Integrated device and method for preparing ultrapure water based on deep degradation of TOC

Abstract

The application discloses a deep degradation TOC-based integrated ultrapure water preparation device, which comprises a pretreatment unit, a reverse osmosis desalination unit, a high-level oxidation TOC deep degradation unit, a terminal refining unit and an intelligent monitoring and control unit integrated in the same pry cabinet; the pretreatment unit removes suspended solids, colloids and large-particle impurities in the water and adjusts the pH value of the water; the reverse osmosis desalination unit is connected with the pretreatment unit and removes salt, organic matter and microorganisms in the water; the high-level oxidation TOC deep degradation unit is connected with the reverse osmosis desalination unit; and the terminal refining unit is connected with the high-level oxidation TOC deep degradation unit. Compared with the prior art, the application has the advantages that the deep degradation TOC-based integrated ultrapure water preparation device and method are provided, which realizes efficient and deep removal of TOC through the coupling of high-level oxidation, membrane separation, ion exchange and real-time monitoring technology, and realizes the high integration and intelligent operation of the device.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to an integrated device and method for preparing ultrapure water based on deep degradation of TOC. Background Technology

[0002] Ultrapure water refers to water with a resistivity of 18.2 MΩ·cm (25℃), which contains almost no impurities, bacteria, viruses, organic matter, or metal ions.

[0003] As semiconductor manufacturing processes advance towards 7nm, 5nm, and even more advanced nodes, the requirements for water quality in cell culture and drug development in the biopharmaceutical field are constantly increasing. The total organic carbon (TOC) content in ultrapure water has become a key indicator affecting product yield and the accuracy of experimental results.

[0004] Currently, the industry generally requires that the TOC content of ultrapure water be controlled below 1 μg / L, and some high-end application scenarios even require it to be below 0.1 μg / L.

[0005] Existing ultrapure water preparation processes typically employ a multi-stage combination of pretreatment, reverse osmosis, ion exchange, and ultraviolet irradiation, but these processes suffer from the following technical drawbacks: 1. Incomplete degradation of organic matter: Conventional ultraviolet oxidation processes can only decompose some small-molecule organic matter. They are not efficient enough in degrading organic pollutants such as humic substances and pharmaceutical intermediates, and cannot meet the requirements for deep TOC removal. 2. Lengthy and fragmented process chain: Each processing unit is set up independently, which occupies a large area, has low system integration, high operation and maintenance costs, and the connection between each unit is prone to secondary pollution. 3. High energy and material consumption: Ion exchange resin regeneration is frequent, ultraviolet lamps have high power and short lifespan, a large amount of wastewater is generated during operation, and resource utilization is low. 4. Poor water quality stability: It is greatly affected by fluctuations in the quality of the influent, and the TOC content of the effluent fluctuates greatly, making it impossible to achieve long-term stable ultra-high quality water supply.

[0006] To address the aforementioned industry pain points, this invention proposes an integrated ultrapure water preparation device and method that achieves deep degradation of TOC through multi-technology coupling, while improving system integration and operational stability and reducing operation and maintenance costs. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the above-mentioned technical defects and provide an integrated ultrapure water preparation device and method based on deep degradation of TOC, which achieves efficient deep removal of TOC through the coupling of advanced oxidation, membrane separation, ion exchange and real-time monitoring technologies, and at the same time realizes the highly integrated and intelligent operation of the device.

[0008] To solve the above-mentioned technical problems, the technical solution provided by the present invention is: an integrated ultrapure water preparation device based on deep degradation of TOC, including a pretreatment unit, a reverse osmosis desalination unit, an advanced oxidation TOC deep degradation unit, a terminal purification unit and an intelligent monitoring and control unit integrated in the same skid-mounted cabinet; The pretreatment unit removes suspended solids, colloids, and large particulate impurities from the influent and adjusts the pH value of the influent. The reverse osmosis desalination unit is connected to the pretreatment unit to remove salt, organic matter, and microorganisms from the water; The advanced oxidation TOC deep degradation unit is connected to the reverse osmosis desalination unit, which oxidizes and decomposes organic matter in water into CO2 and H2O. The terminal refining unit is connected to the advanced oxidation TOC deep degradation unit to remove residual ions, dissolved gases and particulate impurities from the water; The intelligent monitoring and control unit monitors the water quality parameters of each node in real time and automatically adjusts the operating parameters.

[0009] Preferably, the advanced oxidation TOC deep degradation unit includes an ozone generation component, a 185nm / 254nm dual-band ultraviolet reactor, and an advanced oxidation reaction chamber; The ozone generation component has an ozone dosage of 2-5 mg / L, and achieves efficient mixing of ozone and water through a gas-liquid mixer. The 185nm / 254nm dual-band ultraviolet reactor has an ultraviolet dose of ≥400mJ / cm². 2 254nm ultraviolet radiation dose ≥600mJ / cm 2 ; The advanced oxidation reaction chamber is made of 316L stainless steel and has internal baffles. The hydraulic residence time is 10-15 minutes.

[0010] Preferably, the terminal purification unit includes a degassing membrane module, a mixed-bed ion exchanger, and an ultrafiltration membrane module; The degassing membrane module uses a polytetrafluoroethylene hydrophobic membrane to remove dissolved CO2 and residual ozone from the water. The mixed-bed ion exchanger is filled with nuclear-grade cation exchange resin and anion exchange resin, with a mixing ratio of 1:2. The ultrafiltration membrane module uses a PES ultrafiltration membrane with a molecular weight cutoff of 5000 Dalton.

[0011] Preferably, the intelligent monitoring and control unit includes a water quality monitoring sensor group, a PLC control system, and a data transmission module; The water quality monitoring sensor group includes an influent conductivity meter, a reverse osmosis product water conductivity meter, a TOC online monitor, a resistivity meter, and a residual ozone detector; The PLC control system realizes the automatic acquisition, display and adjustment of parameters of each unit; The data transmission module supports 4G / 5G and Ethernet communication, and uploads the operating data to the cloud management platform.

[0012] Preferably, the pretreatment unit includes a multi-media filter, a precision filter, and a dosing assembly; The multi-media filter includes a composite filter media of quartz sand and activated carbon, with a filtration accuracy of 5μm. The precision filter uses a 1μm melt-blown PP filter element; The dosing assembly includes a scale inhibitor dosing device and a pH adjuster dosing device, which controls the pH of the reverse osmosis feed water within the range of 6.5-7.5.

[0013] Preferably, the reverse osmosis desalination unit includes a first-stage high-pressure pump, a first-stage reverse osmosis membrane module, a second-stage high-pressure pump, and a second-stage reverse osmosis membrane module; The primary reverse osmosis membrane module uses a fouling-resistant reverse osmosis membrane with a desalination rate of ≥99.5%. The secondary reverse osmosis membrane module uses an ultra-low pressure reverse osmosis membrane with a desalination rate of ≥99.8% and a product water conductivity of ≤2μS / cm.

[0014] Another aspect of this invention discloses an integrated method for preparing ultrapure water based on deep degradation of TOC, comprising the following steps: S1: Raw water passes through a multi-media filter and a precision filter to remove suspended solids and large particulate impurities. Scale inhibitors and pH adjusters are added to adjust the influent pH to the range of 6.5-7.5. S2: The pretreated effluent enters the first-stage reverse osmosis membrane module via a first-stage high-pressure pump to remove most of the salt and organic matter. The first-stage permeate then enters the second-stage reverse osmosis membrane module via a second-stage high-pressure pump, and the permeate conductivity is controlled below 2μS / cm. S3: The secondary reverse osmosis permeate enters the advanced oxidation reaction chamber, where it is thoroughly mixed with ozone and then irradiated with 185nm / 254nm dual-band ultraviolet light to generate hydroxyl radicals, which completely oxidize and decompose the organic matter in the water. The TOC removal rate in this stage is ≥99%. S4: Water that has undergone advanced oxidation treatment passes sequentially through a degassing membrane, a mixed-bed ion exchanger, and an ultrafiltration membrane to remove residual dissolved gases, ions, and particulate impurities, producing ultrapure water; S5: Real-time monitoring of water quality parameters at each node. When the TOC content in the effluent exceeds the set threshold, it automatically increases the ozone dosage and ultraviolet power. When the resistivity is lower than the set threshold, it automatically triggers the mixed bed resin regeneration program.

[0015] Preferably, the ozone dosage in S3 is 2-5 mg / L, and the 185nm ultraviolet radiation dose is ≥400 mJ / cm. 2254nm ultraviolet radiation dose ≥600mJ / cm 2 The hydraulic residence time is 10-15 minutes.

[0016] Preferably, in step S5, the TOC threshold value of the effluent is set to 0.5 μg / L, the resistivity threshold value is set to 18.0 MΩ·cm, and the system recovery rate is controlled within the range of 65%-75%.

[0017] Preferably, the TOC content of the effluent is 0.1-0.5 μg / L, and the resistivity is ≥18.2 MΩ·cm (25℃).

[0018] The advantages of this invention compared to the prior art are: 1. High TOC removal efficiency: It adopts advanced oxidation technology of ozone + dual-band ultraviolet light, which has a high efficiency in generating hydroxyl radicals and can completely degrade recalcitrant organic pollutants. The TOC content of the effluent is stably controlled at 0.1-0.5μg / L, meeting the most stringent requirements for ultrapure water applications. 2. High integration: All processing units are integrated into the same skid-mounted cabinet, reducing the floor space by more than 40% compared to traditional processes, shortening the installation and commissioning cycle to 3-5 days, and enabling immediate use after installation; 3. Low operating costs: The system has a recovery rate of ≥70%, saves more than 20% of water compared to traditional processes, has a UV lamp life of up to 18,000 hours, extends the resin regeneration cycle to 6-12 months, and reduces overall operating costs by 30%; 4. High level of intelligence: Equipped with a complete online monitoring system and cloud management functions, it can achieve unattended operation, with a fault early warning accuracy rate of ≥95% and an 80% improvement in water quality stability; 5. Wide range of applications: The process parameters can be flexibly adjusted according to different influent water quality and effluent water requirements, making it suitable for ultrapure water supply scenarios in multiple industries such as electronics manufacturing, biomedicine, laboratories, and power. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an integrated ultrapure water preparation device based on deep degradation of TOC.

[0020] Figure 2 This is a schematic diagram of the framework structure of an integrated ultrapure water preparation device based on deep degradation of TOC.

[0021] Figure 3 This is a schematic diagram of the integrated preparation method of ultrapure water based on deep degradation of TOC.

[0022] As shown in the figure: 1. Skid-mounted cabinet, 2. Pretreatment unit, 3. Reverse osmosis desalination unit, 4. Advanced oxidation TOC deep degradation unit, 5. Terminal refining unit, 6. Intelligent monitoring and control unit. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings.

[0024] Combined with appendix Figure 1-3 The ultrapure water preparation device based on deep degradation of TOC shown includes a pretreatment unit 2, a reverse osmosis desalination unit 3, an advanced oxidation TOC deep degradation unit 4, a terminal purification unit 5, and an intelligent monitoring and control unit 6, all integrated in the same skid-mounted cabinet 1.

[0025] in: 1. Preprocessing unit 1.1 Multi-media filter: It adopts a composite filter media of quartz sand and activated carbon, and is equipped with a 50μm self-cleaning filter screen at the inlet end to remove suspended solids, colloids and large particulate impurities in the inlet water. The filtration accuracy is 5μm. 1.2 Precision Filter: A 1μm melt-blown PP filter element is used to perform secondary filtration on the pretreated effluent to protect the subsequent reverse osmosis membrane elements; 1.3 Chemical dosing components: including scale inhibitor dosing device and pH adjuster dosing device, which automatically adjusts the dosage according to the influent water quality to control the pH of the reverse osmosis influent within the range of 6.5-7.5.

[0026] 2. Reverse osmosis desalination unit 2.1 First-stage high-pressure pump: A stainless steel vertical multistage centrifugal pump with a head of 120-150m is used to provide working pressure for the reverse osmosis system; 2.2 Primary Reverse Osmosis Membrane Module: Utilizing Dow BW30-400IG anti-fouling reverse osmosis membranes, achieving a desalination rate ≥99.5%, removing over 98% of salts, organic matter, and microorganisms from the feed water, with a concentrate recovery rate controlled at 65%-75%; 2.3 Secondary high-pressure pump: with a head of 100-120m, providing pressure for the secondary reverse osmosis stage; 2.4 Secondary reverse osmosis membrane module: adopts ultra-low pressure reverse osmosis membrane with a desalination rate of ≥99.8%, further removing residual ions and small molecule organic matter in the water, and the conductivity of the product water is ≤2μS / cm (25℃).

[0027] 3. Advanced Oxidative TOC Deep Degradation Unit 3.1 Booster pump: pressurizes the secondary reverse osmosis permeate to 0.2-0.3 MPa and delivers it to the advanced oxidation reaction chamber; 3.2 Ozone Generating Component: A dielectric barrier discharge ozone generator is used, with an ozone output of 10-50 g / h and an ozone dosage controlled at 2-5 mg / L. A gas-liquid mixer is used to achieve efficient mixing of ozone and water, with a mixing efficiency ≥90%. 3.3 185nm / 254nm Dual-Band Ultraviolet Reactor: Employs a high-intensity amalgam lamp, with a 185nm ultraviolet dose ≥400mJ / cm². 2 254nm ultraviolet radiation dose ≥600mJ / cm 2 Simultaneously achieving ozone catalytic decomposition, hydroxyl radical generation, and bacterial inactivation, with hydroxyl radical generation ≥2×10 -5 mol / L; 3.4 Advanced oxidation reaction chamber: Made of 316L stainless steel, with internal baffles and a hydraulic retention time of 10-15 minutes to ensure that organic matter is fully oxidized and decomposed into CO2 and H2O.

[0028] 4. Terminal Refining Unit 4.1 Degassing membrane module: The membrane is made of polytetrafluoroethylene hydrophobic membrane to remove dissolved CO2 and excess ozone from the water, with CO2 content in the effluent ≤0.1mg / L; 4.2 Mixed-bed ion exchanger: filled with nuclear-grade cation exchange resin and anion exchange resin, with a mixing ratio of 1:2, to further remove residual ions in the water, with a product water resistivity ≥18.2 MΩ·cm (25℃). 4.3 Ultrafiltration membrane module: A PES ultrafiltration membrane with a molecular weight cutoff of 5000 Dalton is used to remove microbial remains, resin fragments and macromolecular colloids that may be present in the water, ensuring that the effluent is free of particulate impurities.

[0029] 5. Intelligent monitoring and control unit 5.1 Water quality monitoring sensor group: including influent conductivity meter, first-stage / second-stage reverse osmosis product water conductivity meter, TOC online monitor, resistivity meter, and residual ozone detector, with a sampling frequency of 1 time / second; 5.2 PLC Control System: The system adopts Siemens S7-1200 series PLC, equipped with a 7-inch color touch screen, to realize the automatic acquisition, display and adjustment of parameters of each unit; 5.3 Data transmission module: Supports 4G / 5G and Ethernet communication, and can upload operating data to the cloud management platform to realize remote monitoring and fault early warning; 5.4 Constant pressure water supply module: Equipped with a variable frequency water supply pump and a pressure buffer tank, the water supply pressure is stable at 0.2-0.4MPa, meeting the pressure requirements of the terminal water supply points.

[0030] In a specific implementation, this invention is based on the above-described apparatus and includes the following steps: 1. Pretreatment stage: Raw water passes through a multi-media filter and a precision filter to remove suspended solids and large particulate impurities. At the same time, scale inhibitors and pH adjusters are added to adjust the influent water quality to meet the reverse osmosis influent requirements. 2. Reverse osmosis desalination stage: The pretreated effluent enters the first-stage reverse osmosis membrane module through a first-stage high-pressure pump to remove most of the salt and organic matter. The first-stage permeate then enters the second-stage reverse osmosis membrane module through a second-stage high-pressure pump for further desalination. The permeate conductivity is controlled below 2μS / cm. 3. TOC Deep Degradation Stage: The secondary reverse osmosis permeate enters the advanced oxidation reaction chamber, where it is first thoroughly mixed with ozone, and then irradiated with dual-band ultraviolet light to generate highly oxidizing hydroxyl radicals, which completely oxidize and decompose the organic matter in the water into CO2 and water. The TOC removal rate in this stage is ≥99%. 4. Terminal purification stage: The water treated by advanced oxidation first passes through a degassing membrane to remove dissolved CO2 and residual ozone, then enters a mixed bed ion exchanger to remove residual ions, and the resistivity of the produced water reaches 18.2 MΩ·cm. Finally, it passes through an ultrafiltration membrane to remove particulate impurities and microorganisms. Intelligent control phase: The system monitors water quality parameters at each node in real time. When the TOC content in the effluent exceeds the set threshold (0.5 μg / L), it automatically increases the ozone dosage and ultraviolet power, while adjusting the reverse osmosis recovery rate to ensure stable effluent quality. When the resistivity is lower than 18.0 MΩ·cm, it automatically triggers the mixed bed resin regeneration program.

[0031] In practical use: Project Background: A 12-inch wafer fabrication plant with municipal tap water as its feed water source, requiring an ultrapure water production capacity of 10m³. 3 / h, effluent resistivity ≥18.2 MΩ·cm, TOC ≤0.5μg / L, number of particles ≥0.05μm ≤1 / mL.

[0032] Device configuration: 1. Pre-processing unit: Processing capacity 15m³ 3 / h, multi-media filter diameter 1200mm, precision filter 10-core pack; 2. Reverse osmosis unit: 12 BW30-400IG membranes for the first-stage reverse osmosis membrane module, and 8 LP-4040 membranes for the second-stage reverse osmosis membrane module; 3. Advanced oxidation unit: Ozone generator output 30g / h, dual-band ultraviolet reactor power 600W, reaction chamber volume 2m³ 3 ; 4. Terminal refining unit: 2 degassed membranes, mixed bed resin loading 0.8m³ 3 4 ultrafiltration membranes.

[0033] Operating parameters: System recovery rate: 72% • Ozone dosage: 3 mg / L • Ultraviolet radiation dose: 185nm 450mJ / cm 2254nm 650mJ / cm 2 Hydraulic retention time: 12 min Running result: • Water resistivity: Stable at 18.22-18.25 MΩ·cm (25℃) TOC content: 0.12-0.35 μg / L, average 0.21 μg / L • Particle count: ≥0.05μm particles average 0.3 / mL • After 12 months of continuous operation, the water quality compliance rate reached 100%, with a comprehensive operating cost of 3.2 yuan / m³. 3 It saves 32% compared to traditional processes.

[0034] Example 2: Ultrapure Water Preparation Project in a Biomedical R&D Center Laboratory Project Background: A new drug research and development laboratory, with reverse osmosis pure water as the feed water, requiring an ultrapure water production capacity of 2m³ / s. 3 / h, effluent TOC≤0.1μg / L, no pyrogen, no RNase / DNase.

[0035] Device configuration: 1. Pre-treatment unit: 5μm precision filter, processing capacity 3m³ / min 3 / h; 2. Secondary reverse osmosis unit: 4 low-pressure reverse osmosis membranes; 3. Advanced oxidation unit: Ozone generator output 10g / h, dual-band ultraviolet reactor power 200W, reaction chamber volume 0.5m³ 3 ; 4. Terminal refining unit: 1 degassed membrane unit, 0.2m³ of nuclear-grade mixed-bed resin. 3 Two ultrafiltration membranes, terminal ultrafiltration (5000 Dalton).

[0036] Operating parameters: System recovery rate: 75% • Ozone dosage: 4 mg / L • Ultraviolet radiation dose: 185nm 500mJ / cm 2 254nm 700mJ / cm 2 Running result: • The TOC content in the effluent remained stable at 0.05-0.09 μg / L, with an average of 0.07 μg / L. • No pyrogen, no RNase / DNase detected • Resistivity is stable above 18.2 MΩ·cm • The resin regeneration cycle is 10 months, and the operation is stable.

[0037] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. An integrated ultrapure water preparation device based on deep degradation of TOC, characterized in that: It includes a pretreatment unit (2), a reverse osmosis desalination unit (3), an advanced oxidation TOC deep degradation unit (4), a terminal purification unit (5), and an intelligent monitoring and control unit (6) integrated in the same skid-mounted cabinet (1). The pretreatment unit (2) removes suspended solids, colloids and large particulate impurities from the influent and adjusts the pH value of the influent. The reverse osmosis desalination unit (3) is connected to the pretreatment unit (2) to remove salt, organic matter and microorganisms from the water; The advanced oxidation TOC deep degradation unit (4) is connected to the reverse osmosis desalination unit (3) to oxidize and decompose organic matter in water into CO2 and H2O; The terminal refining unit (5) is connected to the advanced oxidation TOC deep degradation unit (4) to remove residual ions, dissolved gases and particulate impurities in the water; The intelligent monitoring and control unit (6) monitors the water quality parameters of each node in real time and automatically adjusts the operating parameters.

2. The integrated ultrapure water preparation device based on deep degradation of TOC according to claim 1, characterized in that: The advanced oxidation TOC deep degradation unit (4) includes an ozone generation component, a 185nm / 254nm dual-band ultraviolet reactor, and an advanced oxidation reaction chamber. The ozone generation component has an ozone dosage of 2-5 mg / L, and achieves efficient mixing of ozone and water through a gas-liquid mixer. The 185nm / 254nm dual-band ultraviolet reactor has an ultraviolet dose of ≥400mJ / cm². 2 254nm ultraviolet radiation dose ≥600mJ / cm 2 ; The advanced oxidation reaction chamber is made of 316L stainless steel and has internal baffles. The hydraulic residence time is 10-15 minutes.

3. The integrated ultrapure water preparation device based on deep degradation of TOC according to claim 1, characterized in that: The terminal refining unit (5) includes a degassing membrane assembly, a mixed-bed ion exchanger, and an ultrafiltration membrane assembly. The degassing membrane module uses a polytetrafluoroethylene hydrophobic membrane to remove dissolved CO2 and residual ozone from the water. The mixed-bed ion exchanger is filled with nuclear-grade cation exchange resin and anion exchange resin, with a mixing ratio of 1:

2. The ultrafiltration membrane module uses a PES ultrafiltration membrane with a molecular weight cutoff of 5000 Dalton.

4. The integrated ultrapure water preparation device based on deep degradation of TOC according to claim 1, characterized in that: The intelligent monitoring and control unit (6) includes a water quality monitoring sensor group, a PLC control system and a data transmission module; The water quality monitoring sensor group includes an influent conductivity meter, a reverse osmosis product water conductivity meter, a TOC online monitor, a resistivity meter, and a residual ozone detector; The PLC control system realizes the automatic acquisition, display and adjustment of parameters of each unit; The data transmission module supports 4G / 5G and Ethernet communication, and uploads the operating data to the cloud management platform.

5. The integrated ultrapure water preparation device based on deep degradation of TOC according to claim 1, characterized in that: The pretreatment unit (2) includes a multi-media filter, a precision filter, and a dosing assembly; The multi-media filter includes a composite filter media of quartz sand and activated carbon, with a filtration accuracy of 5μm. The precision filter uses a 1μm melt-blown PP filter element; The dosing assembly includes a scale inhibitor dosing device and a pH adjuster dosing device, which controls the pH of the reverse osmosis feed water within the range of 6.5-7.

5.

6. The integrated ultrapure water preparation device based on deep degradation of TOC according to claim 1, characterized in that: The reverse osmosis desalination unit (3) includes a first-stage high-pressure pump, a first-stage reverse osmosis membrane module, a second-stage high-pressure pump, and a second-stage reverse osmosis membrane module; The primary reverse osmosis membrane module uses a fouling-resistant reverse osmosis membrane with a desalination rate of ≥99.5%. The secondary reverse osmosis membrane module uses an ultra-low pressure reverse osmosis membrane with a desalination rate of ≥99.8% and a product water conductivity of ≤2μS / cm.

7. An integrated method for preparing ultrapure water based on deep degradation of TOC, using the apparatus as described in any one of claims 1-6, characterized in that: Includes the following steps: S1: Raw water passes through a multi-media filter and a precision filter to remove suspended solids and large particulate impurities. Scale inhibitors and pH adjusters are added to adjust the influent pH to the range of 6.5-7.

5. S2: The pretreated effluent enters the first-stage reverse osmosis membrane module via a first-stage high-pressure pump to remove most of the salt and organic matter. The first-stage permeate then enters the second-stage reverse osmosis membrane module via a second-stage high-pressure pump, and the permeate conductivity is controlled below 2μS / cm. S3: The secondary reverse osmosis permeate enters the advanced oxidation reaction chamber, where it is thoroughly mixed with ozone and then irradiated with 185nm / 254nm dual-band ultraviolet light to generate hydroxyl radicals, which completely oxidize and decompose the organic matter in the water. The TOC removal rate in this stage is ≥99%. S4: Water that has undergone advanced oxidation treatment passes sequentially through a degassing membrane, a mixed-bed ion exchanger, and an ultrafiltration membrane to remove residual dissolved gases, ions, and particulate impurities, producing ultrapure water; S5: Real-time monitoring of water quality parameters at each node. When the TOC content in the effluent exceeds the set threshold, it automatically increases the ozone dosage and ultraviolet power. When the resistivity is lower than the set threshold, it automatically triggers the mixed bed resin regeneration program.

8. The integrated method for preparing ultrapure water based on deep degradation of TOC according to claim 1, characterized in that: The ozone dosage in S3 is 2-5 mg / L, and the 185nm ultraviolet radiation dose is ≥400 mJ / cm². 2 254nm ultraviolet radiation dose ≥600mJ / cm 2 The hydraulic residence time is 10-15 minutes.

9. The integrated method for preparing ultrapure water based on deep degradation of TOC according to claim 1, characterized in that: The TOC threshold for the effluent in S5 is set at 0.5 μg / L, the resistivity threshold is set at 18.0 MΩ·cm, and the system recovery rate is controlled within the range of 65%-75%.

10. The integrated method for preparing ultrapure water based on deep degradation of TOC according to claim 1, characterized in that: The effluent has a TOC content of 0.1-0.5 μg / L and a resistivity of ≥18.2 MΩ·cm (25℃).

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