JPS6260157B2 - - Google Patents
Info
- Publication number
- JPS6260157B2 JPS6260157B2 JP12099079A JP12099079A JPS6260157B2 JP S6260157 B2 JPS6260157 B2 JP S6260157B2 JP 12099079 A JP12099079 A JP 12099079A JP 12099079 A JP12099079 A JP 12099079A JP S6260157 B2 JPS6260157 B2 JP S6260157B2
- Authority
- JP
- Japan
- Prior art keywords
- denitrification
- paragraph
- medium
- biological
- denitrifying bacteria
- 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
- 238000000034 method Methods 0.000 claims description 89
- 241000894006 Bacteria Species 0.000 claims description 69
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 28
- 229910052799 carbon Inorganic materials 0.000 claims description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 21
- 239000002351 wastewater Substances 0.000 claims description 19
- 238000006243 chemical reaction Methods 0.000 claims description 16
- 239000006228 supernatant Substances 0.000 claims description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- 239000004576 sand Substances 0.000 claims description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 230000003247 decreasing effect Effects 0.000 claims description 3
- 239000008187 granular material Substances 0.000 claims 1
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- 239000003638 chemical reducing agent Substances 0.000 description 3
- 230000001546 nitrifying effect Effects 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 238000004065 wastewater treatment Methods 0.000 description 3
- 239000000470 constituent Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000029087 digestion Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910017464 nitrogen compound Inorganic materials 0.000 description 2
- 150000002830 nitrogen compounds Chemical class 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- -1 NH4 Chemical class 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- RHZUVFJBSILHOK-UHFFFAOYSA-N anthracen-1-ylmethanolate Chemical compound C1=CC=C2C=C3C(C[O-])=CC=CC3=CC2=C1 RHZUVFJBSILHOK-UHFFFAOYSA-N 0.000 description 1
- 239000003830 anthracite Substances 0.000 description 1
- 230000001580 bacterial effect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 238000012958 reprocessing Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- 239000010457 zeolite Substances 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
- Biological Treatment Of Waste Water (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Description
本発明は脱窒工程の媒体上に付着した脱窒菌を
利用して脱窒する廃水の生物学的脱窒法におい
て、媒体上の脱窒菌の量を合理的かつ経済的に制
御する方法に関するものである。
一般に生物学的脱窒法は活性汚泥法と活性炭、
砂などの媒体に微生物を付着して利用する生物固
定床法に大別されるが、設置面積に制限のある処
理施設では、硝化菌、脱窒菌を純粋かつ高濃度に
維持でき、しかも装置の縮少が可能な固定床法が
実用化されている。この固定床法の脱窒処理は通
常廃水中の窒素化合物、例えばNH4を硝化工程で
NO2あるいはNO3（以下NOxとする）に硝化した
のち、脱窒菌が付着した媒体によつて固定層ある
いは流動層の形成されている脱窒工程でNOxをN2
ガスにまで還元分解（脱窒）するものである。こ
の方法で発生する余剰菌の処理は、媒体を再利用
するため、媒体を脱窒工程より引抜いた後媒体に
付着した脱窒菌と媒体とを分離し、媒体は脱窒工
程に返送し、脱窒菌は脱水、乾燥、焼却される
が、この方法は、媒体に対する脱窒菌の付着が強
力なため剥離に大きなエネルギーを必要とするこ
と、剥離された脱窒菌は純粋培養化されているの
で極めて脱水性が悪いこと等の欠点がある。また
嫌気的消化法を利用して、媒体上の脱窒菌を可溶
化し、媒体より分離する方法もあるが、脱窒菌の
可溶化に長時間を要するうえ、消化脱離液の再処
理が必要であるという欠点を有する。このような
従来の余剰菌の処理法は操作が煩雑であるうえ前
記の如き欠点があり当業界にとつて憂慮されてい
る問題であつた。とりわけ余剰脱窒菌の処理法の
改良が大きな問題となつているが、これは、この
方法で利用する硝化菌の増殖量は0.1増殖菌量／
NH4-N（ｇ／ｇ）であるのに対し、脱窒菌の増殖
量は使用する有機炭素源の種類によつても異なる
が、菌体収率の小さいメタノール資化性脱窒菌で
も0.4増殖菌量／NO3-N（ｇ／ｇ）で、除去する
同一窒素量あたり硝化菌の４倍量にも達するため
である。
本発明は、これら従来法の欠点を解消するもの
であり、有機炭素源による脱窒反応（外呼吸型脱
窒反応）で媒体上に増殖した脱窒菌を有機炭素源
無添加、即ち脱窒菌の構成成分自体を還元剤とす
る脱窒反応（内呼吸型脱窒反応）によつて媒体上
に増殖した余剰脱窒菌を減少せしめたのち、再び
有機炭素源による脱窒反応で脱窒菌を増殖すると
いう方法を複数の脱窒工程を利用し、工程全体の
脱窒菌量が適宜の所定量に保持されるよう工夫さ
れた生物学的脱窒法であつて、脱窒菌を脱窒工程
から引抜くことも、脱窒菌を媒体より分離するこ
とも不要な、極めて容易で経済的な余剰脱窒菌の
処理・処分が可能な廃水の生物学的脱窒法の提供
を目的とするものである。
次に本発明の実施態様を第１図に基づいて説明
する。NH3を含有する廃水１は硝化工程２でNOx
に硝化され硝化水３となつたのち、一方窒素化合
物としてはNOxのみを含有しNH3は含まない廃水
１′は直接有機炭素源５、例えばメタノールの注
入なしに脱窒工程Ａに流入しNOxの一部が脱窒さ
れ媒体（脱窒菌）層と層分離して上澄水４とな
る。この上澄水４は有機炭素源５とともに脱窒工
程Ｂに流入し、有機炭素源５による脱窒反応で脱
窒が完了し上澄水のかたちで処理水８となつて放
流される。前記脱窒工程Ａでは脱窒菌自体を還元
剤とする内呼吸型脱窒反応により脱窒菌は次第に
減少し、脱窒工程Ｂでは有機炭素源５による脱窒
反応で脱窒菌は増殖する。内呼吸型の脱窒速度は
有機炭素源５による脱窒速度のおおよそ1/5〜1/1
０である。従つて、脱窒工程Ａ，Ｂの脱窒菌量が
同じであれば、脱窒工程Ａで流入するNOxの10〜
20％を除去し、脱窒工程Ｂで残留する80〜90％の
NOxを除去するようにすれば効率的な脱窒処理を
することができる。一方脱窒工程Ａ，Ｂの脱窒菌
がそれぞれ過剰に減少、増加する前に、脱窒工程
Ａの媒体は返送ライン６、脱窒工程Ｂの媒体は移
送ライン７を経由してそれぞれ脱窒工程Ｂ，Ａに
手動あるいは自動的に同時にあるいは別々に返
送、移送することによつて脱窒工程Ａ，Ｂの脱窒
菌量をそれぞれ概略一定量に、従つて脱窒工程全
体としての脱窒菌量を適宜な所定量に保持するこ
とができる。
脱窒工程の脱窒菌量および脱窒量の調節は、脱
窒工程Ａ、脱窒工程Ｂの配分と有機炭素源注入量
の増減を同時にあるいはそれぞれ単独に調整、制
御することによつて行うことができる。例えば、
脱窒工程Ｂの脱窒菌の増殖量が脱窒工程Ａの減少
量をうわまわる場合には、脱窒工程Ａの容積を大
きくするか脱窒工程Ａを複数にして、脱窒工程Ａ
に保持する脱窒菌量を増加しかつ脱窒工程Ａに流
入するNOx―Ｎ量を増加して脱窒工程Ａ，Ｂの脱
窒菌量を適宜な所定量保持すればよく、逆に脱窒
工程Ｂの増殖量が脱窒工程Ａの減少量を下まわる
場合には脱窒工程Ｂの容積を大きくするか脱窒工
程Ｂを複数にすればよい。このように脱窒工程
Ａ，Ｂをそれぞれ複数にしたほうが、負荷変動に
対応して有機炭素源の注入量、脱窒菌の保持量を
調節するうえで好ましい。増殖した脱窒菌の減少
は、有機炭素源の注入を完全に停止せずとも、脱
窒菌の増殖に不足な量にまで注入量を低下するこ
とによつて行うこともできる。この場合、有機炭
素源無注入より脱窒速度は大きくなり、脱窒菌の
減少量は少なくなる。従つて脱窒菌の減少が増加
を上まわる場合には脱窒工程(A)にも有機炭素源５
を少量注入して脱窒菌量を制御すればよい。
図示例は前段の脱窒工程Ａから後段の脱窒工程
Ｂへの媒体の返送が、脱窒工程Ａからの流出水即
ち媒体（脱窒菌）層と層分離した上澄水を同伴し
ない状態で行なわれる場合であるが、該返送を上
澄水を同伴した状態で行なつてもよい。
上記の有機炭素源としては、使用する脱窒菌の
菌種を考慮して選定する必要があり、メタノー
ル、エタノール、アセトン、酢酸などが使用でき
るが、資化性、扱い易さ、経済性などの点からメ
タノールが好ましい。また脱窒菌の媒体として
は、形状が粒状又はフレーク状でポンプなどによ
る配管を通しての移送が容易な寸法の砂、アンス
ラサイト、ゼオライト、鉱滓、等又は磁製、ガラ
ス製、プラスチツクス製等の材料を使用すること
ができるが、砂が好ましい。
また、脱窒工程Ａ，Ｂの脱窒反応装置としては
槽型又は塔型のものが使用できるが特に塔型の装
置が好ましく、媒体の返送、移送の制御を容易
に、経済的に行なうことができる。
前記媒体の移送又は返送の要領としては、次の
ような方法をとることができる。まず脱窒工程Ｂ
から脱窒工程Ａへの移送は、脱窒工程Ｂにおける
媒体の層高を監視し、層高が増大して媒体が溢流
し始める時点即ち、上澄水中に媒体が同伴される
直前又は同伴され始めた時点で移送を開始するこ
ともできるが、脱窒工程Ｂにおける媒体の層高が
所定の高さまで増大した時点で移送を開始する方
法が好ましい。一方、脱窒工程Ａから脱窒工程Ｂ
への返送は同様にして、脱窒工程Ａにおける媒体
の層高が所定の高さまで低下した時点又は媒体上
の脱窒菌量が所定の状態まで減少した時点で返送
を開始する方法が望ましい。
以上のような肉眼による手動的移送の他に、長
期間無人運転をする場合には、次のような自動移
送、返送を行うのがよい。例えば脱窒工程Ａ，Ｂ
の媒体の層高（固液界面）の増減を光の透過率あ
るいは他の手段による界面計を用いて検知し、移
送、返送する方法、タイマで媒体移送（返送）時
間を設定し、間歇的に移送する方法などである。
後者の方法では設定時間に対する媒体の層高の増
減状況を知ることによつて、経験的に最適な移送
（返送）時間を設定すればよい。
次に本発明の一実施例について示す。
前記脱窒工程Ａ，Ｂの装置として流動層式脱窒
塔をそれぞれ１本づつ、また有機炭素源としてメ
タノールを、流動層の媒体として砂を使用した。
これら脱窒塔は、いずれも円筒形カラムで直径
200mm、高さ1600mm、有効容積は50.2の実験装
置である。
上記装置にNO3-N濃度30mg／の人工硝化水
（脱塩素水道水にNaNO3を添加、調製したもの）
を2000／日の流量で通水して処理した。なお流
動層の脱窒菌量については流動層層高を肉眼監視
した増減を調べ、処理全体としての脱窒菌量を所
定範囲の量に保持するようメタノールの注入量、
媒体の上記２塔間の移送、返送の時期と量を調節
した。
通水開始時の流動層層高は工程Ａの脱窒塔（第
１塔）では1200mm、工程Ｂの脱窒塔（第２塔）で
は600mmであり、又この時の流動層脱窒菌濃度は
両塔とも21500mg／であつた。
以上の実験装置、条件から得られた結果は表―
１のとおりである。表―１に示すように第１塔に
はメタノールは全く注入する必要がなく、処理装
置全体の脱窒菌量即ち流動層層高の合計は約1800
mmでほぼ一定量に保持されている。かくて処理水
のNO3-N濃度は充分低下したこと、従つて本発明
の処理方法によつて極めて大なる効果が得られる
ことがわかる。
The present invention relates to a method for rationally and economically controlling the amount of denitrifying bacteria on a medium in a biological denitrification method for wastewater that utilizes denitrifying bacteria attached to the medium in the denitrification process. be. Generally, biological denitrification methods include activated sludge method, activated carbon,
It is broadly divided into biological fixed bed methods, which use microorganisms attached to media such as sand, but in treatment facilities with limited installation space, it is possible to maintain nitrifying bacteria and denitrifying bacteria at a pure and high concentration, and it is easy to use equipment. A fixed bed method that can be reduced has been put into practical use. This fixed bed denitrification process usually removes nitrogen compounds, such as NH4 , from wastewater through the nitrification process.
After nitrification to NO 2 or NO 3 (hereinafter referred to as NO x ), NO
It is reduced and decomposed (denitrified) into gas. In order to reuse the medium, the surplus bacteria generated in this method is removed from the denitrification process, the denitrifying bacteria attached to the medium are separated from the medium, and the medium is returned to the denitrification process. Nitrogen bacteria are dehydrated, dried, and incinerated, but this method requires a large amount of energy to peel off because the denitrifier bacteria adhere strongly to the medium, and because the detached denitrifier bacteria is a pure culture, it is extremely dehydrated. There are drawbacks such as bad sex. There is also a method that uses anaerobic digestion to solubilize denitrifying bacteria on the medium and separate it from the medium, but it takes a long time to solubilize the denitrifying bacteria and requires reprocessing of the digestion solution. It has the disadvantage of being Such conventional methods for treating surplus bacteria are complicated in operation and have the above-mentioned drawbacks, which are problems that are of concern to the industry. In particular, improving the treatment method for surplus denitrifying bacteria has become a major issue, since the growth rate of the nitrifying bacteria used in this method is 0.1 amount of growing bacteria/
NH 4-N (g/g), the growth rate of denitrifying bacteria varies depending on the type of organic carbon source used, but even methanol-assimilating denitrifying bacteria with a low bacterial cell yield can grow by 0.4. This is because the amount of bacteria/NO 3-N (g/g) reaches four times the amount of nitrifying bacteria for the same amount of nitrogen removed. The present invention solves the drawbacks of these conventional methods, and the denitrifying bacteria grown on the medium by the denitrification reaction using an organic carbon source (exo-breathing denitrification reaction) are treated without the addition of an organic carbon source, that is, by denitrifying bacteria. After reducing excess denitrifying bacteria that have grown on the medium through a denitrification reaction using the constituent components themselves as reducing agents (endo-respiration type denitrification reaction), the denitrifying bacteria are grown again through a denitrification reaction using an organic carbon source. This method is a biological denitrification method devised to maintain the amount of denitrifying bacteria in an appropriate predetermined amount in the entire process by using multiple denitrifying processes. The purpose of the present invention is to provide a biological denitrification method for wastewater that does not require separation of denitrifying bacteria from a medium, and that allows extremely easy and economical treatment and disposal of surplus denitrifying bacteria. Next, an embodiment of the present invention will be described based on FIG. Wastewater 1 containing NH 3 is converted to NO x in the nitrification process 2.
After being nitrified into nitrified water 3, the wastewater 1' containing only NO x and no NH 3 as a nitrogen compound directly flows into the denitrification step A without injection of an organic carbon source 5, for example, methanol. A portion of the NO x is denitrified and separated from the medium (denitrifying bacteria) layer to form supernatant water 4. This supernatant water 4 flows into the denitrification process B together with the organic carbon source 5, and denitrification is completed by the denitrification reaction by the organic carbon source 5, and the treated water 8 is discharged in the form of supernatant water. In the denitrification step A, the denitrifying bacteria gradually decrease through an endorespiratory denitrification reaction using the denitrifying bacteria itself as a reducing agent, and in the denitrifying step B, the denitrifying bacteria proliferate through the denitrification reaction using the organic carbon source 5. The denitrification rate of endorespiration type is approximately 1/5 to 1/1 of the denitrification rate by organic carbon source 5.
It is 0. Therefore, if the amount of denitrifying bacteria in denitrification processes A and B is the same, the amount of NO x flowing in in denitrification process A will be 10~
20% is removed and 80-90% remaining in denitrification process B.
Efficient denitrification treatment can be performed by removing NO x . On the other hand, before the denitrifying bacteria in denitrification processes A and B excessively decrease and increase, respectively, the medium of denitrification process A is passed through the return line 6, and the medium of denitrification process B is passed through the transfer line 7, respectively, to the denitrification process. By manually or automatically returning or transferring the bacteria to B and A simultaneously or separately, the amount of denitrifying bacteria in the denitrification processes A and B can be kept approximately constant, and therefore the amount of denitrifying bacteria in the denitrification process as a whole can be kept at approximately constant amounts. It can be maintained at an appropriate predetermined amount. The amount of denitrifying bacteria and the amount of denitrification in the denitrification process can be adjusted by adjusting and controlling the distribution of denitrification process A and denitrification process B and the increase/decrease of the amount of organic carbon source injection at the same time or individually. Can be done. for example,
If the amount of growth of denitrifying bacteria in denitrification step B exceeds the amount of decrease in denitrification step A, increase the volume of denitrification step A or use multiple denitrification steps A to increase denitrification step A.
It is sufficient to increase the amount of denitrifying bacteria held in the denitrifying process and increase the amount of NO If the amount of growth in step B is less than the amount of decrease in denitrification step A, the volume of denitrification step B may be increased or a plurality of denitrification steps B may be performed. In this way, it is preferable to perform a plurality of denitrification processes A and B in order to adjust the amount of organic carbon source to be injected and the amount of denitrifying bacteria retained in response to load fluctuations. The growth of denitrifying bacteria can be reduced by reducing the injection amount to an amount insufficient for the growth of denitrifying bacteria, without completely stopping the injection of the organic carbon source. In this case, the denitrification rate will be higher than when no organic carbon source is injected, and the amount of denitrifying bacteria will decrease. Therefore, if the decrease in denitrifying bacteria exceeds the increase, organic carbon source 5 is also added to the denitrification process (A).
The amount of denitrifying bacteria can be controlled by injecting a small amount of In the illustrated example, the medium is returned from the previous denitrification process A to the subsequent denitrification process B without entraining the effluent water from the denitrification process A, that is, the medium (denitrifying bacteria) layer and the supernatant water separated into layers. However, the return may be carried out with supernatant water. The above organic carbon source must be selected taking into consideration the type of denitrifying bacteria used, and methanol, ethanol, acetone, acetic acid, etc. can be used, but From this point of view, methanol is preferred. In addition, as a medium for denitrifying bacteria, materials such as sand, anthracite, zeolite, slag, etc. that are granular or flaky and of a size that can be easily transferred through piping with a pump, etc., or materials made of porcelain, glass, plastic, etc. can be used, but sand is preferred. Further, as the denitrification reactor for the denitrification steps A and B, tank type or tower type devices can be used, but a tower type device is particularly preferable, since the return and transfer of the medium can be easily and economically controlled. Can be done. The following methods can be used to transport or return the medium. First, denitrification process B
The layer height of the medium in the denitrification step B is monitored, and the transfer from the medium to the denitrification step A is carried out at the point when the layer height increases and the medium begins to overflow, that is, immediately before the medium is entrained in the supernatant water, or when the medium is entrained in the supernatant water. Although it is possible to start the transfer at the same time, it is preferable to start the transfer when the layer height of the medium in the denitrification step B increases to a predetermined height. On the other hand, from denitrification process A to denitrification process B
Similarly, it is preferable to start the return at the time when the layer height of the medium in the denitrification step A has decreased to a predetermined height or when the amount of denitrifying bacteria on the medium has decreased to a predetermined state. In addition to the manual transfer using the naked eye as described above, if unmanned operation is to be performed for a long period of time, it is recommended to perform automatic transfer and return as described below. For example, denitrification processes A and B
A method in which the increase or decrease in the layer height (solid-liquid interface) of the medium is detected using an interface meter using light transmittance or other means, and the medium is transferred or returned. For example, how to transfer the data to
In the latter method, the optimal transfer (return) time may be set empirically by knowing the increase/decrease situation in the layer height of the medium with respect to the set time. Next, an embodiment of the present invention will be described. One fluidized bed denitrification tower was used as the equipment for the denitrification steps A and B, methanol was used as the organic carbon source, and sand was used as the fluidized bed medium.
These denitrification towers are all cylindrical columns with a diameter of
The experimental device is 200 mm long, 1600 mm high, and has an effective volume of 50.2 mm. Artificial nitrified water (prepared by adding NaNO 3 to dechlorinated tap water) with a NO 3-N concentration of 30 mg/in the above device
was treated by passing water through it at a flow rate of 2000/day. Regarding the amount of denitrifying bacteria in the fluidized bed, increase and decrease in the height of the fluidized bed was visually monitored, and the amount of methanol to be injected and
The timing and amount of medium transfer and return between the two towers were adjusted. The height of the fluidized bed at the start of water flow is 1200 mm in the denitrification tower (first tower) in process A and 600 mm in the denitrification tower (second tower) in process B, and the concentration of denitrifying bacteria in the fluidized bed at this time is The concentration in both towers was 21,500 mg/. The results obtained from the above experimental equipment and conditions are shown in the table below.
As per 1. As shown in Table 1, there is no need to inject any methanol into the first column, and the amount of denitrifying bacteria in the entire treatment equipment, that is, the total height of the fluidized bed, is approximately 1800.
It is maintained at an almost constant amount in mm. It can thus be seen that the NO 3 -N concentration in the treated water has been sufficiently reduced, and that the treatment method of the present invention can provide extremely great effects.
【表】
以上のように本発明によれば、有機炭素源によ
る脱窒反応（外呼吸型脱窒反応）で媒体上に増殖
した脱窒菌を有機炭素源無添加、即ち脱窒菌の構
成成分自体を還元剤とする脱窒反応（内呼吸型脱
窒反応）によつて媒体上に増殖した余剰脱窒菌を
減少せしめたのち、再び有機炭素源による脱窒反
応で脱窒菌を増殖するという方法を複数の脱窒工
程を利用し、工程全体の脱窒菌量が適宜の所定量
に保持されるようにしたことにより、廃水処理工
程全体としての脱窒菌量が簡単且つ経済的に適宜
の所定量に保持されるので、該廃水処理工程の系
外へ余剰脱窒菌を排出する必要がなくなる結果、
従来のような必要とされていた脱窒菌の、媒体か
らの分離あるいは該分離後の脱窒菌の脱水、乾燥
等の処理設備及び処理費用が不要となると共に余
剰脱窒菌の処分が容易経済的にできるし、前記脱
窒菌量を適宜の所定量に保持する手段として内呼
吸型脱窒反応を利用しているので、該反応に必要
な脱窒菌量に相当する量の有機炭素源が節約で
き、極めて経済的な廃水処理が可能となり、しか
も脱窒菌量の制御と有機炭素源の使用量削減を同
時にかつ合理的に達成することができ簡便な運転
管理で従来の余剰脱窒菌の処理・処分に付随する
幾多の問題点を解消し、大幅に改良された脱窒処
理を遂行することができる。[Table] As described above, according to the present invention, denitrifying bacteria grown on a medium through a denitrification reaction using an organic carbon source (exo-breathing denitrification reaction) can be grown without the addition of an organic carbon source, that is, by using the constituent components of the denitrifying bacteria itself. After reducing excess denitrifying bacteria that have grown on the medium through a denitrification reaction using carbon as a reducing agent (endo-respiration type denitrification reaction), the denitrifying bacteria are grown again through a denitrification reaction using an organic carbon source. By using multiple denitrification processes to maintain the amount of denitrifying bacteria in the entire process at an appropriate predetermined amount, the amount of denitrifying bacteria in the entire wastewater treatment process can be easily and economically maintained at an appropriate predetermined amount. As a result, there is no need to discharge excess denitrifying bacteria outside the wastewater treatment process.
It eliminates the need for processing equipment and processing costs such as separation of denitrifying bacteria from the medium, dehydration and drying of denitrifying bacteria after separation, and makes it easy and economical to dispose of surplus denitrifying bacteria. Since the endorespiratory denitrification reaction is used as a means to maintain the amount of denitrifying bacteria at an appropriate predetermined amount, an amount of organic carbon source corresponding to the amount of denitrifying bacteria required for the reaction can be saved. Extremely economical wastewater treatment is possible, and it is possible to control the amount of denitrifying bacteria and reduce the amount of organic carbon source used at the same time and rationally.With simple operation management, it is possible to treat and dispose of excess denitrifying bacteria as before. Many of the accompanying problems can be eliminated and a significantly improved denitrification process can be achieved.
図面は本発明の実施態様を示す系統説明図であ
る。
１……NH3含有廃水、１′……NH3を含有しな
い廃水、２……硝化工程、３……硝化水、４……
上澄水、５……有機炭素源、６……媒体返送ライ
ン、７……媒体移送ライン、８……処理水、Ａ…
…脱窒工程、Ｂ……脱窒工程。
The drawings are system explanatory diagrams showing embodiments of the present invention. 1...Wastewater containing NH3 , 1'...Wastewater not containing NH3 , 2...Nitrification process, 3...Nitrified water, 4...
Supernatant water, 5... Organic carbon source, 6... Medium return line, 7... Medium transfer line, 8... Treated water, A...
...Denitrification process, B...Denitrification process.
Claims (1)
（NOx―Ｎ）を除去するに際し、脱窒工程を(A)，
(B)の２工程に分離し、硝化水を脱窒工程(A)に流入
せしめて該脱窒工程(A)で有機炭素源注入量を零乃
至脱窒菌が減少する量にして硝化水中のNOx―Ｎ
の一部を除去し、次いで残留NOx―Ｎを脱窒工程
(B)において有機炭素源を注入して脱窒処理する方
法において、前記脱窒工程(B)の余剰脱窒菌を媒体
とともに前記脱窒工程(A)へ移送し、脱窒工程(A)に
おいて内呼吸型脱窒反応によつて脱窒菌が減少し
たのち媒体を脱窒工程(B)へ返送することを特徴と
する廃水の生物学的脱窒法。 ２ 前記脱窒工程(A)，(B)のうちの少なくとも一つ
の工程が、複数の槽又は塔を用いて処理されるも
のである特許請求の範囲第１項記載の廃水の生物
学的脱窒法。 ３ 前記脱窒工程(A)，(B)が、有機炭素源としてメ
タノールを使用して処理されるものである特許請
求の範囲第１項，又は第２項記載の廃水の生物学
的脱窒法。 ４ 前記脱窒工程(A)，(B)のそれぞれが、粒状又は
フレーク状の形状で配管を通しての輸送が容易な
寸法及び強度の媒体を使用して処理されるもので
ある特許請求の範囲第１項，第２項又は第３項記
載の廃水の生物学的脱窒法。 ５ 前記脱窒工程(A)から脱窒工程(B)への媒体の返
送が、脱窒工程(A)からの上澄水を同伴しない状態
で行なわれるものである特許請求の範囲第１項，
第２項，第３項又は第４項記載の廃水の生物学的
脱窒法。 ６ 前記脱窒工程(A)から脱窒工程(B)への媒体の返
送が、脱窒工程(A)からの上澄水を同伴した状態で
行なわれるものである特許請求の範囲第１項，第
２項，第３項又は第４項記載の廃水の生物学的脱
窒法。 ７ 前記脱窒工程(A)から脱窒工程(B)への媒体の返
送が、脱窒工程(A)からの上澄水中に媒体が同伴さ
れ始めた時点で開始されるものである特許請求の
範囲第１項，第２項，第３項，第４項又は第６項
記載の廃水の生物学的脱窒法。 ８ 前記脱窒工程(A)から脱窒工程(B)への媒体の返
送及び脱窒工程(B)から脱窒工程(A)への媒体の移送
が、媒体の層高を検知して行なわれるものである
特許請求の範囲第１項，第２項，第３項，第４
項，第５項又は第６項記載の廃水の生物学的脱窒
法。 ９ 前記脱窒工程(A)から脱窒工程(B)への媒体の返
送及び脱窒工程(B)から脱窒工程(A)への媒体の移送
が、間歇的に一定時間行なわれるようにタイマに
よつて設定されるものである特許請求の範囲第１
項，第２項，第３項，第４項，第５項又は第６項
記載の廃水の生物学的脱窒法。 １０ 前記脱窒工程(A)，(B)のそれぞれが、媒体と
して砂を使用して処理されるものである特許請求
の範囲第１項、第２項、第３項、第４項、第５
項、第６項、第７項、第８項、又は第９項記載の
廃水の生物学的脱窒法。 １１ 前記脱窒工程(A)から脱窒工程(B)への媒体の
返送が、脱窒工程(A)における媒体の層高が所定の
高さまで低下した時点で開始されるものである特
許請求の範囲第１項、第２項、第３項、第４項、
第５項、第６項、第８項又は第１０項記載の廃水
の生物学的脱窒法。 １２ 前記脱窒工程(B)から脱窒工程(A)への媒体の
移送が、脱窒工程(B)における媒体の層高が所定の
高さまで増大した時点で開始されるものである特
許請求の範囲第１項、第２項、第３項、第４項、
第５項、第６項、第８項、第１０項又は第１１項
記載の廃水の生物学的脱窒法。[Claims] 1. When removing oxidized nitrogen (NO x -N) using denitrifying bacteria attached to a medium, the denitrifying process is performed by (A),
The nitrified water is separated into two steps (B), and the nitrified water is flowed into the denitrification step (A), and in the denitrification step (A), the amount of organic carbon source injected is reduced to zero or to an amount that reduces the number of denitrifying bacteria in the nitrified water. NO x -N
After that, the residual NO x -N is removed through a denitrification process.
In the method of denitrification treatment by injecting an organic carbon source in (B), surplus denitrifying bacteria from the denitrification step (B) are transferred together with a medium to the denitrification step (A), and in the denitrification step (A), A biological denitrification method for wastewater characterized by returning the medium to the denitrification process (B) after denitrifying bacteria are reduced by an endorespiratory denitrification reaction. 2. Biological denitrification of wastewater according to claim 1, wherein at least one of the denitrification steps (A) and (B) is performed using a plurality of tanks or towers. Nitrogen method. 3. The biological denitrification method for wastewater according to claim 1 or 2, wherein the denitrification steps (A) and (B) are performed using methanol as an organic carbon source. . 4. Each of the denitrification steps (A) and (B) is carried out using a medium in the form of granules or flakes whose size and strength make it easy to transport through piping. Biological denitrification method for wastewater according to paragraph 1, paragraph 2 or paragraph 3. 5. Claim 1, wherein the medium is returned from the denitrification step (A) to the denitrification step (B) without entraining the supernatant water from the denitrification step (A).
Biological denitrification method for wastewater according to paragraph 2, paragraph 3 or paragraph 4. 6. Claim 1, wherein the return of the medium from the denitrification step (A) to the denitrification step (B) is carried out with the supernatant water from the denitrification step (A). Biological denitrification method for wastewater according to paragraph 2, paragraph 3 or paragraph 4. 7 A patent claim in which the return of the medium from the denitrification process (A) to the denitrification process (B) starts at the time when the medium starts to be entrained in the supernatant water from the denitrification process (A). A biological denitrification method for wastewater according to item 1, 2, 3, 4 or 6. 8 The return of the medium from the denitrification process (A) to the denitrification process (B) and the transfer of the medium from the denitrification process (B) to the denitrification process (A) are performed by detecting the layer height of the medium. Claims 1, 2, 3, and 4 which are
Biological denitrification method for wastewater as described in paragraph 5 or paragraph 6. 9 Returning the medium from the denitrification process (A) to the denitrification process (B) and transferring the medium from the denitrification process (B) to the denitrification process (A) are performed intermittently for a certain period of time. Claim 1, which is set by a timer
Biological denitrification method for wastewater as described in paragraph 2, paragraph 3, paragraph 4, paragraph 5, or paragraph 6. 10 Each of the denitrification steps (A) and (B) is performed using sand as a medium. 5
The method for biological denitrification of wastewater according to paragraph 6, paragraph 7, paragraph 8, or paragraph 9. 11 A patent claim in which the return of the medium from the denitrification process (A) to the denitrification process (B) is started when the layer height of the medium in the denitrification process (A) has decreased to a predetermined height. Range 1st term, 2nd term, 3rd term, 4th term,
The method for biological denitrification of wastewater according to paragraph 5, paragraph 6, paragraph 8 or paragraph 10. 12 A patent claim in which the transfer of the medium from the denitrification step (B) to the denitrification step (A) is started when the layer height of the medium in the denitrification step (B) increases to a predetermined height. Range 1st term, 2nd term, 3rd term, 4th term,
The method for biological denitrification of wastewater according to paragraph 5, paragraph 6, paragraph 8, paragraph 10 or paragraph 11.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12099079A JPS5645797A (en) | 1979-09-20 | 1979-09-20 | Biological denitrification of waste water |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12099079A JPS5645797A (en) | 1979-09-20 | 1979-09-20 | Biological denitrification of waste water |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5645797A JPS5645797A (en) | 1981-04-25 |
| JPS6260157B2 true JPS6260157B2 (en) | 1987-12-15 |
Family
ID=14800046
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12099079A Granted JPS5645797A (en) | 1979-09-20 | 1979-09-20 | Biological denitrification of waste water |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5645797A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4617572B2 (en) * | 2000-12-26 | 2011-01-26 | 日新製鋼株式会社 | Nitrogen-containing wastewater treatment method |
| JP5149736B2 (en) * | 2008-08-13 | 2013-02-20 | オルガノ株式会社 | Denitrification treatment method and denitrification treatment apparatus |
-
1979
- 1979-09-20 JP JP12099079A patent/JPS5645797A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5645797A (en) | 1981-04-25 |
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