KR102498178B1 - Sponge type sorbent media coated with reduced graphene oxide for removal of organic compound and oil contaminants and the manufacturing method thereof - Google Patents

Abstract

The sponge-type sorbent medium according to the present invention can effectively sorb and remove organic and oil contaminants in water and in the ground, for example, non-polar organic compounds such as phenol compounds, and can be reused several times due to its excellent physical and chemical stability. Therefore, it is easy to use and excellent in terms of economic feasibility, and aggregation or restacking of graphene oxide or reduced graphene oxide is effectively prevented, and a three-dimensional network structure between graphene oxide and reduced graphene oxide is formed. , the sorption performance can be optimized. Accordingly, the sponge-type sorbent medium according to the present invention is easy to apply to the water treatment process, easy to recover, and has the advantage of not generating secondary pollutants such as sludge. It can be used as a substitute for the absorbent cloth or as a supplementary material that supplements it.

Description

Sponge type sorbent media coated with reduced graphene oxide for removal of organic compound and oil contaminants and the manufacturing method thereof

The present invention relates to a sponge-type sorbent medium coated with reduced graphene oxide for sorption and removal of organic and oil contaminants and a manufacturing method thereof.

Among soil contamination, the problem of contamination of underground soil layer and groundwater due to oil leaking from gas stations, factories, or oil storage facilities of military bases has recently emerged. Most of the contaminants caused by oil exist in the form of non-aqueous phase liquids, and can be divided into light non-aqueous phase liquids (LNAPLs) and dense non-aqueous phase liquids (DNAPLs), which are lighter than water. In particular, LNAPLs exist in the upper layer of soil and groundwater and contaminate soil and groundwater simultaneously. Oil contaminants act as a continuous pollutant due to their relatively low solubility, delayed migration characteristics, and residual saturation in the soil. When volatilized into the air, they cause toxicity, carcinogenicity, growth disorder, and deformity to receptors, so they cannot be effectively removed. There is a need.

Graphene is a carbon allotrope with a honeycomb-shaped two-dimensional planar structure in which carbon atoms are sp ² bonded. Graphene has an atomic unit thickness (0.2 nm) and a very large specific surface area of about 2,630 m ² /g, and a very high instinsic electron mobility of 200,000 cm ² /V s, ~5000 W/m It has excellent physical properties such as high thermal conductivity of K.

Meanwhile, the graphene manufacturing process largely includes chemical exfoliation and chemical vapor deposition. Among them, the chemical exfoliation method known as Hummer's method is advantageous for mass production and is widely used. The form of graphene oxide (GO) may be further reduced to produce reduced graphene oxide (rGO).

The graphene oxide, particularly the reduced graphene oxide, forms a π-π interaction with organic pollutants in water by electrostatic attraction due to its large specific surface area and high electrical conductivity, so it can be used to effectively remove organic pollutants in water. Pollutant adsorption studies using GO or rGO conducted so far have been mainly conducted with powder-type materials, and these powder-type materials are used as a reaction material in a continuous treatment process or a permeable reactive barrier (PRB). Due to the difficulty of separation/recovery in the aqueous phase, its practical use is limited.

In addition, in the process of drying graphene oxide or reduced graphene oxide, restacking between layers of graphene oxide occurs and the inherent properties of the material are lost, preventing restacking and having a three-dimensional network structure effective for sorption. This is a situation in which an appropriate carrier is required for this.

In the present invention, when graphene oxide (GO) or reduced graphene oxide (rGO) is coated on a porous sponge-type carrier according to a self-assembly method as a prior art, the manufacturing process is complicated, and mass production is difficult. In order to overcome problems such as difficulty and difficulty in reuse due to poor physical strength, a sponge-type sorbent medium coated with graphene oxide particles or reduced graphene oxide particles is prepared by a simpler dip-coating method, Method for manufacturing a sponge-type sorption medium capable of exhibiting optimum sorption performance by establishing optimal process conditions for the case of coating pin oxide particles and the case of coating reduced graphene oxide particles, respectively, and the sponge-type sorption prepared thereby to provide a medium.

In addition, the technical problem to be solved by the present invention is not limited to the above-mentioned technical problem, and other technical problems not mentioned above will become clear to those skilled in the art from the description below. You will be able to understand.

In the present specification, a) ultrasonic cleaning and drying the sponge; b) immersing the sponge in a graphene solution containing at least one selected from graphene oxide and reduced graphene oxide, and physically squeezing the sponge; c) primary heat treatment of the sponge obtained in step b for 3 to 5 hours; d) ultrasonically cleaning the sponge obtained in step c to remove overcoated particles on the surface of the sponge; and e) subjecting the sponge to a secondary heat treatment for 3 to 5 hours; It provides a method for producing a sponge-type sorbent medium comprising a.

In addition, the present specification provides a sponge-type sorption medium manufacturing method in which the graphene solution in step b is titrated to a pH in the range of 9 to 10 with an ammonia solution.

In addition, in the present specification, the graphene solution in step b is a graphene oxide solution, and the heat treatment in steps c and e is performed within a temperature range of 50 to 70 ° C. to provide.

In addition, in the present specification, the graphene solution of step b is a reduced graphene oxide solution, and the reduced graphene oxide solution is obtained by heat-treating a graphene oxide solution within a temperature range of 90 to 110 ° C. , It provides a method for producing a sponge-type sorbent medium.

In addition, in the present specification, the graphene solution of step b is a reduced graphene oxide solution, and the heat treatment of steps c and e is performed within a temperature range of 90 to 110 ° C., preparing a sponge-type sorbent medium provides a way

In the present specification, a sponge-type sorbent medium prepared according to the above method, wherein the sponge-type sorbent medium is coated with at least one type of particles selected from graphene oxide particles and reduced graphene oxide particles on the surface of the sponge. provides

In addition, in the present specification, the sponge provides a sponge-type sorbent medium that is a polyurethane-based, melamine-based, or polyvinyl alcohol-based sponge.

In addition, the present specification provides a sponge-type sorption medium in which the surface of the sponge-type sorption medium has a contact angle with respect to water of 110° or more.

In addition, the present specification provides a sponge-type sorption medium in which the graphene oxide particles coated on the surface of the sponge and the reduced graphene oxide particles are included in 1 to 10% by weight based on the total weight of the sponge-type sorption medium.

In addition, in the present specification, the sponge-type sorbent medium removes organic and oil contaminants in water and underground through at least one mechanism selected from surface adsorption, capillary force, and suction on the pore surface and inside of the sponge. To provide a sponge-type sorbent medium that is sorbed to.

In addition, in the present specification, the sponge-type sorbent medium has an adsorption amount (q _e ) of 18 mg/g or more for 24 hours under a pH of 4 condition in the water phenol adsorption removal test.

In addition, in the present specification, the sponge-type sorbent medium has an adsorption amount (q _e ) of 17 mg/g or more for 24 hours under a pH of 7 condition in the water phenol adsorption removal test.

In addition, the sponge-type sorption medium in the present specification provides a sponge-type sorption medium having an adsorption amount (q _e ) of 14 mg/g or more for 24 hours under a pH 10 condition in the water phenol adsorption removal test.

In the present specification, as a method for treating organic and oil pollutants in water and underground, the sponge-type sorbent medium is put into contaminated water to absorb and remove organic compounds or oil pollutants in water or underground, organic and A method for removing oil contaminants by sorption is provided.

In addition, in the present specification, the organic compound is a phenol-based compound, and a method for sorbing and removing organic and oil contaminants is provided.

The sponge-type sorbent medium according to the present invention can effectively sorb and remove organic and oil contaminants in water or underground, for example, non-polar organic compounds such as phenol compounds, and can be reused several times due to its excellent physical and chemical stability. Therefore, it is easy to use and excellent in terms of economy.

In addition, according to the sponge-type sorbent medium manufacturing method according to the present invention, agglomeration or restacking of graphene oxide or reduced graphene oxide is effectively prevented, and a three-dimensional network structure between graphene oxide and reduced graphene oxide is formed. By doing so, the sorption performance can be optimized.

In addition, the sponge-type sorbent medium according to the present invention is easy to apply to the water treatment process, easy to recover, and has the advantage of not generating secondary pollutants such as sludge, which is currently used as a follow-up measure in case of underwater and underground oil contamination. It can be used as a substitute for the absorbent cloth or as a supplementary material that supplements it.

1 schematically illustrates a process of preparing graphene oxide and reduced graphene oxide through a chemical exfoliation method, Hummer's method.
2 shows an adsorption mechanism between graphene oxide and reduced graphene oxide and organic/inorganic ions.
3 schematically illustrates a mechanism in which graphene oxide and a sponge are bonded according to an embodiment of the present invention.
Figure 4 schematically shows a process of coating graphene oxide or reduced graphene oxide particles on the surface of a sponge in a dip-coating method according to an embodiment of the present invention.
Figure 5 shows the observation of the surface of the sponge prepared for each heat treatment temperature according to an embodiment of the present invention using an optical microscope.
6 shows a sponge and a sponge surface before and after coating reduced graphene oxide according to an embodiment of the present invention.
7 shows the result of confirming the hydrophobicity of the sponge-type sorption medium (rGO-PU) prepared according to an embodiment of the present invention.
8 shows the result of analyzing the coating amount according to the number of times of coating reduced graphene oxide on a polyurethane material (PU) sponge according to an embodiment of the present invention.
9 shows the result of a phenol adsorption/removal test in water of a sponge-type sorbent medium (rGO-PU) prepared according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present description, descriptions of already known functions or configurations will be omitted to clarify the gist of the present description.

On the other hand, the term "sorbent" used throughout the specification and claims of the present invention is a concept that includes both absorption and adsorption, and in the present invention, an organic compound is applied to the surface of a porous sponge-type medium. and adsorbing oil contaminants or absorbing organic compounds and oil contaminants into macropores.

As described above, when the underground soil layer and groundwater are contaminated due to oil leaking from gas stations, factories, or oil storage facilities of military units, GO or rGO in powder form has been used. When using a permeable reactive barrier (PRB) as a reactive material, its practical use is limited due to difficulties in separation/recovery in an aqueous solution, and in the process of drying graphene oxide or reduced graphene oxide, restacking between layers of graphene oxide ) occurs and the inherent properties of the material are lost, so an appropriate carrier for preventing re-stacking and having a three-dimensional network structure effective for adsorption and absorption is required. In this regard, when graphene oxide (GO) or reduced graphene oxide (rGO) is coated on a porous sponge-type carrier according to the prior art self-assembly method, the manufacturing process is complicated, and mass production is difficult, Problems such as poor physical strength and difficulty in reuse occurred.

The present inventors coated graphene oxide particles or reduced graphene oxide particles on a sponge made of a porous material by a dip-coating method, which is simpler than the prior art, and each of the graphene oxide coating or the reduced graphene oxide coating By establishing optimal process conditions according to the case, coating efficiency and coating stability are secured, and by effectively forming a three-dimensional network structure between graphene oxide and reduced graphene oxide (particles), organic and oil contaminants in water and underground , For example, it effectively sorbs and removes non-polar organic compounds such as phenol compounds, and it has excellent physical and chemical stability and can be reused many times, so it is easy to use and excellent in terms of economic efficiency. Confirmed through experiments, The present invention has been completed.

Sponge type sorbent medium and manufacturing method thereof

Specifically, the method for manufacturing a sponge-type sorbent medium according to an embodiment of the present invention includes the steps of: a) ultrasonically cleaning and drying a sponge; b) immersing the sponge in a graphene solution containing at least one selected from graphene oxide and reduced graphene oxide, and physically squeezing the sponge; c) primary heat treatment of the sponge obtained in step b for 3 to 5 hours; d) ultrasonically cleaning the sponge obtained in step c to remove overcoated particles on the surface of the sponge; and e) subjecting the sponge to a secondary heat treatment for 3 to 5 hours; can include

First, the sponge is ultrasonically cleaned and dried (step a).

In the present invention, a sponge is used as a carrier and may have a porous surface. The sponge according to one embodiment of the present invention may be a polyurethane-based, melamine-based, or polyvinyl alcohol-based sponge, and in the case of the sponge made of the above material, excellent water permeability due to macropores Therefore, when used in a continuous reactor, the filtration resistance is small, and graphene oxide or reduced graphene oxide particles can be stably supported on the surface.

For example, in the above step, a polyurethane sponge is cut into a cube having a size of 1 cm X 1 cm X 1 cm, and then, as a process for effectively removing impurities remaining inside the sponge during the sponge manufacturing process, an acetone solvent, etc. It may be that it proceeds through a process of washing with . Meanwhile, the step may include, after washing to remove impurities, rinsing the sponge with distilled water and completely drying the sponge in a dry oven at 60° C.

Next, the sponge is immersed in a graphene solution containing at least one selected from graphene oxide and reduced graphene oxide, and physically squeezed (step b) .

The step is a process for sufficiently coating graphene oxide or reduced graphene oxide particles on the surface of the sponge, and a simpler dip-coating method may be used compared to the prior art.

When GO or rGO in the form of powder is used in the water treatment process according to the prior art, graphene oxide or reduced graphene oxide may lose its unique properties by restacking in the process of being dried after being dispersed in water. There is a need to fabricate graphene oxide sheets into a solid three-dimensional graphene oxide network sponge. Such a graphene oxide sponge can be used as an excellent adsorbent due to its large accessible pore volume compared to its weight.

Specifically, in the present invention, the graphene oxide or reduced graphene oxide coated on the surface of the sponge may be prepared by a chemical exfoliation method known as Hummer's method or the like. The method is to prepare graphite oxide by reacting graphite with a strong acid and an oxidizing agent, and then inducing exfoliation to produce graphene oxide (GO), which is an oxidized form of graphene. It can be reduced, and when it is reduced, it is produced as reduced graphene oxide (rGO) (see FIG. 1).

Meanwhile, in the present invention, the graphene solution may include at least one selected from graphene oxide and reduced graphene oxide, and for example, a graphene oxide solution or reduced graphene oxide. It may be a pin oxide solution.

In the above step, the graphene oxide or reduced graphene oxide coated on the surface of the sponge forms a π-π interaction with the organic compound in the water or in the ground due to the electrostatic attraction due to the large specific surface area and high electrical conductivity, so that the organic compound in the water or in the ground can be effectively removed (see FIG. 2).

On the other hand, the graphene solution used in the above step may be a graphene solution titrated to a pH in the range of 9 to 10 with an ammonia solution before immersing the sponge. On the other hand, by allowing the graphene solution to be in the above pH range, the degradation of coating stability due to aggregation between graphene oxide or reduced graphene oxide particles in the solution is effectively prevented.

As an example, the step may be to immerse the sponge in a 5 mg / mL GO aqueous solution, and then perform compression and contraction repeatedly using a physical method one or more times, for example, three or more times, such as squeezing ( It is possible to allow the GO or rGO solution to penetrate evenly into the sponge through the squeezing process (see FIG. 3).

On the other hand, in one embodiment of the present invention, when the graphene solution is a graphene oxide (Graphene Oixde) solution, the heat treatment process of steps c and e to be described later may be performed within a temperature range of 50 to 70 ° C., In another embodiment of the present invention, when the graphene solution is a reduced graphene oxide solution, heat treatment processes of steps c and e to be described later may be performed within a temperature range of 90 to 110 ° C. there is.

As described above, when the main components included in the graphene solution are changed, the optimum heat treatment temperature is changed, and this is because the reduced graphene oxide solution containing reduced graphene oxide as a main component is not transformed into a suspension form with increased viscosity. Because. On the other hand, when the temperature of the heat treatment process is varied according to the main components of the graphene solution as described above, it can be seen that the graphene oxide particles or reduced graphene oxide particles are evenly coated on the surface of the sponge in each case (FIG. 5 and see FIG. 6).

On the other hand, the reduced graphene oxide solution used in step b may be obtained by heat-treating the graphene oxide solution within a temperature range of 90 to 110 ° C., and specifically, heat treatment may be performed in a heating mantle or the like. .

Next, the sponge obtained in step b may be subjected to a primary heat treatment for 3 to 5 hours (step c), and the sponge obtained in step c is ultrasonically cleaned to remove overcoated particles on the surface of the sponge (step d) , By subjecting the sponge to a secondary heat treatment for 3 to 5 hours (step e), sponge-type sorption coated with one or more particles selected from graphene oxide particles and reduced graphene oxide particles on the surface and inside of the sponge, which is a carrier, finally. media can be obtained (see Fig. 4).

On the other hand, in the above step, the first and second heat treatment processes may be performed to secure coating stability, and as described above, when the particles coated on the surface and inside of the sponge are graphene oxide particles, the heat treatment process is 50 to 70 ° C., in particular, at 60 ° C., and when the coated particles are reduced graphene oxide particles, the heat treatment process may be performed at a temperature in the range of 90 to 110 ° C., specifically at 100 ° C. can On the other hand, as described above, by varying the heat treatment temperature for expecting surface modification and physical property change according to the type of particle, it is possible to smoothly perform particle coating on the surface and inside of the sponge.

On the other hand, the sponge-type sorbent medium prepared through the above steps is coated with at least one type of particles selected from graphene oxide particles and reduced graphene oxide particles on the surface and inside of the sponge, thereby removing organic and oil contaminants in water and underground. It can be absorbed and removed effectively. Specifically, the sponge-type sorption medium effectively removes organic and oil contaminants by sorbing them on the surface and inside of the pores of the sponge through at least one mechanism selected from surface adsorption, capillary force, and suction. can do.

Meanwhile, as described above, the sponge may be a polyurethane-based sponge, a melamine-based sponge, or a polyvinyl alcohol-based sponge, for example, a polyurethane-based sponge.

In addition, according to an embodiment of the present invention, the sponge-type sorption medium may have a hydrophobic property because the contact angle of the surface of the sorption medium with respect to water is 110 ° or more, and for example, a sponge coated with reduced graphene oxide particles The surface may have a contact angle of about 131°.

In addition, according to an embodiment of the present invention, the sponge-type sorption medium contains 1 to 10% by weight of graphene oxide particles and reduced graphene oxide particles coated on the surface and inside of the sponge based on the total weight of the sorption medium. it could be On the other hand, the coating amount can be increased by repeating steps b to e described above, and has an optimal adsorption amount within the weight% range, and when the weight% is less than the weight%, it is difficult to expect a sufficient adsorption effect, If the weight % is exceeded, there is little increase in adsorption effect, and thus economic feasibility may decrease.

Specifically, the sponge-type sorbent medium according to an embodiment of the present invention may have an adsorption amount (q _e ) of 18 mg / g or more for 24 hours under a pH 4 condition in the water phenol adsorption removal test, and according to another embodiment In the water phenol adsorption removal test, the adsorption amount (q _e ) for 24 hours under pH 7 conditions may be 17 mg / g or more, and according to another embodiment, in the water phenol adsorption removal test, the adsorption amount for 24 hours under pH 10 conditions ( q _e ) may be greater than or equal to 14 mg/g.

Method for sorption and removal of organic and oil contaminants in water and in the ground

On the other hand, according to an embodiment of the present invention, the method for sorbing and removing organic and oil contaminants using a sponge-type sorbent medium as described above is a method for treating organic and oil contaminants in water and underground, and the above-described sponge-type sorption The medium may be introduced into contaminated water to absorb and remove organic compounds or oil pollutants in water or underground, and the organic compound may be a non-polar organic compound, for example, a phenol-based compound. there is.

Example

Since the present invention can have various changes and various forms, specific embodiments are exemplified and described in detail below. However, it should be understood that this is not intended to limit the present invention to the specific disclosed form, and includes all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Example 1

First, a liquid graphene oxide (5 mg/mL) stock solution containing graphene oxide prepared by the Hummer's method was prepared, and then an ammonia solution was used to prevent deterioration in coating stability caused by aggregation between particles. The pH of the stock solution was adjusted to 10 by titration.

The polyurethane sponge was cut into a cube with a size of 1 cm X 1 cm X 1 cm, and ultrasonically washed with an acetone solvent to effectively remove impurities remaining during the sponge manufacturing process, rinsed with distilled water, and dried in a dry oven at 60 ° C. It was prepared by completely drying at high temperature.

Next, after immersing the polyurethane sponge in the prepared storage solution, the physical compression and contraction process was repeated 3 times so that the solution could flow into the sponge, and the sponge was taken out and physically compressed and contracted 3 times again. The GO solution was repeatedly extruded out of the sponge.

Next, coating stability was secured by heat-treating the sponge at a temperature of 60 ° C. for 4 hours (first heat treatment), and after drying, by ultrasonic cleaning in a sonication bath, graphene oxide excessively coated on the surface of the sponge Particles were removed. Thereafter, the sponge was heat-treated again at 60° C. for 4 hours (secondary heat treatment) to obtain a sponge-type sorbent medium (manufactured by PU-GO).

Example 2

A sponge-type sorbent medium was obtained in the same manner as in Example 1, but a reduced graphene oxide solution obtained by heat treatment of the graphene oxide solution in a heating mantle at 100 ° C. for 6 hours was used instead of the graphene oxide solution, 1 The primary and secondary heat treatment processes were only performed by heat treatment under a temperature condition of 100 ° C, respectively (PU-rGO production).

Comparative Example 1

Unlike Example 1, a polyurethane sponge was prepared without any treatment.

[Experiment 1: Measurement of coating properties]

The result of observing the sponge-type sorbent medium prepared according to Example 2 under an optical microscope is shown in FIG. 5 . Referring to FIG. 5, in the case of PU-rGO obtained by performing a heat treatment process at 100 ° C., rGO particles were evenly coated on the surface, and it was confirmed that the amount of coated particles significantly increased compared to the case of heat treatment at a low temperature.

On the other hand, as a result of checking through a scanning electron microscope as shown in FIG. 6, in the case of the rGO solution prepared by heat treatment through UV-Vis, a peak was observed at around 230 nm in the range of 40 to 80 ° C, indicating that the GO form However, in the range of 100 ° C., a peak was observed at a wavelength of around 245 nm, confirming that GO was converted to rGO form.

[Experiment 2: Contact angle measurement]

7 shows the results of evaluating the hydrophobicity of the sponge surface by analyzing the contact angle of the surface of the sponge-type sorption medium prepared in Example 2, and as a result of measuring the contact angle by selecting water as the liquid, it was confirmed that the contact angle was 131 ° Through this, it was confirmed that the sponge-type sorbent medium prepared according to the present invention has a hydrophobic surface.

[Experiment 3: Measurement of phenol adsorption performance in water]

In order to measure the adsorption performance of phenol, an organic compound in water, polyurethane sponges according to Example 2 and Comparative Example 1 were prepared. For reference, the PU-rGO prepared according to Example 2 was used by repeating the above-described process three times to have 6.21% by weight of rGO particles based on the total weight of the sponge-type sorbent medium (see FIG. 8).

The experiment was performed for 24 hours under acidic (pH 4), neutral (pH 7) and basic (pH 10) conditions, respectively, and at this time, phenol was included in water at 10 mg/L. On the other hand, as an index for measuring adsorption performance, the adsorption amount (q _e ) value was derived by the following formula 1.

(계산식 1)

(Calculation 1)

C ₀ : initial concentration of phenol solution (mg/L)

C _e : Equilibrium concentration of phenol solution after adsorption reaction (mg/L)

M : mass of sponge injected into the reaction (mg)

V : volume of phenol solution (L)

The experimental results are shown in FIG. 9, and referring to this, the adsorption amount (q _e ) of the PU sponge according to Comparative Example 1 was 11.3 mg/g (pH 4 condition) and 11.8 mg/g (pH 7) for each pH, respectively. condition), and 8.9 mg/g (pH 10 condition), and the adsorption amount (q _e ) value of the PU-rGO sponge according to Example 2 was 18.2 mg/g (pH 4 condition) and 17.4 for each pH, respectively. It was confirmed that the values were mg/g (pH 7 condition) and 14.5 mg/g (pH 10 condition). Through this, in the case of the sponge-type sorption medium prepared according to Example 2, compared to Comparative Example 1, the adsorption performance is improved by about 61.1% under pH 4 conditions, about 47.5% under pH 7 conditions, and about 62.9% under pH 10 conditions, respectively. could confirm that

In addition, it was confirmed that the PU-rGO sponge prepared according to the present invention is physically and chemically stable and can be reused several times.

In the foregoing, although specific embodiments of the present invention have been described and illustrated, it is common knowledge in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. It is self-evident to those who have Therefore, such modifications or variations should not be individually understood from the technical spirit or viewpoint of the present invention, and modified implementations should belong to the claims of the present invention.

Claims (15)

a) ultrasonically cleaning and drying a polyurethane-based sponge;
b) immersing the sponge in a reduced graphene oxide solution and physically squeezing it;
c) primary heat treatment of the sponge obtained in step b in a temperature range of 90 to 110 ° C for 3 to 5 hours;
d) ultrasonically cleaning the sponge obtained in step c to remove overcoated particles on the surface of the sponge; and
e) subjecting the sponge to a second heat treatment in a temperature range of 90 to 110 ° C for 3 to 5 hours; A method for producing a sponge-type sorbent medium comprising a. According to claim 1,
Wherein the reduced graphene oxide solution in step b is titrated with an ammonia solution to a pH in the range of 9 to 10, a sponge-type sorbent medium manufacturing method. delete According to claim 1,
The reduced graphene oxide solution of step b is obtained by heat-treating the graphene oxide solution within a temperature range of 90 to 110 ° C., a sponge-type sorbent medium manufacturing method. delete A sponge-type sorbent medium prepared according to the method of claim 1,
The sorbent medium is a sponge-type sorbent medium in which reduced graphene oxide particles are coated on the surface of a polyurethane-based sponge in an amount of 1 to 10% by weight based on the total weight of the sponge-type sorbent medium. delete According to claim 6,
The sponge-type sorption medium, wherein the surface of the sponge-type sorption medium has a contact angle with respect to water of 110 ° or more. delete According to claim 6,
The sponge-type sorbent medium sorbs organic and oil contaminants in water and underground to the surface and inside the pores of the sponge through at least one mechanism selected from surface adsorption, capillary force, and suction. sorbent medium. According to claim 6,
The sponge-type sorption medium has an adsorption amount (q _e ) of 18 mg / g or more for 24 hours under pH 4 conditions in the water phenol adsorption removal test. According to claim 6,
The sponge-type sorption medium has an adsorption amount (q _e ) of 17 mg / g or more for 24 hours under pH 7 conditions in the water phenol adsorption removal test. According to claim 6,
The sponge-type sorption medium has an adsorption amount (q _e ) of 14 mg / g or more for 24 hours under a pH 10 condition in the water phenol adsorption removal test. As a method for treating organic and oil pollutants in water and underground, the sponge-type sorbent medium of claim 6 is injected into contaminated water,
A method for sorbing and removing organic and oil pollutants by sorbing and removing organic compounds or oil pollutants in water or in the ground. 15. The method of claim 14,
The organic compound is a phenol-based compound, organic and oil contaminant sorption removal method.

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