JP2007038096A - Removed sludge separator and septic tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable shortening of the length of a sludge pumping pipe by realizing the back washing of a filter layer, and the air lifting of removed sludge by one series of pipe and one blower motor. <P>SOLUTION: A removed sludge separator comprises a chamber 3 having an advection port 2 enabling the inflow of water to be treated mixed with the removed sludge, the filter layer 4 provided more downward than the advection port 2 in this chamber 3, a discharge port 5 formed below the filter layer 4 of the chamber 3, a diffusion part 6 provided more downward than the filter layer 4 and the sludge pumping pipe 7 communicating into the chamber 3 above the filter layer 4, wherein the diffusion part 6 is provided so as to regularly carry out diffusion which cleans the filter layer 4 and the removed sludge on the filter layer 4 is configured to be air-lifted in the sludge pumping pipe 7 by this diffusion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for separating exfoliated sludge from water to be treated in a sewage septic tank for treating combined sewage by a contact aeration method, and particularly to a technique suitable for a biological filtration method.

  The sewage purification tank as described above has a structure in which a plurality of treatment tanks are formed by partitioning a tank body generally formed of a synthetic resin or the like. As said processing tank, a separation filter bed tank, an anaerobic processing tank, an aerobic processing tank, etc. are provided. The water to be treated in the tank is transferred from the upstream treatment tank to the downstream treatment tank so as to maintain a constant water level between the treatment tanks.

  In the aerobic treatment tank, organic sludge in the water to be treated is decomposed by appropriate microorganisms that land on the contact material. Therefore, biological sludge converted from organic waste or biofilm sludge separated from the contact material (hereinafter referred to as these) Collectively known as exfoliated sludge).

  The exfoliated sludge in the water to be treated is filtered in a filtration chamber communicating with the aerobic treatment tank, and / or separated by specific gravity in a treatment tank provided on the downstream side of the aerobic treatment tank. The treated water from which the peeled sludge has been separated is transferred to the disinfection tank, and finally discharged as treated water from the outlet of the tank body.

  As a sewage septic tank provided with the above filtration chambers, there is a biological filtration type. The filtration layer in the biological filtration system generally has a structure filled with a filter medium such as a granular ceramic of about several mm. This is because the filtration layer is provided with a biological decomposition function and a physical filtration function. As a result, the filtration layer has a structure that is easily clogged due to accumulation of trapped exfoliated sludge and biofilm attached to the filter medium. It becomes.

  When the filtration layer is clogged by the exfoliated sludge adhering to the filtration layer, the filtration resistance increases and a predetermined amount of filtered water cannot be obtained. For this reason, in the sewage septic tank provided with the filtration chamber, the filtration layer is regularly backwashed.

  Specifically, a backwashing air diffuser that blows air to the filter layer is provided below the filtration chamber, and the air diffuser blows air at a preset time such as at night. It has become.

  The filtration layer is layered in a non-backwash state, and filters the water to be treated that has flowed from the aerobic treatment tank side, and is agitated entirely by air blow from a backwashing air diffuser. It has a structure.

  The separated sludge trapped in the filtration layer and the biofilm attached to the filter medium are washed by the flowing water accompanying the stirring and air blowing of the filtration layer. During this time, peeled sludge and the like are returned to the anaerobic treatment tank, separation filter bed and the like together with the water to be treated by the air lift pump, and the peeled sludge and the biofilm are also returned along with this ( For example, see Patent Document 1).

Japanese Patent Laid-Open No. 9-248484 (FIG. 1, paragraphs 0013 to 0018)

  However, in order to sufficiently stir and wash the entire filtration layer, it is necessary to supply air to the air diffuser for backwashing at a pressure higher than that for airlift. For this reason, in the sewage septic tank as disclosed in Patent Document 1, it is necessary to configure the backwash air supply and the air lift air supply with two lines of piping, or to provide a backwash and air lift blower motor. was there.

  Therefore, an object of the present invention is to realize backwashing of a filtration layer and air lift of exfoliated sludge with one series of piping and one blower motor.

  As means for solving the above problems, the present invention includes a chamber having an advection port into which treated water mixed with exfoliated sludge can flow, and a filtration layer provided below the advection port in the chamber, A drain outlet formed below the filtration layer of the chamber, an air diffuser provided below the filtration layer, and a pumping pipe communicated in the chamber above the filtration layer. And the diffuser is provided so as to continuously perform aeration for cleaning the filtration layer, and the separation sludge on the filtration layer is air-lifted into the lifting mud pipe by this aeration. The gist.

  According to the said structure, when the to-be-processed water mixed with peeling sludge is advected in a chamber from a migratory port, it will flow out from a drainage port, after passing a filtration layer from the top to the bottom. In this series of flows, the exfoliated sludge is trapped in the filtration layer.

  Here, by adopting a configuration in which the air diffuser is provided so as to continuously perform air diffuser for cleaning the filtration layer, the exfoliated sludge in the water to be treated does not easily reach the lower part of the filter layer. Further, since the filtration layer is normally washed by this aeration, the biofilm grown on the filter medium is not accumulated in the filtration layer. Therefore, it is not necessary to stir the entire filtration layer to prevent clogging of the filtration layer, and it is sufficient to raise the separation sludge on the filtration layer so that the upper surface of the filtration layer is not clogged with the separation sludge.

  That is, it is possible to perform the backwashing air supply and the airlift air supply in the same manner. Therefore, the peeled sludge on the filtration layer is diffused by the air diffuser in the pumping pipe. By adopting the configuration in which the air is lifted, the backwashing of the filtration layer and the air lift of the peeled sludge can be realized by one line of piping and one blower motor.

  In the above configuration, “continuously aeration” is not limited to continuous aeration, but it is discontinuous as long as backwashing air supply and air lift air supply can be shared. It is a concept that includes aeration.

  As described above, according to the present invention, the backwashing of the filtration layer and the air lift of the exfoliated sludge can be realized by one line of piping and one blower motor.

  Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings. As shown in FIGS. 1 to 3, the sewage purification tank 10 has a structure in which a plurality of treatment tanks are formed by partitioning the inside of the tank body 11. As the treatment tank, a separation filter bed tank 12, an anaerobic tank, and the like. A contact aeration method is provided in which a treatment tank 13, an aerobic treatment tank 14, and a disinfection tank 15 are provided.

  Specifically, the first partition wall 16 between the separation filter bed tank 12 and the anaerobic treatment tank 13 is provided with a first anaerobic treatment layer 17 on the separation filter bed tank 12 side, and the anaerobic treatment tank. A first transfer channel 18 is provided on the 13th side. Further, the upper part of the first anaerobic treatment layer 17 and the first transfer channel 18 are communicated with each other by a transfer port 19 provided in the first partition wall 16. The reference water level WL in the tank body 11 is set by the advection port 19.

  Of the water to be treated in the separation filter bed tank 12, the amount of water that has passed through the first anaerobic treatment layer 17 from the bottom to the top is that combined sewage flows into the separation filter bed tank 12 from the inlet 20 of the tank body 11. (Indicated by arrow A1 in FIG. 1A), pushed out from the advection port 19 so as to maintain the reference water level WL (indicated by arrow A2 in FIG. 1A), flows down the first transfer path 18 Then, it is agitated near the bottom of the anaerobic treatment tank 13 (indicated by an arrow A3 in FIG. 1A).

  The anaerobic treatment tank 13 is provided with a second anaerobic treatment layer 21 so as to be located between the lower end of the first transfer flow path 18 and the reference water level WL. The partition wall 22 between the anaerobic treatment tank 13 and the aerobic treatment tank 14 has a concave portion 23 that enters the anaerobic treatment tank 13 when viewed from above, as shown in FIG. A second advection port 24 is provided on both sides of the recessed portion 23 of the partition wall 22 so as to be positioned on the reference water level WL.

  Of the water to be treated in the anaerobic treatment tank 13, the amount of water that has passed through the second anaerobic treatment layer 21 from below is transferred from the first transfer channel 18 into the anaerobic treatment tank 13. It is pushed out from the second advection port 24 so as to maintain the reference water level WL, and is agitated into the aerobic treatment tank 14 configured as a carrier flow tank (FIG. 1 (b), indicated by an arrow A4 in FIG. 2). .

  The concave portion 23 of the partition wall 22 is partitioned by a standing plate 25 with respect to the aerobic treatment tank 14. In the space surrounded by the concave portion 23 and the standing plate 25, the separation sludge separation device 1 according to the first embodiment is arranged.

  The exfoliated sludge separation device 1 includes a chamber 3 in which an effluent 2 of treated water mixed with exfoliated sludge is formed, a filtration layer 4 provided below the convection 2 in the chamber 3, A drain port 5 formed below the filtration layer 4, an air diffuser 6 provided below the filtration layer 4, and an uplift pipe 7 communicated in the chamber 3 above the filtration layer 4. Prepare.

  The chamber 3 has a cylindrical shape with an open upper end wall 3a and is integrally formed with the standing plate 25. The side peripheral part 3b of the chamber 3 is formed by using a part of the standing plate 25, and the advection port 2 is formed in this part in a slit shape communicating with the aerobic treatment tank. Thereby, the to-be-processed water with which exfoliation sludge was mixed from the aerobic processing tank 14 flows in the chamber 3 through the transfer port 2, and flows down toward the filtration layer 4 (FIG. 1 (a). ) As indicated by arrow A5). For this reason, it is not necessary to connect the pipe for advection pipes to the drain port 5. The advection port 2 can be provided with a check valve.

  The filtration layer 4 has a structure provided transversely in the chamber 3. The lower surface 4 a of the filtration layer 4 is formed of a perforated plate provided transversely in the chamber 3. The filter medium is laminated on the perforated plate. A large number of holes sufficiently smaller than the filter medium are formed in the perforated plate so as not to prevent the water to be treated from passing through the filter layer (not shown). In addition, the lower surface 4a of the filtration layer 4 can be formed with a net instead of the porous plate.

  The filtration layer 4 is maintained in a layered state without being totally stirred by the air diffused by the air diffuser 6. Thereby, the filtration layer 4 exhibits the filtration function of peeling sludge, being wash | cleaned normally. As described above, in the present invention, the tank body can be made compact as much as it is not necessary to provide a space for the installation space in consideration of stirring of the filtration layer.

  In addition, it is desired that the filter medium has a high physicochemical stability and a large amount of microorganisms retained in terms of enhancing biological treatment efficiency. For this reason, as the filter medium, those having pores and voids are suitable, for example, pearlite, shirasu balloon, foamed concrete, activated carbon, porous ceramic, porous glass, polyethylene, polypropylene, polyvinyl chloride, polyurethane and the like. A foamed molded product, a fiber lump in which fibers are entangled irregularly, a nonwoven fabric, a fiber lump in which fibers are bound, and the like can be used.

  In the conventional case, the filter medium has a specific gravity of about 0.9 to 1.1 so that the filtration layer can be easily stirred and washed, and it is difficult to employ an inorganic filter medium having a large specific gravity. However, in this invention, since it is not necessary to stir the filtration layer, it is possible to use a filter medium having a specific gravity larger than the above numerical range.

  When using a filter medium having a low specific gravity as in the conventional filter layer 4, the upper surface of the filter layer 4 is similar to the porous plate or the like in order to prevent the layer shape from being collapsed by the air diffused by the air diffuser 6. A presser plate or net may be installed.

  In the first embodiment, the filter medium of the filter layer 4 is provided so as to keep the settling state against the air diffused by the air diffuser 6. Thereby, it becomes possible to abbreviate | omit the said press plate and a net | network, and can make the capacity | capacitance of the chamber 3 smaller.

  Specifically, granular barley stone is used as the filter medium of the filtration layer 4. Here, the barleystone was used because its specific gravity exceeds 2.0, so that even if the grain size is reduced, it is provided to settle against the aeration of the diffuser 6, the grain size Even if it is made small, it is porous and suitable for holding aerobic bacteria, and the mineral content of barleystone is suitable for activation of aerobic bacteria.

  In the above configuration, when the treated water mixed with the exfoliated sludge is transferred from the transfer port 2 into the chamber 3, it passes through the filtration layer 4 from the bottom to the drain port 5.

  The drain port 5 is formed as a gap opened to the bottom surface of the tank body 11 except for the portion of the standing plate 25 in the side peripheral portion 3 b of the chamber 3. The outside of the drainage port 5 communicates to above the reference water level WL, and the treated water that has passed through the filtration layer 4 flows out of the drainage port 5 (indicated by an arrow A6 in FIG. 1A). ) And advancing into the sterilization tank 15 through a medicine tube 26 provided above the chamber 3 (indicated by an arrow A7 in FIG. 1A). Thus, by adopting a configuration in which the concave portion 23 is partitioned so as to form a transfer channel between the drain port 5 and the downstream processing tank, an advection pipe during this period can be eliminated.

  The air diffuser 6 is composed of an air diffuser disposed below the filtration layer 4. The air diffuser 6 communicates with an air supply pipe 6 a connected to a blower motor outside the tank body 11, and is provided so as to continuously perform air diffuser for cleaning the filtration layer 4.

  Specifically, the air diffuser 6 blows out the air supplied from the air supply pipe 6a as bubbles to the lower surface 4a of the filtration layer 4 over the entire surface. The air diffused in the air diffuser 6 is steadily performed so that the bubbles uniformly pass from the bottom to the top in the entire filtration layer 4 and the exfoliation sludge on the filtration layer 4 rises (FIG. 1A). In FIG. 3, this is indicated by a one-dot chain line B1). The air diffuser 6 is not limited to the air diffuser.

  More specifically, the blower motor is controlled only by ON / OFF. As a result, air is constantly supplied from the air supply pipe 6 a to the air diffuser 6, and bubbles are constantly blown out from the air diffuser 6. In this way, when the air diffused in the air diffuser 6 is steadily performed, the blower motor output control device, timer control and output control become unnecessary, so that the cost of the sewage septic tank can be reduced. The filtration resistance of the filtration layer 4 and the filtration flow rate can be stabilized.

  The exfoliated sludge raised from above the filtration layer 4 due to the air diffused by the air diffuser 6 is air lifted into the mud pipe 7. (Indicated by a dashed-dotted arrow line B2 in FIG. 1 (a) and FIG. 3).

  Specifically, the lower end port 7 a of the mud pipe 7 is opened to the upper surface wall 3 a of the chamber 3. The upper surface wall 3a of the chamber 3 is formed in a cylindrical shape that is squeezed from the filtration layer 4 side toward the lower end port 7a, and the exfoliated sludge and air bubbles raised from above the filtration layer 4 are separated from the lower end port 7a. It is gathered towards. By this aggregation, the air lift of the exfoliated sludge into the uplift pipe 7 is efficiently performed.

  The upper end 7b of the mud pipe 7 is connected to a steam separator 27 provided above the reference water level WL. The air supply required for the air lift, that is, the air supply to the air supply pipe 6a, is performed with the reference water level WL (natural water level) due to the water to be treated which has been transferred to the chamber 3 in the mud pipe 7 while the air diffuser 6 is stopped. Therefore, it is determined by the height (lift) from the reference water level WL of the steam separator 27.

  The outlet of the steam separator 27 is connected to a transfer pipe 28 that is piped up to above the separation filter bed tank 12. As a result, the separated sludge that has been air-lifted into the mud pipe 7 is returned to the separation filter bed 12 together with the treated water that has been air-lifted simultaneously (indicated by a one-dot chain line in FIG. 1 (a)). B3).

  The return of the exfoliated sludge is to send the water to be treated and the exfoliated sludge to the treatment tank upstream of the aerobic treatment tank 14 for convenience of denitrification. The air-lifted exfoliated sludge may be discharged from the mud pipe 7, and this discharge mode can be appropriately changed according to the presence or absence of the denitrification process and the installation mode of the treatment tank.

  On the other hand, the treated water from which the separated sludge has been separated in the chamber 3 is transferred to the disinfection tank 15 as described above, and finally discharged as treated water from the outlet 29 of the tank body 11 (FIG. 1 (a ) As indicated by arrow A8). Depending on the discharge flow rate, the air lifted exfoliated sludge and the amount of water to be treated, new water to be treated is supplied into the chamber 3 from the aerobic treatment tank 14 through the advection port 2.

  In the first embodiment, the separation sludge separation device 1 is provided in the carrier flow / biological filtration type sewage septic tank 10, but the contact aeration circulation type sewage septic tank is provided by connecting the drain port 5 to the settling tank. A separation sludge separation apparatus 1 can also be provided.

  In the first embodiment, as described above, the chamber 3 is provided with a smaller capacity than the conventional filtration chamber, and so to speak, the air lift pump and the filtration chamber are integrated, so that the chamber 3 is anaerobic. The structure provided in the processing layer 13 and the aerobic processing tank 14 so that attachment or detachment was possible can be implement | achieved easily.

(Second Embodiment)
As an example, a second embodiment of the present invention will be described with reference to FIG. Hereinafter, differences from the first embodiment will be mainly described, and the same configurations as those of the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

  In the exfoliated sludge separation device 30 and the sewage purification tank 40 according to the second embodiment, the tank body 11 has an opening / closing port 41 above the exfoliating sludge separation device 30, and the exfoliation sludge separation device 30 is detachable from the opening / closing port 41. Is provided.

  Specifically, the separation sludge separation device 30 includes a chamber 31 and a mud pipe 7 installed in an aerobic treatment tank 42. The chamber 31 includes an upper step portion 31a to which the mud pipe 7 is connected, a middle step portion 31b in which the advection port 2 is formed and the filtration layer 4 (not shown) is installed, and a lower step portion 31c in which the aeration unit 6 is installed. And each step portion is detachable.

  A drainage port 32 is formed in the lower step portion 31c from a rising pipe that also serves as a transfer path to the downstream side. The flange portion 33 provided on the rising pipe is detachably connected to the medicine cylinder 43. Further, the lower stage portion 31c is provided with a connector (not shown) for the air supply pipe 6a and the air diffusion portion 6. Note that the air supply pipe 6 a can be piped through the drain port 32.

  The outlet of the steam separator 27 is detachably connected to the transfer pipe 28 by the flange portion 34.

  The chamber 31 is provided below the opening / closing port 41 with a narrower width. Thereby, the separation sludge separation apparatus 30 can be taken in and out from the opening / closing port 41 until the chamber 31 comes into contact with the tank body 44. The flange portions 33 and 34 are disposed below the opening / closing port 41, and can be connected / disconnected from the opening / closing port 41. Therefore, the peeling sludge separation device 30 is pulled out from the aerobic treatment tank 42 by opening the opening / closing port 41 and removing the flange portions 33 and 34 at the time of cleaning or the like, and in the aerobic treatment tank 42 in the reverse procedure. Can be installed.

(A) The schematic longitudinal cross-sectional view which shows typically the schematic whole structure of the peeling sludge separation apparatus which concerns on 1st Embodiment of this invention, and a wastewater septic tank, (b) The outline whole structure seen from the bb line | wire of (a) Schematic cross-sectional view schematically showing The perspective view which shows the peeling sludge separation apparatus which concerns on 1st Embodiment of FIG. The front view which shows typically the peeling sludge separation apparatus which concerns on 1st Embodiment of FIG. Schematic partial longitudinal sectional view schematically showing main parts of a separation sludge separation apparatus and a sewage septic tank according to a second embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,30 Peeling sludge separation apparatus 2 Advection port 3,31 Chamber 4 Filtration layer 5,32 Drainage port 6 Aeration part 6a Air supply pipe 7 Pumping mud pipe 7a Lower end port 10,40 Sewage septic tank 11,44 Tank body 14,42 Good Tempering tank 41 Opening and closing port

Claims (9)

  A chamber 3 having a transfer port 2 into which treated water mixed with exfoliated sludge can flow, a filtration layer 4 provided below the transfer port 2 in the chamber 3, and the filtration layer 4 of the chamber 3. A drainage port 5 formed below the filter layer 4, an air diffuser 6 provided below the filter layer 4, and a mud pipe 7 communicated in the chamber 3 above the filter layer 4. And the air diffuser 6 is provided so as to continuously perform air diffuser for washing the filtration layer 4, and the peeled sludge on the filter layer 4 is aired into the mud pipe 7 by this air diffuser. Peeling sludge separator to be lifted.   The exfoliation sludge separation device according to claim 1 in which aeration of said diffuser 6 is performed regularly.   The exfoliated sludge separation apparatus according to claim 1 or 2, wherein the chamber (3) has a cylindrical shape that is squeezed from the filtration layer (4) side toward a lower end (7a) of the mud pipe (7).   The separation sludge separation apparatus according to any one of claims 1 to 3, wherein the filter medium of the filter layer 4 is provided so as to keep a settling state against the air diffused by the air diffuser 6.   The exfoliation sludge separation device according to any one of claims 1 to 4, wherein the filter medium of the filter layer 4 is made of granular wheatstone.   The separation sludge separation apparatus 1 according to any one of claims 1 to 5 is provided in a tank body 11 in which an aerobic treatment tank 14 is formed by a partition wall 22, and the advection port 2 communicates with the aerobic treatment tank 14. Sewage septic tank.   The sewage septic tank according to claim 6, wherein the tank body (44) has an opening / closing port (41) above the separation sludge separation device (30), and the separation sludge separation device (30) is provided detachably from the opening / closing port (41).   The sewage septic tank according to claim 6, wherein the partition wall 22 has a concave portion 23 when viewed from above, and the separated sludge separation device 1 is disposed in the concave portion 23.   The sewage purification tank according to claim 8, wherein the concave portion 23 is partitioned so as to form a transfer channel between the drain port 5 and the downstream processing tank 15.

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