Preparation method of ball-milled carbon-based iron sulfide composite material and application thereof
Carbon-based iron sulfide composite materials were prepared by ball milling, and zero-valent iron was modified with nitrogen-doped biochar. This solved the problems of spontaneous oxidation and insufficient reaction of hydrophobic pollutants in the treatment of water pollutants by zero-valent iron catalysts, and achieved a high efficiency in pollutant removal.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTH CHINA AGRICULTURAL UNIVERSITY
- Filing Date
- 2023-07-03
- Publication Date
- 2026-06-05
AI Technical Summary
Existing zero-valent iron catalysts suffer from spontaneous oxidation, reduced activity, and insufficient reaction with hydrophobic pollutants in water pollution treatment. Modified materials still lack specificity and efficiency.
Carbon-based iron sulfide composite materials were prepared by ball milling. Zero-valent iron was modified with nitrogen-doped biochar to form a hydrophobic structure and active sites, which inhibited the reaction between zero-valent iron and water and improved the removal rate of hydrophobic organic pollutants.
It significantly improved the removal rate of halogenated hydrocarbons, organic pesticides and antibiotics, achieving efficient and specific pollutant degradation.
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Figure CN116986667B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of water pollution remediation technology, and in particular relates to a method for preparing a ball-milled carbon-based iron sulfide composite material and its application. Background Technology
[0002] Water pollution causes global environmental and food security problems. The discharge of factory wastewater containing organic pollutants (such as chlorinated solvents) and the use of persistent organic pollutants in medicine and agriculture (such as pesticides and antibiotics) severely restrict water resource utilization and water environment safety, and greatly endanger the ecological environment and human health.
[0003] Zero-valent iron (ZVFe) catalysts have been widely used for the reduction and removal of various water pollutants due to their strong reducing properties, low cost, and environmental friendliness. However, ZVFe also has several drawbacks in practical applications. Firstly, it can spontaneously aggregate and oxidize in the air to form a dense iron oxide layer, leading to reduced activity and inefficient utilization. Secondly, the hydrophilic nature of ZVFe results in non-specificity against hydrophobic organic pollutants in the source region, causing hydrogen evolution reactions with water and hindering effective removal of pollutants. To overcome these inherent limitations, researchers both domestically and internationally have conducted extensive work on ZVFe modification methods. However, modified ZVFe still lacks specificity for hydrophobic pollutants or exhibits certain aggregation and passivation defects, preventing the maximization and efficient utilization of the modified material. Therefore, it remains necessary to explore suitable modification methods to address these technical problems. Summary of the Invention
[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for preparing ball-milled iron sulfide-based composite materials. The ball-milled carbon-based iron sulfide composite material obtained by this invention not only has a simple and low-cost synthesis method, but also exhibits newly formed reactive sites and hydrophobic structures on its surface that interact with pollutants. This significantly inhibits the reaction between zero-valent iron materials and water, and also demonstrates a high removal rate for hydrophobic organic pollutants containing chlorine or nitro groups, such as halogenated hydrocarbons, organic pesticides, and antibiotics.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A method for preparing a ball-milled carbon-based iron sulfide composite material includes the following steps:
[0007] S1: Grind waste biomass into powder and mix it thoroughly with nitrogen source precursor compounds of equal mass. Add the mixture to a container containing deionized water and then place the container on a shaker to vibrate. After vibrating for 2-8 hours, dry the mixture and place it in a pyrolysis furnace. Increase the temperature gradually to 800-1000℃ at a rate of 3-6℃ / min and pyrolyze for 0.1-2 hours. Finally, cool the mixture to remove the black solid and obtain nitrogen-doped biochar.
[0008] S2: Mix micron-sized zero-valent iron powder and sulfur powder and add them to a planetary ball mill. Ball mill for 1-30 hours, and clean to obtain ball-milled zero-valent iron sulfide.
[0009] S3: Nitrogen-doped biochar and ball-milled zero-valent iron powder prepared by S1 and S2 are added to a planetary ball mill containing a certain mass of grinding media. A small amount of nitrogen is introduced before operation and the mill is sealed. The planetary ball mill is run for 1-30 hours to obtain a ball-milled carbon-based iron sulfide composite material.
[0010] Preferably, as a preferred embodiment, the oscillation time in S1 is preferably 6 hours, the gradient heating rate is preferably 5°C / min, the gradient heating temperature is preferably 900°C, and the pyrolysis time is preferably 0.5 hours.
[0011] Preferably, as a preferred embodiment, the ball milling time in S2 is preferably 10 hours.
[0012] Preferably, as a preferred embodiment, the waste biomass in step S1 includes, but is not limited to, straw.
[0013] Preferably, as a preferred embodiment, the nitrogen source precursor compound is urea or melamine.
[0014] Preferably, as a preferred embodiment, the sulfur content in the ball milling and sulfidation of zero-valent iron in step S2 is 5-15%, preferably 10%.
[0015] Preferably, as a preferred embodiment, the particle size of the ball-milled zero-valent iron in step S3 is 40-400 μm. The particle size of the ball-milled zero-valent iron affects the material's performance in removing target pollutants. If the ball-milled zero-valent iron particles are too large, there are fewer contact sites with the pollutants, resulting in lower activity; if the ball-milled zero-valent iron particles are too small, the reactivity is too high, leading to a violent reaction between the zero-valent iron and the aqueous solution, resulting in the loss of the ball-milled zero-valent iron. The preferred particle size of the ball-milled zero-valent iron is 100-200 μm.
[0016] Preferably, as a preferred embodiment, the mass ratio of nitrogen-doped biochar to iron sulfide is 2%-20%, more preferably 5-15%.
[0017] Preferably, as a preferred embodiment, the ball milling time is 10-20 hours.
[0018] Preferably, as a preferred embodiment, the grinding media is zirconia beads, steel beads, agate beads, or silicon nitride beads with a diameter of 1-10 mm. More preferably, the grinding media is zirconia beads.
[0019] Preferably, as a preferred embodiment, the preparation method of the present invention includes the following steps: 30g of nitrogen-doped biochar and 10% by mass of iron sulfide powder are mixed and placed in a ball mill jar filled with nitrogen gas. The ball milling speed is 300 rpm, and the mixture is ground for 10 hours. After grinding, the grinding media and product are separated under a nitrogen atmosphere to obtain the ball-milled carbon-based iron sulfide composite material. The nitrogen-doped biochar is obtained by impregnation and pyrolysis of a mixture of biochar and urea. The iron sulfide powder is obtained by ball milling micron-sized zero-valent iron and sulfur powder. The particle size of the ball-milled zero-valent iron sulfide powder is 100-200 μm. The grinding media are zirconium oxide beads with a diameter of 1-10 mm.
[0020] Another objective of this invention is to provide a carbon-based iron sulfide composite material prepared by the aforementioned method. Experiments have shown that the ball-milled carbon-based iron sulfide composite material is a composite material obtained by modifying the surface of ball-milled zero-valent iron sulfide with nitrogen-doped biochar. On the one hand, nitrogen-doped biochar is a strongly hydrophobic porous carbon-based compound with strong dispersibility, reducing the aggregation of ball-milled zero-valent iron sulfide. On the other hand, during the ball milling process, new active sites are formed between the ball-milled zero-valent iron sulfide and the nitrogen-doped biochar, improving the passivation defects on the zero-valent iron surface while enhancing the material's activity and adsorption specificity for target pollutants.
[0021] Another objective of this invention is to provide an application of the aforementioned carbon-based iron sulfide composite material, which exhibits effective removal of organic pollutants such as halogenated hydrocarbons, organic pesticides, and antibiotics from water bodies. This material is suitable for wastewater treatment and groundwater remediation in industrial and agricultural fields. Specifically, the ball-milled carbon-based iron sulfide composite material is added to an organic pollutant solution at a concentration of 1 g / L. The concentration of the organic pollutants is 10 mg / L, the reaction temperature is 30°C, and the reaction pH is 6-8. The pollutants include trichloroethylene, imidacloprid, acetochlor, dicamba, chloramphenicol, and tetracycline. The reduction and removal of pollutants are achieved through mechanical stirring or rotary oscillation.
[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0023] (1) This invention utilizes the high-energy ball milling process to continuously collide and squeeze the ball milling media and the ball milling material, thereby forming new physicochemical or mechanical properties between the ball milled sulfided zero-valent iron and nitrogen-doped biochar. While improving the passivation defects on the surface of zero-valent iron, it introduces active sites such as pyridine nitrogen, graphitic nitrogen, and iron nitride, thereby improving the activity of zero-valent iron and the adsorption selectivity for target pollutants.
[0024] (2) The method of this invention involves mixing nitrogen-doped biochar and ball-milled iron sulfide powder, followed by ball milling. The resulting ball-milled carbon-based iron sulfide composite material can be used to remove hydrophobic organic pollutants such as halogenated hydrocarbons, pesticides, and antibiotics, and exhibits high removal and degradation efficiency. Compared to ball-milled zero-valent iron sulfide materials, the ball-milled carbon-based iron sulfide composite material obtained by this invention has higher versatility. Attached Figure Description
[0025] Figure 1 Scanning electron microscope (SEM) images of ball-milled zero-valent iron in Comparative Example 1 (A) and ball-milled carbon-based iron sulfide composite material in Example 1 (B) are shown.
[0026] Figure 2 The selected electron diffraction pattern of the ball-milled carbon-based iron sulfide composite material in Example 1 is shown;
[0027] Figure 3 Transmission electron microscopy (TEM) images of the ball-milled carbon-based iron sulfide composite material in Example 1 are shown.
[0028] Figure 4 The X-ray electron spectrum and Fourier transform infrared spectrum of the N1s orbital of the ball-milled carbon-based iron sulfide composite material in Example 1 and the ball-milled zero-valent iron sulfide material in Comparative Example 1 are shown.
[0029] Figure 5 The contact angles of ball-milled nitrogen-doped biochar in Comparative Example 2 (A), ball-milled zero-valent iron in Comparative Example 1 (B), and ball-milled carbon-based iron sulfide composite material in Example 1 (C) are shown in schematic diagrams. Detailed Implementation
[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The specific embodiments described below further illustrate the present invention.
[0031] Unless otherwise specified, all chemical substances of this invention are commercially available.
[0032] I. Example 1
[0033] A method for preparing a ball-milled carbon-based iron sulfide composite material includes the following steps:
[0034] Rice straw powder and urea (mass ratio 1:1) were weighed into a beaker, and 10 times the amount of water was added and mixed thoroughly. The mixture was then transferred to a sealed bag and placed in a shaker at 300 rpm for 6 hours. After drying, the mixture was placed in a muffle furnace and pyrolyzed at 900°C at a rate of 5°C / min under a nitrogen atmosphere for 0.5 hours. After natural cooling, nitrogen-doped biochar was obtained. Simultaneously, 30 g of sulfur powder (mass ratio 10%) and micron-sized zero-valent iron were placed in a ball mill at 300 rpm with 1-10 mm zirconia beads as the grinding media for 10 hours to obtain ball-milled sulfided zero-valent iron. Finally, 30g of nitrogen-doped biochar and 10% of iron sulfide powder were added to a 500mL ball mill jar. 50g of zirconia beads with a diameter range of 1-10mm were weighed and added to the ball mill jar. Nitrogen gas was introduced into the jar, and after sealing, the ball mill program was adjusted to a speed of 300rpm. The ball mill was then milled for 10 hours to obtain the ball-milled carbon-based iron sulfide composite material.
[0035] II. Example 2
[0036] A method for preparing a ball-milled carbon-based iron sulfide composite material includes the following steps:
[0037] Rice straw powder and urea (mass ratio 1:1) were weighed into a beaker, and 10 times the amount of water was added and mixed thoroughly. The mixture was then transferred to a sealed bag and placed in a shaker at 300 rpm for 6 hours. After drying, the mixture was placed in a muffle furnace and pyrolyzed at 900°C at a rate of 5°C / min under a nitrogen atmosphere for 0.5 hours. After natural cooling, nitrogen-doped biochar was obtained. Simultaneously, 30 g of sulfur powder (mass ratio 10%) and micron-sized zero-valent iron were placed in a ball mill at 300 rpm with 1-10 mm zirconia beads as the grinding media for 10 hours to obtain ball-milled sulfided zero-valent iron. Finally, 30g of nitrogen-doped biochar and 5% of iron sulfide powder were added to a 500mL ball mill jar. 50g of zirconia beads with a diameter range of 1-10mm were weighed and added to the ball mill jar. Nitrogen gas was introduced into the jar, and after sealing, the ball mill program was adjusted to a speed of 300rpm. The ball mill was then milled for 10 hours to obtain the ball-milled carbon-based iron sulfide composite material.
[0038] III. Example 3
[0039] A method for preparing a ball-milled carbon-based iron sulfide composite material includes the following steps:
[0040] Rice straw powder and urea (mass ratio 1:1) were weighed into a beaker, and 10 times the amount of water was added and mixed thoroughly. The mixture was then transferred to a sealed bag and placed in a shaker at 300 rpm for 6 hours. After drying, the mixture was placed in a muffle furnace and pyrolyzed at 900°C at a rate of 5°C / min under a nitrogen atmosphere for 0.5 hours. After natural cooling, nitrogen-doped biochar was obtained. Simultaneously, 30 g of sulfur powder (mass ratio 10%) and micron-sized zero-valent iron were placed in a ball mill at 300 rpm with 1-10 mm zirconia beads as the grinding media for 10 hours to obtain ball-milled sulfided zero-valent iron. Finally, 30g of nitrogen-doped biochar and 15% of iron sulfide powder were added to a 500mL ball mill jar. 50g of zirconia beads with a diameter range of 1-10mm were weighed and added to the ball mill jar. Nitrogen gas was introduced into the jar, and after sealing, the ball mill program was adjusted to a speed of 300rpm. The ball mill was then milled for 10h to obtain the ball-milled carbon-based iron sulfide composite material.
[0041] IV. Example 4
[0042] A method for preparing a ball-milled carbon-based iron sulfide composite material includes the following steps:
[0043] Rice straw powder and urea (mass ratio 1:1) were weighed into a beaker, and 10 times the amount of water was added and mixed thoroughly. The mixture was then transferred to a sealed bag and placed in a shaker at 300 rpm for 6 hours. After drying, the mixture was placed in a muffle furnace and pyrolyzed at 900°C at a rate of 5°C / min under a nitrogen atmosphere for 0.5 hours. After natural cooling, nitrogen-doped biochar was obtained. Simultaneously, 30 g of sulfur powder (mass ratio 10%) and micron-sized zero-valent iron were placed in a ball mill at 300 rpm with 1-10 mm zirconia beads as the grinding media for 10 hours to obtain ball-milled sulfided zero-valent iron. Finally, 30g of nitrogen-doped biochar and 10% of iron sulfide powder were added to a 500mL ball mill jar. 100g of zirconia beads with a diameter range of 1-10mm were weighed and added to the ball mill jar. Nitrogen gas was introduced into the jar, and after sealing, the ball mill program was adjusted to a speed of 300rpm. The ball mill was then milled for 10h to obtain the ball-milled carbon-based iron sulfide composite material.
[0044] V. Example 5
[0045] A method for preparing a ball-milled carbon-based iron sulfide composite material includes the following steps:
[0046] Rice straw powder and urea (mass ratio 1:1) were weighed into a beaker, and 10 times the amount of water was added and mixed thoroughly. The mixture was then transferred to a sealed bag and placed in a shaker at 300 rpm for 6 hours. After drying, the mixture was placed in a muffle furnace and pyrolyzed at 900°C at a rate of 5°C / min under a nitrogen atmosphere for 0.5 hours. After natural cooling, nitrogen-doped biochar was obtained. Simultaneously, 30 g of sulfur powder (mass ratio 10%) and micron-sized zero-valent iron were placed in a ball mill at 300 rpm with 1-10 mm zirconia beads as the grinding media for 10 hours to obtain ball-milled sulfided zero-valent iron. Finally, 30g of nitrogen-doped biochar and 10% of iron sulfide powder were added to a 500mL ball mill jar. 50g of zirconia beads with a diameter range of 1-10mm were weighed and added to the ball mill jar. Nitrogen gas was introduced into the jar, and after sealing, the ball mill program was adjusted to a speed of 300rpm. The ball mill was then milled for 20h to obtain the ball-milled carbon-based iron sulfide composite material.
[0047] VI. Comparative Example 1
[0048] A method for preparing a ball-milled sulfurized zero-valent iron composite material includes the following steps:
[0049] Sulfur powder and micron-sized zero-valent iron (30g total mass, 10% by mass) were placed in a ball mill. The ball mill speed was 300 rpm, the grinding media were 1-10 mm zirconia beads, and the time was 10 h to obtain ball-milled zero-valent iron.
[0050] VII. Comparative Example 2
[0051] A method for preparing a ball-milled nitrogen-doped biochar composite material includes the following steps:
[0052] A certain mass of rice straw powder was weighed into a muffle furnace and pyrolyzed to 900℃ at a rate of 5℃ / min under a nitrogen atmosphere. The temperature was maintained at 900℃ for 0.5 h, and after natural cooling, nitrogen-doped biochar was obtained. Next, 30 g of nitrogen-doped biochar was added to a 500 mL ball mill jar. 50 g of zirconia beads with a diameter range of 1-10 mm were weighed and added to the jar. Nitrogen gas was introduced into the jar, and after sealing, the ball mill program was adjusted to 300 rpm, and ball milling was performed for 10 h to obtain ball-milled nitrogen-doped biochar.
[0053] 8. Comparative Example 3
[0054] A method for preparing a mixed material of ball-milled nitrogen-doped biochar and ball-milled zero-valent iron sulfide includes the following steps:
[0055] A certain mass of rice straw powder was weighed into a muffle furnace and pyrolyzed to 900℃ at a rate of 5℃ / min under a nitrogen atmosphere. The temperature was maintained at 900℃ for 0.5 hours, and after natural cooling, nitrogen-doped biochar was obtained. Next, 30g of nitrogen-doped biochar was added to a 500mL ball mill jar. 50g of 1-10mm diameter zirconia beads were weighed into the jar, nitrogen was introduced, and the jar was sealed. The ball mill was then set to 300rpm and milled for 10 hours to obtain ball-milled nitrogen-doped biochar. Simultaneously, 30g of sulfur powder (10% by mass) and micron-sized zero-valent iron were placed in a ball mill at 300rpm with 1-10mm zirconia beads as the grinding media for 10 hours to obtain ball-milled zero-valent iron sulfide. Finally, the obtained ball-milled nitrogen-doped biochar and ball-milled sulfided zero-valent iron were placed in a beaker at a mass ratio of 10% and physically mixed to obtain a mixed material of ball-milled nitrogen-doped biochar and ball-milled sulfided zero-valent iron.
[0056] IX. Application Example 1
[0057] Removal of chlorinated solvent pollutants: 40 mL of a 10 mg / L trichloroethylene solution (pH 6.8) was added to a 40 mL sample bottle. Different materials were added (40 mg each) and mixed using a shaking and stirring motion at 150 rpm in a 30℃ environment. The residual concentration of trichloroethylene in the system was measured at regular intervals. The experimental results are shown in Table 1. During the reaction, the removal rate of ball-milled modified zero-valent iron sulfide was significantly higher than that of ball-milled zero-valent iron sulfide, with the optimal ratio achieving a removal rate of 95.9% within 180 min. It was also found that simply adding ball-milled zero-valent iron sulfide and nitrogen-doped biochar to the pollutant mixture did not significantly improve the degradation effect on trichloroethylene, indicating that the performance of the ball-milled modified composite material is completely different from that obtained by physically mixing the two materials. Therefore, ball-milled modified zero-valent iron sulfide with nitrogen-doped biochar can greatly improve the removal efficiency of the composite material for trichloroethylene.
[0058] Table 1. Removal rate of trichloroethylene by ball-milled carbon-based iron sulfide composite material within 180 min.
[0059] Composite materials Trichloroethylene removal rate Example 1 95.9％ Example 2 78.6％ Example 3 86.2％ Example 4 88.9％ Example 5 91.3％ Comparative Example 1 19.3％ Comparative Example 2 20.6％ Comparative Example 3 33.7％
[0060] 10. Application Example 2
[0061] Removal of pesticide pollutants: 40 mL of a 10 mg / L solution of imidacloprid, acetochlor, and dicamba was added to a 40 mL sample bottle. The solution pH was 6.5-7.5. 40 mg of each material was added, and the mixture was stirred at 150 rpm in a 30℃ environment. The experimental results are shown in Table 2. The ball-milled carbon-based iron sulfide composite material achieved a minimum removal rate of 86.7% for imidacloprid, chlorothalonil, and dicamba within 180 min, while the unmodified ball-milled zero-valent iron sulfide showed a maximum removal rate of less than 35.6% within 180 min. This indicates that the addition of nitrogen-doped biochar during ball milling can effectively promote the removal of hydrophobic pesticides such as imidacloprid, acetochlor, and dicamba by zero-valent iron sulfide.
[0062] Table 2. Removal rates of several pesticides by ball-milled carbon-based iron sulfide composite material within 180 min.
[0063]
[0064] XI. Application Example 3
[0065] Removal of antibiotic contaminants: 40 mL of a 10 mg / L chloramphenicol and tetracycline solution was added to a 40 mL sample bottle. The solution pH was 6.0-7.0. 40 mg of different materials were added, and the mixture was stirred at 150 rpm in a 30℃ environment. The experimental results are shown in Table 3. The ball-milled carbon-based iron sulfide composite material achieved removal rates of over 90% for both chloramphenicol and tetracycline within 180 min, significantly higher than unmodified ball-milled zero-valent iron sulfide and its mixture with nitrogen-doped biochar. In summary, the carbonization of zero-valent iron sulfide by nitrogen-doped biochar enhanced its removal capacity for both chloramphenicol and tetracycline.
[0066] Table 3. Removal rate of antibiotic contaminants by ball-milled carbon-based iron sulfide composite material within 180 min.
[0067]
[0068] Figure 1 The scanning electron microscope (SEM) images of the prepared ball-milled carbon-based iron sulfide composite material were compared with those obtained by... Figure 1 A and Figure 1 B shows that the ball-milled carbon-based iron sulfide composite material is blocky and flake-like compared to the ball-milled zero-valent iron sulfide, and the surface is rougher; and due to the presence of nitrogen-doped biochar, the particle size of the ball-milled carbon-based iron sulfide composite material is further reduced to submicron particles (100-1000nm).
[0069] Figure 2 The electron diffraction pattern of the ball-milled carbon-based iron sulfide composite material in Example 1 is shown below. Figure 1 and Figure 2It can also be found that the elements of the carbon-based iron sulfide composite material are evenly dispersed after ball milling, which to some extent overcomes the defect of easy agglomeration of traditional zero-valent iron.
[0070] Figure 3 The image shown is a transmission electron microscope (TEM) image of the ball-milled carbon-based iron sulfide composite material in Example 1. By observing a single particle with TEM, it can be seen that grains are superimposed on the surface and a new graphite carbon layer appears, further demonstrating the successful synthesis of the ball-milled carbon-based iron sulfide composite material.
[0071] Figure 4 The X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectra of the N1s orbitals of the ball-milled carbon-based iron sulfide composite material and the ball-milled zero-valent iron sulfide material prepared in Example 1 are shown. In the XPS, 398.18, 399.48, and 400.58 eV represent the active sites of graphitic nitrogen, pyrrole nitrogen, and graphitic nitrogen, respectively. The FTIR spectra at 1794 cm⁻¹ are also shown. -1 The new peak position of Fe-N X The heteroatom peaks indicate that the nitrogen-doped biochar and zero-valent iron mixture has introduced some active sites that are conducive to the reaction through continuous breaking and splicing.
[0072] Figure 5 This is a schematic diagram of the contact angles of the nitrogen-doped biochar, ball-milled zero-valent iron sulfide, and ball-milled carbon-based iron sulfide composite material prepared in Example 1. It can be observed that the nitrogen-doped biochar exhibits superhydrophobicity, and that modifying zero-valent iron sulfide with nitrogen-doped biochar improves the hydrophobicity of the iron sulfide surface, giving it amphiphilic properties and specificity for hydrophobic organic pollutants.
[0073] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.
Claims
1. A method for preparing a ball-milled carbon-based iron sulfide composite material, characterized in that, Includes the following steps: S1: Grind waste biomass into powder and mix it thoroughly with nitrogen source precursor compounds of equal mass. Add the mixture to a container containing deionized water and then place the container on a shaker to vibrate. After vibrating for 2-8 hours, dry the mixture and place it in a pyrolysis furnace. Increase the temperature gradually to 800-1000℃ at a rate of 3-6℃ / min and pyrolyze for 0.1-2 hours. Finally, cool the mixture to remove the black solid and obtain nitrogen-doped biochar. S2: Mix micron-sized zero-valent iron powder and sulfur powder and add them to a planetary ball mill. Ball mill for 1-30 hours, and clean to obtain ball-milled zero-valent iron sulfide. S3: Nitrogen-doped biochar and milled sulfided zero-valent iron powder prepared by S1 and S2 are added to a planetary ball mill containing a certain mass of grinding media. A small amount of nitrogen is introduced before operation and the mill is sealed. The planetary ball mill is run for 1-30 hours to obtain a milled carbon-based sulfided iron composite material. In S3, the particle size of the ball-milled zero-valent iron sulfide is 40-400 μm; the mass ratio of nitrogen-doped biochar to iron sulfide is 2%-20%.
2. The method for preparing a ball-milled carbon-based iron sulfide composite material according to claim 1, characterized in that, The process includes the following steps: the oscillation time in S1 is 6 h, the gradient heating rate is 5℃ / min, the gradient heating temperature is 900℃, and the pyrolysis time is 0.5 h.
3. The method for preparing a ball-milled carbon-based iron sulfide composite material according to claim 1, characterized in that, The ball milling time in S2 is 10 h, and the sulfur content in the ball-milled zero-valent iron is 5-15%.
4. The ball-milled carbon-based iron sulfide composite material prepared by the preparation method according to any one of claims 1-3.
5. The application of the ball-milled carbon-based iron sulfide composite material according to claim 4, characterized in that, The ball-milled carbon-based iron sulfide composite material is used for the removal of halogenated hydrocarbons, organic pesticides, and antibiotics.
6. The application according to claim 5, characterized in that, The pollutants include trichloroethylene, imidacloprid, acetochlor, dicamba, chloramphenicol, and tetracycline.