JP2012056874A - Method of treating cooling water system and treating agent set used therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slime peeling/sterilizing method which excels in the slime peeling effect and the sterilizing effect on microorganisms, furthermore has low corrosiveness and high safety, reduces the amount of a chemical used, and has high workability in the opened circulation water cooling system.SOLUTION: The treating method comprises incorporating a chlorine based oxidizing agent into the cooling water system in the first half of slime peeling and sterilization of microorganisms in the cooling water system and incorporating a surface active agent based drug into the cooling water system in the latter half.

Description

  The present invention relates to a treatment method that achieves both exfoliation of slime and sterilization of microorganisms in an open circulating water cooling water system, and a treatment agent set used therefor.

In an open-type circulating water cooling water system, slime composed of microorganisms such as bacteria, fungi, and algae is generated in the system and adheres to piping and heat exchangers. In addition, it may cause slime failure such as local corrosion of piping and heat exchangers. In addition, the slime becomes a hotbed of Legionella spp. That have intracellular parasitism, and it also causes effects on the human body such as Legionella infection.
As a countermeasure against such slime failure, a slime peeling treatment and a sterilization treatment with a drug are performed. Conventionally known chemical agents include chlorine-based oxidizing agents such as sodium hypochlorite, hydrazine, and hydrogen peroxide.

The treatment with sodium hypochlorite has a wide sterilization spectrum range and a high sterilization effect against microbial groups such as bacteria, fungi and algae, but a low dispersion effect and a low slime peeling effect. In addition, when added at a high concentration, there is a problem that corrosion of metal materials such as piping occurs.
The treatment with hydrazine has a high dispersion effect and a high slime peeling effect, but a low bactericidal effect on microbial groups such as bacteria, fungi and algae. In addition, it is a carcinogen and is highly toxic to the human body.

In the treatment with hydrogen peroxide, the slime peeling effect by foaming is high, but the amount of chemicals required for obtaining the slime peeling effect is large, and there are problems such as an increase in chemical cost and deterioration in workability. In addition, since the waste liquid needs to be neutralized, the chemical cost further increases.
Only sterilization treatment of microbial groups such as bacteria, fungi, and algae, or only slime exfoliation treatment easily proliferates microbial groups after the treatment, forms slime again, and does not solve the slime disorder.

  Under such circumstances, a technique using two or more types of bactericides and slime removers is also known. Patent Document 1 discloses a slime peel method using a chlorine-based oxidizing agent and sulfamic acid in Patent Document 2. Is a sterilization and slime killing method using a combination of a free halogen-generating biocide such as hypochlorite and a mixture of a halogen stabilizer (such as hydantoin) such as an N-hydrogen compound and a quaternary ammonium biocide. However, Patent Document 3 describes a slime peeling treatment method in which hydrazine is used in the former stage and hypochlorite or hypobromite is used in the latter stage.

JP 2003-267811 A JP-T-2004-531579 gazette JP 2004-12042 A

Combining a chemical known as a disinfectant or slime remover has advantages compared to the case where it is used alone, but both a slime exfoliation effect and a microbial disinfectant effect that are sufficiently satisfactory can still be obtained. Not.
The present invention solves the above-mentioned conventional problems in an open-type circulating water cooling water system, is excellent in slime peeling effect and microbial sterilization effect, and has low corrosiveness, high safety, and chemical use amount It is an object of the present invention to provide a slime peeling and sterilizing method with little workability and high workability, and a drug used therefor.

This invention solves the said subject, and has the structure of following (1)-(6).
(1) A cooling water system slime peeling and microbial sterilization, wherein a chlorine-based oxidizing agent is contained in the cooling water system in the first stage, and a surfactant-based agent is contained in the cooling water system in the second stage.
(2) The addition amount of the former chlorinated oxidant is 0.1 to 1000 mg / L as effective chlorine, and the addition amount of the latter surfactant agent is 1 to 1000 mg / L as the component concentration. The processing method according to (1) above.
(3) The processing method according to (1) or (2) above, wherein the surfactant in the subsequent stage is added 0.1 to 3 hours after the addition of the chlorinated oxidizing agent in the preceding stage.
(4) The processing method according to any one of (1) to (3), wherein the temperature in the cooling water system is processed at 5 to 70 ° C.
(5) The treatment method according to any one of (1) to (4) above, wherein an acid or an alkali agent is added and the pH in the cooling water system is treated at 5 to 12.
(6) A cooling water treatment agent set for use in the treatment method according to any one of (1) to (5) above, which is a combination of a chlorine-based oxidizing agent-containing agent and a surfactant-based agent-containing agent.

  According to the present invention, a cooling water-based slime is treated with a chlorine-based oxidant in the former stage and a surfactant-based agent in the latter stage, so that a synergistic effect between the two results in an excellent slime peeling effect. In addition, it has been found that a sterilizing effect on microorganisms can be obtained, and further provides a treatment method and a treatment agent set with low metal corrosiveness, low human influence and environmental load, low chemical use, and high workability. can do.

It is a schematic diagram of the cooling water system for enforcing the processing method of the present invention.

  In the treatment method of the present invention, in an open-type circulating water type cooling water system, the cooling water contains a chlorine-based oxidizing agent in the former stage and a surfactant-based agent in the latter stage, so that the slime removal and the microorganism sterilization of the cooling water system are performed. Is to do. Here, the “front stage” is a front stage (first half) of the cooling water system peeling process, and a “back stage” is a rear stage (second half) of the peeling process.

In the treatment method of the present invention, the combination of the chlorine-based oxidant and the surfactant-based agent does not mean that both are mixed and used, and the surfactant is applied after the chlorine-based oxidant is applied to the cooling water system. This is a combination of applying a series of chemicals, whereby a synergistic effect between the chlorine-based oxidizing agent and the surfactant-based chemicals is exhibited, and both an excellent slime peeling effect and a bactericidal effect are achieved.
Even if a chlorine-based oxidizing agent and a surfactant-based agent are contained at the same time, sufficient compatibility between the slime peeling effect and the bactericidal effect cannot be obtained. This is presumably because the chlorine-based oxidizing agent and the surfactant-based agent react to consume effective chlorine, and the slime peeling effect and the microbial disinfection effect are reduced. Moreover, even if a surfactant-based agent is contained in the former stage and a chlorine-based oxidizing agent is contained in the latter stage, a sufficient slime peeling effect cannot be obtained. A slime is an aggregate of microorganisms, and its surface layer is covered with an adhesive polymer to protect the microorganism layer forming the slime. For this reason, in normal drug treatment, the drug does not come into contact with the microbial layer, and it is difficult to peel and sterilize the slime. In the method of the present invention, by adding a high-concentration chlorine-based disinfectant in the previous stage, the adhesive polymer in the surface layer is decomposed, and the surfactant-based drug added in the subsequent stage is easily brought into contact with the microorganism layer, thereby achieving an effect. It is estimated that the slime can be peeled and sterilized.

  As described above, the combination of the chlorine-based oxidizing agent and the surfactant-based agent in the slime peeling treatment agent of the present invention does not mean that both are used in combination, and the chlorine-based oxidizing agent is applied to the cooling water system. After that, the combination is premised on the usage method of applying a surfactant-based drug. In the present invention, after adding the former chlorinated oxidant and being effectively applied in the cooling water system, the latter surfactant is added, and the addition time between the former and the latter is particularly Although it is not limited, it is preferable that the surfactant in the subsequent stage is added during 0.1 to 3 hours, more preferably 0.1 to 1 hour, so that the slime and microorganisms in the cooling water system can be removed. It can be stripped and sterilized more easily and more efficiently. Although it depends on the system to be applied, when it is added after 3 hours or more, the slime peeling effect and the microorganism sterilizing effect are hardly obtained, which is not preferable.

  In the present invention, after the surfactant agent is contained in the cooling water system in the subsequent stage, the cooling water system is circulated through the cooling water system for 0.1 hour or more to easily and efficiently sterilize the microorganism group such as Legionella spp. In the cooling water system. be able to. The bactericidal action is also exerted on amoeba and slime serving as a hotbed of Legionella spp., And as a result, the exfoliating action of the slime is promoted. The circulation time after the surfactant-based agent is applied in the latter stage is preferably 0.1 hour or more for obtaining the sterilizing effect of microorganisms and 1 hour or more for obtaining the slime peeling effect. In the case of less than 0.1 hour, the sterilizing effect of microorganisms decreases depending on the pH and temperature. The upper limit of the circulation time is determined by various circumstances and is not particularly limited, but is usually about 10 hours, preferably 6 hours, from the viewpoint of workability. The longer the circulation time, the higher the metal corrosivity.

  The chlorinated oxidant to be contained in the cooling water system in the previous stage is not particularly limited as long as it is a chlorinated oxidant. For example, hypochlorous acid which is chlorous acid or a salt thereof and is an inorganic chlorinated compound. Examples thereof include sodium, potassium hypochlorite and chlorinated isocyanuric acid which is an organic chlorine-based compound. Among them, sodium hypochlorite is preferable. The addition amount is 0.1 to 1000 mg / L, preferably 10 to 200 mg / L as effective chlorine. When the added amount is 0.1 mg / L or more as effective chlorine, a sufficient slime peeling effect and microbial bactericidal effect can be obtained. Moreover, at 1000 mg / L or less, the influence of corrosion on metal materials such as pipes and heat exchangers can be suppressed to a low level.

  Examples of the surfactant-based agent to be contained in the cooling water system in the subsequent stage include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant, but are not particularly limited.

  As an anionic surfactant, higher fatty acid salt, olive oil sulfate ester salt, alkyl sodium sulfate, sodium alkylbenzene sulfonate, sodium α-olefin sulfonate, sodium N-acylamino acid, N- (2-sulfo) ethyl-N-methyl Examples include alkaneamide sodium, 2-sulfosuccinic acid dialkylamide, sodium alkylnaphthalenesulfonate, and carboxylic acid polymers. Examples of the carboxylic acid-based polymer include (meth) acrylic acid, (meth) acrylic acid ester, styrene, α-olefin, (meth) acrylamide, maleic acid, maleic acid ester, itaconic acid, and other homopolymers or copolymers. It is done.

Examples of the cationic surfactant include alkyltrimethylammonium halide, alkylpyridinium sulfate, N-ethylalkanamide ammonium halide and the like.
Nonionic surfactants include alkyl polyoxyethylene ether, p-alkylphenyl polyoxyethylene ether, fatty acid polyhydric alcohol ester, fatty acid polyhydric alcohol polyoxyethylene, fatty acid polyoxyethylene ester, fatty acid sucrose ester, amphoteric interface Examples of the activator include alkylbetaines and alkyldiethylenetriaminoacetic acids.

Among the above, a cationic surfactant is preferable, and a quaternary ammonium salt is particularly preferable. Further, as the quaternary ammonium salt (NR ¹ R ² R ³ R ⁴ X), the four substituents (R ^{1 to} R ⁴ ) are linear, branched or cyclic substituted or unsubstituted alkyl groups, alkenyls Or a benzyl group, wherein at least one substituent (R ¹ ) is an alkyl group having a total carbon number of 8 to 18, and the remaining substituents (R ² , R ³ , R ⁴ ) have a total carbon number More preferably, it is a chloride or bromide (X = Cl or Br) which is an alkyl group of 1 to 8 each. Further preferred quaternary ammonium salts are those in which R ¹ is a linear unsubstituted alkyl group having 12 carbon atoms in total, R ² is a cyclic benzyl group having 7 carbon atoms in total, and R ³ and R ⁴ are It is a chloride (X = Cl) which is an alkyl group having a total carbon number of 1.

  The addition amount of the surfactant-based agent is 1 to 1000 mg / L, preferably 1 to 100 mg / L as the component concentration. When the addition amount is 1 mg / L or more as the component concentration, a sufficient slime peeling effect can be obtained. At 1000 mg / L or less, a sufficient slime peeling effect can be obtained, foamability can be suppressed, and processing can be performed without any problem.

  Further, by treating the temperature in the cooling water system preferably at 5 to 70 ° C., more preferably 40 to 70 ° C., the slime and microorganisms in the cooling water system can be peeled and sterilized more easily and efficiently. If the temperature is lower than 5 ° C, the reactivity of the drug is low, and if it is 70 ° C or higher, the drug component is decomposed and the slime peeling effect tends to decrease, which is not preferable.

  The pH in the cooling water system is not particularly limited by adding an acid or an alkali agent. For example, when adding a surfactant-based agent in the latter stage, the pH is set to 5 to 12, and further to 7 to 10. In this range, the slime peeling effect is improved, and the slime peeling treatment and the microorganism sterilization treatment can be performed while reducing the corrosiveness. In general, when the pH is less than 5, the drug component is easily decomposed, and when it is 12 or more, the reactivity of the drug is low, and the slime peeling effect and the microbial sterilization effect tend to decrease, which is not preferable.

  The acid that can be added to the cooling water system is not particularly limited, and is preferably an inorganic acid, and examples thereof include hydrochloric acid, sulfuric acid, and nitric acid. Of these, hydrochloric acid is preferred. The alkali agent is not particularly limited and is preferably an alkali metal hydroxide, and examples thereof include sodium hydroxide and potassium hydroxide. Among them, sodium hydroxide capable of adjusting the pH with a smaller addition amount is preferable. The alkaline agent is added at the same time as or before the chlorinated oxidant in the previous stage.

  In the cooling water system, a polymer dispersant, hydrazine, glutaraldehyde, hydrogen peroxide, sulfamic acid, sodium hydrogen carbonate, a chelating agent, etc. are added to the extent that the effects of the present invention can be effectively exhibited as necessary. It can be included.

The slime peeling treatment method of the present invention will be described more specifically with reference to the drawings. FIG. 1 is a schematic view of a cooling water system for carrying out the slime peeling treatment method of the present invention.
In FIG. 1, a cooling water system 1 generally includes a cooling tower 2, a cooling water tank 6 below the cooling water tank 6, and a pump 9 and a heat exchanger in the middle for sending the cooling water 7 in the cooling water tank 6 to the cooling tower 2. And a cooling water circulation pipe 8 provided with 10. The cooling tower 2 is a type that is usually used, and is provided with a filler layer 3, a blower fan 4 installed on the top, and a water pipe 5 disposed on the filler layer 3 in the tower. ing.

  The cooling water tank 6 is provided with a processing unit 11 which is a feature of the present invention. The processing unit 11 includes a chemical tank 12 and an infusion pump 13 for supplying a pre-stage chemical (chlorine oxidant), and a post-stage chemical. It comprises a chemical tank 14 for supplying (surfactant-based chemical), an injection pump 15, and a residual halogen meter 16 for measuring the residual halogen concentration of the cooling water 7 in the cooling water tank 6. The residual halogen concentration signal measured in 16 is sent to the control device 17, and the infusion pump 13 or the infusion pump 15 is operated by the signal, and the upstream chemical (chlorine oxidant) or the downstream chemical (surfactant chemical). ) To supply.

  Examples of the present invention are shown below, but the present invention is not limited to these examples.

<Example 1, Comparative Examples 1-8 and Reference Example 1>
1000 ml of tap water was placed in a glass beaker having a capacity of 1 L, 3 ml of mixed raw sludge derived from sewage, and 1 ml of a nutrient source having the composition shown in Table 1 were stirred at 400 rpm. A SUS 0.37 × 20 mesh wire mesh carrier was immersed in this beaker and mixed and cultured at room temperature for 1 week. During the cultivation, 1 ml / day of a nutrient source was added. The wire mesh carrier to which the slime adhered was used as a test piece for cleaning and sterilization tests.

  Next, 1000 ml of test water was put into a 1 L glass beaker, the test piece was immersed, and stirred at 600 rpm. The sample water used was untreated cooling water in which Legionella was detected. Thereafter, treatment chemicals as shown in Table 2 were added in a predetermined amount and treatment time as shown in Table 2, and the slime peeling state of the test piece from immediately after the addition until 3 hours was visually observed, Turbidity and the number of general bacteria were measured as water quality items in the beaker after the test, and the slime peeling effect and the microbial bactericidal effect were evaluated.

The evaluation of slime peeling was performed by visually observing the area ratio between the slime remaining on the test piece after the test and the wire mesh carrier. The slime peeling state is 90 to 100%, ７０, 70 to 90% ○, 50 to 70% Δ to ○, 30 to 50% Δ, 0 to 30% ×, and the higher the turbidity, the more the peeling effect Was rated high. The evaluation method of the microbial bactericidal effect evaluated that the bactericidal effect was so high that the number of general bacteria was low.
Turbidity was measured with an integrating sphere turbidimeter (SEP-PT-706D, manufactured by Mitsubishi Chemical Corporation), and the number of microbial bacteria was measured using a sheet medium for general living bacteria (Sani-kun (registered trademark of Chisso Corporation)). , Manufactured by Chisso Corp.) and cultured at 35 ° C. for 48 hours and counted by counting the number of colonies.

The results of the above slime peeling / sterilization test are shown in Table 2. In addition, the chemical | medical agent addition rate of a chlorine-type oxidizing agent is shown as effective chlorine concentration, and the chemical | medical agent addition rate of another process chemical | medical agent is shown as a component concentration.
Table 2 shows the results (Example 1) of the slime peeling / sterilization test performed by the method of the present invention and the results (Comparative Examples 1-8) of the slime peeling / sterilization test using a conventionally known slime remover or fungicide. The test result when no chemical treatment is performed as a blank is shown in Comparative Example 8.

When treated with sodium hypochlorite alone, quaternary ammonium salt alone, hydrazine alone, glutaraldehyde alone and hydrogen peroxide alone (Comparative Examples 1 to 5), the slime peeling effect and bactericidal effect were low. For example, in the sodium hypochlorite single treatment (Comparative Example 1), the slime peeling effect was lowered, and in the quaternary ammonium salt single treatment (Comparative Example 2), the slime peeling effect was extremely lowered and the bactericidal effect was also low. . By adding 50 mg / L of sodium hypochlorite as a pretreatment according to the method of the present invention, and adding 50 mg / L of quaternary ammonium salt as a posttreatment after 0.5 hours, and stirring for 3 hours (Example 1), A good slime peeling effect was obtained, the number of general bacteria was 1 × 10 ² CFU / ml or less, and a good bactericidal effect was also obtained.

Furthermore, the Legionella genus count became 10 CFU / ml or less by processing by the method of this invention, and the favorable bactericidal effect with respect to Legionella genus bacteria was acquired. In the case of quaternary ammonium salt alone (Comparative Example 2), hydrazine alone (Comparative Example 3) and hydrogen peroxide alone (Comparative Example 5), the number of Legionella bacteria is 8 × 10 ² CFU / ml and 7 × 10 ² CFU, respectively. / Ml and 1 × 10 ³ CFU / ml, and the bactericidal effect against Legionella was low.

  On the other hand, when sodium hypochlorite and a quaternary ammonium salt were added simultaneously (Comparative Example 6), both the slime peeling effect and the bactericidal effect were low as compared with Example 1. When the order of addition is reversed, that is, when 50 mg / L of a quaternary ammonium salt is added as a pre-treatment, and 50 mg / L of sodium hypochlorite is added as a post-treatment after 0.5 h, and stirred for 3 h. (Comparative Example 7) Compared with Example 1, the bactericidal effect was comparable, but a sufficient slime peeling effect was not obtained.

Moreover, when the corrosion rate of mild steel was measured by the following method to evaluate the metal corrosivity, it was less than 500 mdd except when sodium hypochlorite was used alone (Comparative Example 1). There was no problem with sex.
[Measuring method for metal corrosion]
A test piece of mild steel was immersed, the test piece was taken out after the test, the weight after removing dirt and corrosion products on the surface was measured, and the corrosion rate (mdd) was calculated from the weight difference before and after the immersion (mdd) Corrosion amount (mg) of 1 dm ² surface area per day).

<Examples 2 and 3>
In Example 1, the same procedure as in Example 1 was conducted, except that the addition amounts of sodium hypochlorite as the pretreatment agent and quaternary ammonium salt as the posttreatment agent were variously changed as shown in Table 3. The slime peeling effect and the bactericidal effect were evaluated. The results are shown in Table 3. In Table 3, the metal corrosivity indicates that the corrosion rate of the mild steel is ◯ when the corrosion rate is 10 mdd or less, Δ is ◯ when the corrosion rate is 10 to 100 mdd, Δ is when the corrosion rate is 100 to 500 mdd, and × when the corrosion rate is 500 mdd or more. did.

Compared with Example 1, a better slime peeling effect was obtained by adding 200 mg / L of the sodium hypochlorite addition rate in the previous stage. Even when the treatment is reduced to 10 mg / L, the exfoliation effect and the bactericidal effect of the slime are slightly reduced, but the slime is exfoliated by about 70%, and the number of general bacteria is sufficiently 1 × 10 ² CFU / ml. Slime peeling effect and bactericidal effect were obtained. Further, when the treatment was performed with the addition rate of the quaternary ammonium salt in the subsequent stage reduced to 1 mg / L, the slime peeling effect was slightly reduced as compared with Example 1, but the bactericidal effect was equivalent.

<Example 4>
In Example 1, the slime peeling effect and bactericidal effect were evaluated in the same manner as in Example 1 except that the time from the addition of the pre-treatment agent to the addition of the post-treatment agent was changed as shown in Table 4. did. The results are shown in Table 4.

  When the treatment from the addition of the pre-treatment agent to the addition of the post-treatment agent was shortened to 0.1 hour (Example 4-1) and 1 hour (Example 4-2), the time was increased. When treated, the slime peeling effect and the bactericidal effect were equivalent to those of Example 1 (0.5 hours). Moreover, even when 3 hours or more have elapsed after the addition of sodium hypochlorite to the former stage, when a quaternary ammonium salt is added as a later stage treatment (Example 4-3, Example 4-4), sufficient slime peeling effect and sterilization Although an effect is acquired, it turns out that the slime peeling effect has fallen compared with the case where it adds 0.5 hours later (Example 1), and it is more preferable to carry out a post-process within a fixed time.

<Example 5>
In Example 1, the slime peeling effect and the bactericidal effect were evaluated in the same manner as in Example 1 except that the treatment temperatures of the former stage and the latter stage were changed as shown in Table 5. The results are shown in Table 5.

  From the result of Table 5, it is better compared with Example 1 currently processed at 20 degreeC by processing the process temperature of a front | former stage and a back | latter stage at 40-70 degreeC (Example 5-2, 5-3). A slime peeling effect was obtained. Moreover, from the results of Table 5, when the treatment temperature is 2 ° C. or 80 ° C., the slime peeled state is not so good (Reference Examples 5-1 and 5-2), and a suitable temperature for the treatment of the present invention. You can see that there is a region.

<Example 6>
In Example 1, the slime peeling effect and the bactericidal effect were evaluated in the same manner as in Example 1 except that the treatment pH of the former stage and the latter stage was changed as shown in Table 6. The results are shown in Table 6.
In the former treatment, sodium hydroxide was added and the treatment pH was treated at 9.6, so that a better slime peeling effect was obtained as compared with Example 1 where treatment was carried out at pH 8.2.

<Example 7>
In Example 1, the slime peeling effect and the bactericidal effect were evaluated in the same manner as in Example 1 except that the circulation time after the post-treatment was changed as shown in Table 7. The results are shown in Table 7.
If the stirring time after the post-treatment is 0.1 hour or more (Example 7-1), a certain slime peeling effect and bactericidal effect can be obtained. Moreover, the more favorable slime peeling effect was acquired by making the stirring time after a back | latter stage process into 6 hours (Example 7-3).

<Example 8>
In Example 1, the slime peeling effect and the bactericidal effect were evaluated in the same manner as in Example 1 except that the surfactant-based chemical used in the subsequent treatment was changed as shown in Table 8. The results are shown in Table 8.

  Even if the surfactant-based agent used in the post-treatment is treated with a cationic surfactant, an anionic surfactant, an amphoteric surfactant and a nonionic surfactant under the same conditions as in Example 1, slime release effect And the bactericidal effect was good. Among them, when a quaternary ammonium salt which is a cationic surfactant was used, the slime peeling effect and the bactericidal effect were the best.

DESCRIPTION OF SYMBOLS 1 Cooling water system 2 Cooling tower 3 Filling material layer 4 Blower fan 5 Sprinkling pipe 6 Cooling water tank 7 Cooling water 8 Cooling water circulation piping 9 Pump 10 Heat exchanger 11 Processing unit 12 Chemical tank (for chlorine-based oxidizing agent)
13 Infusion pump 14 Drug tank (for surfactant-based drugs)
15 Infusion pump 16 Residual halogen meter 17 Controller

Claims (6)

  A cooling water-based slime stripping and microbial sterilization, wherein a chlorine-based oxidizing agent is contained in the cooling water system in the former stage and a surfactant-based agent is contained in the cooling water system in the latter stage.   The amount of addition of the chlorinated oxidizer in the former stage is 0.1 to 1000 mg / L as effective chlorine, and the amount of addition of the surfactant-type chemical in the latter stage is 1-1000 mg / L as the component concentration. Item 2. A processing method according to Item 1.   The treatment method according to claim 1 or 2, wherein the surfactant in the subsequent stage is added 0.1 to 3 hours after the addition of the chlorinated oxidant in the preceding stage.   The processing method according to any one of claims 1 to 3, wherein the temperature in the cooling water system is processed at 5 to 70 ° C.   The treatment method according to any one of claims 1 to 4, wherein an acid or an alkali agent is added, and the pH in the cooling water system is treated at 5 to 12.   The cooling water type processing agent set for using for the processing method of any one of Claims 1-5 which combines a chlorine-type oxidizing agent containing chemical | medical agent and surfactant type chemical | medical agent containing chemical | medical agent.

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