Circulating wastewater treatment unit and circulating wastewater treatment system

Abstract

To provide a compact circulating wastewater treatment unit.SOLUTION: A circulating wastewater treatment unit comprises: a wastewater conditioning tank for storing wastewater from users; a biological treatment tank for performing biological treatment on wastewater supplied from the wastewater conditioning tank; a treated water storage tank for storing treated water obtained from the biological treatment; means for supplying ozone to the liquid phase in the treated water storage tank; and means for supplying gas in the treated water storage tank to the biological treatment tank via the wastewater conditioning tank.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a circulating wastewater treatment unit and a circulating wastewater treatment system. [Background technology]

[0002] An autonomous recycling toilet has been proposed (see Patent Document 1). The recycling-type wastewater treatment unit of the toilet described in Patent Document 1 is equipped with a biological treatment tank that treats wastewater using microorganisms, and treated water obtained in the biological treatment tank is oxidized and decolorized using ozone gas in an ozone treatment tank, and then stored in a treated water tank. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-132037 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional technology, an ozone treatment tank for performing treatment using ozone gas is required in addition to the treated water tank. Meanwhile, in small-scale water circulation systems, there is a demand for making the circulation-type wastewater treatment unit as compact as possible.

[0005] The present disclosure aims to provide a compact circulation-type wastewater treatment unit. [Means for solving the problem]

[0006] The circulating wastewater treatment unit of this embodiment comprises a wastewater adjustment tank for storing wastewater from consumers, a biological treatment tank for performing biological treatment on wastewater supplied from the wastewater adjustment tank, a treated water storage tank for storing treated water obtained by biological treatment, a means for supplying ozone to the liquid phase of the treated water storage tank, and a means for supplying gas in the treated water storage tank to the biological treatment tank via the wastewater adjustment tank. Effect of the Invention

[0007] According to the present disclosure, the circulation-type wastewater treatment unit can be made compact. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing the overall configuration of an example of a circulating wastewater treatment unit according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a configuration of an exhaust pipe according to the first embodiment. [Diagram 3] 3 is a diagram showing a modified example of the exhaust pipe shown in FIG. 2. [Figure 4] 3 is a diagram showing another modified example of the exhaust pipe shown in FIG. 2. [Diagram 5] FIG. 7 is a diagram showing a configuration of an exhaust pipe according to a second embodiment. [Figure 6] 6 is a diagram showing a modified example of the exhaust pipe shown in FIG. 5. [Figure 7] 7 is a diagram showing another modified example of the exhaust pipe shown in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (First embodiment) Hereinafter, the first embodiment will be described in detail with reference to the drawings. In the drawings for explaining the embodiment, the same components are generally designated by the same reference numerals, and the repeated description will be omitted.

[0010] <1. Overview> The circulating wastewater treatment unit 1 according to this embodiment is a device for regenerating wastewater (hereinafter simply referred to as wastewater) discharged from a consumer in, for example, a water circulation system. The regenerated water can be used for daily life purposes such as toilet flushing, bathing, showering, laundry, washing dishes, etc. The regenerated water may also be used as drinking water. The water circulation system includes, for example, a treatment tank module in which an adjustment tank, a biological treatment tank, and a water storage tank are compactly arranged to treat and purify wastewater (domestic wastewater, sewage, etc.) discharged from a consumer. The water circulation system also includes a filtration unit having, for example, physical filtration such as a reverse osmosis membrane, a nanofiltration membrane, an ultrafiltration membrane, and a microfiltration membrane, as well as biological filtration, and chemical filtration such as activated carbon, zeolite, and ion exchange resin. The filtration unit, for example, filters water taken from a specific water source. The filtration unit, for example, filters water treated in the treatment tank module. The water circulation system also includes, for example, a UV sterilization unit that sterilizes water to be provided. The water circulation system also includes, for example, an ozone generator. The ozone generator generates ozone gas for, for example, deodorizing the treatment tank module, sterilizing the water in the treatment tank module, and decolorizing the water in the treatment tank module. The water circulation system also includes, for example, a sensor unit for detecting various physical properties in the treatment tank module.

[0011] <2. Overall composition> The overall configuration of a circulating wastewater treatment unit 1 according to this embodiment will be described. Fig. 1 is a diagram showing the overall configuration of an example of a circulating wastewater treatment unit 1. Fig. 1 shows an example in which the circulating wastewater treatment unit 1 is used in a circulating toilet 100. The circulating toilet 100 according to this embodiment is used as a toilet in, for example, a residence, a villa, a mountain hut, a temporary house, or a mobile house built in a mountainous area or the like where water supply and sewage systems are not available. The circulating toilet 100 is also used as a temporary toilet installed, for example, at an outdoor event venue, a construction site, or an evacuation shelter during a disaster. By using the circulating toilet 100, it is possible to treat wastewater and reuse it as circulating water, so the toilet can be used even if water supply and sewage systems are not installed. The circulating wastewater treatment unit 1 according to this embodiment can be used in applications other than the circulating toilet 100. The circulating wastewater treatment unit 1 may be used, for example, to regenerate wastewater used in a kitchen, a washroom (laundry), a bathroom, etc. In this case, for example, in the water circulation system, a filtration unit, a UV sterilization unit, etc. may be installed between the final stage water tank and the actual use of water by the consumer. Also, in the water circulation system, toilet wastewater and wastewater used in the kitchen, washroom (laundry), a bathroom, etc. may be treated in different treatment systems. As shown in FIG. 1, the circulating wastewater treatment unit 1 is connected to a toilet bowl 2 by a plurality of drain pipes. The circulating wastewater treatment unit 1 includes a wastewater adjustment tank 10, a biological treatment tank 20, a treated water storage tank 30, an ozone generator 40, and an exhaust pipe 50 (see FIG. 2). The wastewater adjustment tank 10, the biological treatment tank 20, and the treated water storage tank 30 are connected by a plurality of drain pipes so that water can be sent between predetermined tanks. Each of the plurality of drain pipes is provided with a pump, and the operation of each pump is controlled so that the water level in the tank to which the pump is sent is within a predetermined range and constant continuous operation is performed as much as possible. Note that FIG. 1 is merely an example, and the circulating wastewater treatment unit 1 may have another configuration. For example, the wastewater adjustment tank 10, the biological treatment tank 20, and the treated water storage tank 30 may be included in one module that performs a series of processes.

[0012] <3. Drainage adjustment tank 10> The wastewater adjustment tank 10 is disposed downstream of the toilet 2 and temporarily stores wastewater discharged from the toilet 2. For example, a pulverizing pressure pump may be installed in the toilet 2. The pulverizing pressure pump pulverizes wastewater and the like contained in the wastewater and sends the pulverized wastewater together with the wastewater to the wastewater adjustment tank 10. A blower 11 is provided in the wastewater adjustment tank 10. The blower 11 continuously or intermittently sends air into the wastewater adjustment tank 10. The air sent from the blower 11 agitates the wastewater stored in the wastewater adjustment tank 10. A pump 66 is installed between the wastewater adjustment tank 10 and the biological treatment tank 20. The pump 66 sends the wastewater stored in the wastewater adjustment tank 10 to the biological treatment tank 20.

[0013] <4. Biological treatment tank 20> An example of the configuration of the biological treatment tank 20 will be described. The biological treatment tank 20 uses microorganisms to decompose the organic compounds contained in the wastewater discharged from the wastewater adjustment tank 10. The biological treatment tank 20 may also carry out biological denitrification, which uses the action of microorganisms to remove nitrogen compounds. Biological denitrification combines aerobic microorganisms and facultative anaerobic bacteria to decompose nitrogen and carbon compounds in the wastewater. This method is mainly divided into a nitrification process carried out in an aerobic environment and a denitrification process carried out in an anoxic environment.

[0014] The nitrification process is a reaction in which ammonia (NH4) in wastewater is oxidized to nitrite (NO2) and then to nitrate (NO3). The nitrifying bacteria involved in this reaction are aerobic bacteria that require sufficient dissolved oxygen in the tank.

[0015] The denitrification process is a reaction that reduces nitrite and nitrate to nitrogen gas (N2). In other words, the oxygen from nitrite and nitrate molecules is used instead of dissolved oxygen to oxidize and decompose organic matter into carbon dioxide and water, resulting in the conversion of nitrite and nitrate to nitrogen gas. This process involves facultative anaerobic bacteria called denitrifying bacteria, which exert their denitrification activity in an anaerobic environment without dissolved oxygen.

[0016] The biological treatment tank 20 includes an anoxic tank 21 and an aerobic tank 22. The anoxic tank 21 is disposed upstream of the aerobic tank 22. The biological treatment tank 20 is provided with a drainage channel (not shown) that allows the mixed liquid in the tank to flow between the anoxic tank 21 and the aerobic tank 22. Facultative anaerobic bacteria exist in the mixed liquid in the anoxic tank 21. In the anoxic tank 21, the above-mentioned denitrification process is mainly carried out. An agitator 23 is disposed inside the anoxic tank 21. The agitator 23 is realized, for example, by a mixer having an agitating blade. The agitator 23 agitates the mixed liquid by rotating the agitating blade inside the anoxic tank 21, so as to prevent the microorganisms contained in the mixed liquid from settling. Note that the agitation inside the anoxic tank 21 is not limited to that by the agitator 23. Agitation may also be performed by a pump, aeration, or the like.

[0017] Aerobic bacteria exist in the mixed liquid in the aerobic tank 22. A blower 27 is provided in the aerobic tank 22. The blower 27 supplies air to the mixed liquid in the aerobic tank 22. An aerobic environment is maintained in the aerobic tank 22 by blowing air into the mixed liquid from the blower 27. In the aerobic tank 22, the above-mentioned nitrification process is mainly carried out.

[0018] The aerobic tank 22 is provided with a membrane filtration unit 25. For example, at least one of a microfiltration membrane (MF), an ultrafiltration membrane (UF), a nanofiltration membrane (NF), a ceramic filter, and a metal membrane is used for the membrane filtration unit 25. For example, the membrane filtration unit 25 is disposed above an air supply port supplied from a blower 27. The air supplied from the blower 27 is used for cleaning the membrane filtration unit 25. The membrane filtration unit 25 filters the biologically treated water to produce treated water. A pump 67 is installed between the biological treatment tank 20 and the treated water storage tank 30. The pump 67 sends the treated water filtered by the membrane filtration unit 25 to the treated water storage tank 30. The biological treatment tank 20 may have a different configuration.

[0019] <5. Supply section 90> The biological treatment tank 20 is provided with a supply unit 90 that continuously supplies organic matter to the inside of the biological treatment tank 20. The supply unit 90 supplies organic matter to the anoxic tank 21 of the biological treatment tank 20. The organic matter is a compound that is supplied as a substrate for microorganisms in the biological treatment tank 20. When the circulating toilet 100 is not used for a long period of time, the supply of wastewater containing organic matter to the biological treatment tank 20 is halted, and the microorganisms in the biological treatment tank 20 may die due to a lack of substrate. In order to prevent this, it is necessary to supply organic matter to the biological treatment tank 20. That is, by continuously supplying organic matter to the anoxic tank 21, it is possible to continue supplying substrate to the facultative anaerobic bacteria present in the anoxic tank 21. From the viewpoint of handling, the organic matter is preferably a fluid. Note that the fluid is not limited to a liquid, and also includes substances in a gel state. In addition, a low molecular structure is preferable as the fluid, and for example, an organic compound having 3 or less carbon atoms is more preferable. This is because compounds having a low molecular structure having 3 or less carbon atoms are more biodegradable.

[0020] The organic matter may also be a hydrogen donor. A hydrogen donor is a substance that provides hydrogen to other substances in the biological treatment tank 20 to cause reduction, and is itself dehydrogenated and oxidized. For example, in a state where the denitrification reaction by facultative anaerobic bacteria in the anoxic tank 21 is frequently used, an anoxic atmosphere without dissolved oxygen and the presence of a hydrogen donor necessary for reducing oxygen molecules of nitrite and nitrate are essential. By supplying a hydrogen donor to the anoxic tank 21, the reduction reaction of oxygen molecules of nitrite and nitrate is promoted in the anoxic tank 21. An example of an organic matter that is a fluid that also acts as a hydrogen donor in this way is ethanol.

[0021] The supply unit 90 includes, for example, a constant-volume dispensing and dropping device. The constant-volume dispensing and dropping device supplies the organic matter by dropping it into the anoxic tank 21 continuously and intermittently at a plurality of intervals. The amount of organic matter supplied from the supply unit 90 can be set arbitrarily. In this case, the monthly amount of organic matter to be supplied may be set based on the amount of wastewater. The pump of the supply unit 90 is not limited to a constant amount discharging / dropping device. The supply unit 90 may be a pump that can constantly supply the organic matter at a predetermined flow rate. That is, the supply unit 90 may be a discharging / dropping device that can change the amount of dripping to an arbitrary amount, and in this case, the organic matter is continuously dripped into the anoxic tank 21 to supply it. Note that the supply unit 90 is not necessarily required.

[0022] <6. Treated water storage tank 30> The treated water storage tank 30 is a tank that stores treated water obtained by biologically treating wastewater. In other words, the treated water storage tank 30 is a tank that stores treated water to be supplied to the toilet 2. That is, the treated water storage tank 30 stores treated water obtained by treating wastewater in the biological treatment tank 20. A first pipe 41 leading to the toilet 2 is connected to the treated water storage tank 30 .

[0023] The third pump 63 provided in the first piping 41 supplies treated water for flushing the toilet 2 to the toilet 2 through the first piping 41. The third pump 63 is driven, for example, when the toilet 2 is used. The third pump 63 may be driven in response to an instruction from a user, or in response to detection of use of the toilet 2. Alternatively, the third pump 63 may be driven at predetermined intervals when the circulating toilet 100 has not been used for an extended period of time.

[0024] <7. Ozone Generator 40> The ozone generator 40 generates ozone. The ozone generator 40 directly supplies the generated ozone gas to the treated water storage tank 30. The ozone generator 40 supplies the ozone gas into the treated water in the treated water storage tank 30, i.e., into the liquid phase of the treated water storage tank 30. Note that the ozone gas may also be supplied to the gas phase of the treated water storage tank 30. Methods of generating ozone gas by the ozone generator 40 include, for example, a discharge method (silent discharge method), an electrolysis method (water electrolysis cell method), and an ultraviolet method (mercury UV lamp method / mercury-free UV lamp (excimer lamp) method). Of these, the ultraviolet method (mercury-free UV lamp (excimer lamp) method) is preferable. The ultraviolet method (mercury-free UV lamp (excimer lamp) method) does not generate harmful nitrogen oxides from nitrogen present in the atmosphere when generating ozone gas, and can generate ozone gas with few impurities. Therefore, it is particularly suitable as a method to be adopted in an ozone generator mounted on a small water circulation system installed in a home or the like. By generating ozone gas with few impurities, the operating time of the ozone generator 40 can be reduced, power consumption can be reduced, and the life of the ozone generator 40 can be extended. By generating ozone gas with few impurities, it is possible to reduce the size of the water circulation system equipment and reduce the number of deteriorated and damaged parts, which also leads to a reduction in the frequency of maintenance. In this way, the ozone generator 40 using the ultraviolet method (mercury-free UV lamp (excimer lamp) method) is suitable for small-scale distributed water reclamation. In the treated water storage tank 30, the ozone gas decolorizes, sterilizes, and deodorizes the treated water (hereinafter referred to as ozone treatment) by its strong oxidizing power. Of the ozone gas supplied to the treated water, the surplus ozone gas (gas in the tank) that was not used in the ozone treatment of the treated water fills the space formed in the upper part of the treated water storage tank 30, and is then supplied to the wastewater adjustment tank 10 and / or the biological treatment tank 20, making it possible to reuse it.

[0025] In this embodiment, the concentration of ozone gas supplied to the treated water storage tank 30 can be lower than the concentration of ozone gas supplied to a decolorization tank provided in an existing water purification facility, for example. In an existing water purification facility, the time that water is stored in the decolorization tank (ozone treatment tank) is short, so that the ozone gas and the water need to be contacted in a short time. On the other hand, in this embodiment, the treated water is stored in the treated water storage tank 30 for a long time, so that the ozone gas and the treated water are in contact with each other for a long time. Due to this difference in storage time, the concentration of ozone gas supplied to the treated water storage tank 30 may be lower than the concentration of ozone gas supplied to a decolorization tank provided in an existing water purification facility.

[0026] <8. Exhaust Pipe 50> FIG. 2 is a diagram showing the configuration of the exhaust pipe 50. As shown in FIG. The exhaust pipe 50 forms a path for supplying surplus ozone gas, which is a part of the ozone gas supplied to the treated water storage tank 30 and fills the treated water storage tank 30, to another tank. The exhaust pipeline 50 includes a first exhaust pipe 51 connecting the treated water storage tank 30 and the biological treatment tank 20, and a second exhaust pipe 52 connecting the treated water storage tank 30 and the wastewater adjustment tank 10.

[0027] An exhaust port of the first exhaust pipe 51 in the biological treatment tank 20 is provided, for example, at an end of the ceiling of the biological treatment tank 20. An exhaust port of the second exhaust pipe 52 in the wastewater adjustment tank 10 is provided, for example, at an end of the ceiling of the wastewater adjustment tank 10. In the illustrated example, the excess ozone gas is supplied to the gas phase of each of the biological treatment tank 20 and the wastewater adjustment tank 10, i.e., the region occupied by gas. However, this is not limited to such an example, and the excess ozone gas may be supplied to the liquid phase of each of the biological treatment tank 20 and the wastewater adjustment tank 10, i.e., the region occupied by liquid. The excess ozone gas may be supplied to the liquid phase of both tanks. Also, it may be supplied to the liquid phase of one tank and to the gas phase of the other tank. That is, the exhaust port of the first exhaust pipe 51 in the biological treatment tank 20 may be in the liquid phase of the biological treatment tank 20. Also, the exhaust port of the second exhaust pipe 52 in the wastewater adjustment tank 10 may be in the liquid phase of the wastewater adjustment tank 10. In this case, by providing a blower in the first exhaust pipe 51 and the second exhaust pipe 52, the excess ozone gas can be smoothly sent out into the liquid.

[0028] Excess ozone gas is supplied, for example, constantly from the treated water storage tank 30 to the biological treatment tank 20 through the first exhaust pipe 51. The excess ozone gas supplied to the biological treatment tank 20 is used to perform ozone treatment on odorous substances generated in the biological treatment tank 20. This reduces the odor generated from the biological treatment tank 20.

[0029] The biological treatment tank 20 is equipped with a first exhaust unit 81 that exhausts air from inside the biological treatment tank 20. The first exhaust unit 81 exhausts air from inside the biological treatment tank 20 to the outside. The first exhaust unit 81 is installed, for example, in a position farthest from the exhaust port of the first exhaust pipe 51 in the upper part of the biological treatment tank 20.

[0030] A deodorizer and an ozone decomposer are disposed inside the first exhaust unit 81. This decomposes the residual ozone contained in the residual gas discharged from the first exhaust unit 81. In addition, by disposing the deodorizer inside the first exhaust unit 81, the odor of the residual gas is further reduced.

[0031] Excess ozone gas is supplied, for example, constantly from the treated water storage tank 30 to the wastewater adjustment tank 10 through the second exhaust pipe 52. The excess ozone gas supplied to the wastewater adjustment tank 10 performs ozone treatment on odorous substances generated in the wastewater adjustment tank 10. This reduces the odor generated from the wastewater adjustment tank 10.

[0032] The drainage adjustment tank 10 is equipped with a second exhaust unit 82 that exhausts air from the inside. The second exhaust unit 82 exhausts air from inside the drainage adjustment tank 10 to the outside. The second exhaust unit 82 is installed, for example, in a position farthest from the exhaust port of the second exhaust pipe 52 in the upper part of the drainage adjustment tank 10.

[0033] A deodorizer and an ozone decomposer are disposed inside the second exhaust unit 82. This decomposes the residual ozone contained in the residual gas discharged from the second exhaust unit 82. In addition, by disposing the deodorizer inside the second exhaust unit 82, the odor of the residual gas is further reduced.

[0034] <9.Summary> As described above, in the circulating wastewater treatment unit 1 according to this embodiment, the ozone generator 40 supplies the generated ozone gas to the treated water storage tank 30. The treated water is stored for a long time in the treated water storage tank 30 together with the ozone gas. Therefore, the treated water is ozone-treated inside the treated water storage tank 30, and there is no need to provide a separate ozone treatment tank. This allows the entire exhaust unit to be made compact.

[0035] In addition, in existing water purification facilities, it was necessary to perform ozone treatment in a short time in a small-capacity ozone treatment tank with high sealing performance due to concerns about the oxidizing power of ozone. In this case, it was necessary to increase the concentration of ozone gas in order to perform sufficient ozone treatment in a short time in a small-capacity space. In contrast, in the circulating wastewater treatment unit 1 of this embodiment, ozone treatment is performed inside the treated water storage tank 30, which stores the treated water for a long time, so that even if the concentration of ozone gas is low, the ozone gas and the treated water are in contact with each other for a long time, and sufficient ozone treatment can be performed.

[0036] In addition, since the surplus ozone gas generated in the treated water storage tank 30 can be supplied to the biological treatment tank 20 through the first exhaust pipe 51, the odorous substances (gases in the tank) generated in the biological treatment tank 20 can be treated with ozone. This makes it possible to reduce the odor generated from the biological treatment tank 20. In addition, the oxidative decomposition and biological decomposition of organic matter by the excess ozone gas can be promoted, thereby shortening the time of the biological treatment cycle in the biological treatment tank 20 and reducing the load on the membrane filtration. Furthermore, by reducing the odor of the odorous substance, the consumption of the deodorant provided inside the first exhaust unit 81 can be reduced.

[0037] In addition, the activity of the excess ozone gas can be reduced, and the burden of subsequent treatment of the excess ozone gas can be reduced. For example, the reduction in the activity of the excess ozone gas can reduce the consumption of the ozone decomposing agent provided inside the first exhaust unit 81.

[0038] Furthermore, since the excess ozone gas generated in the treated water storage tank 30 can be supplied to the wastewater adjustment tank 10 through the second exhaust pipe 52, it is possible to subject odorous substances generated in the wastewater adjustment tank 10 to ozone treatment. This makes it possible to reduce the odor generated from the wastewater adjustment tank 10, as well as to reduce the activity of the excess ozone gas, thereby reducing the burden of subsequent treatment of the excess ozone gas. In addition, since excess ozone gas is supplied in parallel from the treated water storage tank 30 to the wastewater adjustment tank 10 and the biological treatment tank 20, odors from the wastewater adjustment tank 10 do not move to the biological treatment tank 20. For example, a user may want to check microorganisms living in the biological treatment tank 20. Since the wastewater adjustment tank 10 and the biological treatment tank 20 are not connected, the user will not notice an odor from the wastewater adjustment tank 10 even when the biological treatment tank 20 is opened.

[0039] Furthermore, because the supply unit 90 continuously supplies organic matter to the biological treatment tank 20, biological activity in the biological treatment tank can be maintained even if the tank is not used regularly or has not been used for a long period of time. There is no need to adjust the timing or amount of organic matter added, so organic matter can be added simply and appropriately even in a circulating toilet 100 whose usage frequency is significantly uneven. This simplifies maintenance of the circulating wastewater treatment unit 1 and reduces maintenance costs.

[0040] <10. Variations> Next, as a modification of the first embodiment, a modification of the exhaust pipe 50 will be described with reference to Fig. 3. Fig. 3 is a diagram showing a modification of the exhaust pipe 50 shown in Fig. 2. In this description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0041] In the exhaust pipe 50 according to this modification, the excess ozone gas flows through each tank in order. That is, the excess ozone gas generated in the treated water storage tank 30 is supplied to the biological treatment tank 20 and then to the wastewater adjustment tank 10. The exhaust pipe 50 includes a first exhaust pipe 51 and a third exhaust pipe 53 connecting the biological treatment tank 20 and the wastewater adjustment tank 10. The intake port of the third exhaust pipe 53 in the biological treatment tank 20 is installed, for example, at a position farthest from the exhaust port of the first exhaust pipe 51 in the biological treatment tank 20. This makes it possible to increase the opportunity for the excess ozone gas to come into contact with the odorous substances. The exhaust port of the third exhaust pipe 53 in the wastewater adjustment tank 10 is installed, for example, at an end of the ceiling of the wastewater adjustment tank 10. Note that this is not limited to such an example, and the excess ozone gas generated in the biological treatment tank 20 may be supplied to the liquid phase of the wastewater adjustment tank 10, that is, to an area occupied by liquid. In other words, the exhaust port of the third exhaust pipe 53 in the wastewater adjustment tank 10 may be in the liquid phase of the wastewater adjustment tank 10. By bringing the odorous gas and the ozone gas into contact in the liquid, the generation and outflow of the excess ozone gas can be reduced.

[0042] Excess ozone gas is supplied, for example, constantly from the biological treatment tank 20 to the wastewater adjustment tank 10 through the third exhaust pipe 53. The excess ozone gas supplied to the wastewater adjustment tank 10 is used to perform ozone treatment on odorous substances generated in the wastewater adjustment tank 10. This reduces the odor generated from the wastewater adjustment tank 10.

[0043] That is, through the first exhaust pipe 51 and the third exhaust pipe 53, the excess ozone gas generated in the treated water storage tank 30 flows from the downstream side to the upstream side of the wastewater. In this modification, the biological treatment tank 20 is not provided with a first exhaust unit 81, and only the wastewater adjustment tank 10 is provided with a second exhaust unit 82. In this modification, the second exhaust unit 82 is installed, for example, in a position farthest from the exhaust port of the third exhaust pipe 53, in the upper part of the wastewater adjustment tank 10. This makes it possible to increase the opportunities for contact between surplus ozone gas and odorous substances.

[0044] As described above, according to the circulation-type wastewater treatment unit 1 of this modification, the excess ozone gas generated in the treated water storage tank 30 is sent back to the biological treatment tank 20 and the wastewater adjustment tank 10 through the exhaust pipe 50. Therefore, since it is sufficient to connect the exhaust pipe 50 to the tanks corresponding to the preceding and following processes along the wastewater treatment process, the exhaust pipe 50 can be easily laid. In addition, there is no need to provide a ventilation unit in the biological treatment tank 20 located in the middle with respect to the flow of the excess ozone gas, and a more compact configuration can be achieved. In addition, the amount of excess ozone gas utilized in the biological treatment tank 20 is less than the amount of excess ozone gas utilized in the wastewater adjustment tank 10. By first supplying the excess ozone gas to the biological treatment tank 20, it is possible to maximize the use of the excess ozone gas in the wastewater adjustment tank 10 to which the excess ozone gas is supplied. This makes it possible to efficiently reduce odors.

[0045] Next, as another modified example of the first embodiment, a modified example of the exhaust pipe 50 will be described with reference to Fig. 4. Fig. 4 is a diagram showing another modified example of the exhaust pipe 50 shown in Fig. 2. In this description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0046] In the exhaust pipe 50 according to this modification, the excess ozone gas flows through each tank in order. That is, the excess ozone gas generated in the treated water storage tank 30 is supplied to the wastewater adjustment tank 10 and then to the biological treatment tank 20. The exhaust pipeline 50 includes a second exhaust pipe 52 and a third exhaust pipe 53. The exhaust port of the second exhaust pipe 52 in the wastewater adjustment tank 10 is installed, for example, at a position farthest from the intake port of the third exhaust pipe 53 in the wastewater adjustment tank 10. This makes it possible to increase the opportunity for the excess ozone gas to come into contact with odorous substances. However, this is not limited to the above example, and the excess ozone gas generated in the wastewater adjustment tank 10 may be supplied to the liquid phase of the biological treatment tank 20. In other words, the exhaust port of the third exhaust pipe 53 in the biological treatment tank 20 may be located in the liquid phase of the biological treatment tank 20.

[0047] Excess ozone gas is supplied, for example, constantly from the treated water storage tank 30 to the wastewater adjustment tank 10 through the second exhaust pipe 52. The excess ozone gas supplied to the wastewater adjustment tank 10 performs ozone treatment on odorous substances generated in the wastewater adjustment tank 10. This reduces the odor generated from the wastewater adjustment tank 10.

[0048] Excess ozone gas is supplied, for example, constantly from the wastewater adjustment tank 10 to the biological treatment tank 20 through the third exhaust pipe 53. The excess ozone gas supplied to the biological treatment tank 20 is used to perform ozone treatment on odorous substances generated in the biological treatment tank 20. This reduces the odor generated from the biological treatment tank 20.

[0049] That is, via the second exhaust pipe 52 and the third exhaust pipe 53, excess ozone gas generated in the treated water storage tank 30 flows from the wastewater adjustment tank 10, which has a stronger odor, toward the biological treatment tank 20. In this modification, the second exhaust unit 82 is not provided in the wastewater adjustment tank 10, and the first exhaust unit 81 is provided only in the biological treatment tank 20. In this modification, the first exhaust unit 81 is installed, for example, in a position farthest from the exhaust port of the third exhaust pipe 53 in the upper part of the biological treatment tank 20. This makes it possible to increase the opportunities for contact between the surplus ozone gas and odorous substances.

[0050] As described above, according to the circulation-type wastewater treatment unit 1 of this modified example, the excess ozone gas generated in the treated water storage tank 30 is first sent to the wastewater adjustment tank 10 through the exhaust pipe 50, and then sent from the wastewater adjustment tank 10 to the biological treatment tank 20. The odor of the wastewater adjustment tank 10 is stronger than that of the biological treatment tank 20. Therefore, by supplying the excess ozone gas to the wastewater adjustment tank 10 before the biological treatment tank 20, it is possible to supply the highly active excess ozone gas to the wastewater adjustment tank 10. This makes it possible to efficiently reduce the odor. In addition, there is no need to provide a ventilation unit in the wastewater adjustment tank 10, which is located in the middle of the flow of the excess ozone gas, and a more compact configuration can be achieved. In addition, in FIG. 4, a ventilation unit may be provided in the wastewater adjustment tank 10. In the example shown in FIG. 4, the wastewater adjustment tank 10 and the biological treatment tank 20 are connected by the third exhaust pipe 53, so that when the biological treatment tank 20 is opened, the odor of the wastewater adjustment tank 10 may be felt in the biological treatment tank 20. By providing a ventilation unit in the wastewater adjustment tank 10, it is possible to release the odor in the wastewater adjustment tank 10 to the outside as necessary. Therefore, when the biological treatment tank 20 needs to be inspected, it is possible to suppress the odor of the wastewater adjustment tank 10 felt in the biological treatment tank 20. In addition, an opening and closing valve may be provided in the third exhaust pipe 53 and closed as necessary to prevent the odor of the wastewater adjustment tank 10 from reaching the biological treatment tank 20.

[0051] Second embodiment Next, a second embodiment will be described with reference to Fig. 5. In this description, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted. Fig. 5 is a diagram showing the configuration of an exhaust pipe 50 in the second embodiment.

[0052] As shown in FIG. 5, in the second embodiment, the exhaust pipe 50 forms a flow path through which odorous substances generated in the wastewater adjustment tank 10 and the biological treatment tank 20 flow into the treated water storage tank 30. The exhaust pipeline 50 includes a fourth exhaust pipe 54 connecting the treated water storage tank 30 and the biological treatment tank 20, and a fifth exhaust pipe 55 connecting the treated water storage tank 30 and the wastewater adjustment tank 10. The air intake port of the fourth exhaust pipe 54 in the biological treatment tank 20 is provided, for example, at an end of the ceiling of the biological treatment tank 20. The intake port of the fifth exhaust pipe 55 in the drainage adjustment tank 10 is provided, for example, at the end of the ceiling of the drainage adjustment tank 10.

[0053] Odor substances are supplied, for example, constantly from the biological treatment tank 20 to the treated water storage tank 30 through the fourth exhaust pipe 54. The odor substances supplied from the biological treatment tank 20 to the treated water storage tank 30 are ozone treated by the excess ozone gas filling the treated water storage tank 30. This reduces the odor of the odor substances supplied to the treated water storage tank 30.

[0054] The exhaust port of the fourth exhaust pipe 54 is provided at the end of the ceiling of the treated water storage tank 30. Therefore, the odorous substances supplied from the exhaust port are supplied to the gas phase of the treated water storage tank 30, that is, the area occupied by gas. However, the present invention is not limited to this example, and the odorous substances generated in the biological treatment tank 20 may be supplied to the liquid phase of the treated water storage tank 30, i.e., the area occupied by liquid. By contacting the odorous gas with the ozone gas in the liquid, the generation and outflow of excess ozone gas can be reduced. In other words, the exhaust port of the fourth exhaust pipe 54 in the treated water storage tank 30 may be located in the liquid phase of the treated water storage tank 30.

[0055] Odorants are supplied, for example, constantly from the wastewater adjustment tank 10 to the treated water storage tank 30 through the fifth exhaust pipe 55. The odorants supplied from the wastewater adjustment tank 10 to the treated water storage tank 30 are ozone treated by the excess ozone gas filling the treated water storage tank 30. This reduces the odor of the odorants supplied to the treated water storage tank 30. Thus, the odor in the wastewater adjustment tank 10 is reduced, and the excess ozone in the treated water storage tank 30 is effectively consumed.

[0056] The exhaust port of the fifth exhaust pipe 55 is provided at the end of the ceiling of the treated water storage tank 30. Therefore, the odorous substances supplied from the exhaust port are supplied to the gas phase of the treated water storage tank 30, that is, the area occupied by gas. However, without being limited to such an example, the odorous substances generated in the wastewater adjustment tank 10 may be supplied to the liquid phase of the treated water storage tank 30, i.e., the area occupied by liquid. In other words, the exhaust port of the fifth exhaust pipe 55 in the treated water storage tank 30 may be in the liquid phase of the treated water storage tank 30. By bringing the odorous gas and the ozone gas into contact with each other in the liquid, the generation and outflow of excess ozone gas can be reduced.

[0057] The treated water storage tank 30 is provided with a third exhaust unit 83 that exhausts air from the inside. The third exhaust unit 83 exhausts air from the inside of the treated water storage tank 30 to the outside. The third exhaust unit 83 is installed, for example, in a position farthest from the exhaust port of the fourth exhaust pipe 54 and the exhaust port of the fifth exhaust pipe 55 in the upper part of the treated water storage tank 30.

[0058] A deodorizer and an ozone decomposer are disposed inside the third exhaust unit 83. This decomposes the residual ozone contained in the residual gas discharged from the third exhaust unit 83. In addition, by disposing the deodorizer inside the third exhaust unit 83, the odor of the residual gas is further reduced.

[0059] <11.Summary> As described above, the odorous substances generated in the biological treatment tank 20 can be supplied to the treated water storage tank 30 through the fourth exhaust pipe 54, so that the odorous substances generated in the biological treatment tank 20 can be subjected to ozone treatment. This makes it possible to reduce the odor generated from the biological treatment tank 20. In addition, by supplying the odorous gas generated in the biological treatment tank 20 to the treated water storage tank 30, the outflow and emission of excess ozone gas outside the treated water storage tank 30 where ozone treatment is performed can be reduced, and deterioration of equipment and piping can be suppressed. In addition, the activity of the excess ozone gas is reduced by the reaction with odorous substances, and the burden of subsequent treatment of the excess ozone gas can be reduced.

[0060] Furthermore, since the odorous substances generated in the wastewater adjustment tank 10 can be supplied to the treated water storage tank 30 through the fifth exhaust pipe 55, the odorous substances generated in the wastewater adjustment tank 10 can be subjected to ozone treatment. This makes it possible to reduce the odor generated from the wastewater adjustment tank 10, as well as to reduce the activity of excess ozone gas, thereby reducing the burden of subsequent treatment of the excess ozone gas.

[0061] <12. Variations> Next, as a modification of the second embodiment, a modification of the exhaust pipe 50 will be described with reference to Fig. 6. Fig. 6 is a diagram showing a modification of the exhaust pipe 50 shown in Fig. 5. In this description, the same components as those in the second embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0062] In the exhaust pipe 50 according to this modification, the odorous substances are configured to flow through each tank in order. That is, the odorous substances generated in the wastewater adjustment tank 10 are supplied to the biological treatment tank 20, and are then supplied to the treated water storage tank 30 together with the odorous substances generated in the biological treatment tank 20. The exhaust pipeline 50 includes a fourth exhaust pipe 54 and a sixth exhaust pipe 56 that connects the wastewater adjustment tank 10 and the biological treatment tank 20. The intake port of the sixth exhaust pipe 56 in the wastewater adjustment tank 10 is provided, for example, at an end of the ceiling of the wastewater adjustment tank 10.

[0063] The exhaust port of the sixth exhaust pipe 56 is provided at an end of the ceiling of the biological treatment tank 20. Therefore, the odorous substances supplied from the exhaust port are supplied to the gas phase of the biological treatment tank 20, i.e., the area occupied by gas. However, this is not limited to the above example, and the odorous substances generated in the wastewater adjustment tank 10 may be supplied to the liquid phase of the biological treatment tank 20. In other words, the exhaust port of the sixth exhaust pipe 56 in the biological treatment tank 20 may be located in the liquid phase of the biological treatment tank 20. However, the present invention is not limited to this example, and the odorous substances generated in the wastewater adjustment tank 10 may be supplied to the liquid phase of the biological treatment tank 20, i.e., the region occupied by liquid. By contacting the odorous gas with the ozone gas in the liquid, the generation and outflow of excess ozone gas can be reduced.

[0064] Odor-causing substances are supplied from the wastewater adjustment tank 10 to the biological treatment tank 20 through the sixth exhaust pipe 56, for example, at all times. The odorous substances supplied to the biological treatment tank 20 are mixed with the odorous substances produced in the biological treatment tank 20, and are supplied to the treated water storage tank 30 through the fourth exhaust pipe 54. The surplus ozone gas filling the treated water storage tank 30 is used to perform ozone treatment on the mixed odorous substances supplied to the treated water storage tank 30. This reduces the odors produced from the wastewater adjustment tank 10 and the biological treatment tank 20.

[0065] That is, through the fourth exhaust pipe 54 and the sixth exhaust pipe 56, odorous substances generated in the wastewater adjustment tank 10 and the biological treatment tank 20, respectively, flow from the upstream to the downstream of the wastewater. In this modification, the third exhaust unit 83 is installed, for example, in the upper part of the treated water storage tank 30, at a position farthest from the exhaust port of the fourth exhaust pipe 54. This makes it possible to increase the opportunities for contact between the surplus ozone gas and odorous substances.

[0066] Moreover, the third exhaust unit 83 may be driven in response to the supply of odorous substances to the treated water storage tank 30. In this case, after the odorous substances react with the excess ozone gas, the residual gas filling the treated water storage tank 30 can be smoothly exhausted to the outside of the treated water storage tank 30.

[0067] As described above, in the circulation-type wastewater treatment unit 1 according to this modified example, odorous substances generated in the wastewater adjustment tank 10 and the biological treatment tank 20 are sent to the treated water storage tank 30 through the exhaust pipe 50. For this reason, it is sufficient to connect the exhaust pipe 50 to the tanks corresponding to the preceding and succeeding processes according to the wastewater treatment process, so that the exhaust pipe 50 can be easily installed.

[0068] Next, as a modification of the second embodiment, a modification of the exhaust pipe 50 will be described with reference to Fig. 7. Fig. 7 is a diagram showing a modification of the exhaust pipe 50 shown in Fig. 5. In this description, the same components as those in the second embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0069] In the exhaust pipe 50 according to this modification, the odorous substances are configured to flow through each tank in order. That is, the odorous substances generated in the biological treatment tank 20 are supplied to the wastewater adjustment tank 10, and are supplied to the treated water storage tank 30 together with the odorous substances generated in the wastewater adjustment tank 10. The exhaust pipeline 50 includes a fifth exhaust pipe 55 and a sixth exhaust pipe 56 .

[0070] Odorous substances are supplied, for example, constantly from the biological treatment tank 20 to the wastewater adjustment tank 10 through the sixth exhaust pipe 56. However, this is not limited to the above example, and the odorous substances generated in the biological treatment tank 20 may be supplied to the liquid phase of the wastewater adjustment tank 10. In other words, the exhaust port of the sixth exhaust pipe 56 in the wastewater adjustment tank 10 may be located in the liquid phase of the wastewater adjustment tank 10. The odorous substances supplied to the wastewater adjustment tank 10 are mixed with the odorous substances generated in the wastewater adjustment tank 10, and are supplied to the treated water storage tank 30 through the fifth exhaust pipe 55. The surplus ozone gas filling the treated water storage tank 30 is used to perform ozone treatment on the mixed odorous substances supplied to the treated water storage tank 30. This reduces the odors generated from the wastewater adjustment tank 10 and the biological treatment tank 20.

[0071] As described above, in the circulation-type wastewater treatment unit 1 of this modified example, odorous substances generated in the wastewater adjustment tank 10 and the biological treatment tank 20 are discharged to the treated water storage tank 30 through the exhaust pipe 50.

[0072] <Other Modifications> In each of the above-described embodiments, the circulating wastewater treatment unit 1 is configured as a circulating toilet 100, but is not limited to this. The circulating wastewater treatment unit 1 may treat and circulate domestic wastewater from, for example, a kitchen or a washbasin. In this case, the type of tank provided in the circulating wastewater treatment unit 1 is not limited to the above-described configuration and can be changed as desired. For example, the wastewater adjustment tank 10 may temporarily store domestic wastewater from a kitchen, a washbasin, or a combination of these.

[0073] Furthermore, the circulating wastewater treatment unit 1 may be part of a circulating wastewater treatment system equipped with a control unit that performs sensing using various sensors and drives a pump based on the results of the sensing.

[0074] In addition, although the biological treatment tank 20 has been shown to have a configuration including one anoxic tank 21 and one aerobic tank 22, the configuration of the biological treatment tank 20 can be changed as desired. That is, the numbers of anoxic tanks 21 and aerobic tanks 22 may be combined as desired, or only one of them may be used. Also, a single tank may be configured to have both an anaerobic section and an aerobic section. In other words, a single tank may be configured to repeatedly perform agitation and aeration.

[0075] Each of the first exhaust pipe 51 to the fifth exhaust pipe 55 described above may be provided with a blower that delivers gas. An exhaust fan for promoting the exhaust of gas may be provided in each of the first exhaust unit 81 to the third exhaust unit 83. The exhaust fan provided in each exhaust unit may be driven in response to the supply of excess ozone or odorous substances to each tank.

[0076] In the first embodiment and its modified example described above, a configuration is shown in which an exhaust pipe is provided to supply excess ozone gas to the wastewater adjustment tank 10, but this is not limited thereto. The exhaust pipe 50 may be configured so that excess ozone gas generated in the treated water storage tank 30 is supplied only to the biological treatment tank 20. In the first embodiment and its modified example described above, a configuration is shown in which an exhaust pipe is provided to supply excess ozone gas to the biological treatment tank 20, but this is not limited thereto. The exhaust pipe 50 may be configured so that excess ozone gas generated in the treated water storage tank 30 is supplied only to the wastewater adjustment tank 10.

[0077] In the second embodiment and its modified example described above, a configuration is shown in which an exhaust pipe is provided to supply the odorous substances generated in the wastewater adjustment tank 10 to the treated water storage tank 30, but this is not limited thereto. The exhaust pipe 50 may be configured to supply only the odorous substances generated in the biological treatment tank 20 to the treated water storage tank 30. In the second embodiment and its modified example described above, a configuration is shown in which an exhaust pipe is provided to supply odorous substances generated in the biological treatment tank 20 to the treated water storage tank 30, but this is not limited thereto. The exhaust pipe 50 may be configured to supply only odorous substances generated in the wastewater adjustment tank 10 to the treated water storage tank 30.

[0078] In addition, in each of the above-described embodiments, a configuration in which either excess ozone gas or odorous substances are supplied to each tank has been shown, but the present invention is not limited to such an embodiment. After the excess ozone gas is supplied to the biological treatment tank 20, the odorous substances generated in the biological treatment tank 20 and the excess ozone gas may be further supplied to the treated water storage tank 30, thereby circulating the excess ozone gas and odorous substances inside each tank.

[0079] In addition, in each of the above-described embodiments, it has been described that the excess ozone gas may be supplied to the gas phase or the liquid phase of the tank. However, it is more preferable to supply the excess ozone gas to the gas phase. In a small-scale water circulation system as described in this embodiment, the tank cannot be made large, so the water level in the tank may fluctuate greatly. Therefore, when the excess ozone gas is supplied to the liquid phase, depending on the water level in the tank to which the excess ozone gas is supplied, the excess ozone gas may not be easily supplied due to water pressure. Therefore, when the excess ozone gas is to be supplied more stably, it is preferable to supply the ozone gas to the gas phase.

[0080] Moreover, the organic matter supplied by the supply unit 90 is not limited to ethanol, but may be arbitrarily selected from liquid organic compounds having a reducing effect.

[0081] In each of the above-described embodiments, the case where the ozone gas generated by the ozone generator 40 is supplied to the treated water storage tank 30 has been described as an example. The number of ozone generators installed in the circulating wastewater treatment unit 1 is not limited to one. The circulating wastewater treatment unit 1 may have an ozone generator that supplies ozone gas to the wastewater adjustment tank 10. The ozone generator directly supplies the generated ozone gas to the wastewater adjustment tank 10. The ozone generator supplies the ozone gas to the wastewater in the wastewater adjustment tank 10, i.e., to the liquid phase of the wastewater adjustment tank 10. The ozone generator may supply the ozone gas to the gas phase of the wastewater adjustment tank 10. This makes it possible to further reduce the odor of the wastewater adjustment tank 10. The circulating wastewater treatment unit 1 may also have an ozone generator that supplies ozone gas to the biological treatment tank 20. The ozone generator directly supplies the generated ozone gas to the biological treatment tank 20. The ozone generator may supply the ozone gas to the liquid phase of the biological treatment tank 20 or to the gas phase. By supplying ozone gas to the wastewater adjustment tank 10 and / or the biological treatment tank 20, it is possible to reduce the molecular weight of surfactants and organic matter contained in the wastewater. By reducing the molecular weight of surfactants, foaming during aeration in the biological treatment tank 20 can be suppressed, and biological treatment can be stabilized. Furthermore, by reducing the molecular weight of organic matter, biological treatability by microorganisms is improved, decomposition is accelerated, and this leads to the efficiency of the regeneration and circulation cycle in the circulating water reclamation system.

[0082] When an ozone generator that supplies ozone gas to the wastewater adjustment tank 10 and / or the biological treatment tank 20 is installed, the ozone generator may be switched on / off (including on / off operation of the ozone generator as well as on / off supply by opening / closing a valve in an ozone supply flow path) according to the state of the wastewater adjustment tank 10 and / or the biological treatment tank 20. For example, the wastewater adjustment tank 10 may have an odor sensor that measures odor in the wastewater adjustment tank 10, or an ozone sensor that measures ozone concentration. In the first embodiment, for example, the control unit of the circulating wastewater treatment unit 1 normally turns off the operation of the ozone generator for the wastewater adjustment tank 10. In the first embodiment, for example, when the odor sensor exceeds a predetermined value despite the surplus ozone gas being supplied directly or indirectly from the treated water storage tank 30, the control unit turns on the operation of the ozone generator for the wastewater adjustment tank 10. Furthermore, in the first embodiment, for example, if the ozone sensor does not reach a predetermined value even though excess ozone gas is being supplied directly or indirectly from the treated water storage tank 30, the control unit turns on the operation of the ozone generator for the wastewater adjustment tank 10. Since the production of ozone gas consumes a relatively large amount of power, if the odor of the wastewater adjustment tank 10 is suppressed, it is possible to reduce power consumption by not operating the ozone generator for the wastewater adjustment tank 10. Furthermore, the use of ozone gas according to this embodiment is not limited to the above. For example, ozone gas may be added to pre-filtered raw water (MF filtered water after biological treatment) that flows into activated carbon or a cartridge filter (pre-filtration of the RO membrane) that pre-filters the raw water filtered by the RO membrane. This makes the raw water filtered by the RO membrane sterilized, and the sterilized raw water filtered by the RO membrane suppresses and reduces biofouling of the RO membrane. This makes it possible to stabilize filtration and extend the life of the RO membrane, which is a consumable material, leading to reduced running costs for users.

[0083] Although the preferred embodiment of the present disclosure has been described above, the present disclosure is not limited to the specific embodiment, and the present disclosure includes the invention described in the claims and its equivalents. In addition, the configurations of the devices described in the above embodiments and modifications can be partially omitted or combined as long as no technical contradiction occurs.

[0084] <Additional Notes> The matters described in the above embodiments will be supplemented below. (Appendix 1) A circulating wastewater treatment unit comprising a wastewater adjustment tank for storing wastewater from consumers, a biological treatment tank for performing biological treatment on wastewater supplied from the wastewater adjustment tank, a treated water storage tank for storing treated water obtained by biological treatment, a means for supplying ozone to the liquid phase of the treated water storage tank, and a means for supplying gas in the treated water storage tank to the biological treatment tank via the wastewater adjustment tank. (Appendix 2) A circulating wastewater treatment unit as described in Appendix 1, wherein the means for supplying gas in the treated water storage tank to the biological treatment tank via the wastewater adjustment tank supplies the gas to the liquid phase of the wastewater adjustment tank and the biological treatment tank. (Appendix 3) A circulating wastewater treatment unit as described in Appendix 1, wherein the means for supplying gas in the treated water storage tank to the biological treatment tank via the wastewater adjustment tank supplies the gas to the gas phase of the wastewater adjustment tank and the biological treatment tank. (Appendix 4) A circulating wastewater treatment unit as described in Appendix 1, wherein the means for supplying gas in the treated water storage tank to the biological treatment tank via the wastewater adjustment tank supplies the gas to the liquid phase of the wastewater adjustment tank and then to the gas phase of the biological treatment tank. (Appendix 5) A circulating wastewater treatment unit as described in Appendix 1, wherein the means for supplying gas in the treated water storage tank to the biological treatment tank via the wastewater adjustment tank supplies the gas to the gas phase of the wastewater adjustment tank and then to the liquid phase of the biological treatment tank. (Appendix 6) A system having a configuration according to any one of the inventions set forth in (Appendix 1) to (Appendix 5). [Explanation of symbols]

[0085] 1...Circulating wastewater treatment unit 10…Drainage adjustment tank 20...Biological treatment tank 30…Treated water storage tank 40…Ozone generator 50…Exhaust pipe 90…Supply section 100...Circulating toilet

Claims

1. An ozone generator that generates ozone gas by an ultraviolet method (mercury-free UV lamp (excimer lamp) method), means for decolorizing, sterilizing, or deodorizing the water to be treated, which is the object of treatment, with the ozone gas A circulating wastewater treatment unit comprising.

2. An ozone sensor for measuring the ozone concentration, means for turning on or off the generation of ozone gas by the ozone generator based on the ozone concentration measured by the ozone sensor The circulating wastewater treatment unit according to claim 1, comprising.

3. Comprising at least one of a wastewater adjustment tank, a biological treatment tank, and a treated water storage tank, The means for decolorizing, sterilizing, or deodorizing decolorizes, sterilizes, or deodorizes the water to be treated stored in at least one of the wastewater adjustment tank, the biological treatment tank, and the treated water storage tank. The circulating wastewater treatment unit according to claim 1.

4. Comprising at least one of a wastewater adjustment tank, a biological treatment tank, and a treated water storage tank, The means for decolorizing, sterilizing, or deodorizing decolorizes, sterilizes, or deodorizes the water to be treated stored in at least one of the wastewater adjustment tank, the biological treatment tank, and the treated water storage tank. The circulating wastewater treatment unit according to claim 2.

5. By an ultraviolet method (mercury-free UV lamp (excimer lamp) method), ozone gas is generated from an ozone generator, The water to be treated, which is the object of treatment, is decolorized, sterilized, or deodorized with the ozone gas, An ozone sensor measures the ozone concentration of the water to be treated stored in at least one of a wastewater adjustment tank, a biological treatment tank, and a treated water storage tank, A method of turning on or off the generation of ozone gas by the ozone generator based on the ozone concentration measured by the ozone sensor.

Images