JP2000325972A - Septic tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a septic tank hard to exert adverse effect on water treatment environment even if receiving a large amt. of water to be treated and capable of effectively utilizing even water to be subjected to membrane permeation treatment. SOLUTION: A septic tank is provided with a filter tank E for filtering water to be treated, an upstream tank N1 for storing water to be treated supplied to the filter tank E to pretreat the same biologically, a return mechanism A1 for returning the solid component filtered in the filter tank E to the upstream tank N1, a receiving part W1 for receiving water to be treated flowing in the upstream tank N1 and water to be treated returned through the return mechanism A1, a flooding mechanism W for supplying the water to be treated bringing the water level in the upstream tank N1 to a predetermined water level HWL or more to the filter tank E from the receiving part W1 without passing the same through the upstream tank N1 and a solid-liquid separation mechanism S for subjecting the water to be treated flowing in the flooding mechanism W from the receiving part W1 to solid-liquid separation treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a treated water filtration tank for filtering treated water while subjecting it to aerobic treatment. The present invention relates to a purification tank provided with an upstream tank for processing, and provided with a return mechanism for returning the solid component filtered in the water filtration tank to the upstream tank.

[0002]

2. Description of the Related Art Conventionally, as this type of septic tank, the water to be treated that has flowed into the septic tank is received as it is in the upstream tank, and the whole amount is subjected to biological treatment in advance through the upstream tank. To be transferred to the treated water filtration tank.

[0003]

However, the water to be treated that flows into the septic tank is not necessarily to be biologically treated in advance in the upstream tank, and the water to be treated with a low load such as bath drainage is not always required. Like water (hereinafter referred to as low-load water to be treated), it merely serves to squeeze the volume in the septic tank and may delay the treatment of the water in the septic tank. . Here, when the inflow of the to-be-processed water is continuous, the water level in the tank may rise too much and exceed the processing capacity of the to-be-treated water filtration tank. In addition, when such a large amount of water to be treated is received, the water to be treated in the upstream tank becomes oxygen-enriched, and is likely to adversely affect preliminary biological treatment. In addition, the water to be treated that has flowed in such a large amount may wash out the settled sludge in the upstream tank and flow into the water to be treated filtration tank, which may adversely affect the water to be treated filtration tank. is there.

Accordingly, it is an object of the present invention to provide a septic tank which does not adversely affect the water treatment environment even if a large amount of water to be treated is received.

[0005]

In order to achieve the above object, a characteristic structure of a septic tank according to the present invention comprises a to-be-treated water filtration tank for filtering the to-be-treated water while performing aerobic treatment. An upstream tank for storing the water to be treated supplied to the biological treatment in advance is provided, and a return mechanism for returning the solid component filtered in the water to be treated filtration tank to the upstream tank is provided. A treated water receiving portion is provided for receiving the treated water flowing into the side tank and the treated water returned through the return mechanism, and the treated water for raising the upstream tank to a predetermined water level or more is provided inside the upstream tank. An overflow mechanism for supplying the treated water filtration tank from the treated water receiver to the treated water filtration tank without passing through, and solid-liquid separation of the treated water flowing into the overflow mechanism from the treated water receiver. The point is that a separation mechanism is provided. In addition, the treated water receiving portion is formed in a long cylindrical shape for guiding the treated water downward, and the treated water flowing from the treated water receiving portion to the overflow mechanism is passed therethrough for solid-liquid separation. It is preferable that a solid-liquid separation mechanism is provided to form a solid-liquid separation mechanism.

[Operation and Effect] That is, there is provided a treated water filtration tank for filtering the treated water, and an upstream tank for storing the treated water supplied to the treated water filtration tank and performing biological treatment in advance. If a return mechanism for returning the solid component filtered by the water filtration tank to the upstream tank is provided,
The water to be treated that has flowed into the septic tank is biologically treated in the upstream tank, and the treated water with a reduced load can be filtered and discharged out of the septic tank, and the water to be treated can be highly purified. I can do it. However, among the treated water flowing into the upstream tank, the high-load human wastewater and the like cannot be discharged to the outside of the tank unless the load is reduced in the upstream tank. Low drainage (hereinafter referred to as low-load drainage)
In the case where there is no problem in the aerobic treatment without passing through the upstream tank, such drainage causes a problem instead of passing through the upstream tank. Therefore, the low-load drainage water for raising the upstream tank to a predetermined water level or higher is subjected to aerobic treatment from the treated water receiving portion, a scumba, or a full (hereinafter simply referred to as a treated water receiving portion) via the overflow mechanism. With the above-described configuration in which post-filtration (aerobic filtration) is performed and discharged, only low-load drainage that easily raises the water level in the upstream tank is preferentially transferred from the overflow mechanism to the treated water filtration tank. It is possible to do. Therefore, the above problem can be simply and effectively solved.

Here, since the upstream tank is assumed to receive the water to be treated flowing into the purification tank as it is, scum may float in the tank. Therefore, it is conceivable that the low-load drainage flows into the upstream tank in which the scum is floating and pushes the scum away. Therefore, if a solid-liquid separation mechanism for solid-liquid separation of the water to be treated flowing into the overflow mechanism from the treated water receiving portion is provided, even when the low-load wastewater flows into the overflow mechanism, The low-load wastewater can be separated into a solid and a liquid and transferred to the treated water filtration tank, so that an increase in load on the treated water filtration tank can be suppressed more reliably.

The treated water receiving portion is formed in a long cylindrical shape for guiding the treated water downward, and the treated water passing from the treated water receiving portion to the overflow mechanism is passed therethrough. If a solid-liquid separator is provided by providing a solid-liquid separator for solid-liquid separation, the scum floating on the upper portion of the upstream tank is prevented from flowing into the water receiving portion by horizontal movement. Since it is possible to prevent the scum from flowing into the to-be-treated water receiving portion, it is possible to maintain a state in which the scum is difficult to flow, and when the low-load drainage flows into the to-be-treated water receiving portion, the overflow mechanism is provided. Because the functioning water level must be higher than the steady water level, the water flows into the overflow mechanism while pushing down the water to be treated in the water to be treated receiving portion downward. Therefore, even if there is scum in the treated water receiving portion, it is difficult for the scum to flow into the overflow mechanism. Further, when there is an inflow of the to-be-processed water into the overflow mechanism, a solid-liquid separator is provided for passing the to-be-processed water flowing from the to-be-processed water receiving portion to the overflow mechanism and performing solid-liquid separation. If so, even if the low-load drainage tries to flow into the overflow mechanism with scum taken in,
The scum is removed by solid-liquid separation, so that only the liquid component flows into the overflow mechanism, and it becomes even more difficult for solids to flow into the overflow mechanism.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The purification tank of the present invention includes an anaerobic treatment tank N, an aerobic treatment tank E, a treatment water tank T1, and the like from the upstream side. The anaerobic treatment tank N includes a sedimentation separation tank N1 and an anaerobic filter bed tank N2.
And the aerobic treatment tank E comprises a carrier fluidization tank E1 and a filtration tank E2. Raw water to be treated flows into the sedimentation separation tank N1 from the raw water inflow section I, and is decomposed while being transferred downstream in the order of the anaerobic filter bed tank N2, the carrier fluidization tank E1, the filtration tank E2, and the treatment water tank T1. , The treated water tank T1
After passing through the disinfecting tank Q provided above, the water is discharged from the discharge port Z to the outside of the tank. Here, the aerobic treatment tank E functions as a treated water filtration tank as a whole, and the anaerobic treatment tank N (particularly, the sedimentation separation tank N1) includes the carrier fluidization tank E1.
And acts as an upstream tank for the aerobic treatment tank E composed of the filtration tank E2.

[0010] The sedimentation separation tank N1 is configured to be able to store the raw water flowing into the to-be-processed water, and to grow anaerobic microorganisms therein. The raw water to be treated flowing into the sedimentation separation tank N1 is stored in the sedimentation separation tank N1, is anaerobically decomposed, and mainly coarse organic matter is subdivided into the lower part of the sedimentation separation tank N1. From the anaerobic filter bed tank N2. Solids such as sludge that are not easily decomposed are stored as sediment in the lower part of the sedimentation separation tank N1 or as scum in the upper part of the sedimentation separation tank N1. Further, the water to be treated flowing from the raw water inflow section is:
It is configured to be received by the water-to-be-treated receiving portion W1 composed of a cylindrical wall formed in a cylindrical shape with a downward depression, move downward in the water-to-be-treated receiving portion W1, and reach the inside of the sedimentation separation tank N1. Further, when the water level of the sedimentation separation tank N1 rises to a predetermined water level HWL, the water can flow out of the treated water receiving portion W from an overflow port W2 provided in the cylindrical wall of the treated water receiving portion W1. It is configured in. The overflow W2
Is provided with an overflow gutter W3 provided in a horizontal position over the carrier fluidizing tank E1 and the sedimentation separation vessel N1, and the water to be treated flowing out from the overflow port W2 is supplied to the carrier fluidizing vessel E1. The overflow mechanism W is configured so as to be able to be guided to E1. In addition, a grid-like or comb-like solid-liquid separator W4 is provided in front of the overflow mechanism W, and a solid-liquid separation mechanism S is configured together with the cylindrical wall.

The anaerobic filter bed tank N2 is provided with an anaerobic filter bed F, and anaerobic microorganisms are fixedly maintained on the anaerobic filter bed F and grown. The anaerobic filter bed tank N
The water to be treated that has flowed into 2 is further subjected to anaerobic treatment, decomposed to a state with almost no solid matter, and then sent to the carrier fluidization tank E1 by overflow. The anaerobic filter bed tank N
And between the carrier fluidization tank E1 and the overflow section 1 so that the water to be treated can be naturally advected.
The overflow portion 1 is provided with a comb-shaped portion 2 so as to be able to move to the water to be treated and to prevent the carrier and the sludge in the carrier flowing tank E1 from flowing back.

The carrier fluidizing tank E1 holds and holds a carrier C1 which is formed so as to be able to flow together with the water to be treated in a state in which microorganisms are supported, and has an air diffuser D1 for flowing the carrier C1 by supplying bubbles. An air diffuser is provided and provided inside, and the carrier C1 is caused to flow in the carrier flow tank E1 by supplying air bubbles from the air diffuser. With such a configuration, the water to be treated flowing into the carrier fluidization tank E1 is purified by aerobic decomposition by aerobic microorganisms. The water to be treated that has undergone such treatment is transferred to the filtration tank E2 through the transfer wall 3 provided on the first partition K1 that partitions the carrier flow tank E1 and the adjacent filtration tank E2. The advection wall portion 3 is formed in a lattice shape or a comb blade shape, and is configured to prevent the advection of the carrier C1, but allow the advection of sludge and water to be treated.

The filter tank E2 is formed by filling a carrier C2 having a specific gravity higher than that of water at a high density to a predetermined height. In addition, at a position lower than the predetermined height of the second partition wall K2 separating the filtration tank E2 and the treatment water tank T1 provided adjacent to the filtration tank E2, a filtration wall portion for allowing the water to be treated to flow freely. 4 is formed. As a result, the water to be treated including the sludge flowing to the filtration tank E2 is transferred to the carrier C.
2 is filtered through the deposited filtration layer B, and contains almost no solid content.
Advected to 1. In addition, the second partition K2 is connected to the side wall of the septic tank at the upper end, and the treated water tank T in plan view.
1 is disposed so as to be hidden below the filtration tank E2. The filter wall portion 4 is formed in a lattice shape, and is configured to prevent the flow of the carrier C2 but allow the flow of sludge and water to be treated. Further, a diffusion tube D2 as a stirring device for diffusing the carrier C2 and stirring the inside of the filtration tank is provided below the deposited filtration layer B, so that the load flows into the purification tank at night or the like. In a time zone where there is less air, air is diffused from the air diffuser D2 to regenerate the carrier. Further, in the diffuser tube D2, air is diffused toward the advection wall portion 3, and bubbles due to the aeration pass through the advection wall portion 3 and along the advection wall portion 3 on the carrier flow tank E1 side. The advection wall diffuser Da that is configured to be lifted, and similarly diffuses toward the filter wall, and bubbles generated by the diffuser pass through the filter wall 4 and are disposed on the treated water tank T1 side. A configuration is provided in which a filter wall diffuser Db configured to be raised along the filter wall 4 is provided, and the advection wall 3 and the filter wall 4 are washed to prevent clogging and the like. is there.

The advection wall 3 and the filtration wall 4
Is provided at a position lower than a predetermined height, which is the height of the upper end of the pile of the sedimentary filtration layer B, so that the to-be-treated water always passes through the sedimentary filtration layer B after a predetermined distance. Any structure may be used as long as it allows the advection of water and filters the water to be treated in the sediment filtration layer B. The carrier C1 has a specific gravity of about 0.98, and the carrier C2 has a specific gravity of about 1.0.
08, and generally has a specific gravity of 0.9-1.
It is preferable to form about two.

Further, below the filtration tank E2, an air lift pump A for transferring the water to be treated to the sedimentation separation tank N1 is provided, and the sludge generated by the water treatment is treated together with the water to be treated in the sedimentation separation tank N1. And a return mechanism for transferring the sludge generated by the regeneration of the carrier C2 from the inside of the filtration tank E2 to the sedimentation separation tank N1 together with the water to be treated. Here, the to-be-processed water from the air lift pump is configured to be guided to the to-be-processed water receiving portion W1 by the return pipe A1 laid across the sedimentation separation tank N1 from the filtration tank E2. Since the treated water receiving portion W1 is provided with the solid-liquid separator W4, the solid component contained in the returned treated water can be prevented from directly flowing into the overflow mechanism W. Is done.

The carrier fluidizing tank E1 and the filtering tank E2
The carrier holding member 10 for preventing the carrier C1 in the tank from flowing out even if a large amount of water to be treated flows into the septic tank slightly below the steady water level of the carrier C1, It is composed of mesh materials 11, 11 finer than C2, and is adhered and fixed to the peripheral wall or partition wall of the septic tank. The carrier holding member 10 has an opening 12 in a part thereof.
And an opening / closing mechanism is formed by opening / closing the opening as an outflow preventing member 13 with the opening / closing lid member 13a. As a result, even if air is diffused in the carrier fluidizing tank E1 and the filtering vessel E2 to form convection of the water to be treated, the flow is formed so as to flow smoothly without being hindered by the carrier holding member 10. You. In the case where the carriers C1 and C2 are filled in the carrier fluidizing tank E1 and the filtering vessel E2 or the carriers C1 and C2 are exchanged, after the water to be treated is drawn down to lower the water level, the opening 12 Is used as a carrier charging section, and the carrier can be easily charged and discharged, so that the maintenance can be easily performed.

Further, the carrier holding member 10 is provided with a diffuser tube insertion hole 14 for allowing the diffuser tube D1 to be inserted and removed, and the air supply tube D1a connected to the diffuser tube D1 has the above-mentioned structure. In a state in which the diffuser tube D1 is fixed in the carrier flow tank E1, a flow-out preventing member 15 for covering the diffuser tube insertion hole 14 is integrally connected to form a blocking mechanism for preventing the carrier from flowing out. is there. In addition, the air supply pipes for the diffuser pipe D1 and the air lift pump A are arranged in the space above the filtration tank, and the piping above the carrier flow tank E1 is minimized. Thereby, even when it is necessary to take out the air diffuser D1 out of the septic tank, for example, for maintenance of the air diffuser D1, the air diffuser D1 can be easily inserted and removed through the air diffuser insertion hole 14, The carrier holding member 1
Work can be performed with almost no decomposition of 0 or the like.

The treated water tank T1 allows only the clean supernatant portion that has passed through the filtration tank E2 to be discharged to the outside, flows into the disinfecting tank Q provided above the sedimentation tank T2, and contacts the solid disinfectant Q1. After being disinfected, it is discharged outside the tank.

[Alternative Embodiment] In the above embodiment, an example in which a septic tank is mainly formed in three compartments has been exemplified. However, in other various types of known septic tanks, the overflow mechanism W, solid-liquid The separation mechanism S can be adopted and applied. Also,
In the anaerobic treatment tank, in addition to the sedimentation separation tank and the anaerobic filter bed tank,
Various treatment tanks for anaerobic treatment of the water to be treated, such as a preliminary filtration tank, or a combination thereof can be employed. Further, as the aerobic treatment tank, a tank having a different form such as a biological filtration tank may be employed.

[Brief description of the drawings]

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

FIG. 2 is a vertical perspective view of a carrier fluidizing tank of a septic tank.

FIG. 3 is a vertical perspective view of a treated water receiving portion.

[Explanation of symbols]

 E2 Treated water filtration tank N1 Upstream tank A Return mechanism W1 Treated water receiver HWL Predetermined water level W Overflow mechanism S Solid-liquid separation mechanism

Claims (2)

[Claims] 1. A treatment water filtration tank for filtering treatment water while subjecting the treatment water to aerobic treatment, comprising an treatment tank for storing treatment water supplied to the treatment water filtration tank and performing biological treatment in advance. A purifying tank provided with a return mechanism for returning the solid component filtered by the to-be-treated water filtration tank to the upstream-side tank, through the to-be-treated water flowing into the upstream-side tank and the return mechanism. A treated water receiving portion for receiving the treated water to be returned to the upstream tank, and the treated water receiving the treated water from the treated water receiving section without passing through the inside of the upstream tank without raising the upstream tank to a predetermined water level or higher. A purification tank provided with an overflow mechanism for supplying to a water filtration tank, and a solid-liquid separation mechanism for solid-liquid separation of water to be treated flowing into the overflow mechanism from the treated water receiving portion. 2. The treatment water receiving portion is formed in a long cylindrical shape for guiding the treatment water downward, and the treatment water flowing from the treatment water receiving portion to the overflow mechanism is passed therethrough. A septic tank provided with a solid-liquid separator for solid-liquid separation to constitute a solid-liquid separation mechanism.