JP2004183376A

JP2004183376A - Treatment method for surface drainage, and treatment equipment

Info

Publication number: JP2004183376A
Application number: JP2002353258A
Authority: JP
Inventors: Masato Mochizuki; 正人望月; Minoru Inaba; 実稲葉; Yoshio Tainaka; 善雄田井中; Keiko Wada; 桂子和田; Masabumi Kanazawa; 正文金沢; Shinji Manabe; 信治間鍋
Original assignee: LAKE BIWA YODO RIVER WATER QUA; LAKE BIWA-YODO RIVER WATER QUALITY PRESERVATION ORGANIZATION; Shiga Prefectural Government.; Toray Engineering Co Ltd
Current assignee: LAKE BIWA YODO RIVER WATER QUA; LAKE BIWA-YODO RIVER WATER QUALITY PRESERVATION ORGANIZATION; Shiga Prefectural Government.; Toray Engineering Co Ltd
Priority date: 2002-12-05
Filing date: 2002-12-05
Publication date: 2004-07-02
Anticipated expiration: 2022-12-05
Also published as: JP3768186B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a selective treatment method and device for only initial flash drain with a large pollutant load outflowing from the surface of a pavement road, generating at the initial stage of rainfall or water spray. <P>SOLUTION: In treatment equipment 1 of surface drainage, when the initial flash drainage in rainwater drain outflowing in a side ditch is shared, the side ditch drainage basin cover is formed in a double structural water sharing section 2. Water from the initial rainwater to a treatment objective volume is introduced into a water collection ditch 4 of the periphery of the water sharing section and after the water collection ditch 4 becomes full, the equipment is constituted in such a water sharing structure that the spillage after the initial flash drainage is guided to the inside existing drain opening. The initial flash drainage shared by the sharing section 2 is conveyed to a reservoir 3 through a water pipe 5 installed in the water collection ditch 4 of the water sharing section 2 and purified by treatment soil charged in the reservoir 3. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、降雨時又は散水時の初期に発生する国道又は高速自動車道等の舗装道路路面の高濃度排水（以下、初期フラッシュ排水という）の処理方法及び処理設備に関する。
【０００２】
【従来の技術】
国道又は高速自動車道等の路面には、土砂、塵等の他に、主として走行中の自動車から排出される微粒子状の物質が道路一面に散乱分布している。従来、路面の清掃は人手によるか、ブラシ・バキューム等の動力源を用いた移動可能な自動車で行われているが、十分でなく、上記物質は降雨時又は散水時に路面排水となって道路側溝を経て近辺の水田、河川他、湖沼等に流入して水質悪化をもたらしている。
【０００３】
現在、特定事業場から公共用水域に排出される水質についての排出基準、あるいは農業用水基準は定められているが、路面排水の法的規制はない。近時、環境問題への関心の高まりから河川や湖沼等の水質が問題視されるようになり、路面排水の処理が必要不可欠になりつつある。その為、道路側溝から集められた路面排水を流す排水溝をバイパスして路面排水を処理槽で浄化処理して処理水を排水溝に戻す路面排水処理に関する技術が開示されている（例えば、特許文献１参照。）。また、同様に道路近傍に設置した処理装置（上端が開放され、下端部が連通された複数の処理槽）で路面排水を浄化して放流する排水処理装置に関する技術が開示されている（例えば、特許文献２参照。）。
【０００４】
【特許文献１】特開２００１年第４９６４７号公報
【特許文献２】特開２００１年第３３５２５７号公報
【発明が解決しようとする課題】
上記特許文献１に開示されている路面排水処理設備によれば、国道あるいは高速自動車道等における道路区域から出る路面排水による汚水が流入して道路周辺の水田や河川等に害を与えることを防止することは可能であるが、処理槽が流入貯槽とその後段の整流貯槽とさらにその後段の流出貯槽から形成されているので処理設備全体はかなり大型であり、しかも、地上にその一部を露出して設置するので場所の選定が難しく、高速自動車道の法面であれば設置は可能であるが、市街地では設置不可能である。
【０００５】
また、上記特許文献２に開示されている排水処理装置によれば、比較的コンパクトであり、市街地の国道等の近傍に設置して、道路区域から出る路面排水の浄化は可能であるが、処理槽内が満水後は新たに路面排水の供給がない限り自律的な浄化処理ができない構造となっており、降雨初期の汚濁負荷が大きい初期フラッシュ排水のみを選択的に浄化する事は不可能である。
【０００６】
本発明の課題は、降雨時又は散水時の初期に発生する国道又は高速自動車道等の舗装道路の路面から流出する汚濁負荷が大きい初期フラッシュ排水のみを選択的に浄化処理する方法及び処理設備を提供することにある。
【０００７】
【課題を解決するための手段】
上記目的を達成する本発明の路面排水の処理方法は、道路側溝に流出した降雨排水の内で初期フラッシュ排水のみを選択的に分水する分水構造（以下、分水部という）を経て、地中に埋設した処理槽で処理し排水管への放流または地中放散することを特徴とするものである。
【０００８】
ここで、分水部とは従来の道路側溝排水ますふたを２重構造にしたものであり、降雨開始から処理対象容量までを排水ます外周部の集水溝に導入し、集水溝が満水になった後、初期フラッシュ排水以降の余水が２重ますの内側の既存排水口に導かれる構造となっている。
【０００９】
また、路面排水の処理方法は、初期フラッシュ排水を地中、望ましくは、歩道又は車道の下の地中に埋設した貯留部で処理するので、市街地であっても設置可能である。
【００１０】
また、本発明の路面排水の処理設備は、分水部と貯留部を通水パイプで連通し、降雨時又は散水時の初期に発生する国道又は高速自動車道等の舗装道路の汚濁濃度が高い初期フラッシュ排水を分水部から貯留部へ送る。通水パイプには適度な通水能力を持つように設定し、路面汚濁濃度が減少した後の路面排水は分水部２重ますの内側の既存排水口に導かれる。従い、当該発明において、分水部と貯留部間の通水パイプの通水能力の設定は設備の機能に対し重要な要件である。
【００１１】
上記の様に、通水パイプの通水能力の設定と共に、分水能力を向上させる方法として、通水パイプの初期フラッシュ排水貯留部側出口部の上部に混合阻止板を設け、分水能力を向上させた。当該混合阻止板は、貯留部の初期フラッシュ排水貯留部と分水部の集水溝の水面高さ付近（＝越流高さ付近）での流れを抑えることによって分水能力を向上させようとするものである。
【００１２】
また、分水能力を向上させるため、通水パイプ側の集水溝の２重ますの内側を高くした構造の越流阻止板を設けている。越流阻止板は初期フラッシュ排水を通水パイプを通じて貯留部へ送るにあたり、２重ます内側を通じて既存の排水溝へ初期フラッシュ排水が越流することを防ぐことにより、分水能力を向上させようとするものである。
【００１３】
同時に、分水部の集水溝の通水パイプ側の溝底部を中央の通水パイプ位置に向かって両側から通水パイプ部分が最も低くなるように、集水溝の底面を傾斜させ集水溝通水パイプ側勾配を持たせた。
これにより、初期フラッシュ排水の汚濁物質が速やかに、通水パイプを通って貯留部に流れ、集水溝が目詰まりを起こさないなど、メンテナンス上も有効であるような構成とした。
【００１４】
さらには、国道や高速道路は排水性を良くするため、一般に横断方向に対し道路中央から傾斜し、既存の排水ますの上面も傾斜しているが、その傾斜を利用し、分水部の集水溝については道路横断方向の傾斜に沿って傾斜させた。これにより、分水部全体に初期フラッシュ排水を速やかに通水パイプを通じて貯留部へ送ることができ、上記集水溝の通水パイプ側の底部傾斜とともに目詰まりを起こさないなど、メンテナンス上も有効な構成となる。
【００１５】
上記構成による処理方法は、道路側溝に流出した降雨排水の内で初期フラッシュ排水を分水するにおいて、道路側溝排水ますふたを２重構造とした分水部とし、降雨開始から処理対象容量までを分水部外周部の集水溝に導入し、集水溝が満水になった後、初期フラッシュ排水以降の余水が内側の既存排水口に導かれる分水構造よりなる路面排水の処理設備である。
【００１６】
また、分水部で分水された初期フラッシュ排水は分水部の集水溝に設けられた通水パイプを通じて、貯留部に送られ貯留部に充填された処理土壌にて浄化される構造よりなる処理設備である。
【００１７】
【発明の実施の形態】
道路側溝は様々な形状がある。しかし、側溝に取りつける装置が多種類あっては、それぞれのタイプ別に製造コストや施工にかかるコストが一定しないため、道路設計上不都合である。従い、これら各種の道路側溝に共通した要素として、道路と縁石でなす部分（歩道縁石の道路側の部分）に共通した構造体として、Ｌ型側溝ブロック又はＬφ型側溝ブロックと呼ばれるコンクリート製の側溝ブロックが比較的サイズ等の規格が明確化されており、様々な道路に対してもほぼ同じ構造、サイズのものが採用されている。Ｌ型側溝は側溝ブロックのみの成形であり、Ｌφ型側溝は側溝ブロックの下に排水管を有するものである。これら側溝ブロックに組み込むことの可能な路面排水処理装置を考案するのが製造施工上有利であると考えられ、当該側溝ブロックに組み込み可能な形状の排水処理施設を考案した。
【００１８】
ところで、路面排水処理設備は、「路面排水の初期フラッシュ排水を選択的に排水・浄化」するため、路面より流出する水を初期フラッシュ排水部分とそれ以降の部分に分水させる構造が必要である。流入する水を分水させる構造には、フロートを用いる、バルブなどの動力を用いる、スリットなどの分水構造を用いる方法などがあるが、「低コスト（建設、ランニングコスト共に）であること」「道路構造としての強度を持たせる」ことに考慮して、可動部をもたないことや動力を用いないことを重視して、上記スリットなどの分水構造を用いる方法を採用した。
【００１９】
スリットなど分水構造の基本的な考え方は、初期フラッシュ排水が集水される部分（以下集水溝という）を何らかの方法で持ち、その入口部分にスリット板など分水構造を配置するものである。分水構造には、集水溝が満水になった初期フラッシュ排水をその後の水が混合しにくい性能（分水性能）を持たせることとする。分水構造が分水性能を保つためには、分水部前後の水同士の接触面積が狭く、その狭い部分の長さ（厚さ、距離）ができるだけ長い方が有利であると考えられる。
【００２０】
分水構造には、図３に示す様に、２重ますタイプ（ａ）、２重側溝タイプ（ｂ）、ブロック下スリット（ｃ）、横分水（ｄ）、縦型（ｅ）などの構造が考えられる。本発明では下記理由によって、２重ますタイプ（ａ）を採用した。
【００２１】
分水構造の要件としては、十分な分水性能が得られるか、道路構造として強度は十分か、スペース的に狭い空間に収まるか、構造的に製造が容易であるか、目詰まり軽減対策が講じやすいか、設置上の制限は無いか、目詰まり除去や清掃などメンテナンスが容易かなど検討した。
【００２２】
その結果、２重側溝タイプ（ｂ）では構造が道路横断方向に長いため、施設面積・空間が広くなり、構造体製造の容易さにおいて不利であると考えられ、ブロック下スリット（ｃ）では、スリットが縁石に覆われている構造（道路に対して凹部となっている）により目詰まり物が堆積し易く、ゴミを除去しようとする場合、従来のブラシ車では洗浄が不充分である点で不利であり、横分水（ｄ）では僅かな傾斜を利用するため傾斜のある道路には設置できない点で不利であり、縦型（ｅ）では地下への設置のための施工の容易さで不利であるなどの問題がある。従い、２重ますタイプ（ａ）が最も実現性が高く、問題点の少ない構造であるとして採用した。
【００２３】
図１、図２に示す様に、当該発明の路面排水処理設備１は、初期フラッシュ排水とそれ以降の降雨水を分ける分水部２と初期フラッシュ排水を通水パイプを通じて取りこみ浄化する貯留部３とからなる。
【００２４】
分水部２は、車道側溝側に位置し、図１のように、２重ますタイプの路面排水処理設備１、すなわち、従来の排水ますふたを２重構造にし、外側に初期フラッシュ排水が流入するように集水溝４が設けられている。その集水溝４に溜まった初期フラッシュ排水は貯留部３側集水溝４の中央の通水パイプ５に向けて両側から通水パイプ５に流れやすい様に集水溝４の底部を相互傾斜した構造とし、通水パイプ５を通じて貯留部３の初期雨水貯留部６に流れる構造となっている。
【００２５】
上記選定した２重ますタイプの路面排水処理設備１の集水面積や分水部２に求められる通水能力について記述する。１つのますあたりの集水面積を設定するため、例として、滋賀県の代表的な道路２４箇所に、ます（グレーチング）の設置間隔と車道幅を測定することによって集水面積を調査した。同時に最も多く用いられている大きさのますについても調査した。その結果、集水面積の平均は６９．１４ｍ^２であり、この値を７０ｍ^２として貯留部３の初期フラッシュ排水貯留部６の容量、通水パイプ５の通水能力を決定するための数値として採用した。
【００２６】
グレーチング寸法は調査した２４ヶ所中１１ヶ所が６０ｃｍ×４０ｃｍのものであり、分水部２の集水部４の外形寸法としてこの寸法を採用した。また、植樹帯の幅は、調査した２４ヶ所中１４ヶ所に植樹帯が設けられており、この植樹帯の幅で最も小さいものの幅（横断方向）は７０ｃｍであり、初期降雨水貯蔵部を植樹帯の中に収めることが望ましいことから、当該寸法を貯留部３の初期フラッシュ排水貯留部６の横断方向の寸法として採用した。
【００２７】
次に、分水部２の通水能力についてであるが、路面排水中の汚濁物質は降雨初期に高濃度となり、降雨が継続するにつれて濃度は逓減する。このため、路面排水処理設備１は路面排水のうち特に高濃度である初期降雨水（２ｍｍ相当）を処理水として貯留部３の初期フラッシュ排水貯留部６へ導き、貯留部３下部の処理土壌充填部７の処理土壌により徐々に浄化するものである。（初期降雨水以降の降雨水は処理対象水とせず、従来の排水系（水路等）により公共用水域に排水される。）
【００２８】
路面排水処理設備１には初期フラッシュ排水とそれ以降の降雨水を分ける、分水部２の通水能力が極端に小さい場合、初期フラッシュ排水を貯留部６に導く際、通水能力を超える初期フラッシュ排水は貯留部６に導くことが出来ない。通水能力超過分の初期フラッシュ排水は処理対象水であるにもかかわらず、公共用水域へ排水されてしまう。このため、初期フラッシュ排水を貯留部へ導く通水能力は大きくしておく必要がある。しかしながら、過大な通水能力を持たせた場合、分水部２の大型化や分水能力の悪化（初期フラッシュ排水とその後の水が混合してしまう割合が増加する。）することが懸念される。
【００２９】
従い、路面排水処理設備１として必要な通水能力についてアメダスの時間降雨データ（例えば、この場合は滋賀県）をもとに必要とする通水能力を検討した。各局の降雨パターンによると最大降雨は概ね４０ｍｍ／時であり、この値を対応する通水能力の算出根拠として検討した。
【００３０】
各局の降雨パターンは様々であるが、４０ｍｍ／時クラスの豪雨前には降り始めの降雨があり、それによって、処理対象水（２ｍｍ）は貯留を終えている可能性がある。この点を考慮して必要な最小通水能力を２０ｍｍ／時とした。
以上のことから分水部の通水能力は２０〜４０ｍｍ／時の降雨に対応するものとした。
【００３１】
分水部２について図１、図２、表１を用いてさらに説明する。
表１

【００３２】
さらに降雨が継続し初期降雨水貯水量が表１−▲２▼に記載の様に１４０Ｌを超えた場合は、その２重ますの周囲の集水溝４の中側の壁を超えてそれ以降の降雨水は既存の道路側溝を経て、近辺の水田、河川湖沼等に流れる。
【００３３】
上記通水パイプ５を通じて、貯留部３は、歩道の植樹帯などに設けられ表１−▲２▼に記載の様に１４０Ｌの容積からなり、容器の半分の容積の処理土壌充填部７に処理土壌が充填され、その上に初期フラッシュ排水が通水パイプ５を通じて流入し、貯留部３の初期フラッシュ排水貯留部６に貯まった初期フラッシュ排水が一定時間を経て浄化され、処理土壌充填部７の底部側溝側面に設けられた処理水排水パイプ８を通じて既存の道路側溝に処理浄水が排水される。
【００３４】
また、通水パイプ５の初期フラッシュ排水貯留部６側出口部の上部に混合阻止板５１を設け、分水能力を向上させた。当該混合阻止板５１は、貯留部３の初期フラッシュ排水貯留部６と分水部２の集水溝４の水面高さ付近（＝越流高さ付近）での流れを抑えることによって分水能力を向上させようとするものである。
【００３５】
この混合阻止板５１を設けることにより、実験結果によれば、混合割合は改善割合として、１２．０〜１８．８％であり、混合阻止板５１は分水能力向上策として効果が認められる。
【００３６】
通水パイプ５の幅については、通水パイプの幅を１ｃｍから２ｃｍとした場合の混合割合は１．２％から１．６％に０．４％悪化した。従い、分水能力の観点からは通水パイプ幅は１ｃｍが望ましい。
【００３７】
しかし、通水パイプ５の幅が、１ｃｍの場合降雨２０ｍｍ／時相当の流入水は正常に初期フラッシュ排水貯留部６へ導入可能であったが、４０ｍｍ／時相当の流入水に対しては、流入水が集水溝４を満たし、通水パイプ５の通水能力の限界であることが分かった。また、通水パイプ５の幅が２ｃｍの場合は２０ｍｍ／時相当の流入水、４０ｍｍ／時相当の流入水ともに正常に初期降雨貯留部６へ初期フラッシュ排水を導くことが可能であった。従い、結果として通水パイプ幅は２ｃｍを採用する。
【００３８】
次に、上記各実験結果を総合的に評価するため、初期フラッシュ排水貯留後の降雨水としてさらに５０Ｌから１５０Ｌを通水させた場合の初期フラッシュ排水と初期フラッシュ排水貯留後降雨水との混合割合を調査した。
【００３９】
降雨強度２０ｍｍ／時相当、通水パイプ５は前述決定した様に、２ｃｍ、混合阻止板５１装着の状態で初期フラッシュ排水貯留後の降雨水として、５０Ｌ、２５０Ｌ、５００Ｌ、７５０Ｌ、１５００Ｌの水を分水部２の集水溝４へ流入させた。
【００４０】
尚、今回の連続通水試験では、より現実的な状況を作り出すため、道路の縦断方向の勾配として３％の勾配を持たせた。縦断方向の勾配による高低差のため流入水は流入側（上流側）から通水パイプ前を通過し、反対側（下流側）の集水溝から排水される様に構成して実施した。
【００４１】
試験結果は、図４に示すとおりであり、通水初期（５０Ｌ）以降は混合割合は一定しており、１５００Ｌ通水時（降雨２３．４ｍｍ）時の混合率は４．３％であった。
【００４２】
実際に当該発明の路面排水処理装置１を設置するにあたり、分水部２（通水パイプ５および集水溝４）での土砂による目詰まりが懸念されたため、分水部に土砂を堆積させその後５０Ｌの水を通水速度５ｍｍ／時相当、１０ｍｍ／時相当の速度で通水させ、分水部２の土砂が洗い流されるかどうかについて実験した。
【００４３】
分水部に堆積させる土砂には、実際の車道側溝の排水溝に堆積している土砂を用いた（充填土壌の上に堆積した土砂）。
【００４４】
堆積土砂の状況は、分水部２の素材のちがいにより若干の土砂堆積の可能性があるが、通水パイプ５や通水パイプ５付近の集水溝４では集水溝通水パイプ側勾配４６が設けられており土砂は通水により洗い流された。
【００４５】
前述のように道路側溝型路面排水処理設備１の分水部２は通水パイプ５の先端部に混合阻止板５１を装着し通水パイプ５の幅２ｃｍとしたモデルが適当と選択した。
【００４６】
本発明による道路側溝型路面排水処理設備１の分水部２の特徴を整理すると以下のとおりである。
【００４７】
分水能力としては、初期フラッシュ排水と初期フラッシュ排水後の降雨との混合率（分水能力）は１５００Ｌ通水（降雨２３．４ｍｍ相当）で４．３％である。通水能力としては、降雨４０ｍｍ／時相当の降雨流入水を初期フラッシュ排水貯留部へ導くことが可能である。
【００４８】
また、下記理由により、メンテナンス性にもすぐれる。通水パイプ部５ならびに通水パイプ５付近の集水溝４に集水溝通水パイプ側勾配４６を設けており、これによって通水パイプ５付近の土砂は降雨によって洗い流される。この為、土砂により通水パイプ５が詰まる可能性は低い。また、万一、通水パイプ５や集水溝４が土砂によって閉塞した場合でも路面排水は既存の排水口へオーバーフローし道路からは排水されることから、道路の冠水などの悪影響がおよぶ可能性は無い。
【００４９】
既存の排水ますふたに使用されているグレーチングの設置寸法の内側に集水構造を収めていることから、平面的には現状と同じ設置スペースである。深さ方向には、貯留部３の深さによるが、分水部２のみの深さは路面から１７ｃｍと浅くて済む。尚、分水部は道路の横断勾配４５を想定して、５％傾斜させて実験を行った。
【００５０】
【発明の効果】
本発明の路面排水の処理方法は、道路側溝に流出した降雨排水の内で初期フラッシュ排水のみを選択的に分水する分水部を経て、地中に埋設した処理槽で処理し排水管への放流または地中放散することを特徴とするものである。
【００５１】
ここで、分水部とは従来の道路側溝排水ますふたを２重構造にしたものであり、降雨開始から処理対象容量までを排水ます外周部の排水溝に導入し、集水溝が満水になった後、初期フラッシュ排水以降の余水が内側の既存排水口に導くことができる。
【００５２】
また、路面排水の処理方法は、初期フラッシュ排水を地中、望ましくは、歩道又は車道の下の地中に埋設した処理槽で処理するので、市街地であっても設置可能である。
【００５３】
また、本発明の路面排水の処理設備は、分水部と貯留部を通水能力を最適に設定した通水パイプで連通し、降雨時又は散水時の初期に発生する国道又は高速自動車道等の舗装道路の汚濁濃度が高い初期フラッシュ排水を分水部から貯留部へ送る。汚濁濃度が減少した後の排水は分水部２重ますの内側の既存排水口を通じて排水することができる。
【００５４】
分水能力を向上させる方法として、通水パイプの初期フラッシュ排水貯留部出口部の上部に貯留部の初期フラッシュ排水貯留部と分水部の集水溝の水面高さ付近（＝越流高さ付近）での流れを抑える混合阻止板を設け、分水能力を向上させている。
【００５５】
また、分水能力を向上させるため、通水パイプ側の集水溝の２重ますの内側を高くした越流阻止板を設けている。越流阻止板は初期フラッシュ排水を通水パイプを通じて貯留部へ送るにあたり、２重ます内側を通じて既存の排水口へ初期フラッシュ排水が越流することを防ぐことにより、分水能力を向上することができる。
【００５６】
同時に、分水部の集水溝の通水パイプ側の溝を中央の通水パイプ位置に向かって両側から通水パイプ部分が最も低くなるように、集水溝の底面を傾斜させ、初期フラッシュ排水の汚濁物質が速やかに、通水パイプを通って貯留部に流れ、集水溝が目詰まりを起こさないなど、メンテナンス上も有効である。
【００５７】
さらには、国道や高速道路は排水性を良くするため、一般に横断方向に対し道路中央から傾斜し、既存の排水ますの上面も傾斜しているが、その傾斜を利用し、分水部の集水溝については道路横断方向の傾斜に沿って傾斜させた。これにより、分水部全体に初期フラッシュ排水を速やかに通水パイプを通じて貯留部へ送ることができ、上記集水溝の通水パイプ側の底部傾斜とともに目詰まりを起こさないなど、メンテナンス上も有効である。
【図面の簡単な説明】
【図１】本発明の路面排水処理設備を示す概略構成図である。
【図２】本発明の路面排水処理設備の分水部の概略構成図である。
【図３】路面排水における一般的分水方式を示す図である。
【図４】本発明における分水連続通水試験結果を表す図である。
【符号の説明】
１路面排水処理設備
２分水部
３貯留部
４集水溝
５通水パイプ
６初期フラッシュ排水貯留部
７処理土壌充填部
８処理水排水パイプ
４１越流阻止板
４５道路の横断勾配
４６集水溝通水パイプ側勾配
５１混合阻止板[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a treatment method and a treatment facility for high-concentration drainage (hereinafter referred to as initial flush drainage) on a pavement road surface such as a national road or a highway, which occurs early in rainfall or when watering.
[0002]
[Prior art]
On a road surface such as a national highway or a highway, in addition to earth and sand, dust, and the like, particulate matter mainly emitted from a running vehicle is scattered and distributed over the entire road. Conventionally, road surface cleaning is carried out manually or by a movable vehicle using a power source such as a brush or vacuum.However, this is not sufficient, and the above substances are drained from the road surface during rainfall or water sprinkling to form a road gutter. After that, it flows into nearby paddy fields, rivers, lakes and marshes, causing water quality deterioration.
[0003]
At present, there is an emission standard or agriculture water standard for the quality of water discharged from specific business facilities into public water bodies, but there is no legal regulation on road drainage. In recent years, water quality of rivers, lakes and marshes has been regarded as a problem due to increasing interest in environmental problems, and treatment of road surface drainage is becoming indispensable. Therefore, there is disclosed a technology related to road surface drainage treatment in which road drainage collected from a road side gutter is bypassed and drainage of road surface drainage is purified by a treatment tank and treated water is returned to the drainage ditch (for example, Patent Reference 1). Also disclosed is a technology relating to a wastewater treatment device that purifies road surface wastewater and discharges it with a treatment device (a plurality of treatment tanks having an open upper end and a communicated lower end) similarly installed near a road (for example, See Patent Document 2.).
[0004]
[Patent Document 1] JP-A-2001-49647 [Patent Document 2] JP-A-2001-335257 [Problems to be Solved by the Invention]
According to the road surface wastewater treatment equipment disclosed in Patent Document 1, it is possible to prevent sewage caused by road surface drainage from a road area on a national highway or a highway, etc., from flowing into and damaging paddy fields and rivers around the road. However, the processing equipment is quite large because the processing tank is composed of an inflow storage tank, a rectification storage tank in the subsequent stage, and an outflow storage tank in the subsequent stage, and a part of the processing equipment is exposed on the ground. It is difficult to select a place because it is installed on the road, and it can be installed on the slope of a highway, but cannot be installed in an urban area.
[0005]
Further, according to the wastewater treatment apparatus disclosed in Patent Document 2, it is relatively compact, and can be installed near a national road or the like in an urban area to purify road surface wastewater from a road area. After the tank is full, autonomous purification treatment cannot be performed unless new surface drainage is supplied, and it is not possible to selectively purify only the initial flash drainage that has a large pollution load at the beginning of rainfall. is there.
[0006]
An object of the present invention is to provide a method and a treatment facility for selectively purifying only initial flash drainage having a large pollution load flowing out of a road surface of a paved road such as a national road or an expressway that occurs at the beginning of rainfall or sprinkling. To provide.
[0007]
[Means for Solving the Problems]
The method for treating road surface drainage of the present invention that achieves the above object includes a water separation structure (hereinafter, referred to as a water separation unit) that selectively separates only initial flush drainage from rainfall drainage that has flown into a road gutter, It is characterized in that it is treated in a treatment tank buried underground and discharged to a drainpipe or discharged underground.
[0008]
Here, the diversion section is a conventional double-sided drainage gutter, which drains water from the start of rainfall to the capacity to be treated. After that, the spill water after the initial flush drainage is led to the existing drain outlet inside the double muffle.
[0009]
In addition, the method for treating road surface drainage is that the initial flush drainage is treated in the ground, desirably in a reservoir buried underground beside a sidewalk or a roadway, so that it can be installed even in an urban area.
[0010]
In addition, the road surface wastewater treatment equipment of the present invention communicates the water diversion section and the storage section with a water pipe, and has a high pollutant concentration on a pavement road such as a national highway or a highway, which occurs at an early stage of rainfall or watering. The initial flush drainage is sent from the diversion section to the storage section. The water pipe is set to have an adequate water flow capacity, and the road surface drainage after the road surface pollution concentration is reduced is led to the existing drainage port inside the double diversion section. Therefore, in the present invention, the setting of the water flow capacity of the water pipe between the water diversion unit and the storage unit is an important requirement for the function of the equipment.
[0011]
As described above, as well as setting the water flow capacity of the water flow pipe, as a method of improving the water flow capacity, a mixing prevention plate is provided at the upper part of the initial flush drainage storage section side outlet of the water flow pipe, and the water flow capacity is improved. Improved. The mixing prevention plate is intended to improve the water separation ability by suppressing the flow near the water surface height (= near the overflow height) of the initial flush drainage storage part of the storage part and the water collecting groove of the water separation part. To do.
[0012]
In addition, in order to improve the water distribution capacity, an overflow blocking plate having a structure in which the inside of the double trough of the water collecting groove on the side of the water pipe is raised is provided. The overflow prevention plate is designed to improve the water separation capacity by preventing the initial flush drainage from overflowing to the existing drainage ditch through the inside of the double pit when sending the initial flush drainage to the reservoir through the water pipe. To do.
[0013]
At the same time, the bottom of the water collecting ditches is inclined so that the bottom of the water collecting ditches on the water diversion pipe side of the water diversion part toward the center water diversion pipe position is lowest from both sides. The groove has a slope on the water pipe side.
Thereby, the contaminants of the initial flush drainage quickly flow through the water flow pipe to the storage section, and the water collecting groove is not clogged, which is effective for maintenance.
[0014]
Furthermore, national roads and expressways are generally inclined from the center of the road in the transverse direction and the upper surface of the existing drain basin is also inclined in order to improve drainage. The ditches were inclined along the cross-road direction. As a result, the initial flush drainage can be quickly sent to the storage section through the water flow pipe to the entire water diversion section, and it is effective for maintenance, such as not causing clogging with the bottom inclination of the water collection groove on the water flow pipe side. Configuration.
[0015]
The method of treatment according to the above configuration is to separate the initial flush drainage from the rainwater drained into the road gutter. It is introduced into the ditches on the outer periphery of the diversion part, and after the ditches are filled, the surplus water after the initial flush drainage is led to the existing drain inside the road, and the road surface drainage treatment equipment has a diversion structure. is there.
[0016]
In addition, the initial flush drainage water separated in the water separation part is sent to the storage part through a water pipe provided in the water collecting groove of the water separation part, and is purified by the treated soil filled in the storage part. Processing equipment.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Road gutters have various shapes. However, if there are many types of devices to be attached to the gutters, manufacturing costs and construction costs are not constant for each type, which is inconvenient in road design. Accordingly, a concrete gutter called an L-shaped gutter block or an Lφ-shaped gutter block as an element common to these various road gutters is a structure common to a portion formed by a road and a curb (a portion of the sidewalk curb on the road side). Standards such as the size of the blocks are comparatively clarified, and almost the same structure and size are adopted for various roads. The L-shaped side groove is formed of only the side groove block, and the Lφ-side groove has a drain pipe below the side groove block. It is considered that devising a road surface wastewater treatment device that can be incorporated into these gutter blocks is advantageous in terms of manufacturing and construction, and a wastewater treatment facility that can be incorporated into the gutter block has been devised.
[0018]
By the way, in order to "selectively drain and purify the initial flush drainage of road surface drainage", the road surface wastewater treatment facility needs a structure that divides water flowing out of the road surface into an initial flush drainage portion and a portion after that. . As a structure for separating the inflowing water, there are a method using a float, a method using a power such as a valve, and a method using a water separation structure such as a slit. However, “the cost is low (both construction and running costs)”. In consideration of "giving strength as a road structure", a method using a water diversion structure such as the above-mentioned slit was adopted with emphasis on not having movable parts and not using power.
[0019]
The basic idea of a water diversion structure such as a slit is to have a part where the initial flush drainage is collected (hereinafter referred to as a water collection ditch) in some way and arrange a water diversion structure such as a slit plate at the entrance. . The water separation structure shall have a performance (water separation performance) that makes it difficult for the subsequent flush water to be mixed with the initial flush drainage in which the water collecting groove is full. In order for the water separation structure to maintain the water separation performance, it is considered advantageous that the contact area between the water before and after the water separation part is small and the length (thickness, distance) of the narrow part is as long as possible.
[0020]
As shown in Fig. 3, the water diversion structure includes a double mullet type (a), a double side groove type (b), a block lower slit (c), a horizontal water diversion (d), and a vertical type (e). Structure is conceivable. In the present invention, the double square type (a) is adopted for the following reason.
[0021]
The requirements for the water diversion structure include whether sufficient water diversion performance can be obtained, whether the road structure has sufficient strength, whether it fits in a narrow space, whether the structure is easy to manufacture, and measures to reduce clogging. We examined whether it is easy to take, whether there is no restriction on installation, and whether maintenance such as clogging removal and cleaning is easy.
[0022]
As a result, since the structure is long in the cross-road direction in the double gutter type (b), the facility area and space are widened, which is considered to be disadvantageous in the ease of manufacturing the structure. The structure in which the slit is covered with a curb (it is a recess with respect to the road) makes it easy for clogs to accumulate, and when trying to remove dirt, the conventional brush wheel is insufficiently cleaned. It is disadvantageous in that the horizontal diversion (d) uses a slight slope and cannot be installed on a sloped road. The vertical type (e) has the disadvantage of easy construction for installation underground. There are problems such as disadvantages. Therefore, the double-mass type (a) was adopted because it has the highest feasibility and has few problems.
[0023]
As shown in FIGS. 1 and 2, the road surface wastewater treatment equipment 1 of the present invention includes a water diversion unit 2 that separates initial flush drainage and subsequent rainwater, and a storage unit 3 that takes in and purifies the initial flush drainage through a water pipe. Consists of
[0024]
The water diversion part 2 is located on the side of the roadway ditches. As shown in Fig. 1, the double drain type road surface drainage treatment equipment 1, that is, the conventional drain lid is made into a double structure, and the initial flush drainage flows into the outside. Water collecting groove 4 is provided. The initial flush drainage accumulated in the water collecting groove 4 is inclined to the bottom of the water collecting groove 4 so that it easily flows into the water pipe 5 from both sides toward the central water pipe 5 of the water collecting groove 4 on the storage section 3 side. The structure is such that it flows into the initial rainwater storage unit 6 of the storage unit 3 through the water pipe 5.
[0025]
The water collecting area and the water flow capacity required for the water diversion section 2 of the above-mentioned double-mass type road surface wastewater treatment equipment 1 will be described. In order to set the catchment area per square, as an example, the catchment area was investigated by measuring the installation intervals and the width of the lane at 24 typical roads in Shiga Prefecture. At the same time, the most commonly used squeeze was investigated. As a result, the average of the catchment area is 69.14M ^2, the capacity of the initial flash drainage reservoir 6 of the reservoir 3 this value as the 70m ^2, as a number for determining the water flow capability of the water flow pipe 5 Adopted.
[0026]
The grating dimensions were 60 cm × 40 cm at 11 of the 24 locations examined, and this dimension was adopted as the outer dimension of the water collecting section 4 of the water dividing section 2. In addition, the width of the tree planting zone is provided at 14 of the 24 surveyed sites, and the width of the smallest tree planting zone (transverse direction) is 70 cm. Since it is desirable to fit in the band, this dimension was adopted as the dimension of the initial flush drainage storage section 6 of the storage section 3 in the transverse direction.
[0027]
Next, regarding the water flow capacity of the water diversion unit 2, the concentration of pollutants in road surface drainage becomes high at the beginning of rainfall, and the concentration gradually decreases as rainfall continues. For this reason, the road surface drainage treatment equipment 1 guides the initial rainwater (equivalent to 2 mm) having a particularly high concentration among the road surface drainage to the initial flush drainage storage unit 6 of the storage unit 3 as the treated water, and fills the processing soil under the storage unit 3 with the treated soil. It purifies gradually by the treated soil of the part 7. (Rainwater after the initial rainwater is not treated as water to be treated, but is drained to public water bodies by conventional drainage systems (waterways, etc.).)
[0028]
The road surface wastewater treatment equipment 1 separates the initial flush drainage and the subsequent rainwater. When the water flow capacity of the water separation unit 2 is extremely small, when the initial flash wastewater is led to the storage unit 6, the initial flush wastewater exceeds the water flow capacity. The flush drainage cannot be led to the storage unit 6. The initial flush drainage that exceeds the water flow capacity is drained to public water bodies even though it is the target water. For this reason, it is necessary to increase the water flow capacity for guiding the initial flush drainage to the storage unit. However, if the water supply capacity is excessively large, there is a concern that the water separation section 2 may be enlarged and the water separation capacity may be deteriorated (the ratio of mixing of the initial flush drainage and the subsequent water increases). You.
[0029]
Accordingly, the required water flow capacity of the road surface wastewater treatment equipment 1 was examined based on AMeDAS time rainfall data (for example, in this case, Shiga Prefecture). According to the rainfall pattern of each station, the maximum rainfall was approximately 40 mm / hour, and this value was examined as the basis for calculating the corresponding water flow capacity.
[0030]
Although the rainfall pattern of each station is various, there is a rainfall that begins to fall before the heavy rain in the class of 40 mm / hour, so that the water to be treated (2 mm) may have finished storing. In consideration of this point, the necessary minimum water flow capacity was set to 20 mm / hour.
From the above, the water flow capacity of the water separation section was set to correspond to rainfall of 20 to 40 mm / hour.
[0031]
The water dividing section 2 will be further described with reference to FIGS.
Table 1

[0032]
Further, if the rainfall continues and the initial rainwater storage volume exceeds 140 L as shown in Table 1- (2), the rainwater will exceed the middle wall of the drainage ditch 4 around the double truss and thereafter. Rainwater flows through existing road gutters into nearby paddy fields, rivers and lakes.
[0033]
Through the water pipe 5, the storage unit 3 is provided in a tree-planting zone on the sidewalk or the like, and has a volume of 140 L as shown in Table 1- (2), and is processed into the processing soil filling unit 7 having a half volume of the container. The soil is filled, the initial flush drainage flows in through the water pipe 5, and the initial flush drainage stored in the initial flush drainage storage section 6 of the storage section 3 is purified after a certain period of time, and The treated purified water is drained to an existing road gutter through a treated water drainage pipe 8 provided on the side of the bottom gutter.
[0034]
Further, a mixing prevention plate 51 is provided above the outlet of the water pipe 5 on the side of the initial flush drainage storage section 6 to improve the water separation capacity. The mixing prevention plate 51 suppresses the flow near the water level of the initial flush drainage storage part 6 of the storage part 3 and the water collecting groove 4 of the water separation part 2 (= around the overflow height), thereby enabling the water separation ability. Is to be improved.
[0035]
According to the experimental results, by providing the mixing prevention plate 51, the mixing ratio is 12.0 to 18.8% as the improvement ratio, and the mixing prevention plate 51 is effective as a water separation ability improving measure.
[0036]
As for the width of the water pipe 5, the mixing ratio when the width of the water pipe was 1 cm to 2 cm was deteriorated by 0.4% from 1.2% to 1.6%. Therefore, the width of the water pipe is preferably 1 cm from the viewpoint of the water separation capacity.
[0037]
However, when the width of the water pipe 5 is 1 cm, the inflow water equivalent to rainfall of 20 mm / hour can be normally introduced into the initial flush drainage storage unit 6. However, for the inflow water equivalent to 40 mm / hour, It was found that the inflow water filled the catchment groove 4 and was at the limit of the water flow capacity of the water flow pipe 5. Also, when the width of the water flow pipe 5 was 2 cm, it was possible to normally guide the initial flush drainage to the initial rainfall storage part 6 with both the inflow water equivalent to 20 mm / hour and the inflow water equivalent to 40 mm / hour. Therefore, as a result, the width of the water pipe is 2 cm.
[0038]
Next, in order to comprehensively evaluate the results of the above experiments, the mixing ratio of the initial flash drainage and the rainwater after initial flash drainage storage when 50 L to 150 L of water was further passed as rainwater after initial flash drainage storage. investigated.
[0039]
Assuming that the rainfall intensity is 20 mm / h, the water pipe 5 is 2 cm, and 50 L, 250 L, 500 L, 750 L, and 1500 L of water are collected as the rain water after the initial flush drainage storage with the mixing prevention plate 51 attached as described above. The water flowed into the water collecting groove 4 of the water dividing section 2.
[0040]
In this continuous water flow test, a gradient of 3% was provided as a gradient in the longitudinal direction of the road in order to create a more realistic situation. The inflow water was passed from the inflow side (upstream side) to the front of the water pipe and drained from the opposite (downstream side) water collection channel due to the vertical difference due to the vertical gradient.
[0041]
The test results are as shown in FIG. 4, and the mixing ratio is constant after the initial flow of water (50 L), and the mixing ratio at the time of 1500 L water flow (rainfall 23.4 mm) was 4.3%. .
[0042]
When the road surface wastewater treatment apparatus 1 of the present invention was actually installed, clogging with sediment in the water diversion part 2 (the water pipe 5 and the water collecting groove 4) was concerned, and sediment was deposited on the water diversion part. 50 L of water was passed at a water flow rate of 5 mm / hour, which was equivalent to 10 mm / hour, and an experiment was conducted as to whether or not the soil in the water separation unit 2 was washed away.
[0043]
As the sediment deposited in the diversion section, the sediment deposited in the actual drainage ditches of the roadway ditches was used (sediment deposited on the filled soil).
[0044]
There is a possibility that the sediment is slightly deposited due to the difference in the material of the water diversion unit 2. However, in the water pipe 5 and the water collecting groove 4 near the water pipe 5, the water collecting groove and the water pipe 4 slope 46. The sediment was washed away by passing water.
[0045]
As described above, the water diversion part 2 of the road side groove type road surface drainage treatment equipment 1 was selected to be a model in which the mixing prevention plate 51 was attached to the tip of the water flow pipe 5 and the width of the water flow pipe 5 was 2 cm.
[0046]
The features of the water diversion unit 2 of the road-side ditch-type road surface wastewater treatment equipment 1 according to the present invention are summarized as follows.
[0047]
As for the water separation capacity, the mixing ratio (water separation capacity) of the initial flush drainage and the rainfall after the initial flush drainage is 4.3% at 1500 L water flow (equivalent to rainfall of 23.4 mm). As for the water flow capacity, it is possible to guide rainfall inflow water equivalent to rainfall of 40 mm / hour to the initial flush drainage storage section.
[0048]
In addition, it is excellent in maintainability for the following reasons. The water collecting pipe part 5 and the water collecting groove 4 near the water flowing pipe 5 are provided with a water collecting groove water flowing pipe side gradient 46, so that the sediment near the water flowing pipe 5 is washed away by rainfall. For this reason, the possibility that the water pipe 5 is clogged with earth and sand is low. Also, even if the water pipes 5 and the catchment ditch 4 are blocked by earth and sand, road surface drainage overflows to the existing drainage outlet and is drained from the road, which may have adverse effects such as flooding of the road. There is no.
[0049]
Since the water collection structure is housed inside the installation dimensions of the grating used for the existing drainage lid, the installation space is the same as the current situation in plan. In the depth direction, depending on the depth of the storage part 3, the depth of the water diversion part 2 only needs to be as small as 17 cm from the road surface. The experiment was conducted with the water diversion section inclined at 5%, assuming a cross slope 45 of the road.
[0050]
【The invention's effect】
The method of treating road surface drainage according to the present invention includes a drainage section that selectively separates only initial flash drainage from rainfall drainage that has flown into a road gutter, and then treats the wastewater in a treatment tank buried underground to a drain pipe. Or under the ground.
[0051]
Here, the diversion section is a conventional road-side drainage drain lid with a double structure. The drainage from the start of rainfall to the capacity to be treated is introduced into the outer peripheral drainage ditches, and the drainage ditches are filled with water. After that, the excess water after the initial flush drainage can be led to the existing drain inside.
[0052]
In addition, the method of treating road surface drainage is that the initial flush drainage is treated in a treatment tank buried in the ground, desirably in the ground under a sidewalk or a roadway, so that it can be installed even in an urban area.
[0053]
Further, the road surface drainage treatment facility of the present invention communicates with a water diversion section and a storage section through a water flow pipe having an optimally set water flow capacity, and a national road or a high-speed motorway or the like which is generated at the initial stage of rainfall or watering. From the diversion section to the storage section. After the pollutant concentration is reduced, the wastewater can be drained through the existing drain inside the double diversion basin.
[0054]
As a method to improve the water separation capacity, the initial flush drainage storage part of the storage section and the water surface height of the catchment groove of the water separation part are placed above the outlet of the initial flush drainage storage part of the water pipe (= overflow height) (In the vicinity), a mixing prevention plate is provided to improve the water separation capacity.
[0055]
In order to improve the water distribution capacity, an overflow blocking plate is provided in which the inside of the double trough of the water collecting groove on the water flow pipe side is raised. When the overflow prevention plate sends the initial flush drainage to the reservoir through the water pipe, it can improve the water separation capacity by preventing the initial flush drainage from overflowing to the existing drain through the inside of the double pit. it can.
[0056]
At the same time, the bottom of the drainage channel is inclined so that the drainage pipe portion of the drainage channel in the diversion section is the lowest from both sides toward the center drainage pipe position, and the initial flushing is performed. The pollutants in the wastewater quickly flow through the water pipe to the storage part, and the drainage ditch is not clogged, which is effective for maintenance.
[0057]
Furthermore, in order to improve drainage, national roads and expressways are generally inclined from the center of the road in the transverse direction, and the upper surface of the existing drainage basin is also inclined. The ditches were inclined along the cross-road direction. As a result, the initial flush drainage can be quickly sent to the storage section through the water flow pipe to the entire water diversion section, and it is effective for maintenance, such as not causing clogging with the bottom inclination of the water collection groove on the water flow pipe side. It is.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a road surface wastewater treatment facility of the present invention.
FIG. 2 is a schematic configuration diagram of a water diversion section of the road surface wastewater treatment equipment of the present invention.
FIG. 3 is a diagram showing a general water distribution method for road surface drainage.
FIG. 4 is a diagram showing the results of a continuous water separation test in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Road surface drainage treatment equipment 2 Water separation part 3 Storage part 4 Water collecting groove 5 Water passage pipe 6 Initial flush drainage storage part 7 Treated soil filling part 8 Treated water drainage pipe 41 Overflow prevention plate 45 Crossing slope 46 of road Water pipe side gradient 51 Mixing prevention plate

Claims

A method for treating road surface drainage, comprising separating initial flush drainage of rainwater drainage that has flowed into a road gutter.

The method for treating road surface drainage according to claim 1, wherein a water diversion unit comprises a double basin in separating the initial flush drainage of rainwater drainage flowing out into the road gutter.

3. The method according to claim 1, wherein after the water collecting ditches of the water diversion section are filled with the initial flush drainage, surplus water after the initial flush drainage is guided to a drain inside the water collecting ditches. 4. Road drainage treatment method.

The road surface drainage treatment method according to any one of claims 1 to 3, wherein the initial flush drainage is purified in the storage unit.

The method for treating road surface drainage according to any one of claims 1 to 4, wherein the water diversion part and the storage part are communicated by a water pipe.

The method for treating road surface drainage according to any one of claims 1 to 5, wherein a mixing prevention plate is provided at a tip of the water pipe.

The treatment of road surface drainage according to any one of claims 1 to 6, wherein an overflow prevention plate is provided on the water pipe side of the water collection channel in the water distribution section and on the inner drain channel side of the water collection channel. Method.

The method for treating road surface drainage according to any one of claims 1 to 7, wherein a bottom portion of the water collecting groove of the water separating section on the water pipe side is inclined from both sides toward the water pipe.

The method for treating road surface drainage according to any one of claims 1 to 8, wherein the water diversion part is inclined in accordance with the direction of the cross slope of the road.

Road surface drainage treatment equipment characterized by a structure that separates the initial flush drainage from the rainfall drainage that has flowed into the road gutter.

11. The road surface drainage treatment equipment according to claim 10, wherein the water separation unit has a double-layered structure in separating the initial flush drainage from the rainfall drainage that has flowed into the road gutter.

12. The structure according to claim 10, wherein after the water collecting ditches of the water diversion part are filled with the initial flush drainage, surplus water after the initial flush drainage is guided to a drain inside the water collecting ditches. Road surface drainage treatment equipment according to (1).

The road surface drainage treatment facility according to any one of claims 10 to 12, wherein the initial flush drainage is configured to be purified in the storage unit.

The road surface drainage treatment equipment according to any one of claims 10 to 13, wherein the water separation unit and the storage unit are connected to each other by a water pipe.

The road surface drainage treatment equipment according to any one of claims 10 to 14, wherein a mixing prevention plate is provided at a tip of the water pipe.

The road surface drainage treatment according to any one of claims 10 to 15, wherein an overflow prevention plate is provided on the water flow pipe side of the water collection groove of the water distribution section and on the inner drainage groove side of the water collection groove. Facility.

The road surface drainage treatment equipment according to any one of claims 10 to 16, wherein the water collecting pipe of the water diversion part has a structure in which a bottom portion on a water pipe side is inclined from both sides toward the water pipe. .

The road surface drainage treatment equipment according to any one of claims 10 to 17, wherein the water diversion part is configured to be inclined in accordance with the cross slope direction of the road.

In diversion of the initial flush drainage of rainwater drainage that has flowed into the road ditches, the road ditches drainage lid has a double diversion structure, and the water ditches on the outer periphery of the diversion part from the start of rainfall to the capacity to be treated Road drainage treatment equipment that has a water diversion structure in which water after the initial flush drainage is led to the existing drainage outlet inside after the catchment canal is full.

The initial flush drainage water separated in the water separation part is sent to the storage part through the water pipe provided in the water collecting groove of the water separation part, and is purified by the treated soil filled in the storage part. The road surface drainage treatment facility according to claim 19, wherein: