JP2995472B1 - Algae killing methods in water systems - Google Patents

Abstract

Abstract: [PROBLEMS] To reduce the generation of algae in various water systems such as pools, fire prevention water, reservoirs, fountains, waterways, industrial water, industrial cooling water systems, cooling water systems for air conditioning, etc., with a small amount of added algicide. The present invention also provides a method for killing alga in a water system with significantly improved algicidal power. SOLUTION: An α-position and / or β-position with respect to a bromine atom.
A solution containing an organic nitro bromine compound having 1 to 3 nitro groups as substituents at the carbon atom at the position 1 is a chlorinating agent selected from sodium hypochlorite, calcium hypochlorite and chlorine dioxide. The method is characterized in that seeds or two or more kinds are mixed, held for 1 to 30 minutes, and then charged into an aqueous system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a pool, fire protection water,
The present invention relates to an algicidal method in a water system that suppresses the generation of algae in various water systems such as a reservoir, a fountain, a water channel, an industrial water, an industrial cooling water system, and a cooling water system for air conditioning.

[0002]

2. Description of the Related Art In recent years, there has been an increasing awareness of restoring and using waterside environments that have been overlooked in the past. To make the urban environment a place with moisture,
Actively incorporate waterways, fountains, etc. into town planning,
A good example is the movement of taking a local pond or marsh into a water park as a place for residents to relax. Such activities are not just the quantity of water, but also the beauty of water. In addition, there is a movement to use water stored in an outdoor pool of a public facility such as a school in the event of an emergency as domestic water for use in a disaster. However, when algae are generated in the water of these reservoirs and facilities and the water quality is deteriorated, not only the appearance is deteriorated, but also an unpleasant odor and sanitary problems may occur.

[0003] In industrial applications, algae sometimes cause operational problems, and countermeasures are indispensable.

Algae are microorganisms having a green pigment called chlorophyll inside and living very normally in surface water, but differ from bacteria, fungi, yeasts and the like in that they require light. Many algae proliferate in the presence of trace amounts of nutrients such as phosphorus, nitrogen, potassium, magnesium, and iron in addition to light, and form a population in 2 to 4 days and proliferate.

[0005] Many drugs have been proposed to kill algae.
The main ones are chlorine, inorganic salts, organometallic compounds, rosinamines, quinones, amide derivatives, phenols, metal salts of pentachlorophenol and the like. Of these, chlorine agents are most widely used because of their low cost. Chlorine acts on the protein system which is a component of algae to produce chloramine and exerts a remarkable algicidal effect.Although algae resistant to chlorinated agents are also known, the residual chlorine concentration is 1.5 ppm or more. But many keep growing. Most of these algae that are resistant to chlorine agents are algae that secrete a large amount of a mucous substance on the cell surface, and protect themselves with this mucous substance. The main types of genus Tetraspora, Coccomyxsa, C
osmarium genus, Dictyosphaerium
Genus, diatom, Cyclotella, Synedra
In the genus, Nitzschia and cyanobacteria, Phormid
The genus ium and the like are known, and the fact that these algae have chlorine tolerance is described in the literature ("Algal disorders in waterworks" by Atsuhisa Sato and Yasuki Maga, 1996, pp. 18-39, Gihodo Shuppan and Sendai City Institute of Public Health) (No. 28, 1996)
Has also been reported.

With regard to the microbicidal action of bromine compounds, hypobromite is prepared from sodium bromide and sodium hypochlorite, and the microbicidal effect at a higher pH is superior to sodium hypochlorite alone. [American Water Treatment Association Water Reuse Symposium (JB Alleman et al., W
ater Reuse Symposium of Am
erican Water Works Associates
1987)], control of mussels by bromoacetic acid (Japanese Patent Publication No. 52-84), and suppression of algae reproduction by alkyl bromide acetate (Japanese Patent Publication No. 60-46082).
), The bactericidal activity of nitroalkyl bromide alone (JP-A-59-175406) is known, but its action on algae covered with a viscous substance is insufficient. Was.

[0007] It is known that the simultaneous use of an organic bromine compound and a chlorinating agent enhances the bactericidal activity due to the synergistic effect thereof. For example, there is a report that a chlorine agent activates an organic bromine-based bactericide [Vanja M. .King; Neu
tral / AlkalinePapermaking
221-227, 1990], the synergistic effect of the combined use of 2-bromo-2-nitro-1,3-propanediol and a chlorine agent (US Pat. No. 4,966,775), 2-bromo-2-nitro-1,3-propane There is a proposal (JP-B-63-62486) to improve the bactericidal effect by using a bactericide prepared in advance with diol and chlorine dioxide. Also, there is a proposal (JP-A-7-171575) that by acting on an aqueous system simultaneously with an organic bromine compound and a chlorinating agent, osmotic power is imparted and a bactericidal effect is enhanced.
However, these methods also have some effect on slimes with micrometer thickness, such as in bacteria and fungi, but on slimes with millimeter thickness, such as in algae. On the other hand, the penetrating power is not sufficient, and the algicidal effect is hardly achieved. Algae also has a cell wall and a cell membrane mainly composed of cellulose below the secretory layer, so that the algicidal effect is further inhibited.

[0008]

As described above, the effect of the conventional algicidal treatment is insufficient, and the replacement or cleaning of water is frequently performed for the adhesion of algae. This has been a major problem in terms of cost. In particular, in the case of a complex structure such as a fountain or a deep reservoir, the work of removing algae is troublesome and time-consuming, and the maintenance cost is enormous.

An object of the present invention is to provide an algicidal method which dramatically increases the algicidal activity and which is effective even against algae covered with a viscous substance in order to meet such demands. is there.

[0010]

SUMMARY OF THE INVENTION The present invention provides an extremely permeable active substance by mixing an organic nitrobromine compound and a chlorinating agent and maintaining the same for a limited period of time. The present inventors have found that even the covered algae have the ability to penetrate the mucous substance and directly act on the algae, and have accomplished the present invention.

That is, the invention according to claim 1 includes an organic nitro bromine compound having 1 to 3 substituents of a nitro group at the carbon atom in the α-position and / or the β-position with respect to the bromine atom. The solution is mixed with one or two or more chlorinating agents selected from sodium hypochlorite, calcium hypochlorite and chlorine dioxide, held for 1 to 30 minutes, and then poured into an aqueous system. The method according to claim 2, wherein the mixing ratio of the organic nitro bromine compound and the chlorine agent is such that the number of bromine atoms in the organic nitro bromine compound and the generation of the chlorine agent are reduced. This is an algicidal method in an aqueous system in which the ratio of the number of chlorine atoms of chlorine is 1: 1 to 1:10.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The organic nitro bromine compound used in the present invention has 1 to 3 substituents of a nitro group at the carbon atom at the α-position and / or the β-position with respect to the bromine atom. Wherein the bromine-carbon bond in the molecule is weakened by a nitro group. The use form of the organic nitrobromine compound is not particularly limited, but a form capable of reacting with a chlorinating agent in water, that is, dissolving itself in water,
It is mixed with a small amount of a water-soluble organic solvent and dissolved in water, or is in a liquid state at the target aqueous temperature.

Examples of such organic nitro bromine compounds include 2-bromo-2-nitro-1,3-propanediol, 2-bromo-2-nitro-1,3-pentadiol, and 1,1-dibromo. -2-nitro-2-acetoxyethane, 1-dibromo-2-nitro-1,3-acetoxypropane, 1,3-diacetoxy-2-bromo-2-nitropropane, 1,1-dibromo-1-nitropropanol And 2-nitro-3-bromo-n-butylmonobromoacetate. The organic nitro bromine compound may be used alone or in combination of two or more.

The chlorine agent used in the present invention has an oxidizing effect in water to generate available chlorine, and is selected from sodium hypochlorite, calcium hypochlorite and chlorine dioxide. In addition to using one type alone, 2
Mixing more than seeds can be used. The chlorine agent is added in the form of a solid, preferably a powder, but it can also be added in the form of an aqueous solution.

In the algicidal treatment method of the present invention, an organic nitrobromine compound is prepared as a solution having an appropriate concentration, a chlorinating agent is added to the solution, mixed and maintained for a certain period of time, and then injected into an aqueous system. With respect to the mixing ratio of the organic nitro bromine compound and the chlorine agent, the ratio of the number of bromine atoms in the organic nitro bromine compound to the number of chlorine atoms of available chlorine generated by the chlorine agent is preferably from 1: 1 to 1: 1.
0, more preferably in the range of 1: 1 to 1: 5.
This range is selected based on the finding that it is appropriate for both compounds to act efficiently. It is well known that chlorinating agents themselves have an algicidal action, and an excess of chlorinating agents does not hinder the manifestation of the effects of the present invention.

The preferred form of mixing the organic nitro bromine compound and the chlorine agent is as follows.
Alternatively, it is dissolved at a suitable concentration in water partially containing a water-soluble organic solvent, and a chlorinating agent is added thereto to cause a reaction. At this time, it is preferable that the liquid mixture is stirred gently, but it may be sufficient if the liquid mixture is uniformly mixed.

The solution concentration of the organic nitrobromine compound before mixing the chlorine agent is not limited in the present invention, but is generally 0.01 to 10% by weight. When the solution concentration is lower than 0.01% by weight, the reaction is slowed, while when the solution concentration is higher than 10% by weight, the reaction may be too vigorous.

The reaction time after mixing the chlorine compound with the organic nitrobromine compound is 1 to 30 minutes, preferably 2 to 10 minutes. If the reaction time is shorter than 1 minute, the effect of the present invention is not sufficiently exhibited, and if the reaction time is longer than 30 minutes, the effect may be reduced.

When mixing the organic nitrobromine compound and the chlorine agent, it is only necessary to add the chlorine agent to the solution of the organic nitrobromine compound.
It may be preferable to add a chlorine agent here.

When a mixed solution of an organic nitrobromine compound and a chlorine agent is added to an aqueous system, the amount of addition depends on the quality of the target aqueous system, the temperature, the type of algae in the water, and other conditions, and is determined uniformly. Although it is not a thing, generally 0.01 to 100 ppm, preferably 0.1 to 100 ppm, of bromine atoms in the organic nitrobromine compound is based on the amount of water in the aqueous system of interest.
10 ppm. When the amount is less than 0.01 ppm, the effect is small, and when the amount is more than 100 ppm, the effect is sufficiently high, but the effect is not increased for the added amount, which is uneconomical. Actually, observe the algae occurrence status of the water system,
It is preferable to change the addition amount, the addition frequency, and the like.

In the method of the present invention, a compound containing silver and copper ions, at the same time as other algicidal and germicidal treatment agents, dispersants, anticorrosives, scale inhibitors, as long as the effects of the present invention are not impaired. There is no limitation on adding or the like, or irradiating with ultraviolet rays.

The present invention relates to an organic nitro bromine compound,
It has been found that the algicidal action is dramatically increased by mixing with a chlorine agent to give an appropriate reaction time and then acting on the aqueous system. The organic nitrobromine compound and the chlorine agent originally have a certain algicidal activity even when used alone.However, by mixing these organic nitrobromine compound and the chlorine agent, and taking an appropriate reaction time, the organic nitrobromine compound and the chlorine agent have osmotic power. , Exhibit a more pronounced algicidal effect. This is because a chlorine agent acts on a bromine-carbon bond in an organic nitrobromine compound molecule to form a bromine compound in an active state, and the active bromine compound has a property of penetrating into a viscous substance secreted by algae. The algicidal effect is also exerted on algae covered with such a viscous substance. Of course, it has the same or better algicidal action on algae that are not covered with organic matter.

[0023]

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these examples.

[Organic nitrobromine compound used in Examples] Compound-A: 2-bromo-2-nitro-1,3-propanediol [manufactured by Boots; "Mayaside AS" (trade name)] Compound-B: 2,2-Dibromo-2-nitroethanol [manufactured by Nagase Kasei Co., Ltd.] Compound-C: 1,3-diacetoxy-2-bromo-2-
Nitropropane (Nagase Kasei Co., Ltd.)

[Algae used in Examples] As the test algae, an earth and human environment forum stock strain was used. <Algae covered with mucous substances> Dictiospherium pulcherium
sphaerium pulcellum: NIES-
453) Formidium Foveoralum
m foveolarum: NIES-32) <Algae not covered with mucous substances> Ocylatria agardi
a agardii: NIES-204) Scenedesmus Actesmus
acutus: NIES-94) <Medium composition used in Examples> 1000 mL of ion-exchanged water
The following components were dissolved and the pH was adjusted to 6 before use. _{KNO 3 1.25g KH 2 PO 4 1.25g} MgSO 4 · 7H 2 O 1.25g FeSO 4 · 7H 2 O 0.02g H 3 BO 3 2.86mg MnCl 2 · 4H 2 O 1.81mg ZnSO 4 · 7H ₂ O 0.22 mg CuSO ₄ .5H ₂ O 0.08 mg Na ₂ MoO ₄ 0.021 mg <Algal culture conditions used in the examples> 100 mL of medium is placed in a 300 mL Erlenmeyer flask, and 1 mL of the algal culture is added.
10 days at 2000C and 2000C for 10 days.
0 rpm rotation shaking culture was performed.

Example 1 Organic nitrobromine compound-A,
To 10 mL of an aqueous solution in which -B and -C were adjusted to 1% by weight,
0.1m of sodium hypochlorite with an effective chlorine concentration of 12%
L was added. In this case, the ratio of the bromine atom to the available chlorine atom is as follows: compound-A = 1: 2.4, compound-B = 1: 1.
5, Compound-C = 1: 3.4. Immediately after mixing, 1 minute,
3 minutes, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 45 minutes, 60
After a lapse of 120 minutes, a portion of each was collected, and an algicidal test was performed using these.

As the algae used in the test, the above four kinds of algae were used.

The algicidal test was carried out in 100 ml of algae medium.
After adding 1 mL of the liquid that had been pre-cultured for one day, 0.1 mL of an algicide solution was added (the bromine concentration in the test water was compound-A
= 0.5 mol ppm, compound-B = 0.8 mol ppm, compound-C = 0.35 mol ppm, and the effective chlorine concentration becomes 1.2 ppm in all cases). Hold for a minute. Thirty minutes later, 1 mL of a 1% by weight sodium sulfite solution was added to inactivate the algicide. Then, after culturing as it was for 10 days, the growth of algae was visually observed, and the algicidal effect was evaluated. That is, when the alga is not completely killed, remarkable growth of algae is observed in the culture for 10 days, and the culture solution is colored green. When completely algae is killed, there is no proliferation and no coloring. The amount of sodium hypochlorite added in the case of sodium hypochlorite alone used for comparison was 1.2 ppm. Table 1 shows the results.

[0029]

[Table 1] -; No growth observed (no coloration) +; slight growth observed (slightly colored green) ++; moderately growing (colored so as to lose transparency) +++; extremely active Proliferation (colored dark green)

Immediately after mixing the organic nitrobromine compound and sodium hypochlorite, it exhibits algicidal activity against algae that are not covered with mucilage, such as Ossilatoria agardi and Senedismus actes. It does not show algicidal activity against the algae Dictiospherium pulquerium and Formidium foveralum, which are covered with pollutants. On the other hand, as time elapses after mixing, the algae covered with the mucous substance also exhibit algicidal power. However, after 45 minutes, the algicidal activity was significantly reduced in all cases. The maximum algicidal power was as follows: the retention time was 3-5 minutes for Compound-A,
B was 10 minutes, and Compound-C was 5 minutes. In any case, the mixing time was maintained in the range of 1 to 30 minutes, and excellent algicidal activity was exhibited. Algae that are not covered with mucilage exhibit algicidal activity even immediately after mixing.

Example 2 In the same manner as in Example 1, the concentration of the mixture containing the organic nitrobromine compound and sodium hypochlorite was reduced to 1/10. That is, 0.09 mL of water and an effective chlorine concentration of 1 mL were added to 10 mL of an aqueous solution in which each of the organic nitro bromine compounds -A, -B, and -C was adjusted to 0.1% by weight.
0.01 mL of 2% sodium hypochlorite was added and reacted. After 5 minutes, 15 minutes, 30 minutes, and 60 minutes immediately after mixing, a part of each was collected, and an algicidal test was performed using the samples. And 100 mL of test solution containing algae
, An algicide solution was added in an amount of 1 mL, which was 10 times the amount of Example 1, and the amount of the added algicide was the same as in Example 1. Table 2 shows the results.

[0032]

[Table 2] -; No growth observed (no coloration) +; slight growth observed (slightly colored green) ++; moderately growing (colored so as to lose transparency) +++; extremely active Proliferation (colored dark green)

Even when the reaction was carried out at a concentration of 1/10 of that of Example 1, the maximum algicidal activity was as high as Compound-A, Compound-B and Compound-A.
C was 15 minutes, 15 minutes, and 30 minutes, respectively, which were slightly longer than those in Example 1, but all compounds exhibited excellent algicidal activity in the mixing time range of 1 to 30 minutes.

[0034]

According to the method of the present invention, a large algicidal effect can be exerted with a small amount of algicide, and not only algae not covered with a viscous substance but also a viscous substance covered with a viscous substance can be obtained. Algae can also be killed. As a result, it is possible to solve the problem of loss of aesthetic appearance due to the occurrence of algae and deterioration of water quality in each water system, and reduction in maintenance cost of reservoirs and related facilities is achieved.

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Claims (2)

(57) [Claims] 1. An α-position and / or a β-position with respect to a bromine atom.
A solution containing an organic nitro bromine compound having 1 to 3 nitro groups as substituents at the carbon atom at the position 1 is a chlorinating agent selected from sodium hypochlorite, calcium hypochlorite and chlorine dioxide. A method for killing alga in an aqueous system, comprising mixing seeds or two or more thereof, holding the mixture for 1 to 30 minutes, and then charging the mixture into an aqueous system. 2. The mixing ratio of the organic nitro bromine compound and the chlorine agent is such that the ratio of the number of bromine atoms in the organic nitro bromine compound to the number of chlorine atoms of available chlorine generated by the chlorine agent is 1: 1:
The algicidal method in a water system according to claim 1, wherein the ratio is 1 to 1:10.