JPH1119668A - Small-sized combined purifying tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized combined purifying tank capable of preventing sludge from being excessively drawn and also capable of preventing the sludge from flowing out in the case where a large quantity of water flows rapidly. SOLUTION: The inside of an aeration tank 51 is divided into a first chamber 51a and a second chamber 51b by a partition plate 52 low in height and a screen 53 and a membrane module 57 is arranged in the second chamber 51. A manhole 75 is provided on the upward of the first chamber 51a. A presettling tank 66 is provided so as to be separated by the partition plate 65 and the water flowing over an upper limit water level H.H.W.L. is made so as to flow out to the pre-settling tank 66. The water in the pre-settling tank 66 overflows a tank wall 70, flows into a pre-disinfecting tank 71, after being sterilized by coming to contact with a sterilizing agent, the water overflows the tank wall 70 and flows into a disinfecting tank 62 to be discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized combined septic tank for purifying domestic wastewater and the like.

[0002]

2. Description of the Related Art As disclosed in JP-A-7-299490 and JP-A-7-299491, an apparatus for treating domestic wastewater and the like is provided with an aeration treatment after subjecting water to be treated to screen filtration, followed by aeration treatment. After being filtered through a filtration membrane, those that are sterilized and discharged are widely used.

FIGS. 3 and 4 show the above-mentioned Japanese Patent Application Laid-Open No. 7-29949.
FIG. 3 shows a conventional example, in which a sewage treatment apparatus 1 shown in FIG. 3 biologically converts treated water introduced from a treated water supply pipe 2 by activated sludge under aerobic conditions. It comprises an aeration chamber 3 to be treated, and a filtrate chamber 5 separated from the aeration chamber 3 via a partition 4, and the filtrate chamber 5 is provided with a discharge pipe 6.

In the aeration chamber 3, a filtration unit 8 provided with a screen 7 and the like is provided so as to cover the opening of the water supply pipe 2 to be treated, and the liquid level of the activated sludge mixed liquid in the room is measured at the upper part. The liquid level gauge 9 is connected to a control device 9a having a timer function. In addition, an immersion type membrane separation device 10 is provided in the vicinity of the partition 4 for solid-liquid separation of the activated sludge mixture by using the natural head in the room as a driving pressure.

[0005] In the membrane separation device 10, membrane cartridges 12 are arranged in parallel in a box-shaped casing 11 which is open at the top and bottom at appropriate intervals, and a suction tube 13 is connected to the membrane permeation side of each membrane cartridge 12. And suction header tube 14
Are sequentially provided. A filtrate tube 15 is provided with one end communicating with the suction header tube 14, and the other end of the filtrate tube 15 penetrates the partition wall 4 and is guided into the filtrate chamber 5. The other end of the filtrate tube 15 is provided with an electromagnetic valve 16 connected to the control device 9a. An aeration device 17 for supplying aeration air to the water to be treated is provided below the membrane cartridge 12.
Are connected to the blower 18.

In the filtrate chamber 5, a disinfecting section 20 provided with a sterilizer 19 is provided so as to cover the opening of the discharge pipe 6, and a pump 21 for guiding the water to be treated in the chamber 5 to the disinfecting section 20 is provided. Is provided.

[0007] Openings 22 and 23 for maintenance are formed in the top of the apparatus, and lids 22a and 23 are provided respectively.
a is provided.

In the sewage treatment apparatus configured as described above, when water to be treated is introduced from the water supply pipe 2, foreign matter is removed from the water to be treated by the screen 7 while passing through the filtration unit 8. Then, it is mixed with the activated sludge mixture in the aeration chamber 3. The water to be treated is blower 18
Under aerobic conditions in which aerated air is supplied through the aeration device 17, biological treatment is performed by the action of activated sludge while being stirred by the bubble flow of the aerated air, and organic matter and nitrogen contained in the water to be treated are removed. Is removed.

The activated sludge mixture in the aeration chamber 3 is solid-liquid separated by the membrane cartridge 12 using the natural head as a driving pressure. Then, the activated sludge is maintained in the room, and the filtrate that has passed through the filtration membrane is sent from the filtrate tube 15 to the filtrate chamber 5 through the suction tube 13 and the suction header tube 14.

The electromagnetic valve 16 is controlled to open and close by the control device 9a, and the water level in the aeration chamber 3 is set to a low water level L.P. W. L.
And high water level H. W. L. Is maintained between.

The treated water flowing into the filtrate chamber 5 is supplied to the pump 2
The liquid is guided to a disinfecting section 20 by 1 and sterilized by a sterilizer 19 and then discharged from the discharge pipe 6 to the outside of the apparatus.

[0014] In the sewage treatment apparatus shown in FIG.
The foreign matter is removed during the passage through the filtration unit 33 provided with a filter, etc., and the water to be treated is stored in the receiving chamber 34, and an appropriate amount thereof is guided to the aeration chamber 36 by an air lift pump 35 or the like.

Then, the water to be treated is mixed with the activated sludge mixture in the aeration chamber 36, and aerated air is supplied under aerobic conditions through an aeration device 38 through an aeration device 38 such as a blower 37. The organic sludge and the nitrogen content in the water to be treated are removed by the action of the activated sludge while stirring with the use of water. Further, suction negative pressure is supplied by the pump 40 to the filtrate side of the membrane separation device 39 provided by immersion in the activated sludge mixture,
By generating a pressure difference between the front and back of the filtration membrane, solid-liquid separation is performed by the filtration membrane, the activated sludge remains in the room, and the filtrate that has passed through the filtration membrane is taken out.

The filtrate is guided to a disinfecting section 41 and disinfected by a sterilizer 42 so as not to impair sanitation. Thereafter, the filtrate is discharged to the outside of the apparatus as a purified water 44 through a filtrate chamber 43.

Level gauges 45 and 46 are provided above the receiving chamber 34 and above the membrane separator 39, and the water 31 to be treated is determined based on the level measured by the level gauges 45 and 46. And the amount of filtrate drawn out by the pump 40 is adjusted, and the minimum liquid level L of the activated sludge mixed liquid for maintaining the filtration membrane in the immersion state is ensured.

[0016]

In the conventional apparatus described above, when the sludge becomes excessive, the manhole cover is opened, a hose of a vacuum car is inserted into an aeration chamber, and the sludge is pulled out (sucked and discharged). If it is inserted into the bottom of the chambers 3 and 36, all the sludge in the aeration chambers 3 and 36 will be extracted, and the sludge will be extremely short after the restart of operation, and the treated water quality will deteriorate. Further, the membrane separation device is easily clogged. It is not impossible to remove sludge by adjusting the amount of sludge, but it requires time and skill.

Further, in the above-mentioned conventional apparatus, when a large amount of water to be treated suddenly flows in, the water in the aeration chambers 3, 36 overflows into the filtrate chambers 5, 43 and is discharged as it is.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a small-sized combined clarification tank in which excessive extraction of sludge is prevented. Also,
An object of the present invention is to provide a small-sized combined septic tank that can prevent sludge from flowing out when a large amount of water flows in abruptly.

[0019]

According to a first aspect of the present invention, there is provided a small-sized combined clarification tank, wherein an aeration tank for aerating the water to be treated is provided in the tank body, and the aeration-treated water is supplied by a membrane module installed in the aeration tank. A small combined septic tank that discharges after filtering membrane water and sterilizing the filtered water in a disinfection tank, wherein a partition wall is set up from the bottom in the aeration tank and the lower part in the aeration tank is divided into a plurality of chambers. It is.

In such a small-sized combined septic tank, when a sludge is pulled out by inserting a hose from a manhole, the sludge in the lower part (the area below the upper end of the partition wall) in the room provided with the membrane module remains without being drawn out. Become like

According to a second aspect of the present invention, there is provided a small-sized combined clarification tank, wherein an aeration tank for aerating the water to be treated is provided in the tank body, and the aeration-treated water is subjected to membrane filtration by a membrane module installed in the aeration tank. In a small-sized combined septic tank that discharges after sterilizing in a disinfecting tank, a preliminary sedimentation tank that overflows and flows in when the water in the aeration tank reaches or exceeds a predetermined water level is provided.

In such a small-sized combined septic tank, the sludge flowing out of the aeration tank into the preliminary settling tank is subjected to sedimentation / separation treatment in the preliminary settling tank, and is prevented from flowing out of the small combined combined septic tank.

According to a third aspect of the present invention, there is provided the small-sized combined septic tank according to the second aspect, further comprising a preliminary disinfecting tank that overflows and flows in when the water in the preliminary sedimentation tank reaches or exceeds a predetermined water level. It is characterized in that the water in the disinfection tank is allowed to flow out.

In such a small-sized combined septic tank, the effluent from the preliminary sedimentation tank is disinfected in the preliminary disinfection tank and discharged after being sufficiently disinfected.

In a fourth aspect of the present invention, there is provided the small-sized combined clarification tank according to the second or third aspect, further comprising a pump for returning the water in the preliminary settling tank to the aeration tank.

In such a small-sized combined septic tank, the sludge and other solids settled in the preliminary sedimentation tank are returned to the aeration tank, so that the sludge concentration in the aeration tank can be maintained at a high level and the amount of solids flowing out can be significantly reduced. Can be reduced.

According to a fifth aspect of the present invention, there is provided the small-sized combined clarification tank, wherein an aeration tank for aerating the water to be treated is provided in the tank body, and the aeration-treated water is subjected to membrane filtration by a membrane module installed in the aeration tank. In the small-sized combined septic tank that is sterilized and discharged after disinfection, an overflow inlet is provided near the inlet of the tank body when the water level in the aeration tank is equal to or higher than a predetermined water level, and the overflow inlet is provided. A conduit communicating with the disinfection tank is provided.

In such a small-sized combined septic tank, when a large amount of water suddenly flows in, the water is short-circuited to the disinfecting tank, thereby preventing sludge from flowing out of the aeration tank.

This overflow inlet is preferably provided on the downstream side of the screen, as described in claim 6, so that water after a certain amount of residue removal treatment is guided to the disinfection tank.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of a small-sized combined septic tank according to an embodiment. Water to be treated flows into an aeration tank 51 from an inlet 51 'of a tank body 50 and is subjected to aeration treatment. . Inside the aeration tank 51, a short partition wall 52 and a screen 53 are provided.
Thus, a first chamber 51a and a second chamber 51b are defined, and diffuser tubes 54 and 55 are arranged in the respective chambers 51a and 51b, and air is supplied from a blower 56. The air diffuser 54 is arranged along the partition plate 52 so as to raise bubbles along the screen 53. The screen 53 is slightly inclined toward the first chamber 51a.

The air diffuser 55 is disposed below the membrane module 57 so as to raise bubbles along the membrane module 57.

The filtered water of the membrane module 57 is supplied to the pipe 6
After being introduced into the disinfection tank 62 by the pump 61 and contacted with the disinfectant 63 to be sterilized, it is discharged from the discharge port 64. Note that the aeration tank 51 is controlled by a level sensor (not shown).
The water level in the pump is detected, and the pump 6
1 is activated. Thereby, the water level in the aeration tank 51 becomes low water level L. W. L. And high water level H. W. L. Is maintained between.

A large amount of water suddenly flows into the aeration tank 51, and the high water level H.p. W. L. When a rise in the water level exceeding the maximum water level occurs, a preliminary sedimentation tank 66 is provided so as to be separated by the aeration tank 51 and the partition plate 65.
H. W. L. Is discharged to the pre-settling tank 60. In the preliminary sedimentation tank 66, the partition plate 5
An advection wall 67 extends in the vertical direction in parallel with 8, and water overflowing the partition plate 65 is guided to a lower part in the pre-sedimentation tank 66 by the advection wall 67. The bottom surface portion 66a of the pre-sedimentation tank 66 is an inclined surface, and
At the deepest part 66b.

The water level in the pre-settling tank 66 is equal to the upper limit water level H.
H. W. L. Is exceeded, the water in the preliminary sedimentation tank 66 overflows the tank wall 70 and flows into the preliminary disinfection tank 71, where the disinfectant 7
After being sterilized by contact with the tank 2, the water overflows the tank wall 73, flows into the disinfection tank 62, and is discharged.

An air lift pump 68 is provided so as to rise from the vicinity of the deepest portion 66b. The air supplied from the blower 56 is discharged from a nozzle 68a, so that water in the pre-sedimentation tank 66 is passed through a pipe 69. And can be returned to the aeration tank 51. This is aeration tank 5
1 is high water level H. W. L. This is because the water in the preliminary sedimentation tank 66 is returned to the aeration tank 51 for processing when the water level falls below the threshold.

In the small-sized combined clarification tank constructed as described above, to remove sludge, the manhole 75 provided on the upper surface of the tank body 50 above the first chamber 51a of the aeration tank is opened, and the hose of the vacuum car is connected to the first tank 51. The sludge is pulled out by inserting it into the first chamber 51a.

In this small-sized combined septic tank, the partition plate 5
2 separates the inside of the aeration tank 51 into first and second chambers 51a and 51b.
The water level inside does not drop below the upper end of the partition plate 52. That is,
Even when the sludge is extracted, the sludge remains in the portion surrounded by the partition plate 52 in the aeration tank second chamber 51b. Therefore, even when the water treatment is restarted thereafter, the wastewater can be sufficiently purified by aeration.

Further, it is possible to prevent the membrane module from being rapidly clogged due to the sludge remaining in the second chamber 51b. The effect that the tank body 50 is reinforced by the partition plate 52 is also obtained.

In this small-sized combined clarification tank, since the preliminary settling tank 66 is provided, the water overflowing the aeration tank 51 is not immediately discharged. In addition, this preliminary sedimentation tank 6
When the water overflows from 6, the water has been subjected to the sedimentation separation treatment in the pre-sedimentation tank 66, and the outflow of solids is small.
Further, the water from the preliminary sedimentation tank 66 is supplied to the preliminary disinfection tank 71.
And, it is sufficiently disinfected by the disinfection tank 62. In addition, since the water in the pre-sedimentation tank 66 flows out via the pre-sterilization tank 71, the outflow of sludge is also reduced.

FIG. 2 (a) is a sectional view of a small-sized combined septic tank according to another embodiment, in which water to be treated flows into a screen tank 82 from an inlet 81 of a tank 80 and a screen 83.
And flows over the overflow wall 84 into the aeration tank 85. Air is supplied from a blower 83b to an air diffuser 83a provided along the lower part of the screen 83, and bubbles are raised along the screen 83 to prevent the screen 83 from being clogged.

The water that has flowed into the aeration tank 85 is
Is aerated by the air ejected from the air. The aerated water is filtered by a membrane module 87, and the filtered water is filtered by a filtered water pipe 88 and a pump 89 in a disinfection tank 90.
After being brought into contact with the germicide 91 and sterilized, it is discharged from the discharge port 92.

The pump 89 has an aeration tank 85 having a predetermined low water level L.W. W. L. And high water level H. W. L. Is controlled by a control device (not shown).

A diffuser tube 93 is also provided below the membrane module 87, and air is supplied to the diffuser tubes 86 and 93 from a blower 94. A partition plate 96 is raised from the bottom of the tank body 80 near the membrane module 87, and the inside of the aeration tank 85 is partitioned into a first chamber 85a and a second chamber 85b. The membrane module 87 is disposed in the second chamber 85b.

An opening 9 is provided below the screen tank 82.
A residue concentrate storage tank 98 is provided, which communicates with the screen tank 82 via.

As shown in FIG. 2 (b), the screen 83 comprises, for example, a punched metal (fine-grained screen) 83a having a punch hole diameter of 2 mm and a slit plate (fine-grained screen) 83b having a slit width of about 3 to 30 mm. A slit 83 extending in the vertical direction is provided in the slit plate 83b.
c is provided.

When the amount of inflow water is normal, all water passes through the punching metal 83a and overflows the overflow wall 84.
When a large amount of water suddenly flows in, the water levels in the screen tank 82 and the aeration tank 85 become higher than the upper end of the overflow wall 84, and when the water reaches the slit plate 83b, this water passes through the slit 83c.

When a large amount of water flows in abruptly, the water level in the aeration tank 85 becomes higher than the high water level H.
W. L. May be higher. In such a case,
In order to prevent the sludge in the aeration tank 85 from flowing into the disinfection tank 90, an overflow inlet 100 is provided on the side of the screen tank 82 downstream of the screen 83 and immediately adjacent to the screen 83, and overflows on the side of the disinfection tank 90. An outlet 102 is provided and these overflow inlets 10 are provided.
0 and the overflow outlet 102 are communicated by an overflow conduit 101. As a result, the inflowing water is short-circuited to the disinfecting tank 90 through the conduit 101, and the outflow of sludge from the aeration tank 85 is prevented.

Since the overflow inlet 100 is provided on the downstream side of the screen 83, the water flowing into the tank 80 is separated after the coarse solids are separated by the screen 83.
It is led to the disinfection tank 90.

Even in the small-sized combined septic tank constructed as described above, in order to perform the sludge extraction, the first chamber 85a of the aeration tank is required.
The manhole 99 provided on the upper surface of the tank body 80 above is opened, a hose of a vacuum car is inserted into the first chamber 85a, and the sludge is pulled out.
Since the inside of 5 is partitioned into the first and second chambers 85a and 85b, the water level in the second chamber 85b does not drop below the upper end of the partition plate 96 even when the sludge is drawn out. That is, even if the sludge is extracted, the sludge remains in the portion surrounded by the partition plate 96 in the aeration tank second chamber 85b. Therefore, even when the water treatment is restarted thereafter, the wastewater can be sufficiently purified by aeration. Also, it is possible to prevent the membrane module 87 from being rapidly clogged. In addition, the effect that the tank body 80 is reinforced by the partition plate 96 is also exerted. Furthermore, the lower part of the aeration tank first chamber 85a is partially anaerobic by aerating and agitating it in a spot by a diffuser tube 86, so that there is also an effect of removing the chamber.

[0050]

As described above, according to the small-sized combined septic tank of the present invention, excessive extraction of sludge from the tank can be reliably prevented, and the quality of treated water can always be improved.

Further, according to the present invention, the outflow of sludge from the aeration tank can be prevented, and the quality of treated water can always be improved.

In the present invention, even when a large amount of water suddenly flows in, it is possible to sufficiently perform disinfection.

[Brief description of the drawings]

FIG. 1 is a sectional view of a small-sized combined septic tank according to an embodiment.

FIG. 2 is a cross-sectional view of a small-sized combined septic tank according to another embodiment.

FIG. 3 is a sectional view showing a conventional example.

FIG. 4 is a sectional view showing another conventional example.

[Explanation of symbols]

 50,80 Tank body 51,85 Aeration tank 51a, 85a First chamber 51b, 85b Second chamber 52,96 Partition plate 57,87 Membrane module 62,90 Disinfection tank 66 Preliminary sedimentation tank 71 Preliminary disinfection tank 75,99 Manhole 83 Screen 100 overflow inlet 101 overflow conduit 102 overflow outlet

Claims (6)

[Claims] An aeration tank for aerating water to be treated is provided in the tank body, and the aeration-treated water is subjected to membrane filtration by a membrane module installed in the aeration tank, and the filtered water is sterilized in a disinfection tank. A small combined septic tank for discharging a small combined septic tank, wherein a partition wall is raised from a bottom surface in the aeration tank and a lower portion in the aeration tank is divided into a plurality of chambers. 2. An aeration tank for aerating the water to be treated is provided in the tank body, and the aeration-treated water is subjected to membrane filtration by a membrane module installed in the aeration tank, and the filtered water is sterilized in a disinfection tank. A small-sized combined septic tank, which comprises a preliminary settling tank that discharges and discharges when the water in the aeration tank reaches or exceeds a predetermined water level. 3. The pre-disinfection tank according to claim 2, further comprising a pre-disinfection tank that overflows and flows in when the water in the pre-settling tank reaches or exceeds a predetermined water level. A small-sized combined septic tank characterized by the above. 4. The small-sized combined purification tank according to claim 2, further comprising a pump for returning water from the pre-settling tank to the aeration tank. 5. An aeration tank for aerating the water to be treated is provided in the tank body, and the aeration treatment water is subjected to membrane filtration by a membrane module installed in the aeration tank, and the filtered water is sterilized in a disinfection tank. In the small-sized combined septic tank to be discharged, an overflow inlet is provided near the inlet of the tank body when the water level in the aeration tank becomes equal to or higher than a predetermined water level,
A small-sized combined septic tank, wherein a conduit communicating the overflow inlet with the disinfecting tank is provided. 6. The screen according to claim 5, wherein a screen through which inflow water passes is provided near the inflow port in the tank body, and the overflow inflow port is provided downstream of the screen. Small merger septic tank.