Apparatus and method for providing algicidal bacteria carrying nitzschia

Abstract

To provide an apparatus and a method for providing algicidal bacteria carrying Nitzschia that do not affect the surrounding aquatic environment.SOLUTION: An apparatus includes a frame having an upper horizontal strut 11, a lower horizontal strut 12, and a vertical strut 13 supporting the upper horizontal strut and the lower horizontal strut; a blue light irradiation module 18 installed near the bottom of the frame to irradiate Nitzschia in the bottom sediment of the water body with blue light; a plurality of rollers 14 rotatably supported at each end of the upper and lower horizontal struts; Nitzschia carriers 15 which are stretched over a plurality of rollers, attaching and carrying Nitzschia 1 from the bottom sediment, and moving in circulation with the rotation of the plurality of rollers; and an algicidal bacteria housing box 16 which is installed on the path of movement of the Nitzschia carriers and housing an algicidal bacteria 2 inside to bring the Nitzschia carried on the Nitzschia carriers passing the inside into contact with the algicidal bacteria.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application relates to the field of application of microorganisms in the countermeasures against blue-green algae, and particularly to an apparatus and a method for providing a niche for immobilized algicidal bacteria.

Background Art

[0002] In recent years, the occurrence of blue-green algae in eutrophic water due to lake pollution has been increasing. When blue-green algae occur abnormally, it not only destroys the ecosystem and damages the landscape, but also causes problems such as strange odors in tap water. In particular, cyanobacteria (Microcystis), especially Microcystis spp. which are the dominant species in blue-green algae, produce toxic microcystin, which affects the health of humans and livestock.

[0003] Therefore, various countermeasure methods against blue-green algae have been developed over the years. Currently, as direct countermeasures at the site of blue-green algae, chemical methods such as algicide spraying, physical methods such as filtration, coagulation, sedimentation and separation recovery, and biological methods such as ecosystem control (biomanipulation, aquatic plant planting, etc.) are known. In addition, there are also methods such as sediment dredging, sand covering, and bottom layer oxygen introduction that suppress the supply of nutrients that promote cyanobacteria growth from the bottom sediment at the site. Furthermore, methods such as covering the water surface with a light-shielding curtain or vertically mixing the water area with aeration or a propeller to send cyanobacteria into the dark bottom layer, inactivate photosynthesis, and at the same time lower the water temperature and pH of the surface layer to suppress the growth of cyanobacteria have been implemented.

[0004] However, conventional countermeasures have many problems, such as requiring large-scale construction and costs, causing secondary pollution problems to the surrounding water quality, and also having an adverse impact on native biological groups other than cyanobacteria. In addition, the effect is limited to small water areas where the countermeasures are implemented, and a wide range of countermeasure effects cannot be obtained.

[0005] In addition, in order to minimize the impact on the surrounding water quality biological environment by implementing measures against blue-green algae, research has been conducted on methods of spraying algicidal bacteria and viruses that specifically act on blue-green algae. However, this approach originally has the problem of introducing foreign microorganisms that do not originally exist in the waters targeted for the measures. In addition, since algicidal bacteria and viruses act on many types of algae, there is also the problem of killing other native algae.

Summary of the Invention

[0006] Therefore, in order to solve at least some of the above problems, the present application proposes an apparatus and a method for providing a nichea (Nitzschia) that specifically acts on cyanobacteria present at the site and carries an algicidal bacterium thereon to achieve the purpose of specifically acting on cyanobacteria.

[0007] According to one aspect of the present invention, there is provided an apparatus for providing an algicidal bacterium-carrying nichea, comprising: a frame including an upper horizontal support, a lower horizontal support, and vertical supports supporting the upper and lower horizontal supports; a blue light irradiation module installed at a position close to the bottom of the frame for irradiating blue light onto the nichea in the bottom sediment of the water area; a plurality of rollers rotatably supported at respective ends of the upper and lower horizontal supports; a nichea carrier stretched over the plurality of rollers, which adheres to and carries the nichea from the sediment and circulates as the plurality of rollers rotate; and an algicidal bacterium accommodation box installed on the movement path of the nichea carrier, which accommodates algicidal bacteria inside and brings the nichea carried on the nichea carrier passing through the inside into contact with the algicidal bacteria.

[0008] According to another aspect of the present invention, the apparatus for providing the algicidal bacterium-carrying niche A is placed on the bottom layer of the water area, and the bottom sediment of the water area is irradiated with blue light by the blue light irradiation module to activate the niche A in the bottom sediment. By rotationally driving a plurality of rollers to circulate and move the niche carrier, the niche carrier comes into contact with the bottom sediment and adheres to the activated niche A, and passes through the algicidal bacterium-containing box in which the algicidal bacteria are accommodated while carrying the niche A, thereby generating an algicidal bacterium-carrying niche A and transporting it to the surface layer of the water area to contact the cyanobacteria in the surface layer, and a method for providing the algicidal bacterium-carrying niche A is provided.

Effects of the Invention

[0009] According to the present invention, by irradiating the bottom sediment of the water area with blue light, the niche A in the bottom sediment is preferentially activated, the activated niche A is carried and transported by the niche carrier, brought into contact with the algicidal bacteria to form an algicidal bacterium-carrying niche A, the algicidal bacterium-carrying niche A is transported to the surface layer of the water area, and finally infects the cyanobacteria, decomposes, lyses, and suppresses the cyanobacteria.

[0010] By utilizing the niche A that specifically acts on the existing cyanobacteria and carrying the algicidal bacteria thereon, it specifically acts on the cyanobacteria, so that the introduction of foreign biological species can be prevented and the influence on other native algae can be suppressed.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Embodiments for Carrying Out the Invention

[0012] In order to make the object, technical means, and beneficial technical effects of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the drawings. It should be understood that the embodiments described in this specification are merely for explaining the present invention and do not limit the present invention.

[0013] Facing the problems existing in the prior art, the inventors of the present application conducted intensive research on the countermeasures against the microorganisms of water blooms for a long time, and found that niche A specifically acts on cyanobacteria (Microcystis) in water blooms.

[0014] To confirm this finding, the inventors of the present application conducted a culture experiment on the adhesion characteristics of niche A to cyanobacteria (Microcystis) colonies. In this experiment, 1. a cyanobacteria single system, 2. a coexistence system in which cyanobacteria and niche A were placed in the same container, and 3. a system in which a bamboo support with a diameter of 2 mm and a height close to the liquid surface of the culture solution was placed in the above two systems so that niche A could move to the surface layer and come into contact with cyanobacteria were designed. Three types of the above culture systems with 100 ml of culture solution were prepared and statically cultured for 14 days under the culture conditions of 2000 lux of white fluorescent lamps, a light cycle of 12 h light / 12 h dark, and a temperature of 25°C, and experimental results as shown in Table 1 below were obtained.

[0015]

Table 1

[0016] By experiments, cyanobacteria growth occurred in System 1, while cyanobacteria reduction was confirmed in coexistence systems with other niches. In particular, in System 3 where cyanobacteria and nichea were in contact, a phenomenon was observed where nichea adhered to, invaded, and grew on the surface and inside of cyanobacteria cell colonies. Many colonies settled, and it was confirmed that the floating cyanobacteria were suppressed to 1 / 10 compared to the monoculture of cyanobacteria. As a result, it became clear that nichea has the property of specifically adhering to cyanobacteria colonies.

[0017] However, in nature, cyanobacteria float on the surface layer of water areas, while nichea are mainly distributed in the bottom sediment and on the sediment surface at the bottom layer and have attachment mobility. Therefore, the two hardly come into contact. Nichea in the sediment on or in the bottom layer of the water area do not grow in a dormant state because they are not exposed to light or have insufficient light irradiation. Since nutrient salts are abundant in the bottom layer of the water area, conditions other than light are satisfied for the growth of nichea. Therefore, dormant nichea in the sediment become activated and grow when exposed to light. The inventors of the present application discovered that blue light irradiation has the effect of preferentially promoting the growth of nichea with respect to growth by light irradiation. To confirm this finding, the inventors of the present application conducted the following culture comparison experiments. When 2 g of eutrophic lake sediment was added to 100 mL of culture solution and cultured for 7 days at a temperature of 25°C under irradiation with a photon flux of approximately 100 μmol·m-2·s-1 and a light cycle of 12 h light / 12 h dark using a white LED and a blue LED respectively, the experimental results shown in Table 2 below were obtained.

[0018]

Table 2

[0019] As a result of the experiment, various algae grew under white light irradiation, while green algae and cyanobacteria hardly grew under blue light irradiation, and nichea grew approximately 100 times. Thus, it was confirmed that blue light irradiation has the effect of preferentially promoting the growth of nichea.

[0020] Based on the above findings, the inventors of the present application further proposed a solution means that specifically acts on cyanobacteria by nichea in the sediment of the water area to be addressed.

[0021] Hereinafter, with reference to FIGS. 1 to 4, an apparatus and a method for providing an algicidal bacterium-encapsulated niche A according to an embodiment of the solution means of the present application will be described. FIG. 1 is a schematic diagram showing the configuration of an apparatus for providing an algicidal bacterium-encapsulated niche A according to an embodiment of the present application, and FIG. 2 is a schematic diagram showing the configuration as viewed from the left side of the apparatus for providing the algicidal bacterium-encapsulated niche A. FIGS. 3A and 3B are schematic diagrams showing deformations due to the water level of the apparatus for providing an algicidal bacterium-encapsulated niche A according to an embodiment of the present application, and FIG. 4 is a schematic diagram of a control configuration for controlling the deformation due to the water level of the apparatus for providing the algicidal bacterium-encapsulated niche A.

[0022] As shown in FIGS. 1 and 2, the apparatus 10 for providing an algicidal bacterium-encapsulated niche A includes a frame including an upper horizontal support 11, a lower horizontal support 12, and a vertical support 13 that supports the upper horizontal support 11 and the lower horizontal support 12. Here, it is preferable to provide the upper and lower horizontal supports 11 and 12 and the vertical support 13 on the front side and the back side of the paper surface in FIG. 1, respectively, to support the apparatus more stably and firmly. Rollers 14 are rotatably supported between the ends of the two upper horizontal supports 11 and between the ends of the two lower horizontal supports 12, respectively. For example, four rollers 14 are attached to the four corners of FIG. 1.

[0023] On these rollers 14, a niche carrier 15 that adheres to and supports niches from the sediment of the water area and circulates as the plurality of rollers 14 rotate is stretched. Specifically, the niche carrier 15 includes a belt-shaped carrier 151 that is stretched on the plurality of rollers 14 and circulates as the plurality of rollers 14 rotate, and a niche induction carrier 152 that is provided on the surface of the belt-shaped carrier 151 and adheres to the niche 1 by contacting the sediment of the water area. The niche is classified as adherent diatoms, has thin fibrous substances outside the cells, and has the property of adhering to and moving on the surface of all substances such as chemical fibers, natural fibers, glass, natural soil, stones, and aquatic plants. The belt-shaped carrier 151 may be formed of any substance as long as it is not slippery and the niche does not adhere and fall off. For example, it can be formed of a resin film, and preferably formed of a light-transmissive resin film so as not to block light irradiation to the maximum extent. Further, it is preferably formed of a resin film that transmits blue light. A large number of niche induction carriers 152 are provided on the surface of the belt-shaped carrier 151. One end of the niche induction carrier 152 is fixed to the surface of the belt-shaped carrier 151, and the other end is a free end, so that it hangs downward by its own weight. The niche induction carrier 152 is preferably formed in a fibrous shape so that the niche can move between the fibers. The niche induction carrier 152, like the belt-shaped carrier 151, may be formed of any substance as long as it is not slippery and the niche does not adhere and fall off, and may be formed of the same material as the belt-shaped carrier 151 or a different material.

[0024] As shown in FIG. 2, one niche carrier 15 may be provided, or a plurality of niche carriers 15 may be arranged in parallel.

[0025] The apparatus 10 for providing a niche with an algicidal bacterium carrier further includes an algicidal bacterium storage box 16 for storing the algicidal bacterium 2. The algicidal bacterium storage box 16 is arranged in the circulation path of the niche carrier 15. As the niche carrier 15 circulates through the algicidal bacterium storage box 16, the algicidal bacterium 2 in the box contacts the niche carrier 15 and adheres to the niche 1 carried on the niche carrier 15, forming a niche with an algicidal bacterium carrier (a niche with an algicidal bacterium carried).

[0026] The device 10 for providing the niche for immobilized algicidal bacteria may further include an algicidal bacteria supply tank 17 that stores the algicidal bacteria 2 and supplies the algicidal bacteria 2 to the algicidal bacteria storage box 16 via a hose or the like. The algicidal bacteria supply tank 17 is provided above the water surface and can supply the algicidal bacteria 2 to the algicidal bacteria storage box 16 by utilizing the water head difference. The algicidal bacteria supply tank 17 may also be installed below the water surface. In this case, it is possible to supply the algicidal bacteria 2 by means of a pump or the like. The algicidal bacteria can be separated from the target water area, cultured in large quantities and used, or purchased from the outside and used.

[0027] The device 10 for providing the niche for immobilized algicidal bacteria is provided with a blue light irradiation module 18 at a position close to the bottom of the frame. The blue light irradiation module 18 irradiates the niche 1 in the bottom sediment of the water area with blue light to activate the niche 1. The blue light irradiation module 18 may be provided, for example, above the niche carrier 15. In this case, the niche carrier 15 is preferably formed of a light-transmissive resin film so as not to block the light irradiation to the maximum extent. As the light source of the blue light irradiation module 18, a blue LED can be used. Specifically, it can be formed by a blue LED array mounted on a substrate. Further, the light source may be composed of a white LED and a blue filter. Specifically, a white LED array is mounted on a substrate, and a blue filter layer can be applied or a blue filter can be coated on this LED array to form it. The irradiation of the blue light is not limited to this, and any existing blue light irradiation means can be used.

[0028] The device 10 for providing the niche for immobilized algicidal bacteria may be provided with wheels 19 at the bottom to support the device and make it easy to move.

[0029] In addition, in order to sufficiently contact the niche A1 moved from the bottom layer to the surface layer with the cyanobacteria 3 near the water surface, it is necessary to always position the niche carrier 15 directly below the water surface. In order to always position the niche carrier 15 carrying the niche with the algicidal bacteria carrier at a predetermined water depth, in this embodiment, as shown in FIGS. 1, 3A, and 3B, the upper horizontal strut 11 of the device 10 for providing the niche with the algicidal bacteria carrier is formed as a horizontally expandable and contractible strut, and the vertical strut 13 is formed as a vertically expandable and contractible strut. Further, in the device 10 for providing the niche with the algicidal bacteria carrier, a support arm 20 is erected at a position having the same height as the uppermost part of the niche carrier 15, and an upper water level sensor 21 and a lower water level sensor 22 are provided on the support arm 20 side by side in the vertical direction while maintaining a predetermined distance from the uppermost part of the niche carrier 15. In the drawings, the algicidal bacteria supply tank 17 is provided on the support arm 20, and the water level sensors 21 and 22 are provided on the algicidal bacteria supply tank 17, but the algicidal bacteria supply tank 17 may be provided at a position different from the water level sensors 21 and 22. The upper and lower water level sensors 21 and 22 output an electric signal indicating whether they are in contact with water. As shown in FIG. 4, the providing device 10 further includes a control unit 23. The control unit 23 receives the electric signals output from the upper and lower water level sensors 21 and 22, and based on the received electric signals, the uppermost part of the niche carrier 15 is at a predetermined water depth position. In FIG. 1, the part of the niche carrier 15 where the niche with the algicidal bacteria carrier is carried between the two upper rollers is at a predetermined water depth position, and the expansion and contraction of the upper horizontal strut 11 and the vertical strut 13 are controlled.

[0030] In this embodiment, when the electrical signal received from the upper water level sensor 21 indicates that it is in contact with water, as shown in FIG. 3A, the control unit 23 controls the expansion and contraction of the upper horizontal support 11 and the vertical support 13 such that the upper horizontal support 11 contracts and the vertical support 13 extends until the electrical signal received from the upper water level sensor 21 becomes an electrical signal indicating that it is not in contact with water. Further, when the electrical signal received from the lower water level sensor 22 indicates that it is not in contact with water, as shown in FIG. 3B, the control unit 23 controls the expansion and contraction of the upper horizontal support 11 and the vertical support 13 such that the upper horizontal support 11 extends and the vertical support 13 contracts until the electrical signal received from the lower water level sensor 22 becomes an electrical signal indicating that it is in contact with water. In this way, the control unit 23 automatically expands and contracts the upper horizontal support 11 and the vertical support 13 so that the upper water level sensor 21 is in the air and the lower water level sensor 22 is in the water, whereby the portion of the niche carrier 15 on which the algicidal bacteria-carrying nichea is carried, that is, the portion between the two upper rollers 14 of the niche carrier 15 shown in FIGS. 1, 3A, and 3B can always be positioned at a predetermined water depth.

[0031] Here, for example, as the upper and lower water level sensors 21 and 22, a conductivity sensor through which an electric current flows when in contact with water can be used. In this case, when the control unit 23 receives an electrical signal from the conductivity sensor, it determines that the conductivity sensor is in contact with water, and when it does not receive an electrical signal from the conductivity sensor, it determines that the conductivity sensor is not in contact with water.

[0032] The water depth position of the uppermost part of the niche carrier 15, that is, the part on which the algicidal bacteria-carrying nichea is carried in FIG. 1, is determined by the support arm 20 that supports the water level sensor. The support arm 20 can be formed as an adjustable arm that can expand and contract, and by expanding and contracting, the uppermost part of the niche carrier 15 can be adjusted to a predetermined water depth. For example, the predetermined water depth position is preferably the water layer where cyanobacterial colonies aggregate. For example, it can be a water depth position of 2 cm to 10 cm.

[0033] The configuration of the apparatus 10 for providing the algicidal bacteria-carrying niche A has been described above. Next, the measures against cyanobacteria by the apparatus 10 for providing the algicidal bacteria-carrying niche A will be described.

[0034] When treating cyanobacteria 3, the apparatus 10 for providing the algicidal bacteria-carrying niche A according to the embodiment of the present application is placed on the bottom of the water area to be countermeasures, and the power is turned on to start the apparatus. Therefore, the blue light irradiation module 18 at the bottom of the apparatus irradiates the bottom sediment with blue light to activate and grow the niche A in the shallow layer of the sediment and on the sediment. At the same time, the rollers 14 pivotally supported at the ends of the upper and lower horizontal struts 11 and 12 rotate by the drive of a motor (not shown) connected to at least one of these rollers, and the niche carrier 15 is slowly circulated and moved. When the niche carrier 15 moves to the bottom of the water, the niche induction carrier 152 on its surface contacts the sediment, and the activated and grown niche A in the sediment adheres to the niche induction carrier 152 and continues to grow under the irradiation of blue light. Next, as the niche carrier 15 moves in the direction of the water surface, the niche A is transported to the surface layer of the water area. When moving to the surface layer of the water area, the niche induction carrier 152 covers the belt-shaped carrier 151, thereby preventing the deviation of the niche A. The niche carrier 15 continues to move to the surface layer and passes through the algicidal bacteria storage box 16 installed at a position close to the surface layer. The algicidal bacteria 2 having the effect of decomposing the cyanobacteria supplied from the algicidal bacteria supply tank 17 in the algicidal bacteria storage box 16 contacts and adheres to the niche A on the niche carrier 15 to form an algicidal bacteria-carrying niche. The algicidal bacteria-carrying niche is transported to the surface layer of the water area as the niche carrier 15 moves, specifically adheres to the cell population of the cyanobacteria floating on the surface layer, and penetrates into the interior, thereby infecting the cyanobacteria with the algicidal bacteria 2, decomposing the cyanobacteria, and making it easier to kill the algae. In addition, the cyanobacteria infected with the niche can spread over a wide range along with the flow of the surface water, continue to spread the infection to the healthy cyanobacteria in contact, and further expand the infection of the algicidal bacteria 2 over a wider range, which can help suppress the cyanobacteria in the entire water area.

[0035] As described above, according to the invention of the present application, by combining blue light irradiation that preferentially activates and proliferates niche A, and a niche A carrier that attaches niche A on the substrate and thus moves it to the surface layer where cyanobacteria exist, it is possible to specifically act on cyanobacteria by utilizing niche A that already exists locally.

[0036] Also, in the embodiment of the present invention, since light irradiation is performed by an LED and the niche A carrier is gently moved, it can be implemented with only a small amount of energy and small-scale equipment. For example, it can be implemented only with green energy by using local solar power or wind power generation and power storage.

[0037] Moreover, according to the present invention, since only light irradiation is performed and no substances or chemicals are brought in from the outside, it does not affect the surrounding water environment. Moreover, since niche A that already exists in the sediment of the water area to be treated is utilized, no alien species are brought in at all.

[0038] Furthermore, according to the present invention, by sufficiently utilizing niche A that specifically acts on cyanobacterial blooms and attaching and supporting algicidal bacteria, it is possible to specifically decompose and dissolve cyanobacterial blooms.

[0039] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and can be changed and modified without departing from the spirit of the present invention. Each of the above-described embodiments includes substantially the same aspects and can be combined as appropriate. It is obvious that all other embodiments obtained by those skilled in the art without creative labor based on the embodiments of the present invention are also included within the scope of protection of this application.

Explanation of Reference Numerals

[0040] 1 - Nitchia, 2 - Algae-lysing bacteria, 3 - Cyanobacteria, 10 - Device for providing algae-lysing bacteria-encapsulated Nitchia, 11 - Upper horizontal support, 12 - Lower horizontal support, 13 - Vertical support, 14 - Roller, 15 - Nitchia carrier, 151 - Belt-shaped carrier, 152 - Nitchia induction carrier, 16 - Algae-lysing bacteria storage box, 17 - Algae-lysing bacteria supply tank, 18 - Blue light irradiation module, 19 - Wheel, 20 - Support arm, 21 - Upper water level sensor, 22 - Lower water level sensor, 23 - Control unit.

Claims

1. A frame comprising an upper horizontal support, a lower horizontal support, and vertical supports that support the upper horizontal support and the lower horizontal support; A blue light irradiation module installed at a position close to the bottom of the frame, which irradiates blue light onto the niche of the bottom sediment of the water area; A plurality of rollers rotatably supported at each end of the upper horizontal support and the lower horizontal support respectively; A niche carrier stretched over the plurality of rollers, which adheres to and supports the niche from the bottom sediment and circulates as the plurality of rollers rotate; An algicidal bacteria storage box installed on the movement path of the niche carrier, which contains algicidal bacteria inside and brings the niche carried by the niche carrier passing through the inside into contact with the algicidal bacteria; An apparatus for providing an algicidal bacteria-carrying niche, characterized by comprising the above.

2. The apparatus for providing an algicidal bacteria-carrying niche according to claim 1, further comprising an algicidal bacteria supply tank for storing algicidal bacteria and supplying the algicidal bacteria to the algicidal bacteria storage box.

3. The niche carrier is A belt-shaped carrier stretched over the plurality of rollers and circulating as the plurality of rollers rotate; A niche induction carrier provided on the surface of the belt-shaped carrier, which adheres to the niche by contacting the bottom sediment; The apparatus for providing an algicidal bacteria-carrying niche according to claim 1, characterized by comprising the above.

4. The niche induction carrier according to claim 3, wherein one end is fixed to the surface of the belt-shaped carrier and the other end is a free end, and it is provided in a fibrous form on the surface of the belt-shaped carrier.

5. The apparatus for providing an algicidal bacteria-carrying niche according to claim 1, characterized in that the niche carrier is one or a plurality arranged in parallel.

6. The apparatus for providing a niche for immobilizing algicidal bacteria according to claim 3, wherein the belt-shaped carrier is formed of a light-transmissive resin film.

7. The apparatus for providing a niche for immobilizing algicidal bacteria according to claim 1, wherein the blue light irradiation module includes a blue LED.

8. The upper horizontal support column is a horizontally expandable and contractible column, and the vertical support column is a vertically expandable and contractible column. An upper and a lower water level sensor which are vertically arranged one above the other via a support arm at a position a predetermined distance higher than the uppermost part of the niche carrier, and which output an electrical signal indicating whether or not they are in contact with water. A control unit which receives the electrical signal output from the upper and lower water level sensors, and controls the expansion and contraction of the upper horizontal support column and the vertical support column based on the received electrical signal so that the uppermost part of the niche carrier is at a predetermined water depth position. The apparatus for providing a niche for immobilizing algicidal bacteria according to claim 3, further comprising the above.

9. The apparatus for providing a niche for immobilizing algicidal bacteria according to claim 8, wherein the support arm is an expandable and contractible arm which adjusts the predetermined water depth position by expanding and contracting.

10. Place the apparatus for providing a niche for immobilizing algicidal bacteria according to any one of claims 1 to 9 on the bottom layer of the water area. Irradiate blue light onto the bottom sediment of the water area by the blue light irradiation module to activate the niche in the bottom sediment. Rotate and drive the plurality of rollers to circulate and move the niche carrier, so that the niche carrier adheres to the activated niche in contact with the bottom sediment, and the algicidal bacteria-containing box containing the algicidal bacteria while carrying the niche passes through, thereby generating an algicidal bacteria-immobilized niche and transporting it to the surface layer of the water area to contact the cyanobacteria in the surface layer. A method for providing an algicidal bacterium-encapsulated niche A, characterized by the following.

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