JPH02222780A - Structure of collecting inlet chamber of septic tank - Google Patents

Abstract

PURPOSE:To adequately maintain the activity of anaerobic bacteria by lifting a part of the treated water during the decomposition treatment in an aerobic treatment chamber by the air lift effect of an air lift pipe into a collecting inlet chamber and returning only the specified volume thereof into an anaerobic treatment. CONSTITUTION:Air is supplied into the treated water from an air diffusion pipe 13b and the treated water under the aerobic decomposition treatment is lifted partly into the collecting inlet chamber 40 in the aerobic treatment chamber a3 by the air lifting effect of an air lift pipe 14. The specified volume of the water is returned via a triangular weir in the collecting inlet chamber 40 into the 1st chamber a1 of the anaerobic treatment chamber C through a reflux pipe 70 so that the decomposition treatment of org. matter is executed by not only the anaerobic bacteria but a part of the reflux water and the denitrifying bacteria thereof as well. The volume of the transfer from the anaerobic treatment chamber C to the aerobic treatment chamber a3 is regulated to the volume obtd. by adding the specified volume of the reflux water to the volume of the treated water flowing from a sewage discharge pipeline D. The treated water is released from a release port 17 through a settling separating chamber a4 and a disinfecting chamber 18. The activity of the anaerobic bacteria is maintained always adequately in this way and the efficiency of the treatment to decompose the org. matter is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a water catchment structure in a septic tank.

(b) Conventional technology Traditionally, as a form of septic tank, Utility Model Application No. 63-45894
There is something described in the publication.

That is, in the septic tank, as shown in FIG. 15, the septic tank has a first part into which wastewater flows into the septic tank main body (90).

an anaerobic treatment chamber (91) and a second anaerobic treatment chamber (9) into which wastewater anaerobically treated in the first anaerobic treatment chamber (91) flows.
2), an aerobic treatment chamber (93) into which sewage that has been further anaerobically treated in the second anaerobic treatment chamber (92) flows in, and sewage that has been aerobically treated in the same aerobic treatment chamber (93) flows into it. It consists of a precipitation separation chamber (94) in which the precipitation separation chamber (94) is separated, and a disinfection chamber (95) into which the supernatant liquid separated in the precipitation separation chamber (94) flows.

(c) Problems to be Solved by the Invention However, in the case of the above-mentioned septic tank, the concentration of ammonia nitrogen generated by anaerobic decomposition of organic nitrogen in the first and second anaerobic treatment chambers (91) and (92). When this value becomes high, the activity of anaerobic bacteria is suppressed, resulting in a problem that the anaerobic treatment capacity decreases.

(d) Means for Solving the Problems Therefore, in the present invention, an aeration pipe is arranged at the lower part of the aerobic treatment chamber, the lower end of the air lift pipe is opened above the aeration pipe, and the upper end of the air lift pipe is opened above the aeration pipe. is communicated with the anaerobic treatment chamber via a water collection basin, and air is supplied to the aeration pipe through the air piping, thereby supplying air into the treated water from the aeration pipe, which is preferable due to the air lift action of the air lift pipe. In a septic tank configured so that a part of the treated water undergoing aerobic decomposition treatment in the aerobic treatment chamber is pushed up into a water collection basin, and a certain amount of water is continuously returned from the collection basin to the anaerobic treatment chamber. The purpose is to provide a water catchment structure.

The water collection basin is formed into a substantially box shape, and a communication port communicating with the anaerobic treatment chamber is opened in one side wall of the water collection basin, and an overflow opening is cut out in the other side wall of the same water collection basin. and the height from the bottom of the catch basin to the lower edge of the overflow opening is higher than the height from the bottom of the catch basin to the lower edge of the communication opening, so that it is connected to the bottom of the catch basin. Another feature is that a certain amount of the treated water during the aerobic decomposition process, which is pushed up into the water collection basin through the air lift pipe, can be returned to the anaerobic treatment chamber through the communication port.

(E) Embodiment The embodiment of the present invention will be explained in detail based on the drawings. In Figs. 1 and 2, (^) indicates a domestic septic tank, and the septic tank (A) is the septic tank body (a). and a lid body (b), and is installed in the middle of a pipe that discharges wastewater from a household toilet, kitchen, etc.

As shown in Figures 1 to 3, the septic tank body (a) is approximately box-shaped with an open top, and the inside is partitioned into partitions (1) + 2) (3).
are set upright at regular intervals in the longitudinal direction, the internal space is divided into a first chamber (al) forming an anaerobic treatment chamber (C).
), a second chamber (a2), an aerobic treatment chamber (a3), and a sedimentation separation chamber (a4) in which a disinfection chamber (18) is provided.

The first chamber (al) communicates with the upstream side of the sewage discharge pipe (D) via an inlet (4), and the inlet (4) has a substantially horizontal ゛ shape and is connected to the sewage discharge pipe. The wastewater (hereinafter referred to as "treated water") flowing into the first chamber (al) from (0) is guided downward in a curved manner.

Also, directly below the inlet (4) is a second chamber (a2).
A baffle plate (25) that is inclined toward the side with a lower front and a higher rear is arranged to direct the wastewater flowing in from the inlet (4) along the baffle plate (25) in a downward direction as described below. It is made to fall onto the flowing anaerobic hearth (5). (26) is a baffle plate stay.

In this way, by arranging the baffle plate (25), it is possible to prevent the problem that the treated water passes straight through the first chamber (1a) and the purification process is not performed, and also to prevent the treated water from being purified. Prevention of air entrainment into the first chamber (al) where anaerobic treatment is performed by linear inflow, and prevention of air contact by destruction of the scum layer formed on the treated water surface in the first chamber (al). Efforts are being made to prevent the occurrence of noise.

Further, in the first chamber (al), a downward flow anaerobic hearth (5) is provided at a predetermined interval downward from the inlet (4). 5) is a support (6) (6") fixed to the inner surface of the septic tank body (a) and the partition wall (1).
Upper and lower P material shelves (7) (7°) with lattice-like patterns on the top and bottom of the
is stretched, and P material to which anaerobic bacteria is attached is filled between the upper and lower furnace material shelves (7) (7 degrees).

The furnace material is made of synthetic resin or other materials to significantly increase its surface area and porosity.

The second chamber (a2) accommodates an upward flow anaerobic hearth (9) inside, and is approximately the same as the above-mentioned downward flow anaerobic hearth (5). It differs from the hearth (5) in that it has a smaller porosity and a larger surface area. (8
) (8') are upper and lower baffle shelves, (8a) and (8b) are supports.

In particular, the partition wall (1) that divides the first chamber (al) and the second chamber (a2) completely partitions the area below the treated water level (h) in the septic tank body (a), and the first chamber ( Advection of the treated water from the first chamber (a2) of the partition wall (1) to the second chamber (a2)
l)ff+! ! This is carried out through the first and second advection pipes (1o) (H) that are installed upright along the side surface of the second chamber (a2).

As shown in FIG.
In a symmetrical position with one edge separated from each other! (1
), the other edge of each was brought into close contact with the inner surface of the side wall (20) of the septic tank body (a), and the upper and lower ends were open above and below each hearth (5) and (9), respectively. A partition wall (1) forming a tube body and between each advection tube (10011)
A substantially rectangular communication port (21) extending from above to a position slightly lower than the treated water level (h) is cut out to communicate the first chamber (al) and the second chamber (a2).

The first and second advection pipes (10) and (11) are
A partition wall (
1), one set each on the left and right sides, a total of two sets, and the first room (al)
A pair of communication ports (21) are also provided on the left and right to communicate between the first chamber and the second chamber (a2), and a movable weir (3o) is attached to each communication port (21) so as to be slidable in the vertical direction.

The movable weir (30) is formed into a rectangular plate shape slightly wider than the width of the communication port (21), and has an upper edge (30a).
The side of the septic tank body (a) that is close to the partition wall (1) is formed into a sawtooth shape! (20) and the inner surface of the side wall of the second advection tube (11) facing the same inner surface, respectively, are fitted into guide rails (31) (31°) so as to be vertically slidable.

In addition, a vertical adjustment bolt sliding groove (32) is formed in the center of the movable weir (30) from the lower end to the center, and the sliding adjustment bolt is passed through the sliding groove (32) and attached to the partition wall (1). (33), and screw a nut (34) with an adjustment knob onto the tip of the adjustment bolt (33) so that the tightening can be freely adjusted.
30) is slid and fixed up and down so that the vertical position can be adjusted. (35) is a fixed plate.

Next, the configuration of the aerobic treatment chamber (a3) will be explained.

First, referring to FIG. 1, the configuration for transferring treated water from the second chamber (a2) of the anaerobic treatment chamber (C) to the aerobic treatment chamber (a3) will be explained. The partition wall (2) between the aerobic treatment chambers (a3) completely partitions the area below the treated water level (h) of the septic tank body (a), and separates the second chamber (
The advection of treated water from a2) to the aerobic treatment room (a3) is as follows:
This is performed by the third advection pipe (16) provided on the side surface of the second chamber (a2) at the interval u(2).

The third advection pipe (16) is formed in a substantially U-shaped cross section with open upper and lower ends, and the opening edge of the U-shaped cross section is brought into close contact with the side surface of the partition wall (2) on the second chamber (a2) side. A third advection tube (16) whose lower end opens above the upward flow anaerobic hearth (9) and whose upper end opens above the treated water level (h) is formed, and is connected to the partition wall (2). The substantially rectangular advection port (16a) is opened to connect the second chamber (a2) and the aerobic treatment chamber (a3) to each chamber (a2Ha3).
) are connected at the top.

As shown in FIGS. 1, 3, and 4, the aerobic treatment chamber (a3) has an aerobic hearth (12) and an aeration device (1) inside.
3), an air lift pipe (14), and a backwash pipe (15) are built-in. (The air lift pipe (14) is a part of the treated water partial recirculation device (E), which will be described later, and will be explained in the explanation section (E).) First,
To explain the aerobic hearth (12), the aerobic hearth (12) has a frame (12a) sunk in the aerobic treatment chamber (a3) at a predetermined distance from the inner bottom surface, and a fiber attached to the center string. A string-like material (1
2b), and aerobic bacteria are attached to the string-like swamp material (12b).

In addition, in the present invention, string-shaped furnace material (
12b) was used, but a corrugated plate shape or a honeycomb shape may also be used.

The aeration device (13) has a second chamber (a2) and an aerobic treatment chamber (
Air vertical pipe (13) installed vertically along the partition wall (2) between a3)
Aeration pipes (13b) [13b] each having a large number of air jet holes (13d) provided at regular intervals in the axial direction are connected in a substantially horizontal manner from the lower end to the left and right sides of a), and the air is Air is supplied to the upper end of the vertical pipe (13a) via an air pipe (t3c) and is supplied into the treated water from the air outlet (13d).

With this configuration, the vertical air pipe (13a) and the air diffuser pipe (
13bH13b) through the aerobic treatment chamber (a3)
It is possible to maintain the activity of aerobic bacteria.

In addition, a diffuser pipe (13C) is installed in the middle of the air pipe (13C).
b) An air adjustment unit for adjusting the amount of air supplied to (
50) and a three-way ball valve (55) for switching and supplying the air supplied to the diffuser pipe (13b) to a backwash pipe (15) to be described later.

Also, there are convection guide plates (60) directly above the left and right air diffusers (13bH13b) and near the treated water surface (h).
(61) are arranged, and each convection guide plate (60) (6
1) has supporting members (62) (63) with their lower ends separated by u(2).
), and the middle part is curved upward in a convex manner, and the upper end is brought close to the treated water surface (h).

Therefore, the convection of the treated water in the aerobic treatment chamber (a3) by the air diffused from the air diffuser pipes (13b) (13b) can be promoted, and the supply of air to the aerobic bacteria can be promoted.

Moreover, a constant gap (S) (S) is formed between the lower end of each convection guide plate (60) +61) and the partition wall (2), and the upper end of each convection guide plate (eO) (61) is This prevents problems such as solid matter remaining in the treated water and rotting.

Next, the backwash pipe (15) will be explained.
15) is a cord-shaped hearth material (12) in an aerobic hearth (12).
1)) Excess sludge adhering to the sludge is periodically removed to maintain the activity of aerobic bacteria.

As shown in Figures 1 and 4, the backwash pipe (15) is
Partition wall between aerobic treatment chamber (a3) and sedimentation separation chamber (a4)
3) A backwash vertical pipe (15b) is installed vertically along the backwash pipe (15b), and one end of an air jet pipe +158) arranged substantially horizontally below the aerobic P bed (12) is connected to the lower end of the backwash vertical pipe (15b), On the other hand, connect the upper end of the above-mentioned backwash pipe (15b) to the flexible pipe (15c).
), the air pipe (13c) is supported in a cantilevered manner and communicated with the air pipe (13c).

Next, a treated water partial reflux device (E) for refluxing a part of the treated water in the aerobic treatment chamber (a3) to the first chamber (al) of the anaerobic treatment chamber (C) will be described.

That is, the treated water partial recirculation device (E) has an air lift pipe (14) arranged vertically along the partition wall (2), with the lower end opening above one of the aeration pipes (13b). A water collection basin (40 mm) with the end placed slightly above the treated water level (h)
), the water collection basin (40) is connected to the base end of the return pipe (70) that penetrates the partition wall (2), and the tip of the pipe (70) is connected to the upper part of the first chamber (al). The distal end portion thereof is bent downward to open below the treated water surface (h).

Then, by supplying air to the aeration pipes (13b) (13b) through the air piping (13c), air is supplied from the aeration pipes (13b) (13b) into the treated water, and the air lift pipe (13b) is supplied with air into the treated water. 14), a part of the treated water undergoing aerobic decomposition treatment in the aerobic treatment chamber (a3) is pushed up into the water collection basin (40), and the same water collection basin (40) is pushed up.
40) through the reflux pipe (70) into the first chamber (al
), and decomposition of organic matter in the first chamber (al) can be carried out not only by anaerobic bacteria but also by partial reflux water from the aerobic treatment chamber and denitrifying bacteria acting on it. I'm trying to make it possible.

In addition, the transfer amount of treated water from the anaerobic treatment room (C) to the aerobic treatment room (a3) is a constant amount based on the amount of treated water flowing into the anaerobic treatment room (C) from the wastewater discharge pipe (0). The amount of aerobic treated water ( The amount discharged from a3) to the downstream side of the wastewater discharge pipe (D) from the discharge port (17) via the sedimentation separation chamber (a4) and the disinfection room (18) described later is determined by the amount discharged from the wastewater discharge pipe (D) described above. From the anaerobic treatment chamber (
The amount of treated water flowing into C) can be made equal to the amount of treated water flowing into the interior.

In addition, as shown in FIGS. 5 and 6, the air lift pipe (14) has an upper end (8
0b) are connected in communication, and the air collecting umbrella (80) is
The lower end opening (80a) is formed wide in the axial direction of the air diffuser pipe (13b), and the lower end opening (8Qa) is brought close to the air diffuser pipe (13t).

Then, by the air collecting umbrella (80), the air diffuser (1
3b) Ensure that the air diffused from the air lift pipe (14)
) to ensure the air lift action of the air lift pipe (14) and ensure smooth and reliable return of the treated water into the anaerobic treatment chamber (C).

In addition, in Figures 5 and 6, (81) is an air collecting umbrella (8
0) is vertically slidably supported, (82) is an aeration pipe support bracket, (83) is an air pipe support bracket, and each bracket (81) (8
2) (83) is fixed to the partition wall (2).

The water collection basin (40) constitutes the gist of the present invention, and as shown in FIGS. It consists of a partition plate (42) that partitions the inside of the water basin body (41).

The water collection basin main body (41) is attached to the upper part of the bulkhead (2) in a cantilevered manner rearward so that its vertical sliding position can be adjusted freely. A triangular weir (44) for communicating with the reflux pipe (70) is cut out from the upper end of the front wall (43), and a substantially rectangular overflow opening is formed from the upper end of the rear wall (45). (46) is formed with a notch.

Further, the triangular weir (44) is aligned with the reflux opening (2a) provided in the partition wall (2), and is connected to the reflux opening (2a).
It communicates with a reflux pipe (70) whose ends are connected for communication.

In addition, (41a) and (41a) are mounting ears provided on the left and right side walls of the front end of water collection area #(41), and the mounting ears (41a) and (41a) are provided with vertical slides, respectively. The elongated holes (41a) (41a) are each provided with a vertically elongated elongated hole (41b041b) for the slide.
1b) Insert the mounting bolts (41c) (41c) that protrude rearward from the partition wall (2) into the mounting bolts (41c) (41c), and tighten the tightening adjustment nuts (41d) into the mounting bolts (41c) (41c).
) (41d) and tighten the same tightening adjustment nut (41d).
) (41d) allows the water collection basin main body (41) to be slid up and down along the partition wall (2).

Further, the partition plate (42) is provided inside the water collection basin body (41) on a diagonal line upward to the right in plan view.
Triangular weir inside 41) (44)l! 11 and the overflow opening (46) side, and the same partition plate (4
2) a substantially rectangular water hole (42a) is opened at the bottom of the
Triangular weir (44) side and overflow opening (46) f
f! ! It communicates with I through the same water hole (42a).

In this way, the partition plate (42) allows the water collection basin body (4
1) By forming a detour flow path inside, it is possible to prevent the treated water from directly flowing into the return pipe (70) from the upper end opening of the air lift pipe (14), suppress pulsation, and keep the treated water constant. can be sent to the first chamber (al).

In addition, the bottom surface of the water collection basin body (41) is located on the overflow opening (46) side, and the upper part of the air lift pipe (14) is passed through, and the upper end opening (14a) is connected to the water passage hole. (42a) is located above.

With this configuration, a part of the treated water during the aerobic decomposition process is pushed up in the airlift pipe (14) by the airlift action of the airlift pipe (14), and
4) Gas and liquid are separated by overflowing into the water collection basin main body (41) from the upper end opening (14a).

The treated water in the water collection basin body (41 mm) is
Only the water that has flowed into the triangular weir (44) through 2a) overflows the triangular weir (44) and flows into the reflux opening (2a).
It is made to flow more into the reflux pipe (70).

At this time, the overflow opening (
The lower end of the opening of 46) is set by adjusting the vertical sliding position of the water collection basin body (41) so that it is located at the same level as or above the lower end of the opening edge of the reflux opening (2a), and The overflow opening (46
) is returned to the aerobic treatment chamber (a3), so that the amount of treated water that passes through the reflux vibe (70) and is refluxed to the first chamber (al) can be kept constant.

In this way, by maintaining the 11M reflux amount,
The anaerobic treatment in the anaerobic treatment chamber (TC) and the aerobic treatment in the aerobic treatment chamber (a3) can be maintained in optimal conditions.

In addition, (, 10') shown in FIG. 10 is a water collection basin as another embodiment, and the upper edge of the partition plate (42') is placed behind the upper edge height of the water collection model # (41). The upper cover (42'a) is extended in a folded manner to partially cover the upper surface of the water collection basin main body (41).

This upper cover (42'a) allows the air lift pipe (
14) The treated water spouted from the upper end opening (14a),
This prevents the gas from flowing beyond the partition plate (42°) into the reflux pipe (70) without being separated into gas and liquid.

In addition, as shown in Fig. 11, a water collection pipe fi (47) is attached to the upper surface of the water collection pipe main body (41), and the water collection pipe waka (
47), the treated water directly flows from the upper end opening of the air lift pipe (14) over the partition plate (48) into the return pipe (70). You can also prevent it from happening. in this case,
The height of the partition plate (48) is equal to the height of the water collection basin main body (41) and the height of the water collection basin body (41), so that there is no problem in closing the lid of the water collection basin fi +47). (48a) is a water hole.

As shown in FIG. 12, the reflux pipe (70) is connected to a first pipe (71) located in the first chamber (al) and a second pipe (71) located in the first chamber (al).
a2) and the second pipe (72) located within the partition wall (1).
They are connected by a connecting pipe (73) provided at the top of the.

The second pipe (72) connects the connection pipe (73) and the reflux opening (2) in the second chamber (a2).
a) is connected to the first chamber (al) in a downwardly inclined manner.

Further, the first pipe (71) has a male threaded portion (71) provided at the base end of the connecting pipe (73) in the first chamber (al).
a) is removably screwed on and cantilevered in the same axial direction as the second vise (72), and the tip is pushed downward L.
The tip opening f71b) is bent into a letter shape so that the treated water surface (
h) (see Figure 1).

Therefore, when a part of the treated water during aerobic treatment is refluxed, it is possible to prevent the occurrence of a problem in which air is drawn in and the treated water in the first chamber (al) is excessively oxidized. .

Furthermore, the first vib (71) can be opened at the tip opening (71b) by screwing the proximal end onto the connecting pipe (73) as described above and rotating the first vib (71) around the axis.
) can be adjusted in height.

Therefore, the water level of the treated water in the first chamber (al) decreases,
Even when the tip opening 171b) is located above the treated water level (h), the same can be achieved by rotating the first pipe (71) and adjusting the tip opening (71b) to a lower position as described above. The tip opening (71b) can be secured below the treated water surface (h).

In addition, on the upper surface of the midway part of the first and second pipes (71) and (72), there is a notch opening (71) that is longitudinal in the axial direction of each pipe.
C) (72C) and each notch opening (71cN72c
) so that the inside of each pipe (71) (72) can be cleaned.

Therefore, from each notch opening (71c) (72C), the first
The interior of the second pipes (71, 72) can be reliably cleaned, and the treated water recirculation function of the pipes (71H72) can be ensured well.

In addition, on the base side of the second pipe (72), there is a reflux treated water recovery section (74) for collecting and measuring the reflux treated water layer.
has been established.

That is, as shown in FIGS. 12 to 14, the reflux treated water collecting section (74) has an inversion tube (75 tubes) fitted onto the outer peripheral surface of the base side of the second pipe (72) so as to be able to be turned upside down. , a collection port (7G) that can be aligned with the outflow port (72d) opened on the lower surface of the base side of the second pipe (72) at the same inversion fW (75).
Open the collection funnel (77), attach the proximal end of the collection funnel (77) to the outer peripheral surface of the collection port (76) (Im) of the reversing tube (75), and open the tip opening (77a) of the collection funnel (77) to the collection port (Im). 76)
The opening is made at a position that corresponds to the .

In addition, the front end portions (75a) (75b) of the reversing tube (75)
The second pipe (72) is held in a water-tight state so as to be freely invertable by the inverting cylinder holding parts (78) and (79) provided on the outer circumferential surface of the second pipe (72).

(79a) is a waterproof jacket.

With this configuration, the reversing tube (75) is connected to the tip opening (77).
When a) is turned over so that it faces downward, the same tip opening (
77a) and the collection port (78) are aligned with the outlet (72d) of the second pipe (72), and the treated water flowing back through the second pipe (72) is collected from the tip opening (77a). Can be done.

Therefore, it is possible to easily check whether the appropriate amount of treated water is being refluxed by the collected amount of treated water, and if the appropriate amount of treated water is not being refluxed, the appropriate amount of treated water is quickly refluxed. By taking these measures, it is possible to ensure the purification function of the septic tank.

In addition, by inverting the inversion tube (75) so that the tip opening (77a) faces upward, the outlet (72d) is closed by the inversion tube (75), and the reflux treated water is transferred to the first pipe ( 71) It can flow to the side.

As mentioned above, the structure inside the aerobic treatment chamber (a3) has been explained, but below, other structures of the septic tank (^) will be explained.

As shown in FIGS. 1 and 3, the sedimentation separation chamber (a4) is composed of a partition wall (3) and a space between the partition wall (22) of the disinfection chamber (18).

The disinfection room (18) is connected to the sedimentation separation room (a4) by the partition wall (22).
It has a box shape with an open top and one side is brought into close contact with the inner surface of the side wall of the septic tank body (a) to communicate with the discharge port (17), and the upper edge (18c) of the disinfection chamber (18) is connected to the treated water surface. (h), and a drug part support (18a) is provided protrudingly at a position slightly higher than the treated water level (h) on the inner surface of the disinfection chamber (18). The lower end of 1 m (18b) filled with a solid disinfectant inserted from the container is supported while being in contact with the treated water advected from the sedimentation separation chamber (a4).

In addition, (19) is a scum outflow prevention plate that is vertically opposed and protrudes from the partition wall (3) on both the left and right sides of the disinfection chamber (18), and the scum outflow prevention plate (19) disinfects the sides. The scum floating on the treated water surface (h) of the sedimentation separation chamber (a4) is placed in close contact with the chamber, the upper edge protrudes above the treated water surface (1), and the lower edge is immersed below the treated water surface (h). is prevented from advecting from the sedimentation separation chamber (a4) to the disinfection chamber (18).

Further, the lower edge of the partition wall (3) between the sedimentation separation chamber (a4) and the aerobic treatment chamber (a3) is provided with a predetermined distance (n) from the inner bottom surface of the septic tank body (a). The inner bottom surface of the sedimentation separation chamber (a4) is steeply inclined downward toward the aerobic treatment chamber (a3).

As shown in FIGS. 1 and 2, the lid body (b) is fixed to a flange (a5) fixed to the upper edge of the septic tank body (a) via bolts (not shown), or Or it is adhesively bonded with synthetic resin to close the upper opening of the septic tank main body (a), and the upper position of the partition wall (1) of the septic tank main body (a) and the upper position of the aerobic treatment chamber (a3). The first large diameter
, a second manhole (bIHb2) is provided so as to be openable and closable, and a small-diameter third manhole (bIHb2) is provided above the drug cylinder (18b).
3) It is provided so that it can be opened and closed freely.

Hereinafter, a method for purifying wastewater from a household toilet or kitchen using a septic tank having the above configuration will be described with reference to FIG. 1.

The treated water flowing into the first chamber (al) from the upstream side of the sewage discharge pipe (D) through the inlet (4) and the organic matter (water, carbohydrates, proteins, lipids, urea) contained in the treated water While passing through the downward flow anaerobic hearth (5), the anaerobic bacteria (component of which are the components of

That is, first, the organic matter in the treated water is reduced in molecular weight by acid-producing bacteria and converted into organic acids such as acetic acid (CHa COQII) and propionic acid (CHa CH2Cool>), and then the organic acids are converted into organic acids by anaerobic bacteria such as methane bacteria. Take it apart and
Produces methane (CH4) and carbon dioxide (CO2),
These gases are discharged to the outside of the septic tank (8), and treated water containing ammonia nitrogen (NH, "-N), which is a decomposition product of the nitrogen component of protein and urea, is generated.

Note that the solid matter contained in the treated water that has passed through the downward flow anaerobic hearth (5) settles at the bottom of the first chamber (al).

By performing such anaerobic treatment, organic matter can be effectively removed from the treated water, and as a result, the treated water after anaerobic treatment contains ammonia nitrogen (Nt14"
-N) and a small amount of untreated organic matter is transferred from the first chamber (al) to the second chamber (a2).

That is, the treated water after the anaerobic treatment passes through the first culm pipe (10) and the second advection pipe (11), and enters the downward flow anaerobic hearth (9) in the second chamber (a2). It is directly transferred downward without any anaerobic treatment by the same bed (9).

After that, while passing through the downward flow anaerobic hearth (9) from bottom to top, it undergoes the same anaerobic decomposition as described above, further decomposing organic matter, and then ammonia (8114
The treated water containing a further small amount of untreated organic matter is transferred to the next aerobic treatment chamber (a3) via the third advection pipe (16).

Therefore, in this example, the anaerobic treatment in the second chamber (a2) of the anaerobic treatment chamber (C) is performed by passing the treated water through the upward flow anaerobic hearth (9) from the bottom to the top. By using a downward flow that passes through the anaerobic hearth from the top to the bottom, the flow rate can be lowered, and more undecomposed materials can be transferred to the hearth. anaerobic decomposition can be further promoted.

Therefore, in conjunction with the anaerobic treatment in the first chamber (al),
The anaerobic treatment in the entire anaerobic treatment chamber (C) can be performed efficiently and sufficiently to reduce the generation or residue of undecomposed organic matter as much as possible.

In addition, the acid-producing bacteria and anaerobic bacteria in the above anaerobic treatment are
Although it is possible to wait for the growth of acid-producing bacteria or anaerobic bacteria that have entered the treated water from the environment before using them, it is preferable to inoculate with a proven and excellent starter strain.

In addition, the treated water that has been anaerobically treated in the first chamber (al) of the anaerobic treatment chamber (C) is sent directly to the bottom of the second chamber (a2), and is not sent to the top of the second chamber (a2). In this case, undecomposed substances may accumulate in the upper part of the downward flow anaerobic hearth (9) or in the second chamber (
a2) can be reliably prevented from directly flowing into the aerobic treatment chamber (a3) arranged in parallel with the second chamber (a2).

Next, the purification process in the aerobic treatment chamber (a3) will be explained. In the aerobic treatment chamber (a3), air is blown into the treated water from the aeration pipe (13b) of the aeration device (13). Oxidative decomposition is performed by aerobic bacteria such as nitrifying bacteria that utilize the oxygen in the air, and ammonia nitrogen (Nl14"-N) in the treated water is converted into a nitrate chamber (NO2-
-N) and nitrite nitrogen <NO2-N).

In addition, it is preferable to inoculate aerobic bacteria with proven seed bacteria as described above, and the aerobic hearth (12) can be used to increase the bacterial concentration by attaching such aerobic bacteria and causing the aerobic bacteria to flow out. This is to ensure that there is no decline in

Furthermore, in this example, all of the treated water that has been subjected to the anaerobic treatment and aerobic treatment is subjected to aerobic decomposition treatment in the aerobic treatment chamber (a3) without being directly discharged outside the septic tank (A). A part of the treated water (Q2) is transferred to the air lift pipe (14
) is lifted from below by air from a diffuser pipe (13b) into a water collection basin (40) disposed above the air lift pipe (14), and gas and liquid are separated in the water collection basin (40).
Thereafter, the water is refluxed to the first chamber (al) via the reflux pipe (70).

Therefore, when treated water containing nitrate nitrogen (NOa - -N) and nitrite nitrogen (NO2 - -N) flows into the first chamber (al), the desorbed water present in the first chamber (al) Nitrogen bacteria use the oxygen of these inorganic compounds to decompose organic matter flowing into the first chamber (al) to obtain energy for survival. As a result, inorganic compounds are reduced to molecular nitrogen (N
2) and nitrous oxide (N20), and the organic carbon is decomposed to become carbon dioxide (CO2), which is released outside the septic tank (A).

In this way, the decomposition treatment of organic matter in the first chamber (al) can be carried out not only by anaerobic treatment but also by partially refluxed water from the aerobic treatment chamber (a3) and denitrifying bacteria acting on it6. Therefore, it is possible to suppress the excessive increase in ammonia nitrogen (Nl14''-N) that occurs when performing anaerobic treatment using only anaerobic bacteria (which acts in the direction of suppressing the activity of anaerobic bacteria), and Due to this suppressing effect, the activity of the anaerobic bacteria can be maintained in a suitable state at all times, and the decomposition treatment of organic matter in the anaerobic treatment chamber (C) can be dramatically improved.

Furthermore, by improving the ability to decompose organic matter, it is possible to significantly reduce the amount of untreated organic matter contained in the treated water transferred from the anaerobic treatment chamber (C) to the aerobic treatment chamber (N3). Aerobic treatment room due to untreated organic matter (
The generation of sludge in N3) can also be reduced as much as possible.

On the other hand, nitrate nitrogen (NOa--N) and nitrite nitrogen (NO2-N) in the treated water in the aerobic treatment room (N3)
The concentration of N2 is also reduced by refluxing a portion of the treated water to the anaerobic treatment chamber (C) and converting those ions into molecular nitrogen (N2) by denitrifying bacteria.
) and nitrous oxide (N2Q), so it can be reduced as much as possible.

In this way, the treated water that has undergone aerobic decomposition is separated from the partition wall (3
), flows into the lower part of the sedimentation separation chamber (N4), rises while precipitating extremely small amounts of solid matter remaining in the treated water, flows into the disinfection chamber (18), and enters the chemical cylinder ( 1
8b) The treated water is disinfected and sterilized by the solid disinfectant that gradually flows out from inside, and is then discharged from the outlet (17) to the downstream side of the treated water discharge pipe.

In addition, by making the sedimentation separation chamber (N4) a riser type, sludge brackets are generated and even relatively light specific gravity and small flocs can be collected.
) is steeply sloped downward in the direction of the aerobic treatment chamber (N3), so that the settled sludge in the sedimentation separation chamber (N4) is moved to the bottom of the aerobic treatment chamber (N3). There is.

In this way, the final treated water that is purified from the domestic toilets, kitchens, etc. and discharged to the downstream side of the treated water drainage pipe is stored in the aerobic treatment room (N3). Since a part of the treated water is refluxed, the ROD concentration and nitrogen concentration can be significantly reduced.

According to experiments conducted by the present applicant, the BOD concentration etc. in the final treated water obtained by the septic tank (^) according to this example were as shown in the table below.

Note that the numerical values are expressed as average values.

Unit (II (1/J)) As is clear from the above table, in the case of this example, the BOD concentration etc. can be significantly reduced compared to the conventional septic tank.

In addition, the amount of treated water flowing into the anaerobic treatment chamber (C) is (0
1) If the partial recirculation amount from the aerobic treatment chamber (N3) to the anaerobic treatment chamber tc) is (N2), then the anaerobic treatment chamber (C)
The amount of treated water (N
3) becomes Q3=Q1102, but Ql:Q2=1
:1 to 10 (suitably 1:2 to 6).

By the way, since non-degradable solids such as synthetic fiber fragments, sand grains, and synthetic resin film fragments may be mixed in the initial inflow treated water, it is inevitable that each chamber of the septic tank (a), i.e., Sludge consisting of undecomposed solid matter or the remains of exfoliated bacteria accumulates in the first chamber (al), the second chamber (N2), and the aerobic treatment chamber (N3).

In this case, the first and second manholes (bl
) (b2), and open the first and second advection tubes (10) (11).
By using the passage as a passage, the first chamber (al) and the second chamber (N2)
A vacuum hose can be easily inserted into the bottom of the chamber to suck up solids and sludge, and an aerobic treatment chamber (
By sucking up the solids and sludge in N3), the solids in the sedimentation separation chamber (N4) are also sucked up at the same time. Furthermore, the third manhole (b3) can be opened to easily replace the medicine cartridge (18b).

In addition, surplus sludge adheres to the aerobic P bed (12), but by operating the three-way ball valve (55), the backwash pipe (15)
) and eject air from the ejection pipe (15a),
By manually swinging the ejection pipe (15a) via the flexible vibrator (15C), the excess sludge can be reliably washed away.

(to) Effect According to the present invention, the following effects are produced.

■In the present invention, a part of the treated water that has undergone aerobic treatment is returned to the anaerobic treatment chamber, and the decomposition of organic matter in the anaerobic treatment chamber is performed not only by anaerobic bacteria but also by the aerobic treatment chamber. It can also be carried out using partially refluxed water and denitrifying bacteria acting on it. Therefore, it is possible to suppress the excessive increase in ammonia (NH4) that occurs when performing anaerobic treatment only with anaerobic bacteria (which acts in the direction of RM the activity of anaerobic bacteria), and due to this suppressive effect, Therefore, the activity of the anaerobic bacteria can be maintained in a suitable state at all times, and the decomposition treatment of organic matter in the anaerobic treatment chamber can be dramatically improved.

■By improving the ability to decompose organic matter, the untreated organic matter contained in the treated water transferred from the anaerobic treatment room to the aerobic treatment room can be significantly reduced, and the aerobic The generation of sludge in the treatment chamber can also be prevented as much as possible.

■By improving the ability to decompose organic matter, it is possible to make septic tanks more compact.

(2) By partially refluxing the treated water as described above, the BOD concentration and nitrogen concentration of the final treated water can be significantly reduced, and the purification ability can be improved.

■The water collection basin has an overflow opening to prevent excess treated water from flowing back into the anaerobic treatment chamber and to ensure a constant flow of water, the anaerobic bacteria mentioned above It is possible to reliably prevent inhibition of the activity of nitrogen and improve the nitrogen removal ability.

■Because the treated water is collected in the catch basin and then returned to the anaerobic treatment room, it is possible to reliably separate gas and liquid from the treated water in the catch basin, and to take in air. However, it is possible to prevent the occurrence of a problem in which the activity of anaerobic bacteria in the anaerobic treatment chamber is suppressed by treated water with a large amount of dissolved oxygen.

■Since the treated water is pushed up into the water collection basin by the air lift action of the air lift pipe, there is no need to separately provide a drive source such as a pump for pushing up the treated water, simplifying the structure of the septic tank. This makes it possible to reduce manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of a septic tank equipped with a water collection basin structure according to the present invention. FIG. 2 is a sectional view taken along the line II in FIG. 1. FIG. 3 is a plan view of the septic tank body. FIG. 4 is a plan view of the aerobic treatment chamber. FIG. 5 is a partial front view of the inside of the aerobic treatment chamber. FIG. 6 is a plan view of the air collection umbrella. Figure 7 is a plan view of the water collection basin. Figure 8 is a front view of the water collection basin. FIG. 9 is a partially cutaway enlarged perspective view of the water collection basin. FIG. 10 is a perspective view of a water collection basin as another embodiment. FIG. 11 is a perspective view of a water collection basin as another embodiment. FIG. 12 is an enlarged side view of the reflux pipe. FIG. 13 is a partially cutaway enlarged side view of the reflux treated water collection section. FIG. 14 is a sectional view taken along the line ■-■ in FIG. 13. FIG. 15 is a sectional view of a conventional septic tank. (^) FC) (al) (a2) (a3) (a4) Septic tank Anaerobic treatment room 1st room 2nd room Aerobic treatment room Sedimentation separation room Partition wall 1st advection pipe 2nd advection pipe Air lift pipe Disinfection room Water collection Basin reflux pipe

Claims (1)

[Claims] 1) A diffuser pipe (13b) in the lower part of the aerobic treatment chamber (a3)
An air lift pipe (
The lower end of the air lift pipe (14) is opened, and the lower end of the air lift pipe (14) is opened.
) to the anaerobic treatment chamber (C) via the water collection basin (40).
Connect the air pipe (13c) to the air diffuser pipe (13b).
By supplying air through the air diffuser pipe (13b
) from the air lift pipe (1).
Due to the air lift effect of 4), a part of the treated water undergoing aerobic decomposition treatment in the aerobic treatment chamber (a3) is pushed up into the water collection basin (40), and a certain amount is also lifted from the collection water basin (40). A water collection basin structure in a septic tank configured to allow water to continuously flow back to the anaerobic treatment chamber (C). 2) The water collection basin (40) according to claim 1 is formed into a substantially box shape, and a communication port communicating with the anaerobic treatment chamber (C) is opened in one side wall of the water collection basin (40). An overflow opening (46) is cut out in the other side wall of the water collection basin (40), and the overflow opening (46) is cut out from the bottom of the water collection basin (40).
6) The height to the lower edge of the water collection basin (40) is set higher than the height from the bottom of the water collection basin (40) to the lower edge of the communication port.
A certain amount of the treated water during the aerobic decomposition process is pushed up into the water collection basin (40) through the air lift pipe (14) connected to the bottom of the anaerobic treatment chamber through the communication port. A water collection basin structure in a septic tank that allows water to flow back to (C).