JPH03219820A - Breeding apparatus - Google Patents

Abstract

PURPOSE:To enable the practical closed-system breeding by using an apparatus composed of a breezing water tank, an ozone treatment unit, an active carbon unit and a circulation unit for breeding water and removing troubles due to residual oxidizing products in usage of ozone. CONSTITUTION:The subject apparatus is equipped with a breeding water tank 1 containing a breeding water consisting of sea water or a mixed water composed of sea water and fresh water and having breeding objects bred therein; an ozone treatment unit (ozone reactor 6 and ozone generator 7) for ozone treatment of the breeding water; an active carbon unit 8 containing active carbon and capable of removal of oxidizing products contained in the breeding water subjected to ozone treatment by the ozone treatment unit 6; and a circulation unit 2 for the breeding water capable of making the breeding water flow out from the breeding water tank 1, supplying the flown out breeding water to the active carbon unit 8 through the ozone treatment unit 6 and returning the breeding water flown out from the active carbon unit 8 to the breeding water tank 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rearing device, particularly a device for rearing and cultivating aquatic animals such as fish and shellfish using artificial means.

[Conventional technology]

Since Japan is completely surrounded by the sea, the fishing industry has been flourishing for a long time. However, it is well known that the amount of fish caught has decreased dramatically in recent years due to environmental pollution, overfishing, and problems in territorial waters, making it difficult to secure fishing grounds.

To solve these problems, fish farming is becoming more popular. The aim is to efficiently produce fish by sealing off areas such as quiet bays, lakes, and rivers with nets, and feeding and administering chemicals in a planned manner. However, this kind of cultivation and fishing also causes problems of environmental destruction. In other words, the problem is that leftover food that has settled on the seabed and metabolites excreted by fish contaminate the surrounding water area.

For this reason, some methods have been put into practice in which a breeding aquarium is installed on land and water is brought in for cultivation. According to this method, it is possible to install wastewater purification equipment, which not only significantly solves the problem of environmental pollution, but also
Rational cultivation using various industrial techniques becomes possible.

Closed system breeding, which is a further development of this idea, is attracting attention. This system is equipped with an advanced water purification system, which minimizes the amount of water used for rearing, thereby minimizing the amount of wastewater produced.

If this technology is developed, it will not only eliminate environmental pollution, but also enable systematic production regardless of location, stable supply of fresh seafood, and economical temperature control. As a result, there are many benefits such as a richer variety of fish to raise and increased production, and we can expect the development of a new fishing industry.

Many of the water purification devices used in such closed system rearing systems follow conventional water treatment technology as they are, and are based on filtration devices using sand, etc., and some have added disinfection devices. There are some. There are not necessarily many cases where disinfection is being carried out, but when it is, it is often disinfected with chlorine-based chemicals, and relatively new methods such as ultraviolet light and ozone are being used or being considered in some cases.

FIG. 9 is a configuration diagram showing an example of a rearing device conventionally used in aquariums, as described in, for example, "Aquaculture and Water" Volume 1 (Scientis Publishing, 1987), P. 111. In the figure, 1 is a breeding tank in which breeding fish are present, 2 is a breeding water circulation pump that circulates the breeding water in the breeding tank 1, 3 is a sand filtration device that purifies the breeding water, and 4
The blower 15 for supplying oxygen is an aeration device that diffuses the air sent from the blower 4 into the breeding water.

The breeding water in the breeding aquarium 1 whose water quality has deteriorated due to metabolites of the breeding fish and residues of food is sent to the sand filtration device 3 by the circulation pump 2, where suspended solids are removed and solids adhering to the sand surface are removed. The microorganisms present in the aquarium remove and purify dissolved contaminants such as organic matter and ammonia nitrogen, and the aquarium is returned to the aquarium 1 again. On the other hand, the blower
4 is for supplying oxygen necessary for the survival and growth of fish.The air sent from the blower 4 is diffused into the rearing water through the aeration device 5, so that oxygen is supplied to the rearing water. Supplied. If ingredients that cannot be purified accumulate during breeding and the quality of the water deteriorates, making it impossible for breeding to continue, fresh water is replenished or replaced.

As another conventional example, disinfection using a chlorine-based agent may be performed in addition to the above example. In this case, disinfection is generally performed in front of the aquarium. As mentioned above, ultraviolet light and ozone are sometimes used as a disinfection method instead of chlorine-based chemicals.

[Problems to be solved by the invention] Conventional circulation-type rearing equipment is configured as described above and has a certain purification function, but it is necessary to increase the amount of feeding and cultivate as densely as possible. There has not yet been anything that can be put to practical use in practical breeding, which requires high levels of contamination. A major reason for this is the infection of farmed fish.

That is, in the conventional example shown in FIG. 9, there is no disinfection means, so if pathogenic bacteria invades the breeding aquarium 1 for some reason, the fish being kept may become infected. Disinfection is necessary to prevent the spread of disease, and chlorine-based agents are often used as water disinfectants. However, since this has residual properties and is highly toxic to farmed fish, the amount added is limited, and in many cases it is not possible to produce a sufficient disinfecting effect. Ultraviolet disinfection using an ultraviolet disinfection device has the advantage of having no residual toxicity, but there are problems such as dirt on the lamp surface of the UV irradiation lamp, decreased effectiveness due to decreased UV transmittance due to deterioration of water quality, and short lamp life. As a practical device used for this purpose, there are problems in terms of reliability and maintenance.

Compared to chlorine-based chemicals, ozone has stronger disinfecting power and less residual power (decomposes into oxygen molecules), and unlike chlorine-based chemicals, ozone has the effect of oxidizing and decomposing pollutants, so it can be kept in a closed system. It has favorable properties for purification in equipment. However, if the breeding water is seawater or contains seawater, the toxicity of residual oxidizing products produced by the reaction between bromide ions present in seawater and ozone becomes a problem, and as a result, chlorine-based As with drugs, there was the problem of residual toxicity.

When considering the above problems comprehensively, it is difficult to abandon the disinfection and purification functions of ozone for breeding in closed systems, and if the problem of residual oxidizing products when using seawater as breeding water can be solved. , it is thought that breeding in a closed system will be a major step toward realization. Residual oxidative products can be easily removed by adding a reducing agent, but using a reducing agent is not practical in terms of stability and maintenance.

This invention was made to solve the above-mentioned problems, and it is possible to practically remove residual oxidizing products when ozone is used, and even if it is removed (oxidizing products (On the other hand, it also acts as a disinfectant.) As a whole, it is possible to remove pathogens and prevent their reproduction, and it is also a closed system that allows for practical rearing of targets with low resistance, such as larvae, without changing the rearing water. The purpose is to provide breeding equipment for this type of animal.

Additionally, if biological treatment fails, the concentration of ammonia nitrogen, which is highly toxic to fish, may increase; It is an object of the present invention to provide a closed system rearing device using ozone, which allows stable decomposition of ammonia nitrogen and prevents accumulation of nitrogen components.

Furthermore, by synergistically combining ozone treatment, foam separation treatment, and activated carbon treatment, it is an object of the present invention to provide a rearing device that can purify rearing water only by physical and chemical treatment without using biological treatment. .

[Means to solve the problem]

The breeding device according to the invention described in claim (1) includes a breeding tank,
Consisting of an ozone treatment device, an activated carbon device, and a breeding water circulation device, the breeding water consisting of seawater or a mixture of seawater and fresh water is circulated between them, and the ozone treatment device is arranged in the direction of flow of the breeding water. was installed upstream of the activated carbon device (the breeding tank is located at the most upstream position).

The breeding device according to the invention described in claim (2) includes a breeding tank,
Consisting of an ozone treatment device, an activated carbon device, and a breeding water circulation device, the breeding water consisting of seawater or a mixture of seawater and fresh water is circulated between them, and the ozone treatment device is arranged in the direction of flow of the breeding water. is installed upstream of the activated carbon equipment, and the concentration of ozone injected into the circulating water (breeding water) to be ozonated by the ozone treatment equipment is at least as high as the ammonia nitrogen concentration contained in the circulating water. It is controlled so that it is 5 times or more.

In addition, the breeding device according to claim (3) divides the circulating water flowing out from the breeding tank into two parts, one passes through the ozone treatment device, and the other bypasses the ozone treatment device, and then the ozonated circulating water is obtained. and is configured such that the divided circulating water flows into the activated carbon device, and is controlled so that the amount M of the divided circulating water flowing into the ozone treatment device is ammonia nitrogen concentration x M ≦ ozone consumption ÷ 5. It is.

The breeding device according to the invention described in claim (4) includes a breeding tank,
It consists of an ozone treatment device, an activated carbon device, and a breeding water circulation device, in which breeding water consisting of seawater or a mixture of seawater and freshwater is circulated in series between them, and ozone is added to the breeding water in the flow direction. A treatment device is installed upstream of the activated carbon device, and a foam separator is installed in the circulation path.

Further, in the breeding device according to the invention described in claim (5), in the breeding device according to the invention described in claim (4), the foam separator is integrally provided with the ozone treatment device, and this integrated device is It also serves as a bubble column for ozone treatment.

In the breeding apparatus according to the invention described in claim (6), the water to be treated by the foam separator can be introduced from a plurality of locations in the circulation path.

In addition, the breeding device according to the invention described in claim (7) further includes a breeding water circulation path in which a foam separator is added to the breeding water tank, the ozone treatment device, the activated carbon device, and the breeding water circulation device. It is equipped with a filtration device.

[For production]

The invention as claimed in claim (1) is achieved by utilizing new facts obtained through detailed studies on ozonation of seawater and activated carbon treatment of ozonated seawater, and through detailed breeding experiments of larval fish in a closed system. discovered the practical effectiveness of combining ozone treatment and activated carbon treatment for closed system rearing, and eliminated the drawbacks of ozone treatment. That is,
Bromine ions contained in seawater (approximately 60m in natural seawater)
g/E) refers to the literature Ozone; Science and Engineering (Ozone: 5science and
Engineering) Volume 6 (1984) P
As described in P. 103-114, it was conventionally thought that hypobromite ions and bromate ions are produced by reacting with ozone. 4 These ions also act as disinfectants, but they are toxic to fish and persistent, so ozone is not used for disinfecting or purifying breeding water that uses seawater or water containing seawater. As mentioned above, it could not be used.

However, the present inventors have found, albeit indirectly, that the oxidizing products produced by ozonation of seawater are different from the above-mentioned oxidizing products that were conventionally thought. That is, the oxidizing products of seawater caused by ozonation were easily removed by contact with activated carbon, but the ability of activated carbon to remove reagents containing hypobromite and bromate ions was orders of magnitude lower. This is because the. For example, under the condition that the space velocity and SV are 50 hr,
Comparing the removal rates of oxidizing products when ozonated seawater and the reagents bromine water and potassium bromate aqueous solution were treated with activated carbon, they were 100.4% and 8%, respectively. This is not only a new finding that goes against conventional wisdom, but also has extremely important meaning in the following respects. In other words, this shows that the oxidizing products obtained from seawater ozonation treatment are extremely active, and if the appropriate amount of ozone injection and reaction time are secured, it has a more effective effect on disinfection and purification of pollutants. suggests. Moreover, its easy removal by contacting with activated carbon means that the activated carbon equipment required for this purpose requires only a small volume. More importantly, it was found that the removal of oxidizing products by activated carbon is not just adsorption, but a chemical reaction that returns the bromine ions to their original form. This suggests that activated carbon acts not just as an adsorbent but as a catalyst; activated carbon has a longer effective lifespan, and since there is no consumption of bromide ions, it can be easily and stably removed. It is shown that.

Applying these new facts, the aquarium water is first purified and disinfected by ozonation, then treated with a small amount of activated carbon to remove residual oxidizing products, and then returned to the aquarium to remove residual oxidizing substances. problems are easily eliminated. moreover,
Even if the disinfectant is removed by this method, it is possible to prevent disease infection of fish kept in a closed system, and the quality of the water used for breeding can be easily and stably maintained without replacing the water.

Furthermore, in a purification flow in which activated carbon treatment is performed after ozone treatment, it has been found that ammonia can be easily decomposed into nitrogen molecules if the ozone treatment satisfies predetermined conditions. The invention described in (3) has been achieved. That is, when seawater is treated with ozone, ozone is decomposed relatively quickly, but as described above, stable oxidizing products remain even after the ozone treatment. This is the bromine ion contained in seawater (approximately 60mg/in natural seawater).
It was thought that l) reacts with ozone to produce hypobromite ions and bromate ions, but as mentioned above, the inventors have discovered that this is not the case and that they are different chemical species. revealed. As a result of further various considerations,
It was found that when seawater containing ammonia is treated with ozonation and then treated with activated carbon, the ammonia is apparently converted into nitrogen molecules. The mechanism can be schematically expressed as follows.

Ozone + Br-→oxidizing product oxidizing product dried ammonia activated carbon→nitrogen molecules +Br That is, ozone+ammonium activated carbon→nitrogen molecules Since bromide ions do not appear to be involved, there is no consumption of them. If the amount of oxidizing products is small compared to the amount of ammonia present, the ammonia will be regenerated in the above process, so the ozone injection rate becomes an important factor.

In this invention, the ammonia nitrogen concentration contained in the circulating water is measured, and the amount of ozone injected into the circulating water is adjusted so that the ozone concentration is at least 5 times the ammonia nitrogen concentration contained in the circulating water. to ensure that ammonia is easily decomposed into nitrogen molecules.

Furthermore, the inventions described in claims (4) to (7) have been made based on the following idea. That is, as a result of studying purification of rearing water in a closed circulation rearing device, we arrived at the following idea.

In other words, the requirements that aquaculture water must meet are: - The absence of pathogenic microorganisms; - The concentration of toxic substances to fish is below the permissible level; and - Comprehensive water quality indicators such as BOD and COD are adequate for fish habitat. There are three things that can be mentioned: being below a level that does not become a hindrance. Satisfactory rearing cannot be achieved if any one of these is lacking, but ■ and ■ are complementary; for example, if ■ is sufficiently satisfied, even if ■ is somewhat poor, it is tolerated. On the other hand, if ■ is not fully satisfied, the condition of ■ must be severe.

The above-mentioned problem (■) in closed breeding equipment is the ammonia released by the breeding subjects themselves. Ammonia is highly toxic to fish, and according to the inventor's experiments, it is about 1.0 mg/42 in young fish that are 2 to 3 months old after hatching, and 0.5 n+g/! in smaller larvae. It is known that even at low concentrations, or even lower, it can cause hypersensitivity to stimulation and a state where appetite is drastically reduced. In normal purification equipment, ammonia and BOD are removed by biological treatment, but these are done by anaerobic and aerobic microorganisms, so in breeding equipment where the water to be purified is in an aerobic state, , it can be inferred that it is difficult to maintain the balance from the above viewpoint.

The inventor of the present invention believes that it is rational to perform (1) and (2) in separate processes, and only through physicochemical treatments, while achieving (1), and in order to achieve this, ozone treatment, Foam separation, ozone treatment and activated carbon treatment are organically combined. Its effect will be explained below.

If the cumulative amount of ozone injected into the total breeding water is increased, such as by relatively increasing the amount of ozone injected into the purified circulating water for breeding water that has been contaminated to some extent with organic matter, the foamability of the breeding water will increase. By foaming this by aeration, etc., and discharging the resulting stable foam from the system, contaminating organic components can be efficiently removed. As the amount of ozone injected increases, the concentration of residual ozone and oxidative products increases accordingly, and if the fish are returned to the aquarium as is, their toxicity becomes a problem, but these can be easily removed by activated carbon treatment. In other words, when bromine ions are present in service water, oxidizing products are produced by the reaction between them and ozone, and if the concentration is greater than a predetermined amount relative to the coexisting ammonia concentration,
Ammonia nitrogen is converted to molecular nitrogen. Generally, in order to always maintain this condition, excess oxidizing products are often produced, but these can also be easily removed by the activated carbon treatment as described above. It goes without saying that ozone also acts as a disinfectant.

If the foamability differs at the inlet or outlet of each device in the purification circulation system, an even higher organic matter removal effect can be obtained by providing an independent foam separator and separating the foam at an optimal position and amount of aeration.

Ozone plays a central role in the second invention, but if the required amount becomes excessive, it is effective to install a filtration device with a biological treatment function.

In this way, ozone plays the three roles of removing organic matter, denitrifying, and disinfecting by promoting the foam separation effect, and the harmful effects thereof can be easily and effectively removed by activated carbon treatment.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A breeding apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a rearing apparatus according to a first embodiment of the present invention. In the figure, ■ is a breeding tank,
2 is a circulation pump (breeding water circulation device), 3 is a filtration device,
4 is a blower and 15 is an aeration device. 6 is an ozone reaction device, and 7 is an ozone generator. The ozone reaction device 6 and the ozone generator 7 constitute an ozone treatment device.

8 is an activated carbon device, and 9 is a pH adjustment device. Filtration device 3
has the function of removing solid matter and the function of removing ammonia nitrogen through biological treatment.

Sand filtration is usually cheaper and more practical.

Next, the operation will be explained. Breeding water polluted by fish metabolism, excretion, etc. in the breeding aquarium 1 is transferred to a filtration device 3 by a circulation pump 2, where floating solids are removed and organic matter, ammonia nitrogen, etc. are dissolved through biological treatment. Contaminant components are removed. This treated water then enters the ozone reactor 6, comes into contact with the ozone-containing gas supplied from the ozone generator 7, and is disinfected, and a portion of the pollutant components are also oxidized. As described above, when the water used is seawater, oxidizing products are generated during the ozone treatment process. The amount of ozone supplied is determined by taking into account the amount of pollution load caused by breeding density, breeding stage, amount of feeding, etc., and the degree of biological treatment. This treated water is disinfected and purified while flowing through the ozone reactor 6, piping, etc. with an appropriate residence time, and then enters the activated carbon device 8. There, most of the remaining oxidizing products are removed very reliably and stably, and some of the polluting components are also removed. Therefore, even if the amount of ozone injection is excessive,
There is no risk of ozone and oxidizing products leaking and causing problems in breeding. The oxidizing products are also converted back to bromide ions. The amount of activated carbon used here may be less than the amount used in conventional water treatment. The activated carbon-treated water from which the disinfectant has been removed is finally adjusted to a predetermined pH using a pH adjustment device 9, and then returned to the breeding aquarium 1 for repeated circulation.

Note that ozone injection into the above-mentioned circulating water is normally performed continuously during the circulation, but may be intermittently depending on the status of the pollution load related to the growth stage of the fish, the amount of feeding, etc. Further, as the filter bag N3, a filtration method using a filter medium such as sand or anthracite is suitable, but a combination of other filtration and biological treatment may be used. In addition, breeding tank 1
should be covered to prevent contamination by falling bacteria, light conditions (illuminance) should be maintained to suppress algae growth, and the structure should be simple so that there are few areas where biofouling occurs inside. desirable. By doing so, the effects of the present invention are further emphasized.

Next, the experiment and rearing results will be explained.

Breeding experiments were carried out using the breeding apparatus of the second invention, one with only ozone treatment removed, and one with only activated charcoal removed, using specimens of oysters, large crabs, and flounders just after hatching, in addition to the second invention.

In the system without activated carbon, oxidative products measurable by iodometry were detected in the breeding water after several hours, and the larvae were wiped out. This shows that even very low levels of oxidative product accumulation make breeding impossible in a closed circulatory system.

Comparison results between the rearing apparatus according to this example and the rearing apparatus except for ozone treatment were as follows. The typical experimental conditions are 300 U ivy breeding tank 1.
Freshly hatched larvae were put into the tank, the activated carbon volume was IO liters, the circulating water rate was 6 liters/min, and no exchange with fresh seawater was performed during the experiment. The ozone treatment conditions in the breeding apparatus according to the present invention were such that approximately 10 grams of ozone was continuously injected per cubic meter of breeding water per day, and the residence time of the ozone reaction was set to 2 minutes. This does not mean that these conditions are optimal.

The oxidizing products produced by ozone were completely removed by a smaller amount of activated carbon than is used in conventional water treatment. Furthermore, despite the small amount of activated carbon, the removal ability was maintained for a long period of time. Since the bromine ion concentration in the circulating water was almost unchanged from the initial value of approximately 601 ng/e,
The mechanism by which activated carbon removes oxidizing products is reduction to bromide ions rather than adsorption, indicating that activated carbon has a catalytic effect. This ensures that a sufficiently effective and stable removal is maintained over a long period of time even with small amounts of activated carbon. As a result of the experiment by Madai, 75
Within days, it had grown to 11 centimeters in length. During this period, the growth conditions were good and the animal always had a good appetite. None of the fish were infected with typical pathogenic bacteria or diseases during the breeding period. On the other hand, in a system without ozone treatment, 35
A day later, infection with Vibrio parahaemolyticus was observed. The production amount per liter of the breeding tank after rearing for -75 days was 2700 fish/m3 in the system according to the present invention, and a satisfactory production amount was obtained. Production volume in a system without ozone treatment is 11
00 fish/m3, which was less than half.

The quality of the water in breeding tank I during the breeding period was maintained at a good level. The water quality items for which the effects of ozone were particularly noticeable were chromaticity, SS, sediment in the aquarium, and bacterial density in the water. There was a difference. Additionally, biofouling and algae growth in the aquarium were almost completely suppressed. COD and TOC
There was no significant difference in organic matter concentration indicators such as It is noteworthy that even after ozonation and activated carbon treatment to remove residual oxidizing products, the entire circulatory system was purified as described above and there was no disease infection. because,
By paying the above-mentioned consideration to the aquarium, at least the residual disinfectant concentration in the aquarium will be below the detection limit, and even if the concentration is low enough not to interfere with breeding, the general bacterial count will be at a low level. This is because the outbreak of disease could be prevented as a result.

Incidentally, although filtration and p ) l J adjustment are essential in a practical device, these are not essential conditions for the effects of this invention to be exhibited. Further, if the pollution load is small, a simple filter is sufficient as a filtration device, and pH adjustment is not necessary.

By the way, when actually rearing them, biological treatment sometimes went awry, and the concentration of ammonia nitrogen sometimes increased. Ammonia nitrogen is highly toxic to fish, and if the concentration rises even slightly, fish become hypersensitive to stimulation and have an extremely low appetite, and if the concentration exceeds a permissible limit, they will die. Strict control of biological treatment can avoid such problems, but if the target is
This is a practical problem if the pollution load changes drastically and if the malfunction of the equipment causes a fatal failure that cannot be recovered.

Figure 2 shows the second part of this invention that can also solve such problems.
FIG. 2 is a configuration diagram showing a breeding device according to an embodiment of the present invention. In FIG. 2, 11 is an ammonia concentration sensor, and 12 is a control device that controls the ozone concentration to be equal to or higher than a predetermined value based on the ammonia concentration. The ammonia concentration sensor 11 and the control device 12 constitute a control means.

Next, the operation will be explained.

Breeding water polluted by fish metabolism, excretion, etc. in the breeding aquarium 1 is transferred to a filtration device 3 by a circulation pump 2, where floating solids are removed and soluble organic matter is removed by microorganisms attached to the filter carrier. is purified. Depending on the operating conditions of the filtration device 3, if an anaerobic region is created in the filtration tank, ammonia can also be removed there; however, in this embodiment, the filtration device 3
It does not necessarily require an ammonia removal function.

However, if this function is added, it becomes possible to reduce the amount of ozone consumed in the ozone treatment described below.

The filtered water then enters the ozone reactor 6. Therefore, it reacts with a predetermined amount of ozone, and in addition to denitrifying ammonia, which is the objective, disinfection and removal of organic matter are performed. At this time, if the amount of oxidizing products generated in the ozone reactor 6 is small compared to the amount of ammonia present, the ammonia is regenerated, so the amount of ozone generated from the ozone generator 7 is reduced. become an important element. Figures 3 and 4 are characteristic diagrams showing the ozone injection amount and residual ammonia nitrogen concentration for different seawater, and both figures show that the ammonia nitrogen concentration before ozonation is at least 5 times or more, preferably 10 times or more.
It can be seen that ammonia regeneration can be suppressed by injecting an amount of ozone that more than doubles the ozone concentration. In reality, the amount of ozone generated from the ozone generator 7 is
Based on the amount of circulating water and the ammonia concentration measured by the ammonia concentration sensor 11, the amount of 5 times the amount of ammonia nitrogen (effective value)
The above is calculated by the control device 12, and the command is further transmitted to the ozone generator 7 and set by the control device attached thereto. In practice, such control is not necessarily necessary for reasons described later. Products including oxidizing products are present in the ozonated water, and if the ozonated water is returned to the breeding aquarium 1 as it is, their toxicity will cause damage to the farmed fish. However, in this case, the ozonated water is introduced into the activated carbon device 8 after a suitable residence time, where toxic oxidizing products and the like are removed, as well as some organic substances. F(
The bromine ions are regenerated. Therefore, there is no need to replenish bromide ions in the circulatory system. As mentioned above, it must be noted that if the amount of ozone injection is insufficient, ammonia will be regenerated during this process and the denitrification effect will disappear. The activated carbon treated water is finally adjusted to a predetermined pH using a pH adjuster 9.
After being adjusted to H, the circulation of returning to the breeding tank 1 is repeated.

In actual breeding, ammonia concentration must be maintained at a low level except in special cases. On the other hand, various substances that react with ozone coexist in breeding water, and it is also important to remove these substances with ozone. Therefore, in most cases, the mass-produced ozone necessary for denitrification is injected. For this reason, the above-mentioned control is not necessarily necessary during steady operation.

However, if the amount of feeding is increased or if biological treatment is involved, the ammonia concentration may rise rapidly, so in order to monitor and respond to abnormalities, ammonia concentration measurement and ozone concentration are necessary. With control, stable production can be ensured.

Next, the experiment and rearing results will be explained.

Denitrification according to this invention was extremely rapid. In other words, when we intentionally stopped ozone injection in an experiment to raise young larvae, the ammonia concentration in the rearing water began to increase within a few hours, and after 10 hours, striped patterns appeared on the body of the larvae.
The baby became irritable and stopped eating. When ozone injection was restarted, the ammonia concentration decreased significantly after several hours, and the above symptoms disappeared.

Note that the filter device 3 in the above embodiment is effective in reducing the amount of ozone required for the present invention, and is not essentially necessary for denitrifying ammonia. Furthermore, although the pH adjustment device W9 is necessary because it is often indispensable for breeding in a closed system, it is also essentially unrelated to the denitrification of the present invention.

FIG. 5 is a configuration diagram showing a rearing device according to a third embodiment of the present invention. In the figure, IO is a branch valve (branching means) that branches the circulating water flowing out from the filtration device 3. Further, 12a is a control device (control means) that controls the amount of branching. The overall operation is similar to that shown in Figure 2, but
Treated water from the filtration device 3 is introduced into a branch valve IO, where it is branched into a portion that enters the ozone reactor 6 and a portion that bypasses it and is introduced into the outlet piping of the ozone reactor 6. The former reacts with a predetermined amount of ozone in the ozone reaction device 6, and in addition to denitrifying ammonia, which is the objective, disinfection and removal of organic matter are performed. Oxidizing products are present in ozonated water due to reactions with bromide ions in seawater. This ozonated water is mixed with filtered water that has not been ozonated, and after a suitable residence time is introduced into the activated carbon unit W8. During this residence time, the amount of circulating water is disinfected by the action of the oxidizing products remaining in the ozonated water. If the residence time due to piping is short, a retention tank may be provided. The branching ratio of the branching described above is set in consideration of the amount of ozone consumed in the ozone reactor 6 and the ammonia nitrogen concentration of the inflowing circulating water. That is, the branch valve IO is controlled so that the amount M of circulating water flowing into the ozone treatment device after division satisfies the following: ammonia nitrogen concentration×M≦ozone consumption ÷5. For example, if an amount of ozone exceeding the capacity of the ozone generator 7 is required, the amount of branching introduced into the ozone reactor 6 may be lowered to meet the above conditions, and measures such as temporarily limiting the amount of feeding may be taken. . These settings are performed by the ammonia concentration sensor 11 and the control device 12a. The following operations are the same as the embodiment shown in FIG.

In addition, in the rearing device according to the first embodiment, when it is operated properly, the rearing device has a certain purification performance, but sometimes the biological treatment goes out of order and the water quality suddenly deteriorates. This may worsen and make breeding difficult.

Furthermore, if the pollution load increases rapidly due to increasing the amount of feeding, etc., the biological treatment function may not be able to keep up with it, and as a result, stable rearing with high productivity may not be possible. This is the fate of equipment that includes biological treatment.

The rearing device shown in FIG. 6 is the fourth aspect of this invention, which was developed as a result of repeated rearing experiments in a completely closed system and repeated studies on how to rationally purify rearing water in a closed system.
FIG. 2 is a configuration diagram showing a breeding device according to an embodiment of the present invention. In FIG. 6, 13 is a waste ozone treatment device that decomposes excess gas phase ozone, 14 is a foam tank (foam separator) that receives foam, and I5 is an air diffuser that miniaturizes air bubbles. In this embodiment, the ozone reaction device 6 also serves as a foam separator.

Next, the operation will be explained. The breeding water in the breeding tank 1 is first introduced into the ozone reaction device 6 by the circulation pump 2. The introduced water is disinfected by the ozone-containing gas from the ozone generator 7 coming into contact with the bubbles made micronized by the air diffuser 15, and the pollutant components are oxidized and purified. Depending on the type of pollutant components, ozone oxidation may only change the molecular form. Excess gas phase ozone in the ozone reactor 6 is decomposed in the waste ozone treatment device 13 and then released into the atmosphere. In the water treated in this way, if the water in which surplus ozone remains is seawater or water containing seawater, the reaction between bromide ions contained in the seawater and ozone is generated. oxidative products remain. These are highly toxic to fish. The ozonated water is then introduced into an activated carbon device 8, where ozone and oxidizing products are removed, as well as some pollutant components, and usually passed through a pH adjustment device (not shown).
The cycle of returning the fish to the breeding tank is repeated. As already mentioned, activated carbon can effectively remove oxidizing products generated during ozonation of seawater.

When the above circulation is repeated, the cumulative amount of ozone injected into all the water increases, and the water becomes foamy. In rearing equipment under normal conditions, this stage is reached within a few hours after feeding. At this stage, a foam layer is formed in the upper space of the ozone reactor 6, which is a bubble column. The foam formed here contains a high concentration of organic contaminant components, and the foam layer receives this in the layer 14 and discharges it to the outside of the thread after the foam breaks, thereby purifying the circulating water.

When surplus ozone is discharged from the foam layer from the tank 14, the foam layer is connected to the waste ozone treatment device 13, and the gas phase ozone after the foam is broken is removed.

When the water used is seawater or water containing seawater, the effects of the present invention can be more effectively exerted by combining denitrification technology using a combination of ozone treatment and activated carbon treatment. In other words, if the amount of ozone injected into purified circulating water satisfies predetermined conditions, denitrification becomes possible, and the ammonia concentration in the water can be maintained at a low level, resulting in a reduction in the appetite of animals even if the accumulated concentration of organic matter is high. They become voracious and can increase the amount of food they feed. As a result, higher concentrations of organics are tolerated, resulting in easier foaming and foam separation. In this way, ozone treatment is effective in both denitrification and improving foaming properties, and if used effectively, it becomes possible to promote cultivation without replacing water.

In a rearing experiment in which 50 taifish with a body length of about 10 centimeters were placed in a 300-liter breeding aquarium 1, it was found that it was possible to raise them for at least 60 days with a 100% survival rate. Almost no microorganisms were observed on the surface of the activated carbon, proving that the water quality necessary for breeding can be maintained even without biological treatment.

FIG. 7 is a configuration diagram showing a breeding device according to a fifth embodiment of the present invention, and in FIG. 7, 16 is a foam separator;
17 is a branch control device. The operation is basically the same as the fourth embodiment shown in FIG. 6, but the difference is that the ozone treatment device and the foam separator 16 are separated. The explanation of the operation is the same as that already explained, but the branch control device 17
This allows the processing order of the breeding tank, foam separation, ozone treatment, and activated carbon treatment to be changed arbitrarily. A bubble column is practical as the foam separator 16, and the amount of foaming is controlled by adjusting the amount of air fed.

By doing so, foam can be separated at a purification position where foam is likely to be formed, and the amount of air supplied for foam formation can be appropriately set, so that the foam separation effect can be further exhibited.

FIG. 8 is a configuration diagram showing a rearing device according to a sixth embodiment of the present invention. In the figure, 18 is a blower and 19 is an aeration device. The basic operation is the same as the fifth embodiment shown in FIG. 7, but the difference is that a sand filter device 3 is added.

In the embodiments shown in FIGS. 6 and 7, purification by filtration and biological treatment was not included in the ashes, but by adding such purification, ozone consumption can be reduced. Even in the unlikely event that biological treatment fails, ozone treatment and foam separation treatment are guaranteed.

In each of the above embodiments, the foam layer is provided in only one tank 14, but the water to be treated by the foam separator may be taken from multiple locations in the circulation path. Furthermore, if the foamability differs at the inlet or outlet of each device in the purification circulation system, an independent foam separator may be provided to separate the foam at an optimal position and amount of aeration, thereby achieving even higher organic matter removal effects.

(Effects of the Invention) As described above, according to the invention set forth in claim (1), seawater or a mixture of seawater and freshwater is passed between the breeding aquarium, the ozone treatment device, the activated carbon device, and the breeding water circulation device. The breeding equipment was constructed in such a way that the breeding water was circulated, and the ozone treatment device was installed upstream of the activated carbon device with respect to the flow direction of the breeding water. By making full use of ozone, which has excellent disinfection and purification properties, even when breeding using seawater or water containing seawater, it is possible to prevent the occurrence of diseases without changing the water, and to prevent the occurrence of diseases without the need for troublesome maintenance and management. This has the effect of realizing productivity and providing a practical rearing device.

Furthermore, according to the invention described in claim (2), the amount of ozone injected into the breeding water by the ozone treatment device is adjusted so that the ozone concentration is at least 5 times the ammonia nitrogen concentration contained in the breeding water. As a result, the ammonia concentration in the rearing water can be easily maintained at a low level without having to rely on biological treatment or troublesome management in contrast to closed system rearing equipment that uses ozone. It has the effect of allowing stable breeding.

According to the invention described in claim (3), the rearing water flowing out from the rearing aquarium is divided into two parts, one of which passes through the ozone treatment device, and the other of which bypasses the ozone treatment device.
It is configured so that it mixes with ozonated breeding water and flows into the activated carbon device, and the amount M of breeding water that flows into the ozone treatment device after division satisfies ammonia nitrogen concentration x M ≦ ozone consumption ÷ 5. Therefore, claim (2)
Similar to the invention described in ), the ammonia concentration in breeding water can be easily maintained at a low concentration without any troublesome management.

Further, according to the invention described in claim (4) or claim (5), since the foam separator is installed in the circulation path, the amount of ozone injection can be freely set to increase the foamability of the breeding water. Foam separation has the effect of allowing stable and highly productive rearing without biological treatment or replacement with fresh water.

According to the invention as set forth in claim (6), the water to be treated by the foam separator can be taken from a plurality of locations in the circulation path, thereby increasing the effect of removing organic matter.

Moreover, according to the invention described in claim (7), since the sand filter device is added, the ozone consumption can be reduced without deteriorating the overall function.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a rearing device according to a first embodiment of the present invention, FIG. 2 is a block diagram showing a rearing device according to a second embodiment of the present invention, and FIGS. 3 and 4 are different from each other. A characteristic diagram showing the relationship between the amount of ozone injected into seawater and the residual ammonia nitrogen concentration. Fig. 5 is a configuration diagram showing the rearing device according to the third embodiment of the present invention. A configuration diagram showing a rearing device according to an embodiment, FIG. 7 is a configuration diagram showing a rearing device according to a fifth embodiment of the present invention,
FIG. 8 is a block diagram showing a breeding apparatus according to a sixth embodiment of the present invention, and FIG. 9 is a block diagram showing a conventional breeding apparatus. 1 is a breeding tank, 2 is a circulation pump, 3 is a filtration device, 4 is a professional "7-15 is an aeration device, 6 is an ozone reaction device, 7 is an ozone generator, 8 is an activated carbon device, 9 is a pH adjustment device, 1
0 is a branch valve, 11 is an ammonia concentration sensor, 12.12
a is a control device, 13 is a waste ozone treatment device, 14 is a foam tank, 15 is an aeration device, and 16 is a foam separator. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (7)

[Claims] (1) A breeding aquarium having breeding water made of seawater or a mixture of seawater and fresh water in which a breeding subject is reared, an ozone treatment device for ozonating the breeding water, and activated carbon; an activated carbon device for removing oxidizing products contained in the breeding water that has been ozonated by the ozone treatment device; A breeding device comprising: a breeding water circulation device that supplies the breeding water to the activated carbon device and returns the breeding water flowing out from the activated carbon device to the breeding tank. (2) A breeding aquarium having breeding water made of seawater or a mixture of seawater and fresh water in which a breeding subject is reared, an ozone treatment device for treating the breeding water with ozone, and activated carbon; an activated carbon device for removing oxidizing products contained in the breeding water that has been ozonated by the ozone treatment device; a breeding water circulation device that supplies water to an activated carbon device and returns the breeding water flowing out from the activated carbon device to the breeding tank;
The ozone concentration in the rearing water that is ozonated in the ozone treatment device is at least 5 % of the ammonia nitrogen concentration in the rearing water flowing into the ozone treatment device.
A breeding device comprising: control means for instructing the ozone treatment device to inject twice the amount of ozone. (3) A breeding aquarium having breeding water made of seawater or a mixture of seawater and fresh water in which a breeding subject is reared, an ozone treatment device for ozonating the breeding water, and activated carbon; an activated carbon device for removing oxidizing products contained in the breeding water that has been ozonated by the ozone treatment device; a breeding water circulation device that supplies water to an activated carbon device and returns the breeding water flowing out from the activated carbon device to the breeding tank;
The breeding water flowing from the breeding aquarium to the ozone treatment device is divided into two, one of the divided breeding water is supplied to the ozone treatment device, and the other breeding water is used as the breeding water flowing out from the ozone treatment device. a branching means for merging, and a control means for controlling the value obtained by multiplying the amount of one of the divided rearing water by the ammonia nitrogen concentration in the rearing water to one-fifth or less of the ozone consumption in the ozone treatment device. A breeding device equipped with (4) A breeding aquarium having breeding water made of seawater or a mixture of seawater and fresh water in which a breeding subject is reared, an ozone treatment device for treating the breeding water with ozone, and activated carbon; an activated carbon device for removing oxidizing products contained in the breeding water that has been ozonated by the ozone treatment device; a breeding water circulation device that supplies water to an activated carbon device and returns the breeding water flowing out from the activated carbon device to the breeding tank;
A breeding device comprising, in a circulation path of the breeding water that circulates through the breeding water tank, the ozone treatment device, and the activated carbon device, a foam separator that discharges foam generated from the breeding water to the outside. (5) The breeding device according to claim (4), wherein the foam separator is provided integrally with the ozone treatment device and also serves as a bubble column for ozone treatment. (6) The breeding device according to claim (4), wherein the water to be treated by the foam separator can be taken from a plurality of locations in the circulation path. (7) Claim (4) in which a sand filter device is installed in the circulation path
) to (6).