JP2000210669A - Treatment of car washing waste water and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treating method and its inexpensive device for car wash ing water which is capable of purifying the water to the degree capable of being reused as car washing water, and which is expected to be used widely by a gasoline stations, etc. SOLUTION: The earth and sand in the car washing water is settled and separated in a settling and separating tank 1, then the waste water is sent to an electrolytic cell 5. Electrode reaction at the interface between an anode, a cathode and the waste water as well as the secondary reaction in which the product by the electrode reaction is allowed to react with the component in the waste water are executed compositely. The component in the waste water is oxidized, reduced, decomposed and settled by the electrode reaction. The settling, adsorption, condensation and floatation of the component in the waste water occurs in the secondary reaction. The treated water from which a suspended substance is separated and removed is subjected to filtering to separate the suspended substance by a precision filter device 8 and sent to a water storage tank 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for treating car wash wastewater.

[0002]

2. Description of the Related Art Generally, at a gas station or the like, operations such as car washing, high-pressure water injection, brushing, and waxing by a portal type device are automatically and continuously performed. Also, in a coin car wash, etc., the above car wash work and the like are performed manually. These car wash operations generate a large amount of car wash wastewater. Conventionally, car wash wastewater has been drained to the sewer as it is, or, for example, after separating oil and fat and soil and sand from wastewater by a simple treatment device such as a floating separation type oil trap, and then drained to sewage. .

[0003] However, in the recent era of emphasis on environmental protection, the wastewater is naturally drained, and the purification by the oil trap or the like is insufficient, so that the wastewater standard cannot be sufficiently satisfied. In addition, the car wash wastewater contains synthetic detergents (surfactants) in addition to the oils and fats and the earth and sand, and cannot be removed by the above-described conventional apparatus. If so, foaming would be required, and improvement was requested. further,
The conventional apparatus described above has problems that it is not only large and occupied but also expensive and cannot be widely used in gas stations and the like.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has been made to meet the above-mentioned demands. It is an object of the present invention to provide a method and an apparatus for treating car wash wastewater, which can be purified to a certain extent, are inexpensive, and easily spread to gas stations and the like.

[0005]

SUMMARY OF THE INVENTION The method for treating car wash wastewater of the present invention comprises subjecting the car wash wastewater to an electrode reaction to oxidize the components thereof.
In addition to reducing, decomposing and precipitating, the secondary reaction between the product of the above-mentioned electrode reaction and the components in the wastewater causes the components to settle, adsorb, condense, float and separate and remove from the wastewater. It is characterized in that suspended substances in the treated water are separated and removed by a microfiltration device. It is also characterized in that the above-mentioned electrode reaction is performed after sedimentation of sediment.

Further, in the apparatus for treating car wash wastewater according to the present invention, an electrode is installed inside the carwash wastewater to cause an electrode reaction of the carwash wastewater to oxidize, reduce, decompose, and precipitate the components, and the product of the above-mentioned electrode reaction and the wastewater. Settle, adsorb, condense and float by secondary reaction with the component
It is characterized by comprising an electrolytic cell to be removed and a microfiltration device for microfiltering the treated water from the electrolytic cell. It is also characterized in that a sedimentation separation tank for sedimentation and separation of earth and sand is provided in front of the electrolytic cell.

[0007]

1 is an explanatory view showing one embodiment of the apparatus of the present invention. Reference numeral 1 denotes a sedimentation / separation tank for sedimenting earth and sand in car wash wastewater flowing from an inflow pipe 2. Wastewater after sedimentation of sediment is mainly composed of water, oil and fats such as mineral oil and wax, small droplets of detergents such as ABS (alkyl benzene sulfonate) synthetic detergents, and suspended particles such as suspended solids (SS). Is contained in the emulsion.

The wastewater in the sedimentation separation tank 1 is sent to an electrolytic tank 5 by a water supply pump 4 through a water supply pipe 3. In addition,
When the sedimentation separation tank 1 is located above the electrolysis tank 5, the water supply pump 4 may be omitted.

The electrolytic cell 5 is divided into an electrolytic chamber 5b and a sedimentation chamber 5c by a horizontal partition plate 5a. In this embodiment,
The electrolytic chamber 5b is partitioned by a partition 5d. The electrolysis chamber 5b and the precipitation chamber 5c communicate with each other through an opening 5a 'formed in the floor plate 5a. The horizontal partition 5
a or a large number of openings may be formed in the partition wall 5d to increase the water permeability, or may be omitted.

An electrode 6 as shown in FIG. 2 is provided in the electrolytic chamber 5b of the electrolytic cell 5. The electrodes 6 are arranged alternately in parallel with a pair of anode plates 6a and cathode plates 6b (three pairs in this embodiment), and are integrally formed by connecting bolts 6c. The connection bolt 6c and each electrode plate (6a, 6b) are electrically insulated. An anode bolt 6d is electrically connected to the anode plate 6a and is electrically connected to the cathode plate 6b as shown in FIG. 2 (B).
Insulated by Similarly, the cathode bolt 6e is connected only to the cathode plate 6b. For example, a direct current of 6 to 12 V is applied between the anode bolt 6d and the cathode bolt 6e. When using commercial AC power, it is applied via a suitable rectifier and transformer (not shown). The material of the electrode plates 6a and 6b may be any of conventionally known materials such as aluminum, titanium and iron.

When a direct current is passed through the wastewater flowing into the electrolytic chamber 5b, an electrode reaction at the interface between the anode 6a or the cathode 6b and the wastewater, and a product of the electrode reaction reacts with a component in the wastewater. The secondary reaction is performed in a complex manner. The components in the wastewater are oxidized, reduced, decomposed, and precipitated by the electrode reaction. Further, the components in the wastewater are settled, adsorbed, condensed, and floated by the secondary reaction.

In the above-mentioned electrode reaction, the emulsion and metal ions in the wastewater undergo ionic neutralization (decomposition) by an electron reaction (electric field) occurring between the above-mentioned electrodes 6 and are separated, and the oil floats. Further, the metal ions are insoluble by binding to the hydroxide ions.

In particular, oxygen gas is generated from the anode 6a, and hydrogen gas is generated and raised from the cathode 6b, respectively, to raise the oil content in the wastewater, and to cause the floating substance (S
S) and floats on the water surface. The floating oil and suspended substances are adsorbed by an adsorbent (not shown) or the like, or removed by a suitable scraping means or the like.

The treated water from which the suspended substances have been separated and removed is sent to a microfiltration device 8 through a water pipe 7. 9 is a water pump. For example, as shown in FIG. 3, the microfiltration device 8 accommodates a filter 8b, which is formed by laminating a large number of disks formed of a filter material such as natural fiber and formed into a cylindrical shape, in a sealed container 8a. Then, the suspended matter that cannot be completely removed in the electrolytic cell 5 is separated by filtration. The filtration device is not limited to the above-mentioned device 8, but may be any device capable of separating and removing fine suspended substances and colloidal substances.

The purified water filtered by the microfiltration device 8 is sent to a water storage tank 11 through a water pipe 10 and reused as washing water as required.

[0016]

According to the method of the present invention, it is possible to sufficiently purify the water to such an extent that it can be reused as car wash water, and it is possible to provide an apparatus which is inexpensive and easily spread to gas stations and the like.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a device for treating car wash wastewater of the present invention.

FIG. 2 is a perspective view showing a configuration example of an electrode.

FIG. 3 is a cross-sectional view illustrating an embodiment of the filtration device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Precipitation separation tank 2 Inflow pipe 3 Water supply pipe 4 Water supply pump 5 Electrolysis tank 5a Horizontal partition plate 5b Electrolysis chamber 5c Precipitation chamber 5d Partition wall 5d 'Notch 6 Electrode 6a Anode plate 6b Cathode plate 6c Connection bolt 6d Anode bolt 6e Cathode bolt 6f Insulation pipe 7 Water supply pipe 8 Microfiltration device 8a Sealed container 8b Filter 9 Water supply pump 10 Water supply pipe 11 Storage tank

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D061 DA08 DB15 DB19 DC01 DC02 DC09 DC11 EA03 EA04 EA07 EA08 EB04 EB11 EB17 EB18 EB20 EB27 EB28 EB30 FA09 FA14 4D062 BA19 BB01 CA10 EA32 FA13 FA17 FA22 FA24

Claims (4)

[Claims] 1. An electrode reaction of car wash wastewater to oxidize, reduce, decompose, and precipitate its components, and sedimentation, adsorption, and condensation of the components by a secondary reaction between the product of the electrode reaction and components in the wastewater. A method for treating car wash wastewater, comprising separating and removing the suspended matter in the treated water after separation and removal using a microfiltration device. 2. The method for treating car wash wastewater according to claim 1, wherein said electrode reaction is carried out after sedimentation of sediment. 3. An electrode is installed in the interior to cause car wash wastewater to undergo an electrode reaction to oxidize, reduce, decompose, and precipitate the components, and a secondary reaction between a product of the electrode reaction and a component in the wastewater causes the components to react. An electrolytic cell for separating and removing water from wastewater by settling, adsorbing, condensing, and floating water, and a microfiltration device for microfiltrating the treated water from the electrolytic cell, a car washing wastewater treatment apparatus. 4. The apparatus for treating car wash wastewater according to claim 3, wherein a sedimentation separation tank for sedimenting and separating earth and sand is provided before the electrolytic cell.