JP4117361B2 - Anaerobic treatment tank equipped with ozone aeration chamber and sewage septic tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anaerobic treatment tank and a sewage septic tank for sewage septic tanks for treating human waste, other domestic wastewater, or combined sewage (hereinafter also referred to as sewage).
[0002]
[Prior art]
Various types of anaerobic treatment tanks for sewage septic tanks have been conventionally known. A typical one includes a precipitation separation tank (solid-liquid separation tank) that separates solids in inflow sewage by gravity precipitation, and a filter bed inhabiting anaerobic microorganisms in the tank. An anaerobic treatment tank for anaerobically biodegrading 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 first chamber 51, an anaerobic filter bed second chamber 52, a biological filtration tank 53, and a treated water tank 54 are shown. And the disinfection tank 55 is arrange | positioned (for example, refer patent document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-96285 [0004]
[Problems to be solved by the invention]
However, in such an anaerobic treatment tank using gravity precipitation or biological treatment, contaminants in the influent sewage can be separated and removed, but organic matter (especially hardly biodegradable organic matter) in the supernatant cannot be effectively degraded. In particular, during the period of time during which the anaerobic microorganisms grow to a certain amount or more in the initial stage of operation or in the low water temperature period when the activity of the microorganisms decreases, the decomposition rate of organic matter slows down. There must be.
The present invention is intended to solve these problems, and is suitable for a sewage septic tank capable of stably decomposing organic matter in the initial stage of operation and winter, and making the capacity of the entire septic tank more compact than before, and this sewage septic tank. It is an object of the present invention to provide an anaerobic treatment tank that is incorporated into the slab.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration .
[0006]
The present invention, in the tank, pumped and ozone aeration chamber 4 having an air diffusion member (diffusion pipes) 15 can be discharged ozone containing air, intracisternal liquid from the liquid level of the minimum water level (L.W.L) Pumping The pump 5 is connected to the pump 5 and is provided with a flow rate adjusting device 6 for transferring a part of the pumped liquid out of the tank and returning the excess liquid to the ozone aeration chamber 4 ( It is also an anaerobic treatment tank (for sewage septic tank).
By providing the pumping pump 5 and the flow rate adjusting device 6, the organic matter can be stably treated without being influenced by the flow rate fluctuation of the inflowing sewage.
[0007]
The present invention is also a sewage septic tank incorporating the anaerobic treatment tank 1. Typically, it is a sewage purification tank comprising the anaerobic treatment tank 1, a second anaerobic treatment tank 25, an aerobic treatment tank 30, a treated water tank 54 (precipitation tank) and a disinfection tank 33 arranged in order in the downstream. Here, various types of second anaerobic treatment tank 25, aerobic treatment tank 30, and treated water tank 54 (sedimentation tank) can be used, and are not particularly limited. Depending on the case, it is possible to omit one or more of the second anaerobic treatment tank 25, the treated water tank 54 (precipitation tank), and the disinfection tank 33.
[0008]
[Action]
It is considered that when air containing ozone is aerated in the liquid, the ozone is decomposed into oxygen (O ₂ ) and oxygen radicals (O) in the liquid, and in some cases, OH radicals and the like are generated. These radicals have a very strong oxidizing action, and in particular, can effectively break the polymer chain and break the unsaturated bond of the hardly biodegradable organic substance.
In the anaerobic treatment tank of the present invention, by aeration of ozone-containing air into the inflow sewage, without being affected by the water temperature and the amount of microorganisms, the organic matter contained in the inflow sewage (particularly difficult biodegradable organic matter) It can be oxidatively decomposed into low molecular weight readily biodegradable organic substances (finally carbon dioxide and water). Furthermore, when this anaerobic treatment tank is incorporated in the sewage septic tank, the organic matter in the inflowing sewage is easily biodegradable, so that the organic matter can be effectively decomposed and removed in the subsequent biological treatment section.
[0009]
DETAILED DESCRIPTION OF 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 septic 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 outlet 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, and a filter bed 20 is provided in the anaerobic filter bed chamber 13 to provide an ozone aeration chamber. 4 is provided with a diffuser member (diffuser 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 can be circular or elliptical 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 plate-like members such as loofah-like, corrugated plate-like, porous, honeycomb-like (honeycomb core) members, etc. Preferably used. Skeletal spherical, mesh-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 the ozone aeration chamber 4 can be provided on the inlet 2 side, the outlet 7 side, and other locations in plan view. Preferably, it is on the outlet 7 side in a plan view as shown in FIG. This is because the liquid after precipitating and removing the impurities in the liquid flowing into the anaerobic filter bed chamber 13 can be aerated with ozone, and the organic substances in the inflowing sewage can be effectively decomposed.
[0013]
Further, a device for adding halide ions, hydrogen peroxide or the like into the ozone aeration chamber 4 may be provided (not shown). This is because these additives react with ozone to generate hypohalous acid, OH radicals, and the like, and further improve the resolution of organic matter.
[0014]
The ozone generator 3 is usually composed of a blower 35 for sending raw material air and an ozone generator 11. In FIG. 1, the blower 35 is provided exclusively for the ozone generator 3, but when there is a blower used in another part, it may be used together.
The ozone concentration supplied from the ozone generator 13 is usually 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 / L. About minutes. Further, the operation of the ozone generator 3 can intermittently perform both ozone generation and air supply, or ozone generation according to the inflow pattern in the inflowing sewage, the organic matter concentration, and the like.
[0015]
The shape of the diffuser member (diffuser tube) 15 can be any shape such as I-shape, H-shape, B-shape, and Japanese-shape in plan view. The shape can be supplied to the entire surface of the air chamber 13, such as an H-shape, a square shape, and a Japanese character shape.
The position of the air diffusion member 15 in the water depth direction is preferably above the lower end of the partition wall 22. When the air diffuser 15 is below the lower end of the partition wall 22, the foreign matter precipitated at the bottom of the anaerobic filter bed chamber 13 is wound up, or the air bubbles generated from the air diffuser 15 pass through the partition wall 22 and anaerobically filter. This is because the solid matter 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 the opening 14 of the partition wall 22 is provided near the liquid surface. In this case, it is preferable to provide an advection portion 16 on 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 influent sewage. The other parts are the same as those in FIG.
[0017]
FIG. 3 shows a pump in the tank of the anaerobic treatment tank of the present invention, a pump 5 for pumping the liquid from the liquid level of the lowest water level (L.W.L), and a flow control 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 provided at the LW L position. Then, the liquid level of the anaerobic treatment tank 1 depends on whether the influent amount of sewage is larger or smaller than the amount of liquid transferred from the flow control device 6 and the maximum water level (HWL). Fluctuate between. However, since H.W.L is set in advance for safety, the inflowing sewage does not overflow beyond the water level (H.W.L).
In FIG. 3, the pump 5 is an air lift pump type, but an intermittent metering pump or an electric pump by pneumatic feeding of a sealed container can be used instead of the air lift pump type.
When the air lift pump type is used for the pump 5, it is preferable to provide the ozone generator 11 between the air lift pump 5 and the blower 35 so that ozone is mixed into the air sent to the air lift pump 5. This is because microorganisms are prevented from adhering to the surface of the air piping in the air lift pump, and the liquid can be stably transferred.
[0019]
Any flow rate adjusting device 6 can be used as long as it can adjust a certain amount of liquid to the outlet 7 and return the excess liquid 8 back into the tank. Preferably, the liquid level in the tank can be adjusted so that the entire amount of sewage pumped up by the pump 5 is transferred into the tank, for example, using a weir. Although the surplus liquid 8 is returned to the ozone aeration chamber 4 in this embodiment, it 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 the circulation ratio) is usually 1 to 10, preferably 3 to 5. When the circulation ratio is smaller than 1, organic substances in the inflowing sewage are not easily removed in the ozone aeration chamber 4 and easily flow from the outlet 7 to the outside of the tank. 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 inflowing sewage from overflowing.
[0021]
FIG. 4 is an example of a sewage purification tank incorporating the anaerobic treatment tank 1 of the present invention.
The sewage purification tank has 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 in the downstream of the anaerobic treatment tank 1. I have.
[0022]
Since the anaerobic treatment tank 1 is as described above, the description thereof is omitted.
The second anaerobic treatment tank 25 is provided with a filter bed 20 below the liquid level. The shape of the filter bed 20 is not particularly limited, and plate-like members such as a loofah-like shape, a corrugated plate shape, and a porous shape, and a honeycomb-like (honeycomb core) member are preferably used. Skeletal spherical, mesh-like cylindrical members and the like can also be used.
[0023]
In the (aerobic) biological reaction chamber 31 constituting the aerobic treatment tank 30, a reaction aeration member (aeration tube) 34 for aeration from the bottom is arranged, and air from the blower 35 is discharged. The biological reaction chamber 31 is formed with a biological reaction bed 31a filled with a carrier (a microbial carrier, a microorganism adhering material, and a contact material), and sewage is aerobically treated in the biological reaction bed 31a. Here, the biological reaction bed 31a may be a fluidized bed or a fixed bed. The shape of the microbial carrier can be various shapes such as plate, net plate, loofah, porous, cylinder, rod, skeleton sphere, string, and granular, irregular lump, cube, and fiber lump. What was processed into can be used. Examples of the base material include synthetic resin processed products such as polyvinyl chloride, polyester, polyvinylidene chloride, polyvinyl formal, polyurethane, and melamine resin, inorganic processed products such as ceramics and silica sand, and fossils such as anthracite. 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 1 or less such as polystyrene can be used.
[0024]
A filtration bed 32a filled with a filter medium is formed in the filtration chamber 32, and the SS in the flowing liquid is captured there. As the filter medium to be filled, one that floats in the liquid can be used, but a sedimentation filter medium is preferable. Examples of sedimentary filter media include synthetic resin processed products such as polyvinyl chloride, polyester, polyvinylidene chloride, polyvinyl formal, polyurethane, and melamine resin, inorganic processed products such as ceramics and quartz sand, and fossil processing such as anthracite. Products, activated carbon, etc., with specific gravity of about 1 or more, or polyolefin resin such as polyethylene, polypropylene, etc., and those with a specific gravity of about 1 or more adjusted by adding fillers to polystyrene. It may be formed and processed into a lump shape, a cylindrical shape, a net shape, a rod shape, a fiber lump shape, or a porous shape.
Further, at the bottom of the filtration chamber 32, a cleaning air diffuser (air diffuser pipe) 36 for backwashing the filter bed 32a is disposed, 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, and therefore the filtration bed 32a is removed periodically or appropriately (reversely). In this cleaning, the air of the blower 35 is discharged from the cleaning air diffuser member 36 to bubble the filter bed 32a, and a part of the air of the blower 35 is also supplied to the cleaning drainage pump (air lift pump) 37. The peeled SS becomes cleaning wastewater together with the liquid in the tank, descends the filtration bed 32a, and returns to the anaerobic treatment tank 1 through the cleaning drainage discharge pipe 37a by the cleaning drainage pump 37. Since all of the liquid in the tank can be drawn out from the bottom of the filtration chamber 32 as washing wastewater, the filtration bed 32a is washed well. Note that an electric pump or the like can be used as the cleaning drainage pump 37. The filtration bed 32a is preferably washed when the water level of the anaerobic treatment tank 1 is LWL (that is, at midnight). This is because, in general households, sewage is rarely discharged at midnight, and the anaerobic treatment tank 1 becomes LW L.
[0026]
A circulation pump 41 that transfers the liquid that has passed through the filtration chamber 32 to the anaerobic treatment tank 1 is provided below the filtration chamber 32 or in the treated water tank 54. This is because when nitrate nitrogen is generated in the aerobic treatment tank 30, when 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 for the circulation pump 41, but an intermittent metering pump or an electric pump by pneumatic feeding of a sealed container may be used instead of the air lift pump type.
[0027]
The disinfection tank 33 is a tank that disinfects or sterilizes the advection liquid from the filtration chamber 32 by contacting the medicine barrel 38. The septic 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 the sewage septic tank will be described. The sewage (raw water) enters the anaerobic filter bed chamber 13 of the anaerobic treatment tank 1 from the sewage inflow port 2, and solids are separated and precipitated. In the anaerobic filter bed chamber 13, concentrated sludge (solid matter) that has settled is stored at the bottom of the tank, and 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 through the transfer portion 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 pumping pump 5. At this time, the advection liquid is pumped from the LW L suction port 10, and a predetermined amount (almost constant amount) is supplied from the flow rate adjusting device 6 connected to the pumping pump 5 to the second anaerobic treatment tank 25. The surplus liquid 8 is transferred to the ozone aeration chamber 4 through the pipe 9. At this time, when the amount of raw water flowing in is larger than the transfer amount of the pump 5, the water level in the anaerobic treatment tank 1 rises from LWL to HWL, but the anaerobic treatment tank 1 Since the capacity of the flow rate adjusting unit 12 is designed not to exceed H.W.L, the water level does not normally rise above H.W.L.
[0029]
The advection liquid from the second anaerobic treatment tank 25 enters the biological reaction chamber 31 and aerobically biodegrades organic matter 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 SS contained in the advection liquid is captured and removed, and in some cases, aerobic organisms are further dissolved by dissolved oxygen brought from the biological reaction chamber 31. Processing is performed. A 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 through the treated water tank 54 and is sterilized, and then discharged from the outlet 40 as treated water.
[0030]
【The invention's effect】
In the anaerobic treatment tank of the present invention, as described above, the organic matter can be stably decomposed even in the initial stage of operation where the microorganisms are not sufficiently grown or in the winter season when the reaction rate of the microorganisms decreases. Furthermore, the amount of stored sludge can be reduced, and the deodorization effect by ozone released into the space in the tank can be obtained.
In the sewage septic tank of the present invention, the organic matter in the inflow sewage is decomposed into readily biodegradable organic matter in the anaerobic treatment tank, so that the organic matter resolution in the biological treatment section at the subsequent stage is improved and the organic matter can be removed more stably. . In addition, the tank capacity can be reduced.
[Brief description of the drawings]
FIG. 1 is a first embodiment of an anaerobic treatment tank (for a sewage septic tank) according to the present invention, in which (a) is a schematic plan view, and (b) is a schematic longitudinal sectional view taken along line AA in (a).
FIG. 2 is a second embodiment of an anaerobic treatment tank (for a sewage septic tank) according to the present invention, in which (a) is a schematic plan view, and (b) is a schematic longitudinal sectional view taken along line AA in (a).
FIG. 3 is a third embodiment of an anaerobic treatment tank (for a sewage septic tank) according to the present invention, in which (a) is a schematic plan view, and (b) is a schematic longitudinal sectional view taken along the line AA in (a).
4 is a schematic longitudinal sectional view of a sewage purification tank incorporating the anaerobic treatment tank of FIG. 3;
FIG. 5 is a schematic longitudinal sectional view of a conventional sewage septic tank.
[Explanation of symbols]
1: Anaerobic treatment tank (for sewage septic tank) 2: Sewage inlet 3: Ozone generator 4: Ozone aeration chamber 5: Pumping pump 6: Flow control device 7: Outlet 8: Surplus liquid 9: Transfer pipe 10: Suction Mouth 11: Ozone generating part 12: Flow rate adjusting part 13: Anaerobic filter bed room 14: Opening part 15: Air diffuser member (air diffuser pipe) 16: Advection part 20: Filter bed 22: Partition plate 24: Tank body 25: Anaerobic treatment Tank 30: Aerobic 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 the reaction (aeration tube)
35: Blower 36: Air diffuser for cleaning (air diffuser)
37: Cleaning drainage pump (air lift pump)
37a: Washing drain discharge pipe 38: Medicine cylinder 39: Manhole cover 40: Outlet 41: Circulation pump 51: Anaerobic filter bed tank first chamber 52: Anaerobic filter bed tank second chamber 53: Biofiltration tank 54: Treated water tank 55 : Disinfection tank

Claims (2)

The tank is provided with an ozone aeration chamber having an air diffuser capable of discharging ozone-containing air, a pump for pumping the liquid in the tank from the liquid level at the lowest water level, and a pump connected to the pump. An anaerobic sewage treatment tank provided with a flow rate adjusting device for transferring a part of the liquid to the outside of the tank and returning the excess liquid to the ozone aeration chamber . A sewage septic tank comprising the sewage anaerobic tank according to claim 1 .

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