Water treatment device, method, program, and system

Abstract

This water treatment device comprises: a wastewater adjustment tank for retaining wastewater; a first measurement means for measuring the quality of the wastewater flowing into the wastewater adjustment tank; a biotreatment tank in which a treatment to the wastewater supplied from the wastewater adjustment tank can be switched by on / off aeration switching; and a control means for controlling the aeration time during the treatment on the basis of measurement results from the first measurement means.

Description

Water treatment device, method, program, and system

[0001] The present disclosure relates to a water treatment device, method, program, and system.

[0002] Patent Document 1 describes a method for treating nitrogen-containing wastewater using an intermittent aeration system that can efficiently remove nitrogen from nitrogen-containing wastewater such as secondary sewage treatment water, leachate from garbage landfills, rivers, human waste, and industrial wastewater.

[0003] Japanese Patent Application Publication No. 11-253990

[0004] In Patent Document 1, the pH change in a reaction tank undergoing intermittent aeration is continuously measured with a pH meter, the end of the nitrification reaction is detected from the inflection point, and the nitrification time, which is the time from the start of nitrification to the appearance of the inflection point, is calculated. The raw water nitrogen concentration is estimated from this nitrification time and a predetermined nitrification rate. The raw water flow rate is controlled based on this raw water nitrogen concentration to maintain a constant nitrogen load in the reaction tank.

[0005] However, Patent Document 1 assumes that nitrogen will be efficiently removed from nitrogen-containing wastewater such as secondary sewage treatment water, leachate from landfills, rivers, human waste, industrial wastewater, etc. In other words, Patent Document 1 assumes that nitrogen will be efficiently removed from sludge that has been homogenized to a certain extent, and does not assume operation in an environment where the quality of the water to be treated fluctuates.

[0006] An object of the present disclosure is to provide a single-tank nitrification / denitrification treatment system that is capable of efficient nitrification / denitrification in an environment where the water quality of the water to be treated varies.

[0007] The water treatment device of this embodiment comprises a wastewater adjustment tank for storing wastewater, a first measuring means for measuring the water quality of the wastewater flowing into the wastewater adjustment tank, a biological treatment tank that can switch the treatment of the wastewater supplied from the wastewater adjustment tank by switching aeration on and off, and a control means for controlling the aeration time in the treatment based on the measurement results of the first measuring means.

[0008] According to the present disclosure, it is possible to provide a single-tank nitrification / denitrification treatment system that is capable of efficient nitrification / denitrification even in an environment where the water quality of the water to be treated varies.

[0009] FIG. 1 is an overall configuration diagram of an example of a water treatment device 1. FIG. 2 is a flowchart showing an example of the operation of the control unit 50 when setting parameters related to biological denitrification. FIG. 3 is a flowchart showing an example of the operation of the control unit 50 when executing control related to biological denitrification. FIG. 4 is a schematic diagram showing an example of a process related to biological denitrification. FIG. 5 is a schematic diagram showing another example of a process related to biological denitrification. FIG. 6 is a diagram showing changes in ORP, DO, and pH during an aeration cycle: 3 hours and an anaerobic cycle: 1 hour. FIG. 7 is a diagram showing changes in NPOC and TN during an aeration cycle: 3 hours and an anaerobic cycle: 1 hour. FIG. 8 is a flowchart showing another example of the operation of the control unit 50 when setting parameters related to biological denitrification. FIG. 9 is a block diagram showing the basic hardware configuration of a computer 90.

[0010] First Embodiment Hereinafter, a first embodiment will be described in detail with reference to the drawings. In the drawings for explaining the embodiments, the same components are generally designated by the same reference numerals, and repeated description thereof will be omitted.

[0011] <1. Overview> The water treatment device according to this embodiment is a device for circulating and regenerating wastewater discharged from a consumer (hereinafter simply referred to as wastewater). The regenerated water can be used for daily life purposes, such as flushing toilets, baths, showers, laundry, and dishwashing. The regenerated water may also be used as drinking water. In other words, the water treatment device is a small-sized circulating water treatment device.

[0012] A water treatment device, for example, includes a treatment tank module that compactly combines a wastewater adjustment tank, a biological treatment tank, and a treated water storage tank to treat and purify wastewater (domestic wastewater, sewage, etc.) discharged from consumers. The biological treatment tank performs a single-tank nitrification / denitrification process, switching between nitrification and denitrification at a predetermined time ratio. The water treatment device monitors the amount of human waste input into the wastewater adjustment tank and sets the time for nitrification and denitrification based on the monitoring results. The water treatment device also adjusts the amount of hydrogen donor added when switching from nitrification to denitrification based on the monitoring results.

[0013] 2. Overall Configuration The overall configuration of a water treatment device 1 according to this embodiment will be described. Fig. 1 is a diagram showing the overall configuration of an example of a water treatment device 1. Fig. 1 shows an example in which the water treatment device 1 is used in a circulation toilet 100.

[0014] The circulating toilet 100 according to this embodiment is used, for example, as a toilet in a residence, vacation home, mountain hut, temporary housing, or mobile home constructed in an area lacking water supply and sewage systems, such as a mountainous region. The circulating toilet 100 is also used, for example, as a temporary toilet installed at an outdoor event venue, a construction site, or a disaster evacuation shelter. By using the circulating toilet 100, wastewater can be treated and reused as circulated water, so the toilet can be used even in areas without water supply and sewage systems.

[0015] The water treatment device 1 according to this embodiment can be used in applications other than the recycling toilet 100. The water treatment device 1 may be used, for example, to regenerate wastewater used in a kitchen, a washroom (laundry), a bathroom, etc. In this case, for example, a filtration unit, a UV sterilization unit, etc. may be installed in the water treatment device 1 between the final-stage water tank and the actual water use by the consumer. The filtration unit may be realized by physical filtration using, for example, a reverse osmosis membrane, a nanofiltration membrane, an ultrafiltration membrane, or a microfiltration membrane, or by biological filtration or chemical filtration using activated carbon, zeolite, ion exchange resin, etc. The UV sterilization unit sterilizes the water. Furthermore, in the water treatment device 1, toilet wastewater and wastewater used in a kitchen, washroom (laundry), bathroom, etc. may be treated in different treatment systems.

[0016] As shown in FIG. 1 , the water treatment device 1 is connected to a toilet bowl 2 via multiple drain pipes. The water treatment device 1 includes a wastewater adjustment tank 10, a biological treatment tank 20, a treated water storage tank 30, and an ozone generator 40. The wastewater adjustment tank 10, the biological treatment tank 20, and the treated water storage tank 30 are connected via multiple drain pipes to allow water to be transported between the tanks. Each of the multiple drain pipes is provided with a pump, and the operation of each pump is controlled so that the water level in the destination tank remains within a predetermined range and so that constant, continuous operation is achieved as much as possible. Note that FIG. 1 is merely an example, and the water treatment device 1 may have other configurations. For example, the wastewater adjustment tank 10, the biological treatment tank 20, and the treated water storage tank 30 may be included in a single module that performs a series of processes. Furthermore, at least some of the pumps in the water treatment device 1 are not required, and water may be transported using other physical phenomena, such as gravity, overflow, or the siphon principle.

[0017] The water treatment device 1 includes a control unit 50. The control unit 50 controls, for example, the components included in the water treatment device 1. The water treatment device 1 also includes a sensor unit for detecting various physical properties, for example, in the wastewater adjustment tank 10, the biological treatment tank 20, the treated water storage tank 30, or in pipes connected thereto.

[0018] 3. Wastewater adjustment tank 10 The wastewater adjustment tank 10 is disposed downstream of the toilet bowl 2 and temporarily stores the wastewater discharged from the toilet bowl 2. For example, a pulverizing pressure pump may be installed in the toilet bowl 2. The pulverizing pressure pump pulverizes waste and the like contained in the wastewater and sends the pulverized waste to the wastewater adjustment tank 10 together with the wastewater.

[0019] The wastewater adjustment tank 10 is provided with a blower 11. The blower 11 continuously or intermittently sends air into the interior of the wastewater adjustment tank 10. The air sent out from the blower 11 agitates the wastewater stored inside 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.

[0020] A measuring instrument 12 is installed in or near the wastewater adjustment tank 10 to measure the quality of the wastewater flowing into the wastewater adjustment tank 10. Specifically, the measuring instrument 12 is installed, for example, in the flow path before the wastewater adjustment tank 10, at the inlet of the wastewater adjustment tank 10, in a space within the wastewater adjustment tank 10, or in the wastewater within the wastewater adjustment tank 10. The measuring instrument 12 measures, for example, the electrical conductivity of the wastewater. The measuring instrument 12 transmits the EC value as the measurement result to the control unit 50.

[0021] <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 organic compounds contained in the wastewater discharged from the wastewater adjustment tank 10. The biological treatment tank 20 also performs biological denitrification, which removes nitrogen compounds through the action of microorganisms. Biological denitrification combines aerobic bacteria and facultative anaerobic bacteria to decompose nitrogen compounds and carbon compounds in the wastewater. Biological denitrification includes a nitrification process carried out in an aerobic environment and a denitrification process carried out in an anoxic environment.

[0022] In the nitrification process, nitrogen components in wastewater are oxidized to nitrite or nitrate by nitrifying bacteria. Nitrifying bacteria are a type of aerobic bacteria that require the presence of sufficient dissolved oxygen in the tank.

[0023] In the denitrification process, the water nitrified in the nitrification process is placed under anaerobic conditions without dissolved oxygen, and anaerobic respiration by denitrifying bacteria is utilized to reduce nitrite and nitrate to nitrogen gas.

[0024] The biological treatment tank 20 is formed, for example, as a single tank, and the nitrification process and the denitrification process are carried out in this single tank. The biological treatment tank 20 is equipped with an agitator 23, a membrane filtration unit 25, a blower 26, and a blower 27. The agitator 23 is realized, for example, by a mixer with agitating blades. The agitator 23 agitates the mixed liquid by rotating the agitating blades, for example, at a timing based on the control of the control unit 50, thereby promoting contact between the microorganisms contained in the mixed liquid and organic matter, etc. In this way, the agitator 23 is driven in the denitrification process.

[0025] The membrane filtration unit 25 is realized by, for example, at least one of an MF (microfiltration membrane), an UF (ultrafiltration membrane), an NF (nanofiltration membrane), a ceramic filter, and a metal membrane. 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.

[0026] The blower 26 supplies air (or oxygen) into the inside of the biological treatment tank 20, for example, at a timing based on the control of the control unit 50. The air supplied from the blower 26 maintains aerobic circulation in the nitrification process.

[0027] The blower 27 is installed, for example, below the membrane filtration unit 25. The blower 27 supplies air (or oxygen) to the membrane filtration unit 25, for example, at a timing based on the control of the control unit 50. The membrane filtration unit 25 is cleaned by the air supplied from the blower 27.

[0028] A supply unit 80 is installed in the biological treatment tank 20. The supply unit 80 supplies a hydrogen donor to the biological treatment tank 20, for example, at a timing based on the control of the control unit 50. The hydrogen donor is a substance that provides hydrogen to other substances in the biological treatment tank 20 to reduce them, and is itself dehydrogenated and oxidized. The hydrogen donor may be, for example, an alcohol such as methanol or ethanol, or a sugar such as glucose.

[0029] The biological treatment tank 20 , the agitator 23 , the membrane filtration unit 25 , the blower 26 , the blower 27 , and the supply unit 80 may be said to form a biological treatment module 3 .

[0030] 5. Control Unit 50 The control unit 50 controls the overall operation of the water treatment device 1. Specifically, for example, the control unit 50 controls biological denitrification in the biological treatment tank 20. For example, the control unit 50 sets cycles for the nitrification process and the denitrification process based on the EC value of the wastewater flowing into the wastewater adjustment tank 10. Hereinafter, the cycle for the nitrification process will be referred to as an aeration cycle, and the cycle for the denitrification process will be referred to as an anaerobic cycle.

[0031] More specifically, for example, when the water treatment device 1 is started up, the control unit 50 determines whether the EC value measured by the measuring device 12 is equal to or greater than a predetermined threshold, for example, 1000 μS / cm. If the EC value is equal to or greater than the threshold, the control unit 50 considers that the water use includes sewage wastewater. The control unit 50 counts the number of times an EC value equal to or greater than the threshold is measured during a series of biological denitrification processes performed in the biological treatment tank 20. In this embodiment, the series of biological denitrification processes includes, for example, a charging process, a nitrification process, a denitrification process, and an extraction process. The charging process is a process of charging wastewater into the biological treatment tank 20. The extraction process is a process of extracting biologically treated water from the biological treatment tank 20.

[0032] Furthermore, for example, after the water treatment device 1 has reached a steady-state operating state, the control unit 50 may determine whether the difference between the EC value measured by the measuring device 12 and the EC value measured for the treated water withdrawn from the biological treatment tank 20 is equal to or greater than a predetermined threshold, e.g., 1000 μS / cm. If the difference is equal to or greater than the threshold, the control unit 50 considers the water use to include sewage and wastewater. Repeated water purification through circulation results in a high EC value for the reclaimed water. Therefore, by calculating the difference between the EC value of the wastewater input into the wastewater adjustment tank 10 and the EC value of the reclaimed water, it is possible to accurately detect the input of sewage and wastewater. The control unit 50 counts the number of times a difference value equal to or greater than the threshold is measured during the series of biological denitrification processes performed in the biological treatment tank 20.

[0033] The treated water withdrawn from the biological treatment tank 20 can be described as treated water after treatment in the biological treatment tank 20, and may be water in the path from the membrane filtration unit 25 of the biological treatment tank 20 to the toilet 2. If possible, it is desirable that the water be water in the path from the treated water storage tank 30 to the toilet 2. The EC value of the treated water withdrawn from the biological treatment tank 20 is measured by a measuring instrument 28 installed, for example, in the flow path from the biological treatment tank 20 to the treated water storage tank 30, within the treated water storage tank 30, or in the flow path from the treated water storage tank 30 to the toilet 2.

[0034] The control unit 50 sets the aeration cycles and anaerobic cycles for the next series of processes based on the count values ​​counted during the previous series of processes. The control unit 50, for example, sets values ​​based on the count values ​​so that a predetermined ratio of aeration cycles to anaerobic cycles is maintained. Specifically, the control unit 50, for example, sets values ​​based on the count values ​​so that a ratio of aeration cycles to anaerobic cycles is maintained at 3:1. The predetermined ratio is, for example, a ratio that has been determined through prior experiments to be capable of stable biological denitrification. For example, a ratio of aeration cycles to anaerobic cycles of 3:1 has been determined to be capable of stable biological denitrification. Depending on the environment, the ratio may vary, such as a ratio of aeration cycles to anaerobic cycles of 1:3. The optimal ratio is set according to the environment, and the processing of this embodiment is carried out.

[0035] That is, when the count value is equal to or greater than the first count value, the control unit 50 sets the aeration cycle to 3 hours and the anaerobic cycle to 1 hour. Furthermore, when the count value is equal to or greater than the second count value but less than the first count value, the control unit 50 sets the aeration cycle to 1 hour and the anaerobic cycle to 20 minutes. Furthermore, when the count value is equal to or greater than the third count value but less than the second count value, the control unit 50 sets the aeration cycle to 30 minutes and the anaerobic cycle to 10 minutes. The aeration cycle value and the anaerobic cycle value are merely examples, and may be longer than (aeration cycle value, anaerobic cycle value) = (3 hours, 1 hour) or shorter than (30 minutes, 10 minutes). The control unit 50 may determine the duration of the aeration cycle and the anaerobic cycle so as to maintain an optimal ratio according to the environment, taking into account not only the count value but also the flow rate of wastewater supplied from the wastewater adjustment tank 10 to the biological treatment tank 20 measured by a flow meter.

[0036] Furthermore, if the count value during the series of steps is 0, the control unit 50 sets the aeration cycle to 0 minutes and the anaerobic cycle to 0 minutes. This eliminates the aeration cycle and anaerobic cycle from the series of steps, leaving only the introduction step and the withdrawal step. This eliminates the need for unnecessary aeration, saving electricity. Furthermore, this reduces consumption due to the addition of hydrogen donors and shortens the time cycle required for the series of steps in water treatment.

[0037] In the above, the control unit 50 sets the aeration cycle and anaerobic cycle in the next series of steps based on the count values ​​counted during the previous series of steps, but the control unit 50 may also set the aeration cycle in the next series of steps based on the count values ​​counted during the previous series of steps, and set the anaerobic cycle based on the set aeration cycle.

[0038] The control unit 50 sets the amount of hydrogen donor to be input from the supply unit 80 in the next series of steps based on the count value counted during the previous series of steps. Note that the control unit 50 may determine the amount of hydrogen donor by taking into consideration, in addition to the count value, the amount of wastewater supplied from the wastewater adjustment tank 10 to the biological treatment tank 20, measured by a flow meter. For example, the control unit 50 determines the amount of hydrogen donor by multiplying the measured amount of wastewater by the ratio of a predetermined amount of wastewater. The amount of wastewater supplied from the wastewater adjustment tank 10 to the biological treatment tank 20 may be calculated based on the volume of treated water withdrawn from the biological treatment tank 20.

[0039] Based on the set aeration cycle and anaerobic cycle, the control unit 50 controls, for example, the pump 66, the pump 67, the agitator 23, the blower 26, the blower 27, and the supply unit 80. Furthermore, the control unit 50 controls the supply unit 80 based on the set amount of hydrogen donor.

[0040] Specifically, for example, the control unit 50 controls the pump 66 in a series of steps to supply wastewater from the wastewater adjustment tank 10 to the biological treatment tank 20. The control unit 50 drives the blower 26 as wastewater is introduced, starting aeration in the biological treatment tank 20. The control unit 50 stops the pump 66 when a predetermined amount of wastewater has been introduced. The control unit 50 starts an aeration cycle when the introduction of wastewater is stopped. The control unit 50 stops the blower 26 when a predetermined time has passed and the aeration cycle has ended. The control unit 50 stops the blower 26 and simultaneously controls the supply unit 80 to supply a set amount of hydrogen donor to the biological treatment tank 20. The control unit 50 stops the blower 26 and simultaneously drives the agitator 23. The control unit 50 starts an anaerobic cycle when the blower 26 is stopped. When a predetermined time has elapsed and the anaerobic cycle has ended, the control unit 50 drives the blower 27 and the pump 67 at the same time, and draws the treated water from the biological treatment tank 20 while filtering the treated water through the membrane filtration unit 25.

[0041] By supplying a hydrogen donor at the timing when the anoxic cycle is started, for example, an anoxic atmosphere without dissolved oxygen and a hydrogen donor necessary for reducing oxygen molecules of nitrite and nitrate are present, which effectively promotes the reduction reaction of oxygen molecules of nitrite and nitrate in the denitrification process.

[0042] 6. Treated Water Storage Tank 30 The treated water storage tank 30 is a tank that stores treated water obtained by biologically treating wastewater. That is, the treated water storage tank 30 stores treated water to be supplied to the toilet 2. In other words, the treated water storage tank 30 stores treated water obtained by treating wastewater in the biological treatment tank 20. A pipe 41 leading to the toilet 2 is connected to the treated water storage tank 30.

[0043] A pump 63 provided in the pipe 41 supplies treated water for flushing the toilet 2 to the toilet 2 through the pipe 41. The pump 63 is driven, for example, when the toilet 2 is used. The pump 63 may be driven in response to an instruction from a user or in response to detection of use of the toilet 2. Furthermore, if it is expected that the recycling toilet 100 will not be used for an extended period of time, the pump 63 may be driven at predetermined intervals.

[0044] The treated water storage tank 30 is supplied with ozone gas generated by, for example, an ozone generator 40. 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. The ozone generator 40 may also supply the ozone gas into the gas phase of the treated water storage tank 30.

[0045] Methods for generating ozone gas using 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). The ultraviolet method (mercury-free UV lamp (excimer lamp) method) does not produce harmful nitrogen oxides from nitrogen present in the atmosphere during ozone gas generation, and can generate ozone gas with few impurities. Generating ozone gas with few impurities can reduce the operating time of the ozone generator 40, reduce power consumption, and extend the life of the ozone generator 40. Generating ozone gas with few impurities can reduce the size of water circulation system equipment and reduce the number of deteriorated or damaged parts, which also leads to reduced maintenance frequency.

[0046] In the treated water storage tank 30, the ozone gas decolorizes, sterilizes, and deodorizes the treated water (hereinafter referred to as ozone treatment) due to its strong oxidizing power. Of the ozone gas supplied to the treated water, the surplus ozone gas (gas in the tank) that is not used in the ozone treatment of the treated water fills the space formed above the treated water storage tank 30 and is then supplied to the wastewater adjustment tank 10 and / or the biological treatment tank 20 for reuse. This makes it possible, for example, to deodorize the wastewater adjustment tank 10, the biological treatment tank 20, and the treated water storage tank 30, sterilize the water in the wastewater adjustment tank 10, the biological treatment tank 20, and the treated water storage tank 30, and decolorize the water in the wastewater adjustment tank 10, the biological treatment tank 20, and the treated water storage tank 30, etc.

[0047] 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 existing water purification facilities, the time that water is stored in the decolorization tank (ozone treatment tank) is short, so the ozone gas and water need to be brought into contact with each other for a short period of time. On the other hand, in this embodiment, the treated water is stored in the treated water storage tank 30 for a long period of time, so the ozone gas and the treated water are in contact with each other for a long period of time. Due to this difference in storage time, 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.

[0048] 7. Operation of Biological Treatment Tank 20 The operation of biological denitrification in the biological treatment tank 20 will be described in detail below.

[0049] (Setting of parameters related to biological denitrification) Fig. 2 is a flowchart showing an example of the operation of the control unit 50 when setting parameters related to biological denitrification. The control unit 50 performs, for example, the process shown in Fig. 2 between a series of steps related to biological denitrification.

[0050] In step S11, the control unit 50 acquires the EC value measured by the measuring instrument 12. Specifically, for example, the measuring instrument 12 measures the EC value of the wastewater supplied to the installation location at a predetermined interval. The measuring instrument 12 transmits the measured EC value to the control unit 50.

[0051] In step S12, the control unit 50 measures a predetermined count value based on the EC value measured by the measuring device 12. Specifically, for example, after the water treatment device 1 is started up, the control unit 50 counts the number of times that the EC value measured by the measuring device 12 becomes equal to or greater than a predetermined threshold value, for example, 1000 μS / cm, until a predetermined period of time has elapsed or a predetermined number of steps have been performed.

[0052] Furthermore, for example, after a predetermined period of time has elapsed since the water treatment device 1 was started up, or after a predetermined number of steps have been performed, that is, after the water treatment device 1 has entered a steady operating state, the control unit 50 counts the number of times that the difference between the EC value measured by the measuring device 12 and the EC value measured for the treated water withdrawn from the biological treatment tank 20 has reached a predetermined threshold value, for example, 1000 μS / cm. Note that the requirement is not limited to the elapse of a predetermined period of time after the water treatment device 1 was started up, or the execution of a predetermined number of steps, and may be, for example, until the EC value reaches a predetermined value.

[0053] In step S13, the control unit 50 determines whether the series of steps related to biological denitrification have been completed. Specifically, for example, the control unit 50 determines whether the feeding step, nitrification step, denitrification step, and extraction step have been completed. If they have not been completed, the control unit 50 shifts the process to step S11 and repeats the operations of steps S11 to S13 until the series of steps have been completed. If they have been completed, the control unit 50 shifts the process to step S14.

[0054] In step S14, the control unit 50 sets parameters related to biological denitrification based on the count value. Specifically, for example, the control unit 50 sets the aeration cycle and the anaerobic cycle in the next series of steps based on the count value. Specifically, for example, if the count value is 0, the control unit 50 sets the aeration cycle to 0 minutes and the anaerobic cycle to 0 minutes. For example, if the count value is 1 or more, the control unit 50 sets values ​​based on the count value so that the aeration cycle and the anaerobic cycle maintain a predetermined ratio, for example, 3:1.

[0055] Furthermore, for example, based on the count value, the control unit 50 sets the amount of hydrogen donor to be introduced from the supply unit 80 in the next series of steps. Specifically, for example, based on the count value, the control unit 50 sets the amount of hydrogen donor in the next series of steps to be count value x n (ml).

[0056] (Control of Biological Denitrification) Fig. 3 is a flowchart showing an example of the operation of the control unit 50 when executing control of biological denitrification. The process shown in Fig. 3 represents, for example, the process of the control unit 50 in a series of steps related to biological denitrification.

[0057] Figure 4 is a schematic diagram showing an example of a process related to biological denitrification. Figure 5 is a schematic diagram showing another example of a process related to biological denitrification. The examples shown in Figures 4 and 5 show the treatment in the biological treatment tank 20 and the timing of measuring the EC value. The example shown in Figure 4 shows a case where the aeration cycle is 3 hours and the anoxic cycle is 1 hour. The example shown in Figure 5 shows a case where the aeration cycle and the anoxic cycle are 0 minutes.

[0058] In step S21, the control unit 50 starts the introduction of wastewater into the biological treatment tank 20 and aeration. Specifically, for example, the control unit 50 controls the pump 66 to supply wastewater from the wastewater adjustment tank 10 to the biological treatment tank 20. In addition to the introduction of wastewater, the control unit 50 drives the blower 26 to start aeration in the biological treatment tank 20.

[0059] In step S22, when a predetermined amount of wastewater has been introduced, the control unit 50 stops the pump 66 and starts an aeration cycle. Specifically, the control unit 50 stops the pump 66 when predetermined conditions are met. The predetermined conditions include, for example: - The amount of water stored in the wastewater adjustment tank 10 has reached a predetermined volume; - A predetermined amount of wastewater has been supplied to the biological treatment tank 20; - The amount of water stored in the biological treatment tank 20 has reached a predetermined volume.

[0060] When the control unit 50 stops the introduction of wastewater, it starts counting the aeration cycles set in the previous series of steps.

[0061] In step S23, when the aeration cycle ends, the control unit 50 stops the blower 26 and controls the supply unit 80. Specifically, for example, the control unit 50 stops the blower 26 when three hours have passed since the start of the aeration cycle. At the same time as stopping the blower 26, the control unit 50 controls the supply unit 80 to add the amount of hydrogen donor set in the previous series of steps to the biological treatment tank 20.

[0062] When the aeration cycle ends, the control unit 50 starts an anaerobic cycle and drives the agitator 23. Specifically, for example, when the aeration cycle ends, the control unit 50 starts counting the anaerobic cycle set in the previous series of steps.

[0063] In step S24, when the anaerobic cycle is completed, the control unit 50 withdraws the treated water from the biological treatment tank 20. Specifically, for example, when one hour has elapsed since the start of the anaerobic cycle, the control unit 50 drives the pump 67 to filter the treated water using the membrane filtration unit 25 while withdrawing the treated water from the biological treatment tank 20. The control unit 50 drives the pump 67 and the blower 27 at the same time to clean the membrane filtration unit 25.

[0064] FIG. 6 is a graph showing the changes in ORP (Oxidation-Reduction Potential), DO (Dissolved Oxygen), and pH during an aeration cycle of 3 hours and an anoxic cycle of 1 hour. The example shown in FIG. 6 shows the changes in each value when wastewater is continuously introduced, rather than when wastewater is discontinuously introduced as shown in FIGS. 4 and 5 . In FIG. 6 , the horizontal axis represents time (h), and the vertical axis represents ORP, DO, and pH. Measuring instruments for measuring ORP, DO, and pH are installed, for example, in the biological treatment tank 20. FIG. 6 shows that stable biological denitrification can be expected in the biological treatment tank 20 by setting the aeration cycle to 3 hours and the anoxic cycle to 1 hour, even when wastewater containing human waste is continuously introduced.

[0065] FIG. 7 shows the trends in NPOC (non-purgeable organic carbon) and TN (total nitrogen) during an aeration cycle of 3 hours and an anaerobic cycle of 1 hour. The example shown in FIG. 7 shows the trends in each value when wastewater is continuously introduced, rather than when wastewater is introduced discontinuously as shown in FIGS. 4 and 5 . In FIG. 7 , the horizontal axis represents time (h), and the vertical axis represents NPOC and TN. NPOC is calculated, for example, based on TOC, and a measuring device for measuring TOC is installed, for example, in the biological treatment tank 20. TN is calculated, for example, based on EC values, and a measuring device for measuring EC values ​​is installed, for example, in the biological treatment tank 20. FIG. 7 shows that even when wastewater containing human waste is continuously introduced, nitrogen components are completely removed by setting the aeration cycle to 3 hours and the anaerobic cycle to 1 hour.

[0066] As described above, in the above embodiment, the water treatment device 1 includes a wastewater adjustment tank 10 that stores wastewater. The water treatment device 1 also includes a first measuring means (measuring instrument 12) that measures the water quality of wastewater flowing into the wastewater adjustment tank. The water treatment device 1 also includes a single-tank biological treatment tank 20 that switches between nitrification and denitrification treatments on the wastewater supplied from the wastewater adjustment tank 10 by switching aeration on and off. The water treatment device 1 also includes a control means (controller 50) that controls the aeration time for the nitrification treatment based on the measurement results of the first measuring means 12. This allows the water treatment device 1 to control the optimal aeration amount (including aeration time) for the nitrification reaction in the single-tank biological treatment tank 20 based on the water quality of the wastewater input into the wastewater adjustment tank 10.

[0067] Therefore, the water treatment device 1 according to this embodiment can provide a single-tank nitrification / denitrification treatment system that can efficiently perform nitrification / denitrification even in an environment where the quality of the supplied water to be treated fluctuates. Furthermore, the water treatment device 1 can reduce power consumption by reducing blower time. Furthermore, the water treatment device 1 can add an optimal amount of hydrogen donor according to the state of the wastewater, thereby reducing the consumption of hydrogen donor.

[0068] In the above embodiment, the control means 50 controls the aeration time based on the number of times the measurement value measured by the first measurement means 12 exceeds the threshold value, thereby enabling the water treatment device 1 to switch between nitrification treatment and denitrification treatment with high accuracy.

[0069] In the above embodiment, the control means 50 controls the aeration time based on the number of times the measurement value measured by the first measurement means 12 exceeds the threshold value and the amount of wastewater supplied from the wastewater adjustment tank 10 to the biological treatment tank 20. This enables the water treatment device 1 to switch between nitrification treatment and denitrification treatment with higher accuracy.

[0070] In the above embodiment, the water treatment device 1 also includes a supplying means (supply unit 80) that supplies a hydrogen donor to the biological treatment tank 20. The control means 50 sets the amount of hydrogen donor based on the number of times the measurement value measured by the first measuring means 12 exceeds a threshold value, and supplies the set amount of hydrogen donor when aeration is turned off. In this way, adding the hydrogen donor when aeration is turned off enables immediate switching from an aerobic environment to an anaerobic state. This allows the environment to be instantly switched, as if the aerobic reaction and the anaerobic reaction were being carried out in separate tanks.

[0071] Normally, after the aerobic environment is established, the air dissolved in the liquid is not released, preventing the transition to an anaerobic state, resulting in reduced treatment efficiency or prolonged treatment times. However, by adding a hydrogen donor when the aeration is switched off, the environment within the tank is instantly switched over, enabling efficient nitrification and denitrification in a single biological treatment tank 20.

[0072] Furthermore, the water treatment device 1 is capable of controlling the amount of hydrogen donor suitable for switching from nitrification reaction to denitrification reaction in the single-tank biological treatment tank 20 based on the quality of the wastewater fed into the wastewater adjustment tank 10.

[0073] Furthermore, in the above embodiment, the water treatment device 1 includes an injection means 80 that injects a hydrogen donor into the biological treatment tank 20. The control means 50 sets the amount of hydrogen donor based on the number of times the measurement value measured by the first measurement means 12 exceeds the threshold value and the amount of wastewater supplied from the wastewater adjustment tank 10 to the biological treatment tank 20, and then injects the set amount of hydrogen donor while switching off aeration. Because the amount of hydrogen donor is set based also on the amount of wastewater supplied from the wastewater adjustment tank 10 to the biological treatment tank 20, it is possible to set a more appropriate amount of hydrogen donor and reduce the amount of hydrogen donor used.

[0074] Furthermore, in the above embodiment, the water treatment device 1 has a second measuring means 28 that measures the water quality of the treated water after treatment in the biological treatment tank 20. The control means 50 controls the aeration time based on the number of times the difference between the measurement value measured by the first measuring means 12 and the measurement value measured by the second measuring means 28 exceeds a threshold value. This allows the water treatment device 1 to switch between nitrification treatment and denitrification treatment with high precision, even when water is repeatedly circulated in the water treatment device 1.

[0075] Furthermore, in the above embodiment, the water treatment device 1 has a second measuring means 28 that measures the water quality of the treated water after treatment in the biological treatment tank 20. The control means 50 controls the aeration time based on the number of times the difference between the measurement value measured by the first measuring means 12 and the measurement value measured by the second measuring means 28 is equal to or greater than a threshold value and the amount of wastewater supplied from the wastewater adjustment tank 10 to the biological treatment tank 20. This allows the water treatment device 1 to switch between nitrification treatment and denitrification treatment with higher precision, even when water is repeatedly circulated in the water treatment device 1.

[0076] In the above embodiment, the water treatment device 1 also includes a supplying means 80 that supplies a hydrogen donor to the biological treatment tank 20. The control means 50 sets the amount of hydrogen donor based on the number of times the difference between the measurement value measured by the first measuring means 12 and the measurement value measured by the second measuring means 12 exceeds a threshold value, and supplies the set amount of hydrogen donor when aeration is turned off. In this way, adding a hydrogen donor when aeration is turned off enables immediate switching from an aerobic environment to an anaerobic state. Furthermore, even when water is repeatedly circulated in the water treatment device 1, the amount of hydrogen donor appropriate for switching from nitrification to denitrification in the single-tank biological treatment tank 20 can be controlled based on the quality of the wastewater supplied to the wastewater adjustment tank 10.

[0077] In the above embodiment, the water treatment device 1 also includes a supplying means 80 for supplying a hydrogen donor to the biological treatment tank 20. The control means 50 sets the amount of hydrogen donor based on the number of times the difference between the measurement value measured by the first measuring means 12 and the measurement value measured by the second measuring means 28 exceeds a threshold value and the amount of wastewater supplied from the wastewater adjustment tank 10 to the biological treatment tank 20. The control means 50 then supplies the set amount of hydrogen donor when aeration is turned off. In this manner, adding the hydrogen donor when aeration is turned off enables immediate switching from an aerobic environment to an anaerobic state. Furthermore, even when water is repeatedly circulated in the water treatment device 1, the amount of hydrogen donor is set based on the amount of wastewater supplied from the wastewater adjustment tank 10 to the biological treatment tank 20. This allows for a more appropriate amount of hydrogen donor to be used in the single-tank biological treatment tank 20, thereby reducing the amount of hydrogen donor used.

[0078] <Modifications> In the above embodiment, the control unit 50 sets various parameters for the next series of steps based on the count values ​​counted during the previous series of steps. However, the period for measuring the count is not limited to the period during the previous series of steps. For example, as shown in FIG. 5, depending on the previous count value, the aeration cycle and the anoxic cycle may be 0 minutes. In such cases, the period for the series of steps may be shortened, and the wastewater may not be able to accumulate in the wastewater adjustment tank 10. Therefore, the following conditions may be set so that wastewater is not introduced from the wastewater adjustment tank 10 to the biological treatment tank 20 until the conditions are met: - A predetermined volume or more of wastewater is stored in the wastewater adjustment tank 10 - A predetermined volume or more of wastewater has been introduced into the wastewater adjustment tank 10

[0079] If the above conditions exist, for example, a water level meter, a flow meter, or the like is installed in the drainage adjustment tank 10.

[0080] The control unit 50 measures the count value until at least one of the above conditions is satisfied, for example, after the introduction step, nitrification step (0 minutes), denitrification step (0 minutes), and extraction step are completed. When the denitrification step (0 minutes) and extraction step are completed and at least one of the above conditions is satisfied, the control unit 50 sets parameters for the next series of steps based on the count value.

[0081] 8 is a flowchart showing another example of the operation of the control unit 50 when setting parameters relating to biological denitrification. In FIG. 8, the same processes as those in FIG. 2 are assigned the same numbers.

[0082] In step S31, the control unit 50 determines whether or not predetermined conditions related to the drainage of the drainage adjustment tank 10 are met. Specifically, for example, the control unit 50 determines whether or not conditions such as whether a predetermined volume or more of drainage is stored in the drainage adjustment tank 10 or whether a predetermined volume or more of drainage has been poured into the drainage adjustment tank 10 are met. If the conditions are not met, the control unit 50 shifts the process to step S32. If the conditions are met, the control unit 50 shifts the process to step S14.

[0083] In step S32, the control unit 50 acquires the EC value measured by the measuring instrument 12 and calculates a predetermined count value based on the acquired EC value. After counting the number of times, the control unit 50 shifts the process to step S31.

[0084] In the above embodiment, the biological denitrification parameters are set by referring to the count value based on the EC value. However, the setting of the biological denitrification parameters is not limited to referring only to the count value based on the EC value. For example, the control unit 50 may monitor the environment in the biological treatment tank 20 during the aeration cycle and change the aeration cycle based on the monitoring results. Furthermore, the control unit 50 may change the anaerobic cycle based on the changed aeration cycle.

[0085] Specifically, for example, the control unit 50 monitors the trends in DO, ORP, pH, T-N, NPOC, or at least any combination thereof, within the biological treatment tank 20 during the aeration cycle. If the nitrification treatment is expected to end earlier than the set aeration cycle, the control unit 50 shortens the aeration cycle. The control unit 50 updates the anaerobic cycle so that it is, for example, approximately one-third of the shortened aeration cycle. The control unit 50 also updates the amount of hydrogen donor added based on the shortened aeration cycle. In this way, by updating parameters based on the environment within the biological treatment tank 20, it is possible to reflect the environment within the biological treatment tank 20 in real time in the control of biological denitrification. This shortens the time required for biological denitrification in the biological treatment tank 20 and enables more efficient operation of the biological denitrification in the biological treatment tank 20.

[0086] The control unit 50 may also monitor the carbon dioxide concentration in the aeration cycle and update the aeration cycle so as to terminate the aeration cycle when it is estimated that the increase in the carbon dioxide concentration will stop. The control unit 50 updates the anaerobic cycle based on the updated aeration cycle. The control unit 50 also updates the amount of hydrogen donor added based on the updated aeration cycle. This shortens the time required for biological denitrification in the biological treatment tank 20 and enables more efficient operation of biological denitrification in the biological treatment tank 20.

[0087] The control unit 50 may also monitor the TN of the biological treatment tank 20 during the anaerobic cycle, and when the TN falls below a predetermined value, terminate the anaerobic cycle and proceed to the extraction process. This allows the biological denitrification process in the biological treatment tank 20 to be completed in a shorter time.

[0088] Furthermore, in the above embodiment, the supply unit 80 adds a hydrogen donor. However, the substance added by the supply unit 80 is not limited to a hydrogen donor. The supply unit 80 may also add organic matter. Organic matter is a compound supplied as a substrate for microorganisms in the biological treatment tank 20. If the recycling toilet 100 is not used for an extended period of time, the supply of wastewater containing organic matter to the biological treatment tank 20 may be disrupted, resulting in a lack of substrate for the microorganisms in the biological treatment tank 20 and their subsequent death. To prevent this, organic matter must be supplied to the biological treatment tank 20. In other words, by continuously supplying organic matter to the biological treatment tank 20, it is possible to continuously supply substrate to the facultative anaerobic bacteria present in the biological treatment tank 20. From the standpoint of ease of handling, the organic matter is preferably a fluid. Note that fluids are not limited to liquids and include substances in a gel state. Furthermore, a low-molecular-weight structure is preferable as the fluid, and for example, an organic compound with three or fewer carbon atoms is more preferable. This is because compounds with a low-molecular-weight structure with three or fewer carbon atoms are more biodegradable.

[0089] For example, the supply unit 80 may continuously and intermittently drip organic matter into the biological treatment tank 20 at multiple intervals, or may constantly drip organic matter into the biological treatment tank 20 continuously at a predetermined flow rate. The amount of organic matter supplied from the supply unit 80 may be set arbitrarily. For example, the monthly supply amount of organic matter may be set based on the amount of wastewater.

[0090] Furthermore, in the above embodiment, the biological treatment module 3 has been described as having the biological treatment tank 20, the agitator 23, the membrane filtration unit 25, the blower 26, the blower 27, and the supply unit 80. However, the configuration of the biological treatment module 3 is not limited to this. The biological treatment module 3 may have only one blower. That is, for example, the blower 27 may also serve as the blower 26. Furthermore, the blower 26 may also serve as the blower 27.

[0091] 9 is a block diagram showing the basic hardware configuration of a computer 90. The computer 90 includes at least a processor 91, a main storage device 92, an auxiliary storage device 93, and a communication IF (interface) 99. These components are electrically connected to one another by a bus.

[0092] The processor 91 is hardware for executing an instruction set written in a program, and is composed of an arithmetic unit, registers, peripheral circuits, and the like.

[0093] The main storage device 92 is for temporarily storing programs, data to be processed by the programs, etc. For example, it is a volatile memory such as a DRAM (Dynamic Random Access Memory).

[0094] The auxiliary storage device 93 is a storage device for saving data and programs, such as a flash memory, a hard disk drive (HDD), a magneto-optical disk, a CD-ROM, a DVD-ROM, or a semiconductor memory.

[0095] The communication IF 99 is an interface for inputting and outputting signals for communicating with other computers via a network using a wired or wireless communication standard. The network is composed of the Internet, a LAN, various mobile communication systems constructed using wireless base stations, etc. For example, the network includes 3G, 4G, and 5G mobile communication systems, LTE (Long Term Evolution), and wireless networks (e.g., Wi-Fi (registered trademark)) that can connect to the Internet via a predetermined access point. In the case of a wireless connection, communication protocols include, for example, Z-Wave (registered trademark), ZigBee (registered trademark), and Bluetooth (registered trademark). In the case of a wired connection, the network also includes a network that is directly connected using a USB (Universal Serial Bus) cable, etc.

[0096] It should be noted that the computer 90 can be virtually realized by distributing all or part of each hardware configuration across multiple computers 90 and interconnecting them via a network. In this way, the concept of the computer 90 includes not only a computer 90 housed in a single housing or case, but also a virtualized computer system.

[0097] <Basic Functional Configuration of Computer 90> A description will be given of the functional configuration of the computer realized by the basic hardware configuration of the computer 90 shown in Fig. 9. The computer includes at least the functional units of a control unit, a storage unit, and a communication unit.

[0098] The functional units of the computer 90 can also be realized by distributing all or part of the functional units among multiple computers 90 interconnected via a network. The computer 90 is a concept that includes not only a single computer 90 but also a virtualized computer system.

[0099] The control unit is realized by the processor 91 reading various programs stored in the auxiliary storage device 93, expanding them in the main storage device 92, and executing processing in accordance with the programs. The control unit can realize functional units that perform various types of information processing depending on the type of program. In this way, the computer is realized as an information processing device that performs information processing.

[0100] The storage unit is realized by a main storage device 92 and an auxiliary storage device 93. The storage unit stores data, various programs, and various databases. Furthermore, the processor 91 can allocate a storage area corresponding to the storage unit in the main storage device 92 or the auxiliary storage device 93 in accordance with the programs. Furthermore, the control unit can cause the processor 91 to execute processes for adding, updating, and deleting data stored in the storage unit in accordance with the various programs.

[0101] The term "database" refers to a relational database, which manages data sets called tables in a tabular format structurally defined by rows and columns, by associating them with one another. In a database, a table is called a table, a column in a table, and a row in a table a record. In a relational database, relationships between tables can be set and associated. Typically, each table has a column set as a key to uniquely identify a record, but setting a key to a column is not required. The control unit can cause the processor 91 to add, delete, or update records in specific tables stored in the storage unit according to various programs.

[0102] The communication unit is realized by the communication IF 99. The communication unit realizes the function of communicating with other computers 90 via a network. The communication unit can receive information transmitted from other computers 90 and input the information to the control unit. The control unit can cause the processor 91 to execute information processing on the received information in accordance with various programs. Furthermore, the communication unit can transmit information output from the control unit to other computers 90.

[0103] The functions performed by the components described herein may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), CPUs (Central Processing Units), conventional circuits, and / or combinations thereof, programmed to perform the described functions. Processors include transistors and other circuits and are considered circuitry or processing circuitry. A processor may also be a programmed processor that executes a program stored in memory. In this specification, a circuit, unit, or means is hardware that is programmed to perform or executes the described functions. The hardware may be any hardware disclosed herein or any hardware known to be programmed to perform or execute the described functions. When the hardware is a processor, which is considered a type of circuitry, the circuit, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0104] Although several embodiments of the present disclosure have been described above, these embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and modifications are intended to be included in the scope of the inventions and their equivalents as defined in the claims, as well as in the scope and spirit of the inventions.

[0105] <Supplementary Notes> The matters described in the above embodiments are supplemented below. (Supplementary Note 1) A water treatment device comprising: a wastewater adjustment tank for storing wastewater; a first measurement means for measuring the water quality of wastewater flowing into the wastewater adjustment tank; a single-tank biological treatment tank that switches between nitrification and denitrification treatments on wastewater supplied from the wastewater adjustment tank by switching aeration on and off; and a control means for controlling the aeration time in the nitrification treatment based on the measurement results of the first measurement means. (Supplementary Note 2) The water treatment device described in (Supplementary Note 1), in which the control means controls the aeration time based on the number of times the measurement value measured by the first measurement means exceeds a threshold. (Supplementary Note 3) The water treatment device described in (Supplementary Note 1), in which the control means controls the aeration time based on the number of times the measurement value measured by the first measurement means exceeds a threshold and the amount of wastewater supplied from the wastewater adjustment tank to the biological treatment tank. (Appendix 4) The water treatment device according to (Appendix 2) or (Appendix 3), further comprising: a feeding means for feeding a hydrogen donor into the biological treatment tank, wherein the control means sets the amount of the hydrogen donor based on the number of times the measurement value measured by the first measurement means exceeds a threshold, and feeds the set amount of hydrogen donor while switching off aeration. (Appendix 5) The water treatment device according to (Appendix 2) or (Appendix 3), further comprising: a feeding means for feeding a hydrogen donor into the biological treatment tank, wherein the control means sets the amount of the hydrogen donor based on the number of times the measurement value measured by the first measurement means exceeds a threshold and the amount of wastewater supplied from the wastewater adjustment tank to the biological treatment tank, and feeds the set amount of hydrogen donor while switching off aeration. (Appendix 6) The water treatment device according to (Appendix 1), further comprising: a second measurement means for measuring the water quality of treated water after treatment in the biological treatment tank, wherein the control means controls the aeration time based on the number of times the difference between the measurement value measured by the first measurement means and the measurement value measured by the second measurement means exceeds a threshold. (Appendix 7) A water treatment device as described in (Appendix 1), which has a second measuring means for measuring the water quality of treated water after treatment in the biological treatment tank, and the control means controls the aeration time based on the number of times the difference between the measurement value measured by the first measuring means and the measurement value measured by the second measuring means is equal to or greater than a threshold value, and the amount of wastewater supplied from the wastewater adjustment tank to the biological treatment tank.(Appendix 8) A water treatment device according to (Appendix 6) or (Appendix 7), which is provided with a feeding means for feeding a hydrogen donor into the biological treatment tank, and the control means sets the amount of the hydrogen donor based on the number of times a difference between a measurement value measured by the first measuring means and a measurement value measured by the second measuring means is equal to or greater than a threshold, and feeds the set amount of hydrogen donor while switching off aeration. (Appendix 9) A water treatment device according to (Appendix 6) or (Appendix 7), which is provided with a feeding means for feeding a hydrogen donor into the biological treatment tank, and the control means sets the amount of the hydrogen donor based on the number of times a difference between a measurement value measured by the first measuring means and a measurement value measured by the second measuring means is equal to or greater than a threshold, and the amount of wastewater supplied from the wastewater adjustment tank to the biological treatment tank, and feeds the set amount of hydrogen donor while switching off aeration. (Supplementary Note 10) A method executed by a water treatment device having a processor, wherein the processor executes the following steps: acquiring measurement results of the water quality of wastewater flowing into a wastewater adjustment tank; setting an aeration time for nitrification treatment in a single-tank biological treatment tank that receives the wastewater from the wastewater adjustment tank and alternately performs nitrification treatment and denitrification treatment on the wastewater based on the measurement results; and switching aeration in the biological treatment tank on / off based on the set aeration time. (Supplementary Note 11) A system comprising: a wastewater adjustment tank that stores wastewater, a first measuring means that measures the water quality of the wastewater flowing into the wastewater adjustment tank, a single-tank biological treatment tank that alternately performs nitrification treatment and denitrification treatment on the wastewater supplied from the wastewater adjustment tank by switching aeration on / off, and control means that controls the aeration time for nitrification treatment based on the measurement results of the first measuring means. (Appendix 12) A program executed in a water treatment device having a processor, the program causing the processor to execute the steps of: acquiring measurement results of the water quality of wastewater flowing into a wastewater adjustment tank; setting the aeration time for nitrification treatment in a single-tank biological treatment tank into which wastewater is input from the wastewater adjustment tank and which alternates between nitrification treatment and denitrification treatment; and switching aeration in the biological treatment tank on / off based on the set aeration time.

[0106] DESCRIPTION OF SYMBOLS 1... Water treatment device 10... Wastewater adjustment tank 20... Biological treatment tank 30... Treated water storage tank 40... Ozone generator 50... Control unit 80... Supply unit 100... Circulating toilet

Claims

1. A water treatment device comprising: a wastewater adjustment tank for storing wastewater; a first measuring means for measuring the water quality of the wastewater flowing into the wastewater adjustment tank; a biological treatment tank capable of switching the treatment of the wastewater supplied from the wastewater adjustment tank by switching aeration on and off; and a control means for controlling the aeration time in the treatment based on the measurement results of the first measuring means.

2. The water treatment device according to claim 1, wherein the control means controls the aeration time based on the number of times the measurement value measured by the first measurement means exceeds a threshold value.

3. A water treatment device as described in claim 1, wherein the control means controls the aeration time based on the number of times the measurement value measured by the first measuring means exceeds a threshold value and the amount of wastewater supplied from the wastewater adjustment tank to the biological treatment tank.

4. A water treatment device as described in claim 2 or 3, further comprising an introduction means for introducing a hydrogen donor into the biological treatment tank, wherein the control means sets the amount of the hydrogen donor based on the number of times the measurement value measured by the first measurement means exceeds a threshold value, and introduces the set amount of hydrogen donor while switching off the aeration.

5. A water treatment device as described in claim 2 or 3, further comprising an introduction means for introducing a hydrogen donor into the biological treatment tank, wherein the control means sets the amount of the hydrogen donor based on the number of times the measurement value measured by the first measuring means is equal to or greater than a threshold value and the amount of wastewater supplied from the wastewater adjustment tank to the biological treatment tank, and introduces the set amount of hydrogen donor when the aeration is off.

6. A water treatment device as described in claim 1, further comprising a second measuring means for measuring the water quality of the treated water after treatment in the biological treatment tank, and wherein the control means controls the aeration time based on the number of times that the difference between the measurement value measured by the first measuring means and the measurement value measured by the second measuring means becomes equal to or greater than a threshold value.

7. A water treatment device as described in claim 1, further comprising a second measuring means for measuring the water quality of the treated water after treatment in the biological treatment tank, wherein the control means controls the aeration time based on the number of times the difference between the measurement value measured by the first measuring means and the measurement value measured by the second measuring means is equal to or greater than a threshold value and on the amount of wastewater supplied from the wastewater adjustment tank to the biological treatment tank.

8. A water treatment device as described in claim 6 or 7, further comprising an introduction means for introducing a hydrogen donor into the biological treatment tank, wherein the control means sets the amount of the hydrogen donor based on the number of times that the difference between the measurement value measured by the first measurement means and the measurement value measured by the second measurement means becomes equal to or greater than a threshold value, and introduces the set amount of hydrogen donor when the aeration is off.

9. A water treatment device as described in claim 6 or 7, further comprising an introduction means for introducing a hydrogen donor into the biological treatment tank, wherein the control means sets the amount of the hydrogen donor based on the number of times that the difference between the measurement value measured by the first measuring means and the measurement value measured by the second measuring means becomes equal to or greater than a threshold value and the amount of wastewater supplied from the wastewater adjustment tank to the biological treatment tank, and introduces the set amount of hydrogen donor while switching off the aeration.

10. A method executed by a water treatment device having a processor, the method comprising the steps of: acquiring measurement results of the water quality of wastewater flowing into a wastewater adjustment tank; setting the aeration time for the treatment in a biological treatment tank, where the wastewater is fed from the wastewater adjustment tank and treated, based on the measurement results; and switching aeration in the biological treatment tank on / off based on the set aeration time.

11. A system comprising: a wastewater adjustment tank for storing wastewater; a first measuring means for measuring the water quality of the wastewater flowing into the wastewater adjustment tank; a single-tank biological treatment tank for treating the wastewater supplied from the wastewater adjustment tank by switching aeration on and off; and a control means for controlling the aeration time in the treatment based on the measurement results of the first measuring means.

12. A program executed in a water treatment device having a processor, the program causing the processor to execute the following steps: acquiring measurement results of the water quality of wastewater flowing into a wastewater adjustment tank; setting the aeration time for the nitrification treatment in a biological treatment tank into which wastewater is input from the wastewater adjustment tank and which can switch between nitrification treatment and denitrification treatment, based on the measurement results; and switching aeration on and off in the biological treatment tank based on the set aeration time.

Images