JPH06315695A - Pretreatment of activated sludge - Google Patents
Pretreatment of activated sludgeInfo
- Publication number
- JPH06315695A JPH06315695A JP24660691A JP24660691A JPH06315695A JP H06315695 A JPH06315695 A JP H06315695A JP 24660691 A JP24660691 A JP 24660691A JP 24660691 A JP24660691 A JP 24660691A JP H06315695 A JPH06315695 A JP H06315695A
- Authority
- JP
- Japan
- Prior art keywords
- sludge
- raw water
- activated sludge
- reaction
- activated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/20—Sludge processing
Landscapes
- Physical Water Treatments (AREA)
- Treatment Of Sludge (AREA)
- Activated Sludge Processes (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は都市下水・団地下水・小
規模農村集落廃水や食品・染色・皮革・化学・電気産業
等で微生物分解できる有機性廃水を活性汚泥を用いて処
理する方法に係り、活性汚泥処理するに当たりそれぞれ
特徴のある原排水が流れてきても、あらかじめ前処理を
することにより汎用的な設備でバルキングが発生しにく
く、無人自動運転が容易に達成出来るようにし、あわせ
て廃水処理設備設置面積を少なくし、かつ余剰汚泥の発
生が少なくなるばかりでなく余剰汚泥を有効資源として
活用するのに適した活性汚泥処理方法を提供することに
関する。[Industrial field of application] The present invention relates to a method for treating activated wastewater, which is capable of biodegrading microbial wastewater such as urban sewage, group groundwater, small-scale rural settlement wastewater and food, dyeing, leather, chemical and electrical industries. Therefore, even if the characteristic wastewater flows from each of the activated sludge treatments, it is possible to prevent bulking from occurring in a general-purpose facility by pre-treating it in advance so that unattended automatic operation can be easily achieved. The present invention relates to providing an activated sludge treatment method that not only reduces the installation area of wastewater treatment equipment and reduces the generation of excess sludge, but is also suitable for utilizing excess sludge as an effective resource.
【0002】[0002]
【従来の技術】活性汚泥処理方法は極めて優れた排水処
理方法であるため、広く排水処理に用いられ、原水の種
類に応じていろいろな処理方式が提案されている。2. Description of the Related Art Since activated sludge treatment method is an extremely excellent wastewater treatment method, it is widely used for wastewater treatment, and various treatment methods have been proposed according to the type of raw water.
【0003】従来の活性汚泥処理法は食物連鎖を利用し
て土壌細菌から大型の原生動物に至るまで種々の微生物
が利用されている。Conventional activated sludge treatment methods utilize various microorganisms ranging from soil bacteria to large protozoa utilizing the food chain.
【0004】活性汚泥法は前処理としてスクリーンや加
圧浮上や凝集沈降処理で荒いものから微細なものまで原
水中に分散していたものを除去して、微生物処理に適し
た可溶性有機分を活性汚泥で曝気処理したのち、処理水
を活性汚泥から分離して放流し、濃縮分離した活性汚泥
は返送汚泥として再循環使用される。そして余剰汚泥は
この返送汚泥の一部を抜き出して処分する。系外に排出
される汚泥はこれと前処理して除去された汚泥を混合し
てそのまま脱水したり、消化槽で消化させてから脱水し
た脱水ケーキを埋め立てや菌体肥料や焼却処分してい
る。In the activated sludge method, as a pretreatment, screens, pressure flotation, and coagulation sedimentation treatment are performed to remove those dispersed in raw water from rough to fine ones, and activate soluble organic components suitable for microbial treatment. After aeration treatment with sludge, the treated water is separated from the activated sludge and discharged, and the concentrated and separated activated sludge is recycled and used as return sludge. Then, excess sludge is extracted by discarding a part of the returned sludge. The sludge discharged to the outside of the system is mixed with the sludge removed by pretreatment and dehydrated as it is, or the dehydrated cake that has been digested in the digestion tank and then dehydrated is landfilled, microbial fertilizer, or incinerated. .
【0005】[0005]
【発明が解決しようとする課題】このように従来の活性
汚泥処理法は極めて完成度の高い方法であるが、なお解
決しなければならない問題があった。以下それらを述べ
る。As described above, the conventional activated sludge treatment method has a very high degree of perfection, but it still has a problem to be solved. These are described below.
【0006】(1)流入原水中に微生物が分解しにくい
難分解性物質(蛋白質・変成蛋白質やセルロース・澱粉
や油脂分)が多い場合は、活性汚泥がこれらを吸着した
状態でなかなか分解できないために、糸状細菌の発生等
により糸状性バルキングや放線菌等による発泡スカムの
発生等の処理異状現象を引き起こし、活性汚泥処理能力
を著しく損なう問題がある。このため、加圧浮上設備を
導入してこれらの難分解性物質を除去すると原水中の有
機分濃度が極端に低下し活性汚泥で処理する部分が減少
する反面、除去した産業廃棄物の発生量が多くなり、そ
の処分が問題となる。また浮上汚泥を脱水するにあた
り、一般的には凝集性が不安定であり凝集脱水しにくく
含水率も低くなりにくいのみならず、汚泥は腐敗しやす
く悪臭を発生し作業環境問題をおこしたりしやすい。し
たがって、総合的には浮上分離した汚泥の処理に多くの
問題点が集中し排水処理コストの上昇を引き起こし、活
性汚泥処理方法の長所を著しく損なうので、あまり普及
していない。それらの問題を避けるため前処理で除去し
ないで、曝気槽を大きくして長時間曝気して消化させる
方法が普及したが(ラグーン方式)、これは排水量が多
く成ったり負荷が大きい場合は膨大な曝気槽が必要にな
るため、敷地が無かったり建設費が膨大になるなどの問
題がある。(1) When the inflowing raw water contains a large amount of hardly-decomposable substances (proteins, denatured proteins, cellulose, starch, fats and oils) that are difficult for microorganisms to decompose, activated sludge cannot readily decompose these adsorbed substances. In addition, there is a problem that the filamentous bulking and the occurrence of foaming scum due to actinomycetes and the like cause abnormalities in the treatment due to the generation of filamentous bacteria, which significantly impairs the activated sludge treatment capacity. For this reason, if pressure resistant flotation equipment is installed and these persistent substances are removed, the concentration of organic components in the raw water will drop significantly and the amount of activated sludge to be treated will decrease, while the amount of industrial waste removed will be reduced. And the disposal becomes a problem. In addition, when dewatering floating sludge, in general, cohesiveness is unstable and it is difficult for coagulation and dewatering to reduce the water content, and sludge is prone to spoilage and odors, which may cause work environment problems. . Therefore, as a whole, many problems are concentrated in the treatment of the sludge that has been floated and separated, which causes an increase in wastewater treatment cost and remarkably impairs the advantages of the activated sludge treatment method. In order to avoid these problems, the method of enlarging the aeration tank and aerating for a long time without digesting it has become popular (lagoon method), but this is enormous when the amount of drainage is large or the load is large. Since an aeration tank is required, there are problems such as no site and huge construction costs.
【0007】(2)微生物処理を行うに当たり、流入原
水中のpHが中性から大きくずれている場合は中性付近
を維持するために酸やアルカリを添加して中和してい
る。しかし、薬品添加量が多くなり処理水中の塩濃度が
上がり、3次処理して再循環する場合に問題が発生する
のみならず、処理水のpHが異常値を示したり、設備の
腐食を促進したりする問題を引き起こす。例えば、原水
のpHが低い場合に苛性ソーダで中和するが、原水中の
脂肪酸が活性汚泥の曝気を十分行うと飼化されて、アル
カリ性に成り活性汚泥が損傷を受けたり、逆に原水がア
ルカリ性の場合は硫酸で中和するのが一般的であるが、
硫酸還元菌の増殖を促進して硫化水素による腐食の問題
が発生したり、活性汚泥が損傷を受け糸状性バルキング
を引き起こしたりする。したがってこれらの薬品を添加
すると薬品代がかかるのみならず弊害もあるので、原水
のpH調整方法に問題である。(2) In carrying out microbial treatment, when the pH of the influent raw water is largely deviated from neutral, an acid or alkali is added to neutralize it in order to maintain the neutral pH. However, the amount of chemicals added increases, the salt concentration in the treated water rises, and problems not only occur when recirculating after the third treatment, but the pH of the treated water shows an abnormal value and promotes corrosion of equipment. Or cause problems. For example, when the pH of the raw water is low, it is neutralized with caustic soda, but if the fatty acids in the raw water are aerated sufficiently to aerate the activated sludge, it becomes alkaline and the activated sludge is damaged, or conversely, the raw water becomes alkaline. In the case of, it is common to neutralize with sulfuric acid,
It promotes the growth of sulfate-reducing bacteria and causes the problem of corrosion due to hydrogen sulfide, and the activated sludge is damaged to cause filamentous bulking. Therefore, the addition of these chemicals not only costs the chemicals but also has an adverse effect, which is a problem in the pH adjusting method of the raw water.
【0008】(3)活性汚泥法は活性汚泥を殺菌するよ
うな物質が流入すると、活性汚泥が損傷を受け、原水の
浄化機能を失ったり糸状細菌性バルキングを引き起こし
たりしやすい。しかし、少量の殺菌剤や活性汚泥に悪影
響を与える物質を全く排水に流さないわけにはいかない
ので、これらの除去が問題である。(3) In the activated sludge method, when a substance that sterilizes the activated sludge flows in, the activated sludge is damaged, and it is easy to lose the purification function of raw water or to cause filamentous bacterial bulking. However, it is inevitable to remove a small amount of a sterilizing agent or a substance that has an adverse effect on the activated sludge into the wastewater, so that the removal of these substances is a problem.
【0009】[0009]
【課題を解決するための手段】本発明は以上述べた問題
点のすべてを合理的に解決するためには活性汚泥処理の
前処理方法に手段を求め解決した。In order to rationally solve all of the problems mentioned above, the present invention seeks means for a pretreatment method for activated sludge treatment and solves the problems.
【0010】まず、流入原水中の大きな固形分はスクリ
ーン等で除去し、その原水体積100部に対して反応汚
泥(返送汚泥)体積1部から30部、好ましくは3から
15部を原水調整槽があればそこに添加するか、原水汲
み上げ配管内か、あるいは原水反応槽を設けて、それぞ
れ原水と攪拌混合して、原水中の難分解性物質や活性汚
泥を破壊する物質を反応汚泥に接触吸着させた後、この
反応汚泥を加圧浮上濃縮分離して、0.5%以上好まし
くは1.5%以上の固形分を含む汚泥(吸着濃縮反応汚
泥)と加圧浮上処理水(処理原水)とを得る。原水と反
応汚泥との平均混合割合は、曝気槽で活性汚泥が増殖す
る量であり、返送汚泥濃度(余剰汚泥濃度)に依存す
る。反応汚泥の混合割合の下限値は原水中の悪影響物質
を除去する効果が現れる最少量であり、1部で効果が出
てくるが、好ましくは3部である。またその上限は流入
原水中の難分解性物質や殺菌剤等の活性汚泥に悪影響が
あると考えられる汚濁物質量に依存しているが、一時的
には特に上限は定められないが、1日以上の平均値では
曝気槽の汚泥濃度が水処理に悪影響が現れないところを
上限としなければならないので、自ずから制限が付けら
れる。それは、反応汚泥を加圧浮上処理したのちの処理
原水のBODやSSならびに返送汚泥濃度に依存してお
り、経験上30部を超えて反応汚泥を1日以上抜き出す
と曝気槽濃度が薄くなり処理に問題を起こすことがあ
り、安定的には3部から15部が好ましい。First, large solids in the inflowing raw water are removed by a screen or the like, and the reaction sludge (returning sludge) volume of 1 to 30 parts, preferably 3 to 15 parts, relative to the raw water volume of 100 parts, is adjusted to the raw water adjusting tank. If there is any, add it there, or in the raw water pumping pipe, or install a raw water reaction tank, stir and mix with the raw water, respectively, and contact the persistent sludge in the raw water or the substance that destroys the activated sludge with the reaction sludge. After being adsorbed, the reaction sludge is pressure-floated, concentrated and separated to obtain sludge containing 0.5% or more, preferably 1.5% or more of solid content (adsorption-concentrated reaction sludge) and pressure-floating treated water (treated raw water). ) And get. The average mixing ratio of the raw water and the reaction sludge is the amount of activated sludge that grows in the aeration tank, and depends on the returned sludge concentration (excess sludge concentration). The lower limit of the mixing ratio of the reaction sludge is the minimum amount at which the effect of removing harmful substances in the raw water is exhibited, and the effect comes out at 1 part, but is preferably 3 parts. The upper limit depends on the amount of pollutants that are considered to have an adverse effect on activated sludge, such as persistent substances and bactericides, in the raw water inflow. With the above average values, the upper limit must be set so that the sludge concentration in the aeration tank does not adversely affect the water treatment, so the limit is naturally imposed. It depends on the BOD and SS of the treated raw water after returning the sludge under pressure to the treated sludge, and the concentration of the returned sludge. From experience, if the reaction sludge is extracted for more than 1 day for more than 1 day, the concentration of the aeration tank will decrease. May occur, and 3 to 15 parts is preferable for stability.
【0011】これらの混合割合で反応汚泥を混合したの
ち加圧浮上設備でそれを除去された処理原水は、活性汚
泥曝気槽で返送汚泥といっしょに曝気処理後固液分離し
て、最終放流水と返送汚泥とを得る。返送汚泥の一部を
反応汚泥として原水反応槽に供給する。吸着濃縮反応汚
泥は、濃厚汚泥消化槽で嫌気・好気消化し、反応汚泥が
吸着した汚濁物質は微生物分解され、消化汚泥を得る。
そして、この消化汚泥を引き抜き除去する手段を用いる
ことを特徴とするものである。The treated raw water obtained by mixing the reaction sludge in these mixing ratios and then removing it in the pressure flotation equipment is subjected to aeration treatment with the returned sludge in the activated sludge aeration tank, solid-liquid separated, and finally discharged water. And get back the sludge. Part of the returned sludge is supplied to the raw water reaction tank as reaction sludge. The adsorption-concentrated reaction sludge is anaerobically and aerobically digested in a concentrated sludge digestion tank, and the pollutants adsorbed by the reaction sludge are microbially decomposed to obtain digested sludge.
And it is characterized by using means for extracting and removing this digested sludge.
【0012】[0012]
【作用】本発明の活性汚泥前処理方法は従来の活性汚泥
法では不用となり引き抜いて廃棄されている余剰汚泥
(返送汚泥)を反応汚泥として微生物吸着剤として用い
ることにより、流入原水中の難分解性物質をはじめ、活
性汚泥に吸着して活性汚泥を損傷させる殺菌剤等の物質
や強酸や強アルカリ等の微生物に悪影響を与える物質を
選択的に反応汚泥に吸着し、その汚泥を系外に除去する
ため、活性汚泥の損傷を防止し、活性汚泥の活性を高い
状態に保つので、活性汚泥の膨化や発泡スカムによる処
理異状現象の発生が減り、処理を安定化することができ
る。The function of the activated sludge pretreatment of the present invention is unnecessary in the conventional activated sludge method, and excess surplus sludge (return sludge) that has been withdrawn and discarded is used as the reaction sludge as a microbial adsorbent, thereby making it difficult to decompose in the raw raw water. Substances, such as bactericides that adsorb activated sludge to damage activated sludge and substances that adversely affect microorganisms such as strong acid and strong alkali, are selectively adsorbed to the reaction sludge, and the sludge is removed from the system. In order to remove the activated sludge, the activated sludge is prevented from being damaged and the activated sludge is kept in a high activity state, so that the activated sludge is prevented from swelling and the occurrence of abnormal processing phenomenon due to foam scum, and the processing can be stabilized.
【0013】さらに発明の作用を詳細に説明すると、反
応汚泥を原水と混合攪拌したあと加圧浮上設備で吸着反
応汚泥を除去すると、原水のpH調整が不用となる。そ
れは微生物の持っているpH緩衝作用により、自然にp
Hの調整が行われるので、酸・アルカリを中和するに必
要な薬剤や設備が不用となるのでその分、敷地が有効に
使用できるのみならず薬品代の節約になる。また、原水
中に活性汚泥に吸着して活性汚泥を破壊する殺菌剤等の
有害物質があっても、反応汚泥が予めこれらを吸着し、
系外に加圧浮上で除去されるので曝気槽の活性汚泥に悪
影響が及ばないため、殺菌剤が排水に混入するところで
も安定な活性汚泥処理が出来る。The operation of the invention will be described in more detail. When the reaction sludge is mixed with the raw water and stirred and then the adsorbed reaction sludge is removed by the pressure flotation equipment, the pH adjustment of the raw water becomes unnecessary. Due to the pH buffering effect of microorganisms, p
Since H is adjusted, the chemicals and equipment necessary for neutralizing acids and alkalis are not needed, so not only can the site be used effectively, but the cost of chemicals can be saved. In addition, even if there is a harmful substance such as a bactericide that adsorbs to the activated sludge and destroys the activated sludge in the raw water, the reaction sludge adsorbs these in advance,
Since it is removed by pressure floatation outside the system, it does not adversely affect the activated sludge in the aeration tank, so stable activated sludge treatment can be performed even when bactericide is mixed in the wastewater.
【0014】本発明では活性汚泥処理を2系列平行処理
することにより、活性汚泥処理設備設置面積を小さく取
ることが出来る。つまり、通常の汚泥濃度の活性汚泥処
理(通常活性汚泥処理槽)と通常の約10倍の濃厚な活
性汚泥処理(濃厚汚泥消化槽)とを並列に運転して、全
体的には効率よく排水処理が出来る。そのため、既存設
備の排水処理能力を3倍程度まで向上を計るときに、原
水反応槽と加圧浮上設備を曝気槽上部に据えつけ、濃厚
汚泥消化槽を既存の曝気槽ないしは原水調整槽の一部を
仕切って作り、必要に応じて最終沈澱槽を大きくするこ
とにより、既設の活性汚泥処理設備の処理能力を狭い敷
地面積でも増強できる。In the present invention, the activated sludge treatment equipment can be installed in a small installation area by performing two series of parallel treatments. In other words, the activated sludge treatment with a normal sludge concentration (normal activated sludge treatment tank) and the activated sludge treatment with a concentration about 10 times the normal concentration (concentrated sludge digestion tank) are operated in parallel to efficiently drain the water as a whole. Can be processed. Therefore, when the wastewater treatment capacity of the existing equipment is to be improved to about 3 times, the raw water reaction tank and the pressure flotation equipment are installed above the aeration tank, and the thick sludge digestion tank is installed in the existing aeration tank or raw water adjustment tank. By dividing the parts into parts and enlarging the final settling tank if necessary, the treatment capacity of the existing activated sludge treatment equipment can be increased even in a small site area.
【0015】都市部では下水道放流が進行してきたがそ
の簡易処理として本発明は有利に作用する。下水道放流
の場合は油脂分に対する規制が厳しいが、SS(懸濁固
形分濃度)はそれぞれの市町村で異なるが比較的高いの
で、放流基準に見合った水質に通常活性汚泥処理槽から
の放流水と濃厚汚泥消化槽からの消化汚泥とを混合し
て、放流基準値に適合した水質に自動的に調整して放流
しやすいので、活性汚泥による簡易処理費用の削減にも
役立つ。Sewerage discharge has progressed in urban areas, but the present invention advantageously works as a simple treatment. In the case of sewage discharge, regulations on oil and fat are strict, but SS (suspended solids concentration) is different depending on each municipality, but it is relatively high, so the water quality that meets the discharge standard is usually the same as the discharged water from the activated sludge treatment tank. Since it is easy to mix with the digested sludge from the thick sludge digestion tank and automatically adjust the water quality to meet the discharge standard value for discharge, it is also useful for reducing the simple treatment cost of activated sludge.
【0016】以下本発明を具体的に、実施例ならびに比
較例を挙げて対比しながら説明するが、本発明をここに
述べる実施例に限定するものではない。Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the Examples described herein.
【0017】[0017]
【比較例】食肉加工を主体とした食品製造工場から平均
水量650m3/日の排水を活性汚泥処理を行っている施
設がある。流入原水の年平均水質は、BODが780p
pm、COD350ppm、SS250ppmそしてn
−ヘキサン抽出成分が85ppmであり、燻製炉のアル
カリ洗浄液や食品加工工場での殺菌剤が含まれている。
この施設は流入原水を油分離槽で油脂分を浮上分離させ
たのち、ウエッジワイヤー型の目開きが1mmのスクリー
ンで粗大塵を除去して、原水調整槽に原水を貯溜し、ポ
ンプで汲み上げて原水計量槽で平均27m3/時に調整し
て、返送汚泥と混合して押し出し流れの活性汚泥曝気槽
容積350m3 で曝気処理したのち水面積が64m2 の
沈降槽2池を並列に使用して活性汚泥から処理水を分離
して放流水を取り出し、沈降濃縮された活性汚泥は返送
汚泥として循環使用し、一部を余剰汚泥として抜き出し
て凝集脱水し、脱水ケーキが得られ、これを場外処分し
ていた。[Comparative Example] There is a facility where activated sludge treatment is performed on wastewater with an average water volume of 650 m 3 / day from a food manufacturing factory mainly for processing meat. Annual average water quality of inflowing raw water is BOD of 780p
pm, COD350ppm, SS250ppm and n
-Hexane extraction component is 85ppm, and contains alkaline cleaning liquid for smoking furnace and bactericide in food processing plant.
In this facility, after the inflowing raw water is floated and separated by an oil separation tank, coarse dust is removed by a wedge wire type screen with a 1 mm opening, and the raw water is stored in a raw water adjusting tank and pumped up by a pump. The average amount of raw water is adjusted to 27 m 3 / hour in the raw water metering tank, mixed with the return sludge and subjected to aeration treatment with the activated sludge aeration tank volume of 350 m 3 of the extrusion flow, and then two sedimentation tanks with a water area of 64 m 2 are used in parallel. The treated water is separated from the activated sludge, the discharged water is taken out, and the activated sludge that has been settled and concentrated is circulated and used as return sludge, and a part of it is extracted as excess sludge for coagulation dehydration to obtain a dehydrated cake, which is disposed off-site. Was.
【0018】本施設では曝気槽にスファエロチリスやタ
イプ021N糸状細菌が異常繁殖して、バルキングを引
き起こし処理出来ない状態が時々発生した。また、原水
のpHが11を超えることがあるので硫酸で中和してか
ら曝気槽に入れていた。At this facility, Sphaerotilis and type 021N filamentous bacteria abnormally propagated in the aeration tank, causing bulking, which sometimes caused a state in which treatment could not be performed. Further, since the pH of raw water may exceed 11, the raw water was neutralized with sulfuric acid before being placed in the aeration tank.
【0019】さらに、余剰汚泥の凝集脱水をおこなうに
当たり、凝集状態が毎日工場の生産品目により異なり、
一定になりにくい。バルキング発生時には予備の沈降槽
を用いて運転するが、汚泥がここにも多量に溜まるので
最大脱水能力でおこなっても足らないと返送汚泥として
循環するが原水流入量を一時的に減少させざるをえない
状態がしばしば発生した。Furthermore, when performing coagulation dehydration of excess sludge, the coagulation state varies daily depending on the production items of the factory,
It is hard to be constant. When a bulking occurs, it operates using a spare settling tank, but since a large amount of sludge accumulates here as well, it will circulate as return sludge if the maximum dehydration capacity is not enough, but the inflow of raw water must be temporarily reduced. Frequent situations often occurred.
【0020】余剰汚泥の引き抜き量は、沈降槽で圧密性
が増さず返送汚泥が月平均で3500ppmであるため
月平均1110m3 であり、日平均37m3 と比較的多
く、脱水機の稼働時間が月平均で19時間/日と長くな
り、凝集剤の添加量は余剰汚泥に対して多少添加量は減
らせるが脱水機の稼働時間が長いので、固形分の重量当
たりの高分子凝集剤の月平均ではカチオン系高分子凝集
剤が2.5%でアニオン系高分子凝集剤が0.7%と添
加率が多いので、凝集剤の月平均使用量はカチオン系高
分子凝集剤が98Kg/月でアニオン系高分子凝集剤が
27Kg/月であった。また、脱水機から排出される脱
水ケーキの含水率は月平均値が86%と比較的高いた
め、脱水ケーキが未分解物質を多く含むので、それが腐
敗して悪臭を発するため、その処分に困っていた。さら
に脱水ケーキ中に含水量が多いため、脱水ケーキの発生
量が月平均29トンと多く、汚泥の処分費用がばかにな
らなかった。特に含水率が85%を超えた場合は汚泥の
引き取りに問題が発生した。The amount of excess sludge drawn out is 1110 m 3 per month on average because the compaction in the settling tank does not increase and the returned sludge is 3500 ppm on average per month, which is 37 m 3 on average per day, which is a relatively large operating time of the dehydrator. The monthly average is as long as 19 hours / day, and the addition amount of the coagulant can be reduced to some extent with respect to the excess sludge, but the operating time of the dehydrator is long. On a monthly average, the cationic polymer flocculant is 2.5% and the anionic polymer flocculant is 0.7%, which is a large addition rate, so the monthly average amount of the flocculant used is 98 kg / kg of the cationic polymer flocculant. The amount of the anionic polymer coagulant was 27 kg / month. In addition, the water content of the dehydrated cake discharged from the dehydrator is relatively high with a monthly average value of 86%, so the dehydrated cake contains a lot of undecomposed substances, so it decomposes and gives off a bad odor. I was in trouble. Furthermore, since the dehydrated cake has a high water content, the average amount of dehydrated cake generated was as high as 29 tons per month, and the sludge disposal cost was insignificant. Especially when the water content exceeds 85%, there is a problem in collecting sludge.
【0021】[0021]
【実施例】比較例の活性汚泥施設に対して、原水の前処
理をするため8m3 攪拌機付の原水反応槽を原水計量槽
のあとに設け、原水に100部に対して反応汚泥6部を
定量ポンプで連続添加した。そして、無薬注型の加圧浮
上設備KF800(日本アルシー(株)製)を設置して
この混合原水100部に対して無薬注で5Kg/cm2
の加圧水を80部混合循環している部分加圧浮上槽で、
反応汚泥を1.8%に濃縮浮上分離除去して、予め2池
ある沈降槽の内、バルキングに備えて設けた予備の沈降
槽を隔壁で2槽に仕切り186m3 の濃厚汚泥消化槽に
改造した。片方の120m3 の槽は攪拌機を付け上部を
密閉し、発生ガスをアルカリ・酸処理してガス回収し、
もう片方の66m3 の槽は散気管と攪拌機を設置し、反
応汚泥に吸着した汚濁物質を嫌気処理並びに好気曝気処
理して得られた消化汚泥を、濃厚汚泥消化槽の液面を自
動制御で一定に保持するように引き抜き、カチオン系と
アニオン系高分子凝集剤との2液を用いて凝集して、ス
クリュープレス脱水機(日本アルシー(株)製NSP−
300)を用いて脱水した。[Example] In the activated sludge facility of the comparative example, a raw water reaction tank with an 8 m 3 stirrer was installed after the raw water measuring tank to pretreat the raw water, and 6 parts of the reaction sludge was added to 100 parts of the raw water. Continuous addition was performed with a metering pump. A chemical-free injection type pressure levitation facility KF800 (manufactured by Alcy Japan Co., Ltd.) was installed and 100 kg of this mixed raw water was 5 kg / cm 2 without chemical injection.
In a partial pressure flotation tank in which 80 parts of pressurized water is mixed and circulated,
Reactive sludge was concentrated and floated to 1.8%, removed, and separated from the settling tanks that were prepared in advance for bulking by dividing the two settling tanks into two tanks by dividing them into a 186 m 3 thick sludge digestion tank. did. One of the 120 m 3 tanks was equipped with a stirrer and the top was sealed, and the generated gas was treated with alkali and acid to recover the gas.
The other 66 m 3 tank is equipped with an air diffuser and a stirrer, and the digested sludge obtained by anaerobic and aerobic aeration of the pollutants adsorbed in the reaction sludge is automatically controlled by the liquid level of the thick sludge digestion tank. With a screw press dehydrator (NSP-manufactured by Nippon Alsee Co., Ltd.).
300) and dehydrated.
【0022】一方無薬注加圧浮上設備で得られた処理水
は、比較例と同様に活性汚泥処理槽と沈降槽を用いて処
理して放流水を得た。しかしこの場合は比較例のときに
常時発生していたスファエロチリスやタイプ021N糸
状細菌はほとんど見られなくなり、沈降槽で汚泥の濃縮
性が改良され返送汚泥濃度が6000ppmを超えるよ
うになったので返送率を100%で運転してMLSSを
3300ppmを維持して運転したところ活性汚泥処理
が良好となった。そのため、沈降槽を1池減らしたが全
く心配する必要がなかった。On the other hand, the treated water obtained in the chemical-free injection pressure flotation equipment was treated using an activated sludge treatment tank and a sedimentation tank in the same manner as in Comparative Example to obtain discharged water. However, in this case, Sphaerotilis and type 021N filamentous bacteria that were constantly generated in the comparative example were hardly seen, sludge concentration was improved in the settling tank, and the returned sludge concentration exceeded 6000 ppm. Was operated at 100% to maintain MLSS at 3300 ppm, the activated sludge treatment was satisfactory. Therefore, we reduced the number of sedimentation tanks by one, but there was no need to worry at all.
【0023】加圧浮上で月平均で約1.8%に浮上濃縮
された汚濁物質を吸着した反応汚泥は月平均で13トン
/日発生し、これを沈降槽を改良した濃厚汚泥消化槽で
消化した。消化槽で反応汚泥の滞留日数は約14日ある
ため、反応汚泥が吸着した難分解性物質や油脂分や天然
高分子などは消化が進行して、菌体への転換が大幅に進
行した。そのため月平均の消化汚泥引き抜き量はで9ト
ン/日であり、固形分換算量では0.17トン/日であ
り、脱水機の月平均稼働時間は5時間/日と比較例の場
合の約1/4になった。凝集剤の使用量はカチオン系高
分子凝集剤が42Kg/月でアニオン系高分子凝集剤が
17Kg/月と比較例と比較すると約半分程度と少なく
なった。脱水ケーキの含水率は月平均で81%と大幅に
減少したのみならず脱水ケーキの臭気が比較例に比べて
減少したため消臭剤を使用する必要が無くなった。発生
した脱水ケーキ量は月平均で14トン/月と比較例に対
して半分以下になった。The reaction sludge that adsorbed the contaminants floated and concentrated to about 1.8% on a monthly average by pressure flotation generated 13 tons / day on a monthly average, and this was generated in a thick sludge digestion tank with an improved settling tank. Digested. Since the reaction sludge stays in the digestion tank for about 14 days, the indigestible substances, fats and oils, natural polymers, etc. adsorbed by the reaction sludge were digested, and the conversion to bacterial cells was significantly progressed. Therefore, the monthly average digested sludge removal rate is 9 tons / day, and the solid conversion rate is 0.17 tons / day, and the monthly average operating time of the dehydrator is 5 hours / day, which is about the same as in the comparative example. It became 1/4. The amount of the flocculant used was 42 kg / month for the cationic polymer flocculant and 17 kg / month for the anionic polymer flocculant, which was about half that of the comparative example. The water content of the dehydrated cake was drastically reduced to 81% on a monthly average, and the odor of the dehydrated cake was reduced compared to the comparative example, so that it was not necessary to use a deodorant. The amount of dehydrated cake generated was 14 tons / month on average, which was less than half that of the comparative example.
【0024】また、脱水ケーキの臭気が減ったので乾燥
して肥料として検討したところ、完熟菌体肥料のみなら
ず土壌改良剤として有効利用できることが分かった。Since the odor of the dehydrated cake was reduced, the dehydrated cake was dried and examined as a fertilizer, and it was found that it can be effectively used not only as a mature fertilizer but also as a soil conditioner.
【0025】[0025]
【発明の効果】本発明により得られた効果は、排水処理
が水に溶解している汚濁物質を固形分やガスとして回収
する技術であるが、回収したこれらの固形分が産業廃棄
物として地球環境問題を引き起こさないようにしなけれ
ばならないという観点からすると、回収固形分量を減ら
しさらに有効な資源として使用する方法を容易に提供出
来ることは優れた効果である。The effect obtained by the present invention is a technology for recovering pollutants dissolved in water as solids or gas in wastewater treatment, and these recovered solids are used as industrial wastes on the earth. From the viewpoint of not causing environmental problems, it is an excellent effect that the amount of recovered solids can be reduced and a method of using it as an effective resource can be easily provided.
【0026】また、従来の活性汚泥処理では、流入原水
の有機分濃度とその種類が一定でなく大幅に変動したり
活性汚泥に対する有害物質が時々流入したりすると活性
汚泥の細菌にたいして、大きな障害を与え、水質の悪化
を引き起こしたり、糸状細菌によるバルキングの発生に
より処理不能現象を呈したりしやすい。このような原廃
水を処理している処理場では本発明により、流入原水中
の汚濁物質のうち活性汚泥に悪影響を与える成分を予め
原水に対して反応汚泥量の供給割合を調節し、活性汚泥
に接触吸着させて除去する事により、原水の水質が任意
にそして容易に調整できるので、活性汚泥処理を安定し
て行えるようになり活性汚泥処理後の水質が安定化し、
かつバルキングの発生頻度が著しく減少する。さらに、
排水処理場の占有敷地に限度があり、流入原水の有機分
負荷が高く曝気槽で処理できそうにない場合に、本発明
は有機分負荷を曝気槽と濃厚汚泥消化槽に分散させて並
列処理するため、絶対的な活性汚泥保有量を同一面積で
も5から10倍多く取れ、微生物処理能力がその割合で
大きく取ることが出来るので、優れた効果を発揮でき
る。これは活性汚泥処理法の優れた2つの次に述べる長
所を組み合わせたために得られた。その一つが活性汚泥
処理では固液分離が活性汚泥濃度が薄ければ薄いほどし
やすいことを利用して、通常の活性汚泥処理設備を有機
分負荷を軽くして低濃度の活性汚泥で処理すること、そ
して二つ目は固液分離を必要としない場合は有機分濃度
並びに活性汚泥濃度は高ければ高いほど消化能力が高い
ので、反応汚泥に有機分を高濃度に吸着させて加圧浮上
設備で浮上濃縮してから濃厚汚泥消化槽に送ることによ
り、通性嫌気性菌と通性好気性菌とにより、汚泥が吸着
した有機分の消化が効率よく促進され、最終的には悪臭
の少ない完熟の活性汚泥を得やすい。Further, in the conventional activated sludge treatment, if the organic concentration and the type of the inflowing raw water are not constant and greatly fluctuate, or if a harmful substance to the activated sludge sometimes flows in, a serious obstacle is given to the bacteria of the activated sludge. It is apt to cause deterioration of water quality and to cause an unprocessable phenomenon due to occurrence of bulking by filamentous bacteria. According to the present invention, in a treatment plant treating such raw wastewater, components that adversely affect the activated sludge out of the pollutants in the inflowing raw water are adjusted in advance by adjusting the supply ratio of the reaction sludge amount to the raw water. The water quality of the raw water can be adjusted arbitrarily and easily by adsorbing it to and removing it, so that the activated sludge treatment can be performed stably and the water quality after the activated sludge treatment is stabilized,
Moreover, the frequency of occurrence of bulking is significantly reduced. further,
If the occupancy site of the wastewater treatment plant is limited and the influent raw water has a high organic content load and is unlikely to be treated in the aeration tank, the present invention disperses the organic content load in the aeration tank and the thick sludge digestion tank for parallel processing. Therefore, the absolute activated sludge holding amount can be increased by 5 to 10 times even in the same area, and the microbial treatment capacity can be greatly increased in that proportion, so that an excellent effect can be exhibited. This was obtained because of the combination of the two following advantages of the activated sludge treatment method. One of them is that in activated sludge treatment, solid-liquid separation is easier as the concentration of activated sludge is thinner, so that ordinary activated sludge treatment equipment is treated with a low concentration of activated sludge by reducing the organic content load. Secondly, when solid-liquid separation is not required, the higher the concentration of organic components and the concentration of activated sludge, the higher the digestion ability. Floating and concentrating with, and then sending it to the thick sludge digestion tank, facultative anaerobic bacteria and facultative aerobic bacteria efficiently promote the digestion of the organic components adsorbed in the sludge, and finally, there is less foul odor. It is easy to obtain fully-ripened activated sludge.
【0027】廃水処理場の一番の問題点は余剰汚泥処理
である。通常余剰汚泥を引き抜き凝集脱水しているが、
余剰汚泥中に未分解有機分濃度が高いと微生物分解の長
所である有機分を無機分(炭酸ガスと水)に変換してな
いのでその分廃棄汚泥量が増加するのみならず凝集剤の
使用量が増大したり凝集状態が未分解物質の種類に大き
く左右され不安定になり、脱水機の能力を著しく損なっ
たり、脱水ケーキの含水率が上昇したりして著しく経済
効果を損なうが、本発明は濃厚汚泥消化により効率よく
微生物分解を行い未分解物質量が少ないため、汚泥の消
化が進行するため、発生汚泥固形分量が少なく、かつ凝
集脱水するに当たり凝集剤消費量が少なくて安定で良好
な凝集が得られるため脱水機の脱水効率が上がり、得ら
れた脱水ケーキの含水率が低いため脱水ケーキ量が少な
いのみならず腐敗しにくいので悪臭の発生が少ないため
作業環境問題が少ない。また、有害物の混入が少なく肥
料としての適性が有る場合は完熟有機肥料としてまた土
壌改良剤として有効な地球資源として還元して経済効果
を出すことが出来る。従って、本発明は廃水処理に伴っ
て発生する産業廃棄物量が少なく、流入原水に有害物質
を含まぬ場合は有効な資源として活用できる状態の汚泥
になるので環境破壊が少なくかつ地球に優しい廃水処理
方法を提供できる。The most problematic point of the wastewater treatment plant is the treatment of excess sludge. Usually, excess sludge is pulled out and coagulated and dehydrated,
If the undegraded organic matter concentration in the excess sludge is high, the organic matter, which is an advantage of microbial decomposition, is not converted to inorganic matter (carbon dioxide gas and water), so not only the amount of waste sludge increases but also the use of coagulant. The amount increases or the agglomeration state is greatly affected by the type of undecomposed substance and becomes unstable, which significantly impairs the performance of the dehydrator and increases the water content of the dehydrated cake, which significantly impairs the economic effect. The invention efficiently decomposes microbial cells by digesting concentrated sludge and has a small amount of undecomposed substances, so that the digestion of sludge progresses, the solid content of generated sludge is small, and the coagulant consumption is small and stable for coagulation and dehydration. The dewatering efficiency of the dewatering machine is improved due to the high coagulation, and the water content of the obtained dewatering cake is low. There. In addition, when it contains little harmful substances and is suitable as a fertilizer, it can be returned as a fully-ripened organic fertilizer and as a global resource effective as a soil conditioner, thereby producing an economic effect. Therefore, according to the present invention, the amount of industrial waste generated by wastewater treatment is small, and when the inflowing raw water does not contain harmful substances, it becomes sludge that can be utilized as an effective resource, so there is little environmental destruction and earth-friendly wastewater treatment. A method can be provided.
Claims (1)
当たり、予め原水100部にたいして返送汚泥(反応汚
泥)を1から30部好ましくは3から15部を混合攪拌
したのち、反応汚泥を加圧浮上濃縮分離して、0.5%
以上好ましくは2%以上の固形分を含む汚泥(吸着濃縮
反応汚泥)と処理原水とを得る。処理原水は、活性汚泥
曝気槽で返送汚泥といっしょに曝気処理後固液分離し
て、最終放流水と返送汚泥とを得る。吸着濃縮反応汚泥
は、濃厚汚泥消化槽で嫌気・好気消化し、反応汚泥が吸
着した汚濁物質は微生物分解して、消化汚泥を得る。そ
して、余剰汚泥として消化汚泥を引き抜き除去する活性
汚泥処理方法。1. When treating pollutants in raw water with activated sludge, 1 to 30 parts, preferably 3 to 15 parts, of returned sludge (reactive sludge) is mixed and stirred in advance with respect to 100 parts of raw water, and then the reaction sludge is pressurized. Float concentration and separation, 0.5%
More preferably, sludge containing 2% or more of solid content (adsorption / condensation reaction sludge) and treated raw water are obtained. The treated raw water is subjected to aeration treatment together with the returned sludge in the activated sludge aeration tank and then solid-liquid separated to obtain final discharged water and returned sludge. The adsorption-concentration reaction sludge is anaerobically and aerobically digested in a concentrated sludge digestion tank, and the pollutants adsorbed by the reaction sludge are microbially decomposed to obtain digested sludge. Then, an activated sludge treatment method of extracting and removing digested sludge as excess sludge.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP24660691A JP3164850B2 (en) | 1991-08-31 | 1991-08-31 | Activated sludge treatment method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP24660691A JP3164850B2 (en) | 1991-08-31 | 1991-08-31 | Activated sludge treatment method |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH06315695A true JPH06315695A (en) | 1994-11-15 |
JP3164850B2 JP3164850B2 (en) | 2001-05-14 |
Family
ID=17150912
Family Applications (1)
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JP24660691A Expired - Lifetime JP3164850B2 (en) | 1991-08-31 | 1991-08-31 | Activated sludge treatment method |
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JP (1) | JP3164850B2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010264424A (en) * | 2009-05-18 | 2010-11-25 | Kobelco Eco-Maintenance Co Ltd | Organic wastewater treatment facility and method for operating the same |
JP2016172237A (en) * | 2015-03-17 | 2016-09-29 | 水ing株式会社 | Apparatus and method for treating water |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4142410B2 (en) * | 2002-11-19 | 2008-09-03 | 日本アルシー株式会社 | Wastewater treatment method |
-
1991
- 1991-08-31 JP JP24660691A patent/JP3164850B2/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010264424A (en) * | 2009-05-18 | 2010-11-25 | Kobelco Eco-Maintenance Co Ltd | Organic wastewater treatment facility and method for operating the same |
JP2016172237A (en) * | 2015-03-17 | 2016-09-29 | 水ing株式会社 | Apparatus and method for treating water |
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