JP5924656B2 - Mesoporous silica supporting lead ion adsorbing compound, lead ion sensor and lead recovery method using the same - Google Patents

Description

The present invention relates to mesoporous silica having a regular arrangement carrying a lead ion-adsorbing compound capable of selectively adsorbing lead ions as a target metal, and is supported on mesoporous silica. The present invention relates to a method for efficiently and selectively recovering lead ions contained in a metal solution containing lead ions using a lead ion adsorbing compound. Furthermore, it is related with the sensor which detects the lead ion concentration contained in the metal solution using the lead ion adsorption compound carry | supported by the mesoporous silica.

Lead is used in storage batteries used in automobiles and various machines, inorganic chemicals such as pigments and gasoline additives, electric wires and piping, etc. However, as known as lead poisoning, lead toxicity is a problem. . In Europe, the use of lead in electrical and electronic products is prohibited in principle by the Rose (RoHS) directive. Conventionally, tetraethyl lead has been added for the purpose of increasing the octane number of gasoline and protecting intake and exhaust valves and peripheral components. However, since lead is contained in the exhaust gas, it is a source of pollution. In developed countries, leaded gasoline is no longer used due to legal restrictions. In this way, the use of lead has been restricted, but lead is still used in bullets such as shotguns, and lead water pipes buried in the ground are still used and can be replaced. Not progressing. Furthermore, lead-acid batteries tend to increase production due to strong performance and strong demand for electric vehicles.

Considering the situation in which lead that harms human health must be used for the time being, it is necessary to prevent lead from entering the human body, and various studies have been conducted. For example, in order to reduce the well-known effects of heavy metals such as lead on human health and the environment, it is necessary to implement sufficient improvements and purification processes, especially in environmental science and environmental technology. (Non-Patent Documents 1 and 2) Many techniques have been proposed for methods and measuring means for removing toxic metals from drinking water and sewage, such as iron agglomeration, biological removal and adsorption using selective adsorbents I came. In various environments, most pollutants are present at concentrations well below the detection limits of commonly used processing methods. (Non-patent document 3) In the methods described in these documents, when there is a mixture of plural ions containing Pb (II) ions or an active metal other than lead, Pb (II) ions at a trace concentration level are measured. Cannot be extracted. Furthermore, there is a need for rapid, cost-effective, easy-to-use and reliable techniques for measuring and extracting trace amounts of Pb (II) ions.

In recent years, therefore, there has been an increasing global demand for developing photochemical sensor materials as accurate and rapid detection methods and measuring methods with good selectivity of contaminants. (Non-Patent Document 4) Among many detection techniques used to detect contaminants, the visual inspection method in particular is a simple technique that does not require complex equipment or a well-controlled environment. Although it is a useful method, no simple, quick and accurate method has been found for detecting lead ions.

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 metals adsorbed on mesoporous silica, particularly lead.

JP2007-327886A JP2007-327887A

A. P. F. Turner, Biosensors-sense and sensitivity. Science, 290 (2000) 1315-1317 P. Chen, C. He, Ageneral strategy to convert the merr family proteins into highly sensitive and selective fluorescent biosensors for metal ions.J. Am. Chem. Soc., 126 (2004) 728-729 A. Sayari, S. Hamoudi, Y. Yang, Applications of Pore-Expanded Mesoporous Silica. 1. Removalof Heavy Metal Cations and Organic Pollutants from Wastewater. Chem. Mater., 17 (2005) 212-216 B. Lei, B. Li, H. Zhang, S. Lu, Z. Zheng, W. Li, Y. Wang, Mesostructured silica chemically doped with RuII as a superior optical oxygen sensor. Adv. Funct. Mater., 16 (2006 1883-1891 S. A. El-Safty, A. A. Ismail, H. Matsunaga, T. Hanaoka, F. Mizukami, Optical nanoscale pool-on-surfacedesign for control sensing recognition of multiple cations. Adv. Funct. Mater., 18 (2008) 1485-1500 S. A. El-Safty, T. Balaji, H. Matsunaga, T. Hanaoka, F. Mizukami, Optical sensors based on nanostructuredcage materials for the detection of toxic metal ions. Angew. Chem. Int. Ed. 45 (2006) 7202-7208 S. A. El-Safty, D. Prabhakaran, A. A. Ismail, H. Matsunaga, F. Mizukami, Nanosensor design packages: A smart and compact development for metal ions sensing responses.Adv. Funct. Mater., 17 (2007) 3731-3745

As explained above, lead is used in a wide range of fields, but it is highly toxic, as seen in lead poisoning, etc., and affects human health, so it should not be taken into the human body, animals and plants as much as possible. is necessary. For that purpose, it is necessary to know what level of lead is contained in solutions such as domestic water and wastewater. However, there are few lead concentration sensors that quickly and accurately measure a very small amount of lead on the order of ppb, and there is a problem that even if there are, it cannot be used repeatedly. In addition, since there are few sensors that selectively detect lead, a solution containing a plurality of metal ions is affected by a metal other than lead and cannot accurately measure the lead concentration. Furthermore, when toxic lead is present in a solution such as domestic water or wastewater, it is necessary to remove the lead, but there are few methods for removing lead to the ppb order level. In addition, after removing lead with a recovery agent, there is a problem that it is difficult to effectively use the recovered lead because the means for separating the lead is difficult. There is also a problem that the cost for collecting and recycling lead in solutions such as domestic water and wastewater is high. Concerning the concentration detection of harmful lead in the environment, removal from the environment, and a method for recovering lead and recycling useful lead, a method that is simple, low in cost, good in selectivity, high in accuracy and high speed is required. Has been.

We recently developed a method for constructing chromogenic molecular probes on a wide range of cage-shaped mesostructures supported by materials having functional groups on the surface, a simple and reliable method that can detect a wide concentration range of metal ions, and a low Photochemical nanosensors that detect toxic metals at concentration levels have been proposed. (Non-Patent Documents 5, 6, and 7) The present invention has been developed as an extension technique thereof.
An object of the present invention is to support a lead ion adsorbed by supporting a compound capable of selectively adsorbing lead ions (hereinafter referred to as a lead ion adsorbing compound) on mesoporous silica having a highly ordered structure. The present invention provides an efficient method for adsorbing lead ions on an active compound and recovering the adsorbed lead, and mesoporous silica supporting a lead ion adsorbing compound used therefor. Furthermore, the present invention provides a lead ion sensor capable of accurately detecting a lead ion concentration and using a mesoporous silica supporting the lead ion adsorbing compound with a minute amount of ppb.

After mixing the silica source and the surfactant, an acidic aqueous solution is added and baked to produce mesoporous silica. This mesoporous silica carries a lead ion adsorbing compound (lead ions are not yet adsorbed). The lead ion adsorbing compound is a compound that can selectively adsorb lead ions {Pb (II)}. For example, a metal complex such as a chelate compound. (A compound that easily adsorbs a specific metal is referred to as a metal-adsorbing compound in this application. Here, the specific metal is used in the sense that the metal-adsorbing compound recovers a specific metal that can be selectively adsorbed. (In this invention, the target metal is lead.)

The mesoporous silica carrying (or modifying) the lead ion-adsorbing compound is brought into contact with a metal-dissolved solution in which various metals including lead are dissolved, and the target metal lead is added to the lead-ion adsorbing compound carried on the mesoporous silica. Adsorb. At this time, the target metal can be efficiently adsorbed by adjusting environmental factors such as the pH value, solution concentration, and solution temperature of the metal solution. (For example, a solution obtained by dissolving urban ore or the like in an acidic solution such as aqua regia to remove solid matter becomes a metal-dissolved solution in which various metals including lead as a target metal are dissolved.)

Next, the mesoporous silica supporting the lead ion adsorbing compound on which lead ions are adsorbed is brought into contact with a solution capable of liberating lead ions (lead ion free solution), and the adsorbed lead ions are dissolved in the lead ion free solution. Let The solution is filtered to separate it into a solid and a liquid. Since the separated liquid dissolves only lead ions, it is possible to recover lead as a target metal. By controlling the concentration, pH, reaction temperature, etc. of the solution, the lead recovery efficiency can be increased. The separated solid is mesoporous silica supporting a lead ion adsorbing compound, and the lead ion adsorbing compound supported on the mesoporous silica does not adsorb lead. That is, the solid material returns to mesoporous silica carrying a lead ion adsorbing compound (not adsorbing lead ions). In addition, since the main body (mesoporous silica supporting a lead ion adsorbing compound) has not changed, it can be used again as a lead ion adsorbent as a target metal.

In the present invention, since the lead 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), the reactive group of the lead ion adsorbing compound is used. Lead ions are easily and quickly adsorbed. Therefore, not only the adsorption response speed is high, but also the adsorption efficiency to the lead ion adsorbing compound is much higher than the adsorption efficiency to the single lead ion adsorbing compound, and the lead ion adsorption amount is also increased. In addition, since the lead ions adsorbed on the lead ion adsorbing compound are arranged in order and densely adsorbed, the adsorbed lead ions can be easily and quickly released. Therefore, the liberation efficiency of lead ions is very large. The lead ion adsorbing compound can selectively adsorb a large amount of lead ions by adjusting the pH value of the lead ion solution. Therefore, only lead can be recovered efficiently. Moreover, since a very small amount of lead ions on the order of ppb can be adsorbed and removed, the concentration of lead contained in a solution such as domestic water or waste water can be reduced to a very small level.

Further, the mesoporous silica supporting the lead ion adsorbing compound has a strong skeleton, and the skeleton of the mesoporous silica hardly changes even when the lead ion adsorbing compound is supported or lead ions are adsorbed. Since the adsorbed lead ions can be almost completely released, it returns to the original state (mesoporous silica supporting a lead ion adsorbing compound that does not adsorb lead ions), so the mesoporous silica supporting the lead ion adsorbing compound can be changed. Can be used repeatedly.
Accordingly, the total (total) lead recovery cost can be reduced. In addition, the mesoporous silica supporting the lead ion-adsorbing compound on which the lead ion of the present invention is adsorbed can detect a very low concentration of lead ions on the order of ppb using a colorimetric method or ultraviolet-visible spectroscopy. Therefore, it can be used as a lead ion concentration sensor.

It is a figure which shows the lead recovery system of this invention. FIG. 2 is a diagram showing a method for generating HOM-Cage. FIG. 3 shows a method for synthesizing receptor DTDR. FIG. 4 is a view showing a synthesis reaction of receptor DPAR. FIG. 5 is a view showing a synthesis reaction of receptor AMPC. FIG. 6 is a diagram showing a method for producing HOM-DPAR carrying receptor DPAR. FIG. 7 is a diagram showing a nitrogen adsorption / desorption isotherm of HOM-DPAR. FIG. 8 is a table showing the characteristics of HOM-DPAR determined from nitrogen adsorption / desorption isotherms. FIG. 9 is a diagram showing a nitrogen adsorption / desorption isotherm of HOM-DTDR. FIG. 10 is a table showing the characteristics of HOM-DTDR obtained from nitrogen adsorption / desorption isotherms. FIG. 11 is a diagram showing absorption spectral intensities (measured at room temperature) under various pH conditions of HOM-DPAR at a wavelength of 531 nm. FIG. 12 is a graph showing absorption spectral intensities (room temperature measurement) of HOM-DTDR under various pH conditions at a wavelength of 501 nm. FIG. 13 is a diagram showing the ultraviolet-visible spectrophotometric curve of HOM-DPAR-Pb (II) and the color tone of the solid material. FIG. 14 is a diagram showing the relationship between the absorbance of visible light having a wavelength of 531 nm and the lead {Pb (II)} ion concentration. FIG. 15 is a diagram showing the ultraviolet-visible spectrophotometric curve of HOM-DTDR-Pb (II) and the color tone of the solid material. FIG. 16 is a diagram showing the relationship between the absorbance in visible light having a wavelength of 501 nm and the lead {Pb (II)} ion concentration. FIG. 17 is a diagram showing the ultraviolet-visible spectrophotometric curve of HOM-AMPC-Pb (II) and the color tone of the solid material. FIG. 18 is a diagram showing the ultraviolet-visible spectrophotometric curve of HOM-DPAR-Pb (II) and the color tone of the solid material. FIG. 19 is a diagram showing an ultraviolet-visible spectrophotometric curve of a solid material and a color tone of the solid material after elution of Pb (II) ions with 0.05M HCl from HOM-DPAR-Pb (II). FIG. 20 is a table showing the content of each metal ion by ICP-OES of a solution containing a plurality of ions including lead {Pb (II)} ions before adding HOM-DPAR shown in Example 12. . FIG. 21 is a table showing the content of each metal ion by ICP-OES of the filtrate after addition of HOM-DTDR shown in Example 12. FIG. 22 is a table showing the content of each metal ion by ICP-OES in the filtrate after elution of Pb (II) ions adsorbed on HOM-DPAR with 0.05M HCl. FIG. 23 is a diagram showing the ultraviolet-visible spectrophotometric curve of HOM-DTDR {HOM-DTDR-Pb (II)} adsorbing lead ions and the color tone of the solid material. FIG. 24 is a diagram showing an ultraviolet-visible spectrophotometric curve of a solid material and a color tone of the solid material after elution of Pb (II) ions from HOM-DTDR-Pb (II) with 0.05M HCl. FIG. 25 is a table showing the content of each metal ion by ICP-OES of a solution containing a plurality of ions including lead {Pb (II)} ions before adding HOM-DTDR shown in Example 15. . FIG. 26 is a table showing the content of each metal ion by ICP-OES of the filtrate after addition of HOM-DTDR shown in Example 15. FIG. 27 is a table showing the content of each metal ion by ICP-OES in the filtrate after elution of Pb (II) ions adsorbed on HOM-DTDR with 0.05M HCl. FIG. 28 is a diagram showing the ultraviolet-visible spectrophotometric curve of HOM-AMPC-Pb (II) and the color tone of the solid material. FIG. 29 is a diagram showing an ultraviolet-visible spectrophotometric curve of a solid material and a color tone of the solid material after Pb (II) ions are eluted from 0.05 M HCl of this solid material, HOM-AMPC-Pb (II).

The present invention provides a lead ion detection technique and a lead recovery technique using various chelates having high selectivity and an 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 lead from waste containing active metals and noble metals.

The inner surface of mesoporous silica arranged at the nano level controls the environmental conditions such as pH to change the state of fixation / dissociation to make a lead ion detection sensor. Lead ions can be reliably adsorbed by bonding between adjacent atoms and surface atoms having different electron orbital structures and chelates. In addition, nano-level inner arrays increase charge transfer, so changes that are observable with the naked eye can occur even with very small amounts of lead adsorption at the ppb level.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a diagram showing a lead recovery system of the present invention. First of all, highly ordered mesoporous silica (HOM silica (HOMS): High Ordered Mesoporous Silica, usually referred to as HOM does not include silica, but in this specification HOM In this case, silica is also included unless otherwise specified.) Here, mesoporous silica is a kind of porous silica, called mesopore region, having pores (mesopores) having a substantially uniform and regular diameter in the range of 2 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.

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. When these structures are present in a wide range, a large amount of lead ion adsorbing compounds can be supported, and the total amount of lead ion adsorption can be increased. Moreover, the larger the BET specific surface area of HOM, the better, but it is usually 300 m ² / g or more, and preferably 400 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.

For example, silicon alkoxides such as TEOS (tetraethoxysilane), TMOS (tetramethoxysilane), tetramethylorthosilicate (C4H12O4Si), and tetraethylorthosilicate (C8H20O4Si) are used as the organic silicon compound. (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 = 0.75 gives a cubic structure Ia3d, mixing with a weight ratio of F108: TMOS = 0.7 Thus, a cubic structure Im3m cage silica structure is obtained.

FIG. 2 is a diagram showing a method for generating a cage-like or cylinder-like cubic monolith (hereinafter referred to as HOM-Cage). Place 8.0 g of Tetramethylorthosilicate (TMOS) in a round flask and add 5.6 g of surfactant (EO141PO44EO141) F108. The flask was kept in hot water at about 60 ° C. to completely dissolve the surfactant. Thereafter, 4 g of pH 1.3 acidic aqueous solution (H2O-HCl) was added and the solution was evaporated on a rotary evaporator for 10 minutes to form a solid material. Since this solid material contains water and is in the form of a mass, it is further kept in an oven at 40 ° C. for 1 day, and then further calcined at 450 ° C. for 8 hours to form powdered HOM-Cage (cage-like mesoporous silica).

Next, in the second stage, the lead ion adsorbing compound is supported on the HOM. At this stage, lead ions (and other metal ions) are not adsorbed to the lead ion adsorbing compound. (The term "lead ion adsorbing compound" is used as a term indicating that lead ions are not adsorbed. Examples of the lead ion adsorbing compound used in the present invention include metal complexes, inorganic metal compounds, and organic metal compounds such as cellulose, Also included are lead ion-adsorbing compounds such as proteins, etc. Metal complexes include inorganic and organic metal complexes, metal carbonyl compounds, metal clusters and organometallic compounds, and chelate compounds. A compound that can adsorb lead (ion) in metal, can be supported on HOM, and can release metal ions other than lead, which is the target metal, by chemical treatment, and then lead, which is the target metal, by other chemical treatment The lead ion-adsorbing compound is chemically bonded to HOM silica chemically through, for example, an OH group.

The lead ion-adsorptive compound is desirably a compound that selectively adsorbs a large amount of lead ions, which are target metals to be recovered. For example, the chelate compound which selectively couple | bonds with respect to lead ion is mentioned. By adjusting the pH value, temperature, concentration, and the like of a metal solution in which various metals including lead are dissolved, lead ions that are target metals can be selectively adsorbed to the lead ion adsorbing compound. In addition, the chelate compound can selectively adsorb a very small amount of lead (for example, on the order of ppb), so that even if the amount of lead ions contained in the metal solution is small, it can be efficiently and selectively used. Adsorbs lead ions.

For example, we have 4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol {4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol} (abbreviation DTDR) (Hereinafter also referred to as receptor DTDR), 2-dodecyl-4-((phenyl) diazenyl) resorcinol {2-dodecyl-4-((phenyl) diazenyl) resorcinol} (abbreviation DPAR) (hereinafter also referred to as receptor DPAR), or ammonium・ Methyl 2-mercaptophenylcarbamodithioate {ammonium methyl 2-mercaptophenylcarbamodithioate} (abbreviation AMPC) (hereinafter also referred to as receptor AMPC) chelate complexes selectively lead ions {Pb (II)} It was found to adsorb. In the present application, the lead ion adsorbing compound is also referred to as a receptor (DTDR, DPAR, AMPC). (Receptor is originally a biological term “receptor”, but in this application, the term “receptor” is sometimes used to mean a metal ion-adsorbing compound that adsorbs a specific metal (lead ion). )

As described later, when these receptors are immersed in a solution containing lead ions {Pb (II) ions} in which the solution is adjusted to a specific pH value, HOM silica carrying the receptor is immersed in the solution at other pH values. Pb (II) ions are selectively adsorbed in a larger amount than in the case of. As the adsorption amount of Pb (II) ions increases, the color of HOM silica carrying the receptor changes. Since the color tone and the adsorbed Pb (II) ion concentration are correlated, the Pb (II) ion concentration can be known from the color tone. That is, colorimetric analysis is possible. The meaning of selectively means that when HOM silica supporting these receptors is immersed in a solution containing lead ions {Pb (II) ions} and various other metal ions, only lead ions {Pb (II) ions} are absorbed. It means adsorbing and hardly adsorbing other various metal ions. That is, HOM silica carrying these receptors is extremely excellent in Pb (II) ion adsorption selectivity. One or more of these receptors may be supported on HOM silica. HOM silica having the characteristics of each receptor can be obtained.

Further, the Pb (II) ion concentration can also be measured from the light absorption spectrum after Pb (II) ion adsorption. That is, HOM silica carrying a receptor is also a Pb (II) ion concentration detection sensor. For example, mesoporous silica carrying these receptors (HOMS-DTDR, DPAR, AMPC) absorbs lead ions {Pb (II)} and has an absorption peak in visible light having a wavelength of 400 nm to 600 nm in UV-visible spectroscopy. Since there is a correlation between the absorptivity in this wavelength region and the lead ion concentration, HOMS-DTDR, DPAR, and AMPC adsorbing lead ions {Pb (II)} can be created by creating a calibration curve in advance. The lead ion concentration of this HOMS-DTDR, DPAR, and AMPC can be known from the absorptance data at the wavelength in the UV-Vis spectroscopy. Moreover, this HOMS-DTDR, DPAR, and AMPC selectively adsorb almost all lead ions in the solution and hardly adsorb other contained metal ions. Become. In particular, accurate concentrations can be detected even with trace amounts of lead at the ppb level.

There are various methods as a method (also referred to as a composite method) for supporting (modifying) such a lead ion adsorbing compound on the HOM. For example, when the lead 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 the lead ion adsorbing compound 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 an alcohol solution of an ionic lead ion adsorbing compound is contacted to adsorb the lead ion adsorbing compound in mesoporous silica, an organic solvent solution in which the mesoporous silica and the lead ion adsorbing compound are contacted, and an organic solvent Is removed by filtration or distillation, and the lead ion-adsorbing compound is physically adsorbed and supported in 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, the mesoporous silica A method of attaching an ionic functional group, bringing the anionic mesoporous silica and an aqueous solution of a cationic metal adsorbing compound into contact with each other, and adsorbing the lead ion adsorbing compound in the mesoporous silica. A method of fixing a lead ion-adsorbing compound in a pore and a surface by treating the inside of the pore and the surface with an organic solvent solution of a cationic organic reagent, a lead ion-adsorbing compound and a cation The organic solvent reagent of the obtained reagent complex is brought into contact with the silica, and the organic solvent solution is removed by filtration or distillation to carry the lead ion adsorbing compound in the silica. The method to be used is used.

In addition, in order to support the aforementioned receptors (DTDR, DPAR, AMPC) on the HOM, the receptor is dissolved in N, N-dimethylformamide (N, N-Dimethylformamide (DMF)) or ethanol, and this solution and the HOM are mixed. Contact to impregnate HOM with receptors (DTDR, DPAR, AMPC). In this way, HOM silica carrying the receptors (DTDR, DPAR, AMPC) in an orderly manner is completed. Evaporation of liquids such as ethanol and water (heating, vacuuming, etc.) and further drying to efficiently produce HOM silica supporting receptors (DTDR, DPAR, AMPC) in a high purity solid state (powder) it can.
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, a receptor (lead ion) -adsorbing compound is preferably adsorbed on HOM silica in which structures such as cubic structures Pm3n, Fm3m, Ia3d, and hexagonal structure P6m are formed in a wide range.

Naturally, the lead ion adsorbing compound alone can selectively adsorb lead ions as the target metal, but the lead ion adsorbing compound agglomerates and the like, so that a functional group capable of adsorbing lead ions cannot be used effectively. That is, even if lead ions, which are target metals, are adsorbed to the functional groups present on the surface of the aggregated (eg, particulate) lead ion adsorbing compound substance, the lead inside the lead ion adsorbing compound is diffused or permeated. Since the ion concentration decreases exponentially with respect to the distance (square), it is difficult for lead ions to be adsorbed to all the functional groups of the lead ion-adsorbing compound inside the particulate matter. In addition, even if lead ions are adsorbed to the functional group of the lead ion adsorbing compound inside the particulate matter, there is a problem that it is difficult to take out (free or back extract) the adsorbed lead ions. . It is possible to diffuse lead ions inside the particulate matter and take it out if a considerable amount of time is taken, but moving lead 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. Therefore, a mesoporous silica with a lead ion adsorbing compound supported on the surface and the inner wall of the pore is adsorbed with lead ions. Since the active compounds are arranged in order and bonded, the lead ion adsorption rate of the lead ion adsorbing compound becomes very high. That is, each molecule of the lead ion adsorbing compound can be used for lead ion adsorption. Since the lead ion solution and free (back extraction) solution easily and quickly penetrate the surface and pores of mesoporous silica, the lead ion adsorbing compound (reactive group) supported by the HOM In addition, contact quickly. This is quickly adsorbed when the lead ion adsorbing compound supported on the HOM comes into contact with the lead ion dissolving solution. Further, when the adsorbed lead ions are liberated, it means that the adsorbed lead ions are rapidly liberated if they come into contact with the liberated solution, so that 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 the chelate resin alone adsorbs lead ions, it cannot be controlled to which part of the chelate resin. In addition, lead ions are expected to be adsorbed (also referred to as extraction) to the chelate functional group in contact with the lead ion solution, but most of the lead ions are adsorbed inside the chelate resin that does not easily penetrate the lead ion solution. It is thought that it is not done. That is, the lead ion adsorption efficiency is very poor. Further, when the lead ions adsorbed on the chelate resin are released (also referred to as back extraction), it is difficult to take out the lead ions adsorbed inside the chelate resin.

Even when this chelate resin is repeatedly used, the efficiency of extraction and back-extraction of lead 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 lead ions or complex ions containing lead ions, the adsorption efficiency of lead ions becomes very high. In addition, the trapped lead ions or complex ions containing lead 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.

In the third stage, an acid solution or alkali solution (metal solution) in which various metals in city ore or natural ore are dissolved in advance or a waste solution (metal solution) in which various metals including lead ions are dissolved are prepared. deep. This metal dissolving solution is produced as follows, for example. When a material containing heavy metals such as Pb obtained from a mobile phone or personal computer is immersed in the aqueous solution, a large number of metals such as Pb, Fe, Cu, and Co (these are also included in city ores) are dissolved. . A solution obtained by removing solids from this solution is a metal dissolving solution. The metal dissolution solution and the HOM-MC are brought into contact with each other by immersing in a HOM (hereinafter referred to as HOM-MC) carrying a lead ion adsorbing compound (hereinafter referred to as MC) in the metal dissolution solution at a high density. By this contact, metal ions are adsorbed on the HOM-MC. (This is HOM-MC-Pb-M (Pb: lead (Pb) which is the target metal, and M: an adsorbed metal other than Pb).) The metal-adsorbing compound has a certain condition (pH value, temperature, The lead, which is the target metal, is selectively and preferentially adsorbed under the concentration, etc., so if the lead ion-adsorbing compound is immersed in the metal solution under the conditions, only the lead, the target metal, is adsorbed. HOM (ie, HOM-MC-Pb) can be obtained.

For example, HOM-MC can be brought into contact (including immersion) with a metal solution adjusted to a pH value that best adsorbs lead ions, and lead ions can be selectively adsorbed in large quantities on HOM-MC. However, some other metals M may be adsorbed due to slight fluctuations in conditions, etc., so by reducing the amount of metals other than lead, which is the target metal, in the metal solution beforehand, HOM-MC-Pb-M with very little metal M adsorption is obtained. For example, there is a method in which a metal other than lead is deposited and removed by adjusting pH in a metal solution or chemical treatment. In the case of the above-mentioned receptors (DTDR, DPAR), the metal dissolution solution is adjusted to pH = 11.5 to 13.0, preferably pH = 12.0 to 13.0, and in the case of receptor AMPC, the metal dissolution solution is adjusted to pH = 5.5 to 9.0. The lead {Pb (II)} ion can be efficiently adsorbed to HOM-MC (HOM-DTDR, DPAR, AMPC) by adjusting the pH to preferably 6.0 to 8.0. It should be noted that HOM silica adsorbed with lead ions can be efficiently collected in a high-purity solid state (powder) by evaporating liquids such as ethanol and moisture (heating, vacuuming, etc.) and further drying.

In the fourth stage, HOM-MC-Pb-M adsorbing a metal containing lead, which is the target metal, is immersed in a solution capable of releasing metals other than lead, which is the target metal, and other than lead, which is the target metal. The HOM-MC-Pb is formed by removing only the metal and adsorbing only the target metal lead. Alternatively, HOM-MC-Pb may be obtained by removing metals other than lead, which is the target metal, by adjusting conditions such as pH value, temperature, and solution concentration. If there is very little adsorption of metal other than lead, which is the target metal (in this case, HOM-MC-Pb from the beginning), or if there is a method that can release only lead, which is the target metal, the fourth The stage can be omitted. For example, in the case of HOM- (DTDR, DPAR, AMPC) carrying the above-mentioned receptors (DTDR, DPAR, AMPC), there is almost no M, that is, the state of HOM- (DTDR, DPAR, AMPC) -Pb Therefore, the fourth stage can be omitted.

In the fifth stage, HOM-MC-Pb, which has adsorbed only lead as the target metal, is immersed in a solution capable of dissolving lead as the target metal to dissolve lead ions as the target metal. In some cases, only lead ions, which are target metals, can be liberated by adjusting conditions such as pH value, temperature, and solution concentration. Or the lead ion which is a target metal can be melt | dissolved by immersing in the solution which can release | release only the lead ion which is a target metal. In such a case, it is not always necessary to use HOM-MC-Pb that adsorbs only the lead metal that is the target metal. Since HOM-MC from which lead ions, which are the target metal, are released 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- (DTDR, DPAR, AMPC) -Pb, Pb is almost completely eluted by being immersed in an HCl solution.

Further, when the target metal is separated from a solution of lead as the target metal by various methods (for example, electrolysis), the lead as the target metal can be recovered. That is, the target metal lead could be recovered from urban ore. For example, Pb (II) ions can be liberated by immersing HOM- (DTDR, DPAR, AMPC) -Pb in an aqueous hydrochloric acid solution. As a result, the solid HOM- (R1-R4) can be filtered and reused and can be used again in the third stage. Since Pb (II) ions are dissolved in the elution (elution) solution, they can be recovered as Pb alone by plating or the like. In addition, this process releases Pb from HOM-MC-Pb when HOM-MC adsorbs lead, which is the target metal, to form HOM-MC-Pb. Since it is HOM-MC, it can also be called a back extraction process.

Through the processes of the first stage to the fifth stage described above, a highly ordered material carrying a lead ion-adsorbing compound was obtained from a metal solution obtained by dissolving lead as a target metal obtained from urban ore. HOM silica (HOMS) can be used to recover the target metal lead.

<Generation of receptor DTDR [4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol {4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol}]>
FIG. 3 is a diagram showing a synthesis method relating to the generation of receptor DTDR. About 0.05 mol of 2-amino-1,3,4-thiadiazol is dissolved in 40 ml of HCl. The solution was cooled to 0 ° C. and 3.5 g NaNO ₂ dissolved in water was slowly added to the solution. The progress of the reaction was controlled by iodinated starch paper. Finally, the diazonium salt solution was slowly poured into a well-cooled solution of 3.4 g 6-dodecylresorcinol in 60 ml 4N HCl solution. The resulting solution was cooled at 0 ° C. for 30 minutes, after which an aqueous solution of 60 g sodium acetate in 180 ml water was added. This coupling reaction was carried out at 0 ° C. for 2 hours, and the produced precipitate was washed with water. This precipitate is DTDR.

<Production of Receptor DPAR [2-dodecyl-4-((phenyl) diazenyl) resorcinol {2-dodecyl-4-((phenyl) diazenyl) resorcinol}]>
FIG. 4 is a diagram showing a synthesis method relating to the generation of receptor DPAR. About 0.05 mol of aniline is dissolved in 40 ml of HCl. The solution was cooled to 0 ° C. and 3.5 g NaNO ₂ dissolved in water was slowly added to the solution. The progress of the reaction was controlled by iodinated starch paper. Finally, the diazonium salt solution was slowly poured into a well-cooled solution of 3.4 g 6-dodecylresorcinol in 60 ml 4N HCl solution. The resulting solution was cooled at 0 ° C. for 30 minutes, after which an aqueous solution of 60 g sodium acetate in 180 ml water was added. This coupling reaction was carried out at 0 ° C. for 2 hours, and the produced precipitate was washed with water. This precipitate is DPAR.

<Generation of receptor AMPC [ammonium methyl 2-mercaptophenylcarbamodithioate}]
FIG. 5 is a diagram showing a synthetic method relating to the production of receptor AMPC. 10 ml of 28% aqueous ammonia solution was added to 3 ml of 2-aminobenzenethiol in an ice bath with stirring for 10 minutes, and then 10 ml of second stream carbon was added dropwise within 30 minutes, and the mixture was stirred for 2 hours. did. Thereafter, it was filtered and washed with water to produce AMPC.

<Synthesis of HOM materials>
FIG. 2 is a diagram showing a method for generating a cage-like or cylinder-like cubic monolith (hereinafter referred to as HOM-Cage1). Place 8.0 g of tetramethylorthosilicate (TMOS) into a round flask and add 5.6 g of surfactant (EO141PO44EO141) F108. The flask was kept in hot water at about 60 ° C. to completely dissolve the surfactant. After this, 4 g of acidic aqueous solution with pH 1.3 (H2O-HCl) was added and the solution was evaporated on a rotary evaporator for 10 minutes to form a solid material. Since this solid material contained water and was agglomerated, it was further kept in an oven at 40 ° C. for 1 day and then calcined at 450 ° C. for 8 hours to form powdered HOM-Cage (cage-like mesoporous silica). (Hereinafter also referred to as HOM-Cage1.)

<Synthesis of HOM-sensor material (HOM-DPAR)>
HOM-sensor material, that is, HOM is loaded with receptors DPAR, DTDR and AMPC, and the methods for preparing HOM-DPAR, DTDR and AMPC are almost the same, so the method for synthesizing HOM-DPAR will be described below. FIG. 6 is a diagram showing a method for producing HOM-DPAR carrying receptor DPAR. 0.05 g of 2-dodecyl-4-((phenyl) diazenyl) resorcinol (DPAR) was placed in an ethanol solution in a round flask, and 1 g of HOM-Cage produced in Example 4 was added. The ethanol in the round flask was removed by connecting the flask to a rotary evaporator and slowly evacuating at 45-50 ° C. The viscous liquid in the flask changed to a colored gel material (solid product) within 2 hours. This material was dried at 65-70 ° C. for 5 hours, washed with warm water, and dried again at 65-70 ° C. The dried bulk powder was ground into a fine powder and this powdered material (HOM-DPAR) was used for lead ion {Pb (II)} extraction.

<Characteristics of HOM-sensor material (DPAR)>
FIG. 7 is a graph showing nitrogen (N ₂ ) adsorption / desorption isotherms of the HOM-sensor material (DPAR). The vertical axis represents the amount of adsorption, and the horizontal axis represents the relative pressure (P0 = 1 atm). The four samples {(1) HOM-Cage1, (2) HOM-DPAR, (3) HOM-DPAR-Pb (II), (4) HOM-DPAR (after Elution)} are IUPAC type IV curves. , Indicating the presence of mesoporous (pore diameter 2-50 nm). Also, the N ₂ adsorption / desorption isotherm of the four samples, the HOM monolith, shows a pronounced hysteresis loop with a well-known steep bend pattern of the adsorption / desorption branch. These are characteristics of the HOM sample, indicating that the cage pores (pores) are well formed and regularly arranged, and the sensor material DPAR is uniformly and regularly supported on the HOM. It shows that. Furthermore, the isotherm shape and capillary evaporation of P / P0 (0.5-0.55 range) are similar for all four samples.

FIG. 8 is a table showing the characteristics of the HOM-sensor material (DPAR) determined from the nitrogen (N ₂ ) adsorption / desorption isotherm. The BET specific surface area (Surface area) of the above materials {(1) HOM-Cage1, (2) HOM-DPAR, (3) HOM-DPAR-Pb (II), (4) HOM-DPAR (after Elution)} They are 473.96 m ² g ⁻¹ , 347.01 m ² g ⁻¹ , 349.81 m ² g ⁻¹ , and 362.49 m ² g ⁻¹ , respectively. In addition, the total pore volume (Pore volume) of the above materials {(1) HOM-Cage1, (2) HOM-DPAR, (3) HOM-DPAR-Pb (II), (4) HOM-DPAR (after Elution)} ) Are 0.72 cm ³ g ⁻¹ , 0.41 cm ³ g ⁻¹ , 0.43 cm ³ g ⁻¹ , 0.47 cm ³ g ⁻¹ , respectively, and the pore sizes are 8.6 nm and 5.4 respectively. nm, 5.83 nm, and 6.29 nm. It can be seen that the BET specific surface area is large and the pore size is small, and HOM-DTDR has a good adsorption site. Furthermore, even if lead ions are adsorbed on HOM-DPAR and the lead ions are eluted, there is no significant difference in the nitrogen adsorption / desorption isotherm, indicating that HOM-DPAR can be repeatedly used for lead ion adsorption.

<Characteristics of HOM-sensor material (DTDR)>
FIG. 9 is a graph showing nitrogen (N ₂ ) adsorption / desorption isotherms of HOM-sensor material (DTDR). The vertical axis represents the amount of adsorption, and the horizontal axis represents the relative pressure (P0 = 1 atm). The four samples {(1) HOM-Cage1, (2) HOM-DTDR, (3) HOM-DTDR-Pb (II), (4) HOM-DTDR (after Elution)} are IUPAC type IV curves. , Indicating the presence of mesoporous (pore diameter 2-50 nm). Also, the N ₂ adsorption / desorption isotherm of the four samples, the HOM monolith, shows a pronounced hysteresis loop with a well-known steep bend pattern of the adsorption / desorption branch. These are characteristics of the HOM sample, indicating that the cage pores (pores) are well formed and regularly arranged, and the sensor material DTDR is uniformly and regularly supported on the HOM. It shows that. Furthermore, the isotherm shape and capillary evaporation of P / P0 (0.45-0.5 range) are similar for all four samples.

FIG. 10 is a table showing the characteristics of the HOM-sensor material (DTDR) obtained from the nitrogen (N ₂ ) adsorption / desorption isotherm. The material BET specific surface area of {HOM-Cage1, HOM-DTDR , HOM-DTDR-Pb (II), HOM-DTDR (after Elution)} (Surface area) , respectively, 473.96m ² g ^-1, 422.26m ² g ^-1, 430.03m ² g ^-1, which is 463.43m ² g ^-1. In addition, the total pore volume of the materials {HOM-Cage1, HOM-DTDR, HOM-DTDR-Pb (II), HOM-DTDR (after Elution)} is 0.72 cm ³ g ⁻¹ , respectively. 0.48 cm ³ g ⁻¹ , 0.51 cm ³ g ⁻¹ , 0.57 cm ³ g ⁻¹ , and the pore sizes are 8.6 nm, 4.63 nm, 4.99 nm, and 4.99 nm, respectively. It can be seen that the BET specific surface area is large and the pore size is small, and HOM-DTDR has a good adsorption site. Furthermore, even if lead ions are adsorbed on HOM-DTDR and the lead ions are eluted, there is no significant difference in the nitrogen adsorption / desorption isotherm, indicating that HOM-DTDR can be repeatedly used for lead ion adsorption.

<Investigation of pH for HOM-DTDR, HOM-DPAR, and HOM-AMPC>
Using 8 types of pH aqueous solutions (2.0, 3.5, 5.2, 7.0, 9.5, 11.0, 12.5 and 13.5), at which pH the lead {Pb (II)} ion is most adsorbed, each sensor HOM-DTDR, We investigated HOM-DPAR and HOM-AMPC. For pH 2.0 and pH 3.5, a pH adjusting solution of either 0.01 M sulfuric acid or 0.2 M KCl—HCl was used, and for pH 5.2, a pH solution of CH ₃ COOH—CH ₃ COONa was used. For PH 7.0, 9.5, 11.0, 12.5 and 13.5, 3-morpholinopropane sulfonic acid (MOPS), N-cyclohexyl-3-aminopropane sulfonic acid {N-cyclohexyl- 3-aminopropane sulfonic
acid (CAPS)}, 2- (cyclohexylamino) ethane sulfonic acid {2- (cyclohexylamino) ethane sulfonic acid (CHES)}, and KCl, and then pH adjustment using 0.2M NaOH Was done. 2 ppm of Pb (II) was added to 4 ml of each pH solution, and a required amount of water was added to make a 20 ml aqueous solution. Each sensor HOM-DTDR, DPAR, and AMPC was added to this aqueous solution, stirred for 25 minutes, and then filtered to obtain a solid material.

The absorption spectrum of this solid material was measured with an ultraviolet-visible spectrophotometer (UV-VIS-NIR Spectroscopy). FIG. 11 shows absorption spectral intensities (measured at room temperature) under various pH conditions for HOM-DPAR at a wavelength of 531 nm. The vertical axis shows the relative intensity (%) with respect to the signal intensity when pH = 12.5, and the horizontal axis plots the pH value. From this figure, it can be seen that pH = 12.5 shows the highest signal intensity, and that the sensor HOM-DPAR best adsorbs lead ions Pb (II) when the aqueous solution is kept at this pH value.

FIG. 12 shows absorption spectral intensities (measured at room temperature) under various pH conditions for HOM-DTDR at a wavelength of 501 nm. The vertical axis shows the relative intensity (%) with respect to the signal intensity when pH = 12.5, and the horizontal axis plots the pH value. From this figure, it can be seen that pH = 12.5 shows the highest signal intensity, and that the sensor HOM-DTDR best adsorbs the lead ions {Pb (II)} when the aqueous solution is kept at this pH value.

Moreover, regarding HOM-AMPC, the same figure as FIG. 11 and FIG. 12 can be created by measuring the absorption spectral intensity (room temperature measurement) of HOM-DPAR at various pH conditions at a wavelength of 411 nm. From this result, the highest response signal was found at pH 7.0 for HOM-AMPC. That is, pH = 7.0 shows the highest signal intensity, and when the aqueous solution is kept at this pH value, the sensor HOM-AMPC best adsorbs lead ions {Pb (II)}.

From the above, considering the variation in pH value, the pH value that most adsorbs the lead ion {Pb (II)} is between 11.5 and 13.0, preferably between 12.0 and 13.0 for HOM-DPAR and HOM-DTDR. Yes, for HOM-AMPC, the pH value that most adsorbs the lead ion {Pb (II)} is between 5.5 and 9.0, preferably between 6.0 and 8.0.

<Extraction of lead {Pb (II)} ions by HOM-DPAR at various lead {Pb (II)} ion concentrations>
Take 4ml of pH 12.5 solution that best adsorbs lead {Pb (II)} ions, add various concentrations (0.2ppb ~ 2ppm) of lead {Pb (II)} ions, then add predetermined amount of water To make a 20 ml aqueous solution. 20 mg of HOM-DPAR was added to this, and it stirred for 30 minutes, and filtered. The absorption spectrum by ultraviolet visible spectroscopy was measured for the obtained solid material using an ultraviolet visible spectrophotometer (UV-VIS-NIR spectrometer).

FIG. 13 is a diagram showing an ultraviolet-visible spectrophotometric curve of this solid material, that is, HOM-DPAR {HOM-DPAR-Pb (II)} adsorbing lead {Pb (II)} ions and the color tone of the solid material. The color of the obtained solid material is the color when lead {Pb (II)} ions are not adsorbed (0ppb sample is light brown, which is the color of HOM-DPAR). (II)} As the ion concentration increases, it gradually shifts to dark brown (2 ppm). Therefore, by looking at this color tone, the concentration of lead {Pb (II)} ions taken into the solid material can be known, and HOM-DPAR is used as a lead {Pb (II)} ion concentration sensor by colorimetry. Can be used.

In the graph of the spectral curve shown in FIG. 13, the horizontal axis indicates the measurement wavelength, and the vertical axis indicates the absorption rate. From the bottom of the spectrophotometric curve, the Pb (II) concentration is 0 ppb (curve 1), 0.2 ppb (curve 2), 0.5 ppb (curve 3), 1.0 ppb (curve 4), 5 ppb (curve 5), 50 ppb ( Curve 6), 100 ppb (curve 7), 500 ppb (curve 8), and 2 ppm (curve 9) are shown. As described above, the spectrophotometry has an absorptivity continuously increasing as the lead {Pb (II)} ion concentration increases at all measurement wavelengths (300 nm to 900 nm). In particular, the effect of lead {Pb (II)} ion adsorption appears in spectral data in visible light having a wavelength of 531 nm.

FIG. 14 is a diagram showing the relationship between the absorbance of visible light having a wavelength of 531 nm and the concentration of lead {Pb (II)} ions, obtained using the spectral curve shown in FIG. The horizontal axis represents lead {Pb (II)} ion concentration {micromol (μM)}, and the vertical axis represents relative intensity of absorbance. The absorbance when the Pb (II) concentration is 0 is A0, the absorbance at various Pb (II) concentrations is A, and the relative intensity of the absorbance is represented by (A-A0). Therefore, when A = A0, the relative intensity of absorbance is zero.

Also from FIG. 14 (at a wavelength of 531 nm), the absorption spectrum intensity increases as the lead {Pb (II)} ion concentration increases. By using this curve, the concentration of lead {Pb (II)} ions adsorbed on HOM-DPAR can be known. That is, HOM-DPAR is a good lead {Pb (II)} ion concentration sensor. In particular, in the case of lead {Pb (II)} ion concentration of 0.05μM or less, the relationship between the relative intensity of the absorptance and the lead {Pb (II)} ion concentration is linear, as can be seen from the inner graph. If the rate is known, the lead {Pb (II)} ion concentration can be obtained immediately. Therefore, FIG. 8 can be said to be a calibration curve of the HOM-DPAR lead {Pb (II)} ion concentration sensor.

The lead {Pb (II)} ion concentration sensor using this HOM-DPAR has a measurement time of about 2 minutes with an ultraviolet-visible spectrophotometer (UV-VIS-NIR spectrometer) and a detection limit of 4.3 × 10 ⁻⁸ mol / dm 3 The detection range is 0.0002 to 10.0 ppm, and the required amount of the sensor is about 1 g of Pb at 10 g. Since HOM-DPAR can be used repeatedly, it can also be used as a recovery agent for lead {Pb (II)}.

<Extraction of lead {Pb (II)} ions by HOM-DTDR at various lead {Pb (II)} ion concentrations>
Take 4ml of pH 12.5 solution that best adsorbs lead {Pb (II)} ions, add various concentrations (0.2ppb ~ 2ppm) of lead {Pb (II)} ions, then add predetermined amount of water To make a 20 ml aqueous solution. 20 mg of HOM-DTDR was added to this, and it stirred for 30 minutes, and filtered. The obtained solid material was measured for absorbance by UV-visible spectroscopy using an UV-VIS spectrophotometer (UV-VIS-NIR spectrometer).

FIG. 15 is a diagram showing an ultraviolet-visible spectrophotometric curve of this solid material, that is, HOM-DTDR {HOM-DTDR-Pb (II)} adsorbing lead {Pb (II)} ions and the color tone of the solid material. The color tone of the obtained solid material is the color when lead {Pb (II)} ions are not adsorbed (0ppb sample is light brown, which is the color of HOM-DTDR). (II)} As the ion concentration increases, it gradually increases and transitions to dark brown (2 ppm). Therefore, by looking at this color tone, the concentration of lead {Pb (II)} ions taken into the solid material can be known, and HOM-DTDR is a lead {Pb (II)} ion concentration sensor by colorimetric analysis. Can be used.

In the graph of the spectral curve shown in FIG. 15, the horizontal axis indicates the measurement wavelength, and the vertical axis indicates the absorption rate. From the bottom of the spectrophotometric curve, the Pb (II) concentration is 0 ppb (curve 1), 0.2 ppb (curve 2), 0.5 ppb (curve 3), 1.0 ppb (curve 4), 5 ppb (curve 5), 50 ppb ( Curve 6), 100 ppb (curve 7), 500 ppb (curve 8), and 2 ppm (curve 9) are shown. In this way, the spectrophotometric intensity increases continuously as the lead {Pb (II)} ion concentration increases at all measurement wavelengths (300 nm to 900 nm). In particular, the effect of lead {Pb (II)} ion adsorption appears in spectral data in visible light having a wavelength of 501 nm.

FIG. 16 is a diagram showing the relationship between the absorbance of visible light having a wavelength of 501 nm and the concentration of lead {Pb (II)} ions, obtained using the spectrophotometric curve shown in FIG. The horizontal axis represents lead {Pb (II)} ion concentration {micromol (μM)}, and the vertical axis represents relative intensity of absorbance. The absorbance when the Pb (II) concentration is 0 is A0, the absorbance at various Pb (II) concentrations is A, and the relative intensity of the absorbance is represented by (A-A0). Therefore, when A = A0, the relative intensity of absorbance is zero.

FIG. 16 also shows that the absorbance increases as the lead {Pb (II)} ion concentration increases (at a wavelength of 501 nm). Using this curve, the concentration of lead {Pb (II)} ions adsorbed on HOM-DTDR can be known. That is, HOM-DTDR is a good lead {Pb (II)} ion concentration sensor. In particular, in the case of a lead {Pb (II)} ion concentration of 0.05 μM or less, since the relationship between the relative intensity of the absorbance and the lead {Pb (II)} ion concentration is linear as can be seen from the inner graph, the absorbance is If it is known, the lead {Pb (II)} ion concentration can be obtained immediately. Therefore, FIG. 10 can be said to be a calibration curve of the HOM-DTDR lead {Pb (II)} ion concentration sensor.

The lead {Pb (II)} ion concentration sensor using this HOM-DTDR has a measurement time of about 2 minutes with an ultraviolet-visible spectrophotometer (UV-VIS-NIR spectrometer) and a detection limit of 3.0 × 10 ⁻⁸ mol / dm 3 The detection range is 0.0002 to 15.0 ppm, and the required amount of sensor is about 1 g of Pb with 10 g of sensor. Since HOM-DTDR can be used repeatedly, it can also be used as a good recovery agent for lead {Pb (II)}.

<Extraction of lead {Pb (II)} ions by HOM-AMPC at various lead {Pb (II)} ion concentrations>
Take 4ml of pH7.0 solution that best adsorbs lead {Pb (II)} ions, add various concentrations (500ppb ~ 10ppm) of lead {Pb (II)} ions, then add a certain amount of water A 20 ml aqueous solution was made. To this, 20 mg of HOM-AMPC was added, stirred for 30 minutes and filtered. The obtained solid material was measured for absorbance by UV-visible spectroscopy using an UV-VIS spectrophotometer (UV-VIS-NIR spectrometer).

FIG. 17 is a diagram showing an ultraviolet-visible spectrophotometric curve of this solid material, that is, HOM-AMPC {HOM-AMPC-Pb (II)} adsorbing lead {Pb (II)} ions and the color tone of the solid material. The color tone of the obtained solid material is the color when lead {Pb (II)} ions are not adsorbed (0ppb sample is white, which is the color of HOM-AMPC), and lead {Pb ( II)} As the ion concentration increases, it gradually becomes yellow and transitions to yellowish white (10 ppm). Therefore, by looking at this color tone, it is possible to know the concentration of lead {Pb (II)} ions incorporated into the solid material, and HOM-AMPC is a lead {Pb (II)} ion concentration sensor by colorimetric analysis. Can be used.

In the graph of the spectral curve shown in FIG. 17, the horizontal axis indicates the measurement wavelength, and the vertical axis indicates the absorbance. From the bottom of the spectrophotometric curve, the Pb (II) concentration is 0 ppb (curve 1), 500 ppb (curve 2), 1 ppm (curve 3), 2 ppm (curve 4), 5 ppm (curve 5), and 10 ppm (curve 6). ). As described above, the spectrophotometric absorbance continuously increases as the lead {Pb (II)} ion concentration increases at all measurement wavelengths (300 nm to 900 nm) excluding the curve 6. In particular, the effect of lead {Pb (II)} ion adsorption appears in spectral data in visible light having a wavelength of 411 nm.

In the relationship between the absorptivity of visible light having a wavelength of 411 nm and the concentration of lead {Pb (II)} ions obtained using the spectrophotometric curve shown in FIG. 17, the absorbance increases with the concentration of lead {Pb (II)} ions. It grows as you go. By using this relationship, it is possible to know the concentration of lead {Pb (II)} ions adsorbed on HOM-AMPC. That is, HOM-AMPC is a good lead {Pb (II)} ion concentration sensor.

<Extraction of lead ions from solutions containing various metals by DPAR>
Take a pH 12.5 solution that best adsorbs lead {Pb (II)} ions in a 4 ml beaker, add 4 ml of a 0.4 M mixed solution (sodium citrate, sodium thiosulfate, sodium tartrate) to the beaker. Metal ions and 2 ppm of Pb (II) were added, then the required amount of water was added to make a 20 ml aqueous solution. NaOH was added to this aqueous solution to adjust to pH 12.5. In the multiple mixture aqueous solution, the concentration of Pb (II) is 2 ppm, and other metal ions (Al ³⁺ , Co ²⁺ , Cr ³⁺ , Bi ³⁺ , Pd ²⁺ , Mn ²⁺ , Se ⁴⁺ , Li ⁺ , Fe ³⁺ , Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Mg ²⁺ , Sn ²⁺ , Ca ²⁺ , Cd ²⁺ , and Hg ²⁺ ) concentrations were 4 ppm, respectively. Thereafter, 20 mg of HOM-DPAR was added and stirred for 30 minutes. The aqueous solution was filtered to obtain a solid material, and the solid material was subjected to UV-VIS-NIR analysis. The metal ion concentration in the filtered solution was analyzed by ICP-OES (ICP emission spectroscopy). The filtered solution did not contain Pb (II) ions, and all metal ions other than Pb (II) ions were present. Pb (II) in the solid material was measured by UV-VIS-NIR spectrum.

FIG. 18 is a diagram showing an ultraviolet-visible spectrophotometric curve and a color tone of the solid material, that is, HOM-DPAR {HOM-DPAR-Pb (II)} adsorbing lead ions. Solutions containing lead ions (2ppm
HOM-DPAR soaked in a solution containing only Pb (II) {curve 2: 2 ppm Pb}, a solution containing 2 ppm Pb (II) and multiple ions {curve 3: 2-4 ppm {Pb + Ions},) has a peak at λ = 531 nm However, HOM-DPAR immersed in a solution containing no lead ions {curve 1: 0 ppb, curve 4: 2 ppm Ions} does not show a Pb (II) peak at λ = 531 nm. This shows that HOM-DPAR does not adsorb metal ions other than lead ions.

From the color tone shown in FIG. 18, the color tone of HOM-DPAR-Pb (II) obtained from a mixed solution containing a plurality of ions including lead {Pb (II)} ion is lead {Pb (II)}. The color tone of HOM-DPAR-Pb (II) obtained from a solution containing only ions is almost the same, and HOM-DPAR-Pb (II) obtained from a mixed solution containing multiple ions contains lead {Pb ( It is suggested that metals other than II)} are not included.

<Elution / extraction operation of Pb (II) ions adsorbed on HOM-DPAR with 0.05M HCl>
The solid material obtained by extracting Pb (II) from the multiple ion mixture shown in Example 12 was placed in a beaker containing 20 ml of an eluent (0.05M HCl) and stirred for 30 minutes. This solution was filtered and separated into a filtrate and a solid material. FIG. 19 shows the solid material after elution of Pb (II) ions with 0.05 M HCl from HOM-DPAR {HOM-DPAR-Pb (II)} adsorbing lead {Pb (II)} ions. It is a figure which shows the ultraviolet-visible spectrophotometric curve and the color tone of a solid material. For comparison, HOM-DPAR UV-visible spectrophotometric curve (curve 1) and color tone (0 ppm) before adsorbing lead {Pb (II)} ion, HOM- adsorbed lead {Pb (II)} ion The UV-visible spectrophotometric curve (curve 2) and color tone (2 ppm Pb) of DPAR {HOM-DPAR-Pb (II)} are listed together. The UV-visible spectrophotometric curve of the solid material after elution of Pb (II) ions with 0.05M HCl is curve 3, and the color tone is “Elution by 0.05M HCl”. Comparing these three UV-visible spectrophotometric curves, it can be seen that the absorbance increases when Pb (II) ions are adsorbed, but returns to the original state (HOM-DPAR) when treated with 0.05M HCl. In particular, it can be understood from the fact that the typical peak of Pb ^{2+ at} the wavelength of 531 nm changes. This shows that the Pb (II) ion of HOM-DPAR-Pb (II) was almost eluted and changed to HOM-DPAR by 0.05M HCl treatment, and Hb-DPAR was repeated to repeat Pb (II) ion. It can be used to adsorb.

From the color tone shown in FIG. 19, the color tone (0 ppm) of HOM-DPAR not containing lead {Pb (II)} ions is light tan, and HOM-DPAR-Pb containing lead {Pb (II)} ions. The color tone of (II) {2ppm Pb (II)} turns brown, but the color tone of HOM-DPAR (Elution by 0.05M HCl) after elution of lead {Pb (II)} ions is restored. . This also indicates that the Pb (II) ion of HOM-DPAR-Pb (II) was almost eluted and changed to HOM-DPAR by 0.05M HCl treatment.

FIG. 20 is a table showing the content of each metal ion by ICP-OES of a solution containing a plurality of ions including lead {Pb (II)} ions before adding HOM-DPAR shown in Example 12. . The unit is ppm. The content of lead {Pb (II)} ions (Pb ²⁺ ) was 2.3 ppm, and the content of other metal ions was 3.6 to 5.3 ppm. FIG. 21 is a table showing the content of each metal ion by ICP-OES of the filtrate after addition of HOM-DTDR shown in Example 12. The lead {Pb (II)} ion concentration of this filtrate is 0.021 ppm, and it can be seen that the filtrate contains almost no lead {Pb (II)} ions. That is, almost 100% (about 99.1%) of lead {Pb (II)} ions were adsorbed on HOM-DPAR. Metal ions other than lead {Pb (II)} are hardly adsorbed by HOM-DPAR. Therefore, it can be seen that the selectivity of HOM-DPAR lead {Pb (II)} ion adsorption is very high. FIG. 22 is a table showing the content of each metal ion by ICP-OES in the filtrate after elution of Pb (II) ions adsorbed on HOM-DPAR by 0.05M HCl. The filtrate contains 2.18 ppm of Pb (II) ions, but no other metal ions. This also shows that the metal ion adsorbed on HOM-DPAR is only Pb (II) ion. It can also be seen that 95% of the lead {Pb (II)} ions originally contained in the solution were recovered. Considering analysis errors, it can be said that the recovery rate is almost 100%. Moreover, since HOM-DPAR can remove very small amounts of Pb (II) ions in the order of ppb to ppm from the solution, the problem caused by Pb (II) can also be solved. For example, if a small amount of Pb (II) is contained in water for daily use, it affects human health, but the HOM-DPAR of the present invention removes a small amount of Pb (II) and does not affect health. Can be reduced. Furthermore, from the data based on the N ₂ adsorption / desorption isotherm, the characteristics of the solid material after filtration have almost the same characteristics as the original HOM-DPAR. Therefore, it was shown that HOM-DPAR-Pb (II) adsorbing Pb (II) ions returned to HOM-DPAR, and it was found that HOM-DPAR can be repeatedly used for lead ion adsorption.

<Removal and selectivity of lead from active metal mixed solution containing various metals by DTDR>
Take 4 ml of pH 12.5 solution that best adsorbs lead {Pb (II)} ion in a beaker, add 4 ml of 0.3M mixed solution (sodium citrate, sodium thiosulfate, sodium tartrate) to the beaker, and Various metal ions and 2 ppm of Pb (II) were added, then the required amount of water was added to make a 20 ml aqueous solution. NaOH was added to this aqueous solution to adjust to pH 12.5. In the multiple mixture aqueous solution, the concentration of Pb (II) is 2 ppm, and other metal ions (Al ³⁺ , Co ²⁺ , Cr ³⁺ , Bi ³⁺ , Pd ²⁺ , Mn ²⁺ , Se ⁴⁺ , Li ⁺ , Fe ³⁺ , Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Mg ²⁺ , Sn ²⁺ , Ca ²⁺ , Cd ²⁺ , and Hg ²⁺ ) concentrations were 4 ppm, respectively. Thereafter, 20 mg of HOM-DTDR was added and stirred for 30 minutes. The aqueous solution was filtered to obtain a solid material, and the solid material was subjected to UV-VIS-NIR analysis. The metal ion concentration in the filtered solution was analyzed by ICP-OES (ICP emission spectroscopy). The filtered solution did not contain Pb (II) ions, and all metal ions other than Pb (II) ions were present. Pb (II) in the solid material was measured by UV-VIS-NIR spectrum.

FIG. 23 is a diagram showing the ultraviolet-visible spectrophotometric curve of this solid material, that is, HOM-DTDR {HOM-DTDR-Pb (II)} adsorbing lead ions and the color tone of the solid material. HOM-DTDR immersed in a solution containing lead ions (solution containing only 2 ppm Pb (II) {curve 2: 2 ppmPb}, solution containing 2 ppm Pb (II) and multiple ions {curve 3: 2-4 ppm {Pb + Ions}) Shows a peak at λ = 501 nm, but it does not show a Pb (II) peak at λ = 501 nm when immersed in a solution containing no lead ions {curve 1: 0 ppb, curve 4: 2 ppm each Ions}. This shows that HOM-DTDR does not adsorb metal ions other than lead ions.

From the color tone shown in FIG. 23, the color tone of HOM-DTDR-Pb (II) obtained from a mixed solution containing a plurality of ions including lead {Pb (II)} ions is lead {Pb (II)}. The color tone of HOM-DTDR-Pb (II) obtained from a solution containing only ions is almost the same, and HOM-DTDR-Pb (II) obtained from a mixed solution containing multiple ions contains lead {Pb ( It is suggested that metals other than II)} are not included.

<Elution / extraction operation of Pb (II) ions adsorbed on HOM-DTDR with 0.05M HCl>
The solid material obtained by extracting Pb (II) from the multiple ion mixture shown in Example 14 was placed in a beaker containing 20 ml of an eluent (0.05M HCl) and stirred for 30 minutes. This solution was filtered and separated into a filtrate and a solid material. FIG. 24 shows the solid material after the Pb (II) ions were eluted with 0.05M HCl from this solid material, that is, HOM-DTDR {HOM-DTDR-Pb (II)} adsorbing lead {Pb (II)} ions. It is a figure which shows the ultraviolet-visible spectrophotometric curve and the color tone of a solid material. For comparison, HOM-DTDR UV-visible spectrophotometric curve (curve 1) and color tone (0 ppm) before adsorbing lead {Pb (II)} ion, HOM- adsorbed lead {Pb (II)} ion The UV-visible spectrophotometric curve (curve 2) and color tone {2 ppm Pb (II)} of DTDR {HOM-DTDR-Pb (II)} are listed together. The UV-visible spectrophotometric curve of the solid material after eluting Pb (II) ions with 0.05M HCl is curve 3, and the color tone is (Elution by 0.05M HCl). Comparing these three UV-visible spectrophotometric curves, it can be seen that when Pb (II) ions are adsorbed, the absorbance increases, but when 0.05M HCl treatment is performed, the original state (HOM-DTDR) is restored. In particular, it can be understood from the fact that the typical peak of Pb ^{2+ at} the wavelength of 501 nm changes. This indicates that the Pb (II) ion of HOM-DTDR-Pb (II) was almost eluted and changed to HOM-DTDR by 0.05M HCl treatment, and Hb-DTDR was repeated repeatedly for Pb (II) ion. It can be used to adsorb.

From the color tone shown in FIG. 24, the color tone (0 ppm) of HOM-DTDR not containing lead {Pb (II)} ions is light tan, and HOM-DTDR-Pb containing lead {Pb (II)} ions. The color tone of (II) {2ppm Pb (II)} turns brown, but the color tone of HOM-DTDR (Elution by 0.05MHCl) after elution of lead {Pb (II)} ions is restored. . This also indicates that the Pb (II) ion of HOM-DTDR-Pb (II) was almost eluted and changed to HOM-DTDR by 0.05M HCl treatment.

FIG. 25 is a table showing the content of each metal ion by ICP-OES of a solution containing a plurality of ions including lead {Pb (II)} ions before adding HOM-DTDR shown in Example 15. . The unit is ppm. The content of lead {Pb (II)} ions (Pb ²⁺ ) was 2.2 ppm, and the content of other metal ions was 3.6 to 5.3 ppm. FIG. 26 is a table showing the content of each metal ion by ICP-OES of the filtrate after addition of HOM-DTDR shown in Example 15. The lead {Pb (II)} ion concentration of this filtrate is 0.031 ppm, and it can be seen that the filtrate contains almost no lead {Pb (II)} ions. That is, almost 100% (about 98.6%) of lead {Pb (II)} ions were adsorbed on the HOM-DTDR. Metal ions other than lead {Pb (II)} are hardly adsorbed by HOM-DTDR. Therefore, it can be seen that the selectivity of the adsorptivity of lead {Pb (II)} ions in HOM-DTDR is very high. FIG. 27 is a table showing the content of each metal ion by ICP-OES in the filtrate after elution of Pb (II) ions adsorbed on HOM-DTDR with 0.05M HCl. The filtrate contains 2.11 ppm of Pb (II) ions, but no other metal ions. This also shows that the metal ion adsorbed on HOM-DTDR is only Pb (II) ion. It can also be seen that 96% of the lead {Pb (II)} ions originally contained in the solution were recovered. Considering analysis errors, it can be said that the recovery rate is almost 100%. Moreover, since HOM-DTDR can remove very small amounts of Pb (II) ions in the order of ppb to ppm from the solution, various problems caused by Pb (II) can be solved. For example, if a small amount of Pb (II) is contained in water for daily use, it affects human health, but the HOM-DPAR of the present invention removes a small amount of Pb (II) and does not affect health. Can be reduced. Furthermore, from the data based on the N ₂ adsorption / desorption isotherm, the characteristics of the solid material after filtration have almost the same characteristics as the original HOM-DPAR. Therefore, it was shown that HOM-DTDR-Pb (II) adsorbing Pb (II) ions returned to HOM-DTDR, and it was found that HOM-DTDR can be repeatedly used for lead ion adsorption.

<Removal and selectivity of lead from active metal mixed solution containing various metals by AMPC>
Take 4 ml of a pH 7.0 solution that best adsorbs lead {Pb (II)} ions in a beaker, add 4 ml of a 1.0 M solution (sodium citrate, sodium tartrate) to the beaker, and add various metal ions and 2 ppm of Pb (II) was added and then the required amount of water was added to make a 20 ml aqueous solution. In this multiple mixture aqueous solution, the concentration of Pb (II) is 2 ppm, and other metal ions (Al ³⁺ , Co ²⁺ , Cr ³⁺ , Bi ³⁺ , Mn ²⁺ , Se ⁴⁺ , Li ⁺ , Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Mg ²⁺ , Sn ²⁺ , Ca ²⁺ , Cd ²⁺ , Hg ²⁺ ) concentrations were 4 ppm each. Thereafter, 20 mg of HOM-AMPC was added and stirred for 30 minutes. The aqueous solution was filtered to obtain a solid material, and the solid material was subjected to UV-VIS-NIR analysis. The metal ion concentration in the filtered solution was analyzed by ICP-OES (ICP emission spectroscopy). The filtered solution did not contain Pb (II) ions, and all metal ions other than Pb (II) ions were present. Pb (II) in the solid material was investigated by UV-VIS-NIR spectrum.

FIG. 28 is a diagram showing the UV-visible spectrophotometric curve of this solid material, that is, HOM-AMPC adsorbing lead ions, and the color tone of the solid material. HOM- dipped in a solution containing lead ions (solution containing only 2 ppm Pb (II) {curve 2: 2 ppmPb}, solution containing 2 ppm Pb (II) and multiple ions {curve 3: 2-4 ppm {Pb + Ions},) DTDR shows a peak at λ = 411 nm, but it does not show a Pb (II) peak at λ = 501 nm when immersed in a solution {curve 1: 0 ppb,} not containing lead ions. This shows that HOM-AMPC does not adsorb metal ions other than lead ions.

From the color tone shown in FIG. 28, the color tone of HOM-DTDR-Pb (II) obtained from the mixed solution containing a plurality of ions including lead {Pb (II)} ion is lead {Pb (II)}. The color tone of HOM-DTDR-Pb (II) obtained from a solution containing only ions is similar to that of HOM-DTDR-Pb (II), and HOM-DTDR-Pb (II) obtained from a mixed solution containing multiple ions contains lead {Pb ( It is suggested that metals other than II)} are not included.

<Elution / extraction procedure of Pb (II) ions adsorbed on HOM-AMPC with 0.05M HCl>
The solid material obtained by extracting Pb (II) from the multiple ion mixture shown in Example 16 was placed in a beaker containing 20 ml of an eluent (0.05M HCl) and stirred for 30 minutes. This solution was filtered and separated into a filtrate and a solid material. FIG. 29 shows the solid material after the Pb (II) ions were eluted with 0.05M HCl from this solid material, that is, HOM-AMPC {HOM-AMPC-Pb (II)} adsorbing lead {Pb (II)} ions. It is a figure which shows the ultraviolet-visible spectrophotometric curve and the color tone of a solid material. For comparison, HOM-AMPC UV-visible spectrophotometric curve (curve 1) and color tone (0 ppb) before adsorbing lead {Pb (II)} ion, HOM- adsorbed lead {Pb (II)} ion AMPC {HOM-AMPC-Pb (II)} UV-visible spectrophotometric curve (curve 2) and color tone {2 ppm Pb} are listed together. The UV-visible spectrophotometric curve of the solid material after elution of Pb (II) ions with 0.05M HCl is curve 3 and the color tone is (After elution by 0.05M HCl). Comparing these three UV-visible spectrophotometric curves, it can be seen that the absorbance increases when Pb (II) ions are adsorbed, but returns to the original state (HOM-AMPC) when treated with 0.05M HCl. In particular, it can be understood from the fact that the typical peak of Pb ^{2+ at} the wavelength of 411 nm changes. This indicates that the Pb (II) ion of HOM-AMPC-Pb (II) was almost eluted and changed to HOM-AMPC by 0.05M HCl treatment, and Hb-AMPC was repeated to form Pb (II) ion. It can be used to adsorb.

From the color tone shown in FIG. 29, the color tone (0 ppm) of HOM-AMPC not containing lead {Pb (II)} ions is white and HOM-AMPC-Pb (II) containing lead {Pb (II)} ions. ) Color tone {2ppm Pb (II)} turns pale yellowish white, but HOM-AMPC color tone (After elution by 0.05MHCl) after elution of lead {Pb (II)} ions may return I understand. This also indicates that the Pb (II) ion of HOM-AMPC-Pb (II) was almost eluted and changed to HOM-AMPC (returned to the original) by 0.05M HCl treatment.

As described above, the present invention provides a lead ion such as a chelate compound that selectively adsorbs the target metal lead {Pb (II)} ion to highly ordered mesoporous silica prepared from an organosilicon compound and a surfactant. An adsorbent compound was supported, and the mesoporous silica supporting the lead ion adsorbent compound was brought into contact with a solution in which the target metal lead ion was dissolved, and the target metal lead ion was selectively supported on the mesoporous silica. Adsorbed to lead ion adsorbing compounds. Thereafter, the mesoporous silica supporting the lead ion adsorbing compound that adsorbs the target metal lead ion is chemically treated to release the target metal lead ion from the lead ion adsorbing compound supported on the mesoporous silica, Collect the target metal lead. The mesoporous silica supporting a lead ion adsorbing compound from which lead ions as target metals are liberated can be reused. The mesoporous silica supporting the lead ion adsorbing compound can also be used as a lead (ion) concentration detection sensor.

The present invention provides a material and method for efficiently and inexpensively extracting lead contained in urban ore and the like, as well as a lead ion sensor. As can be seen from the above description, not only urban ore but also various metals are provided. Extraction, adsorption and reverse extraction of lead ions from ordinary ores containing iron, and extraction, adsorption and reverse extraction of lead from solutions containing lead ions, for example, waste liquid discharged from processes such as plating and metallurgical processes Extract to recover lead. Further, it is possible to inspect whether harmful lead is dissolved in domestic water, waste liquid, etc., and it is possible to detect even a minute concentration of the order of ppb to ppm. Furthermore, the lead concentration can be reduced to a very small concentration by adsorbing lead dissolved in domestic water or waste liquid. Therefore, it can also be used as a lead removal filter. For example, it has been pointed out that mixing of lead into tap water from lead water pipes used as water pipes affects the human body. When used in water filters, lead can be reduced to very low levels. In particular, HOM-AMPC that adsorbs lead ions best around pH = 7.0 is optimal.
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.

INDUSTRIAL APPLICABILITY The present invention can be used in the industrial field related to lead sensors, the industrial field for removing lead from substances and materials containing various metals, and the industrial field for recovering lead.

Claims (10)

Lead ion-adsorbing compound that adsorbs lead ions and can release the adsorbed lead ions from a solution in which various metals including lead ions , which are the target metal, are dissolved (metal solution). Mesoporous silica carrying
The lead ion adsorbing compound is:
4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol {4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol} (DTDR),
2-dodecyl-4-((phenyl) diazenyl) resorcinol {2-dodecyl-4-((phenyl) diazenyl) resorcinol} (DPAR), or ammonium methyl 2-mercaptophenylcarbamodithioate {ammonium methyl 2-mercaptophenylcarbamodithioate} (AMPC)
Mesoporous silica, which is one or more compounds selected from the group consisting of 2. The mesoporous silica according to claim 1, wherein a pH value of the metal solution is a pH value at which lead ions as a target metal are adsorbed to the maximum. The DTDR and the pH value when the DPAR is 11.5 to 13.0, wherein the pH value when the AMPC is characterized in that it is a 5.5 to 9.0, mesoporous silica of claim 2. The lead removal filter using the mesoporous silica in any one of Claims 1-3. A step of supporting a lead ion adsorbing compound on mesoporous silica;
A mesoporous silica carrying a lead ion-adsorbing compound is brought into contact with a metal solution containing lead ions, which is a target metal, adjusted to a pH value that best adsorbs the target metal lead ions, and the lead ion-adsorbing compound is brought into contact with the lead ion-adsorbing compound. A process of selectively adsorbing lead ions as a target metal;
A lead recovery method comprising: liberating lead ions as target metals from the lead ion-adsorbing compound that adsorbs lead ions as target metals,
The lead ion adsorbing compound is:
4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol {4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol} (DTDR),
2-dodecyl-4-((phenyl) diazenyl) resorcinol {2-dodecyl-4-((phenyl) diazenyl) resorcinol} (DPAR), or ammonium methyl 2-mercaptophenylcarbamodithioate {ammonium methyl 2-mercaptophenylcarbamodithioate} (AMPC)
One or more compounds selected from:
Lead recovery method. The lead recovery method according to claim 5, wherein the mesoporous silica supporting the lead ion adsorbing compound is reused. Wherein the pH value in the case of DTDR and DPAR are 11.5 to 13.0, the pH value when the AMPC is characterized in that a 5.5 to 9.0, lead recovery method according to claim 5 or 6 . 4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol {4- (2-diazenyl-1,3,4-thiadiazole) -6-dodecylresorcinol} (DTDR), 2-dodecyl-4 -((Phenyl) diazenyl) resorcinol {2-dodecyl-4-((phenyl) diazenyl) resorcinol} (DPAR) or ammonium methyl 2-mercaptophenylcarbamodithioate} ( A lead ion detection sensor using mesoporous silica supporting at least one selected from AMPC). The lead ion detection sensor according to claim 8, wherein the lead ion concentration is detected by a colorimetric method or ultraviolet-visible spectroscopy. The lead ion detection sensor according to claim 9, wherein the lead ion concentration by ultraviolet visible spectroscopy is detected using a wavelength of 400 nm to 600 nm.