JPS59230694A - Fluidized aeration tank using particulate medium - Google Patents

Abstract

PURPOSE:To efficiently perform the biological oxidation of an org. substance by a microorganism, by using a particulate material such as sand as a fluidized medium while smoothly revolving and fluidizing the medium to which the microorganixm is held as much as possible in a fluidized aeration tank. CONSTITUTION:After a solid-liquid separation part is filled with water so as to reach the upper edge thereof and a predetermined amount of air is always supplied to a fluidized aeration tank 1 from the lower end of an air supply pipe 11 while air bubbles are raised through an air lift 9 to be exhausted and a revolving stream is generated in the aeration tank. A medium is discharged into a partition cylinder 8 from the upper end part of the air lift pipe 9 while carried on the rising stream generated by the air bubbles rising through the air lift pipe 9 and, before long, begins to fall by gravity to reach the bottom part of a cone part 2 through the gap between partition plates 10, 5 to repeat rotary movement and rising motion. By this mechanism, a biological membrane is formed to the surface of a particulate material such as sand being the medium and the org. components in raw water are removed by microorganism.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluidized aeration tank using granular media.

As a biological treatment method for organic wastewater, the biofilm treatment method, which has advantages such as a high BOD load and a small amount of sludge produced, is being reconsidered, and various devices are being put into production.

Conventional biofilm treatment methods include fluidized bed media methods and fixed bed media methods.

The fluidized bed media method is a method in which a medium is placed in an aeration tank and circulated in a fluidized manner by aeration to form a biofilm on the medium, and the organic components in the wastewater are removed by this microorganism.

Furthermore, the fixed bed media method is a method in which a medium is fixedly packed into an aeration tank to form a biofilm, and wastewater is treated with microorganisms.

The present invention relates to a fluidized aeration tank applied to the former fluidized bed media method, in which a granular material such as sand is used as the fluidized medium, and a medium holding as many microorganisms as possible is produced in the tank. The object of the present invention is to provide a fluidized aeration tank using a granular medium configured to smoothly swirl and flow.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

The figure explains one embodiment of the present invention, and the fluidized aeration tank of the present invention has a coin part 2 constricted at the lower end of a cylindrical part 1, and a solid part 2 whose cross-sectional area is enlarged upwards at the upper end. It has a liquid separation part 3,
The lower end of the cone portion 2 is closed, and raw water is supplied into the tank from the bottom surface of the cone portion 2 via a pipe 4.

A partition plate 5 is provided which is narrower in shape than the cone part 2 from approximately the center of the inner circumferential surface of the cone part 2 toward the bottom thereof, and is provided between the bottom of the cone part 2 and the lower end of the partition plate 5. A slit 6 is formed as a slight gap.

Further, inside the solid-liquid separation section 3, a partition cylinder 8 having the same diameter as the aeration tank cylinder section 1 is provided, and its lower edge and the solid-liquid separation section 3
A gap is provided between the inner peripheral surface of the pipe and the inner circumferential surface of the pipe to allow waste water to flow freely.

On the other hand, an air lift pipe 9 is arranged on the axis of the cylindrical part 1 of the aeration tank. The air lift pipe 9 is arranged such that its lower end is at an optimal distance above the lower edge of the partition plate 5,
Further, a partition plate 10 that opens downward is provided on the outer peripheral surface of the lower part of the air lift pipe 9. In this case, the lower edge of the partition plate 10 does not come into contact with the inner peripheral surface of the opposing partition plate 5, and a gap 7 is provided through which the medium can freely pass. An air supply pipe 11 is inserted on the axis of the near lift pipe 1 to the pipe 9, the lower end of which is opened with a porous hole, and is located slightly above the lower end of the air lift pipe 9.

In the figure, what is indicated by a broken line 12 is a pipe for circulating water, one end of which is inserted into the water surface of the solid-liquid separator 3 shallowly (inserted in multiple locations), and its lower end discharge side is near the bottom surface of the cone part 2. The openings are tangential to the cone portion 2 at a plurality of locations.

13 is a pump for circulating treated water.

By the way, a predetermined amount of granular material such as sand is put into the aeration pile as a fluidizing medium.

Next, the operation of this embodiment configured as above will be explained.

First, the solid-liquid separation section 3 is filled with water up to the upper edge, and then a predetermined amount of air is constantly supplied from the lower end of the air supply pipe 11, and the air bubbles rise inside the air lift pipe 9 and are discharged. Create a swirling flow in the aeration tank.

On the other hand, the pump 13 is operated to circulate the treated water from the water surface of the solid-liquid separation section 3 to the tangential direction of the bottom surface of the cone section 2 via the pipe 12. Particulate matter such as sand deposited in the cone portion 2 is slowly rotated and moved to the center of the tank by this circulating water, and is guided into the air lift pipe 9 together with the circulating water rising through the slit 6.

The air bubbles are then discharged from the upper end of the air lift pipe 9 into the partition WJ 8 on the upward flow generated by the bubbles rising inside the air lift pipe 9, and eventually begin to settle due to gravity, causing the separation between the partition plate 10 and the partition plate 5. It reaches the bottom of the cone part 2 through the gap between them, and repeats the rotational movement and upward movement described above.

During this circulation and distillation for a predetermined period of time, a biofilm is formed on the surface of the granular medium such as sand, and the organic components in the raw water are removed by the microorganisms.

The raw water that is sent from the raw water feed pipe 4 to the aeration tank and stagnated for a predetermined time eventually overflows from the upper end of the solid-liquid separation section 3 and is led to the settling tank (not shown) by the treated water pipe 13, where the sludge is removed. It is separated and becomes treated water.

As is clear from the above description, according to the present invention, the treated water can be circulated tangentially to the bottom of the tank, and the medium can be slowly rotated to the center of the tank bottom, making it easy to air lift. . In that case, the medium deposited by the installation of the partition plates 10 and 5 gradually moves downward through the gap 7, so that the effect of the circulating water can be made effective.

In other words, if the partition plates 10 and 5 are not installed and the circulating water is not supplied, if the amount of medium input increases, it will remain deposited in the cone part 2, and even if the air m is increased, the near rift 1- It will no longer be done. However, according to this embodiment, the medium deposited in the cone portion 2 moves smoothly and is smoothly airlifted, so that the amount of medium input can be increased.

Since this embodiment is configured as described above, it is possible to hold many microorganisms in the tank, and also to efficiently supply oxygen to the microorganisms, so that the microorganisms can efficiently perform biological oxidation of organic matter. , good quality treated water can be obtained.

[Brief explanation of drawings]

The figure is a schematic diagram illustrating an embodiment of the present invention. Figure 1 is a vertical cross-sectional view of the overall structure, Figure 2 is a cross-sectional view of Figure 1.
It is a diagram seen from the direction. 1 is the aeration tank cylindrical part, 2 is the cone part, 3 is the solid-liquid separation part, 4
is a raw water supply pipe, 5 and 10 are partition plates, 6 is a slit, 7 is a gap, 8 is a partition cylinder, 9 is an air lift pipe, 11 is an air supply pipe, 12 is a circulating water pipe, and 13 is a treated water pipe. . Patent applicant: Ube Industries, Ltd.

Claims (1)

[Claims] An aeration tank that is formed in a cylindrical shape, has a cone portion constricted downward at the lower end, and a solid-liquid separation section that opens upward at the upper end, has a concentric shape in the center of the aeration tank. an air lift pipe arranged in the air lift pipe, an air supply pipe arranged concentrically within the air lift pipe, and a funnel-shaped air supply pipe arranged inside the cone part with its lower edge facing close to the bottom surface of the cone part. A partition plate is provided at the lower part of the near rift 1 to the pipe, and a partition plate that widens toward the end with its lower end facing the vicinity of the partition plate is provided, raw water is supplied from the bottom of the cone part, and the solid-liquid A fluidized aeration tank using a granular medium, characterized in that treated water is supplied from the water surface of the separation section via piping tangentially from multiple locations around the lower part of the cone section and circulated.