A high-efficiency water purifier for treating oilfield wastewater and its preparation method

Abstract

The invention discloses a high-efficiency water purifier for treating oilfield sewage and a preparation method thereof, and relates to the technical field of oilfield sewage treatment. The high-efficiency water purifier for treating oilfield sewage comprises a composite synergistic factor, an infiltrating aerogel carrier material, and diesel-eating alkanes. The diesel-eating alkanes and the infiltrating aerogel carrier material are co-fermented and cultured to form a biofilm on the infiltrating aerogel carrier material, thereby enhancing the purification effect of a single bacterium or aerogel. Moreover, under the action of the composite synergistic factor, the environmental tolerance stability of the diesel-eating alkanes and the infiltrating aerogel carrier material is further enhanced, more adsorption sites are provided, and the adsorption capacity for various oils and suspended matter is significantly improved, thereby achieving an excellent oilfield sewage purification effect.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield sewage treatment, and specifically relates to a high-efficiency water purifier for treating oilfield sewage and a preparation method thereof. Background Art

[0002] Petroleum energy is one of the important resources for national economic development and national defense strategy. It is known as the lifeline of the industrial economy and plays a vital role in my country's modernization development. my country's demand for oil is increasing with the development of the economy. In order to meet the oil supply, domestic oil fields are constantly increasing their exploitation efforts. Chemical flooding technology can improve oil recovery and achieve sustainable and stable exploitation of my country's oil fields. However, the oilfield wastewater produced by this technology contains a large amount of polymers, alkalis and surfactants; among them, polymers will increase the viscosity of the solution system, increase the spatial steric hindrance on the surface of the oil droplets, and reduce the floating rate of the oil droplets. The alkali can react with the acidic substances in the oil phase, and some of the generated surfactants will produce a synergistic effect with the original surfactants in the solution, increasing the interfacial activity of the oilfield wastewater system and enhancing the strength of the oil droplet interface film, reducing the interfacial tension and zeta potential on the surface of the oil droplets, making the chemical flooding wastewater system stable, and making it difficult to destabilize and separate the oil phase and the water phase, increasing the difficulty of treatment.

[0003] The existing technology currently has the following problems:

[0004] Commonly used water purifiers have a single action pathway and are unable to effectively remove grease and suspended solids from oilfield wastewater, resulting in poor purification effects. Summary of the Invention

[0005] In view of the above situation, in order to overcome the defects of the prior art, the present invention proposes a high-efficiency water purifier for treating oilfield wastewater, comprising the following components in parts by weight: 50-60 parts of a composite synergistic factor, 20-30 parts of a wettable aerogel carrier material, and 1-2 parts of diesel-eating bacteria.

[0006] The composite synergistic factor comprises the following components in parts by weight: 3-5 parts of UIO nanoparticles, 10-20 parts of polyethylene glycol, and 3-5 parts of transition metal carbide nanosheets.

[0007] The wettable aerogel carrier material comprises the following components in parts by weight: 10-20 parts of banana nanocellulose, 10-20 parts of methyltrimethoxysilane, and 5-10 parts of carboxyl modification liquid.

[0008] The preparation method of the composite synergistic factor specifically comprises the following steps:

[0009] (1) Dissolve zirconium chloride in a mixed solution of 0.6 mL of 37% hydrochloric acid solution and 5 mL of N, N-dimethylformamide, and ultrasonically treat for 20-30 min to obtain solution I. Then add 0.1-0.2 g of 2-aminoterephthalic acid to a mixed solution of 5 mL of acetic acid and 10 mL of N, N-dimethylformamide, and heat in an oil bath at 60-80 ° C for 20-30 min to obtain solution II. Then mix solution I and solution II, and stir at 100-120 ° C for 1-2 h. Collect the precipitate, wash it with N, N-dimethylformamide and anhydrous ethanol solution in sequence, and dry it to obtain the central metal ion Zr and the organic matter. The organic complex 2-aminoterephthalic acid is combined through coordination to form a three-dimensional porous framework material UIO-66-NH2 with an octahedral structure. Its high specific surface area and pore structure can physically adsorb grease and suspended matter in oilfield wastewater. The amino groups on the surface of UIO-66-NH2 enhance its hydrophilicity and chemical activity, making it easier to combine with grease and suspended matter, thereby enhancing adsorption performance. At the same time, the organic framework of MOF still has a certain degree of hydrophobicity, which also helps to adsorb hydrophobic grease. In addition, UIO-66-NH2 shows good stability under acid, alkali and high temperature conditions, making it suitable for complex oilfield wastewater environments, and thus obtaining UIO nanoparticles.

[0010] (2) Add 2.0-3.0 g of lithium fluoride to 20 mL of 37% hydrochloric acid solution, stir at 60-80 rpm, and slowly add 1.0-2.0 g of titanium aluminum carbide. After adding completely, stir at 30-40 ° C until it is completely dissolved, centrifuge, remove the upper liquid, and wash the precipitate with deionized water repeatedly by centrifugation until the pH is 7.0. The washed viscous precipitate is added to 50 mL of deionized water and ultrasonically treated in a nitrogen atmosphere for 3-4 hours. The obtained colloidal solution is centrifuged at 3000-4000 rpm for 0.5-1 hour. The upper colloidal solution is filtered into a thin film using a vacuum circulating water filter and dried. Transition metal carbide nanosheets have a large specific surface area and can provide more adsorption sites. Their surface is rich in functional groups such as hydroxyl and oxygen groups, which can form hydrogen bonds or electrostatic interactions with oils and suspended matter to enhance the adsorption effect. Therefore, oil droplets and suspended matter can be effectively removed by physical and chemical adsorption to obtain transition metal carbide nanosheets.

[0011] (3) Dissolve polyethylene glycol in 100 mL of deionized water, then add the transition metal carbide nanosheets described in step (2), ultrasonically treat for 20-30 min, then add the UIO nanoparticles described in step (1), first stir at a speed of 100-200 rpm for 0.5-1 h, then ultrasonically disperse for 1-2 h, centrifuge, and dry the precipitate. The UIO nanoparticles and the transition metal carbide nanosheets are self-assembled and connected through the hydrogen bonding action of polyethylene glycol to form a stable intercalated structure, which has excellent anti-swelling properties in oilfield wastewater. Among them, the insertion of UIO nanoparticles effectively increases the interlayer spacing between the transition metal carbide nanosheets, which not only reduces the aggregation of the transition metal carbide nanosheets, but also increases the permeation flux and the adsorption of oil and suspended matter, thereby improving the purification efficiency and obtaining a composite synergistic factor;

[0012] Preferably, in step (1), the amount of zirconium chloride added is 0.1-0.2 g, and the metal ion zirconium can decompose organic pollutants through chemical catalysis to improve the degradation efficiency;

[0013] Preferably, in step (3), the amount of polyethylene glycol added is 1.0-2.0 g. Polyethylene glycol effectively removes oil and suspended solids in oilfield wastewater treatment through flocculation, demulsification and solubilization, and is highly efficient, environmentally friendly and economical.

[0014] The present invention also provides a method for preparing a high-efficiency water purifier for treating oilfield wastewater, which specifically comprises the following steps:

[0015] S1. Grind the raw banana fiber, take out the chopped fiber and pass it through a 60-80 mesh sieve, wash the banana fiber powder with distilled water and dry it in an 80℃ oven, weigh 8.0-10.0g of the dried powder and place it in a Soxhlet extractor, add 100-200mL of a mixed solution of benzene and ethanol, wherein the volume ratio of benzene to ethanol is (1-2):1, extract it at 80-90℃ for 5-6h and then take it out. The extraction process can remove wax and pectin in the banana fiber. The extracted banana fiber is placed in a sodium chlorite solution with a mass fraction of 10% and a pH of 3.0, and bleached at 70-75℃ for 0.5-1h. Repeat this process 4-6 times, then wash it with distilled water and dry it. The bleaching process can remove lignin in the fiber through oxidation. The bleached banana fiber is added to a 5% by mass potassium hydroxide solution and degummed at 90-95°C for 1-2 hours to fully remove hemicellulose. The fiber is then washed and dried, and the degummed banana cellulose is added to 50 mL of distilled water, fully stirred, and nano-processed using an ultrasonic cell crusher, wherein the ultrasonic power is 1000-1500 W, the ultrasonic time is 20-30 minutes, and the fiber is freeze-dried. This process effectively removes the adverse effects of pectin, lignin, and hemicellulose, and prepares nano-level banana cellulose with a large specific surface area, which can provide more adsorption sites and is easier to surface modify, thereby enhancing the adsorption capacity of various types of oils and suspended matter to obtain banana nanocellulose.

[0016] S2, dispersing the banana nanocellulose described in step S1 in 100 mL of distilled water, adjusting the pH to 3.0, ultrasonically dispersing for 20-30 min, adding methyltrimethoxysilane to react for 1 h, transferring to a 70° C. oven for crosslinking for 1-2 h. The introduction of alkyl chains improves the hydrophobicity of the banana nanocellulose aerogel and increases its affinity for oils and fats, thereby improving the adsorption efficiency and purification effect, thereby obtaining an alkyl-modified banana nanocellulose aerogel;

[0017] S3, 8.6g succinic anhydride and 20.2mL 3-aminopropyltriethoxysilane were dissolved in 60mL N, N-dimethylformamide, and magnetically stirred at 40°C for 2-3h, followed by adding 2mL deionized water and continuing to stir for 1h to obtain a carboxyl-modified solution, and the alkyl-modified banana nanocellulose aerogel described in step S2 was immersed in the carboxyl-modified solution and cured for 5-6h. The introduction of carboxyl groups increased the hydrophilicity of the aerogel, and the charge interaction between the carboxyl groups and the surface of the suspended particles enhanced the adsorption capacity of the aerogel for suspended particles. Then, freeze-dried, alkyl modification and carboxyl modification respectively enhanced the adsorption capacity of the banana nanocellulose aerogel for grease and suspended particles, so that it can efficiently remove two types of pollutants at the same time, and endowed the aerogel with hydrophilic and lipophilic amphiphilicity, showing excellent wettability, and can fully contact with grease and suspended matter in oilfield wastewater, which helps to quickly penetrate and adsorb pollutants, improve the reaction rate and purification effect, and obtain a wettable aerogel carrier material;

[0018] S4, inoculate 1.0-2.0g of diesel-eating alkanes into a blue-mouthed bottle filled with 2216E culture medium and the infiltrative aerogel carrier material described in step S3 and culture for 36h. The high porosity of the infiltrative aerogel carrier material provides an ideal habitat for diesel-eating alkanes, and its heat-insulating and heat-preserving properties also help to maintain a suitable temperature for the growth and reproduction of diesel-eating alkanes, avoid the adverse effects of the external environment, and better protect the activity of the bacteria. Filter and remove the supernatant. Put the infiltrative aerogel carrier material containing diesel-eating alkanes into a fermentation tank, add 2216E culture medium to 80% of the tank volume, culture at 37°C for 7d, replace the 2216E culture medium in the tank every 1d, discard the supernatant after the culture is completed, freeze-dry, and finally mix with the composite synergistic factor. The rotation speed is 1000-2000 rpm, and the mixing time is 1-2 hours. At this time, the content of diesel-eating bacteria is 13-14 Log CFU / g. The infiltrated aerogel carrier material and the diesel-eating bacteria are fermented and cultured together, so that the diesel-eating bacteria forms a biofilm on the infiltrated aerogel carrier material. Not only is the purification ability of the infiltrated aerogel carrier material for grease and suspended matter enhanced, but the degradation effect of the diesel-eating bacteria is also effectively improved. In addition, the addition of the composite synergistic factor enhances the environmental tolerance of the diesel-eating bacteria and further increases the roughness of the infiltrated aerogel carrier material, providing more adsorption sites, which is conducive to better exerting the adsorption and decomposition effects of each component on grease and suspended matter, improving the purification effect, and obtaining a high-efficiency water purifier for treating oilfield wastewater.

[0019] Preferably, in step S2, the amount of methyltrimethoxysilane added is 1.0-2.0 g. The siloxane layer formed by methyltrimethoxysilane protects the banana nanocellulose from chemical erosion and improves its stability in oilfield wastewater.

[0020] Preferably, in step S4, the product number of the diesel-eating bacteria is BNCC186183. The diesel-eating bacteria is a bacterium that feeds on hydrocarbons and can degrade petroleum hydrocarbons, including diesel, crude oil, etc., and can also aggregate suspended matter in water through biological flocculation.

[0021] The beneficial effects achieved by the present invention are as follows:

[0022] The present invention forms a biofilm on the infiltrative aerogel carrier material by co-fermenting and culturing diesel-eating alkanes and a wettable aerogel carrier material, thereby enhancing the purification effect of a single bacterium or aerogel. Moreover, under the action of a composite synergistic factor, the environmental tolerance stability of diesel-eating alkanes and the wettable aerogel carrier material is further enhanced, more adsorption sites are provided, and the adsorption capacity for various greases and suspended matter is significantly improved, thereby achieving an excellent oilfield wastewater purification effect. In the composite synergistic factor, UIO nanoparticles and transition metal carbide nanosheets are self-assembled and connected through the hydrogen bonding action of polyethylene glycol to form a stable intercalation structure, which has excellent anti-swelling properties and a rich porous structure, can maintain a stable intercalation structure and pores, ensure efficient adsorption capacity, and can also resist the erosion of acids, alkalis and salts in oilfield wastewater, which is conducive to the stable and effective adsorption of grease and suspended particles. Among them, the insertion of UIO nanoparticles increases the interlayer spacing between transition metal carbide nanosheets, which not only reduces the aggregation of nanosheets, but also increases the permeation flux, thereby facilitating the increase in the adsorption amount of grease and suspended matter and improving the purification effect. In the material, the adsorption capacity of banana nanocellulose aerogel for oil and suspended particles is enhanced by alkyl modification and carboxyl modification, so that it can remove two types of pollutants efficiently at the same time, and endowed with banana nanocellulose aerogel with hydrophilic and lipophilic amphiphilicity, showing excellent wettability, and can fully contact with oil and suspended matter in oilfield wastewater, which is conducive to rapid penetration and adsorption of pollutants, and improves the reaction rate and purification effect; using the wettable aerogel carrier material as the growth carrier of diesel-eating alkanes is conducive to the reproduction and activity maintenance of the bacteria, and the addition of the composite synergistic factor not only enhances The environmental tolerance of the infiltrative aerogel carrier material containing diesel-eating bacteria is improved, and it can better resist the erosion of acids, alkalis, and salts in oilfield wastewater and the influence of high temperature. It also further increases the adsorption sites. The three work synergistically, and the adsorption function of a single component is fully optimized in the form of a combination of microorganisms and chemical materials, which significantly improves the purification treatment effect of oilfield wastewater. The present invention uses a composite synergistic factor, an infiltrative aerogel carrier material and diesel-eating bacteria to make a high-efficiency water purifier for treating oilfield wastewater, which can fully adsorb grease and suspended particles and has a high-efficiency purification treatment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a scanning electron microscope image of the composite synergistic factor prepared in Example 1 of the present invention;

[0024] Figure 2 This is a scanning electron microscope image of the high-efficiency water purifier for treating oilfield wastewater prepared in Example 1 of the present invention;

[0025] Figure 3 The oil removal rate results of Examples 1-4 and Comparative Examples 1-3 of the present invention are shown in FIG.

[0026] Figure 4 This is a graph showing the suspended matter removal rates of Examples 1-4 and Comparative Examples 1-3 of the present invention. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the present invention. The preferred embodiments and materials described herein are for illustrative purposes only and are not intended to limit the scope of this application.

[0029] The experimental methods in the following examples are conventional methods unless otherwise specified; the experimental materials used in the following examples are purchased from commercial channels unless otherwise specified.

[0030] Example 1

[0031] This embodiment provides a high-efficiency water purifier for treating oilfield wastewater, comprising the following components in parts by weight: 60 parts of a composite synergistic factor, 30 parts of a wettable aerogel carrier material, and 2 parts of diesel-eating bacteria.

[0032] The composite synergistic factor comprises the following components in parts by weight: 5 parts of UIO nanoparticles, 20 parts of polyethylene glycol, and 5 parts of transition metal carbide nanosheets.

[0033] The wettable aerogel carrier material comprises the following components in parts by weight: 20 parts of banana nanocellulose, 20 parts of methyltrimethoxysilane, and 8 parts of carboxyl modification liquid.

[0034] The preparation method of the composite synergistic factor specifically comprises the following steps:

[0035] (1) Dissolve zirconium chloride in a mixed solution of 0.6 mL of 37% hydrochloric acid solution and 5 mL of N, N-dimethylformamide. The amount of zirconium chloride added is 0.2 g. Metal ion zirconium can decompose organic pollutants by chemical catalysis and improve degradation efficiency. Ultrasonic treatment is performed for 30 min to prepare solution I. Then, 0.2 g of 2-aminoterephthalic acid is added to a mixed solution of 5 mL of acetic acid and 10 mL of N, N-dimethylformamide. Heat the mixture in an oil bath at 80 °C for 30 min to prepare solution II. Then, solution I and solution II are mixed and stirred at 120 °C for 2 h. The precipitate is collected and washed with N, N-dimethylformamide and anhydrous ethanol solution in sequence, and dried. The central metal ion Zr and the organic complex 2-aminoterephthalic acid are combined through coordination to form a three-dimensional porous framework material UIO-66-NH2 with an octahedral structure. Its high specific surface area and pore structure can physically adsorb grease and suspended matter in oilfield wastewater. The amino groups on the surface of UIO-66-NH2 enhance its hydrophilicity and chemical activity, making it easier to bind with grease and suspended matter, thereby enhancing its adsorption performance. At the same time, the organic framework of MOF still has a certain degree of hydrophobicity, which also helps to adsorb hydrophobic grease. In addition, UIO-66-NH2 shows good stability under acid, alkali and high temperature conditions, making it suitable for complex oilfield wastewater environments, and thus obtaining UIO nanoparticles.

[0036] (2) Add 3.0 g of lithium fluoride to 20 mL of 37% hydrochloric acid solution, stir at 80 rpm, and slowly add 2.0 g of titanium aluminum carbide. After adding completely, stir at 40 ° C until it is completely dissolved, centrifuge, remove the upper liquid, and wash the precipitate repeatedly with deionized water by centrifugation until the pH is 7.0. The washed viscous precipitate is added to 50 mL of deionized water and ultrasonically treated in a nitrogen atmosphere for 4 h. The obtained colloidal solution is centrifuged at 4000 rpm for 1 h. The upper colloidal solution is filtered into a thin film using a vacuum circulating water filter and dried. Transition metal carbide nanosheets have a large specific surface area and can provide more adsorption sites. Their surface is rich in functional groups such as hydroxyl and oxygen groups, which can form hydrogen bonds or electrostatic interactions with oils and suspended matter to enhance the adsorption effect. Therefore, oil droplets and suspended matter can be effectively removed by physical and chemical adsorption to obtain transition metal carbide nanosheets.

[0037] (3) Dissolve polyethylene glycol in 100 mL of deionized water. The amount of polyethylene glycol added is 2.0 g. Polyethylene glycol effectively removes oil and suspended solids in oilfield wastewater treatment through flocculation, demulsification and solubilization, and has the characteristics of high efficiency, environmental protection and economy. Then add the transition metal carbide nanosheets described in step (2) and ultrasonically treat for 30 minutes. Then add the UIO nanoparticles described in step (1). First, stir at 200 rpm for 1 hour, then ultrasonically disperse for 2 hours, centrifuge, and dry the precipitate. The UIO nanoparticles and transition metal carbide nanosheets are self-assembled and connected through the hydrogen bonding effect of polyethylene glycol to form a stable intercalated structure, which has excellent anti-swelling performance in oilfield wastewater. Among them, the insertion of UIO nanoparticles effectively increases the interlayer spacing between the transition metal carbide nanosheets, which not only reduces the aggregation of the transition metal carbide nanosheets, but also increases the permeation flux and the adsorption of oil and suspended solids, thereby improving the purification efficiency and obtaining a composite synergistic factor.

[0038] This embodiment provides a method for preparing a high-efficiency water purifier for treating oilfield wastewater, which specifically includes the following steps:

[0039] S1. The raw banana fiber was crushed and the crushed fiber was taken out and passed through an 80-mesh sieve. The banana fiber powder was washed with distilled water and dried in an 80-degree oven. 10.0 g of the dried powder was weighed and placed in a Soxhlet extractor. 200 mL of a mixed solution of benzene and ethanol was added, wherein the volume ratio of benzene to ethanol was 2:1. The mixture was extracted at 90°C for 6 h and then taken out. The extraction process can remove wax and pectin from the banana fiber. The extracted banana fiber was placed in a sodium chlorite solution with a mass fraction of 10% and a pH of 3.0, and bleached at 75°C for 1 h. This process was repeated 6 times, then washed with distilled water and dried. The bleaching process can remove lignin from the fiber by oxidation. The bleached banana fiber was then The banana cellulose was added to a 5% potassium hydroxide solution by mass and degummed at 95°C for 2 hours to fully remove the hemicellulose. The banana cellulose was then washed and dried, and then the degummed banana cellulose was added to 50 mL of distilled water, fully stirred, and nano-processed using an ultrasonic cell crusher. The ultrasonic power was 1500 W, the ultrasonic time was 30 minutes, and the banana was freeze-dried. This process effectively removed the adverse effects of pectin, lignin, and hemicellulose, and prepared nano-level banana cellulose with a large specific surface area, which can provide more adsorption sites and is easier to carry out surface modification, thereby enhancing the adsorption capacity of various types of oils and suspended matter to obtain banana nanocellulose.

[0040] S2, dispersing the banana nanocellulose described in step S1 in 100 mL of distilled water, adjusting the pH to 3.0, ultrasonically dispersing for 30 min, adding methyltrimethoxysilane for reaction for 1 h, the amount of methyltrimethoxysilane added is 2.0 g, the siloxane layer formed by methyltrimethoxysilane protects the banana nanocellulose from chemical corrosion and improves its stability in oilfield wastewater, transferring to a 70 ° C oven for crosslinking for 2 h, the introduction of alkyl chains improves the hydrophobicity of the banana nanocellulose aerogel and increases its affinity for oil and fat, thereby improving the adsorption efficiency and purification effect, thereby obtaining an alkyl-modified banana nanocellulose aerogel;

[0041] S3, 8.6g succinic anhydride and 20.2mL 3-aminopropyltriethoxysilane were dissolved in 60mL N, N-dimethylformamide, magnetically stirred at 40 ° C for 3h, then 2mL deionized water was added and stirred for 1h to obtain a carboxyl-modified solution, and the alkyl-modified banana nanocellulose aerogel described in step S2 was immersed in the carboxyl-modified solution and cured for 6h. The introduction of carboxyl groups increased the hydrophilicity of the aerogel, and the charge interaction between the carboxyl groups and the surface of the suspended particles enhanced the adsorption capacity of the aerogel for suspended particles. Then, freeze-dried, alkyl modification and carboxyl modification respectively enhanced the adsorption capacity of the banana nanocellulose aerogel for grease and suspended particles, so that it can efficiently remove two types of pollutants at the same time, and endowed the aerogel with hydrophilic and lipophilic amphiphilicity, showing excellent wettability, and can fully contact with grease and suspended matter in oilfield wastewater, which helps to quickly penetrate and adsorb pollutants, improve the reaction rate and purification effect, and obtain a wettable aerogel carrier material;

[0042] S4. Inoculate 2.0 g of diesel-eating alkanes in a blue-mouthed bottle filled with 2216E culture medium and the wettable aerogel carrier material described in step S3 and culture for 36 hours. The product number of diesel-eating alkanes is BNCC186183. Diesel-eating alkanes is a bacterium that feeds on hydrocarbons and can degrade petroleum hydrocarbons, including diesel and crude oil. It can also aggregate suspended matter in water through biological flocculation. The high porosity of the wettable aerogel carrier material provides an ideal habitat for diesel-eating alkanes, and its heat-insulating and heat-preserving properties also help maintain a suitable temperature for the growth and reproduction of diesel-eating alkanes, avoid the adverse effects of the external environment, and better protect the activity of the bacteria. Filter and remove the supernatant. Place the wettable aerogel carrier material containing diesel-eating alkanes in a fermentation tank, add 2216E culture medium to 80% of the tank volume, and culture at 37°C for 7 days, replacing the tank every 1 day. The 2216E culture medium in the culture medium was used. After the cultivation was completed, the supernatant was discarded, freeze-dried, and finally mixed with the composite synergistic factor at a mixing speed of 2000 rpm and a mixing time of 2 h. At this time, the content of diesel-eating bacteria was 14 Log CFU / g. The wettable aerogel carrier material and the diesel-eating bacteria were co-fermented and cultured, so that the diesel-eating bacteria formed a biofilm on the wettable aerogel carrier material. Not only was the purification ability of the wettable aerogel carrier material for grease and suspended matter enhanced, but the degradation effect of the diesel-eating bacteria was also effectively improved. In addition, the addition of the composite synergistic factor enhanced the environmental tolerance of the diesel-eating bacteria and further increased the roughness of the wettable aerogel carrier material, providing more adsorption sites, which was conducive to better exerting the adsorption and decomposition effects of each component on grease and suspended matter, improving the purification effect, and obtaining a high-efficiency water purifier for treating oilfield wastewater.

[0043] In this example, the prepared composite synergistic factor and the high-efficiency water purifier for treating oilfield wastewater were subjected to scanning electron microscopy to observe their microscopic morphology. Figure 1 This is a 5000-fold magnified SEM image of the composite synergistic factor prepared in Example 1. Figure 2 This is a 1000-fold magnified SEM image of the high-efficiency water purifier for treating oilfield wastewater prepared in Example 1. Figure 1 The composite synergistic factor prepared in this embodiment presents an intercalated structure of particles and nanosheets, such as Figure 2 The high-efficiency water purifier prepared in this embodiment for treating oilfield wastewater is in the form of a porous and rough film.

[0044] Example 2

[0045] This embodiment provides a high-efficiency water purifier for treating oilfield wastewater, comprising the following components in parts by weight: 50 parts of a composite synergistic factor, 20 parts of a wettable aerogel carrier material, and 1 part of diesel-eating bacteria.

[0046] The composite synergistic factor comprises the following components in parts by weight: 3 parts of UIO nanoparticles, 10 parts of polyethylene glycol, and 3 parts of transition metal carbide nanosheets.

[0047] The wettable aerogel carrier material comprises the following components in parts by weight: 10 parts of banana nanocellulose, 10 parts of methyltrimethoxysilane, and 5 parts of carboxyl modification liquid.

[0048] The preparation method of the composite synergistic factor specifically comprises the following steps:

[0049] (1) Dissolve zirconium chloride in a mixed solution of 0.6 mL of 37% hydrochloric acid solution and 5 mL of N, N-dimethylformamide. The amount of zirconium chloride added is 0.1 g. Metal ion zirconium can decompose organic pollutants by chemical catalysis and improve degradation efficiency. Ultrasonic treatment is carried out for 20 minutes to prepare solution I. Then, 0.1 g of 2-aminoterephthalic acid is added to a mixed solution of 5 mL of acetic acid and 10 mL of N, N-dimethylformamide. Heat the mixture in an oil bath at 60 ° C for 20 minutes to prepare solution II. Then, solution I and solution II are mixed and stirred at 100 ° C for 1 hour. The precipitate is collected and washed with N, N-dimethylformamide and anhydrous ethanol solution in sequence, and dried. The central metal ion Zr and the organic complex 2-aminoterephthalic acid are combined through coordination to form a three-dimensional porous framework material UIO-66-NH2 with an octahedral structure. Its high specific surface area and pore structure can physically adsorb grease and suspended matter in oilfield wastewater. The amino groups on the surface of UIO-66-NH2 enhance its hydrophilicity and chemical activity, making it easier to bind with grease and suspended matter, thereby enhancing its adsorption performance. At the same time, the organic framework of MOF still has a certain degree of hydrophobicity, which also helps to adsorb hydrophobic grease. In addition, UIO-66-NH2 shows good stability under acid, alkali and high temperature conditions, making it suitable for complex oilfield wastewater environments, and thus obtaining UIO nanoparticles.

[0050] (2) Add 2.0 g of lithium fluoride to 20 mL of 37% hydrochloric acid solution, stir at 60 rpm, and slowly add 1.0 g of titanium aluminum carbide. After adding completely, stir at 30 ° C until it is completely dissolved, centrifuge, remove the upper liquid, and wash the precipitate repeatedly with deionized water by centrifugation until the pH is 7.0. The washed viscous precipitate is added to 50 mL of deionized water and ultrasonically treated in a nitrogen atmosphere for 3 hours. The obtained colloidal solution is centrifuged at 3000 rpm for 0.5 hours. The upper colloidal solution is filtered into a thin film using a vacuum circulating water filter and dried. Transition metal carbide nanosheets have a large specific surface area and can provide more adsorption sites. Their surface is rich in functional groups such as hydroxyl and oxygen groups, which can form hydrogen bonds or electrostatic interactions with oils and suspended matter to enhance the adsorption effect. Therefore, oil droplets and suspended matter can be effectively removed by physical and chemical adsorption to obtain transition metal carbide nanosheets.

[0051] (3) Dissolve polyethylene glycol in 100 mL of deionized water. The amount of polyethylene glycol added is 1.0 g. Polyethylene glycol effectively removes oil and suspended solids in oilfield wastewater treatment through flocculation, demulsification and solubilization, and has the characteristics of high efficiency, environmental protection and economy. Then add the transition metal carbide nanosheets described in step (2) and ultrasonically treat for 20 minutes. Then add the UIO nanoparticles described in step (1), first stir at 100 rpm for 0.5 hours, then ultrasonically disperse for 1 hour, centrifuge, and dry the precipitate. The UIO nanoparticles and transition metal carbide nanosheets are self-assembled and connected through the hydrogen bonding effect of polyethylene glycol to form a stable intercalated structure, which has excellent anti-swelling performance in oilfield wastewater. Among them, the insertion of UIO nanoparticles effectively increases the interlayer spacing between the transition metal carbide nanosheets, which not only reduces the aggregation of the transition metal carbide nanosheets, but also increases the permeation flux and the adsorption amount of oil and suspended solids, thereby improving the purification efficiency and obtaining a composite synergistic factor.

[0052] This embodiment provides a method for preparing a high-efficiency water purifier for treating oilfield wastewater, which specifically includes the following steps:

[0053] S1. The raw banana fiber was crushed and the crushed fiber was taken out and passed through a 60-mesh sieve. The banana fiber powder was washed with distilled water and dried in an oven at 80°C. 8.0 g of the dried powder was weighed and placed in a Soxhlet extractor. 100 mL of a mixed solution of benzene and ethanol was added, wherein the volume ratio of benzene to ethanol was 1:1. The mixture was extracted at 80°C for 5 h and then taken out. The extraction process can remove wax and pectin in the banana fiber. The extracted banana fiber was placed in a sodium chlorite solution with a mass fraction of 10% and a pH of 3.0, and bleached at 70°C for 0.5 h. This process was repeated 4 times, then washed with distilled water and dried. The bleaching process can remove lignin in the fiber through oxidation. The bleached banana fiber was then The fiber was added to a 5% by mass potassium hydroxide solution and degummed at 90°C for 1 hour to fully remove hemicellulose. The fiber was then washed and dried, and the degummed banana cellulose was then added to 50 mL of distilled water, fully stirred, and nano-processed using an ultrasonic cell crusher with an ultrasonic power of 1000 W and an ultrasonic time of 20 minutes. The fiber was then freeze-dried. This process effectively removed the adverse effects of pectin, lignin, and hemicellulose, producing nano-scale banana cellulose with a large specific surface area, which can provide more adsorption sites and is easier to surface modify, thereby enhancing the adsorption capacity for various types of oils and suspended matter, resulting in banana nanocellulose.

[0054] S2, dispersing the banana nanocellulose described in step S1 in 100 mL of distilled water, adjusting the pH to 3.0, ultrasonically dispersing for 20 min, adding methyltrimethoxysilane for reaction for 1 h, the amount of methyltrimethoxysilane added is 1.0 g, the siloxane layer formed by methyltrimethoxysilane protects the banana nanocellulose from chemical corrosion and improves its stability in oilfield wastewater, transferring to a 70° C. oven for crosslinking for 1 h, the introduction of alkyl chains improves the hydrophobicity of the banana nanocellulose aerogel and increases its affinity for oil and fat, thereby improving the adsorption efficiency and purification effect, thereby obtaining an alkyl-modified banana nanocellulose aerogel;

[0055] S3, 8.6g of succinic anhydride and 20.2mL of 3-aminopropyltriethoxysilane were dissolved in 60mL of N,N-dimethylformamide, and magnetically stirred at 40°C for 2h, followed by adding 2mL of deionized water and continuing to stir for 1h to obtain a carboxyl-modified solution, and the alkyl-modified banana nanocellulose aerogel described in step S2 was immersed in the carboxyl-modified solution and cured for 5h. The introduction of carboxyl groups increased the hydrophilicity of the aerogel, and the charge interaction between the carboxyl groups and the surface of the suspended particles enhanced the adsorption capacity of the aerogel for suspended particles. Then, freeze-dried, alkyl modification and carboxyl modification respectively enhanced the adsorption capacity of the banana nanocellulose aerogel for grease and suspended particles, so that it can efficiently remove two types of pollutants at the same time, and endowed the aerogel with hydrophilic and lipophilic amphiphilicity, showing excellent wettability, and can fully contact with grease and suspended matter in oilfield wastewater, which helps to quickly penetrate and adsorb pollutants, improve the reaction rate and purification effect, and obtain a wettable aerogel carrier material;

[0056] S4. Inoculate 1.0 g of diesel-eating alkanes into a blue-mouthed bottle filled with 2216E culture medium and the wettable aerogel carrier material described in step S3 and culture for 36 hours. The product number of diesel-eating alkanes is BNCC186183. Diesel-eating alkanes is a bacterium that feeds on hydrocarbons and can degrade petroleum hydrocarbons, including diesel and crude oil. It can also aggregate suspended matter in water through biological flocculation. The high porosity of the wettable aerogel carrier material provides an ideal habitat for diesel-eating alkanes. Its thermal insulation properties also help maintain a suitable temperature for the growth and reproduction of diesel-eating alkanes, avoid the adverse effects of the external environment, and better protect the activity of the bacteria. Filter and remove the supernatant. Place the wettable aerogel carrier material containing diesel-eating alkanes into a fermentation tank, add 2216E culture medium to 80% of the tank volume, and culture at 37°C for 7 days, replacing the tank every 1 day. The 2216E culture medium in the culture medium was used. After the cultivation was completed, the supernatant was discarded, freeze-dried, and finally mixed with the composite synergistic factor at a mixing speed of 1000 rpm and a mixing time of 1 hour. At this time, the content of diesel-eating bacteria was 13LogCFU / g. The wettable aerogel carrier material and diesel-eating bacteria were co-fermented and cultured, so that diesel-eating bacteria formed a biofilm on the wettable aerogel carrier material. Not only was the purification ability of the wettable aerogel carrier material for grease and suspended matter enhanced, but the degradation effect of diesel-eating bacteria was also effectively improved. In addition, the addition of the composite synergistic factor enhanced the environmental tolerance of diesel-eating bacteria and further increased the roughness of the wettable aerogel carrier material, providing more adsorption sites, which was conducive to better exerting the adsorption and decomposition effects of each component on grease and suspended matter, improving the purification effect, and obtaining a high-efficiency water purifier for treating oilfield wastewater.

[0057] Example 3

[0058] This embodiment provides a high-efficiency water purifier for treating oilfield wastewater, comprising the following components in parts by weight: 55 parts of a composite synergistic factor, 25 parts of a wettable aerogel carrier material, and 1.5 parts of diesel-eating bacteria.

[0059] The composite synergistic factor comprises the following components in parts by weight: 4 parts of UIO nanoparticles, 15 parts of polyethylene glycol, and 4 parts of transition metal carbide nanosheets.

[0060] The wettable aerogel carrier material comprises the following components in parts by weight: 15 parts of banana nanocellulose, 15 parts of methyltrimethoxysilane, and 6.5 parts of carboxyl modification liquid.

[0061] The preparation method of the composite synergistic factor specifically comprises the following steps:

[0062] (1) Dissolve zirconium chloride in a mixed solution of 0.6 mL of 37% hydrochloric acid solution and 5 mL of N,N-dimethylformamide. The amount of zirconium chloride added is 0.15 g. Metal ion zirconium can decompose organic pollutants through chemical catalysis and improve degradation efficiency. Ultrasonic treatment is carried out for 25 minutes to prepare solution I. Then, 0.15 g of 2-aminoterephthalic acid is added to a mixed solution of 5 mL of acetic acid and 10 mL of N,N-dimethylformamide, and heated in an oil bath at 70°C for 25 minutes to prepare solution II. Then, solution I and solution II are mixed and stirred at 110°C for 1.5 hours. The precipitate is collected, washed with N,N-dimethylformamide and anhydrous ethanol solution in sequence, and dried. The three-dimensional porous framework material UIO-66-NH2 with an octahedral structure is constructed by combining the central metal ion Zr and the organic complex 2-aminoterephthalic acid through coordination. Its high specific surface area and pore structure can physically adsorb grease and suspended matter in oilfield wastewater. The amino groups on the surface of UIO-66-NH2 enhance its hydrophilicity and chemical activity, making it easier to combine with grease and suspended matter, thereby enhancing its adsorption performance. At the same time, the organic framework of MOF still has a certain degree of hydrophobicity, which also helps to adsorb hydrophobic grease. In addition, UIO-66-NH2 shows good stability under acid, alkali and high temperature conditions, making it suitable for complex oilfield wastewater environments, and thus obtaining UIO nanoparticles.

[0063] (2) Add 2.5 g of lithium fluoride to 20 mL of 37% hydrochloric acid solution, stir at 70 rpm, and slowly add 1.5 g of titanium aluminum carbide. After adding completely, stir at 35 ° C until it is completely dissolved, centrifuge, remove the upper liquid, and wash the precipitate repeatedly with deionized water by centrifugation until the pH is 7.0. The washed viscous precipitate is added to 50 mL of deionized water and ultrasonically treated in a nitrogen atmosphere for 3.5 h. The obtained colloidal solution is centrifuged at 3500 rpm for 0.75 h. The upper colloidal solution is filtered into a thin film using a vacuum circulating water filter and dried. Transition metal carbide nanosheets have a large specific surface area and can provide more adsorption sites. Their surface is rich in functional groups such as hydroxyl and oxygen groups, which can form hydrogen bonds or electrostatic interactions with oils and suspended matter to enhance the adsorption effect. Therefore, oil droplets and suspended matter can be effectively removed by physical and chemical adsorption to obtain transition metal carbide nanosheets.

[0064] (3) Dissolve polyethylene glycol in 100 mL of deionized water. The amount of polyethylene glycol added is 1.5 g. Polyethylene glycol effectively removes oil and suspended solids in oilfield wastewater treatment through flocculation, demulsification and solubilization, and has the characteristics of high efficiency, environmental protection and economy. Then add the transition metal carbide nanosheets described in step (2) and ultrasonically treat for 25 minutes. Then add the UIO nanoparticles described in step (1). First, stir at a speed of 150 rpm for 0.75 hours, then ultrasonically disperse for 1.5 hours, centrifuge, and dry the precipitate. The UIO nanoparticles and transition metal carbide nanosheets are self-assembled and connected through the hydrogen bonding effect of polyethylene glycol to form a stable intercalated structure, which has excellent anti-swelling performance in oilfield wastewater. Among them, the insertion of UIO nanoparticles effectively increases the interlayer spacing between the transition metal carbide nanosheets, which not only reduces the aggregation of the transition metal carbide nanosheets, but also increases the permeation flux and the adsorption amount of oil and suspended solids, thereby improving the purification efficiency and obtaining a composite synergistic factor.

[0065] This embodiment provides a method for preparing a high-efficiency water purifier for treating oilfield wastewater, which specifically includes the following steps:

[0066] S1. The raw banana fiber was crushed and the crushed fiber was taken out and passed through a 70-mesh sieve. The banana fiber powder was washed with distilled water and dried in an oven at 80°C. 9.0 g of the dried powder was weighed and placed in a Soxhlet extractor. 150 mL of a mixed solution of benzene and ethanol was added, wherein the volume ratio of benzene to ethanol was 1.5:1. The mixture was extracted at 85°C for 5.5 h and then taken out. The extraction process can remove wax and pectin in the banana fiber. The extracted banana fiber was placed in a sodium chlorite solution with a mass fraction of 10% and a pH of 3.0, and bleached at 72.5°C for 0.75 h. This process was repeated 5 times, then washed with distilled water and dried. The bleaching process can remove lignin in the fiber by oxidation. Banana fiber was added to a 5% potassium hydroxide solution and degummed at 92.5°C for 1.5 hours to fully remove hemicellulose. The fiber was then washed and dried, and then the degummed banana cellulose was added to 50 mL of distilled water, stirred thoroughly, and nano-processed using an ultrasonic cell crusher with an ultrasonic power of 1250 W and an ultrasonic time of 25 minutes. The fiber was then freeze-dried. This process effectively removed the adverse effects of pectin, lignin, and hemicellulose, producing nano-scale banana cellulose with a large specific surface area, which can provide more adsorption sites and is easier to surface modify. This enhances the adsorption capacity for various types of oils and suspended matter, resulting in banana nanocellulose.

[0067] S2, dispersing the banana nanocellulose described in step S1 in 100 mL of distilled water, adjusting the pH to 3.0, ultrasonically dispersing for 25 min, adding methyltrimethoxysilane for reaction for 1 h, the amount of methyltrimethoxysilane added is 1.5 g, the siloxane layer formed by methyltrimethoxysilane protects the banana nanocellulose from chemical corrosion and improves its stability in oilfield wastewater, transferring to a 70 ° C oven for crosslinking for 1.5 h, the introduction of alkyl chains improves the hydrophobicity of the banana nanocellulose aerogel and increases its affinity for oil and fat, thereby improving the adsorption efficiency and purification effect, thereby obtaining an alkyl-modified banana nanocellulose aerogel;

[0068] S3, 8.6g succinic anhydride and 20.2mL 3-aminopropyltriethoxysilane were dissolved in 60mL N, N-dimethylformamide, magnetically stirred at 40 ° C for 2.5h, then 2mL deionized water was added and stirred for 1h to obtain a carboxyl-modified solution, and the alkyl-modified banana nanocellulose aerogel described in step S2 was immersed in the carboxyl-modified solution and cured for 5.5h. The introduction of carboxyl groups increased the hydrophilicity of the aerogel, and the charge interaction between the carboxyl groups and the surface of the suspended particles enhanced the adsorption capacity of the aerogel for suspended particles. Then, freeze-dried, alkyl modification and carboxyl modification respectively enhanced the adsorption capacity of the banana nanocellulose aerogel for grease and suspended particles, so that it can efficiently remove two types of pollutants at the same time, and endowed the aerogel with hydrophilic and lipophilic amphiphilicity, showing excellent wettability, and can fully contact with grease and suspended matter in oilfield wastewater, which helps to quickly penetrate and adsorb pollutants, improve the reaction rate and purification effect, and obtain a wettable aerogel carrier material;

[0069] S4. Inoculate 1.5 g of diesel-eating alkanes in a blue-mouthed bottle filled with 2216E culture medium and the wettable aerogel carrier material described in step S3 and culture for 36 hours. The product number of diesel-eating alkanes is BNCC186183. Diesel-eating alkanes is a bacterium that feeds on hydrocarbons and can degrade petroleum hydrocarbons, including diesel and crude oil. It can also aggregate suspended matter in water through biological flocculation. The high porosity of the wettable aerogel carrier material provides an ideal habitat for diesel-eating alkanes, and its heat-insulating and heat-preserving properties also help maintain a suitable temperature for the growth and reproduction of diesel-eating alkanes, avoid the adverse effects of the external environment, and better protect the activity of the bacteria. Filter and remove the supernatant. Place the wettable aerogel carrier material containing diesel-eating alkanes in a fermentation tank, add 2216E culture medium to 80% of the tank volume, and culture at 37°C for 7 days. Replace the aerogel carrier material in the tank every 1 day. 2216E culture medium was used. After the culture was completed, the supernatant was discarded, freeze-dried, and finally mixed with the composite synergistic factor at a mixing speed of 1500rpm and a mixing time of 1.5h. At this time, the content of diesel-eating bacteria was 14LogCFU / g. The wettable aerogel carrier material and diesel-eating bacteria were co-fermented and cultured, so that diesel-eating bacteria formed a biofilm on the wettable aerogel carrier material. Not only was the purification ability of the wettable aerogel carrier material for grease and suspended matter enhanced, but the degradation effect of diesel-eating bacteria was also effectively improved. In addition, the addition of the composite synergistic factor enhanced the environmental tolerance of diesel-eating bacteria and further increased the roughness of the wettable aerogel carrier material, providing more adsorption sites, which was conducive to better exerting the adsorption and decomposition effects of each component on grease and suspended matter, improving the purification effect, and obtaining a high-efficiency water purifier for treating oilfield wastewater.

[0070] Example 4

[0071] This embodiment provides a high-efficiency water purifier for treating oilfield wastewater, comprising the following components in parts by weight: 60 parts of a composite synergistic factor, 20 parts of a wettable aerogel carrier material, and 1 part of diesel-eating bacteria.

[0072] The composite synergistic factor comprises the following components in parts by weight: 5 parts of UIO nanoparticles, 10 parts of polyethylene glycol, and 5 parts of transition metal carbide nanosheets.

[0073] The wettable aerogel carrier material comprises the following components in parts by weight: 20 parts of banana nanocellulose, 10 parts of methyltrimethoxysilane, and 5 parts of carboxyl modification liquid.

[0074] The preparation method of the composite synergistic factor specifically comprises the following steps:

[0075] (1) Dissolve zirconium chloride in a mixed solution of 0.6 mL of 37% hydrochloric acid solution and 5 mL of N, N-dimethylformamide. The amount of zirconium chloride added is 0.2 g. Metal ion zirconium can decompose organic pollutants by chemical catalysis and improve degradation efficiency. Ultrasonic treatment is performed for 20 min to prepare solution I. Then, 0.1 g of 2-aminoterephthalic acid is added to a mixed solution of 5 mL of acetic acid and 10 mL of N, N-dimethylformamide. Heat the mixture in an oil bath at 80 °C for 20 min to prepare solution II. Then, solution I and solution II are mixed and stirred at 120 °C for 1 h. The precipitate is collected and washed with N, N-dimethylformamide and anhydrous ethanol solution in sequence, and dried. The central metal ion Zr and the organic complex 2-aminoterephthalic acid are combined through coordination to form a three-dimensional porous framework material UIO-66-NH2 with an octahedral structure. Its high specific surface area and pore structure can physically adsorb grease and suspended matter in oilfield wastewater. The amino groups on the surface of UIO-66-NH2 enhance its hydrophilicity and chemical activity, making it easier to bind with grease and suspended matter, thereby enhancing its adsorption performance. At the same time, the organic framework of MOF still has a certain degree of hydrophobicity, which also helps to adsorb hydrophobic grease. In addition, UIO-66-NH2 shows good stability under acid, alkali and high temperature conditions, making it suitable for complex oilfield wastewater environments, and thus obtaining UIO nanoparticles.

[0076] (2) Add 3.0 g of lithium fluoride to 20 mL of 37% hydrochloric acid solution, stir at 80 rpm, and slowly add 2.0 g of titanium aluminum carbide. After adding completely, stir at 40 ° C until it is completely dissolved, centrifuge, remove the upper liquid, and wash the precipitate repeatedly with deionized water by centrifugation until the pH is 7.0. The washed viscous precipitate is added to 50 mL of deionized water and ultrasonically treated in a nitrogen atmosphere for 3 hours. The obtained colloidal solution is centrifuged at 4000 rpm for 0.5 hours. The upper colloidal solution is filtered into a thin film using a vacuum circulating water filter and dried. Transition metal carbide nanosheets have a large specific surface area and can provide more adsorption sites. Their surface is rich in functional groups such as hydroxyl and oxygen groups, which can form hydrogen bonds or electrostatic interactions with oils and suspended matter to enhance the adsorption effect. Therefore, oil droplets and suspended matter can be effectively removed by physical and chemical adsorption to obtain transition metal carbide nanosheets.

[0077] (3) Dissolve polyethylene glycol in 100 mL of deionized water. The amount of polyethylene glycol added is 1.0 g. Polyethylene glycol effectively removes oil and suspended solids in oilfield wastewater treatment through flocculation, demulsification and solubilization, and has the characteristics of high efficiency, environmental protection and economy. Then add the transition metal carbide nanosheets described in step (2) and ultrasonically treat for 20 minutes. Then add the UIO nanoparticles described in step (1). First, stir at 200 rpm for 0.5 hours, then ultrasonically disperse for 1 hour, centrifuge, and dry the precipitate. The UIO nanoparticles and transition metal carbide nanosheets are self-assembled and connected through the hydrogen bonding effect of polyethylene glycol to form a stable intercalated structure, which has excellent anti-swelling performance in oilfield wastewater. Among them, the insertion of UIO nanoparticles effectively increases the interlayer spacing between the transition metal carbide nanosheets, which not only reduces the aggregation of the transition metal carbide nanosheets, but also increases the permeation flux and the adsorption of oil and suspended solids, thereby improving the purification efficiency and obtaining a composite synergistic factor.

[0078] This embodiment provides a method for preparing a high-efficiency water purifier for treating oilfield wastewater, which specifically includes the following steps:

[0079] S1. The raw banana fiber was crushed and the crushed fiber was taken out and passed through an 80-mesh sieve. The banana fiber powder was washed with distilled water and dried in an oven at 80°C. 10.0 g of the dried powder was weighed and placed in a Soxhlet extractor. 200 mL of a mixed solution of benzene and ethanol was added, wherein the volume ratio of benzene to ethanol was 2:1. The mixture was extracted at 90°C for 5 h and then taken out. The extraction process can remove wax and pectin in the banana fiber. The extracted banana fiber was placed in a sodium chlorite solution with a mass fraction of 10% and a pH of 3.0, and bleached at 75°C for 0.5 h. This process was repeated 6 times, then washed with distilled water and dried. The bleaching process can remove lignin in the fiber through oxidation. The bleached banana fiber was then The fiber was added to a 5% by mass potassium hydroxide solution and degummed at 95°C for 1 hour to fully remove hemicellulose. The fiber was then washed and dried, and the degummed banana cellulose was added to 50 mL of distilled water, fully stirred, and nano-processed using an ultrasonic cell crusher with an ultrasonic power of 1500 W and an ultrasonic time of 20 minutes. The fiber was then freeze-dried. This process effectively removed the adverse effects of pectin, lignin, and hemicellulose, producing nano-scale banana cellulose with a large specific surface area, which can provide more adsorption sites and is easier to surface modify, thereby enhancing the adsorption capacity for various types of oils and suspended matter, resulting in banana nanocellulose.

[0080] S2, dispersing the banana nanocellulose described in step S1 in 100 mL of distilled water, adjusting the pH to 3.0, ultrasonically dispersing for 20 min, adding methyltrimethoxysilane for reaction for 1 h, the amount of methyltrimethoxysilane added is 1.0 g, the siloxane layer formed by methyltrimethoxysilane protects the banana nanocellulose from chemical corrosion and improves its stability in oilfield wastewater, transferring to a 70° C. oven for crosslinking for 1 h, the introduction of alkyl chains improves the hydrophobicity of the banana nanocellulose aerogel and increases its affinity for oil and fat, thereby improving the adsorption efficiency and purification effect, thereby obtaining an alkyl-modified banana nanocellulose aerogel;

[0081] S3, 8.6g of succinic anhydride and 20.2mL of 3-aminopropyltriethoxysilane were dissolved in 60mL of N,N-dimethylformamide, and magnetically stirred at 40°C for 2h, followed by adding 2mL of deionized water and continuing to stir for 1h to obtain a carboxyl-modified solution, and the alkyl-modified banana nanocellulose aerogel described in step S2 was immersed in the carboxyl-modified solution and cured for 5h. The introduction of carboxyl groups increased the hydrophilicity of the aerogel, and the charge interaction between the carboxyl groups and the surface of the suspended particles enhanced the adsorption capacity of the aerogel for suspended particles. Then, freeze-dried, alkyl modification and carboxyl modification respectively enhanced the adsorption capacity of the banana nanocellulose aerogel for grease and suspended particles, so that it can efficiently remove two types of pollutants at the same time, and endowed the aerogel with hydrophilic and lipophilic amphiphilicity, showing excellent wettability, and can fully contact with grease and suspended matter in oilfield wastewater, which helps to quickly penetrate and adsorb pollutants, improve the reaction rate and purification effect, and obtain a wettable aerogel carrier material;

[0082] S4. Inoculate 1.0 g of diesel-eating alkanes into a blue-mouthed bottle filled with 2216E culture medium and the wettable aerogel carrier material described in step S3 and culture for 36 hours. The product number of diesel-eating alkanes is BNCC186183. Diesel-eating alkanes is a bacterium that feeds on hydrocarbons and can degrade petroleum hydrocarbons, including diesel and crude oil. It can also aggregate suspended matter in water through biological flocculation. The high porosity of the wettable aerogel carrier material provides an ideal habitat for diesel-eating alkanes. Its thermal insulation properties also help maintain a suitable temperature for the growth and reproduction of diesel-eating alkanes, avoid the adverse effects of the external environment, and better protect the activity of the bacteria. Filter and remove the supernatant. Place the wettable aerogel carrier material containing diesel-eating alkanes into a fermentation tank, add 2216E culture medium to 80% of the tank volume, and culture at 37°C for 7 days, replacing the tank every 1 day. The 2216E culture medium in the culture medium was used. After the cultivation was completed, the supernatant was discarded, freeze-dried, and finally mixed with the composite synergistic factor at a mixing speed of 2000 rpm and a mixing time of 1 hour. At this time, the content of diesel-eating bacteria was 13LogCFU / g. The wettable aerogel carrier material and diesel-eating bacteria were fermented and cultured together, so that diesel-eating bacteria formed a biofilm on the wettable aerogel carrier material. Not only was the purification ability of the wettable aerogel carrier material for grease and suspended matter enhanced, but the degradation effect of diesel-eating bacteria was also effectively improved. In addition, the addition of the composite synergistic factor enhanced the environmental tolerance of diesel-eating bacteria and further increased the roughness of the wettable aerogel carrier material, providing more adsorption sites, which was conducive to better exerting the adsorption and decomposition effects of each component on grease and suspended matter, improving the purification effect, and obtaining a high-efficiency water purifier for treating oilfield wastewater.

[0083] Comparative Example 1

[0084] This comparative example provides a high-efficiency water purifier for treating oilfield wastewater, which differs from Example 1 in that the composite synergistic factor does not contain UIO nanoparticles and polyethylene glycol; the preparation method of the composite synergistic factor does not include steps (1) and (3); the preparation method of the high-efficiency water purifier for treating oilfield wastewater is the same as that of Example 1.

[0085] Comparative Example 2

[0086] This comparative example provides a high-efficiency water purifier for treating oilfield wastewater, which differs from Example 1 in that the wettable aerogel carrier material does not contain methyltrimethoxysilane or carboxyl-modified liquid; the preparation method of the composite synergistic factor is the same as that of Example 1; and in the preparation method of the high-efficiency water purifier for treating oilfield wastewater, methyltrimethoxysilane is not added in step S2 and the carboxyl-modified liquid is not added in step S3.

[0087] Comparative Example 3

[0088] This comparative example provides a high-efficiency water purifier for treating oilfield wastewater, which differs from Example 1 in that the high-efficiency water purifier for treating oilfield wastewater does not contain diesel-eating bacteria; the preparation method of the composite synergistic factor is the same as that of Example 1; and the preparation method of the high-efficiency water purifier for treating oilfield wastewater does not include step S4.

[0089] Experimental Example 1

[0090] Degreasing experiment

[0091] Test sample: High-efficiency water purifier for treating oilfield wastewater prepared in Examples 1-4 and Comparative Examples 1-3.

[0092] Test method: Select the produced water in Huachi Oilfield Station as the water sample to be tested and add it to a 500mL beaker, where the oil concentration of the wastewater is 500mg / L, the pH is 9.0, and the water temperature is 35±1℃. Add 1.0g of test sample, stir at 160rpm for 8min, and then stir at 80rpm for 8min. After standing for 8h, use a pipette to remove the middle water sample, and measure the oil concentration according to HJ637-2012 "Water quality-Determination of petroleum and animal and plant oils-Infrared spectrophotometry", and calculate the oil removal rate (%) according to the oil concentration before and after treatment.

[0093] Figure 3 The oil removal rate results of Examples 1-4 and Comparative Examples 1-3 are shown in the figure; as shown in the figure, the oil removal rate of Examples 1-4 is 94.5-96.7%, indicating that the oil removal performance is good; the oil removal rate of Comparative Examples 1-3 is 70.6-85.5%, indicating that the oil removal performance is average; the composite synergistic factor of Comparative Example 1 does not contain UIO nanoparticles and polyethylene glycol, and cannot form a stable intercalation structure, which is not conducive to increasing the adsorption of oil and fat, nor is it conducive to enhancing the resistance of the infiltrative aerogel carrier material containing diesel-eating bacteria to external environments such as alkali and high temperature, thereby reducing its oil purification function and resulting in poor oil removal performance. General; the wettable aerogel carrier material of comparative example 2 does not contain methyltrimethoxysilane and carboxyl modification liquid, and cannot impart excellent wettability through double modification, which is not conducive to full contact with grease, nor can it enhance the adsorption capacity of grease, and is also not conducive to the growth and reproduction of bacteria, and also limits the oil removal effect of bacteria, resulting in general oil removal performance; the high-efficiency water purifier for treating oilfield wastewater of comparative example 3 does not contain diesel-eating bacteria, and can neither exert the purification effect of bacteria nor enhance the purification ability of chemical materials for grease. It only relies on the chemical material itself to remove grease, resulting in general oil removal performance.

[0094] Experimental Example 2

[0095] Desuspended matter experiment

[0096] Test sample: High-efficiency water purifier for treating oilfield wastewater prepared in Examples 1-4 and Comparative Examples 1-3.

[0097] Test method: Select the produced water from Huachi Oilfield Station as the water sample to be tested and add it to a 500mL beaker, where the suspended solids concentration of the sewage is 300mg / L, the pH is 9.0, and the water temperature is 35±1℃. Add 1.0g of test sample, stir at 160rpm for 8min, and then stir at 80rpm for 8min. After standing for 8h, use a pipette to remove the middle water sample, and refer to GB11901-89 "Water Quality - Determination of Suspended Solids - Gravimetric Method" to determine the suspended solids concentration, and calculate the suspended solids removal rate (%) based on the suspended solids concentrations before and after treatment.

[0098] Figure 4 The results of suspended solids removal rates of Examples 1-4 and Comparative Examples 1-3 are shown in the figure. As shown in the figure, the suspended solids removal rates of Examples 1-4 are 92.0-93.6%, indicating that the suspended solids removal is strong; the suspended solids removal rates of Comparative Examples 1-3 are 68.8-82.2%, indicating that the suspended solids removal is weak; the composite synergistic factor of Comparative Example 1 does not contain UIO nanoparticles and polyethylene glycol, and cannot form a stable intercalation structure through self-assembly connection, which is not conducive to increasing the adsorption of suspended solids, and cannot resist the erosion of alkali and salts in oilfield wastewater and the influence of high temperature, which is not conducive to maintaining the activity of the bacteria and limits the purification of suspended solids. efficacy, resulting in weak suspended matter removal performance; the wettable aerogel carrier material of Comparative Example 2 does not contain methyltrimethoxysilane and carboxyl modified liquid, and cannot achieve excellent wettability, which is not conducive to the reproduction and activity maintenance of the bacteria, nor is it conducive to sufficient contact with the suspended matter, so that the adsorption and purification effects of microorganisms and chemical materials on the suspended matter are weakened, resulting in weak suspended matter removal performance; the high-efficiency water purifier for treating oilfield wastewater of Comparative Example 3 does not contain diesel-eating bacteria, and cannot purify the suspended matter by combining microorganisms and chemical materials, nor can it optimize the adsorption function of a single component, resulting in weak suspended matter removal performance.

[0099] The above experimental results show that the oil removal and suspended matter removal effects of Examples 1-4 of the present invention are significantly better than those of the samples of Comparative Examples 1-3. Among them, Example 1 using a composite synergistic factor and a wettable aerogel carrier material has better oil removal performance and stronger suspended matter removal. The diesel-eating bacteria and the wettable aerogel carrier material are co-fermented and cultured to form a biofilm on the wettable aerogel carrier material. Under the action of the composite synergistic factor, the environmental tolerance stability of the diesel-eating bacteria and the wettable aerogel carrier material is further enhanced, and more adsorption sites are provided. The three work synergistically, and the adsorption function of a single component is fully optimized in a combination of microorganisms and chemical materials, thereby significantly improving the purification treatment effect of oilfield wastewater.

[0100] While the embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions, and alterations can be made to the embodiments without departing from the principles and spirit of the invention.

[0101] The present invention and its embodiments are described above. Such description is not restrictive. The drawings show only one embodiment of the present invention, and actual applications are not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the present invention, any method and embodiment similar to the technical solution without creative design shall fall within the scope of protection of the present invention.

Claims

1. A high-efficiency water purifier for treating oilfield wastewater, characterized by: The high-efficiency water purifier for treating oilfield wastewater comprises the following components in parts by weight: 50-60 parts of a composite synergistic factor, 20-30 parts of a wettable aerogel carrier material, and 1-2 parts of diesel-eating alkanes; the composite synergistic factor comprises the following components in parts by weight: 3-5 parts of UIO nanoparticles, 10-20 parts of polyethylene glycol, and 3-5 parts of transition metal carbide nanosheets; the wettable aerogel carrier material comprises the following components in parts by weight: 10-20 parts of banana nanocellulose, 10-20 parts of methyltrimethoxysilane, and 5-10 parts of a carboxyl modification liquid; The preparation method of the composite synergistic factor specifically comprises the following steps: (1) Dissolve zirconium chloride in a mixed solution of 0.6 mL of 37% hydrochloric acid solution and 5 mL of N,N-dimethylformamide, and ultrasonically treat for 20-30 min to obtain solution I. Then, add 0.1-0.2 g of 2-aminoterephthalic acid to a mixed solution of 5 mL of acetic acid and 10 mL of N,N-dimethylformamide, and heat in an oil bath at 60-80 ° C for 20-30 min to obtain solution II. Then, mix solution I and solution II, and stir at 100-120 ° C for 1-2 h. Collect the precipitate, wash it with N,N-dimethylformamide and anhydrous ethanol solution in sequence, and dry it to obtain UIO nanoparticles. (2) Add 2.0-3.0 g of lithium fluoride to 20 mL of 37% hydrochloric acid solution, stir at 60-80 rpm, and slowly add 1.0-2.0 g of titanium aluminum carbide. After the addition is complete, stir at 30-40 ° C until it is completely dissolved, centrifuge, remove the upper liquid, and wash the precipitate repeatedly with deionized water by centrifugation until the pH is 7.

0. The washed viscous precipitate is added to 50 mL of deionized water and ultrasonically treated in a nitrogen atmosphere for 3-4 hours. The obtained colloidal solution is centrifuged at 3000-4000 rpm for 0.5-1 hour. The upper colloidal solution is filtered into a thin film using a vacuum circulating water filter and dried to obtain transition metal carbide nanosheets; (3) Dissolve polyethylene glycol in 100 mL of deionized water, add the transition metal carbide nanosheets described in step (2), and ultrasonically treat for 20-30 min. Then add the UIO nanoparticles described in step (1), stir at 100-200 rpm for 0.5-1 h, and then ultrasonically disperse for 1-2 h. Centrifuge and dry the precipitate to obtain a composite synergistic factor. The method for preparing the high-efficiency water purifier for treating oilfield wastewater specifically comprises the following steps: S1. Grind the raw banana fiber, take out the chopped fiber and pass it through a 60-80 mesh sieve. Wash the banana fiber powder with distilled water and dry it in an 80℃ oven. Weigh 8.0-10.0g of the dried powder and place it in a Soxhlet extractor. Add 100-200mL of a mixed solution of benzene and ethanol, wherein the volume ratio of benzene to ethanol is (1-2):

1. Extract at 80-90℃ for 5-6h and then take it out. The extracted banana fiber is placed in a sodium chlorite solution with a mass fraction of 10% and a pH of 3.0 and heated at 70-75℃ for 1h. ℃ bleaching treatment for 0.5-1h, repeating this process 4-6 times, washing with distilled water and drying, then adding the bleached banana fiber into a 5% potassium hydroxide solution by mass, degumming treatment at 90-95℃ for 1-2h, taking out, washing and drying, then adding the degummed banana cellulose into 50mL distilled water, stirring well, using an ultrasonic cell crusher for nano-processing, wherein the ultrasonic power is 1000-1500W, the ultrasonic time is 20-30min, and freeze-drying to obtain banana nanocellulose; S2. Disperse the banana nanocellulose described in step S1 in 100 mL of distilled water, adjust the pH to 3.0, ultrasonically disperse for 20-30 min, add methyltrimethoxysilane and react for 1 h, transfer to a 70° C. oven for crosslinking for 1-2 h to obtain an alkyl-modified banana nanocellulose aerogel; S3, dissolving 8.6 g of succinic anhydride and 20.2 mL of 3-aminopropyltriethoxysilane in 60 mL of N,N-dimethylformamide, magnetically stirring at 40 ° C for 2-3 h, then adding 2 mL of deionized water and continuing to stir for 1 h to obtain a carboxyl-modified liquid, soaking the alkyl-modified banana nanocellulose aerogel described in step S2 in the carboxyl-modified liquid, curing for 5-6 h, and then freeze-drying to obtain an infiltrative aerogel carrier material; S4. Inoculate 1.0-2.0 g of diesel-eating bacteria into a blue-mouthed bottle containing 2216E culture medium and the infiltrative aerogel carrier material described in step S3, and culture for 36 hours. Filter and remove the supernatant. Place the infiltrative aerogel carrier material containing diesel-eating bacteria into a fermentation tank, add 2216E culture medium to reach 80% of the tank volume, and culture at 37°C for 7 days. Replace the 2216E culture medium in the tank every 1 day. After the culture is completed, discard the supernatant, freeze-dry, and finally mix with the composite synergistic factor at a mixing speed of 1000-2000 rpm and a mixing time of 1-2 hours. At this time, the content of diesel-eating bacteria is 13-14 LogCFU / g, and a high-efficiency water purifier for treating oilfield wastewater is obtained.

2. A method for preparing a high-efficiency water purifier for treating oilfield wastewater according to claim 1, characterized in that: The specific steps include: S1. Grind the raw banana fiber, take out the chopped fiber and pass it through a 60-80 mesh sieve. Wash the banana fiber powder with distilled water and dry it in an 80℃ oven. Weigh 8.0-10.0g of the dried powder and place it in a Soxhlet extractor. Add 100-200mL of a mixed solution of benzene and ethanol, wherein the volume ratio of benzene to ethanol is (1-2):

1. Extract at 80-90℃ for 5-6h and then take it out. The extracted banana fiber is placed in a sodium chlorite solution with a mass fraction of 10% and a pH of 3.0 and heated at 70-75℃ for 1h. ℃ bleaching treatment for 0.5-1h, repeating this process 4-6 times, washing with distilled water and drying, then adding the bleached banana fiber into a 5% potassium hydroxide solution by mass, degumming treatment at 90-95℃ for 1-2h, taking out, washing and drying, then adding the degummed banana cellulose into 50mL distilled water, stirring well, using an ultrasonic cell crusher for nano-processing, wherein the ultrasonic power is 1000-1500W, the ultrasonic time is 20-30min, and freeze-drying to obtain banana nanocellulose; S2. Disperse the banana nanocellulose described in step S1 in 100 mL of distilled water, adjust the pH to 3.0, ultrasonically disperse for 20-30 min, add methyltrimethoxysilane and react for 1 h, transfer to a 70° C. oven for crosslinking for 1-2 h to obtain an alkyl-modified banana nanocellulose aerogel; S3, dissolving 8.6 g of succinic anhydride and 20.2 mL of 3-aminopropyltriethoxysilane in 60 mL of N,N-dimethylformamide, magnetically stirring at 40 ° C for 2-3 h, then adding 2 mL of deionized water and continuing to stir for 1 h to obtain a carboxyl-modified liquid, soaking the alkyl-modified banana nanocellulose aerogel described in step S2 in the carboxyl-modified liquid, curing for 5-6 h, and then freeze-drying to obtain an infiltrative aerogel carrier material; S4. Inoculate 1.0-2.0 g of diesel-eating bacteria into a blue-mouthed bottle containing 2216E culture medium and the infiltrative aerogel carrier material described in step S3, and culture for 36 hours. Filter and remove the supernatant. Place the infiltrative aerogel carrier material containing diesel-eating bacteria into a fermentation tank, add 2216E culture medium to reach 80% of the tank volume, and culture at 37°C for 7 days. Replace the 2216E culture medium in the tank every 1 day. After the culture is completed, discard the supernatant, freeze-dry, and finally mix with the composite synergistic factor at a mixing speed of 1000-2000 rpm and a mixing time of 1-2 hours. At this time, the content of diesel-eating bacteria is 13-14 LogCFU / g, and a high-efficiency water purifier for treating oilfield wastewater is obtained.

3. The method for preparing a high-efficiency water purifier for treating oilfield wastewater according to claim 2, wherein: In step S2, the amount of methyltrimethoxysilane added is 1.0-2.0 g.

4. The method for preparing a high-efficiency water purifier for treating oilfield wastewater according to claim 3, wherein: In step S4, the product number of the diesel-eating bacteria is BNCC186183.

5. The method for preparing a high-efficiency water purifier for treating oilfield wastewater according to claim 4, characterized in that: In step (1), the amount of zirconium chloride added is 0.1-0.2 g.

6. The method for preparing a high-efficiency water purifier for treating oilfield wastewater according to claim 5, characterized in that: In step (3), the amount of polyethylene glycol added is 1.0-2.0 g.

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