Iron-manganese complex graphene carbon catalyst supported on zeolite, preparation and application thereof

Abstract

The application discloses an iron-manganese complex graphene carbon catalyst supported on a zeolite, and a preparation and application thereof, and belongs to the technical field of water treatment. The catalyst is a GC@Mn-Fe3O4 / Zeolite catalyst, which is made of nitrogen-doped graphene carbon, Fe3O4, Mn3O4 and a zeolite, and a preparation method thereof is provided. The GC@Mn-Fe3O4 / Zeolite catalyst prepared in the application can drive the metabolism of microorganisms in water to antibiotics, and effectively removes three mixed antibiotics, i.e., ciprofloxacin, sulfamethoxazole and tetracycline, in water under the condition that no external energy is input, and the removal rate can reach more than 95%. In addition, the iron-manganese complex graphene carbon catalyst is supported on the zeolite, so that the stability of the catalyst is improved, and the catalyst has a good application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water treatment, in particular to an iron-manganese complex type graphene carbon catalyst loaded on zeolite and preparation and application thereof. BACKGROUND

[0002] At present, antibiotics used in various fields will eventually enter water, and antibiotics can induce the formation of superbugs and antibiotic resistance genes, thereby seriously threatening human health and ecological environment, so efficient removal of antibiotics in water is crucial to prevent the spread of antibiotics to the environment and reduce the risk of biological exposure.

[0003] At present, biological treatment technology still occupies a dominant position in sewage treatment plants, however, due to the difficulty of degradation and antibacterial property of antibiotics, the removal effect of traditional biological treatment on antibiotics in water is not ideal. In addition, traditional biological treatment usually needs additional carbon source, aeration and other treatments, which has certain limitations.

[0004] Based on the above, a scheme for realizing the treatment of antibiotics in water without additional carbon source, aeration and other means is proposed. SUMMARY

[0005] The purpose of the present application is to provide an iron-manganese complex type graphene carbon catalyst loaded on zeolite and preparation and application thereof, so as to solve the problems in the background art.

[0006] To achieve the above purpose, the present application provides an iron-manganese complex type graphene carbon catalyst loaded on zeolite, which is GC@Mn-Fe3O4 / Zeolite catalyst, and the catalyst is composed of nitrogen-doped graphene carbon, Fe3O4, Mn3O4 and zeolite.

[0007] The present application also provides a preparation method of the above catalyst, comprising the following steps:

[0008] S1, adding carbon source and nitrogen source into ultrapure water and stirring to obtain suspension A;

[0009] S2, drying the suspension A in an oven to obtain a precursor B, and placing the precursor B in a tube furnace and pyrolyzing under nitrogen atmosphere to obtain GC;

[0010] S3, placing ethylene glycol in a beaker, adding iron chloride hexahydrate, manganese chloride tetrahydrate, zeolite and GC, and stirring to obtain suspension C;

[0011] S4, adding ammonium acetate to the suspension C and stirring vigorously to form uniformly dispersed precursor D;

[0012] S5, transferring the precursor D into a polytetrafluoroethylene liner to carry out a hydrothermal reaction, and after natural cooling, washing and vacuum drying to obtain the GC@Mn-Fe3O4 / Zeolite catalyst.

[0013] Preferably, in S1, the ultrapure water is 40-60 mL, the carbon source is 15-20 g, and the nitrogen source is 3-4 g.

[0014] Preferably, in S1, the carbon source is one or more of sawdust, pomelo peel, garlic skin, corn straw and rice straw; and the nitrogen source is one or more of melamine, dicyanediamine, 2-methylimidazole and urea.

[0015] Preferably, in S2, the drying temperature is 70-90℃, the pyrolysis temperature is 600-800℃, the pyrolysis time is 3-5h, and the heating rate of the pyrolysis process is 5-10℃ / min.

[0016] Preferably, in S3, the volume of ethylene glycol is 45-50 mL, the amount of substance of iron chloride hexahydrate is 18-20 mmol, the amount of substance of manganese chloride tetrahydrate is 2-3.3 mmol, the mass of zeolite is 5-10 g, and the mass of GC is 1-1.5 g.

[0017] Preferably, in S4, the amount of substance of ammonium acetate is 126-132 mmol.

[0018] Preferably, in S5, the hydrothermal reaction time is 10-12h, the temperature is 180-200℃, and the vacuum drying temperature is 60-80℃.

[0019] The application also provides an application of the iron-manganese complex graphene carbon catalyst loaded on zeolite, and the catalyst is applied to removal of antibiotics in water.

[0020] Preferably, in the process of removing antibiotics in water, the catalyst is used as a filler to build an upflow biological filter reactor, mixed antibiotic wastewater is pumped into the upflow biological filter reactor, and water microorganisms are driven to metabolize antibiotics, so that the antibiotics are removed.

[0021] Preferably, the mixed antibiotics include ciprofloxacin, sulfamethoxazole and tetracycline, and the water is municipal wastewater.

[0022] Preferably, the water flow direction of the upflow biological filter reactor is from bottom to top.

[0023] Therefore, the iron-manganese complex graphene carbon catalyst loaded on zeolite, and the preparation and application thereof have the following beneficial effects:

[0024] (1) The GC@Mn-Fe3O4 / Zeolite catalyst prepared by the method has the advantages that the catalyst is a black solid and has a microsphere structure, the Mn-Fe3O4 microspheres are tightly covered by the graphene-like carbon, the graphene-like carbon is tightly connected with the manganese doping through complexation, the catalytic performance is more stable and is not easy to be dissolved in the water body, the catalyst material has a large specific surface area, more reaction active sites are exposed, the interface contact with antibiotic molecules and microorganisms is promoted, the extracellular electron transfer process is strengthened, and rapid degradation of the antibiotic is realized.

[0025] (2) In the catalyst prepared by the method, the Mn-Fe3O4 microspheres are wrapped in the graphene-like carbon and mainly play a role in regulating the internal electron distribution of the material; the manganese doping can regulate the electronic structure of the ferroferric oxide, so that the graphene-like carbon is complexed with iron and manganese, and the electronic polarization distribution is induced; the iron ions and the manganese ions serve as active centers and do not directly react with the antibiotic, so that the iron and manganese are non-consumable and are little dissolved; in addition, the iron and manganese elements are strong affinity elements for microorganisms, and can promote the metabolic growth of the microorganisms.

[0026] (3) The GC@Mn-Fe3O4 / Zeolite catalyst has a strong enough electric field on the surface, can drive the metabolism of the antibiotic of the microorganism in the water, strengthen the extracellular electron transfer process, and efficiently remove three mixed antibiotics of the ciprofloxacin (CIP), sulfamethoxazole (SMX) and tetracycline (TC) in the water; the removal rate of the various antibiotics can reach more than 95% when the system is stable; without additional carbon source and aeration, the antibiotic in the wastewater can be efficiently treated at low energy consumption, and the cost of antibiotic wastewater treatment is reduced.

[0027] The technical solutions of the present application will be further described in detail below with the aid of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is the XRD spectrum of the catalyst in Example 1 of the present application;

[0029] Figure 2 is the SEM image of the catalyst in Example 1 of the present application at different magnifications, wherein a is 1 μm and b is 200 nm;

[0030] Figure 3 is the transmission electron microscope element scanning image of the catalyst in Example 1 of the present application;

[0031] Figure 4 is the HRTEM image of the catalyst in Example 1 of the present application;

[0032] Figure 5 is the activity evaluation result graph of the catalyst in the application example 1 for degrading the antibiotic. DETAILED DESCRIPTION

[0033] The technical solutions of the present application will be further described below with the drawings and examples.

[0034] To make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0035] Embodiment 1

[0036] In this embodiment, a GC@Mn-Fe3O4 / Zeolite catalyst is prepared, and the specific steps are as follows:

[0037] S1, 50 mL of ultrapure water is measured in a beaker, and 15 g of a mixture of wood chips and pomelo peel is added as a carbon source, and 3 g of melamine is added as a nitrogen source, and stirring is performed to form a suspension A;

[0038] S2, the suspension A is placed in an oven and dried at 80°C to obtain a precursor B, and then the dried precursor B is placed in a tube furnace and pyrolyzed at 600°C for 4 h in a nitrogen atmosphere to obtain GC;

[0039] S3, 45.5 mL of ethylene glycol is measured in a beaker, and 4.925 g of iron trichloride hexahydrate, 0.413 g of manganese chloride tetrahydrate, 5.129 g of zeolite and 1.125 g of GC are added, and stirring is performed for 30 min to form a suspension C;

[0040] S4, 10.239 g of ammonium acetate is added to the suspension C, and stirring is performed for 30 min to form a uniformly dispersed precursor D;

[0041] S5, the precursor D is transferred to a polytetrafluoroethylene gasket, and a hydrothermal reaction is performed at 200°C for 2 h, and after natural cooling, washing and vacuum drying at 60°C, a GC@Mn-Fe3O4 / Zeolite catalyst is obtained.

[0042] The catalyst prepared in Embodiment 1 is characterized, as shown in Figures 1-4 , and Figure 1 It can be seen that, compared with the standard card, the phase composition of the GC@Mn-Fe3O4 / Zeolite catalyst includes Fe3O4, carbon and Zeolite.

[0043] From Figure 2 It can be observed that the Mn-Fe3O4 small balls are tightly coated by the graphenelike carbon. After Figure 3 analysis, it is found that the catalyst is composed of C, N, O, Fe and Mn. Figure 4It is shown that the catalyst contains Fe3O4, Mn3O4, carbon and Zeolite.

[0044] Example 2

[0045] The preparation steps of this example are the same as those of Example 1, except that the amount of carbon source is 20 g, the amount of nitrogen source is 4 g, the amount of ultrapure water is 60 mL, and the amount of GC is 1.5 g.

[0046] Example 3

[0047] The preparation steps of this example are the same as those of Example 1, except that the amount of carbon source is 18 g, the amount of nitrogen source is 3.5 g, the amount of ultrapure water is 55 mL, and the amount of GC is 1 g.

[0048] Application Example 1

[0049] The GC@Mn-Fe3O4 / Zeolite catalyst prepared in Example 1 is applied to drive microbial degradation of antibiotics in water, as follows:

[0050] 13.7 g of the catalyst prepared in Example 1 is filled in a reaction column to construct an upflow biological filter reactor, and 1 mg / L of mixed antibiotic wastewater containing ciprofloxacin, sulfamethoxazole and tetracycline is pumped into the reactor by a peristaltic pump, with the water flow direction being from bottom to top and the retention time being 30 min.

[0051] The above scheme is used for continuous degradation experiment of antibiotics in water, and the degradation rate of antibiotics is shown in Table 1. Figure 5 The results show that in the first 11 days, the removal rate of antibiotics is low, and in this process, the adsorption process of antibiotics occurs; after 11 days, the degradation performance increases obviously, and reaches more than 95% around the 20th day, and after 20 days, the degradation rate fluctuates around 95%, which indicates that the catalyst promotes the metabolism of antibiotics by microorganisms, and realizes the rapid degradation of mixed antibiotics.

[0052] Therefore, the iron-manganese complex graphene carbon catalyst loaded on zeolite and its preparation and application, the prepared GC@Mn-Fe3O4 / Zeolite catalyst can drive the metabolism of antibiotics by microorganisms in water, effectively remove three kinds of mixed antibiotics of ciprofloxacin, sulfamethoxazole and tetracycline in water without external energy input, and the removal rate can reach more than 95%; secondly, the iron-manganese complex graphene carbon catalyst is loaded on zeolite, which improves the stability of the catalyst and has good prospects for practical application.

[0053] It should be pointed out finally that the above examples are only used to illustrate the technical solutions of the present application but not to limit it, and although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can still be modified or replaced equivalently, and these modifications or equivalent replacements should not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. An iron-manganese complex graphene-like carbon catalyst supported on zeolite, characterized in that: the catalyst is GC@Mn-Fe3O4 / Zeolite catalyst, and the catalyst is composed of nitrogen-doped graphene-like carbon GC, Fe3O4, Mn3O4 and zeolite; a preparation method of the catalyst comprises the following steps: S1, adding a carbon source and a nitrogen source into ultrapure water to obtain a suspension A by stirring; S2, drying the suspension A in an oven to obtain a precursor B, and pyrolyzing the precursor B in a tube furnace under a nitrogen atmosphere to obtain the nitrogen-doped graphene-like carbon GC; S3, placing ethylene glycol in a beaker, adding iron chloride hexahydrate, manganese chloride tetrahydrate, zeolite and the nitrogen-doped graphene-like carbon GC, and stirring to obtain a suspension C; S4, adding ammonium acetate into the suspension C to form a uniformly dispersed precursor D by vigorous stirring; and S5, transferring the precursor D into a polytetrafluoroethylene gasket to perform a hydrothermal reaction, wherein the hydrothermal reaction time is 10-12 h, and the temperature is 180-200 ℃, and after natural cooling, the GC@Mn-Fe3O4 / Zeolite catalyst is obtained by washing and vacuum drying. a preparation method of the catalyst comprises the following steps: S1, adding a carbon source and a nitrogen source into ultrapure water to obtain a suspension A by stirring; S2, drying the suspension A in an oven to obtain a precursor B, and pyrolyzing the precursor B in a tube furnace under a nitrogen atmosphere to obtain the nitrogen-doped graphene-like carbon GC; S3, placing ethylene glycol in a beaker, adding iron chloride hexahydrate, manganese chloride tetrahydrate, zeolite and the nitrogen-doped graphene-like carbon GC, and stirring to obtain a suspension C; S4, adding ammonium acetate into the suspension C to form a uniformly dispersed precursor D by vigorous stirring; and S5, transferring the precursor D into a polytetrafluoroethylene gasket to perform a hydrothermal reaction, wherein the hydrothermal reaction time is 10-12 h, and the temperature is 180-200 ℃, and after natural cooling, the GC@Mn-Fe3O4 / Zeolite catalyst is obtained by washing and vacuum drying. In the S1, the ultrapure water is 40-60 mL, the carbon source is 15-20 g, and the nitrogen source is 3-4 g. In the S1, the carbon source is one or more of sawdust, pomelo peel, garlic skin, corn stalks and rice straw; and the nitrogen source is one or more of melamine, dicyandiamide, 2-methylimidazole and urea. In the S2, the drying temperature is 70-90 ℃, the pyrolysis temperature is 600-800 ℃, the pyrolysis time is 3-5 h, and the heating rate in the pyrolysis process is 5-10 ℃ / min. In the S3, the volume of ethylene glycol is 45-50 mL, the amount of substance of iron chloride hexahydrate is 18-20 mmol, the amount of substance of manganese chloride tetrahydrate is 2-3.3 mmol, the mass of zeolite is 5-10 g, and the mass of GC is 1-1.5 g. In the S4, the amount of substance of ammonium acetate is 126-132 mmol. In the S5, the vacuum drying temperature is 60-80 ℃.

2. The method for preparing an iron-manganese complex graphene carbon catalyst supported on zeolite as described in claim 1, characterized in that, The catalyst is applied to removal of antibiotics in water. ​ ​ ​ ​ ​ 3. The process for the preparation of iron-manganese complexed graphene-like carbon catalyst supported on zeolite according to claim 2, characterized in that: ​ 4. The process for the preparation of iron-manganese complexed graphene-like carbon catalyst supported on zeolite according to claim 2, characterized in that: ​ 5. The process for the preparation of iron-manganese complexed graphene-like carbon catalyst supported on zeolite according to claim 2, characterized in that: ​ 6. The process for the preparation of iron-manganese complexed graphene-like carbon catalyst supported on zeolite according to claim 2, characterized in that: ​ 7. The method for preparing the iron-manganese complexed graphene-like carbon catalyst supported on zeolite according to claim 2, characterized in that: ​ 8. The process for the preparation of iron-manganese complexed graphene-like carbon catalyst supported on zeolite according to claim 2, characterized in that: ​ 9. Use of the iron-manganese complexed graphene-like carbon catalyst supported on zeolite according to claim 1, characterized in that: ​ 10. Use of the iron-manganese complexed graphene-like carbon catalyst supported on zeolite according to claim 9, characterized in that: In the process of removing antibiotics in water, the catalyst is used as a filler to build an up-flow biological filter reactor, mixed antibiotic wastewater is pumped into the up-flow biological filter reactor, and microorganisms in water are driven to metabolize antibiotics, so that the antibiotics are removed.

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