A method for preparing nanofibers for oil-containing wastewater adsorption and oil removal

Abstract

The invention discloses a method for preparing nanofibers for oil-containing sewage adsorption and oil removal, and specifically relates to the technical field of nanofiber material preparation. The invention uses polystyrene or polyacrylonitrile as a fiber structure carrier, and encapsulates aluminum isooctanoate and chitosan as lipophilic adsorption components. Polystyrene and polyacrylonitrile have good light and heat stability. The prepared fibers are relatively loose and can provide larger fiber gaps. In addition, both fibers are insoluble in water and can maintain the original structural strength in water. Aluminum isooctanoate is encapsulated in the fibers, and its exposed aluminum-oxygen bonds are easily combined in the fibers, thereby increasing the complexity of the fiber network structure and facilitating the encapsulation of oil droplets. The chitosan in the fibers is easily protonated at free amino groups in an aqueous solution, so that the fibers are positively charged, and the electrical properties of oil droplet colloid particles can be effectively neutralized, and the charged colloid particles can be adsorbed. The above three components are used in combination to effectively improve the treatment effect of oil-containing sewage.

Description

Technical Field

[0001] The present invention relates to the technical field of nanofiber material preparation, and more specifically, to a method for preparing nanofiber for oil-containing wastewater adsorption and oil removal. Background Art

[0002] Oil enters the water environment through different pathways to form oily wastewater. Oily wastewater is a large-volume, widespread and seriously harmful wastewater, and its sources are many. For example: oil extraction and oil processing, refining, storage and transportation in the petroleum industry. In the treatment process of oily wastewater, flocculation treatment is an important water treatment method, which occupies an important position in water treatment, and its efficiency affects the treatment effect of the entire subsequent process. Flocculant is a kind of agent that causes colloidal particles in water to aggregate to form flocs, thereby accelerating particle coagulation and achieving disinfection, sterilization, decolorization, purification and other effects. Existing flocculation methods have the disadvantages of slow floc sedimentation, easy to cause secondary pollution, serious scaling of inlet and outlet pipelines, dissolved gas cylinders, etc., and difficult to remove.

[0003] Currently common adsorption materials include non-woven fabrics, oil absorbent felt, sponges, sacks, activated carbon, etc., but there are still problems such as low oil absorption rate. Summary of the invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for preparing nanofibers for oil-containing wastewater adsorption and oil removal. The technical problem to be solved by the present invention is: the current common adsorption materials include non-woven fabrics, oil absorbent felt, sponges, sacks, activated carbon, etc., but there is still a problem of low oil absorption rate.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing nanofibers for oil-containing wastewater adsorption and oil removal, comprising the following steps:

[0006] (1) preparing a spinning solution: dissolving a polymer material, aluminum isooctanoate, and chitosan in an organic solvent A, stirring until uniformly dissolved, adding an organic solvent B, and stirring uniformly to obtain a spinning solution;

[0007] (2) injecting the spinning solution described in step (1) into a spinning syringe, selecting a No. 19 spinning needle, and connecting it to the positive electrode of a power supply; performing electrospinning to prepare a fiber material; and obtaining a fiber material sample;

[0008] (3) After the samples were collected, they were dried in a vacuum oven at 40°C for 1 day to obtain the finished nanofiber material;

[0009] The nanofibers are in a network structure and have large porosity.

[0010] As a further solution of the present invention: the polymer material in step (1) is polyacrylonitrile or polystyrene.

[0011] As a further solution of the present invention: the mass ratio of the polymer material, aluminum isooctanoate and chitosan in step (1) is 7:1.5:1.5, wherein the total mass concentration of the polymer material, aluminum isooctanoate and chitosan in the spinning solution is 180-250 g / L.

[0012] As a further embodiment of the present invention, the organic solvent A in step (1) is N,N-dimethylformamide, the organic solvent B is acetone or tetrahydrofuran, and the ratio of A to B (volume ratio) is 3.5-4.5:6. The stirring process in step (1) is carried out using a stirrer, the stirring speed is controlled at 1300 r / min, and the stirring time is 25-35 min.

[0013] As a further solution of the present invention: the spinning parameters in step (2) are: spinning voltage 12-15 kV, receiving distance 15-25 cm, and spinning solution flow rate 2-5 ml / h.

[0014] The beneficial effects of the present invention are:

[0015] 1. The present invention uses polystyrene or polyacrylonitrile as a fiber structure carrier, and encapsulates aluminum isooctanoate and chitosan as lipophilic adsorption components. Polystyrene and polyacrylonitrile have good light and heat stability, and the prepared fibers are relatively loose and can provide larger fiber gaps. In addition, both fibers are insoluble in water and can maintain their original structural strength in water. Aluminum isooctanoate is encapsulated in the fiber, and its exposed aluminum-oxygen bonds are easily combined in the fiber, which increases the complexity of the fiber network structure and is beneficial to the encapsulation of oil droplets; the chitosan in the fiber is easy to protonate free amino groups in aqueous solution, so that the fiber is positively charged, which can effectively neutralize the electrical properties of oil droplet particles and adsorb charged particles; the above three components are used in combination to effectively improve the treatment effect of oily wastewater.

[0016] 2. The electrospun polymer nanofibers provided by the present invention have a three-dimensional network structure, a large specific surface area and a high porosity, and combined with the function of adsorbing active substances, can effectively improve the oil-water separation efficiency.

[0017] 3. The oil-containing wastewater adsorption and oil removal nanofiber provided by the present invention has a high structural strength. Aluminum isooctanoate and chitosan directly form an integrated structure with the fiber. After use, a long sedimentation time is not required, and filtering treatment is avoided. The method is simple and secondary pollution is reduced.

[0018] 4. In the present invention, since the electrospinning technology is simple to operate, has a wide range of polymer sources, and the nanofibers prepared by electrospinning have the advantages of small diameter, high porosity, and large specific surface area, the electrospun nanofibers are made into nanofiber adsorption materials, which have the advantages of small overall density and high porosity. Combined with the controllable modification technology of the special wetting properties of the fiber surface, it has great development potential and application value in the field of sewage treatment. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Embodiment 1:

[0021] A method for preparing nanofibers for oil-containing wastewater adsorption and oil removal, comprising the following steps:

[0022] (1) Preparation of nanofibers: Weigh 0.30 g of aluminum octoate and chitosan, respectively, and dissolve them in 4.0 ml of N,N-dimethylformamide; when the solute is completely dissolved, add 1.40 g of polystyrene with an average molecular weight of 180,000 as a matrix polymer, add 6 ml of tetrahydrofuran to the mixed solution, heat and stir at 40°C for 1 hour; load the spinning solution into a spinning syringe with a No. 19 needle; adjust the distance from the needle tip to the roller to 15 cm, adjust the voltage to 13 kV, and maintain the flow rate at 2.0 ml / h. After the sample is collected, dry it in a vacuum oven at 40°C for 1 day.

[0023] (2) Take 1.5 g of crude oil and 1500 ml of tap water, emulsify and stir at a high speed of 8000 r / min for 20 min to obtain an oily wastewater sample.

[0024] (3) Take 100 ml of oily wastewater, cut 1.0 g of nanofibers, place them into the wastewater and stir at room temperature for 1 hour. Use a glass rod to remove the fiber material, and keep the water sample for subsequent treatment.

[0025] (4) 100 ml of the oily wastewater was extracted with 100 ml of n-hexane, dried over anhydrous sodium sulfate, transferred to a 100 ml volumetric flask, fixed to volume with n-hexane, and set as sample 1; the oily wastewater sample treated in step (3) was extracted with 100 ml of n-hexane, dried over anhydrous sodium sulfate, transferred to a 100 ml volumetric flask, fixed to volume with n-hexane, and set as sample 2.

[0026] (5) The absorbance was measured using a UV-visible spectrophotometer, with an absorbance of 281 nm as the test wavelength. Sample 1 was diluted 5 times with n-hexane, and 2.5 ml was taken to measure the absorbance, which was 1.423. Sample 2 was diluted 5 times with n-hexane, and 2.5 ml was taken to measure the absorbance, which was 0.289. The oil removal rate was calculated to be 79.69%.

[0027] Embodiment 2:

[0028] A method for preparing nanofibers for oil-containing wastewater adsorption and oil removal, comprising the following steps:

[0029] (1) Preparation of nanofibers: Weigh 0.30 g of aluminum octoate and chitosan, respectively, and dissolve them in 3.5 ml of N,N-dimethylformamide; when the solute is completely dissolved, add 1.40 g of polystyrene with an average molecular weight of 180,000 as a matrix polymer, add 6 ml of tetrahydrofuran to the mixed solution, heat and stir at 40°C for 1 hour; load the spinning solution into a spinning syringe with a No. 19 needle; adjust the distance from the needle tip to the roller to 15 cm, adjust the voltage to 13 kV, and maintain the flow rate at 2.0 ml / h. After the sample is collected, dry it in a vacuum oven at 40°C for 1 day.

[0030] (2) Take 1.5 g of crude oil and 1500 ml of tap water, emulsify and stir at a high speed of 8000 r / min for 20 min to obtain an oily wastewater sample.

[0031] (3) Take 100 ml of oily wastewater, cut 1.0 g of nanofibers, place them into the wastewater and stir at room temperature for 1 hour. Use a glass rod to remove the fiber material, and keep the water sample for subsequent treatment.

[0032] (4) Take the oily wastewater sample after treatment in step (3), extract it with 100 ml of n-hexane, dry it with anhydrous sodium sulfate, transfer it to a 100 ml volumetric flask, make up the volume with n-hexane, and set it as the sample.

[0033] (5) The absorbance was measured using a UV-visible spectrophotometer, with an absorbance of 281 nm as the test wavelength. The sample was diluted 5 times with n-hexane, and 2.5 ml was taken and the absorbance was measured to be 0.326.

[0034] Embodiment 3:

[0035] A method for preparing nanofibers for oil-containing wastewater adsorption and oil removal, comprising the following steps:

[0036] (1) Preparation of nanofibers: Weigh 0.30 g of aluminum octoate and chitosan, respectively, and dissolve them in 3.7 ml of N,N-dimethylformamide; when the solute is completely dissolved, add 1.40 g of polystyrene with an average molecular weight of 180,000 as a matrix polymer, add 6 ml of tetrahydrofuran to the mixed solution, heat and stir at 40°C for 1 hour; load the spinning solution into a spinning syringe with a No. 19 needle; adjust the distance from the needle tip to the roller to 15 cm, adjust the voltage to 13 kV, maintain the flow rate at 2.0 ml / h, and dry the sample in a vacuum oven at 40°C for 1 day.

[0037] (2) Take 1.5 g of crude oil and 1500 ml of tap water, emulsify and stir at a high speed of 8000 r / min for 20 min to obtain an oily wastewater sample.

[0038] (3) Take 100 ml of oily wastewater, cut 1.0 g of nanofibers, place them into the wastewater and stir at room temperature for 1 hour. Use a glass rod to remove the fiber material, and keep the water sample for subsequent treatment.

[0039] (4) Take the oily wastewater sample after treatment in step (3), extract it with 100 ml of n-hexane, dry it with anhydrous sodium sulfate, transfer it to a 100 ml volumetric flask, make up the volume with n-hexane, and set it as the sample.

[0040] (5) The absorbance was measured using a UV-visible spectrophotometer, with an absorbance of 281 nm as the test wavelength. The sample was diluted 5 times with n-hexane, and 2.5 ml was taken and the absorbance was measured to be 0.389.

[0041] Embodiment 4:

[0042] A method for preparing nanofibers for oil-containing wastewater adsorption and oil removal, comprising the following steps:

[0043] (1) Preparation of nanofibers: Weigh 0.30 g of aluminum octoate and chitosan, respectively, and dissolve them in 4.0 ml of N,N-dimethylformamide; when the solute is completely dissolved, add 1.40 g of polystyrene with an average molecular weight of 180,000 as a matrix polymer, add 6 ml of tetrahydrofuran to the mixed solution, heat and stir at 40°C for 1 hour; load the spinning solution into a spinning syringe with a No. 19 needle; adjust the distance from the needle tip to the roller to 15 cm, adjust the voltage to 13 kV, and maintain the flow rate at 2.0 ml / h. After the sample is collected, dry it in a vacuum oven at 40°C for 1 day.

[0044] (2) Take 1.5 g of crude oil and 1500 ml of tap water, emulsify and stir at a high speed of 8000 r / min for 20 min to obtain an oily wastewater sample.

[0045] (3) Take 100 ml of oily wastewater, cut 1.0 g of nanofibers, place them into the wastewater and stir at room temperature for 1 hour. Use a glass rod to remove the fiber material, and keep the water sample for subsequent treatment.

[0046] (4) Take the oily wastewater sample after treatment in step (3), extract it with 100 ml of n-hexane, dry it with anhydrous sodium sulfate, transfer it to a 100 ml volumetric flask, make up the volume with n-hexane, and set it as the sample.

[0047] (5) The absorbance was measured using a UV-visible spectrophotometer, with an absorbance of 281 nm as the test wavelength. The sample was diluted 5 times with n-hexane, and 2.5 ml was taken and the absorbance was measured to be 0.289.

[0048] Example 5

[0049] A method for preparing nanofibers for oil-containing wastewater adsorption and oil removal, comprising the following steps:

[0050] (1) Preparation of nanofibers: Weigh 0.30 g of aluminum octoate and chitosan, respectively, and dissolve them in 4.5 ml of N,N-dimethylformamide; when the solute is completely dissolved, add 1.40 g of polystyrene with an average molecular weight of 180,000 as a matrix polymer, add 6 ml of tetrahydrofuran to the mixed solution, heat and stir at 40°C for 1 hour; load the spinning solution into a spinning syringe with a No. 19 needle; adjust the distance from the needle tip to the roller to 15 cm, adjust the voltage to 13 kV, maintain the flow rate at 2.0 ml / h, and dry the sample in a vacuum oven at 40°C for 1 day after collection.

[0051] (2) Take 1.5 g of crude oil and 1500 ml of tap water, emulsify and stir at a high speed of 8000 r / min for 20 min to obtain an oily wastewater sample.

[0052] (3) Take 100 ml of oily wastewater, cut 1.0 g of nanofibers, place them into the wastewater and stir at room temperature for 1 hour. Use a glass rod to remove the fiber material, and keep the water sample for subsequent treatment.

[0053] (4) Take the oily wastewater sample after treatment in step (3), extract it with 100 ml of n-hexane, dry it with anhydrous sodium sulfate, transfer it to a 100 ml volumetric flask, make up the volume with n-hexane, and set it as the sample.

[0054] (5) The absorbance was measured using a UV-visible spectrophotometer, with an absorbance of 281 nm as the test wavelength. The sample was diluted 5 times with n-hexane, and 2.5 ml was taken and the absorbance was measured to be 0.323.

[0055] The present invention uses polystyrene or polyacrylonitrile as a fiber structure carrier, and isooctylated aluminum and chitosan are coated as lipophilic adsorption components. Polystyrene and polyacrylonitrile have good light and heat stability, and the prepared fiber is relatively loose, which can provide a larger fiber gap. In addition, both fibers are insoluble in water and can maintain the original structural strength in the water body. Isooctanoic acid aluminum is coated in the fiber, and its exposed aluminum-oxygen bonds are easily combined in the fiber, increasing the complexity of the fiber mesh structure, which is conducive to the encapsulation of oil droplets; the chitosan in the fiber is prone to protonation of free amino groups in aqueous solution, making the fiber positively charged, which can effectively neutralize the electrical properties of oil droplet particles and adsorb charged particles. The above three components are used in combination to effectively improve the treatment effect of oily wastewater.

[0056] The electrospun polymer nanofibers provided by the present invention have a three-dimensional network structure, a large specific surface area and a high porosity, and can effectively improve the oil-water separation efficiency by combining the function of adsorbing active substances.

[0057] The oil-containing wastewater adsorption and oil removal nanofiber provided by the present invention has high structural strength, aluminum isooctanoate and chitosan directly form an integrated structure with the fiber, does not require a long sedimentation time after use, avoids filtering treatment, has a simple method, and reduces secondary pollution.

[0058] The present invention, since the electrospinning technology has the advantages of simple operation, wide source of polymers, and the nanofibers prepared by electrospinning have the advantages of small diameter, high porosity, large specific surface area, etc., the electrospun nanofibers are made into nanofiber adsorption materials, which have the advantages of small overall density, high porosity, etc., combined with the controllable modification technology of the special wetting properties of the fiber surface, it has great development potential and application value in the field of sewage treatment.

[0059] Finally, a few points should be explained: Although the present invention has been described in detail above with general descriptions and specific embodiments, on the basis of the present invention, the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing nanofibers for oil-containing wastewater adsorption and oil removal, characterized in that: The following steps are involved: (1) Preparing a spinning solution: dissolving a polymer material, aluminum isooctanoate and chitosan in an organic solvent A, stirring until uniformly dissolved, adding an organic solvent B, and stirring uniformly to obtain a spinning solution; The polymer material in step (1) is polyacrylonitrile or polystyrene; (2) injecting the spinning solution described in step (1) into the spinning syringe, selecting a No. 19 spinning needle, and connecting it to the positive electrode of the power supply; and performing electrospinning to prepare the fiber material; obtaining a fiber material sample; (3) After the samples were collected, they were dried in a vacuum oven at 40 °C for 1 day to obtain the finished nanofiber material; The nanofibers are in a network structure and have large porosity.

2. The method for preparing nanofibers for oil-containing wastewater adsorption and oil removal according to claim 1, characterized in that: The mass ratio of the polymer material, aluminum isooctanoate and chitosan in step (1) is 7: 1.5:1.5, wherein the total mass concentration of polymer material, aluminum isooctanoate and chitosan in the spinning solution is 180-250 g / L.

3. The method for preparing nanofibers for oil-containing wastewater adsorption and oil removal according to claim 1, characterized in that: The organic solvent A in the step (1) is N,N-dimethylformamide, the organic solvent B is acetone and tetrahydrofuran, the volume of the organic solvent A: the volume of the organic solvent B = 3.5-4.5:6, and the stirring process in the step (1) uses a stirrer, the stirring speed is controlled at 1300 r / min, and the stirring time is 25-35 min.

4. The method for preparing nanofibers for oil-containing wastewater adsorption and oil removal according to claim 1, characterized in that: The spinning parameters in step (2) are: spinning voltage 12-15 kV, receiving distance 15-25 cm, and spinning solution flow rate 2-5 ml / h.