JP2011229405A5 - - Google Patents

Description

(2) Drug bath method The drug bath method uses the action of chemicals such as sodium pyrophosphate, sodium percarbonate, disodium phosphate, formalin, and glacial acetic acid to eliminate parasites from fish. To do. However, there is a problem that the drug contaminates the surrounding seawater. As a chemical bath method, the following methods have been conventionally performed.
Patent Document 1 discloses that a parasite can be dewormed from a fish infected with a parasite such as a beetle by ferulic acid and lactic acid.
Patent Document 2 discloses a method for suppressing and preventing parasitic diseases in marine cultured fish by administering a parasitic inhibitor containing a cacao bean composition as an active ingredient.
Patent Document 3 discloses a method of treating fish infected with pathogenic microorganisms and parasites by adding δ-aminolevulinic acid to a feed or an aquarium.
Patent Document 4 discloses that a benzimidazole-based drug is used as an active ingredient as a pest control agent and a pest control method parasitic on trough puffer fish.
Patent Document 5 discloses a method for treating and preventing fish succiticosis using stabilized chlorine dioxide or chlorite, organic carboxylic acid and hydrogen peroxide. The scoutica ciliate penetrates deeply into the fish body, and unlike other parasitic diseases, it cannot be expected to be anthelmintic by a chemical bath. Conventionally, formalin that has been conventionally used has been completely prohibited from being used for cultured fish.

(4) Other methods Other methods, Patent Documents 10 and 11, by diffusion of the active oxygen species generated by irradiating ultraviolet rays to an aqueous solution containing ions to photocatalyst activity in water There has been disclosed a photocatalytic water generation apparatus that can function as an oxygen species and can perform sterilization of microorganisms, parasitic worms, and protozoa by utilizing this water oxidation reaction. However, in order to kill parasites by ultraviolet rays, high output is required, which is not suitable for use in aquaculture.
Patent Document 12 discloses a fish vaccine as a method for activating immunity of fish, particularly a method for activating immunity against fish parasitic disease, in order to suppress the occurrence of moribund due to parasitic disease of cultured fish. Although it is in the research stage, it is still not practical.

(5) Method using ozone water Non-Patent Document 1 describes the bactericidal effect of ozone, which is an oxidizing agent, on fish pathogenic microorganisms.
According to Non-Patent Document 2, ozone water is suitable for treatment of breeding water and tools, and is effective in 5-10 minutes at a concentration of 0.3-0.5 ppm. However, it is disclosed that in the breeding tank, it is necessary to reduce the concentration to 1/100 in order to avoid the influence of bromic acid on the cultured fish due to the reaction with bromide in seawater.
Non-patent document 3 reports an example in which ozone water was able to prevent seratomixosis and myxosomal parasitic infections by treatment at 0.3 ppm for 5 minutes.
When bromide ions are present in seawater , they react with ozone to generate residual and harmful bromate ions, so it is preferable to remove them in advance.
However, conventionally, in the method using ozone water, as a method for controlling ectoparasites that are parasitic on cultured fish, which is the subject of the present invention, in particular, such as aphids and scallops that parasitize thick fish such as trough fish. There was no known eradication of ectoparasites.

Conventionally, ozone water is generally produced using a discharge-type ozone gas generator. Ozone water of several ppm can be easily produced, and is used in the fields of water purification and food washing. However, discharge ozone generator has been limited to the field of use for the following reasons.
(A) When dry air is used as a raw material, NO _x is by-produced. In order to obtain a high concentration gas, a pure oxygen raw material must be used.
(B) It requires two steps of once generating ozone as a gas and then dissolving it in water.
(C) Since the concentration is lower than that of the electrolytic method described later, it is difficult to dissolve.
(D) Since the generated power source is high voltage and high frequency, it is difficult to reduce the size.
(E) In the ozone water generating device by discharge, it takes time (a waiting time of several minutes) until the ozone gas generation ability is stabilized, and it is difficult to instantaneously prepare ozone water having a constant concentration.
For this reason, it is suggested that the discharge-type ozone gas generator is not suitable for use on aquaculture farms, particularly on the coast.

As a method for producing ozone water, in addition to the above-described discharge method, a method for producing ozone water by electrolysis is known. This electrolysis method is inferior in electric power unit compared to the discharge method, but has a high concentration of ozone gas. In addition, it is widely used in special fields such as electronic component cleaning due to the characteristics that water is easily obtained. Since a DC low-voltage power supply is used in principle, it has excellent instantaneous response and safety, and is expected to be used as a small ozone gas and ozone water generator.
In order to efficiently generate ozone gas, it is essential to select an appropriate catalyst and electrolyte. Known electrode materials include noble metals such as platinum, α-lead dioxide, β-lead dioxide, glassy carbon impregnated with fluorocarbon, and diamond. As an electrolyte, an aqueous solution containing sulfuric acid, phosphoric acid, fluorine group and the like has been used, but it is inconvenient to handle and has not spread. On the other hand, as described in Non-Patent Document 5, a water electrolysis cell using a solid polymer electrolyte as a diaphragm and using water as a raw material is easy to manage and is widely used. If lead dioxide which is a conventional catalyst is used, ozone gas having a high concentration of 12% by weight or more can be obtained.

Using solid polymer electrolyte membrane as a diaphragm, the water electrolysis cell for the raw water and the raw material, Patent Document 13, the conductive diamond are disclosed to be useful as an electrode for functional water (containing ozone water).
Moreover, in patent document 14, the method of taking out as ozone water before gasifying is disclosed by giving sufficient flow rate to the solution of an electrode vicinity.
Patent Document 15 proposes an electrolyzed water spray device that dissolves ozone, and in particular, a small spray device that sprays the obtained electrolyzed water in a mist form.
Patent Document 16 provides a sterilizing and purifying apparatus that introduces the generated ozone water into a sterilization washing tank and performs sterilization and deodorization by a combination of ultrasonic action and sterilization action of ozone water.
Furthermore, as described in Non-Patent Document 6, in recent years, basic research and practical application of fine bubbles called nanobubbles and microbubbles have been studied. Recent developments are described in the latest microbubble technology.
In Patent Documents 17 and 18, it is disclosed that nanobubbles mainly composed of a gas such as oxygen and ozone-containing bubbles that are microbubbled have a cleaning effect. This technology has been reported to be effective in inactivating norovirus in the oyster.

Conventionally, as described above, various studies have been made as a method for controlling parasites. However, none of the methods has been sufficiently solved. As a method of controlling cultured fish,
(A) It is possible to eliminate parasites, especially damselfly and aphids, in a short time. (B) It is possible to safely work on site without the need for preparation and storage. (C) It is possible to dispose of treated water as it is. (D) It is preferable to exert the extermination effect without affecting the ecology of the cultured fish. It is important to provide effective on-the-job methods that fishers can implement.

Further, an electrolytic hydrogen peroxide generator is installed near the electrolytic ozone generator 1, and the electrolytic hydrogen peroxide solution generated by the electrolytic hydrogen peroxide generator is put into the electrolytic ozone water tank 4. Effective extermination can be carried out by exterminating ectoparasites that parasitize cultured fish with thick outer skin using a mixture of electrolytic ozone water and electrolytic hydrogen peroxide water. When mixed water of electrolytic ozone water and electrolytic hydrogen peroxide water is used as described above, the surface of the parasite is oxidized by these substances and reactive oxygen species generated by accelerated oxidation, and normal life activity is inhibited. It is thought that shedding from the parasitic site and extermination are induced. When mixed water of ozone and hydrogen peroxide is used, active oxygen is likely to be generated by accelerated oxidation treatment. The concentration ratio ozone: hydrogen peroxide at this time is preferably in the range of 1: 0.1 to 1:10. If the amount of hydrogen peroxide is less than this, an accelerated oxidation treatment effect cannot be expected. On the other hand, if the amount is larger than this, the decomposition of ozone becomes faster and only the effect of hydrogen peroxide can be obtained.

FIG. 2 shows another embodiment of a method for controlling ectoparasites such as aphids and bark beetles parasitizing cultured fish according to the present invention, and an aquaculture ginger 5 is provided in a marine farm far from the coast. The electrolytic ozone generator 1 is provided on the ship 6, and the electrolytic ozone water tank 4 is provided on the ship or on the sea near the ship 6.
In another compartment isolated from cultured fish preserve 5 provided electrolytic ozone water tank 4, the ozone water is injected into the tank 4, the fish in aquaculture pens to feed transferred to compartment, after processing, fish be released to the original raw bamboo 5. The processing compartment may be a container using ozone water for synthesis and transportation. In order to prevent the release of ozone gas from the ozone water, a compartment or container having a lid is preferable. The amount of water in the compartment separated from the seawater is about 1 to 10 m ³ , although it depends on the number of fish and the weight. It is effective to repeat the removal method several times.
The ozone water is synthesized on the ship or in the fishing port by sending the raw water from the container filled with the raw water to the electrolytic cell.

An example of the electrolytic ozone generator used in the present invention will be described in detail.
(1) Electrolytic ozone generator
An example of a conductive Kaishiki ozone generating cell shown in FIG. In FIG. 3, 7 is an anode, 8 is a cathode, 9 is an ion exchange membrane, and the electrolytic ozone generating cell is divided into an anode chamber including the anode 7 and a cathode chamber including the cathode 8 by the ion exchange membrane 9. .
The distance between the electrodes is preferably 0.1 mm to 50 mm. If it is closer than this, a short circuit is likely to occur due to contact, and if it is farther than this, the cell voltage increases. The distance between the electrodes is more preferably about 0.1 mm to 2 mm. Each electrode chamber is provided with a raw water supply port and discharge port, and a generated gas discharge port. Synthesized electrolytic ozone water, it is also possible to store the indoor electrodes, it is preferable to store in a separate container. As the tank material, a material that is not affected by electrolyzed water is selected. If there is no problem, PE resin or the like may be used.

(3) Anode material The anode base material of the anode 7 is limited to valve metals such as titanium and niobium, alloys thereof, and silicon. Platinum, diamond, and lead dioxide can be used as the catalyst.
Diamond is considered promising as an electrode material because it can control electrical conductivity by doping. The diamond electrode is inactive against the decomposition reaction of water, and ozone and hydrogen peroxide are reported to be generated in addition to oxygen in the oxidation reaction. The catalyst only needs to be present on a part of the anode, and there is no problem even if a part of the substrate is exposed. A typical hot filament CVD method will be described below. Using a hydrocarbon gas such as methane CH ₄ as a carbon source, or an organic substance such as alcohol, it is sent together with hydrogen gas into the CVD chamber, and while maintaining a reducing atmosphere, the filament is heated to a temperature 1800-2400 ° C. at which carbon radicals are generated. To do. At this time, an electrode base material is placed in a temperature (750-950 ° C.) region where diamond is deposited. The hydrocarbon gas concentration with respect to hydrogen is 0.1-10 vol%, and the pressure is 20 hPa-1013 hPa (1 atm).
In order for diamond to obtain good conductivity, it is indispensable to add a trace amount of elements having different valences. The preferred content of boron B or phosphorus P is 1 to 100,000 ppm, more preferably 100 to 10,000 ppm. Trimethylboron (CH ₃ ) ₃ B is used as the raw material compound, but it is also preferable to use boron oxide B ₂ O ₃ , pentoxide 5 phosphorus P ₂ O _5, etc., which are less toxic. The shape of the electrode substrate, the grain terminal, fibers, plates, perforated plates, rods, or the like is possible.

[Comparative Example 1]
When the aphid excised from the 15 cm long trough puffer used in Example 1 was treated with hydrogen peroxide (600 ppm), it took 5 minutes for the aphid to die. Incidentally, it was treated with Eramushi and gill meat pieces while parasitic in the hydrogen peroxide solution (600 ppm) in the gill portion of Fugu, Eramushi and gill meat piece could not kill even 20 minutes. The pufferfish infested with aphids did not recover. Upon dissection, the survival of the aphid was confirmed.
In the above-described embodiments, the farmed fish having a thick outer skin such as trough puff was described, but the present invention is not limited to these and can be applied to other farmed fish. Moreover, as an ectoparasite, it can apply also to ectoparasites other than aphid and aphid.