JPH07232063A - Catalyst for treating waste water, its preparation and method for treating waste water using its catalyst - Google Patents

Abstract

PURPOSE:To establish a new method for treating waste water by a catalyst for treating the waste water contg. manganese oxide, iron oxide and/or a composite oxide of manganese and iron. CONSTITUTION:Treatment under a wet oxidation condition is performed by using a catalyst for treating waste water contg. each manganese and iron of oxide and/or a composite oxide. Namely, air fed from an oxygen contg. gas feeding line 8 is mixed into a waste water sent from a waste water feeding line 7. This gas-liq. mixture is introduced into a wet oxidation reaction tower 1 packed with a catalyst through a gas-liq. mixture feeding line 9 and wet oxidation treatment is performed by heating by means of an electric heater 4 and the treated water is cooled in a cooler 5 through a treated water line 10 and it is made to flow into a gas-liq. separator 6, wherein a liq. face control valve 12 is actuated by means of a liq. face controller LC and a pressure control valve 14 is actuated by means of a pressure controller PC to discharge the treated water from a treated water line 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment catalyst, a method for producing the same, and a wastewater treatment method using the catalyst. More specifically, the present invention relates to a chemical plant facility,
Plating industry equipment, leather production equipment, metal industry equipment, metal mining equipment, food production equipment, pharmaceutical production equipment, textile industry equipment, paper pulp industry equipment, dyeing dye industry equipment, electronics industry equipment, machine industry equipment, printing plate making equipment, It is used when purifying wastewater discharged from glass manufacturing equipment, photographic processing equipment, etc. In particular, among the methods for purifying wastewater, the catalyst is used when purifying the wastewater by a method of catalytic wet oxidation treatment, and is a catalyst for decomposing organic matter and / or inorganic COD components in the wastewater in this case, and a method for producing the catalyst. Further, the present invention relates to a method for purifying the wastewater, which comprises subjecting the wastewater to a wet oxidation treatment in the presence of the catalyst.

[0002]

2. Description of the Related Art Conventionally, as a wastewater treatment method, a biological treatment method generally called an activated sludge method, a combustion treatment method by incineration, and a non-catalytic wet oxidation treatment method called a Chimmerman method are known. .

The biological treatment method requires a long time for decomposing organic substances and the like, and requires complicated steps for treating a hardly decomposable nitrogen-containing compound such as ammonia, and moreover, microorganisms such as algae and bacteria. Since it is necessary to dilute the wastewater to a concentration suitable for the growth of, or adjust the wastewater to a pH suitable for the growth of microorganisms, there is a drawback that the installation area of the treatment facility becomes large.

[0004] The combustion treatment method has the drawbacks such as a high fuel cost for combustion and the problem of secondary pollution such as exhaust gas.

The non-catalytic wet oxidation treatment method called the Chimmerman method is a method of treating wastewater in the presence of oxygen gas at high temperature and high pressure to oxidize or oxidatively decompose organic substances and / or inorganic COD components and the like. Although it is a treatment method, it generally has a low treatment efficiency, and thus requires a secondary treatment facility in many cases.

Therefore, a method using various catalysts has been proposed mainly for the purpose of improving the treatment efficiency in the wet oxidation treatment method. In particular, a wet oxidation method using a solid catalyst (hereinafter also referred to as catalytic wet oxidation treatment)
Has attracted particular attention in recent years from the standpoint of its high wastewater purification and excellent economic efficiency. The conventional catalysts proposed here are palladium, platinum, and other noble metals such as alumina,
It is a catalyst supported on a carrier such as silica, silica gel or activated carbon (JP-A-49-44556 and JP-A-49-941).
57).

[0007] However, in general, wastewater rarely contains the same kinds of components, and for example, nitrogen-containing compounds, sulfur-containing compounds, in addition to nitrogen atoms, sulfur atoms and organic compounds containing no halogen atom, In many cases, halogen-containing compounds are contained in wastewater. Therefore,
Often, the use of the above catalysts alone does not adequately treat these components.

For example, in the above-mentioned conventional methods, organic nitrogen compounds such as amine compounds, amide compounds, amino acid compounds, etc., which are often contained in wastewater of various chemical plants, or nitrogen-containing compounds such as inorganic nitrogen compounds such as ammonia, hydrazine, etc. Wastewater containing compounds; Inorganic sulfur compounds such as thiosulfuric acid and sulfurous acid and sulfides, which are often contained in petrochemical and photographic wastewater, and sulfur-containing organic sulfur compounds, which are often used in surfactants and solvents. Wastewater containing compounds; various treatments such as wastewaters containing halogen-containing compounds such as organic halogen compounds, which are often contained in wastewaters such as detergents and fine chemicals, have not been particularly efficient in treatment. Further, in the conventional wet oxidation treatment of the catalyst described above, according to the study by the present inventors, long-term use causes a decrease in the strength of the catalyst and crushing and pulverization, which may cause dissolution of the catalyst. Inferior and not practical.

As another technique for solving the problem, a method using titania or zirconia as a carrier has been proposed (Japanese Patent Laid-Open No. 58-64188). According to this, a catalyst in which a noble metal compound such as palladium and platinum, a heavy metal compound such as iron and cobalt is supported on a spherical or cylindrical titania or zirconia carrier, and a catalyst having excellent strength as compared with a conventional carrier is disclosed. Is listed. However, none of these catalysts has been sufficiently satisfactory in catalytic activity and durability.

In order to solve these problems, the present inventors have already proposed a catalyst containing a composite oxide of titanium and zirconium, a noble metal such as palladium and platinum, and / or a heavy metal such as cobalt and nickel. Wastewater treatment method used (Japanese Patent Publication No. 3-34997), oxides containing at least one element selected from the group consisting of iron and titanium, silicon and zirconium, and noble metals such as palladium and platinum, and / or A catalyst containing heavy metals such as cobalt and nickel and a method for treating wastewater using the catalyst (Japanese Patent Laid-Open No. 3-138027) have been proposed. Although all of these catalysts have high catalytic activity and high durability, more preferable results can be obtained from the viewpoints of economic efficiency in treating wastewater and improvement of purification efficiency.

Generally, in the catalytic wet oxidation treatment of waste water, a reaction tube made of stainless steel or the like is used from the viewpoint of cost, but since this is vulnerable to corrosion in the acidic region, the pH of the waste water is adjusted to the alkaline region. In many cases, it is used for the reaction. In particular, wastewater containing a nitrogen-containing compound, a sulfur-containing compound, and a halogen-containing compound produces nitrate ions, sulfate ions, halide ions, etc. by the treatment, and therefore treatment in an acidic region is often difficult. However, in this case, some of these catalysts do not have sufficient durability and treatment activity when used in an alkaline region, and a catalyst having sufficient durability and treatment activity even when the wastewater is in an alkaline region cannot be used. Is desired.

[0012]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to propose a novel wastewater treatment catalyst, a method for producing the same, and a wastewater treatment method using the catalyst.

More specifically, the object of the present invention is to treat wastewater by various methods such as wet oxidation method, ozone method, ultraviolet method, and electrolysis method. In particular, the catalyst of the present invention is a catalyst for wastewater treatment suitable for a wet oxidation treatment method using a solid catalyst, a method for producing the same, and treatment of wastewater using the catalyst. To propose a method.

More specifically, in the present invention, particularly in the catalytic wet oxidation treatment, in addition to the hydrocarbon-based organic substance containing no nitrogen atom, sulfur atom, or halogen atom, a nitrogen-containing compound, a sulfur-containing compound, a halogen-containing compound, etc. Is difficult to treat, in other words, wastewater containing harmful substances that pollute rivers such as any kind of organic matter and / or inorganic COD components can be treated with high purification efficiency and economically. The present invention provides a wastewater treatment method having excellent properties, which makes it possible to use a wastewater treatment catalyst for wet oxidation treatment, which has high catalytic activity and excellent durability and alkali resistance, a method for producing the same, and a catalyst for the same. The purpose is to provide a method for treating the wastewater.

Still another object of the present invention is to provide a catalyst for wastewater treatment which has a higher catalytic activity and is excellent in durability and alkali resistance, and particularly has a catalytic activity with respect to organic nitrogen compounds, sulfur-containing compounds and organic halogen-containing compounds. It is an object of the present invention to provide a method for treating wastewater by catalytic wet oxidation treatment, which is related to a method for using a catalyst for treating wastewater, which is highly durable and excellent in alkali resistance.

[0016]

Various heavy metals and noble metal elements have been conventionally known to be effective as catalytically active components of wastewater treatment catalysts. However, the present inventors have solved the above problems. As a result of diligent research to solve the problems, (1) When the combined use of the respective oxides and / or complex oxides of manganese and iron as the catalytically active components of the wastewater treatment catalyst, it is possible to specifically treat various wastewaters. The catalyst activity is improved, and the durability and the alkali resistance are excellent. (2) When the titanium and / or zirconium oxide and / or the composite oxide is also used in combination, the above effect is further promoted, and ( 3) If at least one kind of metal of an element selected from the group consisting of ruthenium, rhodium, palladium, iridium and platinum and / or a compound of the metal is used together, the above effect is further promoted. Are possible, (4) oxides and / or composite oxide of manganese as a catalyst component, x = 1.5 to oxidation number of manganese in terms in the form of MnOx
The durability and treatment activity of the catalyst are specifically enhanced in the range of 2.0. (5) Oxide of manganese and iron oxide, or oxidation of metals of iron, titanium and / or zirconium Intimately mixed form such as forming a complex oxide with the substance, more specifically enhances the durability and treatment activity of the catalyst.
(6) It has been found that the oxide and / or complex oxide of titanium and / or zirconium can enhance the effect by being mixed closely with the oxide and / or complex oxide of manganese and / or iron, Thus, the present invention has been completed. Thus, the present invention provides the following wastewater treatment catalyst and its production method.

(1) A wastewater treatment catalyst containing an oxide of manganese and an oxide of iron and / or a composite oxide of manganese and iron.

(2) The catalyst for treating wastewater according to (1) above, further containing an oxide and / or a composite oxide of titanium and / or zirconium, respectively.

(3) The wastewater treatment catalyst according to the above (2), wherein titanium and / or zirconium is intimately mixed with manganese and / or iron.

(4) Waste water according to the above (1) to (3), further containing at least one metal of the element selected from the group consisting of ruthenium, rhodium, palladium, iridium and platinum and / or a compound of the metal. Processing catalyst.

(5) In the catalyst described in (1) above,
Manganese oxide and / or complex oxide is MnO2
The amount is 0.05 to 50% by weight, and the iron oxide and / or the composite oxide is 9 as Fe2O3.
The wastewater treatment catalyst according to (1) above, which is 9.95 to 50% by weight.

(6) In the catalyst described in (2) or (3) above, the manganese oxide and / or the composite oxide is 0.05 to 50% by weight in terms of MnO2, and the iron oxide and / or The composite oxide is 95 to 30% by weight in terms of Fe2O3, and titanium and / or
Or zirconium oxide and / or complex oxide is 5 to 70% by weight in terms of TiO2 and ZrO2.
(The oxide and / or composite oxide of at least one metal selected from the group consisting of iron, titanium and zirconium is 99.95 to 50% by weight in terms of Fe2O3, TiO2 and ZrO2.) A certain catalyst for wastewater treatment according to the above (2) or (3).

(7) The above (1), (2), (3),
100 parts by weight of the catalyst according to (5) or (6),
Furthermore, at least one kind of metal of an element selected from the group consisting of ruthenium, rhodium, palladium, iridium, and platinum and / or a compound of the metal is 0.0
(1) above, which is contained in an amount in the range of 5 to 10 parts by weight.
(6) The wastewater treatment catalyst according to the above.

(8) The manganese oxide and / or the composite oxide is x = 1.5-converted in the form of MnOx.
The wastewater treatment catalyst according to the above (1) to (7), which is in the range of 2.0.

(9) The catalyst has a BET specific surface area of 5 to 2
The catalyst for treating wastewater according to the above (1) to (7), which has a volume of 00 m2 / g.

(10) At least a step of heat-treating the manganese oxide precursor and the iron oxide precursor and / or the manganese-iron composite oxide precursor at 300 ° C. or higher in an oxidizing atmosphere is adopted. The above (1), (3),
(5) or the method for producing the catalyst for treating wastewater according to (6).

(11) A precursor of titanium and / or zirconium oxide and / or composite oxide
The method for producing a wastewater treatment catalyst according to (2), (3) or (6), wherein at least a step of performing heat treatment at 300 ° C. or higher in an oxidizing atmosphere is adopted.

(12) At a treatment temperature of 140 ° C. or higher and lower than 370 ° C. and a pressure at which the waste water retains the liquid phase, the above (1) to
(11) A method for treating wastewater, which comprises subjecting the wastewater to a wet oxidation treatment with an oxygen-containing gas in the presence of the catalyst according to (11).

(13) The method for treating wastewater according to the above (12), wherein the wastewater contains at least one of a nitrogen-containing compound, a sulfur-containing compound and a halogen-containing compound.

The present invention will be described in detail below.

[0031]

The composition of the first wastewater treatment catalyst of the present invention contains the respective oxides and / or complex oxides of manganese and iron. Particularly preferably, manganese and iron are intimately mixed, and more preferably, manganese and iron are intimately mixed such that they have the form of a complex oxide.

By using manganese and iron together, a catalyst having excellent catalytic activity and durability can be obtained, and the ratio of each component is not particularly limited, but preferably, the manganese oxide and / or the composite oxide is contained in the whole catalyst. Mn
It is 0.05 to 50% by weight as O2 conversion, and the iron oxide and / or the composite oxide is 9% as Fe2 O3 conversion.
9.95 to 50% by weight. Preferably, the manganese oxide and / or the composite oxide is 0.5 to 30% by weight as MnO2 and the iron oxide and / or the composite oxide is 99.5 to 70% by weight as Fe2O3. Preferably manganese oxide and /
Alternatively, the composite oxide is 1 to 20% by weight in terms of MnO2.
And iron oxide and / or complex oxide is Fe2O3
It has a composition of 99 to 80% by weight in terms of conversion. When the proportion of manganese oxide and / or complex oxide is less than 0.05% by weight, the activity of the catalyst is sufficient when the catalyst is used under the conditions of wet oxidation treatment of the catalyst according to the present invention. If it is more than 50% by weight, the catalytic activity according to the present invention is sufficient when the catalyst is used under the conditions of the wet oxidation treatment, but it is a machine for maintaining the shape of the catalyst. It has a drawback that the physical strength is lowered. Therefore, the use ratios of the manganese oxide and / or the composite oxide and the iron oxide and / or the composite oxide are determined from the above preferable range in consideration of various conditions that the catalyst should have.

The composition of the second wastewater treatment catalyst of the present invention is:
The above-mentioned first catalyst further contains titanium and / or zirconium oxides and / or composite oxides. By using the respective oxides and / or complex oxides of titanium and / or zirconium in combination, the effect of further improving the mechanical strength for maintaining the catalyst shape in the first catalyst of the present invention can be obtained. Particularly preferably, manganese and / or iron and titanium and / or zirconium are intimately mixed, and more preferably, iron and titanium and / or zirconium are intimately mixed such that they have a form of a complex oxide. It is a mixture.

The ratio of each component is not particularly limited, but preferably, in the whole catalyst, manganese oxide and / or
Alternatively, the complex oxide is 0.05 to 50 in terms of MnO2.
% By weight, the iron oxide and / or the composite oxide is 95 to 30% by weight in terms of Fe2O3, and the titanium and / or zirconium oxide and / or the complex oxide is 5 in terms of TiO2 and ZrO2. ~
70% by weight (the oxide and / or composite oxide of at least one metal selected from the group consisting of iron, titanium and zirconium is 99.95 to 50% by weight in terms of Fe2O3 conversion, TiO2 conversion and ZrO2 conversion).
It is). If the oxide and / or composite oxide of titanium and / or zirconium is less than 5% by weight, the effect of adding these components is low, and if it exceeds 70% by weight, the activity of the catalyst may be decreased. Durability and alkali resistance are reduced.

Preferably, the manganese oxide and / or the composite oxide is 0.5 to 30% by weight in terms of MnO2 with respect to the entire catalyst, and the iron oxide and / or
Alternatively, the composite oxide is 93 to 40% by weight in terms of Fe2O3, and the oxide of titanium and / or zirconium and / or the complex oxide is in terms of TiO2.
7 to 60% by weight as ZrO2 conversion (the oxide and / or composite oxide of at least one metal selected from the group consisting of iron, titanium and zirconium is the total in terms of Fe2O3 conversion, TiO2 conversion and ZrO2 conversion. 99.5 to 70% by weight).

Further, the most preferable composition of the second catalyst of the present invention is such that the manganese oxide and / or the composite oxide is 1 to 20% by weight in terms of MnO2 based on the whole catalyst, and the iron oxide and / or the oxide is Or the complex oxide is Fe2O3
The conversion is 90 to 50.0% by weight, and the oxide of titanium and / or zirconium and / or the composite oxide is 10 to 10 in terms of ZrO2 in terms of TiO2.
50.0% by weight (the oxide and / or composite oxide of at least one metal selected from the group consisting of iron, titanium and zirconium is TiO2 in terms of Fe2O3).
As a conversion, a total of 99-80 as ZrO2 conversion
% By weight).

The third wastewater treatment catalyst of the present invention is the same as the above-mentioned first catalyst except that a metal of an element selected from the group consisting of ruthenium, rhodium, palladium, iridium and platinum and / or a compound of the metal (hereinafter (Generally referred to as noble metal elements) is included.

In a fourth wastewater treatment catalyst of the present invention, at least one metal of the element selected from the group consisting of ruthenium, rhodium, palladium, iridium and platinum and / or a compound of the metal is added to the second catalyst. It includes.

The noble metal elements are each contained in an amount of 0.05 with respect to the total amount (100 parts by weight) of the first catalyst or the second catalyst.
It is effective that the content is in the range of 10 to 10 parts by weight, preferably 0.1 to 2.5 parts by weight. If the amount is less than 0.05 parts by weight, the effect of precious metal elements is small and the activity of the catalyst is not improved. If the amount is more than 10 parts by weight, the performance of the catalyst is improved in proportion to the increase in the catalyst cost. Is not economically preferable because it cannot be obtained. Moreover, the durability of the catalyst and the mechanical strength of the catalyst are also reduced.

Any of the catalysts according to the present invention may contain substances and impurities contained in the precursor of the catalyst and substances and impurities mixed in during the catalyst manufacturing process as impurities. For example, there are substances such as silicon, aluminum, sulfur, halogen, sodium, potassium, calcium, magnesium, nitrogen, chromium, nickel, etc., but even if they are contained in a trace amount, they greatly affect the physical properties of the catalyst according to the present invention. Unless otherwise provided, the effect as a catalyst is not particularly hindered.

The catalyst of the present invention can be molded into various shapes such as pellets, granules, spheres or rings, or an integral structure such as a honeycomb, and used. It can also be used by supporting it on an inorganic oxide carrier, a metal carrier or the like having the above shape. Further, when the catalyst is molded, an inorganic oxide can be added to the catalyst to mold it. In this case, the inorganic oxide can be mixed with the catalyst component according to the present invention in the same manner as the molding aid such as glass fiber, and molded and used. In this case, the moldability and mechanical properties of the catalyst It is effective in improving strength and the like.

As the inorganic oxide, oxides containing cobalt, nickel, chromium, copper, tin, niobium, barium, lanthanum, cerium, praseodymium, aluminum, silicon, sodium, potassium, etc., composite oxides thereof, glass fiber Etc. These inorganic oxides can be mixed with the catalyst component of the present invention and molded before use. In this case, they are effective for improving the moldability and mechanical strength of the catalyst.

When these inorganic oxides are mixed with the catalyst component and used after molding, they are preferably 70 to 0.01% by weight, more preferably 10 to 0.01% by weight, based on the total amount of the catalyst.
It is 0.1% by weight. If it exceeds 70% by weight, the effect as a catalyst is reduced, and if it is less than 0.01% by weight, it can be regarded as an impurity.

These inorganic oxide carriers (excluding oxides of elements of titanium, zirconium, iron and manganese) or metal carriers are used when they are used by carrying the catalyst component according to the present invention. Preferably 9 with respect to the total amount
9.5-20% by weight, more preferably 95-50% by weight
Is effective when If it exceeds 99.5% by weight, the effect as a catalyst is reduced, and if it is less than 20% by weight, the effect as a carrier is small and the mechanical strength for maintaining the shape as a catalyst is low. It will decrease.

The granular and spherical catalysts according to the present invention preferably have an average particle size of 1 to 10 mm, more preferably 2 to 7 mm. If the average particle size is less than 1 mm, the pressure loss in the reaction tower when the catalyst is packed increases, and
When it is larger than mm, a sufficient geometric surface area cannot be obtained, the contact efficiency is lowered, and a sufficient processing ability cannot be obtained.

The pellet-shaped catalyst according to the present invention includes
The average diameter is preferably 1 to 10 mm, more preferably 3 to 8
In mm, the average length is preferably 2 to 15 mm, more preferably 3 to 10 mm. If the average diameter is less than 1 mm or the average length is less than 2 mm, the pressure loss increases, and the average diameter is greater than 10 mm or the average length is 15 mm.
If it is larger than the
The contact efficiency decreases, and sufficient processing capacity cannot be obtained.

The ring-shaped catalyst according to the present invention preferably has an average outer diameter of 4 to 15 mm, more preferably 6 to 1
2 mm, preferably 2 to 15 mm in average length, more preferably 3 to 10 mm, and preferably 0.5 to 5 in average wall thickness.
mm, more preferably 1 to 4 mm. Average outer diameter is 4
If the average length is less than 2 mm or the average length is less than 2 mm, it is difficult to increase the pressure loss and formability, and the average outer diameter is 1
When it is larger than 5 mm or the average length is larger than 15 mm, a sufficient geometric surface area cannot be obtained, contact efficiency is lowered, and sufficient processing capacity cannot be obtained. Further, when the average thickness is less than 0.5 mm, the pressure loss is small, and there is an advantage that the weight of the catalyst can be reduced, but the mechanical strength of the catalyst may decrease, and when the average thickness exceeds 5 mm. Mechanical strength is sufficient, but a sufficient geometric surface area cannot be obtained, contact efficiency decreases, and sufficient processing capacity cannot be obtained.

Regarding the shape of the honeycomb-shaped catalyst according to the present invention, the through-hole has an equivalent diameter of 2 to 20 mm and a cell wall thickness of 0.
A range of 1 to 3 mm and a porosity of 50 to 90% is preferable. Further, it is more preferable that the equivalent diameter of the through hole is in the range of 2.5 to 15 mm, the cell wall thickness is in the range of 0.5 to 3 mm, and the open area ratio is in the range of 50 to 90%. The equivalent diameter of the through hole is 2m
If it is less than m, the pressure loss is large, and if the equivalent diameter exceeds 20 mm, the pressure loss is small.
Contact efficiency decreases and adsorption efficiency decreases. Further, when the cell wall thickness is less than 0.1 mm, the pressure loss becomes small and the catalyst can be made lighter, but the mechanical strength of the catalyst may decrease. When the cell wall thickness exceeds 3 mm, the mechanical strength is sufficient, but the pressure loss may increase. The aperture ratio is preferably in the range of 50 to 90% for the same reason as above.

The BET specific surface area of the catalyst according to the present invention is 5
It is not particularly limited as long as it is 200 m2 / g, but it is preferably 10 to 150 m2 / g, and more preferably 30 to 120 m2 / g. If it is less than 5 m2 / g, the contact efficiency between the substance to be treated and the catalyst decreases,
The activity of the catalyst is reduced, and it is 200m2 / g.
If it is larger than this, the mechanical strength of the catalyst becomes weak.

Next, a method for producing the wastewater treatment catalyst of the present invention will be described.

The method for producing the catalyst according to the present invention is not particularly limited, and the catalyst can be produced by various production methods. Basically, a compound containing a manganese element and a compound containing an iron element are mixed and then fired in an oxidizing atmosphere.

The method of mixing the compound containing the manganese element and the compound containing the iron element will be specifically described below as an example.

(1) An aqueous solution of a compound containing an element of manganese and an aqueous solution of a compound containing an element of iron are mixed and the pH is adjusted with an alkali such as aqueous ammonia or an aqueous solution of sodium hydroxide to convert the above compound into a hydroxide. Co-precipitate.
That is, it is prepared by the coprecipitation method.

(2) Gel-like or solid hydroxide or manganese-containing compound such as hydroxide, nitrate, carbonate, organic acid salt or chloride, and gel-like or solid water containing iron element Compounds such as oxides, nitrates, organic acid salts, chlorides and oxides are intimately kneaded and prepared by a kneading method.

(3) Prepared by an addition method in which an aqueous solution of a compound containing a manganese element is added to a compound such as a gel or solid hydroxide containing an iron element, a nitrate, an organic acid salt, a chloride or an oxide. Alternatively, it may be prepared by an addition method in which the elemental manganese and the elemental iron are added in opposite forms.

(4) Prepared by an impregnation method in which a molded body of a compound such as an oxide containing an iron element is impregnated with an aqueous solution of a compound containing a manganese element.

(5) Prepared by combining the above methods.

Methods such as the above can be mentioned.

Although not particularly limited, when a titanium and / or zirconium element is further introduced into the catalyst system or a noble metal element is introduced, the compound containing the element is added to the above (1). In the method described in (5) to (5), it may be added at any time. That is, a compound containing a manganese element, a compound containing an iron element, or a part of the compound may be replaced with a compound containing the element, or the compound may be used a plurality of times. Also, the order of addition of various compounds may be appropriately selected.

The catalyst according to the present invention forms an oxide and / or a composite oxide in the form of an intimate mixture of an oxide of manganese and an oxide of iron. In particular, it exhibits unique physical properties not seen with oxides. It is presumed from this that when the catalyst is used as a catalyst for treating wastewater, the catalyst activity and the durability and alkali resistance are significantly improved. In particular, in the catalyst according to the present invention, when the X-ray diffraction of the prepared catalyst was measured, the peak of the oxide believed to be manganese did not appear, or even if it appeared, the oxide of manganese was simply mixed with another oxide. However, it showed only a very weak peak intensity as compared with the X-ray diffraction peak. From this, it is assumed that the oxide of manganese of the catalyst according to the present invention does not simply exist as an oxide of manganese but forms a complex oxide with iron or iron, titanium and / or zirconium. It is considered that

Similarly, the oxide containing titanium and / or zirconium is intimately mixed with the oxide of manganese or iron, and / or the complex oxide of manganese and iron, and / or the complex oxide. It forms a substance, and by this, peculiar physical properties which are not seen in the oxide of each component alone are developed. This is presumed to have the effect that the mechanical strength of the catalyst is remarkably improved. However, the oxide of manganese forms an oxide or a complex oxide in the form of being intimately mixed with the oxide of iron, so that when the catalyst is used as a catalyst for treating wastewater, the catalytic activity is particularly improved and the durability is improved. And alkali resistance are remarkably improved. Therefore, the addition of the compound containing the element of titanium and / or zirconium is carried out after the compound containing the element of manganese and the compound containing the element of iron are formed in intimately mixed form, and further intimately mixed. However, methods other than the impregnation method are effective.

On the other hand, the catalyst according to the present invention contains a complex oxide of iron and titanium, a complex oxide of iron and zirconium, a complex oxide of titanium and zirconium, and a complex oxide of iron, titanium and zirconium. There are some catalysts. When these complex oxides are used, peculiar physical properties not seen when only a single oxide is used may be exhibited. In particular, a complex oxide of iron and titanium and / or zirconium exhibits unique physical properties not seen when using each oxide alone.
In comparison with iron oxides, when these composite oxides are used, when molded as a catalyst, the obtained molded product has a characteristic that a strong mechanical strength is obtained. In comparison with titanium oxide or zirconium oxide, when a catalyst was prepared as a catalyst for wet oxidation and subjected to wet oxidation treatment, the catalyst used as a composite oxide with iron was more alkaline resistant. The characteristics that are excellent and that the processing activity is improved appear. Therefore, in the catalyst according to the present invention, it is more preferable to use these elements as a composite oxide than to use these elements as a single oxide.

In this case, the complex oxide of iron and titanium, the complex oxide of iron and zirconium, the complex oxide of titanium and zirconium, and the complex oxide of iron, titanium and zirconium are obtained by intimately mixing these elements. The oxide is formed in the form of a circle. At this time, when the X-ray diffraction of these compounds is measured, the result of the X-ray diffraction of these compounds is
A peak as a composite oxide that cannot be obtained with a single oxide is obtained, or even if this peak is not obtained,
These oxides prepared separately by the same method can give weaker peak intensities than the X-ray diffraction peaks of the oxides simply mixed. From this fact, it is considered that a complex oxide is formed when the oxide is formed in the form of intimately mixing these elements.

Therefore, intimately mixing in the present invention means that a peak as a complex oxide which is not obtained by a single oxide is obtained in the result of X-ray diffraction of the product prepared as described above, or Even if this peak is not obtained, it is possible to obtain a weaker peak intensity than the X-ray diffraction peaks of the oxides obtained by simply mixing the oxides prepared by the same method separately. Say to mix.

As a precursor of manganese oxide and / or complex oxide, compounds containing various manganese can be used, and manganese hydroxide, nitrate, carbonate, organic acid salt, chloride, sulfuric acid. Compounds such as salt or active manganese dioxide, oxides such as electrolytic manganese dioxide,
Alternatively, there are complex oxides such as potassium permanganate. As a precursor of iron oxides and / or complex oxides, compounds such as hydroxides, nitrates, organic acid salts, chlorides and sulfates, or ferrous oxide, ferric oxide, ferric oxide, etc. Oxides. Examples of the precursor of titanium or zirconium oxide and / or complex oxide include compounds such as hydroxides, sulfates and chlorides, oxides such as titania and zirconia, and complex oxides such as barium titanate. is there. Precursors of noble metal elements include compounds such as hydroxides, nitrates, carbonates, organic acid salts, chlorides, sulfates, oxides and metals.

The molding method of the catalyst according to the present invention is not particularly limited, and the catalyst can be prepared by various molding methods, and a molding machine suitable for the intended shape of the catalyst is used.

Further, in producing the catalyst according to the present invention, for example, the precursor of the manganese oxide and / or the composite oxide obtained by the above-mentioned preparation methods (1) to (5) and the iron oxide and / or Or a complex oxide precursor, or a manganese oxide and / or complex oxide precursor and an iron oxide and / or complex oxide precursor, titanium and / or zirconium oxide and / or The complex oxide precursor and 300
It is preferable to perform heat treatment at a temperature of not less than ° C. That is, when preparing or molding the catalyst, it is effective to calcine at 300 ° C. or higher while supplying an oxygen-containing gas. Further, the firing time in this case is preferably 1 hour or more from the necessity of uniformly firing the catalyst. Further, the firing temperature is 300 to 550 [deg.] C., the firing time is 1 to 5 hours, and it is preferable to carry out the treatment in an oxygen-containing gas in order to obtain an oxidizing atmosphere.
Further, more preferably, the firing temperature is effectively 350 to 500 ° C., and the oxygen-containing gas is preferably air. Firing temperature is less than 300 ° C or firing time is 1
If it is less than the time, the mechanical strength of the catalyst is lowered, which is not preferable. If the temperature is higher than 550 ° C., the activity of the catalyst according to the present invention may be lowered and the durability of the catalyst may be lowered. The heat treatment of the catalyst in the oxidizing atmosphere in the method for producing the catalyst according to the present invention may be carried out in advance by using a firing furnace or the like, or may be carried out in the reaction tower after being filled in the wet oxidation reaction tower. It is not particularly limited.

The oxide of manganese and / or the complex oxide which is the catalyst component according to the present invention is an oxide containing iron,
Alternatively, since the oxide is formed in a form in which iron and an oxide containing titanium and / or zirconium are intimately mixed, the oxidation number cannot be accurately determined, but in consideration of general manganese oxide, It is known that the oxide of manganese changes to a lower oxide than the oxide fired at a low temperature when fired at a high temperature higher than 550 ° C. It has been demanded. Based on this, the oxidation number of manganese according to the present invention can be estimated. From this, the oxidation number of the oxide of manganese in the catalyst according to the present invention is calculated as x in terms of MnOx.
= 1.5 to 2.0 is considered effective, that is, manganese has an oxidation number of trivalent or tetravalent. Furthermore, in the form of MnOx, it is considered effective that x is in the range of 1.7 to 2.0, and it is considered particularly effective that the oxidation number of manganese is tetravalent. .

The manganese oxide and / or the composite oxide form various modifications, but the catalyst according to the present invention is not limited thereby.

In the present invention, at least one selected from the group consisting of iron, titanium and zirconium, or a precursor of an iron oxide and / or a composite oxide in the process of producing the catalyst of the present invention containing no manganese. For the precursor of the seed oxide and / or the complex oxide, it can be fired at a firing temperature higher than 500 ° C., which is a higher temperature, and further can be fired at a firing temperature higher than 550 ° C. In this case, the activity of the catalyst according to the present invention is slightly lowered, but the mechanical strength of the catalyst may be increased.
However, even in this case, it is effective that the firing temperature is 800 ° C. or lower. When the temperature exceeds 800 ° C., the specific surface area of the produced oxide decreases, so that the contact efficiency between the substance to be treated and the catalyst decreases, and the activity of the catalyst decreases.

Next, a method of treating wastewater using the catalyst for treating wastewater of the present invention will be described.

The treatment temperature of the catalytic wet oxidation treatment in the present invention is 140 ° C. or higher and lower than 370 ° C., preferably 1
The temperature is 50 ° C or higher and lower than 300 ° C, and more preferably 16
It is 0 ° C or higher and lower than 280 ° C. When the treatment temperature is 370 ° C or higher, the liquid phase of the wastewater cannot be maintained, and when the treatment temperature is 300 ° C or higher, a considerable pressurization condition is required to maintain the liquid phase. The cost is high in terms of costs and operating costs. When the treatment temperature is lower than 140 ° C, organic matter and inorganic COD
Purification of wastewater is often inadequate because the efficiency of treatment of components etc. decreases and purification of wastewater becomes incomplete, and organic substances are often not fully decomposed even at temperatures below 150 ° C. .

The type of oxygen-containing gas in the present invention is not particularly limited, and gases such as oxygen and ozone can be used, but air is preferably inexpensive and, depending on the case, these are appropriately used. It can also be used after diluting with an inert gas or the like. In addition to these gases, oxygen-containing exhaust gas generated from other plants can be used as appropriate.

The amount of the oxygen-containing gas used is appropriately selected depending on the concentration of the treated wastewater, but the amount of oxygen required for completely converting COD components in the wastewater to water, carbon dioxide gas, inorganic salts, ash, etc. It is 0.3 to 5 times, more preferably 1.0 to 3 times. When it exceeds 5 times, it becomes unnecessary supply of oxygen,
If it is less than 0.3 times, the amount of oxygen is not sufficient and the purification of waste water is incomplete. Further, the range of 0.3 to 1.0 times is not sufficient as the amount of oxygen necessary for completely converting COD components and the like in the waste water to water, carbon dioxide gas, inorganic salts, and other ash, but it is a normal wet oxidation treatment. Then the processing efficiency of COD is 10
Since it is less than 0%, for example, oxygen supplied at 1.0 times is not used 100% in the end and often remains in the exhaust gas after the treatment. Therefore, in such a case, the amount of oxygen supplied should be adjusted to 1.0 in accordance with the actual processing efficiency.
This is because even if the amount is reduced to less than double, if the oxygen excess state in which oxygen remains after the treatment is maintained, the treatment may not be hindered in some cases.

The amount of liquid treated in the treatment of wastewater using the catalyst according to the present invention is generally 0.
1 hr-1 to 10 hr-1, more preferably 0.5
hr-1 to 5 hr-1. When the space velocity exceeds 10 hr -1, the wastewater treatment efficiency decreases, and the space velocity becomes 0.1 h.
If it is less than r-1, the amount of wastewater to be treated is reduced and the equipment becomes too large.

The pH at the time of performing wet oxidation treatment of wastewater with the catalyst according to the present invention is not particularly limited and can be set appropriately. In particular, the catalyst has a peculiarity of being superior in alkali resistance as compared with the conventional catalyst, so that the p
It is convenient to treat those where H is alkaline. For example, it is preferably used at pH 6 or higher, and more preferably at pH 7.5 or higher. The same applies to the treatment liquid pH after the wet oxidation treatment and the liquid pH during the wet oxidation treatment, and it is preferable to use at a pH of 6 or more, more preferably pH.
It is preferably used at 7.5 or more.

Generally, stainless steel or the like is used as the material of the pipes and reactors used in the catalytic wet oxidation treatment, and there is a problem of corrosion of the pipes and the like in the acidic region. Therefore, from the viewpoint of preventing corrosion, it is preferable that the wastewater is adjusted to a pH in the alkaline range before being subjected to the reaction. Many conventional catalysts often have lower activity when the pH of the liquid is in the alkaline range than when they are acidic. The characteristics that the catalyst according to the present invention has excellent alkali resistance and high activity are also preferable from these requirements.

Since the catalyst according to the present invention has high durability and activity in alkaline as described above, it becomes possible to adjust the pH of waste water to a high alkaline range and improve the corrosion resistance in terms of the material of the device. You can
The problem of the corrosion resistance of the equipment materials is that halogen-containing compounds such as chlorine ions, bromine ions, and organic halogen compounds in conventional waste water; sulfur-containing compounds such as thiosulfate ions, sulfite ions, sulfides, and organic sulfur compounds; nitrate ions, It was especially problematic when containing a nitrogen-containing compound such as nitrite ion, ammonium ion, organic nitrogen compound,
The catalyst according to the present invention is also effective for wastewater containing these.

The upper limit of the pH when the waste water is subjected to the wet oxidation treatment with the catalyst according to the present invention is not particularly limited, but the pH of the treatment liquid after the wet oxidation treatment is preferably 12.
The following is effective, and more effectively pH
Is 10 or less. When the pH is higher than 12, the treatment efficiency may be lower than that when the pH of the treatment liquid is 10 or less. In addition, when the treatment liquid is discharged into a river or the like, it is necessary to adjust the pH to neutralize the alkali when the alkalinity is high, but when the treatment liquid has a high pH, the amount of acid used at this time increases. Also occurs. In addition, when materials such as stainless steel are used in the reaction tower, the pH
When is higher than 12, there is a problem such as alkali corrosion of the material.

Also, among the conventional catalysts, amine compounds,
Amide compounds, wastewater containing organic nitrogen compounds such as amino acid compounds, wastewater containing sulfur-containing compounds such as organic sulfur compounds and wastewater containing organic halogen compounds, there are some problems in durability especially, By using the catalyst according to the present invention, wastewater can be treated with good durability and high treatment efficiency.

In the present invention, when adjusting the pH of the wastewater, sodium hydroxide, potassium hydroxide, sodium carbonate or the like or an aqueous solution thereof may be added as appropriate, and the pH is not particularly limited. . If necessary, an acidic pH-adjusting agent such as sulfuric acid may be added, which is not particularly limited. In addition, the addition method in this case is not particularly limited, and in some cases it may be added in advance to a stock tank of waste water, or it may be continuously added using a feed pump to adjust the pH. it can.

Similarly, the pH of the treatment liquid after treating the wastewater with the catalyst according to the present invention is adjusted in the same manner as above so that the treatment liquid has a pH suitable for discharging or for carrying out the post-treatment. It is possible to add sodium hydroxide, potassium hydroxide, sodium carbonate, sulfuric acid or the like, or an aqueous solution thereof, and the like, but is not particularly limited, and the addition method is also not particularly limited. Absent.

In the present invention, it is possible to treat the wastewater by using a conventional method for purifying the wastewater before the practice of the present invention, and there is no particular limitation. For example, it is possible to carry out a purification treatment for removing heavy metals and calcium, magnesium, silicon, aluminum, phosphorus, etc. which are problematic for producing scales in the catalytic wet oxidation treatment. Specifically, activated carbon, an inorganic adsorbent Alternatively, it can be removed by an adsorption separation removal method using an organic polymer material, an electrodialysis method, or the like. Further, it is also possible to carry out a purification treatment for separating and removing solid matters and the like in the wastewater, and it is also possible to employ a purification treatment such as a non-catalytic wet oxidation treatment method for decomposing organic matters and inorganic COD components and the like.

Similarly, after the present invention is carried out, the treatment liquid according to the present invention can be treated by using a conventional wastewater purification method, and the present invention is not particularly limited. After carrying out the present invention, for example, even when biological treatment or chemical treatment is performed, harmful substances and the like are previously removed from the wastewater, and C
The OD component etc. are considerably reduced, and the remaining CO
Since the component D and the like are decomposed into substances that are very easily decomposed in biological treatment or chemical treatment, the burden on the biological treatment equipment or the chemical treatment equipment becomes very small.

Further, in the present invention, since the site is small and the apparatus is compact, the treatment equipment is compared with the conventional wastewater treatment equipment such as biological treatment equipment and combustion treatment equipment. Is small, the treatment process is simplified, and it is advantageous in terms of capital investment and running cost.

In the present invention, the catalyst can be appropriately washed and is not particularly limited by the washing method and the like. For example, it is carried out using water and an alkaline aqueous solution, but preferably an alkaline aqueous solution is used. Is effective. Although water alone can remove the scale components physically attached weakly to the catalyst, it is difficult to remove the scale components physically strongly adsorbed, the scale components chemically adsorbed, and the like. The catalyst according to the present invention does not deteriorate even in this washing.

The alkaline aqueous solution used as the detergent is not particularly limited, and various alkaline aqueous solutions such as sodium hydroxide aqueous solution, potassium hydroxide aqueous solution and sodium carbonate aqueous solution can be used. These detergents are used properly depending on the kind of the substance adhered on the catalyst to be washed, but an aqueous sodium hydroxide solution is generally preferable.

The concentration of this alkaline aqueous solution is, for example, in the case of using an aqueous sodium hydroxide solution, it is effective that the concentration of sodium hydroxide is 1 g / liter or more, and 10 g is more effective. / Liter or more. If the concentration of sodium hydroxide is less than 1 g / liter, the cleaning effect is significantly reduced. 10g
If it is less than 1 liter / liter, the amount of cleaning liquid will be large,
The treatment after washing becomes complicated and the treatment temperature must be relatively high in order to complete the washing treatment in a short time. Further, the concentration of sodium hydroxide is preferably less than 400 g / liter, more preferably 300 g.
/ Liter is the case. If the amount is 400 g / liter or more, the viscosity of the cleaning liquid increases, making it difficult to feed the cleaning liquid, and the corrosion resistance of the material of the apparatus may deteriorate when used at high temperatures.

The temperature at which the cleaning is performed using an alkaline cleaning solution is not particularly limited as long as it is a temperature of 50 ° C to 300 ° C, but preferably 130 ° C to 270.
℃. If the treatment temperature is low, the cleaning effect is small and the cleaning time is long. Therefore, the higher the temperature, the shorter the cleaning time and the better the cleaning power, but it is necessary to perform the cleaning at a temperature under the pressure at which the cleaning liquid holds the liquid phase. In addition, excessive high temperature conditions not only increase operating costs, but also may reduce the corrosion resistance of the equipment material.

The treatment pressure at the time of catalyst washing is appropriately selected depending on the correlation with the washing temperature, and is set under the pressure at which the washing liquid holds the liquid phase, and is not particularly limited.

The cleaning method in the present invention may be a continuous cleaning method in which the cleaning liquid is always flowed, or may be stored in a container filled with a catalyst and left standing for a certain period of time for cleaning and withdrawing at any time. It may be a batch-type cleaning method, and is not particularly limited.

The wastewater according to the present invention is generally used in chemical plant equipment, plating industry equipment, leather manufacturing equipment, metal industrial equipment, metal mining equipment, food manufacturing equipment, pharmaceutical manufacturing equipment, textile industrial equipment, paper pulp industrial equipment, Dyestuff industrial equipment, electronic industrial equipment, machinery industrial equipment, printing plate making equipment, glass manufacturing equipment, is intended for wastewater from photographic processing equipment, etc., preferably nitrogen-containing compounds in the wastewater, sulfur-containing compounds and It contains at least one compound selected from the group consisting of halogen-containing compounds. Furthermore,
When the nitrogen-containing compound is an organic nitrogen compound and the halogen-containing compound is an organic halogen compound, the effect of treating the wastewater in the present invention is better than before.

The nitrogen-containing compounds according to the present invention are inorganic nitrogen compounds such as ammonia and hydrazine, and organic nitrogen compounds. Furthermore, an organic nitrogen compound is an organic compound containing at least one nitrogen atom,
For example, dimethylformamide, pyridine, picoline,
Acetamide, aniline, glycine, alanine, phenylalanine, glutamic acid, lysine, aspartic acid,
Serine, methionine, histidine, ethylenediamine,
Examples include nitrogen atom-containing low molecular weight organic substances such as ethanolamine and triethanolamine, cationic or amphoteric surfactants such as dodecylamine, and nitrogen atom-containing polymers such as polyacrylic acid amide.

The sulfur-containing compound according to the present invention is an inorganic or organic compound containing at least one sulfur atom other than a sulfate group, such as dimethyl sulfoxide,
Dimethyl sulfone, methanesulfonic acid, thiophene, thiophene, p-toluenesulfonic acid, sulfobenzoic acid,
Thioacetic acid, low molecular weight organic compounds containing sulfur atoms such as naphthalene sulfonic acid, or anionic or amphoteric surfactants such as dodecylbenzene sulfonic acid, or sulfur atom-containing polymers such as polysulfonic acid, or thiosulfuric acid, Examples include sulfur atom-containing inorganic substances such as sulfurous acid and sodium sulfide.

The halogen-containing compound according to the present invention means an inorganic halogen compound such as sodium chloride and sodium bromate and an organic halogen compound. Further, the organic halogen compound is an organic compound containing at least one halogen atom, for example, methyl chloride, methyl bromide, ethyl chloride, ethyl bromide, dichloroethylene, tetrachloroethylene, 1,1,1-trichloroethane, Examples thereof include halogen atom-containing organic substances such as vinyl chloride, benzyl bromide, p-chlorophenol, trichlorofluoromethane, and dichlorofluoromethane.

The concentration of these compounds is not particularly limited, but in the case of an inorganic COD component and an organic substance, it is 10 mg / liter to 100 g / liter in waste water, preferably 100 mg / liter to 50 g / liter. When it is less than 10 mg / liter, it can be sufficiently treated without using the catalyst according to the present invention, and when it is more than 100 g / liter, the concentration is too high. Processing temperature for,
It is difficult to control various amounts of the oxygen-containing gas supplied. Further, in the case of inorganic salts and the like, when the concentration is high, the line is clogged due to the precipitation from these liquids. Therefore, the inorganic salt is preferably less than 200 g / liter.

The COD concentration of the wastewater treated in the present invention is not particularly limited, but it is effective when it is contained in the range of 1 g / liter to 200 g / liter, and more effective. 10g / l-100g
/ Liter. When the concentration of COD exceeds 200 g / liter, the heat of oxidation of COD becomes very large, making it difficult to control the treatment equipment. Even when the concentration of COD exceeds 100 g / liter, the heat of oxidation of COD is large, so that cooling is required. In many cases, equipment is provided, which increases cost. When the amount is less than 1 g / liter, almost all the amount of heat required to raise the temperature must be supplied by the heat supply device. Even when the amount is less than 10 g / liter, COD has a small heat of oxidation, and even if heat is recovered by using a heat exchange device as an auxiliary equipment, it is often difficult to operate the wet oxidation treatment device by this heat alone. Therefore, even in such a case, a separate heat supply device is often required, which is relatively disadvantageous in terms of energy consumption.

As the wet oxidation treatment apparatus filled with the catalyst used in the present invention, that is, a catalyst wet oxidation treatment apparatus, a commonly used one is used, and the treatment tower or the reaction tower is either a single tube type or a multi-tube type. Format,
Depending on the components contained in the wastewater, the amount thereof, etc., the single-pipe type and the multi-pipe type may be treated alone or in combination under conditions suitable for the treatment.

Further, according to the present invention, when an oxygen-containing gas and waste water are supplied to a reaction tower filled with a catalyst and the waste water is wet-oxidized under a pressure such that the waste water maintains a liquid phase, one reaction tower is used. There is also provided a method for treating wastewater, which comprises stacking and filling at least two kinds of catalysts having different catalyst compositions, and filling the catalyst according to the present invention on the upstream side with respect to the flow direction of the wastewater to perform wet oxidation treatment on the wastewater. .

Further, according to the present invention, when the oxygen-containing gas and the waste water are supplied to the reaction column filled with the catalyst and the waste water is subjected to the wet oxidation treatment under the pressure at which the waste water holds the liquid phase,
At least two kinds of catalysts having different catalyst compositions are packed in a plurality of reaction towers, respectively, and the catalyst according to the present invention is packed in a reaction tower on the upstream side in the flow direction of the waste water to perform wet oxidation treatment of the waste water. A method for treating wastewater is also provided.

Further, wastewater can be treated by combining these two methods.

At least two kinds of catalysts having different catalyst compositions packed in one reaction tower or a plurality of reaction towers are always packed with the catalyst according to the present invention, but the rest are according to the present invention having other compositions. It may be a catalyst or a conventionally known catalyst. Examples of conventionally known catalysts include, but are not limited to, the catalyst systems described in the section of the prior art of the present specification. Also preferably, ruthenium on the downstream side with respect to the flow direction of the wastewater,
There is also provided a method for treating wastewater, in which a catalyst containing at least one kind of metal of an element selected from the group consisting of rhodium, palladium, iridium, and platinum and / or a compound of the metal is installed and the wastewater is wet-oxidized. provide.

The reason for using a plurality of catalysts as described above is that, as described above, the treatment of wastewater containing an organic nitrogen compound, a sulfur-containing compound, an organic halogen compound, and the like, which many conventional catalysts have. That is, the problems of durability and processing efficiency are solved. That is, hardly decomposable organic nitrogen compounds, sulfur-containing compounds, organic halogen compounds, etc. are pretreated with the catalyst according to the present invention. For this reason, the rest of the treatment liquid is easily decomposable COD.
The components and the like remain and can be sufficiently treated with a conventionally known catalyst. As a result, the durability of the conventionally known catalyst can be improved, and the cost can be reduced. Then, pollutants such as COD components in the wastewater are subjected to oxidation and oxidative decomposition treatment with high treatment efficiency, and the wastewater is purified at a high level.

In this case, the volume ratio of the catalyst installed on the upstream side of the waste water to the volume ratio of the catalyst installed on the downstream side of the waste water is
It is preferably 1/10 to 10/1, and more effectively 1/5 to 5/1. Two or more different catalyst compositions or catalyst composition ratios when the upstream catalyst is less than 1/10 of the downstream catalyst and when the upstream catalyst is more than 10/1 of the downstream catalyst The effect of using one catalyst is small, and there is not much difference from the result of using one kind of catalyst. That is, it is meaningless to use a plurality of catalysts having different catalyst effects. In this case, producing a single catalyst is preferable to producing a plurality of catalysts because the production cost of the catalyst is lowered.

[0105]

EXAMPLES The catalyst preparation examples, catalyst molding examples and wastewater treatment examples according to specific examples of the present invention and preparation examples and wastewater treatment examples according to comparative examples will be described in detail below. The invention is not limited to this.

Preparation Example 1 An oxide containing manganese and iron and / or a composite oxide was prepared by the method described below.

Ferrous nitrate [Fe (N
O3) 3.9H2O] 9.10 kg was dissolved, and a manganese nitrate aqueous solution [Mn (NO3) 2] (MnO2 conversion 250
0.80 liter (g / liter) was added and mixed well. Ammonia water was gradually added dropwise with stirring while maintaining the temperature at 30 ° C., and the mixture was added until the pH reached 8, and then allowed to stand for 15 hours to form a precipitate (gel). The gel is filtered off, washed with water and then at 120 ° C for 10
Dried for hours. Then, it was fired at 500 ° C. for 3 hours in an air atmosphere.

The weight ratio of each component of the obtained powder was MnO2: Fe2O3 = 10: 90 by the fluorescent X-ray method. The specific surface area measured by the BET method was 51 m 2 / g. Further, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Preparation Example 2 Manganese and iron, an oxide containing titanium, and / or a composite oxide were prepared by the method described below. An aqueous solution of sulfuric acid having the following composition was used as the titanium source.

TiOSO4 250 g / liter (as TiO2) Total H2SO4 1,100 g / liter Water 100 liters ferric nitrate [Fe (NO3) 3.9H
2O] 7.08 kg was dissolved, and 0.80 liter of a manganese nitrate aqueous solution [Mn (NO3) 2] (250 g / liter in terms of MnO2) was added and mixed well. Ammonia water was gradually added dropwise with stirring while maintaining the temperature at 30 ° C., and the mixture was added until the pH reached 8, and then allowed to stand for 15 hours to form a precipitate (gel).
While maintaining the temperature of 30 ° C. again at the temperature of 30 ° C. while stirring the gel aqueous solution, 1.60 liters of a titanyl sulfate aqueous solution of the above composition was added, and ammonia water was gradually added dropwise.
The mixture was added until the pH reached 8, and then allowed to stand for 15 hours to form a precipitate (gel). This gel was separated by filtration, washed with water, and then dried at 120 ° C. for 10 hours. Then, it was fired at 500 ° C. for 3 hours in an air atmosphere.

The weight ratio of each component of the obtained powder was MnO2: Fe2O3: TiO2 = 10: 70: 2 by the fluorescent X-ray method.
It was 0. The specific surface area measured by the BET method was 65 m 2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Subsequently, the powder obtained here was used to mold a catalyst by the method described below.

(Molding Example 1) Water, the powder obtained in Preparation Example 2 and starch were mixed and kneaded well with a kneader. This kneaded product was molded into a pellet having an average particle size of 5 mm and an average length of 6 mm by a molding machine, and was fired at 450 ° C. for 3 hours in an air atmosphere. The specific surface area of the obtained catalyst was 65 m 2 / g as measured by the BET method.

Preparation Example 3 In 100 liters of water, 7.08 kg of ferric nitrate [Fe (NO3) 3.9H2O] and zirconium oxynitrate [ZrO (NO3) 2.2H2O].
87 kg was dissolved and manganese chloride aqueous solution [MnCl
2] (250 g / liter in terms of MnO2) 0.80 liter was added and mixed well. While maintaining this at a temperature of 30 ° C, gradually add ammonia water while stirring to adjust the pH.
No. 8 was added, and the mixture was allowed to stand for 15 hours to form a precipitate (gel). The gel is filtered off,
After washing with water, it was dried at 120 ° C. for 10 hours. Then, it was baked in an air atmosphere at 480 ° C. for 3 hours.

The weight ratio of each component of the obtained powder was MnO2: Fe2O3: ZrO2 = 10: 70: 2 by the fluorescent X-ray method.
It was 0. The specific surface area measured by the BET method was 60 m 2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Subsequently, using the powder obtained here, a catalyst was molded by the same method as described in Molding Example 1.

Preparation Example 4 In 100 liters of water, 7.28 kg of ferric nitrate [Fe (NO3) 3.9H2O] and zirconium oxynitrate [ZrO (NO3) 2.2H2O] 0.
52 kg is dissolved, and a manganese nitrate aqueous solution [Mn (NO
3) 2] (MnO2 conversion 250 g / liter) 0.32
Liter and 0.96 liter of titanyl sulfate aqueous solution were added and mixed well. While maintaining this at a temperature of 30 ° C., ammonia water was gradually added dropwise while stirring to adjust the pH to 8
The mixture was added to the above until it was left to stand, and then allowed to stand for 15 hours to form a precipitate (gel). This gel was separated by filtration, washed with water, and then dried at 120 ° C. for 10 hours. Then, it was baked in an air atmosphere at 480 ° C. for 3 hours.

The weight ratio of each component of the obtained powder was MnO2: Fe2O3: TiO2: ZrO2 = 4: by fluorescent X-ray method.
It was 72:12:12. The specific surface area measured by the BET method was 65 m 2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Subsequently, using the powder obtained here, a catalyst was molded by the same method as described in Molding Example 1.

Preparation Example 5 8.90 kg of ferric nitrate [Fe (NO3) 3.9H2O] was dissolved in 100 liters of water, and 0.80 liter of an aqueous titanyl sulfate sulfate solution was added and mixed well. Ammonia water was gradually added dropwise with stirring while maintaining the temperature at 30 ° C., and the mixture was added until the pH reached 8, and then allowed to stand for 15 hours to form a precipitate (gel). After filtering this gel and washing with water,
0.040 kg of active manganese dioxide powder was added, kneaded well with a kneader, and dried at 120 ° C. for 10 hours. Then, it was baked at 450 ° C. for 4 hours in an air atmosphere.

The weight ratio of each component of the obtained powder is MnO2: Fe2O3: TiO2 = 2: 88: 10 by the fluorescent X-ray method.
Met. When the specific surface area was measured by the BET method, it was 6
It was 3 m2 / g. Furthermore, when the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, a peak of a diffraction line corresponding to β-MnO 2 was obtained. However, the peak intensity of this diffraction line was much smaller than the peak of the β-MnO 2 diffraction line prepared by the following method and similarly measured by the X-ray diffraction method, and the intensity was about ⅕.

Those used for comparison by the X-ray diffraction method were 0.040 kg of the active manganese dioxide powder calcined at 450 ° C. for 4 hours, and ferric nitrate and sulfuric acid prepared by the same method as described above. A precipitate (gel) prepared from a titanyl sulfuric acid aqueous solution was calcined at 450 ° C. for 4 hours, and 1.96 kg of iron and titanium oxide and / or complex oxide powder was simply mixed well.

Subsequently, using the powder obtained here, a catalyst was molded by the same method as described in Molding Example 1.

Preparation Example 6 To 100 liters of water, 2.00 liters of an aqueous titanyl sulfate-sulfuric acid solution was added and mixed well. While maintaining this at a temperature of 30 ° C., ammonia water was gradually added dropwise while stirring, and added until the pH reached 8,
Further, it was left as it was and left to stand for 15 hours to form a precipitate (gel). The gel obtained was filtered and washed with water.
Separately, iron hydroxide (FeOOH) 1.
52 kg and manganese nitrate aqueous solution [Mn (NO3) 2] (M
0.56 liter (250 g / liter in terms of nO2) was added and kneaded well. To the resulting kneaded product, the gel prepared above was filtered and washed with water, kneaded well with a kneader, and dried at 120 ° C. for 10 hours. Then, it was baked at 450 ° C. for 4 hours in an air atmosphere.

The weight ratio of each component of the obtained powder is MnO2: Fe2O3: TiO2 = 7: 68: 25 by the fluorescent X-ray method.
Met. The specific surface area measured by the BET method was 70 m2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Subsequently, using the powder obtained here, a catalyst was molded by the same method as described in Molding Example 1.

Preparation Example 7 To 100 liters of water was added 1.60 liters of a titanyl sulfate aqueous solution of sulfuric acid, and they were mixed well. While maintaining this at a temperature of 30 ° C., ammonia water was gradually added dropwise while stirring, and added until the pH reached 8,
Further, it was left as it was and left to stand for 15 hours to form a precipitate (gel). The gel obtained was filtered and washed with water.
Separately, iron hydroxide (FeOOH) 1.
34 kg and 0.53 kg of manganese carbonate [MnCO3] were added and kneaded well. To the resulting kneaded product, the gel prepared above was filtered and washed with water, kneaded well with a kneader, and dried at 120 ° C. for 10 hours. Then, it was baked at 350 ° C. for 4 hours in an air atmosphere.

The weight ratio of each component of the obtained powder is MnO2: Fe2O3: TiO2 = 20: 60: 2 by the fluorescent X-ray method.
It was 0. The specific surface area measured by the BET method was 92 m 2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Subsequently, a catalyst was molded by the same method as described in Molding Example 1 except that the powder obtained here was used at a firing temperature of 330 ° C.

(Preparation Example 8) 9.00 kg of ferric nitrate [Fe (NO3) 3.9H2O] was dissolved in 100 liters of water, and 0.80 liter of an aqueous titanyl sulfate sulfate solution was added and mixed well. Ammonia water was gradually added dropwise with stirring while maintaining the temperature at 30 ° C., and the mixture was added until the pH reached 8, and then allowed to stand for 15 hours to form a precipitate (gel). After filtering this gel and washing with water,
It was dried at 120 ° C. for 10 hours. Then, in an air atmosphere, 70
It was baked at 0 ° C. for 5 hours.

The weight ratio of each component of the obtained powder was 90:10 by the fluorescent X-ray method.

Subsequently, using the powder obtained here, a powder having the above composition was molded by the same method as described in Molding Example 1.

1.98 kg of the obtained pellet-shaped molded body
Using a manganese nitrate aqueous solution [Mn (NO3) 2] (MnO
It was impregnated with 0.40 liters (50 g / liter in terms of 2) and dried at 120 ° C. for 10 hours. Then, it was baked in an air atmosphere at 480 ° C. for 3 hours.

The weight ratio of each component of the obtained catalyst was MnO2: Fe2O3: TiO2 = 1: 89: 10 by the fluorescent X-ray method.
Met. The specific surface area measured by the BET method was 34 m 2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

(Preparation Example 9) 7.08 kg of ferric nitrate [Fe (NO3) 3.9H2O] was dissolved in 100 liters of water to prepare a manganese nitrate aqueous solution [Mn (NO3) 2] (MnO2).
(Converted 250 g / liter) 0.80 liter, palladium nitrate aqueous solution (Pd conversion 5 g / liter) 1.20
L was added and mixed well. While maintaining this at a temperature of 30 ° C., ammonia water was gradually added dropwise while stirring, and the pH was adjusted to 8 and then left as it is for 1
After standing for 5 hours, a precipitate (gel) was formed. While maintaining the temperature of 30 ° C. at the temperature of this gel again, 1.60 liters of a titanyl sulfate aqueous solution of the above composition was added while stirring, and ammonia water was gradually added dropwise until pH reached 8. It was left as it was and left to stand for 15 hours to form a precipitate (gel). This gel was separated by filtration, washed with water, and then dried at 120 ° C. for 10 hours. Then, it was fired at 500 ° C. for 3 hours in an air atmosphere.

The weight ratio of each component of the obtained powder was MnO2: Fe2O3: TiO2: Pd = 10: 7 by the fluorescent X-ray method.
It was 0: 20: 0.3. The specific surface area measured by the BET method was 68 m2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Subsequently, using the powder obtained here, a catalyst was molded by the same method as described in Molding Example 1.

(Preparation Example 10) 7.08 kg of ferric nitrate [Fe (NO3) 3.9H2O] and zirconium oxynitrate [ZrO (NO3) 2.2H2O] in 100 liters of water.
Dissolve 0.52 kg into a manganese nitrate aqueous solution [Mn
(NO3) 2] (MnO2 conversion 250g / liter)
0.80 liter, ruthenium nitrate aqueous solution (Ru conversion
4.0 g (5 g / l) was added and mixed well. While maintaining this at a temperature of 30 ° C., ammonia water was gradually added dropwise while stirring, and added until the pH reached 8,
Further, it was left as it was and left to stand for 15 hours to form a precipitate (gel). The gel is filtered off, washed with water and then at 120 ° C for 1
It was dried for 0 hours. Then, it was baked at 450 ° C. for 3 hours in an air atmosphere.

The weight ratio of each component of the obtained powder was MnO2: Fe2O3: ZrO2: Ru = 10: 7 by the fluorescent X-ray method.
It was 0: 20: 1.0. The specific surface area measured by the BET method was 65 m 2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Subsequently, the powder obtained here was used to mold a catalyst by the same method as described in Molding Example 1 except that the firing temperature was 400 ° C.

(Preparation Example 11) 8.60 kg of ferric nitrate [Fe (NO3) 3.9H2O] was dissolved in 100 liters of water to prepare an aqueous solution of manganese nitrate [Mn (NO3) 2] (MnO).
0.40 liter of 2 conversion (250 g / liter) and 0.80 liter of platinum nitrate aqueous solution (Pt conversion 5 g / liter) were added and mixed well. While maintaining this at a temperature of 30 ° C., ammonia water was gradually added dropwise while stirring, and p
H was added until it reached 8, and the mixture was allowed to stand for 15 hours to form a precipitate (gel). 0.80 liter of an aqueous solution of titanyl sulfate having the above composition was added with stirring while maintaining the temperature of this gel solution at 30 ° C. again.
Further, ammonia water was gradually added dropwise, and the pH was adjusted to 8. Then, the mixture was allowed to stand for 15 hours to form a precipitate (gel). The gel is filtered off, washed with water and
It was dried at 20 ° C. for 10 hours. Then 350 in an air atmosphere
Calcination was performed for 4 hours.

The weight ratio of each component of the obtained powder is MnO2: Fe2O3: TiO2: Pt = 5: 8 by the fluorescent X-ray method.
It was 5: 10: 0.2. The specific surface area measured by the BET method was 80 m2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Subsequently, a catalyst was molded by the same method as described in Molding Example 1 except that the powder obtained here was used at a firing temperature of 330 ° C.

Preparation Example 12 To 100 liters of water, 1.60 liters of titanyl sulfate aqueous solution was added and mixed well. Ammonia water was gradually added dropwise with stirring while maintaining the temperature at 30 ° C., and the mixture was added until the pH reached 8, and then allowed to stand for 15 hours to form a precipitate (gel). The gel obtained was filtered and washed with water. Next, iron hydroxide (FeOOH) was added to the kneader.
1.68 kg and the gel obtained above were added and kneaded well. The obtained kneaded product was calcined in an air atmosphere at 600 ° C. for 3 hours and further pulverized to obtain a powder.

Subsequently, using the powder obtained here, a powder having the above composition was molded by the same method as described in Molding Example 1 except that the firing temperature was 500 ° C.

The obtained pellet-shaped molded product had a manganese nitrate aqueous solution [Mn (NO3) 2] (50 g / MnO2 conversion).
1.00 liter) and 5.00 liters of iridium chloride aqueous solution (2 g / liter in terms of Ir) were impregnated and dried at 120 ° C. for 10 hours. Then, it was baked at 400 ° C. for 3 hours in an air atmosphere.

The weight ratio of each component of the obtained powder was MnO2: Fe2O3: TiO2: Ir = 5: 7 by the fluorescent X-ray method.
It was 5: 20: 0.5. The specific surface area measured by the BET method was 45 m 2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

(Preparation Example 13) 9.10 kg of ferric nitrate [Fe (NO3) 3.9H2O] was dissolved in 100 liters of water to prepare an aqueous manganese nitrate solution [Mn (NO3) 2] (MnO2).
2 conversion 250 g / liter) 0.80 liter, rhodium nitrate aqueous solution (Rh conversion 5 g / liter) 2.00
L was added and mixed well. While maintaining this at a temperature of 30 ° C., ammonia water was gradually added dropwise while stirring, and the pH was adjusted to 8 and then left as it is for 1
After standing for 5 hours, a precipitate (gel) was formed. This gel was separated by filtration, washed with water, and then dried at 120 ° C. for 10 hours. Then, it was baked at 300 ° C. for 5 hours in an air atmosphere.

The weight ratio of each component of the obtained powder was MnO2: Fe2O3: Rh = 10: 90: 0.
It was 5. The specific surface area measured by the BET method was 60 m 2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

Preparation Example 14 The gel obtained by the same method as in Preparation Example 2 was filtered off, washed with water and dried at 120 ° C. for 10 hours.
Further, it was baked at 600 ° C. for 3 hours in an air atmosphere.

The weight ratio of each component of the obtained powder is 9.2 in terms of Mn2O3: Fe2O3: TiO2 by the fluorescent X-ray method.
It was 70.6: 20.2. Also, the specific surface area is BET
It was 43 m <2> / g when measured by the method. Furthermore, X
The crystal structure of the manganese oxide and / or the composite oxide was measured by a line diffraction method, but no diffraction line of the manganese oxide was obtained.

Subsequently, using the powder obtained here, a catalyst was molded by the same method as described in Molding Example 1.

Preparation Example 15 Powder firing temperature is 600 ° C.
The powder obtained by the same method as in Preparation Example 5 except for the above was molded by the same method as that described in Molding Example 1.

The weight ratio of each component of the obtained powder was 1.8: calculated as Mn2O3: Fe2O3: TiO2 by the fluorescent X-ray method.
It was 88.2: 10. The specific surface area measured by the BET method was 38 m 2 / g. Further, when the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffractometry, a diffraction line peak corresponding to α-Mn 2 O 3 was obtained. However, the peak intensity of this diffraction line was much smaller than the peak of the diffraction line of α-Mn 2 O 3 measured by the X-ray diffraction method for the sample prepared by the following method, and the intensity was about 1/6. . The sample used for comparison was 0.982 kg of powder obtained by drying a gel containing iron and titanium prepared by the same method as in Preparation Example 5 at 120 ° C. for 10 hours and calcining at 600 ° C. for 3 hours in an air atmosphere. And 600 mg of the activated manganese dioxide powder used in Preparation Example 5 separately.
A mixture of 0.018 kg of powder calcined at 3 ° C. for 3 hours was simply mixed well.

Preparation Example 16 Fe2 obtained in Preparation Example 8
O3: TiO2 = 90:10 pelletized molded body 1.98k
Using g, the following solution was impregnated and calcined to prepare a catalyst. The solution used for impregnation was an aqueous solution of manganese nitrate [Mn.
(NO3) 2] (MnO2 conversion 50 g / liter)
A mixed solution of 40 liters and 0.45 liters of an aqueous potassium nitrate solution [KNO3] (K conversion: 2.5 g / liter) was used. After impregnation, it was dried at 120 ° C. for 10 hours. Then, it was baked in an air atmosphere at 300 ° C. for 3 hours.

The weight ratio of each component of the obtained catalyst was MnO2: Fe2O3: TiO2: K = 1: 89: by fluorescent X-ray method.
It was 10: 0.06. The specific surface area measured by the BET method was 34 m 2 / g. Furthermore, the crystal structure of the manganese oxide and / or the composite oxide was measured by the X-ray diffraction method, but no diffraction line of the manganese oxide was obtained.

(Comparative Preparation Example 1) Powder was obtained in the same manner as in Preparation Example 1 except that the aqueous solution of manganese nitrate was not used in Preparation Example 1.

The composition of the obtained powder was F by the fluorescent X-ray method.
e2 O3 = 100%.

(Comparative Preparation Example 2) A powder was obtained in the same manner as in Preparation Example 2 except that the aqueous solution of manganese nitrate was not used in Preparation Example 2, and was molded by the same method as that described in Molding Example 1. Got the body

The weight ratio of each component of the obtained powder was Fe2O3: TiO2 = 78: 22 by the fluorescent X-ray method.

(Comparative Preparation Example 3) An aqueous solution of palladium nitrate (Pd conversion: 5 g / liter) 1.2 was added to 100 liters of water.
0 liter and 8.00 liter of titanyl sulfate aqueous solution were added and mixed well. Ammonia water was gradually added dropwise with stirring while maintaining the temperature at 30 ° C., and the mixture was added until the pH reached 8, and then allowed to stand for 15 hours to form a precipitate (gel). This gel was separated by filtration, washed with water, and then dried at 120 ° C. for 10 hours. Then, it was fired at 500 ° C. for 3 hours in an air atmosphere.

The weight ratio of each component of the obtained powder was TiO2: Pd = 100: 0.3 by the fluorescent X-ray method.

Subsequently, using the powder obtained here, a molded body was obtained by the same method as described in Molding Example 1.

Comparative Preparation Example 4 To 100 liters of water, 1.20 liters of platinum nitrate aqueous solution (5 g / liter in terms of Pt) and 8.00 liters of titanyl sulfate aqueous solution were added and mixed well. Ammonia water was gradually added dropwise with stirring while maintaining the temperature at 30 ° C., and the mixture was added until the pH reached 8, and then allowed to stand for 15 hours to form a precipitate (gel). After filtering this gel and washing with water,
It was dried at 120 ° C. for 10 hours. Then 40 in an air atmosphere
It was baked at 0 ° C. for 5 hours.

The weight ratio of each component of the obtained powder was TiO2: Pt = 100: 0.3 by the fluorescent X-ray method.

Subsequently, a molded body was obtained by the same method as described in Molding Example 1 except that the powder obtained here was used at a firing temperature of 380 ° C.

(Comparative Preparation Example 5) Preparation Example 1 except that the aqueous solution of manganese nitrate was not used in Preparation Example 10.
A powder was obtained in the same manner as in No. 0, and a molded body was obtained by the same method as described in Molding Example 1 except that the firing temperature was 400 ° C.

The weight ratio of each component of the obtained powder was determined by the fluorescent X-ray method to be Fe2O3: ZrO2: Ru = 78: 22: 1.
It was 0.

(Processing Example 1) A titanium autoclave having an internal volume of 1 liter was used, and 30 g of the catalyst prepared in Preparation Example 1 and 250 g of waste water were charged into the autoclave.
Furthermore, 25 kg / cm2G of air was added. And 2
The temperature was raised to 50 ° C., and treatment was performed at 82 kg / cm 2 G for 3 hours. After cooling, the liquid was extracted, and the COD (Cr) concentration of the undiluted wastewater before treatment and the treated liquid was measured to determine the treatment efficiency. As the wastewater used for this treatment, a treatment liquid of the wastewater which was once subjected to the wet oxidation treatment was used in the same manner as above under the non-catalyst condition without using a catalyst as the pretreatment. The properties of this wastewater are: COD (Cr) concentration 17g / liter, pH
It was 9.5.

The obtained results show that the COD (Cr) concentration is 0.7 g.
/ Liter, the COD (Cr) treatment efficiency was 96%, and the pH was 8.2.

(Comparative Treatment Example 1) Using the same method as in Treatment Example 1 and the same wastewater, 30 g of the powder prepared in Comparative Preparation Example 1 was treated.

The obtained results show that the COD (Cr) concentration is 14 g /
The pH was 9.3 at a COD (Cr) treatment efficiency of 18%.

(Processing Example 2) Using the wet oxidation treatment apparatus shown in FIG. 1, 1 liter of the catalyst prepared in Preparation Example 2 was filled in this wet oxidation reaction tower and the treatment was carried out under wet oxidation treatment conditions.
It was carried out continuously for 00 hours. Then, COD (Cr) and pH of the treated water obtained after 500 hours were measured, and triethanolamine was analyzed by a gas chromatographic analysis method.
The detailed experimental methods and results are described below.

A detailed method of treatment under a wet oxidation condition using a catalyst is as follows. Waste water sent from the waste water supply line 7 is 80 k at a flow rate of 2 liters / hr by the waste water supply pump 2.
The pressure was fed up to g / cm 2 G. On the other hand, the air supplied from the oxygen-containing gas supply line 8 is supplied to the compressor 3
After pressurizing with, the mixture was mixed with the waste water at a ratio of O2 / COD (Cr) (oxygen content in air / chemical oxygen demand) = 2.0. This gas-liquid mixture is passed through the gas-liquid mixture supply line 9,
It is introduced into the catalyst-filled wet oxidation reaction tower 1 from below, heated by an electric heater 4 and subjected to catalytic wet oxidation at a treatment temperature of 250 ° C., and the water to be treated is cooled in a cooler 5 through a treated water line 10. Then, it was flowed to the gas-liquid separator 6. The space velocity of the wastewater in this catalyst layer was 2 hr-1. In the gas-liquid separator 6, the liquid level controller (LC) detects the liquid level to operate the liquid level control valve 12 to maintain a constant liquid level, and the pressure controller (PC) detects the pressure. Then, the pressure control valve 14 is operated to maintain a constant pressure, and the treated water is discharged from the treated water discharge line 13.

The properties of the wastewater subjected to the treatment are COD (Cr)
Was 37 g / l, the pH was 8.7, and triethanolamine was 5.0 g / l.

The results of the treated water obtained after 500 hours are as follows:
COD (Cr) was 1.2 g / liter, COD (Cr) treatment efficiency was 97%, and pH was 7.7. In addition, triethanolamine was not detected.

After that, the treatment of the wastewater was stopped and the catalyst packed in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the wastewater.

(Processing Example 3) The procedure of Example 3 was repeated except that the catalyst obtained in Preparation Example 3 was used instead of the catalyst used in Processing Example 2.
The processing was performed under the same conditions as those described in Processing Example 2.

The results of the treated water obtained after 500 hours are as follows:
COD (Cr) was 1.8 g / liter, COD (Cr) treatment efficiency was 95%, and pH was 7.8. In addition, triethanolamine was not detected.

After that, the treatment of the wastewater was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the wastewater.

(Treatment Example 4) The catalyst obtained in Preparation Example 9 was used in place of the catalyst used in Treatment Example 2, except that
The processing was performed under the same conditions as those described in Processing Example 2.

The results of the treated water obtained after 500 hours are as follows:
COD (Cr) was 1.1 g / liter, COD (Cr) treatment efficiency was 97%, and pH was 7.7. In addition, triethanolamine was not detected.

After that, the treatment of the wastewater was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the wastewater.

Comparative Treatment Example 2 Treatment was carried out under the same conditions as described in Treatment Example 2 except that the catalyst used in Treatment Example 2 was replaced by the molded body obtained in Comparative Preparation Example 2. .

The result of treated water obtained immediately after the start was CO
D (Cr) is 19 g / liter, COD (Cr) treatment efficiency is 49%
The pH was 8.2. When triethanolamine was measured, it was detected to be 1.9 g / liter.

Comparative Treatment Example 3 Treatment was carried out under the same conditions as those described in Treatment Example 2 except that the molded body obtained in Comparative Preparation Example 3 was used instead of the catalyst used in Treatment Example 2. .

The result of the treated water obtained immediately after the start was CO
D (Cr) is 3.1 g / liter, COD (Cr) treatment efficiency is 92
% And pH was 7.8. When triethanolamine was measured, it was not detected.

However, the results of the treated water obtained after 500 hours were as follows: COD (Cr) was 8.3 g / liter, COD (Cr)
The treatment efficiency was 78% and the pH was 8.0. When triethanolamine was measured, 0.3 g / liter was detected.

After that, the treatment of the waste water was stopped, and the molded body filled in the wet oxidation reaction column was taken out. As a result of analyzing the change in the composition of the molded product extracted by the fluorescent X-ray method, the content of palladium in the molded product was slightly decreased, especially in the molded product at the inlet of the reaction tower, as compared with that before the wastewater treatment. . The weight ratio of each component of the inlet compact is TiO2: P
It was 100: 0.12.

Treatment Example 5 Using the wet oxidation treatment apparatus shown in FIG. 1, 1 liter of the catalyst prepared in Preparation Example 4 was filled in this wet oxidation reaction tower and treated under wet oxidation treatment conditions.
It was carried out continuously for 00 hours. Then, the COD (Cr) concentration and pH of the treated water obtained after 500 hours were measured, and ethylenediaminetetraacetic acid was analyzed by liquid chromatography analysis.

The properties of the wastewater subjected to the treatment are COD (Cr)
Was 26 g / liter, pH was 12.8, and ethylenediaminetetraacetic acid was 2.1 g / liter.

The treatment conditions for waste water are the treatment temperature 270.
℃, treatment pressure 90 kg / cm 2 G, O 2 / COD (Cr) (oxygen content in air / chemical oxygen demand) = 1.2, space velocity of wastewater is 1 hr −1, the same method as in Treatment Example 2 Was processed by.

The results of the treated water obtained after 500 hours are as follows:
COD (Cr) was 0.32 g / liter, COD (Cr) treatment efficiency was 99%, and pH was 9.4. In addition, ethylenediaminetetraacetic acid was not detected.

After that, the treatment of the waste water was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the waste water.

(Processing Example 6) The catalyst obtained in Preparation Example 6 was used in place of the catalyst used in Processing Example 5, except that
Processing was performed under the same conditions as those described in Processing Example 5.

The results of the treated water obtained after 500 hours are as follows:
COD (Cr) was 0.37 g / liter, COD (Cr) treatment efficiency was 99%, and pH was 9.4. In addition, ethylenediaminetetraacetic acid was not detected.

After that, the treatment of the waste water was stopped and the catalyst filled in the wet oxidation reaction column was extracted, but no particular change was observed before the treatment of the waste water.

(Processing Example 7) The catalyst obtained in Preparation Example 7 was used in place of the catalyst used in Processing Example 5, except that
Processing was performed under the same conditions as those described in Processing Example 5.

The results of the treated water obtained after 500 hours are as follows:
COD (Cr) was 0.21 g / liter, COD (Cr) treatment efficiency was 99%, and pH was 9.4. In addition, ethylenediaminetetraacetic acid was not detected.

After that, the treatment of the wastewater was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the wastewater.

Comparative Treatment Example 4 Treatment was carried out under the same conditions as described in Treatment Example 5, except that the catalyst used in Treatment Example 5 was replaced by the molded body obtained in Comparative Preparation Example 2. .

The result of the treated water obtained immediately after the start was CO
D (Cr) is 16g / liter, COD (Cr) treatment efficiency is 38%
The pH was 10.4. In addition, 0.74 g / liter of ethylenediaminetetraacetic acid was detected.

Treatment Example 8 Using the wet oxidation treatment apparatus shown in FIG. 1, 1 liter of the catalyst prepared in Preparation Example 5 was filled in this wet oxidation reaction tower and the treatment was carried out under the wet oxidation treatment conditions.
It was carried out continuously for 00 hours. Then, the COD (Cr) concentration and pH of the treated water obtained after 500 hours were measured, and dimethylformamide was analyzed by a gas chromatographic analysis method.

The properties of the wastewater subjected to the treatment are COD (Cr)
Was 46 g / liter, pH was 10.2, and dimethylformamide was 7.8 g / liter.

The treatment conditions for wastewater are the treatment temperature of 200
℃, treatment pressure 40 kg / cm 2 G, O 2 / COD (Cr) (oxygen content in air / chemical oxygen demand) = 1.2, space velocity of wastewater is 1 hr −1, the same method as in Treatment Example 2 Was processed by.

The treated water results obtained after 500 hours are:
COD (Cr) was 3.7 g / liter, COD (Cr) treatment efficiency was 92%, and pH was 8.7. In addition, dimethylformamide was not detected.

After that, the treatment of the waste water was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the waste water.

(Processing Example 9) The procedure of Example 9 was repeated except that the catalyst obtained in Preparation Example 8 was used in place of the catalyst used in Processing Example 8.
Processing was performed under the same conditions as those described in Processing Example 8.

The results of the treated water obtained after 500 hours are as follows:
COD (Cr) was 4.2 g / liter, COD (Cr) treatment efficiency was 91%, and pH was 8.7. In addition, dimethylformamide was not detected.

After that, the treatment of the wastewater was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the wastewater.

Comparative Treatment Example 5 Treatment was carried out under the same conditions as described in Treatment Example 8 except that the molded body obtained in Comparative Preparation Example 2 was used in place of the catalyst used in Treatment Example 8. .

The result of the treated water obtained immediately after the start was CO
D (Cr) is 20 g / liter, COD (Cr) treatment efficiency is 57%
The pH was 9.3. When dimethylformamide was measured, 2.1 g / liter was detected.

Treatment Example 10 Using the wet oxidation treatment apparatus shown in FIG. 1, 1 liter of the catalyst prepared in Preparation Example 6 was filled in the wet oxidation reaction tower 1 and the treatment was carried out for 100 hours under the wet oxidation treatment condition. It went continuously. The COD (Cr) concentration and pH of the treatment liquid obtained after 100 hours were measured, and p-chlorophenol was analyzed by gas chromatographic analysis.

The properties of the wastewater used for the treatment are COD (Cr)
The concentration was 24 g / liter, pH was 9.1, and p-chlorophenol was 0.9 g / liter.

The treatment conditions for wastewater are the treatment temperature of 250.
℃, treatment pressure 75 kg / cm 2 G, O 2 / COD (Cr) (oxygen content in air / chemical oxygen demand) = 1.2, space velocity of wastewater is 1 hr −1, the same method as in Treatment Example 2 Was processed by.

The results of the treatment solutions obtained after 100 hours are as follows:
The COD (Cr) concentration was 0.4 g / liter, the COD (Cr) treatment efficiency was 98%, and the pH was 8.4. In addition, p-chlorophenol was not detected.

After that, the treatment of the waste water was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the waste water.

Comparative Treatment Example 6 Treatment was carried out under the same conditions as described in Treatment Example 11 except that the catalyst used in Treatment Example 10 was replaced by the molded body obtained in Comparative Preparation Example 2. .

The result of the treatment liquid obtained immediately after the start was CO
The D (Cr) concentration was 7.5 g / liter, the COD (Cr) treatment efficiency was 69%, and the pH was 8.7. Further, 0.35 g / l of p-chlorophenol was detected.

Treatment Example 11 Using the wet oxidation treatment apparatus shown in FIG. 1, 1 liter of the catalyst prepared in Preparation Example 2 was filled in the wet oxidation reaction tower 1 and the treatment was carried out for 100 hours under the wet oxidation treatment conditions. It went continuously. Then, the COD (Cr) concentration and pH of the treatment liquid obtained after 100 hours were measured, and dimethyl sulfoxide (hereinafter also referred to as DMSO) was analyzed by a gas chromatographic analysis method.

The properties of the wastewater used for the treatment are COD (Cr)
The concentration was 33 g / liter, pH was 13.1, and DMSO was 4.5 g / liter.

The treatment conditions for wastewater are the treatment temperature 220
℃, treatment pressure 50 kg / cm 2 G, O 2 / COD (Cr) (oxygen content in air / chemical oxygen demand) = 2.0, space velocity of wastewater is 1 hr −1, the same method as in Treatment Example 2 Was processed by.

The results of the treatment solutions obtained after 100 hours are as follows:
The COD (Cr) concentration was 1.0 g / liter, the COD (Cr) treatment efficiency was 97%, and the pH was 8.1. Also, DMSO was not detected.

After that, the treatment of the waste water was stopped and the catalyst filled in the wet oxidation reaction column was extracted, but no particular change was observed before the treatment of the waste water.

Comparative Treatment Example 7 Treatment was carried out under the same conditions as described in Treatment Example 12 except that the catalyst used in Treatment Example 11 was replaced by the molded body obtained in Comparative Preparation Example 2. .

The result of the treatment liquid obtained immediately after the start was CO
D (Cr) concentration is 12 g / liter, COD (Cr) treatment efficiency is 6
At 4%, the pH was 8.6. DMSO is 0.8
g / l was detected.

Comparative Treatment Example 8 Treatment was carried out under the same conditions as described in Treatment Example 11 except that the molded body obtained in Comparative Preparation Example 4 was used in place of the catalyst used in Treatment Example 11. .

The result of the treatment liquid obtained immediately after the start was CO
The D (Cr) concentration was 2.3 g / liter, the COD (Cr) treatment efficiency was 93%, and the pH was 8.3. Also, DMSO was not detected.

However, the results of the treatment liquid obtained after 100 hours showed that the COD (Cr) concentration was 6.3 g / liter and the COD
The (Cr) treatment efficiency was 81%, and the pH was 8.5. Also D
MSO was detected at 0.11 g / liter.

After that, the treatment of the waste water was stopped, and the molded body filled in the wet oxidation reaction tower was taken out. As a result of analyzing the change in composition of the molded product extracted by the fluorescent X-ray method, it was found that the content of platinum in the molded product was slightly decreased, especially in the molded product at the inlet of the reaction tower, as compared with that before the wastewater treatment. . The weight ratio of each component of the inlet compact was 100: 0.16 in terms of TiO2: Pt.

Treatment Example 12 Using the wet oxidation treatment apparatus shown in FIG. 1, 1 liter of the catalyst prepared in Preparation Example 4 was filled in the wet oxidation reaction tower 1 and the treatment was carried out under the wet oxidation treatment condition for 500 hours. It went continuously. Then, the COD (Cr) concentration and pH of the treatment liquid obtained after 500 hours were measured, and sulfide ion was analyzed by a detector tube and thiosulfate ion was analyzed by anion chromatography analysis method.

The property of the wastewater used for the treatment is COD (Cr)
Concentration 10.5 g / liter, pH 13.3, sulfide ion 3.7 g / liter, thiosulfate ion 0.3
It was 0 g / liter.

The treatment conditions for waste water are the treatment temperature 160
℃, treatment pressure 9 kg / cm 2 G, O 2 / COD (Cr) (oxygen content in air / chemical oxygen demand) = 2.5, space velocity of wastewater is 1 hr −1, the same method as in Treatment Example 2 Was processed by.

The results of the treatment solutions obtained after 100 hours are as follows:
The COD (Cr) concentration was 2.8 g / liter, the COD (Cr) treatment efficiency was 73%, and the pH was 8.2. Neither sulfide ion nor thiosulfate ion was detected.

After that, the treatment of the waste water was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the waste water.

Comparative Treatment Example 9 Treatment was carried out under the same conditions as described in Treatment Example 12 except that the catalyst used in Treatment Example 12 was replaced by the molded body obtained in Comparative Preparation Example 2. .

The result of the treatment liquid obtained immediately after the start was CO
The D (Cr) concentration was 3.9 g / liter, the COD (Cr) treatment efficiency was 63%, and the pH was 8.7. Further, sulfide ion was not detected, but thiosulfate ion was detected at 0.35 g / liter.

Treatment Example 13 Using the wet oxidation treatment apparatus shown in FIG. 1, 1 liter of the catalyst prepared in Preparation Example 10 was filled in the wet oxidation reaction tower 1 and the treatment was carried out for 100 hours under the wet oxidation treatment conditions. It went continuously. Then, the COD (Cr) concentration and pH of the treatment liquid obtained after 100 hours were measured, and aniline was analyzed by a gas chromatographic analysis method.

The property of the wastewater used for the treatment is COD (Cr)
The concentration was 28 g / liter, pH was 12.9, and aniline was 1.8 g / liter.

The treatment conditions for waste water are the treatment temperature 250
℃, treatment pressure 75 kg / cm 2 G, O 2 / COD (Cr) (oxygen content in air / chemical oxygen demand) = 1.2, space velocity of wastewater is 1 hr −1, the same method as in Treatment Example 2 Was processed by.

The results of the treatment solutions obtained after 100 hours are as follows:
The COD (Cr) concentration was 0.17 g / liter, the COD (Cr) treatment efficiency was 99%, and the pH was 8.6. In addition, aniline was not detected.

After that, the treatment of the wastewater was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the wastewater.

Treatment Example 14 Treatment was carried out under the same conditions as those described in Treatment Example 13 except that the catalyst obtained in Preparation Example 11 was used in place of the catalyst used in Treatment Example 13.

The result of the treated water obtained after 100 hours is as follows:
COD (Cr) was 0.62 g / liter, COD (Cr) treatment efficiency was 98%, and pH was 8.6. In addition, aniline was not detected.

After that, the treatment of the waste water was stopped and the catalyst packed in the wet oxidation reaction column was extracted, but no particular change was observed before the treatment of the waste water.

(Treatment Example 15) The treatment was carried out under the same conditions as those described in Treatment Example 13 except that the catalyst obtained in Preparation Example 12 was used in place of the catalyst used in Treatment Example 13.

The results of the treated water obtained after 100 hours are as follows:
COD (Cr) was 1.4 g / liter, COD (Cr) treatment efficiency was 95%, and pH was 8.8. In addition, aniline was not detected.

After that, the treatment of the waste water was stopped and the catalyst packed in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the waste water.

(Comparative Treatment Example 10) Treatment was carried out under the same conditions as those described in Treatment Example 13 except that the molded body obtained in Comparative Preparation Example 2 was used in place of the catalyst used in Treatment Example 13. .

The result of the treatment liquid obtained immediately after the start was CO
The D (Cr) concentration was 13.5 g / liter, the COD (Cr) treatment efficiency was 52%, and the pH was 10.7. Further, 0.51 g / l of aniline was detected.

Comparative Treatment Example 11 Treatment was carried out under the same conditions as described in Treatment Example 13 except that the catalyst used in Treatment Example 13 was replaced by the molded body obtained in Comparative Preparation Example 5. .

The result of the treatment liquid obtained immediately after the start was CO
The D (Cr) concentration was 2.5 g / liter, the COD (Cr) treatment efficiency was 91%, and the pH was 8.9. In addition, aniline was not detected.

However, the results of the treatment liquid obtained after 100 hours showed that the COD (Cr) concentration was 4.8 g / liter and COD
The (Cr) treatment efficiency was 83%, and the pH was 9.4. Further, 0.15 g / l of aniline was detected.

Treatment Example 16 Treatment was carried out under the same conditions as described in Treatment Example 1 except that the catalyst obtained in Preparation Example 13 was used in place of the catalyst used in Treatment Example 1.

The results of the treated water obtained were that COD (Cr) was 0.4 g / liter, COD (Cr) treatment efficiency was 98%, and pH was
Was 7.6.

After that, the catalyst was taken out, but no particular change was observed before the wastewater treatment.

Treatment Example 17 Treatment was carried out under the same conditions as those described in Treatment Example 2 except that the catalyst obtained in Preparation Example 14 was used instead of the catalyst used in Treatment Example 2.

The result of the treated water obtained immediately after the start was CO
D (Cr) is 2.2 g / liter, COD (Cr) treatment efficiency is 93
% And pH was 7.8. In addition, triethanolamine was not detected.

However, the result of the treated water obtained after 250 hours was that COD (Cr) was 4.0 g / liter and COD (Cr)
The treatment efficiency was 89% and the pH was 7.9. No triethanolamine was detected.

Treatment Example 18 Treatment was carried out under the same conditions as those described in Treatment Example 8 except that the catalyst obtained in Preparation Example 15 was used instead of the catalyst used in Treatment Example 8.

The result of the treated water obtained immediately after the start was CO
D (Cr) is 6.0 g / liter, COD (Cr) treatment efficiency is 87
The pH was 8.9 in%. In addition, no dilylformamide was detected.

However, the result of the treated water obtained after 250 hours was that COD (Cr) was 8.3 g / liter and COD (Cr)
The treatment efficiency was 82% and the pH was 9.2. Diltylformamide was not detected.

Treatment Example 19 Using the wet oxidation treatment apparatus shown in FIG. 1, 1 liter of the catalyst prepared in Preparation Example 7 was filled in the wet oxidation reaction tower and the treatment was continued for 500 hours under the wet oxidation treatment conditions. I went. Then, the ammonium ion concentration, nitrate ion concentration, and nitrite ion concentration of the treated water obtained after 500 hours were measured by the ion chromatographic analysis method, the total nitrogen concentration was measured by the total nitrogen analysis method, and the pH was measured.

The property of the wastewater subjected to the treatment is that the pH is 1
0.2, ammonium ion is 3.5 g / liter,
Nitrite ion and nitrate ion were not contained.
The total nitrogen concentration was 2.7 g / liter.

The treatment conditions for wastewater are the treatment temperature of 250.
℃, treatment pressure 75kg / cm2G, space velocity of wastewater is 1
It was hr-1. The amount of air supplied was such that 3 mol of molecular oxygen was supplied with respect to the supply of 1 mol of ammonium ions. Then, the same process as in Process Example 2 was performed.

The results of the treated water obtained after 500 hours are as follows:
The pH was 7.4, the nitrate ion concentration was 0.31 g / liter, and ammonium ion and nitrite ion were not detected. The total nitrogen concentration was 0.09 g / liter, and the total nitrogen treatment efficiency was 97%.

After that, the treatment of the waste water was stopped and the catalyst packed in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the waste water.

Treatment Example 20 Treatment was carried out under the same conditions as those described in Treatment Example 8 except that the catalyst obtained in Preparation Example 16 was used in place of the catalyst used in Treatment Example 8.

The results of the treated water obtained after 500 hours are as follows:
COD (Cr) was 4.0 g / liter, COD (Cr) treatment efficiency was 91%, and pH was 8.7. In addition, dimethylformamide was not detected.

After that, the treatment of the waste water was stopped and the catalyst filled in the wet oxidation reaction column was taken out, but no particular change was observed before the treatment of the waste water.

[Brief description of drawings]

FIG. 1 is one of embodiments of a processing apparatus according to the present invention.

[Explanation of symbols]

 1. Wet oxidation reaction tower 2. Wastewater supply pump 3. Compressor 4. Electric heater 5. Cooler 6. Gas-liquid separator 7. Waste water supply line 8. Oxygen-containing gas supply line 9. Gas-liquid mixture supply line 10. Treated water line 11. Cooling water line 12. Liquid level control valve 13. Treated water discharge line 14. Pressure control valve 15. Gas discharge line

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B01J 23/745 23/889 23/89 ZAB M C02F 1/74 ZAB 101 B01J 23/84 311 M

Claims (13)

[Claims] 1. A manganese oxide and an iron oxide and /
Alternatively, a wastewater treatment catalyst containing a complex oxide of manganese and iron. 2. The wastewater treatment catalyst according to claim 1, further comprising a respective oxide and / or complex oxide of titanium and / or zirconium. 3. The catalyst for treating wastewater according to claim 2, wherein titanium and / or zirconium and intimately mixed manganese and / or iron. 4. The wastewater treatment catalyst according to claim 1, further comprising at least one metal of an element selected from the group consisting of ruthenium, rhodium, palladium, iridium, and platinum and / or a compound of the metal. 5. The catalyst according to claim 1, wherein the manganese oxide and / or the composite oxide is 0.05 to 50% by weight in terms of MnO2, and the iron oxide and / or the composite oxide is Fe2O3. As a conversion 99.95-
The wastewater treatment catalyst according to claim 1, which is 50% by weight. 6. The catalyst according to claim 2 or 3, wherein the manganese oxide and / or the composite oxide is Mn.
O2 conversion is 0.05 to 50% by weight, and iron oxide and / or composite oxide is 95% as Fe2O3 conversion.
% To 30% by weight, and the oxide and / or composite oxide of titanium and / or zirconium is 5 to 70% by weight in terms of TiO2 and ZrO2 (at least one selected from the group consisting of iron, titanium and zirconium). The metal oxide and / or the composite oxide is F
The total amount is 99.95 to 50% by weight in terms of e2O3, TiO2 and ZrO2.) The wastewater treatment catalyst according to claim 2 or 3. 7. A metal of an element selected from the group consisting of ruthenium, rhodium, palladium, iridium, and platinum, and / or a metal thereof, based on 100 parts by weight of the catalyst according to claim 1, 2, 3, 5 or 6. 7. The wastewater treatment catalyst according to claim 1, comprising at least one metal compound in an amount ranging from 0.05 to 10 parts by weight. 8. The manganese oxide and / or the composite oxide is x = 1.5 to 2.0 in terms of MnOx.
The wastewater treatment catalyst according to claim 1, which is in the range of 1. 9. The BET specific surface area of the catalyst is 5 to 200 m.
The catalyst for treating wastewater according to claims 1 to 7, which is 2 / g. 10. At least a step of heat-treating a manganese oxide precursor and an iron oxide precursor and / or a manganese-iron composite oxide precursor at 300 ° C. or higher in an oxidizing atmosphere is employed. The method for producing the catalyst for treating wastewater according to claim 1, 3, 5 or 6. 11. The method according to claim 2, 3 or 6, wherein at least the step of heat-treating the titanium and / or zirconium oxide and / or the composite oxide precursor in an oxidizing atmosphere at 300 ° C. or higher is employed. The method for producing a catalyst for treating wastewater of. 12. A wet oxidation treatment of wastewater with an oxygen-containing gas in the presence of the catalyst according to any one of claims 1 to 11 at a treatment temperature of 140 ° C. or higher and lower than 370 ° C. and a pressure at which the wastewater maintains a liquid phase. Wastewater treatment method. 13. The method for treating wastewater according to claim 12, wherein the wastewater contains at least one of a nitrogen-containing compound, a sulfur-containing compound and a halogen-containing compound.