Oily sewage adsorbent as well as preparation method and application thereof

Abstract

The invention discloses an oily sewage adsorbent as well as a preparation method and application thereof. The preparation method of the oily sewage adsorbent comprises the following steps: (1) heating and melting inorganic hydrated salt and a nucleating agent to obtain a phase change core material; (2) under the protection of inert carrier gas, a furan compound and a sulfone solvent are subjected to a heating reaction by adding isocyanate and a catalyst, and a monomer is obtained; (3) dissolving primorphin and an alcohol substance in a sulfone solvent, mixing with the monomer in the step (2), and heating for reaction to obtain a film prepolymer; and (4) mixing the film prepolymer obtained in the step (3) with the phase change core material in the step (1), a surfactant and water, carrying out a first dynamic heating reaction, and then carrying out a second dynamic heating reaction to obtain the oily sewage adsorbent. The oily sewage adsorbent obtained by the preparation method provided by the invention has the advantages of moderate density, adjustable temperature, abundant adsorption active sites, long cycle service life and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of oily sewage treatment, and particularly relates to an adsorbent for oily sewage, a preparation method thereof, and an application thereof. Background Art

[0002] Oils and oil-like organic solvents enter the water environment through different channels to form oily sewage. Oily sewage is a kind of sewage with a large quantity, wide distribution and serious harm. Every year, about 5 million to 10 million tons of oil enter the water body through various channels in the world. Water body oil pollution means that after oil substances enter rivers, lakes or groundwater, their content exceeds the self-purification capacity of the water body, causing changes in the physical, chemical properties or biological community composition of the water quality and bottom sediment, thereby reducing the use value and use function of the water body. In addition, the floating oil on the water surface can also extract chlorohydrocarbons dispersed in the water body, such as pesticides like dieldrin and toxaphene, and polychlorinated biphenyls, etc., and enrich these poisons to the surface layer of the water body to poison aquatic organisms.

[0003] Commonly used oily sewage treatment methods include incineration method, oxidation method, filtration method, adsorption method, chemical dispersion method, photocatalysis method, biodegradation method, etc. Among these methods, the adsorption method has received key attention due to its simple operation, strong repeatability, rich functionality and high efficiency.

[0004] CN112221476A discloses a mussel biomimetic modified polyurethane sponge multifunctional adsorbent, which is composed of a polyurethane sponge and dopamine, double-bond dopamine and a polymer monomer hydrophobic olefin coated on the surface of the polyurethane sponge. The modified polyurethane sponge is immersed in a solution of the functional monomer hydrophobic olefin, where the mass fraction of the hydrophobic olefin is 10% - 25%, and an in-situ polymerization reaction is carried out at 60°C - 80°C for 6h - 12h. Subsequently, the residues on the surface of the sponge are removed to obtain a hydrophobic / lipophilic multifunctional polyurethane sponge adsorbent. This adsorbent can be used for the rapid adsorption of organic solvents, industrial wax oil and crude oil. However, after being modified by the hydrophobic olefin, the density of this adsorbent is much lower than the density of water, that is, the adsorbent floats on the water surface. In actual situations, the densities of various petroleum products including crude oil and heavy diesel are close to or even exceed the density of water. Therefore, this adsorbent only has an obvious adsorption effect on the oils floating on the water surface, and has a poor adsorption effect on the heavy oils suspended in the water. In addition, this adsorbent does not have a self-regulating temperature function, that is, its universality is poor in tropical waters and cold waters. At the same time, by means of polydopamine, the sponge is connected with the hydrophobic olefin in a coating manner, and its long-term use stability is limited.

[0005] CN116059971A proposes a preparation method and application of a covalent organic framework-based oleophilic and hydrophobic composite material. The composite material is as follows: first, melamine foam, 1,3,5-tris(4-aminophenyl)benzene (Tab), 2,5-dihydroxyterephthalaldehyde (Db) and a catalyst are reacted to generate Foam@COF-1, and then Foam@COF-1 and heptadecafluorodecyltrimethoxysilane are reacted to obtain a covalent organic framework composite material Foam@COF-2. The obtained covalent organic framework composite material has oleophilicity, hydrophobicity and a wide pH value application range. However, after Foam@COF-1 was immersed in heptadecafluorodecyltrimethoxysilane, the active components of COF-1 were easily shielded by the silane components, that is, the oil absorption capacity of Foam@COF-2 was reduced. In addition, the density of the adsorbent material is much lower than the density of water, that is, it floats on the water surface, so the adsorbent material only has an obvious adsorption effect on oil products floating on the water surface, but has a poor adsorption effect on heavy oil products suspended in water. Summary of the invention

[0006] In order to overcome the shortcomings of the prior art, the present invention provides an oily wastewater adsorbent and a preparation method and application thereof. The oily wastewater adsorbent obtained by the preparation method provided by the present invention has the advantages of moderate density, adjustable temperature, rich adsorption active sites and long cycle life.

[0007] The first aspect of the present invention provides a method for preparing an oily wastewater adsorbent, comprising the following steps:

[0008] (1) Inorganic hydrated salt and nucleating agent are heated and melted to obtain a phase change core material;

[0009] (2) Under the protection of an inert carrier gas, the furan compound is heated with a sulfone solvent, an isocyanate and a catalyst to obtain a monomer;

[0010] (3) dissolving the peptide and alcohol substance in a sulfone solvent, mixing with the monomer of step (2), heating and reacting to obtain a film prepolymer;

[0011] (4) The film prepolymer obtained in step (3) is mixed with the phase change core material, surfactant and water in step (1) to perform a first dynamic heating reaction, and then a second dynamic heating reaction is performed to obtain an oily wastewater adsorbent.

[0012] Furthermore, in step (1), the inorganic hydrated salt is selected from any one or more of disodium hydrogen phosphate dodecahydrate, calcium chloride hexahydrate and sodium sulfate decahydrate.

[0013] Furthermore, in step (1), the nucleating agent is selected from one or more of ammonium nitrate, ammonium acetate and N-nitrosophenylamine, preferably ammonium acetate.

[0014] Further, in step (1), the mass ratio of the inorganic hydrated salt to the nucleating agent is 1:(0.007 - 0.1), preferably 1:(0.03 - 0.08).

[0015] Further, in step (1), the temperature of the heating and melting reaction is 140°C - 180°C, the stirring speed is 500 rpm - 800 rpm, and the time is 30 min - 60 min.

[0016] Further, in step (2), the furan compound is selected from one or more of polytetrahydrofuran, 3 - acetyl - 2,5 - dimethylfuran, and 2,5 - dimethoxydihydrofuran, preferably polytetrahydrofuran; wherein the molecular weight of polytetrahydrofuran is 600 - 1000. The purity of the furan compound generally exceeds 99 wt% before dehydration, but still contains a small amount of water. In the present invention, vacuum dehydration is preferably carried out first, and then the reaction of step (2) is carried out. Preferably, the temperature of the vacuum dehydration is 80°C - 130°C, the time is 30 min - 60 min, and the vacuum degree is 25 kPa - 50 kPa.

[0017] Further, in step (2), the inert gas is selected from any one or more of high - purity nitrogen, high - purity argon, and high - purity helium.

[0018] Further, in step (2), the sulfone solvent is selected from one or more of dimethyl sulfoxide, polyethersulfone, and 2 - methylsulfonylethanol, preferably polyethersulfone; wherein the molecular weight of polyethersulfone is 2300 - 3700.

[0019] Further, in step (2), the isocyanate is selected from one or more of toluene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and lysine diisocyanate, preferably isophorone diisocyanate.

[0020] Further, in step (2), the catalyst is selected from one or more of zinc isooctanoate, stannous octoate, and calcium isooctanoate, preferably zinc isooctanoate.

[0021] Further, in step (2), the mass ratio of the furan compound, sulfone solvent, isocyanate, and catalyst is 1:(0.3 - 2):(0.13 - 0.68):(0.001 - 0.02), preferably 1:(0.75 - 1.24):(0.19 - 0.37):(0.004 - 0.013).

[0022] Further, in step (2), the temperature of the heating reaction is 45°C - 126°C, preferably 60°C - 100°C, the time is 0.5 h - 8 h, preferably 2.5 h - 6 h.

[0023] Further, in step (3), the endorphin is selected from one or more of α-endorphin, β-endorphin, γ-endorphin, dynorphin A, and dynorphin B, preferably γ-endorphin.

[0024] Further, in step (3), the alcohol is selected from one or more of 1,3-propanediol, isopropanol, and 1,6-hexanediol, preferably 1,6-hexanediol.

[0025] Further, in step (3), the sulfone solvent is selected from one or more of dimethyl sulfoxide, polyethersulfone, and 2-methylsulfonylethanol, preferably polyethersulfone, wherein the molecular weight of the polyethersulfone is 2300 - 3700.

[0026] Further, in step (3), the mass ratio of the endorphin, alcohol, sulfone solvent, and monomer is 1:(0.05 - 1.02):(4 - 17):(0.28 - 1.19), preferably 1:(0.29 - 0.68):(7 - 13):(0.41 - 0.96).

[0027] Further, in step (3), the heating reaction is a heating and stirring reaction, wherein the temperature is 30°C - 100°C, preferably 50°C - 80°C, the rotation speed is 600 rpm - 900 rpm, and the time is 15 min - 80 min, preferably 30 min - 50 min.

[0028] Further, in step (4), the surfactant is selected from a combination of a non-ionic surfactant (such as at least one of octylphenol polyoxyethylene ether - 10 and octylphenol polyoxyethylene ether - 15) and an anionic surfactant (such as at least one of sodium dodecyl sulfate and sodium dodecylbenzenesulfonate), preferably a combination of octylphenol polyoxyethylene ether - 10 and sodium dodecyl sulfate; wherein, the mass ratio of the non-ionic surfactant to the anionic surfactant is (0.5 - 3.5):1.

[0029] Further, in step (4), the water is deionized water.

[0030] Further, in step (4), the mass ratio of the thin film prepolymer, phase change core material, surfactant, and water is 1:(0.1 - 1.3):(0.01 - 0.08):(1 - 8), preferably 1:(0.3 - 0.8):(0.024 - 0.057):(1.5 - 4.6).

[0031] Further, in step (4), the conditions for the first dynamic heating are that the reaction temperature is 80°C to 150°C, preferably 105°C to 135°C, the rotation speed is 3000 rpm to 9000 rpm, preferably 5000 rpm to 7000 rpm, and the time is 1.5 min to 12 min, preferably 3 min to 7 min.

[0032] Further, in step (4), the conditions for the second dynamic heating reaction are that the reaction temperature is 80°C to 150°C, preferably 105°C to 135°C, the rotation speed is increased to 200 rpm to 1000 rpm, preferably 400 rpm to 600 rpm, and the reaction time is 1 h to 10 h, preferably 3 h to 7 h.

[0033] Further, before obtaining the oil-containing sewage adsorbent in step (4), it can be subjected to conventional centrifugation, rinsing, and drying in the art; wherein, the rotation speed for the centrifugation treatment is 7000 rpm to 10000 rpm, and the rinsing solvent is selected from any one or more of anhydrous methanol, acetone, and acetonitrile; the drying is preferably vacuum drying, the temperature is 40°C to 135°C, preferably 60°C to 90°C, and the time is 3 h to 15 h, preferably 6 h to 9 h.

[0034] The second aspect of the present invention provides an oil-containing sewage adsorbent obtained by the above preparation method.

[0035] Further, the pore system of the oil-containing sewage adsorbent is a three-dimensional network structure, and at the same time has three pore sizes of micropores, mesopores, and macropores. The micropore ratio is 10% to 20%, the mesopore ratio is 25% to 45%, and the macropore ratio is 40% to 60%.

[0036] Further, the density of the oil-containing sewage adsorbent is 0.87 g / cm 3 ~0.95 g / cm 3 , the water contact angle is 165° to 178°, the phase change temperature is 43.7°C to 58.9°C, the latent heat of fusion phase change value is 146 J / g to 173 J / g, the compressive strength is 3.5 MPa to 5.1 MPa, and the flexural strength is 4.6 MPa to 6.5 MPa.

[0037] Further, the pore system of the oil-containing sewage adsorbent after 20 consecutive adsorption-regeneration cycles is still a three-dimensional network structure, having three pore sizes of micropores, mesopores, and macropores. Among them, the pore structure basically does not change after 20 consecutive adsorption-regeneration cycles. Among them, the change in the micropore ratio compared to the fresh adsorbent before regeneration does not exceed 20%, the change in the mesopore ratio compared to the fresh adsorbent before regeneration does not exceed 12%, and the change in the macropore ratio compared to the fresh adsorbent before regeneration does not exceed 17%.

[0038] Further, after the oil-containing sewage adsorbent is continuously adsorbed and regenerated 20 times, the change in density compared to the fresh adsorbent before regeneration does not exceed 1.5%, the change in water contact angle compared to before regeneration does not exceed 1.2%, the change in the latent heat value of melting phase change compared to the fresh adsorbent before regeneration does not exceed 3%, the change in compressive strength compared to the fresh adsorbent before regeneration does not exceed 2%, and the change in flexural strength compared to the fresh adsorbent before regeneration does not exceed 5%.

[0039] The third aspect of the present invention provides an oil-containing sewage adsorbent obtained by the above preparation method for the technical field of purifying water bodies through the adsorption reaction of oil-containing sewage.

[0040] Further, the oil-containing sewage is preferably the conventional sewage in the art, such as at least one of crude oil sewage, gutter oil sewage, edible oil sewage, and diesel oil sewage.

[0041] Further, the dosage ratio of the oil-containing sewage to the adsorbent is (0.5 mL - 5 mL) of oil-containing sewage: 1 mg of adsorbent.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] (1) The oil-containing sewage adsorbent prepared by the present invention uses inorganic hydrated salts and nucleating agents as raw materials to prepare a phase change core material. On the one hand, the nucleating agent, as a nucleating component, effectively reduces the supercooling degree of the inorganic hydrated salt and promotes its solidification. On the other hand, it enables the adsorbent to have heat storage and temperature regulation capabilities while having adsorption capabilities, which is beneficial for the adsorbent to complete the purification treatment of oil-containing sewage under actual complex working conditions. In addition, since the density of the inorganic hydrated salt in the phase change core material is much greater than the density of water, the density of the prepared adsorbent is close to that of water, that is, it can semi-suspend in water to adsorb oil stains, which helps to adsorb both light and heavy oil products simultaneously.

[0044] (2) The oil-containing sewage adsorbent prepared by the present invention uses flexible polyurethane as the substrate, reacts with the active amino functional groups of the peptidic substances, and simultaneously undergoes a coordination complexation reaction with the metal center in the catalyst, effectively combining the three together. This enables the adsorbent to have a superhydrophobic structure while also having a hierarchical pore structure system, enhancing its adsorption effect. In addition, the metal active center after the coordination complexation reaction also has a certain number of unsaturated active sites, which can effectively adsorb the unsaturated hydrocarbons in the heavy oil products through covalent bonding reactions, making the oil stain removal thorough and fast.

[0045] (3) Multiple hydrogen bond units can be introduced during the reaction of polyurethane and peptidic substances in the oil-containing sewage adsorbent prepared by the present invention. Multiple hydrogen bonds can not only improve the mechanical properties of the material but also appropriately increase the self-healing effect of the material itself, effectively extending the service life of the adsorbent.

[0046] (4) The preparation process of the present invention is simple, clean, environmentally friendly, easy to operate, and has high oil removal efficiency, making it suitable for large-scale applications. Description of the Drawings

[0047] Figure 1 It is a differential scanning calorimetry curve (DSC) graph of the sample of Example 1 and the sample after 20 regenerations.

[0048] Figure 2 It is a scanning electron microscope (SEM) photograph of the sample of Example 1.

[0049] Figure 3 It is a scanning electron microscope (SEM) photograph of the sample of Example 1 after 20 regenerations.

[0050] Figure 4 It is a trend graph of the adsorption capacity of the sample of Example 1 for crude oil during the variable-temperature adsorption process. Detailed Embodiments

[0051] The following examples are used to further illustrate the preparation method and effects of the oil-containing sewage adsorbent of the present invention. The examples are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following examples.

[0052] In the following examples, the experimental methods are all conventional methods in the art unless otherwise specified. The experimental materials used in the following examples are all purchased from conventional biochemical reagent stores unless otherwise specified.

[0053] In the present invention, the total pore volume = microporous and mesoporous pore volume + macroporous pore volume. Among them, the microporous and mesoporous pore volume is obtained by the BET method, and the macroporous pore volume is obtained by a mercury intrusion porosimeter.

[0054] In the present invention, a 3H-2000PM2 specific surface area tester produced by Beijing Beishide Company is used to measure the microporous and mesoporous pore volumes of the oil-containing sewage adsorbent. Before the test, the sample is vacuum degassed at 373K, and the nitrogen adsorption-desorption isotherm curve is measured at 77K. The pore volume analysis of the sample is carried out by the BET method. Among them, micropores are pores less than 2nm, and mesopores are pores of 2-50nm.

[0055] Micropore rate % = (microporous pore volume / total pore volume) × 100%,

[0056] Mesopore rate % = (mesoporous pore volume / total pore volume) × 100%.

[0057] In the present invention, the macropore volume of the oil-containing sewage adsorbent is measured using an Autopore V 9600 mercury intrusion porosimeter produced by Micromeritics Instrument Corporation of the United States. The adsorbent is subjected to vacuum drying treatment, placed in a dilatometer, the empty dilatometer is sealed and assembled, and the dilatometer containing the adsorbent is transferred to the low-pressure chamber for low-pressure analysis. After the analysis is completed, it is transferred to the high-pressure chamber for high-pressure analysis. The hydraulic oil on the mercury surface is used to increase the pressure in a graded continuous, step-by-step or ladder-like manner, the mercury column drop value is measured, and the pressure and the corresponding mercury injection volume are recorded. Macropores are pores larger than 50 nm.

[0058] Macropore ratio % = (macropore volume / total pore volume) × 100%.

[0059] In the present invention, the density of the oil-containing sewage adsorbent is measured using a D6 densitometer produced by Mettler Toledo AG of Switzerland.

[0060] In the present invention, the water contact angle of the oil-containing sewage adsorbent is measured using a JC2000D1 contact angle measuring instrument produced by Shanghai Zhongchen Digital Technology Equipment Co., Ltd. Five points are tested on the same adsorbent surface, and the results are averaged.

[0061] In the present invention, a DSC-60Plus differential scanning calorimeter produced by Shimadzu Corporation of Japan is used to test the phase change temperature point, the latent heat of fusion phase change value and the degree of supercooling of the oil-containing sewage adsorbent.

[0062] In the present invention, an XWW microcomputer-controlled electronic universal testing machine produced by Chengde Kecheng Testing Machine Co., Ltd. is used to test the compressive strength and flexural strength of the oil-containing sewage adsorbent.

[0063] In the present invention, the adsorption capacity of the adsorbent for oil-containing sewage is calculated by the following formula, where M 1 and M 0 are the masses of the adsorbent after adsorbing oil products respectively, and Q is the adsorption capacity of the adsorbent.

[0064] Q = (M 1 - M 0 ) / M 0 .

[0065] In the present invention, aqueous solutions of edible oil and crude oil with a concentration of 500 mg / L are respectively prepared before the adsorption of the oil-containing sewage, and the adsorption is carried out according to the ratio of oil-containing sewage to adsorbent of 1 mL:0.5 mg. The adsorption process is carried out in a constant temperature shaker at a temperature of 25 °C, a swing rate of 150 rpm, and a time of 30 min. The adsorption amounts of the adsorbent for edible oil and crude oil are calculated respectively.

[0066] In the present invention, the regeneration process of the oily sewage adsorbent is to mix the used adsorbent with a methanol solution at a ratio of 1 g:20 g, let it stand for 12 h, then transfer it to a vacuum drying oven, and dry it at a constant temperature of 80 °C for 6 h to obtain the regenerated adsorbent. Before use, aqueous solutions of edible oil and crude oil with a concentration of 500 mg / L are respectively prepared, and adsorption is carried out at a ratio of oily sewage to adsorbent of 1 mL:0.5 mg. The adsorption process is carried out in a constant temperature shaker at a temperature of 25 °C, a shaking rate of 150 rpm, and a time of 30 min. Then, the adsorption amounts of the adsorbent for edible oil and crude oil after 20 consecutive adsorption-regeneration cycles are calculated respectively.

[0067] Further, the variable-temperature adsorption process of the oily sewage is to prepare an aqueous solution of crude oil with a concentration of 500 mg / L, and carry out adsorption at a ratio of oily sewage to adsorbent of 1 mL:0.5 mg. The adsorption process is carried out in a constant temperature shaker. The initial adsorption temperature is 25 °C, the temperature is increased by 5 °C every 30 min, and adsorption is carried out at a constant temperature for 20 min until 70 °C, and the shaking rate is 150 rpm. The adsorption amount of the adsorbent for crude oil is calculated.

[0068] Example 1

[0069] 100 g of sodium sulfate decahydrate and 6 g of ammonium acetate are respectively taken and rapidly stirred and reacted at 150 °C and 650 rpm for 40 min to obtain a phase change core material. 100 g of polytetrahydrofuran with a molecular weight of 750 is vacuum dehydrated at 100 °C and 35 kPa for 50 min, and then under the protection of high-purity nitrogen, it is added to a reaction vessel together with 100 g of polyethersulfone with a molecular weight of 2800. Then, 25 g of isophorone diisocyanate and 0.5 g of zinc isooctanoate are successively added, and the reaction is carried out at 85 °C for 4.3 h to obtain a monomer. 50 g of γ-endorphin and 20 g of 1,6-hexanediol are dissolved in 500 g of a polyethersulfone solvent, and it is added to 28.5 g of the monomer, and the reaction is carried out by stirring at 65 °C and 700 rpm for 40 min to obtain a thin film prepolymer. 25 g of the thin film prepolymer is added to 10 g of the phase change core material, 0.85 g of a surfactant (0.57 g of octylphenol polyoxyethylene ether-10 and 0.28 g of sodium dodecyl sulfate), and 45 g of deionized water, and the reaction is carried out by high-speed stirring at 120 °C and 6500 rpm for 5.3 min, then the reaction speed is reduced to 500 rpm and the same temperature is maintained to continue the reaction for 4 h. The obtained product is centrifuged at 9000 rpm, then rinsed with anhydrous methanol, and vacuum dried at 80 °C for 7.5 h to obtain an oily sewage adsorbent, and its pore system is a three-dimensional network structure.

[0070] Example 2

[0071] Take 100 g of sodium sulfate decahydrate and 8 g of ammonium acetate respectively, and stir and react them rapidly at 150 °C and 650 rpm for 40 min to obtain the phase change core material. Take 100 g of polytetrahydrofuran with a molecular weight of 750, dehydrate it under vacuum at 100 °C and 35 kPa for 50 min, then add it together with 124 g of polyethersulfone with a molecular weight of 2800 into the reaction vessel under the protection of high-purity nitrogen. Then, add 37 g of isophorone diisocyanate and 1.3 g of zinc isooctanoate in sequence, and heat and react at 85 °C for 4.3 h to obtain the monomer. Take 50 g of γ-endorphin and 34 g of 1,6-hexanediol and dissolve them in 650 g of polyethersulfone solvent, add it to 48 g of the monomer, and stir and react at 65 °C and 700 rpm for 40 min to obtain the thin film prepolymer. Take 25 g of the thin film prepolymer and add it to 20 g of the phase change core material, 1.425 g of surfactant (0.95 g of octylphenol polyoxyethylene ether-10 and 0.475 g of sodium dodecyl sulfate), and 115 g of deionized water. Stir and react at 120 °C and 6500 rpm for 5.3 min, then reduce the reaction speed to 500 rpm and continue to react at the same temperature for 4 h. The obtained product is centrifuged at 9000 rpm, then rinsed with anhydrous methanol, and dried under vacuum at 80 °C for 7.5 h to obtain the oily sewage adsorbent, whose pore system is a three-dimensional network structure.

[0072] Example 3

[0073] Compared with Example 1, the difference is that ammonium nitrate is used instead of ammonium acetate, 3-acetyl-2,5-dimethylfuran is used instead of polytetrahydrofuran, the first polyethersulfone in Example 1 is replaced by dimethyl sulfoxide, and the second polyethersulfone is replaced by 2-methylsulfonylethanol. Other reaction conditions and material compositions remain unchanged, and an oily sewage adsorbent is obtained, whose pore system is a three-dimensional network structure.

[0074] Example 4

[0075] Compared with Example 1, the difference is that the mass of ammonium acetate is increased to 10 g. During the preparation of the monomer, the dosage of polyethersulfone in "then add it together with 100 g of polyethersulfone into the reaction vessel under the protection of high-purity nitrogen" is increased to 200 g, and the dosages of isophorone diisocyanate and zinc isooctanoate are reduced to 13 g and 0.1 g respectively. Other reaction conditions and material compositions remain unchanged, and an oily sewage adsorbent is obtained, whose pore system is a three-dimensional network structure.

[0076] Example 5

[0077] Compared with Example 1, the difference is that dicyclohexylmethane diisocyanate is used instead of isophorone diisocyanate, and stannous octoate is used instead of zinc isooctanoate. Other reaction conditions and material compositions remain unchanged, and an oily sewage adsorbent is obtained, whose pore system is a three-dimensional network structure.

[0078] Example 6

[0079] Compared with Example 1, the difference lies in that during the preparation of the monomer, the heating temperature in "heating and reacting at 85°C for 4.3 h to obtain the monomer" is reduced to 45°C, and the time is extended to 8 h, while other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network pore system.

[0080] Example 7

[0081] Compared with Example 1, the difference lies in using dynorphin A instead of γ-endorphin and using isopropanol instead of 1,6-hexanediol, while other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network pore system.

[0082] Example 8

[0083] Compared with Example 1, the difference lies in that during the preparation of the thin film prepolymer, in "taking 50 g of γ-endorphin and 20 g of 1,6-hexanediol and dissolving them in 500 g of a polyethersulfone solvent with a molecular weight of 2800, adding it to 28.5 g of the monomer, and stirring and reacting at 65°C and 700 rpm for 40 min to obtain the thin film prepolymer", the amount of 20 g of 1,6-hexanediol is reduced to 2.5 g, and the amounts of 500 g of polyethersulfone and 28.5 g of the monomer are increased to 850 g and 59.5 g respectively, while other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network pore system.

[0084] Example 9

[0085] Compared with Example 1, the difference lies in that during the preparation of the thin film prepolymer, the heating and stirring reaction temperature in "stirring and reacting at 65°C and 700 rpm for 40 min to obtain the thin film prepolymer" is increased to 100°C, and the time is shortened to 15 min, while other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network pore system.

[0086] Example 10

[0087] Compared with Example 1, the difference lies in using octylphenol polyoxyethylene ether-15 and sodium dodecylbenzenesulfonate instead of octylphenol polyoxyethylene ether-10 and sodium dodecyl sulfate respectively, while other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network pore system.

[0088] Example 11

[0089] Compared with Example 1, the difference lies in increasing the amounts of the phase change core material and the surfactant to 32.5 g and 2 g respectively, and reducing the amount of deionized water to 25 g, while other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network pore system.

[0090] Example 12

[0091] Compared with Example 1, the difference is that the high-speed stirring reaction temperature in "high-speed stirring reaction at 120 °C and 6500 rpm for 5.3 min" is increased to 150 °C, the rotation speed is reduced to 4000 rpm, and the time is extended to 12 min. The reaction rotation speed in "then reduce the reaction rotation speed to 500 rpm and continue the reaction at the same temperature for 4 h" is reduced to 200 rpm, and the reaction time is shortened to 1 h. Other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network structure of pore channels.

[0092] Example 13

[0093] Compared with Example 1, the difference is that the vacuum drying temperature of the product after washing is increased to 135 °C and the time is extended to 15 h. Other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network structure of pore channels.

[0094] Comparative Example 1

[0095] Compared with Example 1, the difference is that ammonium acetate is omitted. Other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network structure of pore channels.

[0096] Comparative Example 2

[0097] Compared with Example 1, the difference is that pentamethyldiethylenetriamine is used instead of zinc isooctanoate as the catalyst. Other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a two-dimensional pore channel system.

[0098] Comparative Example 3

[0099] Compared with Example 1, the difference is that γ-endorphin is omitted. Other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a two-dimensional pore channel system.

[0100] Comparative Example 4

[0101] Compared with Example 1, the difference is that 1,6-hexanediol is omitted. Other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network structure of pore channels.

[0102] Comparative Example 5

[0103] Compared with Example 1, the difference is that an equal mass of the cationic surfactant cetyltrimethylammonium bromide is used instead of the combination of octylphenol polyoxyethylene ether-10 and sodium dodecyl sulfate. Other reaction conditions and material compositions remain unchanged, obtaining an oily sewage adsorbent with a three-dimensional network structure of pore channels.

[0104] Comparative Example 6

[0105] According to the method described in CN112221476A, first prepare 3,4-dihydroxyphenethyl acrylamide with double bonds. Take 4 g of 3,4-dihydroxyphenethyl acrylamide with double bonds and dissolve it in 2 L of methanol, then add 1 g of dopamine hydrochloride. Weigh 800 mg of tris(hydroxymethyl)aminomethane and dissolve it in 20 mL of deionized water, and add it to the above solution. Adjust the pH value of the solution to 8.3 with Tris-HCl buffer solution. Immerse the polyurethane sponge completely in the solution and react with shaking at room temperature for 16 h to obtain a polyurethane sponge coated with 3,4-dihydroxyphenethyl acrylamide with double bonds. Take 50 g of hydrophobic olefins and dissolve them in 200 mL of absolute ethanol to obtain an aqueous solution of sulfonic acid monomer. Add 500 mg of azobisisobutyronitrile to this solution and stir to dissolve. Immerse the polyurethane sponge coated with 3,4-dihydroxyphenethyl acrylamide with double bonds in the above solution and react at 65 °C for 10 h. After completion, rinse with ultrapure water 5 times to obtain a hydrophobic / lipophilic multifunctional polyurethane sponge adsorbent.

[0106] Comparative Example 7

[0107] According to the method described in CN116059971A, mix 5 mL of epoxy hexane and 3 mL of n-hexane to obtain an organic solvent. Add 4.5 mg of 1,3,5-tris(4-aminophenyl)benzene and 3.5 mg of 2,5-dihydroxyterephthalaldehyde to the organic solvent to obtain a mixed solvent. Immerse 5 mg of melamine foam in the mixed solvent and let it stand for 24 h to obtain a mixture. Add 6 mg of scandium trifluoride to the mixture and let it stand and react at room temperature for 30 min. Thoroughly wash the product and dry it in vacuum at 80 °C for 12 h to obtain a covalent organic framework composite material Foam@COF-1. Then, prepare a mixed solvent by mixing 20 mL of toluene and 30 mL of ethanol. Add Foam@COF-1 and 0.5 mL of heptadecafluorodecyltrimethoxysilane to the mixed solvent, and under nitrogen conditions, heat and react at 120 °C for 8 h. After that, wash and dry to obtain a hydrophobic and lipophilic covalent organic framework composite material Foam@COF-2.

[0108] Test Example 1

[0109] Determine the physical and chemical properties of the oil-containing sewage adsorbents in Examples 1-13 and Comparative Examples 1-7 and the adsorbents after 20 regenerations. The specific results are shown in Table 1 and Table 2.

[0110] Table 1 Physical and chemical properties of the oil-containing sewage adsorbents prepared in Examples and Comparative Examples

[0111]

[0112]

[0113] Table 2 Physicochemical properties of the oil-containing sewage adsorbents prepared in the examples and comparative examples after 20 regenerations

[0114]

[0115]

[0116] As can be seen from Table 1, Table 2 and Figures 1 - 3 it can be seen that the oil-containing sewage adsorbent prepared by the method of the present invention has good physicochemical properties and regeneration performance. The sample of Example 1 has a relatively moderate micropore, mesopore and macropore distribution system, and its density, water contact angle, melting phase change latent heat value, compressive strength and flexural strength are 0.95 g / cm 3 ³, 178°, 173 J / g, 5.1 MPa and 6.5 MPa respectively. However, the pore size distribution of the comparative example samples is uneven, and their densities are generally lower than the water density, while the melting phase change latent heat value and water contact angle are also relatively low. After 20 consecutive adsorption-regeneration experiments, the water contact angle, melting phase change latent heat value, compressive strength and flexural strength of the sample of Example 1 still remain at 176°, 168 J / g, 5.0 MPa and 6.2 MPa. This is because the oil-containing sewage adsorbent prepared by the present invention uses flexible polyurethane as the substrate, reacts with the active amino functional groups of the phaeopectide substances, and simultaneously undergoes a coordination complexation reaction with the metal centers in the catalyst, effectively combining the three together, so that the adsorbent has a superhydrophobic structure while also having a hierarchical pore structure system. At the same time, inorganic hydrated salts and nucleating agents are used as the phase change core material, and the nucleating agent effectively reduces the supercooling degree of the inorganic hydrated salts and promotes their solidification as a nucleating component, so that the adsorbent has heat storage and temperature regulation capabilities while having adsorption capabilities. In addition, since the density of the inorganic hydrated salts in the phase change core material is much greater than the density of water, the density of the prepared adsorbent is close to that of water. The oil-containing sewage adsorbent prepared by the present invention can introduce multiple hydrogen bond units during the reaction between polyurethane and phaeopectide substances. Multiple hydrogen bonds can not only improve the mechanical properties of the material, but also appropriately increase the self-healing effect of the material itself, effectively extending the service life of the adsorbent.

[0117] Test Example 2

[0118] Determine the adsorption effects of the oil-containing sewage adsorbents in Example 1, Example 2, Example 9 and Comparative Example 1, Comparative Example 2, and Comparative Example 6 and the adsorbents after 20 regenerations on edible oil and crude oil. The specific results are shown in Table 3.

[0119] Table 3 Adsorption capacities of the samples in the examples and comparative examples and the samples after 20 regenerations for edible oil and crude oil

[0120]

[0121]

[0122] As can be seen from Table 3 and Figure 4 it can be seen that the oil-containing sewage adsorbent prepared by the present invention has good scavenging ability for both light edible oil and heavy crude oil. The adsorption amounts of the sample of Example 1 for edible oil and crude oil are 217 mg / g and 152 mg / g respectively, and the adsorbent still maintains good adsorption effect after 20 consecutive adsorption-regeneration cycles. Due to the difference in the preparation method, the density and other physical and chemical properties of the adsorption material of the comparative example sample are worse than those of the example sample, so its adsorption capacity is also lower than that of the example sample.

Claims

1. A method for preparing an adsorbent for oily wastewater, The following steps are involved: (1) Inorganic hydrated salt and nucleating agent are heated and melted to obtain a phase change core material; (2) Under the protection of an inert carrier gas, the furan compound is heated with a sulfone solvent, an isocyanate and a catalyst to obtain a monomer; (3) dissolving the peptide and alcohol substance in a sulfone solvent, mixing with the monomer of step (2), heating and reacting to obtain a film prepolymer; (4) The film prepolymer obtained in step (3) is mixed with the phase change core material, surfactant and water in step (1) to perform a first dynamic heating reaction, and then a second dynamic heating reaction is performed to obtain an oily wastewater adsorbent.

2. The method according to claim 1, It is characterized in that In step (1), the inorganic hydrated salt is selected from any one or more of disodium hydrogen phosphate dodecahydrate, calcium chloride hexahydrate and sodium sulfate decahydrate; And / or, in step (1), the nucleating agent is selected from one or more of ammonium nitrate, ammonium acetate and N-nitrosophenylamine.

3. The method according to claim 1, It is characterized in that In step (1), the mass ratio of the inorganic hydrated salt to the nucleating agent is 1:(0.007-0.1); And / or, in step (1), the temperature of the heating and melting reaction is 140° C. to 180° C., the stirring speed is 500 rpm to 800 rpm, and the time is 30 min to 60 min.

4. The method according to claim 1, It is characterized in that In step (2), the furan compound is selected from one or more of polytetrahydrofuran, 3-acetyl-2,5-dimethylfuran and 2,5-dimethoxydihydrofuran; And / or, in step (2), the inert carrier gas is selected from any one or more of high-purity nitrogen, high-purity argon and high-purity helium; And / or, in step (2), the sulfone solvent is selected from one or more of dimethyl sulfoxide, polyether sulfone and 2-methylsulfonylethanol; and / or, in step (2), the isocyanate is selected from one or more of toluene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate and lysine diisocyanate; And / or, in step (2), the catalyst is selected from one or more of zinc octoate, stannous octoate and calcium octoate.

5. The method according to claim 1, It is characterized in that In step (2), the furan compound is first subjected to vacuum dehydration before the reaction. Preferably, the vacuum dehydration temperature is 80° C. to 130° C., the time is 30 min to 60 min, and the vacuum degree is 25 kPa to 50 kPa; And / or, in step (2), the mass ratio of the furan compound, the sulfone solvent, the isocyanate and the catalyst is 1:(0.3-2):(0.13-0.68):(0.001-0.02); And / or, in step (2), the temperature of the heating reaction is 45°C to 126°C, and the time is 0.5h to 8h.

6. The method according to claim 1, It is characterized in that In step (3), the enkephalin is selected from one or more of α-endorphin, β-endorphin, γ-endorphin, dynorphin A, and dynorphin B; And / or, in step (3), the alcohol substance is selected from one or more of 1,3-propanediol, isopropanol, and 1,6-hexanediol. And / or, in step (3), the sulfone solvent is selected from one or more of dimethyl sulfoxide, polyethersulfone, and 2-methylsulfonylethanol.

7. The method according to claim 1, characterized in that in step (3), the mass ratio of the enkephalin, alcohol substance, sulfone solvent, and monomer is 1:(0.05 - 1.02):(4 - 17):(0.28 - 1.19); And / or, in step (3), the heating reaction is a heating and stirring reaction, wherein the temperature is 30°C to 100°C, the rotation speed is 600 rpm to 900 rpm, and the time is 15 min to 80 min.

8. The method according to claim 1, characterized in that in step (4), the mass ratio of the thin film prepolymer, phase change core material, surfactant, and water is 1:(0.1 - 1.3):(0.01 - 0.08):(1 - 8).

9. The method according to claim 1, characterized in that in step (4), the conditions for the first dynamic heating are a reaction temperature of 80°C to 150°C, a rotation speed of 3000 rpm to 9000 rpm, and a time of 1.5 min to 12 min; And / or, in step (4), the conditions for the second dynamic heating reaction are a reaction temperature of 80°C to 150°C, a rotation speed of 200 rpm to 1000 rpm, and a reaction time of 1 h to 10 h.

10. An oil-containing sewage adsorbent prepared by the method according to any one of claims 1 - 9.

11. The oil-containing sewage adsorbent according to claim 10, characterized in that the pore system of the oil-containing sewage adsorbent is a three-dimensional network structure, and at the same time has three pore sizes of micropores, mesopores, and macropores, the micropore rate is 10% - 20%, the mesopore rate is 25% - 45%, and the macropore rate is 40% - 60%.

12. The oil-containing sewage adsorbent according to claim 10, characterized in that The density of the oily sewage adsorbent described is 0.87 g / cm 3 ~0.95 g / cm 3 , the water contact angle is 165° - 178°, the phase change temperature is 43.7°C - 58.9°C, the latent heat value of melting phase change is 146 J / g - 173 J / g, the compressive strength is 3.5 MPa - 5.1 MPa, and the flexural strength is 4.6 MPa - 6.5 MPa.

13. An application of the oil-containing sewage adsorbent according to any one of claims 10 - 12 in an oil-containing sewage adsorption reaction.

14. The application according to claim 13, characterized in that the dosage ratio of the oil-containing sewage to the adsorbent is (0.5 mL - 5 mL) oil-containing sewage: 1 mg adsorbent.

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