KR20230137543A - Stabilized halogen-based oxidizing agent composition for sterilization of microorganisms and inhibition and removal of biofilm in aqueous systems, and method for preparing and using the same - Google Patents

Abstract

The present invention relates to: a stabilized halogen-based oxidizing agent composition for sterilizing microorganisms and inhibiting and removing biofilm formation in aqueous systems, which is capable of sterilizing microorganisms, inhibiting and removing biofilms in aqueous systems, can be universally applied in aqueous systems with different water environments, and in filtration systems using reverse osmosis membranes or microporous filtration membranes, can effectively control clogging without damaging the membrane, allowing the interval between cleaning cycles to be increased, and can minimize harmful pollution to the human body, and contains a stabilized chlorine-based oxidizing agent, a stabilized bromine-based oxidizing agent, and a bromine ion source; a preparation method thereof; and a use method thereof.

Description

Stabilized halogen-based oxidizing agent composition for sterilization of microorganisms and inhibition and removal of biofilm in aqueous systems, and a method of producing and using the same. method for preparing and using the same}

The present invention relates to a stabilized halogen-based oxidizing agent composition for sterilizing microorganisms and inhibiting and removing biofilm formation in an aqueous system, and a method of making and using the same. More specifically, it is possible to sterilize microorganisms, suppress and remove biofilm formation in aqueous systems, allow universal application in aqueous systems with different water environments, and prevent clogging without damaging the membrane in filtration systems using reverse osmosis membranes or microporous filtration membranes. It relates to a stabilized halogen-based oxidizing agent composition that can effectively control the phenomenon, increase the interval between cleaning cycles, and minimize the occurrence of pollution harmful to the human body, and methods of manufacturing and using the same.

In the present invention, an aqueous system includes a water treatment system and refers to any system that stores, uses, or processes large amounts of water, specifically, building cooling towers, water supply systems, swimming pools, and industrial water systems. Examples include water systems, water thermal storage systems, pure water production systems, wastewater treatment systems, cooling systems such as heat exchangers, papermaking process systems, and filtration systems.

One of the biggest problems in aqueous systems is contamination by microorganisms such as bacteria, fungi, and algae. If these microorganisms proliferate excessively in an aqueous system, bad odors may occur, pathogens such as Legionella may proliferate, thermal efficiency of the cooling process will decrease due to water quality deterioration, filtration system deterioration in the filtration process may occur due to biofilm formation, etc., and product damage in the papermaking process may occur. It causes many problems such as quality deterioration.

Various methods have been applied to prevent and remove contamination by microorganisms in conventional aqueous systems. These can be broadly divided into methods using non-oxidizing disinfectants and methods using oxidizing disinfectants. there is.

Non-oxidizing disinfectants refer to chemical agents that selectively react with specific cells of microorganisms and sterilize them by inhibiting their metabolism. Representative examples include isothiazolone, glutaraldehyde, quaternary ammonium, and polyhexamethylene guanidine. I can hear it. Non-oxidizing disinfectants have low versatility due to their selective application to specific microorganisms, and when used for a long period of time, microorganisms develop resistance to the disinfectant, causing the inconvenience of having to periodically change the type of disinfectant. For this reason, non-oxidizing disinfectants are of limited use.

Oxidizing disinfectants refer to chemical agents that sterilize the cell components of microorganisms by chemically oxidizing them using oxidizing power. Halogen-based chemicals, especially chlorine-based disinfectants, belong to this class. Taking hypochlorite solution, a representative chlorine-based oxidizing agent, as an example, the hypochlorite solution consists of hypochlorous acid and hypochlorite ions dissolved in water, and hypochlorous acid, which has a relatively high oxidizing power, preferentially sterilizes microorganisms. Hypochlorite solutions have high sterilizing power and are relatively inexpensive, so they are widely used throughout the industry.

However, chlorine-based oxidizers have many problems arising from their high oxidizing power. Taking hypochlorite as an example, hypochlorite can react with organic matter in water due to its high oxidizing power to produce carcinogenic disinfection by-products, can easily corrode nearby metal facilities, and is also highly volatile, which is harmful to the human body. There is a high possibility of releasing substances into the atmosphere.

Due to these problems, the government is imposing many restrictions on the use of chlorine-based oxides, and in particular, a notice was announced to designate chlorine-based oxidants above a certain concentration as toxic starting from 2023. As chlorine-based oxides are currently widely used in related industries, the development of materials that can replace chlorine-based oxidants is urgently required due to this announcement.

In addition, unstabilized halogen-based oxidants have little effect on inhibiting or removing biofilm. This is because the oxidation reaction occurs quickly due to the high oxidation power, so when it comes into contact with the biofilm, most of it is consumed in the oxidation reaction on the surface of the biofilm and hardly penetrates into the interior of the biofilm. In particular, in the filtration system, oxidation does not occur properly at the portion attached to the interface of the filtration membrane or pore, so the biofilm cannot be removed from the interface. A biofilm removal effect can be obtained by drastically increasing the amount of halogen-based oxidizing agent used, but due to the problems that occur when using excessive amounts of halogen-based oxidizing agent as seen above, it is realistically impossible to significantly increase the amount used.

As a prior art, there is a method of preparing and using a halogen-based oxidizing agent as a stabilized halogen-based oxidizing agent. Taking hypochlorite, a chlorine-based oxidizing agent, as an example, this method involves reacting it with sulphanic acid to produce stabilized hypochlorite, that is, chlorinated sulfamate (chlorosulfamate). Stabilized hypochlorite has low volatility and generates almost no odor, and also has a low degree of dissociation, so hypochlorous acid (with high oxidizing power) is produced at a very low rate, so it can solve many problems inherent in existing hypochlorite. However, these stabilized chlorine-based oxidizers have a low sterilization effect, and it is difficult to achieve the desired microbial sterilization effect with just them.

Proposed to solve these problems with stabilized halogen-based oxidants, there is Korean Patent No. 1911929, registered on October 19, 2018. This Korean patent proposes using a combination of a stabilized halogen-based oxidant with a high dissociation constant and a stabilized halogen-based oxidant with a low dissociation constant as a disinfectant in order to solve the problems with the stabilized halogen-based oxidizer seen previously. will be. As an example, a composition in which a stabilized bromine-based oxidant with a high dissociation constant and a stabilized chlorine-based oxidant with a low dissociation constant are mixed in an appropriate ratio is used as a disinfectant. By doing this, it is possible to solve the problems of the conventional chlorine-based oxidizing agent and at the same time secure the oxidizing power (sterilizing power) required for a given aqueous system.

The Korean patent also proposed using a mixture of bromine ions with a stabilized chlorine-based oxidizing agent instead of a stabilized bromine-based oxidizing agent. The reason is that bromine ions are mixed with a stabilized chlorine-based oxidizing agent to form hypobromic acid, so the same effect as mixing with a stabilized bromine-based oxidizing agent can be obtained.

The inventor of this application is also a co-inventor of the aforementioned Korean Patent No. 1911929. The present inventor continued research related to the above Korean patented invention and found that the effect of the above Korean patented invention on inhibiting or removing biofilm formation was limited. In other words, it was confirmed that the composition of the Korean patented invention was also mostly consumed in the oxidation reaction on the surface of the biofilm, and did not induce oxidation inside the biofilm. In particular, in reverse osmosis membranes and ultrafiltration systems, it was not possible to sufficiently induce the removal of biofilm from the interface of the filtration membrane or filtration pores.

The present invention was created to solve the above problems, and the purpose of the present invention is to provide a halogen-based oxidizing agent composition that can effectively sterilize microorganisms and prevent and remove biofilm formation in an aqueous system, as well as a method of producing and using the same. It is done.

Another object of the present invention is to provide a halogen-based oxidizing agent composition that can effectively control microorganisms while minimizing pollution in aqueous systems.

Another object of the present invention is to provide a halogen-based oxidizing agent composition that can effectively respond to a given pH condition of an aqueous system.

Another object of the present invention is to provide a halogen-based oxidizing agent composition that can increase the cleaning cycle interval of an aqueous system including a filtration system without damaging the filtration membrane.

Another object of the present invention is to provide a halogen-based oxidizing agent composition that can be universally applied to most aqueous systems.

The present invention for achieving the above effect is a composition in which a stabilized chlorine-based oxidant, a stabilized bromine-based oxidant, and a bromine ion source are mixed.

The stabilized chlorine-based oxidizing agent includes chlorosulfamate, chlorinated 5,5-dialkyl hydantoin, chlorinated arylsulfonamide, chlorinated succinimide, One or two or more selected from the group consisting of chlorinated glycoril, chlorinated cyanuric acid, and bromochlorodimethylhydantoin BCDMH (1-bromo-3-chloro-5,5-dimethylhydantoin) It may be a mixture.

The stabilized brominated oxidizing agent may be one or a mixture of two or more selected from the group consisting of bromosulfamate and 1,3-dibromo-5,5-dimethyl hydantoin.

The bromide ion source may be one or two or more selected from the group consisting of bromide ions, or a mixture thereof.

The mixing ratio in the composition is (a) stabilized chlorine-based oxidizing agent: 1 to 20% by weight, (b) stabilized bromine-based oxidizing agent: 1 to 20% by weight, (c) bromine ion source: 1 to 15% by weight, The balance may consist of water.

Stabilized chlorine-based oxidants have a low degree of dissociation, while stabilized bromine-based oxidants have a high degree of dissociation. In addition, bromide ions consume hypochlorous acid that dissociates from the stabilized chlorine-based oxidizing agent, which ultimately serves to increase the degree of dissociation of the stabilized chlorine-based oxidizing agent.

In the present invention, the mixing ratio of the stabilized chlorine-based oxidizing agent and the stabilized bromine-based oxidizing agent is set to 1-20% by weight, respectively. If the oxidizing agent is less than 1% by weight, there is no advantage obtained by mixing these components, and the mixing ratio of the stabilized chlorine-based oxidizing agent and the stabilized bromine-based oxidizing agent is 1-20% by weight. The reason it is set below is because if it exceeds 20% by weight, it causes instability in the manufactured product.

Meanwhile, in the present invention, the bromide ion source is added at 1-15% by weight, because bromide ions form hypochlorous acid through a reaction with hypochlorous acid that dissociates from stabilized chlorine, so the molar ratio of stabilized chlorine is Because it can't be bigger than that.

Since the bromine ion source contained in the composition of the present invention must be maintained in an unreacted state, the pH of the composition must be maintained at 12 or higher.

Meanwhile, the present invention is an example of a method of using the composition, which may be a method of adding the composition so that the free halogen concentration in the treated water is 5.0 ppm or less based on chlorine. Also, based on chlorine, the combined halogen concentration in the treated water may be added to be 100 ppm or less.

In the present invention, the concentration of free halogen with high oxidizing power is preferably within 5.0 ppm. Although it may be exceeded intermittently or irregularly depending on the surrounding environment and the characteristics of the water-based system, if used continuously in excess of 5.0 ppm, serious environmental hazards may occur in the surrounding environment, such as corrosion of metals and oxidation of not only microorganisms but also various organic materials. It can result. The combined halogen concentration can be determined by subtracting the free halogen concentration remaining after reacting with organic matter, including microorganisms in the aqueous system, from the total halogen concentration after adding the composition to the aqueous system. The free halogen concentration is based on stabilized chlorine with a low degree of dissociation. It is desirable to be within 20 times of , that is, within 100 ppm.

The molar ratio of the stabilized chlorine-based oxidizing agent and the stabilized bromine-based oxidizing agent is 20:1 to 1:20, and the stabilized halogen (sum of the stabilized chlorine-based oxidizing agent and the stabilized bromine-based oxidizing agent) and the bromine ion source The molar ratio may range from 20:1 to 1:2. The reason is the same as the reason for limiting the weight ratio of each constituent oxidizing agent seen above.

The composition of the present invention has a clean system and relatively few microorganisms, but in a process composed of materials vulnerable to free halogens such as polyamide, it is desirable to adjust the free halogen concentration to 0.5 ppm or less. To this end, stabilized chlorine and bromine ions are used as the main components. It can be composed of a minimum stabilized bromine composition ratio to sterilize microorganisms entering the system.

Materials used in processes with porous membranes used not only in pure water production but also in ultrafiltration membranes (UF) and membrane bioreactors (MBR) used for wastewater recycling have very high oxidation resistance to free halogens, but the free halogen concentration is 5 ppm. Using it within a range can minimize the impact on the surrounding environment.

In addition, unlike the above, in the cooling water process, in most cases, it is operated at pH 8 or higher, so not only hypochlorous acid is dissociated by stabilized bromine, but also hypochlorous acid is produced by hypochlorous acid and bromide ions dissociated from stabilized chlorine. The role of bromate is important. In this case as well, it is preferable to use the free halogen concentration within 2 ppm, but in order to remove the biofilm, it is advisable to maintain the total halogen concentration at 0.1 ppm or more than the free halogen concentration to allow stabilized chlorine and bromide ions to penetrate into the biofilm. desirable.

The degree of dissociation of chlorine-based oxidants and bromine-based oxidants varies depending on the pH state. The reference chart below shows the degree of dissociation of hypochlorite and hypobromite that changes depending on pH status.

[Reference diagram]

As shown in the reference diagram, when pH is low, the hypochlorous acid ratio increases, and when pH is high, the hypochlorite ion ratio increases. For example, at pH 7.5, hypochlorous acid with high oxidizing power and half of hypochlorous acid ions with low oxidizing power coexist, but as pH increases, the ratio of hypochlorous acid ions increases significantly. In comparison, in the case of hypobromic acid, it can be seen that the ratio of hypobromic acid and hypobromous acid ions becomes the same at pH 8.5. Therefore, when the pH is high, it is shown that generating hypobromic acid rather than hypochlorous acid can effectively remove microorganisms.

Since the characteristics of hypochlorite and hypobromite are the same, it is desirable to mix and use a stabilized chlorine-based oxidizing agent and a stabilized bromine-based oxidizing agent in an appropriate ratio, taking into account the characteristics of a given aqueous system, especially pH.

The composition of the present invention can be universally applied to most aqueous systems, especially processes with microporous membranes such as ultrafiltration membranes (UF), membrane bioreactors (MBR), and microfiltration (Nano Filter, Micro filter). can be applied effectively.

The halogen-based oxidizing agent composition of the present invention is capable of sterilizing microorganisms, suppressing and removing biofilms in aqueous systems, and can be universally applied in aqueous systems with different water quality environments, and can be used as a filtration membrane in filtration systems using microporous filtration membranes. It is useful in that it can effectively control clogging without causing damage, increasing the interval between cleaning cycles, and minimizing harmful pollution to the human body.

In aqueous systems, bacteria exist in suspension (planktonic form), but when they attach to the air wall, they form a sessile biofilm. Biofilm is a biofilm formed by a microbial community held together by adhesive polymers called EPS (Extracelluar Polymeric Substances), which are naturally produced by microorganisms.

In a biofilm network, bacterial cells operate through a collective survival system rather than individually, creating channels that supply nutrients and water to cells within the biofilm. Because bacteria create biofilms as a kind of protection mechanism and as a better survival strategy against the environment, the cells within biofilms are highly resistant to commonly applied cleaning and disinfection processes. For example, when hypochlorite is added to sterilize microorganisms in an aqueous system, it is unable to penetrate into the biofilm despite its high oxidizing power, which may be due to the biofilm's defense function operating. You can.

In order to avoid the defense function of the biofilm from operating, the present invention allows a halogen-based material with low oxidizing power (low reactivity) to penetrate into the biofilm, and the infiltrated halogen-based material is combined with other halogen materials. When combined, it becomes a halogen-based oxidizing agent with high oxidizing power, which sterilizes bacteria inside the biofilm or causes the biofilm to fall off from the interface.

The halogen-based oxidizing agent composition of the present invention is a composition in which a stabilized chlorine-based oxidizing agent, a stabilized bromine-based oxidizing agent, and a bromine ion source are mixed, and when stored under conditions of pH 12 or higher, bromine ions are maintained in an unreacted state.

When the composition of the present invention in this state is introduced into an aqueous system, due to the low degree of dissociation of stabilized chlorine, the introduced bromide ions are dispersed throughout the aqueous system in an unreacted state, and may especially penetrate into the interior or interface of the biofilm. There will be. Then, it reacts with hypochlorous acid that dissociates from the stabilized chlorine-based oxidant that has penetrated into the interior or interface of the biofilm and changes into hypobromic acid with high oxidizing power. Hypobromous acid oxidizes EPS, which brings the biofilm into close contact with the interface, weakening the adhesion force, allowing the biofilm to separate from the interface.

As an example, the manufacturing method of the present invention includes the following steps.

1st process: preparing solution 1 by adding an alkaline compound and sulfamic acid to water;

Second process: A process of preparing solution 2 by adding and dissolving a bromine ion source in NaOCl liquid;

Third process: preparing solution 3 by mixing solution 2 with solution 1; and

Fourth process: A process of dissolving and mixing a bromine ion source into solution 3.

In the above processes, the alkaline compound may be one or a mixture of two or more selected from the group consisting of sodium hydroxide or potassium hydroxide, and the bromide ion source may be NaBr.

Regarding the manufacturing method of the present invention, the chemical reaction will be explained with an example focusing on the ionic reaction as follows.

Equation (1):

NH ₂ SO ₃ H + Na ⁺ + OH ^- → NH ₂ SO ₃ ^- + Na ⁺ +H ₂ O

Equation (2):

HOCl ₊ ^{Br -} _x → HOCl _(1-x) + _HOBr

Equation (3):

NH ₂ SO ₃ ^- + HOCl _(1-x) + HOBr _x → NHBrSO ₃ ^- _x + NHClSO ₃ ^- _(1-X)

Equation (4):

NHBrSO ₃ ^- _x + NHClSO ₃ ^- _(1-x) +Br ^- _y → NHBrSO ₃ ^- _x + NHClSO ₃ ^- _(1-x) + Br ^- _y

(In the above equations, X= 0.01~0.99, Y=0.01~1)

Equation (1) shows the dissolution/neutralization process of sulfamic acid and caustic soda solution. In this process, caustic soda does not cause a chemical reaction with sulfamic acid, but serves to dissolve/neutralize sulfamic acid. When caustic soda is solid or has a high concentration, heat of dissolution is generated when mixed with water, so a cooling process is necessary. Even when sulfamic acid is added to the solution, cooling is necessary because heat is generated due to the acid-alkali neutralization process. During this reaction, the temperature of the solution is preferably cooled to within 40°C to ensure the stability of sulfamic acid in the alkaline solution. Neutralization of caustic soda and sulfamic acid is possible if the molar ratio is more than 1:1, but since the neutralization titration curve is very steep from pH 3 to pH 12, caustic soda and sulfamic acid must be added so that the pH can be at least 12 or higher after the neutralization process. A ratio is required.

Equation (2) is the hypobromic acid production process. The production rate of hypobromous acid is determined depending on the amount of bromide ion input. The equation (2) reaction does not generate much heat, but in order to minimize problems due to the volatility of hypobromous acid produced, it is desirable to carry out the reaction at 40°C or lower, preferably 25°C or lower. In theory, if the bromide ion input is equal to the molar ratio of hypochlorous acid input, all hypochlorous acid is generated as hypochlorous acid. Therefore, the molar ratio of bromide ions introduced can be adjusted from 1% to 99% of hypochlorous acid to adjust the production rate of hypochlorous acid and hypobromous acid.

Equation (3) shows that sulfamic acid reacts with unreacted hypochlorous acid in the reaction of equation (2) and hypobromic acid produced in the reaction of equation (2), producing stabilized chlorine and stabilized bromine. The molar ratio of sulfamic acid and hypohalogenic acid (sum of hypochlorous acid and hypobromic acid) should be equal to or less than hypohalogenic acid, but even in unavoidable cases, it should not exceed 20% as much as possible for the stability of the product. The stabilizing halogen produced by the reaction of hypohalogen acid and sulfamic acid may lose its oxidizing power when stored under strong alkaline conditions if the ratio of hypohalogen acid increases and the ratio of dichlorosulfamate along with monochlorosulfamate increases.

Equation (4) is performed under conditions where the pH is maintained above 12. As shown in the reference diagram, at pH 12 or higher, hypochlorous acid and hypobromic acid are hardly dissociated, so the introduced bromide ion exists in the mixture as unreacted bromide ion. This composition, which is a mixture of a stabilized chlorine-based oxidizing agent and a stabilized bromine-based oxidizing agent with bromide ions, is a final product. Therefore, for long-term storage without reducing oxidizing power, the pH is set to 12 or higher, preferably 13 or higher, with sulphanic acid and caustic. Add soda. At this time, the caustic soda solution is generally initially added all at once, but it can be added in installments for product stability and storage.

The present invention will be described below based on examples. The scope of the present invention is not determined by the examples, and those skilled in the art will be able to implement various modifications of the content described herein within the scope of the present invention.

The combined and free halogen composition of each case sample was measured by the DPD (N,N-diethyl-p-phenylenediamine) method using a Hach DR-3900 instrument by adding it to 25ppm compared to distilled water in both comparative examples and examples. The measured concentrations are free halogen and total halogen, and subtracting free halogen from total halogen results in the combined halogen concentration.

(Comparative Example 1)

Comparative Example 1 adopts the method mentioned in Korean Patent No. 1911929 of preparing and then mixing stabilized chlorine and stabilized bromine, respectively.

Specifically, NaOH was added to distilled water to prepare an alkaline solution, and sulphanic acid was added to prepare solution A. NaOCl (12%) solution was added to solution A to prepare a stabilized chlorine-based oxidizing agent. In the manufacturing process of Solution A, the glass flask was placed in a water bath and cooled so that the reaction temperature did not exceed room temperature (25°C).

NaOH was added to distilled water to prepare an alkaline solution, and sulphanic acid was added to prepare solution A. Solution B was prepared by adding NaBr1 to NaOCl (12%) solution. After mixing solution A with solution B, a stabilized bromine-based oxidizing agent was prepared.

A stabilized chlorine-based oxidizing agent and a stabilized bromine-based oxidizing agent were mixed in a ratio of 8:2. In the process of Solution B, the glass flask was cooled in a water bath so that the reaction temperature did not exceed room temperature (40°C or lower, preferably 25°C or lower).

(Comparative Example 2)

Comparative Example 2 adopts the method of mixing stabilized chlorine and bromine ion sources mentioned in Korean Patent No. 1911929.

In Comparative Example 2, an alkaline solution was prepared by adding NaOH to distilled water, and solution A was prepared by adding sulphanic acid.

Solution B was prepared by adding NaBr1 to NaOCl (12%) solution. Partially stabilized bromine was prepared by mixing solution B with solution A.

In all of the above processes, the glass flask was cooled in a water bath so that the reaction temperature did not exceed room temperature (40°C, preferably 25°C).

Table 1 shows the total halogen content for Comparative Example 1, which was prepared by mixing a stabilized chlorine-based oxidant and a stabilized brominated oxidant, and Comparative Example 2, which was prepared using a method of partially generating hypobromous acid in the stabilized chlorine-based oxidant. It shows the results of measuring and free halogen. As shown in Table 1, the total halogen and free halogen in Comparative Example 1 and Comparative Example 2 were almost the same. From these results, it can be seen that if the contents of hypochlorous acid and NaBr1 are the same, a product having the desired total halogen and free halogen values can be manufactured by mixing stabilized chlorine and stabilized bromine.

division Comparison 1 Comparison 2 stabilized chlorine stabilized bromine Comparative Example 1 (8:2) Distilled water 28 19 26.2 26.2 NaOH 6 6 6 6 Sulfan Mountain 10 10 10 10 NaBr1 9 1.8 1.8 NaOCl solution 56 56 56 56 NaBr2 Total and free halogens Total halogens (ppm) 1.38 1.32 1.36 1.34 Free Halogen (ppm) 0.05 1.22 0.27 0.26 % (free halogen/total halogen) 3.6% 92.4% 20% 19.4%

(Example 1)

This example was carried out to confirm whether the bromide ion source, which is one of the components of the present invention, is maintained in an unreacted state under conditions of pH 12 or higher. In this example, the input amounts of the stabilized chlorine-based oxidant and the stabilized bromine-based oxidant were kept almost the same, but the input amounts of the bromine ion source were changed to 0.5% by weight, 1.0% by weight, 2.0% by weight, and 3.0% by weight, respectively. An experiment was conducted to measure these free halogens and total halogens.

Specifically, NaOH was added to distilled water to prepare an alkaline solution, and sulphanic acid was added to prepare solution A. Solution B was prepared by adding NaBr1 to NaOCl (12%) solution. After mixing solution B with solution A, NaBr2 was added to prepare a mixture, and this composition was stored under conditions of pH 12 or higher. In all of the above manufacturing processes, the reaction temperature was cooled to 40°C, preferably not exceeding 25°C. Conditions 1 to 4 keep the ratios of other components the same and only vary the ratio of NaBr2. The composition of conditions 1 to 4, total halogen and free halogen, etc. are shown in Table 2.

division Condition 1 (% by weight) Condition 2
(weight %) Condition 3
(weight %) Condition 4
(weight %) Distilled water 27 26.5 25.5 24.5 NaOH 6 6 6 6 Sulfan Mountain 10 10 10 10 NaBr1 0.5 0.5 0.5 0.5 NaOCl solution 56 56 56 56 NaBr2 0.5 1.0 2.0 3.0 Total and free halogens Total halogens (ppm) 1.34 1.30 1.31 1.30 Free Halogen (ppm) 0.05 0.05 0.05 0.05 % (free halogen/total halogen) 3.7% 3.8% 3.8% 3.8%

As shown in Table 2, despite increasing the amount of NaBr2 from conditions 1 to 4, the ratio of free halogen to bound halogen was almost unchanged. The microbial sterilizing power (oxidizing power) of the oxidizing disinfectant is proportional to the concentration of free halogen, but as shown in Conditions 1 to 4, the increase in NaBr2 did not contribute to the increase in oxidizing power and existed in the form of bromine ion. It can be understood that such unreacted NaBr2 is in a state where it can easily penetrate into the interior of the biofilm when it is later introduced into the aqueous system.

In the measurement experiment of Example 1, total halogen and free halogen values were measured by the DPD method using a Hach device. Since chlorine and bromine were not measured separately by the Hach method, the halogen concentration including both chlorine and bromine was expressed. Bromine and chlorine are not distinguished, but relative comparisons are possible because the concentration of chlorine input is kept constant, that is, the number of moles of chlorine input is constant.

(Example 2)

In this example, the amount of bromine ion source input was the same at 3% by weight, but the amount of NaBr1 input to prepare solution B was changed to 0.5% by weight, 1.0% by weight, and 1.5% by weight, so that the free halogen And an experiment was conducted to measure the total halogen concentration.

As in Example 1, an alkaline solution was prepared by adding NaOH to distilled water, and solution A was prepared by adding sulphanic acid. Solution B was prepared by adding NaBr1 to NaOCl (12%) solution. After mixing solution A and solution B, NaBr2 was added to prepare a mixture. In all of the above manufacturing processes, the reaction temperature was cooled to not exceeding 40°C, preferably not exceeding 25°C. Conditions 5 to 7 keep the ratios of other components the same and only vary the ratio of NaBr1. The composition of conditions 5 to 7, total halogen and free halogen, etc. are shown in Table 3.

division Condition 5 (% by weight) Condition 6
(weight %) Condition 7
(weight %) Distilled water 24.5 24 23.5 NaOH 6 6 6 Sulfan Mountain 10 10 10 NaBr1 0.5 1.0 1.5 NaOCl solution 56 56 56 NaBr2 3 3 3 Combined halogens and free halogens Total halogens (ppm) 1.29 1.29 1.28 Free Halogen (ppm) 0.11 0.21 0.28 % (free halogen/total halogen) 8.5% 16.3% 21.9%

Conditions 4 to 7 show that increasing the amount of NaBr1 increases the production rate of stabilized brominated oxidant in the mixture. Since the stabilized brominated oxidant has a high degree of dissociation, as the amount of NaBr1 added increases, the ratio of free halogen generation to bound halogen significantly increases. In other words, since stabilized bromine is generated in proportion to the amount of NaBr1 added, the free halogen production rate, or oxidation power, increases. From Table 3, it can be seen that when the NaBr1 content is increased, the free halogen production rate increases, that is, the oxidation power increases, regardless of the NaBr2 content.

(Example 3)

In this example, an experiment was conducted to measure free halogen and bound halogen while keeping the total amount of NaBr1 and NaBr2 constant, increasing the input amount of NaBr1 and correspondingly decreasing the amount of NaBr2.

As in Example 1, an alkaline solution was prepared by adding NaOH to distilled water, and solution A was prepared by adding sulphanic acid. Solution B was prepared by adding NaBr1 to NaOCl (12%) solution. After mixing solution A and solution B, NaBr2 was added to prepare a mixture. In all of the above manufacturing processes, the reaction temperature was cooled to not exceeding 40°C, preferably not exceeding 25°C. Conditions 8 to 10 keep the ratios of other components the same and only vary the amounts of NaBr1 and NaBr2. The composition of conditions 8 to 10, total halogen and free halogen, etc. are shown in Table 4.

division Condition 8 (% by weight) Condition 9
(weight %) Condition 10
(weight %) Distilled water 23 23 23 NaOH 6 6 6 Sulfan Mountain 10 10 10 NaBr1 One 2 3 NaOCl solution 56 56 56 NaBr2 4 3 2 Combined halogens and free halogens Total halogens (ppm) 1.28 1.29 1.29 Free Halogen (ppm) 0.22 0.34 0.42 % (free halogen/total halogen) 17.2% 26.4% 32.5%

In conditions 8 to 9, the total amount of NaBr input was kept constant and the rate of free halogen production was confirmed along with total halogen and free halogen concentration measurements under the condition that the amount of NaBr2 input decreased as the amount of NaBr1 increased. As can be seen in Table 4, there was almost no change in the combined halogen concentration, but it was confirmed that the free halogen concentration increased as the amount of NaBr1 added increased. In other words, it was confirmed that the amount of NaBr2 added was mixed without reaction.

(Example 4)

Example 4 was conducted to confirm the effectiveness of applying the present invention to an actual aqueous system. In this example, chlorosulfamate as a stabilized chlorine-based oxide, bromosulfamate as a stabilized bromine-based oxide, and bromide ion as a bromine ion source were added to distilled water and mixed, and long-term storage was achieved. For this purpose, the pH was adjusted to 13 or higher.

The composition was introduced into an ultrafiltration membrane system and the differential pressure change was measured. The specifications and operating specifications of the ultrafiltration membrane system that is the subject of testing in this example are as follows.

division Operation specifications texture Polyvinylpyrrolidone/polyethersulfone mixture Maximum pressureMax. 300 kPa Pore size 20 nm maximum backwash pressure 300 kPa driving style Dead-end with regular backwash -permeate only Application temperature (℃) 0~40

The surface of the ultrafiltration membrane as described above is composed of numerous micropores, and the method of filtering through the center of the hollow fiber (dead end flow) is very sensitive to pore clogging due to the creation of fine particles or biofilm, and this reaction is caused by the ultrafiltration membrane. It is possible to immediately check the increase in differential pressure installed before and after.

Table 6 shows the change in differential pressure of the ultrafiltration process according to the amount added while hypochlorite and the compositions of Comparative Examples 1 and 2 were added to the ultrafiltration process. Even when 20 ppm hypochlorite was added, the differential pressure continued to increase without decreasing. After cleaning (Cleaning In Place), the compositions of Comparative Examples 1 and 2 were subsequently added, but the differential pressure continued to increase. According to the three types of cases, if the differential pressure increased within the first 6 hours, the tendency to accelerate over time was the same. From this, it was confirmed that if the formation of biofilm is not controlled in the early stage, the increase in differential pressure cannot be prevented.

In this example, the composition under condition 10 was added at 20 ppm compared to the process water after cleaning (CIP) the ultrafiltration membrane. At this time, the total halogen concentration was about 0.7 ppm, the free halogen concentration was about 0.2 ppm, and the free/combined halogen ratio was about 31%, which was a normal input. Table 7 shows the changes in differential pressure, total halogen, and free halogen concentration of the ultrafiltration process according to the input amount of the composition of this example.

As can be seen in Table 7, the total halogen and free halogen values were maintained with little change for two days while the input amount was maintained at 20ppm, and surprisingly, no slight increase in differential pressure occurred.

Thanks to these results, as a result of reducing the input amount to 15 ppm, the total halogen concentration was maintained at about 0.6 ppm and the free halogen concentration was maintained at about 0.15 ppm, and the differential pressure did not increase. The input amount was reduced to 7 ppm, and the total halogen was measured to be about 0.4 ppm and the free halogen was measured to be about 0.09 ppm, but the differential pressure was maintained without an increase.

Finally, as a result of reducing the input amount to 5 ppm, the total halogen was about 0.25 ppm and the free halogen was about 0.08 ppm, maintaining the free/total halogen ratio at about 31%, and surprisingly, no increase in differential pressure occurred even at this low concentration.

In particular, considering the surface area of the numerous hollow fibers that make up the ultrafiltration membrane and the process of filtration through 20 nm micropores on the surface of the hollow fibers, the surprising effect of bromide ions added together with stabilized chlorine and stabilized bromine is shown in Table 7. Confirmed.

(Example 5)

The MBR (Membrane Bio Reactor) process is a process that separates microorganisms and treated water by immersing a hollow fiber membrane in a bioreactor to recycle contaminated water. It is a method of increasing the recycling rate of water resources.

The module composed of hollow fiber membrane used in this process has an important function of increasing the recyclability of water quality by removing bacteria and suspended solids and nutrients. The hollow fiber membrane used here is made of PVDF (polyvinylidene fluoride), which has high resistance to high-concentration chemicals and has micropores, and various suspended substances are filtered out by the micropores. In this process, due to the phenomenon of clogging of the hollow fiber membrane, the clogged micropores are removed by periodic cleaning with a cleaning solution such as hypochlorite solution.

In order to check this effect, a mini module was manufactured, a general hollow fiber membrane with reduced water permeability was prepared, and a cleaning solution was injected into the hollow fiber from a height of 50 cm. In order to check the backwash effect, the water permeability was measured by immersing the cleaning solution for a certain period of time. Measured. The hollow fiber was manufactured with a length of 20 cm, and the results of measuring the amount of water transmitted for 1 minute after applying 1 Bar pressure are shown in Table 8.

cleaning chemicals Before washing NaOCl solution Comparative Example 1 Condition 9 Condition 8 Concentration (ppm) - 1,000 800 800 800 Total cleaning time - 2 4 8 8 8 8 (hr) backwash - One 0 One 0 One 0 One 0 One 0 One 0 immersion - One 2 3 4 7 8 7 8 7 8 7 8 Water permeability (LMH/bar) 554 1170 1070 1120 1107 1255 1230 985 1035 1205 1220 1095 1120 recovery rate 45% 95% 87% 91% 90% 102% 100% 80% 84% 98% 99% 89% 91%

Since NaOCl (12%) solution is widely used in the field, a comparative test was conducted on the mini module with a cleaning time of 8 hours and water permeability restored to about 100%.

Comparative Example 1 is a combination of stabilized chlorine and stabilized bromine alone, does not contain unreacted bromine ions, has a relatively high free halogen concentration of 0.27 ppm when 25 ppm is added, and free halogen conversion rate compared to total halogen is about 20%.

Condition 9 is a mixture of stabilized chlorine, stabilized bromine-based oxidant, and unreacted bromide ion. When 25 ppm is added, the free halogen concentration is 0.34 ppm, and the free halogen conversion rate compared to the total halogen is about 26%.

Condition 8 has the same bromine content as Condition 9, but because the stabilized bromine content is low and unreacted bromine ions are high, the free halogen concentration is 0.22 ppm when 25 ppm is added, and the free halogen conversion rate compared to the total halogen is low at about 17%.

From the results of Comparative Example 1 and Condition 8, despite the high glass content conversion rate of Comparative Example 1, the water permeability of Condition 9 was higher, showing that unreacted bromide ions contained in the composition of Condition 8 were concentrated in the contaminated layer of the hollow fiber membrane. It was confirmed that it contributed to penetration/exfoliation.

The results of Condition 8 and Condition 9 also show that it is necessary to adjust the stabilized bromine production rate due to organic impurities including microorganisms even when unreacted bromine ions remain at the same bromine content.

Claims (17)

A stabilized halogen-based oxidant composition for sterilizing microorganisms and inhibiting and removing biofilm formation in an aqueous system, comprising a stabilized chlorine-based oxidant, a stabilized bromine-based oxidant, and a bromine ion source. According to paragraph 1,
The stabilized chlorine-based oxidizing agent is a group consisting of chlorosulfamate, chlorinated 5,5-dialkylhydentoin, chlorinated arylsulfonamide, chlorinated succinimide, chlorinated glucoryl, chlorinated cyanuric acid, and bromochlorodimethylhydentoin BCDMH. One or two or more selected from,
The stabilized bromine-based oxidizing agent is one or two or more selected from the group consisting of bromosulfamate and dibromodimethylhydentoin,
A stabilized halogen-based oxidizing agent composition, wherein the bromide ion source is one or more selected from the group consisting of bromide ions, or a mixture thereof. According to claim 1 or 2,
The mixing ratio of the composition is: stabilized chlorine-based oxidizing agent: 1 to 20% by weight, stabilized bromine-based oxidizing agent: 1 to 20% by weight, bromine ion source: 1 to 15% by weight, and the balance consists of water, stabilized halogen Based oxidizing agent composition. According to paragraph 3,
The molar ratio of the stabilized chlorine-based oxidant and the stabilized bromine-based oxidant is 20:1 to 1:20, and the total stabilized halogen-based oxidant (sum of stabilized chlorine-based oxidant and stabilized bromine-based oxidant) and the bromine ion source A stabilized halogen-based oxidizing agent composition, characterized in that the molar ratio is 20:1 to 1:5. According to claim 1 or 2,
A stabilized halogen-based oxidant composition, wherein the aqueous system includes a reverse osmosis membrane, a process with a microporous membrane, or a cooling process. According to clause 5,
The process with the microporous membrane includes an ultrafiltration membrane (UF), a membrane biological reactor (MBR), or a micro filter (Nano Filter, Micro filter), and the cooling process includes a cooling tower, a heat exchanger, or a scrubber. A stabilized halogen-based oxidizing agent composition. A method for producing a stabilized halogen-based oxidizing agent composition for sterilizing microorganisms and inhibiting and removing biofilm formation in an aqueous system,
A first step of preparing solution 1 by adding an alkaline compound and sulfamic acid to water;
A second process of preparing solution 2 by adding a bromine ion source to a hypochlorite (NaOCl) solution;
A third process of preparing solution 3 by mixing solution 2 with solution 1; and
A fourth step of adding a bromine ion source to the solution 3,
A method for producing a stabilized halogen-based oxidizing agent composition, characterized in that the fourth process is carried out under conditions where the pH is maintained at 12 or higher. In clause 7,
A method for producing a stabilized halogen-based oxidizing agent composition, wherein the alkaline compound is one or a mixture of two or more selected from the group consisting of sodium hydroxide (NaOH) or potassium hydroxide (KOH), and the bromine ion source is NaBr. According to paragraph 7 or 8,
The first process is a method for producing a stabilized halogen-based oxidizing agent composition, characterized in that an alkaline compound and sulfamic acid are added so that the pH is at least 12. According to paragraph 7 or 8,
The first process is a method of producing a stabilized halogen-based oxidizing agent composition, characterized in that the temperature of the solution is managed to be 40 ° C. or lower. According to paragraph 7 or 8,
The second process is a method of producing a stabilized halogen-based oxidizing agent composition, characterized in that the temperature of the solution is managed to be 40 ° C. or lower. According to paragraph 7 or 8,
A method for producing a stabilized halogen-based oxidizing agent composition, characterized in that the molar ratio of bromide ions in the second process is adjusted from 1% to 99% of hypochlorous acid to adjust the production rate of hypochlorous acid and hypobromic acid. A method of using a stabilized halogen-based oxidizing agent composition for sterilizing microorganisms and inhibiting and removing biofilm formation in an aqueous system, comprising:
A method of using a stabilized halogen-based oxidizing agent composition, characterized in that the stabilized halogen-based oxidizing agent composition of claim 3 is added to the treated water of an aqueous system so that the concentration of free halogen based on chlorine is 5.0 ppm or less. The method of claim 13, wherein the stabilized halogen-based oxidizing agent composition is added so that the concentration of combined halogen based on chlorine is 100 ppm or less. According to clause 13,
A method of using a stabilized halogen-based oxidizing agent composition, characterized in that the stabilized halogen-based oxidizing agent composition is added so that the concentration of bound halogen is within 20 times the concentration of free halogen. According to clause 13,
In the treated water of an aqueous system that is relatively clean, has few microorganisms, and contains materials vulnerable to free halogens, the stabilized halogen-based oxidizing agent composition is added so that the concentration of free halogens is 0.5 ppm or less. Method of using halogen-based oxidizing agent composition. According to clause 13,
In the treated water of an aqueous system operated at pH 8 or higher, the stabilized halogen-based oxidizing agent composition is added so that the concentration of free halogen is maintained at 2 ppm or less and the concentration of total halogen is maintained at 0.1 ppm or more than the free halogen concentration. A method of using a stabilized halogen-based oxidizing agent composition.