JPH08299995A - Treatment of organic waste liquid - Google Patents
Treatment of organic waste liquidInfo
- Publication number
- JPH08299995A JPH08299995A JP11345695A JP11345695A JPH08299995A JP H08299995 A JPH08299995 A JP H08299995A JP 11345695 A JP11345695 A JP 11345695A JP 11345695 A JP11345695 A JP 11345695A JP H08299995 A JPH08299995 A JP H08299995A
- Authority
- JP
- Japan
- Prior art keywords
- sludge
- ozone
- tank
- treatment
- digestion
- 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.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/20—Sludge processing
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は有機性排液を生物処理
し、余剰汚泥を消化により減容化するようにした処理方
法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a treatment method in which organic waste liquid is biologically treated and excess sludge is reduced in volume by digestion.
【０００２】[0002]
【従来の技術】有機性排液を活性汚泥の存在下に好気的
に生物処理する方法では、難脱水性の余剰活性汚泥が大
量に生成する。また嫌気性汚泥の存在下に嫌気的に処理
する方法でも、大量の余剰消化汚泥が生成する。このよ
うな余剰汚泥の減容化のために、余剰汚泥を好気的また
は嫌気的に消化する方法が行われている。このうち好気
性消化では、余剰汚泥を消化槽で単純に曝気して消化
し、曝気汚泥を固液分離して分離汚泥を消化槽に返送し
ている。また嫌気性消化では、余剰汚泥を消化槽に投入
し、嫌気性細菌の作用で消化している。2. Description of the Related Art In the method of aerobically treating organic waste liquid in the presence of activated sludge, a large amount of surplus activated sludge that is hardly dehydrated is produced. A large amount of excess digested sludge is also produced by a method of anaerobically treating in the presence of anaerobic sludge. In order to reduce the volume of such excess sludge, a method of aerobically or anaerobically digesting the excess sludge is used. Of these, in aerobic digestion, excess sludge is simply aerated and digested in a digestion tank, the aerated sludge is subjected to solid-liquid separation, and the separated sludge is returned to the digestion tank. In anaerobic digestion, excess sludge is put into a digestion tank and digested by the action of anaerobic bacteria.
【０００３】このような消化方法は、好気性または嫌気
性生物の作用を利用して消化するものであるが、余剰汚
泥自体生物処理を経て生物学的に安定した汚泥であるた
め、汚泥の減容化には限度があり、通常余剰汚泥の３０
〜４０％が減容されるにすぎない。[0003] Such a digestion method utilizes the action of aerobic or anaerobic organisms, but since the excess sludge itself is biologically stable sludge through biological treatment, it reduces sludge. There is a limit to the capacity, and it is usually 30
Only -40% is reduced.
【０００４】このような点を改善するために、余剰汚泥
をオゾン処理により酸化分解して好気性消化を行う方法
が提案されている（例えば特開昭５５−８８３５号）。
しかし、この方法では発生する余剰汚泥をすべてオゾン
処理するため、オゾン消費量が多くなるとともに、消化
に伴って汚泥が生成するので、排出汚泥量をゼロに近づ
けることはできない。In order to improve such a point, a method has been proposed in which excess sludge is oxidatively decomposed by ozone treatment to perform aerobic digestion (for example, JP-A-55-8835).
However, in this method, the excess sludge generated is all ozone-treated, so that the ozone consumption increases and the sludge is generated with the digestion, so the amount of discharged sludge cannot be brought close to zero.
【０００５】また有機性汚泥を嫌気性消化した消化汚泥
を加熱して可溶化し、消化槽に返送して減容化する方法
も知られている（例えば特開平１−２２４１００号）。
しかしこの方法では高温に加熱するため多大のエネルギ
ー源を必要とするほか、単に可溶化して返送しただけで
は汚泥の減容化効率は悪く、排出汚泥量をゼロに近づけ
ることはできない。A method is also known in which the digested sludge obtained by anaerobically digesting the organic sludge is heated to be solubilized, and the digested sludge is returned to the digestion tank to reduce the volume (for example, JP-A-1-224100).
However, this method requires a large amount of energy source because it is heated to a high temperature, and the volume reduction efficiency of sludge is poor and the amount of discharged sludge cannot be approached to zero simply by solubilizing and returning the sludge.
【０００６】このほか生物処理工程本体において発生す
る汚泥をオゾン処理して生物処理工程に循環することに
より、発生する余剰汚泥量を少なくし、場合によっては
発生汚泥量をゼロに近づける方法も提案されている（例
えば特開平６−２０６０８８号）。しかしこの方法では
生物処理工程で発生する汚泥をそのままオゾン処理する
ため、オゾン消費量が多くなるとともに、オゾン処理に
よって汚泥がＢＯＤ化するため生物処理工程の負荷が増
大し、元々負荷の大きい系では処理効果が低下する場合
がある。[0006] In addition, a method has also been proposed in which the amount of excess sludge generated is reduced by treating the sludge generated in the body of the biological treatment process with ozone and circulating it in the biological treatment process, and in some cases the amount of generated sludge approaches zero. (For example, JP-A-6-206088). However, in this method, since the sludge generated in the biological treatment process is ozone-treated as it is, the ozone consumption increases, and the load of the biological treatment process increases because the sludge becomes BOD by the ozone treatment. The processing effect may decrease.
【０００７】[0007]
【発明が解決しようとする課題】本発明は、上記のよう
な従来の問題点を解決するため、オゾン消費量を少なく
し、しかも生物処理工程に悪影響を与えることなく余剰
汚泥の減容化が可能であり、しかも消化効率を高くし
て、排出汚泥量をゼロに近づけることが可能な有機性排
液の処理方法を提案することである。In order to solve the above-mentioned conventional problems, the present invention reduces ozone consumption and reduces the volume of excess sludge without adversely affecting the biological treatment process. It is an object of the present invention to propose a method for treating an organic waste liquid which is capable of increasing the digestion efficiency and makes the amount of discharged sludge close to zero.
【０００８】[0008]
【課題を解決するための手段】本発明は、有機性排液を
生物処理する生物処理工程と、生物処理工程から排出さ
れる余剰汚泥を消化する汚泥消化工程と、消化汚泥の少
なくとも一部をオゾン処理して汚泥消化工程に循環する
オゾン処理工程とを含む有機性排液の処理方法である。The present invention provides a biological treatment process for biologically treating an organic waste liquid, a sludge digestion process for digesting excess sludge discharged from the biological treatment process, and at least a part of the digested sludge. It is a method for treating an organic waste liquid, which comprises an ozone treatment step of ozone treatment and circulation to a sludge digestion step.
【０００９】本発明において処理の対象となる有機性排
液は、生物処理によって処理される有機物を含有する排
液であるが、難生物分解性の有機物または無機物が含有
されていてもよい。このような有機性排液としては下
水、し尿、食品工場排水、その他の産業排液などがあげ
られる。The organic drainage to be treated in the present invention is a drainage containing an organic substance to be treated by a biological treatment, but it may also contain a hardly biodegradable organic substance or an inorganic substance. Examples of such organic drainage liquid include sewage, night soil, food factory wastewater, and other industrial wastewater.
【００１０】このような有機性排液を生物処理する生物
処理工程は、好気性生物処理でも嫌気性生物処理でもよ
い。好気性生物処理としては、活性汚泥法、生物膜法な
どがあげられる。活性汚泥法は有機性排液を活性汚泥の
存在下に好気性生物処理する処理法であり、有機性排液
を曝気槽で活性汚泥と混合して曝気し、混合液を固液分
離槽で固液分離し、分離汚泥の一部を曝気槽に返送する
標準活性汚泥法が一般的であるが、これを変形した他の
処理法でもよい。また生物膜法は担体に生物膜を形成し
て好気性下に排液と接触させる処理である。また嫌気性
処理としては、嫌気性消化法、高負荷嫌気性処理法など
があげられる。The biological treatment step for biologically treating such organic waste liquid may be an aerobic biological treatment or an anaerobic biological treatment. Examples of aerobic biological treatment include activated sludge method and biofilm method. The activated sludge method is a treatment method of aerobic biological treatment of organic effluent in the presence of activated sludge.The organic effluent is mixed with activated sludge in an aeration tank and aerated, and the mixed solution is separated in a solid-liquid separation tank. The standard activated sludge method in which solid-liquid separation is performed and a part of the separated sludge is returned to the aeration tank is generally used, but other treatment methods modified from this may be used. The biofilm method is a treatment in which a biofilm is formed on a carrier and aerobically brought into contact with the drainage. Examples of the anaerobic treatment include an anaerobic digestion method and a high-load anaerobic treatment method.
【００１１】本発明では上記のような生物処理工程から
排出される余剰汚泥を汚泥消化工程において消化する。
上記の生物処理工程から排出される余剰汚泥は、生物処
理工程が好気性処理および嫌気性処理のどちらの場合で
も、通性嫌気性菌を中心とする微生物菌体を主体とし、
これに有機物および無機物等が付着した状態のものであ
るから、ほぼ同様の性状を有し、どちらも好気性および
嫌気性消化により減容化される。In the present invention, the excess sludge discharged from the above biological treatment process is digested in the sludge digestion process.
Excess sludge discharged from the biological treatment step is mainly microbial cells centering on facultative anaerobic bacteria in both cases where the biological treatment step is aerobic treatment and anaerobic treatment,
Since the organic substance and the inorganic substance are attached to this, they have almost the same properties, and both are reduced in volume by aerobic and anaerobic digestion.
【００１２】このため汚泥消化工程における消化方法と
しては好気性消化および嫌気性消化のいずれの消化方法
を採用してもよい。好気性消化は余剰汚泥を消化槽に導
入して曝気し、曝気した汚泥の一部を取出して固液分離
する方法であるが、分離汚泥の一部を消化槽に循環する
のが好ましい。嫌気性消化は余剰汚泥を消化槽に導入し
て嫌気状態に維持して消化し、消化液の一部を取出して
固液分離する方法であるが、この場合も分離汚泥の一部
を消化槽に循環するのが好ましい。Therefore, as the digestion method in the sludge digestion step, either aerobic digestion or anaerobic digestion may be adopted. Aerobic digestion is a method in which excess sludge is introduced into a digestion tank for aeration, and a part of the aerated sludge is taken out for solid-liquid separation, but it is preferable to circulate a part of the separated sludge in the digestion tank. Anaerobic digestion is a method in which excess sludge is introduced into the digestion tank and maintained in an anaerobic state for digestion, and a part of the digested liquid is extracted for solid-liquid separation. It is preferable to circulate in
【００１３】消化の条件は従来から採用されている条件
をそのまま適用することができる。たとえば好気性消化
では、有機物負荷０．８〜１．０ｋｇ−ＶＳＳ／ｍ3・
日で１０〜１５日間処理を行う。嫌気性消化では、有機
物負荷０．６〜１．６ｋｇ−ＶＳＳ／ｍ3・日で１５〜
３０日間処理を行う。好気性消化の方が嫌気性消化に比
べて反応速度が早く、有臭ガスの発生がないので好まし
い。As the digestion conditions, the conditions conventionally used can be applied as they are. For example, in aerobic digestion, organic load 0.8-1.0 kg-VSS / m 3 ·
Process for 10 to 15 days a day. In anaerobic digestion, organic load of 0.6-1.6kg-VSS / m 3 · 15-
Treat for 30 days. Aerobic digestion is preferable because it has a faster reaction rate than anaerobic digestion and does not generate odorous gas.
【００１４】本発明では上記の汚泥消化工程における消
化汚泥の少なくとも一部を、オゾン処理工程においてオ
ゾン処理し、汚泥消化工程に循環する。オゾン処理する
消化汚泥は、消化槽から抜出したものをそのままオゾン
処理してもよいが、固液分離した分離汚泥をオゾン処理
するのが好ましい。固液分離した消化汚泥をすべてオゾ
ン処理して循環してもよいが、前述のように一部をオゾ
ン処理することなく循環し、残部をそのまままたは濃縮
してオゾン処理し循環するのが好ましい。In the present invention, at least a part of the digested sludge in the above sludge digestion step is subjected to ozone treatment in the ozone treatment step and circulated to the sludge digestion step. The digested sludge to be treated with ozone may be ozone treated as it is extracted from the digestion tank, but it is preferable to subject the separated sludge obtained by solid-liquid separation to ozone treatment. The digested sludge that has been solid-liquid separated may be entirely ozone-treated and circulated, but as described above, it is preferable to circulate a part of the digested sludge without ozone-treating it and circulate the rest as it is or by concentrating it and then ozone-treating it.
【００１５】オゾン処理は、消化汚泥をオゾンと接触さ
せることにより行う。接触方法としては、オゾン処理槽
に消化汚泥を導入してオゾンを吹込む方法、機械攪拌に
よる方法、充填層を利用する方法などが採用できる。オ
ゾンとしてはオゾンガスの他、オゾン含有空気、オゾン
化空気などが使用できる。オゾンの使用量は０．００５
〜０．０４ｇ−Ｏ3／ｇ−ＶＳＳ、好ましくは０．０１
〜０．０３ｇ−Ｏ3／ｇ−ＶＳＳとするのが望ましい。Ozone treatment is carried out by bringing digested sludge into contact with ozone. As a contact method, a method of introducing digested sludge into an ozone treatment tank and blowing ozone, a method of mechanical stirring, a method of utilizing a packed bed, and the like can be adopted. As ozone, ozone-containing air, ozonized air, or the like can be used in addition to ozone gas. The amount of ozone used is 0.005
~0.04g-O 3 / g-VSS , preferably 0.01
It is desirable to be 0.03 g-O 3 / g-VSS.
【００１６】[0016]
【作用】オゾン処理により消化汚泥中の菌体は死滅し、
その他の有機物とともに酸化分解されて、低分子の有機
物および一部無機物が生成する。このようなオゾン処理
汚泥は消化槽に循環することにより、微生物の基質とし
て利用され分解される。[Function] Ozone treatment kills bacterial cells in digested sludge,
It is oxidatively decomposed together with other organic substances to generate low-molecular organic substances and some inorganic substances. By circulating such an ozone-treated sludge in the digestion tank, it is used as a substrate for microorganisms and decomposed.
【００１７】上記の処理では、生物処理工程が好気性お
よび嫌気性のどちらの処理の場合でも、通性嫌気性菌を
中心とする微生物菌体と、これに付着する有機物および
無機物とからなる余剰汚泥が生成するので、そのまま汚
泥消化工程において好気性または嫌気性消化により減容
化される。この場合汚泥の減容化率は一般に３０〜４０
％であるため、消化汚泥をオゾン処理すると、消化前の
余剰汚泥の全量をオゾン処理する場合に比べて、オゾン
処理汚泥量は３０〜４０％少なくなり、オゾン消費量は
減少する。In the above treatment, regardless of whether the biological treatment process is an aerobic treatment or an anaerobic treatment, a surplus consisting of microbial cells centering on facultative anaerobic bacteria and organic substances and inorganic substances attached thereto. Since sludge is produced, the volume is directly reduced by aerobic or anaerobic digestion in the sludge digestion process. In this case, the sludge volume reduction rate is generally 30 to 40.
Therefore, when the digested sludge is treated with ozone, the ozone-treated sludge amount is reduced by 30 to 40% and the ozone consumption amount is reduced as compared with the case where the entire amount of the excess sludge before digestion is treated with ozone.
【００１８】一方汚泥消化工程で生成する消化汚泥を全
量オゾン処理して循環すると、消化槽内はオゾン処理に
より菌体が死滅して基質に転換したオゾン処理汚泥と、
消化の対象となる余剰汚泥が大量に投入されることにな
り、消化速度が低下するが、オゾン処理しない消化汚泥
の一部を循環すると、この消化汚泥は活性化されている
ため消化速度が高くなる。On the other hand, when the whole digested sludge produced in the sludge digestion step is treated with ozone and circulated, the inside of the digestion tank is ozone treated sludge in which the cells have been killed by the ozone treatment and converted into a substrate,
Excessive sludge to be digested will be input in large quantities and the digestion rate will decrease, but if a portion of the digested sludge that is not subjected to ozone treatment is circulated, this digested sludge will be activated and the digestion rate will be high. Become.
【００１９】また汚泥消化工程から排出される消化汚泥
をオゾン処理して循環するという方法では、消化汚泥は
増量していくので、一部の消化汚泥を余剰消化汚泥とし
て排出しなければならず、排出汚泥をゼロに近づけるこ
とはできない。すなわちオゾン処理を行わない汚泥消化
工程では、栄養を断って消化条件に維持することによ
り、この条件に適応できる菌体が生き残こり、体内に取
込んだ有機物を自己消化するとともに、適応できないで
死滅した菌体を消化して減容化するため、減容化率が３
０〜４０％に限定される。ここで消化汚泥をオゾン処理
して循環すると、これが基質（餌）となって生き残った
菌体が増殖するため、汚泥量は増量していく。Further, in the method in which the digested sludge discharged from the sludge digestion process is treated with ozone and circulated, the digested sludge is increased in amount, so that a part of the digested sludge must be discharged as excess digested sludge, The discharged sludge cannot be brought close to zero. In other words, in the sludge digestion process that does not perform ozone treatment, by declining nutrition and maintaining digestion conditions, cells that can adapt to these conditions survive and self-digest the organic substances taken up in the body, and die because they cannot adapt. The volume reduction rate is 3 because the digested cells are digested to reduce the volume.
It is limited to 0-40%. When the digested sludge is treated with ozone and circulated, the surviving bacterial cells serve as a substrate (bait) and proliferate. Therefore, the amount of sludge increases.
【００２０】例えば４０％の減容化により、６０％の消
化汚泥が発生すると仮定すると、この６０％の消化汚泥
をオゾン処理して循環すると、これを基質として菌体が
増殖し、消化汚泥がｘ％増量する。従って、余剰消化汚
泥をオゾン処理して循環するだけでは汚泥量が増量する
ため、余剰消化汚泥を系外に排出しなければならない。For example, assuming that 60% of the digested sludge is generated by reducing the volume by 40%, when the 60% digested sludge is subjected to ozone treatment and circulated, bacterial cells are grown using this as a substrate and digested sludge is produced. Increase x%. Therefore, the amount of sludge increases only by ozone treatment and circulation of the excess digested sludge, and the excess digested sludge must be discharged to the outside of the system.
【００２１】そこで余剰消化汚泥量がゼロとなるよう
に、消化汚泥の発生量より多い汚泥を消化汚泥として抜
出し、これをオゾン処理して循環すると、過剰に抜出し
た汚泥量を増殖した汚泥量がバランスし、見掛上汚泥の
増加量がゼロに近づく。この場合でも無機化した汚泥の
蓄積を避けるために、最小限の消化汚泥を排出するのが
望ましい。[0021] Therefore, in order to make the amount of excess digested sludge to be zero, sludge larger than the amount of digested sludge generated is extracted as digested sludge, which is subjected to ozone treatment and circulated. Balanced and apparent increase in sludge amount near zero. Even in this case, it is desirable to discharge the minimum digested sludge in order to avoid the accumulation of mineralized sludge.
【００２２】このように過剰の汚泥をオゾン処理する
と、消化効率は低下するが、好気性消化槽では通常ＳＲ
Ｔを１５日程度と比較的長くとって運転されるため、オ
ゾン処理によりＳＲＴが短くなっても余裕のある運転が
可能であり、生物処理工程におけるオゾン処理の場合に
比べて効率の低下はそれほど重大ではない。When the excess sludge is treated with ozone in this manner, the digestion efficiency is lowered, but in an aerobic digester, SR is usually used.
Since T is operated for a relatively long time of about 15 days, it is possible to operate with plenty of time even if the SRT is shortened by ozone treatment, and the efficiency is not much lower than in the case of ozone treatment in the biological treatment process. Not serious.
【００２３】本発明では、有機性排液の生物処理工程か
ら独立した汚泥処理工程において汚泥をオゾン処理して
減容化を行うため、生物処理工程においてオゾン処理す
る場合に比べて生物処理系を安定して操作することがで
き、処理水質の管理が容易になる。このため排液中にＳ
Ｓ性有機質含有量が多く、排液中のＢＯＤあたりの汚泥
発生量が多い場合でも効率よく処理を行うことが可能に
なる。In the present invention, since the sludge is subjected to ozone treatment in the sludge treatment process independent of the biological treatment process of the organic effluent to reduce the volume, the biological treatment system is used as compared with the case where the ozone treatment is performed in the biological treatment process. It can be operated stably and the quality of treated water can be controlled easily. For this reason, S
Even if the S-organic content is high and the amount of sludge generated per BOD in the effluent is high, the treatment can be performed efficiently.
【００２４】[0024]
【実施例】以下、本発明の実施例を図面により説明す
る。図１は実施例の処理装置を示す系統図であり、１は
生物処理槽、２は固液分離槽、３は汚泥消化槽、４は固
液分離槽、５はオゾン処理槽、６はオゾン発生機であ
る。生物処理槽１は内部に散気装置７を有しており、有
機性排液を好気的に生物処理するように構成されてい
る。汚泥消化槽３も内部に散気装置８を有し、余剰汚泥
を好気性消化するように構成されている。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram showing a treatment apparatus of the embodiment, 1 is a biological treatment tank, 2 is a solid-liquid separation tank, 3 is a sludge digestion tank, 4 is a solid-liquid separation tank, 5 is an ozone treatment tank, and 6 is ozone. It is a generator. The biological treatment tank 1 has an air diffuser 7 therein and is configured to aerobically biologically treat the organic waste liquid. The sludge digestion tank 3 also has an air diffuser 8 inside and is configured to aerobically digest excess sludge.
【００２５】上記の装置による有機性排液の処理方法
は、生物処理工程として生物処理槽１に排液１１および
返送汚泥１２を導入して混合し、散気装置７から散気し
て好気性下に生物処理を行う。混合液の一部１３は固液
分離槽２に抜出して固液分離し、分離液を処理液１４と
して排出する。分離汚泥１５は一部を返送汚泥１２とし
て生物処理槽１に返送し、残部を余剰汚泥１６と汚泥消
化槽３に送る。In the method for treating organic effluent with the above apparatus, the effluent 11 and the returned sludge 12 are introduced into the biological treatment tank 1 and mixed with each other as a biological treatment step, and aerated from the aeration device 7 to be aerobic. Biological treatment underneath. A part 13 of the mixed liquid is extracted into the solid-liquid separation tank 2 for solid-liquid separation, and the separated liquid is discharged as a treatment liquid 14. Part of the separated sludge 15 is returned to the biological treatment tank 1 as return sludge 12, and the rest is sent to the excess sludge 16 and the sludge digestion tank 3.
【００２６】汚泥消化工程では汚泥消化槽３に余剰汚泥
１６と循環汚泥１７を導入して混合し、散気装置８から
散気して好気性消化を行う。槽内液の一部１８は固液分
離槽４に導入して固液分離し、分離液１９を排出し、分
離した消化汚泥２１は一部を循環汚泥１７として、消化
槽３に循環する。In the sludge digestion step, the excess sludge 16 and the circulation sludge 17 are introduced into the sludge digestion tank 3 and mixed, and air is diffused from the air diffuser 8 to perform aerobic digestion. A part 18 of the in-tank liquid is introduced into the solid-liquid separation tank 4 for solid-liquid separation, the separated liquid 19 is discharged, and a part of the separated digested sludge 21 is circulated to the digestion tank 3 as a circulation sludge 17.
【００２７】オゾン処理工程では、消化汚泥の他の一部
は引抜汚泥２２としてオゾン処理槽５に導入し、オゾン
発生機６からオゾンガス２３を吹込んでオゾン処理を行
い、オゾン処理汚泥２４は汚泥消化槽３に循環して消化
に供する。消化汚泥２１の他の一部は必要により、無機
物濃度の上昇を防止するために排出汚泥２５として排出
する。In the ozone treatment step, the other part of the digested sludge is introduced into the ozone treatment tank 5 as the drawn-out sludge 22, ozone gas 23 is blown from the ozone generator 6 to perform ozone treatment, and the ozone-treated sludge 24 is sludge digested. It circulates in the tank 3 and is used for digestion. If necessary, the other part of the digested sludge 21 is discharged as discharged sludge 25 in order to prevent an increase in the concentration of inorganic substances.
【００２８】上記の処理では消化汚泥２１の一部を引抜
汚泥２２としてオゾン処理して汚泥消化槽３に戻すこと
により、オゾン処理汚泥２４は基質として消化され、減
容化される。この場合、消化汚泥２１は余剰汚泥１６が
消化槽３で消化されて３０〜４０％減容化されているの
で、余剰汚泥１６をオゾン処理して生物処理槽１へ循環
する場合よりもオゾン処理する汚泥量は少なくなり、オ
ゾン消費量は少なくなる。In the above treatment, a part of the digested sludge 21 is ozone-treated as the extracted sludge 22 and returned to the sludge digestion tank 3, so that the ozone-treated sludge 24 is digested as a substrate and reduced in volume. In this case, since the excess sludge 16 is digested in the digestion tank 3 and the volume of the digested sludge 21 is reduced by 30 to 40%, the excess sludge 16 is ozone-treated as compared with the case where the excess sludge 16 is circulated to the biological treatment tank 1 by ozone treatment. The amount of sludge to be discharged is reduced and the amount of ozone consumption is also reduced.
【００２９】また消化汚泥２１をすべてオゾン処理して
消化槽３に循環すると、消化槽３の負荷が大きくなって
消化速度が低下するが、オゾン処理しない消化汚泥を循
環汚泥として循環させることにより活性化した汚泥を戻
すことができ、消化効率を高くして消化時間を短縮する
ことができる。ここでオゾン処理する引抜汚泥２２の量
を通常発生する余剰消化汚泥の量より多くすると、汚泥
の減容量と増殖量がバランスして余剰消化汚泥の発生量
をゼロに近づけることができる。When the digested sludge 21 is entirely ozone-treated and circulated in the digestion tank 3, the load on the digestion tank 3 is increased and the digestion rate is reduced. However, it is activated by circulating the digested sludge that is not ozone-treated as circulation sludge. The sludge that has turned into liquefied water can be returned, and the efficiency of digestion can be improved and the digestion time can be shortened. If the amount of the drawn-out sludge 22 to be treated with ozone is set to be larger than the amount of the excess digested sludge that is normally generated, the volume of the sludge reduced and the growth amount are balanced, and the amount of the excess digested sludge generated can be brought close to zero.
【００３０】生物処理で発生する余剰汚泥１６をオゾン
処理して生物処理槽１に循環すると、前述のようにオゾ
ン処理量が多くなるほか、生物処理槽１の負荷が増大し
て生物処理に影響を与える場合があるが、上記のように
余剰汚泥１６を汚泥消化槽３で消化し、消化汚泥をオゾ
ン処理して消化槽３に循環する方法では、オゾン処理汚
泥の負荷は消化槽３にかかるだけで、生物処理槽１には
影響しないので生物処理槽１における排液の生物処理は
安定して行うことができ、処理水質の管理は容易であ
る。When the excess sludge 16 generated in the biological treatment is ozone-treated and circulated in the biological treatment tank 1, the ozone treatment amount is increased as described above, and the load of the biological treatment tank 1 is increased to affect the biological treatment. However, in the method in which the excess sludge 16 is digested in the sludge digestion tank 3 and the digested sludge is ozone-treated and circulated to the digestion tank 3 as described above, the load of the ozone-treated sludge is applied to the digestion tank 3. Since it does not affect the biological treatment tank 1, the biological treatment of the effluent in the biological treatment tank 1 can be stably performed, and the treated water quality can be easily managed.
【００３１】固液分離槽４の分離液１９は別途処理する
か、あるいは生物処理槽１に循環して処理する。オゾン
処理により難生物分解性のＣＯＤが生成する場合がある
が、この場合は凝集処理、吸着等により除去することが
できる。この場合もオゾン処理汚泥を生物処理槽１に循
環する場合よりも、消化槽３に循環する方が処理対象と
なる分離液量が少なくなり、処理が容易となる。The separated liquid 19 in the solid-liquid separation tank 4 is treated separately or is circulated in the biological treatment tank 1 for treatment. Ozone treatment may produce COD that is hardly biodegradable, but in this case, COD can be removed by coagulation treatment, adsorption, or the like. Also in this case, the amount of separated liquid to be treated is smaller in the case where the ozone-treated sludge is circulated in the biological treatment tank 1, and the treatment is easier.
【００３２】上記の実施例は生物処理槽１として好気性
処理を行うものであるが、嫌気性処理を行う場合にも適
用できる。また汚泥消化槽３として好気性消化を行う例
を示しているが、これを嫌気性消化を行う場合も同様に
適用可能である。この場合、嫌気性消化された消化汚泥
を曝気して還元性物質を酸化した後オゾン処理すること
により、オゾン処理の効果を高めることができる。Although the above-mentioned embodiment performs aerobic treatment as the biological treatment tank 1, it can also be applied to the case of performing anaerobic treatment. Further, an example of performing aerobic digestion as the sludge digestion tank 3 is shown, but the same can be applied to the case of performing anaerobic digestion. In this case, the effect of ozone treatment can be enhanced by aerating the digested sludge that has been anaerobically digested to oxidize the reducing substance and then subjecting it to ozone treatment.
【００３３】以下、試験例について説明する。 実施例１ ＢＯＤ２５０ｍｇ／ｌ、ＳＳ２７０ｍｇ／ｌの下水を、
下水量１０ｍ3／日、ＨＲＴ１日、ＭＬＳＳ濃度３００
０〜４０００ｍｇ／ｌ、水温１３〜１６℃で活性汚泥処
理し、処理水ＢＯＤ＜５ｍｇ／ｌ、ＳＳ１０ｍｇ／ｌ、
ＣＯＤmn１１ｍｇ／ｌの処理水を得、１．５３ｋｇ−Ｄ
Ｓ／日（流入ＢＯＤの６１％）の余剰汚泥を排出してい
る下水処理系の余剰汚泥を好気性消化した。The test examples will be described below. Example 1 BOD 250 mg / l, SS270 mg / l sewage,
Sewage volume 10 m 3 / day, HRT 1 day, MLSS concentration 300
Activated sludge treatment at 0 to 4000 mg / l, water temperature 13 to 16 ° C., treated water BOD <5 mg / l, SS 10 mg / l,
COD mn 11 mg / l of treated water was obtained, 1.53 kg-D
The surplus sludge of the sewage treatment system, which is discharging the surplus sludge of S / day (61% of inflow BOD), was aerobically digested.
【００３４】好気性消化の条件は、消化槽容量２ lite
r、汚泥投入量０．１４ liter／日、投入汚泥濃度１１
０００ｍｇ−ＳＳ／ｌ、有機物負荷０．８ｋｇ−ＳＳ／
ｍ3・日である。２．８ｇ−ＳＳ／日の引抜汚泥をオゾ
ン注入率０．０１５ｇ−Ｏ3／ｇ−ＳＳでオゾン処理し
て消化槽に循環した。その結果、投入汚泥量１．５４ｇ
／日に対して排出汚泥量は０．０５ｇ／日となり、汚泥
有機物除去率は９７％となった。Conditions for aerobic digestion are as follows: digester tank capacity: 2 lite
r, sludge input 0.14 liter / day, input sludge concentration 11
000 mg-SS / l, organic load 0.8 kg-SS /
m 3 · day. The extracted sludge of 2.8 g-SS / day with ozone treatment with ozone injection rate 0.015g-O 3 / g-SS was circulated to the digester. As a result, input sludge amount 1.54g
The amount of sludge discharged was 0.05 g / day, and the sludge organic matter removal rate was 97%.
【００３５】比較例１ 実施例１において、オゾン処理せず発生する消化汚泥を
そのまま循環した場合の排出汚泥量は０．９５ｇ／日と
なり、汚泥有機物除去率は３８％であった。Comparative Example 1 In Example 1, when the digested sludge generated without ozone treatment was circulated as it was, the discharged sludge amount was 0.95 g / day, and the sludge organic matter removal rate was 38%.
【００３６】比較例２ 投入汚泥１．５４ｇ／日をオゾン注入率０．０１５ｇ−
Ｏ3／ｇ−ＳＳでオゾン処理したのち、実施例１と同じ
好気性消化槽で処理した。その結果、排出汚泥量は０．
６６ｇ／日となり、汚泥有機物除去率は５７％であっ
た。COMPARATIVE EXAMPLE 2 1.54 g / day of input sludge was injected at an ozone injection rate of 0.015 g-
After ozone treatment with O 3 / g-SS, it was treated in the same aerobic digester as in Example 1. As a result, the amount of sludge discharged was 0.
The amount was 66 g / day, and the sludge organic matter removal rate was 57%.
【００３７】[0037]
【発明の効果】本発明によれば、生物処理工程から排出
される余剰汚泥を汚泥消化工程で消化し、消化汚泥をオ
ゾン処理して汚泥消化工程に循環するようにしたので、
オゾン消費量を少なくし、しかも生物処理工程に悪影響
を与えることなく余剰汚泥の減容化が可能であり、しか
も消化効率を高くして、排出汚泥量をゼロに近づけるこ
とができる。According to the present invention, the excess sludge discharged from the biological treatment process is digested in the sludge digestion process, and the digested sludge is ozone-treated and circulated in the sludge digestion process.
It is possible to reduce the ozone consumption and to reduce the volume of the excess sludge without adversely affecting the biological treatment process. Moreover, it is possible to improve the digestion efficiency and bring the discharged sludge amount close to zero.
【図１】実施例の処理装置を示す系統図である。FIG. 1 is a system diagram showing a processing apparatus of an embodiment.
１ 生物処理槽 ２、４ 固液分離槽 ３ 汚泥消化槽 ５ オゾン処理槽 ６ オゾン発生機 ７、８ 散気装置 １１ 排液 １２ 返送汚泥 １４ 処理液 １５ 分離汚泥 １６ 余剰汚泥 １７ 循環汚泥 １９ 分離液 ２１ 消化汚泥 ２２ 引抜汚泥 ２４ オゾン処理汚泥 1 Biological treatment tank 2, 4 Solid-liquid separation tank 3 Sludge digestion tank 5 Ozone treatment tank 6 Ozone generator 7, 8 Air diffuser 11 Drainage 12 Return sludge 14 Treatment liquid 15 Separation sludge 16 Excess sludge 17 Circulation sludge 19 Separation liquid 21 Digested sludge 22 Extracted sludge 24 Ozone-treated sludge
Claims (1)
と、 生物処理工程から排出される余剰汚泥を消化する汚泥消
化工程と、 消化汚泥の少なくとも一部をオゾン処理して汚泥消化工
程に循環するオゾン処理工程とを含む有機性排液の処理
方法。1. A biological treatment step of biologically treating an organic waste liquid, a sludge digestion step of digesting excess sludge discharged from the biological treatment step, and an ozone treatment of at least a part of the digested sludge into a sludge digestion step. A method for treating organic waste liquid, which comprises a circulating ozone treatment step.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11345695A JP3921693B2 (en) | 1995-05-11 | 1995-05-11 | Organic wastewater treatment method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11345695A JP3921693B2 (en) | 1995-05-11 | 1995-05-11 | Organic wastewater treatment method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08299995A true JPH08299995A (en) | 1996-11-19 |
| JP3921693B2 JP3921693B2 (en) | 2007-05-30 |
Family
ID=14612707
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11345695A Expired - Fee Related JP3921693B2 (en) | 1995-05-11 | 1995-05-11 | Organic wastewater treatment method |
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| Country | Link |
|---|---|
| JP (1) | JP3921693B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002045881A (en) * | 2000-08-07 | 2002-02-12 | Shinko Pantec Co Ltd | Biological treatment method of organic waste water |
| JP2005199258A (en) * | 2003-12-16 | 2005-07-28 | Kurita Water Ind Ltd | Anaerobic digestion treatment apparatus of organic waste solution |
| JP2005334886A (en) * | 2005-08-23 | 2005-12-08 | Kobelco Eco-Solutions Co Ltd | Activated sludge treatment method and activated sludge treatment apparatus therefor |
| JP2007038166A (en) * | 2005-08-04 | 2007-02-15 | Japan Sewage Works Agency | Apparatus for treating organic liquid waste |
| JP2008036571A (en) * | 2006-08-09 | 2008-02-21 | Fuji Koki Kk | Volume reduction apparatus of waste sludge, and volume reduction methode of waste sludge |
| JPWO2006011241A1 (en) * | 2004-07-30 | 2008-05-01 | 永和国土環境株式会社 | Wastewater purification equipment |
| JP2009022955A (en) * | 2008-11-04 | 2009-02-05 | Toshiba Corp | Method for treating organic solid-containing waste water, and treatment method therefor |
-
1995
- 1995-05-11 JP JP11345695A patent/JP3921693B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002045881A (en) * | 2000-08-07 | 2002-02-12 | Shinko Pantec Co Ltd | Biological treatment method of organic waste water |
| JP2005199258A (en) * | 2003-12-16 | 2005-07-28 | Kurita Water Ind Ltd | Anaerobic digestion treatment apparatus of organic waste solution |
| JP4507712B2 (en) * | 2003-12-16 | 2010-07-21 | 栗田工業株式会社 | Anaerobic digester for organic waste liquid |
| JPWO2006011241A1 (en) * | 2004-07-30 | 2008-05-01 | 永和国土環境株式会社 | Wastewater purification equipment |
| US7972500B2 (en) | 2004-07-30 | 2011-07-05 | Eiwa Land Environment Co., Ltd | Waste water purification apparatus |
| JP2007038166A (en) * | 2005-08-04 | 2007-02-15 | Japan Sewage Works Agency | Apparatus for treating organic liquid waste |
| JP2005334886A (en) * | 2005-08-23 | 2005-12-08 | Kobelco Eco-Solutions Co Ltd | Activated sludge treatment method and activated sludge treatment apparatus therefor |
| JP2008036571A (en) * | 2006-08-09 | 2008-02-21 | Fuji Koki Kk | Volume reduction apparatus of waste sludge, and volume reduction methode of waste sludge |
| JP2009022955A (en) * | 2008-11-04 | 2009-02-05 | Toshiba Corp | Method for treating organic solid-containing waste water, and treatment method therefor |
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