JP6640837B2 - Water treatment device and water treatment method - Google Patents

Water treatment device and water treatment method Download PDF

Info

Publication number
JP6640837B2
JP6640837B2 JP2017509866A JP2017509866A JP6640837B2 JP 6640837 B2 JP6640837 B2 JP 6640837B2 JP 2017509866 A JP2017509866 A JP 2017509866A JP 2017509866 A JP2017509866 A JP 2017509866A JP 6640837 B2 JP6640837 B2 JP 6640837B2
Authority
JP
Japan
Prior art keywords
water
reaction tank
treated
anaerobic reaction
anaerobic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
JP2017509866A
Other languages
Japanese (ja)
Other versions
JPWO2016158673A1 (en
Inventor
若原　慎一郎
慎一郎 若原
舞穂 小林
舞穂 小林
慎太郎 ▲高▼橋
慎太郎 ▲高▼橋
岡田　公一
公一 岡田
弘二 服部
弘二 服部
正修 岩橋
正修 岩橋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kubota Corp
Original Assignee
Kubota Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kubota Corp filed Critical Kubota Corp
Publication of JPWO2016158673A1 publication Critical patent/JPWO2016158673A1/en
Application granted granted Critical
Publication of JP6640837B2 publication Critical patent/JP6640837B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/28—Anaerobic digestion processes

Description

本発明は、上向流式の嫌気性反応槽を有する水処理装置と、当該嫌気性反応槽を用いた水処理方法に関する。   The present invention relates to a water treatment apparatus having an upward anaerobic reaction tank and a water treatment method using the anaerobic reaction tank.

従来、被処理水を上向流式で嫌気性微生物を含む汚泥（嫌気性汚泥）と接触させて嫌気性処理を行う水処理装置や水処理方法が知られている。例えば、特許文献１，２には、ＵＡＳＢ（Ｕｐｆｌｏｗ Ａｎａｅｒｏｂｉｃ Ｓｌｕｄｇｅ Ｂｌａｎｋｅｔ：上向流嫌気性汚泥床）法により嫌気性処理を行う嫌気性反応槽を含む水処理装置が開示されており、ＵＡＳＢ法では、嫌気性汚泥が、比較的沈降性の高い粒状に形成されたグラニュール汚泥として嫌気性反応槽内に保持されている。   BACKGROUND ART Conventionally, a water treatment apparatus and a water treatment method for performing anaerobic treatment by contacting treated water with sludge containing anaerobic microorganisms (anaerobic sludge) in an upward flow manner are known. For example, Patent Literatures 1 and 2 disclose a water treatment apparatus including an anaerobic reaction tank that performs anaerobic treatment by the UASB (Upflow Anaerobic Sludge Blanket) method. The anaerobic sludge is held in the anaerobic reaction tank as granular sludge formed in granular form having relatively high sedimentation.

特開平６−２５４５８８号公報JP-A-6-254588 特開２００２−２６３６８３号公報JP-A-2002-263683

嫌気性反応槽では、被処理水を嫌気性処理することによりメタンガス等が発生するため、処理に伴って汚泥の一部がガスとともに水面まで浮上する。特に上向流式の嫌気性反応槽では、反応槽内の上向きの水の流れによっても汚泥の浮上が促進される。浮上した汚泥は、そのまま放置すると嫌気性反応槽から流出し、嫌気性反応槽内での嫌気性汚泥濃度の低下を招く。これに対して、特許文献１，２に開示された水処理装置では、浮上した汚泥の沈降を促すために、嫌気性反応槽内の水面より上方にスプレー手段を設けている。しかし本発明者らが検討したところ、水面の上方からスプレーする方法では、浮上した汚泥の流出抑制効果は十分とはいえず、嫌気性反応槽内に保持された被処理水の汚泥濃度を高く維持することは難しいことが明らかになった。   In the anaerobic reaction tank, methane gas or the like is generated by anaerobic treatment of the water to be treated, so that part of the sludge rises to the water surface together with the gas during the treatment. In particular, in the upward flow type anaerobic reaction tank, the floating of sludge is promoted by the upward flow of water in the reaction tank. The floating sludge, if left as it is, flows out of the anaerobic reaction tank, causing a decrease in the anaerobic sludge concentration in the anaerobic reaction tank. On the other hand, in the water treatment apparatuses disclosed in Patent Literatures 1 and 2, spray means is provided above the water surface in the anaerobic reaction tank in order to promote the settling of the sludge that has floated. However, the present inventors have examined that the method of spraying from above the water surface does not have a sufficient effect of suppressing the emergence of the sludge that has floated, and increases the sludge concentration of the water to be treated held in the anaerobic reaction tank. It proved difficult to maintain.

本発明は前記事情に鑑みてなされたものであり、その目的は、上向流式の嫌気性反応槽を用いて嫌気性処理を行うにあたり、嫌気性反応槽からの汚泥の流出を抑え、嫌気性反応槽内に保持された被処理水の汚泥濃度を高く維持することができる水処理装置および水処理方法を提供することにある。   The present invention has been made in view of the above circumstances, and an object of the present invention is to perform an anaerobic treatment using an upward anaerobic reaction tank, thereby suppressing the outflow of sludge from the anaerobic reaction tank, It is an object of the present invention to provide a water treatment apparatus and a water treatment method capable of maintaining a high concentration of sludge of water to be treated held in a sexual reaction tank.

上記課題を解決することができた本発明の水処理装置とは、被処理水の流入部と、流入部より上方に位置する処理水の流出部とを有し、流出部の高さまで嫌気性汚泥を含む被処理水が保持された、上向流式の嫌気性反応槽と、嫌気性反応槽に設けられた液体の供給管とを有する水処理装置であって、前記供給管は、嫌気性反応槽内の被処理水の上部１／３の領域または水面より上方に位置する開口を有し、前記開口が略水平方向に向いているところに特徴を有する。本発明の水処理装置によれば、略水平方向に向いた開口を有する供給管から液体を供給することにより、嫌気性反応槽に保持された被処理水の水面近くを撹乱して、略水平方向の水の流れを形成することができ、ガスを抱き込んだ形で水面に浮上した汚泥からガスを効果的に分離できる。そのため、嫌気性反応槽内の被処理水の水面に浮上した汚泥を沈降させやすくなり、被処理水の汚泥濃度を高く維持することができる。   The water treatment apparatus of the present invention that can solve the above problem has an inflow portion of water to be treated and an outflow portion of treated water located above the inflow portion, and is anaerobic to the height of the outflow portion. A water treatment apparatus having an upflow anaerobic reaction tank in which water to be treated containing sludge is held, and a liquid supply pipe provided in the anaerobic reaction tank, wherein the supply pipe is anaerobic. It has an opening located above the upper third of the water to be treated or in the water above the surface of the water in the reaction vessel, and the opening is oriented substantially in the horizontal direction. According to the water treatment apparatus of the present invention, the liquid is supplied from a supply pipe having an opening oriented in a substantially horizontal direction, thereby disturbing the surface of the water to be treated held in the anaerobic reaction tank and disturbing the liquid in a substantially horizontal direction. The flow of water in the direction can be formed, and the gas can be effectively separated from the sludge floating on the surface of the water while holding the gas. Therefore, the sludge floating on the water surface of the water to be treated in the anaerobic reaction tank is easily settled, and the sludge concentration of the water to be treated can be kept high.

本発明の水処理装置は、被処理水の流入部と、流入部より上方に位置する処理水の流出部とを有し、流出部の高さまで嫌気性汚泥を含む被処理水が保持された、上向流式の嫌気性反応槽と、嫌気性反応槽内の被処理水の上部１／３の領域に設けられた撹拌板とを有するものであってもよい。この場合、嫌気性反応槽内の被処理水の上部１／３の領域に設けた撹拌板を動かすことにより、水面に浮上した汚泥を揺動して汚泥からガスを分離し、汚泥を沈降させることができ、被処理水の汚泥濃度を高く維持することができる。   The water treatment apparatus of the present invention has an inflow portion of the to-be-treated water and an outflow portion of the treated water located above the inflow portion, and the to-be-treated water containing the anaerobic sludge is held up to the height of the outflow portion. And an upflow anaerobic reaction tank, and a stirring plate provided in an upper third region of the water to be treated in the anaerobic reaction tank. In this case, by moving the agitating plate provided in the upper third area of the water to be treated in the anaerobic reaction tank, the sludge floating on the water surface is swung to separate gas from the sludge and settle the sludge. The sludge concentration of the water to be treated can be kept high.

供給管の開口は、嫌気性反応槽内の水面を含む位置に設けられていることが好ましい。供給管の開口が嫌気性反応槽内の水面を含む位置に設けられれば、液体を開口から吐出することにより、被処理水の水面近くを広範囲にわたって撹乱しやすくなる。   The opening of the supply pipe is preferably provided at a position including the water surface in the anaerobic reaction tank. If the opening of the supply pipe is provided at a position including the water surface in the anaerobic reaction tank, the vicinity of the water surface of the water to be treated is easily disturbed over a wide range by discharging the liquid from the opening.

供給管から供給される液体の供給時間は、１時間当たり２秒以上２０分以下であることが好ましい。液体の供給時間をこのように調整することで、液体を供給することにより汚泥の沈降を効果的に促すことができるとともに、液体の供給により汚泥が過度に細分化するのを防ぐことができ、これにより嫌気性反応槽からの汚泥の流出を好適に抑制することができる。   The supply time of the liquid supplied from the supply pipe is preferably from 2 seconds to 20 minutes per hour. By adjusting the supply time of the liquid in this way, the settling of the sludge can be effectively promoted by supplying the liquid, and the sludge can be prevented from being excessively fragmented by the supply of the liquid. Thereby, outflow of sludge from the anaerobic reaction tank can be suitably suppressed.

供給管から供給される液体の１日当たりの供給量は、被処理水の１日当たりの流入量の１／２００以上１／１０以下であることが好ましい。このように液体の供給量を調整することで、汚泥の細分化を抑えつつ、汚泥の沈降を促して、嫌気性反応槽からの汚泥の流出を好適に抑えることができる。   The daily supply amount of the liquid supplied from the supply pipe is preferably 1/200 or more and 1/10 or less of the daily inflow amount of the water to be treated. By adjusting the supply amount of the liquid in this way, it is possible to promote the settling of the sludge while suppressing the fragmentation of the sludge, and to appropriately suppress the outflow of the sludge from the anaerobic reaction tank.

本発明の水処理装置は、嫌気性反応槽の流出部に連通し、嫌気性反応槽の処理水が濃縮される濃縮槽と、濃縮槽で得られた濃縮汚泥を供給管に移送する移送手段とをさらに有し、濃縮汚泥を前記液体として用いるものであることが好ましい。嫌気性反応槽から流出した処理水を濃縮して回収し、これを供給管から供給する液体として用いることにより、嫌気性反応槽内の被処理水の汚泥濃度を高く維持することができる。   The water treatment apparatus of the present invention is connected to an outlet of an anaerobic reaction tank, a concentration tank in which the treated water in the anaerobic reaction tank is concentrated, and a transfer means for transferring the concentrated sludge obtained in the concentration tank to a supply pipe. And it is preferable to use concentrated sludge as the liquid. By concentrating and collecting the treated water flowing out of the anaerobic reaction tank and using this as the liquid supplied from the supply pipe, the sludge concentration of the water to be treated in the anaerobic reaction tank can be kept high.

嫌気性反応槽には、水面を、流出部を含む部分と流出部を含まない部分とに分ける仕切り部材が設けられ、供給管の開口が流出部を含まない部分またはその上方もしくは下方に位置するように設けられ、あるいは、撹拌板が流出部を含まない部分の下方に設けられることが好ましい。嫌気性反応槽に仕切り部材を設けることにより、嫌気性反応槽内の水面の流出部を含まない部分に浮上した汚泥が流出部から流出しにくくなり、流出部を含まない部分に浮上した汚泥を効率的に沈降させることができる。   The anaerobic reaction tank is provided with a partition member that divides the water surface into a portion including the outflow portion and a portion not including the outflow portion, and the opening of the supply pipe is positioned above or below the portion not including the outflow portion. It is preferable that the stirring plate is provided below the portion not including the outflow portion. By providing a partition member in the anaerobic reaction tank, the sludge floating on the portion of the anaerobic reaction tank that does not include the outflow portion becomes difficult to flow out of the outflow portion, and the sludge that floats on the portion that does not include the outflow portion is removed. It can be settled efficiently.

嫌気性反応槽に仕切り部材が設けられる場合、嫌気性反応槽に保持された被処理水中に傾斜板が設けられることが好ましい。この場合、傾斜板は、上端が、仕切り部材に接続するか、流出部を含まない部分またはその上方もしくは下方に位置し、下端が流出部を含む部分の下方に位置することが好ましい。このように傾斜板を設けることにより、被処理水中で浮上した汚泥が流出部を含まない部分に集まりやすくなり、嫌気性反応槽からの汚泥の流出を抑えることができる。   When the partition member is provided in the anaerobic reaction tank, it is preferable that the inclined plate is provided in the water to be treated held in the anaerobic reaction tank. In this case, it is preferable that the upper end of the inclined plate is connected to the partition member or is located at or above or below a portion not including the outflow portion, and the lower end is preferably located below the portion including the outflow portion. By providing the inclined plate in this manner, the sludge that has floated in the water to be treated is easily collected at a portion not including the outflow portion, and the outflow of the sludge from the anaerobic reaction tank can be suppressed.

嫌気性反応槽は、底部から水面までの高さが、嫌気性反応槽内の最大水平方向長さよりも短いことが好ましい。この場合、嫌気性反応槽は水平方向の長さに対して深さ方向の長さが短く形成されるため、供給管から液体を供給したり撹拌板によって撹拌したりして汚泥を沈降させる際、汚泥が嫌気性反応槽の底部まで沈降しやすくなる。その結果、嫌気性反応槽内でより多くの汚泥が嫌気性処理に有効に寄与しやすくなり、嫌気性反応槽全体の処理性能を高めることができる。   In the anaerobic reaction tank, the height from the bottom to the water surface is preferably shorter than the maximum horizontal length in the anaerobic reaction tank. In this case, since the anaerobic reaction tank is formed to have a shorter length in the depth direction than the length in the horizontal direction, when the sludge is settled by supplying the liquid from the supply pipe or stirring by the stirring plate. In addition, the sludge tends to settle to the bottom of the anaerobic reaction tank. As a result, more sludge tends to effectively contribute to the anaerobic treatment in the anaerobic reaction tank, and the processing performance of the entire anaerobic reaction tank can be improved.

本発明はまた、被処理水を上向流式で嫌気性反応槽に導入し、嫌気性汚泥と接触させることにより嫌気性処理を行う嫌気性処理工程と、略水平方向に向いた開口を有し、前記開口が嫌気性反応槽内の被処理水の上部１／３の領域または水面より上方に位置するように設けられた液体の供給管から、前記開口を通じて、嫌気性反応槽内の被処理水に液体を供給する液体供給工程とを有する水処理方法も提供する。本発明の水処理方法によれば、前記のように形成された供給管の開口から液体を供給することにより、嫌気性反応槽に保持された被処理水の水面近くを撹乱して、略水平方向の水の流れを形成することができる。そのため、ガスを抱き込んだ形で水面に浮上した汚泥からガスを効果的に分離でき、これにより水面に浮上した汚泥の沈降を促し、嫌気性反応槽内の被処理水の汚泥濃度を高く維持することができる。開口は、嫌気性反応槽内の水面を含む位置に設けられていることがより好ましい。   The present invention also has an anaerobic treatment step in which the water to be treated is introduced into the anaerobic reaction tank in an upward flow manner and is brought into contact with anaerobic sludge to perform an anaerobic treatment, and an opening directed substantially horizontally. Then, from the liquid supply pipe provided such that the opening is located in the upper one-third region of the water to be treated in the anaerobic reaction tank or above the surface of the water, the opening in the anaerobic reaction tank is passed through the opening. A liquid supply step of supplying a liquid to the treated water. According to the water treatment method of the present invention, by supplying the liquid from the opening of the supply pipe formed as described above, the vicinity of the surface of the water to be treated held in the anaerobic reaction tank is disturbed, and the liquid is treated substantially horizontally. A directional water flow can be formed. Therefore, the gas can be effectively separated from the sludge floating on the water surface in the form of embracing the gas, thereby promoting the sedimentation of the sludge floating on the water surface and maintaining the sludge concentration of the water to be treated in the anaerobic reaction tank high. can do. The opening is more preferably provided at a position including the water surface in the anaerobic reaction tank.

本発明の水処理方法は、被処理水を上向流式で嫌気性反応槽に導入し、嫌気性汚泥と接触させることにより嫌気性処理する嫌気性処理工程と、嫌気性反応槽内の被処理水の上部１／３の領域に設けられた撹拌板により、被処理水を撹拌する撹拌工程とを有するものであってもよい。この場合、嫌気性反応槽に保持された被処理水の上部１／３の領域に設けた撹拌板により被処理水を撹拌することにより、水面に浮上した汚泥を揺動して汚泥からガスを分離して、汚泥を沈降させることができ、被処理水の汚泥濃度を高く維持することができる。   The water treatment method of the present invention comprises: an anaerobic treatment step in which water to be treated is introduced into an anaerobic reaction tank in an upward flow manner, and is subjected to anaerobic treatment by contact with anaerobic sludge; A stirring step of stirring the water to be treated by a stirring plate provided in the upper third area of the treated water may be employed. In this case, the water to be treated is stirred by the stirring plate provided in the upper one-third region of the water to be treated held in the anaerobic reaction tank, so that the sludge floating on the surface of the water is swung to remove gas from the sludge. The sludge can be separated and settled, and the sludge concentration of the water to be treated can be kept high.

液体供給工程は、１時間当たり２秒以上２０分以下行うことが好ましい。また、液体の１日当たりの供給量が、被処理水の１日当たりの流入量の１／２００以上１／１０以下であることが好ましい。このように液体供給工程を行うことにより、汚泥の細分化を抑えつつ、汚泥の沈降を促して、嫌気性反応槽からの汚泥の流出を好適に抑えることができる。   The liquid supply step is preferably performed for 2 seconds or more and 20 minutes or less per hour. Further, it is preferable that the daily supply amount of the liquid is 1/200 or more and 1/10 or less of the daily inflow amount of the water to be treated. By performing the liquid supply step in this way, it is possible to suppress sludge sedimentation while promoting sludge sedimentation, and to appropriately suppress the outflow of sludge from the anaerobic reaction tank.

本発明の水処理方法は、嫌気性処理工程で得られた処理水を濃縮して濃縮汚泥を得る濃縮工程をさらに有し、濃縮汚泥を供給管に移送して前記液体として用いることが好ましい。嫌気性処理工程で得られた処理水を濃縮し、得られた濃縮汚泥を供給管に移送して前記液体として用いることにより、嫌気性反応槽内の被処理水の汚泥濃度を高く維持することができる。   It is preferable that the water treatment method of the present invention further includes a concentration step of concentrating the treated water obtained in the anaerobic treatment step to obtain concentrated sludge, and transferring the concentrated sludge to a supply pipe and using it as the liquid. Concentrating the treated water obtained in the anaerobic treatment step, transferring the obtained concentrated sludge to the supply pipe and using it as the liquid, to maintain a high sludge concentration of the water to be treated in the anaerobic reaction tank. Can be.

嫌気性反応槽は処理水の流出部を有し、水面を、流出部を含む部分と流出部を含まない部分とに分ける仕切り部材が設けられることが好ましい。この場合、前記液体を、流出部を含まない部分またはその下方に供給するか、撹拌板を、流出部を含まない部分の下方に設けることが好ましい。嫌気性反応槽をこのように構成し、液体の供給や被処理水の撹拌を行うことにより、被処理水の水面の流出部を含まない部分に浮上した汚泥が流出部から流出しにくくなり、流出部を含まない部分に浮上した汚泥を効率的に沈降させることができる。さらに嫌気性反応槽に保持された被処理水中には傾斜板が設けられることが好ましく、傾斜板は、上端が、仕切り部材に接続するか、流出部を含まない部分またはその上方もしくは下方に位置し、下端が流出部を含む部分の下方に位置するように設けられることが好ましい。このように傾斜板を設けることにより、被処理水中で浮上した汚泥が流出部を含まない部分に集まりやすくなり、嫌気性反応槽からの汚泥の流出を抑えることができる。   The anaerobic reaction tank preferably has an outflow portion of the treated water, and is preferably provided with a partition member for dividing the water surface into a portion including the outflow portion and a portion not including the outflow portion. In this case, it is preferable to supply the liquid to a portion not including the outflow portion or below the portion, or to provide a stirring plate below the portion not including the outflow portion. By configuring the anaerobic reaction tank in this manner and supplying the liquid and stirring the water to be treated, the sludge floating on the portion of the surface of the water to be treated that does not include the outflow portion becomes less likely to flow out of the outflow portion, Sludge that has floated to a portion that does not include the outflow portion can be settled efficiently. Further, an inclined plate is preferably provided in the water to be treated held in the anaerobic reaction tank, and the inclined plate has an upper end connected to a partition member, or a portion not including an outflow portion, or a position above or below the portion. It is preferable that the lower end is provided below the portion including the outflow portion. By providing the inclined plate in this manner, the sludge that has floated in the water to be treated is easily collected at a portion not including the outflow portion, and the outflow of the sludge from the anaerobic reaction tank can be suppressed.

嫌気性反応槽は、底部から水面までの高さが、嫌気性反応槽内の最大水平方向長さよりも短いことが好ましい。この場合、嫌気性反応槽は水平方向の長さに対して深さ方向の長さが短く形成されるため、液体供給工程や撹拌工程で汚泥を沈降させる際、汚泥が嫌気性反応槽の底部まで沈降しやすくなる。その結果、嫌気性反応槽内でより多くの汚泥が嫌気性処理に有効に寄与しやすくなり、嫌気性処理性能を高めることができる。   In the anaerobic reaction tank, the height from the bottom to the water surface is preferably shorter than the maximum horizontal length in the anaerobic reaction tank. In this case, the length of the anaerobic reaction tank is shorter in the depth direction than the length in the horizontal direction. Therefore, when the sludge is settled in the liquid supply step or the stirring step, the sludge is formed at the bottom of the anaerobic reaction tank. Settling easily. As a result, more sludge tends to effectively contribute to the anaerobic treatment in the anaerobic reaction tank, and the anaerobic treatment performance can be improved.

本発明の水処理装置および水処理方法によれば、略水平方向に向いた開口を有し、当該開口が嫌気性反応槽に保持された被処理水の水面近傍に位置するように設けられた供給管から、液体を供給したり、あるいは水面近傍で被処理水を撹拌することにより、嫌気性反応槽内の水面に浮上した汚泥からガスを効果的に分離できる。これにより、嫌気性反応槽内の水面に浮上した汚泥を沈降させて、被処理水の汚泥濃度を高く維持することができ、嫌気性処理を好適に行うことができる。   ADVANTAGE OF THE INVENTION According to the water treatment apparatus and the water treatment method of this invention, it has the substantially horizontally oriented opening, and the said opening was provided so that it might be located near the surface of the to-be-processed water hold | maintained in the anaerobic reaction tank. By supplying the liquid from the supply pipe or stirring the water to be treated near the water surface, the gas can be effectively separated from the sludge floating on the water surface in the anaerobic reaction tank. Thereby, the sludge floating on the water surface in the anaerobic reaction tank is settled, the sludge concentration of the water to be treated can be kept high, and the anaerobic treatment can be suitably performed.

本発明の水処理装置の構成例を表す。1 shows a configuration example of a water treatment apparatus of the present invention. 本発明の水処理装置の構成例を表す。1 shows a configuration example of a water treatment apparatus of the present invention. 本発明の水処理装置の構成例を表す。1 shows a configuration example of a water treatment apparatus of the present invention. 本発明の水処理装置の構成例を表す。1 shows a configuration example of a water treatment apparatus of the present invention.

本発明は、嫌気性反応槽を備えた水処理装置と、嫌気性反応槽にて被処理水を嫌気性汚泥と接触させて嫌気性処理する水処理方法に関する。本発明は、嫌気性反応槽で被処理水を上向流式で嫌気性汚泥と接触させて嫌気性処理する際に、嫌気性反応槽から嫌気性汚泥が流出するのを抑え、嫌気性処理を効率的に行うことを可能とするものである。   The present invention relates to a water treatment apparatus provided with an anaerobic reaction tank, and a water treatment method for performing anaerobic treatment by contacting treated water with anaerobic sludge in the anaerobic reaction tank. The present invention suppresses the outflow of anaerobic sludge from the anaerobic reaction tank when anaerobic treatment is performed by contacting the water to be treated with the anaerobic sludge in an anaerobic reaction tank in an upward flow manner. Can be performed efficiently.

本発明ではまず、嫌気性反応槽に被処理水を導入し、嫌気性汚泥と接触させることにより嫌気性処理を行う（嫌気性処理工程）。被処理水は、嫌気性反応槽内で処理される水を意味し、少なくとも有機物を含有していればよい。本発明において処理対象となる原水、すなわち嫌気性反応槽に導入される水としては、例えば、トイレや洗濯、風呂、台所排水等を含む下水やし尿等の生活排水が挙げられる。これ以外にも、畜産糞尿、食品工場や製紙工場等から発生する工場排水、厨房排水、これらの処理に伴い発生するプロセス排水等も対象となる。   In the present invention, first, water to be treated is introduced into an anaerobic reaction tank, and anaerobic treatment is performed by bringing the water into contact with anaerobic sludge (anaerobic treatment step). The water to be treated means water to be treated in the anaerobic reaction tank, and may contain at least an organic substance. The raw water to be treated in the present invention, that is, the water introduced into the anaerobic reaction tank, includes, for example, domestic wastewater such as sewage and human waste including toilet, laundry, bath, kitchen wastewater, and the like. In addition, livestock manure, factory wastewater generated from food factories and paper mills, kitchen wastewater, and process wastewater generated due to these treatments are also included.

原水の性状は特に制限されない。例えば、嫌気性処理により、あるいはそれに簡易な後処理（例えば固液分離処理等）を組み合わせることにより、河川等に放流可能なレベルまでＢＯＤ(生物学的酸素要求量)濃度を低減するためには、原水のＢＯＤ濃度は平均で３０ｍｇ／Ｌ〜６００ｍｇ／Ｌ程度であることが好ましいが、ＢＯＤ濃度がさらに高くてもよい（例えば、２，０００ｍｇ／Ｌ以下）。   The properties of the raw water are not particularly limited. For example, to reduce the BOD (biological oxygen demand) concentration to a level that can be discharged to rivers, etc. by anaerobic treatment or by combining it with a simple post-treatment (eg, solid-liquid separation treatment) The BOD concentration of the raw water is preferably about 30 mg / L to 600 mg / L on average, but the BOD concentration may be higher (for example, 2,000 mg / L or less).

嫌気性反応槽には、嫌気性汚泥を含む被処理水が保持されている。嫌気性汚泥にはメタン菌等の嫌気性微生物が含まれており、嫌気性反応槽では、メタン菌等の働きにより、被処理水中の有機物がバイオガス（メタンガスや炭酸ガス）に変換されたり、資化される。嫌気性汚泥は分散状態で被処理水中に浮遊していてもよく、粒状に形成されたグラニュール汚泥として存在していてもよい。汚泥の分散状態には、汚泥がフロック状やスカム状に分散している状態も含まれる。なお、本明細書において、「嫌気性汚泥」を単に「汚泥」と称する場合がある。   The anaerobic reaction tank holds treated water containing anaerobic sludge. Anaerobic sludge contains anaerobic microorganisms such as methane bacteria. In the anaerobic reaction tank, organic substances in the water to be treated are converted into biogas (methane gas and carbon dioxide gas) by the action of methane bacteria and the like. Assimilated. The anaerobic sludge may be suspended in the water to be treated in a dispersed state, or may be present as granular sludge formed in a granular form. The dispersion state of the sludge includes a state in which the sludge is dispersed in a floc shape or a scum shape. In this specification, “anaerobic sludge” may be simply referred to as “sludge”.

嫌気性反応槽の形状は特に限定されず、代表的には、略円筒形や略直方体が挙げられる。嫌気性反応槽は、ＵＡＳＢ法で用いられる反応槽のように鉛直方向に長い形状であってもよく、一般的な水処理の反応槽のように水平方向に長い形状であってもよい。例えば、本発明の水処理装置を浄化槽に適用する場合は、嫌気性反応槽は、軸が横方向になるように設置された略円筒形の形状とすることができる。   The shape of the anaerobic reaction tank is not particularly limited, and typically includes a substantially cylindrical shape or a substantially rectangular parallelepiped. The anaerobic reaction tank may have a vertically long shape like a reaction tank used in the UASB method, or may have a horizontally long shape like a general water treatment reaction tank. For example, when the water treatment device of the present invention is applied to a septic tank, the anaerobic reaction tank can have a substantially cylindrical shape installed so that the axis is in the horizontal direction.

嫌気性反応槽は上向流式であり、被処理水の流入部と、当該流入部よりも上方に位置する処理水の流出部を有する。これにより、嫌気性反応槽には、流出部の高さまで嫌気性汚泥を含む被処理水が保持される。なお、流出部の高さとは、嫌気性反応槽から処理水が流出する最も低い位置の高さを意味し、例えば嫌気性反応槽の側面に排出部として開口が設けられ、この開口から自然流下により処理水が流出する場合は、当該開口の最も低い位置を意味する。なお流出部は、処理水が流出する部分であれば、開口に限らず、例えば、越流堰によって形成されてもよい。流出部から流出した処理水の一部は嫌気性反応槽に返送されてもよい。   The anaerobic reaction tank is of an upward flow type, and has an inflow portion of the water to be treated and an outflow portion of the treated water located above the inflow portion. Thereby, the anaerobic reaction tank holds the water to be treated including the anaerobic sludge up to the height of the outflow portion. The height of the outflow portion refers to the height of the lowest position where the treated water flows out of the anaerobic reaction tank. For example, an opening is provided on the side surface of the anaerobic reaction tank as a discharge portion, and the natural water flows down from this opening. When the treated water flows out, the lowest position of the opening is meant. The outflow portion is not limited to the opening as long as the treated water flows out, and may be formed by, for example, an overflow weir. A part of the treated water flowing out of the outlet may be returned to the anaerobic reaction tank.

嫌気性反応槽は、被処理水が上向流式で導入されることにより、嫌気性反応槽内で汚泥が嫌気性反応槽内で沈降しにくくなり、汚泥が被処理水中で浮遊状態で存在しやすくなる。これにより、被処理水と汚泥との接触効率を高めて、例えば不溶性のＢＯＤ成分であっても効率的な除去（分解）が可能となる。なお嫌気性反応槽は、流出部が流入部よりも上方に位置することで、全体で見て嫌気性反応槽内に被処理水の上向きの流れが形成されるものであればよい。   In the anaerobic reaction tank, the sludge is hard to settle in the anaerobic reaction tank in the anaerobic reaction tank because the water to be treated is introduced in the upward flow type, and the sludge is present in a floating state in the water to be treated. Easier to do. As a result, the contact efficiency between the water to be treated and the sludge is increased, and for example, even insoluble BOD components can be efficiently removed (decomposed). The anaerobic reaction tank may be any tank in which the outflow portion is located above the inflow portion, so that an upward flow of the water to be treated is formed in the anaerobic reaction tank as a whole.

流入部は、嫌気性反応槽の下部に設けられる。具体的には、嫌気性反応槽内の被処理水の下部１／３の領域に設けられ、好ましくは下部１／４の領域に設けられ、より好ましくは下部１／５の領域に設けられる。流入部は嫌気性反応槽の底部近くに設けられてもよく、これにより嫌気性反応槽で汚泥が沈降するのを防ぎやすくなる。   The inflow part is provided in a lower part of the anaerobic reaction tank. Specifically, it is provided in the lower 1/3 region of the water to be treated in the anaerobic reaction tank, preferably in the lower 1/4 region, and more preferably in the lower 1/5 region. The inflow section may be provided near the bottom of the anaerobic reaction tank, which makes it easier to prevent sludge from settling in the anaerobic reaction tank.

流入部は、嫌気性反応槽の下部に、複数箇所設けられることが好ましい。これにより、嫌気性反応槽内での被処理水の上向きの流れを均一に形成しやすくなる。また、被処理水と汚泥との接触効率も高めやすくなる。   The inflow section is preferably provided at a plurality of locations below the anaerobic reaction tank. This makes it easier to uniformly form an upward flow of the water to be treated in the anaerobic reaction tank. Further, the contact efficiency between the water to be treated and the sludge can be easily increased.

流入部からは、被処理水が上方向に導入されても、被処理水が下方向に導入されても、また水平方向や斜め方向に導入されてもよい。例えば、流入部において、被処理水が下方向または斜め下方向に導入されれば、汚泥が嫌気性反応槽の底部に堆積するのを防ぎやすくなる。なお汚泥中には、メタン菌等の嫌気性微生物以外に、砂等の比較的比重が大きい固形分が含まれる場合があることから、嫌気性反応槽内でこれらの固形分を比重分離させてもよい。すなわち、砂等の比較的比重の大きい固形分を嫌気性反応槽内で沈降させて、比較的比重の小さい嫌気性微生物等である汚泥を被処理水中に浮遊させることにより、砂等を嫌気性反応槽から排除しやすくしてもよい。この場合は、流入部から被処理水を上方向または斜め上方向に導入することが好ましい。また、流入部より下方に、嫌気性反応槽内で沈降した汚泥（固形分）の抜出部を設けてもよい。   From the inflow portion, the water to be treated may be introduced upward, the water to be treated may be introduced downward, or may be introduced horizontally or obliquely. For example, if the water to be treated is introduced downward or obliquely downward in the inflow section, it becomes easier to prevent sludge from accumulating on the bottom of the anaerobic reaction tank. In addition, in addition to anaerobic microorganisms such as methane bacteria, sludge may contain solids having a relatively large specific gravity, such as sand, so that these solids are separated in the anaerobic reaction tank by specific gravity. Is also good. In other words, sand and other anaerobic microorganisms are settled in the anaerobic reaction tank, and sludge, which is an anaerobic microorganism having a relatively small specific gravity, is suspended in the water to be treated, thereby making the sand and the like anaerobic. You may make it easy to remove from a reaction tank. In this case, it is preferable to introduce the water to be treated upward or obliquely upward from the inflow portion. Further, an extraction part for sludge (solid content) settled in the anaerobic reaction tank may be provided below the inflow part.

嫌気性反応槽には、散気装置や撹拌装置（例えば、プロペラ式撹拌装置）等、嫌気性反応槽内を均質化する機構が設けられないことが好ましく、特に嫌気性反応槽の下部にこれらの装置が設けられないことが好ましい。散気装置や撹拌装置は被処理水の撹拌手段として機能するが、汚泥が過度に細分化されて分散性が高まることを抑制する点から、これらの装置によって被処理水が広範囲にわたって強制的に撹拌されないことが好ましい。なお、汚泥掻き寄せ機等、汚泥を細分化しない非常に低速で移動する機構は具備されていてもよい。   It is preferable that the anaerobic reaction tank is not provided with a mechanism for homogenizing the inside of the anaerobic reaction tank, such as a diffuser or a stirrer (for example, a propeller type stirrer). It is preferable that the above device is not provided. A diffuser or agitator functions as a means for agitating the water to be treated.However, in order to prevent the sludge from being excessively fragmented and increasing the dispersibility, these devices force the water to be treated over a wide range. Preferably, it is not agitated. It should be noted that a mechanism that moves the sludge at a very low speed, such as a sludge scraper, that does not subdivide the sludge, may be provided.

嫌気性反応槽に保持される被処理水の浮遊物質濃度（ＳＳ濃度）は、効率的な嫌気性処理を実現する点から、１，０００ｍｇ／Ｌ以上が好ましく、５，０００ｍｇ／Ｌ以上がより好ましく、１０，０００ｍｇ／Ｌ以上がさらに好ましい。一方、嫌気性反応槽に保持される被処理水の浮遊物質濃度の上限は、嫌気性反応槽からの汚泥の流出を勘案すると、一般的には５０，０００ｍｇ／Ｌ以下となる。被処理水の浮遊物質濃度は、スタンダードメソッド（Standard Methods for the Examination of Water and Wastewater）に記載の方法に基づいて求める。なお、測定用の試料は、嫌気性反応槽の流入部から流出部まで範囲の異なる高さの１０箇所以上から採取する。この際、流入部から流出部までの高さ範囲でできるだけ均等間隔となるよう採取位置を調整する。これら採取した試料を等量混合し、測定に供する。   The concentration of suspended solids (SS concentration) in the water to be treated held in the anaerobic reaction tank is preferably 1,000 mg / L or more, and more preferably 5,000 mg / L or more from the viewpoint of achieving efficient anaerobic treatment. It is more preferably 10,000 mg / L or more. On the other hand, the upper limit of the concentration of suspended solids in the water to be treated held in the anaerobic reaction tank is generally 50,000 mg / L or less in consideration of the outflow of sludge from the anaerobic reaction tank. The concentration of suspended solids in the water to be treated is determined based on the method described in Standard Methods for the Examination of Water and Wastewater. In addition, the sample for a measurement is taken from 10 or more places with different heights from the inflow part to the outflow part of the anaerobic reaction tank. At this time, the sampling position is adjusted so that the intervals are as uniform as possible in the height range from the inflow section to the outflow section. An equal amount of these collected samples is mixed and provided for measurement.

嫌気性反応槽内の被処理水の酸化還元電位（ＯＲＰ）は、嫌気性細菌の活動を促進する点から、−１５０ｍＶ以下であることが好ましく、−２００ｍＶ以下がより好ましく、−２５０ｍＶ以下がさらに好ましく、−３００ｍＶ以下が特に好ましい。嫌気性反応槽中の被処理水の酸化還元電位の下限は特に限定されないが、例えば、−４５０ｍＶ以上が好ましい。   The oxidation-reduction potential (ORP) of the water to be treated in the anaerobic reaction tank is preferably -150 mV or less, more preferably -200 mV or less, further preferably -250 mV or less, from the viewpoint of promoting the activity of anaerobic bacteria. It is particularly preferably −300 mV or less. The lower limit of the oxidation-reduction potential of the water to be treated in the anaerobic reaction tank is not particularly limited, but is preferably, for example, -450 mV or more.

嫌気性反応槽における被処理水の上向流の流速は、汚泥（特に嫌気性細菌）の沈降を防ぎつつ、嫌気性反応槽からの汚泥の流出を抑える点から適宜定めればよい。なお、被処理水と汚泥との接触効率を高めて、できるだけ効率的な処理を実現する点から、汚泥は分散状態で嫌気性反応槽内に保持されることが好ましく、このような汚泥の流出を抑える点から、被処理水の上向流の線速度は１．５ｍ／ｈ未満が好ましく、１．０ｍ／ｈ未満がより好ましく、０．８ｍ／ｈ以下がさらに好ましい。被処理水の上向流をこのような線速度に調節することにより、嫌気性汚泥は、グラニュールを形成するよりもむしろ分散状態で存在しやすくなり、被処理水との接触性向上による処理水質の向上が期待できる。この際、嫌気性反応槽からの汚泥の流出を抑える点から、嫌気性反応槽の下部に汚泥の高濃度部分が形成され、上部に汚泥の低濃度部分が形成されてもよく、また汚泥の高濃度部分と低濃度部分の間には汚泥界面が形成されてもよい。被処理水の上向流の線速度の下限については、例えば、０．０５ｍ／ｈ以上が好ましく、０．１ｍ／ｈ以上がより好ましく、これにより汚泥の完全な沈降を防止して、汚泥の分散状態を維持しやすくなる。被処理水の上向流の線速度は、嫌気性反応槽への被処理水の供給量を、嫌気性反応槽の水平断面積で除することにより求めることができる。嫌気性反応槽の水平断面積は、嫌気性反応槽の流入部から流出部までの高さ方向の部分に保持される被処理水の容積（嫌気性反応槽の有効容積）を、嫌気性反応槽の流入部から流出部までの高さ（水深）で除することにより求められる。   The upward flow velocity of the water to be treated in the anaerobic reaction tank may be appropriately determined from the viewpoint of preventing the sludge (especially anaerobic bacteria) from settling and suppressing the outflow of sludge from the anaerobic reaction tank. In order to increase the contact efficiency between the water to be treated and the sludge and to achieve the most efficient treatment, the sludge is preferably held in a dispersed state in the anaerobic reaction tank. In view of suppressing the above, the linear velocity of the upward flow of the water to be treated is preferably less than 1.5 m / h, more preferably less than 1.0 m / h, and even more preferably 0.8 m / h or less. By adjusting the upward flow of the water to be treated to such a linear velocity, the anaerobic sludge is likely to exist in a dispersed state rather than forming granules, and the treatment by improving the contact with the water to be treated is performed. Water quality can be improved. At this time, in order to suppress the outflow of sludge from the anaerobic reaction tank, a high-concentration portion of sludge may be formed at a lower portion of the anaerobic reaction tank, and a low-concentration portion of sludge may be formed at an upper portion. A sludge interface may be formed between the high concentration portion and the low concentration portion. The lower limit of the linear velocity of the upward flow of the water to be treated is, for example, preferably 0.05 m / h or more, more preferably 0.1 m / h or more, thereby preventing complete settling of the sludge, It becomes easy to maintain a dispersed state. The linear velocity of the upward flow of the water to be treated can be determined by dividing the supply amount of the water to be treated to the anaerobic reaction tank by the horizontal sectional area of the anaerobic reaction tank. The horizontal cross-sectional area of the anaerobic reactor is determined by the volume of the water to be treated (the effective volume of the anaerobic reactor) held in the height direction from the inlet to the outlet of the anaerobic reactor. It is determined by dividing by the height (water depth) from the inflow part to the outflow part of the tank.

被処理水の嫌気性反応槽の滞留時間（水理学的滞留時間；ＨＲＴ）は、所望の処理水性状に応じて適宜設定すればよく、例えば、１時間以上が好ましく、２時間以上がより好ましく、また２４時間以下が好ましく、１２時間以下がより好ましく、８時間以下がさらに好ましい。被処理水の嫌気性反応槽の滞留時間は、嫌気性反応槽への被処理水の供給量を嫌気性反応槽の有効容積で除することにより求められる。   The residence time of the anaerobic reaction tank for the water to be treated (hydraulic residence time; HRT) may be appropriately set according to the desired treatment aqueous state, and is, for example, preferably 1 hour or more, more preferably 2 hours or more. Also, it is preferably 24 hours or less, more preferably 12 hours or less, and even more preferably 8 hours or less. The residence time of the water to be treated in the anaerobic reaction tank is determined by dividing the supply amount of the water to be treated to the anaerobic reaction tank by the effective volume of the anaerobic reaction tank.

ところで嫌気性反応槽では、被処理水を嫌気性処理することによりメタンガス等が発生するが、処理に伴って、汚泥の一部がガスを抱き込んで嫌気性反応槽内の水面まで浮上する。このように浮上した汚泥は、そのまま放置すると嫌気性反応槽から流出し、その結果、嫌気性反応槽内での嫌気性細菌濃度が低下し、処理性能の低下を招く。そこで本発明では、嫌気性反応槽に保持された被処理水の水面近傍から液体を供給している。これにより、水面に浮上した汚泥が揺動されてガスが汚泥から分離し、汚泥の沈降が促され、被処理水の汚泥濃度を高く維持することが可能となる。   By the way, in the anaerobic reaction tank, methane gas or the like is generated by anaerobic treatment of the water to be treated, but with the treatment, a part of the sludge embraces the gas and floats to the water surface in the anaerobic reaction tank. The sludge thus floated flows out of the anaerobic reaction tank if left as it is, and as a result, the concentration of anaerobic bacteria in the anaerobic reaction tank decreases, resulting in a decrease in treatment performance. Therefore, in the present invention, the liquid is supplied from the vicinity of the surface of the water to be treated held in the anaerobic reaction tank. Thereby, the sludge floating on the water surface is swung, the gas is separated from the sludge, sedimentation of the sludge is promoted, and the sludge concentration of the water to be treated can be kept high.

液体の供給は、嫌気性反応槽に保持された被処理水の水面に浮上した汚泥を沈降させることを目的に行われる。本発明者らが検討したところ、ガスを抱き込んだ形で水面に浮上した汚泥からガスを分離するためには、水面近くの水を撹乱させることが効果的であり、特に水面近くで略水平方向の水の流れを形成することで、汚泥の下に保持されたガスが効率的に除去され、汚泥の沈降を促すことができることが分かった。そのために、本発明では、略水平方向に向き、嫌気性反応槽内の水面近傍に位置した開口を有する供給管を設けている。このように形成された供給管から液体を供給することにより、液体が供給管の開口から略水平方向に吐出され、水面近くに略水平方向の流れを形成することができる。   The supply of the liquid is performed for the purpose of causing the sludge floating on the surface of the water to be treated held in the anaerobic reaction tank to settle. The present inventors have studied and found that in order to separate gas from sludge that floated on the surface of water in a form that embraces the gas, it is effective to disturb water near the surface of the water, and in particular, it is substantially horizontal near the surface of the water. It has been found that by forming a water flow in the direction, the gas retained under the sludge can be efficiently removed and the settling of the sludge can be promoted. For this purpose, in the present invention, a supply pipe is provided which is oriented in a substantially horizontal direction and has an opening located near the water surface in the anaerobic reaction tank. By supplying the liquid from the supply pipe formed as described above, the liquid is discharged in a substantially horizontal direction from the opening of the supply pipe, and a substantially horizontal flow can be formed near the water surface.

なお本発明者らは、水面に浮上した汚泥からガスを除去する方法として、水面の上方からスプレーする方法も検討したが、この方法では汚泥の下側に保持されたガスを効果的に除去し、また汚泥の流出を抑制することは難しいことが分かった。特に、フロック状やスカム状の汚泥（凝集作用により形成した浮遊質の汚泥集合体）の場合は、汚泥の下にガスが大量に保持されやすいため、水面の上からスプレーするよりも、水面近くで略水平方向の流れを形成することが有効となる。また、水面の上からスプレーすると、汚泥集合体が細かく破壊されて分散性が高まり、かえって汚泥の流出が起こりやすくなる場合もある。しかし、水面近くで略水平方向の流れを形成することにより、汚泥の過度の細分化が抑制され、汚泥の沈降性を高めることができる。   In addition, the present inventors also studied a method of spraying gas from above the water surface as a method of removing gas from the sludge floating on the water surface.However, in this method, the gas retained below the sludge is effectively removed. It was also found that it was difficult to control sludge outflow. In particular, in the case of floc or scum-like sludge (floating sludge aggregate formed by coagulation), a large amount of gas is likely to be held under the sludge, so that it is closer to the water surface than to spray from above the water surface. Thus, it is effective to form a flow in a substantially horizontal direction. In addition, when spraying from above the water surface, the sludge aggregate is finely broken, dispersibility is enhanced, and on the contrary, the sludge may easily flow out. However, by forming a substantially horizontal flow near the water surface, excessive fragmentation of the sludge is suppressed, and sedimentation of the sludge can be enhanced.

液体の供給管は、嫌気性反応槽内の水面近傍に液体を吐出するように開口が設けられている。供給管から吐出する液体の種類は特に限定されず、当該液体は汚泥等の固形分を含むものであってもよい。液体としては、原水、嫌気性反応槽内の被処理水、処理水、嫌気性汚泥を含む被処理水または処理水、水（水道水、工水、地下水、河川水等）、薬液等が挙げられる。なお、処理水性状を低下させず、また用役費を低減する点から、液体としては、処理水または嫌気性汚泥を含む処理水を用いることが好ましい。   The liquid supply pipe is provided with an opening so as to discharge the liquid near the water surface in the anaerobic reaction tank. The type of liquid discharged from the supply pipe is not particularly limited, and the liquid may include a solid such as sludge. Examples of the liquid include raw water, water to be treated in an anaerobic reaction tank, treated water, treated or treated water containing anaerobic sludge, water (tap water, industrial water, groundwater, river water, etc.), and chemicals. Can be In addition, it is preferable to use treated water or treated water containing anaerobic sludge as the liquid from the viewpoint of not reducing the treated water properties and reducing utility costs.

供給管の開口は、嫌気性反応槽内の水面（嫌気性反応槽に保持された被処理水の水面）より下にあってもよく、上にあってもよく、水面を含む位置に設けられてもよい。供給管の開口が嫌気性反応槽内の水面より下にある場合、供給管の開口は、嫌気性反応槽に保持された被処理水の上部に位置すればよく、具体的には、嫌気性反応槽に保持された被処理水の上部１／３の領域に位置すればよい。好ましくは、供給管の開口は、嫌気性反応槽に保持された被処理水の上部１／４の領域に位置し、上部１／５の領域に位置することがより好ましい。このような位置に供給管の開口を設ければ、嫌気性反応槽に保持された被処理水の水面近くに略水平方向の流れを形成しやすくなるとともに、供給管から液体を被処理水中に吐出した際に、汚泥の細分化が抑えられ、汚泥の沈降性を高めることができる。供給管の開口は、嫌気性反応槽に保持された被処理水の水面近くに略水平方向の流れを効果的に形成する点から、開口の少なくとも一部が嫌気性反応槽内の水面から上方および下方に１５ｃｍ以内（すなわち鉛直方向に３０ｃｍの範囲内）にあるように設けられることが好ましく、１０ｃｍ以内がより好ましく、５ｃｍ以内がさらに好ましい。   The opening of the supply pipe may be below, above, or above the water surface in the anaerobic reaction tank (the surface of the water to be treated held in the anaerobic reaction tank). You may. When the opening of the supply pipe is below the surface of the water in the anaerobic reaction tank, the opening of the supply pipe may be located above the water to be treated held in the anaerobic reaction tank. What is necessary is just to locate in the upper 1/3 area | region of the to-be-processed water hold | maintained in the reaction tank. Preferably, the opening of the supply pipe is located in the upper 1/4 region of the water to be treated held in the anaerobic reaction tank, and more preferably in the upper 1/5 region. By providing the opening of the supply pipe at such a position, it becomes easy to form a substantially horizontal flow near the surface of the water to be treated held in the anaerobic reaction tank, and the liquid is supplied from the supply pipe into the water to be treated. At the time of discharge, the fragmentation of the sludge is suppressed, and the sedimentation of the sludge can be enhanced. The opening of the supply pipe is formed such that at least a part of the opening is above the water surface in the anaerobic reaction tank from the viewpoint of effectively forming a substantially horizontal flow near the surface of the water to be treated held in the anaerobic reaction tank. It is preferably provided so as to be within 15 cm below (that is, within a range of 30 cm in the vertical direction), preferably within 10 cm, more preferably within 5 cm.

開口は、嫌気性反応槽内の水面を含む位置に設けられることが特に好ましい。開口が嫌気性反応槽内の水面を含む位置に設けられれば、液体を開口から吐出することにより、嫌気性反応槽に保持された被処理水の水面近くを広範囲にわたって撹乱しやすくなる。すなわち、供給管から吐出された液体が、供給管の開口近くから遠くに至る広い範囲で被処理水面に着水し、これにより、広範囲にわたって被処理水の水面近くに略水平方向の流れを形成することができる。   The opening is particularly preferably provided at a position including a water surface in the anaerobic reaction tank. If the opening is provided at a position including the water surface in the anaerobic reaction tank, by discharging the liquid from the opening, it becomes easy to disturb the vicinity of the water to be treated held in the anaerobic reaction tank over a wide range. That is, the liquid discharged from the supply pipe lands on the water surface to be treated in a wide range from near to the opening of the supply pipe to a distance, thereby forming a substantially horizontal flow near the water surface of the water to be treated over a wide range. can do.

供給管の開口は、略水平方向に向いている。これにより、供給管の開口から液体が略水平方向に吐出されやすくなり、水面近くに略水平方向の流れを形成しやすくなる。例えば、供給管の開口が水面より上にある場合は、供給管の開口が略水平方向に向いていることにより、より遠くまで液体を届けることができ、また水面に達した液体は、当該液体の有する水平方向ベクトルにより、被処理水の水面近くに略水平方向の流れを効果的に形成することができる。供給管の開口が水面下にある場合は、供給管の開口が略水平方向に向いていることにより、開口付近から被処理水中に略水平方向の流れを形成することができる。なお開口から吐出された液体は、被処理水中では水の抵抗により、吐出方向に対して横に広がるような流れを形成するため、面状に広い範囲にわたって水面近くの水を撹乱させることができる。   The opening of the supply pipe is oriented substantially horizontally. This makes it easier for the liquid to be discharged in a substantially horizontal direction from the opening of the supply pipe, and to form a substantially horizontal flow near the water surface. For example, if the opening of the supply pipe is above the water surface, the liquid can be delivered to a greater distance because the opening of the supply pipe is oriented substantially in the horizontal direction. The horizontal direction vector has a substantially horizontal flow near the surface of the water to be treated. When the opening of the supply pipe is below the surface of the water, the flow of the supply pipe in the substantially horizontal direction can be formed in the water to be treated from near the opening because the opening of the supply pipe is oriented substantially in the horizontal direction. In addition, the liquid discharged from the opening forms a flow that spreads laterally with respect to the discharge direction due to the resistance of the water in the water to be treated, so that water near the water surface can be disturbed over a wide area in a planar manner. .

開口は、供給管の先端に形成されるものでもよく、供給管の途中に形成されるものでもよい。前者の場合は、供給管の端面に開口が形成されることとなり、後者の場合は、供給管の周面に開口が形成されることとなる。なお、供給管から液体を供給する際、所望の方向に液体を吐出することが容易になる点から、開口は供給管の先端に形成することが好ましい。   The opening may be formed at the tip of the supply pipe or may be formed in the middle of the supply pipe. In the former case, an opening is formed on the end face of the supply pipe, and in the latter case, an opening is formed on the peripheral surface of the supply pipe. In addition, when supplying the liquid from the supply pipe, the opening is preferably formed at the tip of the supply pipe from the viewpoint that the liquid can be easily discharged in a desired direction.

供給管の先端に開口が形成される場合、供給管は、先端にいくに従い内径が小さくなるように形成されていてもよく、これにより供給管の開口から液体を勢いよく吐出することができる。なお、供給管は、先端にいくに従い内径が大きくなるように形成されていてもよく、先端まで内径が変わらないように形成されていてもよい。   When an opening is formed at the tip of the supply pipe, the supply pipe may be formed so that the inner diameter becomes smaller toward the tip, whereby the liquid can be vigorously discharged from the opening of the supply pipe. Note that the supply pipe may be formed so that the inner diameter increases toward the distal end, or may be formed so that the inner diameter does not change up to the distal end.

供給管には、開口が１つのみ設けられても、複数設けられてもよい。供給管は、途中で分岐するものであってもよく、分岐したそれぞれに開口が設けられてもよい。もちろん、供給管は分岐しないものであってもよい。開口の形状や供給管の断面形状は、円形、楕円形、卵形、多角形、不定形等、特に限定されない。   The supply pipe may be provided with only one opening or a plurality of openings. The supply pipe may be branched in the middle, and an opening may be provided in each of the branched pipes. Of course, the supply pipe may not be branched. The shape of the opening and the sectional shape of the supply pipe are not particularly limited, such as a circle, an ellipse, an oval, a polygon, and an irregular shape.

本発明では、供給管の開口が水平面に対して±２０°以内の方向に向いている場合に、略水平方向に向いているものとする。なお、水平面に対する角度は、上方を正とする。供給管の開口は、好ましくは、水平面に対して±１５°以内の方向に向いており、より好ましくは、水平面に対して±１０°以内の方向に向いている。開口の向く角度は、開口が供給管の端面に形成される場合は、供給管の先端部分の内径中心の延在方向に基づき定める。開口が供給管の周面に形成される場合は、開口の中心を通る直線であって、供給管の内径中心と直角に交わるように引いた直線の延在方向に基づき定める。開口の中心や供給管の内径中心は、開口や供給管断面内縁の形状の重心から求める。   In the present invention, when the opening of the supply pipe is oriented in a direction within ± 20 ° with respect to the horizontal plane, the supply pipe is assumed to be oriented substantially horizontally. Note that the angle with respect to the horizontal plane is positive at the top. The opening of the supply tube is preferably oriented within ± 15 ° with respect to the horizontal plane, and more preferably oriented within ± 10 ° with respect to the horizontal plane. When the opening is formed on the end face of the supply pipe, the angle at which the opening faces is determined based on the extending direction of the center of the inner diameter of the distal end portion of the supply pipe. When the opening is formed in the peripheral surface of the supply pipe, the opening is determined based on a straight line passing through the center of the opening and extending in a direction perpendicular to the center of the inner diameter of the supply pipe. The center of the opening and the center of the inner diameter of the supply pipe are determined from the center of gravity of the shape of the opening and the inner edge of the cross section of the supply pipe.

供給管の開口は、略水平方向に向いている限り、水平面における開口方向（水平面に投射した開口方向）は特に限定されない。例えば、嫌気性反応槽に液体の供給管の開口が１個だけ設けられる場合は、開口は、嫌気性反応槽内の水面の水平面重心に対して時計回りを正として±３０°以内の方向に向いていることが好ましく、±２０°以内の方向に向いていることがより好ましい。この場合、０°の方向は水面の水平面重心方向となる。このように開口を設けることにより、嫌気性反応槽に保持された被処理水の水面近くを広範囲に撹乱して、効率的に汚泥の沈降を促すことができる。嫌気性反応槽に液体の供給管の開口が２個以上設けられる場合は、開口を設ける位置に応じて、できるだけ広範囲にわたって被処理水の水面近くを撹乱できるよう、開口の向く方向を適宜設定すればよい。この場合、例えば、嫌気性反応槽内で旋回流が形成されるように、液体の供給管の開口を設けることが好ましい。なお、液体の供給管の開口が１個だけ設けられる場合であっても、嫌気性反応槽内にガイド板を設けるなどして、旋回流が形成されるようにしてもよい。   The opening direction in the horizontal plane (the opening direction projected on the horizontal plane) is not particularly limited as long as the opening of the supply pipe is oriented substantially in the horizontal direction. For example, when only one opening of the liquid supply pipe is provided in the anaerobic reaction tank, the opening is in a direction within ± 30 ° with respect to the center of gravity of the horizontal surface of the water surface in the anaerobic reaction tank as a positive clockwise direction. Preferably, and more preferably in a direction within ± 20 °. In this case, the direction of 0 ° is the direction of the horizontal plane center of gravity of the horizontal surface. By providing such an opening, the vicinity of the surface of the water to be treated held in the anaerobic reaction tank is widely disturbed, and the sludge settling can be efficiently promoted. When two or more liquid supply pipe openings are provided in the anaerobic reaction tank, the direction in which the openings face is appropriately set so as to disturb the surface of the water to be treated as widely as possible according to the position where the openings are provided. I just need. In this case, for example, it is preferable to provide an opening of a liquid supply pipe so that a swirling flow is formed in the anaerobic reaction tank. In addition, even when only one opening of the liquid supply pipe is provided, a swirling flow may be formed by providing a guide plate in the anaerobic reaction tank.

本発明では、上記のように形成された開口を有する液体の供給管から、当該開口を通じて、液体を嫌気性反応槽に保持された被処理水に供給する（液体供給工程）。液体の供給は、常時行ってもよいが、ある程度の量の汚泥が水面まで浮上した段階で液体の供給を行って、汚泥の沈降を促すことが好ましい。従って、液体の供給は間欠的に行うことが好ましい。液体の供給を間欠的に行うことにより、当該液体の使用量を減らすことができるとともに、必要以上に液体を供給することにより汚泥が細分化するのを防ぐことができる。なお、液体供給工程は、嫌気性処理工程と同時に行ってもよく、別々に行ってもよい。   In the present invention, the liquid is supplied from the liquid supply pipe having the opening formed as described above to the water to be treated held in the anaerobic reaction tank through the opening (liquid supply step). The liquid may be supplied at all times, but it is preferable to supply the liquid at a stage where a certain amount of sludge has risen to the surface of the water to promote the settling of the sludge. Therefore, it is preferable to supply the liquid intermittently. By intermittently supplying the liquid, the amount of use of the liquid can be reduced, and sludge can be prevented from being fragmented by supplying the liquid more than necessary. The liquid supply step may be performed simultaneously with the anaerobic treatment step, or may be performed separately.

汚泥の浮上の程度は、嫌気性処理により発生するガス量に応じて変化する。つまり、処理負荷や処理条件に応じて変化する。そのため液体の供給頻度を一義的に定めることは難しいが、例えば、液体の供給頻度は、２４時間に１回以上が好ましく、１２時間に１回以上がより好ましく、６時間に１回以上がさらに好ましく、また１０分に１回以下が好ましく、２０分に１回以下がより好ましい。   The degree of sludge floating depends on the amount of gas generated by the anaerobic treatment. That is, it changes according to the processing load and processing conditions. Therefore, it is difficult to determine the supply frequency of the liquid unambiguously. For example, the supply frequency of the liquid is preferably at least once every 24 hours, more preferably at least once every 12 hours, and more preferably at least once every 6 hours. Preferably, it is preferably once or less every 10 minutes, and more preferably once or less every 20 minutes.

液体の供給時間、すなわち液体供給工程を行う時間は、１時間当たり２０分以下が好ましく、１５分以下がより好ましく、１２分以下がさらに好ましい。液体の供給時間をこのような範囲に調整することで、液体を供給することにより汚泥が過度に細分化するのを防ぐことができる。液体を供給するポンプ等の稼働に要するエネルギーを低減する観点からは、液体の供給時間をさらに短くすることもでき、例えば１時間当たり１０分以下であってもよく、８分以下であってもよく、５分以下であってもよく、３分以下であってもよい。液体の供給時間の下限については、実施例でも実証されるように、例えば１時間当たり２秒以上が好ましく、５秒以上がより好ましく、１０秒以上がさらに好ましく、１５秒以上がさらにより好ましい。なお、ここで説明した液体の供給時間とは、１時間当たりの平均供給時間を表し、例えば、２４時間のトータルの液体供給時間を測定し、それを１時間当たりに換算することで求められる。液体の供給時間は、例えば、ポンプの稼働時間から求めることができる。   The liquid supply time, that is, the time for performing the liquid supply step is preferably 20 minutes or less per hour, more preferably 15 minutes or less, and even more preferably 12 minutes or less. By adjusting the supply time of the liquid to such a range, it is possible to prevent the sludge from being excessively fragmented by supplying the liquid. From the viewpoint of reducing energy required for operation of a pump or the like for supplying a liquid, the supply time of the liquid can be further shortened. For example, the supply time may be 10 minutes or less per hour, or 8 minutes or less. The time may be 5 minutes or less, or 3 minutes or less. As demonstrated in the examples, the lower limit of the liquid supply time is, for example, preferably 2 seconds or more per hour, more preferably 5 seconds or more, still more preferably 10 seconds or more, and even more preferably 15 seconds or more. In addition, the liquid supply time described here indicates an average supply time per hour, and is obtained by, for example, measuring a total liquid supply time of 24 hours and converting it into one hour. The liquid supply time can be determined, for example, from the operation time of the pump.

液体の１日当たりの供給量は、被処理水の１日当たりの流入量の１／２００以上が好ましく、１／１５０以上がより好ましく、１／１００以上がさらに好ましく、また１／１０以下が好ましく、１／１５以下がより好ましく、１／２０以下がさらに好ましい。このように液体の供給量を調整することで、汚泥の細分化を抑えつつ、汚泥の沈降を促して、嫌気性反応槽からの汚泥の流出を好適に抑制することができる。液体の供給量を低減する観点からは、液体の１日当たりの供給量は被処理水の１日当たりの流入量の１／２５以下であってもよく、１／３０以下であってもよい。なお、被処理水の流入量は、処理水の一部を嫌気性反応槽に返送する場合は、その返送分を含まない量を意味する。   The daily supply amount of the liquid is preferably 1/200 or more, more preferably 1/150 or more, more preferably 1/100 or more, and still more preferably 1/10 or less of the daily inflow amount of the water to be treated, 1/15 or less is more preferable, and 1/20 or less is still more preferable. By adjusting the supply amount of the liquid as described above, it is possible to promote the sludge sedimentation while suppressing fragmentation of the sludge, and to appropriately suppress the outflow of the sludge from the anaerobic reaction tank. From the viewpoint of reducing the supply amount of the liquid, the supply amount of the liquid per day may be 1/25 or less or 1/30 or less of the daily inflow amount of the water to be treated. In addition, when returning a part of treated water to an anaerobic reaction tank, the inflow amount of to-be-processed water means the amount which does not include the returned part.

供給管からの液体の供給速度は、嫌気性反応槽内の被処理水の水面近くを効果的に撹乱させる点から、ある程度速い流速で行うことが好ましく、例えば、０．２ｍ／ｓ以上が好ましく、０．３ｍ／ｓ以上がより好ましく、０．４ｍ／ｓ以上がさらに好ましい。一方、あまり勢いよく液体を供給しても汚泥を細かく解砕するおそれがあることから、供給管からの液体の供給速度は、３．０ｍ／ｓ以下が好ましく、２．５ｍ／ｓ以下がより好ましく、２．０ｍ／ｓ以下がさらに好ましい。なお、供給管からの液体の供給速度は、供給管の開口における供給速度を意味する。   The supply speed of the liquid from the supply pipe is preferably set to a somewhat high flow rate from the viewpoint of effectively disturbing the vicinity of the water to be treated in the anaerobic reaction tank, and for example, is preferably 0.2 m / s or more. , 0.3 m / s or more, more preferably 0.4 m / s or more. On the other hand, even if the liquid is supplied too vigorously, the sludge may be finely crushed. Therefore, the liquid supply speed from the supply pipe is preferably 3.0 m / s or less, more preferably 2.5 m / s or less. Preferably, it is 2.0 m / s or less. In addition, the supply speed of the liquid from the supply pipe means the supply speed at the opening of the supply pipe.

本発明では、液体の供給管から液体を供給し、これにより被処理水の水面近くを撹乱する代わりに、嫌気性反応槽に保持された被処理水の上部に撹拌板を設けて、被処理水を撹拌してもよい（撹拌工程）。嫌気性反応槽内の被処理水の上部に設けた撹拌板を動かすことにより、水面に浮上した汚泥を揺動して汚泥からガスを分離し、汚泥を沈降させることができる。   In the present invention, the liquid is supplied from the liquid supply pipe, and instead of disturbing the vicinity of the surface of the water to be treated, a stirring plate is provided above the water to be treated held in the anaerobic reaction tank, and the liquid to be treated is provided. Water may be stirred (stirring step). By moving the stirring plate provided above the water to be treated in the anaerobic reaction tank, the sludge floating on the water surface is swung to separate gas from the sludge and settle the sludge.

撹拌板は、略水平方向の水流を起こすように形成されていることが好ましく、例えば、撹拌羽根のように回転移動するものであってもよく、略水平方向に平行移動するものであってもよく、またフラップのように往復回転移動するものであってもよい。撹拌板の断面形状は特に限定されず、四角形等の多角形、角の丸まった多角形、楕円形、円形、不定形等、特に限定されない。   The stirring plate is preferably formed so as to generate a substantially horizontal water flow.For example, the stirring plate may rotate and move like a stirring blade, or may move in a substantially horizontal direction in parallel. It may be one that reciprocally rotates like a flap. The cross-sectional shape of the stirring plate is not particularly limited, and is not particularly limited, such as a polygon such as a quadrangle, a polygon with rounded corners, an ellipse, a circle, and an irregular shape.

撹拌板は、嫌気性反応槽内の被処理水の上部１／３の領域に設けられ、好ましくは上部１／４の領域に設けられ、より好ましくは上部１／５の領域に設けられる。このような位置に撹拌板を設けることにより、嫌気性反応槽に保持された被処理水の水面近くに略水平方向の流れを形成しやすくなる。撹拌板はまた、少なくとも一部が水面から３０ｃｍ以内に位置するように設けられることが好ましく、２０ｃｍ以内がより好ましく、１５ｃｍ以内がさらに好ましい。   The stirring plate is provided in the upper 1/3 region of the water to be treated in the anaerobic reaction tank, preferably in the upper 1/4 region, and more preferably in the upper 1/5 region. By providing the stirring plate at such a position, it is easy to form a substantially horizontal flow near the surface of the water to be treated held in the anaerobic reaction tank. The stirring plate is preferably provided so that at least a part thereof is located within 30 cm from the water surface, more preferably within 20 cm, even more preferably within 15 cm.

撹拌工程は常時行ってもよいが、液体供給工程と同じように、間欠的に行うことが好ましい。撹拌工程を行う頻度は、２４時間に１回以上が好ましく、１２時間に１回以上がより好ましく、６時間に１回以上がさらに好ましく、また１０分に１回以下が好ましく、２０分に１回以下がより好ましい。撹拌工程を行う時間は、１時間当たり２０分以下であることが好ましく、１５分以下がより好ましく、１２分以下がさらに好ましく、また１時間当たり１０秒以上が好ましく、１５秒以上がより好ましい。撹拌板の稼働に要するエネルギーを低減する観点からは、撹拌工程の時間をさらに短くすることもでき、例えば１時間当たり１０分以下であってもよく、８分以下であってもよく、５分以下であってもよく、３分以下であってもよい。撹拌工程を行う頻度および時間に関する技術的意義は、液体供給工程の場合と同じである。撹拌工程は、嫌気性処理工程と同時に行ってもよく、別々に行ってもよい。   The stirring step may be performed at all times, but is preferably performed intermittently as in the liquid supply step. The frequency of performing the stirring step is preferably at least once every 24 hours, more preferably once every 12 hours, still more preferably once every 6 hours, and preferably once or less every 10 minutes, and preferably once or less every 20 minutes. The number of times is more preferable. The time for performing the stirring step is preferably 20 minutes or less per hour, more preferably 15 minutes or less, further preferably 12 minutes or less, and is preferably 10 seconds or more per hour, more preferably 15 seconds or more. From the viewpoint of reducing the energy required for the operation of the stirring plate, the time of the stirring step can be further shortened, and may be, for example, 10 minutes or less per hour, 8 minutes or less, or 5 minutes. Or less than 3 minutes. The technical significance of the frequency and time of performing the stirring step is the same as in the case of the liquid supply step. The stirring step may be performed simultaneously with the anaerobic treatment step, or may be performed separately.

撹拌板の移動速度は、嫌気性反応槽内の被処理水の水面近くを効果的に撹拌する点から、０．０５ｍ／ｓ以上が好ましく、０．１０ｍ／ｓ以上がより好ましく、０．１５ｍ／ｓ以上がさらに好ましい。一方、汚泥の解砕をできるだけ抑える点から、撹拌板の移動速度は、１．５ｍ／ｓ以下が好ましく、１．２ｍ／ｓ以下がより好ましく、１．０ｍ／ｓ以下がさらに好ましい。なお、撹拌板が回転移動や往復回転移動する場合は、回転中心と先端の中点における線速度を移動速度とする。   The moving speed of the stirring plate is preferably 0.05 m / s or more, more preferably 0.10 m / s or more, and 0.15 m / s or more, from the viewpoint of effectively stirring near the surface of the water to be treated in the anaerobic reaction tank. / S or more is more preferable. On the other hand, the moving speed of the stirring plate is preferably 1.5 m / s or less, more preferably 1.2 m / s or less, and still more preferably 1.0 m / s or less, from the viewpoint of minimizing sludge crushing. In the case where the stirring plate rotates or reciprocates, the linear velocity at the center between the rotation center and the tip is the moving speed.

液体供給工程や撹拌工程では、嫌気性反応槽内の被処理水の水面近くを撹乱させることにより、水面に浮いた、特にフロック等の集合体を形成した汚泥の再沈降を促しているが、集合体を形成した汚泥は、嫌気性反応槽内でできるだけ均一に存在していることが好ましい。従って、集合体を形成した汚泥が沈降する際、嫌気性反応槽のできるだけ底部まで沈降するように嫌気性反応槽が形成されていることが好ましく、これにより、嫌気性反応槽全体の処理性能を高めることができる。この点から、嫌気性反応槽は、水深が深くなり過ぎないように形成されていることが好ましい。一方、このような状況で嫌気性反応槽の処理量を確保するためには、嫌気性反応槽の設置面積を広くとることが必要となる。従って、嫌気性反応槽は、底部から被処理水の水面までの高さが、嫌気性反応槽内の最大水平方向長さよりも短く形成されていることが好ましく、前記最大水平方向長さの１／３以下となるように形成されていることがより好ましい。このように嫌気性反応槽を形成することにより、嫌気性反応槽の処理性能と処理量の両方を高めることができる。なお、嫌気性反応槽内の最大水平方向長さとは、嫌気性反応槽内の被処理水が保持される部分（空間）で、水平方向に最大となる長さを意味する。   In the liquid supply step and the stirring step, by disturbing the vicinity of the water to be treated in the anaerobic reaction tank, the re-sedimentation of the sludge floating on the water surface, particularly forming aggregates such as flocs, is promoted. It is preferable that the sludge forming the aggregate exists as uniformly as possible in the anaerobic reaction tank. Therefore, it is preferable that the anaerobic reaction tank is formed so that when the sludge forming the aggregates settles, the anaerobic reaction tank is settled as far as possible to the bottom of the anaerobic reaction tank. Can be enhanced. From this point, it is preferable that the anaerobic reaction tank is formed so that the water depth does not become too deep. On the other hand, in such a situation, in order to secure the throughput of the anaerobic reaction tank, it is necessary to increase the installation area of the anaerobic reaction tank. Therefore, the anaerobic reaction tank is preferably formed so that the height from the bottom to the surface of the water to be treated is shorter than the maximum horizontal length in the anaerobic reaction tank. More preferably, it is formed to be / 3 or less. By forming the anaerobic reaction tank in this way, both the processing performance and the throughput of the anaerobic reaction tank can be improved. The maximum horizontal length in the anaerobic reaction tank refers to the length (horizontal) of the portion (space) where the water to be treated in the anaerobic reaction tank is held.

嫌気性反応槽には、嫌気性反応槽内の水面を、流出部を含む部分と流出部を含まない部分とに分ける仕切り部材が設けられていることが好ましい。このとき、供給管の開口は、流出部を含まない部分またはその上方もしくは下方に位置するように設けられることが好ましい。詳細には、供給管の開口は、被処理水の水面の流出部を含まない部分か、当該流出部を含まない部分の鉛直上方の水面より上の空間か、当該流出部を含まない部分の鉛直下方の被処理水中に位置するように設けられることが好ましい。そして、液体供給工程において、液体を、流出部を含まない部分またはその下方（すなわち被処理水の水面の流出部を含まない部分か当該部分の鉛直下方の被処理水中）に供給することが好ましい。被処理水中に撹拌板を設ける場合は、撹拌板は、前記流出部を含まない部分の下方（すなわち流出部を含まない部分の鉛直下方の被処理水中）に設けられることが好ましい。このように嫌気性反応槽に仕切り部材を設けることにより、嫌気性反応槽に保持された被処理水の水面の流出部を含まない部分に浮上した汚泥が流出部から流出しにくくなり、流出部を含まない部分に浮上した汚泥を効率的に沈降させることができる。   Preferably, the anaerobic reaction tank is provided with a partition member for dividing the water surface in the anaerobic reaction tank into a portion including the outflow portion and a portion not including the outflow portion. At this time, the opening of the supply pipe is preferably provided so as to be located at a portion not including the outflow portion or above or below the portion. In detail, the opening of the supply pipe is a portion not including the outflow portion of the water surface of the treated water, a space above the water surface vertically above the portion not including the outflow portion, or a portion not including the outflow portion. It is preferable to be provided so as to be located in the water to be treated vertically below. In the liquid supply step, it is preferable that the liquid be supplied to a portion not including the outflow portion or below the portion (that is, a portion not including the outflow portion on the surface of the water to be treated or the water to be treated vertically below the portion). . When the stirring plate is provided in the water to be treated, the stirring plate is preferably provided below the portion not including the outflow portion (that is, the water to be treated vertically below the portion not including the outflow portion). By providing the partition member in the anaerobic reaction tank in this manner, it becomes difficult for the sludge floating on the portion of the water to be treated held in the anaerobic reaction tank not including the outflow portion to flow out of the outflow portion, and The sludge that has floated on the portion that does not contain the sludge can be settled efficiently.

仕切り部材は、供給管の開口よりも下まで延在するように設けられることが好ましい（特に、供給管の開口が水面を含む位置かそれより下方に位置する場合）。このように仕切り部材を設けることにより、流出部を含まない部分に浮上した汚泥を効率的に沈降させることができる。   The partition member is preferably provided so as to extend below the opening of the supply pipe (particularly when the opening of the supply pipe is located at or below the position including the water surface). By providing the partition member in this manner, the sludge that has floated to a portion that does not include the outflow portion can be settled efficiently.

仕切り部材は、嫌気性反応槽内の水面において連続的に設けられ、両端が嫌気性反応槽の内面に接続していることが好ましいが、一部が断続的に設けられていてもよい。なお、水面における仕切り部材の断続部分の長さは、仕切り部材の延在部分の長さの２０％以下であることが好ましく、１０％以下であることがより好ましく、５％以下がさらに好ましい。ここで、仕切り部材の延在部分の長さは、仕切り部材が被処理水の水面より上に出ている部分の長さを意味し、仕切り部材の断続部分の長さは、仕切り部材が断続している部分の最短距離（隣接する延在部分の端部間距離や延在部分の端部と嫌気性反応槽内面との間の距離）の総和を意味する。   The partition member is preferably provided continuously on the water surface in the anaerobic reaction tank, and both ends are preferably connected to the inner surface of the anaerobic reaction tank, but a part thereof may be provided intermittently. The length of the intermittent portion of the partition member on the water surface is preferably 20% or less, more preferably 10% or less, and even more preferably 5% or less of the length of the extended portion of the partition member. Here, the length of the extending portion of the partition member means the length of the portion where the partition member is above the surface of the water to be treated, and the length of the intermittent portion of the partition member is the length of the intermittent portion of the partition member. It means the sum of the shortest distances of the portions (the distance between the ends of the adjacent extended portions and the distance between the ends of the extended portions and the inner surface of the anaerobic reaction tank).

仕切り部材は、流出部を含む部分よりも流出部を含まない部分の方が広くなるように設けられることが好ましい。より好ましくは、仕切り部材は、流出部を含まない部分の面積が流出部を含む部分の面積よりも１．５倍以上広くなるように設けられ、さらに好ましくは、２倍以上広くなるように設けられる。特に、後述するような傾斜板が設けられない場合は、このように仕切り部材が設けられることが好ましい。なお、仕切り部材が断続的に設けられる場合は、仕切り部材の断続部分を最短距離で結ぶことにより、流出部を含む部分と流出部を含まない部分を区分するものとする。   It is preferable that the partition member is provided so that a portion not including the outflow portion is wider than a portion including the outflow portion. More preferably, the partition member is provided so that the area of the portion that does not include the outflow portion is 1.5 times or more larger than the area of the portion that includes the outflow portion, and still more preferably, is provided so that it is twice or more. Can be In particular, when an inclined plate as described later is not provided, it is preferable that such a partition member is provided. When the partition member is provided intermittently, the portion including the outflow portion and the portion not including the outflow portion are separated by connecting the intermittent portions of the partition member at the shortest distance.

嫌気性反応槽では、被処理水中で浮上した汚泥が、流出部を含まない部分に集まるように形成されていることが好ましい。この点から、嫌気性反応槽の被処理水中には傾斜板が設けられることが好ましい。傾斜板は少なくとも一部が傾斜していればよく、傾斜部分は、鉛直断面で見て直線状に傾斜していてもよく、曲線状に傾斜していてもよく、またこれらの組み合わせでもよい。傾斜板は、上端が、仕切り部材に接続するか、流出部を含まない部分またはその上方もしくは下方に位置し、下端が流出部を含む部分の下方に位置するように設けられている。なお、傾斜板の上端が仕切り部材に接続する場合は、傾斜板と仕切り部材が一体的に形成されることとなる。傾斜板の上端が流出部を含まない部分の上方に位置する場合は、傾斜板の上端が流出部を含まない部分の鉛直上方の水面より上の空間に位置することとなり、傾斜板の上端が流出部を含まない部分の下方に位置する場合は、傾斜板の上端が流出部を含まない部分の鉛直下方の被処理水中に位置することとなる。傾斜板の上端が流出部を含まない部分に位置する場合は、傾斜板が仕切り部材の下方を横切り、傾斜板の上端が流出部を含まない部分に位置するように設けられることが好ましい。一方、傾斜板の下端は、流出部を含む部分の鉛直下方の被処理水中に位置する。このように傾斜板を設けることにより、流出部を含む部分の下方から汚泥が浮上する場合でも、汚泥が傾斜板に沿って浮上することで、被処理水の水面の流出部を含まない部分に浮上させることができる。その結果、浮上した汚泥が流出部を含まない部分に集まりやすくなり、また嫌気性反応槽からの汚泥の流出を抑えることができる。   In the anaerobic reaction tank, it is preferable that the sludge floating in the water to be treated is formed so as to collect in a portion not including the outflow portion. From this point, it is preferable that an inclined plate is provided in the water to be treated in the anaerobic reaction tank. It is sufficient that at least a part of the inclined plate is inclined, and the inclined portion may be inclined linearly when viewed in a vertical cross section, may be inclined curvedly, or may be a combination thereof. The inclined plate is provided so that the upper end is connected to the partition member or is located at or above or below a portion not including the outflow portion, and the lower end is located below the portion including the outflow portion. When the upper end of the inclined plate is connected to the partition member, the inclined plate and the partition member are integrally formed. If the upper end of the inclined plate is located above the part not including the outflow part, the upper end of the inclined plate will be located in the space above the water surface vertically above the part not including the outflow part, and the upper end of the inclined plate will be When it is located below the portion not including the outflow portion, the upper end of the inclined plate is located in the water to be treated vertically below the portion not including the outflow portion. When the upper end of the inclined plate is located at a portion not including the outflow portion, the inclined plate is preferably provided so as to cross under the partition member, and the upper end of the inclined plate is located at a portion not including the outflow portion. On the other hand, the lower end of the inclined plate is located in the water to be treated vertically below the portion including the outflow portion. By providing the inclined plate in this manner, even when the sludge floats from below the portion including the outflow portion, the sludge floats along the inclined plate, so that the sludge does not include the outflow portion on the surface of the water to be treated. Can be surfaced. As a result, the sludge that has floated is likely to collect in a portion not including the outflow portion, and the outflow of sludge from the anaerobic reaction tank can be suppressed.

嫌気性反応槽の後段には、濃縮槽が設けられることが好ましい。本発明では、嫌気性反応槽に液体の供給管や撹拌板を設けることにより、嫌気性反応槽内の被処理水の水面に浮上した汚泥を再沈降させて、嫌気性反応槽からの汚泥の流出を極力抑えるようにしているが、汚泥の一部は、処理水流に伴って嫌気性反応槽から流出してしまう場合がある。特に、嫌気性汚泥は比較的粒径が小さく、分散性も高いことから、その一部が嫌気性反応槽から流出しやすい。そのため、嫌気性反応槽からの流出水に含まれる汚泥を回収するために、嫌気性反応槽の後段に濃縮槽を設けることが好ましい。これにより、嫌気性処理工程で得られた処理水を濃縮して濃縮汚泥を得ることができる（濃縮工程）。また、これにより得られる分離液は固形分濃度が低減されたものとなるため、最終的に得られる処理水質の改善も期待できる。   It is preferable that a concentration tank is provided downstream of the anaerobic reaction tank. In the present invention, by providing a liquid supply pipe or a stirring plate in the anaerobic reaction tank, the sludge floating on the surface of the water to be treated in the anaerobic reaction tank is re-sedimented, and the sludge from the anaerobic reaction tank is removed. Although the outflow is minimized, a part of the sludge may flow out of the anaerobic reaction tank with the treated water flow. In particular, since anaerobic sludge has a relatively small particle size and high dispersibility, a part of the anaerobic sludge easily flows out of the anaerobic reaction tank. Therefore, in order to collect the sludge contained in the effluent from the anaerobic reaction tank, it is preferable to provide a concentration tank at a stage subsequent to the anaerobic reaction tank. Thereby, the concentrated sludge can be obtained by concentrating the treated water obtained in the anaerobic treatment step (concentration step). Further, since the separated liquid obtained by this method has a reduced solid content, improvement in the quality of the finally obtained treated water can be expected.

濃縮槽は、嫌気性反応槽の流出部に連通して設けられ、嫌気性反応槽の処理水が流入し、濃縮される。濃縮槽は、任意の固液分離手段により、処理水に含まれる汚泥を濃縮できるものであれば特に限定されず、例えば、沈殿分離、ろ過分離、膜分離、遠心分離等の分離手段を採用できる。これらの分離手段は、組み合わせて用いてもよい。ろ過分離や膜分離の場合は、洗浄や逆洗の際に発生した廃水を濃縮汚泥として用いることができる。   The concentration tank is provided in communication with the outlet of the anaerobic reaction tank, and the treated water from the anaerobic reaction tank flows in and is concentrated. The concentration tank is not particularly limited as long as the sludge contained in the treated water can be concentrated by any solid-liquid separation means. For example, separation means such as precipitation separation, filtration separation, membrane separation, and centrifugation can be employed. . These separation means may be used in combination. In the case of filtration separation or membrane separation, wastewater generated during washing or backwashing can be used as concentrated sludge.

濃縮槽では、固形分濃度が高められた濃縮汚泥と、固形分濃度が低下した分離液とが得られる。このようにして得られた濃縮汚泥は嫌気性反応槽に返送することが好ましく、これにより嫌気性反応槽の汚泥濃度を高く維持し、嫌気性反応槽における処理性能を高めることができる。   In the concentration tank, a concentrated sludge having an increased solid content and a separated liquid having a reduced solid content are obtained. It is preferable that the concentrated sludge thus obtained is returned to the anaerobic reaction tank, whereby the sludge concentration in the anaerobic reaction tank can be maintained high, and the processing performance in the anaerobic reaction tank can be improved.

濃縮汚泥は、液体の供給管に移送して、当該供給管から供給する液体として用いることが好ましい。これにより、供給管から液体を供給しても、嫌気性反応槽内の被処理水の希薄化を抑え、被処理水の汚泥濃度を高く維持することができる。従って、本発明の水処理装置には、濃縮汚泥を供給管に移送する移送手段が設けられることが好ましい。具体的には、濃縮槽と供給管とを繋ぐ返送流路が設けられ、返送流路にはポンプ等が設けられることが好ましい。   The concentrated sludge is preferably transferred to a liquid supply pipe and used as a liquid supplied from the supply pipe. Thereby, even if the liquid is supplied from the supply pipe, the dilution of the water to be treated in the anaerobic reaction tank can be suppressed, and the sludge concentration of the water to be treated can be kept high. Therefore, the water treatment apparatus of the present invention is preferably provided with a transfer means for transferring the concentrated sludge to the supply pipe. Specifically, it is preferable that a return flow path connecting the concentration tank and the supply pipe be provided, and a pump or the like be provided in the return flow path.

次に、本発明の水処理装置の構成例について、図面を参照して説明する。なお、本発明は、図面に示した実施態様に限定されない。   Next, a configuration example of the water treatment apparatus of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment shown in the drawings.

図１には、液体の供給管を備えた水処理装置の構成例を示した。図１に示した水処理装置は、被処理水２１の流入部２と、流入部２より上方に位置する処理水２２の流出部３とを有し、流出部３の高さまで嫌気性汚泥を含む被処理水２１が保持された、上向流式の嫌気性反応槽１と、嫌気性反応槽１に設けられた液体の供給管４とを有する。供給管４は、被処理水２１の上部１／３の領域または嫌気性反応槽１内の水面より上方に位置し、略水平方向に向いた開口５を有する。図１では、開口５が、嫌気性反応槽１内の水面を含む位置に設けられている。また、流出部３は、越流堰により形成されている。なお図面において、水面の位置は下向きの三角で示されている。   FIG. 1 shows a configuration example of a water treatment device provided with a liquid supply pipe. The water treatment apparatus shown in FIG. 1 has an inflow portion 2 of the water 21 to be treated and an outflow portion 3 of the treated water 22 located above the inflow portion 2. The anaerobic sludge reaches the height of the outflow portion 3. An anaerobic reaction tank 1 of an upward flow type in which the water 21 to be treated is held, and a liquid supply pipe 4 provided in the anaerobic reaction tank 1 are provided. The supply pipe 4 is located above the area of the upper third of the water 21 to be treated or above the water surface in the anaerobic reaction tank 1 and has an opening 5 oriented substantially horizontally. In FIG. 1, the opening 5 is provided at a position including the water surface in the anaerobic reaction tank 1. The outflow part 3 is formed by an overflow weir. In the drawings, the position of the water surface is indicated by a downward triangle.

図１に示した水処理装置では、被処理水２１を上向流式で嫌気性反応槽１に導入し、被処理水２１中の嫌気性汚泥と接触させることにより嫌気性処理を行う嫌気性処理工程と、供給管４の開口５から、嫌気性反応槽１に保持された被処理水２１に液体２３を供給する液体供給工程とを行うことにより、嫌気性反応槽１での嫌気処理を好適に行うことができる。すなわち、略水平方向に向いた開口５を有する供給管４から液体２３を供給することにより、被処理水２１の水面近くを撹乱して、被処理水２１の水面近くに略水平方向の水の流れを形成することができ、これにより、被処理水２１の水面に浮上した汚泥からガスを効果的に分離することができる。その結果、被処理水２１の水面に浮上した汚泥を沈降させて、嫌気性反応槽１からの汚泥の流出を防ぎ、被処理水２１の汚泥濃度を高く維持することができ、嫌気性反応槽１で嫌気性処理が好適に行われるようになる。   In the water treatment apparatus shown in FIG. 1, the anaerobic treatment in which the water to be treated 21 is introduced into the anaerobic reaction tank 1 in an upward flow manner and is brought into contact with the anaerobic sludge in the water to be treated 21. The anaerobic treatment in the anaerobic reaction tank 1 is performed by performing the treatment step and the liquid supply step of supplying the liquid 23 to the water to be treated 21 held in the anaerobic reaction tank 1 from the opening 5 of the supply pipe 4. It can be suitably performed. That is, by supplying the liquid 23 from the supply pipe 4 having the opening 5 oriented in a substantially horizontal direction, the liquid 23 is disturbed near the surface of the water 21 to be treated, and the substantially horizontal water is supplied near the surface of the water 21 to be treated. A flow can be formed, whereby gas can be effectively separated from sludge floating on the surface of the water 21 to be treated. As a result, the sludge floating on the surface of the water to be treated 21 is settled to prevent the sludge from flowing out of the anaerobic reaction tank 1, and the sludge concentration of the water to be treated 21 can be maintained at a high level. In step 1, the anaerobic treatment is suitably performed.

嫌気性反応槽１には、嫌気性反応槽１内の水面を、流出部３を含む部分と流出部３を含まない部分とに分ける仕切り部材７が設けられ、供給管４の開口５が、流出部３を含まない部分に位置するように設けられている。このように仕切り部材７を設けることにより、流出部３を含まない部分に浮上した汚泥が流出部３から流出しにくくなり、流出部３を含まない部分に浮上した汚泥を効率的に沈降させることができる。   The anaerobic reaction tank 1 is provided with a partition member 7 that divides the water surface in the anaerobic reaction tank 1 into a portion including the outflow portion 3 and a portion not including the outflow portion 3. It is provided so as to be located at a portion not including the outflow portion 3. By providing the partition member 7 in this manner, it becomes difficult for the sludge floating on the portion not including the outflow portion 3 to flow out of the outflow portion 3, and the sludge floating on the portion not including the outflow portion 3 is efficiently settled. Can be.

図２および図３には、図１に示した水処理装置に傾斜板と濃縮槽を設けた構成例を示した。なお、図２および図３に水処理装置に関する下記の説明では、図１の説明と重複する説明を省く。   FIGS. 2 and 3 show a configuration example in which an inclined plate and a concentration tank are provided in the water treatment apparatus shown in FIG. In the following description of the water treatment apparatus in FIGS. 2 and 3, the description that overlaps with the description of FIG. 1 will be omitted.

図２および図３に示した水処理装置には、嫌気性反応槽１に保持された被処理水２１中に、上端が流出部３を含まない部分の下方に位置し、下端が流出部３を含む部分の下方に位置する傾斜板８が設けられている。傾斜板８を設けることにより、被処理水２１中で浮上した汚泥が流出部３を含まない部分に集まりやすくなり、嫌気性反応槽１からの汚泥の流出を抑えることができる。   In the water treatment apparatus shown in FIGS. 2 and 3, in the water 21 to be treated held in the anaerobic reaction tank 1, the upper end is located below the portion not including the outlet 3, and the lower end is located at the outlet 3. The inclined plate 8 is provided below the portion including. By providing the inclined plate 8, the sludge that has floated in the water 21 to be treated is easily collected at a portion that does not include the outflow portion 3, and the outflow of sludge from the anaerobic reaction tank 1 can be suppressed.

図２および図３では、嫌気性反応槽１の流出部３に連通して、嫌気性反応槽１の処理水２２が濃縮される濃縮槽１１が設けられ、さらに、濃縮槽１１で得られた濃縮汚泥２５を供給管４に移送する移送手段１３が設けられている。図では、移送手段１３として、濃縮槽１１と供給管４とを繋ぐ返送流路が設けられている。このように構成することにより、濃縮汚泥２５を、供給管４から供給する液体２３として用いることができる。嫌気性反応槽１から流出した処理水２２を濃縮槽１１で濃縮し、ここで得られた濃縮汚泥２５を供給管４から供給する液体２３として用いることにより、嫌気性反応槽１内の被処理水２１の希薄化を抑え、被処理水２１の汚泥濃度を高く維持することができる。濃縮槽１１からは、固形分濃度が低減された分離液２４が流出する。   In FIG. 2 and FIG. 3, a concentration tank 11 in which the treated water 22 of the anaerobic reaction tank 1 is concentrated is provided in communication with the outflow portion 3 of the anaerobic reaction tank 1, and further obtained in the concentration tank 11. A transfer means 13 for transferring the concentrated sludge 25 to the supply pipe 4 is provided. In the figure, a return channel connecting the concentration tank 11 and the supply pipe 4 is provided as the transfer means 13. With such a configuration, the concentrated sludge 25 can be used as the liquid 23 supplied from the supply pipe 4. The treated water 22 flowing out of the anaerobic reaction tank 1 is concentrated in the concentration tank 11, and the concentrated sludge 25 obtained here is used as the liquid 23 supplied from the supply pipe 4 so that the treated water 22 in the anaerobic reaction tank 1 can be treated. It is possible to suppress the dilution of the water 21 and keep the sludge concentration of the water 21 to be treated high. From the concentration tank 11, a separated liquid 24 having a reduced solid content concentration flows out.

なお図２では、濃縮槽１１が沈殿槽となっており、濃縮槽１１の下部に貯まった濃縮汚泥２５を、供給管４から供給する液体２３として用いている。図３では、濃縮槽１１にろ過層１２が設けられており、ろ過層１２の下から洗浄媒体を導入してろ過層１２を洗浄する際に発生する洗浄排水を濃縮汚泥２５として扱う。洗浄排水は、ろ過層１２の構成や洗浄媒体の種類（液体、気体）等に応じて、ろ過層１２の上方から取り出すことが有効な場合と、ろ過層１２の下方から取り出すことが有効な場合とがある。従って、どちらから洗浄排水を取り出すのかは、装置構成や洗浄条件に応じて適宜決めればよい。   In FIG. 2, the concentration tank 11 is a sedimentation tank, and the concentrated sludge 25 stored in the lower part of the concentration tank 11 is used as the liquid 23 supplied from the supply pipe 4. In FIG. 3, a filtration layer 12 is provided in a concentration tank 11, and washing wastewater generated when a cleaning medium is introduced from under the filtration layer 12 to wash the filtration layer 12 is treated as a concentrated sludge 25. Depending on the configuration of the filtration layer 12, the type of the cleaning medium (liquid, gas), etc., it is effective to take out the washing wastewater from above the filtration layer 12, and when it is effective to take it out from below the filtration layer 12. There is. Therefore, which one of the cleaning wastewater is taken out may be appropriately determined according to the apparatus configuration and the cleaning conditions.

図４には、撹拌板を備えた水処理装置の構成例を示した。なお、図４に示した水処理装置に関する下記の説明では、図１の説明と重複する説明を省く。   FIG. 4 shows a configuration example of a water treatment device provided with a stirring plate. Note that, in the following description of the water treatment apparatus shown in FIG. 4, description overlapping with the description of FIG. 1 will be omitted.

図４に示した水処理装置では、液体の供給管の代わりに、被処理水２１の上部１／３の領域に撹拌板６が設けられている。図４に示した水処理装置では、被処理水２１を上向流式で嫌気性反応槽１に導入し、被処理水２１中の嫌気性汚泥と接触させることにより嫌気性処理を行う嫌気性処理工程と、撹拌板６により被処理水２１を撹拌する撹拌工程とを行う。図４に示した水処理装置では、被処理水２１の上部に設けた撹拌板６を動かすことにより、被処理水２１の水面に浮上した汚泥を揺動して汚泥からガスを分離し、汚泥を沈降させることができ、被処理水２１の汚泥濃度を高く維持することができる。これにより、嫌気性反応槽１での嫌気処理を好適に行うことができる。   In the water treatment apparatus shown in FIG. 4, instead of the liquid supply pipe, the stirring plate 6 is provided in the upper third area of the water 21 to be treated. In the water treatment apparatus shown in FIG. 4, anaerobic treatment is performed in which the water 21 to be treated is introduced into the anaerobic reaction tank 1 in an upward flow manner and is brought into contact with anaerobic sludge in the water 21 to be treated. A treatment step and a stirring step of stirring the water to be treated 21 by the stirring plate 6 are performed. In the water treatment apparatus shown in FIG. 4, by moving the stirring plate 6 provided above the water to be treated 21, the sludge floating on the surface of the water to be treated 21 is swung to separate gas from the sludge, and Can be settled, and the sludge concentration of the water 21 to be treated can be kept high. Thereby, the anaerobic treatment in the anaerobic reaction tank 1 can be suitably performed.

図４ではまた、嫌気性反応槽１に保持された被処理水２１中に、上端が仕切り部材７に接続し、下端が流出部３を含む部分の下方に位置する傾斜板８が設けられている。図４では、傾斜板８は、仕切り部材７と一体化されている。このように傾斜板８を形成しても、被処理水２１中で浮上した汚泥が流出部３を含まない部分に集まりやすくなり、嫌気性反応槽１からの汚泥の流出を抑えることができる。   In FIG. 4, an inclined plate 8 having an upper end connected to the partition member 7 and a lower end positioned below a portion including the outflow portion 3 is provided in the water 21 to be treated held in the anaerobic reaction tank 1. I have. In FIG. 4, the inclined plate 8 is integrated with the partition member 7. Even if the inclined plate 8 is formed in this manner, the sludge floating in the water to be treated 21 tends to collect on the portion not including the outflow portion 3, and the outflow of the sludge from the anaerobic reaction tank 1 can be suppressed.

本願は、２０１５年３月２７日に出願された日本国特許出願第２０１５−０６７１３２号に基づく優先権の利益を主張するものである。２０１５年３月２７日に出願された日本国特許出願第２０１５−０６７１３２号の明細書の全内容が、本願に参考のために援用される。   This application claims the benefit of priority based on Japanese Patent Application No. 2015-0673132 filed on March 27, 2015. The entire contents of the specification of Japanese Patent Application No. 2015-0673132 filed on March 27, 2015 are incorporated herein by reference.

以下に、実施例を示すことにより本発明を更に詳細に説明するが、本発明の範囲はこれらに限定されるものではない。   Hereinafter, the present invention will be described in more detail by way of examples, but the scope of the present invention is not limited thereto.

有効容積９ｍ3、水深２ｍの嫌気性反応槽を用いて、下水（下水処理場の初沈流入水）の嫌気性処理を行った。反応槽は、底部に流入部が設けられ、上部に流出部が設けられ、液体の供給管が、水面を含む位置に開口が略水平方向に向くように設けられていた。また反応槽には、仕切り部材と傾斜板が一体形成された部材が設けられ、仕切り部材によって水面が流出部を含む部分と流出部を含まない部分とに分けられていた。原水を上向流式で反応槽に供給して嫌気性処理を行った。実施例では、３０分に１回、供給管から処理水を５秒間供給し、水面を撹乱した。供給管からの処理水の１日当たりの供給量は、原水の流入量の１／１００とした。比較例では、供給管からの処理水の供給は行わなかった。Anaerobic treatment of sewage (first sedimentation inflow water of a sewage treatment plant) was performed using an anaerobic reaction tank having an effective volume of 9 m 3 and a depth of 2 m. In the reaction tank, an inflow portion was provided at the bottom portion, an outflow portion was provided at the top portion, and a liquid supply pipe was provided at a position including a water surface so that an opening thereof was oriented substantially in a horizontal direction. Further, the reaction tank was provided with a member in which a partition member and an inclined plate were integrally formed, and the water surface was divided into a portion including the outflow portion and a portion not including the outflow portion by the partition member. Raw water was supplied to the reaction tank in an upward flow manner to perform anaerobic treatment. In the example, once every 30 minutes, treated water was supplied from the supply pipe for 5 seconds to disturb the water surface. The daily supply of treated water from the supply pipe was 1/100 of the inflow of raw water. In the comparative example, the supply of the treated water from the supply pipe was not performed.

実施例と比較例の処理結果を表１に示す。原水は、ＢＯＤ、全ＣＯＤCr、ＳＳの各濃度を測定し、処理水は溶解性ＣＯＤCr、有機酸の各濃度を測定した。ＢＯＤ、ＣＯＤ、ＳＳ、有機酸の各濃度はスタンダードメソッド（Standard Methods for the Examination of Water and Wastewater）に記載の方法に従い測定した。また、反応槽のスカム厚と沈降汚泥厚を、反応槽の水平方向４ヶ所について測定し、その平均値を求めた。Table 1 shows the processing results of the example and the comparative example. For raw water, each concentration of BOD, total COD Cr and SS was measured, and for treated water, each concentration of soluble COD Cr and organic acid was measured. Each concentration of BOD, COD, SS, and organic acid was measured according to the method described in Standard Methods for the Examination of Water and Wastewater. Further, the scum thickness and the settled sludge thickness of the reaction tank were measured at four locations in the horizontal direction of the reaction tank, and the average value was obtained.

実施例と比較例では原水性状に大差はなく、いずれも嫌気性処理により原水中のＣＯＤが分解されて低分子化されたが、処理水質には大きな差が見られた。実施例では、水面の撹乱操作を行うことにより、反応層内で汚泥が浮上してスカム形成することが抑えられた。そのため、反応槽からの汚泥の流出が抑えられ、反応槽内で嫌気性処理に有効に寄与する汚泥濃度を高く維持することができた。その結果、嫌気性処理を順調に行うことができ、原水中のＣＯＤが有機酸を経てメタンガスと二酸化炭素までスムーズに分解され、有機酸の蓄積が認められず、処理水ＣＯＤ濃度も低くすることができた。一方、比較例では水面の撹乱操作を行わなかったため、反応槽内で汚泥が浮上してスカムが形成され、反応槽からの汚泥の流出が高濃度で認められた。比較例では、原水中のＣＯＤが分解して生成した有機酸のさらなる分解（メタンガスと二酸化炭素への分解）がスムーズに進行せず、有機酸濃度の上昇が認められ、処理水ＣＯＤ濃度が実施例の倍以上の濃度となった。   There was no significant difference in the raw water state between the example and the comparative example. In both cases, COD in the raw water was decomposed to lower molecular weight by anaerobic treatment, but a large difference was observed in the quality of the treated water. In the example, the scum formation due to the sludge floating in the reaction layer was suppressed by performing the water surface disturbance operation. Therefore, the outflow of sludge from the reaction tank was suppressed, and the concentration of sludge effectively contributing to anaerobic treatment in the reaction tank could be maintained at a high level. As a result, anaerobic treatment can be performed smoothly, COD in raw water is smoothly decomposed into methane gas and carbon dioxide via organic acids, no accumulation of organic acids is recognized, and COD concentration in treated water is reduced. Was completed. On the other hand, in the comparative example, since the operation of disturbing the water surface was not performed, the sludge floated in the reaction tank to form scum, and the outflow of the sludge from the reaction tank was observed at a high concentration. In the comparative example, the organic acid generated by the decomposition of COD in the raw water (decomposition into methane gas and carbon dioxide) did not proceed smoothly, and the organic acid concentration increased. The concentration was more than double that of the example.

Figure 0006640837
Figure 0006640837

本発明は、下水やし尿等生活排水、下水処理やし尿処理に伴い発生するプロセス排水、食品工場、紙パルプ工場、化学工場等から発生する工場排水、家畜糞尿、畜産廃棄物の処理により発生する排水等の処理に用いることができる。本発明の水処理装置は、例えば、下水処理場、し尿処理場、各種廃水施設、浄化槽等に適用することができる。   The present invention is generated by treatment of domestic wastewater such as sewage and human waste, process wastewater generated by sewage treatment and human waste treatment, factory wastewater generated from food factories, pulp and paper mills, chemical factories, livestock manure, and livestock waste. It can be used for treatment of waste water and the like. The water treatment apparatus of the present invention can be applied to, for example, sewage treatment plants, human waste treatment plants, various wastewater facilities, septic tanks, and the like.

１：嫌気性反応槽
２：流入部
３：流出部
４：供給管
５：開口
６：撹拌板
７：仕切り部材
８：傾斜板
１１：濃縮槽
１２：ろ過層
１３：濃縮汚泥の移送手段
２１：嫌気性反応槽内の被処理水
２２：処理水
２３：液体
２４：分離液
２５：濃縮汚泥1: Anaerobic reaction tank 2: Inflow section 3: Outflow section 4: Supply pipe 5: Opening 6: Stirring plate 7: Partition member 8: Inclined plate 11: Concentration tank 12: Filtration layer 13: Conveying means of concentrated sludge 21: Water to be treated in anaerobic reaction tank 22: Treated water 23: Liquid 24: Separated liquid 25: Condensed sludge

Claims (14)

被処理水の流入部と、前記流入部より上方に位置する処理水の流出部とを有し、前記流出部の高さまで嫌気性汚泥を含む被処理水が保持された、上向流式の嫌気性反応槽と、
前記嫌気性反応槽に設けられた液体の供給管とを有する水処理装置であって、
前記嫌気性反応槽には、水面を前記流出部を含む部分と前記流出部を含まない部分とに分ける仕切り部材が設けられ、
前記嫌気性反応槽に保持された被処理水中に傾斜板が設けられ、
前記傾斜板は、上端が前記流出部を含まない部分またはその上方もしくは下方に位置し、下端が前記流出部を含む部分の下方に位置し、
前記供給管は、前記嫌気性反応槽内の被処理水の上部１／３の領域または水面より上方に位置する開口を有し、前記開口が略水平方向に向いており、
前記供給管の開口は、前記流出部を含まない部分またはその上方もしくは下方に位置するように設けられていることを特徴とする水処理装置。 An inflow portion of the to-be-treated water, and an outflow portion of the treated water located above the inflow portion, wherein the to-be-treated water containing the anaerobic sludge is held up to the height of the outflow portion, and an upward flow type. An anaerobic reactor,
A water treatment device having a liquid supply pipe provided in the anaerobic reaction tank,
The anaerobic reaction tank is provided with a partition member for dividing a water surface into a portion including the outflow portion and a portion not including the outflow portion,
An inclined plate is provided in the water to be treated held in the anaerobic reaction tank,
The inclined plate has an upper end positioned above or below the portion not including the outflow portion, and a lower end positioned below a portion including the outflow portion,
The supply pipe has an opening located above the upper third of the water to be treated in the anaerobic reaction tank or above the water surface, and the opening is oriented substantially in a horizontal direction .
A water treatment apparatus , wherein the opening of the supply pipe is provided so as to be located at a portion not including the outflow portion or above or below the outflow portion . 前記開口は、前記嫌気性反応槽内の水面を含む位置に設けられている請求項１に記載の水処理装置。   The water treatment device according to claim 1, wherein the opening is provided at a position including a water surface in the anaerobic reaction tank. 前記供給管から供給される液体の供給時間は、１時間当たり２秒以上２０分以下である請求項１または２に記載の水処理装置。   The water treatment apparatus according to claim 1, wherein a supply time of the liquid supplied from the supply pipe is 2 seconds or more and 20 minutes or less per hour. 前記供給管から供給される液体の１日当たりの供給量は、前記被処理水の１日当たりの流入量の１／２００以上１／１０以下である請求項１〜３のいずれか一項に記載の水処理装置。   The daily supply amount of the liquid supplied from the supply pipe is 1/200 or more and 1/10 or less of the daily inflow amount of the water to be treated, according to any one of claims 1 to 3. Water treatment equipment. 前記水処理装置は、前記嫌気性反応槽の流出部に連通し、前記嫌気性反応槽の処理水が濃縮される濃縮槽と、
前記濃縮槽で得られた濃縮汚泥を前記供給管に移送する移送手段とを、さらに有し、
前記濃縮汚泥を前記液体として用いる請求項１〜４のいずれか一項に記載の水処理装置。 The water treatment device communicates with an outflow portion of the anaerobic reaction tank, a concentration tank in which the treated water of the anaerobic reaction tank is concentrated,
Transfer means for transferring the concentrated sludge obtained in the concentration tank to the supply pipe,
The water treatment apparatus according to any one of claims 1 to 4, wherein the concentrated sludge is used as the liquid. 被処理水の流入部と、前記流入部より上方に位置する処理水の流出部とを有し、前記流出部の高さまで嫌気性汚泥を含む被処理水が保持された、上向流式の嫌気性反応槽と、
前記嫌気性反応槽内の被処理水の上部１／３の領域に設けられた撹拌板とを有し、
前記嫌気性反応槽には、水面を前記流出部を含む部分と前記流出部を含まない部分とに分ける仕切り部材が設けられ、
前記嫌気性反応槽に保持された被処理水中に傾斜板が設けられ、
前記傾斜板は、上端が前記流出部を含まない部分またはその上方もしくは下方に位置し、下端が前記流出部を含む部分の下方に位置し、
前記撹拌板は、前記流出部を含まない部分の下方に設けられていることを特徴とする水処理装置。 An inflow portion of the to-be-treated water, and an outflow portion of the treated water located above the inflow portion, wherein the to-be-treated water containing the anaerobic sludge is held up to the height of the outflow portion, and an upward flow type. An anaerobic reactor,
Possess a stirring plate provided in the region of the upper third of the water to be treated in the anaerobic reaction vessel,
The anaerobic reaction tank is provided with a partition member for dividing a water surface into a portion including the outflow portion and a portion not including the outflow portion,
An inclined plate is provided in the water to be treated held in the anaerobic reaction tank,
The inclined plate has an upper end positioned above or below the portion not including the outflow portion, and a lower end positioned below a portion including the outflow portion,
The water treatment apparatus , wherein the stirring plate is provided below a portion not including the outflow portion . 前記嫌気性反応槽は、底部から水面までの高さが、前記嫌気性反応槽内の最大水平方向長さよりも短い請求項１〜６のいずれか一項に記載の水処理装置。 The water treatment apparatus according to any one of claims 1 to 6 , wherein the anaerobic reaction tank has a height from a bottom to a water surface shorter than a maximum horizontal length in the anaerobic reaction tank. 被処理水を上向流式で嫌気性反応槽に導入し、嫌気性汚泥と接触させることにより嫌気性処理を行う嫌気性処理工程と、
略水平方向に向いた開口を有し、前記開口が前記嫌気性反応槽内の被処理水の上部１／３の領域または水面より上方に位置するように設けられた液体の供給管から、前記開口を通じて、前記嫌気性反応槽内の被処理水に液体を供給する液体供給工程とを有する水処理方法であって、
前記嫌気性反応槽は処理水の流出部を有し、水面を前記流出部を含む部分と前記流出部を含まない部分とに分ける仕切り部材が設けられ、
前記嫌気性反応槽に保持された被処理水中に傾斜板が設けられ、
前記傾斜板は、上端が前記流出部を含まない部分またはその上方もしくは下方に位置し、下端が前記流出部を含む部分の下方に位置し、
前記液体供給工程において、前記液体を、前記流出部を含まない部分またはその下方に供給することを特徴とする水処理方法。 An anaerobic treatment step in which the water to be treated is introduced into the anaerobic reaction tank in an upward flow manner and is brought into contact with anaerobic sludge to perform anaerobic treatment;
A liquid supply pipe provided such that the opening has a substantially horizontal direction, and the opening is located above the upper third of the water to be treated in the anaerobic reaction tank or above the water surface; A liquid supply step of supplying a liquid to the water to be treated in the anaerobic reaction tank through the opening ,
The anaerobic reaction tank has an outflow portion of the treated water, and a partition member for dividing a water surface into a portion including the outflow portion and a portion not including the outflow portion is provided,
An inclined plate is provided in the water to be treated held in the anaerobic reaction tank,
The inclined plate has an upper end positioned above or below the portion not including the outflow portion, and a lower end positioned below a portion including the outflow portion,
In the liquid supply step, the liquid is supplied to a portion not including the outflow portion or to a lower portion thereof . 前記開口は、前記嫌気性反応槽内の水面を含む位置に設けられている請求項８に記載の水処理方法。 The water treatment method according to claim 8 , wherein the opening is provided at a position including a water surface in the anaerobic reaction tank. 前記液体供給工程を、１時間当たり２秒以上２０分以下行う請求項８または９に記載の水処理方法。 Water treatment method according to claim 8 or 9 wherein the liquid supplying step is carried out less than 20 minutes or 2 seconds per hour. 前記液体の１日当たりの供給量が、前記被処理水の１日当たりの流入量の１／２００以上１／１０以下である請求項８〜１０のいずれか一項に記載の水処理方法。 The water treatment method according to any one of claims 8 to 10 , wherein a daily supply amount of the liquid is 1/200 or more and 1/10 or less of a daily inflow amount of the water to be treated. 前記嫌気性処理工程で得られた処理水を濃縮して濃縮汚泥を得る濃縮工程をさらに有し、
前記濃縮汚泥を、前記供給管に移送して、前記液体として用いる請求項８〜１１のいずれか一項に記載の水処理方法。 Further comprising a concentration step of concentrating the treated water obtained in the anaerobic treatment step to obtain a concentrated sludge,
The water treatment method according to any one of claims 8 to 11 , wherein the concentrated sludge is transferred to the supply pipe and used as the liquid. 被処理水を上向流式で嫌気性反応槽に導入し、嫌気性汚泥と接触させることにより嫌気性処理する嫌気性処理工程と、
前記嫌気性反応槽内の被処理水の上部１／３の領域に設けられた撹拌板により、被処理水を撹拌する撹拌工程とを有する水処理方法であって、
前記嫌気性反応槽は処理水の流出部を有し、水面を前記流出部を含む部分と前記流出部を含まない部分とに分ける仕切り部材が設けられ、
前記嫌気性反応槽に保持された被処理水中に傾斜板が設けられ、
前記傾斜板は、上端が前記流出部を含まない部分またはその上方もしくは下方に位置し、下端が前記流出部を含む部分の下方に位置し、
前記撹拌板は、前記流出部を含まない部分の下方に設けられていることを特徴とする水処理方法。 An anaerobic treatment step in which the water to be treated is introduced into the anaerobic reaction tank in an upward flow manner and is subjected to anaerobic treatment by being brought into contact with anaerobic sludge;
A stirring plate provided in a region of the upper third of the water to be treated in the anaerobic reaction tank, and a stirring step of stirring the water to be treated ,
The anaerobic reaction tank has an outflow portion of the treated water, and a partition member for dividing a water surface into a portion including the outflow portion and a portion not including the outflow portion is provided,
An inclined plate is provided in the water to be treated held in the anaerobic reaction tank,
The inclined plate has an upper end positioned above or below the portion not including the outflow portion, and a lower end positioned below a portion including the outflow portion,
The water treatment method , wherein the stirring plate is provided below a portion not including the outflow portion . 前記嫌気性反応槽は、底部から水面までの高さが、前記嫌気性反応槽内の最大水平方向長さよりも短い請求項８〜１３のいずれか一項に記載の水処理方法。 The water treatment method according to any one of claims 8 to 13 , wherein the anaerobic reactor has a height from a bottom to a water surface shorter than a maximum horizontal length in the anaerobic reactor.
JP2017509866A 2015-03-27 2016-03-24 Water treatment device and water treatment method Active JP6640837B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2015067132 2015-03-27
JP2015067132 2015-03-27
PCT/JP2016/059411 WO2016158673A1 (en) 2015-03-27 2016-03-24 Water treatment apparatus and water treatment method

Publications (2)

Publication Number Publication Date
JPWO2016158673A1 JPWO2016158673A1 (en) 2018-01-25
JP6640837B2 true JP6640837B2 (en) 2020-02-05

Family

ID=57007103

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2017509866A Active JP6640837B2 (en) 2015-03-27 2016-03-24 Water treatment device and water treatment method

Country Status (3)

Country Link
JP (1) JP6640837B2 (en)
MY (1) MY182787A (en)
WO (1) WO2016158673A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7130537B2 (en) 2018-11-30 2022-09-05 住友重機械工業株式会社 Anaerobic treatment system
CN111908711A (en) * 2020-07-13 2020-11-10 中徽生态环境有限公司 Segmented biochemical mixed treatment water body ecological restoration method

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60168597A (en) * 1984-02-10 1985-09-02 Matsushita Electric Ind Co Ltd Methane fermentation apparatus
JPH02273598A (en) * 1989-04-14 1990-11-08 Taisei Corp Upward flow type anaerobic waste water treatment apparatus
JP2884971B2 (en) * 1992-12-17 1999-04-19 栗田工業株式会社 Anaerobic treatment method and apparatus
JPH07290088A (en) * 1994-04-26 1995-11-07 Mitsubishi Kakoki Kaisha Ltd Method for biologically denitrifying organic waste water
JPH0866694A (en) * 1994-08-29 1996-03-12 Hitachi Zosen Corp Methane fermentation method
JP4254125B2 (en) * 2002-04-24 2009-04-15 栗田工業株式会社 Anaerobic water treatment device
JP2005205327A (en) * 2004-01-23 2005-08-04 Kajima Corp Method and device for eliminating floating foreign matter in anaerobic digestion vessel
JP4982789B2 (en) * 2006-08-04 2012-07-25 独立行政法人国立環境研究所 Wastewater treatment method and apparatus by methane fermentation
JP6491406B2 (en) * 2012-07-27 2019-03-27 オルガノ株式会社 Anaerobic biological treatment method and anaerobic biological treatment apparatus

Also Published As

Publication number Publication date
WO2016158673A1 (en) 2016-10-06
MY182787A (en) 2021-02-05
JPWO2016158673A1 (en) 2018-01-25

Similar Documents

Publication Publication Date Title
EP2508483B1 (en) Waste water treatment equipment
US10814337B2 (en) Composite ozone flotation integrated device
JP4765022B2 (en) Solid-liquid separator
KR100808289B1 (en) Sedimentation of liquid waste treatment with screw type slant plant
CN103755098A (en) Complex oily wastewater treatment method and device
CN104817234A (en) System for treating high-concentration wire-drawing lubricant wastewater
KR100646042B1 (en) Sedimentation of liquid waste treatment with screw type slant plant
JP6640837B2 (en) Water treatment device and water treatment method
CN204508985U (en) A kind of thermo-chemical demulsification reactor
CN110386689A (en) Pretreatment system for bed mud residual water treatment equipment
CN106966490A (en) A kind of high-efficiency aerobic reactor and sewage treatment process
CN110407417A (en) A kind of Forebay of Pumping Station water quality efficient process integrated equipment
KR20050058308A (en) Secondary settling basin for biological wastewater treatment facilities
CN209442776U (en) A kind of secondary clarifier effluent canal and secondary settling tank and sewage disposal system
JP2012055837A (en) Anaerobic treatment apparatus and anaerobic treatment method
JP2019162592A (en) Treatment apparatus and treatment method of sludge-containing waste water, and water treatment system
CN111689602B (en) Fenton oxidation reaction device
CN209974593U (en) Cavitation air flotation equipment for sludge concentration
KR101232258B1 (en) Stirring apparatus and waste water treament system using the same
KR200384139Y1 (en) Sedimentation of liquid waste treatment with screw type slant plant
CN207581443U (en) Integrated coagulating sedimentation device
CN219709262U (en) Vertical flow sedimentation tank for collecting and treating floating sludge
CN108328774A (en) A kind of high efficient aeration sedimentation integrated device
CN212655650U (en) Petrochemical effluent disposal system
CN217757087U (en) Sewage treatment pool

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20181217

RD02 Notification of acceptance of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7422

Effective date: 20190301

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20190827

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20191023

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20191217

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20191226

R150 Certificate of patent or registration of utility model

Ref document number: 6640837

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150