A graded pore iron-manganese-microorganism composite functional material for rubber asphalt flue gas desulfurization
By using a graded channel design, an iron-manganese-microbial composite functional material is used to achieve a synergistic effect of catalytic oxidation and microbial degradation, which solves the problems of easy clogging and low efficiency of rubber asphalt flue gas desulfurization materials and achieves a high-efficiency and long-lasting flue gas purification effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HOHAI UNIV
- Filing Date
- 2026-04-08
- Publication Date
- 2026-06-30
AI Technical Summary
Existing rubber asphalt flue gas desulfurization materials are prone to clogging, have low desulfurization efficiency and poor stability, and cannot effectively treat high-temperature, high-oil-mist, multi-component sulfur-containing flue gas.
The hierarchical pore design employs micropores for loading iron-manganese bimetallic catalytic sites, mesopores for mass transfer, and macropores for microbial immobilization, achieving synergistic effects of catalytic oxidation and microbial degradation while avoiding micropore clogging.
It significantly improves desulfurization efficiency, with a sulfide removal rate of ≥80%, is suitable for high-temperature working conditions of rubber asphalt flue gas, has a stable material structure, and possesses long-lasting and anti-clogging properties.
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Figure CN122298497A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of environmentally friendly asphalt technology, specifically relating to a graded porous iron-manganese-microorganism composite functional material for desulfurization of rubber asphalt flue gas. Background Technology
[0002] Tires, as solid waste, are increasing dramatically year by year with the rise in automobile production. Burning or stockpiling tires causes serious environmental pollution. Crushing them into rubber fragments to prepare rubber-modified asphalt is one of the effective methods for treating waste tires. It not only has significant environmental and socio-economic benefits but is also a key means of improving the performance of petroleum asphalt. However, using rubber in asphalt materials presents several problems, including poor mixability and processability, especially since rubber-modified asphalt requires more heat during production. Due to its high viscosity, rubber-modified asphalt requires a higher mixing and compaction temperature, 15-20°C higher than base asphalt. This increases the emission of greenhouse gases and odorous gases during production and use, mainly including volatile organic compounds (VOCs), hydrogen sulfide (H2S), sulfur dioxide (SO2), and nitrogen oxides (NOx). This not only harms human health but also damages environmental sustainability.
[0003] Currently, the functional materials used in the desulfurization process of rubber asphalt flue gas are mainly divided into single adsorbent materials, single catalytic materials, or single biological carrier materials, all of which have obvious defects: single adsorbent materials (such as activated carbon) are prone to clogging of adsorption channels by particulate matter, resulting in a rapid decrease in adsorption capacity and unstable desulfurization efficiency; single iron-manganese-based catalytic materials can quickly treat inorganic sulfur, but have poor degradation effect on organic sulfur, and the catalytic active sites are easily deactivated, making it difficult to achieve long-term desulfurization; single biological carrier materials are significantly limited by temperature, and the high-temperature characteristics of rubber asphalt flue gas will cause the desulfurization microorganisms to be deactivated, and the mass transfer efficiency is low, which cannot meet the treatment needs of high-concentration sulfur-containing flue gas.
[0004] Furthermore, existing composite functional materials lack functional zoning design for the carrier pores, leading to interference between catalytic sites and microorganisms. Micropores are easily clogged by microbial metabolites or flue gas particles, hindering the full realization of catalytic and biological synergistic effects. Consequently, the desulfurization efficiency and long-term effectiveness of these materials fail to meet the demands of engineering applications. Therefore, developing a desulfurization functional material that can adapt to the high-temperature, high-oil-mist, and multi-component sulfur-containing characteristics of rubber asphalt flue gas, achieving high efficiency, long-term effectiveness, and anti-clogging properties, has become an urgent technical problem to be solved in this field. Summary of the Invention
[0005] To address the shortcomings of existing functional materials used in rubber asphalt flue gas desulfurization technologies, such as low efficiency, easy clogging, poor stability, and inability to synergistically treat sulfides, this invention aims to provide a hierarchical porous iron-manganese-microbial composite functional material for rubber asphalt flue gas desulfurization. Through a functional zoning design, it achieves a synergistic effect between catalytic oxidation and microbial degradation, avoiding micropore clogging, improving the material's desulfurization efficiency and long-term effectiveness, and adapting to the complex operating conditions of rubber asphalt flue gas. This composite functional material comprises a hierarchical porous carrier, iron-manganese bimetallic catalytic sites, and high-temperature resistant desulfurization microorganisms. The hierarchical porous carrier has a three-level pore structure: micropores, mesopores, and macropores, achieving synergistic effects of functional zoning.
[0006] This invention provides a hierarchical porous iron-manganese-microorganism composite functional material, prepared by the following method: (1) Preparation of hierarchical porous carrier The carbon suspension and molecular sieve precursor liquid were mixed evenly, aged, and then subjected to a hydrothermal reaction. After the reaction was completed, the material was washed and dried, and then calcined to obtain a multi-level porous molecular sieve. (2) Loading of iron-manganese bimetallic catalytic sites The metal precursor liquid is dropped onto a hierarchical porous molecular sieve while grinding, then allowed to stand for impregnation and dry; then calcined and kept at a certain temperature to obtain a hierarchical porous iron-manganese functional material. (3) Fixation of high-temperature resistant desulfurization microorganisms The bacterial suspension was mixed with the hierarchical porous iron-manganese functional material for adsorption. After adsorption was completed, the unadsorbed bacteria were washed away to obtain the hierarchical porous iron-manganese-microbial composite functional material.
[0007] In the above technical solution, in step (1), the carbon suspension is prepared by the following method: ordered mesoporous carbon is uniformly dispersed in ethanol to form a carbon suspension.
[0008] In the above method for preparing carbon suspension, the mass concentration of the carbon suspension is 1.5~5%; the ordered mesoporous carbon is at least one of CMK-3, CMK-5, FDU-15, and FDU-16.
[0009] In the above technical solution, in step (1), the molecular sieve precursor liquid is prepared by the following method: the molecular sieve is mixed with sodium aluminate solution, tetraethyl orthosilicate is added dropwise, and the mixture is mixed evenly to form a molecular sieve precursor liquid.
[0010] In the above method for preparing molecular sieve precursor solution, the raw materials are selected from the following parts by mass: 0.5-2 parts of molecular sieve, 5-10 parts of sodium aluminate solution, and 5-15 parts of tetraethyl orthosilicate; the molecular sieve is at least one of ZSM-5, 13X molecular sieve, and carbon molecular sieve; the concentration of the sodium aluminate solution is 50-100 g / L.
[0011] In the above technical solution, in step (1), the aging conditions are: aging at 50~70℃ for 1~8h; the hydrothermal reaction conditions are: hydrothermal reaction at 140~180℃ for 1~2h; and the calcination conditions are: calcination at 350~550℃ for 2~10h.
[0012] In the above technical solution, in step (2), the metal precursor solution is a salt solution of iron and manganese; preferably, it is an aqueous solution of iron and manganese nitrates; the concentration of the metal precursor solution is 0.2~0.4 g / mL; the amount of the metal precursor solution used is just enough to wet the multi-level porous molecular sieve so that it does not flow or clump.
[0013] In the above technical solution, in step (2), the time for static soaking is 1~3h; the calcination conditions are: calcination at 350~550℃ for 2~10h; and the heat preservation time is 1~10h.
[0014] In the above technical solution, in step (3), the bacteria in the bacterial suspension are bacteria capable of degrading sulfides, preferably at least one of *Bacillus stearothermophilus*, *Bacillus thermophilus desulfurizationus* TS-1, *Bacillus sulfideus*, and *Acidophilus bacillus*; the bacterial content in the bacterial suspension is at least 1 × 10⁻⁶. 8 CFU / mL.
[0015] In the above technical solution, the adsorption conditions in step (3) are: adsorption for 1-3 hours at 30-40℃, 100-200 r / min and pH 6-8.
[0016] This invention provides the application of the above-mentioned graded porous iron-manganese-microorganism composite functional material in the desulfurization of rubber asphalt flue gas.
[0017] The beneficial effects of this invention are as follows: This invention utilizes the three-level pore functional partitioning structure of the adsorbent material, using micropores for loading iron-manganese bimetallic catalytic sites, mesopores for mass transfer, and macropores for microbial immobilization. This achieves spatial separation and synergistic effect between catalytic oxidation and microbial degradation, and avoids the blockage of micropores by particulate matter or microbial metabolites from the structural source. It effectively solves the problems of easy clogging and rapid efficiency decline of existing desulfurization materials, and is suitable for the characteristics of high oil mist and high particulate matter in rubber asphalt flue gas.
[0018] By employing a functional design that couples iron-manganese bimetallic catalysis with high-temperature resistant microorganisms, the iron-manganese bimetallic catalytic sites can rapidly catalyze the oxidation of inorganic sulfur and initially degrade organic sulfur, reducing the microbial load; while the high-temperature resistant microorganisms can deeply degrade catalytic intermediates, significantly improving the desulfurization efficiency of the material, with a sulfide removal rate of ≥80%.
[0019] The graded porous carrier uses modified molecular sieves as the matrix, which has good high temperature resistance and oil mist resistance, and is suitable for high temperature working conditions of rubber asphalt fumes; the iron-manganese loading and microbial immobilization methods are simple and easy to implement, without the need for complicated equipment.
[0020] The composite functional material prepared by this invention has a stable structure and long-lasting effect. It can be filled into the pretreated desulfurization reaction system without requiring large-scale modification of existing equipment. It has strong adaptability and is easy to promote and apply in engineering. It can effectively solve the problem of purifying sulfur-containing pollutants in rubber asphalt flue gas.
[0021] This invention is applicable to the efficient purification and treatment of flue gas in rubber asphalt production. It can be applied to the desulfurization reaction system of rubber asphalt flue gas to achieve efficient adsorption, catalytic oxidation and deep degradation of sulfides. Attached Figure Description
[0022] Figure 1 The image shows a SEM image of a hierarchical porous iron-manganese-microorganism composite functional material; where 1 represents the hierarchical porous carrier, 2 represents micropores, 3 represents mesopores, and 4 represents macropores.
[0023] Figure 2 This is a schematic diagram of the hierarchical pore structure of the hierarchical pore iron-manganese-microorganism composite functional material; where 1 is the hierarchical pore porous carrier, 2 is the micropore, 3 is the mesopore, 4 is the macropore, 5 is the iron-manganese bimetallic catalytic site, and 6 is the high-temperature resistant desulfurization microbial biofilm.
[0024] Figure 3 The image shows the SEM image of the graded porous iron-manganese-microorganism composite functional material described in Example 1 after flue gas adsorption.
[0025] Figure 4 The image shows a SEM image of the flue gas desulfurization material described in Comparative Example 1 after flue gas adsorption. Detailed Implementation
[0026] In this invention, the ordered mesoporous carbon CMK-3 is sourced from Nanjing Jicang Nanotechnology Co., Ltd., and has a pore size of 3.9 nm and a specific surface area of 500~1500 m². 2 Within the range of / g.
[0027] In this invention, the thermophilic Bacillus steatophilus suspension is prepared by the following method: Bacillus stearothermophilus was inoculated into LB medium and activated at 55°C for 18 h. After the culture, the bacterial suspension was centrifuged at 4000 rpm for 10 min to collect the bacterial cells, washed with sterile physiological saline and resuspended to ensure that the bacterial concentration in the suspension was not less than 1 × 10⁻⁶. 8 CFU / mL was used to obtain a suspension of Bacillus stearothermophilus.
[0028] In this invention, the thermophilic desulfurizing Bacillus TS-1 bacterial suspension is prepared by the following method: Thermophilic desulfurized Bacillus TS-1 was inoculated into LB medium and activated at 55℃ for 18 h. After the culture, the bacterial suspension was centrifuged at 4000 rpm for 10 min to collect the bacterial cells, washed with sterile physiological saline and resuspended to ensure that the bacterial concentration in the suspension was not less than 1×10⁻⁶. 8 CFU / mL was used to obtain a suspension of thermophilic desulfurized Bacillus TS-1.
[0029] Other materials used in this invention, unless otherwise stated, are commercially available. Other terms used in this invention, unless otherwise specified, generally have the meanings commonly understood by those skilled in the art. The invention is further described in detail below with reference to specific embodiments and data. The following embodiments are merely illustrative and not intended to limit the scope of the invention in any way. Example 1
[0030] The steps for preparing hierarchical porous iron-manganese-microorganism composite functional materials are as follows: (1) Preparation of hierarchical porous carrier 0.5g of ordered mesoporous carbon CMK-3 was dispersed in 30g of ethanol and sonicated for 30min to form a uniform carbon suspension. 1g of ZSM-5 molecular sieve was uniformly mixed with 6g of sodium aluminate solution (concentration 50g / L), and 8g of tetraethyl orthosilicate (TEOS) was slowly added dropwise and mixed thoroughly to form a molecular sieve precursor solution. The carbon suspension and molecular sieve precursor solution were mixed, stirred at 1000r / min for 1h, and sonicated for 30min. Then, the mixture was aged at 60℃ for 4h, followed by hydrothermal reaction at 160℃ for 1.5h. After the reaction was completed, the material was washed until neutral and dried at 105℃ for 2h. The temperature was increased to 450℃ at a heating rate of 2℃ / min, and calcined for 6h to obtain hierarchical porous ZSM-5 molecular sieve. The micropore size of the hierarchical porous ZSM-5 molecular sieve is 0.8~2nm, the mesopore size is 2~50nm, and the macropore size is >50nm.
[0031] (2) Loading of iron-manganese bimetallic catalytic sites Take 2g of hierarchical ZSM-5 molecular sieve and add deionized water dropwise until it is wetted, non-flowing, and does not clump. Record the water volume as 2mL. Dissolve 0.2g of Fe(NO3)3 and 0.24g of Mn(NO3)2 (mass ratio 1:1.2) in 2mL of deionized water to obtain a metal precursor solution (0.22g / mL). Add the metal precursor solution dropwise onto 2g of hierarchical ZSM-5 molecular sieve while grinding, and then let it stand at room temperature for 2h. Dry it in an oven at 105℃ for 2h, then heat it to 450℃ at a heating rate of 2℃ / min, calcine it at high temperature for 6h and hold it at that temperature for 4h to form FeOx-MnOx composite active sites, complete the catalytic site loading, and obtain hierarchical porous iron-manganese functional material.
[0032] (3) Fixation of high-temperature resistant desulfurization microorganisms The graded porous iron-manganese functional material was dried and activated at 105℃ for 2 hours; a suspension of *Bacillus stearothermophilus* and a suspension of *Bacillus desulfurization* TS-1 were mixed at a 1:1 ratio, and 5 mL of the mixed suspension was centrifuged and concentrated to a bacterial content of 1×10⁻⁶. 9 The concentration of CFU / mL was increased, and then 1g of hierarchical pore iron-manganese functional material was added. The material was adsorbed for 2h at 34℃, 120r / min and pH=7, allowing microorganisms to selectively enter the macroporous channels by means of the pore size effect, while the mesoporous channels were retained for flue gas mass transfer. The unadsorbed bacteria were removed by washing three times with sterile physiological saline, and the microorganisms were immobilized to obtain the hierarchical pore iron-manganese-microorganism composite functional material.
[0033] SEM images of the above-mentioned hierarchical porous iron-manganese-microbial composite functional materials are shown below. Figure 1 As shown in the figure, the composite functional material has a hierarchical pore structure, including three pore sizes: micropores, mesopores, and macropores.
[0034] I. Verification of Hierarchical Channel Structure and Function To verify the functional division of different pore structures in the hierarchical porous iron-manganese-microorganism composite functional material of the present invention, the following tests were conducted on the material: The hierarchical porous iron-manganese-microorganism composite functional material prepared in Example 1 is denoted as M0; micropore weakening sample M1 is obtained by preferentially blocking micropores through atomic layer deposition; mesopores are weakened through chemical liquid phase deposition to obtain sample M2; macropores are weakened through macromolecular pore-blocking method to obtain sample M3.
[0035] The distribution and valence state of iron and manganese were analyzed by TEM-EDS and XPS; a fixed-bed breakthrough test was conducted using H2S as a model pollutant; and the activity and quantity of microorganisms were determined by ATP and q-PCR.
[0036] The test results are shown in Tables 1 to 3: Table 1 Results of iron and manganese loading and dispersion Table 2 H2S Penetration Test Results Table 3 Results of microbial fixation and activity Table 1 shows that the iron and manganese loading and dispersion in microporous weakened sample M1 decreased significantly, proving that micropores are the main loading space for iron-manganese bimetallic catalytic sites. Table 2 shows that the breakthrough time and diffusion coefficient of mesoporous weakened sample M2 decreased most significantly, indicating that mesopores play a dominant role in reactant mass transfer. Table 3 shows that the ATP content and viable bacteria ratio of macroporous weakened sample M3 decreased significantly, indicating that macroporous structure provides the main space for microbial attachment and growth.
[0037] To aid in understanding the hierarchical pore structure described above, this invention provides a schematic diagram of the hierarchical pore structure of the iron-manganese-microorganism composite functional material, as shown below. Figure 2 As shown, 1 represents a hierarchical porous carrier, 2 represents micropores, 3 represents mesopores, 4 represents macropores, 5 represents iron-manganese bimetallic catalytic sites, and 6 represents a high-temperature resistant desulfurization microbial biofilm. This diagram is a simulation illustration and is for reference only. Example 2
[0038] The steps for preparing hierarchical porous iron-manganese-microorganism composite functional materials are as follows: (1) Preparation of hierarchical porous carrier 0.8 g of ordered mesoporous carbon CMK-3 was dispersed in 30 g of ethanol and sonicated for 30 min to form a uniform carbon suspension. 1.5 g of ZSM-5 molecular sieve was uniformly mixed with 6 g of sodium aluminate solution (concentration 75 g / L), and 8 g of tetraethyl orthosilicate (TEOS) was slowly added dropwise and mixed evenly to form a molecular sieve precursor solution. The carbon suspension and molecular sieve precursor solution were mixed, stirred at 2000 r / min for 1 h, and sonicated for 30 min. Then, it was aged at 60 °C for 5 h, followed by hydrothermal reaction at 160 °C for 1.8 h. After the reaction was completed, the material was washed until neutral and dried at 105 °C for 2 h. The temperature was increased to 450 °C at a heating rate of 2 °C / min, and calcined for 6 h to obtain hierarchical porous ZSM-5 molecular sieve. The micropore size of the hierarchical porous ZSM-5 molecular sieve is 0.8~2 nm, the mesopore size is 2~50 nm, and the macropore size is >50 nm.
[0039] (2) Loading of iron-manganese bimetallic catalytic sites Take 2g of hierarchical ZSM-5 molecular sieve and add deionized water dropwise until it is wet, non-flowing, and does not clump. Record the water volume as 2mL. Dissolve 0.2g of Fe(NO3)3 and 0.26g of Mn(NO3)2 (mass ratio 1:1.3) in 2mL of deionized water to obtain a metal precursor solution (0.23 g / mL). Add the metal precursor solution dropwise onto 2g of hierarchical ZSM-5 molecular sieve while grinding, and then let it stand at room temperature for 2h. Dry it in an oven at 105℃ for 2h, then heat it to 450℃ at a heating rate of 2℃ / min, calcine it at high temperature for 6h and hold it at that temperature for 4h to form FeOx-MnOx composite active sites, complete the catalytic site loading, and obtain hierarchical porous iron-manganese functional material.
[0040] (3) Fixation of high-temperature resistant desulfurization microorganisms The graded porous iron-manganese functional material was dried and activated at 105℃ for 2 hours; a suspension of *Bacillus stearothermophilus* and a suspension of *Bacillus desulfurization* TS-1 were mixed at a ratio of 1:1.3, and 8 mL of the mixed suspension was centrifuged and concentrated to a bacterial content of 0.5 × 10⁻⁶. 9 The concentration of CFU / mL was increased, and then 1g of hierarchical pore iron-manganese functional material was added. The material was adsorbed for 2.5h at 37℃, 130r / min and pH=7, allowing microorganisms to selectively enter the macroporous channels by means of the pore size effect, while the mesoporous channels were retained for flue gas mass transfer. The unadsorbed bacteria were removed by washing three times with sterile physiological saline, and the microorganisms were immobilized to obtain the hierarchical pore iron-manganese-microorganism composite functional material. Example 3
[0041] The steps for preparing hierarchical porous iron-manganese-microorganism composite functional materials are as follows: (1) Preparation of hierarchical porous carrier 1g of ordered mesoporous carbon CMK-3 was dispersed in 30g of ethanol and sonicated for 30min to form a homogeneous carbon suspension. 2g of ZSM-5 molecular sieve was uniformly mixed with 6g of sodium aluminate solution (concentration 100g / L), and 8g of tetraethyl orthosilicate (TEOS) was slowly added dropwise until homogeneous, forming a molecular sieve precursor solution. The carbon suspension and molecular sieve precursor solution were mixed, stirred at 3000r / min for 1h, and sonicated for 30min. The mixture was then aged at 60℃ for 4h, followed by a hydrothermal reaction at 160℃ for 2h. After the reaction, the material was washed until neutral and dried at 105℃ for 2h. The temperature was then increased to 450℃ at a rate of 2℃ / min and calcined for 6h to obtain a hierarchical porous ZSM-5 molecular sieve. The hierarchical porous ZSM-5 molecular sieve has micropores with a diameter of 0.8~2nm, mesopores with a diameter of 2~50nm, and macropores with a diameter >50nm.
[0042] (2) Loading of iron-manganese bimetallic catalytic sites Take 2g of hierarchical ZSM-5 molecular sieve and add deionized water dropwise until it is wetted, non-flowing, and does not clump. Record the water volume as 2mL. Dissolve 0.2g of Fe(NO3)3 and 0.3g of Mn(NO3)2 (mass ratio 1:1.5) in 2mL of deionized water to obtain a metal precursor solution (0.25g / mL). Add the metal precursor solution dropwise onto 2g of hierarchical ZSM-5 molecular sieve while grinding, and then let it stand at room temperature for 2h. Dry it in an oven at 105℃ for 2h, then heat it to 450℃ at a heating rate of 2℃ / min, calcine it at high temperature for 6h and hold it at that temperature for 4h to form FeOx-MnOx composite active sites, complete the catalytic site loading, and obtain hierarchical porous iron-manganese functional material.
[0043] (3) Fixation of high-temperature resistant desulfurization microorganisms The graded porous iron-manganese functional material was dried and activated at 105℃ for 2 hours; a suspension of *Bacillus stearothermophilus* and a suspension of *Bacillus desulfurization* TS-1 were mixed at a ratio of 1:1.5, and 10 mL of the mixed suspension was centrifuged and concentrated to a bacterial content of 1×10⁻⁶. 8 The concentration of CFU / mL was increased, and then 1g of hierarchical pore iron-manganese functional material was added. The material was adsorbed for 3h at 40℃, 150r / min and pH=7, allowing microorganisms to selectively enter the macroporous channels by means of the pore size effect, while the mesoporous channels were retained for flue gas mass transfer. The unadsorbed bacteria were removed by washing three times with sterile physiological saline, and the microorganisms were immobilized to obtain the hierarchical pore iron-manganese-microorganism composite functional material.
[0044] Comparative Example 1 This comparative example prepared a rubber asphalt flue gas desulfurization material. The preparation method is the same as that in Example 1 above. The difference from Example 1 is that a graded porous carrier was not prepared, that is, step (1) was missing and ordinary ZSM-5 molecular sieve was used in step (2).
[0045] Comparative Example 2 This comparative example prepared a rubber asphalt flue gas desulfurization material. The preparation method is the same as that in Example 1 above. The difference from Example 1 is that microbial fixation is not performed, that is, step (3) is missing.
[0046] Comparative Example 3 This comparative example uses activated carbon as a desulfurization material for rubber asphalt flue gas.
[0047] Comparative Example 4 This comparative example uses nano-Fe3O4-supported manganese porphyrin (Xi'an Delta Biotechnology Co., Ltd.) as a desulfurization material for rubber asphalt flue gas.
[0048] Comparative Example 5 This comparative example uses polyvinyl alcohol as a microbial immobilization carrier to immobilize Bacillus stearothermophilus, without introducing hierarchical pore structure or functional modification, and uses it as a desulfurization material for rubber asphalt flue gas.
[0049] Its preparation method is as follows: Polyvinyl alcohol was dissolved in deionized water and heated to prepare a polyvinyl alcohol solution with a concentration of 80 g / L; after cooling, 2 g of the polyvinyl alcohol solution (80 g / L) was mixed with a suspension of Bacillus stearothermophilus (1 × 10⁻⁶). 8 The CFU / mL solution was mixed evenly at a volume ratio of 1:1. The mixture was then added dropwise to 10g of boric acid-calcium chloride curing solution to form gel particles. After standing and curing, the particles were removed and washed with distilled water to obtain immobilized thermophilic Bacillus stearothermophilus, which was used as a desulfurization material for rubber asphalt flue gas.
[0050] II. Flue Gas Desulfurization Test 1. Verification of odor removal effect The above-mentioned flue gas desulfurization materials were fused with rubber asphalt to prepare odor-neutral rubber asphalt, and the mixture was then tested. The steps are as follows: 1.2g of functional material (examples and comparative examples) was added to 240g of rubber asphalt (molten state), and stirred at 175°C for 30 minutes to obtain odorless rubber asphalt.
[0051] The multi-functional gas detection device was connected to detect the gas for 30 minutes, and the content of each harmful gas was measured. The emission reduction rate was calculated by comparing the emission of odorless asphalt with that of rubber asphalt according to the emission test method of odorless asphalt concrete (GB / T 43882-2024). The test results are shown in Table 4.
[0052] Table 4. Detection Results of Odorless Rubber Asphalt Fume Test results show that the composite functional material prepared by this invention maintains stable desulfurization efficiency, with a sulfide emission reduction rate of over 80%, a VOC emission reduction rate of over 50%, and a NO emission reduction rate of over 50%. x The emission reduction rate can reach more than 50%, and all indicators have reached or exceeded the established emission reduction targets.
[0053] 2. Long-term effectiveness verification 1.2g of functional material (examples and comparative examples) was added to 240g of rubber asphalt (molten state), and stirred at 175°C for 30 minutes to obtain odorless rubber asphalt.
[0054] The storage temperature was 175℃, and the storage time was 21 days. The content of harmful gases was measured every other day, and the emission reduction rate was calculated by comparing it with rubber asphalt. The test results are shown in Tables 5-7.
[0055] Table 5. 21-day sulfide emission reduction rate of odorless rubber asphalt (%) Table 6 Odorless Rubber Asphalt 21-Day NO x Emission reduction rate (%) Table 7. VOC emission reduction rate of odorless rubber asphalt after 21 days (%) Test results show that the composite functional material prepared by this invention has a sulfide emission reduction rate of >60%, a NOx emission reduction rate of ≥40%, and a VOC emission reduction rate of >40% after 21 days, while still maintaining its odor-neutralizing effect and exhibiting long-lasting efficacy.
[0056] 3. Anti-clogging performance verification Rubber asphalt was added to a three-necked flask and placed on a heating mantle to heat to 175°C. A thermometer was inserted into the left end and left open, while the top opening was sealed. A cork was inserted into the right end and connected to a vent tube containing 5g of functional material (Example 1 and Comparative Example 1). A vacuum device was connected to the other side of the vent tube and operated for 30 minutes. The functional material was then removed and subjected to scanning electron microscopy (SEM). The test results are as follows: Figure 3 , Figure 4 As shown.
[0057] from Figure 3 It can be seen that the composite functional material in Example 1 showed almost no clogging after the desulfurization test. Figure 4 As shown in the red circle, the channel is severely blocked by particles in the flue gas. It can be seen that the micropores in Comparative Example 1 are significantly blocked, indicating that the hierarchical porous iron-manganese-microorganism composite functional material prepared in this invention has good anti-clogging performance.
[0058] In summary, the hierarchical porous iron-manganese-microorganism composite functional material prepared by this invention has good desulfurization efficiency, long-lasting effect and anti-clogging performance, and can be adapted to the complex working conditions of rubber asphalt flue gas, effectively achieving efficient purification of sulfur-containing flue gas.
[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.
Claims
1. A hierarchical porous iron-manganese-microorganism composite functional material, characterized in that, It is prepared by the following method: (1) Preparation of hierarchical porous carrier The carbon suspension and molecular sieve precursor liquid were mixed evenly, aged, and then subjected to a hydrothermal reaction. After the reaction was completed, the material was washed and dried, and then calcined to obtain a multi-level porous molecular sieve. (2) Loading of iron-manganese bimetallic catalytic sites The metal precursor liquid is dropped onto a hierarchical porous molecular sieve while grinding, then allowed to stand for impregnation and dry; then calcined and kept at a certain temperature to obtain a hierarchical porous iron-manganese functional material. (3) Fixation of high-temperature resistant desulfurization microorganisms The bacterial suspension was mixed with the hierarchical porous iron-manganese functional material for adsorption. After adsorption was completed, the unadsorbed bacteria were washed away to obtain the hierarchical porous iron-manganese-microbial composite functional material.
2. The hierarchical porous iron-manganese-microorganism composite functional material according to claim 1, characterized in that, In step (1), the carbon suspension is prepared by the following method: ordered mesoporous carbon is uniformly dispersed in ethanol to form a carbon suspension; The mass concentration of the carbon suspension is 1.5-5%; the ordered mesoporous carbon is at least one of CMK-3, CMK-5, FDU-15, and FDU-16.
3. The hierarchical porous iron-manganese-microorganism composite functional material according to claim 1, characterized in that, In step (1), the molecular sieve precursor solution is prepared by the following method: mixing molecular sieve with sodium aluminate solution, adding tetraethyl orthosilicate dropwise, mixing evenly to form a molecular sieve precursor solution.
4. The hierarchical porous iron-manganese-microorganism composite functional material according to claim 3, characterized in that, The raw materials are selected from the following parts by weight: 0.5-2 parts of molecular sieve, 5-10 parts of sodium aluminate solution, and 5-15 parts of tetraethyl orthosilicate; the molecular sieve is at least one of ZSM-5, 13X molecular sieve, and carbon molecular sieve; the concentration of the sodium aluminate solution is 50-100 g / L.
5. The hierarchical porous iron-manganese-microorganism composite functional material according to claim 1, characterized in that, In step (1), the aging conditions are: aging at 50~70℃ for 1~8h; the hydrothermal reaction conditions are: hydrothermal reaction at 140~180℃ for 1~2h; and the calcination conditions are: calcination at 350~550℃ for 2~10h.
6. The hierarchical porous iron-manganese-microorganism composite functional material according to claim 1, characterized in that, In step (2), the metal precursor solution is an aqueous solution of iron and manganese nitrates; the concentration of the metal precursor solution is 0.2~0.4 g / mL.
7. The hierarchical porous iron-manganese-microorganism composite functional material according to claim 1, characterized in that, In step (2), the time for static soaking is 1-3 hours; the calcination conditions are: calcination at 350-550℃ for 2-10 hours; and the heat preservation time is 1-10 hours.
8. The hierarchical porous iron-manganese-microorganism composite functional material according to claim 1, characterized in that, In step (3), the bacteria in the bacterial suspension are at least one of *Bacillus stearothermophilus*, *Bacillus desulfurothermophilus* TS-1, *Bacillus sulfideus*, and *Acidophilus bacillus*; the bacterial content of the bacterial suspension is at least 1 × 10⁻⁶. 8 CFU / mL.
9. The hierarchical porous iron-manganese-microorganism composite functional material according to claim 1, characterized in that, In step (3), the adsorption conditions are: adsorption at 30~40℃, 100~200 r / min, and pH 6~8 for 1~3h.
10. The application of the graded porous iron-manganese-microorganism composite functional material according to any one of claims 1 to 9 in the desulfurization of rubber asphalt flue gas.