JP2002138003A - Preventive structure for adhesion of aquatic creature and method for preventing adhesion of aquatic creature - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide several kinds of structures preventing adhesion of aquatic creature in such a way as to be entirely free from exerting adverse effect on the environments without using special agents or devices. SOLUTION: Carbide powder is fixed to a contact surface with water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various structures and a method of preventing underwater organisms from adhering to water contact surfaces.

[0002]

BACKGROUND OF THE INVENTION It is well known that algae and shellfish adhere to structures that are constantly or frequently in contact with water, such as seawalls, piers, drains, and the bottom of ships. Above all, in a drain outlet of a factory or a power plant, the operation of the factory or the power plant may be hindered as a result of the drain outlet being blocked by adhesion of algae or shellfish. In addition, the inhabitation (sea settlement) of fish and shellfish near the cooling water intake and drainage of the power station installed on the coast is also a serious operational problem. In particular, since the water temperature is relatively high near the drain, fish and shellfish are likely to inhabit, and in extreme cases, the drain may be blocked and the operation may be stopped.

[0003] In order to solve this problem, protection nets are installed at drain outlets, water temperature is controlled at drain outlets, and ship bottom paint is used. No drastic solution has been obtained to prevent adhesion to structures.

On the other hand, in a ship, algae or shellfish attached to the bottom of the ship increase the resistance of the bottom of the ship.
Undesirable problems such as deceleration of ships frequently occur.
Especially for long voyages, the bottom of the ship,
There is also a problem that shellfish such as oysters are attached and forced to decelerate, and the fuel consumption increases.

As a countermeasure, it has been known to apply a complex ion-based or copper ion-based ship bottom paint which has a repellent effect on these marine organisms, but these paints are dissolved in seawater. It pollutes the environment, and furthermore, its components are taken up into seafood from seawater, and then, through the so-called food chain, in which humans ingest the components concentrated in the body of the fish and shellfish, and ultimately harm human health. Therefore, measures have been taken to prohibit the use of these bottom paints.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention
Various structures that prevent the attachment of underwater organisms can be used in conjunction with methods to prevent the attachment of underwater organisms without using special drugs or equipment, and without causing any adverse effects on the environment. It is something to offer.

[0007]

That is, the gist of the present invention is as follows. (1) An underwater biofouling preventive, comprising a carbide powder fixed to a surface that comes into contact with water.

(2) The underwater biofouling preventive according to (1), wherein the carbide is activated carbon.

(3) In the above (1) or (2), the carbide is obtained by carbonizing garbage solid fuel which has been processed into a predetermined shape through crushing, drying and forming of garbage. A body for preventing underwater organisms from adhering.

(4) A method for preventing underwater organisms from adhering, comprising fixing a powder of a carbide to a surface that comes into contact with water with a binder.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the experimental results which led to the present invention will be described in detail. First, length: 30mm, width: 30
mm and thickness: using a 2 mm square mild steel sheet, (i)
Untreated material with no treatment on the front and back, (ii) coating material with phthalic acid paint, which is a general paint on the front and back, (iii) treatment with a mixture of phthalic acid paint and activated carbon applied on the front and back Each of the three samples was put into a polypropylene bag and immersed in the sea at a depth of about 50 to 100 cm below the sea surface.

After immersion for a predetermined period, each sample was collected and taken out of the bag, and dispersed in a 3% aqueous sodium chloride solution to remove mud and the like adhering to the sample surface. Then, about 1 mm square specimens taken from each sample,
After being inserted into a polypropylene disposable test tube, a filter paper cut into strips was put into the test tube to remove the aqueous sodium chloride solution adhering to the surface of the test piece.

Next, an MT of 5 mg / ml was added to each specimen.
T aqueous solution 3- (4,5-dimethylthiazol-2-y
l) -2,5-diphenyltetrazplium bromide｝ 3.0
After adding 30 ml at room temperature for 30 minutes, the liquid phase was removed by the gradient method, and the filter paper cut into strips was put into the test tube in the same manner as described above. MTT aqueous solution was removed. Then, 3.
0 ml of 1 mM hydrochloric acid added n-propanol (normal-prOH)
Was added and stirred for 30 seconds, and the absorbance at 570 nm of the visible absorption spectrum of the solution was measured.

Here, it is known that MTT is reduced by the activity of a reductase system in mitochondria of living cells to form a formazan dye (maximum absorption wavelength: 570 nm). Then, when the sample is immersed in an MTT aqueous solution, if the marine microorganisms adhere to the surface of the sample, the formazan dye is generated by the enzyme in the mitochondria of the living cells, and the colorimetric analysis of the marine microorganisms of the sample is performed. Adhesion ability can be evaluated.

Therefore, the amount of living organisms attached to the test pieces was compared by dividing the absorbance of the n-propanol solution by the absorbance of the mild steel sheet. That is, the larger the value is, the more the organism is attached. The absorbance of the n-propanol solution is represented by the height of the peak from the baseline, and the measurement range of the absorbance varies depending on the density of the sample solution. As shown in Table 1, it can be seen that the treatment material in which the mixture of the phthalic acid paint and the carbide (activated carbon) was applied to the front and back surfaces, that is, the treatment material in which the carbide was fixed on the front surface, had extremely low adhesion of organisms. .

[0016]

[Table 1]

Here, the reason why the adhesion of the underwater organisms is suppressed by fixing the carbides is not necessarily clear, but is considered as follows. That is, the carbide is
It is considered that the distribution of the substance concentration is higher in the vicinity of, for example, the carbide in seawater than in the average of the seawater because of having the adsorption ability by a large number of micropores. It is presumed that heavy metals such as NaCl, Cu, and Zn, which are disliked by living organisms, exist in this high concentration range.

Next, the inventors conducted the same experiment as described above for various carbides. That is, (A) crushing of garbage, processed into a predetermined shape through drying and molding,
Carbide obtained by carbonizing garbage solid fuel, (B) coconut shell activated carbon, (C) activated carbon obtained by carbonizing rawan, (D) silica beads, and (E) crushed granules of concrete Approximately 5 g were individually placed in polypropylene bags, and a total of 20 bags each of 4 bags of the same type were prepared.
It was immersed in the sea at a depth of 100 cm for various periods of 1-4 months.

Then, every one month, two months, three months and four months after the immersion, one bag of each type is collected from the sea, and each collected material is dispersed in a 3% aqueous sodium chloride solution. Mud and the like adhering to the surface were removed. After that, a sample of about 1 mm square collected from each collected material was inserted into a polypropylene disposable test tube, and then a strip of filter paper was put into the test tube, and attached to the surface of the sample. The aqueous sodium chloride solution was removed.

Next, an MT of a concentration: 5 mg / ml was added to each test piece.
T aqueous solution 3- (4,5-dimethylthiazol-2-y
l) -2,5-diphenyltetrazplium bromide｝ 3.0
After adding 30 ml at room temperature for 30 minutes, the liquid phase was removed by the gradient method, and the filter paper cut into strips was put into the test tube in the same manner as described above. MTT aqueous solution was removed. Then, 3.
0 ml of 1 mM hydrochloric acid added n-propanol (normal-prOH)
Was added and stirred for 30 seconds, and the absorbance at 570 nm of the visible absorption spectrum of the solution was measured.

Further, the collected test piece was freeze-dried overnight, and then its weight was measured. Then, the absorbance per unit weight was calculated by dividing the absorbance of the n-propanol solution by the weight of the test piece. The larger the value is, the more the organism is attached.

As shown in Table 2, the carbide (A) obtained by carbonizing refuse solid fuel, which has been processed into a predetermined shape through crushing, drying, and molding of refuse, is obtained by the following method. In other words, compared to coconut shell activated carbon (B), activated carbon made of Lauan wood (C) or silica beads (D), it can be seen that there is a lower level of biofouling. In addition, since a large amount of biofouling was observed in the crushed granules of the concrete during the two-month immersion period, subsequent measurements were omitted.

[0023]

[Table 2]

Here, the reason why the adhesion level of aquatic organisms in the carbide (A) obtained by carbonizing refuse solid fuel is particularly low is not necessarily clear, but can be considered as follows. In other words, the carbide (A) contains a large amount of volatile components and starts from solid waste fuel,
Other carbides, i.e., coconut shell activated carbon (B), activated carbon (C) made of Lauan wood and silica beads (D), possessing a large number of micropores, and carbide (A) itself has a small amount of impurities, for example, It is presumed that it may contain CaO, SiO ₂ or Al ₂ O ₃ .

Further, the carbide (A) is added to the above-mentioned mild steel sheet.
Table 3 shows the results of performing the same experiment as described above while fixing the amount of in various ways. As shown in Table 3, when the area where the carbide is exposed is less than at least 25% of the entire surface of the mild steel sheet, the effect of suppressing the adhesion of underwater organisms is reduced. Therefore, it is advantageous to adjust the exposed area of the carbide to 25% or more of the entire mild steel sheet.

[0026]

[Table 3]

In order to fix a carbide on the surface that comes in contact with water to prevent the adhesion of aquatic organisms, (1) As a binder,
Using a paint or cement mortar, etc., mix and apply or spray a carbide on this binder. (2) Spray and fix the carbide on the part coated with the binder on the surface.
Such techniques are advantageously adapted.

Further, as the carbide to be used, those having an average particle size of 0.05 to 0.2 mm are advantageously suitable. In other words, in order to reduce the average particle size of the carbide to less than 0.05 mm, special crushing treatment is required for the carbide, and the crushing cost is high.On the other hand, if the particle size exceeds 0.2 mm, it is used by mixing or spraying. In this case, it is difficult to obtain a uniform fixed surface.

Incidentally, the carbide obtained by carbonizing the above refuse solid fuel can be obtained through the following production procedure. First, general garbage such as municipal garbage, household garbage,
Metals, glass, and ceramics are removed from industrial waste, general waste, and shredder dust and other debris obtained by crushing household electrical appliances and automobile parts. After that, the obtained refuse mainly composed of combustibles is crushed and dried, for example, using steam as a heat source. Then, after the dried refuse is crushed again, metals are removed if necessary, and then the refuse is molded into a predetermined shape to produce refuse solid fuel.

Next, the solid waste is subjected to dry distillation.
That is, the carbonization treatment is performed, for example, in order to control the oxygen concentration in the furnace to 1 vol% or less by adjusting the amount of air supplied to the carbonization furnace and to raise the carbonization temperature to 600 ° C. or higher, preferably to suppress the generation of dioxin. At 800 ° C or higher.
The carbonaceous powder thus obtained is provided as a carbide powder for preventing underwater organisms from adhering.

The carbonization gas generated during the carbonization treatment is:
When complete combustion is performed in the combustion device installed on the exit side of the carbonization furnace, the residence time of the combustion gas in the temperature range of 800 ° C or more is set to 2 seconds or more, and the combustion gas is rapidly cooled to reliably prevent the generation of dioxins. be able to.

[0032]

According to the present invention, underwater organisms can be prevented from adhering without using any special drugs or devices, and without adversely affecting the environment. It is possible to safely provide a function of preventing underwater organisms from attaching to various structures that dislike the attachment of underwater organisms.

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasuyuki Yamaguchi 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo F-term in Kawasaki Steel Corporation (reference) 2B121 AA06 AA19 CC28 EA30 FA16 4H011 AD01 BA01 BB18 BC18 DA02 DD01

Claims (4)

[Claims] 1. An underwater biofouling preventive comprising a carbide powder fixed to a surface that comes into contact with water. 2. The underwater biofouling preventive according to claim 1, wherein the carbide is activated carbon. 3. The carbide according to claim 1 or 2,
An underwater biofouling preventive, characterized by being obtained by carbonizing garbage solid fuel, which has been processed into a predetermined shape through crushing, drying and molding of garbage. 4. A method for preventing underwater organisms from adhering, comprising fixing a powder of a carbide to a surface in contact with water with a binder.