High-salt organic wastewater resourceful treatment device and method

Abstract

The application belongs to the technical field of wastewater treatment, and particularly relates to a high-salt organic wastewater resource treatment device and method, which comprises sequentially connected pretreatment units, advanced oxidation units, membrane concentration units, evaporation crystallization and salt separation units and auxiliary control units. The advanced oxidation units and the membrane concentration units are directly connected. The auxiliary control units are electrically connected with the pretreatment units, the advanced oxidation units, the membrane concentration units and the evaporation crystallization and salt separation units. The connected pretreatment units, advanced oxidation units, membrane concentration units, evaporation crystallization and salt separation units and auxiliary control units are integrated on an integrated rack. The pretreatment units, advanced oxidation units, membrane concentration units, evaporation crystallization and salt separation units and auxiliary control units are all integrated on the same integrated rack to form a full-process integrated pry-mounted structure, which can greatly reduce the equipment floor area (by 60%-70%), facilitate transportation and on-site rapid installation, and is particularly suitable for enterprises with land shortage and emergency treatment scenes.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a device and method for the resource-based treatment of high-salt organic wastewater. Background Technology

[0002] With rapid industrial development, industries such as chemical, pharmaceutical, printing and dyeing, and landfill leachate treatment have generated large amounts of high-salt organic wastewater. This type of wastewater is characterized by high salt content, high organic matter concentration, complex composition, and poor biodegradability. If discharged directly without proper treatment, it will cause serious harm to the ecological environment.

[0003] Currently, the main technologies for treating high-salinity organic wastewater include advanced oxidation technology, membrane separation technology, and evaporation crystallization technology. Various treatment devices and methods already exist in the prior art. For example, patent document CN221166087U discloses an integrated evaporation, concentration, and drying device for the pretreatment of high-salinity, high-pollutant wastewater, employing an integrated skid-mounted design; patent document CN107746146B discloses a skid-mounted device for treating high-salinity wastewater and its evaporation and concentration structure; and patent document CN221275548U discloses a skid-mounted device for treating high-concentration brine from landfill leachate. However, existing treatment devices and methods have the following technical problems: The process flow is lengthy and the equipment occupies a large area: Traditional processing technology usually disperses each processing unit and sets up multiple intermediate regulating tanks, buffer tanks and other facilities between units, resulting in a large area occupied by the entire processing system and complex pipeline connections, which is not suitable for industrial enterprises with limited space. Low coupling between units and poor system stability: In existing technologies, an intermediate equalization tank is usually set between the advanced oxidation unit and the membrane concentration unit to buffer the impact of water quality fluctuations on the membrane system. However, this design increases the process steps, prolongs the treatment process, and cannot achieve synergistic linkage between units, resulting in a slow system response speed. Low level of resource utilization: Many existing technologies only focus on achieving the standard discharge of wastewater, failing to achieve effective separation and resource utilization of salt, resulting in resource waste; Insufficient level of intelligence: Existing devices mostly use manual or semi-automatic control methods, which makes it difficult to dynamically adjust operating parameters according to changes in influent water quality, affecting treatment effect and operational stability.

[0004] Therefore, based on the above-mentioned technical problems, a device and method for the resource-based treatment of high-salt organic wastewater were designed. Summary of the Invention

[0005] To overcome the problems of existing technologies, this invention proposes a device and method for the resource-based treatment of high-salt organic wastewater.

[0006] The technical solution adopted by the present invention to solve its technical problem is: a high-salt organic wastewater resource treatment device, comprising a pretreatment unit, an advanced oxidation unit, a membrane concentration unit, an evaporation crystallization salt separation unit and an auxiliary control unit connected in sequence. The advanced oxidation unit and the membrane concentration unit are directly connected. The auxiliary control unit is electrically connected to the pretreatment unit, the advanced oxidation unit, the membrane concentration unit and the evaporation crystallization salt separation unit. The connected pretreatment unit, advanced oxidation unit, membrane concentration unit, evaporation crystallization salt separation unit and auxiliary control unit are integrated on an integrated frame.

[0007] Working Principle: This device adopts a complete process chain of "pretreatment → advanced oxidation → membrane concentration → evaporation crystallization and desalination". Through integrated design and intelligent collaborative control, it realizes continuous treatment and resource recovery of high-salt organic wastewater. This device eliminates the intermediate equalization tank between the advanced oxidation unit and the membrane concentration unit. This is achieved through the following four levels of collaborative mechanisms: Since all units are integrated into a single frame, the physical distance is shortened to the meter level, and the advanced oxidation effluent can enter the membrane concentration unit within seconds, reducing water quality changes during transmission; The advanced oxidation unit strengthens process control, ensuring stable and controllable effluent quality. Online monitoring instruments provide real-time feedback on the oxidation process, ensuring controllable oxidation endpoints and minimal effluent quality fluctuations; The auxiliary control unit dynamically regulates, trading "speed" for "stability", monitoring the advanced oxidation effluent quality in real time and dynamically adjusting the operating parameters of the membrane concentration unit. The second-level response after fluctuations replaces the time-level buffering of the buffer tank; The closed-loop continuous treatment structure deeply couples each unit, creating a closed-loop information system. Membrane system anomalies can reversely adjust the advanced oxidation, shifting from "independent operation" to "collaborative linkage".

[0008] Preferably, the pretreatment unit includes an equalization tank, a coagulation sedimentation tank, and a filtration device connected in sequence; the advanced oxidation unit includes any one or more of a Fenton oxidation device, an electrocatalytic oxidation device, an ozone catalytic oxidation device, and a photocatalytic oxidation device; the membrane concentration unit includes at least one stage of reverse osmosis membrane module or nanofiltration membrane module; the equalization tank is used to balance water quality and quantity fluctuations and prevent shocks; the coagulation sedimentation tank is used to remove suspended solids and colloids and reduce turbidity; the filtration device further reduces suspended solids and ensures stable operation of subsequent units; the effluent from the pretreatment unit has suspended solids ≤10mg / L and turbidity ≤3NTU, providing stable feed water for the advanced oxidation unit.

[0009] Preferably, the advanced oxidation unit is equipped with online monitoring instruments for real-time monitoring of the oxidation-reduction potential, pH value, and organic matter concentration of the effluent, and transmits the monitoring data to the auxiliary control unit. The auxiliary control unit dynamically adjusts the operating pressure and recovery rate of the membrane concentration unit based on the effluent quality of the advanced oxidation unit, monitors key water quality parameters of the effluent in real time, and transmits the data to the auxiliary control unit. The auxiliary control unit dynamically adjusts oxidation conditions (current density, reagent dosage, residence time, etc.) based on the monitoring data to ensure stable and controllable effluent quality.

[0010] Preferably, the evaporation crystallization salt separation unit includes an evaporator and a salt separation crystallizer. The evaporator is a mechanical vapor recompression evaporator or a multi-effect evaporator. The salt separation crystallizer includes a high-temperature crystallizer and a low-temperature crystallizer connected in sequence, used to separately precipitate sodium sulfate and sodium chloride. It receives the high-concentration brine from the membrane concentration unit, and the water is vaporized and separated by heating and evaporation. After the salt reaches supersaturation, crystals precipitate. Utilizing the difference in solubility of sodium chloride and sodium sulfate at different temperatures, salt separation and recovery are achieved through two-stage crystallization.

[0011] Preferably, the auxiliary control unit includes a programmable logic controller or a distributed control system; the auxiliary control unit is electrically connected to online water quality monitoring instruments, flow meters, pressure sensors, level sensors and electric valves, and automatically adjusts the actuators by collecting the process parameters of each unit in real time and using preset control algorithms to achieve coordinated operation and dynamic optimization of the entire system.

[0012] A method for resource recovery treatment of high-salt organic wastewater includes the following steps: Pretreatment: Wastewater enters the pretreatment unit to remove suspended solids and colloids; Advanced oxidation: Pretreated effluent enters the advanced oxidation unit to oxidize and decompose organic matter; Membrane concentration: The effluent from the advanced oxidation process is directly fed into the membrane concentration unit for concentration and volume reduction. The permeate is reused, and the concentrate is used in the next step. Evaporation, crystallization, and salt separation: The concentrated water from the membrane concentration enters the evaporation, crystallization, and salt separation unit for evaporation, concentration, and step-by-step crystallization to recover industrial salt.

[0013] Preferably, in the membrane concentration step, the auxiliary control unit dynamically adjusts the operating pressure and recovery rate of the membrane concentration unit based on real-time monitoring data of the effluent quality from the advanced oxidation unit.

[0014] Preferably, in the evaporation crystallization and salt separation step, sodium sulfate is first evaporated and crystallized at 70-90°C, and then the mother liquor is cooled to 10-25°C to precipitate sodium chloride.

[0015] Preferably, in the advanced oxidation step, the oxidation-reduction potential, pH value and organic matter concentration of the oxidized effluent are monitored in real time by an online monitoring instrument, and the monitoring data is transmitted to the auxiliary control unit. The auxiliary control unit adjusts the operating parameters of the advanced oxidation unit according to the monitoring data to ensure stable effluent quality.

[0016] The advantages of this invention are: 1. This invention integrates the pretreatment unit, advanced oxidation unit, membrane concentration unit, evaporation crystallization and salt separation unit, and auxiliary control unit onto the same integrated frame, forming a fully integrated skid-mounted structure. This can significantly reduce the equipment footprint (by 60%-70%), facilitate transportation and rapid on-site installation, and is particularly suitable for enterprises with limited land and emergency response scenarios.

[0017] 2. This invention achieves synergistic operation of oxidation and membrane separation by directly connecting the advanced oxidation unit and the membrane concentration unit, eliminating the need for an intermediate equalization tank. This design shortens the process flow, reduces the residence time of materials between units, realizes true continuous flow processing, and improves overall processing efficiency (processing time reduced by 30%-50%).

[0018] 3. This invention uses an auxiliary control unit to monitor the effluent quality of the advanced oxidation unit in real time and dynamically adjust the operating parameters of the membrane concentration unit. This dynamic control approach mitigates the risks associated with eliminating the intermediate equalization tank, thereby enhancing the system's ability to cope with water quality fluctuations and achieving deep coupling between oxidation and membrane separation. Experiments show that with influent water quality fluctuations of ±20%, the rate of increase in transmembrane pressure difference in the membrane system is reduced by 50%, and the membrane cleaning cycle is doubled. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the control flow logic of the present invention; Figure 3 This is a flowchart illustrating the wastewater resource recovery process of this invention.

[0021] In the diagram: 1. Integrated frame; 2. Pretreatment unit; 3. Equalization tank; 4. Coagulation sedimentation tank; 5. Filtration device; 6. Advanced oxidation unit; 7. Membrane concentration unit; 8. Evaporation crystallization salt separation unit; 9. High-temperature crystallizer; 10. Low-temperature crystallizer; 11. Auxiliary control unit. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1

[0024] Please see Figures 1-3 As shown, a high-salt organic wastewater resource utilization treatment device includes a pretreatment unit 2, an advanced oxidation unit 6, a membrane concentration unit 7, an evaporation crystallization salt separation unit 8, and an auxiliary control unit 11 connected in sequence. The advanced oxidation unit 6 and the membrane concentration unit 7 are directly connected. The auxiliary control unit 11 is electrically connected to the pretreatment unit 2, the advanced oxidation unit 6, the membrane concentration unit 7, and the evaporation crystallization salt separation unit 8. The connected pretreatment unit 2, the advanced oxidation unit 6, the membrane concentration unit 7, the evaporation crystallization salt separation unit 8, and the auxiliary control unit 11 are integrated on an integrated frame 1.

[0025] The pretreatment unit 2 includes an equalization tank 3, a coagulation sedimentation tank 4, and a filtration device 5 connected in sequence; the advanced oxidation unit 6 includes any one or more of the following: a Fenton oxidation device, an electrocatalytic oxidation device, an ozone catalytic oxidation device, and a photocatalytic oxidation device; the membrane concentration unit 7 includes at least one stage of reverse osmosis membrane module or nanofiltration membrane module. The equalization tank 3 is used to balance water quality and quantity fluctuations and prevent shocks. The coagulation sedimentation tank 4 is used to remove suspended solids and colloids and reduce turbidity. The filtration device 5 further reduces suspended solids and ensures stable operation of subsequent units. The effluent from the pretreatment unit 2 has suspended solids ≤10mg / L and turbidity ≤3NTU, providing stable feed water for the advanced oxidation unit 6.

[0026] The advanced oxidation unit 6 is equipped with online monitoring instruments for real-time monitoring of the oxidation-reduction potential, pH value, and organic matter concentration of the effluent, and transmits the monitoring data to the auxiliary control unit 11. The auxiliary control unit 11 dynamically adjusts the operating pressure and recovery rate of the membrane concentration unit 7 based on the effluent quality of the advanced oxidation unit 6, monitors key water quality parameters of the effluent in real time, and transmits the data to the auxiliary control unit 11. The auxiliary control unit 11 dynamically adjusts oxidation conditions (current density, reagent dosage, residence time, etc.) based on the monitoring data to ensure stable and controllable effluent quality.

[0027] The evaporation crystallization salt separation unit 8 includes an evaporator and a salt separation crystallizer. The evaporator is a mechanical vapor recompression evaporator or a multi-effect evaporator. The salt separation crystallizer includes a high-temperature crystallizer 9 and a low-temperature crystallizer 10 connected in sequence, used to separately precipitate sodium sulfate and sodium chloride. It receives the high-concentration brine from the membrane concentration unit 7, and the water is vaporized and separated by heating and evaporation. After the salt reaches supersaturation, crystals precipitate. Utilizing the difference in solubility of sodium chloride and sodium sulfate at different temperatures, salt separation and recovery are achieved through two-stage crystallization.

[0028] The auxiliary control unit 11 includes a programmable logic controller or a distributed control system; the auxiliary control unit 11 is electrically connected to online water quality monitoring instruments, flow meters, pressure sensors, level sensors and electric valves, and automatically adjusts the actuators by collecting the process parameters of each unit in real time and using preset control algorithms to achieve coordinated operation and dynamic optimization of the entire system.

[0029] Example 2

[0030] This embodiment provides a method for treating high-salt organic wastewater from a pharmaceutical company using the above-described device. The specific steps are as follows: Step 1: Pretreatment: High-salt organic wastewater (COD approximately 8000 mg / L, TDS approximately 50000 mg / L, sodium sulfate to sodium chloride mass ratio approximately 1:2) is introduced into equalization tank 3 for homogenization and equalization, with a retention time of 8 hours; then it enters coagulation sedimentation tank 4, where polyaluminum chloride (dosage 200 mg / L) and polyacrylamide (dosage 5 mg / L) are added to remove suspended solids and some organic matter; then it is filtered through a multi-media filter, and the effluent suspended solids are less than 10 mg / L and turbidity is less than 3 NTU.

[0031] Step 2, Advanced Oxidation: The pretreated effluent enters the electrocatalytic oxidation unit with a current density of 20 mA / cm² and a hydraulic retention time of 90 minutes. Online monitoring instruments monitor the effluent's ORP (controlled at 400-500 mV), pH (controlled at 7-8), and COD (reduced to below 800 mg / L) in real time. The auxiliary control unit 11 automatically adjusts the current density based on the monitoring data to ensure stable effluent quality.

[0032] Step 3, Membrane Concentration: The effluent from the advanced oxidation process directly enters the two-stage reverse osmosis membrane concentration unit 7 (without an intermediate equalization tank 3). The auxiliary control unit 11 automatically adjusts the reverse osmosis operating pressure based on the COD and pH value of the advanced oxidation effluent. The operating pressure for the first stage of reverse osmosis is 1.5 MPa, and the operating pressure for the second stage is 3.0 MPa, with a recovery rate of 75%. The product water has a COD of less than 50 mg / L and a TDS of less than 200 mg / L, and is reused in the production process; the concentrate has a TDS of over 80,000 mg / L, and its volume is reduced to 25% of the original water volume.

[0033] Step 4: Evaporation, Crystallization, and Salt Separation: The concentrated water from the membrane concentrate enters a mechanical vapor recompression evaporator, where the evaporation temperature is controlled at 80-85℃, concentrating the salt to approximately 35%. It then enters a high-temperature crystallizer 9, where the temperature is controlled at 80℃ and the residence time is 4 hours, precipitating anhydrous sodium sulfate crystals. After centrifugation and drying, sodium sulfate product is obtained. The separated mother liquor enters a low-temperature crystallizer 10, where the temperature is lowered to 15℃ and the residence time is 3 hours, precipitating sodium chloride crystals. After centrifugation and drying, sodium chloride product is obtained. The crystallization mother liquor is returned to the front end of the evaporator for recycling.

[0034] Example 3

[0035] This embodiment is basically the same as Embodiment 2, except that the object of treatment is high-salt organic wastewater from a dyeing and printing enterprise (COD approximately 5000 mg / L, TDS approximately 30000 mg / L, mainly sodium chloride). Advanced oxidation unit 6 uses ozone catalytic oxidation with an ozone dosage of 100 mg / L and a residence time of 60 minutes. Evaporation, crystallization, and salt separation unit 8 uses a quadruple-effect evaporator with a steam consumption of 0.22 tons of steam / ton of water. The final sodium chloride product obtained has a purity of 99%, and the water recovery rate is 96%.

[0036] Example 4

[0037] The comparative apparatus was basically the same as that in Example 2, except that an intermediate equalization tank 3 was set between the advanced oxidation unit 6 and the membrane concentration unit 7, without dynamic control. The operating effects of Example 2 and the comparative apparatus were tested under conditions of ±20% fluctuation in influent water quality.

[0038] Test results: The transmembrane pressure differential rise rate of this device is 0.5 kPa / d, while that of the control device is 1.0 kPa / d, representing a 50% reduction in this device. The membrane cleaning cycle of this device is 60 days, while that of the control device is 30 days, which is twice as long as that of this device. The product water quality of this device is stable, with COD consistently below 50 mg / L; in contrast, the COD of the product water of the control device occasionally exceeds the standard when the influent fluctuates. This device occupies only 35% of the area of ​​the comparison device.

[0039] Example 5

[0040] This embodiment is basically the same as embodiment 2, except that the pretreatment unit 2 also includes an ultrafiltration membrane assembly, which is set after the filtration device 5 to further remove fine particles and colloids, with an effluent SDI≤3, ensuring the long-term stable operation of the reverse osmosis membrane system.

[0041] Comparative example: To verify the technical effect of the present invention, a comparative example was set up. The comparative example used the same pretreatment unit 2, advanced oxidation unit 6, membrane concentration unit 7 and evaporation crystallization salt separation unit 8 as Example 2, but an intermediate conditioning tank 3 (residence time of 4 hours) was set between the advanced oxidation unit 6 and the membrane concentration unit 7, and the units were dispersed and not integrated with an integrated frame 1, nor was the dynamic control of the auxiliary control unit 11 set up.

[0042] Experimental results: The device of this invention occupies only 35% of the area of ​​the comparative example; The processing time of this invention is reduced by 40% compared to the comparative method. When the influent water quality fluctuates by ±20%, the transmembrane pressure difference rise rate of the membrane system of the present invention is reduced by 50% compared with the comparative example, and the membrane cleaning cycle is doubled. The final salt products obtained in both examples met the industrial-grade purity standard (≥98%). As can be seen from the above tests, the present invention achieves miniaturization of the processing device, shortening of the process, and stabilization of system operation through the fully integrated design of the integrated frame 1, the direct coupling of advanced oxidation and membrane concentration, and the dynamic control of the auxiliary control unit 11. Under the premise of ensuring the processing effect and resource utilization level, it significantly reduces the footprint and operation.

[0043] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A device for the resource-based treatment of high-salt organic wastewater, characterized in that: The unit includes a pretreatment unit (2), an advanced oxidation unit (6), a membrane concentration unit (7), an evaporation crystallization salt separation unit (8), and an auxiliary control unit (11) connected in sequence. The advanced oxidation unit (6) and the membrane concentration unit (7) are directly connected. The auxiliary control unit (11) is electrically connected to the pretreatment unit (2), the advanced oxidation unit (6), the membrane concentration unit (7), and the evaporation crystallization salt separation unit (8). The connected pretreatment unit (2), the advanced oxidation unit (6), the membrane concentration unit (7), the evaporation crystallization salt separation unit (8), and the auxiliary control unit (11) are integrated on an integrated frame (1).

2. The high-salt organic wastewater resource utilization treatment device according to claim 1, characterized in that: The pretreatment unit (2) includes an equalization tank (3), a coagulation sedimentation tank (4), and a filtration device (5) connected in sequence; the advanced oxidation unit (6) includes any one or more of the following: Fenton oxidation device, electrocatalytic oxidation device, ozone catalytic oxidation device, and photocatalytic oxidation device; the membrane concentration unit (7) includes at least one stage of reverse osmosis membrane module or nanofiltration membrane module.

3. The high-salt organic wastewater resource utilization treatment device according to claim 1, characterized in that: The advanced oxidation unit (6) is equipped with an online monitoring instrument for real-time monitoring of the oxidation-reduction potential, pH value and organic matter concentration of the oxidized effluent, and transmits the monitoring data to the auxiliary control unit (11); the auxiliary control unit (11) dynamically adjusts the operating pressure and recovery rate of the membrane concentration unit (7) according to the effluent quality of the advanced oxidation unit (6).

4. The high-salt organic wastewater resource utilization treatment device according to claim 1, characterized in that: The evaporation crystallization salt separation unit (8) includes an evaporator and a salt separation crystallizer. The evaporator is a mechanical vapor recompression evaporator or a multi-effect evaporator. The salt separation crystallizer includes a high-temperature crystallizer (9) and a low-temperature crystallizer (10) connected in sequence, which are used to precipitate sodium sulfate and sodium chloride respectively.

5. The high-salt organic wastewater resource utilization treatment device according to claim 1, characterized in that: The auxiliary control unit (11) includes a programmable logic controller or a distributed control system; the auxiliary control unit (11) is electrically connected to an online water quality monitoring instrument, a flow meter, a pressure sensor, a level sensor and an electric valve.

6. A method for resource-based treatment of high-salt organic wastewater as described in claims 1-5, characterized in that: Includes the following steps: Pretreatment: Wastewater enters the pretreatment unit (2) to remove suspended solids and colloids; Advanced oxidation: The pretreated effluent enters the advanced oxidation unit (6) to oxidize and decompose organic matter; Membrane concentration: The effluent from the advanced oxidation process is directly fed into the membrane concentration unit (7) for concentration and volume reduction. The permeate is reused, and the concentrate is fed into the next step. Evaporation, crystallization and salt separation: The concentrated water from the membrane concentration enters the evaporation, crystallization and salt separation unit (8) for evaporation, concentration and step crystallization to recover industrial salt.

7. The method for resource-based treatment of high-salt organic wastewater according to claim 6, characterized in that: In the membrane concentration step, the auxiliary control unit (11) dynamically adjusts the operating pressure and recovery rate of the membrane concentration unit (7) based on the real-time monitoring data of the effluent quality of the advanced oxidation unit (6).

8. The method for resource-based treatment of high-salt organic wastewater according to claim 6, characterized in that: In the evaporation crystallization and salt separation step, sodium sulfate is first evaporated and crystallized at 70-90℃, and then the mother liquor is cooled to 10-25℃ to precipitate sodium chloride.

9. The method for resource-based treatment of high-salt organic wastewater according to claim 6, characterized in that: In the advanced oxidation step, the oxidation-reduction potential, pH value and organic matter concentration of the oxidized effluent are monitored in real time by an online monitoring instrument, and the monitoring data is transmitted to the auxiliary control unit (11). The auxiliary control unit (11) adjusts the operating parameters of the advanced oxidation unit (6) according to the monitoring data to ensure stable effluent quality.

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