JP4022815B2 - Solid-liquid separation tank and sewage septic tank having a filter medium layer in the second chamber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solid-liquid separation tank (or a solid-liquid separation and anaerobic treatment tank) and a sewage purification tank incorporating the same as an anaerobic treatment tank. More specifically, a sewage septic tank that physically and biochemically purifies human waste, other domestic wastewater, or a combined sewage (hereinafter also referred to as sewage), and a solid-liquid separation tank suitably incorporated in the sewage septic tank. (Or solid-liquid separation and anaerobic treatment tank).
[0002]
[Prior art]
Various sewage septic tanks used in homes and the like are conventionally known. FIG. 3 is one of sewage purification tanks (conventional example) called an anaerobic filter bed contact aeration system or a precipitation separation contact aeration system. From the upstream side, an anaerobic filter bed tank first chamber (precipitation separation tank first chamber) 51, An anaerobic filter bed tank second chamber (precipitation separation tank second chamber) 52, a contact aeration tank 53, a precipitation tank 54, and a disinfection tank 55 are arranged. The anaerobic filter bed first chamber and the anaerobic filter bed second chamber are provided with a water amount fluctuation absorption part 56 in order to alleviate a large amount of sewage inflow in a short time, and the anaerobic filter bed second chamber 52 is lowered. A flow rate adjusting pump 58 is provided for supplying a constant amount of the advection liquid that has entered the advection pipe 57 after passing through the flow into the subsequent contact aeration tank 53 (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
JP-A-4-367793
[Problems to be solved by the invention]
The present invention has a simpler structure than the first anaerobic filter bed tank and the second anaerobic filter bed tank in such a sewage septic tank, and further has a solid-liquid separation performance (or solid-liquid separation and anaerobic performance). It is an object of the present invention to provide a sewage purification tank capable of purifying sewage more stably than before by providing a treatment tank) and incorporating this solid-liquid separation tank into the sewage purification tank.
[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
A sewage inlet 14 that is above the highest water level (HWL), an advection port 19 that is at the lowest water level (LWL), a precipitation part 20 that has an opening 15 at the bottom, and a lower part of the precipitation part 20. A first solid-liquid separation chamber (first anaerobic treatment chamber; also simply referred to as a first chamber) 11 and a downstream side of the first chamber 11 below the lowest water level. And a second solid-liquid separation chamber (second anaerobic treatment tank; also simply referred to as a second chamber) 12 having a filter medium layer 23 and having a suction port 18 of the transfer pump 13 at the lowest water level. ,
The level of sewage is a solid-liquid separation tank (or solid-liquid separation and anaerobic treatment tank) 10 that can vary between the highest water level (HWL) and the lowest water level (LWL).
[0006]
Here, the opening part 15 provided in the bottom part of the sedimentation part 20 may be provided over the full depth, or may be provided in a part of depth. From the viewpoint of not disturbing the liquid in the sedimentation section 20, it is preferably provided over the entire depth.
[0007]
The present invention is also a sewage purification tank incorporating the solid-liquid separation tank. Typically, it is a sewage purification tank comprising the solid-liquid separation tank (solid-liquid separation and anaerobic treatment tank) and an aerobic treatment tank, a treatment water tank, and a disinfection tank that are sequentially arranged in the downstream. Here, various types of aerobic treatment tanks, treated water tanks and disinfection tanks can be used, and are not particularly limited. In some cases, it is possible to omit the treatment water tank or the disinfection tank.
[0008]
[Action]
In the first chamber 11 of the solid-liquid separation tank (solid-liquid separation and anaerobic treatment tank) 10, in the sedimentation unit 20, the solids that are likely to settle are first precipitated, and the precipitated solids are sludge storage unit. Drop it to 21 and store it there. In the second chamber 12, the solid material is further removed by the filter medium layer 23 formed in the chamber, and the organic substances in the sewage are anaerobically decomposed by the anaerobic microorganisms attached to the filter medium layer 23.
The (outflow) liquid from the solid-liquid separation tank 10 has a structure in which water is pumped from a pump suction port 18 provided at the lowest water level of the second chamber 12. ), The water level in the solid-liquid separation tank 10 rises. However, since the maximum water level (HWL) is set in advance for safety, the inflowing sewage does not overflow beyond the water level (HWL). That is, the water level in the solid-liquid separation tank 10 fluctuates between LWL and HWL.
[0009]
When the sludge storage part 21 and the sedimentation part 20 in the first chamber 11 are partitioned by the inclined partition walls 16 and 17, they are not easily affected by liquid disturbance when the sewage (raw water) flows into the first chamber 11. . Therefore, the solid matter precipitated in the sludge storage unit 21 accumulates at a high concentration, and further, anaerobic decomposition proceeds, scumification is promoted, and scum accumulates (increases) near the water surface. In this case, scum can accumulate at a higher concentration than the precipitated solid.
[0010]
In the solid-liquid separation tank 10 composed of the first chamber 11 and the second chamber 12, the solid matter contained in the sewage can be effectively separated and anaerobic treatment can be performed. Reduce. If this solid-liquid separation tank 10 is incorporated in a sewage septic tank, the processing performance of the sewage septic tank is further improved.
[0011]
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 a solid-liquid separation tank (solid-liquid separation and anaerobic treatment tank) 10 of the present invention. In the first chamber 11, a sewage inlet 14 is provided in the outer wall of the septic tank above the liquid level in the tank, and an advection port 19 for transferring the sewage to the second chamber 12 is provided in the partition wall 25 on the opposite side. Yes. Moreover, the opening part 15 is provided in the lower part of the partition walls 16 and 17 which enclose and oppose the sedimentation part 20 ranging from the wall surface by the side of the sewage inflow port 14 to the full width of the partition wall 25 by the side of the advection opening 19 side.
[0012]
Here, as shown in FIG. 1, the lower end of the partition wall 16 extends longer than the lower end of the partition wall 17 (extends by a distance L in the horizontal direction), and the lower part of the partition walls 16 and 17 is inclined. The angle is preferably 50 to 70 degrees so that the sludge settled in the sedimentation part 20 can easily fall into the sludge storage part 21. Further, the gap (W) of the opening 15 at the bottom of the sedimentation section 20 is used to suppress the speed of the liquid flowing from the sedimentation section 20 into the sludge storage section 21, or the sludge (or solid matter) precipitated in the sedimentation section 20. For reasons such as dropping into the sludge storage section 21, approximately 80 to 150 mm is preferable. The depth (h) from the liquid level to the lower end of the partition wall 16 is about 20 to 80% (more preferably 40 to 60%) of the liquid depth (H).
[0013]
Moreover, it is preferable to stand the water flow suppression plate 24 in the vicinity of the sewage inflow port 14 in the settling portion 20, and the lower part of the water flow suppression plate 24 is further inclined toward the wall on the sewage flow inlet 14 side. preferable.
[0014]
If it does so, the sewage which flowed into the sedimentation part 20 of the 1st chamber 11 from the sewage inflow port 14 will pass through the water flow suppression board 24, and will move to the advection opening 19 by becoming a substantially horizontal flow. During this time, the solid matter having a sedimentation speed faster than the horizontal flow velocity is directed to the opening 15 at the bottom of the sedimentation section 20 and passes there, and then accumulates at the bottom of the sludge storage section 21.
[0015]
Accumulated solid matter is less disturbed by the liquid flow and becomes high in concentration and becomes sludge. The sludge solidified material gradually becomes anaerobic over time, and part of it becomes scum and rises near the liquid surface above the sludge reservoir 21. At this time, the floating scum does not enter the settling portion 20 from the opening 15 because the lower end of the partition wall 16 is longer and lower than the lower end of the partition wall 17 in the horizontal direction as described above. .
[0016]
The suction port 18 of the air lift pump 13 in the second chamber 12 is provided at the LWL position. The water level in the solid-liquid separation tank 10 rises when the amount of inflow of sewage is greater than the amount of liquid fed by the air lift pump 13, falls when it is less, and rises and falls between LWL and HWL. Further, the suction port 18 is provided in the advection pipe 22 in order to prevent inflow of sludge and the like floating on the water surface.
[0017]
The second chamber 12 is provided with a filter bed (filter medium layer) 23 filled with a filter medium. As the filter medium, plate-like members such as loofah-like, corrugated plate-like, porous, etc., honeycomb-like (honeycomb core) members, etc. are preferably used. Skeletal spherical, mesh-like cylindrical members and the like can also be used.
The upper end of the filter bed 23 is preferably below the minimum water level. If the water level is higher than the minimum water level, the upper part of the filter bed 23 becomes repeatedly below the surface of the water or exposed, which adversely affects the stability of the sludge adhesion to the filter medium.
[0018]
In FIG. 1, the transfer pump provided in the second chamber 12 is an air lift pump. However, an intermittent metering pump or an electric pump by pneumatically feeding a sealed container may be used instead of the air lift pump type.
[0019]
Moreover, in FIG. 1, although the whole shape of the solid-liquid separation tank 10 was made into the substantially square shape (box shape) by planar view, it can also be made circular, an ellipse, etc. by planar view depending on the case.
[0020]
FIG. 2 is an example of a sewage purification tank incorporating the solid-liquid separation tank 10. A solid-liquid separation tank 10 composed of a first chamber 11 and a second chamber 12 is provided in the tank, and a (aerobic) biological reaction chamber 31 and a filtration chamber 32 are juxtaposed in the downstream of the solid-liquid separation tank 10. An aerobic treatment tank 30 and a disinfection tank 33 are provided. In addition, since description of the solid-liquid separation tank 10 overlaps with the description in the previous solid-liquid separation tank, it abbreviate | omits.
[0021]
A reaction aeration member (aeration tube) 34 for aeration from the bottom is disposed in the (aerobic) biological reaction chamber 31 constituting the aerobic treatment tank 30, 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. The base material of the microbial carrier includes, for example, synthetic resin processed products such as polyvinyl chloride, polyester, polyvinylidene chloride, polyvinyl formal, polyurethane, melamine resin, inorganic processed products such as ceramics and silica sand, anthracite For example, fossil processed products such as activated carbon, activated carbon and the like having a specific gravity of about 1 or 1 or more, polyolefin resins such as polyethylene and polypropylene, and polystyrene having a specific gravity of about 1 or 1 or less can be used.
[0022]
A transfer pipe 26 is provided between the aerobic treatment tank 30 and the upper part of the sludge storage part 21 of the first chamber 11, and the aerobic treatment tank 30 and the first chamber 11 are utilized to take advantage of the water level difference. The tank liquid in the processing tank 30 is transferred to the sludge storage part 21 in the first chamber 11. Thereby, even when there is no inflow of sewage, the liquid in the tank can be circulated, and the process is stabilized and the SS load is reduced.
[0023]
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 member (air diffuser pipe) 36 for backwashing the filter bed 32a is disposed, and this is connected to a blower 35 for supplying air.
[0024]
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 in the blower 35 is discharged from the cleaning air diffuser 36 to bubbling the filter bed 32a, and a part of the air in the blower 35 is also supplied to the cleaning drainage pump (air lift pump) 37. The peeled SS becomes washing wastewater together with the liquid in the tank, descends the filtration bed 32a, returns to the vicinity of the sewage inlet 14 of the first chamber 11 through the washing drainage discharge pipe 37a by the washing 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 solid-liquid separation tank 10 is LWL (that is, at midnight). This is because in ordinary households, sewage is usually not discharged at midnight, and the solid-liquid separation tank 10 (11 + 12) becomes LWL.
[0025]
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.
[0026]
In FIG. 2, the biological reaction chamber 31 and the filtration chamber 32 are juxtaposed side by side, but this has a two-layered structure, that is, the biological reaction chamber 31 is disposed on the upper side, and the filtration chamber is disposed below the biological reaction chamber 31. 32 can also be arranged. In this case, the flow direction of the advection liquid is usually a downward flow from the biological reaction chamber 31 to the filtration chamber 32.
[0027]
Next, treatment of sewage in the sewage septic tank will be described. The sewage (raw water) enters the settling portion 20 of the first chamber 11 from the sewage inflow port 14, and the solid is settled and separated. The sludge separated in the sedimentation section 20 enters the sludge storage section 21 through the opening 15 at the bottom, is concentrated and stored, and the scum generated by anaerobic storage is stored in the tank top. The advection liquid from the first chamber 11 enters the second chamber 12 through the advection port 19, and further solid separation and anaerobic treatment of the advection liquid are performed by the filter medium formed in the tank. Advection of the advection liquid from the second chamber 12 is performed by the transfer pump 13. At this time, the advection liquid is pumped from the suction port 18 of the LWL, and a predetermined amount (almost constant amount) is transferred from the upper part of the transfer pump 13 to the biological reaction chamber. Advection to 31. At this time, when the amount of raw water flowing in is larger than the transfer amount of the transfer pump 13, the water level of the solid-liquid separation tank 10 rises, but the capacity of the solid-liquid separation tank (flow rate adjusting unit) does not exceed HWL. In general, the water level does not rise above the HWL.
[0028]
In the biological reaction chamber 31, the organic matter in the advection liquid from the solid-liquid separation tank 10 is aerobically biodegraded. 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. The advection liquid that has passed through the filtration chamber 32 enters the sterilization tank 33 and is sterilized, and then discharged from the discharge port 40 as treated water.
[0029]
【The invention's effect】
In the solid-liquid separation tank (solid-liquid separation and anaerobic treatment tank) of the present invention, separation and storage of solid matter contained in the inflowing sewage (raw water) and anaerobic treatment of sewage by both the first chamber and the second chamber. Can be done effectively. In addition, no filter bed is formed in the first chamber, and the structure is simple.
The sewage septic tank of the present invention has a simpler structure than a conventional sewage septic tank of an anaerobic filter bed contact aeration system (or precipitation separation contact aeration system), and can thereby treat sewage stably. In addition, maintenance is easy.
[Brief description of the drawings]
FIG. 1 is an example of a solid-liquid separation 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 an example of a sewage purification tank incorporating the solid-liquid separation tank of 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 schematic longitudinal sectional view of a conventional sewage septic tank.
[Explanation of symbols]
10: Solid-liquid separation tank (solid-liquid separation and anaerobic treatment tank)
11: First solid-liquid separation chamber (first anaerobic treatment chamber; first chamber)
12: Second solid-liquid separation chamber (second anaerobic treatment chamber; second chamber)
13: Transfer pump (air lift pump)
13a: air lift pump pipe 14: sewage inlet 15: opening 16: partition wall (lower slope) 17: partition wall 17a (lower slope) 18: partition wall 18: (pump) suction port 19: transfer port 20: sedimentation Part 21: Sludge storage part 22: Advection pipe 23: Filter medium layer (filter bed) 24: Water flow restraint plate 25: Partition wall 26: Transfer pipe 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 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: Tube 39: Manhole cover 40: Outlet 51: Anaerobic filter bed first chamber (or precipitation separation tank first chamber)
52: Second chamber of anaerobic filter bed (or second chamber of precipitation separation tank)
53: Contact aeration tank 54: Sedimentation tank 55: Disinfection tank 56: Water quantity fluctuation absorption part 57: Advection pipe 58: Flow control pump

Claims (2)

A first solid-liquid consisting of a sewage inlet above the highest water level, an advection port at the lowest water level, a precipitation part having an opening at the bottom, and a sludge storage part provided below the precipitation part. A separation chamber (first chamber), and a second solid liquid downstream of the first chamber, having a filter medium layer below the lowest water level, and provided with a suction port of a transfer pump at the lowest water level Equipped with a separation chamber (second chamber),
Solid-liquid separation tank in which the level of sewage can vary between the highest and lowest levels. A wastewater septic tank comprising the solid-liquid separation tank according to claim 1.

Images