A sewage denitrification control system and method based on dynamic anoxic mass control

Abstract

This invention provides a wastewater denitrification control system and method based on dynamic anoxic quality control. The system is implemented based on AAO (Anoxic Aseptic) and its modified processes, and includes: a data acquisition unit for real-time acquisition of parameters such as influent flow rate, influent ammonia nitrogen concentration, influent Kjeldahl nitrogen concentration, sludge return flow rate, internal circulation return flow rate, and ammonia nitrogen and nitrate nitrogen concentrations at the end of the pre-anoxic tank; a data processing unit for receiving the parameter information acquired by the data acquisition unit, processing the data to obtain the current operating status, and generating control commands based on the current operating status; and a control unit for receiving the control commands sent by the data processing unit and controlling the actions of each actuator in the biological unit according to the corresponding control commands, adjusting the operating parameters of the biological unit. This invention successfully solves the time delay problem of traditional control decisions, fills the gap in traditional control strategies regarding denitrification control, and can treat domestic wastewater in a timely and efficient manner.

Description

Technical Field

[0001] This invention relates to the field of environmental engineering technology, and in particular to a wastewater denitrification control system and method based on dynamic anoxic quality control. Background Technology

[0002] In the field of wastewater treatment, achieving efficient and stable biological nitrogen removal is a core challenge. To meet increasingly stringent emission standards and the demand for energy conservation and emission reduction, advanced process control technologies are constantly evolving. Among them, ABAC (Ammonia-Based Aeration Control) and AvN (Ammonia vs. NOx) represent relatively cutting-edge control concepts. Taking the AAO (Anaerobic-Anoxic-Aerobic) process as an example, the advantages and disadvantages of the two control methods are as follows:

[0003] ABAC control: This method dynamically adjusts the aeration rate by monitoring the ammonia nitrogen concentration at the end of the aerobic tank, thereby optimizing the nitrification process through energy conservation. However, its control logic is limited to the aerobic stage and lacks direct guidance for the denitrification process, which can easily lead to a disconnect between carbon source addition and aeration control.

[0004] AvN control: By real-time monitoring and control of the ratio of ammonia nitrogen (NH4⁺-N) to nitrate nitrogen (NOx--N) at the end of the aerobic tank, the short-cut denitrification process is optimized, reducing oxygen consumption and carbon source demand. AvN technology has been successfully applied in wastewater treatment plants such as Boat Harbor in the United States and Strass in Austria, providing support for achieving energy self-sufficiency.

[0005] However, existing advanced control technologies still have the following key limitations:

[0006] Control lag: The core monitoring points of both ABAC and AvN are located at the end of the aerobic tank. Control decisions are based on the results of the "completed" nitrification process, which is a form of ex-post feedback control. When the system deviates from its state due to factors such as influent shock or temperature changes, the regulation has an inherent delay, reducing the system's shock resistance and response speed.

[0007] The lack of direct assessment of the pre-anoxic tank process: Denitrification occurs in the pre-anoxic tank, but current technologies do not establish core monitoring points in this critical area. Therefore, it is impossible to quantify the nitrogen removal efficiency and load status in this area in real time, making it difficult to achieve precise and proactive control of carbon source addition.

[0008] Insufficient adaptability to dynamic operating conditions: Under actual operating conditions where influent water quality (such as ammonia nitrogen concentration, C / N ratio) fluctuates frequently, it is difficult to distinguish between nitrification efficiency problems and denitrification / carbon source limitation problems. Control strategies based on end-point feedback cannot completely avoid temporary over-addition of carbon sources or over-aeration, leading to increased operating costs and energy waste. Summary of the Invention

[0009] In view of the above-mentioned problems in the prior art, the present invention provides a wastewater denitrification control system and method based on dynamic anoxic quality control to solve the technical problems of time delay in traditional control decisions and the lack of denitrification control process in traditional control strategies.

[0010] This invention provides a wastewater denitrification control system based on dynamic anoxic quality control, implemented using AAO and its improved processes, including:

[0011] The data acquisition unit is used to collect in real time the influent flow rate, influent ammonia nitrogen concentration, influent Kjeldahl nitrogen concentration, sludge return flow rate, internal circulation return flow rate, and ammonia nitrogen and nitrate nitrogen concentration parameters at the end of the pre-anoxic tank of the AAO and its improved process biochemical unit.

[0012] The data processing unit receives parameter information collected by the data acquisition unit, processes the data to obtain the current operating status, and generates control commands based on the current operating status.

[0013] The control unit receives control commands sent by the data processing unit and controls the actions of each actuator in the biochemical unit according to the corresponding control commands, adjusting the operating parameters of the biochemical unit, including the internal circulation return flow rate, sludge return flow rate, carbon source dosage, and aeration rate of the aerobic tank.

[0014] In one embodiment, the ammonia nitrogen and nitrate nitrogen concentration information at the end of the pre-anoxic tank is collected by an online ammonia nitrogen and nitrate nitrogen analyzer installed at the pre-control point of the pre-anoxic tank.

[0015] In one embodiment, the pre-control point is located at the end 1 / 3 of the pre-anoxic pool.

[0016] In addition, embodiments of the present invention also provide a wastewater denitrification control method based on dynamic anoxic quality control, implemented based on the wastewater denitrification control system as described in any embodiment of the present invention, comprising the following steps:

[0017] Step S1: Real-time data acquisition, real-time acquisition of influent flow rate and influent ammonia nitrogen concentration of the AAO and its improved process biochemical unit. Influent Kjeldahl nitrogen concentration (TKN), sludge return flow rate, internal circulation return flow rate, and ammonia nitrogen concentration at the end of the pre-anaerobic tank. With nitrate nitrogen concentration Parameter information, and calculate the internal circulation reflux ratio. Sludge return ratio data;

[0018] Step S2, calculate dynamics Center setting value

[0019] ·

[0020] in, This is a process correction factor, with a value ranging from 0.9 to 1.1;

[0021] Step S3: Calculate the operational stability index ,

[0022] make

[0023]

[0024] in, and This represents the range of ammonia nitrogen and nitrate nitrogen concentrations in the pre-anaerobic tank under normal operating conditions of the biochemical unit. The denitrification limit target value for nitrate nitrogen. and These represent the degree of deviation of the ammonia nitrogen concentration and nitrate nitrogen concentration in the pre-anaerobic tank from the target ammonia nitrogen concentration and nitrate nitrogen concentration, respectively.

[0025] Step S4, execute collaborative early warning and control, based on and , Each component deviates from its designated direction, and aeration, internal circulation, and carbon source addition are adjusted in a coordinated manner.

[0026] In one embodiment, the process correction factor The initial value is 1.0, and it is adaptively corrected by the data processing unit based on historical operating data every set interval.

[0027] In one embodiment, the process correction factor By comparing the total Kjeldahl nitrogen concentration (TKN) in the influent with the ammonia nitrogen concentration at the pre-control point... The difference relationship enables adaptive calibration correction.

[0028] In one embodiment, in step S4,

[0029] when When the value is 0-1, maintain the existing control parameters and continuously monitor the system;

[0030] when If the value is greater than 1, check the ammonia nitrogen concentration. With nitrate nitrogen concentration ,

[0031] like Less than 1 and If the value is less than 1, maintain the existing control parameters and continue monitoring the system.

[0032] like Greater than 1 and Less than 1,

[0033] examine If it remains below the minimum value of the fixed window, reduce the aeration rate; if it remains above the maximum value of the fixed window, increase the aeration rate.

[0034] like Greater than 1 and Greater than 1,

[0035] like It remains below the minimum value of the fixed window, and If the temperature remains below the minimum value of the window, reduce the aeration rate and simultaneously reduce the carbon source dosage.

[0036] like It remains below the minimum value of the fixed window, and If the aeration rate remains consistently above the maximum value within the window, reduce the aeration rate and increase the carbon source dosage.

[0037] like It remains consistently higher than the maximum value within a fixed window, and If the temperature remains below the minimum value within the window, increase the aeration rate and decrease the carbon source dosage.

[0038] like It remains consistently higher than the maximum value within a fixed window, and If the aeration rate remains above the maximum value within the window, increase the aeration rate and the carbon source dosage.

[0039] like Less than 1 and Greater than 1,

[0040] like If the value remains below the minimum value within the fixed window, reduce the amount of carbon source added;

[0041] like Continuously exceeding the maximum value of the fixed window increases the internal circulation reflux ratio.

[0042] Compared with the prior art, the beneficial effects of the wastewater denitrification control system and method based on dynamic anoxic quality control provided by the embodiments of the present invention are as follows:

[0043] 1. Good real-time performance: The embodiments of the present invention achieve "in-process control" of denitrification and nitrification processes through pre-process PCC, significantly shortening the response time;

[0044] 2. Dynamic adaptation: The dynamic mass balance model in this embodiment of the invention can automatically adjust according to the influent load and return ratio. It can adapt to complex working conditions;

[0045] 3. Accurate diagnosis; embodiments of the present invention achieve this through... and Proportional analysis accurately distinguishes nitrification / denitrification limitation scenarios, effectively avoiding miscontrol.

[0046] 4. Energy saving and consumption reduction: The embodiments of the present invention can automatically reduce the aeration set value, carbon source dosage or internal reflux ratio, thereby reducing energy consumption while ensuring denitrification efficiency. Attached Figure Description

[0047] Figure 1 A schematic diagram of a wastewater denitrification control system based on dynamic anoxic quality control provided in an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of a triple control loop involved in a wastewater denitrification control method based on dynamic anoxic quality control, provided as an embodiment of the present invention.

[0049] Figure label:

[0050] 1. Inlet well; 2. Inlet flow meter; 3. Inlet ammonia nitrogen analyzer; 4. Inlet Kjeldahl nitrogen analyzer; 5. Data processing unit; 6. Control unit; 7. Anaerobic tank; 8. Anoxic tank; 9. Aerobic tank; 10. Carbon source dosing pump; 11. Online ammonia nitrogen and nitrate nitrogen analyzer; 12. Blower; 13. Flow promoter; 14. Internal return pump; 15. Aerator; 16. Aeration pipe; 17. Secondary sedimentation tank; 18. Sludge return pump; 19. Sludge return flow meter; 20. Wastewater pipeline; 21. Nitrified liquor return pipe; 22. Sludge return pipe. Detailed Implementation

[0051] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0053] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0054] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0055] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0056] Specific embodiments of this application are described below with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to ascertain the true intent based on the user's historical operations, and to avoid unnecessary or redundant details that would obscure this application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in various ways with substantially any suitable detailed structure.

[0057] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0058] The principles and features of the present invention are described below with reference to the accompanying drawings. The embodiments described are for illustrative purposes only and are not intended to limit the scope of the invention. The following description, in conjunction with... Figure 1 The preferred embodiments of the present invention will be described in further detail below:

[0059] This invention belongs to the field of environmental engineering, specifically relating to biological nitrogen removal technology in wastewater treatment. It is applicable to A / A / O (anaerobic-anoxic-aerobic) processes and their improved versions, and is an intelligent control method and system for biological ponds based on a dynamic mass balance model and dual-indicator early warning. Name: Dynamic Anoxic Mass Control (DAMC).

[0060] To overcome the shortcomings of existing technologies, this invention provides a monitoring means and control method that takes into account both the denitrification and ammonia nitrogen removal processes. This provides a new control approach for municipal wastewater treatment plants, successfully solves the time delay of traditional control decisions, fills the gap in traditional control strategies for denitrification control, and can treat domestic sewage in a timely and efficient manner.

[0061] like Figure 1-2 As shown, this embodiment of the invention provides a wastewater denitrification control system based on dynamic anoxic quality control, implemented based on AAO and its improved processes, including:

[0062] Data acquisition unit, data processing unit 5 and control unit 6;

[0063] The data acquisition unit collects relevant data and relevant parameters of specific points in the biochemical unit and transmits them to the data processing unit 5.

[0064] The data processing unit 5 interacts with the control unit 6;

[0065] The data processing unit 5 makes a judgment based on the information sent by the data acquisition unit and outputs relevant control signals to the control unit 6. The control unit 6 performs precise control of the system according to the corresponding instructions. The data acquisition unit includes an online ammonia nitrogen and nitrate nitrogen analyzer 11, an influent flow meter 2, a sludge return flow meter 19, a nitrification liquid return flow meter, an influent ammonia nitrogen analyzer 3, and an influent Kjeldahl nitrogen detector 4.

[0066] The inlet flow meter 2, inlet ammonia nitrogen analyzer 3, and inlet Kjeldahl nitrogen detector 4 are installed in the inlet well 1 to collect inlet flow, ammonia nitrogen concentration and Kjeldahl nitrogen concentration.

[0067] The sludge return flow meter 19 is installed on the sludge return pipe 22 to collect the sludge return flow rate and calculate the real-time sludge return ratio in conjunction with the influent flow rate.

[0068] The nitrification liquid return flow meter is installed on the nitrification liquid return pipe 21 to collect the nitrification liquid return flow rate. Combined with the inlet water flow rate, the real-time internal circulation return ratio is calculated. If the internal return is achieved by a through-wall pump, since it is impossible to install a flow meter on the pump, the internal return flow rate is generally estimated based on the number of return pumps turned on and the rated flow rate of each pump, and then the real-time internal circulation return ratio is calculated.

[0069] The biochemical unit is the AAO process and its variations in the wastewater treatment system, including at least an anaerobic tank 7, an anoxic tank 8, an aerobic tank 9 and a secondary sedimentation tank 17, and auxiliary equipment including a flow promoter 13, an aeration pipe 16, an aerator 15, etc.

[0070] The pretreated wastewater flows sequentially through anaerobic tank 7, anoxic tank 8, and aerobic tank 9. In aerobic tank 9, Kjeldahl nitrogen in the wastewater is converted into nitrate through nitrification. The sludge mixture containing nitrate is returned to anoxic tank 8 via internal return pump 14. In the presence of a carbon source, it is converted into nitrogen gas through denitrification in anoxic tank 8 and enters the atmosphere to rejoin the nitrogen cycle.

[0071] The specific location of the biochemical unit is at the end 1 / 3 of the anoxic pool 8. An online ammonia nitrogen and nitrate nitrogen analyzer 11 is installed here to collect the concentrations of ammonia nitrogen and nitrate nitrogen at this location, ensuring the capture of denitrification tail flow characteristics. The instrument used is a high-precision online instrument (ammonia nitrogen accuracy ±0.1 mg / L, nitrate nitrogen accuracy ±0.2 mg / L).

[0072] The actuators controlled by the control unit 6 refer to a collection of devices that adjust and change the basic parameters in the biochemical unit, including blower 12, internal return pump 14, sludge return pump 18, carbon source dosing pump 10 (dosing pump), etc.

[0073] As a further technical solution, this embodiment of the invention also provides a wastewater denitrification control method based on dynamic anoxic quality control, wherein the control logic corresponding to the method is the processing logic of the data processing unit 5.

[0074] The data processing unit 5 and the control unit 6 are implemented based on a PLC control unit, and the corresponding control method includes the following steps:

[0075] 1) Set the pre-control checkpoint (PCC):

[0076] An online ammonia nitrogen (AM) setting was installed at the end of the anoxic tank 8 of the biological reactor. ) sensor and nitrate nitrogen ( The sensor is the online ammonia nitrogen and nitrate nitrogen analyzer 11.

[0077] 2) Real-time data acquisition:

[0078] Real-time acquisition of ammonia nitrogen concentration at PCC ( ), nitrate nitrogen concentration ( ), and the concentration of ammonia nitrogen in the influent ( Real-time internal circulation reflux ratio ( ) and sludge return ratio ( Data. Pollutant concentrations are in mg / L, and reflux ratios are in %.

[0079] Here For aerobic tank 9, this is a feed-forward signal. For anoxic pool 8, it is a feedback signal.

[0080] 3) Calculate dynamics Center setting value ( )

[0081] Based on the real-time influent load and return ratio, the following calculations are performed using a dynamic mass balance model:

[0082] ·

[0083] in This is a process correction factor, ranging from 0.9 to 1.1, which is a comprehensive coefficient used to balance ammonification (conversion of organic nitrogen to ammonia nitrogen, leading to an increase in ammonia nitrogen) and microbial assimilation (cellular synthesis consuming ammonia nitrogen, leading to a decrease in ammonia nitrogen) in the anaerobic / anoxic phase. When... A value >1.0 indicates that ammoniation is greater than assimilation (common in influent with high organic nitrogen content); when When the value is less than 1.0, it indicates that assimilation is dominant. The initial value was 1.0, and it was adaptively corrected every 72 hours based on historical data. The difference between the influent total Kjeldahl nitrogen (TKN) and the ammonia nitrogen at the PCC was compared to... The values ​​are adaptively calibrated to compensate for changes in the ammoniation rate caused by seasonal temperature variations. The adaptive calibration rules are based on historical performance data of the system.

[0084] 4) Calculate the operational stability index ( ):

[0085] Define operational stability indicators It is used to quantify the deviation between the actual PCC monitoring value and the dynamic target value (for ease of subsequent discussion, it is introduced here). and (representing the two absolute values ​​respectively).

[0086]

[0087] Where W is the preset fixed window range, i.e. The variation range of the pre-anoxic tank 8 under normal production conditions. for The target value for the denitrification limit, and These represent the degree of deviation of the ammonia nitrogen concentration and nitrate nitrogen concentration in the pre-anoxic tank from the target ammonia nitrogen concentration and nitrate nitrogen concentration, respectively.

[0088] 5) Implement collaborative early warning and control:

[0089] according to and , Each component deviates from its designated direction, and aeration, internal circulation, and carbon source addition are adjusted in a coordinated manner.

[0090] In this embodiment of the invention, the control logic of the data processing unit 5 is as follows: When A value of 0-1 indicates that ammonia nitrogen and nitrate nitrogen are definitely within a fixed window. In this case, the existing control parameters should be maintained, and the system should be continuously monitored. Scenario I is triggered at this time.

[0091] when A value greater than 1 indicates that the system's operating status may have deviated to some extent, and the larger the value, the greater the degree of deviation. In this case, the concentrations of ammonia nitrogen and nitrate nitrogen should be checked.

[0092] like Less than 1 and A value less than 1 indicates that the system is stable and the existing control parameters should be maintained while the system is continuously monitored; at this time, scenario I is triggered.

[0093] like Greater than 1, and Less than 1.

[0094] Check at this time If the aeration rate remains below the minimum value of the fixed window, it indicates that the nitrification capacity is too strong. In this case, the aeration rate should be appropriately reduced to achieve energy saving, thus triggering Scenario II. If the aeration rate remains above the maximum value of the fixed window, it indicates that the nitrification capacity is insufficient. In this case, the aeration rate should be increased to improve the ammonia nitrogen removal capacity of the system, thus triggering Scenario III.

[0095] like Greater than 1, and Greater than 1.

[0096] examine If it remains below the minimum value of the fixed window, and If the value remains below the minimum value of the window, it indicates that the nitrification capacity is too strong and the denitrification capacity is too strong. At this time, the aeration rate should be appropriately reduced, and the carbon source dosage should also be reduced to achieve energy saving. At this time, scenario II is triggered.

[0097] examine If it remains below the minimum value of the fixed window, and If the value remains above the maximum value in the window, it indicates that the nitrification capacity is too strong while the denitrification capacity is insufficient. At this time, the aeration rate should be appropriately reduced and the carbon source dosage should be appropriately increased, which will trigger Scenario III.

[0098] examine If it remains higher than the highest value of the fixed window, and If the value remains below the minimum value in the window, it indicates insufficient nitrification capacity and excessive denitrification capacity. In this case, it is appropriate to increase the aeration rate and reduce the carbon source dosage, thus triggering Scenario III.

[0099] examine If it remains higher than the highest value of the fixed window, and If the value remains consistently higher than the maximum value in the window, it indicates that the system has poor denitrification capacity. At this point, it is appropriate to increase the aeration rate and the carbon source dosage, which will trigger Scenario III.

[0100] like Less than 1, and Greater than 1.

[0101] Check at this time If it remains below the minimum value of the fixed window, it indicates that the denitrification capacity is too strong. At this time, the carbon source dosage can be reduced, and scenario II will be triggered.

[0102] If it remains above the maximum value of the fixed window, it indicates poor denitrification; try increasing the internal recirculation reflux ratio. At this point, Scenario III is triggered.

[0103] In addition, when abnormal data is detected in the online ammonia nitrogen and nitrate nitrogen analyzer 11 (such as a constant reading or exceeding physical limits), the control unit 6 automatically switches to the degraded safety mode, which uses a fixed DO setpoint and a fixed reflux ratio control based on the influent flow rate.

[0104] The judgment and control actions for each operating condition are listed below.

[0105]

[0106] Example 1

[0107] 1.1 Project Overview and Basic Parameters

[0108] Taking a municipal wastewater treatment plant as an example, its designed capacity is 100,000 tons / day, and its effluent standard meets the Class III surface water standard. ≤1.0 mg / L, TN≤15 mg / L, the plant control target is TN≤8 mg / L. Influent Concentration range: 30~40 mg / L, effluent The concentration is usually controlled below 0.1 mg / L, and the effluent... Controlled below 8 mg / L, internal circulation reflux ratio The sludge return ratio is 300%. The result was 100%. Long-term monitoring showed that the end of the anoxic pool... The concentration range is 6~8 mg / L. The concentration range is 1~2 mg / L.

[0109] Set denitrification baseline target value This parameter is set at 1.5 mg / L. Basis for setting this value: This value is based on process limits. Since the internal recirculation (300%) inevitably carries a small amount of dissolved oxygen (DO) from the aerobic tank to the end of the anoxic tank, based on engineering experience, this DO consumes some readily biodegradable carbon sources, making it difficult to reduce nitrate nitrogen at the PCC to 0 mg / L at the economically viable dosage. Therefore, 1.5 mg / L is set as the "technologically and economically optimal balance point." When the actual value is <1.5 mg / L: it indicates extremely thorough denitrification, possibly with carbon source waste. When the actual value is >1.5 mg / L: it indicates denitrification is hindered, requiring intervention through adjusting the recirculation or adding a carbon source.

[0110] 1.2 Control Unit Initialization

[0111] In this case, the process correction factor f is initially set to 1.0 (assuming that ammoniation and assimilation are basically in balance in the anaerobic / anoxic stage).

[0112] The dynamic window width and empirical center values ​​for nitrate nitrogen are as follows:

[0113] Ammonia nitrogen window width: =8-6=2 mg / L;

[0114] Nitrate window width: =2-1=1 mg / L;

[0115] Target value for nitrate nitrogen: =1.5 mg / L (taken as the average value of long-term monitoring).

[0116] 1.3 Calculation and Verification of Dynamic Setpoints

[0117] Real-time calculation of dynamics at PCC The central setpoint serves as the control hub for subsequent control. ·

[0118] When water enters At a concentration of 30 mg / L,

[0119]

[0120] The dynamic window range at this time is 6.0 ± (2.0 / 2) = 5~7 mg / L

[0121] When water enters At a concentration of 40 mg / L,

[0122]

[0123] The dynamic window range at this time is 8.0 ± (2.0 / 2) = 7~9 mg / L

[0124] Conclusion: The dynamic center value range (6.0~8.0 mg / L) calculated by the model is in complete agreement with the long-term measured data at the PCC, proving that the dynamic mass balance model can accurately reflect the linear relationship between influent load and dilution effect, and has the scientific validity to serve as a feedforward control benchmark.

[0125] 1.4 Demonstration of Typical Control Process

[0126] Scenario 1 (Smooth Operation):

[0127] System status: Influent ammonia nitrogen 35 mg / L (calculated) =7.0), PCC measured ammonia nitrogen 7.2 mg / L, nitrate nitrogen 1.4 mg / L.

[0128] determination:

[0129]

[0130] Action: The system determines the scenario as Scenario I, maintaining the current 9DO setting and reflux ratio of the aerobic tank unchanged to avoid unnecessary adjustment fluctuations.

[0131] Scenario 2 (Nitrification Load Shock Early Warning):

[0132] Status: Influent ammonia nitrogen remains at 35 mg / L (calculated). =7.0), but the PCC measured ammonia nitrogen suddenly rose to 9.5 mg / L.

[0133] Judgment: The measured value (9.5) is significantly higher than the upper limit of the dynamic window (7.0 + 1.0 = 8.0). This indicates that there may be an accelerated ammonification rate in anaerobic zone 7 or a sudden increase in nitrogenous organic matter in the influent, causing the actual ammonia nitrogen load entering aerobic tank 9 to exceed the predicted value of physical dilution.

[0134] Action: Trigger Scene III (Nitrification Limitation).

[0135] The control unit utilizes the feedforward characteristics of the PCC to immediately increase the 9DO setpoint of the aerobic tank by 0.3 mg / L (from 2.0 to 2.3 mg / L) without waiting for the aerobic effluent to exceed the standard.

[0136] Results: The nitrification rate of aerobic tank 9 was increased, which successfully offset the high load shock, and the final effluent ammonia nitrogen was kept below 0.1 mg / L.

[0137] Scenario 3: Limited Denitrification and Carbon Source Addition

[0138] Status: PCC measured nitrate nitrogen rose to 4.0 mg / L (far exceeding the central value of 1.5 mg / L), while ammonia nitrogen was normal.

[0139] Judgment: The denitrification efficiency of anoxic tank 8 is seriously insufficient.

[0140] Control logic:

[0141] 1. The system first checks The current value is 300%.

[0142] 2. Calculate PCC Proportion.

[0143] 3. If the hydraulic residence time is determined to be insufficient, the system will prioritize... Increased to 350%.

[0144] 4. If 1 hour later If the concentration is still above 3.0 mg / L, it is determined that the carbon source is insufficient. The system automatically starts the external carbon source dosing pump and adds sodium acetate according to the calculated amount.

[0145] Results: Through the coordinated regulation of reflux and carbon source, nitrate nitrogen at PCC dropped to 1.5 mg / L, ensuring that the total TN in the effluent consistently met the standard.

[0146] Scenario 4: Low-load energy saving

[0147] Status: Ammonia nitrogen in the influent decreased to 25 mg / L overnight (calculated). =5.0). PCC measured ammonia nitrogen 3.0 mg / L, nitrate nitrogen 0.8 mg / L.

[0148] Judgment: Ammonia nitrogen is below the lower limit of the dynamic window (5.0 - 1.0 = 4.0), and nitrate nitrogen is extremely low. This indicates that the biochemical system has excess processing capacity at this time.

[0149] Action: Trigger Scene II (Overprocessing).

[0150] The system automatically reduced the 9DO setpoint in the aerobic tank by 0.2 mg / L (down to a minimum of 1.5 mg / L) and suspended carbon source addition.

[0151] Results: While ensuring compliance with standards, the energy consumption and reagent costs of blower 12 were significantly reduced.

[0152] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A wastewater denitrification control system based on dynamic anoxic quality control, implemented based on AAO and its improved processes, characterized in that, include: The data acquisition unit is used to collect in real time the influent flow rate, influent ammonia nitrogen concentration, influent Kjeldahl nitrogen concentration, sludge return flow rate, internal circulation return flow rate, and ammonia nitrogen and nitrate nitrogen concentration parameters at the end of the pre-anoxic tank of the AAO and its improved process biochemical unit. The data processing unit receives parameter information collected by the data acquisition unit, processes the data to obtain the current operating status, and generates control commands based on the current operating status. The control unit receives control commands sent by the data processing unit and controls the actions of each actuator in the biochemical unit according to the corresponding control commands, adjusting the operating parameters of the biochemical unit, including the internal circulation return flow rate, sludge return flow rate, carbon source dosage, and aeration rate of the aerobic tank.

2. The wastewater denitrification control system based on dynamic anoxic quality control according to claim 1, characterized in that: The ammonia nitrogen and nitrate nitrogen concentration information at the end of the pre-anoxic tank is collected by an online ammonia nitrogen and nitrate nitrogen analyzer set at the pre-control point of the pre-anoxic tank.

3. The wastewater denitrification control system based on dynamic anoxic quality control according to claim 1, characterized in that: The pre-control point is located at the end 1 / 3 of the pre-anoxic pool.

4. A wastewater denitrification control method based on dynamic anoxic quality control, implemented based on the wastewater denitrification control system as described in any one of claims 1-3, characterized in that, Includes the following steps: Step S1: Real-time data acquisition, real-time acquisition of influent flow rate and influent ammonia nitrogen concentration of the AAO and its improved process biochemical unit. Influent Kjeldahl nitrogen concentration (TKN), sludge return flow rate, internal circulation return flow rate, and ammonia nitrogen concentration at the end of the pre-anaerobic tank. With nitrate nitrogen concentration Parameter information, and calculate the internal circulation reflux ratio. Sludge return ratio data; Step S2, calculate dynamics Center setting value · in, This is a process correction factor, with a value ranging from 0.9 to 1.1; Step S3: Calculate the operational stability index , make in, and This represents the range of ammonia nitrogen and nitrate nitrogen concentrations in the pre-anaerobic tank under normal operating conditions of the biochemical unit. This represents the denitrification limit target value for nitrate nitrogen. and These represent the degree of deviation of the ammonia nitrogen concentration and nitrate nitrogen concentration in the pre-anaerobic tank from the target ammonia nitrogen concentration and nitrate nitrogen concentration, respectively. Step S4, execute collaborative early warning and control, based on and , Each component deviates from its designated direction, and aeration, internal circulation, and carbon source addition are adjusted in a coordinated manner.

5. The wastewater denitrification control method based on dynamic anoxic quality control according to claim 4, characterized in that: The process correction factor The initial value is 1.0, and it is adaptively corrected by the data processing unit based on historical operating data every set interval.

6. The wastewater denitrification control method based on dynamic anoxic quality control according to claim 5, characterized in that: The process correction factor By comparing the total Kjeldahl nitrogen concentration (TKN) in the influent with the ammonia nitrogen concentration at the pre-control point... The difference relationship enables adaptive calibration correction.

7. The wastewater denitrification control method based on dynamic anoxic quality control according to claim 4, characterized in that: In step S4, when When the value is 0-1, maintain the existing control parameters and continuously monitor the system; when If the value is greater than 1, check the ammonia nitrogen concentration. With nitrate nitrogen concentration , like Less than 1 and If the value is less than 1, maintain the existing control parameters and continue monitoring the system. like Greater than 1 and Less than 1, examine If it remains below the minimum value of the fixed window, reduce the aeration rate; if it remains above the maximum value of the fixed window, increase the aeration rate. like Greater than 1 and Greater than 1, like It remains below the minimum value of the fixed window, and If the temperature remains below the minimum value of the window, reduce the aeration rate and simultaneously reduce the carbon source dosage. like It remains below the minimum value of the fixed window, and If the aeration rate remains consistently above the maximum value within the window, reduce the aeration rate and increase the carbon source dosage. like It remains consistently higher than the maximum value within the fixed window, and If the temperature remains below the minimum value within the window, increase the aeration rate and decrease the carbon source dosage. like It remains consistently higher than the maximum value within the fixed window, and If the aeration rate remains above the maximum value within the window, increase the aeration rate and the carbon source dosage. like Less than 1 and Greater than 1, like If the value remains below the minimum value within the fixed window, reduce the amount of carbon source added; like Continuously exceeding the maximum value of the fixed window increases the internal circulation reflux ratio.

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