A method for preparing nano-zero-valent mineral-based ternary functional materials by roasting natural iron-containing nano-minerals and its application

Abstract

A method for preparing nano-zero-valent mineral-based ternary functional materials by roasting natural iron-containing nano-minerals and its application relate to the technical field of microplastic degradation and treatment. Crushed and sieved natural pyrite is mixed with copper ore, laterite nickel-iron ore, and phosphite powders, or natural laterite nickel-iron ore and copper ore powders are mixed separately and stirred with water until uniform mixing is achieved. The mixture is then dried and roasted and pyrolyzed in hydrogen to produce nano-zero-valent iron-copper-sulfur, iron-nickel-sulfur, iron-phosphorus-sulfur, and iron-nickel-copper mineral-based ternary functional materials, respectively. These materials have a highly open pore structure, a large specific surface area, and a high number of hydroxyl functional groups on their surfaces, resulting in high reactivity. The nano-zero-valent mineral-based ternary functional materials are then combined with persulfate to form a heterogeneous, advanced oxidation system, catalyzing the persulfate to produce highly oxidative free radicals, enabling efficient and rapid degradation of microplastics. These materials are widely applicable as functional materials in various fields, such as water treatment and ecological restoration.

Description

Technical Field

[0001] The present invention relates to the technical field of microplastic degradation treatment, and in particular to a method for preparing nano zero-valent mineral-based ternary functional materials by roasting natural iron-containing nano minerals and applications thereof. Background Art

[0002] With the development of industry in recent years, microplastics with three-dimensional dimensions less than 5mm have gradually become emerging pollutants that have attracted much attention in the environmental field. At present, the most common process for treating microplastics is advanced oxidation technology. Advanced oxidation technology, also known as deep oxidation technology, is characterized by the production of active free radicals with strong oxidizing ability. Under reaction conditions such as high temperature and high pressure, electricity, sound, light irradiation, and catalysts, large-molecule refractory organic matter is oxidized into low-toxic or non-toxic small-molecule substances. Among them, the advanced oxidation process based on persulfate has its own unique advantages and is considered to be one of the effective methods for treating microplastics in water bodies. It mainly produces highly active hydroxyl radicals and sulfate radicals after being activated. These two free radicals have high oxidation potentials and can effectively degrade organic pollutants in water bodies, thereby achieving efficient removal of organic pollutants.

[0003] Currently, heterogeneous catalysts with transition metals such as Fe, Ni, and Cu as active centers are the most common catalysts for advanced oxidation processes. Fe-based materials have attracted considerable attention due to their environmental friendliness. Common ferrous minerals such as ferrophosphite and ferrous carbonate have been shown to have the ability to act as catalysts for advanced oxidation processes, but they generally suffer from low catalytic efficiency and weak pollutant degradation capabilities. Therefore, developing an environmentally friendly, low-cost, and catalytically active Fe-based material for use in the treatment of microplastics through advanced oxidation processes is of practical significance.

[0004] Based on previous research, the applicants discovered that combining nano-zero-valent mineral-based ternary functional materials with persulfate technology can form an effective advanced oxidation technology with high catalytic performance, which can improve reaction efficiency. Currently, there are no reports of using nano-zero-valent mineral-based ternary functional materials as catalysts for the catalytic degradation of microplastics. Summary of the Invention

[0005] The purpose of the present invention is to provide a process with simple process and high treatment efficiency, using nano zero-valent mineral-based ternary functional materials as catalysts to form a heterogeneous advanced oxidation system with persulfate, catalyzing persulfate to produce highly oxidizing free radicals, which can efficiently and rapidly degrade microplastics, thereby overcoming the shortcomings of traditional advanced oxidation reactions, such as low catalytic efficiency and easy passivation and deactivation of catalytic materials, resulting in poor catalytic degradation of microplastics.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] First, the present invention proposes a method for preparing nano-zero-valent mineral-based ternary functional materials by roasting natural iron-containing nano-minerals, the steps of which are as follows:

[0008] (1) crushing natural pyrite, natural copper ore, natural laterite nickel iron ore, and natural phosphite, and passing through a 200-mesh sieve to obtain various mineral powders;

[0009] (2) Natural pyrite powder and natural copper ore powder, natural pyrite powder and natural laterite nickel-iron ore powder, natural pyrite powder and natural phosphite powder, natural laterite nickel-iron ore powder and natural copper ore powder are mixed respectively and water is added to stir and mix evenly, and then the water is dried and hydrogen roasted and pyrolyzed to obtain nano zero-valent iron copper-sulfur mineral ternary functional materials, nano zero-valent iron nickel-sulfur mineral ternary functional materials, nano zero-valent iron phosphorus-sulfur mineral ternary functional materials, and nano zero-valent iron nickel-copper mineral ternary functional materials.

[0010] As a preferred technical solution of the present invention, the mass ratio of the natural pyrite powder to the natural phosphotyrite powder, natural copper ore powder, or natural laterite nickel-iron ore powder, or the natural laterite nickel-iron ore to the natural copper ore, is 2-5:1. The roasting and pyrolysis process is performed at 500-800°C for 1-5 hours in a hydrogen reducing atmosphere to prepare the nano-zero-valent mineral-based ternary functional material. The amount of water added in step (2) is 30-50% of the mass of the mixed powder.

[0011] Secondly, the present invention also proposes the application of the nano zero-valent mineral-based ternary functional material in the catalytic degradation of microplastics. Specifically, the nano zero-valent mineral-based ternary functional material is used as a catalyst to form a heterogeneous advanced oxidation system with persulfate, which catalyzes persulfate to produce highly oxidizing free radicals, thereby being able to efficiently and rapidly degrade microplastics.

[0012] As a preferred technical solution of the present invention, in the process of catalytic degradation of microplastics, nano-zero-valent mineral-based ternary functional materials and persulfate are directly added to the wastewater containing microplastics to catalyze the persulfate to oxidatively degrade the microplastics in the wastewater; in the degradation system formed, the concentration of nano-zero-valent mineral-based ternary functional materials is 0.05-10g / L, the concentration of persulfate is 0.1-5mmol / L, the concentration of microplastics is 0.1-10g / L, and the degradation treatment time is 0.1-10h.

[0013] The persulfate is selected from peroxymonosulfate or peroxydisulfate, and the microplastic material for catalytic degradation is one or more of polystyrene (PS), polyethylene (PE), nylon (PA), polycarbonate (PC), polypropylene (PP), polyethylene terephthalate (PET), and polyvinyl chloride (PVC).

[0014] The nanometer zero-valent mineral-based ternary functional material prepared by the present invention has a highly open pore structure, a large specific surface area, and a large number of hydroxyl functional groups on the surface, which has high reactivity. In the process of catalytic degradation of microplastics, persulfate is catalyzed by the nanometer zero-valent mineral-based ternary functional material to produce sulfate radicals (SO4· - ), hydroxyl radicals (·OH) and peroxyhydroxyl radicals (HO2· - ). At the same time, it will accelerate HO2 v- To superoxide radicals (O2· - ) conversion and O2· - itself, thereby generating singlet oxygen ( 1 O2). In addition, ·OH and HO2· - The reaction between the two and the self-decomposition of persulfate will also produce 1 O2. Produced during the process of persulfate catalysis by nano-zero-valent mineral-based ternary functional materials 1 O2 can selectively attack microplastics containing electron-rich groups, thereby achieving rapid oxidation and degradation of microplastics.

[0015] Compared with the prior art, the beneficial effects of the present invention are mainly manifested in:

[0016] 1. The iron-containing nanominerals employed in the present invention exhibit high adsorption, large specific surface area and ion exchange capacity, high chemical reactivity, and high thermal decomposition activity. These nanominerals possess nanoscale effects and properties, making them valuable for development and application. A key characteristic of iron-containing nanomineral resources is that they are composed of one or more nanominerals or mineral nanoparticles, typically containing non-nanomineral particles. Their mineral compositions are complex and their chemical compositions vary widely.

[0017] 2. The iron-containing nano-mineral resources used in the present invention are abundant in resources, cheap in raw materials, environmentally friendly, have natural porous structures, are easy to achieve nanostructuring, and have simple processing technology; they contain variable valence elements and can be converted into functional materials with various valence states and structural states. The mechanisms for removing pollutants include: adsorption, catalysis, precipitation, chemical oxidation, chemical reduction, and microbial electron donors or electron acceptors; they have a wide range of applications and can be used as functional materials in various fields including water treatment and ecological restoration.

[0018] 3. The nano-zero-valent mineral-based ternary functional materials prepared by the present invention are derived from green, environmentally friendly, inexpensive, and readily available minerals and rocks such as natural phosphotyrite, natural pyrite, natural copper ore, and natural laterite nickel-iron ore, and can be directly crushed and screened. The prepared nano-zero-valent mineral-based ternary functional materials have a rich nanopore structure and micropore structure, and tiny nano-zero-valent nickel, copper, iron, phosphorus, and sulfur particles are evenly distributed within the material. These particles can serve as active sites, forming micro-primary cells to generate hole charges, synergistically promoting the effective improvement of the catalytic oxidation activity of the nano-zero-valent mineral-based ternary functional materials. Furthermore, the nano-zero-valent mineral-based ternary functional material particles are evenly dispersed, effectively solving the agglomeration and passivation problem of nanoparticles prepared by traditional methods, further improving the efficiency of catalytic degradation of microplastics.

[0019] 4. The present invention utilizes a hydrogen-protected atmosphere for mixing and calcining, resulting in a simple and easily controllable synthesis process with high reaction efficiency, simple, safe, and reliable operation, low production cost, and zero pollutant emissions during the preparation process. This nano-zero-valent mineral-based ternary functional material exhibits excellent catalytic performance, enabling rapid oxidative degradation of microplastics while significantly reducing the use of persulfate. Furthermore, this material exhibits good stability and, after recycling, maintains a high degradation rate for microplastics under the same conditions. This catalyst has broad application prospects.

[0020] 5. The nano-zero-valent mineral-based ternary functional material prepared by this invention is used for the catalytic degradation of microplastics. It exhibits good catalytic activity against persulfate over a wide pH range (pH 2-14), possesses strong acid-base buffering capacity, strong resistance to anionic interference, and is easy to precipitate and separate. Furthermore, since the catalyst contains no toxic or harmful elements, it can avoid secondary pollution problems that may arise during the catalyst's use and recovery processes, and has broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a physical picture of iron-containing nanominerals.

[0022] Figure 2 This is the XRD spectrum of ternary functional materials based on iron-containing nano-minerals and nano-zero-valent minerals.

[0023] Figure 3 This is the SEM image of natural phosphotyrite.

[0024] Figure 4 This is the SEM image of natural pyrite.

[0025] Figure 5 This is the SEM image of the nano zero-valent iron-nickel-sulfur mineral ternary functional material.

[0026] Figure 6 This is the SEM image of natural copper ore.

[0027] Figure 7 This is the SEM image of the nano zero-valent iron copper sulfur mineral ternary functional material.

[0028] Figure 8 This is the SEM image of natural laterite nickel iron ore.

[0029] Figure 9 This is the SEM image of the nano zero-valent iron-nickel-copper mineral ternary functional material.

[0030] Figure 10 This is the TEM image of the nano-zero-valent iron phosphorus-sulfur mineral ternary functional material.

[0031] Figure 11 This is the TEM image of nano zero-valent iron-nickel-sulfur mineral ternary functional material.

[0032] Figure 12 This is the TEM image of nano zero-valent iron copper sulfur mineral ternary functional material. DETAILED DESCRIPTION

[0033] The following is a detailed explanation of the method for preparing nano-zero-valent mineral-based ternary functional materials by roasting natural ores and its application in catalytic degradation of microplastics proposed by the present invention, in combination with the examples and the accompanying drawings.

[0034] Example 1

[0035] First, the present invention crushes natural pyrite, natural copper ore, natural laterite nickel iron ore, and natural phosphite, and passes through a 200-mesh sieve to obtain various mineral powders; the natural minerals used are as follows: Figure 1 As shown, A is natural laterite nickel iron ore, B is natural phosphotyrite, C is natural copper ore, and D is natural pyrite.

[0036] Secondly, natural pyrite powder and natural copper ore powder, natural pyrite powder and natural laterite nickel-iron ore powder, natural pyrite powder and natural phosphite powder, natural laterite nickel-iron ore powder and natural copper ore powder are mixed respectively and water is added to stir and mix evenly, and then the moisture is dried and hydrogen roasted and pyrolyzed to obtain nano zero-valent iron copper-sulfur mineral ternary functional materials, nano zero-valent iron nickel-sulfur mineral ternary functional materials, nano zero-valent iron phosphorus-sulfur mineral ternary functional materials, and nano zero-valent iron nickel-copper mineral ternary functional materials, respectively.

[0037] The natural minerals used in the present invention and the prepared nano zero-valent mineral-based ternary functional materials are characterized by their structural morphology as follows:

[0038] Figure 2 The XRD patterns of the iron-containing nano-mineral (A) and the nano-zero-valent mineral-based ternary functional material (B). Figure 2A is the XRD pattern of natural phosphotyrite and natural copper ore. It can be seen from the figure that natural copper ore has a strong characteristic diffraction peak, indicating that its crystallinity is good. Natural phosphotyrite can see the characteristic diffraction peaks of hematite and phosphotyrite, indicating that natural phosphotyrite has good crystallinity. Figure 2 B is the XRD pattern of the nano-zero-valent mineral-based ternary functional material. The figure shows strong characteristic diffraction peaks. All three nano-zero-valent mineral-based ternary functional materials exhibit the characteristic diffraction peak of nano-zero-valent iron. Furthermore, the nano-zero-valent iron-copper-sulfur mineral ternary functional material also exhibits the characteristic diffraction peak of nano-zero-valent copper. The nano-zero-valent iron-nickel-sulfur mineral ternary functional material also exhibits the characteristic diffraction peak of nano-zero-valent nickel. The nano-zero-valent iron-nickel-copper mineral ternary functional material also exhibits the characteristic diffraction peaks of nano-zero-valent copper and nano-zero-valent nickel.

[0039] Figure 3 This is a SEM image of natural phosphotyrite, with (A)-(F) representing different scales. The image shows that natural phosphotyrite has a dense structure, low porosity, and a small specific surface area. This massive morphology is attributed to its high crystallinity.

[0040] Figure 4 SEM images of natural pyrite (A)-(D) represent different scales. The images show that natural pyrite is plate-like, has a certain nanostructure, and has a rough, folded surface.

[0041] Figure 5 SEM images of a nanoscale zero-valent iron, nickel, and sulfur ternary functional material prepared from natural laterite nickel iron ore and natural pyrite by calcining at 700°C for 2 hours in a hydrogen reducing atmosphere. (A)-(C) represent different scales. As can be seen, the nanoscale zero-valent iron, nickel, and sulfur ternary composite material exhibits a porous structure with open pores, high activity, and a large specific surface area, making it suitable for use as a catalyst.

[0042] Figure 6 SEM images of natural copper ore, with (A)-(E) representing different scales. As can be seen from the images, natural copper ore has a dense structure, small specific surface area, low activity, and material particles exhibiting blocky and plate-like morphologies.

[0043] Figure 7 SEM images of a nanoscale zero-valent iron, copper, and sulfur ternary functional material prepared from natural pyrite and copper ore by calcining at 700°C for 2 hours in a hydrogen-reducing atmosphere. (A)-(D) represent different scales. As can be seen, the nanoscale zero-valent iron, copper, and sulfur ternary functional material forms a porous structure, nanoparticles, and exhibits high activity.

[0044] Figure 8These are SEM images of natural laterite nickel iron ore, with (A)-(C) representing different scales. As can be seen from the images, natural laterite nickel iron ore exhibits a plate-like, large-granular morphology, low porosity, low activity, and small specific surface area.

[0045] Figure 9 SEM images of a nanoscale zero-valent iron, nickel, and copper mineral ternary functional material prepared from natural laterite nickel-iron ore and natural copper ore by calcining at 700°C for 2 hours in a hydrogen reducing atmosphere. (A)-(D) represent different scales. As can be seen, the nanoscale zero-valent iron, nickel, and copper mineral ternary functional material forms a porous structure, nanoparticles, and exhibits high activity.

[0046] Figure 10 TEM images of a nanoscale zero-valent iron phosphorus-sulfur mineral ternary functional material prepared from natural phosphotyrite and natural pyrite by calcining at 700°C for 2 hours in a hydrogen reducing atmosphere. (A)-(D) represent different scales. As can be seen, the nanoscale zero-valent iron phosphorus-sulfur mineral ternary functional material forms a porous structure, nanoparticles, and exhibits high activity.

[0047] Figure 11 TEM images of a nanoscale zero-valent iron, nickel, and sulfur ternary functional material prepared from natural laterite nickel iron ore and natural pyrite by calcining at 700°C for 2 hours in a hydrogen reducing atmosphere. (A)-(D) represent different scales. As can be seen, the nanoscale zero-valent iron, nickel, and sulfur ternary functional material forms a porous structure and nanoparticles, demonstrating high activity.

[0048] Figure 12 TEM images of a nanoscale zero-valent iron, copper, and sulfur ternary functional material prepared from natural copper ore and natural pyrite by calcining at 700°C for 2 hours in a hydrogen reducing atmosphere. (A)-(D) represent different scales. As can be seen, the nanoscale zero-valent iron, copper, and sulfur ternary functional material forms a porous structure and nanoparticles, demonstrating high activity.

[0049] Example 2

[0050] The steps of roasting natural iron-containing nano-ore to prepare nano-zero-valent mineral-based ternary functional materials are as follows:

[0051] (1) Natural phosphite, natural pyrite, natural copper ore, and natural laterite nickel-iron ore were crushed and passed through a 200-mesh sieve to obtain 0.0075 mm mineral powders.

[0052] (2) Natural pyrite powder and natural copper ore powder, natural pyrite powder and natural laterite nickel-iron ore powder, natural pyrite powder and natural phosphite powder, natural laterite nickel-iron ore powder and natural copper ore powder are mixed respectively and water is added to stir and mix evenly, and then the water is dried and hydrogen roasted and pyrolyzed to obtain nano zero-valent iron copper-sulfur mineral ternary functional materials, nano zero-valent iron nickel-sulfur mineral ternary functional materials, nano zero-valent iron phosphorus-sulfur mineral ternary functional materials, and nano zero-valent iron nickel-copper mineral ternary functional materials.

[0053] The mixture of natural pyrite powder and natural ferrophosphite powder, natural copper ore powder, or natural laterite nickel-iron ore powder, or natural laterite nickel-iron ore and natural copper ore, is in a mass ratio of 2:1. The roasting and pyrolysis process is performed at 700°C for 2 hours under a hydrogen reducing atmosphere. The amount of water added is 30% of the mass of the mixed powder.

[0054] The specific surface areas of the nanometer zero-valent iron copper sulfur mineral ternary functional material, nanometer zero-valent iron nickel sulfur mineral ternary functional material, nanometer zero-valent iron phosphorus sulfur mineral ternary functional material, and nanometer zero-valent iron nickel copper mineral ternary functional material prepared in this embodiment are: 62m 2 / g, 50m 2 / g、73m 2 / g、82m 2 / g, and the porosities are 53%, 34%, 62% and 75% respectively.

[0055] 100 mL of reaction solution was prepared: polyethylene (PE), polystyrene (PS), polycarbonate (PC), nylon (PA), polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC) (particle size approximately 1000 nm) at a concentration of 5 g / L. The nano-zero-valent mineral-based ternary functional material was added at a concentration of 1 g / L, and the concentration of sodium persulfate was 2 mmol / L. The reaction time was 8 hours. An elemental analyzer was used to monitor the O / C ratios of the samples after the catalytic reaction. Table 1 shows that the degradation rates of microplastics for the four nano-zero-valent mineral-based ternary functional materials were all above 63%. Therefore, the nano-zero-valent mineral-based ternary functional materials prepared by the present invention exhibited high catalytic efficiency.

[0056] Table 1

[0057]

[0058] Comparative Example 1

[0059] Laboratory synthesis of nano zero-valent ternary functional materials: Four groups of materials were prepared using iron salt, nickel salt, sulfur salt, copper salt and potassium dihydrogen phosphate, respectively. The mass ratio of iron salt: copper salt: sulfur salt was 2:1:1; the mass ratio of iron salt: nickel salt: sulfur salt was 2:1:1; the mass ratio of iron salt: nickel salt: copper salt was 2:1:1; the mass ratio of iron salt: sulfur salt: potassium dihydrogen phosphate was 2:1:1; by adding excess sodium borohydride for liquid phase reduction, nano zero-valent iron-copper-sulfur ternary functional materials, nano zero-valent iron-nickel-sulfur ternary functional materials, nano zero-valent iron-nickel-copper ternary functional materials, and nano zero-valent iron-sulfur-phosphorus ternary functional materials were prepared, respectively. The specific surface areas of these four ternary functional materials are: 11m 2 / g、17m 2 / g、16m 2 / g、13m 2 / g.

[0060] 100mL of reaction solution was prepared: polyethylene (PE), polystyrene (PS), polycarbonate (PC), nylon (PA), polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC) (particle size approximately 1000nm) at a concentration of 5g / L. The nano-zero-valent ternary functional material was added at a concentration of 1g / L, and the concentration of sodium persulfate was 2mmol / L. The reaction time was 8h. An elemental analyzer was used to monitor the O / C ratio of the samples after the catalytic reaction. Table 2 shows that the degradation rate of microplastics by the laboratory-synthesized nano-zero-valent ternary functional material did not exceed 61%, indicating that the laboratory-synthesized nano-zero-valent ternary functional materials using raw materials such as iron salts, potassium dihydrogen phosphate, nickel salts, sulfur salts, and copper salts have low activity.

[0061] Table 2

[0062]

[0063]

[0064] Comparative Example 2

[0065] Processing of natural iron-containing nano-minerals: crush five kinds of natural minerals, including natural phosphite powder, natural pyrite powder, natural limonite, natural copper ore powder and natural laterite nickel iron ore powder, through a 200-mesh sieve. The specific surface areas are: 14m 2 / g、18m 2 / g、22m 2 / g、24m 2 / g、12m 2 / g.

[0066] 100 mL of reaction solution was prepared: polyethylene (PE), polystyrene (PS), polycarbonate (PC), nylon (PA), polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC) (particle size approximately 1000 nm) at a concentration of 5 g / L, the amount of natural iron-containing nanomineral added was 1 g / L, the concentration of sodium persulfate was 2 mmol / L, and the reaction time was 8 hours. Using an elemental analyzer, the O / C ratio of the samples after the catalytic reaction was monitored. As shown in Table 3, the degradation rate of microplastics by natural iron-containing nanominerals does not exceed 32%, indicating that the degradation rate of natural iron-containing nanominerals for microplastics is low.

[0067] Table 3

[0068]

[0069]

[0070] Comparative Example 3

[0071] The natural phosphotyrite powder, natural pyrite powder, natural copper ore powder, natural limonite powder, and natural laterite nickel-iron ore powder that had been crushed through a 200-mesh sieve were calcined at 700°C for 2 hours in a H2 atmosphere to obtain nano-zero-valent iron-phosphorus composite materials, nano-zero-valent iron-sulfur composite materials, nano-zero-valent copper composite materials, nano-zero-valent iron composite materials, and nano-zero-valent iron-nickel composite materials. The specific surface areas of the five functional materials are: 26m 2 / g、28m 2 / g, 20m 2 / g、23m 2 / g、27m 2 / g.

[0072] 100 mL of reaction solution was prepared: polyethylene (PE), polystyrene (PS), polycarbonate (PC), nylon (PA), polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC) (particle size approximately 1000 nm) at a concentration of 5 g / L. The nano-zero-valent mineral material was added at a concentration of 1 g / L and sodium persulfate at a concentration of 2 mmol / L. The reaction was allowed to proceed for 8 hours. An elemental analyzer was used to monitor the O / C ratio of the samples after the catalytic reaction. Table 4 shows that the degradation rate of microplastics by the nano-zero-valent mineral material prepared by calcining a single mineral material did not exceed 41.6%, indicating low activity of the nano-zero-valent mineral material.

[0073] Table 4

[0074]

[0075] Comparative Example 4

[0076] The natural copper ore powder after being crushed through a 200-mesh sieve was mixed with natural limonite (mass ratio of 2:1) and calcined at 700℃ for 2h in a H2 atmosphere to obtain a nano zero-valent copper-iron composite material with a specific surface area of ​​35m 2 / g.

[0077] 100 mL of reaction solution was prepared: polyethylene (PE), polystyrene (PS), polycarbonate (PC), nylon (PA), polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC) (particle size approximately 1000 nm) at a concentration of 5 g / L. The nano-zero-valent copper-iron composite was added at a concentration of 1 g / L and a sodium persulfate concentration of 2 mmol / L. The reaction was allowed to proceed for 8 hours. An elemental analyzer was used to monitor the O / C ratio of the sample after the catalytic reaction. Table 5 shows that the nano-zero-valent copper-iron composite had a microplastic degradation rate of no more than 35.2%.

[0078] Table 5

[0079]

[0080] In summary, the nano-zero-valent mineral-based ternary functional material prepared by the present invention has rich nanopore structure and micronpore structure, and tiny nano-zero-valent nickel, copper, iron, phosphorus, and sulfur particles are evenly distributed inside the material, which can serve as active sites to form micro-primary batteries to generate hole charges, and synergistically promote the effective improvement of the catalytic oxidation activity of the nano-zero-valent mineral-based ternary functional material.

[0081] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing nano-zero-valent mineral-based ternary functional materials for catalytic degradation of microplastics by roasting natural iron-containing nano-minerals, characterized in that: Here are the steps: (1) Grind natural pyrite, natural copper ore, natural laterite nickel iron ore, and natural phosphite ore, and pass them through a 200-mesh sieve to obtain various mineral powders; (2) Natural pyrite powder and natural copper ore powder, natural pyrite powder and natural laterite nickel-iron ore powder, natural pyrite powder and natural phosphite powder, natural laterite nickel-iron ore powder and natural copper ore powder are mixed respectively and water is added to stir and mix evenly, and then the water is dried, hydrogen roasted and pyrolyzed to obtain nano zero-valent iron copper-sulfur mineral ternary functional materials, nano zero-valent iron nickel-sulfur mineral ternary functional materials, nano zero-valent iron phosphorus-sulfur mineral ternary functional materials, and nano zero-valent iron nickel-copper mineral ternary functional materials respectively; The mass ratio of the natural pyrite powder to the natural phosphotyrite powder or the natural copper ore powder or the natural laterite nickel-iron ore powder is 2-5:1; The mass ratio of the natural laterite nickel iron ore to the natural copper ore is 2-5:1; The calcination and pyrolysis process is to calcine at 500-800° C. for 1-5 hours in a hydrogen reducing atmosphere.

2. The method according to claim 1, wherein The amount of water added in step (2) is 30-50% of the mass of the mixed powder.

3. Application of the nano zero-valent mineral-based ternary functional material prepared by the method according to claim 1 or 2 in catalytic degradation of microplastics, characterized in that: Nano-zero-valent mineral-based ternary functional materials are used as catalysts to form a heterogeneous advanced oxidation system with persulfate, catalyzing persulfate to produce highly oxidizing free radicals, which can efficiently and quickly degrade microplastics.

4. The use according to claim 3, characterized in that Nano-zero-valent mineral-based ternary functional materials and persulfate are directly added to wastewater containing microplastics to catalyze the persulfate oxidation and degradation of microplastics in the wastewater; in the degradation system formed, the concentration of nano-zero-valent mineral-based ternary functional materials is 0.05-10g / L, the concentration of persulfate is 0.1-5mmol / L, the concentration of microplastics is 0.1-10g / L, and the degradation treatment time is 0.1-10h.

5. The use according to claim 3 or 4, characterized in that The persulfate is selected from peroxymonosulfate or peroxydisulfate.

6. The use according to claim 3 or 4, characterized in that The microplastic material for catalytic degradation is one or more of polystyrene, polyethylene, nylon, polycarbonate, polypropylene, polyethylene terephthalate and polyvinyl chloride.

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