Heavy metal soil adsorbent based on carbon material and production process thereof

Abstract

The invention relates to the technical field of materials, and discloses a heavy metal soil adsorbent based on a carbon material and a production process of the heavy metal soil adsorbent, the soil adsorbent is prepared by taking a porous carbon material as a base material and heavy calcium carbonate, organic modified chlorite and the like as auxiliary materials through mixing, extrusion blank forming and sintering processes, the organic modified chlorite is large in specific surface area and can have more storage sites and adsorption sites, an interlayer structure of the organic modified chlorite can contain heavy metal, surface modified L-tyrosine can immobilize the heavy metal through the chelation of secondary amine and carboxyl, the prepared adsorbent has high heavy metal ion adsorption capacity, and in addition, the adsorption capacity of the adsorbent is improved. The heavy calcium carbonate, the organic modified chlorite and other auxiliary materials are compounded with the porous carbon material, so that the use amount of the porous carbon material is effectively reduced, the use amount of carbon is reduced, and the economical efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of material technology, and in particular to a heavy metal soil adsorbent based on carbon materials and a production process thereof. Background Art

[0002] With the rapid advancement of industrialization and urbanization, the problem of heavy metal contaminated soil is becoming increasingly serious. Heavy metals are hidden, cumulative and difficult to degrade in the soil. They not only affect the activity of soil microorganisms and destroy the soil structure, but also accumulate in organisms through the food chain, ultimately endangering human health and causing various diseases. Therefore, it is urgent to carry out the remediation of heavy metal contaminated soil. Heavy metal soil adsorbents, as an effective soil remediation technology, can adsorb and fix heavy metal ions in the soil through physical and chemical effects, reduce their biological effectiveness and mobility, and have become a research hotspot in the current field of soil pollution control with their advantages of high efficiency, environmental protection and economy.

[0003] However, common heavy metal soil adsorbents are mainly activated carbon materials. Utilizing their rich pore structure, they can effectively enrich heavy metal ions in the soil. However, activated carbon materials can generally only achieve the fixation of heavy metals in the soil through physical adsorption, which mainly relies on the adsorption capacity of activated carbon materials. This requires a large consumption of activated carbon materials and requires multiple additions or replacements of activated carbon, which increases the cost and workload of repair. Based on this, the present invention provides a heavy metal soil adsorbent with a high adsorption capacity and can exhibit excellent heavy metal adsorption effects. Summary of the invention

[0004] In order to solve the problems mentioned in the background technology, the object of the present invention is to provide a heavy metal soil adsorbent based on carbon materials and a production process thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A heavy metal soil adsorbent based on carbon material, which is made of the following raw materials in parts by weight:

[0007] 35-45 parts of porous carbon material, 5-10 parts of heavy calcium carbonate, 2-4.5 parts of organic modified chlorite, 3-6 parts of diatomaceous earth, and 4-10 parts of binder.

[0008] As a further solution of the present invention, the preparation method of the porous carbon material is as follows:

[0009] Step S1: Add maltose to deionized water, stir and mix evenly to form a reaction solution. Then, add a crosslinking agent and a catalyst to the reaction solution. After adding, start heating and raise the temperature to 50 - 60 °C. Continuously stir for 8 - 12 h, then stop heating, filter out the product, and after washing and vacuum drying, crosslinked maltose is obtained.

[0010] Step S2: Grind and mix crosslinked maltose and potassium hydroxide evenly, then transfer them to a tubular furnace, protect with nitrogen, maintain the temperature at 650 - 750 °C, calcine for 1 - 3 h, take out, wait for it to cool, wash until neutral, and vacuum dry to obtain a porous carbon material.

[0011] As a further solution of the present invention, in step S1, the crosslinking agent is iminodiacetic acid or nitrilotriacetic acid.

[0012] As a further solution of the present invention, in step S1, the catalyst is a mixture of dicyclohexylcarbodiimide and 4 - dimethylaminopyridine, and the mass ratio is 10:2 - 3.5.

[0013] As a further solution of the present invention, in step S2, the mass ratio of crosslinked maltose to potassium hydroxide is 1:3 - 4.

[0014] In the above technical solution, under the action of the catalyst, the hydroxyl groups in the maltose structure can carry out continuous condensation reactions with the substituted carboxyl groups in the crosslinking agent structure, thereby realizing the crosslinking of maltose to obtain crosslinked maltose. Then, using potassium hydroxide as a pore - forming agent, first activate the crosslinked maltose, and then carry out carbonization treatment on it at high temperature. Using maltose as a carbon source, the nitrogen element in the crosslinking agent structure will be doped into the carbon in the form of nitrogen element doping to obtain a porous carbon material containing nitrogen element doping.

[0015] As a further solution of the present invention, the preparation method of the organic - modified chlorite is as follows:

[0016] Step SS1: Add chlorite to ethanol, ultrasonically disperse evenly, then add a halogenated modification reagent and triethylamine to the formed dispersion. After adding, raise the temperature to 50 - 60 °C, continuously stir for 4 - 8 h, then centrifuge out the solid material, and after washing and vacuum drying, halogenated chlorite is obtained.

[0017] Step SS2: Disperse the halogenated chlorite in deionized water to form a uniform dispersion. Then, add L - tyrosine and an acid - binding agent to the dispersion. After adding, start heating and raise the temperature to 80 - 90 °C, stir for 4 - 6 h, then cool and discharge. After washing and vacuum drying, organic - modified chlorite is obtained.

[0018] As a further aspect of the present invention, in step SS1, the halogenated modification reagent is any one of chloroacetyl chloride, bromoacetyl bromide, 4-bromobutyryl chloride or 4-chlorobutyryl chloride.

[0019] As a further aspect of the present invention, in step SS2, the acid-binding agent is pyridine.

[0020] In the above technical solution, since the chlorite surface contains hydroxyl groups, it can react with the acyl halide in the structure of the halogenated modification reagent under the action of triethylamine to obtain halogenated chlorite. Then, under the action of the acid-binding agent, the amino group in the structure of L-tyrosine can undergo a substitution reaction with the halogen substituent of the halogenated chlorite, thereby modifying L-tyrosine on the surface of the chlorite to obtain organically modified chlorite.

[0021] As a further aspect of the present invention, the preparation method of the binder is as follows:

[0022] Step SSS1: Add konjac gum to deionized water to prepare a konjac gum aqueous solution with a mass fraction of 25-35%; dissolve polyethylene glycol in deionized water to prepare a polyethylene glycol aqueous solution with a mass fraction of 10-20%; according to a volume ratio of 1:1, stir and mix the two evenly to form a precursor solution.

[0023] Step SSS2: Add sodium tetraborate to the precursor solution. After adding, raise the temperature to 50-60 °C, keep stirring for 3-4 h, stop heating, filter out the product, and that's it.

[0024] In the above technical solution, using konjac gum and polyethylene glycol as the main components of the colloid, and using sodium tetraborate as a cross-linking agent, konjac gum and polyethylene glycol are cross-linked and polymerized to obtain a composite binder.

[0025] A production process of a heavy metal soil adsorbent based on carbon materials, comprising the following steps:

[0026] The first step: Add the prepared porous carbon material, heavy calcium carbonate, organically modified chlorite and diatomaceous earth weighed according to parts by weight to a mixing kettle, control the rotation speed at 80-100 rpm, mechanically stir and mix for 20-30 min, then add the binder to the mixing kettle, and continue to stir for 10-20 min to form a precursor material.

[0027] The second step: Place the precursor material in a mold, extrude it into a blank, place the blank in a sintering furnace, calcine it under nitrogen protection at a temperature of 200-300 °C for 1-2 h, take it out, wait for it to cool, demold it, and grind it through an 80-100 mesh sieve, and that's it.

[0028] The beneficial effects of the present invention:

[0029] 1) The present invention effectively reduces the dosage of porous carbon materials and improves the economy by using auxiliary materials such as heavy calcium carbonate and organically modified chlorite and compounding them with porous carbon materials.

[0030] 2) The present invention realizes the coordination adsorption of heavy metal ions in soil by doping elements into the porous carbon materials and utilizing the lone pair electrons provided by nitrogen elements. Moreover, the porous carbon materials prepared by the present invention through crosslinking have a richer pore structure and a larger specific surface area, and can have more storage sites and adsorption sites, thus showing a higher adsorption capacity.

[0031] 3) The present invention prepares organically modified chlorite by modifying L-tyrosine on the surface of chlorite. First, the interlayer structure of chlorite itself can accommodate heavy metals, and the surface-modified L-tyrosine can realize the immobilization of heavy metals through the chelation of secondary amine and carboxyl groups, thus forming a dual adsorption mode of first physically adsorbing to increase the concentration of heavy metal ions around the adsorption material and then chemically immobilizing, so that the prepared adsorption material can show excellent adsorption performance.

[0032] 4) The present invention designs and prepares a unique biomass binder to bond each component of the adsorption material. Compared with konjac gum, this binder with a konjac gum-polyethylene glycol crosslinked structure has a higher cohesive energy and can show excellent bonding performance, achieving good bonding between components with a small amount of addition and avoiding the problem that the pore structure of each component is blocked due to the large amount of binder used, resulting in a reduction in the adsorption effect of the adsorption material.

[0033] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0035] Figure 1 It is a scanning electron microscope image of a porous carbon material. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] Example 1. A heavy metal soil adsorbent based on carbon materials is made of the following raw materials by weight:

[0038] 35 parts of porous carbon material, 5 parts of heavy calcium carbonate, 2 parts of organically modified chlorite, 3 parts of diatomite, and 4 parts of binder.

[0039] The preparation method of the adsorbent is as follows:

[0040] First step: Add the weighed porous carbon material, heavy calcium carbonate, organically modified chlorite, and diatomite to a mixing kettle, control the rotation speed at 80 rpm, mechanically stir and mix for 30 min, then add the binder to the mixing kettle and continue to stir for 10 min to form a precursor material;

[0041] Second step: Place the precursor material in a mold, extrude it into a blank, place the blank in a sintering furnace, calcine it at a temperature of 200 °C for 2 h under nitrogen protection, take it out, wait for it to cool, demold it, and grind it through a 100-mesh sieve.

[0042] Example 2. A heavy metal soil adsorbent based on carbon materials is made of the following raw materials by weight:

[0043] 36 parts of porous carbon material, 6 parts of heavy calcium carbonate, 4 parts of organically modified chlorite, 5 parts of diatomite, and 8 parts of binder.

[0044] The preparation method of the adsorbent is as follows:

[0045] First step: Add the weighed porous carbon material, heavy calcium carbonate, organically modified chlorite, and diatomite to a mixing kettle, control the rotation speed at 100 rpm, mechanically stir and mix for 25 min, then add the binder to the mixing kettle and continue to stir for 20 min to form a precursor material;

[0046] Second step: Place the precursor material in a mold, extrude it into a blank, place the blank in a sintering furnace, calcine it at a temperature of 280 °C for 1 h under nitrogen protection, take it out, wait for it to cool, demold it, and grind it through a 100-mesh sieve.

[0047] Example 3. A heavy metal soil adsorbent based on carbon materials is made of the following raw materials by weight:

[0048] 45 parts of porous carbon material, 10 parts of heavy calcium carbonate, 4.5 parts of organically modified chlorite, 6 parts of diatomite, and 10 parts of binder.

[0049] The preparation method of the adsorbent is as follows:

[0050] Step 1: Weigh and prepare the porous carbon material, heavy calcium carbonate, organically modified chlorite, and diatomaceous earth according to the parts by weight, and add them to a mixing kettle. Control the rotation speed at 100 rpm. After mechanically stirring and mixing for 30 min, add the binder to the mixing kettle and continue stirring for 20 min to form a precursor material;

[0051] Step 2: Place the precursor material in a mold, extrude it into a blank, place the blank in a sintering furnace, calcine it under nitrogen protection at a temperature of 300 °C for 1 h, take it out, wait for it to cool, demold it, and grind it through a 100-mesh sieve to obtain the product.

[0052] Comparative Example 1: A heavy metal soil adsorbent based on carbon material, prepared from the following raw materials according to the parts by weight:

[0053] 36 parts of commercially available porous carbon material, 6 parts of heavy calcium carbonate, 4 parts of organically modified chlorite, 5 parts of diatomaceous earth, and 8 parts of binder.

[0054] The preparation method of this adsorbent is as follows:

[0055] Step 1: Weigh and prepare the commercially available porous carbon material, heavy calcium carbonate, organically modified chlorite, and diatomaceous earth according to the parts by weight, and add them to a mixing kettle. Control the rotation speed at 100 rpm. After mechanically stirring and mixing for 25 min, add the binder to the mixing kettle and continue stirring for 20 min to form a precursor material;

[0056] Step 2: Place the precursor material in a mold, extrude it into a blank, place the blank in a sintering furnace, calcine it under nitrogen protection at a temperature of 280 °C for 1 h, take it out, wait for it to cool, demold it, and grind it through a 100-mesh sieve to obtain the product.

[0057] The commercially available porous carbon material is the first-grade bamboo charcoal purchased from Anhui Xingheng Environmental Protection Technology Co., Ltd., with a fixed carbon content of ≥90.0%.

[0058] Comparative Example 2: A heavy metal soil adsorbent based on carbon material, prepared from the following raw materials according to the parts by weight:

[0059] 36 parts of porous carbon material, 6 parts of heavy calcium carbonate, 4 parts of chlorite, 5 parts of diatomaceous earth, and 8 parts of binder.

[0060] The preparation method of this adsorbent is as follows:

[0061] Step 1: Weigh and prepare the porous carbon material, heavy calcium carbonate, chlorite, and diatomaceous earth according to the parts by weight, and add them to a mixing kettle. Control the rotation speed at 100 rpm. After mechanically stirring and mixing for 25 min, add the binder to the mixing kettle and continue stirring for 20 min to form a precursor material;

[0062] Step 2: Place the precursor material in a mold, extrude it into a blank, place the blank in a sintering furnace, calcine it under nitrogen protection at a temperature of 280 °C for 1 h, take it out, wait for it to cool, demold it, and grind it through a 100-mesh sieve to obtain the product.

[0063] Comparative Example 3: A heavy metal soil adsorbent based on carbon materials, prepared from the following raw materials by weight:

[0064] 36 parts of porous carbon material, 6 parts of heavy calcium carbonate, 5 parts of diatomaceous earth, and 8 parts of binder.

[0065] The preparation method of the adsorbent is as follows:

[0066] Step 1: Add the weighed and prepared porous carbon material, heavy calcium carbonate, and diatomaceous earth to a mixing kettle, control the rotation speed at 100 rpm, mechanically stir and mix for 25 min, then add the binder to the mixing kettle and continue to stir for 20 min to form a precursor material;

[0067] Step 2: Place the precursor material in a mold, extrude it into a blank, place the blank in a sintering furnace, calcine it under nitrogen protection at a temperature of 280 °C for 1 h, take it out, wait for it to cool, demold it, and grind it through a 100-mesh sieve to obtain the product.

[0068] Comparative Example 4: A heavy metal soil adsorbent based on carbon materials, prepared from the following raw materials by weight:

[0069] 36 parts of porous carbon material, 6 parts of heavy calcium carbonate, 4 parts of organically modified chlorite, 5 parts of diatomaceous earth, and 8 parts of konjac gum.

[0070] The preparation method of the adsorbent is as follows:

[0071] Step 1: Add the weighed and prepared porous carbon material, heavy calcium carbonate, organically modified chlorite, and diatomaceous earth to a mixing kettle, control the rotation speed at 100 rpm, mechanically stir and mix for 25 min, then add the konjac gum to the mixing kettle and continue to stir for 20 min to form a precursor material;

[0072] Step 2: Place the precursor material in a mold, extrude it into a blank, place the blank in a sintering furnace, calcine it under nitrogen protection at a temperature of 280 °C for 1 h, take it out, wait for it to cool, demold it, and grind it through a 100-mesh sieve to obtain the product.

[0073] The porous carbon materials in the above examples and comparative examples are prepared by the following method:

[0074] Step S1: Add 1.8 g of maltose to deionized water, stir and mix evenly to form a reaction solution. Then add 0.4 g of nitrilotriacetic acid, 0.1 g of dicyclohexylcarbodiimide and 0.03 g of 4-dimethylaminopyridine to the reaction solution. After adding, start heating, raise the temperature to 50 °C, continuously stir for 9 h, then stop heating, filter out the product, and after washing and vacuum drying, crosslinked maltose is obtained.

[0075] Step S2: Grind 5 g of crosslinked maltose and 18 g of potassium hydroxide evenly, then transfer them to a tube furnace, protect with nitrogen, maintain the temperature at 700 °C, calcine for 2 h, take out, wait for it to cool, wash until neutral, and vacuum dry to obtain the porous carbon material.

[0076] Figure 1 Figure 7 is the scanning electron microscope image of the porous carbon material. It can be analyzed that its pore structure is rich, with macropores, mesopores and micropores, and can expose more active adsorption and storage sites.

[0077] The organically modified chlorite in the above examples and comparative examples was prepared by the following method:

[0078] Step SS1: Add 0.6 g of chlorite to ethanol, ultrasonically disperse evenly, then add 1.5 g of bromoacetyl bromide and 0.3 g of triethylamine to the formed dispersion. After adding, raise the temperature to 55 °C, continuously stir for 6 h, then centrifuge out the solid material, and after washing and vacuum drying, halogenated chlorite is obtained.

[0079] Step SS2: Disperse 0.5 g of halogenated chlorite in deionized water to form a uniform dispersion. Then add 1.2 g of L-tyrosine and 0.1 g of pyridine to the dispersion. After adding, start heating, raise the temperature to 90 °C, stir for 6 h, then cool and discharge, and after washing and vacuum drying, organically modified chlorite is obtained.

[0080] Use a PE-2400 type elemental analyzer to analyze the percentage content of nitrogen element in the organically modified chlorite, and the test result is 4.59%.

[0081] The binder in the above examples and comparative examples was prepared by the following method:

[0082] Step SSS1: Add konjac gum to deionized water to prepare a konjac gum aqueous solution with a mass fraction of 30%; dissolve polyethylene glycol in deionized water to prepare a polyethylene glycol aqueous solution with a mass fraction of 15%; take 100 mL of each and stir and mix evenly to form a precursor solution.

[0083] Step SSS2: Add 1.5 g of sodium tetraborate to the precursor solution. After adding, raise the temperature to 60 °C, keep stirring for 4 h, stop heating, and filter out the product.

[0084] Test example: Take the heavy metal - contaminated soil in a certain place as a sample. Remove the sundries and animal and plant waste in the sample, add it to water and stir - mix to prepare a suspension with a solid content of 200 g / L. Take 1.4 L of the suspension, and drop 10 mL of hydrochloric acid solution with a concentration of 1 mol / L into it. After stirring for 30 min, divide it evenly into 7 groups of test - solution experimental groups, namely Example 1 - Example group and Comparative Example 1 - Comparative Example 4 groups. Add 0.5 g of the corresponding soil adsorbent to each experimental group. After oscillating and adsorbing for 6 h, let it stand for stratification. Take the supernatant. By using an ultraviolet spectrophotometer, measure the concentrations of heavy - metal copper ions in the test solution and the supernatant. Use the formula \(W = [(C_0 - C)\times V] / m\) to calculate the adsorption capacity, where \(C_0\) is the concentration of copper ions in the test solution, \(C\) is the concentration of copper ions in the supernatant, \(V\) is the volume of the test solution, and \(m\) is the mass of the adsorbent. The test results are shown in the following table:

[0085]

[0086]

[0087] According to the analysis of the test results, it can be seen that the soil adsorbent prepared in the examples of the present invention shows a relatively high heavy - metal ion adsorption effect. After replacing the porous carbon material with commercially available activated carbon, there is an obvious phenomenon of reduced adsorption capacity. This is because the pore structure of the commercially available activated - carbon material is not as rich as that of the porous carbon material of this application, and both the heavy - metal ion adsorption sites and storage sites are less, and it does not contain element doping. After replacing the organically modified chlorite with un - surface - modified chlorite, the surface - modified substances cannot be used to chelate heavy - metal ions, so the adsorption capacity of the adsorbent also shows poor performance. When using konjac gum alone as a binder, due to insufficient bonding strength, active components fall off during the sintering process, which has a negative impact on the adsorption capacity of the adsorbent.

[0088] In this article, specific examples are used to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea, including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The protection scope of the present invention patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements approximately the same as the literal description of the claims, or if they include equivalent structural elements that have no substantial difference from the literal description of the claims, then these other embodiments should also be included within the scope of the claims.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heavy metal soil adsorbent based on carbon materials, characterized in that, By weight parts, it is made of the following raw materials: 35-45 parts of porous carbon material, 5-10 parts of heavy calcium carbonate, 2-4.5 parts of organically modified chlorite, 3-6 parts of diatomite, 4-10 parts of binder.

2. The heavy metal soil adsorbent based on carbon materials according to claim 1, wherein The preparation method of the porous carbon material is as follows: Step S1: Add maltose to deionized water, stir and mix evenly to form a reaction solution. Then add a crosslinking agent and a catalyst to the reaction solution. After adding, turn on the heating and raise the temperature to 50-60°C. Continuously stir for 8-12 h, then stop heating, filter out the product, and after washing and vacuum drying, obtain crosslinked maltose; Step S2: Grind and mix crosslinked maltose and potassium hydroxide evenly, then transfer them to a tubular furnace, protect with nitrogen, maintain the temperature at 650-750°C, calcine for 1-3 h, take out, wait for it to cool, wash to neutral, and vacuum dry to obtain the porous carbon material.

3. The heavy metal soil adsorbent based on carbon material according to claim 2, characterized in that, In step S1, the crosslinking agent is iminodiacetic acid or nitrilotriacetic acid.

4. The heavy metal soil adsorbent based on carbon material according to claim 2, wherein In step S1, the catalyst is a mixture of dicyclohexylcarbodiimide and 4-dimethylaminopyridine, and the mass ratio is 10:2-3.

5.

5. The heavy metal soil adsorbent based on carbon material according to claim 2, characterized in that In step S2, the mass ratio of crosslinked maltose to potassium hydroxide is 1:3-4.

6. The heavy metal soil adsorbent based on carbon material according to claim 1, wherein The preparation method of the organically modified chlorite is as follows: Step SS1: Add chlorite to ethanol, ultrasonically disperse evenly, then add a halogenated modification reagent and triethylamine to the formed dispersion. After adding, raise the temperature to 50-60°C, continuously stir for 4-8 h, then centrifuge out the solid material, and after washing and vacuum drying, obtain halogenated chlorite; Step SS2: Disperse halogenated chlorite in deionized water to form a uniform dispersion. Then add L-tyrosine and an acid-binding agent to the dispersion. After adding, turn on the heating and raise the temperature to 80-90°C, stir for 4-6 h, then cool and discharge, and after washing and vacuum drying, obtain the organically modified chlorite.

7. The heavy metal soil adsorbent based on carbon material according to claim 6, characterized in that, In step SS1, the halogenated modification reagent is any one of chloroacetyl chloride, bromoacetyl bromide, 4-bromobutyryl chloride or 4-chlorobutyryl chloride.

8. The heavy metal soil adsorbent based on carbon material according to claim 6, characterized in that, In step SS2, the acid-binding agent is pyridine.

9. The heavy metal soil adsorbent based on carbon material according to claim 1, wherein, The preparation method of the binder is as follows: Step SSS1: Add konjac gum to deionized water to prepare a konjac gum aqueous solution with a mass fraction of 25-35%; dissolve polyethylene glycol in deionized water to prepare a polyethylene glycol aqueous solution with a mass fraction of 10-20%; according to a volume ratio of 1:1, stir and mix them evenly to form a precursor solution; Step SSS2: Add sodium tetraborate to the precursor solution. After adding, raise the temperature to 50-60°C, keep stirring for 3-4 h, stop heating, and filter out the product.

10. A production process of a heavy metal soil adsorbent based on carbon materials as described in claim 1, characterized in that, It includes the following steps: The first step: Add the porous carbon material, heavy calcium carbonate, organically modified chlorite and diatomite weighed and prepared according to weight parts to a mixing kettle, control the rotation speed at 80-100 rpm, mechanically stir and mix for 20-30 min, then add the binder to the mixing kettle, and continue to stir for 10-20 min to form a precursor material; Step 2: Place the precursor material in a mold, extrude it into a formed part, place the formed part in a sintering furnace, calcine it under nitrogen protection at a temperature of 200-300°C for 1-2 hours, take it out, wait for it to cool, demold it, and grind it through an 80-100 mesh sieve to obtain the finished product.

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