Three-dimensional fibrous ozone catalyst as well as preparation method and application thereof

Abstract

The invention discloses a three-dimensional fibrous ozone catalyst as well as a preparation method and application thereof, and the preparation method comprises the following steps: dipping cleaned and dried steel wool in gel containing active components, and then calcining the steel wool subjected to dipping treatment to obtain the three-dimensional fibrous ozone catalyst. The catalytic activity of the prepared three-dimensional fibrous ozone catalyst is higher than that of a traditional spherical granular catalyst.

Description

Technical Field

[0001] The present invention belongs to the technical field of ozone catalysts, and more specifically, relates to a three-dimensional fibrous ozone catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] The ozone catalytic oxidation technology shows broad application prospects in the treatment of refractory organic wastewater. The addition of an ozone catalyst can not only accelerate the decomposition of ozone but also significantly improve the oxidation ability. However, traditional ozone catalysts have many problems in terms of efficiency and stability.

[0003] At present, common ozone catalysts are mostly in powder or granular form, such as supported metal oxide catalysts, carbon-based catalysts, etc. These catalysts have some limitations in practical applications. First, the powder catalyst has a large specific surface area, which can fully expose catalytic active sites, but it is easy to lose during the reaction process, resulting in difficulties in catalyst recovery and reuse, and increasing the treatment cost. Second, the specific surface area of the granular catalyst is relatively small, which limits its contact area with reactants, thus affecting the catalytic efficiency. At the same time, the stacking of granular catalysts leads to large resistance, high pressure drop, and serious head loss when the fluid passes through.

[0004] In recent years, three-dimensional fibrous materials have attracted extensive attention in the catalyst field and become a research hotspot due to their unique structure and excellent performance. The three-dimensional fibrous structure not only provides a larger specific surface area but also helps the mass transfer and diffusion of reactants, thereby improving the catalytic efficiency. Based on this, developing a three-dimensional fibrous ozone catalyst is of great significance for enhancing the application effect of the ozone catalytic oxidation technology. Summary of the Invention

[0005] The purpose of the present invention is to provide a three-dimensional fibrous ozone catalyst, a preparation method thereof, and an application thereof. The catalytic activity of the three-dimensional fibrous ozone catalyst prepared by the present invention is higher than that of traditional spherical granular catalysts.

[0006] To achieve the above purpose, in the first aspect of the present invention, a preparation method of a three-dimensional fibrous ozone catalyst is provided. The preparation method includes: impregnating the steel wool after cleaning and drying in a gel containing active components, and then calcining the impregnated steel wool to obtain the three-dimensional fibrous ozone catalyst.

[0007] In the present invention, the gel containing active components is preferably a citric acid transition metal salt gel and / or a citric acid rare earth element salt gel; for example, the transition metal is preferably at least one of manganese, iron, cobalt, nickel, copper, and zinc, and the rare earth element is cerium.

[0008] According to the present invention, preferably, the gel containing active components is prepared by a method including the following steps:

[0009] (1) Dissolve nitrate and citric acid in water to obtain a mixed aqueous solution of nitrate and citric acid;

[0010] (2) Dissolve polyethylene glycol in the mixed aqueous solution of nitrate and citric acid, and then heat it to form a gel.

[0011] According to the present invention, preferably, the nitrate includes at least one of manganese nitrate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate, zinc nitrate and cerium nitrate.

[0012] According to the present invention, preferably, in step (1), in the mixed aqueous solution of nitrate and citric acid, the concentration of nitrate is 0.01 - 0.2 mol / L, and the concentration of citric acid is 0.01 - 0.2 mol / L.

[0013] According to the present invention, preferably, in step (2), the weight - average molecular weight (Mw) of the polyethylene glycol is 300 - 1000;

[0014] The molar ratio of polyethylene glycol to nitrate is 1:(1.5 - 3);

[0015] The temperature of the heating is 60 - 100 °C.

[0016] According to the present invention, preferably, the impregnation time is 2 - 5 min;

[0017] The calcination temperature is 350 - 650 °C, and the time is 2 - 3 h.

[0018] According to the present invention, preferably, the cleaning method of steel wool includes the following steps: soak and clean the steel wool alternately with acetone and isopropanol for 1 - 3 times, soak for 3 - 5 min each time, and finally clean with deionized water.

[0019] According to the present invention, preferably, the drying temperature of the steel wool is 60 - 110 °C, and the time is 1 - 2 h.

[0020] The second aspect of the present invention provides a three - dimensional fibrous ozone catalyst prepared by the above preparation method.

[0021] The third aspect of the present invention provides the application of the above three - dimensional fibrous ozone catalyst in sewage treatment.

[0022] The technical solution of the present invention has the following beneficial effects: The catalytic activity of the three - dimensional fibrous ozone catalyst prepared by the present invention is higher than that of the traditional spherical particulate catalyst.

[0023] Other features and advantages of the present invention will be described in detail in the subsequent specific implementation part. Description of the Drawings

[0024] The above and other objects, features, and advantages of the present invention will become more apparent by describing the exemplary embodiments of the present invention in more detail with reference to the accompanying drawings, wherein, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0025] Figure 1 The appearance diagrams of the steel wool before and after loading the active component Co according to Embodiment 2 of the present invention after calcination are shown. Among them, (1) is the appearance diagram of the steel wool without loading the active component Co after calcination; (2) is the appearance diagram of the steel wool loaded with the active component Co after calcination, that is, the appearance diagram of the three-dimensional fibrous ozone catalyst prepared in Embodiment 2. Specific Embodiments

[0026] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0027] The present invention is further illustrated by the following examples:

[0028] In the following examples and comparative examples: the weight-average molecular weight (Mw) of the polyethylene glycol used is 600.

[0029] Example 1

[0030] Cleaning: Take a piece of steel wool of 5*5*5 cm 3 and soak and clean it alternately with acetone and isopropanol 3 times, soak for 5 minutes each time, and finally clean it with deionized water to remove the residual acetone and isopropanol on the steel wool and then set aside.

[0031] Drying: Place the cleaned steel wool in an oven for drying, the oven temperature is 100 °C, and the drying time is 1.5 h.

[0032] Preparation of the gel containing the active component: Dissolve nickel nitrate and citric acid in deionized water to obtain a mixed aqueous solution of nickel nitrate and citric acid; wherein, in the mixed aqueous solution of nickel nitrate and citric acid, the concentration of nickel nitrate is 0.1 mol / L and the concentration of citric acid is 0.1 mol / L; add polyethylene glycol under continuous stirring and dissolve it in the mixed aqueous solution of nickel nitrate and citric acid, and then heat it in an oil bath at 70 °C until a gel (gel containing the active component) is formed; wherein, the molar ratio of polyethylene glycol to nickel nitrate is 1:2.

[0033] Active component loading and calcination: The above-mentioned steel wool after cleaning and drying was impregnated in the above-mentioned gel containing the active component for 3 minutes, and then the impregnated steel wool was placed in a muffle furnace for calcination to obtain the three-dimensional fibrous ozone catalyst (Ni / 3D-Fe); among them, the calcination temperature was 450 °C and the calcination time was 2 hours.

[0034] Example 2

[0035] In this example compared with Example 1, the only difference was that nickel nitrate was replaced with cobalt nitrate, and the others were the same as in Example 1; the three-dimensional fibrous ozone catalyst (Co / 3D-Fe) was obtained.

[0036] Comparative Example 1

[0037] 125 cm 3 Al 2 O 3 balls (activated alumina balls with a diameter of 3-5 mm) were impregnated in the gel containing the active component prepared in Example 1 for 3 minutes, and then the impregnated Al 2 O 3 balls were placed in a muffle furnace for calcination to obtain the ozone catalyst (Ni / Al 2 O 3 ); among them, the calcination temperature was 450 °C and the calcination time was 2 hours.

[0038] Comparative Example 2

[0039] 125 cm 3 Al 2 O 3 balls (activated alumina balls with a diameter of 3-5 mm) were impregnated in the gel containing the active component prepared in Example 2 for 3 minutes, and then the impregnated Al 2 O 3 balls were placed in a muffle furnace for calcination to obtain the ozone catalyst (Co / Al 2 O 3 ); among them, the calcination temperature was 450 °C and the calcination time was 2 hours.

[0040] Test Example

[0041] 500 ml of the biochemical effluent from a pharmaceutical enterprise (COD = 210 mg / L, BOD / COD < 0.2) was placed in a reactor, and the ozone catalyst prepared in the above-mentioned example or comparative example was added (the added volume of the catalyst V = 18 cm 3)。After introducing the ozone-oxygen mixture into the reactor, the reaction was started. The flow rate of the ozone-oxygen mixture was 200 ml / min, and the ozone concentration in the ozone-oxygen mixture was 120 mg / L. After reacting for 30 min, a water sample was taken for COD testing; the specific test results are shown in Table 1. In Table 1, "-" represents the treatment results of only introducing the ozone-oxygen mixture without adding an ozone catalyst according to the above test method. Among them, the COD was determined by referring to the standard method of HJ 828-2017, and the BOD was determined by referring to the standard method of HJ 505-2009.

[0042] Table 1 Data on the catalytic effect of the ozone catalyst

[0043] Catalyst type COD after reaction (mg / L) COD removal rate (%) — 152 27.62 Ni / 3D-Fe (Example 1) 78 62.86 Co / 3D-Fe (Example 2) 66 68.57 <![CDATA[Ni / Al 2 O 3 (Comparative Example 1)]]> 135 35.71 <![CDATA[Co / Al 2 O 3 (Comparative Example 2)]]> 113 46.19

[0044] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for preparing a three-dimensional fibrous ozone catalyst, characterized in that: The preparation method comprises: impregnating the cleaned and dried steel wool into a gel containing active components, and then calcining the impregnated steel wool to obtain the three-dimensional fibrous ozone catalyst.

2. The preparation method according to claim 1, wherein The gel containing the active ingredient is prepared by a method comprising the following steps: (1) dissolving nitrate and citric acid in water to obtain a mixed aqueous solution of nitrate and citric acid; (2) Dissolving polyethylene glycol in the mixed aqueous solution of nitrate and citric acid, and then heating the solution to form a gel.

3. The preparation method according to claim 2, wherein The nitrate comprises at least one of manganese nitrate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate, zinc nitrate and cerium nitrate.

4. The preparation method according to claim 2, wherein In step (1), in the mixed aqueous solution of nitrate and citric acid, the concentration of nitrate is 0.01-0.2 mol / L, and the concentration of citric acid is 0.01-0.2 mol / L.

5. The preparation method according to claim 2, wherein: In step (2), the weight average molecular weight of the polyethylene glycol is 300-1000; The molar ratio of polyethylene glycol to nitrate is 1:(1.5-3); The heating temperature is 60-100°C.

6. The preparation method according to claim 1, wherein The dipping time is 2-5 min; The calcination temperature is 350-650° C. and the calcination time is 2-3 hours.

7. The preparation method according to claim 1, wherein The cleaning method of steel wool comprises the following steps: soaking the steel wool in acetone and isopropyl alcohol alternately for 1-3 times, soaking for 3-5 minutes each time, and finally washing with deionized water.

8. The preparation method according to claim 1, wherein The drying temperature of steel wool is 60-110℃ and the drying time is 1-2h.

9. A three-dimensional fibrous ozone catalyst prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the three-dimensional fibrous ozone catalyst according to claim 9 in sewage treatment.

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