A charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas, its preparation method and application
By preparing charged adsorption materials and combining them with a composite structure of carbon nanotubes and TiO2 nanoparticles, we have achieved synergistic treatment of multiple pollutants in the high temperature and complex airflow environment of coalfield fire areas. This solves the problems of stability and adsorption capacity of traditional materials in extreme environments and provides a long-lasting solution for pollutant degradation and adsorption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA UNIV OF MINING & TECH
- Filing Date
- 2025-11-25
- Publication Date
- 2026-06-30
AI Technical Summary
In existing coalfield fire zone pollution control technologies, adsorption materials are unstable under high temperature and complex environments, have limited adsorption capacity, and cannot effectively degrade pollutants, resulting in short-term and unsustainable control effects.
By employing charged adsorption materials, amino-modified carbon nanotube electrodes and negatively charged TiO2 nanoparticle composite materials are prepared. Utilizing electrostatic adsorption and photocatalytic degradation functions, these materials can operate stably in high-temperature and complex airflow environments, achieving synergistic treatment of heavy metal ions and coal tar.
The material maintains stable adsorption capacity and degradation effect in high temperature and complex airflow environments, and can efficiently adsorb heavy metal ions and coal tar, providing a long-lasting pollution control solution and significantly improving the efficiency and sustainability of the treatment.
Smart Images
Figure CN121372332B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of environmental pollution control technology in coalfield fire areas, specifically to a charged adsorption material for the synergistic treatment of multiple pollutants in coalfield fire areas, its preparation method, and its application. Background Technology
[0002] Coalfield fire zones are widely distributed in the arid open-pit coalfields of Northwest my country, and coalfield fires typically lead to severe pollution and safety hazards. Harmful substances such as coal tar, sulfides, and heavy metals pose a significant threat to the environment and human health during combustion and diffusion in coalfield fire zones. Currently, common methods for controlling pollution in coalfield fire zones include chemical adsorption and physical adsorption technologies. While these technologies can remove harmful pollutants to some extent, the adsorbent materials cannot further degrade pollutants after adsorption saturation. Furthermore, traditional adsorbents have limited adsorption capacity and are prone to failure under high temperatures or complex environmental conditions. Some existing materials are unstable in the high-temperature and complex airflow environments of coalfield fire zones, resulting in short-term and unsustainable control effects. Therefore, there is an urgent need for a new type of material capable of achieving efficient adsorption in extreme environments and long-term pollution control through catalytic degradation. Summary of the Invention
[0003] The purpose of this invention is to provide a multifunctional charged adsorption material for pollution control in coalfield fire areas, its preparation method, and its application. This material can work stably in the complex high-temperature and airflow environment of coalfield fire areas. The prepared composite material has good adsorption performance, photocatalytic degradation function, and long-lasting pollution control effect. It can simultaneously and efficiently adsorb heavy metal ions and organic pollutants such as coal tar, and has good environmental adaptability, long-term effectiveness, and stability. It is suitable for the synergistic treatment of multiple pollutants such as heavy metal pollution and coal tar pollution in coalfield fire areas.
[0004] To achieve the above objectives, the present invention is implemented through the following technical solution: a method for preparing charged adsorption materials for the synergistic treatment of multiple pollutants in coalfield fire areas, comprising the following steps:
[0005] S1. Preparation of amino-modified carbon nanotube electrodes;
[0006] S1-1. Carbon nanotubes are added to concentrated nitric acid aqueous solution and stirred at room temperature for 2-4 hours. After the reaction is completed, the carbon nanotubes are washed with deionized water until neutral and then dried to obtain oxidized carbon nanotubes. The oxidized carbon nanotubes are added to APTES ethanol solution with pH 4.5-5.5 and stirred at 60-80℃ for 1-3 hours. After the reaction is completed, the unreacted APTES is washed with ethanol and dried to obtain amino-modified carbon nanotubes.
[0007] S1-2. The amino-modified carbon nanotubes obtained in step S1-1 are uniformly coated onto the conductive carbon paper electrode substrate using conductive adhesive. After drying and curing, a stable electrode surface is formed, thus obtaining an amino-modified carbon nanotube electrode.
[0008] S2. Preparation of electrolyte modified with charged adsorption materials;
[0009] S2-1. TiO2 nanoparticles were added to deionized water and ultrasonically dispersed to obtain a TiO2 nanoparticle dispersion. Then, 3-trihydroxysilylpropylmethylphosphonic acid (THPMP) ethanol solution was added, and the pH of the solution was adjusted to 4-5. The mixture was stirred and reacted. After the reaction was completed, the mixture was washed with deionized water and dried to obtain THPMP-modified TiO2 nanoparticles.
[0010] S2-2. Dissolve the THPMP-modified TiO2 nanoparticles obtained in step S2-1 in deionized water and adjust the pH value to 8-9 for deprotonation treatment. After the reaction is complete, wash the unreacted THPMP with deionized water and dry to obtain negatively charged modified TiO2 nanoparticles.
[0011] S2-3. Add the negatively charged TiO2 nanoparticles obtained in step S2-2 and Na2SO4 to deionized water to prepare a charged adsorption material modified electrolyte.
[0012] S3. Immerse the amino-modified carbon nanotube electrode obtained in step S1 into an electrolytic cell containing the electrolyte solution modified with the charged adsorption material prepared in step S2. Electroplating is used to uniformly deposit negatively charged TiO2 nanoparticles on the surface of the amino-modified carbon nanotube electrode. After electroplating, the electrode is cleaned with deionized water to remove undeposited TiO2 nanoparticles. The electroplated electrode material is dried to obtain the TiO2-negatively charged modified carbon nanotube electrode.
[0013] S4. After crushing the TiO2-negatively charged carbon nanotube electrode obtained in step S3, place it in a vacuum oven with an initial temperature of 100°C and keep it at that temperature for 20-30 minutes. Then gradually increase the temperature to 180°C and keep it at that temperature for 30-60 minutes. After heating, slowly cool it to room temperature, wash it with deionized water, and dry it naturally at room temperature to obtain the charged adsorption material.
[0014] Preferably, in step S1-1, the mass ratio between carbon nanotubes and concentrated nitric acid aqueous solution is 1:(1-5); the mass fraction of concentrated nitric acid aqueous solution is 70%; the volume fraction of APTES in APTES ethanol solution is 1%; the mass-volume ratio of carbon nanotubes to APTES ethanol solution is 1g:20ml; and the solution is dried in a vacuum oven at 60°C for 2-4 hours.
[0015] Preferably, in steps S1-2, the amount of conductive adhesive applied is 0.03-0.1 mL / cm². 2 Dry at 60℃ for 30-60 minutes.
[0016] Preferably, in step S2-1, the particle size range of TiO2 nanoparticles is 20-50 nm, the concentration of TiO2 nanoparticle dispersion is 0.03-0.1 g / ml; the concentration of THPMP in the THPMP ethanol solution is 0.01-0.015 g / ml; the mass ratio between TiO2 nanoparticles and THPMP is (20-50):1; drying is performed in a vacuum oven at 60°C; the ultrasonic power is 50-100 W, and the frequency range is 20-40 kHz.
[0017] Preferably, in step S2-2, the pH value is adjusted using a 0.05-0.1M NaOH solution; and the product is dried at 60°C for 4-6 hours.
[0018] Preferably, in steps S2-3, the concentrations of the negatively charged modified TiO2 nanoparticles and Na2SO4 in the electrolyte modified with the charged adsorption material are 0.02 g / ml and 0.5 mg / ml, respectively.
[0019] Preferably, in step S3, the current density of the electrolytic cell is in the range of 1-5 mA / cm². 2 Electroplating time is controlled between 10 and 25 minutes; dry in a vacuum oven at 60°C.
[0020] Preferably, in step S4, the heating rate of the vacuum oven is 2-5℃ / min.
[0021] To achieve the above objectives, the present invention also provides charged adsorption materials prepared by the above preparation method for the synergistic treatment of multiple pollutants in coalfield fire areas.
[0022] To achieve the above objectives, the present invention also provides the application of the charged adsorption material prepared by the above preparation method in the synergistic treatment of multiple pollutants in coalfield fire areas. The specific application process is as follows: the charged adsorption material is sprayed onto the target fire area using coalfield fire area cooling materials (such as mud, foam, etc.) as carriers, or it can be evenly sprayed inside and around the pit opening without waiting for cooling after the fire source is excavated and moved, ensuring that the charged adsorption material is in full contact with the coal fire front and efficiently adsorbs the tar and free heavy metals generated in the coalfield fire area.
[0023] The remediation mechanism of this invention: The multifunctional charged adsorption material prepared in this invention uses charged electroplating technology to uniformly deposit TiO2 nanoparticles on the surface of amino-modified carbon nanotubes, forming a TiO2-negatively charged modified carbon nanotube composite material, which plays a role in the remediation of coalfield fire pollution. Under the action of this material, the negative charge on the TiO2 surface reacts with heavy metal ions (such as Pb) in the coalfield fire area.2 ⁺、Cu 2 Electrostatic adsorption occurs between TiO2 and other organic pollutants such as coal tar, which are then synergistically degraded. Simultaneously, the photocatalytic effect of TiO2 is activated under ultraviolet light irradiation, generating hydroxyl radicals and superoxide radicals that effectively degrade aromatic hydrocarbons in coal tar, reducing pollutant residues.
[0024] The composite material prepared in this invention combines TiO2 nanoparticles with carbon nanotubes, integrating photocatalytic degradation and charge adsorption mechanisms to achieve highly efficient synergistic treatment of heavy metal ions and organic pollutants such as coal tar in the complex environment of coalfield fire zones. This material maintains stable adsorption capacity and degradation effect under high temperature and high gas flow conditions, while its porous structure provides abundant adsorption sites, enhancing its adaptability and long-term stability. Through the photocatalytic reaction of TiO2 and the charge modification of carbon nanotubes, this invention achieves synergistic treatment of multiple pollutants in coalfield fire zones and solves the problem of performance degradation of traditional adsorption materials in high temperature and high gas flow environments, significantly improving the efficiency and sustainability of pollution control.
[0025] Compared with the prior art, the present invention has the following beneficial effects:
[0026] 1. The TiO2 nanoparticles on the surface of the material of this invention, through negative charge modification, interact with heavy metal cations in coalfield fire zones via electrostatic adsorption, forming a stable adsorption complex and significantly improving the adsorption capacity for heavy metals. Carbon nanotubes, as the framework of the material, provide a porous structure and abundant surface active sites, enhancing the material's adsorption capacity for organic pollutants. Simultaneously, the negative charge on the TiO2 surface gives it a higher affinity for pollutants, thereby achieving synergistic treatment of multiple pollutants and providing an efficient and durable pollution control solution.
[0027] 2. The charged adsorption material prepared in this invention adopts a composite structure of TiO2 nanoparticles and carbon nanotubes, possessing dual functions of adsorption and photocatalytic degradation. After adsorption saturation, the TiO2 nanoparticles of the material can activate their photocatalytic performance under ultraviolet light irradiation, generating hydroxyl radicals and superoxide radicals. These strong oxidants can rapidly degrade the organic components in coal tar, converting them into harmless small molecules such as CO2 and H2O, effectively avoiding the long-term accumulation of pollutants during the adsorption process, ensuring the continuous degradation and long-term adsorption of pollutants, and providing a long-term stable pollution control solution.
[0028] 3. This invention utilizes carbon nanotubes as a framework to provide thermally stable porous channels and high charge density, ensuring sufficient active sites and continuous adsorption capacity even under high temperatures and turbulent airflow. Negatively charged TiO2, obtained through electroplating, is uniformly deposited and firmly adhered to the surface of amino-modified carbon nanotubes. Subsequent vacuum heat treatment stabilizes the interface and improves the density of the thin layer, thereby preventing coating detachment and deactivation during thermal cycling and airflow shearing. In complex airflows, the material captures pollutants through a combination of electrostatic attraction and chemical modification. Its adsorption performance is insensitive to flow directionality and does not significantly decrease due to environmental disturbances.
[0029] In summary, the charged adsorption material prepared in this invention not only possesses excellent adsorption performance but also incorporates photocatalytic degradation capabilities, enabling it to operate continuously in the high-temperature and complex airflow environments of coalfield fire zones. By modifying the carbon nanotube composite material with TiO2-negative charge, this invention can simultaneously adsorb pollutants and activate their photocatalytic activity using ultraviolet light irradiation, effectively degrading organic pollutants in coal tar and reducing secondary release of pollutants. Furthermore, this material can also simultaneously adsorb heavy metal ions in coalfield fire zones, providing a synergistic treatment solution for multiple pollutants, significantly improving treatment effectiveness, and offering a new technical route for environmental remediation in coalfield fire zones. Attached Figure Description
[0030] Figure 1 Images of the surface Zeta potential of the charged adsorption materials prepared in Examples 1-3 under different pH conditions;
[0031] Figure 2 The UV-Vis absorption spectra of the charged adsorption materials prepared in Examples 1-3 under catalytic degradation under 250 nm wavelength light are shown.
[0032] Figure 3 The UV-Vis absorption spectra of the charged adsorption materials prepared in Examples 1-3 under catalytic degradation under 300 nm wavelength light are shown.
[0033] Figure 4 The UV-Vis absorption spectra of the charged adsorption materials prepared in Examples 1-3 under catalytic degradation under 350 nm wavelength light are shown.
[0034] Figure 5 The bar chart shows the changes in tar adsorption performance of the charged adsorption materials prepared in Examples 1, 3, and 4 at different adsorption times.
[0035] Figure 6 The bar chart shows the changes in tar adsorption performance of the charged adsorption materials prepared in Examples 1, 3, and 4 under different high-temperature environments. Detailed Implementation
[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0037] Example 1
[0038] A method for preparing a charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas includes the following steps:
[0039] S1. Preparation of amino-modified carbon nanotube electrodes;
[0040] S1-1. Weigh 3g of carbon nanotubes and add them to 10.5ml of 70% concentrated nitric acid aqueous solution. Stir and react at room temperature for 4 hours. After the reaction is complete, wash with deionized water until neutral and dry to obtain oxidized carbon nanotubes. Add the oxidized carbon nanotubes to 60ml of 1% (v / v) 3-aminopropyltriethoxysilane (APTES) ethanol solution with pH 4.5-5.5 and heat and stir in an oil bath at 60℃ for 2 hours to ensure that APTES is uniformly attached to the surface of the carbon nanotubes. After the reaction is complete, wash the unreacted APTES with ethanol and dry in a vacuum oven at 60℃ for 4 hours to obtain amino-modified carbon nanotubes.
[0041] S1-2. The amino-modified carbon nanotubes obtained in step S1-1 are uniformly coated onto a conductive carbon paper electrode substrate using conductive adhesive. The coating amount of conductive adhesive is 0.05 mL / cm². 2 To ensure that the carbon nanotubes are uniformly coated and firmly adhered to the surface of the conductive carbon paper, the coated electrode material is dried at 60°C for 30 minutes to ensure that the conductive adhesive is completely cured and a stable electrode surface is formed, thus obtaining an amino-modified carbon nanotube electrode.
[0042] S2. Preparation of electrolyte modified with charged adsorption materials;
[0043] S2-1. Add 3g of TiO2 nanoparticles to 60ml of deionized water and sonicate for 15 minutes at 100W and 30kHz to obtain a TiO2 nanoparticle dispersion. Weigh 0.12g of THPMP, dissolve it in 10mL of ethanol, and slowly add it to the above TiO2 nanoparticle dispersion. Add nitric acid to adjust the pH of the solution to 4-5 and stir the reaction. After the reaction is complete, wash with deionized water and dry in a vacuum oven at 60°C to obtain THPMP-modified TiO2 nanoparticles.
[0044] S2-2. The THPMP-modified TiO2 nanoparticles obtained in S2-1 were dissolved in 50 mL of deionized water, and 0.1 M NaOH solution was added to adjust the pH value to 8-9 for deprotonation treatment. After the reaction was completed, the unreacted THPMP was washed with deionized water and dried at 60°C for 4 h to obtain negatively charged modified TiO2 nanoparticles.
[0045] S2-3. Add 3g of negatively charged modified TiO2 nanoparticles obtained in step S2-2 and 0.075g of Na2SO4 to 150ml of deionized water to prepare a charged adsorption material modified electrolyte.
[0046] S3. Immerse the amino-modified carbon nanotube electrode obtained in step S1 into an electrolytic cell containing the charged adsorption material-modified electrolyte prepared in step S2, and apply an A / cm² pressure to the electrolytic cell. 2 At a current density of 15 minutes, electroplating was performed to uniformly deposit negatively charged TiO2 nanoparticles onto the surface of the amino-modified carbon nanotube electrode. After electroplating, the electrode was cleaned with deionized water to remove undeposited TiO2 nanoparticles, ensuring that the TiO2 nanoparticles were firmly attached to the carbon nanotube surface. The electroplated electrode material was then dried in a vacuum oven at 60°C to obtain the TiO2-negatively charged carbon nanotube electrode.
[0047] S4. After crushing the TiO2-negatively charged carbon nanotube electrode obtained in step S3, place it in a vacuum oven with an initial temperature of 100°C and keep it at that temperature for 20-30 minutes. Then gradually increase the temperature to 180°C and keep it at that temperature for 30-60 minutes. After heating, slowly cool it to room temperature, wash it with deionized water, and dry it naturally at room temperature to obtain the charged adsorption material.
[0048] Example 2
[0049] The preparation method in this embodiment differs from that in Example 1 in that: in this embodiment, the amounts of TiO2 nanoparticles, THPMP, and ethanol used in step S2-1 are 6g, 0.24g, and 18ml, respectively; and in step S3, the electrolytic cell is subjected to an application of 5mA / cm 2 The current density was adjusted, the electroplating time was changed to 25 minutes, and the rest of the process and parameters remained the same as in Example 1.
[0050] Example 3
[0051] The preparation method in this embodiment differs from that in Example 1 in that: in step S1-1, the amounts of carbon nanotubes and concentrated nitric acid solution used are 4g and 14ml, respectively; in step S2-1, the amounts of TiO2 nanoparticles, THPMP, and ethanol used are 2g, 0.08g, and 8ml, respectively; and in step S3, an electrolytic cell is subjected to an application rate of 2.5mA / cm. 2 The current density was adjusted, the electroplating time was changed to 10 minutes, and the rest of the process and parameters remained the same as in Example 1.
[0052] Example 4
[0053] The preparation method in this embodiment differs from that in Example 1 in that: in this embodiment, the amounts of TiO2 nanoparticles, THPMP, and ethanol used in step S2-1 are 6g, 0.24g, and 16.8ml, respectively; and in step S3, the electrolytic cell is subjected to an application rate of 4mA / cm. 2 The current density was adjusted, the electroplating time was changed to 25 minutes, and the rest of the process and parameters remained the same as in Example 1.
[0054] The surface potential of the charged adsorption materials prepared in Examples 1-3 was measured by simulating different pH environments in a coalfield fire zone. The Zeta potential images are shown below. Figure 1 As shown in the figure, Example 1 exhibits a relatively stable negative potential. With the increase of TiO2 ratio and the extension of electroplating time, the surface negative potential of Example 2 is stronger, which can adsorb more heavy metal ion pollutants. In Example 3, the amount of TiO2 and the electroplating time are appropriately reduced. With the increase of pH, the potential change trend is weaker, and the overall potential is higher than that of Examples 1-2, but it still maintains a negative potential and has an electrostatic attraction effect on positively charged pollutants.
[0055] The catalytic degradation effect of the charged adsorption materials prepared in Examples 1-3 under different wavelengths of light was measured using a UV-Vis spectrophotometer. The results are as follows: Figure 2-4As shown, under illumination at wavelengths of 250 nm, 300 nm, and 350 nm, Example 2 exhibited the strongest photocatalytic degradation performance, with absorbance decreasing rapidly over time, reaching a minimum at 60 minutes. This indicates that a higher TiO2 dosage provides more photocatalytic active sites, while a longer electroplating time ensures that TiO2 nanoparticles can be deposited more uniformly on the carbon nanotube surface, thereby improving the catalytic efficiency of the material. TiO2, as a widely used photocatalyst, can effectively excite electron-hole pairs under ultraviolet light irradiation, thereby generating strong oxidizing free radicals and promoting the degradation of pollutants. In Example 2, due to the more sufficient negative charge modification of TiO2, it can degrade adsorbed pollutants into harmless substances more quickly and effectively while adsorbing them. In contrast, Example 1 exhibited more moderate photocatalytic degradation performance, with a more gradual decrease in absorbance and a moderate change in absorbance at 60 minutes. This indicates that a lower TiO2 dosage and shorter electroplating time tend to result in fewer photocatalytic active sites, thus limiting the rate and efficiency of the degradation reaction. Nevertheless, Example 1 still provides a relatively balanced effect in environments with less stringent degradation requirements, making it suitable for applications with mild pollution or mild degradation requirements. Example 3, due to its lower TiO2 content, exhibits a slower decrease in absorbance, demonstrating a weaker photocatalytic effect. Its absorbance at 60 minutes is significantly lower than that of Examples 1 and 2, indicating limited catalytic degradation ability. This shows that in materials modified with negatively charged TiO2, the amount of TiO2 directly affects the material's photocatalytic degradation performance. Example 3 is suitable for applications where adsorption is dominant and photocatalysis is weak, such as treating lightly polluted environments or those with low requirements for photocatalytic degradation. However, due to the limited TiO2 surface modification, the material in Example 3 primarily relies on adsorption rather than photocatalytic degradation, resulting in limited degradation efficiency for pollutants.
[0056] The adsorption performance of charged adsorption materials for tar was determined by high performance liquid chromatography (HPLC). The adsorption amounts of multiple components in tar were calculated and summarized using the following formula:
[0057]
[0058]
[0059] Where Q is the adsorption amount of the i-th component, mg / g; C i0 C represents the concentration of the i-th component before adsorption, in mg / L. i1 denoted as , where is the concentration of the i-th component after adsorption (mg / L); V is the volume of the tar solution (L); and m is the mass of the adsorbent material (g).
[0060] according to Figure 1 and Figure 2 Data analysis shows that the charged adsorption materials prepared in Examples 1, 3, and 4 exhibit different characteristics in tar adsorption performance. Figure 5 Among the samples, Example 3 exhibited the highest adsorption performance, with its adsorption capacity increasing significantly over time, especially rapidly in the first 30 minutes, indicating that the material has a strong adsorption rate and is suitable for highly polluted environments. Example 1 showed a relatively stable increase in adsorption capacity, with the adsorption capacity gradually increasing, indicating that its adsorption performance is relatively balanced and suitable for environments with moderate pollution concentrations. Example 4 showed a slower increase in adsorption capacity and a lower adsorption capacity, indicating that its adsorption performance is weaker and suitable for environments with low concentrations of pollution.
[0061] exist Figure 6 In the three embodiments, the adsorption performance gradually decreased with increasing temperature. However, Examples 1 and 4 maintained strong adsorption capacity at high temperatures, especially Example 4, which maintained an adsorption capacity of 0.06 mg / g even at 600°C, demonstrating good high-temperature stability. Example 1 showed a decrease in adsorption capacity from 0.18 mg / g at 300°C to 0.05 mg / g at 600°C, but still maintained a certain adsorption effect at 600°C, demonstrating strong high-temperature resistance. In contrast, the adsorption capacity of Example 3 decreased rapidly at high temperatures, from 0.12 mg / g at 300°C to 0.03 mg / g at 600°C, exhibiting weaker high-temperature resistance and making it suitable for low-temperature or low-pollution concentration environments. In summary, the charged adsorption material of this invention still possesses a certain adsorption capacity under high-temperature conditions, especially Examples 1 and 4, demonstrating its high-temperature resistance and long-term stability in complex environments such as coalfield fire zones, making it suitable for high-temperature pollution control. Example 2 demonstrates that in environments with high pollution concentrations, the material can rapidly adsorb tar and perform photocatalytic degradation, making it suitable for short-term treatment of high-concentration pollution.
[0062] Therefore, charged adsorption materials for the synergistic treatment of multiple pollutant types in coalfield fire areas can exhibit different adsorption properties and photocatalytic degradation capabilities by adjusting the material preparation method and ratio, thus adapting to the treatment needs of different pollutants in complex environments such as coalfield fire areas. By optimizing the amount of TiO2, electroplating time, and the degree of surface modification of carbon nanotubes, the material can maintain strong adsorption capacity at high temperatures, especially showing excellent results in treating coal tar and heavy metal pollution. Therefore, the material of this invention can not only efficiently adsorb pollutants such as coal tar, but also achieve long-term pollution control at high temperatures, ensuring the long-term removal effect of pollutants in coalfield fire areas and improving the environmental safety and treatment efficiency of coalfield fire areas.
Claims
1. A method for preparing charged adsorption materials for synergistic treatment of multiple pollutants in coalfield fire areas, characterized in that, Includes the following steps: S1: Preparation of amino-modified carbon nanotube electrodes; S1-1: Add carbon nanotubes to concentrated nitric acid aqueous solution and stir at room temperature for 2-4 hours. After the reaction is completed, wash with deionized water until neutral and dry to obtain oxidized carbon nanotubes. Add the oxidized carbon nanotubes to APTES ethanol solution with pH 4.5-5.5 and stir at 60-80℃ for 1-3 hours. After the reaction is completed, wash the unreacted APTES with ethanol and dry to obtain amino-modified carbon nanotubes. S1-2: The amino-modified carbon nanotubes obtained in step S1-1 are uniformly coated onto the conductive carbon paper electrode substrate using conductive adhesive. After drying and curing, a stable electrode surface is formed, resulting in an amino-modified carbon nanotube electrode. S2: Preparation of electrolyte modified with charged adsorption materials; S2-1: TiO2 nanoparticles were added to deionized water and ultrasonically dispersed to obtain a TiO2 nanoparticle dispersion. Then, 3-trihydroxysilylpropylmethylphosphonic acid ethanol solution was added, and the pH of the solution was adjusted to 4-5. The mixture was stirred and reacted. After the reaction was completed, the mixture was washed with deionized water and dried to obtain 3-trihydroxysilylpropylmethylphosphonic acid modified TiO2 nanoparticles. S2-2: The TiO2 nanoparticles modified with 3-trihydroxysilylpropylmethylphosphonic acid obtained in step S2-1 were dissolved in deionized water, and the pH value was adjusted to 8-9 for deprotonation treatment. After the reaction was completed, the unreacted 3-trihydroxysilylpropylmethylphosphonic acid was washed with deionized water and dried to obtain negatively charged modified TiO2 nanoparticles. S2-3: Add the negatively charged TiO2 nanoparticles obtained in step S2-2 and Na2SO4 to deionized water to prepare a charged adsorption material modified electrolyte. S3: Immerse the amino-modified carbon nanotube electrode obtained in step S1 into an electrolytic cell containing the electrolyte solution modified with the charged adsorption material prepared in step S2. Electroplating is used to uniformly deposit negatively charged TiO2 nanoparticles on the surface of the amino-modified carbon nanotube electrode. After electroplating, the electrode is cleaned with deionized water to remove undeposited TiO2 nanoparticles. After drying the electroplated electrode material, a TiO2-negatively charged modified carbon nanotube electrode is obtained. S4: After crushing the TiO2-negatively charged carbon nanotube electrode obtained in step S3, place it in a vacuum oven with an initial temperature of 100°C and keep it at that temperature for 20-30 minutes. Then gradually increase the temperature to 180°C and keep it at that temperature for 30-60 minutes. After heating, slowly cool it to room temperature, wash it with deionized water, and dry it naturally at room temperature to obtain the charged adsorption material.
2. The method for preparing a charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas according to claim 1, characterized in that, In step S1-1, the mass ratio of carbon nanotubes to concentrated nitric acid aqueous solution is 1:(1-5); the mass fraction of concentrated nitric acid aqueous solution is 70%; the volume fraction of APTES in APTES ethanol solution is 1%; the mass-volume ratio of carbon nanotubes to APTES ethanol solution is 1g:20ml; and the solution is dried in a vacuum oven at 60℃ for 2-4 hours.
3. A method for preparing a charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas according to claim 1, characterized in that, The conductive paste was applied in an amount of 0.03-0.1 mL / cm in step S1-2 2 Drying was performed at 60°C for 30-60 minutes.
4. A method for preparing a charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas according to claim 1, characterized in that, In step S2-1, the particle size of TiO2 nanoparticles ranges from 20 to 50 nm, and the concentration of the TiO2 nanoparticle dispersion is 0.03 to 0.1 g / ml; in the ethanol solution of 3-trihydroxysilylpropylmethylphosphonic acid, the concentration of 3-trihydroxysilylpropylmethylphosphonic acid is 0.01 to 0.015 g / ml; the mass ratio between TiO2 nanoparticles and 3-trihydroxysilylpropylmethylphosphonic acid is (20-50):1; drying is performed in a vacuum oven at 60°C; the ultrasonic power is 50-100 W, and the frequency range is 20-40 kHz.
5. A method for preparing a charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas according to claim 1, characterized in that, In step S2-2, the pH value is adjusted using a 0.05-0.1M NaOH solution; and the product is dried at 60°C for 4-6 hours.
6. A method for preparing a charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas according to claim 1, characterized in that, In steps S2-3, the concentrations of negatively charged modified TiO2 nanoparticles and Na2SO4 in the electrolyte modified with charged adsorption materials are 0.02 g / ml and 0.5 mg / ml, respectively.
7. A method for preparing a charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas according to claim 1, characterized in that, In step S3, the current density of the electrolytic cell is in the range of 1-5 mA / cm², and the electroplating time is controlled at 10-25 minutes; the product is then dried in a vacuum oven at 60°C.
8. A method for preparing a charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas according to claim 1, characterized in that, In step S4, the heating rate of the vacuum oven is 2-5℃ / min.
9. A charged adsorption material for synergistic treatment of multiple pollutants in coalfield fire areas, prepared by the preparation method according to any one of claims 1-8.
10. The application of the charged adsorption material as described in claim 9 in the synergistic treatment of multiple pollutants in coalfield fire areas, wherein the charged adsorption material is sprayed onto the target fire area using coalfield fire area cooling material as a carrier, or can be evenly sprayed inside and around the pit opening without waiting for cooling after the fire source is excavated and moved, so that the charged adsorption material can fully contact the coal fire front and efficiently adsorb tar and free heavy metals generated in the coalfield fire area; wherein the coalfield fire area cooling material is mud or foam.