Application of enzyme-like nano-material activated peroxide in removal of microcystis
CuO-CeO2 activation peroxide destroys algae cells and produces reactive oxygen free radicals, solving the problem of easy inactivation of natural proteases, and achieving efficient and widely applicable algae bloom control effects.
Patent Information
- Application Number
- CN202510598291.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-09
- Publication Date
- 2025-08-15
AI Technical Summary
Existing natural proteases are prone to inactivate under harsh catalytic conditions and are not easy to store for a long time, resulting in high cost, slow performance and easy secondary pollution, making it difficult to apply on a large scale.
CuO-CeO2 activated peroxides (such as peracetic acid) are used to remove microcystis, use its peroxidase-like activity to destroy algal cells, produce reactive oxygen free radicals, attack algal cell membranes and metabolic systems, and achieve efficient removal.
In the range of pH 3 to 11, CuO-CeO2 activated peroxide can efficiently remove microcystis aeruginosa, with a removal rate of up to 100%, and has a wide range of applicable conditions.
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Figure CN120479442A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of environmentally friendly water treatment, and in particular to application of enzyme-like nanomaterials to activate peroxides in removing microcystis. Background Art
[0002] As the greenhouse effect intensifies, the incidence, scope, intensity, and economic losses of cyanobacterial blooms have increased. Controlling cyanobacterial blooms through water treatment technologies has become a major research priority both domestically and internationally. Traditional bloom control methods often suffer from high costs, slow effectiveness, and the potential for secondary pollution, making them difficult to implement on a large scale in practical projects. In recent years, enzyme-catalyzed water treatment methods have garnered significant attention due to their high substrate specificity, efficient and specific catalytic activity, and environmental friendliness. However, traditional natural proteases can experience reduced or even inactivated enzymatic activity under harsh catalytic conditions (such as extreme pH and high temperatures). Furthermore, natural proteases are difficult to store for long periods of time, with their activity decreasing with increasing storage time, ultimately leading to complete loss of activity. Summary of the Invention
[0003] In order to solve the problem that existing natural proteins have harsh catalytic conditions and are difficult to store for a long time, the purpose of the present invention is to provide an enzyme-like nanomaterial for use in activating peroxides in removing Microcystis.
[0004] The technical solution of the present invention to solve the above technical problems is as follows: providing an application of CuO-CeO2 activated peroxide in removing Microcystis.
[0005] On the basis of the above technical solution, the present invention can also be improved as follows:
[0006] Furthermore, the amount of CuO-CeO2 per liter of the algae suspension containing Microcystis is greater than 0 mg; preferably, the amount of CuO-CeO2 per liter of the algae suspension containing Microcystis is 50 mg to 250 mg.
[0007] Furthermore, the amount of peroxide used in each liter of the algae suspension containing Microcystis is 0.6 mM to 1.4 mM; preferably, the amount of peroxide used in each liter of the algae suspension containing Microcystis is 0.8 mM to 1.4 mM.
[0008] Furthermore, the initial algae density of Microcystis in the algae suspension containing Microcystis is: (OD 680 -0.1236) / 0.118×10 6 cells / mL, where OD 680 It is 0.2~1.0.
[0009] Furthermore, the pH value of the algae suspension containing Microcystis is 3-11, and the concentration of natural organic matter in the algae suspension containing Microcystis is in the range of 0-10 mg / L.
[0010] Furthermore, the Microcystis is Microcystis aeruginosa.
[0011] Furthermore, the peroxide is an organic peroxide.
[0012] Furthermore, the organic peroxide is peracetic acid.
[0013] Further, the preparation of CuO-CeO2 comprises the following steps:
[0014] Step 1, dissolving Ce(NO3)3·6H2O in deionized water, then adding Cu(NO3)2·3H2O and ammonia water, stirring and dissolving to obtain a precursor solution;
[0015] Step 2: The precursor solution undergoes a hydrothermal reaction, and CuO-CeO2 is obtained after the reaction is completed.
[0016] Furthermore, the molar ratio of Cu(NO3)2·3H2O and Ce(NO3)3·6H2O is 1:2 to 2:1;
[0017] The ammonia solution is 25% ammonia water, and the amount of ammonia water used is 600 μL;
[0018] The temperature of the hydrothermal reaction is 180° C., and the condition of the hydrothermal reaction is 6 h.
[0019] The present invention has the following beneficial effects:
[0020] The present invention uses CuO-CeO2 to activate PAA (peracetic acid) to remove Microcystis aeruginosa, which has high efficiency and a wide range of applicable conditions. It can remove Microcystis aeruginosa in algae suspensions with a pH value of 3 to 11, algae suspensions containing natural organic matter, and water bodies with different algae densities, and its removal rate can be as high as 100% under acidic conditions.
[0021] The mechanism of the present invention for removing Microcystis aeruginosa by activating PAA with CuO-CeO2 is as follows: CuO-CeO2 with peroxidase-like activity can effectively activate typical peroxides (such as peracetic acid), destroy the peroxy bonds between peracetic acid, and generate a large number of reactive oxygen free radicals (mainly singlet oxygen, as well as some hydroxyl free radicals, superoxide free radicals and organic free radicals). These substances have extremely strong oxidizing properties and can remove organic matter attached to the surface of algae cells, reducing the stability of algae cells, and then attacking the algae cell membrane, destroying its permeability to facilitate the entry of more free radicals into the algae cells, and then attacking the metabolic system, antioxidant system and photosynthesis system of the algae cells, ultimately leading to the death of the algae cells, thereby achieving the purpose of algae removal.
[0022] In addition, the reaction temperature and amount of ammonia water used in the preparation of CuO-CeO2 in the present invention ensure the formation of CuO-CeO2 enzyme nanomaterials, and avoid the formation of other products caused by excessive or insufficient ammonia water use or too high or too low reaction temperature. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 X-ray diffraction patterns, wherein (a) is the X-ray diffraction pattern of CuO, CeO2 and CuO-CeO2, and (b) is the X-ray diffraction pattern of CuO-CeO2 with different molar ratios of CuO and CeO2;
[0024] Figure 2 Figures 3 and 4 are morphology images and CuO-CeO2 composition images, where (a) is a scanning electron microscope image of CuO, (b) is a scanning electron microscope image of CeO2, (c) is a scanning electron microscope image of CuO-CeO2, (d), (e), (f) and (g) are energy scattering spectra of CuO-CeO2, and (h) and (i) are transmission electron microscope morphology images of CuO-CeO2.
[0025] Figure 3 The X-ray photoelectron spectrum of CuO-CeO2 is shown in Figure 1. (a) is the total spectrum, (b) is the O1s spectrum, (c) is the Ce 3d spectrum, and (d) is the Cu 2p spectrum.
[0026] Figure 4 N2 adsorption and desorption curves of CuO, CeO2 and CuO-CeO2;
[0027] Figure 5 The color reaction results of CuO-CeO2 and the maximum absorption peak fitting diagram;
[0028] Figure 6 Figure 2 is a diagram of the steady-state kinetic behavior of CuO-CeO2 and the substrate TMB during the reaction process; (a) is a Michaelis-Menten curve of V0 changing with TMB concentration under the action of CuO-CeO2; (b) is the corresponding double reciprocal graph;
[0029] Figure 7 This is the effect diagram of CuO-CeO2 activated peroxide removing Microcystis aeruginosa;
[0030] Figure 8 This is a diagram showing the effect of PAA activated by CuO-CeO2 with different molar ratios of CuO and CeO2 on the removal of Microcystis aeruginosa;
[0031] Figure 9 The effect diagram of removing Microcystis aeruginosa by activating PAA with different addition amounts of CuO-CeO2;
[0032] Figure 10 This is the effect diagram of removing Microcystis aeruginosa by activating different dosages of PAA with CuO-CeO2;
[0033] Figure 11 The figure shows the effect of CuO-CeO2 activating PAA in removing Microcystis aeruginosa in algae suspensions with different pH values.
[0034] Figure 12 The figure shows the effect of PAA activated by CuO-CeO2 in removing Microcystis aeruginosa in algae suspensions containing different concentrations of natural organic matter.
[0035] Figure 13 Effect of PAA activated by CuO-CeO2 on the removal of Microcystis aeruginosa in algal suspensions with different initial algal densities. DETAILED DESCRIPTION
[0036] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples are only used to explain the present invention and are not intended to limit the scope of the invention. In the embodiments, if specific conditions are not specified, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.
[0037] Example
[0038] Example 1:
[0039] The preparation method of CuO-CeO2 enzyme nanomaterials comprises the following steps:
[0040] Step 1. At room temperature, dissolve Ce(NO3)3·6H2O in deionized water and stir. During the stirring process, add Cu(NO3)2·3H2O and 600μL of 25% ammonia water, and continue stirring to obtain a precursor solution; wherein the molar ratio of Cu(NO3)2·3H2O to Ce(NO3)3·6H2O is 2:1.
[0041] Step 2: Transfer the precursor solution to a reactor and react at 180° C. for 6 h. Then, cool, centrifuge, wash, and dry to obtain CuO-CeO2 powder.
[0042] Example 2
[0043] The preparation method of the CuO-CeO2 enzyme nanomaterial in this embodiment is the same as that in Example 1, except that the molar ratio of Cu(NO3)2·3H2O and Ce(NO3)3·6H2O is 1:1.
[0044] Example 3
[0045] The preparation method of the CuO-CeO2 enzyme nanomaterial in this embodiment is the same as that in Example 1, except that the molar ratio of Cu(NO3)2·3H2O and Ce(NO3)3·6H2O is 1:2.
[0046] Test analysis:
[0047] 1. Structure and performance analysis of CuO-CeO2 enzyme nanomaterials
[0048] (1) The CuO-CeO2 enzyme nanomaterials prepared in Examples 1 to 3 were subjected to X-ray diffraction analysis. The test results are as follows: Figure 1 shown.
[0049] Figure 1 X-ray diffraction patterns, wherein (a) is the X-ray diffraction pattern of CuO, CeO2 and CuO-CeO2, and (b) is the X-ray diffraction pattern of CuO-CeO2 with different molar ratios of CuO and CeO2 (i.e., the X-ray diffraction patterns of CuO-CeO2 prepared in Examples 1 to 3). Figure 1 It can be seen that in Figure 1 In Figure (a), the characteristic peaks at 28.5°, 47.4° and 56.3° correspond to the (111), (220) and (311) crystal planes of CeO2, respectively, while the two sharp characteristic peaks at 35.6° and 38.7° are attributed to CuO, and CuO-CeO2 has corresponding characteristic peaks at 28.5°, 47.4°, 56.3°, 35.6° and 38.7°. Figure 1 As can be seen from Figure (b), the characteristic peaks of CuO-CeO2 gradually increase with the increase of the molar ratio of CuO to CeO2 in CuO-CeO2 (i.e., the characteristic peaks of CuO-CeO2 gradually increase with the increase of the molar ratio of Cu(NO3)2·3H2O and Ce(NO3)3·6H2O during the preparation of CuO-CeO2).
[0050] (2) CuO, CeO2 and the CuO-CeO2 prepared in Example 3 were subjected to scanning electron microscopy analysis. The test results are as follows: Figure 2 As shown, Figure 2 Figure (a) is a scanning electron microscope image of CuO, Figure (b) is a scanning electron microscope image of CeO2, Figure (c) is a scanning electron microscope image of CuO-CeO2, Figures (d), (e), (f) and (g) are energy scattering spectra of CuO-CeO2, and Figures (h) and (i) are transmission electron microscope morphology images of CuO-CeO2.
[0051] from Figure 2As can be seen from Figure (a), the monomer CuO is a flake structure of about 1 μm in length; and from Figure (b), it can be seen that CeO2 is in the form of extremely small nanoparticles; and from Figure (c), it can be seen that the composite CuO-CeO2 presents both flake-like CuO and granular CeO2 structures, indicating that CuO-CeO2 is formed by a composite of CuO and CeO2. In addition, Figure 2 From Figures (d), (e), (f) and (g), we can see that Cu, Ce and O elements are evenly distributed on the surface of CuO-CeO2. Figure 2 It can be seen from Figures (h) and (i) that the CuO-CeO2 surface has lattice structures belonging to both CuO and CeO2. Based on this, Figure 1 and Figure 2 It can be seen that the present invention confirms from the perspective of crystal structure and micromorphology that CuO-CeO2 is a composite of CuO and CeO2, which shows that the present invention has successfully prepared CuO-CeO2 enzyme nanomaterials.
[0052] (3) The CuO-CeO2 prepared in Example 3 was subjected to X-ray photoelectron spectroscopy analysis. The test results are shown in Figure 3 ,in, Figure 3 Figure (a) is the overall spectrum, Figure (b) is the O1s energy spectrum; Figure (c) is the Ce 3d energy spectrum; and Figure (d) is the Cu 2p energy spectrum.
[0053] from Figure 3 It can be seen that the prepared CuO-CeO2 contains only Cu, Ce and O elements, and the change of its peak position indicates that the composite of CuO and CeO2 promotes the 3+ / Ce 4+ With Cu + / Cu 2+ The interaction between them is beneficial to enhancing the catalytic activation performance of the material. At the same time, this also means that CuO and CeO2 in CuO-CeO2 are not simply mixed, but form a composite material with strong interaction force, further proving that CuO-CeO2 is formed by a composite of CuO and CeO2.
[0054] (4) N2 adsorption and desorption test
[0055] The N2 adsorption and desorption tests were performed on CuO, CeO2 and the CuO-CeO2 prepared in Example 3 using a multi-channel gas adsorption analysis system (the equipment model used in the test was Tristar II 3020). The test results are detailed in Figure 4 .
[0056] from Figure 4It can be seen that CuO-CeO2 has the largest adsorption capacity, which means that the composite material CuO-CeO2 has better adsorption performance.
[0057] (5) Test of peroxidase-like activity of CuO-CeO2
[0058] The test consists of the following steps:
[0059] Step 1: Using 3,3',5,5'-tetramethylbenzidine (TMB) as an enzyme labeling reagent, acetate buffer (pH = 4.0), H2O2, TMB and the CuO-CeO2 prepared in Example 3 were added to a test tube in sequence, and then reacted in a 37°C water bath for 10 minutes.
[0060] Step 2: Based on step 1, observe the color reaction. When the solution turns blue, use a UV spectrophotometer to verify whether the maximum absorption peak of the mixed solution appears near 652 nm.
[0061] Step 3: Experiments were conducted using different concentrations of TMB as substrates. 2.1 mL of acetate buffer (0.1 M, pH = 4.0) and 0.3 mL of H2O2 solution (final concentration was 1 mM) were taken, and different concentrations of TMB solution (concentrations were 0.05 mM, 0.1 mM, 0.2 mM, 0.5 mM, 1.0 mM and 2.0 mM) were added. Then, a constant amount of 0.3 mL of CuO-CeO2 suspension (mother liquor concentration was 0.1 mg / mL) was added, and the mixture was reacted in a 37°C water bath for 10 min.
[0062] Step 4: Use a UV spectrophotometer to measure the absorbance at 652 nm and calculate the value according to the formula Calculate K m and v max (where K m represents the Michaelis constant in steady-state kinetics. Its size is related to the affinity of the nanozyme to the substrate. The smaller the value, the greater the affinity. max represents the maximum reaction rate, M·s-1; v0 represents the concentration of ox-TMB produced per unit time, M·s-1. ) The steady-state kinetic behavior of CuO-CeO2 and substrate TMB during the reaction was evaluated.
[0063] The results of the peroxidase-like activity test of CuO-CeO2 are detailed in Figure 5 and Figure 6 ,in, Figure 5 The color reaction results of CuO-CeO2 and the maximum absorption peak fitting diagram; Figure 6 This is the steady-state kinetic behavior diagram of CuO-CeO2 and substrate TMB during the reaction process. Figure 6Figure (a) is the Michaelis-Menten curve of v0 changing with TMB concentration under the action of CuO-CeO2; Figure (b) is the corresponding double reciprocal graph.
[0064] from Figure 5 It can be seen that CuO-CeO2 activated hydrogen peroxide can turn TMB into a clear blue liquid with a maximum absorption peak at 652nm. Figure 6 It can be seen that the R of the Michaelis-Menten fitting curve is 2 =0.996, which proves that CuO-CeO2 has peroxidase-like activity and high affinity for the substrate.
[0065] 2. Test on the effect of CuO-CeO2 enzyme nanoparticles on algae removal
[0066] (1) Test on the effect of CuO-CeO2 activated peroxide in removing Microcystis aeruginosa. The test was as follows: First, a suspension of Microcystis aeruginosa with an absorbance of about 0.8 at 680 nm was prepared using BG-11 culture medium (the initial algae density in the algae suspension was 5.73×10 6 cells / mL, the pH of the algal suspension was 10), and then the CuO-CeO2 powder prepared in Example 3 (150 mg / L) was added, and 1.2 mM PAA (or 1.2 mM H2O2) was added dropwise to carry out the removal of Microcystis aeruginosa test.
[0067] The test results are as follows Figure 7 As shown, from Figure 7 It can be seen that CuO-CeO2 activated PAA (peracetic acid) has the best effect in removing Microcystis aeruginosa, and it can remove almost 100% of Microcystis aeruginosa in 180 minutes.
[0068] (2) Test on the effect of PAA activated by CuO-CeO2 with different molar ratios of CuO and CeO2 on removing Microcystis aeruginosa. The test was carried out using the test method described in (1), with the difference that when CuO-CeO2 was prepared, the molar ratios of Cu(NO3)2·3H2O and Ce(NO3)3·6H2O were 2:1, 1:1 and 1:2, respectively, thus forming CuO-CeO2 with molar ratios of CuO and CeO2 of 2:1, 1:1 and 1:2, respectively.
[0069] The test results are detailed in Figure 8 ,from Figure 8 It can be seen that after 180 minutes of reaction, the algae removal rate of CuO-CeO2 with a molar ratio of CuO and CeO2 of 1:2 is 98.7%, the algae removal rate of CuO-CeO2 with a molar ratio of 1:1 is 75.2%, and the algae removal rate of CuO-CeO2 with a molar ratio of 2:1 is 69.1%.
[0070] (3) Test on the effect of different addition amounts of CuO-CeO2 on PAA activation in removing Microcystis aeruginosa. This test was carried out using the method described in (1), with the difference that the addition amounts of CuO-CeO2 were 50 mg / L, 100 mg / L, 150 mg / L, 200 mg / L and 250 mg / L, respectively.
[0071] The test results are detailed in Figure 9 ,from Figure 9 It can be seen that as the input of CuO-CeO2 increases from 50 mg / L to 150 mg / L, the degradation rate of chlorophyll a also increases from 54.4% to 97.9%, but when the input continues to increase to 250 mg / L, the algae removal efficiency remains stable.
[0072] (4) Test on the effect of different dosages of PAA activated by CuO-CeO2 on removing Microcystis aeruginosa. The test was conducted using the method described in (1), except that the dosages of PAA were 0.6 mM, 0.8 mM, 1.0 mM, 1.2 mM and 1.4 mM, respectively.
[0073] The test results are as follows Figure 10 As shown, from Figure 10 It can be seen that with the increase of PAA input, the algae removal rate gradually increases, but when the PAA input reaches 1.4 mM, its algae removal efficiency is very close to that of 1.2 mM (both are about 98.5%), which shows that 1.2 mM is the optimal PAA input.
[0074] (5) Test on the effect of CuO-CeO2 activated PAA on the removal of Microcystis aeruginosa in algae suspensions with different pH values. The test was carried out using the method described in (1), except that the pH values of the algae suspensions were 3, 5, 7, 10 and 11, respectively. The test results are detailed in Figure 11 .
[0075] from Figure 11 It can be seen that CuO-CeO2 exhibits good algae removal performance in a wide pH range (except strong alkaline conditions), and its algae removal effect is particularly outstanding under acidic conditions (pH value of 3 or 5), and all algae cells can be removed in 90 minutes.
[0076] (6) Test on the effect of CuO-CeO2 activated PAA on the removal of Microcystis aeruginosa in algae suspensions containing different concentrations of natural organic matter. The test was carried out using the method described in (1), with the difference that the algae suspension contained natural organic matter humic acid (HA) or fulvic acid (FA), where the concentrations of HA were 5 mg / L and 10 mg / L, respectively, and the concentrations of FA were 5 mg / L and 10 mg / L, respectively. The test results are detailed in Figure 12 shown.
[0077] from Figure 12 It can be seen that even when the concentration of HA or FA was increased to 10 mg / L, the degradation rate of chlorophyll a in the algae suspension system was still higher than 93.2%, maintaining at a high level.
[0078] (7) Test on the effect of CuO-CeO2 activated PAA in removing Microcystis aeruginosa in algae suspension with different initial algae densities. The test was carried out by the method described in (1), except that: initial algae density = (OD 680 -0.1236) / 0.118cells / mL(OD 680 represents the absorbance of the sample at 680 nm), OD 680 They are 0.2, 0.4, 0.6, 0.8 and 1.0 respectively; see the test results for details. Figure 13 .
[0079] from Figure 13 It can be seen that the use of CuO-CeO2 activated PAA to remove aeruginosa microalgae is applicable to different algae densities, that is, the technical solution of the present invention has a certain universal applicability to water bodies with different algae densities.
[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. Application of CuO-CeO2 activated peroxide in the removal of Microcystis.
2. The use according to claim 1, characterized in that The amount of CuO-CeO2 used in each liter of microcystis-containing algae suspension is greater than 0 mg.
3. The use according to claim 1, characterized in that The amount of peroxide used in each liter of microcystis-containing algae suspension is 0.6 mM to 1.4 mM.
4. The use according to claim 1, characterized in that The initial algae density of the Microcystis in the algae suspension containing Microcystis is: (OD 680 -0.1236) / 0.118×10 6 cells / mL, where OD 680 It is 0.2~1.
0.
5. The use according to claim 1, characterized in that The pH value of the algae suspension containing Microcystis is 3-11, and the concentration range of natural organic matter in the algae suspension containing Microcystis is 0-10 mg / L.
6. The use according to any one of claims 1 to 5, characterized in that: The microcystis is Microcystis aeruginosa.
7. The use according to claim 3, characterized in that The peroxide is an organic peroxide.
8. The use according to claim 7, characterized in that The organic peroxide is peracetic acid.
9. The use according to claim 2, characterized in that The preparation of the CuO-CeO2 comprises the following steps: Step 1, dissolving Ce(NO3)3·6H2O in deionized water, then adding Cu(NO3)2·3H2O and ammonia water, stirring and dissolving to obtain a precursor solution; Step 2: The precursor solution undergoes a hydrothermal reaction, and CuO-CeO2 is obtained after the reaction is completed.
10. The use according to claim 9, characterized in that The molar ratio of Cu(NO3)2·3H2O and Ce(NO3)3·6H2O is 1:2 to 2:1; The ammonia water is 25% ammonia water, and the amount of the ammonia water used is 600 μL; The temperature of the hydrothermal reaction is 180° C., and the condition of the hydrothermal reaction is 6 hours.