KR102458775B1 - Sewage disposal apparatus having non-powered scum removing function - Google Patents

Abstract

The sewage treatment apparatus according to the present invention comprises: a bioreactor in which a biological treatment process is performed; It has a closed chamber shape, a sewage supply pipe through which sewage is introduced from the outside, a venturimeter that delivers the treated water inside to the bioreactor, and a cathode and anode are cross-arranged and installed on the bottom side of the inner space an electrolytic flotation tank having an electrolytic oxidation module; a scum collecting chamber in which scum is collected; a scum flow pipe configured to connect the ceiling surface of the electrolytic flotation tank and the upper side of the scum collecting chamber, and deliver the scum in the electrolytic flotation tank to the scum collecting chamber; It is configured to include an air suction pipe that supplies external air to a portion of the venturimeter in which the flow path is narrowed, and the middle part communicates with the scum collecting chamber. Using the sewage treatment device according to the present invention, ammonia in sewage can be removed by electrolysis, scum can be collected and removed without a separate scum removal device, and the amount of scum can be adjusted according to the increase or decrease of the amount of scum generated. There is an advantage in that the dissolved oxygen concentration of the treated water in the electrolytic flotation tank can be increased.

Description

Sewage treatment device with non-powered scum removal function {SEWAGE DISPOSAL APPARATUS HAVING NON-POWERED SCUM REMOVING FUNCTION}

The present invention relates to a sewage treatment device that removes ammonia in sewage by electrolysis and flotation to remove scum, and more particularly, to a sewage treatment device capable of collecting and removing scum without a separate scum removal device. .

In general, as residential life becomes more convenient, interest in environmental pollution is increasing, and it is a well-known fact that people want to live in a cleaner and sanitary environment. In order to meet these demands, various efforts are being made, such as the development of sewage and wastewater treatment devices for purifying river water, which is a water source, and treatment devices of water and sewage.

The treatment devices are purified through various processes (eg, mixing/agglomeration process, chemical treatment process, precipitation process, filtration process, sterilization process), etc. Various studies on water treatment technology are being conducted.

In particular, in the purification process and wastewater treatment process, the mixing/agglomeration process for the effective flotation principle in the flotation tank by forming a floe of suspended matter and colloidal material in water is a very important process that determines the treatment effect of the subsequent process to be.

After the mixing/agglomeration process, the 'precipitation method' is usually used as the turbidity removal process, which is the previous step of the filtration process. However, when raw water such as lake water containing a large amount of algae and light-density particles is used as raw water, the treatment efficiency in the precipitation process is very low, causing serious problems in operation and management such as early blockage in the filtration process, which is a subsequent process. . Accordingly, in recent years, there has been proposed a sewage treatment apparatus that attaches and floats air bubbles to the flock so that scum is generated on the water surface and then collects and removes the scum in this way.

Hereinafter, a conventional sewage treatment apparatus will be described in detail with reference to the accompanying drawings.

1 is a schematic view of a conventional sewage treatment apparatus.

As shown in FIG. 1, the conventional sewage treatment apparatus generates a scum having buoyancy by spraying air bubbles into a mixing tank 10 that mixes chemicals with sewage supplied from the outside, and the sewage that has passed through the mixing tank 10. A flotation separation tank 20 that makes a And, a pressure tank 50 that pressurizes a portion of the supernatant water drawn from the floating separation tank 20 and supplies it to the bubble injector 30, and the pressurized tank so that air is dissolved in the supernatant water supplied by the pressurization tank 50 It is configured to include an air supply device (60) for supplying air to (50). If the conventional sewage treatment apparatus configured as described above is used, the contaminants in the sewage can be floated to the surface and then removed by the scum remover 40, so there is an advantage of efficiently purifying the sewage.

However, the conventional sewage treatment apparatus includes a scum removal device 40 operated by power supplied from the outside, a pressurized tank 50 for compressing supernatant water to high pressure, and a separate air supply device 60 for supplying air. Since it is essential, there is a problem in that the facility capacity increases and the operating cost increases.

In addition, in the case of a conventional sewage treatment system, when the water temperature is lowered as in winter, the biological treatment efficiency is reduced as the activity of microorganisms is lowered, and accordingly, BOD and COD increase, so that normal water treatment cannot be performed. There is a downside to being

KR 20-0252231 Y1

The present invention has been proposed to solve the above problems, and although ammonia in sewage is removed by electrolysis, scum can be collected and removed without a separate scum removal device, and the dissolved oxygen concentration of the treated water in the electrolytic flotation tank is increased. An object of the present invention is to provide a sewage treatment system that can

A sewage treatment apparatus according to the present invention for achieving the above object includes: a bioreactor in which a biological treatment process is performed; It has a closed chamber shape, a sewage supply pipe through which sewage is introduced from the outside, a venturimeter that delivers the treated water inside to the bioreactor, and a cathode and anode are cross-arranged and installed on the bottom side of the inner space an electrolytic flotation tank having an electrolytic oxidation module; a scum collecting chamber in which scum is collected; a scum flow pipe configured to connect the ceiling surface of the electrolytic flotation tank and the upper side of the scum collecting chamber, and deliver the scum in the electrolytic flotation tank to the scum collecting chamber; It is configured to include an air suction pipe that supplies external air to a portion of the venturimeter in which the flow path is narrowed, and the middle part communicates with the scum collecting chamber.

It further includes a flow tube valve for controlling the opening amount of the scum flow tube, and a suction tube valve for adjusting the opening amount of the air intake tube.

It is mounted on the ceiling surface of the electrolytic flotation tank, further comprising a pressure sensor for sensing the scum pressure in the electrolytic flotation tank, the flow pipe valve to adjust the opening degree of the scum flow pipe in proportion to the scum pressure in the electrolytic flotation tank It works.

It further includes a water level sensor for detecting the water level of the electrolytic flotation tank, and a venturi valve for increasing or decreasing the opening degree of the venturimeter so that the water level of the electrolytic flotation tank is maintained within a preset range.

The venturi valve is configured to periodically increase or decrease the opening degree of the venturi meter after a predetermined time has elapsed from the start of the supply of sewage water and the operation of the electrolytic oxidation module to periodically discharge the scum in the electrolytic flotation tank.

It further includes a sewage supply pump for compressing the sewage supplied from the outside to a pressure of a preset size and supplying the sewage supply pipe to the sewage supply pipe.

The ceiling surface of the electrolytic flotation tank is formed to be inclined in a direction in which the height increases toward the point where the scum flow tube is connected.

Using the sewage treatment device according to the present invention, ammonia in sewage can be removed by electrolysis, scum can be collected and removed without a separate scum removal device, and the amount of scum can be adjusted according to the increase or decrease of the amount of scum generated. There is an advantage in that the dissolved oxygen concentration of the treated water in the electrolytic flotation tank can be increased.

1 is a schematic view of a conventional sewage treatment apparatus.
2 is a schematic diagram of a sewage treatment apparatus according to the present invention.
3 and 4 are diagrams of the state of use of the sewage treatment apparatus according to the present invention.
5 is a schematic diagram of a second embodiment of a sewage treatment apparatus according to the present invention.
6 is a schematic diagram of a third embodiment of a sewage treatment apparatus according to the present invention.

Hereinafter, an embodiment of a sewage treatment apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic diagram of a sewage treatment apparatus according to the present invention, and FIGS. 3 and 4 are diagrams of a state of use of the sewage treatment apparatus according to the present invention.

The sewage treatment device according to the present invention removes ammonia in the sewage by electrolysis and floats the scum to remove it, but the biggest feature is that the scum floating on the surface can be collected and removed without a separate scum removal device. There is this.

That is, in the sewage treatment apparatus according to the present invention, the bioreactor 200 in which the biological treatment process is performed, the electrolysis method to remove ammonia in the sewage, and at the same time attach the gas to the contaminants in the sewage to raise the scum (S) above the water surface. The electrolytic flotation tank 100 configured to float, the scum collecting chamber 400 in which the scum (S) is collected, the ceiling surface of the electrolytic flotation tank 100 and the upper side of the scum collecting chamber 400 The scum flow pipe 500 configured to connect the scum in the electrolytic flotation tank 100 to the scum collecting chamber 400, and the venturimeter 300 to the part where the flow path is narrowed. However, there is a feature in the configuration in that the middle section is configured to include an air intake pipe 310 communicating with the scum collecting chamber 400 .

The electrolytic flotation tank 100 has a closed chamber shape on all sides, a sewage supply pipe 120 through which sewage is introduced from the outside, and a venturimeter 300 that delivers the treated water inside the bioreactor 200 to the bioreactor 200 . and an electrolytic oxidation module 110 formed so that the cathode and the anode are cross-arranged and installed on the bottom side of the inner space.

In this case, the electrolytic oxidation module 110 has a structure in which a cathode and an anode are cross-arranged, the anode may be manufactured by mixing carbon nanotubes and epoxy, and the anode may be manufactured in a structure in which iridium oxide is coated on titanium metal. can As described above, the electrolytic oxidation module 110 having a structure in which the cathode and the anode are cross-arranged to cause an electrolytic oxidation action has been proposed in various structures in the field of water treatment. Detailed description will be omitted.

As described above, the electrolysis tank in which the electrolytic oxidation module 110 is built-in enables total nitrogen treatment regardless of the water temperature through the electrolytic nitrogen oxide removal mechanism. That is, the removal of ammonia nitrogen in sewage by electrolysis is achieved through the simultaneous effects of direct anodization and indirect anodization, similar to organic material oxidation.

Direct oxidation of ammonia nitrogen by electrolysis is as follows [Formula 1].

[Formula 1]

NH ₃ + 3OH ^- → 0.5N ₂ + 3H ₂ O + 3e ^-

That is, ammonia removal occurs at the anode and is oxidized to nitrogen gas while generating trivalent electrons at a faradic efficiency of nearly 100%. Nitrous acid and nitric acid are produced as intermediate products of ammonia oxidation as shown in the following [Formula 2] and [Formula 3] according to the water concentration of OH ^- .

[Formula 2]

NH ₃ + 7OH ^- → NO ₂ ^- + 5H ₂ O + 6e ^-

[Formula 3]

NH ₃ + 9OH ^- → NO ₃ ^- + 6H ₂ O + 8e ^-

In addition, chlorine liberated by indirect reaction reacts with ammonia nitrogen to generate nitrogen gas as a final product as shown in the following [Formula 4].

[Formula 4]

2NH ₄ ⁺ + 3HOCl ^- → N ₂ + 3H ₂ O + 5H ⁺ + 3Cl ^-

In addition, in the electrolysis tank, it is possible to remove residual organic substances in the effluent due to the 'organic substance removal mechanism' of electrolytic oxidation. That is, as shown in the following [Formula 5] and [Formula 6], in the electrolysis of an organic material, metal ions in an acidic solution are oxidized from a stable state to an excited state during the electrolysis process, and a reactant as an intermediate product is generated.

[Formula 5]

xMN ⁺ → xM(N ⁺¹ ) + xe ^-

[Formula 6]

xM(N ⁺¹ ) + reacting agent → xMN ⁺ + yCO ₂

In addition, although electrolysis of organic materials is oxidized at the anode, direct oxidation in which hydroxide ions are adsorbed on the electrode surface by electrolysis of water to oxidize organic materials, and indirect by intermediate products such as hypochlorous acid generated by electrolysis of chlorine oxidation can be distinguished.

For organic material removal by direct oxidation, hydroxide ions generated by electrolysis of water on the electrode surface (M[ ]) are adsorbed to the anode as shown in [Formula 7] below.

[Formula 7]

H ₂ O + M[ ] → M[OH ^- ] + H ⁺ + e ^-

The organic material is oxidized by the hydroxide ions absorbed and incorporated on the electrode surface.

[Formula 8]

R + M[OH ^- ] → M[ ] + RO + H ⁺ + e ^-

Here, RO is an organic material that is oxidized by continuously formed hydroxide ions and continues the anode discharge in water. The organic matter removal mechanism of electrolysis is as follows. First, as shown in the following [Formula 9] and [Formula 10], the anode (MOX+1) which is further oxidized by adsorption of hydroxide ions generated by the electrolysis of water to the oxidized anode (MOX) and reacting with the already generated oxygen (MOX+1) to form

[Formula 9]

MOX + H ₂ O → MOX[OH ^- ] + H ⁺ + e ^-

[Formula 10]

MOX [OH ^- ] → MOX ⁺¹ + H ⁺ + e ^-

In addition, the organic material (R) reacts with the hydroxide ions adsorbed on the oxidizing anode and is decomposed into carbon dioxide, water, or hydrogen ions as shown in the following [Formula 11].

[Formula 11]

R + MOX [OH ^- ]z → CO ₂ + zH ⁺ + ze ^- + MOX

In the electrochemical reaction of the organic material removed by indirect oxidation, anodic oxidation of chlorine occurs simultaneously during electrolysis as shown in [Formula 12] below, and hypochlorous acid is formed on the electrode surface.

[Formula 12]

H ₂ O + M[ ] + Cl ^- → M[HOCl] + H ⁺ + 2e ^-

At this time, the reaction in which the organic material is oxidized by hypochlorous acid generated at the anode is shown in [Formula 13] below.

[Formula 13]

R + M [HOCl] → M[ ] + RO + H ⁺ + Cl ^- + 2e ^-

In the electrolytic oxidation reaction process as described above, gases such as hydrogen and oxygen are generated. In the sewage treatment apparatus according to the present invention, hydrogen and oxygen generated in the electrolytic oxidation module 110 are attached to the contaminants in the sewage, and the contaminants are transferred to the surface of the water. It plays a role of floating, that is, converting pollutants in the water into scum (S). Therefore, the sewage treatment apparatus according to the present invention has the advantage that it is possible to float contaminants in the sewage water without a separate bubble injector 30 , a pressure tank 50 , and an air supply device 60 (see FIG. 1 ).

In addition, since the conventional sewage treatment apparatus requires a separate scum removal apparatus 40 (see FIG. 1 ) such as a skimmer to remove the scum (S) suspended on the water surface, the overall structure becomes complicated and miniaturized. It is difficult to operate, and there are disadvantages in that operation and maintenance costs are high. However, the electrolytic flotation tank 100 included in the sewage treatment apparatus according to the present invention is not a structure in which the upper side is open, but is blocked in all directions like a chamber, but the scum flow pipe 500 from which the scum (S) is discharged is installed on the ceiling surface Because of the structure, when the inflow of sewage into the electrolytic flotation tank 100 continues and the water level in the electrolytic flotation tank 100 rises, the scum (S) flows through the scum flow pipe 500 to the scum collecting chamber 400 It is characterized by automatic discharge. That is, in the sewage treatment device according to the present invention, the scum (S) suspended on the water surface is discharged to the outside by the internal pressure of the electrolytic flotation tank 100 without a separate scum removal device, so the installation cost and maintenance cost of the scum removal device It has the advantage of reducing the cost and making it possible to miniaturize the device.

On the other hand, the gas generated from the electrolytic oxidation module 110 is collected in the scum collecting chamber 400 together with the scum (S), flows into the venturimeter 300 through the air intake pipe 310, and then the venturimeter 300 ) is supplied to the bioreactor 200 together with the treated water passing through. At this time, since the gas generated from the electrolytic oxidation module 110 has a higher oxygen concentration than air in the atmosphere, when the gas generated from the electrolytic oxidation module 110 is supplied to the bioreactor 200 , dissolved oxygen in the bioreactor 200 . It has the advantage that the concentration can be increased and the effect of purifying wastewater with oxygen can be increased.

The scum (S) suspended on the water surface of the electrolytic flotation tank 100 can be smoothly discharged through the scum flow pipe 500 as the internal pressure of the electrolytic flotation tank 100 is higher, and the sewage supply pipe 120 through the When the supplied sewage is configured to flow into the electrolytic flotation tank 100 by the head pressure, a limit occurs in increasing the internal pressure of the electrolytic flotation tank 100, and accordingly, the scum (S) cannot be smoothly discharged. may occur.

The sewage treatment apparatus according to the present invention may further include a sewage supply pump 130 that compresses the sewage supplied from the outside to a pressure of a preset size and supplies it to the sewage supply pipe 120 so as to solve this problem. can As such, when the sewage supply pump 130 is mounted on the sewage supply pipe 120, the pressure inside the electrolytic flotation tank 100 can be significantly increased, so that the scum (S) can be discharged more smoothly into the scum collecting chamber 400. There are advantages to being able to In addition, when the pressure inside the electrolytic flotation tank 100 is increased by the sewage supply pump 130, the size of the bubbles generated in the electrolysis process of the electrolytic oxidation module 110 is reduced, so that the floating speed of the bubbles is lowered and , this has the advantage of improving the efficiency of levitating the contaminants by attaching the bubbles to the contaminants, that is, the scum flotation efficiency.

On the other hand, in the sewage treatment apparatus according to the present invention, a flow pipe valve 510 for adjusting the opening degree of the scum flow pipe 500 may be added to control the amount of scum (S) discharged, and outdoor air flowing into the venturimeter 300 may be added. A suction pipe valve 320 for adjusting the opening amount of the air suction pipe 310 may be added to adjust the inflow amount.

For example, if the opening amount of the flow pipe valve 510 is decreased and the opening amount of the air intake pipe 310 is increased, the amount of outside air flowing into the venturimeter 300 increases as shown in FIG. The flow rate of treated water flowing into the bioreactor 200 through 300) increases, and the flow rate of scum (S) through the scum flow pipe 500 decreases. Therefore, the amount of scum (S) discharged to the scum collecting chamber 400 is reduced. Conversely, if the opening amount of the flow pipe valve 510 is increased and the opening amount of the air intake pipe 310 is decreased, the amount of external air flowing into the venturimeter 300 is reduced as shown in FIG. The flow rate of treated water flowing into the bioreactor 200 through will do As described above, the sewage treatment apparatus according to the present invention has the advantage of being able to freely control the amount of scum (S) discharge through the operation of the flow pipe valve 510 and the suction pipe valve 320 .

5 is a schematic diagram of a second embodiment of a sewage treatment apparatus according to the present invention.

2 to 4, when the ceiling surface of the electrolytic flotation tank 100 is formed to form a plane, the scum flow pipe 500 and adjacent to the scum (S) floating on the water surface of the electrolytic flotation tank 100 The scum S may be smoothly introduced into the scum flow pipe 500 , but the scum S at a point far away from the scum flow pipe 500 may not smoothly flow into the scum flow pipe 500 .

In the sewage treatment apparatus according to the present invention, the ceiling surface of the electrolytic flotation tank 100 is inclined so that all scum (S) floating on the water surface of the electrolytic flotation tank 100 can smoothly flow into the scum flow pipe 500 . can be formed. That is, as shown in FIG. 5, the ceiling surface of the electrolytic flotation tank 100 may be inclined in a direction in which the height increases toward the point where the scum flow tube 500 is connected (toward the center in this embodiment). have.

As such, when the ceiling surface of the electrolytic flotation tank 100 is formed to be inclined, when the water level of the electrolytic flotation tank 100 rises, all the scum (S) gathers in the middle of the ceiling surface and flows into the scum flow pipe 500, There is an advantage that all of the scum (S) in the flotation tank 100 can be smoothly discharged to the scum collecting chamber 400 .

At this time, the inclination direction of the ceiling surface of the electrolytic flotation tank 100 is not limited to the shape shown in this embodiment, and can be formed in any shape as long as the scum (S) can be smoothly guided to the scum flow pipe (500). can

On the other hand, if the amount of scum (S) generated in the electrolytic flotation tank 100 increases, it is necessary to discharge the scum (S) more quickly. ), it may be difficult to accurately determine the amount of scum (S) in the

Therefore, the sewage treatment apparatus according to the present invention may further include a pressure sensor 140 mounted on the ceiling surface of the electrolytic flotation tank 100 to sense the scum (S) pressure in the electrolytic flotation tank 100 . have. When the density of the scum (S) increases due to an increase in the amount of scum (S) generated in the electrolytic flotation tank 100, a large pressure is applied to the pressure sensor 140 installed on the ceiling surface of the electrolytic flotation tank 100, so that the operator It is possible to infer the amount of scum (S) generated by grasping the pressure value measured by the pressure sensor 140 .

At this time, the flow pipe valve 510 is operated to adjust the opening degree of the scum flow pipe 500 in proportion to the scum (S) pressure in the electrolytic flotation tank 100, the scum (S) in the electrolytic flotation tank 100 ) is generated in a large amount, the amount of opening of the scum flow tube 500 is increased, so that the scum (S) in the electrolytic flotation tank 100 can be discharged more quickly.

6 is a schematic diagram of a third embodiment of a sewage treatment apparatus according to the present invention.

When the amount of sewage supplied through the sewage supply pipe 120 increases, the pressure inside the electrolytic flotation tank 100 increases, so that the scum (S) is smoothly discharged to the scum collecting chamber 400, and the amount of scum (S) generated is large. If not, the water level in the electrolytic flotation tank 100 is gradually increased, and the treated water in the electrolytic flotation tank 100 may be discharged to the scum collecting chamber 400 through the scum flow pipe 500 .

As such, the treated water filled in the scum collecting chamber 400 is discharged and discarded together with the scum (S), so a problem of wasted water may occur. The sewage treatment apparatus according to the present invention includes a water level sensor 150 for detecting the water level in the electrolytic flotation tank 100, and the electrolytic flotation tank 100 to prevent the inflow of treated water into the scum collecting chamber 400. It may be configured to further include a venturi valve 330 that increases the opening amount of the venturi meter 300 as the water level of 100 increases. When the water level sensor and the venturi valve are additionally provided in this way, when the water level in the electrolytic flotation tank 100 is excessively raised enough to cause a risk that the treated water may flow into the scum flow pipe 500, the treatment in the electrolytic flotation tank 100 Since the water can be quickly discharged into the bioreactor 200 , there is an advantage in that the treated water can be prevented from being discharged to the scum collecting chamber 400 .

In addition, in the sewage treatment apparatus according to the present invention, the scum (S) rising above the water surface is discharged to the scum collecting chamber 400 by the levitation force. When the water level in the electrolytic flotation tank 100 is not high, the scum (S) It may not be able to drain smoothly.

Accordingly, in the sewage treatment apparatus according to the present invention, as shown in this embodiment, when the water level sensor 150 and the venturi valve 330 are additionally mounted, the water level of the electrolytic flotation tank 100 is periodically increased and decreased to cause scum. (S) It may be configured such that the discharge can occur periodically. That is, the venturi valve 300 may be set to periodically increase/decrease the opening degree of the venturi meter 300 when a predetermined time has elapsed from the start of the operation of the effluent supply and the electrolytic oxidation module 110 . As such, when the opening degree of the venturimeter 300 is periodically increased or decreased, the water level of the electrolytic flotation tank 100 is periodically raised and lowered. The scum (S) in the electrolytic flotation tank 100 is the electrolytic flotation tank 100. It can be smoothly discharged to the scum collecting chamber 400 when the water level of the rises.

At this time, since the water level sensor and the venturi valve have been commercialized in various structures in the technical field to which the present invention pertains, detailed descriptions of the internal configuration and operating principle of the water level sensor and the venturi valve will be omitted.

As mentioned above, although the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to specific embodiments, and should be interpreted by the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

S: scum 100: electrolytic flotation tank
110: electrolytic oxidation module 120: sewage supply pipe
130: sewage supply pump 140: pressure sensor
150: water level sensor 200: bioreactor
300: venturimeter 310: air intake pipe
320: suction pipe valve 330: venturi valve
400: scum collecting chamber 500: scum flow pipe
510: flow pipe valve

Claims (7)

a bioreactor in which a biotreatment process is performed;
It has a closed chamber shape, a sewage supply pipe through which sewage is introduced from the outside, a venturimeter that delivers the treated water inside to the bioreactor, and a cathode and anode are cross-arranged and installed on the bottom side of the inner space an electrolytic flotation tank having an electrolytic oxidation module;
a scum collecting chamber in which scum is collected;
a scum flow pipe configured to connect the ceiling surface of the electrolytic flotation tank and the upper side of the scum collecting chamber, and deliver the scum in the electrolytic flotation tank to the scum collecting chamber;
an air suction pipe for supplying external air to a portion where the flow path is narrowed among the venturimeters, the middle portion communicating with the scum collecting chamber;
A sewage treatment device comprising a. The method according to claim 1,
The sewage treatment apparatus further comprising: a flow pipe valve for controlling an opening degree of the scum flow pipe; and a suction pipe valve for controlling an opening degree of the air suction pipe. 3. The method according to claim 2,
It is mounted on the ceiling surface of the electrolytic flotation tank, further comprising a pressure sensor for sensing the scum pressure in the electrolytic flotation tank,
The flow pipe valve is a sewage treatment apparatus, characterized in that it is operated to adjust the opening degree of the scum flow pipe in proportion to the scum pressure in the electrolytic flotation tank. The method according to claim 1,
The sewage treatment apparatus further comprising: a water level sensor for detecting the water level of the electrolytic flotation tank; and a venturi valve for increasing or decreasing the opening degree of the venturimeter so that the water level of the electrolytic flotation tank is maintained within a preset range. 5. The method according to claim 4,
The venturi valve is set to periodically discharge the scum in the electrolytic flotation tank by periodically increasing or decreasing the opening degree of the venturi meter after a predetermined time has elapsed from the start of the supply of sewage and the operation of the electrolytic oxidation module. processing unit. The method according to claim 1,
The sewage treatment apparatus further comprising a sewage supply pump for compressing the sewage supplied from the outside to a pressure of a preset size and supplying the sewage supply pipe to the sewage supply pipe. The method according to claim 1,
The ceiling surface of the electrolytic flotation tank is a sewage treatment apparatus, characterized in that the scum flow pipe is connected to the point where the height increases in a direction inclined in the direction.

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