KR101843686B1 - Non-oxidizing bactericide agent for separation membrane and method for cleaning the separation membrane using the same - Google Patents

Abstract

The present invention relates to a non-oxidizing fungicide capable of preventing and eliminating biological pollution caused by growth of microorganisms on a surface of a separation membrane and biofilm generated thereby, and a method of sterilizing a separation membrane through a membrane process using the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a non-oxidizing bactericide for a membrane and a method for sterilizing a membrane using the same,

The present invention relates to a non-oxidizing fungicide capable of preventing and eliminating biological pollution caused by growth of microorganisms on a surface of a separation membrane and biofilm generated thereby, and a method of sterilizing a separation membrane during a membrane process using the same.

(Raw water) such as water, industrial water, industrial water, river water, ground water, reservoir water, secondary effluent water for sewage, sewage water and sewage are filtered through a separator to remove suspended matter in the raw water or a material (Hereinafter referred to as " material causing pollution of the membrane ") is blocked by the separator to form a concentration polarization or cake layer and at the same time block the pores and increase the filtration resistance, The inter-membrane pressure difference rises. When the pressure difference increases, the pressure of the inflow line needs to be increased to meet the same production flow rate, and additional energy cost is required.

When a constant intermembrane pressure difference is reached, it is necessary to clean the separation membrane with a cleaning liquid and return to the original membrane filtration flow rate (flux).

The contaminants attached to the membrane are mainly cleaned by a chemical cleaning method. Frequent membrane cleaning lowers plant availability and has a negative effect on membrane lifetime due to the use of highly concentrated strong acids and strong base chemicals when cleaning membranes. Most membrane contaminants such as particles, colloids, and organic matter can easily be removed by chemical cleaning, but biofilm contamination can not be effectively removed. Therefore, there is a need for methods and techniques that can prevent the biofilm from accumulating on the membrane surface in advance.

At present, the RO plant injects an oxidizing agent (sodium hypochlorite (NaOCl)) into the raw water to sterilize the microorganisms and injects a reducing agent (sodium bisulfite) at the front of the membrane process to minimize RO membrane damage by chlorine. . This method has disadvantages in that the bactericidal effect of chlorine is not continuous in the RO membrane and thus does not control regrowth of microorganisms and does not control membrane contamination by chlorine-resistant microorganisms. Therefore, a method of reducing contamination of biofilm on the membrane surface by injecting a sterilizing agent which does not cause RO membrane breakage has been developed.

Dibromo-3-nitrilopropionamide (DBNPA) from Dow Chemical and KV-510 from Kurita are the patents that can be used in this way. In the case of DBNPA, it is impossible to inject during the operation of separation membrane process for drinking water production due to human hazard. In the case of Kurita products, the bactericide composition is not disclosed, but the content of hypochlorous acid is 1 to 10%, which is not free from the fear of membrane damage. In the water treatment RO process, the Kurita product is applied, but it is difficult to apply it to the RO process for sea water desalination, where the salt removal rate of monovalent ions such as sodium ion and chlorine ion is very important.

The following conditions must be satisfied in order to be used for the purpose of reducing the biofilm contamination of the RO process for drinking water for the production of drinking water. (I) human and ecological risks, (ii) sterilization ability, (iii) membrane damage, (iv) membrane exclusion rate, and (v) biofilm removal capability. The inventors of the present invention have developed a sterilizing agent and its composition most suitable to the above standards, and developed a sterilization method for reducing the biofilm on the surface of the membrane by using the RO process.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a membrane separation membrane capable of inhibiting the growth of microorganisms on the surface of the separation membrane, effectively preventing contamination of the biofilm produced by the microorganisms, Non-oxidizing fungicide.

Another object of the present invention is to provide a non-oxidizing fungicide which is harmless to human body and can be used for sterilizing a separation membrane used in a water treatment system such as a drinking water producing process.

It is another object of the present invention to provide a sterilization method capable of sterilizing a separation membrane by injecting the sterilizing agent into a membrane process without the need to perform a separate sterilization process.

According to an embodiment of the present invention, there is provided a non-oxidizing fungicide for a separation membrane, which comprises a compound represented by the following formula (1):

[Chemical Formula 1]

In the present invention, the bactericide may further include a solvent.

In the present invention, the solvent may be at least one selected from the group consisting of water, ethanol, propylene glycol, isopropyl alcohol and dimethyl dicarbonate.

In the present invention, the compound represented by Formula 1 may be contained in an amount of 0.25 to 20 mg / L.

In the present invention, the bactericide may further include at least one selected from the group consisting of soap, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant and chelating agent.

In the present invention, the separation membrane may be a microfiltration membrane (MF), an ultrafiltration membrane (UF), a nanofiltration membrane (NF), or a reverse osmosis membrane (RO).

In the present invention, the separation membrane may be a reverse osmosis membrane made of polyamide.

According to another embodiment of the present invention, there is provided a process for preparing a non-oxidizing fungicide for a separation membrane, which comprises dissolving a compound represented by the following formula (1) in a solvent:

[Chemical Formula 1]

In the present invention, the solvent may be at least one selected from the group consisting of water, ethanol, propylene glycol, isopropyl alcohol and dimethyl dicarbonate.

In the present invention, the compound represented by Formula 1 may be dissolved in a concentration of 0.25 to 20 mg / L.

In the present invention, the solvent may further include at least one selected from the group consisting of soap, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant and chelating agent.

In the present invention, the separation membrane may be a microfiltration membrane (MF), an ultrafiltration membrane (UF), a nanofiltration membrane (NF), or a reverse osmosis membrane (RO).

In the present invention, the separation membrane may be a reverse osmosis membrane made of polyamide.

According to another embodiment of the present invention, there is provided a method for sterilizing a separation membrane comprising contacting a separation membrane with a sterilizing agent containing a compound represented by the following formula (1).

[Chemical Formula 1]

In the present invention, the bactericide may further include a solvent.

In the present invention, the solvent may be at least one selected from the group consisting of water, ethanol, propylene glycol, isopropyl alcohol and dimethyl dicarbonate.

In the present invention, the bactericide may contain the compound represented by the formula (I) at a concentration of 0.25 to 20 mg / L.

In the present invention, the bactericide may further include at least one selected from the group consisting of soap, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant and chelating agent.

In the present invention, the separation membrane may be a microfiltration membrane (MF), an ultrafiltration membrane (UF), a nanofiltration membrane (NF), or a reverse osmosis membrane (RO).

In the present invention, the separation membrane may be a reverse osmosis membrane made of polyamide.

In the present invention, the contacting step may be performed by injecting the sterilizing agent during the reverse osmosis filtration step.

In the present invention, the bactericide may be injected in a shock dosing manner.

The bactericide provided in the present invention can prevent the growth of microorganisms on the surface of the separation membrane without physically or chemically damaging the surface of the separation membrane, and can prevent and reduce contamination due to biofilm. As a result, the lifetime of the separation membrane is prolonged, and the economical efficiency can be secured as the membrane replacement cycle is increased.

In addition, the microbicide provided in the present invention is harmless to the human body and can be used in a separation membrane applied to water treatment such as drinking water production process. Therefore, by injecting the microbicide during the membrane process, contamination due to microbial growth and biofilm It is not necessary to stop the membrane process for sterilization, and the membrane process and the sterilization process can be performed at the same time, which is economical advantage.

FIG. 1 is a photograph of a surface of a reverse osmosis membrane according to each treatment concentration of LAE and chlorine disinfectant by a scanning electron microscope (SEM) in Example 2. FIG.
Fig. 2 shows the result of AFM analysis of the surface of the reverse osmosis membrane according to each treatment of LAE, DBNPA and chlorine disinfectant in Example 3. Fig.
FIG. 3 is a graph showing changes in surface roughness of the reverse osmosis membrane according to each treatment of LAE, DBNPA and chlorine disinfectant in Example 3. FIG.
FIG. 4 shows the results of FT-IR analysis of the chemical composition of the reverse osmosis membrane according to each treatment of LAE and chlorine disinfectant in Example 3. FIG.
FIG. 5 shows changes in the flow rate and salt removal rate of the reverse osmosis membrane according to each treatment of LAE, DBNPA, and chlorine disinfectant in Example 4. FIG.
FIG. 6 is a graph showing the lowest concentration of LAE capable of removing the biofilm formed by the six microorganisms in Example 5. FIG.
FIG. 7 is a graph showing changes in film flow rate according to whether LAE is injected in Example 6. FIG.
8 is a photograph of CLSM photographs of microbial and biofilm changes on the surface of a reverse osmosis membrane according to the treatment of LAE disinfectant in Example 6. Fig.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the following examples are illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

The inventors of the present invention are generally food generally and ethyl -N ^α is used as a food additive in the beverage industry - the lauroyl -L- alginate ^{· HCl (ethyl-N α -dodecanoyl} -L-arginate · HCl) membrane surface It has been found that microbes can be prevented from growing on the membrane or forming a biofilm on the membrane without damaging the membrane surface, and the already formed biofilm can be effectively removed, leading to the present invention.

According to an embodiment of the present invention, there is provided a non-oxidizing fungicide capable of inhibiting the growth of microorganisms on the surface of a separation membrane and preventing or eliminating the formation of biofilm, To a non-oxidizing fungicide for separation membrane.

[Chemical Formula 1]

In the present invention, the compound represented by the formula (1) is a cationic surfactant, and when it is used in the separation membrane process, the growth of microorganisms is inhibited by the sterilizing power and the biofilm produced by the microorganisms can be effectively removed In addition, non-oxidizing fungicides do not cause physical or chemical damage to the membrane surface.

In addition, since the compound represented by the above formula (1) has a long half-life and a wide pH range, it can be used for sterilizing various separating membranes, and can maintain sufficient contact time with microorganisms existing on the membrane surface in a long- Can be effectively suppressed.

Further, in the present invention, the compound represented by the formula (1) can be decomposed into an intermediate product of ethanol, lauric acid and L-arginine, and finally decomposed into urea and CO ₂ and is harmless to the human body. It can also be used for disinfection of membrane used for water treatment.

In the present invention, chemical name (chemical name) is -N ethyl ^α of the compound of Formula 1-a lauroyl -L- alginate ^{· HCl (ethyl-N α -dodecanoyl} -L-arginate · HCl), ethyl laurate Ethyl lauroyl alginate, lauric alginate ethyl ester, lauramide ethyl ester, LAE or lauric alginate.

According to a preferred embodiment of the present invention, the bactericide may be a compound in which the compound represented by Formula 1 is dissolved in an appropriate solvent, and the compound represented by Formula 1 may be contained in an amount of 0.25 to 20 mg / L have. When the content of the compound represented by the formula (1) is less than 0.25 mg / L, sufficient sterilization effect can not be obtained. When the content exceeds 20 mg / L, further improvement effect of the sterilization can not be expected in the separation membrane. .

Here, the type of the solvent is not particularly limited, but specific examples thereof include water, ethanol, propylene glycol, isopropyl alcohol, dimethyl dicarbonate, or a mixture thereof. However, the solvent which can be used in the present invention is not limited to the above-mentioned kinds, and can be appropriately selected from among water-soluble solvents depending on the application of the separation membrane to be sterilized. For example, Water may be used as the solvent when it is used for sterilizing the separation membrane applied to the process.

In addition, the present invention may further include a surfactant, a chelating agent and the like as a substance capable of promoting sterilization and cleaning according to need, for example. Specific examples include anionic surfactants such as soap, higher alcohol sulfuric acid ester salts, alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts and higher alcohol phosphoric acid ester salts; Cationic surfactants such as primary amine salts, secondary amine salts, tertiary amine salts and quaternary ammonium salts; Amphoteric surfactants such as amine oxides such as alkyldimethylamine oxide, alkyldimethylamino fatty acid betaine, and alkylcarboxymethylhydroxyethylimidazoliumbetaine; Polyoxyethylene alkylphenyl ether, polyoxypropylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyethylene glycol alkyl ester, ethylene oxide adduct of polypropylene glycol, propylene oxide adduct of polypropylene glycol, etc. Nonionic surfactants; 1-hydroxyethylidene-1,1-diphosphonic acid, aminotrimethylenephosphonic acid, ethylenediamine tetramethylenephosphonic acid, hexamethylenediamine tetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, nitriloic acid Wherein the salt is at least one selected from the group consisting of NTA, ethylenediaminetetraacetic acid (EDTA), diethylenetriamine acetic acid (DTPA), hydroxyethylethylenediamine triacetic acid (HEDTA), and triethylenetetramine acetic acid (TTHA) A salt, a potassium salt, a lithium salt, an ammonium salt, an amine salt, an alkanolamine salt, and the like.

In addition, in the present invention, the separation membrane to be sterilized as described above is a membrane capable of separating organic pollutants, inorganic pollutants, parasites, bacteria, etc. contained in water and is a porous membrane having many holes It corresponds to a membrane (Porous Membrane). The specific type of separation membrane that can be used with the microbicide of the present invention is not particularly limited and may be selected by selectively passing a specific component such as a microfiltration membrane (MF), an ultrafiltration membrane (UF), a nanofiltration membrane (NF) Can be used without limitation. However, it can be preferably used for sterilizing a reverse osmosis membrane made of a polyamide material.

According to another embodiment of the present invention, there is provided a method for producing a non-oxidizing fungicide for a separation membrane, which comprises dissolving a compound represented by the following formula (1) in a solvent.

[Chemical Formula 1]

In the present invention, the compound represented by Formula 1 may be dissolved in a concentration of 0.25 to 20 mg / L. When the content of the compound represented by the formula (1) is less than 0.25 mg / L, sufficient sterilization effect can not be obtained. When the content exceeds 20 mg / L, the sterilization improving effect can no longer be expected in the separation membrane. It can be a problem.

In the present invention, the type of the solvent is not particularly limited, but specific examples thereof include water, ethanol, propylene glycol, isopropyl alcohol, dimethyl dicarbonate, or a mixture thereof. However, the solvent which can be used in the present invention is not limited to the above-mentioned kind, and it can be appropriately selected in a water-soluble solvent depending on the application of the separation membrane to be sterilized. For example, Water may be used as a solvent when it is used for sterilizing a separation membrane applied to a drinking water production process.

Further, in the present invention, it may further include a step of adding a surfactant, a chelating agent or the like as a substance capable of promoting sterilization and cleaning as required. Specific examples include anionic surfactants such as soap, higher alcohol sulfuric acid ester salts, alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts and higher alcohol phosphoric acid ester salts; Cationic surfactants such as primary amine salts, secondary amine salts, tertiary amine salts and quaternary ammonium salts; Amphoteric surfactants such as amine oxides such as alkyldimethylamine oxide, alkyldimethylamino fatty acid betaine, and alkylcarboxymethylhydroxyethylimidazoliumbetaine; Polyoxyethylene alkylphenyl ether, polyoxypropylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyethylene glycol alkyl ester, ethylene oxide adduct of polypropylene glycol, propylene oxide adduct of polypropylene glycol, etc. Nonionic surfactants; 1-hydroxyethylidene-1,1-diphosphonic acid, aminotrimethylenephosphonic acid, ethylenediamine tetramethylenephosphonic acid, hexamethylenediamine tetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, nitriloic acid Wherein the salt is at least one selected from the group consisting of NTA, ethylenediaminetetraacetic acid (EDTA), diethylenetriamine acetic acid (DTPA), hydroxyethylethylenediamine triacetic acid (HEDTA), and triethylenetetramine acetic acid (TTHA) A salt, a potassium salt, a lithium salt, an ammonium salt, an amine salt, an alkanolamine salt, and the like.

In addition, the present invention is not particularly limited to the specific kind of separation membrane that can be sterilized by the sterilizing agent manufactured as described above, and may be applied to the separation membrane such as a microfiltration membrane (MF), an ultrafiltration membrane (UF), a nanofiltration membrane (NF), a reverse osmosis membrane Any separator that can separate the mixture by selectively passing a specific component can be used without limitation. However, it can be preferably used for sterilizing a reverse osmosis membrane made of a polyamide material.

According to another embodiment of the present invention, there is provided a method for sterilizing a separation membrane comprising contacting a separation membrane with a sterilizing agent containing a compound represented by the following formula (1).

[Chemical Formula 1]

According to a preferred embodiment of the present invention, the sterilizing agent that can be used for sterilizing the separation membrane may be a compound in which the compound represented by Formula 1 is dissolved in an appropriate solvent, wherein the compound represented by Formula 1 is used in an amount of 0.25 to 20 mg / L. ≪ / RTI > When the content of the compound represented by the formula (1) is less than 0.25 mg / L, sufficient sterilization effect can not be obtained. When the content exceeds 20 mg / L, the sterilization improving effect can no longer be expected in the separation membrane. .

Here, the type of the solvent is not particularly limited, but specific examples thereof include water, ethanol, propylene glycol, isopropyl alcohol, dimethyl dicarbonate, or a mixture thereof. However, the solvent which can be used in the present invention is not limited to the above-mentioned kinds, and can be appropriately selected from among water-soluble solvents depending on the application of the separation membrane to be sterilized. For example, Water may be used as the solvent when it is used for sterilizing the separation membrane applied to the process.

In addition, in the present invention, the bactericide is a substance capable of promoting sterilization and washing according to need, and may further include, for example, a surfactant, a chelating agent and the like. Specific examples include anionic surfactants such as soap, higher alcohol sulfuric acid ester salts, alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts and higher alcohol phosphoric acid ester salts; Cationic surfactants such as primary amine salts, secondary amine salts, tertiary amine salts and quaternary ammonium salts; Amphoteric surfactants such as amine oxides such as alkyldimethylamine oxide, alkyldimethylamino fatty acid betaine, and alkylcarboxymethylhydroxyethylimidazoliumbetaine; Polyoxyethylene alkylphenyl ether, polyoxypropylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyethylene glycol alkyl ester, ethylene oxide adduct of polypropylene glycol, propylene oxide adduct of polypropylene glycol, etc. Nonionic surfactants; 1-hydroxyethylidene-1,1-diphosphonic acid, aminotrimethylenephosphonic acid, ethylenediamine tetramethylenephosphonic acid, hexamethylenediamine tetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, nitriloic acid Wherein the salt is at least one selected from the group consisting of NTA, ethylenediaminetetraacetic acid (EDTA), diethylenetriamine acetic acid (DTPA), hydroxyethylethylenediamine triacetic acid (HEDTA), and triethylenetetramine acetic acid (TTHA) A salt, a potassium salt, a lithium salt, an ammonium salt, an amine salt, an alkanolamine salt, and the like.

In the present invention, the specific kind of the separation membrane to be sterilized as described above is not particularly limited, and specific components such as a microfiltration membrane (MF), an ultrafiltration membrane (UF), a nanofiltration membrane (NF), a reverse osmosis membrane Any separator that can selectively pass the mixture can be used without limitation. However, it is preferable to sterilize the reverse osmosis membrane made of a polyamide material.

In the present invention, the method of contacting the bactericide with the separation membrane is not particularly limited, but may be performed by injecting the bactericide into the membrane process using a separation membrane. For example, in the present invention, when the separation membrane to be sterilized is a reverse osmosis membrane, the sterilizing agent according to the present invention may be injected into the reverse osmosis process.

Since the bactericide used in the present invention is harmless to the human body, it is possible to prevent the growth of microorganisms on the surface of the separation membrane by preventing the formation of biofilm or to effectively remove the biofilm formed by injecting the microbicide during the membrane process, It is not necessary to stop the membrane process and perform a separate sterilization process, so that the economical advantage is very large and the process operation is easy.

At this time, the method of injecting the sterilizing agent is not particularly limited, but the sterilizing agent according to the present invention can be injected by the shock dosing method as described above. The shock dosing method is a method in which the sterilizing agent is intermittently injected only for a certain period of time during the operation of the membrane process. For example, when the separation membrane process is performed for 24 hours every day, the sterilizing agent is used for 1 to 10 hours, Hour, or 1 to 5 hours.

Hereinafter, the present invention will be described more specifically by way of specific examples. The following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

Example

[Example 1]

Gram-positive bacteria Staphylococcus aureus , Enterococcus faecalis , and gram-negative bacteria, Pseudomonas aeruginosa PA14, Escherichia coli K12 were inoculated into nutrient medium and incubated at 30 ° C for 24 hours. The cells were inoculated into 96-well plates and cultured for 48 hours at 32 ° C with LAE and DBNPA. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined by a microscope and the results are shown in Table 1.

Type of bacteria LAE DBNPA MIC (mg / L) MBC (mg / L) MIC (mg / L) MBC (mg / L) Gram positive S. aureus 3.91 3.91 125 125 E. faecalis 7.81 15.63 125 125 Gram negative P. aeruginosa PA14 31.25 31.25 62.5 62.5 E. coli K12 15.63 15.63 125 125

As shown in Table 1, it was confirmed that LAE was superior to DBNPA, which was conventionally used as an inert fungicide, in the growth inhibition and killing ability of microorganisms in all four microorganisms.

[Example 2]

LAE and chlorine disinfectant were each dissolved in water to prepare a concentration of 1,000 mg / L, 10,000 mg / L and 100,000 mg / L. The surface of the reverse osmosis membrane made of polyamide was sterilized with the sterilizing agent prepared as described above, and the surface of the membrane surface was photographed by a scanning electron microscope (SEM). The results are shown in FIG.

As shown in FIG. 1, it was confirmed that the reverse osmosis membrane was partially oxidized when the chlorine sterilizing agent was used at a concentration of 10,000 mg / L. When the chlorine sterilizing agent was used at a concentration of 100,000 mg / L, the surface of the reverse osmosis membrane was completely oxidized and flattened . On the other hand, it was confirmed that no change occurred on the surface of the reverse osmosis membrane even when the concentration of LAE bactericide was 100,000 mg / L.

[Example 3]

Each of LAE, chlorine disinfectant and DBNPA was dissolved in water to prepare a solution having a concentration of 100,000 mg / L, and the surface of the reverse osmosis membrane made of polyamide was sterilized for 1 hour. The results are shown in FIG. 3. The results are shown in FIG. 3. The change in chemical composition of the reverse osmosis membrane was measured by FT- IR, and the results are shown in FIG. However, no treatment was performed with the control (control).

As shown in FIG. 2, when the chlorine sterilizing agent was used, it was confirmed that the surface of the reverse osmosis membrane was completely oxidized and the surface of the membrane became flat. On the other hand, when LAE or DPNPA was used, it was confirmed that no change occurred on the surface of the reverse osmosis membrane.

Also, as shown in FIG. 3, the surface roughness of the reverse osmosis membrane was remarkably lowered when the chlorine sterilizing agent was used, but it was confirmed that the surface roughness of the reverse osmosis membrane was not changed when LAE or DPNPA was used.

Also, as shown in FIG. 4, when the chlorine sterilizing agent is used, the peak present in the red line portion disappears. This indicates that the C-N bond in the reverse osmosis membrane of the polyamide material is dissociated, and the chemical composition of the reverse osmosis membrane is changed by the chlorine sterilizing agent. However, it was confirmed that LAE or DBNPA did not change the chemical composition of the reverse osmosis membrane.

As a result, it can be seen that the bactericide according to the present invention does not physically or chemically damage the surface of the membrane.

[Example 4]

Each of LAE, chlorine disinfectant and DBNPA was dissolved in water to prepare a concentration of 1,000 mg / L, 10,000 mg / L and 100,000 mg / L, and the surface of the reverse osmosis membrane made of polyamide material was sterilized for 1 hour. The changes in the flow rate and salt removal rate of the reverse osmosis membrane after each treatment are shown graphically in FIG. However, no treatment was performed with the control (control).

As shown in FIG. 5, when the chlorine sterilizing agent was used, the reverse osmosis membrane flow rate was increased and the salt removal rate was decreased as the concentration was increased. However, when LAE or DBNPA was used, the reverse osmosis membrane flow rate It was confirmed that there was no change in the salt removal rate.

As a result, it can be seen that the bactericide according to the present invention does not physically or chemically damage the surface of the membrane.

[Example 5]

Staphylococcus aureus ATCC6538, Pseudomonas litoralis KCTC23093, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853, Escherichia coli strain K12 and Pseudomonas The lowest concentration of LAE capable of removing the biofilm formed by the six microorganisms of the aeruginosa strain PA14 was confirmed, and the results are shown in FIG.

As shown in FIG. 6, it was confirmed that when the LAE was used at a low concentration of about 31.3 mg / L, the biofilm formed by the six microorganisms could be removed. In the case of Staphylococcus aureus ATCC 6538, LAE was 3.9 mg / L The formation of the biofilm was inhibited even at a very low concentration of.

As a result, it can be seen that the microbicide according to the present invention can effectively remove the biofilm existing on the surface of the separation membrane even at a very low concentration.

[Example 6]

And was operated for 6 months using seawater having a turbidity of about 0.01 to 1.00 and a total organic carbon (TOC) of 1.0 mg / L to 5.0 mg / L. LAE was injected at a concentration of 0.5 to 5 mg / L for 1 to 5 hours per day on average. The results of the flow rate change through the membrane measured during the operation for 6 months are shown in FIG. FIG. 8 shows the result of photographing the surface of the reverse osmosis membrane by CLSM (Confocal Laser Scanning Microscopy) after the completion of the experiment, and the thickness and density of the biofilm formed on the surface of the membrane are shown in Table 2 below. However, no injection was made as a control group.

division Control group LAE processing Biofilm Thickness (㎛) 24.9 11.6 Biofilm density (㎛ ³ / ㎛ ² ) 24.7 8.1

As shown in FIG. 7, when the LAE was injected, it was confirmed that the flow rate was maintained higher than that of the control group. This implies that LAE injection can effectively control the flow reduction due to biofilm formation.

In FIG. 8, green fluorescence is a living microorganism, red fluorescence is a dead microorganism, and yellow fluorescence is a combination of green fluorescence and red fluorescence. In a control group without any treatment, microorganisms grow on the reverse osmosis membrane surface, (A), it was confirmed that when LAE was injected, the microorganisms on the reverse osmosis membrane were gradually killed and the biofilm was also removed (b).

As shown in Table 2, when the LAE was injected, the thickness and density of the biofilm formed on the surface of the reverse osmosis membrane were significantly reduced compared to the control.

Accordingly, the microbicide according to the present invention can kill the microbes existing on the surface of the separation membrane, effectively remove the biofilm formed by the microbes, and when actually operating the microbial- It is possible to obtain a sufficient microbial growth inhibition and biofilm removal effect even if the concentration of the microbicide is used at a very low concentration and further that the microbicide according to the present invention is harmless to the human body and can be used directly in the reverse osmosis process for producing drinking water from seawater have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It is to be understood that the invention may be practiced within the scope of the appended claims.

Claims (11)

A non-oxidizing fungicide for a separation membrane characterized by containing a compound represented by the following formula (1) in an amount of 0.25 mg / L to 20 mg / L,
Wherein the separation membrane is a reverse osmosis membrane made of polyamide, a non-oxidizing fungicide for separation membrane:
[Chemical Formula 1]

The method according to claim 1,
Wherein the bactericide further comprises a solvent. 3. The method of claim 2,
Wherein the solvent is at least one selected from the group consisting of water, ethanol, propylene glycol, isopropyl alcohol and dimethyl dicarbonate. The method according to claim 1,
Wherein the bactericide further comprises at least one member selected from the group consisting of soap, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant and chelating agent. And dissolving the compound represented by the formula (1) in a solvent in an amount of 0.25 mg / L to 20 mg / L,
Wherein the separation membrane is a reverse osmosis membrane made of a polyamide material,
[Chemical Formula 1]

6. The method of claim 5,
Wherein the solvent is at least one selected from the group consisting of water, ethanol, propylene glycol, isopropyl alcohol and dimethyl dicarbonate. 6. The method of claim 5,
Further comprising a step of further dissolving at least one selected from the group consisting of soap, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant and chelating agent in the solvent, to prepare a non-oxidizing bactericide for separation membrane Way. And contacting the surface of the separation membrane with a bactericide containing the compound represented by the following formula (1) in an amount of 0.25 mg / L to 20 mg / L,
Wherein the separation membrane is a reverse osmosis membrane made of polyamide,
[Chemical Formula 1]

9. The method of claim 8,
Wherein the sterilizing agent further comprises a solvent. 10. The method of claim 9,
Wherein the solvent is at least one selected from the group consisting of water, ethanol, propylene glycol, isopropyl alcohol and dimethyl dicarbonate. 9. The method of claim 8,
Wherein the bactericide further comprises at least one member selected from the group consisting of soap, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant and chelating agent.

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