JP6176636B2 - Mesoporous silica supporting iodine ion adsorbing compound, iodine ion collector and iodine recovery method using the same - Google Patents

Description

The present invention relates to mesoporous silica having a regular arrangement carrying an iodine ion-adsorbing compound capable of selectively adsorbing iodine ions as a target element, and has recently become a problem. Iodine ions contained in an iodine ion-dissolved solution using an iodine ion collector using mesoporous silica supporting an iodine ion adsorbing compound capable of collecting and recovering radioactive iodine, and an iodine ion adsorbing compound supported on mesoporous silica It is related with the method of collect | recovering efficiently and selectively. Furthermore, the present invention relates to an iodine ion collector and sensor using mesoporous silica for detecting iodine ion concentration.

Iodine (element symbol I) is a familiar element that is frequently used as a reagent that can easily detect starch by the iodine starch reaction and is often used as a disinfectant. It is also an essential element for human beings used to synthesize thyroid hormones in the body. Since iodine is contained in seawater at about 0.05 ppm, the estimated amount of resources is enormous. However, since the concentration is low, it is difficult to recover iodine from seawater. Currently industrially produced as a by-product of natural gas, chili nitrate and petroleum. The world's iodine production is about 25,500 tons (2005), with Chile as the first production, second in Japan, and exports overseas.

As mentioned above, iodine is an element that is useful to the human body and is one of the few valuable export resources in Japan. However, since iodine is an element that easily accumulates in the human body, radioactive iodine, which is a radioactive element in the environment, has recently been released. It is a problem. For example, in the accident at the Chernobyl nuclear power plant, fission products ¹³¹ I (radioisotope) were released in large quantities, which accumulated in the thyroid gland, resulting in frequent thyroid cancer in the population. Recently, the Fukushima nuclear power plant was damaged by the tsunami caused by the Great East Japan Earthquake, and a large amount of radioactive material was released into the environment. Among them, there is concern about the effect of radioactive iodine on the human body. In addition, leakage from the reactor during normal operation into the environment is becoming a problem.

Iodine 129 and iodine 131 are gaseous fission products formed in the fuel rod during the fission process. If the chemical reaction in the reactor is not carefully controlled, the chemical reaction proceeds rapidly, the furnace pressure rises, and fuel rod corrosion occurs. When a fuel rod becomes old, there is a risk that the fuel rod will be broken by cracks or holes. The cracked fuel rods release radioactive iodine into the water that is cooling around the fuel rods. The radioactive iodine circulates in the system together with the cooling water, and eventually goes out of the reactor into the air or other environment, or becomes liquid waste and solid waste. Occasionally, the reactor gas capture system releases a gas containing iodine to the environment.

A large amount of waste (waste water) containing radioactive elements is a big problem for the natural environment, and it has an adverse effect on human beings, plants and animals. (Non-Patent Document 1) The risk received from iodine exposure is further increased by the tendency of iodine to accumulate in the thyroid. (Non-patent document 2) For example, iodine moves from soil to groundwater. When ingested or inhaled, iodine is concentrated in the thyroid mucosa, increasing the risk of carcinogenicity. (Non-Patent Documents 3 and 4) Among all separation methods, adsorption with a selective adsorbent has been frequently used to remove radioactive elements, but no simple and inexpensive method has yet been found, The detection limit of the adsorbent is also much higher than the human limit. (Non-Patent Document 5)

On the other hand, a visual collector (collecting agent) is important for accurately and quickly detecting a target element. The visual inspection approach is effective because it is a simple technique that does not require complex equipment or a well-controlled environment. (Non-Patent Document 5) However, regarding low-concentration level iodine, a visual collector that is low in cost, has good selectivity, can be detected quickly, and can remove radioactive iodine has not been developed at all.

Radioactive iodine is present at concentrations well below the extraction limits of most commonly used processing methods, and the acceptable level of radioactive iodine in the human body is so low that iodine can be detected accurately at the ppb-ppm level. There is a worldwide demand to discover materials that have good selectivity and can be extracted quickly. Furthermore, there is a need for rapid, cost-effective, easy-to-use and reliable techniques for measuring and extracting trace amounts of iodine ion concentration.

On the other hand, various methods for detecting metal ions using mesoporous silica have been studied. For example, in Patent Documents 1 and 2, a composite sensor is formed by holding dye molecules such as aminoporphyrin, dithizone, porphyrin sulfone, etc. on mesoporous silica, and Cd ions, mercury ions, Cr ions, etc. are adsorbed on the dye molecules, It is described that the ion concentration is detected using the spectral change. However, none of the previous patent documents and non-patent documents so far discloses a simple, rapid and accurate method for recovering iodine adsorbed on mesoporous silica.

JP2007-327886A JP2007-327887A

S. Reardon, Fukushima radiation creates unique test of marine life ’s hardiness, Science, 2011, 332, 292. Human health effects-WANMEC and USEPA, 2011 E. Bascetin, G. Atun, Adsorptive removal of strontium by binary mineral mixture of montmorillonite and zeolite, J. Chem. Eng. Data 2010, 55, 783-788. K. Schwehr, P. Santschi, D. I. Kaplan, C. Yeager, R. Brinkmeyer, Organo-iodine formation in soils and aquifer sediments at ambient concentrations, Environ. Sci. Technol. 2009, 43, 7258. K. P. Grogan, T. A. DeVol, Online detection of radioactive iodine in aqueous systems through the use of scintillating anion exchange resin, Anal. Chem. 2011, 83, 2582-2588. SA El-Safty, T. Balaji, H. Matsunaga, T. Hanaoka, F. Mizukami, Optical sensors based on nanostructured cage materials for the detection of toxic metal ions, Angew. Chem. Int. Ed. 2006, 45, 7202- 7208.

As described above, iodine is an element useful for the human body, but radioactive iodine such as ¹²⁹ I and ¹³¹ I, which are radioactive isotopes, accumulates in the human body even in a trace amount on the order of ppb to ppm and induces carcinogenicity. Therefore, it is necessary to exclude not only water for daily life such as drinking water and washing water and the atmosphere but also all environments such as waste water and soil.

Therefore, it is necessary to know what concentration of iodine is contained in a solution such as domestic water or wastewater even in a small amount. However, there are few iodine collectors or concentration detection sensors that rapidly and accurately measure extremely small iodine concentrations on the order of ppb to ppm, and there is a problem that they cannot be used repeatedly even if they exist. In addition, since there are few collectors or sensors that selectively collect and detect iodine, a solution containing a plurality of elements and ions is affected by elements and ions other than iodine and cannot accurately measure iodine concentration. Furthermore, when a trace amount of iodine is present in a solution such as domestic water or wastewater, it is necessary to remove the iodine, but there are few methods for removing iodine to the ppb order level. In the case of an ion exchange resin or the like, ions of the ppb order level can be removed, but there is a problem that only iodine ions cannot be specified and removed. That is, there is almost no thing with good selectivity of selectively removing only iodine (ions).

In addition, after removing iodine with a recovery agent, there is a problem that it is difficult to effectively use the recovered iodine because the means for separating the iodine is difficult. There is also a problem that the cost for collecting and recycling iodine in solutions such as domestic water and wastewater is high. A simple, low-cost, high-selectivity, high-accuracy, high-speed method for detecting iodine concentration in the environment, removing iodine from the environment, and recovering and recycling useful iodine worldwide. Urgently required.

The present invention is a compound capable of selectively adsorbing iodine ions on mesoporous silica having a highly ordered structure (hereinafter referred to as iodine ion adsorbing compound (or meaning of collecting iodine (ion) (collecting agent)). An efficient method for recovering the adsorbed iodine by adsorbing the iodine ion to the adsorbed iodine ion-adsorbing compound, and an iodine ion used therefor The present invention provides a mesoporous silica carrying an adsorbing compound, and an iodine ion collector capable of detecting iodine ion concentration with high accuracy and using a mesoporous silica carrying an iodine ion adsorbing compound with high accuracy and in the ppb to ppm order. And provide a sensor.

After mixing the silica source and the surfactant, an acidic aqueous solution is added and calcined to produce mesoporous silica (HOM). This mesoporous silica carries an iodine ion adsorbing compound (iodine ions have not yet been adsorbed). An iodine ion-adsorbing compound is a compound that can selectively adsorb iodine ions. For example, a complex such as a chelate compound. (A compound that easily adsorbs a specific element ion is referred to as an element ion adsorbing compound in this application. Here, this means that a specific ion that the element ion adsorbing compound can selectively adsorb is recovered. A specific element is referred to as a target element.In the present invention, the target element is iodine.) As a compound that selectively and preferentially adsorbs iodine ions, for example, N, N`-bis (salicyridin) 2-mercapto Pyrimidine-4-ol-5,6-diamine {N, N` Bis (salicylidine) 2-mercaptopyriminidin-4-ol-5,6 diamine (BSCPD)}, N, N`-disalicylidene-4-nitro- Phenylenedene {N, N-disalicylidene-4-nitro-phenylenedene (DSNPD)}, trisodium 8-hydroxypyrene-1,3,6-3 sulfonate ester (pyranine) {Trisodium 8-hydroxypyrene-1,3,6 -trisulfonate (Pyranine)}, 1,5-diphenylthiocarbazone (dithio) Zon) {1,5-Diphenylthiocarbazone (Dithizone)}, 5- (4-Dimethylaminobenzylidene) rhodanine {5- (4-Dimethylaminobenzylidene) rhodanine (DMABR)}, Acid Red27, N, N, N ', N'-tetramethyl-4,4'-diaminothiobenzophenone (N, N, N', N'-Tetramethyl-4,4'-diaminothiobenzophenone) {Thiomichler's Ketone (TK)}. These iodine ion adsorbing compounds are supported on mesoporous silica. (For example, these iodine ion-adsorptive compounds are collectively referred to as MC, and mesoporous silica supporting MC is referred to as HOM-MC.) These may be supported alone on HOMS, or a plurality of combinations may be supported on HOMS. May be.

Contacting mesoporous silica carrying (or modifying) the iodine (ion) adsorptive compound in an ion-dissolved solution in which various ions including iodine (including not only element ions but also other cations and anions) are dissolved; Iodine ions (I ^{− and the} like), which are target element ions, are adsorbed on an iodine ion adsorbing compound supported on mesoporous silica. At this time, target element ions can be efficiently adsorbed by adjusting environmental factors such as pH value, solution concentration, and solution temperature of the ion-dissolved solution. For example, in the case of the above-mentioned HOM-DSNPD, the HOM-DSNPD can be obtained by bringing it into contact with an ion-dissolved solution containing iodine ions whose pH value is adjusted to 4 to 7, preferably 4.5 to 6.0. Iodine ions, which are ions, are preferentially, selectively and rapidly adsorbed. (The HOM-DSNPD that adsorbs iodine is referred to as HOM-DSNPD-I.) In the case of the above-mentioned HOM-TK, the pH value is 0.1 to 3.5, preferably 0.5 to 2.5. HOM-TK preferentially and selectively adsorbs iodine, which is a target element, by bringing it into contact with an ion-dissolved solution containing iodine ions adjusted to 1. (HOM-TK adsorbed with iodine is referred to as HOM-TK-I.)

Next, the mesoporous silica supporting the iodine ion adsorbing compound on which iodine ions are adsorbed is brought into contact with a solution capable of releasing iodine ions (iodine ion free solution), and the adsorbed iodine ions are dissolved in the iodine ion free solution. Let The solution is filtered to separate it into a solid and a liquid. Since the separated liquid dissolves only iodine ions, it is possible to recover the target element iodine. By controlling the concentration, pH, reaction temperature, etc. of the solution, the iodine recovery efficiency can be increased. The separated solid is mesoporous silica supporting an iodine ion adsorbing compound, and the iodine ion adsorbing compound supported on the mesoporous silica does not adsorb iodine. That is, the solid material returns to mesoporous silica supporting an iodine ion adsorbing compound (not adsorbing iodine ions).

Moreover, since the main body (mesoporous silica carrying an iodine ion-adsorbing compound) has not changed, it can be used again as an adsorbent (or collector (collecting agent) or extractant) for iodine ions that are target element ions. For example, in the case of the above-mentioned HOM-DSNPD-I, the adsorbed iodine can be liberated by, for example, being immersed in an HCl solution. HOM-DSNPD from which iodine has been separated can be used again as an iodine ion adsorbent. Moreover, in the case of the above-mentioned HOM-TK-I, the adsorbed iodine can be liberated, for example, by being immersed in a NaCl solution. HOM-TK from which iodine is separated can be used again as an iodine ion adsorbent.

In the present invention, the iodine ion-adsorbing compound is supported (modified) on the surface of the mesoporous silica having a large surface area or highly ordered structure and the inner wall of the pore (pore). Iodine ions adsorb easily and quickly. Therefore, not only the adsorption response speed is high, but also the iodine ion adsorption efficiency to the iodine ion adsorbing compound supported on mesoporous silica is much higher than the iodine ion adsorption efficiency to a single iodine ion adsorbing compound. At the same time, the amount of iodine (ion) adsorption increases.

In addition, since iodine ions adsorbed on the iodine (ion) adsorbing compound are arranged in order and densely adsorbed, the adsorbed iodine ions can be easily released (separated) quickly. Therefore, the release efficiency of iodine ions is very high. The iodine ion-adsorptive compound can selectively adsorb iodine ions in a large amount and rapidly by adjusting the pH value of the iodine ion solution. Therefore, only iodine (ion) can be efficiently recovered. Moreover, since a very small amount of iodine ions in the order of ppb to ppm can be removed by adsorption, the concentration of iodine ions contained in a solution such as domestic water and waste water, soil and other ion-dissolved solutions can be reduced to a very small level. Since trace amounts of radioactive iodine in the environment, which has become a problem in recent years, can be efficiently and rapidly removed, the material is useful for maintaining the health of the human body.

Furthermore, the mesoporous silica carrying the iodine ion-adsorbing compound has a strong skeleton, and the skeleton of the mesoporous silica is hardly changed by the loading of the iodine ion-adsorbing compound or the adsorption of iodine ions. Since the adsorbed iodine ions can be almost completely released, it returns to the original state (mesoporous silica supporting an iodine ion-adsorbing compound not adsorbing iodine ions). Can be used repeatedly. That is, it can be recycled or reused many times.

Therefore, the total (total) iodine collection / recovery cost can be reduced. Further, the mesoporous silica supporting the iodine ion adsorbing compound to which the iodine ion of the present invention is adsorbed is very low on the order of ppb to ppm using a colorimetric method or UV-VIS-NIR spectroscopy. Since the iodine ion concentration of a density | concentration can also be detected, it can be used also as an iodine ion collector and a concentration sensor.

FIG. 1 is a diagram showing an iodine recovery system of the present invention. FIG. 2 is a diagram showing a method for synthesizing HOM silica monolith. FIG. 3 is a diagram showing the characteristics of HOM silica monolith. FIG. 4 is a diagram showing a synthesis method of BSCPD, a reaction formula with iodine when iodine is adsorbed to BSCPD dissolved in an aqueous solution, and a visualization analysis in which iodine is adsorbed on BSCPD. FIG. 5 is a diagram showing a synthesis method of DSNPD and a reaction formula with iodine when iodine is adsorbed to DSNPD. FIG. 6 is a diagram showing a chemical formula of pyranine, a reaction formula when iodine is adsorbed to pyranine, and a color tone change due to iodine adsorption in an aqueous solution. FIG. 7 is a diagram showing the chemical formula of dithizone, the reaction formula when iodine is adsorbed to dithizone, and the change in color tone due to iodine adsorption in an aqueous solution. FIG. 8 is a diagram showing a chemical formula of the receptor DMABR, a reaction formula when iodine is adsorbed to the receptor DMABR, and a color change due to iodine adsorption in an aqueous solution. FIG. 9 is a diagram showing a chemical formula of the receptor Acid Red 27, a reaction formula when iodine is adsorbed on the receptor Acid Red 27, and a change in color tone due to iodine adsorption in an aqueous solution. FIG. 10 is a diagram showing the chemical formula of the receptor TK, the reaction formula when iodine is adsorbed to the receptor TK, and the change in solid color due to the adsorption of iodine to TK in an aqueous solution. FIG. 11 is a diagram showing a method for manufacturing a HOM-TK collector. FIG. 12 is a graph showing the relationship between the ultraviolet visible spectrum signal intensity of HOM-TK-I (measured at room temperature) and the pH value of the solution. FIG. 13 is a graph showing the relationship between the ultraviolet visible spectrum signal intensity of HOM-DSNPD-I (measured at room temperature) and the pH value of the solution. FIG. 14 is a diagram showing an iodine ion extraction method using a HOM1-TK probe supported on HOM as an iodine remover. FIG. 15 is a diagram showing an absorption spectrum of UV-visible spectroscopy at room temperature of HOM-TK-I using the iodine ion concentration in a solution with pH = 2.0 as a parameter. FIG. 16 is a diagram showing the relationship between the iodine ion concentration in the solution at pH = 2.0 and the absorbance (λ = 639 nm) of the UV-visible spectrum of HOM-TK-I. FIG. 17 is a diagram showing an absorption spectrum and colorimetric analysis of HOM-DSNPD-I at room temperature using ultraviolet-visible spectroscopy using iodine ion concentration as a parameter. FIG. 18 is a diagram showing the relationship between the iodine ion concentration in the solution with pH = 5.2 and the absorbance (λ = 615 nm) of the UV-visible spectrum of HOM-DSNPD-I. FIG. 19 is a diagram showing UV-VIS-NIR analysis data and color tone data of a solid obtained after immersing HOM-TK in a solution containing various metal ions including iodine ions. FIG. 20 is a diagram showing UV-VIS-NIR analysis data and color tone data of a solid obtained after immersing HOM-TK in a solution containing iodine ion, various anions or surfactants individually. FIG. 21 is a diagram showing a UV-visible spectrum by a HOM-DSNPD collector and a color tone of a HOM-DSNPD collector in the presence of a cation and an anion. FIG. 22 is a diagram showing a change in color tone and an ultraviolet-visible spectrum change in elution / back-extraction of iodine (HOM-DSNPD-I) adsorbed on a HOM-DSNPD collector by a 2.0 M HCl solution. FIG. 23 is a diagram showing a change in color tone of elution / back-extraction of iodine (HOM-TK-I) adsorbed on a HOM-TK collector using a 0.025 M NaCl solution. FIG. 24 shows the measurement data of the concentration of each ion before and after immersing HOM-TK in an iodine ion dissolving solution containing a plurality of ions, and the solution in the solution after elution of iodine using NaOH solution from HOM-TK-I. It is a table | surface which shows the measurement data of the density | concentration of each ion. FIG. 25 shows measured data of the concentration of each ion before and after immersing HOM-DSNPD in an iodine ion dissolving solution containing a plurality of ions, and in the solution after elution of iodine from HOM-DSNPD-I using an HCl solution. It is a table | surface which shows the measurement data of the density | concentration of each ion. FIG. 26 is a table showing the applicable range of the HOM-DSNPD collector and the HOM-TK collector of the present invention. FIG. 27 is a view showing a system for recovering iodine (I) from an iodine ion-dissolved solution containing radioactive iodine and the like using mesoporous silica (HOMS) supporting DSNPD or TK of the present invention.

The present invention provides iodine ion detection technology and iodine recovery technology using various compounds such as chelates having high selectivity and optical detection function. A feature of this technology is that it utilizes nano-sized surface states arranged at the atomic level of mesoporous materials composed of different atoms. The present invention is very excellent as a method for extracting iodine from wastes containing various active ions (cations and anions), surfactants, etc., water for daily use and the environment. In particular, it is extremely excellent as a method for removing radioactive iodine, which has been a problem in recent years, from the environment.

The inner surface of mesoporous silica arranged at the nano level makes iodine collectors and sensors by controlling the environmental conditions such as pH and varying the fixation / dissociation state. Iodine ions can be reliably adsorbed by bonding between adjacent atoms and surface atoms having different electron orbital structures and compounds such as chelates. Furthermore, the nano-ordered ordered arrangement on the inner wall surface of the mesoporous material increases the charge transfer, so that optical changes that can be observed with the naked eye even with a very small amount of iodine adsorption at the ppb level (fast response). Occur.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a diagram showing an iodine recovery system of the present invention. First, highly ordered mesoporous silica (HOM silica (HOMS): High Ordered Mesoporous Silica; normally, HOM does not include silica, but in this specification etc. In this case, silica is also included unless otherwise specified.) Here, mesoporous silica is a kind of porous silica, which has pores (mesopores) having a substantially uniform and regular diameter called a mesopore region having a size of 2 nm to 50 nm. It is a group of porous materials that are known to have various properties depending on the type of network (spatial symmetry) created by the pores, the manufacturing method, and the like. However, in this patent application, porous silica having micropores (pores of 2 nm or less) smaller than mesopores or macropores (pores of 50 nm or more) larger than mesopores is also referred to as mesoporous silica.

The form of HOM used in the present invention includes a thin film form and a monolith form. The monolith form usually refers to various forms other than a thin film, such as fine particles, particles, block-like forms and the like. Highly ordered means a state in which cubic and hexagonal mesoporous structures are regularly arranged on the surface and inner wall surface in three dimensions, for example, cubic Ia3d, Pm3n, Fm3m and hexagonal P6m structures. If these structures exist in a wide range, a large amount of iodine ion-adsorbing compounds can be supported, and the total iodine ion adsorption amount can be increased. Also, the larger the BET specific surface area of HOM, the better, but it is usually 400 m ² / g or more, preferably 500 m ² / g or more.

HOM silica can be synthesized by various methods. For example, in the sol-gel method using a surfactant as a template, when a surfactant is dissolved in an aqueous solution at a concentration equal to or higher than the critical micelle concentration, micelle particles having a certain size and structure are obtained depending on the type of the surfactant. It is formed. When left standing for a while, the micelle particles take a packed structure and become a colloidal crystal. When an organic silicon compound or the like serving as a silica source is added to the solution and a trace amount of acid or base is added as a catalyst, the sol-gel reaction proceeds in the gaps between the colloidal particles to form a silica gel skeleton. Finally, when fired at a high temperature, the surfactant used as a template is decomposed and removed to obtain pure highly ordered mesoporous silica (HOM silica). Further, for example, preferably, an organosilicon compound and a surfactant are mixed to form a lyotropic liquid crystal phase, and further, an aqueous acid solution is added to cause a hydrolysis reaction of the organosilicon compound in a short time, resulting in mesoporous After obtaining a composite product of silica and surfactant, a method is used in which the surfactant is removed to obtain HOM silica.

As the organic silicon compound, for example, silicon alkoxide such as tetramethylorthosilicate {also referred to as C4H12O4Si, TMOS (tetramethoxysilane)} or tetraethylorthosilicate {also referred to as C8H20O4Si, TEOS (tetraethoxysilane)} is used. (Because it is easier to remove methanol from ethanol by heating, vacuuming, etc. from the product, TMOS is preferable to TEOS rather than TEOS.) For the formation of HOM, in addition to organic silicon compounds, An inorganic silicon compound can also be used. For example, kanemite (NaHSi2O5 · 3H2O), sodium disilicate crystal (Na2Si2O5), macatite (NaHSi4O9 · 5H2O), eyeraite (NaHSi8O17 · XH2O), magadiite (Na2HSi14O29 · XH2O), KenyaO2 glass (Na2H2Si2O) Soda), glass, and amorphous sodium silicate can also be used. You may use these in mixture of 2 or more types.

Various surfactants can be used as templates. For example, a cationic, anionic, amphoteric or nonionic surfactant can be used. Examples of the cationic surfactant used as a template include primary amine salts, secondary amine salts, tertiary amine salts, and quaternary ammonium salts. Examples of the anionic surfactant used as a template include carboxylate, sulfate ester salt, sulfonate salt, phosphate ester salt, soap, higher alcohol sulfate ester salt, higher alkyl ether sulfate ester. Salts, sulfated oils, sulfated fatty acid esters, sulfated olefins, alkyl benzene sulfonates, alkyl naphthalene sulfonates, paraffin sulfonates and higher alcohol phosphate ester salts.

Examples of the amphoteric surfactant used as a template include sodium laurylaminopropionate, stearyldimethylbetaine, and lauryldihydroxyethylbetaine. Examples of the nonionic surfactant used as a template include polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether, polyoxyethylene alkylphenyl ether, polyoxyethylene sterol ether, polyoxyethylene lanolin acid derivative, polyoxyethylene Examples include ether type compounds such as polyoxypropylene alkyl ether, polypropylene glycol, and polyethylene glycol, and nitrogen-containing types such as polyoxyethylene alkylamine. You may use these in mixture of 2 or more types.

The HOM structure (pore size, shape, crystal structure, etc.) can be controlled by changing the type of surfactant, so the crystal structure is highly ordered, the BET specific surface area is large, and the pore density is large. A surfactant capable of forming HOM is preferred. For example, polyoxyethylene (10) cetyl ether (Brij56: C16H33 (OCH2CH2) 10OH, C16EO10), triblock copolymer surfactant (eg, pluronic® P123: EO20PO70EO20, Pluronic® F108: EO141PO44O141) ) Can be used. Mixing with a weight ratio of Brij56: TMOS = 0.5 gives a cubic structure Pm3n, mixing with a weight ratio of P123: TMOS = 0.7-0.8 gives a cubic structure Ia3d, F108: weight ratio of TMOS = 0.7 To obtain a cubic structure Im3m cage silica structure.

FIG. 2 is a diagram showing a method for synthesizing HOM1 (cubic Im3m) silica monolith. The HOM silica monolith was synthesized by employing the instantaneous direct template method with the copolymer surfactant F108 (EO ₁₄₁ PO ₄₄ EO ₁₄₁ ). Usually, mesoporous silica monoliths with cubic Im3m (HOM1) cage mesopores add dodecane to the F108 / tetramethyl orthosilicate (TMOS) mixed phase in a ratio of dodecane: F108: TMOS = 1: 2.8: 4. Was made using a microemulsion phase formed by This HOMS is a white powdery solid. In the present application, the HOMs produced according to FIG. 2 may be referred to as HOM1 and 1.

Next, in the second stage, the iodine ion-adsorbing compound is supported on the HOM. At this stage, iodine ions (and other ions) are not adsorbed on the iodine ion adsorbing compound. (The term “iodine ion adsorbing compound” is used as a term indicating that no iodine ions are adsorbed. Examples of the iodine ion adsorbing compound used in the present invention include ion complexes, inorganic compounds and organic compounds. Cellulose, protein, etc. The metal ion complex includes inorganic and organic metal complexes, metal carbonyl compounds, metal clusters and organometallic compounds, and also includes chelate compounds. A compound capable of adsorbing ions on the HOM, capable of releasing ions other than iodine as a target element by chemical treatment, and then releasing iodine as a target element by other chemical treatment. Iodine ion-adsorptive compounds are chemically bonded to HOM silica, for example, via OH groups. There.

The iodine ion-adsorbing compound is preferably a compound that selectively adsorbs iodine ions, which are target element ions to be collected, in a large amount. For example, chelate compounds and other compounds that selectively bind to iodine ions can be used. By adjusting the pH value, temperature, concentration, etc. of iodine ion-dissolved solution in which various ions (cations and anions) containing iodine and surfactants are dissolved, iodine (ion) which is the target element for iodine ion-adsorbing compounds Can be selectively and preferentially adsorbed in large quantities. In addition, since a compound such as a chelate compound can selectively adsorb a very small amount (for example, ppb order) of iodine, it is efficient even if the amount of iodine ion contained in the iodine ion solution is small. To selectively adsorb iodine ions.

For example, the compound of N, N`-disalicylidene-4-nitro-phenylenedene {N, N-disalicylidene-4-nitro-phenylenedene (abbreviated as DSNPD)} is also referred to as the receptor DSNPD) selectively selects iodine ions. It was found that it preferentially adsorbs. (Receptor is originally a biological term “receptor”, but in this application, the term “receptor” may be used to mean an (iodine) ion-adsorbing compound that adsorbs a specific element (iodine) ion. is there.)

As will be described later, when this receptor DSNPD is immersed in a solution containing iodine ions (iodine ion-dissolved solution) in which the solution is adjusted to a specific pH value, when the HOM silica carrying the receptor DSNPD is immersed in the receptor DSNPD, It selectively adsorbs iodine ions in a larger amount than in solution. As the adsorption amount of iodine ions increases, the color of the HOM silica supporting the receptor DSNPD changes from light yellow to yellow (iodine ion concentration 100ppb), and further pale green yellow (iodine ion concentration 4ppm), yellow green (iodine ion) The concentration changes to 12ppm). Since the color tone and the adsorbed iodine ion concentration are correlated, the iodine ion concentration can be known from the color tone. That is, colorimetric analysis is possible. In particular, even a very small amount of iodine at the ppb level can be adsorbed, resulting in a change in color tone, so that an accurate concentration can be detected. By selectively immersing HOM silica (HOM1-DSNPD) carrying these receptors DSNPD in a solution containing iodine ions and other various ions (cations and anions) and surfactants, only iodine ions This means that the other various ions are hardly adsorbed. That is, HOM silica (HOM1-DSNPD) carrying the receptor DSNPD is extremely excellent in iodine ion adsorption selectivity.

The iodine ion concentration can also be measured from the light absorption spectrum after iodine ion adsorption. That is, HOM silica carrying the receptor DSNPD is also an iodine ion concentration detection sensor. This mesoporous silica (HOM1-DSNPD) carrying the receptor DSNPD shows an absorption peak based on iodine adsorption in visible light having a wavelength of 600 nm to 650 nm in the ultraviolet-visible spectroscopy when iodine ions are adsorbed. Since there is a correlation between the iodine ion concentration and the calibration curve in advance, this HOM-DSNPD can be obtained from the absorbance data at the wavelength in the UV-visible spectroscopy of HOM1-DSNPD that has adsorbed iodine ions. The iodine ion concentration of -I can be known. Moreover, this HOMS-DSNPD-I selectively adsorbs iodine ions in the solution and hardly adsorbs other contained ions, so that it becomes a highly sensitive iodine ion collector and concentration sensor. In particular, even a very small amount of iodine at the ppb level can be adsorbed, resulting in a change in spectrum, so that an accurate concentration can be detected.

Examples of other iodine ion adsorbing compounds include N, N`-bis (salicylidine) 2-mercaptopyrimidine-4-ol-5,6-diamine {N, N` Bis (salicylidine) 2-mercaptopyriminidin-4 -ol- 5,6 diamine (BSCPD)}, trisodium 8-hydroxypyrene-1,3,6-3 sulfonate ester (pyranine) {Trisodium 8-hydroxypyrene-1,3,6-trisulfonate (Pyranine)}, 1,5-diphenylthiocarbazone (dithizone) {1,5-Diphenylthiocarbazone (Dithizone)}, 5- (4-dimethylaminobenzylidene) rhodanine {5- (4-Dimethylaminobenzylidene) rhodanine (DMABR)}, Acid Red 27 ( Acid Red 27), or N, N, N ′, N′-tetramethyl-4,4′-diaminothiobenzophenone {Thiomichler's Ketone (TK)}. One or more of these iodine ion-adsorbing compounds can be supported on HOMS to produce a HOMS-receptor having the desired properties. These compounds adsorb (collect) iodine (ions) by incorporating iodine (ions) within and / or between the cyclic molecular structures. Although the iodine ion is an anion that is not a metal ion, these compounds behave like a chelate with respect to iodine (ion) and can be considered as a chelate compound in a broad sense. These iodine ion adsorbing compounds hardly adsorb fluorine and chlorine, which are the same halogen group as iodine, and hardly adsorb other anions and cations (including metal ions such as alkali metals). It is a compound with high selectivity. It is considered that iodine (ions) is adsorbed (bonded) to these compounds through covalent bonding.

There are various methods as a method (also referred to as a composite method) for supporting (modifying) such an iodine ion-adsorbing compound on the HOM. For example, when the iodine ion-adsorbing compound to be held in the HOM is neutral, a reagent impregnation method (REACTIVE & FUNCTION POLYMERS, 49, 189 (2001), etc.) is used, and when it is anionic The cation exchange method is used, and if it is cationic, the anion exchange method is used. These compounding methods belong to known general technical fields, not special conditions and operations. Therefore, for the details of these general technical fields, it is possible to refer to reviews, literatures and the like regarding the solid adsorption field.

For example, mesoporous silica is surface-treated with a cationic organic reagent (for example, a cationic silylating agent) to impart a cationic functional group to the mesoporous silica, and then the cationic mesoporous silica and an anion are added. A method in which an aqueous solution or alcohol solution of an ionic iodine ion adsorbing compound is contacted to adsorb the iodine ion adsorbing compound in mesoporous silica, an organic solvent solution in which mesoporous silica and an iodine ion adsorbing compound are in contact is contacted Is removed by filtration or distillation, and the iodine ion-adsorbing compound is physically adsorbed and supported in the mesoporous silica, the mesoporous silica is surface-treated using a silylating agent having a thiol group, By oxidizing the thiol group on the generated surface, its meso A method of attaching an anionic functional group to a porous silica, bringing the anionic mesoporous silica and an aqueous solution of a cationic metal adsorbing compound into contact with each other, and adsorbing the iodine ion adsorbing compound in the mesoporous silica; A method of fixing an iodine ion-adsorptive compound in the pores and on the surface by treating the compound with an organic solvent solution of a cationic organic reagent after filling the active compound in the pores and on the surface, iodine ion-adsorptive compound And the cationic organic reagent are mixed in advance, the organic solvent solution of the obtained reagent complex is brought into contact with the silica, and only the organic solvent is removed by filtration or distillation, whereby the iodine ion-adsorbing compound is converted into the silica. The method of carrying in is used.

For example, to support the receptor DSNPD on the HOM, the receptor DSNPD is dissolved in N, N-dimethylformamide {N, N-Dimethylformamide (DMF)}, and this solution is brought into contact with HOMS, so that the receptor DSNPD is transferred to the HOMS. Impregnate. In this way, HOM silica (HOMS-DSNPD) in which receptor DSNPD is regularly and densely supported is completed. In addition, HOM silica carrying the receptor DSNPD can be efficiently produced in a high-purity solid state (powder) by evaporating liquids such as DMF and moisture (heating, vacuuming, etc.) and further drying.
In addition, the larger the porous (pore) density of the HOM silica, the higher the order of the crystal structure and the higher the BET specific surface area, the more receptors are regularly supported on the surface of the HOM silica and the inner walls of the pores. For example, the receptor DSNPD {(iodine ion) adsorptive compound} is preferably adsorbed on HOM silica in which structures such as cubic structures Im3m, Pm3n, Fm3m, Ia3d, and hexagonal structure P6m are formed in a wide range.

Naturally, the iodine ion-adsorbing compound alone can selectively adsorb iodine ions as the target element. However, since the iodine ion-adsorbing compound aggregates and the like, a functional group capable of adsorbing iodine ions cannot be used effectively. That is, even if iodine ions as the target element are adsorbed to the functional groups present on the surface of the aggregated (eg, particulate) iodine ion-adsorbing compound substance, iodine inside the iodine ion-adsorbing compound is diffused or permeated. Since the ion concentration decreases exponentially with respect to the distance (square), it is difficult for iodine ions to be adsorbed to all the functional groups of the iodine ion-adsorbing compound inside the particulate matter. In addition, even if iodine ions are adsorbed to the functional group of the iodine ion-adsorbing compound inside the particulate matter, there is a problem that it is difficult to take out (free or back-extract) the adsorbed iodine ions. . It is possible to diffuse iodine ions inside the particulate matter and take it out for a long time, but moving iodine ions inside the particulate matter over a long period of time results in poor productivity and Cannot be used.

On the other hand, mesoporous silica has a very large pore surface area and a highly ordered orientation structure. So, mesoporous silica with iodine ion-adsorbing compounds on the surface and inner wall of the pore is adsorbed with iodine ions. Since the active compound is arranged in an orderly manner and bonded, the iodine ion adsorption rate of the iodine ion adsorbing compound becomes very high. That is, each molecule of iodine ion adsorbing compound can be used for iodine ion adsorption. Iodine ion-dissolved solution and free (back-extraction) solution easily and quickly penetrate the surface and pores of mesoporous silica, so easily with iodine ion-adsorbing compound (reactive group) supported by HOMS, In addition, contact quickly. This means that the iodine ion-adsorbing compound supported on HOMS adsorbs iodine ions quickly when it comes into contact with the iodine ion solution. It also means that when adsorbed iodine ions are released, the adsorbed iodine ions are released quickly if they come into contact with the free solution. Therefore, adsorption (collection) and release (separation) of iodine ions are very As a result, productivity is dramatically improved.

For example, in the case of a chelate resin alone, the surface atoms do not all have a chelate (functional group) effectively on the surface of the chelate resin, and the chelate reaction ends are discrete in atoms. It has become. Even when chelating resin alone adsorbs iodine ions, it cannot be controlled which part of chelating resin is attached. In addition, iodine ions are expected to be adsorbed (also referred to as extraction) to chelate functional groups in contact with iodine ion-dissolved solutions, but iodine ions are almost adsorbed inside chelate resins that are difficult to penetrate iodine ion-dissolved solutions. It is thought that it is not done. That is, iodine ion adsorption efficiency is very poor. Further, when iodine ions adsorbed on the chelate resin are released (also referred to as back extraction), it is difficult to take out the iodine ions adsorbed inside the chelate resin.

Even when this chelate resin is repeatedly used, the efficiency of extraction and back-extraction of iodine ions becomes worse due to the influence of the residue in the chelate resin, and the performance of the chelate resin is greatly deteriorated by repeated use. On the other hand, those in which a chelate resin is supported on a HOM can form a chelate functional group on the surface of the HOM in a wide range using an atomic arrangement aligned with the large specific surface area of the HOM. In other words, the reaction end of the chelate is almost the same in HOM. In addition, the reaction end of the chelate is so large on the HOM surface and the inner wall of the pore that the conventional chelate resin alone cannot be realized. Since the chelate functional group selectively captures iodine ions or complex ions containing iodine ions, the adsorption efficiency of iodine ions becomes very high. In addition, the trapped iodine ions or complex ions containing iodine ions can be easily extracted by back extraction. Furthermore, when the chelate resin is used alone, the physical and / or chemical strength of the resin itself is insufficient, so the deterioration due to repeated use of the chelate resin is large. Since the physical and / or chemical strength of the HOM as the skeleton is sufficient, deterioration due to repeated use is small, and it can be used repeatedly, that is, reused any number of times.

In the third stage, an aqueous solution in which various ions (cations and anions) containing iodine ions, a surfactant, and the like are dissolved (this is called an iodine ion dissolving solution) is prepared. This iodine ion-dissolved solution is, for example, a solution in which radioactive iodine-containing nuclear fluid cooling liquid or waste liquid is discharged, or radioactive iodine scattered from the nuclear facility is dissolved in domestic water or domestic wastewater. In such a solution, various ions such as cations such as various metal ions, various anions and surfactants are dissolved in addition to iodine. If this solution contains solids, it is desirable to remove it in advance. This is because the HOM-MC probe immersed in this solution is a solid, and this is mixed with the solid content.

Therefore, a solution obtained by removing solids from this solution is an iodine ion dissolving solution. Iodine ion-dissolved solution is contacted with iodine ion-dissolved solution and HOM-MC by immersing HOM (hereinafter also referred to as HOM-MC) carrying an iodine ion-adsorbing compound (hereinafter referred to as MC) at a high density. . By this contact, iodine ions are adsorbed on the HOM-MC. (This is HOM-MC-I-M (I: target element iodine (I), M: adsorbed ions other than iodine). Iodine ion-adsorbing compounds have certain conditions (pH value, temperature ), The target element iodine ions are selectively and preferentially adsorbed, so if the iodine ion adsorbing compound is immersed in an iodine ion dissolving solution under the conditions, only the target element iodine is Can be obtained.

For example, HOM-MC can be brought into contact (including immersion) with an iodine ion dissolving solution adjusted to a pH value that best adsorbs iodine ions, and iodine ions can be selectively adsorbed in large quantities on HOM-MC. However, since there is a possibility that a small amount of other ions M may be adsorbed due to slight fluctuations in conditions, etc., by reducing the number of ions other than iodine as the target element in the iodine ion solution beforehand, HOM-MC-I-M with a very small amount of adsorption of ions M can be obtained. For example, there is a method in which ions other than iodine ions are deposited and removed by adjusting pH or chemical treatment in an iodine ion dissolving solution. Alternatively, there is also a method in which ions other than iodine ions are precipitated and removed using a compound that does not adsorb iodine ions (which may be prepared as appropriate HOM-MC).

In the case of the above receptor DSNPD, the iodine ion dissolving solution is adjusted to pH = 4.0 to 7.0, preferably pH = 4.5 to 6.0, so that iodine ions can be efficiently adsorbed to HOM-MC (HOM-DSNPD). Can do. In the case of the above receptor TK, iodine ions are efficiently adsorbed on HOM-MC (HOM-TK) by adjusting the iodine ion solution to pH = 0.1 to 3.5, preferably pH = 0.5 to 2.5. Can be made. It should be noted that HOM silica adsorbed with iodine ions can be efficiently collected in a high-purity solid state (powder) by evaporating (heating, vacuuming, etc.) liquid components such as ethanol and moisture and further drying.

In the fourth stage, HOM-MC-I-M adsorbing ions containing iodine ions as target elements is immersed in a solution capable of releasing ions other than iodine ions as target elements, and iodine as target elements. Ions other than the ions are removed, and the HOM-MC-I adsorbs only the target element iodine. Alternatively, in some cases, HOM-MC-I can be obtained by removing ions other than iodine as the target element by adjusting conditions such as pH value, temperature, and solution concentration. If there is very little adsorption of ions other than iodine as the target element (in this case, it is HOM-MC-I from the beginning), or if there is a method that can liberate only the target element iodine, the fourth The stage can be omitted. For example, in the case of HOM-DSNPD carrying the above receptor DSNPD or HOM-TK carrying the receptor TK, M is hardly adsorbed, that is, it is in a state of HOM-DSNPD, TK-I. The fourth stage can be omitted.

In the fifth stage, HOM-MC-I that has adsorbed almost only the target element iodine is immersed in a solution capable of dissolving the target element iodine to dissolve iodine ions as the target element. In some cases, only iodine ions, which are target elements, can be liberated by adjusting conditions such as (elution treatment), pH value, temperature, and solution concentration. Or the iodine ion which is a target element can be melt | dissolved by immersing in the solution which can isolate | separate only the iodine ion which is a target element. In such a case, it is not always necessary to use HOM-MC-I that adsorbs only the target element iodine ion. Since HOM-MC from which iodine ions as target elements are liberated from this solution is a solid, it is removed by filtration. The HOM-MC removed as a solid can be used again. For example, in the case of HOM-DSNPD-I, I is almost completely eluted by being immersed in an HCl solution. In the case of HOM-TK-I, I is almost completely eluted by immersion in NaCl solution.

Further, iodine as the target element can be recovered by separating iodine as the target element from the eluent in which iodine is dissolved by the elution process by various methods (for example, ion exchange resin method and blowout method). That is, iodine as a target element could be recovered from environmental water in which iodine was dissolved. For example, iodine ions can be liberated by immersing HOM-DSNPD-I in an HCl solution. As a result, the solid HOM-DSNPD can be reused by filtration and can be used again in the third stage. Since iodine ions are dissolved in the elution (elution) solution, for example, iodine can be vaporized and recovered as simple iodine (I ₂ ) by the blowout method. In addition, this process liberates I from HOM-MC-I when it is considered that the target element iodine is adsorbed to HOM-MC to form HOM-MC-I. Since it is HOM-MC, it can also be called back extraction (process).

From the iodine ion-dissolved solution in which iodine containing radioactive iodine, which is the target element obtained from the waste liquid from nuclear facilities, domestic water and environmental water, is obtained by going through the first to fifth steps described above. The target element iodine can be recovered using highly ordered HOM silica (HOMS) carrying an iodine ion adsorbing compound.

<Synthesis of HOM5 (cubic Ia3d) silica monolith>
FIG. 2 is a diagram showing a method for synthesizing HOM1 (cubic Im3m) silica monolith. The HOM silica monolith was synthesized by employing the instantaneous direct template method with the copolymer surfactant F108 (EO ₁₄₁ PO ₄₄ EO ₁₄₁ ). Mesoporous silica monolith with cubic Im3m (HOM-1) cage mesopores adds dodecane to the F108 / tetramethyl orthosilicate (TMOS) mixed phase in the ratio of dodecane: F108: TMOS = 1: 2.8: 4 Was made using a microemulsion phase formed by

That is, 8.0 g of TMOS and 4.0 g of surfactant F108 are placed in a flask container, and 2.0 g of dodecane is added therein, and the surfactant is completely dissolved. It was held in warm water at about 60 ° C. When the composition phase of this homogeneous solution is evaporated in a rotary evaporator by adding 4 g of acidic aqueous solution (H ₂ O-HCl) having a pH of 1.3, exothermic hydrolysis and concentration of TMOS occurs rapidly.

Since this exothermic hydrolysis / concentration reaction is continued in the exhaust by the rotary evaporator, the viscosity of the liquid material is increased, and the formed colored gel substance is formed in the reaction vessel. A translucent glassy monolith was collected after 10 minutes evacuation on a rotary evaporator and dried in an oven at 40 ° C. for 16 hours. The surfactant and moisture were then removed by calcination at 450 ° C. (1 hour in nitrogen and 6 hours in oxygen) to produce a white powdery HOM1 (cubic Im3m) silica monolith.

<Characteristics and crystal structure of cubic Im3mHOM1>
FIG. 3 shows an X-ray diffraction (XRD) pattern (A) of a calcined silica caged cubic Im3m monolith (HOM1) synthesized using a lyotropic mesophase of F108 template (template) with an F108 / TMOS ratio of 50 wt%. Nitrogen adsorption / desorption isotherm (B) and transmission electron microscope (TEM) diffraction patterns (C, D, E) are shown. TEM patterns were recorded along {FIG. 3 (C)} [100], {FIG. 3 (D)} [110], and {FIG. 3 (E)} [111] directions. In the nitrogen adsorption / desorption isotherm {FIG. 3 (B)}, D is the pore size (nm) of HOM1, Vp is the pore volume (cm ³ / g) of HOM1, and SBET is the BET specific surface area of HOM1 (m ² / g).

The preferred centered cubic (bcc) Im3m caged monolith (HOM1) shown in FIG. 3 was synthesized using the copolymer F108 (EO ₁₄₁ PO ₄₄ EO ₁₄₁ ) with a F108 / TMOS ratio of 50 wt%. The X-ray diffraction (XRD) pattern of this HOM1 shown in FIG. 3A shows a clear diffraction peak in the range of 0.5 <2θ <2.4 °, and has a large lattice constant up to 15.7 nm. The ratio of ordered cubic Im3m is high. The transmission electron microscope (TEM) diffraction patterns shown in FIGS. 3 (C) to (E) clearly show white dot arrays having a large shape phase. This is the sequence identified as a regular cage-like pore array. Further evidence of a cage-shaped mesostructured monolith with controlled shape and size was obtained from the nitrogen adsorption / desorption isotherm shown in FIG. 3 (B). That is, from the steepness clearly defined as a large hysteresis loop of the H2 type (IUPAC classification), it is shown that HOM1 has a crystal structure of a large and uniform cage structure. Further, it can be seen that the pore size of HOM1 is as very small as 7 nm, and the BET specific surface area is as large as 760 m ² / g. Thus, HOM1 produced by the above-described method is a highly ordered mesoporous silica having a very small pore size and a very large specific surface area.

<Synthesis of receptor used for recovery of radioactive iodine (1)>
<N, N`-bis (salicylidine) 2-mercaptopyrimidine-4-ol-5,6-diamine {N, N` Bis (salicylidine) 2-mercaptopyriminidin-4-ol-5,6 diamine (BSCPD) } Production>
FIG. 4 is a diagram showing a synthesis method of BSCPD, a reaction with iodine when iodine is adsorbed to BSCPD dissolved in an aqueous solution, and a visualization analysis (color change) in which iodine is adsorbed to BSCPD. 2 moles of salicylaldehyde, 1 mole of 5,6-diamino-2-mercaptopyrimidin-4-ol- and 2-3 drops of concentrated sulfuric acid (or , P-toluenesulfonic acid in small amounts) produced BSCPD. The resulting mixture was heated at reflux for 6 hours, then left to cool at room temperature. The solid formed during cooling was collected by suction filtration. The isolated yellow product was recrystallized from a dichloromethane / methanol (1/1) system. This solid was BSCPD, which was used to investigate iodine removal in the liquid. As shown in FIG. 4, when iodine is adsorbed to the BSCPD aqueous solution in the aqueous solution, the transparent yellow aqueous solution changes to a transparent brown aqueous solution. Iodine is not a metal ion (cation) but an anion, but iodine (ion) is incorporated into the cyclic molecular structure (broadly defined complex) of BSCPD, just as BSCPD is a chelate complex.

<Synthesis of receptor used for recovery of radioactive iodine (2)>
<Preparation of N, N`-disalicylidene-4-nitro-phenylenedene {N, N-disalicylidene-4-nitro-phenylenedene (DSNPD)}>
FIG. 5 is a diagram showing a method for synthesizing DSNPD and a reaction with iodine using DSNPD. By adding 2-3 drops of concentrated sulfuric acid to 2-hydroxybenzaldehyde and 4-nitro-O-phenylenediamine in a benzene solvent and reacting them, DSNPD was generated. The resulting mixture was heated at reflux for 6 hours, then left to cool at room temperature. The solid formed during cooling was collected by suction filtration. This solid is DSNPD. This material was then recrystallized using dichloromethane / methanol (1/1). After the preparation of DSNPD, when iodine is adsorbed to DSNPD in an aqueous solution, iodine (I) is taken into the cyclic molecular structure of DSNPD as shown in the chemical formula of FIG.

<Synthesis of receptor used for recovery of radioactive iodine (3)>
<Preparation of trisodium 8-hydroxypyrene-1,3,6-3 sulfonate (pyranine) {Trisodium 8-hydroxypyrene-1,3,6-trisulfonate (Pyranine)}
FIG. 6 is a diagram showing a chemical formula of pyranine, a reaction formula when iodine is adsorbed to pyranine, and a visualization analysis (color change) by iodine adsorption in an aqueous solution. The clear colorless pyranine aqueous solution turned into a clear light yellow solution by adsorption of iodine (2000 ppb). As shown in the chemical formula of FIG. 6, iodine (I) is incorporated between the cyclic molecular structures of pyranine.

<Synthesis of receptor used for recovery of radioactive iodine (4)>
<Preparation of 1,5-diphenylthiocarbazone (dithizone) {1,5-Diphenylthiocarbazone (Dithizone)}>
FIG. 7 is a diagram showing a chemical formula of dithizone, a reaction formula when iodine is adsorbed to dithizone, and a visualization analysis (color change) by iodine adsorption in an aqueous solution. The transparent amber-colored dithizone aqueous solution changed to a transparent colorless liquid after adsorbing 2000 ppb (2 ppm) iodine. As shown in the chemical formula of FIG. 7, iodine (I) is incorporated between the cyclic molecular structures of dithizone.

<Synthesis of receptor used for recovery of radioactive iodine (5)>
<Preparation of 5- (4-Dimethylaminobenzylidene) rhodanine {5- (4-Dimethylaminobenzylidene) rhodanine (DMABR)}>
FIG. 8 is a diagram showing a chemical formula of the receptor DMABR, a reaction formula when iodine is adsorbed to the receptor DMABR, and a visualization analysis (color change) by iodine adsorption in an aqueous solution. The yellow transparent DMABR aqueous solution adsorbed 2000 ppb (2 ppm) iodine and then turned into a brown transparent liquid. As shown in the chemical formula of FIG. 8, iodine (I) is incorporated between the cyclic molecular structures of DMABR.

<Synthesis of probe used for recovery of radioactive iodine (6)>
<Production of Acid Red27>
FIG. 9 is a diagram showing a chemical formula of the receptor Acid Red 27, a reaction formula when iodine is adsorbed to the receptor Acid Red 27, and a visualization analysis (color change) by iodine adsorption in an aqueous solution. The transparent red-brown Acid Red 27 aqueous solution adsorbed 2000 ppb (2 ppm) of iodine, and then changed to a pink transparent liquid. As shown in the chemical formula of FIG. 9, iodine (I) is incorporated between the cyclic molecular structures of Acid Red27.

<Synthesis of probe used for recovery of radioactive iodine (7)>
<N, N, N ', N'-Tetramethyl-4,4'-diaminothiobenzophenone [Thiomylers ketone] {N, N, N', N'-Tetramethyl-4,4'-diaminothiobenzophenone [Thiomichler's Ketone (TK)]} Production>
FIG. 10 is a diagram showing a chemical formula of the receptor TK, a reaction formula when iodine is adsorbed to the receptor TK, and a visualization analysis (color tone change) of solid matter by iodine adsorption to TK in an aqueous solution. The color tone of the HOM-TK collector (solid) carrying TK on the HOM changed from green to amber after adsorbing 2000 ppb (2 ppm) iodine. As shown in the chemical formula of FIG. 10, iodine (I) is taken in between the TK cyclic molecular structures.

<Synthesis of HOM-probe material>
FIG. 11 is a diagram showing a method for manufacturing a HOM-TK collector. In FIG. 11, a method for producing a HOM-probe material using a TK probe is shown. 1.0 g of HOM1 was added to a solution containing 20 mg of TK dye dissolved in 30 ml of ethanol solution in a round flask and these mixtures were kept rotating at 60 ° C. for 2 hours. Connected to a rotary evaporator, ethanol was slowly evacuated and removed at 60 ° C. Within 2 hours, the viscous liquid changed to a colored gel (solid product) and became the shape and size of a round flask. This material was dried at 60-65 ° C. for 5 hours. The material was then washed with warm water and dried again until dry. This material HOM- a probe material (HOM-TK collector), iodine (I ₂₎ under various experimental conditions were used for extraction. (Note that the term probe is also used to adsorb (collect) specific element ions.) The production of the HOM-DSNPD collector is similar to that of the HOM-TK collector. In this case, dimethylformamide {N, N-Dimethylformamide (DMF)} was used instead of an ethanol solution.

<Investigation of optimum pH value for iodine ion extraction>
It is a very important step to investigate the most efficient adsorption and collection of iodine under the environmental conditions of HOM (HOM-iodine probe) loaded with iodine adsorption (collecting agent) agent (iodine collector) It is. We have investigated the optimal environmental conditions for iodine adsorption for HOM-TK and DSNPD collectors.

The efficiency of a radioactive iodine ion collector with nanopores is affected by the pH value. The reflection spectrum of the probe charge transfer complex was carefully monitored over a wide range of aqueous pH values. We investigated using eight pH aqueous solutions (1.0, 2.0, 3.5, 5.2, 7.0, 9.5, 11.0 and 12.5). A pH solution of either 0.01 M sulfuric acid or 0.2 M KCl—HCl was used for pH 2.0 and pH 3.5, and CH ₃ COOH—CH ₃ COONa was used to adjust pH 5.2. 3-morpholinopropane sulfonic acid {3-morpholinopropane sulfonic acid (MOPS)}, N-cyclohexyl-3-aminopropane sulfonic acid {N-cyclohexyl-3-aminopropane sulfonic acid (CAPS)} and 2- (cyclohexylamino) Mixtures of ethane sulfonic acid {2- (cyclohexylamino) ethane sulfonic acid (CHES)} were used for pH 7.0, 9.5 and 11.0, respectively, and the pH value was adjusted with 0.2 M NaOH.

4 ml of each pH solution was taken, 2 ppm iodine was added, and then an appropriate amount of water was added to make a 20 ml aqueous solution. Thereafter, an iodine extractant HOM-probe collector was added, and the mixture was stirred for 1 hour and filtered. The solid material after filtration is HOM-probe-I adsorbing iodine ions, that is, HOM-TK-I and HOM-DSNPD-I. The solid material after filtration was examined by UV-VIS-NIR Spectroscopy, and an absorbance spectrum was taken. Absorbance at a specific wavelength that specifically represents iodine adsorption was plotted for each solid material.

FIG. 12 is a graph showing the relationship between the UV-visible spectrum signal intensity (room temperature measurement) of HOM-TK-I and the pH value of the solution. From various pH value solutions in which 2 ppm of iodine ions were dissolved, HOM-TK Shows the pH value dependence of the absorbance of HOM-TK-I adsorbing iodine ions. In FIG. 12, the UV visible spectrum signal intensity (ratio) at a specific wavelength of HOM-TK-I is plotted on the vertical axis, and the pH value of a solution in which 2 ppm iodine ions are dissolved is plotted on the horizontal axis. The pH value solution with the highest signal intensity was used as the reference pH value. That is, the vertical axis in FIG. 12 represents the ratio to the signal intensity of an aqueous solution having a pH value of 2.0. Since it is known that the absorbance in the UV-visible spectrum increases as the amount of iodine in HOM-TK increases, as can be seen from FIG. 12, the signal intensity data is HOM− as an iodine ion collector (adsorbent). When TK is used, the best pH value that best adsorbs iodine ions is 2.0. Considering measurement errors and variations, a good pH value is 0.5 to 3.5, preferably 0.5 to 2.5, and optimally 1-2.

The color tone of HOM-TK at pH 2 is shown in the upper part of FIG. The case where iodine is contained (Optical HOM-TK-I2 with 2 ppm at pH2) and the case where iodine is not contained (HOM-TK at pH2) are shown. When iodine was not included, the color tone of HOM-TK was a green solid, but when it contained 2 ppm of iodine, it became an amber solid and the color changed.

FIG. 13 is a graph showing the relationship between the UV-visible spectrum signal intensity (room temperature measurement) of HOM-DSNPD-I and the pH value of the solution. From various pH value solutions in which 2 ppm of iodine ions are dissolved, HOM-DSNPD Shows the pH value dependence of the absorbance of HOM-DSNPD-I adsorbed with iodine ions. In FIG. 13, the UV-visible spectrum signal intensity (ratio) at a specific wavelength of HOM-DSNPD-I ₂ is plotted on the vertical axis, and the pH value of a solution in which 2 ppm of iodine ions is dissolved is plotted on the horizontal axis. The pH value solution with the highest signal intensity was used as the reference pH value. That is, the vertical axis in FIG. 13 represents a ratio to the signal intensity of an aqueous solution having a pH value of 5.2. Since it is known that the absorbance in the UV-visible spectrum increases as the amount of iodine in HOM-DSNPD increases, as can be seen from FIG. 13, the signal intensity data is HOM- as a collector (adsorbent) of iodine ions. When DSNPD is used, the best pH value that best adsorbs iodine ions is 5.2. Considering measurement errors and variations, a good pH value is 4 to 7, preferably 4.5 to 6, and most preferably 5.0 to 5.5.

Moreover, the color change of HOM-DSNPD in pH 5.2 is shown in the upper part of FIG. The case where iodine is contained (Optical HOM-DSNPD-I ₂ with 2 ppm at pH 5.2) and the case where iodine is not contained (HOM-DSNPD at pH 5.2) are shown. When iodine was not included, the color tone of HOM-DSNPD was a yellow solid, but when it contained 2 ppm of iodine, it became a cloudy green solid and the color tone changed.

<Investigation of sensitivity when iodine is extracted from iodine solutions of various concentrations using HOM1-TK and HOM1-DSNPD>
FIG. 14 is a diagram showing a procedure of an iodine ion extraction method when a HOM1-TK probe (HOM-TK collector) supported on HOM1 is used as an iodine remover. According to this procedure, various concentrations (1 ppb to 2 ppm) of iodine ions were added to a pH 2.0 solution that best adsorbs iodine ions, and an appropriate amount of deionized water was added to bring the volume to 20 ml. Thereafter, 20 mg of HOM1-TK was added and stirred for 1 hour, and the solution containing the solid material was filtered. This solid material is HOM1TK-I adsorbed with iodine. The solid material was examined by UV-VIS-NIR Spectroscopy and an absorbance spectrum was taken.

In addition, when using the HOM1-DSNPD probe supported by HOM1 as an iodine remover, iodine ions of various concentrations (0ppb to 12ppm) are adsorbed to the HOM1-DSNPD collector in the same manner as described above, and after filtration. The solid material (HOM1-DSNPD-I) was subjected to UV-VIS-NIR Spectroscopy, and an absorbance spectrum was taken. However, the pH value of the solution is set to a pH value of 5.2 at which the HOM1-DSNPD probe best adsorbs iodine.

Figure 15 is a diagram showing an absorption spectrum at room temperature of HOM1-TK-I ₂ in which the iodide ion concentration as a parameter. In FIG. 15, the horizontal axis represents the measurement wavelength, and the vertical axis represents the absorbance. As can be seen from FIG. 15, as the iodine ion concentration increases, the absorption spectrum intensity increases in almost all of the measurement wavelength region (250 nm to 900 nm). Therefore, if the ultraviolet visible spectrum measurement of HOM1-TK-I is performed, the iodine ion concentration in the solution can be known from the absorbance.

Actually, when the relationship between the absorbance and the iodine ion concentration is examined at the wavelength (λ = 639 nm) at which the absorbance is highest, which is related to iodine ion adsorption, it is as shown in FIG. That is, FIG. 16 is a graph showing the relationship between the iodine ion concentration in the solution with pH = 2.0 and the absorbance (λ = 639 nm) of the ultraviolet visible spectrum of HOM1-TK-I. (λ = 639 nm). Thus, it can be clearly understood that the absorbance of the UV-visible spectrum of HOM1-TK-I increases as the iodine ion concentration in the solution increases. In other words, the iodine ion concentration in the solution can be determined from the absorbance of the ultraviolet visible spectrum of HOM1-TK-I. Particularly in places where the iodine ion concentration is low (1 μM or less), the linearity is good as shown in the inner diagram of FIG. That is, the curve curve shown in FIG. 16 may be referred to as a calibration curve between absorption rate and concentration. Thus, the HOM probe (HOM1-TK) is an excellent collector and concentration sensor for iodine ions. These spectral changes are indicators of iodine (I) -receptor binding events, as TK forms a charge transfer complex. The measurement of the UV-visible spectrum was repeated 10 times, but there was almost no variation and the reproducibility was very good. The iodine ion concentration is calibrated based on a known sample.

FIG. 17 is a diagram showing an absorption spectrum and colorimetric analysis of HOM1-DSNPD-I at room temperature using iodine ion concentration as a parameter. In FIG. 17, the horizontal axis represents the measurement wavelength, and the vertical axis represents the absorbance. As can be seen from FIG. 17, as the iodine ion concentration (0-12 ppm) increases, the absorption spectrum intensity increases in almost all of the measurement wavelength region (250 nm to 900 nm). Therefore, if the ultraviolet visible spectrum measurement of HOM1-DSNPD-I is performed, the iodine ion concentration in the solution can be known from the absorbance.

Actually, when the relationship between the absorbance and the iodine ion concentration is examined at the wavelength (λ = 615 nm) related to iodine ion adsorption, it is as shown in FIG. 18 is a graph showing the relationship between the iodine ion concentration in the solution at pH = 5.2 and the absorbance (λ = 615 nm) of the UV-visible spectrum of HOM1-DSNPD-I. (λ = 615 nm) is a calibration curve. Thus, it can be clearly understood that the absorbance in the UV-visible spectrum of HOM1-DSNPD-I increases as the iodine ion concentration in the solution increases. In other words, the iodine ion concentration in the solution can be determined from the absorbance of the ultraviolet visible spectrum of HOM1-DSNPD-I. In particular, at a low iodine ion concentration (1 μM or less), the linearity is good as shown in the inner diagram of FIG. That is, the curve curve shown in FIG. 18 may be referred to as a calibration curve between absorption rate and concentration. Thus, the HOM probe (HOM1-DSNPD) is an excellent collector and concentration sensor for iodine ions. These spectral changes are indicators of the iodine (I) -receptor binding event because DSNPD forms a charge transfer complex. The measurement of the UV-visible spectrum was repeated 10 times, but there was almost no variation and the reproducibility was very good. The iodine ion concentration is calibrated based on a known sample. Furthermore, since HOM1-DSNPD can adsorb a large amount of iodine as shown in FIG. 17, it can efficiently collect iodine.

Figure 17 shows the relationship between the color tone of the iodine ion concentration and HOM-DSNPD-I _2, i.e. the data colorimetric is shown. As shown in FIG. 17, the color tone of the solid material after filtration increases gradually from yellow to dark yellow (iodine ion concentration 0 ppb, that is, the color tone of the HOM-DSNPD collector) as the iodine ion concentration increases. With an ion concentration of 100 ppb), the yellow color becomes darker (iodine ion concentration 1 ppm), green comes on, changes to light green yellow (iodine ion concentration 4 ppm), yellow-green (iodine ion concentration 8 ppm), green ( (Iodine ion concentration 12 ppm). Since this change in color tone is continuous, it is possible to know the iodine ion concentration from the color tone of the solid material {HOM5-DSNPD-iodine} after filtration. Thus, also from the result of colorimetric analysis, the HOM probe (HOM1-DSNPD) is an excellent collector and concentration detection sensor for iodine ions.

<Selectivity of HOM1-TK collector for iodine ion (Cation)>
A great advantage of HOM collectors is that they have selectivity for iodine ions in the iodine ion extraction system. Therefore, the HOM1-TK collector can prevent the interference of iodine ion extraction from active interference components such as cations and anions shown in FIG. In the presence of numerous cations, the selectivity of the HOM-TK collector for iodine ion adsorption was investigated in the presence of numerous cations, since there are numerous interfering components that may coexist with iodine in the actual wastewater and environment. Under specific pH conditions of 2.0, the effect of adding high concentrations of various cations was investigated in the extraction system described above. The experiment was carried out at room temperature (25 ° C.), and 2 ppm iodine and various active species were added individually, and an aqueous solution having a total volume of 20 ml was used. After this, 20 mg of HOM-TK collector was added and stirred for 1 hour. After stirring, the solid material obtained after filtering the solution was quantitatively analyzed using UV-VIS-NIR Spectroscopy.

Various heteroactive cations (K ⁺ , Li ⁺ , Ca ²⁺ , Mg ²⁺ , Na ⁺ , Al ³⁺ , Cu ²⁺ , Ni ²⁺ , Mn ² are added to a solution of pH 2.0 that best extracts iodine ions. ⁺ , Zn ²⁺ , Co ²⁺ , Cd ²⁺ , Pd ²⁺ , Sr ²⁺ , Bi ³⁺ , and Mo ⁶⁺ ) were added individually. A HOM-TK collector was added to this solution, and a solid material was obtained after filtration. For comparison, an additive solution containing only iodine ions and a solution containing nothing added were also prepared. All operations were performed at 25 ° C. FIG. 19 is a diagram showing UV-VIS-NIR analysis data and color tone data of a solid obtained after immersing HOM1-TK in a solution containing various metal ions including iodine ions. The cations contained in the solution are the following substances corresponding to the numbers in the figure. That is, the numbers in the figure are (1) 4.0 ppm K ⁺ , (2) 4 ppm Li ⁺ , (3) 5.0 ppm Ca ²⁺ , (4) 4.0 ppm Mg ²⁺ , (5) 4.0 ppm Na, (6 ) 4.0 ppm Al ³⁺ , (7) 4.0 ppm Cu ²⁺ , (8) 3.5 ppm Ni ²⁺ , (9) 4.5 ppm Mn ²⁺ , (10) 4.0 ppm Zn ²⁺ , (11) 4.0 ppm Co ^{2 +} , (12) 4.0 ppm Cd ²⁺ , (13) 4.0 ppm Pb ²⁺ , (14) 3.5 ppm Sr ² , (15) 4.0 ppm Bi ³⁺ , (16) 4.0 ppm Mo ⁶⁺ , (17) 2 ppm Iodine ions, and (18) HOM-TK probe.

As can be seen from FIG. 19, there is almost no change in the data of the UV-VIS-NIR spectrum even if the metal ions (1) to (16) other than iodine ions are included, and the color tone data. There is almost no change in color tone as well (it remains light green). Therefore, HOM1-TK does not adsorb metal ions other than iodine ions. This is in contrast to the fact that UV-VIS-NIR spectrum data immersed in a solution containing only iodine ions gives a large absorption spectrum. In contrast, the color tone changes to amber. Moreover, from the data of ICP-OES (ICP emission spectroscopic analysis), each filtrate contained only the above metal ions other than iodine ions. This also shows that HOM1-TK hardly adsorbs metal ions other than iodine ions.

Further, HOM1-TK immersed in a solution containing all the cations of (1) to (17) above had the same absorption spectrum as sample (17). Moreover, from the data of ICP-OES (ICP emission spectroscopic analysis), the filtrate contains only the above metal ions other than iodine ions, and their concentrations are contained in the solution before soaking HOM1-TK. It was almost the same as the metal ion concentration. From the above, it was confirmed that HOM1-TK has very high selectivity for cations with respect to iodine ions, and that adsorption of iodine ions is hardly influenced by cations other than iodine ions. Furthermore, the color tone when the HOM-TK collector was immersed in a solution containing iodine ions (2 ppm) and all of the above metal ions changed from a light green color to an amber color as in the case of containing only iodine ions (2 ppm). From this color tone change, it can be seen that the iodine ion adsorption of the HOM-TK collector is not affected by the coexisting metal ions.

<Selectivity of HOM1-TK collector for iodine ion (anion)>
A great advantage of HOM collectors is that they have selectivity for iodine ions in the iodine ion extraction system. Therefore, the HOM1-TK collector can prevent the interference of iodine ion extraction from active interference components such as the anion shown in FIG. The selectivity of the HOM-TK collector was investigated in the presence of numerous interfering components that could coexist with iodine in wastewater and the environment. Under specific pH conditions of 2.0, in the above extraction system, various concentrations of various anions {sodium dodocylsulfate (SDS)}, cetyltrimethylammonium bromide {Cetyl trimethylammonium bromide (CTAB)}, tartrate (tartaric acid) Ester), citrate, oxalate, chloride, acetate, nitrate, sulfate, and carbonate} The effect of was investigated. For comparison, an iodine ion added solution and a solution to which nothing was added were also prepared. The experiment was carried out at room temperature (25 ° C.), and 2 ppm iodine and various active species were added individually, and an aqueous solution having a total volume of 20 ml was used. After this, 20 mg of HOM collector was added and stirred for 1 hour. After stirring, the solid material obtained after filtering the solution was quantitatively analyzed using UV-VIS-NIR Spectroscopy.

FIG. 20 is a diagram showing UV-VIS-NIR analysis data and color tone data of a solid obtained after immersing HOM1-TK in a solution containing iodine ions, various anions or surfactants. The anions or surfactants contained in the solution are the following substances corresponding to the numbers in the figure. That is, the numbers in the figure are (1) SDS, (2) CTAB, (3) tartrate, (4) citrate, (5) oxalate, (6) chloride, (7) acetate, (8) sulfate, (9) nitrate, (10) carbonate, (11) iodine, and (12) nothing. As can be seen from FIG. 20, even when the anions or surfactants (1) to (10) other than iodine ions are included, the data of the UV-visible spectrum hardly changes. That is, the spectrum (absorbance) data of only HOM1-TK (which does not adsorb anything) and the spectrum (absorbance) data of HOM1-TK soaked in each anion or surfactant are the same. Compared to (absorbance) data, the spectrum (absorbance) data of HOM1-TK-I immersed in an iodine ion solution and adsorbed with iodine is extremely large. As for the color tone data (except for the case of only iodine ions), there is almost no change in color tone. Therefore, it was found that HOM1-DSNPD hardly adsorbs anions and surfactants, and hardly affects or interferes with them.

Further, HOM1-TK immersed in a solution containing all the anions and surfactants of (1) to (12) above had the same absorption spectrum as that of sample (11). Moreover, from the data of ICP-OES (ICP emission spectroscopic analysis), the filtrate contained almost no iodine ions. From the above, it was confirmed that HOM1-TK has very high selectivity for iodine ions with respect to anions and the like, and the adsorptivity of iodine ions is hardly influenced by many anions other than iodine ions. Furthermore, when the HOM-TK collector is immersed in a solution containing iodine ions (2 ppm) and all of the above anions, the color tone changes from light green to amber, just as when iodine ions (2 ppm) are included. did. From this color tone change, it can be seen that the iodine ion adsorption of the HOM-TK collector is not affected by the coexisting anions.

<Selective removal of iodine (I) from an iodine-dissolved solution containing multiple ions using a HOM-DSNPD collector>
Take 2 ml of pH 5.2 solution and add cations (Na ⁺ , K ⁺ , Ca ²⁺ , Ce ³⁺ ), anions (Cl ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ ) and iodine, then the required amount Was added to make 10 ml with a glass test tube. For this multi-ion mixed aqueous solution, the iodine ion concentration is 4 ppm, and the other ion concentrations are i) 4 ppm Na ⁺ , K ⁺ , Ca in each {NaCl, KCl, CaCl ₂ and Ce (NO ₃ ) ₃ }. ²⁺ , Ce ³⁺ , ii) In each {NaCl, NaNO ₃ , Na ₂ SO ₄ }, 4 ppm of Cl ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ . Then 10 mg of HOM-DSNPD collector was added with shaking for 1 hour at room temperature. The aqueous solution was then filtered and the solid material was used for UV-VIS-NIR analysis. From the ICP-OES analysis (ICP emission spectroscopic analysis) of the filtered solution, the filtered solution contained almost no iodine and other ions other than iodine.

Iodine present in the solid material was investigated by ultraviolet-visible spectroscopy (UV-VIS-NIR) spectrum. FIG. 21 is a diagram showing a UV-visible spectrum by a HOM-DSNPD collector in the presence of a cation and an anion and a color change of the HOM-DSNPD collector. When iodine ions are adsorbed with respect to the spectrum of the HOM-DSNPD collector on which nothing is adsorbed, the absorbance increases within a wide wavelength range of ultraviolet visible light of 250 nm to 850 nm. As for the color tone, the yellow color tone of the HOM-DSNPD collector that has not adsorbed anything changes to a yellow-green color tone when iodine is adsorbed. In the case of the HOM-DSNPD collector, when both cation and anion are present, the absorbance tends to increase slightly around the peak value of 300-400 nm, but there is almost no difference in absorbance at the wavelength of 615 nm involved in iodine adsorption. Also, there is not much change in color tone. However, the difference in the vicinity of the peak value of the absorbance of 300 to 400 nm is also within the allowable limit, and is a level that does not cause a problem even if something other than iodine (cation or anion) is included.

That is, it can be seen that iodine adsorption of the HOM-DSNPD collector is hardly influenced by both anions and cations, and even when coexisting with a surfactant. Therefore, it can be judged that the HOM-DSNPD collector is also very excellent in iodine ion adsorption selectivity. In particular, with respect to adsorption (collection) of trace amounts of iodine, the sensitivity is good and the selectivity is also good. Since the HOM-DSNPD collector (collecting agent) can collect all the iodine in the solution and completely remove iodine, it can be said to be a complete iodine collecting agent or a complete iodine removing agent.

<Elution of iodine from HOM-DSNPD-I / back extraction>
After immersing the HOM-DSNPD collector in a solution containing 8 ppm iodine to remove (extract) 8 ppm iodine and filtering, the solid material was placed in a 20 ml elution aqueous solution (2.0 M HCl aqueous solution) in a 50 ml beaker, Stir for 2 hours. This liquid was filtered and separated into a solid material and a filtrate. FIG. 22 is a diagram showing a change in color tone and an ultraviolet-visible spectrum change in elution / back-extraction of iodine (HOM-DSNPD-I) adsorbed on a HOM-DSNPD collector by a 2.0 M HCl solution. As shown in FIG. 22, when iodine is adsorbed to the HOM-DSNPD collector, the absorbance of the UV-visible spectrum increases at all wavelengths of 250 nm to 850 nm. In particular, an increase in the peak at 615 nm indicating iodine adsorption is characteristic. That is, the HOM-DSNPD collector was changed to HOM-DSNPD-I. By contacting (immersing) this with HCl, the absorbance in the UV-visible spectrum decreases at all wavelengths of 250 nm to 850 nm, and the peak at 615 nm, which indicates iodine adsorption in particular, disappears (element adsorbs). Returning to the previous state. That is, iodine separated from HOM-DSNPD-I and changed to HOM-DSNPD.

Regarding the color tone of HOM-DSNPD, the color tone changes from a light yellow color of HOM-DSNPD not adsorbing iodine to green color (8 ppm I ₂ ) by iodine adsorption (HOM-DSNPD-I). Furthermore, when this is immersed in HCl, it returns to the original color tone (light yellow). From the ICP-OES analysis (ICP emission spectroscopic analysis) of the filtered solution, the filtered solution contained an amount of iodine originally contained in the solution. From the above, it can be said that most of the iodine in HOM-DSNPD-I ₂ was separated (eluted) by the HCl aqueous solution, dissolved in the HCl aqueous solution, and the solid returned to HOM-DSNPD. This restored HOM-DSNPD can be used again for iodine extraction. This separation (elution) of iodine is the reverse of the process in which HOM-DSNPD extracts iodine from a liquid containing iodine and changes to HOM-DSNPD-I, and thus may be called back extraction.

If HOM-DSNPD is used, iodine can be repeatedly extracted (adsorbed or collected) and eluted (separated or back extracted), so that iodine can be recovered efficiently, inexpensively and rapidly. Furthermore, since it can be applied to iodine at a low concentration level of ppb to ppm level, even a very small amount of radioactive iodine can be removed from waste water or the environment.

<Elution of iodine from HOM-TK collector / back extraction>
After immersing the HOM-TK collector in a solution containing 5 ppm iodine to remove (extract) 5 ppm iodine and filtering, the solid material was placed in a 20 ml elution aqueous solution (0.025 M NaOH aqueous solution) in a 50 ml beaker, Stir for 2 hours. This liquid was filtered and separated into a solid material and a filtrate. FIG. 23 is a diagram showing a change in color tone of elution / back-extraction of iodine (HOM-TK-I) adsorbed on a HOM-TK collector by a 0.025 M NaOH solution. As shown in FIG. 23, the color tone of HOM-TK that does not adsorb iodine is green, but the color tone changes to amber (5 ppm I ₂ ) by iodine adsorption (HOM-TK-I). Furthermore, when this is immersed in NaOH solution, it returns to the original color (light green). It returns to the original spectrum (of HOM-TK not adsorbing iodine) from the UV-visible spectroscopic measurement data.

Further, from the ICP-OES analysis (ICP emission spectroscopic analysis) of the filtered solution, the filtered solution contained an amount of iodine originally contained in the solution. From the above, it can be said that most of the iodine in the HOM-TK-I was separated (eluted) by the NaOH aqueous solution, dissolved in the NaOH aqueous solution, and the solid returned to the HOM-TK. This restored HOM-TK can be used again for iodine extraction. This separation (elution) of iodine is the reverse of the process in which HOM-TK extracts iodine from a liquid containing iodine and changes to HOM-TK-I. If HOM-TK is used, iodine can be extracted (adsorbed or collected) and eluted (separated or back extracted) repeatedly, so that iodine can be recovered efficiently, inexpensively and rapidly. Furthermore, since it can be applied to iodine at a low concentration level of ppb to ppm level, even a small amount of radioactive iodine can be removed from waste water or environmental water.

<Iodine recovery rate from iodine-dissolved solution containing multiple metal ions>
Iodine ions (concentration 2 ppm) and multiple metal ions ((K ⁺ , Li ⁺ , Ca ²⁺ , Mg ²⁺ , Na ⁺ , Al ³⁺ , Cu ²⁺ , Ni ²⁺ , Mn ²⁺ , Zn ²⁺ , Co) ²⁺ , Cd ²⁺ , Pd ²⁺ , Sr ²⁺ , Bi ³⁺ , and Mo ⁶⁺ ) (concentration of 2 ppm each), so that HOM-TK is immersed in the aqueous solution, and each ion contained in the filtrate The concentration is measured using ICP-OES analysis (ICP emission spectroscopic analysis). Further, the solid material after filtration (HOM-KI) is immersed in a NaOH solution to dissolve iodine, and each ion of the solution is dissolved. The concentration was measured using ICP-OES analysis (ICP emission spectroscopic analysis) Fig. 24 shows the measurement results of the concentration of each ion before and after immersing HOM-TK in a solution containing a plurality of ions, and HOM-TK-I. It is a table | surface which shows the measurement result of the density | concentration of each ion in the solution after eluting iodine with the NaOH solution from.

In FIG. 24, (1) is the concentration of each ion before iodine removal in the multiple ion dissolution solution. Each ion (I ⁻ , K ⁺ , Li ⁺ , Ca ²⁺ , Mg ²⁺ , Na ⁺ , Al ³⁺ , Cu ²⁺ , Ni ²⁺ , Mn ²⁺ , Zn ²⁺ , Co ²⁺ , Cd ²⁺ , Pd ²⁺ , Sr ²⁺ , Bi ³⁺ , and Mo ⁶⁺ ) were both at a concentration of 2 ppm. (2) is the concentration of each ion in the filtrate after iodine removal by the HOM-TK collector, but the concentration of all metal ions did not change from the concentration before iodine removal. However, iodine ions were not detected, and all iodine in the iodine ion-dissolved solution was adsorbed (collected and extracted) on the HOM-TK collector. However, no other metal ions were adsorbed at all. (3) is the concentration of each ion in the NaOH solution after elution of iodine from HOM-TK-I. After elution, the iodine concentration was 1.89 ppm, and no other metal ions were detected. From the above, the iodine recovery efficiency is about 95%. Considering measurement errors and environmental conditions, it can be said that the recovery rate is very high. Furthermore, if the conditions are optimized, a 100% recovery rate is possible. Moreover, since metal ions other than iodine are not adsorbed at all, the selectivity is very good. Therefore, the iodine collection and recovery system using the HOM-TK collector of the present invention is an extremely excellent method.

<Iodine recovery rate from iodine-dissolved solution containing multiple ions>
Immerse HOM-DSNPD in an aqueous solution containing iodine ions (concentration 4 ppm) and multiple ions (Na ⁺ , K ⁺ , Ca ²⁺ , Ce ²⁺ , Cl ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ ) (concentration 4 ppm each). Then, the concentration of each ion contained in the filtrate is measured using ICP-OES analysis (ICP emission spectroscopy), and the solid material after filtration (HOM-DSNPD-I) is immersed in an HCl solution. Then, iodine was dissolved, and each ion concentration of the dissolved solution was measured using ICP-OES analysis (ICP emission spectroscopic analysis). FIG. 25 shows the measurement results of the concentration of each ion before and after immersing HOM-DSNPD in a solution containing a plurality of ions, and the concentration of each ion in the solution after elution of iodine from HOM-DSNPD-I with an HCl solution. It is a table | surface which shows a measurement result.

In FIG. 25, (1) is the concentration of each ion before iodine removal in the multiple ion dissolution solution. Each ion (I ⁻ , Na ⁺ , K ⁺ , Ca ²⁺ , Ce ²⁺ , Cl ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ ) had a concentration of 4 ppm. (2) is the concentration of each ion in the filtrate after iodine removal by the HOM-DSNPD collector, but the concentration of all ions other than iodine was unchanged from the concentration before iodine removal. However, iodine was not detected, and all iodine in the iodine ion solution was adsorbed (collected and extracted) to the HOM-DSNPD collector, and ions other than iodine were not adsorbed. (3) is the concentration of each ion in the HCl solution after elution of iodine from HOM-DSNPD-I. After elution, the iodine concentration was 3.4 ppm, and no other ions were detected. From the above, the iodine recovery efficiency is about 85%. Considering measurement errors and environmental conditions, it can be said that the recovery rate is very high. Furthermore, if the conditions are optimized, a 100% recovery rate is possible. In addition, since the cation and anion other than iodine are not adsorbed at all, the selectivity is very good. Therefore, the iodine collection and recovery system using the HOM-DSNPD collector of the present invention is an excellent method.

FIG. 26 is a table showing the applicable range of the HOM1-DSNPD collector and HOM1-TK collector of the present invention obtained from the above examples. When the HOM1-DSNPD collector or HOM1-TK collector is immersed in an iodine ion dissolution solution, the response time for adsorbing iodine ions of the HOM1-DSNPD collector or HOM1-TK collector is about 2 minutes, and the visual extraction limit is 5.1 × 10 ^{− 8} (mol.dm-3) or 7.5 × 10 ⁻⁸ (mol.dm-3), the visual extraction range is 0.001 to 12.0 ppm or 0.0002 to 2.0 ppm, respectively. The required amount of HOM1-DSNPD collector and HOM1-TK collector that adsorbs 1 g of iodine is 20 g. Further, HOM1-DSNPD-I or HOM1-TK-I adsorbed with iodine returns to the original HOM1-DSNPD or HOM1-TK using HCl solution or NaOH as the elution solution, respectively. Moreover, since the HOM1-DSNPD collector and the HOM1-TK collector have a stable structure of the HOMS skeleton and can be used repeatedly, a large amount of iodine can be recovered with a small amount of material.

FIG. 27 is a view showing a system for recovering iodine (I) from an iodine ion-dissolved solution containing radioactive iodine and the like using mesoporous silica (HOMS) supporting DSNPD or TK of the present invention. In the first stage, mesoporous silica (HOMS) is produced, and in the second stage, the iodine-adsorbing compound DSNPD or TK is supported on HOMS to produce a HOMS-DSNPD collector or a HOMS-TK collector. Next, in the third stage, HOMS-DSNPD or HOMS-TK is immersed in an iodine (ion) -dissolved solution containing iodine (which naturally contains radioactive iodine), and the target element to be extracted (or collected) Certain iodine is adsorbed (extracted and collected) on HOMS-DSNPD or HOMS-TK to produce HOMS-DSNPD-I or HOMS-TK-I. In the next fourth stage (fifth stage in FIG. 1), the target element iodine is separated by immersing this HOMS-DSNPD-I or HOMS-TK-I in an iodine elution solution such as an acidic solution or an alkaline solution. To do. Through this series of operations, iodine was collected or collected. HOMS-DSNPD or HOMS-TK-I can be used again in the third stage and can be used any number of times by reusing HOMS-DSNPD or HOMS-TK.

From the viewpoint of the colorimetric method, the color tone of the HOMS-DSNPD collector or HOMS-TK collector changes in the iodine ion solution in the third stage. This change in color varies depending on the iodine ion concentration of the iodine ion solution. Alternatively, the color tone of the HOMS-DSNPD collector or the HOMS-TK collector varies depending on the concentration of iodine ions adsorbed thereto. Since the iodine ion adsorption speed to the HOMS-DSNPD collector or HOMS-TK collector is about several minutes, the HOMS-DSNPD collector (becomes HOMS-DSNPD-I) by filtration or the like when the color change is completed or Separate the HOMS-TK collector (becomes HOMS-TK-I). This indicates that iodine ions in the iodine ion dissolution solution were collected by the HOMS-DSNPD collector or the HOMS-TK collector. When these HOMS-DSNPD-I or HOMS-TK-I are brought into contact with an elution (free, separated) solution capable of separating iodine from them, the color of the HOMS-DSNPD collector or HOMS-TK collector changes again, and the original color is changed. Return to the color tone. That is, it returned to HOMS-DSNPD or HOMS-TK that did not adsorb iodine. The HOMS-DSNPD collector and the HOMS-TK collector have extremely high iodine ion extraction selectivity, and even if a large number of ions are contained, there is almost no effect on the effect and almost no influence on the color tone change of the solid matter. Don't give. Therefore, the HOMS-DSNPD collector and the HOMS-TK collector can collect all the iodine in the solution and can completely remove the iodine, so that they can be said to be a complete iodine collector or a complete iodine remover. In this way, the HOM5-DSNPD collector can be used many times for the recovery of iodine ions using a colorimetric method.

It is possible to know how much iodine ions have been adsorbed by the HOM-DSNPD collector or the HOMS-TK collector using the color change by the colorimetric method. For example, when HOM-DSNPD adsorbs iodine, it changes color to HOM-DSNPD-I, and the yellow color gradually increases from pale yellow (iodine ion concentration 0 ppb, that is, the color tone of the HOM-DSNPD collector) to yellow (iodine ion concentration 100 ppb). As the yellow color becomes deeper (iodine ion concentration: 1 ppm), green follows, changes to light green yellow (iodine ion concentration: 4 ppm), and further changes to green yellow (iodine ion concentration: 12 ppm). The adsorption concentration of iodine can be determined from the degree of change in the color tone.

Also, if the HOM-DSNPD collector is immersed in an iodine ion dissolution solution and the HOM-DSNPD collector ends in a light yellow green color, 4 ppm or more of iodine ions are adsorbed. Can be removed, the HOM-DSNPD collector can be removed from the aqueous solution, and iodine ions can be eluted from the HOM-DSNPD-I. When HOM-DSNPD-I is put into the iodine ion elution solution, the iodine is eluted and discolors to become HOM-DSNPD, which changes from light yellowish green to light yellow, to the HOM-DSNPD collector that does not adsorb iodine ions. Return. It can be confirmed from ICP-OES measurement that iodine ions are completely removed. In this way, the amount of iodine ion adsorption can be determined using the colorimetric method, and the end point can be detected. The HOM-DSNPD collector is reversible for extraction / separation of iodine ions. Thus, since the adsorption amount of iodine ions can be grasped only by the color tone, or it can be grasped that iodine ions are not adsorbed, not only rapid detection of iodine ions but also rapid recovery can be performed. As a result, productivity can be greatly improved. The same applies to the HOM-TK collector. As described above, the HOM-TK collector, the HOM-DSNPD collector, and the like can extract (collect) iodine using the change in color tone (colorimetric method), and thus can be called a visual collector. In addition, the color change (colorimetric method) and the above-described spectroscopic method can be automated to construct an automatic recovery system and perform continuous processing.

HOMS-DSNPD, HOMS-TK, or HOMS carrying other iodine ion-adsorptive compounds as described above has very high selectivity, so even if metals other than iodine ions are contained in the iodine ion solution, Alternatively, even if an anion ion or a surfactant is contained in the iodine ion solution, that is, even if these competing ions are present, the selectivity is very good, and only iodine ions are extracted or collected. Even if the amount of iodine ion is contained in a trace amount of ppb to ppm level or in a large amount, and even if the content of other metal ions, anions or surfactants is contained in a trace amount or in a large amount, the present invention HOMS-DSNPD, HOMS-TK, etc. can selectively extract or collect only iodine ions.

One of the features of the present invention is that the inner wall of the mesoporous material is composed of an arbitrary composite oxide to create a state in which different kinds of atoms are aligned, and an appropriate chelate or compound is fixed thereto, thereby sensing and collecting. Is to do The iodine ion collectors such as HOM5-DSNPD and HOMS-TK produced using the technology of the present invention visually change when iodine is adsorbed from waste (drainage) liquid containing radioactive iodine, etc. or domestic (drainage) water. Therefore, iodine can be easily recovered. Moreover, collectors such as HOM5-DSNPD and HOMS-TK have high selectivity for iodine ions among various ions and have an optical response function. The collectors such as HOM5-DSNPD and HOMS-TK of the present invention are extremely useful for extraction, removal, collection, recovery and detection of radioactive iodine, which is particularly dangerous to the human body.

As described above, the present invention supports highly ordered mesoporous silica prepared from an organosilicon compound and a surfactant with an iodine ion adsorbing compound such as a chelate compound that selectively adsorbs the target element iodine ion. Then, the mesoporous silica supporting the iodine ion adsorbing compound is brought into contact with a solution in which the target element iodine ion is dissolved, and the target element iodine ion is selectively converted into the iodine ion adsorbing compound supported on the mesoporous silica. Adsorb. Thereafter, the mesoporous silica supporting the iodine ion adsorptive compound adsorbing the target element iodine ions is chemically treated to release the target element iodine ion from the mesoporous silica supported iodine ion adsorbing compound, Collect iodine, which is the target element. The mesoporous silica supporting the iodine ion-adsorbing compound from which the target element iodine ion is released can be reused. The mesoporous silica supporting the iodine ion adsorbing compound can also be used as an iodine (ion) collector and a concentration detection sensor. Furthermore, it is possible to inspect whether (hazardous radioactive) iodine is dissolved in domestic water or waste liquid, and it is possible to detect even a minute concentration of the order of ppb to ppm. Furthermore, (radioactive) iodine dissolved in domestic water or waste liquid can be adsorbed to reduce the (radioactive) iodine concentration to a very small concentration. In terms of radioactivity level, it can be reduced below the allowable limit. Therefore, it can also be used as a (radioactive) iodine removal filter.

In addition, it cannot be overemphasized that the said content can be applied to the said other part regarding that it can apply without contradiction also to the other part which did not describe the content described and demonstrated in a certain part of the specification. Moreover, the said embodiment and an Example are examples, and it can be carried out by changing variously within the range which does not deviate from a summary, and it cannot be overemphasized that the right range of this invention is not limited to the said embodiment.

The present invention can be used in industrial fields related to iodine collectors and sensors, industrial fields in which iodine is removed from substances and materials containing various cations, anions and surfactants, and industrial fields in which iodine is recovered.

Claims (18)

An iodine ion-adsorbing compound that adsorbs iodine ions and can release the adsorbed iodine ions from a solution (iodine ion-dissolved solution) in which various ions containing iodine as the target element are dissolved. A mesoporous silica bonded with
The iodine ion adsorbing compound is:
N, N`-bis (salicylidine) 2-mercaptopyrimidine-4-ol-5,6-diamine {N, N` Bis (salicylidine) 2-mercaptopyriminidin-4-ol-5,6diamine (BSCPD)},
N, N`-disalicylidene-4-nitro-phenylenedene {N, N-disalicylidene-4-nitro-phenylenedene (DSNPD)},
Trisodium 8-hydroxypyrene-1,3,6-3 sulfonate (pyranine) {Trisodium 8-hydroxypyrene-1,3,6-trisulfonate (Pyranine)},
1,5-diphenylthiocarbazone (dithizone) {1,5-Diphenylthiocarbazone (Dithizone)},
5- (4-dimethylaminobenzylidene) rhodanine {5- (4-Dimethylaminobenzylidene) rhodanine (DMABR)},
Acid Red 27, or
N, N, N ', N'-Tetramethyl-4,4'-diaminothiobenzophenone {Thiomichler's Ketone (TK)}
Mesoporous silica, which is one or more compounds selected from The mesoporous silica bonded with the iodine ion adsorbing compound is brought into contact with an iodine ion dissolving solution adjusted to a pH value at which the target element iodine is adsorbed to the maximum, and the iodine ion adsorbing compound bonded to the mesoporous silica is brought into contact with the iodine ion adsorbing compound. The mesoporous silica according to claim 1, wherein iodine ions which are target elements are adsorbed. The pH value is 4.0 to 7.0 in the case of the DSNPD, and the pH value is 0.1 to 3.5 in the case of the TK. Mesoporous silica. The color tone of the mesoporous silica bonded with the iodine ion-adsorbing compound before adsorbing iodine is changed by adsorbing iodine, and further returns to the original color when iodine is separated. 4. The mesoporous silica according to any one of 3 above. An iodine collector that collects iodine from an iodine ion-dissolved solution using the mesoporous silica according to any one of claims 1 to 4. The iodine collector according to claim 5, wherein the iodine collected with the iodine ion dissolving solution contains radioactive iodine. Mesoporous silica bonded with iodine ion-adsorbing compound is brought into contact with an iodine ion-dissolved solution containing iodine ions as the target element, adjusted to a pH value that adsorbs more iodine ions as the target element than other pH values. A step of adsorbing iodine ions as a target element to the iodine ion adsorbing compound,
A method for recovering iodine using mesoporous silica, comprising a step of releasing iodine ions as a target element from the iodine ion-adsorbing compound that adsorbs iodine ions as a target element,
The iodine ion adsorbing compound is:
N, N`-bis (salicylidine) 2-mercaptopyrimidine-4-ol-5,6-diamine {N, N` Bis (salicylidine), 2-mercaptopyriminidin-4-ol-5,6diamine (BSCPD)} ,
N, N`-disalicylidene-4-nitro-phenylenedene {N, N-disalicylidene-4-nitro-phenylenedene (DSNPD)},
Trisodium 8-hydroxypyrene-1,3,6-3 sulfonate (pyranine) {Trisodium 8-hydroxypyrene-1,3,6-trisulfonate (Pyranine)},
1,5-diphenylthiocarbazone (dithizone) {1,5-Diphenylthiocarbazone (Dithizone)},
5- (4-dimethylaminobenzylidene) rhodanine {5- (4-Dimethylaminobenzylidene) rhodanine (DMABR)},
Acid Red27,
Or N, N, N ', N'-tetramethyl-4,4'-diaminothiobenzophenone {Thiomichler's Ketone (TK)}
A method for recovering iodine using mesoporous silica, wherein the compound is one or more compounds selected from the group consisting of: The iodine recovery method according to claim 7, further comprising a step of binding the iodine ion-adsorbing compound to mesoporous silica. The iodine recovery method according to claim 7 or 8, further comprising a step of determining a concentration of iodine ions adsorbed on mesoporous silica bound with the iodine ion adsorbing compound using a colorimetric method. The iodine recovery method according to any one of claims 7 to 9, wherein the mesoporous silica bonded with the iodine ion adsorbing compound is reused. The pH value is 4.0 to 7.0 in the case of the DSNPD, and the pH value is 0.1 to 3.5 in the case of the TK. The iodine collection | recovery method of any one of these. Extracting iodine ions by using the mesoporous silica bonded with the iodine ion adsorbing compound to discolor when adsorbing iodine ions, and / or discoloring when the mesoporous silica adsorbing iodine ions elutes iodine ions The iodine recovery method according to any one of claims 7 to 11, wherein iodine ions are separated by returning to mesoporous silica bonded with an iodine ion-adsorbing compound. An iodine ion collector based on mesoporous silica combined with an iodine ion adsorbing compound that collects iodine ions even in the presence of competing ions,
The iodine ion adsorbing compound is:
N, N`-bis (salicylidine) 2-mercaptopyrimidine-4-ol-5,6-diamine {N, N` Bis (salicylidine) 2-mercaptopyriminidin-4-ol-5,6diamine (BSCPD)},
N, N`-disalicylidene-4-nitro-phenylenedene {N, N-disalicylidene-4-nitro-phenylenedene (DSNPD)},
Trisodium 8-hydroxypyrene-1,3,6-3 sulfonate (pyranine) {Trisodium 8-hydroxypyrene-1,3,6-trisulfonate (Pyranine)},
1,5-diphenylthiocarbazone (dithizone) {1,5-Diphenylthiocarbazone (Dithizone)},
5- (4-dimethylaminobenzylidene) rhodanine {5- (4-Dimethylaminobenzylidene) rhodanine (DMABR)},
Acid Red27,
Or N, N, N ', N'-tetramethyl-4,4'-diaminothiobenzophenone {Thiomichler's Ketone (TK)}
An iodine ion collector, which is one or more compounds selected from the group consisting of: An iodine ion concentration sensor based on mesoporous silica bonded with an iodine ion adsorbing compound, wherein the iodine ion concentration is detected by a color change (colorimetric method) .
The iodine ion adsorbing compound is:
N, N`-bis (salicylidine) 2-mercaptopyrimidine-4-ol-5,6-diamine {N, N` Bis (salicylidine) 2-mercaptopyriminidin-4-ol-5,6diamine (BSCPD)},
N, N`-disalicylidene-4-nitro-phenylenedene {N, N-disalicylidene-4-nitro-phenylenedene (DSNPD)},
Trisodium 8-hydroxypyrene-1,3,6-3 sulfonate (pyranine) {Trisodium 8-hydroxypyrene-1,3,6-trisulfonate (Pyranine)},
1,5-diphenylthiocarbazone (dithizone) {1,5-Diphenylthiocarbazone (Dithizone)},
5- (4-dimethylaminobenzylidene) rhodanine {5- (4-Dimethylaminobenzylidene) rhodanine (DMABR)},
Acid Red27,
Or N, N, N ', N'-tetramethyl-4,4'-diaminothiobenzophenone {Thiomichler's Ketone (TK)}
An iodine ion concentration sensor, wherein the compound is one or more compounds selected from the group consisting of: Iodine ion concentration sensor based on mesoporous silica combined with iodine ion adsorbing compound, characterized by detecting iodine ion concentration by UV-VIS-NIR spectroscopy A sensor ,
The iodine ion adsorbing compound is:
N, N`-bis (salicylidine) 2-mercaptopyrimidine-4-ol-5,6-diamine {N, N` Bis (salicylidine) 2-mercaptopyriminidin-4-ol-5,6diamine (BSCPD)},
N, N`-disalicylidene-4-nitro-phenylenedene {N, N-disalicylidene-4-nitro-phenylenedene (DSNPD)},
Trisodium 8-hydroxypyrene-1,3,6-3 sulfonate (pyranine) {Trisodium 8-hydroxypyrene-1,3,6-trisulfonate (Pyranine)},
1,5-diphenylthiocarbazone (dithizone) {1,5-Diphenylthiocarbazone (Dithizone)},
5- (4-dimethylaminobenzylidene) rhodanine {5- (4-Dimethylaminobenzylidene) rhodanine (DMABR)},
Acid Red27,
Or N, N, N ', N'-tetramethyl-4,4'-diaminothiobenzophenone {Thiomichler's Ketone (TK)}
An iodine ion concentration sensor, wherein the compound is one or more compounds selected from the group consisting of: The iodine ion concentration sensor according to claim 15, wherein the concentration of iodine ions is detected by applying UV-VIS-NIR spectroscopy while changing the wavelength of 250 nm to 900 nm. The iodine ion concentration sensor according to any one of claims 14 to 16, wherein the iodine ion concentration is detected in the presence of competing ions. The iodine removal filter using the mesoporous silica of any one of Claims 1-6.