Method suitable for culturing photosynthetic organisms on water surface

Abstract

The invention discloses a method suitable for culturing photosynthetic organisms on the water surface, and the method comprises the following steps: culturing the photosynthetic organisms in a device for culturing the photosynthetic organisms under the condition of culturing the photosynthetic organisms, the culture device comprises a photosynthetic organism culture area floating on the water surface, a fixing part, a columnar hard elbow and a cleaning device, the photosynthetic organism breeding area is composed of a soft tubular reactor, the two ends of the soft tubular reactor are connected with hollow columnar hard elbows, the soft tubular reactor floats on the water surface through a fixing part, a light-transmitting part in the photosynthetic organism breeding area is made of a light-transmitting material, breeding liquid in the soft tubular reactor is stirred by means of fluctuation of the water surface, and therefore the photosynthetic organism breeding area is formed. Photosynthetic organism inoculation is performed through the hollow columnar hard elbow, nutrient substances are supplemented, and the photosynthetic organism culture device has the advantages of no land area occupation, low energy consumption, low reactor cost, simplicity in manufacturing, convenience in operation and the like, can effectively improve the yield of photosynthetic organisms, and is suitable for large-scale culture of photosynthetic organisms by utilizing idle water surfaces.

Description

Technical Field

[0001] The invention relates to the field of biotechnology, and in particular to a method suitable for cultivating photosynthetic organisms on water surfaces. Background Art

[0002] Photosynthetic organisms are organisms that can use light to grow and reproduce, such as photosynthetic bacteria and microalgae. Microalgae are a class of low-level plants that grow in water and are extremely widespread. They are cell factories driven by sunlight. Through efficient photosynthesis of microalgae cells, they absorb CO2, convert light energy into chemical energy of carbohydrates such as fat or starch, and release O2. Microalgae biomass is rich in protein, polyunsaturated fatty acids (EPA, DHA), polysaccharides, a variety of bioactive substances, natural pigments (chlorophyll, carotenoids), etc. These unique primary or secondary metabolites have complex chemical compositions and are potential resources for the production of medicines, fine chemicals and new fuels. At present, the bottleneck restricting the industrialization of microalgae is the large-scale cultivation of microalgae, the core of which is the photobioreactor.

[0003] Microalgae are generally cultured in photobioreactors (photosynthetic biological culture devices). There are currently two main types of photobioreactors: open and closed. Open photobioreactors, represented by raceway pools, have the advantages of low construction cost, low energy consumption, and easy maintenance; the main disadvantages are that the concentration of microalgae is relatively low, it is greatly affected by external environmental factors, it occupies a large area, and the amount of water evaporation is large. Closed photobioreactors, such as tubular, column, and plate types, have the advantages of greatly increasing the concentration of microalgae, being less susceptible to pollution, and having good product quality; the disadvantages are that the reactor cost is high, the energy consumption of the breeding process is high, and the cleaning and temperature control problems are difficult to solve. Most of these photobioreactors are only suitable for terrestrial breeding.

[0004] In addition to being cultivated on land, microalgae can also be cultivated on the water surface. Cultivating microalgae on the water surface has many advantages. For example, the water body fluctuation can be used to mix and stir the microalgae in the photobioreactor, reducing the energy consumption in the microalgae cultivation process; the buoyancy of the water body has a good supporting effect on the photobioreactor, slowing down the bearing capacity of the photobioreactor, and can reduce the requirements for the strength of the photobioreactor manufacturing materials and reduce the equipment cost; the temperature fluctuation in the water body is smaller than that on land, avoiding too low or too high temperature affecting the growth of microalgae; according to local conditions, large-scale cultivation of microalgae can also be carried out in areas with abundant water and scarce land resources. Traditional photobioreactors are mainly designed based on land and are not suitable for water surface cultivation. There are also reports on floating photobioreactors on the water surface in the prior art, but the design of photobioreactors is mostly complex, and there are disadvantages such as high investment and difficulty in operation and maintenance during large-scale application. In view of the water surface aquaculture environment and combined with the problems existing in the existing photobioreactors, a photobioreactor and a photosynthetic organism cultivation method that are simple to make, easy to operate, low in energy consumption, and suitable for large-scale cultivation are proposed. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art in culturing photosynthetic organisms, such as high investment cost, complex production, and high energy consumption, and to provide a method for large-scale cultivation of photosynthetic organisms at low cost and low energy consumption for aquaculture environments.

[0006] In order to achieve the above-mentioned purpose, a method suitable for cultivating photosynthetic organisms on the water surface is proposed, wherein the method comprises cultivating photosynthetic organisms in a device for cultivating photosynthetic organisms under conditions for cultivating photosynthetic organisms, wherein the device comprises a photosynthetic organism cultivation area floating on the water surface, a fixing part, a columnar hard elbow and a cleaning device. The photosynthetic organism cultivation area is composed of a soft tubular reactor, both ends of which are respectively connected to the columnar hard elbows, and the soft tubular reactor floats on the water surface through the fixing part. The photosynthetic organisms are inoculated, harvested and supplemented with nutrients required for cultivation through the columnar hard elbows.

[0007] The photosynthetic organism breeding area is made of light-transmitting materials. The photosynthetic organisms are cultured by sunlight. The soft tubular reactor floats on the water surface and is stirred by the fluctuation of the liquid surface. There is air above the culture liquid, and there is at least one air supply pipeline under the culture liquid, which is used for exhaust and air supply respectively. The gas supplemented by the air supply pipeline can be air, CO2-rich gas, and other gases required for the growth of photosynthetic organisms.

[0008] The columnar hard elbow is an "L"-shaped hollow columnar elbow, fixed to the bottom of the water. One end of the columnar hard elbow is open on the water surface and is used for inoculation, feeding and harvesting. The other end is connected to the soft tubular reactor. The soft tubular reactor is sleeved on the outside of the columnar hard elbow and connected with a cable tie, a hoop or other parts that can tightly connect the two pipe openings. The connection between the soft tubular reactor and the columnar hard elbow must ensure a tight seal without liquid leakage, and it must be easy to disassemble and easy to replace the soft tubular reactor. The columnar hard elbow is connected to the photosynthetic organism harvesting device, and the aquaculture liquid is pumped into the harvesting device for harvesting through a pump. The harvested aquaculture residual liquid is returned to the soft tubular reactor for continued cultivation.

[0009] The soft tubular reactor is connected to a fixing part, which may be a fixing column, a fixing net, a fixing fence, or a combination of several fixing methods, and is used to fix the position of the soft tubular reactor in the water and adjust the position of the soft tubular reactor according to the water surface position to avoid affecting the growth of photosynthetic organisms due to obstruction by the water surface.

[0010] Spraying devices are arranged on both sides or around the flexible tubular reactor to clean dust, water stains and other pollutants that block light on the outer surface of the flexible tubular reactor.

[0011] The cleaner is located on one side of the columnar hard elbow. The cleaner is made of a brush or sponge or other materials that can clean the inner wall of the soft tubular reactor. Both ends of the cleaner are fixed on the pulling rope, and the cleaner moves back and forth in the breeding area by pulling the rope.

[0012] The shape of the cleaning device is arc-shaped, and preferably the arc only covers the light-transmitting part of the soft tubular reactor.

[0013] The photosynthetic organisms include microalgae and photosynthetic bacteria, and the microalgae are preferably filamentous algae or spiral algae. The conditions for culturing photosynthetic organisms include: a temperature of 10-45° C. and a light intensity of 1000-200000 lux.

[0014] The method for cultivating photosynthetic organisms provided by the present invention has the advantages of low investment, low energy consumption and easy large-scale cultivation. The soft tubular reactor for cultivating photosynthetic organisms is designed to be divided into two parts, one part is fixed to the bottom of the water, and serves as a fixed support and installation accessory for the soft tubular reactor; the other part floats in the water, which is easy to assemble and disassemble, and effectively solves the problem that the existing photobioreactor is severely shaded and difficult to continue to use after long-term cultivation. In addition, the advantages of the water body are fully utilized to reduce costs and energy consumption. Due to the buoyancy of the water body, the strength requirements of the soft tubular reactor material are greatly reduced, and it can be made of cheap materials, reducing the investment cost of the reactor; the water surface fluctuation can be used to mix and stir the microalgae in the photobioreactor, thereby reducing the energy consumption during the microalgae cultivation process; for areas with abundant water surfaces and scarce land resources, it is suitable for large-scale cultivation of photosynthetic organisms.

[0015] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a side view of a device for culturing photosynthetic organisms according to a preferred embodiment of the present invention.

[0017] Figure 2 for Figure 1 A top view of a device for culturing photosynthetic organisms is shown.

[0018] Figure 3 is the growth curve of the photosynthetic organism in the embodiment;

[0019] Description of Reference Numerals

[0020] 1. Air supply pipeline; 2. Pull rope; 3. Cleaner fixing shaft; 4. Cleaner; 5. Connection between soft tubular reactor and columnar hard elbow; 6. soft tubular reactor; 7. Columnar hard elbow; 8. Fixed column; 9. Fixed ring on the soft tubular reactor. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0022] In the present invention, unless otherwise specified, directional words such as "up, down, top, bottom" are usually used with reference to the directions shown in the drawings or are used to describe the relative positional relationships of components in the vertical, perpendicular or gravity direction.

[0023] like Figure 1 and Figure 2 As shown, the present invention provides a method for cultivating photosynthetic organisms, the method comprising cultivating photosynthetic organisms in a device for cultivating photosynthetic organisms under conditions for cultivating photosynthetic organisms, the cultivation device comprising a photosynthetic organism cultivation area floating on the water surface, a fixing portion, a columnar hard body elbow 7 and a cleaning device. The photosynthetic organism cultivation area is composed of a soft tubular reactor 6, both ends of the soft tubular reactor 6 are respectively connected to the columnar hard body elbow 7, and the soft tubular reactor 6 floats on the water surface through the fixing portion. The photosynthetic organisms are inoculated, harvested and supplemented with nutrients required for cultivation through the columnar hard body elbow.

[0024] The purpose of the present invention is to provide a method for large-scale cultivation of photosynthetic organisms on water surfaces with low cost and low energy consumption. Therefore, firstly, the special advantages of the water surface environment are fully utilized, and combined with the needs of microalgae cultivation, the construction cost is reduced through ingenious design in terms of photobioreactor manufacturing materials, internal structure and reuse; then, the photosynthetic organisms are stirred by means of water surface fluctuations and air bubbling, thereby reducing the energy consumption of cultivation; finally, a method for large-scale cultivation of photosynthetic organisms on water surfaces is provided through the design of a photobioreactor that is easy to assemble and disassemble.

[0025] In the present invention, the device for cultivating photosynthetic organisms includes a photosynthetic organism breeding area floating on the water surface, a fixing part, a columnar hard elbow and a cleaning device. The photosynthetic organism breeding area is designed as a soft tubular reactor and the two ends are connected to the columnar hard elbow. The soft tubular reactor is sleeved on the outside of the columnar hard elbow and connected with a cable tie, a hoop or other parts that can connect the two pipe openings tightly. The connection 5 between the soft tubular reactor and the columnar hard elbow must ensure that the seal is tight and does not leak liquid, and it must be easy to disassemble and convenient for the replacement of the soft tubular reactor. Such a design makes it easy to replace only the soft tubular reactor, which effectively solves the problem that the existing photobioreactor is severely shaded and difficult to continue to use after long-term cultivation, and reduces the construction cost of the device.

[0026] The soft tubular reactor is a tubular shape that is easy to process, and makes full use of the buoyancy of the water body. It is made of transparent materials with low strength, and only the light-transmitting part can be transparent. This greatly reduces the difficulty and cost of making the soft tubular reactor. During the breeding process, photosynthetic organisms and their extracellular secretions will have varying degrees of wall adhesion. As the breeding time increases, these substances gradually accumulate and are difficult to clean. The shading phenomenon is serious, which greatly reduces the growth rate of photosynthetic organisms. The soft tubular reactor, which is simple to make, low-cost and easy to replace, solves this problem very cleverly. After a period of breeding, when the pollutants in the soft tubular reactor accumulate more and are difficult to clean, the soft tubular reactor can be replaced to improve the breeding efficiency of photosynthetic organisms and reduce the depreciation cost of reactors for large-scale breeding of photosynthetic organisms.

[0027] The columnar hard elbow is an "L"-shaped hollow columnar elbow fixed to the bottom of the water. One end of the columnar hard elbow is connected to the soft tubular reactor, supporting the soft tubular reactor, so that a cavity is formed in the soft tubular reactor, with air above the cavity and culture fluid below. There is at least one gas supply pipeline 1 at the bottom of the culture fluid, which is used for exhaust and gas supply respectively. The gas supplemented by the gas supply pipeline 1 can be air, CO2-rich gas, and other gases required for the growth of photosynthetic organisms. The other end of the columnar hard elbow is open on the water surface for inoculation, feeding and harvesting. During inoculation and feeding, a certain concentration of photosynthetic organisms or culture fluid can be pumped into the soft tubular reactor through the pipeline, or directly poured along the inner wall of the columnar hard elbow, and finally the pipeline or inner wall is rinsed clean with clean water. During harvesting, the pipeline is inserted into the culture fluid, and it is pumped into the harvesting device by a pump for harvesting, and the harvested breeding residual liquid is pumped back to the soft tubular reactor by a pump for continued breeding.

[0028] In the present invention, the soft tubular reactor floats on the water surface and is stirred by the fluctuation of the water surface, and does not need to be stirred by other machines, thereby greatly saving energy consumption. Since no additional stirring device is required, the design of the internal components of the reactants is simplified, which is more conducive to the disassembly and replacement of the soft tubular reactor.

[0029] The soft tubular reactor is connected to a fixing part, which only fixes the position of the soft tubular reactor in the water surface, so as to expose the soft tubular reactor to light and enable the photosynthetic organisms to obtain as much light as possible. The soft tubular reactor is not restricted from shaking with the fluctuation of the water surface, and the stirring effect of the water surface fluctuation on the photosynthetic organisms will not be affected by the fixing part.

[0030] The fixing part may be a fixing column 8, a fixing net, a fixing fence, or a combination of several fixing methods, which is used to fix the position of the soft tubular reactor in the water, and the position of the soft tubular reactor can be adjusted according to the water surface position to avoid the growth of photosynthetic organisms being affected by the water surface blocking. The fixing column 8 has one end fixed to the bottom of the water and the other end located on the water surface. The soft tubular reactor is connected to the fixing column through fixing rings 9 on the soft tubular reactor on both sides, and the position of the fixing rings 9 on the soft tubular reactor on the fixing column can be adjusted according to the water surface position, such as Figure 2 As shown. The fixed net is a mesh support fixed at a suitable position below the water surface. The soft tubular reactor is directly placed on the fixed net. One or more soft tubular reactors can be placed on the fixed net. If multiple soft tubular reactors are placed, each soft tubular reactor is separated from each other by the isolation belt on the fixed net to avoid mutual squeezing between the soft tubular reactors. The fixed net is connected to the support fixed to the bottom of the water through four sides, and a support point can be set in the middle of the fixed net if necessary. The position of the fixed net can be adjusted according to the changes in the water surface. The fixed fence is a fence formed by fixing the two ends to the bottom of the water, and the fixing rings 9 on the soft tubular reactors on both sides of the soft tubular reactor are fixed on the fence. The fixed fence can also be a plurality of frames connected in parallel, and the soft tubular reactors can also be a plurality of frames connected in parallel, and the connected parts are placed on the frame. The position of the soft tubular reactor in the water body is adjusted by adjusting the position of the frame.

[0031] In the present invention, sunlight is used to culture photosynthetic organisms. Some photosynthetic organisms, such as microalgae, are easy to adhere to the wall during the culture process, that is, the microalgae adhere to the inner wall of the culture device. If the microalgae adhere to the inner wall of the culture device that receives light, it will affect the reception of light, reduce the utilization rate of light energy and photosynthetic efficiency of the microalgae, and reduce the productivity of the microalgae. Therefore, when using a soft tubular reactor to culture microalgae, the soft tubular reactor is air, ensuring that a certain distance is maintained between the culture solution and the surface of the inner wall of the reactant that receives light, on the one hand, utilizing the photosynthetic organisms for ventilation, and on the other hand, preventing shading.

[0032] In the present invention, in order to further avoid the soft tubular reactor from blocking the light, a cleaning device and a spraying device are designed to extend the service life of the soft tubular reactor to the greatest extent. In addition, it should be understood by those skilled in the art that at least the upper part of the soft tubular reactor that receives light should be transparent.

[0033] The cleaning device 4 is fixed in the hard cylindrical elbow, and is made of a brush or sponge or other materials that can play the role of cleaning the inner wall of the soft reactant. It is fixed to the upper part of the soft tubular reactor through the cleaning device fixed shaft 3, and the cleaning device is pulled back and forth in the soft tubular reactor by pulling the rope 2. The shape of the cleaning device is arc-shaped, and the arc preferably only covers the light-transmitting part of the soft tubular reactor. When not in use, it is fixed to one side of the hard cylindrical elbow, and runs back and forth by pulling the rope 2 when in use. The pulling rope on the fixed shaft at the other end of the cleaning device 4 is easy to disassemble, which is convenient for the disassembly of the soft tubular reactor. The function of the cleaning device is to clean the light-transmitting part of the inner wall of the soft tubular reactor, mainly to clean the water vapor and splashed algae liquid on the light-transmitting part, and reduce the obstruction of light. The cleaning device is equipped with an automatic control device, which can clean the inner wall of the soft tubular reactor regularly every day, and can also be cleaned at any time according to the pollution of the inner wall.

[0034] The spray devices are distributed on both sides or around the soft tubular reactor to clean the dust, water stains and other pollutants that block light on the outer surface of the soft tubular reactor. The soft tubular reactor is sprayed with water regularly every day to prevent dust, water stains and other substances from adhering to the outer surface of the soft tubular reactor and extend the service life of the soft tubular reactor.

[0035] In the present invention, photosynthetic organisms include microalgae and photosynthetic bacteria. There is no particular limitation on the type of microalgae. Microalgae with high protein content or oil production are preferred, and engineered microalgae with greater industrial utilization value are more preferred. For example, the microalgae can be selected from easily harvested filamentous algae or spiral algae, or one of Chlorella, Scenedesmus, Chrysophyte and Phaeodactylum triangularis can be selected.

[0036] In the present invention, there is no special requirement for the conditions for culturing photosynthetic organisms, and the conditions commonly used in the art can be adopted, for example, including: a temperature of 15-45° C. and a light intensity of 1000-200000 lux.

[0037] In addition, in order to better observe the culture conditions and the growth status of photosynthetic organisms, according to actual needs, one or more of the various instruments for observing the culture conditions and the growth status of photosynthetic organisms that can be thought of by technical personnel in this field can be provided in the culture device, such as a dissolved oxygen detector, a pH detector, a temperature detector, a light intensity detector, a photosynthetic organism concentration detector, etc., to facilitate real-time observation and monitoring of various parameters.

[0038] For the culture medium, the culture medium commonly used in the art can be used according to the photosynthetic organisms to be cultured. For example, when culturing microalgae, Zarrouk or BG11 culture medium can be used, which can provide the nutrients such as nitrogen, phosphorus, potassium, etc. required for the growth of microalgae.

[0039] Example

[0040] The following examples will further illustrate the present invention, but are not intended to limit the present invention.

[0041] Spirulina was purchased from the Institute of Hydrobiology, Chinese Academy of Sciences.

[0042] The culture medium was Zarrouk.

[0043] OD value: The absorbance of the culture solution containing microalgae is measured at a wavelength of 560nm using a spectrophotometer with distilled water as a control.

[0044] This example is used to illustrate the method for culturing photosynthetic organisms of the present invention.

[0045] Use Figure 1 and Figure 2 The photosynthetic biological culture device shown is used to culture Spirulina. Zarrouk culture medium is used, and the temperature is controlled between 20-30℃. The initial concentration of algae species OD560 is 0.3, and 2% (v / v) CO2 is introduced for ventilation culture. An appropriate amount of Spirulina is poured into the prepared Zarrouk culture medium, and then pumped into the soft tubular reactor with a pump. The culture liquid volume is 80L, and the light-receiving area accounts for about one-third of the entire area of ​​the soft tubular reactor. The cleaning device moves back and forth once every 1 hour during the day. The OD560 value of the algae liquid is tested every day, and it is harvested after 15 days of continuous culture. Its growth curve is shown in Figure 3 The initial concentration was 0.3. In the first two days of the culture period, the OD560 value of Spirulina increased slowly. During the 2-5 days of the culture period, the OD560 value of Spirulina increased rapidly to 1.2. After 10 days of culture, the OD560 value of Spirulina reached about 1.8. After 15 days of continuous culture, the algae solution concentration OD560 was 1.9 at the time of harvest.

[0046] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0047] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0048] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method suitable for cultivating photosynthetic organisms on water surfaces; characterized in that: The method comprises cultivating photosynthetic organisms in a photosynthetic organism cultivation device under conditions for cultivating photosynthetic organisms. The cultivation device comprises a photosynthetic organism cultivation area floating on a liquid surface, a fixing portion, a columnar hard body elbow (7) and a cleaning device. The photosynthetic organism cultivation area is composed of a soft tubular reactor (6). Both ends of the soft tubular reactor (6) are respectively connected to the columnar hard body elbow (7). The soft tubular reactor (6) floats on the water surface through the fixing portion. The photosynthetic organisms are inoculated, harvested and supplemented with nutrients required for cultivation through the columnar hard body elbow (7). The cleaning device (4) is located on one side of the columnar hard body elbow (7).

2. A method for cultivating photosynthetic organisms on water surfaces according to claim 1, characterized in that: The conditions for culturing photosynthetic organisms include: temperature of 10-45°C and light intensity of 1000-200000 lux.

3. A method for cultivating photosynthetic organisms on water surface according to claim 1, characterized in that: The photosynthetic organism breeding area includes a light-transmitting part made of a light-transmitting material, and a soft tubular reactor (6) floating on the water surface.

4. A method for cultivating photosynthetic organisms on water surface according to claim 3, characterized in that: In the photosynthetic organism breeding area, air is above the breeding liquid, and at least one air supply pipeline (1) is provided below the breeding liquid. The gas supplied by the air supply pipeline (1) is air, gas rich in CO2, and other gases required for the growth of photosynthetic organisms.

5. The method for cultivating photosynthetic organisms on water surface according to claim 1, characterized in that: The columnar hard elbow (7) is an L-shaped hollow columnar elbow. The columnar hard elbow (7) is fixed to the bottom of the water. One end of the columnar hard elbow (7) is open and located above the water surface. The other end is connected to the soft tubular reactor (6). After the culture is completed, the culture fluid is pumped into a harvesting device through the columnar hard elbow (7) under the drive of a pump for harvesting. The harvested culture residual fluid is then returned to the reactor for continued culture.

6. A method for cultivating photosynthetic organisms on water surface according to claim 5, characterized in that: One end of the columnar hard elbow (7) is connected to the soft tubular reactor (6), the soft tubular reactor (6) is sleeved on the outside of the columnar hard elbow (7), and the soft tubular reactor (6) and the columnar hard elbow (7) are snap-fitted and connected.

7. A method for cultivating photosynthetic organisms on water surface according to claim 6, characterized in that: The soft tubular reactor (6) is connected to a fixing part, which is composed of one or more of a fixing column (8), a fixing net and a fixing fence. The fixing part is used to fix the soft tubular reactor (6) and adjust the height of the soft tubular reactor (6).

8. The method for cultivating photosynthetic organisms on water surface according to claim 3, characterized in that: A spray device is provided on the side wall of the soft tubular reactor (6).

9. A method for cultivating photosynthetic organisms on water surface according to claim 1, characterized in that: The cleaning device (4) is located on one side of the columnar hard body elbow (7), and pulling ropes are connected to both ends of the cleaning device (4). The cleaning device (4) is in an arc shape.

10. The method for cultivating photosynthetic organisms on water surface according to claim 1, characterized in that: Photosynthetic organisms include microalgae and photosynthetic bacteria, and microalgae include filamentous algae and spiral algae.

Images