JP2001246390A - Two bed juxtaposition type aerobic filter bed tank, septic tank and operation method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a aerobic filter bed tank, a septic tank and an operation method thereof which gives treated water of good quality and contributes energy-saving. SOLUTION: In this aerobic filter bed tank, a biological reaction vessel 13 having a biological reaction bed 5 and a filter vessel 14 having a filter bed 6 are juxtaposed across a partition wall 15 in this order from the upstream side, a diffusing member 9 for reaction is disposed on the lower part or the lower side of the biological reaction bed 5 and a diffusing member 10 for washing is disposed on the lower part or the lower side of the filter bed 6. Therein, further, a space part 7 is disposed on the lower side of the filter bed 6 and a suction port of a transfer pump 11 is disposed on the space part 7 or in the vicinity thereof. The quality of the treated water is made excellent thereby. If only the discharge speed of waste washing water at washing is slightly larger than the natural flow speed, it is satisfactory and, therefore, contributes the energy-sawing. This aerobic filter bed tank can be attached to a conventional single manure disposal purifying tank and allows the manure disposal tank to be transferred to a combined treatment septic tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the treatment of sewage (drainage) into which human waste and gray water are combined, and to the addition of an additional facility to an existing septic tank, which can be converted to a combined septic tank. The present invention relates to a side-by-side aerobic filter bed tank, a sewage purification tank equipped with this two-bed side-to-side aerobic filter bed tank, and a method of operating these.

[0002]

2. Description of the Related Art An aerobic treatment tank in a sewage purification tank is divided into two tanks (or chambers), a biological reaction tank (room having a biological reaction bed) and a filtration tank (room having a filtration bed). At the time of sewage treatment (during biological reaction), the liquid flows through the biological reaction bed in a downward flow, and then flows upward through the filter bed. When the filter bed is washed, the air diffuser for washing is installed below the filter bed. Bubbly with the filter medium, and the buoyant suspension adhered to the filter medium (hereinafter referred to as S
Called S. ) Is released, and at the same time, the treated water in the biological reaction tank is passed through the filter bed in the upward flow as the washing water as in the case of ordinary sewage treatment, and then the air is lifted from the air lift pump suction port installed above the filter bed. A method for draining water is already known (Japanese Patent Laid-Open No. 5-104086).

[0003]

However, in this method, the SS is easily trapped in the lower part of the filter medium due to the characteristics of the upward flow filtration system, and the trapped SS is released even during ordinary sewage treatment, so that the SS is separated. There is a problem that the deposited SS becomes deposited sludge, which is anaerobic and leads to deterioration of treated water. In addition, the flow of the liquid in the filtration tank at the time of washing the filtration bed is an upward flow, and since the washing water needs to carry the liberated SS, the liquid passing speed must be increased to a predetermined value or more (thus, A large amount of air must be sent to the air lift pump), which requires a lot of energy. An object of the present invention is to solve the above-mentioned problems, that is, to provide an aerobic filter bed tank, a sewage purification tank, and a method of operating these, which can obtain treated water having good water quality and contribute to energy saving. .

[0004]

Means for Solving the Problems In order to achieve the above object, the present invention has the following configuration. That is, in the aerobic filter bed tank of the present invention, the biological reaction tank 13 having the biological reaction bed 5 and the filtration tank 14 having the filtration bed 6 are juxtaposed in this order from the upstream side with the partition wall 15 interposed therebetween. An aerobic filter tank in which a reaction air diffuser 9 is installed below or below the bed 5 and a cleaning air diffuser 10 is installed below or below the filter bed 6; The aerobic filter tank 3 is provided with a space 7 below the floor 6, and the suction port of the transfer pump 11 is arranged in or near the space 7.

[0005] In the aerobic filter bed tank 3, during normal processing (during biological reaction), sewage can flow down the biological reaction bed and then flow upward through the filter bed.

[0006] In the aerobic filter bed tank 3, the filler to be filled in the filter bed 6 is preferably a floating filler. When diffused and agitated inside the filter bed 6, the buoyant filler floats first, and the SS released from the filler (filter medium) easily migrates to the space 7 below the filter bed 6 (accordingly,
It is easy to effectively pull out SS from the suction port), filtration bed 6
This is because the transparency of the liquid passing through is high.

Further, in the aerobic filter bed tank 3, the liquid in the lower part of the biological reaction tank 13 is removed during the ordinary sewage treatment.
The structure is such that it flows into the lower part. Therefore, biological reaction tank 1
An advection port 8 may be provided at the lower part of the partition wall 15 between the filter tank 3 and the filtration tank 14 so that the lower part of the biological reaction tank 13 communicates with the lower part of the filtration tank 14. Also, regardless of the advection port 8, the taxiway 2
The liquid in the lower part of the biological reaction tank 13 may be guided to the lower part of the filtration tank 14 by 0a and 20b.

The biological reaction bed 5 is located in one section (room or tank) formed by the outer tank wall and the partition wall 15, and is capable of covering the upper horizontal surface and the lower horizontal surface, respectively. Usually, it is sandwiched between upper and lower sheets) and can be formed by filling a filler as a biological carrier (contact material) therein. Further, the filtration bed 6 is located in one section (room or tank) formed by the outer tank wall and the partition wall 15, and is capable of covering the upper horizontal surface and the lower horizontal surface, respectively. 2 sheets), and a filler such as a filter medium is filled therein.

Further, the transfer pump 11 used in the present invention
Is not particularly limited as long as the liquid can be sent. Preferably, the air lift pump consumes less power.

[0010] The present invention also relates to a sewage purifying tank utilizing the aerobic filter bed tank 3 and incorporating the same. Preferred such sewage purification tanks are, in order from the upstream, an anaerobic treatment tank (1, 2), the aerobic filter bed tank 3, and a disinfection tank 4
It is a sewage septic tank provided with:

The present invention further relates to a method for operating the aerobic filter bed tank. That is, when the aerobic filter bed tank 3 is operated, during normal processing, the biological reaction bed 5 flows downward and the filtration bed 6 flows upward, and the gas diffuses from the reaction diffusion member 9. When the filter bed is washed, the air is not diffused from the cleaning air diffusion member 10 while the air is diffused from the cleaning air diffusion member 10.
Aerobic filter bed tank characterized in that washing water is drawn out from a transfer pump suction port provided in or near the space 7 below the filtration bed 6 (the drawn washing water is separately treated). It is a driving method.

In the above operating method, the air diffuser from the reaction air diffuser 9 during the normal treatment may be continuous air diffusion, but preferably intermittently performing air diffusion and air diffusion stop alternately. It is a diffuse. In addition, it is preferable that the sewage supply to the aerobic filter bed tank is intermittently performed during the normal treatment in synchronization with the intermittent aeration.

[0013] The present invention also relates to a method of operating the sewage treatment tank. When operating the sewage septic tank of the present invention,
During normal treatment, sewage is supplied to the anaerobic treatment tank 1, and in the aerobic filter bed tank 3, the biological reaction bed 5 is caused to flow downward and the filtration bed 6 is caused to flow upward. 9, air is diffused from the cleaning air diffusion member 10, but not from the cleaning air diffusion member 10. At the time of cleaning the filtration bed 6, the air is diffused from the cleaning air diffusion member 10 and the space 7 below the filtration floor 6 or Washing drainage sucked from a transfer pump suction port provided in the vicinity is returned to a tank upstream of the aerobic filter bed tank 3.

In the above-mentioned operating method, during the normal processing, the air diffuser from the reaction air diffuser 9 can be continuous air diffuser. However, it is preferable that the air diffuser and the air diffuser stop are alternately repeated. It is a diffuse. Further, it is preferable that the liquid transfer from the anaerobic treatment tank 2 to the aerobic filter bed tank 3 is intermittently performed during the normal treatment in synchronization with the intermittent aeration.

[0015]

During the normal sewage treatment, the liquid flows upward in the filtration tank 14, so that the SS is trapped at a high concentration in the lower part of the filtration bed 6. The trapped high-concentration SS is released from the filter medium during washing and moves to the space 7 below the filter bed 6, where it is removed.
Is effectively withdrawn from the transfer pump suction port provided in or near the space 7 below the cleaning section together with the washing drainage. At this time, the speed of pulling out the washing wastewater at the time of washing is not particularly limited. In addition, during normal sewage treatment, in the case of intermittent air diffusion where air diffusion into the aerobic filter bed tank 3 alternately alternates between air diffusion and air diffusion stop, the air becomes a semi-anaerobic state (or an anaerobic state). A denitrification reaction also occurs in the aerobic filter bed 3. If the liquid transfer from the anaerobic treatment tank 2 to the aerobic filter bed tank is performed intermittently and periodically during normal processing in synchronization with the intermittent aeration, the denitrification reaction further proceeds.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below more specifically with reference to the drawings. FIG. 1 shows an example of an aerobic filter bed tank 3 according to the present invention. As a filler to be filled in the biological reaction bed 5 and the filtration bed 6, one sponge carrier as a granular carrier is used for both. The biological reaction bed 5 is formed in the biological reaction tank 13, and a reaction air diffuser 9 is provided below the biological reaction bed 5. Further, a filtration bed 6 is formed in the filtration tank 14, and a cleaning air diffuser 10 is provided below the filtration bed 6. A space 7 is provided below the filter bed 6, and an air lift pump (its suction port) 11 for returning washing wastewater to the anaerobic treatment tank 1 when washing the filter bed 6 is provided in the space 7. Is provided.

A water-permeable plate 19 is disposed above the biological reaction bed 5 and holds the filled carrier so as not to flow out. An advection port 8 is provided at the lower part of the biological reaction tank 13, and the sewage treated in the biological reaction tank 13 is transferred to the filtration tank 14 via the advection port 8. Further, the water-permeable plate 1
9 is provided to prevent the carrier from flowing out.

At the time of ordinary sewage treatment (during biological reaction), the biological reaction bed 5 is used to perform aerobic treatment of sewage (drainage).
The air is discharged from the air diffuser 9 provided at the lower part of the pipe. At that time, the carrier in the biological reaction bed 5 flows up and down by the effect of aeration. At the time of washing the filter bed 6, air may be discharged from the air diffuser 9, but is not normally discharged. In the biological reaction bed 5, oxidation and decomposition of organic substances and nitrification of ammonia mainly proceed.

At the time of ordinary sewage treatment, the filter bed 6 flows upward with the liquid transferred from the lower part of the biological reaction bed 5, and the aerobic reaction is continued by the oxygen (dissolved oxygen) carried in the bed. State) to capture (filter) the SS. The filter bed 6 gradually closes. The trapped SS naturally releases from the packing material and falls to the bottom of the space 7 below the filtration bed,
There are also parts that become sedimentary sludge. The filter bed 6 and the space 7 are periodically cleaned in order to block the filter bed 6 and remove the accumulated sludge. At the time of washing, air is discharged from the washing air diffuser 10 provided below the filter bed 6 to stir the space 7 and to flow the filler in the filter bed 6 to release the trapped SS. Let it.

The washing wastewater containing the liberated SS and sediment sludge is pulled out using an air lift pump 11. At this time, it is preferable that the suction port of the air lift pump 11 be installed at the deepest part of the space 7. Further, it is preferable that the air diffuser 10 is also provided at the deepest part of the space 7.

A water-permeable plate 19 is disposed above the filter bed 6 so as to prevent the filler from flowing out. In order to prevent the air from flowing out of the air lift pump 11, a water-permeable plate 19 is usually arranged below the lower part. During normal operation, the liquid flowing through the filter bed 6 is upward, and the filler (particularly, in the case of a floating filler) is pressed upward by the upward flow, so that the trapping (filtration) efficiency is increased.

Washing of the filtration bed 6 and the space 7 is periodically performed by using a timer or the like (usually once a day,
It can be performed automatically for about 30 minutes at night with little inflow of sewage. It is preferable that the time, time, and frequency of cleaning can be set arbitrarily. Further, it is preferable that washing can be performed at any time by manual operation.

The biological reaction bed 5 of the aerobic filter bed tank described above was a fluidized bed during normal operation, but is not limited to a fluidized bed. It may be a fixed bed filled with a filler such as a loofah-like filter medium and a string-like filter medium. Further, the filtration bed 6 may be a fixed bed, but is preferably a fluidized bed, and more preferably a fluidized bed filled with a buoyant filler. Further, no space is formed below the biological reaction bed 5. This is because sludge (SS) generated when the organic matter is oxidized and decomposed accumulates in the space and becomes anaerobic, which adversely affects water quality.

FIG. 2 shows another example of an aerobic filter bed tank 3 according to the present invention.
This is an example in which the space 7 has a hopper shape. When the SS trapped by the filtration bed 6 is released and falls to the bottom of the space 7 below the filtration bed, the space 7 has a hopper shape, so that the accumulated sludge is easily accumulated. Therefore, the accumulated sludge can be efficiently extracted by the air lift pump 11.

FIG. 3 shows another example of an aerobic filter tank according to the present invention. In the aerobic filter tank of FIGS. 1 and 2, the lower part of the biological reaction tank and the lower part of the filter tank communicate with each other through an advection port 8 provided in the lower part of the partition wall 15, but the aerobic filter tank of FIG. 3
As shown in the figure, the liquid in the lower part of the biological reaction tank 13 is guided to the lower part of the filtration tank 14 by the guide paths 20a and 20b.

Next, a sewage purifying tank utilizing the aerobic filter bed tank of the present invention and incorporating the same will be described. FIG. 4 is an example of a sewage purification tank incorporating the aerobic filter bed tank of FIG. This sewage purification tank is provided with an anaerobic filter bed first chamber 1, an anaerobic filter tank second chamber 2, an aerobic filter bed tank 3 (having a biological reaction bed 5 and a filter bed 6), and a disinfection tank 4 from the upstream side. Fractionated in the tank.
The anaerobic filter tank first chamber 1 and the anaerobic filter tank second chamber 2 are filled with a contact material such as a mesh-like cylindrical filter medium, and the biological reaction bed 5 and the filter bed 6 of the aerobic filter tank 3 are filled. A filler (carrier) such as a sponge carrier is filled. The washing drainage of the filtration bed 6 at the time of washing is transferred to the washing drainage transfer pipe 1 by an air lift pump 11.
2 and is returned to the anaerobic treatment tank first chamber 1. The SS released from the filler (carrier) at the time of washing and the accumulated sludge in the space 7 below the filtration bed are returned to the anaerobic treatment tank first chamber 1. Will be returned to

The air diffusion from the reaction air diffusion member 9 during normal processing (during biological reaction) can be continuous air diffusion, but preferably, air diffusion and air diffusion stop are alternately performed periodically. It is intermittent diffusion that is performed repeatedly. The ratio between the air diffusion time and the air diffusion stop time in this intermittent air diffusion is preferably about 2: 1. This is because the nitrification rate is approximately の of the denitrification rate, and when this ratio is set, nitrification and denitrification are performed in a well-balanced manner. During normal processing (during biological reaction), air is not diffused from the cleaning air diffuser 10.

Although not shown, a flow rate adjusting function may be provided on the upstream side of the filtration bed 6 so that the washing wastewater can be temporarily stored. Further, a circulating device for circulating the treated water before flowing into the disinfecting tank 4 to the first anaerobic treatment tank 1 (an air lift pump for circulating water for pumping the treated water and a circulation for transferring the treated water to the first anaerobic treatment tank 1) And a water transfer pipe). In addition, as a tank upstream of the aerobic filter bed tank 3, in addition to the anaerobic filter bed tank (first chamber) 1 and the anaerobic filter bed tank (second chamber) 2, tanks for other purposes (for example, sedimentation separation chamber, (Adjustment tank, pump tank) may be added.

FIG. 5 shows a sewage purification tank incorporating the aerobic filter bed tank of FIG. In this sewage purifying tank, a flow rate adjusting pump 18 is disposed in a transfer pipe 17 from the anaerobic filter tank second chamber 2 to the aerobic filter tank 3, and the flow of liquid through the transfer pipe 17 is intermittently and periodically. I do it. The timing of the advection of the liquid preferably coincides with the timing of the air diffusion from the air diffuser tube 9 to the stop of the air diffusion. This is because, in the biological reaction tank 13, ammonia is converted into nitrate nitrogen by aeration (aerobic state) from the air diffuser 9 (nitrification reaction), and then nitrate nitrogen is converted into nitrogen gas by stopping the aeration (anaerobic state). (Denitrification reaction),
This is because an organic substance (carbon) is required. The time required for advection also varies depending on the amount of inflow into the sewage treatment tank. The other structures of the sewage purification tank (anaerobic filter bed first chamber 1, anaerobic filter tank second chamber 2) are the same as those in FIG.

When the filter bed 6 is washed, a method is employed in which an amount corresponding to the liquid in the filter bed 6 is withdrawn. At the time of washing, air is discharged from the washing diffuser 10 provided below the filtration bed 6, and the washing wastewater at that time is discharged by an air lift pump 11.
Pull out using. The drawing is performed until the water level in the filter bed 6 falls to the water-permeable plate 19 disposed below the filter bed 6.

[0031]

According to the aerobic filter bed tank or the operation method of the present invention, the washing wastewater having a high SS concentration can be drawn out during washing, and the amount of SS remaining in the filtration tank can be reduced. It will be good. Also, the speed of pulling out the washing wastewater at the time of washing may be smaller than in the past, which contributes to energy saving. Moreover, the aerobic filter bed tank of the present invention can be added to an existing (sewer) single treatment septic tank, and can be converted to a combined treatment septic tank.

According to the sewage purification tank or the operation method of the present invention, the washing wastewater having a high SS concentration is returned to the anaerobic treatment tank at the time of washing, so that the amount of SS remaining in the filtration tank can be reduced. Water quality is improved. In addition, the drainage speed of the washing wastewater at the time of washing may be about the level of natural flow due to gravity, and therefore contributes to energy saving. In addition, during normal sewage treatment, if intermittent air diffusion is performed in which air diffusion and air diffusion stop are alternately repeated, a denitrification reaction occurs even in the aerobic filter bed, and nitrogen removal performance is improved.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural view of an example of an aerobic filter bed according to the present invention, as viewed from the side, in which (a) shows a normal operation and (b) shows a washing.

FIGS. 2A and 2B are schematic side views of another example of an aerobic filter bed (having a hopper-shaped space) according to the present invention, in which FIG. 2A shows a normal operation and FIG.

FIG. 3 is a schematic side view of a still another example of an aerobic filter bed according to the present invention.

FIG. 4 is a schematic structural view of an example of a sewage treatment tank according to the present invention as viewed from a side.

FIG. 5 is a schematic structural view of another example of the sewage treatment tank according to the present invention as viewed from the side.

[Explanation of symbols]

1: Anaerobic filter bed first room 2: Anaerobic filter bed second room 3: Aerobic filter bed 4: Disinfection tank 5: Biological reaction bed 6: Filtration bed 7: Space
8: Advection port 9: A diffuser member for reaction (diffusing tube) 10: A diffuser member for cleaning (diffusing tube) 11: Transfer pump (air lift pump) 12: Transfer tube for washing drainage 13: Biological reaction tank 14: Filtration tank 15 : Partition wall 16: Air piping connection port 17: Advection pipe 18: Flow control pump 19: Water-permeable plate material 20 a: Taxiway 20 b: Taxiway

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D003 AA15 BA02 CA02 CA08 DA08 EA15 EA16 EA19 EA28 4D027 AB07 AB14 4D040 BB05 BB07 BB24 BB42 BB54 BB57 BB65 BB66 BB82

Claims (12)

[Claims] 1. A biological reaction tank having a biological reaction bed and a filtration tank having a filtration bed are juxtaposed in this order from an upstream side with a partition wall therebetween, and a diffusion member for reaction is provided below or below the biological reaction bed. Is installed, a lower or lower part of the filter bed is an aerobic filter bed tank in which a diffuser for washing is installed, and a space is provided below the filter bed,
An aerobic filter tank in which the suction port of the transfer pump is arranged in or near the space. 2. The aerobic filter bed tank according to claim 1, wherein during normal treatment, sewage flows downward through the biological reaction bed and upwards through the filter bed. 3. The filler in the filter bed is a buoyant filler.
The aerobic filter bed tank according to claim 1 or 2. 4. The aerobic filter bed tank according to claim 1, wherein the lower part of the biological reaction tank and the lower part of the filtration tank communicate with each other by an advection port provided at a lower part of the partition wall. 5. The aerobic filter bed tank according to claim 1, wherein the liquid in the tank at the lower part of the biological reaction tank is guided to the lower part of the filtration tank by a guide path. 6. An anaerobic treatment tank, in order from the upstream,
A sewage purification tank comprising any of the aerobic filter bed tanks and a disinfecting tank. 7. When operating the aerobic filter bed tank according to any one of claims 1 to 5, during normal treatment, sewage flows through the biological reaction bed in a downward flow and through the filtration bed in an upward flow. The air diffuses from the reaction air diffuser, but does not diffuse from the cleaning air diffuser.When washing the filter bed, while diffusing from the cleaning air diffuser, the space below the filter bed or A method for operating an aerobic filter bed tank in which washing wastewater is drawn out from a transfer pump suction port provided near it. 8. The operating method according to claim 7, wherein during the normal processing, the air diffuser from the reaction air diffuser is intermittent air diffuser in which air diffusion and air diffusion stop are alternately repeated. 9. The operating method according to claim 8, wherein the supply of sewage to the aerobic filter bed tank is performed intermittently in synchronization with intermittent aeration during normal processing. 10. When operating the sewage purification tank of claim 6, during normal processing, sewage is supplied to the anaerobic treatment tank, and
In the aerobic filter bed, the biological reaction bed flows downward and the filter bed flows upward, and diffuses from the diffuser for reaction, but does not diffuse from the diffuser for washing. At the time of washing, the washing drainage sucked from the transfer pump suction port provided in or near the space below the filter bed while diffusing from the washing air diffuser member is a tank upstream of the aerobic filter bed tank. How to operate the sewage septic tank returned to 11. The operating method according to claim 10, wherein during normal processing, the air diffusion from the reaction air diffusion member is intermittent air diffusion in which air diffusion and air diffusion stop are alternately repeated. 12. Synchronizing with intermittent air diffusion during normal processing,
The operation method according to claim 11, wherein the liquid is transferred from the anaerobic treatment tank to the aerobic filter bed tank intermittently.