JPS6321558B2 - - Google Patents
Info
- Publication number
- JPS6321558B2 JPS6321558B2 JP56164549A JP16454981A JPS6321558B2 JP S6321558 B2 JPS6321558 B2 JP S6321558B2 JP 56164549 A JP56164549 A JP 56164549A JP 16454981 A JP16454981 A JP 16454981A JP S6321558 B2 JPS6321558 B2 JP S6321558B2
- Authority
- JP
- Japan
- Prior art keywords
- tank
- denitrification
- sludge
- solid
- liquid separation
- 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
Landscapes
- Physical Water Treatments (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Description
本発明は下水、し尿など有機物及び窒素化合物
を含有する廃水を生物学的に処理する方法及び装
置に関する。
現在、各種廃水から窒素を除去する方法として
は、生物学的方法が最も多く用いられている。こ
の方法を実施する装置は、脱窒槽、硝化槽及び固
液分離槽から構成され、原水を脱窒槽に流入さ
せ、硝化槽内の混合液及び固液分離槽の汚泥を脱
窒槽に返送して脱窒処理を行ない、次に硝化槽に
導入して硝化処理を行ない、硝化混合液を固液分
離槽で固液分離する。固液分離は従来、一般に重
力沈降によりなされているが、汚泥の沈降速度が
遅いため、長い滞留時間を必要とし、濃縮汚泥濃
度も低いという欠点があつた。また、固液分離工
程を空気を用いた加圧浮上により行なう方法も考
えられているが、加圧浮上により酸素含有気泡の
付着した濃縮汚泥が脱窒槽へ返送され、脱窒槽の
嫌気条件が悪化してしまう。脱窒工程は、脱窒菌
の作用により硝酸性窒素（NO3 -）からO2を奪つ
てN2を発生すると共に、有機物を分解する工程
である。従つて、NO3 -以外にフリーなO2が存在
すると、NO3 -は分解せずにフリーなO2が有機物
を消費してしまい、脱窒に必要な有機物が不足
し、脱窒率が低下する。このため、脱窒槽は嫌気
性状態に維持される必要があり、逆に硝化槽では
NH3性Ｎを硝酸性Ｎに変えるために好気性状態
に維持される必要がある。
本発明の目的は、前記従来技術の欠点を解消
し、濃縮汚泥濃度を高め、同時に脱窒槽及び硝化
槽内の汚泥濃度を高くすることができ、脱窒槽で
の有機物の好気的消費を極力抑制しうる生物学的
脱窒素方法及び装置を提供することにある。
この目的は本発明によれば、脱窒素により発生
した窒素ガスを含む気体を加圧し、処理水に溶解
させ、汚泥の浮上濃縮に用いることによつて達成
される。即ち、本発明方法は脱窒工程で生じた気
体並びに固液分離工程で生じた気体を捕集し、該
気体を用いて加圧浮上法による固液分離を行い、
分離した浮上汚泥の少なくとも一部を脱窒工程の
混合液に返送し、残部を余剰汚泥として系外へ取
り出すことを特徴とする。
本発明方法を効果的に実施するには、脱窒槽と
固液分離槽を同一密閉室内に隣設させ、該密閉室
の上部空間に貯溜する気体をパイプにより加圧タ
ンクに導びき、加圧浮上に利用するのが有利であ
る。
次に、本発明の脱窒素方法及び装置を従来例
（第１図、第２図）と対比して第３図に基づいて
説明する。従来の脱窒素処理では、第１図に示す
ように、原水を廃水流入管１から脱窒槽２に導入
し、硝化槽３で硝化を行なつた硝化混合液の一部
を導管４により脱窒槽２へ循環させ、返送汚泥管
５から汚泥を返送し、脱窒処理を行なう。硝化槽
３で硝化された硝化混合液の残部は沈殿槽６に導
入して汚泥の沈降分離を行ない、処理水を放流管
７から排出し、余剰汚泥を排泥管１３から排出さ
せる。硝化槽３内はブロア１１から供給される空
気により好気性状態に維持されている。
前記の沈降槽６の代わりに、浮上分離槽８を設
けた装置を第２図に示す。加圧タンク９では処理
水に空気導入管１２より導入された空気を加圧溶
解させ、この加圧水を浮上分離槽８へ導入する。
浮上分離槽８で放圧により生じた気泡は汚泥に付
着し、汚泥を水面へ浮上させる。浮上分離槽８の
上には汚泥掻出装置１０が設けられていて、汚泥
を掻出し、汚泥の一部は脱窒槽２へ返送され、残
部は排泥管１３より排出される。
このような構成では、脱窒槽２へ返送する汚泥
には酸素含有気泡（空気）が付着しており、脱窒
槽に有機物を消費するフリーのO2が供給されて
しまう。
第３図は本発明の装置の一実施例を示すフロー
シートである。この装置では、１個の密閉室が隔
壁１４により脱窒槽２と浮上分離槽８に区分され
ている。脱窒槽２には、廃水流入管１から原水、
硝化混合液導入管４から硝酸性窒素を含む硝化混
合液及び隔壁１４の上から分離汚泥が導入され
る。脱窒槽２内で脱窒処理された廃水を硝化槽３
中に導入して硝化処理し、次に浮上分離槽８へ導
入する。一方、加圧タンク９には処理水の一部及
び気体導出管１５から脱窒槽及び浮上分離槽の上
部の窒素ガスを含む気体が導入され、ここで処理
水に気体を加圧溶解させ、加圧水とする。この加
圧水及び硝化混合液の一部を浮上分離槽８の下部
から導入し、汚泥を浮上分離する。浮上濃縮され
た汚泥は、一部は掻出装置１０により脱窒槽２へ
導入され、余剰汚泥は排泥管１３から引抜かれ
る。他方、浮上分離槽８の下澄液は処理水として
放流管７から導出される。
第３図に示した構成によれば、加圧浮上に脱窒
槽内で生成した気体を利用し、酸素含有気体を使
用していないので、脱窒槽に有機物を消費するフ
リーなO2が返送汚泥により搬入されず、脱窒槽
内を良好な嫌気性状態に保持しながら汚泥濃度を
高くすることができる。
次に、実施例に基づいて本発明を詳述するが、
本発明はこれに限定されるものではない。
実施例
容量50の脱窒槽、容量25の浮上分離槽及び
容量50の硝化槽を有する第３図の実験装置を用
いて、第１表に水質を示す下水処理場流入水を原
水として処理する。原水は400／日の流量で通
水し、処理水の加圧は2.0〜4.0Kg／cm2、加圧水量
は流入水の30〜300％、循環水量は原水量の400
％、汚泥返送量は原水量の100％、濃縮汚泥濃度
は20000〜25000mg／、硝化・脱窒槽内汚泥濃度
は10000〜12000mg／として実験を行なつた。処
理水の水質を第１表に示す。
比較のため、前記と同じ容量の槽を第１図に示
したように配列して実験したところ、返送汚泥濃
度は8000〜10000mg／となり、槽内汚泥濃度は
4000〜5000mg／程度しか維持できなかつた。そ
のため、原水量を200／日に半減させたところ、
本発明方法と同等の処理水Ｔ―Ｎ濃度（4.1〜6.0
mg／）が得られたが、沈殿池内で処理水中の残
存NOx―Ｎの脱窒が起り、スカムが発生し、処
理水のSS濃度が悪化する。
硝化速度及び脱窒速度は汚泥濃度に比例するの
で、本発明によれば第１図に示す従来法の1/3〜
１／２の容積で処理できる。
更に第２図に示した従来法を本発明方法と同一
条件で実験した。この従来法では、処理水SS濃
度は低く良好であるが、処理水中のＴ―Ｎは多く
残留した。このＴ―Ｎのうち、NOx―Ｎが80〜
90％を占めており、脱窒槽での脱窒が不完全であ
ると考えられたので、脱窒槽流出混合液のNOx
―Ｎ濃度を測定したところ、NOx―Ｎが６〜10
mg／残存していた。また、BODを測定すると、
処理水BOD濃度とほぼ同等であり、空気を用い
た加圧浮上汚泥中の酸素含有気泡によりBODが
好気的に消費されていることが判つた。
本発明によれば、Ｔ―Ｎが著しく低下し、水質
の良好な処理水が得られた。
The present invention relates to a method and apparatus for biologically treating wastewater containing organic matter and nitrogen compounds, such as sewage and human waste. Currently, biological methods are most commonly used to remove nitrogen from various wastewaters. The equipment that implements this method consists of a denitrification tank, a nitrification tank, and a solid-liquid separation tank. Raw water flows into the denitrification tank, and mixed liquid in the nitrification tank and sludge in the solid-liquid separation tank are returned to the denitrification tank. It is subjected to denitrification treatment, then introduced into a nitrification tank for nitrification treatment, and the nitrified mixed liquid is separated into solid and liquid in a solid-liquid separation tank. Conventionally, solid-liquid separation has generally been carried out by gravity sedimentation, but this has the drawbacks of requiring a long residence time and having a low concentration of concentrated sludge due to the slow sedimentation rate of the sludge. In addition, a method has been considered in which the solid-liquid separation process is carried out by pressurized flotation using air, but due to pressurized flotation, concentrated sludge with oxygen-containing bubbles attached is returned to the denitrification tank, worsening the anaerobic conditions in the denitrification tank. Resulting in. The denitrification process is a process in which denitrifying bacteria remove O 2 from nitrate nitrogen (NO 3 − ) to generate N 2 and decompose organic matter. Therefore, if free O 2 exists in addition to NO 3 - , the free O 2 will consume organic matter without decomposing NO 3 - , resulting in a shortage of organic matter necessary for denitrification, and the denitrification rate will decrease. descend. For this reason, denitrification tanks must be maintained in an anaerobic state, whereas nitrification tanks must be maintained in an anaerobic state.
NH3 needs to be maintained in aerobic conditions to convert nitrate N to nitrate N. The purpose of the present invention is to eliminate the drawbacks of the prior art, increase the concentration of concentrated sludge, and at the same time increase the concentration of sludge in the denitrification tank and nitrification tank, and to minimize the aerobic consumption of organic matter in the denitrification tank. An object of the present invention is to provide a method and device for biological denitrification that can be suppressed. This object is achieved according to the invention by pressurizing a gas containing nitrogen gas generated by denitrification, dissolving it in the treated water, and using it for flotation concentration of sludge. That is, the method of the present invention collects the gas generated in the denitrification process and the gas generated in the solid-liquid separation process, and performs solid-liquid separation by pressurized flotation using the gas,
The method is characterized in that at least a portion of the separated floating sludge is returned to the mixed solution for the denitrification process, and the remainder is taken out of the system as surplus sludge. In order to effectively carry out the method of the present invention, the denitrification tank and the solid-liquid separation tank are placed next to each other in the same sealed chamber, and the gas stored in the upper space of the sealed chamber is led to a pressurized tank through a pipe, and pressurized. It is advantageous to use it for levitation. Next, the denitrification method and apparatus of the present invention will be explained based on FIG. 3 in comparison with the conventional example (FIGS. 1 and 2). In conventional denitrification treatment, as shown in Fig. 1, raw water is introduced into a denitrification tank 2 through a wastewater inflow pipe 1, and a part of the nitrification mixture that has been nitrified in a nitrification tank 3 is transferred to the denitrification tank through a conduit 4. 2, and the sludge is returned from the return sludge pipe 5 for denitrification treatment. The remainder of the nitrified mixed liquid nitrified in the nitrification tank 3 is introduced into a settling tank 6 to perform sedimentation and separation of sludge, the treated water is discharged from the discharge pipe 7, and the excess sludge is discharged from the sludge pipe 13. The inside of the nitrification tank 3 is maintained in an aerobic state by air supplied from a blower 11. FIG. 2 shows an apparatus in which a flotation separation tank 8 is provided in place of the sedimentation tank 6 described above. In the pressurized tank 9, the air introduced through the air introduction pipe 12 is dissolved in the treated water under pressure, and this pressurized water is introduced into the flotation separation tank 8.
Bubbles generated by pressure release in the flotation separation tank 8 adhere to the sludge and float the sludge to the water surface. A sludge scraping device 10 is provided above the flotation separation tank 8 to scrape out the sludge, part of the sludge is returned to the denitrification tank 2, and the remaining part is discharged from the sludge pipe 13. In such a configuration, oxygen-containing bubbles (air) are attached to the sludge returned to the denitrification tank 2, and free O 2 that consumes organic matter is supplied to the denitrification tank. FIG. 3 is a flow sheet showing one embodiment of the apparatus of the present invention. In this device, one sealed chamber is divided into a denitrification tank 2 and a flotation separation tank 8 by a partition wall 14. The denitrification tank 2 receives raw water from the wastewater inflow pipe 1,
The nitrification mixture containing nitrate nitrogen is introduced from the nitrification mixture introduction pipe 4 and the separated sludge is introduced from above the partition wall 14 . The wastewater that has been denitrified in the denitrification tank 2 is transferred to the nitrification tank 3.
It is introduced into the tank for nitrification treatment, and then introduced into the flotation separation tank 8. On the other hand, a part of the treated water and a gas containing nitrogen gas from the upper part of the denitrification tank and flotation tank are introduced from the gas outlet pipe 15 into the pressurized tank 9, where the gas is dissolved in the treated water under pressure, and the pressurized water shall be. A portion of this pressurized water and nitrification mixture is introduced from the lower part of the flotation tank 8, and the sludge is floated and separated. Part of the floated and concentrated sludge is introduced into the denitrification tank 2 by the scraping device 10, and excess sludge is pulled out from the sludge pipe 13. On the other hand, the lower liquid in the flotation separation tank 8 is led out from the discharge pipe 7 as treated water. According to the configuration shown in Figure 3, the gas generated in the denitrification tank is used for pressurized flotation and no oxygen-containing gas is used, so free O 2 that consumes organic matter is returned to the denitrification tank as sludge. Therefore, the sludge concentration can be increased while maintaining a good anaerobic condition inside the denitrification tank. Next, the present invention will be explained in detail based on examples.
The present invention is not limited to this. Example Using the experimental apparatus shown in FIG. 3, which has a denitrification tank with a capacity of 50, a flotation tank with a capacity of 25, and a nitrification tank with a capacity of 50, inflow water from a sewage treatment plant whose water quality is shown in Table 1 is treated as raw water. Raw water flows at a flow rate of 400 kg/day, the pressurization of treated water is 2.0 to 4.0 Kg/cm 2 , the pressurized water volume is 30 to 300% of the inflow water, and the circulating water volume is 400% of the raw water volume.
%, the sludge return amount was 100% of the raw water amount, the concentrated sludge concentration was 20,000 to 25,000 mg/, and the sludge concentration in the nitrification/denitrification tank was 10,000 to 12,000 mg/. The quality of the treated water is shown in Table 1. For comparison, when we conducted an experiment with tanks of the same capacity as above arranged as shown in Figure 1, the returned sludge concentration was 8000 to 10000 mg/, and the sludge concentration in the tank was
I was only able to maintain around 4000-5000mg/. Therefore, when we reduced the amount of raw water by half to 200/day,
Treated water T-N concentration equivalent to the method of the present invention (4.1 to 6.0
mg/), but denitrification of residual NO x -N in the treated water occurs in the sedimentation tank, generating scum and worsening the SS concentration in the treated water. Since the nitrification rate and denitrification rate are proportional to the sludge concentration, according to the present invention, the rate of nitrification is 1/3 to 1/3 of the conventional method shown in Figure 1.
Can be processed with 1/2 the volume. Further, the conventional method shown in FIG. 2 was tested under the same conditions as the method of the present invention. In this conventional method, the SS concentration in the treated water was low and good, but a large amount of TN remained in the treated water. Of this T-N, NO x -N is 80~
Since the denitrification in the denitrification tank was considered to be incomplete, the NO x
- When the N concentration was measured, NO x -N was 6 to 10
mg/remained. Also, when measuring BOD,
The BOD concentration was almost the same as that of the treated water, indicating that BOD was consumed aerobically by oxygen-containing bubbles in the sludge floated under pressure using air. According to the present invention, TN was significantly reduced and treated water with good water quality was obtained.
【表】
以上詳述したように、本発明により脱窒槽と浮
上分離槽を同一密閉室内に隣設させ、脱窒槽及び
浮上分離槽上部の脱窒素により生じた窒素ガスを
含む気体を加圧して浮上分離に用いることによ
り、脱窒槽においてBODを好気的に分解するこ
となく、有効に脱窒に利用することができ、かつ
汚泥を高濃度に保持することができ、小容量の反
応槽で安定した処理を行なうことが可能になる。[Table] As detailed above, according to the present invention, a denitrification tank and a flotation tank are placed next to each other in the same sealed chamber, and the gas containing nitrogen gas generated by denitrification in the upper part of the denitrification tank and flotation tank is pressurized. By using it for flotation separation, BOD can be effectively used for denitrification without being aerobically decomposed in the denitrification tank, and sludge can be maintained at a high concentration, making it possible to use it in a small-capacity reaction tank. It becomes possible to perform stable processing.
第１図及び第２図は従来法のフローシート、第
３図は本発明のフローシートである。
符号の説明 ２…脱窒槽、３…硝化槽、６…沈
殿池、８…浮上分離槽、９…加圧タンク、１２…
空気導入管、１５…気体導出管。
1 and 2 are flow sheets of the conventional method, and FIG. 3 is a flow sheet of the present invention. Explanation of symbols 2... Denitrification tank, 3... Nitrification tank, 6... Sedimentation tank, 8... Flotation tank, 9... Pressure tank, 12...
Air introduction pipe, 15... gas discharge pipe.
Claims (1)
及び脱窒工程に導入し、脱窒工程で生じた気体並
びに固液分離工程で生じた気体を捕集し、該気体
を用いて加圧浮上法による固液分離を行い、分離
した浮上汚泥の少なくとも一部を脱窒工程の混合
液に返送し、残部を余剰汚泥として系外へ取り出
すことを特徴とする廃水の生物学的脱窒素方法。 ２ 脱窒槽、硝化槽、固液分離槽及び固液分離槽
へ加圧水を供給する加圧タンクから成る廃水の生
物学的脱窒素装置において、脱窒槽と固液分離槽
を同一密閉室内に隣接させ、該密閉室の上部空間
に貯溜する気体の導出管を加圧タンクと接続した
ことを特徴とする廃水の生物学的脱窒素装置。[Claims] 1. Wastewater containing nitrogen compounds and organic matter is introduced into a nitrification process and a denitrification process, the gas generated in the denitrification process and the gas generated in the solid-liquid separation process are collected, and the gas is used to A biological wastewater treatment method characterized by performing solid-liquid separation using a pressure flotation method, returning at least a portion of the separated floated sludge to the mixed solution for the denitrification process, and taking the remainder out of the system as surplus sludge. Denitrification methods. 2. In a wastewater biological denitrification system consisting of a denitrification tank, a nitrification tank, a solid-liquid separation tank, and a pressurized tank that supplies pressurized water to the solid-liquid separation tank, the denitrification tank and the solid-liquid separation tank are placed adjacent to each other in the same sealed room. A biological denitrification device for wastewater, characterized in that a discharge pipe for gas stored in the upper space of the sealed chamber is connected to a pressurized tank.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16454981A JPS5864198A (en) | 1981-10-15 | 1981-10-15 | Method and apparatus for biologically denitrifying waste water |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16454981A JPS5864198A (en) | 1981-10-15 | 1981-10-15 | Method and apparatus for biologically denitrifying waste water |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5864198A JPS5864198A (en) | 1983-04-16 |
| JPS6321558B2 true JPS6321558B2 (en) | 1988-05-07 |
Family
ID=15795264
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16454981A Granted JPS5864198A (en) | 1981-10-15 | 1981-10-15 | Method and apparatus for biologically denitrifying waste water |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5864198A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6887426B2 (en) | 1986-08-13 | 2005-05-03 | Roger Phillips | Reagents test strip adapted for receiving an unmeasured sample while in use in an apparatus |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002028688A (en) * | 2000-07-18 | 2002-01-29 | Maezawa Ind Inc | Wastewater treatment equipment |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5527052A (en) * | 1978-08-15 | 1980-02-26 | Ebara Infilco Co Ltd | Sludge floatation and concentration |
| JPS5527062A (en) * | 1978-08-16 | 1980-02-26 | Ebara Infilco Co Ltd | Concentration of sludge |
-
1981
- 1981-10-15 JP JP16454981A patent/JPS5864198A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6887426B2 (en) | 1986-08-13 | 2005-05-03 | Roger Phillips | Reagents test strip adapted for receiving an unmeasured sample while in use in an apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5864198A (en) | 1983-04-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0979803B1 (en) | Water treatment system based on denitrification | |
| JP2000015288A (en) | Wastewater treatment method and apparatus | |
| JPH0790230B2 (en) | Biological wastewater purification method | |
| MY122110A (en) | Apparatus and method for treating sewage and wastewater biologically. | |
| GB1603299A (en) | Process and apparatus for the aerobic biological treatment of waste water | |
| GB2113667A (en) | Activated-sludge process for wastewater treatment | |
| Hwang et al. | Enhanced nitrogen removal from sludge reject water by methanol addition using sequencing batch biofilm reactor | |
| JPS54108461A (en) | Method of denitrifying high concentration nitrogen contained waste water | |
| JPS6321558B2 (en) | ||
| JPH0839100A (en) | Simultaneous treatment of kitchen wastewater and kitchen waste | |
| Charmot‐Charbonnel et al. | Nitrification of high strength ammonium wastewater in an aerated submerged fixed bed | |
| JPH1110193A (en) | Method and apparatus for nitrification denitrification reaction with carrier | |
| JP4747567B2 (en) | Nitrogen-containing wastewater treatment method and treatment equipment | |
| JP3355121B2 (en) | Organic wastewater treatment method | |
| KR100544367B1 (en) | Water treatment equipment | |
| JP4581174B2 (en) | Biological treatment method | |
| JPS5586586A (en) | Treating method of sewage | |
| JPS643557B2 (en) | ||
| JPS6350078B2 (en) | ||
| JPS6244998B2 (en) | ||
| JPS6113112Y2 (en) | ||
| RU9456U1 (en) | BIOLOGICAL WASTE WATER TREATMENT PLANT | |
| Landine et al. | Anaerobic fermentation-filtration of potato processing wastewater | |
| JPH0133237B2 (en) | ||
| KR19990083922A (en) | Processing mothod and processing system for excretions of animals |