JPS6146198B2 - - Google Patents
Info
- Publication number
- JPS6146198B2 JPS6146198B2 JP53014158A JP1415878A JPS6146198B2 JP S6146198 B2 JPS6146198 B2 JP S6146198B2 JP 53014158 A JP53014158 A JP 53014158A JP 1415878 A JP1415878 A JP 1415878A JP S6146198 B2 JPS6146198 B2 JP S6146198B2
- Authority
- JP
- Japan
- Prior art keywords
- treated water
- sludge
- water
- tank
- activated sludge
- 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
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 50
- 239000010802 sludge Substances 0.000 claims description 47
- 238000005273 aeration Methods 0.000 claims description 27
- -1 nitrite ions Chemical class 0.000 claims description 24
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 19
- 239000010800 human waste Substances 0.000 claims description 18
- 230000014759 maintenance of location Effects 0.000 claims description 12
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 claims description 10
- 229940005654 nitrite ion Drugs 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 8
- 239000001301 oxygen Substances 0.000 claims description 8
- 229910052760 oxygen Inorganic materials 0.000 claims description 8
- 241000894006 Bacteria Species 0.000 claims description 5
- 239000007789 gas Substances 0.000 claims description 5
- 230000003647 oxidation Effects 0.000 claims description 3
- 238000007254 oxidation reaction Methods 0.000 claims description 3
- 238000003756 stirring Methods 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 2
- 239000000701 coagulant Substances 0.000 claims 1
- 238000004042 decolorization Methods 0.000 description 12
- 238000000746 purification Methods 0.000 description 8
- 230000007423 decrease Effects 0.000 description 6
- 230000000813 microbial effect Effects 0.000 description 6
- 238000005345 coagulation Methods 0.000 description 5
- 230000015271 coagulation Effects 0.000 description 5
- 238000004062 sedimentation Methods 0.000 description 5
- 229910002651 NO3 Inorganic materials 0.000 description 4
- 241000605159 Nitrobacter Species 0.000 description 4
- 241000605122 Nitrosomonas Species 0.000 description 4
- 229910021529 ammonia Inorganic materials 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 4
- 239000004033 plastic Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000002156 mixing Methods 0.000 description 3
- 239000006228 supernatant Substances 0.000 description 3
- 238000013019 agitation Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910017464 nitrogen compound Inorganic materials 0.000 description 2
- 150000002830 nitrogen compounds Chemical class 0.000 description 2
- 238000006385 ozonation reaction Methods 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 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
- 239000004698 Polyethylene Substances 0.000 description 1
- 241000700605 Viruses Species 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 244000052616 bacterial pathogen Species 0.000 description 1
- 210000000941 bile Anatomy 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000029087 digestion Effects 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000005188 flotation Methods 0.000 description 1
- 238000013467 fragmentation Methods 0.000 description 1
- 238000006062 fragmentation reaction Methods 0.000 description 1
- 239000010842 industrial wastewater Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000009916 joint effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007269 microbial metabolism Effects 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 210000002700 urine Anatomy 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 239000002349 well water Substances 0.000 description 1
- 235000020681 well water Nutrition 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
- Treatment Of Water By Oxidation Or Reduction (AREA)
- Activated Sludge Processes (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Description
本発明はし尿の微生物処理から得られた処理水
をオゾン酸化で脱色浄化する方法の改良に関す
る。
従来、し尿は消化と呼ばれる嫌気性微生物処理
と活性汚泥法なる好気性微生物処理との組み合わ
せ、あるいは直接活性汚泥法で処理し沈殿上澄液
として放流されていた。この生成処理のみでは、
BOD、CODは除去されてもし尿特有の着色物質
である胆汁酸化物、茶褐色のフミン系化合物は除
去できず着色されたまま河川や海などへ放出され
ていたが、環境保全および水の再利用の観点から
近年この処理放流水を更に高度に浄化するため微
生物処理の後段に凝集処理オゾン処理などが追加
されている。
オゾンは強力な酸化力を持つ気体で、空気を原
料として電力のみで連続的に発生させることがで
き、排水の脱色、脱臭、汚染物質の酸化だけでな
く、病原菌の殺菌、ビールス不活性化も行なうこ
とができる。また塩素のように高圧容器に入れ取
り扱い保存することもなく、必要量だけオゾン発
生器の放電電圧あるいは放電周波数の変化によつ
て容易に発生させることができるため、し尿処理
設備として欠くことのできない装置となつてい
る。一般にはし尿の微生物処理水に凝集剤を添加
し、加圧浮上もしくは凝集沈殿により懸濁物を除
去し、その処理水をオゾン化ガスと接触させ、脱
色、脱臭、更にはCOD、BODの低減も行ない無
色の処理水として放出している。
人間の排泄物であるし尿は、比較的一定した化
学的性状を示し、活性汚泥処理を行なうにしても
工場排水などの毒物混入のある都市下水より安定
した運転管理が可能である。しかし、し尿は人為
的に汲取り処理されるため、週末、月末、年末な
どに多く、活性汚泥法に対する処理量負荷が大き
く変動してしまう。逆にこれ以外の期間では処理
量が少なくなり、活性汚泥のBOD負荷が低いま
ま曝気する結果過曝気状態となり、亜硝酸イオン
濃度が異常に増加する。この亜硝酸イオンの増加
は、次の凝集処理では問題ないが、オゾン脱色浄
化を行なう際亜硝酸イオンがオゾンと優先的に反
応するため、脱色の速度は著しく低下し完全な脱
色は亜硝酸イオンがなくなつてから行なわれる。
このためし尿処理量の少ない過曝気時において
は、通常必要とされたオゾン注入量ではほとんど
脱色できないという状態が起る。
つまり微生物を利用する活性汚泥処理におい
て、COD、BOD成分が微生物代謝を受け減少す
るに従い水中のアンモニアイオンを亜硝酸イオン
に酸化するニトロソモナス菌、亜硝酸イオンを硝
酸イオンに酸化するニトロバクタ菌の増殖が起
り、水中有機物の浄化だけでなく無機性のアンモ
ニアイオンの酸化が活発に行なわれる。このよう
に水中窒素化合物は、好気性状態でアンモニアイ
オン、亜硝酸イオン、硝酸イオンを経て最後に嫌
気性状態の脱窒素菌作用を受け、窒素ガスとして
大気中に放出される。
活性汚泥処理のかなり進行した状態において、
ニトロソモナス菌、ニトロバクタ菌の共同作用で
順次アンモニアイオンから硝酸イオンまで酸化さ
れてしまうのならば問題は起らない。しかしニト
ロソモナス菌、ニトロバクタ菌は弱アルカリ性の
方が最適活性を示し、また増殖速度はニトロソモ
ナス菌の方がニトロバクタ菌より大きいため、酸
性になりやすいし尿の活性汚泥処理水では水中窒
素化合物は亜硝酸イオンとして蓄積されてしま
う。このためし尿処理量の少ない期間、オゾン脱
色されにくい過曝気状態のし尿処理水が得られる
ことになる。
本発明は、過曝気状態の処理水を活性汚泥と分
離することなく、滞留槽に導き汚泥が沈降しない
程度に緩速撹拌を行ない、後段のオゾン酸化で障
害となる亜硝酸イオンを生物的に減少させる方法
である。嫌気性脱窒による気泡の発生がある場合
は、短時間の再曝気を行なつてから汚泥を分離
し、後段の凝集処理、オゾン処理もしくは直接オ
ゾン処理に送り脱色浄化された放流水を得る。更
にこの嫌気性による亜硝酸イオン濃度の減少速度
を曝気槽汚泥濃度3000〜4000で亜硝酸性窒素NO2
−N15ppm（亜硝酸イオン49.5ppm）以下におい
て調べたところ、約2.5〜5.0ppm NO2−Ｎ／hr
（亜硝酸イオン8.3〜16.3ppm）であり、初期の亜
硝酸イオン濃度に関係なく、生物反応特有の零次
反応で減少することが確められた。このことは亜
硝酸イオン濃度の高い処理水でも滞留時間に比例
して減少させることができることを示している。
しかし活性汚泥のBOD除去菌は数10時間嫌気的
に放置すると死滅、腐敗し再曝気を行なつても復
元しにくくなる。このため滞留時間は再曝気によ
るBOD除去菌の復元性によつて決まり、おのず
と処理可能な最大亜硝酸イオン濃度は決まつてし
まう。これらのことから前段の活性汚泥曝気槽の
溶存酸素を検出して曝気量を調節し、COD、
BOD除去を目的とした活性汚泥処理能力を低下
させることなく滞留槽で除去可能な亜硝酸イオン
濃度以下に保てば、後段のオゾン脱色浄化が安定
に行なえることになる。
次に本発明の一実施例を詳しく説明する。
実施例 １
し尿処理場の一段活性汚泥処理水を沈殿槽入口
で１ポリビンに採取し、汚泥が沈降分離しない
ようにまた水温の低下が起らないよう曝気槽にポ
リビンを吊るし、30分、60分、90分放置した後
PAC250ppm添加し、上澄液をNo5a紙で過
し、その水質変化を調べた。なお曝気槽水温は22
℃であり、Ａ、B2回の水質分析結果は第１表の
通りである。この場合、曝気槽内に吊されたポリ
ビンは曝気流によつて動き、５〜６秒は左右に移
動し、曝気槽壁に当つてはねかえつており、緩速
撹拌動作を受けている。このポリビンを引上げた
時、ポリビン下部に汚泥の沈降は認められなかつ
た。
The present invention relates to an improvement in a method for decolorizing and purifying treated water obtained from microbial treatment of human waste by ozone oxidation. Conventionally, human waste has been treated with a combination of anaerobic microbial treatment called digestion and aerobic microbial treatment called activated sludge, or directly treated with activated sludge, and then discharged as a precipitated supernatant. With this generation process alone,
Although BOD and COD have been removed, bile oxides and brown humic compounds, which are coloring substances unique to human urine, cannot be removed and are released into rivers and the sea as colored substances. From this point of view, in recent years, coagulation treatment, ozone treatment, etc. have been added after microbial treatment to further purify the treated effluent. Ozone is a gas with strong oxidizing power, and can be continuously generated using electricity alone using air as a raw material. It not only decolorizes and deodorizes wastewater and oxidizes pollutants, but also sterilizes pathogenic bacteria and inactivates viruses. can be done. In addition, unlike chlorine, there is no need to handle and store it in a high-pressure container, and the required amount can be easily generated by changing the discharge voltage or frequency of an ozone generator, making it an indispensable part of human waste treatment equipment. It has become a device. Generally, a flocculant is added to microbial-treated human waste water, suspended matter is removed by pressure flotation or coagulation sedimentation, and the treated water is brought into contact with ozonized gas to decolorize, deodorize, and further reduce COD and BOD. The water is also discharged as colorless treated water. Human excrement, human waste, exhibits relatively constant chemical properties, and even with activated sludge treatment, it is possible to operate more stably than urban sewage, which is contaminated with toxic substances such as industrial wastewater. However, since human waste is manually collected and treated, it is often collected on weekends, at the end of the month, and at the end of the year, and the processing load for the activated sludge method fluctuates greatly. On the other hand, in periods other than this, the amount of treatment decreases, and as a result of aeration while the BOD load of activated sludge is low, an overaeration state occurs, and the nitrite ion concentration increases abnormally. This increase in nitrite ions will not be a problem in the next coagulation process, but during ozone decolorization purification, nitrite ions react preferentially with ozone, so the speed of decolorization decreases significantly, and complete decolorization cannot be achieved with nitrite ions. It is carried out after the
Therefore, during overaeration when the amount of human waste to be processed is small, a situation occurs in which almost no decolorization is possible with the normally required amount of ozone injection. In other words, in activated sludge treatment using microorganisms, as COD and BOD components undergo microbial metabolism and decrease, Nitrosomonas bacteria, which oxidizes ammonia ions in water to nitrite ions, and Nitrobacter bacteria, which oxidize nitrite ions to nitrate ions, proliferate. occurs, and not only is the organic matter in the water purified, but also the oxidation of inorganic ammonia ions is actively carried out. In this way, nitrogen compounds in water pass through ammonia ions, nitrite ions, and nitrate ions in an aerobic state, and finally undergo the action of denitrifying bacteria in an anaerobic state, and are released into the atmosphere as nitrogen gas. When activated sludge treatment has progressed considerably,
No problem will occur if the ammonia ions are sequentially oxidized to nitrate ions through the joint action of Nitrosomonas bacteria and Nitrobacter bacteria. However, Nitrosomonas and Nitrobacter exhibit optimal activity in weak alkaline conditions, and the growth rate of Nitrosomonas is greater than that of Nitrobacter, so in activated sludge treated water of human waste, which tends to become acidic, nitrogen compounds in the water are It accumulates as nitrate ions. As a result, during a period when the amount of human waste to be processed is small, treated human waste water in an over-aerated state that is difficult to be decolorized by ozone is obtained. The present invention introduces over-aerated treated water into a retention tank without separating it from activated sludge, and performs slow agitation to prevent the sludge from settling. This is a method of reducing If bubbles are generated due to anaerobic denitrification, the sludge is separated after a short period of re-aeration and sent to subsequent coagulation treatment, ozonation treatment, or direct ozonation treatment to obtain decolorized and purified effluent water. Furthermore, the rate of decrease in nitrite ion concentration due to this anaerobic effect was determined by nitrite nitrogen NO 2 at an aeration tank sludge concentration of 3000 to 4000.
When investigated at -N15ppm (nitrite ion 49.5ppm) or less, approximately 2.5 to 5.0ppm NO 2 -N/hr
(8.3 to 16.3 ppm of nitrite ions), and it was confirmed that the concentration of nitrite ions decreases due to the zero-order reaction characteristic of biological reactions, regardless of the initial nitrite ion concentration. This shows that even treated water with a high nitrite ion concentration can be reduced in proportion to the residence time.
However, the BOD removal bacteria in activated sludge die and decompose if left anaerobically for several tens of hours, making it difficult to restore even if reaeration is performed. Therefore, the residence time is determined by the recovery ability of the BOD removal bacteria by re-aeration, and the maximum nitrite ion concentration that can be treated is naturally determined. Based on these facts, dissolved oxygen in the activated sludge aeration tank in the previous stage is detected and the aeration amount is adjusted to reduce COD,
If the nitrite ion concentration is kept below the level that can be removed in the retention tank without reducing the activated sludge treatment capacity for BOD removal, the subsequent ozone decolorization and purification can be performed stably. Next, one embodiment of the present invention will be described in detail. Example 1 First-stage activated sludge treated water from a human waste treatment plant was collected in a plastic bottle at the entrance of a settling tank, and the plastic bottle was hung in an aeration tank to prevent the sludge from settling and separating and to prevent a drop in water temperature. minutes, after leaving for 90 minutes
250 ppm of PAC was added and the supernatant liquid was filtered through No5a paper to examine changes in water quality. The aeration tank water temperature is 22
℃, and the results of the two water quality analyzes A and B are shown in Table 1. In this case, the polyethylene bottle suspended in the aeration tank is moved by the aeration flow, moves from side to side for 5 to 6 seconds, bounces against the wall of the aeration tank, and is subjected to a slow stirring action. When this plastic bottle was pulled up, no sludge sedimentation was observed at the bottom of the plastic bottle.
【表】
この結果よりオゾン脱色浄化で脱色速度を遅ら
せ、1ppmあたり3.43ppmのオゾンを無駄にする
NO2−Ｎ（亜硝酸イオンとして3.3ppm）を単に
汚泥と混合状態に保つことで簡単に減少させるこ
とのできることがわかる。
実施例 ２
実施例１と同様に60分放置し、次に15分再曝気
を行なつた場合の水質変化と30分放置による汚泥
体積SV30を測定した。４回の測定結果は第２表
の通りである。
ただしＡは原水、Ｂは60分放置、Ｃはさらに15
分再曝気した試料を示し、60分放置後の試料Ｂの
SV30には汚泥の一部浮上があつたので、沈殿部
＋浮上部の両者を表示した。[Table] From this result, ozone decolorization purification slows down the decolorization speed and wastes 3.43ppm of ozone per 1ppm.
It can be seen that NO 2 -N (3.3 ppm as nitrite ions) can be easily reduced by simply keeping it mixed with the sludge. Example 2 As in Example 1, the water quality was left to stand for 60 minutes and then re-aerated for 15 minutes. Changes in water quality and sludge volume SV30 after 30 minutes were measured. The results of the four measurements are shown in Table 2. However, A is raw water, B is left for 60 minutes, and C is an additional 15 minutes.
The sample B after being left for 60 minutes is shown.
Since some of the sludge surfaced in SV30, both the settling part and the floating part were displayed.
【表】
実施例１と同様に60分放置によりNO2−Ｎ、
NO3−Ｎは減少するが、再曝気によつて多少水質
の低下が認められた。
特にし尿の処理では懸濁物の少ない処理水と濃
度の高い返送汚泥を得るように微生物処理全体を
調節する必要がある。上記結果からNO2−Ｎが４
〜5ppm（亜硝酸イオンとして13.2〜16.5ppm）
以下ならば、60分放置、15分再曝気で汚泥沈降性
を復元することができる。しかしこれ以上の濃度
では沈降性の悪い処理水となつてしまう。
このため前段活性汚泥を調節して、NO2−Ｎ生
成を数ppm程度に保てば、滞留、再曝気による
水質低下、BOD除去菌の死滅や腐敗もなくオゾ
ン脱色浄化に適した処理水が得られ安定した処理
ができる。
本発明による活性汚泥曝気槽に滞留槽、再曝気
槽を加えた脱色浄化方法の具体的構成は図のよう
になる。
図において、し尿を嫌気性もしくは好気性処理
した脱離水１は、河川水、井水あるいは海水を利
用した希釈水２と共に混合槽３に送入され、また
後述する沈殿槽から返送される返送汚泥４と共に
混合され、曝気槽５に送られる。しかしてブロワ
６から散気管７を介して噴出される空気により曝
気され好気的にCOD、BODが除去される。一方
溶存酸素計８で曝気槽５の溶存酸素を検出し、一
定濃度以上になつたときもしくは一定濃度以下に
なつたとき、調節器９によつてブロワ６からの空
気量を調節し亜硝酸イオンを一定濃度以下に保
つ。曝気槽５からの処理水は、滞留槽１０に送ら
れ汚泥が沈降しないように緩速撹拌機１１により
ゆつくり撹拌し、処理水中の亜硝酸イオンを嫌気
的に除去する。ここで、上記緩速撹拌機１１によ
る撹拌は、処理水中で汚泥の沈降する力（ストー
クス則に近い値）以上の力で撹拌すればよく、し
尿処理場での現地テスト結果では、１m3タンクに
水中モータと設置し、表面の回転が８〜15回転／
分となる程度でゆつくり回転させた。この場合、
渦が生じ、その中心から空気が吸い込まれるよう
な速度で撹拌すると、嫌気性な条件には保てず、
また汚泥の細分化により全体の処理に悪影響を与
える。次に再曝気槽１２で短時間の曝気を行ない
沈殿槽１３に導き、上澄は混合槽１４で凝集剤１
５を添加し、凝集沈殿槽１６で汚泥１７を分離後
オゾン脱色浄化塔１８でオゾン発生機１９で生成
したオゾン化ガス２０と接触反応させ、無色の浄
化された放流水２１とする。一方沈殿槽１３で分
離された汚泥は、上記したように返送汚泥４とし
て混合槽３に送られ、増加した量だけ余剰汚泥２
２として処理される。なお同図中２３はブロワ、
２４は散気管を示す。
ここで、上述した曝気槽内処理水の溶存酸素と
滞留槽での滞留時間との関係を説明する。水温22
℃、汚泥濃度3000〜4000（mg/）の活性汚泥法
で処理した水を１時間滞留させることにより処理
水中の亜硝酸イオンを16.5ppm除去できる。ま
た、亜硝酸イオンが16.5ppm発生している条件
は、曝気槽分布を調べたところ、溶存酸素２〜
2.5ppmであつた。これらのことから、１時間の
滞留槽を用いた場合、曝気槽出口の溶存酸素測定
値が２〜2.5ppmであれば、曝気槽で生じた亜硝
酸イオンを滞留槽で除去でき、後述のオゾン脱色
に問題は生じない。
このように本発明は、既設処理設備の曝気槽と
沈殿槽の間に滞留槽、再曝気槽を設け、前段活性
汚泥処理の曝気量を溶存酸素濃度で調節すればよ
いから、し尿の３次処理としてのオゾン脱色浄化
を安定して行なうことができる。[Table] As in Example 1, by standing for 60 minutes, NO 2 -N,
Although NO 3 -N decreased, a slight decrease in water quality was observed due to reaeration. Particularly in the treatment of human waste, it is necessary to adjust the entire microbial treatment to obtain treated water with few suspended substances and return sludge with a high concentration. From the above results, NO 2 -N is 4
~5ppm (13.2-16.5ppm as nitrite ion)
If it is below, sludge settling property can be restored by leaving it for 60 minutes and re-aerating for 15 minutes. However, if the concentration is higher than this, the treated water will have poor sedimentation properties. Therefore, if the activated sludge in the first stage is adjusted to keep NO 2 -N generation at around several ppm, treated water suitable for ozone decolorization purification will be produced without deterioration of water quality due to stagnation and reaeration, and without killing or decomposition of BOD removal bacteria. and stable processing is possible. The specific configuration of the decolorization and purification method according to the present invention, which includes an activated sludge aeration tank, a retention tank, and a reaeration tank, is shown in the figure. In the figure, desorbed water 1 obtained by anaerobically or aerobically treating human waste is sent to a mixing tank 3 together with dilution water 2 using river water, well water, or seawater, and return sludge is returned from a settling tank described later. 4 and sent to the aeration tank 5. The air is then aerated with the air blown out from the blower 6 through the diffuser pipe 7, and COD and BOD are removed aerobically. On the other hand, the dissolved oxygen meter 8 detects the dissolved oxygen in the aeration tank 5, and when the concentration exceeds a certain level or falls below a certain level, the regulator 9 adjusts the amount of air from the blower 6 to ionize nitrite ions. Keep the concentration below a certain level. The treated water from the aeration tank 5 is sent to a retention tank 10, where it is slowly stirred by a slow stirrer 11 to prevent sludge from settling, and nitrite ions in the treated water are anaerobically removed. Here, the agitation by the slow agitator 11 may be performed with a force greater than or equal to the force that causes the sludge to settle in the treated water (a value close to Stokes' law), and according to field test results at human waste treatment plants, it is sufficient to agitate the sludge in a 1 m 3 tank. A submersible motor is installed on the surface, and the surface rotation is 8 to 15 rotations/
I rotated it slowly for about a minute. in this case,
If the mixture is stirred at such a speed that a vortex is created and air is sucked in from the center, anaerobic conditions cannot be maintained;
Furthermore, the fragmentation of sludge adversely affects the overall treatment. Next, aeration is carried out for a short time in the re-aeration tank 12, and the supernatant is transferred to the settling tank 13.
After separating the sludge 17 in the coagulation sedimentation tank 16, the sludge 17 is brought into contact with the ozonized gas 20 generated in the ozone generator 19 in the ozone decolorization purification tower 18, and is made into colorless purified effluent water 21. On the other hand, the sludge separated in the settling tank 13 is sent to the mixing tank 3 as the return sludge 4 as described above, and the excess sludge 2 is increased by the increased amount.
Processed as 2. In addition, 23 in the figure is a blower,
24 indicates a diffuser pipe. Here, the relationship between the above-mentioned dissolved oxygen in the treated water in the aeration tank and the residence time in the retention tank will be explained. water temperature 22
16.5 ppm of nitrite ions in the treated water can be removed by retaining water treated by the activated sludge method at a temperature of 3000 to 4000 (mg/) for 1 hour. In addition, when examining the aeration tank distribution, the conditions under which nitrite ions are generated at 16.5 ppm are found to be
It was 2.5ppm. Based on these facts, when using a retention tank for 1 hour, if the measured value of dissolved oxygen at the aeration tank outlet is 2 to 2.5 ppm, the nitrite ions generated in the aeration tank can be removed in the retention tank, and the ozone There are no problems with bleaching. In this way, the present invention provides a retention tank and a re-aeration tank between the aeration tank and the settling tank of the existing treatment equipment, and the amount of aeration in the first-stage activated sludge treatment can be adjusted by the dissolved oxygen concentration. Ozone decolorization and purification as a treatment can be performed stably.
図は本発明の一実施例を示す系統図である。
３，１４……混合槽、５……曝気槽、８……溶
存酸素計、１０……滞留槽、１３……沈殿槽、１
８……オゾン脱色浄化塔。
The figure is a system diagram showing one embodiment of the present invention. 3, 14... Mixing tank, 5... Aeration tank, 8... Dissolved oxygen meter, 10... Retention tank, 13... Sedimentation tank, 1
8...Ozone decolorization purification tower.
Claims (1)
を添加し懸濁物を除いた処理水をオゾン化ガスで
脱色浄化するものにおいて、活性汚泥処理後の処
理水を滞留槽にて、空気を吸い込むような渦が生
じず、かつ処理水中で汚泥が沈降する力以上の力
で撹拌する緩速撹拌を行い、亜硝酸イオン濃度を
嫌気的に減少させた後、さらに沈殿槽で汚泥を分
離し、オゾン酸化することを特徴とするし尿の脱
色浄化方法。 ２ し尿の活性汚泥処理水もしくはこれに凝集剤
を添加し懸濁物を除いた処理水をオゾン化ガスで
脱色浄化するものにおいて、活性汚泥処理後の処
理水を滞留槽にて、空気を吸い込むような渦が生
じず、かつ処理水中で汚泥が沈降する力以上の力
で撹拌する緩速撹拌を行い、亜硝酸イオン濃度を
嫌気的に減少させた後、さらに沈殿槽で汚泥を分
離し、オゾン酸化するに当り、前記活性汚泥処理
用の曝気槽内処理水の溶存酸素を検出し、この処
理水中の亜硝酸イオン濃度が、後続する滞留槽で
の嫌気的処理にて前記処理水中のBOD除去菌を
死滅させない程度の滞留時間内で除去可能な濃度
以下となるように曝気量を制御することを特徴と
するし尿の脱色浄化方法。[Scope of Claims] 1. In a system that decolorizes and purifies activated sludge-treated human waste water or treated water obtained by adding a flocculant and removing suspended matter using ozonated gas, the treated water after activated sludge treatment is transferred to a retention tank. After anaerobically reducing the nitrite ion concentration by performing slow stirring that does not create a vortex that sucks air and with a force greater than the force that causes the sludge to settle in the treated water, the sludge is further stirred in the settling tank. A method for decolorizing and purifying human waste, which is characterized by separating sludge with water and oxidizing it with ozone. 2 In a system that decolorizes and purifies activated sludge-treated human waste water or treated water after adding a coagulant and removing suspended matter using ozonated gas, air is sucked into the treated water after activated sludge treatment in a retention tank. After reducing the nitrite ion concentration anaerobically by performing slow stirring without creating a vortex and with a force greater than the force that causes the sludge to settle in the treated water, the sludge is further separated in a settling tank. During ozone oxidation, dissolved oxygen in the treated water in the aeration tank for activated sludge treatment is detected, and the concentration of nitrite ions in the treated water is determined by the BOD in the treated water in the subsequent anaerobic treatment in the retention tank. A method for decolorizing and purifying human waste, characterized by controlling the amount of aeration so that the concentration is below that which can be removed within a residence time that does not kill the removed bacteria.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1415878A JPS54108458A (en) | 1978-02-13 | 1978-02-13 | Method of decoloring and purifying night-soil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1415878A JPS54108458A (en) | 1978-02-13 | 1978-02-13 | Method of decoloring and purifying night-soil |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS54108458A JPS54108458A (en) | 1979-08-25 |
| JPS6146198B2 true JPS6146198B2 (en) | 1986-10-13 |
Family
ID=11853334
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1415878A Granted JPS54108458A (en) | 1978-02-13 | 1978-02-13 | Method of decoloring and purifying night-soil |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS54108458A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04128197U (en) * | 1991-05-17 | 1992-11-24 | 株式会社ハーミス | Molded product removal device |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2539572B2 (en) * | 1992-08-28 | 1996-10-02 | 日本碍子株式会社 | Sewage treatment device using packed bed |
| JP2529804B2 (en) * | 1992-08-28 | 1996-09-04 | 日本碍子株式会社 | Sewage treatment device using packed bed |
| US6872313B1 (en) * | 2002-09-23 | 2005-03-29 | Agrimond Usa Corporation | Domestic wastewater treatment system |
-
1978
- 1978-02-13 JP JP1415878A patent/JPS54108458A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04128197U (en) * | 1991-05-17 | 1992-11-24 | 株式会社ハーミス | Molded product removal device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54108458A (en) | 1979-08-25 |
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