Continuous flow disinfection reactor system and method for disinfecting water by using same

Abstract

The invention discloses a continuous flow disinfection reactor system. The continuous flow disinfection reactor system comprises a double-chamber photocatalytic reaction unit and a Fenton disinfection unit, the double-chamber photocatalytic reaction unit is composed of a photocatalytic chamber and a microorganism chamber, and a semi-permeable membrane with the molecular interception of 12000-14000 Da is arranged between the photocatalytic chamber and the microorganism chamber; the microorganism chamber is provided with a water inlet and a water outlet, water to be treated enters the microorganism chamber through the water inlet, and the water outlet is connected with the Fenton disinfection unit through a pipeline; the photocatalysis chamber is internally provided with a visible light source and is loaded with a photocatalyst; the Fenton disinfection unit is provided with a Fe < 2 + > injection device and a disinfectant fluid outlet, and is used for disinfecting the mixed water conveyed by the double-chamber photocatalytic reaction unit. The semi-permeable membrane is used for separating the photocatalysis chamber from the microorganism chamber, separation of the photocatalysis chamber and the microorganism chamber in space is achieved, synthesized H2O2 can be exclusively and effectively transferred to a Fenton reaction site for disinfection, high photocatalysis efficiency and remarkable sterilization effect are achieved, and a potential solution is provided for water pollution.

Description

Technical Field

[0001] The present invention belongs to the technical field of photocatalysis, and particularly relates to a continuous flow disinfection reactor system and a method for water disinfection using the same. Background Art

[0002] Waterborne diseases caused by pathogenic microorganisms have posed a major threat to human health and safety, especially in developing regions. It is estimated that currently 3.6 billion people globally live in water-scarce areas, and this number may increase to 5.7 billion by 2050, leading to intense competition among water users. Therefore, new water treatment technologies must be developed and water environmental sanitation adjusted to ensure the recyclability of water, which is crucial for remote areas with little or limited access to clean water. Point-of-use (POU) disinfection technologies have received increasing attention due to their high economic efficiency and convenience, and have gradually become popular water disinfection technologies in rural areas of developing countries. Advanced oxidation processes (AOPs) are relatively low-cost and easy-to-operate technologies among POU. Utilizing the inexhaustible sunlight, the photo / oxidant system is the most cost-effective combination in AOPs. Among various oxidants, hydrogen peroxide (H2O2) has the highest atomic efficiency and strong oxidizing property, which makes photo / H2O2 increasingly used in water disinfection research.

[0003] Chinese Patent Application No. CN201811013305.0 discloses a sewage treatment system based on Fenton technology and its treatment method. The treatment system includes a sand filter tank connected in sequence, which has a structure for intercepting pollutants in sewage; a Fenton reactor, where activated carbon is used as a catalyst to react with hydrogen peroxide to generate hydroxyl radicals; a reaction tank for removing excess hydrogen peroxide in the Fenton reactor; and a clear water tank for adjusting the pH value of the sewage therein. The activated carbon in this solution serves as both an adsorbent and a catalyst. On the one hand, through the adsorption effect, pollutants are enriched, reducing the content of pollutants; at the same time, the activated carbon catalyzes H2O2 to form ·OH radicals, which fully react with and degrade the pollutants, greatly improving the reaction efficiency. However, due to the low efficiency of photo / H2O2, it is usually necessary to add Fe 2+ to initiate Fenton to convert H2O2 into strongly oxidizing ·OH to achieve efficient water disinfection.

[0004] In the past decade, most studies have been dedicated to developing high-performance photocatalysts for H2O2 production, and exciting progress has been made. For example, the Chinese patent application with the application number CN202211555203.8 discloses a Fenton reaction catalyst for industrial sewage treatment, its preparation method and application, belonging to the technical field of sewage treatment. The catalyst of this invention includes pre-magnetized zero-valent iron and hydrogen peroxide. By pre-magnetizing zero-valent iron in a strong magnetic field and then adding it to wastewater in combination with hydrogen peroxide, a highly efficient catalyst is formed, which has high catalytic efficiency and good stability.

[0005] However, in addition to advanced photocatalytic materials, the effective application of photocatalytic production of H2O2 for water disinfection depends on innovative reactor designs and operating methods. The main reasons restricting reactor design are as follows: (1) In the light / self-supplied H2O2 / Fe 2+ system, microorganisms and photocatalysts are often in the same space, and the adhesion of microorganisms leads to fouling and recovery problems of the photocatalyst; (2) Photocatalysts are vulnerable to damage by adverse solvent systems in practical applications, and inorganic salts and organic substances in real water bodies will seriously interfere with the catalytic performance of photocatalysts; (3) The dependence on light is a default limitation of light-based related applications. The key to solving the above problems lies in separating the photocatalyst from microorganisms. Therefore, the present invention designs a photocatalytic reactor based on the "partition system" of the stability of H2O2. Summary of the Invention

[0006] To solve the above problems, the present invention provides a continuous-flow disinfection reactor system and a method for water disinfection using the same. The continuous-flow disinfection reactor system conducts photocatalytic reactions in the visible light wavelength range, designs a novel double-chamber photocatalytic reactor according to the "partition system", and separates the photocatalytic compartment and the microorganism compartment using a semi-permeable membrane, while enabling the photosynthetically synthesized H2O2 to be exclusively and effectively transferred to the Fenton reaction site for disinfection. The continuous-flow disinfection reactor system has high photocatalytic efficiency, remarkable bactericidal effect, and a simple and convenient synthesis method, providing a potential solution for water pollution.

[0007] The technical solution of the present invention is as follows:

[0008] One of the objectives of the present invention is to provide a continuous-flow disinfection reactor system, and the continuous-flow disinfection reactor system includes a double-chamber photocatalytic reaction unit and a Fenton disinfection unit;

[0009] Dual-chamber photocatalytic reaction unit: It is composed of a photocatalytic chamber and a microbial chamber. A semi-permeable membrane is arranged between the photocatalytic chamber and the microbial chamber; the molecular cut-off of the semi-permeable membrane is 12,000 - 14,000 Da; the microbial chamber is provided with a water inlet and a water outlet. The water to be treated enters the microbial chamber through the water inlet, and the water outlet is connected to the Fenton disinfection unit through a pipeline; a visible light source is arranged in the photocatalytic chamber and a photocatalyst is loaded;

[0010] Fenton disinfection unit: It is provided with Fe 2+ injection device and disinfected water outlet, which are used to disinfect the mixed water transported from the dual-chamber photocatalytic reaction unit.

[0011] Further, the visible light source is a 300W xenon lamp.

[0012] Further, the dosage of the photocatalyst is 5 mg.

[0013] The second object of the present invention is to provide a method for water disinfection using any one of the above continuous flow disinfection reactor systems, including the following steps:

[0014] S11: The water to be treated enters the microbial chamber of the dual-chamber photocatalytic reaction unit through the water inlet, and H2O enters the photocatalytic chamber through the semi-permeable membrane;

[0015] S12: Under the irradiation of visible light and the action of the photocatalyst, photocatalytic reaction continuously occurs in the photocatalytic chamber to generate H2O2. Due to the concentration difference effect, H2O2 orderly passes through the semi-permeable membrane and mixes with the water to be treated in the microbial chamber to obtain a mixed water containing H2O2;

[0016] S13: The mixed water containing H2O2 enters the Fenton disinfection unit through a pipeline and reacts with the injected Fe 2+ to generate highly reactive hydroxyl radicals, thereby playing a bactericidal role. The disinfected water after disinfection treatment is output through the disinfected water outlet to complete water disinfection.

[0017] Further, in step S12, the photocatalyst is a composite polyvinylpyrrolidone covalent organic framework photocatalyst, namely FCOF / PVP, which is composed of a covalent organic framework photocatalyst and polyvinylpyrrolidone through a solvothermal reaction.

[0018] Further, the preparation method of the composite polyvinylpyrrolidone covalent organic framework photocatalyst includes the following steps:

[0019] S21: Place 178 mg of 4,4',4”-(1,3,5-triazine-2,4,6-triyl)tri-aniline and 155 mg of 2,3,5,6-tetrafluoroterephthalaldehyde into a 25 mL thick-walled solvent storage bottle containing 2 mL of mesitylene and 18 mL of 1,4-dioxane. After adding 1 mL of 6 mol / L aqueous acetic acid solution, quickly freeze the sample using liquid nitrogen and degas it through three freeze-pump-thaw cycles. After thawing to room temperature, heat it in a constant temperature air blast drying oven at 120 °C for 72 h. The obtained precipitate is centrifugally washed three times with N,N-dimethylformamide, tetrahydrofuran, and n-hexane respectively, and then the wet sample is placed in a vacuum drying oven at 80 °C for 12 h to obtain FCOF;

[0020] S22: Weigh 25 mg of the FCOF obtained in step S21 and x mg of polyvinylpyrrolidone (where x ranges from 0 to 200) into a 50 mL beaker. Then add 30 mL of N,N-dimethylformamide, ultrasonicate for 15 min and then stir for 2 h to make it mix evenly. Then transfer the mixture to a 50 mL reaction kettle lined with polytetrafluoroethylene and react at 180 °C for 48 h. After the reaction is completed and cooled to room temperature, collect the solid precipitate and filter it with ultrapure water and wash it 5 times, and dry it in a vacuum at 60 °C for 12 h to obtain the composite polyvinylpyrrolidone covalent organic framework photocatalyst, namely FCOF / PVP-x.

[0021] Furthermore, in step S21, the aqueous acetic acid solution is 6 mol / L.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. A continuous flow disinfection reactor system provided by the present invention uses a semipermeable membrane to separate the photocatalytic compartment and the microbial compartment, achieving spatial separation of the catalyst and the microorganism, realizing efficient photocatalytic production of H2O2 and efficient transfer of H2O2 to the Fenton disinfection area. It retains the essential advantages of homogeneous catalysis and heterogeneous catalysis in the reaction, avoids blockage of active sites caused by microbial attachment, and extends the service life of the catalyst. At the same time, the present invention enables the photosynthetic H2O2 to be exclusively and effectively transferred to the Fenton reaction site for disinfection. This continuous flow disinfection reactor system has high photocatalytic efficiency, significant bactericidal effect, and simple and convenient synthesis method, providing a potential solution for water pollution.

[0024] 2. A method for water disinfection using a continuous flow disinfection reactor system provided by the present invention realizes efficient sterilization through a dual-chamber partition design, a photocatalytic-Fenton coupling mechanism, and continuous flow process optimization, providing an efficient, green, and scalable technical path for the field of water disinfection and having significant industrial application value.

[0025] 3. In the present invention, the photocatalyst used is a composite polyvinylpyrrolidone covalent organic framework photocatalyst, which improves the yield of H2O2 in the full wavelength band by coupling FCOF and PVP. Due to the conjugation effect between FCOF and PVP, FCOF / PVP tends to transfer more e - to the interfacial adsorbed O2 to generate ·O2 - , which is further used to generate H2O2. At the same time, the modification of PVP can improve the material's 1 O2 conversion, 1 O2 transfers energy to the surface adsorbed O2, and then is converted into H2O2. In the ultraviolet wavelength band, due to the protection of PVP, the generated H2O2 in the system will not be decomposed by ultraviolet rays into ·OH, thus further increasing the amount of H2O2 produced by the catalyst. Description of the Drawings

[0026] Figure 1 This is the X-ray powder diffraction pattern of FCOF prepared in Example 1 and FCOF / PVP-100 prepared in Example 3 in the present invention;

[0027] Figure 2 This is the Fourier transform infrared spectrum of FCOF prepared in Example 1 and FCOF / PVP-100 prepared in Example 3 in the present invention;

[0028] Figure 3 This is the effect diagram of visible light photocatalytic preparation of hydrogen peroxide under pure water conditions for FCOF prepared in Example 1 and FCOF / PVP-x prepared in Examples 1-5 in the present invention;

[0029] Figure 4 This is the schematic diagram of the partition chambers in each region of the continuous flow disinfection reactor system in the present invention;

[0030] Figure 5 This is the flow chart of water disinfection using the continuous flow disinfection reactor system in the present invention;

[0031] Figure 6 This is the schematic diagram of the change in H2O2 concentration in different regions during 10 h of light irradiation and then 2 h of darkness for FCOF / PVP-100 in the continuous flow disinfection reactor system in the present invention;

[0032] Figure 7 This is the schematic diagram of the inactivation of Escherichia coli in sterile physiological saline by adding FCOF / PVP-100 to the continuous flow disinfection reactor system in the present invention. Detailed Embodiments

[0033] The following combines preferred embodiments and refers to the attached Figure 1-7, for further illustration of the present invention, the endpoints and any values within the disclosed scope of the present invention are not limited to the exact scope or value. These scopes or values should be understood to include values close to these scopes or values; for numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein; the materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources; the experimental methods in the following examples, unless otherwise specified, are conventional methods.

[0034] Example 1

[0035] This example provides a composite polyvinylpyrrolidone covalent organic framework photocatalyst, and its preparation method includes the following steps:

[0036] S21: Put 178 mg of 4,4',4”-(1,3,5-triazine-2,4,6-triyl)triphenylamine and 155 mg of 2,3,5,6-tetrafluoroterephthalaldehyde into a 25 mL thick-walled solvent storage bottle containing 2 mL of mesitylene and 18 mL of 1,4-dioxane. After adding 1 mL of acetic acid aqueous solution (6 mol / L), quickly freeze the sample with liquid nitrogen, and degas it through three freeze-pump-thaw cycles. After thawing to room temperature, heat it in a constant temperature air blast drying oven at 120 °C for 72 h. The obtained precipitate is centrifugally washed 3 times with N,N-dimethylformamide, tetrahydrofuran, and n-hexane respectively, and then place the wet sample in a vacuum drying oven at 80 °C to dry overnight to obtain FCOF;

[0037] S22: Weigh 25 mg of the FCOF obtained in step S21 and x mg of polyvinylpyrrolidone in a 50 mL beaker, then add 30 mL of N,N-dimethylformamide, ultrasonicate for 15 min and then stir for 2 h to make it mix evenly. Then transfer the mixture to a 50 mL reaction kettle lined with polytetrafluoroethylene, and react at 180 °C for 48 h. After the reaction is completed and cooled to room temperature, collect the solid precipitate and filter it with ultrapure water and wash it 5 times, and dry it overnight in a vacuum at 60 °C to obtain the composite polyvinylpyrrolidone covalent organic framework photocatalyst, that is, FCOF / PVP-x.

[0038] In this example, x is 0, and the obtained composite polyvinylpyrrolidone covalent organic framework photocatalyst is FCOF / PVP-0.

[0039] Example 2

[0040] This example provides a composite polyvinylpyrrolidone covalent organic framework photocatalyst, which is basically the same as Example 1, except that:

[0041] In this embodiment, x is 50, and the obtained composite polyvinylpyrrolidone covalent organic framework photocatalyst is FCOF / PVP-50.

[0042] Example 3

[0043] This embodiment provides a composite polyvinylpyrrolidone covalent organic framework photocatalyst, which is basically the same as that in Example 1, except that:

[0044] In this embodiment, x is 100, and the obtained composite polyvinylpyrrolidone covalent organic framework photocatalyst is FCOF / PVP-100.

[0045] Example 4

[0046] This embodiment provides a composite polyvinylpyrrolidone covalent organic framework photocatalyst, which is basically the same as that in Example 1, except that:

[0047] In this embodiment, x is 150, and the obtained composite polyvinylpyrrolidone covalent organic framework photocatalyst is FCOF / PVP-150.

[0048] Example 5

[0049] This embodiment provides a composite polyvinylpyrrolidone covalent organic framework photocatalyst, which is basically the same as that in Example 1, except that:

[0050] In this embodiment, x is 200, and the obtained composite polyvinylpyrrolidone covalent organic framework photocatalyst is FCOF / PVP-200.

[0051] Example 6

[0052] This embodiment provides a continuous-flow disinfection reactor system, which includes a two-chamber photocatalytic reaction unit and a Fenton disinfection unit;

[0053] Two-chamber photocatalytic reaction unit: It consists of a photocatalytic chamber and a microbial chamber, and a semipermeable membrane is arranged between the photocatalytic chamber and the microbial chamber; the molecular cut-off of the semipermeable membrane is 12000-14000 Da, and only small molecules such as H2O and H2O2 are allowed to flow freely, while the photocatalyst and microorganisms cannot pass through; the microbial chamber is provided with a water inlet and a water outlet, the water to be treated enters the microbial chamber through the water inlet, and the water outlet is connected to the Fenton disinfection unit through a pipeline; a visible light source is arranged in the photocatalytic chamber and loaded with a photocatalyst;

[0054] Fenton disinfection unit: It is provided with a Fe 2+ injection device and a disinfected water outlet, which are used to disinfect the mixed water transported from the two-chamber photocatalytic reaction unit.

[0055] Example 7

[0056] This example provides a method for water disinfection using the continuous flow disinfection reactor system of Example 6, including the following steps:

[0057] S11: The water to be treated enters the microbial chamber of the double-chamber photocatalytic reaction unit through the water inlet, and H2O enters the photocatalytic chamber through the semi-permeable membrane;

[0058] S12: Under the irradiation of visible light and the action of the photocatalyst, photocatalytic reactions continuously occur in the photocatalytic chamber to generate H2O2. Due to the concentration difference effect, H2O2 orderly passes through the semi-permeable membrane and mixes with the water to be treated in the microbial chamber to obtain mixed water containing H2O2;

[0059] S13: The mixed water containing H2O2 enters the Fenton disinfection unit through a pipeline, reacts with the injected Fe 2+ to generate highly reactive hydroxyl radicals, thereby playing a bactericidal role. The disinfected water after disinfection treatment is output through the disinfected water outlet to complete water disinfection.

[0060] Evaluation of implementation effect:

[0061] Figure 1 This is the X-ray powder diffraction pattern of FCOF prepared in Example 1 of the present invention and FCOF / PVP-100 prepared in Example 3. It can be seen from Figure 1 that FCOF / PVP-100 exhibits characteristic diffraction peaks consistent with those of FCOF, indicating that the modification of amorphous PVP does not change the crystal structure of the parent material.

[0062] Figure 2 This is the Fourier transform infrared spectrum of FCOF prepared in Example 1 of the present invention and FCOF / PVP-100 prepared in Example 3. It can be seen from Figure 2 that FCOF / PVP-100 exhibits characteristic absorption peaks consistent with those of FCOF, indicating that the modification of amorphous PVP does not change the framework structure of the parent material.

[0063] Figure 3 This is the effect diagram of visible light photocatalytic preparation of hydrogen peroxide under pure water conditions for FCOF prepared in Example 1 of the present invention and FCOF / PVP-x prepared in Examples 1-5. Among them, the visible light source is a 300W xenon lamp, the dosage of the photocatalyst is 5mg, and the reaction system is 50mL of ultrapure water. It can be seen from Figure 3 that compared with the parent material FCOF, FCOF / PVP-100 obtained in Example 3 has higher hydrogen peroxide production performance, which is 1763.50 μmol / g / h.

[0064] Figure 4 It is a schematic diagram of the partition chambers in each region of the continuous-flow disinfection reactor system of Embodiment 6 of the present invention. As Figure 4 shown, the photocatalytic region is divided into partition chamber 1 (photocatalytic chamber) and partition chamber 2 (microbial chamber), and the two partition chambers are connected by a pipeline.

[0065] Figure 5 It is a flow chart of the continuous-flow disinfection reactor system of Embodiment 6 of the present invention. As Figure 5 shown, the continuous-flow disinfection reactor system includes a two-chamber photocatalytic reaction unit and a Fenton disinfection unit. The two-chamber photocatalytic reaction unit consists of a photocatalytic chamber and a microbial chamber. A semi-permeable membrane is arranged between the photocatalytic chamber and the microbial chamber to isolate microorganisms from photocatalysts. The photocatalytic chamber is responsible for the photosynthesis of H2O2, and then H2O2 passes through the semi-permeable membrane and mixes with the pathogenic microorganisms carried by the influent water in the microbial chamber; the mixed water containing H2O2 enters the Fenton disinfection area through a pipeline and reacts with the injected Fe 2+ to carry out the Fenton reaction to achieve the purpose of sterilization, and the effluent water can be used for household or irrigation.

[0066] Figure 6 It is the change of H2O2 in different regions during 10 h of light irradiation and then 2 h of darkness in the continuous-flow reactor system of Embodiment 6 of the present invention using the FCOF / PVP-100 prepared in Example 3. From Figure 6 it can be seen that after 3 h of hydraulic retention time (HRT) and 10 h of light irradiation, the concentration of H2O2 in the photocatalytic chamber continuously and stably rises and flows to the microbial chamber and the Fenton disinfection unit through the concentration difference effect.

[0067] In addition, a large amount of H2O2 remains in the photocatalytic chamber. After turning off the light for 2 h, H2O2 gradually diffuses from the photocatalytic chamber to the microbial chamber and the Fenton disinfection unit, and the Fenton reaction can still occur after adding Fe 2+ This indicates that the system has the potential for continuous sterilization under dark conditions.

[0068] Figure 7 It is a schematic diagram of the inactivation of Escherichia coli in sterile physiological saline by the FCOF / PVP-100 prepared in Example 3 in the continuous-flow disinfection reactor system of Example 6. The disinfection ability of the continuous-flow reactor system was evaluated with Escherichia coli (E. coli) at 5 log cfu / mL close to the natural environment. After 3 h of HRT, the concentration of E. coli in the microbial chamber changed little, but no E. coli was detected in the effluent water, which indicates that the inactivation effect of H2O2 on E. coli alone is not significant, and the Fenton reaction is the root cause of bacterial death. After turning off the light for 2 h, the Fenton reaction in the dark achieved the continuous inactivation of E. coli.

[0069] In order to avoid the adhesion of bacteria to the photocatalyst, the damage of adverse solvents to the photocatalyst, and to achieve the effective separation and recovery of the photocatalyst in the photocatalytic region, the present invention designs a novel double-chamber reactor. A semipermeable membrane with a molecular cut-off of 12000 - 14000 Da is placed in the middle of the double-chamber reactor to separate the two compartments. This semipermeable membrane only allows small molecules such as H2O and H2O2 to flow freely, while the photocatalyst and microorganisms cannot pass through. In the sterilization experiment, 50 mg of FCOF / PVP-100 is placed in the photocatalytic compartment. Under visible light irradiation, continuous photocatalytic reactions occur to produce H2O2. Due to the concentration difference effect, H2O2 can pass through the semipermeable membrane orderly and mix with the influent water, and then flow together to the Fenton reaction zone, continuously supplying the Fenton reaction as an oxidant. This continuous-flow disinfection reactor system has high photocatalytic efficiency, significant sterilization effect, and simple and convenient synthesis method, providing a potential solution for water pollution.

[0070] Moreover, in the present invention, the photocatalyst used is a composite polyvinylpyrrolidone covalent organic framework photocatalyst. This catalyst is obtained by coupling FCOF and PVP, thereby improving the yield of H2O2 by the catalyst in the full wavelength range. Due to the conjugation effect between FCOF and PVP, FCOF / PVP tends to transfer more e - to the interfacial adsorbed O2 to generate ·O2 - , and it is further used to generate H2O2. At the same time, after the surface modification by PVP, the long-lived photobiological species generated by FCOF transfer the energy to the surface adsorbed O2 to generate 1 O2, which then converts to H2O2. In the ultraviolet wavelength range, due to the protection of PVP, the H2O2 generated in the system will not be decomposed by ultraviolet rays into ·OH, which can further increase the amount of H2O2 produced by the catalyst.

[0071] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the inventive concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A continuous flow disinfection reactor system, characterized in that: The continuous flow disinfection reactor system includes a double-chamber photocatalytic reaction unit and a Fenton disinfection unit; Double-chamber photocatalytic reaction unit: composed of a photocatalytic chamber and a microbial chamber, a semipermeable membrane is arranged between the photocatalytic chamber and the microbial chamber; the molecular retention capacity of the semipermeable membrane is 12000-14000Da; the microbial chamber is provided with a water inlet and a water outlet, the water to be treated enters the microbial chamber through the water inlet, and the water outlet is connected to the Fenton disinfection unit through a pipeline; a visible light source is arranged in the photocatalytic chamber and loaded with a photocatalyst; Fenton disinfection unit: equipped with Fe 2+ The injection device and the disinfection water outlet are used to disinfect the mixed water delivered by the double-chamber photocatalytic reaction unit.

2. A continuous flow disinfection reactor system according to claim 1, characterized in that: The visible light source is a 300W xenon lamp.

3. A continuous flow disinfection reactor system according to claim 1, characterized in that: The amount of the photocatalyst used is 5 mg.

4. A method for water disinfection using a continuous flow disinfection reactor system according to any one of claims 1 to 3, characterized in that: The following steps are involved: S11: The water to be treated enters the microbial chamber of the dual-chamber photocatalytic reaction unit through the water inlet, and H2O enters the photocatalytic chamber through the semipermeable membrane; S12: Under the irradiation of visible light and the action of the photocatalyst, a photocatalytic reaction is continuously carried out in the photocatalytic chamber to produce H2O2. Due to the concentration difference effect, H2O2 passes through the semipermeable membrane in an orderly manner and mixes with the water to be treated in the microbial chamber to obtain mixed water containing H2O2. S13: The mixed water containing H2O2 enters the Fenton disinfection unit through a pipeline and is injected with Fe 2+ The Fenton reaction occurs to generate highly active hydroxyl free radicals, which then have a bactericidal effect. The disinfected water is output through the disinfected water outlet to complete the water disinfection.

5. A method for water disinfection using a continuous flow disinfection reactor system according to claim 4, characterized in that: In step S12, the photocatalyst is a composite polyvinyl pyrrolidone covalent organic framework photocatalyst, namely FCOF / PVP, which is formed by a covalent organic framework photocatalyst and polyvinyl pyrrolidone through a solvothermal reaction.

6. A method for water disinfection using a continuous flow disinfection reactor system according to claim 5, characterized in that: The preparation method of the composite polyvinyl pyrrolidone covalent organic framework photocatalyst comprises the following steps: S21: 178 mg of 4,4',4"-(1,3,5-triazine-2,4,6-triyl)triphenylamine and 155 mg of 2,3,5,6-tetrafluoroterephthalaldehyde were placed in a 25 mL thick-walled solvent storage bottle containing 2 mL of mesitylene and 18 mL of 1,4-dioxane. After adding 1 mL of 6 mol / L aqueous acetic acid, the sample was quickly frozen with liquid nitrogen and degassed through three freeze-pump-thaw cycles. After thawing to room temperature, it was heated in a constant temperature forced air drying oven at 120°C for 72 h. The obtained precipitate was centrifugally washed three times with N,N-dimethylformamide, tetrahydrofuran and n-hexane, respectively, and then the wet sample was placed in a vacuum drying oven at 80°C and dried for 12 h to obtain FCOF. S22: Weigh 25 mg of FCOF obtained in step S21 and x mg of polyvinyl pyrrolidone into a 50 mL beaker, where x is 0-200, and then add 30 mL of N,N-dimethylformamide. After ultrasonication for 15 min, stir for 2 h to mix it evenly. Then transfer the mixture to a 50 mL polytetrafluoroethylene-lined reactor and react at 180°C for 48 h. After the reaction is completed and cooled to room temperature, collect the solid precipitate and wash it with ultrapure water for 5 times, and vacuum dry it at 60°C for 12 h to obtain the composite polyvinyl pyrrolidone covalent organic framework photocatalyst, i.e., FCOF / PVP-x.

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