JP7406776B1 - aquaponics system - Google Patents

Abstract

[Problem] To provide an aquaponics system and aquaculture/cultivation method that can reduce the size of the biological filtration device, increase the nitrogen source for crops, and minimize the need for new water supply by reducing backwashing as much as possible. do. [Solution] An aquaponics system that includes an aquaculture tank 2 for cultivating aquatic organisms and a hydroponic cultivation section 3 for cultivating crops using hydroponics, and that produces both marine products and agricultural products by circulating circulating water within the system. 1, the hydroponic cultivation section 3 is provided downstream of the circulating water of the aquaculture tank 2 and directly connected to the aquaculture tank 2, and continues to supply water containing excrement and leftover food from the aquaculture tank 2 for a predetermined period. The cultivation section 3 is equipped with an adjustment tank 6 for growing organic matter decomposing microorganisms existing in nature to form a plant rhizosphere, and for adjusting the pH upstream in the direction in which the circulating water of the hydroponic cultivation section 3 flows. In step 6, the pH is adjusted depending on the agricultural products cultivated in the hydroponic cultivation section 3. [Selection diagram] Figure 3

Description

The present invention relates to an aquaponics system.

Conventionally, ammonia and nitrite derived from excrement and leftover food of aquatic organisms are nitrified by microorganisms to nitric acid, which is less toxic to fish, and the nitric acid can be used as fertilizer (mainly nitrogen N, phosphorus P, and potassium K). Aquaponics systems are known that produce both marine products and agricultural products by cultivating them in parallel.

For example, in Patent Document 1, in a media bed for the hydroponic cultivation section of an aquaponics system in which the aquaculture division cultivates aquatic organisms and the hydroponic cultivation division cultivates agricultural products, water supplied from the aquaculture division is used. a septic tank that purifies water, a solution intermittent device that discharges water until it reaches a second water level when the vertical water level in the media bed reaches a first water level, and a water absorbing sheet from the bottom in the vertical direction. , a cultivation section including a root-prevention water-permeable sheet and a culture medium, and a media bed in which the first water level is set at the position of the water-absorbing sheet is disclosed (Patent Document 1 claims (See claim 1 within the scope of , paragraphs [0018] to [0095] of the specification, and FIGS. 1 to 10 of the drawings, etc.).

Further, Patent Document 2 includes a cultivation tank 100 for cultivating plants Pt and a cultivation tank 200 for cultivating fish Fs, and water is circulated between the cultivation tank and the cultivation tank 200. The cultivation tank includes a first drain port 210 with a valve located at a first height and a second drain port 220 located at a second height higher than the first height, and the cultivation tank is used for cultivating plants. The cultivation and aquaculture system includes a cultivation shelf 110 for draining water from a first drainage port 210 with a valve to a position lower than the cultivation shelf 110 in the cultivation tank 100, and a second drainage port 220. A cultivation and aquaculture system comprising a second pipe 2 for discharging wastewater from the culture tank to a position higher than the cultivation shelf in the culture tank, and a third pipe 3 for returning water flowing from the culture tank to the culture tank from the culture tank to the culture tank. 1000 has been disclosed (see claim 1 of the claims of Patent Document 2, paragraphs [0012] to [0023] of the specification, FIGS. 1 and 2 of the drawings, etc.).

However, the aquaponics system of Patent Document 1 describes that a media bed for a hydroponic cultivation section is purified by physical filtration and biological filtration (see paragraph [0030] of Patent Document 1, etc.). Furthermore, in the aquaponics system (cultivation and aquaculture system 1000) of Patent Document 2, it is described that a cultivation tank side filter is provided to purify the water flowing from the cultivation tank into the cultivation tank, and the water quality is purified by bacteria. (See paragraph [0017] of Patent Document 2, etc.).

In other words, as shown in Figure 9(a), in conventional aquaponics systems, the waste (mainly ammonia nitrogen, ^NH ₄ In this system, almost 100% of nitrate nitrogen (NO ₃ ^- ) is oxidized by bacteria, and then the plants absorb the nitrate nitrogen as a nitrogen source in the hydroponic culture section. Therefore, the current situation is that biological filtration devices (biological purification units) are about 2 to 3 times larger than the aquaculture tank capacity, and they are often reversed to prevent clogging with suspended matter during use. There was a problem in that physical purification treatment such as washing was required.

Furthermore, in order to reduce the burden on the biological purification unit and make the biological filtration device smaller, a physical filtration device is also installed as shown in FIG. 9(b). However, even if the biological filtration device can be made small-scale, a separate physical filtration device is required, which does not lead to miniaturization of the device as a whole, and there are problems in that the physical filtration device also requires purification treatment.

In addition, Patent Document 3 discloses a hydroponic cultivation and land aquaculture apparatus and a water quality management method that reuse the closed circulation rearing water for food-safe organic cultivation in hydroponic cultivation without discarding any of the rearing water. (See paragraphs [0005] to [0023] of the specification of Patent Document 3, FIG. 1 of the drawings, etc.).

However, the hydroponic cultivation, land-based aquaculture equipment, and water quality control method described in Patent Document 3 lack specific details, and it is possible to reuse the closed-circulation culture water for hydroponic cultivation without discarding it at all. It is unclear whether it is possible.

Further, as shown in FIG. 9, in the conventional aquaponics system, NO ₃ ^- is the only nitrogen source for crops grown hydroponically. It is known that when agricultural products containing NO ₃ ^- are ingested by the human body, they turn into harmful substances called nitrone amines, which are carcinogenic substances. Therefore, with agricultural crops, especially leafy vegetables, there is a problem in that care must be taken not to increase the concentration of NO ₃ ^- in the edible leaves.

Moreover, the water used in an aquaponics system should ideally be supplied only at the initial stage, and should be replenished only for the amount of water that evaporates, which is approximately 10% of the total annual water volume. However, in traditional aquaponics systems, in addition to the water that evaporates, there is a buildup of total solids (TS) that must be removed to remove accumulated solids and organic matter. Moreover, the water purification ability of the biological filtration tank alone is not enough; it is also necessary to perform backwashing, etc., in conjunction with physical filtration, and the current situation is that more than 100% of the water is replaced annually.

JP2018-42540A Patent No. 6979250 JP2022-6997A

Therefore, the present invention was devised in view of the above-mentioned problems, and its purpose is to reduce the size of biological filtration equipment, increase the nitrogen source for crops, and minimize work such as backwashing. The objective is to provide an aquaponics system that can reduce and minimize the need for new water supply.

The aquaponics system according to claim 1 includes an aquaculture tank for cultivating aquatic organisms and a hydroponic cultivation section for cultivating crops by hydroponics, and produces both marine products and agricultural products by circulating circulating water within the system. An aquaponics system in which the hydroponic cultivation section is provided downstream in the flow direction of the circulating water of the aquaculture tank and is directly connected to the aquaculture tank, and water containing excrement, urine and leftover food is supplied from the aquaculture tank for a predetermined period of time. The organic matter-degrading microorganisms that exist in nature are propagated in the hydroponic cultivation section to form a plant rhizosphere, and the hydroponic cultivation section is placed upstream in the direction in which the circulating water of the hydroponic cultivation section flows. A physical filtration device that is equipped with an adjustment tank that adjusts the pH according to the agricultural products grown in the cultivation section , and that physically filters solid matter by straining it out with a filter medium or filter; The present invention is characterized in that it further includes an anaerobic tank in which anaerobic microorganisms decompose organic matter in the wastewater washed away by backwashing .

The aquaponics system according to claim 2 is the aquaponics system according to claim 1 , which includes a septic tank equipped with aerobic granule sludge, and in the septic tank, wastewater containing solids generated during backwashing is collected. It is characterized by being purified and reused as circulating water.

The aquaponics system according to claim 3 is the aquaponics system according to claim 2 , in which the septic tank is equipped with an electrode plate in addition to aerobic granule sludge, and is capable of carrying out biological treatment and electrochemical treatment using a microbial fuel cell. It is characterized by doing.

According to the inventions according to claims 1 to 3 , since a plant rhizosphere is formed, the function of a physical filtration device or a biological filtration device can be replaced. Therefore, by reducing the size of the entire system by making the biological filtration device or the physical filtration device smaller, it is possible to improve the cultivation efficiency of aquatic organisms and the cultivation efficiency of agricultural products per site area of the system.

Furthermore, according to the inventions according to claims 1 to 3 , unlike conventional aquaponics systems, the nitrogen source for crops cultivated by hydroponics is mainly ammonia nitrogen NH ₄ ⁺ , so it is possible to There is little risk that the nitrate nitrogen NO ₃ ^- concentration in the edible leaves will increase, and there is also little risk that it will change into nitrone amines, which are carcinogenic substances, in the human body.

Furthermore, according to the inventions according to claims 1 to 3 , there is no need to provide a physical filtration device, so there is no need to remove solidified solids by backwashing, etc., and the amount of water that evaporates into circulating water is reduced. It is sufficient to replenish.

Furthermore, according to the inventions according to claims 1 to 3 , the pH can be adjusted according to the agricultural products cultivated in the hydroponic cultivation section using the adjustment tank, and a wide variety of agricultural products can be produced.
Further, according to the inventions according to claims 1 to 3, since the physical filtration device and the anaerobic tank are provided, solid matter in the circulating water can be filtered, and organic matter is decomposed by the anaerobic microorganisms in the anaerobic tank to produce methane gas and Products such as carbon dioxide can be produced. Furthermore, the sediment in the anaerobic tank can be reused as fertilizer for crops grown in the hydroponic cultivation section .

In particular, according to the invention according to claim 2 , since the septic tank is provided with aerobic granule sludge, wastewater containing solids (sludge) generated during backwashing is purified in the septic tank to the level of drinking water. It can be reused as circulating water.

In particular, according to the invention according to claim 3 , the septic tank is equipped with an electrode plate in addition to aerobic granule sludge, and performs biological treatment and electrochemical treatment using a microbial fuel cell, so nitrogen and phosphorus contained in wastewater are removed. It can be removed even more efficiently.

FIG. 1 is a schematic diagram showing the configuration of an aquaponics system according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing a situation in which leafy vegetables grown in the hydroponic cultivation section of the aquaponics system described above are harvested. FIG. 3 is a schematic diagram showing the configuration of an aquaponics system according to Modification 1. FIG. 4 is a schematic diagram showing the configuration of an aquaponics system according to a second embodiment of the present invention. FIG. 5 is a schematic diagram showing the configuration of an aquaponics system according to a third embodiment of the present invention. Figure 6 compares the water quality treatment of biological treatment using aerobic granule sludge (AGS) method and biological treatment using a combination of aerobic granule sludge (AGS) method and electrode plate, and shows the removal rate for each item. It is a bar graph showing. FIG. 7 is a schematic diagram showing the configuration of an aquaponics system according to a fourth embodiment of the present invention. FIG. 8 is a schematic diagram showing the configuration of an aquaponics system according to a modification of the fourth embodiment of the present invention. FIG. 9(a) is a schematic diagram showing the configuration of a conventional aquaponics system, and FIG. 9(b) is a schematic diagram showing the configuration of a conventional aquaponics system provided with a physical filtration device.

Hereinafter, one embodiment of the aquaponics system according to the present invention will be described in detail with reference to the drawings.

[First embodiment]
First, an aquaponics system 1 according to a first embodiment of the present invention will be explained using FIGS. 1 to 4. As shown in FIG. 1, the aquaponics system 1 according to the present embodiment includes an aquaculture tank 2 for cultivating aquatic organisms, a hydroponic cultivation section 3 for cultivating crops by hydroponics, and a hydroponic cultivation section 3 for cultivating organic nitrogen by nitrifying bacteria and A biological filtration device 4 that decomposes and purifies water using denitrifying bacteria and a sterilization device 5 that sterilizes pathogenic bacteria such as bacteria and viruses in the water are provided, and the organic matter generated in the aquaculture tank 2 is hydroponic by circulating water. The cultivation section 3 uses it as fertilizer to produce marine products and agricultural crops. Moreover, it is desirable that an adjustment tank 6 for adjusting pH is provided between the culture tank 2 and the hydroponic cultivation section 3. FIG. 1 is a schematic diagram showing the configuration of an aquaponics system according to a first embodiment of the present invention.

(culture tank)
Aquaculture tank 2 is an aquarium for cultivating aquatic organisms and their eggs, and is intended for cultivating aquatic organisms such as sturgeon (caviar) and other high-grade marine products, but it is also used for cultivating aquatic organisms such as sturgeon (caviar), etc. It is also possible to farm fish such as shrimp, crabs, crustaceans such as scallops, and cephalopods such as squid and octopus. Although it depends on the type of aquatic organisms to be cultivated, it is desirable to maintain the pH value of the aquaculture tank 2 around 6.8 to 7.5. It is preferable to provide sensors such as an oxygen sensor that measures the oxygen concentration of the water, and to maintain the temperature and oxygen concentration of the water through automatic control based on information obtained from these sensors. In addition, the code|symbol 21 is the automatic feeding device 21 which automatically feeds the aquatic creature in the culture tank 2 with food.

Furthermore, the culture tank 2 has conventionally been generally provided with an air pump that supplies sufficient oxygen into the water so that many aquatic organisms can be cultured. However, in the culture tank 2 according to the present embodiment, instead of aerating with an air pump, an MNB generator 20 (MNB: micro-nano bubble) that generates oxygen micro-nano bubbles is installed in the culture tank 2 to generate oxygen. We supply micro-nano bubbles. By supplying oxygen to the aquaculture tank 2 in the form of micro-nano bubbles, more oxygen dissolves in the water than when oxygen is supplied by a conventional air pump, so dissolved oxygen in the water increases and more aquaculture It is possible to grow living things. Moreover, the water in the culture tank 2 can be stirred by the pressure of the MNB generator 20 without aeration. By providing the MNB generator 20 in the culture tank 2 in this manner, costs such as piping, pumps, aeration, and electricity costs can be reduced.

In addition, supplying oxygen micro-nano bubbles in the aquaculture tank 2 allows aquatic organisms to take the oxygen micro-nano bubbles into their bodies together with the food when fed, allowing them to efficiently absorb oxygen into their bodies. At the same time, food can be digested and absorbed more efficiently. In addition, an environment with a sufficient supply of oxygen improves the immunity of aquatic organisms and reduces the risk of contracting diseases. What's more, micro-nano bubbles also have the effect of killing bacteria and viruses, so they are useful for preventing diseases in aquatic organisms.

Here, the term "micro-nano bubble" refers to a small bubble in size ranging from several tens of nanometers to micro-order (1 to 100 μm). In addition, methods for generating oxygen micro-nano bubbles include the ``swirling flow method,'' which creates oxygen bubbles by mixing oxygen gas and water and swirling them at high speed. ``Pressure dissolution method'' which creates oxygen bubbles by opening them all at once, ``micropore method'' which creates oxygen bubbles by applying pressure to oxygen gas and passing it through microscopic holes such as orifices, and cavitation using ultrasonic waves. An example is the ``ultrasonic method,'' which creates oxygen bubbles by causing oxygen gas in the water to expand. However, the method for producing oxygen nanobubble water is not particularly limited, and any method may be used as long as it can produce micronanobubble water containing microscopic oxygen gas on the micro order (1 to 100 μm).

(Hydroponic cultivation department)
As shown in Figure 2, the hydroponic cultivation section 3 uses a media culture method in which crops such as leafy vegetables are planted in a porous material (media bed) made of coconut fiber, vermiculite, etc. instead of soil. Specifically, it is a part where crops are grown using hydroponic cultivation using the DWC (Deep Water Culture) method. FIG. 2 is a schematic diagram showing a situation in which leafy vegetables grown in the hydroponic cultivation section 3 of the aquaponics system 1 are harvested.

Of course, hydroponic cultivation methods are not limited to the media culture method, but include the aeroponics method, which sprays a mist of water into the air to provide the roots with the necessary moisture and nutrients, and the aquarium in which the roots are soaked. The deep water culture (DWC) method uses an aeration device installed at the bottom to supply oxygen while soaking the roots, and the drip system (Drip system) uses water droplets to drip from the roots to provide the roots with the moisture and nutrients they need. It is also possible to use the Nutrient Film Technique (NTF) method, in which plants are placed on a board on a slope and a thin film of water is poured in to provide the roots with the necessary water and nutrients.

The biggest feature of the aquaponics system 1 according to the embodiment of the present invention is that, unlike conventional aquaponics systems, water is directly flowed from the aquaculture tank 2 into the hydroponic cultivation section 3, and organic matter is added to the media bed. The goal is to form a plant rhizosphere in which decomposing microorganisms (fungi) and plant roots coexist. Here, "directly" refers to supplying water that contains solid matter such as excrement such as excrement and leftover feed from aquatic organisms in the aquaculture tank 2 by directly flowing into the hydroponic cultivation section 3. As shown in FIG. 1, this also includes the case where an adjustment tank 6 is provided in the middle.

The formation of the plant rhizosphere is achieved by continuously supplying water containing excreta and leftover food for a specified period of 1 to 3 months, and by adjusting the water temperature and pH value to the appropriate level, which allows for the decomposition of organic matter that exists in nature. This is done by growing microorganisms on a media bed.

In this way, in the aquaponics system 1, the hydroponic cultivation section 3 is provided downstream in the flow direction of the circulating water of the aquaculture tank 2 and is directly connected to the aquaculture tank 2. Solid matter (organic matter) containing bacteria-containing excrement, leftover food, etc. flows into the hydroponic cultivation tank 3 and sinks. In addition, various proteins (enzymes) are secreted by plants into the plant rhizosphere (simply referred to as rhizosphere). In particular, the rhizosphere has high phosphatase activity secreted by plants, and this enzyme hydrolyzes phosphoric acid linked to organic matter, increasing the amount of phosphoric acid available for plant growth. Therefore, the rhizobacteria living in the rhizosphere increase the availability of nutrients in the organic matter in the hydroponic culture tank 3 while coexisting with the plants, thereby promoting the growth of the plants.

In addition, as shown in Figure 2, crops such as leafy vegetables grown hydroponically are harvested by taking them out from one end of the media bed, and the seedlings are planted in one rod of the media bed from the other end. Add and replace. By regularly harvesting and replacing crops in this way, it is possible to prevent the proliferation of harmful microorganisms and maintain a stable ecosystem of microorganisms that decompose organic matter. In addition, certain agricultural products can be harvested and shipped throughout the year regardless of the season.

Furthermore, in the aquaponics system 1, as described above, in the upstream aquaculture tank 2, oxygen micro-nano bubbles are supplied to the circulating water by the MNB generator 20. Oxygen micro-nano bubbles can remain suspended in water for long periods of time while undergoing Brownian motion, making it easier for oxygen to be absorbed by the roots of agricultural crops even from circulating water. For this reason, even in hydroponic cultivation, it is difficult for bacteria to occur in the water, and in this respect, a useful plant rhizosphere is formed, allowing the organic matter-degrading microorganisms to decompose organic matter and making it easier for crops to grow.

(biological filtration device)
The biological filtration device 4 is a device for purifying the quality of water circulating within the aquaponics system 1, and has the function of decomposing organic matter and nitrogen compounds using microorganisms attached to a carrier or filter medium. It is. The biological filtration device 4 is preferably a small-scale unit-type assembly that can be easily removed and changed depending on the number and growth balance of aquatic organisms such as fish and shellfish.

In the biological filtration device 4 according to this embodiment, in order to quickly cultivate a high-density microorganism group of nitrifying bacteria and denitrifying bacteria, which have a slow growth rate, microorganisms are attached to a carrier and then wrapped in a porous material for immobilization. An entrapping immobilization carrier is produced by applying the entrapping immobilization method. Specifically, in the biological filtration device 4 according to the present embodiment, nitrifying bacteria and denitrifying bacteria are attached to powdered activated carbon particles, and then fixed with a polymer to form cubic pellets with an average size of 3 mm x 3 mm x 3 mm. Organic matter and nitrogen compounds are decomposed using an entrapping immobilization carrier (microbial activated carbon immobilization carrier) on which a high-density group of microorganisms is immobilized. Here, high density (high concentration) refers to a group of microorganisms of about 2,000 to 30,000 mg/L. This microorganism concentration was measured by the concentration of MLVSS (mixed liquid volatile suspended solids). By using a three-phase fluidized biological purification unit that uses microorganisms (mainly nitrifying bacteria and denitrifying bacteria) as immobilized carriers, it has become possible to remove almost 100% of ammonia nitrogen and nitrite nitrogen. .

Microbial immobilization carriers used in conventional biological filtration devices using the binding immobilization method are suitable for water treatment containing high concentrations of ammonia nitrogen (approximately 100 to 600 mg/L); As shown in Figure 1, water containing very low concentrations of ammonia nitrogen (approximately 1 mg/L) cannot be used because the aquaponics system 1 becomes unstable due to a lack of nitrogen source necessary for the growth of microorganisms. There was a problem.

On the other hand, the biological filtration device 4 decomposes nitrogen compounds using an entrapping immobilization carrier (microbial activated carbon immobilization carrier) on which a high-density group of microorganisms is immobilized, so the nitrogen compounds are decomposed at high concentrations (100 to 600 mg/L). The aquaponics system 1 can be used not only under conditions of ammonia nitrogen at a low concentration (about 1 mg/L), but also stably under conditions of ammonia nitrogen at a low concentration (about 1 mg/L).

The biological filtration device 4 converts the extremely low concentration of residual ammonia nitrogen (NH ₄ ⁺ -N: about 1 mg/L or less) that could not be completely processed in the plant rhizosphere of the hydroponic cultivation section 3 into NO ₃ ^-. While it is decomposed, microorganisms such as nitrifying bacteria themselves also absorb ions such as NH ₄ ⁺ and NO ₃ ^- as well as PO ₄ ^- , K ⁺ , Ca ²⁺ and SO ₄ ^- as nutrients necessary for growth. Therefore, in the aquaponics system 1, water that has been purified to a level of water with a neutral pH value (such as tap water or underground water) returns to the aquaculture tank 2 again.

Note that this biological filtration device 4 can also be provided within the aquaculture tank 2 described above. By making the biological filtration device 4 into a plurality of small-scale unit-type aggregates as described above, it can be changed as appropriate depending on the area of the aquarium, the number of aquatic organisms reared, and the growth balance, and can correspond to the number of reared organisms and their growth. This is effective in that it allows stable operation of the aquaponics system 1. Furthermore, by making the biological filtration device 4 into a unit type, it is possible to incorporate a sterilization device 5, etc., which will be described later, into the biological filtration device 4, and one device can perform many roles.

(Sterilization device)
The sterilization device 5 includes a UV germicidal lamp that sterilizes bacteria and viruses in water by irradiating ultraviolet rays, an ozone generator that converts oxygen molecules into ozone using electric discharge, and a filter medium that contains silver and generates silver ions. It is a device that sterilizes harmful microorganisms in the water, including a sterilizing filter. As shown in FIG. 1, in the aquaponics system 1, in addition to decomposing nitrogen compounds etc. in the biological filtration device 4 described above, the sterilization device 5 sterilizes and removes bacteria and viruses that have a negative impact on the survival of aquatic organisms. The recycled water becomes clean purified water and returns to the aquaculture tank 2.

(adjustment tank)
The adjustment tank 6 has a function as a sump tank, automatically adjusting the pH value and water temperature within the tank, and also functions as a settling tank to remove suspended matter and fine particles from the water. As mentioned above, it is desirable for many aquatic organisms to maintain the pH value of the culture tank 2 at around 6.8 to 7.5, so by adjusting the pH and water temperature according to the crops being cultivated, it is possible to This is preferable in that it makes it possible to cultivate plants that are unique to each other.

For example, as shown in FIG. 3, by branching the circulating water from the culture tank 2, providing a plurality of hydroponic cultivation sections 3 and 3', and providing an adjustment tank 6 at each intermediate point, the plants to be cultivated can be The pH value of the water can be adjusted to the optimum value accordingly. For example, leafy vegetables are cultivated in the hydroponic cultivation section 3 using the DWC (Deep Water Culture) method, and water temperature etc. are grown in the other hydroponic cultivation section 3' using the general media culture method. This makes it possible to cultivate wasabi, which has a special cultivation environment. FIG. 3 is a schematic diagram showing the configuration of an aquaponics system 1' according to Modification 1 of the first embodiment.

(Physical filtration device)
In addition, as shown in FIG. 3, the aquaponics system 1' according to modification 1 includes physical filtration by straining out solid matter with a filter material or filter downstream in the flow direction of the circulating water of the biological filtration device 4. A physical filtration device 7 is provided. This physical filtration device 7 suppresses the growth of microorganisms in the water by removing suspended matter and particulates in the water using filter media such as shells, crab shells, and sand, as well as a substrate and a filter made of fine fibers such as polyester fibers. It has the function of maintaining good water quality. In particular, in the case of aquaponics plants for large-scale agricultural facilities, the hydroponic culture section 3 and biological filtration device 4 may not be able to completely process the solids, and the physical filtration device 7 physically removes solids, etc. It is desirable to filter dirt, pigments, and turbidity using a substrate.

(anaerobic tank)
As shown in FIG. 3, in the aquaponics system 1', the solids filtered by the physical filtration device 7 are washed away by backwashing and stored in the sump tank of the anaerobic tank 8. In this anaerobic tank 8, anaerobic microorganisms in the sump tank decompose organic matter to produce products such as methane gas and carbon dioxide. In addition, a precipitate is generated in the anaerobic tank 8 after decomposition, and this precipitate includes sludge containing excrement and dead bodies of microorganisms in the water. This sludge-containing sediment is reused as fertilizer for the crops grown in the hydroponic cultivation section 3.

According to the aquaponics system 1 according to the first embodiment of the present invention and the aquaponics system 1' according to the first modification example described above, a plant rhizosphere ecosystem is created in the hydroponic cultivation section 3, and the The plant rhizosphere can replace about 70% of physical and biological purification processes, reducing the need for conventional physical filtration devices and biological filtration. For this reason, by reducing the size of the entire system by making the biological filtration device and physical filtration device of conventional aquaponics systems smaller, the efficiency of cultivating aquatic organisms and cultivating agricultural products per unit area of the system can be improved. can be done.

Furthermore, according to the aquaponics system 1 and the aquaponics system 1', as shown in FIG. 1, unlike the conventional aquaponics system, the nitrogen source for crops grown by hydroponics is Since it is ammonia nitrogen NH ₄ ⁺ , there is little risk that nitrate nitrogen NO ₃ ^- concentration will increase in the edible leaves, and there is also little risk that it will change into nitrone amine, a carcinogenic substance, in the human body. In addition, crops can selectively absorb well-balanced nitrogen sources (NO ₃ ^- : NH ₄ ⁺ = 50 mg/L: 0.1 to 1.5 mg/L) from ammonia nitrogen NH ₄ ⁺ and nitrate nitrogen NO ₃ - ^. Therefore, a wide variety of crops can be cultivated.

Furthermore, according to the aquaponics system 1, there is no need to install the physical filtration device 7, so there is no need to remove solidified solids by backwashing etc., and the amount of water that evaporates is replenished into the circulating water. It's enough. Further, even when a physical filtration device 7 is provided as in the aquaponics system 1', water loss can be minimized because the water can be efficiently purified by the plant rhizosphere or the biological filtration device 4.

Furthermore, according to the aquaponics system 1 and the aquaponics system 1', the aquaculture tank 2 is equipped with the MNB generator 20 that generates micro-nano bubbles of oxygen. It is possible to dissolve more oxygen into the circulating water. Therefore, according to the aquaponics system 1 and the aquaponics system 1', dissolved oxygen in the circulating water increases, and more marine products and agricultural products can be produced. Furthermore, according to the aquaponics system 1 and the aquaponics system 1', the water in the aquaculture tank 2 can be stirred by the pressure of the MNB generator 20 without aeration, so an aeration facility is no longer required, and Costs such as necessary piping, pumps, aeration, and electricity costs can be reduced.

In addition, according to the aquaponics system 1 and the aquaponics system 1', after nitrifying bacteria and/or denitrifying bacteria are attached to powdered activated carbon particles, organic nitrogen is Because it decomposes and purifies ammonia nitrogen, it is possible to quickly grow a high-density microbial group of nitrifying bacteria and denitrifying bacteria, which have slow growth rates, and is stable even under conditions of low concentrations (about 1 mg/L) of ammonia nitrogen. The aquaponics system 1 can be operated in this way, and approximately 100% of the ammonia nitrogen and nitrite nitrogen that cannot be treated in the plant rhizosphere can be removed.

In addition, according to the aquaponics system 1 and the aquaponics system 1', the pH is adjusted in the adjustment tank 6 according to the agricultural products to be cultivated in the hydroponic cultivation section 3, so that the optimum water can be used according to the plants to be cultivated. The pH value can be adjusted to , making it possible to cultivate a variety of plants.

[Second embodiment]
Next, an aquaponics system 10 according to a second embodiment of the present invention will be described using FIG. 4. The aquaponics system 10 according to this embodiment differs from the aquaponics system 1' according to the above-mentioned modification 1 mainly in that the SBR (semi-batch system) equipped with aerobic granule sludge (AGS) Since the septic tank 9 of the sequencing batch reactor method is provided, this point will be explained, and the same components will be given the same reference numerals and the explanation will be omitted. FIG. 4 is a schematic diagram showing the configuration of an aquaponics system according to a second embodiment of the present invention.

The wastewater containing solid matter (sludge) generated during the backwashing of the physical filtration device 7 described above differs depending on the size of the filtration tank of the physical filtration device. Further, the amount of waste water generated by backwashing is approximately 50% of the total volume of water in the filtration tank. Therefore, in the aquaponics system 10, by providing an SBR method septic tank 9 equipped with aerobic granule sludge (AGS), wastewater containing solids (sludge) generated during backwashing can be removed as shown in FIG. In this way, the water is purified to the level of industrial water in the septic tank 9 and reused as circulating water.

The septic tank 9 includes aerobic granular sludge (AGS). Here, granule sludge is sludge in which bacteria adhere to each other at a high density and coagulate using polymers (EPS) produced outside cells instead of carriers as footholds to form self-granules. Moreover, although anaerobic granule sludge is generally used as granule sludge, aerobic microorganisms also form granule sludge. Furthermore, a configuration in which aerobic granule sludge and an electrode plate are combined, that is, a microbial fuel cell (MFC) that combines biological treatment and electrochemical treatment may be used. For the electrode plate, titanium and/or nickel, that is, either one or both of titanium and nickel is used (hereinafter, and/or refers to either one or both).

Figure 6 shows the removal rate for each water purification item by biological treatment of this aerobic granule sludge (AGS) and the removal rate for each water purification item by a microbial fuel cell that combines aerobic granule sludge (AGS) and an electrode plate. A bar graph comparing the rates is shown. As shown in Figure 6, ammonia nitrogen (NH ₄ -N), nitrite nitrogen (NO ₂ -N), and total solids (TS) are the main components of aerobic granule sludge (AGS). Both biological and electrochemical treatments using a microbial fuel cell that combines aerobic granule sludge (AGS) and an electrode plate were able to remove 100% of the sludge. On the other hand, total nitrogen (TN) and total phosphorus (TP) are approximately 4% higher in biological/electrochemical treatment using microbial fuel cells than in biological treatment alone of aerobic granule sludge (AGS). The removal rate was high.

In this way, in the aquaponics system 10, the septic tank 9 removes ammonia, nitrous acid, solids, nitrogen, and phosphorus from the wastewater containing solids (sludge) generated during backwashing, purifying it to the level of drinking water. After the treatment, the water is sterilized by the sterilizer 5 and reused as circulating water. Further, the dregs generated in the septic tank 9 are mixed with rice husk ash, which is waste, and reused as media for the hydroponic cultivation section 3.

Further, the sediment generated in the anaerobic tank 8 of the aquaponics system 10 is reused as fertilizer for the crops grown in the hydroponic cultivation section 3, similarly to the aquaponics system 1'.

The sludge generated in the anaerobic tank 8 of the aquaponics system 10 is used as nutrients for microalgae. Microalgae absorb carbon dioxide through photosynthesis and are used to produce organic matter. Furthermore, the microalgae can be put into the culture tank 2 and used as food for aquatic organisms.

[Third embodiment]
Next, an aquaponics system 11 according to a third embodiment of the present invention will be described using FIG. 5. The aquaponics system 11 according to this embodiment differs from the aquaponics system 10 according to the second embodiment described above in the arrangement of the physical filtration device 7 and the anaerobic tank 8, and the arrangement of the biological filtration device 4 and sterilization. The point is that the device 5 is provided inside the culture tank 2. Therefore, the same configurations are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 5 is a schematic diagram showing the configuration of an aquaponics system according to a third embodiment of the present invention.

In the aquaponics system 11, the physical filtration device 7 is provided downstream of the hydroponic cultivation section 3, and the water purified by the physical filtration device 7 returns to the aquaculture tank 2. Wastewater containing solid matter (sludge) generated during backwashing of the physical filtration device 7 is decomposed by anaerobic microorganisms in the anaerobic tank 8, and then reduced to the water level in the septic tank 9, similar to the aquaponics system 10. The water is purified and reused as circulating water.

In the aquaponics system 11, a biological filtration device 4 is provided in the culture tank 2. By forming the biological filtration device 4 into a collection of multiple small-scale units, it can be changed as appropriate depending on the area of the aquarium, the number of aquatic organisms reared, and the growth balance. This is effective in that the system 11 can be operated stably.

Furthermore, in the aquaponics system 11, the biological filtration device 4 is of a unit type, so that a sterilization device 5, which will be described later, is also incorporated into the biological filtration device 4. Therefore, the installation space for the biological filtration device 4 and the sterilization device 5 can be omitted.

[Fourth embodiment]
Next, an aquaponics system 12 according to a fourth embodiment of the present invention will be described using FIG. 7. The aquaponics system 12 according to this embodiment is different from the aquaponics system 1 according to the first embodiment described above in that a plurality of aquaculture tanks 2, 2 are provided in multiple stages above and below, and different aquatic organisms are grown. The point is that they are cultivated. Therefore, the same configurations are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 7 is a schematic diagram showing the configuration of an aquaponics system according to a fourth embodiment of the present invention.

As shown in FIG. 6, in the aquaponics system 12 according to the fourth embodiment, it is assumed that shrimp are cultured in the upper culture tank 2, and crabs are cultured in the lower culture tank 2. In this way, by providing a plurality of culture tanks 2, 2, it becomes possible to culture a plurality of types of aquatic organisms that are difficult to grow in the same culture tank. Moreover, by providing the culture tanks 2 in two stages, upper and lower, the culture space can be reduced, and the production efficiency of marine products per site area is improved.

Also, like the aquaponics system 1, the aquaponics system 12 according to the fourth embodiment contains enteric bacteria such as E. coli and lactic acid bacteria from the fish in the aquaculture tanks 2 and 2 through a pump (PUMP). Water containing solid matter (organic matter) such as excrement and leftover food flows into the hydroponic cultivation tank 3 and sinks therein. Therefore, in the hydroponic cultivation section 3, a plant rhizosphere is formed in which the above-mentioned organic matter decomposing microorganisms (fungi) and plant roots coexist.

Further, in the aquaponics system 12, an aeration mechanism and a biological filtration device 4 are provided in the aquaculture tank 2, similarly to the aquaponics system 11 described above. Therefore, the area of each aquaculture tank 2 can be changed as appropriate depending on the number and growth balance of aquatic organisms, and stable operation of the aquaponics system 12 corresponding to the number and growth of aquatic organisms is possible. . In addition, the code|symbol 5 is the above-mentioned sterilization disinfection apparatus 5.

FIG. 8 is a schematic diagram showing the configuration of an aquaponics system 13 according to a modification of the fourth embodiment of the present invention. In the aquaponics system 13, a biological filtration device 4 and a sterilization device 5 are provided on the downstream side of the hydroponic culture tank 3, and purified water that has been filtered and sterilized by the biological filtration device 4 and the sterilization device 5 is used for aquaculture. It differs from the aquaponics system 12 in that it is configured to flow into tanks 2, 2.

According to the aquaponics systems 12 and 13, by providing a plurality of aquaculture tanks 2 and 2, it is possible to cultivate a plurality of types of aquatic organisms that are difficult to grow in the same aquaculture tank 2. Moreover, by providing the culture tanks 2 in two stages, upper and lower, the culture space can be reduced, and the production efficiency of marine products per site area is improved.

According to the aquaponics systems 10 to 13 (aquaponics systems 1, 1', 10, 11, 12, 13) according to the embodiments of the present invention described above, in addition to the above-mentioned effects, aerobic granules With the SBR method septic tank equipped with sludge (AGS), wastewater containing solids (sludge) generated during backwashing can be purified to the level of industrial water in the septic tank 9 and reused as circulating water. Therefore, all water other than water that evaporates in an artificial environment that is substantially similar to the natural environment and water that is absorbed by plants and the like can be reused.

In addition, according to the aquaponics systems 1 to 13 according to the embodiments of the present invention, the nitrogen sources (NH ₄ ⁺ and NO ₃ ^- ) required by each plant are selectively absorbed as nutrients. We have succeeded in cultivating many more plants than with an aquaponics system. With conventional systems, it is possible to mainly cultivate leafy vegetables, but with the aquaponics systems 1, 1', 10, and 11 according to the embodiments of the present invention, strawberries and melons that preferentially absorb NH ₄ ⁺ can be cultivated. , cucumbers, etc. can be cultivated by adding extra nutrients. Many plants preferentially utilize NH ₄ ⁺ when ammonium ions (NH ₄ ⁺ ) and nitrate ions (NO ₃ ^- ) coexist.

Furthermore, since plant roots are negatively charged, NH ₄ ⁺ tends to be attracted to the roots, but both ions are taken into the roots via transport carriers on the plasma membrane. NO ₃ ^- absorbed by plants is reduced to NH ₄ ⁺ and then assimilated, whereas NH ₄ ⁺ is assimilated as is when absorbed by crops.

Each type of nitrogen has its advantages and disadvantages, and the reaction to both types of nitrogen differs depending on the type of plant, environmental conditions (pH, temperature), growth stage, etc., so nitrogen application must be appropriate for cultivation. . When NO ₃ ^- and NH ₄ ⁺ are present at equal concentrations, which one is preferentially absorbed differs depending on the type of plant (vegetables or fruits). Plants that preferentially absorb NH ₄ ⁺ regardless of the culture medium are lettuce, strawberries, celery, melons, Japanese parsley, cucumbers, Japanese apricots, and Japanese chrysanthemums.

In addition, edamame, eggplant, and the like absorb NH ₄ ⁺ preferentially when the pH is high, and NO ₃ ^- and NH ₄ ⁺ almost equally when the pH is low. Spinach and Chinese cabbage preferentially absorb NO ₃ ^- regardless of the pH of the culture solution. On the other hand, there are green peppers and the like that preferentially absorb NO ₃ ^- when the pH is low, and preferentially absorb NH ₄ ⁺ when the pH is high.

Vegetables that preferentially absorb NH ₄ ⁺ are less susceptible to NH ₄ ⁺ inhibition, and conversely, vegetables that are more susceptible to NH ₄ ⁺ inhibition tend to preferentially absorb NO ₃ ^- . In other words, it is known that vegetable growth is often improved by using NH ₄ ⁺ and NO ₃ ^- in combination than by using NO ₃ ^- alone (All About Solution Cultivation, 2014). For example, in the case of hydroponic liquid fertilizer cultivation in a plant factory, if the NH ₄ ⁺ concentration is not too high, using NH ₄ ⁺ and NO ₃ ^- together will result in better growth than when the same concentration of nitrogen is supplied only with NO ₃ ^- . It is clear that things will get better. In addition, in conventional aquaponics systems, vegetables are currently grown by absorbing NO ₃ ^- as a nitrogen source.

Above, the aquaponics systems 1, 1', 10, 11, 12, 13 according to the embodiments of the present invention have been described in detail, but the embodiments described above or illustrated are all specific in carrying out the present invention. This is merely an illustration of one embodiment. Therefore, the technical scope of the present invention should not be construed as being limited by these.

1, 1', 10, 11, 12, 13: Aquaponics system 2: Aquaculture tank 20: MNB generator 21: Automatic feeding device 3, 3': Hydroponic cultivation section 4: Biological filtration device 5: Sterilization and disinfection Device 6: Adjustment tank 7: Physical filtration device 8: Anaerobic tank 9: Septic tank

Claims (3)

An aquaponics system that includes an aquaculture tank for cultivating aquatic organisms and a hydroponic cultivation section for cultivating crops using hydroponics, and that produces both marine products and agricultural products by circulating water within the system,
The hydroponic cultivation section is provided downstream of the aquaculture tank in the flow direction of the circulating water and is directly connected to the aquaculture tank, and water containing excrement and leftover feed is continuously supplied from the aquaculture tank for a predetermined period. In the plant, a group of organic matter-degrading microorganisms that exist in nature are multiplied and a plant rhizosphere is formed.
An adjustment tank is provided upstream in the direction in which the circulating water of the hydroponic cultivation section flows and adjusts the pH according to the agricultural products cultivated in the hydroponic cultivation section ;
A physical filtration device that physically filters solid matter by straining it out with a filter medium or a filter, and an anaerobic tank that uses anaerobic microorganisms to decompose the organic matter in the wastewater after washing away the solid matter filtered through the physical filtration device by backwashing. This aquaponics system is characterized by the following : Equipped with a septic tank with aerobic granule sludge,
The aquaponics system according to claim 1 , wherein in the septic tank, wastewater containing solids generated during backwashing is purified and reused as circulating water. The aquaponics system according to claim 2 , wherein the septic tank is equipped with an electrode plate in addition to aerobic granule sludge, and performs biological treatment and electrochemical treatment using a microbial fuel cell.

Images