KR102089123B1 - Method for manufacturing water-treatment membrane, water-treatment membrane manufactured by thereof, and water treatment module comprising membrane - Google Patents

Abstract

The present specification provides a method for manufacturing a water treatment separation membrane, a water treatment separation membrane manufactured using the same, and a water treatment module including the water treatment separation membrane.

Description

Method for manufacturing a water treatment separation membrane and a water treatment module comprising the water treatment separation membrane and a water treatment separation membrane produced thereby

The present specification provides a method for manufacturing a water treatment separation membrane, a water treatment separation membrane manufactured using the same, and a water treatment module including the water treatment separation membrane.

Recently, due to severe pollution of the water environment and lack of water, it is an urgent task to develop a new water resource source. Research on pollution of water environment aims to treat high-quality living and industrial water, various sewage and industrial wastewater, and interest in water treatment processes using separators with the advantage of energy saving is increasing. In addition, accelerating environmental regulations are expected to accelerate membrane technology. It is difficult to meet the regulations that are intensified with traditional water treatment processes, but it is expected that the separation membrane technology will be positioned as a leading technology in water treatment in the future because it guarantees excellent treatment efficiency and stable treatment.

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 desalination using a semipermeable membrane that shows water impermeability to salt, but when the high-pressure water in which the salt is dissolved enters one side of the semipermeable membrane, the salt is removed. Comes out on the other side at low pressure.

Specifically, a typical example of such a water treatment separation membrane is a polyamide-based water treatment separation membrane, and a polysulfone layer is formed on a nonwoven fabric to form a microporous support, and the microporous support is m-phenylenediamine (m-Phenylene). Diamine, mPD) is immersed in an aqueous solution to form an mPD layer, which is then immersed or coated in an organic solvent of trimesoyl chloride (TMC) to form a polyamide active layer by interfacial polymerization by contacting the mPD layer with TMC. Being manufactured.

Research into increasing the salt removal rate and permeation flow rate of such a polyamide-based composite membrane has been continuously conducted.

J. Apll. Polym. Sci., V124, P E205-E215

In this specification, a method of manufacturing a water treatment separation membrane and a water treatment separation membrane prepared thereby are described.

One embodiment of the present specification includes preparing a porous support; Applying a solution containing an amine salt to the surface of the porous support; Forming an aqueous solution layer using an aqueous solution containing an amine compound on the surface of the porous support; And contacting the surface of the aqueous solution layer with an organic solution containing an acyl halide compound to form a polyamide active layer.

In addition, an exemplary embodiment of the present specification provides a water treatment separation membrane manufactured by the above-described manufacturing method.

In addition, one embodiment of the present specification provides a water treatment module including at least one or more of the aforementioned water treatment separation membranes.

In addition, one embodiment of the present specification provides a water treatment device including at least one or more of the aforementioned water treatment modules.

The manufacturing method according to the exemplary embodiment of the present specification applies an aqueous solution containing an amine salt to the surface of the porous support before forming the aqueous solution layer, thereby inducing smooth material movement into the pores of the surface of the porous support, and thus a high-speed coating process It is also possible to uniformly apply an amine aqueous solution.

In addition, the water treatment separation membrane prepared by the manufacturing method according to an exemplary embodiment of the present specification is uniformly coated with an amine aqueous solution on the surface of the porous support, and uniformly exhibits excellent salt removal rate and permeate flow rate across the substrate.

1 shows a water treatment separation membrane according to an exemplary embodiment of the present specification.

In this specification, when a member is located "on" another member, this includes not only when one member is in contact with another member but also when another member exists between the two members.

In the present specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless specifically stated otherwise.

Hereinafter, the present specification will be described in more detail.

One embodiment of the present specification, preparing a porous support; Applying a solution containing an amine salt to the surface of the porous support; Forming an aqueous solution layer using an aqueous solution containing an amine compound on the surface of the porous support; And contacting the surface of the aqueous solution layer with an organic solution containing an acyl halide compound to form a polyamide active layer.

In general, the water treatment separation membrane is prepared by forming an interfacially polymerized polyamide layer through continuous application of an aqueous amine solution and an organic solution containing an acyl halide compound. In the case of the slot-coating method with high productivity when applying the solution, the contact time between the substrate and the solution is very short (less than 1/100 of the dip process), and the wettability between the separator and the aqueous solution is poor, so the separator Shows the difference in performance between the lengths of.

In particular, in the case of a low pressure high flow rate product family, a low concentration amine aqueous solution must be applied to prepare a separator having high flow rate characteristics, and for this, more attention is required when applying a slot-coating process.

In the method for manufacturing a water treatment separation membrane developed by the present inventors, in order to satisfy a low pressure high flow rate characteristic within a limited solution contact time, a solution containing an amine salt is applied to a porous support before forming an amine aqueous solution layer, thereby providing a porous support. By improving the wettability of the aqueous amine solution, it is possible to reduce the minimum coating amount.

In addition, when applying the solution, since the amine salt (amine salt) induces a smooth material migration to the pores of the porous support, described in low-concentration, high-speed manufacturing process conditions, unlike glycol compounds that simply increase the humidity of the surface of the porous support A water treatment separation membrane having uniform performance over the entire area can be prepared.

According to an exemplary embodiment of the present specification, the content of the amine salt may be 5 to 20% by weight relative to the solution, more specifically 5 to 15% by weight. If the content of the amine salt (amine salt) is less than 5% by weight, the amine salt (amine salt) in the solution may not be sufficient to induce a smooth mass transfer, and if it exceeds 20% by weight, the amine group remains and the interface During the polymerization reaction, a non-uniform polyamide active layer may be formed.

According to an exemplary embodiment of the present specification, the amine salt is at least one day selected from a compound of camphorsulfonic acid ammonium salt and a compound of bromocamphoursulfonic acid ammonium salt It may be, preferably, triethylammonium camphorsulfonate (TEACSA). According to an exemplary embodiment of the present specification, the solvent of the solution containing the amine salt may be at least one selected from water and alcohol solvents, for example, distilled water, methanol, ethanol, isopropanol, 1-me Oxypropanol, butanol, ethylhexyl alcohol and terpineol, but is not limited thereto.

According to an exemplary embodiment of the present specification, the method of applying a solution containing an amine salt on the porous support can quantitatively apply a coating solution in a closed system such as slot coating or dropping It does not specifically limit if it exists.

At this time, the step of removing the excess solution on the porous support may be additionally performed.

According to the exemplary embodiment of the present specification, as the porous support, a coating layer of a polymer material 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, and polyvinylidene fluoride Ride and the like may be used, but is not necessarily limited to these. Specifically, polysulfone can be used as the polymer material.

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 amine compound and an organic solution containing an acyl halide compound. Specifically, the polyamide active layer is a step of forming an aqueous solution layer containing an amine compound on a porous support; And contacting an organic solution containing an acyl halide compound on the aqueous solution layer containing the amine compound to form a polyamide active layer.

According to an exemplary embodiment of the present specification, the method of forming an aqueous solution layer containing an amine compound on the porous support is not particularly limited, and any method capable of forming an aqueous solution layer on the support can be used without limitation. Specifically, a method of forming an aqueous solution layer containing an amine compound on the porous support may include spraying, coating, dipping, dropping, and the like, preferably by applying an aqueous solution containing an amine compound in a slot-coating method. An aqueous solution layer can be formed.

According to the exemplary embodiment of the present specification, the application speed of the aqueous solution may be 20 m / min or more and 50 m / min or less, and preferably 30 m / min or more and 40 m / min or less. When the application speed of the amine compound is less than 20 m / min, the difference in coating performance may not be large regardless of whether or not the amine salt is coated. If it is more than 50 m / min, the contact time between the porous support and the aqueous solution is short, so the aqueous solution is poor. This can be applied non-uniformly.

At this time, the aqueous layer may be further subjected to the step of removing the aqueous solution containing the excess amine compound, if necessary. The aqueous solution layer formed on the porous support may be non-uniformly distributed when there are too many aqueous solutions present on the support. When the aqueous solution is non-uniformly distributed, an uneven polyamide active layer may be formed by subsequent interfacial polymerization. have. Therefore, it is preferable to remove the excess aqueous solution after forming the aqueous solution layer on the support. Although the removal of the excess aqueous solution is not particularly limited, for example, it may be performed using a sponge, an air knife, nitrogen gas blowing, natural drying, or a compression roll.

According to the exemplary embodiment of the present specification, in the aqueous solution containing the amine compound, the amine compound is not limited as long as it is an amine compound used in the preparation of a water treatment separation membrane, but for example, m-phenylenediamine, p -Phenylenediamine, 1,3,6-benzenetriamine, 4-chloro-1,3-phenylenediamine, 6-chloro-1,3-phenylenediamine, 3-chloro-1,4-phenylene diamine Or a mixture thereof.

According to an exemplary embodiment of the present specification, the content of the amine compound may be 1 to 15% by weight relative to the aqueous amine solution, preferably 1 to 10%. The content of the amine compound is 1% by weight If less than, the reaction with the organic solution containing an acyl halide compound may not be made smoothly, and if it is more than 15% by weight, it may be difficult to stably dissolve the amine compound in the aqueous solution.

According to an exemplary embodiment of the present specification, the method of contacting the organic solution containing the acyl halide compound on the aqueous solution layer is not particularly limited, and any method capable of contacting the organic solution on the aqueous solution layer can be used without limitation. have. Specifically, the method of contacting the organic solution containing an acyl halide compound on the aqueous solution layer may include immersion, spray, coating or coating, and preferably an organic solution containing an acyl halide compound in a slot-coating method. It can be applied to form a polyamide active layer by contacting with an aqueous solution layer.

According to the exemplary embodiment of the present specification, the application speed of the organic solution may be 20 m / min or more and 50 m / min or less, and preferably 30 m / min or more and 40 m / min or less. If the application rate of the organic solution is less than 20m / min, the difference in coating performance may not be large regardless of whether or not the amine salt is coated. If it is more than 50m / min, the contact time between the aqueous solution layer and the organic solution is short, so the wettability is poor The organic solution may be applied non-uniformly.

Upon contact between the aqueous solution layer and the organic solution, an amine compound coated on the surface of the porous support and an acyl halide compound react to generate polyamide by interfacial polymerization, and adsorbed on the microporous support to form a thin film.

According to an exemplary embodiment of the present specification, the acyl halide compound is, but is not limited to, for example, as an aromatic compound having 2 to 3 carboxylic acid halides, trimethoyl chloride, isophthaloyl chloride and It may be a mixture of one or more selected from the group of compounds consisting of terephthaloyl chloride.

According to an exemplary embodiment of the present specification, the organic solvent is an aliphatic hydrocarbon solvent, for example, a hydrophobic liquid that does not mix with water such as freons and hexane, cyclohexane, heptane, alkanes, for example, 5 to 5 carbon atoms 12 alkanes and mixtures thereof, IsoPar (Exxon), IsoPar G (Exxon), ISOL-C (SK Chem), ISOL-G (Exxon), etc. may be used, but are not limited thereto.

Another exemplary embodiment of the present specification provides a water treatment separation membrane manufactured by the above-described manufacturing method.

1 shows a cross-section of a water treatment separation membrane according to an exemplary embodiment of the present specification, a porous support 200 is provided on the nonwoven fabric 100, and a polyamide active layer 300 is formed on the porous support. In the cross section of FIG. 1, the left and right points can be determined based on the horizontal length of the polyamide active layer.

The flat membrane performance deviation between the left end point and the right end point may be less than 5% when the width of the water treatment separation membrane is 350 to 450 nm, and the flat membrane performance deviation between the left and right points may be less than 5%. The performance variation refers to a variation in the electrical conductivity value of the flow rate per unit time and the purified water conductivity at this time after washing for 1 hour at 2000 ppm NaCl aqueous solution and 225 psi conditions. When the performance variation is 5% or more, since the performance is not uniform, the salt removal rate and permeate flow rate of the entire water treatment separation membrane may be reduced.

Another exemplary embodiment of the present specification provides a water treatment module including at least one or more of the aforementioned water treatment separation membranes.

The specific kind 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 above-mentioned reverse osmosis membrane, other configurations and manufacturing methods are not particularly limited, and general means known in this field can be employed without limitation.

Another exemplary embodiment of the present specification provides a water treatment device including at least one or more of the aforementioned water treatment modules. The water treatment device may be usefully used as a water treatment device such as a household / industrial water purification device, a sewage treatment device, a seawater treatment device, or the like, depending on the application.

Hereinafter, examples will be described in detail to specifically describe the present specification. However, the embodiments according to the present specification may be modified in various other forms, and the scope of the present specification is not interpreted to be limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present specification to those skilled in the art.

< Example  1>

In DMF (N, N-dimethylformamide) solution, 18% by weight of polysulfone solid was added and dissolved at 80 to 85 hours for 12 hours or more to obtain a uniform liquid. The solution was cast to a thickness of 150 μm on a nonwoven fabric having a thickness of 95 μm to 100 μm made of polyester. Then, the casted nonwoven fabric was put in water to prepare a porous polysulfone support. At this time, the width of the support was made to 400nm.

On the porous polysulfone support, a solution containing 10% of triethylammonium camphorsulfonate (TEACSA) and water with respect to the total solution was applied in a slot-coating method.

Thereafter, an aqueous solution containing 5% metaphenylenediamine (mPD) with respect to the total aqueous solution was applied on the porous polysulfone support at a rate of 30 m / minm / min by a slot-coating method to form an aqueous solution layer. . Furthermore, the excess aqueous solution generated during application was removed using an air knife.

On the aqueous layer, an organic solution containing 0.3% TMC and an organic solvent (IsoPar G) with respect to the total organic solution was applied at a rate of 30 m / min by a slot-coating method. And, after drying until all the liquid components evaporated at 95, washed with ultrapure distilled water (DIW) to prepare a water treatment separator. At this time, the width of the separation membrane was prepared at 380 nm.

< Example  2>

A water treatment separation membrane was prepared in the same manner as in Example 1, except that the application speed of the mPD aqueous solution and the TMC organic solution was 40 m / min.

< Comparative example  1>

A water treatment separation membrane was prepared in the same manner as in Example 1, except that TEACSA (triethylammonium camphorsulfonate) was not applied.

< Comparative example  2>

A water treatment separation membrane was prepared in the same manner as in Example 2, except that TEACSA (triethylammonium camphorsulfonate) was not applied.

< Experimental example  1-Measurement of permeate flow deviation>

After preparing the water treatment separation membrane, while determining the permeation flow rate, the deviation of the flat membrane performance between the left and right (TD) points of the substrate was confirmed. The performance deviation is a value calculated by calculating the deviation of the electrical conductivity value of the permeated flow rate and the purified water at this time after washing for 1 hour at 2000 ppm NaCl aqueous solution and 225 psi condition.

TWRO, Die shim 250um, Coating width: 305mm coating speed
(m / min) division Wetting agent Coating gap (㎛) Min. requirement of aqueous
solution flow rate (cc / min) avg. Flux deviation of flat sheet (TD) (%) Avg. Salt Rejection (%) Avg. Flux (GFD) 30 Example  One 10% TEACSA 400 378.2 2% 99.71 23.70 600 510.6 4%- 99.65 24.16 800 756.4 4%- 99.66 24.03 Comparative example  One none 400 434.9 10% 99.50 25.32 600 605.1 12%- 99.48 25.94 800 non-coated - - - 40 Example  2 10% TEACSA 400 421.7 4% 99.69 23.65 600 590.5 5%- 99.64 23.71 800 849.4 4%- 99.68 23.92 Comparative example  2 none 400 501.3 15% 99.33 27.28 600 698.8 18%- 99.27 26.87 800 non-coated - - - 10 Comparative example  3 none 800 305.7 3% 99.68 24.01

According to Table 1, in the case of the water treatment separation membranes according to Examples 1 and 2, the flow rate deviation is 4% or less, indicating uniform performance throughout the substrate, but in the case of the water treatment separation membranes according to Comparative Examples 1 and 2, the flow rate deviation is 10 It was confirmed that the deviation of the flat film performance between the left and right (TD) points of the substrate was greater than%.

In addition, it can be seen that the flow rate variation is large when the coating speed is 30 to 40 m / min, compared to when the coating speed is 10 m / min.

100: non-woven fabric
200: porous support
300: polyamide active layer
400: brine
500: purified water
600: concentrated water

Claims (11)

Preparing a porous support;
Applying a solution containing an amine salt to the surface of the porous support;
Forming an aqueous solution layer using an aqueous solution containing an amine compound on the surface of the porous support; And
A method for producing a water treatment separation membrane comprising the step of contacting an organic solution containing an acyl halide compound on the surface of the aqueous solution layer to form a polyamide active layer,
The step of forming the aqueous solution layer includes applying an aqueous solution containing an amine compound on the surface of the porous support at a rate of 20 m / min or more and 50 m / min or less,
The step of forming the polyamide active layer comprises the step of applying an organic solution containing an acyl halide compound on the surface of the aqueous solution layer at a rate of 20 m / min or more and 50 m / min or less . The method according to claim 1,
The content of the amine salt (amine salt) method for producing a water treatment separation membrane, characterized in that 5 to 20% by weight relative to the solution. The method according to claim 1,
The amine salt (amine salt) is a camphorsulfonic acid ammonium salt (Camphoursulfonic acid ammonium salt) -based compound and a bromo camphorsulfonic acid ammonium salt (Bromocamphoursulfonic acid ammonium salt) -based compound selected from at least one water treatment separation membrane manufacturing method. The method according to claim 1,
The amine salt (amine salt) is a method of manufacturing a water treatment separation membrane is triethylammonium camphorsulfonate (TEACSA). delete delete The method according to claim 1,
The content of the amine compound is a method for producing a water treatment separation membrane, characterized in that 1 to 15% by weight relative to the aqueous solution containing the amine compound. delete delete delete delete

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