JP6571335B2 - Supply method of aquaculture materials - Google Patents

Description

  The present invention relates to an aquaculture material and a method for producing the same.

When aquatic organisms are cultivated in aquaculture ponds or closed water areas (inland bays, inland seas, lakes, etc.), water-soluble phosphoric acid derived from food residues or excrement of aquatic organisms, An aquaculture pond or the like may become eutrophic due to release and accumulation of ammonia nitrogen, nitrate nitrogen, and the like in water.
When aquaculture ponds, etc. become eutrophic, blue sea bream and the like occur, the amount of dissolved oxygen in the water decreases, oxygen becomes scarce for aquatic organisms, or anaerobic microorganisms grow and become aquatic organisms. There is a problem that harmful hydrogen sulfide is generated and the survival rate and weight gain rate of aquatic organisms to be cultured are reduced.

Examples of a method for solving the above problem include a method of periodically replacing water in an aquaculture pond and the like to maintain water quality, a method of spraying zeolite, and the like.
The method of periodically replacing the water in the aquaculture pond needs to be frequently performed, and there is a problem that the operating cost of the pump is high. In addition, the method of spraying zeolite can suppress the occurrence of blue water etc. by adsorbing nitric acid to the sprayed zeolite, but the adsorption of nitric acid is easily inhibited by sulfate ions and chloride ions present in water. There is a problem in that the amount and the frequency of application of zeolite increase.

On the other hand, there is known a method for suppressing the occurrence of blue sea bream by growing diatoms in water. Unlike blue sea bream, diatoms have low toxicity, and various aquatic organisms can use diatoms as food. By growing diatoms, the survival rate and weight gain rate of aquatic organisms can be improved (increased). it can.
Examples of the method for growing diatoms in water include a method of spraying water glass or silica gel, a method of spraying a material containing calcium silicate, and the like. According to these methods, silicon (Si) necessary for the growth of diatom is released as SiO ₂ into the water, thereby promoting the growth of diatom and suppressing the occurrence of blue sea bream.
As an example of the technique for growing diatoms in water as described above, Patent Document 1 discloses a feed for cultured fish mainly composed of porous calcium silicate having a solubilization rate of 50% or more. In Patent Document 1, silicate ions eluted from the porous calcium silicate contained in the feed serve as diatom food and promote the growth of diatoms, and hence the occurrence of flagellate algae causing red tides. It is also described that the effect of being suppressed and maintaining good water quality is expected.

JP-A-6-54652

The method of spreading water glass or silica gel to grow diatoms in water has a large amount of SiO ₂ released into water, but SiO ₂ is re-precipitated by chloride ions present in water. There is a problem that the amount of SiO _{2 that} can be used is smaller than the amount of SiO ₂ contained in water glass or silica gel.
On the other hand, the method of spraying a material containing calcium silicate described in Patent Document 1 has a slower release of SiO ₂ from the material containing calcium silicate into water than water glass or silica gel. Therefore, reprecipitation of SiO ₂ is less likely to occur. Moreover, since calcium ions and magnesium ions are released into water at the time of dissolution, the effect of further promoting the growth of diatoms and the effect of improving the survival rate of crustaceans can be expected.
However, when a material containing calcium silicate is actually sprayed on an aquaculture pond or the like, even if the material contains a large amount of SiO ₂ , the effect of promoting the growth of diatom may be small.
For example, when a material containing calcium silicate is left outdoors, a water-soluble silicate component (hereinafter referred to as “water-soluble SiO ₂ ”) contained in the material comes into contact with water due to rain or the like. Elution may reduce the effect of diatom growth per unit mass of the material. Moreover, since the ratio of water-soluble SiO _{2 in} the total silicic acid component differs depending on the method for producing the material containing calcium silicate, even if the amount of the total silicic acid component is large, the ratio of the water-soluble SiO ₂ is small. In some cases, the diatom growth effect may be small.

By the way, since diatom growth and photosynthesis require calcium (Ca) and magnesium (Mg), as a method for growing diatoms in water, calcium carbonate, calcium hydroxide, magnesium carbonate, magnesium hydroxide, or A method of spraying a substance containing at least one of calcium and magnesium such as dolomite is also conceivable. By supplying calcium or magnesium into water by this method, the growth of diatom can be further promoted. Moreover, since this diatom contains abundant calcium and magnesium, formation of the exoskeleton of the crustacean which preyed on this diatom is promoted, and the survival rate of the crustacean can be improved.
However, although a method of spraying a substance containing at least one of calcium and magnesium such as calcium carbonate, calcium hydroxide, magnesium carbonate, magnesium hydroxide, or dolomite, although the amount of calcium or magnesium released into water is large, If the amount of silicon in the water is not sufficient, there is a problem that the effect of promoting diatom growth is limited.
An object of the present invention is to provide a culture material capable of further promoting the growth of diatoms in water and improving the survival rate and weight gain rate of aquatic organisms.

As a result of intensive studies to solve the above problems, the present inventor has aquaculture in which the elution amount of water-soluble SiO ₂ is 3 mg or more when a culture material is added in an amount of 1 g per 1 liter of distilled water. According to the materials for use, the present inventors have found that the above object can be achieved and completed the present invention.
That is, the present invention provides the following [1] to [7].
[1] A culture material containing calcium silicate for supplying into aquaculture water for aquatic organisms, when the culture material is added in an amount of 1 g per 1 liter of distilled water An aquaculture material, wherein the elution amount of water-soluble SiO ₂ is 3 mg or more.
[2] Mass ratio of the total elution amount of water-soluble CaO and water-soluble MgO to the elution amount of water-soluble SiO ₂ in the case of adding 1 g of the above culture material to 1 liter of distilled water (water-soluble The aquaculture material according to [1], wherein the total elution amount of CaO and water-soluble MgO / elution amount of water-soluble SiO ₂ is 10 or less.
[3] The above-mentioned [1] or [2], wherein an elution amount of water-soluble Al ₂ O ₃ is 0.06 mg or less when the culture material is added in an amount of 1 g with respect to 1 liter of distilled water. For aquaculture.
[4] In any one of the above [1] to [3], when the culture material is added in an amount of 1 g with respect to 1 liter of distilled water, the elution amount of water-soluble TiO ₂ is 0.02 mg or less. The aquaculture material described.
[5] The aquaculture material according to any one of [1] to [4], including one or more selected from the group consisting of tobermorite, zonotrite, CSH gel, and wollastonite.
[6] A method for producing the aquaculture material according to any one of [1] to [5] above, wherein (a) the calcium silicate-containing raw material is used as it is (b) 1,100 A method for producing an aquaculture material, wherein the aquaculture material is obtained by either firing at ˜1,400 ° C. or (c) placing in a carbon dioxide atmosphere.
[7] The method for producing an aquaculture material according to [6], wherein the calcium silicate-containing raw material is pulverized, classified, or granulated.

According to the aquaculture material of the present invention, the growth of diatoms in water can be further promoted.
Moreover, as a result of the more accelerated growth of diatoms in the water, the occurrence of sea cucumber and the like can be suppressed in the aquaculture pond or closed water area. As a result, it is possible to suppress the deterioration of the water quality of the aquaculture pond and improve the survival rate of the aquatic organisms that are the aquaculture target. Furthermore, the growth of shellfish, shellfish, fish (especially, fry), zooplankton, etc. that feed on diatoms is improved, and the weight gain rate and survival rate of aquatic organisms that are farmed can be improved.

The aquaculture material of the present invention is an aquaculture material containing calcium silicate to be supplied into aquaculture water for aquatic organisms. The aquaculture material is 1 g of distilled water per liter. When added, the elution amount of water-soluble SiO ₂ is 3 mg or more.
The aquaculture water supplied with the aquaculture material of the present invention is not particularly limited, and may be any of fresh water, brackish water, and seawater.
Examples of aquatic organisms include fish, shellfish, and crustaceans that can be cultivated in the fresh water and the like. Among them, aquatic organisms that feed on diatoms (for example, crustaceans such as shrimps) are rich in silicon, calcium, and magnesium, and the shellfish whose growth is promoted by supplying the aquaculture material of the present invention, Since it promotes the formation of exoskeletons and the like, it is suitable as an aquatic organism that is a target of the aquaculture material of the present invention.

When 1 g of the aquaculture material of the present invention is added to 1 liter of distilled water, the elution amount of water-soluble SiO ₂ is 3 mg or more, more preferably 4 mg or more, and particularly preferably 5 mg or more. If the elution amount is 3 mg or more, the growth of diatoms in water can be sufficiently promoted. The upper limit of the elution amount is not particularly limited, but is preferably 50 mg or less, more preferably 30 mg or less, from the viewpoint of preventing reprecipitation of SiO ₂ due to chloride ions in water.
The amount of elution of water-soluble SiO _{2 is} the elution of SiO ₂ after being left for a predetermined time (for example, 7 days) after adding and mixing the culture material of the present invention in an amount of 1 g to 1 liter of distilled water. Amount. The predetermined time here may be a time required for the elution amount of the water-soluble SiO ₂ from the aquaculture material of the present invention to reach a peak, preferably 2 hours or more, more preferably 4 hours or more, Preferably it is 6 hours or more, and particularly preferably 12 hours or more.
Incidentally, the amount of elution of the water-soluble SiO _2, compared with the content and the elution amount of soluble SiO ₂ extracted with hydrochloric acid from aquaculture materials of all silicate component (total SiO ₂₎ of aquaculture materials, It has a high correlation with the amount of diatom growth in aquaculture ponds.

Mass ratio of total amount of elution of water-soluble CaO and water-soluble MgO to the amount of elution of water-soluble SiO ₂ in the case of adding 1 g of the culture material of the present invention to 1 liter of distilled water (water-soluble The total elution amount of CaO and water-soluble MgO / elution amount of water-soluble SiO ₂ is preferably 10 or less, more preferably 8 or less, and particularly preferably 6 or less. When the mass ratio is 10 or less, the growth of diatoms in water can be further promoted, and the formation of exoskeletons of crustaceans that prey on the diatoms can be promoted.

When 1 g of distilled water is added to 1 liter of distilled water, the elution amount of water-soluble Al ₂ O ₃ is preferably 0.06 mg or less, more preferably 0.05 mg or less, especially Preferably it is 0.04 mg or less. Since Al (aluminum) is toxic to aquatic organisms, by reducing the elution amount of water-soluble Al ₂ O ₃ to 0.06 mg or less, the growth of diatoms is further promoted and the survival rate of aquatic organisms is further improved. Can do.

The elution amount of water-soluble TiO ₂ when the culture material of the present invention is added in an amount of 1 g per 1 liter of distilled water is preferably 0.02 mg or less, more preferably 0.01 mg or less. Since Ti (titanium) is toxic to aquatic organisms, by making the elution amount of water-soluble TiO ₂ 0.02 mg or less, it is possible to further promote the growth of diatoms and further improve the survival rate of aquatic organisms. .

The aquaculture material of the present invention is any one of (a) used as it is, (b) fired at 1,100 to 1,400 ° C., and (c) placed in a carbon dioxide atmosphere with respect to the calcium silicate-containing raw material. Can be obtained by:
In obtaining the aquaculture material of the present invention, the calcium silicate-containing raw material can be pulverized, classified or granulated in advance.
When firing, the heating temperature is preferably 1,100 to 1,400 ° C, more preferably 1,200 to 1,300 ° C.
When placed in a carbon dioxide atmosphere, the concentration of carbon dioxide is preferably 2 to 100% by volume, more preferably 4 to 40% by volume, particularly from the viewpoint of shortening the processing time and the ease of forming the carbon dioxide atmosphere. Preferably it is 5-30 volume%.

The calcium silicate-containing raw material contains at least one selected from the group consisting of tobermorite, zonotrite, CSH gel, wollastonite and the like.
Tobermorite means Ca ₅ · (Si ₆ O ₁₈ H ₂ ) · 4H ₂ O (plate-like form), Ca ₅ · (Si ₆ O ₁₈ H ₂ ) (plate-like form), Ca ₅ · (Si ₆ It has a chemical composition such as O ₁₈ H ₂ ) · 8H ₂ O (fibrous form).
Zonotolite has a chemical composition such as Ca ₆ · (Si ₆ O ₁₇ ) · (OH) ₂ (fibrous form).
Wollastonite has a chemical composition such as CaO.SiO ₂ (fibrous or columnar form).
The CSH gel, those having a chemical composition of _{αCaO · βSiO 2 · γH 2 O} ( provided that, alpha / beta = 0.7 to 2.3, a γ / β = 1.2~2.7.) is there. Specific examples include calcium silicate hydrate having a chemical composition of 3CaO.2SiO ₂ .3H ₂ O.
Among them, tobermorite is preferable from the viewpoint of availability and economy. As tobermorite, natural minerals may be used, but from the viewpoint of easy availability, it is preferable to use lightweight cellular concrete (ALC) mainly composed of tobermorite. Further, from the viewpoint of promoting the use of waste materials, it is more preferable to use defective products generated in the lightweight cellular concrete manufacturing process or the ends of the lightweight cellular concrete generated at the construction site.

The lightweight cellular concrete is made of tobermorite and unreacted silica stone, and has a porosity of about 80% by volume. Here, the porosity means the ratio of the total volume of the voids in the entire volume of the granules.
The proportion of tobermorite in the lightweight cellular concrete is about 65 to 80% by volume, with the whole solid phase excluding voids inside the concrete being 100% by volume.
The lightweight cellular concrete can be obtained, for example, by autoclaving a raw material (for example, a hardened body made of a mixture thereof) containing quartzite powder, cement, quicklime powder, foaming agent (for example, aluminum powder), water and the like. .

  The calcium silicate-containing raw material is preferably porous. When the calcium silicate-containing raw material is porous, when the aquaculture material of the present invention is added to water, the air present in the porous portion of the calcium silicate-containing raw material is entrained in water, It is possible to prevent a decrease in the amount of dissolved oxygen.

The particle size of the aquaculture material of the present invention is preferably 5 mm or less, more preferably 4 mm or less, and particularly preferably 3 mm or less, from the viewpoint of increasing the elution amount of water-soluble SiO ₂ . The lower limit of the particle size is preferably 0.001 mm, more preferably 0.005 mm, and particularly preferably 0.01 mm from the viewpoint of reducing energy required for pulverization.
The particle size distribution of the aquaculture material of the present invention is preferably one containing a material having a particle size of 5 mm or less in a proportion of 70% by mass or more, more preferably from the viewpoint of increasing the elution amount of water-soluble SiO _2. A material having a particle size of 4 mm or less is contained in a proportion of 70% by mass or more, and a material having a particle size of 3 mm or less is particularly preferably contained in a proportion of 70% by mass or more.
In addition, in this specification, the value of a particle size is a value corresponding to the opening size of a sieve.

By supplying the aquaculture material of the present invention into the aquaculture water, the growth of diatoms in the water can be promoted.
Moreover, since the culture material of the present invention has a slow release rate of SiO ₂ into water, reprecipitation of SiO ₂ due to chloride ions hardly occurs.
Furthermore, since the aquaculture material of the present invention includes a calcium silicate-containing raw material, an alkaline substance is released into water, and acidification of water can be prevented.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
[Example 1]
(1) Manufacture of materials for aquaculture Manufacture of materials for aquaculture by crushing the end material A of lightweight aerated concrete (ALC) mainly composed of tobermorite using a mallet until the particle size becomes 3 mm or less. did.
The chemical composition of the obtained aquaculture material was measured using a scanning X-ray fluorescence analyzer (trade name: ZSX100e; manufactured by Rigaku Corporation). The ignition loss (ig.loss) was calculated from the weight loss when ignited until reaching a constant weight at 950 ° C. based on “JIS R 5202”. The results are shown in Table 1.
Moreover, after adding 1 g of obtained culture materials to 1 liter of distilled water and shaking, it was left still for 7 days. Each amount of water-soluble SiO ₂ , water-soluble MgO, water-soluble CaO, water-soluble Al ₂ O ₃ , and water-soluble TiO ₂ eluted in 1 liter of distilled water after standing was measured using an ICP emission spectrometer (trade name) : ULTIMA2; manufactured by HORIBA, Ltd.). The results are shown in Table 2.

(2) Cultivation of diatom After adding 34 g of artificial seawater raw material (trade name: Sea Life; manufactured by Marine Tech Co., Ltd.) to 1 liter of distilled water to obtain artificial seawater, (Product name: KW21; manufactured by Daiichi Seimitsu Co., Ltd.) 0.5 ml was added and mixed to obtain a culture solution containing no aquaculture material.
Subsequently, the culture material of the quantity shown in Table 3 was added to this culture solution to obtain a culture solution for diatom growth. Then, diatoms (diatoms belonging to the genus Keatoseros) in an amount such that the number of diatom cells in the culture solution is 0.8 × 10 ⁶ cells / liter are added to this culture solution, and air is supplied using an air pump. By doing so, diatoms were cultured.
The amount of the aquaculture material added to the culture solution is such that the amount of water-soluble SiO ₂ is 10 mg / liter after 7 days from the addition.
After the addition of diatoms, the number of diatom cells in the culture solution was measured at each time point on day 0 (at the time of addition), day 7 and day 28. The results are shown in Table 3.

[Example 2]
A fired product mainly composed of wollastonite obtained by firing the aquaculture material of Example 1 for 30 minutes at 1200 ° C. using an electric furnace, using a mallet, the particle size is 3 mm or less. The material for aquaculture was manufactured by crushing.
[Example 3]
An aquaculture material was produced in the same manner as in Example 1 except that a lightweight cellular concrete (ALC) end material B mainly composed of tobermorite was used as the calcium silicate-containing material.
[Example 4]
As a calcium silicate-containing raw material, a slurry obtained by mixing calcium oxide, silica, and water was subjected to a hydrothermal reaction at 180 ° C. and 10,000 hPa for 10 hours, filtered, and then dried. An aquaculture material was produced in the same manner as in Example 1 except that it was used.

[Comparative Example 1]
As the calcium silicate-containing raw material, a lightweight foam concrete (ALC) end material B mainly composed of tobermorite was exposed outdoors for one year. The material for aquaculture was manufactured by pulverizing the calcium silicate-containing raw material with a mallet until the particle size became 3 mm or less.
The chemical components of the aquaculture materials obtained in Examples 2 to 4 and Comparative Example 1, the amount of water-soluble SiO ₂ , and the number of diatom cells in the culture solution to which the aquaculture materials were added Measured in the same manner as above. The results are shown in Tables 1 to 3.

From Table 3, the number of diatoms when the aquaculture material of the present invention (the amount of water-soluble SiO ₂ is 3 mg / L or more) is added to water (Examples 1 to 4) is the amount of water-soluble SiO ₂ It can be seen that it is very large compared to the case where the aquaculture material having a pH of less than 3 mg / L is added to water (Comparative Example 1).

[Example 5]
(3) Shrimp farming test Twenty juvenile banana shrimps were placed in a tank containing 200 liters of seawater and fed twice a day while aeration was performed. Once a day, the shrimp was raised by adding it to the water tank in an amount (mass basis) of 20 ppm with respect to 200 liters of seawater. After the lapse of 60 days, the number of survivors and body weights of the shrimp in the aquarium were measured, and the survivorship rate and weight gain rate of the shrimp were calculated from these values.
[Comparative Example 2]
In the same manner as in Example 5 except that no aquaculture material was added, the lobster shrimp was bred, and the survival rate and weight gain rate of the lobster shrimp were calculated. The results are shown in Table 4.

From Table 4, when the culture material of the present invention (the amount of water-soluble SiO ₂ is 3 mg / L or more) is added to water (Example 5), compared to the case where it is not added (Comparative Example 2), It can be seen that the survival rate and the weight gain rate are improved.

Claims (7)

(A) About the aquaculture material containing calcium silicate for supplying into the aquaculture organism aquaculture water, after adding and mixing the above aquaculture material in an amount of 1 g with respect to 1 liter of distilled water, A step of measuring the elution amount of water-soluble SiO ₂ when left standing for 2 hours or more;
(B) the elution amount, check whether a 5 mg or more supply, if the elution amount is 5 mg or more, the aquaculture material, in the water for farming of aquatic organisms A method for supplying an aquaculture material, comprising the step of: In the step (A), together with the elution amount of the water-soluble SiO ₂ , the elution amount of the water-soluble CaO and the elution amount of the water-soluble MgO are measured,
In the step (B), the mass ratio of the total amount of elution of the water-soluble CaO and the amount of water-soluble MgO and the amount of elution of the water-soluble SiO ₂ (elution amount of water-soluble CaO and elution of water-soluble MgO) It is confirmed whether or not the total amount of water / elution amount of water-soluble SiO ₂ is 10 or less, and when the mass ratio is 10 or less, the culture material is used for aquaculture. The method for supplying an aquaculture material according to claim 1, wherein the material is supplied into water. In step (A), together with the elution amount of the water-soluble SiO ₂ , the elution amount of the water-soluble Al ₂ O ₃ is measured,
In the step (B), it is confirmed whether or not the elution amount of the water-soluble Al ₂ O ₃ is 0.06 mg or less, and when the elution amount is 0.06 mg or less, The method for supplying an aquaculture material according to claim 1 or 2, wherein the material is supplied into water for aquaculture of aquatic organisms. In step (A), the amount of water-soluble TiO ₂ is measured together with the amount of water-soluble SiO ₂ ,
In step (B), it is confirmed whether or not the elution amount of the water-soluble TiO ₂ is 0.02 mg or less. When the elution amount is 0.02 mg or less, the aquaculture material is added. The method for supplying aquaculture materials according to claim 1, wherein the aquaculture organism is supplied into water for aquaculture.   The aquaculture material according to any one of claims 1 to 4, wherein the aquaculture material is obtained by pulverization using a material containing at least one selected from the group consisting of tobermorite, zonotrite, CSH gel and wollastonite. Supply method.   The said culture material is obtained by baking and grinding | pulverizing at 1,100-1400 degreeC by making into a raw material what contains 1 or more types chosen from the group which consists of a tobermorite, a zonotlite, a CSH gel, and a wollastonite. 5. The method for supplying an aquaculture material according to any one of 4 above. The method for supplying an aquaculture material according to any one of claims 1 to 6 , wherein the aquaculture material includes a material having a particle size of 5 mm or less at a ratio of 70% by mass or more.