JP2004337697A - Anaerobic treatment tank with ozone aeration chamber, and septic tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aerobic treatment tank for a septic tank which can stably decompose organic matter even at the beginning of operation or in winter, and reduce the volume of the whole septic tank in comparison with conventional ones. <P>SOLUTION: The aerobic treatment tank 1 (for the septic tank) is equipped with an ozone aeration chamber 4, which has an air diffusion pipe 15 that can discharge ozone-containing air, in one corner in the tank. In the outer wall part 24, an inflow port 2 for receiving sewage and a discharge port 7, which is an outlet, are generally installed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an anaerobic treatment tank for a sewage purification tank and a sewage purification tank for treating human waste, other domestic wastewater, or a combined wastewater thereof (hereinafter also referred to as sewage).
[0002]
[Prior art]
Various types of anaerobic treatment tanks for sewage purification tanks have been known. A typical one is equipped with a sedimentation separation tank (solid-liquid separation tank) that separates solid matter in the inflowed sewage by gravity sedimentation, and a filter bed in which anaerobic microorganisms live in the tank. An anaerobic treatment tank that anaerobically biodegrades solids.
FIG. 5 shows an example of a sewage purification tank using such an anaerobic treatment tank. From the upstream side, an anaerobic filter bed tank first chamber 51, an anaerobic filter bed tank second chamber 52, a biological filtration tank 53, and a treated water tank 54 are shown. And a disinfection tank 55 (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2001-96285
[Problems to be solved by the invention]
However, in such an anaerobic treatment tank by gravity sedimentation or biological treatment, impurities in the inflowing sewage can be separated and removed, but organic substances (especially hardly biodegradable organic substances) in the supernatant cannot be decomposed effectively. In particular, during the period until the anaerobic microorganisms grow to a certain amount or more in the early stage of operation, or in the low water temperature period when the activity of the microorganisms decreases, the decomposition rate of organic substances becomes slow. There must be.
The present invention is intended to solve these problems, and is capable of stably decomposing organic substances even in the early stage of operation or in winter, and is suitable for a sewage treatment tank and a sewage treatment tank capable of making the whole septic tank more compact than before. An object of the present invention is to provide an anaerobic treatment tank to be incorporated in a refrigeration system.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration.
That is, the present invention is the anaerobic treatment tank 1 (for a sewage purification tank) in which an ozone aeration chamber 4 having an air diffusion member (diffusing tube) 15 capable of discharging ozone-containing air is provided in a part of the tank. .
Here, the tank body (outer wall portion) 24 of the anaerobic treatment tank 1 is usually provided with an inflow port 2 for receiving sewage and a discharge port 7 serving as an outlet.
[0006]
The present invention also provides an ozone aeration chamber 4 having a diffusing member (diffusing tube) 15 capable of discharging ozone-containing air into the tank, and a liquid in the tank based on the liquid level of the lowest water level (LWL). A pump 5 for pumping and a flow control device 6 connected to the pump 5 for transferring part of the pumped liquid to the outside of the tank and returning excess liquid to the ozone aeration chamber 4 are provided. Anaerobic treatment tank (for sewage treatment tank).
The provision of the pump 5 and the flow control device 6 enables the organic matter to be stably processed without being affected by the fluctuation of the flow rate of the inflowing sewage.
[0007]
The present invention is also a sewage purification tank incorporating the anaerobic treatment tank 1 described above. Typically, it is a sewage purification tank provided with the anaerobic treatment tank 1 and a second anaerobic treatment tank 25, an aerobic treatment tank 30, a treated water tank 54 (sedimentation tank), and a disinfection tank 33 which are sequentially arranged in the downstream stream. Here, various types can be used for the second anaerobic treatment tank 25, the aerobic treatment tank 30, and the treatment water tank 54 (settling tank), and there is no particular limitation. In some cases, one or more of the second anaerobic treatment tank 25, the treatment water tank 54 (settling tank) and the disinfection tank 33 can be omitted.
[0008]
[Action]
It is considered that when air containing ozone is aerated in the liquid, the ozone is decomposed in the liquid into oxygen (O ₂ ) and oxygen radicals (O), and in some cases, OH radicals and the like are generated. These radicals have a very strong oxidizing effect, and can particularly effectively break the polymer chain of the hardly biodegradable organic substance and cleave unsaturated bonds.
In the anaerobic treatment tank of the present invention, by aerating the ozone-containing air into the inflowing sewage, the organic matter (especially biodegradable organic matter) contained in the inflowing sewage is not affected by the water temperature or the amount of microorganisms. It can be oxidatively decomposed into lower molecular weight biodegradable organic substances (finally, carbon dioxide and water). Furthermore, when this anaerobic treatment tank is incorporated into a sewage purification tank, organic matter in the inflowing sewage is easily degraded in a biodegradable manner, so that the organic matter can be effectively decomposed and removed in the subsequent biological treatment section.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described more specifically with reference to the drawings.
FIG. 1 is an example of an anaerobic treatment tank (for a sewage treatment tank) of the present invention. The tank body 24 of the anaerobic treatment tank 1 is provided with a sewage inlet 2 and a discharge port 7 at a height above the liquid level in the tank. The inside of the tank is divided into an anaerobic filter bed chamber 13 and an ozone aeration chamber 4 by a partition wall 22 having an opening 14 at the lower end. The anaerobic filter bed chamber 13 is provided with a filter bed 20 and an ozone aeration chamber. 4 is provided with a diffusing member (diffusing tube) 15 connected to the ozone generator 3.
[0010]
The overall shape of the anaerobic treatment tank 1 is a substantially square shape (box shape) in plan view in FIG. This shape may be a circle or an ellipse in plan view, but is preferably a substantially square shape for simplicity.
[0011]
The shape of the filter bed 20 provided in the anaerobic filter bed chamber 13 is not particularly limited, and may be a plate-like member such as a loofah-like, corrugated plate, or porous member, or a honeycomb-like (honeycomb core) member. It is preferably used. Skeletal spheres, net-like cylindrical members, and the like can also be used. The filter bed 20 can be omitted.
[0012]
The installation location of the ozone aeration chamber 4 is not particularly limited, and can be provided at the inlet 2 side, the discharge port 7 side, and other places in plan view. Preferably, it is on the side of the discharge port 7 in plan view as shown in FIG. This is because the liquid after the impurities removed from the liquid flowing into the anaerobic filter bed chamber 13 is settled and removed, and the liquid can be aerated with ozone, and the organic matter in the inflowing sewage can be effectively decomposed.
[0013]
Further, a device for adding halide ions, hydrogen peroxide or the like to the ozone aeration chamber 4 may be additionally provided (not shown). This is because these additives react with ozone to generate hypohalous acid, OH radicals, and the like, and can further enhance the resolution of organic substances.
[0014]
The ozone generator 3 is generally constituted by a blower 35 for sending raw air and the ozone generator 11. In FIG. 1, the blower 35 is provided exclusively for the ozone generator 3. However, if there is a blower used in another part, the blower 35 may be shared.
The concentration of ozone supplied from the ozone generator 13 is generally about 0.01 to 100 mg / L, preferably about 0.1 to 10 mg / L, and the air supply amount is 5 to 100 L / min, preferably 10 to 50 L / min. Minutes. Further, the operation of the ozone generator 3 can perform both ozone generation and air supply, or ozone generation intermittently, according to the inflow pattern in the inflowing sewage, the organic matter concentration, and the like.
[0015]
The shape of the air diffusion member (air diffusion tube) 15 can be any shape such as an I-shape, an H-shape, a square-shape, or a Japanese-shape in a plan view. It has a shape such as an H-shape, a square-shape, or a letter-shape that can be supplied to the entire surface of the air chamber 13.
It is preferable that the position of the air diffusion member 15 in the water depth direction is above the lower end of the partition wall 22. When the diffusing member 15 is located below the lower end of the partition wall 22, impurities deposited on the bottom of the anaerobic filter bed chamber 13 are rolled up, or bubbles generated from the diffusing member 15 pass through the partition wall 22 to be anaerobically filtered. This is because the solid material that enters the floor chamber 13 and is captured by the filter medium 20 is peeled off.
[0016]
FIG. 2 shows another example of the anaerobic treatment tank (for a sewage purification tank) of the present invention, in which an opening 14 of a partition wall 22 is provided near the liquid surface. In this case, it is preferable to provide an advection section 16 at the outlet side of the anaerobic filter bed chamber 13 and the ozone aeration chamber 4 in order to prevent a short circuit of the inflow sewage. The other parts are the same as those in FIG.
[0017]
FIG. 3 shows a pump inside the tank of the anaerobic treatment tank of the present invention, a pump 5 for pumping the liquid in the tank from the liquid level of the lowest water level (LWL), and a flow rate adjustment connected to the pump 5. This is an example in which a device 6 is provided.
[0018]
The suction port 10 of the pump 5 is L.P. W. It is provided at the position of L. Then, the liquid level of the anaerobic treatment tank 1 depends on whether the inflow liquid amount of the sewage is larger or smaller than the liquid amount transferred from the flow control device 6. W. L and the maximum water level (HWL). However, H. W. Since L is set in advance in consideration of safety, the inflow sewage does not overflow the tank beyond its water level (HWL).
Although the pump 5 is shown as an air lift pump in FIG. 3, an intermittent fixed amount pump or an electric pump or the like by air feeding of a closed container can be used instead of the air lift pump.
When an air lift pump type is used for the water pump 5, it is preferable to provide the ozone generator 11 between the air lift pump 5 and the blower 35 to mix ozone into the air sent to the air lift pump 5. This is because microorganisms can be prevented from adhering to the surface of the air pipe in the air lift pump, and the liquid can be stably transferred.
[0019]
Any device can be used as the flow control device 6 as long as it can transfer a fixed amount of liquid to the discharge port 7 and return the surplus liquid 8 to the inside of the tank. Preferably, the liquid level in the tank is L.P. W. In the case of L, it can be adjusted so that the whole amount of sewage pumped by the water pump 5 is transferred into the tank, for example, a dam using a weir. In this embodiment, the surplus liquid 8 is returned to the ozone aeration chamber 4, but may be returned to the anaerobic filter bed chamber 13.
[0020]
The flow rate ratio of the surplus liquid 8 to the liquid to be transferred to the discharge port 7 (hereinafter referred to as a circulation ratio) is usually 1 to 10, preferably 3 to 5. When the circulation ratio is smaller than 1, the organic matter in the inflowing sewage is not removed very much in the ozone aeration chamber 4 and easily flows out of the tank from the discharge port 7. Further, when the circulation ratio is larger than 10, it is necessary to increase the capacity of the flow rate adjusting unit 12 in order to prevent the inflow sewage from overflowing.
[0021]
FIG. 4 is an example of a sewage purification tank incorporating the anaerobic treatment tank 1 of the present invention.
In the sewage purification tank, a second anaerobic treatment tank 25, an aerobic treatment tank 30 in which a (aerobic) biological reaction chamber 31 and a filtration chamber 32 are juxtaposed, and a disinfection tank 33 are provided downstream of the anaerobic treatment tank 1. Have.
[0022]
The anaerobic treatment tank 1 is as described above, and the description is omitted.
In the second anaerobic treatment tank 25, a filter bed 20 is provided below the liquid level. The shape of the filter bed 20 is not particularly limited, and a luffa-like, corrugated, porous or other plate-like member, a honeycomb-like (honeycomb core) member, or the like is preferably used. Skeletal spheres, net-like cylindrical members, and the like can also be used.
[0023]
In the (aerobic) biological reaction chamber 31 that constitutes the aerobic treatment tank 30, a reaction air diffusion member (air diffusion pipe) 34 for aerating from the bottom is disposed, and the air from the blower 35 is discharged. The biological reaction chamber 31 is formed with a biological reaction bed 31a filled with a carrier (microorganism carrier, microorganism adhering material, contact material), and the biological reaction bed 31a aerobically treats wastewater. Here, the biological reaction bed 31a may be a fluidized bed or a fixed bed. Microbial carriers can be in various shapes such as plate, mesh plate, loofah, porous, cylindrical, rod, skeleton spherical, string, and even granular, irregular mass, cube, fiber mass, etc. Can be used. Examples of the base material include synthetic resin products such as polyvinyl chloride, polyester, polyvinylidene chloride, polyvinyl formal, polyurethane, and melamine resin; inorganic materials such as ceramics and silica sand; and fossils such as anthracite. Any of a processed product, activated carbon, or the like having a specific gravity of about 1 or 1 or more, a polyolefin resin such as polyethylene or polypropylene, or a specific gravity of about 1 or less such as polystyrene can be used.
[0024]
In the filtration chamber 32, a filtration bed 32a filled with a filter medium is formed, and captures SS in the flowing liquid. As the filter medium to be filled, a filter medium floating in the liquid can be used, but a sedimentable filter medium is preferable. Examples of the sedimentable filter medium include synthetic resin products such as polyvinyl chloride, polyester, polyvinylidene chloride, polyvinyl formal, polyurethane, and melamine resin, inorganic products such as ceramics and silica sand, and fossil processes such as anthracite. , Activated carbon, etc., specific gravity of about 1 or more, or polyolefin resin such as polyethylene, polypropylene, polystyrene, etc., and filler added to adjust the specific gravity to about 1 or 1 or more. It may be formed and processed into a lump, a cylinder, a net, a rod, a fiber lump, or the like, or a porous or the like.
Further, at the bottom of the filtration chamber 32, a cleaning air diffusion member (air diffusion pipe) 36 for back washing the filtration bed 32a is arranged, and this is connected to a blower 35 for supplying air.
[0025]
If the operation is continued, the filtration bed 32a is clogged with the accumulated SS. Therefore, the filtration bed 32a is periodically or appropriately (reversely) washed and removed. In this cleaning, the air of the blower 35 is discharged from the cleaning air diffusion member 36 to bubble the filtration bed 32a, and a part of the air of the blower 35 is also supplied to a cleaning drainage pump (air lift pump) 37. The stripped SS becomes washing drainage together with the liquid in the tank, descends on the filter bed 32a, and returns to the anaerobic treatment tank 1 through the washing drainage pipe 37a by the washing drainage pump 37. Since all of the liquid in the tank can be withdrawn from the bottom of the filtration chamber 32 as washing wastewater, the filtration bed 32a is favorably washed. It should be noted that an electric pump or the like can be used as the washing drainage pump 37. The washing of the filtration bed 32a is performed when the water level of the anaerobic treatment tank 1 is L.P. W. It is preferably performed at L (that is, at midnight). In general households, sewage is generally rarely discharged in the middle of the night, W. This is because it becomes L.
[0026]
A circulating pump 41 for transferring the liquid having passed through the filtration chamber 32 to the anaerobic treatment tank 1 is provided below the filtration chamber 32 or below the treatment water tank 54. This is because, when nitrate nitrogen is generated in the aerobic treatment tank 30, if this liquid is transferred to the anaerobic treatment tank 1, it can be removed as nitrogen gas in the anaerobic treatment tank 1.
In FIG. 4, an air lift pump type is shown as the circulation pump 41. However, an intermittent fixed amount pump or an electric pump or the like by air feeding of a closed container can be used instead of the air lift pump type.
[0027]
The disinfecting tank 33 is a tank for disinfecting or disinfecting the advancing liquid from the filtration chamber 32 by contact with the medicine cartridge 38. The sewage purification tank is provided with a manhole so that maintenance and management such as inspection and cleaning of each tank can be performed, and a manhole cover 39 is usually attached.
[0028]
Next, treatment of sewage in a sewage treatment tank will be described. The sewage (raw water) enters the anaerobic filter bed room 13 of the anaerobic treatment tank 1 from the sewage inflow port 2, and the solids are separated and separated. In the anaerobic filter bed room 13, the concentrated sludge (solid matter) is stored at the bottom of the tank, and the scum generated by anaerobic storage is stored at the top of the tank. The advection liquid from the anaerobic filter bed chamber 13 is transferred to the ozone aeration chamber 4 via the advection section 16, and the organic matter in the inflowing sewage is oxidatively decomposed by ozone. Advection from the ozone aeration chamber 4 is performed by a water pump 5. At this time, the advection liquid was L. W. L from the suction port 10, and a predetermined amount (almost constant amount) is transferred from the flow control device 6 connected to the pump 5 to the second anaerobic treatment tank 25 from the discharge port 7, and the excess liquid 8 is transferred to the pipe 9. And then transferred to the ozone aeration chamber 4.
At this time, when the amount of raw water flowing in is larger than the transfer amount of the pump 5, the water level of the anaerobic treatment tank 1 becomes L.P. W. L to H. W. L, but the capacity of the flow rate adjusting section 12 of the anaerobic treatment tank 1 is H.L. W. L is usually designed so as not to exceed L. W. Does not rise above L.
[0029]
The advection liquid from the second anaerobic treatment tank 25 enters the biological reaction chamber 31, and aerobically biodegrades organic substances in the advection liquid. At this time, since a substantially constant amount of advection liquid is loaded, stable processing is performed. The advection liquid from the biological reaction chamber 31 then enters the filtration chamber 32, where the SS contained in the advection liquid is captured and removed, and in some cases, the dissolved oxygen introduced from the biological reaction chamber 31 further aerobic organisms. Processing is performed. Part of the liquid that has passed through the filtration chamber 32 is transferred to the anaerobic treatment tank 1 by the circulation pump 41 to denitrify nitrate nitrogen contained in the liquid. The advection liquid that has passed through the filtration chamber 32 enters the disinfection tank 33 via the treatment water tank 54 and is disinfected, and then is discharged from the discharge port 40 as treatment water.
[0030]
【The invention's effect】
As described above, the anaerobic treatment tank of the present invention can stably decompose organic matter even in the early stage of operation when microorganisms are not sufficiently grown or in winter when the reaction rate of microorganisms decreases. Furthermore, the effect of reducing the amount of stored sludge and the effect of deodorizing ozone discharged into the space in the tank can be obtained.
In the sewage treatment tank of the present invention, since the organic matter in the inflowing sewage is decomposed into easily biodegradable organic matter in the anaerobic treatment tank, the organic matter resolution in the subsequent biological treatment section is improved, and the organic matter can be more stably removed. . In addition, the capacity of the tank can be reduced.
[Brief description of the drawings]
FIG. 1 is a first embodiment of an anaerobic treatment tank (for a sewage purification tank) according to the present invention, wherein (a) is a schematic plan view and (b) is a schematic longitudinal sectional view taken along the line AA of (a).
FIG. 2 is a schematic plan view of a second embodiment of the anaerobic treatment tank (for a sewage purification tank) of the present invention, and FIG. 2 (b) is a schematic longitudinal sectional view taken along the line AA of FIG.
3A is a schematic plan view of a third embodiment of an anaerobic treatment tank (for a sewage purification tank) of the present invention, and FIG. 3B is a schematic longitudinal sectional view taken along line AA of FIG.
FIG. 4 is a schematic vertical sectional view of a sewage purification tank incorporating the anaerobic treatment tank of FIG.
FIG. 5 is a schematic longitudinal sectional view of a conventional sewage purification tank.
[Explanation of symbols]
1: Anaerobic treatment tank (for sewage purification tank) 2: Sewage inlet 3: Ozone generator 4: Ozone aeration chamber 5: Pump pump 6: Flow control device 7: Discharge port 8: Excess liquid 9: Transfer pipe 10: Suction Mouth 11: Ozone generation part 12: Flow control part 13: Anaerobic filter bed room 14: Opening part 15: Aeration member (aeration tube) 16: Advection part 20: Filter bed 22: Partition plate 24: Tank body 25: Anaerobic treatment Tank 30: Aerobic treatment tank (31 + 32)
31: (Aerobic) biological reaction chamber 31a: Biological reaction bed 32: Filtration chamber 32a: Filtration bed 33: Disinfection tank 34: Aeration member for reaction (aeration tube)
35: Blower 36: Air diffuser for cleaning (air diffuser)
37: Cleaning drainage pump (air lift pump)
37a: Cleaning drainage pipe 38: Medicine tube 39: Manhole cover 40: Discharge port 41: Circulation pump 51: Anaerobic filter bed tank first chamber 52: Anaerobic filter bed tank second chamber 53: Biological filtration tank 54: Treatment water tank 55 ： Disinfection tank

Claims (3)

An anaerobic treatment tank provided with an ozone aeration chamber having a diffuser capable of discharging ozone-containing air in a part of the tank. In the tank, an ozone aeration chamber having a diffusing member capable of discharging ozone-containing air,
A pump for pumping liquid in the tank from the liquid level of the lowest water level,
An anaerobic treatment tank which is connected to the water pump and is provided with a flow control device for transferring a part of the pumped liquid to the outside of the tank and returning the surplus liquid to the ozone aeration chamber. A sewage purification tank provided with the anaerobic treatment tank according to claim 1.

Images