KR102104719B1 - Cesium ion exchange resin and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a cesium ion exchange resin containing a prussian blue that can be used as an adsorbent and removal agent for cesium ions by forming a prussian blue layer on the surface of the cation exchange resin and a method for manufacturing the same. More specifically, a cation exchange resin formed by forming a prussian blue layer on the surface of a cation exchange resin coated with polydopamine, or a cation exchange resin formed by forming a prussian blue layer on the surface, and cesium ion exchange resin performing polydopamine coating, and It relates to a manufacturing method.

Description

Cesium ion exchange resin and manufacturing method thereof

The present invention, after synthesizing prussian blue on the surface of the cation exchange resin, the surface of the cation exchange resin synthesized with the prussian blue is coated with polydopamine, or the surface of the cation exchange resin coated with polydopamine is coated with prussian blue. A cesium ion exchange resin for adsorption and removal of cesium prepared by synthesis, and a method for manufacturing the same.

In 2011, as the first nuclear power plant accident in Fukushima, Japan, a large amount of radioactive substances, such as iodine, strontium, and cesium, were released through the atmosphere and water, greatly affecting the natural world. Is going crazy. Among them, cesium-137 is a major fission product, and has a long half-life of 30 years, and has a characteristic of emitting strong gamma rays as the cesium-137 collapses. The cesium-137 is a water-soluble substance that dissolves in water and enters the human body through various routes, and the cesium that has entered the human body gathers in tissues such as muscles and releases harmful gamma rays, thereby harming the human body. Therefore, many studies have been conducted to remove cesium.

Adsorption is widely used as a method for removing radioactive substances such as cesium ions (Cs ⁺ ) present in water. Prussian Blue (hereinafter referred to as PB) is widely known as a substance capable of removing cesium ions through adsorption. The PB is a material having a face-centered cubic structure formed through a combination of a metal and an organic material, as shown in FIG. That is, as illustrated in FIG. 1, adsorption proceeds as the cesium ions enter the PB lattice through ion exchange between potassium ions and potassium ions present in the lattice of the PB. That is, it is known that the lattice size of the PB is suitable for adsorption of cesium ions, and thus has selectivity for cesium. However, since the PB has a small nano-sized size, it has difficulties in treatment and recovery after use in the field.

As a related art related to the present invention, Korean Patent Application Publication No. 10-2015-0105392 (2015. 09. 16.) includes amorphous and crystalline materials having selective adsorption properties to radionuclides such as cesium and strontium from water including seawater. Titanosilicate has been disclosed.

In addition, Korean Patent Application Publication No. 10-2005-0120312 (December 22, 2005) relates to a method for regenerating an ion exchanger selectively acting on cesium and strontium ions, specifically, selectively adsorbed and saturated ions It relates to a method of dramatically reducing the amount of secondary waste generated by decontaminating contaminated soil with a chemical solution by regenerating the exchange resin by oxidation and reduction.

However, the prior art still elutes upon adsorption of cesium ions in the form of particulates, or there is a difficulty in treatment and recovery after use, and there is a secondary environmental pollution problem due to diffusion and accumulation of adsorbents. In addition, excessive treatment cost is required when regenerating an ion exchanger adsorbing cesium and strontium ions, and there is a limit in adsorbing cesium distributed in a low concentration in radioactive waste liquid or water with high efficiency.

Therefore, there is no problem that PB is eluted into water upon adsorption of cesium ions, and ion exchange resins that are easy to treat and recover after use and can adsorb cesium ions distributed at low concentrations in water with high efficiency are required.

An object of the present invention is a cation exchange resin capable of selective ion exchange for cesium ions, and prevents a phenomenon in which PB particles are eluted and aggregated in water when adsorbing cesium ions through a polymer coating on the surface of the cation exchange resin, , To provide a cesium ion exchange resin that can be used in various aquatic environments with high structural stability and a method for manufacturing the same.

The cesium ion exchange resin of the present invention for achieving the above object is a cation exchange resin; Polydopamine layer; And a Prussian blue layer. In particular, the Prussian blue layer is located on the cation exchange resin, and the polydopamine layer may be provided on the Prussian blue layer. In addition, in the cesium ion exchange resin of the present invention, the polydopamine layer is located on the cation exchange resin, and the prussian blue layer may be provided on the polydopamine layer.

And the method of manufacturing a cesium ion exchange resin of the present invention comprises the steps of preparing a cation exchange resin; Introducing iron (III) ions into the surface of the cation exchange resin by immersing the cation exchange resin in an aqueous solution of iron (III) ions; Forming a prussian blue layer on the surface of the cation exchange resin by immersing the cation exchange resin into which iron (III) ions are introduced in an aqueous ferrocyanic acid solution; It is preferable to include; coating the surface of the cation exchange resin having the Prussian blue layer on the surface with polydopamine. In addition, the method for producing a cesium ion exchange resin of the present invention comprises the steps of preparing a cation exchange resin; Coating the cation exchange resin with polydopamine; Introducing iron (III) ions into the surface of the cation exchange resin by immersing the cation exchange resin coated with the polydopamine in an aqueous solution of iron (III) ions; It is preferable to include; immersing a cation exchange resin in which iron (III) ions are introduced on the surface in an aqueous ferrocyanic acid solution to form a prussian blue layer on the surface of the cation exchange resin.

The cesium ion exchange resin according to the present invention has an advantage of maximizing the adsorption amount of cesium ions per unit weight of the cation exchange resin by increasing ion exchange with cesium ions by introducing PB on its surface. In addition, by coating the surface of the cation exchange resin with polydopamine, PB desorption and elution from the cation exchange resin can be prevented to prevent recontamination in water. In addition, it is possible to increase the adsorption efficiency of cesium ions in the cation exchange resin and impart stability to the pH.

1 is a schematic diagram showing the adsorption process (b) of Prussian blue crystal particles (a) and cesium ions,
2 and 3 is a schematic diagram for a method of manufacturing a cesium ion exchange resin according to an embodiment of the present invention.

In describing the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's intention or precedent. Therefore, the definition should be made based on the contents throughout this specification.

As previously described, when PB introduced to the surface of a cation exchange resin is used for adsorption of cesium ions in an aqueous solution, there may be a problem that PB is eluted from the surface of the ion exchange resin. Therefore, the present invention solves the above problem by consolidating the binding of PB to the cation exchange resin by using polydopamine as a binder material to solve the above problems.

Polydopamine (polydopamine) is a material having a molecular structure similar to that of an adhesive protein, and it is possible to coat all materials and has biocompatibility. In addition, there is a group called catechol, which is capable of binding with metal ions, and has the advantage of easily performing the surface modification of the material by using this.

The present invention relates to a cesium ion exchange resin capable of efficient cesium adsorption and removal provided with stability to the surrounding environment by solving the elution problem of PB by coating on a cation exchange resin using the excellent adhesive properties of polydopamine.

That is, the present invention prevents re-contamination in water by preventing PB desorption and elution from the cation exchange resin by introducing PB adsorbing cesium ions onto the surface of the cation exchange resin, thereby increasing the adsorption efficiency of cesium ions. A cesium ion exchange resin is provided.

Hereinafter, the cesium ion exchange resin according to the present invention and its manufacturing method will be described in detail based on the accompanying drawings. Figure 1 attached to the present invention is a schematic diagram showing the adsorption process (b) of Prussian blue crystal particles (a) and cesium ions, and FIGS. 2 and 3 are views of a cesium ion exchange resin according to an embodiment of the present invention. It is a schematic diagram of the manufacturing method.

The cesium ion exchange resin according to an embodiment of the present invention synthesizes PB in sulfonic acid (-SO ₃ H) present in the cation exchange resin, or irons in the catechol portion of polydopamine coated on the surface of the cation exchange resin. It can be prepared by introducing (III) ions and synthesizing PB at the portion where the iron (III) ions are introduced.

At this time, the PB synthesized in the cesium ion exchange resin is iron (III) ions and iron (II) ions as iron (III) ions (Fe ^{3 +} ) come into contact with the cyano group (-CN) provided from ferrocyanic acid. (Fe ²⁺ ) is bonded to nitrogen (N) and carbon (C) of the cyano group, respectively, as shown in FIG. 1, and the structural formula KFe ₄ [Fe ²⁺ (CN) ₆ ] ₃ ㆍ xH ₂ O-based face-centered cubic structure It is characterized by having.

The PB introduced into the cesium ion exchange resin is characterized in that selective adsorption of the cesium ions is possible as the potassium ions (K ⁺ ) present in the lattice and the cesium ions (Cs ⁺ ) to be removed are ion-exchanged with each other.

Therefore, by applying these properties to a cation exchange resin, a cesium ion exchange resin that can easily adsorb and remove cesium ions can be produced.

In addition, the cesium ion exchange resin prepared in this way is coated with polydopamine on the surface to suppress the elution of PB during field use, thereby preventing colloid formation due to the elution of the PB, thereby improving the stability to the environment. Have

The method of manufacturing the cesium ion exchange resin of the present invention proposes two manufacturing methods by varying the order of PB synthesis and polydopamine coating on the surface of the cation exchange resin.

That is, in the method (I) of preparing a cesium ion exchange resin according to an embodiment of the present invention, iron (III) is deposited on the surface of the cation exchange resin by immersing the cation exchange resin in an aqueous solution of iron (III) ions as shown in FIG. Step of introducing ions (step I-1); and, by immersing the cation exchange resin with iron (III) ions prepared in step I-1 in a solution of ferrocyanic acid, PB is deposited on the surface of the cation exchange resin. Synthesizing (Step I-2); And coating the surface of the cation exchange resin synthesized with the PB on the surface prepared in step I-2 with polydopamine (step I-3).

The step I-1 is a step of introducing iron (III) ions to the surface of the cation exchange resin, and is a step of preparing PB to be combined with the surface of the cation exchange resin. That is, in step I-1, iron (III) is added to sulfonic acid (-SO ₃ H) present in the cation exchange resin by immersion in an aqueous solution of iron (III) ions. This is the step of introducing ions.

In addition, step I-2 is a step of synthesizing PB on the surface of the cation exchange resin by immersing the cation exchange resin in which iron (III) ions are attached in step I-1 in an aqueous ferrocyanic acid solution. The PB is spontaneously synthesized at room temperature on the surface of the cation exchange resin to which iron (III) ions are attached.

And step I-3 is a step of imparting the durability of the PB to the cesium ion exchange resin of the present invention prepared by coating the surface prepared in step I-2 with cation exchange resin synthesized with PB with polydopamine. The polydopamine is self-polymerized by immersing the cation exchange resin in which PB is synthesized on the surface in an aqueous dopamine solution to coat the polydopamine. The coating step of the polydopamine proceeds by immersing the cation exchange resin in which PB is synthesized on the surface of the dopamine aqueous solution, and the pH of the dopamine aqueous solution is preferably 8-10. Since the coating speed of polydopamine is the fastest in the aqueous solution of dopamine of pH 8 to 10, the coating time can be shortened.

The polydopamine (polydopamine) is a polymer having a molecular structure similar to the mussel family protein, and the polydopamine is a catechol amine-based organic compound, a neurotransmitter found in the central nervous system of various animals. In particular, it is known that the polydopamine has properties similar to a family protein that attaches mussels to rocks and the like in water.

The polymerized polydopamine has a catechol group that acts as a chelating agent. By forming the Fe ³⁺ or Fe ^{2 +} coordinate bonds with the catechol groups present in the poly dopamine coated on the cation-exchange resin is PB, is firmly fixed to the PB.

By coating the cation exchange resin synthesized with PB on the surface with polydopamine as described above, the durability of the PB can be imparted by solving the problem of dissolution of PB synthesized on the surface of the cation exchange resin during use.

In addition, the method (II) of preparing a cesium ion exchange resin according to another embodiment of the present invention comprises the steps of coating a cation exchange resin with polydopamine as shown in FIG. 3 (step II-1); Introducing iron (III) ions to the surface of the cation exchange resin by immersing the cation exchange resin coated with the polydopamine prepared in step II-1 in an iron (III) ion aqueous solution (step II-2); And synthesizing PB on the surface of the cation exchange resin by immersing the cation exchange resin coated with polydopamine with iron (III) ions attached to the surface prepared in step II-2 in a solution of ferrocyanic acid (step II- 3); is characterized by including.

Step II-1 is a step of coating polydopamine on a cation exchange resin. In step II-1, a polydopamine may be coated on the surface of the cation exchange resin by immersing the cation exchange resin in an aqueous dopamine solution. Through this, durability to the cation exchange resin can be imparted, and PB can be synthesized by catechol present in polydopamine in a subsequent process. As described above, in step II-1, the pH of the dopamine aqueous solution is preferably 8 to 10.

In addition, step II-2 is a step of introducing iron (III) ions to the surface of the cation exchange resin coated with the polydopamine prepared in step II-1. That is, iron (III) on the surface of the cation exchange resin by immersing the cation exchange resin coated with the polydopamine prepared in step II-1 in an iron (III) ionic aqueous solution. This is the step of introducing ions. Step Ⅱ-2 is iron (III) on the surface of the cation exchange resin as described above. This is a step to prepare PB to be synthesized in a subsequent process by introducing ions. And step Ⅱ-3 is iron (III) on the surface prepared in step 2-2. PB is synthesized in the cation exchange resin into which ions are introduced. The step II-3 is iron (III) on the surface prepared in the step II-2. It is a step of synthesizing PB on the surface of the cation exchange resin by immersing the cation exchange resin into which the ions have been introduced in an aqueous ferrocyanic acid solution.

It is possible to adsorb and remove cesium ions of the present invention through two methods of manufacturing the cesium ion exchange resin. It provides a method for manufacturing a cesium ion exchange resin coated with polydopamine.

The cesium ion exchange resin of the present invention prepared by the above method can maximize the adsorption amount of cesium ions per unit weight of the cation exchange resin by increasing ion exchange with cesium ions, and PB desorption from the cation exchange resin And preventing elution to prevent recontamination in water. In addition, by coating the surface of the cation exchange resin with polydopamine, it is also possible to increase the adsorption efficiency of cesium ions of the cation exchange resin and provide stability to pH.

Hereinafter, the present invention will be described in more detail with reference to Examples. The following examples are for illustrative purposes only, and it is apparent to those skilled in the art that various changes and modifications can be made within the scope and scope of the present invention, and it is obvious that such modifications or modifications fall within the scope of the appended claims. .

( Manufacturing example  1) Preparation of cesium ion exchange resin by the method (I) of the production of cesium ion exchange resin

(Step Ⅰ-1)

1 g of cation exchange resin was immersed in 1 wt% aqueous solution of iron chloride (FeCl ₃ ) to introduce iron ions into the sulfonic acid group (-SO ₃ H) of the cation exchange resin. As described above, the cation exchange resin into which iron ions were introduced was washed 2-3 times with distilled water.

(Step I - 2)

The cation exchange resin introduced with the iron ions prepared in step I-1 was immersed in an aqueous solution of 1% by weight of potassium hexacyanoferrate (II) trihydrate to make PB on the surface of the cation exchange resin. Was synthesized.

(Step Ⅰ-3)

To the surface prepared in step I-2, a cation exchange resin synthesized with PB was added to 20 mL of 10 mM Tris-HCl buffer in which 0.04 g of dopamine hydrochloride was dissolved, and vigorous stirring was performed. The pH of the aqueous dopamine solution is 8.5, and at this time, the polydopamine spontaneously polymerizes on the surface of the cation exchange resin to be coated. The cesium ion exchange resin prepared as above was washed 2-3 times with distilled water.

( Manufacturing example  2) Preparation of cesium ion exchange resin by the method of manufacturing cesium ion exchange resin (II)

(Step II - 1)

1 g of cation exchange resin was added to 20 mL of 10 mM Tris-HCl buffer in which 0.04 g of dopamine hydrochloride was dissolved, and vigorous stirring was performed. At this time, the pH of the aqueous solution of dopamine was 8.5, and the surface of the cation exchange resin was coated with polydopamine as described above. Thereafter, the cation exchange resin was washed 2-3 times with distilled water.

(Step II - 2)

The cation exchange resin coated with polydopamine on the surface prepared in step Ⅱ-1 was immersed in a 1% by weight aqueous solution of iron chloride (FeCl ₃ ) and iron was added to the catechol group of the polydopamine layer present in the upper layer of the cation exchange resin ( Ⅲ) Introduce ions. As described above, the cation exchange resin into which iron (III) ions were introduced was washed 2-3 times with distilled water.

(Step Ⅱ-3)

The cation exchange resin was immersed in an aqueous solution of 1% by weight of potassium hexacyanoferrate (II) trihydrate in which the iron (III) ion prepared in step II-2 was introduced. PB was synthesized on the surface.

( Example  1) of aqueous solution Cesium ion concentration  Cesium ion removal evaluation of cesium ion exchange resin

For the evaluation of cesium ion removal performance according to the cesium ion concentration of the cesium ion exchange resin of the present invention, each of the 40 mg of cesium ion exchange resins of the present invention prepared in Preparation Example 1 and Preparation Example 2 was 1, 10, 50 and 100 ppm. Each was dispersed in 20 mL of a cesium ion aqueous solution having a concentration and immersed for 24 hours. Thereafter, the content of the remaining cesium ion was measured from the filtrate of the cesium ion aqueous solution from which each cesium ion exchange resin was removed using an inductively coupled plasma mass spectrometer (ICP-MS), and the cesium ion removal rate was calculated according to the following equation (1). Was calculated. The results are shown in Table 1 below.

In the above (Formula 1), C ₀ is the content of the initial cesium ion in the aqueous cesium ion solution, and C _t indicates the content of the cesium ion in the filtrate after 24 hours.

Cesium ion removal rate Cesium ion initial concentration 1 ppm 10 ppm 50 ppm 100 ppm Preparation Example 1 98% 90% 68% 50% Preparation Example 2 99% 96% 75% 58%

As shown in Table 1, both Preparation Example 1 and Preparation Example 2 show high cesium ion removal rates. Particularly, when the initial concentration of cesium ions is 10 ppm or less, the removal rate is 90% or more. In addition, even when the initial concentration of cesium ions is 100 ppm or less, it shows a high removal rate of cesium ions of 50% or more.

( Example  2) Evaluation of cesium ion removal of cesium ion exchange resin according to the pH of aqueous solution

In order to evaluate the cesium ion removal performance according to the pH change of the cesium ion aqueous solution for the cesium ion exchange resin of the present invention, 40 mg of the cesium ion exchange resins prepared in Preparation Examples 1 and 2, respectively, of 10 ppm of cesium ions The contents were immersed in 20 mL of cesium ion aqueous solutions (10 ppm) at pH 2, 4, 7, 10 for 24 hours. Subsequently, the content of cesium ions remaining from the filtrate of the cesium ion aqueous solution from which each cesium ion exchange resin was removed was measured using an inductively coupled plasma mass spectrometer (ICP-MS), and the cesium ion removal rate was calculated based on the above (Formula 1). It was calculated. The results are shown in Table 2 below.

( Comparative example  1) Evaluation of cesium ion removal of cation exchange resin according to pH of aqueous solution

In order to evaluate the removal performance of cesium ions according to the change of the pH of the aqueous solution of cesium ions with respect to the cation exchange resin, cesium ions of pH 2, 4, 7, and 10 having a content of cesium ions of 10 ppm for each 40 mg of general cation exchange resin Each of 20 mL of aqueous solution was immersed for 24 hours. Thereafter, the content of cesium ions remaining in the filtrate of the cesium ion aqueous solution from which the cation exchange resin was separated was measured using an inductively coupled plasma mass spectrometer, and the cesium ion removal rate was calculated based on the above (Formula 1).

Cesium ion removal rate PH of cesium ion aqueous solution 2 4 7 10 Preparation Example 1 68% 80% 91% 81% Preparation Example 2 72% 85% 95% 88% Comparative Example 1 10% 15% 23% 12%

As shown in Table 1, it can be seen that both Preparation Example 1 and Preparation Example 2 show a higher removal rate of cesium ions than Comparative Example 1. In addition, it can be seen that in the case of Production Example 1 and Production Example 2 according to an embodiment of the present invention, the removal rate of cesium ions is higher than 80% in a pH range of 4 to 10.

Although one embodiment of the present invention has been described above, it will be understood that the present invention is not limited to the forms mentioned in the above detailed description. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims. It is also to be understood that the present invention includes all modifications, equivalents, and substitutes within the spirit of the invention as defined by the appended claims.

Claims (5)

delete Cation exchange resin;
A prussian blue layer located on the cation exchange resin; And
A cesium ion exchange resin comprising a; polydopamine layer located on top of the prussian blue layer.
Cation exchange resin;
A polydopamine layer located on the cation exchange resin; And
Cesium ion exchange resin comprising a; prussian blue layer located on top of the polydopamine layer.
Preparing a cation exchange resin;
Introducing iron (III) ions into the surface of the cation exchange resin by immersing the cation exchange resin in an aqueous solution of iron (III) ions;
Forming a prussian blue layer on the surface of the cation exchange resin by immersing the cation exchange resin into which iron (III) ions are introduced in an aqueous ferrocyanic acid solution;
Coating the surface of the cation exchange resin having the prussian blue layer on the surface with polydopamine;
Method for producing a cesium ion exchange resin comprising a.
Preparing a cation exchange resin;
Coating the cation exchange resin with polydopamine;
Introducing iron (III) ions into the surface of the cation exchange resin by immersing the cation exchange resin coated with the polydopamine in an aqueous solution of iron (III) ions;
Forming a Prussian blue layer on the surface of the cation exchange resin by immersing the cation exchange resin in which iron (III) ions are introduced on the surface in an aqueous ferrocyanic acid solution;
Method for producing a cesium ion exchange resin comprising a.

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