Method and device for carrying out water treatment by combining vacuum ultraviolet with ultrafiltration

Abstract

The invention relates to a vacuum ultraviolet combined ultrafiltration water treatment method and device, and the method comprises the following steps: carrying out radiation treatment on to-be-treated water: simultaneously emitting dual-wavelength ultraviolet rays of 185 nm and 254 nm through a single-ended vacuum ultraviolet lamp (3), and generating hydroxyl radicals through the ultraviolet rays of 185 nm to degrade organic matters in the to-be-treated water, the water to be treated is disinfected through 254 nm ultraviolet rays; and performing ultrafiltration: filtering the water subjected to radiation treatment in the step S1 through an ultrafiltration membrane assembly (5). Compared with the prior art, the method can solve the problems of disinfection by-products, water toxicity, membrane pollution and the like caused by organic matters in the water and wastewater treatment or disinfection process, and can be used in the field of advanced treatment of drinking water and sewage.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to a method and apparatus for water treatment using a combination of vacuum ultraviolet and ultrafiltration. Background Technology

[0002] With rapid industrialization and urbanization, water pollution has become increasingly serious, making advanced treatment of water and wastewater to ensure water quality safety an urgent priority. However, existing water and wastewater treatment and disinfection processes present numerous problems. On the one hand, organic matter in water easily generates disinfection byproducts during disinfection, which are often toxic and pose a threat to human health and the ecological environment. On the other hand, membrane fouling is a prevalent and difficult-to-solve problem in membrane treatment technology. Membrane fouling leads to decreased membrane flux, reduced treatment efficiency, and shortened membrane lifespan, thereby increasing treatment costs.

[0003] Currently, common methods for addressing disinfection byproducts and water toxicity caused by organic matter include improving disinfection processes and adding chemical agents. However, these methods may introduce new environmental problems or increase treatment costs. For membrane fouling, common mitigation measures include physical cleaning, chemical cleaning, and optimizing membrane materials; however, these methods often have limited effectiveness or are complex to operate. Therefore, developing a novel advanced water and wastewater treatment technology that can effectively solve the above problems is of significant practical importance. Summary of the Invention

[0004] The purpose of this invention is to provide a method and apparatus for water treatment using vacuum ultraviolet combined with ultrafiltration, which effectively solves the problems of disinfection byproducts, water toxicity, and membrane fouling caused by organic matter during the water treatment process.

[0005] The objective of this invention can be achieved through the following technical solutions: This invention provides a method for water treatment using a combination of vacuum ultraviolet and ultrafiltration, comprising the following steps: S1. Radiation treatment of the water to be treated: A single-ended vacuum ultraviolet lamp emits dual-wavelength ultraviolet rays of 185 nm and 254 nm simultaneously. The 185 nm ultraviolet rays generate hydroxyl radicals to degrade organic matter in the water to be treated, and the 254 nm ultraviolet rays disinfect the water to be treated. S2, Ultrafiltration: Filtration of water after radiation treatment in step S1 using an ultrafiltration membrane module.

[0006] Preferably, the water to be treated includes drinking water and wastewater.

[0007] More preferably, the water to be treated includes effluent from a waterworks filter or effluent from a secondary sedimentation tank of a wastewater treatment plant, in order to achieve a deep treatment effect for both water and wastewater.

[0008] Preferably, in step S1, the radiation treatment time is 10-60 min and the radiation intensity is 1-3 W / L.

[0009] More preferably, in step S1, the radiation time of the single-ended vacuum ultraviolet lamp is set according to the different water quality of the water source. Generally, for water with low organic matter content (dissolved organic carbon content is less than 10 mg / L), the radiation time is controlled at 10-20 minutes; for wastewater with high organic matter content (dissolved organic carbon content is more than 10 mg / L), the radiation time is extended to 30-60 minutes.

[0010] More preferably, in step S1, the radiation treatment step involves adjusting the radiation intensity and radiation time of the single-ended vacuum ultraviolet lamp to control the degradation and disinfection effects of organic matter.

[0011] Preferably, step S1 further includes adding hydrogen peroxide to synergistically generate hydroxyl radicals to degrade organic matter in the water to be treated, wherein the concentration of hydrogen peroxide added is 0.5-2 mmol / L.

[0012] More preferably, in step S1, the concentration of hydrogen peroxide added is adjusted according to the water quality and organic matter content of the water to be treated, and the ideal effect can be achieved with a concentration not exceeding 2 mmol / L.

[0013] Preferably, in step S2, the ultrafiltration membrane module is selected from any one of flat sheet membranes, hollow fiber membranes, and ceramic membranes, with a membrane pore size range of 0.01-0.1 μm and a membrane flux controlled at 80-120 L / m³. 2 ·h.

[0014] Preferably, in step S2, the operating pressure of the ultrafiltration membrane module is controlled at 0.1-0.3 MPa.

[0015] More preferably, in step S2, the ultrafiltration membrane module is cleaned and maintained regularly to maintain its filtration performance.

[0016] More preferably, in step S2, the ultrafiltration membrane module is backwashed periodically. The backwashing cycle is determined according to the fouling of the membrane, generally once every 2-4 hours of operation, and the backwashing time is 1-2 minutes.

[0017] More preferably, the water quality of different sources is analyzed in detail, including indicators such as pH value, turbidity, organic matter content, and inorganic matter content. Based on the influent water quality, the water is pretreated, such as by adjusting pH value, sedimentation, and filtration, to meet the influent requirements of the device.

[0018] The present invention also provides an apparatus for the method of water treatment using vacuum ultraviolet combined ultrafiltration, comprising, in sequence along the direction of water transport, an inlet pump for transporting the water to be treated to a radiation reaction tank, a radiation reaction tank for radiating the water to be treated, a membrane tank for ultrafiltration of the water to be treated, and an outlet pump for discharging the water after radiation treatment and ultrafiltration treatment; wherein, a single-ended vacuum ultraviolet lamp is installed above the radiation reaction tank, and an ultrafiltration membrane assembly is disposed inside the membrane tank.

[0019] Preferably, the radiation reaction tank is also equipped with a stirring device, and the radiation reaction tank is made of stainless steel.

[0020] Preferably, a liquid level controller is also provided inside the membrane tank. The liquid level controller includes a liquid level sensor and a control system installed on the inner wall of the membrane tank. The control system is connected to the liquid level sensor and the water pump signal, and the water pump is a metering pump.

[0021] More preferably, the liquid level sensor is used to detect the liquid level height of the water to be treated in the membrane tank in real time.

[0022] More preferably, the control system is used to receive signals from sensors, compare them with preset values ​​(setpoints), and then output control commands to control the opening and closing of the water pump.

[0023] More preferably, the control system includes a PLC control system.

[0024] More preferably, the liquid level controller is equipped with a high liquid level and a low liquid level. When the liquid level sensor detects that the liquid level in the membrane tank has reached the high liquid level, the control system sends a signal to start the water pump to discharge the water treated by the ultrafiltration membrane module. When the liquid level sensor detects that the liquid level in the membrane tank is lower than the low liquid level, the control system controls the water pump to shut down to prevent the ultrafiltration membrane module from being damaged due to cavitation and to ensure the normal operation and service life of the membrane module.

[0025] More preferably, the high liquid level is set 10-20 cm above the top of the ultrafiltration membrane module to ensure that the membrane module is always below the liquid level and to prevent cavitation.

[0026] More preferably, the low liquid level is set at 5-10 cm above the ultrafiltration membrane module. When the liquid level is lower than this value, the water pump is shut off in time to protect the membrane module.

[0027] Preferably, the output end of the inlet pump is connected to the inlet of the radiation reaction tank, the outlet of the radiation reaction tank is connected to the inlet of the membrane tank, and the outlet of the membrane tank is connected to the input end of the outlet pump.

[0028] Preferably, the membrane tank is further provided with an aeration device or a stirring device, which is installed at the bottom of the membrane tank and located below the ultrafiltration membrane module.

[0029] More preferably, the ultrafiltration membrane module enhances the hydraulic scouring of the membrane surface through aeration or stirring to reduce concentration polarization and thereby improve filtration efficiency.

[0030] More preferably, the method for water treatment using vacuum ultraviolet combined with ultrafiltration includes the following steps: a) Water intake procedure: The water to be treated is transported to the radiation reaction tank by the water intake pump; b) Radiation treatment steps: In the radiation reaction tank, the water is irradiated with dual-wavelength ultraviolet light emitted by a single-ended vacuum ultraviolet lamp to generate hydroxyl radicals to degrade organic matter, reduce water toxicity, and disinfect the water at the same time. c) Optionally, hydrogen peroxide addition step: In the radiation treatment step, a low concentration of hydrogen peroxide is added to the radiation reaction tank to enhance the degradation effect of organic matter; d) Membrane filtration step: The radiation-treated water is transported to the membrane tank and filtered through an ultrafiltration membrane module; e) Liquid level control steps: In the membrane tank, the liquid level in the membrane tank is controlled by the liquid level controller. When the liquid level reaches the set value, the effluent pump is started to discharge the treated water; when the liquid level is lower than the set value, the effluent pump is turned off to prevent the ultrafiltration membrane module from being evacuated.

[0031] More preferably, the apparatus for water treatment using vacuum ultraviolet combined with ultrafiltration includes: an inlet pump for conveying water and wastewater to a radiation reaction tank; a radiation reaction tank containing a single-ended vacuum ultraviolet lamp, which uses high-energy photons from dual-wavelength vacuum ultraviolet lamps (185 nm and 254 nm) to irradiate water, generating hydroxyl radicals to degrade organic matter; a membrane tank connected to the radiation reaction tank for containing water treated by the radiation reaction tank; an ultrafiltration membrane module disposed in the membrane tank for further filtration of the irradiated water; a level controller disposed in the membrane tank for controlling the level in the membrane tank to prevent the ultrafiltration membrane module from evacuating; and an outlet pump linked to the level controller for discharging the water treated by the ultrafiltration membrane module.

[0032] This invention organically combines vacuum ultraviolet radiation with ultrafiltration membrane filtration, fully leveraging the advantages of vacuum ultraviolet radiation in organic matter degradation and disinfection, and the role of ultrafiltration membranes in impurity retention and water purification. Simultaneously, a liquid level controller ensures stable operation of the device. This invention is applicable to the advanced treatment of drinking water and various types of wastewater, effectively solving many problems in existing treatment technologies, and offering significant environmental and economic benefits. It provides an innovative and efficient solution for water treatment.

[0033] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention provides a method and apparatus for water treatment by combining vacuum ultraviolet radiation and ultrafiltration membrane filtration, which effectively solves the problems of disinfection byproducts, water toxicity and membrane fouling caused by organic matter in the water treatment process.

[0034] (2) This invention utilizes the high-energy photons of a dual-wavelength vacuum ultraviolet lamp to irradiate the water to be treated. Hydroxyl radicals are generated by 185 nm ultraviolet light to degrade organic matter, and the water is disinfected by 254 nm ultraviolet light. No additional disinfectant is added, thus avoiding the generation of disinfection byproducts.

[0035] (3) The present invention can generate more hydroxyl radicals by synergistically adding hydrogen peroxide, which further enhances the degradation of organic matter.

[0036] (4) The present invention can reduce the 4-NQO equivalent concentration in wastewater from 11.66 μg / L to 0.98 μg / L, achieving efficient organic degradation and significantly reducing water toxicity. At the same time, the water treated by vacuum ultraviolet radiation and hydrogen peroxide enters the ultrafiltration membrane module for filtration. Compared with the direct ultrafiltration of untreated raw water, the flux of the treated ultrafiltration membrane is significantly improved. The present invention can effectively solve the membrane fouling problem.

[0037] (5) In order to prevent the membrane module from being evacuated, the present invention sets a liquid level controller in the membrane tank to control the start of the water pump, so as to ensure the stable operation of the device. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the device structure of the present invention.

[0039] Figure 2 The reduction of genotoxicity of surface water by UV and VUV radiation for 30 minutes.

[0040] Figure 3 The graph shows the change in membrane flux after 30 min of VUV combined with hydrogen peroxide treatment, taking bovine serum albumin membrane fouling as an example.

[0041] Figure 4 The graph shows the change in membrane flux after 30 min of UV combined with hydrogen peroxide treatment, taking bovine serum albumin membrane contamination as an example.

[0042] Figure 1 In the middle: 1-Inlet pump; 2-Radiation reaction tank; 3-Single-end vacuum ultraviolet lamp; 4-Membrane tank; 5-Ultrafiltration membrane module; 6-Level controller; 7-Outlet pump.

[0043] Figure 2Genotoxicity is measured in 4-NQO equivalent concentrations.

[0044] Figure 3 Changes in membrane fouling are expressed as normalized membrane flux values. Detailed Implementation

[0045] This embodiment is implemented based on the technical solution of the present invention, and provides detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiment.

[0046] Unless otherwise specified, the reagents, methods, instruments, and equipment used in this invention are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0047] A method for water treatment using vacuum ultraviolet combined ultrafiltration includes the following steps: a) First, turn on the inlet pump 1 to transport the water to be treated and the wastewater to the radiation reaction tank 2, and control the appropriate inlet flow rate to ensure that the water flows into the reaction tank evenly.

[0048] b) Next, the stirring device in the radiation reaction tank 2 is activated to achieve homogenization. Simultaneously, the single-ended vacuum ultraviolet lamp 3 is turned on, emitting both 185nm and 254nm vacuum ultraviolet light to irradiate the water. During this process, depending on the quality of the water to be treated, a low-concentration hydrogen peroxide dosing system can be activated to add an appropriate amount of hydrogen peroxide to the radiation reaction tank 2 to enhance the degradation effect of organic matter.

[0049] c) Then, the water treated by radiation enters the membrane tank 4 and is filtered through the ultrafiltration membrane module 5. During operation, the ultrafiltration membrane module 5 can be cleaned and maintained periodically to maintain its filtration performance and extend its service life.

[0050] d) Finally, the liquid level controller 6 in the membrane tank 4 monitors the liquid level in real time and controls the start and stop of the effluent pump 7 according to the liquid level change, so as to discharge the treated water from the device and complete the entire deep treatment process of water and wastewater.

[0051] The device for water treatment based on the above-mentioned vacuum ultraviolet combined ultrafiltration method mainly consists of an inlet pump 1, a radiation reaction tank 2, a single-end vacuum ultraviolet lamp 3 (brand: Shenxing, the model can be selected according to the amount of water to be treated, and the power can be selected to meet the radiation intensity requirements), a membrane tank 4, an ultrafiltration membrane module 5, a liquid level controller 6 (brand: Pump Master, model: D1Y) and an outlet pump 7.

[0052] The water inlet pump 1 serves as the water inlet component of the device. One end of it is connected to the water to be treated, and the other end is connected to the inlet of the radiation reaction tank 2. It can stably and continuously transport the water to be treated and the wastewater into the radiation reaction tank 2, ensuring the continuity of the treatment process.

[0053] Radiation reaction tank 2 is the core area for vacuum ultraviolet radiation treatment. It is equipped with a stirring device to ensure thorough mixing of the water entering the tank with subsequently introduced substances (such as hydrogen peroxide), guaranteeing uniform treatment results. A single-ended vacuum ultraviolet lamp 3 is installed above the radiation reaction tank, capable of emitting ultraviolet light of a specific wavelength.

[0054] The single-ended vacuum ultraviolet lamp 3 is one of the key components of the device, emitting vacuum ultraviolet light with two main wavelengths: 185nm and 254nm. The 185nm ultraviolet light has high energy, enabling it to cause photolysis of oxygen molecules in water, producing reactive substances such as ozone. This, in turn, triggers a series of free radical chain reactions, generating highly oxidizing hydroxyl radicals. These hydroxyl radicals can non-selectively attack organic matter in the water, decomposing it into smaller molecules, or even completely mineralizing it into carbon dioxide and water, effectively reducing water toxicity. The 254nm ultraviolet light, on the other hand, has a good killing effect on microorganisms in the water, achieving water disinfection without the need for additional chemical disinfectants and avoiding the generation of disinfection byproducts.

[0055] Membrane tank 4 is connected to radiation reaction tank 2 and is used to receive water treated by vacuum ultraviolet radiation. Membrane tank 4 is equipped with an ultrafiltration membrane module 5, which can be a flat sheet membrane, hollow fiber membrane, or ceramic membrane, with a pore size range of 0.01-0.1 μm and a membrane flux controlled at 80-120 L / m³. 2 •h. A reasonable flux setting ensures treatment efficiency while avoiding excessive membrane fouling or wasting membrane modules. Ultrafiltration membranes effectively remove suspended solids, colloids, and large organic molecules from water, further purifying the water.

[0056] Experiments revealed that cavitation of the membrane module would cause a sudden increase in transmembrane pressure, damaging the membrane module. A level controller 6 is installed inside the membrane tank 4 to monitor the liquid level changes in the tank in real time. When the liquid level reaches the set high value, the level control unit sends a signal to start the effluent pump 7, discharging the water treated by the ultrafiltration membrane module 5. When the liquid level falls below the set low value, the level controller 6 controls the effluent pump 7 to shut off, preventing damage to the ultrafiltration membrane module 5 due to cavitation and ensuring the normal operation and service life of the membrane module.

[0057] Furthermore, this device can also be equipped with a low-concentration hydrogen peroxide dosing system. Under vacuum ultraviolet light excitation, hydrogen peroxide can generate more hydroxyl radicals, thereby enhancing its ability to oxidize and decompose organic matter. The concentration of hydrogen peroxide added is generally controlled to be no higher than 2 mmol / L, which achieves the desired treatment effect while avoiding potential problems caused by excessive dosage.

[0058] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0059] Example 1 Device construction related implementation methods like Figure 1 As shown, this embodiment first details the overall layout of the device. The device mainly includes an inlet pump 1, a radiation reaction tank 2, a single-ended vacuum ultraviolet lamp 3, a membrane tank 4, an ultrafiltration membrane module 5, a liquid level controller 6, and an outlet pump 7.

[0060] The flow rate and head of inlet pump 1 are determined based on the actual water volume to be treated and the head loss. Inlet pump 1 is connected to the inlet of radiation reaction tank 2 via a pipeline.

[0061] Radiation reaction tank 2 is made of stainless steel and has an internal stirring device, which requires anti-corrosion treatment.

[0062] Single-ended vacuum ultraviolet lamps 3 are installed inside the radiation reaction tank 2, and the number of ultraviolet lamps is adjusted according to the amount of water to be treated.

[0063] Membrane tank 4 is connected to radiation reaction tank 2 by a pipe, and valves are installed on the pipe to control the water flow.

[0064] The ultrafiltration membrane module 5 is installed inside the membrane tank 4. It adopts a hollow fiber membrane structure with a membrane pore size of 0.01-0.1μm and a membrane flux controlled at 80-120L / m³. 2 ·h.

[0065] The liquid level controller 6 is installed at a suitable height on the inner wall of the membrane tank 4 and is linked to the water pump 7 for control via a signal line.

[0066] The outlet pump 7 is a metering pump, which has high head and accuracy.

[0067] Implementation methods related to operating parameters This implementation method mainly involves the influent water quality requirements and treatment parameter settings during device operation.

[0068] Detailed analysis of different water sources is conducted, including indicators such as pH value, turbidity, organic matter content, and inorganic matter content. Based on the influent water quality, pretreatment is performed, such as pH adjustment, sedimentation, and filtration, to meet the influent requirements of the equipment.

[0069] Depending on the water quality of different water sources, the radiation time of the single-ended vacuum ultraviolet lamp 3 is set. Generally, for water with low organic content, the radiation time can be controlled at 10-20 minutes; for wastewater with high organic content, the radiation time is extended to 30-60 minutes.

[0070] In actual operation, if the radiation time is difficult to adjust due to design limitations, the number of vacuum ultraviolet lamps can be increased according to the radiation dose formula.

[0071] Radiation dose (H) = radiation intensity (Φ) × radiation time (t).

[0072] For example, if the original design radiation time is 30 minutes and the radiation intensity is a certain value, when it is necessary to shorten the treatment time or improve the treatment effect, the number of lamps can be increased by calculation to keep the total radiation dose constant or increase. Assume that originally 2 lamps were used, the radiation intensity was Φ1, the radiation time was t1 = 30 minutes, and the total radiation dose H = 2Φ1 × 30; if the time is to be shortened to t2 = 2 minutes while keeping the total radiation dose constant, then the required number of lamps n = (2Φ1 × 30) / (Φ1 × 20) = 3 lamps (assuming the radiation intensity of the newly added lamps is the same as the original lamps).

[0073] The addition of hydrogen peroxide during radiation treatment is explained in detail. When hydrogen peroxide needs to be added to enhance the degradation of organic matter, the concentration of hydrogen peroxide added should be adjusted according to the water quality and organic matter content of the water to be treated. Generally, the concentration is controlled between 0.5-2 mmol / L.

[0074] Hydrogen peroxide is accurately added to the radiation reaction tank 2 via a metering pump, the flow rate of which is set according to the concentration and the amount of water to be treated.

[0075] The operating parameters of the ultrafiltration membrane module 5 have a significant impact on the treatment effect and the membrane's lifespan. The operating pressure of the ultrafiltration membrane module 5 should be controlled between 0.1 and 0.3 MPa. Excessive pressure will lead to increased membrane fouling, while excessively low pressure will affect the treatment efficiency.

[0076] The ultrafiltration membrane module 5 should be backwashed regularly. The backwashing cycle is determined according to the fouling of the membrane, generally once every 2-4 hours of operation, and the backwashing time is 1-2 minutes.

[0077] The set value of the liquid level controller 6 is determined according to the safe operation requirements of the ultrafiltration membrane module 5.

[0078] The high liquid level is set 10-20cm above the top of the ultrafiltration membrane module 5 to ensure that the membrane module is always below the liquid level and to prevent cavitation. The low liquid level is set 5-10cm above the ultrafiltration membrane module 5. When the liquid level is below this value, the outlet water pump 7 should be turned off in time to protect the membrane module.

[0079] Operation process related implementation methods This embodiment describes the device startup process in detail. First, check whether all components of the device are normal and whether the pipe connections are tight and leak-free.

[0080] Turn on the inlet pump 1 to slowly introduce the surface water (with a dissolved organic carbon content of approximately 6 mg / L) filtered through a 0.45 μm glass fiber membrane into the radiation reaction tank 2. Simultaneously, start the stirring device in the radiation reaction tank 2 to ensure thorough mixing of the water. Once the water level in the radiation reaction tank 2 reaches a certain height, turn on the single-ended vacuum ultraviolet lamp 3 for radiation treatment. The water after radiation treatment (generally set for 30 minutes) enters the membrane tank 4. When the liquid level in the membrane tank 4 reaches the high-level set value, start the outlet pump 7 to discharge the treated water.

[0081] Figure 2 As shown, the genotoxic equivalent concentration of 4-nitroquinoline-n-oxide (4-NQO) in the raw water was 11.66 μg / L. After 30 min of UV (ultraviolet) irradiation, the genotoxic equivalent concentration decreased to 1.52 μg / L. After 30 min of VUV (vacuum ultraviolet) irradiation, the genotoxic equivalent concentration decreased to 0.98 μg / L. Because VUV radiation has a shorter wavelength and higher photon energy than UV radiation, it has a greater effect on reducing the toxicity of natural organic compounds. The manufacturing and operating costs of VUV lamps are almost equivalent to those of UV lamps, thus their application effect is better.

[0082] like Figures 3-4 As shown, after ultrafiltration was performed with 2 mmol / L hydrogen peroxide during UV radiation or VUV radiation, the membrane flux of the ultrafiltration membrane module 5 was significantly increased compared with that of direct ultrafiltration without radiation treatment.

[0083] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for water treatment using a combination of vacuum ultraviolet light and ultrafiltration, characterized in that, Includes the following steps: S1. Radiation treatment of the water to be treated: The single-ended vacuum ultraviolet lamp (3) emits dual-wavelength ultraviolet rays of 185 nm and 254 nm simultaneously. The 185 nm ultraviolet rays generate hydroxyl radicals to degrade the organic matter in the water to be treated, and the 254 nm ultraviolet rays disinfect the water to be treated. S2, Ultrafiltration: The water after radiation treatment in step S1 is filtered through an ultrafiltration membrane module (5).

2. The method for water treatment using vacuum ultraviolet combined ultrafiltration according to claim 1, characterized in that, In step S1, the radiation treatment time is 10-60 min, and the radiation treatment intensity is 1-3 W / L.

3. The method for water treatment using vacuum ultraviolet combined ultrafiltration according to claim 1, characterized in that, Step S1 also includes adding hydrogen peroxide to synergistically generate hydroxyl radicals to degrade organic matter in the water to be treated, wherein the concentration of hydrogen peroxide added is 0.5-2 mmol / L.

4. The method for water treatment using vacuum ultraviolet combined ultrafiltration according to claim 1, characterized in that, In step S2, the ultrafiltration membrane module (5) is selected from any one of flat sheet membrane, hollow fiber membrane, and ceramic membrane, with a membrane pore size range of 0.01-0.1 μm and a membrane flux controlled at 80-120 L / m³. 2 ·h.

5. The method for water treatment using vacuum ultraviolet combined ultrafiltration according to claim 1, characterized in that, In step S2, the operating pressure of the ultrafiltration membrane module (5) is controlled at 0.1-0.3 MPa.

6. An apparatus for water treatment using a method of vacuum ultraviolet combined ultrafiltration as described in any one of claims 1-5, characterized in that, Along the direction of water transport, the system includes, in sequence, an inlet pump (1) for transporting water to be treated to the radiation reaction tank (2), a radiation reaction tank (2) for radiation treatment of water to be treated, a membrane tank (4) for ultrafiltration treatment of water to be treated, and an outlet pump (7) for discharging water after radiation treatment and ultrafiltration treatment; wherein, a single-end vacuum ultraviolet lamp (3) is installed above the radiation reaction tank (2), and an ultrafiltration membrane assembly (5) is installed inside the membrane tank (4).

7. The apparatus according to claim 6, characterized in that, The radiation reaction tank (2) is also equipped with a stirring device, and the radiation reaction tank (2) is made of stainless steel.

8. The apparatus according to claim 6, characterized in that, The membrane tank (4) is also equipped with a liquid level controller (6). The liquid level controller (6) includes a liquid level sensor and a control system installed on the inner wall of the membrane tank (4). The control system is connected to the liquid level sensor and the water pump (7) respectively. The water pump (7) is a metering pump.

9. The apparatus according to claim 6, characterized in that, The output end of the inlet pump (1) is connected to the inlet of the radiation reaction tank (2), the outlet of the radiation reaction tank (2) is connected to the inlet of the membrane tank (4), and the outlet of the membrane tank (4) is connected to the input end of the outlet pump (7).

10. The apparatus according to claim 6, characterized in that, The membrane tank (4) is also equipped with an aeration device or a stirring device, which is installed at the bottom of the membrane tank (4) and below the ultrafiltration membrane module (5).

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