WO2014046205A1 - Method for culturing microalga and facility for culturing microalga - Google Patents

Abstract

Provided is a method that is for culturing a microalga and that is characterized by carrying out: a membrane filtration step for obtaining a permeate that has permeated through a filtration membrane by means of membrane filtration of discharged water containing at least nitrogen content or phosphorus content; and a culturing step for culturing a microalga within a liquid containing the permeate. Also provided is a facility that is for culturing a microalga and that is provided with: a membrane filtration device that obtains a permeate that has permeated through a filtration membrane by means of membrane filtration of discharged water containing at least nitrogen content or phosphorus content; and a culturing device for culturing a microalga within a liquid containing the permeate.

Description

Microalgae culture method and microalgae culture equipment Cross-reference of related applications

This application claims the priority of Japanese Patent Application No. 2012-208718, which is incorporated herein by reference.

The present invention relates to a method for culturing microalgae and a culture facility for microalgae.

Conventionally, various methods for culturing microalgae are known. For example, as a method for culturing microalgae, a method for culturing microalgae in sewage containing domestic wastewater is known (Patent Document 1).

In this type of microalgae culture method, since sewage contains nitrogen and phosphorus, these components are used as nutrients for the growth of microalgae. Therefore, in this type of method for culturing microalgae, microalgae can be grown. And the proliferated microalgae can be used as a living material or an industrial material. And since the nitrogen content and phosphorus content in the sewage used for culture | cultivation can be reduced, the quality of the sewage can be improved.

Japanese Unexamined Patent Publication No. 08-107782

However, in this type of method for culturing microalgae, sewage is used as it is as a liquid for culturing microalgae. There is a problem that the growth of is inhibited. If the growth of microalgae is suppressed by microorganisms, the amount of microalgae obtained after culturing is not necessarily sufficient, and therefore the amount of microalgae that can be used is relatively small.

The present invention has been made in view of the above-mentioned problems and the like, and an object thereof is to provide a method for culturing microalgae that can sufficiently grow microalgae.

The method for culturing microalgae according to the present invention includes a membrane filtration step for obtaining permeated water that has permeated through a filtration membrane by subjecting wastewater containing at least one of nitrogen and phosphorus to membrane filtration, and a liquid containing the permeated water. And a culture process for culturing microalgae.

As one aspect of the method for culturing microalgae according to the present invention, prior to the membrane filtration step, a water treatment step of water treatment of the wastewater by an activated sludge method or anaerobic treatment is further performed, and water is treated in the water treatment step. The aspect which membrane-filters the processed waste_water | drain at the said membrane filtration process is employable.

As another aspect of the method for culturing microalgae according to the present invention, a sterilization step of sterilizing the permeate is further performed, and in the culturing step, the sterilization treatment is performed in the sterilization step. A mode in which microalgae are cultured in a liquid containing permeated water can be employed.

The apparatus for culturing microalgae according to the present invention includes a membrane filtration device for obtaining permeated water that has permeated through a filtration membrane by subjecting wastewater containing at least one of nitrogen and phosphorus to membrane filtration, and a liquid containing the permeated water. A culture apparatus for culturing microalgae therein.
As one aspect of the microalgae culture facility according to the present invention, the apparatus further comprises a water treatment device for water treatment of the wastewater by an activated sludge method or anaerobic treatment, and the membrane-filtered wastewater treated with the water treatment device Embodiments configured to send to the device may be employed.
As another aspect of the microalgae culturing facility according to the present invention, the microalgae further includes a sterilization apparatus that sterilizes the permeated water, and the cultivated permeated water that has been sterilized by the sterilization apparatus. Embodiments configured to send to the device may be employed.

Schematic showing the outline of the culture facility for microalgae. Schematic showing the modification of the culture equipment of microalgae.

Hereinafter, an embodiment of a microalgae culture facility according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the microalgae cultivation facility 20 of the present embodiment obtains permeated water that has permeated through a filtration membrane by subjecting the wastewater containing at least one of nitrogen and phosphorus to membrane filtration through the filtration membrane. A membrane filtration device 1 and a culture device 2 for culturing microalgae in the liquid A containing the permeated water are provided.

In the microalgae culture facility 20 of the present embodiment, since the wastewater is membrane-filtered by the membrane filtration device 1, at least a part of the microorganisms contained in the wastewater does not permeate the filtration membrane. Therefore, permeated water in which the microorganisms in the waste water are reduced can be obtained by the membrane filtration device 1. Then, in the culture apparatus 2, the microalgae are cultured in a liquid containing permeated water in which microorganisms are reduced. Therefore, in the culture of the microalgae in the culturing apparatus 2, the microbe algae is inhibited from being inhibited from growing due to the reduction of the microbes. In addition, the permeated water contains nitrogen and phosphorus contained in the waste water, and this nitrogen and phosphorus promotes the growth of microalgae. Therefore, the microalgae culture facility 20 can sufficiently grow the microalgae.
Thus, the culture facility for microalgae of the present embodiment has an effect that microalgae can be sufficiently grown.

The microalgae culture facility 20 of the present embodiment further includes a water treatment device 3 that treats the wastewater by an activated sludge method, and the wastewater treated by the water treatment device 3 is supplied to the membrane filtration device 1. Configured to send.
That is, as shown in FIG. 1, the microalgae culture facility 20 of the present embodiment includes a water treatment device 3 that treats wastewater containing at least one of nitrogen and phosphorus by an activated sludge method, and the water. A membrane filtration device 1 for obtaining permeated water that has permeated through a filtration membrane by subjecting the wastewater treated with water in the treatment device 3 to membrane filtration, and a culture device 2 for culturing microalgae in the liquid A containing the permeated water. I have.

More specifically, as shown in FIG. 1, the culture system 20 for microalgae of the present embodiment includes a culture component storage tank 10 that stores culture components that promote the growth of microalgae, and a culture component storage tank 10 that sends the culture components from the culture component storage tank 10. A mixing tank 4 for adjusting the liquid A to be more suitable for culture by preparing an aqueous solution by mixing the culture components to be transmitted and the permeated water sent from the membrane filtration device 1 and adding the aqueous solution to the liquid A of the culture device 2 And further. Further, the microalgae cultivation facility 20 of the present embodiment further includes a solid-liquid separation device 5 that separates the mixture of the microalgae and the liquid A cultured in the culture device 2 into the liquid A and the microalgae.

The waste water contains at least one of a nitrogen content (nitrogen-containing compound) and a phosphorus content (phosphorus-containing compound). The waste water contains microorganisms such as bacteria and protozoa that inhibit the growth of microalgae.

As the waste water, for example, sewage inflow water can be mentioned. Examples of the waste water include industrial waste water discharged from factories such as a brewery factory, a food factory, a chemical factory, an electronic industry factory, and a pulp factory, or treated water of such industrial waste water. When the waste water is sewage inflow water, the waste water may contain both nitrogen and phosphorus.

The nitrogen content includes organic nitrogen content and inorganic nitrogen content. The waste water usually contains an organic nitrogen content as a nitrogen content, and may further contain an inorganic nitrogen content as a nitrogen content.

Examples of the organic nitrogen content include proteins and amino acids.
Examples of the inorganic nitrogen component include ammonia ions and nitrate ions.

Examples of the phosphorus content include organic phosphorus content and inorganic phosphorus content. The waste water usually contains an organic phosphorus content as a phosphorus content, and may further contain an inorganic phosphorus content as a phosphorus content.
Examples of the organic phosphorus content include phospholipids and nucleic acids.
Examples of the inorganic phosphorus content include phosphate ions.

The water treatment apparatus 3 has an aeration tank 3a for agitating wastewater supplied from outside the culture facility 20 with activated sludge and an aeration pipe 3b for supplying a gas containing oxygen to the aeration tank 3a.

The water treatment device 3 is configured to accommodate wastewater in the aeration tank 3a and to treat the wastewater with activated sludge while aeration of the wastewater with the gas supplied from the aeration pipe 3b. The water treatment device 3 is configured to send water-treated wastewater to the membrane filtration device 1.

The aeration tank 3a is configured to perform water treatment for decomposing a compound in waste water into a compound having a lower molecular weight under an aerobic condition by using activated sludge containing biological species such as bacteria, protozoa, and metazoans. ing.

The aeration pipe 3b is arranged at the bottom of the aeration tank 3a, and is configured to supply air or the like as a gas containing oxygen in the form of bubbles from the bottom side of the aeration tank 3a into the waste water.

By treating the wastewater with the water treatment device 3, the compound contained in the wastewater is decomposed into a compound having a lower molecular weight. Specifically, the compound contained in the waste water is decomposed into, for example, carbon dioxide.
Moreover, when the waste water is water-treated by the water treatment device 3, for example, the nitrogen content (nitrogen-containing compound) in the waste water is decomposed into nitrogen content such as ammonia ions and nitrate ions having smaller molecular weights. Similarly, the phosphorus content (phosphorus-containing compound) in the wastewater is decomposed into phosphorus content such as phosphate ions having a lower molecular weight.
As described above, the wastewater subjected to water treatment by the water treatment apparatus 3 contains nitrogen, phosphorus, and the like that have been reduced in molecular weight by water treatment. Nitrogen and phosphorus that have been reduced in molecular weight by water treatment are easier for microalgae to use as nutrients in growth than before they are reduced in molecular weight.
Therefore, the wastewater treated by the water treatment device 3 contains nitrogen and phosphorus that are easy for microalgae to use as nutrients.

As shown in FIG. 1, the membrane filtration device 1 includes a filtration tank 1 a that contains wastewater that is water-treated by the activated sludge method in the water treatment device 3 and that is supplied from the water treatment device 3, And a membrane unit 1b including a filtration membrane disposed in the filtration tank 1a. And the membrane filtration apparatus 1 is comprised so that the permeated water which permeate | transmitted the filtration membrane may be obtained by carrying out the membrane filtration of the waste_water | drain after water treatment with the membrane unit 1b. The membrane filtration device 1 is configured to send the obtained permeated water to the mixing tank 4. In addition, the membrane filtration device 1 includes a gas supply pipe 1c that supplies a bubble-like gas to the surface of the membrane unit 1b in order to suppress microorganisms from adhering to the surface of the membrane unit 1b.

The membrane unit 1b has a filtration membrane. And the membrane unit 1b is comprised so that the permeated water which permeate | transmitted the filtration membrane may be obtained at least by carrying out the membrane filtration of the waste_water | drain after the water treatment. Further, the membrane unit 1b is arranged in the filtration tank 1a so as to be immersed in the wastewater subjected to water treatment.
Specifically, as shown in FIG. 1, the membrane unit 1b is usually immersed in the wastewater stored in the filtration tank 1a so as to be in contact with the wastewater on the outer surface. The membrane unit 1b is configured, for example, to perform membrane filtration from the outside to the inside by setting the inside to a negative pressure, and to remove permeated water that has permeated the filtration membrane.

The filtration membrane is formed with pores having a size that reduces microorganisms such as bacteria and protozoa in the wastewater by filtration. That is, the filtration membrane has a large number of pores formed such that the number of microorganisms in the permeated water that has permeated the filtration membrane is smaller than the number of microorganisms in the waste water before filtration.

The filtration membrane is preferably an ultrafiltration membrane (UF membrane) or a microfiltration membrane (MF membrane) in that microorganisms in the waste water can be more reliably reduced by filtration.

The pore size of the ultrafiltration membrane (UF membrane) is usually 0.001 to 0.01 μm. According to the ultrafiltration membrane (UF membrane) in which pores of such a size are formed, it is possible to prevent permeation of high-molecular substances and colloidal substances having a molecular weight of 1,000 to several hundred thousand. Moreover, permeation of microorganisms such as bacteria and protozoa can be prevented.
The pore size of the microfiltration membrane (MF membrane) is usually more than 0.01 μm and 10 μm or less. The pore size of the microfiltration membrane (MF membrane) is preferably 0.45 μm or less from the viewpoint that the permeation of bacteria can be more reliably prevented.
By adopting an ultrafiltration membrane (UF membrane) or a microfiltration membrane (MF membrane) as the filtration membrane, it is possible to completely prevent microorganisms in the waste water from passing through the filtration membrane in filtration, It is also possible to obtain permeated water that does not contain microorganisms. By culturing microalgae in the culture apparatus 2 described later using such permeated water, it is possible to more reliably suppress the inhibition of microalgae growth due to microorganisms.

A conventionally well-known thing is mentioned as a shape of the said filtration membrane. For example, examples of the shape include a so-called hollow fiber membrane formed in a hollow fiber shape, or a plate-like flat membrane shape.
Examples of the material for the filtration membrane include PVDF (polyvinylidene fluoride), cellulose, polyamide, and ceramic.

The permeated water contains at least a nitrogen content and / or a phosphorus content contained in the waste water. When the permeated water is contained in the liquid A used for culturing in the culture of the microalgae in the culture apparatus 2 described later, the nitrogen content and the phosphorus content contained in the permeated water become nutrient components of the microalgae. . Thereby, the permeated water can make the growth of microalgae sufficient.
Moreover, since the permeated water permeates the filtration membrane in the membrane filtration device 1, as described above, the number of microorganisms in the permeated water is smaller than the number of microorganisms in the waste water before filtration. Therefore, when the permeated water is used in the culture of microalgae in the culture apparatus 2 described later, the growth inhibition of microalgae by microorganisms can be suppressed by the amount of the microorganisms.

Further, as described above, the nitrogen content and the phosphorus content contained in the permeated water have been reduced in molecular weight by the water treatment in the water treatment device 3, and thus are more easily utilized in the growth of microalgae. ing.
Therefore, in the cultivation of microalgae in the culture apparatus 2 described later, by culturing the microalgae in the liquid A containing the permeated water, the low-molecular nitrogen content and phosphorus content that are easier to use are finely divided. Algae can be used. Therefore, the growth of microalgae is promoted.

The membrane filtration device 1 has the gas supply pipe 1c as described above. And the membrane filtration apparatus 1 is comprised so that the surface of the membrane unit 1b may be wash | cleaned with the bubble-like gas supplied from the gas supply pipe | tube 1c.
As the gas supplied by the gas supply pipe 1c, air is usually employed, and preferably, a gas such as exhaust gas having a higher carbon dioxide concentration than air is employed.
By adopting a carbon dioxide-containing gas such as air as the gas supplied to the outer surface of the membrane unit 1b, carbon dioxide is dissolved in the liquid A in the subsequent culture apparatus 2, and the dissolved carbon dioxide is photosynthesis of microalgae. Used for

The membrane filtration device 1 may not be configured to membrane-filter the wastewater that has been water-treated in the water treatment device 3.
That is, the microalgae culture facility 20 of the present embodiment does not include the water treatment device 3, and the membrane filtration device 1 uses the membrane unit 1 b to treat the wastewater supplied without passing through the water treatment device 3. It may be configured to obtain permeated water by filtration.

Also, the microalgae culturing facility 20 of the present embodiment is configured so that the membrane unit 1b of the membrane filtration device 1 is immersed in the wastewater stored in the aeration tank 3a of the water treatment device 3, as shown in FIG. The processing apparatus 3 and the membrane filtration apparatus 1 may be arranged. That is, in the microalgae cultivation facility 20 of the present embodiment, the membrane filtration device 1 does not have the filtration tank 1a and the gas supply pipe 1c, and the membrane unit 1b of the membrane filtration device 1 is aerated in the water treatment device 3. You may distribute | arrange so that the waste_water | drain in the tank 3a may be immersed.

The culture component storage tank 10 stores culture components that promote the growth of microalgae and supplies the culture components to the mixing tank 4.

Examples of the culture components include organic culture components and inorganic culture components.

Examples of the organic culture component include sugars such as glucose, amino acids, alcohols such as ethanol, vitamins, and the like.
Examples of the inorganic culture component include nitrogen-containing inorganic compounds containing nitrogen, phosphorus-containing inorganic compounds containing phosphorus, and the like. Examples of the inorganic culture component include potassium ions, iron ions, manganese ions, cobalt ions, zinc ions, copper ions, molybdenum ions, nickel ions, and the like.

The culture component storage tank 10 may be configured to store each of the culture components. That is, the microalgae cultivation facility 20 may include a plurality of culture component storage tanks 10 in order to store a plurality of types of culture components in the culture component storage tanks 10 respectively.

The mixing tank 4 has a stirrer 4a, and is configured to mix the permeate sent from the membrane filtration device 1 and the culture components supplied from the culture component storage tank 10 by the stirrer 4a. Further, the mixing tank 4 is configured to send an aqueous solution containing microalgae culture components obtained by mixing to the culture apparatus 2.

According to the mixing tank 4, a predetermined amount of permeate and culture components are supplied into the culture tank 2a so that the liquid A contained in the culture tank 2a of the culture apparatus 2 contains appropriate amounts of permeate and culture components. can do.

The microalgae cultivation facility 20 may include a detection sensor 11 for detecting at least a nitrogen content and / or a phosphorus content.

For example, the detection sensor 11 may be arranged such that the detection unit is immersed in the wastewater stored in the filtration tank 1a in order to detect components in the wastewater stored in the filtration tank 1a of the membrane filtration device 1. Good. Further, for example, as shown in FIG. 1, the detection sensor 11 may be arranged so that the detection unit is immersed in the aqueous solution in the mixing tank 4 in order to detect components in the aqueous solution prepared in the mixing tank 4. Good. The microalgae culture facility 20 includes two detection sensors 11, and the detection unit of one of the detection sensors 11 is immersed in the wastewater stored in the filtration tank 1 a, and the other detection is performed in the aqueous solution in the mixing tank 4. The detection part of the sensor 11 may be immersed.
The microalgae culture facility 20 is configured to detect the concentration of nitrogen or phosphorus by the detection sensor 11. Then, when the detected concentration is less than the predetermined value, the microalgae culture facility 20 supplies the culture components from the culture component storage tank 10 to the mixing tank 4 by sending an electrical signal to the culture component storage tank 10. It is configured as follows.

The culture apparatus 2 has a culture tank 2a for accommodating microalgae and liquid A for culturing the microalgae. The culture apparatus 2 is configured to take the permeated water sent through the mixing tank 4 into the culture tank 2a and to culture microalgae in the liquid A containing the permeated water in the culture tank 2a. ing. Specifically, examples of the culture apparatus 2 include an open pond and a photobioreactor.

In the culture device 2, microalgae are cultured in the liquid A containing the permeated water obtained in the membrane filtration device 1. Moreover, the permeated water contains at least one of nitrogen and phosphorus, which are nutrients in the growth of microalgae. Therefore, in the culture apparatus 2, the permeated water contains at least one of the nitrogen content and the phosphorus content, so that the growth of microalgae can be promoted.

Further, in the culture apparatus 2, the permeated water permeates the filtration membrane in the membrane filtration apparatus 1. Therefore, as described above, the permeation that has permeated the filtration membrane from the number of microorganisms in the wastewater before filtration. The number of microorganisms in the water is low. Therefore, in the culture device 2, inhibition of the growth of microalgae by microorganisms can be suppressed by the amount of microorganisms in the permeated water being reduced. Thereby, the growth of microalgae can be promoted.
Specifically, when microorganisms such as protozoa and metazoans coexist with microalgae, the microbes use nutrient components necessary for the microalgae to grow. Therefore, the amount of nutrients used by microalgae can be reduced by the amount of nutrients used by microorganisms. In addition, microorganisms such as protozoa and metazoans use microalgae as nutrient components (predation), and the growth of microorganisms can be superior to the growth of microalgae. Therefore, the growth of microalgae can be suppressed.
By reducing microorganisms such as bacteria and protozoa with a filtration membrane, the nutrient components contained in the permeate can be used for the growth of microalgae as much as the microorganisms are reduced. Therefore, the growth of microalgae can be promoted.

In the culture device 2, the nitrogen content and the phosphorus content contained in the permeated water are reduced in molecular weight by the water treatment of the waste water in the water treatment device 3. Therefore, the nitrogen content and the phosphorus content contained in the permeated water are in an aspect that microalgae can more easily use in the growth. As described above, in the culture apparatus 2, by culturing the microalgae in the liquid A containing such permeated water, the microalgae can use the nitrogen component having a low molecular weight that is easier to use. Therefore, the growth of microalgae can be promoted.
For example, even if the waste water contains a hardly decomposable polymer substance, the polymer material is reduced in molecular weight to be relatively easily decomposable by treating the waste water with the water treatment device 3. It becomes a substance. Therefore, microalgae can easily utilize a relatively easily degradable substance having a low molecular weight as a nutrient component. Thereby, the growth of microalgae can be promoted.

Note that most of the liquid A accommodated in the culture tank 2a is usually water. In addition to water, the liquid A may further contain a nitrogen content and a phosphorus content contained in the waste water, and the above-described organic culture components and inorganic culture components.

Unlike the kelp and wakame, the microalgae are usually unicellular. The microalgae are microalgae having a size of approximately several micrometers to several tens of micrometers.
Examples of the microalgae include photoautotrophic microalgae that grow by photosynthesis, heterotrophic microalgae that grow using organic carbon such as glucose as a nutrient source, and the like. Incidentally, those Some of the photoautotrophic microalgae, available as described below Euglena (Euglena) belonging to the genus organisms and Chlorella (Chlorella) belonging to the genus organism, a and organic carbon can be photosynthesis as a nutrient source There is also.

Examples of the microalgae include organisms belonging to the genus Euglena , organisms belonging to the genus Chlorella , organisms belonging to the genus Aurantiochytrium , organisms belonging to the genus Auxenochlorella, botuliococcus Organisms belonging to the genus ( Botryococcus ), organisms belonging to the genus Nannochloris , organisms belonging to the genus Nannochloropsis , organisms belonging to the genus Neochloris , organisms belonging to the genus Pseudochoricystis , Scenedesmus (Scenedesmus) belonging to the genus organism, and, Schizochytrium (Schizochytorium) at least one member selected from the group consisting of organism belonging to the genus are preferred.

Examples of the photoautotrophic microalgae include organisms belonging to the genus Euglena , organisms belonging to the genus Chlorella , organisms belonging to the genus Auxenochlorella , organisms belonging to the genus Botryococcus , Kurorisu (Nannochloris) belonging to the genus organism, Nannochloropsis (Nannochloropsis) belonging to the genus organism, Neokurorisu (Neochloris) belonging to the genus organism, shoe DoCoMo lysis Chis (Pseudochoricystis) belonging to the genus organism, and belong to Scenedesmus (Scenedesmus) genus At least one selected from the group consisting of organisms is preferred.

As the heterotrophic microalgae, O lunch Oki thorium (Aurantiochytrium) belonging to the genus organism, or Schizochytrium (Schizochytorium) belonging to the genus organisms, are preferred.

Organisms belonging to the Euglena (Euglena) genus, for example, Euglena gracilis, E uglena longa, Euglena caudata, Euglena oxyuris, Euglena tripteris, Euglena proxima, Euglena viridis, Euglena sociabilis, Euglena ehrenbergii, Euglena deses, Euglena pisciformis, Euglena spirogyra Euglena acus , Euglena geniculata , Euglena intermedia , Euglena mutabilis , Euglena sanguinea , Euglena stellata , Euglena terricola , Euglena klebsi , Euglena rubra , or Euglena cyclopicola .
As the Euglena gracilis, for example, and the like (storage strains in later to Independent Administrative Institution National Institute for Environmental Studies microorganism strain preservation facility) Euglena gracilis NIES-48.

Examples of the organism belonging to the genus Chlorella include Chlorella vulgaris , Chlorella pyrenoidosa , or Chlorella sorociniana .
As the Chlorella sorociniana, for example, and the like (storage strains in later to Independent Administrative Institution National Institute for Environmental Studies microorganism strain preservation facility) Chlorella sorociniana NIES-2169.

Organisms belonging to the Orchidee Imperiale Seno Chlorella (Auxenochlorella) genus, for example, like Auxenochlorella protothecoides.

Examples of the organism belonging to the genus Botryococcus include Botryococcus braunii .

Organisms belonging to the Nan'nokurorisu (Nannochloris) genus, for example, Nannochloris Bacillaris, like Nannochloris normandinae.

Organisms belonging to the Nannochloropsis (Nannochloropsis) genus, for example, like Nannochloropsis oculata.

Organisms belonging to the Neokurorisu (Neochloris) genus, e.g., Neochloris aquatica, Neochloris cohaerens, Neochloris conjuncta, Neochloris gelatinosa, Neochloris pseudostigmata, Neochloris pseudostigmatica, Neochloris pyrenoidosa, Neochloris terrestris, Neochloris texensis, Neochloris vigensis, Neochloris wimmeri, Neochloris oleoabundans etc. Is mentioned.

Examples of the organism belonging to the genus Pseudochoricystis include Pseudochoricystis ellipsoidea .

Organisms belonging to the Scenedesmus (Scenedesmus) genus, for example, Scenedesmus ovaltermus, Scenedesmus disciformis, Scenedesmus acumunatus, like Scenedesmus dimorphus.

Organisms belonging to the O-lunch Oki thorium (Aurantiochytrium) genus, for example, Aurantiochytrium limacinum, or the like Aurantiochytrium mangrovei.

Examples of the organism belonging to the genus Schizochytorium include Schizochytrium aggregatum .

The above microalgae can be obtained from the National Institute for Environmental Studies, the National Institute for Environmental Studies, the National Institute for Environmental Studies, the National Institute for Environmental Studies (NIES), the Patent Microorganism Depositary Center (Postal Code 292-0818, Kisarazu-shi, Chiba Prefecture) Postal code 305-8506 (16-2 Onagawa, Tsukuba City, Ibaraki Prefecture), or The Culture Collection of Algae at the University of Texas at Austin, USA (http://web.biosci.utexas.edu/utex/default.aspx) It is easily obtained from

As the microalgae, it is possible to accumulate a large amount of triglyceride as a raw material for biodiesel, to contain a lot of valuable materials such as dietary fiber, vitamins, carotenoids, proteins, linoleic acid, linolenic acid, and to culture in large quantities From the viewpoint that it is easy to do, organisms belonging to the genus Chlorella are preferred.
The microalgae can accumulate a large amount of wax ester as a raw material for biodiesel, contain a large amount of valuable substances such as vitamins, carotenoids, nutritious proteins, paramylon, and culture in large quantities. Organisms belonging to the genus Euglena are preferred in that they are easy to do.

The culture device 2 has a stirring device that stirs the microalgae and the liquid A in the tank.

The culture apparatus 2 includes a lighting device 2b that irradiates light B from above the culture tank 2a toward the culture tank 2a in order to cause the microalgae to perform photosynthesis.

The culture tank 2a is relatively shallow so that the light B irradiated from above passes through the liquid A and reaches the bottom in order to promote the photosynthesis of the microalgae contained in the culture tank 2a. Is formed.

As shown in FIG. 1, the culture tank 2a is configured such that light B from the lighting device 2b is irradiated to the microalgae in the liquid A to be stored.

The culture device 2 may be configured to grow the microalgae by photoautotrophic culture while irradiating the microalgae with the light B. That is, the culture apparatus 2 may be configured to grow microalgae under bright conditions.
By irradiating the microalgae with light B in the culture apparatus 2, the photoautotrophic microalgae can grow while taking carbon dioxide into the cells by photosynthesis and synthesizing hydrocarbons, sugars, etc. It proliferates using the components in A (for example, the above-mentioned organic nitrogen content etc.) as nutrient components.

Moreover, the said culture apparatus 2 may be comprised so that a micro algae may be propagated by light heterotrophic culture, irradiating light B to a micro algae. That is, the culture apparatus 2 may be configured to grow the microalgae while photosynthesis of the microalgae by light irradiation in a liquid containing oxygen, carbon dioxide, and a carbon source.
By irradiating light B to the microalgae in the culture apparatus 2 in the presence of oxygen and carbon dioxide (that is, aeration of liquid A with a gas containing oxygen and carbon dioxide), photosynthesisable microalgae are photosynthesized. In addition, microalgae can be grown by heterotrophic culture in liquid A containing a carbon source.

On the other hand, the culture apparatus 2 may be configured to grow microalgae by heterotrophic culture without irradiating light B. That is, the culture apparatus 2 may be configured to grow microalgae under dark conditions.
By placing the microalgae in a dark condition without irradiating the light B in the culture apparatus 2 and performing aeration with an aeration tube to be described later, the microalgae can be obtained from a carbon source in the liquid A (for example, the sugars described above, or It grows using alcohol or the organic nitrogen content mentioned above.

In the case where the culture apparatus 2 is configured to culture microalgae only by heterotrophic culture, the culture tank 2a is compared in that oxygen is easily dissolved in the liquid A for culture. It may be formed deeply.

The culture apparatus 2 may be configured to irradiate the microalgae with natural light from the sun, for example, instead of irradiating the microalgae with the light B by the lighting device 2b.

The intensity of light B or natural light irradiated by the lighting device 2b is not particularly limited, but when cultivating an organism belonging to the genus Euglena as a microalgae, 50 μmol / m ² / s to 200 μmol / m ² / It is preferable that it is s.
When the light intensity is 50 μmol / m ² / s or more, there is an advantage that photosynthesis can be further promoted. Moreover, there exists an advantage that the growth inhibition by light can be suppressed more reliably because the intensity | strength of light is 200 micromol / m < ² > / s or less.

The culture apparatus 2 is configured to alternately provide a period in which the microalgae are irradiated with the light B and a period in which the light B is not irradiated while the microalgae are grown in the liquid A in the culture tank 2a. It is preferable.
That is, the culture apparatus 2 repeatedly and alternately provides a period for growing microalgae while irradiating microalgae with light B to perform photosynthesis and a period for growing microalgae under dark conditions. It is preferable to be configured.
The period during which the microalgae are irradiated with the light B in the culture apparatus 2 is preferably 8 hours to 15 hours. Further, the period of dark conditions in which microalgae are not subjected to photosynthesis is preferably 9 to 16 hours.

The culture apparatus 2 is configured such that the culture temperature in the culture tank 2a is controlled to 20 ° C. to 35 ° C., for example.

The pH of the liquid A in the culture apparatus 2 is not particularly limited as long as it is a pH at which microalgae can grow. The pH is, for example, 3.0 to 5.5 when culturing organisms of the genus Euglena .
In order to adjust the pH of the liquid A, an inorganic acid such as hydrochloric acid may be added to the liquid A, or an organic acid such as acetic acid may be added to the liquid A. Moreover, you may use combining an inorganic acid and an organic acid. By adding an organic acid to the liquid A, microalgae can grow using the organic acid as a carbon source.

The culture apparatus 2 has an air diffuser for aeration of the liquid A in the culture tank 2a.
Specifically, the culture apparatus 2 supplies the liquid A by supplying air or the like into the liquid A via an air diffuser in order to supply oxygen for respiration to the microalgae in the culture tank 2a. It is configured to diffuse.
In addition, the culture device 2, for example, photosynthesizes microalgae while aerating the liquid A by supplying a gas containing a relatively large amount of carbon dioxide to the liquid A in the culture tank 2 a via an air diffuser. It is comprised so that it may perform.
The culture apparatus 2 is also configured to place the liquid A under anaerobic conditions by stopping the diffusion from the diffusion tube.

The culture apparatus 2 may be configured to always diffuse the liquid A in the culture tank 2a. Moreover, the said culture apparatus 2 may be comprised so that the liquid A in the culture tank 2a may be diffused only when culture | cultivating a micro algae under dark conditions.
The culture apparatus 2 is configured to supply carbon dioxide used for photosynthesis or oxygen used for respiration into the liquid A through an air diffuser during the cultivation of microalgae. The oxygen supply means is not limited to the air diffuser. Specifically, as the supply means, for example, means for stirring the liquid A using a stirring blade in order to dissolve the supplied carbon dioxide and oxygen in the liquid A in the culture tank 2a, or supplied A means for supplying pressurized liquid in which carbon dioxide or oxygen is pressurized and dissolved to the liquid A may be employed.

The culture apparatus 2 employs, for example, an organism belonging to the genus Euglena as a microalgae. Under conditions where light B is irradiated, an organic substance is produced from carbon dioxide by photosynthesis while growing the Euglena genus organism. It is configured to synthesize (polysaccharides, lipids, etc.) and store the organic matter in cells.
On the other hand, the culture apparatus 2 synthesizes organic substances (polysaccharides, lipids, etc.) from organic carbon in the liquid A under the dark condition where the light B is not irradiated while growing Euglena genus organisms. It is configured to store organic matter in cells. The Euglena genus organism in which the organic substance is stored in cells can be recovered, for example, and used directly as a valuable resource.
Furthermore, the culture apparatus 2 by placing the polysaccharide and Euglena was stored organic matter such as lipids (Euglena) genus organism into the cell under anaerobic conditions in the dark, Euglena (Euglena) genus organisms wax into cells It is configured to store esters and the like. The stored wax ester can be used as a raw material for fuels, chemical products and the like by being taken out from the cells of Euglena genus organisms.

The solid-liquid separation device 5 is configured such that a mixture of the microalgae cultured in the culture device 2 and the liquid A is supplied from the culture device 2, and the mixture is separated into the liquid and the microalgae. It is configured.

The solid-liquid separation device 5 includes a concentration processor that performs a concentration process such as flotation concentration, gravity concentration, and membrane concentration on a mixture of microalgae and liquid A, for example. Further, the solid-liquid separation device 5 is, for example, a vacuum dehydrator, a pressure dehydrator (filter press), a belt press, a screw press, or a centrifugal concentration dehydrator in order to dehydrate the microalgae after the concentration process. (Screw decanter), or a multiple disk dehydrator.

As shown in FIG. 1, the microalgae culture facility 20 includes a microalgae extraction pipe 6 that extracts microalgae obtained by separation in the solid-liquid separator 5 to the outside of the facility.
The microalgae culture facility 20 is configured to send the separated microalgae out of the culture facility 20 by the microalgae extraction pipe 6. For example, the microalgae sent to the outside of the culture facility 20 are collected as they are and used according to the purpose.

As shown in FIG. 1, the microalgae cultivation facility 20 includes a liquid extraction pipe 7 that takes out the liquid obtained by the separation in the solid-liquid separation device 5 to the outside of the facility.
The microalgae culture facility 20 is configured to send the separated liquid to the outside of the culture facility 20 through the liquid extraction pipe 7. The separated liquid sent to the outside of the culture facility 20 is discharged, for example, as it is or after being further treated with water.

As shown in FIG. 1, the microalgae cultivation facility 20 includes a permeate extraction pipe 12 that takes out permeate that has permeated through the filtration membrane of the membrane unit 1 b in the membrane separation apparatus 1 to the outside of the facility. The part may be configured to be sent out of the culture facility 20 by the permeated water extraction pipe 12.
The water quality of the liquid obtained by the separation in the solid-liquid separator 5 is not always better than the quality of the permeated water because it is affected by the type of drainage and the type of microalgae. Thus, in such a liquid, for example, the concentration of suspended matter can be higher than in permeate. Therefore, if the quality of the permeated water is better than the quality of the liquid obtained by the separation in the solid-liquid separator 5, the permeated water can be discharged out of the culture facility 20 and the permeated water can be directly discharged. Further, when the separated liquid or permeate discharged to the outside of the culture facility 20 is further purified by the purification facility, a part of the permeate having better water quality is discharged outside the culture facility 20 and after the separation. Can be added to the liquid. Thereby, the purification degree of the liquid after the separation can be increased, and the load on the purification equipment can be reduced.

The microalgae cultivation facility 20 includes a liquid recovery pipe 8 that sends the liquid after the microalgae culture in the culture apparatus 2 to the aeration tank 3a and / or the filtration tank 1a of the water treatment apparatus 3.
Specifically, as shown in FIGS. 1 and 2, the microalgae culture facility 20 uses a liquid (liquid after microalgae culture) obtained by separation in the solid-liquid separator 5 as a water treatment device. 3 aeration tank 3a and / or a liquid recovery pipe 8 to be sent to the filtration tank 1a of the membrane filtration device 1.
For example, as shown in FIG. 1, one end of the liquid recovery pipe 8 is attached in the middle of the liquid extraction pipe 7. The other end of the liquid recovery pipe 8 is divided into two, and the other ends are arranged so as to supply the liquid to the aeration tank 3a and / or the filtration tank 1a of the water treatment device 3. A valve is attached to one end of the liquid recovery pipe 8. Then, by controlling this valve, the liquid recovery pipe 8 sends the liquid that has passed through the liquid extraction pipe 7 to the other end side, and sends the liquid from each of the other ends to the aeration tank 3a and / or the filtration tank 1a. It is configured to supply.

As described above, the microalgae culture facility 20 is configured to send the liquid after the culture of the microalgae in the culture apparatus 2 to the aeration tank 3a of the water treatment apparatus 3 and / or the filtration tank 1a of the membrane filtration apparatus 1. Has been.
In the culture facility 20 for microalgae, the amount of water newly added in the culture facility 20 can be reduced by the amount of the liquid after culturing the microalgae being used again in the culture facility 20. That is, the microalgae culture equipment is obtained by water-treating the liquid after cultivation of microalgae in the aeration tank 3a by the activated sludge method and / or adding the liquid after culture of microalgae to the filtration tank 1a. The amount of water newly added at 20 can be reduced.

Further, the liquid after the microalgae are cultured contains a growth inhibitory component generated from the microalgae along with the growth of the microalgae. However, when the liquid containing the component is sent to the aeration tank 3a and water-treated by the activated sludge method, at least part of the growth inhibiting component is decomposed by the activated sludge method, so that the growth inhibiting component is May decrease. Therefore, when the liquid after culturing the microalgae is water-treated in the aeration tank 3a by the activated sludge method, adverse effects due to the microalgae growth inhibitory component can be suppressed in the culture of the microalgae in the culture apparatus 2.

The microalgae cultivation facility 20 may include a sterilization apparatus 9 for sterilizing the aqueous solution obtained in the mixing tank 4 and containing the above-described culture components, as shown in FIG. That is, the culture facility 20 for microalgae includes a sterilization apparatus 9 that performs sterilization treatment on the permeated water, and sends the permeated water that has been sterilized by the sterilization apparatus 9 to the culture apparatus 2. It may be configured.

The sterilization apparatus 9 is configured to be supplied with the aqueous solution obtained in the mixing tank 4. The sterilization apparatus 9 is configured to sterilize permeated water and culture components contained in the aqueous solution, and supply the sterilized aqueous solution containing the permeated water and culture components to the culture apparatus 2. Yes.

Specifically, the sterilization apparatus 9 is configured to perform sterilization processing by, for example, heating using heat such as water vapor, filtration removal of bacteria using a filtration membrane, or the like.

In the sterilization apparatus 9, the microorganisms contained in the permeated water that has passed through the filtration membrane can be further reduced. In addition, bacteria and the like that can be included in the culture components can be reduced by sterilization treatment.

In the microalgae culture facility 20 of the present embodiment, by using the sterilization apparatus 9, the permeated water and the culture components that have passed through the mixing tank 4 are sterilized and sent to the culture apparatus 2. The adverse effect of microorganisms on growth can be more reliably suppressed. Thereby, microalgae can be more fully proliferated.

In the microalgae culturing facility 20 of the present embodiment, since at least drainage is used as a liquid for culturing microalgae, industrial water and tap water used as liquids for cultivating microalgae by the amount of wastewater used. The amount can be reduced. Therefore, in the microalgae culture facility 20 of the present embodiment, the cost for operation can be relatively small.
In addition, the microalgae culturing equipment 20 of the present embodiment can cultivate microalgae using wastewater that is normally discarded, and can obtain valuable resources from the cultured microalgae. Thus, there is an advantage that the profit obtained for the cost spent for operation is relatively high.

The microalgae culture facility 20 of the present embodiment includes a water treatment device that treats the wastewater by anaerobic treatment, and is configured to send the wastewater treated by the water treatment device to the membrane filtration device 1. May be.
The water treatment apparatus (which treats the wastewater by anaerobic treatment) has an anaerobic treatment tank that accommodates the wastewater supplied from outside the culture facility 20, and treats the wastewater by anaerobic treatment in the anaerobic treatment tank. It is configured.
The anaerobic treatment tank is configured to perform water treatment by anaerobic microorganisms to decompose a compound in waste water into a compound having a lower molecular weight under anaerobic conditions. The anaerobic treatment tank is configured to send wastewater such as digested liquid and digested and desorbed liquid subjected to anaerobic treatment to the membrane filtration device 1.
Specifically, as the anaerobic treatment tank, for example, a digestion apparatus configured to perform an upflow anaerobic process (UASB method) using granules, or a digestion configured to process sewage sludge. A tank or the like may be employed.
Specifically, as the anaerobic treatment, for example, an anaerobic digestion treatment or the like may be employed. By performing the anaerobic digestion treatment, waste water (digestion liquid) containing a relatively large amount of ammonia, phosphoric acid and the like, which are reduced in molecular weight due to decomposition of the nitrogen content and phosphorus content in the waste water, is generated. Such drainage (digested liquid) is subjected to membrane filtration in a membrane filtration device, so that permeated water containing a relatively large amount of ammonia, phosphoric acid and the like is generated, and the permeated water is used for culturing microalgae in the culture device. It becomes.
As described above, in the microalgae cultivation facility equipped with the anaerobic treatment tank, ammonia and the like produced by the anaerobic treatment can be used for culturing the microalgae, so that ammonia can be used without chemical decomposition treatment such as ammonia. Etc. can be decomposed by microalgae.

In addition, when the water treatment apparatus has an anaerobic treatment tank and a membrane unit is arranged in the anaerobic treatment tank, the anaerobic treatment tank contains wastewater to be contained in order to remove sludge and the like attached to the membrane unit. It may be configured to supply a bubble-like gas.
As such a gas, a gas not containing oxygen (such as an inert gas or carbon dioxide) is employed.
Since the anaerobic treatment tank is configured to supply such gas to the waste water, the membrane unit can be cleaned and the inside of the anaerobic treatment tank can be kept in an anaerobic state.

Next, an embodiment of the method for culturing microalgae according to the present invention will be described.

In the method for culturing microalgae of the present embodiment, the following steps can be performed by using the above-described devices. Further, in the method for culturing microalgae of the present embodiment, the above-described operations and the like are appropriately employed.

The method for culturing microalgae of the present embodiment includes a membrane filtration step for obtaining permeated water that has permeated through a filtration membrane by subjecting wastewater containing at least one of nitrogen and phosphorus to a membrane through a filtration membrane, and the permeated water. A culture step of culturing microalgae in a liquid containing

In the method for culturing microalgae of the present embodiment, permeated water in which microorganisms in the wastewater are reduced is obtained in the membrane filtration step. In the culturing step, microalgae are cultured in a liquid containing the permeated water in which microorganisms are reduced. Therefore, the inhibition of the growth of microalgae due to the microorganisms is suppressed in the culture of the microalgae in the culture process as much as the number of microorganisms is reduced.
That is, in the method for culturing microalgae of the present embodiment, since the permeated water permeates the filtration membrane, the number of microorganisms in the permeated water is smaller than that in the drainage before filtration. Therefore, it is possible to suppress the inhibition of the growth of microalgae by the amount of the microorganisms.
Therefore, the method for culturing microalgae of the present embodiment has an effect that microalgae can be sufficiently grown.

In the method for culturing microalgae, before the membrane filtration step, a water treatment step of treating the wastewater with an activated sludge method or anaerobic treatment is further performed, and the wastewater treated with water in the water treatment step is subjected to membrane filtration. It is preferable to obtain permeated water by membrane filtration in the process.
That is, in the method for culturing microalgae, a water treatment step in which wastewater containing at least one of nitrogen and phosphorus is treated with an activated sludge method or anaerobic treatment, and a water treatment step in the water treatment step with a filtration membrane. It is preferable to carry out a membrane filtration step for obtaining permeated water that has permeated the filtration membrane by subjecting the treated wastewater to membrane filtration, and a culture step for culturing microalgae in a liquid containing the permeated water.

By performing the water treatment step, the nitrogen content (nitrogen-containing compound) in the wastewater can be decomposed into nitrogen content such as ammonia and nitrate ions having a lower molecular weight. Similarly, the phosphorus content (phosphorus-containing compound) in the wastewater can be decomposed into phosphorus content such as phosphate ions having a lower molecular weight. That is, the wastewater that has been subjected to water treatment in the water treatment step contains nitrogen, phosphorus, and the like that have been reduced in molecular weight by water treatment. These components are easier for microalgae to use as nutritional components in growth than before the molecular weight is reduced.
Wastewater that has been water-treated in the water treatment process contains nitrogen and phosphorus that are easily utilized by microalgae as nutrients. Therefore, permeated water is obtained from the wastewater in the membrane filtration step, and the permeated water is contained in the liquid A in the culturing step, whereby the growth of microalgae can be further promoted.
That is, in the method for culturing microalgae, by further carrying out a water treatment step, the drainage water treated in the water treatment step is subjected to membrane filtration in the membrane filtration step to obtain permeated water. Then, microalgae are cultured in the liquid A containing the permeated water in the culturing step. Thereby, microalgae can utilize a low molecular weight nitrogen component that can be more easily used as a nutrient component. Therefore, the growth of microalgae is further promoted.

In the method for culturing microalgae, a culture component mixing step of mixing the permeated water obtained by the membrane filtration step and the culture components of microalgae can be further performed. In the method for culturing microalgae, a solid-liquid separation step of separating a mixture of microalgae and liquid cultured in the culture step into liquid and microalgae can be further performed.

In the method for culturing microalgae, a sterilization step of sterilizing the permeated water is further performed, and in the culturing step, in the liquid containing the permeated water that has been sterilized in the sterilization step. It is preferable to culture microalgae.
The sterilization step is preferably performed after the culture component mixing step. That is, in the sterilization step, it is preferable to perform sterilization treatment on an aqueous solution obtained by mixing permeate and microalgae culture components in the culture component mixing step.
By carrying out the sterilization step, since the microalgae are cultured in the liquid A containing the permeated water after sterilization in the culture step, there is an advantage that the adverse effect of the microorganisms on the growth of the microalgae can be more reliably suppressed. is there. Therefore, there is an advantage that microalgae can be propagated more sufficiently.

In the method for culturing microalgae, the liquid after culturing the microalgae in the culturing process is recovered, and a liquid recovery process is further performed in which the recovered liquid is mixed with wastewater that is water-treated in the water treatment process, In the treatment step, the liquid after culturing the microalgae in the culturing step is also preferably treated with water.
The liquid after culturing the microalgae in the culturing step contains a growth inhibitory component generated from the microalgae along with the growth of the microalgae. When the liquid containing the component is water-treated by the activated sludge method or the anaerobic treatment in the water treatment step, at least a part of the growth inhibiting component is decomposed by the activated sludge method or the anaerobic treatment, and the growth inhibiting component can be reduced. Therefore, in the liquid recovery process, the liquid after culturing the microalgae in the culturing process is recovered, and in the water treatment process, the recovered liquid is treated with water, thereby adversely affecting the growth inhibition components of the microalgae in the culturing process. Can be suppressed.

Although the microalgae culture facility and the microalgae culture method of the present embodiment are as described above, the present invention is not limited to the microalgae culture facility and microalgae culture method illustrated above. .
Moreover, the various aspects used in the culture | cultivation equipment and culture | cultivation method of a general microalga can be employ | adopted in the range which does not impair the effect of this invention.
That is, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims. Further, the scope of the present invention is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

For example, in the method for culturing microalgae in the above embodiment, a culture component such as ethanol, amino acid, or saccharide such as glucose (glucose) is added to the mixing tank 4, but the method for culturing microalgae of the present invention is such It is not limited to embodiment, For example, you may add a culture component to the culture tank 2a.

In addition, the method for culturing microalgae of the present invention may add brewed liquor, wort, sake lees, molasses, yeast extract, protein, etc. to the mixing tank 4 or the culture tank 2a. By culturing microalgae in the presence of these substances, microalgae can be more efficiently grown. The yeast extract is obtained by destroying the cell wall of yeast with heat, or obtained by destroying the cell wall of yeast with an enzyme.

In addition, the microalgae culture facility of the above embodiment is configured to send the cultured liquid to the water treatment device by the liquid recovery pipe 8, but the microalgae culture facility of the present invention is such a It is not limited to the embodiment. For example, the microalgae culture facility of the present invention further comprises a culture device and a solid-liquid separation device, and another type of microalgae is cultured in the culture device provided separately and cultured. You may comprise so that a mixture with a liquid may be isolate | separated into a micro algae and a liquid with the solid-liquid separator provided separately. Further, the liquid after culturing microalgae in the above embodiment may be configured to be sent to a culture apparatus separately provided by the liquid recovery pipe 8. Moreover, you may comprise so that the liquid isolate | separated with the solid-liquid separator provided separately may be sent to the above-mentioned water treatment apparatus 3 and / or the filtration tank 1a.
In the culture facility for microalgae having the above-described configuration, the cultured liquid sent to the culture device separately provided by the liquid recovery pipe 8 is a nutrient component that is not required for culture of microalgae in the culture device 2, or It contains nutrients that could not be used in the cultivation of microalgae in the culture device 2. Therefore, different types of microalgae that grow using these as nutrient components can be cultured in a separately provided culture apparatus. Thus, according to the characteristics of various kinds of microalgae, the nutrient components contained in the wastewater can be efficiently decomposed by using the liquid after the culture.

The microalgae cultivation facility and the microalgae cultivation method of the present invention can be used in applications such as health foods, pharmaceuticals, feeds, chemicals, and fuels for microalgae that store organic substances such as hydrocarbons and polysaccharides in cells. In order to utilize, it can use suitably.

1: membrane filtration device, 1a: filtration tank, 1b: membrane unit,
2: culture apparatus, 2a: culture tank, 2b: lighting equipment,
3: water treatment device, 3a: aeration tank, 3b: aeration tube,
4: Mixing tank, 4a: Stirrer,
5: Solid-liquid separator,
6: Piping for extracting microalgae,
7: Liquid extraction piping,
8: Pipe for liquid recovery,
9: disinfection device,
10: culture component storage tank, 11: detection sensor, 12: permeate extraction pipe,
20: culture equipment,
A: Liquid, B: Light.

Claims (6)

1. A membrane filtration step of obtaining permeated water that has permeated through the filtration membrane by membrane filtering waste water containing at least one of nitrogen and phosphorus, and a culture step of culturing microalgae in the liquid containing the permeated water A method for culturing microalgae to be performed.
2. Prior to the membrane filtration step, a water treatment step of water treatment of the wastewater by an activated sludge method or anaerobic treatment is further performed, and the wastewater treated in the water treatment step is subjected to membrane filtration in the membrane filtration step. Item 4. The method for culturing microalgae according to Item 1.
3. Further performing a sterilization step of sterilizing the permeated water, and in the culturing step, culturing microalgae in a liquid containing the permeated water that has been sterilized in the sterilization step. Item 3. The method for culturing microalgae according to Item 1 or 2.
4. A membrane filtration device for obtaining permeated water that has permeated through a filtration membrane by membrane filtration of waste water containing at least one of nitrogen and phosphorus, and a culture device for culturing microalgae in a liquid containing the permeated water Equipped with microalgae culture equipment.
5. Furthermore, the water treatment apparatus which water-processes the said waste_water | drain by an activated sludge process or anaerobic treatment is provided, It is comprised so that the waste_water | drain treated with this water treatment apparatus may be sent to the said membrane filtration apparatus. Microalgae culture equipment.
6. Furthermore, it comprises a sterilization apparatus for sterilizing the permeated water, and is configured to send the permeated water that has been sterilized by the sterilization apparatus to the culture apparatus. A culture facility for microalgae as described in 1.
   

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