JP5357440B2 - Harmful microorganism eradication agent and harmful microorganism eradication method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new extermination agent for a harmful microorganism which can overcome a conventional defect that a conventional extermination agent for a harmful microorganism containing sodium bisulfite and ammonium sulfate as active ingredients does not exhibit a sufficient fungicidal effect, and exhibits a wide range anti-microbial spectrum. <P>SOLUTION: Provided is an extermination agent for a harmful microorganism characterized by combining the first solution comprising an aqueous solution containing sodium hypochlorite with the second solution comprising an aqueous solution containing a potency-reinforcing ingredient obtained by mixing (a) at least one ammonium ion-supplying ingredient selected from ammonium sulfate and ammonium chloride with (b) at least one nitrogen-containing substance selected from ammonium bromide and 5,5-dimethylhydantoin in a (a):(b) molar ratio of 10:3 to 1:15. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention adds harmful microorganism eradication agents and eradication methods in aqueous solutions, particularly treated water such as washing water and cooling water used in the papermaking process, or white water, and causes slime generation contained therein. The present invention relates to a harmful microorganism eradicating agent for killing harmful microorganisms to suppress generation of slime and a method for eradicating harmful microorganisms using the same.

  In treated water such as washing water and cooling water used in the papermaking process, a large number of microorganisms are propagated using organic substances such as cellulose, lignin, hemicellulose, and polysaccharides derived from the raw wood as nutrients, These adhere to the wall of the pipeline or pit to form slime. And since this slime causes a piece of paper or a spot on the paper, it causes a reduction in production efficiency and product quality.

In order to prevent such slime failure, many slime control agents and slime control methods using the same have been proposed.
For example, a slime control agent containing hypochlorous acid or a hypobromite generating compound as an active ingredient is added to pulp slurry or white water so that the oxidation-reduction potential at 30 ° C. maintains a specific reference value. Slime control method (see Patent Document 1), cooling water system operating method in which 1 mol of hypochlorous acid or a salt thereof and 1 to 2 mol of hydantoin or a derivative thereof are mixed in advance and added to cooling water containing ammonium ions (patent) Reference 2), 0.1 to 2.0% diluted sodium hypochlorite or calcium hypochlorite in terms of chlorine concentration, and 0.1 to 6.0% diluted amine source The liquid is weighed synchronously and supplied into the pipeline, and continuously mixed in the pipeline at a predetermined ratio to produce a biocidal active ingredient on the spot, while in the liquid to be treated. What A method for suppressing the growth of microorganisms in a continuously injected liquid (see Patent Document 3), a biofilm formation inhibitor in a circulating water system obtained by mixing liquid or slurry hydantoin bromide and ammonium sulfate in water (Refer to Patent Document 4), sodium hypochlorite diluted water and an inorganic bromine compound or 5,5-dimethylhydantoin are mixed to produce a slime control agent, which is added to the water to be treated within 10 seconds. A method for adding a control agent (see Patent Document 5), a method for killing microorganisms in which ammonium sulfate is mixed with a mixture of bromochlorodimethylhydantoin and a water-soluble cellulose derivative, and immediately added to water to be treated (see Patent Document 6) ), Bromochlorodimethylhydantoin and polysaccharide polymer mixed with ammonium sulfate Was immediately and killing methods of microorganisms added to the water to be treated (see Patent Document 7) has been proposed.

By the way, as a component of these slime control agents, there is a combination of sodium hypochlorite as an oxidizing agent and a hydantoin compound as an amine component as described above, and a combination of sodium hypochlorite and ammonium sulfate. Although known (see Patent Document 8), a combination of hydantoin compounds is effective against fungi but has no effect on bacteria, and a combination of ammonium sulfate is not effective against bacteria. Although it is effective against the fungi, it is not effective against molds, so none of them is satisfactory as a slime control agent.
However, when the hydantoin compound is not used as the amine component, the antibacterial power and the antibacterial power are reduced and the antibacterial spectrum is inevitably narrow as compared with the case where it is used.

JP 2000-259933 A JP 2001-286870 A Special table 10-506835 JP 2006-232687 A JP 2007-105579 A JP 2007-319847 A JP 2007-31850 A JP 2008-43836 A

  The present invention overcomes the disadvantage that conventional microbial eradication agents containing sodium hypochlorite and ammonium sulfate as active ingredients do not exhibit a sufficient antifungal effect, and a novel toxic eradication agent that exhibits a broad antibacterial spectrum And a method for eliminating harmful microorganisms using the same.

  The present inventors have conducted various studies on methods for increasing the efficacy of harmful microorganism eradicating agents in which an aqueous solution of sodium hypochlorite is used as the first solution and an aqueous solution of ammonium sulfate as the second solution. Addition of ammonium bromide or 5,5-dimethylhydantoin (hereinafter abbreviated as DMH) as a value improver at a specific ratio can improve the eradication action against bacteria (bacteria) and molds (fungi). In addition, the inventors have found that the antibacterial spectrum range can be expanded, and that this effect is similarly exhibited when ammonium chloride is used instead of ammonium sulfate, and the present invention has been made based on this finding.

  That is, the present invention relates to a first liquid consisting of an aqueous solution containing sodium hypochlorite and (a) ammonium sulfate, (b) ammonium bromide and 5,5-dimethylhydantoin (ammonium bromide: 5,5-dimethylhydantoin = 2: 1 to 1: 5 molar ratio), and an aqueous solution containing an efficacy enhancing ingredient mixed so that the molar ratio of (a) and (b) is in the ratio of 10: 3 to 1:15. A first liquid consisting of an aqueous solution containing sodium hypochlorite and a harmful microorganism eradicating agent characterized by combining two liquids; (a) ammonium sulfate, (b) ammonium bromide and 5,5-dimethylhydantoin (odor) (Molar ratio of ammonium fluoride: 5,5-dimethylhydantoin = 2: 1 to 1: 5) so that the molar ratio of (a) to (b) is 10: 3 to 1:15. The second liquid composed of the aqueous solution containing the effect-enhancing ingredient is a 1: 1 to 1 molar ratio of hypochlorite ion in the first liquid and ammonium ion derived from the component (a) in the second liquid. The present invention provides a method for eradicating harmful microorganisms in water, characterized by adding the mixed solution to the water to be treated within 10 seconds after mixing at a ratio falling within a range of 1: 2, and mixing.

The harmful microorganism eradicating agent of the present invention comprises a first liquid for supplying free chlorine and a second liquid for reacting with free chlorine to form a microbial eradicating agent component.
When an ammonium ion source such as ammonium sulfate or ammonium chloride is present in water, chloramine is produced when it reacts with free chlorine, showing a strong eradication effect on microorganisms.

  In the present invention, an aqueous solution of sodium hypochlorite showing a role as a free chlorine supply agent is used as a first solution, and it becomes a supply source of ammonium ions that react with free chlorine to produce chloramine having an action of eradicating harmful microorganisms. An aqueous solution of ammonium salt is used as the second liquid.

  This second liquid contains at least one of ammonium sulfate and ammonium chloride as a source of ammonium ions as component (a), and ammonium bromide for promoting the reaction between ammonium ions and free chlorine as component (b). Or DMH is included. The ammonium bromide added as the component (b) is for accelerating the production of chloramine and does not serve as an ammonium ion supply source.

  Since sodium hypochlorite (NaOCl) used as the first liquid of the present invention is generally marketed as a 10 to 20% by mass aqueous solution, it is used after being diluted to a predetermined concentration with industrial water or tap water. Is advantageous. In this case, in view of reactivity with ammonium sulfate or ammonium chloride used as the component (a) of the second liquid or ammonium bromide or DMH used as the component (b) and ease of control thereof, 0.5 to 0 is considered. It is better to dilute to about 05%.

  Next, the 2nd liquid of this invention contains (a) component and (b) component. As the component (a), at least one of ammonium sulfate and ammonium chloride is an essential component, but it is advantageous to use ammonium sulfate alone from the viewpoint of availability and stability. It is advantageous in terms of ease of handling that the component (a) is usually used in the form of an aqueous solution for preparing the second liquid. As the concentration at this time, in view of handling in the case of mixing with the component (b), a relatively high concentration, for example, about 13 to 42% by mass, preferably 15 to 20% by mass is selected. By doing in this way, the addition efficiency at the time of addition can be raised.

  In addition, as the component (b) used in combination with the component (a) in the second liquid, ammonium bromide and / or DMH are used. The ammonium bromide has a bactericidal effect on water to be treated having a relatively high organic component concentration. Used when strengthening. This is usually mixed as an aqueous solution in the same manner as the component (a).

  DMH is mainly used for improving the fungicidal effect. For the purpose of improving the eradication effect against bacteria and molds and expanding the antibacterial spectrum, ammonium bromide and DMH are used in combination. In this case, it is preferable to use DMH in a ratio of 0.3 to 15 mol with respect to 1 mol of ammonium bromide. If the mixing ratio of DMH is smaller than this, the improvement effect on fungi, in particular, cannot be improved, and the expansion of the antibacterial spectrum is not recognized, and the meaning of adding DMH is lost. A particularly preferred mixing ratio is in the range of 0.5 to 1 mol of DMH with respect to 1 mol of ammonium bromide.

  The mixing ratio of the component (a) and the component (b) in the second liquid is a molar ratio of (a) :( b) of 4: 1 to 1: 2, and a mass ratio of 6: 1 to 5:11. It is a range. If it deviates from this range, the effect of inhibiting the generation of harmful microorganisms is reduced. The most preferred mixing ratio is in the range of 2: 1 to 1: 1 by molar ratio of (a) :( b) and 3: 1 to 1.4: 1 by weight.

In order to eradicate harmful microorganisms in the water to be treated using the harmful microorganism eradication agent of the present invention, the first liquid and the second liquid are mixed with hypochlorite ions (OCl ⁻¹ ) in the first liquid. After mixing at a molar ratio of ammonium ions (NH ⁴⁺ ) in the two liquids of 1: 2 to 2: 1, the mixture is added to the water to be treated within 10 seconds and mixed thoroughly.

  In this case, the first liquid and the second liquid are usually mixed as an aqueous solution having substantially the same concentration. If desired, one of the first liquid and the second liquid is a high-concentration aqueous solution, and the other is a dilute aqueous solution. As described above, a high-concentration aqueous solution can be poured into a dilute aqueous solution at the time of mixing to obtain a mixed solution containing a first liquid and a second liquid having a required concentration.

  In addition, the mixing of the component (a) and the component (b) of the second liquid may be performed by preparing respective aqueous solutions separately, and mixing the aqueous solutions, or the components (a) and (b). And may be dissolved in water to form one aqueous solution. In addition, mixing with the first liquid is usually performed by adding an aqueous solution prepared by previously dissolving the component (a) and the component (b) together to the first liquid, and mixing the component (a) And the component (b) can be prepared as separate aqueous solutions, and these two aqueous solutions can be added to the first solution and mixed.

  The use ratio of the second liquid to the first liquid in the harmful microorganism eradication agent of the present invention is preferably in the range of 1: 1 to 1: 2. If it deviates from this range, the harmful microorganism generation suppressing effect and the bactericidal effect are lowered.

  In the method of the present invention, a more effective harmful microorganism eradication effect can be obtained by adding a harmful microorganism eradicating agent to the water to be treated so that the potential due to the oxidation-reduction potential is in the range of 200 to 400 mV. For example, when the water to be treated is white water, a redox potential measuring device is installed in the inlet during the paper making process, and the harmful microorganism eradication agent of the present invention is added to the white water pit, the seed box, or both, and the inlet after the addition The oxidation-reduction potential in is measured, and it is confirmed whether or not the potential is in the range of 200 to 400 mV. In view of cost, bactericidal effect, workability, and environment, the addition of the harmful microorganism eradicating agent is preferably so-called intermittent addition in which a specific amount is added every certain time. In the case of intermittent addition, based on the measurement result of the oxidation-reduction potential measuring device, the amount of the harmful microorganism eradicating agent added next time can be adjusted to obtain a certain effect.

Examples of water to be treated that can be treated by the method of the present invention include industrial water, industrial cooling water, various papermaking process water, and white water generated in the papermaking process.
For white water, pulp fibers such as recycled pulp and virgin pulp, fillers such as calcium carbonate, white carbon and talc, sulfuric acid bands, sizing agents, paper strength agents, retention agents, and coagulants are added to paper making aids. , Mixed and stirred.

  According to the present invention, excellent bactericidal properties regardless of the type of bacteria or fungi without changing the total ammonium ion concentration of amine sources such as ammonium sulfate and ammonium bromide used in conventional sterilization methods Therefore, generation of slime can be efficiently suppressed in the treated water system. For example, in the papermaking process, it is possible to prevent the occurrence of a piece of paper or papermaking spots, and to achieve excellent effects such as productivity improvement and quality stabilization.

  Next, the best mode for carrying out the present invention will be described by way of examples.

Reference example 1
Using ammonium sulfate as the component (a) and ammonium bromide as the component (b), second liquid samples A to E each comprising an aqueous solution containing the concentrations shown in Table 1 were prepared. The substitution rate in the table represents the percentage when (a) a part of the added amount of ammonium sulfate is considered to be substituted with (b) ammonium bromide, and expressed as a percentage. )-(B)] / (a)] × 100.

Reference example 2
Using ammonium sulfate as the component (a) and DMH as the component (b), second liquid samples F to I each comprising an aqueous solution containing the concentrations shown in Table 2 were prepared. The substitution rate in the table is the percentage when (a) a part of the added amount of ammonium sulfate is considered to be substituted with (b) DMH, and is represented by the formula [[(a)- (B)] / (a)] × 100.

Reference example 3
Second liquid samples J to V comprising aqueous solutions containing different mixing ratios shown in Table 3 were prepared using ammonium sulfate as the component (a) and a mixture of ammonium bromide and DMH as the component (b). The substitution rate in the table is the percentage when (a) a part of the addition amount of ammonium sulfate is considered to be substituted with ammonium bromide or DMH, respectively, and the addition amount of ammonium sulfate is (A) When the amount of ammonium bromide or DMH added was (b), each of ammonium bromide or DMH was determined by the formula [[(a)-(b)] / (a)] × 100. It is a numerical value.

Using a circulating humidity controller, 100 ml of white water [bacterial count (CFU) 1.4 × 10 ⁷ , fungal count 14] collected from the A-coated coated paper machine is heated to 37 ° C.
Separately, a 14% by mass sodium hypochlorite aqueous solution was added to industrial water maintained at 5 ° C., and a diluted sodium hypochlorite aqueous solution having a concentration of 0.04 mol / liter in terms of the amount of active chlorine was prepared. The first liquid is used.
To 100 ml of this first liquid, the second liquid obtained in Reference Examples 1 and 2 was added so as to be equimolar in terms of ammonium ion and mixed. After 5 seconds, 0.00003 in terms of ammonium ion concentration in the above white water. Add in amounts to give mol / liter, 0.00006 mol / liter or 0.00012 mol / liter and mix well.
After 5 minutes, a portion of white water was collected and subjected to pour plate culture by a conventional method, and the number of microorganisms in white water was counted from the number of colonies generated. A standard agar medium was used as a bacterial culture medium, and a PDA medium supplemented with streptomycin was used as a fungal culture medium.
The results are shown in Table 4.

  As can be seen from this table, by using a mixture of (a) ammonium sulfate and (b) ammonium bromide or DMH as the second liquid, bacteria and fungi in white water with an active ingredient concentration of about 0.00006 mol / liter Excellent bactericidal effect on varieties.

Using white water [bacterial count (CFU) 6.8 × 10 ⁷ , fungal count 188] collected from the B factory newspaper paper machine, it was treated in the same manner as in Example 1. The results are shown in Table 5.

  As can be seen from this table, by using (a) ammonium sulfate and (b) ammonium bromide or DMH as the second liquid, it is possible to prevent bacteria and fungi in white water at an active ingredient concentration of about 0.00012 mol / liter. Excellent bactericidal effect.

Using white water [bacterial count (CFU) 2.8 × 10 ⁹ , fungal count 1056] collected from the paperboard machine of factory C, the same treatment as in Example 1 was performed. The results are shown in Table 6.

  As can be seen from this table, when two components are used as component (b) of the second liquid, the mixing ratio of ammonium bromide and DMH can be selected from a range of 2: 1 to 1: 5 by molar ratio. Pesticide with antibacterial spectrum is obtained.

  The harmful microorganism eradication agent of the present invention and the harmful microorganism eradication method using the same have a high bactericidal effect on bacteria and fungi, so that the occurrence of slime trouble can be suppressed, and as a result, high-quality paper can be obtained. And can be used very effectively in the manufacture of paper.

Claims (3)

A first solution comprising an aqueous solution containing sodium hypochlorite and (a) ammonium sulfate ;
(B) ammonium bromide and 5,5-dimethylhydantoin (ammonium bromide: 5,5-dimethylhydantoin = 2: 1 to 1: 5 molar ratio)
Eradication of harmful microorganisms characterized by combining a second solution comprising an aqueous solution containing an efficacy enhancing ingredient mixed so that the molar ratio of (a) and (b) is 10: 3 to 1:15 Agent.   The harmful microorganism eradication agent according to claim 1, wherein in the combination of the first liquid and the second liquid, the concentration of ammonium ions derived from the component (a) is adjusted within a range of 2 to 4 mol per liter. A first liquid comprising sodium-containing aqueous solution of hypochlorous acid, (a) ammonium sulfate and (b) ammonium bromide and 5,5-dimethylhydantoin (ammonium bromide: 5,5-dimethylhydantoin = 2: 1 A second liquid comprising an aqueous solution containing a potentiating ingredient mixed such that the molar ratio of (a) and (b) is in the ratio of 10: 3 to 1:15. After mixing at a ratio such that the molar ratio of hypochlorite ion in the first liquid and ammonium ion derived from the component (a) in the second liquid is in the range of 1: 1 to 1: 2, 10 seconds. A method for eradicating harmful microorganisms in water, wherein the mixed solution is added to the water to be treated within and mixed.