JP6133190B2

JP6133190B2 - Oil removal device and oil removal method for oil-containing wastewater

Info

Publication number: JP6133190B2
Application number: JP2013211958A
Authority: JP
Inventors: 祐介酒井; 香織根本; 雅広能勢
Original assignee: 菱冷環境エンジニアリング株式会社
Priority date: 2013-10-09
Filing date: 2013-10-09
Publication date: 2017-05-24
Anticipated expiration: 2033-10-09
Also published as: JP2015073945A

Description

本発明は、油分や懸濁物質を含有する様々な廃水から、その油分や懸濁物質を凝集させて分離することによって、廃水中の油分や懸濁物質を除去する装置および方法に関するものである。 The present invention relates to an apparatus and method for removing oil and suspended solids from waste water by agglomerating and separating the oil and suspended solids from various wastewaters containing oil and suspended solids. .

各種の食材を加工する食品工場、衣服を洗濯するクリーニング工場、あるいは工作機械を用いて金属製品の製作や補修を行なう金属加工工場（たとえばダイカストを扱う金型工場等）、化学製品の製作や成形を行なう化学工場などから排出される廃水には、植物性油、動物性油、鉱物油、化学物質など種々の油分が含まれている。さらに、それぞれの工場における処理工程で発生する様々な非水溶性の微細粒子（以下、懸濁物質という）も廃水に混入した状態で工場から排出される。 Food factories that process various ingredients, cleaning factories that wash clothes, metal processing factories that manufacture and repair metal products using machine tools (for example, die factories that handle die casting), chemical product manufacturing and molding The waste water discharged from chemical factories and the like that contain a variety of oils such as vegetable oils, animal oils, mineral oils, and chemical substances. Furthermore, various water-insoluble fine particles (hereinafter referred to as suspended substances) generated in the processing steps in each factory are also discharged from the factory in a state of being mixed with wastewater.

一般の廃水処理設備では、このような油分や懸濁物質を含有する廃水（以下、含油廃水という）から油分や懸濁物質を除去（以下、油分除去という）することは困難であり、その水処理設備の通常の操業に支障を来す。何故なら、含油廃水に含まれる油分や懸濁物質の成分が多岐にわたっているので、その含油廃水に適した薬剤を選択し、しかも好適な処理条件を設定することが難しいからである。 In general wastewater treatment facilities, it is difficult to remove oil and suspended solids (hereinafter referred to as oil removal) from wastewater containing such oil and suspended solids (hereinafter referred to as oil-containing wastewater). It interferes with the normal operation of the processing equipment. This is because it is difficult to select chemicals suitable for the oil-containing wastewater and to set suitable treatment conditions because there are a wide variety of components of oil and suspended substances contained in the oil-containing wastewater.

そこで、工場から排出された含油廃水を一般の廃水処理設備へ供給する前に、油分除去を行なうための技術が検討されている。
たとえば特許文献１には、pHおよび温度を所定の範囲に調整した含油廃水に、高カチオン系高分子凝集剤を添加し、油分や懸濁物質を固化して微細なフロックとし、それを凝集させたスカムをスクリーンフィルターで濾過することによって油分除去を行なう技術が開示されている。この技術は、高カチオン系高分子凝集剤を用いて所定のpHや温度で凝集しない油分や懸濁物質を除去することは不可能であり、それらの油分や懸濁物質が残留した含油廃水を一般の廃水処理設備で処理できないという問題が生じる。 Therefore, a technique for removing oil before the oil-containing wastewater discharged from the factory is supplied to a general wastewater treatment facility has been studied.
For example, in Patent Document 1, a highly cationic polymer flocculant is added to oil-containing wastewater whose pH and temperature are adjusted to a predetermined range, and oil and suspended substances are solidified to form fine flocs, which are then aggregated. A technique for removing oil by filtering the scum through a screen filter is disclosed. With this technology, it is impossible to remove oil and suspended substances that do not aggregate at a predetermined pH and temperature using a high cationic polymer flocculant. There arises a problem that it cannot be treated with a general wastewater treatment facility.

その問題を解消するためには、高カチオン系高分子凝集剤に加えて他の凝集剤を併用せざるを得ず、その凝集剤に応じて含油廃水のpHや温度を調整しなければならないので、使用する凝集剤ごとに油分除去を行なう一連の設備を保有する必要がある。つまり特許文献１に開示された技術では、多岐にわたる成分の油分除去を行なうためには、多大な設備費と広大な敷地を要する。 In order to solve the problem, in addition to the high cationic polymer flocculant, other flocculants must be used together, and the pH and temperature of the oil-containing wastewater must be adjusted according to the flocculant. It is necessary to have a series of facilities for removing oil for each coagulant used. That is, with the technique disclosed in Patent Document 1, a large facility cost and a large site are required to remove oil components from a wide variety of components.

特許文献２には、含油廃水に高分子凝集剤を添加した後、曲がった流路に含油廃水を誘導してスカムを分離する技術が開示されている。この技術は、高分子凝集剤を添加する前に含油廃水を計量する手段を備えていないので、含油廃水の流量が不安定で、高分子凝集剤の濃度が変動し易く、油分除去の精度は安定しない。
つまり、高分子凝集剤の濃度が低すぎる場合は、油分や懸濁物質を十分に凝集させることができず、スカム回収ホッパーを用いてスカムを回収しても、油分や懸濁物質が残留した含油廃水を一般の廃水処理設備へ供給することになるという問題が生じる。また、高分子凝集剤の濃度が高すぎる場合には、余剰の高分子凝集剤が残留した含油廃水を一般の廃水処理設備へ供給することになるという問題が生じることに加え、未反応の高分子凝集剤が残留するので、スクリーンフィルターの目詰まりやスクリーンフィルターへの付着等によって分離操作に問題が生じる。 Patent Document 2 discloses a technique of separating scum by adding a polymer flocculant to oil-containing wastewater and then guiding the oil-containing wastewater into a curved channel. Since this technology does not have means for measuring oil-containing wastewater before adding the polymer flocculant, the flow rate of the oil-containing wastewater is unstable, the concentration of the polymer flocculant is likely to fluctuate, and the accuracy of oil removal is Not stable.
In other words, if the concentration of the polymer flocculant is too low, the oil and suspended solids cannot be sufficiently agglomerated, and even if the scum is collected using the scum collecting hopper, the oil and suspended solids remain. There arises a problem that oil-containing wastewater is supplied to a general wastewater treatment facility. In addition, when the concentration of the polymer flocculant is too high, there arises a problem that the oil-containing wastewater in which the excess polymer flocculant remains is supplied to a general wastewater treatment facility. Since the molecular flocculant remains, problems arise in the separation operation due to clogging of the screen filter, adhesion to the screen filter, and the like.

したがって特許文献２に開示された技術は、含油廃水に添加する高分子凝集剤の割合を安定させ、含油廃水から油分と懸濁物質を十分に除去し、しかも高分子凝集剤を残留させず過不足なく使用するという観点から改善の余地が残されていた。 Therefore, the technique disclosed in Patent Document 2 stabilizes the ratio of the polymer flocculant added to the oil-containing wastewater, sufficiently removes oil and suspended substances from the oil-containing wastewater, and does not leave the polymer flocculant. There was room for improvement from the point of view of using it without a shortage.

特許第3973570号公報Japanese Patent No. 3973570 特開2010-29813号公報JP 2010-29813 A

本発明は、従来技術の問題を解消し、高分子凝集剤を過不足なく使用し、しかも簡素でかつコンパクトな設備を用いて含油廃水の油分除去を十分に行なうことができる油分除去装置および油分除去方法を提供することを目的とする。 The present invention eliminates the problems of the prior art, uses a polymer flocculant without excess and deficiency, and can sufficiently remove the oil content of oil-containing wastewater using a simple and compact facility, and an oil content removal apparatus and oil content An object is to provide a removal method.

本発明者は、含油廃水の油分除去を行なう際に高分子凝集剤を添加する技術について検討し、
(a)高分子凝集剤を水に溶解して含油廃水に添加する、
(b)高分子凝集剤を添加する前に含油廃水を計量して、含油廃水の流量を調整する
ことに加え、高分子凝集剤を溶解した水（以下、凝集剤溶解水という）の添加量を調整することにより、凝集剤溶解水と含油廃水との混合水における凝集剤溶解水の割合を安定させ、ひいては含油廃水に対する高分子凝集剤の割合を安定させることができるという知見を得た。これらを自動化するために、混合水より分離された処理水の濁度を計測し、濁度が所定の数値以下となるよう高分子凝集剤の混合割合を自動で調整することで安定した処理水が得られることが分かった。 The present inventor examined a technique for adding a polymer flocculant when removing oil from oil-containing wastewater,
(a) The polymer flocculant is dissolved in water and added to the oil-containing wastewater.
(b) Before adding the polymer flocculant, weigh the oil-containing wastewater to adjust the flow rate of the oil-containing wastewater, and the amount of water in which the polymer flocculant is dissolved (hereinafter referred to as flocculant-dissolved water) It was found that the ratio of the flocculant-dissolved water in the mixed water of the flocculant-dissolved water and the oil-containing wastewater can be stabilized by adjusting the ratio of the polymer flocculant to the oil-containing wastewater. In order to automate these, the turbidity of the treated water separated from the mixed water is measured, and the treatment rate is stabilized by automatically adjusting the mixing ratio of the polymer flocculant so that the turbidity is below a predetermined value. Was found to be obtained.

次いで、凝集剤溶解水と含油廃水との混合水について詳細に調査し、
(c)混合水から分離したスカムに混合水が付着あるいは浸透している、
(d)上記(c)のスカムに付着、浸透した混合水に未反応の油分や懸濁物質が残留している、
(e)上記(c)のスカムを分離した後の混合水にも油分や懸濁物質が残留している
ことから、混合水を油分除去の処理工程に循環させることによって、高分子凝集剤を過不足なく使用し、油分除去を十分に行なうことが可能であるという知見を得た。 Next, we investigated in detail about the mixed water of flocculant-dissolved water and oil-containing wastewater,
(c) The mixed water adheres to or penetrates the scum separated from the mixed water.
(d) Unreacted oil and suspended solids remain in the mixed water that has adhered to and penetrated the scum of (c) above.
(e) Since the oil and suspended substances remain in the mixed water after separating the scum of (c) above, the polymer flocculant is added by circulating the mixed water to the oil removal treatment step. It was found that it was possible to use the oil without excess and deficiency and to remove the oil sufficiently.

さらに、油分除去の精度が向上することによって、多種類の凝集剤を併用する必要がなく、単一の高分子凝集剤で油分除去が可能となるので、簡素でかつコンパクトな設備を用いて油分除去を行なうことが可能であるという知見を得た。
本発明は、これらの知見に基づいてなされたものである。
すなわち本発明は、油分および懸濁物質を含有する含油廃水を貯留する廃水貯留槽と、高分子凝集剤を水に溶解した凝集剤溶解水を貯留する凝集剤貯留槽と、廃水貯留槽から供給される含油廃水の流量を調整する計量槽と、計量槽から所定流量で供給される含油廃水に凝集剤貯留槽から排出される凝集剤溶解水を添加した混合水を撹拌することによって油分や懸濁物質が固化した微細なフロックの凝集体であるスカムを形成する反応槽と、反応槽から供給される混合水中のスカムを分離する分離槽と、分離槽から供給されるスカムに付着あるいは浸透した混合水を回収する脱水槽と、脱水槽から混合水を廃水貯留槽へ運搬する第１循環配管と、脱水槽から排出されるスカムを貯留するスカム貯留槽と、分離槽から排出される混合水を貯留する混合水貯留槽と、混合水貯留槽から混合水を反応槽へ運搬して反応槽の上方から混合水をスプレーする第２循環配管と、を有する含油廃水の油分除去装置である。 Furthermore, by improving the oil removal accuracy, it is not necessary to use multiple types of flocculants, and it is possible to remove oil with a single polymer flocculant, so the oil content can be reduced using simple and compact equipment. The knowledge that removal is possible was obtained.
The present invention has been made based on these findings.
That is, the present invention provides a wastewater storage tank that stores oil-containing wastewater containing oil and suspended substances, a flocculant storage tank that stores a flocculant-dissolved water obtained by dissolving a polymer flocculant in water, and a supply from the wastewater storage tank. Oil and waste water by agitating mixed water in which the flocculant dissolved water discharged from the flocculant storage tank is added to the oil-containing wastewater supplied at a predetermined flow rate from the measuring tank. Adhered or infiltrated into the reaction tank that forms scum, which is an aggregate of fine flocs solidified by turbid substances, the separation tank that separates the scum in the mixed water supplied from the reaction tank, and the scum supplied from the separation tank A dewatering tank for collecting mixed water, a first circulation pipe for transporting mixed water from the dewatering tank to a waste water storage tank, a scum storage tank for storing scum discharged from the dehydration tank, and a mixed water discharged from the separation tank Store And if water reservoir is oil removal device oil-containing wastewater having a second circulation pipe for spraying, a mixed water from above the then transported to the reaction vessel reaction tank mixed water from the mixing water reservoir.

本発明の油分除去装置においては、凝集剤貯留槽が、凝集剤溶解水中の高分子凝集剤の濃度を0.2質量％以上かつ凝集剤溶解水の粘度を300mPa・s以上に保つものであることが好ましい。また、計量槽が、反応槽に供給される前記含油廃水の流量を５〜100ｍ³／hrに保つものであることが好ましい。また、反応槽が、混合水を撹拌するための曝気装置または撹拌装置を有することが好ましい。 In the oil content removal apparatus of the present invention, the flocculant storage tank may maintain the concentration of the polymer flocculant in the flocculant-dissolved water at 0.2% by mass or more and the viscosity of the flocculant-dissolved water at 300 mPa · s or greater. preferable. Moreover, it is preferable that a measurement tank keeps the flow volume of the said oil-containing wastewater supplied to a reaction tank at 5-100 m < ³ > / hr. Moreover, it is preferable that a reaction tank has an aeration apparatus or a stirring apparatus for stirring mixed water .

さらに、廃水貯留槽から計量槽に含油廃水を供給する廃水配管にラインミキサーを配設して、ラインミキサーに凝集剤貯留槽から凝集剤溶解水を供給することが好ましい。そのラインミキサーは、含油廃水に凝集剤溶解水を添加しながら流通させることによって混合水中でスカムが浮遊するスラリー状流体とするものであり、スラリー状流体をラインミキサーから分離槽へ運搬するスラリー配管を有することが好ましい。あるいは、混合水貯留槽の流出部に濁度測定装置を設置し、混合水より分離された処理水の濁度を計測し、処理水の濁度の測定値が所定の数値以下となるように高分子凝集剤の混合割合を自動で調整することが好ましい。 Furthermore, it is preferable to arrange a line mixer in a waste water pipe for supplying oil-containing waste water from the waste water storage tank to the metering tank, and to supply the flocculant dissolved water from the flocculant storage tank to the line mixer. The line mixer is a slurry-like fluid in which the scum floats in the mixed water by circulating the oil-containing wastewater while adding the flocculant-dissolved water, and the slurry pipe that conveys the slurry-like fluid from the line mixer to the separation tank It is preferable to have. Alternatively, a turbidity measurement device is installed at the outflow part of the mixed water storage tank, and the turbidity of the treated water separated from the mixed water is measured, so that the measured value of the turbidity of the treated water is below a predetermined value. It is preferable to automatically adjust the mixing ratio of the polymer flocculant.

また本発明は、油分および懸濁物質を含有する含油廃水を廃水貯留槽に貯留するとともに、高分子凝集剤を水に溶解した凝集剤溶解水を凝集剤貯留槽に貯留し、廃水貯留槽から供給される含油廃水の流量を計量槽で調整しながら反応槽へ供給し、かつ反応槽へ凝集剤貯留槽から凝集剤溶解水を供給して、反応槽内で含油廃水に凝集剤溶解水を添加した混合水を撹拌することによって油分や懸濁物質が固化した微細なフロックの凝集体であるスカムを形成し、反応槽から供給される混合水中のスカムを分離槽で分離し、次いで分離槽から供給されるスカムに付着あるいは浸透した混合水を脱水槽で回収し、脱水槽から混合水を廃水貯留槽へ第１循環配管を用いて運搬する一方で、脱水槽から排出されるスカムをスカム貯留槽に貯留し、さらに分離槽から排出される混合水を混合水貯留槽に貯留し、混合水貯留槽から混合水を反応槽へ第２循環配管を用いて運搬して反応槽の上方から混合水をスプレーする含油廃水の油分除去方法である。 Further, the present invention stores oil-containing wastewater containing oil and suspended solids in a wastewater storage tank, stores flocculant-dissolved water obtained by dissolving a polymer flocculant in water in the flocculant storage tank, Supply the oil-containing wastewater to the reaction tank while adjusting the flow rate of the oil-containing wastewater in the measuring tank, and supply the flocculant-dissolved water from the flocculant storage tank to the reaction tank. By stirring the added mixed water, a scum that is an aggregate of fine flocs solidified with oil and suspended solids is formed, and the scum in the mixed water supplied from the reaction tank is separated in the separation tank, and then the separation tank The mixed water adhering to or penetrating the scum supplied from the tank is collected in the dehydration tank, and the mixed water is transported from the dehydration tank to the waste water storage tank using the first circulation pipe, while the scum discharged from the dewatering tank is scum Store in the storage tank Storing the mixed water discharged from the tank to the mixing water storage tank, from the mixing water storage tank mixing water to the reaction vessel of the oil-containing wastewater of spraying the mixed water from the top of the reaction vessel and transported using a second circulation pipe This is an oil removal method.

本発明の油分除去方法においては、凝集剤貯留槽にて、凝集剤溶解水中の高分子凝集剤の濃度を0.2質量％以上かつ凝集剤溶解水の粘度を300mPa・s以上に保つことが好ましい。また、計量槽にて、反応槽に供給される含油廃水の流量を５〜100ｍ³／hrに保つことが好ましい。また、反応槽にて、曝気装置または撹拌装置を用いて混合水を撹拌することが好ましい。 In the oil removing method of the present invention, it is preferable to maintain the concentration of the polymer flocculant in the flocculant-dissolved water at 0.2% by mass or more and the viscosity of the flocculant-dissolved water at 300 mPa · s or higher in the flocculant storage tank. Moreover, it is preferable to maintain the flow rate of the oil-containing wastewater supplied to the reaction tank at 5 to 100 m ³ / hr in the measuring tank. Moreover, it is preferable to stir the mixed water in the reaction tank using an aeration apparatus or a stirring apparatus .

さらに、廃水貯留槽から計量槽に含油廃水を供給する廃水配管に配設したラインミキサーに、凝集剤貯留槽から凝集剤溶解水を供給することが好ましい。そのラインミキサーにて、含油廃水に凝集剤溶解水を添加しながら流通させることによって混合水中でスカムが浮遊するスラリー状流体とし、スラリー状流体をラインミキサーから分離槽へスラリー配管を用いて運搬することが好ましい。あるいは、混合水貯留槽の流出部に設置した濁度測定装置を用いて、混合水より分離された処理水の濁度を計測し、処理水の濁度の測定値が所定の数値以下となるように高分子凝集剤の混合割合を自動で調整することが好ましい。 Furthermore, it is preferable to supply the flocculant-dissolved water from the flocculant storage tank to a line mixer disposed in a wastewater pipe that supplies oil-containing wastewater from the wastewater storage tank to the metering tank. In the line mixer, the flocculant-dissolved water is added to the oil-containing wastewater and circulated to form a slurry-like fluid in which scum floats in the mixed water, and the slurry-like fluid is transported from the line mixer to the separation tank using slurry piping. It is preferable. Alternatively, the turbidity of the treated water separated from the mixed water is measured using a turbidity measuring device installed in the outflow part of the mixed water storage tank, and the measured value of the turbidity of the treated water becomes a predetermined value or less. Thus, it is preferable to automatically adjust the mixing ratio of the polymer flocculant.

本発明によれば、高分子凝集剤を過不足なく使用し、しかも簡素でかつコンパクトな設備を用いて含油廃水の油分除去を十分に行なうことができるので、産業上格段の効果を奏する。 According to the present invention, the polymer flocculant can be used without excess and deficiency, and the oil content of the oil-containing wastewater can be sufficiently removed using a simple and compact facility.

本発明を適用して含油廃水の油分除去を行なう手順を示すフロー図である。It is a flowchart which shows the procedure which performs the oil removal of oil-containing wastewater by applying this invention. 本発明を適用して含油廃水の油分除去を行なう手順の他の例を示すフロー図である。It is a flowchart which shows the other example of the procedure which applies the present invention and performs oil removal of oil-containing wastewater. 本発明を適用して含油廃水の油分除去を行なう手順の他の例を示すフロー図である。It is a flowchart which shows the other example of the procedure which applies the present invention and performs oil removal of oil-containing wastewater.

図１は、本発明を適用して含油廃水の油分除去を行なう手順を示すフロー図である。食品工場、クリーニング工場、金属加工工場、化学工場等の様々な工場から排出された油分や懸濁物質を含有する含油廃水２は、廃水貯留槽１に貯留される。
一方で、凝集剤貯留槽３には凝集剤溶解水４が貯留される。凝集剤溶解水４は、市販の高分子凝集剤を水（たとえば工業用水、純水、水道水、井戸水等）に溶解した水溶液である。凝集剤溶解水４中の高分子凝集剤の濃度は、0.2質量％以上が好ましい。高分子凝集剤の濃度が0.2質量％未満では、後述するフロックの固化が困難であり、ひいてはスカムの形成が困難になるので、油分の除去やスカムの分離に支障を来す。 FIG. 1 is a flowchart showing a procedure for removing oil content of oil-containing wastewater by applying the present invention. Oil-containing wastewater 2 containing oil and suspended substances discharged from various factories such as a food factory, a cleaning factory, a metal processing factory, and a chemical factory is stored in a wastewater storage tank 1.
On the other hand, the flocculant dissolving water 4 is stored in the flocculant storage tank 3. The flocculant-dissolved water 4 is an aqueous solution in which a commercially available polymer flocculant is dissolved in water (for example, industrial water, pure water, tap water, well water, etc.). The concentration of the polymer flocculant in the flocculant-dissolved water 4 is preferably 0.2% by mass or more. If the concentration of the polymer flocculant is less than 0.2% by mass, it will be difficult to solidify flocs, which will be described later, and it will be difficult to form scum, which will hinder oil removal and scum separation.

また、高分子凝集剤の濃度が高すぎると、後述するスカムの分離を行なった後の混合水に高分子凝集剤が残留し易くなり、スカムの分離および脱水のための機器に目詰まりが生じ、処理が困難になるとともに、高分子凝集剤を除去するための水処理が必要となる。そのため凝集剤溶解水４中の高分子凝集剤の濃度は、0.2〜0.5質量％の範囲内が一層好ましい。 In addition, if the concentration of the polymer flocculant is too high, the polymer flocculant tends to remain in the mixed water after the scum separation described later, and the scum separation and dehydration equipment is clogged. The treatment becomes difficult and a water treatment for removing the polymer flocculant is required. Therefore, the concentration of the polymer flocculant in the flocculant-dissolved water 4 is more preferably in the range of 0.2 to 0.5% by mass.

さらに、凝集剤溶解水４の粘度は、300mPa・s以上が好ましい。凝集剤溶解水４の粘度が300mPa・s未満では、後述するフロックの固化が困難であり、ひいてはスカムの形成が困難になるので、油分除去に支障を来す。また、凝集剤溶解水４の粘度が高すぎると、後述する含油廃水２との混合および撹拌が困難になり、高分子凝集剤による油分や懸濁物質の凝集効果が得られない。そのため凝集剤溶解水４の粘度は、300〜1500mPa・s の範囲内が一層好ましい。 Further, the viscosity of the flocculant-dissolved water 4 is preferably 300 mPa · s or more. If the viscosity of the flocculant-dissolved water 4 is less than 300 mPa · s, it will be difficult to solidify flocs, which will be described later, and it will be difficult to form scum, which will hinder oil removal. On the other hand, if the viscosity of the flocculant-dissolved water 4 is too high, mixing and stirring with the oil-containing wastewater 2 described later becomes difficult, and the agglomeration effect of the oil and suspended substances by the polymer flocculant cannot be obtained. Therefore, the viscosity of the flocculant-dissolved water 4 is more preferably in the range of 300 to 1500 mPa · s.

本発明では、使用する高分子凝集剤の成分は限定せず、高分子凝集剤を水に溶解した凝集剤溶解水４の濃度および粘度が上記の範囲を満足するように、高分子凝集剤の成分と使用量を調整する。つまり凝集剤溶解水４の濃度および粘度が上記の範囲内であれば、単一種類の高分子凝集剤を使用しても良いし、複数種類の高分子凝集剤を適宜配合して併用することも可能である。 In the present invention, the components of the polymer flocculant to be used are not limited, and the concentration and viscosity of the flocculant-dissolved water 4 obtained by dissolving the polymer flocculant in water satisfy the above range. Adjust ingredients and usage. That is, if the concentration and viscosity of the flocculant-dissolving water 4 are within the above ranges, a single type of polymer flocculant may be used, or a plurality of types of polymer flocculants may be appropriately blended and used together. Is also possible.

このように、凝集剤貯留槽３内の凝集剤溶解水４の濃度および粘度を所定の好適範囲に保つために、凝集剤撹拌機５を使用することが好ましい。凝集剤撹拌機５の構成は特に限定しないが、モーターで撹拌翼を回転させるようにすれば、簡素な構成で常時稼働させることが可能であり、かつ間欠運転やインバータ制御による回転数の変更も容易であるから好ましい。 Thus, in order to keep the concentration and viscosity of the flocculant-dissolved water 4 in the flocculant storage tank 3 within a predetermined preferable range, it is preferable to use the flocculant stirrer 5. The configuration of the flocculant stirrer 5 is not particularly limited, but if the stirring blade is rotated by a motor, it can be always operated with a simple configuration, and the rotation speed can be changed by intermittent operation or inverter control. It is preferable because it is easy.

廃水貯留槽１内の含油廃水２は、廃水配管６を経て、計量槽７に常時供給され、さらに反応槽９へ連続的に供給される。計量槽７には堰８が設けられており、その堰８を操作することによって、反応槽９へ連続的に供給される含油廃水２の流量を調整することができる。
反応槽９へ連続的に供給される含油廃水２の流量が少なすぎる場合は、油分除去の作業能率が低下するばかりでなく、後述するスカムの分離を行なった後の混合水に余剰の高分子凝集剤が残留し易くなり、高分子凝集剤を除去するための水処理が必要となる。また、含油廃水２の流量が多すぎる場合は、後述する凝集剤溶解水４との混合および撹拌が不十分になり、高分子凝集剤による油分や懸濁物質の凝集効果が得られない。そのため反応槽９へ連続的に供給される含油廃水２の流量は、５〜100ｍ³／hrの範囲内が好ましい。 The oil-containing wastewater 2 in the wastewater storage tank 1 is always supplied to the measuring tank 7 via the wastewater pipe 6 and is continuously supplied to the reaction tank 9. A weir 8 is provided in the measuring tank 7, and the flow rate of the oil-containing wastewater 2 continuously supplied to the reaction tank 9 can be adjusted by operating the weir 8.
If the flow rate of the oil-containing wastewater 2 continuously supplied to the reaction tank 9 is too small, not only the oil removal work efficiency is lowered, but also excess polymer in the mixed water after the scum separation described later is performed. The flocculant tends to remain, and water treatment is required to remove the polymer flocculant. Moreover, when there is too much flow volume of the oil-containing wastewater 2, mixing and stirring with the coagulant | flocculant melt | dissolution water 4 mentioned later become inadequate, and the coagulant effect of the oil component by a polymer coagulant | flocculant and a suspended substance is not acquired. Therefore, the flow rate of the oil-containing wastewater 2 continuously supplied to the reaction tank 9 is preferably in the range of 5 to 100 m ³ / hr.

凝集剤貯留槽３内の凝集剤溶解水４は、計量槽７から反応槽９へ供給される含油廃水２に凝集剤配管23を通って添加される。図１には、計量槽７と反応槽９の中間で、含油廃水２に凝集剤溶解水４を添加する例を示したが、凝集剤溶解水４を反応槽９に投入するように凝集剤配管23を配設しても良い。
このようにして得た含油廃水２と凝集剤溶解水４との混合水10を反応槽９内で撹拌する。図１には、モーターで撹拌翼を回転させる混合水撹拌装置11を示したが、混合水10中に空気を吹き込んで混合水10をバブリングさせて撹拌する撹拌装置（以下、曝気式撹拌装置という）を使用しても良い。混合水撹拌装置11および曝気式撹拌装置は、いずれも簡素な構成で常時稼働させることが可能であり、かつ間欠運転も容易であるから好ましい。 The flocculant-dissolved water 4 in the flocculant storage tank 3 is added through the flocculant pipe 23 to the oil-containing wastewater 2 supplied from the measuring tank 7 to the reaction tank 9. FIG. 1 shows an example in which the flocculant-dissolved water 4 is added to the oil-containing wastewater 2 between the measuring tank 7 and the reaction tank 9, but the flocculant-dissolved water 4 is added to the reaction tank 9. A pipe 23 may be provided.
The mixed water 10 of the oil-containing wastewater 2 and the flocculant-dissolved water 4 thus obtained is stirred in the reaction tank 9. FIG. 1 shows a mixed water stirring device 11 in which a stirring blade is rotated by a motor. However, an agitating device (hereinafter referred to as an aeration type stirring device) that stirs air by bubbling the mixed water 10 into the mixed water 10. ) May be used. Both of the mixed water agitator 11 and the aeration-type agitator are preferable because they can always be operated with a simple configuration and are easily operated intermittently.

反応槽９内で混合水10を撹拌することによって、油分や懸濁物質が高分子凝集剤の凝集効果によって固化し微細な粒子（いわゆるフロック）となり、さらに凝集して、フロックの凝集体（いわゆるスカム）を形成する。
そして、混合水10がスカム13とともに分離槽12へ供給され、分離槽12内で混合水10とスカム13が分離される。図１には、混合水10とスカム13を分離するためにスクリーンフィルター14を用いる例を示したが、本発明では混合水10とスカム13を分離するための機器は特に限定せず、従来から知られているものを使用する。 By stirring the mixed water 10 in the reaction vessel 9, the oil and suspended substances are solidified by the aggregation effect of the polymer flocculant to become fine particles (so-called flocs), and further aggregate to form floc aggregates (so-called so-called flocs). Scum).
Then, the mixed water 10 is supplied to the separation tank 12 together with the scum 13, and the mixed water 10 and the scum 13 are separated in the separation tank 12. FIG. 1 shows an example in which the screen filter 14 is used to separate the mixed water 10 and the scum 13. However, in the present invention, an apparatus for separating the mixed water 10 and the scum 13 is not particularly limited, and has been conventionally used. Use a known one.

分離槽12にて混合水10から分離されたスカム13は、その表面に混合水10が付着、あるいはその内部に混合水10が浸透しているので、スカム13を脱水槽16へ供給して脱水する。なお、図１に示すように、脱水槽16へ供給する前にスカム13をスカムホッパー15に貯留して、スカムホッパー15から間欠的に脱水槽16へ供給しても良い。
脱水槽16から排出されたスカム13は、スカム貯留槽17に貯留され、その後、産業廃棄物として処理される。スカム貯留槽17内のスカム13は、付着あるいは浸透した混合水10が除去されているので、産業廃棄物として問題なく処理できる。 The scum 13 separated from the mixed water 10 in the separation tank 12 has the mixed water 10 attached to the surface or the mixed water 10 has penetrated into the scum 13, so the scum 13 is supplied to the dewatering tank 16 and dehydrated. To do. As shown in FIG. 1, the scum 13 may be stored in the scum hopper 15 before being supplied to the dewatering tank 16 and may be intermittently supplied from the scum hopper 15 to the dewatering tank 16.
The scum 13 discharged from the dewatering tank 16 is stored in the scum storage tank 17, and then processed as industrial waste. The scum 13 in the scum storage tank 17 can be treated without any problem as industrial waste because the adhering or penetrating mixed water 10 is removed.

図１には、スカム13を脱水するために、ローラーでスカム13を挟むことによって、スカム13から混合水10を絞り出す例を示したが、本発明では脱水するための機器は特に限定せず、従来から知られているものを使用する。
脱水槽16にてスカム13から絞り出された混合水10は、未反応の少量の油分、懸濁物質、未反応の高分子凝集剤が残留しているので、第１循環配管18を介して廃水貯留槽１に供給される。脱水槽16から排出される混合水10を反応槽９へ供給することも可能ではあるが、本発明では第１循環配管18を脱水槽16から廃水貯留槽１に連結する。その理由は、処理状況により、混合水中の油分および高分子凝集剤の濃度が上昇した場合に、反応槽９に供給すると、反応槽９の容積が小さいことから、含油廃水２中の油分濃度が変動し、処理が不安定になる惧れがあるためである。廃水貯留槽１の容積は、反応槽９と比較して大きいので、変動量が少なく抑えられ、処理に及ぼす影響が小さくなる。 FIG. 1 shows an example in which the mixed water 10 is squeezed out from the scum 13 by sandwiching the scum 13 with a roller in order to dehydrate the scum 13, but in the present invention, the device for dehydration is not particularly limited, A conventionally known one is used.
The mixed water 10 squeezed from the scum 13 in the dewatering tank 16 contains a small amount of unreacted oil, suspended solids, and unreacted polymer flocculant. Supplied to the wastewater storage tank 1. Although it is possible to supply the mixed water 10 discharged from the dehydration tank 16 to the reaction tank 9, in the present invention, the first circulation pipe 18 is connected from the dehydration tank 16 to the waste water storage tank 1. The reason for this is that when the oil content in the mixed water and the concentration of the polymer flocculant are increased depending on the treatment status, if the reaction tank 9 is supplied, the volume of the reaction tank 9 is small. This is because it may fluctuate and processing may become unstable. Since the volume of the wastewater storage tank 1 is larger than that of the reaction tank 9, the amount of fluctuation is suppressed, and the influence on the processing is reduced.

一方で、分離槽12にてスカム13を分離した混合水10は、混合水貯留槽19に貯留される。この混合水貯留槽19内の混合水10には、少量の油分、懸濁物質、高分子凝集剤が残留しているので、第２循環配管20を介して反応槽９に供給される。混合水貯留槽19内の混合水10を廃水貯留槽１へ供給することも可能ではあるが、本発明では第２循環配管20を混合水貯留槽19から反応槽９に連結する。その理由は、廃水貯留槽１へ返送した場合に、処理される廃水量が増加するので、処理時間の延長を招くからである。それに伴い、薬品使用量も増加することになるので、好ましくない。 On the other hand, the mixed water 10 from which the scum 13 has been separated in the separation tank 12 is stored in the mixed water storage tank 19. Since a small amount of oil, suspended matter, and polymer flocculant remain in the mixed water 10 in the mixed water storage tank 19, the mixed water 10 is supplied to the reaction tank 9 via the second circulation pipe 20. Although it is possible to supply the mixed water 10 in the mixed water storage tank 19 to the waste water storage tank 1, in the present invention, the second circulation pipe 20 is connected from the mixed water storage tank 19 to the reaction tank 9. The reason for this is that when the wastewater is returned to the wastewater storage tank 1, the amount of wastewater to be processed increases, resulting in an increase in processing time. Accordingly, the amount of chemicals used is also increased, which is not preferable.

さらに、第２循環配管20の端部にスプレー21を取り付けて、混合水貯留槽19から供給される混合水10を反応槽９の上方から噴霧する。その理由は、反応槽９の水面上に反応したスカム13が徐々に滞留し、処理に不具合が生じるので、後段の分離槽12にスカム13を送り出す役目を持たせるためである。また、水面に噴霧することで、反応によって生成したスカム13が気泡を抱き、後段の分離槽９において水面上に浮き易くなり、分離が容易になるという効果もある。 Furthermore, the spray 21 attached to an end portion of the second circulation pipe 20, you sprayed mixed water 10 supplied from the mixing water storage tank 19 from above the reaction vessel 9. The reason is that the scum 13 that has reacted on the water surface of the reaction tank 9 gradually accumulates, causing a problem in the processing, and thus has a function of feeding the scum 13 to the separation tank 12 in the subsequent stage. Further, by spraying on the water surface, the scum 13 generated by the reaction holds bubbles, and it is easy to float on the water surface in the separation tank 9 in the subsequent stage, so that the separation is facilitated.

このようにして混合水10を循環させることによって、混合水10中に残留する高分子凝集剤が、その凝集作用を油分、懸濁物質に対して十分に発揮する。そのため、混合水貯留槽19内の混合水10は、残留する油分、懸濁物質、高分子凝集剤の濃度が極めて低く抑えることが可能となり、一般の廃水処理設備に供給しても問題なく処理できる。油分、懸濁物質が十分に除去されているかどうかについては、混合水貯留槽19から排出される処理水の濁度を、濁度測定装置25を用いて計測する。処理水の濁度が所定の数値以下となるように、凝集剤貯留槽３から供給される凝集剤溶解水４の供給量を自動で調整し、含油廃水２と凝集剤溶解水４の混合割合を調整する。 By circulating the mixed water 10 in this manner, the polymer flocculant remaining in the mixed water 10 sufficiently exhibits its aggregating action on oil and suspended substances. Therefore, the mixed water 10 in the mixed water storage tank 19 can keep the concentration of residual oil, suspended solids, and polymer flocculants extremely low, and can be processed without problems even if supplied to general wastewater treatment facilities. it can. Whether or not the oil and suspended substances are sufficiently removed is determined by using the turbidity measuring device 25 to measure the turbidity of the treated water discharged from the mixed water storage tank 19. The supply amount of the flocculant-dissolved water 4 supplied from the flocculant storage tank 3 is automatically adjusted so that the turbidity of the treated water is below a predetermined value, and the mixing ratio of the oil-containing waste water 2 and the flocculant-dissolved water 4 is adjusted. Adjust.

図２は、本発明を適用して含油廃水の油分除去を行なう手順の他の例を示すフロー図である。
図２に示す例では、廃水貯留槽１から計量槽７に含油廃水２を供給する廃水配管６にラインミキサー22を配設し、そのラインミキサー22に凝集剤貯留槽３から凝集剤溶解水４を供給する。そのラインミキサー22は、含油廃水２に凝集剤溶解水４を添加しながら流通させることによって撹拌し、混合水10中でスカム13が浮遊するスラリー状流体とするものである。したがって、ラインミキサー22の出側からスラリー配管（図示せず）を用いて分離槽12にスラリー状流体を運搬すれば、計量槽７や反応槽９を使用しない設備構成とすることが可能である。その場合は、設備構成の簡素化を図り、油分除去のコスト削減に寄与する。 FIG. 2 is a flowchart showing another example of a procedure for removing oil content of oil-containing wastewater by applying the present invention.
In the example shown in FIG. 2, a line mixer 22 is disposed in a wastewater pipe 6 for supplying oil-containing wastewater 2 from the wastewater storage tank 1 to the measuring tank 7, and the flocculant dissolved water 4 from the flocculant storage tank 3 is connected to the line mixer 22. Supply. The line mixer 22 is agitated by adding the flocculant-dissolved water 4 to the oil-containing wastewater 2 while being circulated, thereby forming a slurry fluid in which the scum 13 floats in the mixed water 10. Therefore, if the slurry-like fluid is transported from the outlet side of the line mixer 22 to the separation tank 12 using a slurry pipe (not shown), it is possible to have an equipment configuration that does not use the measuring tank 7 or the reaction tank 9. . In that case, the equipment configuration is simplified and the oil removal cost is reduced.

あるいは図２に示すように、ラインミキサー22に加えて、計量槽７と反応槽９を併用する場合は、図２中の凝集剤配管23を使用しない設備構成とすることも可能である。凝集剤配管23を使用しなくても、ラインミキサー22の撹拌効果によって、図１に示す設備構成に比べて油分除去の効率を高めることができる。また、図２に示すように、凝集剤配管23を併用すれば、油分除去の効率を一層高めることができる。 Alternatively, as shown in FIG. 2, in addition to the line mixer 22, when the measuring tank 7 and the reaction tank 9 are used together, it is possible to adopt an equipment configuration that does not use the flocculant piping 23 in FIG. Even if the flocculant pipe 23 is not used, the efficiency of oil removal can be increased by the stirring effect of the line mixer 22 as compared with the equipment configuration shown in FIG. Further, as shown in FIG. 2, if the coagulant pipe 23 is used in combination, the oil removal efficiency can be further increased.

図３は、図１に示すフロー図の反応槽９の出側に分離脱水槽24を配設する設備構成の例である。分離脱水槽24は、混合水10とスカム13の分離、およびそのスカム13の脱水を行なうものである。したがって、図１中の分離槽12、スカムホッパー15、脱水槽16の機能を、１台の分離脱水槽24で担うことができ、設備構成の簡素化を図り、油分除去のコスト削減に寄与する。 FIG. 3 is an example of an equipment configuration in which a separation / dehydration tank 24 is provided on the outlet side of the reaction tank 9 in the flow chart shown in FIG. The separation / dehydration tank 24 separates the mixed water 10 and the scum 13 and dehydrates the scum 13. Therefore, the functions of the separation tank 12, the scum hopper 15, and the dehydration tank 16 in FIG. 1 can be performed by one separation / dehydration tank 24, which simplifies the equipment configuration and contributes to the cost reduction of oil removal. .

また分離脱水槽24は、図２に示すようなラインミキサー22を配設する設備構成においても、支障なく使用できる。
以上に説明した通り、本発明によれば、高分子凝集剤を過不足なく使用し、しかも簡素でかつコンパクトな設備を用いて含油廃水の油分除去を十分に行なうことができる。 Further, the separation / dehydration tank 24 can be used without any trouble even in the equipment configuration in which the line mixer 22 is disposed as shown in FIG.
As described above, according to the present invention, it is possible to sufficiently remove the oil content of the oil-containing wastewater by using the polymer flocculant without excess or deficiency and using a simple and compact facility.

本発明を適用し、図１に示す手順で含油廃水の油分除去を行なった。その手順を説明する。
食品工場やクリーニング工場から排出された含油廃水２を選別せずに廃水貯留槽１に貯留した。一方で、凝集剤貯留槽３に凝集剤溶解水４を貯留した。凝集剤溶解水４は、市販の高分子凝集剤（１種類）を工業用水に溶解した水溶液とし、凝集剤溶解水４中の高分子凝集剤の濃度は0.3質量％、凝集剤溶解水４の粘度は500mPa・sとした。なお凝集剤貯留槽３内の凝集剤溶解水４は、モーターで撹拌翼を回転させる凝集剤撹拌機５で撹拌した。 The present invention was applied, and the oil content of the oil-containing wastewater was removed by the procedure shown in FIG. The procedure will be described.
Oil-containing wastewater 2 discharged from a food factory or a cleaning factory was stored in a wastewater storage tank 1 without sorting. On the other hand, the flocculant-dissolved water 4 was stored in the flocculant storage tank 3. The flocculant-dissolving water 4 is an aqueous solution in which a commercially available polymer flocculant (one type) is dissolved in industrial water. The concentration of the polymer flocculant in the flocculant-dissolving water 4 is 0.3% by mass. The viscosity was 500 mPa · s. The flocculant-dissolved water 4 in the flocculant storage tank 3 was stirred with a flocculant stirrer 5 that rotates a stirring blade with a motor.

そして、廃水貯留槽１内の含油廃水２を廃水配管６から計量槽７を経て、流量10ｍ³／hrで反応槽９へ連続的に供給した。その含油廃水２に、凝集剤貯留槽３内の凝集剤溶解水４を凝集剤配管23から添加した。このようにして得た含油廃水２と凝集剤溶解水４との混合水10を、モーターで撹拌翼を回転させる混合水撹拌装置11で撹拌した。撹拌することによって、油分や懸濁物質をフロックとし、さらに凝集させてスカムを形成した。 Then, the oil-containing wastewater 2 in the wastewater storage tank 1 was continuously supplied from the wastewater pipe 6 through the measuring tank 7 to the reaction tank 9 at a flow rate of 10 m ³ / hr. The flocculant-dissolved water 4 in the flocculant storage tank 3 was added to the oil-containing waste water 2 from the flocculant pipe 23. The mixed water 10 of the oil-containing wastewater 2 and the flocculant-dissolved water 4 thus obtained was stirred by a mixed water stirring device 11 in which a stirring blade was rotated by a motor. By stirring, the oil and suspended substances were turned into flocs and further agglomerated to form scum.

次いで、混合水10をスカム13とともに分離槽12へ送給し、混合水10とスカム13を分離した。
分離槽12にて混合水10から分離されたスカム13は、スカム13を脱水槽16で脱水した後、産業廃棄物として問題なく処理できた。
脱水槽16にてスカム13から絞り出された混合水10は、第１循環配管18を介して廃水貯留槽１に供給し、再び油分除去の処理に供した。 Next, the mixed water 10 was fed to the separation tank 12 together with the scum 13 to separate the mixed water 10 and the scum 13.
The scum 13 separated from the mixed water 10 in the separation tank 12 could be treated without any problem as industrial waste after the scum 13 was dehydrated in the dehydration tank 16.
The mixed water 10 squeezed from the scum 13 in the dewatering tank 16 was supplied to the wastewater storage tank 1 via the first circulation pipe 18 and again subjected to the oil removal process.

また、分離槽12にてスカム13を分離した混合水10は、混合水貯留槽19に貯留し、さらに第２循環配管20を介して反応槽９に供給し、再び油分除去の処理に供した。
こうして混合水10を循環させることによって、高分子凝集剤を過不足なく使用し、かつ含油廃水の油分除去を十分に行なうことができた。その結果、分離槽12にてスカム13を分離した混合水10は、一般の廃水処理設備で問題なく処理できた。 Further, the mixed water 10 from which the scum 13 has been separated in the separation tank 12 is stored in the mixed water storage tank 19 and further supplied to the reaction tank 9 via the second circulation pipe 20 and again subjected to the oil removal process. .
By circulating the mixed water 10 in this way, the polymer flocculant was used without excess and deficiency, and the oil content of the oil-containing wastewater could be sufficiently removed. As a result, the mixed water 10 from which the scum 13 was separated in the separation tank 12 could be treated without any problem in a general wastewater treatment facility.

以上のように第１循環配管18、第２循環配管20により、混合水10を循環した場合と、循環しない場合における処理性能は、表１および表２に示す通りであった。 As described above, the treatment performance when the mixed water 10 was circulated by the first circulation pipe 18 and the second circulation pipe 20 and when it was not circulated was as shown in Tables 1 and 2.

次に、クリーニング工場から排出された含油廃水２を選別せずに廃水貯留槽１に貯留し、凝集剤溶解水４中の高分子凝集剤の濃度および粘度を変化させて、処理を行なった。
含油廃水の流量は20ｍ³／hrで反応槽９へ連続的に供給した。その含油廃水２に、凝集剤貯留槽３内の凝集剤溶解水４を凝集剤配管23から添加した。
処理された混合水10については、第１循環配管18および第２循環配管20を介してそれぞれ循環させ、再び油分除去の処理に供した。 Next, the oil-containing wastewater 2 discharged from the cleaning factory was stored in the wastewater storage tank 1 without being selected, and the treatment was performed by changing the concentration and viscosity of the polymer flocculant in the flocculant-dissolved water 4.
The oil-containing wastewater flow rate was continuously supplied to the reaction tank 9 at 20 m ³ / hr. The flocculant-dissolved water 4 in the flocculant storage tank 3 was added to the oil-containing waste water 2 from the flocculant pipe 23.
The treated mixed water 10 was circulated through the first circulation pipe 18 and the second circulation pipe 20, respectively, and again subjected to oil removal treatment.

以上のような処理を行ない、高分子凝集剤の濃度および粘度を変化させた場合の処理性能は、表３に示す通りであった。 Table 3 shows the treatment performance when the treatment as described above was performed and the concentration and viscosity of the polymer flocculant were changed.

以上の油分除去を発明例とする。
従来の油分除去は、反応槽９におけるpHを調整しながら行なっていた。そして、計量槽７による流量調整および第１循環配管18や第２循環配管20による混合水10の循環を行なっておらず、高分子凝集剤の過不足が生じることから、油分除去の効率低下を招く原因になっていた。これを従来例とする。 The above oil removal is an invention example.
Conventional oil removal was performed while adjusting the pH in the reaction tank 9. The flow rate adjustment by the measuring tank 7 and the mixing water 10 by the first circulation pipe 18 and the second circulation pipe 20 are not circulated, and the excess of the polymer flocculant is generated. It was a cause. This is a conventional example.

既に述べた通り、発明例は、１種類の高分子凝集剤で含油廃水の油分除去を十分に行なうことができた。
これに対して従来例は、１種類の高分子凝集剤では含油廃水の油分除去の効率が低い、あるいは除去できないので、複数種類の薬剤（たとえば無機凝集剤、pH調整剤等）に加えて、高分子凝集剤を使用せざるを得なかった。油分除去の効率を高めるためには、これら一連の設備を設置する必要があり、それぞれの操作に応じて反応槽や沈殿槽等を設けなければならないので、設置スペースが過大となるという問題が生じる。 As described above, the inventive examples were able to sufficiently remove the oil content of the oil-containing wastewater with one kind of polymer flocculant.
On the other hand, in the conventional example, the efficiency of oil removal of oil-containing wastewater is low or cannot be removed with one type of polymer flocculant. The polymer flocculant had to be used. In order to increase the efficiency of oil removal, it is necessary to install a series of these equipments, and it is necessary to provide a reaction tank, a sedimentation tank, etc. according to each operation, which causes a problem that the installation space becomes excessive. .

したがって発明例は、従来例に比べて、設置スペースの縮小、処理コストの削減を図るとともに、設備管理の負荷軽減、高分子凝集剤の在庫管理の負荷軽減を図ることができる。 Therefore, compared to the conventional example, the invention example can reduce the installation space, reduce the processing cost, reduce the load of facility management, and reduce the load of inventory management of the polymer flocculant.

１廃水貯留槽
２含油廃水
３凝集剤貯留槽
４凝集剤溶解水
５凝集剤撹拌機
６廃水配管
７計量槽
８堰
９反応槽
10 混合水
11 混合水撹拌装置
12 分離槽
13 スカム
14 スクリーンフィルター
15 スカムホッパー
16 脱水槽
17 スカム貯留槽
18 第１循環配管
19 混合水貯留槽
20 第２循環配管
21 スプレー
22 ラインミキサー
23 凝集剤配管
24 分離脱水槽
25 濁度測定装置 DESCRIPTION OF SYMBOLS 1 Waste water storage tank 2 Oil impregnation waste water 3 Coagulant storage tank 4 Coagulant dissolution water 5 Coagulant stirrer 6 Waste water piping 7 Measuring tank 8 Weir 9 Reaction tank
10 Mixed water
11 Mixed water agitator
12 Separation tank
13 Scum
14 Screen filter
15 Scum Hopper
16 Dehydration tank
17 Scum storage tank
18 First circulation piping
19 Mixed water storage tank
20 Second circulation piping
21 spray
22 Line mixer
23 Flocculant piping
24 Separation dewatering tank
25 Turbidity measuring device

Claims

A wastewater storage tank for storing oil-containing wastewater containing oil and suspended substances, a flocculant storage tank for storing a flocculant-dissolved water obtained by dissolving a polymer flocculant in water, and the oil-containing oil supplied from the wastewater storage tank A measuring tank for adjusting the flow rate of waste water, and the oil content by stirring the mixed water obtained by adding the flocculant-dissolved water supplied from the flocculant storage tank to the oil-containing waste water supplied at a predetermined flow rate from the measuring tank. And a reaction tank that forms a scum that is a fine floc aggregate formed by solidification of the suspended solids, a separation tank that separates the scum in the mixed water supplied from the reaction tank, and a separation tank that is supplied from the separation tank. A dehydration tank for collecting the mixed water adhering to or penetrating the scum, a first circulation pipe for transporting the mixed water from the dehydration tank to the waste water storage tank, and storing the scum discharged from the dehydration tank. To And arm reservoir, wherein the mixed water storage tank for storing the mixed water discharged from the separation tank, the mixed water from the top of the reactor from the mixed water reservoir by transporting the mixed water into the reaction tank a second circulation pipe to spray, oil removal device of oil-containing waste water, comprising a.

The flocculant storage tank maintains the concentration of the polymer flocculant in the flocculant-dissolved water at 0.2% by mass or higher and the viscosity of the flocculant-dissolved water at 300 mPa · s or higher. Oil removal device for oil-containing wastewater.

^3. The oil content removal apparatus for oil-containing wastewater according to claim 1, wherein the metering tank maintains a flow rate of the oil-containing wastewater supplied to the reaction tank at 5 to 100 m ³ / hr.

The oil content removal device according to any one of claims 1 to 3, wherein the reaction tank has an aeration device or a stirring device for stirring the mixed water.

A line mixer is disposed in a waste water pipe for supplying the oil-containing waste water from the waste water storage tank to the metering tank, and the flocculant dissolved water is supplied from the flocculant storage tank to the line mixer. Item 5. The oil content removal apparatus according to any one of Items 1 to 4 .

The line mixer circulates while adding the flocculant-dissolved water to the oil-containing wastewater to form a slurry-like fluid in which the scum floats in the mixed water, and transports the slurry-like fluid from the line mixer to the separation tank. The oil content removal apparatus of oil-containing wastewater of Claim 5 which has a slurry piping to perform.

A turbidity measuring device is installed at the outflow part of the mixed water storage tank, the turbidity of the treated water separated from the mixed water is measured, and the measured value of the turbidity of the treated water is not more than a predetermined value. The oil content removal apparatus according to any one of claims 1 to 5 , wherein the mixing ratio of the polymer flocculant is automatically adjusted.

The oil-containing wastewater containing oil and suspended substances is stored in the wastewater storage tank, and the flocculant-dissolved water obtained by dissolving the polymer flocculant in water is stored in the flocculant storage tank, and is supplied from the wastewater storage tank Supplying the flocculant-dissolved water from the flocculant storage tank to the reaction tank while adjusting the flow rate of the oil-containing wastewater in the measuring tank, and supplying the flocculant dissolved water to the oil-containing wastewater in the reaction tank By stirring the mixed water to which dissolved water has been added, a scum that is a fine floc aggregate formed by solidifying the oil and the suspended solids is formed, and the scum in the mixed water supplied from the reaction tank is separated. The mixed water which is separated in a tank and then adheres to or penetrates the scum supplied from the separation tank is collected in a dehydration tank, and the mixed water is transferred from the dehydration tank to the waste water storage tank using a first circulation pipe. While carrying The scum discharged from the dehydration tank is stored in a scum storage tank, the mixed water discharged from the separation tank is stored in a mixed water storage tank, and the mixed water is transferred from the mixed water storage tank to the reaction tank. A method for removing oil content of oil-containing wastewater, which is transported using a second circulation pipe and sprayed with the mixed water from above the reaction tank .

At the coagulant reservoir, to claim 8, characterized in that to keep the viscosity of 0.2 mass% or more and the flocculant dissolved water concentration of polymer flocculant in the flocculant dissolved in water to more than 300 mPa · s The oil removal method of the oil-containing wastewater as described.

The oil removal method for oil-containing wastewater according to claim 8 or 9 , wherein a flow rate of the oil-containing wastewater supplied to the reaction tank is maintained at 5 to 100 m ³ / hr in the measuring tank.

The method for removing oil content of oil-containing wastewater according to any one of claims 8 to 10 , wherein the mixed water is stirred in the reaction tank using an aeration device or a stirring device.

A line mixer which is arranged in the waste water pipe for supplying the oil-containing wastewater into the measuring tank from the waste water storage tank, according to claim 8-1 1, wherein the supplying the flocculant dissolved water from the coagulant reservoir The oil content removal method of oil-containing wastewater as described in any one of these.

In the line mixer, the flocculant-dissolved water is circulated while being added to the oil-containing wastewater to form a slurry-like fluid in which the scum floats in the mixed water, and the slurry-like fluid is transferred from the line mixer to the separation tank. oil removal method of the oil-containing wastewater according to claim 1 2, characterized in that transporting using a slurry pipe.

Using the turbidity measuring device installed at the outflow part of the mixed water storage tank, the turbidity of the treated water separated from the mixed water is measured, and the measured value of the turbidity of the treated water is not more than a predetermined value. The method for removing oil content of oil-containing wastewater according to any one of claims 8 to 12 , wherein the mixing ratio of the polymer flocculant is automatically adjusted so as to be.