KR100220021B1 - Photocatalyst for treating waste water and process of treating waste water using the said catalyst - Google Patents

Abstract

The present invention provides a process for producing a catalyst for treating wastewater, characterized in that at least one of oxides, carbonates and hydroxides is added to and mixed with titanium dioxide or metatitanic acid, followed by ball milling and then calcining at 550 to 1100 ° C . Also, at least one of oxides, carbonates, and hydroxides is mixed with 0.01 wt% to 5.0 wt% to provide a catalyst for treating wastewater according to the above production method.

The present invention also provides a method for treating wastewater, characterized in that the catalyst produced by the above method is contacted with wastewater while irradiating light having a wavelength of 200-600 nm.

Description

Process for producing wastewater treatment catalyst, catalyst for treating wastewater and method for treating wastewater using the same

The present invention relates to a catalyst for treating wastewater, and more particularly, to a catalyst for treating wastewater with improved efficiency of wastewater treatment, a method for producing the catalyst, and a method for treating wastewater using the same.

Conventional wastewater treatment methods include biological methods and chemical methods called activated sludge methods. The activated sludge process takes a long time to decompose organic compounds and the wastewater should be diluted to a concentration suitable for the growth of algae and bacteria. Therefore, this method has a disadvantage that wastewater containing aromatics organic matter, which is a decomposing substance, is required to have a large space for disposing a treatment facility, and the activated sludge is shocked or not treated well and discharged without being decomposed.

Currently, the most commonly used chemical treatment methods are iron oxidation, Fenton oxidation, and ozone oxidation. The iron oxidation method uses ferric oxide and ferric oxide by simple oxidization and coagulation. It is inexpensive, easy to treat, and has good flocculation but low treatment efficiency. The Fenton oxidation method is a method using ferrous or ferric oxide and hydrogen peroxide having a high oxidizing power under an acidic condition. Although the treatment efficiency is relatively high, it is almost impossible to treat wastewater containing refractory organic matter. Recently, the ozone oxidation method, which is widely used for drinking water treatment, has a high treatment cost and secondary pollution to ozone. It is necessary to adsorb the gas generated after ozone treatment with activated carbon, the apparatus of ozone generator is complicated and the treatment of drinking water is easy, It is not suitable for the treatment efficiency of wastewater containing organic substances. In addition, high-temperature high-pressure method and oxidation method using ultraviolet ray, ozone and hydrogen peroxide are known, but they are not suitable for water-repellent method because they are used only in waste water having a COD concentration of 100 ppm or less.

In general, the chemicals contained in wastewater to be treated are very diverse.

Organic matter contained in wastewater refers to a substance composed of elements such as carbon, hydrogen, nitrogen, oxygen, and sulfur. These substances are largely divided into alkane, alkene, and alkene. Depending on the type of functional group, it is divided into aldehyde, nitrile, alcohol, amine, amide, aromatic, and acid.

These organic materials are beneficial, but the wastewater from the manufacturing process flows into rivers and oceans and is a major factor impeding our natural environment.

As mentioned above, the kinds of organic matter contained in the wastewater are very diverse, and the treatment is very difficult.

Wastewater containing nitrogen-containing compounds such as amine compounds, amide compounds, and amino acid compounds in the wastewater is subjected to coagulation treatment using an anionic polymer coagulant, but subsequent treatment is required because it contains an amine in the sludge. The efficiency of the adsorbent deteriorates and it is difficult to effectively treat the adsorbent.

In the case of wastewater containing sulfur compounds, one or both of the biological treatment and the combustion method may be treated in parallel, but in the biological treatment, it is necessary to dilute the wastewater solution so that the organism is not adversely affected. Desulfurization equipment is needed because a large amount of sulfur dioxide is formed because the wastewater contains a lot of sulfur.

In the case of wastewater containing organohalogen compounds, organohalogen compounds are difficult to decompose and accumulate in the natural environment, resulting in groundwater contamination in many places. Moreover, these organohalogen compounds have been identified as carcinogenic substances and trichlorethylene, tetrachlorethylene, 1,1,1, - trichloroethane, etc. have been designated as regulated items in the Water Pollution Prevention Act. Known methods for treating wastewater containing organohalogen compounds include evaporation and adsorption methods, but it is difficult to prevent environmental pollution and it is necessary to process the adsorbent. The microbial decomposition method takes a long time to process, and the treatment efficiency is very unstable because it differs depending on the sludge. Photodegradation methods and radiant - radiation - radiation methods, which have been recently studied, are at the experimental stage.

As a general method for decomposing decomposable organic compounds by using a photocatalyst, ultraviolet rays are used as light, and titanium oxide, zinc oxide, iron oxide, cadmium sulfide, and zinc sulfide are used as catalysts.

A decomposition method using a photocatalyst is disclosed in U.S. Patent Nos. 5,266,540, 3,924,134, 4,370,263, and Korean Patent 96-1961.

However, these prior art techniques are mostly technical in terms of devices that are inefficient or highly commercialized. U.S. Patent No. 5,266,540 uses sludge composed of a catalyst selected from ultraviolet rays, charcoal, titanium oxide, zinc oxide, and iron oxide. The amount of catalyst used is 1.2%, which is not economical because the amount of catalyst used is high and the treatment efficiency is very low.

U.S. Patent No. 3,924,134 is a patent for a device and U.S. Patent No. 4,370,263 relates to a photocatalytic catalyst containing titanium dioxide treated with Niobium containing ruthenium oxide on its surface, And thus it is uneconomical.

In Korean Patent No. 96-1961, efficiency is very low when treating wastewater only with catalyst without using light, and the temperature of the wastewater treatment is in the range of 100-370 ° C, oxygen gas must be supplied and a constant pressure must be applied It is impossible to treat the flowing wastewater, and even if the wastewater is treated, there is a disadvantage that it is dangerous and the treatment cost is very high because it must be treated under high temperature and high pressure.

When a photon with an energy of hv comes in contact with a compound used as a photocatalyst, it has energy equal to or greater than the bandgap energy of the photocatalyst. As a result, the electron comes out of the valence band, ) And leave a hole in the place. The electrons in the excited state are returned to the electric field again, and the energy is released by the heat. At this time, when there is a proper scavenger or surface defect state, trapping electrons or holes causes a redox reaction without recombination. The valence band hole is a strong oxidizing agent, and the conduction band electrons become a good reducing agent. Most organic photolysis reactions utilize the oxidizing power of holes directly or indirectly. Titanium oxide, zinc oxide, iron oxide, cadmium sulfide, zinc sulfide, nickel oxide, and cobalt oxide can be used as the photocatalyst, but titanium oxide is known as the most suitable compound for practical application. The titanium oxide has an energy gap of 3.2 eV and is chemically and biologically stable, so that it does not easily corrode and is very cheap.

Titanium dioxide exists in two forms, anatase and rutile. Titanium dioxide in anatase form is converted to rutile when it is treated at a temperature higher than 1100 ° C. Since titanium dioxide itself has different properties depending on the conditions of production, that is, temperature and time, when the titanium dioxide itself is used as a catalyst, the reactivity is reduced and the amount of catalyst used should be increased. When titanium dioxide itself is used, the reactivity is decreased, so the amount of catalyst used should be increased and the reaction time is long, making commercialization difficult.

Disclosure of the Invention The present invention has been devised in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method for effectively decomposing organic compounds including aromatics, which are pyrolysis materials, as well as wastewaters containing nitrogen, sulfur and organic halogen compounds, And to provide a method for producing the titanium dioxide catalyst and a method for treating wastewater using the same.

FIG. 1 is a view showing a UV-visible light absorption spectrum of a compound prepared by incorporating Fe into titanium dioxide; FIG.

FIG. 2 is a view showing the UV-visible light absorption spectrum of a compound prepared by incorporating Mn into titanium dioxide; FIG.

FIG. 3 shows a UV-visible light absorption spectrum of crude wastewater containing pyridine (1000 ppm); FIG.

4 shows the UV-visible light absorption spectrum of wastewater treated with 60 wt% of titanium dioxide mixed with 0.4 wt% of iron oxide in a raw wastewater containing pyridine (1000 ppm) and irradiated with UV lamp (20 watt) for 60 hours ;

FIG. 5 is a graph showing the gas chromatogram of raw wastewater containing nitrobenzene (100 ppm); FIG.

FIG. 6 shows an example in which 0.4% by weight of cobalt oxide was added to the raw wastewater containing nitrobenzene (100 ppm)

This figure shows the gas chromatogram of the wastewater treated with the mixed titanium dioxide as a catalyst and irradiated with UV lamp (20 watt) for 120 hours

7 shows the liquid chromatogram of raw wastewater containing SKYBIO (1000 ppm);

FIG. 8 is a view showing a liquid chromatogram obtained by irradiating a raw wastewater containing SKYBI0 (1000 ppm) with titanium dioxide mixed with 0.4 weight% of chromium oxide as a catalyst and irradiating with a UV lamp (20 watt) for 2 hours to be.

The present invention relates to a catalyst for treating wastewater, and more particularly, to a method for producing a catalyst for treating wastewater with improved efficiency. The present invention provides a manufacturing method for wastewater treatment characterized in that at least one of oxides, carbonates, and hydroxides is added to and mixed with titanium dioxide or metatitanic acid, followed by ball milling and then calcining at 550 to 1100 ° C.

The present invention also provides a photocatalyst for wastewater treatment according to the above process, which comprises 0.01 to 5.0 wt% of at least one oxide, carbonic acid, and hydroxide.

The oxide may be at least one selected from the group consisting of iron oxide, chromium oxide (III), tin oxide (II), tin oxide (IV), copper oxide, zinc oxide, cobalt oxide, manganese oxide (II), manganese oxide ). The carbonate may be manganese carbonate, copper carbonate, zinc carbonate and iron carbonate. The hydroxide may be selected from the group consisting of aion oxyhydroxide (? -FeO (OH) 2), copper hydroxide, zinc hydroxide and iron hydroxide.

In the present invention, the ratio of at least one of oxides, carbonates, and hydroxides in the catalyst is in the range of 0.01 to 5.8 wt%, and more preferably 0.1 to 2.0 wt%. If the ratio of at least one of oxides, carbonates, and hydroxides is 0.01% or less, the effect is only a pure titanium dioxide catalyst. If the ratio is 5.0% or more, there is a problem that the titanium oxide is not incorporated. The firing temperature in the catalyst production method according to the present invention is preferably 550 to 700 占 폚. A catalyst exhibiting the best catalytic activity at the calcination temperature can be prepared. On the other hand, the catalyst developed in the present invention can be used in wastewater, and the size of the catalyst is larger than that of the conventional catalyst for reuse by filtration.

In the case of catalysts containing at least one of the oxides, carbonates, and hydroxides of the present invention, energy absorption takes place in a broad wavelength region and energy absorption occurs particularly in a visible light region. This fact can be clearly seen from the first and second roads. FIG. 1 is a diagram showing a UV-visible light absorption spectrum of a compound prepared by incorporating 0.1, 0.2, 0.4, and 0.6% of Fe into titanium dioxide, and FIG. 2 is a graph showing the absorption spectra of Mn, , 0.4% and 0.6%, respectively. As a result, organic materials can be decomposed using light having a wavelength in the visible light region. As described above, in the case of the titanium dioxide catalyst containing at least one of oxides, carbonates, and hydroxides of the present invention, it is effective in a wide range covering the UV and visible ray regions of 240 nm to 600 nm. On the other hand, pure titanium dioxide in which at least one of oxides, carbonates, and hydroxides are not mixed is ineffective in a narrow range of the UV ray region at 330 nm to 380 nm.

Catalysts prepared by mixing at least one of oxides, carbonates, and hydroxides from metatitanic acid are more economical and more efficient than those mixed with at least one of oxides, carbonates, and hydroxides in titanium dioxide. However, a catalyst prepared by mixing at least one of oxides, carbonates, and hydroxides with titanium dioxide shows a good treatment effect in wastewater treatment.

The catalyst for treating wastewater of the present invention is suitable for treating wastewater containing an aromatic compound, a nitrogen compound, a sulfide or an organic halogen compound.

The firing temperature and time in the preparation of titanium dioxide are very important factors in the properties of titanium dioxide. In the conventional titanium dioxide manufacturing process, metatitanic acid is produced as an intermediate. Potassium carbonate and a lithium compound are added as a calcining agent thereto, and titanium dioxide is produced by baking at 1100 ° C. for 4 hours. Since the titanium dioxide thus produced contains impurities even after being purified, the efficiency as a photocatalyst itself is somewhat deteriorated. Accordingly, in the present invention, at least one of oxides, carbonates, and hydroxides to be incorporated in the metatitanic acid is directly mixed with the titanium oxide catalyst, and then the titanium oxide catalyst is treated with a ball mill for 24-48 hours and then fired at 550-1100 ° C for 2-12 hours, . Alternatively, one or more of oxides, carbonates, and hydroxides may be added to the titanium dioxide that has been previously prepared, treated with a ball mill for 24-48 hours, and then fired at 550-1100 ° C for 2-14 hours to prepare a titanium dioxide catalyst have.

(A) adding wastewater to the wastewater by adding the catalyst for treating wastewater according to the present invention, and (b) contacting the wastewater with the catalyst while irradiating the mixture with light having a wavelength of 200-600 nm, The waste water treatment method comprising the steps of: Contact between the wastewater and the catalyst is preferably carried out at room temperature.

The catalysts prepared above were used to evaluate the COD removal rate and decomposition degree of the actual wastewater and the specific organic matter, the influence of the activated sludge after the treatment, and the odor removal efficiency in the case of the wastewater containing odor.

Although the catalyst preparation and wastewater treatment examples according to the embodiments of the present invention are described below, the present invention is not limited to the following description.

[Example]

[Example 1]

The weight of titanium dioxide and iron oxide were weighed so that the weight of iron oxide was 100 g and the weight of iron oxide was 0.01, 0.03, 0.05, 0.2, 0.4, 0.6, 0.8, 1.0, 2.0 and 5.0% Add a small amount and mix well.

Put on a speed adjustable ball mill, ball mill for 24-48 hours, dry at 100-110 ℃, crush with mortar and keep fine. And then sintered in an electric furnace at 700 ° C for 2-8 hours to prepare a titanium dioxide catalyst containing iron oxide.

[Example 2]

A titanium dioxide catalyst having manganese carbonate incorporated therein was prepared in the same manner as in Example 1, except that manganese carbonate was used instead of iron oxide.

[Example 3]

Titanium oxide catalyst containing chromium (III) oxide was prepared in the same manner as in Example 1, except that iron oxide (III) was used instead of iron oxide.

[Example 4]

A titanium dioxide catalyst containing tin oxide (II) was prepared in the same manner as in Example 1, except that tin oxide (II) was used instead of iron oxide.

[Example 5]

A titanium dioxide catalyst containing tin oxide (IV) was prepared in the same manner as in Example 1, except that tin oxide (IV) was used instead of iron oxide.

[Example 6]

A titanium dioxide catalyst containing copper oxide was prepared in the same manner as in Example 1, except that copper oxide was used instead of iron oxide.

[Example 7]

A titanium dioxide catalyst containing zinc oxide was prepared in the same manner as in Example 1, except that zinc oxide was used instead of iron oxide.

[Example 8]

A titanium dioxide catalyst containing cobalt oxide was prepared in the same manner as in Example 1, except that cobalt oxide was used instead of iron oxide.

[Example 9]

A titanium dioxide catalyst in which anion oxyhydroxide was incorporated was prepared in the same manner as in Example 1 using anion oxyhydroxide (? -FeO (OH) 2) instead of iron oxide.

[Example 10]

A titanium dioxide catalyst containing manganese (II) oxide was prepared in the same manner as in Example 1, except that manganese oxide (II) was used instead of iron oxide.

[Example 11]

A titanium dioxide catalyst containing manganese (III) oxide was prepared in the same manner as in Example 1, except that manganese oxide (III) was used instead of iron oxide.

[Example 12]

A titanium dioxide catalyst containing manganese oxide (IV) was prepared in the same manner as in Example 1, except that manganese oxide (IV) was used instead of iron oxide.

[Example 13]

A titanium dioxide catalyst having copper carbonate incorporated therein was prepared in the same manner as in Example 1 except that copper carbonate was used instead of iron oxide.

[Example 14]

A titanium dioxide catalyst having zinc carbonate incorporated therein was prepared in the same manner as in Example 1, except that zinc carbonate was used instead of iron oxide.

[Example 15]

A titanium dioxide catalyst having iron carbonate incorporated therein was prepared in the same manner as in Example 1, except that iron carbonate was used instead of iron oxide.

[Example 16]

A titanium dioxide catalyst containing copper hydroxide was prepared in the same manner as in Example 1 using copper hydroxide instead of iron oxide.

[Example 17]

A titanium dioxide catalyst containing zinc hydroxide was prepared in the same manner as in Example 1 using zinc hydroxide instead of iron oxide.

[Example 19]

Weight of iron oxide and iron oxide were weighed such that the weight ratio of iron oxide was 0.01, 0.03, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0, 2.0 and 5.0% Add a small amount of ethyl alcohol and mix well.

Put on a speed adjustable ball mill, ball mill for 24-48 hours, dry at 100-110 ℃, crush with mortar and keep fine.

The catalyst was placed in a ceramic vessel and then placed in a furnace and calcined at 550-1100 ° C for 2-8 hours to prepare a titanium dioxide catalyst containing iron oxide.

[Example 20]

A titanium dioxide catalyst having manganese carbonate incorporated therein was prepared in the same manner as in Example 19, except that manganese carbonate was used instead of iron oxide.

[Example 21]

A titanium dioxide catalyst containing chromium (III) oxide was prepared in the same manner as in Example 19 using chromium oxide (III) instead of oxide.

[Example 22]

In the same manner as in Example 19, tin oxide (II) was used instead of iron oxide,

To prepare a titanium dioxide catalyst incorporating stones (II).

[Example 23]

A titanium dioxide catalyst containing tin oxide (IV) was prepared in the same manner as in Example 19 using tin oxide (IV) instead of iron oxide.

[Example 24]

A titanium dioxide catalyst containing copper oxide was prepared in the same manner as in Example 19 using copper oxide instead of iron oxide.

[Example 25]

A titanium dioxide catalyst having zinc oxide incorporated therein was prepared in the same manner as in Example 19 using zinc oxide instead of iron oxide.

[Example 26]

A titanium dioxide catalyst containing cobalt oxide was prepared in the same manner as in Example 19 using cobalt oxide instead of iron oxide.

[Example 27]

A titanium dioxide catalyst incorporating anion hydroxide was prepared in the same manner as in Example 19 using anion hydroxide (? -FeO (OH) 2) instead of iron oxide.

[Example 28]

A titanium dioxide catalyst containing manganese (II) oxide was prepared in the same manner as in Example 19, except that manganese oxide (II) was used instead of iron oxide.

[Example 29]

A titanium dioxide catalyst containing manganese (III) oxide was prepared in the same manner as in Example 19, except that manganese oxide (III) was used instead of iron oxide.

[Example 30]

A titanium dioxide catalyst containing manganese oxide (IV) was prepared in the same manner as in Example 19 using manganese oxide (IV) instead of iron oxide.

[Example 31]

A titanium dioxide catalyst having copper carbonate incorporated therein was prepared in the same manner as in Example 19 using copper carbonate instead of iron oxide.

[Example 32]

A titanium dioxide catalyst having zinc carbonate incorporated therein was prepared in the same manner as in Example 19 using zinc carbonate instead of iron oxide.

[Example 33]

A titanium dioxide catalyst having iron carbonate incorporated therein was prepared in the same manner as in Example 19 using iron carbonate instead of iron oxide.

[Example 34]

A titanium dioxide catalyst containing copper hydroxide was prepared in the same manner as in Example 19 using copper hydroxide instead of iron oxide.

[Example 35]

A titanium dioxide catalyst containing zinc hydroxide was prepared in the same manner as in Example 19 using zinc hydroxide instead of iron oxide.

[Example 36]

A titanium dioxide catalyst having iron hydroxide incorporated therein was prepared in the same manner as in Example 19 using iron hydroxide instead of iron oxide.

(Treatment Example 1)

0.8 g of the catalyst obtained in Example 1 (using 0.4 wt% of iron oxide) was added to 8.0 liters of wastewater containing 1000 ppm of pyridine, which is a decomposable organic substance, and reacted in a reactor equipped with a 20 watt UV lamp having a wavelength of 300-500 nm for 60 hours at room temperature As a result, 98% or more of pyridine was decomposed.

The UV-visible light absorption spectra of the wastewater before and after treatment with the catalyst are shown in FIG. 3 and FIG. The peak at about 250 nm is the peak corresponding to the pyridine. From this figure, it can be clearly seen that the catalyst of the present invention effectively decomposes pyridine, which is a decomposable organic substance.

(Comparative Processing Example 1)

It took 120 hours to treat pyridine with titanium dioxide itself, which did not incorporate iron oxide, in the same manner as in Process Example 1. [

(Process Example 2)

1.0 g of the catalyst (0.4 wt% of manganese carbonate) obtained in Example 2 was reacted in 1 L of the wastewater containing 1000 ppm of phenol, which is a decomposable organic substance, in a reactor equipped with a UV lamp. As a result, 99% Disassembled.

(Treatment Example 3)

3.0 g of the catalyst obtained in Example 5 (using 0.4 wt% of oxidized tritium (IV)) was adjusted to pH 8.1 with 3.5 L of a wastewater containing 900 ppm of a decomposable organic substance, and then reacted in a reactor equipped with a UV lamp for 6 hours The COD (Cr) value decreased by 15% and the COD value decreased by 99.0% after 48 hours.

(Process Example 4)

1.0 g of the catalyst obtained in Example 8 (using 0.4 wt% of cobalt oxide) was reacted in 1 L of a wastewater containing 100 ppm of nitrobenzene for 120 hours in a reactor equipped with a UV lamp, whereby nitrobenzene was completely decomposed. Gas chromatograms of wastewater before and after treatment with catalyst are shown in FIG. 5 and FIG. 6. The large peak is the peak corresponding to the reference material and the small peak is the peak corresponding to the nitrobenzene. From this figure, it can be clearly seen that the catalyst of the present invention effectively decomposes nitrobenzene, which is a decomposable organic substance.

(Process Example 5)

Treated wastewater containing 1000 ppm of isothiazolone (trade name: SKY BIO), which greatly affects the activated sludge, with the catalyst (0.4 wt% of chromium oxide used) obtained in Example 3 for 2 hours in the same manner as in Example 3, The thiazolone compound was completely decomposed.

Liquid chromatograms of wastewater before and after treatment with catalyst are shown in FIG. 7 and FIG. From this figure, it can be clearly seen that the catalyst of the present invention effectively decomposes isothiazolone, which is a decomposable organic substance.

(Treatment Example 6)

1.0 g of the catalyst obtained in Example 10 (using 0.4 wt% of manganese (II) oxide) was placed in a reactor equipped with a UV lamp and reacted for 240 hours in 1 L of waste water containing 1000 ppm of a decomposable organic substance acetonitrile. And decreased by 99.8%.

(Process Example 7)

The catalysts obtained in Examples 10 to 18 (0.4 weight% mixed compound

, And the wastewater containing acetone, pyridine, isopropyl alcohol, toluene, and methanol was treated in the same manner as above. However, most of the wastewater containing the acetone, pyridine, isopropyl alcohol, toluene and methanol was decomposed within 240 hours.

(Process Example 8)

The wastewater containing acetone, pyridine, isopropyl azole, toluene and methanol was treated with the catalysts obtained in Examples 19 to 36 (using the mixed compound of 0.4 wt%) in the same manner as described above. As a result, , But most of them were disintegrated within 150 hours.

This result shows that the compound of metatitanic acid mixed with oxides, carbonates or hydroxides in the mixing process has better catalytic activity than the compound made by mixing oxide, carbonates or hydroxides with titanium dioxide.

(Comparative Processing Example 2)

When titanium dioxide alone was used instead of the incorporated catalyst, the decomposition time was increased to 2 to 10 times in the same manner as in Processes 2 to 7.

The above Processes 1 to 8 are the results of the tests with the refractory organic substances, and the following Processes 9 to 12 are actual wastewater tests, , And the effect on microorganisms.

(Process Example 9)

0.5 g of the catalyst obtained in Example 11 (using 0.4 wt% of manganese oxide (III)) was added to 5 L of raw wastewater of a textile company S company having a pH of 5.5 and an initial COD (Cr) value of 4650 ppm, and 10% sodium hydroxide After adjusting the pH to 7.5 with a solution, the UV lamp with a wavelength of 300-500 nm and a wavelength of 300-500 nm was applied to the flow type reactor at a flow rate of 3 L / min. After the reaction, the odor completely disappeared after 30 minutes. Thereafter, the pH dropped to 6.2, the COD value decreased by 60%, and the effect on the activated sludge was evaluated. As a result, the number of sludge varied and the number of bacteria increased four times.

(Comparative Processing Example 3)

The treatment with titanium dioxide instead of the catalyst incorporated in the same manner as in Process Example 9 resulted in a 45% reduction in the COD value after 10 hours of reaction, although the cracking did not disappear completely.

(Treatment Example 10)

0.8 g of the catalyst (0.4 wt% of manganese oxide (III)) obtained in Example 11 was added to 8 L of raw wastewater having a pH of 10.0 and an initial COD (Mn) value of 700 ppm and a 20 watt UV lamp : 380 nm), the reaction was carried out at a flow rate of 3 L / min. As a result, the red color completely disappeared after 60 minutes, the pH dropped to 8.0 after 10 hours, and the COD value decreased by 70%.

(Comparative Processing Example 4)

Instead of 0.8 g of the catalyst containing manganese oxide in the same manner as in Process Example 10, 0.8 g of titanium dioxide was treated with 0.8 g of the catalyst, and the color did not completely disappear. As a result of the reaction for 10 hours, the COD value decreased by 28%.

(Process Example 11)

5.5 g of the catalyst obtained in Example 19 (using 0.4 wt.% Of iron oxide) was added to 5.5 L of coating wastewater of Company D having a COD (Cr) value of 5690 ppm and a wastewater circulatingly used. As a result, after 30 minutes, the characteristic odor of thinner as a coating solvent disappeared and the COD value decreased by 48% after 2 hours. The results of the evaluation of the influence on the activated sludge show the same effect as in the treatment example 9. [

(Comparative Processing Example 5)

As a result of treating with 30 g of titanium dioxide in place of 5.5 g of the iron oxide-containing catalyst in the same manner as in Example 11, the specific odor of the thinner remained. As a result of the reaction for 2 hours, the COD value was reduced by 22%.

(Process Example 12)

The same results as in Treatment Example 11 were obtained in the case of coating wastewater of Company A, which has a strong odor and circulates the wastewater.

As can be seen from the above treatment examples and comparative treatment examples, the treatment efficiency according to the production method of the present invention was very low while the amount of the catalyst was small. In addition, when one or more of oxides, carbonates, and hydroxides are mixed in titanium dioxide according to the production method of the present invention, the refractory materials can be effectively decomposed and the reaction time can be shortened . Further, in the present invention, it is not necessary to supply oxygen gas during wastewater treatment, and it is also possible to treat ordinary wastewater which flows well at a room temperature without any consideration of pressure, and is not dangerous. It is economical because the titanium oxide which is inexpensive and cheap is used. Therefore, the process cost is much lower and economical, and since the size of the catalyst according to the present invention is larger than that of the existing catalyst, it is easy to filter and reuse it after wastewater treatment.

Claims (13)

Wherein at least one of oxides, carbonates, and hydroxides is added to titanium dioxide or metatitanic acid, and the mixture is treated with a ball mill, followed by calcination at 550 to 1100 占 폚. The catalyst for treating wastewater according to claim 1, wherein 0.01 wt% to 5.0 wt% of at least one of oxide, carbonate, and hydroxide is incorporated. The method of claim 1, wherein the oxide is selected from the group consisting of iron oxide, chromium oxide (III), tin oxide (II), tin oxide (IV), copper oxide, zinc oxide, cobalt oxide, manganese oxide (II) And manganese oxide (IV). ≪ RTI ID = 0.0 > 11. < / RTI > The method according to claim 1, wherein the carbonate is at least one selected from the group consisting of manganese carbonate, copper carbonate, zinc carbonate, and iron carbonate. The method for producing a catalyst for treating wastewater according to claim 1, wherein the hydroxide is at least one selected from the group consisting of aion oxyhydroxide (? -FeO (OH) 2), copper hydroxide, zinc hydroxide and iron hydroxide. The method for producing a catalyst for treating wastewater according to any one of claims 1 to 5, wherein the calcination time is 2 to 14 hours. The method for producing a catalyst for treating wastewater according to claim 6, wherein the amount of at least one of oxides, carbonates, and hydroxides added to the titanium dioxide or the metatitanic acid is 0.01 wt% to 5.0 wt%. (a) adding wastewater to the catalyst obtained in (1) and mixing; (b) contacting the mixture with the catalyst while irradiating the mixture with light having a wavelength of 200-600 nm. 9. The method according to claim 8, wherein the contact between the wastewater and the catalyst in step (b) is carried out at room temperature. The method according to claim 8, wherein the wastewater comprises an aromatic compound. The method according to claim 8, wherein the wastewater comprises a nitrogen compound. 9. The method of claim 8, wherein the wastewater comprises a sulfur compound. 9. The method of claim 8, wherein the wastewater comprises an organohalogen compound.