A system for precise chemical phosphorus removal dosing based on multi-point dosing and multi-point feedback

Abstract

The application provides a system for precise chemical phosphorus removal dosing based on multi-point feedback, which comprises the following modules: a detection module, a dosing logic operation module and a dosing control module. 3‑ The system calculates the middle section dosing amount based on the ratio of the total phosphorus concentration value set in the last section to the total phosphorus concentration value detected in the middle section and the water quantity detection value; calculates the last section dosing amount based on the ratio of the total phosphorus concentration value set in the effluent to the total phosphorus concentration value detected in the last section and the water quantity detection value; analyzes whether the biological phosphorus removal is seriously inhibited by detecting the pH and the Δn(PO4 3‑ ) value to assist in controlling the dosing amount, so as to maintain the stability of the whole system operation; the dosing logic operation module is electrically connected with the detection module and the dosing control module.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of sewage treatment, and particularly relates to a system for precise dosing of chemical phosphorus removal based on multi-point dosing and multi-point feedback. BACKGROUND

[0002] At present, with the rapid development of China's economy, the urbanization process is accelerating, and the quality of people's life is gradually improving, which leads to more and more discharge of urban sewage, and the problem of water eutrophication caused by excessive content of nitrogen and phosphorus is particularly prominent, which seriously endangers the water environment and human health. The main method of nitrogen and phosphorus removal in urban sewage treatment plant is biological method, and the traditional nitrification and denitrification technology is widely used, but this method needs to consume a large amount of carbon source, and the urban sewage has the characteristics of low carbon-nitrogen ratio, so the removal effect of nitrogen and phosphorus is not good.

[0003] The main ways of phosphorus removal are chemical phosphorus removal and biological phosphorus removal, among which biological phosphorus removal is unstable and easily affected by many factors such as temperature and residence time, and the effect is poor, while chemical phosphorus removal is relatively stable and has good effect. Chemical phosphorus removal mainly adds inorganic metal salt reagent to domestic sewage to react with phosphate to generate non-soluble substances, and the metal salt has chemical flocculation effect, and the flocculation body is removed by sedimentation or filtration to achieve the effect of phosphorus removal.

[0004] In the prior art, the process of implementing chemical phosphorus removal method is to add chemical reagent into sewage at a fixed time and quantity. In the implementation process, when the concentration of the influent fluctuates greatly, the above method of adding chemical reagent at a fixed time and quantity has a large dosage, and cannot automatically change the dosage when the influent condition changes, so the phosphorus removal effect needs to be improved.

[0005] In view of the above problems, the present application provides a system for precise dosing of chemical phosphorus removal based on multi-point dosing and multi-point feedback, which can adjust the dosage of chemical phosphorus removal reagent in time according to different water quality conditions, optimize the dosage of reagent, and feedback the total phosphorus concentration at multiple places, so as to stabilize the total phosphorus concentration of effluent to reach the discharge standard and save the consumption of reagent. SUMMARY

[0006] In view of the above defects of the prior art, the present application aims to provide a system for precise dosing of chemical phosphorus removal based on multi-point dosing and multi-point feedback, which can automatically adjust the dosage when the water quality changes, achieve relatively fine and flexible dosing, timely and accurately respond to the changes of water quality and quantity, and thus achieve the goal of reducing the dosage of reagent.

[0007] A system for precise dosing of chemical phosphorus removal based on multi-point dosing and multi-point feedback is used for adding chemical reagent to a phosphorus removal biochemical tank, wherein the phosphorus removal biochemical tank comprises an influent position, a middle section of the phosphorus removal biochemical tank, a tail section of the phosphorus removal biochemical tank and an effluent position.

[0008] The system comprises the following modules: a detection module, a dosing logic operation module, and a dosing control module; the dosing logic operation module is in signal connection with the detection module and the dosing control module;

[0009] The detection module of the system comprises: an inlet water total phosphorus detection module, an inlet water orthophosphate detection module, and a water quantity detection module arranged at the inlet water, for detecting the total phosphorus concentration value, the orthophosphate concentration value, and the water quantity detection value at the inlet water, respectively; a middle section total phosphorus detection module arranged at the middle section of the phosphorus removal biochemical pool, for detecting the total phosphorus concentration value at the middle section of the phosphorus removal biochemical pool; a terminal section pH detection module and a terminal section total phosphorus detection module arranged at the terminal section of the phosphorus removal biochemical pool, for detecting the pH value and the total phosphorus concentration value at the terminal section of the phosphorus removal biochemical pool, respectively; and an outlet water total phosphorus detection module arranged at the outlet water, for detecting the total phosphorus concentration value at the outlet water;

[0010] The dosing logic module comprises an industrial calculator and a PLC with logic operation functions; the dosing logic module calculates the middle section dosing amount based on the ratio of the total phosphorus concentration value set at the terminal section of the phosphorus removal biochemical pool to the total phosphorus concentration value detected at the middle section and the water quantity detection value; the dosing logic module calculates the terminal section dosing amount based on the ratio of the total phosphorus concentration value set at the outlet water to the total phosphorus concentration value detected at the terminal section and the water quantity detection value; the dosing logic module sends the calculated middle section dosing amount to the middle section phosphorus removal dosing control module and sends the terminal section dosing amount to the terminal section phosphorus removal dosing control module; the system analyzes whether the biological phosphorus removal is severely inhibited by detecting the pH value and the △n(PO4 3- ) value to assist in controlling the dosing amount;

[0011] The dosing control module comprises a middle section phosphorus removal dosing control module arranged at the middle section of the phosphorus removal biochemical pool and a terminal section phosphorus removal dosing control module arranged at the terminal section of the phosphorus removal biochemical pool, both of which comprise a dosing pump for outputting a corresponding amount of dosing agent under the control of the dosing logic module.

[0012] Preferably, the detection module in the system further comprises:

[0013] An inlet water potassium ion detection module comprising a potassium ion detector arranged at the inlet of the phosphorus removal biochemical pool;

[0014] A middle section potassium ion detection module comprising a potassium ion detector arranged at the middle section of the phosphorus removal biochemical pool and before the middle section total phosphorus detection module;

[0015] A terminal section potassium ion detection module comprising a potassium ion detector arranged at the terminal section of the phosphorus removal biochemical pool and before the terminal section total phosphorus detection module.

[0016] Further, the dosing logic operation module comprises a first comparison module, a second comparison module, a third comparison module, a fourth comparison module, a first calculation submodule, a second calculation submodule, a third calculation submodule, and a first learning module.

[0017] The first comparison submodule operates as follows: comparing the middle-stage total phosphorus detection data with the preset effluent total phosphorus target value, when the middle-stage total phosphorus data is lower than the effluent total phosphorus target value, calling the middle-stage phosphorus removal chemical dosing control module to output a dose of 0; when the middle-stage total phosphorus data is not lower than the effluent total phosphorus target value, calling the first calculation submodule to operate the CEPRM model to calculate the chemical dosing amount.

[0018] Further, the chemical dosing logic operation module further comprises a second comparison module, the second comparison submodule operates as follows: comparing the end-stage total phosphorus detection data with the preset effluent total phosphorus target value, when the end-stage total phosphorus data is lower than the effluent total phosphorus target value, then calling the end-stage phosphorus removal chemical dosing control module to output a dose of 0; when the end-stage total phosphorus data is not lower than the effluent total phosphorus target value, calling the second calculation submodule to operate the CEPRM model to calculate the chemical dosing amount.

[0019] Further, the chemical dosing logic operation module further comprises a third comparison module and a fourth comparison module.

[0020] The third comparison submodule operates as follows: comparing the received end-stage pH value detection data with the preset pH value, when the pH data is less than the preset pH value, calling the middle-stage phosphorus removal chemical dosing control module to reduce the original output dose by 1 mg / L each time, when the pH value is higher than the preset value, the accumulated reduction of the dosing amount is reset to zero for recalculation, after a period of operation, it is analyzed whether the pH value at the end of the phosphorus removal biochemical tank is higher than the preset value and can be stably maintained, the reduction of the dosing amount is reduced by an upper limit of 10 mg / L from the original output dose, when the reduction upper limit is reached, if the pH value is still higher than the preset value, the operation is maintained in this form and no further adjustment is made, and the subsequent adjustment is made for the end-stage dosing amount;

[0021] The fourth comparison submodule operates as follows: comparing the received effluent total phosphorus detection data with the preset effluent total phosphorus target value, when the effluent total phosphorus detection data is lower than the target value, no adjustment is made to the end-stage phosphorus removal chemical dosing control module; otherwise, the original dosing amount of the end-stage phosphorus removal chemical dosing control module is accumulated by 5 mg / L, and the process is repeated until the effluent total phosphorus is lower than the target value, and the accumulated value of the output dosing amount of the end-stage phosphorus removal chemical dosing control is reset to zero when the effluent total phosphorus is lower than the target value.

[0022] Further, the chemical dosing logic operation module further comprises a first calculation submodule and a second calculation submodule.

[0023] The first calculation submodule is used to receive the total phosphorus detection data and water volume detection data in the middle section of the phosphorus removal biochemical tank. Based on the ratio of the preset target value of total phosphorus in the final section to the total phosphorus concentration detection data in the middle section, when the ratio is within the range of 0-1, the dosage is calculated using the CEPRM model formula and the corresponding dosage of the agent is output by calling the middle section phosphorus removal dosing control module.

[0024] The second calculation submodule is used to receive the final stage total phosphorus detection data. Based on the ratio of the preset target value of total phosphorus in the effluent to the final stage total phosphorus concentration detection data, when the ratio is within the range of 0-1, the CEPRM model formula is used to calculate the dosage and the final stage phosphorus removal dosing control module is called to output the reagent.

[0025] Furthermore, the first and second calculation submodules establish an empirical model (CEPRM model) for precise dosage of chemically enhanced phosphorus removal. The model formula is based on an inverse proportional function and is as follows:

[0026]

[0027] Wherein, Y is the ratio of the residual phosphorus concentration in the water after dosing to the phosphorus concentration in the raw water before dosing;

[0028] X — the molar concentration of metal ions, mmol Mei+ / L;

[0029] b—Empirical constant, L / mmol;

[0030] a, c — dimensionless empirical constants.

[0031] When fitting the CEPRM model formula, a relatively high dosage was set so that its corresponding Y value was 0. The boundary conditions of the model were set as follows: when X = 0, Y = 1; when X ≥ 1, Y = 0. Y was the dependent variable, X was the independent variable, and the constants a, b, and C were fitted to obtain specific values. The model was nonlinearly fitted in the software based on the ODR algorithm (Orthogonal Distance Regression). After fitting, the dosage was calculated according to the fitted formula, and the mid-stage phosphorus removal dosing control module was called to adjust the dosage, with new data calculated and adjusted every five minutes.

[0032] Furthermore, the dosing logic operation module also includes a first learning submodule, comprising a data acquisition component, a learning calculation component, and an execution dosing component, used to train the calculation module to enhance the accuracy of chemical dosing; the learning calculation component is data-connected to the data acquisition component, used to receive n sets of corresponding total phosphorus detection data in the middle stage, total phosphorus detection data in the final stage, total phosphorus detection data in the effluent, water volume monitoring data, and actual dosing amount, and filter out m sets of data, input the m sets of data into the built-in reinforcement learning program for training, fit a more accurate CEPRM model formula, and output the latest calculated dosing amount based on the latest total phosphorus detection data in the middle stage, total phosphorus detection data in the final stage, total phosphorus detection data in the effluent, and water volume monitoring data; the execution dosing component is used to call the phosphorus removal dosing control module to output the chemical corresponding to the dosing amount.

[0033] Furthermore, the dosing logic module also includes a third calculation submodule, used to receive the detection data of influent orthophosphate, influent potassium ions, mid-stage potassium ions, and terminal-stage potassium ions, and calculate n(K) at the influent at this time. + ) / n(PO4 3- The value of ) is then determined based on the condition that the ratio remains constant, using n(K) + ) / n(PO4 3- )=△n(K + ) / △n(PO4 3- ) Calculate the middle and final segments Δn(PO4) 3- The change in concentration is expressed in Mg. 2+ / PO4 3- This method also applies; when △n(PO4) 3- If the change is less than the preset amount, it indicates that the biochemical phosphorus removal effect has been greatly inhibited. Therefore, the intermediate-stage phosphorus removal dosing control module is invoked to reduce the dosage by 1 mg / L from the original dosage, Δn(PO4). 3- When the change in concentration is continuously less than the preset change, the concentration decreases by 1 mg / L each time, with a limit of 10 mg / L. Once this limit is reached, no further adjustments are made. When Δn(PO4) 3- When the change in concentration is greater than the preset change, the cumulative reduction in dosage is reset to zero and recalculated without calling the mid-stage phosphorus removal dosing control module. A new calculation is performed every five minutes.

[0034] The operating mode of a multi-point dosing and multi-point feedback chemical phosphorus removal precision dosing system is as follows:

[0035] 1) The system receives total phosphorus detection data, orthophosphate detection data, potassium ion detection data, pH detection data, and water volume detection data at the inlet, middle section, end section, and outlet at regular intervals, and sends them to the dosing logic operation module for processing.

[0036] 2) The first comparison module in the dosing logic operation module determines whether to call the mid-section dephosphorization dosing module to output the dosage. If called, the first calculation submodule and the first learning submodule are used to complete the preliminary calculation of the dephosphorization agent dosage and the dephosphorization dosing module is called to complete the dosage adjustment.

[0037] 3) Call the third comparison submodule and the third calculation submodule in the dosing logic operation module, and compare the pH value to calculate Δn(PO4). 3- ) Calculate the change in concentration to determine whether the existing dosage of the intermediate phosphorus removal dosing module needs to be adjusted;

[0038] 4) Implement the second comparison submodule in the dosing logic operation module to determine whether to call the output dose of the terminal phosphorus removal dosing module. If it is determined that it needs to be called, use the second calculation submodule and the first learning submodule to complete the preliminary calculation of the phosphorus removal agent dosage and call the terminal phosphorus removal dosing module to adjust the dosage.

[0039] 5) Run the fourth comparison submodule in the dosing logic operation module to compare the total phosphorus in the effluent with the target value. If the total phosphorus in the effluent is greater than the target value, call the final stage phosphorus removal dosing module and adjust the existing dosage in the final stage; otherwise, do not call the final stage phosphorus removal dosing module.

[0040] 6) The total phosphorus concentration in the effluent should be controlled below the target value.

[0041] The beneficial effects of this invention are as follows:

[0042] (1) Based on the collection of a large amount of total phosphorus data in the middle and end sections of the phosphorus removal biochemical tank, the accuracy of the CEPRM model formula can be continuously optimized through data screening and reinforcement learning calculations, thereby reducing the changing trend of phosphorus removal agent dosage in the middle and end sections and maintaining the stability of chemical phosphorus removal effect. If further enhancement of phosphorus removal dosing effect is required, the dosage can be adjusted by the end section phosphorus dosing module to ensure that the total phosphorus in the system effluent meets the standard.

[0043] (2) Collect total phosphorus data, influent orthophosphate data, pH data of the last stage of the biological treatment tank, and potassium ion data of the middle and last stages of the system influent, middle stage, last stage and effluent. When the total phosphorus concentration or the pH of the last stage or the biological phosphorus removal effect at a certain point is abnormal, it can provide timely feedback and adjust the dosage of the reagent and analyze the problem. Because there are middle stage and last stage phosphorus removal dosing modules, the system will not crash due to a problem or major adjustment of one dosing module, and the system stability is higher. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention. Detailed Implementation

[0045] The embodiments of the present invention will be described in detail below. The embodiments described below are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the embodiments described below.

[0046] This embodiment is a chemical phosphorus removal precision dosing system based on multi-point dosing and multi-point feedback. It can quickly adjust the dosage of the agent according to changes in water quality, and the phosphorus removal effect of the whole system is more stable.

[0047] A system for precise chemical phosphorus removal based on multi-point dosing and multi-point feedback includes the following modules:

[0048] The influent total phosphorus detection module 1 can be a total phosphorus analyzer installed at the inlet of the biological treatment tank or the entire chemical phosphorus removal precision dosing system. This module is used to detect the water at the inlet, generate and output influent total phosphorus data, including the total phosphorus concentration of the influent, which can be expressed in mg / L. The detection frequency can be set to once every 5 minutes.

[0049] The influent orthophosphate detection module 2 can be equipped with an orthophosphate analyzer installed at the inlet of the biological treatment tank or the entire chemical phosphorus removal precision dosing system. This module is used to detect the water at the inlet, generate and output influent orthophosphate data, including the orthophosphate concentration in the influent, with the unit of concentration being mg / L, and can be set to detect every 5 minutes.

[0050] The influent potassium ion detection module 3 can be a potassium ion detector installed at the inlet of the biological treatment tank or the entire chemical phosphorus removal precision dosing system. This module is used to detect the water at the inlet, generate and output influent potassium ion data, including the concentration of potassium ions at the inlet, with the unit of concentration being mg / L, and can be set to detect once every 5 minutes.

[0051] The intermediate total phosphorus detection module 4 can be a total phosphorus analyzer installed a short distance before the phosphorus removal dosing module 10 in the aeration tank of the biological treatment tank. The installation distance can be 10m to 15m. The intermediate total phosphorus detection module 2 is used to detect the water in the middle section of the aeration tank of the biological treatment tank, generate and output the intermediate total phosphorus data, including the total phosphorus concentration in the middle section, which can be expressed in mg / L. The detection frequency can be set to once every 5 minutes.

[0052] The final pH detection module 5 can be a pH meter installed after the final total phosphorus detection module 7 at the end of the aeration tank in the biological treatment tank, at a distance of 2m to 3m. The final pH detection module 5 is used to detect the water at the end of the aeration tank in the biological treatment tank, generate and output the final pH data, and can be set to detect at a frequency of once every 5 minutes.

[0053] The intermediate potassium ion detection module 6 can be a potassium ion detector installed in the middle section of the aeration tank within the biological treatment tank, before the total phosphorus detection module 4, at a distance of 3m to 5m from the intermediate total phosphorus detection module. This module is used to detect the water in the middle section of the aeration tank within the biological treatment tank, generating and outputting intermediate potassium ion data. The intermediate potassium ion data includes the potassium ion concentration of the water in the middle section, with the unit of concentration being mg / L. The detection frequency can be set to once every 5 minutes.

[0054] The final stage total phosphorus detection module 7 can be a total phosphorus analyzer installed a short distance before the phosphorus removal dosing module 11 at the end of the aeration tank in the biological treatment tank. The installation distance can be 10m to 15m. It is used to detect the water at the end of the biological treatment tank, generate and output the final stage total phosphorus data, including the final stage total phosphorus concentration, which can be expressed in mg / L. The detection frequency can be set to once every 5 minutes.

[0055] The terminal potassium ion detection module 8 can be a potassium ion detector installed at the end of the biological treatment tank, before the terminal total phosphorus detection module 7, at a distance of 3m to 5m. This module is used to detect the water at the end of the biological treatment tank, generate and output terminal potassium ion data, including the potassium ion concentration of the water at the end of the tank, with the unit of concentration being mg / L, and can be set to detect once every 5 minutes.

[0056] The effluent total phosphorus detection module 9 is installed at the effluent outlet of the entire chemical phosphorus removal precision dosing system. It is used to detect the water at the effluent outlet, generate and output effluent total phosphorus data, including the total phosphorus concentration in the effluent, which can be expressed in mg / L. It can be detected once every 5 minutes.

[0057] The intermediate and final phosphorus removal dosing modules 10 and 11 can be equipped with dosing pumps and installed in the dosing room. They can receive external control information and output the corresponding values ​​of the agent in the control information. The agent can be prepared according to the on-site use or used directly. The agent is added to the intermediate section of the aeration tank and the final section of the biological treatment tank, respectively. The dosing amount is adjusted every 5 minutes.

[0058] The water volume detection module 12 can be set at the inlet or outlet of the entire chemical phosphorus removal precision dosing system to detect the water volume passing through the phosphorus removal unit and output the water volume. They are detected at a frequency of once every 5 minutes.

[0059] The dosing logic operation module 13 can be an industrial calculator, PLC or other device with logic operation function, to receive relevant data and perform operations in each sub-module to control the amount of drug added.

[0060] The dosing logic module 13 is connected to the following modules: influent total phosphorus detection module 1, influent orthophosphate detection module 2, influent potassium ion detection module 3, intermediate total phosphorus detection module 4, intermediate and final pH detection module 5, intermediate potassium ion detection module 6, final total phosphorus detection module 7, final potassium ion detection module 8, effluent total phosphorus detection module 9, intermediate phosphorus dosing control module 10, final phosphorus dosing control module 11, and water volume detection module 12. The dosing logic module 13 can receive the treated water volume, intermediate total phosphorus data, final total phosphorus data, and effluent total phosphorus data through the communication bus. It can also send corresponding control information to the intermediate phosphorus dosing control module 10 and the final phosphorus dosing control module 11 through the communication bus.

[0061] The dosing logic operation module 13 receives the treated water volume, intermediate total phosphorus data, terminal total phosphorus data, and effluent total phosphorus data. It then performs its first comparison submodule to compare the intermediate total phosphorus in the aeration tank with the target value of the effluent total phosphorus. If the difference is greater, its first calculation submodule calculates the dosage of the chemical based on the ratio of the terminal total phosphorus concentration (around 0.2 mg / L) to the intermediate total phosphorus concentration. The module then calls the intermediate phosphorus removal dosing module 10. Simultaneously, the module uses a reinforcement learning program to continuously collect such data and further optimize the fitted CEPRM model formula to improve accuracy. This optimized formula is used to calculate the dosage of the chemical in subsequent optimizations of the intermediate phosphorus removal chemical. Conversely, when the intermediate total phosphorus in the aeration tank is less than the target value of the effluent total phosphorus, the intermediate phosphorus removal dosing module 10 outputs a dosage of 0.

[0062] After completing the first comparison submodule and the first calculation submodule, the third comparison submodule and the third calculation submodule are run. The third comparison submodule is used to receive the final pH value. If the pH is less than the preset pH value (set to 6.70-6.80), the mid-stage phosphorus removal dosing control module 10 is invoked to cumulatively reduce the dosage by 1 mg / L each time from the original output dose. When the pH value is higher than the preset value, the cumulative reduction in dosage is reset to zero and recalculated. The upper limit of the dosage reduction from the original output dose is 10 mg / L. If the pH value is still not stable above the preset value when the upper limit is reached, this mode of operation is maintained, and no further adjustments are made here. The final dosing dosage will be adjusted subsequently.

[0063] The third calculation submodule is used to calculate n(K) at the water inlet at this time. + ) / n(PO4 3- The value of ) is then used to calculate the middle and final segments Δn(PO4) based on the assumption that this value remains unchanged. 3- If the change in concentration is less than a preset change, the intermediate phosphorus removal dosing control module 10 will be invoked to reduce the original dosage by 1 mg / L, Δn(PO4). 3- When the change in concentration is continuously less than the preset change, the concentration decreases by 1 mg / L each time, with a limit of 10 mg / L. Once this limit is reached, no further adjustments are made. When Δn(PO4) 3- When the change in concentration is greater than the preset change, the cumulative reduction in dosage is reset to zero and recalculated, and the mid-stage phosphorus removal dosing control module 10 is not invoked.

[0064] After completing the third comparison submodule and the third calculation submodule, the second comparison submodule is run to compare the final total phosphorus value with the target total phosphorus value in the effluent. If the target value is greater, the second calculation submodule is used, based on the ratio of the total phosphorus concentration set in the effluent (approximately 0.15 mg / L) to the total phosphorus concentration detected at the end. When the ratio is ≥1, the final dosage is calculated as 0. When 0 < ratio < 1, this ratio and the water volume detection data are used to calculate the final dosage. The dosage is calculated according to this fitted formula, and the final phosphorus removal dosing control module 11 is called to adjust the dosage. The calculation and adjustment are performed every five minutes based on new data. The first learning submodule continuously collects such data using a reinforcement learning program and further optimizes the fitted CEPRM model formula to calculate the dosage for subsequent autonomous adjustment of the phosphorus removal dosage. Conversely, when the final total phosphorus and effluent total phosphorus data are less than the target total phosphorus value in the effluent, the final phosphorus removal dosing module 11 is called to output a dosage of 0.

[0065] The fourth comparison submodule is run to compare the total phosphorus data in the effluent with the target value (0.15 mg / L). If the total phosphorus in the effluent is less than the target value (0.15 mg / L), the final phosphorus removal dosing control module 11 is not adjusted. Otherwise, the final phosphorus removal dosing control module 11 is called to increase the dosage by 5 mg / L each time, and this process is repeated until the total phosphorus in the effluent is lower than the target value. When the total phosphorus in the effluent is lower than the target value (0.15 mg / L), the cumulative value of the dosing output of the final phosphorus removal dosing control module 11 is reset to zero.

[0066] The learning calculation component in the first learning submodule of the dosing logic operation module 13 can be implemented by embedding a simple reinforcement learning program into the microcontroller. The dosing execution component is used to call the phosphorus dosing control modules 10 and 11 to output the corresponding dosage of the chemicals. The data acquisition component can collect data on the dosage from on-site personnel or data generated by automatic chemical dosing. After accumulating a certain amount of data, it is filtered and then trained. After training, the learning calculation component can automatically output the dosage. As time goes by and a large amount of data is collected, the learning calculation component will calculate the optimal dosage to ensure that the effluent reaches a reasonable range. The first learning submodule continues to optimize the formula and dosage through the feedback of total phosphorus data in the middle stage, total phosphorus data in the final stage, total phosphorus data in the effluent, and water volume data. This cycle continues to optimize the learning calculation component, making the system most reasonable or most suitable for the current operating conditions.

[0067] The operating mode of a multi-point dosing and multi-point feedback chemical phosphorus removal precision dosing system:

[0068] Step 1: The system receives total phosphorus detection data, orthophosphate data at the inlet, middle section, terminal section, and outlet every 5 minutes, potassium ion data, pH data at the terminal section, and water volume detection data, and transmits them to the dosing logic operation module 13.

[0069] Step 2: Through the first step in the dosing logic operation module 13, determine whether to call the mid-section phosphorus removal dosing module 10 to output the dosage. If called, use the first step and the first learning sub-module to complete the preliminary calculation of the phosphorus removal agent dosage and call the phosphorus removal dosing module 10 to complete the dosage adjustment.

[0070] Step 3: Perform the third comparison submodule and the third calculation submodule in the dosing logic operation module 13. By comparing the pH value, Δn(PO4) 3- The calculation of the change in concentration determines whether the existing dosage of the intermediate phosphorus removal dosing module 10 needs to be adjusted.

[0071] Step 4: Implement the second comparison submodule in the dosing logic operation module 13 to determine whether to call the terminal phosphorus removal dosing module 11 to output the dosage. If it is determined that it needs to be called, use the second calculation submodule and the first learning submodule to complete the preliminary calculation of the phosphorus removal agent dosage and call the terminal phosphorus removal dosing module 11 to adjust the dosage.

[0072] Step 5: Run the fourth comparison submodule in the dosing logic operation module 13 to compare the total phosphorus in the effluent with the target value. If the total phosphorus in the effluent is greater than the target value, call the final stage phosphorus removal dosing module 11 and adjust the existing dosage in the final stage; otherwise, do not call the final stage phosphorus removal dosing module 11.

[0073] Step 6: Control the total phosphorus concentration in the effluent to below the target value.

[0074] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A system for precise chemical phosphorus removal dosing based on multi-point dosing and multi-point feedback, used to add chemical agents to a phosphorus removal biological treatment tank, wherein the phosphorus removal biological treatment tank includes an inlet, a middle section, a terminal section, and an outlet; characterized in that, It includes the following modules: detection module, dosing logic operation module, and dosing control module; The dosing logic operation module is connected to both the detection module and the dosing control module via signals. The detection module includes: an influent total phosphorus detection module, an influent orthophosphate detection module, and a water volume detection module installed at the influent, used to detect the total phosphorus concentration, orthophosphate concentration, and water volume at the influent, respectively; a mid-section total phosphorus detection module installed in the middle section of the phosphorus removal biological treatment tank, used to detect the total phosphorus concentration at the middle section of the phosphorus removal biological treatment tank; a terminal pH detection module and a terminal total phosphorus detection module installed at the end of the phosphorus removal biological treatment tank, used to detect the pH value and total phosphorus concentration at the end of the phosphorus removal biological treatment tank, respectively; and an effluent total phosphorus detection module installed at the effluent, used to detect the total phosphorus concentration at the effluent. The dosing logic module includes an industrial calculator and a PLC with logic operation functions. The module calculates the mid-stage chemical dosage based on the ratio of the total phosphorus concentration set at the end of the phosphorus removal biological treatment tank to the total phosphorus concentration detected in the mid-stage, along with the water flow rate. It also calculates the final-stage chemical dosage based on the ratio of the total phosphorus concentration set in the effluent to the total phosphorus concentration detected at the end of the treatment tank, along with the water flow rate. The module sends the calculated mid-stage chemical dosage to the mid-stage phosphorus removal dosing control module and the final-stage chemical dosage to the final-stage phosphorus removal dosing control module. The system detects pH and Δn (PO4). 3- Value analysis can help determine whether biological phosphorus removal is severely inhibited, thus aiding in the control of pesticide dosage. The dosing control module includes a mid-section phosphorus removal dosing control module located in the middle section of the phosphorus removal biochemical tank and a terminal phosphorus removal dosing control module located at the end of the phosphorus removal biochemical tank. Both modules include a dosing pump, which receives control information from the dosing logic operation module to output corresponding values ​​of the reagent. The dosing logic operation module includes a first comparison module, which operates as follows: the intermediate total phosphorus data is compared with a preset effluent total phosphorus target value; when the intermediate total phosphorus data is lower than the effluent total phosphorus target value, the intermediate phosphorus removal dosing control module is invoked to output a dosage of 0; when the intermediate total phosphorus data is not lower than the effluent total phosphorus target value, the first calculation submodule is invoked to run the CEPRM model to calculate the dosage of the dosing agent. The dosing logic operation module also includes a second comparison submodule. The second comparison submodule operates as follows: it compares the final total phosphorus data with the preset effluent total phosphorus target value. When the final total phosphorus data is lower than the effluent total phosphorus target value, it calls the final phosphorus removal dosing control module to output a dosage of 0. When the final total phosphorus data is not lower than the effluent total phosphorus target value, it calls the second calculation submodule to run the CEPRM model to calculate the dosage of the agent. The dosing logic operation module also includes a third comparison submodule and a fourth comparison submodule. The third comparison submodule operates as follows: it compares the received final pH value data with the preset pH value. When the pH value data is less than the preset pH value, it calls the mid-stage phosphorus removal dosing control module to reduce the original output dose by 1 mg / L each time. When the pH value data is higher than the preset pH value, the cumulative reduction in dosage is zeroed. The maximum reduction in dosage from the original output dose is 10 mg / L. The fourth comparison submodule operates as follows: it compares the received effluent total phosphorus data with the preset effluent total phosphorus target value. When the effluent total phosphorus data is lower than the target value, no adjustment is made to the final stage phosphorus removal dosing control module; otherwise, the original dosage of the final stage phosphorus removal dosing control module is increased by 5 mg / L until the effluent total phosphorus is lower than the target value, at which point the accumulated value of the final stage phosphorus removal dosing control output dosage is reset to zero. The dosing logic operation module further includes a first calculation submodule and a second calculation submodule; the first calculation submodule is used to receive the total phosphorus data and water volume data of the middle section of the phosphorus removal biochemical tank, calculate the dosage according to the CEPRM model formula based on the command of the first comparison module, and call the middle section phosphorus removal dosing control module to output the reagent; The second calculation submodule is used to receive the final stage total phosphorus data, calculate the dosage according to the CEPRM model formula based on the command of the second comparison module, and call the final stage phosphorus removal dosing control module to output the reagent; The first and second calculation submodules use an empirical model—the CEPRM model—to establish precise dosage for chemically enhanced phosphorus removal. The CEPRM model is based on an inverse proportional function, and the formula is as follows: Wherein, Y is the ratio of the residual phosphorus concentration in the water after dosing to the phosphorus concentration in the raw water before dosing; X — Molar concentration of metal ions, mmol / M + / L; b—Empirical constant, L / mmol; a, c — dimensionless empirical constants; When fitting the CEPRM model formula, a relatively high dosage is set so that its corresponding Y value is 0. Based on this model, the boundary conditions are set as follows: when X=0, Y=1; when X≥1, Y=0; fit Y as the dependent variable and X as the independent variable, and the constants a, b, and C can be fitted to obtain specific values. The model is based on the ODR algorithm and performs nonlinear fitting in the software. When the fitting is complete, the dosage is calculated according to the fitting formula and the mid-stage phosphorus removal dosing control module is called to adjust the dosage. The new data is calculated and adjusted every five minutes.

2. The system for precise chemical phosphorus removal based on multi-point dosing and multi-point feedback as described in claim 1, characterized in that, The detection module also includes: The influent potassium ion detection module, including a potassium ion detector, is installed at the inlet of the phosphorus removal biological treatment tank. The mid-section potassium ion detection module, including a potassium ion detector, is located in the middle section of the phosphorus removal biochemical tank and before the mid-section total phosphorus detection module; The final potassium ion detection module, including a potassium ion detector, is located at the end of the phosphorus removal biochemical tank and before the final total phosphorus detection module.

3. The system for precise chemical phosphorus removal based on multi-point dosing and multi-point feedback as described in claim 1, characterized in that, The dosing logic module further includes a third calculation submodule, which is used to receive the detection data of influent orthophosphate, influent potassium ions, mid-stage potassium ions, and terminal potassium ions, and calculate n(K) at the influent. + ) / n(PO4) 3- The value of ) is then determined based on the condition that the ratio remains constant, using n(K) + ) / n(PO4) 3- ) = △n (K + ) / △n(PO4 3- ) Calculate the middle and final segments Δn (PO4) 3- The change in concentration; when Δn(PO4) 3- If the change is less than the preset amount, the intermediate phosphorus removal dosing control module will be invoked to reduce the original dosage by 1 mg / L, Δn(PO4). 3- When the change in concentration is continuously less than the preset change, the cumulative decrease is 1 mg / L each time, with a limit of 10 mg / L; when Δn(PO4) 3- When the change in concentration exceeds the preset change, the cumulative reduction in dosage is reset to zero, and a new calculation is performed every five minutes.

4. The system for precise chemical phosphorus removal based on multi-point dosing and multi-point feedback as described in claim 3, characterized in that, The dosing logic operation module further includes a first learning submodule, which comprises a data acquisition component, a learning calculation component, and an execution dosing component. This submodule is used to train the calculation module to enhance the accuracy of chemical dosing. The learning calculation component is data-connected to the data acquisition component and receives n sets of corresponding data on total phosphorus in the middle stage, total phosphorus in the final stage, total phosphorus in the effluent, water volume, and actual dosing amount. It then selects m sets of data, inputs them into a built-in reinforcement learning program for training, and fits a more accurate CEPRM model formula. After training, it outputs the latest calculated dosing amount based on the latest total phosphorus data in the middle stage, total phosphorus in the final stage, total phosphorus in the effluent, and water volume. The execution dosing component calls the phosphorus removal dosing control module to output the chemical corresponding to the dosing amount.

5. A method for operating a chemical phosphorus removal precision dosing system based on multi-point dosing and multi-point feedback, using the chemical phosphorus removal precision dosing system based on multi-point dosing and multi-point feedback as described in any one of claims 1-4, characterized in that, The steps are as follows: 1) Every five minutes, the system receives total phosphorus data, orthophosphate data at the inlet, middle section, end section, and outlet, potassium ion data at the inlet, middle section, and end section, pH data at the end section, and water volume data, and sends them to the dosing logic operation module for processing. 2) The first comparison module in the dosing logic operation module determines whether to call the mid-stage dephosphorization dosing module to output the dosage. If called, the first calculation submodule and the first learning submodule are used to complete the preliminary calculation of the dephosphorization agent dosage, and the dephosphorization dosing module is called to complete the dosage adjustment. 3) Call the third comparison submodule and the third calculation submodule in the dosing logic operation module, and compare the pH value to determine Δn(PO4). 3- ) Calculate the change in concentration to determine whether the existing dosage of the intermediate phosphorus removal dosing module needs to be adjusted; 4) Implement the second comparison submodule in the dosing logic operation module to determine whether to call the terminal phosphorus removal dosing module to output the dosage. If it is determined that it needs to be called, use the second calculation submodule and the first learning submodule to complete the preliminary calculation of the phosphorus removal agent dosage and call the terminal phosphorus removal dosing module to adjust the dosage. 5) Run the fourth comparison submodule in the dosing logic operation module to compare the total phosphorus in the effluent with the target value. If the total phosphorus in the effluent is greater than the target value, call the final stage phosphorus removal dosing module and adjust the existing dosage in the final stage; otherwise, do not call the final stage phosphorus removal dosing module. 6) The total phosphorus concentration in the effluent should be controlled below the target value.

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