Wastewater treatment control device and wastewater treatment control method

Abstract

The present invention provides a wastewater treatment control device and a wastewater treatment control method that can control the amount of oxygen-containing gas supplied to a biological reaction tank for biological treatment of wastewater at low cost and with high precision. [Solution] The wastewater treatment control device 10 includes an information acquisition unit 32 that acquires information on the volume and quality of wastewater, information on the quality of treated water, information on the quality of water in the biological reaction tank, and information on the amount of gas supplied; a gas supply setting value determination unit 33 that determines a gas supply amount setting value or a dissolved oxygen concentration setting value by inputting predicted values ​​of the volume and quality of wastewater, the current value of the water quality in the biological reaction tank 3, and the target value of the water quality of treated water into the activated sludge model M; and a parameter adjustment unit 34 that adjusts the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter so as to minimize the difference between the model output value of the water quality of treated water acquired using the activated sludge model M and the measured value of the water quality of treated water.

Description

[Technical Field]

[0001] This invention relates to a technique for controlling the amount of oxygen-containing gas supplied to a biological reaction tank that biologically treats wastewater. [Background technology]

[0002] Wastewater discharged from homes and factories is primarily treated using the activated sludge method at sewage treatment plants. Organic matter contained in the wastewater is biologically treated (oxidized and decomposed) by microorganisms in the activated sludge in a biological reaction tank. To maintain the treated water at the target water quality, the amount of oxygen-containing gas (hereinafter sometimes simply referred to as "gas") supplied to the biological reaction tank is sometimes controlled. The water quality of the treated water can be indicated by indicators such as the NH4-N concentration (ammonia nitrogen concentration), NO3-N concentration (nitrate nitrogen concentration), NO2-N concentration (nitrite nitrogen concentration), and NO3-N + NO2-N concentration of the treated water. Feedback control based on measured values ​​of the treated water quality is used as a method to control the amount of gas supplied.

[0003] However, with this method, if the quality of the wastewater flowing into the biological reaction tank fluctuates significantly in a short period of time, there may be a delay in the feedback control in response to the fluctuations in wastewater quality, making it impossible to maintain the treated water at the target quality. In addition, there is a problem in that the amount of gas supplied cannot be properly controlled when the measured concentration values ​​indicating the quality of the treated water become extremely low.

[0004] As a way to solve these problems, attempts have been made to control the amount of gas supplied to the biological reaction tank by inputting the measured volume and quality of wastewater flowing into the biological reaction tank, as well as the target water quality of the treated water, into an activated sludge model and obtaining the amount of gas that should be supplied to the biological reaction tank. As an activated sludge model, the activated sludge model (hereinafter referred to as "ASM") proposed by the International Water Association (IWA) is well known. ASM is a mathematical model for simulating the biological reaction process of the activated sludge method. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-229550 [Patent Document 2] Japanese Patent Publication No. 2017-109170 [Patent Document 3] Japanese Patent Publication No. 2021-26617 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, because ASM is a complex activated sludge model that includes many parameters related to the reaction process of the activated sludge method, the simulation load is high, and it requires a considerable amount of processing time when using a general-purpose computer (PC). Therefore, in order to properly control the gas supply rate using ASM, a high-capacity computer is required, which increases costs. On the other hand, if the number of parameters included in the activated sludge model is reduced in order to reduce the simulation load, it becomes impossible to control the gas supply rate accurately.

[0007] Therefore, the present invention provides a wastewater treatment control device and a wastewater treatment control method that can control the amount of oxygen-containing gas supplied to a biological reaction tank for biological treatment of wastewater at low cost and with high precision. [Means for solving the problem]

[0008] In one embodiment, an information acquisition unit acquires information regarding the volume and quality of wastewater flowing into a biological reaction tank for biological treatment of wastewater, information regarding the quality of treated water treated in the biological reaction tank, information regarding the water quality inside the biological reaction tank, and information regarding the amount of gas supplied to the biological reaction tank. A gas supply unit inputs predicted values ​​for the volume and quality of wastewater, current values ​​for the water quality inside the biological reaction tank, and target values ​​for the water quality of the treated water into an activated sludge model to determine a set value for the amount of gas supplied to the biological reaction tank or a set value for the dissolved oxygen concentration inside the biological reaction tank. A wastewater treatment control device is provided, which includes a constant value determination unit and a parameter adjustment unit that inputs the measured values ​​of the wastewater volume and water quality obtained within the measurement time, and the measured values ​​of the gas supply amount obtained within the measurement time, into the activated sludge model to obtain a model output value of the treated water quality within the measurement time, and adjusts the organic matter oxidation reaction rate parameter and nitrification reaction rate parameter included in the activated sludge model so as to minimize the difference between the model output value of the treated water quality and the measured values ​​of the treated water quality obtained within the measurement time.

[0009] In one embodiment, the information acquisition unit is configured to acquire the current value of the water quality in the biological reaction tank by inputting the measured values ​​of the wastewater volume and water quality, and the measured value of the gas supply volume, into the activated sludge model. In one embodiment, the wastewater treatment control device further includes an operation control unit that controls the operation of an aeration device that supplies the gas to the biological reaction tank based on the set value of the air supply amount or the set value of the dissolved oxygen concentration. In one embodiment, the parameter adjustment unit is configured to issue an alarm when the difference between the model output value of the treated water quality and the measured value of the treated water quality exceeds a predetermined threshold, or when the adjusted parameter value of the organic matter oxidation reaction rate parameter or the nitrification reaction rate parameter is outside a predetermined tolerance range. In one embodiment, the air supply setting value determination unit is configured to determine a predetermined amount of gas supplied or a predetermined dissolved oxygen concentration in the biological reaction vessel to the air supply amount setting value or the dissolved oxygen concentration setting value when the alarm is issued by the parameter adjustment unit.

[0010] In one embodiment, the wastewater treatment control device further includes a parameter transition graph display unit that creates a parameter transition graph representing the temporal changes of the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter, and displays the parameter transition graph on a display screen. In one embodiment, the wastewater treatment control device further includes a treated water trend graph display unit that inputs measured values ​​of the wastewater volume and water quality, predicted values ​​of the wastewater volume and water quality, measured values ​​of the gas supply volume, and predicted values ​​of the gas supply volume into the activated sludge model to obtain a model output value of the treated water quality, creates a treated water trend graph that shows the temporal changes in the model output value of the treated water quality and the measured values ​​of the treated water quality, and displays the treated water trend graph on a display screen. In one embodiment, the wastewater treatment control device further includes a dual-axis control graph display unit that creates a dual-axis control graph representing the relationship between the measured value of the water quality of the treated water and the measured value of the amount of gas supplied, and displays the dual-axis control graph on a display screen. In one embodiment, the wastewater treatment control device inputs the measured values ​​of the wastewater volume and water quality, the predicted values ​​of the wastewater volume and water quality, the measured value of the gas supply volume, and the predicted value of the gas supply volume into the activated sludge model to obtain a model output value of the treated water quality, creates a two-axis control graph representing the relationship between the model output value of the treated water quality and the predicted value of the gas supply volume, and further includes a two-axis control graph display unit that displays the two-axis control graph on a display screen.

[0011] In one embodiment, the wastewater treatment control device further includes an operation result estimation unit that estimates multiple operation results, including the water quality of the treated water and the power consumption for the biological treatment, when the wastewater is biologically treated by the biological reaction tank in a plurality of operation patterns, and an operation pattern selection unit that selects one operation pattern from the plurality of operation patterns based on the plurality of operation results. In one embodiment, the operation result estimation unit is configured to estimate the water quality of the treated water in the plurality of operation patterns by inputting the conditions of the amount and quality of the wastewater sent to the biological reaction tank in the plurality of operation patterns, and the amount of gas supplied in the plurality of operation patterns, into the activated sludge model. In one embodiment, the operation result estimation unit is configured to estimate the power consumption in the plurality of operation patterns by inputting the amount and quality of the wastewater sent to the biological reaction tank in the plurality of operation patterns, and the amount of gas supplied in the plurality of operation patterns, into the activated sludge model. In one embodiment, the power consumption included in the plurality of operating results includes the power consumption of the wastewater pump that sends the wastewater to the biological reaction tank and the power consumption of the aeration device.

[0012] In one embodiment, an information acquisition step is performed to acquire information regarding the volume and quality of wastewater flowing into a biological reaction tank for biological treatment of wastewater, information regarding the quality of treated water treated in the biological reaction tank, information regarding the water quality inside the biological reaction tank, and information regarding the amount of gas supplied to the biological reaction tank. The measured values ​​of the volume and quality of the wastewater obtained within the measurement time, and the measured values ​​of the amount of gas supplied within the measurement time are input into an activated sludge model to obtain a model output value of the water quality of the treated water within the measurement time. A wastewater treatment control method is provided, which includes a parameter adjustment step of adjusting the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter included in the activated sludge model so as to minimize the difference between the value and the measured value of the treated water quality obtained within the measurement time, and a gas supply setting value determination step of determining the gas supply amount setting value or the dissolved oxygen concentration setting value in the biological reaction tank by inputting the predicted values ​​of the wastewater volume and water quality, the current value of the water quality in the biological reaction tank, and the target value of the treated water quality into the activated sludge model.

[0013] In one embodiment, the information acquisition step includes inputting the measured values ​​of the wastewater volume and water quality, and the measured values ​​of the gas supply volume, into the activated sludge model to obtain the current value of the water quality in the biological reaction tank. In one embodiment, the wastewater treatment control method further includes a device control step that controls the operation of an aeration device that supplies the gas to the biological reaction tank based on the set value of the air supply amount or the set value of the dissolved oxygen concentration. In one embodiment, the parameter adjustment step includes issuing an alarm when the difference between the model output value of the treated water quality and the measured value of the treated water quality exceeds a predetermined threshold, or when the adjusted parameter value of the organic matter oxidation reaction rate parameter or the nitrification reaction rate parameter is outside a predetermined tolerance range. In one aspect, the air supply set value determination step includes determining the predetermined air supply amount of the gas or the predetermined dissolved oxygen concentration in the biological reaction tank as the air supply amount set value or the dissolved oxygen concentration set value when the alarm is issued in the parameter adjustment step.

[0014] In one aspect, the wastewater treatment control method further includes a parameter transition graph display step of creating a parameter transition graph representing the temporal change of the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter and displaying the parameter transition graph on a display screen. In one aspect, the wastewater treatment control method inputs the measured values of the water volume and quality of the wastewater, the predicted values of the water volume and quality of the wastewater, the measured value of the air supply amount of the gas, and the predicted value of the air supply amount of the gas into the activated sludge model to obtain a model output value of the water quality of the treated water, creates a treated water transition graph representing the temporal change of the model output value of the water quality of the treated water and the measured value of the water quality of the treated water, and further includes a treated water transition graph display step of displaying the treated water transition graph on a display screen. In one aspect, the wastewater treatment control method further includes a biaxial control graph display step of creating a biaxial control graph representing the relationship between the measured value of the water quality of the treated water and the measured value of the air supply amount of the gas and displaying the biaxial control graph on a display screen. In one aspect, the wastewater treatment control method inputs the measured values of the water volume and quality of the wastewater, the predicted values of the water volume and quality of the wastewater, the measured value of the air supply amount of the gas, and the predicted value of the air supply amount of the gas into the activated sludge model to obtain a model output value of the water quality of the treated water, creates a biaxial control graph representing the relationship between the model output value of the water quality of the treated water and the predicted value of the air supply amount of the gas, and further includes a biaxial control graph display step of displaying the biaxial control graph on a display screen.

[0015] In one embodiment, the wastewater treatment control method further includes an operation result estimation step of estimating multiple operation results, including the water quality of the treated water and the power consumption required for the biological treatment, when the wastewater is biologically treated by the biological reaction tank in a plurality of operation patterns, and an operation pattern selection step of selecting one operation pattern from the plurality of operation patterns based on the plurality of operation results. In one embodiment, the water quality of the treated water when the wastewater is biologically treated by the biological reactor in the plurality of operating patterns is estimated by inputting the amount and quality conditions of the wastewater sent to the biological reactor in the plurality of operating patterns, and the amount of gas supplied in the plurality of operating patterns, into the activated sludge model, thereby estimating the water quality of the treated water in the plurality of operating patterns. In one embodiment, the water quality of the treated water when the wastewater is biologically treated by the biological reactor in the plurality of operating patterns is estimated by inputting the amount and quality conditions of the wastewater sent to the biological reactor in the plurality of operating patterns, and the amount of gas supplied in the plurality of operating patterns, into the activated sludge model, thereby estimating the power consumption in the plurality of operating patterns. In one embodiment, the power consumption included in the plurality of operating results includes the power consumption of the wastewater pump that sends the wastewater to the biological reaction tank and the power consumption of the aeration device. [Effects of the Invention]

[0016] The accuracy of the activated sludge model can be improved by adjusting the organic matter oxidation reaction rate parameters and nitrification reaction rate parameters included in the activated sludge model so that the difference between the model output values ​​of treated water quality obtained using the activated sludge model and the measured values ​​of treated water quality is minimized. Therefore, even when the number of parameters included in the activated sludge model is reduced to lower the processing load of the simulation, the amount of gas supplied can be controlled accurately. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram showing one embodiment of a wastewater treatment system and a wastewater treatment control device. [Figure 2] This is a block diagram showing one embodiment of a wastewater treatment control device. [Figure 3] This figure shows an example of a parameter transition graph displayed on the screen. [Figure 4] This figure shows an example of a treated water trend graph displayed on the screen. [Figure 5] This figure shows an example of a treated water trend graph displayed on the screen. [Figure 6] This figure shows an example of a two-axis management graph displayed on the screen. [Figure 7] This is a flowchart illustrating one embodiment of a wastewater treatment control method. [Figure 8] This is a block diagram showing another embodiment of a wastewater treatment control device. [Modes for carrying out the invention]

[0018] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic diagram showing one embodiment of a wastewater treatment system 1 and a wastewater treatment control device 10. As shown in Figure 1, the wastewater treatment system 1 includes a biological reaction tank 3 for biological treatment of wastewater (water to be treated), an aeration device 5 for supplying gas to the biological reaction tank 3, and a wastewater pump 8 for sending wastewater to the biological reaction tank 3. The wastewater treatment system 1 is connected to the wastewater treatment control device 10, and the operation of the wastewater treatment system 1 is controlled by the wastewater treatment control device 10.

[0019] Examples of wastewater treated by wastewater treatment system 1 include human waste, sewage, leachate from garbage, and organic wastewater discharged from various manufacturing processes, beverage and food processing processes, and restaurant kitchens. The wastewater contains suspended solids (SS), biochemical oxygen demand (BOD), ammonia nitrogen, organic nitrogen, and total nitrogen.

[0020] The wastewater pump 8 is located upstream of the biological reaction tank 3 and is configured to send wastewater to the biological reaction tank 3. In this embodiment, the wastewater pump 8 is configured to send wastewater from the inlet channel 60 into which the wastewater flows to the biological reaction tank 3. In one embodiment, the wastewater sent to the biological reaction tank 3 may be wastewater that has undergone treatment in a primary sedimentation tank (not shown). By sedimenting the wastewater in the primary sedimentation tank, the load on the biological treatment in the biological reaction tank 3 can be reduced. In this case, the wastewater pump 8 is located upstream of the primary sedimentation tank and sends wastewater from the inlet channel 60 to the primary sedimentation tank. The wastewater treated in the primary sedimentation tank flows into the biological reaction tank 3.

[0021] The biological reaction tank 3 is configured to biologically treat organic matter in wastewater using an activated sludge process. The aeration device 5 comprises an aeration member 12 located at the bottom of the biological reaction tank 3, a blower 15 that supplies gas to the aeration member 12, and an air supply control valve 16 that adjusts the amount of gas supplied. The aeration device 5 is configured to supply oxygen-containing gas (e.g., air) from the aeration member 12 into the biological reaction tank 3 by the operation of the blower 15 and the air supply control valve 16. In this specification, oxygen-containing gas may be simply referred to as "gas".

[0022] Wastewater contains ammonia nitrogen (NH4 + ) is included. In addition, some of the organic nitrogen compounds contained in wastewater are converted into ammonia nitrogen (NH4) by organisms in activated sludge. + It is broken down into nitrite ions (NO2) by nitrifying bacteria in activated sludge. - ) and nitrate ions (NO3 - It is oxidized. The treated water that has been biologically treated in biological reaction tank 3 flows into the next treatment facility (for example, the final sedimentation tank).

[0023] The wastewater treatment system 1 further includes an operation control device 30 that controls the operation of the aeration device 5 and the wastewater pump 8 of the wastewater treatment system 1. The operation control device 30 is configured to control the operation of the aeration device 5 according to a command value input based on the air supply amount setting value or DO concentration setting value determined by the air supply setting value determination unit 33, which will be described later. Specifically, the operation control device 30 controls the operation of the blower 15 and the air supply amount control valve 16 of the aeration device 5 according to a command value input based on the air supply amount setting value determined by the air supply setting value determination unit 33, and supplies gas from the diffuser member 12 into the biological reaction tank 3 at the set air supply amount. Alternatively, the operation control device 30 controls the operation of the blower 15 and the air supply amount control valve 16 of the aeration device 5 according to a command value input based on the DO concentration setting value determined by the air supply setting value determination unit 33, while monitoring the DO concentration in the biological reaction tank 3 measured by the DO meter 25, and supplies gas from the diffuser member 12 into the biological reaction tank 3 at the set air supply amount.

[0024] The operation control device 30 is configured to control the operation of the wastewater pump 8. Specifically, the operation control device 30 controls the operation of the wastewater pump 8 based on the water level of the inlet channel 60 or the fluid supply setting value. In one embodiment, a water level adjustment gate (not shown) is provided downstream of the inlet channel 60, and the water level of the inlet channel 60 is the water level on the outlet side of the water level adjustment gate. The fluid supply setting value may be a predetermined value, or it may be the fluid supply setting value of the wastewater pump 8 included in the operation pattern selected by the operation pattern selection unit 39, which will be described later.

[0025] The operation control device 30 comprises at least one computer. The operation control device 30 comprises a storage device 30a in which a program is stored, and an arithmetic unit 30b that performs calculations according to the instructions contained in the program. The storage device 30a comprises a main memory such as random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or solid state drive (SSD). Examples of arithmetic units 30b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the operation control device 30 is not limited to these examples.

[0026] The wastewater treatment system 1 further includes a wastewater flow meter 21 for measuring the amount (flow rate) of wastewater flowing into the biological reaction tank 3, and a wastewater concentration meter 23 for measuring the concentration that indicates the quality of the wastewater. The wastewater flow meter 21 and the wastewater concentration meter 23 are located on the upstream side of the biological reaction tank 3. In one embodiment, the wastewater flow meter 21 and the wastewater concentration meter 23 may be located on the wastewater inflow side within the biological reaction tank 3. In this embodiment, the wastewater flow meter 21 is configured to continuously measure the amount of wastewater at predetermined time intervals. The measured value of the amount of wastewater measured by the wastewater flow meter 21 is sent to the information acquisition unit 32 of the wastewater treatment control device 10, which will be described later.

[0027] In this embodiment, the wastewater concentration meter 23 is configured to continuously measure the concentration indicating the water quality of the wastewater at predetermined time intervals. Examples of the wastewater concentration meter 23 include an ammonia nitrogen concentration meter for measuring the NH4-N concentration (ammonia nitrogen concentration) of wastewater, and an organic matter concentration meter for measuring the organic matter concentration of wastewater. The wastewater concentration meter 23 may consist of either an ammonia nitrogen concentration meter or an organic matter concentration meter, or both. The measured values ​​of the concentrations indicating the water quality of the wastewater measured by the wastewater concentration meter 23 are sent to the information acquisition unit 32 of the wastewater treatment control device 10, which will be described later.

[0028] The wastewater treatment system 1 further includes a DO meter 25 that measures the DO concentration (dissolved oxygen concentration) in the biological reaction tank 3, which indicates the water quality of the treated water treated in the biological reaction tank 3, and a treated water concentration meter 27 that measures the concentration indicating the water quality of the treated water. The DO meter 25 is located on the treated water outlet side of the biological reaction tank 3. In this embodiment, the DO meter 25 is configured to continuously measure the DO concentration in the biological reaction tank 3 at predetermined time intervals. The measured value of the DO concentration in the biological reaction tank 3 measured by the DO meter 25 is sent to the information acquisition unit 32 of the wastewater treatment control device 10, which will be described later.

[0029] The treated water concentration meter 27 is located on the treated water outlet side of the biological reaction tank 3. In this embodiment, the treated water concentration meter 27 is configured to measure the concentration indicating the water quality of the treated water at predetermined time intervals. In one embodiment, the treated water concentration meter 27 may measure the concentration indicating the water quality of the treated water on a spot basis every few hours to several days. Examples of the treated water concentration meter 27 include an ammonia nitrogen concentration meter for measuring the NH4-N concentration (ammonia nitrogen concentration) of the treated water, a nitrate nitrogen concentration meter for measuring the NO3-N concentration (nitrate nitrogen concentration) of the treated water, a nitrite nitrogen concentration meter for measuring the NO2-N concentration (nitrite nitrogen concentration) of the treated water, and a NO3-N+NO2-N concentration meter for measuring the NO3-N+NO2-N concentration of the treated water. The treated water concentration meter 27 may be any one of the ammonia nitrogen concentration meter, nitrate nitrogen concentration meter, nitrite nitrogen concentration meter, and NO3-N+NO2-N concentration meter, or a combination thereof. The concentration values ​​indicating the water quality of the treated water, measured by the treated water concentration meter 27, are sent to the information acquisition unit 32 of the wastewater treatment control device 10, which will be described later.

[0030] The wastewater treatment system 1 further includes an air supply rate measuring device 29 for measuring the amount of gas supplied to the biological reaction tank 3. The air supply rate measuring device 29 is attached to the piping between the air supply rate control valve 16 and the aeration member 12 of the aeration device 5. In this embodiment, the air supply rate measuring device 29 is configured to continuously measure the amount of gas supplied to the biological reaction tank 3 at predetermined time intervals. The measured value of the amount of gas supplied to the biological reaction tank 3, as measured by the air supply rate measuring device 29, is sent to the information acquisition unit 32 of the wastewater treatment control device 10, which will be described later.

[0031] The wastewater treatment control device 10 includes at least one computer. The wastewater treatment control device 10 includes a storage device 10a that stores a program and an activated sludge model M, and an arithmetic unit 10b that performs calculations according to the instructions contained in the program. The storage device 10a includes a main memory such as random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or a solid-state drive (SSD). Examples of the arithmetic unit 10b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the wastewater treatment control device 10 is not limited to these examples.

[0032] The activated sludge model M stored in the memory device 10a of the wastewater treatment control device 10 is a mathematical model for simulating the reaction process of the activated sludge method in the biological reaction tank 3. The activated sludge model M of this embodiment is a simplified model in which some of the parameters included in the ASM (e.g., ASM2d) proposed by the International Water Association (IWA) are omitted or set to fixed values. For example, the activated sludge model M omits or sets to fixed values ​​parameters related to heterotrophic biological reactions without growth (hydrolysis and fermentation decomposition), parameters related to growth (denitrification) using fermentation products of heterotrophic metabolic processes as substrates under anaerobic conditions, parameters related to the autodecomposition of heterotrophic metabolic processes, parameters related to the autodecomposition of nitrifying bacterial metabolism, parameters related to phosphorus-accumulating biological metabolism, and parameters related to the chemical coagulation of phosphorus. By using the simplified activated sludge model M, the processing load of the simulation can be reduced.

[0033] The activated sludge model M of this embodiment includes fixed parameters whose parameter values ​​are set at a predetermined timing (for example, before operation of the wastewater treatment system 1) and not changed during operation of the wastewater treatment system 1, and movable parameters whose parameter values ​​are adjusted at predetermined time intervals during operation of the wastewater treatment system 1. In this embodiment, the fixed parameters are parameters related to the equipment conditions of the wastewater treatment system 1, etc., which do not change in any way during operation of the wastewater treatment system 1.

[0034] In this embodiment, the transport parameters are parameters relating to oxygen consumption using slow-degrading organic matter as a substrate under aerobic conditions for heterotrophic metabolism, parameters relating to oxygen consumption using easily degradable organic matter as a substrate under aerobic conditions for heterotrophic metabolism, parameters relating to the internal oxygen consumption of activated sludge (without substrate constraints) under aerobic conditions for heterotrophic metabolism, and denitrification (S) using easily degradable organic matter as a substrate under anaerobic conditions for heterotrophic metabolism. NO3 These are parameters related to consumption, and parameters related to oxygen consumption using ammonia as a substrate under aerobic conditions in nitrifying bacterial metabolism.

[0035] The parameters relating to oxygen consumption using slow-degrading organic matter as a substrate under aerobic conditions in heterotrophic metabolism included in the activated sludge model M of this embodiment correspond to the parameters relating to growth using fermentable organic matter as a substrate under aerobic conditions in the conventional ASM for heterotrophic metabolism. The parameters relating to oxygen consumption using easily degradable organic matter as a substrate under aerobic conditions in heterotrophic metabolism included in the activated sludge model M of this embodiment correspond to the parameters relating to growth using fermentable products as a substrate under aerobic conditions in the conventional ASM for heterotrophic metabolism. Denitrification (S) using easily degradable organic matter as a substrate under anaerobic conditions in heterotrophic metabolism included in the activated sludge model M of this embodiment NO3 The parameters related to consumption correspond to the parameters related to growth (denitrification) of heterotrophic organisms using fermentable organic matter as a substrate under anaerobic conditions in conventional ASM. The parameters related to oxygen consumption of nitrifying bacteria using ammonia as a substrate under aerobic conditions in the activated sludge model M of this embodiment correspond to the parameters related to growth of nitrifying bacteria under aerobic conditions in conventional ASM.

[0036] In this specification, among the transport parameters, the parameters relating to oxygen consumption using slow-degrading organic matter as a substrate under aerobic conditions for heterotrophic metabolism, the parameters relating to oxygen consumption using easily degradable organic matter as a substrate under aerobic conditions for heterotrophic metabolism, the parameters relating to the internal oxygen consumption of activated sludge (without substrate constraints) under aerobic conditions for heterotrophic metabolism, and the parameters relating to denitrification (S) using easily degradable organic matter as a substrate under anaerobic conditions for heterotrophic metabolism. NO3 The parameters related to oxygen consumption are collectively called "organic matter oxidation reaction rate parameters," and the parameters related to oxygen consumption using ammonia as a substrate under aerobic conditions in nitrifying bacterial metabolism are called "nitrification reaction rate parameters."

[0037] In adjusting the organic matter oxidation reaction rate parameters, parameters related to oxygen consumption using slow-degrading organic matter as a substrate under aerobic conditions in heterotrophic metabolism, parameters related to oxygen consumption using easily degradable organic matter as a substrate under aerobic conditions in heterotrophic metabolism, parameters related to the internal oxygen consumption of activated sludge (without substrate constraints) under aerobic conditions in heterotrophic metabolism, and denitrification (S) using easily degradable organic matter as a substrate under anaerobic conditions in heterotrophic metabolism. NO3 Each parameter related to consumption is adjusted based on a predetermined coefficient corresponding to that parameter.

[0038] The activated sludge model M can output (simulate) the water quality of treated water treated in the biological reaction tank 3 by inputting information on the volume and quality of wastewater and the amount of gas supplied to the biological reaction tank 3. Furthermore, the activated sludge model M can output (simulate) the amount of gas to be supplied to the biological reaction tank 3 by inputting information on the volume and quality of wastewater and target values ​​for the treated water quality.

[0039] As shown in Figure 1, the wastewater treatment control device 10 is connected to a display screen 50 such as a display and an input device 55 such as a keyboard and mouse.

[0040] Figure 2 is a block diagram showing one embodiment of the wastewater treatment control device 10. Figure 2 shows the components of the wastewater treatment control device 10 having various functions. As shown in Figure 2, the wastewater treatment control device 10 includes an information acquisition unit 32, an air supply setting value determination unit 33, and a parameter adjustment unit 34. The operation of the information acquisition unit 32, the air supply setting value determination unit 33, and the parameter adjustment unit 34 is performed by the arithmetic unit 10b executing calculations according to instructions contained in a program stored in the storage device 10a, which was described with reference to Figure 1.

[0041] The information acquisition unit 32 is configured to acquire information regarding the volume and quality of wastewater flowing into the biological reaction tank 3. The information regarding the volume and quality of wastewater includes measured and predicted values ​​of the volume and quality of wastewater. In this embodiment, the measured values ​​of the volume and quality of wastewater are the measured values ​​of the volume of wastewater measured by the wastewater flow meter 21 and the measured values ​​of the concentration indicating the quality of wastewater measured by the wastewater concentration meter 23. The information acquisition unit 32 acquires the measured values ​​of the volume of wastewater from the wastewater flow meter 21 and the measured values ​​of the concentration indicating the quality of wastewater from the wastewater concentration meter 23. In this embodiment, during the operation of the wastewater treatment system 1, the information acquisition unit 32 acquires the volume of wastewater measured continuously by the wastewater flow meter 21 at predetermined time intervals and the concentration indicating the quality of wastewater measured continuously by the wastewater flow meter 21 at predetermined time intervals.

[0042] In one embodiment, instead of obtaining measured values ​​of wastewater volume from the wastewater flow meter 21, the information acquisition unit 32 may calculate a calculated value of wastewater volume and acquire this calculated value as the measured value of wastewater volume. Specifically, the information acquisition unit 32 may be configured to calculate a calculated value of wastewater volume obtained by adding the increase in water volume due to rainfall to the base inflow amount determined based on the wastewater inflow pattern for each date and day of the week. The inflow pattern and calculation formula for calculating the calculated value of wastewater volume are stored in the storage device 10a. This makes it possible to reduce the costs associated with measuring wastewater volume (such as the installation cost and maintenance cost of the wastewater flow meter 21).

[0043] In one embodiment, instead of acquiring measured values ​​of the wastewater quality from the wastewater concentration meter 23, the information acquisition unit 32 may calculate a calculated value of the wastewater quality and acquire this calculated value as the measured value of the wastewater quality. Specifically, the information acquisition unit 32 may be configured to calculate a calculated value of the wastewater quality based on a base water quality determined based on the wastewater quality pattern for each date and day of the week, and a dilution coefficient associated with the increase in water volume due to rainfall. The water quality pattern and calculation formula for calculating the calculated value of the wastewater quality are stored in the storage device 10a. This makes it possible to reduce the costs associated with measuring the wastewater quality (such as the installation cost and maintenance cost of the wastewater concentration meter 23).

[0044] In this embodiment, the method for calculating the predicted values ​​of wastewater volume and water quality is the same as the method for calculating the calculated values ​​of wastewater volume and water quality described above. Specifically, the information acquisition unit 32 calculates a predicted value of wastewater volume by adding the increase in water volume due to rainfall to the base inflow amount determined based on the wastewater inflow pattern for each day of the week and date to be predicted. The information acquisition unit 32 also calculates a predicted value of wastewater water quality based on the dilution coefficient associated with the increase in water volume due to rainfall to the base water quality determined based on the wastewater water quality pattern for each day of the week and date to be predicted. However, the method for calculating the predicted values ​​of wastewater volume and water quality is not particularly limited to the calculation method described above.

[0045] The information acquisition unit 32 is configured to acquire information regarding the water quality of the treated water treated in the biological reaction tank 3. The information regarding the water quality of the treated water includes measured values ​​of the water quality of the treated water. In this embodiment, the measured values ​​of the water quality of the treated water are the measured value of the DO concentration in the biological reaction tank 3 measured by the DO meter 25, and the measured value of the concentration indicating the water quality of the treated water measured by the treated water concentration meter 27. The information acquisition unit 32 acquires the measured value of the DO concentration in the biological reaction tank 3 from the DO meter 25 and the measured value of the concentration indicating the water quality of the treated water from the treated water concentration meter 27. In this embodiment, during the operation of the wastewater treatment system 1, the information acquisition unit 32 acquires the DO concentration in the biological reaction tank 3 measured continuously by the DO meter 25 at predetermined time intervals, and the concentration indicating the water quality of the treated water measured continuously by the treated water concentration meter 27 at predetermined time intervals.

[0046] The information acquisition unit 32 is configured to acquire information regarding the water quality in the biological reaction tank 3. The information regarding the water quality in the biological reaction tank 3 includes the current value of the water quality in the biological reaction tank 3. The water quality in the biological reaction tank 3 differs from the water quality of the treated water (DO concentration, treated water concentration) treated in the biological reaction tank 3, and includes the water quality of the untreated (or in-treatment) wastewater and activated sludge in the biological reaction tank 3. Examples of water quality in the biological reaction tank 3 include the concentration of activated sludge in the biological reaction tank 3 (activated sludge suspended solids concentration), the NH4-N concentration (ammonia nitrogen concentration), NO3-N concentration (nitrate nitrogen concentration), organic matter concentration, and dissolved oxygen concentration (DO), which are concentrations indicating the water quality in the biological reaction tank 3. In this embodiment, the information acquisition unit 32 is configured to acquire the current value of the water quality in the biological reaction tank 3 by inputting the measured values ​​of the wastewater volume and water quality, and the measured value of the gas supply volume into the activated sludge model M.

[0047] The information acquisition unit 32 is configured to acquire information regarding the amount of gas supplied to the biological reaction tank 3. The information regarding the amount of gas supplied includes the measured value and the predicted value of the amount of gas supplied. In this embodiment, the measured value of the amount of gas supplied is the measured value of the amount of gas supplied to the biological reaction tank 3, as measured by the gas supply amount measuring instrument 29. The information acquisition unit 32 acquires the measured value of the amount of gas supplied to the biological reaction tank 3, as measured by the gas supply amount measuring instrument 29. In this embodiment, during the operation of the wastewater treatment system 1, the information acquisition unit 32 acquires the amount of gas supplied, which is continuously measured by the gas supply amount measuring instrument 29 at predetermined time intervals.

[0048] In one embodiment, instead of acquiring the measured value of the amount of gas supplied to the biological reaction tank 3 measured by the air supply amount measuring instrument 29, the information acquisition unit 32 may acquire the actual measured value of the amount of gas supplied from the operation record of the aeration device 5 by the operation control device 30. In another embodiment, the information acquisition unit 32 may acquire the input value of the amount of gas supplied, which is input by the operator via the input device 55 (see Figure 1), as the actual measured value of the amount of gas supplied.

[0049] The predicted gas supply rate may be a value predetermined by the operator, or it may be a value obtained by inputting the predicted wastewater volume and quality, the current water quality in the biological reaction tank 3, and the target water quality of the treated water into the activated sludge model M. Alternatively, the predicted gas supply rate may be a value obtained by inputting the predicted wastewater volume and quality, the current water quality in the biological reaction tank 3, and the target DO concentration (dissolved oxygen concentration setting) in the biological reaction tank 3 into the activated sludge model M.

[0050] The gas supply setting value determination unit 33 is configured to determine the gas supply amount setting value or the DO concentration setting value (dissolved oxygen concentration setting value) in the biological reaction tank 3 by inputting the predicted values ​​of wastewater volume and water quality acquired by the information acquisition unit 32, the current water quality value in the biological reaction tank 3 acquired by the information acquisition unit 32, and the target water quality value of the treated water into the activated sludge model M.

[0051] The target values ​​for treated water quality are the concentrations that indicate predetermined water quality in the treated water (one of the following: NH4-N concentration, NO3-N concentration, NO2-N concentration, and NO3-N+NO2-N concentration).

[0052] In this embodiment, a command value is input to the operation control device 30 by the operator based on the gas supply amount setting value determined by the gas supply setting value determination unit 33 or the DO concentration setting value in the biological reaction vessel 3.

[0053] In one embodiment, the wastewater treatment control device 10 is electrically connected to the operation control device 30, and the set value of the gas supply amount determined by the gas supply set value determination unit 33 or the set value of the DO concentration in the biological reaction tank 3 may be sent to the operation control device 30. In this case, the operation control device 30 may control the operation of the aeration device 5 based on the set value of the gas supply amount or the set value of the DO concentration in the biological reaction tank 3 sent from the wastewater treatment control device 10.

[0054] During operation of the wastewater treatment system 1, the parameter adjustment unit 34 is configured to adjust the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter, which are transfer parameters included in the activated sludge model M. First, the parameter adjustment unit 34 inputs the measured values ​​of wastewater volume and water quality obtained within the measurement time, and the measured values ​​of gas obtained within the measurement time, into the activated sludge model M to obtain the model output value of the treated water quality within the measurement time. The measurement time is a predetermined period (for example, several hours or several days) retrospectively from the present. The measured values ​​of wastewater volume and water quality obtained within the measurement time are the measured values ​​of wastewater volume measured by the wastewater flow meter 21 and the measured values ​​of the wastewater concentration indicating the water quality measured by the wastewater concentration meter 23, which are obtained by the information acquisition unit 32 within the measurement time.

[0055] The measured value of the gas supply amount obtained within the measurement time is the measured value of the gas supply amount to the biological reaction tank 3 obtained by the information acquisition unit 32 within the measurement time. In this embodiment, the model output value of the treated water quality is the DO concentration in the biological reaction tank 3 and the concentration indicating the water quality of the treated water (one of the following: NH4-N concentration, NO3-N concentration, NO2-N concentration, and NO3-N+NO2-N concentration).

[0056] Next, the parameter adjustment unit 34 adjusts the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter included in the activated sludge model M so as to minimize the difference between the model output value of the treated water quality during the measurement time and the measured value of the treated water quality obtained during the measurement time. The measured value of the treated water quality obtained during the measurement time is the DO concentration in the biological reaction tank 3 obtained by the information acquisition unit 32 during the measurement time, and the concentration indicating the water quality of the treated water obtained by the information acquisition unit 32 during the measurement time (one of NH4-N concentration, NO3-N concentration, NO2-N concentration, and NO3-N+NO2-N concentration).

[0057] The measurement points within the measurement period may be multiple points in time within a predetermined period (e.g., the past 6 hours) preceding the present, or they may be a single point in time. If there are multiple measurement points within the measurement period, the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter may be adjusted based on the cumulative or average value of the differences between multiple model output values ​​of the treated water quality corresponding to the multiple points in time and multiple measured values ​​of the treated water quality obtained at the same multiple points in time.

[0058] In one embodiment, the adjustment of the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter is performed as follows. The parameter adjustment unit 34 calculates the difference Ddo between the model output value of the DO concentration in the biological reaction tank 3 and the measured value of the DO concentration in the biological reaction tank 3, and calculates the difference Dnh4 between the model output value of the concentration indicating the quality of the treated water (for example, NH4-N concentration) and the measured value of the concentration indicating the quality of the treated water (for example, NH4-N concentration), and compares the difference Ddo and the difference Dnh4. The DO concentration in the biological reaction tank 3 mainly depends on the organic matter oxidation reaction rate parameter. The concentration indicating the quality of the treated water (any one of NH4-N concentration, NO3-N concentration, NO2-N concentration, and NO3-N+NO2-N concentration) mainly depends on the nitrification reaction rate parameter. Therefore, as a result of the comparison, when Ddo is larger than Dnh4, the organic matter oxidation reaction rate parameter is adjusted, and when Dnh4 is larger than Ddo, the nitrification reaction rate parameter is adjusted.

[0059] As a result of the comparison, when Ddo is larger than Dnh4, the organic matter oxidation reaction rate parameter is adjusted according to the following formula (1). Va n+1 =Va n +Ddo×Ka (1) Here, Va n+1 is the adjusted organic matter oxidation reaction rate parameter, Va n is the current organic matter oxidation reaction rate parameter, and Ka is a constant determined in advance to correct the degree of adjustment.

[0060] As a result of the comparison, when Dnh4 is larger than Ddo, the nitrification reaction rate parameter is adjusted according to the following formula (2). Vb n+1 =Vb n +Dnh4×Kb (2) Here, Vb n+1 is the adjusted nitrification reaction rate parameter, Vb n is the current nitrification reaction rate parameter, and Kb is a constant determined in advance to correct the degree of adjustment.

[0061] Subsequently, the parameter adjustment unit 34 adjusts the organic oxidation reaction rate parameter Va n+1 Or the adjusted nitrification reaction rate parameter Vb n+1 Using the activated sludge model M, which includes the model, the model output values ​​of the treated water quality (DO concentration in the biological reaction tank 3 and concentrations indicating the water quality of the treated water (e.g., NH4-N concentration)) are acquired again. The parameter adjustment unit 34 repeatedly adjusts the organic matter oxidation reaction rate parameter when Ddo is greater than Dnh4, and repeatedly adjusts the nitrification reaction rate parameter when Dnh4 is greater than Ddo, until the difference Ddo between the model output value of the DO concentration in the biological reaction tank 3 and the measured value of the DO concentration in the biological reaction tank 3 is less than or equal to a specified value, and the difference Dnh4 between the model output value of the concentration indicating the water quality of the treated water (e.g., NH4-N concentration) and the measured value of the concentration indicating the water quality of the treated water (e.g., NH4-N concentration) is less than or equal to a specified value. Through this operation, the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter approach optimal values.

[0062] After Ddo and Dnh4 fall below the specified values, the parameter adjustment unit 34 may further adjust the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter. Specifically, the parameter adjustment unit 34 uses multiple patterns of activated sludge models M, which consist of combinations of multiple candidate parameter values ​​that are near the adjusted organic matter oxidation reaction rate parameter and multiple candidate parameter values ​​that are near the adjusted nitrification reaction rate parameter, to obtain multiple patterns of model output values ​​for the treated water quality (DO concentration in the biological reaction tank 3 and concentrations indicating the water quality of the treated water (e.g., NH4-N concentration)).

[0063] The parameter adjustment unit 34 calculates multiple Ddo values, which are the difference between each of the multiple model output values ​​of the DO concentration in the biological reaction tank 3, obtained using multiple activated sludge model M patterns, and the measured value of the DO concentration in the biological reaction tank 3. It also calculates multiple Dnh4 values, which are the difference between each of the model output values ​​of the concentration indicating the water quality of the treated water (e.g., NH4-N concentration), obtained using multiple activated sludge model M patterns, and the measured value of the concentration indicating the water quality of the treated water (e.g., NH4-N concentration). The parameter adjustment unit 34 calculates combinations of the sum of the multiple Ddo and multiple Dnh4 values ​​and determines candidate parameter values ​​for the organic matter oxidation reaction rate parameter and candidate parameter values ​​for the nitrification reaction rate parameter included in the activated sludge model M pattern that minimizes the absolute value of the sum of the Ddo and Dnh4 values. The candidate parameter values ​​determined in this way are the optimized values ​​for the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter.

[0064] The parameter adjustment unit 34 adjusts the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter at predetermined time intervals (for example, every 15 minutes) while the wastewater treatment system 1 is in operation. This allows the accuracy of the activated sludge model M to be improved in response to the biological treatment capacity in the biological reaction tank 3, which changes moment by moment in response to fluctuations in the amount and quality of wastewater flowing into the biological reaction tank 3.

[0065] The parameter adjustment unit 34 is configured to issue an alarm when the difference between the model output value of the treated water quality and the measured value of the treated water quality exceeds a predetermined threshold, or when the adjusted parameter value of the organic matter oxidation reaction rate parameter or nitrification reaction rate parameter is outside a predetermined tolerance range. The predetermined tolerance range is, for example, a predetermined range of values ​​with the average value of the organic matter oxidation reaction rate parameter or nitrification reaction rate parameter within a specified period as the median. This predetermined range is determined based on a value Vr obtained by multiplying the standard deviation value of the organic matter oxidation reaction rate parameter or nitrification reaction rate parameter within a specified period by a predetermined coefficient. More specifically, the predetermined tolerance range is the range from the value obtained by subtracting the above value Vr from the average value of the organic matter oxidation reaction rate parameter or nitrification reaction rate parameter within a specified period to the value obtained by adding the above value Vr to the average value of the organic matter oxidation reaction rate parameter or nitrification reaction rate parameter. The specified period is a specified period retrospectively from the present, or a specified period in the past. Based on the alarm, the operator can check the parameter transition graph displayed on the display screen 50 (see Figure 1), which will be described later.

[0066] The air supply setting value determination unit 33 may be configured to determine a predetermined gas supply rate or a predetermined dissolved oxygen concentration in the biological reaction tank 3 to a predetermined gas supply rate setting value or a predetermined dissolved oxygen concentration setting value in the biological reaction tank 3 when an alarm is issued by the parameter adjustment unit 34. This predetermined gas supply rate or predetermined dissolved oxygen concentration in the biological reaction tank 3 may be calculated in correlation with the volume and quality of the wastewater. In one embodiment, the air supply setting value determination unit 33 may be configured to determine a predetermined gas supply rate or a predetermined dissolved oxygen concentration in the biological reaction tank 3 to a predetermined gas supply rate setting value or a predetermined dissolved oxygen concentration setting value in the biological reaction tank 3 based on a command input by an operator via the input device 55 (see Figure 1). This allows the aeration device 5 to operate within a normal range even if an unexpected abnormality occurs in the control of the gas supply rate using the activated sludge model M.

[0067] The wastewater treatment control device 10 further includes a parameter transition graph display unit 35. The parameter transition graph display unit 35 is configured to create a parameter transition graph that shows the temporal changes in the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter, and to display the parameter transition graph on the display screen 50 (see Figure 1). Figure 3 is a diagram showing an example of a parameter transition graph displayed on the display screen 50. In Figure 3, the change in the organic matter oxidation reaction rate parameter is represented by a solid line, and the change in the nitrification reaction rate parameter is represented by a dashed line. The parameter transition graph display unit 35 updates the parameter transition graph and displays it on the display screen 50 whenever the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter are adjusted by the parameter adjustment unit 34, for example. By viewing the parameter transition graph displayed on the display screen 50, the operator can understand whether or not there are any abnormalities in the changes in the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter.

[0068] The wastewater treatment control device 10 further includes a treated water trend graph display unit 36. The treated water trend graph display unit 36 ​​is configured to acquire model output values ​​of treated water quality by inputting the measured values ​​of wastewater volume and water quality, predicted values ​​of wastewater volume and water quality, measured values ​​of gas supply volume, and predicted values ​​of gas supply volume obtained from the information acquisition unit 32 into the activated sludge model M, create a treated water trend graph that shows the temporal changes in the model output values ​​of treated water quality and the measured values ​​of treated water quality, and display the treated water trend graph on the display screen 50. The model output values ​​of treated water quality may include model output values ​​of treated water quality after a predetermined time has elapsed from the present time.

[0069] Figures 4 and 5 show examples of treated water transition graphs displayed on the display screen 50. The graph in Figure 4 shows the temporal changes in the model output value of the DO concentration in the biological reaction tank 3 and the measured value of the DO concentration measured by the DO meter 25. The graph in Figure 5 shows the temporal changes in the model output value of the NH4-N concentration in the treated water and the measured value of the NH4-N concentration measured by the treated water concentration meter 27, as an example of a concentration indicating the water quality of the treated water. In Figures 4 and 5, the measured value is represented by a solid line, and the model output value is represented by a dashed line.

[0070] The treated water trend graph display unit 36 ​​updates the treated water trend graph and displays it on the display screen 50 whenever, for example, the information acquisition unit 32 acquires information on wastewater and treated water. By viewing the treated water trend graph displayed on the display screen 50, the operator can understand the wastewater treatment status in the wastewater treatment system 1.

[0071] The wastewater treatment control device 10 further includes a dual-axis management graph display unit 37. The dual-axis management graph display unit 37 is configured to create a dual-axis management graph that shows the relationship between the measured values ​​of the treated water quality obtained by the information acquisition unit 32 and the measured values ​​of the gas supply amount obtained by the information acquisition unit 32, and to display the dual-axis management graph on the display screen 50 (see Figure 1). Furthermore, the dual-axis management graph display unit 37 may also obtain a model output value of the treated water quality by inputting the measured values ​​of the wastewater volume and water quality, the predicted values ​​of the wastewater volume and water quality, the measured values ​​of the gas supply amount, and the predicted values ​​of the gas supply amount obtained by the information acquisition unit 32 into the activated sludge model M, and create a dual-axis management graph that shows the relationship between the model output value of the treated water quality and the predicted values ​​of the gas supply amount obtained by the information acquisition unit 32, and display the dual-axis management graph on the display screen.

[0072] Figure 6 shows an example of a dual-axis management graph displayed on the display screen 50. As shown in Figure 6, the dual-axis management graph shows the relationship between the measured values ​​of treated water quality and the measured values ​​of gas supply rate, separated by predetermined periods (monthly in this embodiment). The dual-axis management graph also shows the relationship between the model output value of treated water quality and the predicted value of gas supply rate. The dual-axis management graph display unit 37 updates the dual-axis management graph and displays it on the display screen 50 whenever, for example, wastewater and treated water information is acquired by the information acquisition unit 32. By viewing the dual-axis management graph displayed on the display screen 50, the operator can understand the wastewater treatment status and treatment predictions in the wastewater treatment system 1.

[0073] Figure 7 is a flowchart illustrating one embodiment of the wastewater treatment control method. The wastewater treatment control method in this embodiment is performed by the wastewater treatment control device 10 described above. In step 1, fixed parameters included in the activated sludge model M stored in the storage device 10a of the wastewater treatment control device 10 are set. In step 2, the information acquisition unit 32 of the wastewater treatment control device 10 acquires information regarding the amount and quality of wastewater flowing into the biological reaction tank 3, information regarding the quality of treated water treated in the biological reaction tank 3, information regarding the water quality inside the biological reaction tank 3, and information regarding the amount of gas supplied to the biological reaction tank 3 (information acquisition step). In this embodiment, during the operation of the wastewater treatment system 1, the information acquisition unit 32 acquires the amount of wastewater measured continuously by the wastewater flow meter 21 at predetermined time intervals as actual values ​​of the amount and quality of wastewater, the concentration indicating the quality of wastewater measured continuously by the wastewater concentration meter 23 at predetermined time intervals, and the DO concentration inside the biological reaction tank 3 measured continuously by the DO meter 25 at predetermined time intervals as actual values ​​of the amount and quality of wastewater, the concentration indicating the quality of treated water measured continuously by the treated water concentration meter 27 at predetermined time intervals as actual values ​​of the quality of treated water, and the amount of gas supplied measured continuously by the gas supply amount meter 29 at predetermined time intervals as actual values ​​of the amount of gas supplied. Furthermore, the information acquisition unit 32 acquires predicted values ​​for the volume and quality of wastewater, and predicted values ​​for the amount of gas supplied, while the wastewater treatment system 1 is in operation. In addition, the information acquisition unit 32 acquires the current value of the water quality in the biological reaction tank 3 by inputting the measured values ​​for the volume and quality of wastewater, and the amount of gas supplied, into the activated sludge model M while the wastewater treatment system 1 is in operation.

[0074] In step 3, the parameter adjustment unit 34 inputs the measured values ​​of wastewater volume and water quality obtained during the measurement period, and the measured value of the amount of gas supplied during the measurement period, into the activated sludge model M to obtain the model output value of the treated water quality during the measurement period. The unit then adjusts the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter included in the activated sludge model M so that the difference between the model output value of the treated water quality during the measurement period and the measured value of the treated water quality obtained during the measurement period is minimized (parameter adjustment step). The parameter adjustment step is performed at predetermined time intervals (for example, every 15 minutes) while the wastewater treatment system 1 is in operation.

[0075] The parameter adjustment unit 34 determines whether the difference between the model output value of the treated water quality and the measured value of the treated water quality exceeds a predetermined threshold, and whether the adjusted parameter values ​​of the organic matter oxidation reaction rate parameter or the nitrification reaction rate parameter are outside a predetermined tolerance range (step 4). If the parameter adjustment unit 34 determines that the difference between the model output value of the treated water quality and the measured value of the treated water quality does not exceed a predetermined threshold, or if the adjusted parameter values ​​of the organic matter oxidation reaction rate parameter or the nitrification reaction rate parameter are outside a predetermined tolerance range ("No" in step 4), the treatment flow proceeds to step 6.

[0076] The parameter adjustment unit 34 issues an alarm (step 5) when the difference between the model output value of the treated water quality and the measured value of the treated water quality exceeds a predetermined threshold, or when the adjusted parameter value of the organic matter oxidation reaction rate parameter or the nitrification reaction rate parameter is outside a predetermined tolerance range ("Yes" in step 4). Based on the alarm, the operator can check the parameter transition graph displayed on the display screen 50 (see Figure 1), as explained with reference to Figure 3.

[0077] If "No" is determined in step 4, in step 6, the air supply setting value determination unit 33 of the wastewater treatment control device 10 inputs the predicted values ​​of wastewater volume and water quality acquired by the information acquisition unit 32, the current value of water quality in the biological reaction tank 3 acquired by the information acquisition unit 32, and the target value of treated water quality into the activated sludge model M to determine the set value of the amount of gas supplied to the biological reaction tank 3 or the set value of the DO concentration (dissolved oxygen concentration set value) in the biological reaction tank 3 (air supply setting amount determination step). In this embodiment, the target value of the treated water quality is a concentration that indicates the predetermined water quality of the treated water (one of the following: NH4-N concentration, NO3-N concentration, NO2-N concentration, and NO3-N+NO2-N concentration).

[0078] If an alarm is issued in step 5, in step 6, the air supply setting value determination unit 33 may determine a predetermined gas supply rate or a predetermined dissolved oxygen concentration in the biological reaction vessel 3 to the gas supply rate setting value or the dissolved oxygen concentration setting value in the biological reaction vessel 3. In one embodiment, the air supply setting value determination unit 33 may determine a predetermined gas supply rate or a predetermined dissolved oxygen concentration in the biological reaction vessel 3 to the gas supply rate setting value or the dissolved oxygen concentration setting value in the biological reaction vessel 3 based on a command input by the operator via the input device 55 (see Figure 1). This predetermined gas supply rate or predetermined dissolved oxygen concentration in the biological reaction vessel 3 may be calculated in correlation with the volume and quality of the wastewater.

[0079] In step 7, the operator inputs a command value to the operation control device 30 based on the gas supply amount set value or the DO concentration set value in the biological reaction tank 3 determined by the gas supply set value determination unit 33. The operation control device 30 controls the operation of the aeration device 5 according to the input command value (device control process). After that, the process flow returns to step 2, and steps 2 to 7 are repeated.

[0080] In one embodiment, as shown in Figure 2, the wastewater treatment control device 10 may further include an operation result calculation unit 38 and an operation pattern selection unit 39. The operation result calculation unit 38 is configured to calculate multiple operation results, including the water quality of the treated water and the power consumption required for biological treatment, when wastewater is biologically treated by the biological reaction tank 3, for multiple operation patterns. The multiple operation patterns include operation patterns with different amounts of wastewater sent to the biological reaction tank 3 (i.e., the liquid supply setting value of the wastewater pump 8) and operation patterns with different amounts of gas supplied to the biological reaction tank 3.

[0081] The operation result estimation unit 38 estimates the water quality of treated water in multiple operation patterns by inputting the water volume and water quality conditions of the wastewater sent to the biological reaction tank 3 in multiple operation patterns, and the amount of gas supplied in multiple operation patterns, into the activated sludge model M. The operation result estimation unit 38 also estimates the power consumption required for biological treatment in multiple operation patterns by inputting the water volume and water quality conditions of the wastewater sent to the biological reaction tank 3 in multiple operation patterns, and the amount of gas supplied in multiple operation patterns, into the activated sludge model M.

[0082] The power consumption for biological treatment included in multiple operating results includes the power consumption of the wastewater pump 8 that sends wastewater to the biological reaction tank 3 and the power consumption of the aeration device 5 that supplies gas to the biological reaction tank 3. The operating result calculation unit 38 calculates the power consumption of the wastewater pump 8 based on the performance of the wastewater pump 8 (performance curve), facility conditions (location of the inlet 60, location of the biological reaction tank 3, piping configuration, etc.), and the water level of the inlet 60. The calculation formula for calculating the power consumption of the wastewater pump 8 is stored in the storage device 10a. The operating result calculation unit 38 calculates the power consumption of the aeration device 5 based on the previously acquired relationship between the amount of air supplied by the aeration device 5 and its power consumption. The calculation formula for calculating the power consumption of the aeration device 5 is stored in the storage device 10a.

[0083] In one embodiment, the operation result calculation unit 38 may be configured to calculate the water level of the inlet channel 60 as multiple operation results when wastewater is biologically treated by the biological reaction tank 3 in multiple operation patterns. The operation result calculation unit 38 calculates the water level of the inlet channel 60 based on the amount of wastewater sent to the biological reaction tank 3 included in the multiple operation patterns. The calculation formula for calculating the water level of the inlet channel 60 is stored in the storage device 10a.

[0084] The operation pattern selection unit 39 is configured to select one operation pattern from among multiple operation patterns based on multiple operation results calculated by the operation result calculation unit 38. In this embodiment, the operation pattern selection unit 39 is configured to display multiple operation results calculated by the operation result calculation unit 38 on the display screen 50. The operator selects one operation pattern from among multiple operation patterns based on the multiple operation results displayed on the display screen 50 and inputs it to the operation pattern selection unit 39 via the input device 55. For example, the operator determines which to prioritize based on the multiple operation results displayed on the display screen 50: the water quality of the treated water or the power consumption for biological treatment (in one embodiment, the water quality of the treated water, the power consumption for biological treatment, and the water level of the inflow channel 60), and selects one operation pattern.

[0085] The selected operating pattern is sent from the operating pattern selection unit 39 to the air supply setting value determination unit 33. The air supply setting value determination unit 33 determines the amount of gas supplied in the operating pattern sent from the operating pattern selection unit 39 to the gas supply amount setting value. In this embodiment, based on the gas supply amount setting value determined by the air supply setting value determination unit 33, a command value is input to the operation control device 30 by the operator. Alternatively, based on the liquid supply setting value of the wastewater pump 8 included in the operating pattern sent from the operating pattern selection unit 39, a command value is input to the operation control device 30 by the operator. This makes it possible to optimize the operation of the wastewater treatment system 1 based on the desired operating pattern.

[0086] The operation result calculation unit 38 calculates multiple operation results for multiple operation patterns (operation result calculation step), the operation pattern selection unit 39 selects an operation pattern (operation pattern selection step), and the air supply setting value determination unit 33 determines the air supply amount setting value based on the selected operation pattern. This can be applied to the air supply setting value determination step of step 6, as explained with reference to Figure 7.

[0087] Figure 8 is a block diagram showing another embodiment of the wastewater treatment control device 10. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figures 1 to 7, so redundant descriptions are omitted. In this embodiment, instead of the wastewater treatment system 1 having an operation control device 30, the wastewater treatment control device 10 has an operation control unit 40 that controls the operation of the aeration device 5 and the wastewater pump 8.

[0088] The operation control unit 40 controls the operation of the aeration device 5 based on the air supply amount setting value or DO concentration setting value determined by the air supply setting value determination unit 33. Specifically, the operation control unit 40 controls the operation of the blower 15 and air supply amount adjustment valve 16 of the aeration device 5 based on the air supply amount setting value determined by the air supply setting value determination unit 33 to supply gas from the diffuser member 12 into the biological reaction tank 3. Alternatively, the operation control unit 40 controls the operation of the blower 15 and air supply amount adjustment valve 16 of the aeration device 5 based on the DO concentration setting value determined by the air supply setting value determination unit 33, while monitoring the DO concentration in the biological reaction tank 3 measured by the DO meter 25, to supply gas from the diffuser member 12 into the biological reaction tank 3.

[0089] The operation control unit 40 is configured to control the operation of the wastewater pump 8. Specifically, the operation control unit 40 controls the operation of the wastewater pump 8 based on the water level of the inlet channel 60 or the fluid supply setting value. In one embodiment, a water level adjustment gate (not shown) is provided downstream of the inlet channel 60, and the water level of the inlet channel 60 is the water level on the outlet side of the water level adjustment gate. The fluid supply setting value may be a predetermined value, or it may be the fluid supply setting value of the wastewater pump 8 included in the operation pattern selected by the operation pattern selection unit 39.

[0090] In this embodiment, in step 7 described with reference to Figure 7, the operation control unit 40 controls the operation of the aeration device 5 based on the air supply set value or DO concentration set value determined by the air supply set value determination unit 33 (device control step).

[0091] In one embodiment, instead of acquiring the measured value of the amount of gas supplied to the biological reaction tank 3 measured by the air supply amount measuring instrument 29, the information acquisition unit 32 may acquire the actual measured value of the amount of gas supplied from the operation record of the aeration device 5 by the operation control unit 40.

[0092] The embodiments described above are intended to enable persons with ordinary skill in the art to implement the present invention. Various modifications of the above embodiments can be made naturally by those skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments as well. Therefore, the present invention is not limited to the embodiments described, but is to be interpreted in the broadest sense according to the technical idea defined by the claims. [Explanation of Symbols]

[0093] 1. Wastewater treatment system 3. Biological reaction vessel 5. Aeration device 8. Wastewater pump 10 Wastewater treatment control device 10a storage device 10b Arithmetic unit 12 Aeration member 15 Blower 16. Air volume control valve 21 Wastewater flow meter 23 Wastewater concentration meter 25 DO meter 27. Treated water concentration meter 29 Air supply measuring device 30. Operation control device 30a storage device 30b Arithmetic unit 32 Information Acquisition Department 33 Air supply set value determination unit 34 Parameter adjustment section 35 Parameter Transition Graph Display Section 36. Treated Water Trend Graph Display Section 37 Dual-axis management graph display section 38 Operation Result Estimation Department 39. Driving pattern selection section 40 Operation Control Unit 50 display screen 55 Input device 60 Inflow drain M Activated Sludge Model

Claims

1. An information acquisition unit acquires information regarding the volume and quality of wastewater flowing into a biological reaction tank for biological treatment of wastewater, information regarding the quality of treated water treated in the biological reaction tank, information regarding the water quality inside the biological reaction tank, and information regarding the amount of gas supplied to the biological reaction tank. A gas supply setting value determination unit determines the gas supply amount setting value or the dissolved oxygen concentration setting value in the biological reaction tank by inputting the predicted values ​​of the wastewater volume and water quality, the current water quality value in the biological reaction tank, and the target water quality value of the treated water into an activated sludge model, A wastewater treatment control device comprising a parameter adjustment unit that inputs the measured values ​​of the volume and quality of the wastewater obtained within the measurement period, and the measured value of the amount of gas supplied within the measurement period, into the activated sludge model to obtain a model output value of the water quality of the treated water within the measurement period, and adjusts the organic matter oxidation reaction rate parameter and nitrification reaction rate parameter included in the activated sludge model so as to minimize the difference between the model output value of the water quality of the treated water and the measured value of the water quality of the treated water obtained within the measurement period.

2. The wastewater treatment control device according to claim 1, wherein the information acquisition unit is configured to acquire the current value of the water quality in the biological reaction tank by inputting the measured values ​​of the wastewater volume and water quality, and the measured value of the gas supply volume, into the activated sludge model.

3. The wastewater treatment control device according to claim 1, further comprising an operation control unit that controls the operation of an aeration device that supplies the gas to the biological reaction tank based on the air supply volume setting value or the dissolved oxygen concentration setting value.

4. The wastewater treatment control device according to claim 1, wherein the parameter adjustment unit is configured to issue an alarm when the difference between the model output value of the treated water quality and the measured value of the treated water quality exceeds a predetermined threshold, or when the adjusted parameter value of the organic matter oxidation reaction rate parameter or the nitrification reaction rate parameter is outside a predetermined allowable range.

5. The wastewater treatment control device according to claim 4, wherein the air supply setting value determination unit is configured to determine a predetermined amount of gas supplied or a predetermined dissolved oxygen concentration in the biological reaction tank to the air supply amount setting value or the dissolved oxygen concentration setting value when the alarm is issued by the parameter adjustment unit.

6. The wastewater treatment control device according to claim 1, further comprising a parameter transition graph display unit that creates a parameter transition graph representing the time changes of the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter, and displays the parameter transition graph on a display screen.

7. The wastewater treatment control device according to claim 1, further comprising: an activated sludge model inputs the measured values ​​of the wastewater volume and water quality, the predicted values ​​of the wastewater volume and water quality, the measured value of the gas supply amount, and the predicted value of the gas supply amount to obtain a model output value of the treated water quality; a treated water transition graph display unit that creates a treated water transition graph representing the temporal changes in the model output value of the treated water quality and the measured value of the treated water quality; and a treated water transition graph display unit that displays the treated water transition graph on a display screen.

8. The wastewater treatment control device according to claim 1, further comprising a dual-axis control graph display unit that creates a dual-axis control graph representing the relationship between the measured values ​​of the treated water quality and the measured values ​​of the amount of gas supplied, and displays the dual-axis control graph on a display screen.

9. The wastewater treatment control device according to claim 1, further comprising a dual-axis control graph display unit that inputs the measured values ​​of the wastewater volume and water quality, the predicted values ​​of the wastewater volume and water quality, the measured value of the gas supply volume, and the predicted value of the gas supply volume into the activated sludge model to obtain a model output value of the treated water quality, creates a dual-axis control graph representing the relationship between the model output value of the treated water quality and the predicted value of the gas supply volume, and displays the dual-axis control graph on a display screen.

10. An operation result estimation unit that estimates multiple operation results, including the water quality of the treated water and the power consumption for the biological treatment, when the wastewater is biologically treated by the biological reaction tank in multiple operation patterns, The wastewater treatment control device according to claim 1, further comprising an operating pattern selection unit for selecting one operating pattern from among the plurality of operating patterns based on the plurality of operating results.

11. The wastewater treatment control device according to claim 10, wherein the operation result estimation unit is configured to estimate the water quality of the treated water in the plurality of operation patterns by inputting the conditions of the amount and quality of the wastewater sent to the biological reaction tank in the plurality of operation patterns and the amount of gas supplied in the plurality of operation patterns into the activated sludge model.

12. The wastewater treatment control device according to claim 10, wherein the operation result estimation unit is configured to estimate the power consumption in the plurality of operation patterns by inputting the amount and quality conditions of the wastewater sent to the biological reaction tank in the plurality of operation patterns and the amount of gas supplied in the plurality of operation patterns into the activated sludge model.

13. The wastewater treatment control device according to claim 10, wherein the power consumption included in the plurality of operating results includes the power consumption of the wastewater pump that sends the wastewater to the biological reaction tank and the power consumption of the aeration device.

14. An information acquisition step is provided to acquire information regarding the volume and quality of wastewater flowing into a biological reaction tank for biological treatment of wastewater, information regarding the quality of treated water treated in the biological reaction tank, information regarding the water quality inside the biological reaction tank, and information regarding the amount of gas supplied to the biological reaction tank. The parameter adjustment step involves inputting the measured values ​​of the wastewater volume and water quality obtained within the measurement period, and the measured values ​​of the gas supply volume obtained within the measurement period, into an activated sludge model to obtain a model output value of the treated water quality within the measurement period, and adjusting the organic matter oxidation reaction rate parameter and nitrification reaction rate parameter included in the activated sludge model so as to minimize the difference between the model output value of the treated water quality and the measured values ​​of the treated water quality obtained within the measurement period. A wastewater treatment control method comprising a step of determining a set value for the amount of gas supplied to the biological reaction tank or a set value for the dissolved oxygen concentration in the biological reaction tank, by inputting predicted values ​​for the amount and quality of the wastewater, the current value of the water quality in the biological reaction tank, and the target value of the water quality of the treated water into the activated sludge model.

15. The wastewater treatment control method according to claim 14, wherein the information acquisition step includes obtaining the current value of the water quality in the biological reaction tank by inputting the measured values ​​of the wastewater volume and water quality, and the measured value of the gas supply amount, into the activated sludge model.

16. The wastewater treatment control method according to claim 14, further comprising a device control step of controlling the operation of an aeration device that supplies the gas to the biological reaction tank based on the set value of the air supply amount or the set value of the dissolved oxygen concentration.

17. The wastewater treatment control method according to claim 14, wherein the parameter adjustment step includes issuing an alarm when the difference between the model output value of the treated water quality and the measured value of the treated water quality exceeds a predetermined threshold, or when the adjusted parameter value of the organic matter oxidation reaction rate parameter or the nitrification reaction rate parameter is outside a predetermined tolerance range.

18. The wastewater treatment control method according to claim 17, wherein the air supply setting value determination step includes determining a predetermined amount of gas supplied or a predetermined dissolved oxygen concentration in the biological reaction tank to the air supply amount setting value or the dissolved oxygen concentration setting value when the alarm is issued in the parameter adjustment step.

19. The wastewater treatment control method according to claim 14, further comprising the step of creating a parameter transition graph representing the temporal changes of the organic matter oxidation reaction rate parameter and the nitrification reaction rate parameter, and displaying the parameter transition graph on a display screen.

20. The wastewater treatment control method according to claim 14, further comprising the steps of inputting the measured values ​​of the wastewater volume and water quality, the predicted values ​​of the wastewater volume and water quality, the measured value of the gas supply amount, and the predicted value of the gas supply amount into the activated sludge model to obtain a model output value of the treated water quality, creating a treated water transition graph that shows the temporal changes of the model output value of the treated water quality and the measured value of the treated water quality, and displaying the treated water transition graph on a display screen.

21. The wastewater treatment control method according to claim 14, further comprising the step of creating a two-axis control graph that shows the relationship between the measured values ​​of the water quality of the treated water and the measured values ​​of the amount of gas supplied, and displaying the two-axis control graph on a display screen.

22. The wastewater treatment control method according to claim 14, further comprising the steps of inputting the measured values ​​of the wastewater volume and water quality, the predicted values ​​of the wastewater volume and water quality, the measured value of the gas supply volume, and the predicted value of the gas supply volume into the activated sludge model to obtain a model output value of the treated water quality, creating a two-axis control graph representing the relationship between the model output value of the treated water quality and the predicted value of the gas supply volume, and displaying the two-axis control graph on a display screen.

23. An operation result estimation step is performed to estimate multiple operation results, including the water quality of the treated water and the power consumption required for the biological treatment, when the wastewater is biologically treated by the biological reaction tank in multiple operation patterns. The wastewater treatment control method according to claim 14, further comprising a driving pattern selection step of selecting one driving pattern from among the plurality of driving patterns based on the plurality of driving results.

24. The wastewater treatment control method according to claim 23, wherein in the plurality of operating patterns, the water quality of the treated water when the wastewater is biologically treated by the biological reaction tank is estimated by inputting the amount and quality conditions of the wastewater sent to the biological reaction tank in the plurality of operating patterns and the amount of gas supplied in the plurality of operating patterns into the activated sludge model, thereby estimating the water quality of the treated water in the plurality of operating patterns.

25. The wastewater treatment control method according to claim 23, wherein in the plurality of operating patterns, the estimation of the water quality of the treated water when the wastewater is biologically treated by the biological reaction tank is performed by inputting the amount and quality conditions of the wastewater sent to the biological reaction tank in the plurality of operating patterns and the amount of gas supplied in the plurality of operating patterns into the activated sludge model to estimate the power consumption in the plurality of operating patterns.

26. The wastewater treatment control method according to claim 23, wherein the power consumption included in the plurality of operating results includes the power consumption of the wastewater pump that sends the wastewater to the biological reaction tank and the power consumption of the aeration device.

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