A carbon source adaptive dosing control method and system based on dynamic reference and stepwise coefficient

Abstract

This invention provides a carbon source adaptive dosing control method and system based on a dynamic baseline and a stepped coefficient, belonging to the field of wastewater treatment technology. The method includes: real-time acquisition of total nitrogen concentration and flow rate data of the effluent from the anoxic tank, calculating the total flow rate of the anoxic tank; setting a fixed reference value as a safety baseline and establishing an independent dynamic baseline initially; determining the stepped dosing coefficient by calculating the ratio of the current effluent total nitrogen concentration to the upper limit of discharge, and calculating the carbon source dosing amount when the ratio is zero; finally, by calculating the relative change amplitude with the dynamic baseline, triggering dosing adjustment only when there is a significant change in water quality, avoiding frequent system adjustments due to measurement noise or small fluctuations in water quality. This invention combines an absolute safety baseline with a relative change threshold, eliminating the need for complex models and frequent calibration, and offering fast response, strong disturbance resistance, and low cost.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to an adaptive carbon source dosing control method and system based on dynamic benchmarks and step coefficients. Background Technology

[0002] Biological denitrification is the main process for removing total nitrogen in wastewater treatment plants. During denitrification, heterotrophic bacteria require organic carbon sources as electron donors to reduce nitrate nitrogen to nitrogen gas. Most urban wastewater treatment plants have a low influent carbon-to-nitrogen ratio, meaning the raw water's organic carbon sources cannot meet the demands of denitrification. To ensure that the effluent's total nitrogen consistently meets discharge standards, the plant typically needs to add exogenous carbon sources such as sodium acetate and glucose. The accuracy, timeliness, and stability of carbon source addition directly determine the effluent quality compliance rate and the operating costs of the chemicals.

[0003] Currently, carbon source dosing control mainly includes manual adjustment, intelligent model prediction adjustment, and fixed parameter linear adjustment, but there are the following problems: (1) Manual adjustment: Operators adjust the frequency of the dosing pump based on experience according to the online total nitrogen data. This method is highly dependent on manual intervention and the adjustment response is lagging. When the influent water quality and water volume fluctuate significantly, it is very easy to cause insufficient carbon source dosing, resulting in excessive total nitrogen in the effluent, or excessive carbon source dosing, resulting in waste of reagents and increased operating costs. (2) Prediction model-based methods: such as using random forest, neural network, machine learning and other algorithms to build a carbon source demand prediction model. This type of method requires a large amount of historical data to train the model. The model has poor universality between different water plants, and the equipment investment and operation and maintenance costs are high. (3) Fixed standard dosing method: It pre-calibrates the standard carbon source dosing flow rate corresponding to a specific total nitrogen concentration through on-site tests, and then adjusts the dosing amount linearly according to the deviation of the real-time total nitrogen concentration from the calibration value. Although the control logic structure of this method is simple, the calibration parameters will quickly become invalid due to factors such as season, influent water quality, and recirculation conditions. Maintenance personnel need to recalibrate regularly, which is a lot of work and the control accuracy is difficult to guarantee.

[0004] Therefore, there is an urgent need to develop a carbon source addition control method that does not rely on complex models, does not require frequent calibration, and has simple and reliable control logic. Summary of the Invention

[0005] The main objective of this invention is to provide a carbon source adaptive dosing control method and system based on a dynamic baseline and a stepped coefficient, addressing the problems mentioned in the background art. This invention combines an absolute safety baseline with a relative change threshold, does not rely on complex prediction models, and requires no frequent calibration. It can quickly respond to the risk of exceeding limits while avoiding frequent adjustments caused by minor fluctuations, significantly reducing carbon source waste and operation and maintenance costs.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An adaptive carbon source dosing control method based on dynamic benchmarks and step coefficients includes the following steps: S1. Collect the total nitrogen concentration in the effluent from the anoxic tank. and total flow rate of pipeline And set a fixed reference value. and dynamic benchmark value ; S2, according to and Ratio calculation And determine the step-by-step addition coefficient. ; S3, Calculate the amount to be removed. Concentration and carbon source dosage ; S4. Compare and calculate the current... Relative to dynamic baseline value The decline or increase ; S5. Based on the range of change or Adjusting carbon source dosage and dynamic baseline .

[0007] In the preferred embodiment, in step S2, when When the carbon source addition is stopped, the dynamic baseline value will be adjusted. Reset to ;when Then proceed to the next calculation.

[0008] In the preferred embodiment, in step S2, the step-by-step addition coefficient The method for determining it is as follows: like ,but This is the area where dosing is stopped; like ,but This is the standard dosing area; like ,but This is the area of ​​slight boost; like ,but This is the medium boost zone; like ,but This is the emergency pressurization zone.

[0009] In the preferred embodiment, in step S3, the amount of carbon source added... According to the requirements for removal Concentration, total pipeline flow rate, and carbon source Calculated.

[0010] Specifically, in step S3 Concentration and carbon source dosage The calculation is as follows: Take the effective total nitrogen concentration The part to be removed concentration Wherein, the coefficient 5 represents the amount of nitrogen required to remove 1 mg / L of total nitrogen. (mg / L), which can be adjusted appropriately according to the actual carbon source utilization efficiency; Will Multiply by the total flow rate of the anoxic tank to obtain the required result. Then divide by the carbon source solution. equivalent The amount of carbon source added is obtained. .

[0011] Specifically, the carbon source in step S3 equivalent The method for determining it is as follows: ,in, The unit of content is The unit of density is , The unit is .

[0012] In the preferred embodiment, in step S4, Relative to dynamic baseline value The decline or increase The calculation formula is: like Then calculate the decrease ; like Then calculate the increase. ; like If the change is zero, then the change range is 0.

[0013] In the preferred embodiment, in step S5, based on the magnitude of change... or Adjusting carbon source dosage and dynamic baseline include: when and At that time, maintain the previous dosage and do not update. ; when and Then, recalculate according to step S3. and will Update to current ; when and At that time, maintain the previous dosage and do not update. ; when and Then, recalculate according to step S3. and will Update to current .

[0014] The dynamic benchmark value Only the decrease in total nitrogen concentration in the effluent or increase The parameters are updated under normal operating conditions and locked when the water quality fluctuates slightly, thus suppressing frequent fluctuations in the dosage.

[0015] In a preferred embodiment, in step S5, the updated dynamic reference value Equal to when adjustment is triggered But Forced update This new It will be used to calculate the magnitude of change in subsequent cycles, but it will not be included in the dosage formula. The calculation (the subtrahend in the formula is always fixed) ).

[0016] In a preferred embodiment, the method specifically includes the following steps: S1. Data Acquisition and Baseline Setting Collect total nitrogen concentration in the effluent from the anoxic pond Measure the inlet flow rate Internal return flow External return flow Calculate the total flow ; Set and store fixed reference values and maintain dynamic baseline values. initial value ; S2, Calculate the ratio And determine the step-by-step addition coefficient.

[0017] calculate ,according to The injection coefficient is determined within the preset interval. ;when At that time, stop adding and Reset to ;when Then proceed to the next step; S3, Calculate the amount to be removed. Concentration and carbon source dosage ; S4. Compare and calculate the current... Relative to dynamic baseline value The decline or increase ; S5. Based on the range of change or Adjusting carbon source dosage and dynamic baseline .

[0018] The present invention also provides an automatic carbon source dosing control system based on a safety baseline and a stepped coefficient, for executing the control method, comprising: The data acquisition unit includes an online total nitrogen monitor and a multi-channel flow meter, which is used to collect the total nitrogen concentration and flow data of each pipeline in the effluent of the anoxic tank in real time and upload them to the control unit. The control unit is connected to the data acquisition unit and the carbon source dosing execution unit in real time. It is used to receive total nitrogen concentration and flow rate data in real time, calculate the step dosing coefficient and the required carbon source dosing flow rate, adjust the dosing amount and update the benchmark value according to the change of the current total nitrogen relative to the dynamic benchmark value, and finally output the control signal to the frequency conversion metering pump. The carbon source dosing execution unit includes a variable frequency metering pump, which receives control signals output by the control unit and drives the metering pump to complete the quantitative dosing of carbon source.

[0019] In a preferred embodiment, the multi-channel flow meter includes: The inlet flow meter is installed on the inlet pipe to measure the inlet water flow rate. , An internal recirculation flow meter is installed in an internal recirculation pipe to measure the internal recirculation flow rate. , An external return flow meter, installed on the external return pipe, is used to measure the external return inlet flow rate. .

[0020] In the preferred embodiment, the monitoring cycle of the total nitrogen online monitor is 30-120 minutes, and the influent flow rate, internal return flow rate, and external return flow rate are continuously measured using an online flow meter.

[0021] In the preferred embodiment, the stepped addition coefficient ,according to Calculate the step-by-step addition coefficient within the specified interval. : like ,but This is the area where dosing is stopped; like ,but This is the standard dosing area; like ,but This is the area of ​​slight boost; like ,but This is the medium boost zone; like ,but This is the emergency pressurization zone.

[0022] In the preferred embodiment, the carbon source dosing flow rate is... The calculation is as follows: when At that time, calculate the amount to be removed. concentration Take effective total nitrogen Then the ones that need to be removed concentration Carbon source addition flow rate ; in, For the carbon source used Equivalent, unit: That is, the amount of carbon source contained per liter Grams.

[0023] In a preferred embodiment, the control unit is configured as follows: when and At that time, maintain the previous dosage and do not update. ; when and Recalculate and will Update to current (like ,but Updated to ); when and At that time, maintain the previous dosage and do not update. ; when and Recalculate and will Update to current .

[0024] In a preferred embodiment, the control unit further includes a safety limiting unit: when the calculated... At that time, the dosage was increased. When the dosage is increased When the flow rate exceeds the maximum flow rate of the variable frequency metering pump, the maximum flow rate will be used, and a high-level alarm signal will be generated.

[0025] In a preferred embodiment, the control unit further includes an emergency switching unit: when the total nitrogen online monitor receives invalid or out-of-range data for three consecutive cycles, it automatically switches to a static preset timed dosing mode (based on the average carbon source dosing amount during the same period in the past week) and triggers an audible and visual alarm; when the total nitrogen online monitor returns to normal, it automatically switches back to the adaptive control mode.

[0026] This invention establishes a fixed safety baseline directly linked to emission standards. And introduce a dynamic baseline value. Used to record historical status; calculates the current total nitrogen concentration in the effluent. With emission limits ratio Determine the step-by-step addition coefficient To achieve differentiated responses to different risk levels: when Stop adding carbon source when At that time, calculate the amount to be removed. Concentration, and combined with the total flow rate of the anoxic pool and carbon source. Equivalent, calculate the amount of carbon source added. Finally, through comparison With dynamic benchmark value The decline or increase ,when or Update the amount added in time And update Otherwise, maintain the original dosage and increase it. The system should remain unchanged to avoid frequent adjustments due to measurement noise or minor fluctuations in water quality.

[0027] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention provides a fixed safety baseline reference value ( It is directly linked to national or local wastewater discharge standards, and on-site operators can understand and master the control logic without needing to master complex mathematical models. At the same time, it abandons the traditional mode of relying on on-site steady-state tests to calibrate benchmark parameters for dosing schemes. It can operate autonomously by relying only on fixed coefficients, preset baselines, and real-time measured water quality and flow parameters, which greatly simplifies the system debugging process, reduces manual intervention, and significantly reduces equipment operation and maintenance and labor costs.

[0028] 2. This invention incorporates the carbon source dosage calculation into the total treatment flow rate of the anoxic tank (the sum of influent flow rate, internal recirculation flow rate, and external recirculation flow rate), enabling the carbon source dosage to adapt in real time to the dynamic changes in influent flow rate and recirculation conditions; simultaneously, it combines the actual carbon source... Equivalent completion theory The precise conversion between required volume and carbon source solution dosage avoids the systematic error of traditional technology that directly uses concentration difference to equivalently calculate the dosage flow rate. It can still ensure the accuracy of carbon source dosage under complex hydraulic and water quality conditions, prevent over-dosing and carbon source waste, and save on reagent costs.

[0029] 3. This invention sets an independent dynamic benchmark and a total nitrogen reduction rate. growth rate The differentiated adjustment dead zone threshold only updates the dosage and baseline parameters when the total nitrogen concentration fluctuates significantly. This effectively filters instrument noise and short-term, minor water quality disturbances, avoids frequent start-stop and frequency oscillations of the metering pump, stabilizes equipment operating conditions, and extends equipment lifespan. Dosage coefficient Based on the ratio of total nitrogen in effluent to the discharge limit The dosage increases in stages, reaching up to twice the standard dosage; the closer the total nitrogen concentration in the effluent is to the discharge limit, the less supplement is required. The faster the concentration increases, the more quickly the upward trend of total nitrogen can be curbed, effectively avoiding the risk of exceeding the standard in the effluent; when the total nitrogen concentration is within the safe range, the dosage will be automatically reduced or stopped, maximizing the conservation of carbon source agents.

[0030] 4. This invention employs basic logical judgment and linear operations throughout, eliminating the need for complex prediction models such as machine learning and neural networks, and requiring no training with massive amounts of historical data. It can be directly programmed onto conventional industrial PLCs, resulting in low hardware modification costs, strong compatibility, and suitability for the intelligent transformation of most small and medium-sized wastewater treatment plants. This can be achieved by adjusting process coefficients, total nitrogen emission limits, or carbon sources. The system can match the addition requirements of different emission standards and different types of carbon sources with parameters such as equivalent. Furthermore, external operating condition disturbances such as water temperature and load shocks can be adaptively corrected through real-time water quality data without the need for additional compensation modules. The system has a simple structure, strong robustness, and wide applicability. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] To address the problems of existing carbon source dosing technologies, such as lag in manual adjustment, reliance on complex models, frequent calibration requirements, and control logic prone to frequent adjustments or untimely responses, this invention provides an adaptive carbon source dosing control method based on dynamic benchmarks and step coefficients. Its core lies in dividing the control logic into two functions: dosing calculation and adjustment timing determination. The dosing calculation employs a two-step method: first, based on the real-time collected total nitrogen concentration in the anoxic tank effluent (… ) and the preset fixed safety baseline (Pick The difference between the values ​​(directly linked to emission standards) and the target water quality risk level is multiplied by a tiered dosage coefficient determined by the water quality risk level. Calculate the amount that needs to be removed. Concentration (mg / L); then, the Multiply the concentration by the total flow rate of the anoxic tank (i.e., influent flow rate + internal return flow rate + external return flow rate), then divide by the amount of carbon source solution used. The equivalent (gCOD / L) is used to obtain the actual dosing flow rate (L / h) of the carbon source solution. The timing of adjustments is determined by a dynamic baseline value. accomplish, The initial value is set to a fixed safety baseline. Only in the present Relative to dynamic benchmark When the change reaches the preset threshold (decrease) or increase Only after this process is completed will the newly calculated added flow be used as the execution volume, and the flow will be synchronized accordingly. Update to the current If the change does not reach the threshold, then maintain the previous dosage and... The value remains unchanged to avoid frequent adjustments due to measurement noise or normal fluctuations in water quality. If Below the fixed safety baseline Immediately stop adding carbon source and set the dynamic baseline. Reset to This is to prepare for the next possible need for additional supplies.

[0033] The adaptive carbon source dosing control method based on dynamic benchmarks and step coefficients specifically includes the following steps: S1. Data Acquisition and Baseline Setting An online total nitrogen monitor was installed at the end of the anoxic tank to continuously collect the total nitrogen concentration in the effluent from the anoxic tank in real time. Simultaneously, flow meters were installed on the inlet pipe, internal return pipe, and external return pipe to continuously measure the inlet flow rate. Internal return flow External return flow And calculate the total flow rate of the anoxic pool. .

[0034] A total nitrogen emission ceiling is set based on the emission standards implemented by the wastewater treatment plant. and determine a fixed reference value. This value remains unchanged during operation. The physical meaning is 40% of the emission limit, i.e., the safety baseline. When the total nitrogen concentration in the effluent is below... When the time is right, you can stop adding the product.

[0035] Set dynamic baseline value initial value . This is used to record the total nitrogen concentration at the time of the most recent triggering of the carbon source dosage adjustment, and is used for subsequent calculations of the magnitude of the change. Updates independent of .

[0036] S2, Calculate the ratio And determine the step-by-step addition coefficient.

[0037] The control system receives the current Calculate its ratio to the emission limit. .

[0038] according to For the given interval, determine the tiered addition coefficient according to the table below. :

[0039] when When this happens, the control system stops adding carbon source and sets the dynamic baseline value. Reset to ;when Then proceed to the next calculation.

[0040] S3, Calculate the amount to be removed. Concentration and carbon source dosage To prevent abnormally low measured values If a negative difference occurs, the effective total nitrogen concentration should be taken. That is, when measured Below At that time, according to Calculate (the amount to be removed at this point) (Concentration is 0).

[0041] Need to be removed concentration ( Calculate using the following formula: ; Will Multiply by the total flow rate of the anoxic tank to obtain the required result. Total ( ),Right now ; Then divide by the carbon source solution. equivalent ( ), to obtain the required carbon source addition amount (L / h): ; Among them, carbon source equivalent The method for determining this is based on the carbon source density ( )and content( ),calculate .

[0042] S4. Calculate the current TN 出 The magnitude of change relative to the dynamic baseline value Compare the current Compared with the current dynamic baseline value Calculate the magnitude of change: like Then calculate the decrease ; like Then calculate the increase. ; like If the change is zero, then the change range is 0.

[0043] S5. Adjust the carbon source dosage and update the dynamic baseline value according to the change range. Based on the direction and magnitude of the change, the following four scenarios should be considered: (1) When and At this time: Do not adjust the dosage; maintain the dosage from the previous execution. Dynamic benchmark value It's not being updated either; (2) When and At this time: update the dosage to the amount newly calculated according to step S3. and dynamic benchmark value Update to current ,but Updated to ; (3) When and At this time: Do not adjust the dosage; maintain the dosage from the previous execution. Dynamic benchmark value It's not being updated either; (4) When and At this time: update the dosage to the amount newly calculated according to step S3. and dynamic benchmark value Update to current .

[0044] It should be noted that after the update Equal to when adjustment is triggered (like When that happens, a forced update will be performed. This new one. It will be used to calculate the magnitude of change in subsequent cycles, but it will not be included in the dosage formula. The calculation (the subtrahend in the formula is always fixed) ).

[0045] S6. Perform carbon source addition. The control system converts the final determined dosage into the operating frequency (or stroke length) of the variable frequency metering pump and sends it to the pump via a 4-20mA analog signal or digital communication protocol. The carbon source dosing pump then adds carbon source to the anoxic tank according to the instructions.

[0046] At the end of each monitoring cycle, the control system automatically returns to step S1 to re-collect TN. 出 By combining the flow data, the above process is repeated to form a continuous closed-loop control.

[0047] The method of this invention calculates the required removal using a fixed safety baseline (40% of the upper limit of total nitrogen emissions) as an absolute reference. Concentration, combined with the total flow rate of the anoxic tank and the carbon source The equivalent flow rate is converted into the actual carbon source solution addition flow rate. At the same time, the relative change range is judged by the dynamic benchmark value (thresholds of 10% decrease and 5% increase). Under the premise of ensuring rapid response to the risk of exceeding the standard, unnecessary adjustment actions are reduced, carbon source consumption and pump wear are reduced, which has significant economic benefits.

[0048] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0049] Example 1: A certain town's wastewater treatment plant implements the Class A discharge standard, with a total nitrogen discharge limit of [missing information]. Fixed reference value Initial dynamic baseline value .

[0050] 1. Data Acquisition and Benchmark Setting The current dosage is 0, and the total nitrogen monitoring cycle is 60 minutes.

[0051] At 8:00, the total nitrogen concentration in the effluent from the end of the anoxic tank was measured. ; Inlet flow rate Internal return flow External return flow (Equivalent to a 100% reflux ratio), then the total flow rate of the anoxic tank... .

[0052] Set dynamic baseline value initial value .

[0053] 2. Calculate the step-by-step addition coefficient.

[0054] according to ,calculate If it falls within the 40% to 60% range, then .

[0055] 3. Calculate the amount of carbon source added. To prevent abnormally low measured values If a negative difference occurs, the effective total nitrogen concentration should be taken. According to Calculated ; The carbon source used was a 25% sodium acetate solution with a density of , content ,but ; Required The total amount is based on the formula Calculated ; Required carbon source addition .

[0056] 4. Based on the current situation Compared with the current dynamic baseline value Calculate the range of change growth rate Trigger adjustment; execute dosage increase ,Will Updated to .

[0057] 5. At 9:00, the measurement was... , at this time .

[0058] .

[0059] current growth rate No adjustment will be triggered; execution will continue. , Keep .

[0060] 6. At 10:00, the measurement was... .

[0061] at this time (The boundary belongs to 40%~60%) .

[0062] .

[0063] increase Trigger adjustment; execute , Updated to .

[0064] Example 2: Based on Example 1, at 10:00, the influent flow rate was from... Suddenly rise to Internal reflux remains External reflux remains ,at this time Simultaneously measured .

[0065] Calculated If it falls within the 60% to 80% range, then .

[0066] calculate ; Required ; The amount of carbon source added .

[0067] current growth rate Trigger adjustment; execute , Updated to .

[0068] The system automatically adjusts the dosage from Raise to It can respond to increased load without human intervention.

[0069] Example 3: Based on Example 2, Execution volume Then the total nitrogen began to decrease.

[0070] At 11:00, it was measured .

[0071] calculate ,but .

[0072] calculate ;but .

[0073] Decrease No adjustment is triggered; continue execution. (Maintain high injection rate and increase volume). constant.

[0074] Measured at 12:00 .

[0075] This triggers an adjustment.

[0076] .

[0077] implement , Updated to At this time, the dosage is from Down to This effectively avoids excessive dosage.

[0078] Example 4: Based on Example 3, Execution dosage .

[0079] At 13:00, it was measured .

[0080] calculate ,but .

[0081] Stop adding carbon sources and Reset to .

[0082] If the total nitrogen concentration subsequently rises above And the increase reached The system will restart from Start the calculation.

[0083] Example 5: The wastewater treatment plant will use 25% sodium acetate ( Replace with liquid glucose. ; Add the carbon source to the controller parameter table Equivalent from Change to Afterwards, , Calculate the new carbon source addition amount The system adapts automatically, requiring no modification to the control logic.

[0084] Example 6: A certain town's wastewater treatment plant has a designed treatment capacity of 30,000 m³. 3 / d, the effluent complies with the Class A standard of the "Discharge Standard of Pollutants for Urban Wastewater Treatment Plants", with a total nitrogen emission limit of ≤15mg / L, and an average daily treatment capacity of 23,600 m³. 3 The average influent pH was 7.3, COD was 215 mg / L, ammonia nitrogen concentration was 40 mg / L, total nitrogen concentration was 48 mg / L, total phosphorus concentration was 5.3 mg / L, and SS was 127 mg / L. The plant previously relied on manual experience for carbon source addition: under manual addition mode, continuous monitoring data for 90 days showed that the average daily total nitrogen concentration in the effluent was 5.5~14.1 mg / L, with five instances of instantaneous concentration exceeding the standard.

[0085] After adopting the adaptive carbon source dosing control method of this invention, and after 90 days of continuous monitoring, the total nitrogen concentration in the effluent remained stable, with a daily average concentration of 6.8~10.3 mg / L, and no instantaneous exceedances. Compared with manual adjustment experience, the effluent quality range was smaller and the operation was more stable when the influent water quality remained similar. Comparing the measured daily average total nitrogen concentration in the effluent, manual carbon source adjustment resulted in an effluent total nitrogen concentration of 5.5~14.1 mg / L; after adopting the adaptive dosing control method, the effluent total nitrogen concentration was 6.8~10.3 mg / L. With similar treatment volume and influent water quality, the daily average artificial carbon source dosage was 9.65t, while the adaptive carbon source dosage was 6.32t, saving approximately 3.33t / d compared to manual adjustment, significantly reducing the amount of carbon source required.

[0086] Example 7: A certain town's wastewater treatment plant has a designed treatment capacity of 100,000 m³. 3 / d, the effluent meets the Class A discharge standard (total nitrogen ≤15mg / L), with a daily treatment capacity of 92,000 m³. 3 The average influent pH was 7.5, COD concentration was 198 mg / L, ammonia nitrogen concentration was 37 mg / L, total nitrogen concentration was 45 mg / L, total phosphorus concentration was 6.2 mg / L, and SS concentration was 83 mg / L. The plant originally used a random forest model for automatic carbon source addition. Due to the renovation of surrounding wastewater treatment plants, external wastewater flowed into the plant, significantly changing the influent conditions: the average daily total nitrogen concentration increased from 35 mg / L to 45 mg / L, and the average daily treated water volume increased from 70,000 m³ / day. 3 / d increased to 92,000 m 3 / d. After the influent operating conditions changed abruptly, the prediction accuracy of the original model dropped significantly, and the total nitrogen concentration in the effluent fluctuated drastically, ranging from 6.3 to 13.9 mg / L, with instantaneous detection values ​​repeatedly approaching the discharge limit.

[0087] After adopting the adaptive carbon source dosing control method of this invention, the system stabilized within the first week of operation, with the daily average total nitrogen concentration in the effluent consistently maintained at 7.5~10.8 mg / L, and the instantaneous value not exceeding 12 mg / L. Compared with model predictions, the operational results show a smaller effluent quality range and more stable operation when the influent water quality remains similar. Comparing the measured daily average total nitrogen concentration in the effluent, the model predicted an adjusted total nitrogen concentration of 6.3~13.9 mg / L; after adopting the adaptive dosing control method, the effluent total nitrogen concentration was 7.5~10.8 mg / L. With similar treatment volume and influent water quality, the daily carbon source dosing predicted by the model was 28.60 t, while the adaptive carbon source dosing was 20.63 t, saving approximately 7.97 t compared to the model prediction, significantly reducing the amount of carbon source required.

[0088] Significantly reduces the amount of carbon source input.

[0089] Example 8: This embodiment provides a control system for executing the above-described control method, comprising: The data acquisition unit includes an online total nitrogen monitor and a multi-channel flow meter, which is used to collect the total nitrogen concentration and flow data of each pipeline in the effluent of the anoxic tank in real time and upload them to the control unit. The control unit is connected to the data acquisition unit and the carbon source dosing execution unit in real time. It is used to receive total nitrogen concentration and flow rate data in real time, calculate the step dosing coefficient and the required carbon source dosing amount, adjust the dosing amount and update the benchmark value according to the change of the current total nitrogen relative to the dynamic benchmark value, and finally output the control signal to the frequency conversion metering pump. The carbon source dosing execution unit includes a variable frequency metering pump, which receives control signals output by the control unit and drives the metering pump to complete the quantitative dosing of carbon source.

[0090] In a preferred embodiment, the monitoring cycle of the total nitrogen online monitor is 30-120 minutes, and the influent flow rate, internal return flow rate, and external return flow rate are continuously measured using an online flow meter.

[0091] In a preferred embodiment, the stepped addition coefficient ,according to Calculate the step-by-step addition coefficient within the specified interval. : like ,but This is the area where dosing is stopped; like ,but This is the standard dosing area; like ,but This is the area of ​​slight boost; like ,but This is the medium boost zone; like ,but This is the emergency pressurization zone.

[0092] In a preferred embodiment, the carbon source dosing flow rate The calculation is as follows: when At that time, calculate the amount to be removed. concentration Take effective total nitrogen Then the ones that need to be removed concentration Carbon source addition flow rate ; in, For the carbon source used Equivalent, unit: That is, the amount of carbon source contained per liter Grams.

[0093] In a preferred embodiment, the control unit is configured as follows: when and At that time, maintain the previous dosage and do not update. ; when and Recalculate and will Update to current (like ,but Updated to ); when and At that time, maintain the previous dosage and do not update. ; when and Recalculate and will Update to current .

[0094] In a preferred embodiment, the control unit further includes a safety limiting unit: when the calculated... At that time, the dosage was increased. When the dosage is increased When the flow rate exceeds the maximum flow rate of the variable frequency metering pump, the maximum flow rate will be used, and a high-level alarm signal will be generated.

[0095] In a preferred embodiment, the control unit further includes an emergency switching unit: when the total nitrogen online monitor's data is invalid or out of range for three consecutive cycles, it automatically switches to a static preset timed dosing mode (based on the average carbon source dosing amount during the same period in the past week) and triggers an audible and visual alarm; when the total nitrogen online monitor returns to normal, it automatically switches back to the adaptive control mode.

[0096] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. An adaptive carbon source dosing control method based on dynamic benchmarks and step coefficients, characterized in that, Includes the following steps: S1. Collect the total nitrogen concentration in the effluent from the anoxic tank. and total flow rate of pipeline And set a fixed reference value. and dynamic benchmark value ; S2, according to and Ratio calculation And determine the step-by-step addition coefficient. ; S3, Calculate the amount to be removed. Concentration and carbon source dosage ; S4. Compare and calculate the current... Relative to dynamic baseline value The decline or increase ; S5. Based on the range of change or Adjusting carbon source dosage and dynamic baseline .

2. The adaptive carbon source dosing control method based on dynamic benchmark and step coefficient as described in claim 1, characterized in that, In step S2, when When the carbon source addition is stopped, the dynamic baseline value will be adjusted. Reset to ;when Then proceed to the next calculation.

3. The adaptive carbon source dosing control method based on dynamic benchmark and step coefficient as described in claim 2, characterized in that, In step S2, the step-wise addition coefficient The method for determining it is as follows: like ,but This is the area where dosing is stopped; like ,but This is the standard dosing area; like ,but This is the area of ​​slight boost; like ,but This is the medium boost zone; like ,but This is the emergency pressurization zone.

4. The adaptive carbon source dosing control method based on dynamic benchmark and step coefficient as described in claim 1, characterized in that, In step S3, the amount of carbon source added... According to the requirements for removal Concentration, total pipeline flow rate, and carbon source Calculated.

5. The adaptive carbon source dosing control method based on dynamic benchmark and step coefficient as described in claim 1, characterized in that, In step S4 Relative to dynamic baseline value The decline or increase The calculation formula is: like Then calculate the decrease ; like Then calculate the increase. ; like If the change is zero, then the change range is 0.

6. The adaptive carbon source dosing control method based on dynamic benchmark and step coefficient as described in claim 1, characterized in that, In step S5, based on the magnitude of change or Adjusting carbon source dosage and dynamic baseline include: when and At that time, maintain the previous dosage and do not update. ; when and Then, recalculate according to step S3. and will Update to current ; when and At that time, maintain the previous dosage and do not update. ; when and Then, recalculate according to step S3. and will Update to current .

7. The adaptive carbon source dosing control method based on dynamic benchmark and step coefficient as described in claim 6, characterized in that, Updated dynamic baseline value Equal to when adjustment is triggered But Forced update .

8. A carbon source adaptive dosing control system based on dynamic benchmarks and step coefficients, characterized in that, For performing the control method according to any one of claims 1-17, comprising: The data acquisition unit includes an online total nitrogen monitor and a multi-channel flow meter, which is used to collect the total nitrogen concentration and flow data of each pipeline in the effluent of the anoxic tank in real time and upload them to the control unit. The control unit is connected to the data acquisition unit and the carbon source dosing execution unit in real time. It is used to receive total nitrogen concentration and flow rate data in real time, calculate the step dosing coefficient and the required carbon source dosing flow rate, adjust the dosing amount and update the benchmark value according to the change of the current total nitrogen relative to the dynamic benchmark value, and finally output the control signal to the frequency conversion metering pump. The carbon source dosing execution unit includes a variable frequency metering pump, which receives control signals output by the control unit and drives the metering pump to complete the quantitative dosing of carbon source.

9. The adaptive carbon source dosing control system based on dynamic benchmark and step coefficient as described in claim 8, characterized in that, The control unit also includes a safety limiting unit: when the calculated... At that time, the dosage was increased. When the dosage is increased When the flow rate exceeds the maximum flow rate of the variable frequency metering pump, the maximum flow rate will be used, and a high-level alarm signal will be generated.

10. The adaptive carbon source dosing control system based on dynamic benchmark and step coefficient as described in claim 8, characterized in that, The control unit also includes an emergency switching unit: when the total nitrogen online monitor receives invalid or out-of-range data for three consecutive cycles, it automatically switches to the static preset timed dosing mode and triggers an audible and visual alarm; when the total nitrogen online monitor returns to normal, it automatically switches back to the adaptive control mode.

Images