Method for degrading organic pollutants through cooperation of MOF catalyst and electron beam irradiation technology

Abstract

The invention belongs to the technical field of sewage treatment, and particularly relates to a method for degrading organic pollutants by an MOF catalyst in cooperation with an electron beam irradiation technology, and the method comprises the following steps: (1) enabling rhodamine B and deionized water to form a saturated solution, and preparing a rhodamine B aqueous solution; (2) adding a metal organic framework material as a catalyst into the rhodamine B aqueous solution prepared in the step (1), and uniformly mixing to prepare a mixed solution; and (3) carrying out electron beam radiation on the mixed solution prepared in the step (2) to degrade the rhodamine B organic pollutant. The method has the beneficial effects that the method is carried out at low temperature, the process is simple, the controllability is relatively high, and the degradation rate advantage is very obvious; the degradation efficiency is very high in the process of treating high-concentration pollutants; the introduced catalyst not only can provide high-concentration Fe < 2 + >, but also can directly perform solid-liquid separation after degradation is finished, so that secondary pollution of the catalyst is avoided, and the sewage treatment cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and particularly relates to a method for degrading organic pollutants by using a MOF catalyst in combination with electron beam irradiation technology. Background Art

[0002] Organic sewage generated in industrial and domestic activities has become a thorny problem in environmental governance due to its complex composition, high pollution load, and treatment difficulty. Such sewage contains a wide variety of pollutants, which may include heavy metals, aromatic compounds, sulfides, nitrides, and other difficult-to-degrade and toxic chemical components, posing a threat to the ecosystem and human health. At the same time, its chemical oxygen demand (COD) even reaches more than 100,000 ppm in the wastewater of some industries, far exceeding the natural purification capacity of water bodies. Therefore, the full treatment of sewage is crucial. First, preliminary treatment is carried out through physical and chemical methods to reduce toxicity and improve biodegradability, and then a variety of advanced processes are combined to achieve efficient removal and purification, thereby reducing its harm to the environment. Currently, there are mainly three types of treatment technologies for 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, anaerobic-aerobic combined treatment).

[0003] Although the current physical, chemical, and biological treatment technologies have their own characteristics in the treatment of organic wastewater, there are also some common problems that limit their application and efficiency. Especially when facing high-concentration and complex-component organic pollutants, they often show limitations, as follows: the treatment efficiency is greatly affected by the types and concentrations of pollutants; some methods will produce secondary pollution, such as the residues of coagulants or the by-products of chemical reagents; the operating costs are relatively high, such as membrane separation, electrochemistry, and continuous aeration processes; at the same time, they have high requirements for equipment, operating conditions, and operations, and are easily affected by fluctuations in the properties of wastewater. These technologies generally have the problem of insufficient treatment depth when dealing with such high-concentration organic matters, and often need to be used in combination with multiple processes to achieve the ideal treatment effect. Generally speaking, how to improve the treatment efficiency, reduce costs, and reduce secondary pollution are the common challenges faced by these methods. Summary of the Invention

[0004] The present invention aims at the above problems and provides a method for degrading organic pollutants by using a MOF catalyst in combination with electron beam irradiation technology.

[0005] The present invention relates to a method for degrading organic pollutants by using a MOF catalyst in combination with electron beam irradiation technology, comprising the following steps: (1) Forming a saturated solution of rhodamine B and deionized water to obtain an aqueous solution of rhodamine B; (2) Add a metal-organic framework material as a catalyst to the rhodamine B aqueous solution prepared in step (1), mix evenly to obtain a mixed solution; (3) Perform electron beam irradiation on the mixed solution prepared in step (2) to degrade the rhodamine B organic pollutant.

[0006] Preferably, in step (1), the mass concentration of the rhodamine B aqueous solution is 100 - 1000 mg / L.

[0007] 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 uses Fe 2+ as the metal source, and the concentration of Fe 2+ in the mixed solution is 400 mmol / L.

[0008] Preferably, in step (2), the preparation method of the metal-organic framework material is as follows: Dissolve FeSO 4 ·7H 2 O, Fe(NO 3 ) 3 ·9H 2 O, H 4 ABTC and CH 3 COOH in DMF to obtain a mixed metal salt solution; transfer the mixed metal salt solution to a Teflon container, then place it in an oven and heat at 150 °C for 24 h; wash the obtained solid precipitate with ethanol 3 times, and finally dry it at 80 °C for 12 h to prepare the metal-organic framework material.

[0009] Preferably, the molar concentration of FeSO 4 ·7H 2 O, Fe(NO 3 ) 3 ·9H 2 O, H 4 ABTC and CH 3 COOH in the mixed metal salt solution is 100 mmol / L each.

[0010] Preferably, in step (3), the dose of the electron beam irradiation is 15 - 210 kGy.

[0011] Preferably, in step (3), the temperature of the electron beam irradiation is 0 - 10 °C.

[0012] Preferably, in step (3), the humidity of the electron beam irradiation is 30 - 80%.

[0013] Preferably, in the step (3), the electron beam radiation uses β-rays as the energy source.

[0014] Preferably, the irradiation dose rate of the β-rays is 64800 kGy / h.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are as follows: (1) The method for degrading organic pollutants by the MOF catalyst in cooperation with the electron beam irradiation technology can be carried out at low temperature, has a simple process, strong controllability and an obvious degradation rate advantage; (2) The method for degrading organic pollutants by the MOF catalyst in cooperation with the electron beam irradiation technology shows very high degradation efficiency in the process of treating high-concentration pollutants; (3) In the method for degrading organic pollutants by the MOF catalyst in cooperation with the electron beam irradiation technology, the introduced catalyst can not only provide a high concentration of Fe 2+ , but also directly carry out solid-liquid separation after the degradation, without causing secondary pollution of the catalyst and reducing the cost of sewage treatment; (4) In the method for degrading organic pollutants by the MOF catalyst in cooperation with the electron beam irradiation technology, the radiation sources are all proposed on the basis of industrialization, and the industrialization advantage is obvious. Detailed implementation manners

[0016] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described below with reference to the embodiments.

[0017] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the present invention is not limited by the specific embodiments disclosed in the following specification.

[0018] Example 1 Preparation of metal-organic framework material (MOF catalyst): Dissolve 278 g (1 mol) of FeSO 4 ·7H 2 O, 404 g (1 mol) of Fe(NO 3 ) 3 ·9H 2 O, 358.3 g (1 mol) of H 4 ABTC and 60 g (1 mol) of CH 3 COOH in 10 ml of DMF to obtain a mixed metal salt solution; transfer the mixed metal salt solution to a Teflon container, then place it in an oven and heat it at 150 °C for 24 h; wash the obtained solid precipitate with ethanol 3 times, and finally dry it at 80 °C for 12 h to prepare the metal-organic framework material.

[0019] Example 2 A method for degrading organic pollutants by using a MOF catalyst in combination with electron beam irradiation technology, comprising the following steps: (1) A saturated solution is formed by mixing rhodamine B with deionized water, 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 are prepared respectively.

[0020] (2) Take two portions of 25 ml of each concentration of the rhodamine B aqueous solution prepared in step (1), one portion as a control group and the other as an experimental group. Add 68.75 mg of the MOF catalyst prepared in Example 1 to the rhodamine B aqueous solutions of each concentration in the experimental group, mix well, and prepare a mixed solution.

[0021] (3) The control group solution and the experimental group mixed solution prepared in step (2) are respectively irradiated with β-rays at a dose rate of 64800 kGy / h. The temperature during irradiation is 8 °C and the humidity is 40%.

[0022] Use an ultraviolet spectrophotometer to detect the sample solution, and record the degradation efficiency of the rhodamine B organic pollutant at the degradation equilibrium. The results are shown in Table 1.

[0023] Table 1 Irradiation test results of Example 2 Concentration of Rhodamine B aqueous solution (mg / L) Irradiation dose at degradation equilibrium (kGy) Irradiation degradation efficiency (control group) (%) Irradiation and introduction of catalyst degradation efficiency (experimental group) (%) 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 It can be seen from Table 1 that compared with the degradation of rhodamine B only by irradiation, for the rhodamine B aqueous solution with the same concentration, the degradation efficiency of the method of irradiation combined with the MOF catalyst is higher, and the degradation efficiency for the high-concentration rhodamine B aqueous solution is also high, indicating that there is a synergistic effect between electron beam irradiation and the MOF catalyst, which can improve the degradation efficiency of rhodamine B.

[0024] Example 3 A method for degrading organic pollutants by using a MOF catalyst in combination with electron beam irradiation technology, comprising the following steps: (1) A saturated solution is formed by mixing rhodamine B with deionized water, and an aqueous solution of rhodamine B with a mass concentration of 500 mg / L is prepared.

[0025] (2) Take 5 portions of 25 ml of the rhodamine B aqueous solution prepared in step (1), and add 68.75 mg of the MOF catalyst recycled 1 - 5 times (after the used MOF catalyst undergoes solid-liquid separation, the solid is washed with ethanol and dried for reuse), mix well, and prepare a mixed solution.

[0026] (3)The mixed solution prepared in step (2) is irradiated with β-rays at a dose rate of 64800 kGy / h by electron beam. The temperature during irradiation is 10 °C and the humidity is 60%.

[0027] The sample solution is detected by an ultraviolet spectrophotometer, and the degradation efficiency of the rhodamine B organic pollutant at the degradation equilibrium is recorded. The results are shown in Table 2.

[0028] Table 2 Irradiation test results of Example 3 Group Number of cycles of MOF catalyst 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 It can be seen from Table 2 that after the MOF catalyst is recycled 5 times and combined with electron beam irradiation, it still has a good degradation effect on rhodamine B.

[0029] Example 4 A method for degrading organic pollutants by a MOF catalyst in combination with an electron beam irradiation technology includes the following steps: (1)Rhodamine B and deionized water are formed into a saturated solution to prepare a rhodamine B aqueous solution with a mass concentration of 500 mg / L respectively.

[0030] (2)Take 11 portions of 25 ml of the rhodamine B aqueous solution prepared in step (1), and add 68.75 mg of the MOF catalyst prepared in Example 1 respectively. Mix evenly to obtain a mixed solution.

[0031] (3)The mixed solution prepared in step (2) is irradiated with β-rays at a dose rate of 64800 kGy / h by electron beam. The temperature during irradiation is 10 °C and the humidity is 60%.

[0032] Samples are taken once every 15 kGy until 150 kGy. The sample solution is detected by an ultraviolet spectrophotometer, and the degradation efficiency of the rhodamine B organic pollutant is recorded. The results are shown in Table 3.

[0033] Table 3 Irradiation test results of Example 4 Irradiation dose (kGy) Degradation efficiency of Rhodamine B (%) 0 0 15 24 30 35 45 65 60 83 75 91 90 92 105 94 120 98 135 98 150 98 It can be seen from Table 3 that when the irradiation dose reaches 120 kGy, the degradation efficiency of rhodamine B has reached 98%. Continuing to increase the irradiation dose, the degradation efficiency of rhodamine B no longer increases.

[0034] The above is only the preferred embodiments of the present invention, and it is not a limitation of the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, as long as it does not depart from the technical solution content of the present invention, any simple modification and equivalent change made to the above embodiments based on the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A method for degrading organic pollutants using MOF catalyst in conjunction with electron beam irradiation technology, characterized in that: The following steps are involved: (1) forming a saturated solution of rhodamine B and deionized water to obtain a rhodamine B aqueous solution; (2) adding a metal organic framework material as a catalyst to the Rhodamine B aqueous solution obtained in step (1), and mixing them evenly to obtain a mixed solution; (3) The mixed solution obtained in step (2) is subjected to electron beam irradiation to degrade the organic pollutant Rhodamine B.

2. The method for degrading organic pollutants using MOF catalyst in cooperation with electron beam irradiation technology according to claim 1, characterized in that: In the step (1), the mass concentration of the Rhodamine B aqueous solution is 100 to 1000 mg / L.

3. The method for degrading organic pollutants using MOF catalyst in cooperation with electron beam irradiation technology according to claim 1, characterized in that: In the 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 Fe 2+ As the metal source, the mixed solution contains Fe 2+ The concentration is 400mmol / L.

4. The method for degrading organic pollutants using MOF catalyst in cooperation with electron beam irradiation technology according to claim 1, characterized in that: In the step (2), the preparation method of the metal organic framework material is: 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 hours; the obtained solid precipitate was washed three times with ethanol, and finally dried at 80°C for 12 hours to obtain a metal organic framework material.

5. The method for degrading organic pollutants using MOF catalyst in cooperation with electron beam irradiation technology according to claim 4, characterized in that: The molar concentrations of FeSO4·7H2O, Fe(NO3)3·9H2O, H4ABTC and CH3COOH in the mixed metal salt solution are all 100 mmol / L.

6. The method for degrading organic pollutants using MOF catalyst in cooperation with electron beam irradiation technology according to claim 1, characterized in that: In the step (3), the dose of the electron beam irradiation is 15 to 210 kGy.

7. The method for degrading organic pollutants using MOF catalyst in cooperation with electron beam irradiation technology according to claim 1, characterized in that: In the step (3), the temperature of the electron beam irradiation is 0 to 10°C.

8. The method for degrading organic pollutants using MOF catalyst in cooperation with electron beam irradiation technology according to claim 1, characterized in that: In the step (3), the humidity of the electron beam irradiation is 30 to 80%.

9. The method for degrading organic pollutants using MOF catalyst in cooperation with electron beam irradiation technology according to claim 1, characterized in that: In the step (3), the electron beam radiation utilizes β rays to provide an energy source.

10. The method for degrading organic pollutants using MOF catalyst in cooperation with electron beam irradiation technology according to claim 9, characterized in that: The irradiation dose rate of the beta ray is 64800 kGy / h.