Separation device, catch basin, and separation method

Abstract

To provide a separation device capable of achieving alleviation of a maintenance burden by capturing fragments of a synthetic resin.SOLUTION: A separation device that is installed in a catch basin and separates fragments of a synthetic resin from drainage water containing the fragments of the synthetic resin includes a partition wall and an elbow. The partition wall includes: a first end part configured to be brought into contact with a bottom face of the catch basin; a second end part configured to be brought into contact with a sidewall of the catch basin and intersecting the first end part; a third end part configured to be brought into contact with the sidewall of the catch basin, intersecting the first end part, and facing the second end part; and a connection hole. In the elbow, an outflow side opening part is coupled to the connection hole, and an inflow side opening part is directed in a direction of the first end part. A first distance defined below is larger than a second distance defined below: the first distance being a distance from the first end part to a part nearest to the first end part in a peripheral part of the connection hole and the second distance being a distance from the first end part to the inflow side opening part of the elbow.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a separation device, a catch basin, and a separation method. [Background technology]

[0002] In recent years, microplastics flowing into the ocean have become a problem. When artificial turf is used in sports facilities, parts of the artificial turf break off and become fragments as the facility is used, and these fragments are discharged outside the facility along with wastewater. For this reason, fragments of artificial turf are cited as one of the causes of microplastics flowing into the ocean. Therefore, filters are being installed in the drainage system of sports facilities to separate the fragments of artificial turf from the wastewater.

[0003] For example, Patent Document 1 discloses a storage and drainage structure comprising a gutter provided around a playground, a storage tank which collects rainwater that flows into the gutter, a removable filter provided below the storage tank which divides the internal space of the storage tank into a storage space section and a drainage space section below the storage space section on a horizontal plane perpendicular to the vertical direction, and which filters the rainwater, a first drainage section provided in the drainage space section, and a second drainage section provided below the gutter and above the storage space section. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-57057 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology of Patent Document 1, when wastewater containing artificial turf fragments flows into the storage and drainage structure, the artificial turf fragments are separated from the wastewater by a filter, but the filter may become clogged with the artificial turf fragments that are separated in a short period of time, requiring frequent cleaning of the filter. For this reason, there is a demand for reducing the maintenance burden. [Means for solving the problem]

[0006] The separation device of the present disclosure is a separation device that is installed in a catch basin and separates synthetic resin fragments from wastewater containing the fragments of synthetic resin, and comprises a partition wall and an elbow, the partition wall having a first end configured to contact the bottom surface of the catch basin, a second end configured to contact the side wall of the catch basin and intersecting the first end, a third end configured to contact the side wall of the catch basin, intersecting the first end and facing the second end, and a connection hole, and is a partition wall for separating the wastewater from the wastewater from which the synthetic resin fragments have been separated, and an elbow whose outlet side opening portion is connected to the connection hole and whose inlet side opening portion is bent and extends toward the first end, and the first distance defined below is greater than the second distance defined below. First distance: the distance from the first end to the portion of the periphery of the connection hole that is closest to the first end Second distance: the distance from the first end to the inlet opening of the elbow

[0007] The present disclosure can be realized not only as a separation device having the above-mentioned characteristic configuration, but also as a catch basin equipped with the above-mentioned separation device, and a separation method using a catch basin equipped with the above-mentioned separation device. Effect of the Invention

[0008] According to the present disclosure, it is possible to reduce the maintenance burden. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of an outline of drainage equipment for an exercise facility. [Diagram 2] FIG. 2 is a schematic diagram showing an example of the outline of a catch basin according to the first embodiment. [Diagram 3] FIG. 2 is a perspective view of an example of a separation device according to the first embodiment. [Figure 4] 1 is a cross-sectional view of a separation device according to a first embodiment. [Diagram 5] FIG. 2 is a perspective view showing an aspect of installing the separation device according to the first embodiment in a catch basin. [Figure 6] FIG. 13 is a schematic diagram showing an example of the state of a catch basin when wastewater flows in. [Figure 7] FIG. 13 is a schematic diagram showing an example of a method for cleaning a catch basin. [Figure 8] FIG. 11 is a cross-sectional view showing an example of a separation device according to a second embodiment. [Figure 9] FIG. 11 is a perspective view of an example of a separating device according to a third embodiment, seen from the side where an elbow is located. [Figure 10] FIG. 11 is a perspective view of an example of a separation device according to a fourth embodiment, seen from the side where an elbow is located. [Figure 11] FIG. 11 is a perspective view of an example of a separation device according to a fifth embodiment, seen from the side where an elbow is located. [Figure 12] FIG. 13 is a perspective view showing an example of a separation device according to a sixth embodiment. [Figure 13] FIG. 13 is a perspective view showing an example of a separation device according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Overview of the embodiment of the present disclosure> Below, an overview of the embodiments of the present disclosure will be listed and described.

[0011] (1) The separation device of the present disclosure is a separation device that is installed in a catch basin and separates synthetic resin fragments from wastewater containing the fragments, comprising a partition wall and an elbow, the partition wall having a first end configured to contact the bottom surface of the catch basin, a second end configured to contact a side wall of the catch basin and intersecting the first end, a third end configured to contact the side wall of the catch basin and intersecting the first end and facing the second end, and a connecting hole, the elbow has an outlet side opening portion connected to the connecting hole and an inlet side opening portion facing the first end, and the first distance defined below is greater than the second distance defined below. First distance: the distance from the first end to the portion of the periphery of the connection hole that is closest to the first end. Second distance: The distance from the first end to the inlet opening of the elbow. This makes it possible to reduce the maintenance burden.

[0012] (2) In the above (1), the second end and the third end of the partition wall may be bent toward the opposite side to the elbow, thereby enabling the separation device to be installed in catch basins of various sizes.

[0013] (3) In the above (2), the partition may have a fourth end defined below bent toward the opposite side to the elbow. Fourth end: An end configured to contact a side wall of the catch basin and opposite to the first end. As a result, even if a large amount of wastewater flows into the catch basin so that the separation device is submerged, the wastewater containing synthetic resin fragments is prevented from flowing out.

[0014] (4) In the above (2), a water-permeable material may be provided in the portion of the partition wall from the first end to the third end that contacts the catch basin. This prevents wastewater from accumulating in the catch basin even when wastewater does not flow into the catch basin for a long period of time, thereby suppressing the occurrence of mosquito larvae and the like.

[0015] (5) In the above (1), the elbow may include a first filter connected to an inlet opening of the elbow, which further prevents fragments of synthetic resin separated from the wastewater from flowing out to the downstream side of the catch basin.

[0016] (6) In the above (5), the elbow may include an extension pipe disposed inside the first filter and extending from the inlet opening in a direction approaching the first end to a position spaced a predetermined distance from the first end, thereby enabling soil and sand that accumulates at the bottom of the first filter to be discharged.

[0017] (7) In the above (1), the elbow may further include a branch pipe branching off from the elbow and extending to an opposite side to the first end, and a second filter connected to an inlet opening of the branch pipe, thereby making it possible to separate synthetic resin fragments from a larger amount of wastewater.

[0018] (8) In the above item (1), the partition wall may have an overflow end portion on a side opposite to the first end portion, the overflow end portion being configured to open to a side wall of the catchment basin. This prevents wastewater from overflowing from the catchment basin even when a large amount of wastewater flows into the catchment basin.

[0019] (9) In the above (8), the partition may be provided at the overflow end with a first inclined plate inclined toward the first end in a direction away from the partition, thereby preventing fragments of synthetic resin from flowing out even when overflowing wastewater flows out from the overflow end.

[0020] (10) In the above (9), the partition may be provided with a plurality of second inclined plates that are spaced apart from the first inclined plate in the vertical direction of the partition and are parallel to the first inclined plate. This further prevents synthetic resin fragments from flowing out even when overflowing wastewater flows out from the overflow end.

[0021] (11) In the above (8), the partition wall may further include a third filter extending from the overflow end in a direction away from the first end, thereby preventing fragments of synthetic resin from flowing out even when overflowing wastewater flows out from the overflow end.

[0022] (12) In the above (8), the separation device may further include an inner cover, the inner cover having an outer edge in contact with a side wall of the catch basin and configured to be located between the bottom surface and the upper end of the catch basin defined below, having a notch along the periphery of the overflow end, and being connected to the partition wall so that the notch and the overflow end are in contact with each other. Drain: A drain connected to the side wall of the catch basin, for guiding wastewater containing the synthetic resin fragments to the catch basin. This prevents the trapped synthetic resin fragments from flowing out even in the event of a large amount of wastewater flowing in and overflowing.

[0023] (13) In the above (12), the inner cover may have a waterway on the side where the elbow is located. The waterway has an inlet end configured to be connectable to an end of the drain groove and an outlet hole opening toward the elbow. This prevents the synthetic resin fragments that have been captured from flowing back.

[0024] (14) In a catch basin equipped with the separation device according to any one of (1) to (13) above, the side of the separation device with the elbow faces the side into which wastewater flows in the catch basin, and the side of the separation device opposite the side with the elbow faces the side into which wastewater flows out of the catch basin. This can reduce the maintenance burden.

[0025] (15) A method of separating synthetic resin fragments from wastewater containing the synthetic resin fragments according to the present disclosure includes the steps of: causing the wastewater to flow into the catch basin described in (14) above; separating the synthetic resin fragments from the wastewater by the catch basin; and draining the wastewater from which the synthetic resin fragments have been separated from the catch basin through a drain side opening of the catch basin. This can reduce the maintenance burden.

[0026] [Terminology definition] The definitions of terms used in this application are as follows: Artificial turf: A grass-like structure made from synthetic resins such as polyethylene and polypropylene. Used in sports facilities, homes, etc. Wastewater: Dirty water that is a mixture of dust and water. Dust is, for example, pieces of synthetic resin such as artificial turf. Water is, for example, rainwater. Elbow: A pipe bent in an L shape, for example at 90 degrees. Biofilm: A collection of microorganisms that form on a solid surface. The slimy, sticky substance that often forms on solid surfaces in water is an example of a biofilm.

[0027] <Embodiment 1> FIG. 1 is a perspective view showing an example of a general outline of a drainage system for a sports facility. The present disclosure will now be described with reference to the drawings.

[0028] [1-1. Overall configuration of drainage equipment] In recent years, artificial turf is widely used in sports stadiums and the like because it is more resistant to rain than natural turf and has low maintenance costs. Artificial turf is manufactured by making synthetic resins such as polypropylene and polyethylene to resemble the shape and color of grass. As shown in FIG. 1, an athletic facility 1 such as a soccer field has an artificial turf 2 laid in its center. In addition, in order to drain rain that falls on the athletic facility 1, the athletic facility 1 is provided with, for example, drainage ditches 3 along the four sides of the athletic facility 1 and drainage pits 4 at the four corners of the athletic facility 1. The drainage ditches 3 are connected to the drainage pit 4. The drainage ditches 3 and the drainage pit 4 are buried in the ground so that their upper ends do not protrude from the surface of the athletic facility 1. Rain that falls on the artificial turf 2 flows into the drainage ditches 3 and then flows down the drainage ditches 3 into the drainage pit 4. The wastewater (rainwater) that flows into the drainage pit 4 is drained outside the athletic facility.

[0029] As the artificial turf 2 is used or deteriorates, parts of it break off and become synthetic resin fragments. When rain falls on the artificial turf 2 of the sports facility 1, the rain picks up the synthetic resin fragments and flows into the drain 3 as wastewater containing the synthetic resin fragments. The wastewater that flows into the drain 3 flows down the drain 3 into the drain basin 4. The wastewater that flows into the drain basin 4 is then drained outside the sports facility. For this reason, it is necessary to remove the synthetic resin fragments from the wastewater containing the synthetic resin fragments so that they do not flow into the drainage channel. The drain basin equipped with the separation device disclosed in the present application is intended to remove the synthetic resin fragments from the wastewater containing the synthetic resin fragments.

[0030] [1-2. Structure of the drainage basin] Fig. 2 is a schematic diagram showing an example of the outline of the catch basin according to embodiment 1. Fig. 2(a) is a front view of the catch basin 4. Fig. 2(b) is a top view of the catch basin 4. Fig. 2(c) is a cross-sectional view taken along the line A-A in Fig. 2(b). Fig. 3 is a perspective view of an example of the separation device 21 according to the embodiment 1. Fig. 3(a) is a perspective view seen from the side opposite to the side where the elbow 21b is located. Fig. 3(b) is a perspective view seen from the side where the elbow 21b is located.

[0031] In the example shown in FIG. 2, the catch basin 4 has a rectangular parallelepiped shape including one bottom surface 4a and four side walls 4b. The catch basin 4 shown in FIG. 2 is a rectangular parallelepiped, but is not limited thereto, and may be cylindrical or spherical. As shown in FIGS. 2(a) and (c), a drain groove 3 is connected to the upper part of the side wall 4b. The catch basin 4 has a catch basin drain hole 4c for discharging wastewater below the side wall 4b. The catch basin drain hole 4c is connected to a drain pipe 22 for discharging wastewater outside the sports facility. The top of the catch basin 4 is open, and is covered with, for example, a grating (not shown). The catch basin is made of, for example, concrete.

[0032] [1-3. Configuration of the separation device] 2 and 3, the catch basin 4 includes a separator 21 inside. The separator 21 is arranged such that the side with the elbow 21b faces the side of the catch basin 4 into which wastewater flows, and the side opposite the side with the elbow 21b faces the side of the catch basin 4 from which wastewater flows out, in other words, the side with the catch basin drain hole 4c. The catch basin 4 including the separator 21 separates synthetic resin fragments from wastewater containing the synthetic resin fragments.

[0033] The separation device 21 includes a partition wall 21a and an elbow 21b. The partition wall 21a is a partition wall for separating wastewater from the wastewater from which synthetic resin fragments have been separated. The partition wall 21a has a first end 31a configured to contact the bottom surface 4a of the catch basin 4, and a connection hole 32. The elbow 21b has an outlet side opening portion 33 connected to the connection hole 32, and an inlet side opening portion 34 facing the direction of the first end portion 31a. The partition wall 21a and the elbow 21b may be made of any material that has a predetermined strength and is water resistant, such as synthetic resin.

[0034] Partition wall 21a has a first end 31a configured to contact bottom surface 4a of catch basin 4, a second end defined below, and a third end defined below. Second end 31b: An end configured to contact the side wall of the catch basin 4, intersecting with the first end 31a, and facing the third end 31c. Third end 31c: An end configured to contact the side wall of the catch basin 4, intersecting with the first end 31a, and facing the second end 31b. Partition wall 21a has, for example, a rectangular flat plate shape. When catch basin 4 has a cylindrical shape, second end 31b and third end 31c of partition wall 21a contact the side wall of catch basin 4. When catch basin 4 has a rectangular parallelepiped shape, partition wall 21a has a shape following the cross-sectional shape of catch basin 4, so that second end 31b and third end 31c of partition wall 21a similarly contact the side wall of catch basin 4.

[0035] 4 is a cross-sectional view of the separating device 21 according to the embodiment 1. Here, the first distance H1 of the separating device 21, defined below, is greater than the second distance H2, defined below. The reason for this relationship will be explained in the operation of the separating device, which will be described later. First distance H1: distance from the first end 31a to the portion 32a of the periphery of the connection hole 32 that is closest to the first end Second distance H2: Distance from the first end 31a to the inlet opening 34 of the elbow 21b

[0036] The second end 31b and the third end 31c of the partition wall 21a may be bent toward the opposite side to the elbow 21b. The second end 31b and the third end 31c are shaped as described above, so that the second end 31b and the third end 31c face in the same direction and can contact the same side wall of the catch basin 4. This allows the separation device 21 to be set so as to cover the catch basin drain hole 4c of the catch basin 4 even if the separation device 21 is laterally shifted relative to the catch basin 4. In addition, in Figures 2 and 3, the surface including the second end 31b of the partition wall 21a of the separation device 21 and the surface including the third end 31c are perpendicular to the surface to which the elbow 21b is connected, but are not limited to this, and may be connected by, for example, a gently curved surface.

[0037] Furthermore, the partition wall 21a may have a fourth end 31d, defined below, bent away from the elbow 21b. Fourth end 31d: An end configured to contact the side wall of the catch basin 4 and facing the first end 31a

[0038] By forming the fourth end 31d in the above-mentioned shape, as shown in Fig. 3, the surface having the fourth end 31d is shaped to cover the upper part of the partition wall 21a. This prevents wastewater containing synthetic resin fragments from flowing out even if a large amount of wastewater flows into the catch basin so that the separation device is submerged. If the fourth end 31d of the partition wall 21a is not bent toward the side opposite to the elbow 21b, that is, if the upper part of the partition wall 21a is open, the fourth end 31d of the partition wall 21a may be extended above the catch basin 4 so that the captured synthetic resin fragments do not flow out beyond the partition wall 21a to the side opposite to the elbow 21b.

[0039] Furthermore, a permeable member may be provided in the portion of the partition wall 21a from the first end 31a to the third end 31c that contacts the catch basin 4. For example, as shown in Fig. 3, a permeable member 35 is provided in the first end 31a, the second end 31b, and the third end 31c. The permeable member is, for example, glass wool. When the fourth end 31d is bent toward the side opposite to the elbow 21b, the fourth end 31d may also be provided with a permeable member.

[0040] This makes it possible to prevent synthetic resin fragments from flowing out from the gap between the side wall 4b and the partition wall 21a of the catchment pit 4 when wastewater flows into the catchment pit 4. In addition, for example, when there is no rain for a long period of time, the wastewater stored in the catchment pit flows out through the water-permeable member 35 and the water level gradually drops, so that the wastewater does not stagnate and the generation of mosquito larvae and biofilms is suppressed.

[0041] 3 and 4, the elbow 21b may include a first filter 21c connected to the inlet opening 34 of the elbow 21b. This prevents fragments of synthetic resin separated from the wastewater from flowing out to the downstream side of the catch basin.

[0042] [1-4. Installation of separation device] Fig. 5 is a perspective view showing an aspect in which the separation device 21 according to the first embodiment is installed in the catch basin 4. Fig. 5(a) is a perspective view seen from the catch basin drain hole 4c side in the cross section BB in Fig. 2(b). Fig. 5(b) is a perspective view seen from the side where the separation device 21 is provided in the cross section BB in Fig. 2(b). Fig. 5 shows an example in which the second end 31b, the third end 31c, and the fourth end 31d of the separation device 21 are bent to the side opposite to the side where the elbow 21b is located.

[0043] The separation device 21 is disposed in the catchment 4 such that the side of the separation device 21 with the elbow 21b faces the side into which wastewater flows in the catchment 4, and the side opposite to the elbow faces the side into which wastewater flows out of the catchment 4. The separation device 21 is further disposed so as to be in contact with the bottom surface 4a and the side wall 4b of the catchment 4. Therefore, the first end 31a of the separation device 21 faces the bottom surface 4a of the catchment 4, and the second end 31b, the third end 31c, and the fourth end 31d face the side wall 4b of the catchment 4. The separation device 21 is attached to the catchment 4, for example, by attaching an L-shaped metal fitting 51b to the upper part of the side wall 4b of the catchment 4 in FIG. 5, and fixing the L-shaped metal fitting 51b with a cut bolt 51a and a nut 51c that connect to the separation device 21. There is no need to provide a fixing member that presses the separation device 21 against the side wall 4b. Even if there is a gap smaller than the size of the synthetic resin fragments at the contact point between the catch basin 4 and the separation device 21, the synthetic resin fragments will fill the gap and seal it. Also, the water pressure of the wastewater stored in the catch basin 4 presses the separation device 21 against the side wall 4b. Therefore, the fixing member for attaching the separation device 4 to the catch basin 4 does not need to be one that attaches firmly to the catch basin 4.

[0044] When attaching the separation device 21, a water-permeable member 35 may be attached to the first end 31a to the fourth end 31d, and the separation device 21 may be installed in the catch basin 4. When wastewater flows into the catch basin 4, fragments of synthetic resin are prevented from flowing out from the gap between the catch basin 4 and the separation device 21. On the other hand, when there is no rain for a long period of time, for example, the wastewater stored in the catch basin flows out of the water-permeable member 35 and the water level gradually drops, the wastewater does not stagnate, and the generation of mosquito larvae and biofilms is suppressed.

[0045] [1-4. Operation of the separation device] Fig. 6 is a schematic diagram showing an example of the state of the catchment basin 4 when wastewater flows in. Fig. 6(a) shows the state of the catchment basin 4 when viewed from the front. Fig. 6(b) shows the state of the A-A cross section shown in Fig. 2(b).

[0046] Rain that falls on the artificial turf 2 of the sports facility 1 becomes wastewater 61 containing synthetic resin fragments, such as broken pieces of artificial turf, and first flows into the drainage ditch 3 provided along the four sides of the sports facility 1. The wastewater 61 that flows into the drainage ditch 3 flows down the drainage ditch 3 into the drainage basin 4 as shown in FIG. 6. The inflowing wastewater 61 is stored on the side of the drainage basin 4 where the elbow 21b is located, and the water level of the stored wastewater 62 gradually rises. As shown in FIG. 4 and FIG. 6, when the rising water level exceeds the part 32a closest to the first end in the peripheral part of the connection hole 32 of the partition wall 21a, the wastewater 62 exceeds the connection hole 32 of the partition wall 21a and flows out to the opposite side to the side where the elbow 21b is located. Therefore, the water level of the wastewater 62 in the drainage basin 4 is maintained at a position above the part 32a closest to the first end 31a in the peripheral part of the connection hole 32. Wastewater 62 that has exceeded the connection hole 32 in the partition wall 21a flows into the drain pipe 22 that is connected to the catch basin drain hole 4c. The drain pipe 22 then guides the wastewater 62 to the outside of the exercise facility.

[0047] On the other hand, the specific gravity of most synthetic resins used in artificial turf, such as polyethylene and polypropylene, is smaller than that of water. Therefore, fragments of synthetic resins, such as polyethylene and polypropylene, will float on water. For this reason, as shown in FIG. 6, on the side into which wastewater 61 flows, separated by the partition wall 21a in the drainage basin 4, the wastewater 61 containing synthetic resin fragments is separated into wastewater 62 from which the synthetic resin fragments are separated below the drainage basin 4, and a lump 63 of synthetic resin fragments above the drainage basin 4. Furthermore, since synthetic resins such as polyethylene and polypropylene are hydrophobic, they tend to float on water, facilitating the separation of the synthetic resin fragments from the wastewater 61.

[0048] The water level of the wastewater 62 from which the synthetic resin fragments have been separated is maintained at a position above the portion 32a closest to the first end 31a in the peripheral portion of the connection hole 32, but since the first distance H1 is greater than the second distance H2 as shown in FIG. 4, the inlet opening portion 34 of the elbow 21b is located below the water level of the wastewater 62 and is submerged in water. Therefore, the lump 63 of synthetic resin fragments floating on the wastewater 62 cannot reach the submerged inlet opening portion 34, and is captured on the side separated by the partition wall 21a, where the elbow 21b is located. On the other hand, the wastewater 62 from which the synthetic resin fragments have been separated flows into the elbow 21b from the submerged inlet opening portion 34. The wastewater 62 then passes through the elbow 21b and flows into the space formed by the partition wall 21a and the side wall 4b, and is guided outside the sports facility by the drainage pipe 22.

[0049] Furthermore, since wastewater 61 containing synthetic resin fragments is poured onto the lump 63 of synthetic resin fragments captured on the side where elbow 21b is located, the captured lump 63 of synthetic resin fragments itself functions as a filter, accelerating the process of separating the synthetic resin fragments from the wastewater 61.

[0050] As described above, since the synthetic resin fragments are floated and separated from the wastewater, they do not become clogged in a short period of time as with a filter, and the synthetic resin fragments can be separated from the wastewater over a long period of time. Furthermore, the separated mass of synthetic resin fragments functions as a filter, accelerating the action of separating the synthetic resin fragments from the wastewater. As a result, the maintenance burden can be reduced.

[0051] The elbow 21b may include a first filter 21c connected to the inlet opening 34 of the elbow 21b, as shown in Figs. 2 to 4. The wastewater 61 that flows into the drain 3 flows down the drain 3 into the drain basin 4, as shown in Fig. 6. The inflowing wastewater 61 is stored on the side of the drain basin 4 where the elbow 21b is located, and the water level of the stored wastewater 62 in the drain basin 4 gradually rises. In the early stage of the storage of the wastewater 61, the upper surface of a lump 63 of synthetic resin fragments floating on the wastewater 62 may be located below the inlet opening 34 of the elbow 21b. If the water level of the wastewater 62 rises in this state, the synthetic resin fragments floating on the wastewater 62 may enter the inlet opening 34 of the elbow 21b, and the synthetic resin fragments may flow out into the drain basin drain hole 4c of the drain basin 4. In addition, if a large amount of wastewater 61 containing synthetic resin fragments flows into the drainage manhole 4, the stored wastewater 61 will be agitated, and the synthetic resin fragments will enter the inlet side opening 34 of the elbow 21b, and there is a risk that the synthetic resin fragments will flow out into the drainage manhole drainage hole 4c of the drainage manhole 4.

[0052] Even in such a case, when the elbow 21b includes the first filter 21c connected to the inlet opening 34 of the elbow 21b, the first filter 21c captures the synthetic resin fragments and suppresses the risk of the synthetic resin fragments entering the inlet opening 34 of the elbow 21b. The first filter is, for example, a metal net. The mesh pitch of the filter is, for example, 0.15 mm to 5.0 mm. Even if the size of the smallest fragment containing 90% of the synthetic resin fragments is 1 mm, the mesh pitch of the filter may be larger than 1 mm, for example, 2 mm. This is because the synthetic resin fragments are separated by floating in the wastewater 62, and are also captured by the lump 63 of synthetic resin fragments themselves. A first filter support member 21d that supports the first filter 21c may be provided at the bottom of the first filter 21c. The first filter support member 21d maintains the first filter 21c in a predetermined shape.

[0053] [1-5. Maintenance of separation equipment] The catch basin 4 equipped with the separator 21 accumulates the separated synthetic resin fragments on the side where the elbow 21b separated by the partition wall 21a is located. When a predetermined amount of separated synthetic resin fragments accumulates, it is necessary to remove the accumulated synthetic resin fragments. The accumulated synthetic resin fragments are removed, for example, with dustpans. In this case, it is not necessary to remove all of the accumulated synthetic resin fragments. This is because the synthetic resin fragments that are not removed float on the wastewater 62 and function as a filter. In addition, since there is no structure that requires careful handling, such as a filter, directly below the lump of synthetic resin fragments 63 floating on the wastewater 62, the lump of synthetic resin fragments 63 can be easily removed. Even if a large amount of synthetic resin fragments accumulates due to heavy rain, it is easy to temporarily restore the function of the catch basin 4 by removing the lump of synthetic resin fragments 63 with dustpans or the like.

[0054] Fig. 7 is a schematic diagram showing an example of a method for cleaning a catch basin. The accumulated synthetic resin fragments lumps 63 may be sucked up by a general commercial vacuum cleaner 71 as shown in Fig. 7. When cleaning every corner of the inside of the catch basin 4, the synthetic resin fragments may be sucked up with the vacuum cleaner, the separation device 21 may be removed from the catch basin 4, and the synthetic resin fragments may then be sucked up with the vacuum cleaner. Since the separation device 21 does not need to be firmly fixed to the catch basin 4, the separation device 21 can be easily removed from the catch basin 4.

[0055] [1-6. Summary] As described above, the separation device according to the present disclosure floats synthetic resin fragments and separates them from the wastewater, so it is not clogged in a short period of time like a filter, and can separate synthetic resin fragments from the wastewater over a long period of time. Furthermore, the separated mass of synthetic resin fragments functions as a filter, accelerating the action of separating synthetic resin fragments from the wastewater. As a result, the maintenance burden can be reduced.

[0056] The above-mentioned separation device can be installed in a catchment area with the elbow facing the side where the wastewater flows in and the opposite side to the elbow facing the side where the wastewater flows out. The catchment area can separate synthetic resin fragments from wastewater that contains synthetic resin fragments while reducing the maintenance burden.

[0057] In sports facilities and the like equipped with a drainage basin including a separation device as described above, a separation method is implemented which includes the steps of flowing wastewater into the drainage basin including the separation device as described above, separating synthetic resin fragments from the wastewater using the drainage basin, and draining the wastewater from which the synthetic resin fragments have been separated from the drain side opening of the drainage basin, thereby making it possible to separate the synthetic resin fragments from the wastewater containing the synthetic resin fragments while reducing the maintenance burden.

[0058] <Embodiment 2> Hereinafter, the second embodiment of the present disclosure will be described in detail with reference to the drawings. The elbow 21b of the separation device 21 in the second embodiment further includes an extension pipe 81. The extension pipe 81 is disposed inside the first filter 21c, and extends from the inlet side opening 34 in a direction approaching the first end 31a to a position spaced a predetermined distance from the first end 31a. Other than including the extension pipe 81, the second embodiment is the same as the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and descriptions of the same components, functions, and operations will be omitted.

[0059] Fig. 8 is a cross-sectional view showing an example of a separation device according to embodiment 2. Fig. 8 is a cross-sectional view taken along the line AA in Fig. 2(b). Sand is sometimes spread on the artificial turf 2 of the sports facility 1. This is to improve the durability of the artificial turf and to prevent the artificial turf from turning over by acting as a weight. The sand spread on the artificial turf is finer than the mesh of the first filter 21c, so it is carried by the flow of wastewater and flows into the first filter 21c. However, since sand has a higher specific gravity than water, it is not discharged and accumulates at the bottom of the first filter 21c, which may reduce the drainage capacity. The intrusion of sand can be prevented by making the mesh of the first filter 21c smaller, but making the mesh of the first filter 21c smaller reduces the drainage capacity.

[0060] Therefore, in the second embodiment, an extension pipe 81 is disposed inside the first filter 21c. The extension pipe 81 extends from the inlet opening 34 toward the first end 31a to a position spaced a predetermined distance from the first end 31a. The shape of the extension pipe 81 extending to a position spaced a predetermined distance from the first end 31a concentrates the wastewater flow at the lower opening of the extension pipe 81, speeding up the flow rate of the wastewater above the sand 82 accumulated at the bottom of the first filter 21c, and rolling up the sand 82. The rolled up sand 82 rides on the flow of the wastewater rising inside the extension pipe and is discharged to the side where the drainage basin drain hole 4c is located. The position spaced a predetermined distance from the first end 31a is selected so that the flow rate is sufficient to roll up the sand 82, but the sand does not get clogged. This allows the sand 82 accumulated at the bottom of the first filter 21c to be discharged.

[0061] <Embodiment 3> Hereinafter, the third disclosed embodiment will be described in detail with reference to the drawings. The elbow 21b of the separation device 21 in the third embodiment includes a branch pipe 91a branching from the elbow 21b and extending to the opposite side to the first end 31a, and a second filter 91c connected to an inlet side opening 91b of the branch pipe 91a. Other than including the branch pipe 91a and the second filter 91c, the third embodiment is the same as the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and descriptions of the same components, functions, and operations will be omitted.

[0062] FIG. 9 is a perspective view of an example of the separating device according to the third embodiment, seen from the side where the elbow is located. In the third embodiment, a filter is further provided to increase the drainage capacity. As shown in FIG. 9, the elbow 21b includes a branch pipe 91a branching from the elbow 21b. The elbow 21b including the branch pipe 91a has, for example, a T-shape as a whole. Note that a pipe having a T-shape may be called a T-shaped pipe. A second filter 91c is connected to the inlet opening 91b of the branch pipe 91a. A second filter support member 91d for supporting the second filter 91c may be provided at the top of the second filter 91c. The second filter support member 91d maintains the second filter 91c in a predetermined shape.

[0063] The mesh pitch of the second filter 91c can be selected independently of the mesh pitch of the first filter 21c. For example, the mesh pitch of the second filter 91c may be made larger than the mesh pitch of the first filter 21c, prioritizing the drainage capacity. When draining from the second filter 91c, the lump 63 of synthetic resin fragments floating and captured in the wastewater functions as a filter, so that small synthetic resin fragments are captured by the lump 63 of synthetic resin fragments. Therefore, the mesh pitch of the second filter 91c can be made larger. This can further improve the drainage capacity. In addition, since the drainage capacity is improved by providing two filters, it is also possible to select a drainage basin 4 with a small bottom area.

[0064] <Embodiment 4> Hereinafter, the fourth embodiment of the present disclosure will be described in detail with reference to the drawings. The partition wall 21a of the separation device 21 in the fourth embodiment may have an overflow end portion 101 configured to open to the side wall of the catch basin on the side opposite to the first end portion 31a. The fourth embodiment is the same as the first embodiment except for including the overflow end portion 101. The same components as those in the first embodiment are denoted by the same reference numerals, and descriptions of the same components, functions, and operations will be omitted.

[0065] Fig. 10 is a perspective view of an example of a separation device according to embodiment 4, seen from the side where an elbow is located. Fig. 10(a) shows a case where there is no inclined plate. Fig. 10(b) shows a case where a first inclined plate is included. Fig. 10(c) shows a case where a second inclined plate is further included. In the fourth embodiment, the partition wall 21a of the separation device 21 has an overflow end portion 101 on the side facing the first end portion 31a relative to the connection hole 32, i.e., above the separation device 21. The overflow end portion 101 of the partition wall 21a may be extended to the position of the bottom surface of the drainage groove 3.

[0066] When heavy rain falls, wastewater 61 containing a large amount of synthetic resin fragments flows into the catch basin 4. The separation device shown in Fig. 2 of the first embodiment has a predetermined drainage capacity. However, when the amount of wastewater 61 that flows into the catch basin 4 exceeds the predetermined drainage capacity, the water level in the catch basin 4 gradually rises, and the wastewater 61 eventually overflows outside the catch basin 4. In other words, in Fig. 1, the wastewater overflows onto the artificial turf 2 of the sports facility 1.

[0067] In the fourth embodiment, the partition wall 21a of the separation device 21 has an overflow end 101 on the upper side. Therefore, even if the water level of the catch basin 4 rises, when the water level exceeds the overflow end 101 of the partition wall 21a, the wastewater 61 flows into the catch basin drain hole 4c side of the catch basin 4, and the water level is maintained at a height above the partition wall 21a. As a result, the wastewater 61 is prevented from overflowing outside the catch basin 4.

[0068] When the water level in the catch basin 4 rises and exceeds the partition wall 21a, causing wastewater 61 to flow into the catch basin drain hole 4c side of the catch basin 4, the wastewater 61 contains synthetic resin fragments, and so there is a risk that the synthetic resin fragments will also flow out into the catch basin drain hole 4c side of the catch basin 4. Therefore, as shown in Fig. 10(b), the partition wall 21a may be provided at the overflow end 101 with a first inclined plate 102 that is inclined toward the first end 31a in a direction away from the partition wall 21a.

[0069] The lump of synthetic resin fragments 63 captured by the separator 21 on the side of the partition wall 21a where the elbow 21b is located intertwines and becomes integrated like a bird's nest. Since the first inclined plate 102 has an eave-like shape, one end of the integrated lump of synthetic resin fragments 63 is captured by the first inclined plate 102, and the first inclined plate 102 prevents the lump of synthetic resin fragments 63 from flowing out.

[0070] Furthermore, the partition wall 21a may be provided with a second inclined plate 103 as shown in Fig. 10(c). The second inclined plate 103 is a plurality of inclined plates that are spaced apart from the first inclined plate 102 in the vertical direction of the partition wall 21a and are parallel to the first inclined plate 102. The first inclined plate 102 catches one end of the integrated lump of synthetic resin fragments 63 to prevent it from flowing out, whereas the second inclined plate 103 holds down the integrated lump of synthetic resin fragments 63 with its surface to prevent it from flowing out. Even if the integrated lump of synthetic resin fragments 63 is easily disentangled, the lump of synthetic resin fragments 63 is held down with its surface, so that it is possible to suppress the outflow of the lump of synthetic resin fragments 63.

[0071] <Embodiment 5> Hereinafter, the fifth embodiment of the present disclosure will be described in detail with reference to the drawings. Fig. 11 is a perspective view of an example of a separation device according to embodiment 5, seen from the side where an elbow is located. Fig. 11(a) shows a case where the top of the third filter 111 is open, and Fig. 11(b) shows a case where the top of the third filter 111 is also configured as a filter. The partition wall 21a of the separation device 21 in the fifth embodiment may further include a third filter 111 extending from the overflow end 101 in a direction away from the first end 31a. The partition wall 21a is the same as that of the fourth embodiment except that it includes the third filter 111. The same components as those in the fourth embodiment are denoted by the same reference numerals, and descriptions of the same components, functions, and operations will be omitted.

[0072] 10(a) of the fourth embodiment, when wastewater 61 containing a large amount of synthetic resin fragments flows in, the water level in the catch basin 4 rises and exceeds the overflow end 101 of the partition wall 21a, causing the wastewater 61 to flow out to the catch basin drain hole 4c side of the catch basin 4. Since the wastewater 61 contains synthetic resin fragments, there is a risk that the synthetic resin fragments will also flow out to the catch basin drain hole 4c side of the catch basin 4.

[0073] 11(a) and (b), the partition wall 21a may further include a third filter 111 extending from the overflow end 101 in a direction away from the first end 31a. The upper part of the third filter 111 may be open or may be configured as a filter.

[0074] Even when wastewater 61 containing a large amount of synthetic resin fragments flows in, causing the water level of the catch basin 4 to rise and exceed the overflow end 101 of the partition wall 21a, the third filter 111 removes synthetic resin fragments from the wastewater 61 flowing out to the catch basin drain hole 4c side of the catch basin 4, and allows wastewater not containing synthetic resin fragments to flow out to the catch basin drain hole 4c side of the catch basin 4. In this way, the third filter 111 suppresses the outflow of the lumps 63 of synthetic resin fragments. As shown in FIG. 11(a), when the top of the third filter 111 is open, even if a large amount of wastewater 61 flows in, the wastewater 61 is allowed to overflow, preventing the wastewater 61 from overflowing outside the catch basin 4. As shown in Figure 11 (b), when the upper part of the third filter 111 is configured as a filter, even if the separation device 21 is submerged, it prevents synthetic resin fragments from flowing out into the drainage hole 4c side of the drainage basin 4.

[0075] <Embodiment 6> Hereinafter, the sixth embodiment of the present disclosure will be described in detail with reference to the drawings. Fig. 12 is a perspective view showing an example of a separation device according to embodiment 6. Fig. 12(a) is a perspective view seen from above on the side where elbow 21a is located, and Fig. 12(b) is a perspective view seen from below on the side where elbow 21b is located.

[0076] The separation device 21 in the sixth embodiment may further include an inner cover, the outer edge of which is in contact with the side wall of the catch basin, the inner cover is configured to be located between the bottom surface and the upper end of the catch basin defined below, the inner cover has a notch along the periphery of the opening, and the inner cover is connected to the partition wall such that the notch and the opening are in contact with each other. Drain: A drain connected to the side wall of the drain box and guiding wastewater containing the synthetic resin fragments to the drain box. Other than further including an inner lid, this embodiment is the same as embodiment 4. The same components as those in embodiment 4 are given the same reference numerals, and descriptions of the same components, functions, and operations will be omitted.

[0077] In the case of the catch basin 4 of the example shown in Fig. 10(a) of the fourth embodiment, when wastewater 61 containing a large amount of synthetic resin fragments flows in, the water level of the catch basin 4 rises. When a larger amount of wastewater 61 flows in, the water level of the catch basin 4 finally exceeds the partition wall 21a, and the wastewater 61 flows out to the catch basin drain hole 4c side of the catch basin 4. Since the wastewater 61 contains synthetic resin fragments, there is a risk that the synthetic resin fragments will also flow out to the catch basin drain hole 4c side of the catch basin 4.

[0078] 12(a) and (b), the separation device 21 may further include an inner lid 121. During rainfall, the drain 3 connected to the side wall 4b of the drain pit 4 guides the wastewater 61 containing the synthetic resin fragments to the drain pit 4. The wastewater 61 guided to the drain pit 4 flows down to the side of the drain pit 4 where the elbow 21b is located, and the synthetic resin fragments are separated from the wastewater 61 containing the synthetic resin fragments by the same operation as that of the separation device described in the first embodiment.

[0079] Even if the amount of rainfall increases and a large amount of wastewater 61 flows into the catch basin 4, causing the water level in the catch basin 4 to rise, the inner lid 121 covers the side of the catch basin 4 where the elbow 21b is located, so that the inner lid 121 holds down the upper surface of the lump of synthetic resin fragments 63 floating in the wastewater 62, preventing the fragments from flowing out from the overflow end 101 of the partition wall 21a. In other words, the synthetic resin fragments that have been captured are prevented from flowing out.

[0080] If the amount of rainfall increases further, the water level of the wastewater 61 in the drain 3 will rise further, but when the rising water level of the wastewater 61 reaches above the position of the inner lid 121, the wastewater 61 above the position of the inner lid 121 will be guided above the inner lid 121 as shown by the arrow in Figure 12(a). The wastewater 61 guided above the inner lid 121 will flow into the overflow end 101 of the partition wall 21a that contacts the cutout portion 121a of the inner lid 121. The wastewater 61 that has flowed into the overflow end 101 will pass through the side of the partition wall 21a where the catch basin drain hole 4c is located, and will be guided to the drain pipe 22.

[0081] The cutout 121a of the inner lid 121 and the overflow end 101 of the partition wall 21a that contacts the cutout 121a may be connected by a hinge (not shown). This allows the inner lid 121 to be lifted up against the partition wall 21a, making it easy to remove the lump 63 of synthetic resin fragments.

[0082] <Embodiment 7> Hereinafter, the seventh embodiment of the present disclosure will be described in detail with reference to the drawings. Fig. 13 is a perspective view showing an example of a separation device according to embodiment 7. Fig. 13(a) is a perspective view seen from above on the side where elbow 21a is located, and Fig. 13(b) is a perspective view seen from below on the side where elbow 21b is located.

[0083] The inner cover in the seventh embodiment may have a water channel on the side where the elbow is located. The water channel has an inlet end configured to be connectable to the end of the drain groove, and an outlet hole that opens toward the elbow. This is the same as the sixth embodiment except that it further includes a water channel. The same symbols are used for the same configurations as the sixth embodiment, and explanations of the same configurations, functions, and operations are omitted.

[0084] As shown in FIG. 12(a) of the sixth embodiment, when a large amount of rain falls, the water level inside the catch basin 4 rises, but the presence of the inner lid 121 prevents the lump of synthetic resin fragments 63 floating in the wastewater 62 from flowing out from the overflow end 101 of the partition wall 21a. However, when the water level inside the catch basin 4 rises and the wastewater 61 above the position of the inner lid 121 is guided above the inner lid 121, the lump of synthetic resin fragments 63 may flow back into the drain 4 and flow out from the overflow end 101 of the partition wall 21a. In addition, when the drain 3 is connected to each of the two opposing side walls 4a of the catch basin 4, a large amount of wastewater 61 may flow into only one of the drain basins 3. In such a case, the wastewater 61 containing synthetic resin fragments flowing in from one drain 4 may overflow into the other drain 4.

[0085] Therefore, as shown in Fig. 13(a) and (b), the separation device 21 may further include a waterway 131. An inflow end 131a of the waterway 131 into which the wastewater 61 flows is configured to contact the periphery of the opening of the drainage ditch 3 on the drainage bin 4 side. Therefore, when the amount of precipitation is small, the wastewater 61 guided to the drainage bin 4 flows entirely into the waterway 131. The waterway 131 also has an outflow hole 131b that opens toward the elbow 21b. Therefore, the wastewater 61 that flows into the waterway 131 flows down from the outflow hole 131b to the side of the drainage bin 4 where the elbow 21b is located inside. The wastewater 61 that flows down to the side of the drainage bin 4 where the elbow 21b is located inside is separated from the wastewater 61 containing the synthetic resin fragments by the same operation as that of the separation device described in the first embodiment.

[0086] Even when a large amount of wastewater 61 flows in and the water level of the wastewater 61 in the drain 4 is above the position of the inner lid 121, the lump of synthetic resin fragments 63 captured inside the drain pit 4 must flow back through the water channel 131 via the outflow hole 131b of the water channel 131 in order to flow back into the drain 4. This makes it possible to prevent the lump of synthetic resin fragments 63 captured inside the drain pit 4 from flowing back into the drain 4. Even when a significant amount of wastewater 61 flows into only one of the drain ditches 3, the wastewater 61 containing the synthetic resin fragments that flowed in from one of the drain ditches 3 flows down through the outflow hole 131b of the water channel 131 into the drain pit 4, and the risk of overflowing into the other drain 3 is reduced.

[0087] [Appendix 1] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims rather than the above-described embodiments, and includes the meaning equivalent to the claims and all modifications within the scope thereof. [Explanation of symbols]

[0088] 1. Sports facilities 2 Artificial grass 3. Drain 4. Drainage basin 4a Bottom 4b side wall 4c Drainage basin drainage hole 21 Separation device 21a Bulkhead 21b Elbow 21c 1st filter 21d First filter support member 22 Drainage piping 31a First end 31b Second end 31c 3rd end 31d 4th end 32 Connection hole 33 Outlet side opening 34 Inlet side opening part 35 Permeable materials 51a Bolt 51b L-shaped bracket 51c Nut 61, 62 Wastewater 63 Lump of synthetic resin fragments 71 Commercial vacuum cleaner 81 Extension piping 82 Sand 91a Branch pipe 91b Inlet side opening part 91c 2nd filter 91d Second filter support member 101 Overflow end 102 1st inclined plate 103 2nd inclined plate 111 3rd Filter 121 Inner lid 121 121a Notch 131 Waterway 131a Inlet end 131b Outflow hole

Claims

1. A separation device that is installed in a drainage basin and separates synthetic resin fragments from wastewater containing the synthetic resin fragments, the separation device comprising a partition wall and an elbow, The partition wall is A first end portion configured to contact a bottom surface of the catch basin; a second end configured to contact a side wall of the catch basin and intersecting the first end; a third end portion configured to contact the side wall of the catch basin, intersecting the first end portion and facing the second end portion; a connection hole; The elbow is The outlet opening portion is connected to the connection hole, an inlet opening portion facing the first end portion; A separation device, wherein a first distance, defined below, is greater than a second distance, defined below. First distance: the distance from the first end to the part of the periphery of the connection hole that is closest to the first end Second distance: Distance from the first end to the inlet opening of the elbow

2. The separation device according to claim 1 , wherein the partition wall has the second end and the third end bent toward an opposite side to the elbow.

3. The partition has a fourth end defined below bent away from the elbow. The separation device of claim 2 . A fourth end portion is configured to contact the side wall of the catch basin and is opposite to the first end portion.

4. The separation device according to claim 2 , wherein a water-permeable member is provided at a portion of the partition wall from the first end to the third end that contacts the catch basin.

5. The elbow is A first filter is connected to an inlet side opening portion of the elbow. The separation device of claim 1 .

6. The elbow is and an extension pipe disposed inside the first filter and extending from the inlet opening portion in a direction approaching the first end portion to a position spaced a predetermined distance from the first end portion. The separation device according to claim 5.

7. The elbow is a branch pipe branching from the elbow and extending to an opposite side to the first end; A second filter connected to the inlet side opening portion of the branch pipe, The separation device of claim 1 .

8. The partition wall is An overflow end portion is provided on a side opposite to the first end portion and configured to open to a side wall of the catch basin. The separation device of claim 1 .

9. The partition wall is The separation device according to claim 8 , wherein the overflow end portion is provided with a first inclined plate that is inclined toward the first end portion in a direction away from the partition wall.

10. The partition wall is The separation device according to claim 9 , further comprising a plurality of second inclined plates spaced apart from the first inclined plate in the vertical direction of the partition wall and parallel to the first inclined plate.

11. The partition further includes a third filter extending from the overflow end in a direction away from the first end. The separation device of claim 8.

12. The separating device further includes a lid; The inner cover is configured such that its outer edge contacts the side wall of the catch basin and is positioned between the bottom surface and the upper end of the catch basin defined below, has a cutout portion along the periphery of the overflow end, and is connected to the partition wall so that the cutout portion and the overflow end contact each other. The separation device of claim 8. Drain: A drain connected to the side wall of the catch basin, which guides wastewater containing the synthetic resin fragments to the catch basin.

13. The inner cover has a water channel on the side where the elbow is located, The water channel has an inlet end configured to be connectable to an end of the drainage groove and an outlet hole opening toward the elbow. The separation device of claim 12.

14. A catch basin equipped with the separation device according to any one of claims 1 to 13, The separation device is arranged such that the side of the elbow faces the side of the catch basin into which the wastewater flows, and the side opposite the side of the elbow faces the side of the catch basin from which the wastewater flows. Drain pit.

15. A method for separating synthetic resin fragments from wastewater containing the synthetic resin fragments, comprising the steps of: A step of allowing the wastewater to flow into the catch basin according to claim 14; Separating synthetic resin fragments from the wastewater by the catch basin; The wastewater from which the synthetic resin fragments have been separated is drained from a drainage side opening of the drain basin. Separation method.

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