CN117299095A - A binary compound lignin-based airgel adsorption material and its preparation method and application - Google Patents

Abstract

The invention belongs to the technical field of water treatment, and specifically relates to a binary compound lignin-based airgel adsorption material and its preparation method and application. The binary compound lignin-based airgel adsorbent material is compounded of lignin sulfonate and carboxyxylan, and polymerized and frozen with acrylamide, cross-linking agent, initiator and tetramethylethylenediamine. Produced by drying. The invention uses green, non-toxic and widely sourced industrial waste lignosulfonate as raw material, utilizes its aromatic properties and sulfonic acid group anions to compound carboxyxylan for collaborative adsorption, and obtains it through simple solution blending and freeze-drying. The airgel adsorption material has the advantages of low cost, environmental friendliness, simple synthesis process, and safe operation, and can be applied to the efficient removal of methylene blue from printing and dyeing wastewater.

Description

A binary compound lignin-based airgel adsorption material and its preparation method and application

Technical field

The invention belongs to the technical field of water treatment, and specifically relates to a binary compound lignin-based airgel adsorption material and its preparation method and application.

Background technique

Methylene blue is an organic pollutant that is harmful to the human body. The development of efficient water treatment technology to remove methylene blue from printing and dyeing wastewater is of great significance for solving water pollution and maintaining the health of the human living environment. Compared with water treatment technologies such as flocculation, precipitation, and oxidation, the adsorption method is expected to be widely used in the treatment of printing and dyeing wastewater due to its simple operation and no pollution. However, currently commonly used adsorbent materials have low adsorption rates and are difficult to regenerate. In contrast, aerogels have the advantages of low density, high specific surface area, high porosity and pore volume, and have broad application prospects in the field of adsorption. However, the preparation of traditional inorganic and organic aerogels often involves the application of toxic and harmful reagents such as acids, alkalis and organic reagents, which has a certain harmful effect on the ecological environment and human health, and the cost is high, limiting its industrial application. Therefore, finding a green, non-toxic, environmentally friendly and low-cost aerogel material is a research focus in the field of wastewater treatment.

Lignin is an abundant renewable organic carbon resource in nature, mainly found in industrial wastes such as papermaking. It has the advantages of being green, non-toxic, biocompatible, degradable and low-priced. In addition, lignin is rich in aromatic structures, and its structure contains rich functional groups such as methoxy groups, carbonyl groups, phenolic hydroxyl groups, etc., and has high reactivity, making it an ideal aerogel synthetic material. At present, existing lignin-based aerogel materials used for the adsorption of methylene blue in water are mostly prepared by composites of graphene oxide and lignin. For example, Li et al. (International Journal of Biological Macromolecules, 2020, 143, 325-333) used graphene oxide and alkali lignin to composite to prepare airgel adsorption materials. Li et al. (International Journal of Biological Macromolecules, 2019, 136, 927- 935) used graphene oxide, lignosulfonate and chitosan to prepare airgel adsorption materials. However, the preparation process of graphene oxide is complicated and involves the use of strong oxidants potassium permanganate and hydrogen peroxide, causing certain operational safety hazards. Therefore, for methylene blue wastewater treatment, it is necessary to develop efficient lignin-based airgel adsorption materials with simple synthesis process and safe operation.

Contents of the invention

In response to the above needs, the present invention developed a binary compound lignin-based airgel adsorption material. In view of the structural characteristics of the target pollutants, lignosulfonate is used as raw material and compounded with carboxylated xylan to collaboratively adsorb methylene blue in water. The invention uses environmentally friendly biomass raw materials, and can obtain airgel materials through simple solution blending and freeze-drying. It has the characteristics of simple synthesis process, safe operation, green and non-toxic, and low cost, and can better meet people's needs. Demand for airgel adsorbent materials.

The technical solution adopted by the present invention is:

A binary compound lignin-based airgel adsorption material, consisting of 1.0-5.0wt% lignosulfonate, 0-10.0wt% carboxyxylan, 5.0-20.0wt% acrylamide, 1.0- It is made by reacting 5.0wt% cross-linking agent, 0.5-2.5wt% initiator and 0.5-2.5wt% tetramethylethylenediamine.

Further, in the above-mentioned binary compound lignin-based airgel adsorption material, the lignosulfonate is one or a combination of two of sodium lignosulfonate and calcium lignosulfonate.

Further, in the above-mentioned binary compound lignin-based airgel adsorption material, the carboxyxylan is carboxymethylxylan or carboxyethylxylan.

Further, in the above-mentioned binary compound lignin-based airgel adsorption material, the cross-linking agent is N, N’-methylene bisacrylamide or aluminum hydroxide.

Further, the above-mentioned binary compound lignin-based airgel adsorption material, the initiator is hydrogen peroxide, ammonium persulfate, potassium persulfate, benzoyl peroxide, benzoyl tert-butyl peroxide One of the esters and methyl ethyl ketone peroxide.

The preparation method of the above-mentioned binary compound lignin-based airgel adsorption material includes the following steps:

1) Add 5.0-20.0wt% acrylamide, 1.0-5.0wt% cross-linking agent, 0-10.0wt% carboxyxylan, and 1.0-5.0wt% lignosulfonate into 20 mL deionized water. And stir at room temperature for 2h, then add 0.5-2.5wt% initiator and 0.5-2.5wt% tetramethylethylenediamine, stir evenly, and then further polymerize the resulting solution at room temperature for 12h to obtain water. gel;

2) Wash the hydrogel with deionized water, then put it into a freeze dryer and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

A binary compound lignin-based airgel adsorption material described in any one of the above is used to adsorb methylene blue in printing and dyeing wastewater.

Further, the above-mentioned application method is as follows: adjust the pH value of the methylene blue solution to 1-14, and add a binary compound lignin-based airgel adsorption material to it for adsorption.

Furthermore, for the above application, the concentration of the methylene blue solution is 10-200 mg/mL and the volume is 50 mL; the dosage of the binary compound lignin-based airgel adsorption material is 0.01-0.09g.

Furthermore, the conditions for the above-mentioned application of adsorption are: the adsorption temperature is 10-80°C, and the adsorption time is 5-1440 minutes.

The beneficial effects of the present invention are:

1. In view of the high cost of airgel materials, the extremely low-cost industrial waste resource lignosulfonate is used to significantly reduce the cost of airgel materials and bring considerable economic benefits.

2. In view of the problem of using toxic and harmful reagents in traditional aerogels, using biomass raw materials with good biocompatibility and degradability can greatly avoid harm to the human body and pollution to the environment during the production process.

3. In view of the problem of traditional aerogels using non-renewable raw materials, renewable organic carbon materials from a wide range of sources are used to promote the recycling of carbon resources.

4. To address the problem of limited adsorption efficiency of single lignin, carboxyxylan was added to the aerogel to synergistically adsorb lignosulfonate and carboxyxylan to improve the adsorption efficiency of methylene blue.

5. In order to solve the problems of complex process and unsafe operation of existing lignin-based aerogel materials, simple solution blending and freeze-drying steps are adopted to simplify the synthesis process and ensure high operational safety.

Detailed ways

The present invention will be further described in detail below with reference to examples, but the implementation of the present invention is not limited thereto.

Example 1

Disperse 0.9900g xylan in 9.00L of a mixed solution of 20% alcohol and water, stir for 10 minutes, then add 4.93mL of 25wt% NaOH solution at 30°C, and after stirring for 30 minutes, add 3.4900 g of sodium chloroacetate, and react at 65°C for 2 hours; then, add 4.93mL of 25wt% NaOH solution and 3.4900g of sodium chlorate, and continue the reaction at 65°C for 2 hours. After the reaction is completed, the pH value of the obtained solution is adjusted to 7 with dilute acetic acid, and then the mixed solution is slowly added to ethanol. At this time, a precipitate is formed in the ethanol solution. The obtained precipitate is washed three times with 95% ethanol, and then After drying in an oven at 50°C for 48 hours, the obtained sample is carboxymethylxylan.

Example 2

Add 7.5wt% acrylamide, 3.0wt% N,N'-methylenebisacrylamide, 10.0wt% carboxymethylxylan, and 5.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask with a pH of 6.9. Then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above and adsorb at room temperature for 24 hours. Use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 28.45% and the adsorption capacity is 13.34mg/g.

Example 3

Add 17.5wt% acrylamide, 3.0wt% N,N'-methylenebisacrylamide, 10.0wt% carboxymethylxylan, and 5.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask with a pH of 6.9. Then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above and adsorb at room temperature for 24 hours. Use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 24.06% and the adsorption capacity is 11.16mg/g.

Example 4

Add 10.0wt% acrylamide, 2.0wt% N,N'-methylenebisacrylamide, 10.0wt% carboxymethylxylan, and 5.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask with a pH of 6.9. Then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above and adsorb at room temperature for 24 hours. Use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 3.14% and the adsorption capacity is 1.35 mg/g.

Example 5

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 10.0wt% carboxymethylxylan, and 5.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask with a pH of 6.9. Then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above and adsorb at room temperature for 24 hours. Use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 30.40% and the adsorption capacity is 13.64mg/g.

Example 6

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 10.0wt% carboxymethylxylan, and 5.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.0wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask with a pH of 6.9. Then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above and adsorb at room temperature for 24 hours. Use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 54.10% and the adsorption capacity is 28.59mg/g.

Example 7

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 10.0wt% carboxymethylxylan, and 5.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 2.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask with a pH of 6.9. Then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above and adsorb at room temperature for 24 hours. Use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 27.61% and the adsorption capacity is 14.20 mg/g.

Example 8

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 5.0wt% carboxymethylxylan, and 5.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask with a pH of 6.9. Then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above and adsorb at room temperature for 24 hours. Use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 31.54% and the adsorption capacity is 15.19mg/g.

Example 9

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 10.0wt% carboxymethylxylan, and 1.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask with a pH of 6.9. Then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above and adsorb at room temperature for 24 hours. Use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 16.56% and the adsorption capacity is 8.07mg/g.

Example 10

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 3, then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at room temperature for 24 hours. , use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 19.48% and the adsorption capacity is 9.74mg/g.

Example 11

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 11, then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at room temperature for 24 hours. , use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 40.22% and the adsorption capacity is 17.80mg/g.

Example 12

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 11, then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at room temperature for 15 minutes. , use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 4.06% and the adsorption capacity is 3.87mg/g.

Example 13

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 11, then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at room temperature for 720 minutes. , use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 17.38% and the adsorption capacity is 26.83mg/g.

Example 14

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 11, then add 0.0100 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at room temperature for 720 minutes. , use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 15.94% and the adsorption capacity is 38.31mg/g.

Example 15

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 11, then add 0.0900 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at room temperature for 720 minutes. , use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 28.96% and the adsorption capacity is 7.95mg/g.

Example 16

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 10 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 11, then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at room temperature for 720 minutes. , use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 34.38%, and the adsorption capacity is 5.87mg/g.

Example 17

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 200 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 11, then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at room temperature for 720 minutes. , use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 8.34% and the adsorption capacity is 30.34mg/g.

Example 18

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 11, then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at 20°C. At 720 minutes, use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 31.32% and the adsorption capacity is 24.77mg/g.

Example 19

Add 10.0wt% acrylamide, 5.0wt% N,N'-methylenebisacrylamide, 8.0wt% carboxymethylxylan, and 4.0wt% sodium lignosulfonate to 20mL deionized water. And stir at room temperature for 2h, then add 1.5wt% ammonium persulfate and 1.5wt% tetramethylethylenediamine to it, stir evenly, the hydrogel begins to form, and then the resulting solution is further polymerized at room temperature for 12h. , to obtain a hydrogel; wash the hydrogel with deionized water, then put it into a freeze dryer, and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material.

Take 50 mL of methylene blue solution with a concentration of 50 mg/L and place it in a 250 mL Erlenmeyer flask, adjust the pH to 11, then add 0.0500 g of the binary compound lignin-based airgel adsorption material prepared above, and adsorb at 40°C. 720min, use a UV-visible spectrophotometer to detect the absorbance of methylene blue in the solution, and calculate the removal rate and adsorption capacity. The removal rate is 51.11%, and the adsorption capacity is 39.80mg/g.

The above is an exemplary description of the present invention. Without departing from the core of the present invention, any simple transformation, modification, replacement, combination, and simplification are all equivalent replacements and are included in the protection scope of the present invention. .

Claims (10)

1. A binary compound lignin-based airgel adsorbent material, characterized in that the binary compound lignin-based airgel adsorbent material is composed of 1.0-5.0wt% lignin sulfonate, 0 -10.0wt% carboxyxylan, 5.0-20.0wt% acrylamide, 1.0-5.0wt% cross-linking agent, 0.5-2.5wt% initiator and 0.5-2.5wt% tetramethylethylenediamine Made by reaction. 2. A binary compound lignin-based airgel adsorbent material according to claim 1, characterized in that the lignosulfonate is one of sodium lignosulfonate and calcium lignosulfonate. one or a combination of two. 3. A binary compound lignin-based airgel adsorption material according to claim 1, characterized in that the carboxyxylan is carboxymethylxylan or carboxyethylxylan. 4. A binary compound lignin-based airgel adsorbent material according to claim 1, characterized in that the cross-linking agent is N, N'-methylene bisacrylamide or aluminum hydroxide. 5. A kind of binary composite lignin-based airgel adsorbent material according to claim 1, characterized in that the initiator is hydrogen peroxide, ammonium persulfate, potassium persulfate, benzoyl peroxide , one of benzoyl tert-butyl peroxide and methyl ethyl ketone peroxide. 6. The preparation method of a binary compound lignin-based airgel adsorbent material according to claim 1, characterized in that it includes the following steps: 1) Add 5.0-20.0wt% acrylamide, 1.0-5.0wt% cross-linking agent, 0-10.0wt% carboxyxylan, and 1.0-5.0wt% lignosulfonate into 20 mL deionized water. And stir at room temperature for 2h, then add 0.5-2.5wt% initiator and 0.5-2.5wt% tetramethylethylenediamine, stir evenly, and then further polymerize the resulting solution at room temperature for 12h to obtain water. gel; 2) Wash the hydrogel with deionized water, then put it into a freeze dryer and dry it at -50°C for 48 hours to obtain a binary compound lignin-based airgel adsorption material. 7. A binary compound lignin-based airgel adsorption material according to any one of claims 1 to 5 is used to adsorb methylene blue in printing and dyeing wastewater. 8. The application according to claim 7, characterized in that the method is as follows: adjust the pH value of the methylene blue solution to 1-14, and add a binary compound lignin-based airgel adsorption material therein for adsorption. 9. The application according to claim 8, characterized in that the concentration of the methylene blue solution is 10-200 mg/mL and the volume is 50 mL; the dosage of the binary compound lignin-based airgel adsorption material is 0.01-0.09 g. 10. The application according to claim 8, characterized in that the adsorption conditions are: adsorption temperature is 10-80°C, and adsorption time is 5-1440 min.