JP5582141B2 - Treatment agent, method for producing the same, and treatment method - Google Patents

Description

The present invention relates to a treatment agent, a production method thereof, and a treatment method.

Fluorine is the wastewater discharged from the electrolytic refining process of aluminum, the manufacturing process of phosphate fertilizer, the pickling process of stainless steel, etc., the cleaning process of electrical parts such as silicon, the sewage sewage sewage, the coal-fired flue gas desulfurization effluent However, the drainage standard has already been set, and the removal process is carried out to clear the standard value.

Currently, fluorine treatment methods that have been put into practical use include a method in which a calcium salt is added to form poorly soluble calcium fluoride (CaF ₂ ) and precipitated and separated, and an aluminum salt is added in an aluminum hydroxide (Al ( A method of coprecipitation with OH) ₃ ) and separation, or a method of combining a coagulation precipitation method using a calcium salt and a coagulation precipitation method using an aluminum salt are common (see, for example, Non-Patent Document 1).

On the other hand, effluent standards and environmental standards for fluorine have become stricter recently, and it has become necessary to treat wastewater containing fluorine at a high level. However, in conventional coagulation and precipitation methods using calcium salts, the standard is 8 mg / L or less. It was very difficult to do.

In addition, in the coprecipitation method using aluminum hydroxide, a technique of adding a sulfate band (Al ₂ (SO ₄ ) ₃ 16H ₂ O) as a flocculant is known (for example, see Patent Document 1). However, in these conventional techniques, it is necessary to separate and treat the sludge composed of coprecipitate equal to or more than the sulfuric acid band to be added and the treated sludge so that fluorine does not elute the separated sludge. In addition, complicated processing processes such as landfilling were necessary.

In order to solve these conventional techniques, as a fluorination treatment agent that can satisfy the wastewater standard, recently, a method of fixing and removing fluorine in wastewater as fluoroapatite using a hardly soluble phosphate is disclosed. (For example, refer to Patent Documents 2 and 3.)

According to Patent Document 2, it is said that the fluorine concentration in the waste water can be reduced to 0.8 mg / L or less only by adding phosphates and / or phosphoric acid compounds.

However, the treatment method of waste water containing fluorine generally performed using phosphates and / or phosphate compounds is a ratio in which phosphates and / or phosphate compounds and fluorine are determined from their chemical composition. It is characterized by the formation of a complex salt with a maximum of the stoichiometric amount of fluorine. For this purpose, phosphates and / or phosphate compounds are used in a fine powder. There is a need to.

Examples of the treatment process for bringing the fine powdered phosphates and / or phosphate compound into contact with the wastewater containing fluorine include examples using a dispersion type contact tank (see, for example, Patent Documents 4 and 5). .)

Further, as a simpler processing method, a process of removing fluorine by circulating fluorine-containing wastewater in a packed bed in which the fine powdered phosphates and / or phosphate compounds are densely packed is generally used. Is.

By the way, as a technique for suppressing the elution of fluorine, as a treatment agent for insolubilizing fluorine in fluorine-contaminated soil, powder particles of calcium hydrogen phosphate dihydrate are suspended in water, and the particle surface Has been disclosed (see, for example, Patent Document 6). Moreover, as a method for treating gypsum to reduce the elution of contained fluorine, hydrogen phosphate in an amount of 1 to 5 parts by mass per 100 parts by mass of calcium sulfate dihydrate in gypsum A method of recovering after curing in water for a required period in the presence of calcium dihydrate is disclosed (for example, see Patent Document 7).

JP 2005-324137 A Japanese Patent No. 3504248 JP 2004-358309 A JP 2004-122113 A JP 2006-305555 A JP 2007-216156 A JP 2008-297172 A

Hiroyuki Asada and Yoshihiro Eto, “Fluorine and Boron Treatment Technology”, Environmental Technology, 2000, vol. 29, no. 4, p. 283-289

However, as in Patent Documents 4 and 5, the method of dispersing fine powdered phosphates and / or phosphate compounds in the contact tank is performed while reacting phosphates and / or phosphate compounds with fluorine. Although they are characterized by suppressing their outflow, in order to fix fluorine to a stoichiometric ratio with respect to phosphates and / or phosphate compounds, phosphates and / or phosphate compounds are used as much as possible. It is necessary to use after pulverizing, and such a fine powder may reduce the processing speed.

In addition, as described above, a method of removing fluorine by flowing fluorine-containing wastewater through a packed bed in which fine powdered phosphates and / or phosphate compounds are densely packed is used to fill phosphates The finer the phosphoric acid compound and / or the lower the water permeability of the packed bed, the greater the pressure loss, so the problem that the packed bed must be pressure resistant, and fine powder Therefore, there is a problem that it is suspended in water and is difficult to separate from water.

On the contrary, when the phosphates and / or phosphate compounds to be packed are granulated and the particle size is increased to form a packed bed with increased water permeability, the phosphates and / or phosphate compounds are formed on the surface of the particles. Since it reacts with fluorine, there has been a problem that the amount of fluorine removed per unit weight of phosphates and / or phosphate compounds is reduced.

An object of the present invention is to solve the problems in the conventional methods as described above, and to provide a treatment agent and a treatment method that can easily and efficiently remove fluorine in waste water.

The present invention includes calcium hydrogen phosphate dihydrate (A) and particles (B), wherein the calcium hydrogen phosphate dihydrate (A) is supported on the particles (B). It is a processing agent.

The present invention is also a method for producing the above-mentioned treatment agent, which comprises the step of mixing the calcium hydrogen phosphate dihydrate (A) and the particles (B) using an inclined cylinder type gravity mixer. It is also a manufacturing method.

This invention is also a processing method including the process of making the said process agent and the process target water containing a fluorine contact, and removing the fluorine in this process target water.

The present invention is also a treatment method including a step of mixing the treatment agent with soil containing fluorine to insolubilize fluorine in the soil.
The present invention is described in detail below.

The present invention is a treatment agent containing calcium hydrogen phosphate dihydrate (A) and particles (B) (except for particles of calcium hydrogen phosphate dihydrate (A)). By carrying the calcium hydrogen phosphate dihydrate (A) on the particles (B) and allowing the treatment agent water of the present invention to permeate the water to be treated containing fluorine, powder hydrogen phosphate in the long term Calcium dihydrate (A) does not substantially flow out, and is excellent in water permeability over a long period of time, and the fluorine concentration in the treated water can be 0.8 mg / L or less over a long period of time. Here, the term “supporting” refers to supporting the particles (B) as a carrier to carry the calcium hydrogen phosphate dihydrate (A).

The treatment agent of the present invention is obtained by mixing powdered calcium hydrogen phosphate dihydrate (A) and particles (B), and the calcium hydrogen phosphate dihydrate (A) is converted into particles (B Therefore, since the particle size is large, it is difficult to form lumps (aggregates) and has excellent water permeability. Moreover, by carrying | supporting calcium hydrogenphosphate dihydrate (A) to particle | grains (B), it becomes a processing agent which is hard to disperse | distribute and becomes excellent in handleability. Furthermore, since the particle size of the calcium hydrogen phosphate dihydrate (A) itself is maintained in a small state (fine powder state), the amount of fluorine removal is sufficient.

Since the treatment agent of the present invention contains calcium hydrogen phosphate dihydrate (A), fluorine in water or the like can be removed by bringing water or the like into contact with the treatment agent. Moreover, when mixed with fluorine-contaminated soil, fluorine in the fluorine-contaminated soil can be insolubilized as fluorapatite, and elution of fluorine from the soil can be suppressed. Calcium hydrogen phosphate dihydrate (A) exhibits a particularly excellent effect on insolubilizing fluorine in fluorine-contaminated soil as fluorine apatite. For example, calcium phosphate (Ca ₃ (PO ₄ ) ₂ ) has an effect of insolubilizing fluorine in fluorine-contaminated soil, but is inferior to calcium hydrogen phosphate dihydrate (A).

Fluoroapatite itself is the main component of natural phosphate ore, and other organic substances or heavy metals may not be used, and according to the treatment agent of the present invention, without causing secondary environmental pollution, The amount of fluorine eluted from fluorine-contaminated soil can be reduced to 0.8 mg / L or less of the soil environment standard with simple operations economically and reliably.

It is preferable that the said processing agent is 1-100 mass parts of calcium hydrogenphosphate dihydrate (A) with respect to 100 mass parts of particle | grains (B). By setting to the said range, calcium hydrogenphosphate dihydrate (A) is efficiently carry | supported by particle | grain (B), and it becomes a processing agent which is more excellent in water permeability and fluorine removability. More preferably, it is 5-50 mass parts of calcium hydrogenphosphate dihydrate (A) with respect to 100 mass parts of particle | grains (B), More preferably, it is 7-15 mass parts.

The calcium hydrogen phosphate dihydrate (A) is preferably a powder, and more preferably has an average particle size of 30 to 70 μm. When the average particle diameter is in the above range, calcium hydrogen phosphate can be efficiently carried on the particles (B), and a treatment agent having excellent fluorine removability can be obtained.

The average particle diameter of the calcium hydrogen phosphate dihydrate (A) is measured by a laser diffraction confusion method using Microtrack 9320HRA manufactured by Nikkiso Co., Ltd.

The calcium hydrogen phosphate dihydrate (A) is one of the preferred forms in which the particle surface is activated. The effect | action which insolubilizes the said fluorine increases more when the powdery particle | grains of a calcium hydrogenphosphate dihydrate (A) are suspended in water, and the particle | grain surface is activated.

The particles recovered from the suspension by suspending the powdered particles of calcium hydrogen phosphate dihydrate (A) in water and stirring or shaking the particles have a large number of tens of nanometers on the surface. The structure is such that fine crystals are uniformly deposited. The surface of such particles is activated, and for example, fluorine in fluorine-contaminated soil can be insolubilized more efficiently. Therefore, as the calcium hydrogen phosphate dihydrate (A) used in the treating agent of the present invention, the powder particles of calcium hydrogen phosphate dihydrate (A) are suspended in water and the particle surface is treated. Activated ones are preferred.

The particle (B) is a particle capable of supporting the calcium hydrogen phosphate dihydrate (A). By carrying the calcium hydrogen phosphate dihydrate (A) on the particles (B), a treatment agent having excellent water permeability and fluorine removability can be obtained.

Examples of the particles (B) include filtration sand and filtration gravel generally used for water purification, but the present invention is not limited to these. It is also preferable to use sand as the particles (B).

It is preferable that the particle (B) is substantially a particle having a particle size of 0.3 to 3.0 mm, and is substantially composed of only a particle having a particle size of 0.3 to 3.0 mm. preferable. As the particles (B), it is preferable that 90% by mass or more of the particles (B) have a particle diameter of 0.3 to 3.0 mm, and a more preferable ratio is 99% by mass or more. A more desirable ratio is 99.9% by mass or more. It is particularly preferable that the particles (B) do not contain particles having a particle diameter of less than 0.3 mm and do not contain particles having a particle diameter of more than 3.0 mm. When the particle diameter is in the above range, the calcium hydrogen phosphate dihydrate (A) is efficiently supported, so that the treatment agent can be made more excellent in water permeability and fluorine-containing compound removability. Most preferably, the particles (B) do not substantially contain particles having a particle diameter exceeding 2.8 mm.

The particle size of the particles (B) was manually screened using a standard mesh sieve (JIS Z8801, nominal size: 0.3 to 3.0 mm, sieve size: φ200, depth 45 mm). Ask. In order not to include particles having a particle diameter exceeding 2.8 mm, a sieve having a nominal size of 2.8 mm is used.

The particles (B) preferably have a uniformity coefficient of 1.5 or less. When the uniformity coefficient is in the above range, the calcium hydrogen phosphate dihydrate (A) is efficiently supported, and it is possible to provide a treatment agent that is more excellent in water permeability and excellent in removability of the fluorine-containing compound. it can.
The uniformity coefficient of the particles (B) is measured according to JWWA A103-1: 2004.

The treatment agent of the present invention may optionally contain components other than calcium hydrogen phosphate dihydrate (A) and particles (B) as long as the object of the present invention is not impaired. It is preferable that the calcium hydrogen dihydrate (A) and the particles (B) occupy 99% by mass or more in total.

The treatment agent of the present invention is preferably a treatment agent for fluorine-containing water, and is also preferably a treatment agent for fluorine-containing soil.

This invention is a method of manufacturing the said processing agent, Comprising: This manufacturing method mixes the calcium hydrogenphosphate dihydrate (A) and particle | grains (B) using a tilting cylinder type gravity mixer. It is also a manufacturing method of the processing agent containing.

The tilting cylinder type gravitational mixer is a type in which a mixing vessel for mixing calcium hydrogen phosphate dihydrate (A) and particles (B) is attached to a tilting cylinder mechanism. What is called a formula mixer may be used. The tilting cylinder mechanism is a mechanism for tilting the mixing container.

As a form of the tilting cylinder type gravitational mixer, for example, a frustoconical container is united, a mixing container having one end opened and the other end closed is attached to a tilting mechanism, and the mixing container What attached the blade | wing for mixing to an inner peripheral wall etc. are mentioned. The mixing container is preferably rotatable.

When mixing the calcium hydrogen phosphate dihydrate (A) and the particles (B), usually, the tilting cylinder mechanism is actuated so that the opening of the drum faces upward, and the mixing container is rotated in a certain direction. Calcium oxyhydrogen dihydrate (A) and particles (B) are charged. The charged materials are mixed by repeating the operation of being lifted by the blades and dropped downward.
Tilting cylinder type gravitational mixers are mixed by the behavior of the input materials. Therefore, mixing is performed while maintaining the state that calcium hydrogen phosphate dihydrate (A) is supported on particles (B). can do. Therefore, an especially excellent effect is exhibited in the production of the treatment agent.

As a manufacturing method of the said processing agent, calcium hydrogenphosphate dihydrate (A) and particle | grains (B) are put in the mixing container of a tilting-cylinder-type gravity mixer, and water is added and mixed as needed. It is preferable.

This invention is also a processing method (henceforth a "fluorine removal processing method") including the process which makes the said processing agent and the process target water containing fluorine contact, and removes the fluorine in this process target water. .

The contact between the treatment target water and the treatment agent may be a batch contact in which the treatment agent is added to the treatment target water, or a continuous contact in which the treatment target water is circulated through a column filled with the treatment agent. There may be. Moreover, it may be processed a plurality of times by batch contact, may be processed a plurality of times by continuous contact, or may be processed by combining batch contact and continuous contact. The packed column in the continuous contact may be a moving bed type, a fixed bed type, or a fluidized bed type.

The fluorine removal treatment method of the present invention may include a step of collecting treated water having a fluorine concentration of 0.8 mg / L or less. Since the said processing agent is excellent in water permeability and reaction efficiency, the fluorine contained in process target water can be removed efficiently and the fluorine concentration in water can be 0.8 mg / L or less. Moreover, since the said processing agent is carrying | supporting the calcium hydrogenphosphate dihydrate (A) by the particle | grain (B) with a comparatively large particle diameter, it can suppress that processing target water is suspended. The treatment agent and the treated water can be easily separated.

The fluorine content of the water to be treated is not particularly limited, and even if the content is small or at most, excellent fluorine removal ability can be exhibited. For example, it can be 0.1 mg / L or more. preferable. From the viewpoint of further exerting the effects of the present invention, it is more preferable to exceed 0.8 mg / L.

In the present invention, the fluorine ion concentration in the fluorine-containing water can be measured by a method based on JIS K0102.

The treatment target water to be contacted with the treatment agent is not particularly limited as long as it is fluorine-containing water (fluorine-containing water), and examples thereof include factory waste water, hot spring water, and river water. Factory wastewater includes fluorine-containing wastewater discharged from silicon wafer manufacturing plants, semiconductor manufacturing plants, etc., pickling wastewater discharged from metal plants, aluminum surface treatment wastewater, hydrofluoric acid manufacturing wastewater, fertilizer manufacturing wastewater, waste incineration wastewater, etc. Is mentioned.

The treatment target water preferably has a pH of 3 or more in that high removal efficiency of fluorine ions can be obtained. Accordingly, it is preferable that the treated water obtained by the fluorine removing treatment method of the present invention (hereinafter also simply referred to as “treated water”) has a pH of 3 or more. The pH is more preferably 4 or more. When the pH of the water to be treated or the treated water is less than 3, or when the pH is less than 3 during each step, the pH may be adjusted to 3 or more with sodium hydroxide, calcium hydroxide or the like.

Moreover, it is preferable that pHs of the said process target water and treated water are 11 or less. When pH exceeds 11, there exists a possibility that reaction of calcium hydrogenphosphate dihydrate (A) and a fluorine ion may become difficult to advance. When the pH of the fluorine-containing water or treated water exceeds 11, or when the pH exceeds 11 during each step, the pH may be adjusted to 11 or less with hydrochloric acid or the like.

According to the said fluorine removal processing method, the amount of fluorine removal per 1g of calcium hydrogenphosphate dihydrate (A) can be 1 mg-F / g or more, preferably 10 mg-F / g or more.

The fluorine removal treatment method of the present invention includes a step of adding calcium ions to water to be treated to produce calcium fluoride (CaF ₂ ), and a treatment in which the fluoride ion concentration is reduced by removing the produced calcium fluoride. A step of collecting the target water may be included. These steps are preferably performed before the step of bringing the treating agent into contact with the treatment target water containing fluorine and removing the fluorine in the treatment target water. Since these steps use a calcium compound that is relatively low in cost, the cost can be reduced particularly when the fluorine ion concentration of the water to be treated is high. The calcium ions are preferably added as calcium compounds such as slaked lime (Ca (OH) ₂ ), calcium carbonate (CaCO ₃ ), and calcium chloride (CaCl ₂ ).

The treated water is one from which fluorine has been sufficiently removed, has a low fluorine concentration (for example, 0.8 mg / L or less), and satisfies environmental standards.

The present invention is also a treatment method (hereinafter also referred to as “fluorine insolubilization treatment method”) in which the treatment agent and soil containing fluorine are mixed to insolubilize fluorine in the soil. When mixing the soil containing the treatment agent and fluorine, calcium hydrogen phosphate dihydrate (A) reacts with the soluble fluoride ion present in the _{soil, Ca 10 (PO 4) 6} F 2 Is formed and insolubilized.
When calcium hydrogen phosphate dihydrate (A) alone is mixed with soil containing fluorine, calcium hydrogen phosphate becomes lumps (aggregates) and cannot be sufficiently dispersed. However, since the calcium hydrogen phosphate is carried on the particles (B), the treatment agent of the present invention is excellent in dispersibility and can be efficiently mixed with fluorine-containing soil.

The fluorine insolubilization treatment method includes, for example, a step of producing the treatment agent by mixing calcium hydrogen phosphate dihydrate (A) and particles (B), and adding the treatment agent to fluorine-containing soil. It is preferable to include a process and a process of mixing the added treatment agent and soil containing fluorine.

The method for producing the treatment agent by mixing calcium hydrogen phosphate dihydrate (A) and particles (B) is not particularly limited, and examples thereof include a method using the above-mentioned tilted barrel type gravity mixer. .

The fluorine elution amount of the soil containing fluorine is not particularly limited, but may be, for example, 0.1 mg / L or more, and further 0.8 mg / L or more.

The soil is preferably soil or sludge, for example.

The soil is not particularly limited as long as it is generally referred to as soil. For example, sand, sand loam, loam, dredged soil, dredged soil, etc. can be used. . Furthermore, the soil etc. which mixed and adjusted the crushed water rock, the pulverized pumice, volcanic ash soil, etc. suitably are mentioned. Moreover, the soil etc. which are used as soil for home gardening may be used.

Examples of the sludge include solids formed by agglomeration of organic final products, which are generated in a process of a sewage treatment plant or a waste liquid process of a factory, and are also referred to as sludge. Moreover, the activated sludge etc. which are the agglomeration of microorganisms produced when a water treatment is performed by microorganism groups, such as aerobic bacteria, are also mentioned.

Since the treatment agent of the present invention has the above-described configuration, it is possible to easily and economically obtain treated water from which fluorine has been sufficiently removed, and elution of fluorine from the treated soil. The amount can be 0.8 mg / L or less of the soil environment standard.

FIG. 1 is a schematic diagram illustrating a filtration device according to the first embodiment. FIG. 2 is a schematic diagram showing a filtration device in Comparative Example 1.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

Example 1
Inclined torso type gravity mixer (capacity 110L), sand for rapid filtration (manufactured by Tokemi, “Japan Water Works Association Standard JWWA A103-1: 2004 standard product, effective diameter: 0.6 mm, uniformity coefficient: 1.5 or less, maximum Dia. 2.8 mm or less, minimum diameter 0.3 mm or more ") and calcium hydrogen phosphate dihydrate powder (manufactured by Taihei Chemical Industrial Co., Ltd.," average particle diameter: 54 μm "(hereinafter referred to as DCPD)) in total 100 masses 90 parts by mass of rapid filtration sand and 10 parts by mass of DCPD were added per part, and mixing was performed for 3 minutes.

FIG. 1 is a schematic diagram illustrating the filtration device according to the first embodiment. As shown in FIG. 1, a glass column housing 1 (φ10 cm) was filled with a mixture 2 of rapid filtration sand and DCPD obtained by the above mixing and glass wool 3 to obtain a filtration device 5.
Next, the water to be treated containing fluorine was injected at a flow rate of 50 ml / min from a pipe 6 connected to the upper part of the filtration device 5, and treated water was obtained from the pipe 7 connected to the lower part of the device. As shown in FIG. 1, the treatment target water 4 containing fluorine is treated by allowing the mixture 2 to permeate through the column housing 1. In this example, the water permeability of the mixture 2 was evaluated by the change in the water level of the water surface 8. Table 1 shows the flow rate, fluorine concentration and water level of the water to be treated, and the flow rate and fluorine concentration of the treated water. The treatment target water containing fluorine and the fluorine concentration in the treatment water were measured by a method based on JIS K0102.

Even after 120 days from the start of water permeation, the fluorine concentration of the treated water was maintained below the environmental standard value. The water level did not change even after 120 days. That is, the water permeability did not change.

(Example 2)
General sand for mortar, concrete, etc. used for civil engineering / architectural purposes (effective diameter: 0.1 to 5 mm, maximum diameter exceeding 3.0 mm, 5) 0 mm or less) and 100 parts by mass of DCPD, 90 parts by mass of sand and 10 parts by mass of DCPD were added and mixed for 3 minutes.

In the same manner as in Example 1, the obtained mixture was filled into a glass column housing, a filtration device was created, water to be treated containing fluorine was injected from the top of the filtration device, and water permeability was evaluated. The fluorine concentration was measured. The results are shown in Table 2.

Comparing the results of Example 1 and Example 2, water permeability is better when DCPD is supported on sand for rapid filtration than when DCPD is supported on general sand. These results indicate that the particle size of the particles (B) serving as the carrier is important for improving water permeability. It is also noted that rapid filtration sand contains more moisture than common sand. However, in an experiment conducted by the present inventors, when a general sand was immersed in pure water and then mixed with DCPD, some DCPD aggregation was observed.

(Comparative Example 1)
The experiment was performed in the same manner as in Example 1 except that DCPD was used alone instead of the mixture of rapid filtration sand and DCPD. As shown in FIG. 2, a glass column housing 1 (φ10 cm) was filled with DCPD 9 and glass wool 3 to obtain a filtration device 5a. DCPD is the same as that in the first embodiment.
Next, when the target water containing fluorine was injected from the pipe 6 connected to the upper part of the apparatus at a flow rate of 50 ml / min, the water level 8 of the processing target water containing fluorine rose and reached the upper surface of the apparatus shortly after the injection. No treated water was obtained. Table 3 shows the flow rate, fluorine concentration and water level of the water to be treated, and the flow rate and fluorine concentration of the treated water. In addition, since the treated water was not obtained, the fluorine concentration of the treated water was not measurable.

(Comparative Example 2)
The bead is used for tilting barrel type gravity mixer (capacity 110L), beads (effective diameter: 2-4mm) and DCPD, which are generally used for handicrafts and decoration, and 100 parts by mass of DCPD. Were added at a ratio of 90 parts by mass and 10 parts by mass of DCPD, and mixed for 3 minutes.

In the same manner as in Example 1, the obtained mixture was filled in a glass column housing, a filtration device was created, and water to be treated containing fluorine was injected from the top of the filtration device, and the beads began to float, The treated water at the top of the filtration device became cloudy. In the same manner as in Example 1, water permeability was evaluated and the fluorine concentration was measured. The results are shown in Table 4. These results indicate that DCPD is not fully supported on the beads.

Since the treatment agent of the present invention has the above-mentioned configuration, in the field where fluorine-containing water and fluorine-containing soil are generated, such as electroplating industry, semiconductor manufacturing industry, electron tube manufacturing industry, and glass industry. It can be suitably used.

1: Glass column housing 2: Mixture of sand for rapid filtration and DCPD 3: Glass wool 4: Water to be treated 5 containing fluorine 5a: Filtration device 6, 7: Tube 8: Water surface 9: DCPD

Claims (5)

Calcium hydrogen phosphate dihydrate (A) and particles (B), calcium hydrogen phosphate dihydrate (A) is supported on the particles (B), the particles (B) are filtered sand, is a filter gravel or sand, the particles (B) is substantially Ri Oh particle size of particles of 0.3 to 3.0 mm, and a uniformity coefficient of 1.5 or less, calcium hydrogen phosphate dihydrate hydrate (a), the process average particle size, characterized in 30~70μm der Rukoto agent. A method of manufacturing a claim 1 Symbol placement of the treatment agent,
The manufacturing method of the processing agent characterized by including the process of mixing a calcium hydrogenphosphate dihydrate (A) and particle | grains (B) using a tilting cylinder type gravity mixer. Contacting the water to be treated containing a treatment agent and fluorine of claim 1 Symbol mounting, processing method which comprises a step of removing fluorine of the water being treated. Processing method according to claim 1 Symbol mixing the soil containing the placing of treatment agent and fluorine, characterized in that it comprises a step of insolubilizing the fluorine in said soil. The processing method according to claim 4 , wherein the soil is soil or sludge.

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