Red mud-based catalyst as well as preparation method and application thereof

Abstract

The invention provides a red mud-based catalyst as well as a preparation method and application thereof. The molecular formula of the red mud-based catalyst is RM-nZVI / Ni, the red mud-based catalyst is a reaction product of red mud, a Fe-containing compound and a Ni-containing compound in a solvent under the action of a reducing agent. The invention provides a red mud-based catalyst loaded with zero-valent iron and nickel bimetals, which is simple in synthesis process and low in cost. The catalyst has universality in the aspect of antibiotic polluted water treatment, is relatively efficient, and can realize double effects of waste utilization and pollution removal.

Description

Technical Field

[0001] The present invention relates to a red mud-based catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Red mud (RM) is a solid waste with a relatively high iron content and is a by-product of the alumina industry. For every 1 ton of alumina produced, 1-2 tons of red mud will be generated. Therefore, red mud has a huge stockpile, nearly 400 million tons globally, and is increasing at a rate of 0.175 tons per year. Currently, the main disposal method of red mud is to stack it in dams. However, red mud has characteristics such as strong alkalinity, small particle size, and radioactivity, which will cause a huge burden on environmental health and limit the development of the alumina industry. Therefore, it is extremely important to find a reliable and efficient method for red mud utilization. Currently, the comprehensive utilization of red mud has received extensive attention from many research teams at home and abroad.

[0003] Red mud has the characteristics of a large specific surface area and a high porosity, which is conducive to the adsorption of reactants / intermediates and is an ideal catalyst carrier. Moreover, red mud is rich in active metals such as Fe and Ti and is a suitable catalyst substrate. In recent years, many studies have applied red mud to the catalytic field. The concept of "treating waste with waste" is applied to the field of sewage treatment, and modified red mud is used to treat antibiotics in the environment. Research shows that antibiotics are overused and discharged in China, resulting in relatively high concentrations of antibiotics in hospitals and the environment, which may cause an increase in antibiotic resistance. Moreover, the metabolites of antibiotic drugs will threaten water safety after being discharged into the environment. Among them, sulfonamide antibiotics, as antibiotics widely used in the early stage, are found to have a relatively high concentration in water bodies. Sulfamethoxazole, as one of the representative antibiotics, is often used to study the performance of degradation materials. However, the traditional catalyst has a relatively high manufacturing cost. Using red mud as the catalyst substrate can realize the comprehensive utilization of red mud while reducing the cost of antibiotic degradation.

[0004] Advanced oxidation technologies (AOPs) generate highly oxidizing free radicals, which can mineralize organic matter or directly decompose it through oxidation to improve the biodegradability of pollutants. The Fenton oxidation system is a kind of advanced oxidation reaction (AOPs) and has characteristics such as high efficiency and low toxicity. Nano zero-valent iron has strong reducibility and can react with dissolved oxygen in water to generate H2O2, while being oxidized to Fe 2+ 2+. This reaction mechanism can reduce the usage amount of H2O2 and lower the cost input. Currently, many research reports have been published on Fe 0In the application of advanced oxidation processes, it has the characteristics of high efficiency, low cost, environmental friendliness, and recyclability. Nano zero-valent iron has been proven in many research reports to have good removal effects on many pollutants. However, due to its high reactivity and the characteristic that nano zero-valent iron is prone to agglomeration due to its strong magnetism, a single zero-valent iron material cannot achieve the expected effects in terms of long-term effectiveness, antioxidant properties, and removal ability. Summary of the Invention

[0005] To solve the above problems, the present invention provides a red mud-based catalyst, its preparation method, and application.

[0006] In the first aspect of the present invention, a red mud-based catalyst is provided. The catalyst includes zero-valent iron-nickel metal nanosheets and red mud, wherein the red mud is loaded on the zero-valent iron-nickel metal nanosheets.

[0007] According to some embodiments of the catalyst of the present invention, by weight percentage, the weight percentage content of Fe element in the catalyst is 40-60%, the weight percentage content of Ni element is 0.5-5%, the weight percentage content of Al element is 1-5%, and the weight percentage content of Si element is 10-25%.

[0008] In the second aspect of the present invention, a preparation method of a red mud-based catalyst is provided, including the following steps:

[0009] (1) Mix red mud, an Fe ion-containing compound, and a Ni ion-containing compound in a solvent to obtain a mixed solution;

[0010] (2) Add a reducing agent to the mixed solution and react to obtain the catalyst.

[0011] According to some embodiments of the preparation method of the present invention, in step (1), the water content of the red mud ≤ 5%, such as 5%, 4%, 3%, 2%, 1%, 0.8%, and the fineness of the red mud is 10-200 mesh, such as: 10 mesh, 50 mesh, 80 mesh, 100 mesh, 120 mesh, 200 mesh.

[0012] According to some embodiments of the preparation method of the present invention, the Fe ion-containing compound is selected from FeSO4 or its hydrate, FeCl2 or its hydrate, Fe2(SO4)3 or its hydrate, FeCl3 or its hydrate.

[0013] According to some embodiments of the preparation method of the present invention, the Ni ion-containing compound is selected from Ni(NO3)2 or its hydrate, NiCl2 or its hydrate, NiSO4 or its hydrate.

[0014] According to some embodiments of the preparation method of the present invention, the reducing agent is selected from KBH4 or NaBH4.

[0015] In some embodiments of the preparation method according to the present invention, the solvent is a mixture of ethanol and water.

[0016] In some embodiments of the preparation method according to the present invention, the volume ratio of ethanol to water is 1:(1 - 3), such as 1:1, 1:2, 1:3.

[0017] In some embodiments of the preparation method according to the present invention, the mass ratio of the Fe-containing ionic compound to the Ni-containing ionic compound is (25 - 100):1, such as 25:1, 30:1, 35:1, 50:1, 60:1, 75:1, 80:1, 90:1, 100:1.

[0018] In some embodiments of the preparation method according to the present invention, the molar ratio of the Fe-containing ionic compound to the Ni-containing ionic compound is (50 - 200):1, such as 50:1, 55:1, 70:1, 80:1, 100:1, 110:1, 120:1, 140:1, 150:1, 200:1.

[0019] In some embodiments of the preparation method according to the present invention, the mass ratio of the red mud to the Fe-containing ionic compound is 1:(2 - 4), such as 1:2, 1:3, 1:4.

[0020] In some embodiments of the preparation method according to the present invention, the mass ratio of the red mud to the Ni-containing ionic compound is 1:(0.04 - 0.08), such as 1:0.04, 1:0.05, 1:0.06, 1:0.08.

[0021] In some embodiments of the preparation method according to the present invention, the molar ratio of the Fe-containing ionic compound to the reducing agent is 1:(1.5 - 3), such as 1:1.5, 1:2.0, 1:2.5, 1:3.

[0022] In some embodiments of the preparation method according to the present invention, in step (2), the reducing agent is added in the form of an aqueous solution.

[0023] In some embodiments of the preparation method according to the present invention, the molar concentration of the reducing agent in the aqueous solution is 0.1 - 0.3 mol / L, such as 0.1 mol / L, 0.2 mol / L, 0.3 mol / L.

[0024] In some embodiments of the preparation method according to the present invention, the addition rate of the aqueous solution is 0.04 - 0.12 ml per second, such as 0.04 ml, 0.06 ml, 0.08 ml, 0.10 ml, 0.12 ml;

[0025] According to some embodiments of the preparation method of the present invention, the temperature of the reaction is 15 - 30 °C.

[0026] According to some embodiments of the preparation method of the present invention, the time of the reaction is 60 - 80 min.

[0027] In the third aspect of the present invention, there is provided an application of the catalyst described in the first aspect of the present invention or the catalyst described in the second aspect of the present invention in treating antibiotic - containing sewage.

[0028] According to some embodiments of the application of the present invention, the antibiotic is sulfamethoxazole, levofloxacin, norfloxacin, ciprofloxacin or tetracycline hydrochloride.

[0029] In the fourth aspect of the present invention, there is provided a method for treating antibiotic - containing sewage. Under acidic conditions, the catalyst described in the first aspect of the present invention or the catalyst obtained by the preparation method described in the second aspect of the present invention, hydrogen peroxide and antibiotic - containing sewage are mixed to degrade the antibiotic.

[0030] According to some embodiments of the treatment method of the present invention, when the content of the antibiotic in the antibiotic - containing sewage is 20 ppm, the dosage of the catalyst is 0.05 - 0.2 g / L, such as 0.05 g / L, 0.08 g / L, 0.10 g / L, 0.15 g / L, 0.20 g / L.

[0031] According to some embodiments of the treatment method of the present invention, when the content of the antibiotic in the antibiotic - containing sewage is 20 ppm, the dosage of H2O2 is 0.1 - 5 mM, such as 0.1 mM, 0.2 mM, 0.25 mM, 0.5 mM, 1 mM, 2 mM, 3 mM, 4 mM, 5 mM.

[0032] According to some embodiments of the treatment method of the present invention, the temperature of the reaction is 15 - 30 °C, and the time of the reaction is 10 - 30 min.

[0033] According to some embodiments of the treatment method of the present invention, the pH value of the acidic condition is pH ≤ 5;

[0034] According to some embodiments of the treatment method of the present invention, 0.5 - 1.5 mol / L of NaOH and 0.5 - 1.5 mol / L of HCl are used to adjust the pH of the reaction solution.

[0035] According to some embodiments of the treatment method of the present invention, the antibiotic - containing sewage does not contain HCO3 - and H2PO4 - .

[0036] The beneficial effects of the present invention are as follows: to provide a red mud-based catalyst loaded with zero-valent iron-nickel bimetal with a simple synthesis process and low cost. The catalyst has universality in the treatment of antibiotic-polluted water and is relatively efficient, and can achieve the dual effects of waste utilization and pollution removal. Description of the Drawings

[0037] Figure 1 It is the SEM diagram of the red mud sample used in the embodiment of the present invention;

[0038] Figure 2 is Figure 1 a partial enlarged view of the SEM diagram in

[0039] Figure 3 It is the XRD diagram of the red mud sample used in the embodiment of the present invention;

[0040] Figure 4 It is the SEM diagram of the catalyst described in Embodiment 1 of the present invention;

[0041] Figure 5 is Figure 4 a partial enlarged view of the SEM diagram in

[0042] Figure 6 It is the TEM structure diagram of the catalyst described in Embodiment 1 of the present invention;

[0043] Figure 7 It is the TEM element distribution characteristic diagram of the catalyst described in Embodiment 1 of the present invention;

[0044] Figure 8 It is the XRD diagram of the catalyst described in Embodiment 1 of the present invention. Detailed Embodiments

[0045] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in combination with embodiments and drawings. The specific embodiments described herein are only used to explain the present invention and do not constitute any limitation to the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concepts of the present disclosure. Such structures and technologies have also been described in many publications.

[0046] FeSO4·7H2O, Ni(NO3)2·6H2O, NaBH4, NaOH, HCl, EtOH, H2O2 (30% w / v), sulfamethoxazole (SMX), NaCl, NaHCO3, NaH2PO4, Na2SO4, NaNO3 used in the embodiments and comparative examples of the present invention are all purchased from Aladdin.

[0047] The red mud used in the examples and comparative examples of this application was collected from a certain red mud yard. After the fresh red mud was naturally air-dried, it was ground into powder, passed through a 100-mesh sieve, and sealed for later use. The SEM images of the collected samples are as shown in Figure 1 and Figure 2 shown, and the XRF of the collected samples is as shown in Figure 3 shown:

[0048] The XRF results of the components of the collected samples are shown in the following table:

[0049]

[0050] Preparation of the catalyst for Example 1

[0051] The catalyst was synthesized by the liquid-phase reduction method. 5 g of RM (naturally air-dried to a moisture content < 5% and passed through a 100-mesh sieve), 14.88 g of FeSO4·7H2O, and 0.2976 g of Ni(NO3)2·6H2O were added to a three-necked flask containing 300 ml of ethanol / water solution (1:2, vol / vol), and ultrasonic treatment was carried out for 30 minutes to make it uniformly dispersed. Nitrogen was continuously introduced into the solution (flow rate: 100 ml / min). Under the condition of mechanical stirring (600 r / min), 50 ml of an aqueous solution of 0.2 mol / L NaBH4 was slowly dropped into the solution at a rate of 1 - 2 drops per second (each drop is about 0.05 ml), and the reaction was carried out at 25 °C for 60 min. Finally, the sample was filtered, washed three times with water and anhydrous ethanol, and then dried overnight at 60 °C in a vacuum drying oven. The prepared catalyst was stored in vacuum to avoid oxidation before the reaction.

[0052] The reaction equations involved in the experiment are as follows:

[0053]

[0054]

[0055] Fe 0 +Ni 2+ →Fe 2+ +Ni 0

[0056] The surface morphology of the synthesized catalyst was observed using a field emission scanning electron microscope (FESEM, JSM-7800F, Japan), and the results are as shown in Figure 4 and Figure 5 shown:

[0057] The phase composition of the catalyst was analyzed by X-ray powder diffraction (XRD, Bruker D2 PHASER, Germany), and the results are as shown in Figure 8 shown. From Figure 8It can be seen that the composite material has a diffraction peak belonging to Fe at 44.6°. 0 The diffraction peak shown at 44.5° is consistent with the standard diffraction pattern of Ni 0 (JCPDS No. 45-1027). This indicates that: Ni 0 and nZVI were successfully synthesized.

[0058] From Figure 4 and Figure 5 it can be seen that the modified catalyst material shows nanosheets. The surface of the nanosheets is smooth, but there are attached protrusions of particles, presumably red mud attached to the zero-valent metal nanosheets.

[0059] The transmission electron microscope (TEM) was used to determine the structural and elemental distribution characteristics of the catalyst material. The results are as shown in Figure 6 and Figure 7 . From Figure 6 and Figure 7 it can be seen that the elements Fe, Ni and the Ca, Al, Si elements originally contained in the red mud are relatively evenly distributed, indicating that RM was successfully loaded on the zero-valent metal iron-nickel nanosheets.

[0060] Preparation of the catalyst in Example 2

[0061] The catalyst was synthesized by the liquid-phase reduction method. 5 g of RM (naturally air-dried to a moisture content < 5% and passed through a 100-mesh sieve), 14.59 g of FeCl3·6H2O, and 0.2976 g of Ni(NO3)2·6H2O were added to a three-necked flask containing 300 ml of an ethanol / water solution (1:2, vol / vol). It was ultrasonically treated for 30 minutes to make it evenly dispersed. Nitrogen was continuously passed through the solution (flow rate: 100 ml / min). Under the condition of mechanical stirring (600 r / min), 50 ml of an aqueous solution of 0.2 mol / L NaBH4 was slowly dropped into the solution at a rate of 1-2 drops per second (each drop is about 0.05 ml), and the reaction was carried out at 25 °C for 60 min. Finally, the sample was filtered, washed three times with water and absolute ethanol, and then dried overnight at 60 °C in a vacuum drying oven. The prepared catalyst was stored in vacuum to avoid oxidation before the reaction.

[0062] Preparation of the catalyst in Example 3

[0063] The catalyst was synthesized by the liquid-phase reduction method. 5 g of RM (naturally air-dried until the moisture content < 5% and passed through a 100-mesh sieve), 9.92 g of FeSO4·7H2O, and 0.1984 g of Ni(NO3)2·6H2O were added to a three-necked flask containing 300 ml of an ethanol / water solution (1:1, vol / vol), and ultrasonic treatment was carried out for 30 minutes to achieve uniform dispersion. Nitrogen was continuously introduced into the solution (flow rate: 100 ml / min). Under the condition of mechanical stirring (700 r / min), 50 ml of an aqueous solution of 0.2 mol / L KBH4 was slowly dropped into the solution at a rate of 1 - 2 drops per second (each drop was approximately 0.05 ml), and the reaction was carried out at 25 °C for 60 min. Finally, the sample was filtered, washed three times with water and absolute ethanol, and then dried overnight at 60 °C in a vacuum drying oven. The prepared catalyst was stored in vacuum to avoid oxidation before the reaction.

[0064] 1. Catalyst performance test

[0065] All batches of experiments were carried out in a 100-ml beaker, placed on a horizontal oscillator, and reacted at a rotation speed of 100 rpm for 30 min at room temperature (25 °C). First, 50 ml of the prepared 20-ppm target pollutant was taken into a 100-ml beaker. A certain amount of the catalyst was weighed and added to the beaker, and the pH was adjusted to the set value using 1.0 mol / L NaOH and 1.0 mol / L HCl, and measured with a pH meter. After adsorption for a period of time, the required amount of H2O2 was added to the above aqueous solution to trigger the degradation reaction. 1 ml was taken out from the beaker at preset time intervals and added to an excess of tert-butanol, and after filtration using a 0.22-μm organic syringe filter, it was added to a 2-ml liquid injection vial for subsequent analysis and determination. After the reaction, the catalyst material was collected using a magnet.

[0066] 1.1 To ensure that the catalytic performance of the catalyst material (RM-nZVI / Ni) of this application plays a major role, the degradation effects of different systems (RM-nZVI / Ni, H2O2, RM / H2O2, RM-nZVI / Ni / H2O2) on 20-ppm SMX were investigated at pH = 3. The results are shown in Table 1:

[0067] Table 1

[0068]

[0069] It can be seen from Table 1 that when the catalyst and H2O2 do not coexist, the concentration of SMX hardly decreases. For the process using H2O2 alone, after 30 min of reaction, the removal efficiency of SMX is only 0.87%, indicating that the oxidation ability of H2O2 alone for SMX is weak.

[0070] The removal efficiency of SMX by untreated RM powder under the action of H2O2 within 30 min was only 9.75%, which might be due to the low adsorption or activation degree of RM to molecular oxygen in aqueous solution. However, when RM-nZVI / Ni was used as the activator of H2O2, the removal efficiency of SMX increased significantly, and complete degradation could be achieved within 30 min.

[0071] 1.2 Influence of different catalyst dosages on the degradation effect of SMX

[0072] The catalyst dosage and the degradation effect of SMX obtained in Example 1 are shown in Table 2:

[0073] Table 2

[0074]

[0075] It can be seen from Table 2 that the more the catalyst dosage, the faster the reaction. However, considering the cost, the preferred catalyst dosage is 0.1 g / L.

[0076] 1.3 Influence of different H2O2 dosages on the degradation effect of SMX

[0077] The H2O2 dosage and the degradation effect of SMX are shown in Table 3:

[0078] Table 3

[0079]

[0080] It can be seen from Table 3 that the more the H2O2 dosage, the faster the reaction. However, considering the cost, the preferred H2O2 dosage is 3 mM.

[0081] 1.4 Influence of different pH values during the degradation process on the degradation effect of SMX

[0082] The pH value and the degradation effect of SMX are shown in Table 4:

[0083] Table 4

[0084]

[0085] It can be seen from Table 4 that the RM-nZVI / Ni / H2O2 system is effective in degrading SMX under acidic conditions (pH = 3 - 5). As the acidity weakens, the degradation efficiency decreases, and SMX hardly degrades under neutral and alkaline conditions. Therefore, in practical applications, the wastewater needs to be adjusted to acidic for use. Considering the degradation effect and economic factors, through the above analysis, the optimal conditions were selected for subsequent experiments. That is, in an environment with pH = 3, 0.1 g / L RM-nZVI / Ni was weighed, and 3 mM H2O2 was added to the system to activate the experiment. Under these experimental conditions, it only takes 20 minutes to completely degrade 20 ppm SMX. Compared with other studies, this system requires less H2O2 and catalyst dosage, and the reaction time is shorter, which is more economical and efficient.

[0086] 1.5 Influence of anions contained in the target pollutant on the degradation effect of SMX

[0087] 10 mM Cl-, HCO3-, H2PO4-, SO42-, and NO3- were respectively added to the target pollutant, and the influence on the degradation effect of SMX is shown in Table 5:

[0088] Table 5

[0089]

[0090]

[0091] It can be seen from Table 5 that the order of the influence of the presence of the five anions on the degradation effect of SMX by the RM-nZVI / Ni / H2O2 system is HCO3 - > H2PO4 - > SO4 2- > NO3 - > Cl - . The presence of Cl - has almost no influence on the degradation of SMX. The presence of SO4 2- and NO3 - has a slight influence on the degradation efficiency of SMX, but the degradation efficiency can still exceed 60% in 20 minutes. However, the presence of HCO3 - and H2PO4 - ions has an obvious inhibitory effect on the degradation of SMX, and the influence of these two ions on the reaction system needs to be excluded first in practical applications.

[0092] 1.6 Degradation effect of the catalyst described in Example 1 of this application on different antibiotics

[0093] Table 6

[0094]

[0095] As can be seen from Table 6, the removal rates of these four antibiotics all reached 97% after 4 minutes of reaction. In fact, levofloxacin (LFX), norfloxacin, and tetracycline hydrochloride (TC) had been completely degraded and were below the detection limit two minutes after the start of the reaction, indicating the universality of the RM-nZVI / Ni / H2O2 system for different antibiotics.

[0096] The ecological toxicity of SMX and other identified intermediate products was predicted according to the ecological structure-activity relationship model (ECOSAR). Three representative trophic aquatic organisms, namely fish, daphnia, and green algae, were used to evaluate their toxicity levels. According to our speculated pathway, most of the products are non-toxic.

[0097] The cost of preparing the catalyst (RM-nZVI / Ni) material described in this application is also one of the important factors for evaluating its future application prospects. Therefore, we investigated the market prices (per ton) of the raw materials for preparation and calculated the cost of preparing 1 kg of RM-nZVI / Ni material based on this (ignoring factors such as electricity costs).

[0098] Based on the market prices, ferrous sulfate heptahydrate is 0.26 yuan / kg, with a converted unit price of 0.21 yuan / kg; nitrogen is 0.456 yuan / kg, with a converted unit price of 0.01 yuan / kg; red mud is 0 yuan / kg; nickel nitrate hexahydrate is 9 yuan / kg, with a converted unit price of 0.15 yuan / kg; potassium borohydride is 88 yuan / kg, with a converted unit price of 19.23 yuan / kg. After conversion, only 19.60 yuan is required to prepare 1 kg of RM-nZVI / Ni. Querying common antibiotic catalysts on the market, their prices are in the range of 10 - 28 yuan / kg. The cost price of the RM-nZVI / Ni material we prepared is within the acceptable range of market fluctuations. Moreover, this material has a high degradation efficiency, requires less catalyst and oxidant, and has a higher cost performance compared to catalysts on the market. And in actual industrial production, the amount of potassium borohydride with a relatively high converted unit price will be lower than that in the laboratory. Therefore, even considering economic costs, RM-nZVI / Ni has broad application prospects.

[0099] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A red mud-based catalyst, the catalyst comprising zero-valent iron-nickel metal nanosheets and red mud, wherein, The red mud is supported on the zero-valent iron-nickel nanosheets.

2. The catalyst according to claim 1, characterized in that, By weight percentage, the weight percentage of Fe element in the catalyst is 40-60%, the weight percentage of Ni element is 0.5-5%, the weight percentage of Al element is 1-5%, and the weight percentage of Si element is 10-25%.

3. A preparation method of a red mud-based catalyst, comprising the following steps: (1) Mix red mud, an Fe ion-containing compound, and a Ni ion-containing compound in a solvent to obtain a mixed solution; (2) Add a reducing agent to the mixed solution and react to obtain the catalyst.

4. The preparation method according to claim 3, wherein In step (1), the water content of the red mud is ≤5%, and the fineness of the red mud is 10-200 mesh; And / or, the Fe ion-containing compound is selected from FeSO4 or its hydrate, FeCl2 or its hydrate, Fe2(SO4)3 or its hydrate, FeCl3 or its hydrate; And / or, the Ni ion-containing compound is selected from Ni(NO3)2 or its hydrate, NiCl2 or its hydrate, NiSO4 or its hydrate; And / or, the reducing agent is selected from KBH4 or NaBH4; And / or, the solvent is a mixture of ethanol and water. Preferably, the volume ratio of ethanol to water is 1:(1-3); And / or, the mass ratio of the Fe ion-containing compound to the Ni ion-containing compound is: (25-100):1; And / or, the molar ratio of the Fe ion-containing compound to the Ni ion-containing compound is: (50-200):1; And / or, the mass ratio of the red mud to the Fe ion-containing compound is 1:(2-4); And / or, the mass ratio of the red mud to the Ni ion-containing compound is 1:(0.04-0.08); And / or, the molar ratio of the Fe ion-containing compound to the reducing agent is 1:(1.5-3).

5. The preparation method according to claim 3 or 4, characterized in that, In step (2), the reducing agent is added in the form of an aqueous solution; Preferably, the molar concentration of the reducing agent in the aqueous solution is 0.1-0.3 mol / L; Preferably, the addition rate of the aqueous solution is 0.04-0.12 ml per second; And / or, the reaction temperature is 15-30 °C; And / or, the reaction time is 60-80 min.

6. Application of the catalyst according to any one of claims 1-2 or the catalyst obtained by the preparation method according to any one of claims 3-5 in treating antibiotic-containing sewage; Preferably, the antibiotic is sulfamethoxazole, levofloxacin, norfloxacin, ciprofloxacin or tetracycline hydrochloride.

7. A method for treating antibiotic-containing sewage, under acidic conditions, mixing the catalyst according to any one of claims 1-2 or the catalyst obtained by the preparation method according to any one of claims 3-5, hydrogen peroxide and the antibiotic-containing sewage to degrade the antibiotic.

8. According to the treatment method of claim 7, characterized in that When the content of the antibiotic in the antibiotic-containing sewage is 20 ppm, the dosage of the catalyst is 0.05-0.2 g / L, and / or, the dosage of H2O2 is 0.1-5 mM; And / or, the temperature of the reaction is 15 - 30 °C, and the reaction time is 10 - 30 min.

9. The processing method according to claim 7 or 8, characterized in that The pH value of the acidic condition is pH ≤ 5; Preferably, 0.5 - 1.5 mol / L of NaOH and 0.5 - 1.5 mol / L of HCl are used to adjust the pH of the reaction solution.

10. The processing method according to any one of claims 7-9, characterized in that The antibiotic-containing sewage does not contain HCO3 - and H2PO4 - .

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