JP2006263509A - Method for fixing substance easily eluted in water, and material obtained by it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique of changing a substance contained in an object to be treated from an easily eluting state to a hardly eluting state. <P>SOLUTION: The fixing method and recycling method of a substance which is easily eluted in water are characterized in that the weathered object of precipitating volcanic products is mixed in the object to be treated containing the substance which is easily eluted in the water and a hardly eluting chemical complex is formed by the bonding of the substance which is easily eluted in water and the weathered object of the precipitating volcanic product in the mixture, and the chemical complex is obtained by the recycling method. In the method of this invention, a treatment cost is low, treatment work is simple, throughput is high and fixation capacity is excellent. Additionally, different chemical complexes can be formed by acting on the plurality of substances simultaneously. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention adds a reactive substance to incinerated ash, combustion ash, sludge, soil, waste, waste water, waste liquid, etc. that contains a plurality of harmful substances that are easily eluted in water. The present invention relates to a method for immobilizing a substance, and a material that can be used for a specific application.

  It is known that incineration ash, combustion ash, sludge, soil, waste, etc., and wastewater and waste liquid derived from them contain harmful substances that are easily eluted into water and give a load to the environment. Therefore, they cannot be discharged into the environment as they are, and they are either buried in a treatment plant with special measures to prevent the released harmful substances from being released into the environment, or harmful substances that are likely to be dissolved in water are difficult to dissolve. In other words, fixing is performed. Conventionally used immobilization treatments include a solidification method, a chemical insolubilization method, an electrolysis method, a cleaning method, and a heat treatment method.

  In the solidification method, the material to be treated is mixed with cement or a solidified material, and a water-impervious layer is formed on the surface and further inside thereof, and the short-term diffusion of substances that easily elute into water is suppressed by the formed water-impervious layer. It is a method to do. This method is widely used because of its low processing cost and large processing capacity. However, in long-term storage, it re-elutes toxic substances that have become immobilized due to deterioration of the water shielding layer due to pH changes due to acid rain, etc. Has the disadvantage of low stability.

  The chemical insolubilization method is a method of using various chemical substances to change a harmful substance that is easily eluted in water into a hardly soluble substance. When the method is applied to an aqueous system, it is also possible to form a hardly soluble salt and precipitate and remove harmful substances that are easily eluted in water. The chemical substances used depend on the harmful substances to be immobilized.For example, cadmium and lead are hydroxides, chromium is sulfite, arsenic and selenium are iron or aluminum salts, and cyanide is hypochlorous acid. Sodium chlorate is generally used, and calcium or aluminum salts are generally used for boron and fluorine. This chemical insolubilization method is frequently used because the processing cost is relatively low, but there is a possibility that re-elution may occur due to decomposition of a hardly soluble salt due to pH change or the like. In addition, if the material to be treated contains multiple hazardous substances that are likely to be eluted in water, it is necessary to use multiple chemical substances corresponding to the hazardous substances to be immobilized, resulting in increased processing costs and complicated processing operations. Invite.

  To remove harmful substances that easily elute in water, electrolysis that recovers metal ions by electrolysis, cleaning that removes high-concentration fine particles by washing and classification, and recovery of volatile components by heating Heat treatment methods are also used, and the target substance can be removed up to about 50% by these methods. However, further removal is difficult and a large amount of residual material is generated, and there are also problems such as long processing time and high processing cost. There is a similar problem in the combined treatment of pumped water extraction and ultra-high pressure cleaning that is performed when contaminated soil is treated in situ, and in-situ treatment of contaminated soil is aimed at improving the environment in the short to medium term. As a matter of course, the contaminated soil is covered with sand, but this is a “lid on odor” method, and the contaminated soil remains as it is.

  Incidentally, allophane, which is basic aluminum silicate, is a porous material having a large number of fine pores having a diameter of about 0.3 to 0.5 nm. Allophane is used for physical adsorption and aggregation of various substances by utilizing this porous property. For example, a purification material obtained by adding calcium hydroxide to allophane at a predetermined blending ratio is known. (For example, see Patent Document 1 and Patent Document 2). In this purification material, a sticky aluminum hydroxide and calcium sulfate film synthesized from allophane and calcium hydroxide encloses impurities in wastewater, and allophane promotes precipitation to separate harmful target substances. .

  Further, a volcanic ash adsorbent having a chemical composition of 18 to 24% silicon, 23 to 29% aluminum, and 1 to 5% iron and obtained by granulating volcanic ash soil mainly composed of allophane is also known ( For example, see Patent Document 3). This is a spherical granulated product having a bulk specific gravity of 0.5 to 0.7 and an underwater destruction rate of 25% or less, and can adsorb and remove phosphinic acid ions and phosphonic acid ions.

  Furthermore, a waste treatment material containing a reducing metal and at least one selected from the group consisting of a reducing agent, aluminum sulfate, allophane and bentonite (see, for example, Patent Document 4), and pregelatinized starch or dextrin In addition, a harmless stabilizing treatment agent containing sodium silicate or hydrogen phosphate compound and allophane (for example, see Patent Document 5) is also known. Here, allophane acts as a physical adsorbent in the former and as an agglomerate of reaction products produced by the other two components in the latter.

It is also known to remove boron and fluorine in water using allophane (see, for example, Patent Document 6 and Patent Document 7). In this removal method, alumina, allophane, or a magnesium compound is alternatively used as a component that can remove fluorine ions or boron ions present in water, and it is also necessary to adjust the pH of the water to be treated during treatment.
JP-A-5-137905 JP-A-5-168817 JP-A-6-154594 Japanese Patent Laid-Open No. 7-60221 JP-A-7-136615 JP 2004-283760 A JP 2002-263640 A

  Coal ash which is a kind of incinerated ash is mentioned as a to-be-processed object which contains the harmful substance which is easy to elute in water and needs to fix | immobilize this substance. The amount of coal ash is expected to continue to increase in the future as energy consumption increases. Because of the large amount of generation, the coal ash is harmful because it is easy to elute into water contained by a method with low processing costs and high processing capacity. It is desired to immobilize the material. However, the method satisfying these two conditions in the prior art has a poor immobilization ability and cannot be put to practical use. The coal ash also contains a plurality of harmful substances to be immobilized, such as boron, fluorine, arsenic, selenium, etc., which has led to an increase in processing costs and complicated processing operations. For these reasons, only a portion of coal ash with a low content of hazardous substances has been treated, and those with a high content cannot be treated sufficiently with the prior art, and are unfilled without treatment. It was. However, the remaining capacity of landfills is limited to the increasing amount of coal ash, and it is difficult to develop new landfills. There was an urgent need to develop a new immobilization method that could be applied.

  Therefore, an object of the present invention is a method of immobilizing harmful substances that are easily eluted in water contained in the object to be treated, and is a method that is inexpensive and easy to treat, and has a high immobilization ability. It is to provide.

  As a result of intensive studies, the present inventors have found that weathered products of descending volcanic products are combined with harmful substances that are easily eluted in water to form a hardly-eluting chemical complex. And in this treatment, weathered materials of descending volcanic ejecta can be procured at low cost, can easily cope with an increase in the number of objects to be treated, has sufficient immobilization ability, and is easily eluted into a plurality of waters. The present invention was completed with the knowledge that it can act simultaneously and in multiple ways against harmful substances.

  Furthermore, the present inventor has found that the addition of a weathering product of a descending volcanic eruption does not significantly affect the physical properties (specific gravity, volume, hardness, appearance, strength, etc.) of the object to be treated before the addition. It was. Moreover, by controlling the amount of weathering in the descending volcanic ejecta, substances that easily elute in water that forms a difficult-to-elute chemical complex with the weathering in the descending volcanic ejecta can be released slowly. It has also been discovered that the chemical complex can be reused for a variety of specific applications where it is effective that trace amounts of substances that are easily eluted in the water are present.

  The present invention is based on the new knowledge that weathering substances of descending volcanic ejecta form various chemical complexes with harmful substances that easily elute in water, and further research on the structure and composition of the chemical complexes. It has been done. Accordingly, even if the weathered product of the descending volcanic ejecta contains allophane as one component, the present invention characterized in that the weathered product of the descending volcanic ejecta forms a chemical complex. This is different from the prior art that utilizes physical adsorption / aggregation action based on the porous structure of allophane.

That is, the present invention
A weathered product of a descending volcanic eruption is mixed with an object to be treated that contains a harmful substance easily eluted in water, and a harmful substance easily eluted in the water and a weathered product of the descending volcanic ejecta in the mixture are mixed. The present invention relates to a method for immobilizing harmful substances that are easily eluted in water, characterized by forming a hardly-eluting chemical complex by binding.

A preferred embodiment of the method for immobilizing a harmful substance that is easily eluted in water of the present invention is as follows.
The said to-be-processed object is 1 type, or 2 or more types selected from the group which consists of incineration ash, combustion ash, sludge, soil, waste, waste water, and waste liquid, The harmful | toxic which is easy to elute to the said water Immobilization method of substances,
The substance that easily elutes into water is one or more selected from the group consisting of boron, fluorine, arsenic, selenium, chromium, cyanide, phosphorus, cadmium, copper, zinc, lead, mercury, and molybdenum. A method for immobilizing harmful substances that easily dissolve in water,
The weathered product of the descending volcanic eruption contains allophane, the method for immobilizing harmful substances that easily dissolve in water,
The weathered product of the descending volcanic eruption product contains allophane whose particle size is adjusted to 20 μm or less by pulverization and / or sedimentation, and the method for immobilizing harmful substances easily eluted in water, The weathered product of the descending volcanic ejecta is one or more selected from the group consisting of sodium ion, potassium ion, calcium ion, magnesium ion, barium ion, aluminum ion, iron ion, copper ion and zinc ion The present invention relates to a method for immobilizing a toxic substance that easily elutes into water, comprising allophane having a metal ion supported on a silanol group.

The present invention also provides
Contains a mixture of a harmful substance easily eluted in water and a weathered product of a descending volcanic eruption, and a cement or a solidifying agent, which is formed by the immobilization method and forms a hardly-eluting chemical complex. The present invention relates to a material for civil engineering or construction.

Furthermore, the present invention provides
It is difficult to mix a weathered product of a descending volcanic eruption with an object to be treated that contains a material that easily dissolves in water, and it is difficult to combine the material easily eluted in the water with the weathered product of the descending volcanic ejecta. The present invention relates to a method for recycling a substance that is easily eluted in water, characterized in that it forms an eluting chemical complex and the chemical complex suitable for a particular application is removed from the mixture.

A preferred embodiment of the method for reusing a substance easily eluted in water of the present invention is as follows:
The substance to be treated is one or more selected from the group consisting of incineration ash, combustion ash, sludge, soil, waste, waste water, and waste liquid, and the substance easily eluted into the water How to reuse
The substance that easily elutes into water is one or more selected from the group consisting of boron, fluorine, arsenic, selenium, chromium, cyanide, phosphorus, cadmium, copper, zinc, lead, mercury, and molybdenum. A method for reusing a substance that is easily eluted in water,
The method of reusing a substance that easily dissolves in water, characterized in that the weathered product of the descending volcanic ejecta contains allophane.
The method for reusing a substance easily eluted in water, characterized in that the weathered product of the descending volcanic eruption product contains allophane whose particle size is adjusted to 20 μm or less by pulverization and / or sedimentation,
The weathered product of the descending volcanic ejecta is one or more selected from the group consisting of sodium ion, potassium ion, calcium ion, magnesium ion, barium ion, aluminum ion, iron ion, copper ion and zinc ion A method of reusing a substance that easily dissolves in water, characterized in that it contains allophane having a metal ion supported on a silanol group,
The substance that easily elutes into water is boron, and the chemical complex has the following formula: HOSiO ₃ Al ₂ (OH) ₂ B (OH) ₄
And the composition of the chemical composite has a molar ratio of Si / Al = 0.1 to 2.5, OH / Al = 0.5. 2.9 and Si / B = 1 to 2000, the method for reusing a substance easily eluted in water,
The substance that easily elutes into water is fluorine, and the chemical complex has the following formula: HOSiO ₃ Al ₂ (OH) ₂ F
And the chemical composite has a molar ratio of Si / Al = 0.1 to 2.5 and OH / Al = 0.5. 2.9 and Si / F = 1 to 2000, the method for reusing a substance easily eluted in water,
The substance easily eluted in water is arsenic, and the chemical complex is represented by the following formula (HO) ₃ Si ₃ O ₉ Al ₆ AsO ₄ (OH) ₆
And the chemical composite has a molar ratio of Si / Al = 0.1 to 2.5 and OH / Al = 0.5. 2.9 and Si / As = 1 to 2000, the method of reusing a substance easily eluted in water, and the substance easily eluted in water is selenium, and the chemical compound The body has the following formula (HO) ₃ Si ₃ O ₉ Al ₆ SeO ₄ (OH) ₆
And the composition of the chemical complex has a molar ratio of Si / Al = 0.1 to 2.5 and OH / Al = 0.5. It is related with the reuse method of the substance which is easy to elute in the said water characterized by being -2.9 and Si / Se = 1-2000.

  In addition, the present invention relates to a chemical complex obtained by the recycling method.

In the present invention, a harmful substance that easily elutes into water and a weathered product of a volcanic eruption deposit form a chemical complex, and therefore, the immobilization ability is higher than that of the conventional technique using physical adsorption. The weathered volcanic eruptions are made from raw materials such as weathered pumice and are available throughout the country, so they can be procured at low cost. Furthermore, the treatment work can be easily performed because only the weathered material is mixed into the object to be treated, the time required for the treatment work is short, and in order to treat a large amount of harmful substances, it is only necessary to increase the addition amount of the weathered material. Therefore, it can easily cope with an increase in processing amount. Therefore, the present invention can be preferably used for immobilizing harmful substances contained in incineration ash, sludge, construction residual soil, and the like.

  Moreover, the weathered material of the volcanic eruption used in the present invention can be immobilized by acting on a plurality of harmful substances at the same time. As a result, an appropriate treatment method has been known for each substance, but it is possible to overcome the problems of the prior art that the treatment cost increases or the treatment work becomes complicated when trying to treat a plurality of substances at the same time. It is useful for the treatment of waste water, waste liquid, etc. containing multiple substances to be treated.

  Furthermore, since the weathered material of the volcanic eruption used in the present invention is a geochemical substance that is naturally present in nature, no new environmental load is caused by the method of the present invention. Further, in the present invention, since harmful substances that are easily eluted in water form a chemical complex, they are stable for a long time without being re-eluted due to environmental changes as in the prior art. Due to these characteristics, the present invention can be preferably applied to in-situ treatment of contaminated soil.

  Furthermore, in the present invention, by controlling the amount of weathering of the descending volcanic ejecta, it is possible to use a trace amount of substances that are easily eluted in water from a hardly-elutable chemical complex, The chemical complex can be reused for various applications. Therefore, the chemical complex of the present invention is a material that can be preferably applied in applications in which a specific substance is required to be continuously released in minute amounts.

  The material to be treated in the present invention is not particularly limited as long as it contains a substance that easily dissolves in water that can form a weathered product of descending volcanic ejecta and a chemical complex that is difficult to elute, but in particular it is eluted in water. Examples include substances that are contaminated with harmful substances that are easily treated. Examples of such materials to be treated include coal ash (fly ash, clinker ash), coke ash, heavy oil ash, charcoal ash, incinerated ash such as slag, combustion ash, activated sludge, organic sludge such as paper sludge, gravel Examples include inorganic sludge such as cleaning sludge, cement factory wastewater treatment sludge, construction sludge, water and sewage sludge, construction soil, contaminated soil containing heavy metals, industrial waste, general waste, drainage, waste liquid, and the like. Further, the object to be processed may be a mixture of two or more of these.

  Hazardous substances that are contained in the material to be treated and easily eluted into water that forms a chemical complex with the weathered product of the descending volcanic ejecta include boron, fluorine, arsenic, selenium, chromium, cyanide, phosphorus , Cadmium, copper, zinc, lead, mercury, molybdenum and the like. In particular, coal ash attracting attention due to an increase in the amount of generation in recent years contains boron, fluorine, arsenic, selenium, etc., but the present invention also applies to coal ash containing such a large amount that it cannot be sufficiently eluted by the prior art. Can be effective. In addition, even if the material to be treated contains two or more types of substances that are likely to elute in water, the weathered products of the descending volcanic products form a difficult-to-leach chemical complex that is different from each substance. And can be fixed in a multi-factorial manner.

  The fallen volcanic eruption weathering used in the present invention is, for example, a volcanic ash or pumice weathering, and contains allophane, which is a basic aluminum silicate, as one of its components. Allophane is a porous material having a large number of fine pores having a diameter of about 3 to 5 μm, and has been known as a physical adsorbent or aggregating material in the prior art. However, the present invention is clearly different from the prior art in that the weathered material of the descending volcanic eruption and a harmful substance that easily elutes into water form a chemical complex.

Moreover, in this invention, it grind | pulverizes or sinks with respect to the weathering thing of the said descending volcanic ejecta, and can adjust the particle size of the said allophane. The particle size of the allophane is, for example, 20 μm or less, preferably 2 μm, and particularly preferably 0.2 μm or less.

  Furthermore, a metal ion can be carried on the silanol group of the allophane, and the chemical complex forming action of the weathered product of the descending volcanic ejecta can be controlled. Examples of the metal ions to be supported include sodium ions, potassium ions, calcium ions, magnesium ions, barium ions, aluminum ions, iron ions, copper ions, zinc ions, etc., and one or more of these ions Can be supported.

The feature of the present invention resides in that a harmful substance that is easily eluted in water and a weathered product of the descending volcanic ejecta form a chemical complex. Allophane, which is one component of the weathering of the descending volcanic ejecta, includes a portion made of Si—O 2 ⁻ and a portion made of Al—OH ₂ ^{+ in} the pores, the former being lead, copper, zinc, It binds to a substance having a cation form such as cadmium, and the latter forms a chemical complex on the allophane surface by combining with a substance having an anion form such as fluorine, boron, arsenic, and selenium. Once this chemical complex is formed, even if other cations or anions approach the chemical complex, reactions such as ion exchange and ligand exchange do not proceed, and it is easy to elute into water. The material remains sparingly soluble.

The specific structure of the chemical complex is, for example, when the harmful substance easily eluted in water is boron, the chemical complex has the following formula: HOSiO ₃ Al ₂ (OH) ₂ B (OH) ₄
The basic aluminum silicate borate partial structure represented by these. The composition of the chemical complex is Si / Al = 0.1 to 2.5, OH / Al = 0.5 to 2.9, and Si / B = 1 to 2000 in terms of molar ratios. Theoretical values are Si / Al = 0.5, OH / Al = 1.5, and Si / B = 2.55.

When the harmful substance easily eluted in water is fluorine, the chemical complex has the following formula: HOSiO ₃ Al ₂ (OH) ₂ F
It has the partial structure of basic aluminum silicate hydrofluoric acid represented by these. The composition of the chemical complex is Si / Al = 0.1 to 2.5, OH / Al = 0.5 to 2.9, and Si / F = 1 to 2000 in molar ratios. The theoretical values are Si / Al = 0.5, OH / Al = 1.5, and Si / F = 1.47.

Furthermore, when the harmful substance easily eluted in water is arsenic, the chemical complex is represented by the following formula (HO) ₃ Si ₃ O ₉ Al ₆ AsO ₄ (OH) ₆
And the composition of the chemical complex has a molar ratio of Si / Al = 0.1 to 2.5 and OH / Al = 0.5. 2.9 and Si / As = 1 to 2000, and the theoretical values are Si / Al = 0.5, OH / Al = 1.5, and Si / As = 1.12.

Similarly, when the harmful substance easily eluted in water is selenium, the chemical complex has the following formula: (HO) ₃ Si ₃ O ₉ Al ₆ SeO ₄ (OH) ₆
And the composition of the chemical composite has a molar ratio of Si / Al = 0.1 to 2.5, OH / Al = 0.5. 2.9 and Si / Se = 1 to 2000, and the theoretical values are Si / Al = 0.5, OH / Al = 1.5, and Si / Se = 1.06.

  In the present invention, the chemical complex of the object to be treated containing a harmful substance that easily elutes into water and the weathered product of the descending volcanic eruption are either directly kneaded or both in the operation process of the mechanical device. Can be formed in contact with each other. In the latter case, the contacting method is not limited to kneading, and various conventional methods can be used.

  Non-treated materials containing harmful substances that are easily eluted in water treated by the method of the present invention are mixed with cement, solidifying agent, etc., and formed into a desired shape, and then reused as civil engineering materials or construction materials. it can. Further, in the present invention, even if a weathered product of descending volcanic ejecta is added to the object to be processed, the physical properties (specific gravity, volume, hardness, appearance, strength, etc.) of the object to be processed before the addition do not change greatly. In addition, a material having characteristics required for civil engineering or construction applications can be easily obtained.

  Further, the chemical complex of the present invention contains a substance that is easily eluted in water in the object to be treated in a hardly soluble state. In other words, the difficult-to-leach chemical complex is controlled by controlling the amount of weathering in the descending volcanic eruption, so that it is gradually released in a very small amount to the immobilized substance. Can be given. Therefore, the chemical complex of the present invention can be preferably used for an application in which a substance that is easily eluted in water is required to be continuously released in a minute amount. As a specific example of such use, for example, in the case of a chemical complex containing boron, fluorine, such as a slow-release slow-release boron fertilizer for articles, microorganisms, animals, etc. that require boron, is used. In the case of chemical complexes containing, in the case of chemical complexes containing arsenic or selenium, etc., as well as drinking water, toothpaste, toothpaste preventives for toothpaste etc. utilizing the property of curing hydroxyapatite These include antibacterial agents, biocides, and the like for rodents such as bacteria and spiders and wild birds whose biological functions are disturbed by arsenic or selenium.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in more detail, it is not intending limiting this invention to an Example.

Examples 1 to 5 and Comparative Example 1
Coal ash (fly ash) containing toxic substances that easily elute in a plurality of waters was used as an object to be treated. Moreover, the weathered pumice derived from Oyama obtained in Kurayoshi, Tottori Prefecture, was pulverized, and the product obtained by adjusting the particle size to 2 μm or less with hydrangea was used as a weathered product of descending volcanic ejecta.
85 g of the material to be treated is mixed with 15 g of cement, and 0.1 wt%, 0.5 wt%, 1.0 wt%, 5.0 wt% and 10 wt% with respect to 100 g of the total weight of the obtained mixture. Weathering of descending volcanic eruptions was added at a rate of% addition. Next, 20 g of water was added and this was kneaded well to produce the hardly eluting mixture of Examples 1-5. Moreover, the composition which does not add the weathering thing of a descending volcanic ejecta as the comparative example 1 was also manufactured.

The dissolution test was performed on the objects to be processed in Examples 1 to 5 and Comparative Example 1 thus obtained. In the dissolution test, coal ash was previously solidified with cement using a conventional cement, and substances that were confirmed to be eluted from the material to be treated: boron, fluorine, arsenic, and selenium, which are easily dissolved in coal ash. As an element to be tested.
The test specimen is 7 days old according to the “Guideline for the Hexavalent Chromium Dissolution Test Using Cement and Cement-based Solidifying Agents; Ministry of Land, Infrastructure, Transport and Tourism”. The one prepared in accordance with the method of Agency Notification No. 46 was used.
The measurement of the test object is JIS K 0102 47.1 and 47.3 for boron, JIS K 0102 34.1 for fluorine, JIS K 0102 61 for arsenic, and JIS K 0102 67. for selenium. 2 and 67.3.

The dissolution test results are shown in FIGS. FIG. 1 shows a boron dissolution test result, FIG. 2 shows a fluorine dissolution test result, FIG. 3 shows a arsenic dissolution test result, and FIG. 4 shows a selenium dissolution test result. The axis indicates the addition rate of weathering in descending volcanic ejecta, and the vertical axis indicates the concentration (ppm) of each eluted element.
The boron elution test result shown in FIG. 1 shows that the elution concentration (initial elution concentration, Comparative Example 1) was 0.42 ppm when the weathered product addition rate of the descending volcanic ejecta was 0%. When the addition rate was 10% (Example 5), the elution concentration decreased greatly. Moreover, in all the Examples, the elution density | concentration was 1 ppm or less which is an environmental standard.
The fluorine elution test results shown in FIG. 2 showed that the elution concentration decreased significantly as the addition rate increased with respect to the initial elution concentration of 2.53 ppm, and elution suppression could be expected with a small addition.
The results of the arsenic dissolution test shown in FIG. 3 showed that the dissolution concentration markedly decreased as the addition rate increased with respect to the initial dissolution concentration of 0.104 ppm.
The results of the selenium dissolution test shown in FIG. 4 show that, with respect to the initial dissolution concentration of 0.147 ppm, the dissolution concentration is already greatly reduced at an addition rate of 0.1% (Example 1), and the addition rate is 10% (Example). 5) indicates that the value was half of the initial elution concentration.
In addition, from these results, the elution concentration of all four elements is reduced in the difficult-to-elution mixture of the present invention, and even if the object to be treated contains a plurality of substances in an elution state, It was shown that it can be effectively hardly eluted only by adding a weathered product.

FIG. 1 is a graph showing boron dissolution test results for the hardly eluted mixtures of Examples 1 to 5 and Comparative Example 1. FIG. 2 is a graph showing fluorine elution test results for the hardly-eluted mixtures of Examples 1 to 5 and Comparative Example 1. FIG. 3 is a graph showing the results of an arsenic dissolution test on the hardly eluted mixtures of Examples 1 to 5 and Comparative Example 1. FIG. 4 is a graph showing selenium dissolution test results for the hardly eluted mixtures of Examples 1 to 5 and Comparative Example 1.

Claims (21)

A weathered product of a descending volcanic eruption is mixed with an object to be treated that contains a harmful substance easily eluted in water, and a harmful substance easily eluted in the water and a weathered product of the descending volcanic ejecta in the mixture are mixed. A method for immobilizing a harmful substance that is easily eluted in water, characterized by forming a hardly-eluting chemical complex by binding. 2. The water according to claim 1, wherein the object to be treated is one or more selected from the group consisting of incineration ash, combustion ash, sludge, soil, waste, waste water, and waste liquid. A method for immobilizing harmful substances that are easily eluted. The substance that easily elutes into water is one or more selected from the group consisting of boron, fluorine, arsenic, selenium, chromium, cyanide, phosphorus, cadmium, copper, zinc, lead, mercury, and molybdenum. The method for immobilizing a toxic substance that is easily eluted in water according to claim 1. The method for immobilizing harmful substances that easily dissolve in water according to claim 1, wherein the weathered product of the descending volcanic ejecta contains allophane. 5. The fixing of harmful substances easily eluted in water according to claim 4, wherein the weathered product of the descending volcanic ejecta contains allophane whose particle size is adjusted to 20 μm or less by crushing and / or sinking. Method. The weathered product of the descending volcanic ejecta is one or more selected from the group consisting of sodium ion, potassium ion, calcium ion, magnesium ion, barium ion, aluminum ion, iron ion, copper ion and zinc ion 5. The method for immobilizing harmful substances that are easily eluted in water according to claim 4, comprising allophane in which the metal ions are supported on silanol groups. Weathering of harmful substances that easily leach into water that forms a poorly-eluting chemical complex obtained by the immobilization method according to any one of claims 1 to 6 and falling volcanic ejecta A material for civil engineering or construction, comprising a mixture with a material and cement or a solidifying agent. It is difficult to mix a weathered product of a descending volcanic eruption with an object to be treated that contains a material that easily dissolves in water, and it is difficult to combine the material easily eluted in the water with the weathered product of the descending volcanic ejecta. A method for reusing a substance that is easily eluted in water, comprising forming an eluting chemical complex and removing the chemical complex suitable for a specific application from the mixture. 9. The water according to claim 8, wherein the object to be treated is one or more selected from the group consisting of incineration ash, combustion ash, sludge, soil, waste, waste water, and waste liquid. A method for reusing easily eluted substances. The substance that easily elutes into water is one or more selected from the group consisting of boron, fluorine, arsenic, selenium, chromium, cyanide, phosphorus, cadmium, copper, zinc, lead, mercury, and molybdenum. The method for reusing a substance that is easily eluted in water according to claim 8. The method for reusing a substance that is easily eluted in water according to claim 8, wherein the weathered product of the descending volcanic ejecta contains allophane. 12. Reuse of water-elutable substance according to claim 11, wherein the weathered product of the descending volcanic ejecta contains allophane whose particle size is adjusted to 20 μm or less by crushing and / or sinking. Method. The weathered product of the descending volcanic ejecta is one or more selected from the group consisting of sodium ion, potassium ion, calcium ion, magnesium ion, barium ion, aluminum ion, iron ion, copper ion and zinc ion 12. The method for reusing a substance that is easily eluted in water according to claim 11, comprising allophane in which the metal ion is supported on a silanol group. The substance that easily elutes into water is boron, and the chemical complex has the following formula: HOSiO ₃ Al ₂ (OH) ₂ B (OH) ₄
And the composition of the chemical composite has a molar ratio of Si / Al = 0.1 to 2.5, OH / Al = 0.5. The method for reusing a substance easily eluted in water according to claim 8, wherein ˜2.9 and Si / B = 1 to 2000. The substance that easily elutes into water is fluorine, and the chemical complex has the following formula: HOSiO ₃ Al ₂ (OH) ₂ F
And the chemical composite has a molar ratio of Si / Al = 0.1 to 2.5 and OH / Al = 0.5. -2.9 and Si / F = 1-2000, The recycling method of the substance which is easy to elute in water of Claim 8 characterized by the above-mentioned. The substance easily eluted in water is arsenic, and the chemical complex is represented by the following formula (HO) ₃ Si ₃ O ₉ Al ₆ AsO ₄ (OH) ₆
And the chemical composite has a molar ratio of Si / Al = 0.1 to 2.5 and OH / Al = 0.5. The method for reusing a substance that easily dissolves in water according to claim 8, wherein ˜2.9 and Si / As = 1 to 2,000. The substance that is easily eluted in water is selenium, and the chemical complex has the following formula (HO) ₃ Si ₃ O ₉ Al ₆ SeO ₄ (OH) ₆
And the composition of the chemical complex has a molar ratio of Si / Al = 0.1 to 2.5 and OH / Al = 0.5. -2.9 and Si / Se = 1-2000, The reuse method of the substance which is easy to elute in water of Claim 8 characterized by the above-mentioned. A chemical complex obtained by the recycling method according to claim 14. A chemical complex obtained by the recycling method according to claim 15. A chemical complex obtained by the recycling method according to claim 16. A chemical complex obtained by the recycling method according to claim 17.

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