Catalytic ozonation catalyst for treating radioactive waste liquid and preparation method of catalytic ozonation catalyst

Abstract

The invention relates to a catalytic ozonation catalyst for treating radioactive waste liquid and a preparation method of the catalytic ozonation catalyst. The preparation method comprises the following steps: preparing porous biochar, and carrying out hydrothermal treatment on the porous biochar and a hydrophilic reagent to prepare a hydrophilic porous biochar substrate; adding a titanium source into a hydrofluoric acid solution with a set concentration, and uniformly stirring to form a titanium-containing stock solution; and adding the hydrophilic porous biological carbon substrate into the titanium-containing stock solution, continuously stirring for a certain time, carrying out a hydrothermal reaction under high-temperature and high-pressure conditions, cleaning the obtained product to be neutral, and drying to obtain the catalytic ozonation catalyst. According to the present invention, the titanium oxide is adopted as the catalytic activity reagent, the hydrophilic porous biological carbon substrate is adopted as the carrier, the in-situ synthesis ozone catalytic oxidation catalyst is performed through the hydrothermal method, and the in-situ synthesis ozone catalytic oxidation catalyst has characteristics of significant synergistic adsorption effect, high ozone loading capacity, concentrated catalytic reduction after adsorption of the organic matter, and significant catalysis efficiency improving.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear waste liquid treatment, and in particular relates to an ozone catalytic oxidation catalyst for treating radioactive waste liquid and a preparation method thereof. Background Art

[0002] With the continuous development of the nuclear industry, a certain amount of radioactive decontamination waste liquid is generated during the nuclear fuel cycle, at various stages after the operation of nuclear facilities, and during the operation of nuclear technology units. At present, all countries classify radioactive decontamination waste liquid as difficult-to-treat organic waste. The treatment of decontamination waste liquid plays a decisive role in the sustainable development of industry and is also of great significance to improving the ecological environment.

[0003] The commonly used methods for treating organic matter in radioactive decontamination waste liquid mainly include: biodegradation, adsorption, catalytic oxidation and some advanced oxidation treatment methods. Methods such as biodegradation, physical adsorption and catalytic oxidation have disadvantages such as incomplete treatment and many intermediate products. Fenton oxidation and ozone oxidation are advanced oxidation treatment methods that can oxidize and decompose many difficult-to-degrade organic matter. In recent years, they have been widely studied and applied in the field of waste liquid organic matter treatment. However, when treating organic matter in radioactive decontamination waste liquid, ozone oxidation treatment alone will produce a large amount of diazo compounds in the early stage of oxidation. The reaction system is complex and there are many difficult-to-degrade intermediates.

[0004] Common ozone catalysts on the market mainly use the catalytic effect of solid metals, metal oxides or metals or metal oxides loaded on carriers. However, the carrier is generally based on high-strength silicon-aluminum composites, which have relatively high density, high consumption, smaller pore size than carbon-based, and weaker adsorption performance. For organic matter in wastewater, the density is relatively large, and adsorption contact can only be carried out during the stirring process, which is time-consuming and labor-intensive.

[0005] In order to improve the problems existing in the application of ozone catalysts, patent CN113198462A discloses an ozone catalytic oxidation catalyst and its preparation method and application, provides an ozone catalytic oxidation catalyst for removing volatile organic compounds (VOCs) in a gas environment and its preparation method and application, relates to the field of air pollution control, uses aluminum oxide as a carrier and manganese salt as an active component, and the ozone catalytic oxidation catalyst can not only remove toluene and a mixed gas of toluene and benzene at room temperature, but also has a removal rate of more than 80% for a two-component mixed gas. However, the invention is only applied to volatile organic compounds in a closed room, and cannot remove radioactive organic compounds in a liquid phase.

[0006] Patent CN110052268A discloses an ozone catalytic oxidation catalyst and its preparation method, which mainly relates to the field of wastewater treatment and catalyst preparation technology. Activated carbon is used as a substrate and impregnated in Fe(NO3)3 or Mn(NO3)2 or Fe(NO3)3-Mn(NO3)2 mixed solution to synthesize a composite ozone catalytic oxidation catalyst, which is applied to the treatment of phenol-containing, cyanide-containing and printing and dyeing wastewater. However, the single-morphology ozone catalytic oxidation catalyst has defects such as agglomeration and coating of multiple metal and non-metal substances, which leads to a decrease in the effect of the catalyst, especially in the environment with high water content, the removal rate is poor.

[0007] Patent CN106215946A discloses an ozone catalyst for sewage treatment and a preparation method thereof, wherein an inorganic material with catalytic activity is firmly coated on the surface of diatomite particles, and the catalyst is prepared by calcining and molding at one time, which has the advantages of simple operation steps, high preparation efficiency, and no waste of raw materials. However, the invention uses diatomite particles as a carrier, which is relatively costly and has unsatisfactory chemical stability. The content of iron, calcium, etc. in diatomite is relatively high and exists in a separated state, so its dissolution rate is high, which is not conducive to the synthesis and long-term use of the catalyst.

[0008] Therefore, it is necessary to develop a new type of ozone oxidation catalyst that can be effectively used in the catalytic disposal of decontamination agents in radioactive waste liquid; it can not only effectively reduce the radioactive content to below the safety standard and ensure the life safety of catalytic operators; it should also meet the requirements of easy recovery and disposal of the catalyst after decontamination without causing secondary pollution. Summary of the invention

[0009] The purpose of the present invention is to provide an ozone catalytic oxidation catalyst for treating radioactive waste liquid and a preparation method thereof. By constructing a multi-morphological amphoteric oxide TiO2 on a hydrophilic biocarbon substrate prepared on biological materials with different structures, it has high surface area adhesion, self-release, sustained release, adsorption and activation synergistic effects and multi-phase ozone technology. It also has the advantages of simple synthesis process operation, low cost, high efficiency and environmental friendliness.

[0010] To achieve the above purpose, the technical solution adopted by the present invention is: a method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid, the method comprising the following steps:

[0011] S1. Preparing porous biochar: grinding the high-temperature activator and the biomass powder in a predetermined ratio to make them uniformly mixed, then heating to a high-temperature pyrolysis temperature at a set heating rate under the protection of an inert gas, keeping at the high-temperature pyrolysis temperature for a certain period of time, and then naturally cooling to room temperature, neutralizing the taken out pyrolysis product with a neutralizing agent to neutrality, and then washing it with deionized water, and drying it in an oven to prepare the porous biochar;

[0012] S2, preparing a hydrophilic porous biocarbon substrate: mixing the porous biocarbon with a hydrophilic reagent, and performing a hydrothermal treatment to prepare the hydrophilic porous biocarbon substrate;

[0013] S3, preparing a titanium-containing stock solution: preparing a hydrofluoric acid solution of a set concentration, adding a titanium source thereto, and stirring evenly to form the titanium-containing stock solution;

[0014] S4. Preparation of ozone catalytic oxidation catalyst: adding the hydrophilic porous biocarbon substrate to the titanium-containing stock solution and continuing to stir for a certain period of time, performing a hydrothermal reaction under high temperature and high pressure conditions, washing the obtained product to neutrality, and drying to obtain the ozone catalytic oxidation catalyst.

[0015] Furthermore, the preparation method of the biomass powder is as follows: washing, drying, crushing and passing the biomass through a 100-200 mesh sieve to obtain the biomass powder;

[0016] The biomass is selected from one or more of corn stalks, rice husks, kapok or hemp stalks.

[0017] Furthermore, the high temperature activator is selected from one or a combination of NaOH, KOH, NaHCO3 or KCl.

[0018] Furthermore, the mass ratio of the biomass powder to the high-temperature activator is 1:2 to 2:1.

[0019] Furthermore, the inert gas is nitrogen and / or argon.

[0020] Further, in step S1, the set heating rate is 5 to 10°C / min;

[0021] The high temperature pyrolysis temperature is 500-800° C., and the high temperature pyrolysis temperature is maintained for 0.5-2 hours.

[0022] Furthermore, the neutralizing agent is selected from one or a combination of hydrochloric acid, nitric acid and sulfuric acid.

[0023] Furthermore, in step S2, the hydrophilic reagent is selected from one or a combination of ammonium persulfate, sulfuric acid or nitric acid.

[0024] Furthermore, in step S2, the hydrothermal treatment method is: after mixing the porous biochar with a hydrophilic reagent, hydrothermally treat it at 60-80° C. and 0.1-3 MPa for 3-4 hours to obtain the hydrophilic porous biochar substrate.

[0025] Furthermore, the titanium source is tetrabutyl titanate and / or isopropyl titanate.

[0026] Furthermore, the mass percentage of tetrabutyl titanate in the titanium-containing stock solution is 1-3%.

[0027] Furthermore, in step S4, the hydrophilic porous biocarbon substrate is added with the titanium-containing stock solution, and after continuing to stir for 30 to 40 minutes, it is transferred to a high-temperature and high-pressure reactor lined with polytetrafluoroethylene and placed in an oven for hydrothermal reaction.

[0028] Furthermore, in step S4, the hydrothermal reaction is carried out under the conditions of 160-180° C. and 0.1-3 MPa for 10-12 hours.

[0029] The present invention also provides an ozone catalytic oxidation catalyst for treating radioactive waste liquid, which is prepared by the preparation method of the ozone catalytic oxidation catalyst for treating radioactive waste liquid. The ozone catalytic oxidation catalyst includes a carbon substrate and a metal active component, the carbon substrate is a hydrophilic porous bio-carbon substrate, the metal active component is titanium dioxide, and the titanium dioxide is carried on the hydrophilic porous bio-carbon substrate.

[0030] Furthermore, the mass percentage of the hydrophilic porous biocarbon substrate in the ozone catalytic oxidation catalyst is 5 to 85%.

[0031] The beneficial effects of the present invention are: using the ozone catalytic oxidation catalyst and preparation method thereof for treating radioactive waste liquid provided by the present invention, by preparing porous biochar, the porous biochar and a hydrophilic reagent are subjected to hydrothermal treatment to prepare a hydrophilic porous biocarbon substrate; adding a titanium source to a hydrofluoric acid solution of a set concentration, stirring evenly to form a titanium-containing stock solution; adding the hydrophilic porous biocarbon substrate to the titanium-containing stock solution and continuing to stir for a certain period of time, hydrothermally reacting under high temperature and high pressure conditions, washing the obtained product to neutrality, and drying to obtain an ozone catalytic oxidation catalyst. The present invention uses titanium oxide as a catalytically active reagent, and a hydrophilic porous biocarbon substrate as a carrier, and synthesizes an ozone catalytic oxidation catalyst in situ by a hydrothermal method. Compared with common activated carbon, the hydrophilic porous biocarbon substrate has different loose porous, tubular and other microstructures, and the composite processed catalyst TiO2 has an obvious synergistic adsorption effect, a high loading capacity for ozone, and can concentrate catalytic reduction after adsorbing organic matter TBP / OK, significantly improving the catalytic efficiency. The specific beneficial effects of the present invention are mainly reflected in:

[0032] (1) The use of multiphase ozone technology combined with three-dimensional framework synthesis technology greatly increases the number and distribution of micropores in the catalyst substrate under high temperature and high pressure conditions, resulting in a higher specific surface area and stronger adsorption performance. It can enrich organic matter in radioactive waste liquid on the surface and catalyze ozone on the catalyst surface, which can increase the ozone oxidation efficiency by more than 30%;

[0033] (2) The ozone catalytic oxidation catalyst is combined by chemical bonds and hydrogen bonds, which avoids the loss during the adsorption process and increases the service life; moreover, the ozone catalytic oxidation catalyst has a self-release effect. Under ultraviolet light catalysis, the excited electrons can combine with oxygen in water to generate superoxide anions, weakening the oxygen-oxygen bonds between oxygen atoms, and can effectively oxidize the interfacial organic matter in TBP / OK waste liquid, thereby saving more than 10% of the ozone input under the same removal rate;

[0034] (3) The prepared ozone catalytic oxidation catalyst has high catalytic activity, the active component and the carrier are firmly combined, the catalytic activity always maintains high stability when treating waste liquid for a long time, the organic matter removal rate and the effective service life of the catalyst are significantly improved, the preparation process is simple, the raw materials are extensive, the cost is appropriate, and it is suitable for industrial production and application;

[0035] (4) The steps in the method are scientific and reasonable, complement each other, and have strong operability. The adsorbent can be quickly prepared and the radioactive organic pollutants can be effectively decomposed. The method has small environmental pollution, low cost, high decontamination efficiency, simplified processing technology, saved reagent consumption, and significant effect, and is worthy of promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic flow chart of a method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be further clearly and completely described below in conjunction with the drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] The catalysis of the decontamination agent in radioactive waste liquid should meet specific requirements, mainly including: (1) application to waste liquid containing radioactive organic matter; (2) the sum of the total hardness and alkalinity in the waste liquid is less than 1500 mg / L; (3) the content of suspended matter in the waste liquid is less than 50 mg / L.

[0039] The main advantages of ozone catalyst as a reaction intermediate medium are as follows: (1) less secondary emissions, environmentally friendly and non-toxic; (2) stable and safe performance; (3) low operating costs and low economic costs; (4) high mechanical strength; (5) less by-products and no scaling; (6) adaptable to a wide pH range and high activity; (7) large ozone adsorption loading capacity; (8) high catalytic efficiency.

[0040] like Figure 1 As shown, this embodiment provides a method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid, the method comprising the following steps:

[0041] S1. Preparation of porous biochar: Grind the high-temperature activator and biomass powder in a predetermined ratio to make them uniformly mixed, then heat the mixture to a high-temperature pyrolysis temperature at a set heating rate under the protection of an inert gas, keep the mixture at the high-temperature pyrolysis temperature for a certain period of time, and then naturally cool the mixture to room temperature. The pyrolysis product taken out is neutralized to neutrality with a certain amount of a neutralizing agent, and then fully washed with deionized water and dried in an oven to prepare porous biochar with a relatively high surface area.

[0042] Specifically, the preparation method of the biomass powder is as follows: washing, drying, crushing and passing the biomass through a 100-200 mesh sieve to obtain the biomass powder. The biomass is selected from one or more of corn stalks, rice husks, kapok or hemp stalks.

[0043] Optionally, the high temperature activator is selected from one or a combination of NaOH, KOH, NaHCO3 or KCl.

[0044] Specifically, the mass ratio of the biomass powder to the high-temperature activator is 1:2 to 2:1.

[0045] Optionally, the inert gas is nitrogen or argon, or a combination of more than one of them.

[0046] Optionally, in step S1, the set heating rate is 5 to 10°C / min.

[0047] Optionally, the high-temperature pyrolysis temperature is 500-800° C. and is maintained at the high-temperature pyrolysis temperature for 0.5-2 hours.

[0048] Optionally, the neutralizing agent is selected from hydrochloric acid, nitric acid, sulfuric acid, etc., or a combination of several of them.

[0049] S2, preparing a hydrophilic porous biocarbon substrate: mixing the porous biocarbon with a certain concentration of a hydrophilic reagent, and preparing a hydrophilic porous biocarbon substrate HBC after hydrothermal treatment;

[0050] Optionally, in step S2, the hydrophilic reagent is selected from one or a combination of ammonium persulfate, sulfuric acid or nitric acid.

[0051] Optionally, in step S2, the porous biochar and the hydrophilic agent are mixed in a mass ratio of 1:1 to 5:1. The mass percentage of the hydrophilic agent is 0.5 to 20%.

[0052] Specifically, the hydrothermal treatment method is: after mixing the porous biochar with a hydrophilic reagent, hydrothermally treat it at 60-80° C. and 0.1-3 MPa for 3-4 hours to obtain the hydrophilic porous biochar substrate.

[0053] S3, preparing a titanium-containing stock solution: preparing a hydrofluoric acid solution of a set concentration, adding a titanium source thereto, and stirring evenly to form the titanium-containing stock solution;

[0054] Optionally, the titanium source is one or a combination of tetrabutyl titanate, isopropyl titanate, etc.

[0055] Optionally, the mass percentage of hydrofluoric acid in the hydrofluoric acid solution is 1-5%.

[0056] Specifically, step S3 includes the following specific steps: accurately pipetting hydrofluoric acid and adding it into deionized distilled water, then adding tetrabutyl titanate and / or isopropyl titanate dropwise, and stirring for 60 to 70 minutes to form the titanium-containing stock solution.

[0057] In a specific embodiment, the mass percentage of tetrabutyl titanate in the titanium-containing stock solution is 1-3%.

[0058] S4. Preparation of ozone catalytic oxidation catalyst: adding the hydrophilic porous biocarbon substrate to the titanium-containing stock solution and continuing to stir for a certain period of time, performing in-situ synthesis under high temperature and high pressure conditions, washing the obtained product to neutrality, and drying to obtain the ozone catalytic oxidation catalyst.

[0059] Specifically, in step S4, the hydrophilic porous biocarbon substrate is added with the titanium-containing stock solution, and the stirring is continued for 30 to 40 minutes until tetrabutyl titanate (TBT) is fully hydrolyzed, and then transferred to a high-temperature and high-pressure reactor lined with polytetrafluoroethylene, and placed in an oven for hydrothermal reaction, and TiO2 is grown in situ on the hydrophilic porous biocarbon substrate. Among them, the hydrophilic functional group can strengthen the riveting (forming chemical bonds or hydrogen bonds) between the activated carbon carrier and the catalyst TiO2, reduce exudation, and has unique surface super-hydrophilicity, adsorption and large specific surface area. When the active center density is constant, the larger the surface area, the more highly active OH is adsorbed, thereby improving the catalytic oxidation efficiency.

[0060] Optionally, the hydrothermal reaction is carried out under the conditions of 160-180° C. and 0.1-3 MPa for 10-12 hours.

[0061] The preparation method of the ozone catalytic oxidation catalyst for treating radioactive waste liquid provided in this embodiment adopts titanium oxide as a carrier (catalytically active reagent), and uses a hydrophilic porous biocarbon substrate as a carrier to synthesize the ozone catalytic oxidation catalyst in situ by a hydrothermal method; compared with common activated carbon, the hydrophilic porous biocarbon substrate has different loose porous, tubular and other microstructures, and the composite processed catalyst TiO2 has an obvious synergistic adsorption effect, a high loading capacity for ozone, and can concentrate catalytic reduction after adsorption of organic matter TBP / OK, significantly improving the catalytic efficiency. The method provided in this embodiment adopts multiphase ozone technology, combined with stereostructure synthesis technology, greatly increases the number and distribution of micropores of the catalyst substrate under high temperature and high pressure conditions, has a higher specific surface area and stronger adsorption performance, can enrich the organic matter of radioactive waste liquid on the surface, and catalyze ozone on the catalyst surface, which can improve the ozone oxidation efficiency by more than 30%.

[0062] The ozone catalytic oxidation catalyst prepared in this embodiment is combined by chemical bonds, which avoids the loss of energy during the catalytic process and increases the service life. Moreover, the ozone catalytic oxidation catalyst has a self-release effect. Under ultraviolet light catalysis, the excited electrons can combine with oxygen in water to generate superoxide anions, weakening the oxygen-oxygen bonds between oxygen atoms, and can effectively oxidize the interfacial organic matter in TBP / OK waste liquid, thereby saving more than 10% of the ozone input under the same removal rate.

[0063] In general, the ozone catalytic oxidation catalyst prepared in this embodiment has high catalytic activity, the active component and the carrier are firmly combined, the catalytic activity always maintains high stability in the case of long-term waste liquid treatment, the organic matter removal rate and the effective service life of the catalyst are significantly improved, the preparation process is simple, the raw materials are extensive, the cost is appropriate, and it is suitable for industrial production and application. The steps in the method are scientific and reasonable, complementary, and highly operable. The adsorbent can be quickly configured, and the radioactive organic pollutants can be effectively decomposed. The environmental pollution is small, the cost is low, the decontamination efficiency is high, the processing technology is simplified, the reagent consumption is saved, the effect is significant, and it is worthy of promotion and application.

[0064] This embodiment also provides an ozone catalytic oxidation catalyst for treating radioactive waste liquid, which is prepared by the above-mentioned preparation method of the ozone catalytic oxidation catalyst for treating radioactive waste liquid. The ozone catalytic oxidation catalyst includes a carbon substrate and a metal active component, the carbon substrate is a hydrophilic porous bio-carbon substrate, the metal active component is titanium dioxide, and the titanium dioxide is carried on the hydrophilic porous bio-carbon substrate.

[0065] Optionally, the mass percentage of the hydrophilic porous biocarbon substrate in the ozone catalytic oxidation catalyst is 5 to 85%.

[0066] Specifically, the ozone catalytic oxidation catalyst has a self-release effect, saving more than 10% of the ozone input.

[0067] The hydrophilic porous biocarbon substrate is based on porous biocarbon with abundant macropores and pore size distribution. The hydrophilic functional groups can strengthen the riveting (forming chemical bonds or hydrogen bonds) between the activated carbon carrier and the catalyst TiO2, reduce seepage, and have unique surface superhydrophilicity, adsorption and large specific surface area. When the active center density is constant, the larger the surface area, the more highly active OH is adsorbed, thereby increasing the ozone catalytic oxidation efficiency by more than 10%.

[0068] The specific implementation modes of the present invention are further described below through examples.

[0069] Example 1: Preparation of ozone catalytic oxidation catalyst A using the above-mentioned preparation method of ozone catalytic oxidation catalyst for treating radioactive waste liquid

[0070] S11. Preparation of hydrophilic porous biochar substrate: Wash and dry the biomass corn stalks and crush them through a 100-mesh sieve. Grind the high-temperature activator NaOH and the corn stalk powder in a mass ratio of 1:1 to make them evenly mixed. Then, heat the mixture to a high-temperature pyrolysis temperature of 600°C at a heating rate of 5°C / min under nitrogen protection, keep it at the pyrolysis temperature for 1 hour, and then naturally cool it to room temperature. The pyrolysis product taken out is neutralized to neutrality with a certain amount of neutralizing agent 0.1 mol / L hydrochloric acid, and then washed thoroughly with deionized water and dried in an oven at 60°C to prepare porous biochar with a high surface area. The porous biochar is mixed with a certain concentration of hydrophilic reagent ammonium persulfate, and hydrothermally treated at 60°C and 0.12MPa for 3 hours to prepare a hydrophilic porous biochar substrate HBC;

[0071] S12, preparation of ozone catalytic oxidation catalyst A: accurately pipette 0.2mL of hydrofluoric acid into 30mL of deionized distilled water, then add 1mL of tetrabutyl titanate (TBT) dropwise, stir for 60min to form a titanium-containing stock solution, add a certain mass of hydrophilic porous biocarbon substrate, continue stirring for 30min, transfer TBT to a high-temperature and high-pressure reactor lined with polytetrafluoroethylene after sufficient hydrolysis, and place it in an oven for hydrothermal reaction, the reaction conditions are 160℃, 1.5MPa, and reaction for 12h. After cooling to room temperature, the reaction product is washed several times with distilled water until neutral, and dried in an oven at 60℃ to obtain ozone catalytic oxidation catalyst A (HBC / TiO2).

[0072] The mass percentage of the hydrophilic porous biocarbon substrate in the ozone catalytic oxidation catalyst is 5-85%. The composite materials prepared by adding different masses of HBC in Example 1 are marked as 5% HBC / Fe2O3 / TiO2, 10% HBC / Fe2O3 / TiO2, 15% HBC / Fe2O3 / TiO2, 20% HBC / Fe2O3 / TiO2, 30% HBC / Fe2O3 / TiO2, 50% HBC / Fe2O3 / TiO2, 70% HBC / Fe2O3 / TiO2, and 85% HBC / Fe2O3 / TiO2.

[0073] Example 2: Performance of HEDP substrate disinfectant treated by catalytic ozone oxidation using ozone catalytic oxidation catalyst A

[0074] The main purpose of this Example 2 is to verify the performance of the ozone catalytic oxidation catalyst A in catalytic effect on the ozone oxidation of HEDP-based detergent decontamination wastewater.

[0075] Among them, the dosage of ozone catalytic oxidation catalyst A is 1g / L, the power of the ozone generator is 3.1-3.2KW, the ozone concentration is 100mg / L; the initial concentration of formaldehyde is 0.24mg / L, and the initial concentration of COD is 190.9mg / L. According to the above ratio, 1.0m 3 The catalytic oxidation time is 1 hour, after which sampling is performed for online analysis to detect the treatment effect of the wastewater. The experimental data and treatment effect are shown in Table 1 below:

[0076] Table 1 Catalytic effect of ozone catalytic oxidation catalyst A on ozone oxidation of HEDP-based decontamination agent decontamination wastewater

[0077]

[0078] After testing, when the sewage treatment volume reaches 1.0m 3 / h, when the initial formaldehyde concentration was 0.24 mg / L and the initial COD concentration was 190.9 mg / L, the COD content after treatment was lower than 120 mg / L and the formaldehyde concentration was less than 2.0 mg / L.

[0079] Example 3: Preparation of ozone catalytic oxidation catalyst B using the above-mentioned preparation method of ozone catalytic oxidation catalyst for treating radioactive waste liquid

[0080] S31. Preparation of hydrophilic porous biocarbon substrate: Wash and dry the biomass corn stalks and crush them through a 100-mesh sieve. Grind the high-temperature activator NaOH and the corn stalk powder in a mass ratio of 1:1 to make them evenly mixed. Then, heat the mixture to a high-temperature pyrolysis temperature of 600°C at a heating rate of 5°C / min under nitrogen protection, keep it at the pyrolysis temperature for 1 hour, and then naturally cool it to room temperature. The pyrolysis product taken out is neutralized to neutrality with a certain amount of neutralizing agent 0.1mol / L hydrochloric acid, and then washed thoroughly with deionized water and dried in an oven at 60°C to prepare porous biocarbon with a high surface area. The porous biocarbon is mixed with a certain concentration of hydrophilic reagent ammonium persulfate, and hydrothermally treated at 60°C and 0.12MPa for 3 hours to prepare a hydrophilic porous biocarbon substrate HBC;

[0081] S32, preparation of ozone catalytic oxidation catalyst B: accurately pipette 0.2mL of hydrofluoric acid into 30mL of deionized distilled water, then add 1mL of tetrabutyl titanate (TBT) dropwise, stir for 60min to form a titanium-containing stock solution, add a certain mass of hydrophilic porous biocarbon substrate, continue stirring for 30min, transfer TBT to a high-temperature and high-pressure reactor lined with polytetrafluoroethylene after sufficient hydrolysis, and place it in an oven for hydrothermal reaction, the reaction conditions are 160℃, 2MPa, and reaction for 12h. After cooling to room temperature, the reaction product is washed several times with distilled water until neutral, and dried in an oven at 60℃ to obtain ozone catalytic oxidation catalyst B (HBC / TiO2).

[0082] The mass percentage of the hydrophilic porous biocarbon substrate in the ozone catalytic oxidation catalyst is 5-85%. The composite materials prepared by adding different masses of HBC in Example 1 are marked as 5% HBC / Fe2O3 / TiO2, 10% HBC / Fe2O3 / TiO2, 15% HBC / Fe2O3 / TiO2, 20% HBC / Fe2O3 / TiO2, 30% HBC / Fe2O3 / TiO2, 50% HBC / Fe2O3 / TiO2, 70% HBC / Fe2O3 / TiO2, and 85% HBC / Fe2O3 / TiO2.

[0083] Example 4: Performance of ozone catalytic oxidation catalyst B in catalytic ozone oxidation treatment of disinfectant

[0084] The main purpose of this Example 4 is to verify the performance of the ozone catalytic oxidation catalyst B on the catalytic effect of ozone oxidation-based cleaning wastewater.

[0085] Among them, the dosage of ozone catalytic oxidation catalyst B is 1g / L, the power of the ozone generator is 3.1-3.2KW, the ozone concentration is 100mg / L; the initial concentration of formaldehyde is 0.19mg / L, and the initial concentration of COD is 174.9mg / L. According to the above ratio, 1.0m 3 The catalytic oxidation time is 1 hour, after which sampling is performed for online analysis to detect the treatment effect of the wastewater. The experimental data and treatment effect are shown in Table 2 below:

[0086] Table 2 Catalytic effect of ozone catalytic oxidation catalyst B on ozone oxidation of decontamination wastewater

[0087]

[0088]

[0089] After testing, when the sewage treatment volume reaches 1.0m 3 / h, when the initial formaldehyde concentration was 0.19 mg / L and the initial COD concentration was 174.9 mg / L, the COD content after treatment was lower than 120 mg / L and the formaldehyde concentration was less than 2.0 mg / L.

[0090] The method described in the present invention is not limited to the specific embodiments described. The above embodiments are only examples of the present invention. The present invention can also be implemented in other specific ways or other specific forms without departing from the gist or essential features of the present invention. Therefore, the described embodiments should be regarded as illustrative rather than restrictive in any respect. The scope of the present invention should be described by the attached claims, and any changes equivalent to the intent and scope of the claims should also be included in the scope of the present invention.

Claims

1. A method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid, characterized in that: The method comprises the following steps: S1. Preparing porous biochar: grinding the high-temperature activator and the biomass powder in a predetermined ratio to make them uniformly mixed, then heating to a high-temperature pyrolysis temperature at a set heating rate under the protection of an inert gas, keeping at the high-temperature pyrolysis temperature for a certain period of time, and then naturally cooling to room temperature, neutralizing the taken out pyrolysis product with a neutralizing agent to neutrality, and then washing it with deionized water, and drying it in an oven to prepare the porous biochar; S2, preparing a hydrophilic porous biocarbon substrate: mixing the porous biocarbon with a hydrophilic reagent, and performing a hydrothermal treatment to prepare the hydrophilic porous biocarbon substrate; S3, preparing a titanium-containing stock solution: preparing a hydrofluoric acid solution of a set concentration, adding a titanium source thereto, and stirring evenly to form the titanium-containing stock solution; S4. Preparation of ozone catalytic oxidation catalyst: adding the hydrophilic porous biocarbon substrate to the titanium-containing stock solution and continuing to stir for a certain period of time, performing a hydrothermal reaction under high temperature and high pressure conditions, washing the obtained product to neutrality, and drying to obtain the ozone catalytic oxidation catalyst.

2. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: The preparation method of the biomass powder is as follows: washing, drying, crushing and passing the biomass through a 100-200 mesh sieve to obtain the biomass powder; The biomass is selected from one or more of corn stalks, rice husks, kapok or hemp stalks.

3. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: The high temperature activator is selected from one or a combination of NaOH, KOH, NaHCO3 or KCl.

4. The method for preparing an ozone oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: The mass ratio of the biomass powder to the high-temperature activator is 1:2 to 2:

1.

5. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: The inert gas is nitrogen and / or argon.

6. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: In step S1, the set heating rate is 5-10°C / min; The high temperature pyrolysis temperature is 500-800° C., and the high temperature pyrolysis temperature is maintained for 0.5-2 hours.

7. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: The neutralizing agent is selected from hydrochloric acid, nitric acid, sulfuric acid or a combination of several thereof.

8. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: In step S2, the hydrophilic reagent is selected from one or a combination of ammonium persulfate, sulfuric acid or nitric acid.

9. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: In step S2, the hydrothermal treatment method is: after mixing the porous biochar with a hydrophilic reagent, hydrothermally treat it at 60-80° C. and 0.1-3 MPa for 3-4 hours to obtain the hydrophilic porous biochar substrate.

10. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: The titanium source is tetrabutyl titanate and / or isopropyl titanate.

11. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 10, characterized in that: The mass percentage of tetrabutyl titanate in the titanium-containing stock solution is 1-3%.

12. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: In step S4, the hydrophilic porous biocarbon substrate is added with the titanium-containing stock solution, and after continuing to stir for 30 to 40 minutes, it is transferred to a high-temperature and high-pressure reactor lined with polytetrafluoroethylene and placed in an oven for hydrothermal reaction.

13. The method for preparing an ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 1, characterized in that: In step S4, the hydrothermal reaction is carried out under the conditions of 160-180° C. and 0.1-3 MPa for 10-12 hours.

14. An ozone catalytic oxidation catalyst for treating radioactive waste liquid, characterized in that: The ozone catalytic oxidation catalyst for treating radioactive waste liquid is prepared by the preparation method of any one of claims 1 to 13, wherein the ozone catalytic oxidation catalyst comprises a carbon substrate and a metal active component, wherein the carbon substrate is a hydrophilic porous bio-carbon substrate, and the metal active component is titanium dioxide, and the titanium dioxide is carried on the hydrophilic porous bio-carbon substrate.

15. The ozone catalytic oxidation catalyst for treating radioactive waste liquid according to claim 14, characterized in that: The mass percentage of the hydrophilic porous biocarbon substrate in the ozone catalytic oxidation catalyst is 5 to 85%.

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