A method for preparing a carbon nanotube blended conductive film and a method for controlling algae pollution by coupling the film with electro-activated peracetic acid

Abstract

The present invention belongs to the technical field of pollution control for membrane water treatment, and specifically relates to a method for preparing a carbon nanotube blended conductive membrane and a method for controlling algae pollution by coupling the membrane with electrically activated peracetic acid. Carbon nanotubes modified with oxygen functional groups, polyvinyl pyrrolidone, and polyether sulfone are dispersed in an organic solvent to prepare a casting solution, a base membrane is prepared by a flat-plate scraping process, and then the base membrane is modified with conductive polyaniline-sodium polystyrene sulfonate by an in-situ cross-linking method to prepare a carbon nanotube blended conductive membrane. In a coupled membrane filtration system, peracetic acid is used as an oxidant, and the peracetic acid is activated in situ by applying a voltage to the membrane to generate active species with oxidizing ability. The algae pollutant solution is used as the target water body, and the filtration system is used to achieve efficient mitigation of membrane pollution caused by algae pollutants.

Description

Technical Field

[0001] The present invention belongs to the technical field of pollution control of membrane water treatment, and particularly relates to a method for preparing a carbon nanotube blended conductive membrane and a method for controlling algae source pollution by coupling the membrane with electrically activated peracetic acid. Background Art

[0002] Algal pollution is a serious problem facing aquatic environments worldwide. Primarily caused by eutrophication, it leads to algal blooms, hypoxia, and the proliferation of harmful algae. This not only disrupts aquatic ecosystems but also significantly impacts drinking water safety, fisheries, and tourism. Traditional methods for controlling algal pollution include chemical injection, physical precipitation, and biological control. However, these methods can suffer from secondary pollution, unstable results, and high costs. In recent years, membrane separation technology has become a key tool in water treatment due to its high efficiency, energy-saving, and environmentally friendly advantages. Ultrafiltration membranes, in particular, excel in removing suspended solids, colloids, and microorganisms. However, conventional ultrafiltration membranes are susceptible to fouling when treating algal-contaminated water, resulting in reduced flux and increased operating costs. To address this issue, researchers are attempting to improve membrane anti-fouling properties and separation efficiency through material modification and process optimization. Carbon nanotubes, due to their excellent electrical conductivity, mechanical strength, and chemical stability, are widely used in the preparation of new high-performance membrane materials to enhance membrane performance. Furthermore, peracetic acid, as an efficient and environmentally friendly oxidant, can generate active species with strong oxidizing properties and is widely used to degrade organic pollutants. Therefore, combining carbon nanotubes with peracetic acid and using electroactivation technology is expected to achieve efficient control of algae pollution. Summary of the Invention

[0003] The present invention aims to provide a method for preparing a carbon nanotube-blended conductive membrane and its coupling with electro-activated peracetic acid for effective control of algal contamination. This method enhances the membrane's conductivity and electro-oxidative activity by introducing oxygen-functionalized carbon nanotubes into the separation membrane. Combined with electro-activated peracetic acid, this method generates highly efficient oxidizing species, effectively removing algal contaminants. Using the conductive membrane as the working electrode, voltage is applied during the separation process to achieve efficient contaminant removal and control membrane contamination.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In one aspect, the present invention provides a method for preparing a carbon nanotube blended conductive film, comprising the following steps:

[0006] (1) Oxygen functional group modification of carbon nanotubes

[0007] The carbon nanotubes are evenly distributed in a crystallization dish and placed in an oxygen plasma generator for treatment to obtain carbon nanotubes modified with oxygen functional groups;

[0008] (2) Preparation of casting solution

[0009] Adding oxygen functional group-modified carbon nanotubes, polyethersulfone and polyvinylpyrrolidone to a solvent, stirring uniformly at room temperature for 18 to 36 hours to obtain a dispersion, then adding polyethylene glycol at a constant temperature of 50 to 80°C, stirring until completely dissolved, and then standing to degas to obtain a casting solution;

[0010] (3) Preparation of basement membrane

[0011] The casting solution was applied to the glass plate, and the glass plate coated with the casting solution was immersed in a coagulation bath for 30 minutes to complete the curing of the base film;

[0012] (4) In situ cross-linking of basement membrane

[0013] The solidified base film is transferred from the coagulation bath to deionized water for soaking and washing, and the base film is placed in a mixture of aniline and sodium poly(p-styrene sulfonate) and soaked at 4°C for 20 to 30 minutes. The base film is then taken out and immersed in an ammonium persulfate solution to react for 5 to 10 minutes. The base film is then placed at 4°C to react for 3 to 6 hours. The base film is then taken out and placed in an acidic solution of glutaraldehyde for cross-linking. The base film is then washed with pure water and soaked in pure water to obtain a carbon nanotube blended conductive film.

[0014] In the above technical solution, further, in step (1), the oxygen content of the carbon nanotubes modified with oxygen functional groups is 0.1 to 0.5 wt%;

[0015] The carbon nanotubes are multi-walled carbon nanotubes or multi-walled array carbon nanotubes, and the diameter of the carbon nanotubes is 10 to 25 nm;

[0016] The plasma radio frequency power is 50 to 100 W, the radio frequency frequency is 13.56 MHz, the gas pressure in the chamber is 50 to 100 Pa, and the processing time is 10 to 60 s.

[0017] In the above technical solution, further, in step (2), the solvent is one or a mixture of two of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide;

[0018] The molecular weight of the polyethylene glycol is 50,000 to 300,000.

[0019] In the above technical solution, further, in step (2), the mass fraction of the solute in the casting solution is 30-60%.

[0020] In the above technical solution, further, in step (2), in the casting solution, the mass ratio of oxygen functional group-modified carbon nanotubes, polyethersulfone, polyvinyl pyrrolidone, and polyethylene glycol is (2-3):3:1:1.

[0021] In the above technical solution, further, in step (3), the scraping gap of the flat scraper is 300 to 500 μm, and the scraping is carried out at a constant speed of 5 to 10 cm / s; the coagulation bath is an N,N-dimethylacetamide aqueous solution with a mass fraction of 10% to 20%, and the temperature of the coagulation bath is 20 to 25°C.

[0022] In the above technical solution, further, in step (4), the basement membrane is soaked and washed at a constant temperature of 40 to 60° C. for 0.5 to 1 hour;

[0023] The cross-linking time of the glutaraldehyde is 30 to 60 minutes.

[0024] In the above technical solution, further, in step (4), in the mixed solution of aniline and sodium poly(p-styrene sulfonate), the mass ratio of aniline to sodium poly(p-styrene sulfonate) is 1:1, and the aniline concentration is 0.5-2.0 wt%.

[0025] Another aspect of the present invention provides a carbon nanotube blended conductive film obtained by the above preparation method.

[0026] The present invention also provides a method for controlling algae pollution by coupling a carbon nanotube blended conductive membrane with electro-activated peracetic acid. The carbon nanotube blended conductive membrane is used as a membrane electrode. During the treatment of algae-contaminated water, peracetic acid is added to the influent at a concentration of 0.5 to 5 mg / L. A voltage of 0.5 to 3 V is applied to the membrane. The filtration method is constant pressure cross-flow filtration, the filtration pressure is 0.5 to 2.0 bar, and the cross-flow velocity is 0.05 to 0.1 m / s.

[0027] In the above technical solution, further, the method specifically includes the following steps:

[0028] a. Encapsulate the carbon nanotube blend conductive film in a flat membrane module, with the membrane serving as the working electrode. A counter electrode metal mesh of the same area is placed opposite the membrane inside the module, with a distance of 8 mm between the metal mesh and the flat membrane. Lead wires extend from the metal mesh, connecting the metal electrode clip and the wires to the conductive film. The two-stage wires are connected to an external DC regulated power supply.

[0029] b. Add 0.5-10 mg / L of peracetic acid to the algae-contaminated water, and simultaneously apply voltage to the conductive membrane through a DC regulated power supply to perform cross-flow filtration. Adjust the filtration pressure of the membrane module to a constant level of 0.5-2 bar.

[0030] c. When the operating flux drops by 50%, stop filtration, close the cross-flow valve, open the inlet valve and outlet valve, apply pressure water flow from the outlet valve side to perform backwashing to remove membrane fouling.

[0031] In the above technical solution, further, in step a, the metal mesh is a titanium mesh, copper mesh or stainless steel mesh; the lead wire is a titanium wire, copper wire or stainless steel wire; the electrode clamp is a titanium electrode clamp, copper electrode clamp or stainless steel electrode clamp.

[0032] In the above technical solution, further, in step b, the applied voltage is 0.5 to 3.0 V, preferably 2.0 to 2.5 V, the membrane is the cathode, and the metal mesh is the anode.

[0033] In the above technical solution, further, in step c, during backwashing, the backwash pressure is 0.5 to 1.0 bar, and the backwash time is 5 to 15 minutes.

[0034] The present invention prepares an electroactive separation membrane by modifying the oxygen functional groups of carbon nanotubes and adopting a blending and cross-linking method, thereby constructing a membrane separation layer with excellent peracetic acid electroactivation properties. Under the condition of an applied voltage, the peracetic acid can be activated to produce a large number of active free radical species, which can efficiently oxidize organic matter in algae-contaminated water and slow down the accumulation of pollutants on the membrane surface and in the membrane pores.

[0035] This paper proposes a method based on a carbon nanotube-blended conductive membrane coupled with electroactivated peracetic acid for efficient control of algal contamination. Compared with traditional water treatment technologies, this method offers the following significant advantages and benefits:

[0036] 1. Efficient removal of algae-derived pollutants: By electrically activating peracetic acid to generate highly active oxidizing species, the system can completely degrade harmful substances such as microcystins in water, achieving a 100% removal rate. This effectively addresses the difficulty in removing algae toxins in traditional drinking water treatment processes, ensuring the safety of drinking water.

[0037] 2. Significantly Reduces the Accumulation Rate of Membrane Fouling: The carbon nanotube blended conductive membrane exhibits excellent electrical conductivity and anti-fouling properties. During the filtration process, the accumulation rate of membrane fouling is reduced by over 90%, effectively mitigating both reversible and irreversible membrane fouling. This extends the membrane's service life and reduces maintenance and replacement costs.

[0038] 3. Enhanced mechanical and chemical stability of the membrane: The addition of carbon nanotubes improves the mechanical strength and chemical corrosion resistance of the membrane, making it suitable for a variety of complex water treatment environments. This overcomes the defect of traditional polyethersulfone membranes that are insufficiently stable in strong oxidizing environments.

[0039] 4. Low energy consumption for water production: The electrical activation of peracetic acid can be achieved at a relatively low voltage (0.5-3V), and the filtration resistance is reduced. Compared with other advanced oxidation technologies, such as ozone oxidation or ultraviolet photocatalysis, the energy consumption is low.

[0040] 5. Environmentally friendly, no secondary pollution: Peracetic acid decomposes into water, oxygen and acetic acid after the reaction, which is environmentally friendly. The electroactivation process does not produce harmful by-products, avoiding the risk of secondary pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is an electronic photograph of the casting solution prepared in Example 1;

[0042] Figure 2 This is an electronic photograph of the carbon nanotube blended conductive film prepared in Example 1;

[0043] Figure 3 This is a process flow chart of the method for preparing the carbon nanotube blended conductive film of the present invention;

[0044] Figure 4 This is a diagram showing the anti-membrane fouling effect of the carbon nanotube blended conductive membrane of Example 1 coupled with electrically activated peracetic acid in filtering an algae extracellular polymer solution;

[0045] Figure 5 This is a diagram showing the removal effect of microcystin when filtering an algal extracellular polymer solution after coupling the carbon nanotube blended conductive membrane of Example 1 with electrically activated peracetic acid. DETAILED DESCRIPTION

[0046] In order to better understand the technical solution of the present invention, the present invention is further described in detail below through three embodiments. However, the following embodiments are only simplified examples of the present invention and are not limited to the following embodiments.

[0047] Unless otherwise specified, the materials used in the examples of the present invention can be obtained from commercial sources or prepared according to conventional methods well known to those skilled in the art.

[0048] Example 1

[0049] The preparation method of the carbon nanotube blended conductive film specifically comprises the following steps:

[0050] (1) Oxygen functional group modification of carbon nanotubes

[0051] The carbon nanotubes were evenly distributed in a crystallization dish and placed in an oxygen plasma generator. The plasma radio frequency power was 50 W, the radio frequency frequency was 13.56 MHz, the pressure in the chamber was 60 Pa, the modification time was 20 s, and the reaction was repeated 3 times to obtain oxygen functional group-modified carbon nanotubes with an oxygen content of 0.2 wt%.

[0052] (2) Preparation of casting solution

[0053] According to the mass ratio of oxygen functional group modified carbon nanotubes, polyethersulfone, polyvinyl pyrrolidone and polyethylene glycol of 2:3:1:1, oxygen functional group modified carbon nanotubes, polyethersulfone and polyvinyl pyrrolidone were added to N, N-dimethylacetamide, and stirred uniformly at room temperature for 24 hours to obtain a dispersion liquid, and then polyethylene glycol was added at a constant temperature of 55°C, stirred until completely dissolved, and then allowed to stand for 24 hours for degassing to obtain a casting solution. The electron photograph of the casting solution is shown as follows: Figure 1 As shown;

[0054] (3) Preparation of basement membrane

[0055] A flat-plate scraper was fixed with a scraping gap of 300 μm. 20 mL of casting solution was poured onto one end of the glass plate with the scraper. The casting solution was evenly applied to the glass plate using the scraper at a constant speed of 5 cm / s. The glass film coated with the casting solution was immersed in a coagulation bath of an aqueous solution of N,N-dimethylacetamide (wt.%) for 30 minutes to complete the curing of the base film.

[0056] (4) In situ cross-linking of basement membrane

[0057] The cured base membrane was transferred from the coagulation bath to deionized water and soaked at a constant temperature of 60°C for 0.5h, during which the water was changed 3 times to remove residual solvent and pore-forming agent polyethylene glycol; the base membrane was placed in a mixture of aniline and sodium polystyrene sulfonate (PSS) (the mass ratio of aniline to PSS was 1:1, and the aniline concentration was 1.0wt%), soaked at 4°C for 30min, taken out and immersed in 0.16mol / L ammonium persulfate solution again, reacted for 5min, and then placed at 4°C to react for 6h, then taken out and placed in an acidic solution of glutaraldehyde (the solvent was hydrochloric acid, and the concentration of glutaraldehyde was 2wt%) for cross-linking for 30min, then washed with pure water and soaked in pure water.

[0058] The conductive membrane prepared in Example 1 has a molecular weight cut-off of 150 kDa and a conductivity of 16 S / m. Figure 2 This is a digital photo of the separation membrane, and the surface is intact and without defects.

[0059] Example 2

[0060] The preparation method of the carbon nanotube blended conductive film specifically comprises the following steps:

[0061] (1) Oxygen functional group modification of carbon nanotubes

[0062] The carbon nanotubes were evenly distributed in a crystallization dish and placed in an oxygen plasma generator. The plasma radio frequency power was 100 W, the radio frequency frequency was 13.56 MHz, the pressure in the chamber was 100 Pa, the modification time was 10 s, and this was repeated 3 times to obtain oxygen functional group-modified carbon nanotubes, wherein the oxygen content was 0.2 wt%;

[0063] (2) Preparation of casting solution

[0064] According to the mass ratio of oxygen functional group-modified carbon nanotubes, polyethersulfone, polyvinyl pyrrolidone and polyethylene glycol of 2:3:1:1, oxygen functional group-modified carbon nanotubes, polyethersulfone and polyvinyl pyrrolidone were added to N,N-dimethylacetamide, and stirred at room temperature for 18 hours to obtain a dispersion liquid, and then polyethylene glycol was added at a constant temperature of 70°C, stirred until completely dissolved, and then allowed to stand for 12 hours for degassing to obtain a casting solution;

[0065] (3) Preparation of basement membrane

[0066] A flat-plate scraper with a fixed scraping gap of 500 μm was used to pour 40 mL of casting solution onto one end of the glass plate. The casting solution was evenly applied to the glass plate using the scraper at a constant speed of 6 cm / s. The glass film coated with the casting solution was immersed in a coagulation bath of an aqueous solution of N,N-dimethylacetamide (wt.%) for 60 minutes to complete the curing of the base film.

[0067] (4) In situ cross-linking of basement membrane

[0068] The cured base membrane was transferred from the coagulation bath to deionized water and soaked at a constant temperature of 60°C for 1 hour, during which the water was changed 5 times to remove residual solvent and pore-forming agent polyethylene glycol; the base membrane was placed in a mixture of aniline and sodium polystyrene sulfonate (PSS) (the mass ratio of aniline to PSS was 1:1, and the aniline concentration was 1.0wt%), and soaked at 4°C for 30 minutes. After that, it was taken out and immersed in 0.16mol / L ammonium persulfate solution again, reacted for 10 minutes, and then placed at 4°C to react for 6 hours. Subsequently, it was taken out and placed in an acidic solution of glutaraldehyde (the solvent was hydrochloric acid, and the concentration of glutaraldehyde was 2wt%) for cross-linking for 45 minutes, and then washed with pure water and soaked in pure water.

[0069] The conductive membrane prepared in Example 2 has a molecular weight cut-off of 100 kDa and a conductivity of 22 S / m.

[0070] Example 3

[0071] The preparation method of the carbon nanotube blended conductive film specifically comprises the following steps:

[0072] (1) Oxygen functional group modification of carbon nanotubes

[0073] The carbon nanotubes were evenly distributed in a crystallization dish and placed in an oxygen plasma generator. The plasma radio frequency power was 80W, the radio frequency frequency was 13.56MHz, the pressure in the chamber was 60Pa, the modification time was 15s, and the reaction was repeated three times to obtain oxygen functional group-modified carbon nanotubes with an oxygen content of 0.2wt%.

[0074] (2) Preparation of casting solution

[0075] According to the mass ratio of oxygen functional group-modified carbon nanotubes, polyethersulfone, polyvinyl pyrrolidone and polyethylene glycol of 2:3:1:1, oxygen functional group-modified carbon nanotubes, polyethersulfone and polyvinyl pyrrolidone were added to N,N-dimethylacetamide, and stirred at room temperature for 36 hours to obtain a dispersion liquid, and then polyethylene glycol was added at a constant temperature of 60°C, stirred until completely dissolved, and then allowed to stand for 24 hours for degassing to obtain a casting solution;

[0076] (3) Preparation of basement membrane

[0077] A flat-plate scraper with a fixed scraping gap of 450 μm was used. 30 mL of casting solution was poured onto one end of the glass plate with the scraper. The casting solution was evenly applied to the glass plate using the scraper at a constant speed of 7 cm / s. The glass film coated with the casting solution was immersed in a coagulation bath of an aqueous solution of N,N-dimethylacetamide (wt.%) for 30 minutes to complete the curing of the base film.

[0078] (4) In situ cross-linking of basement membrane

[0079] The cured base membrane was transferred from the coagulation bath to deionized water and soaked at a constant temperature of 45°C for 1 hour, during which the water was changed 5 times to remove residual solvent and pore-forming agent polyethylene glycol; the base membrane was placed in a mixture of aniline and sodium polystyrene sulfonate (PSS) (the mass ratio of aniline to PSS was 1:1, and the aniline concentration was 1.0wt%), and soaked at 4°C for 45 minutes. After that, it was taken out and immersed in ammonium persulfate solution again, reacted for 5 minutes, and then placed at 4°C to react for 4 hours. Subsequently, it was taken out and placed in an acidic solution of glutaraldehyde (the solvent was hydrochloric acid, and the concentration of glutaraldehyde was 2wt%) for cross-linking for 30 minutes, and then washed with pure water and soaked in pure water.

[0080] The conductive membrane prepared in Example 3 has a molecular weight cut-off of 200 kDa and a conductivity of 10.4 S / m.

[0081] Application Example 1

[0082] The conductive membrane prepared in Example 1 was used as a membrane electrode and coupled with electro-activated peracetic acid to treat water. The total organic carbon concentration was 10 mg L -1 The algal extracellular polymer solution is used as the raw solution to be processed, which specifically includes the following steps:

[0083] (1) The conductive membrane is encapsulated in a flat membrane assembly, with the membrane serving as the working electrode. A counter electrode metal mesh of the same area is placed opposite the membrane inside the assembly. The distance between the metal mesh and the flat membrane is 8 mm. Wires are drawn from the metal mesh, and the metal electrode clips and wires are connected to the conductive membrane. The two-stage wires are connected to an external DC regulated power supply.

[0084] (2) adding 2 mg / L of peracetic acid to the raw liquid to be treated, and applying voltage to the conductive membrane through a DC regulated power supply to filter the liquid. The filtration method is cross-flow filtration, and the filtration pressure of the membrane assembly is adjusted to be constant at 1.0 bar;

[0085] (3) Under the condition of a cross-flow velocity of 0.05 m / s, the conductive membrane has good anti-pollution performance. A voltage of 2.0 V is applied to the conductive membrane and the filtration is carried out for 2 h. Figure 4 The flux decrease curve of the algal extracellular polymer solution during filtration is shown in Figure 2. The flux only dropped from 100 L m to 100 L m within 2 h. -2 h -1 bar -1 Down to 90.4L m -2 h -1 bar -1 , the flux drop rate is less than 10%, showing good anti-pollution performance. Figure 5 The removal effect of microcystin by the conductive membrane filtration process. The concentration of microcystin in the raw water is 2.7 μg L -1 When no voltage was applied to the conductive membrane, the concentration of microcystin in the effluent was 1.6 μg L -1 When a voltage of 2.0 V was applied to the conductive membrane, the concentration of microcystin in the effluent was lower than the detection limit (0.01 μg L -1 ), the removal rate is about 100%.

[0086] Application Example 2

[0087] The conductive membrane prepared in Example 2 was used as a membrane electrode and coupled with electro-activated peracetic acid to treat water. -1 Humic acid solution with a total organic carbon concentration of 5 mg L -1 The mixed solution of the algal extracellular polymer solution is used as the simulated algal contaminated water to be treated, specifically comprising the following steps:

[0088] (1) The conductive membrane is encapsulated in a flat membrane assembly, with the membrane serving as the working electrode. A counter electrode metal mesh of the same area is placed opposite the membrane inside the assembly. The distance between the metal mesh and the flat membrane is 8 mm. Wires are drawn from the metal mesh, and the metal electrode clips and wires are connected to the conductive membrane. The two-stage wires are connected to an external DC regulated power supply.

[0089] (2) adding 5 mg / L of peracetic acid to the raw liquid to be treated, and applying voltage to the conductive membrane through a DC regulated power supply to filter the liquid. The filtration method is cross-flow filtration, and the filtration pressure of the membrane assembly is adjusted to be constant at 1.0 bar;

[0090] (3) Under the cross-flow velocity condition of 0.08 m / s, the conductive membrane has good anti-pollution performance. When a voltage of 2.5 V is applied to the conductive membrane, the flux decreases by only 14% after 2 hours of filtration, and the pollutant removal rate in the simulated algae-contaminated water is 94.2%.

[0091] Application Example 3

[0092] The conductive membrane prepared in Example 3 was used as a membrane electrode and coupled with electroactivated peracetic acid to treat water. Surface water contaminated by algae was used as the treated liquid, and its permanganate index was 4.2 mg L -1 The concentration of microcystin was 1.4 μg L -1 , the turbidity is 2.3NTU, specifically including the following steps:

[0093] (1) The conductive membrane is encapsulated in a flat membrane assembly, with the membrane serving as the working electrode. A counter electrode metal mesh of the same area is placed opposite the membrane inside the assembly, with a distance of 10 mm between the metal mesh and the flat membrane. Wires are drawn from the metal mesh, and the metal electrode clips and wires are connected to the conductive membrane. The two-stage wires are connected to an external DC regulated power supply.

[0094] (2) adding 1.5 mg / L of peracetic acid to the raw liquid to be treated, and applying voltage to the conductive membrane through a DC regulated power supply to filter the liquid. The filtration method is cross-flow filtration, and the filtration pressure of the membrane assembly is adjusted to be constant at 0.5 bar.

[0095] (3) Under the condition of a cross-flow velocity of 0.02 m / s, the conductive membrane has good anti-pollution performance. When a voltage of 2.5 V is applied to the conductive membrane, the flux decreases by only 12% after 2 hours of filtration. The removal rate of permanganate is 81.1%, and the removal rate of microcystin detected in algae-contaminated surface water is 100%.

[0096] The embodiments described above are only typical embodiments of the present invention and do not constitute an improper limitation of the present invention. Therefore, all obvious modifications described in the scope of the patent application of the present invention, as well as other modifications that do not deviate from the essence of the present invention, should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a carbon nanotube blended conductive film, characterized in that: The steps are as follows: (1) Oxygen functional group modification of carbon nanotubes The carbon nanotubes are evenly distributed in a crystallization dish and placed in an oxygen plasma generator for treatment to obtain carbon nanotubes modified with oxygen functional groups; (2) Preparation of casting solution Adding oxygen functional group-modified carbon nanotubes, polyethersulfone and polyvinylpyrrolidone to a solvent, stirring uniformly at room temperature for 18 to 36 hours to obtain a dispersion, then adding polyethylene glycol at a constant temperature of 50 to 80°C, stirring until completely dissolved, and then standing to degas to obtain a casting solution; (3) Preparation of basement membrane The casting solution was applied to the glass plate, and the glass plate coated with the casting solution was immersed in a coagulation bath for 30 minutes to complete the curing of the base film; (4) In situ cross-linking of basement membrane The solidified base film is transferred from the coagulation bath to deionized water for soaking and washing, and the base film is placed in a mixture of aniline and sodium poly(p-styrene sulfonate) and soaked at 4°C for 20 to 30 minutes. The base film is then taken out and immersed in an ammonium persulfate solution to react for 5 to 10 minutes. The base film is then placed at 4°C to react for 3 to 6 hours. The base film is then taken out and placed in an acidic solution of glutaraldehyde for cross-linking. The base film is then washed with pure water and soaked in pure water to obtain a carbon nanotube blended conductive film.

2. The preparation method according to claim 1, characterized in that In step (1), the oxygen content of the carbon nanotubes modified with oxygen functional groups is 0.1 to 0.5 wt %; The plasma radio frequency power is 50 to 100 W, the radio frequency frequency is 13.56 MHz, the gas pressure in the chamber is 50 to 100 Pa, and the processing time is 10 to 60 s.

3. The preparation method according to claim 1, characterized in that In step (2), the solvent is one or a mixture of two of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide; The molecular weight of the polyethylene glycol is 50,000 to 300,000.

4. The preparation method according to claim 1, characterized in that In step (2), the mass fraction of the solute in the casting solution is 30 to 60%.

5. The preparation method according to claim 1, characterized in that In step (2), in the casting solution, the mass ratio of oxygen functional group-modified carbon nanotubes, polyethersulfone, polyvinyl pyrrolidone, and polyethylene glycol is (2-3):3:1:

1.

6. The preparation method according to claim 1, characterized in that In step (3), the flat film scraper has a scraping gap of 300 to 500 μm and is scraped at a constant speed of 5 to 10 cm / s; The coagulation bath is a 10-20 wt% N,N-dimethylacetamide aqueous solution, and the temperature of the coagulation bath is 20-25°C.

7. The preparation method according to claim 1, characterized in that In step (4), the basement membrane is soaked and washed at a constant temperature of 40 to 60° C. for 0.5 to 1 hour; The cross-linking time of the glutaraldehyde is 30 to 60 minutes.

8. The preparation method according to claim 1, characterized in that In step (4), in the mixed solution of aniline and sodium poly(p-styrene sulfonate), the mass ratio of aniline to sodium poly(p-styrene sulfonate) is 1:1, and the concentration of aniline is 0.5-2.0 wt%.

9. A carbon nanotube blended conductive film obtained by the preparation method according to any one of claims 1 to 8.

10. A method for controlling algae pollution by coupling carbon nanotube blended conductive membrane with electroactivated peracetic acid, characterized in that: The carbon nanotube blended conductive membrane described in claim 9 is used as a membrane electrode. During the treatment of algae-contaminated water, peracetic acid is added to the influent at a concentration of 0.5 to 5 mg / L, a voltage of 0.5 to 3 V is applied to the membrane, the filtration form is constant pressure cross-flow filtration, the filtration pressure is 0.5 to 2.0 bar, and the cross-flow velocity is 0.05 to 0.1 m / s.

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