JPH10101452A - Porous ceramic having amorphous pore surface and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a porous ceramic having an amorphous pore surface, excellent in removing performances of harmful and contaminated components in various drain and waste liquor treatment, by molding a mixture of clay, a pore-forming material and water, drying and heating and baking the dried molded product under specific conditions. SOLUTION: In this method for producing a porous ceramic by mixing clay with a pore-forming material and water, molding the mixture into a proper shape, drying and heating and backing the dried molded product at 1,200-1,500 deg.C, the molded product is maintained at 600-800 deg.C for 3-7 hours in the heating process. In this case, preferably the molded product is heated from a normal temperature to 600-800 deg.C for 5-15 hours. Preferably, the molded product is baked at 1,200-1,500 deg.C for 4-8 hours. The objective porous ceramic having an amorphous pore surface is obtained by this method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous ceramic having an amorphous pore surface useful for the treatment of various waste water and waste liquids, such as photographic development waste liquids and organochlorine compounds, which are currently being treated, and the production thereof. The present invention relates to a method and a method for treating various wastewater and wastewater using the method.

[0002]

2. Description of the Related Art Various methods for treating wastewater using porous ceramics have been known. For example, Japanese Patent Application Laid-Open No. 58-205516 by the present inventors discloses that a mud-like molded product obtained by adding a feldspar and an alumina powder to a mixture of silica stone and clay, adding sawdust and water and kneading the mixture is 1100. Chemicals fired at ~ 1200 ° C,
A tube-type ceramic cartridge filter excellent in selective removal of heavy metals and the like is described.

[0003] Japanese Patent Publication No. 1-60317 by the present inventors discloses a treatment layer in which a filtration layer made of a layer of sand or gravel is provided at the bottom of a treatment tank, and porous ceramic granules are laminated thereon. And an apparatus for treating wastewater such as sewage, in which an air diffuser is provided on the upper surface of the treatment layer and the lower surface of the filtration layer.

[0004] Japanese Patent Application Laid-Open No. 61-13649 by the present inventors.
In Japanese Patent Publication No. 0, a filter medium made of porous ceramic granules filled in a porous material such as a net is provided at intervals at a position transverse to the flow direction of the wastewater in the aeration tank. An aerated wastewater treatment apparatus is described.

[0005] Japanese Patent Publication No. 42758/1994 by the present inventors discloses that a porous material such as a net is filled at intervals at a position crossing the direction of flow of wastewater in an aeration tank. An aeration tank in which a filter medium made of porous ceramic granules is erected, and a filtration layer made of a layer of sand or gravel is provided at the bottom of the aeration tank which is connected to the aeration tank by a pipe. Providing a treatment layer in which ceramic granules are laminated,
An aeration type advanced wastewater treatment apparatus comprising a treatment tank having an air diffuser disposed on an upper surface of the treatment layer and a lower surface of the filtration layer is described.

Japanese Patent Publication No. 2-1558 discloses that wastewater such as household wastewater, industrial wastewater, food processing wastewater, etc. is mainly used for biological treatment in a treatment medium mainly composed of porous ceramics and wood chips. A method of processing is described.

The inventors of the present invention have published Japanese Patent Publication No. 63-66247.
In Japanese Patent Application Laid-Open Publication No. H10-157, there is described a method for treating emulsifying oil-containing wastewater using a filter device by filling a cylindrical body with a mixture of porous ceramics and activated carbon as a filter material.

[0008] JP-A-60-26158 by the present inventors
No. 6 discloses a method of removing metals, metal ions and organochlorine compounds from drinking water such as tap water using a filter provided with an intermediate layer made of a layer of activated carbon between porous ceramic layers. Have been described.

Further, Japanese Patent Application Laid-Open No.
Japanese Patent No. 91473 discloses a method for producing porous ceramics used for the treatment of waste water and waste liquid. The method includes adding a pore-forming material to a slurry obtained by adding and mixing water to a clay mineral powder, drying and calcining the porous ceramic. In the method for producing, a method for producing a porous ceramic, wherein the pore-forming material is subjected to a pretreatment for binding a metal powder or an organometallic compound to the pore surface, and firing is performed in air or a nitrogen atmosphere. Is described.

[0010]

However, the above method and the conventionally known porous method are used for the treatment of various wastewater and wastewater such as wastewater containing an organic chlorine compound such as tetrachloroethylene and trichloroethane, the treatment of which is a problem at present. Even with the use of ceramics, it was not possible to completely remove harmful and contaminants in wastewater and wastewater.

According to the description of the above-mentioned JP-A-61-291473, a porous ceramic is manufactured by raising the temperature of a dried molded body and firing it at about 1200 to 1500 ° C. for one hour. But it is 1200 ~ 15
When the temperature is increased in a short time by an electric furnace up to 00 ° C. and baked for about 1 hour, the obtained ceramic is entirely homogeneous, its pore surface is not amorphous, and its compressive strength is high. Ceramics with large variations and low compressive strength tend to be pulverized, and when used in a wastewater / wastewater treatment column, clogging occurs, making it difficult to use for a long time. When used, the ability to remove harmful and contaminant components was insufficient, and there was difficulty in long-term use, and it could not be said to be practical.

[0012]

Means for Solving the Problems Accordingly, the present inventors have:
At present, these harmful and polluting substances in wastewater and wastewater containing P (phosphorus), N (nitrogen), organochlorine compounds such as tetrachloroethylene, and heavy metals such as hexavalent chromium and lead are treated in Japan. Of water quality environmental standards, and can be removed to almost none, and intensively researched to develop practical porous ceramics that can withstand long-term use. When we made porous ceramics whose surface and pore surface were different in composition and the pore surface was amorphous, we overturned the conventional knowledge of how to make The present inventors have found that ceramics are effective and practical for treating various wastewater and wastewater, and have completed the present invention.

That is, according to the present invention, clay, a pore-forming material, and water are mixed, molded into an appropriate shape, and dried, and the temperature of the dried molded body is adjusted by self-burning of the pore-forming material in the molded body. After raising the temperature from room temperature to 600 to 800 ° C. over 5 to 15 hours, preferably about 10 hours, maintain the temperature of the molded body at 600 to 800 ° C. for 3 to 7 hours, preferably about 5 hours, Next, the temperature is raised to 1200 to 1500 ° C., and the resultant is baked at this temperature for 4 to 8 hours, desirably about 6 hours, and then subjected to a crusher treatment after cooling. And a method for treating wastewater and wastewater using the same.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The term "clay" used in the present invention has the property of exhibiting tackiness and plasticity when water is added, and having a property of becoming hard when dried, and most of which are mainly composed of silicate minerals. , But may contain other inorganic components such as calcium, magnesium, sodium, and potassium as needed.

"Pore forming material" used in the present invention includes materials derived from plants such as sawdust, wood chips, peaches, wheat straw, bran, bark (tree bark), plastic chips, granular absorbent polymers, hydrogencarbonate. Any material that generates a gas by heating, such as sodium, can be used, but sawdust and wood chips do not generate a sudden gas at the natural stage, and the structure of porous ceramics whose pore surface is amorphous Is desirable from the viewpoint of forming stably.

As the "water" used in the present invention, tap water is usually used, but seawater can also be used when the clay mineral has a small alkali content. When water is contained in other raw materials such as clay and pore-forming material, the water can be used instead.

In the present invention, the "kneading" of the clay, the pore-forming material and the water is carried out by kneading the three components in an appropriate order with a kneading machine such as a mortar cement mixer until the mixture becomes uniform. The mixing ratio of these components may be any ratio as long as the porous ceramics having a pore surface of the present invention can be obtained. From the viewpoint of the purpose of adsorption to the smooth portion, a mixture of clay 2: water 3.2: pore-forming material 6.76 (parts by weight, the same applies hereinafter) is desirable, but not limited thereto. After mixing, it is molded into an appropriate shape such as a brick shape or a disc shape so as to facilitate firing.

The "drying" after molding in the present invention is usually carried out by allowing the mixture to stand at room temperature until the water content reaches 40%, but it can also be carried out by ventilation drying using a burner or the like. The drying is not limited to drying.

In the present invention, "heating" and "firing"
Electric furnaces, kilns made of refractory bricks, kilns, etc. can be used as long as they can heat and fire the molded body after drying, but mass production of uniform ceramic products at once From the standpoint of the ability to do so, a kiln or kiln is preferred.

In the present invention, the molded product after firing can be used as it is as a block type or cartridge type filter, but when it is used by filling it in a column or the like, a crusher (crushing) treatment is usually used. Will be applied. For the crusher treatment, any type of ordinary pulverizer such as a roll type can be used, but in order to reduce the ratio of powdery ceramics that are not suitable for use in a column or the like, the present inventors have set forth the present invention. It is desirable to use a roll and a roll-type crusher in which the narrowest portion of the roll is adjusted to 10 to 30 mm.

Next, the most important "heating" and "firing" steps in producing the porous ceramics having pore surfaces according to the present invention will be described. First, the temperature of the molded body dried after molding is gradually increased from room temperature to 600 to 800.
C., preferably to 800.degree. By adopting such a slow heating process, the properties of the ceramic after sintering maintain a shape almost the same as that at the time of manufacturing the molded body, thereby forming sufficient continuous pores and ensuring sufficient processing with the object to be processed. It has a reaction part.

On the other hand, a conventional heating method which does not employ this slow heating step, such as an electric furnace as in the case of manufacturing porous ceramics described in the above-mentioned JP-A-61-291473. If the temperature rise method is used, which follows a rapid temperature rise process, the sintered ceramics will not have sufficient bonding between the crystal components, and at the same time, most of the pore surface formed in the ceramics will be covered with crystalline. The property that the resistance of the component to be processed when passing through the pores increases, and the component to be processed cannot sufficiently penetrate into the pores.
It has properties and contaminates wastewater and wastewater.
When applied to the removal of harmful components, the removal becomes inadequate and one that can withstand long-term use cannot be obtained.

The time required for the temperature to rise slowly from room temperature to 600 to 800 ° C. depends on the size and amount of the molded product, but is usually about 5 to 15 hours, preferably about 10 hours. Such heating can be controlled by adjusting the heating of the electric furnace, the kiln and the kiln, but if the pore-forming material is flammable, such as sawdust, it is rather dry-molded. It is particularly desirable to ignite one corner of the body by, for example, a burner or the like and to burn (self-burn) the combustible pore-forming material itself such as sawdust in the molded body. This method of controlling the product temperature by self-combustion is an epoch-making method first found by the present inventors in preparing porous ceramics. By adopting this method, heavy metals, high BOD wastewater, high COD It has been confirmed that a porous ceramics product having an amorphous pore surface for treating wastewater and wastewater such as wastewater can be obtained.

Thus, when the temperature of the dried molded article reaches 600 to 800 ° C. in 5 to 15 hours, combustibles such as sawdust in the molded article are ashed. At this stage, the temperature of 600 to 800 ° C. is increased for 3 to 7 hours by reheating, etc.
Preferably, it is maintained for about 5 hours. This step is an essential step for producing a porous ceramic having an amorphous pore surface according to the present invention.

By adopting this step, the alkali component in the clay gradually dissolves. As a result, the continuous pore surface of the porous ceramic becomes amorphous, and the strength of the porous ceramic after sintering increases. Without adopting this step, the temperature is reduced from room temperature to 12
If the temperature is rapidly increased to 00 to 1500 ° C., not only does the quality of the ceramic after firing vary, but also the performance of removing harmful and contaminants becomes insufficient.

For example, various compressive strengths are generated from high to low compressive strengths, and those with low strength become powdery in crusher treatment after firing.
If this powdery ceramic is packed into a column and then subjected to drainage / waste liquid treatment, the fluid resistance is large and clogging occurs immediately, making it practically impossible to use.

Next, the molded body heated at 600 to 800 ° C. for 3 to 7 hours takes 1200 to 1 hour over about 4 hours.
Raise the temperature to 500 ° C. In the present invention,
The reason why the sintering temperature varies from 1500 ° C. is that the amount of silicon dioxide and alkali in the clay is controlled to obtain a different active surface as a result of sintering. That is, when the alkali content in the clay is relatively large and sintering is easy, the temperature may be about 1200 ° C., but when the silicon content is high and sintering is difficult, firing at 1500 ° C. is good, and it is widely used. Firing at about 1250 ° C. is particularly preferred because it gives a usable ceramic.

When the temperature of the molded article reaches 1200 to 1500 ° C., it is fired at this temperature for 4 to 8 hours, preferably about 6 hours. If the calcination time at this temperature is about 1 hour as described in JP-A-61-291473, the surface of the continuous pore forming portion is insufficiently amorphized, and the porosity between the continuous pore forming portion and the surrounding particles is low. Because sufficient sintering strength cannot be obtained, only ceramics having the disadvantage of being easily broken can be obtained.

In the present invention, “amorphous pore surface” means that the surface of continuous pores formed inside the ceramic is
It refers to a combination of an amorphous material containing sodium silicate as a main component and crystalline materials (crystalline particles) such as sodium silicate and calcium oxide. The crystalline (crystalline particles) portion reacts with the component to be treated in the wastewater, but the amorphous portion does not contribute to the reaction.

However, the surface of the continuous pores was subjected to an accelerating voltage of 10 KV (secondary electron image) and 20 KV (reflected electron image) with a field emission scanning electron microscope Model S-4200 manufactured by Hitachi, Ltd. at a photographic magnification of 3000 times. As shown in FIG. 1, for example, in the conventional porous ceramics described in JP-A-61-291473, not only the surface 1 of the ceramic particles but also the surface of the continuous pores 2 were large. Part is covered with the crystalline particles 3,
Even if the flow 4 of the component to be treated reaches the ceramic particles and tries to pass through the continuous pores 2, the resistance is large, and the component to be treated cannot sufficiently flow into and penetrate into the pores 2.
While the surface 1 of the ceramic particles mostly contributes to the reaction with the component to be treated, in the surface amorphous porous ceramics of the present invention, as shown in FIG. Since the amorphous portion 5 exists, the flow of the component 4 to be treated reaches the ceramic particles and the resistance when passing through the continuous pores 2 is small, and the component to be treated can sufficiently flow and permeate into the pores 2. Thus, it is considered that not only the surface 1 of the ceramic particles but also the crystalline particles 3 existing in the pores 2 react with the component to be treated, and as a result, an excellent wastewater treatment effect can be achieved.

The types of wastewater and wastewater that can be treated using the porous ceramics having an amorphous pore surface according to the present invention are not particularly limited. Using porous ceramics whose pore surface is amorphous, waste liquid containing organic chlorine such as trichloroethane, swine wastewater with high organic nitrogen content, heavy metals such as lead, hexavalent chromium, nickel, mercury, zinc, cadmium and selenium Wastewater, wastewater from dairy factories, marine processing plants and slaughterhouses with high water-soluble protein content, rivers, lakes and marshes containing P and N that are considered difficult to remove, and pulp mills Its effects have been confirmed in wastewater, wastewater discharged from photographic development, and wastewater mixed with wax and detergent from a car wash.

The “activated carbon” used in the present invention may be any activated carbon produced by sufficiently carbonizing raw materials such as charcoal, coconut shell, coal char and other animal bones and blood.
The substance is not limited to those currently on the market as long as it is a substance made of porous carbonaceous material having a large specific surface area and an adsorption ability.

[0033]

The following examples are provided to clarify the features of the present invention, but the present invention is not limited to these examples. The number of parts in the examples represents parts by weight. Example 1 Production of Porous Ceramics with Amorphous Porous Surface 2 parts of clay (collected from the Seto district), 3.2 parts of water and 6.76 parts of sawdust were kneaded well using a kneading machine, and then vertically mixed. And the width and height are 250mm x 130mm x 110m respectively
m until the water content reaches 40%
It was dried at room temperature for three days and nights. The dried brick-like molded body was placed in a ceramic pot having a volume of 10 m ³ , and one corner thereof was ignited by a burner. After about 10 hours, the sawdust in the molded body was ashed by self-burning, and the product temperature had reached about 800 ° C. The incinerated molded body at a temperature of about 800 ° C. is heated (fired).
The temperature was kept at about 800 ° C. for about 5 hours.

Next, the molded body was heated for about 4 hours until the temperature of the molded body reached about 1250 ° C., and calcined at this temperature for about 6 hours. After the molded body after firing was cooled, it was taken out of the kettle.

At this time, the compressive strength of the molded product was measured with a compressive strength tester manufactured by Shimadzu Corporation.
A high compression strength range of ９9.5 kg / cm ² was obtained. Next, when this product was crushed by a crusher, 20% of the products had a diameter of 10 mm or more,
30% for 0 mm, 20% for 2 to 6 mm, 2
The powdery material having a size of not more than mm was obtained at a rate of 30%.

The physical properties of the porous ceramic obtained in Example 1 were as follows. Casa specific gravity 0.36 to 0.40 Porosity 86.7% Specific surface area 23 m ² / g

The composition of the above porous ceramics was changed to KE
VEX energy dispersive X-ray spectrometer SIGMA2
The composition of the whole ceramics was composed of silicon oxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, and the like. The composition of the active part of the pore surface is crystalline such as sodium silicate, calcium silicate, calcium oxide, magnesium oxide, and the composition of the inactive part of the pore surface is sodium silicate, silicon oxide, oxidized It was amorphous such as aluminum, potassium oxide and sodium oxide.

Further, the porous ceramic of the present invention comprises:
Compared to the composition of the entire ceramic and its outer surface,
The composition of the pore surface is rich in silicon-based components, and from the surface state by the electron micrograph, it can be seen that the porous ceramic of the present invention is a porous ceramic whose pore surface is amorphous.

Comparative Example 1 Production of Porous Ceramics by Conventional Method The same procedure as in Example 1 was carried out, except that the following heating and firing steps were employed. That is, the dried brick-like molded body adjusted in the same manner as in Example 1 was placed in an electric furnace, and the product temperature was almost linearly adjusted to 125.
Heated to 0 ° C. for 4 hours and fired at 1250 ° C. for approximately 1 hour.

The compression strength of the molded body after firing was measured with a compression strength measuring device manufactured by Shimadzu Corporation in the same manner as in Example 1, and it was 2.1 to 9.6 kg / cm ^2. And the ratio of low compressive strength was high. Next, this product was crushed by a crusher.
%, 10% for 6 to 10 mm, 20% for 2 to 6 mm, and 65% for 2 mm or less. Compared with Example 1, the ratio of powdery material was very high. Was.

The physical properties of the porous ceramics obtained in Comparative Example 1 were as follows. Casa specific gravity 0.4-0.52 Porosity 85.6-87.1% Specific surface area 18-38 m ² / g

When the composition of this porous ceramic was measured in the same manner as in Example 1, there was no significant difference in the composition of the entire ceramic, the composition of the active portion on the particle surface and the pore surface, and the composition of the non-active portion on the pore surface. .

When comparing the above various physical property values with those of Example 1, there is no difference in the overall composition and the composition of the outer surface. Unlike porous ceramics, which are amorphous, most of the pore surface is homogeneous crystalline composed of silicon oxide, calcium oxide, etc., the crystal grains are large, and the bonding between the crystal grains is insufficient. It does not have a structure in which active crystal particles are arranged in an appropriate amount as compared with that of Example 1 (see FIGS. 1 and 2).

Example 2 Treatment of Organic Chlorine-Containing Waste Liquid Using Porous Ceramics Having an Amorphous Porous Surface According to the Present Invention The porous surface having an amorphous pore surface having a diameter of 6 to 10 mm obtained in Example 1. Using a 50:50 mixture of ceramics and activated carbon (manufactured by Takeda Pharmaceutical Co., Ltd.), 10 liters of a factory effluent containing tetrachloroethylene was treated as follows using the treatment apparatus shown in FIG.

As shown in FIG. 3, the diameter is 26 mm and the length is 1
The porous ceramics 12.5 in which the pore surface obtained in Example 1 had an amorphous surface was placed in a column 6 having a size of 03 mm and a volume of 50 ml.
g of the same amount of the activated carbon mixture 7 and a device in which three of them are connected in series, and the water line speed is 0.2 mm /
The long-term continuous operation was performed for 14 seconds (100 days) with a water flow time of 14,400 minutes (seconds, contact time: 25 minutes, 45 seconds, treatment water amount: 6.7 ml / min). FIG. 4 shows the results.

In FIG. 4, the symbol ● represents the concentration of tetrachlorethylene in the waste liquid discharged from the factory, and the concentration varies for each sample obtained. In addition, the symbol ■ indicates the tetrachloroethylene concentration after the treatment. As can be seen from FIG. 4, the concentration of tetrachloroethylene in the waste liquid after the treatment using the porous ceramics having an amorphous pore surface according to the present invention is reduced to 0.01 mg / L, which is a water quality standard in Japan. It was much lower than 0.1 mg / L.

The tetrachloroethylene concentration of 0.0
It was confirmed that the processing capacity of 1 mg / L continued until the continuous water flow time of 10680 minutes. According to these results, the action of the porous ceramics having an amorphous pore surface according to the present invention cannot be explained by mere physical adsorption, and no microbial growth is observed in the column. However, it is thought that tetrachloroethylene was decomposed by some action.

Comparative Example 2: Treatment of Organic Chlorine-Containing Waste Liquid Using Only Activated Carbon Same as Example 2 except that only activated carbon was used in place of the mixture of porous ceramic having an amorphous pore surface and activated carbon in Example 2. I went to. The result is shown in FIG.
In FIG. 5, the symbol ● represents the tetrachloroethylene concentration after the treatment with the mixture of the porous ceramics having the pore surface amorphous material and the activated carbon, and the symbol Δ represents the tetrachloroethylene concentration in the activated carbon alone treatment.

As can be seen from FIG. 5, when only activated carbon is used, the amount of tetrachlorethylene in the waste liquid is
It decreased only to 0.1 mg / L. This value is 10 times that in the case of using the mixture of the porous ceramics and the activated carbon in which the pore surface is amorphous in Example 2,
From this, the effectiveness of the porous ceramic having an amorphous pore surface according to the present invention can be clearly understood.

Comparative Example 3 Treatment of Organic Chlorine-Containing Waste Liquid Using Porous Ceramics by Conventional Method The same procedure as in Example 2 was carried out except that the porous ceramics produced in Comparative Example 1 was used. As a result, Comparative Example 1
The treatment with the mixture of the porous ceramic and the activated carbon produced by the method described above is not much different from the treatment with the activated carbon alone in Comparative Example 2 described above, and the porous ceramic having an amorphous pore surface of the present invention and the activated carbon have the same tetrachlorethylene adsorption capacity and sustainability. Was inferior to the case of using.

[0051]

The use of the porous ceramics having an amorphous pore surface according to the present invention makes it possible to remove and decompose harmful and polluting substances in wastewater and wastewater, which are currently a problem in treatment. Since the removal / decomposition action lasts for a long time, it can be said that it is extremely practical.

Further, according to the production method of the present invention, not only can the above-mentioned porous ceramics having an amorphous pore surface be produced, but also a material having a high compressive strength range useful for treating wastewater and waste liquid can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state of a pore surface of a conventional porous ceramic.

FIG. 2 is a schematic view showing a state of a pore surface of a surface amorphous porous ceramic of the present invention.

FIG. 3 is a longitudinal sectional view of an apparatus for treating an organic chlorine-containing waste liquid.

FIG. 4 is a view showing the result of long-term continuous treatment of a waste liquid containing tetrachloroethylene according to the present invention.

FIG. 5 is a view showing a comparison result between the treatment of the waste liquid containing tetrachloroethylene according to the present invention and the treatment with activated carbon alone.

[Explanation of symbols]

1 Surface of Porous Ceramic Particles 2 Continuous Pores of Porous Ceramic Particles 3 Crystalline Particles in Porous Ceramic Particles 4 Flow of Object to be Treated 5 Amorphous Portion of Porous Ceramic Particle Porous Surface 6 Waste Liquid Treatment Column 7 Porous Surface Amorphous Porous Mixture of ceramics and activated carbon

Claims (11)

[Claims] 1. A clay, a pore-forming material and water are mixed, molded into an appropriate shape, dried, and the dried molded body is heated to a temperature of 1: 1.
A method for producing porous ceramics by firing at 200 to 1500 ° C., wherein the molded body is maintained at a product temperature of 600 to 800 ° C. for 3 to 7 hours in the process of raising the temperature. A method for producing porous ceramics. 2. The production of a porous ceramic having an amorphous pore surface according to claim 1, wherein the temperature of the molded body is raised from room temperature to 600 to 800 ° C. over 5 to 15 hours. Method. 3. The pore surface according to claim 1, wherein the temperature of the molded article is raised from room temperature to 600 to 800 ° C. by the self-combustion of the pore-forming material in the molded article. A method for producing high quality porous ceramics. 4. The molded body is heated at 1200 to 1500 ° C. for 4 to 8 days.
4. The method for producing a porous ceramic having an amorphous pore surface according to claim 1, wherein the porous ceramic is fired for a period of time. 5. The molded body is heated at 1200 to 1500 ° C. for 4 to 8 days.
The method for producing a porous ceramic having an amorphous pore surface according to any one of claims 1 to 4, wherein the porous ceramic is subjected to a crusher treatment after firing for a time. 6. A porous ceramic having an amorphous pore surface. 7. The pore surface is amorphous and has a compressive strength of 6-8.
/ Kg / cm ² porous ceramics. 8. A porous ceramic having an amorphous pore surface produced by the method according to claim 1. Description: 9. A wastewater / wastewater treating agent comprising a mixture of activated carbon and porous ceramics whose pore surface is amorphous according to claim 6, 7 or 8. 10. A method for treating wastewater and wastewater, comprising using the porous ceramic having an amorphous pore surface according to claim 6, 7, or 8. 11. A method for treating wastewater and wastewater, comprising using a mixture of activated carbon and porous ceramics whose pore surfaces are amorphous according to claim 6, 7, or 8.