A boronic acid-cyclodextrin polymer adsorbent and a preparation method and application thereof

Abstract

The application belongs to a kind of adsorbent and its preparation method, application, for cyclodextrin in adsorbing dye wastewater, it is difficult to separate from solution after dye molecule, limit the recycling use and convenience of cyclodextrin technical problem, provide a kind of boric acid-cyclodextrin polymer adsorbent and its preparation method, application, only need to mix boric acid and cyclodextrin and dissolve, then heat, drying can obtain boric acid-cyclodextrin polymer adsorbent, preparation process is carried out in water, does not need to add any organic solvent or crosslinking agent, green environmental protection, preparation process is simple and easy to operate, does not need complicated and lengthy step, as raw material, boric acid and cyclodextrin source is simple, low cost, has wide use in industry and medical field.

Description

TECHNICAL FIELD

[0001] The application belongs to an adsorbent and a preparation method and application thereof, in particular to a boric acid-cyclodextrin polymer adsorbent and a preparation method and application thereof. BACKGROUND

[0002] Dye molecules are widely used in industry and people's daily life, playing a huge role, but also causing distressing environmental pollution problems. When dye molecules are applied, a large amount of wastewater containing dyes is discharged into the environment, which can have a great impact on ecology, plants, animals and human health. Common dye molecules mainly include cationic dyes and anionic dyes, typical cationic dyes are methylene blue (MB), malachite green (MG), rhodamine B (RB), and typical anionic dyes are tartrazine (TZ) and Congo red (CR). These dye molecules not only cause water discoloration, but also most of them have irreversible damage to human health. Therefore, it is of great guiding significance to study how to efficiently and environmentally remove dye molecules for effective treatment of dye wastewater.

[0003] A common method for removing dye molecules is polymer adsorption, which has the advantages of structural design, controllable physical and chemical properties, and good reusability, and has very important application value in the process of dye molecule adsorption. Among them, cyclodextrin has become one of the popular building blocks in the field of environmental wastewater treatment due to its economy, environmental friendliness, high selectivity and structural stability. Cyclodextrin (CD) is a cyclic oligosaccharide formed by α-1, 4-glycosidic bond, usually containing 6-8 D-glucopyranose units, respectively called α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin (α-CD, β-CD and γ-CD). Because the cavity sizes of the three cyclodextrins are different, the guest molecules that can be adapted by the three cyclodextrins are not the same. In general, β-CD has the simplest production process, moderate cavity size and is the most widely used. However, cyclodextrin has a rich hydroxyl structure, and even the hydrophobic cavity structure and intramolecular hydrogen bonds will reduce its water solubility. The solubility of cyclodextrin monomers in aqueous solution is still very high, which makes it difficult to separate cyclodextrin from the solution after adsorbing pollutants, greatly limiting the recycling and convenience of the entire material. SUMMARY

[0004] The present application aims at the technical problem that it is difficult to separate the cyclodextrin from the solution after the cyclodextrin adsorbs the dye molecules in the dye wastewater, which limits the recycling and convenience of the cyclodextrin, and provides a boric acid-cyclodextrin polymer adsorbent, a preparation method and application thereof.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions to achieve the above-mentioned purpose.

[0006] In the first aspect, the present application provides a preparation method of a boric acid-cyclodextrin polymer adsorbent, comprising the following steps:

[0007] S1, mixing and dissolving boric acid and cyclodextrin in water to obtain a mixed solution;

[0008] S2, sealing and heating the mixed solution to make the boric acid and the cyclodextrin polymerize at high temperature to obtain a mixture;

[0009] S3, drying the mixture to obtain the boric acid-cyclodextrin polymer adsorbent.

[0010] Further, in step S1, the cyclodextrin is β-CD.

[0011] Further, in step S1, the mass ratio of the boric acid and the cyclodextrin is (1-5):1.

[0012] Further, in step S1, the mass ratio of the boric acid and the cyclodextrin is 1:1.

[0013] Further, in step S2, the heating is specifically heating at 160-250℃ for 3-5h.

[0014] Further, between step S2 and step S3, S2-3 is further included:

[0015] The mixture is washed with water for multiple times until the water after washing is colorless and clear.

[0016] Further, in step S3, the drying is specifically air drying at 50-80℃ for 12-24h.

[0017] Further, in step S2, the heating is specifically heating at 180℃ for 4h.

[0018] In step S3, the drying is specifically air drying at 60℃ for 12-24h.

[0019] In the second aspect, the present application provides a boric acid-cyclodextrin polymer adsorbent, which is prepared by the above-mentioned preparation method.

[0020] In the third aspect, the present application provides an application of the above-mentioned boric acid-cyclodextrin polymer adsorbent in dye wastewater treatment.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] 1. The present application proposes a preparation method of boric acid-cyclodextrin polymer adsorbent, the sources of boric acid and cyclodextrin as raw materials are simple and low in cost, and are widely used in industry and medicine, in the preparation process, only boric acid and cyclodextrin need to be mixed and dissolved, and then heated and dried to obtain the boric acid-cyclodextrin polymer adsorbent, the preparation process is carried out in water, without adding any organic solvent or crosslinking agent, which is green and environmentally friendly, the preparation process is simple and easy to operate, without complicated and lengthy steps.

[0023] 2. The present application proposes the optimal mass ratio of boric acid to cyclodextrin, heating conditions and drying conditions, on the one hand, the mild reaction conditions enable the preparation method of the present application to be applied on an industrial scale; on the other hand, the optimal combination of reaction parameters also enables the adsorbent with the optimal adsorption performance to be obtained.

[0024] 3. In the present application, β-CD is used, and the boric acid is polymerized with β-CD by using the metal-like coordination ability of boric acid, which not only enhances the polymerization degree, but also enriches the adsorption sites for dye molecules.

[0025] 4. The present application also proposes a boric acid-cyclodextrin polymer adsorbent, which overcomes the shortcomings of boric acid or cyclodextrin used alone in dye wastewater treatment, has stronger structural rigidity and enhanced adsorption performance. The adsorbent obtained by the foregoing novel polymerization method exhibits different adsorption capacities for various dye molecules, and has better adsorption for cationic dyes.

[0026] 5. The boric acid-cyclodextrin polymer adsorbent proposed by the present application can be applied in dye wastewater treatment, and of course, the adsorption performance of the adsorbent can also be utilized in other fields, which has wide application possibilities. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor.

[0028] Figure 1 SEM image of the boric acid-cyclodextrin polymer adsorbent obtained in Example 1 under 50 μm;

[0029] Figure 2 SEM image of the boric acid-cyclodextrin polymer adsorbent obtained in Example 1 under 5 μm;

[0030] Figure 3 The infrared spectra of BA, β-CD, and the obtained boric acid-cyclodextrin polymer adsorbent in Example 1 are shown below.

[0031] Figure 4 The XRD patterns of BA, β-CD, and the obtained boric acid-cyclodextrin polymer adsorbent in Example 1 are shown below.

[0032] Figure 5 The TGA graphs of BA and the obtained boric acid-cyclodextrin polymer adsorbent in Example 1 are shown.

[0033] Figure 6 The N2 adsorption-desorption curve of the boric acid-cyclodextrin polymer adsorbent obtained in Example 1 is shown below.

[0034] Figure 7 The pore size distribution diagram is shown for the boric acid-cyclodextrin polymer adsorbent obtained in Example 1.

[0035] Figure 8 The standard curve for MB solution;

[0036] Figure 9 The standard curve for MG solution;

[0037] Figure 10 The standard curve for CR solution;

[0038] Figure 11 The standard curve for RB solution;

[0039] Figure 12 The standard curve for TZ solution;

[0040] Figure 13 This is a comparison chart showing the adsorption amount and removal rate of dye molecules in five typical dye solutions by the boric acid-cyclodextrin polymer adsorbent obtained in Example 1. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the application claimed, but merely represents selected embodiments of the application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the application without creative labor fall within the scope of the application.

[0043] It should be noted that similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0044] In the description of the embodiments of the application, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the application is usually placed, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0045] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0046] In the description of the embodiments of the application, it should also be noted that unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0047] Although cyclodextrin can be applied to the treatment of dye wastewater, it is difficult to separate from the solution after adsorbing pollutants due to its very high solubility in aqueous solution. Therefore, chemical functionalization of cyclodextrin functional groups, or chemical crosslinking of cyclodextrin hydroxyl structure with other functional groups, helps cyclodextrin to separate from the solution. In addition, through such chemical crosslinking, not only the cavity structure of CD can be retained, but also the polymer can have good mechanical strength and chemical adjustability.

[0048] Boric acid (BA) also has a multi-hydroxyl structure, and can form intermolecular hydrogen bonds under certain conditions. In addition, BA will undergo dehydration condensation at high temperature. In addition, BA has a metal-like coordination ability, which provides convenience for cross-linking with other multi-hydroxyl structures, such as polyvinyl alcohol (PVA). In addition, BA is widely used in industry and medicine, and is very ideal as a building block due to its low cost and wide source. However, excessive boric acid is not good for the human body in a water environment, so cross-linking boric acid with other substances to rigidify the structure is a very effective strategy.

[0049] The present application polymerizes BA and CD compounds at high temperature, and uses water as a solvent, without the need to add excess catalyst and cross-linking agent, which is green and environmentally friendly.

[0050] The present application will be further described in detail below in conjunction with the embodiments and drawings:

[0051] Example 1

[0052] S101, in a beaker, 3g of boric acid and 3g of β-cyclodextrin were weighed, 40mL of ultrapure water was measured, a magnetic stirrer was added and placed in a magnetic stirrer to stir uniformly until the boric acid and cyclodextrin were completely dissolved, to obtain a clear and transparent mixed solution;

[0053] S102, the obtained clear and transparent mixed solution was sealed with tin foil, and then transferred to an oven at 180℃ for reaction for 4h, so that the boric acid and cyclodextrin were polymerized at high temperature. After cooling to room temperature, the mixture was taken out, washed with water three times until the clear liquid after washing was colorless and transparent, so that the mixture was more pure.

[0054] S103, the powder of the mixture obtained after washing was placed in a blast drying oven and dried at 60℃ overnight, generally 12-24h, to obtain black solid powder BA-CD, i.e. boric acid-cyclodextrin polymer adsorbent, which was ground and used.

[0055] The performance of the boric acid-cyclodextrin polymer adsorbent obtained in Example 1 was verified.

[0056] Figure 1 The SEM image of the boric acid-cyclodextrin polymer adsorbent at 50μm, Figure 2 The SEM image of the boric acid-cyclodextrin polymer adsorbent at 5μm. From the SEM image at 50μm, it can be seen that the polymer surface has very many wrinkles and ravines, which provides a convenient condition for adsorbing dye molecules, and some pore structures can be seen, and the pore structures are verified in the SEM image at 5μm. The polymer surface has very dense sponge-like pores, which is one of the strong evidences that the polymer can adsorb dye molecules in the pores.

[0057] Figure 3 The image shows the Fourier transform infrared (FT-IR) spectra of the boric acid-cyclodextrin polymer adsorbent (BA-CD) and BA and β-CD used as raw materials in step S101. BA-CD shows a peak wavelength of approximately 3500 cm⁻¹. -1 There is a peak shaped like a steamed bun at 3230 cm⁻¹, which is the stretching vibration peak of the hydroxyl group. -1 The characteristic peak at 1455 cm⁻¹ is the stretching vibration peak of CH, which has undergone a redshift compared to β-CD. Furthermore, at 1455 cm⁻¹... -1 The BA-CD polymer exhibits a distinct BO stretching vibration peak at 1710 cm⁻¹, and compared to the infrared spectra of the two raw materials, the BA-CD polymer's infrared spectrum shows an additional peak at 1710 cm⁻¹. -1 The new characteristic peaks at the [location] are presumably generated by the coordination of boric acid and the polyhydroxy structure. The infrared spectrum also clearly reflects the successful polymerization of boric acid and β-CD.

[0058] Figure 4 XRD patterns of the boric acid-cyclodextrin polymer adsorbent (BA-CD) and BA and β-CD used as raw materials in step S101. From... Figure 4 It can be clearly seen that BA-CD has both the amorphous peak of β-CD and the characteristic peak of BA at 28°, indicating that BA and β-CD underwent dehydration condensation at high temperature, thereby crosslinking β-CD through the skeleton constructed by boron-oxygen bonds. Moreover, the structure of β-CD was not destroyed during the polymerization process, so the cavity advantage of β-CD was preserved. This also provides convenient conditions for the polymer to adsorb dye molecules into the cavity.

[0059] Figure 5 The TGA (Thermogravimetric Analysis) plots of the prepared BA-CD and the raw material BA are shown. The thermogravimetric curves clearly illustrate the thermal stability of the BA-CD polymer. The weight of BA-CD continuously decreases from room temperature to 120°C. This process is due to the loss of water by the hydroxyl groups in β-CD that did not participate in polymerization. However, from 120°C to 300°C, the thermal stability of the BA-CD polymer is significantly superior, with its weight remaining essentially unchanged, which is a clear advantage compared to the continuous weight loss of the raw material BA.

[0060] Figure 6 The N2 adsorption-desorption curves of the boric acid-cyclodextrin polymer adsorbent prepared in Example 1 are shown. The N2 adsorption-desorption isotherms of BA-CD are type IV adsorption isotherms. Hysteresis is observed in both desorption curves, indicating that most of the pores inside the material are mesoporous. The obtained BET specific surface area is approximately 34.2 m². 2 The / g figure further illustrates that pore adsorption plays an indispensable role in the adsorption of dye molecules. Figure 7 This is a pore size distribution diagram of the boric acid-cyclodextrin polymer adsorbent prepared in Example 1.Figure 7 The pore size distribution of BA-CD is shown, and it can be seen that the pore size of the polymer is approximately in the range of mesopore, and the average pore size calculated by adsorption and desorption is 17.94 nm and 13.86 nm, respectively, which is consistent with the conclusion obtained by the BET curve. In summary, the specific surface area of the BA-CD polymer provides more adsorption sites for dye molecules.

[0061] Figures 8 to 12 The standard curves of MB, MG, CR, RB and TZ solutions, respectively, and the initial concentrations of MB solutions are 2 mg / L, 4 mg / L, 6 mg / L, 8 mg / L, 10 mg / L, 15 mg / L, 20 mg / L and 25 mg / L, respectively, and the initial concentrations of MG, CR, RB and TZ solutions are 2 mg / L, 4 mg / L, 6 mg / L, 8 mg / L and 10 mg / L, respectively, and the pH is 7, and the wavelength of the ultraviolet spectrophotometer is set to 665 nm at room temperature. -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1

[0062] Figure 13 The boronic acid-cyclodextrin polymer adsorbent prepared in Example 1 Figures 8 to 12 The adsorption amount and removal rate of dye molecules in the five typical dye solutions are compared. The concentration of all dye molecules is 100 mg / L, the adsorption time is 8 h, the pH is 7, and the amount of BA-CD polymer is 10 mg. Under the above experimental conditions, the adsorption amount and removal rate of several typical dye molecules are obtained. BA-CD polymer exhibits excellent adsorption capacity for MB, MG, CR, and the adsorption amount can reach 181.6 mg / g, 154 mg / g and 111.8 mg / g, respectively, and the removal rate is 90.8%, 77%, 55.9%, respectively. The adsorption amount of RB and TZ is 86.8 mg / g and 24.6 mg / g, respectively, and the removal rate is 43.4% and 12.35%, respectively. It is also proved that the boronic acid-cyclodextrin polymer adsorbent of the present application has better adsorption effect on cationic dyes.

[0063] Example 2

[0064] S201, in a beaker, boronic acid and β-cyclodextrin are weighed according to the mass ratio of 1:1, ultrapure water is added, and stirred until the boronic acid and cyclodextrin are completely dissolved to obtain a clear and transparent mixed solution; ​​​​​​​​​​​​​

[0065] S202, the obtained clear and transparent mixed solution was sealed with tin foil, then transferred to an oven at 180°C for reaction for 4h, so that boric acid and cyclodextrin were subjected to high-temperature polymerization. After being cooled to room temperature, the mixture was taken out. The mixture was washed with water for three times until the supernatant after washing was colorless and clear, so that the mixture was more pure.

[0066] S203, the mixture powder obtained after washing was placed in a blast drying oven and dried at 60°C overnight, generally for 12-24h, to obtain black solid powder BA-CD, i.e. boric acid-cyclodextrin polymer adsorbent, which was ground and used.

[0067] The adsorption effect of the boric acid-cyclodextrin polymer adsorbent obtained in Example Two was verified. The removal rate of dye molecules in the MB solution could reach 88%.

[0068] Example Three

[0069] S301, boric acid and hydroxypropyl-substituted β-cyclodextrin were weighed according to a mass ratio of 1:1, and ultrapure water was added. The mixture was stirred until the boric acid and cyclodextrin were completely dissolved, to obtain a clear and transparent mixed solution.

[0070] S302, the obtained clear and transparent mixed solution was sealed with tin foil, then transferred to an oven at 180°C for reaction for 4h, so that boric acid and cyclodextrin were subjected to high-temperature polymerization. After being cooled to room temperature, the mixture was taken out. The mixture was washed with water for three times until the supernatant after washing was colorless and clear, so that the mixture was more pure.

[0071] S303, the mixture powder obtained after washing was placed in a blast drying oven and dried at 60°C overnight, generally for 12-24h, to obtain black solid powder BA-CD, i.e. boric acid-cyclodextrin polymer adsorbent, which was ground and used.

[0072] The adsorption effect of the boric acid-cyclodextrin polymer adsorbent obtained in Example Three was verified. The removal rate of dye molecules in the MB solution could reach 85%.

[0073] Example Four

[0074] S401, boric acid and carboxymethyl-substituted β-cyclodextrin were weighed according to a mass ratio of 1:1, and ultrapure water was added. The mixture was stirred until the boric acid and cyclodextrin were completely dissolved, to obtain a clear and transparent mixed solution.

[0075] S402, the obtained clear and transparent mixed solution was sealed with tin foil, then transferred to an oven at 180°C for reaction for 4h, so that boric acid and cyclodextrin were subjected to high-temperature polymerization. After being cooled to room temperature, the mixture was taken out. The mixture was washed with water for three times until the supernatant after washing was colorless and clear, so that the mixture was more pure.

[0076] S403, the mixture powder obtained after washing is placed in a blast drying oven and dried at 60°C overnight, generally 12-24h, to obtain black solid powder BA-CD, i.e. boric acid-cyclodextrin polymer adsorbent, which is ground and used.

[0077] The adsorption effect of the boric acid-cyclodextrin polymer adsorbent obtained in Example Four is verified, and the removal rate of dye molecules in the MB solution can reach 82%.

[0078] Example Five

[0079] S501, boric acid and hydroxypropyl-substituted β-cyclodextrin are weighed according to a mass ratio of 1:1, and ultrapure water is added, and stirred until the boric acid and cyclodextrin are completely dissolved, to obtain a clear and transparent mixed solution;

[0080] S502, the clear and transparent mixed solution obtained is sealed with tin foil and then transferred to an oven at 160°C for reaction for 4h, so that the boric acid and cyclodextrin are subjected to high-temperature polymerization, and then taken out after being cooled to room temperature, to obtain a mixture. The mixture is washed with water three times until the clear liquid after washing is colorless and clear, so that the mixture is more pure.

[0081] S503, the mixture powder obtained after washing is placed in a blast drying oven and dried at 60°C overnight, generally 12-24h, to obtain black solid powder BA-CD, i.e. boric acid-cyclodextrin polymer adsorbent, which is ground and used.

[0082] It is verified that the removal rate of dye molecules in the RB solution can reach 84.5%.

[0083] Example Six

[0084] S601, boric acid and hydroxypropyl-substituted β-cyclodextrin are weighed according to a mass ratio of 1:1, and ultrapure water is added, and stirred until the boric acid and cyclodextrin are completely dissolved, to obtain a clear and transparent mixed solution;

[0085] S602, the clear and transparent mixed solution obtained is sealed with tin foil and then transferred to an oven at 220°C for reaction for 4h, so that the boric acid and cyclodextrin are subjected to high-temperature polymerization, and then taken out after being cooled to room temperature, to obtain a mixture. The mixture is washed with water three times until the clear liquid after washing is colorless and clear, so that the mixture is more pure.

[0086] S603, the mixture powder obtained after washing is placed in a blast drying oven and dried at 60°C overnight, generally 12-24h, to obtain black solid powder BA-CD, i.e. boric acid-cyclodextrin polymer adsorbent, which is ground and used.

[0087] It is verified that the removal rate of dye molecules in the RB solution can reach 83%.

[0088] Example Seven

[0089] S701, boracic acid and hydroxypropyl substituted β-cyclodextrin were weighed according to the mass ratio of 1:1, and ultrapure water was added, stirred uniformly until the boracic acid and cyclodextrin were completely dissolved to obtain a clear and transparent mixed solution;

[0090] S702, the obtained clear and transparent mixed solution was sealed with tin foil and transferred to an oven at 250°C for 5h to make boracic acid and cyclodextrin high-temperature polymerization, and then taken out after cooling to room temperature to obtain a mixture. Washed with water three times until the clear liquid after washing was colorless and transparent, and the mixture was more pure.

[0091] S703, the mixture powder obtained after washing was placed in a blast drying oven and dried at 70°C overnight, generally 12-24h, to obtain black solid powder BA-CD, i.e. boracic acid-cyclodextrin polymer adsorbent, which was ground and used.

[0092] It has been verified that the removal rate of dye molecules in RB solution can reach 84%.

[0093] Example Eight

[0094] S801, boracic acid and hydroxypropyl substituted β-cyclodextrin were weighed according to the mass ratio of 1:1, and ultrapure water was added, stirred uniformly until the boracic acid and cyclodextrin were completely dissolved to obtain a clear and transparent mixed solution;

[0095] S802, the obtained clear and transparent mixed solution was sealed with tin foil and transferred to an oven at 200°C for 3h to make boracic acid and cyclodextrin high-temperature polymerization, and then taken out after cooling to room temperature to obtain a mixture. Washed with water three times until the clear liquid after washing was colorless and transparent, and the mixture was more pure.

[0096] S803, the mixture powder obtained after washing was placed in a blast drying oven and dried at 80°C overnight, generally 12-24h, to obtain black solid powder BA-CD, i.e. boracic acid-cyclodextrin polymer adsorbent, which was ground and used.

[0097] It has been verified that the removal rate of dye molecules in MB solution can reach 87%.

[0098] Example Nine

[0099] S901, boracic acid and hydroxypropyl substituted β-cyclodextrin were weighed according to the mass ratio of 1:1, and ultrapure water was added, stirred uniformly until the boracic acid and cyclodextrin were completely dissolved to obtain a clear and transparent mixed solution;

[0100] S902, the obtained clear transparent mixed solution is sealed with tin foil and then transferred to an oven at 190 DEG C for 4h to make boric acid and cyclodextrin high-temperature polymerization, and then taken out after cooling to room temperature to obtain a mixture. Washed with water three times until the clear liquid after washing is colorless and transparent, and the mixture is more pure.

[0101] S903, the mixture powder obtained after washing is placed in a blast drying oven and dried at 50 DEG C overnight, generally 12-24h, to obtain black solid powder BA-CD, i.e. boric acid-cyclodextrin polymer adsorbent, which is ground and used.

[0102] It has been verified that the removal rate of dye molecules in the MB solution can reach 89%.

[0103] In other embodiments of the present application, when boric acid and cyclodextrin are high-temperature polymerized, as the optimal scheme, the heating temperature is controlled at 160-250 DEG C, and the heating time is controlled at 3-5h. It has been verified that if the temperature is too low, the polymer cannot be generated, and if the temperature is too high, the adsorption effect cannot meet the requirements of dye wastewater treatment. At the same time, within the preferred heating temperature range, the heating time has also been verified. When the heating temperature is controlled, the heating time is also ensured, which can make the boric acid-cyclodextrin polymer adsorbent prepared by the preparation method of the present application have better adsorption effect and meet the requirements of dye wastewater treatment.

[0104] In addition, the drying time will also affect the surface morphology of the final adsorbent, and then affect its final adsorption performance.

[0105] The invention point of the present application is not only in the preparation steps. If you want to get the adsorbent with the optimal effect, especially to meet the adsorption requirements of dye wastewater, the value and combination of each parameter in each step are also one of the invention points of the present application.

[0106] The above mainly focuses on the application of the adsorbent of the present application in dye wastewater treatment. However, due to the excellent adsorption performance, the surface morphology and specific performance of the adsorbent of the present application, it can also be applied to other adsorption fields, which can be selectively used according to actual needs.

[0107] The above is only the preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a boric acid-cyclodextrin polymer adsorbent, characterized in that, Includes the following steps: S1, mix and dissolve boric acid and cyclodextrin in water to obtain a mixed solution; the mass ratio of boric acid to cyclodextrin is (1-5):1; S2, Seal and heat the mixed solution to allow boric acid and cyclodextrin to undergo high-temperature polymerization to obtain a mixture; the heating is specifically: heating at 160-250 ℃ for 3-5 h; S3, dry the mixture to obtain boric acid-cyclodextrin polymer adsorbent, which adsorbs dye molecules in dye wastewater.

2. The method for preparing a boric acid-cyclodextrin polymer adsorbent according to claim 1, characterized in that: In step S1, the cyclodextrin is β-CD.

3. The method for preparing a boric acid-cyclodextrin polymer adsorbent according to claim 1, characterized in that: In step S1, the mass ratio of boric acid to cyclodextrin is 1:

1.

4. The method for preparing a boric acid-cyclodextrin polymer adsorbent according to claim 1, characterized in that, Between steps S2 and S3, there is also S2-3: The mixture is washed with water multiple times until the water remains colorless and clear.

5. The method for preparing a boric acid-cyclodextrin polymer adsorbent according to claim 1, characterized in that, In step S3, the drying process specifically involves drying in a forced-air environment at 50-80 ℃ for 12-24 h.

6. The method for preparing a boric acid-cyclodextrin polymer adsorbent according to claim 5, characterized in that: In step S2, the heating specifically involves heating at 180 °C for 4 hours. In step S3, the drying process specifically involves drying at 60 °C with forced air for 12-24 h.

7. A boric acid-cyclodextrin polymer adsorbent, prepared by any one of the boric acid-cyclodextrin polymer adsorbent preparation methods according to claims 1 to 6.

8. The application of the boric acid-cyclodextrin polymer adsorbent according to claim 7 in the treatment of dye wastewater.

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