KR101623405B1 - Method for preparing metal ion coordinated chelate adsorbents and the adsorbents - Google Patents

Abstract

A method of preparing a chelate adsorbent having a metal coordination bond according to an embodiment of the present invention includes: (1) preparing an amine compound on a polyacrylonitrile-based support to prepare a chelate support; And (2) preparing a chelate adsorbent having a metal coordination bond by bonding a metal cation to the chelate support. The adsorbent is prepared in the form of a chelate in which a porous fiber or a film-like support is used and a metal is coordinated to the surface of the adsorbent, whereby the removal efficiency of phosphorus is excellent and the adsorbent used can be easily removed.

Description

Technical Field [0001] The present invention relates to a chelate adsorbent having a metal coordination bond,

The present invention relates to a technique for removing phosphorus in an aqueous solution by introducing an amine group into a polyacrylonitrile (PAN) fiber to synthesize a chelate fiber, coordinating metal cations and then bonding phosphate ions with metal cations, .

Water pollution is becoming serious due to the increase of industrial wastewater, domestic wastewater, livestock wastewater, etc. due to population growth and industrial development. Phosphorus is the main cause of water pollution by accelerating the growth of algae by causing eutrophication. Therefore, the importance of water treatment for removing phosphorus before discharging wastewater is increasingly emphasized.

Currently, there are methods for treating such phosphorus, such as a method using a microorganism, a method using an adsorbent such as yellow loam, zeolite, silica, etc. However, it is difficult to control the driving factors of a processing step using microorganisms. There is a problem. Further, in the case of the adsorbent, there is no such problem, but it is difficult to separate and recover the adsorbent, and there is a problem of deterioration of the adsorption performance.

1. Korean Patent Laid-Open No. 10-2012-0042099, Phosphorus Removal Agent Using an Inorganic Coagulant and Manufacturing Method, May 03, 2012 2. PATENT PATENT OPEN NO. 10-1998-0008306, adsorption / decomposition type powder composition for removing organophosphorus compounds, April 30, 1998 3. U.S. Patent Publication No. 2013/0039984, Manufacture process for the preparation of an iron-containing phosphate adsorbent, Feb. 14, 2013

An object of the present invention is to provide an adsorbent in which an amine group is introduced into a polyacrylonitrile (PAN) fiber as a ligand, followed by coordination of metal cations. It is another object of the present invention to provide an adsorbent for water treatment capable of stably removing phosphate ions in various pH ranges using the adsorbent.

In order to accomplish the above object, the present invention provides a method of preparing a chelate adsorbent comprising a metal coordination bond according to an embodiment of the present invention, comprising: (1) preparing a chelate support by bonding an amine compound to a polyacrylonitrile-based support; And (2) preparing a chelate adsorbent having a metal coordination bond by bonding a metal cation to the chelate support.

The polyacrylonitrile-based support may be a polyacrylonitrile fiber, a polyacrylonitrile film, a polyacrylonitrile copolymer fiber, a polyacrylonitrile copolymer film, a polyacrylonitrile structure having a pore structure, A polyacrylonitrile copolymer structure, and a combination thereof.

The polyacrylonitrile-based support may be a polyacrylonitrile-based nanofiber obtained by electrospinning a spinning solution containing acrylonitrile.

The coupling of step (1) is carried out under a catalyst, and the catalyst may be a hydrate of a metal chloride.

The metal cation is at least one selected from the group consisting of cerium ion, iron ion, calcium ion, copper ion, cobalt ion, nickel ion, titanium ion, magnesium ion, lead ion, aluminum ion, zinc ion, chromium ion, And a potassium ion.

The metal chelate adsorbent may further comprise a first drying step of lyophilizing the chelate support between the step (1) and the step (2).

The metal chelate adsorbent may further include a second drying step of lyophilizing the metal chelate adsorbent after the step (2).

The chelate adsorbent having a metal coordination bond according to another embodiment of the present invention is a chelate adsorbent in which a metal cation coordinated to an amine compound on the surface of a polyacrylonitrile based support in the form of a sponge- .

The metal chelate adsorbent may be in the form of nanofibers, and the diameter of the nanofibers may be between 10 and 1,000 nm.

The metal chelate adsorbent may be in the form of nanofibers, and the nanofibers may have a specific surface area of 5 to 300 m ² / g.

The metal cation is at least one selected from the group consisting of cerium ion, iron ion, calcium ion, copper ion, cobalt ion, nickel ion, titanium ion, magnesium ion, lead ion, aluminum ion, zinc ion, chromium ion, And a potassium ion.

The metal cation may be bonded at 0.001 to 10 μmol per unit area (mm ² ) of the metal chelate adsorbent.

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

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies to solve the problems of the conventional methods for removing phosphorus from a water system, and have found that it is easy to separate and recover the adsorbent, The present inventors have developed an adsorbent having an excellent adsorption performance of anions such as phosphate ions by introducing an amine group as a ligand into a polymeric support such as a fibrous structure and then coordinating cationic metal ions.

A method of preparing a chelate adsorbent having a metal coordination bond according to an embodiment of the present invention comprises: (1) preparing an amine compound on a polyacrylonitrile-based support to prepare a chelate support; And (2) preparing a chelate adsorbent having a metal coordination bond by bonding a metal cation to the chelate support.

The above step (1) is a step of preparing a chelate support by bonding a compound having an amine group to a polyacrylonitrile (PAN) support.

In the present invention, the term "polyacrylonitrile-based support" means not only a support made of polyacrylonitrile but also a polymer polymerized by including acrylonitrile as a monomer, and includes a polyacrylonitrile copolymer. The polyacrylonitrile-based support may be a polyacrylonitrile fiber, a polyacrylonitrile film, a polyacrylonitrile copolymer fiber, a polyacrylonitrile copolymer film, a polyacrylonitrile structure (sponge-like structure) having a pore structure, , A polyacrylonitrile copolymer structure having a pore structure, and a combination thereof.

The polyacrylonitrile-based support serves as a support for the chelate adsorbent and may have a form such as a fibrous, film, or pore structure (sponge-like structure), and when a fibrous or film- Compared with the particle form, it has an advantage that the area contactable with water is wide and the adsorbent can be easily recovered after use.

Here, the polyacrylonitrile copolymer refers to a copolymer obtained by polymerizing vinyl monomers such as vinyl alcohol, vinyl acetate, vinyl chloride, and vinyl acetic acid together with acrylonitrile as a monomer, , And the polyacronitrile copolymer of the present invention is not limited to those exemplified above.

The polyacrylonitrile-based support may be a polyacrylonitrile-based nanofiber obtained by electrospinning a spinning solution containing acrylonitrile. When the polyacrylonitrile-based support is a polyacrylonitrile-based nanofiber produced by an electrospinning method, the polyacrylonitrile-based support may be prepared in the form of fibers in which nanofibers having a relatively uniform diameter are entangled with each other And a support having a large specific surface area can be obtained.

The amine compound acts as a ligand by bonding with the polyacrylonitrile-based support, and an organic compound containing a primary, secondary or tertiary amine group may be applied. Specifically, the amine compound means a compound in which an alkyl group, a cycloalkyl group, or an aryl group is bonded to an amine, and includes a compound having at least one primary amine group at one end of the compound. For example, one selected from the group consisting of tris (2-aminoethyl) amine, diethylenetriamine, diethylenediamine, and combinations thereof .

The bonding reaction between the polyacrylonitrile-based substrate and the amine compound in the step (1) may be conducted under a catalyst, and may be carried out at a bonding reaction temperature of 80 to 150 ° C for 10 to 36 hours. The chelating support can be efficiently prepared when the binding of the step (1) proceeds within the binding reaction temperature and the binding reaction time. When the binding reaction temperature is lower than 80 ° C, the reaction does not occur or the reaction yield is low If the coupling reaction temperature is higher than 150 ° C, the deionized water used as a solvent may evaporate and the reaction may not proceed.

The catalyst may be a hydrate of a metal chloride and specifically includes at least one selected from the group consisting of aluminum chloride hydrate, tin chloride hydrate, titanium chloride hydrate, ferric chloride hydrate, cupric chloride hydrate, cobalt chloride hydrate, nickel chloride hydrate, zinc chloride hydrate, Boron hydrate, and a combination thereof.

The bonding between the polyacrylonitrile-based support and the amine compound in the step (1) may be carried out in a solvent, and the solvent may be any solvent capable of performing the coupling reaction. For example, deionized water may be used have.

The chelate support prepared in step (1) may be further washed and dried. Since the amine groups are present on the surface of the chelate support, a hydrogen bond is formed between the chelate support and the support during the drying process, so that the support may be aggregated and hardened as a whole. Preferably, the drying may proceed by a lyophilization process. Through the filtration under reduced pressure and lyophilization, the amine group attached to the support maintains the original shape of the chelate support, so that the support does not harden or aggregate, or the chelate support can be dried at the maximum. Specifically, the freeze-drying may be performed by keeping the chelate support at a temperature of minus 40 ° C or lower and drying the chelate support.

The step (2) is a step of preparing a chelate adsorbent having a metal coordination bond by bonding a metal cation to the chelate support. Specifically, the step (2) includes the step of forming metal cations in a solution by using a metal salt such as a metal chloride, and inducing the chelate support and the metal cations to coordinate bond in solution.

The metal salt used in step (2) can be applied if it is capable of forming a metal cation under a solvent, for example, metal chloride can be used in an aqueous solution to provide a metal cation.

The metal cations cerium ion (Ce ^{3 +),} iron ions (Fe ^{2 +),} calcium ions (Ca ^{2 +),} a copper ion (Cu ^{2 +),} cobalt ion (Co ^{2 +),} nickel ion (Ni ^{2 +} ), titanium ions (Ti ^{4 +),} magnesium ions (Mg ^{2 +),} Pb (Pb ^{2 +),} aluminum ion (Al ^{3 +),} zinc ion (Zn ^{2 +),} chrome ion (Cr ^{6 +),} manganese ion may be one containing any one selected from the group consisting of (Mn ^{+ 2),} lithium ion (Li ^+), sodium ion (Na ^+), and the potassium ion (K ^+). The metal cations are preferably bound at a density of 0.001 to 10 μmol per unit area (mm ² ) of the coordinated chelate adsorbent unit.

The metal-coordinated chelate adsorbent may be further subjected to washing and drying processes to remove and dry the solvent and reaction residues. Since the chelate support having the metal coordination bond may be aggregated and hardened as a whole during drying by amine groups on the surface, care must be taken in the drying process, and it is preferable that the chelate support is dried in the lyophilization process. The details of the specific lyophilization are the same as those described above, so the description thereof will be omitted.

The chelate adsorbent having a metal coordination bond according to another embodiment of the present invention is a chelate adsorbent in which a metal cation coordinated to an amine compound on the surface of a polyacrylonitrile based support in the form of a sponge- .

The description of the polyacrylonitrile-based support, the description of the amine compound, and the description of the coordinated metal cation are the same as those described above, so that the description thereof will be omitted.

The metal chelate adsorbent may be in the form of nanofibers, nanofibers having a diameter of 10 to 1,000 nm and a specific surface area of 5 to 300 m ² / g. In the case of the range of the diameter and the specific surface area, the area which can be contacted with phosphorus in the aqueous environment is increased with a considerably wide specific surface area, and the phosphorus removal efficiency can be improved.

The metal cation may be contained in the adsorbent in an amount of 0.001 to 10 μmol per unit area (mm ² ) of the chelate adsorbent, and the removal efficiency of phosphorus may be improved.

The metal chelate adsorbent can chelate the surface of the porous fiber or the porous film and coordinate bonds of the metal cations to efficiently remove contaminants having an anion characteristic in an aqueous environment such as phosphorus.

When the metal chelate adsorbent is exposed to an aqueous system, it can efficiently remove phosphorus in an aqueous environment by adsorbing an anionic substance such as phosphorus on the surface and removing an adsorbent adsorbing phosphorus . The metal-coordinated chelate adsorbent maintains excellent adsorption performance even in a water-based system that varies within the range of acidic to neutral, and its effect is particularly excellent in an aqueous environment of pH 8 or less. This is in contrast to the characteristics of an adsorbent to which anion exchange system is applied. When the metal cation-coupled chelate fiber of the present invention is used, it is easy to adsorb and remove anions such as phosphate ions, which cause eutrophication, Good adsorption efficiency is maintained.

The method for producing a chelate adsorbent having a metal coordination bond according to the present invention and the adsorbent thereof include chelate fibers coordinated with metal cations and have excellent adsorption ability of anion or phospahte ion in an aqueous solution. Thereby providing an adsorbent which can easily collect the adsorbent. By using the water treatment method using this, eutrophication can be prevented in an aqueous solution such as a river or a river, thereby suppressing bird propagation.

FIG. 1 shows the results of FT-IR spectroscopy of nanofibers (chelate fibers) bonded to PAN nanofibers before tris (2-aminoethyl) amine (TAEA) was bonded to PAN nanofibers.
2 is an electron micrograph of the PAN nanofiber prepared by electrospinning (left) and the nanocylate fiber of Example 1. 1) (right).
3 is a graph showing the relationship between the amount of phosphorus adsorbed by fibers when the pH of the fiber of Example 1 synthesized in Production Example 1 of the present invention was adjusted to 2, 3, 4, 5, 6, 7, 8, Of the adsorbed amount.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Manufacturing example  One: Cerium ion and Tris (2-aminoethyl) Min { tris (2- aminoethyl ) amine }this Combined PAN  Manufacture of nanofibers

1) an amine compound and Combined  Nano Chelate  Manufacture of fibers

0.5 g of PAN nanofibers prepared by electrospinning was placed in a 300 ml volumetric round bottom flask with 15 ml of tris (2-aminoethyl) amine (TAEA), and deionized water) as a solvent and dispersed evenly at room temperature for 30 minutes. After 5 g of AlCl ₃ .6H ₂ O used as a catalyst was added, the mixture was further stirred at room temperature for about 1 hour.

After the catalysts were all melted, a reflux condenser was installed and the reaction was carried out at a reaction temperature of 80 to 150 ° C for 10 to 36 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and washed several times with secondary distilled water.

In order to remove the aluminum hydroxide due to the catalyst, it was washed with 0.1 N hydrochloric acid aqueous solution and then repeatedly washed with 0.1 N aqueous sodium hydroxide solution and deionized water. The modified PAN nanofibers were separated by vacuum filtration, and finally, the chelate fibers were prepared through lyophilization.

FIG. 1 shows the results of FT-IR spectroscopy of nanofibers (chelate fibers) bonded to PAN nanofibers before tris (2-aminoethyl) amine (TAEA) was bonded to PAN nanofibers. Referring to FIG. 1, it can be seen that the nitrile group is disappeared and the amine group is increased in the FT-IR spectrum of the chelate fiber after bonding as compared with the FT-IR spectrum before binding. From this, it is confirmed that the nanocylate fiber is well synthesized Could.

2 is an electron micrograph of the PAN nanofiber prepared by electrospinning (left) and the nanocilaate fiber prepared in 1) of Example 1 (right). Referring to FIG. 2, it was confirmed that the nanoclase fibers of Example 1. 1) prepared through chelation using an amine compound also maintained nanofiber morphology.

2) Preparation of chelate fibers coordinated with metal cations

0.1 g of the fiber was immersed in 1 L of a 0.1 M aqueous solution of cerium chloride for 30 minutes, followed by washing with deionized water and lyophilization to cerium ions and tris (2-aminoethyl) The fibers of Example 1, which is a PAN nanofiber bonded with an amine {tris (2-aminoethyl) amine}, were synthesized.

Manufacturing example  2: Cerium ion and Diethylenetriamine is a Combined PAN  Manufacture of nanofibers

The procedure of Example 1 was repeated except that 15 ml of diethylenetriamine was used instead of 15 ml of tris (2-aminoethyl) amine in 1) to prepare a mixture of cerium ion and diethylene triamine-conjugated PAN The fibers of Example 2, a nanofiber, were synthesized.

Manufacturing example  3: Cerium ion and Ethylenediamine (diethylenediamine) Combined PAN  Manufacture of nanofibers

The procedure of Example 1 was repeated except that 15 ml of diethylenediamine was used instead of 15 ml of tris (2-aminoethyl) amine in 1) to prepare PAN nanofibers having cerium ion and ethylenediamine bonded thereto The fibers of Example 3 were synthesized.

Manufacturing example  4: Iron ion and Tris (2-aminoethyl) Min { tris (2- aminoethyl ) amine } Combined PAN  Manufacture of nanofibers

In the same manner as in Example 1, except that 1 L of 0.1 M aqueous solution of cerium chloride was used instead of 0.1 M of iron chloride in 0.1 M of iron chloride, the iron ion and tris (2-aminoethyl) amine were bonded The PAN nanofibers of Example 4 were synthesized.

Manufacturing example  5: Copper ion and Tris (2-aminoethyl) Min { tris (2- aminoethyl ) amine }this Combined PAN  Manufacture of nanofibers

The procedure of Example 1 was repeated except that 1 L of 0.1 M cerium chloride aqueous solution was used instead of 0.1 M copper chloride in Example 2, and copper ion and tris (2-aminoethyl) amine The fibers of Example 5, the bonded PAN nanofibers, were synthesized.

Experimental Example : pH  Evaluation of phosphorus adsorption according to change

Evaluation of adsorption amount according to pH was carried out using the fiber of Example 1 synthesized in Production Example 1 above. Several pH aqueous solutions containing 10 mmol of phosphorus were prepared and the pH of the aqueous phosphorus solution was adjusted to 2, 3, 4, 5, 6, 7, 8, 9 and 10, 0.1 g of each of the prepared fibers was placed in 100 mL of a pH-adjusted phosphorus aqueous solution sample, and allowed to stand for 24 hours to adsorb phosphorus in the aqueous solution to the fibers.

The adsorbed phosphorus was recovered and the adsorbed amount of phosphorus adsorbed in each pH environment was determined by reversing the solution in which the fibers were removed. The results are shown in FIG.

Referring to the results of FIG. 3, it can be seen that the fiber of Example 1 exhibits excellent adsorption efficiency even at a pH of 2, which is a strong acidic environment, and has a very excellent adsorption performance even at pH 7, which is a neutral environment. In addition, it was confirmed that the adsorption of phosphorus is possible even though the pH is lower than the acidic or neutral environment at pH 8 to 10, which is a weak basic environment.

From the above results, it was confirmed that the use of the adsorbent of the present invention can stably remove phosphorus and the like in a general aqueous system, and it is easy to recover the adsorbed phosphorus I can confirm that I have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (10)

A chelate support in which an amine compound is bonded to a polyacrylonitrile-based support,
Wherein the chelate adsorbent is in the form of a nanofiber, wherein the nanofiber has a diameter of 10 to 1,000 nm and a specific surface area of 5 to 300 m ² / gt; adsorbent. < / RTI > delete The method according to claim 1,
Wherein the nanofiber is a polyacrylonitrile nanofiber obtained by electrospinning a spinning solution containing acrylonitrile. delete The method according to claim 1,
Wherein the metal cation comprises any one selected from the group consisting of iron ion, copper ion, cobalt ion, nickel ion, titanium ion, aluminum ion and zinc ion. delete 6. The method of claim 5,
Wherein the metal cation is bound in an amount of 0.001 to 10 μmol per unit area (mm ² ) of the metal chelate adsorbent. delete delete delete

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