A method for degrading organic pollutants by a MOF catalyst in cooperation with electron beam irradiation technology

Abstract

The application belongs to the technical field of sewage treatment, and particularly relates to a method for degrading organic pollutants by using MOF catalysts in cooperation with electron beam irradiation technology, which comprises the following steps: (1) forming a saturated solution of rhodamine B and deionized water to prepare a rhodamine B aqueous solution; (2) adding metal organic framework materials as catalysts to the rhodamine B aqueous solution prepared in step (1) and uniformly mixing to prepare a mixed solution; and (3) performing electron beam irradiation on the mixed solution prepared in step (2) to degrade the rhodamine B organic pollutants. 2+ The method has the advantages that the degradation is performed at low temperature, the process is simple, controllability is high, and the degradation rate is obviously advantageous; the method has very high degradation efficiency in the process of treating high-concentration pollutants; the introduced catalysts can provide high-concentration Fe 2+ and O2, and can directly perform solid-liquid separation after degradation, so that secondary pollution of the catalysts is avoided, and the cost of sewage treatment is reduced.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a method for degrading organic pollutants using MOF catalyst synergistic electron beam irradiation technology. Background Technology

[0002] Organic wastewater generated from industrial and domestic activities has become a thorny issue in environmental governance due to its complex composition, high pollution load, and difficulty in treatment. This type of wastewater contains a wide variety of pollutants, potentially including heavy metals, aromatic compounds, sulfides, and nitrogen oxides—a number of recalcitrant and toxic chemical components that pose a threat to ecosystems and human health. Furthermore, its chemical oxygen demand (COD) in some industrial wastewater can even exceed 100,000 ppm, far exceeding the natural purification capacity of water bodies. Therefore, thorough treatment of wastewater is crucial. Initial treatment using physical and chemical methods aims to reduce toxicity and improve biodegradability. This is followed by the integration of various advanced processes to achieve efficient removal and purification, thereby reducing its environmental harm. Currently, there are three main technologies for treating organic wastewater: physical treatment (adsorption, membrane separation, coagulation and flocculation), chemical treatment (electrochemical oxidation, photocatalytic oxidation, Fenton treatment technology), and biological treatment (anaerobic treatment, aerobic treatment, and combined anaerobic-aerobic treatment).

[0003] While current physical, chemical, and biological treatment technologies for organic wastewater each have their own characteristics, they also share some common problems that limit their application and efficiency. This is especially true when dealing with high concentrations and complex compositions of organic pollutants, where limitations are often apparent, specifically: treatment efficiency is significantly affected by the type and concentration of pollutants; some methods generate secondary pollution, such as coagulant residues or chemical reagent byproducts; operating costs are high, as seen in processes like membrane separation, electrochemical processes, and continuous aeration; and they also have high requirements for equipment, operating conditions, and procedures, and are easily affected by fluctuations in wastewater properties. These technologies generally suffer from insufficient treatment depth when dealing with such high concentrations of organic matter, often requiring the combined use of multiple processes to achieve the desired treatment effect. In summary, improving treatment efficiency, reducing costs, and minimizing secondary pollution are common challenges faced by these methods. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for degrading organic pollutants using MOF catalysts in conjunction with electron beam irradiation.

[0005] This invention relates to a method for degrading organic pollutants using MOF catalysts in conjunction with electron beam irradiation, comprising the following steps:

[0006] (1) Rhodamine B was reacted with deionized water to form a saturated solution, and an aqueous solution of Rhodamine B was prepared.

[0007] (2) Add a metal-organic framework material as a catalyst to the Rhodamine B aqueous solution obtained in step (1), mix well, and obtain a mixed solution;

[0008] (3) The mixed solution obtained in step (2) is subjected to electron beam irradiation to degrade the organic pollutant Rhodamine B.

[0009] Preferably, in step (1), the mass concentration of the Rhodamine B aqueous solution is 100-1000 mg / L.

[0010] Preferably, in step (2), the mass concentration of the metal-organic framework material in the mixed solution is 2.75 g / L, and the metal-organic framework material is in the form of Fe... 2+ As a metal source, Fe in the mixed solution 2+ The concentration was 400 mmol / L.

[0011] Preferably, in step (2), the preparation method of the metal-organic framework material is as follows:

[0012] FeSO4·7H2O, Fe(NO3)3·9H2O, H4ABTC and CH3COOH were dissolved in DMF to obtain a mixed metal salt solution. The mixed metal salt solution was transferred to a Teflon container and then placed in an oven and heated at 150°C for 24 h. The resulting solid precipitate was washed three times with ethanol and finally dried at 80°C for 12 h to obtain a metal-organic framework material.

[0013] Preferably, the molar concentrations of FeSO4·7H2O, Fe(NO3)3·9H2O, H4ABTC, and CH3COOH in the mixed metal salt solution are all 100 mmol / L.

[0014] Preferably, in step (3), the dose of electron beam irradiation is 15 to 210 kGy.

[0015] Preferably, in step (3), the temperature of the electron beam irradiation is 0 to 10°C.

[0016] Preferably, in step (3), the humidity of the electron beam irradiation is 30-80%.

[0017] Preferably, in step (3), the electron beam radiation utilizes β rays as the energy source.

[0018] Preferably, the irradiation dose rate of the β rays is 64800 kGy / h.

[0019] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0020] (1) The method of degrading organic pollutants by combining MOF catalyst with electron beam irradiation technology can be carried out at low temperature, the process is simple, the controllability is strong, and the degradation rate advantage is very obvious.

[0021] (2) The method of degrading organic pollutants by combining MOF catalyst with electron beam irradiation technology shows a very high degradation efficiency in the process of treating high concentrations of pollutants;

[0022] (3) The method of degrading organic pollutants by combining MOF catalyst with electron beam irradiation technology can provide a high concentration of Fe. 2+ Meanwhile, after degradation, solid-liquid separation is carried out directly, which will not cause secondary pollution of the catalyst and reduce the cost of wastewater treatment.

[0023] (4) The method of degrading organic pollutants by combining MOF catalyst with electron beam irradiation technology is based on industrialization, and the radiation source is proposed on the basis of industrialization, with obvious industrial advantages. Detailed Implementation

[0024] To better understand the above-mentioned objectives, features and advantages of the present invention, the present invention will be further described below in conjunction with embodiments.

[0025] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0026] Example 1

[0027] Preparation of metal-organic framework materials (MOF catalysts):

[0028] 278 g (1 mol) FeSO4·7H2O, 404 g (1 mol) Fe(NO3)3·9H2O, 358.3 g (1 mol) H4ABTC and 60 g (1 mol) CH3COOH were dissolved in 10 ml DMF to obtain a mixed metal salt solution. The mixed metal salt solution was transferred to a Teflon container and then placed in an oven and heated at 150 °C for 24 h. The resulting solid precipitate was washed three times with ethanol and finally dried at 80 °C for 12 h to obtain a metal-organic framework material.

[0029] Example 2

[0030] A method for degrading organic pollutants using MOF catalysts in conjunction with electron beam irradiation includes the following steps:

[0031] (1) Rhodamine B was mixed with deionized water to form a saturated solution, and aqueous solutions of Rhodamine B with mass concentrations of 100 mg / L, 200 mg / L, 300 mg / L, 400 mg / L, 500 mg / L, 600 mg / L, 800 mg / L and 1000 mg / L were prepared respectively.

[0032] (2) Take 25 ml of each concentration of Rhodamine B aqueous solution obtained in step (1) in two portions, one portion as the control group and the other portion as the experimental group. Add 68.75 mg of MOF catalyst prepared in Example 1 to each concentration of Rhodamine B aqueous solution in the experimental group, mix evenly, and obtain a mixed solution.

[0033] (3) The control group solution and the experimental group mixture obtained in step (2) were irradiated with electron beams at a dose rate of 64800 kGy / h. The temperature during irradiation was 8℃ and the humidity was 40%.

[0034] The sample solution was tested using an ultraviolet spectrophotometer, and the degradation efficiency of Rhodamine B organic pollutants at degradation equilibrium was recorded. The results are shown in Table 1.

[0035] Table 1 Irradiation test results of Example 2

[0036] Rhodamine B aqueous solution concentration (mg / L) Degradation equilibrium irradiation dose (kGy) (Control group) Irradiation degradation efficiency (%) (Experimental group) Irradiation and introduction of catalyst degradation efficiency (%) 100 30 100 100 200 45 100 100 300 45 100 100 400 90 85 100 500 120 70 99 600 135 65 95 800 180 60 79 1000 210 53 60

[0037] Table 1 shows that, compared with irradiation alone, the irradiation-assisted MOF catalyst method has a higher degradation efficiency for the same concentration of Rhodamine B aqueous solution, and it can also achieve high degradation efficiency for high concentrations of Rhodamine B aqueous solution. This indicates that electron beam irradiation and MOF catalyst have a synergistic effect, which can improve the degradation efficiency of Rhodamine B.

[0038] Example 3

[0039] A method for degrading organic pollutants using MOF catalysts in conjunction with electron beam irradiation includes the following steps:

[0040] (1) Rhodamine B was mixed with deionized water to form a saturated solution, and an aqueous solution of Rhodamine B with a mass concentration of 500 mg / L was prepared.

[0041] (2) Take 25 ml of the Rhodamine B aqueous solution obtained in step (1) and add 68.75 mg of MOF catalyst that has been circulated 1-5 times (after solid-liquid separation, the solid of the MOF catalyst can be washed with ethanol, dried and then recycled). Mix evenly to obtain a mixed solution.

[0042] (3) The mixed solution obtained in step (2) was subjected to electron beam irradiation with β rays at a dose rate of 64800 kGy / h. The temperature during irradiation was 10℃ and the humidity was 60%.

[0043] The sample solution was tested using an ultraviolet spectrophotometer, and the degradation efficiency of Rhodamine B organic pollutants at degradation equilibrium was recorded. The results are shown in Table 2.

[0044] Table 2 Irradiation test results of Example 3

[0045] Group MOF catalyst cycle times Irradiation dose (kGy) Final degradation efficiency (%) 1 1 120 99 2 2 120 99 3 3 120 99 4 4 120 99 5 5 120 97

[0046] Table 2 shows that even after five cycles of recycling, the MOF catalyst, combined with electron beam irradiation, still exhibits excellent degradation effects on Rhodamine B.

[0047] Example 4

[0048] A method for degrading organic pollutants using MOF catalysts in conjunction with electron beam irradiation includes the following steps:

[0049] (1) Rhodamine B was mixed with deionized water to form a saturated solution, and an aqueous solution of Rhodamine B with a mass concentration of 500 mg / L was prepared.

[0050] (2) Take 11 portions of 25 ml of the Rhodamine B aqueous solution obtained in step (1), add 68.75 mg of the MOF catalyst prepared in Example 1, mix them evenly, and obtain a mixed solution.

[0051] (3) The mixed solution obtained in step (2) was subjected to electron beam irradiation with β rays at a dose rate of 64800 kGy / h. The temperature during irradiation was 10℃ and the humidity was 60%.

[0052] Samples were taken every 15 kGy up to 150 kGy. The sample solutions were analyzed using a UV spectrophotometer, and the degradation efficiency of Rhodamine B organic pollutants was recorded. The results are shown in Table 3.

[0053] Table 3 Irradiation test results of Example 4

[0054] Irradiation dose (kGy) Rhodamine B degradation efficiency (%) 0 0 15 24 30 35 45 65 60 83 75 91 90 92 105 94 120 98 135 98 150 98

[0055] Table 3 shows that when the irradiation dose reaches 120 kGy, the degradation efficiency of Rhodamine B has reached 98%. Further increasing the irradiation dose will not increase the degradation efficiency of Rhodamine B.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for degrading organic pollutants using MOF catalysts in conjunction with electron beam irradiation, characterized in that, Includes the following steps: (1) Rhodamine B is reacted with deionized water to form a saturated solution, thereby preparing an aqueous solution of Rhodamine B; the mass concentration of the aqueous solution of Rhodamine B is 100-1000 mg / L; (2) Add a metal-organic framework material as a catalyst to the Rhodamine B aqueous solution obtained in step (1), mix thoroughly, and obtain a mixed solution; the mass concentration of the metal-organic framework material in the mixed solution is 2.75 g / L, and the metal-organic framework material is in the form of Fe 2+ As a metal source, Fe in the mixed solution 2+ The concentration was 400 mmol / L; (3) The mixed solution obtained in step (2) is subjected to electron beam irradiation to degrade the organic pollutant Rhodamine B; In step (2), the metal-organic framework material is prepared by dissolving FeSO4·7H2O, Fe(NO3)3·9H2O, H4ABTC and CH3COOH in DMF to obtain a mixed metal salt solution; transferring the mixed metal salt solution to a Teflon container, then placing it in an oven and heating it at 150°C for 24 hours; washing the resulting solid precipitate three times with ethanol, and finally drying it at 80°C for 12 hours to obtain the metal-organic framework material. The molar concentrations of FeSO4·7H2O, Fe(NO3)3·9H2O, H4ABTC, and CH3COOH in the mixed metal salt solution were all 100 mmol / L. In step (3), the dose of electron beam irradiation is 15 to 210 kGy; In step (3), the temperature of the electron beam irradiation is 0 to 10°C; In step (3), the humidity of the electron beam irradiation is 30-80%; In step (3), the electron beam radiation utilizes β rays as an energy source; The irradiation dose rate of the β rays is 64800 kGy / h.