Vinasse-based adsorption foam as well as preparation method and application thereof

Abstract

The invention discloses a preparation method of vinasse-based adsorption foam in the technical field of material preparation, and the preparation method comprises the following steps: step 1, drying vinasse, crushing, sieving with a 30-50-mesh sieve, soaking with an alkaline solution for 20-30 hours, washing the vinasse, and drying again; and 2, dispersing the vinasse dried again in the step 1 into deionized water, adding sodium periodate, carrying out complete reaction in a dark place, washing, filtering and drying. And step 3, dissolving gelatin in deionized water, then adding the vinasse oxidized and dried in the step 2, adjusting the pH value to 7.5-8.5, reacting for 1.5-2.5 hours at the temperature of 30-50 DEG C, then adding glutaraldehyde, continuously reacting for 1.5-2.5 hours, and then freeze-drying to obtain the vinasse-based adsorption foam. The vinasse-based adsorption foam capable of effectively removing the methyl blue dye can efficiently remove dye small molecules in a water body.

Description

Technical Field

[0001] The invention belongs to the technical field of material preparation, and in particular relates to a distiller's grains-based adsorption foam, a preparation method and application thereof. Background Art

[0002] Distillers' grains are the solid waste left over from the cooking, fermentation, and extraction of sorghum, wheat, high-temperature koji, and rice husks during the liquor production process. They contain large amounts of unfermented protein, cellulose, and hemicellulose, as well as microbial cells with high protein content. They are widely available, inexpensive, and nutritious, making them a high-quality biomass resource. However, distillers' grains have several drawbacks, such as high water content, high acidity, and a strong odor. Improper storage or prolonged storage can lead to deterioration, resulting in an unpleasant odor and making them difficult to utilize.

[0003] Currently, research on the application of distiller's grains in feed, fertilizer, biogas production, soil remediation, and the extraction of active substances has been extensive. However, when used as feed, the high crude fiber content makes it difficult for livestock to fully digest the material, preventing the grains from fully utilizing their feed benefits and resulting in a waste of resources. The added value of distiller's grains in fertilizer, biogas production, and soil remediation is low, also leading to a waste of resources. The extraction of active substances is complex and costly, making it difficult to meet the needs of large-scale applications. Therefore, the comprehensive utilization of distiller's grains requires further in-depth and extensive research. In recent years, numerous reports have been published on the use of distiller's grains to prepare biocarbon-based functional materials, including slow-release fertilizers, adsorbents, and catalysts. These reports have positive implications for the high-value conversion and utilization of distiller's grains. Distiller's grains are inherently porous solid materials, and the cellulose, hemicellulose, and protein in them contain active functional groups such as -COOH, -OH, and -NH2. These characteristics facilitate their use as a substrate for the preparation of multifunctional materials.

[0004] Dye wastewater, generated by the use of dyes in industrial production, is characterized by high chroma, strong toxicity, and difficulty in degradation, making it a typical difficult-to-treat organic wastewater. Currently, numerous reports have been published on the use of distiller's grains (DDGs) to prepare biochar materials for the efficient removal of dye wastewater. However, the preparation process for DDGs biochar is complex, requiring high-temperature calcination for several hours under high-purity nitrogen protection, followed by activation with a strong base (potassium hydroxide). Furthermore, the resulting DDGs biochar forms a small powder, making it difficult to recycle and achieving continuous adsorption removal of dye wastewater. Consequently, the practical application of this technology is limited. Few reports exist on the use of DDGs to prepare three-dimensional porous adsorption materials for the removal of dye contaminants. Therefore, the development of a DDG-based three-dimensional porous adsorption material that can effectively separate dye wastewater is of great significance for the efficient utilization of DDGs and the adsorption removal of methyl blue dye. Summary of the Invention

[0005] The present invention aims to provide a method for preparing a vinasse-based adsorption foam, so as to provide a vinasse-based adsorption foam capable of effectively removing methyl blue dye.

[0006] A method for preparing a distiller's grains-based adsorption foam in this scheme comprises the following steps:

[0007] Step 1: Dry the vinasse and crush it through a 30-50 mesh sieve, then soak it in an alkaline solution for 20-30 hours, then wash the vinasse and dry it again;

[0008] Step 2: Disperse the vinasse dried again in step 1 into deionized water, add sodium periodate, and after complete reaction in the dark, wash, filter, and dry;

[0009] Step 3: Dissolve gelatin in deionized water, add the vinasse oxidized and dried in step 2, adjust the pH to 7.5-8.5, react at 30-50°C for 1.5-2.5 hours, then add glutaraldehyde, continue the reaction for 1.5-2.5 hours, and then freeze-dry to obtain vinasse-based adsorption foam.

[0010] This approach leverages the abundant cellulose and hemicellulose content of distiller's grains. Using sodium periodate as an oxidant, the lees are first oxidized to impart a large number of aldehyde groups to their surface. This aldehyde group then reacts with gelatin as a multi-aldehyde crosslinker to form a hydrogel. After freeze-drying, a lees-based three-dimensional foam is produced. This foam is then used to adsorb dyes, achieving continuous adsorption and removal of dye wastewater. The lees-based adsorption foam prepared by this method can efficiently remove small dye molecules from water, providing a new solution to the important scientific challenge of distiller's grains conversion and utilization.

[0011] Furthermore, in step 1, the alkaline solution is a 5% to 15% NaOH solution, preferably with a concentration of 10%.

[0012] Furthermore, in step 1, the drying temperature of the lees before crushing and after washing is 50-120°C.

[0013] Furthermore, in step 2, the concentration of sodium periodate is 0.5-4 g / L, and the weight ratio of sodium periodate to vinasse is 0.01-0.8.

[0014] Furthermore, in step 2, the light-proof reaction time is 2 to 24 hours, and the reaction temperature is 25 to 35°C.

[0015] Furthermore, in step three, the concentration of the gelatin after being dissolved in deionized water is 20-80 g / L, and the weight ratio of the lees to the gelatin is 2-8:5.

[0016] Furthermore, in step three, the addition ratio of glutaraldehyde to vinasse is 1-5 mL:5 g.

[0017] Experimental verification shows that the lees-based adsorption foam prepared in this application has good adsorption performance for dye wastewater, so we also request protection for the lees-based adsorption foam prepared by the above method and its use in dye wastewater treatment. Furthermore, the dye is methyl blue dye.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) Taking advantage of the fact that wine lees contain cellulose and hemicellulose, a three-dimensional porous foam material is prepared. The material has the characteristics of large specific surface area, large separation flux and excellent adsorption performance.

[0020] (2) The present invention directly utilizes wine dregs to prepare porous functional materials, eliminating the steps of wine dregs pretreatment and effective ingredient extraction, and has the characteristics of simple process, low cost and green environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a scanning electron microscope image of the lees-based adsorption foam prepared in Example 1.

[0022] Figure 2 This is a graph showing nitrogen adsorption and desorption curves of the lees-based adsorption foam prepared in Example 1 and a blank sample.

[0023] Figure 3 This is a penetration curve diagram of the wine lees-based adsorption foam prepared in Example 1 for separating dyes of different concentrations. DETAILED DESCRIPTION

[0024] The following is further described in detail through specific implementation methods:

[0025] It is important to note that the details of the specific embodiments are intended solely to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the above-described disclosure are also considered to fall within the scope of protection of the present invention. It should be emphasized that the substrate dimensions described in the specific embodiments herein are merely for the purpose of describing the present invention in detail and are not intended to limit the present invention.

[0026] Example 1: A method for preparing a distiller's grains-based adsorption foam, comprising the following steps:

[0027] (1) Wash the lees, then place them in an oven and dry them at 90°C for 24 hours, then crush them and pass them through a 40-mesh sieve, then soak them in 10% NaOH solution for 24 hours, then wash the lees with deionized water and dry them again at 90°C for 24 hours.

[0028] (2) Weigh 5 g of vinasse and disperse it in 100 mL of deionized water, add 0.4 g of sodium periodate, and react in the dark, then wash, filter, and dry at 90 °C. The reaction temperature in the dark is 25 °C, and the reaction time is 12 h.

[0029] (3) Weigh 4 g of gelatin and dissolve it in 100 mL of deionized water. Then add the oxidized lees from step (2) to the solution, adjust the pH to 8, react at 40° C. for 2 h, then dropwise add 2 mL of glutaraldehyde, continue to react for 2 h, and then freeze-dry. Freeze-drying can be carried out using conventional procedures in the art.

[0030] The only difference between Example 2 and Example 1 is that the amount of gelatin added is 6 g.

[0031] The only difference between Example 3 and Example 1 is that the amount of gelatin added is 8 g.

[0032] The only difference between Example 4 and Example 3 is that the amount of glutaraldehyde added is 1 ml.

[0033] Performance testing:

[0034] (1) Surface morphology test

[0035] The surface morphology of the W / N fabric was observed using a JEOL JSM-5900LV scanning electron microscope, and the sample surface was sprayed with gold before testing.

[0036] (2) Specific surface area test

[0037] A sample of distiller's grains-based foam was dried in a constant-temperature drying oven at 105°C for 4 hours to remove free and adsorbed water. The specific surface area of ​​the sample was measured using nitrogen adsorption. The experimental data was analyzed using the BET theoretical model. The specific surface area of ​​the sample was calculated by plotting the nitrogen adsorption versus relative pressure.

[0038] (3) Adsorption performance test

[0039] The fixed-bed adsorption method was used to evaluate the dye adsorption performance of the prepared distiller's grains-based foam. The prepared distiller's grains-based foam was crushed and loaded into a chromatography column. The dye solution was then pumped into the column from the top. After being adsorbed by the foam, the solution flowed out from the bottom of the column. The separated liquid was collected and tested.

[0040] The scanning electron microscope images of the lees-based foams prepared in Examples 1 to 4 show that the lees-based foams all have three-dimensional porous structures. Figure 1 As shown in the figure, the foam has a three-dimensional porous structure and a specific surface area of ​​0.5894 m 2 / g, much higher than the foam made without adding lees (blank group), as shown in the attached Figure 2 As shown in FIG, the preparation process of the blank group was as follows: 4 g of gelatin was weighed and dissolved in 100 mL of deionized water, the pH was adjusted to 8, 2 mL of glutaraldehyde was added dropwise at 40° C., reacted for 2 h, and then freeze-dried.

[0041] When the lees-based foams prepared in Examples 1 to 4 were used for continuous adsorption and removal of methyl blue dyes at different concentrations, the filtrates were all clear and transparent, and the methyl orange concentration in the filtrate was almost zero. When the methyl blue dye concentration was 50 mg / L, the collected filtrate was about 170 mL, and the separation flux was as high as 1528 L / m 2 ·h.

[0042] The above is only an embodiment of the present invention, and the common knowledge such as the specific structure and characteristics of the scheme is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing a distiller's grains-based adsorption foam, characterized in that: The following steps are involved: Step 1: Dry the vinasse and crush it through a 30-50 mesh sieve, then soak it in an alkaline solution for 20-30 hours, then wash the vinasse and dry it again; Step 2: Disperse the vinasse dried again in step 1 into deionized water, add sodium periodate, and after complete reaction in the dark, wash, filter, and dry; Step 3: Dissolve gelatin in deionized water, add the vinasse oxidized and dried in step 2, adjust the pH to 7.5-8.5, react at 30-50°C for 1.5-2.5 hours, then add glutaraldehyde, continue the reaction for 1.5-2.5 hours, and then freeze-dry to obtain vinasse-based adsorption foam.

2. The method for preparing a distiller's grains-based adsorption foam according to claim 1, wherein: In step 1, the alkaline solution is a 5% to 15% NaOH solution.

3. The method for preparing a distiller's grains-based adsorption foam according to claim 2, characterized in that: In step 1, the drying temperature of the lees before crushing and after washing is 50-120°C.

4. The method for preparing a distiller's grains-based adsorption foam according to claim 3, characterized in that: In step 2, the concentration of sodium periodate is 0.5-4 g / L, and the weight ratio of sodium periodate to vinasse is 0.01-0.

8.

5. The method for preparing a distiller's grains-based adsorption foam according to claim 4, characterized in that: In step 2, the light-proof reaction time is 2 to 24 hours, and the reaction temperature is 25 to 35°C.

6. The method for preparing a distiller's grains-based adsorption foam according to claim 5, characterized in that: In step 3, the concentration of the gelatin after being dissolved in deionized water is 20-80 g / L, and the weight ratio of lees to gelatin is 2-8:

5.

7. The method for preparing a distiller's grains-based adsorption foam according to claim 6, characterized in that: In step 3, the addition ratio of glutaraldehyde to vinasse is 1-5 mL:5 g.

8. A distiller's grains-based adsorption foam, characterized by: It is obtained according to the method for preparing a distiller's grains-based adsorption foam according to any one of claims 1 to 7.

9. Use of the vinasse-based adsorption foam according to claim 8 in the treatment of dye wastewater.

10. Use of the vinasse-based adsorption foam in dye wastewater treatment according to claim 9, characterized in that: The dye is methyl blue.

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