Modified optical fiber conducts multi-band ultraviolet LED light catalytic device

Abstract

A modified optical fiber transmission multi-band ultraviolet LED photocatalytic device for ship ballast water and sediment treatment, comprising a base, a submersible pump, a reactor cylinder, a multi-band ultraviolet LED light source, a modified quartz optical fiber, an optical fiber cover, an optical fiber support, a flow meter and a diaphragm valve. The modified quartz optical fiber support is installed in the reactor sleeve; the modified quartz optical fiber is inserted into the optical fiber support, and the two ends form an optical fiber bundle; the outer side of the modified quartz optical fiber cladding is coated with a Cu / N-TiO2 photocatalyst; the device utilizes the synergistic inactivation effect of optical fiber transmission multi-band ultraviolet and modified Cu / N-TiO2 photocatalyst, solves the problems of low ultraviolet light utilization efficiency, high energy consumption, mercury leakage in ultraviolet lamp and other problems existing in traditional low-pressure and medium-pressure ultraviolet mercury lamps, and realizes the saving, intensive, green and low-carbon of ultraviolet technology.

Description

TECHNICAL FIELD

[0001] The application discloses a multi-band ultraviolet LED photocatalytic device, in particular to a modified optical fiber transmission multi-band ultraviolet LED photocatalytic device for ship ballast water and sediment treatment, and belongs to the field of sewage treatment. BACKGROUND

[0002] During the operation of a ship, part of the foreign aquatic organisms and phytoplankton resting spores, pathogens, bacteria in the ballast water, together with solid particles in the water, accumulate at the bottom of the ballast tank, forming ballast water sediments. Some of the harmful organisms can resist harsh environments and can survive in the sediments for at least 6 years. When the environment is suitable, they will germinate again, forming harmful red tides and other marine disasters. Many studies have shown that ship ballast water and sediments are one of the important sources of harmful red tides and other marine disasters. At present, there is still a vacancy in the industry standard for the discharge and treatment of ballast water sediments, and there is a lack of basic data. The research on the killing and control technology of harmful organisms in ballast water and sediments is still at the laboratory pilot stage, and there are still many loopholes and problems, which may cause serious environmental pollution and biological safety hazards.

[0003] Due to the fact that the ballast water containing sediments is mixed with a large amount of solid particles such as silt, the hydrological conditions are complex, resulting in the problems of low unit inactivation rate and high energy consumption in the biological inactivation process of the existing ultraviolet inactivation system. This is because the ultraviolet light source of the existing ultraviolet inactivation system is relatively traditional, and the inactivation efficiency is limited. It is of great environmental protection significance to develop a high-efficiency and low-energy consumption ballast water and sediment treatment device.

[0004] CN101541685A discloses an apparatus for treating ballast water with ultraviolet radiation and catalyst. The apparatus includes a housing having a JLV radiation device, and a catalyst including a plurality of turbulence and mixing generating devices, the catalyst being disposed in the housing, the catalyst having one or more turbulence and mixing generating devices selected from the group consisting of perforations, holes, perforations, structured compression, corrugations, and the like.

[0005] CN201512425U discloses a kind of ultraviolet light catalytic ship ballast water treatment reactor, and the reactor includes reaction unit, reaction wall body, fixing device and valve;Reaction unit is composed of ultraviolet lamp, protection tube and porous photocatalyst;Ultraviolet lamp is placed in the center of protection tube, and porous photocatalyst loaded on carrier is closely attached to the outer wall of protection tube and fixed on both sides thereof, one end of reaction unit is fixed in the bottom of reaction cavity through fixing device, the other end including power supply interface end of ultraviolet lamp is installed on the upper end cover of reaction cavity using sealing structure, and valve is installed at water inlet and water outlet of reaction cavity through adapter.

[0006] CN204939024U discloses a kind of ultraviolet reaction device, including reaction container, and install in reaction container multiple ultraviolet fluorescent tube, reactor is fixed with left and right one lamp holder, two segments of each fluorescent tube are fixed on two lamp holders, and ultraviolet fluorescent tube is arranged into concentric double-ring fluorescent tube array;Fluorescent tube array is sleeved with a cleaning tray that can slide left and right, cleaning tray is equipped with multiple cleaning seats, cleaning seat has cleaning hole, and the hole wall of cleaning hole has soft cleaning pad.The reaction device is particularly suitable for treating ship ballast water. SUMMARY

[0007] The present application is directed to the problem of low UV light utilization efficiency and high energy consumption of existing UV inactivation systems, and proposes a modified optical fiber transmission multi-band UV LED photocatalytic device for ship ballast water and sediment treatment.The present application solves the problems of low UV light utilization efficiency, high energy consumption and mercury leakage in UV lamps in traditional low-pressure and medium-pressure UV mercury lamps, and realizes high utilization and green low carbon of UV technology.

[0008] In one aspect of the present application, a modified optical fiber transmission multi-band UV LED photocatalytic device for ship ballast water and sediment treatment is disclosed, comprising: a submersible pump, a reactor cylinder, a multi-band UV LED light source, a modified quartz optical fiber, an optical fiber cover, an optical fiber support, a flow meter and a diaphragm valve; the modified quartz optical fiber support is installed in the reactor sleeve; the modified quartz optical fiber is inserted into the optical fiber support, and the two ends form an optical fiber bundle; the outer side of the modified quartz optical fiber cladding is coated with Cu / N-TiO2 photocatalyst; the multi-band UV LED light is scattered into the reactor cylinder after being transmitted through the modified quartz optical fiber.

[0009] The Cu / N-TiO2 photocatalyst is loaded with copper and nitrogen on a TiO2 carrier, wherein Cu 2+ The molar ratio of Cu to TiO2 photocatalyst TiO2 is 0.5-5%, preferably 1-2%; N 3- The molar ratio of N to TiO2 is 1-10%, more preferably 2-5%.

[0010] The preparation method of Cu / N-TiO2 photocatalyst is as follows:

[0011] (1) slowly drop tetrabutyl titanate into anhydrous ethanol at 20-50°C, continuously stir for 10-60 min to obtain a mixed solution A;

[0012] (2) mix anhydrous ethanol, deionized water and glacial acetic acid to obtain a solvent mixture, dissolve copper nitrate and urea in the solvent mixture, adjust the pH value to 1-3, and obtain solution B;

[0013] (3) add solution A dropwise to solution B and continuously stir, after the addition of solution B is completed, fully react for 1-3 h to obtain a precipitate, and wash the precipitate;

[0014] (4) drying and grinding the precipitate obtained in step (3), and calcining the obtained powder, and then keeping the calcined product at temperature for 6-24 hours to obtain the Cu / N-TiO2 photocatalyst.

[0015] The volume ratio of the anhydrous ethanol and tetrabutyl titanate in step (1) is 3-10:1, and more preferably 5-6:1.

[0016] In step (2), the volume ratio of the anhydrous ethanol, deionized water and glacial acetic acid is 3-15:0.2-5:0.5-5; more preferably 5-10:0.5-2:1-2; the molar ratio of the copper nitrate, urea and tetrabutyl titanate is 1-2:1-2:70-120; and in step (2), an inorganic acid is used to adjust the pH value, and preferably hydrochloric acid or nitric acid is used.

[0017] In step (3), the volume ratio of solution A and solution B is 1-5:1, and more preferably 1.5-3:1.

[0018] In step (4), the drying temperature is 70-100°C, and more preferably 80-90°C; and the calcining temperature is 300-800°C, and more preferably 450-550°C.

[0019] The Cu / N-TiO2 photocatalyst particles are fixed on the surface of the optical fiber in a coating manner, and a conventional adhesive in the art is used for coating; the particle size of the Cu / N-TiO2 photocatalyst particles is 1-200 nm, and more preferably 10-50 nm.

[0020] The multi-band ultraviolet LED light source includes a short-wave ultraviolet LED light source and a long-wave ultraviolet LED light source, wherein the wavelength of the short-wave ultraviolet LED light source is 200-275 nm, and the wavelength of the long-wave ultraviolet LED light source is 320-400 nm; preferably, the wavelength of the short-wave ultraviolet LED light source is 230-260 nm, and the wavelength of the long-wave ultraviolet LED light source is 340-380 nm; in order to fully exert the advantages and make up for the disadvantages of different wavelengths of ultraviolet light in photocatalysis and biological inactivation, and further improve the biological inactivation efficiency.

[0021] Preferably, the system includes two groups of modified quartz optical fibers, one group of modified quartz optical fibers is parallel to the water flow direction and transmits long-wave ultraviolet LED light; and the other group of modified quartz optical fibers is perpendicular to the water flow direction and transmits short-wave ultraviolet LED light.

[0022] The diameter of the modified quartz optical fiber is 0.18-0.20 mm, the quartz optical fiber comprises a core, a cladding wrapped outside the core, and a Cu / N-TiO2 coating wrapped outside the cladding, the thickness of the Cu / N-TiO2 coating is 0.06-0.08 mm; the thickness of the cladding is 0.01-0.05 mm; the diameter of the core is 0.08-0.12 mm; and the coating improves the side light emitting capability of the quartz optical fiber. The cladding material is fluorine-doped quartz, wherein the doping amount of fluorine is 0.1-10 wt%.

[0023] Preferably, the system comprises two groups of optical fibers, one group of modified quartz optical fibers is parallel to the water flow direction and transmits long-wave ultraviolet LED light, and the other group of modified quartz optical fibers is perpendicular to the water flow direction and transmits short-wave ultraviolet LED light; the quantity ratio of the two groups of modified quartz optical fibers is 3:7-7:3; preferably 2:3-3:2.

[0024] The arrangement density of the optical fibers is 0.1-2 roots / cm 3 ; preferably 0.3-0.7, more preferably 0.4-0.6 roots / cm 3 .

[0025] The inactivation effect of microorganisms in the ballast water and sediments is reflected by the logarithmic inactivation rate. The formula of the logarithmic inactivation rate is:

[0026]

[0027] In the formula, η is the logarithmic inactivation rate, N0 is the number of microorganisms in the original solution before inactivation, and N t is the number of microorganisms in the water sample after inactivation.

[0028] The beneficial technical effects of the present application are as follows: after the multi-band ultraviolet LED light is transmitted through the modified quartz optical fiber, it is scattered into the reactor cylinder, and at the same time, it produces a synergistic inactivation effect with the modified Cu / N-TiO2 photocatalyst. Compared with the traditional ballast water and sediment inactivation method, the present application combines the modified quartz optical fiber with the multi-band ultraviolet LED light source, utilizes the good bending performance and strong side light emitting capability of the modified optical fiber, reasonably arranges the modified quartz optical fiber inside the reactor, transmits the multi-band ultraviolet LED light through the modified optical fiber, which not only makes the ultraviolet intensity distribution uniform in the reactor, but also reduces the number of ultraviolet lamp tubes, reduces energy consumption, and improves the ultraviolet inactivation efficiency. At the same time, by utilizing the synergistic inactivation effect of the multi-band ultraviolet and the modified Cu / N-TiO2 photocatalyst, the advantages of different wavelengths of ultraviolet light in photocatalysis and biological inactivation can be fully utilized and the disadvantages can be made up, and the biological inactivation efficiency is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structure diagram of a modified optical fiber transmission multi-band ultraviolet LED photocatalytic device.

[0030] Figure 2 is a schematic diagram of a fiber support;

[0031] Figure 3 is the inactivation effect of Example 1 and Comparative Examples 1-5 on algae;

[0032] Figure 4 is the inactivation effect of Example 1 and Comparative Examples 1-5 on E. coli;

[0033] Figure 5 is the inactivation effect of Example 1 and Comparative Examples 1-5 on Enterococcus;

[0034] Figure 6 is the inactivation effect of Example 1 on algae under different turbidity conditions;

[0035] Figure 7 is the inactivation effect of Example 1 on E. coli under different turbidity conditions;

[0036] Figure 8 is the inactivation effect of Example 1 on Enterococcus under different turbidity conditions;

[0037] Wherein: 1, long-wave ultraviolet LED light source; 2, short-wave ultraviolet LED light source; 3, optical fiber cover; 4, reactor cylinder;

[0038] 5, submersible pump; 6, optical fiber bundle; 7, modified quartz optical fiber; 8, diaphragm valve; 9, flow meter; 10, optical fiber support. DETAILED DESCRIPTION

[0039] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the application will be further described in detail below with reference to the drawings and specific embodiments.

[0040] The preparation method of the Cu / N-TiO2 photocatalyst is as follows:

[0041] (1) 18 mL of tetrabutyl titanate was slowly added to 84 mL of anhydrous ethanol, and a mixed solution A was obtained after stirring at 30°C for 30 min;

[0042] (2) 42 mL of anhydrous ethanol, 6 mL of deionized water and 12 mL of glacial acetic acid were mixed and stirred to obtain a solvent mixture, copper nitrate and urea were dissolved in the solvent mixture, and the pH value was adjusted to 2 to obtain solution B;

[0043] (3) Solution A was added dropwise to solution B and continuously stirred, and after the addition of solution B was completed, the precipitation was obtained after fully reacting for 2 h, and the precipitation was washed;

[0044] (4) The precipitate obtained in step (3) is dried at 80°C, ground, and the obtained powder is calcined at 400-600°C for 2h, and after the calcination is completed, the Cu / N-TiO2 photocatalyst is obtained after 12h of heat preservation.

[0045] The Cu / N-TiO2 photocatalyst has a Cu 2+ molar ratio of 0.5-3:100 with respect to TiO2; N 3- molar ratio of 2-5:100 with respect to TiO2.

[0046] Example 1

[0047] A ballast water and sediment treatment device with sterilization and inactivation effects, characterized by comprising: a submersible pump, a reactor cylinder, multi-band ultraviolet LED light sources, modified quartz optical fibers, an optical fiber support, a flow meter, and a diaphragm valve. The multi-band ultraviolet LED light sources are two short-wave ultraviolet (UVC) light sources with a wavelength of 254 nm and a power of 12w, and two long-wave ultraviolet (UVA) light sources with a wavelength of 365 nm and a power of 12w. The modified quartz optical fibers have a Cu / N-TiO2 coating, and the thickness of the coating is 10μm.

[0048] During system operation, the ballast water containing sediments enters the reactor cylinder through the submersible pump, diaphragm valve, and flow meter. The modified quartz optical fibers with a density of 0.4-0.6 roots / cm 2 are arranged in parallel and perpendicular directions along the water flow in the reactor to conduct the multi-band ultraviolet LED light sources (long-wave ultraviolet LED and short-wave ultraviolet LED) on both sides of the reactor. The modified quartz optical fibers have a Cu / N-TiO2 coating on the outside of the cladding to achieve synergistic inactivation of harmful organisms. The modified quartz optical fibers, multi-band ultraviolet LED light sources, and modified Cu / N-TiO2 photocatalyst are combined to build a modified optical fiber-conducted multi-band ultraviolet LED photocatalytic system, solving the problems of low ultraviolet light utilization efficiency and high energy consumption of traditional low-pressure and medium-pressure ultraviolet mercury lamps.

[0049] In the embodiment: the outer wall of the reactor cylinder needs to be treated to prevent ultraviolet light from leaking out and causing harm to people, while reducing the loss of ultraviolet radiation intensity; the ultraviolet LED light source is a short-wave ultraviolet (UVC) light source with a wavelength of 254 nm and a long-wave ultraviolet (UVA) light source with a wavelength of 365 nm, UVC can destroy the genetic material in the cells of microorganisms to achieve biological inactivation, but UVC has weak penetration ability, and the ballast water containing sediments can have a great impact on its inactivation effect, while UVA has strong penetration ability in water and better catalytic ability than UVC, which can produce more active substances to achieve biological inactivation, but UVA itself has weak sterilization and inactivation ability, therefore the combination of multiple bands of ultraviolet light has a certain synergistic effect; the modified quartz optical fiber surface is attached with a Cu / N-TiO2 coating layer, which not only improves the side light emitting ability of the optical fiber, but also can be excited by multiple band ultraviolet light to produce photocatalytic ability, enhancing the biological inactivation effect; the two groups of modified quartz optical fibers are installed on the optical fiber support and flexibly arranged in the reactor, so that the ultraviolet intensity distribution in the reactor is uniform, eliminating the sterilization blind area and improving the ultraviolet inactivation efficiency.

[0050] Comparative Example 1:

[0051] The same ship ballast water and sediment treatment ultraviolet inactivation device operation steps in Example 1 are used, the difference is that the ultraviolet light source is a group of 12w UVC light source, and the optical fiber has no Cu / N-TiO2 coating layer, and the optical fiber is perpendicular to the water flow direction.

[0052] Comparative Example 2:

[0053] The same ship ballast water and sediment treatment ultraviolet inactivation device operation steps in Example 1 are used, the difference is that the ultraviolet light source is a group of 12w UVC light source and a group of 12w UVA light source, and the optical fiber has no Cu / N-TiO2 coating layer, the optical fiber connected with the UVC light source is perpendicular to the water flow direction, and the optical fiber connected with the UVA light source is parallel to the water flow direction.

[0054] Comparative Example 3:

[0055] The same ship ballast water and sediment treatment ultraviolet inactivation device operation steps in Example 1 are used, the difference is that the ultraviolet light source is a group of 25w UVC light source, and the optical fiber has no Cu / N-TiO2 coating layer, and the optical fiber is perpendicular to the water flow direction.

[0056] Comparative Example 4:

[0057] The same ship ballast water and sediment treatment ultraviolet inactivation device operation steps in Example 1 are used, the difference is that the ultraviolet light source is a group of 12w UVC light source, and the optical fiber has a Cu / N-TiO2 coating layer, and the optical fiber direction is perpendicular to the water flow direction.

[0058] Comparative Example 5:

[0059] The same ship ballast water and sediment treatment UV inactivation device operation steps in example 1, the difference is that the UV light source is a set of 25w UVC light source, and the optical fiber has Cu / N-TiO2 coating, the direction of the optical fiber is perpendicular to the direction of water flow.

[0060] The different UV light intensity and the effect of microbial inactivation before and after the modification of optical fiber were compared:

[0061] The inactivation effect of microorganisms in ballast water and sediment was reflected by the logarithmic inactivation rate. The formula of logarithmic inactivation rate was:

[0062]

[0063] In the formula: η- is the logarithmic inactivation rate, N0- the number of microorganisms in the original solution before inactivation, N t - the number of microorganisms in the water sample after inactivation.

[0064] In the experiment of inactivating microalgae, E. coli and Enterococcus by modified optical fiber transmitting multi-band UV LED light catalysis, the initial concentrations of microalgae, E. coli and Enterococcus were 10 6 Cells / L, 10 6 CFU / L and 10 6 CFU / L, respectively, and the flow rates were 720 L / h, 360 L / h, 240 L / h and 180 L / h, respectively, corresponding to the hydraulic retention time of 15 s, 30 s, 45 s and 60 s, respectively. The number of living organisms before and after inactivation of microalgae and bacteria was detected by staining microscopy and plate counting method, and the inactivation rate was calculated. The results are shown in Figure 3

[0065] Figure 3 , Figure 4 , Figure 5 ​​It can be seen that the inactivation effect trends of the modified optical fiber conducting multi-band ultraviolet LED light catalysis on microalgae, E. coli and enterococci are consistent, and all have good inactivation effect. Among them, in the case that the optical fiber and the ultraviolet wavelength are the same, the inactivation rate of Comparative Example 3 is higher than that of Comparative Example 1, and the inactivation rate of Comparative Example 5 is higher than that of Comparative Example 4, which indicates that the increase of ultraviolet intensity can improve the biological inactivation efficiency of the modified optical fiber conducting multi-band ultraviolet LED light catalysis device; in the case that the optical fiber and the ultraviolet intensity are similar, the inactivation rate of Comparative Example 2 is higher than that of Comparative Example 3, and the inactivation rate of Example 1 is higher than that of Comparative Example 5, which indicates that the combined use of multi-band ultraviolet has obvious synergistic effect, and can improve the biological inactivation efficiency, and the multi-band combined use is stronger than the inactivation performance of the same total intensity ultraviolet light; in the case that the ultraviolet wavelength and the ultraviolet intensity are similar, the inactivation rate of Comparative Example 4 is higher than that of Comparative Example 1, the inactivation rate of Example 1 is higher than that of Comparative Example 2, and the inactivation rate of Comparative Example 5 is higher than that of Comparative Example 3, which indicates that after the quartz optical fiber is modified, the light emitting capacity of the optical fiber is improved, and the biological inactivation efficiency is also enhanced.

[0066] In the six groups of tests, the inactivation object is microalgae, E. coli or enterococci, and the inactivation rate of Example 1 is the highest. The above experimental results show that the modified quartz optical fiber is reasonably arranged inside the reactor, and multi-band ultraviolet LED light is transmitted through the modified optical fiber, which not only makes the ultraviolet intensity distribution uniform in the reactor, but also reduces the number of ultraviolet lamp tubes, reduces energy consumption, and improves the ultraviolet inactivation efficiency. At the same time, the synergistic inactivation effect of multi-band ultraviolet and modified Cu / N-TiO2 photocatalyst can fully exert the advantages of different wavelength ultraviolet light in photocatalysis and biological inactivation and make up for their respective disadvantages, and further improve the biological inactivation efficiency.

[0067] The penetration of ultraviolet radiation is greatly affected by the suspended matter in water, therefore, the arrangement of the optical fiber is also improved in the application, so as to reduce the deterioration of the microbial inactivation performance caused by turbid water.

[0068] The device includes a group of 12w UVC light sources and a group of 12w UVA light sources, and the optical fiber has a Cu / N-TiO2 coating, and the initial concentrations of microalgae, E. coli and enterococci are 10 6 cells / L, 10 6 CFU / L and 10 6 CFU / L respectively, the flow rates are 720L / h, 360L / h, 240L / h and 180L / h respectively, the hydraulic retention times are 15s, 30s, 45s and 60s respectively, and the turbidities are 0, 25, 50 and 75 NTU respectively.

[0069] Figure 6 、 Figure 7 、 Figure 8The effect of turbidity on the inactivation efficiency of the modified optical fiber conducting multi-band UV LED photocatalytic device was studied. The inactivation efficiency of microalgae, E. coli and Enterococcus by the modified optical fiber conducting multi-band UV LED photocatalytic device was consistent. However, with the increase of turbidity, the inactivation rate of microorganisms by the device decreased slightly, indicating that the increase of turbidity had a certain influence on the inactivation efficiency of the reaction system. However, with the extension of hydraulic retention time, the change of inactivation rate of microorganisms by the modified optical fiber conducting multi-band UV LED photocatalytic device under different turbidity was not significant. Under high turbidity (75 NTU), compared with 0 turbidity, the inactivation rate of microalgae, E. coli and Enterococcus decreased by 0.33 log, 0.72 log and 0.68 log, respectively, which still remained at a high level. The reason was that the modified optical fiber was evenly distributed in the reactor, which made the propagation distance of UV light short, thereby reducing the influence of turbidity on the inactivation efficiency. Therefore, the modified optical fiber conducting multi-band UV LED photocatalytic device is expected to achieve efficient inactivation of harmful organisms under complex water quality conditions.

Claims

1. A modified fiber-optic-guided multi-band ultraviolet LED photocatalytic device for treating ship ballast water and sediments, comprising: Submersible pumps, reactor bodies, multi-band ultraviolet LED light sources, modified quartz optical fibers, fiber optic covers, fiber optic supports, flow meters, and diaphragm valves; The fiber optic support is installed inside the reactor cylinder; the modified silica fiber is inserted into the fiber optic support, and the two ends form a fiber bundle; the outer cladding of the modified silica fiber is coated with Cu / N-TiO2 photocatalyst; multi-band ultraviolet LED light is conducted through the modified silica fiber and then scattered into the reactor cylinder; ballast water containing sediment enters the reactor cylinder through a submersible pump, diaphragm valve, and flow meter. The Cu / N-TiO2 photocatalyst is obtained by supporting copper and nitrogen on a TiO2 support, wherein Cu 2+ The molar ratio with TiO2 is 0.5-5%; N 3- The molar ratio with TiO2 is 1-10%; The multi-band ultraviolet LED light source includes a short-wave ultraviolet LED light source and a long-wave ultraviolet LED light source, wherein the wavelength of the short-wave ultraviolet LED light is 200~275nm and the wavelength of the long-wave ultraviolet LED light is 320~400nm. The reactor cylinder is equipped with two sets of modified quartz optical fibers. One set of modified quartz optical fibers is parallel to the water flow direction and transmits long-wave ultraviolet LED light; the other set of modified quartz optical fibers is perpendicular to the water flow direction and transmits short-wave ultraviolet LED light.

2. The photocatalytic device as described in claim 1, characterized in that, Cu 2+ The molar ratio with TiO2 is 1-2%; N 3- The molar ratio with TiO2 is 2-5%.

3. The photocatalytic device as described in claim 1, characterized in that, The wavelength of short-wave ultraviolet LED light is 230~260nm, and the wavelength of long-wave ultraviolet LED light is 340~380nm.

4. The photocatalytic device as described in claim 1, characterized in that, The modified silica optical fiber includes a core, a cladding layer surrounding the core, and a Cu / N-TiO2 coating surrounding the cladding layer. The thickness of the Cu / N-TiO2 coating is 0.06-0.08 mm; the thickness of the cladding layer is 0.01-0.05 mm; the diameter of the core is 0.08-0.12 mm; and the cladding material is fluorine-doped silica, wherein the fluorine doping amount is 0.1-10 wt%.

5. The photocatalytic device as described in claim 1, characterized in that, The ratio of modified silica fiber for transmitting long-wavelength ultraviolet LED light to modified silica fiber for transmitting short-wavelength ultraviolet LED light is 3:7-7:

3.

6. The photocatalytic device as described in claim 5, characterized in that, The ratio of modified silica fiber for transmitting long-wavelength ultraviolet LED light to modified silica fiber for transmitting short-wavelength ultraviolet LED light is 2:3-3:

2.

7. The photocatalytic device as described in claim 1, characterized in that, The modified silica optical fiber has a packing density of 0.1~2 fibers / cm². 3 .

8. The photocatalytic device as described in claim 7, characterized in that, The modified silica optical fiber has an array density of 0.3-0.7 fibers / cm². 3 .

9. The photocatalytic device as described in claim 8, characterized in that, The modified silica optical fiber has a packing density of 0.4-0.6 fibers / cm². 3 .

10. The photocatalytic device as described in claim 1, characterized in that, The preparation method of Cu / N-TiO2 photocatalyst is as follows: (1) Tetrabutyl titanate was slowly added dropwise to anhydrous ethanol at 20-50℃ and stirred continuously for 10-60 min to obtain mixed solution A; (2) After mixing and stirring anhydrous ethanol, deionized water and glacial acetic acid, a solvent mixture is obtained. Copper nitrate and urea are dissolved in the solvent mixture, and the pH value is adjusted to 1-3 to obtain solution B. (3) Add solution A dropwise to solution B while stirring continuously. After solution B has been added, allow it to react for 1-3 hours to obtain a precipitate. Wash the precipitate. (4) The precipitate obtained in step (3) is dried and ground, and the powder is calcined. After calcination, the powder is kept warm for 6-24 hours to obtain Cu / N-TiO2 photocatalyst.

11. The photocatalytic device as described in claim 10, characterized in that, The volume ratio of anhydrous ethanol and tetrabutyl titanate in step (1) is 3-10:1; The volume ratio of anhydrous ethanol, deionized water, and glacial acetic acid in step (2) is 3-15:0.2-5:0.5-5; the molar ratio of copper nitrate, urea, and tetrabutyl titanate is 1-2:1-2:70-120; and inorganic acids are used to adjust the pH value in step (2). In step (3), the volume ratio of solution A to solution B is 1-5:1; The drying temperature in step (4) is 70-100℃; the calcination temperature is 300-800℃. Cu / N-TiO2 photocatalyst particles are fixed on the outer surface of the cladding of a modified quartz optical fiber by coating; the particle size of the Cu / N-TiO2 photocatalyst particles is 1-200 nm.

12. The photocatalytic device as described in claim 11, characterized in that, In step (3), the volume ratio of solution A to solution B is 1.5-3:1; The drying temperature in step (4) is 80-90℃; the calcination temperature is 450-550℃. The Cu / N-TiO2 photocatalyst particles have a particle size of 10-50 nm.

13. Application of the apparatus as described in any one of claims 1-12 for the treatment of ship ballast water and sediments.

Images