JP5044746B2

JP5044746B2 - Oil-water separation method

Info

Publication number: JP5044746B2
Application number: JP2001321191A
Authority: JP
Inventors: 倫波多野
Original assignee: 日本ソリッド株式会社
Priority date: 2001-09-13
Filing date: 2001-09-13
Publication date: 2012-10-10
Anticipated expiration: 2021-09-13
Also published as: JP2003080242A

Description

【０００１】
【発明の属する技術分野】
本発明は、流出油等の油類を含有する処理水の油水分離方法に関する。
【０００２】
【従来の技術】
従来、タンカーの座礁等により油が流出した場合オイルフェンスで囲繞して油の拡散を防止したうえで、油吸着材を投入して水表面に浮遊する油を自然吸着させていた。又、油水分離処理においても同様であった。
しかしながら、このような方法で油を自然吸着させた場合、吸着材は油以外に多量の水分を含浸するために吸着材を引き上げたときに水垂れが生じ、それと共に一旦吸着した油も同時に垂れ落ちてしまう欠点があった。
【０００３】
また他の回収方法として油回収船による回収も行われているが現場での油水分離が行われない為、実質、高濃度油の回収効率が低い等の欠点があった。
【０００４】
【発明が解決しようとする課題】
そこで本発明者は簡単な処理操作によって油回収率の高い方法について種々研究を重ねた結果本発明を完成するに至った。
【０００５】
【課題を解決するための手段】
すなわち、本発明は、油を含有する処理水に油吸着材の存在下において、すり鉢形の凹部を有する渦巻流を生起させて処理することを特徴とする、油水の分離方法である。
【０００６】
【発明の実施の形態】
次に本発明方法を具体例を揚げて説明するが、本発明方法は以下の具体例のみに限定されるものではない。
【０００７】
図１は油水処理槽の断面図である。
まず、油水処理槽は、基本的には油水処理タンク１に油を含有する処理水（以下油水という）を導入する管２を設け、油水処理タンク１の底部に撹拌装置３が設けられ、かつ排水弁を有する排水口４から構成されている。
【０００８】
油水を管２から油水処理タンク１内に注入し、所定水量に達したときに注入を停止する。
次に油水処理タンク１の底部に設けられた例えば撹拌羽根等の攪拌装置３により油水処理タンク１内の油水に回転流を与えることによりすり鉢形の凹部を有する渦巻流を生起させる。この渦巻流に油吸着材を投入すると、油水中の油分と油吸着材が比重差により渦巻流の中心部に集められ、両者が強制的に接触することにより油分が油吸着材に吸収され捕捉される。油吸着材は渦巻流の中心部で油分を捕捉しながら渦巻流によって下方に運ばれ、やがて油水処理タンク１の底部近傍に達したときに中心流から開放された油吸着材は、壁面等に接触しながら上昇流に乗って浮上する。この際油吸着材は油水処理タンク１内を回流しながら上昇し、その際に油水処理タンク１の内壁面を擦るので油水処理タンク１の内壁面に付着している油分を捕捉し油分の回収率が高められる。このようにして浮遊する油類を油吸着材で捕捉したら撹拌を停止して油吸着材を除去した後排出口４より処理した水を抜き取る。
【０００９】
油吸着材の投入時期は前記のように渦巻流を生起させた後投入しても良いが、他の方法として渦巻流を生起させる前に投入することもできる。また一旦油類を吸着した油吸着材はプレス等により脱油し再利用することができる。
【００１０】
図１に示すように油水処理タンク１の底部はテーパーを設けて底面積を小さくすることによって渦巻流を効率的に生起させることができる。もちろん同一直径の円柱状を呈した油水処理タンク１によっても渦巻流を生起させることができる。
【００１１】
撹拌装置３についても図１においては撹拌羽根を用いる場合を示したが、その他の手段として例えば図２に示すように油水処理タンク１の底部に、該油水処理タンク１の接線方向に複数の噴出口５を設け、ここから油水あるいは別の系統から水や気液体を供給して高圧で噴射することによっても渦巻流を生起させることができる。
【００１２】
また油水処理タンク１の上液面近傍に渦巻流の生起を助ける撹拌補助装置を付設することもできる（図示せず）。かかる撹拌補助装置としては図２に示したような高圧噴射水等種々の手段が採用できる。
【００１３】
また撹拌補助装置の他の態様として油水処理タンク１の内壁に沿って棒状体を回動させて、油水に回転流を生起させることによりすり鉢形の凹部を有する渦巻流の生起を補助することができる。さらに、撹拌補助装置は撹拌手段を変えることによって状況に応じて撹拌装置として機能させることもできる。
【００１４】
また前記油水処理タンク１には油分を吸着した後の浮上した油吸着材を回収するためのスクレパーを設けることもできる。
【００１５】
本発明方法に用いられる他の油水処理装置としては図３に示すように円柱状管６の上部にロート型の油吸着材供給ホッパー７を設け、かつ円柱状管６の側壁に該円柱状管６の接線方向に向けて油水を噴出するパイプ８を設ける。このパイプ８は１本であっても複数でも差し支えない。
【００１６】
図３に示すような油水処理装置を用いて油分と水に分離する方法について説明する。
まずパイプ８から油水を高圧で噴射すると、油水は円柱状管８の内壁面に沿って回動し、渦巻流が生起する。この渦巻流中に油吸着材供給ホッパー７より油吸着材を投入すると、該油吸着材は渦巻流中に混入され、渦巻流の中心部に集められた油分と接触して油分を油吸着材中に捕捉して下方に流下する。これを例えば静置タンク等に入れて油分を捕捉した油吸着材を分離することにより、処理水より油分を除去することができる。このような方法を利用すれば油水を連続的に処理することができる。
【００１７】
さらに本発明方法は油分が流出した水域の水面下に直接大型吸入撹拌装置を入れて撹拌することにより、すり鉢形の凹部を有する渦巻流を生起させ、そこに油吸着材を投入して処理することもできる。この場合好ましくはシート膜等により囲繞しその内に大型撹拌装置を入れて処理すると一層効率的である。その際に、使用する油吸着材に発光色を着けると夜間でも油吸着材が光って見え作業ができる。発光色剤は油吸着材に入れても、塗布しても良い。又、超音波振動を与えて早期の油水分離を行なうこともできる。
【００１８】
本発明方法のようにして処理した後の油吸着材は実質的に油分のみを吸収しているので回収の為に水から引き上げても油垂れがなくしっかりと油吸着材に捕捉されている。
一方水面上に浮遊した状態の油類を油吸着材で自然吸着し、長時間放置すると油分より水分を多く吸収するために回収時に水面から引き上げたときに水垂れと共に油垂れも生じ油分の回収率が低下する等の問題があった。油水は種類、温度、濃度、状態等によって油水分離時間が異なり油吸着にも長時間を要する欠点があった。かかる従来技術と比較して本発明方法にあっては強制混合撹拌する為、油分との接触が油水分離以前にも可能となり油水分離する時間を必要としない。したがって吸着時間が特段に速く、処理時間の短縮が計れると共に油回収率も向上する。
【００１９】
本発明方法に用いられる油吸着材としては油の吸着機能を有するものであればいずれも使用でき、また形状も特に限定されるものではないが、好ましくは油吸着材の表面積が１ｃｍ^２〜２，５００ｃｍ^２のものを有し、また形状もサイコロ状、短冊状を呈したものが好ましい。
【００２０】
また本発明方法に用いられる油吸着材の使用量は油水中の油分量によっても異なるが一般的には例えば油処理槽で処理する場合であれば油吸着材の油含有色が呈して液面を覆う程度の量投入することが好ましい。
【００２１】
本発明方法によって処理できる油水としてはタンカー船のバラスト廃水、ビルジ廃水、油回収船の使用後の洗浄廃水、起重機作業船の作動油流出油水、海上流出油、ガソリンスタンドの流出油、食品工場及び厨房の油水廃水、機械工場の油水廃水、下水処理場の油濁廃水等の前段処理、後段処理、完結処理が挙げられる。
【００２２】
油水中の油量も水面上に薄膜上に浮遊する低濃度のものから高濃度のもの迄適宜処理することができ、かつ時間が経過してボール状等の塊状になったものでもエマルジョンブレーカー等を用いて壊すことによって好適に処理することができる。
【００２３】
更に、油の種類、油流出場所の海象条件により、油の状態は不特定である。粘性が高い油水においては超音波振動によって油水分離を行なわせたり、油水処理タンク内の油水を蒸気等で加温することにより、油の粘性を下げ、油吸着効果を高める事が好ましい。油水を加温する方法として、油吸着材に「使い捨てカイロ」や「使い捨てお酒のお燗」等の空気や水に触れると発熱する機能を持たせる方法や、油水処理タンク内の油水に加熱水蒸気を送り油水の温度を上げる方法や、油水処理タンク内壁面や撹拌装置を加熱する方法、超音波振動することによって、油水処理タンク内壁面や撹拌装置に付着する油を油吸着材に吸着し易くすることができる。
【００２４】
次に本発明をさらに具体的に説明するために実施例を挙げて説明するが本発明は以下の実施例にのみ限定されるものではない。
【実施例】
１ｌのビーカーに水８００ｍｌを入れ、これに重油３ｍｌを加えた後マグネチックスターラーを用いて中心部にすり鉢形の凹部を有する渦巻流を生起させる。ここに、一辺１０ｍｍのサイコロ状の油吸着材を０．３ｇ入れて５分間撹拌を続けた。
油水中の油分と油吸着材は渦巻流の中心部で激しく接触して油吸着材に吸着（吸収）された。渦巻流によって下方に流下した油吸着材はビーカーの底部で外周部に向けて流れ旋回流に同調して回りながら浮上し、さらに渦巻流に巻き込まれて前記と同様な運動を繰り返す。
その際ビーカーの内壁面を擦るために内壁面に付着した重油もきれいに取り除かれた。
撹拌開始から５分経過後水中から重油が取り除かれたことを確認した後マグネチックスターラーを停止させ、重油を捕捉した油吸着材をピンセットで軽くつまんでバットの上に移した。１時間経過後もバット上に移した油吸着材から重油の漏れはまったくなかった。
【００２５】
【比較例】
実施例と同様にして同一のビーカーを用い水および重油も同一量用いた。水面に浮いた重油に実施例と同一の油吸着材を同量加えた。油吸着材を入れて５分経過後油吸着材をピンセットで軽くつまんで引き上げバット上に移した。
この引き上げの際水と重油の一部が垂れ落ちた。バットに移した後２分経過後バット中に重油が漏れ出した。またビーカー中の重油も完全には吸着されず一部残在していた。
【００２６】
【発明の効果】
本発明方法によれば、低濃度から高濃度に至る油分を短時間で回収することができると共に油分を捕捉した油吸着材からの油垂れもなく、さらに脱油した油吸着材はさらに再利用することができる。
【図面の簡単な説明】
【図１】本発明方法に使用する油水処理槽の断面図
【図２】図１の油処理槽底部の断面図
【図３】本発明方法に使用する油水処理槽の断面図
【符号の説明】
１・・・油水処理タンク
２・・・管
３・・・撹拌装置
４・・・排出口[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil-water separation method for treated water containing oils such as spilled oil.
[0002]
[Prior art]
Conventionally, when oil is spilled by a tanker's ground or the like, it is surrounded by an oil fence to prevent the oil from diffusing, and then an oil adsorbent is introduced to naturally adsorb the oil floating on the water surface. The same was true for the oil / water separation treatment.
However, when the oil is naturally adsorbed by such a method, the adsorbent is dripped when the adsorbent is pulled up to impregnate a large amount of moisture in addition to the oil, and the oil once adsorbed at the same time. There was a fault that would fall.
[0003]
In addition, as another recovery method, recovery by an oil recovery ship is also performed, but since there is no oil-water separation on site, there are disadvantages such as low recovery efficiency of high-concentration oil.
[0004]
[Problems to be solved by the invention]
Therefore, the present inventor conducted various studies on a method having a high oil recovery rate by a simple processing operation, and as a result, the present invention has been completed.
[0005]
[Means for Solving the Problems]
That is, the present invention is an oil-water separation method characterized in that treatment is performed by causing a swirl flow having a mortar-shaped recess to occur in treated water containing oil in the presence of an oil adsorbent.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, the method of the present invention will be described with specific examples. However, the method of the present invention is not limited to the following specific examples.
[0007]
FIG. 1 is a cross-sectional view of an oil / water treatment tank.
First, the oil / water treatment tank is basically provided with a pipe 2 for introducing treated water containing oil (hereinafter referred to as oil / water) into the oil / water treatment tank 1, a stirring device 3 is provided at the bottom of the oil / water treatment tank 1, and It is comprised from the drain port 4 which has a drain valve.
[0008]
Oil water is injected into the oil water treatment tank 1 from the pipe 2, and the injection is stopped when a predetermined amount of water is reached.
Next, a swirling flow having a mortar-shaped concave portion is generated by applying a rotating flow to the oil water in the oil / water treatment tank 1 by a stirring device 3 such as a stirring blade provided at the bottom of the oil / water treatment tank 1. When an oil adsorbent is introduced into this swirl, the oil in the oil and the oil adsorbent are collected in the center of the swirl due to the difference in specific gravity, and the oil is absorbed and captured by the oil adsorbent when they are forced to contact each other. Is done. The oil adsorbent is transported downward by the swirl flow while capturing oil at the center of the swirl flow, and the oil adsorbent released from the center flow when it reaches the vicinity of the bottom of the oil-water treatment tank 1 eventually reaches the wall surface or the like Ascend while riding up the ascending current. At this time, the oil adsorbent rises while circulating in the oil / water treatment tank 1, and rubs the inner wall surface of the oil / water treatment tank 1 at that time, so that the oil adhering to the inner wall surface of the oil / water treatment tank 1 is captured and the oil content is recovered. The rate is increased. When the floating oil is captured by the oil adsorbing material in this way, stirring is stopped to remove the oil adsorbing material, and then the treated water is extracted from the discharge port 4.
[0009]
The oil adsorbent may be charged after the swirl flow is generated as described above, but may be charged before the swirl flow is generated as another method. The oil adsorbent once adsorbed oil can be deoiled and reused by a press or the like.
[0010]
As shown in FIG. 1, the bottom of the oil / water treatment tank 1 is tapered so that a spiral area can be efficiently generated by reducing the bottom area. Of course, a vortex flow can also be generated by the oil / water treatment tank 1 having a cylindrical shape with the same diameter.
[0011]
As for the stirring device 3, the case where the stirring blades are used is shown in FIG. 1. However, as other means, for example, as shown in FIG. A spiral flow can also be generated by providing the outlet 5 and supplying water or gas / liquid from the oil water or another system and injecting it at a high pressure.
[0012]
Also, an agitation assisting device that assists the generation of a spiral flow can be provided near the upper liquid surface of the oil / water treatment tank 1 (not shown). As such a stirring assist device, various means such as high-pressure jet water as shown in FIG. 2 can be adopted.
[0013]
As another aspect of the stirring assist device, the rod-shaped body is rotated along the inner wall of the oil / water treatment tank 1 to generate a rotating flow in the oil / water, thereby assisting the generation of a spiral flow having a mortar-shaped recess. it can. Furthermore, the stirring assist device can function as a stirring device depending on the situation by changing the stirring means.
[0014]
Further, the oil / water treatment tank 1 may be provided with a scraper for collecting the oil adsorbing material that has floated after adsorbing oil.
[0015]
As another oil-water treatment apparatus used in the method of the present invention, as shown in FIG. 3, a funnel-type oil adsorbent supply hopper 7 is provided at the top of the cylindrical tube 6, and the cylindrical tube is provided on the side wall of the cylindrical tube 6. A pipe 8 for jetting oil and water in the tangential direction of 6 is provided. The pipe 8 may be one or plural.
[0016]
A method for separating oil and water using an oil-water treatment apparatus as shown in FIG. 3 will be described.
First, when oil water is jetted from the pipe 8 at a high pressure, the oil water rotates along the inner wall surface of the cylindrical tube 8 to generate a spiral flow. When an oil adsorbent is introduced into the swirl flow from the oil adsorbent supply hopper 7, the oil adsorbent is mixed in the swirl flow and comes into contact with the oil collected at the center of the swirl to remove the oil from the oil adsorbent. Capture inside and flow down. For example, the oil content can be removed from the treated water by separating the oil adsorbent that has captured the oil content by placing it in a stationary tank or the like. If such a method is utilized, oil water can be processed continuously.
[0017]
Furthermore, in the method of the present invention, a large-sized suction stirrer is placed directly under the surface of the water area where the oil has flowed out to stir, thereby generating a spiral flow having a mortar-shaped recess, and an oil adsorbent is introduced into the swirl. You can also. In this case, it is more efficient to surround the sheet membrane with a sheet membrane or the like and put a large stirring device in it. At that time, if the oil adsorbent to be used is colored, the oil adsorbent will shine even at night. The luminescent colorant may be put in an oil adsorbing material or applied. In addition, it is possible to perform early oil-water separation by applying ultrasonic vibration.
[0018]
Since the oil adsorbent after being treated as in the method of the present invention substantially absorbs only the oil component, even if it is pulled up from the water for recovery, there is no oil dripping and it is firmly captured by the oil adsorbent.
On the other hand, oils floating on the surface of the water are naturally adsorbed with an oil adsorbent, and if left for a long time, it absorbs more water than the oil, so that when it is pulled up from the surface during recovery, oil dripping occurs as well as dripping. There was a problem that the rate decreased. Oil water has a drawback that the oil water separation time varies depending on the type, temperature, concentration, state, etc., and that oil adsorption takes a long time. Compared with such a conventional technique, in the method of the present invention, since forced mixing and stirring is performed, contact with the oil component is possible even before oil-water separation, and time for oil-water separation is not required. Therefore, the adsorption time is particularly fast, the processing time can be shortened and the oil recovery rate is improved.
[0019]
Any oil adsorbent used in the method of the present invention can be used as long as it has an oil adsorbing function, and the shape is not particularly limited, but the surface area of the oil adsorbent is preferably 1 cm ² to 2. , 500 cm ² , and a dice or strip shape is preferable.
[0020]
In addition, the amount of the oil adsorbent used in the method of the present invention varies depending on the amount of oil in the oil water, but generally the oil-containing color of the oil adsorbent exhibits the liquid level when treated in an oil treatment tank, for example. It is preferable to add an amount so as to cover.
[0021]
Oil water that can be treated by the method of the present invention includes tanker ballast waste water, bilge waste water, washing waste water after use of an oil recovery ship, hydraulic oil spilled oil from a hoist working ship, marine spilled oil, gas station spilled oil, food factory and Examples include pre-treatment, post-treatment, and completion treatment of oil and water wastewater from kitchens, oil and water wastewater from machine shops, and oily wastewater from sewage treatment plants.
[0022]
The amount of oil in the oil water can also be appropriately processed from low to high concentration floating on the water surface, and even if it becomes a lump like balls over time, an emulsion breaker etc. It can process suitably by breaking using.
[0023]
Furthermore, the state of the oil is unspecified depending on the type of oil and the sea conditions of the oil spill location. In oily water with high viscosity, it is preferable to reduce oil viscosity and enhance oil adsorption effect by separating oily water by ultrasonic vibration or heating the oily water in the oily water treatment tank with steam or the like. As a method of warming oil and water, the oil adsorbent has a function to generate heat when it is exposed to air or water, such as “disposable body warmers” or “disposable liquor bowls”, or it heats the oil water in the oil / water treatment tank. By adsorbing oil adhering to the oil / water treatment tank inner wall surface and the stirring device by the method of heating the temperature of the oil water by sending water vapor, heating the oil / water treatment tank inner wall surface and the stirring device, and ultrasonic vibration. Can be made easier.
[0024]
Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
【Example】
Into a 1 l beaker, 800 ml of water is added, and 3 ml of heavy oil is added thereto, and then a spiral flow having a mortar-shaped recess is formed in the center using a magnetic stirrer. Here, 0.3 g of a dice-shaped oil adsorbent having a side of 10 mm was added and stirring was continued for 5 minutes.
The oil in the oil water and the oil adsorbent were adsorbed (absorbed) by the oil adsorbent in vigorous contact at the center of the swirl flow. The oil adsorbent that has flowed downward due to the swirl flow flows toward the outer periphery at the bottom of the beaker and floats in synchronization with the swirl flow, and is further wound into the swirl flow and repeats the same movement as described above.
At that time, heavy oil adhering to the inner wall surface was also removed cleanly to rub the inner wall surface of the beaker.
After confirming that heavy oil had been removed from the water after 5 minutes from the start of stirring, the magnetic stirrer was stopped, and the oil adsorbent capturing the heavy oil was lightly pinched with tweezers and transferred onto the bat. Even after 1 hour, no heavy oil leaked from the oil adsorbent transferred onto the vat.
[0025]
[Comparative example]
The same beaker was used in the same manner as in the Examples, and the same amount of water and heavy oil were used. The same amount of the same oil adsorbent as in the example was added to heavy oil floating on the water surface. After 5 minutes have passed since the oil adsorbent was added, the oil adsorbent was lightly pinched with tweezers and transferred onto the bat.
During this pulling, some of the water and heavy oil dropped. Heavy oil leaked into the bat after 2 minutes from the bat. In addition, heavy oil in the beaker was not completely adsorbed and partly remained.
[0026]
【Effect of the invention】
According to the method of the present invention, oil components from low concentration to high concentration can be collected in a short time, there is no oil dripping from the oil adsorbent that has captured the oil, and the deoiled oil adsorbent is further reused. can do.
[Brief description of the drawings]
1 is a cross-sectional view of an oil-water treatment tank used in the method of the present invention. FIG. 2 is a cross-sectional view of the bottom of the oil-treatment tank in FIG. 1. FIG. 3 is a cross-sectional view of an oil-water treatment tank used in the method of the present invention. ]
DESCRIPTION OF SYMBOLS 1 ... Oil-water processing tank 2 ... Pipe 3 ... Stirrer 4 ... Discharge port

Claims

In the treated water containing oil, in the presence of the oil adsorbent, a swirl flow having a mortar-shaped concave portion that collects the oil and the oil adsorbent at the center of the swirl flow is generated, and the oils and An oil-water separation method, wherein the oil adsorbent is made to flow downward while being brought into contact with the oil adsorbent in the spiral flow.

The method of separating oil-water according to claim 1, wherein the surface area of the oil sorbent is ^1cm ² ^~2,500cm 2.