JP7424933B2 - Algae growing material - Google Patents

Description

The present invention relates to an algae growing material that supplies nutrients to algae living in coastal waters.

In recent years, a phenomenon called ``isoyake'' has occurred, in which algae such as kelp and wakame that live in coastal waters around Japan have decreased, leaving them barren, and this is having a serious impact on the ecosystem. The causes of rock formations are thought to be changes in ocean currents, damage caused by algae-eating animals (such as rabbitfish and sea urchins), and the inflow of large amounts of river water and sand. In some areas, photosynthesis becomes inactive and it is speculated that rock formations may occur.

To address the above-mentioned rocky shore problem, fertilization is sometimes carried out by artificially supplying fertilizer to coastal waters in order to promote the growth of algae. For example, in Patent Document 1, the outer shape is a rectangular parallelepiped, a through hole is formed that penetrates from one side to the opposite side, and the opening area on one side of the through hole is larger than the opening area on the other side. Broadly speaking, a fishing reef block (weed bed block) is disclosed in which the aggregate as a raw material is granulated slag containing soluble silicic acid and soluble lime, which are effective for growing plants.

Patent No. 5872199

When installing seaweed bed blocks in coastal waters, it is necessary to ensure a sufficient water depth from the sea surface to the seaweed bed blocks so as not to impede ship movement (navigation) during low tide. Furthermore, since the water depth in the target area is not deep, large ships cannot be used, and the seaweed bed blocks must be transported by small ships and dropped into the sea manually. Therefore, there are restrictions on the size and weight of the seaweed bed block, and the height is often 500 mm or less and the weight is about 10 kg. For example, the size of the seaweed bed block described in Patent Document 1 is approximately 150 mm to 300 mm in width and height, and 200 mm to 1000 mm in length, and the period during which nutrients contained in the seaweed bed block dissolve into seawater (elution period). is about 3 to 4 months.
However, since the algae bed blocks are installed before the algae spore scattering season (for example, April), the algae growth season is in autumn (for example, October), resulting in a shortage of nutrients necessary for algae growth.

The present invention has been made in view of the above circumstances, and provides an algae cultivation material that has approximately the same weight as a conventional seaweed bed block, but can extend the leaching period of nutrients compared to the conventional seaweed bed block. The purpose is to

In order to achieve the above object, the present invention provides an algae growing material that supplies nutrients to algae living in coastal waters,
It is characterized in that the contents, which are a mixture of nutrients and a water-soluble binder, are covered with a coating material which is a mixture of molten general waste slag and a solidifying agent, and are filled into a water-permeable bag.

In the present invention, the water-permeable bag is filled with contents covered with a covering material (solidified nutrients), so as described later, the weight is approximately the same as that of a conventional seaweed bed block. However, the amount of nutrients can be several times that of conventional seaweed bed blocks. At this time, the binder that solidifies the nutrients is water-soluble, and the coating material that covers the contents is porous using molten slag from general waste, so the rate at which nutrients dissolve into seawater (elution rate) is It is almost the same as the conventional seaweed bed block.

Further, in the algae growing material according to the present invention, it is preferable that the nutritional material is fermented animal manure, the water-soluble binder is carboxymethyl cellulose, and the solidifying material is a neutral solidifying material or a cement-based solidifying material.

By using fermented animal manure as the nutrient material, the settlement and growth of algae can be improved.
Other water-soluble binders include agar and gelatin, but carboxymethylcellulose is superior in terms of quality stability and unit price.
Examples of the solidifying agent include industrial agar, resin materials, neutral solidifying agents, cement-based solidifying agents, etc., but it is preferable to use neutral solidifying agents or cement-based solidifying agents in terms of material quality and cost.

Further, in the algae growing material according to the present invention, it is preferable that the volume of the nutrient is four times or more the volume of the water-soluble binder.
If the volume of the nutritional material is less than four times the volume of the water-soluble binder, the contents (solidified product of the nutritional material) will become too hard and the elution rate of the nutrients will decrease significantly.

Moreover, in the algae growing material according to the present invention, instead of the mixture of the nutrient and the water-soluble binder, the content may be a pellet of the nutrient. This eliminates the need for a water-soluble binder.

Further, in the algae growing material according to the present invention, it is preferable that the volume ratio of the general waste molten slag to the solidification material is 5:1 to 10:1.
If the volume of the general waste molten slag is less than 5 times the volume of the solidifying material, the porous property will be insufficient, while if it exceeds 10 times, the amount of the solidifying material will be too small to solidify the coating material.

Further, in the algae growing material according to the present invention, it is preferable that the volume ratio of the content to the coating material is 6:4 to 8:2.
If the volume of the contents is less than 1.5 times the volume of the dressing, the amount of the contents will be insufficient, while if it exceeds 4 times, the contents cannot be covered with the dressing.

Moreover, in the algae growing material according to the present invention, the bag body may be a sandbag made of linen cloth.
Synthetic fibers such as polyester are often used for sandbags, but sandbags made of burlap are preferable because they reduce environmental impact and are natural materials that can be used as food for fish and shellfish.

In the algae cultivation material according to the present invention, the solidified nutrient material covered with the porous covering material is filled into a water-permeable bag, and the binder for solidifying the nutrient material is water-soluble. Although it has approximately the same weight as a seaweed bed block, the nutrient elution period can be extended compared to conventional seaweed bed blocks.

1 is a sectional view of an algae growing material according to an embodiment of the present invention. It is a sectional view of the algae cultivation material concerning a modification.

Next, embodiments embodying the present invention will be described with reference to the attached drawings to provide an understanding of the present invention.

Algae that grow in coastal waters include Sargassum, Sargassum, and Kurome. The water depth of the algae growth area is 10 m or less and is an area where sunlight can reach.
The algae growing material according to the present invention is intended to supply nutrients to algae living in coastal waters. FIG. 1 shows a cross-sectional view of an algae growing material 10 according to an embodiment of the present invention.

The algae growing material 10 is made by covering a content 12 containing a mixture of nutrients and a water-soluble binder with a coating material 14 containing a mixture of molten slag from general waste and a solidifying material, and filling the material into a water-permeable bag 15. .

The nutrient material is fermented animal manure such as fermented cow manure, fermented pig manure, and fermented chicken manure. Among these, fermented cow dung contains a lot of fiber and is preferred as a nutritional material.
If the seawater temperature in the area where the algae growth material 10 is installed is high, Thermozyme (registered trademark) may be mixed with the fermented animal manure to promote absorption of nutrients at high temperatures. The plant activator ``Thermozyme'' contains sanguinarine, an ingredient extracted from the wild grass bamboo rush, and has the effect of promoting the production of proteins (HSP) that are resistant to high temperatures.

Carboxymethylcellulose is used as the water-soluble binder, and the concentration of the aqueous solution of carboxymethylcellulose is 8% by mass to 12% by mass.
Carboxymethylcellulose is an anionic water-soluble polymer obtained from cellulose. It has excellent thickening, water absorption and water retention properties. Because it is derived from natural cellulose, it is slowly biodegradable and is extremely environmentally friendly.

General waste molten slag is a sand-like product produced by melting general waste, sewage sludge, their incinerated ash, etc. at a high temperature of approximately 1300°C or higher in general waste melting processing equipment, and then cooling and solidifying with water. It is a thing. The ratio of silicic acid and lime is about the same, and the ratio of soluble silicic acid and soluble lime, which are effective for plant growth, is high, making it suitable for the growth of algae.

In particular, when a coke bed type gasification and melting furnace is used in general waste melting treatment equipment, the melting process is carried out at a high temperature of 1700 to 1800°C, so the generated molten waste slag has the same safety as natural aggregate. The main components, silicic acid (SiO ₂ ), lime (CaO), and aluminum oxide (Al ₂ O ₃ ), have stable component ratios throughout the year. In addition, the amount of hazardous components such as heavy metals in the general waste molten slag and the elution amount stably satisfy the standard values (Marine Pollution Countermeasures Law/Underwater Sediment Judgment Standards).

As for the particle size of the general waste molten slag, it is desirable that 100% by mass be 5 mm or less and 95% by mass or more be 2.5 mm or less.
The particle size (5 mm, 2.5 mm, etc.) and ratio of general waste molten slag are the nominal dimensions (5 mm, 2.5 mm) specified in JIS Z8801-1 "Test sieve - Part 1: Metal mesh sieve" is the mass percentage of molten slag that passes through a metal mesh sieve.

Note that steel slag (blast furnace slag, steelmaking slag) is available as an alternative recycled aggregate for general waste molten slag, but steel slag has a high pH value that accelerates the reaction with the solidifying agent, making the surface of the coating material 14 porous. The blending ratio to be maintained is not stable.

The solidifying material shall be a neutral solidifying material or a cement-based solidifying material.
A typical neutral solidifying material is a gypsum-based solidifying material whose main component is gypsum hemihydrate. Gypsum-based solidifying materials are environmentally friendly solidifying materials because the main raw material, gypsum, is neutral.
Cement-based solidifying materials include Portland cement, blast furnace cement, and fine particles of 5 mm or less of crushed concrete blocks.

The volume of the nutrient material should be at least four times the volume of the water-soluble binder.
The volume ratio of general waste molten slag and solidification material is 5:1 to 10:1.
The volume ratio of the contents 12 and the covering material 14 is 6:4 to 8:2.

The bag body 15 is a sandbag made of linen cloth.

If fermented cow dung is used as the nutritional material, the volume ratio of the content 12 and the coating material 14 is 7:3, and the volume ratio of fermented cow dung and carboxymethyl cellulose is 4:1, the proportion of fermented cow dung in the algae cultivation material 10 is: 0.7×0.8=0.56, that is, 56% by volume, which is about 5.6 times the proportion of fermented cow dung in a conventional seaweed bed block (about 10% by volume). Since the elution rate of fermented cow dung in the algae growing material 10 and the conventional seaweed bed block is almost the same, the elution period of fermented cow dung in the algae growing material 10 is (3 months to 4 months) x 5.6 = 16.8 months to 22 .4 months, ensuring a sufficient elution period for algae growth.

FIG. 2 shows a cross-sectional view of an algae growing material 11 according to a modified example.
The algae growing material 11 differs from the algae growing material 10 in that the content 13 is a pelleted nutrient material 16. The diameter of the pellet is about 1 cm. By forming the nutritional material 16 in pellet form, a water-soluble binder is not necessary.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the above-described embodiments, and can be considered within the scope of the claims. It also includes other embodiments and modifications.

10, 11: Algae growth material, 12, 13: Contents, 14: Covering material, 15: Bag body, 16: Nutrient material

Claims (8)

An algae cultivation material that supplies nutrients to algae living in coastal waters,
An algae growing material characterized in that the contents of a mixture of nutrients and a water-soluble binder are covered with a coating material of a mixture of general waste molten slag and a solidification material, and filled in a water-permeable bag. 2. The algae growing material according to claim 1, wherein the nutritional material is fermented animal manure, the water-soluble binder is carboxymethyl cellulose, and the solidifying material is a neutral solidifying material or a cement-based solidifying material. 3. The algae growing material according to claim 2, wherein the volume of the nutrient material is four times or more the volume of the water-soluble binder. An algae cultivation material that supplies nutrients to algae living in coastal waters,
1. An algae growing material characterized in that a pelleted nutrient material is covered with a covering material made of a mixture of molten slag from general waste and a solidifying material, and is filled in a water-permeable bag. 5. The algae growing material according to claim 4, wherein the nutritional material is fermented animal manure, and the solidifying material is a neutral solidifying material or a cement-based solidifying material. The algae growing material according to any one of claims 1 to 5 , characterized in that the volume ratio of the general waste molten slag to the solidification material is 5:1 to 10:1. The algae growing material according to any one of claims 1 to 6 , characterized in that the volume ratio of the content to the coating material is 6:4 to 8:2. The algae growing material according to any one of claims 1 to 7 , wherein the bag body is a sandbag made of linen cloth.

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