A biomass-based gel material for adsorbing organic pollutants and a method for preparing the same

Abstract

The application discloses a biomass-based gel material for adsorbing organic pollutants, which is prepared from a biomass precursor, and utilizes abundant functional groups in the biomass and a coupling agent to self-polymerize and form a gel network, wherein the gel material has the characteristics of a hydrogel. The application also discloses a preparation method of the biomass-based gel material and application of the biomass-based gel material in adsorbing organic pollutants. The raw materials used in the application are relatively easy to obtain, and the production cost is reduced. Further, the biomass-based gel adsorbent is prepared through a simple cross-linking self-polymerization reaction, and no additional active component or modification is needed, so that the use of chemical reagents is reduced, the biomass-based gel adsorbent can be used for adsorbing various types of organic pollutants (dyes, antibiotics and phenols), and the adsorption rate can reach 99%, so that the biomass-based gel adsorbent has wide applicability.

Description

Technical Field

[0001] This invention relates to a biomass-based gel material and its preparation method, specifically to a biomass-based gel material for adsorbing organic pollutants and its preparation method. Background Technology

[0002] my country faces increasingly severe water scarcity and pollution, with water pollution, particularly organic wastewater pollution, drawing widespread attention due to its serious harm to human health and significant negative impacts on ecosystems. Various organic pollutants, such as dyes from textile processing, leather tanning, papermaking, food processing, and hair dyeing, pharmaceutical waste from hospitals and livestock, and agricultural chemicals, exhibit persistence in ecosystems due to their complex molecular structures. Dye wastewater accounts for 17%-20% of total industrial wastewater and is among the most difficult to decompose, characterized by stability, high water solubility, non-biodegradability, and carcinogenicity. Pharmaceuticals are a significant category of emerging organic pollutants; the world uses 100,000-200,000 tons of antibiotics annually, resulting in significant drug residues in surface water, groundwater, and other environmental substrates, exhibiting remarkable persistence in water bodies. Therefore, finding practical solutions and technologies to treat organic pollutants in wastewater has become a challenging task.

[0003] Adsorption-based wastewater treatment technologies are widely recognized for their simple design, cost-effectiveness, and low energy consumption. Most existing technologies use urea, thiourea, sodium hydroxide, or graphene and carbon nanotubes to prepare gel adsorbents. These methods often involve numerous chemical reagents, complex processes, and significantly increased costs. Therefore, manufacturing cost-effective, easily regenerable adsorbents capable of effectively removing various pollutants, including dyes and antibiotics, remains a challenge. In recent years, due to the depletion of fossil resources, interest in developing renewable and sustainable adsorbent materials has increased dramatically. Biomass has received considerable attention due to its widespread availability. Biomass contains numerous active groups such as hydroxyl and carboxyl groups, exhibiting good adsorption capacity, and is a widely available, inexpensive, and environmentally friendly adsorbent material. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a biomass-based gel material for adsorbing organic pollutants and its preparation method. Utilizing the advantages of abundant functional groups in biomass, such as the ease with which they can form gel networks, this invention prepares a biomass-based gel material with excellent adsorption performance by controlling factors such as the amount of biomass used, the amount of coupling agent added, the reactant ratio, and the reaction time, and then applies it to the adsorption of organic pollutants.

[0005] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0006] A biomass-based gel material for adsorbing organic pollutants is made from biomass precursors. It utilizes the abundant functional groups in biomass and coupling agents to self-polymerize (self-react) to form a gel network, thereby adsorbing organic pollutant molecules. The gel material has hydrogel characteristics and can be reused.

[0007] The preparation method of the biomass-based gel material for adsorbing organic pollutants as described above is as follows: take a biomass precursor, add it to deionized water to prepare a biomass solution, adjust the pH value with acid, and then add alcohol, coupling agent and crosslinking agent, stir the reaction thoroughly, and obtain the biomass-based gel material after the reaction is complete; wherein, the stirring reaction time is 0.1-0.5h.

[0008] Furthermore, the biomass precursor is a large molecular biomass with a chain / network structure, such as lignin, chitosan, or dopamine, and has abundant functional groups; the mass ratio of the biomass precursor to deionized water is 1:10-1:50.

[0009] Furthermore, the acid is at least one of glacial acetic acid, hydrochloric acid, or sulfuric acid; the pH value is adjusted to 4.0-5.0.

[0010] Further, the alcohol is at least one of methanol, ethanol, or isopropanol; the mass ratio of the alcohol to the biomass precursor is 1-90:1.

[0011] Furthermore, the coupling agent is a silane coupling agent KH792; the mass ratio of the coupling agent to the alcohol is 1:10-1:20.

[0012] Furthermore, the crosslinking agent is glutaraldehyde, and the mass ratio of the crosslinking agent to the coupling agent is 1:2 to 1:5.

[0013] The application of biomass-based gel materials for adsorbing organic pollutants, as described above.

[0014] Further, the application involves taking the biomass-based gel material used for adsorbing organic pollutants, fully contacting it with the organic pollutant solution, and reacting it at 30-70℃ until adsorption equilibrium is reached. Adsorption equilibrium is generally determined based on the change in pollutant solution concentration over time. The amount of biomass-based gel material added is 0.01-2g per 100mL of organic pollutant solution (initial concentration 1-1000mg / L). After the reaction, the reaction solution is filtered using a 0.22-micron needle filter, and its concentration is then tested. When the organic pollutant is a dye, the reaction solution is detected by a UV-Vis spectrophotometer; when the organic pollutant is an antibiotic or phenol, the reaction solution is detected by high-performance liquid chromatography.

[0015] Furthermore, the organic pollutant is one of dyes, antibiotics, or phenols; the dye is one or a combination of two of crystal violet, rhodamine B, methylene blue, Congo red, and methyl orange; the antibiotic is one or a combination of two of tetracycline, sulfadiazine, and levofloxacin hydrochloride; and the phenol is one or a combination of two of phenol, o-cresol, and m-cresol.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] The raw materials used in this invention are readily available, reducing production costs. Furthermore, this invention prepares biomass-based gel adsorbents through a simple cross-linking self-polymerization reaction, without the need for external active components or modification, reducing the use of chemical reagents. It can be used to adsorb various organic pollutants (dyes, antibiotics, phenols), with an adsorption rate of up to 99%, and has wide applicability. Attached Figure Description

[0018] Figure 1 This invention describes the adsorption effect of a biomass-based gel material for adsorbing organic pollutants on different types of dyes. Detailed Implementation

[0019] The following is a detailed description of specific embodiments in conjunction with the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise specified, the raw materials and reagents used in the examples are commercially available. Alkali lignin was purchased from TCI Japan Chemicals Co., Ltd. In practical applications, lignin waste generated during the pulping and papermaking process can be used as raw materials.

[0020] Example 1

[0021] Preparation of biomass-based gel material for adsorbing organic pollutants: 0.24 g of alkali lignin was placed in a beaker, and 2.16 g of deionized water was added to dissolve it completely, obtaining a lignin solution. The pH of the obtained lignin solution was adjusted to 4.0-5.0 with 5% (v / v) glacial acetic acid. Then, 21.6 g of anhydrous methanol, 6 g of silane coupling agent (KH792), and 3 g of glutaraldehyde were added, and the mixture was stirred thoroughly for 0.5 h to obtain the biomass-based gel material for adsorbing organic pollutants, namely, the lignin-based gel material.

[0022] The lignin-based gel material prepared above is used to adsorb dyes:

[0023] Take 1.25g of the lignin-based gel material prepared above, place it in a reaction flask, and add 100mL of dye solution with an initial concentration of 60mg / L and pH=7.0 (the dye solutions are Rhodamine B, crystal violet, methylene blue, Congo red, and methyl orange, respectively). Mix well, seal, and shake at 30℃ for 12h.

[0024] After the reaction was completed, the reaction solution was filtered using a 0.22-micron syringe filter, and its concentration was then tested. The reaction solution was analyzed using a UV-Vis spectrophotometer, and the removal rate was calculated from the absorbance. The removal rates of each pollutant are shown below. Figure 1 As shown, the removal efficiency of all five dye solutions exceeded 90%, indicating that this biomass-based gel adsorbent has good adsorption effect and broad pollutant targeting.

[0025] Example 2

[0026] Preparation of biomass-based gel material for adsorbing organic pollutants: 0.24 g of dopamine (Maclean) was placed in a beaker, and 2.16 g of deionized water was added to dissolve it completely, obtaining a dopamine solution. The pH of the dopamine solution was adjusted to 4.0-5.0 with 5% (v / v) glacial acetic acid. Then, 21.6 g of methanol, 6 g of silane coupling agent (KH792), and 3 g of glutaraldehyde were added, and the mixture was stirred thoroughly for 0.5 h to obtain the biomass-based gel material for adsorbing organic pollutants, namely, the dopamine-based gel material.

[0027] The dopamine-based gel material prepared above adsorbs dyes:

[0028] Take 0.5g of the dopamine-based gel material prepared above, place it in a reaction flask, add 100mL of tetracycline solution with an initial concentration of 100mg / L and pH=7.0, mix well, seal and shake at 30℃ for 12h.

[0029] After the reaction was completed, the reaction solution was filtered using a 0.22-micron syringe filter, and its concentration was then tested. The reaction solution was analyzed by high-performance liquid chromatography, and the tetracycline removal rate was 98.34%.

[0030] Example 3

[0031] Preparation of biomass-based gel material for adsorbing organic pollutants: 0.5g of chitosan (Maclean) was placed in a beaker, and 19.5g of deionized water was added to dissolve it completely, obtaining a chitosan solution. The pH of the obtained chitosan solution was adjusted to 4.0-5.0 with 5% (v / v) glacial acetic acid. Then, 2g of methanol, 5g of silane coupling agent (KH792), and 3g of glutaraldehyde were added, and the mixture was stirred thoroughly for 0.5h to obtain the biomass-based gel material for adsorbing organic pollutants, namely, the chitosan-based gel material.

[0032] The chitosan-based gel material prepared above adsorbs dyes:

[0033] Take 0.5g of the chitosan-based gel material prepared above, place it in a reaction flask, add 100mL of phenol solution with an initial concentration of 50mg / L and pH=7.0, mix well, seal and shake at 30℃ for 12h.

[0034] After the reaction was complete, the reaction solution was filtered using a 0.22-micron syringe filter, and its concentration was then tested. The reaction solution was analyzed by high-performance liquid chromatography, and the phenol removal rate was 95.02%.

[0035] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A biomass-based gel material for adsorbing organic pollutants, characterized in that: Using biomass precursors as raw materials, a gel network is formed by self-polymerization of abundant functional groups in biomass and coupling agents, and the gel material has hydrogel characteristics.

2. The method for preparing the biomass-based gel material for adsorbing organic pollutants as described in claim 1, characterized in that: Take a biomass precursor, add water to prepare a biomass solution, adjust the pH value with acid, and then add alcohol, coupling agent and crosslinking agent, stir and react to obtain biomass-based gel material; wherein the stirring reaction time is 0.1-0.5h.

3. The method for preparing the biomass-based gel material for adsorbing organic pollutants according to claim 2, characterized in that: The biomass precursor is lignin, chitosan, or dopamine, and has abundant functional groups; the mass ratio of the biomass precursor to water is 1:10 to 1:

50.

4. The method for preparing the biomass-based gel material for adsorbing organic pollutants according to claim 2, characterized in that: The acid is at least one of glacial acetic acid, hydrochloric acid, or sulfuric acid; the pH value is adjusted to 4.0-5.

0.

5. The method for preparing the biomass-based gel material for adsorbing organic pollutants according to claim 2, characterized in that: The alcohol is at least one of methanol, ethanol, or isopropanol; the mass ratio of the alcohol to the biomass precursor is 1-90:

1.

6. The method for preparing the biomass-based gel material for adsorbing organic pollutants according to claim 2, characterized in that: The coupling agent is a silane coupling agent KH792; the mass ratio of the coupling agent to the alcohol is 1:10-1:

20.

7. The method for preparing the biomass-based gel material for adsorbing organic pollutants according to claim 2, characterized in that: The crosslinking agent is glutaraldehyde, and the mass ratio of the crosslinking agent to the coupling agent is 1:2 to 1:

5.

8. The application of the biomass-based gel material for adsorbing organic pollutants as described in claim 1 or the biomass-based gel material for adsorbing organic pollutants prepared by any of the methods described in claims 2-7 in the adsorption of organic pollutants.

9. The application according to claim 8, characterized in that: Take the biomass-based gel material used for adsorbing organic pollutants, and fully contact it with the organic pollutant solution, reacting at 30-70℃ until adsorption equilibrium is reached; wherein, the amount of biomass-based gel material used for adsorbing organic pollutants added is 0.01-2g of the biomass-based gel material used for adsorbing organic pollutants per 100mL of organic pollutant solution.

10. The application according to claim 8, characterized in that: The organic pollutant is one of dyes, antibiotics, or phenols; the dye is one or a combination of two of crystal violet, rhodamine B, methylene blue, Congo red, and methyl orange; the antibiotic is one or a combination of two of tetracycline, sulfadiazine, and levofloxacin hydrochloride; and the phenol is one or a combination of two of phenol, o-cresol, and m-cresol.

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