JPS6365395B2 - - Google Patents
Info
- Publication number
- JPS6365395B2 JPS6365395B2 JP17357484A JP17357484A JPS6365395B2 JP S6365395 B2 JPS6365395 B2 JP S6365395B2 JP 17357484 A JP17357484 A JP 17357484A JP 17357484 A JP17357484 A JP 17357484A JP S6365395 B2 JPS6365395 B2 JP S6365395B2
- Authority
- JP
- Japan
- Prior art keywords
- tank
- sludge
- meter
- value
- aeration
- 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.)
- Expired
Links
- 239000010802 sludge Substances 0.000 claims description 49
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 26
- 238000005273 aeration Methods 0.000 claims description 22
- 238000004062 sedimentation Methods 0.000 claims description 20
- 239000002351 wastewater Substances 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 11
- 230000033116 oxidation-reduction process Effects 0.000 claims description 11
- 229910052760 oxygen Inorganic materials 0.000 claims description 11
- 239000001301 oxygen Substances 0.000 claims description 11
- 239000006228 supernatant Substances 0.000 claims description 8
- 238000007599 discharging Methods 0.000 claims 1
- 238000000926 separation method Methods 0.000 claims 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 12
- 229910052698 phosphorus Inorganic materials 0.000 description 12
- 239000011574 phosphorus Substances 0.000 description 12
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 7
- 229910002092 carbon dioxide Inorganic materials 0.000 description 5
- 239000001569 carbon dioxide Substances 0.000 description 5
- 244000005700 microbiome Species 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 238000002386 leaching Methods 0.000 description 4
- 241000894006 Bacteria Species 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- MMDJDBSEMBIJBB-UHFFFAOYSA-N [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[NH6+3] Chemical compound [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[NH6+3] MMDJDBSEMBIJBB-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000001546 nitrifying effect Effects 0.000 description 2
- JVMRPSJZNHXORP-UHFFFAOYSA-N ON=O.ON=O.ON=O.N Chemical compound ON=O.ON=O.ON=O.N JVMRPSJZNHXORP-UHFFFAOYSA-N 0.000 description 1
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 239000010840 domestic wastewater Substances 0.000 description 1
- 235000015097 nutrients Nutrition 0.000 description 1
- 125000001477 organic nitrogen group Chemical group 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
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
Landscapes
- Activated Sludge Processes (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Description
「産業上の利用分野」
この発明は、有機性廃水の活性汚泥処理法の最
終工程に用いられる沈澱槽に関するものである。
「従来の技術」
従来、有機性廃水の脱リンを伴なう活性汚泥法
による処理は、第２図に示すような工程により行
なわれている。
すなわち、原廃水および返送汚泥は、まず嫌気
性槽１に送られる。この嫌気性槽１はDO（溶存
酸素）濃度が低く保たれた槽であつて、この槽１
に送られた返送汚泥中の微生物は、その性質によ
りここで廃水中にリンを放出する。そして、この
微生物は廃水の流れと共に脱窒素槽２を介して硝
化槽３へ送られる。
上記脱窒素槽２では、活性汚泥中の脱窒素菌が
硝化槽３から返送されてくる廃水中に含まれてい
る硝酸性窒素および亜硝酸性窒素（NOx―Ｎ）
に結合している酸素を利用して、原廃水中の
BOD成分（有機栄養源）を同化するので、NOx
―Ｎの窒素は窒素ガスとして大気中に放出され、
これにより窒素が除去される。
ついで、この脱窒素された廃水は、硝化槽３に
導入される。この脱窒素槽２から送られてくる廃
水には原廃水中に含有されていた有機性窒素およ
びアンモニア性窒素が含まれており、硝化槽３で
は活性汚泥中の亜硝酸化菌、硝化菌によりこれら
窒素成分の硝化が行なわれる。さらに、この硝化
槽３では、返送汚泥中の微生物によりリン分の除
去が行なわれる。すなわち、この硝化槽３は好気
性状態（DOが高い状態）にあるので、ここに送
られてきた活性汚泥中の微生物は、その性質に基
づき廃水中のリンを前記嫌気性槽１で放出した以
上に取込み、これにより廃水中のリン分が除去さ
れる。
上記のように処理された廃水は、一部前記脱窒
素槽２に返送（循環）され、残部は沈澱槽４に送
られる。この沈澱槽４はホツパー型の容器で、こ
の沈澱槽４では、硝化槽３から送られてきた処理
水中にある活性汚泥を沈澱分離し、上澄液を滅
菌、希釈等の処理を経て最終処理水として放流し
ている。なお、分離された汚泥の一部は、前記嫌
気性槽１への返送汚泥とされ、残部は余剰汚泥と
して別途処理されている。
「発明が解決しようとする問題点」
上記従来の沈澱槽においては、下記のような問
題点があり、その解決が望まれている。
沈澱槽内の沈澱汚泥中のDO濃度は、第２図に
示すように上澄液に対し急激に低くなつており、
しかも経時的に低下し、さらにはDO濃度が零に
なつた後もつづいて酸化還元電位（ORP）値が
低下する。そのため、沈澱汚泥中で硝酸性窒素
（NO3―Ｎ）の脱窒が起つたり、炭酸ガスが放出
されたりして汚泥中に気泡が蓄積してスカムの浮
上が多発し、それに伴なつて処理水（上澄液）の
BOD値、COD値、SS値、トータルリン量（以
下、Ｔ―Ｐ値と称す）などの水質項目が悪化す
る。特にＴ―Ｐ値については、上記のようにDO
値さらにORP値の低下のため、沈澱槽中は強く
嫌気状態となるので、汚泥中の微生物がその性質
によりリンを放出し、その結果、処理水中のリン
濃度が上昇し、水質が悪化してしまう。さらに
は、前記浮上スカムの生体内に取込まれたリン分
に起因して処理水中のＴ―Ｐ値が一層増加してし
まう。
この発明は上記事情に鑑みてなされたもので、
沈澱汚泥内の脱窒や炭酸ガスの発生によるスカム
の浮上および汚泥中からのリン分の溶脱を防止
し、処理水質の改善を図ることのできる沈澱槽を
提供することを目的とするものである。
「問題点を解決するための手段」
この発明に係る曝気沈澱槽は、沈澱槽の内部の
沈澱汚泥内の酸化還元電位を測定する酸化還元電
位（ORP）計または／および同汚泥内の溶存酸
素濃度を測定する溶存酸素濃度計を設けるととも
に、この酸化還元電位計または／および溶存酸素
濃度（DO）計の測定値が所定値を逸脱した時に
槽内の曝気を行なう曝気装置を取付け、さらにこ
の沈澱槽に曝気停止時に槽内の上澄み処理水を放
流する放流装置を取りつけたものである。
「作用」
上記構成よれば、ORP計または／およびDO計
の測定値に基づいて槽内を間歇的に曝気して槽内
の酸化還元電位を所定の値以上に保持し、それに
よつて槽内が嫌気性状態になることを防止するこ
とができ、その結果、汚泥内の脱窒や炭酸ガスに
よるスカムの浮上および汚泥中からのリン分の溶
脱を防止し、処理水質の改善を図ることができ
る。
以下、この発明を実施例により詳しく説明す
る。
「実施例」
第１図はこの発明の一実施例を示すもので、図
中符号５はポツパー型をした沈澱槽を示すもので
ある。この沈澱槽１の中央にはセンターウエル６
が設けられており、同沈澱槽１の一側部には上記
センターウエル６内上部に開口する汚泥混合液導
入用の配管７が取りつけられている。また、この
沈澱槽５内の他側部には、その先端検出部８ａを
沈澱汚泥中に挿入するようにして酸化還元電位
（ORP）計８が取付けられている。これに対し、
沈澱槽５内の一側部には、先端散気口９ａ、曝気
配管９ｂ、電磁弁９ｃおよび送風機９ｄとからな
る曝気装置９が設けられており、前記ORP計８
の測定値に基づいて作動するように構成されてい
る。さらに同沈澱槽５内の他側部には、越流ぜき
１０ａ、配管１０ｂ、および排出ポンプ１０ｃと
からなる放流装置１０が設けられており、排出ポ
ンプ１０ｃが前記ORP計８および送風機９ｄと
に電気的に接続されているタイマ１１に電気的に
接続されている。上記越流ぜき１０ａは水面下
0.5〜３cmに越流端をもつフロート稼動ぜきであ
り、水面の上下に応じて上下し、常に汚泥沈澱後
の上澄水を水面から一定の深さ（0.5〜３cm）で
吸引出来る構造を有している。
次に上記構成の曝気沈澱槽の作用を説明する。
まず、活性汚泥処理の終了した（あるいは途中
の）汚泥混合液を配管７を通してセンターウエル
６内に流入させる（この汚泥混合液の流入は連続
でも間欠でもどちらでもかまわない）。そして
ORP計８の測定値により送風機９ｄおよび排出
ポンプ１０ｃが稼動または停止する。すなわち、
ORP値が所定値（例えば―50mV）より低下した
ら送風機９ｄにより配管９ｂを介して散気口９ａ
から構内に散気する。この曝気により槽内の
ORP値が一定値（一般に前記所定値より30〜
200mV位高くとる）に上昇したら、曝気を停止
し、一定時間（あるいは一定レベルを達するま
で）、静置した後、一定時間あるいは一定レベル
まで上澄水を水面近傍にフロートする越流ぜき１
０ａから排出ポンプ１０ｃにより処理水として放
流する。ここで、レベルにより制御する場合は図
示していないがレベル計が必要であり、時間より
制御する場合はタイマ１１を介することが必要で
ある。また、曝気および／または上澄みの引抜き
の制御を上記電磁弁９ｃ等を介して行なう場合
は、ORP計８（あるいはレベル計）からの電気
信号により時にはタイマ１１を介し、上記電磁弁
１１を作動させて行なうことは言うまでもない。
なお、放流装置１０として越流ぜき１０ａを用い
るかわりにサイフオン構造のものを使用してもよ
い。
上記のように、この曝気沈澱槽によれば、常に
槽内のORP値を所定値以上（槽内を所定以上に
嫌気性状態としない値）に維持することができる
ので、沈澱汚泥からのリンの溶脱は皆無に等しく
なり、処理水質の向上が図れる。さらに、同上の
理由により汚泥内の脱窒や炭酸ガスの発生を抑え
ることができ、スカムが浮上することがなく、
BOD値、COD値、SS値などの水質項目が悪化す
ることがない。
このような本発明の曝気沈澱槽の効果を確認す
るために、従来の沈澱槽との生活排水を対象とし
た処理水質の比較をしたところ、下表のように大
幅な改善が得られたことが判明した。
"Field of Industrial Application" The present invention relates to a settling tank used in the final step of an activated sludge treatment method for organic wastewater. "Prior Art" Conventionally, the treatment of organic wastewater by an activated sludge method involving dephosphorization has been carried out by the steps shown in FIG. That is, the raw wastewater and return sludge are first sent to the anaerobic tank 1. This anaerobic tank 1 is a tank in which the concentration of DO (dissolved oxygen) is kept low.
Microorganisms in the returned sludge sent to the sludge release phosphorus into the wastewater here due to their nature. The microorganisms are then sent to the nitrification tank 3 via the denitrification tank 2 along with the flow of wastewater. In the denitrification tank 2, denitrification bacteria in the activated sludge convert nitrate nitrogen and nitrite nitrogen (NOx-N) contained in the wastewater returned from the nitrification tank 3.
in raw wastewater by using oxygen bound to
As it assimilates BOD components (organic nutrients), NOx
-N nitrogen is released into the atmosphere as nitrogen gas,
This removes nitrogen. This denitrified wastewater is then introduced into the nitrification tank 3. The wastewater sent from this denitrification tank 2 contains organic nitrogen and ammonia nitrogen contained in the raw wastewater, and in the nitrification tank 3, the nitrifying bacteria and nitrifying bacteria in the activated sludge are These nitrogen components are nitrified. Furthermore, in this nitrification tank 3, phosphorus content is removed by microorganisms in the returned sludge. In other words, since this nitrification tank 3 is in an aerobic state (high DO), the microorganisms in the activated sludge sent here release phosphorus in the wastewater in the anaerobic tank 1 based on their properties. This removes phosphorus from the wastewater. A portion of the wastewater treated as described above is returned (circulated) to the denitrification tank 2, and the remainder is sent to the sedimentation tank 4. This sedimentation tank 4 is a hopper type container, and in this sedimentation tank 4, the activated sludge in the treated water sent from the nitrification tank 3 is separated by sedimentation, and the supernatant liquid is sterilized, diluted, etc., and then subjected to final treatment. It is released as water. Note that a part of the separated sludge is returned to the anaerobic tank 1 as sludge, and the remainder is treated separately as surplus sludge. "Problems to be Solved by the Invention" The conventional settling tank described above has the following problems, and it is desired to solve them. As shown in Figure 2, the DO concentration in the settled sludge in the settling tank is rapidly lower than that in the supernatant liquid.
Furthermore, the oxidation-reduction potential (ORP) value continues to decrease over time, and even after the DO concentration reaches zero. As a result, denitrification of nitrate nitrogen (NO 3 -N) occurs in the settled sludge, and carbon dioxide gas is released, causing air bubbles to accumulate in the sludge and scum to float frequently. of treated water (supernatant liquid)
Water quality items such as BOD value, COD value, SS value, and total phosphorus amount (hereinafter referred to as TP value) deteriorate. In particular, regarding the T-P value, DO
Furthermore, due to the decrease in the ORP value, the sedimentation tank becomes strongly anaerobic, so the microorganisms in the sludge release phosphorus due to their nature, resulting in an increase in the phosphorus concentration in the treated water and a deterioration in water quality. Put it away. Furthermore, the TP value in the treated water further increases due to the phosphorus content taken into the living body of the floating scum. This invention was made in view of the above circumstances,
The purpose of the present invention is to provide a settling tank that can improve the quality of treated water by preventing denitrification in settled sludge, surfacing of scum due to generation of carbon dioxide, and leaching of phosphorus from sludge. . "Means for Solving the Problems" The aeration and settling tank according to the present invention includes an oxidation-reduction potential (ORP) meter that measures the redox potential in the settled sludge inside the settling tank, and/or an oxidation-reduction potential (ORP) meter that measures the redox potential in the settled sludge inside the settling tank, and/or an oxidation-reduction potential (ORP) meter that measures the redox potential in the settled sludge inside the settling tank, and In addition to installing a dissolved oxygen concentration meter to measure the concentration, an aeration device is installed to aerate the tank when the measured value of this oxidation-reduction potential meter and/or dissolved oxygen concentration (DO) meter deviates from a predetermined value. The sedimentation tank is equipped with a discharge device that discharges the supernatant treated water inside the tank when aeration is stopped. "Function" According to the above configuration, the inside of the tank is intermittently aerated based on the measured values of the ORP meter and/or DO meter to maintain the oxidation-reduction potential inside the tank at a predetermined value or higher. As a result, it is possible to prevent denitrification in the sludge, the surfacing of scum due to carbon dioxide gas, and the leaching of phosphorus from the sludge, thereby improving the quality of treated water. can. Hereinafter, this invention will be explained in detail with reference to Examples. ``Embodiment'' FIG. 1 shows an embodiment of the present invention, and reference numeral 5 in the figure indicates a popper-shaped settling tank. In the center of this settling tank 1 is a center well 6.
A piping 7 for introducing the sludge mixture, which opens at the upper part of the center well 6, is attached to one side of the settling tank 1. Further, an oxidation-reduction potential (ORP) meter 8 is attached to the other side of the sedimentation tank 5 so that its tip detection portion 8a is inserted into the settled sludge. In contrast,
An aeration device 9 consisting of a tip diffuser 9a, an aeration pipe 9b, a solenoid valve 9c, and a blower 9d is provided on one side of the sedimentation tank 5, and the ORP meter 8
is configured to operate based on the measured value of. Further, on the other side of the sedimentation tank 5, a discharge device 10 is provided which includes an overflow weir 10a, piping 10b, and a discharge pump 10c, and the discharge pump 10c is connected to the ORP total 8 and the blower 9d. The timer 11 is electrically connected to the timer 11 which is electrically connected to the timer 11 . The above overflow weir 10a is below the water surface.
It is a floating weir with an overflow end of 0.5 to 3 cm, which moves up and down according to the rise and fall of the water surface, and has a structure that allows it to always suck up the supernatant water after sludge settling at a constant depth (0.5 to 3 cm) from the water surface. are doing. Next, the operation of the aeration sedimentation tank having the above configuration will be explained. First, the sludge mixture after activated sludge treatment (or in the middle) is made to flow into the center well 6 through the pipe 7 (the sludge mixture may flow continuously or intermittently). and
The blower 9d and the discharge pump 10c are operated or stopped according to the measured value of the ORP meter 8. That is,
When the ORP value falls below a predetermined value (for example, -50mV), the blower 9d sends the air through the air diffuser 9a through the pipe 9b.
diffuse air into the premises. This aeration causes the inside of the tank to
The ORP value is a constant value (generally 30~
When the aeration rises to about 200 mV (higher than 200 mV), stop the aeration, let it stand for a certain period of time (or until it reaches a certain level), and then open the overflow weir 1 to float the supernatant water near the water surface for a certain period of time or until it reaches a certain level.
It is discharged as treated water from 0a by a discharge pump 10c. Here, when controlling based on level, a level meter (not shown) is required, and when controlling based on time, it is necessary to use a timer 11. When controlling aeration and/or supernatant withdrawal via the solenoid valve 9c, etc., the solenoid valve 11 is actuated by an electric signal from the ORP meter 8 (or level meter), sometimes via the timer 11. It goes without saying that we should do it.
In addition, instead of using the overflow weir 10a as the discharge device 10, a device having a siphon structure may be used. As mentioned above, according to this aeration sedimentation tank, the ORP value in the tank can always be maintained at a predetermined value or higher (a value that does not make the tank interior more anaerobic than the predetermined value), so phosphorus from the settled sludge is removed. The leaching of water becomes almost non-existent, and the quality of treated water can be improved. Furthermore, for the same reason as above, denitrification and carbon dioxide generation in the sludge can be suppressed, and scum will not float to the surface.
Water quality items such as BOD value, COD value, and SS value will not deteriorate. In order to confirm the effects of the aeration sedimentation tank of the present invention, we compared the treated water quality of domestic wastewater with a conventional sedimentation tank, and found that a significant improvement was obtained as shown in the table below. There was found.
【表】
なお、上記実施例では、ORP計を設け、その
測定値に基づいて、曝気槽するように構成した
が、このORP計の替りに、または一緒にDO計を
設け、DO値またはDO値とORP値とに基づいて
曝気の制御を行なうようにしても同様の効果を得
ることができる。
また、この発明は、従来例（第２図）に示した
生物脱リンを伴なう活性汚泥法を主に対象とした
もので、それは本発明の曝気沈澱槽が槽内を好気
性状態にすることができるのに対し、脱リンを伴
なう活性汚泥法では下記に述べるように特に嫌気
性状態になりやすいためである。
すなわち、汚泥混合液中の汚泥の酸素吸収速度
は、標準活性汚泥法で10〜15mgO2／ｇMLSS／
hrに対し、生物脱リンを伴なう場合は、好気性槽
での曝気時間および嫌気性槽での滞留時間によつ
ても異なるが大略17〜30mgO2／ｇMLSS／hrと
標準法の1.5〜２倍の酸素吸収速度を有している。
従つて、それだけ沈澱槽でDOが使われる速度が
速く嫌気化しやすい。汚泥混合液中のDO濃度を
2.5mg／とすると、MLSS3000〜4000mg／で
２〜３分で汚泥槽内のDOはほとんどなくなつて
しまう。また、生物脱リンを伴なう場合、SVI値
（汚泥の沈澱しやすさを示す値。小さい程沈澱し
やすい。）が小さく、それだけ沈降性がよくなる
ため沈澱汚泥の密度が高くなり、それだけ沈澱槽
中が（標準活性泥法でSVI80〜150のものが生物
脱リン法では50〜100）嫌気化しやすい。
しかし、この発明の曝気沈澱槽は、生物脱リン
を伴なう活性汚泥法ばかりでなく、曝気槽から直
接沈澱槽に処理水を導く構成の標準的な活性汚泥
法にも有効であり、適用されるべきものである。
「効果」
以上説明したように、この発明に係る曝気沈澱
槽によれば、ORP計または／およびDO計の測定
値に基づいて槽内を間歇的に曝気して槽内の酸化
還元電位または／および溶存酸素濃度を所定の値
以上に保持し、それによつて槽内が嫌気性状態に
なることを防止することができ、その結果、汚泥
内の脱窒や炭酸ガスによるスカムの浮上および汚
泥中からのリン分の溶脱を防止し、処理水質の改
善を図ることができる。[Table] In the above embodiment, an ORP meter was provided and the aeration tank was configured based on the measured value. However, a DO meter was provided instead of or together with the ORP meter to determine the DO value or DO value. A similar effect can be obtained by controlling aeration based on the ORP value and the ORP value. In addition, this invention is mainly aimed at the activated sludge method that involves biological dephosphorization shown in the conventional example (Figure 2), in which the aeration sedimentation tank of the present invention maintains the inside of the tank in an aerobic state. This is because activated sludge methods that involve dephosphorization are particularly susceptible to anaerobic conditions, as described below. In other words, the oxygen absorption rate of sludge in the sludge mixture is 10 to 15 mgO 2 /gMLSS/ in the standard activated sludge method.
hr, when biological dephosphorization is involved, it varies depending on the aeration time in the aerobic tank and residence time in the anaerobic tank, but it is approximately 17 to 30 mgO 2 /gMLSS/hr and 1.5 to 1.5 in the standard method. It has twice the oxygen absorption rate.
Therefore, the rate at which DO is used in the settling tank is faster and it is more likely to become anaerobic. DO concentration in sludge mixture
If it is 2.5mg/, the DO in the sludge tank will almost disappear in 2-3 minutes at MLSS 3000-4000mg/. In addition, when biological dephosphorization is involved, the SVI value (a value that indicates the ease with which sludge settles. The smaller it is, the easier it is to settle.) is small, and the settling property becomes better, so the density of the settled sludge becomes higher, and the settling rate increases accordingly. The inside of the tank tends to become anaerobic (SVI of 80 to 150 in the standard activated mud method is 50 to 100 in the biological dephosphorization method). However, the aeration sedimentation tank of the present invention is effective not only for activated sludge methods that involve biological dephosphorization, but also for standard activated sludge methods in which treated water is directly led from the aeration tank to the settling tank. It should be done. "Effect" As explained above, according to the aeration sedimentation tank according to the present invention, the inside of the tank is intermittently aerated based on the measured values of the ORP meter and/or the DO meter, and the oxidation-reduction potential inside the tank is By maintaining the dissolved oxygen concentration above a predetermined value, it is possible to prevent the inside of the tank from becoming anaerobic.As a result, denitrification in the sludge, scum floating due to carbon dioxide gas, and It is possible to prevent leaching of phosphorus from the water and improve the quality of treated water.
第１図はこの発明の一実施例を示す構成図、第
２図は従来行なわれている有機性廃水の脱リンを
伴なう活性汚泥処理法を示す工程図、第３図は従
来の沈澱槽内の溶存酸素濃度分布を示す図であ
る。
５……沈澱槽、８……酸化還元電位（ORP）
計、９……曝気装置、１０……放流装置。
Figure 1 is a block diagram showing an embodiment of the present invention, Figure 2 is a process diagram showing a conventional activated sludge treatment method involving dephosphorization of organic wastewater, and Figure 3 is a diagram showing a conventional sedimentation method. It is a figure showing dissolved oxygen concentration distribution in a tank. 5...Sedimentation tank, 8...Oxidation-reduction potential (ORP)
Total, 9...aeration device, 10...discharge device.
Claims (1)
る処理水中の活性汚泥の沈殿分離工程に用いられ
る沈殿槽において、この沈殿槽に内部の沈殿汚泥
内の酸化還元電位を測定する酸化還元電位計また
は／および同汚泥内の溶存酸素濃度を測る溶存濃
度計を設けるとともに、この酸化還元電位計また
は／および溶存酸素濃度計の測定値が所定値以下
となつた時に槽内の曝気を行なう曝気装置を取付
け、さらにこの沈殿槽に前記酸化還元電位計また
は／および溶存酸素濃度計の測定値が一定値に上
昇した場合に行なう曝気停止時に槽内の上澄み処
理水を放流する放流装置を取付けたことを特徴と
する曝気沈澱槽。1. In a settling tank used in the sedimentation separation process of activated sludge in treated water, which is the final step of the activated sludge treatment method for organic wastewater, a redox potential meter is installed in this settling tank to measure the redox potential of the settled sludge inside the settling tank. Or/and an aeration device that is equipped with a dissolved concentration meter that measures the dissolved oxygen concentration in the sludge, and that aerates the tank when the measured value of the oxidation-reduction potentiometer or/and dissolved oxygen concentration meter falls below a predetermined value. and a discharge device for discharging the supernatant treated water in the tank when the aeration is stopped when the measured value of the oxidation-reduction potential meter and/or dissolved oxygen concentration meter rises to a certain value. An aerated sedimentation tank featuring:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59173574A JPS6157295A (en) | 1984-08-21 | 1984-08-21 | Aeration sedimentation tank |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59173574A JPS6157295A (en) | 1984-08-21 | 1984-08-21 | Aeration sedimentation tank |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6157295A JPS6157295A (en) | 1986-03-24 |
| JPS6365395B2 true JPS6365395B2 (en) | 1988-12-15 |
Family
ID=15963083
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59173574A Granted JPS6157295A (en) | 1984-08-21 | 1984-08-21 | Aeration sedimentation tank |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6157295A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06142688A (en) * | 1992-11-02 | 1994-05-24 | Daiki Kk | Control method for intermittent aeration in purifying method for sewage of intermittent aeration type |
-
1984
- 1984-08-21 JP JP59173574A patent/JPS6157295A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6157295A (en) | 1986-03-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2002301606B2 (en) | Batch Style Wastewater Treatment Apparatus Using Biological Filtering Process and Wastewater Treatment Method Using The Same | |
| Henze et al. | Rising sludge in secondary settlers due to denitrification | |
| Stegmann et al. | Leachate treatment | |
| US7329349B2 (en) | Water treatment | |
| JPH0655190A (en) | Method for controlling intermittent aeration-type activated sludge technique | |
| KR101537755B1 (en) | Apparatus for treating landfill leachate using aerobic granular sludge and treatment method using thereof | |
| JP3399443B2 (en) | High-load biological treatment method | |
| JP2002119993A (en) | Method and apparatus for treating wastewater | |
| KR100306665B1 (en) | Microbial Reactor and Drainage Treatment Method | |
| JPS6365395B2 (en) | ||
| WO2003101896A1 (en) | Apparatus and method for waste water treatment | |
| Hajsardar et al. | Nitrogen removal from ammonium-rich pharmaceutical wastewater. A comparison between sequencing batch reactor (SBR) and sequencing batch biofilm reactor (SBBR) | |
| KR20230088734A (en) | Method for treating wastewater effluent by densifying sludge in a series of batch reactors | |
| JPH05154496A (en) | Controlling method for operation in anaerobic and aerobic activated sludge treating equipment | |
| JP2004041981A (en) | Organic waste water treatment method and its system | |
| KR100698385B1 (en) | A removal method of organics and nitrogen compounds of wastewater using porosit media a2/o process | |
| JP2759308B2 (en) | Method and apparatus for treating organic wastewater | |
| JPH09174071A (en) | Method for treating organic sewage and apparatus therefor | |
| Kayser | Activated sludge process | |
| JP5801506B1 (en) | Operation method of biological denitrification equipment | |
| JPH091172A (en) | Biological treatment device | |
| JPS60139396A (en) | Removal of phosphorous and nitrogen from bod- containing water | |
| JP2003225693A (en) | Method for drainage treatment | |
| JPH0116559B2 (en) | ||
| JPH08192179A (en) | Device for setting residence time of sludge in activated sludge process |