KR20100015911A - Water-treating agent and method of treating water - Google Patents

Abstract

A water-treating agent with which water containing a harmful substance can be treated to easily and efficiently remove the harmful substance; and a method of water treatment by which a harmful substance can be efficiently removed with a small amount of a chemical and a simple device through a simple operation. The water-treating agent is characterized by comprising at least either of the following (A) and (B). The method of water treatment is characterized by using the water-treating agent. (A) A calcium sulfoaluminte hydrate and/or a substance obtained by heat-treating calcium sulfoaluminte hydrate (B) A mixture of: calcium aluminate and/or a substance obtained by heat-treating calcium aluminate; and a sulfuric acid salt.

Description

WATER-TREATING AGENT AND METHOD OF TREATING WATER}

The present invention relates to a water treatment agent and a water treatment method. More specifically, the present invention relates to a water treatment agent capable of easily and efficiently removing harmful substances from water containing harmful substances, and a water treatment method capable of efficiently removing harmful substances in a small amount of medicine by a simple apparatus and operation.

Industrial wastewater resulting from the manufacturing process of various products, the refinery process of combustion gas, the purification process of contaminated soil, etc. are used for selenium, copper, chromium, molybdenum, antimony, lead, arsenic, zinc, cadmium, Heavy metals, such as nickel, manganese, iron, tin, and cobalt, and various harmful substances, such as boron, fluorine, and phosphorus, are contained. Since these harmful substances may adversely affect animals and plants, it is mandated by law that the wastewater is discharged into public waters such as rivers, lakes, swamps and sea areas after removing these harmful substances. It is.

As a general method for removing toxic substances, alkali precipitation method, coprecipitation method, ion exchange method, biological treatment and the like are known. However, the alkali precipitation method is effective for metals which form precipitates in alkaline, but has no removal effect on substances that do not form precipitates in alkaline such as fluorine and boron, and also removes a large amount of chemicals to remove harmful substances. It is necessary to add, and there exists a problem of causing increase in the amount of chemicals used and sludge generation amount. Similarly, in the coprecipitation method, there is a harmful substance which does not have an elimination effect depending on the type of coprecipitation, and since it is necessary to add a large amount of drugs, the problem of causing an increase in the amount of chemicals used and sludge generation, or the addition of a coprecipitation agent Therefore, there is a problem that secondary pollution is also concerned. The ion exchange method saturates as soon as the concentration of toxic substances is high, so that there is a problem that the efficiency is poor and the cost is high. There is a problem that biological treatment is susceptible to coexistence substances and needs to maintain growth conditions suitable for treatment.

Among the harmful substances, boron is concerned about excessive growth of boron, inhibiting plant growth, reproductive inhibition of animals, and neurological and digestive disorders.In 2001, the Enforcement Decree of the Water Pollution Prevention Act was partially revised. The standard for draining boron and its compounds in public waters other than sea areas such as rivers, lakes and swamps was set to 10 mg / L or less.

Boron is used for various industrial uses such as raw materials, such as dyes, components of alloys and semiconductor materials, and electroplating, including the glass industry, and wastewater generated in these manufacturing processes contains boron. In addition, boron is often contained in wastewater generated from power plants, sewage wastewater in waste incineration plants, landfill leachate wastewater, and the like. Boron is also included in the waste water from the inn business that operates the hot springs. As such, boron is contained in various wastewaters.

Examples of the boron treatment technique include a coagulation sedimentation method, an ion adsorption method, a solvent extraction method, an evaporation concentration method, a reverse osmosis membrane method, and the like. In the flocculation sedimentation method, it is necessary to use a large amount of drugs in order to sufficiently remove boron, and there is a problem of causing an increase in the amount of drug used and an increase in sludge generation amount. In addition, when chloride ions coexist in the treated water, there is a problem that the removal rate is lowered. In the ion adsorption method, in order to treat water containing a relatively high concentration of boron, a load is placed on the chelating resin to be used, and thus the efficiency is poor, and there is a problem that not only the cost of the chelating resin itself but also the regeneration treatment costs. . In the solvent extraction method, since the organic solvent as the extractant is dissolved in the treated water from which boron has been removed, it is necessary to remove the organic solvent, and there is a problem that the cost is high due to the loss of the drug. The evaporation concentration method requires a heat source for evaporation, enormous energy is required to crystallize the boron compound, the reverse osmosis membrane method has a low boron removal rate, and there is also a problem of membrane blockage.

In order to solve these problems, the method of treating boron containing water by combining the flocculation settling method using an aluminum compound and a calcium compound, and the ion adsorption method using an anion exchange resin is proposed (patent document 1, 2). However, also in this method, it is necessary to add a large amount of chemical | medical agent, the amount of generated mud is large, and the process is difficult. In addition, a method of treating boron-containing water by combining an evaporation concentration method and a coagulation sedimentation method (Patent Document 3) or a method of treating a boron-containing water by combining an evaporation concentration method, a coagulation sedimentation method and an ion adsorption method (Patent Document 4) Proposed. However, even in these methods, a large amount of heat is required for evaporation, and the apparatus becomes large, the processing process becomes complicated, and the cost becomes high. In addition, although a harmful substance immobilization material which removes fluorine and sludge phosphate ions from the waste liquid has been proposed (Patent Document 5), boron which is difficult to form a precipitate in an aqueous solution even by addition of a salt or the like. The effect on is unknown. In addition, although a wastewater treatment method of adding aluminum salt, poorly soluble calcium salt, and calcined lime and adjusting the pH to adjust the pH of boron is also proposed (Patent Document 6), the calcium aluminate hydrate generated in water and the poorly soluble calcium salt have been proposed. In combination, there exists a problem that sufficient boron removal force is not obtained.

Patent Document 1: Japanese Patent Application Laid-Open No. 57-81881

Patent Document 2: Japanese Patent Application Laid-Open No. 57-180493

Patent Document 3: Japanese Patent Application Laid-Open No. 7-323292

Patent Document 4: Japanese Patent Application Laid-Open No. 10-314798

Patent Document 5: Japanese Patent Application Laid-Open No. 2000-93927

Patent Document 6: Japanese Patent Application Laid-Open No. 2004-283731

This invention solves the various problems in the said prior art, and makes it a subject to achieve the following objectives. That is, the present invention provides a water treatment agent capable of easily and efficiently removing harmful substances from water containing harmful substances, and a water treatment method capable of efficiently removing harmful substances in a small amount of medicine by a simple apparatus and operation. For the purpose of

MEANS TO SOLVE THE PROBLEM The present inventors earnestly researched in order to achieve the said objective, and, as a result, (A) calcium sulfoaluminate hydrate and / or the substance obtained by heat-processing calcium sulfoaluminate hydrate, and (B) calcium By using a water treatment agent containing at least one of a mixture of a substance obtained by heat treatment of the aluminate and / or calcium aluminate and a sulfate, harmful substances can be removed from the water containing harmful substances easily and efficiently. The present invention was completed, and the present invention was completed. The present invention also provides a water treatment method using the water treatment agent.

This invention is based on the said knowledge by the present inventors, As means for solving the said subject, it is as follows. In other words,

<1> It is a water treatment agent containing at least any one of following (A) and (B).

(A) A substance obtained by heat treating calcium sulfoaluminate hydrate and / or calcium sulfoaluminate hydrate.

(B) A mixture of a substance obtained by heat treatment of calcium aluminate and / or calcium aluminate and a sulfate

<2> (A) As a water treatment agent containing the substance obtained by heat-processing calcium sulfoaluminate hydrate and / or calcium sulfoaluminate hydrate, (C) calcium aluminate and / or calcium aluminate It is a water treatment agent as described in said <1> containing the substance obtained by heat processing.

<3> Moreover, it is a water treatment agent in any one of said <1> to <2> containing (D) carbonate.

<4> Moreover, it is a water treatment agent in any one of said <1> to <3> containing (E) aluminum compound.

<5> It is a water treatment agent containing the substance obtained by heat-processing the substance insoluble in water collect | recovered after carrying out water treatment using the water treatment agent in any one of said <1>-<4>.

<6> It is a water treatment method using the water treatment agent in any one of said <1>-<5>.

According to the present invention, by solving a number of problems in the prior art, the above object can be achieved, by a water treatment agent that can easily and efficiently remove harmful substances from water containing harmful substances, and by a simple apparatus, operation, It is possible to provide a water treatment method capable of efficiently removing harmful substances with a small amount of pharmaceuticals.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the evaluation method of the cohesiveness (precipitation) of a water treatment agent (a: height of a gas-liquid interface (mm), b: height of a solid-liquid interface (mm)).

FIG. 2 is a diagram showing aspects of evaluating the cohesiveness (sedimentation) after water treatment for each of the water treatment agents of Example 7 and Example 24 (left: Example 7, right: Example 24).

3 is an X-ray diffraction chart of ethringite.

4 is an X-ray diffraction chart of calcium aluminate.

5 is an X-ray diffraction chart of a co-existence of ethringite and calcium aluminate.

(Water treatment agent)

The water treatment agent of the present invention is prepared by heat treating (A) calcium sulfoaluminate hydrate, and / or calcium sulfoaluminate hydrate, and (B) calcium aluminate and / or calcium aluminate. It is characterized by containing at least any one of the mixture of the substance obtained by this and a sulfate. In addition, the water treatment agent preferably further contains at least one of (C) calcium aluminate and / or a substance obtained by heat treatment of calcium aluminate, (D) carbonate, and (E) aluminum compound. It is made to contain and contains another component as needed.

In addition, "the substance obtained by heat-treating (A) calcium sulfoaluminate hydrate and / or calcium sulfoaluminate hydrate", "(B) calcium aluminate and / or calcium aluminate by heat-processing A mixture of a substance obtained and a sulfate '', the "(C) calcium aluminate and / or a substance obtained by heat-treating calcium aluminate", said "(D) carbonate", and said "(E) Aluminum compound "is only called" (A) component "," (B) component "," (C) component "," (D) component ", and" (E) component "in this specification, respectively. There is a thing.

<(A) component>

The said (A) component is a substance obtained by heat-processing calcium sulfo aluminate hydrate and / or calcium sulfo aluminate hydrate (in this specification, what is only called "calcium sulfo aluminate hydrate heat-processed thing"). Is).

Calcium sulfoaluminate hydrate

There is no restriction | limiting in particular as said calcium sulfo aluminate hydrate, For example, there are a trisulfate type and a monosulfate type, Among these, it is preferable to use a trisulfate type calcium sulfo aluminate hydrate. As said trisulfate type calcium sulfo aluminate hydrate, an ethringite etc. are mentioned, for example. In addition, the said calcium sulfoaluminate hydrate may use what was synthesize | combined, and may use what exists in nature.

--Synthesis of Calcium Sulfoaluminate Hydrate--

The calcium sulfoaluminate hydrate can be obtained, for example, by synthesis, and the synthesis is not particularly limited and can be performed by a known method. For example, it can synthesize | combine by mixing a calcium compound, an aluminum compound, and a sulfuric acid compound in water, and can also synthesize | combine a calcium compound, an aluminum compound, and a sulfuric acid compound, baking, hydrating, and synthesize | combining (solid state method). There is no restriction | limiting in particular also as an apparatus used for the said baking process, For example, it can carry out using a well-known hot air dryer, an electric furnace, a thermostat, a fluidized bed dryer, a vacuum dryer, a spray dryer, a rotary kiln, etc.

The calcium compound at this time is not particularly limited as long as it contains calcium, and examples thereof include calcium hydroxide, calcium nitrate, calcium sulfate, calcium oxide, calcium carbonate, calcium chloride, hydrates thereof, and the like. It can be used individually by 1 type or in combination of 2 or more types. The aluminum compound is not particularly limited as long as it contains aluminum, and examples thereof include aluminum sulfate, aluminum nitrate, aluminum hydroxide, aluminum oxide, aluminum chloride, polyaluminum chloride (PAC), aluminum carbonate, sodium aluminate and potassium aluminate. These etc., these hydrates, etc. are mentioned, These can be used individually by 1 type or in combination of 2 or more types. The sulfuric acid compound is not particularly limited as long as it contains sulfuric acid, and examples thereof include aluminum sulfate, sodium sulfate, calcium sulfate, potassium sulfate, potassium aluminum sulfate, magnesium sulfate, sulfuric acid and the like, and hydrates thereof. It can be used individually by 1 type or in combination of 2 or more types. In addition, these raw materials can be used not only pure products but also those containing impurities such as aluminum sludge.

PH and Stir Aging of Synthesis Reaction of Calcium Sulfoaluminate Hydrate

In the synthesis reaction of the calcium sulfoaluminate hydrate, the pH is preferably 9 or more, and more preferably 11 or more. When pH adjustment is necessary, a general pH adjuster can be used. The pH adjuster is not particularly limited and includes, for example, acids such as carbon dioxide gas, sulfuric acid, hydrochloric acid, nitric acid, sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminum hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, Alkali agents, such as ammonia, can be used individually by 1 type or in combination of 2 or more types.

In addition, in the synthesis | combination reaction of the said calcium sulfoaluminate hydrate, stirring may be performed after pH adjustment and may not be carried out. Stirring may be performed at normal temperature, or may be performed while warming. In addition, after stirring, you may age or may not do it.

Calcium sulfoaluminate hydrate heat treatment

The calcium sulfoaluminate hydrate heat treated product can be obtained by heat treating the calcium sulfoaluminate hydrate. The heat treatment of the calcium sulfoaluminate hydrate is preferably performed at a temperature of 60 ° C. or higher, more preferably 100 ° C. or higher, for 10 minutes or more, and more preferably for 30 minutes or more. Although there is no restriction | limiting in particular as an upper limit of the said heating temperature, 1600 degrees C or less is preferable. The upper limit of the heating time is not particularly limited, but is preferably within 24 hours.

In this heat treatment, weight reduction due to dehydration of the hydrated water of the calcium sulfoaluminate hydrate occurs. For example, it is preferable that the weight reduction rate is 15% or more, more preferably 20% or more, and even more preferably 30% or more by the above heat treatment. In addition, the said weight loss rate is taken as the ratio (%) of the weight loss after heat processing with respect to the initial weight of calcium sulfoaluminate hydrate.

The heat treatment may be carried out under an atmospheric pressure environment or may be carried out under reduced pressure. In addition, after the synthesized calcium sulfoaluminate hydrate is dried, heat treatment may be performed, or heat treatment may be performed without drying. In addition, when synthesize | combining calcium sulfo aluminate hydrate by the solid-phase method as mentioned above, the thing which mixed and calcined can be used as said calcium sulfo aluminate hydrate heat-processed material. There is no restriction | limiting in particular also as an apparatus used for the said heat processing, For example, it can carry out using a well-known hot air dryer, an electric furnace, a thermostat, a fluidized bed dryer, a vacuum dryer, a spray dryer, a rotary kiln, etc.

Calcium sulfoaluminate hydrates / heat treated materials

The calcium sulfoaluminate hydrate and the calcium sulfoaluminate hydrate heat-treated product may be used alone as the (A) component, or may be used in combination with the both as the (A) component. . There is no restriction | limiting in particular as a usage-amount ratio of the said calcium sulfo aluminate hydrate and the said calcium sulfo aluminate hydrate heat treatment in the case of using both together, According to the objective, it can select suitably.

In the calcium sulfoaluminate hydrate and the calcium sulfoaluminate hydrate heat treated product, the calcium sulfo aluminate hydrate heat treated product has a higher harmful substance removal ability. Therefore, from the viewpoint of improving the ability to remove harmful substances, it is preferable to use a lot of the calcium sulfoaluminate hydrate heat treatment as the component (A), and to use the calcium sulfo aluminate hydrate heat treatment alone. It is more preferable.

<(B) component>

The said (B) component is a mixture of the substance obtained by heat-processing calcium aluminate and / or calcium aluminate (it may only call "calcium aluminate heat processing material" in this specification), and a sulfate. .

Calcium Aluminate

The calcium aluminate is a generic term for compounds mainly composed of CaO and Al ₂ O ₃ , and is not particularly limited and can be appropriately selected depending on the purpose. For example, CaAl ₂ O ₄ , CaAl ₄ O ₇ , CaAl ₁₂ O ₁₉ , Ca ₃ Al ₂ O ₆ , Ca ₁₂ Al ₁₄ O ₃₃ , Ca ₅ Al ₆ O ₁₄ , Ca ₉ Al ₁₀ O ₂₄ , Ca ₂ Al ₂ O ₅ , mixtures thereof, hydrates thereof, and the like. Can be. Among these, as the calcium aluminate, Ca ₁₂ Al ₁₄ O ₃₃ , Ca ₃ Al ₂ O _6, or a mixture thereof are preferable because the ability to remove harmful substances can be improved. The said calcium aluminate can be used individually by 1 type or in combination of 2 or more types.

In addition, the calcium aluminate may contain an impurity, and the kind and content thereof are not particularly limited as long as it is within a range that does not impair the effects of the present invention. Specific examples thereof include, for example, Fe ₂ O ₃ and SiO _2. , MgO, TiO ₂ , P ₂ O ₅ , Cl and the like. The calcium aluminate may be a crystalline compound, an amorphous compound, a synthetic product, or may be naturally produced. Moreover, the particle diameter also does not have a restriction | limiting in particular, For example, 0.1 micrometer or more is preferable at the point of handling.

Synthesis of Calcium Aluminate

The calcium aluminate can be obtained, for example, by synthesis, and the synthesis is not particularly limited and can be performed by a known method. For example, it can synthesize | combine by mixing a calcium compound and an aluminum compound in water, and synthesize | combine by mixing high temperature baking at the temperature of 1000 degreeC or more, preferably 1300 degreeC or more by mixing an aluminum compound and a calcium compound (solid-phase method). It may be. There is no restriction | limiting in particular also as an apparatus used for the said baking process, For example, it can carry out using a well-known hot air dryer, an electric furnace, a thermostat, a fluidized bed dryer, a vacuum dryer, a spray dryer, a rotary kiln, etc. The calcium compound at this time is not particularly limited as long as it contains calcium, and examples thereof include calcium hydroxide, calcium nitrate, calcium oxide, calcium carbonate, calcium chloride and the like, and hydrates thereof. It can be used individually or in combination of 2 or more types. The aluminum compound is not particularly limited as long as it contains aluminum. Examples of the aluminum compound include aluminum nitrate, aluminum hydroxide, aluminum oxide, aluminum chloride, polyaluminum chloride (PAC), aluminum carbonate, sodium aluminate, potassium aluminate, and the like. Hydrates thereof, and the like, and these may be used alone or in combination of two or more thereof. In addition, these raw materials can be used not only pure products but also those containing impurities such as aluminum sludge.

PH and Stir Aging of Synthesis of Calcium Aluminate

In the synthesis reaction of the calcium aluminate, the pH is preferably set to 9 or more. When pH adjustment is necessary, a general pH adjuster can be used. The pH adjuster is not particularly limited, and examples thereof include acids such as carbon dioxide gas, hydrochloric acid, and nitric acid, sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminum hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonia, and the like. May be used alone or in combination of two or more.

In addition, in the synthesis | combination reaction of the said calcium aluminate, you may perform stirring after pH adjustment and may not do it. Stirring may be performed at normal temperature, or may be performed while warming. In addition, after stirring, you may age or may not do it.

Calcium Aluminate Heat Treatment

The calcium aluminate heat treated product can be obtained by heat treating the calcium aluminate. The heat treatment of calcium aluminate is preferably performed at a temperature of at least 60 ° C, more preferably at least 100 ° C, for at least 10 minutes, more preferably at least 30 minutes. Although there is no restriction | limiting in particular as an upper limit of the said heating temperature, 1600 degrees C or less is preferable. The upper limit of the heating time is not particularly limited, but is preferably within 24 hours.

The heat treatment may be carried out under an atmospheric pressure environment or may be carried out under reduced pressure. The synthesized calcium aluminate may be subjected to heat treatment after drying, or may be subjected to heat treatment without drying. There is no restriction | limiting in particular also as an apparatus used for the said heat processing, For example, it can carry out using a well-known hot air dryer, an electric furnace, a thermostat, a fluidized bed dryer, a vacuum dryer, a spray dryer, a rotary kiln, etc.

-sulfate-

There is no restriction | limiting in particular as said sulfate, According to the objective, it can select suitably, For example, sodium sulfate, potassium sulfate, lithium sulfate, silver sulfate, calcium sulfate, ferrous sulfate, ferric sulfate, sulfuric acid Nickel, cobalt sulfate, magnesium sulfate, barium sulfate, copper sulfate, manganese sulfate, aluminum sulfate, sodium aluminum sulfate, potassium aluminum sulfate, etc. are mentioned. Moreover, as said sulfate, these hydrates may be sufficient.

Among these, as said sulfate, 1 or more types chosen from calcium sulfate, sodium sulfate, and aluminum sulfate are preferable, and especially calcium sulfate is especially preferable. As said sulfate, the water treatment agent containing at least calcium sulfate is excellent also in the fall of the concentration of sulfate ion in the water after treatment in addition to the toxic substance removal power, and therefore, it can remove toxic substances efficiently with a small amount of medicine, This is advantageous in that secondary pollution by sulfate ions can also be reduced. Examples of the calcium sulfate include calcium sulfate (anhydrous), calcium sulfate dihydrate, calcium sulfate 0.5 hydrate, and the like. The strengths of these toxic substances removing powers are calcium sulfate (anhydrous)> calcium sulfate Dihydrate 칼슘 Calcium sulfate, 0.5 hydrate. Moreover, when calcium sulfate is used as said sulfate, it is advantageous at the point which can improve the removal power of a toxic substance by using in combination with high water solubility sodium sulfate and aluminum sulfate. The said sulfate can be used individually by 1 type or in combination of 2 or more types.

The sulfate may be used as it is, or may be used in a state dissolved or dispersed in water. The sulfate can also be produced, for example, by mixing sulfuric acid with the corresponding hydroxide in water (e.g., producing sulfuric acid with sulfuric acid and calcium hydroxide, sulfuric acid with sulfuric acid and sodium hydroxide). Sodium may be produced), and may be used in the form of an aqueous solution containing the produced sulfate.

Calcium aluminate and / or its heat treated product / sulphate

The calcium aluminate and / or its heat treated product and the sulfate are used in combination with both of them as the component (B). In addition, as said "mixture of calcium aluminate and / or its heat-treated product with sulfate," it is not necessary to necessarily use the said calcium aluminate and / or its heat-treated material and the said sulfate in the state which mixed previously, The calcium aluminate and / or its heat-treated product and the sulphate may be added in water, respectively. In addition, when the calcium aluminate and / or its heat treated product and the sulfate are added to and used in water, respectively, the sulfate is added first, and then the calcium aluminate and / or the heat treated product is added thereto. The aspect to be used is advantageous at the point which can improve the removal power of a toxic substance more.

There is no restriction | limiting in particular as a usage-amount ratio of the said calcium aluminate and / or its heat-treated thing, and the said sulfate, Although it can select suitably according to the objective, For example, a calcium aluminate and / or its heat-treatment is carried out by mass ratio. : Sulfate = 20: 80-90: 10 is preferable, 25: 75-75: 25 is more preferable, 30: 70-70: 30 is still more preferable. If the usage-amount ratio is in the said preferable range, it is advantageous at the point which can remove the harmful substance removal power and can suppress generation | occurrence | production of sludge after a hazardous substance treatment.

<(A) component / (B) component>

The said water treatment agent should just contain at least one of the said (A) component and the said (B) component, ie, as a combination of the said (A) component and the said (B) component, (1) The aspect of thru | or (7) is mentioned.

(1) A water treatment agent containing calcium sulfoaluminate hydrate ((A) component).

(2) The water treatment agent containing the substance ((A) component) obtained by heat-processing calcium sulfo aluminate hydrate.

(3) The water treatment agent containing the substance ((A) component) obtained by heat-processing a calcium sulfoaluminate hydrate and calcium sulfoaluminate hydrate.

(4) A water treatment agent containing a mixture ((B) component) of a substance obtained by heat treatment of calcium aluminate and / or calcium aluminate and sulfate.

(5) A water treatment agent containing a mixture ((B) component) of a substance obtained by heat treatment of calcium sulfoaluminate hydrate ((A) component), and calcium aluminate and / or calcium aluminate and sulfate.

(6) A substance obtained by heat treatment of calcium sulfoaluminate hydrate ((A) component), and a mixture of a substance obtained by heat treatment of calcium aluminate and / or calcium aluminate and sulfate ((B)) Component).

(7) a substance obtained by heat treating calcium sulfoaluminate hydrate and calcium sulfoaluminate hydrate (component (A)), and a substance obtained by heat treating calcium aluminate and / or calcium aluminate, A water treatment agent containing a mixture with the sulfate ((B) component).

The water treatment agents of the above aspects (1) to (7) all have high harmful substance removal ability, and therefore, the harmful substances can be easily and efficiently removed from the harmful substance-containing water.

Among these, the water treatment agent of the aspect of said (4)-(7) containing at least the said (B) component is excellent also in the cohesiveness (precipitation) of a water treatment agent in addition to the removal power of a hazardous substance, Therefore, a water treatment agent after treatment of a hazardous substance In order to recover, it is not necessary to add an expensive flocculant or to leave it to stand for a long time until flocculation (sedimentation), and is advantageous in that the treated water and the water treatment agent after the hazardous substance treatment can be easily separated. Further, as the sulfate of the component (B), a water treatment agent containing at least calcium sulfate and its hydrate is excellent in reducing the concentration of sulfate ions in water after treatment in addition to the ability to remove harmful substances and excellent cohesiveness (sedimentation). In addition, it is advantageous in that the harmful substances can be efficiently removed with a small amount of pharmaceutical agents, and also secondary pollution by sulfate ions can be reduced.

Moreover, as an aspect of said (5)-(7), when using together the said (A) component and the said (B) component, it is especially restrict | limited as the usage-amount ratio of the said (A) component and the said (B) component. Although it can select suitably according to the objective, For example, (A) component: (B) component = 5: 95-90: 10 are preferable at mass ratio, and 10: 90-80: 20 is more preferable. . It is advantageous at the point that cohesion (sedimentation) improves that the said usage-amount ratio exists in the said preferable range.

<(C) component>

The said (C) component is a substance obtained by heat-processing calcium aluminate and / or calcium aluminate (it may only call "calcium aluminate heat processing material" in this specification).

In the water treatment agent of the aspect of the said (1)-(3) (state containing only the said (A) component among the said (A) component and the said (B) component), Furthermore, as a said (C) component, calcium aluminate And / or calcium aluminate heat treated materials. In addition to the component (A), the water treatment agent containing the component (C) is excellent in reducing the concentration of sulfate ions in the water after treatment in addition to the ability to remove the harmful substances, and therefore, it is possible to efficiently remove harmful substances in a small amount of chemicals. It is advantageous in that it can remove, and also the secondary contamination by sulfate ion can be reduced.

Calcium Aluminate

There is no restriction | limiting in particular as a kind of calcium aluminate as said (C) component, According to the objective, it can select suitably, For example, calcium aluminate like calcium aluminate contained in the item of said (B) component (Example For example, CaAl ₂ O ₄ , CaAl ₄ O ₇ , CaAl ₁₂ O ₁₉ , Ca ₃ Al ₂ O ₆ , Ca ₁₂ Al ₁₄ O ₃₃ , Ca ₅ Al ₆ O ₁₄ , Ca ₉ Al ₁₀ O ₂₄ , Ca ₂ Al ₂ O ₅ , a mixture thereof, hydrates thereof, and the like) can be suitably used. Moreover, there is no restriction | limiting in particular also as the acquisition method of the said calcium aluminate, For example, it can synthesize | combine by the method similar to the synthesis | combining method as described in the item of the said (B) component.

Calcium Aluminate Heat Treatment

The calcium aluminate heat treated product as the component (C) is also not particularly limited and can be appropriately selected depending on the purpose. For example, the calcium aluminate heat treated product contained in the item of the component (B) and Likewise, the calcium aluminate can be obtained by heat treatment. There is no restriction | limiting in particular also as the heat processing method of the said calcium aluminate, For example, it can carry out by the method similar to the heat processing method of the calcium aluminate described in the item of the said (B) component.

Calcium Aluminate / Heat Treatment

Any one of the calcium aluminate and the calcium aluminate heat treated product may be used alone as the (C) component, or both may be used in combination as the (C) component. There is no restriction | limiting in particular as a usage-amount ratio of the said calcium aluminate and the said calcium aluminate heat processing thing in the case of using both together, According to the objective, it can select suitably.

<(A) component / (C) component>

As mentioned above, the said (C) component is used together with the said (A) component at least. There is no restriction | limiting in particular as a usage-amount ratio of the said (A) component and the said (C) component, Although it can select suitably according to the objective, For example, by mass ratio, (A) component: (C) component = 35: 65- 95: 5 is preferable and 45:55 to 85:15 are more preferable. If the amount of use is within the above-mentioned preferred range, in addition to the ability to remove harmful substances, it is also excellent in lowering the concentration of sulfate ion in water after treatment, and therefore, it is possible to efficiently remove harmful substances in a small amount of chemical agent, while also providing sulfate ion. It is advantageous in that the secondary pollution by can also be reduced.

Coexistence of calcium sulfoaluminate hydrate and calcium aluminate

Moreover, as said (A) component and said (C) component, for example, the coexistence of the calcium sulfoaluminate hydrate which is a kind of said (A) component, and calcium aluminate which is a kind of said (C) component (this In the specification, only the "coexistence" may be referred to). Here, the coexistence is a structure in which peaks of both calcium sulfoaluminate hydrate and calcium aluminate can be observed by wide-angle X-ray diffraction measurement. For reference, the X-ray diffraction chart of ethringite, which is a kind of calcium sulfoaluminate hydrate, is shown in FIG. 3, and the X-ray diffraction chart of calcium aluminate is shown in FIG. 4, and the coexistence of ethrinite and calcium aluminate is shown in FIG. An X-ray diffraction chart is shown in FIG. In addition, the wide-angle X-ray-diffraction measurement was measured with the light source Cu-K-ALPHA1 / 40 Hz / 20 Hz and scanning speed 4.0 degrees / min using the X-ray-diffraction apparatus (RINT2100 made from Rigaku Corporation).

--Synthesis of Coexistence of Calcium Sulfoaluminate Hydrate and Calcium Aluminate--

When preparing calcium sulfo aluminate hydrate, the said coexistent can be synthesize | combined by adding the sulfuric acid compound of less than theoretical amount. Here, if the sulfuric acid compound is added, the amount of sulfuric acid compound added is not particularly limited, but is preferably from 20% to 80% of the theoretical amount.

Heating treatment of coexistence of calcium sulfoaluminate hydrate and calcium aluminate

In addition, as said (A) component and said (C) component, you may use the substance obtained by heat-processing the said coexistence (in this specification, it may only call "coexistent heat-treated thing"). . It is preferable to perform the heat processing of the said coexistence body at 60 degreeC or more, More preferably, 100 degreeC or more, for 10 minutes or more, It is more preferable to carry out for 30 minutes or more. Although there is no restriction | limiting in particular as an upper limit of the said heating temperature, 1600 degrees C or less is preferable. The upper limit of the heating time is not particularly limited, but is preferably within 24 hours.

The heat treatment may be carried out under an atmospheric pressure environment or may be carried out under reduced pressure. In addition, heat treatment may be performed after drying the synthesized coexistence, or heat treatment may be performed without drying. There is no restriction | limiting in particular also as an apparatus used for heat processing, For example, it can carry out using a well-known hot air dryer, an electric furnace, a thermostat, a fluidized bed dryer, a vacuum dryer, a spray dryer, a rotary kiln, etc.

<(D) component>

The said (D) component is a carbonate.

It is preferable that the said water treatment agent further contains a carbonate as said (D) component. The water treatment agent containing the said carbonate is advantageous at the point which can improve the removal power of a toxic substance more.

There is no restriction | limiting in particular as said carbonate, According to the objective, it can select suitably, For example, calcium carbonate, potassium carbonate, sodium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, potassium carbonate, ammonium carbonate, ammonium hydrogen carbonate, carbonate Magnesium, these hydrates, etc. are mentioned. Among these, calcium carbonate, potassium carbonate and sodium carbonate are preferable as the carbonate from the viewpoint of improving the ability to remove harmful substances. The said carbonate can be used individually by 1 type or in combination of 2 or more types.

There is no restriction | limiting in particular as an usage-amount of the said carbonate, Although it can select suitably according to the objective, For example, the total usage-amount of the said (A) component and the said (B) component (the said (A) component and the (B) component When only one of these is included, 1-50 mass% is preferable with respect to content of only one, and 5-35 mass% is more preferable. If the amount of use is within the above preferred range, it is advantageous in that the ability to remove harmful substances can be improved.

<(E) component>

The said (E) component is an aluminum compound.

It is preferable that the said water treatment agent contains an aluminum compound as said (E) component further. The water treatment agent containing the said aluminum compound is advantageous at the point which can improve the removal power of a toxic substance more.

There is no restriction | limiting in particular as said aluminum compound, According to the objective, it can select suitably, For example, aluminum hydroxide, aluminum oxide, etc. are mentioned. Moreover, about the water treatment agent of the said (4)-(7) aspect containing the said (B) component, what is contained in the sulfate in the said (B) component as said aluminum compound (aluminum sulfate, sodium aluminum sulfate, Potassium aluminum sulfate, etc.) shall be excluded. The said aluminum compound can be used individually by 1 type or in combination of 2 or more types.

There is no restriction | limiting in particular as a usage-amount of the said aluminum compound, Although it can select suitably according to the objective, For example, the total content of the said (A) component and the said (B) component (the said (A) component and the said (B) component) When it contains only one of these, 1-50 mass% is preferable with respect to content of only one, and 5-35 mass% is more preferable.

<Other ingredients>

Moreover, the water treatment agent of this invention is at least any one of the said (A) component and the said (B) component, Preferably, the said (C) component, the said (D) component, and the said (E) component It may consist of only at least one of and may contain the other component suitably.

There is no restriction | limiting in particular as said other components, It can select suitably according to the objective within the range which does not impair the effect of this invention, For example, pH adjusters, such as a calcium compound used as a raw material, an acid, an alkali, etc. And water-soluble alkaline earth metal salts.

There is no restriction | limiting in particular as the usage-amount of the said other components, According to the objective, it can select suitably.

Water-soluble alkaline earth metal salt

Here, although the said water-soluble alkaline earth metal salt may be contained in the water treatment agent of any aspect, Especially, the aspect (1)-(3) (in the said (A) component and said (B) component, said (A) It is preferable to be contained in the water treatment agent of the state containing only a component.

There is no restriction | limiting in particular as said water-soluble alkaline earth metal salt, According to the objective, it can select suitably, For example, calcium chloride, calcium nitrate, calcium nitrite, calcium iodide, calcium bromide, barium bromide, barium iodide, barium chloride, barium nitrate Barium nitrite, barium sulfide, barium hydroxide, barium acetate, strontium chloride, strontium bromide, strontium iodide, strontium hydroxide, strontium nitrate, strontium nitrate, strontium acetate, radium chloride, radium nitrate, radium bromide, etc. A substance having a binding property and capable of forming a precipitate with low solubility by binding with sulfate ions can be suitably used. The said water-soluble alkaline earth metal salt can be used individually by 1 type or in combination of 2 or more types. Here, water solubility shall be 1 g or more in solubility with respect to 100 g of water of 20 degreeC.

<Production, Formulation>

The water treatment agent of this invention, for example, at least any one of the said (A) component and the said (B) component, Preferably, the said (C) component, the said (D) component, and the said (E) It can manufacture by mixing at least one of a) component, and other components as needed. In addition, the said water treatment agent can be used also in any state, such as a block, a granular form, and powdery form. Granular and powdery water treatment agents can be produced by, for example, grinding. There is no restriction | limiting in particular, The grinding | pulverization method can be performed using a well-known apparatus, At least any one of the said (A) component and the said (B) component, Preferably, the said (C) component and the said (D The component and at least one of the above-mentioned (E) components and each of the other components may be pulverized before mixing, if necessary, and at least the above-mentioned (A) component and the (B) component At least one of the above-mentioned (C) component, the above-mentioned (D) component, and the said (E) component and other components as needed may be grind | pulverized after mixing.

Moreover, as said water treatment agent, at least any one of the said (A) component and the said (B) component, Preferably, at least the said (C) component, the said (D) component, and the said (E) component It is not limited only to the thing of the aspect which adds and uses the mixture which any other and other components were mixed previously as needed at once in water, For example, the said (A) component and the said (B) component At least any one of, preferably, the component (C), the component (D), and at least one of the component (E), and other components, if necessary, The thing of the aspect to be used may be sufficient.

<Use>

According to the water treatment agent of the present invention, harmful substances can be easily and efficiently removed from water containing harmful substances. Therefore, the water treatment agent of this invention can be used suitably for the water treatment method of this invention mentioned later, for example.

(Water treatment method)

The water treatment method of the present invention is characterized by using the above water treatment agent of the present invention.

<Target water>

The water to be treated in the water treatment method of the present invention (water to be treated) is not particularly limited as long as the water contains any harmful substance. For example, the manufacturing process of various products and the combustion gas And industrial wastewater generated from seyeon process and polluted soil purification process. There is no restriction | limiting in particular also as a hazardous substance to process, For example, heavy metals, such as selenium, copper, chromium, molybdenum, antimony, lead, arsenic, zinc, cadmium, nickel, manganese, iron, tin, cobalt, and boron , Fluorine, phosphorus and the like. In particular, the water treatment method of the present invention is suitable for water containing boron. The boron-containing water usually contains boron in the form of orthoboric acid (H ₃ BO ₄ ), but may include boron in a borate or other form, and as such boron-containing water, for example, in the glass industry or Wastewater, such as an electroplating industry, is mentioned. In addition, the water treatment agent of this invention can be used in the range whose pH of the water to be treated is 2-14, and can also be used even if other ions, such as chloride ion, coexist. In addition, since the water treatment agent is alkaline, the water containing harmful substances at the time of treatment usually becomes weakly alkaline. When the harmful substance-containing water is a strongly acidic solution, sodium hydroxide and calcium hydroxide can be added as necessary to obtain a weak alkaline property.

<Treatment with water treatment agent>

The water treatment method of this invention should just be able to contact the water treatment agent with water containing a hazardous substance, and there is no restriction | limiting in particular in the method. For example, after removing a harmful substance by adding a predetermined amount of the water treatment agent to the water containing the harmful substance, the water treatment agent is separated by solid-liquid separation (addition method), or a packed column filled with the water treatment agent. And the like (recharging method) for removing harmful substances by passing water through. In either method, it is possible to efficiently remove harmful substances. In addition, before the harmful substance-containing water comes into contact with the water treatment agent, a pretreatment step such as a pH adjustment step may be provided.

Processing condition of addition method

There is no restriction | limiting in particular in the addition amount of the water treatment agent in an addition method, It is suitably determined by the density | concentration of the harmful substance of a hazardous substance containing water.

There is no restriction | limiting in particular as a addition method of the water treatment agent in an addition method, For example, the method of adding to the flow paths, such as piping of a water treatment installation, a water storage tank, etc. are mentioned.

There is no restriction | limiting in particular in the processing time in an addition method, For example, it can be made into 10 minutes or more, Preferably it is 30 minutes or more. Moreover, you may not need to stir during processing. When intersecting, the apparatus, the operation, and the like are not particularly limited, and a conventionally known apparatus and operation can be used.

Solid-liquid separation after the noxious substance treatment in an addition method can be performed using a normal apparatus by means, such as decantation, filtration, and centrifugation. The water treatment agent of the present invention is excellent in cohesiveness (sedimentation) in, for example, the aspect (4) to (7) containing at least the above-mentioned (B) component, so that solid-liquid separation can be easily performed without adding a coagulant. Although it can carry out, you may add a flocculant further as needed. The flocculant to be used is not particularly limited, and conventionally known materials can be used, and examples thereof include anionic polymer flocculant, nonionic polymer flocculant, cationic polymer flocculant, amphoteric polymer flocculant, and inorganic flocculant. have.

By carrying out the above-mentioned solid-liquid separation, the water treatment agent after the water treatment can be easily recovered, and the recovered water treatment agent can be used for removing harmful substances in the water containing harmful substances again, for example, after proper treatment. Specifically, the heat treatment obtained by subjecting the insoluble substance (water treatment agent) to water recovered after the water treatment to be used again can be used to remove harmful substances in the hazardous substance-containing water. This heat treated product can be reused to remove harmful substances in the harmful substance-containing water, as appropriate, up to the amount of saturated harmful substances adsorbed.

The heat treatment of the insoluble matter (water treatment agent) in water, which is recovered after the water treatment, is preferably performed at a temperature of 60 ° C. or higher, more preferably 100 ° C. or higher for 10 minutes or more, preferably 30 minutes or more. More preferred. Although there is no restriction | limiting in particular as an upper limit of the said heating temperature, 1600 degrees C or less is preferable. The upper limit of the heating time is not particularly limited, but is preferably within 24 hours.

In this heat treatment, weight reduction occurs. For example, it is preferable that the weight reduction rate is 15% or more, more preferably 20% or more, and even more preferably 25% or more by the heat treatment. In addition, the said weight loss rate is taken as the ratio (%) of the weight loss after heat processing with respect to the dry weight of an insoluble substance in collect | recovered water.

The heat treatment may be carried out under an atmospheric pressure environment or may be carried out under reduced pressure. In addition, heat treatment may be performed after drying the recovered material, or heat treatment may be performed without drying. There is no restriction | limiting in particular also as an apparatus used for the said heat processing, For example, it can carry out using a well-known hot air dryer, an electric furnace, a thermostat, a fluidized bed dryer, a vacuum dryer, a spray dryer, a rotary kiln, etc.

Treatment condition of the filling method

There is no restriction | limiting in particular in the filling amount of the water treatment agent to the packed tower in a filling method, It is suitably determined by the size of a packed tower, the water flow rate of a toxic substance containing water, etc.

There is no restriction | limiting in particular in the filling tower in a filling method, A well-known thing can be used and the number in particular is not restrict | limited, For example, only one base of a charging tower may be used, and the sufficient tower of a plurality of machines is used. It can also be used in series.

The inflow of the water treatment agent into the packed bed in the filling method may be either upflow or downflow, and the space velocity SV is not particularly limited, but is, for example, 1 to 120 hr ⁻¹ , preferably 5 to 50 hr ⁻¹ . can do.

In addition, the water treatment system recovered from the packed column can be used to remove harmful substances in the water containing harmful substances again after proper treatment.

<Use>

According to the water treatment method of the present invention, harmful substances can be efficiently removed with a small amount of chemical agent (water treatment agent amount) by a simple apparatus and operation. Therefore, the water treatment method of the present invention can be suitably used, for example, for removing toxic substances in various industrial wastewaters.

Example

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to these Examples at all.

[Examples 1 to 62 and Comparative Examples 1 to 12]

Each water treatment agent of Examples 1-62 and Comparative Examples 1-12 was manufactured by mixing each component shown to the following Tables 1-13. In addition, in Tables 1-13, "addition concentration" shows the density | concentration (mass%) of each component with respect to the process object water. In addition, in Tables 1-13, "A-1"-"A-5", "B-1"-"B-7", "b-1"-"b-6", and "C-1"- The detail of each component of "C-7", "D-1"-"D-3", "E-1"-"E-2" is as showing in Table 14.

(1) Evaluation of the ability to remove harmful substances

For the obtained water treatment agents of Examples 1 to 62 and Comparative Examples 1 to 12, harmful substances were calculated by calculating the harmful substance removal rate when the hazardous substance-containing water (water to be treated) was treated under the conditions shown in Tables 1 to 13 below. Material removal power was evaluated. Specifically, 50.0 g of harmful substance-containing water (water to be treated) and a predetermined amount of water treatment agent were added to a 75 ml commercial mayonnaise bottle, and the mixture was left to stand for 10 minutes after being stirred vigorously for a predetermined time. After the treatment solution was filtered and diluted with pure water as needed, an ICP emission spectrometer (Parkinelma Japan Co., Ltd., optima5300DV) or an ion electrode (Thermo-Electron Co., Ltd., Orion370) was used. Hazardous substance concentration was measured. The harmful substance concentration was measured using the ICP emission spectrometer with respect to boron, phosphoric acid, cadmium, chromium, manganese, cobalt, nickel, zinc, copper, iron, and lead. About fluorine, it measured using the said ion electrode. The harmful substance removal rate was computed by following formula (1). In addition, the closer to 100% of the harmful substance removal rate indicates that the harmful substance removal ability is higher. In this invention, 50% or more was made into the pass level of a toxic substance removal rate. The results are shown in Tables 1 to 13.

[expression]

Hazardous Substance Removal Rate (%) = (1-C ₁ / C ₀ ) × 100. Formula (1)

C ₁ : Hazardous substance concentration after treatment (mg / L)

C ₀ : Initial concentration of harmful substances before treatment (mg / L)

(2) Evaluation of degree (second drop of sulfate ion concentration in the water after the treatment) of secondary pollution

In addition, the water treatment agents of Examples 1 to 62 and Comparative Examples 1 to 12 were subjected to water treatment in the same manner as in the above (1), and the treated solution was filtered and diluted with pure water as needed, followed by an ICP emission spectrometer ((Note) The concentration of sulfate ion in the water after treatment was measured using optima5300DV) manufactured by Parkin Elma Japan. The results are shown in Tables 1 to 13. In addition, "ND" in a table | surface shows that it is less than a lower limit of detection.

(3) Evaluation of cohesiveness (sedimentation)

Moreover, about the water treatment agents of Examples 1-62 and Comparative Examples 1-12, the cohesiveness (sedimentation) after removal of a hazardous substance was evaluated as follows. To a 75 ml commercial mayonnaise bottle, 50.0 g of harmful substance-containing water (water to be treated) and a predetermined amount of water treatment agent were added, and after stirring vigorously for a predetermined time, it was left standing. After 10 minutes, the height of the gas-liquid interface and the height of the solid-liquid interface were measured, and the aggregation rate (sedimentation rate) was calculated by the following formula (2) (see Fig. 1). In addition, although the cohesion rate near 100% shows that cohesion is favorable, when the coagulation rate is 100%, it shows that the water treatment agent melt | dissolved in the water to process, and it does not become an index of what is excellent in cohesion (Comparative example) 8, 9, 11). The results are shown in Tables 1 to 13.

[expression]

Cohesion rate (%) = (1-b / a) × 100... Formula (2)

a: height of the gas-liquid interface (mm)

b: height of the solid-liquid interface (mm)

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

TABLE 7

TABLE 8

TABLE 9

TABLE 10

TABLE 11

TABLE 12

TABLE 13

TABLE 14

In addition, in Table 14, the synthesis | combining method of each "synthetic product" is as follows.

<Synthesis method of A-1>

In 1 liter of water, 6.3 g of aluminum sulfate and 8.9 g of calcium hydroxide were mixed, the pH was adjusted to 12 with sodium hydroxide, and then stirred at room temperature for 1 hour and aged for 24 hours to react. After the reaction was completed, the precipitate was filtered off and dried under reduced pressure at room temperature to obtain an insoluble solid. This solid was analyzed by wide-angle X-ray diffraction measurement to confirm that it was ettringite. 150 g of this etrinite was heat-processed at 500 degreeC for 5 hours using the high temperature electric furnace (made by Yamato Scientific Co., Ltd., FP41), and 8.6g of A-1 was obtained. In addition, the weight reduction rate by heat treatment was 42.4%.

<Synthesis method of A-2>

In 1 liter of water, 6.3 g of aluminum sulfate and 8.9 g of calcium hydroxide were mixed, the pH was adjusted to 12 with sodium hydroxide, and then stirred at room temperature for 1 hour and aged for 24 hours to react. After the reaction was completed, the precipitate was filtered off and dried under reduced pressure at room temperature to obtain an insoluble solid. This solid was analyzed by wide-angle X-ray diffraction measurement to confirm that it was ettringite. 150 g of this ethringite was heated at 200 ° C. for 5 hours using a high temperature electric furnace (manufactured by Yamato Scientific Co., Ltd., FP41) to obtain 10.0 g of A-2. Moreover, the weight reduction rate by heat processing was 33.2%.

<Synthesis method of A-3>

In 1 liter of water, 6.3 g of aluminum sulfate and 8.9 g of calcium hydroxide were mixed, the pH was adjusted to 12 with sodium hydroxide, and then stirred at room temperature for 1 hour and aged for 24 hours to react. After the reaction was completed, the precipitate was filtered off and dried under reduced pressure at room temperature to obtain an insoluble solid. This solid was analyzed by wide-angle X-ray diffraction measurement to confirm that it was ettringite. 150 g of this ethringite was heat-processed at 150 degreeC for 5 hours using the high temperature electric furnace (manufactured by Yamato Scientific Co., Ltd., FP41), and 10.8 g of A-3 was obtained. In addition, the weight reduction rate by heat treatment was 28.0%.

<Synthesis method of A-4>

6.3 g of aluminum sulfate and 8.9 g of calcium hydroxide were mixed in 1 L of water, the pH was adjusted to 12 with sodium hydroxide, and then stirred at room temperature for 1 hour and aged for 24 hours to react. After the reaction was completed, the precipitate was filtered off and dried under reduced pressure at room temperature to obtain an insoluble solid. This solid was analyzed by wide-angle X-ray diffraction measurement to confirm that it was ettringite. 150 g of this ethringite was heated at 100 ° C. for 5 hours using a high temperature electric furnace (manufactured by Yamato Scientific Co., Ltd., FP41) to obtain 12.2 g of A-4. Moreover, the weight loss rate by heat processing was 18.6%.

<Synthesis method of A-5>

In 1 liter of water, 6.3 g of aluminum sulfate and 8.9 g of calcium hydroxide were mixed, the pH was adjusted to 12 with sodium hydroxide, and then stirred at room temperature for 1 hour and aged for 24 hours to react. After the reaction was completed, the precipitate was filtered off and dried under reduced pressure at room temperature to obtain an insoluble solid (A-5). This solid A-5 was analyzed by wide-angle X-ray diffraction measurement, and it was confirmed that it was ethringite.

<Synthesis method of B-1 (= C-1), B-6 (= C-6)>

41.2 g of aluminum hydroxide and 58.8 g of calcium hydroxide were mixed in 1 L of water, stirred at 100 ° C. for 12 hours, aged for 24 hours, and allowed to react. After the reaction was completed, the precipitate was filtered off and dried at room temperature to obtain 81.7 g of an insoluble solid (B-6). This solid B-6 was baked at 500 degreeC for 3 hours, and 59.5 g of solid (B-1) was obtained. Each product was analyzed by wide-angle X-ray diffraction measurement, and it was confirmed that solid B-6 was Ca ₃ Al ₂ O ₆ .6H ₂ O and solid B-1 was Ca ₁₂ Al ₁₄ O ₃₃ .

<Synthesis method of B-2 (= C-2)>

4.1 g of aluminum hydroxide and 5.9 g of calcium hydroxide were mixed, placed in a crucible, and heated at 1400 ° C. for 7 hours using a calcining furnace (manufactured by Motoyama Co., Ltd., SUPER BURN) to obtain 7.0 g of a solid (B-2). This solid B-2 was analyzed by wide-angle X-ray diffraction measurement, and it was confirmed that it was Ca ₃ Al ₂ O ₆ .

<Synthesis method of B-3 (= C-3)>

4.1 g of aluminum hydroxide and 5.9 g of calcium hydroxide were mixed, placed in a crucible, and heated at 1380 ° C. for 5 hours using a kiln (manufactured by Motoyama Co., Ltd., SUPER BURN) to obtain 7.1 g of a solid (B-3). This solid B-3 was analyzed by wide-angle X-ray diffraction measurement, and it was confirmed that it was a mixture of Ca ₃ Al ₂ O ₆ / Ca ₁₂ Al ₁₄ O ₃₃ .

<Synthesis method of B-5 (= C-5), B-7 (= C-7)>

14.1 g of aluminum nitrate hexahydrate and 26.6 g of calcium nitrate tetrahydrate were mixed in 1 L of water, the pH was adjusted to 12 with sodium hydroxide, and the mixture was stirred at room temperature for 1 hour to react. After the reaction was completed, the precipitate was filtered off and dried at room temperature to obtain 10.9 g of an insoluble solid (B-5). This solid B-5 was analyzed by wide-angle X-ray diffraction measurement, and it was confirmed that it was Ca ₂ Al ₂ O ₅ .6H ₂ O. This solid B-5 was calcined at 500 ° C. for 3 hours to obtain 7.8 g of solid (B-7).

From the results of Tables 1 to 13, (A) calcium sulfoaluminate hydrate and / or a substance obtained by heat treatment of calcium sulfoaluminate hydrate, and (B) calcium aluminate and / or calcium aluminate were heated. It can be seen that the water treatment agents of Examples 1 to 62, which contain at least one of a substance obtained by treatment and a mixture of sulfates, have a high removal rate of harmful substances and can efficiently remove harmful substances with a small amount of chemicals. there was.

Among them, the water treatment agents of Examples 7 to 23 containing a mixture of (B) calcium aluminate and / or calcium aluminate by heat treatment with a sulfate, in addition to a high removal rate of harmful substances, in addition to the coagulation rate As a result, these water treatment agents can efficiently remove harmful substances with a small amount of chemical agent, and in order to recover the water treatment agent after treatment, they are left standing for a long time until an expensive flocculant is added or aggregated (precipitated). It was found that it is not necessary to make it, and it is advantageous in that the treated water and the water treatment agent after the treatment can be easily separated. (In addition, the aspect of aggregation after the water treatment of the water treatment agent of Example 7 is shown on the left side in FIG. .. Among these, in particular, (B) a mixture of a substance obtained by heat treatment of calcium aluminate and / or calcium aluminate and sulfate, The water treatment agents of Examples 7 to 12 and 17 to 23 using calcium sulfate and hydrates thereof as salts have high removal rate of harmful substances and high aggregation rate, and also have low concentration of sulfate ion in water after treatment. The water treatment agent was found to be able to efficiently remove harmful substances with a small amount of chemical agent, to be advantageous in separating the treated water and the water treatment agent after treatment of the hazardous substance, and also to reduce the secondary contamination by sulfate ions.

Furthermore, the substance obtained by heat-processing (A) calcium sulfoaluminate hydrate and / or a calcium sulfoaluminate hydrate, and the substance obtained by heat-treating (C) calcium aluminate and / or calcium aluminate. In addition to the high removal rate of harmful substances, in addition to the high removal rate of harmful substances, the water treatment agents containing Examples 24 to 34 also have low concentrations of sulfate ions in the water after treatment. Therefore, these water treatment agents can efficiently remove harmful substances in a small amount of chemicals. In addition, it was found that secondary pollution by sulfate ions can be reduced.

In addition, all of the water treatment agents of Examples 1 to 62 can be manufactured at a much lower cost than commercially available chelating resins, and are advantageous from the viewpoint of economic efficiency, in that harmful substances can be removed very efficiently.

On the other hand, the substance obtained by heat-processing (A) calcium sulfoaluminate hydrate and / or calcium sulfoaluminate hydrate, and the substance obtained by heat-processing (B) calcium aluminate and / or calcium aluminate. In Comparative Examples 1 to 12, which contained neither a mixture of nor a sulfate, the removal rate of the harmful substances was remarkably low, and the use as a water treatment agent for the purpose of removing the hazardous substances was impossible.

Example 63 (Coexistence)

14.1 g of aluminum nitrate hexahydrate, 26.6 g of calcium nitrate tetrahydrate, and 4.0 g of sodium sulfate were mixed in 1 L of water, and after adjusting the pH to 12, the mixture was stirred for 1 hour and aged for 24 hours to react. After the reaction was completed, the precipitate was filtered off and dried at room temperature to obtain an insoluble solid. The solid was analyzed by wide-angle X-ray diffraction measurement to confirm that it was a coexistence of ethringite, which is a kind of calcium sulfoaluminate hydrate, and calcium aluminate (Ca ₂ Al ₂ O ₅ .6H ₂ O). In addition, the X-ray diffraction chiato of the coexistence of ethringite and calcium aluminate is shown in FIG. In addition, the wide-angle X-ray diffraction measurement was measured with the light source Cu-K-ALPHAl / 40 microseconds / 20 microseconds, and the scanning speed of 4.0 degrees / min using the X-ray-diffraction apparatus (RINT2100 made from Rigaku Corporation).

1 mass% of the solid was added to boron-containing water (boron concentration 112 mg / L) at an initial pH of 12, and the mixture was stirred for 5 hours and subjected to water treatment. The removal rate of boron as a harmful substance was 55.2%, and sulfuric acid in water after treatment It was found that the ion concentration is lower than the lower limit of detection, and boron can be removed efficiently with a small amount of medicine and with little secondary contamination. The aggregation rate at this time was 10%.

Example 64 Coexistence Heat Treated Products

After heating the solid obtained in Example 63 at 500 degreeC for 5 hours, 1 mass% was added to boron-containing water (boron concentration 112 mg / L) of the initial pH 12, and it stirred for 5 hours, and water treatment was performed, The removal rate of boron, which is a substance, was 98.5%, and the concentration of sulfate ion in water after treatment was 6 mg / L, and it was found that boron can be removed efficiently with a small amount of medicine and less secondary contamination. The aggregation rate at this time was 5%.

Example 65 (Combinant Heat Treatment)

14.1 g of aluminum nitrate hexahydrate, 26.6 g of calcium nitrate tetrahydrate, and 5.6 g of sodium sulfate were mixed in 1 L of water, and after adjusting the pH to 12, the mixture was stirred for 1 hour and aged for 24 hours to react. After the reaction was completed, the precipitate was filtered off and dried at room temperature to obtain an insoluble solid. The solid was analyzed by wide-angle X-ray diffraction measurement, and it was confirmed that it was a coexistence of ethringite, which is a kind of calcium sulfoaluminate hydrate, and calcium aluminate (Ca ₂ Al ₂ O ₅ .6H ₂ O).

After heating the solid at 500 ° C. for 5 hours, 1 mass% was added to boron-containing water (boron concentration 112 mg / L) at an initial pH of 12, and the mixture was stirred for 5 hours and subjected to water treatment. It was found that the concentration of sulfate ion in water after 97.1% and treatment was 19 mg / L, and boron was removed efficiently with a small amount of medicine and with less secondary contamination. The aggregation rate at this time was 6%.

Example 66 (Evaluation of Addition Order)

0.4 mass% of b-1 (calcium sulfate, dihydrate) was added to boron-containing water (boron concentration 102 mg / L, pH 9), and after stirring for 30 minutes, 0.4 mass of B-1 (Ca ₁₂ Al ₁₄ O ₃₃ ) % Was added. Thereafter, the mixture was stirred for 5 hours, and boron treatment was performed. The boron removal rate at this time was 87.1%, and the boron removal ability improved compared with the case where both components were added simultaneously (Example 7). Moreover, the sulfate ion concentration in the water after the treatment was 18 mg / L, the secondary contamination was small, the aggregation rate was 72%, and the cohesion was also good.

Comparative Example 13 (chelating resin method)

1 mass% of commercially available chelate resin diaion CRB05 (manufactured by Mitsubishi Chemical Corporation) was added to boron-containing water (boron concentration 101 mg / L, pH 9) for boron removal, and stirred for 5 hours, followed by water treatment. The boron removal rate was 39.1%, the boron concentration was slightly reduced, and the concentration of sulfate ion in the water after treatment was also lower than the lower limit of detection. However, commercially available chelating resins are very expensive, and economical efficiency can effectively remove boron. I can't. The aggregation rate at this time was 95%.

Comparative Example 14 (chelating resin method)

1 mass% of commercially available chelate resin diaion CRB05 (manufactured by Mitsubishi Chemical Corporation) was added to boron-containing water (boron concentration 106 mg / L, pH 12) for boron removal, stirred for 5 hours, and water treatment was performed. The boron removal rate was 38.9%, the boron concentration was slightly reduced, and the concentration of sulfate ion in the treated water was also below the lower limit of detection. However, commercially available chelating resins are very expensive, and considering the economical efficiency, boron can be efficiently removed. none. The aggregation rate at this time was 95%.

Comparative Example 15 (Agglomeration Precipitation Method)

0.5 mass% of aluminum sulfate 18-hydrate and 0.5 mass% of calcium hydroxide were added to boron containing water (boron concentration 114 mg / L, pH 9), and it stirred for 5 hours, and water-processed, boron removal rate is 20.0%, Although the boron concentration in water was slightly reduced, the effect was low, and the sulfate ion concentration was also 1406 mg / L, and there was a possibility of secondary contamination. Moreover, the aggregation rate was 39% and cohesion was not enough.

[Comparative Example 16 (When calcium sulfate was added in a system in which calcium aluminate hydrate was formed in water)]

0.5 mass% of sodium aluminate, 0.5 mass% of calcium hydroxide, and 0.5 mass% of calcium sulfate dihydrate are simultaneously added to boron containing water (boron concentration 105 mg / L, pH 9), and it stirs for 5 hours, and boron treatment is performed. It was. The boron removal rate was 20.1% and the boron concentration was slightly reduced, but the effect was low. In addition, the concentration of sulfate ion in water after treatment is 1428 mg / L, and there is a possibility of secondary contamination. The aggregation rate at this time was 72%.

Example 67 Evaluation of Reuse of Water Treatment Agent by Heating Treatment

After the boron-containing water was treated under the conditions shown in Example 1, filtration was performed to separate water having a sufficiently low boron concentration and a water treatment agent insoluble in water. The material recovered by filtration was vacuum dried at room temperature for 2 days and then heated to 150 ° C. for 5 hours. The weight reduction rate at this time was 27.1%. 0.8 mass% of the material obtained by this heat drying was added to boron-containing water (boron concentration 106 mg / L, pH 12), stirred for 5 hours, and water treatment was performed. At this time, the boron removal rate was 76.4%, the boron concentration was reduced, and the effect was very high. Moreover, sulfate ion concentration was 656 mg / L, and the aggregation rate was 45%.

Example 68 Evaluation of Reuse of Water Treatment Agent by Heating Treatment

After the boron-containing water was treated under the conditions shown in Example 7, filtration was performed to separate water having a sufficiently low boron concentration and a water treatment agent insoluble in water. The material recovered by filtration was vacuum dried at room temperature for 2 days and then heated to 200 ° C. for 1 hour. The weight reduction rate at this time was 25.3%. 0.8 mass% of the material obtained by this heat drying was added to boron-containing water (boron concentration 104 mg / L, pH 12), stirred for 5 hours, and water treatment was performed. At this time, the boron removal rate was 72.9%, the boron concentration was reduced, and the effect was very high. Moreover, the sulfate ion concentration was 29 mg / L, the secondary contamination was small, the aggregation rate was 83%, and the cohesion was also good.

Example 69

1 mass% of the water treatment agents used in Example 1 were added to the spring water (boron concentration 76 mg / L) of the initial pH 7.2 which consists of components shown in Table 14, and it stirred for 5 hours, and performed water treatment. At this time, the boron removal rate was 95.0%, the boron concentration was reduced, and the effect was very high. Further, the sulfate ion concentration was 1250 mg / L, and the aggregation rate was 2%.

TABLE 14

Example 70

The water treatment agent used in Example 7 was added to the spring water (boron concentration 76 mg / L) of the initial pH 7.2 which consists of components shown in Table 14, and it stirred for 5 hours, and performed the water treatment. At this time, the boron removal rate was 95.1%, the boron concentration was reduced, and the effect was very high. Moreover, the sulfate ion concentration was 25 mg / L, the secondary contamination was also small, the aggregation rate was 70%, and the cohesion was also favorable.

Example 71

The water treatment agent used in Example 24 was added to the spring water (boron concentration 76 mg / L) of the initial pH 7.2 which consists of the component shown in Table 14, and it stirred for 5 hours, and performed the water treatment. At this time, the boron removal rate was 96.0%, the sulfate ion concentration was 13 mg / L, and it was found that boron can be removed efficiently with a small amount of medicine and with less secondary contamination. In addition, the aggregation rate was 5%.

Example 72 (addition method)

To the boron-containing water (boron concentration 118 mg / L, pH 12), 1 mass% of the water treatment agent used in Example 1 was added and stirred for 5 hours, followed by water treatment, followed by addition of an anionic polymer flocculant and stirring for 1 hour. It was. When left still after stirring, the water treatment agent settled, and when the boron and sulfate ion concentrations of the supernatant were measured, the boron removal rate was 85.0%, and it was found that boron can be efficiently removed with a small amount of medicine by simple apparatus and operation. . Moreover, the sulfate ion concentration in the water after treatment was 1204 mg / L.

Example 73 (Addition Method)

1 mass% of the water treatment agent used in Example 24 was added to boron containing water (boron concentration 116 mg / L, pH10), and it stirred for 5 hours, and after performing water treatment, the anionic polymer coagulant was added and stirred for 1 hour. . If left still after stirring, the water treatment agent precipitates, and if the boron and sulfate ion concentrations of the supernatant are measured, the boron removal rate is 97.8%, and the sulfate ion concentration in the water after treatment is 10 mg / L. It can be seen that boron can be removed efficiently and in a small amount of secondary contamination.

Example 74 (Charging Method)

When 15 g of the water treatment agent used in Example 1 was charged and 100 ml of boron-containing water (boron concentration 112 mg / L, pH 12) was introduced under the condition of SV15hr ⁻¹ , the boron removal rate was 87.5%, and the device was simple to operate and operate. As a result, it has been found that boron can be removed efficiently with a small amount of the drug. Moreover, the sulfate ion concentration in the water after treatment was 1159 mg / L.

Example 75 Filling Method

When 15 g of the water treatment agent used in Example 24 was charged and 100 ml of boron-containing water (boron concentration 112 mg / L, pH 12) was introduced under the conditions of SV15hr ⁻¹ , the boron removal rate was 97.5%, and sulfate ion in water after treatment. It was found that the concentration was below the lower limit of detection, and by simple apparatus and operation, boron could be removed efficiently with a small amount of medicine and with less secondary contamination.

Example 76

Boron at an initial pH of 12 was a water treatment agent in which A-1 (a material obtained by heating a Ca ₆ Al ₂ (SO ₄ ) ₃ (OH) .26H ₂ O)) and barium chloride dihydrate were mixed at a mass ratio of 80:20. When 1 mass% was added to the contained water (boron concentration 104 mg / L) and stirred for 5 hours, water treatment was performed. As a result, the boron removal rate was 92.1%, and the concentration of sulfate ion in water after the treatment was less than the lower limit of detection. Goodly, it was also found that boron could be removed with less secondary contamination. The aggregation rate at the time of the knee was 6%.

The water treatment agent and the water treatment method of the present invention, for example, aimed at satisfying a drainage standard for each hazardous substance, which is very useful for removing hazardous substances in various industrial wastewater.

Claims (6)

At least any one of following (A) and (B) is contained, The water treatment agent characterized by the above-mentioned. (A) A substance obtained by heat treating calcium sulfoaluminate hydrate and / or calcium sulfoaluminate hydrate. (B) A mixture of a substance obtained by heat treatment of calcium aluminate and / or calcium aluminate and a sulfate The method of claim 1, (A) A water treatment agent containing a substance obtained by heat treating calcium sulfoaluminate hydrate and / or calcium sulfoaluminate hydrate, and further comprising (C) calcium aluminate and / or calcium aluminate. A water treatment agent, comprising a substance obtained by mixing. The method according to claim 1 or 2, Moreover, (D) the water treatment agent containing carbonate. The method according to any one of claims 1 to 3, Furthermore, the water treatment agent containing (E) aluminum compound. The water treatment agent containing the substance obtained by heat-processing the material insoluble in water collect | recovered after performing a water treatment using the water treatment agent in any one of Claims 1-4. The water treatment method as described in any one of Claims 1-5 using the water treatment method.

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