JPH09136096A - Purification tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make extraction operation possible after sludge being concentrated to a high concentration by a method in which a filtrate transfer pipe is installed in another tank adjacent to a sludge storage tank from the sludge storage tank to install in parallel with a filter membrane apparatus. SOLUTION: A filter membrane apparatus C1 for filtering water to be treated is installed in a sludge storage tank N2, and a filtrate transfer pipe A6 which transfers filtrate from the filter membrane apparatus C1 is installed in another tank adjacent to a sludge storage tank N2 from the sludge storage tank N2 to install in parallel with the filter membrane C1. In this way, since the sludge of the storage tank N2 is subjected to solid-liquid separation by the filter membrane apparatus C1, water can be extracted from the storage tank N2 to another water treatment tank. Besides, since solid components are remain in the storage tank N2, the sludge in the tank N2 can be concentrated to a high concentration. In this way, in the maintenance of a purification tank, the sludge in the tank N2 can be extracted in a state of a high concentration so that sludge in the purification tank can be removed enough even in a small amount of extraction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a septic tank provided with a sludge storage tank for storing sludge generated in the tank.

[0002]

2. Description of the Related Art Conventionally, in this type of septic tank, the sludge storage tank is simply provided with a space for sludge storage.

[0003]

Normally, the sludge stored in the sludge storage tank is constructed so that the increase in the amount of sludge in the tank can be suppressed by periodically pulling the sludge out of the tank. According to the conventional sludge storage tank described above, since it is configured to simply store sludge, it is difficult to make the sludge a high concentration even if it is allowed to stand and precipitate and concentrate. When it comes to pulling out, even if a certain amount of solid components are pulled out, a large amount of sludge must be pulled out, and sludge pulling out must be performed frequently.
It had the drawback of requiring a great deal of maintenance effort.

Therefore, in view of the above-mentioned drawbacks, it is an object of the present invention to provide a septic tank capable of concentrating sludge to a high concentration and then extracting it.

[0005]

A characteristic configuration of the present invention for achieving this object is a septic tank provided with a sludge storage tank, wherein the sludge storage tank is internally equipped with a filtration membrane device for filtering water to be treated. In addition, a filtered water transfer pipe for transferring filtered water that has been filtered by the filter membrane device from the sludge storage tank to another tank adjacent to the sludge storage tank is provided continuously with the filter membrane device. In the above, the filtration membrane device may be arranged above the sludge storage tank, the water level of the sludge storage tank is set higher than the water levels of the other tanks, and the treated water transfer pipe is , Provided below the water level of the sludge storage tank, an air diffuser may be provided below the filtration membrane device, and a screen for solid-liquid separation of the water to be treated supplied below the filtration membrane device is provided. It may be
The effects are as follows.

[Operation and Effect] That is, according to the above configuration,
Since the sludge in the sludge storage tank is solid-liquid separated by the filtration membrane device, water is drawn from the sludge storage tank to another water treatment tank,
Since the solid component that can be subjected to water treatment and solid-liquid separated remains in the sludge storage tank, the sludge in the sludge storage tank can be concentrated to a high concentration. Therefore, when maintaining the septic tank, the sludge in the sludge storage tank can be extracted in a high-concentration state, and the sludge in the septic tank can be sufficiently removed even with a small extraction amount. In addition, since sludge is accumulated in a high concentration state, even a small sludge storage tank can allow accumulation of sludge for a long period of time, so that the septic tank can be operated stably without much maintenance. Become,
The labor required for maintenance can be reduced, and the septic tank can be made small as a whole to facilitate the construction of the septic tank.

Further, if the filtration membrane device is arranged above the sludge storage tank, the supernatant of the sludge precipitated and concentrated in the sludge storage tank can be solid-liquid separated and the sludge can be efficiently concentrated. Can be done. Further, if the water level of the sludge storage tank is set higher than the water levels of the other tanks, and the treated water transfer pipe is provided below the water level of the sludge storage tank, it is particularly sucked into the filtration membrane device. The sludge in the sludge storage tank can be constantly concentrated and operated without providing a filtration membrane device. In this configuration, if an air diffusing pipe is provided below the filtration membrane device, even if dirt is attached to the filtration membrane device, bubbles due to the air diffusion device collide with the filtration membrane device. Since the dirt is prevented from fixing on the filtration membrane device while peeling the dirt from the filtration membrane device, the function of concentrating the water to be treated can be maintained for a long period of time. In the sludge storage tank, odor is likely to be generated, but the bubbles due to air diffusion are also useful for removing odor. Further, if a screen for solid-liquid separation is provided below the filtration membrane device, it is possible to prevent relatively large solid components from adhering to the filtration membrane device and prevent inconveniences such as clogging of the filtration membrane device. It's easy to do.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the septic tank of the present invention is divided into a cylindrical septic tank main body X by providing mirror portions X1 and X2 at both ends to form a sealed space inside and partition walls provided in the sealed space inside. Then, from the upstream side, a flow rate adjusting tank N1, a denitrification tank E1, a sludge storage tank N2, a membrane separation tank E2, and a discharge pump tank T are formed, and a manhole used for maintenance or the like is formed on the upper part of each tank. H is provided.

The flow rate adjusting tank N1 is the septic tank main body X.
By receiving the raw water of the treated water that has flowed into the septic tank from the inflow port I provided in one of the mirror portions X1 and precipitating and removing the impurities in the treated water, the anaerobic bacteria growing inside the When the first pump P1 for transferring the treated water to the denitrification tank E1 is provided in the water treatment chamber for temporarily storing the treated water while anaerobically treating the treated water, and a large amount of the treated water flows in, Even if there is no inflow of water to be treated for a long period of time, the water to be treated is constantly transferred to the denitrification tank E1 so as not to hinder the water treatment in each subsequent water treatment chamber.

The denitrification tank E1 is the flow rate adjusting tank N1.
An inflow pipe A1 for introducing the water to be treated from the flow rate adjusting tank N1 into the water treatment chamber adjacent to is connected to the first pump P1 and constitutes an inflow passage for the water to be treated. Further, the second pump P2 is internally provided, and the transfer pipe A2 is provided in the second pump P2 to transfer the water to be treated to the membrane separation tank E2. In addition, a stirring pump P3 for stirring and circulating the water to be treated in the tank is provided to mix the water to be treated in the tank and mix the water to be treated with a high BOD load with the nitrified water to be treated. In addition, it is configured to perform advanced denitrification processing.

The membrane separation tank E2 is provided with the inflow passage in a partition wall which separates the denitrification tank E1 from the denitrification tank E1, and the water to be treated which has excessively flown into the denitrification tank E1 is introduced into the denitrification tank E1. A return pipe A3 for returning the water is provided to form a return path for the water to be treated. In addition, a membrane separation device M in which a large number of flat plate-shaped filtration membrane plates are arranged in parallel in an upright state is installed, and the membrane separation device M is a filtration device that holds a large number of filtration membrane plates in alignment. A membrane plate holding frame is provided, and a leg portion for supporting the filtration membrane plate holding frame is provided at the lower portion, and air bubbles are supplied to the filtration membrane plate between the leg portions so that sludge or the like adheres too much to the membrane surface. And a diffusing device D for supplying oxygen to the water to be treated while forming a circulating flow in the membrane separation tank E2. Further, a water intake pipe M1 is connected to each of the filtration membrane plates of the membrane separation device M, and a water collection pipe M2 for joining the filtered water from the water intake pipe M1 and guiding it to the outside of the membrane separation tank E2 is connected. Yes, it is connected to the discharge pump tank T adjacent to the membrane separation tank E2 below the water surface of the membrane separation tank E2. The membrane separation tank E2 is equipped with a settling sludge transfer pipe A4 for transferring the settling sludge to the sludge storage tank N2 by an air lift action.

The sludge storage tank N2 is the denitrification tank E1.
And the membrane separation tank E2 are divided into water treatment spaces. Above the sludge storage tank N2, a transfer pipe A2 for transferring the water to be treated from the denitrification tank E1 to the membrane separation tank E2 is arranged in a horizontal posture. A screen filtration device S for solid-liquid separation is interposed above the sludge storage tank N2 of the transfer pipe A2. As shown in FIGS. 2 and 3, the screen filtering device S includes a comb-shaped screen S1 including a large number of comb teeth S1a for solid-liquid separation, and the comb teeth S1.
A roller S2 for scraping the solid matter caught on the comb-shaped screen S1 by inserting a large number of protrusions S2a between the rollers 1a.
Of the water to be treated transferred through the transfer pipe A2, a relatively large solid component is filtered by the comb-shaped screen S1, and the water to be treated that has passed through the comb teeth S1a is The solid matter transferred to the membrane separation tank E2 and caught on the comb teeth S1a is the roller S2.
It is scraped up by the above and finally dropped into the sludge storage tank N2, and the solid matter is accumulated in the sludge storage tank. The sedimentation sludge transfer pipe A4 is provided between the membrane separation tank E2 and the sludge storage tank N2, and the relatively high-concentration sedimentation sludge settling at the bottom of the membrane separation tank E2 is transferred by the sedimentation sludge transfer. Tube A4
By this, it is configured to be returned and stored in the sludge storage tank N2. Further, as shown in FIG. 1, a filtration membrane device C for filtering the water to be treated is provided above the sludge storage tank N2.
1 is installed inside, and a filtered water transfer pipe A6 for transferring filtered water filtered by the filter membrane device C1 from the sludge storage tank N2 to the denitrification tank E1 is provided and connected to the filter membrane device C1. is there. Further, the filtration membrane device C1 is covered with a casing C2 whose upper and lower ends are in an open state, and a screen C3 made of punching metal is provided at a lower opening of the casing C2 so that a coarse solid component is contained in the filtration membrane. It is configured to prevent adhesion to the device C1. An air diffuser D for supplying air bubbles to the filtration membrane device C1 below the filtration membrane device C1 in the casing C2.
1 is provided, and below the screen C3, an air diffuser D2 for supplying air bubbles to the screen C3 is provided so that an upward flow is formed in the sludge supernatant and adheres to the filtration membrane device C1 and the screen C3. While removing the dirt
The odorous component in the sludge storage tank N2 is oxidized and removed so that it can be alleviated. The water level in the sludge storage tank N2 is set to be higher than the water level in the denitrification tank E1, and a check valve A7 is attached to the filtered water transfer pipe A6.
Is provided to prevent the water to be treated in the denitrification tank E1 from flowing backward.

With such a configuration, the sludge storage tank N2
In the inside, solid components from the screen filtration device S,
Precipitated sludge and the like from the membrane separation tank E2 (hereinafter simply referred to as “sludge and the like”) and other components that may adversely affect water treatment are stored and concentrated, and the sludge storage is performed by the filtration membrane device C1. By returning the filtered water that has been solid-liquid separated from the supernatant of the sludge storage tank N2 due to the head difference between the tank N2 and the denitrification tank E1, to the denitrification tank E2, it becomes possible to further concentrate the solid component. It became possible to store it at a high concentration, and it became possible to efficiently perform the operation of pulling out sludge and the like.

The discharge pump tank T is composed of a disinfection tank Q1 and a storage tank Q2. The disinfection tank Q1 has a partition for partitioning the membrane separation tank E2 and the discharge pump tank T with a treated water receiving container. It is provided with a small hole on its wall surface,
The filtered water that has flowed into the disinfection tank Q1 is sterilized and then flows into the storage tank Q2. The storage tank Q2 is a third pump P
4 is installed inside, and after storing the treated water, the treated water can be pumped up by the discharge pump P1 and discharged from the discharge port Z to the outside of the septic tank via the discharge pipe A5. As a result, the disinfected treated water is discharged from the storage tank T almost quantitatively to the outside of the septic tank.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a vertical side view of a septic tank.

FIG. 2 is an overall perspective view of a screen filtration device.

FIG. 3 is a plan view of a main part of a screen filtration device.

[Explanation of symbols]

 A6 Treated water transfer pipe C1 Filtration membrane device C3 Screen D1 Air diffuser N2 Sludge storage tank

Front Page Continuation (72) Inventor Kazuyuki Honda, 1 Takamatsu, Kosai-cho, Koga-gun, Shiga 1 Kubota Shiga factory (72) Inventor Katsumi Hamada 1-Kuma, Koga-cho, Shiga, Kubota 1-share company Shiga Factory (72) Inventor Shinichi Furuse 1 of 2 Takamatsu, Kosai Town, Koga District, Shiga Prefecture Kubota Shiga Factory

Claims (4)

[Claims] 1. A septic tank provided with a sludge storage tank (N2), wherein the sludge storage tank (N2) is internally provided with a filtration membrane device (C1) for filtering water to be treated, and the sludge storage tank (N2). ), A filtered water transfer pipe (A6) for transferring the filtered water filtered by the filter membrane device (C1) to another tank adjacent to the sludge storage tank (N2) is provided to the filter membrane device (C1). A septic tank that is installed in series. 2. The septic tank according to claim 1, wherein the filtration membrane device (C1) is arranged above the sludge storage tank (N2). 3. The water level of the sludge storage tank (N2) is set higher than the water levels of the other tanks, and the treated water transfer pipe (A6) is set below the water level of the sludge storage tank (N2). The septic tank according to any one of claims 1 and 2, which is provided with an air diffuser (D1) below the filtration membrane device (C1). 4. The septic tank according to claim 1, further comprising a screen (C3) for solid-liquid separating the water to be treated supplied below the filtration membrane device (C1).