JPH0121122B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to an agent for preventing the adhesion of seawater animals in channels, plants, etc. that utilize seawater. In recent years, the industrial use of seawater has increased significantly, and large amounts of seawater are now used in temporary quantities, for example, in thermal power plants, steel mills, petrochemical industries, and the like. Furthermore, on ships, it is used to cool boilers' double water units. However, when using seawater in this way,
Adhesion problems caused by various animals that live in seawater, such as mussels, barnacles, water bugs, and bryozoans, cannot be ignored. Creatures that cause particularly severe damage include mussels and barnacles. When many of these seawater animals attach and grow in waterways, they narrow the waterways, and when they fall off and flow into condensers and heat exchangers, they reduce cooling efficiency.Furthermore, when they clog condenser tubes, seawater This causes turbulent flow and mechanically accelerates metal corrosion. To prevent such damage, a method of injecting drugs is usually used. Typical agents conventionally used include liquid chlorine, effective chlorine generators such as sodium hypochlorite, tri-n-propyltin, tri-n-butyltin, tri-n-phenyltin chlorides, Examples include organic tin compounds such as oxides and hydroxides, but these agents have residual toxicity and cumulative toxicity, and are widely considered to destroy the ecological environment of seawater organisms. In addition, in the case of effective chlorine generators, there is odor, corrosiveness to metal materials,
There are problems such as foaming. Furthermore, in the case of liquid chlorine, there are also problems such as danger during transportation and work stability during injection. In addition, organic tin compounds also have problems such as having a unique irritating odor, being likely to cause irritation if they come in contact with the skin, and being less effective against soft-type contaminant organisms that do not have shells, such as water beetles. Therefore, without using these organic chemicals, it is often done manually to remove the deposits from flow paths, plants, etc., but this requires a huge amount of cost and removes the deposits. As corrosive gases are generated due to the death of living organisms and fill dark spaces, it is not uncommon for personal accidents due to poisoning to occur. Therefore, there is a demand for the development of a new, safe drug to replace conventional drugs, and the present inventors focused on hydrogen peroxide as such a drug. Hydrogen peroxide itself has low toxicity, and since it decomposes into water and oxygen gas, it has the advantage that there is no need to worry about causing environmental problems due to residual or accumulated poisons. However, although hydrogen peroxide itself is effective in preventing the adhesion of marine animals, it has the disadvantage that a relatively large amount is required to obtain a satisfactory adhesion-controlling effect, and it is too expensive. Therefore, the present inventors have conducted extensive research into drugs that produce effective and synergistic effects when combined with hydrogen peroxide. As a result, while in many cases only an additive effect or a slight synergistic effect was observed, a combination having an extremely significant synergistic effect was discovered, and the present invention was achieved. That is, the present invention is a marine animal adhesion prevention agent characterized by containing hydrogen peroxide and hydroxylamine or a water-soluble salt thereof as active ingredients. In addition to hydrogen peroxide, hydrogen peroxide also includes substances that generate hydrogen peroxide in the presence of seawater. Such compounds include, for example, the respective hydrogen peroxide adducts such as carbonates, borates, monophosphates, diphosphates, metasilicates and urea, and the peroxides of alkali metals and alkaline earth metals. Examples include metal peroxides such as peroxides. Hydroxylamine or its water-soluble salt is
Since hydroxylamine is an unstable compound, it is preferred to use hydroxylamine sulfate or hydroxylamine hydrochloride. The present invention is based on the novel finding that a remarkable synergistic effect can be obtained by using hydrogen peroxide and hydroxylamine together on marine animals. For example, in the case of mussels, metamorphosis occurs from juveniles to adults through the larval stages of trochophore, D-shaped larva, and ambo stages, and in the case of barnacles, metamorphosis occurs through the larval stages of nauplii and cypris to adults. However, attachment is generally thought to occur during these larval stages. However, after combining hydrogen peroxide and hydroxylamine or its water-soluble salts, the larvae cease to be active, leading to asphyxia, or become attached to the larvae at concentrations that would have little effect with each agent alone. It also prevents further growth. In the present invention, hydrogen peroxide and hydroxylamine or a water-soluble salt thereof are added to the seawater system in the required amounts, but the method of addition may be to mix and adjust both drugs in advance and add them. Both agents may be added separately. When mixing in advance, it is necessary to keep the pH of the adjustment solution acidic using hydroxylamine sulfate or hydroxylamine hydrochloride for storage stability. When adding the drugs separately, there are no particular restrictions on the order of addition, etc., but it is preferable that the addition of the next drug is started while the first drug added remains in the seawater. In addition, the amount of hydrogen peroxide and hydroxylamine or water-soluble salt used varies depending on the temperature of the seawater contamination, the type of animal attached, etc., but in general, the concentration of hydrogen peroxide in the seawater system is 0.01~
50 ppm, preferably 0.1 to 10 ppm, and hydroxylamine or its water-soluble salt in an amount of 0.01 to 10 ppm, preferably 0.1 to 5 ppm, and 0.5 to 24 ppm per day.
Just add time. In addition, when hydrogen peroxide is in the range of 0.05 to 1 ppm,
0.05 hydroxylamine or its water-soluble salt
Even if added at ~10 ppm, it does not have a significant effect of stopping the activity of adherent larvae, but since it significantly stops the growth after attachment, a substantially sufficient adhesion control effect can be obtained. Although it is preferable to repeat the above treatment, it is not necessarily necessary to perform it every day; for example, in winter when the seawater system is less contaminated, it may be performed once every 2 to 3 days. The present invention has succeeded in controlling the adhesion of seawater animals extremely economically and efficiently,
Moreover, it is of extremely high industrial value and poses no pollution problems. Examples will be described below. Example 1 The effects of the drug of the present invention were tested using D-shaped mussel larvae that were artificially hatched and reared by the temperature stimulation method, and barnacle cypris larvae that were hatched from developed adults and reared. For the test, 20ml of seawater containing D-shaped larvae or Cypris larvae (density of approximately 50 larvae/ml) was collected in a φ24mm test tube, the drug was adjusted to a specified concentration, and the activity of the larvae was observed using a stereomicroscope over a period of 24 hours. The time required to stop the activity 100% was determined. In this test, a 35 w/w % aqueous solution of hydrogen peroxide was used, and hydroxylamine hydrochloride (NH ₂ OH.HCl) was used as hydroxylamine or its water-soluble salt. The results are shown in Table 1.

【table】

[Table] Example 2 A one-month water flow test was conducted in the spring, when the mussels are attached, in a temporary model waterway installed in a certain steel factory in the coastal area. The model waterway consists of 5 rows of waterways, and the seawater flow rate of each channel is 10m ³ /
hr, average flow velocity is 0.3 m/s. In this test, a 35 w/w % aqueous solution of hydrogen peroxide was used, and hydroxylamine sulfate [(NH ₂ OH) _{2.H 2} SO ₄ ] was used as hydroxylamine or its water-soluble salt. Second result
Shown in the table.

【table】

[Table] Comparative Example 1 In the same manner as in Example 2, the effect of using hydrogen peroxide or hydroxylamine sulfate alone was tested. The results are shown in Table 3.

[Table] Example 3 A one-month water flow test was conducted in the same model waterway as in Example 2 during the summer season when barnacles are attached.
The drugs used were the same as in Example 2. The results are shown in Table 4.

【table】

[Table] In addition, a large number of water beetles were observed in the waterways of the untreated plot, but none were observed in test plots No. 1 to 4. Comparative Example 2 In the same manner as in Example 3, the effect of using hydrogen peroxide or hydroxylamine sulfate alone was tested. The results are shown in Table 5.

【table】

Claims (1)

[Claims] 1. An agent for preventing adhesion of marine animals, which contains 0.1 to 10 ppm of hydrogen peroxide and 0.1 to 5 ppm of hydroxylamine or a water-soluble salt thereof as active ingredients.