JP2005305416A5 - - Google Patents

Description

Calcium or metal chloride-introduced plants and carbides used in the production of anion-adsorbing carbon materials and methods for producing them

  The present invention relates to a calcium or metal chloride-introduced plant and carbide used for the production of an anion-adsorbing carbon material that adsorbs anions such as nitrate ions and fluoride ions, and methods for producing them.

  Water and soil contamination by heavy metals, pesticides and organochlorine compounds are problematic as they destroy the environment. These harmful substances can be adsorbed and removed by adsorbents such as activated carbon and zeolite, but nitrate nitrogen or nitrite nitrogen, fluorine, arsenic, cyanide, etc. present in the form of anions are difficult to treat with adsorbents. It is.

  For example, nitrate nitrogen and nitrite nitrogen are serious problems of groundwater contamination due to fertilization in tea plantations and golf course turf, etc., and countermeasures are necessary, but no effective methods have been found. . Nitrate ions and nitrite ions have a negative charge and do not combine with other substances to form a sparingly soluble salt, so they are most easily leached from negatively charged soils. In addition to being a problem, recently it has been suspected of being an environmental hormone. Nitric acid contamination is becoming more widespread because there are limitations such as the need for anaerobic conditions even in microbial treatment using denitrifying bacteria, and there is no inexpensive material that adsorbs anions. Similarly, once the other anions are contaminated, a great deal of cost is required to repair them.

Fluorine is contained in wastewater from semiconductors, glass, plating plants, etc., and fluorine in factory effluent is removed by adding calcium compounds as calcium fluoride. It is necessary to install an adsorption tower with an anion exchange resin, which is expensive. Further, if the environmental standard is 0.8 mg / L or less, an expensive dedicated anion exchange resin is required. In addition, arsenic and cyanide require expensive anion exchange resins for the treatment of industrial wastewater and groundwater contamination.
Japanese Patent Laid-Open No. 10-165824

  Therefore, there is a need for an anion adsorption material that is inexpensive and environmentally friendly. Charcoal, which is a representative of porous carbon materials together with activated carbon, is widely used as a humidity control material, river purification, and soil improvement material, and is also used, for example, to remove chlorine-based gases and sulfur oxides in exhaust gas. However, this uses only the adsorption characteristics due to the fine pores inside the porous carbon material as in the case of activated carbon, and nitrate nitrogen or nitrite nitrogen existing in the form of an anion, fluorine, arsenic, Cyanide hardly adsorbs.

  The present invention has been made in consideration of the above-mentioned matters, and its object is to introduce a calcium or metal chloride-introduced plant used in the production of an anion-adsorbing carbon material which is inexpensive, environmentally friendly and excellent in anion adsorption. , Providing carbides and methods for their production.

Calcium transgenic plants used in the production of an anion adsorbing carbon material according to claim 1, the functional group formed in the micropores walls having carbide carbonized raw material consisting of plants, either directly or through a calcium, adsorption This is a calcium-introduced plant used in the production of anion-adsorbing carbon material that combines anion that can be ion-exchanged with the target anion , and the solution containing calcium ions is contacted before carbonizing the plant material. It is characterized by becoming.

The method for producing a calcium-introduced plant used for producing the anion-adsorbing carbon material according to claim 2 is characterized in that a functional group formed on a microporous wall of a carbide obtained by carbonizing a plant material is directly or via calcium. Te, a calcium introduction method for producing a plant used in the production of an anion adsorbing carbon material anion and the ion exchange was bound anions capable of adsorbing the target, the calcium ions prior to carbonization the material consisting of plant It is characterized by contacting the solution containing it.

The carbide used for the production of the anion-adsorbing carbon material according to claim 3 is a functional group formed on the fine pore wall of the carbide obtained by carbonizing the plant raw material, directly or via calcium . Carbide used in the production of anion-adsorbing carbon materials that combine anions that can exchange ions with anions, and is obtained by carbonizing a calcium-introduced plant in which a solution containing calcium ions is contacted with a plant material. It is characterized by that.

The method for producing a carbide used for producing the anion-adsorbing carbon material according to claim 4, wherein the functional group formed on the microporous wall of the carbide obtained by carbonizing the plant raw material is directly or via calcium. This is a method for producing carbides used in the production of anion-adsorbing carbon materials in which the anion to be adsorbed and an anion that can be ion-exchanged are combined, and calcium is introduced by bringing a solution containing calcium ions into contact with a plant material It is characterized by carbonizing plants.

The inventors of the present invention prior to carbonizing a plant raw material, a solution containing calcium ions in the raw material in advance (desirably containing mainly calcium ions as cations), for example, a solution of calcium hydroxide (lime water) Alternatively, suspension (lime milk) is contacted to introduce Ca (calcium) into the raw material, and then the Ca-introduced raw material is carbonized, and the resulting Ca-introduced charcoal is made of HCl, H ₂ SO _4, etc. As a result of studying the anion adsorption performance of the material in contact with the acid, it came to know the excellent anion adsorption performance, although it depends on the carbonization temperature and acid concentration of plant materials such as natural fibers and woody materials. It was.

As a method of bringing the solution containing calcium ions into contact with the plant material, the solution containing calcium ions can be dropped, applied, sprayed, sprayed, etc., but the material is immersed in the solution containing calcium ions. Is the most efficient. The acid solution can be brought into contact with the carbide by dropping, coating, spraying, spraying, or the like of the acid solution, but it is most efficient to immerse the raw material in the acid solution.
Examples of the solution containing calcium include calcium acetate solution and calcium chloride solution in addition to lime water and lime milk. The calcium content is 0.03 to 30% by weight, more preferably 0.1 to 7.0% by weight. Are preferred.

  In the present invention, a solution containing calcium ions, such as lime water or lime milk, is brought into contact with a plant material. That is, when the raw material is immersed in a solution containing calcium ions, a Ca-introduced chip can be obtained by the solution soaking into the raw material. In particular, when an alkaline solution is used as a solution containing calcium ions, as shown in FIG. 6A, when a wood chip 2 as a raw material made of a plant is brought into contact with, for example, lime water H, a Ca-introduced chip 30 [FIG. 6 (C)] is obtained. This is because, as shown in FIG. 6 (B), the organic matter in the wood chip 2 is dissolved by alkali, and calcium ions react with the components of the wood chip 2. it is conceivable that. In this case, the concentration of lime water or lime milk is preferably 0.1 to 50% by weight of calcium hydroxide, and more preferably 0.2 to 10% by weight.

  Subsequently, the obtained Ca introduction chip 30 [see FIG. 7A] is carbonized to obtain a Ca introduction charcoal (hereinafter simply referred to as Ca charcoal) 31 [see FIG. 7C]. Sometimes, the organic substance in the Ca-introduced chip 30 (see FIG. 7B) is decomposed by heat, and at the same time, calcium ions are deposited on the surface of the fine pore wall of the Ca-introduced chip 30 (see FIG. 7C). Conceivable. In this case, since calcium ions are deposited on the surface of the fine pore wall of the Ca-introduced chip 30 (see FIG. 7B), a fine and highly dispersed state results in many functional groups at the corners of the fine pore wall. It is thought that it is drawn from people.

Further, the present invention intensively studied, before carbonizing a raw material consisting of plants, a solution containing a pre-metal chlorides in the raw materials, for example the CaCl ₂ in the raw material by contacting a solution containing CaCl ₂ If the raw material into which the CaCl ₂ was introduced was carbonized after introduction, the carbonized material obtained thereby was found to have excellent anion adsorption performance.

Therefore, the metal chloride-introduced plant used in the production of the anion-adsorbing carbon material according to claim 5 directly or metal is added to the functional group formed on the fine pore wall of the carbide obtained by carbonizing the plant raw material. Is a metal chloride-introduced plant used for the production of anion-adsorbing carbon materials in which anion to be adsorbed and ion-exchangeable chloride ions are combined. It is characterized by contacting a solution containing an object.

The method for producing a metal chloride-introduced plant used for producing the anion-adsorbing carbon material according to claim 6 is characterized in that a functional group formed on a microporous wall of a carbide obtained by carbonizing a plant raw material is directly or metal Is a method for producing a metal chloride-introduced plant used in the production of an anion-adsorbing carbon material in which an anion to be adsorbed and an ion-exchangeable chloride ion are combined, and carbonizes the plant material It is characterized by contacting a solution containing a metal chloride in advance.

The carbide used for the production of the anion-adsorbing carbon material according to claim 7 is a functional group formed on a fine pore wall of a carbide obtained by carbonizing a plant raw material, directly or via a metal . This is a carbide used in the production of anion-adsorbing carbon materials that combine anions and chloride ions that can be ion-exchanged, and a metal chloride-introduced plant in which a solution containing metal chloride is brought into contact with a plant material. It is characterized by being carbonized.

The method for producing a carbide used for producing the anion-adsorbing carbon material according to claim 8, the functional group formed on the fine pore wall of the carbide obtained by carbonizing the raw material consisting of a plant, directly or via a metal, This is a method for producing carbides used in the production of anion-adsorbing carbon materials in which anions to be adsorbed and ion-exchangeable chloride ions are combined. The plant material is brought into contact with a solution containing metal chloride. It is characterized by carbonizing a metal chloride-introduced plant.

  In the invention according to claims 5 to 8, since the chloride ion of the metal chloride contained in the carbide expresses the anion exchange ability, the carbide functions as an anion adsorbing material. In addition, the introduction treatment of the metal chloride to the raw material plant can be performed by bringing the solution containing the metal chloride into contact with the raw material plant. Examples of the contact method include dropping, coating, spraying, spraying, and the like of the solution. Although it is possible, it is most efficient to immerse the raw plant in the solution.

In the inventions according to claims 5 to 8, the raw material plant is immersed in a solution containing, for example, CaCl ₂ as a metal chloride, and Ca ions and Cl ions are introduced into the raw material, and then the CaCl ₂ introduction material CaCl ₂ -introduced charcoal obtained by carbonizing is excellent in anion adsorption performance.

That is, for example, as shown in FIG. 12 (A), the wood chip 2 as a raw material is immersed in CaCl ₂ solution 100 is contacted to the CaCl ₂ solution 100, the Ca ions and Cl ions in CaCl ₂ solution 100 When introduced into the wood chip 2, a CaCl ₂ introduction chip 101 is obtained as shown in FIG. This is because the CaCl ₂ solution 100 soaks into the tissue in the wood chip 2, particularly the passage tissue, as shown in FIG. As the concentration of the CaCl ₂ solution 100 used in the pretreatment of the raw material (contact treatment), CaCl ₂ 0.1 wt% to 50 wt% by weight, and cost more preferably 1 wt% to 20 wt%. If the amount is less than 0.1% by weight, a high anion adsorption ability is not expressed, and if it exceeds 50% by weight, the anion adsorption ability is not improved.

Subsequently, when the CaCl ₂ introduction chip 101 is carbonized as shown in FIG. 13A, a metal chloride charcoal 90a is obtained as shown in FIG. In this carbonization process, organic substances in the CaCl ₂ introduction chip 101 are decomposed by heat, and at the same time, Cl ions and Ca ions are deposited on the surface of the fine pore wall of the CaCl ₂ introduction chip 101. At this time, as shown in FIG. 5B, Cl ions and Ca ions are deposited in a fine and highly dispersed state on the surface of the fine pore wall of the CaCl ₂ introduction chip 101, and many functional groups are formed at every corner of the fine pore wall. Pull out from. As a result, as shown in FIG. 4C, it is considered that Cl ions are bonded to a large number of functional groups drawn out on the surface of the microporous wall via a metal (in this case, Ca ions) or directly. .

  In addition, as content of the said metal chloride, it is preferable to contain 2%-25% of metal chloride couple | bonded in the said carbide | carbonized_material as ash. The metal chloride bonded in the carbide is a metal chloride except for the metal chloride that is simply adhered in the carbide. Since it is bonded in the carbide, it does not dissolve after washing with water or acid. The metal chloride remaining in If it is less than 2%, the anion adsorption ability is inferior, and even if it exceeds 25%, the anion adsorption ability tends not to be improved.

  Furthermore, in the invention which concerns on Claims 5-8, it is preferable to contact the said carbide | carbonized_material with water and / or an acid. In addition, as a method of bringing water and / or acid into contact with the carbide, water and / or acid can be dropped, applied, sprayed, sprayed, etc., but the carbide is immersed in water and / or acid. Is the most efficient.

Here, the reason why it is preferable to contact the carbide with water and / or an acid is considered as follows. That is, the metal chloride charcoal (CaCl ₂ charcoal) 90a obtained as shown in FIGS. 12 and 13 is immersed (contacted) in an acid such as hydrochloric acid 102 or sulfuric acid, as shown in FIG. 14 (A). ), Excess metal chloride crystals adhering to the purification material 1 are removed. In addition, when hydrochloric acid 102 is used as the acid, Cl ions bonded to the functional group of the purification material 1 are newly increased, and the state changes from the state (B) to the state (C). From the above, the produced anion adsorption ability is preferably increased. Even when the carbide is brought into contact with water instead of acid such as hydrochloric acid 102, excess metal chloride crystals adhering to the metal chloride charcoal 90a are removed, and the anion adsorption ability is improved. it can.

Specifically, examples of the metal chloride include CaCl _{2 and} BaCl ₂ .

As a raw material consisting of a plant in the present invention according to claims 1 to 8, it can be applied as long as it is a plant body, but it is composed of one or more of natural fibers and woody materials, and the raw material carbide has fine pores. Desirably, for example, all woody materials such as thinned wood, felled wood, waste wood, and natural fibers such as hemp can be mentioned. Specifically, it is preferable to use a wood chip in which conifers such as cypress and cedar having high water absorption are chipped to a size of, for example, 50 mm or less (preferably 10 mm or less). Bamboo, sawdust, rice husk, coconut, areca, jute, and straw can also be used as plant materials. In addition to this, examples of the raw material comprising the plant include agricultural waste such as mandarin oranges, apple peels and pomace. Moreover, the part which has a passage tissue (a road pipe, a temporary path pipe, or a mental pipe) in a plant body is preferable as a raw material which consists of a plant.
In the case of using a solution (for example, lime water or lime milk) that contains almost no anion (for example, chloride ion) ion-exchangeable with the anion to be adsorbed as the solution in contact with the material (for example, lime water or lime milk), Preferably, when carbon is introduced and then carbonized, countless Ca compounds having a particle size of 100 nm or less are formed in the fine pores of the carbide.
In addition, when using a solution (for example, calcium chloride solution or calcium acetate solution) containing both an anion (for example, chloride ion) ion-exchangeable with the anion to be adsorbed and calcium ion, it is immersed in the solution as the raw material. In this case, it is desirable that the solution easily penetrates.

  As carbonization temperature of the raw material which consists of plants, 400 degreeC-1000 degreeC can be mentioned, 500 degreeC-900 degreeC is preferable, and 650 degreeC-750 degreeC is more preferable. When the temperature is lower than 400 ° C., the pores do not develop and the performance as an adsorbent is inferior. Further, at temperatures exceeding 1000 ° C., there is a disadvantage that adsorption characteristics cannot be obtained due to excessive carbonization.

  Since the carbide | carbonized_material used for manufacture of the anion adsorption | suction carbon material of this invention which concerns on Claims 1-4 has carbonized the raw material which consists of a plant which contacted the solution containing a calcium ion, an acid solution is made to contact this carbide | carbonized_material. By doing so, an anion capable of ion exchange with the anion to be adsorbed can be bound to the functional group extracted from the fine pore wall of the carbide. As a result of intensive studies, the present inventors have found that more functional groups of carbides can be generated by controlling the temperature and time during the carbonization process.

  That is, when calcium is contacted in advance with the raw material, the carbonization temperature of about 600 ° C. and about 800 ° C. is 1 when the carbonization temperature of 650 ° C. to 750 ° C. is maintained for, for example, 1 hour and then naturally cooled. The present inventors have confirmed that a larger number of functional groups can be formed as compared with the case where the liquid is naturally cooled after being kept for a period of time. In particular, when calcium is contacted, when observed with an electron microscope, in the carbide carbonized at a carbonization temperature of 650 ° C. to 750 ° C. as described above, fine particles of the calcium compound are semi-deposited on the fine pore wall surface and uniformly dispersed. I was observed. On the other hand, at the carbonization temperature of about 600 ° C., it was observed that the calcium compound fine particles were not sufficiently precipitated on the fine pore wall surfaces. Further, at the carbonization temperature of about 800 ° C., although the precipitation of calcium compound fine particles on the fine pore wall surface was observed, it was observed that the number of missing portions was increased. Thus, as described above, 650 ° C. to 750 ° C. can be given as the carbonization temperature necessary for calcium to extract as many functional groups as possible from the fine pore wall surface of the carbide.

  The invention described in claims 1 and 2 is a Ca-introduced plant as an intermediate for producing an anion-adsorbing carbon material, and a method for producing the Ca-introduced plant, wherein a solution containing Ca ions is brought into contact with a plant material By making Ca into the plant, compared with the carbide obtained by simply carbonizing the plant material, when the carbide is brought into contact with the acid solution, the carbide has a very large number of anion-exchangeable anions. A Ca-introduced plant that can be bonded to a functional group formed on the pore wall can be obtained.

  Invention of Claim 3, 4 is the carbide | carbonized_material as an intermediate body which manufactures an anion adsorption carbon material, and the manufacturing method of the carbide | carbonized_material, By carbonizing the said Ca introduction | transduction plant, the organic substance in Ca introduction | transduction plant Is decomposed by heat, and Ca ions are deposited on the surface of the microporous wall of the Ca-introduced plant. At this time, Ca ions are precipitated on the surface of the fine pore wall and become fine and highly dispersed, so that many functional groups are drawn out from every corner of the fine pore wall. Carbides can be obtained that can bind many ion-exchangeable anions to their functional groups.

In addition, the carbide formed by carbonizing the Ca-introduced plant in the inventions of claims 1 and 2 and the carbide in the inventions of claims 3 and 4 are brought into contact with an acid solution such as an HCl solution on the fine pore walls. By this, anions such as chloride ions capable of ion exchange with anions such as nitrate nitrogen and nitrite nitrogen to be adsorbed can be bound to the functional groups extracted from the fine pore walls. . This is because, for example, when the Ca charcoal 31 is immersed in, for example, an HCl solution 3a [see FIG. 8A], chloride ions are bound to the functional groups on the surface of the fine pore walls of the Ca charcoal 31 and the Bonded to a functional group (see FIGS. 8B and 8C), acid-treated Ca charcoal 32 in which chloride ions are bonded to the functional group via calcium ions or directly (see FIG. 8D) ] Is considered to be obtained. When HCl or H ₂ SO ₄ is used as the acid solution, there is no problem with the waste water treatment at the time of manufacture, which is environmentally friendly.

  In the inventions according to claims 5 to 8, the same effects as those of the inventions according to claims 1 to 4 can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited thereby.

1 and 2 show a first embodiment of the present invention.
1 and 2, an acid-treated Ca charcoal 32, which is an example of an anion-adsorbing carbon material, is a natural fiber such as hemp or a plant woody material (an example of a plant raw material) 2 such as wood. (Means for contacting lime water or lime milk of appropriate concentration, which is a solution H containing calcium ions, with a raw material consisting of plants) 9) After being dipped in the solution H containing calcium ions prepared in 9, a dryer 12 is used for drying. Then, carbonization is performed in a carbonization furnace (an example of carbonization means) 1, and then the carbide generated in the carbonization means 1 is immersed in an acid solution 3 a such as HCl or H ₂ SO _{4 in} an acid treatment apparatus 3 that is immersed in an acid solution. Further, it is obtained by drying with a dryer 6.

  In this embodiment, a wood chip is used as a raw material (hereinafter simply referred to as a raw material) 2 made of the plant. This wood chip 2 is formed by converting a softwood such as cypress or cedar having high water absorption into a size of, for example, 50 mm or less (preferably 10 mm or less). The Ca introduction device 9 is a device that introduces Ca into the wood chip 2 and includes a container 10 that contains a solution H containing calcium ions into which the wood chip 2 is immersed. In this embodiment, the wood chip 2 is immersed in the solution H containing calcium ions, and after the wood chip 2 is immersed in lime water having a predetermined concentration (for example, 5% by weight) as the solution H containing calcium ions, the container 10 The Ca introduction | transduction chip | tip 30 in which Ca was introduce | transduced is obtained by taking out.

  In this case, in order to sufficiently soak the solution H into the wood chip 2 or to sufficiently react calcium ions with the components of the wood chip 2, the stirring blade 10a provided inside the container 10 is driven during the wood chip immersion. Is preferred. The obtained Ca introduction chip 30 is dried by the dryer 12. In this embodiment, the dryer 12 dries the Ca introduction chip 30 using carbonization furnace exhaust heat. In addition, the processing efficiency is better when lime milk is used. As the solution H, a calcium chloride solution or a calcium acetate solution can be used instead of lime water or lime milk.

That is, the Ca-introduced chip 30 is an example of a Ca-introduced plant used in the production of the anion-adsorbing carbon material 32 in claim ₁ , and the steps M1 surrounded by a two-dot chain line in FIGS. 1 shows an example of a method for producing a Ca-introduced plant 30 used for producing the anion-adsorbing carbon material 32 in FIG. However, the method for producing the Ca-introduced plant 30 of the present invention is not limited to using the dryer 12, and the drying step using the dryer 12 can be omitted.

Next, the dried Ca-introduced chip 30 is carbonized in the carbonization furnace 1 to obtain chip-like Ca charcoal 31. In this embodiment, the carbonization conditions are such that the carbonization temperature is 650 ° C. to 750 ° C., and is preferably around 700 ° C. as much as possible. That is, an example of carbides Ca charcoal 31 is used in the production of anion adsorbing carbon material 32 in claim 3, 1 and 2, the anion adsorbing carbon step M ₂ surrounded by a one-dot chain line in claim 4 An example of the manufacturing method of the carbide | carbonized_material 31 used for manufacture of the material 32 is shown.

The acid treatment device 3 includes a container 4 containing an acid solution 3 a such as HCl or H ₂ SO ₄ , and a stirring blade 5 is provided inside the container 4. The concentration of the acid solution 3a is, for example, 5 mol / L. The acid treatment apparatus 3 is for obtaining acid-treated Ca charcoal 32 by acid-treating chip-like Ca charcoal 31 obtained in the carbonization furnace 1. In order to promote the dissolution of calcium carbonate (CaCO ₃ ) on the surface of the Ca charcoal 31 by the acid, and to sufficiently react the chloride ion and the calcium ion with the functional group on the surface of the fine pore wall of the Ca charcoal 31. The stirring blade 5 provided inside the container 4 is preferably driven. The obtained acid-treated Ca charcoal 32 is dried by the dryer 6. In this embodiment, the dryer 6 dries the acid-treated Ca charcoal 32 using carbonization furnace exhaust heat.

  Then, (1) acid-treated Ca charcoal 32 that can be used immediately after acid treatment and drying is processed into a product as it is as an anion-adsorbing carbon material. (2) If necessary, the acid-treated Ca charcoal 32 may be neutralized with an alkali after acid treatment. In this case, (3) the neutralized acid-treated Ca charcoal is washed with water as necessary. Also good. When used in a wet state, drying may be omitted.

  7 ′ is a product obtained by pelletizing the acid-treated Ca charcoal 32, and 8 ′ is a product formed by pulverizing the acid-treated Ca charcoal 32. In addition, although processing of a product is properly used according to a use as shown below, it can also be used as it is without performing processing. Further, as products other than the products 7 ′ and 8 ′, products obtained by attaching acid-treated Ca charcoal 32 to, for example, a nonwoven fabric can be exemplified.

The Ca-introduced chip 30 can be manufactured by performing the process M ₁ surrounded by the two-dot chain line in one factory. Next, this Ca-introduced chip 30 is carbonized in the carbonization furnace 1 of another factory to produce Ca charcoal 31, and the acid-treated Ca charcoal 32 can be produced by bringing the Ca charcoal 31 into contact with the acid solution 3a. .

Similarly, it is possible to produce the Ca charcoal 31 performs step M ₂ surrounded by a chain line in one factory. Next, the acid-treated Ca charcoal 32 can be produced by contacting the Ca charcoal 31 with the acid solution 3a in another factory.

The anion-adsorbing carbon material produced using the calcium-introduced plant or carbide of the present invention is mainly used for the following applications.
(Adsorption of nitrate nitrogen and nitrite nitrogen)
(1) Used for water purification [Phosphorus can also be adsorbed simultaneously by the combination with the Ca charcoal 31 [see FIG. 3 (A)]. It also functions as a microbial carrier. ].
(2) Used for prevention of pollution caused by livestock [Application to areas where manure is likely to flow out, such as livestock manure deposits, composting facilities, etc. [see FIG. 3 (B)]. ].
(3) Used for agriculture to prevent excessive fertilization and contamination [Adsorbs nitrogen that is not used by plants due to excessive fertilization, and then charcoal can be used as a slow-acting fertilizer [see FIG. 3 (C)]. . Also, especially in the event of a fire, nitrogen pollution is severe, such as spraying a large amount of nitrogen fertilizer and amino acids, and it can be applied to such areas. ].
(About fluorine adsorption)
(1) Used for waste water (waste water) treatment [application to final treatment facilities such as semiconductors, glass, and plating plants that are cleaned with hydrofluoric acid [see FIG. 3D]. ].

《Nitrate nitrogen and nitrite nitrogen adsorption test》
〔Test method〕
Prepare 5 nitric acid solutions and 50 ml (milliliter) of nitrous acid solution (standard solution) each having a concentration of nitrate nitrogen and nitrite nitrogen of 50 mg / L (50 ppm),
(1) Charcoal 200 mg (simply called charcoal) used in a comparative example in which the wood chip 2 is carbonized at 700 ° C.
(2) 200 mg of iron chloride charcoal used for the comparative example washed with water after immersing the charcoal obtained by carbonizing the wood chip 2 at 700 ° C. in a 1 mol / L FeCl ₃ solution,
(3) 200 mg of acid-treated charcoal washed with water after immersing charcoal obtained by carbonizing the wood chip 2 at 700 ° C. in a 5 mol / L HCl solution,
(4) 200 mg of acid-treated Ca charcoal 32 (anion-adsorbing carbon material) obtained by immersing the wood chip 2 in 5% by weight of lime water and carbonized at 700 ° C. in a 5 mol / L HCl solution,
(5) Five samples of 200 mg of anion exchange resin used in the comparative example are put in the corresponding standard solutions, respectively, and shaken for 10 hours under the conditions of 200 rpm and 20 ° C., for example, in the nitric acid solution and nitrous acid solution. The concentration of nitrate nitrogen and the concentration of nitrite nitrogen were measured, and the amount of adsorption was calculated.

〔result〕
FIG. 4 represents a comparison of the nitrate nitrogen and nitrite nitrogen adsorption capacities of the above samples.
(1) 700 ° C charcoal charcoal hardly adsorbs nitrate nitrogen and nitrite nitrogen, whereas (2) iron chloride charcoal contains 2.75 mg of nitrate nitrogen and nitrite nitrogen, respectively. / G and 2.35 mg / g were adsorbed. The acid-treated charcoal (3) adsorbed 2.50 mg / g and 2.20 mg / g of nitrate nitrogen and nitrite nitrogen, respectively. The anion exchange resin (5) adsorbed nitrate nitrogen and nitrite nitrogen at 10.80 mg / g and 10.00 mg / g, respectively.

  On the other hand, the acid-treated Ca charcoal 32 of (4) obtained by immersing the wood chip 2 in the lime water H and then carbonizing and subsequently immersing it in the HCl solution is 10.75 mg each of nitrate nitrogen and nitrite nitrogen. / G and 9.80 mg / g were adsorbed, and the adsorption ability was equivalent to or better than the anion exchange resin of (5).

  The mechanism by which the acid-treated Ca charcoal 32 adsorbs nitrate ions, for example, is considered as follows. As shown in FIG. 9 (A), for example, when acid-treated Ca charcoal 32 (anion-adsorbing carbon material) is dipped in nitric acid solution L, it is directly bonded to a functional group on the surface of acid-treated Ca charcoal 32 via calcium ions. The chloride ions [see FIG. 9B] and nitrate ions in the nitric acid solution L are exchanged [see FIG. 9C], and the nitrate ions are adsorbed on the acid-treated Ca charcoal 32 [FIG. 9D]. reference〕. FIG. 9E shows a change when the acid-treated Ca charcoal 32 shown in FIG. 9D is dipped in, for example, a concentrated KCl (or NaCl) solution. That is, the adsorbed nitrate ions can be regenerated by exchanging chloride ions and nitrate ions again with a KCl (or NaCl) solution. Hereinafter, this regeneration test will be described.

《Regeneration test》
〔Test method〕
A sample of the acid-treated Ca charcoal 32 after the nitrate nitrogen adsorption test was washed with a 1 mol / L KCl (or NaCl) solution and further washed with water. Subsequently, the standard solution was changed to prepare 50 ml (milliliter) of a nitric acid solution having a nitrate nitrogen concentration of 50 mg / L, and a first regeneration test of the 200 mg sample washed with water was performed. That is, the sample is put in a nitric acid solution and shaken for 10 hours under conditions of, for example, 200 rpm and 20 ° C., and then the first regeneration test is performed in which the concentration of nitrate nitrogen in the nitric acid solution is measured and the amount of adsorption is calculated. This was performed using the sample.

  Next, the sample used in the first regeneration test was washed with a 1 mol / L KCl (or NaCl) solution and further washed with water. Subsequently, the standard solution was changed to prepare 50 ml (milliliter) of a nitric acid solution having a nitrate nitrogen concentration of 50 mg / L, and a regeneration test of the washed 200 mg of the sample was performed. That is, the sample is placed in 50 ml (milliliter) of a nitric acid solution, shaken for 10 hours under conditions of, for example, 200 rpm and 20 ° C., then the concentration of nitrate nitrogen in the nitric acid solution is measured, and the adsorption amount is calculated. A second regeneration test was performed using the sample. This process was repeated two more times.

〔result〕
Adsorption amount of nitrate nitrogen by acid-treated Ca charcoal 32 First time ... 10.8mg / g
The first regeneration ... 10.6mg / g
Second regeneration: 10.9mg / g
The third regeneration ... 10.7mg / g

From the above, it was found that the acid-treated Ca charcoal 32 used was washed with a concentrated KCl (or NaCl) solution and further washed with water. That is, the acid-treated Ca charcoal (anion adsorbing carbon material) 32 adsorbing nitrate nitrogen (anions) in the nitrate nitrogen adsorption test is washed with a KCl (or NaCl) solution, and further washed with water, so Nitrate nitrogen (anion) adsorbed in the nitrogen adsorption test is removed, and Cl ⁻ is bonded in place of the removed nitrate nitrogen (anion), whereby acid-treated Ca charcoal 32 (anion adsorption carbon material) ) Will play. That is, it was confirmed that the acid-treated Ca charcoal 32 (anion adsorbing carbon material) once used can be used a plurality of times by washing and washing each time after use. The principle of regeneration is the same even when nitrite nitrogen is adsorbed.

<Fluoride ion adsorption test>
〔Test method〕
Prepare 50 ml (milliliter) solution (standard solution) with a fluoride ion concentration of 50 mg / L,
(1) Charcoal 100 mg (simply called charcoal) used in a comparative example in which the wood chip 2 is carbonized at 700 ° C.,
(2) Iron chloride charcoal 100 mg used in the comparative example washed with water after dipping charcoal obtained by carbonizing the wood chip 2 at 700 ° C. in a 1 mol / L FeCl ₃ solution,
(3) After immersing the charcoal obtained by carbonizing the wood chip 2 at 700 ° C. in a 5 mol / L HCl solution, 100 mg of acid-treated charcoal washed with water,
(4) Anion adsorbing carbon material (hereinafter referred to as acid-treated Ca charcoal 32) in which charcoal carbonized at 700 ° C. after dipping the wood chip 2 in 5% by weight of lime water is dipped in a 5 mol / L HCl solution. 100 mg,
(5) Five samples of 100 mg of the anion exchange resin used in the comparative example are put in the corresponding standard solutions, and after shaking for 10 hours under the conditions of, for example, 200 rpm and 20 ° C., the fluoride ion concentration in the solution Was measured, and the amount of adsorption was calculated.

〔result〕
FIG. 5 shows a comparison of fluoride ion adsorption capacities of the above samples.
The 700 ° C. charcoal (1) hardly adsorbs fluoride ions, whereas the iron chloride charcoal (2) adsorbs 7.50 mg / g fluoride ions. The acid-treated charcoal (3) adsorbed 5.00 mg / g fluoride ions. The anion exchange resin of (5) adsorbed 8.50 mg / g fluoride ion.
On the other hand, the acid-treated Ca charcoal 32 of (4) obtained by immersing the wood chip 2 in lime water and then carbonizing and subsequently immersing in the HCl solution adsorbs 19.00 mg / g of fluoride ions, ( The adsorption ability greatly exceeded the anion exchange resin of 5).

《Regeneration test》
〔Test method〕
Next, the sample of acid-treated Ca charcoal 32 after the fluorine adsorption test was washed with 1 mol / L hydrochloric acid (or sulfuric acid), and further washed with water. Subsequently, the standard solution was changed to prepare 50 ml (milliliter) of a solution having a fluoride ion concentration of 50 mg / L, and a first regeneration test of the washed 200 mg sample was performed. That is, the sample is put in the solution, shaken for 10 hours under the conditions of, for example, 200 rpm and 20 ° C., then the fluoride ion concentration in the solution is measured, and the first regeneration test for calculating the adsorption amount is performed. A sample was used.
Next, the sample used in the first regeneration test was washed with 1 mol / L hydrochloric acid (or sulfuric acid) and further washed with water. Subsequently, the standard solution was replaced to prepare 50 ml (milliliter) of the solution having a fluoride ion concentration of 50 mg / L, and a regeneration test of the washed 200 mg of the sample was performed. That is, the sample is put in 50 ml (milliliter) of the solution, shaken for 10 hours under the conditions of, for example, 200 rpm and 20 ° C., and then the fluoride ion concentration in the solution is measured to calculate the adsorption amount. The regeneration test was performed using the sample. This process was repeated two more times.

〔result〕
Adsorption amount of fluoride ion concentration by acid-treated Ca charcoal 32 First time ... 18.7mg / g
The first regeneration ... 18.2mg / g
Second regeneration ... 18.9mg / g
The third regeneration ... 18.6mg / g
From the above, it was found that the acid-treated Ca charcoal 32 used was regenerated by washing with concentrated hydrochloric acid (or sulfuric acid) and further washing with water. That is, the acid-treated Ca charcoal 32 (anion adsorbing carbon material) adsorbing fluoride ions (anions) in the fluorine adsorption test is washed with hydrochloric acid (or sulfuric acid), and further washed with water, so that it is adsorbed in the fluorine adsorption test. Fluoride ions (anions) are removed, and instead of the removed fluoride ions (anions), Cl ⁻ (or SO ₄ ⁻ ) is bonded to the acid-treated Ca charcoal 32 (anion adsorption). It was found that the carbon material was regenerated. That is, it was confirmed that the acid-treated Ca charcoal 32 (anion adsorbing carbon material) once used can be used a plurality of times by washing and washing each time after use.

  In the embodiment described above, the wood material 2 subjected to the calcium introduction treatment is used, but the wood material 2 subjected to the metal chloride introduction treatment may be used. Hereinafter, this will be described as a second embodiment with reference to FIGS. 10 and 11. FIG.

First, FIG. 10 schematically shows an example of an apparatus for producing a carbon material 90 which is a metal compound charcoal as another example of an anion adsorbing carbon material. In this figure, the reference numerals shown in FIG. The same reference numerals are the same. Then, as shown in FIG. 10, the wood chip (wood material) 2 is sent to a treatment tank 92 containing a metal chloride solution 91 (CaCl ₂ solution in this embodiment) having an appropriate concentration, and this treatment tank. In 92, the metal chloride (CaCl _{2 in} this embodiment) is introduced into the wood chip 2 to form the metal chloride introduction chip 93. Reference numeral 94 denotes a stirring blade provided in the processing tank 92, which is rotationally driven by a motor (not shown), and is used when stirring the liquid or the like in the processing tank 92. Here, in order to improve the anion adsorption ability, it is preferable to add Ca (OH) ₂ slightly to the metal chloride solution.

  The metal chloride introduction chip 93 obtained as described above is dried by the dryer 12 and then sent to the carbonization furnace 1 to be carbonized. The dryer 12 is configured to use exhaust heat discharged from the carbonization furnace 1 for the drying process.

  The metal chloride introduction chip 93 is supplied into the carbonization furnace main body 95 through the introduction portion 95a, and is carbonized by heating at an appropriate temperature (described later) and an appropriate time (described later). 90a is discharged from the discharge unit 95b to the outside of the carbonization furnace main body 95.

  Thereafter, the metal chloride charcoal 90a is sent to a treatment tank 97 containing water or an HCl solution (hydrochloric acid) 96, and the metal chloride charcoal 90a is brought into contact with the water or the HCl solution 96 (immersion) in the treatment tank 97. Processing is performed, and the carbon material 90 is obtained. Reference numeral 98 denotes a stirring blade provided in the processing tank 97, which is rotationally driven by a motor (not shown) and is used when stirring the liquid or the like in the processing tank 97. After the contact treatment with the acid, the contact treatment with water may be performed, and vice versa.

  Subsequently, the carbon material 90 obtained as described above is sent to the drier 6 and dried, and then formed into granules (pellets) 7 ′ and finer powders 8 ′ having appropriate diameters. The The dryer 6 is configured to use the exhaust heat discharged from the carbonization furnace 1 for the drying process.

  Next, an example of a procedure for obtaining the carbon material 90 from the wood material 2 using the apparatus shown in FIG. 10 will be described in detail with reference to FIGS. 10 and 11. First, a wood chip 2 in which conifers such as birch and cedar are chipped into an appropriate size of 10 mm or less is prepared (step T1).

Subsequently, the wood chip 2 is immersed in a CaCl ₂ solution 91 adjusted to 1 to 20% by weight in the treatment tank 92 for 3 hours or more, for example. It is preferable to rotate the stirring blade 94 during the immersion of the wood chip 2. As a result, the CaCl ₂ solution 91 can permeate into the wood chip 2, and a metal chloride introduction chip 93 in which Ca ions and Cl ions are introduced into the wood chip 2 is obtained (step T2).

  Then, the metal chloride introduction chip 93 is sent to the dryer 12 to be dried (step T3).

  Thereafter, the metal chloride introduction chip 93 is supplied to the carbonization furnace main body 95 of the carbonization furnace 1 and heated and carbonized for about 1 hour in a temperature range of 400 ° C. to 1000 ° C. (700 ° C. in this embodiment). (Step T4). Thereby, metal chloride charcoal 90a is obtained.

The metal chloride charcoal 90a is supplied to the treatment tank 97 and immersed in an HCl solution 96 adjusted to 0.01 mol / L to 11 mol / L (for example, 5 mol / L) in the treatment tank 97 (step T5). ). In this case, it is preferable to rotate the stirring blade 98, whereby it is possible to remove excess metal chloride (CaCl ₂ ) crystals remaining in the metal chloride charcoal 90a and further add chloride ions. The desired carbon material 90 can be obtained.

  And the carbon material 90 after the said immersion process is generally dried in the dryer 6 (step T6). In this case, the carbon material 90 may be sent to the dryer 6 as it is, but may be neutralized by immersing it in an appropriate alkaline solution, or may be washed with water after the neutralization. When the carbon material 90 is used in a wet state, the drying process may not be performed.

  The carbon material 90 after the drying treatment can be used in the form of a chip. In this embodiment, an appropriate diameter granule (pellet) 7 ′ or finer powder is used in this embodiment. 8 '(step T7).

  In addition, the said carbon material 90 is not restricted to what is manufactured by performing all from the said step T1 to step T7 in the same factory. For example, when manufacturing up to a certain step among the steps T1 to T7 in other factories or the like, the carbon material 90 may be manufactured starting from an intermediate step.

In the second embodiment, as the metal chloride, CaCl _{2 from} which the highest performance anion-adsorbing carbon material is obtained is exemplified, but BaCl ₂ , MnCl ₂ or the like may be used.

  In the second embodiment, the contact treatment with respect to the HCl solution 96 of the carbon material 90 is performed in the treatment tank 97, but water may be used instead of the HCl solution 96. In this case, chloride ions are not added, and only the excess metal chloride crystals remaining in the metal chloride charcoal 90a are removed.

  Furthermore, in the above-described embodiment, the metal chloride introduction chip 93 is carbonized in the carbonization furnace 1 to obtain the metal chloride charcoal 90a, and then sent to the treatment tank 97 to obtain the carbon material 90. The metal chloride charcoal 90a can be used as it is as the carbon material 90 without being sent to the treatment tank 97. In this case, since the metal chloride charcoal 90a does not need to be sent to the dryer 14, the steps T5 and T6 are omitted. Moreover, in this case, as a manufacturing method of the carbon material 90, the process may be terminated in steps T1 to T4, and then step T7 may be performed.

  Next, a test conducted for examining the adsorption performance of nitrate nitrogen and nitrite nitrogen of the carbon material 90 of the second embodiment will be described. The test method and test results for the adsorption performance of nitrate nitrogen and nitrite nitrogen will be described as follows.

First, two sets of 200 mg each were prepared for a total of seven samples (1) to (7) shown below. That is,
(1) Charcoal obtained by heating and carbonizing wood chip 2 at 700 ° C. for 1 hour (2) Heating and carbonizing wood chip 2 at 700 ° C. for 1 hour, and then dipping in 1 mol / L FeCl ₃ solution Iron chloride charcoal obtained by washing with water (3) Anion exchange resin (4) BaCl ₂ charcoal obtained by dipping the wood chip 2 in a 10% by weight BaCl ₂ solution and then carbonizing it by heating at 700 ° C. for 1 hour (5) The wood chip 2 is immersed in a 10 wt% BaCl ₂ solution, heated at 700 ° C. for 1 hour to be carbonized, and then immersed in a 5 mol / L HCl solution to obtain an HCl-treated BaCl ₂ charcoal ( 6) CaCl ₂ charcoal obtained by dipping the wood chip 2 in a 10 wt% CaCl ₂ solution and then carbonizing it by heating at 700 ° C. for 1 hour. (7) The wood chip 2 was dipped in a 10 wt% CaCl ₂ solution. After 1 hour at 700 ° C Two sets of a total of seven samples of HCl-treated CaCl ₂ charcoal obtained by heating and carbonizing and then dipping in a 5 mol / L HCl solution were prepared. The samples (4) to (7) correspond to the carbon material 90, and the samples (1) to (3) are for comparison with the carbon material 90.

  Then, each sample of one set is individually put into 50 mL (first standard solution) of a nitrate nitrogen solution having a nitrate nitrogen concentration of 50 mg / L (50 ppm), and each sample of the other set is The nitrite nitrogen concentration was individually added to 50 mL (second standard solution) of nitrite nitrogen solution having a concentration of 50 mg / L (50 ppm). Then, after shaking for 10 hours under the conditions of 200 rpm and 20 ° C., the concentration of nitrate nitrogen in the first standard solution and the concentration of nitrite nitrogen in the second standard solution were measured, respectively. The amount of adsorbed nitrogen and nitrite nitrogen was calculated.

FIG. 16 shows a comparison result of nitrate nitrogen adsorption ability and nitrite nitrogen adsorption ability of each sample obtained by the above test. In this figure, the amount of nitrate nitrogen and nitrite nitrogen adsorption of each sample is shown as a pair of bar graphs. The left bar graph shows the nitrate nitrogen adsorption amount, and the right bar graph shows the nitrite nitrogen adsorption amount. ing. From the results shown in this figure, it can be seen that all the samples of the present invention have high nitrate nitrogen adsorption ability and nitrite nitrogen adsorption ability. Further, the adsorption amounts of nitrate nitrogen and nitrite nitrogen of (4) BaCl ₂ charcoal and (5) HCl-treated BaCl ₂ charcoal were compared, and (6) CaCl ₂ charcoal and (7) HCl adsorbed. In order to further increase the nitrate nitrogen / nitrite nitrogen adsorption capacity of the carbon material 90 by comparing the adsorption amounts of nitrate nitrogen and nitrite nitrogen of the treated CaCl ₂ charcoal, the carbon material 90 is added to the HCl solution. It can be seen that it is better to perform a dipping treatment (HCl treatment). However, a carbon material 90 having sufficiently high nitrate nitrogen / nitrite nitrogen adsorption ability can be obtained without performing HCl treatment. In this case, the cost is low because the contact treatment of the HCl solution is not performed. The carbon material 90 can be manufactured.

Here, the carbon material 90 adsorbs nitrate ions, for example, when the carbon material (CaCl ₂ charcoal) 1 is immersed in the nitric acid solution 99 as shown in FIG. Cl ions (see (B) in the same figure) directly bonded to the group via Ca ions or NO ₃ ions in the nitric acid solution 99 are exchanged (see (C) in the same figure), and the NO ₃ ions are converted into the carbon material 90. It is thought that this is because it is adsorbed on the surface (see FIG. 4D).

FIG. 15E shows a carbon material 90 that has adsorbed NO ₃ ions and has reached the state shown in FIG. 15D. A high-concentration chloride solution (for example, a metal chloride solution of KCl or NaCl, or The state after being immersed in HCl solution) is shown. That is, NO ₃ ions adsorbed on the carbon material 90 are exchanged with Cl ions by the chloride solution, whereby the carbon material 90 is regenerated, and anions such as NO ₃ ions can be adsorbed. That is, the carbon material 90 according to the second embodiment is not limited to a carbon material 90 that is always newly obtained by the above-described manufacturing method, but is adsorbed from the carbon material 90 that is obtained by the manufacturing method and adsorbs anions (for example, NO ₃ ions). Anion (NO ₃ ion) is removed, and an anion (in this embodiment, Cl ion) capable of ion exchange with the next anion (for example, NO ₃ ion) to be adsorbed is removed. What was obtained by combining instead of (NO ₃ ion) (that is, regenerated) may be used. When sulfuric acid is used instead of the chloride solution, NO ₃ ions are ion-exchanged with SO ₄ ions instead of the Cl ions.

  That is, the metal chloride introduction chip 93 is an example of a metal chloride introduction plant used in the production of the anion-adsorbing carbon material 90 according to claim 5, and in FIG. An example of the manufacturing method of the metal chloride introduction | transduction plant 93 used for manufacture of the anion adsorption carbon material 90 in Claim 6 is shown. However, the method for producing the metal chloride-introduced plant 93 of the present invention is not limited to using the dryer 12, and the drying step using the dryer 12 can be omitted.

  The metal chloride charcoal 90a is an example of a carbide used for the production of the anion adsorbing carbon material 90 in claim 7. In FIGS. 10 and 11, the process N2 surrounded by a two-dot chain line is an anion in claim 8. An example of the manufacturing method of the carbide | carbonized_material 90a used for manufacture of the ion adsorption carbon material 90 is shown.

Next, the test conducted to examine the influence of the concentration of the metal chloride solution (CaCl ₂ solution) 91 in which the wood chip 2 is immersed in Step T2 on the anion adsorption ability of the carbon material 90 after manufacture will be described. . In the above test, the carbon material 90 obtained by immersing the wood chip 2 in the CaCl ₂ solution 91, carbonizing by heating at 700 ° C. for 1 hour, and washing with water was used. The concentration of nitrate nitrogen was 50 mg / L (50 ppm). Was added to 50 mL (standard solution) of nitrate nitrogen solution, and the adsorption ability of nitrate nitrogen of the carbon material 90 was examined. As the CaCl ₂ solution 91, the concentration was 1 wt%, 3 wt%, 5 wt%. %, 7%, 10%, 12%, 14%, 17% and 20% by weight were used. For comparison, adsorption of nitrate nitrogen of the carbon material 90 obtained by immersing the wood chip 2 in a 10% by weight CaCl ₂ solution 91, carbonizing by heating at 700 ° C. for 1 hour, and treating with HCl. I also examined Noh. The results of the above test are shown in FIG.

As is clear from the results shown in FIG. 17, the anion adsorption capacity of the carbon material 90 does not increase in proportion to the concentration of the CaCl ₂ solution, and may be about 10% by weight from the viewpoint of cost. Most preferred. Also, from the results shown in FIG. 17, it can be seen that it is better to treat the carbon material 90 with HCl in order to further enhance the anion adsorption ability of the carbon material 90.

  Next, the carbon material 90 of the second embodiment used for the adsorption of nitrate nitrogen was regenerated with a KCl (or NaCl) solution, and the regeneration was performed to examine the nitrate nitrogen adsorption ability of the regenerated carbon material 90. The test will be described.

First, as the carbon material 90, 200 mg of CaCl ₂ charcoal obtained by immersing the wood chip 2 in a 10 wt% CaCl ₂ solution and heating and carbonizing at 700 ° C. for 1 hour was prepared. Then, this CaCl ₂ charcoal was put into 50 mL (standard solution) of a nitrate nitrogen solution having a nitrate nitrogen concentration of 50 mg / L (50 ppm), shaken at 200 rpm and 20 ° C. for 10 hours, The concentration of nitrate nitrogen in the standard solution was measured, and the amount of nitrate nitrogen adsorbed by the CaCl ₂ charcoal was calculated (first time).

Subsequently, the CaCl ₂ charcoal was washed with a 1 mol / L KCl (or NaCl) solution and further regenerated by washing with water. Thereafter, the regenerated CaCl ₂ charcoal is added to a newly prepared standard solution (that is, a nitrate nitrogen solution 50 mL having a nitrate nitrogen concentration of 50 mg / L) and shaken for 10 hours under the conditions of 200 rpm and 20 ° C. Thereafter, the concentration of nitrate nitrogen in the standard solution was measured, and the amount of nitrate nitrogen adsorbed by the CaCl ₂ charcoal was calculated. Then, the process from the reproduction of the CaCl ₂ charcoal up to the calculation of the amount of adsorbed nitrate nitrogen was carried out three times (reproducing first time - third time).

As a result of the regeneration test, that is, the adsorption amount of nitrate nitrogen by CaCl ₂ charcoal is
First time: 9.5mg / g
The first regeneration ... 9.0mg / g
Second regeneration: 9.1 mg / g
The third regeneration ... 8.8mg / g
Met. From the above, it was confirmed that the carbon material 90 (CaCl ₂ charcoal) used for the adsorption of nitrate nitrogen was regenerated by washing with a concentrated KCl (or NaCl) solution and further with water. This is because the nitrate nitrogen is removed from the CaCl ₂ charcoal by washing the CaCl ₂ charcoal adsorbing the nitrate nitrogen with a KCl (or NaCl) solution and then washing with water. This is thought to be because Cl ^- is bonded to a functional group. Further, from the result of the regeneration test, the carbon material 90 (CaCl ₂ charcoal) can be used multiple times for adsorption of nitrate nitrogen if it is regenerated by washing with KCl (or NaCl) solution and washing with water. It was also confirmed that it could be done. Even when the carbon material 90 (CaCl ₂ charcoal) is used for adsorption of nitrite nitrogen, the principle of regeneration is the same.

Next, as the carbon material 90 of the second embodiment, the wood chip 2 is immersed in a 10 wt% CaCl ₂ solution, heated at 700 ° C. for 1 hour to be carbonized, and then immersed in a 5 mol / L HCl solution. using HCl treatment CaCl ₂ charcoal was collected using, for the HCl process CaCl ₂ charcoal shows the results of similarly regeneration test as described above.

As a result of the regeneration test, that is, the adsorption amount of nitrate nitrogen by the HCl-treated CaCl ₂ charcoal,
First time ... 11.0mg / g
The first regeneration ... 11.0mg / g
Second regeneration: 10.8mg / g
The third regeneration ... 10.8mg / g
Met. From the above, carbon material 90 (HCl-treated CaCl ₂ charcoal) obtained by immersing in HCl solution after carbonization is also washed with concentrated KCl (or NaCl) solution after use for adsorption of nitrate nitrogen, Regeneration was confirmed by washing with water. Further, the nitrate nitrogen adsorption ability of the HCl-treated CaCl ₂ charcoal improved by the immersion treatment in the HCl solution is obtained by repeatedly regenerating the HCl-treated CaCl ₂ charcoal by washing with KCl (or NaCl) solution and washing with water. Has also been confirmed to remain (still improved).

  Next, a test conducted for examining the fluoride ion adsorption performance of the carbon material 90 of the second embodiment will be described. First, in order to perform this test, 50 mg each of a total of seven samples (1) to (7) used in the above-described adsorption performance test for nitrate nitrogen and nitrite nitrogen were prepared. Each sample was individually added to 50 mL (standard solution) of a solution having a fluoride ion concentration of 50 mg / L (50 ppm), shaken at 200 rpm and 20 ° C. for 10 hours, and then subjected to the fluoride in the standard solution. The concentration of fluoride ion was measured, and the amount of fluoride ion adsorption by each sample was calculated.

FIG. 18 shows a comparison result of fluoride ion adsorption ability of each sample obtained by the above test. From the results shown in this figure, it can be seen that all the samples of the present invention have high fluoride ion adsorption ability. Furthermore, the adsorption amounts of fluoride ions of (4) BaCl ₂ charcoal and (5) HCl-treated BaCl ₂ charcoal were compared, and (6) CaCl ₂ charcoal and (7) HCl-treated CaCl ₂ charcoal were compared. By comparing the adsorption amounts of fluoride ions, it is understood that it is better to perform a treatment (HCl treatment) in which the carbon material 90 is immersed in an HCl solution in order to further enhance the fluoride ion adsorption ability of the carbon material 90. . However, a carbon material 90 having a sufficiently high fluoride ion adsorption ability can be obtained without performing the HCl treatment. In this case, the carbon material 90 is manufactured at a low cost because the contact treatment with the HCl solution is not performed. can do.

  Next, a regeneration test performed to regenerate the carbon material 90 used for the adsorption of fluoride ions with hydrochloric acid (or sulfuric acid) and examine the fluoride ion adsorption ability of the regenerated carbon material 90 will be described.

First, as the carbon material 90, 200 mg of CaCl ₂ charcoal obtained by immersing the wood chip 2 in a 10 wt% CaCl ₂ solution and heating and carbonizing at 700 ° C. for 1 hour was prepared. Then, this CaCl ₂ charcoal was put into 50 mL (standard solution) of a solution having a fluoride ion concentration of 50 mg / L (50 ppm), shaken at 200 rpm and 20 ° C. for 10 hours, and then in the standard solution. The concentration of fluoride ions was measured, and the amount of fluoride ions adsorbed by the CaCl ₂ charcoal was calculated (first time).

Subsequently, the CaCl ₂ charcoal was washed with 1 mol / L hydrochloric acid (or sulfuric acid) and further regenerated by washing with water. Thereafter, the regenerated CaCl ₂ charcoal was added to a newly prepared standard solution (that is, 50 mL of a solution having a fluoride ion concentration of 50 mg / L), shaken at 200 rpm and 20 ° C. for 10 hours, The concentration of fluoride ions in the standard solution was measured, and the adsorption amount of fluoride ions by the CaCl ₂ charcoal was calculated. Then, the processing up to the calculation of the adsorption amount of fluoride ions from the reproduction of the CaCl ₂ charcoal was carried out three times (reproducing first time - third time).

As a result of the regeneration test, that is, the adsorption amount of fluoride ions by CaCl ₂ charcoal,
First time ... 22.5mg / g
The first reproduction… 22.4mg / g
Second regeneration: 21.7 mg / g
The third regeneration ... 21.9mg / g
Met. From the above, it was confirmed that the carbon material 90 (CaCl ₂ charcoal) used for adsorption of fluoride ions was regenerated by washing with concentrated hydrochloric acid (or sulfuric acid) and further with water. This is because the fluoride ions are removed from the CaCl ₂ charcoal by washing the CaCl ₂ charcoal on which the fluoride ions have been adsorbed with hydrochloric acid (or sulfuric acid) and then washing with water, and instead of the removed fluoride ions, Cl ^- (Or SO ₄ ^2- ) is considered to be bonded to the functional group. Further, from the result of the regeneration test, the carbon material 90 (CaCl ₂ charcoal) is used for adsorption of fluoride ions multiple times if it is regenerated by washing with hydrochloric acid (or sulfuric acid) and washing with water. It was also confirmed that it was possible.

Next, as the carbon material 90 of the second embodiment, the wood chip 2 is immersed in a 10 wt% CaCl ₂ solution, heated at 700 ° C. for 1 hour to be carbonized, and then immersed in a 5 mol / L HCl solution. using HCl treatment CaCl ₂ charcoal was collected using, for the HCl process CaCl ₂ charcoal shows the results of similarly regeneration test as described above.

As a result of the regeneration test, that is, the adsorption amount of fluoride ions by the HCl-treated CaCl ₂ charcoal,
First time… 32.0mg / g
First reproduction: 31.5mg / g
Second regeneration: 31.4mg / g
The third regeneration ... 31.2mg / g
Met. From the above, the carbon material 90 (HCl-treated CaCl ₂ charcoal) obtained by immersing in an HCl solution after carbonization is also washed with a hydrochloric acid (or sulfuric acid) solution after being used for adsorption of fluoride ions, and further washed with water. By doing so, it was confirmed that it was reproduced. Further, the fluoride ion adsorption ability of the HCl-treated CaCl ₂ charcoal improved by the immersion treatment in the HCl solution can be obtained by repeatedly regenerating the HCl-treated CaCl ₂ charcoal by washing with hydrochloric acid (or sulfuric acid) and washing with water. It was confirmed that it persisted (it remained improved).

  In the first embodiment, the wood material 2 is subjected to calcium introduction treatment, and in the second embodiment, the wood material 2 is subjected to metal chloride introduction treatment. An anion adsorbing carbon material may be produced using an introduced plant into which both metal chlorides have been introduced. Specifically, it is conceivable to use a solution containing calcium ions and metal chloride (for example, calcium chloride solution) as the solution H (or metal chloride solution 91) containing calcium ions.

1 is an overall configuration explanatory diagram for explaining an embodiment of the present invention. It is a figure which shows the manufacturing process in the said embodiment. It is a figure which shows the example of application of an anion adsorption | suction carbon material. It is a figure which shows each adsorption amount in the adsorption test of nitrate nitrogen and nitrite nitrogen of an anion adsorption carbon material. It is a figure which shows each adsorption amount in the adsorption test of the fluoride ion of an anion adsorption carbon material. It is a figure which shows the process of making the solution containing calcium ion contact a raw material. It is a figure which shows the process of carbonizing a calcium introduction plant. It is a figure which shows the process of making an acid solution contact Ca introduction charcoal. It is a figure which shows the mechanism of nitrate ion adsorption | suction by an anion adsorption carbon material. It is a whole block explanatory diagram for demonstrating 2nd Example of this invention. It is a figure which shows the manufacturing process in 2nd Example. (A)-(C) is a figure which shows the detail of the process of step T2 in FIG. (A)-(C) are the figures which show the detail of the process of step T4 in FIG. (A)-(C) are the figures which show the detail of the process of step T5 in FIG. (A)-(D) is a figure which shows the detail of nitrate ion adsorption | suction in 2nd Example, (E) is a figure which shows the carbon material after reproduction | regeneration. It is a graph which shows the comparison result of the adsorption amount of nitrate nitrogen and nitrite nitrogen of the carbon material of 2nd Example, and a comparison material. It is a graph showing the adsorption amount of nitrate nitrogen of the carbon material obtained by CaCl ₂ solution carbon materials and HCl treatment were prepared by varying the concentration of the step T2. It is a graph which shows the comparison result of the adsorption amount of the metal chloride charcoal of 2nd Example, and the fluoride ion of a comparative material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carbonization means 2 Raw material consisting of plant 30 Calcium-introduced plant 31 Carbide 32 Anion adsorption carbon material H Solution containing calcium ion

Claims (8)

The functional group formed in the micropores walls having carbide carbonized raw material consisting of plants, either directly or through a calcium anion adsorbing carbon material bound anions capable of anion and the ion exchange adsorption target A calcium-introduced plant used for the production of an anion-adsorbing carbon material, which is a calcium-introduced plant used for the production of the anion, and is made to contact a solution containing calcium ions before carbonizing the raw material comprising the plant. The functional group formed in the micropores walls having carbide carbonized raw material consisting of plants, either directly or through a calcium anion adsorbing carbon material bound anions capable of anion and the ion exchange adsorption target Calcium-introduced plant used for the production of anion-adsorbing carbon material, which is a method for producing a calcium-introduced plant used for the production of an anion-adsorbing carbon material, characterized by contacting a solution containing calcium ions before carbonizing a plant-derived material Manufacturing method. The functional group formed in the micropores walls having carbide carbonized raw material consisting of plants, either directly or through a calcium anion adsorbing carbon material bound anions capable of anion and the ion exchange adsorption target A carbide used for the production of an anion-adsorbing carbon material obtained by carbonizing a calcium-introduced plant obtained by contacting a raw material comprising a plant with a solution containing calcium ions. The functional group formed in the micropores walls having carbide carbonized raw material consisting of plants, either directly or through a calcium anion adsorbing carbon material bound anions capable of anion and the ion exchange adsorption target A method for producing a carbide used in the production of an anion-adsorbing carbon material, characterized by carbonizing a calcium-introduced plant obtained by contacting a raw material comprising a plant with a solution containing calcium ions. Production method. The functional group formed in the micropores walls having carbide carbonized raw material consisting of plants, either directly or through a metal, an anion adsorbing carbon bound chloride ions capable anion and the ion exchange adsorption target A metal chloride-introduced plant used for the production of anion-adsorbing carbon materials, which is a metal chloride-introduced plant used for the production of materials, and is brought into contact with a solution containing the metal chloride before carbonizing the raw material comprising the plant . The functional group formed in the micropores walls having carbide carbonized raw material consisting of plants, either directly or through a metal, an anion adsorbing carbon bound chloride ions capable anion and the ion exchange adsorption target A method for producing a metal chloride-introduced plant used in the production of a material, which is used for producing an anion-adsorbing carbon material characterized by contacting a solution containing a metal chloride before carbonizing a plant raw material. A method for producing a metal chloride-introduced plant. The functional group formed in the micropores walls having carbide carbonized raw material consisting of plants, either directly or through a metal, an anion adsorbing carbon bound chloride ions capable anion and the ion exchange adsorption target A carbide used for manufacturing an anion-adsorbing carbon material, which is a carbide used for manufacturing a material and carbonized a metal chloride-introduced plant obtained by bringing a solution containing a metal chloride into contact with a plant raw material. The functional group formed in the micropores walls having carbide carbonized raw material consisting of plants, either directly or through a metal, an anion adsorbing carbon bound chloride ions capable anion and the ion exchange adsorption target A method for producing a carbide used in the production of a material, characterized by carbonizing a metal chloride-introduced plant obtained by contacting a solution containing a metal chloride with a raw material consisting of a plant, for producing an anion-adsorbing carbon material Manufacturing method of carbide used.