Environment-friendly hydrogen peroxide catalytic removal agent and preparation method thereof

Abstract

The application discloses a novel environment-friendly hydrogen peroxide catalytic removal agent and a preparation method thereof, and relates to the technical field of water treatment. The novel environment-friendly hydrogen peroxide catalytic removal agent is composed of a composite salt, a natural extraction enzyme liquid, modified catalase prepared from modified catalase of hydrogen peroxide enzyme immobilized by modified chitosan and an EDTA compound; the novel environment-friendly hydrogen peroxide catalytic removal agent has good hydrogen peroxide removal effect, and the modified catalase has good stability; the natural extraction enzyme liquid is purified in the application, and the removal effect of the novel environment-friendly hydrogen peroxide catalytic removal agent on hydrogen peroxide is further improved.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to a novel environmentally friendly hydrogen peroxide catalytic removal agent and its preparation method. Background Technology

[0002] In recent years, the rapid development of my country's semiconductor industry and the mass production of various electronic components have led to the accumulation of residual impurities on the surfaces of components such as wafers and chips. These residual organic substances can severely impact chip performance and cause defects, significantly reducing product yield. Therefore, hydrogen peroxide is often added during the electronics manufacturing process to remove residual organic matter from wafers. Wastewater discharged during production, such as grinding wastewater, ammonia nitrogen wastewater, copper-containing wastewater, and fluoride-containing wastewater, all contain a certain concentration of hydrogen peroxide. If this hydrogen peroxide is not removed beforehand during wastewater treatment and recycling, it can cause oxidation damage to equipment materials or reduce processing efficiency.

[0003] With the widespread application of hydrogen peroxide, residual hydrogen peroxide needs to be reduced before wastewater treatment. Common methods for hydrogen peroxide treatment include sodium bisulfite reduction and catalase catalysis. However, these traditional methods have many drawbacks. In recent years, domestic research has focused on novel hydrogen peroxide removal agents. CN 101935947 B describes a method using a 3-5% cobalt chloride aqueous solution (pH 4-6) as a hydrogen peroxide removal agent. However, these methods cause secondary cobalt pollution, involve large water flow rates, and have short residence times, failing to achieve the desired treatment effect. Therefore, this invention discloses a novel environmentally friendly hydrogen peroxide catalytic removal agent that achieves hydrogen peroxide removal while being environmentally friendly. Summary of the Invention

[0004] The purpose of this invention is to provide a novel environmentally friendly hydrogen peroxide catalytic remover and its preparation method. This novel environmentally friendly hydrogen peroxide catalytic remover has a good hydrogen peroxide removal effect.

[0005] The technical solution adopted by the present invention to achieve the above objectives is as follows: A modified catalase, wherein the modified catalase has a fixed-support structure; the fixed-support material used in the fixed-support structure includes modified chitosan; the modified chitosan includes magnetic chitosan and its surface modification groups; the surface modification groups include at least nitro and carboxyl groups.

[0006] For the purposes of this invention, the modified chitosan is obtained by surface modification of magnetic chitosan with an anhydride substance; the anhydride substance comprises 3-nitro-1,8-naphthalenedicarboxylic anhydride.

[0007] In this invention, the modified catalase is prepared by immobilizing catalase with modified chitosan; the modified chitosan is prepared by crosslinking chitosan and Fe3O4 through emulsification to obtain magnetic chitosan, and then using 3-aminopropyltriethoxysilane and 3-nitro-1,8-naphthalenedicarboxylic anhydride as surface carboxylation modifiers.

[0008] This invention discloses a method for preparing modified catalase. Magnetic chitosan is prepared by emulsification and cross-linking of Fe3O4 and chitosan. Modified chitosan is then prepared by using 3-aminopropyltriethoxysilane and 3-nitro-1,8-naphthalenedicarboxylic anhydride as surface carboxylation modifiers. The modified chitosan is then immobilized with catalase through activation by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide. The resulting modified catalase exhibits good stability; this may be due to the effect of 3-nitro-1,8-naphthalenedicarboxylic anhydride on the surface carboxylation of chitosan. The modification of chitosan increases the number of carboxyl groups in the modified chitosan, enhancing the activity of the modified catalase. Furthermore, the catalase immobilized on the surface of the modified chitosan is more easily inactivated, while the catalase inside the modified chitosan is protected by the chitosan molecules and the cross-linked structure of 3-aminopropyltriethoxysilane and 3-nitro-1,8-naphthalenedicarboxylic anhydride, resulting in slower inactivation and thus better stability. The modified catalase is then used in the preparation of a novel environmentally friendly hydrogen peroxide catalytic removal agent, which exhibits excellent hydrogen peroxide removal performance.

[0009] Specifically, the preparation method of the above-mentioned modified chitosan includes the following steps: 1) Dissolve chitosan in glacial acetic acid solution (1-1.5wt%) to prepare a 1-1.5wt% chitosan solution. Stir and mix at room temperature for 3.5-4.5 hours, then stir at 70-75℃ for 4-4.5 hours. Filter the solution, sonicate the filtrate for 15-25 minutes, add Fe3O4 (the mass-to-volume ratio of Fe3O4 to chitosan solution is 1g:55-70mL), and sonicate for 10-15 minutes to obtain solution a. Add liquid paraffin and Tween-80 (wherein, the volume ratio of chitosan solution to liquid paraffin is...). The chitosan solution and Tween-80 solution were mixed at room temperature for 25-35 minutes (volume ratio of chitosan solution to Tween-80 solution was 1:0.2-0.35) to obtain solution b. Solution b was added to solution a above and stirred for 0.8-1.5 hours. Then, glutaraldehyde solution with a concentration of 20-25 wt% (volume ratio of chitosan solution to glutaraldehyde solution was 1:0.04-0.05) was added and reacted for 2-2.5 hours. The product was separated using a magnet and washed 3-5 times in sequence with petroleum ether, acetone, anhydrous ethanol, and deionized water. After vacuum freeze-drying, magnetic chitosan was obtained. 2) Add 3-aminopropyltriethoxysilane to N,N-dimethylformamide (the volume ratio of 3-aminopropyltriethoxysilane to N,N-dimethylformamide is 1:32-37), add the above-mentioned magnetic chitosan (the mass-volume ratio of magnetic chitosan to 3-aminopropyltriethoxysilane is 1g:1.4-1.6mL), add deionized water and DMF (the mass-volume ratio of magnetic chitosan to deionized water is 1g:8-10mL, and the mass-volume ratio of magnetic chitosan to DMF is...). The mass-to-volume ratio of the two components was 1 g: 90-105 mL. The mixture was stirred at room temperature for 3-3.5 h. Then, 3-nitro-1,8-naphthalenedicarboxylic anhydride (the mass-to-volume ratio of 3-nitro-1,8-naphthalenedicarboxylic anhydride to 3-aminopropyltriethoxysilane was 1 g: 1-1.25 mL) was added. The mixture was stirred at a constant temperature for another 3-3.5 h. The product was then separated under the action of an external magnet and washed 3-5 times with deionized water and anhydrous ethanol, respectively. Finally, the product was freeze-dried under vacuum to obtain modified chitosan.

[0010] This invention also discloses the use of the modified chitosan in the preparation of a novel environmentally friendly hydrogen peroxide catalytic removal agent.

[0011] Specifically, the preparation method of the modified catalase includes the following steps: adding 0.1 mol / L PB buffer (the mass-to-volume ratio of modified chitosan to PB buffer is 1 mg: 0.02-0.025 mL) to modified chitosan, adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (the mass-to-volume ratio of modified chitosan to 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride is 1 g: 2-2.5 mL), stirring and mixing for 30-40 min, adding N-hydroxysuccinimide (the mass-to-volume ratio of modified chitosan to N-hydroxysuccinimide is 1 g: 2-2.5 mL), separating the immobilized enzyme from the reaction solution under the action of an external magnet, washing with deionized water 3-5 times, and obtaining the modified catalase.

[0012] The present invention also discloses the use of the above-mentioned modified catalase in the preparation of a novel environmentally friendly hydrogen peroxide catalytic removal agent.

[0013] A novel environmentally friendly hydrogen peroxide catalytic removal agent, comprising the aforementioned modified catalase.

[0014] For the purposes of this invention, the aforementioned novel environmentally friendly hydrogen peroxide catalytic removal agent further comprises: a compound salt, a naturally extracted enzyme solution, and an EDTA-like compound.

[0015] For the purposes of this invention, the aforementioned composite salt comprises at least two of iron oxide, ferric sulfate, and ferric chloride.

[0016] For the purposes of this invention, the aforementioned EDTA compounds include at least two of ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetic acid, and tetrasodium ethylenediaminetetraacetic acid.

[0017] For the purposes of this invention, the above-mentioned natural extracted enzyme solution is plant catalase solution.

[0018] For the purposes of this invention, the above-mentioned natural enzyme extract is obtained by extracting from at least two of potatoes, tree bark, wheat, and carrots.

[0019] This invention also discloses a method for preparing a novel environmentally friendly hydrogen peroxide catalytic removal agent, comprising: S1. A composite salt solution is prepared by mixing a composite salt with deionized water. S2. Add an inorganic acid to the composite salt solution for oxidative polymerization to obtain a composite polymer salt; S3. Add EDTA compounds to the composite polymer salt, react fully, and adjust the pH value to obtain the EDTA composite salt system. S4. Add the naturally extracted enzyme solution and modified catalase to the above-mentioned EDTA-type complex salt system, and after full reaction, cool and mature to obtain a new type of environmentally friendly hydrogen peroxide catalytic removal agent.

[0020] Specifically, the preparation method of the above-mentioned novel environmentally friendly hydrogen peroxide catalytic removal agent includes the following steps: S1. At room temperature, place the compound salt and deionized water in a sealed container and mix thoroughly. Stir until homogeneous to obtain a compound salt solution with a concentration of 0.5-2 wt%. S2. Under a nitrogen atmosphere, add 0.1-2 wt% inorganic acid to the composite salt solution and oxidize and polymerize at 40-60℃ for 6-12 h. After the reaction is completed, filter the reactants 3-5 times with filter paper, then rinse with deionized water for 5-10 min, rinse with anhydrous ethanol for 5-10 min, and finally rinse with deionized water for 5-10 min. Dry, pulverize, and let stand for 12-24 h to obtain the composite polymer salt. S3. Add the composite polymer salt to deionized water to prepare a reaction solution with a concentration of 0.1-1.5wt%. Then, at 50℃-60℃, add EDTA compounds (2-4wt% of the reaction solution). Stir the reaction thoroughly for 0.5-2 hours and adjust the pH value to 3-5 to obtain the EDTA composite salt system. S4. Slowly add natural extract enzyme solution and modified catalase (the amount of natural extract enzyme solution added is 10-20 wt% of the EDTA complex salt system, and the amount of modified catalase added is 5-10 wt% of the EDTA complex salt system) to the EDTA complex salt system. The addition is completed within 2-6 hours. Allow the reaction to proceed fully for 8-24 hours, then raise the temperature to 40℃-60℃ and maintain the temperature for 1-4 hours. Finally, cool and mature the mixture for 12-48 hours to obtain a new type of environmentally friendly hydrogen peroxide catalytic removal agent.

[0021] For the purposes of this invention, the aforementioned inorganic acid comprises at least two of the following: concentrated sulfuric acid with a concentration of 95-98 wt%, concentrated nitric acid with a concentration of 60-70 wt%, and concentrated hydrochloric acid with a concentration of 30-35 wt%.

[0022] This invention also discloses a method for preparing a natural enzyme extract, comprising: taking at least two natural plants from potatoes, carrots, tree bark, and wheat, mixing and chopping them, placing them in a mortar, adding a phosphate buffer with a pH of 7.0-7.3 (the mass-to-volume ratio of natural plants to phosphate buffer is 1g:0.01-0.025mL), grinding into a homogenate, adding a pectinase phosphate buffer with a concentration of 0.1-0.15mol / L (wherein, the pH of the phosphate buffer used in the pectinase phosphate buffer is 7.0-7.3; the amount of pectinase phosphate buffer added is 0.01-0.05wt% of the total amount of natural plants), enzymatically hydrolyzing at 40-45℃ for 80-90min, filtering with gauze, centrifuging at 4000-5000rpm and 6-10℃ for 20-30min, collecting the supernatant, and obtaining the natural enzyme extract.

[0023] The present invention further purifies the above-mentioned natural enzyme extract by using modified Sephadex G-75 filtration chromatography.

[0024] The present invention also discloses a method for preparing modified Sephadex G-75, comprising: grafting Sephadex G-75 with 1-BOC-3,4-epoxypiperidine to obtain modified Sephadex G-75.

[0025] This invention provides a method for preparing modified Sephadex G-75, which uses 1-BOC-3,4-epoxypiperidine to graft and modify Sephadex G-75. The resulting modified Sephadex G-75 is used for the purification of natural extract enzyme solutions, which can further improve the purity of the natural extract enzyme solutions. This may be because 1-BOC-3,4-epoxypiperidine and Sephadex G-75 form an interpenetrating structure. The presence of piperidine and alkyl structures in 1-BOC-3,4-epoxypiperidine further promotes the formation of entanglement and network structures, thereby improving the purification effect.

[0026] Specifically, the preparation method of the modified Sephadex G-75 includes the following steps: Sephadex G-75 is added to DMSO (the mass-to-volume ratio of the two is 1g:8.5-9.5mL), and then DMAP and 1-BOC-3,4-epoxypiperidine are added under a nitrogen atmosphere (wherein, the mass ratio of Sephadex G-75 to DMAP is 1:0.18-0.23; the mass ratio of Sephadex G-75 to 1-BOC-3,4-epoxypiperidine is 1:0.13-0.16). The reaction is carried out at 28-32℃ for 28-35h. Then, the reaction solution is slowly added to anhydrous ethanol (the mass-to-volume ratio of Sephadex G-75 to anhydrous ethanol is 1g:40-45mL), allowed to stand, filtered, and the precipitate is added to double-distilled water (Sephadex G-75:40-45mL) at 3-5℃. The modified Sephadex G-75 was prepared by adjusting the pH to 7-8 in a mixture of G-75 and double-distilled water at a mass-to-volume ratio of 1 g: 2-2.5 mL, dialyzing in deionized water (3-5℃, 4-5 days), and freeze-drying.

[0027] The present invention also discloses the use of the modified Sephadex G-75 obtained by the above preparation method in the purification of natural extract enzyme solutions.

[0028] The beneficial effects of this invention include: This invention provides a novel environmentally friendly hydrogen peroxide catalytic remover and its preparation method. The novel environmentally friendly hydrogen peroxide catalytic remover comprises: a composite salt, a natural extracted enzyme solution, a modified catalase, and an EDTA-like compound. It exhibits excellent hydrogen peroxide removal efficiency, and the modified catalase, prepared by immobilizing catalase with modified chitosan, demonstrates good stability. Furthermore, this invention uses 1-BOC-3,4-epoxypiperidine-modified Sephadex G-75 to purify the natural extracted enzyme solution, further enhancing the hydrogen peroxide removal efficiency of the novel environmentally friendly hydrogen peroxide catalytic remover.

[0029] Therefore, the present invention provides a novel environmentally friendly hydrogen peroxide catalytic remover and its preparation method, which has a good hydrogen peroxide removal effect. Attached Figure Description

[0030] Figure 1 The modified chitosan prepared in Example 1 and the infrared spectrum test results of chitosan; Figure 2 The results of infrared spectral analysis of the modified Sephadex G-75 prepared in Example 3 are shown. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be further described in detail below with reference to specific embodiments: Example 1: A method for preparing a novel environmentally friendly hydrogen peroxide catalytic removal agent includes the following steps: S1. At room temperature, ferric oxide, ferric sulfate, ferric chloride (in a molar ratio of 1:1:1) and deionized water are placed in a sealed container and thoroughly mixed and stirred until homogeneous to obtain a composite salt solution with a concentration of 1 wt%. S2. Under a nitrogen atmosphere, 1 wt% of inorganic acid (containing 98 wt% concentrated sulfuric acid, 65 wt% concentrated nitric acid, and 32 wt% concentrated hydrochloric acid; the mass ratio of concentrated sulfuric acid, concentrated nitric acid, and concentrated hydrochloric acid is 1:2:3) was added to the composite salt solution. Oxidative polymerization was carried out at 50℃ for 8 h. After the reaction was completed, the reactants were filtered five times with filter paper, then rinsed with deionized water for 8 min, rinsed with anhydrous ethanol for 5 min, and finally rinsed with deionized water for 8 min. The mixture was then dried, pulverized, and left to stand for 20 h to obtain the composite polymer salt. S3. Add the composite polymer salt to deionized water to prepare a 1wt% solution. Then, at 55℃, add EDTA compounds (EDTA compounds include ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetic acid, and tetrasodium ethylenediaminetetraacetic acid; the molar ratio of the three added is 1:1:1). The amount of EDTA compounds added is 3wt% of the reaction solution. After stirring the reaction thoroughly for 1 hour, adjust the pH value to 4 to obtain the EDTA composite salt system. S4. Slowly add natural extract enzyme solution and modified catalase (the amount of natural extract enzyme solution added is 15wt% of the EDTA complex salt system, and the amount of modified catalase added is 8wt% of the EDTA complex salt system) to the EDTA complex salt system. The addition is completed within 4 hours, and the reaction is allowed to proceed fully for 12 hours. Then, the temperature is raised to 50℃ and the reaction is kept at a constant temperature for 2 hours. Finally, the mixture is cooled and matured for 24 hours to obtain a new type of environmentally friendly hydrogen peroxide catalytic removal agent.

[0032] A method for preparing modified catalase includes the following steps: adding 0.1 mol / L PB buffer (the mass-to-volume ratio of modified chitosan to PB buffer is 1 mg: 0.02 mL) to modified chitosan, adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (the mass-to-volume ratio of modified chitosan to 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride is 1 g: 2 mL), stirring and mixing for 30 min, adding N-hydroxysuccinimide (the mass-to-volume ratio of modified chitosan to N-hydroxysuccinimide is 1 g: 2 mL), separating the immobilized enzyme from the reaction solution under the action of an external magnet, washing 5 times with deionized water to obtain modified catalase.

[0033] The preparation method of modified chitosan includes the following steps: 1) Dissolve chitosan in glacial acetic acid solution (1wt% concentration) to prepare a 1wt% chitosan solution. Stir and mix at room temperature for 3.5 hours, then stir at 70℃ for 4 hours. Filter, sonicate the filtrate for 15 minutes, add Fe3O4 (mass-volume ratio of Fe3O4 to chitosan solution is 1g:55mL), and sonicate for 10 minutes to obtain solution a. Add liquid paraffin and Tween-80 (wherein, the volume ratio of chitosan solution to liquid paraffin is...) The chitosan solution and Tween-80 solution were mixed at room temperature for 25 minutes (volume ratio of chitosan solution to Tween-80 solution was 1:0.2) to obtain solution b. Solution b was added to solution a and stirred for 0.8 hours. Then, glutaraldehyde solution with a concentration of 25 wt% (volume ratio of chitosan solution to glutaraldehyde solution was 1:0.04) was added and reacted for 2 hours. The product was separated by a magnet and washed five times in sequence with petroleum ether, acetone, anhydrous ethanol and deionized water. After vacuum freeze-drying, magnetic chitosan was obtained. 2) 3-Aminopropyltriethoxysilane was added to N,N-dimethylformamide (the volume ratio of 3-aminopropyltriethoxysilane to N,N-dimethylformamide was 1:35), and the above-mentioned magnetic chitosan (the mass-volume ratio of magnetic chitosan to 3-aminopropyltriethoxysilane was 1 g:1.5 mL) was added. Deionized water and DMF (the mass-volume ratio of magnetic chitosan to deionized water was 1 g:8 mL, and the mass-volume ratio of magnetic chitosan to DMF was 1 g:90 mL) were added. The mixture was stirred at room temperature for 3 h. Then, 3-nitro-1,8-naphthalenedicarboxylic anhydride (the mass-volume ratio of 3-nitro-1,8-naphthalenedicarboxylic anhydride to 3-aminopropyltriethoxysilane was 1 g:1 mL) was added. The mixture was stirred at a constant temperature for another 3 h. The product was separated under the action of an external magnet, washed three times with deionized water and anhydrous ethanol, and then freeze-dried under vacuum to obtain modified chitosan.

[0034] The preparation method of the natural enzyme extract includes: taking natural plants such as potatoes, bark, wheat, and carrots (the mass ratio of potatoes, bark, wheat, and carrots is 1:1:1:1), mixing and chopping them, placing them in a mortar, adding phosphate buffer with a pH of 7.0 (the mass-volume ratio of natural plants to phosphate buffer is 1g:0.02mL), grinding into a homogenate, adding 0.1mol / L pectinase phosphate buffer (wherein, the pH of the phosphate buffer used in the pectinase phosphate buffer is 7.0; the amount of pectinase phosphate buffer added is 0.02wt% of the total amount of natural plants), enzymatically hydrolyzing at 40℃ for 90min, filtering with gauze, centrifuging at 5000rpm and 8℃ for 20min, collecting the supernatant to obtain the natural enzyme extract.

[0035] Example 2: The difference between the preparation method of a novel environmentally friendly hydrogen peroxide catalytic remover and Example 1 is that magnetic chitosan is used instead of modified chitosan.

[0036] The preparation method of magnetic chitosan is the same as step 1 in the preparation method of modified chitosan in Example 1.

[0037] Example 3: The difference between the preparation method of a novel environmentally friendly hydrogen peroxide catalytic removal agent and Example 1 is that the natural extracted enzyme solution is purified.

[0038] Methods for purifying naturally extracted enzyme solutions include: The modified Sephadex G-75 was added to double-distilled water (mass-volume ratio of 1g:20mL) and soaked. The solution was kept at 100℃ for 3 hours, cooled to room temperature, and vacuumed for 30 minutes after removing air bubbles. After sedimentation, the upper suspended particles were removed and the solution was injected into a separation tube. The natural enzyme extract was loaded onto the sample and allowed to stand until the surface of the natural enzyme extract and the modified Sephadex G-75 were in equilibrium. Elution was performed using a phosphate buffer solution with pH=7.8 at a flow rate of 1.5mL / min. The enzyme solution was collected to obtain the purified natural enzyme extract.

[0039] The preparation method of modified Sephadex G-75 includes the following steps: Sephadex G-75 is added to DMSO (mass-volume ratio of 1g:9mL), and then DMAP and 1-BOC-3,4-epoxypiperidine are added under a nitrogen atmosphere (wherein, the mass ratio of Sephadex G-75 to DMAP is 1:0.2; the mass ratio of Sephadex G-75 to 1-BOC-3,4-epoxypiperidine is 1:0.15). The reaction is carried out at 28℃ for 30h. Then, the reaction solution is slowly added to anhydrous ethanol (mass-volume ratio of Sephadex G-75 to anhydrous ethanol is 1g:40mL), allowed to stand, filtered, and the precipitate is added to double-distilled water (mass-volume ratio of Sephadex G-75 to double-distilled water is 1g:2mL) at 4℃. The pH is adjusted to 7, dialyzed in deionized water (3℃, 4d), and freeze-dried to obtain modified Sephadex G-75.

[0040] Example 4: The difference between the preparation method of a novel environmentally friendly hydrogen peroxide catalytic removal agent and Example 3 is that Sephadex G-75 is used instead of modified Sephadex G-75.

[0041] Example 5: The difference between the preparation method of a novel environmentally friendly hydrogen peroxide catalytic removal agent and Example 2 is that the natural extracted enzyme solution is purified.

[0042] The purification method for the naturally extracted enzyme solution is the same as in Example 3.

[0043] Example 6: The difference between the preparation method of a novel environmentally friendly hydrogen peroxide catalytic removal agent and Example 2 is that the natural extracted enzyme solution is purified.

[0044] The difference between the purification method of the naturally extracted enzyme solution and Example 3 is that Sephadex G-75 is used instead of modified Sephadex G-75.

[0045] Experimental example: 1. Infrared spectroscopy test The samples were analyzed using a Bruker TENSOR II Fourier Transmission Infrared Spectrometer (FT-IR), with scanning wavelengths ranging from 500 to 4000 cm⁻¹. -1 4cm resolution -1 .

[0046] The modified chitosan prepared in Example 1 and the chitosan were subjected to the above tests, and the results are as follows: Figure 1 As shown. By Figure 1 It can be seen that, compared with the infrared spectrum of chitosan, the infrared spectrum of modified chitosan is smaller in the 1400-1600 cm⁻¹ range. -1 The infrared characteristic peak of the benzene ring is present at 585 cm⁻¹; -1 The infrared characteristic peak of Fe3O4 is present at 724 cm⁻¹; -1 The presence of characteristic infrared absorption peaks for C-Si indicates that 3-aminopropyltriethoxysilane and 3-nitro-1,8-naphthalenedicarboxylic anhydride participated in the formation reaction of modified chitosan.

[0047] The modified Sephadex G-75 prepared in Example 3 and Sephadex G-75 were subjected to the above tests, and the results are as follows: Figure 2 As shown. By Figure 2 It can be seen that, compared with the infrared spectrum of Sephadex G-75, the infrared spectrum of the modified Sephadex G-75 at 1226 cm⁻¹... -1 The presence of a CN bond characteristic infrared absorption peak indicates that 1-BOC-3,4-epoxypiperidine participated in the formation reaction of modified Sephadex G-75.

[0048] 2. Catalase Immobilization Capacity Test The Coomassie Brilliant Blue method was used, with an initial catalase concentration of 9 mg / mL. The immobilization load was calculated by measuring the catalase concentration in the solution before and after immobilization.

[0049] Table 1 Results of catalase immobilization test Modified chitosan 115.4 Magnetic chitosan 75.8 The catalase immobilization of the modified chitosan and magnetic chitosan prepared in Example 1 was tested as described above, and the results are shown in Table 1. Table 1 shows that catalase was successfully immobilized on both modified chitosan and magnetic chitosan, with the immobilization amount in modified chitosan significantly increasing compared to magnetic chitosan. This may be because the carboxyl-modified chitosan increased its effective enzyme-carrying capacity, and the presence of the carboxyl group may further enhance its effective enzyme-carrying capacity.

[0050] 3. Enzyme stability test Add 0.5 g of immobilized enzyme to 50 mL of 0.05 mol / L hydrogen peroxide phosphate buffer solution. After reacting for 1 min at room temperature, remove the solution and measure the absorbance of the solution before and after the reaction at the characteristic absorption wavelength of hydrogen peroxide (240 nm). Calculate the immobilized enzyme activity using the following formula: N=[S×(D0-D1)×10 3 ] / (k×G) Where N is the enzyme activity (U / g); S is the volume of hydrogen peroxide solution (mL); D0 is the initial concentration of hydrogen peroxide (mol / L); D1 is the remaining concentration of hydrogen peroxide (mol / L); k is the reaction time (min); and G is the mass of the immobilized enzyme (g).

[0051] Free enzyme and immobilized enzyme samples were placed at 25℃ for 8 days, and enzyme activity was measured according to the method described above. The initial enzyme activity was taken as 100%, and the formula for calculating relative enzyme activity is as follows: R = (K1 / K0) × 100% Where R is the relative enzyme activity; K1 is the enzyme activity after the experiment; and K0 is the enzyme activity before the experiment.

[0052] Table 2 Results of enzyme stability test Example 1 89 Example 2 77 Free catalase 25 The modified catalase and free catalase prepared in Examples 1 and 2 were subjected to the above tests, and the results are shown in Table 2. Table 2 shows that both Examples 1 and 2 exhibited good stability compared to free catalase, indicating that free catalase is more easily inactivated. Additionally, it may be because the catalase on the modified chitosan surface is easily inactivated, while the catalase inside is more easily protected by the modified chitosan and inactivates more slowly, thus resulting in higher stability of the modified catalase.

[0053] 4. Hydrogen peroxide removal efficiency test A novel environmentally friendly hydrogen peroxide catalytic removal agent was added to a 400 mg / L hydrogen peroxide solution at a concentration of 20 mg / L. After reacting for 15 minutes at room temperature, the amount of undecomposed hydrogen peroxide was determined by iodometric titration. The hydrogen peroxide removal rate was calculated based on the change in hydrogen peroxide before and after treatment.

[0054] Table 3 Results of hydrogen peroxide removal rate test Example 1 90.5 Example 2 83.1 Example 3 98.8 Example 4 94.5 Example 5 92.7 Example 6 88.4 The novel environmentally friendly hydrogen peroxide catalytic removers prepared in Examples 1-6 were subjected to the above tests, and the results are shown in Table 3. As shown in Table 3, the hydrogen peroxide removal rate was significantly improved in Example 1 compared to Example 2, Example 3 compared to Example 5, and Example 4 compared to Example 6. This indicates that the use of chitosan modified with 3-aminopropyltriethoxysilane and 3-nitro-1,8-naphthalenedicarboxylic anhydride to prepare modified catalase, and then its application in the preparation of a novel environmentally friendly hydrogen peroxide catalytic remover, resulted in the novel environmentally friendly hydrogen peroxide catalytic remover exhibiting a good hydrogen peroxide removal effect. This may be due to the high catalase loading of the modified chitosan. The hydrogen peroxide removal rate was also improved in Example 3 compared to Example 4, and Example 5 compared to Example 6. This indicates that the use of 1-BOC-3,4-epoxypiperidine-modified Sephadex G-75 to purify plant extracts further improved the purity of the extracts. When the extracts were used to prepare the novel environmentally friendly hydrogen peroxide catalytic remover, the novel environmentally friendly hydrogen peroxide catalytic remover exhibited a better hydrogen peroxide removal effect.

[0055] The conventional techniques described in the above embodiments are existing technologies known to those skilled in the art, and therefore will not be described in detail here.

[0056] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A modified catalase, characterized in that: The modified catalase has a fixed-support structure; the fixed-support material used in the fixed-support structure includes modified chitosan; the modified chitosan includes magnetic chitosan and its surface modification groups; the surface modification groups include at least nitro and carboxyl groups; In the preparation of modified catalase, magnetic chitosan was prepared by emulsification and crosslinking of Fe3O4 and chitosan. Then, 3-aminopropyltriethoxysilane and 3-nitro-1,8-naphthalenedicarboxylic anhydride were used as surface carboxylation modifiers, with the mass-to-volume ratio of 3-nitro-1,8-naphthalenedicarboxylic anhydride to 3-aminopropyltriethoxysilane being 1 g: 1-1.25 mL, to obtain modified chitosan. The modified chitosan was then immobilized with catalase through activation by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide to obtain modified catalase. The modified chitosan is prepared by the following steps: 3-aminopropyltriethoxysilane is added to N,N-dimethylformamide, the above-mentioned magnetic chitosan is added, deionized water and DMF are added, the mixture is stirred at room temperature for 3-3.5 h, 3-nitro-1,8-naphthalenedicarboxylic anhydride is added, the mixture is stirred at constant temperature for another 3-3.5 h, the product is separated under the action of an external magnet, washed 3-5 times with deionized water and anhydrous ethanol, and then freeze-dried under vacuum to obtain the modified chitosan. The volume ratio of 3-aminopropyltriethoxysilane to N,N-dimethylformamide is 1:32-37, the mass-volume ratio of magnetic chitosan to 3-aminopropyltriethoxysilane is 1g:1.4-1.6mL, the mass-volume ratio of magnetic chitosan to deionized water is 1g:8-10mL, and the mass-volume ratio of magnetic chitosan to DMF is 1g:90-105mL.

2. An environmentally friendly hydrogen peroxide catalytic removal agent, comprising the modified catalase as described in claim 1.

3. The environmentally friendly hydrogen peroxide catalytic removal agent according to claim 2, characterized in that: The novel environmentally friendly hydrogen peroxide catalytic removal agent also includes: compound salt, natural extracted enzyme solution, and EDTA-like compounds.

4. The environmentally friendly hydrogen peroxide catalytic removal agent according to claim 3, characterized in that: The complex salt contains at least two of the following: iron oxide, iron sulfate, and iron chloride.

5. The environmentally friendly hydrogen peroxide catalytic removal agent according to claim 3, characterized in that: The natural enzyme extract is obtained from at least two of the following: potatoes, tree bark, wheat, and carrots.

6. The environmentally friendly hydrogen peroxide catalytic removal agent according to claim 3, characterized in that: The EDTA compounds include at least two of ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetic acid, and tetrasodium ethylenediaminetetraacetic acid.

7. The preparation method of the environmentally friendly hydrogen peroxide catalytic removal agent according to claim 2, comprising: S1. A composite salt solution is prepared by mixing a composite salt with deionized water. S2. Add an inorganic acid to the composite salt solution for oxidative polymerization to obtain a composite polymer salt; S3. Add EDTA compounds to the composite polymer salt, react fully, and adjust the pH value to obtain the EDTA composite salt system. S4. Add the natural extracted enzyme solution and modified catalase to the above-mentioned EDTA-type complex salt system, react fully, cool and mature to obtain a new type of environmentally friendly hydrogen peroxide catalytic removal agent. The natural enzyme extract solution was purified by filtration chromatography using modified Sephadex G-75. The preparation method of modified Sephadex G-75 includes: adding Sephadex G-75 to DMSO, then adding DMAP and 1-BOC-3,4-epoxypiperidine under a nitrogen atmosphere, reacting at 28-32℃ for 28-35 h, then slowly adding the reaction solution to anhydrous ethanol, allowing it to stand, filtering, adding the precipitate to double-distilled water at 3-5℃, adjusting the pH to 7-8, dialyzing in deionized water at 3-5℃ for 4-5 days, and freeze-drying to obtain modified Sephadex G-75. The mass-to-volume ratio of Sephadex G-75 to DMSO is 1 g: 8.5-9.5 mL; the mass-to-volume ratio of Sephadex G-75 to DMAP is 1: 0.18-0.23; the mass-to-volume ratio of Sephadex G-75 to 1-BOC-3,4-epoxypiperidine is 1: 0.13-0.16; the mass-to-volume ratio of Sephadex G-75 to anhydrous ethanol is 1 g: 40-45 mL; and the mass-to-volume ratio of Sephadex G-75 to double-distilled water is 1 g: 2-2.5 mL.

8. The preparation method of the environmentally friendly hydrogen peroxide catalytic removal agent according to claim 7, characterized in that: The concentration of the composite salt solution in step S1 is 0.5-2 wt%.

9. The preparation method of the environmentally friendly hydrogen peroxide catalytic removal agent according to claim 7, characterized in that: The pH value in step S3 is 3-5.

10. The use of the modified catalase according to claim 1 in the preparation of an environmentally friendly hydrogen peroxide catalytic removal agent.

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