Automatic denitrification control system and method for five-stage burka sewage treatment process

Abstract

The invention relates to an automatic denitrification control system and method for a five-stage burka sewage treatment process, the five-stage burka sewage treatment process is realized based on a plurality of reaction tanks, the automatic control system comprises a controller, and the controller controls the control parameters of regulation and control components arranged on the plurality of reaction tanks, so that the control parameters of the regulation and control components are adjusted and controlled, and the control parameters of the regulation and control components are adjusted and controlled. The denitrification efficiency of the five-section burkton sewage treatment process is controlled; the regulation and control assembly comprises an internal reflux pipeline which is connected to the tail end of the front aerobic tank and the front end of the front anoxic tank; the output end of the dosing pipeline is connected with the rear anoxic tank; the controller is respectively in communication connection with the internal reflux pipeline and the dosing pipeline and is used for controlling the internal reflux ratio of the internal reflux pipeline; and controlling the amount of the carbon source fed into the rear anoxic tank. Based on the system provided by the invention, the regulation and control means corresponding to each coupling reaction area is single, and the denitrification effect generated by each realized regulation and control means is more accurate and clear, so that independent fine control can be respectively carried out, and the denitrification efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment, and in particular to an automatic denitrification control system for a five-stage Batunfu sewage treatment process and an automatic denitrification control method for a five-stage Batunfu sewage treatment process. Background Art

[0002] The five-stage Bardenpho process is a common wastewater treatment technology used in urban wastewater treatment plants. It boasts high denitrification rates and flexible control. It removes organic matter, nitrogen, and phosphorus through microbial reactions in different zones. While the five-stage Bardenpho process has proven effective in improving wastewater treatment, traditional control methods struggle to meet the dynamic demands of actual operations due to fluctuations in influent quality and increasing complexity in the treatment process.

[0003] Specifically, the five-stage Batumfu includes an anaerobic tank, a front anoxic tank, a front aerobic tank, a rear anoxic tank, and a rear aerobic tank, which are connected in sequence. The material transfer and microbial reactions between the reaction tanks are coupled, and there are many control variables that influence each other. Existing control strategies usually treat the front anoxic tank and the front aerobic tank as a coupled reaction zone, and the rear anoxic tank and the rear aerobic tank as a coupled reaction zone. For each coupled reaction zone, the denitrification effect of the coupled reaction zone is adjusted by adjusting the internal reflux ratio and the amount of carbon source. However, in actual application, the denitrification effect produced by the internal reflux ratio and the dosage are coupled, which makes it difficult to independently and finely control the two control measures of the internal reflux ratio and the dosage.

[0004] Furthermore, existing technologies rely on manual experience to adjust the internal recirculation ratio and carbon source amount. This control method is relatively crude and cannot respond to fluctuations in influent water quality in real time. This leads to large fluctuations in nitrate nitrogen concentration in the anoxic tank, affecting denitrification efficiency. In particular, the regulation of carbon source amount is usually based on a fixed ratio or experience, which can easily lead to carbon source waste or insufficient nitrate nitrogen removal. When the influent water quality or water quantity suddenly changes, the control method relying on manual experience also has a lag in control, which can easily lead to excessive TN in the effluent. Summary of the Invention

[0005] (1) Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present application provides a denitrification automatic control system for a five-stage Batunfu sewage treatment process and a denitrification automatic control method for a five-stage Batunfu sewage treatment process, which solves the problem that the prior art cannot finely control the two control measures of internal reflux ratio and dosage.

[0007] (2) Technical solution

[0008] In order to achieve the above objectives, the main technical solutions adopted in this application include:

[0009] In a first aspect, an embodiment of the present application provides a denitrification automatic control system for a five-stage Batunfu sewage treatment process, wherein the five-stage Batunfu sewage treatment process is implemented based on multiple reaction tanks, wherein the reaction tanks include an anaerobic tank, a front anoxic tank, a front aerobic tank, a rear anoxic tank, and a rear aerobic tank connected in sequence. The automatic control system includes a controller, and the controller regulates the denitrification efficiency of the five-stage Batunfu sewage treatment process through a regulation component provided on the multiple reaction tanks; the regulation component includes:

[0010] An internal return pipe is connected to the end of the front aerobic tank and the front end of the front anoxic tank, and is used to return part of the sewage at the end of the front aerobic tank to the front end of the front anoxic tank;

[0011] A dosing pipeline, the output end of which is connected to the post-anoxic tank and is used to add a carbon source to the post-anoxic tank;

[0012] The controller is communicatively connected to the internal reflux pipe and the dosing pipe, respectively, and is used to control the internal reflux ratio of the internal reflux pipe according to the first nitrate nitrogen concentration at the end of the front anoxic tank and the second nitrate nitrogen concentration at the front end of the rear anoxic tank; and to control the amount of carbon source added to the rear anoxic tank according to the second nitrate nitrogen concentration at the front end of the rear anoxic tank, the organic nitrogen concentration at the end of the rear anoxic tank, the ammonia nitrogen concentration at the end of the rear anoxic tank and the preset internal control concentration value of the water plant effluent TN.

[0013] Optionally, the controller includes: a first judgment module and an internal reflux control module;

[0014] The first judgment module is used to judge whether the current first nitrate nitrogen concentration is within a preset control range in each adjustment period, and if not, jump to the internal reflux control module;

[0015] The internal reflow control module is used to calculate the return nitrate nitrogen concentration of the sewage returning through the internal reflow pipe, and to calculate the target adjustment amount of the first nitrate nitrogen concentration; and to determine the adjusted internal reflow ratio based on the return nitrate nitrogen concentration and the target adjustment amount.

[0016] Optionally, in the internal recirculation control module, calculating the current recirculation nitrate nitrogen concentration of the recirculated sewage in the internal recirculation pipe, and calculating the target adjustment amount of the first nitrate nitrogen concentration include:

[0017] The product of the current internal reflux ratio and the second nitrate nitrogen concentration is used as the current reflux nitrate nitrogen concentration;

[0018] The difference between the current first nitrate nitrogen concentration and the preset internal control value of the first nitrate nitrogen concentration is used as the target adjustment amount.

[0019] Optionally, in the internal reflux control module, determining the adjusted internal reflux ratio according to the reflux nitrate nitrogen concentration and the target adjustment amount includes:

[0020] The difference between the current reflux nitrate nitrogen concentration and (1 + r) times the target adjustment amount is used as the first proportional factor; where r is the external reflux ratio of the five-stage Batumu wastewater treatment process;

[0021] The sum of the current second nitrate nitrogen concentration and the target adjustment amount is used as a second proportional factor;

[0022] The ratio of the first proportional factor to the second proportional factor is used as the adjusted internal reflux ratio.

[0023] Optionally, the controller further comprises: a second judgment module and a drug addition control module;

[0024] The second judgment module is used to judge whether the current second nitrate nitrogen concentration is greater than the internal control value of the third nitrate nitrogen concentration at the end of the rear anoxic tank in each adjustment period, and if so, jump to the dosing control module;

[0025] The dosing control module is used to determine the target removal amount of nitrate nitrogen in the post-anoxic tank based on the second nitrate nitrogen concentration, the organic nitrogen concentration at the end of the post-anoxic tank, the ammonia nitrogen concentration at the end of the post-anoxic tank and the preset internal control concentration value of the water plant effluent TN; and determine the target amount of carbon source to be added to the post-anoxic tank based on the target removal amount.

[0026] Optionally, in the dosing control module, the target removal amount of nitrate nitrogen in the post-anoxic tank is determined according to the second nitrate nitrogen concentration, the organic nitrogen concentration at the end of the post-anoxic tank, the ammonia nitrogen concentration at the end of the post-anoxic tank, and a preset internal control concentration value of the water plant effluent TN, including:

[0027] The preset internal control concentration value of TN of the water plant effluent is subtracted in sequence from the current ammonia nitrogen concentration at the end of the post-anoxic tank and the organic nitrogen concentration at the end of the post-anoxic tank as the basic target value;

[0028] The difference between the current second nitrate nitrogen concentration and the basic target value is used as the target removal amount of nitrate nitrogen in the post-anoxic tank.

[0029] Optionally, in the dosing control module, determining the target amount of carbon source to be added to the post-anoxic tank according to the target removal amount includes:

[0030] The target carbon source amount is obtained by multiplying the target removal amount by the carbon source equivalent required to remove unit nitrate nitrogen by the carbon source used, and dividing it by the concentration of the carbon source agent used. The sum of the agent compensation amount required to eliminate the dissolved oxygen in the anoxic tank and the theoretical agent amount is used as the target carbon source amount.

[0031] Optionally, the controller further includes:

[0032] The dynamic correction module for dosing is used to compensate and adjust the target carbon source amount based on the current water inflow of the water plant according to the following formula in each adjustment cycle to determine the final amount of carbon source added to the post-anoxic tank;

[0033]

[0034] Among them, C f It represents the final amount of carbon source added to the post-anoxic tank;

[0035] C g It represents the target amount of carbon source added to the post-anoxic tank;

[0036] Q0 represents the current inflow flow of the water plant;

[0037] Q 设计 Indicates the designed inlet flow of the water plant;

[0038] α represents the correction coefficient, and its value range is [0.1, 0.7].

[0039] Optionally, the control component further includes:

[0040] An internal reflux pump and an internal reflux flow meter provided on the internal reflux pipeline; and / or,

[0041] A carbon source container, a metering pump and a dosing pump are provided on the dosing pipeline; and / or,

[0042] A water inlet flow meter provided at the front end of the front aerobic tank; and / or,

[0043] a first nitrate nitrogen concentration meter provided at the end of the front anoxic tank; and / or,

[0044] a second nitrate nitrogen concentration meter provided at the front end of the post-anoxic tank; and / or

[0045] An ammonia nitrogen concentration meter is provided at the end of the post-anoxic tank.

[0046] In the second aspect, an embodiment of the present application provides a denitrification automatic control method for a five-stage Batunfu sewage treatment process. The denitrification automatic control method is based on the denitrification automatic control system of the five-stage Batunfu sewage treatment process described in the first aspect, and controls the denitrification efficiency of the five-stage Batunfu sewage treatment process.

[0047] (3) Beneficial effects

[0048] The beneficial effects of the present application are as follows: the denitrification automatic control system of the present application includes an internal reflux pipe and a dosing pipe. The internal reflux pipe is connected to the end of the front aerobic tank and the front end of the front anoxic tank, and is used to return part of the sewage at the end of the front aerobic tank to the front end of the front anoxic tank. The dosing pipe, whose output end is connected to the rear anoxic tank, is used to add a carbon source to the rear anoxic tank. That is to say, the front coupling reaction zone formed by the front anoxic tank and the front aerobic tank of the present application controls the denitrification effect through the internal reflux ratio, and the rear coupling reaction zone formed by the rear anoxic tank and the rear aerobic tank of the present application controls the denitrification effect through the amount of carbon source added. The control means corresponding to each coupled reaction zone is single, and the denitrification effect produced by each control means is also more precise and clear, so that independent and refined control can be performed separately, thereby improving the denitrification efficiency.

[0049] In addition, the controller used in the denitrification automatic control system of the present application controls the internal reflux ratio of the internal reflux pipe according to the first nitrate nitrogen concentration at the end of the front anoxic tank and the second nitrate nitrogen concentration at the front end of the rear anoxic tank; and controls the amount of carbon source added to the rear anoxic tank according to the second nitrate nitrogen concentration at the front end of the rear anoxic tank, the organic nitrogen concentration at the end of the rear anoxic tank, the ammonia nitrogen concentration at the end of the rear anoxic tank and the preset internal control concentration value of the water plant effluent TN. The denitrification control system of the present application can accurately and dynamically adjust the internal reflux ratio of the internal reflux pipe and the amount of carbon source added to the rear anoxic tank based on their own independent pipelines according to the above-mentioned parameter changes of each reaction tank, thereby improving denitrification efficiency and reducing carbon source consumption. At the same time, the two are independently regulated and coordinated to control the nitrate nitrogen concentration of the sewage flowing through the front coupling reaction zone and the rear coupling reaction zone in each adjustment cycle to ensure maximum denitrification efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic diagram of the connection between a reaction tank and a control component provided thereon for implementing a five-stage Batumu sewage treatment process provided in an embodiment;

[0051] Figure 2 A schematic diagram of the architecture of a controller provided in an embodiment;

[0052] Figure 3 This is a connection diagram of another reaction tank and the control components provided thereon for realizing the five-stage Batumu sewage treatment process provided in the embodiment. DETAILED DESCRIPTION

[0053] In order to better explain the present application and facilitate understanding, the present application is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0054] To better understand the above technical solutions, exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a clearer and more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0055] Example 1

[0056] This embodiment provides a denitrification automatic control system for a five-stage Batumu sewage treatment process, such as Figure 1 As shown, the five-stage Batunfu sewage treatment process is implemented based on multiple reaction tanks, which include an anaerobic tank, a front anoxic tank, a front aerobic tank, a rear anoxic tank, and a rear aerobic tank connected in sequence. The automatic control system includes a controller, which controls the denitrification efficiency of the five-stage Batunfu sewage treatment process through control components provided on the multiple reaction tanks. The control components include:

[0057] The internal return pipe is connected to the end of the front aerobic tank and the front end of the front anoxic tank, and is used to return part of the sewage at the end of the front aerobic tank to the front end of the front anoxic tank.

[0058] The dosing pipeline has an output end connected to the post-anoxic tank and is used to add a carbon source to the post-anoxic tank.

[0059] Specifically, the internal reflux pipe is provided with an internal reflux pump and an internal reflux flow meter; the dosing pipe is provided with a carbon source container, a metering pump and a dosing pump; the front end of the front aerobic tank is provided with a water inlet flow meter; the end of the front anoxic tank is provided with a first nitrate nitrogen concentration meter; the front end of the rear anoxic tank is provided with a second nitrate nitrogen concentration meter; and the end of the rear anoxic tank is provided with an ammonia nitrogen concentration meter.

[0060] The controller is communicatively connected to the internal reflux pipe and the dosing pipe, respectively, and is used to control the internal reflux ratio of the internal reflux pipe according to the first nitrate nitrogen concentration at the end of the front anoxic tank and the second nitrate nitrogen concentration at the front end of the rear anoxic tank; and to control the amount of carbon source added to the rear anoxic tank according to the second nitrate nitrogen concentration at the front end of the rear anoxic tank, the organic nitrogen concentration at the end of the rear anoxic tank, the ammonia nitrogen concentration at the end of the rear anoxic tank and the preset internal control concentration value of the water plant effluent TN.

[0061] Based on the above configuration, the coupled reaction zone formed by the front anoxic tank and the front aerobic tank in this application controls the denitrification effect through the internal reflux ratio, while the coupled reaction zone formed by the rear anoxic tank and the rear aerobic tank in this application controls the denitrification effect through the amount of carbon source added. Each coupled reaction zone has a single corresponding control method, and the denitrification effect produced by each control method is more precise and clear, allowing for independent and refined control, thereby improving denitrification efficiency.

[0062] Example 2

[0063] In order to better understand the first embodiment, this embodiment describes the specific architecture of the controller in detail.

[0064] like Figure 2 As shown, the controller provided in this embodiment includes: a first judgment module, an internal reflux control module, a second judgment module and a drug addition control module.

[0065] The determination module is configured to determine whether the first nitrate nitrogen concentration is within a preset control range during each adjustment period. If not, the process jumps to the internal reflux control module. If so, it indicates that the current first nitrate nitrogen concentration does not need to be adjusted, and the internal reflux ratio does not need to be adjusted during the current adjustment period.

[0066] Specifically, the preset control interval is determined according to the specific equipment and design data of the water plant, and generally needs to be set in a reasonable and low range to ensure that the TN value of the water outlet of the water plant is less than the prescribed discharge standard.

[0067] The internal reflow control module is used to calculate the return nitrate nitrogen concentration of the sewage returning through the internal reflow pipe, and to calculate the target adjustment amount of the first nitrate nitrogen concentration; and to determine the adjusted internal reflow ratio based on the return nitrate nitrogen concentration and the target adjustment amount.

[0068] The second judgment module is configured to determine, within each adjustment cycle, whether the current second nitrate nitrogen concentration is greater than the internal control value of the third nitrate nitrogen concentration at the end of the rear anoxic tank. If so, the process jumps to the dosing control module. Specifically, the internal control value of the third nitrate nitrogen concentration is typically determined based on the internal control concentration of the water plant effluent TN. Preferably, the internal control value of the third nitrate nitrogen concentration is the difference between the internal control concentration of the water plant effluent TN and the current ammonia nitrogen concentration and the organic nitrogen concentration at the end of the rear anoxic tank, respectively, subtracted from the internal control concentration of the water plant effluent TN.

[0069] The dosing control module determines the target removal amount of nitrate nitrogen in the post-anoxic tank according to the second nitrate nitrogen concentration and the ammonia nitrogen concentration at the end of the post-anoxic tank; and determines the target amount of carbon source to be added to the post-anoxic tank according to the target removal amount.

[0070] The adjustment period is the time interval between each adjustment of the control parameters of the control component by the denitrification automatic control system. Specifically, the adjustment period can be 5 minutes to 3 hours, preferably 30 minutes to 2 hours, and most preferably 1 hour.

[0071] In a specific implementation of this embodiment, the internal reflux control module adjusts the internal reflux pipeline in the following manner:

[0072] The product of the current internal reflux ratio and the second nitrate nitrogen concentration is taken as the current reflux nitrate nitrogen concentration.

[0073] The difference between the current first nitrate nitrogen concentration and the preset internal control value of the first nitrate nitrogen concentration is used as the target adjustment amount.

[0074] The difference between the current reflow nitrate nitrogen concentration and (1+r) times the target adjustment amount is used as the first proportional factor; wherein r is the external reflow ratio of the five-stage Batumu sewage treatment process.

[0075] The sum of the current second nitrate nitrogen concentration and the target adjustment amount is used as a second proportional factor;

[0076] The ratio of the first proportional factor to the second proportional factor is used as the adjusted internal reflux ratio.

[0077] Preferably, the preset internal control value of the first nitrate nitrogen concentration can be determined based on the preset control interval of the first nitrate nitrogen concentration, and can specifically be the middle value of the preset control interval of the first nitrate nitrogen concentration. For example, if the preset control interval of the first nitrate nitrogen concentration is [A, B], the preset internal control value of the first nitrate nitrogen concentration is (A+B) / 2. That is, when the current first nitrate nitrogen concentration is lower than A, the internal reflux ratio is increased to increase the current first nitrate nitrogen concentration to a value close to (A+B) / 2 within the control interval [A, B]. When the current first nitrate nitrogen concentration is higher than B, the internal reflux ratio is decreased to decrease the current first nitrate nitrogen concentration to a value close to (A+B) / 2 within the control interval [A, B]. In this way, by increasing / decreasing the internal reflux ratio, the online value of the first nitrate nitrogen concentration meter returns to a position closer to the middle value within the control interval.

[0078] The internal reflux pipe is connected to the end of the front aerobic tank and the front end of the front anoxic tank, that is, connected to the two ends of the front coupling reaction zone composed of the front anoxic tank and the front aerobic tank, and is used to return part of the sewage at the end of the front aerobic tank to the front end of the front anoxic tank. The above-mentioned internal reflux control module uses the deviation between the current first nitrate nitrogen concentration at the end of the front anoxic tank and the internal control value as the target adjustment amount, and adjusts the internal reflux ratio of the internal reflux pipe based on the second nitrate nitrogen concentration at the front end of the rear anoxic tank (that is, the end of the front aerobic tank). The first nitrate nitrogen concentration and the second nitrate nitrogen concentration involved are both control parameters of the front coupling reaction zone composed of the front anoxic tank and the front aerobic tank. The overall calculation process does not involve the control parameters of the rear coupling reaction zone composed of the rear anoxic tank and the rear aerobic tank. Therefore, the control means of adjusting the internal reflux ratio independently controls the denitrification effect of the front coupling reaction zone, thereby achieving refined control of the front coupling reaction zone. Moreover, based on the deviation between the current first nitrate nitrogen concentration and the internal control value, the present application can achieve dynamic adjustment of the internal reflux ratio, so that the fluctuation range of the first nitrate nitrogen concentration tends to be stable, and the denitrification efficiency is simultaneously improved.

[0079] In another specific implementation of this embodiment, the dosing control module determines the target amount of carbon source to be added to the post-anoxic tank in the following manner:

[0080] The baseline target value is determined by subtracting the current ammonia nitrogen concentration at the end of the post-anoxic tank and the organic nitrogen concentration at the end of the post-anoxic tank from the preset internal control concentration of TN in the water plant effluent. The current ammonia nitrogen concentration at the end of the post-anoxic tank can be measured using an online ammonia nitrogen concentration meter. The organic nitrogen concentration at the end of the post-anoxic tank is an empirical value. Based on long-term operating data from sewage treatment plants, it generally has a certain range of values ​​for different sewage treatment plants in different seasons and under different influent loads.

[0081] The difference between the current second nitrate nitrogen concentration and the basic target value is used as the target removal amount of nitrate nitrogen in the post-anoxic tank.

[0082] The target carbon source amount is obtained by multiplying the target removal amount by the carbon source equivalent required to remove unit nitrate nitrogen by the carbon source used, and dividing it by the concentration of the carbon source agent used. The sum of the agent compensation amount required to eliminate the dissolved oxygen in the anoxic tank and the theoretical agent amount is used as the target carbon source amount.

[0083] That is, the amount of carbon source agent added to the post-anoxic tank = the target removal amount of nitrate nitrogen in the post-anoxic tank × the amount of carbon source agent required to remove unit nitrate nitrogen + the amount of carbon source agent required to consume dissolved oxygen in the influent of the post-anoxic tank.

[0084] Among them, the carbon source equivalent required for the carbon source used to remove unit nitrate nitrogen is an empirical value, which is related to the specific type of water plant and the type of carbon source agent used. Taking sodium acetate as a carbon source agent as an example, the pure sodium acetate carbon source equivalent required for unit nitrate nitrogen removal in daily urban sewage treatment plants is generally between 6mg and 8mg. The product of the target removal amount and the carbon source equivalent is the theoretical total amount of carbon source required to eliminate the target removal amount of nitrate nitrogen. In actual applications, the carbon source agent used is usually diluted, so the theoretical total amount of carbon source is divided by the concentration of the carbon source agent used to obtain the theoretical dosage of the carbon source agent. Among them, the concentration of the carbon source agent is generally measured in mass fraction.

[0085] The amount of reagent compensation required to eliminate the dissolved oxygen (DO) in the anoxic tank after elimination is also an empirical value, which is related to the specific type of water plant and the type of carbon source reagent used. Taking sodium acetate as a carbon source reagent as an example, the empirical value of the sodium acetate concentration required to eliminate a unit of dissolved oxygen is 2.56 mg / L.

[0086] The output end of the dosing pipeline is connected to the post-anoxic tank. The dosing control module uses the deviation (basic target value) between the current second nitrate nitrogen concentration at the end of the pre-anoxic tank and the internal control value of the third nitrate nitrogen concentration as the target removal amount, and determines the target carbon source amount based on the carbon source equivalent required to remove unit nitrate nitrogen using the carbon source, the concentration of the carbon source agent used, and the amount of agent compensation required to eliminate dissolved oxygen in the post-anoxic tank. The second nitrate nitrogen concentration, the organic nitrogen concentration at the end of the post-anoxic tank, and the ammonia nitrogen concentration at the end of the post-anoxic tank are all control parameters of the post-coupling reaction zone composed of the post-anoxic tank and the post-aerobic tank. Except for the second nitrate nitrogen concentration, which is a water quality parameter at the inlet of the post-coupling reaction zone, the overall calculation process does not involve the control parameters of the pre-coupling reaction zone. Therefore, the control method of adjusting the carbon source dosage can independently control the denitrification effect of the post-coupling reaction zone, thereby achieving refined control of the post-coupling reaction zone. Moreover, based on the deviation between the current second nitrate nitrogen concentration and the internal control value of the third nitrate nitrogen concentration, the present application can achieve precise control of the amount of carbon source input and effectively reduce the consumption of carbon source agents.

[0087] The controller provided in this embodiment, based on the aforementioned first judgment module, internal reflux control module, second judgment module, and dosing control module, can accurately and dynamically adjust the internal reflux ratio of the internal reflux pipeline and the amount of carbon source added to the rear anoxic tank based on independent pipelines according to the aforementioned parameter changes of each reaction tank, thereby improving denitrification efficiency and reducing carbon source consumption. The internal reflux control module and the dosing control module work together, both independently regulating and controlling the nitrate nitrogen concentration of the wastewater flowing through the front coupling reaction zone and the rear coupling reaction zone within each adjustment cycle, ensuring maximum denitrification efficiency.

[0088] It should be noted that the dosing control module provided in this application only involves the addition of carbon sources to the rear anoxic tank. However, in specific application scenarios, if the influent water quality fluctuates too much, resulting in the second nitrate nitrogen concentration being too high and exceeding the maximum treatment capacity of the rear anoxic tank, a carbon source can also be added to the front anoxic tank to ensure that the effluent TN value is lower than the prescribed emission standard.

[0089] In addition, in the third specific implementation of this embodiment, in order to cope with the load fluctuations on the post-anoxic tank caused by a sudden increase or decrease in the water inlet of the water plant, a dynamic correction module for dosing can also be integrated into the controller to ensure that the amount of carbon source added matches the actual demand.

[0090] Specifically, the dosing dynamic correction module is used to compensate and adjust the target carbon source amount based on the current water inflow of the water plant according to the following formula in each adjustment cycle to determine the final carbon source amount added to the post-anoxic tank;

[0091]

[0092] Among them, C f It represents the final amount of carbon source added to the post-anoxic tank;

[0093] C g It represents the target amount of carbon source added to the post-anoxic tank;

[0094] Q0 represents the current inflow flow of the water plant;

[0095] Q 设计 Indicates the designed inlet flow of the water plant;

[0096] α represents the correction coefficient, and its value range is [0.1, 0.7].

[0097] The correction factor is an empirical parameter that can be dynamically adjusted based on the real-time denitrification efficiency (calculated by the nitrate removal rate) to ensure that the carbon source dosage matches actual demand. The specific value of α can be obtained by fitting historical data. Preferably, the value of α is in the range of [0.2, 0.5].

[0098] In the above formula, Q0-Q 设计 Indicates the sudden increase / decrease of water inflow to the water plant, (Q0-Q 设计 ) / Q 设计 It represents the sudden increase / decrease rate of the water inlet of the water plant. The sudden increase / decrease rate of the water inlet of the water plant is integrated with the above-mentioned correction coefficient α. When the correction coefficient α is determined, the final amount of carbon source added to the post-anoxic tank is dynamically adjusted according to the sudden increase / decrease rate of the water inlet of the water plant on the basis of the target carbon source amount, so as to further improve the precise control of the carbon source input amount and reduce the waste of carbon source agents.

[0099] Example 3

[0100] Based on the denitrification automatic control systems provided in the above-mentioned embodiments 1 and 2, a denitrification automatic control method for a five-stage Batumu sewage treatment process is provided, as follows:

[0101] This embodiment provides a denitrification automatic control method for a five-stage Batunfu sewage treatment process. A portion of the sewage at the end of the front aerobic tank is returned to the front end of the front anoxic tank via an internal return pipe connected to the end of the front aerobic tank and the front end of the front anoxic tank. The internal return ratio of the internal return pipe is controlled based on the first nitrate nitrogen concentration at the end of the front anoxic tank and the second nitrate nitrogen concentration at the front end of the rear anoxic tank. A carbon source is added to the rear anoxic tank via a dosing pipe whose output end is connected to the rear anoxic tank. The dosing amount of the dosing pipe is controlled based on the second nitrate nitrogen concentration at the front end of the rear anoxic tank, the organic nitrogen concentration at the end of the rear anoxic tank, the ammonia nitrogen concentration at the end of the rear anoxic tank, and a preset internal control concentration value of TN of the water plant effluent.

[0102] Taking a 20,000-ton / day sewage treatment plant using the five-stage Batum process as an example, the specific steps are as follows:

[0103] 1. Device configuration

[0104] like Figure 3 As shown, the internal reflux pipe is provided with an internal reflux pump and an internal reflux flow meter; the dosing pipe is provided with a carbon source container, a metering pump and a dosing pump; the front end of the front aerobic tank is provided with an inlet flow meter for measuring the current inlet flow Q0 of the water plant; the end of the front anoxic tank is provided with a first nitrate nitrogen concentration meter for collecting the first nitrate nitrogen concentration The front end of the post-anoxic tank is provided with a second nitrate nitrogen concentration meter for collecting the second nitrate nitrogen concentration. The end of the post-anoxic tank is provided with an ammonia nitrogen concentration meter for collecting the ammonia nitrogen concentration NH3_N at the end of the post-anoxic tank. 后缺末 The carbon source agent stored in the carbon source container is sodium acetate solution (also known as sodium acetate, CH3COONa), and the concentration of the sodium acetate solution is 25% (mass fraction).

[0105] The controller is respectively connected to the internal reflux pump, the internal reflux flow meter, the metering pump, the dosing pump, the water inlet flow meter, the first nitrate nitrogen concentration meter, the second nitrate nitrogen concentration meter and the ammonia nitrogen concentration meter to collect corresponding real-time data and control the operating frequency of the internal reflux pump and the dosing pump, thereby controlling the internal reflux ratio of the internal reflux pump and the amount of carbon source added.

[0106] 2. Parameter configuration

[0107] First nitrate nitrogen concentration at the end of the front anoxic pool Control range: It is controlled in a reasonable and low range according to the design value of the sewage treatment plant, and is set to 1-4 mg / L in this embodiment.

[0108] Based on the above first nitrate nitrogen concentration The control range of the first nitrate nitrogen concentration can be set to the preset internal control value Set to the middle value of the control interval:

[0109] The internal control value of the third nitrate nitrogen concentration at the end of the post-anoxic tank: the ammonia nitrogen concentration value NH3-N and the organic nitrogen concentration value TON of the post-anoxic tank must be considered at the same time 后缺末 To ensure that the post-hypoxia terminal TN ( NH3_N 后缺末 , and TON, where the lower concentration of nitrite nitrogen is generally not considered The current concentration of secondary nitrate nitrogen at the inlet of the post-anoxic tank is stable and meets the discharge standard of the water leaving a certain safety margin. Subtract the internal control value of the third nitrate nitrogen concentration at the end of the post-anoxic tank to get the target nitrate nitrogen removal amount in the post-anoxic tank. If the discharge standard TN of the water is 15mg / L, in order to ensure the safety and stability of the effluent water quality, the internal control concentration value of TN of the water plant effluent is TN 出水内控值 Set to 13.5 mg / L, NH3_N 后缺末 =0.2mg / L (online instrument display value), TON 后缺末 =0.8 mg / L (empirical value determined by long-term monitoring), then the internal control value of the third nitrate nitrogen concentration at the end of the post-anoxic tank is:

[0110]

[0111] 3. Actual control process

[0112] In one control cycle, the external reflux ratio r=70% and the internal reflux ratio R are directly measured by the instrument or further calculated based on real-time data. 调整前 = 280%, the current primary nitrate nitrogen concentration at the end of the front anoxic pool The current second nitrate nitrogen concentration at the front end of the post-anoxic pool The working steps of the controller based on each module include the following steps S1 to S5:

[0113] S1. The first judgment module judges the current first nitrate nitrogen concentration If the first nitrate nitrogen concentration is not within the preset control range of 1-4 mg / L, the process jumps to the internal reflux control module to adjust the internal reflux ratio.

[0114] S2, the internal reflux control module uses the product of the current internal reflux ratio and the second nitrate nitrogen concentration as the current reflux nitrate nitrogen concentration

[0115]

[0116] The internal reflux control module uses the difference between the current first nitrate nitrogen concentration and the preset internal control value of the first nitrate nitrogen concentration as the target adjustment amount.

[0117]

[0118] The internal reflux control module converts the current reflux nitrate nitrogen concentration The difference from (1+r) times the target adjustment amount As the first proportional factor; the current second nitrate nitrogen concentration Adjustment to target The sum of the first proportional factor and the second proportional factor is used as the adjusted internal reflux ratio R 调整后 :

[0119]

[0120] It should be noted that the operating frequency of the internal reflux pump is linearly related to the internal reflux ratio. After determining the adjusted internal reflux ratio, the internal reflux ratio of the internal reflux pipeline can be adjusted accordingly by increasing or decreasing the operating frequency of the internal reflux pump.

[0121] S3. The second judgment module judges the current second nitrate nitrogen concentration Greater than the internal control value of the third nitrate nitrogen concentration at the end of the post-anoxic tank Jump to Dosing Control Module.

[0122] S4, the dosing control module sets the preset internal control concentration value TN of the water plant outlet water 出水内控值 Subtract the current ammonia nitrogen concentration NH3_N at the end of the anoxic pool in sequence 后缺末 and the organic nitrogen concentration TON at the end of the post-anoxic tank, as the internal control value of the third nitrate nitrogen concentration at the end of the post-anoxic tank The current second nitrate nitrogen concentration and the third internal control value of nitrate nitrogen concentration The difference is used as the target removal amount of nitrate nitrogen in the post-anoxic tank.

[0123]

[0124] The dosing control module removes the target amount The carbon source equivalent K required to remove unit nitrate nitrogen from the carbon source used 碳源 The product of ω and ω divided by the concentration of the carbon source agent used 碳源浓度 , get the theoretical dosage, and eliminate the dosage C required to compensate for the dissolved oxygen in the anoxic tank DO补偿 The sum of the theoretical dosage is taken as the target carbon source amount C g :

[0125]

[0126] In the above formula, the carbon source equivalent K required for sodium acetate to remove unit nitrate nitrogen is 碳源 The empirical value range of is 6mg-10mg, and in this embodiment, it is specifically taken as 6mg, that is, the amount of pure sodium acetate required to remove unit nitrate nitrogen is 6mg, and the required concentration ω 碳源浓度 The amount of sodium acetate with a concentration of 25% (mass fraction) is 24 mg. The amount of reagent required to eliminate the dissolved oxygen in the anoxic tank is C DO补偿 It is an empirical value. The empirical value determined by the sewage treatment plant in this embodiment according to historical operation data is 2 mg / L.

[0127] S5, the dynamic correction module of the dosing is based on the current water inlet flow Q0 of the water plant, and according to the following formula, take α=0.3, and adjust the target carbon source amount C g Make compensation adjustments to determine the final amount of carbon source added to the post-anoxic tank C f :

[0128]

[0129] Among them, (Q0-Q 设计 ) / Q 设计 According to the current water inlet flow Q0 of the water plant and the designed water inlet flow Q 设计 OK, indicating the sudden increase or decrease rate of the current water inflow.

[0130] Based on the above final carbon source amount, the operating frequency of the dosing pump can be controlled to correspondingly control the amount of carbon source added to the post-anoxic tank.

[0131] Compared with the target carbon source amount of 62 mg / L calculated by the dosing control module, the dosing dynamic correction module determines that the final carbon source amount added to the rear anoxic tank is 58 mg / L after dynamic adjustment based on the current water inlet flow, reducing the carbon source consumption by 6%.

[0132] The automatic denitrification control method provided in this embodiment is based on the controller and the above-mentioned control components. It can automatically control the above-mentioned parameter changes of each reaction tank respectively, and based on the independent pipelines, accurately and dynamically adjust the internal reflux ratio of the internal reflux pipe and the amount of carbon source added to the rear anoxic tank respectively, thereby improving the denitrification efficiency and reducing the carbon source consumption. At the same time, the two are independently regulated, and in each adjustment cycle, the nitrate nitrogen concentration of the sewage flowing through the front coupling reaction zone and the rear coupling reaction zone is coordinated to ensure the maximization of the denitrification efficiency. Moreover, this fully automated control method reduces the degree of manual intervention and significantly reduces operating costs.

[0133] Since the systems / devices described in the above embodiments of this application are systems / devices used to implement the methods of the above embodiments of this application, those skilled in the art will be able to understand the specific structures and variations of these systems / devices based on the methods described in the above embodiments of this application, and therefore, they will not be described in detail here. All systems / devices used in the methods of the above embodiments of this application fall within the scope of protection to be provided by this application.

[0134] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0135] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present application. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions.

[0136] It should be noted that in the claims, any reference signs placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The present application may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In claims enumerating several means, several of these means may be embodied by the same hardware. The use of the words first, second, third etc. is for convenience only and does not indicate any order. These words may be understood as part of the component name.

[0137] In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0138] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments after learning the basic creative concepts. Therefore, the claims should be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0139] Obviously, those skilled in the art may make various modifications and variations to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations fall within the scope of the claims of this application and their equivalents, this application shall also include these modifications and variations.

Claims

1. A denitrification automatic control system for a five-stage Batunfu sewage treatment process, wherein the five-stage Batunfu sewage treatment process is implemented based on multiple reaction tanks, wherein the reaction tanks include an anaerobic tank, a front anoxic tank, a front aerobic tank, a rear anoxic tank, and a rear aerobic tank connected in sequence, characterized in that: The automatic control system includes a controller, which regulates the denitrification efficiency of the five-stage Batunfu sewage treatment process through a regulating component arranged on a plurality of reaction tanks; The control components include: An internal return pipe is connected to the end of the front aerobic tank and the front end of the front anoxic tank, and is used to return part of the sewage at the end of the front aerobic tank to the front end of the front anoxic tank; A dosing pipeline, the output end of which is connected to the post-anoxic tank and is used to add a carbon source to the post-anoxic tank; The controller is communicatively connected to the internal reflux pipe and the dosing pipe, respectively, and is used to control the internal reflux ratio of the internal reflux pipe according to the first nitrate nitrogen concentration at the end of the front anoxic tank and the second nitrate nitrogen concentration at the front end of the rear anoxic tank; and to control the amount of carbon source added to the rear anoxic tank according to the second nitrate nitrogen concentration at the front end of the rear anoxic tank, the organic nitrogen concentration at the end of the rear anoxic tank, the ammonia nitrogen concentration at the end of the rear anoxic tank and the preset internal control concentration value of the water plant effluent TN.

2. The denitrification automatic control system according to claim 1, characterized in that: The controller includes: a first judgment module and an internal reflux control module; The first judgment module is used to judge whether the current first nitrate nitrogen concentration is within a preset control range in each adjustment period, and if not, jump to the internal reflux control module; The internal reflow control module is used to calculate the return nitrate nitrogen concentration of the sewage returning through the internal reflow pipe, and to calculate the target adjustment amount of the first nitrate nitrogen concentration; and to determine the adjusted internal reflow ratio based on the return nitrate nitrogen concentration and the target adjustment amount.

3. The denitrification automatic control system according to claim 2, characterized in that: In the internal reflow control module, calculating the current reflow nitrate nitrogen concentration of the reflow sewage in the internal reflow pipe and calculating the target adjustment amount of the first nitrate nitrogen concentration include: The product of the current internal reflux ratio and the second nitrate nitrogen concentration is used as the current reflux nitrate nitrogen concentration; The difference between the current first nitrate nitrogen concentration and the preset internal control value of the first nitrate nitrogen concentration is used as the target adjustment amount.

4. The denitrification automatic control system according to claim 2, characterized in that: In the internal reflux control module, determining the adjusted internal reflux ratio according to the reflux nitrate nitrogen concentration and the target adjustment amount includes: The difference between the current reflux nitrate nitrogen concentration and (1 + r) times the target adjustment amount is used as the first proportional factor; where r is the external reflux ratio of the five-stage Batumu wastewater treatment process; The sum of the current second nitrate nitrogen concentration and the target adjustment amount is used as a second proportional factor; The ratio of the first proportional factor to the second proportional factor is used as the adjusted internal reflux ratio.

5. The denitrification automatic control system according to claim 2, characterized in that: The controller further includes: a second judgment module and a drug addition control module; The second judgment module is used to judge whether the current second nitrate nitrogen concentration is greater than the internal control value of the third nitrate nitrogen concentration at the end of the rear anoxic tank in each adjustment period, and if so, jump to the dosing control module; The dosing control module is used to determine the target removal amount of nitrate nitrogen in the post-anoxic tank based on the second nitrate nitrogen concentration, the organic nitrogen concentration at the end of the post-anoxic tank, the ammonia nitrogen concentration at the end of the post-anoxic tank and the preset internal control concentration value of the water plant effluent TN; and determine the target amount of carbon source to be added to the post-anoxic tank based on the target removal amount.

6. The denitrification automatic control system according to claim 5, characterized in that: In the dosing control module, the target removal amount of nitrate nitrogen in the post-anoxic tank is determined according to the second nitrate nitrogen concentration, the organic nitrogen concentration at the end of the post-anoxic tank, the ammonia nitrogen concentration at the end of the post-anoxic tank, and the preset internal control concentration value of TN of the water plant effluent, including: The preset internal control concentration value of TN of the water plant effluent is subtracted in sequence from the current ammonia nitrogen concentration at the end of the post-anoxic tank and the organic nitrogen concentration at the end of the post-anoxic tank as the basic target value; The difference between the current second nitrate nitrogen concentration and the basic target value is used as the target removal amount of nitrate nitrogen in the post-anoxic tank.

7. The denitrification automatic control system according to claim 5, characterized in that: In the dosing control module, the target amount of carbon source to be added to the post-anoxic tank is determined according to the target removal amount, including: The target carbon source amount is obtained by multiplying the target removal amount by the carbon source equivalent required to remove unit nitrate nitrogen by the carbon source used, and dividing it by the concentration of the carbon source agent used. The sum of the agent compensation amount required to eliminate the dissolved oxygen in the anoxic tank and the theoretical agent amount is used as the target carbon source amount.

8. The denitrification automatic control system according to claim 5, characterized in that: The controller further includes: The dynamic correction module for dosing is used to compensate and adjust the target carbon source amount based on the current water inflow of the water plant according to the following formula in each adjustment cycle to determine the final amount of carbon source added to the post-anoxic tank; Among them, C f It represents the final amount of carbon source added to the post-anoxic tank; C g It represents the target amount of carbon source added to the post-anoxic tank; Q0 represents the current inflow flow of the water plant; Q 设计 Indicates the designed inlet flow of the water plant; α represents the correction coefficient, and its value range is [0.1, 0.7].

9. The denitrification automatic control system according to claim 1, characterized in that: The control component also includes: An internal reflux pump and an internal reflux flow meter provided on the internal reflux pipeline; and / or, A carbon source container, a metering pump and a dosing pump are provided on the dosing pipeline; and / or, A water inlet flow meter provided at the front end of the front aerobic tank; and / or, a first nitrate nitrogen concentration meter provided at the end of the front anoxic tank; and / or, a second nitrate nitrogen concentration meter provided at the front end of the post-anoxic tank; and / or An ammonia nitrogen concentration meter is provided at the end of the post-anoxic tank.

10. A denitrification automatic control method for a five-stage Batumu sewage treatment process, characterized in that: The automatic denitrification control method is based on the automatic denitrification control system of the five-stage Batunfu sewage treatment process according to any one of claims 1 to 9, and controls the denitrification efficiency of the five-stage Batunfu sewage treatment process.

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