Dual-functional filtration carbon material for drinking water and preparation method and application thereof

Abstract

The application belongs to the technical field of drinking water purification materials, and discloses a drinking water dual-function filter carbon material with high efficiency in removing heavy metals, high mineral retention rate and high safety, and a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing primary carbonization material, a binder, a pore-forming agent and a transition metal salt solution, and then kneading and shaping to obtain a blank after drying; (2) sequentially performing secondary carbonization treatment and heat activation treatment on the blank, and then washing with water until the conductivity of the washing liquid is constant, and drying to obtain a porous carrier; (3) immersing the porous carrier in an oxidation modification solution, and then performing solid-liquid separation, washing with water and drying to obtain a porous oxidation carrier; and (4) immersing the hot porous oxidation carrier in an alkaline polyamine modification solution, and adjusting the pH of the mixture to be close to neutral when the temperature of the porous oxidation carrier is higher than that of the alkaline polyamine modification solution and the temperature is cooled to room temperature, and then performing heat treatment after solid-liquid separation to obtain the drinking water dual-function filter carbon material.

Description

Technical Field

[0001] This invention relates to the technical field of drinking water purification materials, and more specifically, to dual-function drinking water filtration carbon materials, their preparation methods, and applications. Background Technology

[0002] Although activated carbon materials have been widely used in key purification units of drinking water treatment systems, existing materials cannot simultaneously meet the following requirements: (1) High selective removal of heavy metal ions: For example, commercially available activated carbon (such as coconut shell carbon) typically has an adsorption capacity of 10~30 mg / g for Pb²⁺ and 5~20 mg / g for Cd²⁺, and the removal of Cd²⁺ depends on physical adsorption, resulting in large efficiency fluctuations. (2) Precise retention of essential minerals: Traditional modification methods (such as acid oxidation and metal loading) can improve the adsorption performance of heavy metals, but they can also lead to the simultaneous removal of essential minerals such as calcium and magnesium (loss rate > 60%), affecting the health properties of drinking water. (3) Material safety for long-term use: Some technologies use nano-silver antibacterial agents or metal oxides (such as Fe3O4) to enhance adsorption performance, but this may cause metal ion leaching, which does not meet the safety standards for drinking water materials and poses potential health risks. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a dual-function filter carbon material for drinking water that is highly efficient in removing heavy metals, has a high mineral retention rate, and is highly safe, as well as its preparation method and application. The technical solution is as follows:

[0004] A method for preparing a dual-function carbon filter material for drinking water includes the following steps:

[0005] (1) The primary carbonized material, binder, pore-forming agent and transition metal salt solution are mixed and kneaded into shape, and then dried to obtain a green body;

[0006] (2) The green body is subjected to secondary carbonization and thermal activation treatment in sequence, cooled and washed with water until the conductivity of the washing liquid is constant, and dried to obtain a porous carrier;

[0007] (3) The porous support is immersed in the oxidation modification solution, and after solid-liquid separation, it is washed with water and dried to obtain the porous oxidation support;

[0008] (4) The hot porous oxide carrier is immersed in an alkaline polyamine modified solution. The temperature of the porous oxide carrier is higher than that of the alkaline polyamine modified solution. When the temperature is cooled to room temperature, the pH of the mixture is adjusted to be close to neutral. After solid-liquid separation, heat treatment is performed to obtain a dual-function filter carbon material for drinking water.

[0009] As a further improvement to the above preparation method: in step (1), the primary carbonization material is prepared by heating bamboo powder, coconut shell, apricot shell or walnut shell at 450-600℃ under an inert atmosphere for 1-3 hours; the binder is at least one of coal tar, phenolic resin, carboxymethyl cellulose and starch; the pore-forming agent is at least one of ammonium bicarbonate, urea and melamine; the transition metal salt is at least one of ferric chloride, ferrous sulfate, ferric nitrate, copper chloride and copper sulfate.

[0010] As a further improvement to the above preparation method: in step (1), the mass ratio of primary carbonized material, binder, pore-forming agent and transition metal salt is 100:(30-40):(5-10):(1.5-3); the kneading aid is water.

[0011] As a further improvement to the above preparation method: in step (2), the secondary carbonization treatment is to keep warm at 500-700℃ in an inert atmosphere for 1-2 hours.

[0012] As a further improvement to the above preparation method: In step (2), the thermal activation treatment includes two stages. The first stage is to keep warm at 850-950℃ in a water vapor atmosphere for 1-3 hours. The second stage is to introduce a mixture of water vapor and air and continue to keep warm for 2-10 minutes. The volume fraction of air in the mixture is 5-10 vol.

[0013] As a further improvement to the above preparation method: in step (3), the oxidative modification solution is a hydrogen peroxide solution with a mass fraction of 10-20%, and the solid-liquid ratio of the porous carrier to the oxidative modification solution is 1g:(20-40)mL, and it is immersed at 30-50℃ for 4-6 hours.

[0014] As a further improvement to the above preparation method: in step (4), the polyamine modification solution is an aqueous solution of branched polyethyleneimine with a mass concentration of 5-12%, a pH of 10-12, and a temperature of 30-50℃, and the weight-average molecular weight of the branched polyethyleneimine is 25000-70000; the temperature of the porous oxidation support is 120-140℃; and the solid-liquid ratio of the porous oxidation support to the polyamine modification solution is 1g:(20-40)mL.

[0015] As a further improvement to the above preparation method: in step (4), 0.5-2.0 mol / L hydrochloric acid solution is added dropwise to the mixture until the pH value is 6.5-7.5, and then the mixture is allowed to stand and age for 2-4 hours at this pH value before solid-liquid separation is performed; the heat treatment temperature is 120-150℃ and the heat treatment time is 4-8 hours.

[0016] The dual-function carbon filter material for drinking water is prepared by the above-described preparation method.

[0017] The drinking water purification element comprises a dual-function drinking water filtration carbon material prepared by the above-mentioned preparation method.

[0018] The dual-function drinking water filtration carbon material, its preparation method, and its application of the present invention have the following advantages:

[0019] 1. This invention constructs a unique "in-situ Fenton self-etching" mechanism by pre-embedding transition metal salts in the raw materials and cleverly combining a specific two-stage thermal activation and oxidation process. The residual transition metal sites act as catalysts in step (3), inducing hydrogen peroxide to generate high-energy free radicals, which not only clears the micropores but also etches an appropriate amount of mesopores on the carbon skeleton, significantly increasing the specific surface area. This precisely regulated pore structure mainly targets the adsorption of heavy metal ions and organic pollutants, while beneficial mineral ions such as calcium and magnesium are not excessively retained because their hydration radii do not match the specific chelation sites, thus achieving a high mineral retention rate of "removing harmful substances and retaining beneficial ones". Preferably, when the second stage of step (2) uses a mixture of water vapor and 5-10 vol% air for short-term treatment, metastable oxidation defects can be pre-formed on the carbon surface. This not only prevents excessive ablation of the carbon skeleton, but also greatly improves the wettability and reactivity of hydrogen peroxide in step (3), thereby generating extremely high density of hydroxyl and carboxyl sites on the carbon surface, laying a solid foundation for subsequent functional grafting.

[0020] 2. This invention utilizes a dual synergistic mechanism of "thermally driven negative pressure adsorption" and "chemical bonding" to solve the problems of low loading and easy loss in traditional amination modification. A high-temperature porous oxidation carrier is rapidly cooled and immersed in a polyamine modification solution. The internal negative pressure generated by the temperature difference forcefully pumps high-viscosity polyamine molecules into deep pores. Simultaneously, the abundant oxygen-containing functional groups on the carrier surface undergo condensation reactions with the amine groups, achieving strong chemical bonding. This fundamentally eliminates the risk of leaching of the modifier into the water, significantly improving the drinking safety of the material. Preferably, when the porous oxidation carrier temperature is 120-140℃ and branched polyethyleneimine with a weight-average molecular weight of 25,000-70,000 is selected, its hyperbranched structure provides an extremely high density of chelation sites, enabling rapid capture and deep removal of heavy metal ions such as lead and cadmium. Furthermore, the large molecular chains are difficult to penetrate the filter element into the water, further ensuring the safety of the effluent.

[0021] 3. This invention further enhances the structural stability and safety of the material through a unique pH adjustment and thermal cross-linking process. After amine loading, the pH is adjusted to neutral and heat-treated to induce conformational coiling and intermolecular cross-linking of the polyethyleneimine molecular chains adsorbed within the pores, firmly locking them within the carbon framework and effectively preventing the swelling and loss of amine molecules during long-term water flow. Preferably, when the pH is adjusted to 6.5-7.5 with hydrochloric acid and heat-treated at 120-150℃, the material surface is neutral, which not only ensures good biocompatibility but also inhibits bacterial growth. This results in a carbon material that maintains high throughput and efficient heavy metal removal while exhibiting excellent hygiene and safety for long-term use.

[0022] The embodiments of the invention provided in this specification will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the embodiments of the invention provided in this specification will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the embodiments of the invention provided in this specification. Attached Figure Description

[0023] The accompanying drawings, which form part of the embodiments of the invention provided in this specification, are used to aid in understanding the embodiments of the invention provided in this specification. The content provided in the drawings and the related descriptions in the embodiments of the invention provided in this specification can be used to explain the embodiments of the invention provided in this specification, but do not constitute an undue limitation on the embodiments of the invention provided in this specification. In the drawings:

[0024] Figure 1 This is a SEM image of the dual-function drinking water filtration carbon material of Embodiment 1 of the present invention.

[0025] Figure 2 The image shows the FT-IR spectrum of the dual-function drinking water filtration carbon material of Example 1 of this invention. Detailed Implementation

[0026] The embodiments of the invention provided in this specification will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the embodiments of the invention provided in this specification based on these descriptions. Before describing the embodiments of the invention provided in this specification in conjunction with the accompanying drawings, it should be particularly noted that:

[0027] The technical solutions and features provided in the embodiments of the invention provided in this specification, including the following description, can be combined with each other without conflict.

[0028] Furthermore, the embodiments of the inventions provided in this specification mentioned below are generally only a portion of the embodiments of the inventions provided in this specification, and not all of them. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the inventions provided in this specification without creative effort should fall within the scope of protection of the embodiments of the inventions provided in this specification.

[0029] Regarding the terminology and units in the embodiments of the invention provided in this specification: The terms "comprising," "including," "having," and any variations thereof in the description, claims, and related parts of the embodiments of the invention provided in this specification are intended to cover non-exclusive inclusion. Furthermore, other relevant terms and units in the embodiments of the invention provided in this specification can be reasonably interpreted based on the relevant content of the embodiments of the invention provided in this specification. Example 1

[0030] The preparation method of the dual-function drinking water filtration carbon material in this embodiment includes the following steps:

[0031] (1) Bamboo powder was kept at 600°C for 2 hours under an inert atmosphere to obtain a primary carbonized material. Then, 100 parts by weight of the above primary carbonized material were weighed and mixed with 35 parts by weight of carboxymethyl cellulose, 8 parts by weight of ammonium bicarbonate and 2.5 parts by weight of ferric chloride, and an appropriate amount of water was added as a kneading aid. After kneading and drying, a green body was obtained.

[0032] (2) First, place the green body in an inert atmosphere and keep it at 600℃ for 1 hour to complete the secondary carbonization; then carry out two-stage thermal activation: the first stage is to keep it at 900℃ in a steam atmosphere for 3 hours, and the second stage is to maintain the temperature and pass a steam mixture containing 8 vol% air for 5 minutes. After the treatment is completed, cool it, wash it with water until the conductivity of the washing liquid is constant, and dry it to obtain a porous carrier.

[0033] (3) The porous support was immersed in a 15% hydrogen peroxide solution at a solid-liquid ratio of 1g:30mL and soaked at 40℃ for 5 hours. After solid-liquid separation, water washing and drying, a porous oxidation support was obtained.

[0034] (4) First, prepare an alkaline polyamine modification solution with a temperature of 40℃, a pH of 11, and a mass concentration of 10%, wherein the solute is branched polyethyleneimine with a weight average molecular weight of 70,000; simultaneously, heat the porous oxide carrier to 140℃. At a solid-liquid ratio of 1g:30mL, rapidly immerse the hot porous oxide carrier in the relatively cool modification solution (in a reactor equipped with a reflux condenser to prevent boiling and splashing). After the system naturally cools to room temperature, add 1mol / L hydrochloric acid solution dropwise to the mixture to adjust the pH to 6.5-7.5, and allow it to stand and age for 3 hours in this neutral environment. Finally, separate the solids and heat-treat the solids at 150℃ for 4 hours to obtain the dual-function drinking water filter carbon material.

[0035] A certain mass (m, g) of carbon material is added to a target solution with a volume of V and an initial concentration of C0 (target ions are Pb²⁺, Cd²⁺, Ca²⁺, or Mg²⁺). The solution is shaken at a constant temperature for 2 hours. After centrifugation or filtration, the equilibrium concentration C of the supernatant is measured. e Then, calculate the adsorption capacity, removal rate, and retention rate using the following formulas:

[0036] Adsorption capacity = (C0 - C) e )*V / m.

[0037] Removal rate = (C0 - C) e ) / C0*100%;

[0038] Retention rate = C e / C0*100%;

[0039] Where m=0.1g, V=100mL, and the initial concentrations C0 of each target ion are: Pb²⁺=75mg / L, Cd²⁺=35mg / L, Ca²⁺=80mg / L, and Mg²⁺=30mg / L.

[0040] According to the test results, the drinking water dual-function filter carbon material of this embodiment has an adsorption capacity of 70.0 mg / g for Pb²⁺ and a removal rate of 92.5%; an adsorption capacity of 32.5 mg / g for Cd²⁺ and a removal rate of 93.4%; a retention rate of 88.3% for Ca²⁺ and a retention rate of 86.4% for Mg²⁺.

[0041] Furthermore, the iodine value of the dual-function drinking water filter carbon material in this embodiment is 1053 mg / g, the methylene blue value is 391 mg / g, and the total specific surface area obtained by BET method is 1373.2 m². 2 / g, of which the microporous specific surface area is 974.2m². 2 / g, mesoporous specific surface area is 398.7m² 2 / g (accounting for 29.03%).

[0042] The coconut shell activated carbon purchased from Calgon Carbon Company has an iodine value of 1014 mg / g, a methylene blue value of 376 mg / g, and a total specific surface area of ​​975.0 m². 2 / g, with a microporous specific surface area of ​​814.0m². 2 / g, with a mesoporous specific surface area of ​​160.6m². 2 / g (accounting for 16.47%), the adsorption capacity for Pb²⁺ is 22 mg / g, the adsorption capacity for Cd²⁺ is 16 mg / g, the retention rate for Ca²⁺ is 37%, and the retention rate for Mg²⁺ is 18%.

[0043] Figure 1 This is a SEM image of the dual-function drinking water filtration carbon material in this embodiment. Figure 1 As shown, carbon materials have abundant pores.

[0044] Figure 2 This is the FT-IR spectrum of the dual-function drinking water filtration carbon material in this embodiment. Figure 2 As shown, approximately 1550cm -1 The characteristic NH peak appears at approximately 1450 cm⁻¹. -1 The -OCO- characteristic peak appears at this location. Example 2

[0045] Compared with Example 1, the preparation method of the drinking water dual-function filter carbon material in this example is different in that: in step (1), 10 parts by weight of urea is used as a pore-forming agent and 3 parts by weight of ferrous sulfate is used as a transition metal salt.

[0046] Testing revealed that the dual-function drinking water filtration carbon material in this embodiment effectively filters Pb. 2+ The adsorption capacity was 67.8 mg / g, and the removal rate was 89.5%; for Cd 2+ The adsorption capacity was 31.1 mg / g, and the removal rate was 89.4%; for Ca 2+ The retention rate was 86.5% for Mg. 2+ The retention rate was 84.2%. Example 3

[0047] Compared with Example 1, the preparation method of the drinking water dual-function filter carbon material in this example is different in that: in step (1), 5 parts by weight of melamine is used as a pore-forming agent and 1.5 parts by weight of copper chloride is used as a transition metal salt.

[0048] Testing revealed that the dual-function drinking water filtration carbon material in this embodiment effectively filters Pb. 2+ The adsorption capacity was 66.5 mg / g, and the removal rate was 87.9%; for Cd 2+The adsorption capacity was 30.4 mg / g, and the removal rate was 87.3%; for Ca 2+ The retention rate was 85.9% for Mg. 2+ The retention rate was 83.5%. Example 4

[0049] Compared with Example 1, the preparation method of the drinking water dual-function filter carbon material in this example is different in that: in step (2), the second stage is to introduce a water vapor mixture containing 5 vol% air for 10 minutes.

[0050] Testing revealed that the dual-function drinking water filtration carbon material in this embodiment effectively filters Pb. 2+ The adsorption capacity was 66.2 mg / g, and the removal rate was 84.8%; for Cd 2+ The adsorption capacity was 29.2 mg / g, and the removal rate was 83.8%; for Ca 2+ The retention rate was 84.1% for Mg. 2+ The retention rate was 81.2%. Example 5

[0051] Compared with Example 1, the preparation method of the drinking water dual-function filter carbon material in this example is different in that: in step (2), the second stage is to introduce a water vapor mixture containing 10 vol% air for 2 minutes.

[0052] Testing revealed that the dual-function drinking water filtration carbon material in this embodiment effectively filters Pb. 2+ The adsorption capacity was 65.1 mg / g, and the removal rate was 86.2%; for Cd 2+ The adsorption capacity was 29.8 mg / g, and the removal rate was 85.6%; for Ca 2+ The retention rate was 84.8%, for Mg 2+ The retention rate was 82.1%. Example 6

[0053] Compared with Example 1, the preparation method of the drinking water dual-function filter carbon material in this example is different in that: in step (4), the porous oxide carrier is heated to 120°C.

[0054] Testing revealed that the dual-function drinking water filtration carbon material in this embodiment effectively filters Pb. 2+ The adsorption capacity was 62.5 mg / g, and the removal rate was 82.6%; for Cd 2+ The adsorption capacity was 28.5 mg / g, and the removal rate was 81.8%; for Ca 2+ The retention rate was 81.5% for Mg. 2+ The retention rate was 78.6%. Example 7

[0055] Compared with Example 1, the preparation method of the drinking water dual-function filter carbon material in this example is different in that: in step (4), after the solid is separated, the solid is placed at 120°C for 8 hours of heat treatment.

[0056] Testing revealed that the dual-function drinking water filtration carbon material in this embodiment effectively filters Pb. 2+ The adsorption capacity was 59.8 mg / g, and the removal rate was 79.1%; for Cd 2+ The adsorption capacity was 27.2 mg / g, and the removal rate was 78.2%; for Ca 2+ The retention rate was 79.2% for Mg. 2+ The retention rate was 76.4%.

[0057] Compare with Example 1

[0058] Compared with Example 1, the difference in the preparation method of the drinking water filter carbon material in this comparative example is that transition metal salts were not used in step (1).

[0059] Tests showed that the drinking water filter carbon material in this control example was effective against Pb. 2+ The adsorption capacity was 52.4 mg / g, and the removal rate was 69.3%; for Cd 2+ The adsorption capacity was 23.8 mg / g, and the removal rate was 68.4%; for Ca... 2+ The retention rate was 78.5% for Mg. 2+ The retention rate was 76.2%.

[0060] Compare with Example 2

[0061] Compared with Example 1, the preparation method of drinking water filter carbon material in this comparative example is different in that: in step (2), thermal activation is only carried out in the first stage and not in the second stage.

[0062] Tests showed that the drinking water filter carbon material in this control example was effective against Pb. 2+ The adsorption capacity was 61.2 mg / g, and the removal rate was 80.9%; for Cd 2+ The adsorption capacity was 28.4 mg / g, and the removal rate was 80.7%; for Ca 2+ The retention rate was 83.4%, for Mg 2+ The retention rate was 81.5%.

[0063] Compare with Example 3

[0064] Compared with Example 1, the preparation method of the drinking water filter carbon material in this comparative example is different in that: in step (4), the porous oxide carrier at room temperature is immersed in an alkaline polyamine modified solution.

[0065] Tests showed that the drinking water filter carbon material in this control example was effective against Pb.2+ The adsorption capacity was 58.2 mg / g, and the removal rate was 76.8%; for Cd 2+ The adsorption capacity was 26.8 mg / g, and the removal rate was 76.9%; for Ca 2+ The retention rate was 75.4%, for Mg 2+ The retention rate was 72.6%.

[0066] Compare with Example 4

[0067] Compared with Example 1, the preparation method of the drinking water filter carbon material in this comparative example is different in that: in step (4), after solid-liquid separation, it is dried at 70°C for 12 hours.

[0068] Tests showed that the drinking water filter carbon material in this control example was effective against Pb. 2+ The adsorption capacity was 51.5 mg / g, and the removal rate was 68.1%; for Cd 2+ The adsorption capacity was 23.6 mg / g, and the removal rate was 67.8%; for Ca 2+ The retention rate was 68.5% for Mg. 2+ The retention rate was 65.2%.

[0069] The embodiments of the drinking water dual-function filtration carbon material of the present invention are prepared by the preparation method described in any of the above embodiments.

[0070] An embodiment of the drinking water purification element of the present invention is a drinking water dual-function filter carbon material prepared by the preparation method described in any of the above embodiments, which may be, but is not limited to, any one of the following: filter membrane structure, filled column structure, rolled structure, and pleated structure.

[0071] The embodiments of the invention provided in this specification have been described above. Those skilled in the art will be able to implement the embodiments of the invention provided in this specification based on these descriptions. All other preferred embodiments and implementations obtained by those skilled in the art based on the above description of the embodiments of the invention provided in this specification without inventive effort should fall within the protection scope of the embodiments of the invention provided in this specification.

Claims

1. A method for preparing a dual-function carbon material for drinking water filtration, characterized in that, Includes the following steps: (1) The primary carbonized material, binder, pore-forming agent and transition metal salt solution are mixed and kneaded into shape, and then dried to obtain a green body; (2) The green body is subjected to secondary carbonization and thermal activation treatment in sequence, cooled and washed with water until the conductivity of the washing liquid is constant, and dried to obtain a porous carrier; (3) The porous support is immersed in the oxidation modification solution, and after solid-liquid separation, it is washed with water and dried to obtain the porous oxidation support; (4) The hot porous oxide carrier is immersed in an alkaline polyamine modified solution. The temperature of the porous oxide carrier is higher than that of the alkaline polyamine modified solution. When the temperature is cooled to room temperature, the pH of the mixture is adjusted to be close to neutral. After solid-liquid separation, heat treatment is performed to obtain a dual-function filter carbon material for drinking water.

2. The preparation method according to claim 1, characterized in that: In step (1), the primary carbonization material is prepared by heating bamboo powder, coconut shell, apricot shell or walnut shell at 450-600℃ in an inert atmosphere for 1-3 hours; the binder is at least one of coal tar, phenolic resin, carboxymethyl cellulose and starch; the pore-forming agent is at least one of ammonium bicarbonate, urea and melamine; the transition metal salt is at least one of ferric chloride, ferrous sulfate, ferric nitrate, copper chloride and copper sulfate.

3. The preparation method according to claim 2, characterized in that: In step (1), the mass ratio of primary carbonized material, binder, pore-forming agent and transition metal salt is 100:(30-40):(5-10):(1.5-3); the kneading aid is water.

4. The preparation method according to claim 1, characterized in that: In step (2), the secondary carbonization process involves holding the material at 500-700℃ in an inert atmosphere for 1-2 hours.

5. The preparation method according to claim 1, characterized in that: In step (2), the thermal activation treatment includes two stages. The first stage is to keep the mixture at 850-950℃ in a water vapor atmosphere for 1-3 hours. The second stage is to introduce a mixture of water vapor and air and continue to keep the mixture at 850-950℃ for 2-10 minutes. The volume fraction of air in the mixture is 5-10 vol.

6. The preparation method according to claim 1, characterized in that: In step (3), the oxidation modification solution is a hydrogen peroxide solution with a mass fraction of 10-20%, and the solid-liquid ratio of the porous carrier to the oxidation modification solution is 1g:(20-40)mL, and it is immersed at 30-50℃ for 4-6 hours.

7. The preparation method according to claim 1, characterized in that: In step (4), the polyamine modification solution is an aqueous solution of branched polyethyleneimine with a mass concentration of 5-12%, a pH of 10-12, and a temperature of 30-50℃, and the weight-average molecular weight of the branched polyethyleneimine is 25,000-70,000; the temperature of the porous oxidation support is 120-140℃; and the solid-liquid ratio of the porous oxidation support to the polyamine modification solution is 1g:(20-40)mL.

8. The preparation method according to claim 7, characterized in that: In step (4), 0.5-2.0 mol / L hydrochloric acid solution is added dropwise to the mixture until the pH value is 6.5-7.

5. Then, the mixture is allowed to stand and age for 2-4 hours at this pH value before solid-liquid separation is performed. The heat treatment temperature is 120-150℃ and the heat treatment time is 4-8 hours.

9. A dual-function carbon filter material for drinking water, characterized in that: It is prepared by the preparation method according to any one of claims 1-8.

10. A drinking water purification element, characterized in that: The drinking water dual-function filter carbon material prepared by the preparation method according to any one of claims 1-8.

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