WO2003006629A1 - Culturing method and device for photosynthetic microbes - Google Patents

Abstract

A culturing method for photosynthetic microbes characterized by culturing photosynthetic microbes by suspending photosynthetic microbes in an organic matter-dissolved liquid in growing photosynthetic microbes such as fine algae and photosynthetic bacteria, in daytime, irradiating the suspension (s) of the photosynthetic microbes with sun rays in a flat pond (p) opened to the atmosphere and having a large gas-liquid contact area, and at night, transferring the suspension (s) to a deep aeration tank (a) having a small gas-liquid contact area and aerating the suspension (s) in the aeration tank (a) with oxygen-containing gas such as air, or transferring the suspension (s) to a deep aeration tank (a) having a small gas-liquid contact area and providing a period of aerating the suspension (s) in the aeration tank (a) with oxygen-containing gas such as air and a period of stopping aeration to keep the suspension (s) in an anaerobic state; and a system associated with this method.

Description

 Detail

Method and apparatus for culturing photosynthetic microorganisms

Industrial applications

The present invention relates to a method and an apparatus for culturing photosynthetic microorganisms such as pearl oysters and photosynthetic bacteria. The present invention can be used for purification of organic wastewater in addition to the production of algal cells described above.

Conventional technology

 In general, photosynthetic microorganisms are cultivated on a large scale, such as edible cucumber cultivation ponds using acetic acid / glucose as a carbon source and high-rate oxidation ponds for organic sewage purification, as seen in microalgae cultivation. It is carried out in a shallow and wide flat pond p with a depth of about 2 Ocm, constructed outdoors. These are all open-top culture devices that receive sunlight directly on the water surface. For this reason,

(1) In a cold region, the heat loss from the vast water surface is large, especially at night, and the photosynthetic microorganism suspension is cooled and the growth rate is reduced.

(2) When the water temperature rises to about 10 or more, the growth of small animals such as daphnids and maggots, which prey on photosynthetic microorganisms, becomes active. There are many. Since the microanimals are carried by wind, birds, insects, etc., it is difficult to prevent invasion into the culture pond and its propagation. To prevent this mass outbreak, a large amount of chemicals must be used. Can't get _a

 (3) Rainfall dilutes the suspension of photosynthetic microorganisms, reducing the filtration rate of photosynthetic microorganisms. Furthermore, the photosynthetic microorganism suspension is washed away from the culture pond. In order to prevent this loss, it is necessary to raise the side wall of the cultivation pond more than necessary, and a transparent film roof is necessary even in a warm region where a greenhouse is not required.

There were problems such as.

If these are solved, food production, wastewater treatment, carbon dioxide fixation, etc. by photosynthetic microorganisms such as photosynthetic bacteria and microalgae will greatly advance. like this From this point of view, the inventor of the present invention filed Japanese Patent Application No. 4-282146 (Photo-synthetic microorganism culturing apparatus and its operation method) on September 8, 1994, and filed Japanese Patent Application No. 282146 (Microalgae cultivation device) was devised and filed.

 As a result, the problem of (1) was improved, more efficient cultivation of photosynthetic microorganisms became possible, and the disadvantage that the site area became large was also improved. In addition, the problem of (2) was solved, and stable continuous culture of photosynthetic microorganisms became possible.

 However, the problem (1) has not been completely solved.

 When culturing photosynthetic microorganisms, especially for wastewater treatment, the problem (1) is an obstacle to the establishment of facilities. Wastewater treatment requires a certain level of capacity every day. When culturing photosynthetic microorganisms with sunlight, their growth depends greatly on weather conditions such as solar radiation and temperature. Since the growth of photosynthetic microorganisms decreases most in winter, the scale of culture is set based on this winter growth. For this reason, a vast area of the site is still needed.

 In addition, due to the problem (3), the construction cost of the culture facility is high. Problems to be solved by the invention

 Accordingly, the present invention provides a method and an apparatus for culturing photosynthetic microorganisms, which can prevent the suspension from cooling in a cold region and can provide a certain excellent culturing result without being influenced by the weather conditions such as sunshine. It is intended to provide.

Means to solve the problem

 Photosynthetic microorganisms such as microalgae, red sulfur-free bacteria,

 (A) Ability to absorb solar energy and use this energy to absorb, degrade and proliferate carbon dioxide, organic matter and other nutrients. (B) In the process of catabolizing and metabolizing the absorbed organic matter (fermentation, respiration). Ability to breed using generated energy

 Having.

At night, when sunlight is removed, photosynthetic microorganisms proliferate using only the energy generated during the process of catabolizing and metabolizing organic matter (fermentation, respiration). The technology of Japanese Patent Application No. 4-282146 (culturing device for photosynthetic microorganisms and its operating method) and the technology of Japanese Patent Application No. 8-282146 (microalgae culturing device) are as follows. Stored this suspension in an upper sealed container, and enabled the control of predators by keeping the liquid warm and creating anaerobic and clean conditions. After that, while trying to disseminate the above-mentioned equipment, we came across the above-mentioned site problem and repeated research to further improve this problem. Finally, it was described in Japanese Patent Application Nos. 4-282146 and 8-282146. It is devised to add a technical content that demonstrates the characteristics of (B) to the technology, and proposes it as a new technology. It also solves the problems caused by rainfall.

That is, the present invention

First, in a method of growing photosynthetic microorganisms such as microalgae and photosynthetic bacteria, the photosynthetic microorganisms are suspended in a liquid in which organic matter is dissolved.

 In the daytime, the suspension s of the photosynthetic microorganisms is irradiated with sunlight in a shallow flat pond p slightly open to the gas-liquid contact surface opened to the atmosphere.

 At night, the suspension s is transferred to a deep aeration tank a with a small gas-liquid contact area, and the suspension s in the aeration tank a is aerated with oxygen-containing gas such as air.

 A method for culturing a photosynthetic microorganism, which comprises culturing the photosynthetic microorganism,

Second, in a method of growing photosynthetic microorganisms such as microalgae and photosynthetic bacteria, the photosynthetic microorganisms are suspended in a solution in which organic matter is dissolved.

 During the daytime, the suspension S of the photosynthetic microorganisms is irradiated with sunlight in a shallow ^ -plane pond p, which has a large gas-liquid contact area opened to the atmosphere.

 At night, the suspension s is transferred to a deep aeration tank a with a small gas-liquid contact area, and the suspension s in the aeration tank a is aerated with oxygen-containing gas such as air.

 During the daytime and during rainfall, the suspension s is transferred to the deep aeration tank a with a small gas-liquid contact area, the suspension s in the aeration tank a is aerated with oxygen-containing gas such as air, and flows into the flat pond p. This is a method for culturing photosynthetic microorganisms, which comprises discharging rainwater out of a flat pond p and culturing photosynthetic microorganisms.

Third, the method of growing photosynthetic microorganisms such as microalgae and photosynthetic bacteria In the daytime, the photosynthetic microorganisms are suspended in the liquid in which the organic matter is dissolved. In the daytime, the suspension S of the photosynthetic microorganisms is placed in the shallow flat pond P, which is open to the atmosphere and has a large gas-liquid contact area. Irradiate light,

 At night, the suspension S is transferred to a deep aeration tank with a small gas-liquid contact area, and the suspension s in the aeration tank is aerated with oxygen-containing gas such as air, and the aeration is stopped and suspended. With a period to make the suspension s anaerobic,

A method for culturing a photosynthetic microorganism, which comprises culturing the photosynthetic microorganism,

Fourth, in a method of growing photosynthetic microorganisms such as microalgae and photosynthetic bacteria, the photosynthetic microorganisms are suspended in a liquid in which organic matter is dissolved.

 In the daytime, the suspension s of the photosynthetic microorganisms is irradiated with sunlight in a shallow flat pond p having a large gas-liquid contact area opened to the atmosphere,

 During the night, the suspension s is transferred to a deep aeration tank with a small gas-liquid contact area, and the suspension s in the aeration tank is aerated with air, and the aeration is stopped and the anaerobic state is stopped. To cultivate photosynthetic microorganisms,

 In the daytime, during rainfall, the suspension s is transferred to the aeration tank, and the suspension s in the aeration tank 內 is aerated with oxygen-containing gas such as air to culture photosynthetic microorganisms. P is a method for cultivating photosynthetic microorganisms, which is characterized by culturing the photosynthetic microorganisms to the outside,

Fifth, in an apparatus for culturing photosynthetic microorganisms such as microalgae and photosynthetic bacteria in a solution in which organic matter is dissolved,

 A shallow flat pond open to the atmosphere and having a large gas-liquid contact area for irradiating sunlight to the photosynthetic microorganisms in the liquid in which the organic matter is dissolved and allowing the photosynthetic microorganisms to proliferate;

 A deep aeration tank having a small gas-liquid contact area, which is filled with a liquid containing the photosynthetic microorganisms, aerated with an oxygen-containing gas, and provided with an aerator for growing the photosynthetic microorganisms.

And a liquid transfer mechanism m for transferring liquid between the flat pond p and the aeration tank a. Sixth, in a device for culturing photosynthetic microorganisms such as microalgae and photosynthetic bacteria in a solution in which organic matter is dissolved,

 A shallow flat pond open to the atmosphere and having a large gas-liquid contact area for irradiating sunlight to the photosynthetic microorganisms in the liquid in which the organic matter is dissolved and allowing the photosynthetic microorganisms to proliferate;

 A liquid filled with the photosynthetic microorganisms, aerated with an oxygen-containing gas, provided with an aerator for growing the photosynthetic microorganisms, and a deep upper sealed aeration tank bl provided with a pipe for deaeration and an on-off valve.

 And the liquid transfer mechanism for transferring liquid between the flat pond P and the upper closed aeration tank b l

A culture device for photosynthetic microorganisms, comprising:

Seventh, in an apparatus for culturing photosynthetic microorganisms such as microalgae and photosynthetic bacteria in a solution in which organic matter is dissolved,

 A shallow flat pond open to the atmosphere and having a large gas-liquid contact area for irradiating sunlight to the photosynthetic microorganisms in the liquid in which the organic matter is dissolved and allowing the photosynthetic microorganisms to proliferate;

 A deep aeration tank with a floating lid b2 which is filled with a liquid containing the photosynthetic microorganisms, and is provided with an aerator for aerating an oxygen-containing gas to grow the photosynthetic microorganisms and a floating body covering the liquid surface.

 And a liquid transfer mechanism for transferring liquid between the flat pond p and the floating aeration tank b 2

An apparatus for culturing photosynthetic microorganisms, comprising: As described above, the present invention allows daytime breeding using solar energy to be performed in a shallow flat pond p, and breeding using energy by nighttime oxygen respiration without sunlight in a deep aeration tank with high oxygen dissolving efficiency. This is a method and an apparatus for forming a field suitable for each metabolism.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a plan view showing one embodiment of the present invention.

Fig. 2 is a vertical cross-sectional view taken along the line A-A in Fig. 1, showing the state during daytime operation. ing.

FIG. 3 is a vertical cross-sectional view taken along the line AA in FIG. 1 and shows a state during nighttime aeration.

FIG. 4 is a plan view showing another embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view taken along line BB in FIG. 4, and shows a state during daytime operation.

FIG. 6 is a vertical cross-sectional view taken along the line BB in FIG. 4, and shows a state during the night aeration operation.

FIG. 7 is a vertical cross-sectional view taken along the line BB in FIG. 4, and shows a state in which night aeration is stopped.

FIG. 8 is a plan view showing an embodiment of the plane pond p.

FIG. 9 is a plan view showing an embodiment of the plane pond p.

FIG. 10 is a plan view showing an embodiment of the plane pond p.

FIG. 11 is a longitudinal sectional view showing another embodiment, which corresponds to FIG. 5 of the embodiment shown in FIGS. 4 to 7 and shows a state during operation in the daytime. FIG. 12 is a vertical cross-sectional view of the same device as FIG. 11, and corresponds to FIG. 6, and shows a state during night aeration.

FIG. 13 is a longitudinal sectional view of the same device as FIG. 11, and corresponds to FIG. 7, and shows a state in which night aeration is stopped.

FIG. 14 is a plan view showing another embodiment.

Fig. 15 is a vertical sectional view taken along the line DD in Fig. 14, showing the state during daytime operation.

FIG. 16 is a vertical cross-sectional view taken along the line DD in FIG. 14, and shows a state during operation in the daytime.

FIG. 17 is a plan view showing another embodiment.

FIG. 18 is a longitudinal sectional view taken along the line E--E in FIG. 17, and shows a state during operation in the daytime.

FIG. 19 is a longitudinal sectional view taken along the line EE in FIG. 17 and shows a state during daytime operation. FIG. 20 is a plan view showing another embodiment. Corresponds to Figure 14.

FIG. 21 is a plan view showing another embodiment. Corresponds to FIG.

FIG. 22 is a plan view showing another embodiment.

FIG. 23 is a vertical sectional view of F—: F in FIG. 22, showing a state during daytime operation.

FIG. 24 is a cross-sectional view taken along the line HH in FIG. 23, and shows a state during daytime operation.

Fig. 25 is a vertical sectional view taken along the line GG in Fig. 22, showing the state during daytime operation.

FIG. 26 is a vertical sectional view taken along the line II in FIG. 22, and shows a state during nighttime aeration.

FIG. 27 is a plan view showing one embodiment of the present invention.

FIG. 28 is a vertical sectional view taken along the line JJ in FIG. 27, and shows a state during operation during daytime.

Fig. 29 is a vertical sectional view taken along the line JJ in Fig. 27, showing the state during the night aeration operation.

Shin's explanation

 a is an aeration tank, p is a flat pond, bl is a closed aeration tank in the capital, b 2 is an aeration tank with a floating lid, e is a residual liquid discharge pipe, f is a rainwater discharge pipe, ¾ is a bubble, k is an air layer, m Is a liquid transfer mechanism, s is a suspension, t is a liquid level, 2 is a valve, 3 is a diffuser, 4 is a flow control valve, δ is a blower, 6 is a pump, 7 is a valve, 8 is a pipe, 9 Is a pipe, 1CM pipe, 11 is a valve, 13 is a valve,

 14 is a pipe, 15 is a valve, 16 is a stirring rotor, 17 is a rectifying wall, 18 is a pipe, 19 is a pump, 20 is a stirring device, 21 is a bogie, 22 is a center rotating part, 24 is a water pipe, and 25 is a water pipe. A diffuser, 27 is a return pipe, 28 is a rectifying wall, 29 is a spout water pipe, 30 is a suction water pipe, 31 is a suction water pipe, 33 is a rectifying wall, 37 is a rectifying wall, 38 is a floating body, 39 is the support

Dashed arrows indicate the flow direction of the suspension.

Examples and actions 1 to 3 are views showing an embodiment of the present invention. Fig. 1 is a plan view, Fig. 2 is an A-A longitudinal section during daytime operation, and Fig. 3 is an A-A longitudinal section during night operation. This embodiment is particularly useful for cultures that do not require the suppression of the growth of predators, ie, culture of photosynthetic bacteria under conditions of high organic matter, batch culture of microalga such as chlorella (harvested before the occurrence of insects), insecticides This shows the case of 培養 such as addition culture.

The system consists of a shallow flat pond p that receives sunlight and a deep aeration tank a with a small gas-liquid contact area. A diffuser 3 is provided at the bottom of the aeration tank a. Pump 6 and pipe 8 for sending a liquid in which photosynthetic microorganisms are suspended in a nutrient solution containing organic matter (hereinafter referred to as suspension _S ) from aeration tank a to plane pond p, and from plane pond p to aeration tank a The liquid transfer mechanism m is constituted by the tube 9 for sending the suspension s. Plane pond The bottom of p is set low toward the pipe 9 installation site. Near the pipe 9, a residual liquid discharge pipe e and a rainwater discharge pipe f are provided.

 In the daytime (Fig. 2), the suspension s is filled in the flat pond p and exposed to sunlight. The photosynthetic microorganisms in the liquid absorb light and use this energy to absorb and degrade organic matter and proliferate. At night (Figure 3), valve 7 is opened and suspension s is allowed to flow down to aeration tank a via line .9. Suspension that fills aeration tank a remains in flat pond P. This residual liquid is discharged to a storage tank or the like (not shown) via the residual liquid discharge pipe e by opening the valve 2. Next, air is passed through the suspension s filled in the aeration tank a through the flow control valve 4, the pipe 10, and the air diffuser 3 by the purer 5 (g indicates bubbles), and oxygen Supply. Light and synthetic microorganisms decompose, degrade, and multiply organic matter by respiration using oxygen. In the daytime (Fig. 2), the blower 5 is stopped, the valve 7 is closed, and the pump 6 sends the suspension to the flat pond p via the pipe 8 and fills the suspension with the flat pond p. Subject to light irradiation. Thereafter, the above steps are repeated to perform the culture.

During daytime rainfall, the valve 7 is opened, and the suspension s flows down to the aeration tank a via the pipe 9. Next, flow into the suspension s filled in the a. : Air is supplied through control valve 4, pipe 10, and diffuser 3 (g indicates air bubbles), and oxygen is supplied. Photosynthetic microorganisms use this oxygen to breathe It decomposes, degrades, and proliferates organic matter. The rainwater flowing into the flat pond P is opened to the drainage channel (not shown) via the rainwater discharge pipe f by opening the valve 11.

 With the exception of pure culture in the laboratory, large-scale outdoor cultures always contain contamination with non-photosynthetic microorganisms. The water depth of the flat pond p is appropriate to be less than 20 cm to preferentially grow photosynthetic microorganisms. At depths above 20 cm, the depth of the photosynthetic microorganisms decreases, making it difficult to grow preferentially.

At night or during rainfall, it is possible to ventilate the flat pond _p and supply oxygen to allow photosynthetic microorganisms to grow by respiratory metabolism as described above.However, since the flat pond P is shallow, oxygen supply per unit power Performance is extremely low and is not practically feasible in terms of cost. In the present invention, since the suspension s is guided to the deep aeration tank a where the suspension s is aerated, the oxygen supply capacity per unit power is high and the suspension s can be practically implemented. In a conventional activated sludge aeration tank, an oxygen dissolution efficiency of 6-8% can be obtained at an aeration water depth of 3-4m. The water depth of the aeration tank a of the present invention may be set to 2.5-4 m.

 As described above, according to the present invention, it is possible to increase the amount of proliferation per unit area by efficiently growing photosynthetic microorganisms even at night or during rainfall.

 4 to 7 show another embodiment of the present invention (a side view. FIG. 4 is a plan view, FIG. 5 is a vertical sectional view taken along the line BB during daytime operation, and FIG. Fig. 7 is a vertical sectional view taken along the line B-B while the aeration is stopped during night operation, and this embodiment is particularly applicable to cultures that require suppression of the growth of predators, that is, insecticides. This device shows the case of continuous cultivation of photosynthetic microorganisms with no addition.This equipment has a point that the aeration tank is configured as an upper closed aeration tank bl, and is equipped with a pipe 14 for taking in and out air and a valve 15. This is similar to the device shown in FIGS.

In the daytime (Fig. 5), the suspension is a flat pond! ) And receive sunlight irradiation. The photosynthetic microorganisms in the liquid absorb light and use this energy to absorb and degrade organic matter and proliferate. At night (Figure 6), valves 7 and 15 are opened, The suspension flows down via pipe 9 into the upper closed aeration tank bl. Suspension s that fills upper closed aeration tank b 1 remains in flat pond p. In the residual liquid remaining in the flat pond p, the residual liquid is in contact with air, so that photosynthetic microorganisms such as insects can survive and grow. In order to avoid this, the residual liquid is discharged as a harvest into a storage tank or the like (not shown) through the residual liquid discharge pipe e by opening the valve 2. Next, air is supplied to the suspension filled in the upper closed aeration tank bl through the flow control valve 4, the pipe 10, and the air diffuser 3 by the blower 5 to supply oxygen. The photosynthetic microorganisms decompose, degrade, and multiply organic matter by respiration using this oxygen. After that (Fig. 7), blower 5 is stopped, and valves 7, 13 and 15 are closed. The oxygen in the upper closed aeration tank b is gradually consumed and becomes anaerobic. Under anaerobic conditions, predators such as worms gradually die. The photosynthetic microorganism is alive for about 1 to 23 days.

 It has been experimentally shown that ヮ worms can be killed in half under anaerobic conditions in about 6 hours, and all in about 12 hours, and return to their original state when a half of them are aerated for 48 hours. It is appropriate to stop the aeration at night for 8 hours or more.

 During the daytime (Fig. 5), the blower 5 is stopped, the valve 7 is closed, the valves 13 and 15 are opened, and the suspension is sent by the pump 6 through the pipe 8 to the flat pond p. Fill the suspension pond p with the suspended liquid and irradiate it with sunlight. Thereafter, the above steps are repeated to perform the culture.

 During daytime rainfall, the suspended liquid s filled in the aeration tank a. Is aerated as in the case of the nighttime above, and the rainwater flowing into the flat pond p is discharged to drainage channels (not shown). Discharge.

 In order to prevent the night suspension s from remaining in the flat pond p, the bottom of the pond p is set low toward the pipe 9 installation site, and a residual liquid discharge pipe e is provided near the pipe 9. This is not an essential condition, and the p-bottom of the flat pond may be almost horizontal. If it is almost horizontal, the suspension s does not turn yellow and continuous culturing is not possible.

As described above, according to the method and apparatus of the present invention, even at night or during daytime rainfall, By efficiently growing photosynthetic microorganisms, it is possible to increase the amount of growth per unit area and to suppress the growth of worms. By adding the same amount of nutrient solution, continuous culture is possible. In addition, when organic wastewater discharged daily is used as a nutrient solution, the yield of photosynthetic microorganisms increases, and this can be continuously and efficiently purified daily.

 In the present embodiment, the aeration is stopped at night after the aeration, and then the anaerobic state is achieved. However, the same effect can be obtained by performing the aeration after the order is reversed and the anaerobic state is maintained.

 The flat pond p shown in Fig. 1 to Fig. 7 does not have a specific stirring mechanism, but the flow when the suspension s is moved daily to the aeration tank a or the upper closed aeration tank bl. Harvest can be almost prevented. In addition, since the mixing with the added nutrient solution is performed in the aeration tank a or the upper closed aeration tank b1, the concentration of nutrients in the flat pond P is also prevented from becoming uneven. However, a stirrer is needed to speed up breeding.

 Examples of the plane pond p are shown in plan views in FIGS. Each is a shallow flat pond with a depth of 10-40 cm. In the flat pond p in Fig. 8, a stirring rotor 16 for flowing the suspension s in the direction of the arrow is provided in one endless water channel defined by the rectifying wall 17, and a stirring mechanism is configured. . The flat pond p in Fig. 9 is obtained by sending the suspension s via the pipe 18 by the pump 19 from the downstream end to the upstream end of one waterway defined by the rectifying wall 17-.. H, The suspension s is caused to flow in the direction of the arrow to form a stirring mechanism. Fig. 10 shows that a stirrer 20 with a brush is provided from the center rotating part 22 of the circular flat pond p to the bogie 21 on the upper end of the circumferential side wall, and the bogie 21 is moved in the direction of the arrow. And stir the pond.

 The plane pond p having the stirring mechanism shown in FIGS. 8 to 10 can be used also in the present invention because of the power required to increase the operating cost of the facility by the amount of the stirring device.

FIGS. 11 to 13 show another embodiment, and correspond to the embodiments shown in FIGS. 4 to 7. FIG. Fig. 11, which corresponds to Fig. 5, is a daytime crop. A longitudinal sectional view during operation, FIG. 12 corresponding to FIG. 6 is a longitudinal sectional view during night aeration operation, and FIG. 13 corresponding to FIG. 7 is a longitudinal sectional view during night aeration stop. The difference from the embodiment shown in FIGS. 4 to 7 is that the pipe 9 opens at the bottom of the upper sealed aeration tank b1.

 During the daytime (Fig. 11), with the valve 15 closed and the valve 7 open, air is sent from the air diffuser 3 through the pipe 10 by the blower 5. The suspension s is extruded through a pipe 9 into a flat pond p. Thereafter, the valve 7 is closed, the blower 5 is stopped, and the suspension s is filled in the flat pond p and is irradiated with sunlight to allow the photosynthetic microorganisms to grow. At night (Fig. 12), the valve 7 and the valve 15 are opened, and the suspension s is allowed to flow through the pipe 9 into the upper closed aeration tank b1. Next, air is supplied to the suspension s filled in the upper closed aeration tank b 1 through the flow control valve 4, the pipe 10, and the air diffuser 3 by the blower 5 to supply oxygen. The photosynthetic microorganisms decompose, degrade, and proliferate organic substances by respiration using oxygen. Thereafter (Fig. 13), the blower 5 is stopped, the valve 7, the flow control valve 4 and the valve 15 are closed, and the suspension s in the upper sealed aeration tank b is made anaerobic. During the daytime (Fig. 11), the valves 7 and 4 are opened, the blower 5 is operated, and the suspension is sent to the flat pond p. Thereafter, the above steps are repeated to perform the culture. Other operations such as rain during the day are performed in the same manner as in the above-described embodiment.

 In this embodiment, the pump is not required, and the suspension s can be easily moved by the on-off of the blower 5.

14 to 16 are views showing still another embodiment. FIG. 14 is a plan view, and FIGS. 15 and 16 are vertical sectional views taken along the line DD during daytime operation. The difference from the embodiment shown in FIGS. 1 to 13 is that the upper sealed aeration tank b1 is provided below the center of the flat pond p, and the bottom of the flat pond p and the bottom of the upper sealed aeration tank b1 are connected by the water pipe 24. Has been contacted. In the daytime (Figs. 15 and 16), air is sent from the air diffuser 25 through the pipe 10 by the blower 5 with the valve 15 closed and the valve 4 open. The suspension s is pushed out to the flat pond p via the conduit. Then, the liquid level t in the upper closed aeration tank b descends and reaches the lower end of the water pipe 24. Further, the liquid surface descends due to the surface tension of the water, and the air k eventually flows into the water conduit 24. Gushing. Then, the suspension s in the headrace channel 24 rises with the air k and jets into the flat pond P (FIG. 15). When the jetting ends, the suspension s in the flat pond p descends in the headrace 24 and flows into the upper closed aeration tank bl (Fig. 16). By this series of operations, a wave is generated in the plane pond p, and the suspension s is stirred. The suspension s is irradiated with sunlight while being stirred, and the photosynthetic microorganisms proliferate. At night (not shown), the valve 15 is opened, and the turbid liquid s is allowed to flow down to the upper closed aeration tank bl via the water pipe 24. Next, the flow control valve 4 is opened, and air is supplied to the suspension s filled in the upper sealed aeration tank bl via the flow control valve 4, the pipe 10, and the air diffuser 25 by the blower 5. Ventilate and supply oxygen. The photosynthetic microorganisms decompose, degrade, and grow organic matter by respiration using this oxygen. Thereafter, the blower 5 is stopped, the flow control valve 4 and the valve 15 are closed, and the inside of the upper sealed aeration tank bl is made anaerobic. In the daytime, the valve 4 is opened, the blower 5 is operated, and the suspension is sent to the flat pond p. Thereafter, the above steps are repeated for culturing. Other operations such as rain during the day are performed in the same manner as in the above embodiment.

 In the present embodiment, the suspension can be easily moved by the on-off of the blower 5, and the suspension in the flat pond p can be easily stirred without newly installing a stirring device.

17 to 19 are diagrams showing still another embodiment. FIG. 17 is a plan view, FIG. 18 is a longitudinal sectional view of E-E during daytime operation, and FIG. 19 is a longitudinal sectional view of E-E during daytime operation. FIG. The difference from the embodiment shown in FIGS. 14 to 16 is that a return pipe 27 is provided to connect the end of the flat pond p and the bottom of the upper closed aeration tank bl. The return pipe 27 is provided so as to open below the lower end of the water pipe 24 in the upper closed aeration tank bl. In this embodiment, when the air flows out of the water pipe 24 to the flat pond p (FIG. 18), the suspension s flows into the upper closed aeration tank b1 promptly from the return pipe 27, Mixing of s is also possible. Other driving operations may be performed in the same manner as in the embodiment shown in FIGS. FIG. 20 is a plan view corresponding to FIG. 14 of the embodiment shown in FIGS. Plane pond p is composed of a long water channel and an upper closed aeration tank below its end. b 1 is provided. FIG. 21 is a plan view corresponding to FIG. 17 of the embodiment shown in FIGS. The flat pond p is composed of a long waterway, and an upper closed aeration tank bl is provided below its end. The return pipe 27 connects the end of the flat pond p and the bottom of the upper closed aeration tank b. The shape of the flat pond p is not limited to the above embodiment, but may be determined in consideration of various conditions such as the shape of the site and the budget for the facility.

 FIGS. 22 to 26 are views showing another embodiment of the present invention. FIG. 22 is a plan view, FIG. 23 is a longitudinal sectional view taken along the line FF during daytime operation, and FIG. G longitudinal section, Fig. 24 is H-H transverse section during daytime operation, and Fig. 26 is I-I longitudinal section during night aeration. This embodiment has the same function as the device shown in FIG. In the device shown in Fig. 21, the suspension s is configured to flow in the order of the water pipe 24 in the upper closed aeration tank b1, the channel-shaped flat pond p, the return pipe 27, and the upper closed aeration tank b. I have. Also in the apparatus of the present embodiment, the flat pond p is divided by the rectifying wall 28, and the upstream end and the downstream end are configured as one adjacent water channel on the upper closed aeration tank b. A water pipe 29, suction water pipes 30 and 31 are provided at the downstream end, and a suspension water pipe 29, a flat pond p, a suction water pipe 30 and 31 and an upper closed aeration tank bl in this order. It is configured to flow cyclically. 37 is a rectifying wall. In FIG. 21, it is expensive to provide the return pipe 27 corresponding to the flow product of the channel-shaped flat pond P. In the present embodiment, the flat pond p is divided by the rectifying wall 28, and the upstream end and the downstream end are formed as one adjacent water channel on the upper closed aeration tank b1, and the upstream end of the pond is used for jetting. Since the water supply pipe 29 and the suction water supply pipes 30 and 31 are provided at the downstream end, the cost is low, the flow in the flat pond P is good, and the mixing and stirring can be performed efficiently.

FIG. 27 to FIG. 29 are views showing still another embodiment, and correspond to the embodiment shown in FIG. 4 to FIG. Fig. 27 corresponding to Fig. 4 is a plan view, Fig. 28 corresponding to Fig. 5 is a J-J vertical cross-section during daytime operation, and Fig. 29 corresponding to Fig. 6 is a J-J vertical cross-section during night aeration operation. is there. The difference from the embodiment shown in FIGS. 4 to 7 is that the aeration tank is configured as an aeration tank b2 with a deep floating lid having a liquid surface and a floating body 38. In the daytime, the floating body 38 is the support 39 Rest on top. At night, the floating body 38 covers most of the liquid level and floats on the liquid level. When aeration is stopped at night, oxygen is supplied to the liquid level in the gap between the floating body 38 and the tank wall, etc., but the supply amount is small, and in the presence of organic substances, the oxygen in the aeration tank b2 with a floating lid is supplied. The suspension s is in an air state, the growth of small animals such as stink bugs is suppressed, and continuous culture of photosynthetic microorganisms is possible. As the floating body 38, a synthetic resin foam plate or the like may be used.

 In the case of the present embodiment, although the cost is lower than that of the upper sealed aeration tank b1, efficient movement and stirring of the suspension s by press-in of air as in the upper sealed aeration tank b1 cannot be performed. Also, during aeration, the impact is severe and the floating body 38 may be damaged. The device of this example is suitable for small-scale culture.

 The operation results of the method and apparatus of the present invention are as follows. (Example)

From February 6, 2001, batch culture of Chlorella sp. Was performed using the apparatus shown in FIGS. The flat pond p is made of a concrete block side wall water tank with an average water depth of 15.5 cm and a light receiving area of 3.6 m2 (2.0 m * 1.8 m), and the upper sealed aeration tank b1 is made of a PVC pipe ν υ φ500 (inner diameter of 490 mm). The depth was 3.05m and the water depth was 2.95m. A and B units were prepared. Pig urine and garbage leachate were mixed, water was added to the mixture, water was added to the supernatant that had been removed for one week, and water was added. Into the flat pond p, and the culture was started. A ventilated about 10 LZ for 8 hours from 4:30 pm to A from the upper closed aeration tank b 1 at a depth of 2.8 m. B does not ventilate. From 8:30 a.m. to 4:30 p.m., both A and B were cultivated in a flat pond p and then returned to the upper closed aeration tank bl. During the experiment, water was added to adjust the amount of water, and valve 15 was opened at night. The experiment was performed in Transparent Vinyl House II. At 4:30 pm, the average water temperature was All.5 and B at 11.0 ° C. The results of the culture are shown in the table below. Culture days A: Night aeration B: No night aeration PCV BOD (ppm) PCV BOD (ppm)

0 2.6 1980 2.6 1980

8 7.4 73 4.9 600 From the table, the effect of night aeration of the present invention is recognized.

Then, in April, the yellowish liquid, which produced pests, was added to the PCV5 suspension, and the mixture was added to the flat ponds Α and Β ', and the culture was resumed. A solenoid valve was used for the device of (1), and its opening and closing were performed automatically. The culture in A was carried out from 8:30 in the morning to 4:30 in the afternoon in a flat pond p, followed by aeration for 6 hours, followed by stopping the aeration for 10 hours and maintaining an anaerobic state. The cultivation in B was performed in a flat pond p throughout the day. During the period, the nutrient solution prepared as described above was appropriately added. On the 5th day after the start of the experiment, the flat pond p of B turned yellow, and a large number of devils were observed. In the device A, the dark green state continued for 2 months until the end of the experiment.

 The present invention can be used not only for cultivation of the above-mentioned cloaca, but also for cultivation of other photosynthetic microorganisms having a respiratory function (green algae, red non-sulfur bacteria, kaya algae, etc.). Needless to say, the present invention can also be used for purification of organic wastewater by these photosynthetic microorganisms.

The invention's effect

 As described above, the method and apparatus of the present invention

 First, daytime breeding using solar energy is performed in a shallow flat pond p, and breeding using nighttime oxygen respiration without sunlight is performed in a deep aeration tank with high oxygen dissolution efficiency. It is characterized by forming a field suitable for each metabolism, and can increase the growth rate of photosynthetic microorganisms by increasing the amount of aeration and the aeration time at night in winter when the temperature decreases.

Secondly, in Japanese Patent Application No. 8-282146 (Microalgae cultivation device), the upper closed tank only played a role of keeping the heat and suppressing the worms. This is characterized in that a period is set for the operation. This According to this, in addition to keeping warm and suppressing stink bugs, effective propagation at night becomes possible. That is, by increasing the amount of aeration and the aeration time at night in winter when the temperature decreases, the growth rate of photosynthetic microorganisms can be increased, and the occurrence of a large number of small animals such as insects can be prevented.

 Thirdly, during rainfall during the daytime, rainwater flowing into the flat pond p is drained, and the photosynthetic microorganisms are propagated in the aeration tank using energy from oxygen respiration. Because of i, it is possible to prevent the growth of the suspension during the period of lack of sunshine and dilution of the suspension due to rainfall. Transparent film sheds are not required in warm regions. In addition, there is no need to construct an excessively high side wall when no shed is provided.

 In summary, according to the present invention, it is possible to increase the cultivation speed during periods of insufficient sunshine and low temperatures, and to achieve almost constant cultivation and cultivation that is not affected by weather conditions throughout the year. This leads to a reduction in facility costs. In addition, mass production of small animals such as pests can be prevented, and efficient high-concentration continuous culture can be performed throughout the year.

Claims

The scope of the claims  Claims: 1. A method for growing photosynthetic microorganisms such as microalgae and photosynthetic bacteria, wherein the photosynthetic microorganisms are suspended in a liquid in which organic matter is dissolved.  In the daytime, the suspension s of the photosynthetic microorganisms is irradiated with sunlight in a shallow flat pond p open to the atmosphere and having a large gas-liquid contact area,  At night, the suspension s is transferred to a deep aeration tank a with a small gas-liquid contact area, and the suspension s in the aeration tank a is aerated with oxygen-containing gas such as air.  A method for culturing a photosynthetic microorganism, comprising culturing the photosynthetic microorganism. 2. A method for growing photosynthetic microorganisms such as microalgae and photosynthetic bacteria, wherein the photosynthetic microorganisms are suspended in a liquid in which organic substances are dissolved.  In the daytime, the suspension s of the photosynthetic microorganisms is irradiated with sunlight in a shallow flat pond p open to the atmosphere and having a large gas-liquid contact area,  At night, the suspension s is transferred to a deep aeration tank a having a small gas-liquid contact area, and the suspension s in the aeration tank a is aerated with oxygen-containing gas such as air.  During daytime rainfall, the suspension s is transferred to the deep aeration tank a with a small gas-liquid contact area, the suspension s in the aeration tank a is aerated with oxygen-containing gas such as air, and the rainwater flowing into the flat pond p Is a method for cultivating photosynthetic microorganisms, which is characterized by discharging photosynthetic microorganisms out of a flat pond.  3. A method for growing photosynthetic microorganisms such as microalgae and photosynthetic bacteria, wherein the photosynthetic microorganisms are suspended in a liquid in which organic substances are dissolved.  In the daytime, the suspension s of the photosynthetic microorganisms is irradiated with sunlight in a flat pond p having a large gas-liquid contact area opened to the atmosphere,  At night, the suspension s is transferred to a deep aeration tank having a small gas-liquid contact area, the suspension s in the aeration tank is aerated with oxygen-containing gas such as air, and the aeration is stopped to stop the suspension s. With a period of anaerobic A method for culturing a photosynthetic microorganism, comprising culturing the photosynthetic microorganism. 4. A method for growing photosynthetic microorganisms such as microalgae and photosynthetic bacteria, wherein the photosynthetic microorganisms are suspended in a liquid in which organic matter is dissolved. In the daytime, the flat pond p, which is open to the atmosphere and has a large gas-liquid contact area, is Then, the suspension s of the photosynthetic microorganisms is irradiated with sunlight, and at night, the suspension s is transferred to a deep aeration tank having a small gas-liquid contact area, and the suspension S in the aeration tank is A period for aerating the air and a period for stopping the aeration and bringing the suspension S into an anaerobic state are provided to culture the photosynthetic microorganisms, and at the time of daytime rainfall, the suspension _s is transferred to the aeration tank and the aeration is performed. A photosynthetic microorganism is cultured by aerating oxygen-containing gas such as air to the suspension s in the tank, and rainwater flowing into the flat pond p is discharged out of the flat pond P to culture the photosynthetic microorganism. A method for culturing photosynthetic microorganisms.  5. The aeration tank according to claim 3 or 4, wherein the aeration tank is provided with a pipe for deaeration and an on-off valve, and is an upper sealed aeration tank bl having an upper part sealed with a partition wall. A method for culturing photosynthetic microorganisms.  6. The method for culturing photosynthetic microorganisms according to claim 3, wherein the aeration tank is an aeration tank b2 with a floating lid provided with a floating body covering a liquid surface. .  7. An apparatus for culturing photosynthetic microorganisms such as microalgae and photosynthetic bacteria in a solution in which organic matter is dissolved,  A shallow flat pond open to the atmosphere and having a large gas-liquid contact area for irradiating sunlight to the photosynthetic microorganisms in the liquid in which the organic matter is dissolved, and allowing the photosynthetic microorganisms to proliferate;  A deep aeration tank with a small liquid-contact area, comprising an aerator for filling the liquid containing the photosynthetic microorganisms, aerating the oxygen-containing gas with the liquid, and growing the photosynthetic microorganisms.  And a liquid transfer mechanism m for moving a liquid between a flat pond p and an aeration tank a.  8. An apparatus for culturing photosynthetic microorganisms such as microalgae and photosynthetic bacteria in a solution in which organic matter is dissolved, A shallow flat pond open to the atmosphere and having a large gas-liquid contact area for irradiating sunlight to the photosynthetic microorganisms in the liquid in which the organic matter is dissolved, and allowing the photosynthetic microorganisms to proliferate; A liquid containing the photosynthetic microorganisms is filled, oxygen-containing gas is aerated there, an aerator for growing the photosynthetic microorganisms is provided, a pipe for deaeration and a deep upper sealed aeration tank bl  And a liquid transfer mechanism m for transferring a liquid between the flat pond p and the upper closed aeration tank b 1.  9. A water pipe connecting the bottom of the flat pond p and the bottom of the upper sealed aeration tank b1, the pipe and the on-off valve for deaeration, and the gas injection for injecting gas into the upper sealed aeration tank b1. 9. The culture apparatus for photosynthetic microorganisms according to claim 8, wherein the liquid transfer mechanism m is formed by a machine.  10. An apparatus for culturing photosynthetic microorganisms such as microalgae and photosynthetic bacteria in a solution in which organic matter is dissolved,  A shallow flat pond open to the atmosphere and having a large gas-liquid contact area for irradiating sunlight to the photosynthetic microorganisms in the liquid in which the organic matter is dissolved and allowing the photosynthetic microorganisms to proliferate;  An aeration tank for filling a liquid containing the photosynthetic microorganisms, aerating the oxygen-containing gas therewith to grow the photosynthetic microorganisms, and a floating body covering the liquid surface with a deep floating lid b 2.  And a liquid transfer mechanism m for transferring a liquid between the flat pond p and the aeration tank b2 with a floating lid.  11. The rainwater discharge pipe f for discharging rainwater flowing into the flat pond P is provided at the bottom of the flat pond p or the headrace channel constituting the liquid moving mechanism m. 11. The photosynthetic microorganism culturing apparatus according to claim 5, claim 6, claim 7, claim 7, claim 8, claim 9, or claim 10.  [12] A suspension in the flat pond p which fills the bottom of the flat pond p or the headrace channel forming the liquid transfer mechanism m with the aeration tank a, the upper closed aeration tank bl or the aeration tank b2 with a floating lid. A photosynthetic microorganism according to claim 5, characterized in that it has a residual liquid discharge pipe (e) for discharging s. 5.The photosynthetic microorganism according to claim 5, 6, 7, 8, 7, 8, 9, 10, or 11. Cultivation equipment.