JPH02222791A - Septic tank which can adjust reflux rate from aerobic treatment chamber to anaerobic treatment chamber - Google Patents

Abstract

PURPOSE:To maintain the cleaning capacity of a septic tank in an optimum state at all times by constituting the septic tank in such a manner that the treated water in an aerobic treatment chamber can be partly returned and the rate of the partial reflux of aerobically treated water can be finely adjusted. CONSTITUTION:A variable flow rate pump 89 which is driven continuously by a stepping motor M is mounted to the intermediate point of a return pipe 14b. The motor M and a pump device P are connected to a control device 79. On the other hand, various kinds of environmental condition detecting sensors, such as an atmosphere sensor 80 provided near the septic tank, a water temp. sensor 81 provided in a septic tank body a, a nitrate and nitrite ion sensor 84, ammonia sensors 85, 86, and pH sensors 87, 88, are connected to the control device 79. The rotating speed of the motor M is changed continuously by changing the number of the pulse voltages to be sent to the motor M of the pump 89 in accordance with the detection outputs from various kinds of the above-mentioned environmental condition detecting sensors, by which the reflux rate of the aerobically treated water is automatically and finely adjusted, by which the cleaning capacity of the septic tank A is maintained in the optimum state at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a septic tank capable of adjusting the amount of return from an aerobic treatment chamber to an anaerobic treatment chamber.

(b) Conventional technology Traditionally, as a form of septic tank, Utility Model 6″3-4589
There is one listed in No. 4.

That is, as shown in FIG. 8, the septic tank has a first anaerobic treatment chamber 91 into which sewage flows into the septic tank main body 90, and a 1η water treated anaerobically in the first anaerobic treatment chamber 91. The second anaerobic treatment chamber 92 into which it flows, and the second anaerobic treatment chamber 92
An aerobic treatment chamber 93 into which the anaerobically treated wastewater flows, a sedimentation separation chamber 94 into which the aerobically treated wastewater flows in the aerobic treatment chamber 93, and a supernatant liquid separated in the sedimentation separation chamber 94. and a disinfection chamber 95 into which the water flows.

Further, aerobic treatment in the aerobic treatment chamber 93 is performed by blowing air into the aerobic filter bed 96 from an aeration device 97.

According to this septic tank, the first anaerobic treatment chamber 91
It is considered that anaerobic treatment can be performed in two stages in the first and second pneumatic treatment chambers 92, and then aerobic treatment can be performed to obtain clean treated water.

In addition, as a form of septic tank, the present applicant previously filed a patent application in 1983.
There is one disclosed in No. 2-214009.

The septic tank also adjusts the pH of the anaerobic treatment room without using supplementary materials for pH adjustment by returning a portion of the acidic aerobic treated water to the alkaline aerobic decomposition treated water. be able to.

(c) Problems to be Solved by the Invention However, such septic tanks still have the following problems to be solved.

That is, the present applicant conducted research on the relationship between the purifying ability of a domestic or personal septic tank and various environmental factors related to the septic tank.

As a result of this research, the temperature of the treated water in the septic tank,
Atmospheric temperature around the septic tank, inflow load to the septic tank (amount, i
t), the amount of dissolved oxygen, the value of ammonia ions, etc. in the treated water fluctuate considerably, and the purification ability also fluctuates considerably due to this fluctuation.

However, the conventional septic tank described above is configured to always supply a constant amount of aerobically treated water from the aerobic treatment chamber to the anaerobic treatment chamber despite fluctuations in the environmental conditions of the septic tank. pHtll in the anaerobic treatment room
Therefore, it was not possible to effectively deal with the decrease in purification ability.

An object of the present invention is to provide a septic tank structure that can always maintain the purification capacity of the septic tank in an optimal state regardless of changes in various environmental conditions related to the septic tank.

(d) Means for Solving the Problems The present invention includes arranging an anaerobic treatment chamber and an aerobic treatment chamber in parallel within the septic tank main body, and arranging an aeration device in the aerobic treatment chamber. A transportation system from an aerobic treatment chamber to an anaerobic treatment chamber, characterized in that a part of the treated water in the aerobic treatment chamber can be returned, and a part of the flow rate of the aerobic treated water can be adjusted. This relates to a septic tank that can be adjusted.

In addition, the present invention provides a septic tank configuration that allows fine adjustment of the partial return amount of aerobic treated water in response to changes in the temperature of the treated water in the septic tank, the ambient temperature around the septic tank, and changes in the inflow load to the septic tank. It also has characteristics.

(e) Examples Hereinafter, the present invention will be specifically explained based on examples shown in the accompanying drawings.

In Figures 1 and 2, A indicates a domestic septic tank, and the septic tank A is composed of a septic tank body a and a lid, and is a pipe for discharging sewage from household toilets, kitchens, etc. It is placed in the middle of the road.

As shown in FIGS. 1 to 3, the septic tank main body a has a box-like shape with an open top.

By erecting partition walls 1.2.3 at regular intervals in the longitudinal direction, the internal space is divided into a first chamber a1 and a second chamber a□ forming an anaerobic treatment chamber C. , an aerobic treatment room and a sedimentation separation room a with a disinfection room 18 inside.
It is divided into 4 parts.

Hereinafter, the configuration of each chamber will be explained in order starting from the configuration of the anaerobic treatment chamber C. As shown in FIG.
The first chamber a1 communicates with the downstream side of the sewage discharge pipe through an inlet 4 having a substantially horizontal cross-section shape, and the sewage flowing into the first chamber at from the sewage discharge pipe (hereinafter referred to as "Treated water"
) can be allowed to flow in while being bent downward.

Further, a baffle plate 25 is provided directly below the inlet 4 and is tilted downward toward the second chamber 82 to prevent wastewater flowing into the first chamber a1 from the inlet 4. It is made to fall into the center of the downward flow anaerobic filter bed 5, which will be described later, along the intermediate part [temporary 25]. Note that 26 is a baffle plate stay for attaching the baffle plate 25 to the septic tank main body a.

In addition, as shown in FIG. 1, the first chamber a of the expiratory treatment chamber C
, a downward flow anaerobic filter bed 5 is disposed in the center at a predetermined distance downward from the inlet 4.

The downward flow anaerobic filter bed 5 is provided with upper and lower filter media in the form of a lattice, respectively, on supports 6.6'' that are fixed to the side surfaces of the septic tank main body a and the partition wall l on the 1va+ side with an interval in the vertical direction. !17.7' is stretched and supported, and the upper and lower filter media shelves 7.7'
It is constructed by filling a desired filter medium with anaerobic bacteria attached therebetween.

As the filter medium, a filter medium formed from a synthetic resin or other material formed to significantly increase the surface area and porosity can be used.

As shown in FIG. 1, a first chamber a is inserted through a partition wall 1.

A second chamber Mg arranged in parallel with the chamber accommodates an upflow anaerobic filter bed 9 therein.

This upflow anaerobic filter bed 9 has a structure similar to the above-mentioned downflow anaerobic filter bed 5, but has the first advantage in that the porosity between the filter media is made smaller and the surface area is made larger. room a1
This is different from the downward flow linear aeration filter bed 5 disposed inside.

Note that, like the downward flow anaerobic filter bed 5, the upward flow anaerobic filter bed 9 also includes the upper and lower filter media J18.8' and the support 8a,
8b, it is disposed in a fixed state at the center of the second chamber a1.

Next, from the first chamber a1 to the second chamber a! To explain the treated water transfer structure for transferring treated water, as shown in FIGS. The lower part of the partition wall L is completely partitioned, and the advection of the treated water from the first chamber a1 to the second chamber is controlled by the walls installed along the sides of the first chamber 81 side and the second chamber ag side of the partition l, respectively. First and second advection tubes 10.1
It will be held throughout the year.

The first and second advection pipes 10.11 are as shown in FIG.
L-shaped plates 10a and 11a are each formed in an abbreviated shape in cross section, and L-shaped plates 10a and 11a are arranged at symmetrical positions across the partition wall L, and one edge of the same-shaped plates Oa and lla is placed on the side surface of the partition wall position. By bringing them into close contact and bringing the other edge into close contact with the inner surface of the side wall 20 of the septic tank main body a, a tube body is formed whose upper and lower ends are open above and below each filter bed 5.9.

In addition, in the partition wall 1 between the advection pipes 10 and 11, there is provided a substantially rectangular communication port 21 that reaches a position slightly lower than the treated water level from above.
It is possible to transfer the treated water from the first advection pipe 10 in the first chamber a to the second advection pipe 11 in the second chamber.

The first and second advection pipes 10.11 are disposed on the left and right sides of the partition wall so as to be equidistant from the inlet 4, and the first chamber a and the first chamber a and the second chamber 10. 2 rooms al
A pair of communication ports 21 are also provided on the left and right sides, and a movable weir 30 is attached to each communication port 21 so as to be slidable in the vertical direction.

Furthermore, the above-mentioned treated water transfer structure will be explained in detail with reference to FIG.
The inlet 10a is opened at the bottom of the first chamber a, and the outlet toh
is opened at the upper part of the first chamber n at a level between the treated water level and the road.

Therefore, the treated water that has been anaerobically treated through the downward flow anaerobic filter bed 5 is transferred upward through the first advection pipe IO and directly flows into the second advection pipe U.

On the other hand, as shown in FIG. 1, the second type flow pipe 11 extends downward through the upflow anaerobic filter bed 9, and connects its inlet 10a to the second chamber a! The upper part of the chamber is connected to the outlet tab of the first advection tube 10, and the outlet 11a thereof is opened to the bottom of the second chamber a.

Therefore, the treated water that has been anaerobically treated through the downward flow anaerobic filter bed 5 is transferred to the downward flow anaerobic filter bed 5 and the upward flow anaerobic filter bed 9.
It flows directly into the bottom of the second chamber at through the first advection pipe lO and the second advection pipe 11 without being subjected to anaerobic treatment.

The inflowing treated water then flows upward through the upward flow anaerobic filter bed 9 to be subjected to the second anaerobic treatment, and then flows into the aerobic treatment chamber aj described below. It turns out.

In the above configuration, the configuration of the movable weir 30 provided in the communication port 21 forming the connection between the first advection pipe IO and the second advection pipe 11 will be briefly described as shown in FIGS. 2 and 3.
As shown in the figure, the movable weir 30 is formed into a rectangular plate shape slightly wider than the width of the communication port 21, and has a sawtooth upper edge 30a, and has a side wall of the septic tank main body a adjacent to the partition l. Guide rails 31 and 31 provided on the inner surface of the second advection tube 11 and the inner surface of the side wall of the second advection tube 11 facing the same inner surface, respectively.
It fits into the inside so that it can slide up and down.

In addition, a tension bolt sliding groove 32 is formed in the center of the movable weir 30 in a vertically elongated manner from the lower end to the center, and the slide tension bolt 33 is inserted into the partition wall 1 through the sliding groove 32. A nut 34 with a tension knob is screwed onto the tip of the adjustment bolt 33 so that the tightening can be adjusted freely, and the adjustable weir 30 is slid and fixed up and down by the tightening adjustment part of the nut 34.
The vertical position can be adjusted. Note that 35 is a fixed plate.

Therefore, when installing the septic tank A, if the septic tank A is installed tilted left and right with respect to the vertical direction, the left and right movable weirs 30 and 30 must be adjusted by sliding in the vertical direction. By this, the first chamber a, the second chamber a
□Movable weir 30.30 through each communication port 21.21
It is possible to make the droplets of wastewater flowing overflow uniform, and it is possible to ensure good purification processing efficiency.

Next, the configuration of the aerobic treatment chamber a will be explained.

First, referring to FIG. 1, the configuration for transferring treated water from the eight second chambers of the sickle aerobic treatment chamber C to the aerobic treatment chamber a will be described.The second chamber ai and the aerobic treatment chamber a.

The partition wall 2 in between completely partitions the area below the treated water level of the septic tank main body a, and the advection of the treated water from the second chamber a2 to the aerobic treatment chamber a is carried out through the second chamber a of the partition wall 2. .

This is done by a third advection pipe 16 provided on the side surface.

The third advection pipe 16 is formed into a substantially U-shaped cross section with upper and lower ends open, 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 at side, and the lower end is formed into an upward flow anaerobic tube. A substantially rectangular advection port 16 is formed in the partition wall 2 to form a pipe body of a third advection pipe 16 that opens above the filter bed 9 and whose upper end opens above the treated water level.
A is opened and the second chamber a2 and aerobic treatment chamber a are connected to each chamber 11.
It is connected at the top of 2+83.

Next, the internal structure of the aerobic treatment chamber a3 will be described with reference to FIGS. 1, 3, and 4.

As shown in FIG. 1, the aerobic treatment chamber a includes an aerobic filter bed 12, a bullet device 13, and an air lift pipe 1.
4 and a backwash pipe 15 are built in.

(The air lift pipe 14 constitutes a part of the partially treated water recirculation structure R described later, so it will be explained in the explanation of the structure E.) First, the aerobic filter bed 12 will be explained. , the aerobic filter bed 12 is for performing aerobic treatment in cooperation with the bullet device ot3, and in this embodiment, as shown in FIG. A large number of string-like filter media 12b formed by attaching a large number of fibrous seed yarns in a substantially tuft shape to a central string are supported on the frame body 12a, which is deposited at a predetermined interval from the center string.
It is constructed by attaching aerobic bacteria to the string-like filter medium 12b.

In addition, as a filter medium of the aerobic filter bed 12, a string-like filter medium 12b
In addition, other shapes such as corrugated or honeycomb filter media can also be used.

Next, the bullet device 13 will be explained with reference to FIGS. 1 and 4. The second chamber afi and the aerobic treatment chamber a.

A pair of air diffuser pipes 13b, 13b extend along the bottom surface of the septic tank main body a in the left and right width directions from the lower end of the vertical air pipe 13a vertically installed along the partition wall 2 between the two.
b, 13b is formed from a fully porous tube having a large number of air ejection holes 13t1.

Depending on the configuration, the air vertical pipe 13a and the air diffuser pipe 1:
3h, air can be diffused into the aerobic treatment chamber a through t3b, and the activity of aerobic bacteria can be maintained.

Further, as shown in FIG. 4, in the middle of the air pipe 13c, there is an air amount adjustment section 50 consisting of a manual flow rate adjustment valve for adjusting the aeration amount of air supplied to the aeration pipe 13b, A three-way ball valve 55 is provided that can switch the flow and supply air from the diffuser pipe 13b to the backwash pipe 15, which will be described later.

In addition, as shown in FIG. 1, convection guide plates 60 and 61 are arranged directly above the left and right air diffusers 13b and near the treated water level, respectively.
．． 61 has its lower end fixed to the partition wall 2 by support members 62 and 63, and its middle part is curved upward in a convex shape so that its upper end is close to the treated water level.

Therefore, the convection of the treated water in the aerobic treatment chamber a by the air ejected from the aeration pipes 13b, 13b can be promoted 7, and the supply of air to the aerobic bacteria can be promoted.

Moreover, a certain gap S, S is formed between the lower end of each convection guide plate 60.61 and the partition wall 2, so that solids in the treated water remain on each convection guide plate 60.61. This prevents problems such as spoilage.

Next, the backwash pipe 15 will be explained.
is for periodically removing excess sludge adhering to the string-like filter medium 12b in the aerobic filter bed 12 to maintain the activity of aerobic bacteria.

As shown in FIGS. 1 and 4, the backwash pipe 15 has a backwash vertical pipe 15b vertically installed along the partition wall 3 between the aerobic treatment chamber a and the sedimentation separation chamber 84, and has a vertical backwash pipe 15b at its lower end. , one end of an air jet pipe 15a disposed approximately horizontally below the aerobic filter bed 12 is connected for communication, while the upper end of the above-mentioned backwash vertical pipe 15b is connected,
Possible [the above-mentioned air pipe 13c via the emitting pipe 15c,
The structure is constructed by supporting and communicating with each other in a cantilevered manner.

Next, a part of the treated water reflux structure in which a part of the treated water in the aerobic treatment chamber a is refluxed to the first chamber a1 of the anaerobic treatment chamber C will be described.

As shown in FIG. 1, in the aerobic treatment chamber, an air lift pipe 14 is disposed vertically along the partition wall 2.

As shown in FIGS. 1 and 5, the air lift pipe 14 has its lower end opened above one of the air diffuser pipes 13b, and its upper end is connected to a water collecting pipe located slightly above the treated water level. It penetrates the bottom of the cell 14a and opens slightly above the bottom.

On the other hand, the water collection basin 14a has a return pipe 1 passing through the partition wall 2.
The other end of the pipe 14b is extended to the upper part of the first chamber a, and the tip of the other end is bent downward to open below the level of the treated water. There is.

With this configuration, a part of the treated water in the aerobic treatment chamber a can be returned to the first chamber al of the anaerobic treatment chamber C by using the air blown out from the air lift pipe 14.

Moreover, as shown in FIG. 1, the second chamber a! A cutout opening t4r for cleaning the inside of the pipe and a return treated water recovery section 40 for measuring the amount of returned treated water are provided in the middle of the return pipe 14b located above.

Further, as shown in FIG. 6, the water collection basin 14a is formed into a substantially box shape with an open top surface, and is attached to the upper part of the partition wall 2 in a cantilever state so that the vertical sliding position can be adjusted freely. When viewed from above, the partition plate 14c is provided on the diagonal line, and the partition plate 1
A substantially rectangular water passage hole 14d is opened in the lower part of the partition plate 4c, and the upper end of the air lift pipe 14 is opened in an example of the partition plate 14c.
The other side is communicated with the return pipe 14h.

Furthermore, a substantially rectangular overflow opening 14e is cut out from above in one side of the water collection basin 14a, and a triangular weir 14g for communicating with the return pipe 14b is cut out in the other side. .

In addition, from the aerobic treatment chamber a3 to the first chamber a of the pigeon aerobic treatment chamber C
As shown in FIG. 6, the amount of returned wastewater returned to the tank 1 can be adjusted by adjusting the vertical sliding position of a water collection basin 148 connected to the air lift pipe 14.

In FIG. 6, reference numeral 14b indicates an elongated slide hole, 14 a mounting bolt, and 143 a tightening adjustment nut.

In the above configuration, the water collection basin 14a has an open top, but it can also be covered with a lid.

Next, the configuration of the sedimentation separation chamber a4, which is arranged in parallel with the aerobic treatment chamber a through the partition wall 3, will be explained.

As shown in FIGS. 1 and 3, a precipitation separation chamber a.

is formed between the partition wall 3 and the partition wall 22 of the disinfection chamber 18, and is provided for settling sludge contained in the final treated water that has been aerobically treated in the aerobic treatment chamber a.

As shown in the figure, the bottom of the sedimentation separation chamber a4 is connected to the bottom of the aerobic treatment chamber a through a communication path n provided at the bottom of the partition wall 3, and the aerobically treated treated water is , will flow into the sedimentation separation chamber 84 through the communication passageway.

Next, with reference to FIG. 1, the configuration of the disinfection chamber 18 provided within the sedimentation separation chamber a will be described.

The disinfection chamber 18 is disposed above the sedimentation separation chamber a by a partition wall 22, and has a generally box-like shape with an open top and separated from the sedimentation separation chamber a.

Further, the disinfection chamber 18 has its -side surface brought into close contact with the inner surface of the side wall of the septic tank main body a, and communicates with the discharge port 17 protruding from the rear wall of the septic tank a, and also has an upper edge 18c of the disinfection chamber 1B.
is set slightly lower than the treated water level.

Further, at a position slightly lower than the treated water level h' on the inner surface of the disinfection chamber 18, a drug section support 18a is provided protruding from the side wall of the disinfection chamber 18, and the support 18a allows the solid disinfectant to be inserted from above. The lower end of the drug barrel 18b filled with the drug is supported while being in contact with the treated water advected from the settling chamber R4.

To explain the other configuration of the sedimentation separation chamber a, in FIG. 1, reference numeral 19 designates scum outflow prevention plates protruding vertically from the partition wall 3 to the left and right sides of the sterilization chamber 18, respectively.

This scum outflow prevention plate 19 has its side surface in close contact with the disinfection chamber 18, its upper edge protruding above the treated water level, and its lower edge immersed below the treated water level, so that the scum floating on the treated water surface is settled. Scum floating on the surface of the treated water in the separation chamber a is prevented from advecting from the sedimentation separation chamber a to the disinfection chamber 18.

Further, a communication path n formed between the lower edge of the partition wall 3 between the sedimentation separation chamber a4 and the aerobic treatment chamber a is provided with a predetermined distance from the inner bottom surface of the septic tank body a. In addition, the sedimentation separation chamber a has an inner bottom surface forming the communication passage n steeply inclined downward in the direction of the aerobic treatment chamber a, and the aerobic treatment chamber a1 for the aerobically treated treated water. to the sedimentation separation chamber a4, and in the sedimentation separation chamber a,
It is designed to promote the settling of sludge.

Next, the structure of the lid placed on the upper part of the septic tank main body a will be explained.

As shown in Figures 1 and 2, the lid body is fixed to a flange a fixed to the upper edge of the septic tank body a via bolts (not shown) or adhesively bonded with synthetic resin. are used to close the upper opening of the septic tank main body a, and have large-diameter first and second manholes h located above the partition wall l of the septic tank main body a and above the aerobic treatment chamber a. A third manhole b with a small diameter is provided in a position above the medicine cylinder 18b so as to be openable and closable.

It can be opened and closed freely.

In the structure of the septic tank A, the present invention further provides for the treatment water in the septic tank main body a to be improved by finely adjusting the amount of partial return of the aerobic treated water from the aerobic treatment chamber a to the anaerobic treatment chamber C. water temperature, atmospheric temperature around the septic tank body (air temperature)
, is characterized by a configuration that allows the purification capacity of the septic tank A to be always maintained at an optimum state regardless of fluctuations in the inflow load (!t1, quality) into the septic tank body a.

In this example, we focused on the environmental conditions shown in the table below,
The amount of partial recirculation of the aerobic treated water from the aerobic treatment chambers A and C to the anaerobic treatment chamber C will be finely adjusted.

In the table above, "change" refers to a change in each environmental condition listed in the "Environmental conditions"section; ↑ indicates that each value has increased, and ↓ indicates that each value has decreased. show.

Further, in the environmental conditions, (favorable) indicates aerobic treatment chamber a, and (unfavorable) indicates anaerobic treatment chamber C.

On the other hand, ↑ and ↓ in “Treatment water transport agitation” are, respectively,
Indicates the method to be taken when environmental conditions change as shown in the table.

That is, when the air temperature or water temperature decreases, an operation is performed to partially reduce the amount of recirculation of the aerobically treated water. In addition, aerobic treatment room a
If the ammonia ion concentration in , increases,
Perform an operation to partially reduce the amount of reflux of aerobically treated water.

On the other hand, in this embodiment, the partial return amount of the aerobic treatment chamber can be increased or decreased by manually adjusting the vertical position of the water collection basin 14a according to the rate of change in environmental conditions, as shown in FIG. This is done by fine-tuning.

Thereby, the purification capacity of the septic tank can be maintained at an optimal state at all times.

Note that known devices and methods can be used to measure the values of the above environmental conditions. For example, in the measurement of ammonia ions, a potentiometer, an ion electrode, a reference electrode, a sample container, a magnetinox cooler, and a temperature An ion polarity device consisting of a pl+
For the measurement, the one described in JIS Z 8802 can be used.

Further, FIG. 6 shows the structure of a purification IA that can automatically adjust the amount of aeration and the amount of partial recirculation of aerobically treated water.

That is, in FIG. 6, in the middle of the return vibrator 14b,
A variable flow rate pump 89 that is driven steplessly by a stepping motor M is attached.

Further, a stepping motor M of the variable flow pump 89,
The pump device P is connected to a control device 79, while
The control device fff79 includes an atmospheric temperature sensor 80 installed near the septic tank and a water temperature sensor 8 installed inside the septic tank body a.
1, various environmental condition detection sensors such as a nitric acid/nitrite ion sensor 84, an ammonia ion sensor 85, 86, and pH sensors 81 and 88 are connected.

And each fI above! By changing the number of pulse voltages sent to the stepping motor M of the variable flow rate pump 89 based on the detection output from the environmental condition detection sensor, the rotation speed of the stepping motor M is changed steplessly, and the aerobically treated water is The reflux amount can be automatically fine-tuned.

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.

From the upstream side of the sewage discharge pipe through the inlet 4 to the first chamber a
The treated water flowing into the , and the organic matter contained in the treated water (components include water, carbohydrates, proteins, lipids, urea, etc.) pass through the downward flow anaerobic filter bed 5. It undergoes anaerobic decomposition by anaerobic bacteria adhering to the surface of the filter medium on the bed 5.

That is, first, the organic matter in the treated water is reduced to a low molecular weight by acid-producing bacteria and converted into acetic acid (CII3COOII) and propionic acid (
CIlsCLCOOII), etc., and then
Anaerobic bacteria such as methane bacteria decompose the acetic acid to produce methane (CI+4) and carbon dioxide (Cot>).
These gases are released outside of the septic tank A, and ammonia nitrogen (Nl), which is a decomposition product of the nitrogen component of protein and urea, is
The treated water containing 14°-N) is chemically converted.

Incidentally, coarse solids contained in the treated water that has passed through the downward flow anaerobic filter bed 5 settle at the bottom of the first chamber 81 .

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 (Nll+
N) and a small amount of untreated organic matter in the first chamber a.
1 to 2nd room a! will be transferred to.

That is, the treated water after the anaerobic treatment passes through the first advection pipe 10 and the second advection pipe 11, and is transferred to the lower part of the downward flow anaerobic filter bed 9 of the second chamber a2 by the f1 bed 9. Directly transported without anaerobic treatment.

After that, while passing through the upflow anaerobic filter bed 9 from below, it undergoes the same anaerobic decomposition as described above, further decomposing organic matter, and then ammonia nitrogen (Ni
1. The treated water containing a small amount of untreated organic matter is transferred to the next aerobic treatment chamber a,
It is transferred via the advection pipe 16.

Therefore, in this embodiment, the second chamber a7 of the anaerobic treatment chamber C
The treated water is subjected to anaerobic treatment in an upflow anaerobic filter bed 9.
By creating an upward flow that passes through the anaerobic filter bed from the bottom to the top, the flow rate can be made slower than when creating a downward flow that passes through the anaerobic filter bed from the top to the bottom. More undecomposed substances can be anchored in the filter bed, and anaerobic decomposition can be further promoted.

Therefore, in addition to the anaerobic treatment in the first chamber a, the anaerobic treatment in the entire aerobic 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 and then use them, it is preferable to inoculate with proven seed bacteria.

In addition, the treated water that has been anaerobically treated in the iva+ of the anaerobic treatment chamber C is directly sent to the bottom of the second chamber a.
! Since the undecomposed substances are not sent to the upper part of the upflow anaerobic filter bed 9, the undecomposed substances may remain in the upper part of the upflow anaerobic filter bed 9, and the Al
It is possible to reliably prevent the water from flowing directly into the aerobic treatment chamber a, which is arranged in parallel with the aerobic treatment chamber a.

Next, to explain the purification process in the aerobic treatment chamber a, inside the aerobic treatment chamber a, the aeration bag 'I! ,1
Air is blown into the treated water from the aeration pipe 13b of No. 3, and aerobic bacteria such as nitrifying bacteria use the oxygen in the air to oxidize and decompose the treated water. .°=N) is nitrate faa nitrogen (110,--N
) and nitrite nitrogen (NOx--N).

As for aerobic bacteria, it is preferable to inoculate proven seed bacteria as described above, and by attaching such aerobic bacteria to the aerobic filter bed 12, the aerobic bacteria will flow out and the bacterial concentration will decrease. I try not to have anything to do.

Furthermore, in this example, all of the treated water that has been subjected to the anaerobic treatment and aerobic treatment is not discharged as it is outside the septic tank A, but the treated water that is undergoing aerobic decomposition treatment in the aerobic treatment chamber a. Blow part 0 into the air lift pipe 14 from below.
The air from the diffuser pipe 13b that is filled with Δ is lifted to the water collection tank 14a disposed above the air lift pipe 14, air and water are separated in the water collection tank 14a, and then the air is returned to the first chamber a1 via the return vibe 14c. I am planning to send it back to .

Therefore, when treated water containing nitrate nitrogen (No, --N) and nitrite nitrogen (Not-N) flows into the first chamber at, the denitrifying bacteria present in the first chamber a, Utilizing the oxygen of these inorganic compounds, the organic matter flowing into the first chamber a1 is decomposed to obtain energy for survival.

As a result, inorganic compounds are reduced to molecular nitrogen (Nt
) and nitrous oxide (lho), and the organic carbon is decomposed to become carbon dioxide (Cok), which is released outside of the septic tank A.

In this way, the decomposition treatment of the Vs-containing substances in the first chamber a1 can be performed not only by anaerobic treatment but also by the partial return water from the aerobic treatment chamber a3 and the denitrifying bacteria acting on it.

Therefore, it is possible to suppress the increase in ammonia nitrogen (NH, "-N) as a precipitate (which acts in the direction of suppressing the activity of anaerobic bacteria) that occurs when performing anaerobic treatment only with anaerobic bacteria, Further, 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.

In addition, 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 A. The generation of sludge in the aerobic treatment chamber a caused by this can also be reduced as much as possible.

On the other hand, the concentration of nitrate nitrogen (N(h--N) and nitrite nitrogen (NOZ--N) in the treated water in the aerobic treatment room a also decreases when some of the treated water is transferred to the anaerobic treatment room C. By refluxing, these ions can be decomposed into molecular nitrogen (N2) and nitrous oxide (N!0) by denitrifying bacteria, so they can be reduced as much as possible.

In this way, the treated water that has undergone aerobic decomposition bypasses the lower part of the partition wall 3, flows into the lower part of the settling chamber a, and rises while precipitating extremely small amounts of solids remaining in the treated water. The solid disinfectant flows into the disinfection chamber 18 and is disinfected and sterilized by the solid disinfectant that gradually flows out from the drug cylinder tab.
7 to the downstream side of the treated water discharge pipe.

In addition, by making the sedimentation separation chamber a of the upflow type, a sludge blanket is generated and even small flocs with relatively light specific gravity can be collected.Furthermore, the inner bottom surface of the sedimentation separation chamber a4 is subjected to aerobic treatment. The sedimentation IQ?T'z mud in the sedimentation separation chamber a4 is moved to the bottom of the aerobic treatment chamber ai by descending (φ) in the direction of chamber a.

In this way, the final treated water that is purified from the toilets, kitchens, etc. of the home and discharged to the downstream side of the treated water drainage pipe is processed in the aerobic treatment room a. Since a part of the 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 A according to this example were as shown in the table below.

Note that the numerical values are expressed as average values.

Unit (pan g/2) 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.

Also, calculate the amount of wastewater flowing into the anaerobic treatment chamber C.

If the partial recirculation rate from the aerobic treatment chamber a to the anaerobic treatment chamber C is 6, then the cap of the treated water transferred from the anaerobic treatment chamber C to the aerobic treatment chamber a is To= Q+10 Gy, but L: Qt=1: 1 to 10 (12 to 6 for maximum)
It was found that it is preferable to

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, that is, the first In chamber al+second chamber al, aerobic treatment chamber a, sludge consisting of undecomposed solid matter or remains of #J# bacteria is deposited.

In this case, the first part of the lid. 2nd manhole b1゜b□
By opening the chamber and using the first and second advection pipes 10.11 as passages, it is possible to easily attach a Baquième hose to the bottom of the first chamber a and the second chamber a to remove solids and sludge. In addition, by sucking up the solid matter and sludge in the aerobic treatment chamber a, the solid matter in the sedimentation separation chamber a4 is also sucked up at the same time. Also, open the third manhole b3 and open the medicine cylinder 18.
b can be easily replaced.

In addition, surplus sludge adheres to the aerobic filter bed 12, but by operating the three-way ball pulp 55, the ejection pipe 1 of the backwash pipe 15
While blowing out air from 5a, the flexible vibrator 15
The excess sludge can be reliably washed away by manually moving the ejection pipe 15a in tz via c.

Furthermore, as mentioned above, in this embodiment, the aeration device 13
By finely adjusting the amount of aeration ejected from the septic tank body A and the amount of aerobic treated water returned to the aerobic treatment chamber C,
The purification capacity of the septic tank A is always maintained at its optimum state regardless of fluctuations in the temperature of the treated water in the septic tank A, the ambient temperature (air/M) around the septic tank body 3, or the inflow load (quantity, quality) into the septic tank body a. can be maintained.

Further, FIG. 7 shows another embodiment of the septic tank A according to the present invention.

As shown in the figure, this embodiment has almost the same configuration as the embodiment described above, except that the flow of the treated water in the second chamber a2 of the anaerobic treatment room water is changed to the downward flow of the embodiment described above. It is characterized by a downward flow configuration.

That is, in this embodiment, the upper end of the first advection pipe 10 in the first chamber a opens directly into the upper part of the second chamber a,
Further, the bottom of the second chamber afi communicates with the upper part of the aerobic treatment chamber a via the second advection pipe 70.

In this embodiment as well, some of the aerobically treated water is sent to the aerobic treatment chamber C! By finely adjusting +1, the septic tank can be maintained regardless of fluctuations in the temperature of the treated water in the septic tank body a, the ambient temperature (air temperature) around the septic tank body 3, and the inflow load (N, quality) into the septic tank body a. The purification ability of A can be maintained at an optimal state at all times.

(f) Effects As explained above, the present invention has the following effects.

That is, by finely adjusting the amount of aeration diffused into the aerobic treatment chamber and the amount of aerobic treated water partially returned from the aerobic treatment chamber to the anaerobic treatment chamber, the treatment inside the septic tank and main body a can be improved. Water temperature, atmospheric temperature (air temperature) around the 3 main parts of the septic tank
The purification capacity of the septic tank can be maintained at an optimal state at all times, regardless of fluctuations in environmental conditions such as the inflow load (quantity, quality) into the septic tank main body a.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional side view of the septic tank according to the present invention, Fig. 2 is a sectional view taken along line 1-1 in Fig. 1, Fig. 3 is a plan view of the septic tank body, and Fig. 4 is a plan view of the aerobic treatment chamber. Figure 5 is a perspective view of a water collection basin, Figure 6 is an explanatory diagram of the conceptual structure of a septic tank that can control the return amount of aerobically treated water, and Figure 7 is an explanatory diagram of another embodiment. FIG. 8 is an explanatory diagram of the conceptual structure of a conventional septic tank. In the figure, A: Septic tank C: Anaerobic treatment chamber a, : First chamber a2: Second chamber a, : Aerobic treatment chamber a, : Sedimentation separation chamber l: Partition wall 14b: Return pipe 50; Air flow rate adjustment section

Claims (1)

[Claims] 1. An anaerobic treatment chamber (C) and an aerobic treatment chamber (a_3) are arranged side by side in the septic tank body (a), and aeration is carried out in the aerobic treatment chamber (a_3). Along with arranging the device (13),
From the aerobic treatment chamber to the anaerobic treatment chamber, it is possible to partially recirculate the treated water in the aerobic treatment chamber (a_3), and to finely adjust the amount of the partially recirculated treated water. A septic tank with adjustable reflux amount. 2. The method according to claim 1, wherein the amount of partially recycled treated water is finely adjusted according to changes in the temperature of the treated water in the septic tank, the ambient temperature around the septic tank, and the inflow load to the septic tank. A septic tank that can adjust the flow rate from the aerobic treatment room to the anaerobic treatment room.