A carbon material supported complex nano zero-valent iron, its preparation method and application

Abstract

The present invention discloses a carbon material supported complexed nano zero-valent iron, its preparation method and application, belonging to the technical field of heavy metal pollution remediation. The preparation method of the carbon material supported complexed nano zero-valent iron disclosed by the present invention uses a hydroxy- or amino-containing compound to complex divalent iron ions, and at the same time mixes with carbon nanotubes and biochar prepared from agricultural wastes (including corn straw, rice husk and reed) to obtain a mixed solution, and adds a potassium borohydride solution to the mixed solution to obtain a heavy metal ion remover of the carbon material supported complexed nano zero-valent iron. The preparation method is simple and low in cost, and the obtained carbon material supported complexed nano zero-valent iron has higher adsorption capacity and reaction capacity for heavy metal ions, and has broad application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of heavy metal pollution remediation, and particularly relates to a carbon material-supported complexed nano zero-valent iron, a preparation method thereof, and an application thereof. Background Art

[0002] With the rapid economic development and the acceleration of the industrialization process, a large amount of heavy metal ions generated from industries such as mining, petrochemical, ceramics, electroplating, and papermaking are discharged into the natural environment. The heavy metal ions discharged into water bodies are difficult to degrade in the natural environment, are easily absorbed by aquatic organisms, and pose a hazard to humans along with the transfer of the food chain. They also have a toxic effect on various organs of the human body. Among various heavy metal ions, cadmium (Cd), antimony (Sb), and chromium (Cr) have become the main concerned elements of heavy metal pollution problems due to their large toxic effects and wide pollution ranges. Among them, cadmium is one of the 5 heaviest metal elements with the strongest toxicity, mainly derived from lead-zinc mines, non-ferrous metal smelting, electroplating, and factories using cadmium compounds as raw materials or catalysts. It has a relatively high toxicity to humans and is also easily migratory in water bodies, ultimately causing a potential risk of human cadmium exposure. Antimony is a common associated ore metal in metallurgy and mining, with characteristics such as high toxicity, persistence, and irreversibility. Chromium exists in two valence states, trivalent and hexavalent, in water bodies, and hexavalent chromium is a strong carcinogen. Therefore, how to efficiently remove it is an issue that must be considered in reducing heavy metal pollution.

[0003] There are various methods for remediating heavy metal pollution, including: electrochemistry method, chemical reduction method, ion exchange method, chemical precipitation method, adsorption method, biological method, photocatalysis method, etc. Among them, the nano zero-valent iron reduction remediation technology belongs to the category of chemical reduction method and is a highly promising technology for remediating heavy metal pollution. Nano zero-valent iron has characteristics such as active chemical properties, small particle size, rapid reaction, and large specific surface area. It is easily oxidized itself, so it can transfer electrons to heavy metal ions in the contaminated target, enabling the heavy metal ions to gain electrons and be reduced, thereby achieving the purpose of reducing heavy metal pollution.

[0004] Currently, researchers have developed various nano zero-valent iron-based products. For example, nano zero-valent iron is supported by yeast to utilize the adsorption performance of yeast to improve the treatment efficiency of nano zero-valent iron; nano zero-valent iron is modified to enhance its stability and the ability to remove heavy metals; and nano zero-valent iron is coated with sodium alginate to reduce the cost of nano zero-valent iron and its impact on the environment. However, these products only improve the ability to treat heavy metals on the basis of the original nano zero-valent iron, and the removal rate of heavy metals has not been significantly improved. In practical applications, these products require half an hour or even longer to reach the best treatment effect. The excessively long treatment time will increase the construction and operation costs of actual treatment facilities. Therefore, there is an urgent need to develop nano zero-valent iron products with the ability to rapidly treat heavy metals. Summary of the Invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a carbon material-supported complex nano-zero-valent iron and its preparation method and application, so as to solve the technical problems such as the long time for treating metals by the existing nano-zero-valent iron.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The present invention discloses a preparation method of a carbon material-supported complex nano-zero-valent iron, comprising the following steps:

[0008] S1: Add the doped and mixed carbon material, ferrous sulfide and the compound containing hydroxyl or amino group into water, and stir to obtain a mixed solution;

[0009] S2: Drop the potassium borohydride solution into the mixed solution for reaction, then perform solid-liquid separation to obtain a reactant, and after washing and drying the reactant, a carbon material-supported complex nano-zero-valent iron is obtained.

[0010] Further, in S1, the doped and mixed carbon material is prepared by mixing carbon nanotubes and biochar; the biochar is prepared from agricultural waste.

[0011] Further, the agricultural waste includes corn straw, rice husk or reed; the carbon nanotubes are multi-walled carbon nanotubes.

[0012] Further, in S1, the compound containing hydroxyl or amino group is aminomethanetripropionic acid or 3-aminopropanesulfonic acid; the stirring time is 10 min to 15 min.

[0013] Further, in S1, when the compound containing hydroxyl or amino group is aminomethanetripropionic acid, the dosage ratio of the carbon nanotubes, biochar, ferrous sulfide, the compound containing hydroxyl or amino group and water is (1 - 1.5) g : (1.5 - 2.0) g : (3.5 - 4.0) g : (3.9 - 4.8) mL : (300 - 400) mL.

[0014] Further, in S1, when the compound containing hydroxyl or amino group is 3-aminopropanesulfonic acid, the dosage ratio of the carbon nanotubes, biochar, ferrous sulfide, the compound containing hydroxyl or amino group and water is (1 - 1.3) g : (3.0 - 4.0) g : (2.1 - 3.3) g : (5.0 - 6.0) mL : (300 - 400) mL.

[0015] Further, in S2, the potassium borohydride solution is obtained by mixing potassium borohydride and water, and the dosage ratio of potassium borohydride and water is (3.5 - 4.5) g : (70 - 100) mL.

[0016] Furthermore, in S2, the dosage ratio of the potassium borohydride solution to the mixed solution is (70 - 100) mL : (300 - 400) mL; the reaction time is 15 min - 25 min; the drying is vacuum freeze-drying, and the drying temperature is -50°C to -40°C.

[0017] The present invention also discloses a carbon material supported complex nano zero-valent iron prepared by the above preparation method.

[0018] The present invention also discloses the application of the above carbon material supported complex nano zero-valent iron. The carbon material supported complex nano zero-valent iron is used as a heavy metal remover in wastewater containing Cd(II) at a concentration of 1 - 50 mg / L, wastewater containing Sb(V) at a concentration of 1 - 50 mg / L, and wastewater containing Cr(VI) at a concentration of 1 - 100 mg / L.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention discloses a preparation method of a carbon material supported complex nano zero-valent iron. A hydroxyl- or amino-containing compound is used to complex divalent iron ions, and at the same time, it is mixed with biochar prepared from carbon nanotubes and agricultural wastes (including corn straw, rice husk, and reed) to obtain a mixed solution. Then, a potassium borohydride solution is added to the mixed solution to obtain a carbon material supported complex nano zero-valent iron heavy metal ion remover. The carbon nanotubes used in the present invention have a large specific surface area, extremely high chemical stability, unique electronic structure, nano-sized hollow cavities, and excellent adsorption properties. It can make the nano zero-valent iron particles better dispersed and stable, and generate higher adsorption capacity and heavy metal ion reaction capacity. It can also form a microelectrode structure with nano zero-valent iron, effectively preventing the formation of an oxide film on the surface of nano zero-valent iron, making the reaction activity of the carbon material supported complex nano zero-valent iron much better than that of ordinary nano zero-valent iron. At the same time, the agricultural wastes used in the present invention are widely sourced and low in cost. The addition of the biochar prepared from them greatly reduces the preparation cost of the material, while retaining the ability of the material to remove heavy metals, giving the carbon material supported complex nano zero-valent iron material a broader application prospect in treating water pollution.

[0021] Furthermore, the present invention selects a hydroxyl- or amino-containing compound, which has a strong complexing effect on divalent iron ions. Then, through a reducing agent, potassium borohydride solution, carbon material supported complex nano zero-valent iron is obtained. Compared with the carbon material supported nano zero-valent iron material prepared without adding a hydroxyl- or amino-containing compound, the obtained complex zero-valent iron is amorphous zero-valent iron.

[0022] The present invention also discloses a carbon material supported complexed nano zero-valent iron prepared by the above preparation method. Compared with crystalline zero-valent iron, the amorphous zero-valent iron has a longer Fe-Fe bond and is more prone to breakage, so it has higher energy and is in an unstable state. Therefore, the carbon material supported complexed nano zero-valent iron has a more efficient treatment ability and a faster removal rate compared with ordinary nano zero-valent iron, and also has a more ideal removal effect on heavy metal ions in water bodies.

[0023] The present invention also discloses the application of the above carbon material supported complexed nano zero-valent iron. The heavy metal remover in water prepared by the present invention can be used for the removal and purification of heavy metal ions in water bodies, with a fast removal rate and good removal effect. According to relevant experimental results, the removal of all heavy metals by the material in water can be completed within 2 minutes, and the removal rates of the material for simulated Cd(II) wastewater and Sb(V) wastewater with an initial concentration of 30 mg / L can reach 100%, and the removal rate of the material for simulated Cr(VI) wastewater with an initial concentration of 60 mg / L can also reach 100%. When the initial concentrations of the simulated Cd(II) wastewater and Sb(V) wastewater are increased to 40 mg / L, the removal rates of the material for them within 2 minutes are 98.9% and 97.8% respectively, and the removal rate of the material for 80 mg / L simulated Cr(VI) wastewater is still 100%. Even for the simulated Cd(II) and Sb(V) wastewater with an initial concentration of 50 mg / L, the removal rates of the material for them within 2 minutes are 97.3% and 96.9% respectively, and the removal rate of the material for 100 mg / L simulated Cr(VI) wastewater is 98.7%. Moreover, the removal rate of this material is significantly better than that of the carbon material supported nano zero-valent iron material. Description of the Drawings

[0024] Figure 1 Photographs of the carbon material supported complexed nano zero-valent iron materials prepared in Examples 1-6;

[0025] Wherein: a - carbon material supported complexed nano zero-valent iron formed by adding aminomethanetrisphosphonic acid; b - carbon material supported complexed nano zero-valent iron formed by adding 3-aminopropanesulfonic acid;

[0026] Figure 2 Scanning electron microscope (SEM) images of the carbon material supported complexed nano zero-valent iron materials prepared in Examples 1-6;

[0027] Wherein: a - carbon material supported complexed nano zero-valent iron formed by adding aminomethanetrisphosphonic acid; b - carbon material supported complexed nano zero-valent iron formed by adding 3-aminopropanesulfonic acid;

[0028] Figure 3 X-ray powder diffraction (XRD) patterns of the carbon material supported complexed nano zero-valent iron materials prepared in Examples 1-6;

[0029] Wherein: a - carbon material supported complex nano zero-valent iron formed by adding aminomethanetricarboxylic acid; b - carbon material supported complex nano zero-valent iron formed by adding 3-aminopropanesulfonic acid;

[0030] Figure 4 It is a comparison chart of the removal effects of different carbon material supported nano zero-valent iron on metal wastewater;

[0031] Wherein: a - heavy metal Cd(II) wastewater; b - heavy metal Sb(V) wastewater; c - heavy metal Cr(VI) wastewater. Specific embodiments

[0032] To enable those skilled in the art to understand the features and effects of the present invention, the following provides a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art for the present invention. In case of conflict, the definition in this specification shall prevail.

[0033] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not in any way limit the scope of the present invention, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0034] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual values within the ranges (including integers and fractions).

[0035] In this article, unless otherwise specified, "comprising", "including", "containing", "having" or similar terms cover the meanings of "consisting of" and "consisting essentially of". For example, "A comprises a" covers the meanings of "A comprises a and others" and "A only comprises a".

[0036] In this article, for the sake of brevity of description, all possible combinations of all technical features in each embodiment or example are not described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered as within the scope described in this specification.

[0037] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0038] In the following examples, conventional instruments and equipment in the art are used. For the experimental methods without specific conditions noted in the following examples, they are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer. In the following examples, various raw materials are used. Unless otherwise specified, commercially available products are used, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" represents weight percentage, "parts" represents weight parts, and the ratio represents weight ratio.

[0039] Example 1

[0040] A preparation method of carbon material supported complex nano zero-valent iron includes the following steps:

[0041] S1: Under normal temperature and pressure conditions, 1.0000 g of carbon nanotubes, 1.5000 g of biochar, 3.5000 g of iron sulfide and 3.9 mL of aminomethanetripionic acid are added to a three-necked flask containing 300 mL of deionized water, and stirred for 10 min to make them evenly mixed to obtain a mixed solution; the biochar is prepared from corn straw; the carbon nanotubes are multi-walled carbon nanotubes;

[0042] S2: 3.5000 g of potassium borohydride and 70 mL of deionized water are added to a 100 mL beaker and stirred until completely dissolved to obtain a potassium borohydride solution; the obtained potassium borohydride solution is gradually added dropwise to the mixed solution obtained in S1. Particles are gradually formed in the solution. After the addition is completed, the reaction is allowed to proceed for 15 min. The formed solid particles are separated by a magnet, washed with water, and vacuum freeze-dried at -40 °C to obtain a carbon material supported complex nano zero-valent iron.

[0043] Example 2

[0044] A preparation method of carbon material supported complex nano zero-valent iron includes the following steps:

[0045] S1: Under normal temperature and pressure conditions, 1.3000 g of carbon nanotubes, 1.7000 g of biochar, 3.8000 g of iron sulfide and 4.3 mL of aminomethanetripionic acid are added to a three-necked flask containing 350 mL of deionized water, and stirred for 13 min to make them evenly mixed to obtain a mixed solution; the biochar is prepared from rice husks;

[0046] S2: Add 4.0000 g of potassium borohydride and 85 mL of deionized water into a 100 mL beaker, stir until completely dissolved to obtain a potassium borohydride solution; gradually add the obtained potassium borohydride solution dropwise into the mixed solution obtained in S1. Particles gradually form in the solution. After the addition is complete, react fully for 20 min, use a magnet to separate the formed solid particles, wash with water, and vacuum freeze-dry at -40 °C to obtain a carbon material supported complex-state nano zero-valent iron.

[0047] Example 3

[0048] A preparation method of a carbon material supported complex-state nano zero-valent iron, comprising the following steps:

[0049] S1: Under normal temperature and pressure conditions, add 1.5000 g of carbon nanotubes, 2.0000 g of biochar, 4.0000 g of iron sulfide, and 4.8 mL of aminomethanetripionic acid into a three-necked flask containing 400 mL of deionized water, stir for 15 min to mix evenly to obtain a mixed solution; the biochar is prepared from corn straw;

[0050] S2: Add 4.5000 g of potassium borohydride and 100 mL of deionized water into a 100 mL beaker, stir until completely dissolved to obtain a potassium borohydride solution; gradually add the obtained potassium borohydride solution dropwise into the mixed solution obtained in S1. Particles gradually form in the solution. After the addition is complete, react fully for 25 min, use a magnet to separate the formed solid particles, wash with water, and vacuum freeze-dry at -50 °C to obtain a carbon material supported complex-state nano zero-valent iron.

[0051] Example 4

[0052] A preparation method of a carbon material supported complex-state nano zero-valent iron, comprising the following steps:

[0053] S1: Under normal temperature and pressure conditions, add 1.0000 g of carbon nanotubes, 3.0000 g of biochar, 2.1000 g of iron sulfide, and 5 mL of 3-aminopropanesulfonic acid into a three-necked flask containing 300 mL of deionized water, stir for 10 min to mix evenly to obtain a mixed solution; the biochar is prepared from corn straw;

[0054] S2: Add 3.5000 g of potassium borohydride and 70 mL of deionized water into a 100 mL beaker, stir until completely dissolved to obtain a potassium borohydride solution; gradually add the obtained potassium borohydride solution dropwise into the mixed solution obtained in S1. Particles gradually form in the solution. After the addition is complete, react fully for 15 min, use a magnet to separate the formed solid particles, wash with water, and vacuum freeze-dry at -40 °C to obtain a carbon material supported complex-state nano zero-valent iron.

[0055] Example 5

[0056] A preparation method of carbon material supported complex nano zero-valent iron includes the following steps:

[0057] S1: Under normal temperature and pressure conditions, add 1.1000 g of carbon nanotubes, 3.4000 g of biochar, 2.9000 g of iron sulfide, and 5.5 mL of 3-aminopropanesulfonic acid into a three-necked flask containing 340 mL of deionized water, stir for 12 min to mix evenly to obtain a mixed solution; the biochar is prepared from corn straw;

[0058] S2: Add 3.8000 g of potassium borohydride and 80 mL of deionized water into a 100 mL beaker, stir until completely dissolved to obtain a potassium borohydride solution; gradually add the obtained potassium borohydride solution dropwise into the mixed solution obtained in S1, particles gradually form in the solution, after the addition is completed, react fully for 17 min, use a magnet to separate the formed solid particles, wash with water, and vacuum freeze-dry at -48 °C to obtain a carbon material supported complex nano zero-valent iron.

[0059] Example 6

[0060] A preparation method of carbon material supported complex nano zero-valent iron includes the following steps:

[0061] S1: Under normal temperature and pressure conditions, add 1.1000 g of carbon nanotubes, 3.4000 g of biochar, 2.9000 g of iron sulfide, and 5.5 mL of 3-aminopropanesulfonic acid into a three-necked flask containing 340 mL of deionized water, stir for 12 min to mix evenly to obtain a mixed solution; the biochar is prepared from corn straw;

[0062] S2: Add 4.5000 g of potassium borohydride and 100 mL of deionized water into a 100 mL beaker, stir until completely dissolved to obtain a potassium borohydride solution; gradually add the obtained potassium borohydride solution dropwise into the mixed solution obtained in S1, particles gradually form in the solution, after the addition is completed, react fully for 25 min, use a magnet to separate the formed solid particles, wash with water, and vacuum freeze-dry at -50 °C to obtain a carbon material supported complex nano zero-valent iron.

[0063] Comparative Example 1

[0064] Carbon material supported nano zero-valent iron material, its preparation method is carried out according to the preparation method of carbon material supported complex nano zero-valent iron in Examples 1-6, but without adding hydroxy- or amino-containing compounds.

[0065] Figure 0 is a physical picture of the carbon material supported complexed nano zero-valent iron material. It can be seen from the figure that under the influence of hydroxy or amino group-containing compounds, there are slight differences in the color and particle size of the two synthesized nano zero-valent iron materials. This may be due to the different complexing abilities of different hydroxy or amino group-containing compounds, resulting in different particle sizes of the formed materials, and at the same time affecting the diffuse reflection of visible light, resulting in color differences. However, both materials are still in a fine particle state, which is beneficial to the adsorption and removal of pollutants.

[0066] Figure 2 Figure 4 is a scanning electron microscopy (SEM) image of the carbon material supported complexed nano zero-valent iron material. It can be seen from the figure that there are many agglomerated particles with different shapes and sizes around the massive carbon material, which is a significant feature of zero-valent iron. The larger specific surface area of the carbon material provides an ideal support for zero-valent iron, and at the same time, the agglomeration effect of zero-valent iron in both materials is better alleviated.

[0067] Figure 3 Figure 8 shows the X-ray powder diffraction (XRD) pattern of the carbon material supported complexed nano zero-valent iron material prepared by the present invention. The characteristic peaks indicated in the figure correspond to the characteristic diffraction peaks of the carbon material, and there are also diffuse peaks corresponding to the complexed zero-valent iron, indicating that the complexed nano zero-valent iron is successfully loaded on the carbon material.

[0068] Application Example 1

[0069] Weigh 0.05 g of the materials prepared in Examples 1-6 and Comparative Example 1 into 300 mL conical flasks, and add 50 mL of heavy metal Cd(II) wastewater with concentrations of 10, 20, 30, 40, and 50 mg / L respectively. Shake at room temperature. After reacting for 2 min, filter out the samples, and use flame atomic absorption to measure the simulated heavy metal Cd(II) wastewater. The comparison results are as shown in Figure 4 -a.

[0070] Application Example 2

[0071] Weigh 0.05 g of the materials prepared in Examples 1-6 and Comparative Example 1 into 300 mL conical flasks, and add 50 mL of heavy metal Sb(V) wastewater with concentrations of 10, 20, 30, 40, and 50 mg / L respectively. Shake at room temperature. After reacting for 2 min, filter out the samples, and use flame atomic absorption to measure the simulated heavy metal Sb(V) wastewater. The comparison results are as shown in Figure 4 -b.

[0072] Application Example 3

[0073] Weigh 0.05 g of the materials prepared in Examples 1-6 and Comparative Example 1 into a 300 mL conical flask, and add 50 mL of heavy metal Cr(VI) wastewater with concentrations of 20, 40, 60, 80, and 100 mg / L respectively. Shake at room temperature. After reacting for 2 min, filter out the samples. Use the diphenylcarbazide spectrophotometric method to measure the simulated heavy metal Cr(VI) wastewater, and the comparison results are as Figure 4 shown in -c.

[0074] It can be seen from Figure 4 the above that after adding the carbon material-supported complexed nano-zero-valent iron material, when the reaction time is 2 min, the removal rates of the simulated Cd(II) wastewater and Sb(V) wastewater with an initial concentration of 30 mg / L both reach 100%. The removal rate of the simulated Cr(VI) wastewater with an initial concentration of 60 mg / L can also reach 100%. The removal rates of the simulated Cd(II) wastewater and Sb(V) wastewater with an initial concentration of 40 mg / L are 98.9% and 97.8% respectively. The removal rate of the simulated Cr(VI) wastewater with an initial concentration of 80 mg / L is still 100%. Even the removal rates of the simulated Cd(II) and Sb(V) wastewater with an initial concentration of 50 mg / L are 97.3% and 96.9% respectively. The removal rate of the simulated Cr(VI) wastewater with an initial concentration of 100 mg / L is 98.7%. Moreover, the removal rate of this material is significantly better than that of the carbon material-supported nano-zero-valent iron material.

[0075] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A preparation method of carbon material supported complex nano zero-valent iron, characterized in that It includes the following steps: S1: Add the doped and mixed carbon materials, iron sulfide, and the compound containing hydroxyl or amino group into water, and stir to obtain a mixed solution; S2: Drop the potassium borohydride solution into the mixed solution for reaction, then perform solid-liquid separation to obtain the reactant. After washing and drying the reactant, a carbon material-supported complex nano-zero-valent iron is obtained; In S1, the compound containing hydroxyl or amino group is aminomethanetripionic acid or 3-aminopropanesulfonic acid; the stirring time is 10 min to 15 min; In S1, the doped and mixed carbon materials are prepared by mixing carbon nanotubes and biochar; the biochar is prepared from agricultural waste; In S1, when the compound containing hydroxyl or amino group is aminomethanetripionic acid, the dosage ratio of the carbon nanotubes, biochar, iron sulfide, the compound containing hydroxyl or amino group, and water is (1 - 1.5) g : (1.5 - 2.0) g : (3.5 - 4.0) g : (3.9 - 4.8) mL : (300 - 400) mL; In S1, when the compound containing hydroxyl or amino group is 3-aminopropanesulfonic acid, the dosage ratio of the carbon nanotubes, biochar, iron sulfide, the compound containing hydroxyl or amino group, and water is (1 - 1.3) g : (3.0 - 4.0) g : (2.1 - 3.3) g : (5.0 - 6.0) mL : (300 - 400) mL.

2. The preparation method of a carbon material supported complex state nano zero-valent iron according to claim 1, characterized in that, The agricultural waste includes corn straw, rice husk or reed; the carbon nanotubes are multi-walled carbon nanotubes.

3. The preparation method of a carbon material supported complex state nano zero-valent iron according to claim 1, characterized in that, In S2, the potassium borohydride solution is obtained by mixing potassium borohydride and water, and the dosage ratio of potassium borohydride and water is (3.5 - 4.5) g : (70 - 100) mL.

4. The preparation method of a carbon material supported complex nano zero-valent iron according to claim 1, characterized in that, In S2, the dosage ratio of the potassium borohydride solution and the mixed solution is (70 - 100) mL : (300 - 400) mL; the reaction time is 15 min to 25 min; the drying is vacuum freeze-drying, and the drying temperature is -50°C to -40°C.

5. A carbon material supported complex nano zero-valent iron, characterized in that, It is prepared by using the preparation method of a carbon material-supported complex nano-zero-valent iron described in any one of claims 1 to 4.

6. The application of the carbon material supported complex nano zero-valent iron according to claim 5, characterized in that, The carbon material-supported complex nano-zero-valent iron is used as a heavy metal remover in Cd(II)-containing wastewater with a concentration of 1 - 50 mg / L, Sb(V)-containing wastewater with a concentration of 1 - 50 mg / L, and Cr(VI)-containing wastewater with a concentration of 1 - 100 mg / L.

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