KR20140138669A - Method for controlling microorganisms in aqueous system - Google Patents

Abstract

Disclosure of the Invention An object of the present invention is to provide a method for effectively inhibiting microbes in aquatic environments.
A method for inhibiting microorganisms in aquatic organisms is a method comprising using a chlorine-based oxidizing agent, a combination of sulfamic acid or a salt thereof, a drug comprising chlorosulfamic acid or a salt thereof, and an inorganic or organic slime control agent in combination. This method preferably includes a step of adding a drug to the slurry control agent simultaneously with or before the addition of the slime control agent. For example, a step of adding a medicine and a slime control agent to a place where a slime failure is detected.

Description

[0001] METHOD FOR CONTROLLING MICROORGANISMS IN AQUEOUS SYSTEM [0002]

The present invention relates to a microorganism suppressing method (microorganism suppressing method) of an aqueous system.

A slime composed of bacteria, mold bacteria, seaweed, etc. is generated in the system in plant cooling water system of plant, paper pulp water system, wastewater treatment water system, steel water system and cutting water system of various factories, (Blockage) of the water supply pipe, corrosion of the piping metal material, and the like.

Therefore, a drug for avoiding such slime disorder has been developed. Patent Document 1 discloses a slime releasing agent comprising a combination of a chlorine-based oxidizing agent and a sulfamic acid or a salt thereof. Patent Document 2 discloses a slime releasing agent comprising ammonium bromide and phosphoric acid A medicament comprising a reaction product of sodium hypochlorite is disclosed.

Patent Document 1: JP-A-2003-267811 Patent Document 2: Japanese Patent No. 3497171 Disclosure of Invention

However, there is a demand for a microorganism suppressing technique that is superior to conventional drugs. For example, the slime removing agent shown in Patent Document 1 is excellent in the function of cleaning the surface of a facility by peeling the slime, but the sterilizing effect is insufficient. Further, in the medicine shown in Patent Document 2, once the slime is formed, sufficient sterilization can not be performed in some cases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method capable of efficiently suppressing microbes in aquatic environments.

(1) a medicament comprising a chlorine-based oxidizing agent and a combination of sulfamic acid or a salt thereof, or chlorosulfamic acid or a salt thereof,

A method for inhibiting microorganisms in an aqueous system using an inorganic or organic slime control agent in combination.

(2) The method according to (1), wherein the step of adding the agent is carried out simultaneously with or before the addition of the slime control agent.

(3) A method according to (1) or (2), wherein the step of adding the agent and the slime control agent to a site where a slime failure is detected.

(4) The method according to any one of (1) to (3), further comprising the step of adding the above-mentioned medicament to the pulp storing part and adding the slime controlling agent to the paper making system in the water system of the paper making facility.

According to the present invention, by using a combination of a chlorine-based oxidizing agent, sulfamic acid or a salt thereof, a chlorosulfamic acid or a salt thereof, and an inorganic or organic slime control agent, aqueous organisms can be effectively inhibited.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

The method for suppressing microorganisms in an aqueous system according to the present invention is to efficiently suppress aqueous organisms by using a predetermined pharmaceutical agent and a slime control agent in combination.

The slime control agent may be inorganic or organic, and inhibits microorganisms in the aqueous system by exhibiting a sterilizing action (bactericidal action). The slime control agent having the above function is conventionally known and can be widely used. As the inorganic or organic slime control agent, either one of them may be used, or both of them may be used.

The inorganic slime control agent includes, but is not limited to, chloramine, bromamine, a reaction product of ammonium bromide and sodium hypochlorite, a reaction product of ammonium sulfate and hypochlorite, Bromosulfamic acid and the like may be used alone or in combination. A reaction product of ammonium bromide and sodium hypochlorite is disclosed in Patent Document 2.

Organic slime control agents include, but are not limited to, 2,2-dibromo-3-nitrilopropionamide (DBNPA), 2,2-dibromo-2 2-nitro-1,3-propanediol (BNP (2-bromo-2-nitro- ), Orthophthalaldehyde (OPA), glutaraldehyde, 4,5-dichloro-1,2-dithiolan-3-one (dithiol) bis (bromoacetoxy) -2-butene, 1,2-bis (bromoacetyl) -2-butene, 2-methyl-4-isothiazoline-3-one or its metal salt, 5-chloro-2 Methyl-4-isothiazoline-3-one or its metal salt, 4,5-dichloro-2-octyl-4-isothiazoline-3-one 4,5-dichloro-2-octyl-4-isothiazoline-3-one, 1,2-benzoisothiazoline-3-one, methylenebisthiocyanate, hexabromodimethylsulfone, 3,3,4,4-tetrachlorotetrahydrothiophene, Dichloro-3-chloro-5,5-dimethylhydantoin (1, -bromo-3-chloro-5,5-dimethylhydantoin, tetrakis-hydroxymethyl-phosphonium-sulfate, and the like.

The inventors of the present invention have focused on the fact that inorganic or organic slime control agents are excellent in bactericidal action, but can not sufficiently sterilize microorganisms in the slime once a slime (microbial flock) is formed. In the present invention, a predetermined medicament is used together with a slime control agent.

The medicament used in the present invention is composed of a chlorine-based oxidizing agent and a combination of sulfamic acid or a salt thereof, or chlorosulfamic acid or a salt thereof. They have an excellent function of inhibiting the formation of slime and decomposing an adhesive component (adhesive component) surrounding the microorganisms in the slime, even if a slime is formed. As a result, it is presumed that the slime control agent used in combination is not inhibited by the adhesive component so that microorganisms can be easily sterilized, thereby improving the efficiency of microbial inhibition. The combination and the chlorosulfamic acid may be either one or both of them.

The chlorine-based oxidizing agent and the combination of sulfamic acid or a salt thereof may be those disclosed in Patent Document 1. Specifically, the chlorine-based oxidizing agent is not particularly limited as long as it is a chlorine-based oxidizing agent and is preferably hypochlorous acid or its salt, more preferably sodium hypochlorite, from the viewpoints of cost, handling, safety, solubility in water and the like. As the sodium hypochlorite, 12% sodium hypochlorite which is generally circulated can be used.

The sulfamic acid or its salt is not particularly limited, and examples thereof include sulfamic acid and ammonium sulfamate. Sulfamic acid, like hydrazine, is not poisonous but highly safe.

The content ratio of the effective chlorine, the sulfamic acid and the salt thereof in the chlorine-based oxidizing agent is 2: 1 to 1: 5, preferably 2: 1 to 2: 1, in terms of molar ratio (effective chlorine of the chlorine- : 1 to 1: 2. The effective chlorine of the chlorine-based oxidizing agent is chlorine measured by a residual chlorine measuring method according to JIS K0101.

It is preferable that the combination includes alkali such as sodium hydroxide or potassium hydroxide from the viewpoint of further improving the storage stability.

The chlorosulfamic acid or its salt is not particularly limited, and it may be at least one of N-chlorosulfamic acid, N, N-dichlorosulfamic acid, and at least one salt thereof.

It is preferable that the addition of the agent from the above function of the drug and the slime control agent is carried out at the same time as or before the addition of the slime control agent. As a result, the inhibition of the slime formation or the decomposition of the adhesive substance is preceded, so that the sterilizing action of the slime control agent is likely to be exhibited quickly. However, the addition of the agent may be later than the addition of the slime control agent.

The addition, before, after, and after addition is not limited to the temporal but includes the place. For example, the addition of the drug before the addition of the slime control means that the addition of the slime control agent is started (time-wise) after the start of the addition of the drug, The upper (local) sun is also included.

The place of addition of the drug and the slime control agent is not particularly limited. However, the method of the present invention preferably includes a step of adding a drug and a slime control agent to a site where slime failure is detected. Thus, the slime failure can be eliminated directly or efficiently. In the conventional method, even if a preparation is added to the place where the slime failure occurs, it is difficult to effectively remove the obstruction by being inhibited by the slime, but in the present invention, it is possible to effectively remove the obstacle. In addition, the detection of the slime failure may be performed according to a normal method.

It is preferable that a slime control agent is added to a place where slime disturbance is likely to occur by adding a medicine at a place where slime disturbance is likely to occur or at a position where the slime disturbance is likely to occur. Thus, slime failure can be effectively prevented.

It is also preferable that the method of the present invention includes a step of adding a medicament to a pulp reservoir and adding a slime control agent to a paper making system in the aqueous system of a paper making facility Do. The pulp reservoir is liable to form a slime in a nutritive state, but the addition of a drug to the pulp reservoir inhibits slime formation, thereby reducing the inflow of the slime to its downstream (including grass). As a result, the slime control agent of the grass-based system can effectively function to inhibit microorganisms. In addition, the place of adding the medicine and the slime control agent in the water system of the paper making facility is not limited to this.

The amount of the pharmaceutical agent and the slime control agent to be added is not particularly limited, and it may be 0.2 to 500 mg / L each. The ratio of the addition amount of the drug to the slime control agent is not particularly limited, and it may be 99/1 to 5/95 (mass ratio). Further, the addition amount may be appropriately changed depending on the circumstances such as the degree of slime failure. For example, when the degree of slime disruption increases, even if the addition amount or ratio of the slime control agent is increased, the sterilizing action is not efficiently exhibited. Therefore, the addition amount or ratio of the drug may be controlled to be increased. The ratio of the addition amount refers to the ratio of the addition amount within a certain time.

The method of adding the pharmaceutical agent and the slime control agent is not particularly limited, and may be added individually or after mixing. At least one of the agent and the slime control agent may be added continuously or intermittently. The drug and slime control agent are preferably in the form of a solution (for example, an aqueous solution) prepared beforehand from the viewpoint of quantitative properties.

The water system to which the method of the present invention is applied is not particularly limited as long as it is an aqueous system capable of causing a disruption by microorganisms. The water system is applicable to plant cooling water systems, paper pulp water systems Water system and so on.

In the method of the present invention, it is also possible to use a biocide, a growth inhibitor, a humus inhibitor, a copper anticorrosive agent, a scale inhibitor, A defoaming agent, a surfactant (surfactant), or the like may be further used.

Example

≪ Example 1 >

A tube made of vinyl chloride having an inner diameter of 3 mm was passed through a constant temperature water bath at 35 캜 and kept at a temperature of 8 mL / min. 2 g of glucose, 0.35 g of ammonium sulfate, 0.7 g of dipotassium hydrogenphosphate, 0.3 g of potassium dihydrogenphosphate and 0.05 g of magnesium sulfate heptahydrate were dissolved in 10 L of dehydrochlorinated tap water. To this solution were added 100 mL of a 0.5 M phosphate buffer solution at pH 7 and white water of a coated base paper as a microorganism was cultured in a standard medium to inoculate the cells to a bacterial count of 10 ⁶ / And used as the medium. A Y-tube was installed in the middle of the tube so that the formulation shown in Table 1 could be added, and the preparation was added in a cycle of addition for 4 hours and suspension for 4 hours.

After 7 days, the tube was taken out and cut, and the slime adhered to the length of 10 cm of the tube was wiped with a cotton swab and dispersed with 1 mL of sterilized water (sterilized water) to measure the ATP amount of the dispersion. The results are shown in Table 1. It is also known that the amount of ATP is proportional to the number of bacteria.

[Table 1]

CSA: Chlorosulfamic acid

DBNE: 2,2-dibromo-2-nitroethanol

Dithiol: 4,5-dichloro-1,2-dithiolan-3-one

OPA: orthopthalaldehyde

As shown in Table 1, in Examples 1 to 3 in which chlorosulfamic acid and a slime control agent were used in combination, the amount of ATP, that is, the number of bacteria, could be remarkably reduced despite the low total amount of addition, It was found that the inhibition of slime adhesion could be efficiently performed.

≪ Example 2 >

Methylobacterium sp., The causative agent of the pink slime separated from the pink slime on the machine that paper is used for paper making, is separated from the pink slime (a pink slime that produces pink spots when changed to paper) And cultured in a standard liquid medium at 30 캜 for 2 days to obtain a pink microbial floc. The flocs were washed with sterilized water and disrupted by a stirrer to obtain micro flocs. This micro floc was dispersed in a 1/150 M phosphate buffer solution of pH 7 to obtain a test solution. The formulation shown in Table 2 was added to the test solution, and after vibrating at 30 DEG C for 2 hours, 200 mg / L of sulfurous acid was immediately added to dissolve the preparation. Thereafter, the test solution was added to a sterilized homogenizer and treated at 10000 rpm for 3 minutes to disperse the cells. Table 2 shows the results of measurement of the number of dispersed cells by agar plate dilution method (寒 天 平板 dil釋 法).

[Table 2]

DBNPA: 2,2-dibromo-3-nitrylpropionamide

Reactant A: A mixture of an aqueous solution of ammonium bromide and an aqueous solution of sodium hypochlorite

DCG: dichloroglyoxime

As shown in Table 2, it was found that in the examples in which chlorosulfamic acid was used in combination with the slime control agent, the number of bacteria could be remarkably reduced as compared with the comparative example using only one of them, and sterilization could be efficiently performed.

≪ Example 3 >

In a machine for blending virgin pulp (LBKP) and deinked pulp (DIP) to deter painted base paper, a slime failure caused by decay of deinked pulp was remarkable. Here, the reaction product of the aqueous solution of ammonium bromide and the aqueous solution of sodium hypochlorite was added to the chest of deinked pulp 8 times / day (day) as ₂ mg / L (the amount of water retained as ₂ units of as Cl) / L (as Cl ₂ ) for 10 minutes, respectively. In this way, improvement was expected after the start of addition, but after two weeks, the slime began to adhere to the white water silo, and after 3 weeks, a spot appeared to be caused by the slime in the paper.

Next, a reaction product of the de-inked chest sulfamic acid sodium and sodium hypochlorite in the pulp 2mg / L (as Cl ₂ dae hand quantity) 4 times / day, the reaction of the bromide, ammonium and sodium hypochlorite aqueous solution propelled based 2mg / L (as Cl ₂ ) for 10 minutes, respectively. In this way, the slime production in the white silo can be inhibited for over three weeks, and the occurrence of spots on the paper is greatly reduced.

Further, even if the reaction product of sodium sulfamate and sodium hypochlorite was added 3 times / day to keep the dehydrated pulp at 2 mg / L (as ₂ units of Cl) and 5 mg / L (as Cl ₂ ) in the paper system for 30 minutes , And slime began to attach after two weeks.

Thus, it was found that a slime can be efficiently controlled by adding a combination of sodium sulfamate and sodium hypochlorite to the pulp storage section and adding a slime control agent to the paper mill in the aqueous system of the paper making plant, .

<Example 4>

BNP was continuously added to the gelatin solution after gelatinization in an amount of 20 mg / L in a system in which oxidized starch was gelatinized and applied as a surface sizing agent, And BNP was added in an amount of 50 mg / L (amount of gelatin solution to the inflow) for 2 hours, three times. However, after 5 days, the corruption proceeded, and the pH dropped from 6.5 to 5.5, and bubbling by decomposition products was started. Here, instead of BNP added to the circulation system, chlorosulfamic acid was added 3 times for 4 hours with 5 mg / L (the amount of the large amount of gelatin solution), and the pH gradually increased to recover to 6.5 after 1 day, It was resolved.

As a result, it was found that the chlorosulfamic acid and the slime control agent were used in combination to obtain an effective preservative effect even though the total amount of the addition was low. This is presumably because chlorosulfamic acid acts on the slime attached to the system to decompose the extracellular polymer (adhesive component), and as a result, the slime control agent added from the beginning acts directly on the bacteria to exert a preservative effect.

Claims (4)

A combination of a chlorine-based oxidizing agent and a sulfamic acid or a salt thereof, or a combination of a pharmaceutical agent comprising chlorosulfamic acid or a salt thereof,
An inorganic or organic slime control agent
A method for inhibiting microorganisms in a water system in combination.
The method according to claim 1,
And a step of adding the agent to the slurry control agent simultaneously with or before the addition of the slime control agent.
3. The method according to claim 1 or 2,
And adding the agent and the slime control agent to the site where the slime failure is detected.
The method according to any one of claims 1 to 3,
A method for inhibiting microorganisms in a water based system, comprising the step of adding the agent to a pulp reservoir in a water system of a paper making facility and adding the slime control agent to a paper making system.