Irradiation catalysis process method for degrading coal chemical sewage and application thereof

Abstract

The invention belongs to the technical field of irradiation catalysis, and particularly relates to an irradiation catalysis process method for degrading coal chemical sewage and application of the irradiation catalysis process method. Specifically, the irradiation catalysis process method comprises the following steps: applying an iron-based metal organic framework / titanium dioxide composite material to the coal chemical sewage as an irradiation catalyst, and then carrying out irradiation treatment to degrade the coal chemical sewage. The iron-based metal organic framework / titanium dioxide composite material catalyst can catalyze and efficiently degrade high-molecular organic compounds in an aqueous solution by utilizing irradiation energy, can be recycled repeatedly, is good in stability, reduces the treatment cost of irradiation degradation of sewage, and has good practical application value.

Description

Technical Field

[0001] The invention belongs to the technical field of radiation catalysis, and specifically 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 the 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 a person skilled in the art.

[0003] In the process of urbanization, some industries such as coal chemical industry, printing and dyeing, pharmaceuticals, electronics, metallurgy and pulp and paper will discharge a large amount of high-concentration, difficult-to-degrade organic pollutants every year, which has long posed a great threat to the environment and human health. Traditional sewage treatment technologies such as biochemical treatment, chemical treatment and physical treatment have technical bottlenecks and cannot remove high-concentration organic pollutants efficiently, quickly and cheaply.

[0004] Electron beam irradiation has been widely used and received attention as a new type of sewage treatment technology. Electron beam irradiation can generate hydroxyl radicals to achieve rapid degradation of organic pollutants, and is an efficient method for industrial wastewater treatment and purification. Compared with traditional biochemical, physical and chemical treatment methods, electron beam irradiation has higher treatment efficiency and shorter treatment cycle, and does not require the addition of additional chemicals. Therefore, under the goal of zero discharge and sewage reuse, electron beam irradiation technology has become one of the important directions for the improvement of current sewage treatment technology.

[0005] The advantage of electron beam irradiation technology is that it can directly degrade organic pollutants, achieve sewage purification and wastewater resource utilization. This technology can effectively remove various difficult-to-degrade, high-concentration organic pollutants such as agricultural organic matter, petroleum hydrocarbons, dyes, nitrosamines, cyanides, etc. in various industrial wastewater, urban sewage, rural domestic sewage, insecticides, pesticides and other water bodies. The treatment effect of electron beam irradiation is very significant, which can meet national and international environmental emission standards, and can achieve water intermediate and post-treatment and reuse, which is of great significance to promoting sustainable development. However, there are still some challenges in the application of electron beam irradiation technology, one of the main problems is the high treatment cost. Summary of the invention

[0006] In view of the deficiencies in the above-mentioned prior art, the inventors, after long-term technical and practical exploration, provide a radiation catalytic process method for degrading coal chemical wastewater and its application. Specifically, the present invention can significantly improve the degradation rate of organic pollutants by electron beam irradiation by developing a synergistic radiation catalytic process, thereby reducing the treatment cost of the technology and promoting the industrial application of the technology. Based on the above research results, the present invention is completed.

[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, the method comprising: applying an iron-based metal organic framework / titanium dioxide composite material to the coal chemical wastewater for use 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 scheme 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, 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 in the specification, 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 are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those 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, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

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

[0018] Among them, the addition amount of the iron-based metal organic framework / titanium dioxide composite material is 0.5-5g / L, and further 1g / 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: the 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 to obtain the mixed powder;

[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 1-10MeV, irradiation beam current intensity 10-300mA, irradiation dose 0.5-20kGy, irradiation time 10-60min; more preferably, irradiation energy 5MeV, irradiation beam current intensity 100mA, irradiation dose 1-5kGy, irradiation time 30min.

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

[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 performing a third-stage heating treatment on the second crude product and ethanol, cooling, centrifuging and drying to obtain the product;

[0026] The iron salt may 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 a specific embodiment of the present invention, the iron salt is ferric chloride hexahydrate; the organic ligand may be imidazole, phthalic acid, etc., which are not specifically limited here. Further, the organic ligand is phthalic acid;

[0027] In another specific 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 12-24h, preferably heating treatment at 110°C for 20h;

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

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

[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 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] The coal chemical wastewater is industrial wastewater generated in the coal chemical production process. It has the characteristics of complex composition, high concentration of pollutants, great harm, poor biodegradability, etc. The irradiation catalytic process method of the present invention can efficiently and quickly degrade high-concentration organic compounds, difficult-to-degrade, long-chain high-molecular organic matter, etc. in the above-mentioned coal chemical wastewater, which is specifically manifested in significantly reducing the COD of coal chemical wastewater and achieving good technical effects. At the same time, the iron-based metal organic framework / titanium dioxide composite material prepared above can be recycled repeatedly and has good stability, thereby further reducing the processing cost.

[0035] The present invention is further described below in conjunction with specific examples. The following examples are only for explaining the present invention and are not intended to limit its contents. Any simple modification, equivalent changes and modifications made to the implementation methods 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 is used in each embodiment, and its initial COD is 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 crude product a was obtained after cooling and centrifuging at 8000 rpm for 10 min. The crude product a was added to a reaction vessel with 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 the 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 vacuum dried 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 under the following conditions: heating rate of 4°C / min, calcination at 400°C for 2 h to obtain pretreated TiO2; the Fe-based metal organic framework and the pretreated TiO2 were mixed in water, ultrasonically treated (ultrasonic power of 400 W, ultrasonic time of 10 min), dried and ground to obtain powder C. The mass ratio of TiO2 to the Fe-based metal organic framework was 40%.

[0039] (3) The 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, the irradiation energy was 3 MeV, the beam intensity was 30 mA, the absorbed dose was 5 kGy, and the irradiation time was 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, and the other steps were the same as those in Example 1.

[0043] Example 3

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

[0045] Example 4

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

[0047] Example 5

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

[0049] Example 6

[0050] The process is carried out in accordance with Example 1, except that in step 4, no catalyst is added to the wastewater and the wastewater is directly irradiated. Other conditions are 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 original 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] From the comparison of COD removal rates of sewage in Table 1, it can be seen that the composite catalyst obtained in Example 1 has the best catalytic activity, and significantly improves the COD removal rate compared to single irradiation of electron beams. It is particularly worth mentioning that it has been verified that the composite catalyst prepared in Example 1 of the present invention can be repeatedly used for more than 30 times, and after catalyst recovery, drying and repeated sintering, it can be recycled for more than 30 times.

[0054] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A radiation 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 addition amount of the iron-based metal organic framework / titanium dioxide composite material is 0.5-5g / L.

2. The irradiation catalytic 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.

3. The irradiation catalytic process according to claim 1, characterized in that: 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.

4. The irradiation catalytic process according to claim 3, characterized in that: 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; 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, irradiation time 10-60 min; The pretreatment method of TiO2 is: controlling the heating rate to 4-10°C / min, calcining TiO2 at 300-600°C for 1-3h, and further calcining at 400°C for 2h.

5. The irradiation catalytic process according to claim 3, characterized in that: The iron-based metal organic framework material is prepared by the following method: adding iron salt and 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 for a second-stage heating treatment, cooling and centrifuging to obtain a second crude product, and subjecting the second crude product and ethanol to a third-stage heating treatment, cooling, centrifuging and drying to obtain the product.

6. The irradiation catalytic process according to claim 3, characterized in that: The iron salt is an inorganic salt of iron and an inorganic salt hydrate, including ferric chloride and ferric nitrate; further, the iron salt is ferric chloride hexahydrate; the organic ligand is imidazole and phthalic acid; further, the organic ligand is phthalic acid.

7. The irradiation catalytic process according to claim 6, characterized in that: The mass ratio of FeCl3·6H2O to terephthalic acid is 1.5-4:1; The mass ratio of FeCl3·6H2O to TiO2 is 2-5:

1.

8. The irradiation catalytic process according to claim 3, characterized in that: The conditions of the first stage 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 of the three-stage heating treatment are: heating at 50-70°C for 10-24h.

9. The irradiation catalytic process according to claim 8, characterized in that: The centrifugal treatment conditions for cooling and centrifuging after the three stages of heating are all: centrifugal treatment at 6000-10000 rpm for 5-30 min.

10. Application of the irradiation catalytic process method according to any one of claims 1 to 9 in the treatment of coal chemical wastewater.

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