Dynamic monitoring system for sewage treatment

Abstract

The invention discloses a dynamic supervisory system for sewage treatment, belongs to the technical field of sewage treatment, and solves the problems that high-concentration saline water is obviously higher than domestic sewage in density and continuously accumulates at the bottom of an adjusting tank to form a density spring layer, so that vortex generated by a conventional stirrer can only disturb an upper-layer water body and cannot penetrate through a density interface; if the COD monitoring only depends on the surface sampling point, the COD monitoring is continuously displayed; the standard can be stably reached; and problems are solved. Comprising a differential pressure sensing array module, a multi-frequency impedance measurement module, an environment compensation module, a signal conditioning module, a main control processing module and an output execution module. The differential pressure sensing array module collects pressure data at different heights, the signal conditioning module processes signals, the multi-frequency impedance measurement module measures an impedance spectrum, the environment compensation module obtains parameters, and the main control processing module calculates gradients, inverts salinity distribution, judges density spring layer and surface COD standard reaching illusion and evaluates risk values. When the threshold value is exceeded, the stirrer is controlled to stir to prevent impact accidents of the biochemical pool.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a sewage treatment dynamic monitoring system. Background Art

[0002] Wastewater treatment involves the purification of wastewater using physical, chemical, and biological methods. Physical methods, such as sedimentation and filtration, can remove suspended matter and some impurities from wastewater. Chemical treatment uses coagulation and redox processes to induce chemical reactions of dissolved pollutants in wastewater, forming precipitates or removing gases. Biological treatment utilizes microorganisms to decompose organic pollutants. Treated wastewater, once it meets discharge standards, can be discharged or further treated for reuse, significantly contributing to the protection of the water environment and the recycling of water resources.

[0003] To ensure timely reflection and adjustment of sewage status, dynamic sewage supervision is required during the treatment process. Dynamic sewage treatment supervision utilizes modern information technology to monitor and manage the entire sewage treatment process in real time. Sensors and monitoring equipment installed in key locations within sewage treatment facilities collect real-time data on flow, water quality, and equipment operation. This data is then transmitted to a monitoring platform via the network. Through data analysis and processing, real-time control of sewage treatment conditions is achieved. In the event of data anomalies or equipment failures, early warnings are issued, enabling management personnel to respond quickly, ensuring stable operation of sewage treatment facilities and ensuring that treated water meets discharge standards, thereby improving sewage treatment efficiency and management.

[0004] Especially in the dynamic supervision of the regulating tank in the pretreatment stage of the sewage treatment plant, the high-salt wastewater discharged by chemical companies often has a chloride concentration exceeding 1500 mg / L and a salinity of more than 3%. This high-concentration salt water has a significantly higher density than domestic sewage, and continues to accumulate at the bottom of the regulating tank to form a density jump layer. As a result, the vortex generated by the conventional agitator can only disturb the upper water body and cannot penetrate the density interface. At this time, if only relying on the online COD analyzer monitoring at the surface sampling point, it will continue to show the illusion of "stable compliance", while the actual COD concentration at the bottom 1.5-2m deep has accumulated to >2000 mg / L due to the long-term retention of high-concentration organic salt water.

[0005] However, this hidden stratification risk is difficult to detect on a normal day until heavy rain comes. A large amount of rainwater rushes into the regulating pond, causing severe hydraulic disturbances. The density interface is instantly destroyed, and the high-load sewage accumulated at the bottom is suddenly released into the subsequent biochemical pond in a short period of time. The impact load can reach several times the design value, which directly causes the dissolved oxygen in the activated sludge system to drop sharply to below 0.2 mg / L, and the nitrifying bacteria are inactivated on a large scale. Microscopic examination shows a large number of filamentous bacteria outbreaks, which eventually leads to a long-lasting collapse of the biochemical system and serious excessive ammonia nitrogen in the effluent.

[0006] Therefore, it is necessary to identify this false impression in a timely manner to avoid the entire system from collapsing due to rainy days.

[0007] Therefore, a sewage treatment dynamic supervision system is proposed to solve or alleviate the above problems. Summary of the Invention

[0008] The purpose of the present invention is to solve the shortcomings of the existing technology and propose a dynamic monitoring system for sewage treatment.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions: A sewage treatment dynamic monitoring system includes a differential pressure sensor array module, a multi-frequency impedance measurement module, an environmental compensation module, a signal conditioning module, a main control processing module, and an output execution module; The output end of the differential pressure sensing array module is coupled to the input end of the signal conditioning module, and the output end of the signal conditioning module is coupled to the input end of the main control processing module. The differential pressure sensing array module collects vertical pressure data in the pool and transmits it; The impedance output terminal of the multi-frequency impedance measurement module is coupled to the input terminal of the main control processing module, and the multi-frequency impedance measurement module obtains the water body impedance spectrum and transmits it; The data output terminal of the environmental compensation module is coupled to the input terminal of the main control processing module, and the environmental compensation module monitors the water parameters in real time and transmits them; The control signal output terminal of the main control processing module is coupled to the driving input terminal of the output execution module. The main control processing module performs density gradient calculation and risk decision-making and is hierarchically controlled by the output execution module.

[0010] Preferably, the differential pressure sensing array module includes three differential pressure sensors arranged at different water depths, three AD8220 instrumentation amplifiers, and three groups of RC filtering networks. The power connection ends of the three differential pressure sensors are all grounded, and the power connection ends of the three differential pressure sensors are all electrically connected. The output ends of the three differential pressure sensors are respectively connected to the input ends of each AD8220 instrumentation amplifier, and the output end of the AD8220 instrumentation amplifier is connected to the input end of the signal conditioning module through the RC filtering network.

[0011] Preferably, the signal conditioning module includes three INA333 instrumentation amplifiers, a PGA280 programmable gain amplifier, an ADAS3022 analog-to-digital converter, and an LTC6655 reference voltage source. The input ends of the three INA333 instrumentation amplifiers are respectively connected to the output ends of the three groups of RC filter networks in the differential pressure sensor array module, and the output ends of the three INA333 instrumentation amplifiers are all connected to the three-channel input ends of the PGA280 programmable gain amplifier. The output end of the PGA280 programmable gain amplifier is connected to the input end of the ADAS3022 analog-to-digital converter. The controlled end of the PGA280 programmable gain amplifier is connected to the control channel switching end of the main control processing module. The output end of the LTC6655 reference voltage source is connected to the reference voltage end of the ADAS3022 analog-to-digital converter. The clock end and data end of the ADAS3022 analog-to-digital converter are both coupled to the main control processing module.

[0012] Preferably, the multi-frequency impedance measurement module includes three AD9834 DDS chips, three OPA569 operational amplifiers, three sets of quadrupole conductivity cells, three AD630 lock-in amplifiers, and an ADS124S08 analog-to-digital converter. The two measuring electrodes of the three sets of quadrupole conductivity cells are disposed within the cell bodies and are located at the same level as the differential pressure sensors in the differential pressure sensor array module. The output of the AD9834 DDS chip is connected to the input of the OPA569 operational amplifier, which is connected to the current electrode of the quadrupole conductivity cell. The measuring electrode of the quadrupole conductivity cell is coupled to the input of the AD630 lock-in amplifier. The output of the AD9834 DDS chip is coupled to the reference input of the AD630 lock-in amplifier. The output of the AD630 lock-in amplifier is connected to the input channel of the ADS124S08 analog-to-digital converter. The output of the ADS124S08 analog-to-digital converter is coupled to the main control processing module.

[0013] Preferably, the environmental compensation module includes a PT1000 temperature sensor, an OPA188 differential amplifier, and an MS5803-14BA pressure sensor. The PT1000 temperature sensor and the MS5803-14BA pressure sensor are both arranged at the middle depth of the pool body. The output end of the PT1000 temperature sensor is connected to the input end of the OPA188 differential amplifier, the output end of the OPA188 differential amplifier is connected to the ADS124S08 analog-to-digital converter in the multi-frequency impedance measurement module, the power terminal of the MS5803-14BA pressure sensor is connected to power, its ground terminal is grounded, and the output end of the MS5803-14BA pressure sensor is connected to the main control processing module.

[0014] Preferably, the main control processing module includes an STM32H743 controller, a DS3231 clock chip, and a FRAM memory. The clock end of the STM32H743 controller is coupled to the DS3231 clock chip, the input and output ends of the FRAM memory are coupled to the STM32H743 controller, and the data end of the STM32H743 controller is respectively coupled to the MS5803-14BA pressure sensor in the environmental compensation module, the ADAS3022 analog-to-digital converter and the PGA280 programmable gain amplifier in the signal conditioning module, and the ADS124S08 analog-to-digital converter in the multi-frequency impedance measurement module.

[0015] Preferably, the output execution module includes an RS485 interface, a host computer, a TLP281-4 optocoupler, a relay, a gantry crane, and a submersible mixer. The RS485 interface is coupled to the STM32H743 controller in the main control processing module, and the RS485 interface outputs data to the host computer. The input end of the TLP281-4 optocoupler is coupled to the STM32H743 controller in the main control processing module, and the output end of the TLP281-4 optocoupler is connected to the positive pole of the coil of the relay, the negative pole of the coil of the relay is grounded, the submersible mixer is electrically connected, and the contacts of the relay are connected in series to the power circuit of the submersible mixer.

[0016] Preferably, the main control processing module performs density gradient calculation and risk decision making, and the output execution module performs hierarchical control, which specifically includes the following steps: Preprocessing of differential pressure signal: performing quadratic polynomial correction on the original pressure value, with its coefficients stored in memory, and using temperature compensation coefficient of 0.00018 per degree Celsius to compensate the pressure value; After measuring impedance at three frequency points of 100 Hz, 1 000 Hz and 10 kHz, salinity inversion is performed by multiplying the cell constant by the ratio of the impedance modulus at 100 Hz to the impedance modulus at 10 kHz, and then multiplying by the real part of the impedance at 1 kHz, wherein the cell constant is stored in a memory; After measuring the water temperature and water depth insulation pressure values, the density difference is corrected using a pressure compensation coefficient of 2.1 times 10 to the power of negative fourth per kiloPascal. The density gradient is calculated as the bottom-top pressure difference multiplied by the reference water density of 998.2 kilograms per cubic meter, divided by the product of the acceleration of gravity of 9.80665 meters per second squared and the distance between the sensors of 2.0 meters; When the corrected density difference is between 2.0 and 5.0 kilograms per cubic meter, the risk value is 0.5 times the density difference minus 2 plus 0.3 times the normalized salinity value; when the corrected density difference is greater than or equal to 5.0 kilograms per cubic meter, the risk value is the density difference plus 0.5 times the normalized salinity value; When the risk value is between 3.0 and 5.0, the gantry crane in the control output execution module drives the submersible mixer to sink to the middle layer of the pool for mixing. When the risk value is greater than or equal to 5.0, the gantry crane in the control output execution module drives the submersible mixer to sink to the bottom layer of the pool for mixing, and the upper computer in the output execution module outputs an alarm code.

[0017] Preferably, it also includes a power management module, which provides power to each module.

[0018] The present invention has the following beneficial effects: In the actual process of dynamic sewage monitoring, when high-salt wastewater is discharged, even if the density in the regulating tank is higher than that of domestic sewage and a density jump layer is formed at the bottom of the regulating tank, the differential pressure sensor array module synchronously collects pressure data at different levels in the regulating tank, specifically the shallow, middle and bottom layers. The signal conditioning module amplifies and digitizes the original signal. At the same time, the multi-frequency impedance measurement module measures the impedance spectrum of 100Hz / 1kHz / 10kHz frequency bands at the same depth. The environmental compensation module obtains water temperature and water depth pressure parameters. After the main control processing module receives all the data, it first calculates the vertical density gradient and then inverts the salinity distribution through the impedance frequency-amplitude ratio. For the problem of high-salt wastewater sinking to the bottom, when the deep density is detected, When the salinity difference is greater than the threshold and the bottom salinity is greater than the threshold, it is determined that there is a density jump layer. At this time, combined with the pressure-temperature cross-compensation correction data, if the surface salinity is less than the threshold and the bottom salinity is greater than the threshold, it is confirmed that the surface COD meets the standard illusion, and then the risk value is evaluated. When the risk value exceeds the threshold, the output execution module starts the graded control. When the risk value is between 3.0 and 5.0, the gantry crane in the control output execution module drives the submersible mixer to sink to the middle layer in the pool for stirring. When the risk value is greater than or equal to 5.0, the gantry crane in the control output execution module drives the submersible mixer to sink to the bottom layer in the pool for stirring. The upper computer in the output execution module outputs an alarm code to accurately identify the COD monitoring distortion caused by high salt density stratification, and effectively prevent biochemical pool impact accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a structural block diagram of the present invention.

[0021] In the figure, 1. Environmental compensation module; 2. Multi-frequency impedance measurement module; 3. Differential pressure sensor array module; 4. Signal conditioning module; 5. Main control processing module; 6. Output execution module; 7. Power management module. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0025] In the description of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use, or are the orientation or position relationship commonly understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] Furthermore, the terms “first,” “second,” “third,” etc., are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0028] A dynamic monitoring system for sewage treatment, such as Figure 1 As shown, it includes a differential pressure sensing array module 3, a multi-frequency impedance measurement module 2, an environmental compensation module 1, a signal conditioning module 4, a main control processing module 5, an output execution module 6, and a power management module 7. The power management module 7 provides power for each module. The output end of the differential pressure sensor array module 3 is coupled to the input end of the signal conditioning module 4, and the output end of the signal conditioning module 4 is coupled to the input end of the main control processing module 5. The differential pressure sensor array module 3 collects and transmits the vertical pressure data in the pool. The differential pressure sensor array module 3 includes three differential pressure sensors set at different water depths, three AD8220 instrument amplifiers, and three groups of RC filter networks. The power terminals of the three differential pressure sensors are all grounded, and the power terminals of the three differential pressure sensors are all powered. The output ends of the three differential pressure sensors are respectively connected to the input ends of each AD8220 instrument amplifier. The output end of the AD8220 instrument amplifier is connected to the input end of the signal conditioning module 4 through the RC filter network. The signal conditioning module 4 includes three INA333 instrument amplifiers, PGA280 programmable amplifiers, and a 10-bit CMOS chip. The input terminals of the three INA333 instrumentation amplifiers are respectively connected to the output terminals of the three groups of RC filter networks in the differential pressure sensor array module 3, the output terminals of the three INA333 instrumentation amplifiers are all connected to the three-channel input terminals of the PGA280 programmable gain amplifier, the output terminal of the PGA280 programmable gain amplifier is connected to the input terminal of the ADAS3022 analog-to-digital converter, the controlled terminal of the PGA280 programmable gain amplifier is connected to the control channel switching terminal of the main control processing module 5, the output terminal of the LTC6655 reference voltage source is connected to the reference voltage terminal of the ADAS3022 analog-to-digital converter, and the clock terminal and data terminal of the ADAS3022 analog-to-digital converter are both coupled to the main control processing module 5; When the depth of the regulating pool is 3m, three differential pressure sensors are set at depths of 0.5m / 1.5m / 2.5m, representing the shallow layer, middle layer, and bottom layer respectively.

[0029] The impedance output terminal of the multi-frequency impedance measurement module 2 is coupled to the input terminal of the main control processing module 5. The multi-frequency impedance measurement module 2 obtains and transmits the water body impedance spectrum. The multi-frequency impedance measurement module 2 includes three DDS chips AD9834, three OPA569 operational amplifiers, three sets of quadrupole conductivity cells, three AD630 lock-in amplifiers, and ADS124S08 analog-to-digital converters. The two measuring electrodes of the three sets of quadrupole conductivity cells are both set in the cell body and are at the same level as the differential pressure sensors in the differential pressure sensor array module 3. The DDS chip AD98 The output end of 34 is connected to the input end of the OPA569 operational amplifier, the output end of the OPA569 operational amplifier is connected to the current electrode of the quadrupole conductivity cell, the measuring electrode of the quadrupole conductivity cell is coupled to the input end of the AD630 lock-in amplifier, the output end of the DDS chip AD9834 is coupled to the reference input end of the AD630 lock-in amplifier, the output end of the AD630 lock-in amplifier is connected to the input channel end of the ADS124S08 analog-to-digital converter, and the output end of the ADS124S08 analog-to-digital converter is coupled to the main control processing module 5; The data output end of the environmental compensation module 1 is coupled to the input end of the main control processing module 5. The environmental compensation module 1 monitors and transmits water parameters in real time. The environmental compensation module 1 includes a PT1000 temperature sensor, an OPA188 differential amplifier, and an MS5803-14BA pressure sensor. The PT1000 temperature sensor and the MS5803-14BA pressure sensor are both arranged at the middle depth of the pool body. The output end of the PT1000 temperature sensor is connected to the input end of the OPA188 differential amplifier. The output end of the OPA188 differential amplifier is connected to the ADS124S08 analog-to-digital converter in the multi-frequency impedance measurement module 2. The power terminal of the MS5803-14BA pressure sensor is connected to power and its ground terminal is grounded. The output end of the MS5803-14BA pressure sensor is connected to the main control processing module 5. The control signal output end of the main control processing module 5 is coupled to the driving input end of the output execution module 6. The main control processing module 5 performs density gradient calculation and risk decision-making and is hierarchically controlled by the output execution module 6. The main control processing module 5 includes an STM32H743 controller, a DS3231 clock chip, and a FRAM memory. The clock end of the STM32H743 controller is coupled to the DS3231 clock chip, the input and output ends of the FRAM memory are coupled to the STM32H743 controller, and the data end of the STM32H743 controller is respectively connected to the MS5803-14BA pressure sensor in the environmental compensation module 1, the ADAS3022 analog-to-digital converter in the signal conditioning module 4, and the PGA280 The programmable gain amplifier and the ADS124S08 analog-to-digital converter in the multi-frequency impedance measurement module 2 are coupled, the output execution module 6 includes an RS485 interface, a host computer, a TLP281-4 optocoupler, a relay, a gantry crane, and a submersible mixer, the RS485 interface is coupled to the STM32H743 controller in the main control processing module 5, the RS485 interface outputs data to the host computer, the input end of the TLP281-4 optocoupler is coupled to the STM32H743 controller in the main control processing module 5, the output end of the TLP281-4 optocoupler is connected to the positive pole of the relay coil, the negative pole of the relay coil is grounded, the submersible mixer is powered, and the contacts of the relay are connected in series to the power circuit of the submersible mixer; The main control processing module 5 performs density gradient calculation and risk decision making, and the output execution module 6 performs hierarchical control, which specifically includes the following steps: Preprocessing of differential pressure signal: performing quadratic polynomial correction on the original pressure value, with its coefficients stored in memory, and using temperature compensation coefficient of 0.00018 per degree Celsius to compensate the pressure value; After measuring impedance at three frequency points of 100 Hz, 1 000 Hz and 10 kHz, salinity inversion is performed by multiplying the cell constant by the ratio of the impedance modulus at 100 Hz to the impedance modulus at 10 kHz, and then multiplying by the real part of the impedance at 1 kHz, wherein the cell constant is stored in a memory; After measuring the water temperature and water depth insulation pressure values, the density difference is corrected using a pressure compensation coefficient of 2.1 times 10 to the power of negative fourth per kiloPascal. The density gradient is calculated as the bottom-top pressure difference multiplied by the reference water density of 998.2 kilograms per cubic meter, divided by the product of the acceleration of gravity of 9.80665 meters per second squared and the distance between the sensors of 2.0 meters; When the corrected density difference is between 2.0 and 5.0 kilograms per cubic meter, the risk value is 0.5 times the density difference minus 2 plus 0.3 times the normalized salinity value; when the corrected density difference is greater than or equal to 5.0 kilograms per cubic meter, the risk value is the density difference plus 0.5 times the normalized salinity value; When the risk value is between three point zero and five point zero, the gantry crane in the control output execution module 6 drives the submersible mixer to sink to the middle layer of the pool for mixing. When the risk value is greater than or equal to five point zero, the gantry crane in the control output execution module 6 drives the submersible mixer to sink to the bottom layer of the pool for mixing, and the upper computer in the output execution module 6 outputs an alarm code.

[0030] Specifically, when this system dynamically monitors the sewage treatment process, The power management module 7 provides stable power to the entire system. The differential pressure sensor array module 3 synchronously collects water pressure data at depths of 0.5 meters, 1.5 meters, and 2.5 meters across the vertical profile of the regulating pond. Its shallow differential pressure sensors monitor the pressure in the conventional COD probe sampling area, the mid-layer differential pressure sensors capture density interface changes, and the bottom differential pressure sensors directly track the high-salinity, high-COD wastewater sediment layer. The signal conditioning module 4 amplifies and filters the raw signal before transmitting it to the main control processing module 5. Simultaneously, the multi-frequency impedance measurement module 2 deploys a quadrupole conductivity cell at the same depth. It uses a 100 Hz low-frequency signal to capture free ion concentration to reflect salinity distribution, a 1000 Hz medium-frequency signal to analyze organic pollutant characteristics, and a 10,000 Hz high-frequency signal to suppress electrode polarization effects. When high-concentration pickle wastewater with chloride content greater than 1500 mg / L sinks to the bottom to form a density jump layer, the conductivity value at the bottom layer increases sharply, while the surface layer remains low. The environmental compensation module 1 uses a PT1000 temperature sensor and pressure sensor to measure the salinity distribution. The force sensor corrects for thermal expansion effects and water depth in real time. The main control processing module 5 performs core diagnostics, first comparing vertical pressure gradients. If a density difference of >3 kg / m³ at a depth of 1.5 meters and a sudden increase in bottom salinity of >500 mg / L are detected, a density isolation layer is determined to have formed. The impedance spectrum is then analyzed. The real part of the 1000 Hz impedance in the surface layer shows a low COD of approximately 300 mg / L, while the impedance value in the same frequency band in the bottom layer plummets and the 100 Hz / 10,000 Hz frequency amplitude ratio increases abnormally, revealing a pollution load of >2000 mg / L in the bottom layer. A risk index is then calculated based on the density difference and salinity gradient. When the risk value exceeds the threshold, the output execution module 6 initiates a graded response, controlling the gantry crane in the output execution module 6 to drive the submersible mixer to sink to the bottom of the pool for mixing. The host computer in the output execution module 6 then outputs an alarm code, accurately identifying COD monitoring distortion caused by high salt density stratification and effectively preventing biochemical pool impact accidents.

[0031] This system uses the density mutation revealed by the differential pressure gradient and the salinity-COD coupling relationship obtained by impedance spectrum inversion to identify the "false appearance of surface COD compliance" caused by the sedimentation of high-salinity wastewater, thereby avoiding biochemical system paralysis accidents.

[0032] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A sewage treatment dynamic monitoring system, characterized in that: It includes a differential pressure sensing array module (3), a multi-frequency impedance measurement module (2), an environmental compensation module (1), a signal conditioning module (4), a main control processing module (5), and an output execution module (6); The output end of the differential pressure sensing array module (3) is coupled to the input end of the signal conditioning module (4), and the output end of the signal conditioning module (4) is coupled to the input end of the main control processing module (5). The differential pressure sensing array module (3) collects vertical pressure data in the pool and transmits it; The impedance output end of the multi-frequency impedance measurement module (2) is coupled to the input end of the main control processing module (5), and the multi-frequency impedance measurement module (2) obtains the water body impedance spectrum and transmits it; The data output end of the environmental compensation module (1) is coupled to the input end of the main control processing module (5), and the environmental compensation module (1) monitors and transmits water parameters in real time; The control signal output terminal of the main control processing module (5) is coupled to the drive input terminal of the output execution module (6); the main control processing module (5) performs density gradient calculation and risk decision making, and the output execution module (6) performs hierarchical control.

2. A sewage treatment dynamic monitoring system according to claim 1, characterized in that: The differential pressure sensing array module (3) includes three differential pressure sensors arranged at different water depths, three AD8220 instrument amplifiers, and three groups of RC filter networks. The power connection ends of the three differential pressure sensors are all grounded, the power connection ends of the three differential pressure sensors are all electrically connected, the output ends of the three differential pressure sensors are respectively connected to the input ends of the AD8220 instrument amplifiers, and the output ends of the AD8220 instrument amplifiers are connected to the input end of the signal conditioning module (4) through the RC filter network.

3. A sewage treatment dynamic monitoring system according to claim 1, characterized in that: The signal conditioning module (4) includes three INA333 instrument amplifiers, a PGA280 programmable gain amplifier, an ADAS3022 analog-to-digital converter, and an LTC6655 reference voltage source. The input ends of the three INA333 instrument amplifiers are respectively connected to the output ends of the three groups of RC filter networks in the differential pressure sensor array module (3). The output ends of the three INA333 instrument amplifiers are all connected to the three-channel input ends of the PGA280 programmable gain amplifier. The output end of the PGA280 programmable gain amplifier is connected to the input end of the ADAS3022 analog-to-digital converter. The controlled end of the PGA280 programmable gain amplifier is connected to the control channel switching end of the main control processing module (5). The output end of the LTC6655 reference voltage source is connected to the reference voltage end of the ADAS3022 analog-to-digital converter. The clock end and the data end of the ADAS3022 analog-to-digital converter are both coupled to the main control processing module (5).

4. A sewage treatment dynamic monitoring system according to claim 1, characterized in that: The multi-frequency impedance measurement module (2) includes three DDS chips AD9834, three OPA569 operational amplifiers, three groups of quadrupole conductivity cells, three AD630 lock-in amplifiers, and an ADS124S08 analog-to-digital converter. The two measuring electrodes of the three groups of quadrupole conductivity cells are both arranged in the cell body and are located at the same horizontal height as each differential pressure sensor in the differential pressure sensor array module (3). The output end of the DDS chip AD9834 is connected to the input end of the OPA569 operational amplifier, the output end of the OPA569 operational amplifier is connected to the current electrode of the quadrupole conductivity cell, the measuring electrode of the quadrupole conductivity cell is coupled to the input end of the AD630 lock-in amplifier, the output end of the DDS chip AD9834 is coupled to the reference input end of the AD630 lock-in amplifier, the output end of the AD630 lock-in amplifier is connected to the input channel end of the ADS124S08 analog-to-digital converter, and the output end of the ADS124S08 analog-to-digital converter is coupled to the main control processing module (5).

5. A sewage treatment dynamic monitoring system according to claim 1, characterized in that: The environmental compensation module (1) includes a PT1000 temperature sensor, an OPA188 differential amplifier, and an MS5803-14BA pressure sensor. The PT1000 temperature sensor and the MS5803-14BA pressure sensor are both arranged at a middle depth in the pool body. The output end of the PT1000 temperature sensor is connected to the input end of the OPA188 differential amplifier. The output end of the OPA188 differential amplifier is connected to the ADS124S08 analog-to-digital converter in the multi-frequency impedance measurement module (2). The power terminal of the MS5803-14BA pressure sensor is connected to power and the ground terminal is grounded. The output end of the MS5803-14BA pressure sensor is connected to the main control processing module (5).

6. A sewage treatment dynamic monitoring system according to claim 1, characterized in that: The main control processing module (5) includes an STM32H743 controller, a DS3231 clock chip, and a FRAM memory. The clock end of the STM32H743 controller is coupled to the DS3231 clock chip, the input and output ends of the FRAM memory are coupled to the STM32H743 controller, and the data end of the STM32H743 controller is coupled to the MS5803-14BA pressure sensor in the environmental compensation module (1), the ADAS3022 analog-to-digital converter and the PGA280 programmable gain amplifier in the signal conditioning module (4), and the ADS124S08 analog-to-digital converter in the multi-frequency impedance measurement module (2).

7. A sewage treatment dynamic monitoring system according to claim 1, characterized in that: The output execution module (6) includes an RS485 interface, a host computer, a TLP281-4 optical coupler, a relay, a gantry crane, and a submersible mixer, wherein the RS485 interface is coupled to the STM32H743 controller in the main control processing module (5), the RS485 interface outputs data to the host computer, the input end of the TLP281-4 optical coupler is coupled to the STM32H743 controller in the main control processing module (5), the output end of the TLP281-4 optical coupler is connected to the positive pole of the coil of the relay, the negative pole of the coil of the relay is grounded, the submersible mixer is electrically connected, and the contacts of the relay are connected in series to the power circuit of the submersible mixer.

8. A sewage treatment dynamic monitoring system according to claim 1, characterized in that: The main control processing module (5) performs density gradient calculation and risk decision making, and the output execution module (6) performs hierarchical control, which specifically includes the following steps: Preprocessing of differential pressure signal: performing quadratic polynomial correction on the original pressure value, with its coefficients stored in memory, and using temperature compensation coefficient of 0.00018 per degree Celsius to compensate the pressure value; After measuring impedance at three frequency points of 100 Hz, 1 000 Hz and 10 kHz, salinity inversion is performed by multiplying the cell constant by the ratio of the impedance modulus at 100 Hz to the impedance modulus at 10 kHz, and then multiplying by the real part of the impedance at 1 kHz, wherein the cell constant is stored in a memory; After measuring the water temperature and water depth insulation pressure values, the density difference is corrected using a pressure compensation coefficient of 2.1 times 10 to the power of negative fourth per kiloPascal. The density gradient is calculated as the bottom-top pressure difference multiplied by the reference water density of 998.2 kilograms per cubic meter, divided by the product of the acceleration of gravity of 9.80665 meters per second squared and the distance between the sensors of 2.0 meters; When the corrected density difference is between 2.0 and 5.0 kilograms per cubic meter, the risk value is 0.5 times the density difference minus 2 plus 0.3 times the normalized salinity value; when the corrected density difference is greater than or equal to 5.0 kilograms per cubic meter, the risk value is the density difference plus 0.5 times the normalized salinity value; When the risk value is between 3.0 and 5.0, the gantry crane in the control output execution module (6) drives the submersible mixer to sink to the middle layer of the pool for mixing. When the risk value is greater than or equal to 5.0, the gantry crane in the control output execution module (6) drives the submersible mixer to sink to the bottom layer of the pool for mixing, and the upper computer in the output execution module (6) outputs an alarm code.

9. A sewage treatment dynamic monitoring system according to claim 1, characterized in that: It also includes a power management module (7), which supplies power to each module.

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