Ozone intelligent dosing control system and method in sewage treatment

Abstract

The present application relates to sewage treatment technical field, specifically to a kind of ozone intelligent dosing control system and method in sewage treatment, system includes ozone oxidation pond, ozone generator, online monitoring device and control device, ozone oxidation pond includes first oxidation pond and second oxidation pond;First valve is set in the water inlet end of first oxidation pond, and second valve and third valve are set in the water inlet and outlet end of second oxidation pond respectively, and water inlet mode, drainage mode and processing mode are set according to the on-off state of first valve, second valve and third valve, integrated water inlet, drainage work and sewage oxidation degradation work.The present application detects BOD and COD data of inlet and outlet water by setting online monitoring device in sewage treatment pond, accurately calculates ozone dosage according to sewage flow and BOD / COD data in sewage, feeds back to control device, controls ozone generator to accurately put ozone, avoids ozone underdosing or overdose, reduces system operation cost, and guarantees the overall operation effect of system.

Description

TECHNICAL FIELD

[0001] The present application relates to the sewage treatment technical field, and particularly relates to an ozone intelligent adding control system and method in sewage treatment. BACKGROUND

[0002] Ozone (O3) technology is a kind of efficient and environmentally friendly oxidation technology, which is widely used in sewage treatment systems. Due to the change of water quality on the project site, in the prior art, the ozone is manually controlled or quantitatively added according to the detection results of water quantity and water quality.

[0003] The quantitative addition cannot adjust the ozone addition amount in real time according to the change of water quantity and water quality, which leads to excessive or insufficient addition of ozone, and affects the water outlet indicators. For example, excessive addition of ozone will lead to ozone dissipation and too high ozone concentration in the water outlet, which will have adverse effects on the surrounding environment and the on-site workers. In addition, manual addition has hysteresis, which can easily lead to the purified water not meeting the expected indicators.

[0004] Based on the problems in the prior art, the present application provides an ozone intelligent adding control system and method in sewage treatment. SUMMARY

[0005] The purpose of the present application is to provide an ozone intelligent adding control system and method in sewage treatment, so as to solve the technical problems of insufficient or excessive addition of ozone in the prior art.

[0006] The technical scheme of the present application is: an ozone intelligent adding control system in sewage treatment, comprising:

[0007] An ozone oxidation tank comprising a first oxidation tank and a second oxidation tank;

[0008] A first valve installed at the water inlet end of the ozone oxidation tank for controlling the water inlet of the first oxidation tank;

[0009] A second valve installed between the first oxidation tank and the second oxidation tank for controlling the water inlet of the second oxidation tank;

[0010] A third valve installed at the water outlet end of the second oxidation tank for discharging the water body after oxidation degradation;

[0011] An ozone generator for adding ozone to the ozone oxidation tank;

[0012] An online monitoring device for online monitoring of the pollutant concentration in sewage;

[0013] A control device electrically connected with the online monitoring device and the ozone generator;

[0014] According to the current water pollutant concentration state obtained by the online monitoring device, an instruction is sent to the ozone generator to control the ozone dosage in the ozone oxidation tank; wherein the pollutant concentration state is the obtained BOD and COD concentration data;

[0015] According to the current sewage volume in the first and second oxidation tanks, the conduction or closing of the first and second valves is controlled; and according to the on-off state of the first, second and third valves, the water inlet mode, water discharge mode and treatment mode are set to integrate the water inlet, water discharge and pollutant oxidation and degradation work.

[0016] Preferably, the normal state of the first valve is always open to maintain water inlet;

[0017] The second valve is opened and the third valve is closed to set the water inlet mode and water is inlet into the second oxidation tank; both the second and third valves are closed to set the treatment mode and wait for the oxidation and degradation of pollutants in the second oxidation tank; the second valve is closed and the third valve is opened to set the water discharge mode, and the water body in the second oxidation tank is oxidized and the purified water body is discharged; in a cycle, the water inlet mode, treatment mode and water discharge mode are cycled;

[0018] In the cycling process, the time for completing the water inlet mode in one cycle is a unit water inlet time, and the time for the water discharge mode is set to be equal to the time for the water inlet mode;

[0019] In a cycle, the water body volume in the first oxidation tank exceeds half of the volume of the ozone oxidation tank in the next cycle of water inlet mode, treatment mode and water discharge mode, so the first valve is closed, the remaining water body in the ozone oxidation tank is purified and treated, and then the first valve is controlled to be opened for a new cycle of purification.

[0020] Preferably, in a cycle, the time for the water inlet mode of adjacent cycles is equal, and the time for the water discharge mode of adjacent cycles is equal;

[0021] In each cycle, at the beginning of the water inlet mode when the second valve is opened, the water body in the first oxidation tank is simultaneously collected as a carrier to obtain a water sample detection sample;

[0022] When the water inlet mode is completed, the water body volume in the second oxidation tank is equal to the water inlet volume according to the unit water inlet time; the second valve is closed, and according to the pollutant concentration determined by the online monitoring device based on the detection sample, ozone is added to the second oxidation tank; after a period of time, the treated water body in the second oxidation tank is discharged after waiting for degradation.

[0023] Preferably, the time used in the subsequent water feeding mode is greater than the time used in the adjacent previous water feeding mode, and the water feeding amount in the subsequent water feeding mode is iteratively increased by one processing time corresponding water feeding amount, and the corresponding water discharging mode time is iteratively updated and synchronously updated;

[0024] When the water feeding mode is completed, the water volume in the second oxidation tank is equal to the water volume fed in a unit time according to the set flow rate; the second valve is closed, and a water sample is obtained from the water body in the first oxidation tank as a detection sample; ozone is added to the second oxidation tank according to the pollutant concentration determined by the online monitoring device based on the detection sample; after a period of time, degradation is completed, and the treated water in the second oxidation tank is discharged.

[0025] An ozone intelligent adding control method in sewage treatment, used for realizing the ozone intelligent adding control system in sewage treatment, comprising:

[0026] Controlling normal water feeding of the first oxidation tank of the ozone oxidation tank;

[0027] Setting a time point for obtaining a water sample, and a water feeding time point and a water discharging time point of the second oxidation tank;

[0028] Determining the pollutant concentration based on the water body in the first oxidation tank as a sample, and adding ozone to the second oxidation tank for oxidation degradation based on the pollutant concentration detection result;

[0029] When the water volume of the first oxidation tank of the ozone oxidation tank reaches half of the volume of the ozone oxidation tank, the first oxidation tank stops water feeding, and after the remaining water in the oxidation tank is completely purified, the first oxidation tank is controlled to feed water normally again for a new round of purification cycle.

[0030] Preferably, in the process of one round of purification cycle, the time interval between the normal water feeding of the first oxidation tank and the opening time point and the pause time point of the second oxidation tank is the water feeding time, and the water sample in the first oxidation tank is synchronously obtained when the second oxidation tank starts to feed water;

[0031] The ozone adding amount is calculated based on the given pollutant concentration detection result, the time interval between the ozone adding time point and the opening time point of the second oxidation tank is the processing time, and the water discharging time of the second oxidation tank is equal to the water feeding time of the second oxidation tank.

[0032] Preferably, in the process of one round of purification cycle, the second oxidation tank water feeding, oxidation treatment and water discharging operations are performed for multiple rounds, and the operation mode cycle of each round is represented as:

[0033] The water feeding time of the Nth round of operation mode cycle is , the water discharging time is , and the processing time is , the water in the first oxidation tank is discharged, and the residual water in the first oxidation tank is equal to the water inflow in the time period, from the beginning of the current purification cycle to the end of the Nth operation mode cycle, and the time required for completion is ; wherein N is a positive integer;

[0034] If it is predicted that the N+1th operation mode cycle will be completed, and the water in the first oxidation tank exceeds half of the volume of the ozone oxidation tank, then at the completion of the Nth operation mode cycle, the water inflow into the first oxidation tank is stopped, the first oxidation tank is connected with the second oxidation tank, the concentration of pollutants in the current ozone oxidation tank is detected, ozone is added according to the concentration of pollutants, and after the oxidation and degradation treatment is completed, the water in the tank is completely discharged.

[0035] Preferably, during one purification cycle, multiple rounds of water inflow into the second oxidation tank, oxidation treatment and water discharge operation are performed, and each round of operation mode cycle is represented as:

[0036] the water inflow time of the Mth operation mode cycle is , the treatment time is , the water discharge time is , the water in the second oxidation tank is discharged, and the second operation mode cycle is completed, and the residual water in the first oxidation tank is the water inflow corresponding to the time period, and the time required for completion is ; wherein M is a positive integer;

[0037] If it is predicted that the M+1th operation mode cycle will be completed, and the water in the first oxidation tank exceeds half of the volume of the ozone oxidation tank, then at the completion of the Mth operation mode cycle, the water inflow into the first oxidation tank is stopped, the first oxidation tank is connected with the second oxidation tank, the concentration of pollutants in the current ozone oxidation tank is detected, ozone is added and the oxidation and degradation treatment is completed, and the water in the tank is completely discharged.

[0038] Preferably, if the back end of the oxidation tank is directly discharged, then according to the concentration of COD, the ozone dosage is controlled; the ozone dosage satisfies the constraint formula: ;

[0039] wherein represents the ozone dosage; a is a variable coefficient, 0.9-1.1; b represents the flow of wastewater to be treated; X represents the concentration of COD to be degraded.

[0040] Preferably, if the back end of the oxidation tank is a biochemical treatment process, then according to the change of BOD5 / COD obtained by detection, the ozone dosage is adjusted;

[0041] The BOD5 / COD concentration content comparison value is set to 0.3;

[0042] When the BOD5 / COD concentration is greater than 0.3, the ozone dosage is reduced, and the ozone dosage is not greater than the theoretical addition amount for reducing the pollutant concentration to the preset value;

[0043] When the BOD5 / COD concentration is less than 0.3, the ozone dosage is increased, and the ozone dosage is not less than the theoretical addition amount for reducing the pollutant concentration to the preset value.

[0044] Compared with the prior art, the advantages of the present application are:

[0045] (1) The present application detects the COD and BOD data of the inlet and outlet water by setting an online monitoring device in the sewage treatment tank, accurately calculates the ozone dosage according to the sewage volume and the BOD / COD data in the sewage, feeds back to the control device, and controls the ozone generator to accurately add ozone, thereby avoiding insufficient or excessive ozone addition, reducing the system operation cost, and ensuring the overall operation effect of the system.

[0046] (2) The oxidation of organic matter is carried out in the ozone oxidation tank, and according to the different treatment requirements of water quality, the ozone oxidation tank can select direct contact oxidation and catalytic oxidation.

[0047] If the back end is directly discharged, only the outlet water COD condition is detected, the PLC control system is adjusted to adjust the ozone dosage, and the outlet water can meet the discharge standard.

[0048] If the back end is a microbial biochemical process, the biodegradability of wastewater needs to be improved, the BOD5 / COD concentration ratio index is controlled at the end, the front-end ozone dosage is adjusted, excessive degradation of organic matter or excessive addition of ozone is avoided, energy saving and consumption reduction of the system are realized; according to the change of BOD5 / COD, the ozone dosage is adjusted in real time, and after the biochemical property is improved, it enters the subsequent biochemical system, which is helpful for the microorganisms to better degrade the organic matter in the water.

[0049] Strong adaptability, real-time adjustment of ozone dosage according to different water quantity and water quality, and guarantee of outlet water effect of different water quality.

[0050] (3) Through intelligent addition, the automation degree is high, the human operation of the ozone addition system is reduced, and the overall operation efficiency of the system is improved.

[0051] (4) The application takes the first oxidation tank of the ozone oxidation tank as a pollutant concentration detection sample, controls the water inlet and drainage of the second oxidation tank, and sets the system operation process as a water inlet mode, a treatment mode and a drainage mode. Different from the mode of one-time filling of the ozone oxidation tank and one-time addition of ozone, the application shortens the unit water inlet time / drainage time, realizes high-frequency low-flow batch cycle treatment, can treat more sewage in the same time, and improves the sewage treatment efficiency. Each sewage cycle takes less time, and a plurality of batch cycle treatments are arranged in each complete cycle. When a fault occurs, more "emptying" treatment nodes can be provided, which is more conducive to maintaining the sewage treatment system. BRIEF DESCRIPTION OF DRAWINGS

[0052] The application will be further described below in combination with the drawings and examples:

[0053] Figure 1 The system block diagram of the ozone intelligent addition control system described in the application is shown in the figure;

[0054] Figure 2 The working mode flowchart of the ozone intelligent addition control system described in the application is shown in the figure;

[0055] Figure 3 The local plane schematic diagram of the ozone oxidation tank in the sewage treatment equipment provided in the application is shown in the figure;

[0056] Figure 4 The flowchart of the ozone intelligent addition control method described in the application is shown in the figure;

[0057] Figure 5 The running state schematic diagram of the intelligent addition control system in the example 1 in the application in one running cycle is shown in the figure;

[0058] Figure 6 The comparative parameter schematic diagram of the example 1 and the comparative example for treating sewage under the condition of multiple running cycles in the example 1 in the application is shown in the figure;

[0059] Figure 7 The running state schematic diagram of the intelligent addition control system in the example 2 in the application in one running cycle is shown in the figure;

[0060] Figure 8 The comparative parameter schematic diagram of the example 2 and the comparative example for treating sewage in one week in the example 2 in the application is shown in the figure;

[0061] 1, the first valve; 2, the second valve; 3, the third valve; 4, the ozone generator; 5, the online monitoring device; 6, the control device; 7, the ozone oxidation tank; 8, the water inlet adjusting tank; 9, the water outlet monitoring tank;

[0062] 71, the first oxidation tank; 72, the second oxidation tank. Detailed Implementation

[0063] The present invention will be further described in detail below with reference to specific embodiments:

[0064] like Figure 1 As shown, an intelligent ozone dosing and control system for wastewater treatment includes:

[0065] The system comprises an influent equalization tank 8, an ozone oxidation tank 7, and an effluent monitoring tank 9. Wastewater pretreatment, including pH adjustment and sedimentation / impurity removal, is performed in the influent equalization tank 8. The pretreated wastewater is then transported to the ozone oxidation tank for pollutant degradation, primarily through microbial degradation.

[0066] Combined with appendix Figure 3 As shown, the ozone oxidation tank 7 includes a first oxidation tank 71 and a second oxidation tank 72; a first valve 1 is installed at the inlet end of the first oxidation tank 71 (i.e., the inlet end of the ozone oxidation tank) to control the flow of water into the first oxidation tank 71; a second valve 2 is installed between the second oxidation tank 72 and the first oxidation tank 71 to control the flow of water into the second oxidation tank 72; a third valve 3 is installed at the outlet end of the second oxidation tank 72 to control the flow of water out of the second oxidation tank 72, and the water purified by the ozone oxidation tank 7 is discharged into the effluent monitoring tank 9 for temporary storage.

[0067] The first valve 1, the second valve 2, and the third valve 3 are each one of the following: butterfly valve, gate valve, and check valve.

[0068] To intelligently control the ozone dosage, an ozone generator 4, an online monitoring device 5, and a control device 6 are installed. The control device 6 is electrically connected to both the online monitoring device 5 and the ozone generator 4. Based on the pollutant concentration in the wastewater detected by the online monitoring device 5, the control device 6 determines the current ozone dosage and instructs the ozone generator 4 to add ozone to the ozone oxidation tank 7.

[0069] The control device 6 uses a PLC controller to calculate the ozone dosage and feeds it back to the ozone generator 4 to control the ozone dosage. The online monitoring device 5 includes a flow meter, a BOD sensor, a COD sensor, an online BOD (an indicator of the degree of organic pollution in water) measuring device, and an online COD (chemical oxygen demand) measuring device. This invention expresses the concentration of pollutants in wastewater through BOD and COD levels.

[0070] The flow meter is used to detect the volume of water in the first oxidation tank 71 and the second oxidation tank 72; the online BOD measuring device measures the BOD concentration online based on the sample information obtained by the BOD sensor; the online COD measuring device measures the COD concentration online based on the sample information obtained by the COD sensor.

[0071] The principle of the on-line monitoring and analysis method of BOD, COD and BOD / COD is introduced as follows:

[0072] BOD is detected by a microbial sensor method, which is based on the principle of a microbial sensor. A recognition element prepared by microorganisms that can easily react with organic pollutants in water is used. The changes generated in the reaction are converted into electrical signals or digital signals by a signal conversion element, and the BOD concentration value is output after signal processing.

[0073] The BOD on-line analysis method is as follows: glucose-glutamic acid standard solution is used to prepare standard solutions containing BOD of 0 mg / L, 5 mg / L, 10 mg / L, 25 mg / L and 50 mg / L. The working curve is drawn according to the potential difference (or current difference) corresponding to different concentrations of standard solutions. Then, under the same conditions, the water sample BOD is determined by feeding the sample pump to the on-line equipment.

[0074] The COD on-line analysis method is as follows: potassium dichromate oxidation method is used. Under high temperature (165°C) and acidic conditions, potassium dichromate is used as an oxidizing agent to oxidize organic matter in water. The COD value is calculated by measuring the change of potassium dichromate by fitting curve spectrophotometry.

[0075] The results of BOD / COD are obtained by calculating the data of BOD and COD monitored on-line.

[0076] Specifically, the first valve 1, the second valve 2 and the third valve 3 control the water inlet and outlet state of the ozone oxidation tank 7. The intelligent control process is set to three working modes, i.e. water inlet mode, water outlet mode and treatment mode. According to the set water inlet mode, water outlet mode and treatment mode, the integrated system controls the water inlet and outlet work and the pollutant oxidation and degradation control work, avoids insufficient or excessive ozone addition, saves energy consumption and reduces cost.

[0077] The logic diagram of the system running according to the three working modes is shown in FIG. 2. Figure 2 The principle is as follows:

[0078] The normal state of the first valve 1 is always open to keep the water inlet.

[0079] The second valve 2 is opened and the third valve 3 is closed, which is set to the water inlet mode to inlet water into the second oxidation tank 72.

[0080] The second valve 2 and the third valve 3 are both closed, which is set to the treatment mode to add ozone and wait for the completion of the oxidation and degradation of pollutants in the second oxidation tank 72.

[0081] The second valve 2 is closed and the third valve 3 is opened, which is set to the water outlet mode to discharge the purified water body after the oxidation of the water body in the second oxidation tank 72.

[0082] The water inlet mode, the treatment mode and the water discharge mode are cycled; if the water volume in the first oxidation tank 71 reaches half of the volume of the ozone oxidation tank, the first valve 1 is closed, the remaining water volume in the ozone oxidation tank 7 (including the first oxidation tank 71 and the second oxidation tank 72) is treated completely, and then the first valve 1 is controlled to be opened to start a new cycle of treatment.

[0083] In the water inlet mode, the water volume in the second oxidation tank 72 is equal to the water volume that is inletted in a unit time according to the set flow rate; in the case that the first valve 1 is kept in the open state and the second valve 2 is kept in the open state, the volume in the first oxidation tank 71 remains unchanged, and in this case, the water inletted into the first oxidation tank 71 by default enters the second oxidation tank 72, that is, the water flow rate of the first oxidation tank 71 entering the first oxidation tank 71 is equal to the water flow rate of the first oxidation tank 71 entering the second oxidation tank 72.

[0084] The second valve 2 is closed, and a water sample is taken from the water in the first oxidation tank 71 as a detection sample, the pollutant concentration is determined based on the detection sample by the online monitoring device 5, and ozone is added to the second oxidation tank 72; after a period of time, the degradation is completed, and the treated water in the second oxidation tank 72 is discharged.

[0085] According to the operation logic of the above-mentioned system, an ozone intelligent adding control method for sewage treatment is provided, which is used to realize an ozone intelligent adding control system for sewage treatment, and the accompanying drawings are as follows: Figure 4 The contents of the method are as follows:

[0086] The first oxidation tank 71 of the ozone oxidation tank 7 is controlled to be normally water-inletted, the water inlet time point and the water discharge time point of the second oxidation tank 72 of the ozone oxidation tank are set, and the time interval between the water inlet opening time point and the water inlet suspension time point of the second oxidation tank 72 is set as the water inlet time.

[0087] When the second oxidation tank 72 is opened for water inlet, a water sample in the first oxidation tank 71 is taken synchronously, that is, the water inlet opening time point of the second oxidation tank 72 is set as the time point for taking the water sample.

[0088] The water in the first oxidation tank 71 is taken as a sample to determine the pollutant concentration, and ozone is added to the second oxidation tank 72 for oxidation and degradation based on the detection result of the pollutant concentration; the time interval between the ozone adding time point and the water discharge opening time point of the second oxidation tank 72 is set as the treatment waiting time; the time point at which the water in the second oxidation tank 72 is oxidized and degraded is set as the water discharge time point of the second oxidation tank 72. The water discharge time of the second oxidation tank 72 is equal to the water inlet time of the second oxidation tank 72. After the water in the second oxidation tank 72 is discharged, the second oxidation tank 72 is opened for water inlet to start a cycle of operation.

[0089] Because the first oxidation tank 71 is constantly filled with water, there is a time lag between the filling of the second oxidation tank 72 (which is waiting for oxidation treatment) and the drainage mode, causing water to gradually accumulate in the first oxidation tank 71. To prevent the ozone oxidation tank 7 from overflowing, the system is set to stop filling the first oxidation tank 71 when the water volume reaches half of the total volume of the ozone oxidation tank 7. After the remaining water in the oxidation tank is purified, the first oxidation tank 71 is then filled with water normally again. The second oxidation tank 72 is then opened or closed according to a set time point to start a new purification cycle.

[0090] Based on this, and based on the integrated influent mode, treatment mode and drainage mode system and method provided above, the following describes in detail the scheme for batch and multiple addition of sewage through periodic cyclic iterative influent and drainage, combined with scenarios and parameters.

[0091] Example 1: A miniaturized ozone oxidation tank with periodic cyclical water intake, treatment, and drainage.

[0092] In advanced oxidation treatment processes for wastewater, for small-scale, rapid-treatment ozone oxidation tanks, the process typically involves a 2-hour influent cycle. The wastewater volume is calculated based on the flow rate, and the concentrations of COD and BOD in the wastewater are measured. Based on the measurement results, ozone is added in a single step for oxidation and degradation.

[0093] Following the conventional method of one-time quantitative dosing, the waiting time for BOD / COD test results is usually 0.5 hours. At room temperature, the ozone degradation time is set to 0.5 hours. Calculating the time required for one treatment cycle after quantitative dosing of ozone after one influent, it is 5 hours (2×2+0.5×2=5). The ratio of one cycle time to water treatment volume is 5:2, and the coefficient is 2.5. It can be seen that the smaller the coefficient, the higher the wastewater treatment efficiency.

[0094] For ease of calculation and understanding, based on fundamental information about wastewater oxidation and degradation treatment equipment and processes in the field, in this embodiment: the influent (mode) operating time is set to... The treatment time (mode) for ozone oxidation degradation is... The drainage (mode) operation time is .

[0095] The water intake (mode) running time is The running time for drainage (mode) is equal( Furthermore, for ease of calculation, the influent volume in the following embodiments is measured in terms of influent time.

[0096] In this embodiment of the application, within a purification cycle, at the beginning of each cycle when the second valve is opened to execute the water intake mode, water in the first oxidation tank 71 is simultaneously collected as a carrier to obtain water sample for testing.

[0097] Within one purification cycle, the time taken for each adjacent water intake mode is equal; that is, the water intake time for each cycle is... Processing time is Drainage time is The water in the second oxidation tank 72 is discharged, combined with the attached... Figure 5 The table shows the parameters, indicating that the Nth cycle of operation has ended, and the water volume in the first oxidation tank 71 is N ( The water intake volume and the time required to complete the process are as follows: , Unit: hour.

[0098] If it is predicted that after completing the (N+1)th cycle of the operating mode, the water volume in the first oxidation tank 71 exceeds half of the oxidation tank volume, then when the Nth cycle of the operating mode is completed, the first valve 1 and the third valve 3 will be closed, the first oxidation tank 71 will stop receiving water, and the second valve 2 will be opened to connect the first oxidation tank 71 and the second oxidation tank 72. The current pollutant concentration in the ozone oxidation tank 7 will be detected, and the water volume in the first oxidation tank 71 and the second oxidation tank 72 will be balanced. Since all the remaining water volume is oxidized at once, the water volume balancing time in the two separate tanks is relatively long, not less than the waiting time for pollutant concentration detection. Therefore, while waiting for the pollutant concentration detection results, oxidation degradation, and water volume balancing in the two separate tanks, these processes are carried out simultaneously. At the end of the oxidation treatment, regardless of whether the water in the first oxidation tank 71 and the second oxidation tank 72 is balanced, all the water can be discharged.

[0099] Based on the above, for example, the influent (mode) operation time of a small-scale rapid wastewater treatment process. Set to 0.25 hours, drainage (mode) running time is... This corresponds to 0.25 hours. During the cycle, the ozone oxidation time is set to 0.25 hours each time.

[0100] It is estimated that when the second round of operation mode ends, the water volume in the first oxidation tank 71 will be the inflow volume of 1 hour, which is exactly half of the inflow volume of 2 hours. The time required for one round is 0.75 hours, and the total water volume treated in one water purification cycle is the inflow volume of 1.5 hours (0.25×2+1=1.5), and the total time is 3 hours (0.75×2+1+0.25×2=3).

[0101] The ratio of one cycle time to water treatment volume is 3:1.5, and the coefficient is 2.0. The scheme described in Example 1 has a better wastewater treatment efficiency than the existing conventional one-time influent and one-time dosing method.

[0102] Combined with appendix Figure 6 The wastewater treatment cycle time and corresponding treatment volume provided in the example show that this embodiment can treat the influent volume corresponding to 12 hours in 24 hours, while the conventional method of one-time influent and one-time addition would require 30 hours to treat the influent volume corresponding to 12 hours. This embodiment can treat the influent volume corresponding to 24 hours in 48 hours, while the conventional method of one-time influent and one-time addition would require 60 hours to treat the influent volume corresponding to 24 hours. Therefore, for long-term continuous cycle treatment, the high-frequency, low-volume, batch-based cycle treatment method of this embodiment is more efficient than the conventional method.

[0103] Example 2: Large oxidation tank, divided into iterative tanks, with the inlet and outlet times of adjacent cycles increasing iteratively, and the inlet, treatment and outlet cycles being cyclically circulated.

[0104] In advanced oxidation treatment processes for wastewater, large wastewater treatment tanks typically receive water for more than ten hours at a time. Taking 10 hours as an example, the wastewater volume is calculated based on the flow rate, and the concentrations of COD and BOD in the wastewater are detected. Based on the detection results, ozone is added in one go for oxidation and degradation.

[0105] For ease of calculation, the water inlet volume in the following embodiments is measured in terms of water inlet time.

[0106] Following the conventional method of one-time quantitative dosing, the waiting time for BOD / COD test results is typically 0.5 hours. At room temperature, the ozone degradation time is set to 0.5 hours. With one-time calculation and dosing of ozone, the total water volume treated in one treatment cycle is the influent volume of 10 hours, and the total time is 21.5 hours (10×2+1.5=21.5). The ratio of one cycle time to water treatment volume is 21.5:10, and the coefficient is 2.15.

[0107] For ease of calculation and understanding, based on fundamental information about wastewater oxidation and degradation treatment equipment and processes in the field, in this embodiment: the influent (mode) operating time is set to... The treatment time (mode) for ozone oxidation degradation is... The drainage (mode) operation time is .

[0108] The water intake (mode) running time is The running time for drainage (mode) is equal( Furthermore, for ease of calculation, the influent volume in the following embodiments is measured in terms of influent time.

[0109] Combined with appendix Figure 7The table contains periodic parameters. In one purification cycle of this application embodiment, during the first round of system operation mode cycling, the water inlet time is... Processing time is Drainage time is The water in the second oxidation tank 72 is discharged, and the first round of operation cycle ends. The water volume in the first oxidation tank 71 is ( The water intake volume and the time required to complete the process are as follows: .

[0110] The time taken to complete one water intake mode is defined as one unit water intake time. In a purification cycle, the time taken for the subsequent water intake mode is greater than the time taken for the adjacent preceding water intake mode, and the water intake volume in the next iteration increases by the water intake volume corresponding to one treatment time. The time taken for the drainage mode is equal to the time taken for the water intake mode.

[0111] Initiate the second cycle of operation. The water intake time for the second cycle of operation is... Processing time is Drainage time is The water in the second oxidation tank 72 is discharged, and the second cycle of operation ends. The water volume in the first oxidation tank 71 is (2 The water intake volume and the time required to complete the process are as follows: .

[0112] The Nth cycle of operation is initiated, and the water intake time for the Nth cycle is... Processing time is Drainage time is The water in the second oxidation tank 72 is discharged, and the second cycle of operation ends. The water volume in the first oxidation tank 71 is... Water intake volume, time required to complete .

[0113] If it is predicted that after completing the (M+1)th cycle of the operating mode, the water volume in the first oxidation tank 71 will exceed half of the oxidation tank volume, then when the Mth cycle of the operating mode is completed, the first valve and the third valve will be closed, the first oxidation tank 71 will stop receiving water, and the second valve will be opened to connect the first oxidation tank 71 with the second oxidation tank 72. The current pollutant concentration in the ozone oxidation tank will be detected, and the water volume in the first oxidation tank 71 and the second oxidation tank 72 will be balanced. Since all the remaining water volume is oxidized at once, the water volume balancing time in the two separate tanks is relatively long, not less than the waiting time for pollutant concentration detection. Therefore, the waiting for the pollutant concentration detection results, oxidation degradation, and water volume balancing in the two separate tanks will be carried out simultaneously. At the end of the oxidation treatment, regardless of whether the water in the first oxidation tank 71 and the second oxidation tank 72 is balanced, all the water can be discharged. Therefore, the drainage operation takes the longest time in the final cleaning process.

[0114] Based on the above, for example, in large-scale wastewater treatment processes, the influent (mode) operating time... Set to 0.5 hours, drainage (mode) running time This corresponds to 0.5 hours, with each ozone oxidation cycle set to 0.5 hours. Therefore, it is estimated that at the end of the fourth cycle, the water volume in the first oxidation tank 71 will be 7 hours' worth of influent, exceeding half of the full capacity for 10 hours' worth of influent. At the end of the third cycle, the water volume in the first oxidation tank 71 will be 4.5 hours' worth of influent, having already been oxidized and discharged after 3 hours of influent. Therefore, after one complete water treatment cycle, the total treated water volume is 7.5 hours' worth of influent, and the total time is 13 hours (7.5 + 4.5 + 0.5 × 2 = 13).

[0115] See appendix Figure 8 The provided wastewater treatment cycle time and corresponding treated water volume show that, in Example 2, the ratio of time to treated water volume for one complete cycle is 13:7.5, with a coefficient of 2.0; the coefficient for the ratio of time to treated water volume for two or more complete cycles is 1.73. The smaller the coefficient, the higher the wastewater treatment efficiency.

[0116] This embodiment, using a batch-based ozone dosing method, takes 26 hours for two complete cycles, treating 15 hours' worth of water, nearly halving the time and treating three-quarters of the water volume. In the long term, taking a week as an example, a single ozone dosing cycle to complete seven cycles would take 150.5 hours, treating 70 hours' worth of water. Eight cycles would require 172 hours, treating 80 hours' worth of water. In contrast, this batch-based ozone dosing method takes 169 hours, treating 97.5 hours' worth of water. The comparison shows that the longer the long-term cycle time, the more significant the advantage of this embodiment, making it more efficient than a single-cycle ozone dosing method.

[0117] Each complete cycle takes less time, and several batches are cyclically processed within each complete cycle. In the event of a failure, there are more "emptied" and treatable nodes, which is more conducive to maintaining the sewage treatment system.

[0118] The intelligent dosing control system and method provided by this invention adjusts the ozone dosage based on BOD / COD concentration data and wastewater volume data.

[0119] The BOD / COD concentration ratio was set at 0.3; based on this, the ozone dosage was adjusted.

[0120] For downstream biological treatment processes, the ozone stage only needs to improve the biodegradability of organic matter in wastewater. After the biodegradability is improved, the wastewater enters the subsequent biological system, which is conducive to the better degradation of organic matter in the water by microorganisms.

[0121] When the BOD / COD concentration is greater than 0.3, reduce the ozone dosage, ensuring it does not exceed the theoretical dosage required to reduce the pollutant concentration to the preset value. When the BOD / COD concentration is less than 0.3, increase the ozone dosage, ensuring it does not fall below the theoretical dosage required to reduce the pollutant concentration to the preset value. This online adjustment of the ozone dosage improves the biodegradability of the wastewater.

[0122] For back-end effluent discharge, it is only necessary to monitor COD levels and adjust the ozone dosage via a control device to ensure that the effluent meets discharge standards. The ozone dosage can be controlled at a coefficient of 0.9-1.1, and the changes in effluent COD are fed back to the monitoring system to control the ozone dosage of the ozone generator.

[0123] The ozone dosage is set to satisfy the constraint formula: .

[0124] in, The value is expressed as ozone dosage, kg / h; a is a variable coefficient, 0.9-1.1; b is the flow rate of the wastewater to be treated, m. 3 / h; X represents the concentration of the pollutant to be degraded, in mg / L.

[0125] Based on pollutant concentration and wastewater volume, the ozone dosage is accurately calculated and precisely added to avoid over- or under-dosing.

[0126] In summary, this invention improves wastewater treatment efficiency by shortening the unit influent / outfluent time and using high-frequency, low-flow batch cyclic treatment. Furthermore, during each cycle and subsequent cycles within a cycle, the ozone dosage is customized based on the wastewater influent volume to avoid insufficient or excessive dosage.

[0127] The above embodiments are merely illustrative of the technical concept and features of the present invention, intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and should not be construed as limiting the scope of protection of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of the present invention is defined by the appended claims rather than the foregoing description, and thus all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention.

Claims

1. An intelligent ozone dosing control system for wastewater treatment, characterized in that, include: The ozone oxidation pond includes a first oxidation pond and a second oxidation pond; The first valve is installed at the inlet of the ozone oxidation tank and is used to control the flow of water into the first oxidation tank. The second valve, installed between the first oxidation tank and the second oxidation tank, is used to control the flow of water into the second oxidation tank. The third valve is installed at the outlet of the second oxidation tank and is used to discharge the water after oxidation and degradation. Ozone generator; Used to add ozone to the ozone oxidation tank; Online monitoring devices are used to monitor the concentration of pollutants in wastewater online. The control device is electrically connected to the online monitoring device and the ozone generator, respectively; Based on the current water pollutant concentration status obtained by the online monitoring device, a command is sent to the ozone generator to control the ozone dosage in the ozone oxidation pond; wherein, the pollutant concentration status is the obtained BOD and COD concentration data; Based on the current wastewater volume in the first oxidation tank and the second oxidation tank, the opening or closing of the first valve and the second valve is controlled; and the water inlet mode, water outlet mode and treatment mode are set according to the on / off state of the first valve, the second valve and the third valve, so as to integrate water inlet, water outlet and pollutant oxidation and degradation. The first valve is normally open, maintaining water intake. When the second valve is open and the third valve is closed, it is set to the water inlet mode, and water is introduced into the second oxidation tank; when both the second and third valves are closed, it is set to the treatment mode, and the pollutants in the second oxidation tank are oxidized and degraded; when the second valve is closed and the third valve is open, it is the drainage mode, and the oxidation of the water in the second oxidation tank is completed, and the purified water is discharged; within one cycle, the water inlet mode, treatment mode and drainage mode are repeated. During the cycle, the time taken to complete one water intake mode is one unit water intake time, and the time taken for the drainage mode is set to be equal to the time taken for the water intake mode. If, during the next cycle of water intake, treatment, and drainage, the water volume in the first oxidation tank exceeds half the volume of the ozone oxidation tank, the first valve will be closed. After the remaining water in the ozone oxidation tank is purified, the first valve will be opened again to start a new purification cycle. In each cycle of water intake, treatment, and drainage modes, water samples are collected from the first oxidation tank as a carrier to obtain water test samples. Based on the pollutant concentration determined by the online monitoring device based on the test samples, ozone is added to the second oxidation tank.

2. The intelligent ozone dosing control system for wastewater treatment according to claim 1, characterized in that, Within a cycle, the time taken for the water intake mode in adjacent rounds is equal, and the time taken for the drainage mode in adjacent rounds is also equal. In each cycle, at the beginning of the second valve opening to execute the water intake mode, water samples are simultaneously collected from the first oxidation tank as a carrier to obtain water sample test samples. When the water intake mode is completed, the water volume in the second oxidation tank is equal to the water intake volume per unit time; close the second valve, and add ozone to the second oxidation tank according to the pollutant concentration measured by the online monitoring device based on the test sample; After a period of time, wait for the degradation to complete, and then discharge the treated water from the second oxidation tank.

3. The intelligent ozone dosing control system for wastewater treatment according to claim 1, characterized in that, If the time taken in the subsequent water intake mode is greater than the time taken in the adjacent preceding water intake mode, and the water intake volume in the subsequent water intake mode is iterated by adding the water intake volume corresponding to the processing time, the iterative update is performed, and the time taken in the corresponding drainage mode is updated synchronously. When the water intake mode is completed, the water volume in the second oxidation tank is equal to the water intake volume per unit time according to the set flow rate; the second valve is closed, and water samples are obtained using the water in the first oxidation tank as a carrier. Based on the pollutant concentration determined by the online monitoring device based on the sample, ozone is added to the second oxidation tank. After a period of time, wait for the degradation to complete, and then discharge the treated water from the second oxidation tank.

4. A method for intelligent ozone dosing control in wastewater treatment, used to implement the intelligent ozone dosing control system for wastewater treatment as described in any one of claims 1-3, characterized in that, include: Control the normal influent flow into the first oxidation tank of the ozone oxidation pond; Set the time points for obtaining water samples, as well as the time points for water inflow and drainage into the second oxidation tank; The water in the first oxidation pond was used as a sample to determine the pollutant concentration. Based on the pollutant concentration detection results, ozone was added to the second oxidation pond for oxidation and degradation. When the water volume in the first oxidation tank of the ozone oxidation pond reaches half of the total volume, the first oxidation tank stops receiving water. After the remaining water in the oxidation tank is purified, the first oxidation tank is then allowed to receive water again at normal levels to begin a new purification cycle.

5. The intelligent ozone dosing control method for wastewater treatment according to claim 4, characterized in that, During one purification cycle, the first oxidation tank is normally filled with water. The time interval between the start and stop times of the second oxidation tank water intake is the water intake time. When the second oxidation tank starts to receive water, water samples from the first oxidation tank are simultaneously acquired. The ozone dosage is calculated based on the given pollutant concentration detection results. The time interval between the ozone dosage time and the opening time of the second oxidation tank is the waiting treatment time. The drainage time of the second oxidation tank is equal to the water inlet time of the second oxidation tank.

6. The intelligent ozone dosing control method for wastewater treatment according to claim 5, characterized in that, In one purification cycle, multiple rounds of influent, oxidation, and effluent treatment are performed in the second oxidation tank. The operating mode of each round is represented as follows: The water intake time for the Nth cycle of the operating mode is Drainage time is Processing time is Water is discharged from the second oxidation tank, leaving a residual water volume in the first oxidation tank equal to... The water intake volume within a given time period, from the start of the current purification cycle to the end of the Nth cycle, is... Where N is a positive integer; If it is predicted that after completing the N+1th cycle of the operation mode, the water volume in the first oxidation tank exceeds half the volume of the ozone oxidation tank, then when the Nth cycle of the operation mode is completed, the first oxidation tank will stop receiving water, and the first oxidation tank will be connected to the second oxidation tank. The concentration of pollutants in the current ozone oxidation tank will be detected, ozone will be added according to the concentration of pollutants, and all water will be discharged after the oxidation and degradation treatment is completed.

7. The intelligent ozone dosing control method for wastewater treatment according to claim 5, characterized in that, In one purification cycle, multiple rounds of influent, oxidation, and effluent treatment are performed in the second oxidation tank. The operating mode of each round is represented as follows: The water intake time for the Mth cycle of operation is Processing time is Drainage time is The water in the second oxidation tank is discharged, and the second cycle of operation ends. The remaining water volume in the first oxidation tank is... The corresponding water intake volume within a given time period, and the time required to complete the process are as follows: Where M is a positive integer; If it is predicted that after completing the M+1th cycle of the operation mode, the water volume in the first oxidation tank exceeds half the volume of the ozone oxidation tank, then when the Mth cycle of the operation mode is completed, the first oxidation tank will stop receiving water, and the first oxidation tank will be connected to the second oxidation tank. The concentration of pollutants in the current ozone oxidation tank will be detected, and all water will be discharged after ozone is added and the oxidation and degradation treatment is completed.

8. The intelligent ozone dosing control method for wastewater treatment according to claim 4, characterized in that, If the oxidation tank discharges wastewater directly to the outside, the ozone dosage should be controlled based on the COD concentration; the ozone dosage should satisfy the constraint formula: ; in, The value represents the ozone dosage; a is a variable coefficient, 0.9-1.1; b represents the flow rate of the wastewater to be treated; and X represents the concentration of COD to be degraded.

9. The intelligent ozone dosing control method for wastewater treatment according to claim 4, characterized in that, If the downstream of the oxidation tank is a biological treatment process, the ozone dosage should be adjusted according to the changes in BOD5 / COD obtained from the detection. The BOD5 / COD concentration comparison value was set at 0.3; If the BOD5 / COD concentration is greater than 0.3, reduce the ozone dosage, and the ozone dosage should not exceed the theoretical addition amount that would reduce the pollutant concentration to the preset value. When the BOD5 / COD concentration is less than 0.3, increase the ozone dosage, ensuring that the ozone dosage is not less than the theoretical amount required to reduce the pollutant concentration to the preset value.

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