Wastewater treatment equipment

Abstract

To measure the amount per unit time of water being transferred in a transfer channel, while preventing the structure of a wastewater treatment device from becoming complicated.SOLUTION: The wastewater treatment device comprises a plurality of water treatment tanks including a first water treatment tank and a second water treatment tank, a pump sucking water from the second water treatment tank, and a transfer channel connected to the pump to transfer water sucked by the pump to the first water treatment tank. The transfer channel forms a first opening and a second opening disposed closer to the pump relative to the first opening and comprises a valve that opens / closes the second opening. The first opening is disposed on a position allowing water flowing out of the first opening to flow into the first water treatment tank, and the second opening is disposed on a position allowing water flowing out of the second opening to flow into the first water treatment tank.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present specification relates to a wastewater treatment device for treating wastewater. [Background technology]

[0002] Conventionally, wastewater treatment has been performed using microorganisms. A wastewater treatment device (also called a septic tank) that performs such wastewater treatment includes a plurality of water treatment tanks (e.g., a plurality of water treatment tanks including an impurity removal tank, an anaerobic filter bed tank, and a carrier fluidized bed tank). To utilize the plurality of water treatment tanks, a wastewater treatment device is also used that includes a pump that draws water from one water treatment tank and a transfer flow path that transfers the water drawn by the pump to another water treatment tank. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-186980 Summary of the Invention [Problem to be solved by the invention]

[0004] For proper water treatment, it is preferable to adjust the amount of water per unit time transported by the transfer flow path to an appropriate range. When the appropriate range of water amount is small, an operator can measure the actual amount of water per unit time by collecting the water flowing out of the transfer flow path in a container such as a beaker. When the appropriate range of water amount is large, a measuring device for measuring the amount of water per unit time is provided in the wastewater treatment device. When a measuring device is provided, various problems can occur. For example, the measuring device occupies a large space within the wastewater treatment device, which can limit the degree of freedom in designing the wastewater treatment device. Furthermore, designing the metering device to match the appropriate range of water amount is a heavy burden.

[0005] The present specification discloses a technique for measuring the amount of water per unit time transferred through a transfer flow path while suppressing the complexity of the configuration of a wastewater treatment device. [Means for solving the problem]

[0006] The techniques disclosed in this specification can be implemented in the following application examples.

[0007] [Application example 1] A wastewater treatment device a plurality of water treatment tanks including a first water treatment tank and a second water treatment tank; a pump that draws water from the second water treatment tank; a transfer flow path connected to the pump and transferring water sucked by the pump to the first water treatment tank; Equipped with the transfer flow path forms a first opening and a second opening disposed closer to the pump than the first opening, and includes a valve that opens and closes the second opening; the first opening is positioned to allow water flowing out of the first opening into the first water treatment tank; The second opening is positioned to allow the water flowing out from the second opening to flow into the first water treatment tank. Wastewater treatment equipment.

[0008] With this configuration, by opening the valve, the water flowing from the transfer flow path into the first water treatment tank can be dispersed between the first and second openings, thereby reducing the amount of water flowing out from each opening per unit time compared to when water flows out from a single opening. Therefore, an operator can easily measure the amount of water flowing from the transfer flow path into the first water treatment tank per unit time. In this way, the amount of water transported per unit time by the transfer flow path can be measured while minimizing the complexity of the wastewater treatment device configuration.

[0009] [Application example 2] The wastewater treatment device according to Application Example 1, the transfer flow path includes a tubular portion, the pipe portion defines the second opening provided on a side surface of the pipe portion; the valve includes a wall portion attached to an outer circumferential side of the pipe portion, The wall portion is attached to the outer circumferential side of the pipe portion so as to be movable between one or more open positions in which the wall portion does not cover at least a portion of the second opening and one or more closed positions in which the wall portion covers the second opening. Wastewater treatment equipment.

[0010] With this configuration, the second opening can be easily opened and closed by moving the wall portion of the valve between the open position and the closed position.

[0011] [Application example 3] The wastewater treatment device according to Application Example 2, the wall portion of the valve is attached to the outer circumferential side of the pipe portion so as to be rotatable in a circumferential direction relative to the pipe portion, the wall portion includes a partial peripheral wall portion that covers a part of the outer peripheral surface of the pipe portion in the circumferential direction, the one or more closed positions are positions of rotational movement of the wall portion in the circumferential direction, and include a position where the partial circumferential wall portion covers the second opening, The one or more open positions are positions of the circumferential rotational movement of the wall portion, and include a position where the partial circumferential wall portion does not cover at least a portion of the second opening. Wastewater treatment equipment.

[0012] According to this configuration, the second opening can be easily opened and closed by rotating the wall portion of the valve in the circumferential direction relative to the pipe portion.

[0013] [Application example 4] The wastewater treatment device according to Application Example 3, The valve has N protrusions fixed to the wall portion and protruding toward the outer circumferential side, the N protrusions being provided at N different positions in the circumferential direction (N is an integer of 2 or more). Wastewater treatment equipment.

[0014] With this configuration, an operator can easily rotate and move the wall portion of the valve by contacting the protrusion with a tool such as a cleaning brush.

[0015] [Application example 5] The wastewater treatment device according to any one of Application Examples 2 to 4, the wall portion of the valve is attached to the outer circumferential side of the pipe portion so as to be movable relative to the pipe portion in an axial direction, which is an extension direction of the pipe portion, the one or more closed positions include positions of the axial movement of the wall portion where the wall portion covers the second opening; the one or more open positions include positions of the axial movement of the wall portion where the wall portion does not cover at least a portion of the second opening. Wastewater treatment equipment.

[0016] According to this configuration, the second opening can be easily opened and closed by moving the wall portion of the valve in the axial direction relative to the tube portion.

[0017] [Application Example 6] The wastewater treatment device according to Application Example 5, The valve has a rod attached to the wall portion, the rod being operated by an operator to move the wall portion in the axial direction. Wastewater treatment equipment.

[0018] With this configuration, the worker can easily move the wall portion in the axial direction by operating the rod.

[0019] [Application Example 7] The wastewater treatment device according to any one of Application Examples 1 to 6, The first opening is provided at an end of the transfer channel. Wastewater treatment equipment.

[0020] This configuration can prevent the configuration of the transfer flow path from becoming complicated.

[0021] [Application Example 8] The wastewater treatment device according to any one of Application Examples 1 to 7, the first water treatment tank includes a baffle plate that forms a receiving portion that receives water flowing into the first water treatment tank; The first opening is positioned to allow the water flowing out of the first opening to flow into the receiving section of the first water treatment tank, The second opening is arranged at a position where the water flowing out from the second opening flows into a portion of the first water treatment tank other than the receiving portion. Wastewater treatment equipment.

[0022] This configuration can prevent the receiving portion, and therefore the baffle plate, from becoming larger.

[0023] The techniques disclosed in this specification can be realized in various forms, for example, in the form of a wastewater treatment device, a wastewater treatment method, and the like. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram showing a wastewater treatment device as an embodiment; [Figure 2] 1A and 1B are explanatory diagrams showing the configuration of a circulation device 1000. FIG. [Figure 3] 10(A)-(E) are explanatory views of the hole forming pipe part 300. FIG. [Figure 4] 1A-1D are explanatory diagrams of the valve 400. [Figure 5] 1A-1F are explanatory diagrams of the rotational positions of the valve 400. [Figure 6] 10A and 10B are explanatory diagrams of another rotational position RP3 of the valve 400. [Figure 7] 10(A) to 10(E) are explanatory views showing a hole forming pipe portion 300x and a valve 400x of a second embodiment. [Figure 8] 10(A) and 10(B) are explanatory diagrams of the movement positions of the valve 400x. DETAILED DESCRIPTION OF THE INVENTION

[0025] A. First Example: A1. Configuration of wastewater treatment device 100: FIG. 1 is a schematic diagram showing a wastewater treatment device according to one embodiment. The figure shows a wastewater treatment device 100 viewed from the side. The wastewater treatment device 100 of this embodiment purifies wastewater W (also called raw water) from a general household or the like (such a device is also called a "septic tank"). The wastewater treatment device 100 has an outer wall 190 that houses multiple water treatment tanks 110-180. In this embodiment, the outer wall 190 forms a substantially cylindrical body 190b that extends in a horizontal first direction X (such a body 190b is also called a pipe).

[0026] In this embodiment, the internal space of body 190b is provided with, in order from the upstream side (left side in FIG. 1), a pre-carrier flow-through tank 120, a contaminant removal tank 110, an anaerobic filter bed tank first chamber 130, an anaerobic filter bed tank second chamber 140, a carrier flow-through tank 150, a circulating filtration tank 160, a disinfection tank 170, and a discharge pump tank 180. Adjacent tanks are separated by a partition wall. Wastewater W flowing into wastewater treatment device 100 is treated by water treatment tanks 110, 120, 130, 140, 150, 160, 170, and 180, in this order.

[0027] Wastewater W that flows into the wastewater treatment device 100 flows into the impurity removal tank 110. The impurity removal tank 110 is a water treatment tank that settles and separates solids contained in the wastewater W. The impurity removal tank 110 is provided with baffle plates 112 and 114 and a first air lift pump 201. The first baffle plate 112 forms a receiving section 113, which is an area surrounded by the first baffle plate 112. The wastewater W is guided to the receiving section 113 by piping (not shown). The impurity removal tank 110 settles and separates solids in the wastewater W and stores them as deposited sludge and scum. The separated water passes through the area surrounded by the second baffle plate 114 and through an opening 131 in the partition wall to flow into the anaerobic filter bed tank first chamber 130.

[0028] The first air lift pump 201 provided in the impurity removal tank 110 uses air from a blower (not shown) to transfer the intermediate water in the impurity removal tank 110 to the upstream carrier fluidization tank 120 .

[0029] The pre-carrier fluidization tank 120 is a water treatment tank that reduces the volume of sludge through aerobic treatment. An aeration device 122 is provided at the bottom of the pre-carrier fluidization tank 120. A plurality of carriers 123 are housed within the pre-carrier fluidization tank 120. The aeration device 122 agitates the water in the pre-carrier fluidization tank 120 by discharging air from a blower (not shown), supplying oxygen to the water within the pre-carrier fluidization tank 120. Aerobic microorganisms attached to the carriers 123 aerobically treat the water within the pre-carrier fluidization tank 120, thereby decomposing organic matter. The water treated in the pre-carrier fluidization tank 120 flows into the impurity removal tank 110 through the opening 111 in the partition wall 115.

[0030] The anaerobic filter bed tank first chamber 130 and the anaerobic filter bed tank second chamber 140 are water treatment tanks that perform anaerobic treatment using anaerobic microorganisms. The anaerobic filter bed tank first chamber 130 is provided with a baffle plate 132 and an anaerobic filter bed 134. Water flowing into the anaerobic filter bed tank first chamber 130 is guided below the anaerobic filter bed 134 by the baffle plate 132. The water below the anaerobic filter bed 134 rises within the anaerobic filter bed 134 and moves above the anaerobic filter bed 134. The anaerobic microorganisms attached to the anaerobic filter bed 134 anaerobically treat the water in the anaerobic filter bed tank first chamber 130. This decomposes organic matter. Nitrate nitrogen and nitrite nitrogen are also reduced to nitrogen gas. The anaerobic filter bed 134 can also capture solids in the water. Solid matter can then be separated by settling in anaerobic filter bed tank first chamber 130. The water treated in anaerobic filter bed tank first chamber 130 flows into anaerobic filter bed tank second chamber 140 through opening 141 in the partition wall.

[0031] The anaerobic filter bed tank second chamber 140 is provided with an anaerobic filter bed 144 and a second air lift pump 202. Water flowing into the anaerobic filter bed tank second chamber 140 moves from above the anaerobic filter bed 144 down through the anaerobic filter bed 144 to below the anaerobic filter bed 144. Anaerobic microorganisms attached to the anaerobic filter bed 144 anaerobically treat the water in the anaerobic filter bed tank first chamber 130. The anaerobic filter bed 144 can also capture solids in the water. The anaerobic filter bed tank second chamber 140 can then settle and separate the solids. The second air lift pump 202 uses air from a blower (not shown) to transport water below the anaerobic filter bed 144 to the carrier fluidized bed tank 150. The second air lift pump 202 can reduce changes in the amount of water transferred per unit time to the carrier fluidized bed tank 150. A metering device may be provided to further suppress changes in the amount of wastewater W transferred per unit time to the carrier flow tank 150. The water level WL1 of the water treatment tanks 110, 130, 140 changes according to changes in the amount of wastewater W flowing into the wastewater treatment device 100 per unit time. In this embodiment, the water level WL1 can fluctuate between a predetermined low water level LWL and a predetermined high water level HWL.

[0032] The baffle plates 112, 114 of the impurity removal tank 110 and the baffle plate 132 of the anaerobic filter bed tank first chamber 130 extend from a position lower than the water level WL1 to a position higher than the water level WL1. In this embodiment, the baffle plates 112, 114, 132 extend from a position lower than the low water level LWL to a position higher than the high water level HWL.

[0033] The carrier fluidized bed tank 150 is a water treatment tank that performs aerobic treatment using aerobic microorganisms. An aeration device 152 is provided at the bottom of the carrier fluidized bed tank 150. Multiple carriers 153 are housed within the carrier fluidized bed tank 150. The aeration device 152 agitates the water in the carrier fluidized bed tank 150 by discharging air from a blower (not shown), supplying oxygen to the water. The aerobic microorganisms attached to the carriers 153 aerobically treat the water in the carrier fluidized bed tank 150, thereby decomposing organic matter. Furthermore, nitrifying bacteria contained in the aerobic microorganisms oxidize ammonium ions in the water to produce nitrite ions and then nitrate ions (nitrification). The water treated in the carrier fluidized bed tank 150 flows into the circulating filtration tank 160 through an opening 161 in the partition wall.

[0034] The circulating filter tank 160 is a water treatment tank that captures solid matter. The circulating filter tank 160 is provided with a baffle plate 162, a filter carrier 164, a third air lift pump 203, and a circulating air lift pump 900. Water flowing into the circulating filter tank 160 is guided below the filter carrier 164 by the baffle plate 162. The water below the circulating filter tank 160 rises within the filter carrier 164 and moves above it. The filter carrier 164 can capture solid matter in the water. The circulating filter tank 160 can also separate solid matter by settling. The water treated by the circulating filter tank 160 flows into the disinfection tank 170 through an opening 171 in the partition wall.

[0035] A third air lift pump 203 provided in the circulating filtration tank 160 uses air from a blower (not shown) to transfer water above the filter media 164 to the carrier fluidized bed tank 150. This causes water to circulate between the carrier fluidized bed tank 150 and the circulating filtration tank 160. Aerobic treatment in the carrier fluidized bed tank 150 and separation of solids in the circulating filtration tank 160 are then repeated.

[0036] The circulation air lift pump 900 sucks water below the filter carrier 164. A transfer flow path 800 is connected to the circulation air lift pump 900. The transfer flow path 800 transfers the water sucked by the circulation air lift pump 900 to the impurity removal tank 110. As a result, solids deposited on the bottom of the circulation filter tank 160 and water containing nitrate ions (nitrification solution) are transferred to the impurity removal tank 110. This transfer causes water to circulate between the water treatment tanks 110-140 and the water treatment tanks 150-160. Hereinafter, the entire combination of the transfer flow path 800 and the circulation air lift pump 900 will also be referred to as the circulation device 1000.

[0037] The disinfection tank 170 is provided with a disinfectant 174, and the water flowing into the disinfection tank 170 is disinfected using the disinfectant 174. The disinfected water flows into the discharge pump tank 180 through an opening 181 in the partition wall.

[0038] The discharge pump tank 180 is equipped with a discharge pump 182. The discharge pump 182 transfers the water in the discharge pump tank 180 to the outside of the wastewater treatment device 100. In this embodiment, the discharge pump 182 is an electric pump.

[0039] The outer wall 190 has a plurality of manhole openings 700 formed at its upper portion. An operator can inspect the inside of the wastewater treatment device 100 through the manhole openings 700. For example, the operator measures the amount of water transferred by the circulation device 1000 per unit time, and adjusts the amount of water transferred by the circulation device 1000 so that the measured amount of water falls within a predetermined appropriate range. For example, the operator adjusts the amount of water transferred by the circulation device 1000 by adjusting the opening of a valve (not shown) provided in a pipe connecting the circulation air lift pump 900 and a blower (not shown).

[0040] A2. Configuration of Circulation Device 1000: 2(A) and 2(B) are explanatory diagrams showing the configuration of the circulation device 1000. FIG. 2(A) shows a portion of the impurity removal tank 110 and a portion of the circulation filtration tank 160 as viewed from the side. FIG. 2(B) shows a portion of the impurity removal tank 110 and a portion of the circulation filtration tank 160 as viewed facing downward. The upward direction Z in the figure indicates the vertically upward direction. The second direction Y indicates the horizontal direction perpendicular to the first direction X. Hereinafter, the upward direction Z will also be referred to as the +Z direction, and the direction opposite to the upward direction Z (i.e., the downward direction) will also be referred to as the -Z direction.

[0041] The circulating air lift pump 900 includes a pipe extending from an intake port 900i located below the water level WL2 in the circulating filter tank 160 to an exhaust port 900o located above the water level WL2. In this embodiment, the intake port 900i is located below the filter carrier 164.

[0042] The transfer flow path 800 is connected to the outlet 900o of the circulation air lift pump 900. In this embodiment, the transfer flow path 800 is a tubular device extending from the outlet 900o of the circulation air lift pump 900 to a first opening 801 located above the receiving section 113 of the impurity removal tank 110 (in this embodiment, at a position higher than the water level WL1). The axis Ax is the central axis of the transfer flow path 800. The height of the axis Ax gradually decreases from the outlet 900o toward the first opening 801. In this embodiment, the entire transfer flow path 800 is located at a position higher than the water surface.

[0043] 2(B), in this embodiment, the first baffle plate 112 has a U-shape when viewed downward (in the -Z direction). Both ends of the first baffle plate 112 are fixed to the partition wall 115. The area surrounded by the partition wall 115 and the first baffle plate 112 is the receiving portion 113. The first opening 801 is disposed within this receiving portion 113.

[0044] The transfer flow path 800 includes a first pipe section 810 connected to the circulation air lift pump 900, a hole formation pipe section 300 connected to the first pipe section 810, a second pipe section 820 connected to the hole formation pipe section 300, and a valve 400 attached to the hole formation pipe section 300. An end section 820e of the second pipe section 820 (i.e., the end section 820e of the transfer flow path 800) forms a first opening 801. The hole formation pipe section 300 and the valve 400 are disposed in the impurity removal tank 110. In this embodiment, the hole formation pipe section 300 and the valve 400 are disposed above the water surface in the impurity removal tank 110. The circulation air lift pump 900 and the transfer flow path 800 are formed of a resin such as polyvinyl chloride, for example.

[0045] 3(A) to 3(E) are explanatory diagrams of the hole forming pipe 300. Fig. 3(A) shows the hole forming pipe 300 viewed from below in the upward direction Z, Fig. 3(B) shows the hole forming pipe 300 viewed from the side in the second direction Y, Fig. 3(C) shows the hole forming pipe 300 viewed from above in the downward direction (-Z direction), and Fig. 3(D) shows the hole forming pipe 300 viewed parallel to the axis Ax in the first direction X. As shown in Fig. 3(D), the hole forming pipe 300 is a tubular member centered on the axis Ax, and forms a cylindrical flow path 301 centered on the axis Ax.

[0046] As shown in FIGS. 3A-3C, the hole forming pipe 300 includes a first socket 310 connected to a first pipe 810, a second socket 320 connected to a second pipe 820, and a central pipe 330 connecting the first socket 310 and the second socket 320. The axis Ax indicates the central axis of the hole forming pipe 300 (and thus the central pipe 330). A second opening 802 is formed in the side surface of the central pipe 330 (in this embodiment, the side surface on the downward (-Z) direction). FIG. 3E is an E-E cross section of FIG. 3B, which is a cross section of the central pipe 330 perpendicular to the axis Ax. This cross section shows the portion of the central pipe 330 where the second opening 802 is formed. As shown in the figure, the second opening 802 is formed in the side surface on the downward (-Z) direction.

[0047] In the drawing, a first partial range R31 indicates a partial range in which the central pipe portion 330 is provided, out of the entire circumferential range (i.e., a range of 360 degrees) centered on the axis Ax. As shown in the drawing, the first partial range R31 is smaller than 360 degrees. In the remaining range, a second partial range R32, the central pipe portion 330 is not formed, and the central pipe portion 330 forms a second opening 802 corresponding to the second partial range R32. The second partial range R32 indicates the circumferential range of the second opening 802.

[0048] 4(A) to 4(D) are explanatory diagrams of the valve 400. FIG. 4(A) shows the valve 400 viewed from below in the upward direction Z, FIG. 4(B) shows the valve 400 viewed from the side in the second direction Y, and FIG. 4(C) shows a cross section of the valve 400 perpendicular to the axis Ax. As shown in FIG. 4(C), the valve 400 includes a wall portion 410 having an arc-shaped cross section centered on the axis Ax, and four protrusions 421-424 having linear cross sections that protrude from the wall portion 410 toward the outer periphery. The valve 400 has a shape obtained by extending this cross-sectional shape along the axis Ax. The cross-sectional shape of the valve 400 perpendicular to the axis Ax is the same regardless of the position in the direction parallel to the axis Ax.

[0049] 4(C) shows positions P1-P4 of the protrusions 421-424, respectively. The positions P1-P4 are fixed positions of the protrusions 421-424 on the outer peripheral surface of the wall portion 410, and are circumferential positions centered on the axis Ax. The circumferential positions can be indicated using angles centered on the axis Ax with respect to a predetermined reference line SL passing through the axis Ax. For example, the first position P1 may be indicated by a first angle Ag1 with respect to the reference line SL. In this embodiment, the positions P1-P4 are different from one another among the protrusions 421-424.

[0050] In the drawing, a first partial region R41 indicates a partial region in which the wall portion 410 is provided, out of the entire circumferential region centered on the axis Ax. As shown in the drawing, the first partial region R41 is smaller than 360 degrees. In the remaining region, a second partial region R42, the wall portion 410 is not formed, and the wall portion 410 forms an opening 490 corresponding to the second partial region R42. The second partial region R42 indicates the circumferential region of the opening 490.

[0051] The inner diameter D410 of the wall portion 410 (FIG. 4(C)) is approximately the same as or slightly smaller than the outer diameter D330 of the central pipe portion 330 (FIG. 3(A)). The width W490 of the opening 490 is smaller than the outer diameter D330 of the central pipe portion 330. The valve 400 is elastically deformable. In this embodiment, the valve 400 is deformed so that the width of the opening 490 is larger than the outer diameter D330 of the central pipe portion 330. The valve 400 is attached to the outer periphery of the central pipe portion 330 so that the central pipe portion 330 fits within the inner periphery of the wall portion 410. The valve 400 attached to the central pipe portion 330 is supported by the central pipe portion 330 and will not fall off. The valve 400 is rotatable about the axis Ax relative to the central pipe portion 330. 4(A) to 4(C) show a state in which the opening 490 is disposed on the upward Z side.

[0052] 5(A)-5(F) are explanatory diagrams of rotational positions of the valve 400. Each diagram shows the hole formation pipe section 300 and the valve 400 attached to the central pipe section 330 of the hole formation pipe section 300. Specifically, FIG. 5(A) shows the hole formation pipe section 300 and the valve 400 viewed from above in a downward direction (-Z direction), FIG. 5(B) shows a cross section perpendicular to the axis Ax of the hole formation pipe section 300 and the valve 400, and FIG. 5(C) shows a portion of the impurity removal tank 110 viewed from the side. FIGS. 5(A)-5(C) show a first rotational position RP1 in which the opening 490 of the valve 400 is positioned upward in the Z direction. FIGS. 5(D)-5(F) are explanatory diagrams similar to FIGS. 5(A)-5(C), respectively. 5(D) to 5(F) show a second rotational position RP2 in which the opening 490 of the valve 400 is positioned on the downward (-Z direction) side.

[0053] As shown in FIG. 5(B), when the valve 400 is attached to the central pipe portion 330, the first partial area R41 of the wall portion 410 of the valve 400 is wider than the second partial area R32 of the second opening 802 of the central pipe portion 330. Therefore, by rotating the valve 400 so that the opening 490 of the valve 400 is positioned on the upward Z side, the wall portion 410 can cover the entire second opening 802. In other words, the second opening 802 is closed. Therefore, as shown in FIG. 5(C), water transferred by the transfer channel 800 does not flow out from the second opening 802 but flows out from the first opening 801. The water Wo1 flowing out from the first opening 801 flows into the impurity removal tank 110 (specifically, the receiving portion 113).

[0054] In this embodiment, in order to suppress agitation of the deposited sludge and scum in the impurity removal tank 110, it is preferable that the water flowing into the impurity removal tank 110 flow into the receiving section 113. Therefore, during normal operation, the rotational position of the valve 400 is set to a position that closes the second opening 802 (for example, the first rotational position RP1 in FIGS. 5(A) to 5(C)). The first rotational position RP1 is an example of a closed position where the wall portion 410 covers the second opening 802.

[0055] At the first rotation position RP1, as shown in FIGS. 5A and 5B, the portion 330a of the central pipe 330 on the upward Z side is exposed through the opening 490 of the valve 400. Generally, the upward Z-side portions of components within the wastewater treatment device 100 are visible from outside the wastewater treatment device 100 through the manhole opening 700 (FIG. 1). Therefore, in this embodiment, the portion 330a on the upward Z side of the central pipe 330 is provided with a closed information display unit 341 that displays closed information indicating that the state of the valve 400 is in a closed state in which the second opening 802 is closed. In this embodiment, the closed information display unit 341 is a sticker affixed to the portion 330a, and displays the text "Normal Operation" as the closed information. By observing the closed information display unit 341, an operator can easily confirm that the state of the valve 400 is in a closed state.

[0056] As shown in FIG. 5(E), when the valve 400 is attached to the central pipe portion 330, the second partial area R42 of the opening 490 of the valve 400 is equal to or larger than the second partial area R32 of the second opening 802 of the central pipe portion 330. Therefore, by rotating the valve 400 so that the opening 490 of the valve 400 is positioned downward (in the -Z direction), the entire second opening 802 can be exposed through the opening 490 of the valve 400. That is, the second opening 802 is opened. Therefore, as shown in FIG. 5(F), the water transferred through the transfer channel 800 is dispersed and flows out from the first opening 801 and the second opening 802. In this embodiment, the water Wo1 flowing out from the first opening 801 flows into the receiving section 113, and the water Wo2 flowing out from the second opening 802 flows into a portion of the impurity removal tank 110 outside the receiving section 113. The second rotational position RP2 is an example of an open position where the wall portion 410 does not cover at least a part of the second opening 802.

[0057] In this way, when water flows out from two openings 801 and 802, the amount of water flowing out from each opening 801 and 802 per unit time can be more appropriately measured than when water flows out from one opening 801. For example, assume that the appropriate water transfer rate by the circulation device 1000 is 2 L / sec. Also assume that an operator uses a 2 L container (e.g., a beaker) to measure the amount of water. If the container receives the water Wo1 flowing out from the first opening 801 in the state of FIG. 5(C), the water overflows from the container after one second has elapsed, making it difficult to measure the amount of water per unit time (e.g., one second). On the other hand, in the state of FIG. 5(F), the amount of water Wo1 flowing out from the first opening 801 per unit time can be approximately 1 L / sec, and the amount of water Wo2 flowing out from the second opening 802 per unit time can be approximately 1 L / sec. In this case, using a 2 L container allows the amount of water per unit time (e.g., one second) to be more appropriately measured. By adding the amount of water Wo1 and the amount of water Wo2 together, the operator can appropriately calculate the amount of water transferred by the circulation device 1000. Then, the operator can easily adjust the amount of water transferred by the circulation device 1000 to an appropriate amount.

[0058] At the second rotational position RP2, as shown in FIGS. 5(D) and 5(E), the first portion 410a of the wall portion 410 of the valve 400, which is the portion opposite the opening 490, is positioned in the upward direction Z. Therefore, in this embodiment, an open information display unit 451 is provided on the first portion 410a of the wall portion 410. The open information display unit 451 displays open information indicating that the state of the valve 400 is an open state in which the second opening 802 is open. In this embodiment, the open information display unit 451 is a sticker attached to the first portion 410a, and displays the text "Check water level" as the open information. By observing the open information display unit 451, the operator can easily confirm that the state of the valve 400 is open.

[0059] After adjusting the transfer amount by the circulation device 1000, the operator rotates the valve 400 to adjust the rotational position of the valve 400 to a closed position (e.g., the first rotational position RP1 (FIGS. 5(A)-5(C))). This allows the circulation device 1000 to properly transfer the water from the circulation filtration tank 160 to the receiving section 113 of the impurity removal tank 110.

[0060] 6(A) and 6(B) are explanatory diagrams of another rotational position RP3 of the valve 400 for closing the second opening 802. FIGS. 6(A) and 6(B) are explanatory diagrams similar to FIGS. 5(A) and 5(B), respectively. Unlike the first rotational position RP1 of FIGS. 5(A) and 5(B), in the third rotational position RP3, the opening 490 of the valve 400 is positioned in a substantially horizontal direction (here, the second direction Y). In this case, too, the wall portion 410 can cover the entire second opening 802. That is, the second opening 802 is closed. This third rotational position RP3, like the first rotational position RP1 (FIGS. 5(A) and 5(B)), is suitable for normal operation. The third rotational position RP3 is an example of a closed position where the wall portion 410 covers the second opening 802.

[0061] At the third rotation position RP3, as shown in FIGS. 6A and 6B, the second portion 410b of the wall portion 410 between the opening 490 and the first portion 410a is positioned on the upward Z side. Therefore, in this embodiment, a closed information display unit 441 is provided on the second portion 410b of the wall portion 410. The closed information display unit 441 displays closed information indicating that the state of the valve 400 is a closed state in which the second opening 802 is closed. In this embodiment, the closed information display unit 441 is a sticker attached to the second portion 410b, and displays the text "Normal operation" as the closed information. By observing the closed information display unit 441, the operator can easily confirm that the state of the valve 400 is a closed state.

[0062] Although not shown in the drawings, the wall portion 410 can cover the entire second opening 802 even when the opening 490 of the valve 400 is located on the side opposite to the second direction Y. This rotational position is also suitable for normal operation. In this rotational position, the third portion 410c of the wall portion 410, which is opposite the second portion 410b, is located on the upward direction Z side. Therefore, in this embodiment, a closed information display unit 442 is provided on the third portion 410c of the wall portion 410, which displays closed information indicating that the state of the valve 400 is closed. Although not shown in the drawings, in this embodiment, the closed information display unit 442 is a sticker attached to the third portion 410c, and displays the text "Normal operation" as closed information.

[0063] In this embodiment, the outer diameter of the socket portions 310, 320 of the hole forming pipe portion 300 is larger than the inner diameter D410 of the wall portion 410 (FIG. 4(C)). Therefore, displacement of the wall portion 410 in a direction parallel to the axis Ax, such as when the wall portion 410 overlaps with the first socket portion 310 or the second socket portion 320, is suppressed. The wall portion 410 is supported by the central pipe portion 330 while being sandwiched between the two socket portions 310, 320.

[0064] Furthermore, in this embodiment, the size of the central pipe portion 330 and the size of the wall portion 410 are configured so that the wall portion 410 can open and close the second opening 802. Specifically, this is as follows. Length L410 in FIG. 4(A) is the length of the wall portion 410 in a direction parallel to the axis Ax. Length L330 in FIG. 3(A) is the length of the central pipe portion 330 in a direction parallel to the axis Ax. Length L802 is the length of the second opening 802 in a direction parallel to the axis Ax. Length L410 of the wall portion 410 is slightly shorter than length L330 of the central pipe portion 330 and sufficiently longer than length L802 of the second opening 802. Therefore, the wall portion 410 can easily close the entire second opening 802. Furthermore, even if the position of the wall portion 410 in the direction parallel to the axis Ax is misaligned between the two socket portions 310, 320, the wall portion 410 can easily close the entire second opening 802.

[0065] As described above, in this embodiment, the wastewater treatment device 100 (FIG. 1) includes multiple water treatment tanks 110-180, including the circulation filtration tank 160 and the impurity removal tank 110. The wastewater treatment device 100 also includes a circulation air lift pump 900 that draws water from the circulation filtration tank 160, and a transfer flow path 800 that is connected to the circulation air lift pump 900 and transfers the water drawn by the circulation air lift pump 900 to the impurity removal tank 110. As described with reference to FIGS. 5(A)-5(F), the transfer flow path 800 has a first opening 801 and a second opening 802 that is positioned closer to the circulation air lift pump 900 than the first opening 801. The transfer flow path 800 also includes a valve 400 that opens and closes the second opening 802. In this embodiment, as shown in Figures 5(C), 5(F), etc., the openings 801 and 802 are arranged above the water surface of the impurity removal tank 110 (i.e., at a position higher than the high water level HWL). In this way, the first opening 801 is arranged at a position where the water Wo1 flowing out from the first opening 801 flows into the impurity removal tank 110. As shown in Figure 5(F), etc., the second opening 802 is arranged at a position where the water Wo2 flowing out from the second opening 802 flows into the impurity removal tank 110.

[0066] According to this configuration, as shown in FIGS. 5(D)-5(F), by opening the valve 400, the water flowing from the transfer flow path 800 into the impurity removal tank 110 can be dispersed to the first opening 801 and the second opening 802. Therefore, the amount of water flowing out from each of the openings 801 and 802 per unit time can be reduced compared to when water flows out from a single opening (for example, the first opening 801 (FIG. 5(C))). Therefore, the operator can easily measure the amount of water flowing from the transfer flow path 800 into the impurity removal tank 110 per unit time. In this way, the operator can measure the amount of water transported per unit time by the transfer flow path 800 while preventing the configuration of the wastewater treatment device 100 from becoming too complicated.

[0067] As shown in FIGS. 2(A), 2(B), 3(A)-3(E), etc., the transfer flow path 800 includes a hole formation pipe 300, which is a tubular portion. The hole formation pipe 300 (FIG. 3(B)) forms a second opening 802 on the side surface of the hole formation pipe 300. As shown in FIGS. 5(A)-5(F), etc., the valve 400 includes a wall 410 attached to the outer periphery of the hole formation pipe 300. The wall 410 is attached to the outer periphery of the hole formation pipe 300 so as to be movable between one or more open positions (e.g., second rotational position RP2) in which the wall 410 does not cover at least a portion of the second opening 802, and one or more closed positions (e.g., rotational positions RP1, RP3) in which the wall 410 covers the second opening 802. Therefore, an operator can easily open and close the second opening 802 by moving the wall 410 of the valve 400 between the open position and the closed position.

[0068] As shown in FIGS. 5(A) to 5(F), the wall portion 410 of the valve 400 is attached to the outer periphery of the hole forming pipe portion 300 so as to be rotatable in the circumferential direction relative to the hole forming pipe portion 300. The wall portion 410 forms a partial circumferential wall portion that covers a partial circumferential range of the outer circumferential surface of the hole forming pipe portion 300 (for example, a first partial range R41 (FIG. 5(B))). (Hereinafter, the wall portion 410 will also be referred to as the partial circumferential wall portion 410.) The one or more closed positions are positions of the wall portion 410 that rotate in the circumferential direction, and include a first rotational position RP1 (FIGS. 5(A)-5(C)) where the partial circumferential wall portion 410 covers the second opening 802. The one or more open positions are positions of the wall portion 410 that rotate in the circumferential direction, and include a second rotational position RP2 (FIGS. 5(D)-5(F)) where the partial circumferential wall portion 410 does not cover at least a portion of the second opening 802. Therefore, an operator can easily open and close the second opening 802 by rotating the wall portion 410 of the valve 400 in the circumferential direction relative to the hole forming pipe portion 300.

[0069] As shown in FIG. 4(C) and other figures, the valve 400 includes protrusions 421-424 that are fixed to the wall 410 and protrude outward. These protrusions 421-424 are provided at different circumferential positions P1-P4, respectively. Therefore, an operator can easily rotate the wall 410 of the valve 400 by contacting any of the protrusions 421-424 with a tool such as a cleaning brush. For example, an operator can rotate the wall 410 from outside the wastewater treatment device 100 through the manhole opening 700 (FIG. 1).

[0070] 2(A) and other figures, the first opening 801 is provided at the end 820e of the transfer channel 800. This prevents the configuration of the transfer channel 800 from becoming complicated. For example, the first opening 801 can be formed by a simple method of cutting the end 820e of the transfer channel 800. In this embodiment, the first opening 801 is perpendicular to the axis Ax. Alternatively, the first opening 801 may be inclined obliquely with respect to the axis Ax. The transfer channel 800 may also include a reference portion that indicates the reference for the water surface height at the first opening 801. The reference portion may have any configuration that indicates the reference for the water surface, such as a line formed on the inner or outer surface of the end 820e or a portion having a three-dimensional shape.

[0071] As shown in FIGS. 2(A) and 2(B), the impurity removal tank 110 includes a baffle plate 112 that forms a receiving section 113 that receives water flowing into the impurity removal tank 110. In this embodiment, as shown in FIGS. 5(C) and 5(F), the first opening 801 is disposed within the receiving section 113, and the second opening 802 is disposed outside the receiving section 113. In this manner, the first opening 801 is disposed at a position that allows the water flowing out from the first opening 801 to flow into the receiving section 113 of the impurity removal tank 110. The second opening 802 is disposed at a position that allows the water flowing out from the second opening 802 to flow into a portion of the impurity removal tank 110 other than the receiving section 113. This prevents the receiving section 113, and therefore the baffle plate 112, from becoming larger.

[0072] B. Second embodiment of the hole-forming pipe and valve: 7(A) to 7(E) are explanatory diagrams showing a hole forming pipe section 300x and a valve 400x of the second embodiment. The hole forming pipe section 300x and the valve 400x can be used in place of the hole forming pipe section 300 and the valve 400 of the first embodiment.

[0073] FIG. 7(A) shows the hole forming pipe 300x viewed from below in the upward direction Z, FIG. 7(B) shows the hole forming pipe 300x viewed from the side in the second direction Y, and FIG. 7(C) shows the hole forming pipe 300x viewed from above in the downward direction (-Z direction). The only difference from the hole forming pipe 300 in FIGS. 3(A)-3(C) is that the central pipe 330x is longer than the central pipe 330 of the first embodiment. The other configurations of the hole forming pipe 300x are the same as the corresponding configurations of the hole forming pipe 300 of the first embodiment (same elements are denoted by the same reference numerals and will not be described again). The central pipe 330x has a second opening 802 formed on its downward (-Z direction) side. The second opening 802 is formed at a position offset from the center of the central pipe 330x toward the second socket 320. Also, as shown in Figure 7(C), an open information display unit 451 is provided in the portion of the central tube portion 330x on the upward Z side near the second socket portion 320, and a closed information display unit 341 is provided in the portion near the first socket portion 310.

[0074] 7(D) and 7(E) are explanatory diagrams of the valve 400x. Fig. 7(D) shows the valve 400x as viewed from the side facing the second direction Y, and Fig. 7(E) shows a cross section of the valve 400x perpendicular to the axis Ax. In this embodiment, the valve 400x includes a cylindrical wall portion 410x centered on the axis Ax, and a rod 480x fixed to the wall portion 410x.

[0075] The inner diameter D410x of the wall portion 410x (FIG. 7(E)) is approximately the same as or slightly larger than the outer diameter D330x of the central pipe portion 330x (FIG. 7(A)). In this embodiment, the valve 400x is attached to the outer peripheral side of the central pipe portion 330x so that the central pipe portion 330x fits inside the wall portion 410x. For example, the valve 400x is fitted into the central pipe portion 330x with the central pipe portion 330x and the first socket portion 310 separated. Thereafter, the first socket portion 310 is fixed to the central pipe portion 330x. The valve 400x attached to the central pipe portion 330x is supported by the central pipe portion 330x without falling off the central pipe portion 330x. The valve 400x is movable relative to the central pipe portion 330x in a direction parallel to the axis Ax.

[0076] 8(A) and 8(B) are explanatory diagrams of the movement position of the valve 400x. Each figure shows a portion of the impurity removal tank 110 seen from the side. Each figure shows the hole forming pipe section 300x and the valve 400x attached to the central pipe section 330x of the hole forming pipe section 300x. The circulation device 1000x of this embodiment is obtained by replacing the transfer flow path 800 of the circulation device 1000 of the first embodiment (FIG. 2(A)) with a transfer flow path 800x. The transfer flow path 800x is obtained by replacing the hole forming pipe section 300 and the valve 400 of the transfer flow path 800 of the first embodiment with the hole forming pipe section 300x and the valve 400x.

[0077] FIG. 8(A) shows a first position SP1 where the valve 400x overlaps with the second opening 802. In this embodiment, the first position SP1 is a position where the valve 400x contacts the second pipe portion 820. FIG. 8(B) shows a second position SP2 where the valve 400x is separated from the second opening 802. In this embodiment, the second position SP2 is a position where the valve 400x contacts the first pipe portion 810. In this embodiment, the size of the central pipe portion 330x and the size of the wall portion 410x are configured so that the wall portion 410x can open and close the second opening 802. Specifically, the size is as follows. The length L330x in FIG. 7(A) is the length of the central pipe portion 330x in a direction parallel to the axis Ax. The length L410x in FIG. 7(D) is the length of the wall portion 410x in a direction parallel to the axis Ax. The length L410x of the wall portion 410x is sufficiently longer than the length L802 (FIG. 7A) of the second opening 802. The length L330x of the central tube portion 330x is at least twice the length L410x of the wall portion 410x.

[0078] As a result, the wall 410x at the first position SP1 (FIG. 8A) can cover the entire second opening 802. That is, the second opening 802 is closed. Therefore, as shown in FIG. 8A, the water transferred by the transfer channel 800x does not flow out from the second opening 802 but flows out from the first opening 801. The water Wo1 that flows out from the first opening 801 flows into the impurity removal tank 110 (specifically, the receiving section 113). Furthermore, when the valve 400x is located at the first position SP1, the open information display 451 is hidden by the wall 410x of the valve 400x, and the closed information display 341 is exposed and not hidden by the wall 410x. By observing the closed information display 341, an operator can easily confirm that the valve 400x is in the closed state. The first position SP1 is an example of a closed position where the wall portion 410x covers the second opening 802.

[0079] Furthermore, when the wall portion 410x is positioned at the second position SP2 (FIG. 8(B)), the entire second opening 802 is exposed. That is, the second opening 802 is open. Therefore, water transferred by the transfer channel 800x is dispersed and flows out from the first opening 801 and the second opening 802. In this embodiment, the water Wo1 flowing out from the first opening 801 flows into the receiving section 113, and the water Wo2 flowing out from the second opening 802 flows into a portion of the impurity removal tank 110 outside the receiving section 113. Furthermore, when the valve 400x is positioned at the second position SP2, the open information display unit 451 is exposed and not hidden by the wall portion 410x of the valve 400x, and the close information display unit 341 is hidden by the wall portion 410x. By observing the open information display unit 451, an operator can easily confirm that the valve 400x is in the open state. The second position SP2 is an example of an open position where the wall portion 410x does not cover at least a part of the second opening 802.

[0080] In this embodiment, the valve 400x has a rod 480x. As shown in FIGS. 8(A) and 8(B), the rod 480x is disposed so as to extend upward in the Z direction from the wall portion 410x. An operator can reach out through the manhole opening 700 (FIG. 1), grasp the rod 480x, and manipulate the rod 480x to move the valve 400x between the first position SP1 and the second position SP2. Although not shown, the manhole opening 700 may be provided with a fixture that fixes the end of the rod 480x when the valve 400x is located at the first position SP1.

[0081] As described above, in this embodiment, the wall portion 410x of the valve 400x is attached to the outer periphery of the central pipe portion 330x so as to be movable in the axial direction (here, a direction parallel to the axis Ax), which is the extension direction of the central pipe portion 330x, relative to the central pipe portion 330x. The one or more closed positions are positions of the wall portion 410x that move in the axial direction, and include a first position SP1 where the wall portion 410x covers the second opening 802. The one or more open positions are positions of the wall portion 410x that move in the axial direction, and include a second position SP2 where the wall portion 410x does not cover at least a portion of the second opening 802. Therefore, an operator can easily open and close the second opening by moving the wall portion 410x of the valve 400x in the axial direction relative to the central pipe portion 330x.

[0082] The valve 400x also has a rod 480x attached to the wall 410x that an operator can operate to move the wall 410x in the axial direction. Therefore, the operator can easily move the wall 410x in the axial direction by operating the rod 480x.

[0083] C. Variations: (1) Various methods may be used to measure the amount of water transferred per unit time by the circulation device 1000, 1000x. In each of the above embodiments, the second opening 802 is formed on the side surface midway along the transfer flow path 800, 800x. Therefore, when the amount of transferred water is large enough that water flows out of the first opening 801 when the valve 400, 400x is open, the amount of water flowing out of the second opening 802 changes only slightly even when the amount of water transferred by the circulation device 1000, 1000x changes. Therefore, a previously measured reference water volume may be used as the amount of water flowing out of the second opening 802 instead of an actual measurement. The sum of the actual measurement of the amount of water flowing out of the first opening 801 and the reference water volume may be used as an approximation of the amount of transferred water.

[0084] (2) In the embodiment of Figures 7(A) to 7(E), the second opening 802 may be formed at a position offset from the center of the central tube portion 330x toward the first socket portion 310. The first position SP1 (Figure 8(A)) may indicate the open position, and the second position SP2 (Figure 8(B)) may indicate the closed position.

[0085] 5(E), if the second subarea R42 of the opening 490 of the valve 400 is larger than the second subarea R32 of the second opening 802, the entire second opening 802 can be exposed through the opening 490 of the valve 400 at various rotational positions of the valve 400. Each of these multiple rotational positions of the valve 400 is an example of an open position.

[0086] When water is caused to flow out from the second opening 802 (FIGS. 5(F) and 8(B)), the valves 400, 400x may cover a portion of the second opening 802. In this way, various positions that do not cover at least a portion of the second opening 802 can be adopted as the position of the valves 400, 400x to cause water to flow out from the second opening 802. However, in order to suppress variation in the amount of water flowing out from the second opening 802, it is preferable to adopt a position that does not cover the entire second opening 802.

[0087] (4) In the embodiment of Figures 4(A) to 4(C), the valve 400 is not limited to the four protrusions 421-424, but may have N protrusions (N is an integer of 2 or more) fixed to the wall 410 and protruding toward the outer periphery, and provided at N different positions in the circumferential direction. The N protrusions may include multiple protrusions having different shapes. However, such protrusions may be omitted.

[0088] (5) The valve configuration may be various other configurations instead of the configuration of the valve 400 (FIG. 4(A) etc.) and the valve 400x (FIG. 7(D) etc.). For example, the rod 480x (FIG. 6(D)) may be omitted. Furthermore, the valve 400 (FIGS. 4(A)-4(C)) of the first embodiment may be attached to the central pipe section 330x of the hole forming pipe section 300x (FIGS. 7(A)-7(E)) of the second embodiment. In this case, both the second rotational position RP2 of FIG. 5(F) and the second position SP2 of FIG. 8(B) can be used as open positions. Furthermore, a position where the position of central pipe portion 330x in a direction parallel to axis Ax is the same as first position SP1 in Fig. 8(A) and the rotational position about axis Ax is the same as the closed position of the first embodiment (for example, rotational positions RP1 and RP3 in Figs. 5(A) and 6(A)) can be used as the closed position. Furthermore, instead of a configuration including a wall portion attached to the outer periphery of the pipe portion like valves 400 and 400x, the valve may be any valve that can open and close an opening, such as a ball valve.

[0089] (6) The configuration of the transfer flow channel may be various other configurations instead of the configuration of the transfer flow channel 800, 800x described above. For example, the second opening 802 (FIGS. 3(B) and 7(B)) may be formed on the side surface of the central pipe section 330, 330x on the horizontal direction (e.g., the second direction Y) side, instead of on the side surface on the downward (-Z direction) side. The valve may include a wall section attached to the outer periphery of the pipe section (e.g., the central pipe section 330, 330x) so as to be movable between an open position where the wall section does not cover at least a portion of the second opening provided on the side surface, and a closed position where the wall section covers the second opening, as in the wall sections 410, 410x shown in FIGS. 4(A) and 7(D). The movement of the wall section is not limited to rotational movement around the central axis of the pipe section and translational movement parallel to the central axis of the pipe section, and may be any movement. Furthermore, the configuration for movably attaching the wall section to the pipe section may be any configuration. For example, the pipe portion may include a support portion such as a guide rail that movably supports the wall portion. Here, the transfer flow path may include a limiting portion that contacts the wall portion to limit the axial movable range of the wall portion (here, the axial direction is the extension direction of the pipe portion), as in the socket portions 310 and 320 in Figures 5(A) and 7(A). However, such a limiting portion may be omitted.

[0090] The transfer flow path may also include a closed information display unit, such as the closed information display units 341, 441, and 442 in FIGS. 3(C), 4(B), 4(C), and 7(C). The closed information display unit is preferably provided in a portion of the transfer flow path that is difficult to observe from the manhole opening 700 when the wall of the valve is in the open position, but is easily observable from the manhole opening 700 when the wall of the valve is in the closed position. The portion that is easily observable from the manhole opening 700 may be, for example, a portion of the transfer flow path located on the upward Z side and that is exposed and not hidden by the valve. The portion that is difficult to observe from the manhole opening 700 may be, for example, a portion hidden by the wall of the valve, or a portion of the transfer flow path (e.g., the valve) located on the downward (-Z) side. The transfer flow path may also include an open information display unit, such as the open information display unit 451 in FIGS. 4(A) and 7(C). The open information display unit is preferably provided in a portion of the transfer flow path that is easily observable from the manhole opening 700 when the valve wall is in the open position, but is difficult to observe from the manhole opening 700 when the valve wall is in the closed position. The information displayed by each of the closed information display unit and the open information display unit may be any information (e.g., character strings, symbols, pictograms, etc.) that indicates the state of the valve (closed state or open state). Furthermore, instead of a sticker, the closed information display unit and the open information display unit may have any configuration that displays information, such as a printed matter printed directly on a portion of the transfer flow path (e.g., the hole forming pipe portion 300, 300x (FIGS. 5(A) and 7(C))), or a portion of the transfer flow path that has a three-dimensional shape. Note that one or both of the closed information display unit and the open information display unit may be omitted.

[0091] Alternatively, the end 820e of the transfer flow path 800, 800x may be closed, and the first opening 801 may be provided in the middle of the transfer flow path 800, 800x, similar to the second opening 802. An operating rod may be attached to the valve 400 of the first embodiment (FIGS. 4(A)-4(C)). Also, the total number of combinations of second openings and valves may be two or more.

[0092] (7) The pump that sucks water to be supplied to the transfer flow path may be any pump that can suck water, such as an electric pump, instead of an air lift pump like the circulation air lift pump 900.

[0093] (8) The wastewater treatment device may have any other configuration instead of the configuration shown in FIG. 1 . For example, the multiple water treatment tanks used for wastewater treatment may be configured with any other water treatment tanks instead of the combination of water treatment tanks 110-180 shown in FIG. 1 . For example, the multiple water treatment tanks may include various types of water treatment tanks, such as a flow control tank and a membrane treatment tank having a membrane separation device. Furthermore, the multiple water treatment tanks used for water treatment may be distributed across multiple bodies. In either case, the pump and the transfer flow path may transfer water between two water treatment tanks arbitrarily selected from the multiple water treatment tanks included in the wastewater treatment device. Generally, the wastewater treatment device may include multiple water treatment tanks, including a first water treatment tank and a second water treatment tank, a pump that draws water from the second water treatment tank, and a transfer flow path connected to the pump and that transfers the water drawn by the pump to the first water treatment tank. The transfer flow path may have a first opening and a second opening located closer to the pump than the first opening, and may include a valve that opens and closes the second opening. The first opening may be positioned to allow water flowing out from the first opening to flow into the first water treatment tank, and the second opening may be positioned to allow water flowing out from the second opening to flow into the first water treatment tank. The first water treatment tank may be a water treatment tank that does not include a baffle plate. The transfer flow path may include a curved portion. The wastewater treatment device may include K bodies (K is an integer greater than or equal to 2) including a first body and a second body. The first body may include one or more water treatment tanks including the first water treatment tank, and the second body may include one or more water treatment tanks including the second water treatment tank. The pump may be configured to suck water from the second water treatment tank in the second body, and the transfer flow path may be configured to transfer the water sucked by the pump to the first water treatment tank in the first body.

[0094] The present invention has been described above based on examples and modifications, but the above-described embodiments of the invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit of the invention, and equivalents thereof are also included within the scope of the present invention. [Explanation of symbols]

[0095] 100...wastewater treatment device, 110...impurity removal tank, 111...opening, 112...first baffle plate, 113...receiving section, 114...second baffle plate, 115...partition wall, 120...pre-carrier fluidization tank, 122...air diffuser, 123...carrier, 130...anaerobic filter bed tank first chamber, 131...opening, 132...baffle plate, 134...anaerobic filter bed, 140...anaerobic filter bed tank second chamber, 141...opening, 144...anaerobic filter bed, 150...Carrier flow tank, 152...Aeration device, 153...Carrier, 160...Circulation filtration tank, 161...Opening, 162...Baffle plate, 164...Filter carrier, 170...Disinfection tank, 171...Opening, 174...Disinfectant, 180...Discharge pump tank, 181...Opening, 182...Discharge pump, 190...Outer wall, 190b...Body, 201...First air lift pump, 202...Second air lift pump, 203...Third Air lift pump, 300, 300x...hole forming pipe portion, 301...flow path, 310...first socket portion, 320...second socket portion, 330, 330x...central pipe portion, 330a...portion, 400, 400x...valve, 410, 410x...wall portion (partial peripheral wall portion), 410a...first portion, 410b...second portion, 410c...third portion, 421-424...protrusion, 341...close information display portion, 441...close Information display unit, 442...closed information display unit, 451...open information display unit, 480x...rod, 490...opening, 700...manhole opening, 800, 800x...transfer flow path, 801...first opening, 802...second opening, 810...first pipe section, 820...second pipe section, 820e...end, 900...circulating air lift pump, 900i...suction port, 900o...discharge port, 1000, 1000x...circulation device, W...drainage, Ax...axis

Claims

1. A wastewater treatment device a plurality of water treatment tanks including a first water treatment tank and a second water treatment tank; a pump that draws water from the second water treatment tank; a transfer flow path connected to the pump and transferring water sucked by the pump to the first water treatment tank; Equipped with the transfer flow path forms a first opening and a second opening disposed closer to the pump than the first opening, and includes a valve that opens and closes the second opening; the first opening is positioned to allow water flowing out of the first opening into the first water treatment tank; the second opening is positioned to allow water flowing out of the second opening into the first water treatment tank, the transfer flow path includes a tubular portion, the pipe portion defines the second opening provided on a side surface of the pipe portion; the valve includes a wall portion attached to an outer circumferential side of the pipe portion, the wall portion is attached to an outer circumferential side of the pipe portion so as to be movable between one or more open positions at which the wall portion does not cover at least a portion of the second opening and one or more closed positions at which the wall portion covers the second opening, the wall portion of the valve is attached to the outer circumferential side of the pipe portion so as to be movable relative to the pipe portion in an axial direction, which is an extension direction of the pipe portion, the one or more closed positions include positions of the axial movement of the wall portion where the wall portion covers the second opening; the one or more open positions include positions of the axial movement of the wall portion where the wall portion does not cover at least a portion of the second opening; The valve has a rod attached to the wall portion, the rod being operated by an operator to move the wall portion in the axial direction. Wastewater treatment equipment.

2. The wastewater treatment device according to claim 1, the first water treatment tank includes a baffle plate that forms a receiving portion for receiving water flowing into the first water treatment tank; The first opening is positioned to allow the water flowing out of the first opening to flow into the receiving section of the first water treatment tank, The second opening is arranged at a position where the water flowing out from the second opening flows into a portion of the first water treatment tank other than the receiving portion. Wastewater treatment equipment.

3. A wastewater treatment device a plurality of water treatment tanks including a first water treatment tank and a second water treatment tank; a pump that draws water from the second water treatment tank; a transfer flow path connected to the pump and transferring water sucked by the pump to the first water treatment tank; Equipped with the transfer flow path forms a first opening and a second opening disposed closer to the pump than the first opening, and includes a valve that opens and closes the second opening; the first opening is positioned to allow water flowing out of the first opening into the first water treatment tank; the second opening is positioned to allow water flowing out of the second opening into the first water treatment tank, the first water treatment tank includes a baffle plate that forms a receiving portion for receiving water flowing into the first water treatment tank; The first opening is positioned to allow the water flowing out of the first opening to flow into the receiving section of the first water treatment tank, The second opening is arranged at a position where the water flowing out from the second opening flows into a portion of the first water treatment tank other than the receiving portion. Wastewater treatment equipment.

4. The wastewater treatment device according to claim 3, the transfer flow path includes a tubular portion, the pipe portion defines the second opening provided on a side surface of the pipe portion; the valve includes a wall portion attached to an outer circumferential side of the pipe portion, the wall portion is attached to the outer circumferential side of the pipe portion so as to be movable between one or more open positions at which the wall portion does not cover at least a portion of the second opening and one or more closed positions at which the wall portion covers the second opening. Wastewater treatment equipment.

5. The wastewater treatment device according to claim 4, the wall portion of the valve is attached to the outer circumferential side of the pipe portion so as to be movable relative to the pipe portion in an axial direction, which is an extension direction of the pipe portion, the one or more closed positions include positions of the axial movement of the wall portion where the wall portion covers the second opening; the one or more open positions include positions of the axial movement of the wall portion where the wall portion does not cover at least a portion of the second opening. Wastewater treatment equipment.

6. The wastewater treatment device according to claim 5, The valve has a rod attached to the wall portion, the rod being operated by an operator to move the wall portion in the axial direction. Wastewater treatment equipment.

7. The wastewater treatment device according to any one of claims 1, 2, 4, 5, and 6, the wall portion of the valve is attached to the outer circumferential side of the pipe portion so as to be rotatable in a circumferential direction relative to the pipe portion, the wall portion includes a partial peripheral wall portion that covers a part of the outer peripheral surface of the pipe portion in the circumferential direction, the one or more closed positions are positions of rotational movement of the wall portion in the circumferential direction, and include a position where the partial circumferential wall portion covers the second opening; the one or more open positions are positions of rotational movement of the wall portion in the circumferential direction, and include a position where the partial circumferential wall portion does not cover at least a portion of the second opening. Wastewater treatment equipment.

8. The wastewater treatment device according to claim 7, The valve has N protrusions fixed to the wall portion and protruding toward the outer circumferential side, the N protrusions being provided at N different positions in the circumferential direction (N is an integer of 2 or more). Wastewater treatment equipment.

9. A wastewater treatment device a plurality of water treatment tanks including a first water treatment tank and a second water treatment tank; a pump that draws water from the second water treatment tank; a transfer flow path connected to the pump and transferring water sucked by the pump to the first water treatment tank; Equipped with the transfer flow path forms a first opening and a second opening disposed closer to the pump than the first opening, and includes a valve that opens and closes the second opening; the first opening is positioned to allow water flowing out of the first opening into the first water treatment tank; the second opening is positioned to allow water flowing out of the second opening into the first water treatment tank, the transfer flow path includes a tubular portion, the pipe portion defines the second opening provided on a side surface of the pipe portion; the valve includes a wall portion attached to an outer circumferential side of the pipe portion, the wall portion is attached to an outer circumferential side of the pipe portion so as to be movable between one or more open positions at which the wall portion does not cover at least a portion of the second opening and one or more closed positions at which the wall portion covers the second opening, the wall portion of the valve is attached to the outer circumferential side of the pipe portion so as to be rotatable in a circumferential direction relative to the pipe portion, the wall portion includes a partial peripheral wall portion that covers a part of the outer peripheral surface of the pipe portion in the circumferential direction, the one or more closed positions are positions of rotational movement of the wall portion in the circumferential direction, and include a position where the partial circumferential wall portion covers the second opening, the one or more open positions are positions of rotational movement of the wall portion in the circumferential direction, and include a position where the partial circumferential wall portion does not cover at least a portion of the second opening; The valve has N protrusions fixed to the wall portion and protruding toward the outer circumferential side, the N protrusions being provided at N different positions in the circumferential direction (N is an integer of 2 or more). Wastewater treatment equipment.

10. The wastewater treatment device according to claim 9, the wall portion of the valve is attached to the outer circumferential side of the pipe portion so as to be movable relative to the pipe portion in an axial direction, which is an extension direction of the pipe portion, the one or more closed positions include positions of the axial movement of the wall portion where the wall portion covers the second opening; the one or more open positions include positions of the axial movement of the wall portion where the wall portion does not cover at least a portion of the second opening. Wastewater treatment equipment.

11. The wastewater treatment device according to any one of claims 1 to 10, The first opening is provided at an end of the transfer channel. Wastewater treatment equipment.

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