Rare earth assisted Fe-MnNi supported desulfurization catalyst, preparation method and application

Abstract

The invention provides a rare earth assisted Fe-MnNi supported desulfurization catalyst, and a preparation method and application thereof, and relates to the technical field of environment-friendly materials and catalysis. The method comprises the steps of foam iron pretreatment, metal salt solution preparation, precipitation loading, additive adding, aging drying, roasting and the like. When the catalyst is used for treating the sulfur-containing wastewater, the catalyst is added into the sulfur-containing wastewater, and oxygen-containing gas is introduced through an aeration device. The catalyst provided by the invention has high activity, high stability and strong anti-poisoning ability, can efficiently remove sulfur ions, sulfite radicals and the like, remarkably improves the desulfurization rate, breaks through the limitation of a traditional treatment method, and is widely applicable to sulfur-containing wastewater treatment in the industries of chemical engineering, electroplating, leather and the like.

Description

Technical Field

[0001] The present invention relates to the fields of environmental protection materials and catalytic technologies, and particularly to a rare-earth-assisted Fe-MnNi supported desulfurization catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] In the current process of rapid industrialization, the discharge of sulfur-containing wastewater has become a prominent environmental problem. Industries such as chemical engineering, printing and dyeing, and pharmaceuticals generate a large amount of sulfur-containing wastewater during the production process. Harmful substances such as sulfide ions and sulfite radicals contained therein, if directly discharged into water bodies without effective treatment, will lead to water quality deterioration, cause water eutrophication, and seriously damage the balance of the water ecosystem.

[0003] Traditional sulfur-containing wastewater treatment processes have many drawbacks. Although the chemical precipitation method has a certain ability to precipitate sulfur, it has problems such as a large amount of chemical agents used and a high sludge yield. The subsequent sludge treatment cost is high and it is easy to cause secondary pollution; the biological treatment method is limited by the growth conditions of microorganisms, is sensitive to water quality and water temperature, and the treatment efficiency is unstable, making it difficult to ensure the stable discharge of wastewater up to the standard.

[0004] Supported metal catalysts, as emerging treatment means, have received attention, and many explorations have been carried out on loading transition metal oxides on various carriers. However, many existing supported catalysts show obvious deficiencies when applied to the treatment of sulfur-containing wastewater. For example, the metal active components are unevenly distributed on the carrier, and the binding force with the carrier is weak. In the complex chemical environment of wastewater, the activity is likely to decline or even deactivate. Rare earth elements, due to their unique electron layer structure, have excellent properties in oxygen storage, electron transfer, etc., and have great potential for improving the activity and stability of catalysts. However, in current similar catalysts, rare earth elements are mostly simply doped, and their synergistic effect is not fully exerted, making it difficult to meet the current strict environmental protection requirements.

[0005] Patent CN117046517A uses powdered activated carbon and pyrrole-based adsorbents to prepare a desulfurization catalyst for sulfur-containing wastewater through mechanical stirring and mixing, which has problems such as a small specific surface area of the product and easy loss of active components, and there is a risk of toxicity and skin and respiratory tract irritation during the production process of pyrrole. Patent CN119034745A prepares an in-situ grown FeCoNi catalyst by soaking, drying, and calcining to load iron and cobalt on nickel foam for activating persulfate to degrade microplastics. There are problems such as easy rapid agglomeration and uneven distribution of metal ions during the preparation process, and the binding force of the finished product with the carrier is weak, which is not suitable for the continuous treatment environment of sulfur-containing wastewater. Summary of the Invention

[0006] The object of the present invention is to provide a rare earth-assisted Fe-MnNi supported desulfurization catalyst, a preparation method and an application thereof. This method efficiently incorporates rare earth elements into the Fe-MnNi system to prepare a desulfurization catalyst with high activity, high stability and strong anti-poisoning ability. Applying this catalyst to the treatment of sulfur-containing wastewater is more environmentally friendly.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention first provides a preparation method for a rare earth-assisted Fe-MnNi supported desulfurization catalyst, including:

[0009] Step 1: Pretreatment of foamed iron: Cut the foamed iron into small pieces, first place it in a low-temperature plasma device for surface treatment, and then place it in hydrochloric acid, deionized water, and absolute ethanol in sequence, and perform ultrasonic cleaning and drying in sequence to prepare a foamed iron carrier;

[0010] Step 2: Preparation of metal salt solution: First dissolve Ni(NO3)2 in deionized water and stir, then add Mn(NO3)2, and at the same time dropwise add disodium ethylenediaminetetraacetate and continue stirring to obtain a metal salt solution;

[0011] Step 3: Precipitation loading: Immerse the foamed iron carrier in Step 1 into the metal salt solution in Step 2, stir in a water bath environment, dropwise add a precipitant, and maintain the system pH at 8-9 to promote the loading of metal ions on the foamed iron in the form of carbonate precipitation. Take out the foamed iron loaded with metal, and the metal salt solution after loading is the metal salt mother liquor;

[0012] Step 4: Addition of additives: Select Ce(NO3)3 as the rare earth metal additive. First irradiate the weighed Ce(NO3)3 under ultraviolet light for 10-20 min, with a light intensity of 4-6 mW / cm 2 , and then dissolve it in a cyclohexane-water microemulsion system. After making a microemulsion, evenly spray it on the foamed iron loaded with metal and stir;

[0013] Step 5: Aging: Put the sample with additives obtained in Step 4 back into the metal salt mother liquor in Step 3 and let it stand at 35-45 °C for 2-4 h, then raise the temperature to 55-65 °C and let it stand for 2-4 h, and finally let it stand at 75-85 °C for 2-4 h. After suction filtration, wash it repeatedly with deionized water until there is no NO3 - ;

[0014] Step 6: Drying and calcination: Dry the sample aged in Step 5, and then transfer it to a muffle furnace. First, raise the temperature at a rate of 3 °C / min to 295-305 °C and calcine for 1-2 h, then raise the temperature at a rate of 5 °C / min to 395-405 °C and calcine for 1-2 h, and cool it with the furnace to obtain a rare earth-assisted Fe-MnNi supported desulfurization catalyst.

[0015] Preferably, the treatment conditions of the low-temperature plasma device in Step 1 are to treat for 10 - 20 minutes with a power of 100 - 200 W in an argon atmosphere.

[0016] Preferably, in Mn(NO3)2 in Step 2, Mn accounts for 5 - 6% of the mass of the iron foam carrier, and in Ni(NO3)2, Ni accounts for 3 - 4% of the mass of the iron foam carrier.

[0017] Preferably, the dosage of sodium ethylenediaminetetraacetate (EDTA-2Na) in Step 2 is in a molar ratio of metal ions of 1:0.1.

[0018] Preferably, the stirring in the water bath environment in Step 3 is carried out in a water bath environment at 50 - 55 °C and stirred at 300 r / min for 1 - 2 h.

[0019] Preferably, the addition amount of Ce(NO3)3 in Step 4 is that Ce accounts for 1% of the mass of the iron foam carrier.

[0020] Preferably, the cyclohexane-water microemulsion system in Step 4 is a cyclohexane-water microemulsion system containing 1% Span80 and 2% Tween80, where the volume ratio of cyclohexane to deionized water is 4:6, and after adding 1% Span80 and 2% Tween80, it is made by shaking with a KANGSHI shaker at 300 times / min for 20 min.

[0021] The present invention also provides a rare earth-assisted Fe-MnNi supported desulfurization catalyst obtained by the above preparation method.

[0022] The present invention also provides the application of the above rare earth-assisted Fe-MnNi supported desulfurization catalyst in treating sulfur-containing wastewater.

[0023] Preferably, the application method includes:

[0024] Adding the rare earth-assisted Fe-MnNi supported desulfurization catalyst in the above step to the sulfur-containing wastewater, and uniformly introducing oxygen-containing gas at the bottom of the wastewater through an aeration device.

[0025] Advantages of the present invention

[0026] The present invention provides a rare-earth-assisted Fe-MnNi supported desulfurization catalyst, a preparation method and an application. In this method, the metal support combines low-temperature plasma with special chemical cleaning, innovates the support pretreatment method, activates and purifies the surface, and provides a strong guarantee for subsequent metal loading. The synergistic effect of the stepwise dissolution of metal ions and the complexation with EDTA-2Na can accurately control the metal ion precipitation process and optimize the microstructure of the loaded particles. By innovatively using rare-earth additives, after ultraviolet activation, they are precisely coated and added through microemulsion, promoting the synergistic catalysis of rare earth and transition metals at the atomic level, greatly improving the desulfurization performance and breaking through the limitation of the effect of traditional rare-earth doping. When the prepared rare-earth-assisted Fe-MnNi supported desulfurization catalyst is used for treating sulfur-containing wastewater, it is added to the sulfur-containing wastewater, and oxygen-containing gas is introduced through an aeration device. The catalyst of the present invention has high activity, high stability and strong anti-poisoning ability, can efficiently remove sulfide ions, sulfite ions, etc., and the supporting process is simple, breaking through the limitations of traditional chemical precipitation methods and biological methods, and solving the environmental protection problem of sulfur-containing wastewater.

[0027] The catalyst and treatment method of the present invention are widely applicable to the treatment of sulfur-containing wastewater in industries such as chemical engineering, electroplating, and leather. They can efficiently remove sulfide ions, sulfite ions, etc., reduce the toxicity of wastewater, and help enterprises achieve the discharge of qualified wastewater. Specific embodiments

[0028] The present invention provides a preparation method of a rare-earth-assisted Fe-MnNi supported desulfurization catalyst, including:

[0029] Step 1: Pretreatment of iron foam:

[0030] Precisely cut the iron foam raw material according to the specification of 3 cm × 3 cm, put it into a low-temperature plasma treatment device, preferably in an argon environment, turn on a 100-200 W radio frequency power supply and treat it for 10-20 minutes to optimize the surface microstructure and effectively remove impurities. After taking it out, quickly put it into an 8% hydrochloric acid solution containing 0.5% sodium dodecyl sulfate, preferably clean it under ultrasonic conditions of 40 kHz and 200 W for 15 minutes, and repeat ultrasonic cleaning with deionized water and absolute ethanol in turn to completely remove the residual acid solution and impurities. Finally, dry it in an oven at 50 °C for 2 h to obtain a pure iron foam support;

[0031] Step 2: Preparation of metal salt solution:

[0032] According to the predetermined loading ratio, accurately weigh Mn(NO3)2 with Mn accounting for 5-6% of the mass of the iron foam support and Ni(NO3)2 with Ni accounting for 3-4% of the mass of the iron foam support on an electronic balance. First, place Mn(NO3)2 in deionized water, preferably stir it magnetically at 400 r / min for 15 minutes until completely dissolved, slowly add Ni(NO3)2, and simultaneously dropwise add (according to EDTA4- EDTA-2Na solution with a molar ratio of 1:0.1 to the total metal ions in the solution. After maintaining stirring for 15 min, it is made up to 200 mL with deionized water. Replace the stirring paddle with a polytetrafluoroethylene one and preferably stir continuously at 600 r / min for 30 min to ensure the homogeneity of the solution.

[0033] Step three: Precipitation loading:

[0034] Immerse the pretreated iron foam carrier in the metal salt solution, preferably place it in a constant temperature water bath at 50 - 55 °C, and mechanically stir at 300 r / min for 1 - 2 h to ensure thermal equilibrium and preliminary adsorption. Use a dropper to suck up the precipitant. The precipitant is preferably 0.1 mol / L NH4HCO3 solution and is slowly added dropwise at about 10 drops / min. At the same time, monitor the pH in real time with a pH meter and adjust the system pH to 8 - 9. Keep stirring. The stirring time is preferably 2 h to promote the uniform precipitation of metal ions in the form of carbonates on the surface of the iron foam. Take out the iron foam loaded with metal. The metal salt solution after loading is the metal salt mother liquor.

[0035] Step four: Additive addition:

[0036] Select Ce(NO3)3 as the rare earth metal additive. Accurately weigh Ce(NO3)3 accounting for 1% of the mass of the iron foam carrier and place it in a quartz dish. Irradiate it under an ultraviolet lamp with 4 - 6 mW / cm 2 for 10 - 20 min to excite the electronic state. Dissolve the activated Ce(NO3)3 in the cyclohexane - water microemulsion system. After fully oscillating to form a microemulsion, spray it evenly on the iron foam loaded with metal with a sprayer. Preferably stir at 400 r / min for 30 min to promote adsorption and fusion. The cyclohexane - water microemulsion system is a cyclohexane - water microemulsion system containing 1% Span80 and 2% Tween80, where the volume ratio of cyclohexane to deionized water is 4:6. After adding 1% Span80 and 2% Tween80, use a KANGSHI oscillator to oscillate at 300 times / min for 20 min to make it.

[0037] Step five: Aging:

[0038] Put the sample after loading and adding the additive back into the metal salt mother liquor in step three. First, let it stand at 35 - 45 °C for 2 - 4 h, then raise the temperature to 55 - 65 °C and let it stand for 2 - 4 h, and finally let it stand at 75 - 85 °C for 2 - 4 h. Ensure that the sample is immersed throughout the process to slowly and orderly adjust the internal structure. Filter the sample by suction and rinse it with a large amount of deionized water until no NO3 - is detected in the filtrate.

[0039] Step six: Drying and calcination:

[0040] Lay the aged samples flat on a tray. Preferably, place them in an oven at 100 °C and dry for 12 h to remove free water. Then transfer them to a muffle furnace, heat at a rate of 3 °C / min to 295 - 305 °C and calcine for 1 - 2 h to preliminarily decompose unstable impurities and stabilize the crystal phase. Then heat at a rate of 5 °C / min to 395 - 405 °C and calcine for 1 - 2 h to promote the full growth of the active phase. After completion, cool naturally with the furnace to room temperature to obtain the finished rare earth-assisted Fe-MnNi supported desulfurization catalyst.

[0041] The present invention also provides a rare earth-assisted Fe-MnNi supported desulfurization catalyst obtained by the above preparation method.

[0042] The present invention also provides the application of the above rare earth-assisted Fe-MnNi supported desulfurization catalyst in treating sulfur-containing wastewater.

[0043] Preferably, the application method includes:

[0044] Weigh the rare earth-assisted Fe-MnNi supported desulfurization catalyst prepared above in the range of 0.1 g - 10 g according to the sulfur content of the wastewater and put it into 1 L of sulfur-containing wastewater.

[0045] Assemble an aeration device, including an aeration cylinder, an aeration disc with a diameter of φ3 cm, and a gas flow rate controller. After connecting to a gas source (oxygen or air), place the aeration disc at the bottom of the wastewater, turn on the device and uniformly introduce oxygen-containing gas. Utilize the gas-liquid-solid three-phase interface reaction to catalytically oxidize sulfur compounds in the wastewater and achieve efficient desulfurization and purification.

[0046] The following further describes the present invention in detail with specific examples. The raw materials involved in the examples are all obtained commercially.

[0047] Example 1

[0048] 1. Catalyst preparation

[0049] Step 1: Cut the iron foam into small pieces of 3 cm × 3 cm, put them into a low-temperature plasma device under an argon atmosphere, and treat them at a power of 100 W for 10 minutes. Then successively perform ultrasonic cleaning with 8% hydrochloric acid (containing 0.5% sodium dodecyl sulfate), deionized water, and absolute ethanol. The ultrasonic frequency is 40 kHz and the power is 200 W, and clean for 15 min respectively. Finally, dry in an oven at 50 °C for 2 h to obtain a pure iron foam carrier;

[0050] Step 2: First dissolve Mn(NO3)2 in 50 mL of deionized water, stir at 400 r / min for 15 min, then slowly add Ni(NO3)2, and simultaneously dropwise add (by EDTA 4-Ethylenediaminetetraacetic acid disodium (EDTA-2Na) with a molar ratio of 1:0.1 to the total metal ions in the solution was used as a complexing agent. After continuous stirring for 15 min, it was dissolved in deionized water and made up to 200 mL, and magnetically stirred at a speed of 600 r / min for 30 min to obtain a metal salt solution; the effective metal components in Mn(NO3)2 and Ni(NO3)2 accounted for 6% and 4% of the mass of the iron foam carrier, respectively;

[0051] Step 3: Immerse the iron foam carrier in the metal salt solution, and under a water bath environment of 50 °C, stir at 300 r / min for 1 h. Add 0.1 mol / L NH4HCO3 solution dropwise to the metal salt solution at a dropping rate of about 10 drops / min, and maintain the pH of the system at 8.5 during this period to uniformly precipitate metal carbonate on the carrier. Take out the iron foam loaded with metal salt for standby. The metal salt solution after loading is the metal salt mother liquor.

[0052] Step 4: Activate Ce(NO3)3 (the addition amount of Ce accounts for 1% of the mass of the iron foam carrier) by irradiating with ultraviolet light with an intensity of 5 mW / cm 2 for 15 min, and disperse it in a cyclohexane-water microemulsion system containing 1% Span80 and 2% Tween80 (where the volume ratio of cyclohexane to deionized water is 4:6, and after adding 1% Span80 and 2% Tween80, it is shaken with a Kangshi shaker at 300 times / min for 20 min to make it). After making the microemulsion, it is evenly sprayed on the iron foam loaded with metal, and stirred at 400 r / min for 30 min;

[0053] Step 5: The sample after loading and adding additives is first left standing in the mother liquor at 40 °C for 4 h, then heated to 60 °C and left standing for 4 h, and finally left standing at 80 °C for 4 h for aging treatment. After suction filtration, it is repeatedly washed with deionized water until there is no NO3 - , then dried in an oven at 100 °C for 12 h, and finally calcined in a muffle furnace at a heating rate of 3 °C / min to 300 °C for 2 h, and then heated to 400 °C at a heating rate of 5 °C / min for 2 h, and cooled with the furnace to obtain the desulfurization catalyst.

[0054] 2. Wastewater treatment

[0055] Take 1 L of sulfur-containing wastewater from the chemical industry (the detected sulfur ion concentration is 18,200 mg / L, and the sulfite ion concentration is 5,700 mg / L), add 5 g of the prepared catalyst above, and pass air into the bottom of the wastewater through an aeration cylinder equipped with an aeration disk with a diameter of φ3 cm and a gas flow controller at a flow rate of 0.5 L / min, and react at room temperature (25 °C) for 2 h. After the reaction, the sulfur ion concentration in the wastewater is detected by ion chromatography to be 240 mg / L, and the sulfite ion concentration is 110 mg / L. According to the formula: desulfurization rate = [(initial sulfur ion concentration + initial sulfite ion concentration) - (sulfur ion concentration after reaction + sulfite ion concentration after reaction)] / (initial sulfur ion concentration + initial sulfite ion concentration) × 100%, the calculated desulfurization rate is 98.34%.

[0056] Example 2

[0057] 1. Catalyst preparation

[0058] Change the addition amounts of Mn(NO3)2 and Ni(NO3)2 in Step 2 so that their effective metal components account for 5% and 3% of the mass of the iron foam carrier respectively, and the other steps are the same as in Example 1 to prepare the catalyst.

[0059] 2. Wastewater treatment

[0060] Take 1 L of sulfur-containing wastewater from the electroplating industry (the detected sulfur ion concentration is 10,450 mg / L, and the sulfite ion concentration is 8,380 mg / L), add 3 g of this catalyst, and pass oxygen into the bottom of the wastewater through an aeration cylinder equipped with an aeration disk with a diameter of φ3 cm and a gas flow controller at a flow rate of 0.8 L / min, and react at 30 °C for 3 h. After the reaction, the sulfur ion concentration in the wastewater is detected to be 270 mg / L, and the sulfite ion concentration is 140 mg / L. According to the above desulfurization rate calculation formula, the desulfurization rate is 97.82%.

[0061] Comparative Example 1

[0062] 1. Catalyst preparation

[0063] Do not perform the low-temperature plasma treatment in Step 1. The specific steps of Step 1 are as follows:

[0064] Step 1 is specifically: Cut the iron foam into small pieces of 3 cm × 3 cm, and directly ultrasonically clean it with 8% hydrochloric acid (containing 0.5% sodium dodecyl sulfate), deionized water and absolute ethanol. The ultrasonic frequency is 40 kHz, the power is 200 W, and clean for 15 min respectively. Finally, dry it in an oven at 50 °C for 2 h to obtain a pure iron foam carrier; prepare the catalyst in the same way as in Example 1 for the other steps.

[0065] 2. Wastewater treatment

[0066] The same sulfur-containing wastewater from the chemical industry as in Example 1 (with a sulfur ion concentration of 18,200 mg / L and a sulfite ion concentration of 5,700 mg / L) was treated with this catalyst. The amount of catalyst added was 5 g. Air was introduced at a flow rate of 0.5 L / min at the bottom of the wastewater through an aeration cylinder equipped with an aeration disk with a diameter of φ3 cm and a gas flow rate controller, and the reaction was carried out at room temperature (25 °C) for 2 h. After the reaction, the sulfur ion concentration in the wastewater was detected to be 4,340 mg / L, and the sulfite ion concentration was 420 mg / L. According to the desulfurization rate calculation formula, the desulfurization rate was obtained as 80.08%, which was significantly lower than the desulfurization rate of 98.34% in Example 1, indicating that the low-temperature plasma treatment has an important impact on the performance of the catalyst.

[0067] Comparative Example 2

[0068] 1. Catalyst preparation

[0069] The catalyst was prepared without adding the rare earth promoter Ce(NO3)3, and the other steps were the same as in Example 1.

[0070] 2. Wastewater treatment

[0071] The same sulfur-containing wastewater from the chemical industry as in Example 1 (with a sulfur ion concentration of 18,200 mg / L and a sulfite ion concentration of 5,700 mg / L) was treated with this catalyst. The added amount was 5 g. Air was introduced at a flow rate of 0.5 L / min at the bottom of the wastewater through an aeration cylinder equipped with an aeration disk with a diameter of φ3 cm and a gas flow rate controller, and the reaction was carried out at room temperature (25 °C) for 2 h. After the reaction, the sulfur ion concentration in the wastewater was detected to be 8,220 mg / L, and the sulfite ion concentration was 610 mg / L. According to the desulfurization rate calculation formula, the desulfurization rate was obtained as 63.05%, which was even more significantly lower than the desulfurization rate of 98.34% in Example 1, indicating that the rare earth promoter has a significant promoting effect on the desulfurization performance.

[0072] Through the above examples and comparative examples, the advantages of the rare earth-assisted Fe-MnNi supported desulfurization catalyst of the present invention in the treatment of sulfur-containing wastewater, as well as the effects of each key step and promoter on the performance of the catalyst, can be clearly seen.

Claims

1. A preparation method of a rare earth-assisted Fe-MnNi supported desulfurization catalyst, characterized in that, Including: Step 1: Pretreatment of iron foam: Cut the iron foam into small pieces, first place it in a low-temperature plasma device for surface treatment, and then place it in hydrochloric acid, deionized water, and absolute ethanol in sequence, and perform ultrasonic cleaning and drying in sequence to prepare an iron foam carrier; Step 2: Preparation of metal salt solution: First dissolve Ni(NO3)2 in deionized water and stir, then add Mn(NO3)2, and at the same time dropwise add disodium ethylenediaminetetraacetate and continue to stir to obtain a metal salt solution; Step 3: Precipitation loading: Immerse the iron foam carrier in Step 1 into the metal salt solution in Step 2, stir in a water bath environment, dropwise add a precipitant, and maintain the pH of the system at 8-9 to promote the loading of metal ions on the iron foam in the form of carbonate precipitation, take out to obtain the iron foam loaded with metal, and the metal salt solution after loading is the metal salt mother liquor; Step 4: Additive addition: Select Ce(NO3)3 as the rare earth metal additive. First, irradiate the weighed Ce(NO3)3 under ultraviolet light for 10 - 20 min with a light intensity of 4 - 6 mW / cm 2 , and then dissolve it in the cyclohexane - water microemulsion system. After making the microemulsion, evenly spray it on the iron foam loaded with metal and stir; Step Five: Aging: Put the sample with additives obtained in Step Four back into the metal salt mother liquor in Step Three, let it stand still at 35 - 45°C for 2 - 4 h, then raise the temperature to 55 - 65°C and let it stand still for 2 - 4 h, and finally let it stand still at 75 - 85°C for 2 - 4 h. After suction filtration, wash it repeatedly with deionized water until there is no NO3 - ; Step 6: Drying and calcination: Dry the sample aged in Step 5, and then transfer it to a muffle furnace. First, heat it at a rate of 3 °C / min to 295-305 °C and calcine for 1-2 h, then heat it at a rate of 5 °C / min to 395-405 °C and calcine for 1-2 h, and cool it with the furnace to obtain a rare-earth-assisted Fe-MnNi supported desulfurization catalyst.

2. The preparation method of a rare earth-assisted Fe-MnNi supported desulfurization catalyst according to claim 1, characterized in that, The treatment conditions of the low-temperature plasma device described in Step 1 are to treat it at a power of 100-200 W for 10-20 minutes in an argon atmosphere.

3. The preparation method of a rare earth-assisted Fe-MnNi supported desulfurization catalyst according to claim 1, characterized in that, In Mn(NO3)2 described in Step 2, Mn accounts for 5-6% of the mass of the iron foam carrier, and in Ni(NO3)2, Ni accounts for 3-4% of the mass of the iron foam carrier.

4. The preparation method of a rare earth-assisted Fe-MnNi supported desulfurization catalyst according to claim 1, characterized in that, The dropwise addition amount of disodium ethylenediaminetetraacetate (EDTA-2Na) described in Step 2 is in a molar ratio of metal ions of 1:0.

1.

5. The preparation method of a rare earth-assisted Fe-MnNi supported desulfurization catalyst according to claim 1, characterized in that, The stirring in the water bath environment described in Step 3 is in a water bath environment of 50-55 °C and stir at 300 r / min for 1-2 h.

6. The preparation method of a rare earth-assisted Fe-MnNi supported desulfurization catalyst according to claim 1, characterized in that, The addition amount of Ce(NO3)3 described in Step 4 is that Ce accounts for 1% of the mass of the iron foam carrier.

7. The preparation method of a rare earth-assisted Fe-MnNi supported desulfurization catalyst according to claim 1, characterized in that, The cyclohexane-water microemulsion system described in Step 4 is a cyclohexane-water microemulsion system containing 1% Span80 and 2% Tween80, where the volume ratio of cyclohexane to deionized water is 4:6, and after adding 1% Span80 and 2% Tween80, it is shaken with a KANGSHI shaker at 300 times / min for 20 min to make it.

8. The rare-earth-assisted Fe-MnNi supported desulfurization catalyst obtained by the preparation method described in Claim 1.

9. The application of the rare-earth-assisted Fe-MnNi supported desulfurization catalyst described in Claim 8 in treating sulfur-containing wastewater.

10. The application method according to claim 9, wherein, Including: Add the rare-earth-assisted Fe-MnNi supported desulfurization catalyst in the above steps to the sulfur-containing wastewater, and uniformly introduce oxygen-containing gas at the bottom of the wastewater through an aeration device.