Preparation method of hydrogel for adsorbing dye in wastewater
By using hydrogel materials prepared by sodium lignin sulfonate, acrylic acid and xanthan gum, the efficiency and cost of cationic dye treatment in wastewater are solved, and efficient and low-cost dye adsorption effect is achieved, and the environment and human health are protected. .
Patent Information
- Application Number
- CN202411729568.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-01-10
AI Technical Summary
The prior art is difficult to effectively remove cationic dyes in wastewater, resulting in environmental pollution and health threats, and traditional adsorption technology is costly and inefficient.
Hydrogel materials are prepared by using sodium lignin sulfonate, acrylic acid and xanthan gum as raw materials. Hydrogels with multiple adsorption sites and large specific surface areas are prepared through a simple synthesis method to adsorb cationic dyes in wastewater.
It realizes efficient adsorption of cationic dyes in wastewater, which is cheap and easy to operate, and the hydrogel can be reused, which significantly improves the effect of dye pollution treatment.
Abstract
Description
Technical Field
[0001] The invention relates to the field of dye wastewater treatment, and in particular to a method for preparing a hydrogel for adsorbing dyes in wastewater. Background Art
[0002] With the advancement of science and technology and the rapid growth of population, the number of harmful substances has increased dramatically. Among them, dyes are one of the most toxic dyes. In addition to the textile industry, organic dyes have been used in many manufacturing fields such as textiles, printing, plastics, leather, cosmetics, and personal care products. They are also used in pharmaceuticals as colorants, dyeing biological samples, and human medicine. After use, most dyes are usually discarded in rivers, lakes, and other natural water bodies. If they are discharged into natural water bodies without treatment, they will cause great environmental pollution. If they penetrate into the soil, they will pollute groundwater. Dyes such as methylene blue are the most widely used cations. Their high color saturation weakens the transmission of sunlight in water bodies, thereby inhibiting the photosynthesis of aquatic organisms and seriously threatening the ecological balance of water bodies. In addition, they are also highly toxic. Improper contact and ingestion by humans can cause adverse symptoms such as respiratory distress, diarrhea, and vomiting. Therefore, removing dyes from wastewater is crucial to protecting the environment and human health. Technologies used to prevent dye pollution include membrane separation, deep oxidation, electrochemical degradation, biodegradation, photodegradation, chemical bleaching, adsorption, and ion exchange. Compared with other technologies, adsorption technology has low cost, high efficiency and simple operation. It is the most effective technology for treating dye pollution. In addition, some new technologies, such as nanomaterials and hydrogels, are also used for water purification.
[0003] Hydrogel is a porous three-dimensional, physically or chemically cross-linked flexible chain polymer network whose unique structure allows it to absorb and retain large amounts of water without dissolving. It can be synthesized from both natural polysaccharides and synthetic polymers. As a multifunctional adsorbent material, hydrogel is used for the purification of industrial wastewater due to its specific three-dimensional network structure, functional groups (such as hydroxyl, sulfonic acid, amino, carboxyl) and reusability. Its rich functional groups promote superior adsorption capacity through physical and chemical interactions, effectively removing various pollutants such as dyes, heavy metal ions and drugs. Making it an excellent candidate for water treatment and other applications.
[0004] Therefore, in this context, this study proposes that we use sodium lignin sulfonate, acrylic acid and xanthan gum as raw materials to prepare an adsorbent hydrogel material. The prepared hydrogel has more adsorption sites, the raw materials are easily available, the operation process is simple, the cost is low, it can be reused, and it can achieve efficient adsorption of cationic dyes in wastewater. Summary of the invention
[0005] The invention provides a simple synthesis method, which is a method for preparing a sodium lignin sulfonate / acrylic acid / xanthan gum hydrogel material capable of absorbing cationic dyes such as methylene blue and malachite green.
[0006] The method for preparing SLS / AA / XG hydrogel comprises the following steps:
[0007] (1) Potassium hydroxide (KOH) is dissolved in deionized water, and acrylic acid (AA) is added in an ice water bath for neutralization. After the neutralization is completed, the solution is cooled to room temperature to obtain a neutralized solution.
[0008] (2) Sodium lignin sulfonate (SLS) is added to deionized water, stirred to dissolve, xanthan gum (XG) is added, magnetic stirring is performed, N'N-methylenebisacrylamide (MBA) and potassium persulfate (KPS) are added, and the mixture is stirred to dissolve to obtain a mixed solution.
[0009] (3) The neutralized solution obtained in step (1) is slowly added dropwise to the mixed solution of step (2), and magnetically stirred for 1 hour. The mixed solution is then placed in an ultrasonic cleaner to remove bubbles by ultrasound. The mixed solution is poured into a glass mold, placed in an oven at 60°C-70°C for thermal initiation, and cross-linked for 11h-12h before being taken out to obtain an SLS / AA / XG hydrogel composite material. The hydrogel is dried and used for dye adsorption.
[0010] In the preparation process of step (1), the mass concentration of KOH is 27%-30%, and the mass concentration of AA is 50%-55%.
[0011] In step (2), the mass concentration of SLS is 0.5%-0.7%, the mass concentration of XG is 0%-0.5%, the mass concentration of MBA is 0.053%-0.055%, and the mass concentration of KPS is 0.53%-0.55%.
[0012] Compared with the prior art, the present invention has the following benefits
[0013] (1) The raw materials used in the present invention are widely available, inexpensive, and have a simple preparation process.
[0014] (2) The hydrogel adsorbent prepared by the present invention has more adsorption sites and a larger specific surface area, a larger adsorption capacity and good reusability, and has a good adsorption effect on cationic dyes in wastewater. DETAILED DESCRIPTION
[0015] Example 1
[0016] (1) 2.744 g of potassium hydroxide (KOH) was dissolved in deionized water, and 5 ml of acrylic acid (AA) was added in an ice water bath for neutralization. After the neutralization was completed, the solution was cooled to room temperature to obtain a neutralized solution.
[0017] (2) Add 0.05 g of sodium lignin sulfonate (SLS) to deionized water, stir to dissolve, and stir magnetically. Add 0.0053 g of N'N-methylenebisacrylamide (MBA) and 0.053 g of potassium persulfate (KPS), stir thoroughly to dissolve, and obtain a mixed solution.
[0018] (3) The neutralized solution obtained in step (1) is slowly added dropwise to the mixed solution of step (2), and magnetically stirred for 1 hour. The mixed solution is then placed in an ultrasonic cleaner to remove bubbles by ultrasound. The mixed solution is poured into a glass mold, placed in an oven at 60°C-70°C for thermal initiation, and cross-linked for 11h-12h before being taken out to obtain an SLS / AA / XG hydrogel composite material. The hydrogel is dried and used for dye adsorption.
[0019] Example 2
[0020] (1) 2.744 g of potassium hydroxide (KOH) was dissolved in deionized water, and 5 ml of acrylic acid (AA) was added in an ice water bath for neutralization. After the neutralization was completed, the solution was cooled to room temperature to obtain a neutralized solution.
[0021] (2) Add 0.05 g of sodium lignin sulfonate (SLS) to deionized water, stir to dissolve, add 0.01 g of xanthan gum (XG), stir magnetically, add 0.0053 g of N'N-methylenebisacrylamide (MBA), 0.053 g of potassium persulfate (KPS), stir thoroughly to dissolve, and obtain a mixed solution.
[0022] (3) The neutralized solution obtained in step (1) is slowly added dropwise to the mixed solution of step (2), and magnetically stirred for 1 hour. The mixed solution is then placed in an ultrasonic cleaner to remove bubbles by ultrasound. The mixed solution is poured into a glass mold, placed in an oven at 60°C-70°C for thermal initiation, and cross-linked for 11h-12h before being taken out to obtain an SLS / AA / XG hydrogel composite material. The hydrogel is dried and used for dye adsorption.
[0023] Example 3
[0024] (1) 2.744 g of potassium hydroxide (KOH) was dissolved in deionized water, and 5 ml of acrylic acid (AA) was added in an ice water bath for neutralization. After the neutralization was completed, the solution was cooled to room temperature to obtain a neutralized solution.
[0025] (2) Add 0.05 g of sodium lignin sulfonate (SLS) to deionized water, stir to dissolve, and stir magnetically. Add 0.03 g of xanthan gum (XG), 0.0053 g of N'N-methylenebisacrylamide (MBA), and 0.053 g of potassium persulfate (KPS), stir to dissolve, and obtain a mixed solution.
[0026] (3) The neutralized solution obtained in step (1) is slowly added dropwise to the mixed solution of step (2), and magnetically stirred for 1 hour. The mixed solution is then placed in an ultrasonic cleaner to remove bubbles by ultrasound. The mixed solution is poured into a glass mold, placed in an oven at 60°C-70°C for thermal initiation, and cross-linked for 11h-12h before being taken out to obtain an SLS / AA / XG hydrogel composite material. The hydrogel is dried and used for dye adsorption.
[0027] Example 4
[0028] (1) 2.744 g of potassium hydroxide (KOH) was dissolved in deionized water, and 5 ml of acrylic acid (AA) was added in an ice water bath for neutralization. After the neutralization was completed, the solution was cooled to room temperature to obtain a neutralized solution.
[0029] (2) Add 0.05 g of sodium lignin sulfonate (SLS) to deionized water, stir to dissolve, and stir magnetically. Add 0.05 g of xanthan gum (XG), 0.0053 g of N'N-methylenebisacrylamide (MBA), and 0.053 g of potassium persulfate (KPS), stir to dissolve, and obtain a mixed solution.
[0030] (3) The neutralized solution obtained in step (1) is slowly added dropwise to the mixed solution of step (2), and magnetically stirred for 1 hour. The mixed solution is then placed in an ultrasonic cleaner to remove bubbles by ultrasound. The mixed solution is poured into a glass mold, placed in an oven at 60°C-70°C for thermal initiation, and cross-linked for 11h-12h before being taken out to obtain an SLS / AA / XG hydrogel composite material. The hydrogel is dried and used for dye adsorption.
[0031] Example 5
[0032] Methylene blue (MB) and malachite green (MG) were selected as model adsorbents of organic dyes. 0.01 g of dry hydrogel was placed in conical flasks containing 100 ml and 200 mg / L MB and MG solutions, respectively. The conical flasks were placed in a cyclotron oscillator (140 r / min) for oscillation adsorption. At specific time intervals, an appropriate amount of supernatant was taken from the dye solution and diluted to a suitable concentration. The absorbance of the sample was measured by ultraviolet spectrophotometry and the data was recorded.
[0033] The hydrogel composite materials prepared in Examples 1 to 4 were used in adsorption experiments. The results showed that the hydrogel prepared in Example 4 had the best adsorption effect on the two cationic dyes.
Claims
1. A method for preparing a hydrogel for adsorbing dyes in wastewater, characterized in that The method specifically comprises the following steps: (1) dissolving potassium hydroxide (KOH) in deionized water, adding acrylic acid (AA) in an ice water bath for neutralization, and cooling the solution to room temperature after the neutralization is completed to obtain a neutralized solution; (2) adding sodium lignin sulfonate (SLS) to deionized water, stirring to dissolve, adding xanthan gum (XG), magnetic stirring, adding N'N methylenebisacrylamide (MBA) and potassium persulfate (KPS), stirring to dissolve, and obtaining a mixed solution; (3) The neutralized solution obtained in step (1) is slowly added dropwise to the mixed solution of step (2), and magnetically stirred for 1 hour. The mixed solution is then placed in an ultrasonic cleaner to remove bubbles by ultrasonication. The mixed solution is poured into a glass mold, placed in an oven at 60°C-70°C for thermal initiation, and cross-linked for 11h-12h before being taken out to obtain a hydrogel composite material. The hydrogel is dried and used for dye adsorption.
2. A method for preparing a hydrogel according to claim 1, characterized in that: During the preparation process, the mass concentration of KOH is 27%-30%, and the mass concentration of AA is 50%-55%.
3. A method for preparing SLS / AA / XG hydrogel according to claim 1, characterized in that: During the preparation process, the mass concentration of SLS is 0.5%-0.7%, the mass concentration of XG is 0%-0.5%, the mass concentration of MBA is 0.053%-0.055%, and the mass concentration of KPS is 0.53%-0.55%.
4. The method for preparing SLS / AA / XG hydrogel according to claim 1, characterized in that: The hydrogel prepared by the method has a high adsorption capacity for the cationic dyes methylene blue and malachite green, and still has good adsorption performance after adsorption-desorption, thus making the hydrogel recyclable.