JP2014213218A - Absorbent of harmful matter in circumstance and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adsorption medium that is the harmful matter adsorption medium in which a harmful matter from circumstance is removed with high efficiency, and concentration and volume reduction are performed, and the harmful matter is not leaked even under a severe circumstance condition.SOLUTION: A harmful matter absorbent of Prussian blue or the like is included in a gel of calcium alginate or the like and further subjected to epoxy crosslink, so that a harmful matter adsorption medium in which physical strength, chemical resistance, and antiweatherability are excellent is prepared.

Description

  Removal of harmful substances discharged into the environment is a big problem. It has been a big problem for the past to remove harmful substances such as heavy metals contained in factory effluent and to reduce the level without affecting the environment.

  In addition, due to the accident at the Fukushima nuclear power plant, radioactive material decontamination work is currently being carried out in various places in Fukushima Prefecture, and removal of radioactive materials in the environment has become a new problem. Therefore, it is important to remove radioactive waste with high efficiency.

  In connection with this, the storage of radioactive waste has emerged as a new problem. Because of the large amount of radioactive material released in the accident, even if an intermediate treatment facility and final treatment facility are built and radioactive waste removed from the environment is stored there, the radioactive material is concentrated and the capacity is reduced. It is necessary. Furthermore, it is important to fix radioactive materials so that they are not re-released into the environment, and to store them safely at high density.

  At present, adsorbents that adsorb radioactive substances such as Prussian blue, zeolite, activated carbon and the like are used for removing and immobilizing radioactive substances. These adsorbents disperse well in the liquid phase when used as fine powder particles, but adsorb large amounts of radioactive material, but it is difficult to recover adsorbents that have adsorbed radioactive material after use. It ’s hard to handle.

  Also, during use, adsorbents such as Prussian blue elute from the adsorbent, such as iron, or harmful substances such as radioactive substances once adsorbed to the adsorbent are released again into the dispersion medium. There are concerns. If such a situation occurs, not only will the efficiency of removal and immobilization decrease, but it may also have a serious impact on the environment.

  Conventionally, a waste liquid treatment method for removing heavy metals and radionuclides by manufacturing a capsule in which an adsorbent is encapsulated with alginic acid and confining a harmful substance in the adsorbent in the microcapsule is known (Patent Documents 1 to 3). .

  However, the microcapsules described in these patent documents have low mechanical strength, and when the volume is reduced by pressing or the like, there is a risk that harmful substances contained in the gel leak together with the adsorbent. Therefore, there is a serious problem in disposal of a large amount of radioactive material with a reduced capacity.

  In addition, the microcapsules described in these patent documents are inferior in chemical resistance to various chemicals typified by acids, bases, salts, and organic solvents, so that they can adsorb toxic substances in harsh environments. There is a problem and elution of microcapsule components may occur in a liquid with low osmotic pressure such as pure water.

  In addition, the ability of these microcapsules to adsorb and remove harmful substances correlates with the amount of adsorbent contained, but this is not an examination of how much adsorbent can be encapsulated without the risk of leakage of harmful substances. It has not been done until. In addition, there has been no discussion about improvement in chemical resistance and osmotic pressure resistance.

JP 2007-14841 A JP-A-11-70384 JP 2011-47665 A

  An object of the present invention is to make the adsorbent used for removing and immobilizing harmful substances such as radioactive substances into an easy-to-handle shape without impairing the adsorption performance. In addition, while maximizing the ability to adsorb harmful substances, it prevents harmful substances from being released again from the adsorbent and prevents the adsorbent from leaking, and prevents the adsorbent components from eluting from the dispersion medium. It is an object to provide an adsorption medium in which no substance is released.

  It is another object of the present invention to provide an adsorption medium having chemical resistance and osmotic pressure resistance that can act in various environments.

  Furthermore, the present invention provides an adsorbent that can be reduced in volume, which is currently a problem in storage and disposal of radioactive materials, by concentrating the radioactive materials in the environment to a high concentration and then increasing the density. Let it be an issue.

  The present invention is a method for producing a harmful substance adsorption medium, a dispersion step of adding and dispersing a harmful substance adsorbent in a solution containing at least one gelling component comprising a polysaccharide or a polypeptide forming a gel; And a gelling step of gelling the entire solution after dispersing the harmful substance adsorbent, wherein the weight ratio of the harmful substance adsorbent to the gelling component is 1 to 100.

  By including the harmful substance adsorbent in a gel formed of polysaccharides or polypeptides, the outflow of the harmful substance adsorbent and the harmful substance adsorbed on the adsorbent can be significantly reduced. The amount of the harmful substance adsorbent contained in the gel correlates with the amount of the harmful substance that can be adsorbed by the harmful substance adsorption medium. Therefore, if more adsorbent can be contained, more harmful substances can be adsorbed. As a result of intensive studies on the amount of the adsorbent that can be added to the gelling component, the present inventors have determined that the harmful substance adsorbent is distributed at a distribution ratio of 99% or more if the weight ratio is 100 with respect to the gelling component. It was revealed that the gel can be included.

  Further, within this weight ratio range, leakage of the adsorbent and elution of harmful substances hardly occur and can be handled safely.

  Further, the present invention is characterized in that a harmful substance adsorbing medium having magnetism is produced by further adding a magnetic substance in the dispersing step.

  By using a harmful substance adsorption medium containing a magnetic substance, it can be recovered by a magnet and dispersed in a solution containing the harmful substance, and can be easily recovered after sufficiently adsorbing the harmful substance. Further, since the recovery is performed by magnetic force, there is little possibility that an operator directly touches harmful substances, and the safety of handling can be ensured.

  Furthermore, the present invention is characterized in that a harmful substance adsorbing medium having a chemical sensor function is manufactured by adding a chemical substance that varies depending on pH and / or a chemical substance that varies depending on radiation dose.

  By providing the chemical sensor function, it is possible to easily determine the allowable adsorption amount of the harmful substance while using the harmful substance adsorption medium, and it is possible to efficiently remove and immobilize the harmful substance.

  In addition, the present invention is characterized by including a step of obtaining an epoxy-crosslinked gel by allowing a diepoxy compound or a polyepoxy compound to act.

  Since the surface of the gel or the entire gel is epoxy-crosslinked, a harmful substance-adsorbing medium having a chemically and physically increased strength can be obtained. Therefore, it is possible to produce a very stable harmful substance adsorption medium, and weather resistance and chemical resistance are increased compared to conventional adsorption media, so various substances present in the environment and environmental conditions such as temperature It is very safe because it does not leak harmful substances again and the adsorbent itself does not leak into the environment.

  Furthermore, the production method of the present invention is characterized in that the harmful substance adsorption medium is dried after the production of the harmful substance adsorbent or after the epoxy crosslinking.

  The harmful substance adsorption medium of the present invention can be reduced in volume and volume by drying. By dispersing in a solution containing a harmful substance at the time of use, it absorbs water again and returns to the capacity before drying, and also functions as a harmful substance adsorption medium. Therefore, when a large amount of harmful substance adsorption medium is used, it is necessary to prepare a reduced amount of adsorption medium that has been dried in advance. Can also be reduced.

  The harmful substance adsorption medium of the present invention is a harmful substance adsorption medium containing a harmful substance adsorbent and a gelling component containing a polysaccharide or a polypeptide, wherein the weight ratio of the harmful substance adsorbent to the gelling component is Is 1 to 100.

  As a result of the study by the present inventors, it is clear that a safe harmful substance adsorbent in which the adsorbent is encapsulated in the gel can be produced even if a harmful substance adsorbent of up to 100 weight ratio is added to the gelling agent. became. By including the harmful substance adsorbent in the gel, the harmful substance can be contained in the gel and can be handled safely.

  In addition, the harmful substance adsorption medium of the present invention is characterized by containing a magnetic substance.

  By containing a magnetic substance, it can be recovered by a magnetic force after adsorbing a harmful substance, so that not only can it be easily recovered, but also safety in handling is increased.

  Furthermore, the harmful substance adsorption medium of the present invention is characterized by containing a chemical substance that varies with pH and / or a chemical substance that varies with radiation dose.

  By providing the harmful substance adsorption medium itself with a chemical sensor function, it is possible to easily determine the replacement time, the recovery time, etc. of the harmful substance adsorption medium, so that the harmful substance can be efficiently removed from the environment.

  The harmful substance adsorption medium of the present invention is characterized in that it contains a harmful substance adsorbent, a gel-forming component containing polysaccharides or polypeptides, and an epoxy cross-linking component comprising a diepoxy compound or a polyepoxy compound.

  The physical and chemical strength can be increased by further epoxy-crosslinking a harmful substance adsorption medium comprising a harmful substance adsorbent and a gelling component. Therefore, harmful substances can be safely removed even under severe environmental conditions.

  The present invention also relates to a method for using the above-mentioned harmful substance adsorption medium, comprising the steps of adsorbing and removing the harmful substance by bringing the harmful substance into contact with the harmful substance adsorption medium, and the harmful substance adsorbing the harmful substance. And a step of squeezing or drying the substance adsorbing medium.

  According to the present invention, after adsorbing and fixing the harmful substance, the harmful substance adsorbing medium is squeezed or dried to enclose the harmful substance in the gel while adsorbed on the harmful substance adsorbent and reduce the volume. It becomes possible. The ability to adsorb harmful substances present in the environment and further reduce the volume after immobilization means that harmful substances such as radioactive substances can be concentrated at high density. Although storage of a large amount of radioactive waste by decontamination is an important problem, the harmful substance adsorption medium of the present invention can be one of the promising solutions.

  Further, the present invention is a method for adsorbing harmful substances, wherein at least one gelling component comprising a polysaccharide or a polypeptide forming a gel and a harmful substance adsorbent are added to a solution containing the harmful substances to adsorb the harmful substances. An adsorption / dispersion step for dispersing the harmful substance adsorbent while adsorbing the harmful substance to the agent, and a gelation step for gelling the entire solution in which the harmful substance is adsorbed on the harmful substance adsorbent, The weight ratio of the harmful substance adsorbent to the gelling component is 1 to 100.

  According to the harmful substance adsorption method of the present invention, it is possible to drain a solution containing no harmful substances by separating the gel containing the harmful substances from the solution containing the harmful substances by filtration or centrifugation. Become.

  Furthermore, the harmful substance adsorption method of the present invention includes a step of allowing a diepoxy compound or a polyepoxy compound to act on a gel containing a harmful substance adsorbent adsorbed with the harmful substance to obtain an epoxy-crosslinked gel. To do.

  By using an epoxy-crosslinked gel, harmful substances can be safely removed from the environment without leakage.

  Hereinafter, the present invention will be described in detail with reference to examples. In the examples, Prussian blue is used as the adsorbent and sodium alginate is used as the gel, but it is needless to say that the adsorbent can be appropriately selected depending on the target substance to be removed from the environment.

  For example, if the purpose is removal of radioactive substances, Prussian blue analogs such as Prussian blue and Prussian blue cobalt substitution, zeolite, activated carbon, insoluble calcium salts, and minerals containing them as main components can be used.

  For the purpose of removing heavy metals and arsenic, activated carbon, insoluble calcium salts and minerals based on them as adsorbents, silica gel, mesoporous materials represented by mesoporous silica, clay, etc., organophosphorus compounds, organic For the purpose of removing harmful organic substances such as agricultural chemicals represented by halogen compounds, dioxins and simazine, activated carbon, insoluble calcium salts and minerals based on them, silica gel, mesoporous materials represented by mesoporous silica Etc. can be used.

  Moreover, although sodium alginate is used as a gel in the present invention, any material may be used as long as it is a substance that gels and includes the adsorbents listed above. Examples of polysaccharides that can be used as a gel in addition to sodium alginate include alginic acid, alginate, carrageenan, agarose, carboxymethylcellulose, carboxymethylcellulose salt, and the like. Polypeptides include polyglutamic acid and the like.

[Production of adsorbent-containing gel]
(1) Production of Prussian blue-containing gel 0.20 g of Prussian blue is added to 20 g of a 1.0% by weight aqueous sodium alginate solution, and uniformly dispersed by stirring and ultrasonic irradiation. By dropping this dispersion into 100 ml of a 20% by weight calcium chloride aqueous solution, a hydrogel containing Prussian blue is obtained.

(2) Manufacture of gel containing Prussian blue and magnetic substance To 20 g of 1.0% by weight sodium alginate aqueous solution, 0.20 g of Prussian blue and 1.0 g of magnetic substance are added, and uniform by stirring and ultrasonic irradiation. Disperse. By dropping this dispersion into 100 ml of a 20% by weight calcium chloride aqueous solution, a hydrogel containing Prussian blue is obtained.

  The magnetic material used here is magnetite, but well-known magnetic materials such as maghematite, ferrite, barium ferrite can be used.

(3) Production of zeolite-containing gel 0.20 g of zeolite is added to 20 g of 1.0 wt% sodium alginate aqueous solution, and the mixture is uniformly dispersed by stirring and ultrasonic irradiation. By dropping this dispersion into 100 ml of a 20% by weight calcium chloride aqueous solution, a hydrogel containing Prussian blue is obtained.

(4) Production of Gel Containing Zeolite and Magnetic Material 0.20 g of zeolite is added to 20 g of 1.0 wt% sodium alginate aqueous solution, and uniformly dispersed by stirring and ultrasonic irradiation. By dropping this dispersion into 100 ml of a 20% by weight calcium chloride aqueous solution, a hydrogel containing Prussian blue is obtained.

  Here, a method of creating a gel that contains a magnetic substance in addition to an adsorbent and can be collected by magnetic force is shown. By adding a chemical substance that changes depending on pH and radiation dose in addition to the magnetic substance, It is also possible to create an adsorption medium having a sensor function.

  Examples of chemical substances that change with pH include acid-base indicators such as thymol blue, methyl red, bromothymol blue, and phenolphthalein. Examples of chemical substances that change with radiation dose include xylenol orange, chloroauric acid, and the like. Salts, benzophenones, mixtures of Prussian blue and dihydroxybenzoquinones, etc. are known. By including these substances, it is possible to know with the naked eye how much the harmful substances have been adsorbed to the adsorption medium, and therefore it is possible to easily know the replacement time of the adsorption medium.

[Examination of incorporation of adsorbent into gel]
As described above, even when Prussian blue was used as the adsorbent or zeolite was used, an adsorbing medium including the adsorbent could be prepared. The amount of adsorbent encapsulated in the gel correlates closely with the amount of harmful substances that the adsorption medium can adsorb. Therefore, in order to examine the amount of adsorbent that can be included in the gel, an adsorbent was added and the distribution ratio of the adsorbent distributed to the gel was examined.

  A predetermined amount of Prussian blue was added to 20 ml of a 1.0 wt% aqueous sodium alginate solution and stirred, and then subjected to dispersion for 2 minutes by ultrasonic irradiation. Next, 100 ml of a 20% by weight calcium chloride aqueous solution is prepared and added dropwise to the sodium alginate aqueous solution while stirring at 100 rpm using a magnetic stirrer. As soon as the aqueous calcium chloride solution is dropped, spheres of calcium alginate containing Prussian blue are obtained. Table 1 shows the amount of Prussian blue added when actually preparing the gel and its weight ratio to sodium alginate.

  The gel containing Prussian blue obtained by the above method (hereinafter referred to as Prussian blue gel) is filtered and weighed. Further, Prussian blue remaining in the aqueous solution was quantified by a colorimetric method, and the amount of Prussian blue distributed to the gel was estimated. Table 2 shows the results.

  From the above results, it was confirmed that up to 50 times the weight ratio of sodium alginate can include 99.9% or more of the adsorbent, and even 100 times can include 99.8% of the adsorbent. . This indicates that a very large amount of adsorbent can be included in sodium alginate, and that an adsorption medium having a high adsorption capacity can be formed. Further, by gelling, it can be formed into a desired shape such as a bead shape or a plate shape, and can be formed into a shape convenient for processing after adsorbing a harmful substance.

  When the weight ratio exceeded 100, the entire amount of the adsorbent was not taken into the capsule. However, as shown in Example 7, if the weight ratio is 100, 99.8% of the adsorbent is included, so that the weight ratio of the harmful substance adsorbent to the gelled component is 1 to 100. Thus, a highly practical adsorption medium can be manufactured.

[Prussian blue leakage test]
If Prussian blue leaks from the prepared gel, harmful substances such as radioactive substances adsorbed on Prussian blue will also leak. Then, it was examined next whether leakage of the inclusion Prussian blue occurred after gelation.

  3.0 g each of wet Prussian blue gels of Examples 1 to 6 in 100 ml of distilled water, shake with a constant temperature shaker at 30 ° C., 100 rpm, 240 hours, and then filter the Prussian blue gel. Prussian blue in the phase was quantified by a colorimetric method, and leakage of Prussian blue was analyzed. The results are shown in Table 3.

  In the Prussian blue gel of Example 6 in which Prussian blue was contained 50 times by weight with respect to sodium alginate, the Prussian blue leakage rate was 0.17%, which was a very low leakage rate of 1/500 or less. . Therefore, even if Prussian blue, which is an adsorbent, is used in an amount about 50 times that of sodium alginate, which is a gelling agent, a safe adsorption medium having a very low leakage rate can be produced.

  In Example 2 in which the adsorbent was contained 10 times by weight with respect to sodium alginate, Prussian blue in the liquid phase was below the detection limit, and no leakage was observed. Therefore, if the amount of adsorbent is about 10 times that of the gelling agent, a safer adsorbing medium can be produced.

  Furthermore, a leakage test was performed in consideration of use in the environment using the Prussian blue gel of Example 2 in which no leakage of Prussian blue into distilled water was detected. The test was conducted under the same conditions as the Prussian blue leakage test using distilled water except that an aqueous solution (5% by weight sodium chloride aqueous solution) simulating seawater was used instead of distilled water. As a result, leakage of Prussian blue from the gel was not detected even in the case of an aqueous sodium chloride solution, as in the case of distilled water. Therefore, it was confirmed that it is a safe adsorption medium that does not leak even in the environment.

[Iron ion dissolution test]
Prussian blue contains iron as a chemical composition, but iron ions are often substituted. If iron ions leak from Prussian blue into the environment when using an adsorbing medium, it may be a secondary environmental problem. Thus, not only the adsorbent, but also leakage of iron ions contained in the adsorbent was examined.

After each 3.0 g of wet Prussian blue gel of Examples 1 to 6 above was put into 100 ml of distilled water and shaken at 30 ° C., 100 rpm for 240 hours with a constant temperature shaker, the Prussian blue gel was filtered off. The iron ions in the liquid phase were simply quantified with a total iron ion (Fe ²⁺ / Fe ³⁺ ) test paper. Table 4 shows the iron ion concentration in the liquid phase.

  As shown by the above results, the leakage of iron ions is 1 ppm or less in any Prussian blue gel and is very small, so there is no possibility of causing a new environmental problem.

[Radiocesium adsorption test]
An actual waste sample contains various substances in addition to radioactive substances, and is expected to compete with the radioactive substances. Therefore, these mixed substances may cause adsorption inhibition with respect to an adsorbent such as Prussian blue. Therefore, we examined how much radioactive materials could be removed using actual waste samples.

  Water is added to the incineration fly ash discharged from the general waste incineration disposal site, and after stirring for 6 hours at 200 rpm, the particles are allowed to stand for 30 minutes to settle, and then filtered through a membrane filter, thereby radioactive cesium. Contaminated water (1600 Bq / l, total iron ion concentration of 1 ppm or less) was prepared. Next, 3.0 g of wet Prussian blue gel of each of Examples 1, 3, 5, and 6 was added to 100 ml of the radioactively contaminated water, and shaken at 30 ° C., 100 rpm for 3 hours with a constant temperature shaker. After removing the gel, the radioactive cesium content of the contaminated water was quantified with a germanium semiconductor detector. The results are shown in Table 5.

  Radioactive cesium contaminated water after treatment was below the detection limit, and it was confirmed that radioactive cesium can be removed with high efficiency even in actual environmental samples.

  In particular, even the Prussian blue gel of Example 1 with a small amount of Prussian blue added, the radioactive cesium concentration after treatment is below the detection limit, so that radioactive cesium can be removed from contaminated water very efficiently. It has been shown.

[Radiocesium re-elution test]
When toxic substances such as radioactive cesium were eluted again from the adsorption medium after adsorption, harmful substances would be released again into the environment, causing problems. .

  In the above radioactive cesium adsorption test, 100 ml of distilled water was added to Prussian blue gel adsorbed with radioactive cesium, and the mixture was shaken at 30 ° C., 100 rpm for 3 hours with a constant temperature shaker to measure radioactive cesium in the liquid phase. A dissolution test was performed. The results are shown in Table 6.

  As a result of the re-elution test, any radioactive cesium in the eluate was below the detection limit, and no re-elution of radioactive cesium was observed.

  As described above, a gel containing an adsorbent has a high ability to adsorb harmful substances, and does not cause leakage of adsorbents or elution of harmful substances. However, the harmful substance adsorption medium must be able to withstand extreme use conditions such as being exposed to severe weather conditions in the environment or being used in contaminated water with extreme pH and the like.

  In the present invention, the gel containing the adsorbent was further epoxy-crosslinked with a diepoxy compound or a polyepoxy compound to produce a harmful substance adsorbing medium having increased physical strength and chemical strength.

[Creation of epoxy cross-linked harmful substance adsorption medium]
-0.20 g of Prussian blue is added to 20 g of a 0% by weight sodium alginate aqueous solution, and is uniformly dispersed by stirring and ultrasonic irradiation. The dispersion was dropped into 100 ml of a 20 wt% calcium chloride aqueous solution to obtain a hydrogel containing Prussian blue. The obtained gel was washed with pure water to remove unbound calcium. The obtained gel was dispersed in a solvent, and 1,2,7,8-diepoxyoctane was added in the presence of a catalyst to react at room temperature. The gel was washed three times with acetone / pure water and isopropyl alcohol / pure water to obtain a crosslinked gel.

  In addition to 1,2,7,8-diepoxyoctane, alkane diglycidyl ether, alkene diglycidyl ether, alkanediol diglycidyl ether, alicyclic diepoxide, and the like can be used.

[Investigation of chemical resistance of epoxy cross-linked harmful substance adsorption medium]
The chemical resistance of the epoxy-crosslinked harmful substance adsorption medium of the present invention was examined.

  The aforementioned non-crosslinked and crosslinked harmful substance adsorption medium was immersed in 3M aqueous sodium hydroxide solution and 3M hydrochloric acid. Observation was performed 100 hours after standing at room temperature. As a result, Prussian blue was not eluted in the non-crosslinked harmful substance adsorption medium, but in the sample in sodium hydroxide, the solution became cloudy due to the decomposition of alginic acid and the liquid color changed to yellow. In addition, when observed in 3M hydrochloric acid after 300 hours, the harmful substance-adsorbing medium was embrittled. On the other hand, no such change was observed for the epoxy cross-linking harmful substance adsorption medium.

  In addition, when the sample was left in pure water and observed after 300 hours, a slight change in hardness was observed in the non-crosslinked harmful substance adsorption medium. I couldn't.

  As shown in the above result, the chemical resistance of the adsorption medium is enhanced by the epoxy crosslinking. Although the hazardous substance adsorption medium of the present invention is assumed to be used in various environments, the hazardous substance adsorbent of the present invention is harmful without re-eluting the adsorbed hazardous substance even under severe environmental conditions. It is possible to retain and concentrate the substance.

[Volume reduction of harmful substance adsorption medium]
The harmful substance adsorption medium of the present invention can be reduced in volume by removing a solvent such as moisture by squeezing or drying.

  The microcapsule of Example 1 was put in the cylinder part of the syringe, and the pressing rate was measured by pushing the plunger.

As a result, the microcapsules having a bulk volume of 2.5 cm ³ were compressed to 20%, and the bulk volume was 0.50 cm ³ . At this time, the mass was compressed to 42% and decreased from 1.88 g to 0.80 g.

  In the drying test, 2.5 g of microcapsules lost weight to 20%, resulting in a weight of 0.50 g, and the microcapsules were cured. The microcapsules after curing were redispersed in an aqueous solvent and shaken for 3 hours, but no Prussian blue spill was observed.

  As mentioned above, after manufacturing the harmful substance adsorption medium, the method of adsorbing the harmful substance and removing the harmful substance has been described. However, the method of the present invention is a polysaccharide or poly- saccharide that directly forms a gel in the solution containing the harmful substance. It is also possible to add a gelling component such as peptides and a harmful substance adsorbent, perform gelation, and remove the harmful substance by adsorption.

  Depending on the amount and location of the solution containing the toxic substance, the toxic substance can be removed by adding the toxic substance adsorbent and the gelling component directly, and the toxic substance can be removed by a simple method. Even in this case, by further epoxidizing the gel containing the harmful substance adsorbent to which the harmful substance has been adsorbed, a structure in which the harmful substance does not easily leak from the gel is obtained.

  The harmful substance adsorption medium of the present invention adsorbs harmful substances with high efficiency, does not cause elution, and is excellent in weather resistance, chemical resistance and the like. Furthermore, since it can be formed in any shape, it is very easy to handle. Further, since the volume can be reduced by squeezing, drying, etc. after adsorbing harmful substances, it is an excellent medium for long-term storage such as storage of radioactive substances.

  As described above, the adsorption medium using mainly Prussian blue as an adsorbent and calcium alginate gel has been shown, but it goes without saying that the adsorbent and the gelling agent can be selected and removed depending on the object to be removed from the environment. .

Claims (16)

A method for producing a harmful substance adsorption medium,
A dispersion step of adding and dispersing a harmful substance adsorbent in a solution containing at least one gelling component comprising a polysaccharide or a polypeptide forming a gel;
A gelling step of gelling the entire solution after dispersing the harmful substance adsorbent,
A method for producing a harmful substance adsorption medium, wherein the weight ratio of the harmful substance adsorbent to the gelled component is 1 to 100. A method for producing the harmful substance adsorption medium according to claim 1,
A method for producing a harmful substance adsorbing medium comprising magnetism by further adding a magnetic substance in the dispersing step. A method for producing the harmful substance adsorption medium according to claim 1, comprising:
A method for producing a harmful substance-adsorbing medium having a chemical sensor function by adding a chemical substance that varies depending on pH and / or a chemical substance that varies depending on radiation dose. The method for producing a harmful substance adsorption medium according to any one of claims 1 to 3,
A method for producing an epoxy-crosslinked harmful substance adsorption medium, comprising a step of allowing a diepoxy compound or a polyepoxy compound to act on the harmful substance adsorption medium to obtain an epoxy-crosslinked gel. The method for producing a harmful substance adsorption medium according to any one of claims 1 to 3,
A method of drying a harmful substance adsorption medium after the production of the harmful substance adsorption medium. The method for producing an epoxy-crosslinked harmful substance adsorption medium according to claim 4,
After the epoxy crosslinking, the epoxy-crosslinked harmful substance adsorption medium is dried. A toxic substance adsorbent,
A harmful substance adsorption medium comprising a gelling component containing polysaccharides or polypeptides,
A harmful substance adsorption medium, wherein a weight ratio of the harmful substance adsorbent to a gelling component is 1 to 100. The harmful substance adsorption medium according to claim 7,
A harmful substance adsorption medium comprising a magnetic material. A harmful substance adsorption medium according to claim 7 or 8,
A hazardous substance adsorbing medium comprising a chemical substance changing with pH and / or a chemical substance changing with radiation dose. The harmful substance adsorption medium according to any one of claims 7 to 9, comprising an epoxy crosslinking component comprising a diepoxy compound or a polyepoxy compound. A harmful substance adsorption medium according to any one of claims 7 to 9,
A harmful substance adsorption medium, which is dried after the production of the adsorption medium. The epoxy-crosslinked harmful substance adsorption medium according to claim 10,
An epoxy-crosslinked harmful substance adsorption medium characterized by drying after epoxy-crosslinking. A method for using the harmful substance adsorption medium according to any one of claims 7 to 9 or 11,
A process of adsorbing and removing harmful substances by bringing them into contact with the harmful substance adsorption medium;
A method of using the harmful substance adsorption medium, comprising a step of pressing or drying the harmful substance adsorption medium adsorbing the harmful substance. A method for using the epoxy-crosslinked harmful substance adsorption medium according to claim 10, comprising:
A process of adsorbing and removing harmful substances by bringing the harmful substances into contact with the epoxy cross-linked harmful substance adsorption medium,
A method of using an epoxy-crosslinked hazardous substance adsorption medium, comprising a step of pressing or drying the epoxy-crosslinked harmful substance adsorption medium adsorbing the harmful substance. A harmful substance adsorption method,
Add at least one gelling component consisting of polysaccharides or polypeptides that form a gel and a harmful substance adsorbent to a solution containing the harmful substance, and adsorb the harmful substance to the harmful substance adsorbent, Adsorption / dispersion step of dispersing
A gelation step of gelling the entire solution in which the harmful substance is adsorbed on the harmful substance adsorbent,
The harmful substance adsorption method, wherein the weight ratio of the harmful substance adsorbent to the gelled component is 1 to 100. The harmful substance adsorption method according to claim 15,
In the gel containing the harmful substance adsorbent adsorbed by the harmful substance,
A method for adsorbing harmful substances, comprising a step of allowing a diepoxy compound or a polyepoxy compound to act to obtain an epoxy-crosslinked gel.