Preparation method of magnesium oxide modified aluminum oxide composite material and application of magnesium oxide modified aluminum oxide composite material as adsorbent for removing methyl orange
By preparing magnesium oxide modified alumina composite material as an adsorbent, the problem of difficulty in removing methyl orange in wastewater is solved, and the adsorption effect is achieved with high efficiency and low cost, which is suitable for industrial wastewater treatment.
Patent Information
- Application Number
- CN202510654376.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-21
- Publication Date
- 2025-07-22
AI Technical Summary
The prior art is difficult to efficiently remove methyl orange dyes in wastewater, and common adsorbents have problems such as high cost and low adsorption capacity.
Magnesium oxide modified alumina composite material is used as adsorbent, and by uniformly immersing the magnesium nitrate solution in the alumina carrier pores and calcining, a composite material with a large specific surface area and rich pore volume is prepared for adsorption of methyl orange dye.
The prepared magnesium-modified alumina composite has high thermal stability, fast adsorption speed and high adsorption capacity. It can still effectively remove methyl orange after cycling and regeneration, and has significant industrial application potential.
Smart Images
Figure CN120346781A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of azo dye wastewater treatment, and particularly relates to a preparation method of a magnesium oxide modified alumina composite material and its application as an adsorbent for removing methyl orange. Background Art
[0002] There are a wide variety of synthetic dyes, which are widely used in multiple industries. Among them, industries such as pharmaceuticals, textiles, cosmetics, food, and paper printing have all been revitalized with the help of dyes. However, synthetic dyes produce a large amount of wastewater, which contains various organic pollutants, harmful dyes, and heavy metal elements. The toxic and harmful substances in the wastewater pose a threat to the safety of aquatic plants, aquatic organisms, and even human lives. Therefore, dye wastewater must be scientifically treated before being discharged.
[0003] Dye removal methods can be divided into three categories, namely physical (adsorption, ion exchange, membrane filtration), chemical (coagulation - flocculation, photolysis, electrochemistry), and biological (advanced oxidation treatment methods). Although there are many effective dye removal methods, due to the limitations of most methods, only a few methods are widely used at present. Among them, the adsorption method is one of the efficient methods for treating dye wastewater.
[0004] An ideal adsorbent should have characteristics such as a large specific surface area, high adsorption capacity, and easy regeneration. Due to the characteristics of alumina, such as a large specific surface area, adjustable pore size, and rich active sites, it is often used as an adsorbent. And magnesium oxide has characteristics such as a high isoelectric point and rich surface active sites, making it also an efficient adsorbent. Summary of the Invention
[0005] The present invention provides a preparation method of a magnesium oxide modified alumina composite material and its application as an adsorbent for removing methyl orange, aiming to solve the problem of difficult removal of methyl orange in wastewater. This preparation method is simple and easy to operate, and can be widely used in the preparation of industrial adsorbents.
[0006] The preparation method of the magnesium oxide modified alumina composite material is as follows: Boehmite is calcined at 500 - 700 °C for 1 - 5 h to obtain an alumina carrier, and a magnesium nitrate solution is gradually added dropwise to the surface of the alumina carrier to uniformly impregnate the magnesium nitrate solution into the pores of the alumina carrier; finally, it is calcined at 400 - 600 °C for 1 - 4 h to obtain the magnesium oxide modified alumina composite material.
[0007] The Boehmite is prepared from aluminum sulfate and sodium metaaluminate.
[0008] The concentration of the magnesium nitrate solution is 0.4 - 2.6 mol / L.
[0009] The molar ratio of magnesium in the magnesium nitrate solution to aluminum in the alumina support is 0.1 - 1.4.
[0010] The specific surface area of the alumina support is 400 - 600 m 2 / g, and the pore volume is 1.0 - 2.0 cm 3 / g.
[0011] The specific surface area of the magnesium oxide modified alumina composite is 160 - 400 m 2 / g, and the pore volume is 0.4 - 1.4 cm 3 / g.
[0012] Application of the above-prepared magnesium oxide modified alumina composite as an adsorbent for removing methyl orange.
[0013] After the magnesium oxide modified alumina composite adsorbs methyl orange, it is calcined at 500 - 700 °C for 1 - 4 h, and then it can be regenerated and continue to be used for adsorbing and removing methyl orange dye.
[0014] The present invention has the following beneficial effects: 1. The magnesium oxide modified alumina composite prepared by the present invention has high thermal stability, and the preparation method is simple, easy to operate, and low in cost, with broad application prospects.
[0015] 2. Using the magnesium oxide modified alumina composite prepared by the present invention to adsorb and remove methyl orange dye in wastewater, the adsorption rate is fast and the adsorption capacity is high. When using 0.01 g of adsorbent to adsorb 100 mL of methyl orange solution with a concentration of 400 mg / L, the adsorption amount within 5 min can reach 43% of the equilibrium adsorption amount, and the equilibrium adsorption amount of the prepared adsorbent for methyl orange is as high as 2947 mg / g.
[0016] 3. After using the magnesium oxide modified alumina composite prepared by the present invention to adsorb and remove methyl orange and recycling it five times, the adsorption capacity for the methyl orange solution is 2666 mg / g. The reduction rate of the adsorption amount is only 9.5%. It has significant application potential in the field of industrial wastewater treatment. Description of the Drawings
[0017] Figure 1 It is the SEM image of the magnesium oxide modified alumina composite prepared in Example 1.
[0018] Figure 2 It is the XRD pattern of the magnesium oxide modified alumina composite prepared in Example 1.
[0019] Figure 3 It is the concentration - absorbance working curve of different concentrations of methyl orange standard solutions used in the present invention.
[0020] Figure 4 Adsorption amount of methyl orange by the magnesium oxide modified alumina composite prepared by the present invention with the number of regeneration times Detailed implementation manners Example 1
[0021] The alumina support was prepared by calcining boehmite at 600 °C for 2 h. The specific surface area of the prepared alumina was 507 m 2 / g, and the pore volume was 1.6 cm 3 / g. 5 mL of a magnesium nitrate solution with a concentration of 0.4 mol / L was prepared, and it was gradually added dropwise to the surface of 1 g of the alumina support for impregnation, so that magnesium nitrate was evenly dispersed on the surface and pore structure of the alumina support. Finally, it was calcined at 500 °C for 2 h to obtain the magnesium oxide modified alumina composite
[0022] 0.01 g of the above-prepared composite was weighed and added to 100 mL of a 400 mg / L methyl orange solution. After stirring at room temperature for 6 h, the adsorption equilibrium was reached. After the adsorption was completed, the solution was filtered through a filter membrane, the absorbance of methyl orange in the solution was detected, the concentration of the methyl orange solution after adsorption was calculated according to the standard curve, and then the adsorption amount of the composite to methyl orange was calculated. The adsorption amount after adsorption was 584 mg / g Example 2
[0023] Using the alumina prepared in Example 1 as the support. 5 mL of a magnesium nitrate solution with a concentration of 0.8 mol / L was prepared, and it was gradually added dropwise to the surface of 1 g of the alumina support for impregnation, so that magnesium nitrate was evenly dispersed on the surface and pore structure of the alumina support. Finally, it was calcined at 500 °C for 2 h to obtain the magnesium oxide modified alumina composite
[0024] 0.01 g of the above-prepared composite was weighed and added to 100 mL of a 400 mg / L methyl orange solution. After stirring at room temperature for 6 h, the adsorption equilibrium was reached. After the adsorption was completed, the solution was filtered through a filter membrane, the absorbance of methyl orange in the solution was detected, the concentration of the methyl orange solution after adsorption was calculated according to the standard curve, and then the adsorption amount of the composite to methyl orange was calculated. The adsorption amount after adsorption was 1158 mg / g Example 3
[0025] Using the alumina prepared in Example 1 as the support of the adsorbent. 5 mL of a magnesium nitrate solution with a concentration of 1.6 mol / L was prepared, and it was gradually added dropwise to the surface of 1 g of the alumina support for impregnation, so that magnesium nitrate was evenly dispersed on the surface and pore structure of the alumina support. Finally, it was calcined at 500 °C for 2 h to obtain the magnesium oxide modified alumina composite
[0026] Weigh 0.01 g of the composite material prepared above, add it to 100 mL of a methyl orange solution with a concentration of 400 mg / L, stir at room temperature for 6 h until adsorption equilibrium is reached. After the adsorption is completed, filter the solution with a filter membrane, detect the absorbance of methyl orange in the solution, calculate the concentration of the methyl orange solution after adsorption according to the standard curve, and then calculate the adsorption capacity of the composite material for methyl orange. The adsorption capacity after adsorption is 2515 mg / g. Example 4
[0027] Use the alumina prepared in Example 1 as the carrier of the adsorbent. Prepare 5 mL of a magnesium nitrate solution with a concentration of 2.3 mol / L, and gradually add it dropwise to the surface of 1 g of the alumina carrier for impregnation, so that magnesium nitrate is evenly dispersed on the surface and pore structure of the alumina carrier. Finally, calcine it at 500 °C for 2 h to obtain the magnesium oxide modified alumina composite material.
[0028] Weigh 0.01 g of the composite material prepared above, add it to 100 mL of a methyl orange solution with a concentration of 400 mg / L, stir at room temperature for 6 h until adsorption equilibrium is reached. After the adsorption is completed, filter the solution with a filter membrane, detect the absorbance of methyl orange in the solution, calculate the concentration of the methyl orange solution after adsorption according to the standard curve, and then calculate the adsorption capacity of the composite material for methyl orange. The adsorption capacity after adsorption is 2947 mg / g.
[0029] Calcine the composite material adsorbed with methyl orange at 600 °C for 2 h to decompose methyl orange, and obtain the regenerated adsorbent. After 5 cycles, the adsorption capacity of the adsorbent for methyl orange is still as high as 2666 mg / g. Example 5
[0030] Use the alumina prepared in Example 1 as the carrier of the adsorbent. Prepare 5 mL of a magnesium nitrate solution with a concentration of 2.6 mol / L, and gradually add it dropwise to the surface of 1 g of the alumina carrier for impregnation, so that magnesium nitrate is evenly dispersed on the surface and pore structure of the alumina carrier. Finally, calcine it at 500 °C for 2 h to obtain the magnesium oxide modified alumina composite material.
[0031] Weigh 0.01 g of the above-prepared magnesium oxide modified alumina composite material, add it to 100 mL of a methyl orange solution with a concentration of 400 mg / L, stir at room temperature for 6 h until adsorption equilibrium is reached. After the adsorption is completed, filter the solution with a filter membrane, detect the absorbance of methyl orange in the solution, calculate the concentration of the methyl orange solution after adsorption according to the standard curve, and then calculate the adsorption capacity of the composite material for methyl orange. The adsorption capacity after adsorption is 2680 mg / g.
Claims
1. A preparation method of a magnesium oxide modified alumina composite material, characterized in that, The specific operation of the preparation method is as follows: Boehmite is calcined at 500 - 700 °C for 1 - 5 h to obtain an alumina support, and a magnesium nitrate solution is added dropwise to the surface of the alumina support so that the magnesium nitrate solution is uniformly impregnated into the pores of the alumina support; finally, it is calcined at 400 - 600 °C for 1 - 4 h to obtain a magnesium oxide-modified alumina composite material.
2. The preparation method according to claim 1, wherein, The described boehmite is prepared from aluminum sulfate and sodium metaaluminate.
3. The preparation method according to claim 1, characterized in that, The concentration of the described magnesium nitrate solution is 0.4 - 2.6 mol / L.
4. The preparation method according to claim 1, characterized in that, The molar ratio of magnesium in the described magnesium nitrate solution to aluminum in the alumina support is 0.1 - 1.
4.
5. The preparation method according to claim 1, characterized in that, The specific surface area of the alumina support is 400 - 600 m 2 / g, and the pore volume is 1.0 - 2.0 cm 3 / g.
6. The preparation method according to claim 1, characterized in that, The specific surface area of the magnesium oxide modified alumina composite material is 160 - 400 m 2 / g, and the pore volume is 0.4 - 1.4 cm 3 / g.
7. Application of the magnesium oxide-modified alumina composite material prepared by the method according to any one of claims 1 - 6 as an adsorbent for removing methyl orange.
8. The application according to claim 7, characterized in that, After the magnesium oxide-modified alumina composite material adsorbs methyl orange, it is calcined at 500 - 700 °C for 1 - 4 h, and then it can be regenerated and continue to be used for adsorbing and removing methyl orange dye.