Background of the Invention The amount of wastewater or sewage has increased in large quantities due to development of industry, cityward drift of the population and large-scale progress of stockbreeding.

As prior arts for treatment of wastewater or sewage well known to those skilled in the arts, there have been heretofore proposed, for example, an activated sludge process, a fan turn oxidation process and so forth. In these processes, a precipitation tank for precipitating floating substances present in wastewater or sewage, an aeration tank for culturing and proliferating aerobic microorganisms, and so forth are required.

However, the conventional processes require the use of a precipitation tank, an aeration tank and the like, which force an installation to be large in size. The conventional processes also require another tank for decomposing organic compounds not entirely decomposed by aerobic microorganisms, since the ability of aerobic microorganisms to decompose organic compounds is inherently limited.

Further, another drawback of the conventional processes is that it takes a comparatively lengthy time to culture aerobic microorganisms and discompose organic compounds present in wastewater or sewage using the cultured microorganisms.

As described in the above, when it is considered that, in the processes, an installation needs to be large in size and a comparatively lengthy time is required to culture the aerobic microorganism, the processes cannot be said to be efficient in expense and time.

Meanwhile, another type of approaches, in which carriers are used for treating wastewater or sewage, has been developed.

In the Korean Laid-Open Patent No. 2002-0039292, disclosed is an invention in which either clayed minerals including allophane and imogolite converted from fly ash or burning-out ash or activated humus soil prepared by the addition of peat to the clayed minerals, is used for treating chlorophyat, red water, feces or urine. In the Korean Open- Laid Patent No. 2001-0105358, disclosed is an invention in which agropolymers are produced from plant material (Oryza sativa, Panicum miliaceum, Setaria italica, Cajanus cajan, rgna mungo, THigna radiata, Triticum sp., Ricinus communis, Helianthus annus, Gossypium sp., Arachis sp.) such as seed coats, husks or hulls of the various agriculture corps to be used for purifying wastewater or sewage including dissolved metals and ions. In addition, in the Korean Laid-Open Patent No. 1998- 0033476 disclosed is an invention in which yellow soil isolated in Korea is used for treating chlorophyat or red water, and in the Japanese Laid-Open Patent No. 2001- 179284 disclosed is an invention in which silica is used for treating livestock wastewater, faces or urine.

However, since the above-mentioned methods using carriers are to eliminate specific contaminants or pollutants, the methods require an additional installation or additional physical or chemical processes for eliminating the remaining contaminants or pollutants. There is also a limit to the ability of the methods to purify wastewater or sewage in case where the wastewater or sewage is severely contaminated.

The present invention has been made keeping in mind the above-described problems occurring in the prior arts, and therefore the present invention provides graphite powder having an excellent efficiency in treating wastewater or sewage or cleaning air, produced through a ball milling process.

Brief Description of the Accompanying Drawing FIG. 1 is a scanning electron microscope (hereinafter, "SEM") photograph of artificial graphite used in an embodiment of the present invention.

FIG. 2 is an X-ray diffraction curve of artificial graphite used in an embodiment of the present invention.

FIG. 3 is a SEM photograph of artificial graphite used in another embodiment of the present invention.

FIG. 4 is an X-ray diffraction curve of artificial graphite used in another

embodiment of the present invention.

FIG. 5 is a SEM photograph of crystalline flake graphite used in still another embodiment of the present invention.

FIG 6 is an X-ray diffraction curve of crystalline flake graphite used in still another embodiment of the present invention.

FIG. 7 is a SEM photograph of crystalline flake graphite used in still another embodiment of the present invention.

FIG. 8 is an X-ray diffraction curve of crystalline flake graphite used in still another embodiment of the present invention.

FIG. 9 is a SEM photograph of graphite powder obtained through a ball milling process according to an embodiment of the present invention.

FIG 10 is an X-ray diffraction curve of graphite powder obtained through a ball milling process according to an embodiment of the present invention.

FIG 11 is a SEM photograph of graphite powder obtained through a ball milling process according to another embodiment of the present invention.

FIG 12 is an X-ray diffraction curve of graphite powder obtained through a ball milling process according to another embodiment of the present invention.

FIG 13 is a SEM photograph of graphite powder obtained through a ball milling process according to still another embodiment of the present invention.

FIG 14 is an X-ray diffraction curve of graphite powder obtained through a ball milling process according to still another embodiment of the present invention.

FIG 15 is a SEM photograph of graphite powder obtained through a ball milling process according to still another embodiment of the present invention.

FIG 16 is an X-ray diffraction curve of graphite powder obtained through a ball milling process according to still another embodiment of the present invention.

FIG 17 is a SEM photograph of graphite powder obtained through a ball milling process according to still another embodiment of the present invention.

FIG 18 is an X-ray diffraction curve of graphite powder obtained through a ball milling process according to still another embodiment of the present invention.

FIG 19 is a SEM photograph of graphite powder obtained through a ball milling process according to still another embodiment of the present invention.

FIG 20 is an X-ray diffraction curve of graphite powder obtained through a ball milling process according to still another embodiment of the present invention.

FIG 21 is an X-ray diffraction curve of artificial graphite used an ultra-fine grinding process of a comparative example.

FIG 22 is an X-ray diffraction curve of crystalline flake graphite used an ultra- fine grinding process of another comparative example.

FIG 23 is an X-ray diffraction curve of graphite powder produced from artificial graphite through an ultra-fine grinding process of a comparative example.

FIG 24 is an X-ray diffraction curve of graphite powder obtained from crystalline flake graphite through an ultra-fine grinding process of another comparative example.

Detailed Description of the Invention Technical Theme An object of the present invention is to provide graphite powder that is obtained through a ball milling process and has an excellent efficiency in treating wastewater or sewage or cleaning air.

A further object of the present invention is to provide a composition for treating wastewater or sewage comprising the graphite powder.

A still further of the present invention is to provide a process for treating wastewater or sewage using the treating composition.

A still further object of the present invention is to provide a composition for cleaning air comprising the graphite powder.

A still further object of the present invention is to provide a process for cleaning air using the cleaning composition.

The additional object or aspect of the present invention is presented hereinafter.

Technical Solution In an aspect, the invention relates to graphite powder that is obtained through a ball milling process and has an excellent efficiency in treating wastewater or sewage or cleaning air.

More particularly, the graphite powder of the present invention is the graphite powder obtained by a process comprising the following steps of : (a) grinding graphite through a ball milling process; and (b) recovering graphite powder produced in step (a).

In this specification and the accompanying claims, the graphite of the above step (a) means all types of graphite that can be used in a ball milling process.

Therefore, it should be understood that the graphite includes both artificial graphite and natural graphite, irrespective of its type, that is, crystalline flake graphite and amorphous graphite, insofar as they can be used in a ball milling process.

In addition, the graphite of the above step (a) includes graphite powder obtained by a ball milling process. Therefore, it should be understood that the graphite powder of the present invention includes the graphite powder produced through a ball milling from the graphite powder already grinded through a ball milling process.

Meanwhile, the ball milling process, which is used for producing the graphite powder of present invention, means generally a process in which a mixture of two or more kinds of metal particles or metal and ceramic particles are put into a jar with several balls, and are subject to repetitive cycles of mixing, pressure-welding, deformation, fracturing and re-welding through ball milling, and thus suffer high mechanical energy. The balling process has been used in mechanical grinding for obtaining fine particles or mechanical alloying.

The mechanical energy provided by a ball milling process is dependent upon a ball milling apparatus type and operating parameters such as a ball milling velocity (means, as a working velocity of a ball milling apparatus, the revolutionary rotating velocity of jar, in which a ball milling process is performed), a ball milling time, a weight ratio of ball and raw material, and/or a ratio of ball size (hereinafter is presented by a radius) and jar volume.

In an embodiment of the present invention, graphite is grinded by a planetary ball mill apparatus under an air atmosphere and room temperature using the following operating parameters: Ball milling velocity: 300 rpm to 4000rmp Ball milling time: 3 min to 120 min Ball: raw material (weight ratio) = 1: 0.15 to 1: 0.5 Ball size/Jar volume (mm/m) = 0.02 to 0.06 Therefore, in the above step (a), it is preferred that the graphite is grinded under an air atmosphere.

In addition, it is preferred that the graphite is grinded under a room temperature.

In addition, it is preferred that the graphite is grinded by the above-mentioned ball milling apparatus under an air atmosphere and room temperature using the above- mentioned ball milling velocity, ball milling time, weight ratio of ball and raw material

and/or ratio of ball size and jar volume.

Meanwhile, the graphite powder of the present invention has the following properties: (1) Average particle size (fou) : 0.04 to 50, preferably 10 to 50, more preferably 12to46 (2) Micropore area (m2/g) : 100 to 300, preferably 120 to 270, more preferably 130 to 220 (3) External surface area (m2/g) : 240 to 450, preferably 250 to 420, more preferably 260 to 400 (4) Micropore volume (m3/g) : 0.063000 to 0.099000, preferably 0.064000 to 0.097000, more preferably 0.065000 to 0.095000 (5) Amorphousness More particularly, the graphite powder of the present invention has an average particle size of 12 to 46 am, a micropore area of 145 to 210 m2/g, external surface area of 261 to 390 m2/g, a micropore volume of 0.065100 to 0.094100 m3/g, and amorphousness, as shown in the following table 3.

In another aspect, the invention relates to a composition for treating wastewater or sewage comprising, as an effective agent, the above-described graphite powder.

In this specification and the accompanying claims, it should be understood that the graphite powder contained as an effective agent in the treating composition of the present invention has the meaning to include all types of graphite powders described to be preferable in the above.

Therefore, the graphite powder contained in the treating composition of the present invention has the meaning to include the graphite powder obtained through a ball milling process, preferably, to include the graphite powder obtained by being grinded under an air atmosphere as well as the graphite powder obtained by being grinded under a room temperature, more preferably, the graphite obtained by being grinded by the above-mentioned ball milling apparatus under an air atmosphere and room temperature using the above-mentioned ball milling velocity, ball milling time, weight ratio of ball and raw material and/or ratio of ball size and jar volume. Still more preferably, the graphite powder contained in the treating composition of the present invention has the above-described properties.

The treating composition of the present invention has a powerful purifying effect on wastewater or sewage because of the graphite powder contained as an effective

agent in the treating composition (refer to the following tables 4 and 5).

Generally, unprocessed graphite particles coming into market have no purifying effect (refer to the following table 7).

In addition, graphite powder produced through an ultra-fine grinding process has a purifying effect but doesn't go beyond a low level (refer to the following table 8).

However, the purifying effect of the graphite powder produced through a ball milling process is powerful to the extent that it cannot be compared to that of the graphite powder produced through an ultra-fine grinding process as well as that of the unprocessed graphite particles (comparatively refer to the following tables 4,5, 7 and 8).

The reason that there is such a significant difference in the purifying effect among the unprocessed graphite particles and the two processed graphite powders is supposed to be that they have different properties one another (comparatively refer to the following tables 1 and 3, and the accompanying figures 1 to 24).

Meanwhile, in embodiments of the present invention, a ball milling process has been performed for graphite under various operating conditions in order to observe that a difference among the conditions leads to a difference among the purifying effects of graphite powders obtained. However, the difference among the conditions doesn't lead to a significant difference among the purifying effects of the produced graphite powders (refer to the following tables 4 and 5).

These results can be said to show that the difference among the conditions doesn't cause a significant difference among the purifying effects of the graphite powders produced through a ball milling process.

Accordingly, the graphite powder contained as an effective agent in the treating composition of the present invention includes all types of graphite powders produced through a ball milling process regardless of the operating conditions under which a ball milling process is performed.

Nevertheless, the graphite powder preferably is the graphite powder described to be preferable in the above.

Meanwhile, the treating composition of the present invention can include only the graphite powder produced through a ball milling process, which doesn't undergo any further physical and chemical processes, and, in fact, it is preferred that the composition includes only such graphite powder. However, the treating composition can include additives such as calcium carbonate (CaCO3) and so forth in addition to the graphite powder. Preferably, such additives can be added in an amount from 10 to 20 weight percent based on the total weight of the treating composition.

In another aspect, the present invention relates to a method for treating wastewater or sewage using the treating composition described in the above.

The treating method of the present invention comprises the following steps of : (i) contacting wastewater or sewage with the above-described treating composition ; and . (ii) recovering purified water.

When the graphite powder present in the above-described treating composition comes into contact with contaminants present in wastewater or sewage to absorb those contaminants, the purified water can be recovered by removing the contaminant- absorbed graphite powder.

Methods using chromatography and so forth, well known in the related arts, can be used for removing the contaminant-absorbed graphite powder. In embodiments of the present invention, a glass tube to be manufactured according to a special order was used for recovering the resultant purified water. The glass tube is equipped with a stopcock and has a volume of 3 L and a size of about 18 O.

Meanwhile, in embodiments of the present invention, the graphite powder is poured into a container including crude wastewater and is agitated to allow the graphite powder to be easily contacted with the contaminants present in the crude wastewater so that the purifying time can be shorter. Accordingly, the treating method of the present invention does not necessarily require the step of agitating the mixture of graphite powder and wastewater or sewage. In the treating method of the present invention, the agitation step may also be replaced with another step insofar as the step allows the graphite powder to be easily contacted with contaminants present in wastewater or sewage.

Further, the treating method of the present invention preferably includes the step of contacting wastewater or sewage with a polymer-aggregating agent prior to step (i) in case where the polymeric organic contaminants are contained in large quantities in wastewater or sewage. The polymer-aggregating agent comprises iron chloride or aluminum sulfate as additives, Fecal3, A12 (S04) 3, anions or cations as aggregating agents, Ca (OH) 2 or NaOH as counteragents, polymeric compounds as supplement agents and H2SO4 as pH mediators. However, the step of contacting wastewater or sewage with a polymer-aggregating agent is required according to the type and/or nature of wastewater or sewage. Accordingly, although polymeric organic contaminants are contained in large quantities in wastewater or sewage, step (i) of contacting wastewater or sewage with the

graphite powder can be directly performed without passing through the step of contacting wastewater or sewage with a polymer-aggregating agent. Like this, the step of contacting wastewater or sewage with a polymer-aggregating agent is not necessarily required in the treating method of the present invention.

Further, in the case of passing through the step of contacting wastewater or sewage with a polymer-aggregating agent, it is preferred that the treating composition is mixed with the resultant recovered after the step in an amount from 20 to 25 weight percent based on the total weight percentage of the resultant, in order to obtain a more high purifying effect.

In further another aspect, the present invention relates to a composition for cleaning air comprising as an effective agent the graphite powder described in the above.

In this specification and the accompanying claims, it should be understood that the graphite powder contained as an effective agent in the cleaning composition of the present invention has the meaning to include all types of graphite powders described to be preferable in the above, like the graphite powder contained as an effective agent in the above-mentioned treating composition.

In an embodiment of the present invention, when the purifying effect was observed after the graphite powder had been mixed with crude wastewater obtained from a dye factory, in which ammonia was dissolved in large quantities, and it had been agitated, the graphite powder was shown to eliminate the ammonia about half as well as to lower remarkably the pH, chemical oxygen demand (COD) level, biological oxygen demand (BOD) level and suspended solids (SS) level of the crude wastewater (refer to the following table 2).

In another embodiment of the present invention, when a deodorization experiment has been performed for both ammonia gas and formaldehyde gas, the deodorization percent is shown to be 98.6% or more and 97.6% or more respectively (refer to the following table 6).

These results can be said to mean that the graphite powder of the present invention can be used very usefully as an effective agent of an air-cleaning composition.

Meanwhile, the cleaning composition of the present invention can include calcium carbonate (CaC03) and so forth as additives like the above-described treating composition of the present invention. For the same reason, it is preferred that such additives may be added in an amount from 10 to 20 weight percent based on the total weight percentage of the cleaning composition.

In further another aspect, the present invention relates to a method for cleaning air using the cleaning composition described in the above.

The cleaning method of the present invention comprises the step of contacting air with the above-described cleaning composition.

In further another aspect, the present invention relates a method for re-using graphite powder as an effective agent of a treating composition of wastewater or sewage or a cleaning composition of air, comprising the step of segregating the graphite powder from complexes of the graphite powder and contaminants or pollutants.

In this case, the graphite powder means preferably all the preferable graphite powders described in the above, more preferably, the graphite powder that is contained as an effective agent in the above-mentioned treating composition and cleaning composition of the present invention.

In case where the graphite powder absorbs the contaminants or pollutants present in wastewater, sewage or air to become part of the complexes of the graphite powder and the contaminants, the graphite can be easily segregated from the complexes using an oven operating at about 1000°C high temperature or vapor of about 1000°C high temperature without influencing the properties of the graphite powder, since the melting point of graphite is high temperature of about 3500°C.

Peculiar Effect As described in detail in the above, according to the present invention, the graphite powder having an excellent efficiency in treating wastewater or sewage or cleaning air, obtained through a ball milling process, can be provided In addition, the treating composition and method for wastewater or sewage and a cleaning composition and method for air can be provided.

The graphite powder of the present invention has an excellent efficiency in treating wastewater or sewage or cleaning air.

Best Mode for Carrying Out the Invention Hereinafter, the present invention will be described in detail with reference to the following examples and comparative examples, which should not be construed to be

limiting to the scope of the present invention.

Examples 1 to 6. Production of graphite powders through a ball milling process The graphites to be used for a ball milling process of examples 1 to 6 are shown in the following Table 1. The same artificial graphite was used in examples 1,3 and 5.

Table 1. Grinding Conditions Items Example 1 Example 2 Example 3. Example 4 Example 5 Example 6 Artificial Artificial Artificial Crystalline Artificial Crystalline flake Graphite type graphite graphite graphite flake graphite graphite graphite Average particle 123.639 416.644 123.639 20.721 123.639 34.215 size BET area (m2/g) 0.9635 1.2902 0.9635 7.8029 0.9635 2.3261 Micropore area 1.7695 0.9051 1.7695 0.3275 1.7695 2.8086 (MI/g) External surface - 0. 8060 0.3852-0. 8060 7.4754-0. 8060-0.4825 area (m2/g) Micropore 0.000829 0.000413 0.000829 0.000107 0. 000829 0.001339 volume (m/g) SEM photograph Fig. 1 Fig. 3 Fig. 1 Fig. 5 Fig. 1 Fig. 7 X-ray diffraction Fig. 2 Fig. 4 Fig. 2 Fig. 6 Fig. 2 Fig. 8 curve

* BET area (Brunaer Emmett Teller Area) = Micropore area + External surface area The BET area, micropore area, external surface area and micropore volume was determined with the Specific Surface Area Analyzer (ASAP-2010, Micromeritics Inc.).

The average particle size was determined using the laser analysis method (Particle Size Analyzer (Mastersizer 2000, Malvern Instrument Ltd.)).

Each of the graphites of the table 1 was grinded with the grinding conditions of the following table 2 under an air atmosphere and room temperature.

Table 2. Grinding Conditions Items Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Ball Milling Velocity (rpm) 300 600 1200 2500 3000 4000 Ball Milling Time (hr) 120 60 30 10 5 3 Ball Size (mm) 5 6 8 10 12 15 Ball Material SS TCC Si3N4 ZrO2 SiC Al203 Ball Mass Inputted 100#200 200#300 300#400 500#600 300#400 200#300 (g) Jar Volume (ml) 250 250 250 250 250 250 Jar Material SS TCC STC Al203 TCC SS Graphite Particles Mass Inputted 30 50 70 100 120 100 (g) Type of Mechanical Planetary Planetary Planetary Planetary Planetary Planetary Alloying Apparatus Ball Mill Ball Mill Ball Mill Ball Mill Ball Mill Ball Mill

In the above Table 2, "SS"is an abbreviation of stainless steel, "TTC"is an abbreviation of tungsten carbide coating, and"STC"is an abbreviation of steel tool carbon.

Properties of each of the graphite powders obtained by being grinded under the grinding conditions of the above table 2 were presented in the following table 3.

Table 3. Properties of each of graphite powders obtained Items Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Average 16.272 15.646 18.053 12.104 45.104 14.583 particle size BET area 577.8823 491.5575 555.9961 446.3976 569.7565 408.1115 (m2/g) Micropore 190.8216 145.5474 208.0350 164.6615 189.0935 146.4511 area (m2/g) External surface area 387.0607 346.0101 347.9611 281.7361 380.6631 261.6604 (m2/g) Micropore 0.085771 0.065102 0.094033 0.074466 0.085028 0.066376 volume (m2/g) SEM Fig. 9 Fig. 11 Fig. 13 Fig. 15 Fig. 17 Fig. 19 photograph X-ray diffraction Fig. 10 Fig. 12 Fig. 14 Fig. 16 Fig. 18 Fig. 20 curve

* BET area (Brunaer Emmett Teller Area) = Micropore area + External-surface area As in the above table 1, the BET area, micropore area, external surface area and micropore volume were determined with the Specific Surface Area Analyzer (ASAP- 2010, Micromeritics Inc. ). In addition, the average particle size was determined using the same laser analysis method as in the above table 1.

As the above table 1 is compared with table 3 or Figs. 1 to 8 are compared with Figs. 9 to 20, it could be supposed that the graphite were grinded to produce the graphite powders undergoing the alteration of properties through a ball milling process.

Hereinafter, for convenience, graphite powders recovered through grinding under the grinding conditions of Examples 1 to 6 shown in the above Table 2 are referred to as graphite powder 1, graphite powder 2, graphite powder 3, graphite powder 4, graphite powder 5 and graphite powder 6, respectively.

Example 7. Purifying effect of graphite powders for wastewater or sewage The graphite powders 1 to 6 were used for treatment of wastewater or sewage in order to identify a use of the graphite powders 1 to 6.

The graphite powders 1 to 6 were used for treatment of wastewater or sewage without undergoing additional physical and chemical processes, as described in Example 7.

Crude wastewater and pretreated wastewater were treated with the graphite powder 1 to 6 to measure those purifying effect. Purification experiments for the crude wastewater and pretreated wastewater are described in the following example 7-1 and

7-2 respectively.

Example 7-1. Treatment of crude wastewater with graphite powder Crude wastewater used in this test was obtained from a dye factory located in Ansan-shi, Kyunggi-do, Republic of Korea. As a result of measuring the contamination level of the crude wastewater, the acidity (pH), chemical oxygen demand (COD), biological oxygen demand (BOD), suspended substance (SS) and concentration of total dissolved ammonia (T-N) of the crude wastewater were turned out to be 12.9, 3184 ppm, 884 ppm, 410 ppm and 20.5 ppm, respectively.

1.0 L of the crude wastewater was poured into a container of 1.5 L together with 10 g of the graphite powder, and was agitated for sufficient mixing. And then whether or not a purifying reaction occur was observed, and, if the purifying reaction didn't occur, the graphite powder was further added in an amount of 5 g at a time and then agitated. In this way, the quantity of the graphite powder to be inputted was determined. The purifying reaction began to occur after the graphite powder of 250 g or more had been inputted. The further graphite powder was consecutively inputted in an amount of 5 g at a time and then agitated until the quantity of the inputted graphite powder was finally up to 300 g. A glass tube manufactured according to special order was used for recovering the resulting purified water. The glass tube was equipped with a stopcock and had a volume of 3 L and a size of 18 (D.

The above-described purifying process was performed in the same way for graphite powders 1 to 6.

The pH, COD, BOD, SS and T-N of the recovered purified waters are shown in the following Table 2 along with those of the crude wastewater.

Table 4. Comparison of pH, COD, BOD, SS and T-N of the purified water with those of the crude wastewater. Items pH COD (ppm) BOD (ppm) SS (ppm) T-N (ppm) Crude Wastewater 12.90 3184 884 410 20.5 Graphite Powder 1 11.00 620 210 8 9.5 Graphite Power 2 11.00 616 236 12 10.0 Graphite Power 3 11.00 664 255 12 10.5 Graphite Power 4 10.00 660 255 12 10. 5 Graphite Power 5 11.00 872 335 100 15.0 Graphite Power 6 11.42 800 307 50 14.5

The above table 4 shows that the graphite powders 1 to 6 have a powerful purifying effect on crude wastewater.

Example 7-2. Treatment of pretreated wastewater with graphite powder The same crude wastewater as used in the Example 7-1 was pretreated with a polymer-aggregating agent so that organic contaminants were eliminated from the crude wastewater. The pretreated wastewater was used for the following purifying process in order to examine the purifying effect of the graphite powder.

A polymer-aggregating agent (500 mg of H202, about 200 mg of cation, about 2-3 mg of anion, 1500 mg of H2S04) was added into the crude wastewater samples of 1.0 L together with ferric chloride as an additive to precipitate polymeric organic contaminants existing in a colloidal state in the crude wastewater. And then the precipitated polymeric organic contaminants were aggregated in the form of flocks to be eliminated. In this way, the pretreated wastewater was recovered. As a result of measuring the contamination level of the isolated crude wastewater, the pH, COD, BOD and SS of the pretreated wastewater were shown to be 8. 81, 1840 ppm, 310 ppm and 66 ppm respectively.

The pretreated wastewater of 1.2 L was poured into a container of 1.5 L together with graphite powder 1 and was agitated for sufficient mixing. Then, whether or not a purifying reaction occurs was observed, and, if the purifying reaction didn't occur, the graphite powder was further added in an amount of 5 g at a time and then agitated. In this way, the quantity of the graphite powder to be inputted was determined. The purifying reaction began to occur after the graphite powder amount of 250 g or more had been inputted in total. The further graphite powder was consecutively inputted in an amount of 5 g at a time to be agitated until the quantity of the inputted graphite powder was finally to be 300 g.

A glass tube, which was manufactured according to special order, was used for recovering the resulting purified water. The glass tube equipped with a stopcock had a volume of 3 L and a size of 18 0.

The above-described purifying process was performed representatively only

for graphite powders 1.

The pH, COD, BOD, SS and T-N of the recovered purified water are shown in the following Table 3 together with those of the pretreated wastewater.

Table 5. Comparison of pH, COD, BOD, SS and T-N of the purified water and the pretreated wastewater. Items PH COD (ppm) BOD (ppm) SS (ppm) Pretreated wastewater 8.81 1840 310 66 Purified water 8.00 440 105 9 Table 5 shows that the graphite powder has a powerful purifying effect on pretreated wastewater.

Example 8. Purifying effect of graphite powders for air Two flasks were prepared. 7g of Graphite powder, wrapped with non-woven fabric, was put into one flask while graphite powder was not put into the other flask.

4 mE of ammonia solution was poured into each of two flasks and was gasified. Deodorization percent was calculated using a gas detection method by determining a density of gas contained in each of two flasks after each of predetermined times was passed.

Deodorization percent was calculated according to the following formula: Deodorization percent (%) = ( (Cb-Cs)/Cb) X 100 * Cs: Gas density in the flask containing graphite powder * Cb: Gas density in the flask not containing graphite powder Deodorization percent for formaldehyde was determined in the same way as in the above.

Meanwhile, this example was performed representatively only for graphite powders 1.

Deodorization percent for formaldehyde gas and ammonia gas was presented in the following table 6.

Table 6. Deodorization percent for formaldehyde gas and ammonia gas Items 5min 15mm 30mm 60mm Ammonia 98. 6% or more 98. 6% or more 98. 6% or more 98. 6% or more Formaldehyde 97.6% or more 97.6% or more 97.6% or more 97.6% or more

As shown table 6, the graphite powder has a powerful cleaning effect on air.

Comparative Example 1. Comparison of purifying effect of unprocessed graphite particle with that of graphite powder.

The purifying effect of graphite powder according to the present invention was observed in comparison with that of artificial graphite particles prior to being subjected to a ball milling process. In this process, the same artificial graphite particles as used in Examples 1 to 6, the graphite powders 1 to 6, and the pretreated wastewater recovered through pretreatment in Example 7-2 were used.

10 g of the unprocessed artificial graphite particles and 10 g of the graphite powder were mixed with 10 m of the pretreated wastewater respectively. Then, whether or not a purifying reaction was occurred was observed with a naked eye by observing the degree of clearness of the pretreated wastewater. This process was performed in the same way for the graphite powders 1 to 6.

The results are shown in the following Table 7.

Table 4. Comparison of purifying effect of graphite particle and powder Un processed Artificial Item Graphite Powders 1 to 6 graphite particles Quantity of pretreated 10 mQ 10 mQ wastewater Quantity of Graphite inputted 10 g 10 g Jar Size H (6cm)/ (3) -reagent bottle H (6cm)/0 (3) -reagent bottle After 10 sec, the purification effect Little or No purification Results was observed with naked eye and effect proceeded up to 2 min.

Table 7 shows that only the graphite powders 1 to 6 have a purifying effect on the pretreated wastewater.

Comparative Example 2. Comparison of purifying effect of graphite powder of the present invention obtained through a ball milling process with that of graphite

powder obtained through an ultra-fine grinding process Two types of graphite powders were produced respectively through an ultra- fine grinding process under two different grinding conditions, in order to compare the purifying effects of the graphite powders produced through an ultra-fine grinding process with those of graphite powders 1 to 6 produced through a ball milling process.

One type of graphite powder of which average particle size is about 5, zn was produced through an ultra-fine grinding apparatus (Jet Mill, available from Seishin Co.

Japan) from the artificial graphite particles which consist of carbon of 99.4 % and ash of 0.6 % and have an average particle size of 45, nan. Hereinafter, for convenience, the produced graphite powder is referred to as the"ultra-fine graphite powder 1".

The other type of graphite powder of which average particle size is about 5 tan was produced through a ultra-fine grinding apparatus (Jet Mill, available from Seishin co. Japan) from the crystalline flake graphite particles which consist of carbon of 99.6 % and ash of 0.4 % and have an average particle size of 26, um. Hereinafter, for convenience, the produced graphite powder is referred to as the"ultra-fine graphite powder 2".

Figs. 21 and 22 are respectively the X-ray diffraction curves of the artificial graphite particles (starting material of the ultra-fine graphite powder 1) and crystalline flake graphite particles (starting material of the ultra-fine graphite powder 2) prior to being subjected to the ultra-fine grinding process. Figs. 23 and 24 are respectively the X-ray diffraction curves of the ultra-fine graphite powder 1 and ultra-fine graphite powder 2.

Comparing Figs. 9 to 20 with Figs. 23 and 24, it can be supposed that the graphite powder obtained by a ball milling process has remarkably different properties from the graphite particles obtained by an ultra-fine grinding process.

In the meanwhile, the purifying processes were performed using the ultra-fine graphite powder 1 and ultra-fine graphite powder 2 in the same way as described in Example 7-1, in order to compare the purifying effects of the graphite powders produced through an ultra-fine grinding process with those of the graphite powders 1 to 6 produced through a ball milling process.

The pH, COD, BOD, SS and T-N of the purified water recovered according to the above processes are shown in the following Table 8 together with those of the crude wastewater.

Table 8. Comparison of pH, COD, BOD, SS and T-N of crude wastewater with those of purified water. Division pH COD (ppm) BOD (ppm) SS (ppm) T-N (ppm) Crude Wastewater 12.90 3184 884 410 20.5 Ultra-fine Graphite Powder 12. 50 2500 884 300 20. 5 1 Ultra-fine Graphite Power 2 12. 00 2800 960 380 20. 5

As shown in the above Table 8, the graphite powders produced through an ultra-fine grinding process have a purifying effect on wastewater like the graphite powders produced through a ball milling process.

However, the purifying effect of the graphite powders produced through an ultra-fine grinding process is far lower than that of the graphite powders produced through a ball milling process as it is clearly established by a comparison of results in table 8 with those in table 4.