Wastewater recycling toilet system

Abstract

Provided is a wastewater recycling toilet system that can reduce the amount of pumping work of a wastewater treatment unit.　A wastewater recycling toilet system S comprises: a toilet 10; a circulation section C that includes a treatment unit 20 that treats wastewater from the toilet 10 and a pump 60 that feeds, as washing water, treated water generated through wastewater treatment by the treatment unit 20 to the toilet 10; a surplus water tank 40 that stores surplus water in the circulation section C; a water level gauge 40a that can detect the water level in the surplus water tank 40; a washing line D that connects the surplus water tank 40 to a sewer system via the treatment unit 20 and washes the inside of the treatment unit 20; and a valve V1, a valve V2 and a valve V3 that can limit the distribution amount of water in the washing line D by opening and closing. The valve V1, the valve V2, and the valve V3 can be opened and closed on the basis of detection by the water level gauge 40a.

Description

Wastewater Reuse Toilet System

[0001] The present invention relates to a wastewater recycling toilet system.

[0002] Conventionally, wastewater reuse toilet systems that purify and reuse toilet wastewater are known. Patent Document 1 (JP-A-2005-102626) illustrates this type of technology. This patent document discloses a water treatment system that includes a first unit having a wastewater source, a second unit having at least one of a septic tank, a solid-liquid separation tank, and an oil separation tank for the purpose of water purification and temporarily treating the received wastewater, and a third unit having a wastewater receiving port, a primary water receiving tank, an intermediate treatment tank, a storage treatment tank, a circulating treatment tank, a concentrated wastewater impurity storage tank, and a sterile wastewater tank.

[0003] Japanese Patent Application Laid-Open No. 2023-053995

[0004] However, there is an upper limit to the amount of wastewater that can be treated with a wastewater recycling toilet system, and if this limit is exceeded, sufficient treatment becomes difficult and pumping work within the wastewater treatment unit becomes necessary. Pumping work requires labor costs and other costs, and is time-consuming. In addition, toilet use is restricted during this work, and the pumping work generates foul odors, so there has been a demand for technology to reduce the amount of pumping work.

[0005] The present invention aims to provide a wastewater reuse toilet system that can reduce the amount of pumping work required by a wastewater treatment unit.

[0006] (1) The wastewater reuse toilet system of the present invention comprises a circulation unit including a toilet, a treatment unit that treats wastewater from the toilet, and a water supply unit that supplies treated water produced by the wastewater treatment in the treatment unit to the toilet as flushing water, a surplus water tank that stores surplus water in the circulation unit, a detection unit that can detect the water level in the surplus water tank, a flushing line that connects the surplus water tank to a sewer via the treatment unit and flushes the inside of the treatment unit, and a valve that can be opened and closed to limit the amount of water flowing in the flushing line, and the valve can be opened and closed based on detection by the detection unit.

[0007] (1) The wastewater reuse toilet system can reduce the amount of pumping work required by the wastewater treatment unit.

[0008] (2) The wastewater reuse toilet system described in (1) further includes a control unit capable of controlling the opening and closing operation of the valve, the detection unit being a sensor, and the control unit controlling the opening and closing operation of the valve based on the detection result by the detection unit.

[0009] (2) The wastewater reuse toilet system has a simpler system configuration, which can reduce the amount of pumping work required by the wastewater treatment unit.

[0010] (3) The wastewater reuse toilet system described in (1) further includes an opening / closing mechanism for opening and closing the valve, and the detection unit has a float floating in the water in the surplus water tank, and the opening / closing mechanism opens and closes the valve in conjunction with the movement of the float.

[0011] (3) The wastewater reuse toilet system uses mechanical control to control the opening and closing of the valve, which more reliably reduces the amount of pumping work required by the wastewater treatment unit.

[0012] (4) The wastewater reuse toilet system described in any one of (1) to (3) further includes a rainwater tank for storing rainwater and a rainwater tank detection unit capable of detecting the water level of the rainwater tank, wherein the flushing line can further connect the rainwater tank to a sewer via the processing unit, and the valve can be opened and closed based on the detection operation of the rainwater tank detection unit.

[0013] (4) The wastewater reuse toilet system can more frequently circulate water through the treatment unit into the sewer system to flush the treatment unit, thereby more reliably reducing the amount of pumping work required for the wastewater treatment unit.

[0014] Fig. 1 is a block diagram showing an example of a wastewater reuse toilet system according to an embodiment of the present invention. Fig. 2 is a block diagram showing the hardware configuration of a control device according to an embodiment of the present invention. Fig. 3 is a block diagram showing the functional configuration of a control device according to an embodiment of the present invention. Fig. 4 is a flowchart for explaining cleaning control inside a treatment unit by a control device according to an embodiment of the present invention.

[0015] <Wastewater Reuse Toilet System> A wastewater reuse toilet system S according to one embodiment of the present invention will be described below with reference to Figures 1 to 3. In Figure 1, arrows between blocks indicate the flow of water. Also, dotted lines between blocks indicate communication-enabled connections.

[0016] The wastewater reuse toilet system S uses and purifies water after use, circulating and reusing the water within the system. The wastewater reuse toilet system S includes a toilet 10, a treatment unit 20, a wastewater tank 30, an excess water tank 40, a control device 50, a pump 60, a pump 70, a rainwater tank 80, circulation channels C1, C2, C3, excess water channels F1, treatment unit internal cleaning channels F2, F3, and F4, and valves VC, V1, V2, and V3.

[0017] The toilet 10, the treatment section 20, the waste water tank 30, the pump 60 as a water supply section, the circulation flow paths C1, C2, and C3 described below, and the valve VC function as a circulation section C. In other words, the circulation section C has the treatment section 20, the pump 60, and the circulation flow paths C1, C2, and C3 described below.

[0018] The cleaning line D is a flow path that connects the surplus water tank 40 to the sewer via the treatment unit 20, circulates the surplus water stored in the surplus water tank 40 within the treatment unit 20, and washes away dirt and other contaminants accumulated within the treatment unit 20 and discharges them into the sewer for cleaning. That is, the cleaning line D includes a treatment unit internal cleaning flow path F2 and a treatment unit internal cleaning flow path F4.

[0019] The cleaning line D may further connect the rainwater tank 80 to the sewer via the treatment unit 20. That is, the cleaning line D may include a treatment unit internal cleaning flow path F3. In this case, the cleaning line D connects the rainwater tank 80 to the sewer via the treatment unit 20, and allows rainwater stored in the rainwater tank 80 to flow through the treatment unit 20, thereby washing away dirt and other contaminants accumulated in the treatment unit 20 and discharging the washed water into the sewer. The treatment unit internal cleaning flow paths F2, F3, and F4 will be described in detail below.

[0020] The toilet 10 is a known toilet. The toilet 10 may be located in a private room.

[0021] The treatment unit 20 is configured to treat wastewater from the toilet 10. The treatment unit 20 may have, for example, a sedimentation separation chamber, an aeration treatment chamber, a first shell contact aeration chamber, a second shell contact aeration chamber, a sedimentation filtration chamber, and an activated carbon adsorption chamber.

[0022] In the sedimentation separation chamber, solids in the wastewater are separated. In the aeration treatment chamber, the separated water discharged from the sedimentation separation chamber is aerated. In the first and second shell contact aeration chambers, the treated water discharged from the aeration treatment chamber is further aerated. In the sedimentation filtration chamber, the treated water discharged from the second shell contact aeration chamber is sediment filtered. In the activated carbon adsorption chamber, the supernatant treated water discharged from the sedimentation filtration chamber is decolorized.

[0023] The middle water tank 30 is a tank that stores water that has been treated by the treatment unit 20. The treated water stored in the middle water tank 30 is sucked by the pump 60 and sent to the toilet 10 via the circulation flow path C3.

[0024] Furthermore, in the wastewater reuse toilet system S, water increases by the amount of human waste when a person uses the toilet 10, and therefore the amount of water circulating throughout the system increases. Therefore, as the toilet 10 of the wastewater reuse toilet system S is used and wastewater is treated in the treatment unit 20, the amount of water stored in the wastewater tank 30 increases.

[0025] In this embodiment, the end of the excess water flow path F1 to the excess tank is connected to the upper part of the inner surface of the middle water tank 30, and the treated water in the middle water tank 30 begins to flow into the excess water flow path F1 when its water level rises to the height of the communication port, and then flows to the excess water tank 40 via the excess water flow path F1.

[0026] In addition, a water level meter may be provided in the middle water tank 30 and a pump may be provided in the middle of the surplus water flow path F1, and based on the detection results of the water level meter, the pump may be caused to suck in the treated water stored in the middle water tank 30 and circulate it through the surplus water flow path F1 to the surplus water tank 40.

[0027] The surplus water tank 40 is a water tank that stores surplus water in the circulation section C. The surplus water tank 40 has a water level gauge 40a therein as a detector capable of detecting the water level of the surplus water tank 40. Examples of the water level gauge 40a include an electrode-type water level gauge and a float-type water level gauge. The surplus water tank 40 may have a float floating in the water within the surplus water tank 40 as a detector capable of detecting the water level of the surplus water tank 40, and the water level of the surplus water tank 40 may be mechanically detected by the rising and falling of the float. In this case, the surplus water tank 40 may further have an opening and closing mechanism capable of opening and closing valves V1 and V3 in conjunction with the movement of the float.

[0028] The control device 50 is configured to control various operations of the wastewater reuse toilet system S. Details of the control device 50 will be described later.

[0029] The pump 60 is a known pump provided in the circulation flow path C3 for supplying treated water generated by the wastewater treatment in the treatment unit 20 and stored in the wastewater tank 30 to the toilet 10 as flush water.

[0030] The pump 70 is a known pump that is disposed in the treatment unit cleaning flow path F2 and sends the excess water stored in the excess water tank 40 toward the sewer via the treatment unit 20. The pump 70 may also be disposed in the middle of the treatment unit cleaning flow path F2, closer to the treatment unit 20 than the connection point with the treatment unit cleaning flow path F3, and sends the rainwater stored in the rainwater tank 80 toward the sewer via the treatment unit 20.

[0031] The rainwater tank 80 is a water tank that stores rainwater. The rainwater tank 80 has a water level gauge 80a as a rainwater tank detector that can detect the water level of the rainwater tank 80. Examples of the water level gauge 80a include an electrode-type water level gauge and a float-type water level gauge. The rainwater tank 80 may have a float floating in the water inside the rainwater tank 80 as a detector that can detect the water level of the rainwater tank 80, and the water level of the rainwater tank 80 may be mechanically detected by the rising and falling of the float. In this case, the rainwater tank 80 may further have an opening and closing mechanism that can open and close valves V2 and V3 in conjunction with the movement of the float.

[0032] In either case, the above-mentioned cleaning line D is configured such that the valves V2 and V3 can be opened and closed based on the detection operation of the water level meter 80a so as to further connect the rainwater tank 80 and the sewer via the processing unit 20.

[0033] The circulation flow path C1, the circulation flow path C2, and the circulation flow path C3 are flow paths for circulating the circulating water in the circulation section C of the wastewater reuse toilet system S. The circulation flow path C1 connects the toilet 10 and the treatment section 20. Therefore, the wastewater discharged from the toilet 10 flows to the treatment section 20 via the circulation flow path C1.

[0034] The circulation flow path C2 connects the treatment section 20 and the middle water tank 30. Therefore, the water after treatment in the treatment section 20 flows to the middle water tank 30 via the circulation flow path C2. In addition, a valve VC is provided in the circulation flow path C2. Therefore, by opening and closing the valve VC, the flow of the water after treatment circulating from the treatment section 20 to the middle water tank 30 can be restricted.

[0035] The circulation flow path C3 connects the middle tank 30 and the toilet 10. Therefore, the treated water stored in the middle tank 30 can be circulated to the toilet 10 via the circulation flow path C3. A pump 60 is provided in the circulation flow path C3, and the treated water stored in the middle tank 30 is sucked by the pump 60 and circulated to the toilet 10 via the circulation flow path C3. The circulation flow paths C1, C2, and C3 are configured with piping such as known pipes, for example.

[0036] The surplus water flow path F1 is a flow path for circulating surplus water in the middle water tank 30 to the surplus water tank 40. Therefore, the surplus water flow path F1 connects the middle water tank 30 and the surplus water tank 40. Therefore, the surplus water in the middle water tank 30 can be circulated to the surplus water tank 40 via the surplus water flow path F1. The surplus water flow path F1 is a piping such as a known pipe.

[0037] The treatment section internal cleaning flow path F2 is a flow path for circulating the excess water stored in the excess water tank 40 through the treatment section 20 to clean the inside of the treatment section 20.

[0038] The treatment section internal cleaning flow path F2 connects the surplus water tank 40 and the treatment section 20. Therefore, the surplus water stored in the surplus water tank 40 can be circulated to the treatment section 20.

[0039] The treatment unit internal cleaning flow path F3 is a flow path for circulating rainwater stored in the rainwater tank 80 through the treatment unit 20 to clean the inside of the treatment unit 20. The treatment unit internal cleaning flow path F3 connects the rainwater tank 80 to a midpoint of the treatment unit internal cleaning flow path F2 connected to the treatment unit 20. Therefore, the rainwater stored in the rainwater tank 80 can be circulated to the treatment unit 20 via the treatment unit internal cleaning flow path F3 and the treatment unit internal cleaning flow path F2.

[0040] The treatment unit internal cleaning flow path F4 is a flow path for distributing wastewater that has been circulated within the treatment unit 20 and has washed away dirt and other contaminants from the treatment unit 20 to the sewer. The treatment unit internal cleaning flow path F4 connects the treatment unit 20 to the sewer. Therefore, the wastewater that has been circulated within the treatment unit 20 and has washed away dirt and other contaminants from the treatment unit 20 can be distributed to the sewer.

[0041] Valve VC is a known valve that can be opened and closed to limit the amount of water flowing through circulation section C. Valve VC may be an electrically operated valve, or may be a valve that is mechanically opened and closed by an opening and closing mechanism described later. Valves V1, V2, and V3 are known valves that can be opened and closed to limit the amount of water flowing through cleaning line D described later. Valves V1, V2, and V3 may be electrically operated valves, or may be valves that are mechanically opened and closed by an opening and closing mechanism described later.

[0042] <Control Device> Next, details of the control device 50 will be described using Fig. 2 and Fig. 3. An example of the hardware configuration of the control device 50 will be described using Fig. 2. As shown in Fig. 2, the control device 50 includes a processor 500, a ROM (Read Only Memory) 501, a RAM (Random Access Memory) 502, a bus 503, an input / output interface 504, an input unit 505, an output unit 506, an auxiliary storage device 507, a communication unit 508, and a power supply 509.

[0043] The processor 500 is a central part of a computer that performs various calculations, processes, etc., such as calculations and controls required for the operation of the control device 50. The processor 500 is, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an SoC (System on a Chip), a DSP (Digital Signal Processor), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field-Programmable Gate Array). Alternatively, the processor 500 may be a combination of two or more of these. The processor 500 may also be a combination of these with a hardware accelerator or the like.

[0044] The processor 500 controls each unit to realize various functions of the control device 50 based on programs such as firmware, system software, and application software stored in the ROM 501 or RAM 502. The processor 500 executes processing based on the programs. Note that part or all of the programs may be incorporated into the circuitry of the processor 500.

[0045] The processor 500, ROM 501, and RAM 502 are connected to one another via a bus 503. An input / output interface 504 is also connected to this bus 503. An input unit 505, an output unit 506, an auxiliary storage device 507, a communication unit 508, and a power supply 509 are connected to the input / output interface 504.

[0046] The input unit 505 and output unit 506 are user interfaces electrically connected to the input / output interface 504 via wires or wirelessly. The input unit 505 is composed of, for example, operation buttons, and inputs various information, such as control commands for the wastewater reuse toilet system S, in response to user instructions. The output unit 506 is composed of, for example, a display for displaying images and a speaker for amplifying audio, and outputs images and audio. The output unit 506 may also display the storage volume of the toilet surplus water tank 40 and the storage volume of the rainwater tank 80 in the wastewater reuse toilet system S. In this case, management by the administrator of the wastewater reuse toilet system S can be made easier.

[0047] The auxiliary storage device 507 is composed of a hard disk drive (HDD), a solid state drive (SSD), etc. The auxiliary storage device 507 stores various information such as programs and setting values ​​related to various processes. The auxiliary storage device 507 stores, for example, various information such as determination criteria information, programs, etc. The determination criteria information is information indicating the storage volume of the surplus water tank 40 when it is determined that the surplus water in the surplus water tank 40 should be circulated into the sewer system via the processing unit 20. The determination criteria information may also be information indicating the storage volume of the rainwater tank 80 when it is determined that the rainwater in the rainwater tank 80 should be circulated into the sewer system via the processing unit 20.

[0048] The communication unit 508 is a device that allows the processor 500 to communicate between the water level meter 40a, the water level meter 80a, the valve VC, the valve V1, the valve V2, the valve V3, the pump 60, and the pump 70 of the wastewater reuse toilet system S via a network not shown.

[0049] The power supply 509 is connected to, for example, an external power supply and supplies power to the control device 50. Note that the configuration of the power supply 509 is not limited to this, and the power supply 509 may have a battery and be configured to be able to supply power to each part of the control device 50.

[0050] Next, the functional configuration of the control device 50 will be described with reference to Fig. 3. The control unit 510, which is a functional configuration of the control device 50 that executes various controls of the control device 50, is realized by the processor 500 that executes arithmetic processing by executing programs stored in the ROM 501, RAM 502, auxiliary storage device 507, etc.

[0051] As shown in Figure 3, the control unit 510 of this embodiment has a water level information acquisition unit (water level information acquisition function) 511, a judgment criterion information acquisition unit (judgment criterion information acquisition function) 512, a judgment unit (judgment function) 513, a valve opening / closing control unit (valve opening / closing control function) 514, and a pump control unit (pump control function) 515.

[0052] The water level information acquisition unit 511 executes a process of acquiring the detection results acquired by the water level gauge 40 a of the surplus water tank 40 and the detection results acquired by the water level gauge 80 a of the rainwater tank 80 .

[0053] The criterion information acquisition unit 512 executes a process of acquiring the criterion information stored in the auxiliary storage device 507. The criterion information is information for determining whether or not to perform cleaning processing. For example, the criterion information is information on the water level of the surplus water tank 40 when cleaning processing is performed. The criterion information may also be information on the water level of the rainwater tank 80 when cleaning processing is performed.

[0054] The determination unit 513 determines whether or not to perform cleaning processing inside the processing unit 20 using the cleaning line D. When the water level in the surplus water tank 40 exceeds the above-mentioned determination criterion information, the determination unit 513 determines to perform cleaning processing inside the processing unit 20 using the cleaning line D using the surplus water stored in the surplus water tank 40. Furthermore, if the determination criterion information includes information on the water level in the rainwater tank 80 when cleaning processing is performed, when the water level in the rainwater tank 80 exceeds the determination criterion information, the determination unit 513 determines to perform cleaning processing inside the processing unit 20 using the cleaning line D using the rainwater stored in the rainwater tank 80.

[0055] The valve opening / closing control unit 514 controls the opening and closing operations of the valves VC, V1, V2, and V3. For example, when circulating water is circulated through the circulation unit C, the valve opening / closing control unit 514 controls the valves V1, V2, and V3 to close while controlling the valves VC to open. Furthermore, when circulating at least one of the surplus water in the surplus water tank 40 and the rainwater in the rainwater tank 80 through the treatment unit internal cleaning flow path F2 and discharging waste and the like in the treatment unit 20 into the sewer system, the valve opening / closing control unit 514 controls the valves V1, V2, and V3 to open while controlling the valve VC to close.

[0056] The pump control unit 515 controls the suction operations of the pumps 60 and 70. For example, when circulating water through the circulation unit C, the pump control unit 515 controls the pump 60 to start the suction operation while controlling the pump 70 to stop the suction operation. Furthermore, when circulating at least one of the surplus water in the surplus water tank 40 and the rainwater in the rainwater tank 80 through the treatment unit internal cleaning flow path F2, and when discharging waste and the like in the treatment unit 20 into the sewer, the pump control unit 515 controls the pump 60 to stop the suction operation while controlling the pump 70 to start the suction operation.

[0057] <Treatment Unit In-Flushing Control> Next, the treatment unit in-flush control executed by the control unit 510 of the wastewater reuse toilet system S according to this embodiment will be described with reference to Fig. 4. In the treatment unit in-flush control according to this embodiment, as shown in Fig. 3, a water level information acquisition unit 511, a judgment criterion information acquisition unit 512, a judgment unit 513, a valve opening / closing control unit 514, and a pump control unit 515 function in the processor 500. The treatment unit in-flush control executed by the control unit 510 starts when the wastewater reuse toilet system S is started.

[0058] First, the water level information acquisition unit 511 executes a process of acquiring the detection result from the water level meter 40a of the surplus water tank 40 (step S10). In step S10, the water level information acquisition unit 511 may execute a process of acquiring the detection result from the water level meter 80a of the rainwater tank 80. Next, the determination criterion information acquisition unit 512 acquires the determination criterion information stored in the auxiliary storage device 507 (step S11).

[0059] Next, the determination unit 513 determines whether the water level in the surplus water tank 40 is equal to or higher than a predetermined water level based on the water level information and the determination criterion information (step S12). Note that in step S12, the determination unit 513 may determine whether the water level in the rainwater tank 80 is equal to or higher than a predetermined water level based on the water level information and the determination criterion information.

[0060] If it is determined that the water level in the surplus water tank 40 is not equal to or greater than the predetermined water level (step S12: NO), the control unit 510 proceeds to step S18. If it is further determined whether the water level in the rainwater tank 80 is equal to or greater than the predetermined water level and the water level in the rainwater tank 80 is not equal to or greater than the predetermined water level, the control unit 510 proceeds to step S18. On the other hand, if it is further determined whether the water level in the rainwater tank 80 is equal to or greater than the predetermined water level and the water level in the rainwater tank 80 is equal to or greater than the predetermined water level, the control unit 510 may proceed to step S13.

[0061] If it is determined that the water level in the surplus water tank 40 is equal to or higher than the predetermined water level (step S12: YES), the valve opening / closing control unit 514 controls the opening and closing of valves VC, V1, V2, and V3 to start cleaning the inside of the treatment unit 20 (step S13). Specifically, the valve opening / closing control unit 514 controls valve VC in the treatment unit 20 to close. If it is determined that the water level in the surplus water tank 40 is equal to or higher than the predetermined water level, the valve opening / closing control unit 514 controls valves V1 and V3 of the treatment unit internal cleaning flow path F2 in the cleaning line D to open. Note that if it is determined that the water level in the rainwater tank 80 is equal to or higher than the predetermined water level, the valve opening / closing control unit 514 controls valves V2 and V3 of the treatment unit internal cleaning flow path F2 in the cleaning line D to open.

[0062] Next, the pump control unit 515 starts controlling the pumps 60 and 70 (step S14) to start cleaning the inside of the treatment unit 20. Specifically, the pump control unit 515 controls the pump 60 to stop suctioning and the pump 70 to start suctioning so that at least one of the surplus water in the surplus water tank 40 and the rainwater in the rainwater tank 80 flows through the treatment unit cleaning flow path F2 (step S14).

[0063] Next, the control unit 510 checks whether a predetermined timing has been reached (step S15). The predetermined timing may be, for example, the timing after a predetermined time has elapsed. Alternatively, when the inside of the treatment unit 20 is cleaned with surplus water from the surplus water tank 40, the predetermined timing may be the timing when the water level indicator 40a of the surplus water tank 40 drops below a predetermined water level. Alternatively, when the inside of the treatment unit 20 is cleaned with rainwater from the rainwater tank 80, the predetermined timing may be the timing when the water level indicator 80a of the rainwater tank 80 drops below a predetermined water level.

[0064] If the predetermined timing has not been reached (step S15: NO), the control unit 510 repeats the process until the predetermined timing is reached. If the predetermined timing has been reached (step S15: YES), the valve opening / closing control unit 514 controls the opening and closing of the valves VC, V1, V2, and V3 to terminate cleaning of the processing unit 20 (step S16). Specifically, the valve opening / closing control unit 514 controls the valves V1, V2, and V3 of the processing unit cleaning flow path F2 in the cleaning line D to close those that are open. The valve opening / closing control unit 514 controls the valve VC in the processing unit 20 to open.

[0065] Next, the pump control unit 515 controls the operation of the pump 60 and the pump 70 to complete cleaning of the inside of the processing unit 20 (step S17). Specifically, the pump control unit 515 controls the pump 60 to start a suction operation while controlling the pump 70 to stop a suction operation in order to circulate circulating water through the circulation unit C. Here, cleaning of the inside of the processing unit 20 is completed.

[0066] Next, the control unit 510 checks whether an operation to stop the wastewater reuse toilet system S has been input to the input unit 505 (step S18). If an operation to stop the wastewater reuse toilet system S has not been input to the input unit 505 (step S18: NO), the control unit 510 proceeds to step S10 and repeats the above-described process until an operation to stop the wastewater reuse toilet system S is input to the input unit 505. If an operation to stop the wastewater reuse toilet system S has been input to the input unit 505 (step S18: YES), the control unit 510 ends the treatment unit interior cleaning control.

[0067] The wastewater reuse toilet system S according to the present embodiment described above provides the following advantages. Public toilets are known that employ wastewater reuse toilet systems that purify and reuse toilet wastewater. Wastewater reuse toilet systems are environmentally friendly because they make effective use of water, and because they can be used independently of infrastructure such as water supply and sewerage, they are disaster-resistant systems that can be used even when infrastructure is damaged.

[0068] However, wastewater recycling toilet systems have an upper limit to the amount of wastewater they can process, and if the limit is exceeded, the toilet may become unusable unless pumping work is carried out. Therefore, it is necessary to set toilet capacity and maintenance plans that take into account toilet users.

[0069] When the wastewater volume exceeds the upper limit of the treatable volume, wastewater recycling toilet systems use a vacuum truck to pump out the pre-treatment section (septic tank section) at a set frequency. This not only requires time and money for the pumping work, but also limits the use of the wastewater recycling toilet system during the pumping work. Furthermore, since the pumping work generates a foul odor, complaints about the odor can arise when there are homes or businesses near the wastewater recycling toilet system. Furthermore, when wastewater recycling toilet systems are installed in rural areas far from the dispatching point of the vacuum truck in urban areas, there is a risk that the start of pumping work will be delayed, resulting in a long wait before the system can be used again.

[0070] The wastewater reuse toilet system includes a toilet, a circulation unit that includes a pre-treatment unit that processes wastewater after flushing and a recycling unit that reuses the greywater treated in the pre-treatment unit as flush water, a surplus tank that stores excess water in the circulation unit, a flush line that connects the surplus tank to the sewer system via the pre-treatment unit, a detection unit that detects the water level in the surplus tank, and a control device that controls the opening and closing of a valve in the drainage line based on the amount of water in the surplus tank detected by the detection unit. This allows the treatment unit to be cleaned using excess water, while minimizing the effort and cost of pumping, restrictions on use associated with the work, and complaints about foul odors.

[0071] [Modification] In the above embodiment, the cleaning line D has the valve V1 corresponding to the surplus water tank 40 and the valve V2 corresponding to the rainwater tank 80, but this is not limited to this. For example, the cleaning line D may have a valve common to the surplus water tank 40 and the rainwater tank 80 instead of the valve V1 and the valve V2.

[0072] Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples and do not limit the technical scope of the present invention. The present invention can take various other embodiments, and various modifications such as omissions and substitutions can be made without departing from the spirit of the present invention. These embodiments and their modifications are included in the scope and spirit of the invention described in this specification, etc., and are included in the invention described in the claims and their equivalents.

[0073] 10 Toilet 20 Processing section 40 Surplus water tank 40a Water level meter (detection section) 60 Pump (water supply section) C Circulation section D Flush line V1 Valve V2 Valve V3 Valve S Wastewater reuse toilet system

Claims

1. A wastewater reuse toilet system comprising: a toilet; a circulation unit including a treatment unit that treats wastewater from the toilet and a water supply unit that supplies treated water produced by wastewater treatment in the treatment unit to the toilet as flushing water; a surplus water tank that stores surplus water in the circulation unit; a detection unit that can detect the water level in the surplus water tank; a flushing line that connects the surplus water tank to a sewer system via the treatment unit and flushes the inside of the treatment unit; and a valve that can be opened and closed to limit the amount of water flowing through the flushing line, wherein the valve can be opened and closed based on detection by the detection unit.

2. The wastewater reuse toilet system of claim 1, further comprising a control unit capable of controlling the opening and closing operation of the valve, wherein the detection unit is a sensor, and the control unit controls the opening and closing operation of the valve based on the detection result by the detection unit.

3. A wastewater reuse toilet system as described in claim 1, further comprising an opening and closing mechanism for opening and closing the valve, wherein the detection unit has a float floating in the water in the surplus water tank, and the opening and closing mechanism opens and closes the valve in conjunction with the movement of the float.

4. A wastewater reuse toilet system as described in claim 1 or 2, further comprising: a rainwater tank for storing rainwater; and a rainwater tank detection unit capable of detecting the water level of the rainwater tank, wherein the flushing line can further connect the rainwater tank to a sewer via the processing unit, and the valve can be opened and closed based on the detection operation of the rainwater tank detection unit.

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