Wastewater treatment unit, purification device, and purification method

Abstract

In a wastewater treatment unit with a structure in which a microbial carrier is supported by a support material, the purification function of this carrier is efficiently utilized. [Solution] A wastewater treatment unit 100 for performing microbial reaction treatment on wastewater comprises a carrier 110 capable of holding microorganisms and a support material 120 having a plurality of openings 122 for supporting the carrier 110 from the lower side, and is configured so that the carrier 110 can be placed between the upper and lower support materials 120 when the support materials 120 are stacked. The carrier 110 has a plurality of through holes 113 that penetrate in the thickness direction.

Description

Technical Field

[0001] The present invention relates to a sewage treatment unit used for purifying sewage by microbial reaction. The present invention also relates to a purification apparatus provided with this sewage treatment unit in a microbial reaction tank where sewage is sprinkled, and a purification method using this sewage treatment unit.

Background Art

[0002] Conventionally, there are known the DHS (Downflow Hanging Sponge) method in which sewage is sprinkled into a treatment tank filled with a large number of carriers holding microorganisms, and the sewage is aerobically purified by the decomposition function of the microorganisms held by this carrier, and a purification apparatus (DHS reactor) for carrying out this method.

[0003] The applicant of the present application has proposed a technique for enabling uniform supply of sewage to the entire treatment tank even when the flow rate of sewage supplied to the purification apparatus is reduced (Patent Document 1). In Patent Document 1, for example, a dispersion member (sprinkler plate) is arranged at a position between the treatment tank and the sprinkler device where the sewage falling from the sprinkler device collides, and the sewage is dispersed by this dispersion member to widely disperse the sewage to the treatment tank.

[0004] Further, in Patent Document 2, a microbial immobilization carrier is proposed in which a plurality of carriers (porous bodies) for immobilizing microorganisms are inserted into, for example, a frame having a honeycomb structure, so that these carriers can be regularly arranged in the frame, and a plurality of frames filled with these carriers can be stacked in multiple stages.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] Incidentally, the microbial immobilization carrier described in Patent Document 2 has a structural problem in that the carriers are separated by frames, which hinders the flow of wastewater between adjacent carriers. In such a structure, where wastewater does not easily leach from one carrier to another, it becomes difficult to uniformly supply wastewater to all carriers held by the frames, resulting in the carrier's purification function not being utilized to its fullest potential. Furthermore, the structure in Patent Document 2 requires each carrier to be packed into the frame, which increases the effort required when starting to use the carrier or when refilling it.

[0007] Furthermore, in wastewater purification by microbial reactions, it is known that solid matter accumulates on the carrier due to the presence of solid matter in the wastewater and the reaction between microorganisms held on the carrier in the treatment tank and the wastewater. In the case of the microbial immobilization carrier described in Patent Document 2, if solid matter accumulates on the upper surface of the carrier, the introduction of wastewater into the carrier is hindered by the solid matter, causing the wastewater to slide sideways on the carrier. Ultimately, this raises concerns that the wastewater will either fall downward from outside the frame or be guided downward through the frame between the carriers without entering the carrier itself. In such cases, it becomes difficult to maximize the purification function of the carrier.

[0008] Therefore, the main objective of the present invention is to provide a technology that can efficiently utilize the purification function of a microbial carrier in a wastewater treatment unit structure in which a microbial carrier is supported by a support material. [Means for solving the problem]

[0009] The inventors of the present invention diligently studied means to solve the problems of the conventional invention described above, and as a result obtained the finding that by supporting a carrier capable of holding microorganisms from the bottom side with a support material, and by forming multiple through holes along the thickness direction of the carrier, the purification function of the carrier can be efficiently utilized. Based on the above finding, the inventors realized that the problems of the conventional invention could be solved, and completed the present invention. Specifically, the present invention has the following configuration or steps.

[0010] The first aspect of the present invention relates to a wastewater treatment unit 100. The wastewater treatment unit 100 is used to perform microbial reaction treatment on wastewater. The wastewater treatment unit 100 is intended to be used by arranging multiple units side by side in the left-right direction or stacking multiple units in the up-down direction. However, the first aspect of the present invention relates to the wastewater treatment unit 100 as a single unit. The wastewater treatment unit 100 comprises a carrier 110 and a support material 120. The carrier 110 is capable of holding microorganisms and is basically composed of a porous material such as a sponge. The support material 120 has multiple openings 122 formed therein and is a member used to support the carrier 110 from its lower side. The support materials 120 can be stacked in the up-down direction. Each support material 120 is configured so that the carrier 110 can be placed between the upper and lower support materials 120 when multiple units are stacked. Furthermore, the carrier 110 has multiple through holes 113 that penetrate in the thickness direction.

[0011] As described above, supporting the carrier 110 from below with the support material 120 makes it easier for wastewater to diffuse in the left-right direction of the carrier 110. Also, since it is only necessary to place, for example, a flatly spread carrier 110 on top of the support material 120, the work of placing the carrier 110 on the support material 120 becomes easier when discontinuing use or replacing the carrier 110. Furthermore, by forming through holes 113 in the carrier 110, the surface area of ​​the carrier 110 is increased and the flow of air and water is improved, thereby increasing the reaction efficiency of the microorganisms held in the carrier 110. Moreover, even if solid matter accumulates on the upper surface of the carrier 110, the formation of through holes 113 in the carrier 110 makes it easier for wastewater to be introduced into the interior of the carrier 110.Therefore, the wastewater treatment unit 100 according to the present invention makes it possible to efficiently utilize the purification function of the carrier 110.

[0012] In the wastewater treatment unit 100 according to the present invention, it is preferable that, when the carrier 110 is placed on the support material 120, the through-hole 113 of the carrier 110 communicates with the opening 122 of the support material 120. That is, "communication" between the through-hole 113 and the opening 122 means that, in a plan view, the positions of the through-hole 113 of the carrier 110 and the opening 122 of the support material 120 overlap. In this way, when the carrier 110 is placed on the support material 120, the through-hole 113 and the opening 122 communicate in the vertical direction, thereby ensuring the flow of air and water.

[0013] In the wastewater treatment unit 100 according to the present invention, it is preferable that the carrier 110 has a plurality of protrusions 115 surrounded by grooves 114 on its lower surface. In this case, it is preferable that the protrusions 115 of the carrier 110 fit into the openings 122 of the support material 120. By forming protrusions 115 that fit into the openings 122 of the support material 120 on the lower surface of the carrier 110 in this way, it becomes easier to position the carrier 110 when placing it on the support material 120, and the carrier 110 is less likely to shift position on the support material 120, thereby improving stability.

[0014] In the wastewater treatment unit 100 according to the present invention, it is preferable that when the protrusion 115 of the carrier 110 is fitted into the opening 122 of the support material 120, the apex (lower end side) of the protrusion 115 protrudes from the lower surface of the support material 120. By configuring the carrier 110 so that the lower end apex of the protrusion 115 protrudes downward from the support material 120, wastewater seeping from the lower end of the carrier 110 is more likely to land on another carrier 110 further below. In other words, if the carrier 110 is simply resting on the frame portion 121 of the support material 120 (where part of the carrier 110 does not protrude from the lower surface of the support material 120), there is a concern that wastewater seeping from the lower end of the carrier 110 may travel along the frame portion 121 of the support material 120 and land in a place where there is no carrier 110. In this regard, by configuring it as described above, wastewater can be effectively guided from the upper carrier 110 to the lower carrier 110.

[0015] In the wastewater treatment unit 100 according to the present invention, it is preferable that at least one of the multiple protrusions 115 of the carrier 110 has the aforementioned through-holes 113 formed therein. By forming through-holes 113 in the protrusions 115 in this way, the flow of air and water can be further improved.

[0016] In the wastewater treatment unit 100 according to the present invention, it is preferable that the support material 120 has a plurality of legs 123 extending downward therefrom and leg receiving portions 124 for supporting the legs 123 of other support materials 120 stacked above it. In this case, it is preferable that the carrier 110 has a cutout portion 116 formed therein to prevent contact with the legs 123 of other support materials 120. By providing legs 123 and leg receiving portions 124 on each support material 120 in this way, it becomes easier to stack multiple support materials 120 in the vertical direction while maintaining space between the upper and lower support materials 120. Furthermore, by forming a cutout portion 116 on the carrier 110 to avoid the legs 123 of the support materials 120, it is possible to suppress liquid seeping from the carrier 110 from flowing downward along the legs 123. In other words, if the liquid seeping from the carrier 110 flows downward along the legs 123, the liquid may concentrate locally only at the part of the carrier 110 that is in contact with the legs 123, potentially preventing the efficient utilization of the carrier 110's purification function. This situation can be avoided by configuring the device as described above.

[0017] In the wastewater treatment unit 100 according to the present invention, it is preferable that the length of the legs 123 of the support material 120 is longer than the thickness of the carrier 110. This allows a gap C to be created between the carrier 110 and other support materials 120 stacked above it when the carrier 110 is placed on the support material 120. When the carrier 110 and other support materials 120 above it are in close contact, it becomes difficult to supply air such as oxygen to the carrier 110. However, by providing a gap between the carrier 110 and the support material 120, a ventilation passage is created between the upper carrier 110 and the lower carrier 110, allowing air such as oxygen to be efficiently supplied to the unit 100.

[0018] In the wastewater treatment unit 100 according to the present invention, the support material 120 may have a plurality of protrusions 126 that are lower in height than the legs 123. By providing such protrusions 126 on the support material 120, the wastewater flowing along the frame 121 of the support material 120 can be made to fall downward at the locations where the protrusions 126 are formed, rather than from the legs 123. If the wastewater flows downward along the legs 123 of the support material 120, the wastewater will concentrate around the legs 123, making it difficult to distribute the wastewater throughout the carrier 110. On the other hand, by providing a plurality of protrusions 126 that are lower in height than the legs 123 on the lower surface of the support material 120, the wastewater will accumulate around the protrusions 126 and fall downward, thus improving the wastewater dispersion effect compared to when there are no protrusions 126.

[0019] In the wastewater treatment unit 100 according to the present invention, the support material 120 is preferably formed in a grid or honeycomb shape. A grid shape means a structure in which openings 122 of the same shape are formed regularly, and the shape of the openings 122 is triangular, quadrilateral, or other polygonal. A honeycomb shape means a structure in which openings 122 of the same shape are formed regularly, and in particular the shape of the openings 122 is hexagonal. By making the support material 120 in a grid or honeycomb shape in this way, the shape of the carrier 110 can be made uniform and easy to manufacture.

[0020] A second aspect of the present invention relates to a sprinkler-type purification device 1 for performing microbial reaction treatment on wastewater. The purification device 1 according to the present invention comprises a treatment tank 10 and a sprinkler device 20. Multiple wastewater treatment units 100 relating to the first aspect described above are arranged in the treatment tank 10. The sprinkler device 20 sprinkles wastewater from above the treatment tank 10.

[0021] The third aspect of the present invention relates to a spraying type purification method for performing microbial reaction treatment on sewage. The purification method according to the present invention first supplies sewage to the treatment tank 10 (first step). A plurality of sewage treatment units 100 according to the aforementioned first aspect are arranged in this treatment tank 10. Further, in this treatment tank 10, microbial reaction treatment is performed on the sewage by the sewage treatment unit 100 holding microorganisms (second step).

Effect of the Invention

[0022] According to the present invention, in a sewage treatment unit having a structure in which a microorganism holding carrier is supported by a support material, the purification function of this carrier can be efficiently utilized.

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is a schematic diagram showing an embodiment of the purification apparatus. [Figure 2] FIG. 2 is an exploded perspective view showing an embodiment of the sewage treatment unit. [Figure 3] FIG. 3 shows a plan view of the carrier and an end view taken along line II-II. [Figure 4] FIG. 4 shows a bottom view of the carrier. [Figure 5] FIG. 5 shows a plan view of the support material. [Figure 6] FIG. 6 shows a side view of the sewage treatment unit in a state where the carrier and the support material are combined. [Figure 7] FIG. 7 shows a side view of a state where the sewage treatment units are stacked in three stages. [Figure 8] FIG. 8 shows a modified example in which protrusions are formed on the support material.

Mode for Carrying Out the Invention

[0024] Hereinafter, embodiments for carrying out the present invention will be described using the drawings. The present invention is not limited to the embodiments described below and includes those appropriately modified by those skilled in the art within an obvious range from the following embodiments. In this specification, "A to B" means "A or greater and B or less". The drawing also includes three-dimensional coordinate axes (XYZ). The X-axis represents the left-right direction (horizontal direction) of the wastewater treatment unit 100, the Y-axis represents the depth direction (vertical direction) of the wastewater treatment unit 100, and the Z-axis represents the up-down direction (height direction) of the wastewater treatment unit 100.

[0025] Figure 1 shows a wastewater treatment device 1 according to one embodiment of the present invention. The wastewater treatment device 1 of this embodiment is used, for example, as part of an organic wastewater treatment device. The wastewater treatment device 1 purifies wastewater that has been anaerobically treated by, for example, an Up-flow Anaerobic Sludge Blanket (UASB) reactor, by aerobic biological treatment. Specifically, the wastewater treatment device 1 sprays wastewater supplied from a wastewater supply pipe onto a microbial carrier filled in a treatment tank, and uses the decomposition function of the microorganisms held by this carrier to aerobically purify the wastewater. As shown in Figure 1, the wastewater treatment device 1 comprises a treatment tank 10, a spraying device 20, a dispersion layer 30, and a water collection unit 40.

[0026] The treatment tank 10 is a tank filled with numerous carriers 110 that hold microorganisms, and wastewater is purified in this tank. The carriers 110 are supported by support materials 120, as will be described in more detail later, and the combination of these carriers 110 and support materials 120 constitutes a wastewater treatment unit 100. Multiple wastewater treatment units 100 are arranged in the left-right direction and stacked in multiple layers in the up-down direction within the treatment tank 10.

[0027] The material of the carrier 110 is not particularly limited, and known materials can be used as appropriate. The carrier 110 is preferably porous and water-retentive in order to increase the microbial retention density and ensure a hydrological residence time. For example, the carrier 110 can be made of a foamed resin such as polyurethane. Examples of microorganisms that can be retained on the carrier 110 include heterotrophic bacteria that aerobically oxidize dissolved substances, and autotrophic bacteria that aerobically oxidize ammonia, sulfurous odors (hydrogen sulfide, methyl sulfide, etc.), and methane.

[0028] Furthermore, the treatment tank 10 is installed on a stand (not shown). The treatment tank 10 also has a bottom plate 11 at the lower end of the internal space where the wastewater treatment unit 100 is located, and multiple liquid passage holes 11a are formed in this bottom plate 11. The wastewater that has passed through the wastewater treatment unit 100 of the treatment tank 10 is introduced into the water collection section 40 located below it through the liquid passage holes 11a in the bottom plate 11.

[0029] The sprinkler system 20 is positioned above the treatment tank 10 and sprinkles wastewater onto the treatment tank 10. While any known sprinkler system 20 can be used, it is preferable to use one disclosed in, for example, Patent Document 1 (Japanese Patent Application Publication No. 2018-167194). Specifically, the sprinkler system 20 receives wastewater from the outlet of the wastewater supply pipe 21 (header pipe) and sprinkles it. The sprinkler system 20 includes a receiving member 22, a drain pipe 23, a branch pipe 24, and a nozzle 25. In Figure 1, the drain pipe 23, branch pipe 24, and nozzle 25 are depicted as separate components, but they can also be constructed from a single component. The receiving member 22 is a trough-shaped member with an open top. The receiving member 22 receives wastewater flowing down from the outlet of the wastewater supply pipe 21 and supplies the wastewater to the drain pipe 23 through an insertion hole formed on its bottom surface. The drain pipe 23 is fixed to the receiving member 22 by being inserted through an insertion hole on the lower surface of the receiving member 22. The branch pipe 24 is connected to the lower end of the drain pipe 23 and is configured to slope downwards while branching the wastewater that has flowed through the drain pipe 23 toward multiple outlets. In the example shown in Figure 1, the sprinkler device 20 has two outlets, but the number of outlets is not limited to this and can be three, four, or more. The nozzles 25 are used to change the flow of wastewater discharged from the outlets and are attached to the ends of each branch pipe 24. By adjusting the direction and inclination of the nozzles 25, it is possible to adjust the direction of wastewater discharge, specifically the dripping position of the wastewater.

[0030] The dispersion layer 30 is positioned between the treatment tank 10 and the watering device 20. The dispersion layer 30 receives wastewater discharged from the watering device 20, temporarily holds it, and supplies it to the treatment tank 10 while dispersing the wastewater over a wide area from the point of dripping. The dispersion layer 30 is composed of foam 31. The foam 31 has a porous structure with countless micropores formed inside, and a network of fine tubes surrounding the micropores draws up the liquid by capillary action, holding the liquid within the micropores. Therefore, when wastewater is dripped onto the foam 31 from above, the wastewater diffuses three-dimensionally inside the foam 31 from the point of dripping. Furthermore, if wastewater continues to be dripped onto the foam 31, the wastewater already held inside the foam 31 is pushed down by the newly entering wastewater, and eventually separates from the bottom surface of the foam 31. In particular, when the carrier 110 in the treatment tank 10 is in contact with the lower surface of the foam 31, the wastewater in the foam 31 is absorbed by the carrier 110 in contact with it. By utilizing this phenomenon, the dispersion layer 30 widely and uniformly disperses the wastewater received from the sprinkler 20 onto the carrier 110 in the treatment tank 10.

[0031] Furthermore, in the present invention, the foam 31 is made of resin. The resin foam 31 is mainly obtained by a chemical foaming method in which a foaming agent and a base material are mixed, and the base material is foamed by generating gas through the decomposition of the foaming agent. Examples of resins that can be used as the base material include polyurethane (PUR) resins, polyethylene (PE) resins, polypropylene (PP) resins, polystyrene (PS) resins, and polyvinyl chloride (PVC) resins. In addition, one type of these resin may be used as the base material, or two or more types may be mixed and used. Among these, it is preferable to use a polyurethane resin for the foam 31. Examples of polyurethane resins include polyether polyurethane resins, polyester polyurethane resins, polycarbonate polyurethane resins, silicone polyurethane resins, acrylic polyurethane resins, and modified polyurethane resins. It is particularly preferable to use polyether polyurethane resins. The polyether-based polyurethane resin foam 31 has high durability and shock absorption, so its shape does not easily change even when wastewater is continuously dripped onto it over a long period of time, and the wastewater that falls onto its surface does not easily scatter, thus allowing for stable dispersion of wastewater. In addition, because the molecular structure of polyether-based polyurethane resin is relatively stable, it is resistant to wastewater and microorganisms.

[0032] The water collection section 40 collects the treated water (treated liquid) that has passed through the treatment tank 10 and discharges it to the outside. As mentioned above, the lower end of the treatment tank 10 is provided with a bottom plate 11 having a liquid passage hole 11a, and the treated water that has passed through this liquid passage hole 11a flows into the water collection section 40. The bottom surface of the water collection section 40 is shaped like a mortar, and a drain pipe 41 is provided at the lowest part of the bottom surface. Therefore, the treated water collected in the water collection section 40 is discharged to the outside through this drain pipe 41.

[0033] Figure 2 shows an exploded perspective view of the wastewater treatment unit 100, which is placed in the treatment tank 10. As shown in Figure 2, the wastewater treatment unit 100 consists of a carrier 110 and a support material 120. As mentioned above, the carrier 110 is a porous material such as a sponge for holding microorganisms and moisture. The support material 120 is a member for holding the carrier 110 from its underside. The wastewater treatment unit 100 is formed by placing the carrier 110 on top of this support material 120.

[0034] The structure of the carrier 110 is shown in the perspective view in Figure 2, the plan view in Figure 3, and the bottom view in Figure 4. Figure 3 also shows an end view of the carrier 110 along line II-II. As shown in Figures 2 to 4, the carrier 110 is basically a roughly rectangular shape that extends in the planar direction with a constant thickness, and has multiple through holes 113, grooves 114, and multiple defects 116 formed within it.

[0035] Specifically, the carrier 110 is divided into an upper half 111 located above and a lower half 112 located below in the vertical direction. Note that the upper half 111 and the lower half 112 are integrated and cannot be separated. Multiple through holes 113 are formed in the carrier 110, penetrating from the top surface to the bottom surface. That is, these through holes 113 are formed in both the upper half 111 and the lower half 112 of the carrier 110. These through holes 113 are arranged regularly in the planar direction (XY direction) of the carrier 110, and are provided at equal intervals in the left-right direction (X-axis direction) and the depth direction (Y-axis direction). These through holes 113 are formed at positions corresponding to the openings 122 of the support material 120, which will be described later, and it is generally preferable that the number of through holes 113 in the carrier 110 and the number of openings 122 in the support material 120 be the same.

[0036] By forming through-holes 113 in the carrier 110 in this way, the surface area of ​​the carrier 110 is increased, and the flow of air and water is improved, thereby increasing the reaction efficiency of the microorganisms held in the carrier 110. In a plan view, the area of ​​one through-hole 113 is, for example, 0.2 to 4 cm². 2It is preferable to do so, 0.3 to 2 cm 2 Or 0.5~1.4cm 2 It is particularly preferable to do so. Furthermore, in a plan view, the total area of ​​the through holes 113 is preferably 2 to 20% of the total area of ​​the carrier 110, and is particularly preferable to be 5 to 18% or 9 to 16%.

[0037] Furthermore, as shown in Figure 4, for example, a grid-like groove 114 is formed on the lower surface of the carrier 110. As shown in the end view in Figures 2 and 3, for example, this groove 114 is formed only in the lower half 112 of the carrier 110 and does not extend to the upper half 111. In other words, the area in which the groove 114 is formed is defined as the lower half 112, and the area not covered by the groove 114 is defined as the upper half 111. Thus, the groove 114 does not penetrate from the lower surface to the upper surface of the carrier 110, but is formed only from the lower surface to about the middle of the carrier 110. Because the grid-like groove 114 is formed in the lower half 112 of the carrier 110, the area enclosed by this groove 114 can be defined as a protrusion 115. That is, this protrusion 115 is a part that protrudes downward toward the carrier 110 relative to the part in which the groove 114 is formed. The protrusion 115 formed on the lower half 112 of the carrier 110 becomes the part into which the opening 122 of the support material 120, which will be described later, fits. In other words, the frame portion 121 of the support material 120, which will be described later, is inserted into the groove 114 of the lower half 112 of the carrier 110.

[0038] Furthermore, as shown in Figure 4, the through holes 113 of the carrier 110 are basically formed in the lower half 112 at positions corresponding to the protrusions 115. In other words, one through hole 113 is formed for each protrusion 115, and it is formed approximately in the center of the protrusion 115. Thus, it is preferable to form one through hole 113 for each protrusion 115.

[0039] Furthermore, as shown in Figures 2 to 4, the carrier 110 has multiple defects 116 formed in it. These defects 116, like the through holes 113, are portions that penetrate from the top surface to the bottom surface of the carrier 110. However, the defects 116 are not limited to holes formed inside the carrier 110, but also include notches formed on the periphery and corners of the carrier 110. These defects 116 generally have a larger area than the aforementioned through holes 113. These defects 116 are formed to prevent direct contact between the support material 120's legs 123 and the carrier 110. For this reason, the defects 116 are formed at positions corresponding to the support material 120's legs 123, and it is generally preferable that the number of defects 116 in the carrier 110 and the number of legs 123 in the support material 120 be the same.

[0040] The structure of the support material 120 is shown in the perspective view of Figure 2 and the plan view of Figure 5. As shown in these figures, the support material 120 has a grid-like frame portion 121 on which the carrier 110 can be placed. Specifically, the frame portion 121 has regularly spaced rectangular openings 122 in the planar direction (XY direction), and these openings 122 are arranged at equal intervals in the left-right direction (X-axis direction) and the depth direction (Y-axis direction). The protrusions 115 of the carrier 110, which are also formed in a rectangular shape, can be fitted into the openings 122 of the frame portion 121. In other words, the grid-like frame portion 121 can be inserted into the grooves 114 of the carrier 110, which are also formed in a grid shape. Thus, when placing the carrier 110 on the support material 120, the protrusions 115 of the carrier 110 are fitted into the openings 122 of the support material 120. As a result, the carrier 110 is stably supported by the support material 120.

[0041] Furthermore, as shown in Figure 2, the support material 120 is provided with a plurality of legs 123 extending downward. Multiple support materials 120 can be stacked vertically, but in this case, it is necessary to secure space between the upper and lower support materials 120 to place the carrier 110. For this reason, the support material 120 is provided with legs 123 to secure such space for placing the carrier 110. The plurality of legs 123 should be provided at equal intervals in the left-right direction (X-axis direction) and the depth direction (Y-axis direction). If the spacing between the legs 123 is too wide, the frame 121 may partially bend under the weight of the carrier 110, and there is a risk that wastewater may concentrate and flow into the bent area. For this reason, in order to suppress the bending of the frame 121, the spacing between the legs 123 is preferably about 50 to 200 mm, and particularly preferably 60 to 180 mm or 80 to 160 mm.

[0042] Furthermore, it is preferable to provide the legs 123 not only around the periphery of the frame 121 but also in the middle of the frame 121. This prevents the center of the frame 121 from bending significantly downward when the support material 120 supports the carrier 110. In the illustrated example, the support material 120 is provided with a total of 16 legs 123, of which 12 legs 123 are provided along the periphery of the support material 120, while the remaining 4 are provided in the middle of the support material 120. If we consider a square area with 4 legs 123 at the four corners as one section, then in the illustrated example, a total of 9 sections (3 x 3) can be considered to be formed.

[0043] Furthermore, the support member 120 has a leg support portion 124 directly above the leg portion 123. The leg support portion 124 is formed to close off a part of the opening 122 in the lattice-shaped frame portion 121, and this opening 122 does not exist at the position where the leg support portion 124 is provided. When stacking multiple support members 120, the leg support portion 124 of the support member 120 rests on the leg portion 123 of the other support member 120 located above it. In this way, by receiving the leg portion 123 of the upper support member 120 with the leg support portion 124 of the lower support member 120, multiple support members 120 can be stacked vertically. In addition, the leg support portion 124 may have a leg support groove 125 into which the lower end of the leg portion 123 fits. By providing such a leg support groove 125, it is possible to prevent the leg portion 123 from shifting on the leg support portion 124 or from falling off the leg portion 124 when the leg portion 123 is placed on the leg support portion 124.

[0044] The material used to form the support material 120 is preferably one that can be used for a long period of time in water treatment and has a certain rigidity so as to suppress deflection when supporting the carrier 110. For example, the support material 120 may be made of a resin such as polypropylene, or it may be made of a metal such as stainless steel. It is preferable that the amount of deflection of the support material 120 when supporting the carrier 110 is small. For example, when the carrier 110, which is completely filled with water, is placed on the support material 120, the amount of deflection of the support material 120 is preferably 3 mm or less at the position between the legs 123 where the amount of deflection is greatest, and particularly preferably 1 mm or less.

[0045] Figure 6 shows a side view of the wastewater treatment unit 100 with the carrier 110 and support material 120 combined. As described above, the carrier 110 and support material 120 are combined by fitting the protrusion 115 on the lower surface of the carrier 110 into the opening 122 of the support material 120. As shown in Figure 6, when the protrusion 115 is fully fitted into the opening 122, it is preferable that the protrusion 115 of the carrier 110 protrudes from the lower surface of the support material 120. In Figure 6, the protrusion length of the protrusion 115 of the carrier 110 extending from the lower surface of the support material 120 is indicated by the symbol P. The protrusion length P is the length from the lower surface of the support material 120 to the top of the protrusion 115 of the carrier 110. That is, the protrusion length P is determined by the difference between the height of the protrusion 115 of the carrier 110 and the thickness of the frame portion 121 of the support material 120. The protruding length P should be 1 mm or more, preferably 1 to 20 mm, and particularly preferably 5 to 15 mm.

[0046] Figure 7 shows a side view of a wastewater treatment unit 100 stacked in multiple layers. In the example shown in Figure 7, the wastewater treatment units 100 are stacked in three layers. As shown in Figure 7, there is a gap C between the carrier 110 supported by the lower support material 120 and the carrier 110 supported by the upper support material 120. In other words, the thickness of the carrier 110, the length of the legs 123, and the protruding length P (see Figure 6) of the convex portion 115 of the carrier 110 are adjusted so that the upper and lower carriers 110 do not come into direct contact with each other even when the wastewater treatment units 100 are stacked vertically. Specifically, the height of the gap C between the upper and lower carriers 110 is preferably at least 3 mm, and particularly preferably 5 to 30 mm or 10 to 25 mm. If the gap C between the upper and lower carriers 110 is less than 3 mm in the initial state, solid matter such as organisms will accumulate between the carriers 110 as wastewater treatment progresses, filling the gap C. Therefore, it is preferable to ensure that the gap C is 3 mm or larger in the initial state. On the other hand, if the gap C exceeds 30 mm, it means that the legs 123 of the support material 120 are too long relative to the thickness of the carrier 110. Designing the legs 123 to be long would unnecessarily increase the manufacturing cost of the wastewater treatment unit 100, so it is appropriate to keep the gap C at 30 mm or less. For example, it is preferable that the length of the legs 123 of the support material 120 be +5 to 25 mm or +10 to 20 mm relative to the thickness of the carrier 110.

[0047] Figure 8 shows a modified version of the support material 120. As shown in Figure 8, the modified support material 120 has a projection 126 formed on the lower surface of the frame portion 121. This projection 126 is at least lower in height in the vertical direction than the leg portion 123. If water slides sideways along the lower surface of the support material 120, it may hinder the even distribution of water within the carrier 110. However, by providing such a projection 126 on the lower surface of the frame portion 121, it is possible to prevent water from flowing sideways beyond this projection 126. In other words, this projection 126 becomes the lowest point, and water drips downward from this projection 126.

[0048] The vertical height of the projection 126 should be at least 1 mm, for example, 1 to 5 mm or 1 to 3 mm. The horizontal length (diameter) of the projection 126 should be, for example, 1 to 10 mm. The shape of the projection 126 may be hemispherical (semicircular cross-section) as illustrated in Figure 8, or it may be a prism, cylinder, pyramidal or conical shape.

[0049] Furthermore, it is preferable to provide one or more protrusions 126 between the legs 123. For example, as shown in the example in Figure 2, when a total of 16 legs 123 are provided on the support material 120, if we consider a square area with four legs 123 at the four corners as one section, then a total of 9 sections (3 x 3) can be formed. When assuming that one section is formed by four legs 123 in this way, it is preferable to provide at least one or more protrusions 126 in each section. It is also possible to provide, for example, 2 to 5 protrusions 126 in one section. In addition, it is also possible to provide protrusions 126 at all the intersections of the grid that constitutes the frame section 121.

[0050] In this specification, embodiments of the present invention have been described with reference to the drawings in order to express the content of the present invention. However, the present invention is not limited to the above embodiments, and includes modifications and improvements that are obvious to those skilled in the art based on the matters described in this specification.

[0051] For example, in the illustrated example, the frame portion 121 of the support material 120 has a square grid shape with square openings 122. However, it is not limited to this, and it is also possible to make it honeycomb-shaped with regular hexagonal openings 122. In this case, the shape of the grooves 114 formed on the lower surface of the carrier 110 will also be honeycomb-shaped to match the shape of the frame portion 121 of the support material 120. In addition, the shape of the convex portion 115 surrounded by the grooves 114 on the lower surface of the carrier 110 will be a regular hexagon.

[0052] Furthermore, the wastewater treatment unit 100 may be fixed to other wastewater treatment units 100 adjacent to it in the planar direction (XY direction) by fixing means. As a fixing means in the planar direction, for example, the legs 123 of the support material 120 of adjacent wastewater treatment units 100 on the left and right may be fixed with adhesive, or fixed with tape or string. Alternatively, as a fixing means in the planar direction, the legs 123 of the support material 120 of adjacent wastewater treatment units 100 on the left and right may be fixed with a removable metal fitting or the like.

[0053] Furthermore, the wastewater treatment unit 100 may be fixed to other wastewater treatment units 100 stacked in the vertical direction (Z direction) by fixing means. As a fixing means in the vertical direction, for example, holes may be made in the legs 123 of the support members 120 of vertically adjacent wastewater treatment units 100, and connecting pieces with locking members fixed to the support member 120 directly below may be inserted into the holes in each leg 123 to fix the upper and lower support members 120 so that they do not move. [Explanation of Symbols]

[0054] 1...Purification device 10...Treatment tank 11...Bottom plate 11a...Liquid hole 20... Sprinkler system 21... Sewage supply pipe 22...Receiving member 23...Drain pipe 24... Branch pipe 25... Nozzle 30...Dispersed layer 31...Foam 40...Water collection part 41...Drain pipe 100...Wastewater treatment unit 110...Carrier 111...Upper half 112...Lower half 113...Through hole 114...Groove 115...Convex part 116...Defective part 120...Support material 121...Frame 122...Opening 123...Legs 124...Leg holder 125...Leg holder groove 126…Protrusion P...Projection length C...Gap

Claims

1. A wastewater treatment unit for performing microbial reaction treatment on wastewater, A carrier capable of holding microorganisms, The support material, having multiple openings formed therein, is provided for supporting the carrier from the lower side. The support materials are stacked and configured so that the carrier can be placed between the upper and lower support materials. The carrier has a plurality of through holes that penetrate in the thickness direction. Wastewater treatment unit.

2. When the carrier is placed on the support material, the through-hole of the carrier communicates with the opening of the support material. The wastewater treatment unit according to claim 1.

3. The carrier has a plurality of protrusions on its lower surface that are surrounded by grooves. The protrusion of the carrier fits into the opening of the support material. The wastewater treatment unit according to claim 1.

4. In the state in which the protrusion of the carrier is fitted into the opening of the support material, the apex of the protrusion protrudes from the lower surface of the support material. The wastewater treatment unit according to claim 3.

5. The through-hole is formed in at least one of the multiple protrusions. The wastewater treatment unit according to claim 3.

6. The aforementioned support material is It has multiple legs extending downwards, It has a leg support section for placing the legs of other support materials stacked on top of it. The carrier has a defect formed in it so as not to come into contact with the legs of the other support material. The wastewater treatment unit according to claim 1.

7. The aforementioned support material is It has multiple legs extending downwards, It has a leg support section for placing the legs of other support materials stacked on top of it. The length of the legs of the support material is longer than the thickness of the carrier. When the carrier is placed on the support material, a gap is created between the carrier and other support materials stacked above it. The wastewater treatment unit according to claim 1.

8. The aforementioned support material is It has multiple legs extending downwards, Above it is a leg support for placing the legs of other support materials stacked on top of it, Its lower surface has multiple protrusions that are lower in height than the aforementioned legs. The wastewater treatment unit according to claim 1.

9. The support material is formed in a grid or honeycomb shape. The wastewater treatment unit according to claim 1.

10. A water-sprinkling type purification device for treating wastewater with microbial reactions, A treatment tank in which a plurality of wastewater treatment units according to claim 1 are arranged, The treatment tank is equipped with a sprinkler system for spraying wastewater from above. Purification device.

11. A water-spraying type purification method that performs microbial reaction treatment on wastewater, A step of supplying wastewater to a treatment tank in which a plurality of wastewater treatment units according to claim 1 are arranged, The process includes a step in which the wastewater is subjected to a microbial reaction treatment in the treatment tank using the wastewater treatment unit that retains microorganisms. Purification methods.

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