JP2000271583A - Septic tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce production and maintenance costs and to demonstrate an enough sewage purification capacity stably by using sewage flowing convectively with a fluidized carrier by an oxygen-containing gas supplied from a diffusion pipe and transferring solids in the inner bottom part of a precipitation chamber to an aeration chamber. SOLUTION: Sewage is introduced into an anaerobic chamber 6, and by supplying air from a diffusion pipe 8, a fluidized carrier 7 supporting aerobic bacteria on its surface is made to flow vertically in convection with the sewage by the air in an aeration chamber 4. In the anaerobic chamber 6 and the aeration chamber 4, the sewage flowing convectively is used, the sewage in the chamber 6 is transferred to the chamber 4 through one communication opening 2a. During the transfer, the outflow of the fluidized carrier 7 is hindered, and the inflow of scum into the chamber 4 is hindered by a baffle 14. Since the fluidized carrier 7 is made to flow vertically in convection with the sewage, the lowering of a purification capacity by the clogging of a filter material can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a septic tank. This septic tank can be used for a single septic tank capable of purifying human waste and a combined septic tank capable of purifying miscellaneous wastewater in addition to human waste.

[0002]

2. Description of the Related Art Heretofore, as a general purification tank for purifying sewage water consisting of human waste and miscellaneous wastewater, a purification tank having a contact aeration type aeration chamber and a sedimentation chamber is known. In the aeration chamber, a filter medium (contact material) is fixed on the upper side, and a diffuser pipe connected to a blower for feeding an oxygen-containing gas such as air is provided below. The aeration chamber may be provided with a cylindrical cleaning cylinder whose lower end is opened at the bottom and extends vertically upward. A backwash tube connected to a similar blower and supplying an oxygen-containing gas may be provided below the aeration chamber. Further, in a combined septic tank having an anaerobic chamber partitioned by a partition on the upstream side of the aeration chamber, a transfer pipe having one end opened at the bottom of the aeration chamber and the other end opened to the anaerobic chamber may be provided. On the other hand, on the downstream side of the aeration chamber, a sedimentation chamber separated by a partition wall whose bottom communicates is adjacent.

In this type of septic tank, sewage is supplied into the aeration chamber from above. The sewage flows through the gap between the filter media, and is also decomposed by aerobic bacteria living on the surface of the filter media. receive. During this time, the air diffuser supplies oxygen to the aerobic bacteria. In the case of a septic tank equipped with a backwash tube, extra aerobic bacteria (solid matter) that adhered to the filter medium and propagated by the oxygen-containing gas supplied from the backwash tube whenever necessary can be separated from the filter medium. it can. The treated water thus purified to some extent is stored in the aeration chamber, and the treated water precipitates solids still contained in the downstream settling chamber, and the supernatant water is discharged with the addition of disinfecting water as desired. It will be.

The solids remaining in the sedimentation chamber are subject to the re-decomposition of the dirt by the aerobic bacteria in the aeration chamber, since the sedimentation chamber and the aeration chamber communicate at the bottom. In a combined septic tank equipped with a transfer pipe, the transfer pipe takes in the water flow generated by the oxygen-containing gas supplied from the same blower, so that the solid matter remaining in the aeration chamber is upstream from the transfer pipe. The anaerobic chamber is transported to the anaerobic chamber, where the anaerobic bacteria undergoes the decomposition of dirt. If the solid remains in the aeration chamber, the trader inserts a hose into the cleaning cylinder and pulls the solid through the hose.

[0005]

However, in the above-mentioned conventional general septic tank, since the filter medium is fixed in the aeration chamber, when the dirt is decomposed by the aerobic bacteria on the surface of the filter medium, the filter medium is removed. Clogging is likely to occur due to extra aerobic bacteria (solids). For this reason, the purification tank will cause a reduction in the purification ability as it is. Further, if extra aerobic bacteria (solids) are separated from the filter medium by the backwash tube to recover the purification ability, the production cost and the maintenance cost are increased by the amount of the backwash tube. .

[0006] In this regard, Japanese Patent Application No. Hei 10
As in JP-A-123072 and Japanese Patent Application No. 10-123073, a septic tank in which an aeration chamber is filled with a myriad of fluid carriers can be considered. In such a septic tank, since each fluid carrier having an aerobic bacterium on the surface convects up and down together with the sewage by the oxygen-containing gas supplied from the air diffuser, the purification ability due to the clogging described above may not be reduced. Absent. Rather, the oxygen-containing gas makes it easier for the aerobic bacteria to come into contact with the sewage while stably supplying oxygen to the aerobic bacteria. In addition, each fluid carrier collides, interferes, and abuts each other, and sticks to the surface, so that extra aerobic bacteria (solid matter) that has propagated can be removed. In this way, the sewage is easily decomposed by the aerobic bacteria, and the purification ability is enhanced. In addition, a backwash tube is not required, and the manufacturing cost and the maintenance cost can be reduced.

[0007] However, even in a septic tank having an aeration chamber using such a fluid carrier, if the solid matter remaining in the sedimentation chamber is hardly decomposed by aerobic bacteria in the aeration chamber, the result is satisfactory. It is difficult to obtain stable sewage purification ability. The present invention has been made in view of the above conventional situation, and provides a septic tank capable of stably exhibiting a satisfactory sewage purification ability while realizing low production costs and low maintenance costs. It is an issue to be solved.

[0008]

A septic tank according to the present invention is provided with a diffuser pipe for supplying oxygen-containing gas to stored sewage, and an aeration chamber for purifying the sewage with aerobic bacteria, and a partition communicating with a bottom. A septic tank having a sedimentation chamber adjacent to the aeration chamber while being separated by water and separating the sewage into solids and water by sedimentation, wherein the aerobic bacteria are supported on the surface of the aeration chamber, The oxygen-containing gas supplied from the trachea is filled with innumerable fluid carriers that convect up and down together with the wastewater, and the sedimentation chamber is convected with each of the fluid carriers with the oxygen-containing gas supplied from the air diffuser. It is characterized in that the solid matter at the bottom in the sedimentation chamber can be transferred to the aeration chamber by the sewage.

In the septic tank according to the present invention, in the aeration chamber, a myriad of fluid carriers carrying aerobic bacteria on the surface are convected up and down together with the sewage by the oxygen-containing gas supplied from the air diffuser. There is no reduction in the purification capacity due to clogging of the filter medium as in a septic tank having a contact aeration type aeration chamber. Rather, the oxygen-containing gas makes it easier for the aerobic bacteria to come into contact with the sewage while stably supplying oxygen to the aerobic bacteria. In addition, each fluid carrier collides, interferes, and abuts each other, and sticks to the surface, so that extra aerobic bacteria (solid matter) that has propagated can be removed. In this way, the sewage is easily decomposed by the aerobic bacteria, and the purification ability is enhanced. In addition, a backwash tube is not required, and the manufacturing cost and the maintenance cost can be reduced.

Further, in this septic tank, the solid matter at the bottom of the sedimentation chamber can be transferred to the aeration chamber in the sedimentation chamber by the sewage convection with each fluid carrier with the oxygen-containing gas supplied from the air diffuser. ing. For this reason, the solid matter remaining in the sedimentation chamber is easily susceptible to the decomposition of dirt by the aerobic bacteria in the aeration chamber, and as a result, a satisfactory sewage purification ability can be stably obtained.

As the fluid carrier, a carrier having a specific gravity close to that of water and having an outer shape that does not trap air bubbles while securing a large surface area can be adopted. A material whose specific gravity is close to the specific gravity of water, that is, a specific gravity of 0.8 to
This is because, if the material is formed of the material of 1.2, each of the fluid carriers becomes a floating state in the sewage by the oxygen-containing gas supplied from the air diffuser, and easily convects with the sewage up and down. As a material whose specific gravity is close to the specific gravity of water,
For example, a polyurethane foam having closed cells can be used.

The fluid carrier is made of a material having a specific gravity equal to or slightly smaller than the specific gravity of water, that is, a material having a specific gravity of 0.8.
It is preferable to be formed of a material of 00 to 0.999. In such a case, each fluid carrier is in a floating state in the sewage even if there is no water flow generated by the oxygen-containing gas, and it is easy to convect vertically with the sewage by the oxygen-containing gas. Specific gravity 0.800 to 0.99
As the material of No. 9, polypropylene or polyethylene having no closed cells can be used.

In order to increase the surface area of the fluid carrier,
The outer shape may be formed by plate-shaped or protruding projections and depressions, but it is preferable that these projections and depressions have a size that does not catch air bubbles and communicate with the outside. This is because, when the convex portions and the concave portions trap bubbles, the apparent specific gravity of the fluidized carrier becomes small, and the convectiveity becomes inferior or becomes discrete.

The fluid carrier is filled in the aeration chamber to such an extent that the sewage generates vertical convection. The sedimentation chamber is preferably formed narrower toward the bottom. In this case, the bottom side of the sedimentation chamber becomes negative pressure due to the sewage convection in the aeration chamber, and the solid matter at the bottom in the sedimentation chamber is transferred so as to be sucked into the aeration chamber (slot effect). It is preferable to adopt an inclined surface of the casing in order to form the sedimentation chamber narrower toward the bottom. In this case, the septic tank does not require a special member to generate the slot effect,
Since the structure is simple, it can be manufactured at low cost.

It is desirable that the partition wall connects the aeration chamber and the sedimentation chamber near the bottom dead center of the fluid carrier convection in the aeration tank. In the vicinity of the bottom dead center of the fluid carrier convection in the aeration tank, since each fluid carrier is likely to move in the horizontal direction, if the aeration chamber and the sedimentation chamber are connected at such a position, the bottom of the sedimentation chamber The side is more susceptible to negative pressure, which ensures a slot effect.

It is desirable that the sedimentation chamber is formed narrower toward the bottom due to the inclined surface of the casing, and that the partition wall connects the aeration chamber and the sedimentation chamber on the inclined surface. In this case, the solid matter stored in the bottom of the sedimentation chamber is guided by the inclined surface of the casing by gravity and easily moved to the aeration chamber, and each fluid carrier is more smoothly moved in the horizontal direction by the inclined surface of the casing. Because it is easy,
A slot effect surely occurs. Further, no special member is required to generate such a slot effect, the structure of the septic tank is simplified, and the manufacturing cost can be reduced.

Further, it is preferable that the air diffuser is provided so as to be able to supply an oxygen-containing gas from the bottom along one side wall of the aeration chamber opposite to the sedimentation chamber. In such a septic tank, the oxygen-containing gas rises along one side wall of the aeration chamber opposite to the sedimentation chamber, and sewage and countless fluid carriers reliably convect up and down in the entire aeration chamber, and the slot effect easily occurs. . Further, a separating member for preventing the outflow of each fluid carrier is provided at the bottom of the aeration chamber, and the separating member is preferably inclined or curved so as to have a downward slope toward the air diffuser. Thereby, at the bottom of the aeration chamber, each fluid carrier settling on the sedimentation chamber side is guided by the separating member and floated again by the diffuser tube, so that the convection of each fluid carrier becomes regular and the slot effect is obtained. Tends to occur.

The air diffuser is preferably provided at the bottom of the aeration chamber. In this case, the volume of the aeration chamber can be effectively used. Also, the upward flow generated by the rise of the bubble from the bottom becomes large, and a strong convection is obtained. Furthermore, if a separating member that is inclined or curved so as to have a downward gradient toward the air diffuser is employed, each fluid carrier can be regularly convected in a wide range of the aeration chamber, and sedimentation in the purification tank can be achieved. The slot effect is likely to occur in connection with the shape of the bottom of the chamber.

Therefore, the septic tank of the present invention can stably exhibit satisfactory sewage purification ability while realizing low production and maintenance costs.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments 1 to 3 embodying the present invention will be described below with reference to the drawings. (Embodiment 1) In Embodiment 1, the septic tank of the present invention is embodied as a household combined septic tank. In this septic tank, as shown in FIG. 1, a FRP partition 2 and a partition 3 extending vertically are fixed in an FRP casing 1.
An anaerobic chamber 6 is formed by the front inner surface of the casing 1 and the partition 2, an aeration chamber 4 is formed by the inner surface of the casing 1 and the partitions 2, 3, and a sedimentation chamber 5 is formed by the rear inner surface of the casing 1 and the partition 3. Is formed.

The aeration chamber 4 is filled with a myriad of fluid carriers 7 in a volume of about 20 to 80% of the volume of the aeration chamber 4. These fluid carriers 7 are formed of polyethylene having a specific gravity of 0.93. As shown in FIG. 3, each of the fluid carriers 7 has a thin annular support plate 7a, two short cylindrical members 7b and 7c coaxial with the support plate 7a, and a fan-like member having an inner angle of 90 degrees. And twelve blades 7d whose two sides are fixed to the one surface of the support plate 7a and the cylindrical member 7b so as to form a radial direction by 30 degrees in the circumferential direction, and a fan shape with an inner angle of 90 degrees, and two sides Consists of 12 blades 7e fixed to the other surface of the support plate 7a and the cylindrical member 7c so as to be located between the two blades 7d. Thus, each of the fluid carriers 7 has an outer shape that does not trap air bubbles while securing a large surface area.

2 and 4 are provided at the bottom of the aeration chamber 4.
As shown in FIG. 5 and also in FIG. 5, column-shaped diffuser tubes 8 and 9 are provided in parallel and horizontal to the partition wall 2, and the diffuser tubes 8 and 9 are formed as oxygen-containing gas by pipes 10 and 11 extending upward. Is connected to a blower 12 for feeding air. A cleaning cylinder (not shown) is also provided in the aeration chamber 4. further,
In the anaerobic chamber 6, a pair of baffles 14 and 15 are fixed to the partition 2. Above the partition 2, a part of the baffles 14 and 15 and the aeration chamber 4 are partially submerged in stored sewage. Two communication ports 2a and 2b having the same area and communicating with each other are provided through. These communication ports 2a, 2b are, as shown in FIG.
Both are opened at the same height and in the same width direction above the diffuser tubes 8 and 9 so that the submerged areas before the air is supplied from the diffuser tubes 8 and 9 are equalized.

Further, as shown in FIG. 1, the bottom of the partition 3 is open to the whole width direction, and the aeration chamber 4 and the sedimentation chamber 5 communicate with each other at the bottom. Since the lower rear wall of the casing 1 has an inclined surface 1b inclined forward, the sedimentation chamber 5 is formed narrower toward the bottom.
As shown in FIGS. 2 and 4, a plurality of brackets 16 to 19 are fixed to the left and right inner surfaces of the casing 1, and separation members are provided at the bottom of the partition 2, the brackets 16 to 19, and the bottom of the partition 3. Is fixed. Thus, the net member 20 is inclined so as to have a downward slope toward the air diffusers 8 and 9. Here, the net material 20 is
In order not to hinder the slot effect described below, the bracket is not fixed to the bottom of the partition wall 3 by a bracket, but is fixed by being tied up with a wire or the like.

As shown in FIG. 1, an inspection port 1a is opened above the aeration chamber 4 of the casing 1, and the inspection port 1a can be closed by a manhole 25. In the septic tank configured as described above, sewage first flows into the anaerobic chamber 6 through an inflow pipe (not shown).
On the other hand, a fixed amount of air is continuously supplied from the air diffusers 8 and 9. For this reason, in the aeration chamber 4, the respective fluid carriers 7 having aerobic bacteria carried on the surface thereof are convected up and down together with the sewage by the air supplied from the air diffusers 8 and 9. The mesh material 20 provided at the bottom of the aeration chamber 4 prevents the outflow of each fluid carrier 7. For this reason, the anaerobic chamber 6 and the aeration chamber 4 are connected to each of the fluid carriers 7 by the air supplied from the diffusion pipes 8 and 9, and one communication port 2 a transfers the sewage of the anaerobic chamber 6 to the aeration chamber 4. Transfer. At this time, diffuser tubes 8 and 9
The water level near each of the communication ports 2a and 2b is different due to the natural variation of the air caused by the variation of the pipes 10 and 11, and one communication port 2a transfers the sewage to the aeration chamber 4. I have. During this time, the scum does not flow into the aeration chamber 4 due to the baffle 14.

In this septic tank, since each fluid carrier 7 is convected up and down together with the sewage, the purifying ability is reduced due to clogging of the filter medium as in a conventional septic tank having a contact aeration type aeration chamber. Does not occur. Rather, the aerobic bacteria and the sewage are more likely to come into contact with each other while supplying oxygen stably to the aerobic bacteria by air.
In addition, the excess aerobic bacteria (solids) that have propagated because the respective fluid carriers 7 collide, interfere, and abut each other and adhere to the surface can be peeled off. Thus, the sewage is decomposed by the aerobic bacteria, and is purified with a high purification ability. Further, the conventional backwash tube is not required, and the manufacturing cost and the maintenance cost can be reduced.

The aerated chamber 4 stores treated water that has been purified to some extent. The treated water precipitates solids still contained in the settling chamber 5 on the downstream side. After the addition, the water is discharged through a discharge pipe (not shown). The solid matter remaining in the precipitation chamber 5 is
Since the sedimentation chamber 5 and the aeration chamber 4 communicate with each other at the bottom, the aerobic bacteria in the aeration chamber 4 are again subject to decomposition of dirt.

At this time, in this septic tank, as shown in FIG. 4, in the sedimentation chamber 5, the air supplied from the air diffusers 8 and 9 causes the sewage convection with the fluid carriers 7 to flow.
The solid matter at the bottom in the precipitation chamber 5 is transferred to the aeration chamber 4. In particular, since the sedimentation chamber 5 is formed narrower toward the bottom side due to the inclined surface 1b of the casing 1, the bottom side of the sedimentation chamber 5 becomes negative pressure due to sewage convection in the aeration chamber 4, and the sedimentation chamber 5
The solid matter at the bottom of the inside is transferred so as to be sucked into the aeration chamber 4 (slot effect). Further, the partition wall 3 communicates the aeration chamber 4 and the sedimentation chamber 5 near the bottom dead center of the fluid carrier 7 convection in the aeration tank 4, and each fluid carrier 7 is easily moved in the horizontal direction. , The bottom side of the sedimentation chamber 5 surely has a negative pressure, and the slot effect is surely generated. In addition,
This septic tank does not require a special member when producing such a slot effect, and has a simple structure.
It can be manufactured at low cost.

Further, since the diffuser tubes 8 and 9 supply air from the bottom along the one side wall of the aeration chamber 4 opposite to the sedimentation chamber 5, one side wall of the aeration chamber 4 opposite to the sedimentation chamber 5 is provided. , The sewage and the myriad of fluid carriers 7 are surely convected up and down in the entire aeration chamber 4, and the slot effect is effectively generated. Further, since the net member 20 is inclined so as to have a downward gradient toward the air diffusers 8 and 9, each of the fluid carriers 7 sinking in the sedimentation chamber 5 at the bottom of the aeration chamber 4 is attached to the net member 20. The fluid carrier 7 is guided and floated again by the air diffusers 8 and 9, so that the convection of each fluid carrier 7 becomes regular and the slot effect is easily generated.

Further, the air diffusers 8 and 9 are provided at the bottom of the aeration chamber 4 to effectively utilize the volume of the aeration chamber 4 and increase the upward flow generated by the rise of the bubbles from the bottom, which is strong. Convection will be obtained. Further, since the net member 20 is inclined so as to have a downward slope toward the diffuser tubes 8 and 9, each fluid carrier 7 can be regularly convected in a wide range of the aeration chamber 4, The slot effect is more likely to occur.

For this reason, in this septic tank, the solid matter remaining in the sedimentation chamber 5 is liable to be decomposed by the aerobic bacteria in the aeration chamber 4, and as a result, a satisfactory sewage purification ability can be stably obtained. . The anaerobic chamber 6 and the aeration chamber 4 are contaminated by air supplied from the diffusing pipes 8 and 9 together with the respective fluid carriers 7, and the sewage in the aeration chamber 4 is lowered below the anaerobic chamber 6 by the communication port 2 b. It is refluxed toward.
At this time, the communication ports 2a, 2a, 2b, and 2d are caused by natural variations in air caused by variations in the air diffusers 8, 9 and the pipes 10, 11, etc.
A difference occurs in the water level in the vicinity of the anaerobic chamber 6 through the communication port 2b. Thus, the sewage is subject to decomposition of the dirt by the anaerobic bacteria in the anaerobic chamber 6. When the solids remain in the aeration chamber 4, a trader inserts a hose into the cleaning cylinder and pulls out the solids with the hose.

Therefore, in the septic tank according to the first embodiment, a satisfactory purification ability of sewage can be stably exhibited while reducing the production cost and the maintenance cost.
In the clarification tank of the first embodiment, the anaerobic chamber 6 purifies stored sewage by anaerobic bacteria. However, the anaerobic chamber 6 may be a sedimentation separation tank (rot tank) not containing a filter medium. An anaerobic filter bed tank in which a filter medium is placed may be used. The anaerobic chamber 6 can be constituted by a first anaerobic chamber and a second anaerobic chamber located downstream of the first anaerobic chamber. (Embodiment 2) In the septic tank according to Embodiment 2, as shown in FIG. 6, an inclined portion 3a is provided at the lower end of the partition wall 3 and slightly inclined toward the aeration chamber 4 in parallel with the inclined surface 1b of the casing 1, thereby forming a sediment. A long narrow portion is secured on the bottom side of the chamber 5.
Further, the net material 21 is curved so as to have a downward slope toward the air diffusers 8 and 9. Other configurations are the same as the septic tank of the first embodiment.

In this septic tank, since the narrow portion is long at the bottom side of the sedimentation chamber 5, the slot effect is larger. In addition, the curved net material 21 is provided for each of the sinking fluid carriers 7.
Is smoothly guided to the side of the air diffusers 8 and 9 to exert a greater slot effect. Other functions and effects are the same as those of the septic tank of the first embodiment. (Embodiment 3) In the septic tank of Embodiment 3, as shown in FIG.
And the precipitation chamber 5 are communicated. Another configuration is the first embodiment.
It is the same as the septic tank.

In this septic tank, the solid matter stored at the bottom of the sedimentation chamber 5 causes the inclined surface 1 of the casing 1 to move due to gravity.
b and is easily moved to the aeration chamber 4. Further, the inclined surface 1b of the casing 1 makes it easier for each fluid carrier 7 to move more smoothly in the horizontal direction. For this reason, the slot effect reliably occurs. Other functions and effects are the same as those of the septic tank of the first embodiment.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a combined septic tank according to a first embodiment.

FIG. 2 relates to a combined septic tank according to the first embodiment, and corresponds to II- in FIG.
It is II sectional drawing.

FIG. 3 is a perspective view of a fluid carrier according to the merged septic tanks of Embodiments 1 to 3.

FIG. 4 is an enlarged sectional view of a main part of the merged septic tank of the first embodiment.

FIG. 5 relates to the combined septic tanks of Embodiments 1 to 3, and corresponds to V in FIG.
FIG.

FIG. 6 is an enlarged sectional view of a main part of a combined septic tank according to a second embodiment.

FIG. 7 is an enlarged sectional view of a main part of a combined septic tank according to a third embodiment.

[Explanation of symbols]

 8, 9 ... diffuser tube 4 ... aeration chamber 2, 3 ... partition wall 5 ... sedimentation chamber 7 ... fluid carrier 1 ... casing 1b ... inclined surface 20, 21 ... separation member (net material)

Claims (8)

[Claims] An aeration tube for supplying oxygen-containing gas to stored sewage is provided, and an aeration chamber for purifying the sewage with aerobic bacteria and an aeration chamber adjacent to the aeration chamber while being separated by a partition having a bottom communicating therewith. A septic tank having a sedimentation chamber that separates the sewage into solids and water by sedimentation.In the aeration chamber, the surface of the aerobic bacteria is carried, and the oxygen-containing gas supplied from the air diffusion tube is used. The sedimentation chamber is filled with an innumerable fluid carrier that convects up and down together with the sewage, and the sedimentation chamber is solidified at the bottom of the sedimentation chamber by the sewage convection with the fluid carrier with the oxygen-containing gas supplied from the air diffuser. A septic tank capable of transferring an object to the aeration chamber. 2. The septic tank according to claim 1, wherein the sedimentation chamber is formed narrower toward the bottom. 3. The septic tank according to claim 2, wherein the slanted surface of the casing makes the sedimentation chamber narrower toward the bottom. 4. The septic tank according to claim 1, wherein the partition wall connects the aeration chamber and the sedimentation chamber near the bottom dead center of the flow carrier convection in the aeration chamber. 5. The sedimentation chamber is formed so as to become narrower toward the bottom part due to the inclined surface of the casing, and the partition wall connects the aeration chamber and the sedimentation chamber on the inclined surface.
The septic tank described. 6. The air diffusion tube is provided so that an oxygen-containing gas can be supplied from the bottom along one side wall of the aeration chamber opposite to the sedimentation chamber. Or the septic tank according to 5. 7. A separating member is provided at the bottom of the aeration chamber for preventing the outflow of each fluid carrier, and the separating member is inclined or curved so as to have a downward slope toward the air diffuser. The septic tank according to claim 1, 2, 3, 4, 5 or 6. 8. The air diffusion tube is provided at the bottom of the aeration chamber.
The septic tank described.