A composite algae-removing material and its application

Abstract

The present invention provides a composite algae removal material, which is composed of montmorillonite-loaded chitosan nanofibers and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres; the montmorillonite-loaded chitosan nanofibers and the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres are respectively mixed with water to prepare a montmorillonite-loaded chitosan nanofiber solution and a polyethylene glycol-grafted Ag-loaded GO / CNC microsphere solution, and the two solutions are successively sprayed on the surface of algae to remove the algae. The algae removal material is composed of montmorillonite-loaded chitosan nanofibers and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres. The two algae removal materials are successively added to the algae-containing water body, and through synergy, the algae removal effect is improved.

Description

Technical Field

[0001] The present invention relates to the field of algae control and treatment, and particularly relates to a composite algae removal material and its application. Background Art

[0002] In recent years, the frequency, intensity, and scope of harmful algal blooms (HABs) have been increasing worldwide, and the economic and ecological losses caused to marine ecosystems, aquaculture, and tourism have become increasingly serious. This highlights the importance of finding efficient and environmentally friendly methods for preventing and controlling HABs. The principle of emergency treatment of HABs is to reduce the density of harmful algal bloom cells in water through certain technical means, thereby reducing their harm. Some countries and regions with frequent HABs have conducted extensive research on governance measures for HABs and explored some emergency treatment technologies and measures. The prevention and control measures for HABs generally include direct measures and indirect measures. Indirect measures include removing fish cages from the HAB outbreak area and stirring seawater through measures such as aeration to dilute the algal cell density. However, there are currently no effective measures to deal with the poisoning of fish and shellfish by toxic HAB organisms. Direct strategies include using physical, chemical, and biological methods to control HABs. The chemical method is to directly kill HAB organisms using chemical agents or to precipitate algal cells from water through a flocculation method. The principle of the direct killing method is mainly through a killing effect, such as using inorganic killing agents (such as copper sulfate, hydrogen peroxide, chlorine, sodium hypochlorite, sodium percarbonate, and ozone) and organic algicides (such as HDTMA, Sophorolipid, and Aponin), to cause cell death. Generally, these methods have the advantages of quick results, convenient storage, transportation, and operation, but some methods have significant disadvantages. For example, most of the chemical agent methods used are toxic substances, and these substances generally do not have specificity and have a great impact on non-harmful algal bloom organisms. In addition, the lysis of toxic algae caused by chemical killing methods will cause toxins to enter the water body. The coagulant precipitation method uses flocculants such as inorganic coagulants, surfactants, and polymer coagulants to coagulate and precipitate harmful algal bloom organisms. Inorganic coagulants are mainly compounds of aluminum or iron, such as aluminum sulfate and ferric chloride. Polymer flocculants include inorganic polymer flocculants and organic polymer flocculants. Positively charged surfactants and polymer coagulants are the most effective for harmful algal bloom organisms, but the high salinity of seawater generally greatly reduces their coagulation effect. The coagulant precipitation method is effective when harmful algal bloom organisms are dense, has a short action time, and has a smaller impact on non-harmful algal bloom organisms than the direct killing method. However, there are still some disadvantages in practical applications, such as difficulty in large-scale on-site application. Summary of the Invention

[0003] Technical problem to be solved: The objective of the present invention is to provide a composite algae removal material, which is composed of montmorillonite-loaded chitosan nanofibers and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres. By adding the two algae removal materials to the algae-containing water successively and through their synergistic effect, the algae removal effect is improved.

[0004] Technical solution: A composite algae removal material, which is composed of montmorillonite-loaded chitosan nanofibers and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

[0005] Preferably, the preparation method of the montmorillonite-loaded chitosan nanofibers includes the following steps:

[0006] S11. Add ferric chloride hexahydrate, sodium acetate, and polyethylene glycol to ethylene glycol, stir and mix evenly, then add cation-modified nano-montmorillonite and heat for reaction to obtain magnetic montmorillonite;

[0007] S12. Dissolve chitosan in acetic acid solution to obtain a chitosan solution with a concentration of 5-8 wt%;

[0008] S13. Add the magnetic montmorillonite prepared in step S11 to the chitosan solution, prepare nanofiber bundles by electrospinning, cut the nanofiber bundles into 0.5-2 mm, and then perform ultrasonic dispersion in hydrochloric acid solution to obtain montmorillonite-loaded chitosan nanofibers. Preferably, in step S11, the mass-volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite, and ethylene glycol is 80-120 g: 250-350 g: 65-85 g: 25-35 g: 3000 mL, the heating reaction temperature is 180-230 °C, and the time is 6-12 h. Preferably, in step S13, the concentration of magnetic montmorillonite in the chitosan solution is 3-6 wt%, the concentration of hydrochloric acid solution is 0.01-0.1 mol / L, the ultrasonic power is 300-500 W, and the dispersion time is 100-300 min.

[0009] Preferably, the preparation method of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres includes the following steps:

[0010] S21. Dissolve cellulose in a sodium hydroxide / urea / water system to obtain a cellulose solution;

[0011] S22. Add graphene oxide to water, ultrasonically disperse evenly, and then add it to the cellulose solution to obtain a GO / CNC composite solution;

[0012] S23. Add the GO / CNC composite solution to liquid paraffin containing Span80 under stirring conditions, then dropwise add dilute hydrochloric acid to make the solution layer, and collect the lower-layer GO / CNC microspheres;

[0013] S24. Add the GO / CNC microspheres to a 0.2 - 0.6 mol / L silver nitrate solution. After sufficient stirring, filter to obtain the Ag⁺-loaded GO / CNC microspheres;

[0014] S25. Add the Ag⁺-loaded GO / CNC microspheres to a 0.1 - 0.5 mol / L trisodium citrate solution, and heat for reaction to obtain the Ag-loaded GO / CNC microspheres;

[0015] S26. Add the Ag-loaded GO / CNC microspheres and citric acid with a mass ratio of 2 - 3:1 to water, add sodium hydroxide to adjust the pH of the solution to 3, let it stand at room temperature for 10 - 15 h, then dry at low temperature. After drying, carry out an esterification reaction to obtain the esterified Ag-loaded GO / CNC microspheres;

[0016] S27. Add the esterified Ag-loaded GO / CNC microspheres to an aqueous solution of polyethylene glycol, and add stannous octoate, then heat for reaction to obtain the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

[0017] Preferably, in step S23, the stirring speed is 400 - 800 r / min and the stirring time is 2 - 6 h.

[0018] Preferably, in step S26, the temperature of the esterification reaction is 120 - 160 °C and the time is 2 - 3 h.

[0019] Preferably, in step S27, the mass ratio of the esterified Ag-loaded GO / CNC microspheres to polyethylene glycol is 1:10 - 20, the molecular weight of polyethylene glycol is 5000 - 8000, the temperature of the heating reaction is 80 - 100 °C, and the time is 6 - 10 h.

[0020] Application of the above composite algae removal material: Mix the montmorillonite-loaded chitosan nanofibers and the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres with water respectively to prepare a montmorillonite-loaded chitosan nanofiber solution and a polyethylene glycol-grafted Ag-loaded GO / CNC microsphere solution, and spray the two solutions onto the surface of the algae in sequence to remove the algae.

[0021] Preferably, the dosage of the algae removal material is as follows: the dosage of the montmorillonite-loaded chitosan nanofibers is 10 - 15 g per cubic meter of water body, and the dosage of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres is 5 - 10 g per cubic meter of water body.

[0022] Beneficial effects: The algae removal material of the present invention has the following advantages:

[0023] 1. The algae removal material in the present invention is composed of two parts, one of which is montmorillonite-loaded chitosan nanowires, which is used as a flocculation and sedimentation material and plays a role in flocculation and sedimentation, and the other component is polyethylene glycol-grafted Ag-loaded GO / CNC microspheres as a bactericidal adsorption material and plays a bactericidal role;

[0024] 2. In the present invention, cation-modified montmorillonite is selected, and magnetic materials are loaded between the interlayers of the cation-modified montmorillonite. The modified montmorillonite is then added to the chitosan spinning solution, and nanofiber bundles are prepared by electrostatic spinning. The fiber bundles are dispersed by ultrasonic dispersion to obtain nanofibers with an aspect ratio. The nanofibers loaded with montmorillonite can play a bridging role, which is beneficial to improving the algae removal efficiency of algae bloom organisms. The chitosan is also positively charged by acid treatment, so the montmorillonite-loaded chitosan nanofibers are positively charged as a whole, and can also have an "electrical neutralization" effect between negatively charged algae cells, and the algae removal efficiency is greatly improved. The clay in the present invention also has a certain magnetic property, which is convenient for the separation and filtration of the clay in the later stage.

[0025] 3. After the algaecide flocculates the algae, the algae will undergo a decay process. If the algae decay quickly, it may cause a sharp drop in dissolved oxygen in the water, thereby affecting the survival of other organisms in the water. The decaying algae will also release free nutrients, such as nitrogen and phosphorus. These free nutrients may become the basis for the growth of a new generation of algae, thereby promoting the re-emergence of algae. The algaecide material of the present invention also contains polyethylene glycol grafted Ag-loaded GO / CNC microspheres. The cellulose spheres themselves have a porous structure, and the graphene oxide and silver contained in the microspheres can synergistically kill bacteria, and at the same time can adsorb free nutrients to prevent secondary outbreaks of algae;

[0026] 4. The prepared montmorillonite-loaded chitosan nanowires and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres are separately prepared into solutions and added into water bodies successively. This is because after the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres are prepared into aqueous solutions, the long chains of polyethylene glycol on the surface of the microspheres are opened, and the long chains can produce certain cross-linking and entanglement with the montmorillonite-loaded chitosan nanowires. When algae settle, the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres will also settle, increasing the adsorption effect and reducing the risk of algae outbreak again. At the same time, when the montmorillonite-loaded chitosan nanowires and the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres are cross-linked and entangled in the water body, the surface of the water body is equivalent to forming a barrier film, which affects its photosynthesis and accelerates the death of the algae. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with embodiments, which are explanations of the present invention and are not limited to the following embodiments:

[0028] Example 1

[0029] A composite algae removal material, which is composed of montmorillonite-loaded chitosan nanofibers and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres;

[0030] Among them, the preparation method of the montmorillonite-loaded chitosan nanofibers includes the following steps:

[0031] S11. Add ferric chloride hexahydrate, sodium acetate and polyethylene glycol to ethylene glycol, stir and mix evenly, then add cation-modified nano-montmorillonite and heat for reaction. The mass-volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite and ethylene glycol is 80g: 250g: 65g: 25g: 3000mL. The heating reaction temperature is 180 °C and the time is 12h to obtain magnetic montmorillonite; S12. Dissolve chitosan in acetic acid solution to obtain a 5wt% chitosan solution;

[0032] S13. Add the magnetic montmorillonite prepared in step S11 to the chitosan solution. The concentration of magnetic montmorillonite in the chitosan solution is 3wt%. Prepare nanofiber bundles by electrospinning, cut the nanofiber bundles to 0.5-2mm, and then perform ultrasonic dispersion in a 0.01mol / L hydrochloric acid solution. The ultrasonic power is 300W and the dispersion time is 300min to obtain montmorillonite-loaded chitosan nanofibers;

[0033] Among them, the preparation method of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres includes the following steps:

[0034] S21. Dissolve cellulose in a sodium hydroxide / urea / water system to obtain a cellulose solution;

[0035] S22. Add graphene oxide to water, ultrasonically disperse evenly, and then add it to the cellulose solution to obtain a GO / CNC composite solution;

[0036] S23. Add the GO / CNC composite solution to liquid paraffin containing Span80 under stirring conditions. The stirring speed is 400r / min and the stirring time is 6h. Then add dilute hydrochloric acid to make the solution layer. Separate, collect the lower layer of GO / CNC microspheres;

[0037] S24. Add the GO / CNC microspheres to a 0.2mol / L silver nitrate solution, stir well, and filter to obtain Ag+-loaded GO / CNC microspheres;

[0038] S25. Add the Ag+-loaded GO / CNC microspheres to a 0.1mol / L sodium citrate solution and heat for reaction to obtain Ag-loaded GO / CNC microspheres;

[0039] S26. Add the Ag-loaded GO / CNC microspheres and citric acid with a mass ratio of 2:1 to water, add sodium hydroxide to adjust the pH of the solution to 3, let it stand at room temperature for 10 h and then dry at low temperature. After drying, carry out an esterification reaction at a temperature of 160 °C for 2 h to obtain the esterified Ag-loaded GO / CNC microspheres;

[0040] S27. Add the esterified Ag-loaded GO / CNC microspheres to an aqueous solution of polyethylene glycol with a molecular weight of 5000. The mass ratio of the esterified Ag-loaded GO / CNC microspheres to polyethylene glycol is 1:20, and stannous octoate is added. Heat and react at 80 °C for 10 h to obtain the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

[0041] Example 2

[0042] A composite algae-removing material, which is composed of montmorillonite-loaded chitosan nanofibers and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres;

[0043] Among them, the preparation method of the montmorillonite-loaded chitosan nanofibers includes the following steps:

[0044] S11. Add ferric chloride hexahydrate, sodium acetate and polyethylene glycol to ethylene glycol, stir and mix evenly, then add cation-modified nano-montmorillonite and heat to react. The mass-to-volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite and ethylene glycol is 120 g: 350 g: 85 g: 35 g: 3000 mL. The temperature of the heating reaction is 230 °C and the time is 6 h to obtain magnetic montmorillonite; S12. Dissolve chitosan in acetic acid solution to obtain an 8 wt% chitosan solution;

[0045] S13. Add the magnetic montmorillonite prepared in step S11 to the chitosan solution. The concentration of the magnetic montmorillonite in the chitosan solution is 6 wt%. Prepare nanofiber bundles by electrospinning. Cut the nanofiber bundles to 0.5 - 2 mm and then carry out ultrasonic dispersion in a 0.01 mol / L hydrochloric acid solution with a ultrasonic power of 500 W and a dispersion time of 100 min to obtain the montmorillonite-loaded chitosan nanofibers;

[0046] Among them, the preparation method of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres includes the following steps:

[0047] S21. Dissolve cellulose in the sodium hydroxide / urea / water system to obtain a cellulose solution;

[0048] S22. Add graphene oxide to water, ultrasonically disperse it evenly, and then add it to the cellulose solution to obtain a GO / CNC composite solution;

[0049] S23. The GO / CNC composite solution was added to the liquid paraffin containing Span80 under stirring conditions at a stirring speed of 800 r / min for 2 h, and then dilute hydrochloric acid was added dropwise to separate the solution and collect the lower layer of GO / CNC microspheres;

[0050] S24. Add GO / CNC microspheres to 0.6 mol / L silver nitrate solution, stir thoroughly, and filter to obtain Ag+-loaded GO / CNC microspheres;

[0051] S25. Adding the Ag+-loaded GO / CNC microspheres to a 0.5 mol / L trisodium citrate solution, heating the solution to obtain Ag-loaded GO / CNC microspheres;

[0052] S26. Add Ag-loaded GO / CNC microspheres and citric acid in a mass ratio of 3:1 to water, add sodium hydroxide to adjust the pH of the solution to 3, let stand at room temperature for 15 hours, and then dry at low temperature. After drying, perform an esterification reaction at a temperature of 120° C. for 3 hours to obtain esterified Ag-loaded GO / CNC microspheres;

[0053] S27. The esterified Ag-loaded GO / CNC microspheres were added to a polyethylene glycol aqueous solution with a molecular weight of 8000, the mass ratio of the esterified Ag-loaded GO / CNC microspheres to the polyethylene glycol was 1:10, and stannous octoate was added. The reaction was heated at 100°C for 6 hours to obtain polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

[0054] Example 3

[0055] A composite algae removal material, the algae removal material is composed of montmorillonite-loaded chitosan nanowires and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres;

[0056] The method for preparing montmorillonite-loaded chitosan nanowires comprises the following steps:

[0057] S11. Add ferric chloride hexahydrate, sodium acetate and polyethylene glycol to ethylene glycol and stir to mix evenly, then add cationic modified nano-montmorillonite and heat to react. The mass volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite and ethylene glycol is 90g:280g:70g:26g:3000mL. The heating reaction temperature is 190°C for 10h to obtain magnetic montmorillonite. S12. Dissolve chitosan in acetic acid solution to obtain a chitosan solution with a concentration of 6wt%;

[0058] S13. Add the magnetic montmorillonite prepared in step S11 to the chitosan solution. The concentration of the magnetic montmorillonite in the chitosan solution is 4 wt%. Prepare nanofiber bundles by electrospinning. After cutting the nanofiber bundles to 0.5 - 2 mm, perform ultrasonic dispersion in a hydrochloric acid solution with a concentration of 0.06 mol / L. The ultrasonic power is 350 W, and the dispersion time is 150 min to obtain montmorillonite-loaded chitosan nanowires;

[0059] Among them, the preparation method of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres includes the following steps:

[0060] S21. Dissolve cellulose in the sodium hydroxide / urea / water system to obtain a cellulose solution;

[0061] S22. Add graphene oxide to water, ultrasonically disperse it evenly, and then add it to the cellulose solution to obtain a GO / CNC composite solution;

[0062] S23. Add the GO / CNC composite solution to liquid paraffin containing Span80 under stirring conditions. The stirring speed is 500 r / min, and the stirring time is 5 h. Then, add dilute hydrochloric acid to make the solution layer. Collect the lower-layer GO / CNC microspheres;

[0063] S24. Add the GO / CNC microspheres to a 0.3 mol / L silver nitrate solution, stir well, and then filter to obtain Ag+-loaded GO / CNC microspheres;

[0064] S25. Add the Ag+-loaded GO / CNC microspheres to a 0.2 mol / L trisodium citrate solution, heat and react to obtain Ag-loaded GO / CNC microspheres;

[0065] S26. Add Ag-loaded GO / CNC microspheres and citric acid with a mass ratio of 2.2:1 to water, add sodium hydroxide to adjust the pH of the solution to 3, let it stand at room temperature for 15 h, and then perform low-temperature drying. After drying, perform an esterification reaction. The temperature of the esterification reaction is 130 °C, and the time is 3 h to obtain esterified Ag-loaded GO / CNC microspheres;

[0066] S27. Add the esterified Ag-loaded GO / CNC microspheres to an aqueous solution of polyethylene glycol with a molecular weight of 6000. The mass ratio of the esterified Ag-loaded GO / CNC microspheres to polyethylene glycol is 1:12, and add stannous octoate. Heat and react at 80 °C for 9 h to obtain polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

[0067] Example 4

[0068] A composite algae-removing material, and the algae-removing material is composed of montmorillonite-loaded chitosan nanowires and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres;

[0069] The method for preparing montmorillonite-loaded chitosan nanowires comprises the following steps:

[0070] S11. Add ferric chloride hexahydrate, sodium acetate and polyethylene glycol to ethylene glycol and stir to mix evenly, then add cationic modified nano-montmorillonite and heat to react. The mass volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite and ethylene glycol is 110g:320g:80g:32g:3000mL. The heating reaction temperature is 220°C and the time is 8h to obtain magnetic montmorillonite. S12. Dissolve chitosan in acetic acid solution to obtain a chitosan solution with a concentration of 7wt%;

[0071] S13. The magnetic montmorillonite prepared in step S11 is added to the chitosan solution, wherein the concentration of the magnetic montmorillonite in the chitosan solution is 5wt%, and a nanofiber bundle is prepared by electrospinning. The nanofiber bundle is chopped to 0.5-2mm and then ultrasonically dispersed in a 0.02mol / L hydrochloric acid solution. The ultrasonic power is 450W and the dispersion time is 250min to obtain montmorillonite-loaded chitosan nanowires;

[0072] The method for preparing polyethylene glycol-grafted Ag-loaded GO / CNC microspheres comprises the following steps:

[0073] S21. dissolving cellulose in a sodium hydroxide / urea / water system to obtain a cellulose solution;

[0074] S22. adding graphene oxide to water, uniformly dispersing by ultrasonication, and then adding to the cellulose solution to obtain a GO / CNC composite solution;

[0075] S23. The GO / CNC composite solution was added to the liquid paraffin containing Span80 under stirring conditions at a stirring speed of 700 r / min for 3 h, and then dilute hydrochloric acid was added dropwise to separate the solution and collect the lower layer of GO / CNC microspheres;

[0076] S24. Add GO / CNC microspheres to 0.5 mol / L silver nitrate solution, stir thoroughly, and filter to obtain GO / CNC microspheres loaded with Ag+;

[0077] S25. Adding the Ag+-loaded GO / CNC microspheres to a 0.4 mol / L trisodium citrate solution, heating the solution to obtain Ag-loaded GO / CNC microspheres;

[0078] S26. Add the Ag-loaded GO / CNC microspheres with a mass ratio of 2.6:1 and citric acid into water, add sodium hydroxide to adjust the pH of the solution to 3, let it stand at room temperature for 10 h and then dry it at low temperature. After drying, carry out an esterification reaction at a temperature of 150 °C for 2 h to obtain the esterified Ag-loaded GO / CNC microspheres;

[0079] S27. Add the esterified Ag-loaded GO / CNC microspheres into an aqueous solution of polyethylene glycol with a molecular weight of 7000. The mass ratio of the esterified Ag-loaded GO / CNC microspheres to polyethylene glycol is 1:18, and add stannous octoate. Heat and react at 100 °C for 7 h to obtain the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

[0080] Example 5

[0081] A composite algae removal material, which is composed of montmorillonite-loaded chitosan nanofibers and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres;

[0082] Among them, the preparation method of the montmorillonite-loaded chitosan nanofibers includes the following steps:

[0083] S11. Add ferric chloride hexahydrate, sodium acetate and polyethylene glycol into ethylene glycol, stir and mix evenly, then add cation-modified nano-montmorillonite and heat and react. The mass-volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite and ethylene glycol is 100 g: 300 g: 75 g: 28 g: 3000 mL. The temperature of the heat and reaction is 200 °C and the time is 9 h to obtain magnetic montmorillonite; S12. Dissolve chitosan in acetic acid solution to obtain a 6.5 wt% chitosan solution;

[0084] S13. Add the magnetic montmorillonite prepared in step S11 into the chitosan solution. The concentration of the magnetic montmorillonite in the chitosan solution is 4.5 wt%. Prepare nanofiber bundles by electrospinning. Cut the nanofiber bundles into 0.5 - 2 mm and then carry out ultrasonic dispersion in a 0.04 mol / L hydrochloric acid solution. The ultrasonic power is 400 W and the dispersion time is 200 min to obtain the montmorillonite-loaded chitosan nanofibers;

[0085] Among them, the preparation method of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres includes the following steps:

[0086] S21. Dissolve cellulose in a sodium hydroxide / urea / water system to obtain a cellulose solution;

[0087] S22. Add graphene oxide into water, ultrasonically disperse it evenly, and then add it into the cellulose solution to obtain a GO / CNC composite solution;

[0088] S23. The GO / CNC composite solution was added to the liquid paraffin containing Span80 under stirring conditions at a stirring speed of 600 r / min for 4 h, and then dilute hydrochloric acid was added dropwise to separate the solution and collect the lower layer of GO / CNC microspheres;

[0089] S24. Add GO / CNC microspheres to 0.4 mol / L silver nitrate solution, stir thoroughly, and filter to obtain Ag+-loaded GO / CNC microspheres;

[0090] S25. Adding the Ag+-loaded GO / CNC microspheres to a 0.3 mol / L trisodium citrate solution, heating the solution to obtain Ag-loaded GO / CNC microspheres;

[0091] S26. Add Ag-loaded GO / CNC microspheres and citric acid in a mass ratio of 2.4:1 to water, add sodium hydroxide to adjust the pH of the solution to 3, let stand at room temperature for 12 hours, and then dry at low temperature. After drying, perform an esterification reaction at a temperature of 140°C for 2.5 hours to obtain esterified Ag-loaded GO / CNC microspheres;

[0092] S27. The esterified Ag-loaded GO / CNC microspheres were added to a polyethylene glycol aqueous solution with a molecular weight of 8000, the mass ratio of the esterified Ag-loaded GO / CNC microspheres to polyethylene glycol was 1:15, and stannous octoate was added. The reaction was heated at 85°C for 8 hours to obtain polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

[0093] Comparative Example 1

[0094] The difference between Comparative Example 1 and Example 5 is that Comparative Example 1 contains only montmorillonite-loaded chitosan nanowires;

[0095] Comparative Example 2

[0096] The difference between Comparative Example 2 and Example 5 is that Comparative Example 2 contains only GO / CNC microspheres grafted with polyethylene glycol and loaded with Ag;

[0097] A composite algae removal material, the algae removal material is composed of montmorillonite-loaded chitosan nanowires and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres;

[0098] The method for preparing montmorillonite-loaded chitosan nanowires comprises the following steps:

[0099] S11. Add ferric chloride hexahydrate, sodium acetate, and polyethylene glycol to ethylene glycol, stir and mix evenly, then add cation-modified nano-montmorillonite and heat for reaction. The mass-volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite, and ethylene glycol is 100 g: 300 g: 75 g: 28 g: 3000 mL. The temperature of the heating reaction is 200 °C and the time is 9 h to obtain magnetic montmorillonite; S12. Dissolve chitosan in acetic acid solution to obtain a 6.5 wt% chitosan solution;

[0100] S13. Add the magnetic montmorillonite prepared in step S11 to the chitosan solution. The concentration of magnetic montmorillonite in the chitosan solution is 4.5 wt%. Prepare nanofiber bundles by electrospinning. After cutting the nanofiber bundles to 0.5 - 2 mm, perform ultrasonic dispersion in a 0.04 mol / L hydrochloric acid solution. The ultrasonic power is 400 W and the dispersion time is 200 min to obtain montmorillonite-loaded chitosan nanowires;

[0101] Among them, the preparation method of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres includes the following steps:

[0102] S21. Dissolve cellulose in a sodium hydroxide / urea / water system to obtain a cellulose solution;

[0103] S22. Add graphene oxide to water, ultrasonically disperse evenly, and then add it to the cellulose solution to obtain a GO / CNC composite solution;

[0104] S23. Add the GO / CNC composite solution to liquid paraffin containing Span80 under stirring conditions. The stirring speed is 600 r / min and the stirring time is 4 h. Then add dilute hydrochloric acid to make the solution layer. Collect the lower-layer GO / CNC microspheres;

[0105] S24. Add the GO / CNC microspheres to a 0.4 mol / L silver nitrate solution, stir well, and then filter to obtain Ag+-loaded GO / CNC microspheres;

[0106] S25. Add the Ag+-loaded GO / CNC microspheres to a 0.3 mol / L trisodium citrate solution and heat for reaction to obtain Ag-loaded GO / CNC microspheres;

[0107] S26. Add Ag-loaded GO / CNC microspheres and citric acid with a mass ratio of 2.4:1 to water, add sodium hydroxide to adjust the pH of the solution to 3, stand at room temperature for 12 h, then dry at low temperature. After drying, perform an esterification reaction. The temperature of the esterification reaction is 140 °C and the time is 2.5 h to obtain esterified Ag-loaded GO / CNC microspheres;

[0108] S27. Add the esterified Ag-loaded GO / CNC microspheres to polyethylene glycol with a molecular weight of 400. The mass ratio of the esterified Ag-loaded GO / CNC microspheres to polyethylene glycol is 1:15, and stannous octoate is added. Heat and react at 85 °C for 8 h to obtain polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

[0109] Comparative Example 4

[0110] A composite algae removal material, which is composed of magnetic montmorillonite and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres; wherein, the preparation method of the magnetic montmorillonite includes the following steps: Add ferric chloride hexahydrate, sodium acetate and polyethylene glycol to ethylene glycol, stir and mix evenly, then add cation-modified nano-montmorillonite and heat and react. The mass-volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite and ethylene glycol is 100 g: 300 g: 75 g: 28 g: 3000 mL. The temperature of the heat reaction is 200 °C and the time is 9 h to obtain magnetic montmorillonite;

[0111] Among them, the preparation method of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres includes the following steps:

[0112] S21. Dissolve cellulose in a sodium hydroxide / urea / water system to obtain a cellulose solution;

[0113] S22. Add graphene oxide to water, ultrasonically disperse it evenly, and then add it to the cellulose solution to obtain a GO / CNC composite solution;

[0114] S23. Add the GO / CNC composite solution to liquid paraffin containing Span80 under stirring conditions. The stirring speed is 600 r / min and the stirring time is 4 h. Then add dilute hydrochloric acid to make the solution layer. Separate, and collect the lower layer of GO / CNC microspheres;

[0115] S24. Add the GO / CNC microspheres to a 0.4 mol / L silver nitrate solution, stir well, and filter to obtain Ag+-loaded GO / CNC microspheres;

[0116] S25. Add the Ag+-loaded GO / CNC microspheres to a 0.3 mol / L trisodium citrate solution, heat and react to obtain Ag-loaded GO / CNC microspheres;

[0117] S26. Add Ag-loaded GO / CNC microspheres and citric acid with a mass ratio of 2.4:1 to water, add sodium hydroxide to adjust the pH of the solution to 3, let it stand at room temperature for 10 h, then dry at low temperature. After drying, carry out an esterification reaction. The temperature of the esterification reaction is 140 °C and the time is 2.5 h to obtain esterified Ag-loaded GO / CNC microspheres;

[0118] S27. The esterified Ag-loaded GO / CNC microspheres were added to an aqueous solution of polyethylene glycol with a molecular weight of 8000. The mass ratio of the esterified Ag-loaded GO / CNC microspheres to polyethylene glycol was 1:15, and stannous octoate was added. The reaction was heated at 85 °C for 8 h to obtain polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

[0119] Comparative Example 5

[0120] A composite algae-removing material, which is composed of montmorillonite-loaded chitosan nanofibers and polyethylene glycol-grafted GO / CNC microspheres;

[0121] Among them, the preparation method of the montmorillonite-loaded chitosan nanofibers includes the following steps:

[0122] S11. Ferric chloride hexahydrate, sodium acetate and polyethylene glycol were added to ethylene glycol and stirred and mixed evenly. Then, cation-modified nano-montmorillonite was added and heated for reaction. The mass-volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite and ethylene glycol was 100 g: 300 g: 75 g: 28 g: 3000 mL. The temperature of the heating reaction was 200 °C and the time was 9 h to obtain magnetic montmorillonite; S12. Chitosan was dissolved in acetic acid solution to obtain a 6.5 wt% chitosan solution;

[0123] S13. The magnetic montmorillonite prepared in step S11 was added to the chitosan solution. The concentration of magnetic montmorillonite in the chitosan solution was 4.5 wt%. Nanofiber bundles were prepared by electrospinning. After the nanofiber bundles were cut into 0.5 - 2 mm, they were ultrasonically dispersed in a 0.04 mol / L hydrochloric acid solution with an ultrasonic power of 400 W and a dispersion time of 200 min to obtain montmorillonite-loaded chitosan nanofibers;

[0124] Among them, the preparation method of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres includes the following steps:

[0125] S21. Cellulose was dissolved in a sodium hydroxide / urea / water system to obtain a cellulose solution;

[0126] S22. Graphene oxide was added to water, ultrasonically dispersed evenly, and then added to the cellulose solution to obtain a GO / CNC composite solution;

[0127] S23. The GO / CNC composite solution was added to liquid paraffin containing Span80 under stirring conditions at a stirring speed of 600 r / min for 4 h. Then, dilute hydrochloric acid was added to make the solution layer. The lower-layer GO / CNC microspheres were collected;

[0128] S24. Add GO / CNC microspheres and citric acid with a mass ratio of 2.4:1 to water, add sodium hydroxide to adjust the pH of the solution to 3, let it stand at room temperature for 15 h, then dry it at low temperature. After drying, carry out an esterification reaction at a temperature of 140 °C for 2.5 h to obtain esterified GO / CNC microspheres;

[0129] S27. Add the esterified GO / CNC microspheres to an aqueous solution of polyethylene glycol with a molecular weight of 8000. The mass ratio of the esterified GO / CNC microspheres to polyethylene glycol is 1:15, and add stannous octoate. Heat and react at 85 °C for 8 h to obtain polyethylene glycol-grafted GO / CNC microspheres.

[0130] Prepare solutions of the two components in the composite algae-removing materials prepared in Examples 1-5 and Comparative Examples 3-4 respectively, and conduct an experiment on the sedimentation effect on Aureococcus anophagefferens. In Examples 1-5 and Comparative Example 3, the dosage of montmorillonite-loaded chitosan nanofibers per cubic meter of water body is 15 g, and the dosage of polyethylene glycol-grafted Ag-loaded GO / CNC microspheres per cubic meter of water body is 8 g. In Comparative Example 1, the dosage of montmorillonite-loaded chitosan nanofibers per cubic meter of water body is 15 g. In Comparative Example 2, the dosage of polyethylene glycol-grafted Ag-loaded GO / CNC microspheres per cubic meter of water body is 8 g. In Comparative Example 4, the dosage of magnetic montmorillonite per cubic meter of water body is 15 g, and the dosage of polyethylene glycol-grafted Ag-loaded GO / CNC microspheres per cubic meter of water body is 8 g. In Comparative Example 5, the dosage of montmorillonite-loaded chitosan nanofibers per cubic meter of water body is 15 g, and the dosage of polyethylene glycol-grafted GO / CNC microspheres per cubic meter of water body is 8 g; due to the difference in the dosing method in Comparative Example 6, the preparation method in Comparative Example 6 is the same as that in Example 5, but when used in Comparative Example 6, magnetic montmorillonite and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres are added to water at the same time to prepare a spraying solution; in Comparative Example 7, the dosage of montmorillonite-loaded chitosan nanofibers per cubic meter of water body is 5 g, and the dosage of polyethylene glycol-grafted Ag-loaded GO / CNC microspheres per cubic meter of water body is 8 g.

[0131] The algal cell density of Aureococcus anophagefferens in the algal solution used in the test is about 9.0×109 cells / L - 10.0×109 cells / L respectively.

[0132] Table 1 shows the algae removal rate

[0133] 24h removal rate / % 7d removal rate 30d removal rate Example 1 65.6 93.2 98.2 Example 2 62.9 92.1 97.5 Example 3 66.4 95.5 97.2 Example 4 69.1 94.8 98.5 Example 5 68.7 96.2 98.0 Comparative Example 1 68.2 95.6 89.6 Comparative Example 2 25.9 35.6 15.9 Comparative Example 3 56.9 75.8 85.3 Comparative Example 4 62.8 89.5 88.6 Comparative Example 5 66.9 93.6 88.5 Comparative Example 6 56.8 85.9 88.1 Comparative Example 7 57.9 85.1 89.4

[0134] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom still fall within the protection scope of the present invention.

Claims

1. An application of a composite algae removal material, characterized in that: The algae removal material is composed of montmorillonite-loaded chitosan nanowires and polyethylene glycol-grafted Ag-loaded GO / CNC microspheres; the montmorillonite-loaded chitosan nanowires and the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres are respectively mixed with water to prepare a montmorillonite-loaded chitosan nanowire solution and a polyethylene glycol-grafted Ag-loaded GO / CNC microsphere solution, and the two solutions are sprayed on the surface of algae in sequence to remove the algae; The method for preparing montmorillonite-loaded chitosan nanowires comprises the following steps: S11. After adding ferric chloride hexahydrate, sodium acetate and polyethylene glycol to ethylene glycol and stirring to mix evenly, the cationic modified nano-montmorillonite is added and heated to react. The mass volume ratio of ferric chloride hexahydrate, sodium acetate, polyethylene glycol, montmorillonite and ethylene glycol is 80-120g: 250-350g: 65-85g: 25-35g: 3000mL to obtain magnetic montmorillonite; S12. The chitosan was dissolved in an acetic acid solution to obtain a concentration of 5-8wt% chitosan solution; S13. The magnetic montmorillonite prepared in step S11 is added to the chitosan solution to prepare nanofiber bundles by electrospinning, and the nanofiber bundles are chopped to 0.5-2 mm and then ultrasonically dispersed in a hydrochloric acid solution to obtain montmorillonite-loaded chitosan nanowires; The preparation method of the polyethylene glycol-grafted Ag-loaded GO / CNC microspheres comprises the following steps: S21 dissolving cellulose in a sodium hydroxide / urea / water system to obtain a cellulose solution; S22. Graphene oxide is added to water, dispersed uniformly by ultrasonication, and then added to the cellulose solution to obtain a GO / CNC composite solution; S23. The GO / CNC composite solution was added to liquid paraffin containing Span80 under stirring conditions, and then dilute hydrochloric acid was added dropwise to separate the solution and collect the lower layer of GO / CNC microspheres; S24. The GO / CNC microspheres were added to a 0.2-0.6 mol / L silver nitrate solution, stirred thoroughly, and filtered to obtain the Ag+-loaded GO / CNC microspheres; S25. The Ag+-loaded GO / CNC microspheres were added to a 0.1-0.5 mol / L trisodium citrate solution and heated to react to obtain Ag-loaded GO / CNC microspheres; S26. Adding Ag-loaded GO / CNC microspheres and citric acid in a mass ratio of 2-3:1 to water, adding sodium hydroxide to adjust the pH of the solution to 3, standing at room temperature for 10-15 hours and then drying at low temperature, and then performing an esterification reaction to obtain esterified Ag-loaded GO / CNC microspheres; S27. Add the esterified Ag-loaded GO / CNC microspheres to a polyethylene glycol aqueous solution, wherein the mass ratio of the esterified Ag-loaded GO / CNC microspheres to the polyethylene glycol is 1:10-20, and the molecular weight of the polyethylene glycol is 5000-8000. Add stannous octoate, and heat to react to obtain polyethylene glycol-grafted Ag-loaded GO / CNC microspheres.

2. The use of the composite algae removal material according to claim 1, characterized in that: The heating reaction temperature in step S11 is 180-230° C. and the time is 6-12 hours.

3. The use of the composite algae removal material according to claim 1, characterized in that: In the step S13, the concentration of magnetic montmorillonite in the chitosan solution is 3-6wt%, the concentration of the hydrochloric acid solution is 0.01-0.1mol / L, the ultrasonic power is 300-500W, and the dispersion time is 100-300min.

4. The use of the composite algae removal material according to claim 1, characterized in that: In step S23, the stirring speed is 400-800 r / min, and the stirring time is 2-6 h.

5. The use of the composite algae removal material according to claim 1, characterized in that: The temperature of the esterification reaction in step S26 is 120-160° C. and the time is 2-3 hours.

6. The use of the composite algae removal material according to claim 1, characterized in that: The heating reaction temperature in step S27 is 80-100° C. and the time is 6-10 hours.

7. The use of the composite algae removal material according to claim 1, characterized in that: The dosage of the algae removal material is as follows: the dosage of montmorillonite-loaded chitosan nanowires is 10-15 g per cubic meter of water, and the dosage of polyethylene glycol-grafted Ag-loaded GO / CNC microspheres is 5-10 g per cubic meter of water.