JP2004066037A

JP2004066037A - Method of treating waste water of car washing and the like, and recycling method

Info

Publication number: JP2004066037A
Application number: JP2002225713A
Authority: JP
Inventors: Takeshi Hasegawa; 長谷川　健; Tamotsu Hasegawa; 長谷川　保; Shigehito Adachi; 足立　　重仁
Original assignee: WAKAMIYA KOGYO KK
Current assignee: WAKAMIYA KOGYO KK
Priority date: 2002-08-02
Filing date: 2002-08-02
Publication date: 2004-03-04

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forming method of making the aluminum floc obtained by electrolyzing waste water of car washing, etc., larger and a recycling method of converting the waste water of car washing, etc., to water for car washing. <P>SOLUTION: The recycling method of the waste water of car washing, etc., is characterized by electrolyzing the waste water of car washing, etc., in an electrolytic cell 4 using aluminum as an electrode, delivering the scumming of the formed aluminum floc to a next reaction chamber 6 without removing the same, adding a highly bondable polymeric flocculant thereto in the reaction chamber to flocculate the scumming and to allow the scumming to float, then sticking the micro-air bubbles generated from the lower part of a floatation separation vessel to allow the scumming to float, delivering the water by a conveying pump 10, and recycling the water again as service water. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、洗車排水等の排水の電解により生成したアルミニウムフロックに、高分子凝集剤を添加し、微細気泡を付着させて浮上物の完全上昇と排出を図る洗車排水等の排水処理方法及びリサイクル方法に関する。
【０００２】
【従来の技術】
従来、洗車等の排水処理については、例えば、特開平２０００−３３５３７９号公報に洗車廃水リサイクルシステムが提案されている。これは、「洗車機１から洗車廃水分離槽２に流入した洗車廃水ａをリサイクル装置３によって処理し、該リサイクル装置で浄化された水ｂを浄水タンク４に蓄えるようにした洗車廃水リサイクルシステム。前記リサイクル装置の処理能力不足により前記洗車廃水分離槽からオーバーフローする洗浄廃水を貯留槽１０に導入すると共に、該貯留槽に雨水を導入して洗車機で消失した不足分を補充し、しかる後に、前記貯留槽内の水を前記洗車廃水分離槽に戻す。」ことを内容とするものである。
【０００３】
又、特開２０００−２１０６６９号公報に記載された洗車廃水の処理方法および装置は、「沈殿分離槽１により洗車廃水中の土砂を沈殿分離してから、電解槽５に送って、陽極６ａや陰極６ｂと廃水間の界面における電極反応と、この電極反応による生成物が廃水中の成分と反応する二次反応が複合的に行う。電極反応により廃水中の成分が酸化、還元、分解、析出される。二次反応により廃水中の成分の沈降、吸着、凝縮、浮上が行われる。浮遊物質が分離・除去された処理水は、精密濾過装置８により浮遊物質を濾過分離され、貯水槽１１に送られる。」ことを内容とする。
【０００４】
更に、特開平９−１０８５０２号公報には、側溝を流れる廃水に対する浄化装置が提案され、その概要は、「　絶縁性を具えた材料で製しかつ廃水の流通を阻害しないような通水性を有すると共に浄化対象とする側溝Ａの溝内にしっくりと置くことが出きるような横幅を具えて成る直方体状籠体１内の両側部に、互いに極性の異なる電極板４，５を対向させて設け、更に、当該籠体１の下面には、上面に多数の噴気孔を穿設してなる気泡発生盤７を設け、また、上記籠体１内には陽極板と同一材料とする金属廃材６を收装したことを特徴とする側溝を流れる廃水に対する浄化装置。」である。
【０００５】
しかし、特開２０００−３３５３７９洗車廃水リサイクルシステムでは、洗車廃水を電解しつつ、電解浮上させる方法のみでは除去しきれない成分が残る。また特開２０００−２１０６６９洗車廃水の処理方法および装置は、電解浮上物を分離・除去した後に精密濾過する方法であるが、目詰まりが起こり易く、且つランニングコスト上の問題がある。更に、特開平９−１０８５０２の側溝を流れる廃水に対する浄化装置は、電解槽の真下に通常の気泡発生装置を設置する方式であるが、この方法では気泡の口径が大きく且つ粗いので浮上効果が劣るという問題が生じる。
【０００６】
【発明が解決しようとする課題】
そこで本発明は、洗車排水等を電解し、得られたアルミニウムフロックに高分子凝集剤を添加調製することによって、浮上物を大きくする生成方法を提供し、次の工程で該浮上物に微細気泡を付着させて浮上を促進する方法を提供して、浮上物が水と完全分離することによって、洗車排水等を用水へ変換する排水処理方法及びリサイクル方法を提供するものである。
【０００７】
【課題を解決するための手段】
上記目的を達成するために、請求項１記載の発明は、アルミニウムを電極とした電解槽にて排水を電解し、生成されたアルミニウムフロック浮上物を電解槽では除去することなく次の反応槽に送り出し、該反応槽に結合性の強い高分子凝集剤を添加して該浮上物を凝集且つ成長させ、次いで浮上分離槽の下方部から発生する微細な気泡を成長した浮上物に付着させて浮上させ、水と分離して該浮上物を除去することを特徴とする。
【０００８】
請求項２記載の発明は、水に圧力を掛けた状態で強制的に空気を溶解させ、再び大気圧に戻す際に微細な気泡を発生させることにより、該浮上物の下方に該気泡を付着させて浮上させる加圧浮上処理方法を特徴とする。
【０００９】
請求項３記載の発明は、アルミニウムを電極とした電解槽等にて排水を電解し、生成されたアルミニウムフロック浮上物を電解槽では除去することなく次の反応槽に送り出し、該反応槽で結合性の強い高分子凝集剤を添加して該浮上物を凝集且つ成長させ、次いで浮上分離槽の下方部から発生する微細な気泡を成長した浮上物に付着させて浮上させ、水と分離して該浮上物を廃棄した後、水は送水ポンプにて送り出し再び洗車用水としてリサイクルすることを特徴とする。
【００１０】
請求項４記載の発明、水に圧力を掛けた状態で強制的に空気を溶解させ、再び大気圧に戻す際に微細な気泡を発生させることにより、該浮上物の下方に該気泡を付着させて浮上させる加圧浮上処理方法を特徴とする。
【００１１】
【実施例】
この発明の実施例を、図１及び図２に基づいて説明する。
洗車機１からの排水は、油水分離槽２から送水ポンプ３を経て電解装置４に送られる。該電解装置４における洗車排水の電解は、陽極にアルミニウム電極を使用して行われる。アルミニウム電極から溶出するアルミニウムイオンは、水の電解で発生する水酸イオンと反応して水酸化アルミニウムという凝集力のある物質を生じ、これがアルミニウムフロックである。従って、同極に発生する酸素ガスや陰極に発生する水素ガスにより、該フロックや油分、懸濁物質などは幾らか浮上するので、従来は、これを除去する装置を電解装置に付設していた。
【００１２】
この電解装置の中で発生する酸素ガスや水素ガスが、生成された水酸化アルミニウムのフロックや油分、懸濁物質に付着し、該フロックなどを浮上させるが、水酸化アルミニウムフロックの成長には時間が掛かるので、次の反応工程に移した時に大きなフロックとなり、反応槽に沈殿物として残り易く、この状態では、ガソリンスタンドでリサイクルできるような清澄な処理水は得られず、洗車用水として使用できないものであった。
【００１３】
そこでこのフロックを電解装置で除去することなく、次の反応槽６に送る。反応槽６に送られてきた水酸化アルミニウムフロックを含む電解処理水を撹拌羽根で撹拌しながら、水酸化アルミニウムフロック量に応じた高分子凝集剤５を添加し、該凝集剤５の主鎖に点在する反応基と水酸化アルミニウムフロックを反応させて、大きな水酸化アルミニウムフロックに成長させる。
【００１４】
即ち、上記従来方法では、油分等フロックの核となる物質を多く含む浮上物を除去してしまう為、遅れて成長するアルミニウムフロックの分離が困難となっていたが、これを濾過することなく次工程の反応槽に送り、そこで一定量の高分子凝集剤を添加すると、該電解処理水はアルミニウムフロック沈殿物などフロックの核になる物質が多くあるので、適切な量の高分子凝集剤と出会って反応し、充分に大きなアルミニウムフロックが生成できる。
【００１５】
該高分子凝集剤としては、ポリアクリルアミド系、ポリアクリル酸系、変性ポリアクリルアミド系などのアニオン系高分子凝集剤を使用し、またノニオン系の高分子凝集剤もその効果が認められた。而して該フロックは大きく成長する。
【００１６】
次に、その大きく成長したフロックを、反応処理水と共にフロック浮上分離槽７に移す。該浮上分離槽７の底部に配水管を施設し、底部にある反応処理水を別のタンクに移して、その一部を泡発生ポンプ８で加圧する。該泡発生ポンプ８で圧力を掛けた状態で強制的に空気を溶解させる。それを再び大気圧に戻して微細気泡を発生させ、該微細気泡を浮上分離槽７で放出すると共に、フロックに付着させて浮上を促進する。
該浮上分離槽７の下方で発生させる気泡１２は微細なので、該アルミニウムフロックに付着し易く、微細気泡１２が付着した該フロックは見かけ比重が小さくなるので、水面に向かって上昇する。尚、１１は、余剰エア分離塔である。
【００１７】
浮上分離槽７の水面に浮上したフロックは回収されるに従って、水と完全に分離される。該処理水はリサイクルされた水として送水ポンプ１０にて再び洗車機１に戻され、ガソリンスタンド等で利用され得る。
【００１８】
【試験例】
ガソリンスタンドの洗車排水を採取し、基本的な処理条件は同じとして、表１に示すような原水と、２つの方法での処理水の透視度について比較検討を行った。
【００１９】
【表１】

【００２０】
上記の透視度比較のように、従来法の電解処理→加圧浮上処理では、原水と比較して透視度は改善されるものの、除去されないフロックが処理水▲１▼に浮遊しており、これが透視度を悪くする原因であった。これに対して、本発明の方法で得られた処理水▲２▼は、浮遊フロックがほとんど観察されず、無色で、透視度も５０度以上確保できており、洗車用に充分リサイクルができる水質となった。
【００２１】
更に、洗車された排水と浄化処理した処理水を分析した結果は、表２に示すとおりである。洗車用水の水質基準値は定められていないので、比較のための参考値を表の右欄に併記した。処理水は、透明度が極めて高く肉眼では新しい水とほとんど変わらず、臭気も全くない。ＳＳ、濁度、油脂分等、洗車用水として再利用するには適正な水質となった。
【００２２】
【表２】

【００２３】
【発明の効果】
本発明は、洗車排水から油分、懸濁物質などが効率よく分離できたので、水は洗車用水等としてリサイクルでき、水の再利用が可能となった。水の費用節約はもちろん、水道水を大量に必要としなくなる。従来の垂れ流し状態では環境を汚染していたものを解決できる。又、リサイクルに限定されず、排水処理方法として有効である。
【００２４】
又、洗車排水以外にもこの原理を利用して、油脂含有排水、洗米排水、金属含有排水などの排水処理及びリサイクルが可能である。
【図面の簡単な説明】
【図１】本発明の１実施例を示す洗車排水リサイクル方法の系統図である。
【図２】加圧水ユニットの概略フロー図である。
【符号の説明】
１　　　洗車機
２　　　油水分離機
３　　　原水槽水
４　　　電界槽
５　　　高分子凝集剤
６　　　反応槽
７　　　浮上分離槽
８　　　泡発生ポンプ
９　　　処理水
１０　　送水ポンプ
１１　　余剰エア分離塔
１２　　微細気泡[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for treating and recycling wastewater from car washing wastewater, which adds a polymer flocculant to aluminum flocs generated by electrolysis of wastewater such as carwash wastewater and attaches fine bubbles to completely raise and discharge floating materials. About the method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for wastewater treatment of a car wash or the like, a car wash wastewater recycling system has been proposed in Japanese Patent Application Laid-Open No. 2000-335379, for example. This is a “car wash waste water recycling system in which car wash waste water a that has flowed into the car wash waste water separation tank 2 from the car wash machine 1 is processed by the recycling device 3 and the water b purified by the recycling device is stored in the water purification tank 4. In addition to introducing washing wastewater overflowing from the carwash wastewater separation tank into the storage tank 10 due to lack of processing capacity of the recycling device, rainwater is introduced into the storage tank to replenish the shortage that has been lost in the car washer, and thereafter, The water in the storage tank is returned to the car wash wastewater separation tank. "
[0003]
Further, the method and apparatus for treating car wash wastewater described in Japanese Patent Application Laid-Open No. 2000-210669 are described as follows: "sedimentation of sediment in carwash wastewater is settled and separated by the sedimentation separation tank 1 and then sent to the electrolytic tank 5 where the anode 6a An electrode reaction at the interface between the cathode 6b and the wastewater and a secondary reaction in which a product of the electrode reaction reacts with a component in the wastewater are performed in a complex manner, and the components in the wastewater are oxidized, reduced, decomposed, and precipitated by the electrode reaction. The components in the wastewater are settled, adsorbed, condensed, and floated by the secondary reaction, and the treated water from which the suspended matter has been separated and removed is subjected to filtration and separation of the suspended matter by the microfiltration device 8, and the water storage tank 11. Will be sent to. "
[0004]
Further, Japanese Patent Application Laid-Open No. 9-108502 proposes a purifying apparatus for wastewater flowing through a gutter. The outline of the purifying apparatus is as follows: "It is made of a material having an insulating property and has water permeability so as not to hinder the flow of the wastewater. At the same time, electrode plates 4 and 5 having different polarities are provided on both sides of the rectangular parallelepiped basket 1 having a width such that it can be easily placed in the groove of the side groove A to be purified. Further, on the lower surface of the basket 1, there is provided a bubble generating plate 7 having a large number of blast holes formed on the upper surface, and a metal waste material 6 made of the same material as the anode plate is provided in the cage 1. And a purifying device for wastewater flowing through the gutter. "
[0005]
However, in the car wash wastewater recycling system of Japanese Patent Application Laid-Open No. 2000-335379, components that cannot be completely removed only by the method of electrolyzing the carwash wastewater while electrolyzing the carwash wastewater remain. Japanese Patent Application Laid-Open No. 2000-210669, which describes a method and an apparatus for treating car wash wastewater, is a method for separating and removing electrolytically suspended matter and then performing fine filtration. However, the method tends to cause clogging and has problems in running costs. Further, the apparatus for purifying wastewater flowing in a gutter disclosed in Japanese Patent Application Laid-Open No. 9-108502 is a system in which a normal bubble generator is installed immediately below an electrolytic cell. However, in this method, the bubble diameter is large and coarse, so that the floating effect is inferior. The problem arises.
[0006]
[Problems to be solved by the invention]
Therefore, the present invention provides a production method for enlarging a floating material by electrolyzing car wash drainage and the like, and adding and preparing a polymer flocculant to the obtained aluminum floc. The present invention provides a method for promoting the floating by adhering water, and a wastewater treatment method and a recycling method for converting car wash wastewater or the like into service water by completely separating floating material from water.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 electrolyzes waste water in an electrolytic cell using aluminum as an electrode, and removes the generated aluminum floc floating matter to the next reaction tank without removing it in the electrolytic cell. The floating substance is aggregated and grown by adding a polymer flocculant having a strong binding property to the reaction tank, and then the fine bubbles generated from the lower part of the flotation separation tank are attached to the grown floating substance to float. And separating from the water to remove the floating material.
[0008]
According to the second aspect of the present invention, air is forcibly dissolved in a state where water is applied with pressure, and fine bubbles are generated when the pressure is returned to the atmospheric pressure again. The method is characterized by a pressure levitation processing method of causing the levitation to float.
[0009]
According to the third aspect of the present invention, the wastewater is electrolyzed in an electrolytic cell or the like using aluminum as an electrode, and the generated aluminum floc floating material is sent to the next reaction tank without being removed in the electrolytic tank, and is combined in the reaction tank. A strong polymer flocculant is added to cause the flotation to coagulate and grow, and then fine bubbles generated from the lower part of the flotation tank adhere to the grown flotation and float, and are separated from water. After discarding the floating material, the water is sent out by a water pump and recycled again as car wash water.
[0010]
The invention according to claim 4, wherein by forcibly dissolving the air while applying pressure to the water and generating fine bubbles when returning to atmospheric pressure again, the bubbles are attached below the floating material. The method is characterized by a pressurized levitation treatment method for levitation.
[0011]
【Example】
An embodiment of the present invention will be described with reference to FIGS.
Drainage from the car washer 1 is sent from the oil / water separation tank 2 to the electrolysis device 4 via the water pump 3. The electrolysis of car wash drainage in the electrolyzer 4 is performed using an aluminum electrode as an anode. Aluminum ions eluted from the aluminum electrode react with hydroxyl ions generated in the electrolysis of water to produce aluminum hydroxide, a cohesive substance, which is aluminum floc. Therefore, the flocs, oils, suspended substances, and the like float to some extent due to the oxygen gas generated at the same pole and the hydrogen gas generated at the cathode. .
[0012]
Oxygen gas and hydrogen gas generated in this electrolytic device adhere to the generated aluminum hydroxide flocs, oils, and suspended solids, causing the flocs to float, but the growth of the aluminum hydroxide flocs takes time. , It becomes a large floc when it is transferred to the next reaction step, and it tends to remain as a precipitate in the reaction tank. In this state, clear treated water that can be recycled at the gas station can not be obtained and can not be used as car wash water Was something.
[0013]
Therefore, this floc is sent to the next reaction tank 6 without being removed by the electrolytic device. While agitating the electrolytically treated water containing aluminum hydroxide flocs sent to the reaction tank 6 with stirring blades, a polymer coagulant 5 according to the amount of aluminum hydroxide flocs is added, and the main chain of the coagulant 5 is added to the main chain. The scattered reactive groups react with aluminum hydroxide flocs to grow into large aluminum hydroxide flocs.
[0014]
That is, in the above-mentioned conventional method, it is difficult to separate the aluminum floc that grows late because it removes a floating substance containing a large amount of a substance that becomes a core of the floc such as an oil. When a certain amount of the polymer flocculant is added to the reaction tank in the process, and the electrolyzed water contains a large amount of floc nuclei such as aluminum floc sediment, it encounters an appropriate amount of the polymer flocculant. To produce a sufficiently large aluminum floc.
[0015]
As the polymer flocculant, an anionic polymer flocculant such as polyacrylamide, polyacrylic acid, and modified polyacrylamide was used, and a nonionic polymer flocculant was also effective. Thus, the flocs grow greatly.
[0016]
Next, the floc that has grown greatly is transferred to the floc flotation tank 7 together with the reaction water. A water distribution pipe is provided at the bottom of the flotation tank 7, the reaction water at the bottom is transferred to another tank, and a part thereof is pressurized by the foam generation pump 8. The air is forcibly dissolved while the pressure is applied by the foam generating pump 8. The pressure is returned to the atmospheric pressure again to generate fine bubbles, and the fine bubbles are released in the flotation / separation tank 7 and adhere to the flocs to promote the flotation.
Since the bubbles 12 generated below the flotation tank 7 are fine, they easily adhere to the aluminum flocks, and the flocs to which the fine bubbles 12 adhere have a small apparent specific gravity, so that they rise toward the water surface. In addition, 11 is a surplus air separation tower.
[0017]
The flocs floating on the surface of the floating separation tank 7 are completely separated from water as they are recovered. The treated water is returned to the car washer 1 again by the water pump 10 as recycled water, and can be used at a gas station or the like.
[0018]
[Test example]
Car wash drainage from a gas station was collected, and the basic treatment conditions were the same, and the raw water as shown in Table 1 and the transparency of treated water by the two methods were compared and examined.
[0019]
[Table 1]

[0020]
As in the above comparison of the degree of transparency, in the conventional electrolytic treatment → pressurized levitation treatment, although the degree of transparency is improved as compared with the raw water, the flocs that are not removed float in the treated water (1). This was the cause of poor visibility. On the other hand, the treated water (2) obtained by the method of the present invention has almost no floating flocs, is colorless, has a transparency of 50 ° or more, and can be sufficiently recycled for car washing. It became.
[0021]
Further, the results of analyzing the car-washed wastewater and the treated water subjected to the purification treatment are as shown in Table 2. Since there is no standard value for water quality for car washing, reference values for comparison are also shown in the right column of the table. The treated water has extremely high transparency, is almost the same as fresh water to the naked eye, and has no odor. The water quality was appropriate for reuse as car wash water, such as SS, turbidity, and oil content.
[0022]
[Table 2]

[0023]
【The invention's effect】
According to the present invention, oil and suspended substances can be efficiently separated from car wash drainage, so that water can be recycled as car wash water and the like, and water can be reused. Water savings, as well as the need for large amounts of tap water. What was polluting the environment in the conventional run-off state can be solved. Further, the present invention is not limited to recycling but is effective as a wastewater treatment method.
[0024]
By utilizing this principle, wastewater treatment and recycling of oil-and-fat wastewater, rice washing wastewater, metal-containing wastewater and the like other than car wash wastewater are possible.
[Brief description of the drawings]
FIG. 1 is a system diagram of a car wash drainage recycling method showing one embodiment of the present invention.
FIG. 2 is a schematic flow chart of a pressurized water unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Car wash machine 2 Oil-water separator 3 Raw water tank water 4 Electric field tank 5 Polymer flocculant 6 Reaction tank 7 Floating separation tank 8 Foam generation pump 9 Treated water 10 Water supply pump 11 Excess air separation tower 12 Fine air bubbles

Claims

The wastewater is electrolyzed in an electrolytic cell using aluminum as an electrode, and the generated aluminum floc floating material is sent out to the next reaction tank without being removed in the electrolytic tank, and a polymer flocculant having strong binding properties is added to the reaction tank. Wastewater treatment method, wherein the floating material is aggregated and grown, and then fine bubbles generated from the lower part of the floating separation tank are attached to the grown floating material and floated, and the floating material is removed. .

A pressure levitation process that forcibly dissolves air while applying pressure to water and generates fine air bubbles when returning to atmospheric pressure again, causing air bubbles to adhere to the floating object and float. The wastewater treatment method according to claim 1.

The wastewater is electrolyzed in an electrolytic cell using aluminum as an electrode, and the generated aluminum floc floating material is sent to the next reaction tank without being removed in the electrolytic tank, and a polymer flocculant having strong binding properties is added in the reaction tank. Then, the floating material is aggregated and grown, and then fine bubbles generated from the lower part of the flotation tank are attached to the grown floating material and floated, and the water is sent out by a water pump to be recycled again as water. Characteristic wastewater recycling method.

A pressure levitation process in which air is forcibly dissolved while pressure is applied to water, and fine bubbles are generated when the pressure is returned to the atmospheric pressure again, whereby the bubbles are attached to and floated below the floating object. 4. The method for recycling car wash drainage according to claim 3, wherein the method is used.