KR20170021578A

KR20170021578A - Method for manufacturing water-treatment membrane, water-treatment membrane manufactured by thereof, and water treatment module comprising membrane

Info

Publication number: KR20170021578A
Application number: KR1020150116143A
Authority: KR
Inventors: 유혜인; 전병호; 엄영식; 신정규; 최형삼
Original assignee: 주식회사 엘지화학
Priority date: 2015-08-18
Filing date: 2015-08-18
Publication date: 2017-02-28
Also published as: KR102002364B1

Abstract

The present invention relates to a method for manufacturing a water treatment membrane, a water treatment membrane manufactured using the same, and a water treatment module including a membrane.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment module including a water treatment membrane, a water treatment membrane, a water treatment membrane, a water treatment membrane, a water treatment membrane, a water treatment membrane, a water treatment membrane,

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

Due to the serious pollution and water shortage in recent years, it is urgent to develop new water resources. Studies on the pollution of water quality are aiming at the treatment of high quality living and industrial water, various domestic sewage and industrial wastewater, and interest in the water treatment process using the separation membrane having the advantage of energy saving is increasing. In addition, the accelerated enforcement of environmental regulations is expected to accelerate the activation of membrane technology. Conventional water treatment process is difficult to meet the regulations that are strengthened, but membrane technology is expected to become a leading technology in the water treatment field because it guarantees excellent treatment efficiency and stable treatment.

Liquid separation is classified into micro filtration, ultrafiltration, 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 using a semi-permeable membrane which is permeable to water but impermeable to salt. When high-pressure water containing salt is introduced into one side of the semipermeable membrane, Will come out on the other side with low pressure.

In recent years, approximately 1 billion gal / day of water has been subjected to dechlorination through the reverse osmosis process. Since the first reverse osmosis process using the reverse osmosis in the 1930s was announced, many of the semi- Research was conducted. Among them, cellulose-based asymmetric membranes and polyamide-based composite membranes are the main commercial successes. The cellulosic membranes developed at the beginning of the reverse osmosis membrane have various drawbacks such as narrow operating pH range, high temperature deformation, high cost of operation due to high pressure, and vulnerability to microorganisms Is a rarely used trend.

On the other hand, the polyamide-based composite membrane is formed by forming a polysulfone layer on a nonwoven fabric to form a microporous support, and immersing the microporous support in an aqueous solution of m-phenylenediamine (hereinafter referred to as mPD) And then the resultant is immersed or coated in an organic solution of triMesoyl Chloride (hereinafter referred to as TMC) to form a polyamide active layer by interfacial polymerization with the mPD layer in contact with TMC. By contacting the nonpolar solution with the polar solution, the polymerization takes place at the interface only and forms a very thin polyamide layer. The polyamide-based composite membrane has higher stability against pH change, can operate at lower pressure, and has a higher salt removal rate than conventional cellulose-based asymmetric membranes, and is currently a mainstream of water treatment membranes.

Studies on increasing the salt removal rate and permeate flow rate of such polyamide composite membranes have been continuously carried out.

Korean Patent Publication No. 10-1999-0019008

The present invention provides a method for manufacturing a water treatment membrane capable of improving performance through a simple process and a water treatment membrane manufactured using the same.

One embodiment of the present disclosure relates to a method of preparing a porous support, comprising: preparing a porous support; Forming a polyamide active layer on the porous support using interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound; And introducing a solution containing a carbodiimide compound onto the surface of the polyamide active layer.

In addition, one embodiment of the present invention provides a water treatment separation membrane manufactured using the method for producing a water treatment separation membrane.

In addition, one embodiment of the present disclosure provides a water treatment module comprising at least one water treatment separation membrane.

The method of manufacturing the water treatment separation membrane according to one embodiment of the present invention can improve the performance of the water treatment separation membrane by modifying the surface of the polyamide active layer by adding a simple process. Specifically, the water treatment separation membrane produced according to the method of manufacturing a water treatment separation membrane according to one embodiment of the present invention exhibits an excellent salt removal ratio.

The method for producing a water treatment separator according to one embodiment of the present invention can be simply washed with water to remove the solution containing the carbodiimide compound after the reaction, thereby reducing the post-treatment cost.

When a member is referred to herein as being "on " another member, it includes not only a member in contact with another member but also another member between the two members.

Whenever a component is referred to as "comprising ", it is to be understood that the component may include other components as well, without departing from the scope of the present invention.

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

The inventors of the present invention have completed studies for improving the water removal membrane salt removal rate and permeation flow rate including the polyamide-based active layer, and completed the process for producing the water treatment separation membrane. Specifically, in the method for producing a water treatment separation membrane according to one embodiment of the present invention, a solution containing a carbodiimide compound is introduced into the surface of a polyamide active layer to modify the surface of the polyamide active layer to form a water treatment separation membrane Can be manufactured.

The introduction of the solution containing the carbodiimide compound may mean that the solution containing the carbodiimide compound is brought into contact with the surface of the polyamide active layer. The introduction of the solution containing the carbodiimide compound may be carried out by immersing the polyamide active layer in a solution containing the carbodiimide compound or by adding the carbodiimide compound on the polyamide active layer To the solution. However, if the solution containing the carbodiimide compound is capable of reacting with the surface of the polyamide active layer, the solution containing the carbodiimide compound may be introduced by various methods Lt; / RTI >

According to an embodiment of the present invention, the step of forming the polyamide active layer may include a step of drying without washing after the interfacial polymerization. Specifically, the polyamide active layer formed through the interfacial polymerization may be dried without washing to leave a carboxyl group on the surface of the polyamide active layer and then induce amide bond with the carbodiimide compound have. In addition, the carbodiimide compound may react with the carboxyl group remaining on the surface of the polyamide active layer to increase the crosslinking ratio of the polyamide active layer. Through such a process, the surface of the polyamide active layer is modified to achieve a high salt removal rate.

According to one embodiment of the present invention, the carbodiimide compound may be graft-polymerized to the polyamide active layer.

According to one embodiment of the present invention, the carbodiimide compound may be represented by the following formula (1) or (2).

[Chemical Formula 1]

(2)

In the above formulas (1) and (2)

R1, R1 ', R2', R3 and R4 are each independently hydrogen; A substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; Or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms,

R2 is a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms; Or a substituted or unsubstituted arylene group having 6 to 40 carbon atoms.

In particular, according to one embodiment of the present disclosure, there is provided a process for preparing N, N'-dicyclohexylcarbodiimide (DCC), N, N'-dicyclohexylcarbodiimide (EDC) N'-diisopropylcarbodiimide (DIC) and N, N'-bis (2-methylphenyl) carbodiimide (BPC). However, the present invention is not limited thereto, and a compound including a carbodiimide other than the exemplified compound may be applied.

According to one embodiment of the present invention, the solution containing the carbodiimide-based compound may contain the carbodiimide-based compound in an amount of 0.0001 wt% to 0.5 wt%. Specifically, according to one embodiment of the present invention, the solution containing the carbodiimide-based compound may contain 0.0001 wt% or more and 0.5 wt% or less, or 0.0002 wt% or more and 0.5 wt% or less of the carbodiimide compound . According to an embodiment of the present invention, the solution containing the carbodiimide compound may contain 0.001 wt% or more and 0.5 wt% or 0.002 wt% or more and 0.2 wt% or less of the carbodiimide compound have. More specifically, according to one embodiment of the present invention, the solution containing the carbodiimide-based compound may contain 0.002 wt% or more and 0.1 wt% or less of the carbodiimide-based compound.

If the content of the carbodiimide compound is less than 0.0001 wt%, there is a problem that the performance of the water treatment separator can not be improved. When the content of the carbodiimide compound is more than 0.5 wt%, it may remain in the solvent and not be dissolved in the solvent, resulting in a decrease in performance of the polyamide active layer.

According to one embodiment of the present invention, the step of introducing the solution containing the carbodiimide-based compound is a step of bringing the solution containing the carbodiimide compound into the surface of the polyamide active layer for at least 1 second but no more than 150 seconds And then washing with water. Specifically, according to an embodiment of the present invention, the step of introducing the solution containing the carbodiimide-based compound may include supplying the solution containing the carbodiimide-based compound to the surface of the polyamide active layer for at least 10 seconds and at least 120 Sec or less and washing with water. More specifically, according to one embodiment of the present invention, the step of introducing the solution containing the carbodiimide-based compound comprises introducing a solution containing the carbodiimide-based compound onto the surface of the polyamide active layer for 10 seconds or more 60 seconds or less, and then washing with water.

When the residence time exceeds 120 seconds, there is a problem in that the process time is prolonged to cause a cost problem, and further, there is a problem that it can not contribute to the improvement of the performance of the polyamide active layer.

According to one embodiment of the present invention, the solution containing the carbodiimide compound may further include an amine group-containing compound.

The amine group-containing compound may react with unreacted -COCl remaining in the polyamide active layer to increase the crosslinking ratio of the polyamide active layer to increase the salt removal ratio of the water treatment separator. Specifically, when the amine group-containing compound is applied together with the carbodiimide-based compound, the performance of the water treatment separation membrane can be further improved. However, when the amine group-containing compound is applied without the carbodiimide compound, the performance of the prepared water treatment separator may be deteriorated.

According to one embodiment of the present invention, the amine group-containing compound may be represented by the following general formula (3).

(3)

The method of claim 3,

R5 to R12 each independently represent hydrogen; A substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; Or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms,

m is an integer of 1 to 10, n is an integer of 1 to 15, and o is an integer of 1 to 10.

According to one embodiment of the present disclosure, each of R5 to R12 independently represents hydrogen; Or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.

According to one embodiment of the present disclosure, R6, R9, R10 and R11 may be hydrogen.

According to one embodiment of the present disclosure, R5, R7, R8 and R12 may be a methyl group.

According to one embodiment of the present invention, the solution containing the carbodiimide-based compound may contain 0.001 wt% or more and 0.05 wt% or less of the compound containing the amine group. Specifically, according to one embodiment of the present invention, the solution containing the carbodiimide-based compound may contain 0.005 wt% or more and 0.02 wt% or less of the compound containing the amine group.

According to one embodiment of the present invention, the solution containing the carbodiimide-based compound may contain the carbodiimide-based compound and the amine-containing compound at a weight ratio of 1: 2 to 1: 100. Specifically, according to one embodiment of the present invention, the solution containing the carbodiimide-based compound contains the carbodiimide-based compound and the amine-containing compound at a weight ratio of 1: 5 to 1:50 .

According to one embodiment of the present invention, the porous support may be formed with a coating layer of a polymer material on a nonwoven fabric. Examples of the polymeric material include polymeric materials such as polysulfone, polyethersulfone, polycarbonate, polyethylene oxide, polyimide, polyetherimide, polyetheretherketone, polypropylene, polymethylpentene, polymethyl chloride and polyvinylidene fluoride Rides, and the like may be used, but the present invention is not limited thereto. Specifically, polysulfone may be used as the polymer material.

According to one embodiment of the present invention, the polyamide active layer can be formed through an 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 formed by forming an aqueous solution layer containing an amine compound on a porous support; And contacting the organic solvent containing an organic solvent with an acyl halide compound on an aqueous solution layer containing the amine compound to form a polyamide active layer.

When the aqueous solution containing the amine compound and the organic solution are brought into contact with each other, an amine compound coated on the surface of the porous support reacts with the acyl halide compound to form polyamide by interfacial polymerization, and the polyamide is adsorbed on the microporous support, . In the contact method, a polyamide active layer may be formed by a method such as dipping, spraying, or coating.

According to one embodiment of the present invention, a method of forming an aqueous solution layer containing an amine compound on the porous support is not particularly limited, and any method can be used as long as it is capable of forming an aqueous solution layer on a support. Specifically, a method of forming an aqueous solution layer containing an amine compound on the porous support includes spraying, coating, dipping, dropping, and the like.

At this time, the aqueous solution layer may be further subjected to a step of removing an aqueous solution containing an excess of the amine compound, if necessary. The aqueous solution layer formed on the porous support may be unevenly distributed when the aqueous solution present on the support is excessively large. If the aqueous solution is unevenly distributed, a non-uniform 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. The removal of the excess aqueous solution is not particularly limited, but can be performed using, for example, a sponge, an air knife, nitrogen gas blowing, natural drying, or a compression roll.

According to one embodiment of the present invention, 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 specific examples include m-phenylenediamine, p - phenylenediamine, 1,3,6-benzenetriamine, 4-chloro-1,3-phenylenediamine, 6-chloro-1,3-phenylenediamine, 3- Or a mixture thereof.

According to one embodiment of the present disclosure, the acyl halide compounds include, but are not limited to, for example, aromatic compounds having 2 to 3 carboxylic acid halides, such as trimethoyl chloride, isophthaloyl chlorides, Terephthaloyl chloride, and mixtures of at least one compound selected from the group consisting of terephthaloyl chloride.

According to one embodiment of the present invention, the organic solvent may be an aliphatic hydrocarbon solvent, for example, a hydrophobic liquid such as Freons and a water-immiscible hydrophobic liquid such as hexane, cyclohexane, heptane or alkane having 5 to 12 carbon atoms, An alkane having 5 to 12 carbon atoms and mixtures thereof such as IsoPar (Exxon), ISOL-C (SK Chem), and ISOL-G (Exxon) may be used.

According to one embodiment of the present invention, the water treatment separation membrane can be used as a microfiltration membrane, an ultrafiltration membrane, a nano filtration membrane or a reverse osmosis membrane, Can be used.

One embodiment of the present invention provides a water treatment separation membrane produced using the method for producing the water treatment separation membrane.

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 one embodiment of the present invention, other structures and manufacturing methods are not particularly limited and general means known in the art can be employed without limitation have.

On the other hand, the water treatment module according to one embodiment of the present invention has excellent salt removal rate and permeation flow rate, and is excellent in chemical stability, and thus can be used for water treatment devices such as household / industrial water purification devices, sewage treatment devices, have.

Hereinafter, the present invention will be described in detail by way of examples with reference to the drawings. However, the embodiments according to the present disclosure can be modified in various other forms, and the scope of the present specification is not construed as being limited to the embodiments described below. Embodiments of the present disclosure are provided to more fully describe the present disclosure to those of ordinary skill in the art.

[ Comparative Example One]

18% by weight of polysulfone solid was put into a solution of DMF (N, N-dimethylformamide) and melted at 80 ° C to 85 ° C for over 12 hours to obtain a uniform liquid phase. This solution was cast to a thickness of 150 탆 on a nonwoven fabric of 95 탆 to 100 탆 thickness made of polyester. The cast nonwoven fabric was then placed in water to form a porous polysulfone support.

The porous polysulfone support prepared by the above method was immersed in an aqueous solution containing 2 wt% of metaphenylenediamine (mPD) for 2 minutes and then taken out. The excess aqueous solution on the support was removed using a 25 psi roller, And dried for 1 minute.

Then, the support was immersed in an organic solution of 0.1 wt% trimesoyl chloride (TMC) using ISOL-C (SK Chem) solvent for 1 minute, and then taken out and dried in an oven at 60 ° C for 10 minutes.

Then, the membrane was rinsed with 0.2 wt% sodium carbonate aqueous solution at room temperature for 2 hours or more, and then washed with distilled water to prepare a water treatment separation membrane having a 200 nm thick polyamide active layer.

[ Example One]

18% by weight of polysulfone solid was added to DMF (N, N-dimethylformamide) solution, and the mixture was melted at 80 ° C to 85 ° C for 12 hours or more to obtain a uniform liquid phase. This solution was cast to a thickness of 150 탆 on a nonwoven fabric of 95 탆 to 100 탆 thickness made of polyester. The cast nonwoven fabric was then placed in water to form a porous polysulfone support.

The porous polysulfone support prepared by the above method was immersed in an aqueous solution containing 2 wt% of metaphenylenediamine for 2 minutes and then taken out. The excess aqueous solution on the support was removed using a 25 psi roller, dried at room temperature for 1 minute Respectively.

Then, the support was immersed in an organic solution of 0.1 wt% of trimesoyl chloride (TMC) using an ISOL-C (SK Chem) solvent for 1 minute and then taken out and dried in an oven at 60 ° C for 10 minutes to obtain a 200 nm- Thereby forming an active layer.

The polyamide active layer was not washed separately and an aqueous solution of 0.2 wt% N- (3-dimethylaminopropyl) -N'-ethyl carbodiimide (EDC) was applied to the polyamide active layer, And then washed to prepare a water treatment membrane.

[ Example 2]

A water treatment separation membrane was prepared in the same manner as in Example 1 except that an aqueous solution having an EDC concentration of 0.002 wt% was used.

[ Example 3]

A water treatment separation membrane was prepared in the same manner as in Example 1, except that 0.002 wt% of EDC aqueous solution was applied to the polyamide active layer and stood for 120 seconds and washed.

[ Example 4]

A water treatment separation membrane was prepared in the same manner as in Example 1, except that an aqueous solution having an EDC content of 0.002 wt% and a Jeffanime content of 0.01 wt% was applied to the polyamide active layer, and the mixture was allowed to stand for 10 seconds and then washed.

[ Example 5]

A water treatment membrane was prepared in the same manner as in Example 1, except that an aqueous solution having an EDC content of 0.0002 wt% and a Jeffanime content of 0.01 wt% was applied to the polyamide active layer, and the mixture was allowed to stand for 10 seconds and then washed.

[ Example 6]

A water treatment separation membrane was prepared in the same manner as in Example 1, except that an aqueous solution having 0.002 wt% of EDC and 0.01 wt% of Jeffanime was applied to the polyamide active layer, and the solution was allowed to stand for 120 seconds and then washed.

[ Example 7]

A water treatment separation membrane was prepared in the same manner as in Example 1, except that an aqueous solution having an EDC content of 0.0002 wt% and a Jeffanime content of 0.01 wt% was applied to the polyamide active layer, and the mixture was allowed to stand for 120 seconds and then washed.

[ Comparative Example 2]

A water treatment membrane was prepared in the same manner as in Example 1, except that an aqueous solution of 0.01 wt% of Jeffanime was applied to the polyamide active layer without EDC, and the solution was allowed to stand for 10 seconds and then washed.

The salt removal ratio (%) and the permeation flow rate (GFD) of the water treatment membranes prepared according to the Comparative Examples and Examples are shown in Table 1 below.

Salt removal rate
(%) Permeate flow rate
(GFD) Comparative Example 1 99.64 15.77 Comparative Example 2 99.62 12.28 Example 1 99.75 14.90 Example 2 99.87 16.00 Example 3 99.72 13.99 Example 4 99.84 12.31 Example 5 99.90 11.13 Example 6 99.83 11.62 Example 7 99.86 10.73

According to Table 1, it can be seen that the water treatment membranes according to the embodiments exhibit a higher salt removal rate and / or permeation flow rate than the comparative example.

Claims

Preparing a porous support;
Forming a polyamide active layer on the porous support using interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound; And
And introducing a solution containing a carbodiimide compound onto the surface of the polyamide active layer.

The method according to claim 1,
Wherein the step of forming the polyamide active layer comprises a step of drying without washing after the interfacial polymerization.

The method according to claim 1,
Wherein the carbodiimide compound is graft-polymerized to the polyamide active layer.

The method according to claim 1,
Wherein the carbodiimide compound is represented by the following Chemical Formula 1 or Chemical Formula 2:
[Chemical Formula 1]

(2)

In the above formulas (1) and (2)
R1, R1 ', R2', R3 and R4 are each independently hydrogen; A substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; Or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms,
R2 is a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms; Or a substituted or unsubstituted arylene group having 6 to 40 carbon atoms.

The method of claim 4,
The carbodiimide compound may be at least one selected from the group consisting of N- (3-dimethylaminopropyl) -N'-ethylcarbodiimide (EDC), N, N'-dicyclohexylcarbodiimide (DCC) (DIC), and N, N'-bis (2-methylphenyl) carbodiimide (BPC).

The method according to claim 1,
Wherein the solution containing the carbodiimide compound contains 0.0001 wt% or more and 0.5 wt% or less of the carbodiimide compound.

The method according to claim 1,
The step of introducing the solution containing the carbodiimide compound includes a step of retaining the solution containing the carbodiimide compound on the surface of the polyamide active layer for at least 1 second but not longer than 150 seconds and then washing with water Wherein the water-treating separator is a water-treating separator.

The method according to claim 1,
Wherein the solution containing the carbodiimide compound further comprises an amine group-containing compound.

The method of claim 8,
Wherein the amine group-containing compound is represented by the following general formula (3): < EMI ID =
(3)

The method of claim 2,
R5 to R12 each independently represent hydrogen; A substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; Or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms,
m is an integer of 1 to 10, n is an integer of 1 to 15, and o is an integer of 1 to 10.

The method of claim 8,
Wherein the solution containing the carbodiimide compound contains 0.001 wt% or more and 0.05 wt% or less of the amine group-containing compound.

The method of claim 8,
Wherein the solution containing the carbodiimide-based compound contains the carbodiimide-based compound and the amine-containing compound at a weight ratio of 1: 2 to 1: 100.

A water treatment membrane produced by the method of manufacturing a water treatment membrane according to any one of claims 1 to 11.

A water treatment module comprising at least one water treatment separator according to claim 12.