JP7156674B2 - Aquaculture methods for marine organisms, aquaculture kits, aquaculture systems, and marine organisms cultured by such aquaculture methods - Google Patents

Description

The present invention secures an environment suitable for the growth of marine organisms or freshwater organisms such as sea cucumbers, sea urchins, fish and shellfish (hereinafter referred to as "marine organisms"), freshwater or seawater for growth (hereinafter referred to as "breeding A method of cultivating fish and shellfish that prevents contamination of the breeding water and suppresses the propagation of various bacteria even when sufficient feed is put into the water or excrement is discharged by marine organisms. Regarding.

As a technique for sterilization when cultivating marine organisms using seawater or the like, for example, Patent Document 1 (Method for cultivating marine fish and shellfish) describes an invention in which chlorine is used for sterilization.
Further, Patent Document 2 (open marine culture system and method for cultivating marine animals) describes an invention of sterilization with ozone.
In addition, Patent Document 3 (crustacean aquaculture system and method) discloses that the pH value of breeding water is maintained at about 8.2 by adding strongly alkaline seawater obtained by electrolyzing seawater to a breeding tank. A reconciling invention is described.
In addition, Patent Document 4 (Disease prevention of pufferfish) describes an invention of filtering and sterilizing with a filter.
Further, in Patent Document 5 (shellfish culture soil conditioner and shellfish culture method using the same), a soil conditioner for culture mainly composed of shellfish is sprayed on a farm to make the soil alkaline. An invention that makes
In addition, Patent Document 6 (waste water treatment method) discloses the use of powdered activated carbon or a flocculating agent for flocculation treatment.
In addition, Patent Document 7 (sewage purification device and circulation device) is characterized in that porous diatomaceous earth or the like is contained in a nonwoven fabric in a bent shape, and a flow path that has a filter effect and a filtration effect is provided. Disclosed is a sewage purification device, a sewage purification circulation device, and a technology for purifying sewage by decomposing microorganisms in sewage by attaching bacteria to fine pores of a porous material structure of diatomaceous earth or crushed wood. It is

Japanese Patent Application Laid-Open No. 2007-020501 Japanese Patent Publication No. 11-501524 JP-A-11-169011 Japanese Patent Application Laid-Open No. 2004-275020 JP-A-6-169664 JP 2004-275884 A JP 2010-234351 A

In the past, in order to avoid inconveniences such as oxidation of breeding water and breeding of various bacteria due to the use of feces of marine organisms after water supply and surplus food during feeding, seawater and fresh water put into aquaculture tanks were By sterilizing and replacing it every day, it was possible to suppress the growth and oxidation of various bacteria, but replacing all the seawater, etc. There are inconveniences such as increased labor and labor, and increased electricity costs for maintaining the temperature of a large amount of seawater at a temperature at which marine organisms and the like grow. For example, in winter, it is necessary to warm the seawater below 5°C, and in the summer, when the water temperature reaches 25°C, it is necessary to cool the seawater.

In addition, when replacing all the seawater, there is a risk of applying unnecessary stress to marine organisms due to changes in the temperature, composition, and pH value of the seawater when the aquaculture tank is emptied and after replacement. There was also In addition, the burden on the filter is heavy, and there is also the inconvenience that the expensive filter needs to be replaced frequently.
Alternatively, antibiotics have been used to sterilize aquaculture tanks, but in addition to being costly, antibiotics may not be used depending on the type and purpose of marine organisms, etc., as described later. was not a panacea.

In particular, in sea cucumber farming, the use of antibiotics is restricted by Japanese laws and regulations, and even if restrictions on the use of antibiotics were to be relaxed as in other countries, the use of antibiotics would not be possible. This is because their use is known to create resistant bacteria that propagate in the area, polluting the area.

Therefore, various countermeasures have been proposed to avoid such inconvenience.
For example, in Patent Document 1, before feeding marine fish and shellfish with feed organisms that serve as food, the feed organisms have a sterilization ability generated by electrolyzing seawater or dilute salt water, and the effective chlorine concentration is constant. A technique for feeding marine fish and shellfish after washing with electrolyzed water in the range of is disclosed.
However, even if the bait is sterilized, it is not possible to suppress the oxidation of sea water and the growth of various bacteria due to residual food and feces discharged by marine fish and shellfish. It has the drawback of being stagnant.

Further, Patent Document 2 discloses a method of sterilizing various bacteria in seawater using ozone. However, since residual ozone has an adverse effect on marine organisms, etc., it is necessary to add a suitable device to remove it, which is disadvantageous in that it requires considerably large-scale equipment and is costly.

Also, in Patent Document 3, by adding strongly alkaline seawater obtained by electrolyzing seawater, it is necessary to adjust the pH value of the breeding water so that it is maintained, so large-scale equipment for electrolysis is required. Also, there was the inconvenience that costs such as electricity bills increased due to the electrolysis of a large amount of seawater.
In addition, in order to avoid such inconveniences in terms of equipment, Patent Document 4 discloses a technique for removing various bacteria using a microfilter when supplying water. There is a problem that it is not possible to prevent seawater from being oxidized by feces and urine discharged by marine organisms.

In addition, in Patent Document 5, by spraying a soil improver for shellfish farming mainly composed of shells heat-treated at a temperature of 350 to 600 ° C. to a farm, calcium carbonate, which is the main component of shells, is eluted. By doing so, the effect of making the soil alkaline is promoted, and an invention is disclosed that has a favorable effect on the growth of shellfish. However, if this is used in a relatively small breeding tank, the degree of local alkalinity will increase, affecting the marine organisms themselves, and shells will sediment at the bottom of the tank, hindering the cleaning of the bathtub. There were inconveniences such as becoming

In addition, in Patent Document 6, it is necessary to directly add a powdery flocculant to the breeding water, which is troublesome and costly to spray the breeding water many times, and the flocculated impurities precipitate at the bottom of the aquarium, Due to inconveniences such as frequent cleaning and collection, it was difficult to use them in aquaculture tanks.
Therefore, it is conceivable to solidify the coagulant into a block and install it in the breeding water. could not be fully agglomerated and collected.

Moreover, in Patent Document 7, porous diatomaceous earth that exists in nature is fired as it is, so the aggregation action is not sufficient, and as a result, the decomposition and purification action by bacteria is also insufficient.

Therefore, in the present invention, while avoiding the above-mentioned inconveniences, without requiring large-scale facilities for purifying breeding water, an environment suitable for the growth of fish and shellfish is secured, and water for breeding or Even if enough food is put into seawater, impurities such as residual food, manure excreted by fish and shellfish, ammonia from manure, harmful heavy metal ions contained in seawater, bacteria and viruses, and their corpses, etc. To provide a low-cost and trouble-free method for cultivating fishes and shellfishes by preventing contamination of water, maintaining an appropriate breeding environment, and suppressing the propagation of various germs.

In addition, the silicon dioxide contained in volcanic ash such as Shirasu has the property of aggregating impurities, and it is used after being enhanced by a predetermined treatment (treatment such as activation) to raise marine organisms. The purpose is to purify the water and maintain a stable breeding system to increase the yield of marine organisms.

Silicon dioxide is also abundantly contained in so-called silicic acid plants such as rice, wheat, bamboo, corn, and sugar cane. Barley husk also contains about 5% silicon dioxide. The ash obtained by incinerating these at about 900 to 1500° C. contains silicon dioxide at a ratio of 90% or more. Rice husks, rice straw, and barley husks can also be used as raw materials for thermal power generation, and their ash, which is also an industrial waste, can be effectively used as a raw material in the present invention. It can also contribute to reducing the amount of industrial waste generated.

In order to achieve the above object, the first invention melts a raw material containing at least silicon dioxide and aluminum oxide at a temperature of 1600° C. or higher to produce a compound of silicon dioxide and aluminum oxide, and cools the compound. The rock-like block thus obtained is finely pulverized to obtain a powdery cohesive material, and a plurality of fine cavities are formed by foaming based on the powdery cohesive material. It is characterized by generating a block for impurity agglomeration.
In a second invention, the content ratio of silicon dioxide and aluminum oxide according to the first invention is the weight ratio of silicon dioxide and aluminum oxide in the entire raw material, and the ratio of silicon dioxide is 60 to 90% by weight, and aluminum oxide is 4.5 to 20% by weight, and the weight ratio of aluminum oxide to the total of silicon dioxide and aluminum oxide is 5 to 33%.
In a third invention, the impurity-aggregating block according to the first invention is obtained by dissolving the powdery cohesive material containing the compound of silicon dioxide and aluminum oxide in alkaline water having a pH value of 11 or more. A block for aggregating impurities is obtained by repeating a cycle of immersing the obtained colloidal solution of the compound in a colloidal solution adjusted to pH 7 to 8 and then drying at least once or more.
In a fourth invention, the impurity-aggregating block according to the second invention is obtained by dissolving the powdery cohesive material containing the compound of silicon dioxide and aluminum oxide in alkaline water having a pH value of 11 or higher. A block for aggregating impurities is obtained by repeating a cycle of immersing the obtained colloidal solution of the compound in a colloidal solution adjusted to pH 7 to 8 and then drying at least once or more.
A fifth aspect of the present invention establishes a cycle of impurity aggregation and decomposition by causing bacteria to settle in the plurality of fine cavities of the impurity aggregation block and decomposing the impurities aggregated in the fine cavities. Characterized by
A sixth aspect of the present invention comprises filtering means for removing microorganisms and bacteria in the breeding water of seawater or fresh water (hereinafter referred to as "seawater etc.") taken, and a breeding tank for storing the breeding water. An aquaculture system for marine organisms or freshwater organisms (hereinafter referred to as "marine organisms, etc."), comprising: means for supplying seawater or the like to the breeding tank; means for maintaining water flow in the breeding tank; , By installing one or more of the above-mentioned blocks for flocculating and decomposing impurities, in the breeding water of the breeding tank into which marine organisms, etc. are introduced, impurities such as excreta discharged by marine organisms, etc., and surplus food after feeding are aggregated. and an aeration supply means for supplying oxygen to the block for flocculating and decomposing impurities. It is characterized by suppressing oxidation or contamination of breeding water and breeding of various germs due to feces and urine.
A seventh invention is a step of melting a raw material containing at least silicon dioxide and aluminum oxide at a temperature of 1600° C. or higher to produce a compound of silicon dioxide and aluminum oxide, and cooling the compound to obtain a rock-like A step of finely pulverizing the block of to generate a powdery cohesive material, and using the powdery cohesive material, molding it into a predetermined shape and foaming so as to include a plurality of fine cavities. A method for manufacturing an impurity-aggregating block, comprising:
An eighth invention is the impurity-aggregating block manufacturing method according to the seventh invention, wherein the content ratio of silicon dioxide and aluminum oxide is the weight ratio of silicon dioxide and aluminum oxide in the entire raw material, and the ratio of silicon dioxide is 60 to 90% by weight, the ratio of aluminum oxide is 4.5 to 20% by weight, and the weight ratio of aluminum oxide to the total of silicon dioxide and aluminum oxide is 5 to 33%. do.
A ninth invention is obtained by dissolving a powdery cohesive material containing a compound of silicon dioxide and aluminum oxide in alkaline water having a pH value of 11 or higher in the method for producing an impurity-aggregating block according to the seventh invention. a step of repeating a cycle of immersing the impurity-aggregating block in a colloidal solution of a compound having a pH of 7 to 8 and then drying the colloidal solution at least once or more.
A tenth invention is the method for producing an impurity-aggregating block according to the eighth invention, wherein the powdery cohesive material containing the compound of silicon dioxide and aluminum oxide is dissolved in alkaline water having a pH value of 11 or more. a step of repeating a cycle of soaking the block for aggregating impurities in the colloidal solution of the compound obtained by the above method and adjusting the pH to 7 to 8, followed by drying, at least once or more. .
An eleventh invention is the method for producing an impurity-aggregating block according to any one of the seventh to tenth inventions, further comprising a step of fixing bacteria in a plurality of fine cavities of the impurity-aggregating block, It is characterized by establishing a cycle of impurity aggregation and decomposition by decomposing impurities aggregated in fine cavities.
A twelfth invention comprises filtering means for removing microorganisms and bacteria in the breeding water of seawater or fresh water (hereinafter referred to as "seawater, etc.") taken, and a breeding tank for storing the breeding water. A method for culturing marine organisms or freshwater organisms (hereinafter referred to as “marine organisms, etc.”), comprising the steps of supplying seawater or the like to the breeding tank, maintaining a water flow in the breeding tank, and , By installing one or more of the above-mentioned blocks for flocculating and decomposing impurities, in the breeding water of the breeding tank into which marine organisms, etc. are introduced, impurities such as excreta discharged by marine organisms, etc., and surplus food after feeding are aggregated. and the aeration supply step for the block for flocculating and decomposing impurities. It is characterized by suppressing oxidation or contamination of water and breeding of bacteria.
A thirteenth invention is a marine organism or the like cultured using the culture method according to the twelfth invention.
A fourteenth invention is silicon dioxide and aluminum oxide obtained by dissolving the powdery cohesive material according to the first invention in alkaline water having a pH value of 11 or more and adjusting the pH to 7 to 8. is a colloidal solution containing a compound of

In the aquaculture method, the aquaculture kit, or the aquaculture system using the aquaculture block such as the impurity aggregation block and the impurity aggregation/decomposition block according to the present invention, first, silicon dioxide contained in whitebait, volcanic ash, rice straw ash, etc. is used. Then, a cohesive material is produced by a predetermined process, and an aquaculture block is produced by solidifying the cohesive material into a block shape so as to include many fine hollow portions inside.
The aquaculture blocks are appropriately soaked in a solution of silicon or the like so that the fine cavities inside are coated with silicon dioxide, or bacteria are settled appropriately before being placed in the breeding water. By circulating breeding water containing an appropriate amount of oxygen, when breeding water contaminated with impurities such as feces and urine passes through the block, the breeding water comes into contact with the cohesive material to sufficiently aggregate the impurities. , the aggregated impurities can be decomposed by bacteria, and a constant aggregation action can be maintained for a long period of time without adding coagulant powder.

Experiments have shown that even if bacteria are allowed to grow in the breeding water, the impurities are suspended in the breeding water in the form of colloids, so that the bacteria can hardly capture and decompose the impurities.

In addition, while maintaining a stable breeding environment without inadvertently putting substances such as antibiotics and chlorine into the farming tank, the breeding water will be drained by residual feed and manure discharged by the marine organisms that are breeding. It has the effect of increasing the yield by providing a low-stress environment that does not give unnecessary environmental stress to reared marine organisms while preventing contamination and propagation of various bacteria.

As a result, for example, in the case of sea cucumber farming, about 500,000 eggs hatch from about 8 million eggs, and about 10 juvenile sea cucumbers with a size of 35 to 50 mm in the natural world. Even among those with good results, about 10,000 to 30,000 juvenile sea cucumbers with a size of 35 to 50 mm were born from about 8 million eggs. On the other hand, according to the aquaculture method of the present invention, there is an effect that it is possible to raise up to about 150,000, which is 5 to 15 times.

1] is a schematic diagram of the configuration of the aquaculture system 100 of the present invention. [FIG. shows a modification of the water supply and drainage method in the present invention. [FIG. 2] is a diagram showing an example in which a plurality of breeding tanks 150 are connected in parallel to a water storage unit 130 of the aquaculture system 100 of the present invention. 1] is a diagram showing the flow of the aquaculture process of the present invention. [FIG. 1 is a flow diagram showing a process for producing the powdered cohesive material of the present invention from a raw material such as silicon dioxide. 1] A diagram showing a flow of dissolving the powdery cohesive material of the present invention in water to generate a solution of silicon or the like. [FIG. 1] is a diagram showing a manufacturing flow of aquaculture blocks of the present invention. [FIG. [FIG. 2] A diagram for explaining the action and effect when the aquaculture block is used in breeding water. shows the change tendency (relative value) of the cohesion performance when the heating temperature and the produced compound are used as the cohesive material when the weight ratio of aluminum oxide to the total weight of silicon dioxide and aluminum oxide is 5 to 25. It is a thing. shows how the impurity agglomeration performance changes (relative values) depending on the mixing ratio of silicon dioxide and aluminum oxide when the heating temperature is 1600° C. or higher. is the effect of maintaining the water quality of the aquaculture system or It shows the difference in the relative effectiveness of marine life yields.

<Description of terms>
◇ Impurities include residual feed, manure discharged from fish and shellfish, ammonia generated from manure, harmful heavy metal ions contained in seawater, bacteria and viruses and their carcasses, and other substances harmful to the breeding of marine organisms. means ingredients.
◇ Shirasu means volcanic ash that contains a particularly large amount of vitreous silicon dioxide, unlike ordinary volcanic ash. Its composition is 30% plagioclase, quartz, and pyroxene, and the other 70% is amorphous. consists of vitreous. 70 to 80% of its composition consists of a glassy substance containing silicon dioxide as a main component, and contains about 10% aluminum oxide and about several% sodium oxide. In the natural state of Shirasu, the ratio of soluble portion of silicon dioxide is as low as about 25 to 30%, which is insufficient as a cohesive material in the natural state.
◇Activated silicon dioxide refers to silicon dioxide that has been made more water soluble by altering the surface properties of silicon dioxide. Note that the state in which silicon dioxide or the like is dissolved in water means a state in which, since it is fine particles, it is dispersed in water in a colloidal form.
◇ Zeta potential is an evaluation standard for the magnitude of static electricity or charge reaction/attraction between particles, and is an index that correlates with the strength of the action of particles such as impurities, such as dispersion, aggregation, or precipitation. Simply put, it is a property of the surface of a particle, and more specifically, it refers to the potential difference between the slip plane in the electric double layer and the portion sufficiently distant from the sea surface. The zeta potential of oxides such as silicon dioxide also depends on the pH value of the aqueous solution and other ions present in the aqueous solution, for example, if AL acoion (aluminum acoion) is present, the oxide (in this case, dioxide The absolute value and sign (polarity) of the zeta potential change when positively charged AL acoions chemisorb to the surface of silicon) with a ligand substitution reaction.
In the present invention, silicon dioxide such as shirasu and aluminum oxide are added at a constant ratio as a step for increasing cohesiveness (or zeta potential) without adding a water-soluble aluminum compound (e.g., aluminum sulfate, aluminum chloride, etc.) A compound of silicon dioxide and aluminum oxide is generated by a process of melting the material contained in (1) at a high temperature of 1600° C. or higher and used as a cohesive material.
◇ Impurity agglomeration block is a mixture of silicon dioxide and aluminum oxide in a predetermined weight ratio, which is heated to high temperature to form a compound, which is then finely pulverized and then foamed. A solidified object of a specified size. The shape of the block is a rectangular parallelepiped, which is suitable for installation and replacement, but is not limited to this.
◇ Impurity flocculation/decomposition block is a block for impurity flocculation with the added action of fixing bacteria and decomposing flocculated impurities.
◇Blocks for aquaculture means either or both blocks for agglomeration of impurities or blocks for agglomeration and decomposition of impurities.

Examples of the aquaculture system of the present invention are described below.
Sea cucumbers are only examples of animals raised in the present invention. Sea cucumbers and other echinoderms such as sea urchins, as well as fish, other marine organisms, and freshwater organisms (hereinafter referred to as "marine organisms, etc."). can also be applied to

1. Overall Flow of Aquaculture System of the Present Invention First, the overall flow of the aquaculture system of the present invention will be described with reference to FIG.
Eggs are appropriately collected from the parent sea cucumber and fertilized (step 400), and the collected fertilized eggs are attached to a corrugated plate (step 410).
The corrugated plate has 10 to 15 corrugated undulations in the longitudinal direction so that eggs can easily adhere to the corrugated plate. A corrugated plate made of resin or the like having a size of about 30×20 cm to about 40×30 cm can be used, and a plurality of plates are stacked vertically or horizontally and submerged in a breeding tank.

In this state, the water temperature is maintained at about 20° C. After about one day, the larvae hatch (step 420), become cystula stage larvae, swim out, and begin floating life. The larval stage is divided into multiple stages, and metamorphosis progresses through Auricularia larvae (early stage, late stage), Dryolaria larvae, and Pentacutura larvae, and individuals that metamorphose into juvenile sea cucumbers begin to appear around 14 days.
In this system, larvae about 10 days after hatching are collected (step 430), and raised in a breeding tank on which a plurality of cloth-made attachment beds are suspended (step 440).

Seaweed powder or the like is fed during breeding (step 450). Ingenuity is required.
After 180 days of breeding in a breeding tank (cloth) at a water temperature of 20 to 22° C., sea cucumbers grow to about 50 mm in size (step 460), which are collected (step 470) and dispersed in the ocean or the like. (Step 480).
Sea cucumbers that have grown to about 50 mm have strong vitality, and because they contain toxins such as holotoxins, they are repelled by other marine organisms. I know that.
After that, they naturally breed in the area and can continue fishing.

2. Configuration of aquaculture system of the present invention FIG. 1 is a schematic diagram of the configuration of aquaculture system 100 of the present invention.
The aquaculture system 100 of the present invention includes a water intake section 110 composed of a pipe and an electric pump (not shown) for taking in seawater or fresh water (hereinafter referred to as "seawater or the like").
Plankton such as copepods (radiopods) and other small crustaceans of several millimeters or less, such as copepoda represented by daphnids, inhabit seawater, etc., and reproduce by feeding on the larvae of the marine organisms to be reared. It is necessary to remove these.
In addition, it is desirable to remove bacteria such as saprophytic bacteria and microorganisms such as viruses in order to prevent the reared marine organisms from becoming ill and from oxidizing and contaminating the breeding water.

Therefore, filtering means 120 is provided to remove these microorganisms.
Various methods are conceivable for the filtering means, and for example, a nano-sized filter can be used. A nano-sized filter can be a layered filter based on fibers of 5 to 200 nm. (on the order of 100 nm) can also be captured.

Filtration means other than nano-sized filters, such as electrolysis, can also be used, but nano-sized filters are preferred because they do not require large-scale equipment such as electrolysis. In addition, some filtering means such as a filter laminated with gravel or ceramics for purifying tap water can be used, and the filtering means is not limited to the above means.
By passing the seawater or the like 10 through the filtering means 120, the seawater or the like can be used as breeding water 20 for marine organisms or the like.

A desired amount of the breeding water 20 can be stored by the water reservoir 130 .
The breeding water 20 stored in the water storage unit 130 is supplied to the breeding tank 150 by the water supply unit 140 configured by a pipe or the like.
The aquaculture block 180 manufactured by the present invention is appropriately installed in the water reservoir 130 and the breeding tank 150 .

Although not shown, the water reservoir 130 and the breeding tank 150 may be provided with an electric heating mechanism or a cooling mechanism for adjusting the water temperature as appropriate.
In addition, as shown in FIG. 2, it is desirable to appropriately install an aeration device 190 such as an air pump in order to ensure an appropriate oxygen concentration (dissolved oxygen amount) in the breeding water. When the aeration device (oxygen supply device) 190 is installed so as to supply oxygen to the lower part of the aquaculture block, it is also effective in adjusting the activity of bacteria settled on the aquaculture block.

The breeding water in the breeding tank 150 can be appropriately replaced, and the amount and timing of discharge from the drain pipe 160 are adjusted by controlling the drain section 170 . In this case, it is desirable to discharge from the lower part of the breeding tank, where food and feces of reared marine organisms and the like are likely to settle, but the present invention is not limited to this.
It should be noted that an automatic adjustment mechanism, such as shown in FIG. 2, may be provided to place the outlet of the water pipe 161 at the same position as the water level of the breeding water, instead of adjusting by the drainage unit 170 .
Moreover, FIG. 3 shows an example in which a plurality of breeding tanks 150 are connected in parallel to the water storage section 130 of the aquaculture system 100 of the present invention.

3. Flow of Generating Powdery Cohesive Material Next, a flow of generating a powdery cohesive material by activating raw volcanic ash and ash obtained by burning silicic acid plant will be described with reference to FIG.

In particular, volcanic ash soil containing a large amount of glassy substances such as silicon dioxide is called Shirasu, and its composition consists of 70 to 80% glassy substances with silicon dioxide as the main component, aluminum oxide at about 10%, and sodium oxide. Including about a few percent. It is said that the amount of reserves in Japan is 200 million tons, and it can be used as an abundant resource.
Volcanic ash other than shirasu can also be used as a raw material.In that case, aluminum dioxide (alumina) is added to make it closer to the composition ratio of shirasu, but reserves are inexhaustible.

Shirasu has the property of aggregating impurities, and this property can be used to purify breeding water for marine organisms. Due to the zeta potential characteristics of silicon dioxide alone, the cohesive force may not be sufficient as it is.
As for this point, the same inconvenience occurs when diatomaceous earth existing in nature is baked and used without changing the component ratio, as in the prior art described above.

In particular, when it is hardened into blocks, it is difficult to fully exert its cohesive action. Therefore, by going through a predetermined process, silicon dioxide is activated to make it easier to dissolve in water and to increase cohesiveness. It is necessary to

Heat treatment and electrical treatment are known as predetermined processes for activating the surface properties of silicon dioxide. By heating to about 1750° C. to activate or amorphize (amorphize) silicon dioxide, and then reacting with alkali to impart the property of being soluble in water, impurities are removed. It is possible to increase the aggregation ability.

Among the silicon dioxide contained in general shirasu, the amorphous ratio is 10 to 20%, but according to the process of the present invention, although it cannot be achieved up to 100%, it can be reduced to about 50 to 90%. It has been found that it can be made non-crystalline (amorphized) in proportion. This activates the surface properties of the silicon dioxide, making it more soluble in water.

In addition, by treating silicon dioxide and aluminum oxide, which are the main components of the cohesive material, at a high temperature, it is possible to homogenize the mixing or bonding relationship between the molten silicon dioxide and aluminum oxide, which is a component that is difficult to dissolve in water. The aluminum oxide becomes colloidal together with the active silicon dioxide that has become easily soluble in water, making it easier to dissolve in water, and when the cohesive material is dissolved in water, the compound of silicon dioxide and aluminum oxide It is possible to improve the aggregation ability by utilizing the zeta potential characteristics.

Details will be described below with reference to FIG.
First, as a cohesive material, shirasu (volcanic ash) containing silicon dioxide, or volcanic ash other than shirasu or ash containing silicon dioxide obtained by incinerating silicic acid plants, is added at a predetermined ratio with aluminum oxide or the like to obtain silicon dioxide and A material in which the component ratio of aluminum oxide is close to a predetermined ratio, or a material in which the component ratio of silicon dioxide and aluminum oxide is close to a predetermined ratio in ash containing silicon dioxide obtained by incinerating a silicic acid plant is prepared.

Then, this material is heated to a high temperature of 1600° C. or higher to be melted (steps 500 to 520).
If the temperature is raised to 1600-1750° C. in about 10 minutes, the setting is 160-175° C./min (step 510).
Here, the heating temperature and the temperature gradient at that time are examples, and the present invention is not limited to these. Any amount may be used as long as it activates the surface properties of silicon dioxide, melts silicon dioxide to some extent, and forms a compound with aluminum oxide.
The melting point of silicon dioxide is around 1,700°C, but even if it is not completely melted into a liquid state, it should be fluid to some extent and fused with aluminum oxide to uniformly mix. Alternatively, the melting point of aluminum oxide may be increased to 1700 to 2100° C., which is a range up to approximately 2070° C., which is the melting point of aluminum oxide.

However, the higher the temperature, the more thermal energy is required and the higher the cost, and the higher the refractory temperature of the furnace material.
Therefore, the temperature of about 1600 to 1750° C. is well balanced from the viewpoint of producing a compound in which silicon dioxide and aluminum oxide are sufficiently uniformly mixed and from the viewpoint of other factors such as cost.
In short, a temperature of approximately 1600° C. or higher is sufficient, and a compound in which silicon dioxide and aluminum oxide are sufficiently uniformly mixed can be produced within that temperature range, so a cohesive material with improved cohesiveness can be obtained. .

FIG. 9 shows the tendency of change in heating temperature and cohesion performance (relative value ).
According to FIG. 9, the activation effect on silicon dioxide begins to appear at about 1000 ° C., the aggregation performance increases sharply from around 1500 ° C., and reaches 80% or more of the maximum value at 1600 ° C. or higher, and the raw material is compounded. Therefore, it can be seen that the aggregation performance is further enhanced.

After heating to 1600 to 1750° C., the high temperature state is maintained for, for example, about 10 minutes as a stabilization time for complete dissolution (step 530).
After that, it is rapidly cooled to stabilize the amorphous state (step 540).
At this stage, a stabilized rock-like block is produced in an activated state of silicon dioxide, which is the main component of shirasu (step 550).
A rock-like block made of this powdery cohesive material contains metal components such as amorphous silicon dioxide and aluminum oxide, and thus has a metallic luster.

Next, the rock-like block composed of the activated silicon dioxide and aluminum oxide compound is finely ground (step 560) to form a fine powdery cohesive mass composed of the activated silicon dioxide and aluminum oxide compound. Generate material (step 570).
The particle size of fine pulverization is not particularly limited, but it is preferable that it is fine to some extent in order to maintain a certain aggregation ability. is desirable.

The temperature gradient at the time of temperature rise, the temperature to be raised, and the temperature gradient at the time of cooling are examples, and even if there is a certain width, it is possible to improve the amorphization and aggregation ability, as shown in FIG. It is not limited to the example described in FIG.
In addition to the temperature conditions, changing the pressure conditions causes a difference in the aggregation ability, but at least by keeping the above temperature conditions within a certain range, it is possible to improve the amorphization and the aggregation ability. Since it is possible, the pressure conditions are not limited.

Through this process, most silicon dioxide contained in volcanic ash such as shirasu and ash containing silicon dioxide generated by incinerating silicic acid plants is in an amorphous state. In addition to changing the bonding state of silicon and oxygen, the physical or chemical properties of the surface are changed to make it more soluble in water. By making the bonding state of silicon dioxide and aluminum oxide contained in raw materials such as shirasu uniform, the zeta potential characteristics of silicon dioxide and aluminum oxide in the form of a compound can be used to reduce the ability to agglomerate impurities. can be improved.

Here, detailed research has not progressed on the mechanism of changing the bonding state of silicon and oxygen, but in general, the energy state, electron bonding state, and attraction It is presumed that this is due to the change in properties in the ionized state.

In addition, as for the component ratio of Shirasu, 70 to 80% of its composition consists of a glassy substance mainly composed of silicon dioxide, and about 10% of aluminum oxide is included, so that it can be melted at a high temperature of 1600 ° C. or higher. When the compound is produced, the aluminum oxide is appropriately exposed on the surface of the silicon dioxide according to the content ratio. As a result, due to the zeta potential characteristics of the compound, it is positively ionized when dissolved in water, increasing the absolute value of the zeta potential and increasing the agglomeration of negatively charged impurities.

The zeta potential characteristic of silicon dioxide alone has a negative absolute value of about 10 mV near pH 8, but if aluminum acoions derived from aluminum sulfate or aluminum chloride exist at a certain rate, the zeta potential has an absolute value of 30 mV. It becomes a positive value of about 40 mV. In addition, the zeta potential characteristic of aluminum oxide alone has a positive value of about several tens of mV in absolute value around pH 5-8.

The zeta potential of a compound of silicon dioxide and aluminum oxide is similar to the case where a certain proportion of aluminum acoions derived from aluminum sulfate or aluminum chloride are present in the state of silicon dioxide alone, and the zeta potential is positive with a predetermined absolute value. Cohesion ability is obtained by taking a value.

Therefore, when using volcanic ash other than Shirasu or ash containing silicon dioxide obtained by incinerating silicic acid plants, the amount of aluminum oxide is appropriately adjusted to adjust the zeta potential characteristics of the compound after melting at high temperature. good.

The composition of shirasu is about 70% to 80% (typical example about 74%) consists of vitreous material mainly composed of silicon dioxide, aluminum oxide about 10% (typical example about 14%), and sodium oxide. and can be used as it is as a raw material for a cohesive material. However, the ratio of silicon dioxide and aluminum oxide contained in the raw material used as the cohesive material of the present invention is not limited to this value. ratios within a certain range are acceptable.

FIG. 10 illustrates this. FIG. 10 shows how the impurity agglomeration performance changes (relative values) according to the mixing ratio of silicon dioxide and aluminum oxide when the heating temperature is 1600° C. or higher. According to FIG. 10, when the weight ratio (%) of aluminum oxide to silicon dioxide in the raw material is about 5%, the cohesion performance is about twice as high as that of silicon dioxide alone, which is the raw material. It is shown that a coagulation performance of about 80% or more of the maximum value can be exhibited within a range of 20%.

4. A step of dissolving a powdery cohesive material in water to form a solution of silicon, etc. Next, a powdery cohesive material containing a compound of silicon dioxide and aluminum oxide is used to contain a compound of silicon dioxide and aluminum oxide. A process of dissolving powder in water to form a colloidal solution (hereinafter referred to as "compound colloidal solution") will be described with reference to FIG.
Since the colloidal solution of the compound produced in this step is used to increase the cohesiveness of the aquaculture block, it will be described prior to the aquaculture block production step (see FIG. 7).

As explained in FIG. 5, a rock-like block produced in a predetermined high-temperature environment is finely pulverized to obtain a fine powder-like material composed of a cohesive material containing a compound of silicon dioxide and aluminum oxide.
This fine powdery material is mixed with water at a weight ratio of about 0.5 to 10% with respect to 100 of water (step 600). At that time, the PH value of water is set to 11 or more to dissolve in water (step 610). Of course, an aqueous solution having a pH value of 11 or higher may be used (combination of steps 600 and 610).

The fine powder material is composed of an activated compound of silicon dioxide and aluminum oxide, and has the property of being easily soluble in alkaline water. It melts (step 620).
In this way, a solution (colloidal solution of compound) in which powder of a compound of silicon dioxide and aluminum oxide is dissolved at a high concentration can be obtained (step 630).

However, since the pH value is too high in this state, the pH value is adjusted by appropriately diluting with water so that the pH value is about 7 to 8 (step 640). The degree of dilution is preferably about 0.5 to 1% by weight with respect to 100 of water, but is not limited to this.
Once ionized or colloidal, the colloidal solution of the compound of silicon dioxide and aluminum oxide can lower the pH value while maintaining the ionized or colloidal state. A solution can be obtained (step 650).

5. Manufacturing Process of Block for Aquaculture Next, the process for manufacturing the block for culture according to the present invention will be described with reference to FIG.
A powdery cohesive material composed of a compound of silicon dioxide and aluminum oxide obtained in the process of FIG. 5 is prepared (step 700). Then, a predetermined forming aid (for example, a binder for concrete or mortar) and a foaming agent (for example, a carbonate such as calcium carbonate or magnesium carbonate) are added, mixed appropriately, and then pressed into a block shape. , at a high temperature of about 800 to 1300° C. while foaming (step 710).
The shape and size of the block are not particularly limited, and may be spherical, cubic, rectangular parallelepiped, or other shapes. A rectangular parallelepiped of size may be selected.

A block-shaped material solidified by appropriately cooling is obtained (step 720).
Due to the effect of the foaming agent, this block-shaped material (impurity-aggregating block) has a large number of fine cavities, and has the property of allowing breeding water and the like to permeate the block.
For this reason, when held in the hand, the block feels lighter than pumice stone per volume.
It should be noted that, even at this stage, it has sufficient aggregation performance, but as will be described later, the aggregation performance can be further enhanced.
After that, microorganisms such as bacteria are added to the block-shaped material (impurity flocculation block) (this state is called an impurity flocculation/decomposition block). Bacteria can adhere to the microscopic cavities and permanently colonize impurities contained in the breeding water as food (step 730).

Here, the bacteria include nitrifying bacteria that decompose ammonia and other substances from the manure of reared animals with nitric acid, aerobic bacteria that decompose heavy metals such as organic tin, lead, and cadmium, marine bacteria, and iron. Oxidizing bacteria are known, and one or more of them are selected.

After that, the block-shaped material is immersed in the colloidal solution of the compound prepared in FIG. increase.
In addition, the bacteria may be allowed to settle after the infiltration/drying in the colloidal solution of the compound is repeated to a certain extent. It is also possible to use a block that has been infiltrated/dried in a colloidal solution of the compound (impurity agglomeration block coated with the colloidal solution of the compound) prior to bacterial colonization.

The step of infiltrating/drying the colloidal solution of the compound is not limited to the following, but for example, the step of infiltrating the colloidal solution of the compound for a certain period of time (for example, about 30 minutes) (step 740), once in the air for a certain period of time (for example, 1 2 days), drying and fixing (step 750), and this cycle may be repeated for a certain period of time (several days to several tens of days).
Then, after a certain number of cycles, the aquaculture block (impurity flocculation/decomposition block) of the present invention is completed (step 760).

6. Effect of maintaining the environment of breeding water in an aquaculture system using the aquaculture block of the present invention FIG. , FIG. 2, FIG. 8, etc., will be described below.
In the following description, the aquaculture block of the present invention is mainly a block for flocculating and decomposing impurities, but it is also possible to replace the blocks for flocculating impurities as appropriate every few months.

First, as shown in FIGS. 1 and 2, a plurality of aquaculture blocks 180 of the present invention are placed side by side in the water reservoir 130 or the breeding tank 150 . When an appropriate water flow is maintained, when the breeding water passes through the aquaculture block, it is infiltrated into the fine powder of the compound of active silicon dioxide and aluminum oxide, which is the material of the block, or the colloidal solution of the compound. / By touching the active silicon dioxide and aluminum oxide compound coated in the drying process, impurities such as surplus food that breeds bacteria and excreta of marine organisms raised are aggregated.

In parallel, bacteria settled in the microscopic cavities of the aquaculture blocks break down condensed impurities.
By repeating this cycle, over a long period of time, it is possible to prevent the breeding water from being contaminated with ammonia contained in feces and urine of the breeding organisms, and from breeding bacteria.

In addition, in the aquaculture system using the aquaculture blocks of the present invention, even when a large number of marine organisms such as sea cucumbers are bred, operation without replacement for several years is possible.
For example, when breeding hundreds of thousands to 10 million sea cucumbers of about 10 to 50 mm in a tank that stores 15 tons of breeding water, select a size such as 20 cm x 10 cm x 5 cm and 100 to 600 It is expected that the effect of removing impurities from breeding water will be maintained at 90% or more compared to new blocks for at least five years in an environment where about one block for aquaculture is used (according to an accelerated test). And if the amount of reared creatures is adjusted, it is expected that it will be possible to operate semi-permanently without replacement.

FIG. 8 illustrates these effects of the present invention.
According to FIG. 8, when the breeding water passes through the aquaculture block composed of water-permeable air bubbles, the impurities contained in the breeding water are aggregated, and the bacteria fixing the aggregated impurities are generated. Degradation is shown to remove impurities from the breeding water.

That is, according to the process for producing aquaculture blocks of the present invention, a raw material consisting of a mixture of silicon dioxide and aluminum oxide is activated or agglomerated through a predetermined process to produce a compound (see FIG. 5), A step of forming a block so as to contain air bubbles (the first half of FIG. 7), separately forming a colloidal solution of a compound composed of activated silicon dioxide and aluminum oxide (FIG. 6), and soaking or drying the block. Thus, the cohesive material can be adhered at high density even to the bubble portion (second half of FIG. 7).

In addition, by fixing bacteria in the air bubble part of the block (second half of Fig. 7), the cohesive material in the air bubble part can decompose the separated and aggregated impurities from the breeding water, and the cohesive force of the cohesive material in the air bubble part. can be maintained.

In this regard, in one example of the prior art, there is a technique in which a material containing a porous material structure of diatomaceous earth or crushed wood is included in a nonwoven fabric. Therefore, there is an inconvenience that cohesive force cannot be obtained by volume.
On the other hand, in the present invention, the cohesive force can be increased by volume by forming the block shape. In the prior art, the balance between the ability to aggregate impurities contained in sewage and the decomposition by bacteria was poor, making it difficult to adjust the water flow. It has the effect of facilitating the adjustment of the water flow as it passes through gently.

In addition, in one example of the prior art, although diatomaceous earth is fired at 800 ° C. or higher, as in the present invention, the critical significance of producing a compound of aluminum oxide and silicon dioxide at a higher temperature of 1600 ° C. or higher , neither described nor suggested the critical significance of the content of aluminum oxide and silicon dioxide.
On the other hand, in the present invention, in materials containing silicon dioxide (volcanic ash and ash obtained by incinerating silicic acid plants), a compound of silicon dioxide and aluminum oxide is produced by raising the temperature to about 1600 to 1750°C, which is close to the melting point of silicon dioxide. The critical significance of numerical values was found for homogenization of the binding state of the two in the process and improvement of water solubility and aggregation ability due to activation characteristics (see FIG. 9).

In addition, in the prior art, diatomaceous earth (mainly composed of silicon dioxide) was simply calcined, but in the present invention, a colloidal solution of a compound containing high concentrations of active silicon dioxide and aluminum oxide is produced, As a step after forming the block, a colloidal solution of the compound is infiltrated into the fine cavity portions and then dried, so that the aggregation ability of the block as a whole can be further enhanced.

In addition, regarding the fixation or adhesion of bacteria, from a microscopic point of view, there is similarity between the present invention and an example of the prior art in terms of fine pores in a porous material.
However, in the present invention, after making a block, there is a minute hollow part in the structure of the block, which has a volume, and the hollow part is a hollow part after securing a certain length as a passage. differ. As a result, in the present invention, the ability to coagulate is maximized by the action of gently adjusting the water flow flowing through the relatively long path of the block, and bacteria are stabilized in the gentle water flow. , the effect of being able to decompose aggregated impurities was neither described nor suggested in the prior art.

As a comparison experiment, instead of the aquaculture block of the present invention, bacteria were fixed on a porous sponge-like substance to remove impurities. Since the process of decomposing impurities by bacteria cannot be performed, there is almost no effect of removing impurities.

As described above, according to the aquaculture system using the aquaculture blocks of the present invention, a plurality of the aquaculture blocks 180 of the present invention are placed in the water storage section 130 and the breeding tank 150 as shown in FIGS. It can be effective by placing them side by side and maintaining an appropriate water flow. In other words, when the breeding water passes through the aquaculture block, it has the effect of aggregating impurities such as surplus feed that is the source of the breeding of various bacteria and the feces and urine of reared marine organisms, and the action of bacteria that have settled on the aquaculture block. By decomposing the impurities, it is possible to prevent, at a high level, the breeding water from being contaminated with ammonia contained in feces and urine of the breeding organisms, and from the breeding of bacteria and the like.

Moreover, according to the present invention, almost no breeding water needs to be replaced, so the risk of contamination by plankton, microorganisms, and viruses can be reduced compared to the case where the entire amount is replaced as in the prior art. In addition, costs can be reduced by reducing the burden on the filtering means 120, prolonging the replacement cycle of the filter, etc., and saving the electricity bill for heating and cooling when replacing the breeding water. In addition, there is an effect that changes in the environment of reared marine organisms can be minimized.

In addition, it is possible to greatly increase the yield of reared organisms at such a low cost. For example, in the case of sea cucumber farming, about 500,000 eggs hatch from about 8 million eggs, and about 10 juvenile sea cucumbers with a size of 35 to 50 mm were generated in the natural world. Even with the conventional aquaculture technology, about 10,000 to 30,000 juvenile sea cucumbers with a size of 35 to 50 mm were produced from about 8 million eggs, whereas the aquaculture method of the present invention, It has the effect of raising the number of fish to about 150,000, which is 5 to 15 times.

FIG. 11 shows this effect. In FIG. 11, when a block for aggregating and decomposing impurities is used as the aquaculture block, and a rectangular parallelepiped with a size such as 20 cm × 10 cm × 5 cm (equivalent to a tissue box) is selected for each block, the water quality of the aquaculture system can be maintained. It shows the difference in effectiveness or relative effectiveness of marine organism yield. According to FIG. 11, compared to the level of conventional aquaculture technology, using about 100 blocks for impurity flocculation and decomposition begins to show superiority over conventional aquaculture technology, and if about 500 blocks are used, conventional aquaculture technology It shows that the yield was 5 to 15 times higher than the standard.

The aquaculture system of the present invention can be applied to the aquaculture of sea cucumbers, sea urchins, and the like, as well as the aquaculture of shellfish and fish.

10 seawater or fresh water (seawater, etc.)
20 Seawater, etc. after filtration 30 Drainage 100 Aquaculture system of the present invention 110 Water intake section 120 Filtration means 130 Water storage section 140 Water supply section 150 Breeding tank 160 Drainage pipe 161 Drainage pipe (modification)
170 drainage unit 180 aquaculture block 190 aeration device (oxygen supply device)

Claims (5)

melting a raw material containing at least silicon dioxide and aluminum oxide at a temperature of 1600° C. or higher to produce a compound of silicon dioxide and aluminum oxide;
pulverizing the rock-like block obtained by cooling the compound to produce a cohesive material in powder form;
A step of molding the powdery cohesive material into a predetermined shape and performing foaming processing so as to include a plurality of fine cavities;
A method for manufacturing an impurity-aggregating block, comprising:
In the method for manufacturing an impurity-aggregating block according to claim 1 ,
The content ratio of silicon dioxide and aluminum oxide is the weight ratio of silicon dioxide and aluminum oxide in the whole raw material, and the ratio of silicon dioxide is 60 to 90% by weight and the ratio of aluminum oxide is 4.5 to 20% by weight. ,
The weight ratio of aluminum oxide to the total of silicon dioxide and aluminum oxide is 5 to 33%,
A method for manufacturing a block for aggregating impurities, characterized by:
The method for producing a block for impurity aggregation according to claim 1 , further comprising:
A colloidal solution of a compound obtained by dissolving a powdery aggregating material containing a compound of silicon dioxide and aluminum oxide in alkaline water having a pH value of 11 or more is added to a colloidal solution adjusted to a pH of 7 to 8 for aggregating impurities. Repeating the cycle of infiltrating the block and then drying it at least one or more times;
A method for manufacturing an impurity-aggregating block, comprising:
The method for producing a block for aggregating impurities according to claim 2 , further comprising:
A colloidal solution of the compound obtained by dissolving the powdery cohesive material containing the compound of silicon dioxide and aluminum oxide in alkaline water having a pH value of 11 or more is added to the colloidal solution adjusted to a pH of 7 to 8, and the impurities are added to the colloidal solution. A step of repeating the cycle of infiltrating the aggregation block and then drying it at least once or more;
A method for manufacturing an impurity-aggregating block, comprising:
The method for producing an impurity-aggregating block according to any one of claims 1 to 4 , further comprising:
A step of fixing bacteria in a plurality of fine cavities of the impurity aggregation block,
A method for producing a block for aggregating and decomposing impurities, characterized by establishing a cycle of aggregating and decomposing impurities by decomposing impurities agglomerated in fine cavities.

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