A irradiation catalytic process for degrading coal chemical wastewater and its application

Abstract

The present invention belongs to the field of radiation catalysis technology, and specifically relates to a radiation catalytic process method for degrading coal chemical wastewater and its application. Specifically, the radiation catalytic process method includes: applying an iron-based metal organic framework / titanium dioxide composite material to the coal chemical wastewater as a radiation catalyst, and then performing radiation treatment to degrade the coal chemical wastewater. The iron-based metal organic framework / titanium dioxide composite material catalyst can utilize radiation energy to catalyze the efficient degradation of high molecular weight organic compounds in aqueous solution, and can be repeatedly recycled and reused, has good stability, reduces the treatment cost of radiation-degraded wastewater, and has good practical application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of radiation catalysis, and in particular relates to a radiation catalysis process method for degrading coal chemical wastewater and an application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] In the process of urbanization, industries such as coal chemical industry, printing and dyeing, pharmaceuticals, electronics, metallurgy, and pulp and paper industries annually emit large amounts of high-concentration, difficult-to-degrade organic pollutants, posing a significant long-term threat to the environment and human health. Traditional wastewater treatment technologies, such as biochemical, chemical, and physical treatment, face technical bottlenecks and are unable to efficiently, quickly, and cost-effectively remove high concentrations of organic pollutants.

[0004] Electron beam irradiation, as a novel wastewater treatment technology, has attracted widespread attention and widespread application. By generating hydroxyl radicals, electron beam irradiation rapidly degrades organic pollutants, making it a highly effective method for treating and purifying industrial wastewater. Compared to traditional biochemical, physical, and chemical treatment methods, electron beam irradiation offers higher treatment efficiency and shorter treatment cycles, without the need for additional chemical agents. Therefore, with the goals of zero emissions and wastewater reuse in mind, electron beam irradiation has become a key area of ​​improvement for wastewater treatment.

[0005] The advantage of electron beam irradiation technology is that it can directly degrade organic pollutants, achieving wastewater purification and resource utilization. This technology can effectively remove various difficult-to-degrade, high-concentration organic pollutants such as agricultural chemicals, petroleum hydrocarbons, dyes, nitrosamines, and cyanides from various water bodies, including industrial wastewater, urban sewage, rural domestic sewage, insecticides, and pesticides. The treatment effect of electron beam irradiation is very significant, meeting national and international environmental emission standards, and enabling intermediate and post-treatment and reuse of water, which is of great significance to promoting sustainable development. However, the application of electron beam irradiation technology still faces some challenges, one of the main issues being the high treatment cost. Summary of the Invention

[0006] To address the shortcomings of the aforementioned prior art, the inventors, after extensive technical and practical exploration, have developed a radiation-catalytic process for degrading coal chemical wastewater and its application. Specifically, by developing a synergistic radiation-catalytic process, the present invention significantly improves the degradation rate of organic pollutants by electron beam irradiation, thereby reducing treatment costs and promoting the industrial application of the technology. This research achievement led to the completion of the present invention.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] The first aspect of the present invention provides a radiation catalytic process method for degrading coal chemical wastewater, which comprises: applying an iron-based metal organic framework / titanium dioxide composite material to the coal chemical wastewater as a radiation catalyst, and then performing radiation treatment to degrade the coal chemical wastewater.

[0009] The iron-based metal organic framework / titanium dioxide composite material is prepared by the following method: TiO2 obtained after pretreatment and the iron-based metal organic framework material are mixed, dried, and crushed to obtain a mixed powder, and the mixed powder is subjected to electron beam irradiation treatment.

[0010] The second aspect of the present invention provides the application of the above-mentioned radiation catalytic process method in the treatment of coal chemical wastewater.

[0011] Compared with the existing technical solutions, the above one or more technical solutions have the following beneficial effects:

[0012] The above technical solution provides a radiation catalytic process method for degrading coal chemical wastewater. The process method uses an iron-based metal organic framework / titanium dioxide composite catalyst, which can utilize radiation energy to catalyze the efficient degradation of high molecular organic compounds in aqueous solution, and can be repeatedly recycled and reused. It has good stability, reduces the treatment cost of radiation-degraded wastewater, and has good practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0014] Figure 1 This is an electron micrograph of the iron-based metal-organic framework / titanium dioxide composite catalyst prepared in Example 1 of the present invention; wherein, 1-iron-based metal-organic framework, 2-TiO2. DETAILED DESCRIPTION

[0015] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0016] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0017] In a typical embodiment of the present invention, a radiation catalytic process method for degrading coal chemical wastewater is provided, which comprises: applying an iron-based metal organic framework / titanium dioxide composite material to the coal chemical wastewater as a radiation catalyst, and then performing radiation treatment to degrade the coal chemical wastewater.

[0018] The addition amount of the iron-based metal organic framework / titanium dioxide composite material is 0.5-5 g / L, and further 1 g / L.

[0019] The specific conditions of the irradiation treatment are: irradiation energy of 1-5MeV, beam intensity of 10-50mA, absorbed dose of 1-10kGy, and irradiation time of 30-60 seconds; preferably: irradiation energy of 3MeV, beam intensity of 30mA, absorbed dose of 5kGy, and irradiation time of 40 seconds.

[0020] The iron-based metal organic framework / titanium dioxide composite material is prepared by the following method: TiO2 obtained after pretreatment and the iron-based metal organic framework material are mixed, dried, and crushed to obtain a mixed powder, and the mixed powder is subjected to electron beam irradiation treatment.

[0021] The mixing is carried out in water, and further, the mixing is ultrasonic mixing, the ultrasonic power is 400-600W, and the ultrasonic time is 5-20min;

[0022] The mass ratio of TiO2 to the iron-based metal organic framework material in the mixed powder is 1:2-5, preferably 1:2.5;

[0023] The specific conditions of the electron beam irradiation treatment are: irradiation energy 1-10 MeV, irradiation beam current intensity 10-300 mA, irradiation dose 0.5-20 kGy, irradiation time 10-60 min; more preferably, irradiation energy 5 MeV, irradiation beam current intensity 100 mA, irradiation dose 1-5 kGy, irradiation time 30 min.

[0024] The TiO2 pretreatment method is as follows: controlling the heating rate to 4-10°C / min, calcining TiO2 at 300-600°C for 1-3 hours, and further calcining at 400°C for 2 hours;

[0025] The iron-based metal organic framework material is prepared by the following method: adding an iron salt and an organic ligand to dimethylformamide (DMF) and mixing them for a first-stage heating treatment, cooling and centrifuging to obtain a first crude product, adding the first crude product to DMF and performing a second-stage heating treatment, cooling and centrifuging to obtain a second crude product, and then heating the second crude product and ethanol for a third stage, cooling, centrifuging, and drying to obtain the product;

[0026] The iron salt can be an inorganic salt of iron and an inorganic salt hydrate, such as ferric chloride, ferric nitrate, etc., which are not specifically limited here. In one embodiment of the present invention, the iron salt is ferric chloride hexahydrate; the organic ligand can be imidazole, phthalic acid, etc., which are not specifically limited here. Further, the organic ligand is phthalic acid;

[0027] In another embodiment of the present invention, the mass ratio of FeCl3·6H2O to terephthalic acid is 1.5-4:1. Preferably, it is 6.75:2.06;

[0028] The mass ratio of FeCl3·6H2O to TiO2 is 2-5:1, preferably 6.75:1.98.

[0029] The conditions of the first stage heating treatment are: heating treatment at 100-120°C for 12-24 hours, preferably heating treatment at 110°C for 20 hours;

[0030] The conditions for the second stage heating treatment are: heating at 70-90°C for 1-5 hours, preferably 80°C for 3 hours;

[0031] The conditions for the three-stage heating treatment are: heating at 50-70°C for 10-24 hours, preferably heating at 60°C for 12 hours.

[0032] The centrifugal treatment conditions for cooling and centrifuging after the above three stages of heating can be: centrifugal treatment at 6000-10000 rpm for 5-30 min, preferably centrifugal treatment at 8000 rpm for 10 min.

[0033] In another specific embodiment of the present invention, there is provided application of the above-mentioned radiation catalytic process method in the treatment of coal chemical wastewater.

[0034] Coal chemical wastewater is industrial wastewater generated during coal chemical production processes. It has complex composition, high pollutant concentrations, significant hazards, and poor biodegradability. The irradiation catalytic process of the present invention can efficiently and rapidly degrade high-concentration organic compounds, as well as difficult-to-degrade, long-chain polymeric organic matter, in this coal chemical wastewater. This significantly reduces the COD content of the coal chemical wastewater, achieving excellent technical results. Furthermore, the prepared iron-based metal-organic framework / titanium dioxide composite material is recyclable and exhibits excellent stability, further reducing processing costs.

[0035] The present invention will be further described below in conjunction with specific examples. The following examples are only for the purpose of explaining the present invention and are not intended to limit its content. Any simple modifications, equivalent changes and modifications made to the embodiments according to the technical essence of the present invention are within the scope of the technical solution of the present invention. The same batch of coal chemical wastewater was used in each example, and its initial COD was 510 mg / L.

[0036] Example 1

[0037] (1) 6.75 g of FeCl3·6H2O and 2.06 g of terephthalic acid were mixed with 150 mL of DMF and transferred to a polytetrafluoroethylene-lined stainless steel reactor and heated at 110°C for 20 h. The mixture was cooled and centrifuged at 8000 rpm for 10 min to obtain a crude product a. The crude product a was added to a reaction vessel containing 800 ml of DMF and heated at 80°C for 3 h. The mixture was cooled and centrifuged (8000 rpm for 10 min) to remove the residual terephthalic acid in the product to obtain a crude product b. The crude product b obtained in the previous step and 35 ml of ethanol were added to a reactor and heated at 60°C for 12 h. The mixture was cooled and centrifuged (8000 rpm for 10 min) and dried in a vacuum at 110°C for 10 h to obtain a pure product, an iron-based metal-organic framework.

[0038] (2) 1.98 g of TiO2 (commercial model P25) was calcined at 400°C for 2 h at a heating rate of 4°C / min to obtain pretreated TiO2. The Fe-based metal-organic framework and pretreated TiO2 were mixed in water and ultrasonically treated (ultrasonic power of 400 W for 10 min), dried, and ground to obtain powder C. The mass ratio of TiO2 to Fe-based metal-organic framework was 40%.

[0039] (3) Powder C was irradiated with an electron beam at an irradiation energy of 5 MeV, an irradiation beam intensity of 100 mA, an irradiation dose of 1 kGy, and an irradiation time of 30 min to obtain the final composite catalyst.

[0040] (4) The catalyst was added to the coal chemical wastewater after coagulation and sedimentation. The COD of the wastewater was 510 mg / L, and the addition amount was 1 g / L. The wastewater was irradiated with an electron beam with an irradiation energy of 3 MeV, a beam current of 30 mA, an absorbed dose of 5 kGy, and an irradiation time of 40 seconds.

[0041] Example 2

[0042] The process was carried out in accordance with Example 1, except that in step 1, the mass of terephthalic acid was changed from 2.06 g to 1.02 g. The other steps were the same as those in Example 1.

[0043] Example 3

[0044] The process was carried out in accordance with Example 1, except that in step 2, TiO2 was not pretreated but directly mixed with the Fe-based metal-organic framework. The other steps were the same as those in Case 1.

[0045] Example 4

[0046] The process was carried out in accordance with Example 1, except that in step 3, powder C was not irradiated, and the mixed powder obtained in step 2 was directly used as a catalyst. The other steps were the same as in Example 1.

[0047] Example 5

[0048] The process was carried out in accordance with Example 1, except that in step 3, the irradiation time of powder C was 0.2 kGy. The other steps were the same as those in Example 1.

[0049] Example 6

[0050] The process was carried out in accordance with Example 1, except that in step 4, no catalyst was added to the wastewater and the wastewater was directly irradiated. Other conditions were the same as those in Example 1.

[0051] Table 1 Comparison of sewage degradation rates in various embodiments

[0052] Example COD (mg / L) COD degradation rate Sewage as is 510 / Example 1 166 67％ Example 2 187 53％ Example 3 184 44％ Example 4 201 41％ Example 5 193 32％ Example 6 375 26％

[0053] As shown in Table 1, the composite catalyst obtained in Example 1 exhibits the best catalytic activity, significantly improving the COD removal rate compared to single electron beam irradiation. It is particularly noteworthy that the composite catalyst prepared in Example 1 has been shown to be reusable for more than 30 times, with catalyst recovery, drying, and repeated sintering allowing for further recycling for more than 30 times.

[0054] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A irradiation catalytic process for degrading coal chemical wastewater, characterized in that: The method comprises: adding an iron-based metal organic framework / titanium dioxide composite material to coal chemical wastewater as an irradiation catalyst, and then performing irradiation treatment to degrade the coal chemical wastewater; wherein the amount of the iron-based metal organic framework / titanium dioxide composite material added is 0.5-5g / L; The iron-based metal organic framework / titanium dioxide composite material is prepared by the following method: TiO2 obtained after pretreatment and the iron-based metal organic framework material are mixed, dried, and crushed to obtain a mixed powder, and the mixed powder is subjected to electron beam irradiation treatment. The TiO2 pretreatment method is as follows: controlling the heating rate to 4-10°C / min, and calcining the TiO2 at 300-600°C for 1-3h; The iron-based metal organic framework material is prepared by the following method: adding an iron salt and an organic ligand to dimethylformamide and mixing them for a first-stage heating treatment, cooling and centrifuging to obtain a first crude product, adding the first crude product to DMF and performing a second-stage heating treatment, cooling and centrifuging to obtain a second crude product, and then heating the second crude product and ethanol for a third stage, cooling, centrifuging, and drying to obtain the product; The conditions for the first stage of heating treatment are: heating treatment at 100-120°C for 12-24h; The conditions for the second stage heating treatment are: heating treatment at 70-90°C for 1-5h; The conditions for the three-stage heating treatment are: heating at 50-70°C for 10-24h.

2. The irradiation catalysis process according to claim 1, characterized in that: The TiO2 pretreatment method is calcining at 400°C for 2h.

3. The irradiation catalysis process according to claim 1, characterized in that: The specific conditions of the irradiation treatment are: irradiation energy of 1-5 MeV, beam intensity of 10-50 mA, absorbed dose of 1-10 kGy, and irradiation time of 30-60 seconds.

4. The irradiation catalysis process according to claim 1, characterized in that: The mixing is carried out in water; The mass ratio of TiO2 to the iron-based metal organic framework material in the mixed powder is 1:2-5; The specific conditions of the electron beam irradiation treatment are: irradiation energy 1-10 MeV, irradiation beam intensity 10-300 mA, irradiation dose 0.5-20 kGy, and irradiation time 10-60 min.

5. The irradiation catalytic process according to claim 4, characterized in that: The mixing is ultrasonic mixing, the ultrasonic power is 400-600W, and the ultrasonic time is 5-20min.

6. The irradiation catalysis process according to claim 1, characterized in that: The iron salts are inorganic salts of iron and inorganic salt hydrates, including ferric chloride and ferric nitrate.

7. The irradiation catalytic process according to claim 6, characterized in that: The iron salt is ferric chloride hexahydrate; the organic ligand is imidazole and phthalic acid.

8. The irradiation catalytic process according to claim 7, characterized in that: Furthermore, the organic ligand is phthalic acid.

9. The irradiation catalytic process according to claim 7, characterized in that: The mass ratio of the ferric chloride hexahydrate to terephthalic acid is 1.5-4:1; The mass ratio of the ferric chloride hexahydrate to TiO2 is 2-5:

1.

10. The irradiation catalysis process according to claim 1, characterized in that: The centrifugal treatment conditions for cooling and centrifuging after the three stages of heating are all: centrifugation at 6000-10000 rpm for 5-30 min.

11. Use of the irradiation catalytic process according to any one of claims 1 to 10 in the treatment of coal chemical wastewater.

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