CN1306943A - Wastewater treatment method and catalyst washing regeneration method - Google Patents

Abstract

The present invention relates to a method for treating waste water, which is characterized by comprising (1) wet oxidation treatment of waste water containing at least one nitrogen-containing compound, organic substance and inorganic substance in the presence of a supported catalyst while maintaining a temperature of 100 ℃ or higher and a pressure of a liquid phase of at least a part of the waste water, in the presence of oxygen of a theoretical oxygen amount or more necessary for decomposing the nitrogen-containing compound and/or organic substance and/or inorganic substance in the waste water into nitrogen and/or carbon dioxide and water, and (2) circulating and mixing at least a part of a high-temperature liquid phase obtained by gas-liquid separation after the wet oxidation treatment with the waste water before the wet oxidation treatment.

Description

Wastewater treatment method and catalyst washing regeneration method

The present invention relates to a method for treating waste water (hereinafter simply referred to as waste water) containing at least one nitrogen-containing compound, organic substances and inorganic substances.

In addition, the present invention also relates to a method for washing and regenerating the catalyst used in the wet oxidation treatment of waste water. According to the catalyst cleaning and regeneration method of the present invention, metal components adhering to heat exchangers, gas-liquid separators, coolers, various piping, etc. in wastewater wet oxidation equipment can be simultaneously washed and removed.

Wet oxidation treatment methods for wastewater containing at least one nitrogen-containing compound, organic substances, and inorganic substances (hereinafter collectively referred to as "contaminated components") are known.

For example, Japanese Patent Publication No. 59-29317 filed by the applicant discloses a method for treating wastewater by wet oxidation in the presence of a supported catalyst to decompose ammonia, organic substances and inorganic substances in the wastewater.

As illustrated by the results shown in the examples, this method generally works best for wastewater treatment. However, for this method, when the concentration of dirty components in the waste water is high (for example, when the TOD value is more than 65000mg/l), due to the use of a large amount of air (oxygen) and the treatment under high temperature and high pressure conditions, in heat exchangers, heating A large amount of water in the reactor and reaction tower is evaporated and transferred to the gas phase. Therefore, in order to deal with the temperature drop caused by the latent heat of evaporation, it is necessary to increase the heat transfer area of the heat exchanger or heat it externally with an external heater. In addition, when the concentration of dirty components in the wastewater is high, or when the metal components in the wastewater adhere to the surface of the catalyst to reduce the activity, the treatment cannot be performed well.

Moreover, the prior art related to the wet oxidation treatment method is, for example, JP 53-20663, JP 54-42851, JP 55-152591, JP 62-132589, JP 3- No. 777691, Special Kaiping No. 4-104898.

In the wet oxidation method of these wastewaters, metal oxide carriers such as silica, alumina, titania, and zirconia, etc., which are loaded in various shapes such as spherical, granular, cylindrical, fragmented, and honeycomb, are usually used. In the state of supports such as composite metal oxide supports and activated carbon supports containing at least one of these metal oxides, use is made of iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these At least one of water-insoluble or hardly water-soluble compounds of metals. Since such supported catalysts (hereinafter referred to as wastewater oxidation catalysts) are used in large quantities when treating wastewater, it is necessary to regenerate and reuse the catalyst whose activity decreases with the passage of treatment time. The present inventors found that when the wastewater oxidation catalyst was subjected to two-step treatment in advance, that is, when acidic aqueous solution was used for pickling treatment and alkaline aqueous solution was used for liquid-phase reduction treatment or gas-phase reduction treatment, the activity of the catalyst was significantly restored (refer to Patent Publication 3-66018 Publication No., hereinafter referred to as the "prior application method").

This prior application method can produce an excellent catalyst regeneration effect, but since two steps of pickling treatment and reduction treatment must be carried out, in terms of practicality, it is expected to use a simpler treatment operation to achieve the same excellent effect.

Therefore, the main object of the present invention is to provide a new technology by which the wet oxidation of waste water containing at least one nitrogen-containing compound, organic substances and inorganic substances can be carried out even with relatively large amounts of air (oxygen). In the case of processing under high temperature and high pressure conditions, there is no need to increase the heat transfer area of the heat exchanger or use a heater to heat externally, and it can maintain a good liquid phase state and continue the reaction.

In addition, an object of the present invention is to provide a new technology capable of effectively and economically treating wastewater with a high concentration of fouling components by suppressing the attachment of metal components to the catalyst surface.

Furthermore, the main object of the present invention is to provide a novel wastewater treatment catalyst regeneration method capable of exhibiting a high catalyst regeneration effect through simple treatment operations.

Fig. 1 is a flowchart showing an embodiment of the present invention.

Fig. 2 is a flowchart showing another embodiment of the present invention.

The invention provides the following wastewater treatment method and catalyst washing regeneration method,

1. A waste water treatment method (hereinafter referred to as "the first treatment method") is characterized in that it comprises the following two steps:

(1) maintain a temperature above 100°C and at least a part of the waste water maintain the pressure of the liquid phase, and decompose nitrogen-containing compounds and/or organic substances and/or inorganic substances in the waste water into nitrogen and/or in the presence of a supported catalyst In the presence of oxygen above the theoretical oxygen amount necessary for carbon dioxide and water, wet oxidation treatment of wastewater containing at least one nitrogen-containing compound, organic substances and inorganic substances;

(2) At least a part of the high-temperature liquid phase obtained by gas-liquid separation after the wet oxidation treatment is circulated and mixed with the wastewater before the wet oxidation treatment.

2. The wastewater treatment method as described in 1, the catalyst active component in step (1) is selected from iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and water-insoluble or even at least one of the poorly soluble compounds.

3. The wastewater treatment method as described in 1, the linear velocity of the liquid in the tower in the step (1) (the amount of liquid entering the tower/the cross-sectional area of the tower) is 0.1-1.0 cm/sec.

4. The wastewater treatment method described in 1, the oxygen source in step (1) is at least one of air, oxygen-enriched air, high-purity oxygen, ozone and H ₂ O ₂ .

5. The waste water treatment method described in 1, the circulating volume of the high-temperature liquid phase in step (2) is 0.1 to 15 times that of the waste water.

6. Waste water treatment method (hereinafter referred to as " the second treatment method "), is characterized in that comprising following five steps:

(1) maintain a temperature above 100°C and at least a part of the waste water maintain the pressure of the liquid phase, and decompose nitrogen-containing compounds and/or organic substances and/or inorganic substances in the waste water into nitrogen and/or in the presence of a supported catalyst Or in the presence of high-purity oxygen-containing gas (oxygen concentration of 80% or more) above the theoretical oxygen amount necessary for carbon dioxide and water, wet oxidation treatment of wastewater containing at least one nitrogen-containing compound, organic substances and inorganic substances,

(2) At least a part of the high-temperature liquid phase obtained by the first gas-liquid separation after the wet oxidation treatment is mixed with the waste water before the wet oxidation treatment,

(3) After heat exchange is performed between the high-temperature gas-liquid phase obtained by the first gas-liquid separation and the waste water before the wet oxidation treatment, the gas-liquid phase is cooled to perform the second gas-liquid separation,

(4) carry out biological treatment to the liquid phase obtained by gas-liquid separation for the second time, and

(5) The excess sludge generated in the biological treatment is mixed with the above-mentioned waste water circulation.

7. The waste water treatment method as described in 6, in the step (1), the oxygen concentration in the gas containing high-purity oxygen is 80% or more.

8. The wastewater treatment method as described in 6, the catalyst active component in step (1) is selected from iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and water-insoluble or even at least one of the poorly soluble compounds.

9. The wastewater treatment method as described in 6, the liquid linear velocity in the tower in step (1) (the amount of liquid entering the tower/the cross-sectional area of the tower) is 0.1-1.0 cm/sec.

10. The wastewater treatment method described in 6, the oxygen source in step (1) is at least one of oxygen-enriched air, high-purity oxygen, ozone and H ₂ O ₂ .

11. The wastewater treatment method as described in 6, the circulating volume of the high-temperature liquid phase in step (2) is 0.1 to 15 times that of the wastewater.

12. The wastewater treatment method as described in 6, the biological treatment method in step (4) is an activated sludge treatment method and/or a biological denitrification method.

13. Catalyst washing regeneration method, it is characterized in that at least one in the water-insoluble or even insoluble compound of iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals is used as catalyst activity The method of washing and regenerating a supported catalyst for the wet oxidation of waste water of components comprises the following steps: using an acidic aqueous solution as a washing liquid, and for 1 m ³ /hr of the washing liquid, passing air at a ratio of 10 Nm ³ /hr or more, and at a temperature above normal temperature Contact the catalyst with the wash solution.

14. Catalyst washing regeneration method, it is characterized in that at least one in the water-insoluble or even insoluble compound of iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals is used as catalyst activity The method of washing and regenerating the supported catalyst for the wet oxidation of waste water of components includes the following steps: using an alkaline aqueous solution as the washing liquid, and for 1 m ³ /hr of the washing liquid, passing air at a ratio of 10 Nm ³ /hr or more, at a temperature above normal temperature contact the catalyst with the wash solution.

15. Catalyst washing regeneration method, it is characterized in that at least one in the water-insoluble or even insoluble compound of iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals is used as catalyst activity The method of washing and regenerating the supported catalyst for the wet oxidation of waste water of components comprises the following steps: (1) using an acidic aqueous solution as the washing liquid, and for the washing liquid 1m ³ /hr, air is passed in at a ratio of 10Nm ³ /hr or more, and the temperature is above normal temperature (2) Use an alkaline aqueous solution as the washing liquid, and for the washing liquid 1m ³ /hr, pass air at a ratio of 10Nm ³ /hr or more, and make the catalyst at a temperature above normal temperature contact with washing liquid.

16. Catalyst washing regeneration method, it is characterized in that at least one in the water-insoluble or even insoluble compound of iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals is used as catalyst activity The waste water wet oxidation method for cleaning and regenerating a supported catalyst for components comprises the following steps: (1) using an alkaline aqueous solution as a washing solution, and for 1 m ³ /hr of the washing solution, feeding air at a rate of more than 10 Nm ³ /hr, at normal temperature The catalyst is contacted with the washing liquid at a temperature above; (2) Use an acidic aqueous solution as the washing liquid, and for the washing liquid 1m ³ /hr, pass air in a ratio of 10Nm ³ /hr or more, and make the catalyst at a temperature above normal temperature contact with washing liquid.

17. A catalyst washing regeneration method in which the catalyst washing waste liquid produced in at least one of the methods 13-16 is subjected to wet oxidation treatment together with waste water.

18. For the catalyst washing and regeneration method described in 17, the catalyst washing liquid is subjected to coagulation and precipitation treatment, and after the metal components in the liquid are removed, wet oxidation treatment is performed together with the waste water. Ⅰ. Inventions involving wastewater treatment methods

Wastewater to be treated in the present invention is not particularly limited as long as it contains at least one of nitrogen-containing compounds, organic substances, and inorganic substances.

Nitrogen-containing compounds contained in waste water include, for example, NH ₄ -N (referring to nitrogen in the form of ammonium, hereinafter the same), NO ₂ -N, NO ₃ -N, organic nitrogen (including amines), inorganic nitrogen (including CN class, SCN class), etc.

Examples of organic substances contained in wastewater include organic substances (phenols, alcohols, carboxylic acids, etc.), organic chlorine compounds (trichloroethylene, tetrachloroethylene, dioxins, etc.), suspended substances (derived from Organic solid waste, sludge generated in various biological treatment steps, kitchen waste, municipal waste, biomass, etc.).

Inorganic substances contained in waste water are, for example, generally inorganic substances (such as S ₂ O ₃ ²⁻ , SO ₃ ²⁻ , SCN ⁻ , CN ^—, etc.).

In addition, the wastewater to be treated in the present invention includes, for example, wastewater containing one of the above-mentioned nitrogen-containing compounds, organic substances, and inorganic substances alone, and wastewater containing two or more of these substances simultaneously.

Such waste water is, for example, coal gas liquid produced by coke oven equipment for coal treatment, coal gasification equipment, coal liquefaction equipment, etc., waste water produced with coal gas generation in these equipment, waste water produced by wet desulfurization towers and wet decyanation towers , photographic wastewater, printing wastewater, pesticide wastewater, dyeing wastewater, semiconductor manufacturing factory wastewater, petrochemical factory wastewater, petroleum refining factory wastewater, pharmaceutical factory wastewater, paper mill wastewater, chemical factory wastewater, life containing kitchen waste, paper, plastic, etc. Wastewater, waste water from excrement and thermal decomposition of municipal waste, sludge from industrial wastewater biological treatment (anaerobic treatment, aerobic treatment), sewage sludge, waste water from oily sewage sludge, Wastewater containing organic chlorine compounds, various cyanide-containing waste liquids discharged from the electroplating industry, cyanide liquids used for surface treatment such as steel nitrocarburization treatment, liquid carbon immersion treatment, chemical conversion treatment, etc., cyanide waste discharged during these surface treatment processes liquid etc. For example, the above-mentioned cyanide-containing wastewater sometimes also contains various organic and inorganic substances (organic acids such as formic acid and acetic acid, etc.), ammonia and other nitrogen-containing compounds (if there is no special requirement below, all the compounds containing cyanide and ammonia include Nitrogen compounds are collectively referred to as "nitrogen-containing compounds"), organochlorine compounds such as trichlorethylene, etc.

The present invention is also useful for the treatment of waste water or sludge containing one or two or more metal components such as Mg, Al, Si, P, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, etc. .

The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a flowchart showing an embodiment of a first processing method.

FIG. 2 is a flowchart showing an embodiment of a second processing method.

In the first treatment method, the wastewater is pumped from the raw water tank to a specified pressure, mixed with oxygen-containing gas boosted by a compressor, and then heated by a heat exchanger (abbreviated as "heat exchange" in Figure 1). After reaching the specified temperature, it is supplied to the reaction tower.

In the second treatment method, the waste water is pumped from the raw water tank to a specified pressure, mixed with a gas containing high-purity oxygen boosted by a compressor, and then heated by a heat exchanger (referred to as "heat exchange" in Figure 2 for short). ”) After heating to the specified temperature, it is supplied to the reaction tower.

The catalyst supported by the carrier is filled in the reaction tower.

Catalyst active components are, for example, iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten as well as water-insoluble or even poorly soluble compounds of these metals. More specifically, such compounds are, for example, oxides (cobalt oxide, iron oxide, etc.), chlorides (ruthenium dichloride, platinum dichloride, etc.), sulfides (ruthenium sulfide, rhodium sulfide, etc.), and the like. These metals and their compounds may be used alone, or two or more of them may be used simultaneously, or they may be mixed with a metal as a third component (such as La, Ce, Te, etc.) to form a composite catalyst. These catalytically active components can be used in a state of being supported on known metal oxide supports and metal supports according to conventional methods.

The metal oxide carrier and metal carrier are not particularly limited, and those used as known catalyst carriers can be used. The metal oxide carrier is, for example, alumina, silica, zirconia, titania, composite metal oxides containing these metal oxides (alumina-silica, alumina-silica-zirconia, titania- zirconia, etc.), a metal oxide carrier mainly composed of these metal oxides or composite metal oxides, and the like, and the metal carrier is, for example, iron, aluminum, or the like. Among these supports, zirconia, titania, and titania-zirconia, which are excellent in durability, are more preferable.

The shape of the supported catalyst is also not particularly limited, such as spherical, granular, cylindrical, chipped, powdered, honeycomb, and the like. When filling such a supported catalyst, in the case of a fixed bed, the volume of the reaction tower is preferably such that the space velocity of the liquid becomes 0.5 to 10 hr ^-1 , more preferably 1 to 5 hr ^-1 . When the supported catalyst is spherical, granular, cylindrical, chipped, powdery, etc., the size of the supported catalyst used on the fixed bed is usually 3 to 50 mm, more preferably 5 to 25 mm. In addition, when the catalyst is supported on a honeycomb carrier and used, the honeycomb structure may have openings in any shape such as quadrangular, hexagonal, or circular. The area per unit volume, aperture ratio, etc. are not particularly limited, but those having an area per unit volume of 200 to 800 m ² /m ³ and an aperture ratio of 40 to 80% are generally used. The material of the honeycomb structure is, for example, the same metal oxides and metals as above, more preferably zirconia, titania and titania-zirconia which are excellent in durability.

The loading amount of the catalyst active component to the carrier is usually 0.05 to 25% by weight, more preferably 0.3 to 3% by weight.

In the heat exchanger, the high-temperature gas-liquid phase obtained by the gas-liquid separator described below is circulated to recover heat. In addition, when the specified reaction temperature cannot be maintained or must be raised to the specified temperature during the reaction in winter, etc., a heater (not shown) can also be used to heat, or a steam generator (not shown) can be used to supply the reaction temperature. tower steam. In addition, in order to make the temperature in the reaction tower reach the specified temperature during commissioning, it is also possible to directly pass steam into the reaction tower to raise the temperature, or to install a heater (not shown) between the heat exchanger and the reaction tower to raise the temperature.

The temperature in the reaction tower is 100°C or higher, more preferably 150°C or higher. The higher the temperature during the reaction, the higher the decomposition and removal rate of the dirty components. In addition, the residence time of the wastewater in the reaction tower is also shortened. The degree of reaction, operation cost, construction cost, etc. determine the reaction temperature.

The pressure during the reaction is preferably higher than the pressure at which the treated wastewater can maintain the liquid phase at the reaction temperature. Here, "the pressure at which the liquid phase can be maintained" refers to a high-concentration oxygen-containing gas with an oxygen concentration of 80% or more in the embodiment of FIG. Under the condition of feeding amount, in reaching equilibrium liquid (waste water) amount, water vapor amount and gas amount (the gas amount in the tower except water vapor), water vapor amount is below 60% (more preferably below 50%) , the pressure of the liquid phase can be maintained substantially in the reaction tower.

In addition, in the second treatment method, since the biological treatment of the treated water is carried out after the wet oxidation treatment, the reaction pressure is significantly increased, and ultra-high oxidation treatment is not required. It can be changed according to the type of wastewater to be treated, the concentration of dirty components, etc. For example, wet oxidation treatment can be performed at a relatively low pressure of 10 to 20 kg/cm ² .

In the first treatment method, the amount of oxygen supplied to the reaction tower is more than the theoretical oxygen amount necessary for the decomposition of nitrogen-containing compounds, organic substances and inorganic substances into harmless products, more preferably 1 to 3 times the theoretical oxygen amount , particularly preferably 1.05 to 1.2 times the theoretical oxygen amount. As the oxygen source, air, oxygen-enriched air (oxygen-enriched air obtained by using a selective oxygen permeable membrane, an air-oxygen mixture, oxygen-enriched air obtained by treating air with a PSA device, etc.), oxygen, and Substances that can generate oxygen (O ₃ , H ₂ O ₂ , etc.) under wastewater treatment conditions.

In the second treatment method, the amount of oxygen supplied to the reaction tower is above the theoretical oxygen amount necessary for the decomposition of nitrogen-containing compounds, organic substances and inorganic substances into harmless products, more preferably 1.05 to 3 times the theoretical oxygen amount , particularly preferably 1.1 to 1.2 times the theoretical oxygen amount. As an oxygen source, it is possible to use a gas with a high oxygen concentration of more than 80% with an oxygen concentration, such as oxygen-enriched air (the oxygen-enriched air obtained by using a selective oxygen permeable membrane, air-oxygen mixture, and treated with a PSA device) Oxygen-enriched air obtained from air, etc.), high-purity oxygen, and substances that can produce high-concentration oxygen under wastewater treatment conditions (O ₃ , H ₂ O _{2 ,} etc.).

In the first and second treatment methods, oxygen-containing waste gas containing one or two or more impurities such as hydrogen cyanide, hydrogen sulfide, ammonia, sulfur oxides, and nitrogen oxides can also be used as an oxygen source. substances, hydrocarbons, etc. According to the present invention, impurities in these oxygen sources can also be decomposed together with the components to be treated in the waste water.

In addition, in the present invention, "theoretical oxygen content" means that nitrogen-containing compounds, organic substances, and inorganic substances (components to be treated) in wastewater are decomposed into harmless products (N ₂ , H ₂ O, and CO ₂ ). of oxygen. The theoretical oxygen amount can be easily obtained by analyzing the treated components in the wastewater as the treatment object and calculating the oxygen amount necessary for its decomposition. In terms of practicality, based on experience and experiments, several parameters can be used to find a relational expression that can approximate and calculate the theoretical oxygen amount with high precision. Such a relational expression is described in Japanese Patent Publication No. 58-27999, for example.

The treated liquid obtained from the reaction tower is separated into a gas phase and a liquid phase by the first gas-liquid separator. A part of the gas phase and liquid phase obtained after separation is used as the waste water heating source in the heat exchanger as described above, then transported to the cooler, and then transported to the second gas-liquid separator, separated into gas phase (exhaust gas) and Liquid phase (processed water).

In the present invention, at least a part of the high-temperature and high-pressure liquid phase obtained by the first gas-liquid separator is circulated back to the reaction tower through a liquid circulation pipeline and a circulation pump (this circulation operation is called "thermal recirculation") and mixed with waste water . The circulation amount of the liquid can be appropriately determined according to the properties of the waste water (the type and concentration of the component to be treated, etc.), the degree of activity reduction of the catalyst filled in the reactor, etc., and is usually 0.1 to 15 times the amount of waste water, more preferably 1 to 10 times. times. Since a fixed bed is formed in the reaction tower and the catalyst is washed simultaneously, the liquid linear velocity in the tower is usually 0.1-1.0 cm/sec, more preferably 0.2-0.9 cm/sec.

The liquid phase and gas phase other than the above-mentioned circulating liquid are separated into exhaust gas and treated water in the second gas-liquid separator after passing through the heat exchanger and being cooled by the cooler in the first gas-liquid separator.

The treated water obtained from the second gas-liquid separator can also be biologically treated by conventional methods (activated sludge treatment method, biological denitrification method, etc.) according to the required water quality standards. The excess sludge produced by this biological treatment method can be subjected to wet oxidation treatment by the method of the present invention.

For example, when NH ₄ -N remains in the treated water, the treated water is biologically treated by nitrification reaction by nitrifying bacteria under aerobic conditions and denitrification reaction by denitrifying bacteria under anaerobic conditions as follows. (1) (2)

In addition, when (NO ₂ +NO ₃ )-N remains in the treated water, NO ₂ can undergo nitrification and denitrification reactions to generate NO ₃ .

Since this biological treatment method is a known technology, it is not limited in the present invention, and it is usually carried out under the conditions of pH 7.5-8 and temperature 30°C.

In addition, the excess sludge produced by the above biological treatment method can be recycled to the raw water tank, and treated together with the waste water by the wet oxidation treatment method of the present invention.

In addition, the regeneration treatment liquid of the reaction tower filled catalyst used in the present invention can be treated by coagulation and sedimentation to remove the metal components in the liquid if necessary, and then the method of the present invention can also be used to carry out wet oxidation treatment together with the waste water. The regeneration of the catalyst is not particularly limited. For example, it can be regenerated by washing treatment using a gas-liquid mixed phase of an acidic aqueous solution and air and/or a gas-liquid mixed phase of an alkaline aqueous solution and air. Acidic aqueous solutions include nitric acid aqueous solutions, ascorbic acid aqueous solutions, and the like, and alkaline aqueous solutions include sodium hydroxide aqueous solutions, potassium hydroxide aqueous solutions, and the like.

According to the present invention, when the waste water containing at least one nitrogen-containing compound, organic substances and inorganic substances (contaminative components) is subjected to wet oxidation treatment, since a part of the high-temperature liquid phase obtained by gas-liquid separation after the wet oxidation treatment is thermally regenerated Circulation, to maintain the liquid linear velocity in the tower, even if a large amount of air (oxygen) or oxygen-containing gas is used and processed under high temperature and high pressure conditions, no external heating is required, and a good liquid phase state can be maintained, continue reaction.

Moreover, according to the present invention, since the amount of metal components attached to the surface of the catalyst can be reduced, and the liquid film resistance on the surface of the catalyst can be reduced, the activity and durability of the catalyst can be improved, and wastewater can be effectively treated without being limited by the concentration of dirty components.

Moreover, according to the present invention, since each step can be carried out continuously, the processing flow is very simple, so the processing cost (equipment cost, transportation cost, etc.) is significantly reduced, and process management becomes easy.

Moreover, according to the second treatment method of the present invention, after the waste water is subjected to short-term wet oxidation treatment under a relatively mild pressure below 10kg/cm ² (0.98MPa), the residual COD in the water can be decomposed and treated by the activated sludge method, Moreover, NH ₄ -N and/or (NO ₂ +NO ₃ )-N remaining in water can be decomposed and treated through biological denitrification treatment.

Furthermore, according to the second treatment method, when using a gas with a high oxygen concentration (for example, pure oxygen), wastewater treatment can be performed in minute time units under relatively low pressure conditions of 10kg/cm ² (0.98MPa) or less.

Furthermore, according to the first treatment method, when wastewater treatment is performed under subcritical, critical or supercritical conditions using oxygen-containing gas, the operation can be completed in seconds. Ⅱ. Inventions involving catalyst washing and regeneration methods

Usually, when wet oxidation treatment of wastewater is carried out at a high temperature above 100°C, if a catalyst is used, the chemical erosion of the catalyst metal caused by the precipitation, precipitation, and decomposition products of the dirty components and their decomposition products in the wastewater, and the microscopic surface of the catalyst metal The changes in the chemical and physical properties of the catalyst lead to a gradual decrease in catalyst activity. In particular, the changes in the chemical and physical properties of the metal surface of the catalyst are different from precipitation, precipitation, erosion, etc., which are easily observed through a microscope. Such changes are difficult to grasp. In addition, it is not clear what substances affect the catalyst activity. Influence. However, it can be presumed that such a change in chemical and physical properties of the catalyst surface is caused by a catalyst activity inhibiting factor equal to or more serious than the erosion phenomenon of the catalyst surface. By adopting the method of the present invention, the activity of the catalyst subjected to washing treatment in a gas-liquid mixed phase state can be restored to be equal to or higher than that of the catalyst treated by the method of the prior application. In particular, depending on the type of wastewater to be treated, the composition of the catalyst, etc., when the regeneration treatment is performed under optimal conditions, its activity can be restored to almost the same level as that of a new catalyst.

Adopt the method of the present invention to wash and regenerate the waste water oxidation catalyst, its catalyst active component contains the water-insoluble even difficult at least one of the soluble compounds. Compounds that are insoluble or poorly soluble in water are (i) ferric oxide, ferric oxide, cobalt monoxide, nickel monoxide, ruthenium dioxide, rhodium trioxide, palladium monoxide, iridium dioxide, copper oxide , tungsten dioxide and other oxides, (ii) chlorides such as ruthenium chloride and platinum chloride, (iii) sulfides such as ruthenium sulfide and rhodium sulfide, etc.

The present invention includes various forms according to the scrubbing liquid for regeneration of the catalyst, each of which will be described in detail below.

Ⅰ. In the first aspect of the present invention, the waste water oxidation catalyst whose catalytic activity has been reduced is washed with an acidic aqueous solution under the condition of blowing air.

As the acidic aqueous solution, nitric acid aqueous solution, ascorbic acid aqueous solution, etc. are preferably used. The concentration of the acidic aqueous solution varies depending on the degree of reduction in the activity of the wastewater oxidation catalyst, etc., but is usually 1% by weight or more, more preferably 5 to 10% by weight.

The amount of air to be introduced is 10 Nm ³ /hr or more, more preferably 10 to 100 Nm ³ /hr, relative to 1 m ³ /hr of washing liquid.

The conditions for washing the wastewater oxidation catalyst in the gas-liquid mixed state can be determined according to the degree of reduction in catalyst activity, the type of catalyst, the degree of recovery of catalyst activity required, the type and concentration of the washing liquid, etc., and are not particularly limited. Normal temperature=20° C. or higher (more preferably 40 to 90° C.) for 15 minutes or longer (more preferably 30 to 180 minutes). The pressure at the time of washing may be atmospheric pressure, and it is not necessary to pressurize, but it may be performed under pressurized conditions.

The washing treatment of the wastewater oxidation catalyst can be carried out by introducing air and washing liquid while the reaction tower for wet wastewater oxidation is stopped. Especially when two or more reaction towers for wet oxidation treatment of wastewater are used, it is not necessary to stop the wastewater treatment, and the wastewater oxidation catalysts in several reaction towers can be alternately regenerated.

Alternatively, the catalyst can also be taken out from the reaction tower and loaded into another treatment tank for treatment.

The catalyst after washing can be washed with water if necessary, and then reused. In addition, when the catalyst activity cannot be sufficiently restored by washing once, the same washing and regeneration treatment may be performed multiple times.

Ⅱ. In the second mode of the present invention, the wastewater oxidation catalyst with reduced catalytic activity is washed with an alkaline aqueous solution under the condition of feeding air.

As the alkaline aqueous solution, it is preferable to use an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, or the like. Among them, aqueous sodium hydroxide solution is more preferable. The concentration of the alkaline aqueous solution varies depending on the degree of reduction in the activity of the wastewater oxidation catalyst, etc., but is usually 1% by weight or more, more preferably 5 to 10% by weight.

When washing with an alkaline aqueous solution, the amount of air to be introduced, washing conditions, washing methods, washing with water if necessary, drying, repeated washing, etc. are all the same as when washing with an acidic aqueous solution.

Ⅲ. In the third mode of the present invention, the waste water oxidation catalyst whose catalytic activity is reduced is washed with an acidic aqueous solution under the condition of passing air, and then washed with an alkaline aqueous solution under the condition of passing air. In this two-step washing method, when washing with an alkaline aqueous solution and when washing with an acidic aqueous solution, the amount of air to be introduced, washing conditions, washing methods, and repeated water washing, drying, washing, etc. if necessary, are respectively the same as the above-mentioned first method. Same as in the 2nd way.

IV. In the fourth mode of the present invention, the wastewater oxidation catalyst whose catalytic activity is reduced is washed with an alkaline aqueous solution under the condition of feeding air, and then washed with an acidic aqueous solution under the condition of feeding air. In this two-step washing method, when washing with an alkaline aqueous solution and when washing with an acidic aqueous solution, the amount of air to be introduced, washing conditions, washing methods, and repeated water washing, drying, washing, etc. if necessary, are respectively the same as the above-mentioned first method. Same as in the 2nd way.

V. In addition, the washing waste liquid generated in the first to fourth embodiments above can be subjected to solid-liquid separation by, for example, coagulation and sedimentation treatment, and then its liquid phase can be subjected to a known wet oxidation treatment together with the waste water (for example, the above-mentioned inventor proposed "Wastewater Wet Contact Oxidation Treatment Method"). At this time, cross-processing can be performed as long as it involves the liquid phase from wastewater.

According to the present invention, the following remarkable effects can be achieved.

(a) The activity of the wastewater oxidation catalyst can be recovered to the extent that it can be reused because the factor of catalyst activity reduction can be largely eliminated by a simple operation.

(b) According to the selection of the most suitable regeneration treatment conditions for the catalyst, the activity of the regenerated catalyst can be restored to the level comparable to that of the new catalyst.

(c) Since the use and regeneration of the catalyst can be repeated, the overall lifetime of the catalyst can be significantly increased.

(d) Since the catalyst cost required for wastewater treatment is reduced, the wastewater treatment fee can be reduced.

(e) Especially when two or more reaction towers for wet wastewater oxidation treatment are used, it is not necessary to stop the wastewater treatment, and the degraded wastewater oxidation catalysts in several reaction towers can be regenerated alternately, so there is no need to take out and recycle the catalysts. Filling and other labor.

(f) Since metal components adhering to heat exchangers, gas-liquid separators, coolers, various piping, etc. in waste water wet oxidation equipment can also be washed and removed at the same time, it is possible to prevent these machines from being blocked and prevent thermal conductivity from decreasing, etc. Effect.

Below in conjunction with embodiment and comparative example further illustrate the feature of the present invention.

Examples 1A-2A and Comparative Examples 1A-2A

According to the process shown in Figure 1, the first treatment method is adopted to process the gas liquid (containing nitrogen-containing compounds, organic substances and inorganic substances) produced by the coke oven factory with the properties described in Table 1.

Table 1 pH 9.5 COD 6500mg/l NH ₄ -N 2600mg/l TN 2900mg/l

Example 1A: Coal gas liquid is supplied to the reaction tower, the superficial velocity in the tower is 4hr ^-1 (based on the empty tower volume), the liquid linear velocity in the tower is 0.71cm/sec, and the mass velocity is ^25.5m3 / ^m2 . hr, while supplying air, the superficial velocity is 80.4hr ^-1 (converted according to the standard state). The air supply amount is equivalent to 1.1 times of the theoretical oxygen amount. In addition, the reaction tower is filled with a spherical catalyst (about 5 mm in diameter), which is supported by titanium oxide and loaded with 2% ruthenium by weight of the carrier, while being kept at a temperature of 250° C. and a pressure of 70 kg/cm ² ·G.

The treatment liquid obtained in the reaction tower is introduced into the first gas-liquid separator for gas-liquid separation, and a part of the obtained liquid phase (the same as the supplied gas-liquid amount) is thermally recirculated with the reaction tower, and the first gas-liquid separator is recirculated with a heat exchanger at the same time. The gas-liquid phase obtained by the first gas-liquid separator is heat-recovered, cooled by a cooler, and then separated into exhaust gas and treated water by the second gas-liquid separator.

Table 2 shows the composition of the treated water obtained 100 hours after the start of the reaction.

In addition, in this Example 1A, COD and NH ₄ -N in the treated water were less than 10 mg/l after 8000 hours of operation.

Example 2A: The wet oxidation treatment of gas liquid was carried out according to the method of Example 1A except that the amount of hot recirculating liquid was changed to 1/2. However, due to the halving of the thermal recirculation liquid volume, the superficial velocity in the tower related to the gas liquid is 3hr ^-1 (based on the empty tower volume), the linear velocity of the liquid in the tower is 0.53cm/sec, and the mass velocity is 19.1m ³ /m ² ·hr.

Table 2 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Comparative Example 1A: Except for not performing heat recirculation, the wet oxidation treatment of coal gas liquid was carried out according to the method of Example 1A. However, due to the omission of thermal recirculation, the superficial velocity in the tower related to gas and liquid is 2hr ^-1 (based on the empty tower volume), the liquid linear velocity in the tower is 0.35cm/sec, and the mass velocity is 12.7m ³ /m ² hours.

Table 2 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Comparative Example 2A: Except for changing the diameter of the reaction tower, the wet oxidation treatment of gas liquid was carried out according to the method of Example 1A. However, due to the change of the diameter of the reaction tower, the superficial velocity in the tower related to the gas-liquid is 2hr ^-1 (based on the empty tower volume), the linear velocity of the liquid in the tower is 0.088cm/sec, and the mass velocity is 3.2m ³ /m ² hours. Table 2 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Table 2 COD (mg/l) NH ₄ -N (mg/l) Example 1A 1.8 <1 Example 2A 5.5 <1 Comparative Example 1A 11 <1 Comparative Example 2A 26 2.5

It can be seen from the results shown in Table 2 that by performing thermal recycling, the liquid linear velocity in the tower can be increased, the liquid film resistance on the catalyst surface can be reduced, and at the same time, since the metal components can be inhibited from adhering to the catalyst surface, a higher catalyst can be maintained for a long time. Active, improving the water quality of treated water.

In addition, the time to reach the same treated water quality as in Example 2A was 450 hours in Example 1A, 340 hours in Example 2A, and 200 hours in Comparative Example 1A.

In addition, in any of Examples 1A to 2A and Comparative Examples 1A to 2A, _NOx , _SOx, and _NH4 -N were not detected in the exhaust gas (gas phase).

Embodiment 3A～12A

The gas-liquid treatment was carried out in the same manner as in Example 1A except that the combination of the catalyst component and the carrier was changed. Table 3 shows the composition of the treated water obtained 100 hours after the start of the reaction.

table 3 catalyst COD (mg/l) NH4-N(mg/l) Example 3A 1%Ir-TiO ₂ 2.9 <1 Example 4A 0.5%Pt- _TiO2 2.1 <1 Example 5A 1% Au-TiO ₂ 3.0 <1 Example 6A 0.5%Pd-TiO ₂ 1.9 <1 Example 7A 1% Rh-TiO ₂ 1.9 <1 Example 8A 5% Fe-TiO ₂ 4.5 2.5 Example 9A 5% Ni-TiO ₂ 4.0 1.5 Example 10A 5%W- _TiO2 7.8 4.9 Example 11A 5% Cu-TiO ₂ 2.1 4.0 Example 12A 5% Co-ZrO ₂ 2.1 <1

Example 13A

According to the process shown in Figure 1, according to the first treatment method, the coal gas scrubber wastewater generated in the coal gasification project is passed into the tower filled with ion exchange resin, and after the ammonia component is removed by adsorption, it is treated with sulfuric acid aqueous solution. Attached is wastewater containing ammonia (pH=6.6, COD=1.9mg/l, NH4-N=2100mg/l, T-N=2100mg/l).

That is to say, the above wastewater is supplied to the reaction tower, the superficial velocity in the tower is 8hr ^-1 (based on the empty tower volume), the liquid linear velocity in the tower is 0.88cm/sec, and the mass velocity is ^31.8m3 / ^m2 . hr, while supplying oxygen-enriched air (90% oxygen concentration) as an oxygen-containing gas, the superficial velocity is 13.4hr ^-1 (converted according to the standard state). The supply amount of the oxygen-containing gas is equivalent to 1.5 times the theoretical oxygen amount. In addition, the reaction tower is filled with a spherical catalyst (about 1.5 mm in diameter), which is supported by titanium oxide and loaded with 2.3% ruthenium by weight of the carrier, while maintaining a temperature of 200° C. and a pressure of 20 kg/cm ² ·G.

The treated liquid obtained from the reaction tower is introduced into the first gas-liquid separator for gas-liquid separation, and a part of the obtained liquid phase (the same as the amount of waste water supplied) is thermally recycled with the reaction tower, and the waste water used for heating the waste water is recirculated with a cooler. After the gas phase is cooled, it is separated into exhaust gas and treated water by the second gas-liquid separator.

Table 4 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Example 14A

In addition to (i) the temperature during the reaction is 170 ° C, the pressure is 9.9kg/cm ² G, (ii) the liquid superficial velocity in the reaction tower (based on the empty tower volume) is 4hr ^-1 (that is, the catalyst loading is 2 times of embodiment 13A), (iii) add 48% NaOH in advance in waste water, its pH is adjusted to 9.7, and (iv) the superficial velocity of oxygen-containing gas is 6.7hr ^-1 outside, according to embodiment 13A In the same way, waste water containing ammonia is treated. Table 4 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Example 15A

Except (i) the superficial velocity of the liquid in the reaction tower (based on the empty tower volume) is 2hr ^-1 (that is, the catalyst loading is 2 times that of Example 14) and (ii) the superficial velocity of the oxygen-containing gas (based on the empty tower volume) Tower volume is a benchmark) is 3.4hr ^-1 except, according to the method identical with embodiment 13A, process the wastewater containing ammonia. Table 4 shows the composition of the treated water obtained 100 hours after the start of the reaction.

In addition, in this example, 1.1 times the theoretical amount of H ₂ O ₂ needed to decompose NH ₄ -N=120 mg/l is added to the 2/3 of the position below the catalyst filling part of the reaction tower, and the almost same result as in Example 14A can be obtained. result.

Example 16A

Except that 48% NaOH was added to the wastewater to adjust its pH to 11.5, the wastewater containing ammonia was treated in the same manner as in Example 15A. Table 4 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Table 4 COD (mg/l) NH ₄ -N (mg/l) (NO ₂ +NO ₃ )-N(mg/l) TN (mg/l) Example 13A 1.0 <1 <1 <1 Example 14A 1.2 <1 <5 <5 Example 15A 1.6 120 <5 120 Example 16A 1.1 <1 150 150

Example 17A

In addition to setting the treatment temperature and treatment pressure of ammonia-containing wastewater to 380 °C and 230 kg/cm ² respectively exceeding the critical temperature (374 °C) and critical pressure (220 kg/cm ² ), the velocity of liquid in the reaction tower (in the form of empty Tower volume is benchmark) be 240hr ^-1 (that is catalyst loading is 1/62.5 of embodiment 13A), according to the method identical with embodiment 13A, process the waste water that contains ammonia. Table 5 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Comparative Example 3A

The ammonia-containing wastewater was treated in the same manner as in Example 17A, except that the treatment temperature of the ammonia-containing wastewater was 630° C. and no catalyst was used. Table 5 shows the composition of the treated water obtained 100 hours after the start of the reaction.

table 5 COD (mg/l) NH ₄ -N (mg/l) (NO ₂ +NO ₃ )-N(mg/l) TN (mg/l) Example 17A 1.0 <1 <1 <1 Comparative Example 3A 1.9 110 25 135

Example 18A

According to the process shown in Figure 1, the first treatment method is adopted to treat the wastewater containing organic substances (pH=2.6, COD=28100mg/l, TOD=101800mg/l, TOC=36500mg/l, NH ₄ - N less than 1mg/l, TN less than 1mg/l). Organic substances in wastewater are acetic acid, acrylic acid, formaldehyde, formic acid, etc.

That is to say, the above-mentioned wastewater is supplied to the reaction tower, the superficial velocity in the tower is 2.9hr ^-1 (based on the empty tower volume), the liquid linear velocity in the tower is 0.71cm/sec, and the liquid mass velocity is 25.5m ³ /m ² ·hr, while supplying air as an oxygen-containing gas, the superficial velocity is 553hr ^-1 (converted according to the standard state). The air supply amount is equivalent to 1.5 times of the theoretical oxygen amount. In addition, the reaction tower is filled with a spherical catalyst (about 5 mm in diameter), which is supported by titanium oxide and loaded with 1.5% ruthenium by weight of the carrier, while maintaining a temperature of 270° C. and a pressure of 90 kg/cm ² ·G.

The treated liquid obtained from the reaction tower is introduced into the first gas-liquid separator for gas-liquid separation, and a part of the obtained liquid phase (the same as the supplied gas-liquid amount) is thermally recirculated with the reaction tower, and the heated waste water is used with a cooler. After the gas phase is cooled, it is separated into exhaust gas and treated water by the second gas-liquid separator.

In this embodiment, 0.84 ton/hr of steam with a pressure of 24 kg/cm ² can be recovered at the outlet of the reactor.

Table 4 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Comparative Example 4A

Wet oxidation treatment of wastewater was performed in the same manner as in Example 18A, except that thermal recycling was not performed. However, due to the omission of thermal recirculation, the superficial velocity in the column related to wastewater is 1.5hr ^-1 (based on the empty column volume), the liquid linear velocity in the column is 0.35cm/sec, and the mass velocity is 12.7m ³ / m ² ·hr.

Table 6 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Table 6 COD (mg/l) TOC (mg/l) NH ₄ -N (mg/l) TN (mg/l) Example 18A <3 <5 <1 <1 Comparative Example 4A 28.1 12 <1 <1

In addition, the time for Example 18A to reach the same treated water quality as that of Comparative Example 4A was 350 hours.

In addition, in either of Example 18A and Comparative Example 4A, _NOx , _SOx , and _NH4 -N were not detected in the exhaust gas (gas phase).

Furthermore, in Example 18A, COD and TOD in the treated water were also less than 10 mg/l after 8000 hours of operation.

Examples 1B-2B and Comparative Examples 1B-2B

According to the flow process shown in Fig. 2, adopt the method of the present invention, process the coal gas liquid (containing nitrogen-containing compound, organic substance and inorganic substance) that the coke oven factory of character described in Table 7 produces.

Table 7 pH 9.5 COD 6500mg/l NH ₄ -N 2600mg/l TN 2900mg/l

Example 1B: Coal gas liquid is supplied to the reaction tower, the superficial velocity in the tower is 8hr ^-1 (based on the empty tower volume), the liquid linear velocity in the tower is 0.71cm/sec, and the mass velocity is ^25.5m3 / ^m2 . hr, and at the same time supply high-purity oxygen-containing gas with an oxygen concentration of 92.5% (compress the air and use a PSA device to increase the oxygen concentration), and the superficial velocity is 24.9hr ^-1 (converted according to the standard state). The gas supply amount is equivalent to 1.5 times the theoretical oxygen amount. In addition, the reaction tower is filled with a spherical catalyst (about 5 mm in diameter), which is supported by titanium oxide and loaded with 2% ruthenium by weight of the carrier, while maintaining a temperature of 250° C. and a pressure of 46 kg/cm ² ·G.

The treatment liquid obtained in the reaction tower is introduced into the first gas-liquid separator for gas-liquid separation, and a part of the obtained liquid phase (the same as the supplied gas-liquid amount) is thermally recirculated with the reaction tower, and the first gas-liquid separator is recirculated with a heat exchanger at the same time. The gas-liquid phase obtained by the first gas-liquid separator is heat-recovered, cooled by a cooler, and then separated into exhaust gas and treated water by the second gas-liquid separator.

Then, the obtained treated water is subjected to biological denitrification treatment. Biological denitrification treatment is to add methanol 2.5 times the number of moles of residual ammonia in the treated water, and carry out sequentially through the nitrification reaction using nitrifying bacteria and the denitrification reaction using denitrifying bacteria under the conditions of 30 ° C and pH 7.2.

Table 8 shows the compositions of wet oxidation treated water and denitrified treated water (values in parentheses) obtained 100 hours after the start of the reaction.

In addition, in this Example 1B, COD and NH ₄ -N in the denitrification treated water were less than 10 mg/l after 8000 hours of operation.

Example 2B: The wet oxidation treatment of gas liquid was carried out according to the method of Example 1B, except that the amount of hot recirculating liquid was changed to 1/2. However, due to the halving of the thermal recirculation liquid volume, the superficial velocity in the tower related to the gas liquid is 6hr ^-1 (based on the empty tower volume), the liquid linear velocity in the tower is 0.53cm/sec, and the mass velocity is 19.1m ³ /m ² ·hr.

Table 8 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Comparative Example 1B: Except for not performing thermal recycling, the wet oxidation treatment of coal gas liquid was carried out according to the method of Example 1B. However, due to the omission of thermal recirculation, the superficial velocity in the tower related to gas and liquid is 4hr ^-1 (based on the empty tower volume), the liquid linear velocity in the tower is 0.35cm/sec, and the mass velocity is 12.7m ³ /m ² hours.

Table 8 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Comparative Example 2B: Except for changing the diameter of the reaction tower, the wet oxidation treatment of gas liquid was carried out according to the method of Example 1B. However, due to the change of the diameter of the reaction tower, the superficial velocity in the tower related to the gas-liquid is 4hr ^-1 (based on the empty tower volume), the linear velocity of the liquid in the tower is 0.088cm/sec, and the mass velocity is 3.2m ³ /m ² hours.

Table 8 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Table 8 COD (mg/l) NH ₄ -N (mg/l) (NO ₂ +NO ₃ )-N(mg/l) TN (mg/l) Example 1B 4.0(3.0) <1 (<1) 45(＜10) 45(＜10) Example 2B 8.2(7.0) <1.2 (<1) 50(＜10) 52 (<10) Comparative Example 1B 14.0(13.0) ＜2.1(＜1) 63 (<10) 65(＜10) Comparative Example 2B 35.1(30.5) 9.1 (<1) 120 (<10) 130 (<10)

It can be seen from the results shown in Table 8 that the liquid linear velocity in the tower can be increased by thermal recycling, and the liquid film resistance on the catalyst surface can be reduced. At the same time, since the metal components from the wastewater can be inhibited from adhering to the catalyst surface, a relatively high temperature can be maintained for a long time. High catalyst activity improves the water quality of treated water after wet oxidation. Moreover, the biological denitrification treatment of the same treated water can further improve the water quality.

In addition, in any of Examples 1B to 2B and Comparative Examples 1B to 2B, _NOx , _SOx, and _NH4 -N were not detected in the exhaust gas (gas phase).

In addition, the time to achieve the same treatment water quality as in Example 2B was 470 hours in Example 1B, 365 hours in Example 2B, and 230 hours in Comparative Example 1B.

Embodiment 3B～12B

The gas-liquid treatment was carried out in the same manner as in Example 1B except that the combination of the catalyst component and the carrier was changed.

Table 9 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Table 9 catalyst COD (mg/l) NH ₄ -N (mg/l) Example 3B 1%Ir-TiO ₂ 4.1 <10 Example 4B 0.5%Pt- _TiO2 3.9 <10 Example 5B 1% Au-TiO ₂ 3.9 <10 Example 6B 0.5%Pd-TiO ₂ 1.9 <10 Example 7B 1% Rh-TiO ₂ 2.0 <10 Example 8B 5% Fe-TiO ₂ 9.4 <10 Example 9B 5% Ni-TiO ₂ 8.9 <10 Example 10B 5%W- _TiO2 9.4 <10 Example 11B 5% Cu-TiO ₂ 4.3 <10 Example 12B 5% Co-ZrO ₂ 2.9 <10

Example 13B

According to the process shown in Figure 2, according to the second treatment method, the coal gas scrubber wastewater generated in the coal gasification project is passed into the tower filled with ion exchange resin, and after the ammonia component is removed by adsorption, it is treated with sulfuric acid aqueous solution. Attached is wastewater containing ammonia (pH=6.6, COD=1.9mg/l, NH ₄ -N=2100mg/l, (NO ₂ +NO ₃ )-N=ND, TN=2100mg/l).

That is to say, the above-mentioned waste water is supplied to the reaction tower, the superficial velocity in the tower is 10hr ^-1 (based on the empty tower volume), the liquid linear velocity in the tower is 0.88cm/sec, and the mass velocity is 31.8m ³ /m ² · hr, while supplying oxygen-enriched air (oxygen concentration 95%) as oxygen-containing gas, the superficial velocity is 15.9hr ^-1 (converted according to standard state). The supply amount of the oxygen-containing gas is equivalent to 1.5 times the theoretical oxygen amount. In addition, the reaction tower is filled with a spherical catalyst (about 1.5 mm in diameter), which is supported by titanium oxide and loaded with 2.3% ruthenium by weight of the carrier, while maintaining a temperature of 200° C. and a pressure of 20 kg/cm ² ·G.

The treated liquid obtained from the reaction tower is introduced into the first gas-liquid separator for gas-liquid separation, and a part of the obtained liquid phase (the same as the supplied gas-liquid amount) is thermally recirculated with the reaction tower, and the heated wastewater is cooled by a cooler at the same time. After the used gas phase is cooled, it is separated into exhaust gas and treated water by the second gas-liquid separator.

Then, according to the same method as in Example 1B, the obtained wet oxidation treatment water was subjected to biological denitrification treatment.

Table 10 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Example 14B

In addition to (i) the temperature during the reaction is 170°C, the pressure is 9.9kg/cm ² G, (ii) the liquid empty column velocity (based on the empty column volume) in the reaction tower is 5hr ^-1 (that is, the catalyst loading is 2 times of embodiment 13B), (iii) add 48% NaOH in advance in waste water, its pH is adjusted to 9.7, and (iv) the superficial velocity of oxygen-containing gas is 7.95hr ^-1 , according to embodiment 13B The same method, wet oxidation treatment of wastewater containing ammonia, followed by biological denitrification treatment.

Table 10 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Example 15B

Except that 48% NaOH was added to the wastewater to adjust its pH to 11.5, the wastewater containing ammonia was treated by wet oxidation in the same manner as in Example 14B, followed by biological denitrification treatment. Table 10 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Table 10 COD (mg/l) NH ₄ -N (mg/l) (NO ₂ +NO ₃ )-N(mg/l) TN (mg/l) Example 13B 1.1 (1.0) <1 (<1) <1 (<1) <1 (<10) Example 14B 1.9(1.6) <12.5 (<10) <1 (<1) 120 (<10) Example 15B 1.9(1.3) 4.5(<1) 165 (<10) 150 (<10)

Comparative Example 3B

In addition to setting the treatment temperature and treatment pressure of ammonia-containing wastewater to 380 °C and 230 kg/cm ² respectively exceeding the critical temperature (374 °C) and critical pressure (220 kg/cm ² ), the velocity of liquid in the reaction tower (in the form of empty Tower volume is benchmark) be 240hr ^-1 (that is catalyst loading is 1/62.5 of embodiment 14B), according to the method identical with embodiment 13B, only wet oxidation treatment is carried out to the waste water containing ammonia. The water quality of the treated water and the properties of the exhaust gas were almost the same as in Example 13B.

Example 16B

According to the process shown in Figure 2, the second treatment method is used to treat the wastewater containing organic substances obtained from petrochemical plants (pH=2.6, COD=28100mg/l, TOD=101800mg/l, TOC=36500mg/l, NH ₄ - N<1mg/l or less, TN<1mg/l or less). Organic substances in wastewater are acetic acid, acrylic acid, formaldehyde, formic acid, etc.

That is to say, the above-mentioned wastewater is supplied to the reaction tower, the superficial velocity in the tower is 2.9hr ^-1 (based on the empty tower volume), the liquid linear velocity in the tower is 0.71cm/sec, and the liquid mass velocity is 25.5m ³ /m ² ·hr, while supplying oxygen-enriched air (92.5% oxygen concentration) as oxygen-containing gas, the superficial velocity is 116hr ^-1 (converted according to standard state). The supply amount of the oxygen-enriched gas corresponds to 1.2 times the theoretical oxygen amount. In addition, a spherical catalyst (about 5 mm in diameter) was filled in the reaction tower, and the spherical catalyst was supported by titanium oxide, loaded with platinum at a loading weight of 1.5%, while maintaining a temperature of 270° C. and a pressure of 67 kg/cm ² .

The treated liquid obtained from the reaction tower is introduced into the first gas-liquid separator for gas-liquid separation, and a part of the obtained liquid phase (the same as the supplied gas-liquid amount) is thermally recirculated with the reaction tower, and the heated waste water is used with a cooler. After the gas phase is cooled, it is separated into exhaust gas and treated water by the second gas-liquid separator.

Then, the obtained wet oxidation treatment water (temperature about 30° C., pH 7.4) was treated by activated sludge method.

Table 11 shows the composition of the treated water obtained 100 hours after the start of the reaction.

In this embodiment, steam with a pressure of 24 kg/cm ² can be recovered at a rate of 0.84 ton/hr at the outlet of the reactor.

Comparative Example 4B

Wet oxidation treatment of wastewater was performed in the same manner as in Example 16B, except that thermal recycling was not performed. However, due to the omission of thermal recirculation, the superficial velocity in the column related to wastewater is 1.5hr ^-1 (based on the empty column volume), the liquid linear velocity in the column is 0.35cm/sec, and the mass velocity is 12.7m ³ / m ² ·hr.

Table 11 shows the composition of the treated water obtained 100 hours after the start of the reaction.

Table 11 COD (mg/l) TOC (mg/l) NH ₄ -N (mg/l) TN (mg/l) Example 16B <3(1.8) <5 (<5) <1 (<1) <1 (<1) Comparative Example 4B 275 (<13) <15 (<10) <1 (<1) 1(<1)

From the results shown in Table 11, it can be seen that the liquid linear velocity in the tower can be increased and the liquid film resistance on the surface of the catalyst can be reduced through thermal recycling. At the same time, since the metal components from the wastewater can be inhibited from adhering to the surface of the catalyst, a relatively high temperature can be maintained for a long time. High catalyst activity improves the water quality of treated water after wet oxidation. Moreover, biological treatment of the same treated water can further improve the water quality.

In addition, in either of Example 16B and Comparative Example 4B, _NOx , _SOx , and _NH4 -N were not detected in the exhaust gas (gas phase).

Furthermore, in Example 16B, COD and TOD in the treated water were less than 10 mg/l after 8000 hours of operation.

Embodiment 1C～8C

(1) Wet oxidation treatment of wastewater

Firstly, the gas liquid (COD 6000ppm, total ammonia 3000ppm, total nitrogen 4000ppm) produced in the coke furnace is subjected to wet oxidation treatment.

That is, an aqueous sodium hydroxide solution was added to the gas liquid to adjust its pH to about 10, and it was supplied to the lower part of the cylindrical reactor at a space velocity of 1.0 hr ^-1 (based on the empty column). The mass velocity of the liquid is 8.0 m ³ /m ² ·hr.

On the other hand, air was supplied to the lower part of the reaction tower at a space velocity of 65 hr ^-1 (based on the empty tower, standard state).

A spherical waste water oxidation catalyst (about 5 mm in diameter) having a composition described in Table 12 below was filled in the reaction tower. In Table 12, 1%Ir- _TiO2 refers to a catalyst in which 1% by weight of iridium is supported on a titania carrier.

In addition, the gas liquid used originally contained a total of 15ppm of iron, calcium and magnesium. In order to further clarify the effect of the present invention, compounds containing these elements were added in advance to make the total amount 2500ppm.

In the wet oxidation treatment of gas liquid, the temperature inside the reaction tower is maintained at 250°C and the pressure is 70kg/cm ² ·G, sodium hydroxide aqueous solution is added to make the pH of the treatment liquid after wet oxidation treatment reach about 7.5, and the reaction is continued for 5000 hours. As a result, the activity index of the catalyst decreased, as shown in Table 12. The precipitates on the surface of the catalyst were analyzed to confirm the presence of sulfur and ash (silicon dioxide, iron oxide, magnesium oxide, etc.), but no carbon, hydrocarbons, etc. were detected.

(2) Catalyst regeneration and washing treatment

Then, the wastewater oxidation catalyst whose activity has decreased is regenerated by the following various methods.

*Method-1: Pass 10% nitric acid aqueous solution (80° C.) into the reaction tower filled with wastewater oxidation catalyst under atmospheric pressure, wash with water for 1 hour after washing for 1 hour. The feed conditions of nitric acid aqueous solution and water are the same as those of waste water during waste water treatment.

*Method-2: Air and 10% aqueous nitric acid solution (80° C.) were introduced into the reaction tower filled with the wastewater oxidation catalyst under atmospheric pressure, and after washing for 1 hour, washed with water for 1 hour. The feed conditions of nitric acid aqueous solution and air are the same as those of waste water and air during waste water treatment. That is, the air flow rate was 65 Nm ³ /hr with respect to 1 m ³ /hr of the nitric acid aqueous solution.

In addition, the conditions for passing water during washing with water are the same as the conditions for passing waste water during waste water treatment.

*Method-3: Pass 10% aqueous sodium hydroxide solution (80° C.) into the reaction tower filled with wastewater oxidation catalyst under atmospheric pressure, wash with water for 1 hour after washing for 1 hour. The feed conditions of sodium hydroxide aqueous solution and water are the same as those of waste water during waste water treatment.

*Method-4: Air and 10% aqueous sodium hydroxide solution (80° C.) were introduced into the reaction tower filled with the wastewater oxidation catalyst under atmospheric pressure, washed with water for 1 hour after washing for 1 hour. The feeding conditions of the aqueous sodium hydroxide solution and the air are the same as the feeding conditions of the waste water and the air during the waste water treatment. That is, the air flow rate was 65 Nm ³ /hr relative to 1 m ³ /hr of the sodium hydroxide aqueous solution.

In addition, the conditions for passing water during washing with water are the same as the conditions for passing waste water during waste water treatment.

Table 12 Example Catalyst composition pre-regeneration activity index Method 1 Activity Index Method 2 Activity Index Method 3 Activity Index Method 4 activity index 1C 1%Ir-TiO ₂ 65 73 93 83 98 2C 1%Pt-TiO ₂ 67 74 93 84 99 3C 1% Au-AlO ₂ 54 69 88 74 94 4C 5%Ni- _AlO2 54 68 87 73 95 5C 5%W- _AlO2 66 69 88 72 96 6C 2% Pd-activated carbon 67 71 94 87 99 7C 1% Pt-activated carbon 63 69 92 79 99 8C 2% Ru-TiO ₂ 69 84 97 93 100

In Table 12, "activity index" refers to the removal rate of ammonia under the same conditions when the wet oxidation treatment of wastewater is carried out using a regenerated catalyst when the ammonia removal rate is 100% when using a new catalyst for wet oxidation treatment of wastewater. It was confirmed that the regenerated catalyst also showed an increase in the activity index for COD removal as well as for ammonia removal.

As can be seen from the results shown in Table 12, the excellent effect of the present invention is achieved when the wastewater oxidation catalyst is washed and regenerated with an acidic aqueous solution or an alkaline aqueous solution under the condition of feeding air.

Comparative Example 1C

Using the same catalyst as in Example 1C, under the same conditions as in Example 1, wet oxidation treatment was performed on the gas liquid.

Then, using 2N sulfuric acid aqueous solution as the washing solution of the catalyst, the method-1 and method-2 in Example 1C were used to regenerate the catalyst. The results are shown in Table 13.

Table 13 comparative example Catalyst composition pre-regeneration activity index Method 1 Activity Index Method 2 Activity Index 1C 1%Ir-TiO ₂ 65 66 67

As can be seen from the results shown in Table 13, when sulfuric acid aqueous solution is used as the washing liquid, the regeneration effect of the catalyst cannot be fully achieved.

Comparative Example 2C

Using the same catalyst as in Example 2C and under the same conditions as in Example 2C, wet oxidation treatment was performed on the gas liquid.

Then use 10% nitric acid aqueous solution, adopt method-1 and method-2 in embodiment 2C to carry out washing regeneration of catalyst. However, in Method-2, the air flow rate was 5 Nm ³ /hr relative to 1 m ³ /hr of washing liquid. The results are shown in Table 14.

Table 14 comparative example Catalyst composition pre-regeneration activity index Method 1 Activity Index Method 2 Activity Index 2C 1%Pt-TiO ₂ 67 74 77

As can be seen from the results shown in Table 14, when the gas-liquid mixture is washed by nitric acid aqueous solution and air, if the amount of air introduced is too small, the regeneration effect of the catalyst cannot be fully achieved.

Example 9C

(1) Wet oxidation treatment of wastewater

First, the cyanide ion-containing waste liquid (pH 10.6) having the composition shown in Table 15 was subjected to wet oxidation treatment using the first reaction tower not filled with the catalyst and the second reaction tower filled with the catalyst.

Table 15 Element Concentration (mg/l) Total-CN 10000 COD _Mn 15000 TOC 5000 TOD 30240 Total-N 8000 NH ₃ -N 2615 Na 25000 K 15000 Fe 2000 Zn 145 P 240 Al 1.3 Cu 5.4

That is to say, the waste liquid is supplied to the lower part of the first reaction tower at a space velocity of 1.0hr ^-1 (based on the empty tower) and a mass velocity of 14.15m ³ /m ² ·hr, and the space velocity in the lower part of the first reaction tower is 3.4hr ^-1 (based on empty tower, standard state) supply air. The air supply amount corresponds to 0.0103 times the theoretical oxygen amount (82.5Nm ³ /kl).

When decomposing and treating waste liquid, introduce waste liquid and air at the inlet side of the heat exchanger, so that the temperature of the gas-liquid mixture at the outlet side of the heat exchanger (=the temperature of the gas-liquid mixture at the inlet side of the first reaction tower) reaches 150 ° C, through The pump circulates and mixes part of the treatment liquid from the second reaction tower with the treatment liquid from the first reaction tower to adjust the temperature. In addition, by supplying steam to the primary reaction column, the temperature inside the column was kept at 220°C and the pressure was 30 kg/cm ² . In addition, a tray type reaction tower is installed at a distance of 70 cm from the first reaction tower.

In the liquid (pH10.6) treated in the first reaction tower, the metal components in the original waste liquid become sludge, which is discharged from the lower part of the reaction tower and the lower part of the solid-liquid separator (membrane punching). Table 16 shows the composition of the first treatment liquid obtained from the solid-liquid separator.

Table 16 Element Concentration (mg/l) Total-CN 0.1 COD _Mn 1445 TOC 5000 TOD 25300 Total-N 6690 NH ₃ -N 6900 Na 20900 K 12540 Fe 47 Zn 20 P 145 Al <0.5 Cu 3.5

Then, add 0.62ml of sulfuric acid equivalent to 1/2 of the alkali metal content (Na0.909mol/l+K0.332mol/1=1.231mol/l) in the treatment solution for the first time from the sulfuric acid storage tank Afterwards, with space velocity 0.75/hr (based on empty tower) and mass velocity 14.15m ³ /m ² hr it is supplied in the second reaction tower that is filled with catalyst, simultaneously with space velocity 90.4/hr (in empty tower tower as reference, standard state) supply air. The air supply amount is equivalent to 1.1 times of the theoretical oxygen amount. In addition, a spherical catalyst (4-6mm in diameter) is filled in the second reaction tower, and the spherical catalyst is supported by titanium oxide and loaded with 2% ruthenium by weight of the carrier. Table 17 shows the composition of the treated liquid (pH3.1) obtained from the second reaction tower.

Table 17 Element Concentration (mg/l) Total-CN <0.01 COD _Mn <1 TOC <5 TOD <5 Total-N 40 NH ₃ -N <1 Na 20900 K 12540 Fe 1.0 Zn 0.3 P 0.3 al <0.5 Cu 0.3

(2) Catalyst regeneration and washing treatment

Then, use the following methods to regenerate the wastewater oxidation catalyst whose activity has been reduced after the second treatment for 16,000 hours.

*Method-1: Pass 10% ascorbic acid aqueous solution (60° C.) into the reaction tower filled with wastewater oxidation catalyst under atmospheric pressure, wash with water for 1 hour after washing for 5 hours. The feeding conditions of the ascorbic acid aqueous solution and water are the same as those of the wastewater during wastewater treatment.

*Method-2: Air and 10% ascorbic acid aqueous solution (60° C.) were passed into the reaction tower filled with the wastewater oxidation catalyst under atmospheric pressure, washed for 5 hours, and then washed with water for 1 hour. The feeding conditions of the ascorbic acid aqueous solution and air are the same as the feeding conditions of waste water and air during waste water treatment. That is, the air flow rate was 120 Nm ³ /hr relative to 1 m ³ /hr of the aqueous ascorbic acid solution.

In addition, the conditions for passing water during washing with water are the same as the conditions for passing waste water during waste water treatment.

*Method-3: Pass 10% nitric acid aqueous solution (60° C.) into the reaction tower filled with wastewater oxidation catalyst under atmospheric pressure, wash with water for 1 hour after washing for 5 hours. The feed conditions of nitric acid aqueous solution and water are the same as those of waste water during waste water treatment.

*Method-4: Air and 10% aqueous nitric acid solution (60° C.) were introduced into the reaction tower filled with the wastewater oxidation catalyst under atmospheric pressure, washed for 5 hours, and then washed with water for 1 hour. The feeding conditions of the nitric acid aqueous solution and the air are the same as the feeding conditions of the waste water and the air during the waste water treatment. That is, the air flow rate was 120 Nm ³ /hr with respect to 1 m ³ /hr of the nitric acid aqueous solution.

In addition, the conditions for passing water during washing with water are the same as the conditions for passing waste water during waste water treatment.

*Method-5: Pass 10% ascorbic acid aqueous solution (60° C.) into the reaction tower filled with wastewater oxidation catalyst under atmospheric pressure, and wash for 5 hours. Then, air and 10% nitric acid aqueous solution were blown under atmospheric pressure, and after washing for 5 hours, water was washed for 1 hour. The feeding conditions of ascorbic acid aqueous solution and nitric acid aqueous solution are the same as those of wastewater during wastewater treatment, and the feeding amount of air is 1/2 of that during wastewater treatment. That is, the air flow rate was 60 Nm ³ /hr relative to 1 m ³ /hr of the nitric acid aqueous solution.

In addition, the conditions for passing water during washing with water are the same as the conditions for passing waste water during waste water treatment.

Table 18 shows the regeneration state of the catalyst after adopting various methods.

Table 18 pre-regeneration activity index 69 Method-1 Treatment Activity Index 84 Method-2 Treatment Activity Index 97 Method-3 post-treatment activity index 89 Method-4 post-treatment activity index 92 Method-5 post-treatment activity index 100

From the results in Table 18, it can be seen that the present invention has an excellent effect when the wastewater oxidation catalyst is washed and regenerated with an acidic aqueous solution under the condition of feeding air.

In addition, when the heat exchanger and piping in the waste water wet oxidation equipment whose treatment performance was reduced due to the adhesion of metal components were treated by the above-mentioned method-5, the total thermal conductivity of the heat exchanger decreased by about 80% compared with the initial state Return to the initial state, and at the same time, the pressure loss in the tube, which has increased by about 1.5kg/cm ² compared with the initial state, returns to the initial state.

Claims (18)

1. Waste water treatment method is characterized in that comprising following two steps: (1) maintain a temperature above 100°C and at least a part of the waste water maintain the pressure of the liquid phase, and decompose nitrogen-containing compounds and/or organic substances and/or inorganic substances in the waste water into nitrogen and/or in the presence of a supported catalyst In the presence of oxygen above the theoretical oxygen amount necessary for carbon dioxide and water, wet oxidation treatment of wastewater containing at least one nitrogen-containing compound, organic substances and inorganic substances, (2) At least a part of the high-temperature liquid phase obtained by gas-liquid separation after the wet oxidation treatment is circulated and mixed with the wastewater before the wet oxidation treatment. 2. The wastewater treatment method as claimed in claim 1, the catalyst active component in the step (1) is selected from iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals At least one of water-insoluble or even poorly soluble compounds. 3. The wastewater treatment method according to claim 1, wherein the linear velocity of the liquid in the tower in the step (1) (the amount of liquid entering the tower/the cross-sectional area of the tower) is 0.1-1.0 cm/sec. 4. The wastewater treatment method according to claim 1, the oxygen source in step (1) is at least one of air, oxygen-enriched air, high-purity oxygen, _ozone and _H2O2 . 5. The wastewater treatment method according to claim 1, wherein the circulating volume of the high-temperature liquid phase in step (2) is 0.1 to 15 times that of the wastewater. 6. Waste water treatment method is characterized in that comprising following five steps: (1) maintain a temperature above 100°C and at least a part of the waste water maintain the pressure of the liquid phase, and decompose nitrogen-containing compounds and/or organic substances and/or inorganic substances in the waste water into nitrogen and/or in the presence of a supported catalyst Or in the presence of high-purity oxygen-containing gas (oxygen concentration of 80% or more) above the theoretical oxygen amount necessary for carbon dioxide and water, wet oxidation treatment of wastewater containing at least one nitrogen-containing compound, organic substances and inorganic substances, (2) At least a part of the high-temperature liquid phase obtained by the first gas-liquid separation after the wet oxidation treatment is mixed with the waste water before the wet oxidation treatment, (3) After heat exchange is performed between the high-temperature gas-liquid phase obtained by the first gas-liquid separation and the waste water before the wet oxidation treatment, the gas-liquid phase is cooled to perform the second gas-liquid separation, (4) carry out biological treatment to the liquid phase obtained by gas-liquid separation for the second time, and (5) The excess sludge generated in the biological treatment is mixed with the above-mentioned waste water circulation. 7. The wastewater treatment method according to claim 6, wherein the oxygen concentration in the gas containing high-purity oxygen in step (1) is above 80%. 8. The wastewater treatment method as claimed in claim 6, the catalyst active component in the step (1) is selected from iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals At least one of water-insoluble or even poorly soluble compounds. 9. The wastewater treatment method according to claim 6, wherein the linear velocity of the liquid in the tower in the step (1) (amount of liquid entering the tower/cross-sectional area of the tower) is 0.1-1.0 cm/sec. 10. The wastewater treatment method according to claim 6, wherein the oxygen source in step (1) is at least one of air, oxygen-enriched air, high-purity oxygen, _ozone and _H2O2 . 11. The wastewater treatment method as claimed in claim 6, wherein the circulating volume of the high-temperature liquid phase in step (2) is 0.1 to 15 times that of the wastewater. 12. The wastewater treatment method according to claim 6, wherein the biological treatment method in step (4) is an activated sludge treatment method and/or a biological denitrification method. 13. Catalyst washing regeneration method, it is characterized in that at least one in the water-insoluble or even insoluble compound of iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals is used as catalyst activity The method of washing and regenerating a supported catalyst for wet oxidation of waste water comprising the following steps: using an acidic aqueous solution as a washing liquid, and for 1 m ³ /hr of the washing liquid, passing air at a ratio of 10 Nm ³ /hr or more, at a temperature above normal temperature contact the catalyst with the wash solution. 14. Catalyst washing regeneration method, it is characterized in that at least one in the water-insoluble or even insoluble compound of iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals is used as catalyst activity The method for washing and regenerating a supported catalyst for the wet oxidation of waste water comprising the following steps: using an alkaline aqueous solution as a washing liquid, and for 1 m ³ /hr of the washing liquid, passing air at a ratio of 10 Nm ³ /hr or more, at a temperature above normal temperature The catalyst and scrubbing liquid are brought into contact at temperature. 15. Catalyst washing regeneration method, it is characterized in that at least one in the water-insoluble or even insoluble compound of iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals is used as catalyst activity The method for washing and regenerating a supported catalyst for wet oxidation of waste water comprising the following steps: (1) using an acidic aqueous solution as a washing liquid, and for 1 m ³ /hr of the washing liquid, passing air at a ratio of 10 Nm ³ /hr or more, at normal temperature The catalyst is contacted with the washing liquid at a temperature above; (2) using an alkaline aqueous solution as the washing liquid, and for the washing liquid 1m ³ /hr, air is passed in at a ratio of 10Nm ³ /hr or more, and the catalyst is used at a temperature above normal temperature. The catalyst is in contact with the wash solution. 16. Catalyst washing regeneration method, it is characterized in that at least one in the water-insoluble or even insoluble compound of iron, cobalt, nickel, magnesium, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and these metals is used as catalyst activity The method of washing and regenerating a supported catalyst for wet oxidation of waste water comprising the following steps: (1) using an alkaline aqueous solution as a washing liquid, and for 1 m ³ /hr of the washing liquid, passing air at a ratio of 10 Nm ³ /hr or more, Contact the catalyst with the washing solution at a temperature above normal temperature; (2) use an acidic aqueous solution as the washing solution, and for 1 m ³ /hr of the washing solution, pass air at a ratio of 10 Nm ³ /hr or more, and use the catalyst at a temperature above normal temperature The catalyst is in contact with the wash solution. 17. A catalyst washing regeneration method in which the catalyst washing waste liquid produced in at least one method of claims 13-16 is subjected to wet oxidation treatment together with waste water. 18. The catalyst washing and regenerating method according to claim 17, the catalyst washing liquid is subjected to coagulation and precipitation treatment, and after removing the metal components in the liquid, it is subjected to wet oxidation treatment together with the waste water.

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