Specification
Title of the invention: Method of manufacturing a water treatment separation membrane and a water treatment separation membrane manufactured thereby
Technical field
[One]
This application claims the benefit of the filing date of the Korean patent application 10-2018-0006486 filed with the Korean Intellectual Property Office on January 18, 2018, the entire contents of which are incorporated herein.
[2]
The present specification relates to a method of manufacturing a water treatment separation membrane, a water treatment separation membrane manufactured thereby, a water treatment module including a water treatment separation membrane, and a water treatment apparatus including a water treatment module.
Background
[3]
Recently, due to severe pollution of the water quality environment and lack of water, the development of a new water resource source is emerging as an urgent task. Research on water quality environmental pollution aims to treat high-quality domestic and industrial water, various domestic sewage and industrial wastewater, and interest in water treatment processes using separators with the advantage of energy saving is increasing. In addition, the accelerating strengthening of environmental regulations is expected to accelerate the activation of membrane technology. Traditional water treatment processes do not meet the tightening regulations, but separator technology is expected to become a leading technology in the water treatment field in the future as it guarantees excellent treatment efficiency and stable treatment.
[4]
Liquid separation is classified into micro filtration, ultra filtration, nano filtration, reverse osmosis, sedimentation, active transport, and electrodialysis, depending on the pores of the membrane. Among them, the reverse osmosis method refers to a process of desalting by using a semipermeable membrane that permeates water but impermeable to salt. Comes out to the other side with low pressure.
[5]
Specifically, a representative example of such a water treatment separation membrane may be a polyamide-based water treatment separation membrane, and studies on increasing a salt removal rate or permeation flow rate are continuously being conducted.
Detailed description of the invention
Technical challenge
[6]
The present specification is intended to provide a method of manufacturing a water treatment separation membrane, a water treatment separation membrane manufactured thereby, a water treatment module including a water treatment separation membrane, and a water treatment apparatus including a water treatment module.
Means of solving the task
[7]
An exemplary embodiment of the present specification includes the step of contacting an aqueous solution containing free chlorine and halogen ions with a polyamide active layer, and based on the aqueous solution, the content of free chlorine is 150 ppm to 400 ppm, and the halogen ion The content is 150ppm to 400ppm provides a method for producing a water treatment separation membrane.
[8]
In addition, an exemplary embodiment of the present specification provides a water treatment separation membrane manufactured according to the manufacturing method of the water treatment separation membrane described above.
[9]
An exemplary embodiment of the present specification provides a water treatment module including at least one water treatment separation membrane described above.
[10]
In addition, an exemplary embodiment of the present specification provides a water treatment apparatus including one or more of the aforementioned water treatment modules.
Effects of the Invention
[11]
In the water treatment separation membrane according to an exemplary embodiment of the present specification, the salt removal rate, boron removal rate, and/or permeation flow rate of the water treatment separation membrane may be improved by introducing free chlorine and halogen elements to the surface of the polyamide active layer.
Brief description of the drawing
[12]
1 illustrates a water treatment separation membrane according to an exemplary embodiment of the present specification.
[13]
[Explanation of code]
[14]
100: non-woven
[15]
200: porous support layer
[16]
300: polyamide active layer
[17]
400: brine
[18]
500: purified water
[19]
600: concentrated water
Best mode for carrying out the invention
[20]
Hereinafter, the present specification will be described in more detail.
[21]
In the present specification, when a member is positioned "on" another member, this includes not only the case where the member is in contact with the other member, but also the case where another member exists between the two members.
[22]
In the present specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components unless specifically stated to the contrary.
[23]
In the present specification, at% is an element content ratio, and means atomic% used in the art.
[24]
An exemplary embodiment of the present specification includes the step of contacting an aqueous solution containing free chlorine and halogen ions with a polyamide active layer, and based on the aqueous solution, the content of free chlorine is 150 ppm to 400 ppm, and the halogen ion The content is 150ppm to 400ppm provides a method for producing a water treatment separation membrane.
[25]
The water treatment separation membrane is composed of a support layer and an active layer, and among them, a reverse osmosis membrane is a membrane that separates a solvent and a solute by using a reverse osmosis phenomenon. The permeate flow rate and salt removal rate of the water treatment separation membrane are used as important indicators for the performance of the separation membrane, and these performances are greatly influenced by the active layer of the polyamide structure produced by the interfacial polymerization method.
[26]
Accordingly, the present inventors introduced free chlorine and halogen elements onto the active layer in the water treatment separation membrane to increase the salt removal rate and boron removal rate of the separation membrane, or produced a water treatment separation membrane in which the permeate flow rate was improved while maintaining the salt removal rate.
[27]
According to an exemplary embodiment of the present specification, the free chlorine may be derived from hypochlorous acid, chlorous acid, chloric acid, perchloric acid, and ions thereof, and may be used without limitation as long as it is derived from a material capable of generating free chlorine. .
[28]
According to the exemplary embodiment of the present specification, the halogen ion may mean an ion derived from an element of Group 17 of the periodic table excluding chlorine (Cl). That is, it may be ions of the remaining Group 17 elements except for chlorine ions.
[29]
According to the exemplary embodiment of the present specification, the halogen ion may include at least one of bromine ion, iodine ion, and fluorine ion.
[30]
According to an exemplary embodiment of the present specification, the halogen ion is preferably a bromine ion. In particular, in the case of using an aqueous solution containing free chlorine and bromine ions, the salt removal rate and boron removal rate of the water treatment membrane can be improved rather than using an aqueous solution containing only iodine or an aqueous solution containing only free chlorine and iodine ions. I can.
[31]
According to an exemplary embodiment of the present specification, the bromine is sodium bromide, potassium bromide, calcium bromide, magnesium bromide, ammonium bromide, lithium bromide, germanium bromide, cobalt bromide, stromium bromide, cesium bromide, tungsten bromide, bromide 2 It may be derived from copper (Copper(II) bromide), barium bromide and/or hydrogen bromide.
[32]
According to an exemplary embodiment of the present specification, the content of free chlorine may be 150ppm to 400ppm based on the aqueous solution. When the content of the free chlorine satisfies the above range, the boron removal rate of the water treatment separation membrane may be increased.
[33]
According to the exemplary embodiment of the present specification, the content of the halogen ion may be 150ppm to 400ppm based on the aqueous solution. When the content of the halogen ion satisfies the above range, the salt removal rate and the boron removal rate of the water treatment separation membrane may be improved.
[34]
According to the exemplary embodiment of the present specification, the pH of the aqueous solution containing free chlorine and halogen ions may be 4 to 11. By adjusting the concentration of free chlorine and halogen ions according to the pH of the aqueous solution, characteristics of the salt removal rate, boron removal rate, and/or permeation flow rate of the water treatment separation membrane can be prepared for a desired purpose. According to an exemplary embodiment of the present specification, , Contacting the polyamide active layer with the aqueous solution containing the free chlorine and halogen ions may be performed for 5 seconds to 5 minutes, preferably 10 seconds to 1 minute, more preferably 15 seconds to It can be run for 30 seconds. When the contact time is less than 5 seconds , the influence of free chlorine and halogen ions on the polyamide active layer is insignificant, and when the contact time is more than 5 minutes, the residence time in the polyamide active layer is lengthened and the membrane may be contaminated.
[35]
According to an exemplary embodiment of the present specification, immersion, spraying, application or dropping may be selected as the method of contacting, and immersion may be preferably selected.
[36]
According to the exemplary embodiment of the present specification, the method of manufacturing the water treatment separation membrane may further include providing a polyamide active layer on the porous support.
[37]
According to an exemplary embodiment of the present specification, as the porous support, a polymer material coating layer formed on a nonwoven fabric may be used. As the polymer material, for example, polysulfone, polyethersulfone, polycarbonate, polyethylene oxide, polyimide, polyetherimide, polyetheretherketone, polypropylene, polymethylpentene, polymethylchloride, polyvinylidene fluorine Ride, and one or more selected from the group consisting of mixtures thereof may be used, but is not necessarily limited thereto. Specifically, polysulfone may be used as the polymer material.
[38]
According to the exemplary embodiment of the present specification, the polyamide active layer may be formed through interfacial polymerization of an aqueous solution containing an aromatic amine compound and an organic solution containing a polyfunctional acyl halide compound. Specifically, when the aqueous layer containing the aromatic amine compound and the organic solution are brought into contact with each other, the aromatic amine compound coated on the surface of the porous support and the polyfunctional acyl halide compound react to generate polyamide by interfacial polymerization, A thin film is formed by being adsorbed on the porous support. In the above contact method, a polyamide active layer may be formed through a method such as immersion, spraying, or coating.
[39]
According to an exemplary embodiment of the present specification, preparing a porous support, forming a polyamide active layer on the porous support, that is, before applying an aqueous solution containing an aromatic amine compound and an additive on the porous support, TEACSA (triethylammonium camphorsulfonate) may further include applying an additive.
[40]
According to an exemplary embodiment of the present specification, if the aromatic amine compound is an aromatic amine compound used for manufacturing a water treatment separation membrane, the type is not limited, but specific examples include m-phenylenediamine (mPD), p-phenylenediamine. , 1,2,4-benzenetriamine, 4-chloro-1,3-phenylenediamine, 2-chloro-1,4-phenylenediamine, and may be one or more selected from the group consisting of mixtures thereof. . Specifically, m-phenylenediamine (mPD) is preferable.
[41]
According to an exemplary embodiment of the present specification, based on the total weight of the aqueous solution containing the aromatic amine compound, the content of the aromatic amine compound may be 0.1wt% to 15wt%. Preferably it may be 0.1wt% to 10wt%. When the content of the aromatic amine compound satisfies the above range, the reaction with the organic solution containing the polyfunctional acyl halide compound is smoothly performed when the active layer of the water treatment separation membrane is formed, and the aromatic amine compound can be stably dissolved in the aqueous solution. .
[42]
According to the exemplary embodiment of the present specification, the aqueous solution containing the aromatic amine compound may further include a surfactant.
[43]
In the exemplary embodiment of the present specification, the surfactant may be selected from nonionic, cationic, anionic and amphoteric surfactants. According to an exemplary embodiment of the present specification, the surfactant is sodium lauryl sulfate (SLS); Alkyl ether sulfates; Alkyl sulfates; Olefin sulfonates; Alkyl ether carboxylates; Sulfosuccinates; Aromatic sulfonates; Octylphenol ethoxylates; Ethoxylated nonylphenols; Alkyl poly(ethylene oxide); Copolymers of poly(ethylene oxide) and poly(propylene oxide); Alkyl polyglucosides such as octyl glucoside and decyl maltoside; Fatty acid alcohols such as cetyl alcohol, oleyl alcohol, cocamide MEA, cocamide DEA, alkyl hydroxyethyl dimethyl ammonium chloride, cetyltrimethyl ammonium bromide, cetyltrimethyl ammonium chloride, hexadecyltrimethylammonium bromide, and hexadecyltrimethylammonium chloride; And alkyl betaines. Specifically, the surfactant may be SLS, octylphenol ethoxylates, or ethoxylated nonylphenols.
[44]
According to the exemplary embodiment of the present specification, the content of the surfactant may be 0.005wt% to 0.5wt% with respect to the aqueous solution containing the aromatic amine compound.
[45]
According to the exemplary embodiment of the present specification, the step of forming the aqueous solution layer containing the aromatic amine compound is not particularly limited, and any method capable of forming the aqueous solution layer on the porous support may be used without limitation. Specifically, a method of forming an aqueous solution layer containing an aromatic amine compound on the porous support may include spraying, coating, immersion, and dropping.
[46]
According to an exemplary embodiment of the present specification, the aqueous solution layer may be additionally subjected to a step of removing an aqueous solution containing an excess aromatic amine compound, if necessary. The aqueous solution layer formed on the porous support may be unevenly distributed when there are too many aqueous solutions on the support, but when the aqueous solution is non-uniformly distributed, a non-uniform active layer may be formed by subsequent interfacial polymerization. Therefore, it is preferable to remove excess aqueous solution after forming the aqueous solution layer on the support. The removal of the excess aqueous solution is not particularly limited, but may be performed using, for example, a sponge, air knife, nitrogen gas blowing, natural drying, or a compression roll.
[47]
According to an exemplary embodiment of the present specification, the polyfunctional acyl halide compound is not particularly limited, but, for example, as an aromatic compound having 2 to 3 carboxylic acid halides, trimesoyl chloride (TMC), It may be one or more mixtures selected from the group consisting of isophthaloyl chloride, terephthaloyl chloride, and mixtures thereof.
[48]
According to the exemplary embodiment of the present specification, the content of the polyfunctional acyl halide compound may be 0.1 wt% to 0.5 wt% based on the total weight of the organic solution containing the polyfunctional acyl halide compound. When the content of the polyfunctional acyl halide compound satisfies the above range, there is an effect of preventing a decrease in the salt removal rate and permeation flow rate of the finally prepared separator.
[49]
According to an exemplary embodiment of the present specification, it is preferable that the organic solvent does not participate in the interfacial polymerization reaction, and an aliphatic hydrocarbon solvent, for example, isoparaffinic, which is a mixture of alkanes and alkanes having 5 to 12 carbon atoms with freons. It may contain at least one selected from among solvents. Specifically, hexane, heptane, octane, nonane, decane, undecan, dodecane, cyclohexane, IsoPar (Exxon), IsoPar G (Exxon), ISOL-C (SK Chem) and ISOL-G (Exxon), etc. May, but is not limited thereto.
[50]
According to an exemplary embodiment of the present specification, the organic solvent may contain 99.5wt% to 99.9wt% based on the total weight of the organic solution. When the organic solvent satisfies the above range, there is an effect of preventing a decrease in the salt removal rate and permeation flow rate of the finally prepared separator.
[51]
An exemplary embodiment of the present specification provides a water treatment separation membrane manufactured according to the manufacturing method of the water treatment separation membrane described above.
[52]
According to the exemplary embodiment of the present specification, the surface of the water treatment separation membrane may include a bromine element.
[53]
According to the exemplary embodiment of the present specification, the surface of the water treatment separation membrane may contain chlorine element.
[54]
According to an exemplary embodiment of the present specification, the surface of the water treatment separation membrane may include a bromine element but not a chlorine element.
[55]
In the present specification, elemental analysis may be performed through Electron Spectroscopy for Chemical Analysis (ESCA). Specifically, X-Ray Photoelectron Spectroscopy (XPS) may be used.
[56]
According to the exemplary embodiment of the present specification, when elemental analysis on the surface of the water treatment separation membrane is performed, the content of the bromine element may be more than 0 at% and not more than 5 at%. Specifically, it may be 0.88 at% or more and 4.7 at% or less.
[57]
According to an exemplary embodiment of the present specification, when elemental analysis on the surface of the water treatment separation membrane, the content of chlorine element may be greater than 0 at% and less than 1 at%. Specifically, it may be 0.5at% or more and 0.6at% or less.
[58]
According to the exemplary embodiment of the present specification, the surface of the water treatment separation membrane may not contain chlorine element.
[59]
According to the exemplary embodiment of the present specification, the chlorine element may not be detected during elemental analysis on the surface of the water treatment separation membrane due to the difference in free chlorine reactivity according to the pH of the aqueous solution containing free chlorine and bromine ions.
[60]
According to the exemplary embodiment of the present specification, when the chlorine element and the bromine element are detected during elemental analysis on the surface of the water treatment separation membrane, the ratio of the bromine element to the chlorine element (Br/Cl) may be 5 to 10. When the ratio of the bromine element to the chlorine element is less than 5, free chlorine and bromine ions do not affect the surface of the active layer, and when the ratio of the bromine element to the chlorine element is more than 10, a non-uniform film is formed on the surface of the active layer, thereby reducing the permeation flow rate. Can occur.
[61]
According to an exemplary embodiment of the present specification, when the content of chlorine element is more than 0 at% and less than 1 at% in elemental analysis on the surface of the water treatment separation membrane, the ratio of bromine element to chlorine element (Br/Cl) may be 5 to 10.
[62]
According to an exemplary embodiment of the present specification, when the content of chlorine element is more than 0at% and less than 1at%, and the content of bromine element is more than 0at% and less than 5at% when elemental analysis on the surface of the water treatment separation membrane, the ratio of bromine element to chlorine element (Br/Cl) may be 5 to 10.
[63]
According to the exemplary embodiment of the present specification, the ratio of the bromine element to the chlorine element (Br/Cl) may be specifically 6 to 10, more preferably 6.3 to 9.4.
[64]
According to an exemplary embodiment of the present specification, after the step of contacting the polyamide active layer with an aqueous solution containing free chlorine and halogen ions, a step of forming a protective layer by further applying a protective layer composition may be further included. The protective layer composition may include a hydrophilic material in order to increase the permeation flow rate of the water treatment separation membrane, but may be used without limitation as long as it is intended to increase the permeation flow rate or durability of the water treatment separation membrane.
[65]
1 illustrates a water treatment separation membrane according to an exemplary embodiment of the present specification. Specifically, FIG. 1 shows a water treatment separation membrane in which a nonwoven fabric 100, a porous support 200 and a polyamide active layer 300 are sequentially provided, and the brine 400 is introduced into the polyamide active layer 300, The purified water 500 is discharged through the nonwoven fabric 100, and the concentrated water 600 is discharged to the outside without passing through the polyamide active layer 300. However, the water treatment separation membrane according to the exemplary embodiment of the present specification is not limited to the structure of FIG. 1, and an additional configuration may be further included.
[66]
According to the exemplary embodiment of the present specification, the thickness of the water treatment separation membrane may be 100 μm or more and 250 μm or less, and when the thickness of the water treatment separation membrane is 100 μm or more, it is possible to prevent a phenomenon in which the permeation flow rate and the salt removal rate of the separation membrane decrease. There is an effect, and in the case of 250 μm or less, there is an effect of preventing a decrease in the salt removal rate of the separator.
[67]
According to an exemplary embodiment of the present specification, the thickness of the porous support may be 60 μm to 150 μm, but is not limited thereto and may be adjusted as necessary. In addition, the pore size of the porous support is preferably 1 nm to 500 nm, but is not limited thereto.
[68]
According to an exemplary embodiment of the present specification, the water treatment separation membrane may be used as a micro filtration membrane, an ultra filtration membrane, a nano filtration membrane, or a reverse osmosis membrane, and specifically, a reverse osmosis membrane. Can be used.
[69]
Another exemplary embodiment of the present specification provides a water treatment module including at least one water treatment separation membrane described above.
[70]
The specific type of the water treatment module is not particularly limited, and examples thereof include a Plate & Frame module, a Tubular module, a Hollow & Fiber module, or a Spiral wound module. In addition, as long as the water treatment module includes the water treatment separation membrane according to the exemplary embodiment of the present specification described above, other configurations and manufacturing methods are not particularly limited, and general means known in this field may be employed without limitation. have.
[71]
Meanwhile, the water treatment module according to an exemplary embodiment of the present specification has excellent salt removal rate and permeation flow rate, and excellent chemical stability, so that it can be usefully used in water treatment devices such as household/industrial water purification devices, sewage treatment devices, and sea desalination devices. have.
[72]
In addition, an exemplary embodiment of the present specification provides a water treatment apparatus including one or more of the aforementioned water treatment modules.
[73]
Hereinafter, examples will be described in detail to describe the present specification in detail. However, the embodiments according to the present specification may be modified in various forms, and the scope of the present specification is not construed as being limited to the embodiments described below. The embodiments of the present specification are provided to more completely describe the present specification to those of ordinary skill in the art.
Mode for carrying out the invention
[74]

[75]

[76]
18wt% of polysulfone solid was added to DMF (N,N-dimethylformamide) and dissolved at 80°C for 12 hours or longer to obtain a uniform liquid. This solution was cast to a thickness of 150 μm on a nonwoven fabric of 95 μm to 100 μm thick made of polyester. Then, the cast nonwoven fabric was put in water to prepare a porous polysulfone support. Thereafter, an aqueous solution containing 5 wt% of metaphenylenediamine (mPD) based on the total weight of the total aqueous solution was applied on the porous polysulfone support to form an aqueous solution layer. Furthermore, the excess aqueous solution generated during application was removed using an air knife. An organic solution containing 0.3% by weight of trimesoyl chloride (TMC) and an organic solvent (IsoPar G) was coated on the aqueous solution layer based on the total weight of the organic solution. Then, after drying at 95° C. until all of the liquid components evaporated, it was washed with pure water (DIW) to prepare a water treatment separation membrane.
[77]
The prepared water treatment separation membrane was immersed in an aqueous solution containing 150 ppm of free chlorine and 200 ppm of bromine ions for 20 seconds. At this time, the pH of the aqueous solution was adjusted to less than 7. Then, the surface of the separator was dried to prepare a water treatment separator.
[78]

[79]
In Example 1, a water treatment separation membrane was prepared in the same manner as in Example 1, except that an aqueous solution containing 300 ppm of bromine ions was used instead of 200 ppm of bromine ions.
[80]

[81]
In Example 1, a water treatment separation membrane was prepared in the same manner as in Example 1, except that an aqueous solution containing 400 ppm bromine ions was used instead of 200 ppm bromine ions.
[82]

[83]
In Example 1, a water treatment separation membrane was prepared in the same manner as in Example 1, except that the pH of the aqueous solution containing free chlorine and bromine ions was adjusted to more than 7.
[84]

[85]
In Example 2, a water treatment separation membrane was prepared in the same manner as in Example 2, except that the pH of the aqueous solution containing free chlorine and bromine ions was adjusted to more than 7.
[86]

[87]
In Example 3, a water treatment separation membrane was prepared in the same manner as in Example 3, except that the pH of the aqueous solution containing free chlorine and bromine ions was adjusted to more than 7.
[88]

[89]
18wt% of polysulfone solid was added to DMF (N,N-dimethylformamide) and dissolved at 80°C for 12 hours or longer to obtain a uniform liquid. This solution was cast to a thickness of 150 μm on a nonwoven fabric of 95 μm to 100 μm thick made of polyester. Then, the cast nonwoven fabric was put in water to prepare a porous polysulfone support. Thereafter, an aqueous solution containing 5 wt% of metaphenylenediamine (mPD) based on the total weight of the total aqueous solution was applied on the porous polysulfone support to form an aqueous solution layer. Furthermore, the excess aqueous solution generated during application was removed using an air knife. An organic solution containing 0.3% by weight of trimesoyl chloride (TMC) and an organic solvent (IsoPar G) was coated on the aqueous solution layer based on the total weight of the organic solution. Then, after drying at 95° C. until all of the liquid components evaporated, it was washed with ultrapure distilled water (DIW) to prepare a water treatment separation membrane.
[90]

[91]
The water treatment separation membrane prepared in Comparative Example 1 was immersed in an aqueous solution containing 150 ppm of free chlorine for 20 seconds. At this time, the pH of the aqueous solution was adjusted to less than 7. Then, the surface of the separator was dried to prepare a water treatment separator.
[92]

[93]
In Comparative Example 2, a water treatment separation membrane was prepared in the same manner as in Comparative Example 2, except that an aqueous solution containing 300 ppm of free chlorine was used instead of 150 ppm of free chlorine.
[94]

[95]
In Comparative Example 2, a water treatment separation membrane was prepared in the same manner as in Comparative Example 2, except that an aqueous solution containing 400 ppm of free chlorine was used instead of 150 ppm of free chlorine.
[96]

[97]
In Comparative Example 2, a water treatment separation membrane was prepared in the same manner as in Comparative Example 2, except that an aqueous solution containing 150 ppm of bromine ions was used instead of 150 ppm of free chlorine.
[98]

[99]
In Comparative Example 5, a water treatment separation membrane was prepared in the same manner as in Comparative Example 5, except that an aqueous solution containing 300 ppm of bromine ions was used instead of 150 ppm of bromine ions.
[100]

[101]
In Comparative Example 5, a water treatment separation membrane was prepared in the same manner as in Comparative Example 5, except that an aqueous solution containing 400 ppm bromine ions was used instead of 150 ppm bromine ions.
[102]

[103]
In Comparative Example 2, a water treatment separation membrane was prepared in the same manner as in Comparative Example 2, except that the pH of the aqueous solution containing free chlorine was adjusted to more than 7.
[104]

[105]
In Comparative Example 3, a water treatment separation membrane was prepared in the same manner as in Comparative Example 3, except that the pH of the aqueous solution containing free chlorine was adjusted to more than 7.
[106]

[107]
In Comparative Example 4, a water treatment separation membrane was prepared in the same manner as in Comparative Example 4, except that the pH of the aqueous solution containing free chlorine was adjusted to more than 7.
[108]

[109]
In Comparative Example 5, a water treatment separation membrane was prepared in the same manner as in Comparative Example 5, except that the pH of the aqueous solution containing bromine ions was adjusted to more than 7.
[110]

[111]
In Comparative Example 6, a water treatment separation membrane was prepared in the same manner as in Comparative Example 6, except that the pH of the aqueous solution containing bromine ions was adjusted to more than 7.
[112]

[113]
In Comparative Example 7, a water treatment separation membrane was prepared in the same manner as in Comparative Example 7, except that the pH of the aqueous solution containing bromine ions was adjusted to more than 7.
[114]

[115]
The water treatment separation membrane prepared in Comparative Example 1 was immersed for 20 seconds in an aqueous solution containing 75 ppm of free chlorine and 50 ppm of bromine ions. At this time, the pH of the aqueous solution was adjusted to less than 7. Then, the surface of the separator was dried to prepare a water treatment separator.
[116]

[117]
In Comparative Example 14, a water treatment separation membrane was prepared in the same manner as in Comparative Example 14, except that an aqueous solution containing 100 ppm of bromine ions was used instead of 50 ppm of bromine ions.
[118]

[119]
In Comparative Example 15, a water treatment separation membrane was prepared in the same manner as in Comparative Example 15, except that an aqueous solution containing 150 ppm of free chlorine was used instead of 75 ppm of free chlorine.
[120]

[121]
The water treatment separation membrane prepared in Comparative Example 1 was immersed for 20 seconds in an aqueous solution containing 75 ppm of free chlorine and 200 ppm of bromine ions. At this time, the pH of the aqueous solution was adjusted to less than 7. Then, the surface of the separator was dried to prepare a water treatment separator.
[122]

[123]
In Comparative Example 17, a water treatment separation membrane was prepared in the same manner as in Comparative Example 17, except that the pH of the aqueous solution containing free chlorine and bromine ions was adjusted to more than 7.
[124]
In Examples and Comparative Examples, adjusting the pH to more than 7 means adjusting the pH in the range of 9 to 11, and adjusting the pH to less than 7 means adjusting the pH in the range of 4 to 6.
[125]

[126]
For the water treatment separation membranes prepared according to Examples 1 to 6 and Comparative Examples 1 to 18, 32,000 ppm of NaCl aqueous solution and 5 ppm of boronic acid aqueous solution were operated at a flow rate of 800 psi and 4.5 L/min for about 1 hour. After confirming that it is stabilized, the amount of water permeated at 25°C for 10 minutes is measured to calculate the permeation flow rate (flux: GFD (gallon/ft 2 /day)), and salts before and after permeation using a conductivity meter. The results of calculating the salt removal rate (Rejection) and the boron removal rate by analyzing the concentration are shown in Table 1 below.
[127]
In addition, the results of elemental analysis (ESCA) on the surface of the separator are shown in Table 1 below. The elemental analysis was performed using X-ray photoelectron spectroscopy, and the X-ray source was analyzed at 3 or more spots per sample while using Al Ka, and data was collected by scanning at least 20 times per spot.
[128]
[Table 1]
Free chlorine (ppm) Bromine ion (ppm) pH Membrane properties XPS element content (%)
SaltRej.(%) Flux(GFD) BoronRej.(%) Br Cl Br/Cl
Example 1 150 200 <7 99.96 8.32 96.2 3.8 0.6 6.3
Example 2 150 300 <7 99.96 7.87 96.8 4.2 0.6 7.5
Example 3 150 400 <7 99.96 7.31 96.9 4.7 0.5 9.4
Example 4 150 200 7< 99.90 15.97 93.7 0.88 - -
Example 5 150 300 7< 99.92 14.56 94.5 0.98 - -
Example 6 150 400 7< 99.93 13.69 94.8 1.23 - -
Comparative Example 1 - - - 99.86 16.54 91.6 - 0.3 -
Comparative Example 2 150 - <7 99.88 14.33 91.7 - 1.1 -
Comparative Example 3 300 - <7 99.88 13.87 91.7 - 1.4 -
Comparative Example 4 400 - <7 99.86 14.41 91.3 - 1.5 -
Comparative Example 5 - 150 <7 99.85 15.88 90.7 - 0.2 -
Comparative Example 6 - 300 <7 99.83 16.71 91.1 - 0.1 -
Comparative Example 7 - 400 <7 99.88 14.98 90.4 - 0.1 -
Comparative Example 8 150 - 7< 99.84 14.59 91.3 - 0.4 -
Comparative Example 9 300 - 7< 99.83 15.82 91.3 - 0.5 -
Comparative Example 10 400 - 7< 99.83 16.26 91.4 - 0.4 -
Comparative Example 11 - 150 7< 99.85 16.97 91.2 - 0.2 -
Comparative Example 12 - 300 7< 99.83 14.51 91.1 - 0.3 -
Comparative Example 13 - 400 7< 99.86 15.67 91.4 - 0.2 -
Comparative Example 14 75 50 <7 99.89 16.20 92.4 1.2 0.8 1.5
Comparative Example 15 75 100 <7 99.93 11.06 95.2 2.3 0.6 3.83
Comparative Example 16 150 100 <7 99.95 10.81 94.7 2.9 1.0 2.9
Comparative Example 17 75 200 <7 99.93 10.87 93.4 3.2 0.3 10.7
Comparative Example 18 75 200 7< 99.87 15.12 91.7 0.75 - -
[129]
According to the results of Table 1, the water treatment separation membranes according to Examples 1 to 3 have a higher content of free chlorine and bromine ions, compared to the water treatment separation membranes according to Comparative Examples 14 to 16, and the salt removal rate (Salt Rej.) and It can be seen that the boron removal rate (Boron Rej.) increases. In particular, as a result of the surface elemental analysis of the prepared water treatment separation membrane, as a result of the Br/Cl ratio of the water treatment separation membranes of Examples 1 to 3 being 6.3 or more, when the contents of free chlorine and bromine ions are above a certain level, the performance of the separation membrane is affected. You can see that
[130]
Comparing Examples 1 to 6 and Comparative Example 1, when the aqueous solution of free chlorine and bromine ions was treated on the surface of the polyamide active layer according to Examples 1 to 6, it can be seen that the salt removal rate and the boron removal rate were significantly increased. .
[131]
In addition, when comparing Examples 1 to 3 with Comparative Examples 2 to 7, in a section where the pH is less than 7, compared to the case of treating an aqueous solution containing only free chlorine or treating an aqueous solution containing only bromine ions, free chlorine And it can be seen that when the polyamide active layer is treated with an aqueous solution containing all bromine ions, the salt removal rate and the boron removal rate increase.
[132]
Similarly, comparing Examples 4 to 6 with Comparative Examples 8 to 13, compared with the case of treating an aqueous solution containing only free chlorine or treating an aqueous solution containing only bromine ions, in the section where the pH is greater than 7, In the case of treating the polyamide active layer with an aqueous solution containing all of chlorine and bromine ions, it can be seen that the salt removal rate and the boron removal rate increase while maintaining the permeation flow rate (Flux).
[133]
In addition, when comparing Example 1 and Comparative Example 17, it can be seen that in the section where the pH is less than 7, in the case of Comparative Example 17 in which the free chlorine content is less than 150 ppm, the boron removal rate is decreased compared to Example 1 in which the free chlorine content is 150 ppm or more. have.
[134]
Likewise, when comparing Example 4 and Comparative Example 18, it was confirmed that the boron removal rate decreased compared to Example 4 in which the free chlorine content was 150 ppm or more in the case of Comparative Example 18 in which the free chlorine content was less than 150 ppm in the section where the pH was greater than 7. I can.
[135]
According to Examples 1 to 6, it can be seen that the salt removal rate and boron removal rate of the separation membrane are improved as the concentration of bromine ions in the aqueous solution increases, and according to the physical property values ​​of the water treatment separation membranes according to Examples 1 to 6, It can be seen that by adjusting the pH, the permeation flow rate can be improved while reducing the change in the salt removal rate and the boron removal rate.
[136]
As a result, in the water treatment separation membrane according to an exemplary embodiment of the present specification, in the process of manufacturing the water treatment separation membrane, by contacting the surface of the polyamide active layer with an aqueous solution containing a specific content of free chlorine and bromine ions, the salt removal rate of the separation membrane and It can be seen that the boron removal rate can be improved, and the permeation flow rate characteristics can also be adjusted according to the pH control of the aqueous solution.
[137]
Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the claims and detailed description of the invention, and this also belongs to the scope of the invention. .
Claims
[Claim 1]
Including the step of contacting an aqueous solution containing free chlorine and a halogen ion to the polyamide active layer, based on the aqueous solution, the content of the free chlorine is 150ppm to 400ppm, the content of the halogen ion is 150ppm to 400ppm A method of manufacturing a water treatment separation membrane.
[Claim 2]
The method of claim 1, wherein the aqueous solution containing free chlorine and halogen ions has a pH of 4 to 11.
[Claim 3]
The method of claim 1, wherein the step of contacting the polyamide active layer with the aqueous solution containing free chlorine and halogen ions is performed for 5 seconds to 5 minutes.
[Claim 4]
The method of claim 1, wherein the halogen ions include at least one of bromine ions, iodine ions, and fluorine ions.
[Claim 5]
The method of claim 1, wherein the halogen ion is a bromine ion.
[Claim 6]
A water treatment separation membrane prepared according to any one of claims 1 to 5.
[Claim 7]
The water treatment separation membrane according to claim 6, wherein an elemental analysis of the surface of the water treatment separation membrane has a bromine element content of more than 0 at% and less than 5 at%.
[Claim 8]
The water treatment separation membrane according to claim 6, wherein the content of the chlorine element is more than 0 at% and less than 1 at% in elemental analysis on the surface of the water treatment separation membrane.
[Claim 9]
The water treatment separation membrane according to claim 8, wherein the ratio of the bromine element to the chlorine element (Br/Cl) is 5 to 10 in the elemental analysis of the surface of the water treatment separation membrane.
[Claim 10]
The water treatment separation membrane according to claim 6, wherein chlorine element is not detected during elemental analysis on the surface of the water treatment separation membrane.
[Claim 11]
As a water treatment separation membrane with a bromine element content of more than 0 at% and 5 at% or less when elemental analysis on the surface of the water treatment separation membrane, chlorine element is not detected when elemental analysis on the water treatment separation membrane surface is detected, or when chlorine element is detected, the content of chlorine element is 0 at% Water treatment separation membrane that exceeds 1at% and has a ratio of bromine element to chlorine element (Br/Cl) of 5 to 10.
[Claim 12]
A water treatment module comprising at least one water treatment separation membrane according to claim 6.
[Claim 13]
A water treatment module comprising at least one water treatment separation membrane according to claim 11.
[Claim 14]
A water treatment device comprising at least one water treatment module according to claim 12.
[Claim 15]
A water treatment device comprising at least one water treatment module according to claim 13.