JPH03131393A - Method for purifying sea water - Google Patents

Abstract

PURPOSE:To eliminate operations for removal of marine plants and to obtain at the same time by-products of sea water purification by growing marine plants using nutritive substances in sea water to remove nutritive substances for purification of sea water and by culturing edible marine animals using said marine plants as baits. CONSTITUTION:Sea water contaminated with eutrophicated salts is fed into a filtering tank 2 via a feed pipe 1 to remove impurities and said sea water is caused to flow down over the side of the tank 2 from the upper side thereof so as to be aerated. The aerated sea water is passed through a partition net 3, a purification channel 4 and then through a partition net 5 on the downstream side and is discharged to the sea from a discharge pipe 8. Sea weeds 6, as marine plants, are grown in the channel 4 and at the same time edible marine animals 7 represented by such shellfishes as ear-shells, sea-urchins and top shells which live on the sea weeds 6 are cultured therein. Since the sea weeds 6 absorb nutritive salts of nitrogen, phosphorus, etc., which contaminate sea water, to grow up, nutritive salts in the sea water decreases and the sea water is purified. The grown sea weeds 6 is used as food for the edible marine animals 7, whereby the animals 7 are cultured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for purifying seawater while also cultivating edible aquatic animals that feed on aquatic plants, such as abalone, sea urchin, and turban shell.

[Conventional technology]

Conventional seawater purification methods involve growing aquatic plants in sea channels to allow them to absorb nutrients such as nitrogen and phosphorus that are contained in seawater and cause eutrophication. There are ways to purify seawater.

[Problem to be solved by the invention]

However, according to the conventional method, since aquatic plants in sea channels continue to grow, it is necessary to remove grown seaweed from sea channels at predetermined intervals, making it difficult to implement the purification method. Although it requires a lot of effort, the problem is that the effect is limited to simply purifying seawater.

This invention was made in view of these conventional problems, and aims to eliminate the need for removing aquatic plants and to obtain byproducts of seawater purification.

[Means to solve the problem]

The seawater purification method of the present invention involves growing aquatic plants using nutrients contained in seawater in a waterway through which the seawater passes, removing the nutrients from the seawater, and growing edible aquatic animals using the aquatic plants as food. This prevents the plants from overgrowing and cultivates edible aquatic animals.

[Effect]

Eutrophic salts such as nitrogen and @ contained in seawater in sea channels are absorbed as nutrients for plant growth, thus preventing seawater from becoming eutrophic and purifying it.

On the other hand, since the aquatic plants grown using the nutrient salts serve as food for edible aquatic animals such as abalone and sea urchins, overgrowth of the plants can be prevented and edible aquatic animals can be cultivated.

If the amount of plants consumed by the animals is adjusted by adjusting the number and type of food animals in accordance with the amount of plant growth, an appropriate amount of plants will always be distributed in the waterway.

〔Example〕

FIG. 1 is a cutaway perspective view of equipment directly used in carrying out the method of the invention.

With this equipment, seawater contaminated with eutrophic salts is introduced into the lower side of the filtration tank 2 through the supply pipe 1, and this seawater is passed from the bottom to the top of the filtration tank 2, where impurities are removed.
The air is aerated by flowing down from the top surface of the filtration tank 2 to the sides. The aerated seawater passes through the partition net 3 to reach the purification channel 4, passes through this, passes through the partition net 5 on the downstream side, and is then discharged from the discharge pipe 6.

In the purification waterway 4 where the upstream side and the downstream side are separated by a partition net 3.5, seaweed 6 (for example, Ulva, Agonori, Amanori, etc.) is grown as aquatic plants, and
Abalone that feeds on seaweed 6.

Edible aquatic animals 7, represented by seafood such as sea urchins and turban shells, are farmed.

Seaweed 6 grows by absorbing nutrient salts such as nitrogen and phosphorus that are contained in seawater and contaminates it by eutrophicating it, so this absorption reduces the nutrient salts in seawater. Then, the seawater is purified and discharged into the sea from the discharge pipe 6. Here, the amount of seawater per unit time suitable for seawater purification is determined in relation to the amount and type of seaweed 6, and the suitable amount of seawater is supplied from the supply pipe I.

The grown seaweed 6 is provided for food by the aquatic animals 7, and the edible aquatic animals 7 are thereby cultivated.

By balancing the amount of increase due to the growth of the seaweed 6 and the amount of decrease due to the above-mentioned consumption, approximately the same amount of seaweed 6 is always grown in the purification waterway 4. Therefore, in this case, the seawater purification rate can be maintained approximately the same at all times. The amount of seaweed 6 reduced by eating can be adjusted by adjusting the amount, type, etc. of the edible animal 7.

In this way, the seaweed 6 can remove eutrophic salts from the seawater and purify the seawater, and at the same time, it is possible to cultivate edible aquatic animals 7 using the growing seaweed 6 as food, thereby achieving seawater purification. In addition, edible aquatic animals can be obtained as a by-product. In addition to the seaweed 6, the aquatic plants may include seaweed (e.g., eelgrass), and the edible aquatic animals include, in addition to the sea urchins and abalone, crustaceans and fish that eat aquatic plants. You can.

〔Effect of the invention〕

As explained above, in this invention, 1. the work of removing aquatic plants that grow and contribute to the purification of seawater is not only unnecessary every time the aquatic plants are used as food for edible aquatic animals; Edible aquatic animals that are farmed using plants as food also have the effect of being obtained as by-products.

[Brief explanation of the drawing]

FIG. 1 is a cutaway perspective view showing an example of equipment directly used in carrying out the present invention. 6... Seaweed (aquatic plants), 7... Edible aquatic animals.

Claims (1)

[Claims] (1) By growing aquatic plants using nutrients contained in seawater in a waterway through which seawater passes, removing the nutrients from the seawater, and growing edible aquatic animals using these plants as food, the plants can flourish. A method for purifying seawater, which is characterized by preventing water pollution and cultivating edible aquatic animals.