CN115634714B - Preparation method and application of self-driven Mn/Fe composite plant fiber tubular micromotor catalyst - Google Patents
Preparation method and application of self-driven Mn/Fe composite plant fiber tubular micromotor catalyst Download PDFInfo
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Abstract
The invention discloses a preparation method and application of a self-driven Mn/Fe composite plant fiber tubular micromotor catalyst, and belongs to the field of inorganic micro-nano materials and environments. The Mn/Fe composite catalysis tubular micro-nano motor is prepared by using natural plant fibers with a hollow tubular structure as a template and growing Mn/Fe composite catalysis materials on the surfaces of the natural plant fibers in situ through an impregnation method, a hydrothermal method and a codeposition method, and the Mn/Fe composite catalysis tubular micro-nano motor is used as a catalyst of hydrogen peroxide/persulfate to repair organic polluted water and soil in situ so as to realize autonomous movement. Meanwhile, the loaded magnetic MnFe 2O4 or Fe 3O4 nano particles can synergistically activate hydrogen peroxide and persulfate with MnO 2 to generate Fenton-like reaction. On one hand, the problems of secondary pollution and difficult recycling caused by directly adding iron ions and manganese ions are avoided, on the other hand, the contact mass transfer process of the catalyst and pollutants and the self-diffusion effect of the catalyst in a water-soil restoration area are enhanced, and the catalyst diffusion and pollutant degradation efficiency are remarkably improved.
Description
Technical Field
The invention belongs to the field of inorganic micro-nano materials and environments, and particularly relates to a preparation method and application of a self-driven Mn/Fe composite plant fiber tubular micromotor catalyst.
Background
With the development of social economy, the problem of global ecological system pollution is increasingly prominent, and especially, water pollution and soil pollution caused by human activities and intensive agriculture are serious threats to human health while destroying water resources and soil resources. Organic pollutants have become a focus of attention worldwide due to the characteristics of persistent presence in the environment, difficulty in biodegradation, bioaccumulation through food chains, and the like.
In the practical application of in-situ soil and water remediation, the heterogeneous catalyst is easy to agglomerate, so that the migration and the diffusivity of the heterogeneous catalyst in water and soil are low, and the persulfate activation effect and the oxidative degradation efficiency are seriously affected. How to improve the migration effect of a repairing agent in the environment has been one of the key problems in-situ water and soil repairing. Particularly in the in-situ remediation of soil, the oxidizing agent is usually injected into the soil in the form of a solution through stirring, high-pressure rotary spraying, well construction injection, direct pushing injection and other processes. The stirring process requires crushing of the ground and has a limited treatment depth due to the limitations of the working equipment. Under the condition of no external mechanical stirring, the strength of the diffusion effect of the oxidizing agent in the soil directly influences the repairing effect. Soil with low permeability and subsurface non-uniformities can have a significant impact on migration of injected oxidants. In recent years, as a micro-nano functional material with unique self-driving characteristics, the rapid development of a micro-nano motor provides a new approach for water pollution and soil pollution control. Compared with the traditional environment repairing micro-nano material, the micro-nano motor can obtain driving force from the external environment, and can extend into narrow spaces such as soil gaps to perform long-distance large-range operation, and meanwhile, the autonomous movement and the accompanying micro-nano bubbles can be utilized to enhance the migration and diffusion of the repairing agent in water and soil, so that the repairing efficiency is improved. In addition, the device does not affect the self-driving while carrying a large amount of repairing material, and the orientation of the device can be precisely controlled through an external field, so that targeted distribution and efficient recovery are realized. In-situ soil and water remediation, the characteristics of the micro-nano motor provide a new strategy for enhancing the migration of the remediation agent and improving the degradation efficiency of pollutants.
Patent application CN111825241A, a method and a device for treating pollutants based on micro-nano motor materials, provides a method for treating micro-plastic pollutants based on micro-nano motor materials, which comprises the following steps: adding a micro-nano motor material into sewage to be treated, then adding hydrogen peroxide into the sewage to start a treatment process, carrying out catalytic reaction on the micro-nano motor material in the water to be treated, continuously generating micro-nano bubbles, driving pollutants in the water to float to the water surface and be enriched in a bubble foam phase, and separating the foam phase from the sewage. The micro-nano motor material is a material capable of catalyzing hydrogen peroxide to decompose. The pertinence to soil and water restoration is not high, and the source of the micro motor is completely dependent on chemical synthesis.
Disclosure of Invention
The first object of the invention is to provide a preparation method of a self-driven Mn/Fe composite catalysis tubular micromotor based on plant fibers, which is simple and convenient to operate, economical, reliable, environment-friendly and has unique self-driven and self-diffusion characteristics. In an environment containing low-concentration hydrogen peroxide, the self-driven material can move autonomously with high efficiency. The preparation method is suitable for various plant fibers with hollow tubular structures, and has universality.
The second object of the invention is to provide the application of the self-driven Mn/Fe composite catalytic tubular micromotor catalyst based on plant fibers prepared by the method in enhancing migration and diffusion of a repairing agent in-situ soil and water repair, and the self-driven micromotor repairing material prepared by adding the self-driven micromotor repairing material into an environment repairing agent can effectively enhance the transverse and longitudinal migration and diffusion of the repairing agent in soil and water, so that the treatment range is enlarged.
The third object of the invention is to provide the application of the self-driven Mn/Fe composite catalysis tubular micromotor catalyst based on plant fibers prepared by the method in advanced oxidation degradation of organic pollutants in water and soil, which is environment-friendly, and can enhance mass transfer effect in an advanced oxidation system containing hydrogen peroxide through self-driving and generated micro-nano bubbles, thereby improving the degradation efficiency of the organic pollutants. The method is applicable to various pollutants which can be degraded by an advanced oxidation method, and has universality.
In order to achieve the above purpose, the present invention mainly provides the following technical solutions:
A preparation method of a self-driven Mn/Fe composite plant fiber tubular micromotor catalyst comprises the following steps:
(1) Processing natural plant fiber with hollow tubular structure into proper length;
(2) Modifying MnFe 2O4@MnO2 on the plant fiber with a tubular structure by an impregnation method and a codeposition method; or modifying Fe 3O4@MnO2 on the plant fiber with the tubular structure by a hydrothermal method;
Further, the preparation and use method of the self-driven Mn/Fe composite plant fiber tubular micromotor catalyst for in-situ remediation of polluted water and soil comprises the following specific steps:
(1) Cutting natural plant fiber (kapok fiber, karaya fiber, etc.) with hollow tubular structure to control its length within the range of pipe diameter to 1mm to obtain tubular plant fiber template;
(2) Modifying MnFe 2O4@MnO2 on plant fiber with a tubular structure: dispersing a tubular plant fiber template in a potassium permanganate solution, magnetically stirring, soaking for 3-72 hours at room temperature, filtering and collecting a product, washing with a large amount of deionized water and ethanol, placing the product in a freeze dryer, maintaining for a period of time until the product is dried to obtain a MnO 2 tubular micromotor, dispersing the MnO 2 tubular micromotor in an aqueous solution of MnFe 2O4 nano particles, wherein the mass ratio of the MnO 2 tubular micromotor to the MnFe 2O4 nano particles is 5:1, oscillating for more than 1 day at room temperature, centrifugally collecting the product, washing with a large amount of deionized water and ethanol, placing the product in the freeze dryer, and maintaining for a period of time until the product is dried to obtain the MnFe 2O4@MnO2 tubular micromotor;
Or modifying Fe 3O4@MnO2 on the plant fiber with a tubular structure by a hydrothermal method: dispersing a tubular plant fiber template in an ethylene glycol solution containing ferric chloride, sodium citrate and sodium acetate, uniformly mixing, placing the mixture in a hydrothermal kettle, keeping the mixture at the temperature of 200 ℃ for 12 hours, naturally cooling, filtering and collecting a product, washing the product with a large amount of deionized water and ethanol, placing the product in a freeze dryer, keeping the product for a period of time until the product is dried to obtain Fe 3O4 tubular fibers, dispersing 0.075g of Fe 3O4 tubular fibers in a potassium permanganate solution containing hydrochloric acid, oscillating for 30 minutes, placing the obtained mixed solution in the hydrothermal kettle, keeping the mixture at the temperature of 100 ℃ for 6 hours, naturally cooling, filtering and collecting the product, washing the product with a large amount of deionized water and ethanol, placing the product in the freeze dryer, and keeping the product for a period of time until the product is dried to obtain the Fe 3O4@MnO2 tubular micromotor.
The self-driven Mn/Fe composite catalysis tubular micro motor prepared by the invention can enhance the longitudinal and transverse migration and diffusion effects of the repairing agent in soil. The method comprises the following steps: when in-situ restoring water and soil, hydrogen peroxide and the prepared self-driven tubular micro-motor are added into the restoration agent, and the micro-motor can enhance the migration and diffusion of the restoration agent through the self-driven without a cable and the generated micro-nano bubbles, so that the application range is enlarged.
The invention also provides application of the self-driven Mn/Fe composite catalytic tubular micromotor prepared by the method in oxidizing and degrading organic pollutants such as tetracycline, norfloxacin and fluoranthene in water and soil through Fenton-like reaction. The method comprises the following steps: the prepared self-driven Mn/Fe composite catalysis tubular micromotor is used as a catalyst of a hydrogen peroxide/persulfate compound system, and organic pollutants in water and soil are degraded by free radicals with strong oxidability generated by activating hydrogen peroxide and persulfate.
The specific steps for degrading the tetracycline in the soil are as follows: contaminated soil was formulated to contain tetracycline at a concentration of 400mg kg -1. 5g of tetracycline-contaminated soil was added with 50mL of a 1% hydrogen peroxide solution to prepare a suspension, persulfate (5 mM) was added, and then 50mg of the above-prepared self-driven Mn/Fe composite catalytic tubular micro motor was added to react at room temperature for 30 minutes. Under the same reaction condition, the catalytic system containing persulfate, hydrogen peroxide and self-driven Mn/Fe composite catalytic tubular micromotor has highest tetracycline degradation efficiency. The self-driven tubular fiber micro motor can be magnetically controlled and recycled.
The specific steps for degrading norfloxacin in soil are as follows: the contaminated soil containing norfloxacin at a concentration of 40mg kg -1 was formulated. 5g of norfloxacin-contaminated soil was added to 10mL of a 1% hydrogen peroxide solution to prepare a suspension, persulfate (1 mM) was added, and then 50mg of the above-prepared Mn/Fe composite catalytic tubular micromotor was added to react at room temperature for 15 minutes. Under the same reaction condition, the degradation efficiency of the catalytic system containing persulfate, hydrogen peroxide and the self-driven Mn/Fe composite catalytic tubular micromotor on norfloxacin is highest. The self-driven tubular fiber micro motor can be magnetically controlled and recycled.
The specific steps for degrading fluoranthene in soil are as follows: contaminated soil containing fluoranthene at a concentration of 40mg kg -1 was formulated. 5g of fluoranthene-polluted soil is added into 10mL of hydrogen peroxide solution with the concentration of 1% to prepare suspension, persulfate (1 mM) is added, 50mg of the prepared Mn/Fe composite catalytic tubular micromotor is added, and the reaction is carried out for 180 minutes at room temperature. Under the same reaction condition, the degradation efficiency of the catalytic system containing persulfate, hydrogen peroxide and the self-driven Mn/Fe composite catalytic tubular micromotor on fluoranthene is highest. The self-driven tubular fiber micro motor can be magnetically controlled and recycled.
The natural tubular plant fiber template adopted by the method can be used, but is not limited to, phoenix tree fiber and kapok fiber, and any plant fiber with a hollow tubular structure can be used for preparing the tubular micromotor catalyst by the method. The persulfate used in the advanced oxidation compounding system for degrading organic pollutants is not limited to the peroxomonosulfate PMS, but peroxodisulfate PDS and the like can be used. The oxidative degradation pollutants are not limited to antibiotics such as tetracycline, norfloxacin and fluoranthene and polycyclic aromatic hydrocarbon, and any organic pollutant which is easy/indissolvable in water and can be oxidatively degraded through Fenton reaction and Fenton-like reaction can be efficiently degraded by the method.
Compared with the prior art, the invention has the following advantages:
1. The catalyst for Fenton-like reaction prepared by the invention is a tubular micromotor based on a plant fiber template, and the adopted plant fiber has the advantages of natural environment friendliness, rich yield, low price, uniform structure and the like, and is suitable for batch preparation of environmental functional materials. The tubular micromotor capable of moving autonomously can be obtained by in-situ modification of the required catalyst on the natural plant fiber with the hollow tubular structure through a simple hydrothermal method, an impregnation method and a codeposition method, so that expensive instrument materials and complex operation steps used in the preparation of the traditional tubular micromotor are avoided, and the requirements of environmental protection are met;
2. The catalyst for Fenton-like reaction prepared by the invention is a self-driven catalyst, can realize self-driving in water and soil, can utilize a special tubular structure of plant fibers, and can obtain driving force by catalyzing hydrogen peroxide to decompose and jet micro-nano bubbles from microtubules so as to realize autonomous movement, thereby performing tasks in narrow space which cannot be reached by the traditional means, and also performing long-distance, large-range and in-situ operation;
5. The catalyst for Fenton-like reaction prepared by the invention is a heterogeneous catalyst with self-driving capability, can realize separation, recovery, treatment and repeated use through simple magnetic control after the reaction is finished, does not cause secondary pollution, meets the requirements of green and environment protection, and overcomes the problems of catalyst agglomeration and the defects of the traditional Fenton reagent;
6. the catalyst for Fenton-like reaction prepared by the invention can enhance the transverse and longitudinal migration efficiency of the repairing agent in polluted water and soil, expand the range of the repairing agent in a polluted area and improve the utilization efficiency of the catalyst through the autonomous movement and the action of the generated micro-nano bubbles;
7. The self-driven Fenton-like reaction catalyst prepared by the invention can effectively improve the reaction efficiency of degrading organic pollutants and the treatment effect of the organic pollutants in water and soil through the autonomous movement and the enhanced mass transfer effect of the generated micro-nano bubbles.
Drawings
Fig. 1 is a general optical microscope image of a tubular micro motor with different lengths prepared in example 1 of the present invention, wherein a is a tubular micro motor (M S) with a length smaller than the pipe diameter, B is a tubular micro motor (M M) with a length between the pipe diameter and 1mm, and C is a tubular micro motor (M L) with a length greater than 1mm.
FIG. 2 is a schematic illustration of the preparation of self-driven MnFe 2O4@MnO2 tubular micro-motor and self-driven Fe 3O4@MnO2 tubular micro-motor prepared in example 2 of the present invention.
FIG. 3 is a Scanning Electron Microscope (SEM) image of a MnO 2 tubular micromotor and a MnFe 2O4@MnO2 tubular micromotor prepared in example 2 of the present invention, where A is a MnO 2 tubular micromotor and B is a MnFe 2O4@MnO2 tubular micromotor.
FIG. 4 is an X-ray Energy Dispersive (EDX) image of a MnFe 2O4@MnO2 tubular micro-motor prepared in example 2 of the present invention.
Fig. 5 is a Scanning Electron Microscope (SEM) image of the Fe 3O4 tubular fiber and the Fe 3O4@MnO2 tubular micromotor prepared in example 2 of the present invention, where a is the Fe 3O4 tubular fiber and B is the Fe 3O4@MnO2 tubular micromotor.
FIG. 6 is an X-ray Energy Dispersive (EDX) image of a Fe 3O4@MnO2 tubular micro-motor prepared in example 2 of the present invention.
FIG. 7 is a schematic view of an apparatus for soil packing column migration test of Mn/Fe composite catalytic tubular micro motor according to example 3 of the present invention.
Fig. 8 shows a soil packing column migration experiment of a static Fe 3O4@MnO2 tubular micro-motor and a self-driven Fe 3O4@MnO2 tubular micro-motor according to example 3 of the present invention, where a is the longitudinal migration effect of the static Fe 3O4@MnO2 tubular micro-motor in the soil column and B is the longitudinal migration effect of the self-driven Fe 3O4@MnO2 tubular micro-motor in the soil column.
Fig. 9 shows a soil-packed column migration experiment of a static Fe 3O4@MnO2 tubular micro-motor and a self-driven Fe 3O4@MnO2 tubular micro-motor according to example 3 of the present invention, where a is the local migration effect (water injection end and water outlet end) of the static Fe 3O4@MnO2 tubular micro-motor in the soil column, and B is the local migration effect (water injection end and water outlet end) of the self-driven Fe 3O4@MnO2 tubular micro-motor in the soil column.
FIG. 10 is a soil packing column migration recovery experiment of the different hydrogen peroxide concentration systems of example 4 of the present invention on a self-driven Mn/Fe composite catalytic tubular micro motor.
FIG. 11 is a graph showing the soil packing column migration recovery ratio of the different hydrogen peroxide concentration systems of example 4 of the present invention to a self-driven Mn/Fe composite catalytic tubular micro-motor.
FIG. 12 is a schematic diagram showing the preparation of a CN-Fe 3O4@MnO2 tubular micro motor prepared in example 5 of the present invention.
FIG. 13 is a schematic diagram showing an apparatus for a lateral migration experiment of a CN-Fe 3O4@MnO2 tubular micro motor in a soil layer, which was set in example 5 of the present invention.
FIG. 14 shows the lateral migration experiments of the static CN-Fe 3O4@MnO2 tubular micro-motor and the self-driven CN-Fe 3O4@MnO2 tubular micro-motor of the invention in the soil layer, wherein A is the lateral migration effect of the static CN-Fe 3O4@MnO2 tubular micro-motor in the soil layer, and B is the lateral migration effect of the self-driven CN-Fe 3O4@MnO2 tubular micro-motor in the soil layer;
FIG. 15 is a schematic view of an apparatus for calculating mobility of a CN-Fe 3O4@MnO2 tubular motor as set in example 6 in a soil packing column.
FIG. 16 is an experiment for calculating mobility of the static CN-Fe 3O4@MnO2 tubular micro-motor and the self-driven CN-Fe 3O4@MnO2 tubular micro-motor of example 6 in a soil-filled column, wherein A is a fluorescence ratio of the static CN-Fe 3O4@MnO2 tubular micro-motor at different times and sampling points in the soil-filled column, and B is a fluorescence ratio of the self-driven CN-Fe 3O4@MnO2 tubular micro-motor at different times and sampling points in the soil-filled column.
FIG. 17 is a graph showing the degradation efficiency of the different catalytic reaction systems of example 7 on tetracycline contaminated soil.
FIG. 18 shows the degradation efficiency of the different catalytic reaction systems of example 8 on norfloxacin contaminated soil.
Fig. 19 is the degradation efficiency of the different catalytic reaction systems of example 9 on fluoranthene-contaminated soil.
Detailed Description
The invention will be described in further detail with reference to the drawings and the specific examples.
Example 1
To investigate the effect of the length of the fiber template after mechanical cutting on the tubular micromotor preparation. The untreated tubular plant fiber is cut into a fiber template with the length smaller than the pipe diameter, the length between the pipe diameter and 1 millimeter and the length larger than 1 millimeter, the obtained fiber templates are respectively dispersed in 1M potassium permanganate solution (60 mL), after magnetic stirring for 1 hour, the fiber templates are soaked for 72 hours at room temperature, then the product is filtered and collected and is washed by a large amount of deionized water and ethanol, the product is placed in a freeze dryer at minus 60 ℃ for 12 hours, and the tubular micromotors are obtained and respectively marked as M S、MM、ML. The resulting tubular micro-motor was dispersed in a solution containing 1.0% hydrogen peroxide and 0.1% SDS to observe its movement, and the movement behavior of the micro-motor was photographed using an optical microscope equipped with OLYMPUS cellSens Dimension system.
As shown in fig. 1, a general optical microscope image of the tubular micro motor prepared in example 1. As can be seen from fig. 1A: when the tubular plant fiber is cut to a length smaller than the pipe diameter, the image shows that the tubular structure of the tubular micromotor M S obtained is broken and stationary, which proves that: when the tubular plant fiber is cut to a length smaller than the pipe diameter, the tubular structure required for the micro motor movement will not be maintained and no bubbles and driving force will be generated in the fuel solution. As can be seen from fig. 1B: when the tubular plant fiber is cut to length between pipe diameter and 1 mm, the image shows that the tubular micro-motor M M is complete in tubular structure and exhibits excellent movement behavior, which proves that: when the tubular plant fiber is cut to a length of 1 mm in the pipe diameter, the tubular structure required for the micro motor movement can be maintained and bubbles and driving force can be generated in the fuel solution. As can be seen from fig. 1C: when the tubular plant fiber is cut to a length of more than 1 mm, the image shows that the tubular structure of the resulting tubular micromotor M L is complete but stationary, which proves that: when the tubular plant fiber is cut to a length of more than 1 mm, the tubular structure required for the micro-motor movement can be maintained, but the tubular micro-motor M L generates only bubbles in the fuel solution but does not generate movement behavior due to the large mass of the fiber motor.
Example 2
The self-driven Mn/Fe composite plant fiber tubular micro motor is prepared under the optimal experimental conditions.
As shown in fig. 2, mnFe 2O4@MnO2 tubular micro-motor and Fe 3O4@MnO2 tubular micro-motor were obtained by loading MnFe 2O4@MnO2 or Fe 3O4@MnO2 on a natural plant fiber template having a hollow tubular structure. The method comprises the following specific steps:
(1) Cutting kapok fiber and phoenix tree fiber by using a machining method to control the lengths of the kapok fiber and the phoenix tree fiber within the range of pipe diameters to 1mm, thereby obtaining a kapok fiber template and a phoenix tree fiber template.
(2) MnFe 2O4@MnO2 is loaded on a kapok fiber template, and the method comprises the following specific steps: feCl 3·6H2O(2g)、MnCl2·4H2 O (0.752 g), naAc (5 g) and PEG (3 g) were dispersed in 70mL EG, sonicated and magnetically stirred for 1 hour or more, and after complete dissolution, the mixed solution was transferred to a hydrothermal kettle and maintained at 200℃for 10 hours. Cooling to room temperature after the reaction is finished, centrifugally collecting a product, washing the product by using a large amount of deionized water and ethanol, and placing the product in a freeze dryer at the temperature of minus 60 ℃ for 12 hours to obtain the MnFe 2O4 nano-particles. Dispersing 1.2g of kapok fiber template in 1M potassium permanganate solution (60 mL), magnetically stirring for 1 hour, soaking for 3-72 hours at room temperature, filtering and collecting the product, washing with a large amount of deionized water and ethanol, placing the product in a freeze dryer at minus 60 ℃, and keeping for 12 hours to obtain the MnO 2 tubular micromotor. And dispersing the MnO 2 tubular micromotor in an aqueous solution of MnFe 2O4 nano particles, wherein the mass ratio of the MnO 2 tubular micromotor to the MnFe 2O4 nano particles is 5:1, oscillating for more than 1 day at room temperature, centrifugally collecting a product, washing the product with a large amount of deionized water and ethanol, and placing the product in a freeze dryer at minus 60 ℃ for 12 hours to obtain the MnFe 2O4@MnO2 tubular micromotor.
Or loading Fe 3O4@MnO2 on a phoenix tree fiber template, and specifically comprises the following steps: dispersing 0.2g of phoenix tree fiber template in an ethylene glycol solution (68 mL) containing ferric chloride (2.2 g), sodium citrate (0.8 g) and sodium acetate (6.64 g), uniformly mixing, placing in a hydrothermal kettle, maintaining at 200 ℃ for 12 hours, naturally cooling, filtering, collecting a product, washing with a large amount of deionized water and ethanol, placing the product in a freeze dryer at minus 60 ℃ for 12 hours, and obtaining Fe 3O4 tubular fibers. Dispersing 0.075g Fe 3O4 tubular fiber in 0.055M potassium permanganate solution (20 mL), adding 0.25mL concentrated hydrochloric acid, oscillating for 30min, placing the obtained mixed solution in a hydrothermal kettle, maintaining at 100deg.C for 6 hr, naturally cooling, filtering, collecting product, washing with a large amount of deionized water and ethanol, placing the product in a freeze dryer at-60deg.C for 12 hr, and obtaining Fe 3O4@MnO2 tubular micromotor.
Scanning Electron Microscope (SEM) tests were performed on the MnO 2 tubular micromotor and the MnFe 2O4@MnO2 tubular micromotor prepared in example 2.
As shown in FIG. 3, SEM images of MnO 2 tubular micromotors and MnFe 2O4@MnO2 tubular micromotors prepared in example 2. As can be seen from fig. 3A: the MnO 2 tubular micromotor is a tubular fiber with an opening diameter of about 10 micrometers, mnO 2 is randomly distributed on the surface of the natural kapok tubular fiber, and the modification of MnO 2 does not damage the structure of the natural kapok tubular fiber. As can be seen from fig. 3B: the MnFe 2O4@MnO2 tubular micromotor is a tubular fiber with an opening diameter of about 10 micrometers, magnetic MnFe 2O4 nano particles are randomly distributed on the surface of the MnFe 2 tubular micromotor, and modification of the magnetic MnFe 2O4 nano particles does not damage the structure of the MnFe 2 tubular micromotor.
An X-ray energy dispersive spectroscopy (EDX) analysis was performed on the MnFe 2O4@MnO2 tubular micromotor prepared in example 2.
As shown in FIG. 4, the EDX element distribution of the MnFe 2O4@MnO2 tubular micro motor prepared in example 2. As can be seen in fig. 4: c, O, mn and Fe elements are uniformly distributed on the MnFe 2O4@MnO2 tubular micromotor. This demonstrates the successful modification of natural kapok tubular fibers with MnO 2 and magnetic MnFe 2O4 nanoparticles.
Scanning Electron Microscope (SEM) tests were performed on the Fe 3O4 tubular fibers and Fe 3O4@MnO2 tubular micromotors prepared in example 2.
As shown in fig. 5, SEM images of the Fe 3O4 tubular fiber and the Fe 3O4@MnO2 tubular micromotor prepared in example 2. As can be seen from fig. 5A: the Fe 3O4 tubular fiber is tubular fiber with an opening diameter of about 20 micrometers, magnetic Fe 3O4 nano particles are randomly distributed on the surface of the natural phoenix tree tubular fiber, and the modification of Fe 3O4 does not damage the structure of the natural phoenix tree tubular fiber. As can be seen from fig. 5B: the Fe 3O4@MnO2 tubular micromotor is a tubular fiber with an opening diameter of about 20 micrometers, mnO 2 is randomly distributed on the surface of the Fe 3O4 tubular fiber, and the modification of MnO 2 does not damage the structure of the Fe 3O4 tubular fiber.
An X-ray energy dispersive spectroscopy (EDX) analysis was performed on the Fe 3O4@MnO2 tubular micromotor prepared in example 2.
As shown in FIG. 6, the EDX element distribution of the Fe 3O4@MnO2 tubular micro motor prepared in example 2. As can be seen in fig. 6: c, O, mn and Fe elements are uniformly distributed on the Fe 3O4@MnO2 tubular micromotor. This demonstrates the successful modification of natural phoenix tree tubular fibers with MnO 2 and magnetic Fe 3O4 nanoparticles.
Example 3
In order to explore the longitudinal diffusion migration effect of the Mn/Fe composite catalysis tubular micro motor in soil, a soil filling column device for simulating a catalyst migration experiment is built.
As shown in fig. 7, the soil packing column device for the tubular micro-motor catalyst longitudinal migration test of example 3 specifically includes: and filling quartz sand (with a filling height of 30 cm) into a glass column with a water outlet at the lower end, adding 100mg of the Fe 3O4@MnO2 tubular micromotor catalyst prepared in the embodiment 1, then adding 100mL of deionized water or 3% hydrogen peroxide solution serving as flushing liquid into a liquid adding ball at the upper end, placing a beaker below the water outlet for collecting catalyst suspension, reacting for 30 minutes at room temperature, and photographing to record the migration effect of the Fe 3O4@MnO2 tubular micromotor catalyst in the column.
As shown in fig. 8, the overall comparison of the longitudinal diffusion migration effect of the static Fe 3O4@MnO2 tubular micromotor catalyst (rinse solution is deionized water) and the dynamic Fe 3O4@MnO2 tubular micromotor catalyst (rinse solution is hydrogen peroxide) in soil of example 3. As can be seen from fig. 8A: after 30 minutes, the longitudinal migration of the static Fe 3O4@MnO2 tubular micromotor catalyst in the soil-packed column was negligible. As can be seen from fig. 8B: within 30 minutes, the dynamic Fe 3O4@MnO2 tubular micromotor catalyst can migrate from the water injection end of the soil packing column to the water outlet end of the soil packing column.
As shown in fig. 9, a partial (water injection end and water outlet end) comparison graph of the longitudinal migration effect of the static Fe 3O4@MnO2 tubular micromotor catalyst (rinse solution is deionized water) and the dynamic Fe 3O4@MnO2 tubular micromotor catalyst (rinse solution is hydrogen peroxide) in soil of example 3. As can be seen from fig. 9A: after 30 minutes, the migration of the static Fe 3O4@MnO2 tubular micromotor catalyst at the water injection end of the soil filling column is negligible, and meanwhile, the migration of the catalyst to the water outlet end of the soil filling column is not observed, so that the passive diffusion migration behavior of the static Fe 3O4@MnO2 tubular micromotor catalyst in the soil is fully proved to be incapable of effectively diffusing the catalyst. As can be seen from fig. 9B: after 30 minutes, the obvious reduction of the dynamic Fe 3O4@MnO2 tubular micromotor catalyst at the water injection end of the soil filling column can be observed, and meanwhile, the color of the soil at the water outlet end of the soil filling column is changed from light to deep, so that the dynamic Fe 3O4@MnO2 tubular micromotor catalyst in the soil has active diffusion and migration behaviors.
Example 4
In order to explore the migration effect of different hydrogen peroxide concentration systems on a soil filling column of a self-driven Mn/Fe composite catalysis tubular micro motor, the soil filling column device constructed in the embodiment 3 is used at room temperature, the concentration of flushing liquid (hydrogen peroxide solution with the concentration of 1%, 2% and 3%) is changed, effluent at the water outlet end of the soil filling column is collected, and solid catalysts are centrifugally collected to compare the migration effect of different hydrogen peroxide concentration systems on dynamic catalysts.
As shown in fig. 10, the different hydrogen peroxide concentration systems of example 4 were tested for soil packing column migration recovery of self-driven Mn/Fe composite catalytic tubular micro-motors. As can be seen from fig. 10: after 30 minutes, the mass of the Mn/Fe composite catalysis tubular micro-motor collected by the effluent liquid gradually increases along with the increase of the concentration of the hydrogen peroxide flushing liquid, and the concentration of the flushing liquid is regulated to enhance the diffusion and migration behavior of the micro-motor-based catalyst in the soil packed column.
As shown in fig. 11, the different hydrogen peroxide concentration systems of example 4 versus soil packing column migration recovery ratio for the self-driven Mn/Fe complex catalyzed tubular micro-motor. The catalyst recovery mass ratio was calculated as m/m 0 x 100%, where m is the micro-motor based catalyst mass in the recovery liquid and m 0 is the initial loading of catalyst in the soil packing column. As can be seen from fig. 11: after 30 minutes, the mass ratio of the Mn/Fe composite catalysis tubular micro-motor collected by the effluent liquid gradually increases along with the increase of the concentration of the hydrogen peroxide flushing liquid, and when the concentration of the hydrogen peroxide flushing liquid reaches 3%, the catalyst recovery mass ratio can reach 69%, so that the active diffusion migration enhancement of the micro-motor-based catalyst in the soil is fully proved.
Example 5
In order to explore the transverse diffusion effect of Mn/Fe composite catalysis tubular micromotor catalyst in enhancing the catalyst in soil layer, firstly, an environment-friendly fluorescent indicator (g-C 3N4 nano sheet) is modified on Fe 3O4@MnO2 tubular micromotor by coprecipitation method to obtain CN-Fe 3O4@MnO2 tubular micromotor catalyst, and then, a catalyst migration experimental device simulating a planar soil layer is arranged.
As shown in fig. 12, the preparation of the CN-Fe 3O4@MnO2 tubular micromotor of example 5 specifically includes: 20g of melamine is placed in an alumina crucible with a cover and kept in a muffle furnace at 600 ℃ for 2 hours, and the temperature rising rate is 3 ℃ for min -1, so that a block yellow g-C 3N4 is obtained. Dispersing 100mg of blocky yellow g-C 3N4 in 100mL of water, performing ultrasonic treatment at room temperature for more than 5 hours, centrifuging at 5000 rotational speed for 20 minutes, collecting supernatant, and placing the product in a freeze dryer at minus 60 ℃ for 12 hours to obtain g-C 3N4 nanosheets; then, 20mg of Fe 3O4@MnO2 tubular micromotor was dispersed in an aqueous solution (4 mL) containing 5mg g-C 3N4 nanosheets, the product was collected by centrifugation and washed with a large amount of deionized water and ethanol, and the product was placed in a freeze dryer at-60℃for 12 hours to obtain a CN-Fe 3O4@MnO2 tubular micromotor.
As shown in fig. 13, the soil layer device for the catalyst lateral diffusion migration test of example 5 specifically includes: spreading a layer of soil (soil thickness is 0.5 cm) in a surface dish, adding 100mg of the prepared CN-Fe 3O4@MnO2 tubular micromotor catalyst at the center point of the soil, then adding 10mL of deionized water or 3% hydrogen peroxide solution as flushing liquid, reacting for 3 minutes at room temperature under irradiation of an ultraviolet lamp with wavelength of 365nm, observing with naked eyes, photographing and recording the autonomous migration effect of the CN-Fe 3O4@MnO2 tubular micromotor catalyst on the soil layer.
As shown in FIG. 14, the static CN-Fe 3O4@MnO2 tubular micro-motor and the self-driven CN-Fe 3O4@MnO2 tubular micro-motor of example 5 were subjected to a lateral diffusion migration experiment in a soil layer. As can be seen from fig. 14A: the passive diffusion migration behavior of the static CN-Fe 3O4@MnO2 tubular micromotor in the planar soil layer is very little, and the catalyst is still at the sample adding point. As can be seen from fig. 14B: the obvious self-driven CN-Fe 3O4@MnO2 tubular micromotor enhances the active diffusion and migration in a planar soil layer, and fully proves that the transverse migration efficiency of the self-driven CN-Fe 3O4@MnO2 tubular micromotor catalyst in the soil is enhanced through the actions of autonomous movement, active diffusion and generated bubbles. In particular, the migration effect of the micro-motor-based catalyst in the soil is directly observed by naked eyes, sample pretreatment is not needed, a large-sized element analysis instrument is not needed, and the migration effect of the catalyst can be clarified.
Example 6
To investigate the longitudinal diffusion effect of the self-driven CN-Fe 3O4@MnO2 tubular micromotor catalyst prepared in example 5 in enhancing the catalyst in a soil-packed column and the optical calculation method of catalyst mobility, a catalyst migration experimental apparatus simulating a soil-packed column (containing 3 sampling points) was set.
As shown in fig. 15, the catalyst migration test apparatus for the soil-packed column (including 3 sampling points) of example 6 specifically includes: filling quartz sand (filling height is 20 cm) into a glass column with a water outlet at the lower end, adding 100mg of CN-Fe 3O4@MnO2 tubular micromotor catalyst prepared in example 5, then adding 20mL of deionized water or hydrogen peroxide solution with concentration of 1%, reacting for 30 minutes at room temperature, respectively sucking 0.5mL of effluent at three sampling points at a certain time interval, observing solid precipitation in the photographed effluent under a microscope with an ultraviolet lamp configuration, counting the fluorescence intensity of a picture by using a microscope system, comparing the migration effect of a static catalyst and a dynamic catalyst in the soil filled column, and calculating the mobility of the catalyst.
As shown in FIG. 16, the mobility calculation results in the soil packed column were obtained for the static CN-Fe 3O4@MnO2 tubular micro motor and the self-driven CN-Fe 3O4@MnO2 tubular micro motor of example 6. The ratio of fluorescence intensities of the catalysts was calculated as F/F 0 x 100%, where F is the fluorescence intensity of the solid precipitate in the collection fluid and F 0 is the fluorescence intensity of the solid precipitate in the collection fluid at 0 minutes at the sampling point. As can be seen from fig. 16A: within 30 minutes, the fluorescence intensity ratio of the sampling point was hardly reduced, the fluorescence intensity ratio of the sampling point was slightly increased and then reduced, and the increase of the fluorescence intensity ratio of the sampling point was negligible. This shows that within 30 minutes, the passive diffusion migration behavior of the static CN-Fe 3O4@MnO2 tubular micromotor in the soil packed column was very small, and the catalyst was always at the initial loading point. As can be seen from fig. 16B: within 30 minutes, the fluorescence intensity ratio at sample point ① was significantly reduced, and the fluorescence intensity ratio at sample point ② was significantly increased and then suddenly decreased, and the fluorescence intensity ratio at sample point ③ was sharply increased. This indicates that within 30 minutes, the self-driven CN-Fe 3O4@MnO2 tubular micromotor has enhanced active diffusion and migration in the soil packed column, which fully demonstrates the enhanced migration efficiency of the self-driven CN-Fe 3O4@MnO2 tubular micromotor catalyst in the soil through autonomous movement, active diffusion and the action of the generated bubbles. Particularly, by utilizing the fluorescence characteristic of the catalyst, the method can examine the migration effect of the micromotor-based catalyst in the soil by only analyzing the fluorescence ratio of the taken trace sample, does not need sample pretreatment and large-scale elemental analysis instrument, and can completely realize the evaluation of the autonomous migration efficiency of the fluorescent catalyst in the soil. The proposed visual statistical strategy of catalyst migration efficiency in the soil environment is fully viable.
Example 7
To investigate the degradation efficiency of different catalytic systems on tetracycline contaminated soil, 5g of tetracycline contaminated soil (400 mg kg -1) was reacted with different catalysts in a beaker at room temperature to compare the catalytic degradation performance of the different catalytic systems. Wherein, the concentration of the MnFe 2O4@MnO2 tubular micromotor catalyst is 1mg mL -1, the concentration of hydrogen peroxide is 1%, and the concentration of PMS is 5mM. At regular time intervals, 2mL of the solution and 3mL of the extract were aspirated, sonicated for 5 minutes, the supernatant was collected by centrifugation, and the supernatant was filtered with a 0.22 μm filter head. The resulting solution was immediately used to determine the concentration of tetracycline using an ultraviolet-visible spectrophotometer.
As shown in FIG. 17, a graph comparing the degradation efficiency of the different catalytic systems of example 7 on tetracycline contaminated soil. Firstly, comparing fold lines A and B, the degradation efficiency of the tetracycline is only 20% after 30 minutes when 1% hydrogen peroxide exists in the solution; in contrast, when only 5mM PMS was present in the solution, the tetracycline degradation efficiency reached only 40% after 30 minutes. In addition, fold line C demonstrates that when the catalytic system contains both hydrogen peroxide (1%) and PMS (5 mM), the tetracycline degradation efficiency reaches 30%. Furthermore, comparing fold lines B, C and E, it was found that when PMS and MnO 2 tubular micromotors were present in the solution at the same time, the tetracycline degradation efficiency reached about 60% after 5 minutes, and the tetracycline degradation efficiency increased slowly to 65% after 30 minutes, thus proving that the MnO 2 tubular micromotors could effectively activate PMS, thereby effectively promoting the tetracycline degradation. The degradation phenomenon of this process is due to oxidative decomposition of tetracycline by the strong oxidative SO 4 ·- generated by the activation of PMS by the micromotor. Similarly, comparing fold lines A, C and D, it is found that when hydrogen peroxide and MnO 2 tubular micromotors exist in the solution at the same time, the degradation efficiency of tetracycline only reaches about 40% after 5 minutes, and reaches about 60% after 30 minutes, so that the micromotors can be proved to react with hydrogen peroxide, and further effectively degrade tetracycline. The degradation phenomenon of the process is attributed to Fenton-like oxidation reaction of OH generated by decomposing hydrogen peroxide by the micro motor on tetracycline, and the micro motor has self-stirring and self-diffusion, so that the contact mass transfer process of the catalyst and pollutants and the self-diffusion effect of the catalyst in a soil remediation area are enhanced, and the pollutant degradation efficiency is improved. Fold lines C and G prove that MnFe 2O4 can activate PMS and hydrogen peroxide to enhance the degradation efficiency of tetracycline. Finally, from the broken line H, when PMS, hydrogen peroxide and MnFe 2O4@MnO2 tubular micromotor catalyst are simultaneously present in the solution, the degradation efficiency of the tetracycline can reach more than 90% after 30 minutes. In particular, fold lines F, G and H demonstrate the feasibility of MnFe 2O4@MnO2 heterojunction to tetracycline degradation. The degradation efficiency of the MnFe 2O4@MnO2 tubular micromotor catalyst on tetracycline is larger than that of the MnO 2 tubular micromotor catalyst, because MnFe 2O4 and MnO 2 can jointly strengthen the oxidation reaction of activated hydrogen peroxide and PMS. In a word, the MnFe 2O4@MnO2 tubular micromotor catalyst obtained in the embodiment 2 can utilize Fenton-like oxidation reaction activated based on a hydrogen peroxide/persulfate compound system, so that the catalyst can efficiently degrade tetracycline. And the autonomous movement of the catalyst and the generated bubbles can cause self-stirring in the soil, the autonomous diffusion and migration are enhanced, the mixing of pollutants, an oxidant and the catalyst is accelerated, and the degradation efficiency is remarkably improved.
Example 8
To investigate the degradation efficiency of different catalytic systems on norfloxacin contaminated soil, 5g of norfloxacin contaminated soil (40 mg kg -1) was reacted with different catalysts in a beaker at room temperature to compare the catalytic degradation performance of different catalytic systems. Wherein, the concentration of the Fe 3O4@MnO2 tubular micromotor catalyst is 5mg mL -1, the concentration of hydrogen peroxide is 1%, and the concentration of PMS is 1mM. At regular time intervals, 2mL of the solution and 3mL of the extract were aspirated, sonicated for 5 minutes, the supernatant was collected by centrifugation, and the supernatant was filtered with a 0.22 μm filter head. The resulting solution was immediately used to determine the concentration of norfloxacin using an ultraviolet-visible spectrophotometer.
As shown in fig. 18, a graph comparing the degradation efficiency of the different catalytic systems of example 8 on norfloxacin contaminated soil. Firstly, comparing fold lines A and B, the degradation efficiency of norfloxacin can be ignored after 15 minutes when only 1% hydrogen peroxide exists in the solution; similarly, when only 1mM PMS was present in the solution, the norfloxacin degradation efficiency reached only about 5% after 15 minutes. Secondly, fold line C demonstrates that the degradation efficiency of norfloxacin is very low after 15 minutes when only Fe 3O4@MnO2 tubular micromotor catalyst is present in the solution, thus eliminating the adsorption of norfloxacin by the micromotor-based catalyst. Furthermore, comparing fold lines B, C and D, it was found that when PMS and Fe 3O4@MnO2 tubular micromotors were present in the solution at the same time, the degradation efficiency of norfloxacin could reach about 40% after 15 minutes, and therefore, it could be proved that Fe 3O4@MnO2 tubular micromotors could effectively activate PMS, thereby effectively promoting the degradation of norfloxacin. The degradation phenomenon of the process is attributed to Fenton-like oxidative decomposition of SO 4 ·- p-norfloxacin generated by PMS activation by a modified Fe 3O4@MnO2 heterojunction on a micro-motor. Similarly, comparing fold lines A, C and E, it is found that when hydrogen peroxide and the micromotor are simultaneously present in the solution, the degradation efficiency of norfloxacin can reach about 80% after 15 minutes, so that it can be proved that the micromotor can react with hydrogen peroxide, and further effectively degrade norfloxacin. The degradation phenomenon in the process is attributed to Fenton-like oxidation reaction of the high-oxidability OH para-norfloxacin generated by decomposing hydrogen peroxide by the micromotor. Finally, as seen from the broken line F, when PMS, hydrogen peroxide and Fe 3O4@MnO2 tubular micromotors are simultaneously present in the solution, the degradation efficiency of norfloxacin can reach about 90% after 15 minutes. In a word, the Fe 3O4@MnO2 tubular micromotor catalyst obtained in the embodiment 2 can utilize Fenton-like oxidation reaction activated based on a hydrogen peroxide/persulfate compound system, so that the catalyst can efficiently degrade norfloxacin. And the autonomous movement of the catalyst and the generated bubbles can cause self-stirring in the soil, the autonomous diffusion and migration are enhanced, the mixing of pollutants, an oxidant and the catalyst is accelerated, and the degradation efficiency is remarkably improved.
Example 9
To investigate the degradation efficiency of different catalytic systems on fluoranthene-contaminated soil, 5g of fluoranthene-contaminated soil (40 mg kg -1) was reacted with different catalysts in a beaker at room temperature to compare the catalytic degradation performance of different catalytic systems. Wherein, the concentration of the Fe 3O4@MnO2 tubular micromotor catalyst is 5mg mL -1, the concentration of hydrogen peroxide is 1%, and the concentration of PMS is 1mM. At defined time intervals, 1mL of the solution was aspirated with 4mL of ethanol, sonicated for 15 minutes, the supernatant collected by centrifugation, and the supernatant filtered with a 0.22 μm filter head. The resulting solution was immediately used to determine the concentration of fluoranthene using a fluorescence spectrophotometer.
As shown in fig. 19, a graph comparing the degradation efficiency of the different catalytic systems of example 9 on fluoranthene-contaminated soil. Firstly, comparing fold lines A and B, the degradation efficiency of fluoranthene can be ignored after 180 minutes when only 1% hydrogen peroxide exists in the solution; similarly, when only 1mM PMS was present in the solution, the degradation efficiency of fluoranthene reached only about 10% after 180 minutes. Second, fold line C demonstrates that when only Fe 3O4@MnO2 tubular micromotor catalyst is present in the solution, the fluoranthene degradation efficiency is very low after 180 minutes, thus eliminating the adsorption of fluoranthene by the micromotor-based catalyst. Furthermore, comparing fold lines B, C and E, it was found that when PMS and Fe 3O4@MnO2 tubular micromotors are present in the solution at the same time, the degradation efficiency of fluoranthene can reach about 50% after 180 minutes, so that it can be proved that Fe 3O4@MnO2 tubular micromotors can effectively activate PMS, thereby effectively promoting degradation of fluoranthene. The degradation phenomenon of the process is attributed to Fenton-like oxidative decomposition of SO 4 ·- on fluoranthene generated by PMS activation by a modified Fe 3O4@MnO2 heterojunction on a micro-motor. Similarly, comparing fold lines A, C and D, it is found that when hydrogen peroxide and the micromotor are simultaneously present in the solution, the degradation efficiency of fluoranthene can reach about 70% after 180 minutes, so that it can be proved that the micromotor can react with hydrogen peroxide, and further effectively degrade fluoranthene. The degradation phenomenon in the process is attributed to Fenton-like oxidation reaction of fluoranthene by strong oxidability OH generated by decomposing hydrogen peroxide by a micro motor. Finally, as seen from the broken line F, when PMS, hydrogen peroxide and Fe 3O4@MnO2 tubular micromotors are simultaneously present in the solution, the degradation efficiency of fluoranthene can reach about 80% after 180 minutes. In a word, the Fe 3O4@MnO2 tubular micromotor catalyst obtained in the embodiment 2 can utilize Fenton-like oxidation reaction activated based on a hydrogen peroxide/persulfate compound system, so that the catalyst can efficiently degrade fluoranthene. And the autonomous movement of the catalyst and the generated bubbles can cause self-stirring in the soil, the autonomous diffusion and migration are enhanced, the mixing of pollutants, an oxidant and the catalyst is accelerated, and the degradation efficiency is remarkably improved.
Claims (6)
1. The preparation method of the self-driven Mn/Fe composite plant fiber tubular micromotor catalyst for in-situ remediation of polluted water and soil is characterized by comprising the following steps of:
(1) Cutting plant fibers with a hollow tubular structure, wherein the length of the plant fibers is between the diameter of the fibers and 1 millimeter, so as to obtain a tubular plant fiber template;
(2) Modifying MnO2 on a tubular plant fiber template, and loading MnFe2O4 or Fe3O4 composite catalytic material to obtain a self-driven Mn/Fe composite plant fiber tubular micromotor;
the Mn/Fe composite catalytic material in the self-driven Mn/Fe composite plant fiber tubular micro-motor is MnFe2O4@MnO2 or Fe3O4@MnO2; the MnO2 modification method is an impregnation method or a hydrothermal method; the Fe3O4 loading method is a hydrothermal method; the MnFe2O4 loading method is a co-deposition method.
2. The method for preparing the self-driven Mn/Fe composite plant fiber tubular micromotor catalyst for in-situ remediation of polluted water and soil according to claim 1, wherein the hydrothermal method for loading Fe3O4 is characterized in that tubular plant fiber templates are dispersed in an ethylene glycol solution containing ferric chloride, sodium citrate and sodium acetate, and the mixture is kept in a hydrothermal kettle at 200 ℃ for 12 hours.
3. The preparation method of the self-driven Mn/Fe composite plant fiber tubular micromotor catalyst for in-situ remediation of polluted water and soil, according to claim 1, is characterized in that the MnO2 is modified by an impregnation method, wherein a tubular plant fiber template is dispersed in a potassium permanganate solution, and the tubular plant fiber template is placed and soaked for 3-72 hours.
4. The method for preparing the self-driven Mn/Fe composite plant fiber tubular micromotor catalyst for in-situ remediation of polluted water and soil according to claim 1, wherein the modification of MnO2 by a hydrothermal method is to disperse tubular plant fibers loaded with Fe3O4 in a potassium permanganate solution containing hydrochloric acid, and keep the solution in a hydrothermal kettle at 100 ℃ for 6 hours.
5. The method for preparing a self-driven Mn/Fe composite plant fiber tubular micromotor catalyst for in-situ remediation of contaminated water and soil according to claim 1, wherein the co-deposition modification of MnFe2O4 is carried out by dispersing tubular plant fibers modified with MnO2 in an aqueous solution containing magnetic MnFe2O4 nanoparticles and shaking at room temperature for more than one day.
6. The application of the self-driven Mn/Fe composite plant fiber tubular micromotor catalyst is characterized in that the self-driven Mn/Fe composite plant fiber tubular micromotor prepared by the method of any one of claims 1-5 is used in-situ soil and water remediation, and meanwhile, the prepared self-driven Mn/Fe composite plant fiber tubular micromotor and hydrogen peroxide or hydrogen peroxide-persulfate compound system are added.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108675430A (en) * | 2018-05-15 | 2018-10-19 | 吉林大学 | Generate potentiometric titrations and the catalysis process of active oxygen species and the advanced oxidization method of difficult for biological degradation organic pollution |
| CN109576986A (en) * | 2018-12-21 | 2019-04-05 | 福建工程学院 | A kind of multilayer that bombax cotton/manganese dioxide is constructed is from driving tubulose micro-nano motor and preparation method thereof |
| CN110038518A (en) * | 2019-04-29 | 2019-07-23 | 济南大学 | A kind of ZIF-8 magnetism that size is controllable driving micro-pipe motor adsorbent and its application certainly |
| CN110327987A (en) * | 2019-06-11 | 2019-10-15 | 济南大学 | A kind of polymer Janus micro motor preparation method based on liquid liquid phase separation |
| CN113134359A (en) * | 2021-03-10 | 2021-07-20 | 厦门和健卫生技术服务有限公司 | alpha-MnO2/MnFe2O4Preparation method of composite catalytic material, composite catalytic material and application |
| CN113856698A (en) * | 2021-11-12 | 2021-12-31 | 中国矿业大学 | Preparation method and application of high-efficiency self-driven catalyst based on Fenton-like reaction and PMS (permanent magnet synchronous motor) activation |
-
2022
- 2022-10-18 CN CN202211273687.7A patent/CN115634714B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108675430A (en) * | 2018-05-15 | 2018-10-19 | 吉林大学 | Generate potentiometric titrations and the catalysis process of active oxygen species and the advanced oxidization method of difficult for biological degradation organic pollution |
| CN109576986A (en) * | 2018-12-21 | 2019-04-05 | 福建工程学院 | A kind of multilayer that bombax cotton/manganese dioxide is constructed is from driving tubulose micro-nano motor and preparation method thereof |
| CN110038518A (en) * | 2019-04-29 | 2019-07-23 | 济南大学 | A kind of ZIF-8 magnetism that size is controllable driving micro-pipe motor adsorbent and its application certainly |
| CN110327987A (en) * | 2019-06-11 | 2019-10-15 | 济南大学 | A kind of polymer Janus micro motor preparation method based on liquid liquid phase separation |
| CN113134359A (en) * | 2021-03-10 | 2021-07-20 | 厦门和健卫生技术服务有限公司 | alpha-MnO2/MnFe2O4Preparation method of composite catalytic material, composite catalytic material and application |
| CN113856698A (en) * | 2021-11-12 | 2021-12-31 | 中国矿业大学 | Preparation method and application of high-efficiency self-driven catalyst based on Fenton-like reaction and PMS (permanent magnet synchronous motor) activation |
Non-Patent Citations (3)
| Title |
|---|
| Fe3O4/MnO2磁性复合氧化物催化剂的制备及性能;吴光锐等;《复合材料学报》;第36卷(第1期);147-158 * |
| Peroxymonosulfate activation by α-MnO2/MnFe2O4 for norfloxacin degradation: Efficiency and mechanism;Lv Si Xu et al.;《Journal of Physics and Chemistry of Solids》;第153卷;110029:1-10 * |
| 邓春晖等.《磁性微纳米材料在蛋白质组学中的应用》.上海：复旦大学出版社,2017,(第1版),50. * |
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