Method and system for operation control of sewage treatment plant

Abstract

The present disclosure relates to a sewage treatment plant operation control method and system. The operation control method applied to a sewage treatment system comprises: obtaining a functional relationship between the settling flux and the sludge concentration of the secondary sedimentation tank; obtaining a first solid flux value corresponding to the settling flux under the current sludge concentration condition of the secondary sedimentation tank according to the functional relationship; obtaining a second solid flux value corresponding to the intersection position of the underflow flux and the overflow flux of the secondary sedimentation tank under the current sludge concentration condition; and controlling the dosing module to start the dosing mode when the second solid flux value is greater than the first solid flux value.

Description

Technical Field

[0001] This disclosure relates to the field of terminal technology, and in particular to an operation control method and system for a wastewater treatment plant. Background Technology

[0002] As the main facilities responsible for sewage treatment and discharge, strengthening the treatment capacity of urban sewage treatment plants is of great significance for controlling sewage overflow pollution and improving the urban water environment.

[0003] Currently, in most wastewater treatment plant operation strategies, to improve the wastewater treatment capacity during rainy days, the common methods are to increase the stable load of the biological treatment unit and the operating load of the secondary sedimentation tank unit. For the secondary sedimentation tank unit, this is mainly achieved by directly adding flocculants to increase its operating load, sometimes even before the unit's operating boundary conditions are met. This leads to increased operating costs, and the addition of flocculants can also cause secondary environmental pollution. Summary of the Invention

[0004] This disclosure provides an operation control method and system for a wastewater treatment plant to address the shortcomings of related technologies.

[0005] According to a first aspect of the present disclosure, an operation control method for a wastewater treatment plant is provided, applied to a wastewater treatment system, the operation control method comprising: Obtain the functional relationship between the settling flux and sludge concentration in the secondary sedimentation tank; Based on the aforementioned functional relationship, obtain the first solids flux value corresponding to the sedimentation flux of the secondary sedimentation tank under the current sludge concentration conditions. Based on the changes in bottom flow rate and overflow flow rate, obtain the second solids flux value when the intersection of the bottom flow rate and overflow flow rate is at the current sludge concentration condition; When the second solid flux value is greater than the first solid flux value, the dosing module is controlled to start the dosing mode.

[0006] Optionally, obtaining the functional relationship between the settling flux and sludge concentration in the secondary settling tank includes: Obtain the sludge concentration and sludge settling rate measurements in the secondary sedimentation tank, and calculate the initial settling rate constant and settling velocity decay constant in the sludge settling model. Based on the initial settling rate constant and the settling velocity decay constant, the functional relationship between settling flux and sludge concentration is obtained.

[0007] Optionally, obtaining the second solids flux value at the intersection of the bottom flow rate and the overflow flow rate of the secondary sedimentation tank under the current sludge concentration conditions includes: Obtain the inflow rate and return ratio; Based on the inflow rate and the return ratio, the bottom flow rate and overflow rate of the secondary sedimentation tank under the current sludge concentration conditions are obtained; Using sludge concentration as the independent variable and solids flux as the dependent variable, the change in bottom flow rate is obtained based on the bottom flow rate, and the change in overflow flow rate is obtained based on the overflow rate, such that the intersection of the changes in bottom flow rate and overflow flow rate corresponds to the current sludge concentration condition.

[0008] Optional, also includes: Obtain the functional relationship between inflow rate and drug dosage; The dosage of the drug is obtained based on the aforementioned functional relationship and the real-time inflow water flow.

[0009] Optional, also includes: The first dosage is obtained based on the suspended solids concentration in the effluent from the secondary sedimentation tank and the first set threshold. The second dosage is obtained based on the inflow rate of the secondary sedimentation tank and the inflow rate of the previous control cycle. The third dosage is obtained based on the total effluent suspended solids concentration and the total suspended solids effluent standard of the wastewater treatment system. The dosage for the current control cycle is calculated based on the first, second, and third dosages, as well as the dosage for the previous control cycle. The dosage for the initial control cycle is obtained based on the aforementioned functional relationship and the real-time inflow water flow.

[0010] Optionally, obtaining the first dosage based on the suspended solids concentration in the secondary sedimentation tank effluent and a set threshold includes: Obtain the difference between the suspended solids concentration in the effluent of the secondary sedimentation tank and the set threshold within the current control cycle; according to Calculate the first dosage for the current control cycle; in, This is the first dosage for the current control cycle; This is the difference between the suspended solids concentration in the secondary sedimentation tank effluent and the set threshold during the current control cycle. This is the difference between the concentration of suspended solids in the secondary sedimentation tank effluent and the set threshold value in the previous control cycle. is a constant coefficient.

[0011] Optionally, obtaining the second dosage based on the inflow rate of the secondary sedimentation tank and the inflow rate of the previous control cycle includes: Calculate the rate of change of the inflow rate based on the inflow rate of the previous control cycle and the inflow rate of the current control cycle. When the absolute value of the rate of change is less than or equal to the set rate of change, the second dosage is 0; When the absolute value of the rate of change is greater than the set rate of change, according to Calculate the second dosage; in, This is the second dosage for the current control cycle; This represents the rate of change of inflow rate during the current control cycle. This refers to the drug dosage in the previous control period.

[0012] Optionally, a third dosage is obtained based on the total effluent suspended solids concentration and the total suspended solids effluent standard of the wastewater treatment system, including: Calculate the safety margin based on the total suspended solids concentration in the effluent and the total suspended solids effluent standard during the current control cycle; Calculate the third dosage using the following formula; ; ; in, For safety margin, and greater than 0; The total suspended solids effluent standard; This represents the total suspended solids concentration in the effluent during the current control cycle. This is the third dosage within the current control cycle; Set a value for the safety margin; This refers to the drug dosage in the previous control period; is a constant coefficient.

[0013] Optionally, it may also include at least one of the following: When the effluent ammonia nitrogen concentration is obtained and exceeds the critical value, the aeration rate of the aeration device in the biological unit is increased. Obtain the total nitrogen concentration in the effluent, and when the total nitrogen concentration in the effluent exceeds the critical value of nitrogen concentration, control the amount of carbon source added by the biochemical unit. Obtain the total phosphorus concentration in the effluent, and when the total phosphorus concentration in the effluent exceeds the critical value for phosphorus concentration, increase the dosage of phosphorus removal agent in the pipeline between the secondary sedimentation tank and the biological treatment unit.

[0014] According to a second aspect of the present disclosure, an operation control system for a wastewater treatment plant is provided, comprising: Feedforward monitoring module; Dosing module; The processing module is electrically connected to the dosing module and the feedforward monitoring module, respectively. The processing module is used to obtain the functional relationship between the settling flux and sludge concentration of the secondary sedimentation tank; obtain the first solids flux value corresponding to the intersection of the bottom flow rate and the overflow flow rate of the secondary sedimentation tank under the current sludge concentration condition; obtain the second solids flux value corresponding to the settling flux under the current sludge concentration condition based on the functional relationship; and control the dosing module to start the dosing mode when the first solids flux value is greater than the second solids flux value.

[0015] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: As can be seen from the above embodiments, this disclosure determines whether the operating load of the secondary sedimentation tank is exceeded by comparing the second solid flux value with the first solid flux value under the current concentration conditions. This determines whether the dosing module needs to be activated to add chemicals to the secondary sedimentation tank to increase the sludge settling rate. In this way, the operating load of the secondary sedimentation tank can be detected in real time based on its online operating parameters. Chemicals are only added when the operating load exceeds the critical load, reducing the amount of flocculant added and promoting an increase in the operating load of the wastewater treatment plant. The structure is simple, the cost is low, the operation is convenient, and the effect is stable. It improves the operating capacity of the wastewater treatment plant while reducing the amount of flocculant added, and has a very broad application prospect in wastewater treatment.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0018] Figure 1 This is a flowchart illustrating an operation control method for a wastewater treatment plant according to an exemplary embodiment.

[0019] Figure 2 This is a simplified process flow diagram of a wastewater treatment plant according to an exemplary embodiment.

[0020] Figure 3 This is a graph illustrating the change in solid flux in a secondary sedimentation tank according to an exemplary embodiment.

[0021] Figure 4 This is a graph illustrating the change in solid flux in a secondary sedimentation tank according to an exemplary embodiment.

[0022] Figure 5This is a logic block diagram illustrating an operation control method for a wastewater treatment plant according to an exemplary embodiment. Detailed Implementation

[0023] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0024] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0025] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0026] Figure 1 This is a flowchart illustrating an operation control method for a wastewater treatment plant according to an exemplary embodiment. Figure 2 This is a logic block diagram illustrating an operation control method for a wastewater treatment plant according to an exemplary embodiment. For example... Figure 1 and Figure 2 As shown, the strategy steps included in this operation control method can be set in the control system 100 of the wastewater treatment plant. For example, the control system 100 can be understood as a computer terminal configured in the wastewater treatment plant, or it can also be configured with a processor containing the following strategy steps. Of course, in addition to running the operation strategy in the following steps, the control system 100 can also synchronously control the influent pump 200, the biological treatment unit 300, the chemical dosing module 400, the effluent pump 500, and the secondary sedimentation tank 600. For example, this operation control method may include the following steps: In step 101, the functional relationship between the settling flux and sludge concentration of the secondary sedimentation tank is obtained.

[0027] In step 102, based on the functional relationship, the first solid flux value corresponding to the settling flux of the secondary sedimentation tank under the current sludge concentration condition is obtained.

[0028] In this embodiment, the functional relationship can be established based on measurement parameters before the execution of the operation control method. For example, the sludge concentration and sludge settling rate measurements in the secondary sedimentation tank can be obtained multiple times. Based on these sludge concentration and settling rate measurements, the initial settling rate constant and settling velocity decay constant in the sludge settling model can be calculated. For example, based on the following sludge settling model: ; in, This is a measurement of the sludge settling rate; The initial settlement rate constant; The settling velocity decay constant; This is the measured value of sludge concentration.

[0029] To improve the accuracy of the sludge settling model, sludge concentration and sludge settling rate measurements can be monitored for the target secondary settling tank, with the number of sludge concentration measurements being greater than or equal to 2 and the number of sludge settling rate measurements being greater than or equal to 2.

[0030] Furthermore, the functional relationship between settling flux and sludge concentration can be obtained based on the initial settling rate constant and the settling velocity decay constant. For example, , that is ,in, Let f be the settling flux. Therefore, based on this functional relationship, the first solids flux value corresponding to the settling flux at any sludge concentration in the secondary settling tank can be obtained.

[0031] In step 103, based on the changes in bottom flow rate and overflow flow rate, the second solids flux value is obtained when the intersection of the bottom flow rate and overflow flow rate is at the current sludge concentration condition.

[0032] In this embodiment, based on the input parameters for the control system 100, the changes in the bottom flow rate and overflow flow rate of the secondary sedimentation tank can be obtained first, and then the second solids flux value can be obtained when the intersection of the bottom flow rate and overflow flow rate is at the current sludge concentration condition. For example... Figure 2As shown, the input parameters can include influent flow rate, influent load, sludge concentration, dissolved oxygen, recirculation ratio, secondary sedimentation tank sludge level, and effluent parameters. Based on the influent flow rate and recirculation ratio, the underflow rate and overflow rate under the current sludge concentration condition can be obtained. Furthermore, using sludge concentration as the independent variable and solids flux as the dependent variable, the change in underflow rate is calculated based on the underflow rate, and the change in overflow rate is calculated based on the overflow rate. By changing the input parameters, the intersection of the changes in underflow rate and overflow rate corresponds to the current sludge concentration condition. For example... Figure 3 As shown, assuming the current sludge concentration is 8 g / L and the return ratio is approximately 50%, the x-axis represents sludge concentration and the y-axis represents solids flux. The upward line from left to right represents the change in bottom flow rate, and the downward line from left to right represents the change in overflow flow rate. By adjusting the input parameters, the x-axis of the intersection of the bottom flow rate line and the overflow flow rate line is constructed so that it is located near the current sludge concentration of 8 g / L. The influent flow rate, current sludge concentration, and return ratio can be detected by real-time monitoring sensors.

[0033] In step 104, when the second solid flux value is greater than the first solid flux value, the dosing module is controlled to start the dosing mode.

[0034] In this embodiment, under the current sludge concentration conditions, when the second solids flux value equals the first solids flux value, it indicates that the current operating load of the secondary sedimentation tank has reached the critical load. If the second solids flux value is greater than the first solids flux value, it indicates that the current operating load of the secondary sedimentation tank has exceeded the critical load, and there is a risk of sludge overflow. Therefore, for this current concentration condition, it is necessary to control the dosing module to start the dosing mode, thereby adding flocculants and other agents into the secondary sedimentation tank to increase the operating load of the secondary sedimentation tank and avoid the risk of sludge overflow. If the second solids flux value is less than the first solids flux value, it indicates that the current operating load of the secondary sedimentation tank is less than the critical load, and the secondary sedimentation tank can operate stably. The current sludge concentration condition can be the real-time sludge concentration in the secondary sedimentation tank, or it can be the sludge concentration of the sludge in the biological unit 300, which can be designed as needed.

[0035] For example, the dosing module can be used to add flocculants alone, or it can be used to add a mixture of coagulants and flocculants. Flocculants include cationic polyacrylamide, anionic polyacrylamide, nonionic polyacrylamide, composite flocculants, etc.

[0036] like Figure 3 As shown, assuming the current sludge concentration is 8 g / L and the recirculation ratio is approximately 50%, the x-axis represents sludge concentration and the y-axis represents solids flux. Figure 3The blue curve in the graph represents the functional relationship between the settling flux and sludge concentration in the secondary sedimentation tank. A straight line with a positive slope represents the bottom flow rate, and a straight line with a negative slope represents the overflow flow rate. Multiple overflow flow rate lines represent the overflow flow rate of the secondary sedimentation tank under different influent flow rates, and multiple bottom flow rate lines represent the bottom flow rate of the secondary sedimentation tank under different influent flow rates. (Comparison) Figure 3 As can be seen from the settling flux curve, overflow flux line, and bottom flux curve, at a sludge concentration of 8 g / L, the intersection of the overflow flux line and the bottom flux curve is located above the settling flux curve, indicating a risk of sludge runoff. Therefore, it is necessary to switch the dosing module to dosing mode.

[0037] like Figure 4 As shown, assuming the current sludge concentration is 4 g / L and the recirculation ratio is approximately 50%, the x-axis represents sludge concentration and the y-axis represents solids flux. Figure 4 The blue curve in the graph represents the functional relationship between the settling flux and sludge concentration in the secondary sedimentation tank. A straight line with a positive slope represents the bottom flow rate, and a straight line with a negative slope represents the overflow flow rate. Multiple overflow flow rate lines represent the overflow flow rate of the secondary sedimentation tank under different influent flow rates, and multiple bottom flow rate lines represent the bottom flow rate of the secondary sedimentation tank under different influent flow rates. (Comparison) Figure 4 As can be seen from the settling flux curve, overflow flux line, and bottom flux line, at a sludge concentration of 4 g / L, the intersection of the overflow flux line and the bottom flux line is located below the settling flux curve, indicating that the secondary sedimentation tank can operate stably without the need for flocculant addition.

[0038] Based on this, by comparing the second solids flux value with the first solids flux value under the current concentration conditions, it can be determined whether the operating load of the secondary sedimentation tank is exceeded. This allows for the determination of whether the dosing module needs to be activated to add chemicals to the secondary sedimentation tank to increase the sludge settling rate. In this way, the operating load of the secondary sedimentation tank can be monitored in real time based on its online operating parameters. Chemicals are only added when the operating load exceeds the critical load, reducing the amount of flocculant required and promoting increased operating load in the wastewater treatment plant. This method is simple in structure, low in cost, easy to operate, and has stable effects. It improves the operating capacity of the wastewater treatment plant while reducing flocculant dosage, and has a very broad application prospect in wastewater treatment.

[0039] In some embodiments, a functional relationship between the influent flow rate and the dosage of the flocculant can be obtained, and the dosage of the flocculant can be further obtained based on this functional relationship and the real-time influent flow rate. This functional relationship can be a mapping relationship pre-stored in the control system 100, which is called during subsequent operation to obtain the dosage of the flocculant corresponding to the real-time influent flow rate. This allows for convenient and quick determination of the dosage. Of course, the dosage required varies depending on the type of flocculant and the influent flow rate. Therefore, the type of flocculant can be determined first, and then the dosage can be obtained based on the mapping relationship between the type of flocculant and the influent flow rate.

[0040] For example, such as Figure 5 As shown, the dosing module may include a frequency converter, a dosing pump, and a storage tank. The dosing pump is connected to the storage tank and the secondary sedimentation tank via a chemical pipeline. The dosing pump is electrically connected to the frequency converter, and the frequency converter is electrically connected to the control system 100. After the control system 100 determines the dosage of the chemical based on a function relationship, it can send a control command to the frequency converter, which then controls the dosing pump to start and draw flocculant from the storage tank into the secondary sedimentation tank.

[0041] Throughout the entire operation cycle of the wastewater treatment plant, the dosage of the drug can be determined using the aforementioned functional relationship. In other embodiments, the dosage can also be obtained using the aforementioned functional relationship when the risk of sludge runoff first occurs after the start of the wastewater treatment plant's operation cycle. Subsequently, the dosage can be adjusted in a timely manner based on feedback parameters from the wastewater treatment plant, without relying on the functional relationship, thus improving the accuracy of the drug dosage.

[0042] For example, such as Figure 5 As shown, the first dosage can be obtained based on the suspended solids concentration in the secondary sedimentation tank effluent and a set threshold; the second dosage can be obtained based on the inflow rate of the secondary sedimentation tank and the inflow rate of the previous control cycle; and the third dosage can be obtained based on the suspended solids concentration in the secondary sedimentation tank effluent and the total suspended solids effluent standard. Then, based on the first, second, and third dosages and the drug dosage of the previous control cycle, the drug dosage for the current control cycle is calculated. The drug dosage for the initial control cycle is obtained based on the aforementioned functional relationship and the real-time inflow rate.

[0043] Based on this, the dosage of the drug can be fed back based on real-time parameters during operation. This allows for a more accurate measurement of the actual drug requirements, reducing dosage errors and ensuring the operating load of the secondary sedimentation tank while mitigating the risk of overdosing. The duration of this control cycle can be determined based on actual commissioning, for example, it can be ten minutes. Within each control cycle, the control system 100 outputs this control signal to the frequency converter, and this signal remains constant throughout the control cycle.

[0044] For this dynamic adjustment process, the control system 100 may include a processing module 105, a total effluent suspended solids control module 106, a feedforward compensation module 107, and a feedback compensation module 108. The total effluent suspended solids control module 106, feedforward compensation module 107, and feedback compensation module 108 are electrically connected to the processing module 105, and the processing module 105 is electrically connected to the frequency converter of the dosing module. The feedback compensation module 108 can obtain a first dosage based on the suspended solids concentration in the secondary sedimentation tank effluent and a set threshold. The feedforward compensation module 107 can obtain a second dosage based on the inflow rate of the secondary sedimentation tank and the inflow rate of the previous control cycle. The total effluent suspended solids control module 106 can obtain a third dosage based on the total effluent suspended solids concentration and the total suspended solids effluent standard. Subsequently, the processing module 105 obtains the drug dosage and converts it into a control signal, which is sent to the frequency converter to control the dosing pump for drug dosing.

[0045] In some embodiments, the feedback compensation module 108 can be configured to obtain the difference between the suspended solids concentration in the secondary sedimentation tank effluent and a set threshold within the current control cycle; according to Calculate the first dosage for the current control cycle. Wherein, This is the first dosage for the current control cycle; This is the difference between the suspended solids concentration in the secondary sedimentation tank effluent and the set threshold during the current control cycle. This is the difference between the concentration of suspended solids in the secondary sedimentation tank effluent and the set threshold value in the previous control cycle. is a constant coefficient. , The coefficient constant can determine the initial value, for example, . 0.15 The value is 0.1, and can be adjusted based on the actual situation. and The value, for example, can be further determined as... 0.2 The value is 0.06, and the threshold can be set to, for example, 15 mg / L.

[0046] Among them, such as Figure 5 As shown, the concentration of suspended solids in the effluent from the secondary sedimentation tank can be monitored in real time by sensors installed in the secondary sedimentation tank. Within one control cycle, the sensors can upload effluent suspended solids concentration monitoring data to the feedback compensation module 108 multiple times. Subsequently, the feedback compensation module 108 calculates the effluent suspended solids concentration in the current control cycle based on the multiple effluent suspended solids concentration monitoring data.

[0047] In some embodiments, the feedforward compensation module 107 can calculate the rate of change of the inflow rate based on the inflow rate of the previous control cycle and the inflow rate of the current control cycle; when the absolute value of the rate of change is less than or equal to the set rate of change, the second dosage is 0; when the absolute value of the rate of change is greater than the set rate of change, according to... Calculate the second dosage; wherein, This is the second dosage for the current control cycle; This represents the rate of change of inflow rate during the current control cycle. This refers to the drug dosage in the previous control period.

[0048] Among them, the rate of change ,in, This refers to the inflow rate of the previous control cycle. This refers to the inflow rate for the current control cycle. Considering the fluctuations in inflow rate within the same control cycle, the average inflow rate over the control cycle can be used as the inflow rate for that control cycle. The specific value of this inflow rate can be monitored by sensors. The rate of change can be initially determined and then adjusted based on on-site testing. For example, this rate of change could be set to 20%. This means that when the inflow rate in the current control cycle is less than the inflow rate in the previous control cycle, the rate of change... Since the result is a negative number, the calculated second dosage is also negative. This can be understood as reducing the dosage of the second dosage based on the dosage of the previous control cycle.

[0049] In some embodiments, the total effluent suspended solids control module 106 calculates a safety margin based on the total effluent suspended solids concentration and the total suspended solids effluent standard of the wastewater treatment system during the current control cycle; and further calculates the third dosage according to the following formula; ; ; in, For safety margin, and greater than 0; The total suspended solids effluent standard; This represents the total suspended solids concentration in the effluent during the current control cycle. This is the third dosage within the current control cycle; Set a value for the safety margin.

[0050] Among them, setting a threshold The concentration can be set at 10 mg / L, with a safety margin of 4 mg / L. The initial value can be set to 0.1, and can be further determined to be 0.15 through on-site debugging and testing.

[0051] In the above embodiments, this operation control method can also be applied to the entire process of wastewater treatment. For example, the effluent ammonia nitrogen concentration can be obtained, and when the effluent ammonia nitrogen concentration exceeds a critical value, the aeration rate of the aeration device in the biological unit can be increased, thereby improving the ammonia oxidation rate of the biological unit. As another example, the effluent total nitrogen concentration can be obtained, and when the effluent total nitrogen concentration exceeds a critical value, the carbon source dosage in the biological unit can be increased to reduce the effluent total nitrogen concentration and ensure the orderly operation of the system. As yet another example, the effluent total phosphorus concentration can be obtained, and when the effluent total phosphorus concentration exceeds a critical value, the dosage of phosphorus removal agent in the pipeline between the secondary sedimentation tank and the biological unit can be increased.

[0052] The aforementioned effluent ammonia nitrogen concentration, effluent total nitrogen concentration, and effluent total phosphorus concentration can be monitored by a feedforward monitoring module configured in the wastewater treatment plant. Furthermore, this feedforward monitoring module can also monitor the sludge level and suspended solids concentration in the secondary sedimentation tank in real time. For example, when the sludge level in the secondary sedimentation tank reaches the critical value, the influent and effluent will be stopped. Or, when the sludge level in the secondary sedimentation tank is below the critical value, the influent and effluent will be resumed to ensure the normal operation of the wastewater treatment plant.

[0053] Accordingly, this disclosure also provides an operation control system for a wastewater treatment plant, including a feedforward monitoring module, a dosing module, and a treatment module. The treatment module is electrically connected to both the dosing module and the feedforward monitoring module. The treatment module can be used to obtain the functional relationship between the settling flux and sludge concentration of the secondary sedimentation tank; obtain the first solids flux value corresponding to the intersection of the bottom flow rate and the overflow flow rate of the secondary sedimentation tank under the current sludge concentration condition; obtain the second solids flux value corresponding to the settling flux under the current sludge concentration condition according to the functional relationship; and control the dosing module to start the dosing mode when the first solids flux value is greater than the second solids flux value.

[0054] Accordingly, this disclosure also provides a terminal, the terminal including a memory and one or more programs, wherein one or more programs are stored in the memory and configured to be executed by one or more processors. The one or more programs include instructions for performing the following operations: obtaining a functional relationship between the settling flux and sludge concentration of the secondary sedimentation tank; obtaining a first solids flux value corresponding to the intersection of the bottom flow rate and the overflow flow rate of the secondary sedimentation tank under the current sludge concentration condition; obtaining a second solids flux value corresponding to the settling flux under the current sludge concentration condition according to the functional relationship; and controlling the dosing module to start the dosing mode when the first solids flux value is greater than the second solids flux value.

[0055] In an exemplary embodiment, a computer-readable storage medium is also provided having computer instructions stored thereon that, when executed by a processor, implement the steps of the method described in any of the foregoing embodiments. For example, the computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, or optical data storage device, etc.

[0056] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0057] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for operating and controlling a wastewater treatment plant, characterized in that, The operation control method, applied to wastewater treatment systems, includes: Obtain the functional relationship between the settling flux and sludge concentration in the secondary sedimentation tank; Based on the aforementioned functional relationship, obtain the first solids flux value corresponding to the sedimentation flux of the secondary sedimentation tank under the current sludge concentration conditions. Based on the changes in bottom flow rate and overflow flow rate, obtain the second solids flux value when the intersection of the bottom flow rate and overflow flow rate is at the current sludge concentration condition; When the second solid flux value is greater than the first solid flux value, the dosing module is controlled to start the dosing mode.

2. The operation control method according to claim 1, characterized in that, The process of obtaining the functional relationship between the settling flux and sludge concentration in the secondary sedimentation tank includes: Obtain the sludge concentration and sludge settling rate measurements in the secondary sedimentation tank, and calculate the initial settling rate constant and settling velocity decay constant in the sludge settling model. Based on the initial settling rate constant and the settling velocity decay constant, the functional relationship between settling flux and sludge concentration is obtained.

3. The operation control method according to claim 1, characterized in that, Based on the changes in bottom flow rate and overflow flow rate, obtain the second solids flux value when the intersection of the bottom flow rate and overflow flow rate is at the current sludge concentration condition, including: Obtain the inflow rate and return ratio; Based on the inflow rate and the return ratio, the bottom flow rate and overflow rate of the secondary sedimentation tank under the current sludge concentration conditions are obtained; Using sludge concentration as the independent variable and solids flux as the dependent variable, the change in bottom flow rate is obtained based on the bottom flow rate, and the change in overflow flow rate is obtained based on the overflow rate, such that the intersection of the changes in bottom flow rate and overflow flow rate corresponds to the current sludge concentration condition.

4. The operation control method according to claim 1, characterized in that, Also includes: Obtain the functional relationship between inflow rate and drug dosage; The dosage of the drug is obtained based on the aforementioned functional relationship and the real-time inflow water flow.

5. The operation control method according to claim 4, characterized in that, Also includes: The first dosage is obtained based on the suspended solids concentration in the effluent from the secondary sedimentation tank and the first set threshold. The second dosage is obtained based on the inflow rate of the secondary sedimentation tank and the inflow rate of the previous control cycle. The third dosage is obtained based on the total effluent suspended solids concentration and the total suspended solids effluent standard of the wastewater treatment system. The dosage for the current control cycle is calculated based on the first, second, and third dosages, as well as the dosage for the previous control cycle. The dosage for the initial control cycle is obtained based on the aforementioned functional relationship and the real-time inflow water flow.

6. The operation control method according to claim 5, characterized in that, The process of obtaining the first dosage based on the suspended solids concentration in the secondary sedimentation tank effluent and a set threshold includes: Obtain the difference between the suspended solids concentration in the effluent of the secondary sedimentation tank and the set threshold within the current control cycle; according to Calculate the first dosage for the current control cycle; in, This is the first dosage for the current control cycle; This is the difference between the suspended solids concentration in the secondary sedimentation tank effluent and the set threshold during the current control cycle. This is the difference between the concentration of suspended solids in the secondary sedimentation tank effluent and the set threshold value in the previous control cycle. is a constant coefficient.

7. The operation control method according to claim 5, characterized in that, The step of obtaining the second dosage based on the inflow rate of the secondary sedimentation tank and the inflow rate of the previous control cycle includes: Calculate the rate of change of the inflow rate based on the inflow rate of the previous control cycle and the inflow rate of the current control cycle. When the absolute value of the rate of change is less than or equal to the set rate of change, the second dosage is 0; When the absolute value of the rate of change is greater than the set rate of change, according to Calculate the second dosage; in, This is the second dosage for the current control cycle; This represents the rate of change of inflow rate during the current control cycle. This refers to the drug dosage in the previous control period.

8. The operation control method according to claim 5, characterized in that, Based on the total effluent suspended solids concentration and the total suspended solids effluent standard of the wastewater treatment system, the third dosage is obtained, including: Calculate the safety margin based on the total suspended solids concentration in the effluent and the total suspended solids effluent standard during the current control cycle; Calculate the third dosage using the following formula; ； ； in, For safety margin, and greater than 0; The total suspended solids effluent standard; This represents the total suspended solids concentration in the effluent during the current control cycle. This is the third dosage within the current control cycle; Set a value for the safety margin; This refers to the drug dosage in the previous control period; is a constant coefficient.

9. The operation control method according to claim 1, characterized in that, It also includes at least one of the following: When the effluent ammonia nitrogen concentration is obtained and exceeds the critical value, the aeration rate of the aeration device in the biological unit is increased. Obtain the total nitrogen concentration in the effluent, and when the total nitrogen concentration in the effluent exceeds the critical value of nitrogen concentration, control the amount of carbon source added by the biochemical unit. Obtain the total phosphorus concentration in the effluent, and when the total phosphorus concentration in the effluent exceeds the critical value for phosphorus concentration, increase the dosage of phosphorus removal agent in the pipeline between the secondary sedimentation tank and the biological treatment unit.

10. An operation control system for a wastewater treatment plant, characterized in that, include: Feedforward monitoring module; Dosing module; The processing module is electrically connected to the dosing module and the feedforward monitoring module, respectively. The processing module is used to obtain the functional relationship between the settling flux and sludge concentration of the secondary sedimentation tank; according to the functional relationship, obtain the first solids flux value corresponding to the settling flux of the secondary sedimentation tank under the current sludge concentration condition; according to the changes in bottom flow rate and overflow flow rate, obtain the second solids flux value when the intersection of the bottom flow rate and overflow flow rate is at the current sludge concentration condition; when the first solids flux value is greater than the second solids flux value, control the dosing module to start the dosing mode.

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