amount estimating means 101 refers to the non-rainfall time determined based on the rainfall signal 12 and other rainfall information as necessary in addition to the date, season, etc. Estimate the total amount of pollutant load that flows into sewers during rainfall. In this case, if the interval between the rainfall signals 12 is longer than a certain time by the rainfall signal 12 observed by the ground rain gauge 7, it is regarded as another rainfall, and the first rainfall signal generation time is defined as the rain start timing. judge. Then, an interval from when the previous rainfall signal is stopped to when the current rainfall signal is generated is defined as a non-rainfall time. Considering the non-rainfall time, date and seasonal factors, the total pollution load generated by the current rainfall is estimated.
[0033]
The pollutant load estimating means 102 estimates a pollutant load discharged according to a somewhat regular pattern such as a living pattern of a local resident or a factory wastewater. In this estimation, the first pollution load amount per unit time is estimated in consideration of factors such as time, weekday / holiday mode, presence / absence of an event, and the like.
[0034]
The rainwater inflow calculating means 103 converts the rainfall signal 12 observed by the ground rain gauge 7 into a rainfall intensity (a rainfall per unit time converted into a value per hour [mm / h]). Also, using the flow signal 10 (or water level signal) from the main flow meter 9 (or main water level meter) and the inflow culvert water level signal 28 detected by the inflow culvert water level meter 24, the inflow main line is calculated by a rainwater inflow amount calculation formula. Calculate the amount of rainwater inflow per unit time flowing into 1.
[0035]
The pollutant load amount estimating means 104 is based on the total pollutant load amount estimated by the pollutant load total amount estimating means 101, and takes into consideration the rainwater inflow amount per unit time estimated by the Estimate the second pollution load per unit. The pollutant load per unit time is subjected to an integration process, and if the total pollutant load generated by the current rainfall is exceeded, a process of setting the pollutant load per unit time thereafter to zero is also performed.
[0036]
The sum of the pollutant load per unit time calculated by the pollutant load estimating means 104 and the pollutant load per unit time calculated by the pollutant load estimating means 102 is the total pollutant load per unit time. Become.
[0037]
The pollutant load overflow estimation means 105 estimates the pollutant load per unit time flowing into the rainwater pump well 3 over the overflow weir 23. Some or all of the total pollution load per unit time flows to the sewage treatment facility. For this reason, the pollutant load overflow estimating means 105 considers the water level of the inflow culvert 2 (water level signal 28) or the operation status of the inflow gate 4 (operation status signal 8) in addition to the total pollution load amount. Estimate the pollutant load inflow of.
[0038]
The rainwater pump discharge amount calculating means 106 uses the rainwater pump operation status signal 14, the rainwater pump well water level signal 29, and the discharge pipe water level signal 30 to discharge the rainwater pump 5 based on the QH characteristic of the rainwater pump 5. Calculate the quantity.
[0039]
The disinfectant injection rate calculating means 107 performs appropriate disinfection based on the pollutant load overflow rate per unit time estimated by the pollutant load overflow rate estimating means 105 and the rainwater pump discharge amount estimated by the rainwater pump discharge amount calculating means 106. The dispensing rate is calculated and output to the disinfectant infusion pump 20 as a disinfectant infusion pump control command.
[0040]
By the above calculation, it is possible to estimate the pollution load generation amount based on the statistical data of the pollution load generation amount in the past rainfall, and to perform an appropriate disinfectant injection according to the rainfall situation. In these calculations, it is necessary to consider a time delay corresponding to the traveling time of rainwater between the rainfall point or the like and the rainwater pump well 3. For this reason, the influence of the time delay is to be considered in consideration of the characteristics of the target station.
[0041]
In each estimation calculation of the pollutant load total amount estimating means 101, the pollutant load amount estimating means 102, the pollutant load amount estimating means 104, and the polluting load overflow amount estimating means 105, parameters are tuned from various possible model expressions. It is sufficient to select an appropriate one in advance, empirically or experimentally.
[0042]
The pollutant load total amount estimating means 101 and the disinfectant injection rate calculating means 107 obtain statistical data on the amount of pollutant load generated in the past rainfall at the target plant and data on the disinfectant injection amount necessary to satisfy the water quality standard at the discharge destination. It is essential to consider. Therefore, by storing the operation results at the time of rainfall and reflecting this data in the arithmetic expression using a statistical method, it is possible to perform more accurate control. Regarding the reflection of these data, it is possible to use a method performed from the monitoring terminal 17 via the transmission line 18 or to automatically file the rainfall results and reflect the data within the process controller 11.
[0043]
Also, in the rainwater inflow calculation by the rainwater inflow calculation means 103, it is possible to predict the rainwater inflow at a certain time ahead, and to add its element. For this, not only the measurement results of the ground rain gauge 7, the main flow meter 9, or the main water level meter, but also, for example, data observed by the rain radar 35 are processed by the rain radar data processing device 36, and the processing results are used. Or a method using various types of weather data distributed from a weather service center or the like. In this case, weather data information available via the rainfall radar data processing device 36 or the weather information terminal 34 is introduced into the process controller 11 via the transmission line 18, and the information is input to the rainwater inflow amount calculation means 103. It will be used as information. Further, information from the rainfall radar data processing device 36 and the weather information terminal 34 can be used for the calculation of the no-rainfall time in the pollutant load total amount estimating means 101.
[0044]
According to the embodiment described above, the following operation and effect can be obtained. That is,
1) The quality of rainwater drained to a discharge destination 33 such as a river can be appropriately improved, and it is effective as a countermeasure for a combined sewer overflow.
2) Since large-scale facilities such as rainwater ponds are not required, it can be realized at relatively low cost.
3) It is possible to operate an appropriate water quality improver injection pump based on past statistical data.
[0045]
【The invention's effect】
According to the present invention, as a measure for improving the water quality of the combined sewer overflow, the pollution load generation amount is estimated based on statistical data such as the pollution load generation amount in the past rainfall, and an appropriate amount of water quality improvement according to the rainfall situation is performed. By injecting the agent, it is possible to more appropriately reduce the pollutant load discharge to a discharge destination such as a river.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a water quality improvement control device according to the present invention.
FIG. 2 is a block diagram showing a functional configuration example for calculating a disinfectant injection rate of a process controller in the water quality improvement control device of FIG. 1;
[Explanation of symbols]
Reference Signs List 1 inflow main line 2 inflow culvert 3 rainwater pump well 4 inflow gate 5 rainwater pump 6 discharge valve 7 ground rain gauge 8 inflow gate operation status signal 9 main flow meter or main water level gauge 10 main flow or main water level signal 11 process controller 12 rainfall Signal 13 Discharge valve opening signal 14 Rainwater pump operation status signal 15 Rainwater pump control command 16 Discharge valve opening change command 17 Monitoring terminal 18 Transmission line 19 Inflowing rainwater 20 Disinfectant injection pump 21 Disinfectant injection pump control command 22 Disinfectant injection Pump operation status signal 23 Overflow weir 24 Water level gauge (inflow culvert)
25 Water level gauge (rainwater pump well)
26 Water level gauge (discharge sewer)
27 Water quality meter 28 Inflow water level signal 29 Rainwater pump well water level signal 30 Outflow pipe water level signal 31 Outflow water quality signal 32 Inflow gate control signal 33 Outflow destination (river, etc.)
34 Meteorological information terminal 35 Rainfall radar 36 Rainfall radar data processing device 37 Discharge pipe 38 Sewage pipe 101 Pollution load total amount estimation means 102 Pollution load amount estimation means 103 Rainwater inflow calculation 104 Pollution load estimation means 105 Pollution load inflow Estimating means 106 Rainwater pump discharge amount calculating means 107 Disinfectant injection rate calculating means

Claims

Rainwater and sewage flow into the same main line.The rainwater that has flowed into the rainwater pump well via the combined main line of the sewer is pumped out by a rainwater pump, and the extracted rainwater is mixed with a water quality improver by a water quality improver injection device and released. In the water quality improvement control device of the combined sewerage treatment equipment to be discharged earlier,
A rainfall signal representing the amount of rainfall in the main watershed, a rainwater pump well water level signal from a water gauge installed on the rainwater pump well, and a measurement signal including an inflow culvert water level signal from a water gauge installed on the inflow culvert, and It takes in an operation status signal representing the operation status of the site including the rainwater pump operation status and the inflow gate operation status, calculates the injection rate of the water quality improver based on the measurement signal and the operation status signal of the site, and was calculated. A water quality improvement control device for a combined sewerage treatment facility, comprising: a process controller that outputs an operation command to the water quality improvement agent injection device so as to achieve an injection rate.

The water quality improving agent injection device includes an injection pump for injecting a water quality improving agent into rainwater pumped from the rainwater pump well, and operation commands output from the process controller include an operation command, a stop command, and a rotation speed of the injection pump. The water quality improvement control device for a combined sewer system according to claim 1, further comprising a command.

The merging method according to claim 1, wherein the process controller calculates an injection rate of the water quality improving agent based on a pollutant load inflow amount flowing into the rainwater pump well and a discharge amount of the rainwater pump. Water quality improvement control device for sewage treatment equipment.

The process controller is configured to control the inflow culvert water level signal, the inflow gate operation status, the local residents' living pattern and the regular pattern of industrial wastewater discharged in accordance with the regular load of pollutant load, and the amount of pollutant load deposited on the ground surface. The water quality improvement control device for a combined sewerage treatment facility according to claim 3, wherein the pollutant load inflow amount is estimated based on a pollutant load amount generated at the time of rainfall that flows into a sewer pipe during rainfall. .

5. The combined sewerage treatment equipment according to claim 4, wherein the process controller estimates the pollutant load amount of the normal occurrence in consideration of at least a time, a weekday / holiday distinction, and the presence or absence of an event. Water quality improvement control device.

The process controller according to claim 4, wherein the process controller estimates the amount of pollution load generated during rainfall based on the total amount of pollution load generated during rainfall and the amount of rainwater inflow per unit time. Water quality improvement control device for combined sewerage treatment equipment.

The process controller, the total amount of the pollutant load, based on the rain signal is measured by the ground rain gauge, when a certain time interval or more is opened between the current rain signal and the previous rain signal The current rainfall and the previous rainfall are regarded as different rainfalls, and the non-rainfall time indicating the time interval between the previous rainfall and the current rainfall is estimated in consideration of at least the date and season. The water quality improvement control device for a combined sewerage treatment facility according to claim 6.

The water quality improvement control device for a combined sewerage treatment facility according to claim 7, wherein the process controller estimates the non-rainfall time by processing a signal from a rainfall radar.

The apparatus according to claim 7, wherein the process controller estimates the non-rainfall time using weather information distributed from a meteorological service organization.

The process controller is configured to convert the rainwater inflow per unit time into a rainfall intensity obtained by converting a rainfall signal measured by a ground rain gauge into a rainfall per unit time, and a main flow meter or a main water level installed on the inflow main line. 7. The combined sewerage treatment equipment according to claim 6, wherein the estimation is performed in consideration of a main flow rate or a main water level obtained by a meter and an inflow water level measured by a water level meter installed in the inflow water channel. Water quality improvement control device.

The process controller estimates the rainwater inflow amount per unit time as the rainwater inflow amount up to a certain time ahead in consideration of the rainfall intensity, the main flow or the main water level, and the inflow culvert water level. The water quality improvement control device for a combined sewerage treatment facility according to claim 10, wherein:

The water quality improvement control device for a combined sewerage treatment facility according to claim 11, wherein the process controller estimates a rainwater inflow amount up to the predetermined time ahead by processing a signal from a rainfall radar.

The water quality improvement of the combined sewerage treatment equipment according to claim 11, wherein the process controller estimates the amount of rainwater inflow up to the predetermined time ahead using weather information distributed from a meteorological service organization. Control device.

The process controller, when it is determined that the currently continuing rainfall has ended, as the information on the finished rainfall, the operation status signal, the measurement signal, and an operation result storage unit that stores the operation status of the discharge water quality. The water quality improvement control device for a combined sewerage treatment facility according to any one of claims 2 to 13, further comprising:

15. The process controller according to claim 14, wherein the process controller includes a unit for automatically reflecting information on the latest rainfall stored in the operation result storage unit in an arithmetic expression of each arithmetic function. Water quality improvement control device for combined sewerage treatment equipment.

The combined sewer according to claim 15, wherein the process controller includes means for providing the information on rainfall stored in the operation result storage means to the support terminal via a transmission line upon request. Water quality improvement control device for treatment equipment.

17. The water quality improvement control device for a combined sewerage treatment facility according to claim 16, wherein a calculation expression of each calculation function included in the process controller can be changed from the support terminal.