JP4864258B2 - Organic wastewater treatment equipment - Google Patents

Description

【００３７】
表１で明らかなように、図７（Ｃ）に示すように固液分離部２２を有する本発明の酵母反応槽２０では、処理時間が２１．６時間で処理水のヘキサン抽出物質濃度が３０ｍｇ／ｌと低くなって、比較的短時間で十分に処理でき、酵母の有機物資化活性も良好に維持できた。
一方、従来の酵母反応槽２０Ａによる実験対照（Ａ）では、処理時間を２４時間としたが、処理水のヘキサン抽出物質濃度は６０ｍｇ／ｌと十分に分解除去できず、微生物菌体が流出する傾向を示した。
そこで、実験対照（Ｂ）のように従来の酵母反応槽２０Ａによる処理時間を３６時間としたところ、処理水のヘキサン抽出物質濃度は４０ｍｇ／ｌ程度まで低下したが、その処理（曝気）に長時間を要するので、槽内酵母の自己酸化現象が発現した。なお、このような酵母にとって適正な有機物負荷を逸脱した（低負荷）運転を繰り返すことにより、酵母に代わり、微生物が優占されてしまう結果となった。
【００３８】
実施例２．
図８は図７の従来（実験対照１，２）の酵母反応槽２０Ａおよび本発明の酵母反応槽２０の後段に酵母沈殿池４０をそれぞれ設置したものである。
すなわち、この実施例２は、各酵母反応槽２０Ａ，２０から流出する酵母処理水の水質を良好とすべく後段に酵母沈殿池４０を設置して実験を行ったものである。なお、各酵母反応槽２０Ａ，２０の運転条件は前記実施例１の場合と同じである。なお、本発明では、酵母沈殿池４０から酵母反応槽２０への汚泥返送は、固液分離槽２２で概ね酵母汚泥を分離し酵母反応槽２０に返送してしまうために行わなかった。
【００３９】
この実験による酵母反応槽２０Ａ，２０の流入水の流入部付近でのＯＲＰの測定結果を表２に示す。
【００４０】
【表２】

【００４１】
表２で明らかな通り、実験対照（Ａ），（Ｂ）では、ＯＲＰがマイナスを示し、酵母の処理活性が低下し、回復に時間やエネルギー（曝気時間）がかかった。
一方、本発明の酵母反応槽２０（Ｃ）はＯＲＰがプラスのままで酵母の処理活性を十分に維持でき、余分な活性回復のための動力も必要とせず、酵母処理も安定した。また、酵母反応槽２０内の酵母は常に好気条件下にあり、高（適正）負荷条件におかれているため、酵母増殖も活発であった。
【００４２】
次に、上記実験による生菌数の測定結果を表３に示す。なお、表３は運転開始２週間後のデータであり、表３中、○は酵母数を示し、×は細菌数を示す（酵母反応槽の混合液１ｍｌあたり）。
【００４３】
【表３】

【００４４】
表３で明らかな通り、本発明の酵母反応槽２０（Ｃ）では酵母が優占し、酵母の処理活性および繁殖を維持できたことにより酵母生菌数が多かった。
これに対して、実験対照（Ａ）と実験対照（Ｂ）とでは、運転経過に伴って酵母の生菌数に大きな差が生じ、酵母は解体現象や適正な負荷を逸脱した運転等で生存率が低下し、その生菌数が減少していた。
【００４５】
また、図８（Ｃ）に示す本発明の場合、酵母反応槽２０内の固液分離部２２で酵母汚泥が分離されるので、後段の酵母沈殿池４０へのＳＳ負荷が大幅に軽減される。このため、酵母沈殿池４０を設ける場合には、その容積や設置面積を小さくでき、処理水質（ＳＳ濃度）も良好にすることができる。
【００４６】
ここで、従来の酵母処理では、ＭＬＳＳ濃度程度１０，０００ｍｇ／ｌ程度の運転を行うため、沈殿槽（酵母沈殿池）の水面積負荷（Ｑ／Ａ）は１０ｍ^３／ｍ２・日以下とする必要があった。また、沈殿槽での滞留時間（ＨＲＴ）は３時間程度であれば良かった。しかし、沈殿槽の直部の水深（Ｈ）が２．５ｍ以上は必要であるため、沈殿槽の実質の滞留時間（ＨＲＴ）は６時間程度となっていた。なお、この滞留時間（ＨＲＴ）は式（１）〜（６）で求めることができる。
Ｑ／Ａ＜＝１０ ・・・・・（１）
Ｖ＝ＡＨ ・・・・・（２）
Ｈ≧２．５ ・・・・・（３）
（Ｈ＝２．５とした場合）
（２）式より
Ａ＝Ｖ／２．５ ・・・・・（４）
（４）式を（１）式に代入して
Ｑ／（Ｖ／２．５）＜＝１０・・・（５）
（５）式より
Ｖ／Ｑ×２４＞＝６（ＨＲＴ） （６）
ここで、
Ｑ：流入水量（ｍ^３／日）
Ａ：沈殿槽水面積（ｍ^２）
Ｈ：沈殿槽水深（ｍ）
【００４７】
この発明によれば、沈殿槽へ移流する混合液のＭＬＳＳ濃度を３，０００〜５，０００ｍｇ／ｌ程度に軽減できる。この程度のＭＬＳＳ濃度であれば、沈殿槽の水面積負荷は２０ｍ^３／ｍ^２・日以下とすれば良い。したがって、沈殿槽の実質の滞留時間（ＨＲＴ）は、上記式（５）より３時間となって、短時間で良好に固液分離できることがわかる。
【００４８】
実施例３．
図９（Ａ），（Ｂ）は図８（Ａ），（Ｂ）に示す実験対照１，２の酵母沈殿池４０の後段に活性汚泥槽４２と沈殿池４３を設置し、図９（Ｃ）は本発明の酵母反応槽２０の後段に活性汚泥槽４２と沈殿池４３を設置したものである。なお、本発明の酵母反応槽２０は槽内に固液分離２２を有しているため、図９（Ｃ）の酵母沈殿池４０は不要とした。
そして、図９に示す実験対照（Ａ），（Ｂ）および本発明の設備（Ｃ）を処理の河川放流を目的とした施設に適用して処理性能を調べた。その結果として放流水（処理水）のＳＳ濃度を表４に示す。
【００４９】
【表４】

【００５０】
表４において、実験対照（Ａ），（Ｂ）では、油を含んだ酵母汚泥が酵母沈殿池４０から後段の活性汚泥槽４２に流出することはなかったが、投入有機物の殆どが多大なエネルギーが投入されている酵母反応槽２０Ａおよび酵母沈殿池４０で除去されてしまうため、低負荷運転となった活性汚泥槽４２内では活性汚泥フロックが解体傾向となった。
【００５１】
これに対して本発明の場合、
▲１▼酵母反応槽２０では油脂等の酸化に時間がかかる有機物を速やかに吸着除去し、適正な運転条件の下で確実に酸化分解する。
▲２▼固液分離槽２２では未酸化の有機物を貯蔵する酵母（汚泥）等が確実に沈降分離し、酵母の活性を低下させないように沈殿した酵母を速やかに酵母反応槽に返送する。
▲３▼後段の活性汚泥槽４２では、油脂等の酸化に時間がかかる有機物や未酸化の有機物を貯蔵する酵母（汚泥）が除去され、易分解性の有機物が残存する酵母沈殿池４０からの流出水を導入し、適正な運転条件の下で確実に活性汚泥処理する。
というように、それぞれの槽がそれぞれ役割を担い、確実で適正に処理が行われるため、実験対照（Ａ），（Ｂ）などで起きる問題は発生せず、さらに解体現象を起こすなどのエネルギーの不要な消費を防止でき、安定した効率のよい生物学的水処理ができる。
【００５２】
また、本発明の酵母反応槽２０では、一定量以上の酵母汚泥は保持できない（キャリーオーバーなど）ため、槽内のＭＬＳＳ濃度が極端に高くなることはなく、これにより概ね常時適切な汚泥負荷条件で運転することができ、解体現象等の発生を防止できる。なお、キャリーオーバーし本発明の装置から流出する酵母汚泥は、活性汚泥の栄養分（資化可能な有機物）として利用できるため、低負荷時など適宜活性汚泥槽に投入することで活性汚泥槽を適切な負荷条件で運転することができる。
【００５３】
さらに、本発明において、流入水濃度が増えてＭＬＳＳ濃度を増加させる必要があるときに酵母反応槽２０内に酵母を保持させる固定化手段として担体を投入したところ、酵母の流出量が減って良好であった。
【００５４】
以上、本発明の酵母反応槽２０は、油を含有しているが全体的に有機物負荷としてそれほど多くない施設や、油脂のように分解時間がかかる有機物と易分解性の有機物のように成分によっては分解時間に差がある廃水処理に好適であった。
【００５５】
【発明の効果】
以上のように、本発明によれば、散気手段を有し、好気状態で廃水中の有機物を酸化分解する有機物資化性酵母を含む微生物群により難分解性有機物質の油脂を含む廃水を好気的に生物学的処理する酵母反応槽および該酵母反応槽の流出端側に水面開口部が設けられた仕切部材で前記酵母反応槽と一体に区画形成され、前記水面開口部より流入する前記有機物資化性酵母を含む酵母反応槽混合液を酵母汚泥と処理水とに固液分離する沈殿分離槽からなる有機性廃水処理装置において、前記沈殿分離槽内に設けられ、前記仕切部材との間に移流してくる酵母反応槽混合液の下向流路を形成し、前記沈殿分離槽内が撹拌されるのを防止するバッフルと、前記沈殿分離槽内の底部に設けられ、前記仕切部材側が傾斜下降端となる沈降汚泥ガイド部と、前記仕切部材の下端に設けられ、前記沈殿分離槽で沈降する酵母汚泥を前記沈降汚泥ガイド部の傾斜に沿って酵母反応槽に直接移流させる開口部とを備える構成としたので、酵母反応槽内にて酵母に吸着された難分解性の有機物である油脂等のヘキサン抽出物質が槽内で酸化されて流出しそうになっても、そのヘキサン抽出物質を含む有機物は、前記酵母反応槽に一体化した固液分離槽に移流して沈殿し速やかに酵母反応槽に返送させることができる。このため、油脂等のヘキサン抽出物質を含む有機物が後段設備に流出するのを極力抑えると共に、後段の活性汚泥槽を設けた場合には易分解性の有機物の酸化・分解を担わせることができる。
【００５６】
また、上述のように、酵母反応槽の固液分離部で沈殿した酵母汚泥は、好気状態の酵母反応槽に速やかに返送されるため、従来の酵母処理の場合に比して嫌気状態に晒される時間が非常に短縮される。これにより、酵母の活性が低下しないため、有機性廃水の生物学的所定を常に安定して効率よく行うことができ、従来のように酵母活性を回復させるためのエネルギー（曝気・撹拌等）投入を大幅に削減できてコスト低減を図ることができる。
【００５７】
さらに、酵母反応槽では常に酵母が優先的に同じ有機物（酸化分解され難い油脂等のヘキサン抽出物質等）を吸着するため、酵母の分解活性（馴化）が高くなり、分解効率が上昇すると共に、曝気によって微生物から分泌された菌体外酸素も槽内に濃縮されるため、さらに酸化分解効率を上昇させることが期待できるなど、酵母処理活性、能力を最大限に引き出すことができる。
【００５８】
また、本発明の装置の後段に沈殿池を設ける場合、固液分離槽から排出される処理水の酵母濃度が従来の酵母反応槽と比較して飛躍的に低くなるため、沈殿池容積を小さくでき、これにより敷地面積，建設コストの低減を図ることができる。また、概ね常時酵母を好気状態に維持でき、酵母の活性を良好に維持できる。このように、酵母を良好な状態に維持できるため、沈降性がよく、酵母反応槽のＳＳ濃度を高く維持でき、より流入負荷を増大させて処理することができる。
【００５９】
加えて、本発明の装置に活性汚泥槽などの二次処理設備を設ける場合には、酵母反応槽で油脂等の酸化に時間がかかる有機物を速やかに吸着除去し、固液分離槽で未酸化の有機物を貯蔵する酵母（汚泥）等を確実に沈降分離し、活性汚泥槽で固液分離槽流出水に含まれる易分解性の有機物を酸化分解するため、安定して良好な処理水を得ることができる。
【図面の簡単な説明】
【図１】 この発明の実施の形態１による有機性廃水処理装置を示すフローシートである。
【図２】 この発明の実施の形態２による有機性廃水処理装置を示すフローシートである。
【図３】 この発明の実施の形態３による有機性廃水処理装置を示すフローシートである。
【図４】 この発明の実施の形態４による有機性廃水処理装置を示すフローシートである。
【図５】 この発明の実施の形態５による有機性廃水処理装置を示すフローシートである。
【図６】 この発明の実施の形態６による有機性廃水処理装置を示すフローシートである。
【図７】 実験に用いた酵母反応槽のフローシートである。
【図８】 他の実験に用いた有機性廃水処理装置のフローシートである。
【図９】 別の実験に用いた有機性廃水処理装置のフローシートである。
【図１０】 従来の有機性廃水処理装置を示すフローシートである。
【符号の説明】
２０ 酵母反応槽
２１ 仕切部材
２１ａ 水面開口部
２２ 固液分離槽
２３ バッフル
２４ 沈降汚泥ガイド部
２５ 汚泥滞留部
２６ 膜分離装置
３０ 流入水管路
３１ 散気装置（散気手段）
３２ ブロワ
３３ 汚泥返送管（汚泥返送手段）
３４ ポンプ（汚泥返送手段）
３５ 開口部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic wastewater treatment apparatus for biologically treating organic wastewater with microorganisms containing organic substance-assimilating yeast.
[0002]
[Prior art]
FIG. 10 is a flow sheet showing a conventional organic wastewater treatment apparatus.
In the figure, 1 is a yeast reaction tank in which wastewater containing pollutants (BOD, SS, oil, etc.) is biologically treated with yeast under aerobic conditions, and 2 is an aeration arranged at the inner bottom of the yeast reaction tank 1 An aeration device for agitation, and an aeration blower 4 is connected to the aeration device 2 via a vent line 3.
[0003]
Reference numeral 5 denotes a flow rate adjusting tank that stores inflow wastewater and adjusts the amount of wastewater flowing into the yeast reaction tank 1. A raw water pump 7 for sending waste water to the yeast reaction tank 1 through a raw water pipe 6 is disposed at the inner bottom of the inflow adjusting tank 5.
[0004]
8 is a gravity precipitation tank (also referred to as gravity precipitation tank) that receives a mixed liquid of waste water and yeast sludge in the yeast reaction tank 1 from the pipe 9 and separates it into treated water and yeast sludge. A sludge scraping machine for scraping the precipitated yeast sludge in the tank 8; 11 a sludge return pipe for returning a part of the sludge (yeast) precipitated at the bottom of the settling tank 8 into the yeast reaction tank 1 by the pump 12; Reference numeral 13 denotes a sludge extraction pipe for extracting a part of sludge (yeast) precipitated at the bottom of the settling tank 8 as surplus yeast by the pump 14.
[0005]
Next, the operation will be described.
The waste water 15 is first stored in the flow rate adjusting tank 5 and then introduced into the yeast reaction tank 1 as raw water to be treated by the raw water pump 7. In this yeast reaction tank 1, the influent wastewater and the yeast sludge returned from the sedimentation tank 8 through the sludge return pipe 11 are contacted and mixed, and sludge is produced by yeast under aerobic conditions by aeration from the air diffuser 2. Wastewater containing substances is treated.
[0006]
After such biological treatment in the yeast reaction tank 1, the mixed solution in the yeast reaction tank 1 is transferred to the sedimentation tank 8 through the conduit 9, and solidified into the treated water 16 and the yeast sludge by gravity. Liquid separation. The treated water 16 is discharged or sent to a further processing step at a later stage, and a part of the precipitated sludge is returned to the yeast reaction tank 1 through the sludge return pipe 11 by the pump 12, and the remainder of the precipitated sludge is the excess sludge. As a result, the pump 14 sends it to the subsequent sludge treatment process via the sludge extraction pipe 13 and processes it.
[0007]
[Problems to be solved by the invention]
Since the conventional organic wastewater treatment apparatus is configured as described above, there are various problems as described below.
In the normal activated sludge method, organic substances are adsorbed and oxidatively decomposed mainly by the action of bacteria and the like. Therefore, the amount of organic load necessary for the tank design is determined by BOD5. On the other hand, in yeast treatment using yeast capable of decomposing more organic matter than bacteria, the amount of organic matter actually adsorbed and oxidatively decomposed in the tank does not match with the amount of organic matter loaded by BOD5. It was designed by measuring and determining the organic load.
[0008]
However, CODcr indicates the oxygen concentration consumed during the oxidation of organic substances that can be decomposed by strong oxidants, and BOD20 indicates the oxygen concentration necessary for the decomposition of organic substances that can be decomposed by bacteria over 20 days. It only shows the amount of oxygen consumed when the total amount of the input organic matter was oxidatively decomposed.
However, in actual organic substances, there are organic substances that decompose in a few hours to organic substances that take days to decompose. In the biological treatment using yeast-containing microorganisms for the current organic wastewater, the organic matter components are not taken into consideration, and the oils and fats that take time to decompose, considering first whether the emission regulations can be cleared The time when the hardly decomposable substance is decomposed is reflected in the design.
For this reason, microorganisms such as yeast that adsorb organic substances that are decomposed in a short time, such as carbohydrate monosaccharides, do not have enough organic substances to obtain sufficient energy in the input organic substances, so auto-oxidation (disassembly phenomenon) There was a problem of doing it.
In other words, if it deviates from the range of organic load that is preferable for yeast, and as a result, microorganisms suitable for low load dominate and become high inflow, such as inflow of fats and oils, etc. Since it was not dominant, there was a problem that stable and efficient biological treatment would be hindered.
In addition, the discharge of treated water exceeds the drainage regulation value due to the outflow of organic substances that cannot be adsorbed by yeast, etc. Or organic matter negatively Load The problem of increasing results Ah It was.
[0009]
Here, yeast, which is an aerobic microorganism, efficiently oxidizes and decomposes organic matter in an aerobic state in which oxygen molecules are present (ORP +). However, when exposed to anaerobic or anaerobic conditions (ORP-) in which oxygen molecules do not exist in a sedimentation basin or the like, energy cannot be obtained without being able to oxidatively decompose organic matter, so that the activity decreases, and in some cases it is active May stop. Therefore, even if it is returned to the yeast reaction tank and becomes aerobic, it takes time to recover the activity capable of oxidatively degrading organic matter, which not only inhibits biological treatment but also restores the activity. In addition, there is a problem that more energy needs to be input.
[0010]
The present invention has been made to solve the above-described problems, and hexane-extracted substances such as fats and oils, which are organic substances that are difficult to be oxidatively decomposed, contained in wastewater are lipophilic and hardly adsorbed to yeast. Utilizing the property of being easy, the hexane extract can be efficiently adsorbed to the organic substance-assimilating yeast, and the yeast that has adsorbed the hexane extract does not flow out of the system. An object of the present invention is to obtain an organic wastewater treatment apparatus capable of performing good biological treatment.
[0011]
In addition, the present invention can quickly separate and collect yeast sludge and can return the yeast sludge to the yeast reaction tank in a much shorter time than conventional yeast treatment equipment. ) An object of the present invention is to obtain an organic wastewater treatment apparatus that can maintain its activity satisfactorily.
[0012]
Furthermore, the present invention provides time and energy for recovering the activity of yeast whose activity has been reduced or stopped. Decline An object of the present invention is to obtain an organic wastewater treatment apparatus that can significantly reduce the amount of wastewater.
[0013]
Furthermore, this invention can maintain the organic substance utilization (decomposition) activity of yeast satisfactorily, whereby the processing ability of the yeast can be maximized, and stable and efficient yeast treatment can be performed. The purpose is to obtain an organic wastewater treatment device.
[0014]
[Means for Solving the Problems]
The organic wastewater treatment apparatus according to the present invention has aeration means, Oxidative decomposition of organic matter in wastewater in aerobic condition By microorganism group including organic substance assimilation yeast Contains fats and oils of persistent organic substances Yeast reaction for aerobic biological treatment of wastewater Tank and the A partition member provided with a water surface opening on the outflow end side of the yeast reaction tank is partitioned and formed integrally with the yeast reaction tank, and flows from the water surface opening. Above Precipitation separation tank for solid-liquid separation of yeast reaction tank mixture containing organic substance-utilizing yeast into yeast sludge and treated water In the organic wastewater treatment apparatus comprising: a downward flow path of the yeast reaction tank mixed solution that is provided in the precipitation separation tank and is transferred to and from the partition member; and the inside of the precipitation separation tank is agitated A baffle for preventing the sedimentation, and a sedimentation sludge guide portion provided at the bottom of the sedimentation separation tank, the partition member side being an inclined lower end, The precipitation separation tank provided at the lower end of the partition member Settle at Yeast sludge Along the slope of the sedimentation sludge guide part And an opening to be directly transferred to the yeast reaction tank.
[0015]
Organic wastewater treatment equipment according to this invention Is , A yeast reaction tank having aeration means for aerobically biologically treating wastewater with a group of microorganisms containing organic substance-assimilating yeast, and a partition provided with a water surface opening on the outflow end side of the yeast reaction tank A precipitation separation tank for solid-liquid separation of the yeast reaction tank mixed liquid flowing in from the water surface opening into solid and liquid, and a yeast sludge in the precipitation separation tank. With sludge return pipe to return to yeast reaction tank Is.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below.
Embodiment 1 FIG.
FIG. 1 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 1 of the present invention.
In FIG. 1, 20 is a yeast reaction tank for biologically treating organic wastewater with microorganisms containing organic substance-assimilating yeast, 30 is an inflow water conduit for introducing organic wastewater into the yeast reaction tank 20, and 31 is An aeration and stirring aeration device (aeration means) disposed on the bottom side of the yeast reaction tank 20, and an air supply blower 32 is connected to the aeration device 31.
[0018]
21 is a partition member provided in the yeast reaction tank 20, and by this partition member 21, a solid-liquid separation tank (solid-liquid separation means) 22 is integrally formed on the outflow end side in the yeast reaction tank 20. Has been. Therefore, the yeast reaction tank 20 has a single tank structure integrally including the solid-liquid separation tank 22. In addition, in order to maintain the activity of the yeast, it is desirable that the apparatus according to the present invention has a single tank configuration, but it may be configured by two adjacent tanks, and in this case, the same effect can be obtained. .
[0019]
21 a is a water surface opening provided in the partition member 21, and serves as an advection port for advancing the mixed liquid in the yeast reaction tank 20 to the solid-liquid separation tank 22. Reference numeral 23 denotes a baffle disposed on the partition member 21 side in the solid-liquid separation tank 22. The baffle 23 forms a downward flow path of the mixed liquid that is transferred from the water surface opening 21 a to the solid-liquid separation tank 22 with the partition member 21, and the newly mixed liquid is transferred to the baffle 23. Solid-liquid separation tank The inside of 22 is prevented from being stirred.
[0020]
Reference numeral 24 denotes a sedimentation sludge guide portion provided at the bottom of the solid-liquid separation tank 22, and this sedimentation sludge guide portion 24 is connected to the partition member 21 and is composed of an inclined guide whose connection side is the highest. Reference numeral 25 denotes a pit-shaped sludge retention part formed on the inclined descending end side of the sedimentation sludge guide part 24 at the bottom of the solid-liquid separation tank 22, and 33 denotes the sedimentation sludge (yeast) of the sludge retention part 25 by the pump 34. This is a sludge return pipe (sludge return means) that returns to the yeast reaction tank 20. In addition, the sedimentation sludge guide part 24 may be a both-side inclined shape (hopper shape) in addition to the one-side inclined shape, and may be any shape as long as the sludge (yeast) that settles easily collects.
[0021]
Next, the operation will be described.
The organic wastewater that has flowed into the yeast reaction tank 20 from the inflow water conduit 30 is sufficiently mixed with the liquid mixture in the yeast reaction tank 20 by the aeration from the aeration device 31, so that Biologically treated (yeast treated) under aerobic conditions by the containing microorganisms. In addition, the organic substance-assimilating yeast used in the present invention is different from the yeast that is fermented in an oxygen-free state used in the field of food such as brewing and the pharmaceutical field, such as Candida, Trichosporon, Trichospoera, and Saccharomyces. It belongs to fungi and is a yeast having a function of assimilating organic substances (oxidizing and decomposing organic substances in wastewater) in an aerobic state. For this reason, the activity of organic substance-assimilating yeast having no or a slight fermentation function is reduced in anoxic or anaerobic conditions, and in some cases, the activity is stopped.
[0022]
Therefore, in the yeast reaction tank 20 that is in an aerobic state due to the air diffused from the air diffuser 31, the organic substance assimilating yeast is an organic substance in the wastewater, especially an organic substance that takes time to oxidatively decompose (refractory). Adsorb and remove hexane extract substances such as oils and fats. That is, hexane extract substances such as fats and oils are lipophilic and difficult to dissolve in wastewater, but are easily adsorbed by yeast. Using this characteristic, in the yeast reaction tank 20, first, the hexane extract is adsorbed on the yeast, and the yeast that has adsorbed the hexane extract actively oxidatively decomposes the hexane extract under an aerobic condition.
[0023]
Then, the mixed liquid sufficiently stirred and mixed in the yeast reaction tank 20 is transferred to the solid-liquid separation tank 22 from the water surface opening 21 a above the partition member 21. Since the mixed liquid transferred into the solid-liquid separation tank 22 is flowed downward by the baffle 23, the solid-liquid separation tank 22 is prevented from being disturbed, and air diffused in the yeast reaction tank 20 or the like. Is hardly affected by stirring. For this reason, the liquid mixture transferred to the solid-liquid separation tank 22 is efficiently solid-liquid separated into sludge (yeast) and treated water. The separated sludge settles in the staying portion 25 along the inclination of the settling sludge guide portion 24. The sludge settled in the staying portion 25 is returned to the yeast reaction tank 20 through the sludge return pipe 33 by the operation of the pump 34. On the other hand, the separated treated water is discharged out of the system.
[0024]
According to Embodiment 1 demonstrated above, in the yeast reaction tank 20 which has the aeration apparatus 31, and biologically processes inflow wastewater by a microorganism containing an organic substance utilization yeast under aerobic conditions, The yeast reaction tank 20 and the solid-liquid separation tank 22 are formed by integrally partitioning the solid-liquid separation tank 22 that receives the mixed liquid from the yeast reaction tank and separates it into sludge and treated water by the partition member 21. Because it has a single tank configuration, yeast sludge adsorbing hexane extractants such as fats and oils that can become a pollution load in the latter stage (secondary treatment equipment, precipitation equipment, discharge equipment, etc.) is prevented from flowing out of the system as much as possible. 20 has an effect that the hexane extractant can be sufficiently decomposed. In addition, the organic substance etc. which are easy to be decomposed | disassembled by oxidation contained in waste water can be decomposed | disassembled and removed comparatively easily with a secondary treatment facility of a latter stage as needed.
[0025]
Moreover, by integrating the yeast reaction tank 20 and the solid-liquid separation tank 22, the yeast sludge can be quickly separated and recovered, and the yeast sludge can be transformed into yeast in a significantly shorter time than conventional yeast treatment equipment. It can be returned to the reaction vessel 20. This prevents yeast sludge from being exposed to anaerobic or anaerobic conditions in which there are no oxygen molecules that reduce or stop yeast activity, as in conventional yeast sedimentation basins, and maintains yeast activity well. Can do.
[0026]
In addition, the time and energy consumption for recovering the activity of the yeast whose activity has been reduced or stopped can be significantly reduced, and the yeast activity can be maintained well (no stress is applied), so that the processing capacity of the yeast is maximized. The yeast treatment can be performed stably and efficiently.
[0027]
Embodiment 2. FIG.
FIG. 2 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 2 of the present invention. The same parts as those in FIG.
In this Embodiment 2, while arrange | positioning the sedimentation sludge guide part 24 in the solid-liquid separation tank 22 in the direction opposite to the case of the said Embodiment 1 so that the inclination descent | fall end may become the partition member 21 side, At the lower end of the partition member 21, an opening 35 for advancing sedimentation sludge corresponding to the inclined descending end of the sedimentation sludge guide portion 24 is provided. In addition, as long as the sludge in the solid-liquid separation tank 22 is returned to the yeast reaction tank 20, the opening part 35 may have any shape and installation position.
[0028]
According to the second embodiment configured as described above, the settled sludge obtained as a result of the solid-liquid separation in the solid-liquid separation unit 22 is passed from the opening 35 at the lower end of the partition member 21 along the inclination of the sedimentation sludge guide unit 24. It can be directly transferred into the yeast reaction tank 20. For this reason, even if it does not operate the pump 34 for sludge return, the sedimentation sludge in the solid-liquid separation part 22 can be rapidly returned naturally in the yeast reaction tank 20, and the activity of yeast can be maintained favorable. Moreover, if the said pump 34 is operated, the sedimentation sludge in the solid-liquid separation part 22 can be transferred to the inflow end side of the yeast reaction tank 20 more rapidly.
[0029]
Embodiment 3 FIG.
FIG. 3 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 3 of the present invention. The same parts as those in FIG.
In the third embodiment, the sludge return facility (sludge return pipe 33 and pump 34) in the second embodiment is eliminated. That is, as described in the second embodiment, the settled sludge in the solid-liquid separation unit 22 is directly transferred from the opening 35 into the yeast reaction tank 20 along the inclination of the settled sludge guide unit 24. As a result, the sludge return means can be eliminated, the overall configuration can be simplified, and the equipment cost can be reduced.
[0030]
Embodiment 4 FIG.
FIG. 4 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 4 of the present invention. The same parts as those in FIG.
In the fourth embodiment, the water surface opening 21a and the baffle 23 in the second embodiment (FIG. 2) are eliminated.
In the case of this Embodiment 4, the organic waste water which flowed in the yeast reaction tank 20 is mixed with the liquid mixture in the yeast reaction tank 20, and the liquid mixture is transferred to the outflow end side of the yeast reaction tank 20 and opened. The liquid is transferred from the portion 35 into the solid-liquid separation tank 22. Since the solid-liquid separation tank 22 is not affected by aeration in the yeast reaction tank 20, solid-liquid separation is performed. As a result of the solid-liquid separation, the sludge that settles is transferred into the yeast reaction tank 20 from the bottom opening 21b along the inclination of the sedimentation sludge guide portion 24. In addition, when the sludge settled in the solid-liquid separation tank 22 is positively transferred into the yeast reaction tank 20, the pump 34 may be operated.
[0031]
Embodiment 5 FIG.
FIG. 5 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 5 of the present invention. The same parts as those in FIG.
In the fifth embodiment, the sludge return equipment (sludge return pipe 33 and pump 34) in the fourth embodiment is not required, the configuration of the entire apparatus is further simplified, and the equipment cost is reduced. Can do.
[0032]
Embodiment 6 FIG.
FIG. 6 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 6 of the present invention. The same parts as those in FIG.
In the sixth embodiment, the baffle 23 in the first embodiment is not necessary, and a membrane separation device 26 is installed in the solid-liquid separation unit 22.
In the case of the sixth embodiment, in the solid-liquid separation tank 22, the liquid mixture transferred from the water surface opening 21a is solid-liquid separated by the membrane separation device 26, and as a result of the solid-liquid separation, the membrane by the membrane separation device is obtained. The filtered water is discharged out of the system as treated water. Moreover, since the sludge is concentrated (highly concentrated) in the solid-liquid separation tank 22 by solid-liquid separation, the sludge is appropriately transferred into the yeast reaction tank 20 by the sludge return facilities 33 and 34. In addition, since sludge is gradually stored / concentrated in the yeast reaction tank 20, it is appropriately extracted out of the system.
[0033]
In addition, in this Embodiment 6, although the example which installed the membrane separation apparatus 26 in the solid-liquid separation tank 22 was shown, the tank shape and a sludge return means are arbitrary, and the point can prevent the residence of yeast sludge, The structure is not limited to this as long as the inflow from the yeast reaction tank 20 can be secured.
[0034]
Example 1.
Next, a description will be given of the results of experiments conducted by introducing a microbial community containing yeast cultured under the same conditions in the conventional and the yeast reaction tank of the present invention.
7 (A) and 7 (B) show a conventional yeast reaction tank 20A used in the experiment, and this yeast reaction tank 20A has an aeration device 31 installed at the bottom of the tank with the entire area inside the tank as the yeast treatment area. It is only a structure and does not have a solid-liquid separation part.
Here, the yeast reaction tank 20A in FIG. 7A is used as Experiment Control 1 with the residence time of the mixed solution being 24 hours, and FIG. 7B is a yeast reaction tank 20A having the same volume and structure as FIG. 7A. The mixed liquid residence time was 36 hours, and this was used as Experimental Control 2.
FIG. 7C shows the yeast reaction tank 20 of the present invention, which has a solid-liquid separation part 22 in a tank having the same volume as the conventional yeast reaction tank 20A of FIGS. 7A and 7B. .
The volume of the yeast reaction tank 20A of Experiment Controls 1 and 2 is 20L. In the yeast reaction tank 20 of the present invention, the aeration part volume is 18L and the residence time is 21.6 hours, and the sedimentation part volume is 2L and the residence time is 2.4 hours. It was.
[0035]
In the above, the inflow water of each yeast reaction tank 20A, 20 employs the wastewater of the cream-type food manufacturing factory, and experiments were conducted by introducing a group of microorganisms containing yeast cultured under the same conditions in each tank on a 20 L bench scale scale. As a result, the quality of the influent water which is the treated water is 5140 mg / l for CODcr, 1040 mg / l for hexane extractable substance, BOD ₅ The concentration was 2440 mg / l.
Moreover, when the hexane extract substance density | concentration of the mixed-solution supernatant water (treated water) which flows out from each tank was measured, it became the result shown in Table 1.
[0036]
[Table 1]

[0037]
As is apparent from Table 1, in the yeast reaction tank 20 of the present invention having the solid-liquid separation part 22 as shown in FIG. 7C, the treatment time is 21.6 hours and the hexane extract substance concentration of the treated water is 30 mg. It was as low as / l, and it was possible to sufficiently treat in a relatively short time, and the organic substance assimilation activity of yeast could be maintained well.
On the other hand, in the experimental control (A) using the conventional yeast reaction tank 20A, the treatment time was set to 24 hours, but the hexane extract substance concentration of the treated water was not sufficiently decomposed and removed at 60 mg / l, and the microbial cells flowed out. Showed a trend.
Therefore, when the treatment time in the conventional yeast reaction tank 20A was set to 36 hours as in the experimental control (B), the concentration of the hexane extractant in the treated water was reduced to about 40 mg / l, but this treatment (aeration) was long. Since time was required, the autooxidation phenomenon of the yeast in the tank occurred. In addition, by repeating the driving | operation which deviated from organic substance load appropriate for such yeast (low load), it resulted in microorganisms predominating instead of yeast.
[0038]
Example 2
FIG. 8 shows a conventional yeast reaction tank 20A of FIG. 7 (Year Reaction Tanks 1 and 2) and a yeast sedimentation basin 40 installed in the subsequent stage of the yeast reaction tank 20 of the present invention.
That is, Example 2 is an experiment in which a yeast sedimentation basin 40 is installed in the subsequent stage in order to improve the quality of the yeast treated water flowing out from each yeast reaction tank 20A, 20. In addition, the operating conditions of each yeast reaction tank 20A, 20 are the same as in the case of Example 1. In the present invention, the sludge return from the yeast sedimentation basin 40 to the yeast reaction tank 20 is not performed because the yeast sludge is generally separated in the solid-liquid separation tank 22 and returned to the yeast reaction tank 20.
[0039]
Table 2 shows the ORP measurement results in the vicinity of the inflow portion of the inflow water in the yeast reaction tanks 20A and 20 by this experiment.
[0040]
[Table 2]

[0041]
As is apparent from Table 2, in the experimental controls (A) and (B), ORP showed a minus value, the processing activity of the yeast decreased, and recovery took time and energy (aeration time).
On the other hand, the yeast reaction tank 20 (C) of the present invention was able to sufficiently maintain the processing activity of the yeast while maintaining the positive ORP, did not require any extra power to recover the activity, and stabilized the yeast processing. Moreover, since the yeast in the yeast reaction tank 20 was always under an aerobic condition and placed under a high (appropriate) load condition, yeast growth was also active.
[0042]
Next, Table 3 shows the measurement results of the viable cell count by the above experiment. Table 3 shows data 2 weeks after the start of operation. In Table 3, ○ indicates the number of yeasts, and × indicates the number of bacteria (per 1 ml of the mixture in the yeast reaction tank).
[0043]
[Table 3]

[0044]
As is apparent from Table 3, in the yeast reaction tank 20 (C) of the present invention, yeast predominated, and the number of viable yeast was large due to the ability to maintain the processing activity and breeding of the yeast.
On the other hand, in the experimental control (A) and the experimental control (B), there is a large difference in the number of viable yeast as the operation progresses, and the yeast survives in the operation that deviates from the demolition phenomenon or the appropriate load. The rate decreased and the number of viable bacteria decreased.
[0045]
In the case of the present invention shown in FIG. 8C, since the yeast sludge is separated by the solid-liquid separation unit 22 in the yeast reaction tank 20, the SS load on the subsequent yeast sedimentation basin 40 is greatly reduced. . For this reason, when providing the yeast sedimentation basin 40, the volume and installation area can be made small, and the quality of treated water (SS density | concentration) can also be made favorable.
[0046]
Here, in the conventional yeast treatment, since the MLSS concentration is about 10,000 mg / l, the water area load (Q / A) of the settling tank (yeast settling tank) is 10 m. ³ / M2 / day or less. The residence time (HRT) in the settling tank should be about 3 hours. However, since the water depth (H) in the direct part of the settling tank is required to be 2.5 m or more, the substantial residence time (HRT) of the settling tank is about 6 hours. In addition, this residence time (HRT) can be calculated | required by Formula (1)-(6).
Q / A <= 10 (1)
V = AH (2)
H ≧ 2.5 (3)
(When H = 2.5)
From equation (2)
A = V / 2.5 (4)
Substituting equation (4) into equation (1)
Q / (V / 2.5) <= 10 (5)
From equation (5)
V / Q × 24> = 6 (HRT) (6)
here,
Q: Inflow water volume (m ³ /Day)
A: Precipitation tank water area (m ² )
H: Deposition tank water depth (m)
[0047]
According to this invention, the MLSS concentration of the liquid mixture that is transferred to the precipitation tank can be reduced to about 3,000 to 5,000 mg / l. With this level of MLSS concentration, the water area load of the settling tank is 20 m. ³ / M ² ・ It should be less than a day. Therefore, the substantial residence time (HRT) of the settling tank is 3 hours from the above formula (5), and it can be seen that solid-liquid separation can be satisfactorily performed in a short time.
[0048]
Example 3
9 (A) and 9 (B), an activated sludge tank 42 and a sedimentation basin 43 are installed after the yeast sedimentation basin 40 of the experimental controls 1 and 2 shown in FIGS. 8 (A) and 8 (B). ) Is a system in which an activated sludge tank 42 and a sedimentation basin 43 are installed after the yeast reaction tank 20 of the present invention. In addition, since the yeast reaction tank 20 of this invention has the solid-liquid separation 22 in the tank, the yeast sedimentation basin 40 of FIG.9 (C) was made unnecessary.
Then, the experimental controls (A) and (B) shown in FIG. 9 and the facility (C) of the present invention were applied to a facility for the purpose of river discharge of treatment, and the treatment performance was examined. As a result, the SS concentration of the discharged water (treated water) is shown in Table 4.
[0049]
[Table 4]

[0050]
In Table 4, in the experimental controls (A) and (B), the yeast sludge containing oil did not flow out from the yeast sedimentation basin 40 to the activated sludge tank 42 in the subsequent stage, but most of the input organic matter has a great deal of energy. Is removed in the yeast reaction tank 20A and the yeast sedimentation basin 40 into which the activated sludge flocs have been disposed, and the activated sludge flocs tend to be dismantled in the activated sludge tank 42 which has been operated at a low load.
[0051]
In contrast, in the present invention,
(1) The yeast reaction tank 20 quickly adsorbs and removes organic substances that take time to oxidize, such as fats and oils, and reliably oxidatively decomposes them under appropriate operating conditions.
{Circle around (2)} In the solid-liquid separation tank 22, yeast (sludge) or the like storing unoxidized organic matter is surely settled and separated, and the precipitated yeast is promptly returned to the yeast reaction tank so as not to reduce the yeast activity.
(3) In the activated sludge tank 42 in the latter stage, the yeast (sludge) that stores the organic matter that takes time to oxidize, such as fats and oils, and the unoxidized organic matter is removed, and from the yeast sedimentation basin 40 where the readily decomposable organic matter remains. Introduce runoff water and ensure activated sludge treatment under proper operating conditions.
In this way, each tank plays a role, and the processing is performed reliably and appropriately, so there are no problems that occur in the experimental controls (A) and (B). Unnecessary consumption can be prevented, and stable and efficient biological water treatment can be performed.
[0052]
In addition, since the yeast reaction tank 20 of the present invention cannot hold a certain amount or more of yeast sludge (carry over, etc.), the MLSS concentration in the tank does not become extremely high. It is possible to prevent the dismantling phenomenon from occurring. In addition, since the yeast sludge that is carried over and flows out from the apparatus of the present invention can be used as nutrients (organic substances that can be assimilated) of the activated sludge, the activated sludge tank can be appropriately put into the activated sludge tank as appropriate when the load is low. Can be operated under various load conditions.
[0053]
Furthermore, in the present invention, when the carrier is introduced as an immobilizing means for holding the yeast in the yeast reaction tank 20 when the influent water concentration increases and the MLSS concentration needs to be increased, the amount of yeast outflow is reduced. Met.
[0054]
As mentioned above, the yeast reaction tank 20 of the present invention contains oil but is not so much as an organic load as a whole, or depending on the components such as organic matter that takes time to decompose such as fat and oil and easily degradable organic matter. Was suitable for wastewater treatment with a difference in decomposition time.
[0055]
【Effect of the invention】
As described above, according to the present invention, it has aeration means, Oxidative decomposition of organic matter in wastewater in aerobic condition Microorganisms containing organic substance-utilizing yeast group By Contains fats and oils that are hard to decompose Yeast reaction for aerobic biological treatment of wastewater A yeast reaction tank containing the organic substance-assimilating yeast that is partitioned and formed integrally with the yeast reaction tank by a partition member provided with a water surface opening on the outflow end side of the tank and the yeast reaction tank. In an organic wastewater treatment apparatus consisting of a precipitation separation tank for solid-liquid separation of the mixed liquid into yeast sludge and treated water, the yeast reaction tank mixing that is provided in the precipitation separation tank and is transferred to and from the partition member A baffle that forms a downward flow path of the liquid and prevents the inside of the sedimentation separation tank from being stirred, and a sedimentation sludge guide portion that is provided at the bottom of the precipitation separation tank, and whose partitioning member side is an inclined descending end And an opening that is provided at the lower end of the partition member and directly transfers the yeast sludge settled in the sedimentation separation tank to the yeast reaction tank along the inclination of the sedimentation sludge guide section. Constitution When Therefore, even if hexane extract substances such as fats and oils, which are persistent organic substances adsorbed by yeast in the yeast reaction tank, are oxidized in the tank and are about to flow out, the organic substances containing the hexane extract substances are It can be transferred to a solid-liquid separation tank integrated with the yeast reaction tank, precipitated, and promptly returned to the yeast reaction tank. For this reason, it is possible to minimize the outflow of organic substances containing hexane-extracted substances such as fats and oils to the downstream equipment, and to provide oxidation and decomposition of readily decomposable organic substances when a downstream activated sludge tank is provided. .
[0056]
In addition, as described above, since the yeast sludge precipitated in the solid-liquid separation part of the yeast reaction tank is quickly returned to the aerobic yeast reaction tank, it is in an anaerobic state as compared with the conventional yeast treatment. The exposure time is greatly reduced. As a result, the biological activity of the organic wastewater can be constantly and efficiently performed because the yeast activity does not decrease, and energy (aeration, agitation, etc.) is added to restore the yeast activity as before. Can be significantly reduced and the cost can be reduced.
[0057]
Furthermore, in the yeast reaction tank, the yeast always preferentially adsorbs the same organic matter (such as hexane extract substances such as fats and oils that are difficult to be oxidatively decomposed). Extracellular oxygen secreted from microorganisms by aeration is also concentrated in the tank, so that the oxidative degradation efficiency can be expected to be further increased, and the yeast treatment activity and ability can be maximized.
[0058]
In addition, when a sedimentation basin is provided at the latter stage of the apparatus of the present invention, the yeast concentration of the treated water discharged from the solid-liquid separation tank is drastically lower than that of a conventional yeast reaction tank, so the sedimentation basin volume is reduced. This can reduce the site area and construction cost. Moreover, the yeast can be maintained in an aerobic state almost always, and the yeast activity can be maintained well. Thus, since the yeast can be maintained in a good state, the sedimentation is good, the SS concentration in the yeast reaction tank can be maintained high, and the inflow load can be further increased.
[0059]
In addition, when a secondary treatment facility such as an activated sludge tank is provided in the apparatus of the present invention, organic substances that take time to oxidize oils and fats are quickly adsorbed and removed in the yeast reaction tank and unoxidized in the solid-liquid separation tank. Stable sedimentation of yeast (sludge), etc., that stores organic matter, and oxidatively decomposes readily decomposable organic matter contained in the solid-liquid separation tank effluent in an activated sludge tank, resulting in stable and good treated water be able to.
[Brief description of the drawings]
FIG. 1 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 2 of the present invention.
FIG. 3 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 3 of the present invention.
FIG. 4 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 4 of the present invention.
FIG. 5 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 5 of the present invention.
FIG. 6 is a flow sheet showing an organic wastewater treatment apparatus according to Embodiment 6 of the present invention.
FIG. 7 is a flow sheet of a yeast reaction tank used in the experiment.
FIG. 8 is a flow sheet of an organic wastewater treatment apparatus used for another experiment.
FIG. 9 is a flow sheet of an organic wastewater treatment apparatus used for another experiment.
FIG. 10 is a flow sheet showing a conventional organic wastewater treatment apparatus.
[Explanation of symbols]
20 Yeast reaction tank
21 Partition member
21a Water surface opening
22 Solid-liquid separation tank
23 Baffle
24 Sedimentation sludge guide
25 Sludge retention part
26 Membrane separator
30 Inflow water pipeline
31 Air diffuser (air diffuser)
32 Blower
33 Sludge return pipe (sludge return means)
34 Pump (sludge return means)
35 opening

Claims (1)

Have aeration means,
Yeast reaction tank that aerobically biologically treats wastewater containing fats and oils of refractory organic substances by microorganisms containing organic matter-assimilating yeast that oxidatively decomposes organic matter in wastewater in an aerobic state
and
Water surface opening is partitioned and formed integrally with the yeast reactor by a partition member provided on the outflow end side of the yeast reactor
Sedimentation separation tank for solid-liquid separation of the yeast reactor mixture containing the organic materials of yeast flowing from the water surface openings and treated water with yeast sludge
In the organic wastewater treatment equipment consisting of
Provided in the settling tank,
Form a downward flow path of the yeast reaction tank mixed liquid that is advected between the partition member,
A baffle for preventing the inside of the precipitation separation tank from being stirred;
Provided at the bottom of the settling tank,
The settling sludge guide part on which the partition member side becomes an inclined descending end and the lower end of the partition member,
An organic wastewater treatment apparatus comprising: an opening for directly transferring yeast sludge settled in the sedimentation separation tank to the yeast reaction tank along an inclination of the sedimentation sludge guide section .

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