A starch-co-laccase modified millet straw adsorbent material, its preparation method and application

Abstract

This invention discloses an amylase-co-laccase-modified millet straw adsorbent material, its preparation method, and its application, belonging to the technical field of adsorbent materials. The preparation steps of the amylase-co-laccase-modified millet straw adsorbent material include: soaking cooked millet straw in an amylase solution, removing it, soaking it in a laccase solution, then inactivating the enzyme, washing, and drying to obtain the amylase-co-laccase-modified millet straw adsorbent material. The raw material used in this invention—millet straw—is an agricultural waste resource, abundant in resources and rich in active groups such as cellulose and lignin, possessing excellent adsorption potential. This invention uses millet straw as a raw material to develop a highly efficient bioadsorbent for nicotine adsorption through modification and other technologies, and prepares a high-adsorption-capacity millet straw adsorbent material through optimized preparation processes. This is beneficial for protecting human health and also features low energy consumption and green, efficient utilization of millet straw agricultural and forestry waste.

Description

Technical Field

[0001] This invention belongs to the field of adsorbent materials technology, specifically relating to an amylase-co-laccase modified millet straw adsorbent material, its preparation method, and its application. Background Technology

[0002] Tobacco dependence refers to a complex physiological and psychological state caused by prolonged exposure to tobacco and its active ingredients. It is characterized by a craving for tobacco, uncontrollable use, and a pronounced response to withdrawal symptoms. Both animal and human studies have revealed that nicotine in tobacco not only induces tolerance, dependence, and sensitization, but also produces withdrawal symptoms, demonstrating that the core mechanism of tobacco addiction is primarily nicotine addiction. Nicotine, the main alkaloid component of tobacco, is widely present throughout the entire tobacco plant, especially in the leaves. A standard cigarette typically contains approximately 3 to 10 milligrams of nicotine. Research indicates that secondhand smoke is even more harmful than smoking itself. Secondhand smoke can cause upper respiratory tract damage in healthy individuals, directly harming the respiratory system. Furthermore, secondhand smoke can increase blood viscosity, damaging the vascular endothelial structure and leading to narrowing of blood vessels, significantly increasing the risk of coronary artery insufficiency and potentially exacerbating the risk of heart attacks. Therefore, adopting effective measures to remove or reduce the nicotine content in cigarette smoke is of great significance for reducing smokers' addiction, improving indoor air quality, and protecting human health. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides an adsorbent material of millet straw modified with amylase-co-laccase, its preparation method, and its application.

[0004] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of this invention is to provide a method for preparing an amylase-co-laccase modified millet straw adsorbent material, comprising the following steps: The cooked millet straw was soaked in an amylase solution, then removed and soaked in a laccase solution. The enzyme was then inactivated, and the straw was washed and dried to obtain the amylase-co-laccase modified millet straw adsorbent material.

[0005] Preferably, the concentration of the amylase solution is 0.07 mg / mL, and the soaking time in the amylase solution is 30 min.

[0006] Preferably, the concentration of the laccase solution is 0.38 mg / mL, and the soaking temperature in the laccase solution is 66.8°C for 30 min.

[0007] Preferably, the drying process further includes a sterilization step.

[0008] Preferably, the drying process further includes a crushing and sieving step.

[0009] More preferably, the sieving is performed through a 40-mesh sieve.

[0010] The second technical solution of the present invention provides an amylase-co-laccase modified millet straw adsorbent material prepared according to the above-mentioned preparation method of amylase-co-laccase modified millet straw adsorbent material.

[0011] The third technical solution of the present invention provides an application of the above-mentioned amylase-co-laccase modified millet straw adsorbent material in the preparation of cigarette filters.

[0012] Preferably, in cigarettes with a length of 84 mm, the amount of amylase-co-laccase modified millet straw adsorbent material added to the cigarette filter is 0.11 g.

[0013] The beneficial technical effects of the present invention are as follows: The raw material used in this invention—millet straw—is an abundant agricultural waste resource rich in active groups such as cellulose and lignin, possessing excellent adsorption potential. This invention utilizes millet straw as a raw material to develop a highly efficient biosorbent for nicotine adsorption through modification and other technologies. Furthermore, by optimizing the preparation process, a high-adsorption-capacity millet straw adsorbent material was prepared, which is beneficial for protecting human health and features low energy consumption and green, efficient utilization of millet straw agricultural and forestry waste. Attached Figure Description

[0014] Figure 1 The standard curve of nicotine solution plotted for this invention.

[0015] Figure 2 This is a schematic diagram of the nicotine adsorption device of the present invention.

[0016] Figure 3 The adsorption effect and removal rate of nicotine on the various millet straw adsorbent materials prepared in Example 1 are shown.

[0017] Figure 4 The adsorption effect and removal rate of nicotine on each millet straw adsorbent material prepared in Comparative Example 1 were investigated.

[0018] Figure 5 The adsorption effect and removal rate of nicotine on each millet straw adsorbent material prepared in Comparative Example 2 were investigated.

[0019] Figure 6 The adsorption effect and removal rate of nicotine on each millet straw adsorbent material prepared in Comparative Example 3 were investigated.

[0020] Figure 7This study investigates the effect of the interaction between laccase concentration and water bath temperature on nicotine removal rate in an orthogonal experiment.

[0021] Figure 8 This study investigates the effect of the interaction between amylase concentration and water bath temperature on nicotine removal rate in an orthogonal experiment.

[0022] Figure 9 The influence of particle size of millet straw adsorbent material on nicotine removal rate under the influence of external factors.

[0023] Figure 10 The effect of the amount of millet straw adsorbent added on nicotine removal rate under the influence of external factors.

[0024] Figure 11 The influence of adsorption temperature on nicotine removal rate among external factors.

[0025] Figure 12 Infrared spectra of raw residue and millet straw adsorption materials before and after adsorption.

[0026] Figure 13 The images show SEM images of the original residue and millet straw adsorbent material before and after adsorption. (a) shows the original residue, (b) shows the millet straw adsorbent material before adsorption, and (c) shows the millet straw adsorbent material after adsorption.

[0027] Figure 14 The nicotine removal rate of each adsorbent material was compared in a horizontal comparison experiment. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0029] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0030] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0031] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0032] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0033] Example 1 amylase and colaccase: (1) Sampling: Take 5 portions of millet straw that have been dried at constant temperature, totaling 50 g, and weigh them equally.

[0034] (2) Steaming at 100 ℃: Five portions of millet straw were steamed at a constant temperature of 100 ℃ for 30 min.

[0035] (3) Soaking: Soak 5 portions of millet straw in 0.15 mol / L amylase solution for 30 min.

[0036] (4) Water bath: Take one portion of laccase solution with a concentration range of 0.1, 0.2, 0.3, 0.4 and 0.5 mg / mL and soak the five groups of grain straw samples in a constant temperature water bath device with a preset temperature of 50 ℃ for 30 min.

[0037] (5) Enzyme inactivation: Five millet straw samples were treated in an 80 ℃ water bath for 20 min.

[0038] (6) Washing and drying: After neutral washing, millet straw is placed in an 80 ℃ hot air sterilization box for 24 hours.

[0039] (7) Crushing: The straw is crushed using a crusher.

[0040] (8) Screening: The crushed residue is screened and retained through a 40-mesh sieve.

[0041] Comparative Example 1 Alkali heat scalding: (1) Sampling: Take 5 portions of millet straw that have been dried at constant temperature, totaling 50 g, and weigh them equally.

[0042] (2) Steaming at 100 ℃: Steam five portions of millet straw at a constant temperature of 100 ℃ for 30 min.

[0043] (3) Water bath: Five portions of cooked millet straw were placed in NaOH solutions of 0.1, 0.2, 0.3, 0.4 and 0.5 mol / L respectively, and extracted for 30 min using a constant temperature water bath device under constant temperature conditions of 60 ℃.

[0044] (4) Rinsing: Take out the millet straw samples from the five conical flasks and place them in a sieve. Then rinse them continuously in tap water until the pH value is neutral. After rinsing, weigh the samples and record their mass data in detail.

[0045] (5) Drying: After the millet straw has been thoroughly drained, it is evenly spread in a petri dish and marked. Then it is placed in a hot air sterilization box and dried at a constant temperature of 80 ℃.

[0046] (6) Sieving: After the grain straw reaches a constant weight, it is taken out of the hot air sterilization chamber, weighed accurately using an electronic balance, then crushed, and sieved using a 40-mesh standard sieve. After sieving, the sample mass is re-weighed, and finally the processed sample is packaged into sealed bags and properly stored for later use.

[0047] Comparative Example 2 Sodium hypochlorite co-cellulase: (1) Sampling: Take 50 g of millet straw that has been dried at a constant temperature, divide it into 5 equal parts and weigh them.

[0048] (2) Steaming at 100 ℃: Five portions of millet straw were steamed at a constant temperature of 100 ℃ for 30 min.

[0049] (3) Soaking: Five portions of millet straw were soaked in 0.1 mol / L NaClO solution for 30 min.

[0050] (4) Water bath: Take one portion of hemicellulase solution with a concentration range of 0.1, 0.2, 0.3, 0.4 and 0.5 mg / mL and soak the five groups of grain straw samples respectively. Then, place the treated samples in a water bath device with a constant temperature of 50 ℃ and keep warm for 30 min to complete the pretreatment step.

[0051] (5) Enzyme inactivation: Five millet straw samples were subjected to a water bath and then heat-treated at 70-75 ℃ for 20 min.

[0052] (6) Washing and drying: After washing the millet straw until it is neutral, place it in an 80 ℃ hot air sterilization chamber for 24 hours.

[0053] (7) Crushing: The straw is crushed using a crusher.

[0054] (8) Sieving: The crushed residue is sieved through a 40-mesh sieve.

[0055] Comparative Example 3 Ferric chloride co-cellulase: (1) Sampling: Take 5 portions of millet straw that have been dried at constant temperature, totaling 50 g, and weigh them equally.

[0056] (2) Steaming at 100 ℃: Five portions of millet straw were steamed at a constant temperature of 100 ℃ for 30 min.

[0057] (3) Soaking: Soak millet straw in 0.1 mol / L FeCl3 solution for 30 min.

[0058] (4) Water bath: Take one portion of cellulase solution with a concentration range of 0.1, 0.2, 0.3, 0.4 and 0.5 mg / mL and soak the five groups of grain straw samples in the solution. Keep them in a constant water bath at 50 ℃ for 30 min.

[0059] (5) Enzyme inactivation: Five millet straw samples were treated in an 80 ℃ water bath for 10 min.

[0060] (6) Wash and dry: Rinse with running water until neutral, and dry in an 80 ℃ hot air sterilizer for 24 hours until constant weight.

[0061] (7) Crushing: Use a crusher to crush the millet straw.

[0062] (8) Sieving: The crushed residue is sieved through a 40-mesh sieve and retained.

[0063] Plotting the standard curve for nicotine solution: Nicotine solutions with concentrations of 0.2 g / mL, 0.4 g / mL, 0.6 g / mL, 0.8 g / mL, 1.0 g / mL, 1.2 g / mL, 1.4 g / mL, and 1.6 g / mL were prepared. The absorbance at 260 nm was measured, and three parallel replicate measurements were performed to obtain a standard curve for the nicotine solutions. The standard curve for the nicotine solutions is shown in [reference needed]. Figure 1 .

[0064] Assemble the adsorption device: according to Figure 2 The nicotine adsorption device shown is assembled as follows: point a is the rubber tube opening for placing the cigarette; point b is the pipette; point c is the rubber stopper (for sealing); and point d is the suction flask.

[0065] Methods for determining nicotine removal rate: 1. Using sterilized tweezers and scissors, remove the cellulose acetate from the cigarette (Hongqiqu), leaving 3 / 5 of the cellulose acetate to make experimental cigarettes.

[0066] 2. Weigh 0.11 g of the millet straw adsorbent material prepared in Example 1 and Comparative Examples 1-3, put it into the filter paper sleeve with the cellulose acetate removed, and then insert 1.5 cm of cellulose acetate.

[0067] 3. Conduct the experiment at 30℃. Place the prepared experimental tobacco on top of the adsorption device and secure it with a water-stop clamp. Then start the vacuum pump until the pressure reading of the circulating water vacuum pump stabilizes at 0.09 MPa, accompanied by the generation of a large number of bubbles, indicating that the system has reached the expected vacuum state. Immediately turn off the vacuum pump and the water-stop clamp. At this time, release the water-stop clamp and then light the cigarette. After the cigarette has completely burned, ensure that the smoke is fully mixed with 150 mL of distilled water. After the mixture has been left for 20 minutes, transfer it to a beaker and stir thoroughly. Determine the nicotine content in the mixture using the standard curve method, and further calculate the nicotine removal rate. The calculation formula is shown in equation (1).

[0068] (1) In formula (1), C0: the nicotine concentration of cigarette smoke dissolved in distilled water after retaining 1.5 cm of cellulose acetate without the addition of adsorbent; C t The concentration of nicotine in cigarette smoke dissolved in distilled water after retaining 1.5 cm of cellulose acetate with added adsorbent.

[0069] The adsorption effects and removal rates of nicotine by the various millet straw adsorbents prepared in Examples 1 and Comparative Examples 1-3 are shown in the following figures. Figures 3-6 .

[0070] from Figure 3 As can be seen, for the millet straw adsorbent material prepared in Example 1, the removal rate of the millet straw adsorbent material showed an increasing trend when the concentration of laccase was between 0.1 mg / mL and 0.3 mg / mL, and although there were fluctuations thereafter, it still showed a decreasing trend; the trend of adsorption capacity was consistent with the trend of removal rate, and the nicotine removal rate of this method was 59.3%. The adsorption performance of the millet straw adsorbent material was relatively good when the concentration of laccase was 0.3 mL.

[0071] from Figure 4 As can be seen, for the millet straw adsorbent material prepared in Comparative Example 1, the removal rate gradually approaches a plateau with increasing NaOH concentration, and the adsorption capacity also decreases with increasing NaOH concentration. Due to the decrease in removal rate leading to a reduction in adsorbable substances, the yield of this method is 50.8%. The adsorption performance of the millet straw adsorbent material is relatively good when the NaOH concentration is 0.1 mol / L.

[0072] from Figure 5As can be seen, for the millet straw adsorbent material prepared in Comparative Example 2, the removal rate increased with the concentration gradient of hemicellulase between 0.1 mg / mL and 0.3 mg / mL, but the adsorption effect decreased significantly after 0.3 mg / mL. The trend of adsorption capacity change was correlated with the removal rate, because more adsorption sites were released when the removal rate was higher. The yield of this method was 33.3%. The adsorption performance of the millet straw adsorbent material was relatively good when the concentration of hemicellulase was 0.3 mg / mL.

[0073] from Figure 6 As can be seen, for the millet straw adsorbent material prepared in Comparative Example 3, the removal rate increased when the cellulase concentration gradient was between 0.1 mg / mL and 0.4 mg / mL, and then decreased after 0.5 mg / mL; the adsorption capacity also increased with increasing cellulase concentration, consistent with the trend of removal rate change, and the yield of this method was 47.3%. The adsorption effect of the millet straw adsorbent material was better when the cellulase concentration was 0.04 mg / mL.

[0074] Based on the above structures, the adsorption effect of millet straw adsorbent materials obtained by the four treatment methods on nicotine is ranked as follows: amylase-laccase > ferric chloride-cellulase > alkaline heat treatment > sodium hypochlorite-hemicellulase. The preparation method in Example 1 is the best.

[0075] The preparation parameters of Example 1 were optimized using orthogonal experiments. A three-factor, five-level coding table was set up (see Table 1), and the optimal treatment process was determined through a quadratic orthogonal rotational regression combination experiment.

[0076] Table 1 Factor Coding Table Based on the factor coding table above, 23 experimental combinations were obtained using DPS software. Experiments were conducted, removal rates were measured, and data were analyzed using DPS software. In the quadratic rotational regression orthogonal experimental design combination table, X1 represents laccase (mg / mL), X2 represents amylase (mg / mL), and X3 represents water bath temperature (°C). The measurement results are shown in Table 2.

[0077] Table 2 Orthogonal Experimental Design Combination Table An analysis of variance was performed on the experimental data of 23 combinations of the orthogonal experimental design. The results are shown in Table 3. In the analysis of variance table, X1 is the concentration of laccase, X2 is the concentration of amylase, and X3 is the water bath temperature.

[0078] Table 3. Analysis of first-order variance Data were analyzed using DPS software to obtain the concentrations of laccase (mg / mL), amylase (mg / mL), and water bath temperature (°C). The regression equation was: Y=49.72102+1.47909X1-0.19348X2+0.56272X3+0.39919X1 2 -0.55010X2 2 -3.20882X3 2 +0.37000X1X2+3.29750X1X3-2.29250X2X3 Significance level α=0.10 was retained, and insignificant levels were removed, resulting in the simplified regression equations of the three factors and the removal rate Y: Y=49.72102+1.47909X1-3.20882X3 2 +3.29750X1X3-2.29250X2X3 At a significance level of 0.01, the model's lack of fit F1 = 6.592. <F 0.01(5,8) =6.63, indicating that the experimental error is very small and all unknown factors have been taken into account in the experimental design; regression F2=4.538>F (9, 13) =4.19, indicating that the regression equation is highly significant, and the experiment suggests that Y max =58.94%, the measured value / predicted value = 0.98, which is close to 1, indicating that the prediction is accurate and the model is valid.

[0079] The simplified regression equation shows that the interaction between factors X1X3 and X2X3 has a significant impact on the removal rate. Therefore, the effects of laccase concentration (mg / mL), amylase concentration (mg / mL), and water bath temperature (°C) on the removal rate need to be considered, while other factors are set to zero. The effects of factors X1X3 on the nicotine removal rate are shown in Table 4 and [Table data missing]. Figure 7 The effects of factors X2 and X3 on nicotine removal rate are shown in Table 5. Figure 8 .

[0080] Table 4. Effects of laccase concentration and water bath temperature on removal rate From Table 4 and Figure 7 It can be seen that when the amylase concentration remains constant, the effects of laccase concentration and water bath temperature on the experiment have reached a highly significant level. As shown in the table, the highest point is (1.682,1), that is, the removal rate is the highest at a laccase concentration of 0.38 mg / mL and a water bath temperature of 66.8 ℃, reaching 54.54%.

[0081] Table 5. Effects of amylase concentration and water bath temperature on removal rate From Table 5 and Figure 8 It can be seen that when the laccase concentration is constant, the effects of amylase concentration and water bath temperature on the experiment have reached a highly significant level. As shown in the table, the highest point is (-1.682, 0.5), that is, the highest removal rate of 50.85% is achieved when the amylase concentration is 0.07 mg / mL and the water bath temperature is 33.2 ℃.

[0082] The influence of external factors on nicotine removal efficiency was further investigated. The method for determining the nicotine removal rate was the same as above, and the preparation conditions of the millet straw adsorbent material were the optimal conditions.

[0083] A. The effect of millet straw adsorbent particle size on nicotine removal efficiency was investigated. The prepared millet straw adsorbent was sieved in batches through sieves with diameters of 10, 20, 30, 40, and 50 meshes, respectively. The effect of millet straw adsorbent particle size on nicotine removal rate is shown in [reference needed]. Figure 9 .

[0084] from Figure 9 As can be seen, the removal rate of the adsorbent material first increases and then decreases with the increase of sieve mesh size. Analysis of variance results show that the removal rates of nicotine by millet straw adsorbents with different particle sizes exhibit extremely significant differences at the 1% level (F=429.309, P=0.0001<0.001). Multiple comparisons show that the removal rate is highest at 40 mesh (57.30%), significantly better than other particle sizes (P<0.05), while the removal rate is lowest at 10 mesh (36.50%). This indicates that at 40 mesh, the adsorbent material has a larger particle size and greater inter-particle size, providing a larger specific surface area and active sites, thus significantly improving the adsorption effect. Furthermore, according to market research, larger mesh sizes are more easily inhaled into the lungs, potentially affecting human health. In conclusion, at 40 mesh, modified millet straw exhibits the best adsorption effect for nicotine, reaching 57.3%, which aligns with the market research trend.

[0085] B. To investigate the effect of millet straw adsorbent dosage on nicotine removal efficiency, the dosage of millet straw adsorbent in the nicotine removal rate determination method was adjusted to 0.09 g, 0.11 g, 0.13 g, 0.15 g, and 0.17 g. The effect of millet straw adsorbent dosage on nicotine removal rate is shown in [reference needed]. Figure 10 .

[0086] from Figure 10As can be seen, with the increase of the added amount, the adsorption effect of the adsorbent material on nicotine showed a trend of first increasing and then decreasing. Analysis of variance results showed that the removal rate of nicotine by different amounts of millet straw adsorbent reached a highly significant difference at the 1% level (F=367.32, P=0.0001<0.001), but there was no significant difference between 0.09 g and 0.17 g. Multiple comparisons showed that the removal rate reached its peak (54.81%) at 0.11 g. This indicates that an appropriate amount of adsorbent can provide sufficient active sites, while excessive adsorbent may lead to aggregation or competitive adsorption. At an added amount of 0.11 g, the modified millet straw showed the best adsorption effect on nicotine, with a removal rate of 54.8%.

[0087] C. To investigate the effect of adsorption temperature on nicotine removal efficiency, the adsorption temperature in the method for determining nicotine removal rate was adjusted to 22 ℃, 24 ℃, 26 ℃, 28 ℃, and 30 ℃. The effect of adsorption temperature on nicotine removal rate is shown in [reference needed]. Figure 11 .

[0088] from Figure 11 As can be seen, the adsorption efficiency of the adsorbent material for nicotine increases with increasing temperature. Analysis of variance results show highly significant differences in the removal rate of nicotine by the millet straw adsorbent at the 1% level at different temperatures (F=86.849, P=0.0001<0.001), but no significant difference between 22 ℃ and 24 ℃. The highest removal rate (57.32%) was achieved at 30 ℃, significantly higher than the lowest value (43.90%) at 22 ℃. This trend suggests that increasing temperature may promote molecular diffusion rate and adsorption kinetics, thereby improving the removal rate.

[0089] Millet straw adsorbent material was prepared under optimal conditions, and adsorption experiments were conducted at 30℃ with a 40-mesh sieve, an addition amount of 0.11 g, and a temperature of 30℃ (the method is the same as the method for determining nicotine removal rate). Elemental content, infrared spectroscopy, scanning electron microscopy, and specific surface area, pore volume, and pore size were determined for both the unmodified raw millet straw pulverized and sieved material (raw residue) and the millet straw adsorbent material before and after adsorption. The results of elemental content determination are shown in Table 6; the infrared spectra are shown in [Table data missing]. Figure 12 Where a represents the original residue, b represents the millet straw adsorbent material before adsorption, and c represents the millet straw adsorbent material after adsorption; SEM images are shown below. Figure 13 Among them, (a) is the original residue, (b) is the millet straw adsorbent material before adsorption, and (c) is the millet straw adsorbent material after adsorption; the results of specific surface area, pore volume and pore size measurement are shown in Table 7.

[0090] Table 6 Elemental Analysis Results Table 6 shows that the contents of C, H, N, and S elements in the modified millet straw all changed, indicating that the modification treatment significantly increased the nitrogen content, confirming that nicotine was successfully fixed on the surface of the millet straw through chemisorption. The increased carbon content indicates that the carbon skeleton participated in π-π conjugated adsorption. The increased H content after modification suggests that the optimization treatment may have increased the number of -OH and other groups in the material, which played a certain role in the adsorption of nicotine. The data confirm that both chemisorption and physical adsorption contributed to the efficient adsorption of nicotine.

[0091] Figure 12 The spectrum shows that at a wavenumber of 3400 cm⁻¹ -1 ~3600cm -1 There are -OH stretching peaks on both sides; at 1600 cm⁻¹ -1 ~1680cm -1 There are -C=C stretching peak vibrations on both sides; at 2900cm -1 There are -CH stretching peak vibrations on both sides; at 1700 cm⁻¹ -1 The presence of -C=O stretching peaks on both sides indicates that groups such as -OH, -C=C, -CH, and -C=O undergo changes during the adsorption process of the millet straw adsorbent, proving that these groups play a role in the adsorption of substances in the flue gas.

[0092] Figure 13 The results show that the surface of raw millet straw has a rough natural structure with natural fiber arrangement and a small amount of impurities, and the pores are unevenly distributed and relatively large. Modified millet straw exhibits increased porosity, and the presence of multiple wrinkles highlights the active sites. These structures provide millet straw with a certain capacity for nicotine adsorption. After adsorption, the surface of the millet straw is covered with particles, which may fill the original pores, reducing porosity and making the surface smoother. In conclusion, millet straw treated through the optimized process has a greater advantage in nicotine adsorption.

[0093] Table 7 Results of specific surface area and pore size measurements Table 7 shows that the porosity of millet straw was significantly improved after modification, indicating that the modification process effectively removed nicotine and formed new pore structures, synergistically increasing the adsorption and mass transfer potential of the material. Modified millet straw is a porous material with a large specific surface area, high activity, and strong adsorption capacity.

[0094] Further comparative analysis was conducted between the millet straw adsorbent prepared under optimal conditions and other adsorbents, using the same adsorption experimental methods as above: The materials compared horizontally included seven types: raw millet straw, modified millet straw, activated carbon (granules), bamboo charcoal, diatomaceous earth (powder), D101 macroporous resin, and cellulose acetate. The nicotine removal rate determined by the adsorption experiment is shown in [link to relevant data]. Figure 14The average adsorption values ​​are shown in Table 8.

[0095] Table 8 Comparison of nicotine removal effects of different materials Figure 14 As shown in Table 8, at the same temperature of 25 °C, the adsorption effect is as follows: modified millet straw residue > diatomaceous earth (powder) > activated carbon (granules) > bamboo charcoal > cellulose acetate > D101 macroporous resin > original millet straw residue.

[0096] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a starch amylase auxiliary laccase modified millet straw adsorption material, characterized in that, Includes the following steps: The cooked millet straw was soaked in an amylase solution, then removed and soaked in a laccase solution. The enzyme was then inactivated, and the straw was washed and dried to obtain the amylase-co-laccase modified millet straw adsorbent material.

2. The method for preparing the amylase-co-laccase modified millet straw adsorbent material according to claim 1, characterized in that, The concentration of the amylase solution was 0.07 mg / mL, and the soaking time in the amylase solution was 30 min.

3. The method for preparing the amylase-co-laccase modified millet straw adsorbent material according to claim 1, characterized in that, The concentration of the laccase solution was 0.38 mg / mL, and the soaking temperature in the laccase solution was 66.8℃ for 30 min.

4. The method for preparing the amylase-co-laccase modified millet straw adsorbent material according to claim 1, characterized in that, The drying process also includes a disinfection step.

5. The method for preparing the amylase-co-laccase modified millet straw adsorbent material according to claim 1, characterized in that, The drying process also includes a crushing and sieving step.

6. The method for preparing the amylase-co-laccase modified millet straw adsorbent material according to claim 5, characterized in that, The sieving process is a 40-mesh sieve.

7. An amylase-co-laccase-modified millet straw adsorbent material prepared by the method for preparing amylase-co-laccase-modified millet straw adsorbent material according to any one of claims 1 to 6.

8. The application of the amylase-co-laccase modified millet straw adsorbent material according to claim 7 in the preparation of cigarette filters.

9. The application according to claim 8, characterized in that, In cigarettes with a length of 84mm, the amount of amylase-co-laccase modified millet straw adsorbent material added to the cigarette filter is 0.11g.

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