JP2000167576A - Septic tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a septic tank capable of keeping treatment capacity even if a large amt. of treated water flows in temporarily. SOLUTION: In septic tanks 10a, 10b wherein an inclusion removing tank 11 having a treated water inflow port and removing inclusions by filtering, a denitrification tank 12 and a nitrification tank 13 are demarcated by partition walls 15, 16 the upper ends of which are set to the highest water level or more, a membrane separator for performing the solid-liquid separation of treated water and a disinfection tank 17 are arranged in the nitrification tank 13 and treated water transmitted through the membranes of the membrane separator 14 is pumped up by a pump 20 to be charged in the disinfection tank 17 and an inclusion removing tank 11 is connected to the disinfection tank 17 by a discharge pipe 18 arranged outside and the pipe bottom of the discharge pipe 18 connected to the inclusion removing tank 11 is arranged to the planned highest water level of the inclusion removing tank 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a septic tank.

[0002]

2. Description of the Related Art Heretofore, when the treated water has flowed into a septic tank in an amount larger than a designed amount, the treated water overflowing the impurity removing tank sometimes overflows to a nitrification tank containing a membrane separation device. . As described above, when a large amount of treated water temporarily flows into the nitrification tank, the nitrification tank that has been processing by controlling the amount of activated sludge cannot be processed. Therefore, it is necessary to stabilize the processing capacity of the nitrification tank by providing a discharge pipe that allows the treated water to overflow from the contaminant removal tank and flow directly to the disinfection tank. At this time, if the discharge pipe is passed through the tank body of the septic tank, it must penetrate the partition that divides the inside of the tank, and a troublesome treatment such as sealing of the partition is required.

[0003]

As described above, there has been a problem that when a large amount of treated water temporarily flows into the nitrification tank, the nitrification tank cannot treat the amount of activated sludge.

[0004] The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a septic tank capable of maintaining the treatment capacity even when a large amount of treated water flows in temporarily. It is.

[0005]

According to a first aspect of the present invention, there is provided a septic tank according to the present invention, which is provided with an inlet through which treated water flows, and a contaminant removing tank for filtering and removing contaminants, a denitrification tank, and a nitrification tank. The tank and the septic tank are each separated by a partition wall whose upper end is higher than the highest water level.The transfer of the treated water between the impurity removal tank and the denitrification tank is performed by an air lift pump, and the denitrification tank and the nitrification tank are The treated water is transferred from the aeration port provided between the denitrification tank and the nitrification tank, the circulating flow from the nitrification tank to the denitrification tank is performed by an air lift pump, and the treated water is separated into solid and liquid in the nitrification tank. The treatment water that has passed through the membrane of the membrane separation device is pumped to the disinfection tank by a pump, and the contaminant removal tank and the disinfection tank are connected by a discharge pipe that is piped outside. , The bottom of the discharge pipe in contact with the impurity removal tank,
It is installed at the highest design water level of the impurity removal tank.

According to a second aspect of the present invention, there is provided a septic tank, wherein the disinfecting tank is provided outside the nitrification tank.

[0007]

According to the first aspect of the present invention, there is provided a septic tank in which the impurity removing tank and the disinfecting tank are connected by a discharge pipe which is externally provided, and the bottom of the discharge pipe in contact with the impurity removing tank is provided with an impurity removing tank. Since the tank is installed at the design maximum water level, when the treated water exceeds the designed amount into the foreign matter removal tank, the overflowed treated water is directly transferred to the disinfection tank by the discharge pipe to reduce the treatment capacity of the septic tank. I can respond without. In addition, since the discharge pipe is provided outside the septic tank, it is not necessary to penetrate the partition partitioning the inside of the septic tank, and a troublesome sealing operation or the like becomes unnecessary.

In the purification tank according to the second aspect of the present invention, since the disinfection tank is provided outside the nitrification tank, the discharge pipe can be easily piped by making the disinfection tank a separate body. Design becomes easy.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a septic tank according to the present invention. FIG. 1 (a) is a plan view, FIG. 1 (b) is a sectional view, and FIG. 2 is another septic tank provided with a disinfecting tank outside the nitrification tank. 2A is a plan view, and FIG. 2B is a cross-sectional view.

As shown in FIGS. 1 (a) and 1 (b), a septic tank 10a according to the present invention comprises: a contaminant removing tank 11 provided with an inlet 11a into which treated water flows; The nitrification tank 13 containing the membrane separation device 14 and the disinfecting tank 17 is fractionated by partition walls 15, 15b, 16 each of which has an advection port 15a, 16a through which treated water can be transferred and whose upper end is made higher than the highest water level. It has been formed. The impurity removing tank 11 and the disinfecting tank 17 are connected to the discharge pipe 1
8 are connected.

[0011] As shown in FIG.
In 1, a filtering material 11 c is provided below the impurity removing tank 11. The treated water flowing in from the inflow port 11a flows into the lower part of the filter medium 11c by the pipe 11b connected to the inflow port 11a. As the filter material 11c, a porous body is formed by depositing a sphere made of resin and holding the sphere at the top and bottom.
When the treated water passes through the gap between the spheres of the filter medium 11c, solid fiber components contained in the treated water are supplementarily removed. The impurities in the fiber of the treated water are thus precipitated by the filter medium 11c, and the precipitate is biologically treated by anaerobic microorganisms. The treated water that has passed through the filter medium 11 c flows near the air lift pump 21 from a convection port 15 a opened in the middle of the partition wall 15. Then, the treated water is supplied to the partition wall 15.
The air is transferred to the denitrification tank 12 by an air lift pump 21 installed between the tank and the partition 15b.

A discharge pipe 18 is provided above the impurity removing tank 11 so that when a large amount of treated water temporarily flows into the impurity removing tank 11, the overflowed treated water can be discharged. The discharge pipe 18 connects the contaminant removal tank 11 and the disinfection tank 17 and is provided outside the purification tank 10. The bottom of the discharge pipe 18 in contact with the impurity removing tank 11 is installed so as to be at the highest water level of the impurity removing tank 11. The water level of the disinfecting tank 17 is lower than the designed maximum water level of the impurity removing tank 11. Therefore, the overflow water temporarily overflowing into the impurity removing tank 11 is discharged from the discharge pipe 1.
8 flows into the disinfection tank 17 having a low water level.

The denitrification tank 12 is provided between the impurity removing tank 11 and the nitrification tank 13. The treated water in the denitrification tank 12
The nitric nitrogen is denitrified and removed from the contaminant removal tank 11 by the air lift pump 21 using the BOD contained in the treated water as a carbon source. The denitrified treated water is supplied to the partition 16
Is transferred to the nitrification tank 13 from a transfer port 16a provided in the lower part of the tank. Nitrified treated water is circulated into the denitrification tank 12 by an air lift pump 22 provided in the nitrification tank 13. Then, advanced denitrification treatment is performed by mixing the treated water in the denitrification tank 12 with the nitrified treated water.

The nitrification tank 13 is provided with a membrane separation device 14 and a disinfection tank 17. The treated water is biologically treated by the aerobic microorganisms in the nitrification tank 13, whereby the ammoniacal nitrogen contained in the treated water is nitrified and the BOD is decomposed. The membrane separation device 14 is formed by juxtaposing a large number of flat filtration membrane plates. The filtration membrane plate is formed by fixing the periphery of the filtration membrane to the filtration membrane frame material. Membrane separation device 14
A space is provided between the filtration membrane plates and the internal space is provided with a conduit through which the treated water that has passed through the filtration membrane can be transferred, and the treated water is transferred to the disinfection tank 17 through the conduit. .

A diffuser 23 is provided below the membrane separator 14, and air is supplied to the diffuser 23 by a blower 24 provided separately. Air bubbles are sent into the nitrification tank 13 by the air diffuser 23 to supply oxygen. Bubbles ejected from the air diffuser 23 simultaneously with the supply of oxygen are also blown to the filtration membrane plate of the membrane separator 14 so that sludge does not adhere to the surface of the filtration membrane plate. As described above, the air discharged from the air diffuser 23 cleans the filtration membrane plate and aerates the inside of the nitrification tank.

In the treated water that has passed through the filtration membrane plate, solids and treated water are separated into solid and liquid by the filtration membrane, and the solids in the treated water are precipitated in the lower part of the nitrification tank 13. The treated water that has been separated into solid and liquid and has passed through the filtration membrane of the membrane separation device 14 is pumped by a pump 20.
Is pumped to the disinfection tank 17. Drug 17a in disinfection tank 17
The treated water disinfected in the above is discharged outside through a discharge pipe 17b. Another method of pumping water into the disinfection tank 17 is that the membrane separation device 14 is submerged in the nitrification tank, so that water can be pumped by an air lift pump using the water head pressure difference from the surface of the nitrification tank.

FIGS. 2A and 2B show another embodiment of the purification tank in which the disinfection tank 17 is provided outside the nitrification tank 13. FIG.
2A is a plan view, and FIG. 2B is a cross-sectional view. FIG.
(A), as shown in FIG. 2 (B), the disinfection tank 17 of the purification tank 10b is installed outside the nitrification tank 13. The treated water that has passed through the membrane separation device 14 provided in the nitrification tank 13 is pumped by a pump 20 and transferred to a disinfection tank 17 by a pipe 19. Other structures of the septic tank 10b are shown in FIGS.
The description is omitted because it is similar to the septic tank 10a shown in (b).

As described above, the septic tank 10a according to the present invention comprises:
The contaminant removal tank 11 and the disinfection tank 17 are connected by a discharge pipe 18 piped outside, and the bottom of the discharge pipe 18 in contact with the contaminant removal tank 11 is installed at the highest water level of the contaminant removal tank 11. Therefore, when the treated water more than the designed amount temporarily flows into the impurity removing tank 11, the overflowed treated water is directly transferred to the disinfection tank 17 by the discharge pipe 18, and can be dealt with without lowering the treatment capacity of the purification tank. be able to. In addition, since the discharge pipe 18 is provided outside the septic tank 10a, it is not necessary to penetrate the partition walls 15, 15b, and 16 that partition the inside of the septic tank 10a, and troublesome sealing work of the partition wall and the like become unnecessary. .

Further, in the purification tank 10b of the present invention, since the disinfection tank 17 is provided outside the nitrification tank 13, the disinfection tank 17 is provided.
Is separated, the discharge pipe 18 can be easily piped, and the design of the nitrification tank 13 and thereafter can be easily performed.

[0020]

According to the first aspect of the present invention, as described above, since the bottom of the discharge pipe that is in contact with the impurity removing tank is located at the highest water level of the impurity removing tank, the designed amount can be reduced. Even when the above-mentioned raw water flows in, it is possible to cope without reducing the processing capacity in the tank, and since the discharge pipe is provided outside, sealing work or the like when penetrating the partition wall becomes unnecessary.

In the septic tank according to the second aspect of the present invention, since the disinfecting tank is provided outside the nitrification tank, piping is easy if the disinfecting tank is separated, and the design after the nitrification tank is facilitated. .

[Brief description of the drawings]

FIG. 1 shows one embodiment of a septic tank according to the present invention, and FIG.
Is a plan view and FIG. 1B is a sectional view.

FIG. 2 shows another embodiment of a purification tank in which a disinfecting tank is provided outside a nitrification tank. FIG. 2 (a) is a plan view, and FIG. 2 (b) is a cross-sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10a, 10b Septic tank 11 Contaminant removal tank 12 Denitrification tank 13 Nitrification tank 14 Membrane separator 15, 15b, 16 Partition wall 15a, 16a Outflow port 17 Disinfection tank 17a Chemical 17b Discharge port 18 Discharge pipe 19 Pipe 20 Pump 21, 22 Air lift pump 23 diffuser 24 blower

Claims (2)

[Claims] 1. An inflow port into which treated water flows is provided, and an impurity removal tank for filtering and removing impurities, a denitrification tank, and a nitrification tank are each separated by a partition wall having an upper end higher than the highest water level. The treated water is transferred between the denitrification tank and the denitrification tank by an air lift pump, and the treated water between the denitrification tank and the nitrification tank is transferred between the denitrification tank and the nitrification tank. Advected from the provided advection port,
The circulating flow from the nitrification tank to the denitrification tank is performed by an air lift pump.The nitrification tank is equipped with a membrane separation device that separates the treated water into solid and liquid and a disinfection tank, and the treated water that has passed through the membrane of the membrane separation device is pumped. The contaminant removal tank and the disinfection tank are connected by a discharge pipe connected to the outside, and the bottom of the discharge pipe in contact with the contaminant removal tank is at the design maximum water level of the contaminant removal tank. A septic tank characterized by being installed. 2. The purification tank according to claim 1, wherein the disinfection tank is provided outside the nitrification tank.