KR101855571B1 - apparatus for removing blue algae using UV LEDs - Google Patents

Abstract

A greenhouse removing apparatus is disclosed. The algal remover comprises: an underwater structure forming at least one channel in the channel; And a plurality of UV LEDs for irradiating the channel with UV light so as to inactivate the algae cells present in the water flowing through the channel, wherein the underwater structure comprises an upper UV transmitting window and a lower UV transmitting window Wherein the plurality of UV LEDs comprises top UV LEDs that are two-dimensionally arrayed below the top UV transmission window to direct UV light into the flow path through the top UV transmission window, And lower UV LEDs arranged two-dimensionally on top of the lower UV transmission window to emit UV light into the flow path through the lower UV transmission window.

Description

[0001] The present invention relates to an apparatus for removing blue algae using UV LEDs,

More particularly, the present invention relates to an apparatus for removing green algae from water such as rivers, reservoirs, dams, or coasts, and more particularly, Thereby preventing or eliminating the occurrence of a green tide.

When the surface of the water is covered with green algae, the sunlight entering the water is cut off, thereby reducing the amount of dissolved oxygen in the water without further inflow of oxygen. Decreasing the amount of dissolved oxygen in water will cause aquatic organisms to die, which causes many problems in terms of social, economic and environmental aspects. Much research has been carried out to remove and inhibit algal blooms to prevent serious harm to the algae. For example, green algae removal methods include loess spraying, depth-width technique, and dissolved oxygen increase. However, the Horticultural Spray method has a problem of excessive input cost and a disturbance problem of the lake bottom ecosystem, and the deep-widening technique and the dissolved oxygen increase method are not effective in the rapidly eutrophicated waters. As an alternative to this, ultrasonic kerosene removal method and ozone sterilization method have been proposed, but they still show many limitations.

In recent years, attempts have been made to use ultraviolet radiation (UV) to suppress and eliminate the occurrence of green algae. UV has high penetration and mortality rates for certain aquatic organisms and can inhibit the growth of aquatic organisms in terms of morphology, photosynthesis, nutrition, or other physiology when irradiated to aquatic organisms. Low growth and low energy levels are observed in algae and plankton after UV treatment. Conventionally, a technique has been proposed in which a large UV lamp is installed long in an elongated drum and then the drum is partially immersed in water to remove the greenhouse. In this case, the large UV lamp includes a large quartz or glass sealing tube filled with an inert gas and having a pair of electrodes. When a high voltage is applied to the electrode, the gas is ionized to generate UV.

However, the prior art has a problem that a large UV lamp installed long in the middle of the drum is not economical, and that the capacity of the UV lamp to remove the green alga can be reduced with respect to the water flowing in the drum, resulting in inefficiency. In addition, the prior art has a problem that the factor that can reduce the distance from the inner circumferential surface of the drum to the large UV lamp is limited by the inner diameter of the drum and the size of the UV lamp. In addition, the prior art has a disadvantage in that the utilization of UV lamps, which are vulnerable to impacts, limits the use of water in waters where there are many reefs and obstacles due to the use of UV lamps.

Korean Patent No. 10-1372685 Korean Patent Publication No. 10-215-0125746

Theories and Applications of Chem. Eng., 2002, Vol. 8, No. 1. Decomposition of Microcystin-RR with immobilized TiO2 photocatalyst. Park Hye Hye, Dong Geun Lee. Department of Environmental Conservation, Gyeongsang National University

An object of the present invention is to provide a greenhouse removing apparatus which forms one or more flow paths in water and treats water flowing through the flow path with a plurality of UV LEDs to suppress / remove the occurrence of green tide.

According to an aspect of the present invention, there is provided a greenhouse removing apparatus using UV LED, comprising: an underwater structure forming at least one flow path in water; And a plurality of UV LEDs for irradiating the channel with UV light so as to inactivate algae cells present in the water flowing through the channel.

According to one embodiment, the underwater structure comprises a bidirectional UV transmission panel having an upper UV transmission window and a lower UV transmission window, wherein the plurality of UV LEDs are arranged to emit UV light through the upper UV transmission window Upper UV LEDs are arranged two-dimensionally on the lower portion of the upper UV transmission window and lower UV LEDs are arranged on the upper portion of the lower UV transmission window to irradiate UV light into the channel through the lower UV transmission window do.

According to one embodiment, the underwater structure includes at least two bidirectional UV transmission panels parallel to each other, and the at least one flow passage includes a flow path formed between two neighboring bidirectional UV transmission panels.

According to one embodiment, the underwater structure includes a buoyancy generating block that generates buoyancy in a state partially submerged in water, and the flow path includes a flow path formed between the bottom surface of the buoyancy generating block and the bi-directional permeation panel.

According to one embodiment, the algae removing device further comprises a surface cleaning unit for wiping the surface of the upper UV transmission window or the lower UV transmission window.

According to one embodiment, the surface cleaning unit includes a wiper contacting the surface, and a wiper driving unit that linearly or rotationally moves the wiper in contact with the surface.

According to an embodiment of the present invention, the green-light removing apparatus further includes a solar cell panel connected to the underwater structure in a state exposed on the water surface, and the plurality of UV LEDs operate by receiving power generated by the solar cell panel .

According to an embodiment of the present invention, the greenhouse removing apparatus further includes a pollution degree measuring sensor for measuring pollution degree in the water, and a controller for controlling the plurality of UV LEDs based on the pollution degree information measured by the pollution degree measuring sensor.

According to one embodiment, the plurality of UV LEDs comprises UV A LEDs having a UV A wavelength band, UV B LEDs having a UV B wavelength band, and UV C LEDs having a UV C wavelength band, And the pollution degree measuring sensor selectively controls the UV A LEDs, the UV B LEDs and the UV C LEDs according to the degree of contamination measured.

According to one embodiment, the greenhouse removing apparatus further includes a connecting member for connecting the plurality of bidirectional UV transmitting panels in a vertically spaced state, and a connection link formed for connection with the greenhouse removing apparatus or connection with the tugboat do.

According to one embodiment, the underwater structure includes a plurality of UV transmissive bend tubes forming a plurality of flow paths in the periphery, the plurality of UV LEDs are arrayed in a curved pattern in the UV transmissive bend tube, the UV transmissive And the UV light is applied to the passage formed around the UV-permeable bending tube in the bending tube.

According to one embodiment, the algal remover includes TiO2 in the path where UV light is emitted from the plurality of UV LEDs.

According to the present invention, there is provided a greenhouse removing apparatus for forming one or more flow paths in water while treating water flowing through the flow paths with a plurality of UV LEDs to suppress / remove the occurrence of green tide. Other advantages of the present invention will be understood from the following description of the embodiments.

FIG. 1 is a schematic view for explaining an embodiment of a greenhouse removing apparatus according to the present invention,
Fig. 2 is an enlarged view of the area "A" in Fig. 1,
FIG. 3 is an exploded view showing a bidirectional UV transmission panel and UV LEDs of the greenhouse removing apparatus shown in FIGS. 1 and 2. FIG.
FIG. 4 is a view for explaining an operation of a greenhouse removing apparatus according to an embodiment,
FIG. 5 is a view for explaining a method of moving a greeneye removing device according to the present invention in a specific water area,
FIG. 6 is a view for explaining a method in which a plurality of greenhouse removing apparatuses are connected and used.
7 is a plan view for explaining a surface cleaning unit for cleaning the UV transmitting window surface of the bi-directional UV transmitting panel of the greening device,
8 is a sectional view for explaining the surface cleaning unit shown in Fig. 7,
FIG. 9 is a configuration diagram for explaining another embodiment of the greenhouse removing apparatus according to the present invention,
FIG. 10 is a view showing a greenhouse removing apparatus in the direction of FIG. 9; FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings and the description thereof are intended to aid those of ordinary skill in the art in understanding the present invention. Accordingly, the drawings and description are not to be construed as limiting the scope of the invention.

1 to 3, the greenhouse removing apparatus 1 according to the present embodiment is an apparatus used for suppressing and removing the green tide of the water in a partially submerged state in a specific water area, (100) for forming first, second, third and fourth flow paths (f1, f2, f3 and f4), and a second flow path 3 and the fourth flow paths f1, f2, f3, and f4 with UV light.

The underwater structure 100 includes first, second, and third bidirectional UV transmission panels 110a, 110b, and 110c and a buoyancy generation block 120. The buoyancy generating block 120 is disposed at the uppermost position, and a part of the buoyancy generating block 120 is submerged in the water and a part of the buoyancy generating block 120 is exposed above the water surface. Also, the first, second, and third bidirectional UV transmission panels 110a, 110b, and 110c are arranged vertically below and spaced apart from each other below the buoyancy generation block 120. The first flow path f1 is formed between the bottom surface of the buoyancy generating block 120 and the first bidirectional UV transmitting panel 110a and the first bidirectional UV transmitting panel 110a and the second bidirectional UV transmitting & The second flow path f2 is formed between the first and second bidirectional UV transmitting panels 110b and 110b and the third flow path f3 is formed between the second bidirectional UV transmitting panel 110b and the third bidirectional UV transmitting panel 110c, A fourth flow path f4 is formed immediately below the third bidirectional UV transmitting panel 110c.

The bidirectional UV transmitting panel 110a, 110b or 110c is substantially rectangular and has upper and lower UV transmitting windows 112U and 112L in parallel with each other. The lower UV transmission window 112L is vertically separated into two rectangular spaces. Some of the UV LEDs 200 of the plurality of UV LEDs 200 are arranged in a two-dimensional matrix in a closed space below the upper UV transmitting window 112U, The UV light is irradiated through the first, second, third or fourth flow path f1, f2, f3 or f4. The remaining UV LEDs 200 of the plurality of UV LEDs 200 are arranged in a two-dimensional matrix in a closed space below the lower UV transmission window 112L and are arranged in a matrix through the UV transmission window 112U The UV light is irradiated into the first, second, third or fourth flow path (f1, f2, f3 or f4).

In addition, the greenhouse removing apparatus according to the present embodiment includes a buoyancy generating block 120, a plurality of column connecting members 300 connecting the first, second, and third bidirectional UV transmitting panels in a vertically spaced relationship, . The plurality of columnar connecting members 300 are configured to connect the buoyancy generating block 120 and the first, second and third bidirectional UV transmitting panels 110a, 110b, 110c, and 110d at their four corners do. The greenhouse removing apparatus 1 further includes a solar cell panel 400 connected to the underwater structure 100 through the connection member 300 or directly. The solar panel 400 can utilize the power obtained by using the sunlight to operate the plurality of UV LEDs 200. The solar cell panel 400 is exposed to the outside from the upper side of the underwater structure 100. The solar cell panel 400 preferably includes hinges 411 and 412 for controlling the position of the sun, It is preferable that the angle is adjusted by the driving unit 420. In addition, the algal removing device 1 may include a mooring line M so as to be moored at the position in a floating state.

2 and 3, the bidirectional UV transmission panels 110a, 110b and 110c (collectively referred to as 110) include an upper panel composed of an upper base 111U and an upper UV transmission window 112U, 111L and a lower UV transmission window 112L. The upper panel and the lower panel may be assembled such that the upper base 111U and the lower base 111L are in contact with each other. Although not shown in detail, the upper base 111U and the lower base 111L each include a PCB on which the plurality of UV LEDs 200 described above are mounted, and the above-described UV transmission window 112U or 112L, And a watertight type casing for accommodating the UV LEDs 200 in a watertight state.

2, the first bidirectional UV transmission panel 110a is configured such that the UV LEDs 200 arrayed in the upper base 111U transmit UV light through the upper UV transmission window 112U to the first While the UV LEDs 200 arranged in the lower base 111L irradiate UV light into the second flow path f2 through the lower UV transmission window 112L.

The second bidirectional UV transmitting panel 110b is configured such that the UV LEDs 200 arrayed in the upper base 111U irradiate the UV light into the second flow path f2 through the upper UV transmitting window 112U, The UV LEDs 200 arrayed in the lower base 111L irradiate the UV light into the third flow path f3 through the lower UV transmission window 112L.

The third bidirectional UV transmitting panel 110c is configured such that the UV LEDs 200 arrayed in the upper base 111U irradiate the UV light into the third flow path f3 through the upper UV transmitting window 112U, The UV LEDs 200 arrayed in the lower base 111L irradiate the UV light into the fourth flow path f4 through the lower UV transmission window 112L.

As described above, the algal cell removing device 1 according to the present invention is a device for removing algae cells and the like that cause a green algae by forming a desired number of channels along the whole underwater depth in which they are submerged, The organic material (r) can be removed. Particularly, in the case of the second flow path f2 and the third flow path f3, the upper UV LEDs and the lower UV LEDs of the vertically adjacent bidirectional UV transmitting panels 110a and 110b or 110b and 110c Since the UV light is intensively irradiated, the efficiency of removing green algae can be greatly increased.

In addition, the greenhouse removing apparatus 1 includes TiO ₂ in a path through which UV light is irradiated from the plurality of UV LEDs 200. In this embodiment, TiO ₂ as a photocatalyst can be coated on the upper UV transmission window 112U and / or the lower UV transmission window 112L. When irradiated with UV light energy under the TiO ₂ present it can be removed organic materials to produce a hydroxyl radical (OH-) to the TiO ₂ surface. The reaction of TiO ₂ with UV light has little effect on the aquatic ecosystem and there is no secondary pollution. It is preferable that the upper UV transmission window 112 and the lower UV transmission window 112L are formed of a quartz material that can withstand the worst environments such as rivers and coasts and has high UV transmission efficiency.

Referring to FIG. 4, the algal remover 1 may include a charger 610 and an auxiliary battery 620 for charging the solar panel 400 with the power obtained from the solar energy. When the solar panel 400 can not perform the power generating function due to the weather deterioration or the like, the power of the auxiliary battery 620 is set to be lower than the power of the auxiliary battery 620 .

The plurality of UV LEDs 200 may include UV A LEDs 200A of the UV A wavelength range (315 to 400 nm), UV B LEDs 200B of the UV B wavelength band (280 to 315 nm) And UV C LEDs 200C of the C wavelength band (100 to 280 nm wavelength band). The green tide removing apparatus 1 further includes a pollution degree measuring sensor 700 for measuring the pollution degree in the water and a pollution degree measuring sensor 700 for measuring the pollution degree of the UV LEDs 200A, 200B, And a control unit 800 for controlling operations.

In addition, since the degree of contamination varies depending on the depth of water, it is also possible to arrange the UV LEDs so that the wavelength band varies depending on the height. For example, UV LEDs of the first wavelength range may be disposed in the first bidirectional UV transmitting panel 110a located on the uppermost layer of the UV transmitting panels 110, and second bidirectional UVs positioned below the first bidirectional UV transmitting panel 110a. The UV LEDs of the second wavelength band may be disposed on the transmission panel 110b and the UV LEDs of the third wavelength band may be disposed on the third bidirectional UV transmission panel 110c located below the second bidirectional UV transmission panel 110b . Furthermore, even in a single UV transmission panel 110a, 110b or 110c, the wavelength band of the UV LED located on the upper layer and the wavelength band of the UV LED located on the lower layer are different from each other, so that it is possible to cope with the difference in contamination depending on the depth of water.

A dissolved oxygen concentration measuring sensor using a diaphragm electrode method may be used as the contamination degree measuring sensor 700. [ The dissolved oxygen concentration measuring sensor includes a cathode using gold, a cathode using silver, an oxygen permeable membrane, a current measuring device, and the like. When oxygen dissolved in water is reduced at the cathode which is an inactive electrode, a current flows in proportion to the dissolved oxygen concentration from the anode to the cathode, and the dissolved oxygen concentration can be measured by measuring the current with the current measuring apparatus.

The controller 800 controls the operation of the plurality of UV LEDs 200A, 200B, and 200C based on the measured dissolved oxygen concentration of the contamination level measuring sensor 700. When the measured dissolved oxygen concentration exceeds the first reference value The UV LEDs 200A, 200B and 200C are all turned off and the UV A LEDs 200A are turned on if the measured dissolved oxygen concentration is smaller than the first reference value and larger than the second reference value, And if it is smaller than the third reference value, it turns on the UV B LEDs 200B and if it is smaller than the third reference value, it turns on the UV C LEDs 200C. It is also possible to further divide the reference range of the measured dissolved oxygen concentration and to control the ON number of UV LEDs of the same wavelength band.

It is possible to use a plurality of pollution degree measuring sensors 700 and to use the pollution degree measuring sensors 700 of different pollution degree measuring methods to more precisely grasp and cope with the polluted environment in the water. The pollution degree of water can be measured by Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Dissolved Oxygen (DO) and the like. Biochemical oxygen demand is the amount of oxygen required for microbial respiration in the course of stabilization of pollutants by decomposition by aerobic bacteria of organic matter. If BOD is high, there is a lot of organic matter and it can be judged that there is pollution. The chemical oxygen demand is determined by the amount of oxygen required for oxidizing organic and inorganic substances in the water by an oxidizing agent. The amount of dissolved oxygen is the amount of oxygen dissolved in water, which is mainly dissolved in atmospheric oxygen or supplied to water by photosynthesis of aquatic plants.

5, the tide removing device 1 may be moved from land to remote water by the tugboat 2 and then moored in the water area. At this time, the algal remover 1 may further include a connection ring 901 for connection with a tug. In the present embodiment, the connection ring 901 is provided on the connection member 300, but the present invention is not limited thereto.

In addition, although the green tide removing apparatus 1 may be used alone in a specific water area as shown in FIG. 1, it may be used together with other green tide removing apparatus 1 as shown in FIG. 6 have. At this time, a connection loop 902 can be used for connection of two neighboring algal remover 1's. The connection ring 902 for connecting the two algal removers 1 and 1 with the sling L may be installed on the connection member 300 in the same manner as the connection ring 901 for connection with the tugboat.

7 and 8, the algal remover 1 further includes a surface cleaning unit 500 for wiping the surface of the upper or lower UV transmission window 112 of the bidirectional UV transmission panel 110 in water can do. The surface cleaning unit 500 includes a wiper 510 disposed across the width of the UV transmission window 112 and in contact with the surface of the UV transmission window 112, A guide member 520 for holding and guiding the end portion of the wiper 510 so as to linearly move at one side or both edges of the wiper 510 and a driving unit 530 for linearly driving the wiper 510. The driving unit 530 includes a motor 531, a screw 532 rotated by the motor 531, a screw 532 screw-connected to the screw 532 and fixed to the wiper 510 at one side, A transfer block 540 may be included. The wiper 510 may include a rigid bar 512 and a flexible adhesive bar 514 connected to the rigid bar 512. When the motor 831 is driven, the screw 532 rotates and the screw transfer block 540 rotates the wiper 510 in an arrow direction while being connected to the wiper 510 guided in a linear direction by the guide member 520. [ Direction.

It is also conceivable to use a surface cleaning unit including a wiper that is in close contact with the surface of the UV transmission window 112 and a driving unit that rotatably drives the wiper in such an adhered state. Furthermore, the use of a surface cleaning unit that removes foreign matter from the surface of the UV-transmitting window 112 while flowing by the flow of water while being in close contact with the surface of the UV-transmitting window 112 can be considered without using a separate driving unit .

Referring to FIGS. 9 and 10, a greenhouse removing apparatus according to another embodiment of the present invention will now be described.

According to the present embodiment, the algal elimination device 1 'is an apparatus used for suppressing and removing green algae in a certain part of a water body in a certain water area, and includes a plurality of channels F And a plurality of UV LEDs (200a, 200b, 200c) for irradiating the flow path (F) with UV light so as to inactivate algae cells existing in water forming the plurality of flow paths (F) Collectively referred to as 200 ').

In this case, the underwater structure 100 'includes a plurality of UV transmissive bending tubes 110' that form a plurality of flow paths F in the periphery, and the plurality of UV LEDs 200a, 200b, 200c 'Are arrayed in a curved pattern in the plurality of UV-transparent bending tubes 110'. The UV transmissive bending tube 110 ', which alternates between the U-shape and the inverted U-shape, forms a longer, more responsive flow path (F). The plurality of UV LEDs 200a, 200b and 200c (collectively referred to as 200 ') emit UV A LEDs 200a of the UV A wavelength range (315 to 400 nm) and UV B LEDs 200a of the UV B wavelength band (280 to 315 nm) LEDs 200b, and UV C LEDs 200c of UV C wavelength band (100-280 nm wavelength band). In the same manner as in the previous embodiment, the greenhouse removing apparatus 1 'includes a pollution degree measuring sensor for measuring the pollution degree in the water, and the UV LEDs 200a, 200b and 200c And a control unit for controlling the operation of the apparatus 200 '. The peripheral flow path of the UV transparent bending tube 110 'is in the UV light irradiation path of the UV LEDs 200a, 200b and 200c (collectively 200') arranged in the UV transparent bending tube 110 '. Therefore, it is preferable to coat TiO ₂ as a photocatalyst in the UV transmissive bending tube 110 '. Further, it is preferable that the UV-permeable bending tube 110 'is a UV-transparent material, particularly a quartz material.

The underwater structure 100 'includes a buoyancy generating block 120' as in the previous embodiment, and the UV-permeable bending pipes 110 'are coupled to the bottom of the buoyancy generating block 120'. In addition, the greenhouse removing apparatus 1 'further includes a solar cell panel 400' connected to the underwater structure 100 ', and the solar cell panel 400' And may be used to operate the plurality of UV LEDs 200a, 200b, 200c (collectively, 200 ').

100, 100 ': underwater structure 200, 200': UV LED
f1, f2, f3, f4, F:

Claims (17)

An underwater structure forming a plurality of flow paths in water;
A plurality of UV LEDs for irradiating the channel with UV light so as to inactivate algae cells present in the water flowing through the channel;
Wherein the underwater structure comprises a bi-directional UV transmission panel having an upper UV transmission window and a lower UV transmission window;
A sensor for measuring the degree of pollution in the water; And
And a controller for controlling the plurality of UV LEDs based on the pollution degree information measured by the pollution degree measuring sensor,
The plurality of UV LEDs include UV A LEDs having a UV A wavelength band, UV B LEDs having a UV B wavelength band, and UV C LEDs having a UV C wavelength band, And selectively controls the UV A LEDs, the UV B LEDs and the UV C LEDs according to the degree of contamination. The method of claim 1, wherein the plurality of UV LEDs comprises upper UV LEDs that are two-dimensionally arrayed below the upper UV transmission window to direct UV light into the channel through the upper UV transmission window, And lower UV LEDs arranged two-dimensionally on the upper portion of the lower UV transmission window to emit UV light into the channel through the lower UV transmission window. [3] The planting apparatus according to claim 2, wherein the underwater structure includes two or more bidirectional UV transmission panels arranged side by side. [5] The apparatus according to claim 3, wherein the plurality of channels includes a channel formed between adjacent two bidirectional UV transmission panels. [3] The planting apparatus according to claim 1, wherein the underwater structure includes a buoyancy generating block for generating buoyancy in a state where the water is partially immersed in water. [6] The planting apparatus according to claim 5, wherein the flow path includes a flow path formed between the bottom surface of the buoyancy generating block and the bidirectional UV transmission panel. [3] The apparatus according to claim 1, further comprising a surface cleaning unit for wiping the surface of the upper UV transmission window or the lower UV transmission window. [7] The apparatus according to claim 7, wherein the surface cleaning unit comprises a wiper contacting the surface, and a wiper driving unit that linearly or rotationally moves the wiper in contact with the surface. The greenhouse removing apparatus according to claim 1, further comprising a solar cell panel connected to the underwater structure in a state exposed above the water surface. delete delete delete [4] The apparatus according to claim 3, further comprising a connecting member for connecting the two or more bidirectional UV transmitting panels in a vertically spaced relationship. [3] The planting apparatus according to claim 1, further comprising a connection ring formed for connection to the greenhouse removing apparatus or connection to the tugboat. The green algae removing device according to claim 1, wherein TiO ₂ is contained in a path through which UV light is irradiated from the plurality of UV LEDs. [3] The apparatus according to claim 1, wherein the plurality of UV LEDs are arranged to have different wavelength ranges according to the depth of water. An underwater structure forming a plurality of flow paths in water;
A plurality of UV LEDs for irradiating the channel with UV light so as to inactivate algae cells present in the water flowing through the channel;
A sensor for measuring the degree of pollution in the water; And
And a controller for controlling the plurality of UV LEDs based on the pollution degree information measured by the pollution degree measuring sensor,
Wherein the underwater structure comprises a plurality of UV transmissive bend tubes forming a plurality of flow paths in the periphery, the plurality of UV LEDs are arranged in a curved pattern in the UV transmissive bend tube, and the UV The UV light is irradiated to the flow path formed around the transmissive bending tube,
The plurality of UV LEDs include UV A LEDs having a UV A wavelength band, UV B LEDs having a UV B wavelength band, and UV C LEDs having a UV C wavelength band, And selectively controls the UV A LEDs, the UV B LEDs and the UV C LEDs according to the degree of contamination.

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