JPH09103791A - Septic tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the surface of a membrane in liq. from being clogged with a sewage substance by cleaning off the substance depositing on the membrane to be used in purifying sewage with the cavitation generated by an ultrasonic wave. SOLUTION: An ultrasonic wave generator 30 is provided below a diffuser pipe 18. Accordingly, the sewage substance depositing on the surface of a membrane in a membrane cartridge 16 is sufficiently cleaned off by the synergism of the water current caused by the aeration and agitation of the air diffused from the pipe 18, ascending force of bubbles and bursting of the cavitation resulting from the oscillation from the ultrasonic wave generator 30. Consequently, the membrane is not clogged, and the lowering of the sewage treating capacity is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a septic tank for treating gray water and human waste by using a submerged membrane, and an industrial septic tank for treating factory process wastewater.

[0002]

2. Description of the Related Art Conventionally, a septic tank for treating sewage using a submerged membrane has been widely used. The submerged membrane used in this type of septic tank has micropores that prevent the permeation of relatively large molecules in wastewater on the membrane surface, while allowing the permeation of relatively small molecules of water. These submerged membranes are installed, for example, in the upper part of the aeration pipe for aeration, and the aeration and agitation water flow and bubbles come into contact with the surface of the membrane and ascend while vibrating the membrane surface to adhere to this membrane surface. The sewage substance is washed to prevent clogging due to the sewage substance.

[0003]

The above-mentioned submerged film body is generally installed on the upper part of the aeration pipe for aeration so as not to cause clogging by the cleaning means by the water flow and bubbles of aeration stirring, but it is not always sufficient. Since it cannot be washed, it may cause clogging and reduce the processing capacity. Therefore, it is an object of the present invention to provide a septic tank that reliably prevents the membrane surface of the submerged membrane from being clogged with a wastewater substance.

[0004]

A first means for solving the above problems is a cavitation generated by ultrasonic oscillation of a wastewater substance attached to a submerged membrane used in the process of purifying wastewater. Is to configure the septic tank so that it is cleaned.

According to the septic tank having the above-mentioned structure, the sewage substance adhering to the film surface of the submerged membrane can be cleaned by the cavitation caused by the oscillation of ultrasonic waves, and the clogging of the submerged membrane can be prevented. can do.

A second means for solving the problem is to allow water molecules of sewage to permeate into the inside and release the water molecules to the outside as treated water, while exceeding a predetermined size larger than the water molecules. Adhered to the submerged membrane body by the cavitation generated by the water flow and bubble rising force of aeration and stirring by aeration from the bottom of the submerged membrane body configured so as not to pass the filthy substance of the molecule, and the cavitation generated by ultrasonic oscillation Clear sewage substances
To configure the septic tank.

According to the septic tank having the above structure, the submerged membrane is synergized by the water flow of aeration and agitation due to air diffusion from below the submerged membrane and the ascending force of the bubbles, and the cleaning force by cavitation by ultrasonic oscillation. Sewage substances on the body are washed away.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a process diagram showing a treatment process of a combined septic tank for treating wastewater such as toilet drainage, laundry drainage, cooking drainage, bathroom drainage and the like. Since each tank described below is a general one, the operation of each tank will not be described. Wastewater such as toilet drainage, laundry drainage, cooking drainage, bathroom drainage, etc. that has flowed in from the outside passes through the coarse screen 1 and is stored in the aeration sand settling tank 2 and aerated. The sewage that has been set aside is aerated and settling tank 2 to raw water pump tank 3
After being stored in the flow control tank 5, the water is temporarily stored and then sent to the flow rate adjusting tank 5 by the pump 4.

The dirty water flowing into the flow rate adjusting tank 5 is aerated by diffusing the air sent from the blower 6 through the diffusing pipe 7. This aerated sewage is sucked by the pump 8,
In the process of passing through the fine screen 9, the relatively large particles in the wastewater are captured by the fine screen 9.
The wastewater that has passed through the fine screen 9 is denitrified tank 1
0, and nitrogen components are removed. Then, the wastewater from which the nitrogen component has been removed is sent to the nitrification tank 12 by the pump 11. A pipe 13 is provided between the denitrification tank 10 and the nitrification tank 12.
Are connected so that the wastewater in the nitrification tank 12 returns to the denitrification tank 10.

The nitrification tank 12 is equipped with a membrane unit 14 as shown in FIG. This membrane unit 1
Reference numeral 4 is composed of a plurality of film cartridges 16 which are detachably mounted in the outer frame plate 15. The membrane unit 14 is attached to the upper part of an air diffuser 18 which diffuses the air sent from the blower 17, as shown in FIG. The sewage sent from the denitrification tank 10 to the nitrification tank 12 rises while contacting the membrane surface of each membrane cartridge 16 together with the aeration and agitation water flow and bubbles due to the diffusion from the diffusion pipe 18.

When the wastewater in the nitrification tank 12 rises while coming into contact with the membrane surface of each membrane cartridge 16, while the water molecules pass through the fine pores of the membrane body, floating substances, nitrifying bacteria,
Since denitrifying bacteria have a large molecular size, they cannot pass through the micropores of the membrane. While these substances having a large molecular size are stored in a sludge storage tank (not shown), the water that has penetrated into the inside of each membrane cartridge 16 through the fine pores of the membrane of each membrane cartridge 16 is infiltrated. Is sent to the disinfection tank 21 through the pipe 20 connected to the suction pump 19. The treated water sent to the disinfection tank 21 is used as the disinfection tank 2
After being sterilized in 1, the water is stored in the treated water tank 22 and discharged to the outside by the pump 23.

In FIG. 3, when the sewage rises while coming into contact with the membrane surface of each membrane cartridge 16, the water molecule A permeates through the fine pores of the membrane bodies 16A and 16B, while floating substances and , A nitrifying bacterium, a denitrifying bacterium, and the like have a large molecular size, and a wastewater substance B is treated so as not to pass through the fine pores of the membrane bodies 16A and 16B. The cavitation by the ultrasonic oscillation of the container 30 is shown. As shown in FIG. 3, each film cartridge 16 is provided with a support plate 16C between the film bodies 16A and 16B, and the molecules of water which have permeated through the micropores of the film bodies 16A and 16B are supported by the support plate 16C. And the film body 16A and the gap between the support plate 16C and the film body 16B. The water that has entered this gap passes through the pipe 20 and is sent to the disinfection tank 21.

In the septic tank constructed as described above,
The above-mentioned floating substances and substances having a large molecular size such as nitrifying bacteria and denitrifying bacteria are likely to adhere to the film surface of each film cartridge 16 of the film unit 14. Therefore, the water flow of aeration and agitation due to air diffusion from the air diffuser 18 and the ascending force of the bubbles, and as shown in FIG. Sound wave generator 3
An ultrasonic wave is oscillated from 0, and the sewage substance adhering to the film surface of each film cartridge 16 is sufficiently cleaned by the synergistic effect of the cavitation rupture phenomenon due to the ultrasonic wave oscillation.

FIG. 4 is a plan view of the ultrasonic wave generator 30.
FIG. 5 is a partially cutaway front view thereof. 4 and 5, an ultrasonic transducer 31 is attached to each hole 30A formed in the upper surface of the ultrasonic generator 30. Then, the cable connected to each ultrasonic transducer 31 is inserted from the elbow 32. The ultrasonic wave generator 30 is watertight so that water does not enter the inside. Therefore, the ultrasonic wave generator 30 can be immersed in a liquid as shown in FIG.

In the above embodiment, the ultrasonic generator 30 is targeted for the membrane unit 14 disposed in the nitrification tank 12.
Although an example in which the above is provided, an ultrasonic generator is used not only in the membrane unit 14 but also in a place where a semipermeable membrane in liquid is used, so that the wastewater substance attached to the membrane surface can be removed. Can be trained. Further, in the above embodiment, an example of the combined septic tank is shown, but not limited to the combined septic tank, a septic tank that is normally used, an industrial septic tank, or a permeable membrane separation method is also included in the scope of this embodiment. .

[0016]

As described above, according to the first aspect of the present invention, the sewage component adhered to the submerged membrane used in the process of treating gray water and human waste is cleared by cavitation generated by ultrasonic waves. Therefore, it is possible to prevent clogging of the membrane body and prevent deterioration of sewage treatment ability.

Further, according to the second aspect of the present invention, the sewage component adhered to the submerged membrane used in the process of treating gray water and human waste is aerated by aeration from below the submerged membrane. Since cleaning can be performed by the synergistic effect of the ascending force of air bubbles and bubbles and the cleaning force of cavitation due to ultrasonic oscillation, it is possible to prevent clogging of the membrane and reduce the wastewater treatment ability. It has the effect of preventing.

[Brief description of the drawings]

FIG. 1 is a process diagram showing an overall processing process of a septic tank.

FIG. 2 is a perspective view showing an arrangement of ultrasonic generators with respect to a membrane unit.

FIG. 3 is an explanatory view of the action of a film cartridge.

FIG. 4 is a plan view of an ultrasonic wave generator.

FIG. 5 is a front view of an ultrasonic wave generator.

[Explanation of symbols]

 2 Aeration sedimentation tank 3 Raw water pump tank 5 Flow rate adjustment tank 10 Denitrification tank 12 Nitrification tank 14 Membrane unit 16 Membrane cartridge 19 Suction pump 21 Disinfection tank 22 Treatment water tank 30 Ultrasonic generator 31 Ultrasonic transducer

Claims (2)

[Claims] 1. A septic tank characterized by cleaning sewage substances adhering to a submerged membrane used in the step of purifying sewage with cavitation generated by ultrasonic oscillation. 2. A liquid configured to allow water molecules of sewage water to permeate inside and release the water molecules to the outside as treated water, while preventing permeation of a waste water substance having a molecule larger than a predetermined size larger than the water molecule. It is characterized by cleaning the sewage substance adhering to the submerged membrane by the water flow of aeration and stirring by aeration from below the membrane, the rising force of the bubbles, and the cavitation generated by ultrasonic oscillation. Septic tank.