CN115779976A

CN115779976A - Modified ozonization catalyst and preparation method and application thereof

Info

Publication number: CN115779976A
Application number: CN202211642005.5A
Authority: CN
Inventors: 陈徐; 文英杰; 陆之毅; 王越楚; 陈乐亦
Original assignee: Ningbo Institute of Material Technology and Engineering of CAS
Current assignee: Ningbo Institute of Material Technology and Engineering of CAS
Priority date: 2022-12-20
Filing date: 2022-12-20
Publication date: 2023-03-14
Anticipated expiration: 2042-12-20
Also published as: CN115779976B

Abstract

The invention discloses a modified ozonization catalyst and a preparation method and application thereof. The preparation method comprises the following steps: mixing a hydrophobic filler with a hydrophobic coating to form a hydrophobic modified dispersion; and placing the ozonization catalyst in the hydrophobic modified dispersion liquid for impregnation treatment, and then calcining to prepare a modified ozonization catalyst; wherein, the hydrophobic filler comprises any one or the combination of more than two of silicon dioxide, silicon nitride and silicon carbide. The preparation method of the modified ozonization catalyst provided by the invention utilizes the hydrophobic material layer to coat the surface of the spherical catalyst, can increase the ozone wettability on the surface of the catalyst and the surface area of the surface of the catalyst, and can be better contacted with ozone, thereby being beneficial to more efficiently generating hydroxyl free radicals, improving the reaction speed and further improving the service performance of the catalyst in the catalytic ozonization.

Description

Modified ozonization catalyst and preparation method and application thereof

Technical Field

The invention belongs to the technical field of sewage treatment, and particularly relates to a modified ozonization catalyst, and a preparation method and application thereof.

Background

Catalytic ozonation is increasingly used as an advanced oxidation technology in research applications for sewage treatment, especially in intractable industrial sewage. The catalytic ozonation technology utilizes a catalyst to catalyze ozone to generate hydroxyl radicals with oxidability stronger than that of the ozone, and the hydroxyl radicals are used for oxidizing and decomposing reductive organic matters in the sewage, so that the aim of reducing COD (chemical oxygen demand) of the sewage is fulfilled, and the catalytic ozonation technology has a good application prospect in advanced treatment of the sewage.

At present, a carrier type catalyst is generally used, catalytic active metal oxide is loaded on a porous carrier to form a reaction surface, and the active metal oxide catalyzes ozone to generate strong oxidizing hydroxyl free radicals to decompose organic matters in sewage. The catalysts mainly comprise aluminosilicate, perovskite, charcoal and the like, but the catalysts are not sufficiently contacted with ozone, cannot achieve a high-degree infiltration effect, have a slow reaction speed for generating hydroxyl radicals, and further cannot better perform advanced oxidation treatment of catalytic ozonation on sewage;

therefore, the universal preparation method is developed, the contact between ozone and the catalyst is improved by improving the wettability of the ozone, the reaction speed is improved, and the expression of the catalyst in the catalytic ozonation is further improved.

Disclosure of Invention

The invention mainly aims to provide a modified ozonization catalyst, a preparation method and application thereof, so as to overcome the defects of the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:

the embodiment of the invention provides a preparation method of a modified ozonization catalyst, which comprises the following steps:

mixing a hydrophobic filler with a hydrophobic coating to form a hydrophobic modified dispersion;

and placing the ozonization catalyst in the hydrophobic modified dispersion liquid for dipping treatment, and then calcining to prepare a modified ozonization catalyst;

wherein, the hydrophobic filler comprises any one or the combination of more than two of silicon dioxide, silicon nitride and silicon carbide.

The embodiment of the invention also provides the modified ozonation catalyst prepared by the preparation method, the modified ozonation catalyst comprises an ozone catalyst and a hydrophobic material layer coated on the surface of the ozone catalyst, and the hydrophobic material layer comprises a hydrophobic filler and a hydrophobic coating.

Embodiments of the invention also provide the use of the modified ozonation catalyst in catalytic degradation of pollutants.

The embodiment of the invention also provides a wastewater treatment method, which comprises the following steps:

providing the modified ozonation catalyst described above;

and introducing ozone into the wastewater containing the pollutants and provided with the modified ozonation catalyst to perform a catalytic ozonation reaction, thereby degrading the pollutants.

The embodiment of the invention also provides a method for improving the ozone wettability of the surface of an ozonization catalyst, which comprises the following steps:

mixing hydrophobic filler with hydrophobic coating to form hydrophobic modified dispersion liquid;

and placing the ozonization catalyst in the hydrophobic modified dispersion liquid for impregnation treatment, and then calcining to prepare a modified ozonization catalyst;

wherein, the hydrophobic filler comprises any one or the combination of more than two of silicon dioxide, silicon nitride and silicon carbide; the hydrophobic coating comprises one or the combination of more than two of polytetrafluoroethylene, fluorinated polyethylene and ethylene-tetrafluoroethylene copolymer; the ozonization catalyst comprises a spherical ozone catalyst or a spherical catalyst processed and molded by powder.

Compared with the prior art, the invention has the beneficial effects that: the preparation method of the modified ozonization catalyst provided by the invention has the advantages that the surface of the spherical catalyst is coated with the hydrophobic material layer, so that the wettability of ozone on the surface of the catalyst and the surface area of the surface of the catalyst can be increased, and the catalyst can be better contacted with ozone, thereby being beneficial to more efficiently generating hydroxyl radicals, improving the reaction speed and further improving the service performance of the catalyst in catalytic ozonization.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a graph of ZJ-10 catalyst gas contact angle in example 4 of the present invention;

FIG. 2 is a gas contact angle diagram of PTFE @04 catalyst in example 4 of the present invention.

FIG. 3 is a graph showing the gas contact angle of catalyst 1 in comparative example 1 of the present invention;

FIG. 4 is a graph showing the gas contact angle of catalyst 2 in comparative example 2 of the present invention.

Detailed Description

In view of the defects of the prior art, the inventor of the present invention has long studied and largely practiced to propose the technical solution of the present invention, which will be clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Specifically, as an aspect of the technical solution of the present invention, a method for preparing a modified ozonation catalyst comprises:

In some preferred embodiments, the hydrophobic coating includes any one or a combination of two or more of Polytetrafluoroethylene (PTFE), fluorinated polyethylene (FEP), ethylene-tetrafluoroethylene Copolymer (CEP), and is not limited thereto.

In some preferred embodiments, the ozonation catalyst comprises a spherical ozone catalyst or a spherical catalyst shaped from a powder process.

In some preferred embodiments, the ozonation catalyst is a commercially available spherical ozone catalyst or a spherical catalyst shaped from powder, such as: ZJDN-OC-0305 catalyst, ZJDN-OC-0610 catalyst, ZJDN-OC-1015 catalyst, and ZJDN-OC-1520 catalyst (all from environmental protection technologies, inc. of Zhongjin Jiang, zhejiang).

In some preferred embodiments, the preparation method specifically comprises: dispersing a hydrophobic coating in water, and then adding a hydrophobic filler to form the hydrophobic modified dispersion;

wherein the content of the hydrophobic coating in the hydrophobic modified dispersion liquid is 0.01-5 wt%, and the content of the hydrophobic filler in the hydrophobic modified dispersion liquid is 0.01-5 wt%.

In some preferred embodiments, the preparation method specifically comprises: and (3) placing the ozonization catalyst in the hydrophobic modified dispersion liquid and carrying out immersion treatment at 15-40 ℃ for 5-30 min.

In some preferred embodiments, the mass ratio of the ozonation catalyst to the hydrophobic filler is 100.

In some preferred embodiments, the temperature of the calcination treatment is 200 to 500 ℃ for 15 to 30min.

In some more specific embodiments, the modified ozonation catalyst is prepared by a process comprising:

(1) Preparing a dispersion liquid with a certain percentage concentration by using a hydrophobic coating, and adding a certain amount of hydrophobic filler into the dispersion liquid to obtain a hydrophobic modified dispersion liquid capable of increasing the size of pores on the surface of the catalyst;

(2) Soaking the spherical catalyst in the hydrophobic modified dispersion liquid for a period of time, and filtering to obtain the catalyst modified in the first step;

(3) And calcining the filtered catalyst in a muffle furnace at a certain temperature in the air atmosphere, and stably coating a layer of uniformly dispersed hydrophobic material and paint on the surface of the catalyst to obtain the catalyst with improved ozone wettability.

The modified ozonization catalyst prepared by the preparation method comprises an ozone catalyst and a hydrophobic material layer coated on the surface of the ozone catalyst, wherein the hydrophobic material layer comprises a hydrophobic filler and a hydrophobic coating.

Specifically, the hydrophobic material layer coated on the surface of the ozone catalyst can improve the hydrophilicity of the catalyst (namely the ozone wettability of the surface of the catalyst), and is beneficial to the contact between the catalyst and ozone so as to more effectively catalyze and ozonize pollutants.

Further, the specific surface area of the modified ozonization catalyst is 280-500 m ² The pore size is 0.4-1 mL/g, and the porosity is 20-80%.

The modified ozonization catalyst can increase the specific surface area of the catalyst and reduce the blockage of active sites under the synergistic action of the hydrophobic filler and the hydrophobic coating, and a layer of hydrophilic and hydrophobic film is coated on the surface of the catalyst, so that the catalyst with larger specific surface area and the surface provided with the hydrophilic and hydrophobic film can be obtained, and the wettability of ozone molecules on the surface of the catalyst and the performance of the catalyst in catalyzing ozone to oxidize pollutants can be increased.

Another aspect of an embodiment of the invention also provides the use of the modified ozonation catalyst described above for the catalytic degradation of pollutants.

Further, the contaminant includes any one or a combination of two or more of atrazine, sodium acetate, ciprofloxacin, without being limited thereto.

Another aspect of an embodiment of the present invention also provides a wastewater treatment method, including:

providing the modified ozonation catalyst described above;

In some preferred embodiments, the contaminants include any one or a combination of two or more of atrazine, sodium acetate, ciprofloxacin, and are not limited thereto.

Another aspect of an embodiment of the present invention provides a method for improving ozone wettability of a surface of an ozonation catalyst, comprising:

wherein the content of the hydrophobic coating in the hydrophobic modified dispersion liquid is 0.01-1 wt%, and the content of the hydrophobic filler in the hydrophobic modified dispersion liquid is 0.01-1 wt%.

According to the invention, the specific surface area of the catalyst can be increased and the blockage of active sites can be reduced under the synergistic effect of the hydrophobic filler and the hydrophobic coating, and the surface of the catalyst is coated with a layer of hydrophilic and hydrophobic film, so that the catalyst with larger specific surface area and the surface provided with the hydrophilic and hydrophobic film can be obtained, and the wettability of ozone molecules on the surface of the catalyst and the performance of the catalyst in catalyzing ozone to oxidize pollutants can be increased. The technical solutions of the present invention are further described in detail below with reference to several preferred embodiments and the accompanying drawings, which are implemented on the premise of the technical solutions of the present invention, and the detailed embodiments and the specific operation procedures are given, but the scope of the present invention is not limited to the following embodiments.

The experimental materials used in the examples below were obtained from conventional biochemicals unless otherwise specified.

Example 1

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon nitride, uniformly stirring, adding 50g of ZJDN-OC-0305 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in the air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @01.

Example 2

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon nitride, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @02.

And (3) performance characterization: through the gas contact angle test to ZJDN-OC-0610 catalyst, PTFE @02, as shown in figure 1, figure 2, can see that at material surface cladding one deck hydrophobic material can reduce the contact angle of material to ozone to promote the material surface to ozone's infiltration nature, can draw according to material performance combination contact angle test, the better the infiltration nature of ozone, the material is stronger to the performance of catalyzing ozone oxidation degradation pollutant.

Example 3

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide, stirring uniformly, adding 50g of ZJDN-OC-1015 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in the air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @03.

Example 4

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide, stirring uniformly, adding 50g of ZJDN-OC-1520 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in the air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @04.

And (3) performance characterization: through the gas contact angle test to ZJ-10 catalyst, PTFE @04, as shown in figure 1, figure 2, can see that, wrap the contact angle that a layer of hydrophobic material can reduce the material to ozone at the material surface to promote the material surface to the infiltration nature of ozone, combine the contact angle test to obtain according to the material performance, the infiltration nature of ozone is better, and the material is stronger to the performance of catalyzing ozone oxidation degradation pollutant.

Example 5

Adding 0.2g of CPE solution into 120g of deionized water, adding 0.5g of silicon dioxide, stirring uniformly, adding 50g of Henan Liangyou-4A molecular sieve-5A catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, heating to 350 ℃ for 30min at a heating rate of 10 ℃/min in an air environment, and calcining to obtain the final CPE @ HN.

Example 6

Adding 0.2g of CPE solution into 120g of deionized water, adding 0.5g of silicon dioxide, stirring uniformly, adding 50g of LAT-CY-1 x 1cm of catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min to 350 ℃ in an air environment, and calcining for 30min to obtain the final CPE @ CY.

Example 7

Adding 0.02g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide into the solution, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering to obtain the catalyst, placing the filtered catalyst into a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @05.

Example 8

Adding 0.5g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @06.

Example 9

Adding 1.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @07.

Example 10

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.012g of silicon dioxide into the solution, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @08.

Example 11

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.1g of silicon dioxide, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @09.

Example 12

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @10.

Example 13

Adding 0.2g of PTFE solution into 120g of deionized water, adding 1.2g of silicon dioxide, stirring uniformly, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in the air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @11.

Example 14

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide into the solution, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 5min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @12.

Example 15

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide into the solution, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 15min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 350 ℃ for 30min to obtain the final PTFE @13.

Example 16

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide, stirring uniformly, adding 50g of ZJDN-OC-0610 catalyst, standing for 30min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature to 350 ℃ at a heating rate of 10 ℃/min in an air environment, and calcining for 30min to obtain the final PTFE @14.

Example 17

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide into the solution, uniformly stirring, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering to obtain the catalyst, placing the filtered catalyst into a muffle furnace, raising the temperature at a rate of 10 ℃/min in an air environment, and calcining at 200 ℃ for 30min to obtain the final PTFE @15.

Example 18

Adding 0.2g of PTFE solution into 120g of deionized water, adding 0.5g of silicon dioxide, stirring uniformly, adding 50g of ZJDN-OC-0610 catalyst, standing for 10min, filtering, taking out the catalyst, placing the filtered catalyst in a muffle furnace, raising the temperature at a rate of 10 ℃/min in the air environment, and calcining at 500 ℃ for 30min to obtain the final PTFE @16.

Comparative example 1

The process is the same as example 1 except that PTFE is absent; is marked as catalyst 1;

comparative example 2

The method is the same as example 1 except that silicon nitride is absent; is recorded as catalyst 2;

carrying out catalytic ozonization on the catalyst under the reaction condition that 400mL of 50ppm sodium acetate is put into a reaction tower and 30g of the catalyst is added; ozone is generated by an ozone generator, the concentration of the ozone is 11mg/L, the flow rate is 0.25L/min, the reaction time is 15min, and a water sample is taken for COD test; 50ppm sodium acetate was tested and had a COD value of 48.16. The test results are shown in table 1 below.

TABLE 1 characterization data for catalysts in examples 1-20 and comparative examples

All catalysts in the above examples, which were not modified, were pelletized ozone catalysts which were directly commercially available.

Through the experimental tests, the improvement of the performance can be obtained from the experimental data after the material is modified.

In addition, the inventors of the present invention have also made experiments with other materials, process operations, and process conditions described in the present specification with reference to the above examples, and have obtained preferable results.

It should be understood that the technical solution of the present invention is not limited to the above-mentioned specific embodiments, and all technical modifications made according to the technical solution of the present invention fall within the protection scope of the present invention without departing from the spirit of the present invention and the protection scope of the claims.

Claims

1. A method of preparing a modified ozonation catalyst, comprising:

wherein the hydrophobic filler comprises any one of silicon dioxide, silicon nitride and silicon carbide or a combination of more than two of the silicon dioxide, the silicon nitride and the silicon carbide.

2. The method of claim 1, wherein: the hydrophobic coating comprises one or the combination of more than two of polytetrafluoroethylene, fluorinated polyethylene and ethylene-tetrafluoroethylene copolymer;

and/or the ozonization catalyst comprises a spherical ozone catalyst or a spherical catalyst processed and molded by powder.

3. The method according to claim 1, comprising: dispersing a hydrophobic coating in water, and then adding a hydrophobic filler to form the hydrophobic modified dispersion;

4. The preparation method according to claim 1, characterized by specifically comprising: and (3) placing the ozonization catalyst in the hydrophobic modified dispersion liquid and carrying out immersion treatment at 15-40 ℃ for 5-30 min.

5. The method of claim 1, wherein: the mass ratio of the ozonization catalyst to the hydrophobic filler is 100.

6. The method of claim 1, wherein: the temperature of the calcination treatment is 200-500 ℃, and the time is 15-30 min.

7. The modified ozonization catalyst prepared by the preparation method of any one of claims 1 to 6, which comprises an ozone catalyst and a hydrophobic material layer coated on the surface of the ozone catalyst, wherein the hydrophobic material layer comprises a hydrophobic filler and a hydrophobic coating;

preferably, the specific surface area of the modified ozonization catalyst is 280-500 m ² The pore size is 0.4-1 mL/g, and the porosity is 20-80%.

8. Use of the modified ozonation catalyst of claim 7 to catalytically degrade a contaminant; preferably, the pollutant comprises any one or a combination of more than two of atrazine, sodium acetate and ciprofloxacin.

9. A method for treating wastewater, comprising:

providing the modified ozonation catalyst of claim 7;

ozone is introduced into the wastewater containing the pollutants and provided with the modified ozonization catalyst to carry out catalytic ozonization reaction, so that the pollutants are degraded.

10. A method for improving ozone wettability of an ozonation catalyst surface, comprising: