JP4674188B2 - Primary treatment method for combined sewage - Google Patents

Primary treatment method for combined sewage Download PDF

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JP4674188B2
JP4674188B2 JP2006173602A JP2006173602A JP4674188B2 JP 4674188 B2 JP4674188 B2 JP 4674188B2 JP 2006173602 A JP2006173602 A JP 2006173602A JP 2006173602 A JP2006173602 A JP 2006173602A JP 4674188 B2 JP4674188 B2 JP 4674188B2
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JP2008000697A (en
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枝直 ▲高▼柳
益司 伊賀
芳彦 中山
篤 宮田
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Metawater Co Ltd
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Description

本発明は、汚水と雨水が合流して下水処理場に流入する合流式下水の一次処理方法に関するものである。   The present invention relates to a primary treatment method for combined sewage in which sewage and rainwater merge and flow into a sewage treatment plant.

従来の下水処理場は、図5に示すように沈砂池1、最初沈殿池2、反応槽3、最終沈殿池4を備えたものであり、沈砂池1と最初沈殿池2において流入水中の夾雑物やSSを分離し、反応槽3では生物反応を利用してBODを除去し、最終沈殿池4では生物反応により生じたフロック等を沈降分離したうえ、処理水を河川や海に放流している。下水処理場は設計水量Q(晴天時日最大流入水量)を定めており、流入水量がQ以下の場合には上記した通常の高級処理を行っている。   As shown in FIG. 5, the conventional sewage treatment plant includes a sand basin 1, a first sedimentation basin 2, a reaction tank 3, and a final sedimentation basin 4. In the reaction tank 3, biological reaction is used to remove BOD, and in the final sedimentation tank 4, flocs generated by biological reaction are settled and separated, and the treated water is discharged into rivers and seas. Yes. The sewage treatment plant defines a design water amount Q (the maximum inflow water amount on a clear day), and when the inflow water amount is Q or less, the above-described normal high-level treatment is performed.

ところが合流式の下水処理場では、雨天時には雨水の合流によって流入水量が大幅に増加する。このため図5に示すように流入水量のうちQのみを反応槽3と最終沈殿池4により生物処理し、Qを超過し3Qまでの部分は沈砂池1、最初沈殿池2を通して簡易処理しただけで放流し、3Q超過分はそのまま放流する方法が採用されていた。しかしこの簡易処理におけるSS除去率は30%程度に過ぎないため、従来法では雨天時には処理が不十分な大量の下水が河川や海に放流され、水域環境の悪化を招いていた。   However, in the combined sewage treatment plant, the amount of inflow water greatly increases due to the combination of rainwater when it rains. For this reason, as shown in FIG. 5, only Q of the influent water is biologically treated by the reaction tank 3 and the final settling basin 4, and the portion exceeding Q and up to 3Q is simply treated through the sand basin 1 and the first settling basin 2. The method was used, and the excess of 3Q was released as it was. However, since the SS removal rate in this simple treatment is only about 30%, a large amount of sewage that is insufficiently treated in the case of rain in the conventional method is discharged into a river or the sea, resulting in deterioration of the water environment.

そこで特許文献1に示すように、従来の最初沈殿池2の設置スペースに見掛け比重が0.1〜0.4の浮上ろ材を充填した高速ろ過槽を設置し、晴天時にも雨天時にも流入下水をこの高速ろ過槽に導いてSSを除去する合流式下水の処理方法が開発されている。この高速ろ過槽は1000m/日以上のろ過速度においても70%以上のSS除去率を達成できるため、雨天時における放流水質の改善効果が大きい。ところが大規模な実験設備を作成して実用化試験を重ねた結果、次の2つの問題が明らかになった。   Therefore, as shown in Patent Document 1, a high-speed filtration tank filled with a floating filter medium with an apparent specific gravity of 0.1 to 0.4 is installed in the installation space of the conventional first sedimentation basin 2, and the inflow sewage in fine weather and rainy weather. A method for treating combined sewage in which SS is removed by introducing the gas into the high-speed filtration tank has been developed. Since this high-speed filtration tank can achieve an SS removal rate of 70% or more even at a filtration rate of 1000 m / day or more, the effect of improving the quality of discharged water during rainy weather is great. However, as a result of creating a large-scale experimental facility and conducting practical tests, the following two problems became clear.

第1に、雨天時にも晴天時と同様に反応槽3と最終沈殿池4はQのみの水量を処理し、残部は生物処理されずに放流されているため、従来に比較して改善されたものの、なお雨天時における放流水の汚濁負荷は、晴天時に比べてかなり高い。第2に、高速ろ過槽の逆洗は晴天時にも雨天時にも、ろ材充填層のろ過抵抗が設定圧(例えば4kPa)に達した時に行っていたが、晴天時には雨天時よりも流入水中の微細粒子の比率が高く、ろ材充填層の奥まで侵入して逆洗効果が低下する。従って晴天時にはより効果的な逆洗方法を確立する必要がある。
特開2003−136088号公報
First, the reaction tank 3 and the final sedimentation basin 4 treated only with water in the rainy weather as well as in the clear weather, and the remainder was discharged without being biologically treated. However, the pollution load of discharged water in rainy weather is considerably higher than that in sunny weather. Secondly, backwashing of the high-speed filtration tank was performed when the filtration resistance of the filter medium packed bed reached a set pressure (for example, 4 kPa) in fine weather and rainy weather. The ratio of the particles is high, and the backwashing effect is lowered by intruding into the depth of the filter medium packed bed. Therefore, it is necessary to establish a more effective backwash method in fine weather.
JP 2003-136088 A

本発明は上記した従来の問題点を解決し、雨天時における放流水の汚濁負荷を更に低減でき、晴天時にも確実にろ材充填層を逆洗することができる合流式下水の一次処理方法を提供することを目的とするものである。   The present invention provides a primary treatment method for combined sewage that solves the above-described conventional problems, can further reduce the pollution load of discharged water in rainy weather, and can reliably backwash the filter medium packed bed even in fine weather. It is intended to do.

上記の課題を解決するためになされた本発明の合流式下水の一次処理方法は、沈砂池を通過させた合流式下水の流入水を、浮上ろ材が充填された高速ろ過槽に晴天時にも雨天時にも導き、流入水量に応じて晴天時は低速で、雨天時はそれよりも高速でろ過し、そのろ過水を晴天時にも雨天時にも後段の反応槽へ送水する合流式下水の一次処理方法であって、ろ材充填層のろ過抵抗が晴天時には0.7〜2kPa、雨天時には3〜10kPaの設定圧に達するか、設定ろ過時間を経過したときに槽下部の高速排水弁を開いて槽上部のろ過水を自然流下させて下向流で浮上ろ材を洗浄するとともに、高速排水弁を開いてから10〜30秒後にろ材充填層の下部より空気を導入するパルス空気洗浄を、雨天時には1回、晴天時には2回以上繰り返すことを特徴とするものである。 The primary treatment method of the combined sewage of the present invention made to solve the above-mentioned problem is that the inflowing water of the combined sewage that has passed through the sand basin is rained in a high-speed filtration tank filled with floating filter media even in fine weather. The primary treatment method of combined sewage that guides sometimes, filters it at low speed in fine weather according to the amount of inflow water, and filters it at high speed in rainy weather, and sends the filtered water to the subsequent reaction tank in fine weather and rainy weather. And when the filtration resistance of the filter medium packed bed reaches a set pressure of 0.7-2 kPa when it is fine, and 3-10 kPa when it rains, or when the set filtration time has elapsed, the high-speed drain valve at the bottom of the tank is opened and the tank upper part is opened. The filtered water is allowed to flow down naturally and the floating filter medium is washed downward, and pulse air washing is performed once in rainy weather, 10-30 seconds after opening the high-speed drain valve, and air is introduced from the bottom of the filter medium packed bed. Repeat twice or more in fine weather And it is characterized in and.

なお、高速ろ過槽として、見掛け比重が0.1〜0.4、50%圧縮硬さが0.1MPa以上、サイズが4〜10mmで凹凸のある浮上ろ材を、層厚800mm以下で充填した上向流ろ過槽を使用することが好ましく、高速ろ過槽のろ過速度を、晴天時には500m/日未満、雨天時には500〜1200m/日とすることが好ましい。   In addition, as a high-speed filtration tank, an apparent specific gravity of 0.1 to 0.4, a 50% compression hardness of 0.1 MPa or more, a size of 4 to 10 mm and uneven floating filter material with a layer thickness of 800 mm or less It is preferable to use a countercurrent filtration tank, and the filtration speed of the high-speed filtration tank is preferably less than 500 m / day during fine weather and 500 to 1200 m / day during rainy weather.

さらに、高速ろ過槽と並列に傾斜板沈殿池を設置し、高速ろ過槽の処理能力を超過する流入水を簡易処理することが好ましい。 Furthermore, it is preferable to install an inclined plate sedimentation basin in parallel with the high-speed filtration tank and to simply process the inflowing water that exceeds the processing capacity of the high-speed filtration tank.

本発明の合流式下水の一次処理方法によれば、合流式下水の流入水を高速ろ過槽に晴天時にも雨天時にも導いて流入水量に応じて晴天時は低速で、雨天時はそれよりも高速でろ過し、そのろ過水を晴天時にも雨天時にも後段の反応槽及び最終沈殿池で処理したうえで放流するので、晴天時には通常の高級処理を行えることはもちろん、雨天時にも高速ろ過槽によるろ過処理と、反応槽及び最終沈殿池での処理とを行うことができる。雨天時における生物処理は水量Qを越えており、晴天時と同様の高級処理は行えないが、1Q分の高速ろ過ろ過水については従来通り反応槽の前段から投入し,1Q超過分の高速ろ過ろ過水については反応槽の後段に投入し活性汚泥の吸着作用でBODを吸着させることにより、高級処理効果をあげることができる。従って雨天時における放流水の汚濁負荷の低減に大きく寄与することができる。   According to the primary treatment method of the combined sewage of the present invention, the inflowing water of the combined sewage is guided to the high-speed filtration tank at the time of fine weather and rainy weather, and the speed is low at the time of fine weather according to the amount of the influent water, and it is more than that at the time of rainy weather. Since it is filtered at high speed and the filtered water is discharged in the latter reaction tank and final sedimentation basin during fine weather and rainy weather, it can be discharged in high-grade filtration tanks even in rainy weather. And the treatment in the reaction tank and the final sedimentation basin can be performed. Biological treatment in rainy weather exceeds the amount of water Q, and high-grade treatment similar to that in fine weather cannot be performed. However, high-speed filtered filtrate for 1Q is introduced from the previous stage of the reaction tank as usual, and high-speed filtration for excess of 1Q is used. About filtered water, a high-class process effect can be raised by throwing it into the back | latter stage of a reaction tank, and making BOD adsorb | suck by the adsorption | suction action of activated sludge. Therefore, it can greatly contribute to the reduction of the pollution load of the discharged water during rainy weather.

また本発明の合流式下水の一次処理方法によれば、晴天時には雨天時よりもろ過抵抗の設定圧を低くしておき、より早い段階で逆洗を行う。しかもパルス空気洗浄を、雨天時には1回であるが、晴天時には2回以上繰り返す。これによって流入水中の微細粒子の比率が高い晴天時における逆洗を、雨天時と同様に確実に行うことができる。   Moreover, according to the primary treatment method of the combined sewage of the present invention, the set pressure of the filtration resistance is set lower in the fine weather than in the rainy weather, and the backwash is performed at an earlier stage. Moreover, the pulsed air cleaning is performed once in rainy weather but is repeated twice or more in fine weather. As a result, backwashing in fine weather when the ratio of fine particles in the inflowing water is high can be reliably performed as in rainy weather.

以下に本発明の好ましい実施形態を説明する。
図1は本発明の実施形態のフロー図であり、沈砂池1、活性汚泥処理のための反応槽3、最終沈殿池4は従来と同様である。しかし従来の最初沈殿池2の設置スペースに、高速ろ過槽10と傾斜板沈殿池20とが並列に設置されている。合流式下水処理場の設計水量(晴天時日最大流入水量)をQとしたとき、この実施形態では流入水量が3Qまでは沈砂池1を通った流入水の全量を高速ろ過槽10に導き、3Q超過分は傾斜板沈殿池20に導くようになっている。
Hereinafter, preferred embodiments of the present invention will be described.
FIG. 1 is a flow diagram of an embodiment of the present invention, where a sand basin 1, a reaction tank 3 for activated sludge treatment, and a final sedimentation basin 4 are the same as in the prior art. However, the high-speed filtration tank 10 and the inclined plate sedimentation tank 20 are installed in parallel in the installation space of the conventional first sedimentation tank 2. In this embodiment, when the design water amount of the combined sewage treatment plant (the maximum amount of inflow water on a clear day) is Q, the total amount of inflow water that has passed through the settling basin 1 is led to the high-speed filtration tank 10 until the inflow water amount is 3Q. The amount exceeding 3Q is led to the inclined plate sedimentation basin 20.

高速ろ過槽10は、図2に示すように分配槽11と複数のろ過水槽12を備えたものであり、各ろ過水槽12の内部に浮上ろ材13が充填されたろ材充填層14を形成してある。ろ材充填層14の層厚は800mm以下、より好ましくは600mm程度とし、晴天時にも逆洗が容易に行なえるようにしておく。なお、ろ材充填層14の上面にはスクリーン15が設置されて浮上ろ材13の流出を防止している。   As shown in FIG. 2, the high-speed filtration tank 10 includes a distribution tank 11 and a plurality of filtered water tanks 12, and a filter medium packed layer 14 filled with a floating filter medium 13 is formed inside each filtered water tank 12. is there. The layer thickness of the filter medium packed layer 14 is set to 800 mm or less, more preferably about 600 mm so that backwashing can be easily performed even in fine weather. A screen 15 is installed on the upper surface of the filter medium packed bed 14 to prevent the floating filter medium 13 from flowing out.

浮上ろ材13としては、見掛け比重が0.1〜0.4、50%圧縮硬さが0.1MPa以上、サイズが4〜10mmの材質のものが用いられる。見掛け比重が0.1未満であると望ましい圧縮強さを得ることができず、0.4を越えると水との比重差が小さくなって流出のおそれがある。50%圧縮硬さを0.1MPa以上としたのは、これよりも軟質であると高速ろ過の際に圧密されてSS捕捉能力が低下するためである。さらにサイズが4mm未満であると相互間の間隙が小さくなって閉塞し易く、10mmとなってもSS捕捉能力が低下するためである。   As the floating filter 13, a material having an apparent specific gravity of 0.1 to 0.4, a 50% compression hardness of 0.1 MPa or more, and a size of 4 to 10 mm is used. If the apparent specific gravity is less than 0.1, the desired compressive strength cannot be obtained, and if it exceeds 0.4, the specific gravity difference with water becomes small and there is a risk of outflow. The reason why the 50% compression hardness is set to 0.1 MPa or more is that if it is softer than this, it will be consolidated during high-speed filtration and the SS trapping ability will be reduced. Furthermore, if the size is less than 4 mm, the gap between them becomes small and the blockage tends to be blocked, and even if the size is 10 mm, the SS capturing ability is lowered.

このような特性の浮上ろ材13は、発泡ポリエチレン、発泡ポリスチレン、発泡ポリプロピレンなどにより製造することができる。浮上ろ材13の形状は、図3に示されるような凹凸のある形状とすることにより、充填時に浮上ろ材13の相互間に非直線的な間隙が形成され、SS捕捉効果を高めることができる。   The floating filter 13 having such characteristics can be manufactured from foamed polyethylene, foamed polystyrene, foamed polypropylene, or the like. By making the shape of the floating filter material 13 to have an uneven shape as shown in FIG. 3, a non-linear gap is formed between the floating filter materials 13 at the time of filling, and the SS capturing effect can be enhanced.

本発明では、流入水の全量を先ず沈砂池1に導いて砂分等を除去したうえ、晴天時にも雨天時にも、3Qまでの水量までは高速ろ過槽10に導く。流入水は図2に示す分配槽11にて各池毎に設置される各池流入水管21に分配された後、各々の各池流入配管21から各ろ過水槽12の下部に導入され、浮上ろ材13が充填されたろ材充填層14を上向流で通過する間に、SSが浮上ろ材13に捕捉されてろ過される。ろ過水はスクリーン15の上方に形成された共通ろ過水層16に入る。なお、ろ材充填層14の逆洗は各ろ過水槽12の下部の高速排水弁17を開き、槽上部の共通ろ過水層16内のろ過水を自然流下させる方法で行われるが、その詳細は後述する。   In the present invention, the entire amount of inflowing water is first guided to the settling basin 1 to remove sand and the like, and is guided to the high-speed filtration tank 10 up to the amount of water up to 3Q in fine weather and rainy weather. The inflow water is distributed to each pond inflow water pipe 21 installed for each pond in the distribution tank 11 shown in FIG. 2, and then introduced into the lower portion of each filtered water tank 12 from each pond inflow pipe 21. While passing through the filter medium packed bed 14 filled with 13 in an upward flow, SS is captured by the floating filter medium 13 and filtered. The filtered water enters a common filtered water layer 16 formed above the screen 15. The backwashing of the filter medium packed bed 14 is performed by a method in which the high-speed drain valve 17 at the bottom of each filtered water tank 12 is opened and the filtered water in the common filtered water layer 16 at the top of the tank is allowed to flow down naturally. To do.

合流式下水処理場では、晴天時の流入水量はQ以下であり、雨天時には流入水量はQを越え3Qに達する。このため、高速ろ過槽10は流入水量に応じて晴天時は低速で、雨天時はそれよりも高速でろ過を行う。本発明で用いられる高速ろ過槽10は1000m/日を越える高速ろ過が可能であり、ろ過速度を晴天時には500m/日未満、雨天時には500〜1200m/日とすることが好ましい。   In a combined sewage treatment plant, the amount of inflow water during clear weather is Q or less, and the amount of inflow water exceeds Q and reaches 3Q during rainy weather. For this reason, the high-speed filtration tank 10 performs filtration at a low speed during fine weather and at a higher speed during rainy weather depending on the amount of inflow water. The high-speed filtration tank 10 used in the present invention is capable of high-speed filtration exceeding 1000 m / day, and the filtration speed is preferably less than 500 m / day during fine weather and 500 to 1200 m / day during rainy weather.

高速ろ過槽10のろ過水は共通ろ過水層16を経由し、その全量が反応槽3、最終沈殿池4に送水される。晴天時には流入水量がQ以下であるから、反応槽3、最終沈殿池4において通常の高級処理が行われる。また雨天時には反応槽3の本来の処理能力を越える水量が導入されることとなるが、Qを越えた分は反応槽3の後部付近から導入することによって、良好な生物処理が行われる。最終沈殿池4から出た処理水は殺菌したうえで放流される。   The filtered water in the high-speed filtration tank 10 passes through the common filtered water layer 16, and the entire amount is sent to the reaction tank 3 and the final sedimentation tank 4. Since the amount of inflow water is Q or less during fine weather, ordinary high-level treatment is performed in the reaction tank 3 and the final sedimentation tank 4. In addition, when it rains, an amount of water exceeding the original treatment capacity of the reaction tank 3 is introduced. However, when the amount exceeding Q is introduced from the vicinity of the rear part of the reaction tank 3, favorable biological treatment is performed. The treated water discharged from the final sedimentation basin 4 is sterilized and then discharged.

このように本発明では3Qまでの流量については、晴天時にも雨天時にも高速ろ過槽10でろ過が行われるが、前記したように晴天時には雨天時よりも流入水中の微細粒子の比率が高く、ろ材充填層14の奥まで侵入して逆洗効果が低下する。従って本発明では晴天時モードと雨天時モードとを区別し、逆洗条件を別に設定しておく。   Thus, in the present invention, the flow rate up to 3Q is filtered in the high-speed filtration tank 10 in fine weather and rainy weather, but as described above, the ratio of fine particles in the inflowing water is higher than in rainy weather as described above. The backwashing effect is lowered by intruding to the depth of the filter medium packed bed 14. Therefore, in the present invention, the clear weather mode and the rainy weather mode are distinguished, and the backwash conditions are set separately.

すなわち、雨天時モードではろ過抵抗の設定圧を3〜10kPa(水位差30〜100cm)とするが、晴天時モードでは0.7〜2kPaとより低い値に設定し、ろ材充填層14のろ過抵抗が低い段階で逆洗を行う。これは晴天時においてはろ過抵抗が3〜10kPaに達した後に逆洗を行っても、微細なSSによる固化が進行しているため、雨天時に比べて均一な逆洗を行いにくいためである。   That is, although the set pressure of the filtration resistance is 3 to 10 kPa (water level difference 30 to 100 cm) in the rainy day mode, the filtration resistance of the filter medium packed bed 14 is set to a lower value of 0.7 to 2 kPa in the fine weather mode. Perform backwashing at a low stage. This is because, even when backwashing is performed after the filtration resistance reaches 3 to 10 kPa in fine weather, solidification by fine SS is progressing, so that uniform backwashing is difficult to perform compared with rainy weather.

また高速排水弁17を開いてから10〜30秒後にろ材充填層14の下部の空気管18より短時間空気を導入するパルス空気洗浄を行うが、これを雨天時には逆洗ごとに1回行うのに対して、晴天時には逆洗ごとに2回以上繰り返す。これにより微細粒子によって固まったろ材充填層14をバラバラにし、均一な逆洗が可能となる。逆洗によりろ材充填層14に捕捉されていたSSは下方に放出され、逆洗排水として最初沈殿池を区切って形成された逆洗排水槽19に取り出される。前記したように浮上ろ材13は比重が小さいので、ろ材充填層14の下部に流出防止用のスクリーンを設置しなくても、逆洗時に下方に流出することがない。   In addition, 10 to 30 seconds after opening the high-speed drain valve 17, pulsed air cleaning is performed in which air is introduced for a short time from the air pipe 18 below the filter medium packed bed 14. On the other hand, it repeats twice or more for each backwash in fine weather. As a result, the filter medium packed layer 14 solidified by the fine particles is separated, and uniform backwashing is possible. The SS trapped in the filter medium packed bed 14 by backwashing is discharged downward and taken out as backwashing drainage into a backwashing drainage tank 19 formed by first partitioning the settling basin. As described above, since the floating filter 13 has a small specific gravity, it does not flow downward during backwashing even if a screen for preventing outflow is not installed below the filter medium packed bed 14.

なお、時に晴天時モードにおいて流入水量の少ないときには、ろ過抵抗の設定圧を0.7〜2kPaと低く設定してもなかなかその値に到達しない場合がある。このような状態を放置すると微細粒子によるろ材充填層13の固化が進行するため、ろ材充填層13のろ過抵抗が設定圧に達しなくても、設定ろ過時間を経過したときには逆洗を開始することが好ましい。   In some cases, when the amount of inflow water is small in the fine weather mode, even if the set pressure of the filtration resistance is set as low as 0.7 to 2 kPa, the value may not be reached easily. If such a state is left as it is, solidification of the filter medium packed bed 13 with fine particles proceeds, so that even if the filtration resistance of the filter medium packed bed 13 does not reach the set pressure, the backwashing is started when the set filtration time has elapsed. Is preferred.

このようにして、本発明によれば晴天時には通常の一次処理と同等性能以上のろ過処理を経て高級処理を行えることはもちろん、雨天時にも高速ろ過槽10によるろ過処理と、反応槽3及び最終沈殿池4での高級処理とを行うことができ、雨天時における放流水の汚濁負荷の低減に大きく寄与することができる。また晴天時モードでは雨天時モードよりもろ過抵抗の設定圧を低くしておき、より早い段階で逆洗を行い、しかもパルス空気洗浄を晴天時には2回以上繰り返すことによって、流入水中の微細粒子の比率が高い晴天時における逆洗を、雨天時と同様に確実に行うことができる。   In this way, according to the present invention, high-quality processing can be performed through filtration processing equivalent to or higher than that of the normal primary processing in fine weather, as well as filtration processing in the high-speed filtration tank 10 in the rainy weather, the reaction tank 3 and the final processing. High-grade treatment in the sedimentation basin 4 can be performed, and it can greatly contribute to the reduction of the pollutant load of discharged water in rainy weather. Also, in fine weather mode, the set pressure of filtration resistance is lower than in rainy weather mode, backwashing is performed at an earlier stage, and pulse air washing is repeated twice or more in fine weather so that fine particles in the influent water can be removed. Backwashing during high-ratio sunny weather can be performed reliably as in rainy weather.

なお、この実施形態では3Qを越え6Qまでの流入水については、傾斜板沈殿池20による簡易処理を行う。傾斜板沈殿池20は例えば図4に示すように槽内に多数の傾斜板21を配置したもので、流入水中のSSは傾斜板21の間隙を上向流で通過する際に傾斜板21に捕捉され、分離される。必要に応じてこの傾斜板沈殿池20の前段で凝集剤を添加すれば、より優れたSS除去効果を得ることができる。流入水量が6Qを越える場合にはその分はやむを得ず直接放流することとなる。   In this embodiment, the inflowing water exceeding 3Q and up to 6Q is simply processed by the inclined plate sedimentation basin 20. For example, as shown in FIG. 4, the inclined plate sedimentation basin 20 has a large number of inclined plates 21 arranged in the tank, and the SS in the inflowing water flows into the inclined plate 21 when passing through the gap between the inclined plates 21 in an upward flow. Captured and separated. If a flocculant is added before the inclined plate sedimentation basin 20 as required, a more excellent SS removal effect can be obtained. If the amount of inflow water exceeds 6Q, it will be unavoidable that it will be discharged directly.

大阪市内の合流式下水処理場に、ろ過面積が4mの高速ろ過槽を設置し、8ヶ月間にわたり実験を行った。浮上ろ材13は一辺が7.5mmで厚さが4mmの風車型であり、見掛け比重は0.1〜0.4、50%圧縮硬さが0.1MPa以上である。充填層厚は600mmとした。雨天時モードでは自動逆洗を開始するろ過抵抗の設定圧を4kPa、パルス空気洗浄時間を60秒間×1回とし、晴天時モードでは自動逆洗を開始するろ過抵抗の設定圧を1kPa、パルス空気洗浄時間を40秒間×2回とした。また晴天時モードではタイマーを用い、前回の逆洗から8時間を経過すると、ろ過抵抗の設定圧が1kPaに達しなくても逆洗を行うようにした。 A high-speed filtration tank with a filtration area of 4 m 2 was installed in a combined sewage treatment plant in Osaka city, and experiments were conducted for 8 months. The floating filter 13 is a windmill type having a side of 7.5 mm and a thickness of 4 mm, an apparent specific gravity of 0.1 to 0.4, and a 50% compression hardness of 0.1 MPa or more. The packed layer thickness was 600 mm. In rainy weather mode, the set pressure of filtration resistance to start automatic backwash is 4 kPa, pulse air washing time is 60 seconds x 1 time. In fine weather mode, the setting pressure of filtration resistance to start automatic backwash is 1 kPa, pulsed air The washing time was 40 seconds x 2 times. In the fine weather mode, a timer was used, and after 8 hours from the previous backwash, backwashing was performed even if the set pressure of the filtration resistance did not reach 1 kPa.

高速ろ過槽のろ過速度の最大値を、晴天時には500m/日、雨天時には1200m/日と設定し、合流式下水の処理を行った。実験中、雨天時において流入水のSS濃度が1400mg/Lに達したときにもろ過水のSS濃度は200mg/L以下に維持され、雨天時において流入水のBOD濃度が500mg/Lに達したときにもろ過水のBOD濃度は150mg/L以下に維持されていた。また晴天時においても自動逆洗は良好に行われた。   The maximum value of the filtration rate of the high-speed filtration tank was set to 500 m / day when it was fine, and 1200 m / day when it was raining, and combined sewage was treated. During the experiment, even when the SS concentration of influent water reached 1400 mg / L during rainy weather, the SS concentration of filtered water was maintained at 200 mg / L or less, and the BOD concentration of influent water reached 500 mg / L during rainy weather. Occasionally, the BOD concentration of filtered water was maintained at 150 mg / L or less. Moreover, automatic backwashing was performed well even in fine weather.

本発明の実施形態を示すフロー図である。It is a flowchart which shows embodiment of this invention. 高速ろ過槽の断面図である。It is sectional drawing of a high-speed filtration tank. 浮上ろ材を示す平面図である。It is a top view which shows a floating filter medium. 傾斜板沈殿池を示す断面図である。It is sectional drawing which shows an inclined plate sedimentation basin. 従来法を示すフロー図である。It is a flowchart which shows a conventional method.

符号の説明Explanation of symbols

1 沈砂池
2 最初沈殿池
3 反応槽
4 最終沈殿池
10 高速ろ過槽
11 分配槽
12 ろ過水槽
13 浮上ろ材
14 ろ材充填層
15 スクリーン
16 共通ろ過水槽
17 高速排水弁
18 空気管
19 逆洗排水槽
20 傾斜板沈殿池
21 各池流入水管
DESCRIPTION OF SYMBOLS 1 Sedimentation basin 2 First sedimentation basin 3 Reaction tank 4 Final sedimentation basin 10 High speed filtration tank 11 Distribution tank 12 Filtration water tank 13 Floating filter medium 14 Filter medium packing layer 15 Screen 16 Common filtration water tank 17 High speed drain valve 18 Air pipe 19 Backwash drain tank 20 Inclined plate settling basin 21

Claims (3)

沈砂池を通過させた合流式下水の流入水を、浮上ろ材が充填された高速ろ過槽に晴天時にも雨天時にも導き、流入水量に応じて晴天時は低速で、雨天時はそれよりも高速でろ過し、そのろ過水を晴天時にも雨天時にも後段の反応槽へ送水する合流式下水の一次処理方法であって、ろ材充填層のろ過抵抗が晴天時には0.7〜2kPa、雨天時には3〜10kPaの設定圧に達するか、設定ろ過時間を経過したときに槽下部の高速排水弁を開いて槽上部のろ過水を自然流下させて下向流で浮上ろ材を洗浄するとともに、高速排水弁を開いてから10〜30秒後にろ材充填層の下部より空気を導入するパルス空気洗浄を、雨天時には1回、晴天時には2回以上繰り返すことを特徴とする合流式下水の一次処理方法。 The inflow of combined sewage that has passed through the settling basin is guided to a high-speed filtration tank filled with floating filter medium during fine weather and rainy weather. In the primary treatment method of combined sewage in which the filtered water is sent to the subsequent reaction tank in fine weather and rainy weather, the filtration resistance of the filter medium packed bed is 0.7 to 2 kPa in fine weather and 3 in rainy weather. When the set pressure of -10 kPa is reached or the set filtration time has elapsed, the high-speed drain valve at the bottom of the tank is opened to allow the filtered water at the top of the tank to flow down naturally to wash the floating filter material downward, and the high-speed drain valve A method for primary treatment of combined sewage, characterized in that pulsed air cleaning, in which air is introduced from the lower part of the filter medium packed bed 10 to 30 seconds after opening, is repeated once in rainy weather and twice or more in fine weather . 高速ろ過槽として、見掛け比重が0.1〜0.4、50%圧縮硬さが0.1MPa以上、サイズが4〜10mmで凹凸のある浮上ろ材を、層厚800mm以下で充填した上向流ろ過槽を使用することを特徴とする請求項1記載の合流式下水の一次処理方法。   As a high-speed filtration tank, an upward flow in which an apparent specific gravity is 0.1 to 0.4, a 50% compression hardness is 0.1 MPa or more, a size is 4 to 10 mm, and an uneven floating filter medium is filled with a layer thickness of 800 mm or less. The primary treatment method for combined sewage according to claim 1, wherein a filtration tank is used. 高速ろ過槽のろ過速度を、晴天時には500m/日未満、雨天時には500〜1200m/日とすることを特徴とする請求項1記載の合流式下水の一次処理方法。   The primary treatment method for combined sewage according to claim 1, wherein the filtration rate of the high-speed filtration tank is less than 500 m / day during fine weather, and 500 to 1200 m / day during rainy weather.
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Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0576704A (en) * 1991-09-25 1993-03-30 Ngk Insulators Ltd Mehtod for filtering sewage
JPH07290085A (en) * 1994-04-21 1995-11-07 Hitachi Plant Eng & Constr Co Ltd Treatment of waste water and device therefor
JPH0810523A (en) * 1994-04-26 1996-01-16 Toyo Eng Corp Method for washing floating filter medium
JPH0857465A (en) * 1994-08-15 1996-03-05 Daiwa Kogyo Kk Backwashing of water treatment apparatus using floating filter material
JPH0889982A (en) * 1994-09-27 1996-04-09 Best Kogyo Kk Method for cleaning floating filter medium for biological filter
JPH08173975A (en) * 1994-12-22 1996-07-09 Hitachi Plant Eng & Constr Co Ltd Method and apparatus for solid-liquid separation of wastewater
JP2001219193A (en) * 2000-02-09 2001-08-14 Ngk Insulators Ltd Method and apparatus for treating sewage in confluent type sewerage
WO2002072227A1 (en) * 2001-03-13 2002-09-19 Ngk Insulators, Ltd. High rate filter and high rate filtration method using the filter
WO2002081050A1 (en) * 2001-04-04 2002-10-17 Ngk Insulators, Ltd. Rain water treating device in combined sewage, and backwashing method therefor
JP2003136088A (en) * 2001-11-06 2003-05-13 Ngk Insulators Ltd Sewage treatment method and apparatus in confluent type sewerage
JP2003144814A (en) * 2001-11-13 2003-05-20 Ngk Insulators Ltd Method for washing floating filter medium
JP2003154211A (en) * 2001-11-21 2003-05-27 Ngk Insulators Ltd Method of treating uncertain water in separated sewer system
JP2004050134A (en) * 2002-07-23 2004-02-19 Ebara Corp Apparatus for treating combined sewage
JP2004113940A (en) * 2002-09-26 2004-04-15 Tatsuya Sakamoto Moving bed type filtration equipment and its operation method
JP2004209439A (en) * 2003-01-08 2004-07-29 Unitika Ltd Filtration method for sewage
JP2004290822A (en) * 2003-03-27 2004-10-21 Ngk Insulators Ltd Method for washing/dispersing floating filter medium
JP2005034763A (en) * 2003-07-16 2005-02-10 Ngk Insulators Ltd Reconstruction method of existing sewage treatment plant
JP2005279386A (en) * 2004-03-29 2005-10-13 Kurita Water Ind Ltd Waste water treatment apparatus
JP2007000737A (en) * 2005-06-22 2007-01-11 Hitachi Plant Technologies Ltd Solid-liquid separator of combined sewer system and sewage treatment method effectively using existing treatment facility
JP2007038092A (en) * 2005-08-02 2007-02-15 Ngk Insulators Ltd Apparatus and method for treatment of sewage in rainy weather and secondary effluent

Patent Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0576704A (en) * 1991-09-25 1993-03-30 Ngk Insulators Ltd Mehtod for filtering sewage
JPH07290085A (en) * 1994-04-21 1995-11-07 Hitachi Plant Eng & Constr Co Ltd Treatment of waste water and device therefor
JPH0810523A (en) * 1994-04-26 1996-01-16 Toyo Eng Corp Method for washing floating filter medium
JPH0857465A (en) * 1994-08-15 1996-03-05 Daiwa Kogyo Kk Backwashing of water treatment apparatus using floating filter material
JPH0889982A (en) * 1994-09-27 1996-04-09 Best Kogyo Kk Method for cleaning floating filter medium for biological filter
JPH08173975A (en) * 1994-12-22 1996-07-09 Hitachi Plant Eng & Constr Co Ltd Method and apparatus for solid-liquid separation of wastewater
JP2001219193A (en) * 2000-02-09 2001-08-14 Ngk Insulators Ltd Method and apparatus for treating sewage in confluent type sewerage
WO2002072227A1 (en) * 2001-03-13 2002-09-19 Ngk Insulators, Ltd. High rate filter and high rate filtration method using the filter
WO2002081050A1 (en) * 2001-04-04 2002-10-17 Ngk Insulators, Ltd. Rain water treating device in combined sewage, and backwashing method therefor
JP2003136088A (en) * 2001-11-06 2003-05-13 Ngk Insulators Ltd Sewage treatment method and apparatus in confluent type sewerage
JP2003144814A (en) * 2001-11-13 2003-05-20 Ngk Insulators Ltd Method for washing floating filter medium
JP2003154211A (en) * 2001-11-21 2003-05-27 Ngk Insulators Ltd Method of treating uncertain water in separated sewer system
JP2004050134A (en) * 2002-07-23 2004-02-19 Ebara Corp Apparatus for treating combined sewage
JP2004113940A (en) * 2002-09-26 2004-04-15 Tatsuya Sakamoto Moving bed type filtration equipment and its operation method
JP2004209439A (en) * 2003-01-08 2004-07-29 Unitika Ltd Filtration method for sewage
JP2004290822A (en) * 2003-03-27 2004-10-21 Ngk Insulators Ltd Method for washing/dispersing floating filter medium
JP2005034763A (en) * 2003-07-16 2005-02-10 Ngk Insulators Ltd Reconstruction method of existing sewage treatment plant
JP2005279386A (en) * 2004-03-29 2005-10-13 Kurita Water Ind Ltd Waste water treatment apparatus
JP2007000737A (en) * 2005-06-22 2007-01-11 Hitachi Plant Technologies Ltd Solid-liquid separator of combined sewer system and sewage treatment method effectively using existing treatment facility
JP2007038092A (en) * 2005-08-02 2007-02-15 Ngk Insulators Ltd Apparatus and method for treatment of sewage in rainy weather and secondary effluent

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