Methods for Wastewater Treatment and Resource Utilization of Chromium-Containing Aluminum Profiles Based on Bio-Based Microspheres

Abstract

This invention discloses a method for treating and utilizing chromium-containing aluminum profile wastewater based on bio-based microspheres. First, bio-based microspheres are synthesized using alkali lignin as the main raw material. These microspheres are then used to treat the chromium-containing aluminum profile wastewater, obtaining chromium-immobilized aluminum profile sludge. The chromium-immobilized sludge is then calcined and vibrated to obtain activated aluminum profile sludge. Finally, the activated sludge is used for wastewater adsorption. The bio-based microspheres contain a large number of carboxyl groups and exhibit self-aggregation and flocculation effects, achieving multi-effect treatment of chromium-containing aluminum profile wastewater. During calcination, the chromium adsorbed on the surface of the bio-based microspheres forms chromium oxide protective microspheres. Vibration activation exposes the active sites inside the bio-based microspheres, which, together with the pore structure and alumina, act on the wastewater adsorption. This achieves the resource utilization of chromium-containing aluminum profile wastewater.

Description

Technical Field

[0001] This invention relates to a wastewater treatment and resource utilization method, and more particularly to a method for treating and utilizing wastewater from chromium-containing aluminum profiles based on bio-based microspheres. Background Technology

[0002] Aluminum profile manufacturers use various additives to treat the surface of aluminum profiles during production, generating wastewater. This wastewater, after adjustment, neutralization, flocculation, sedimentation, and filtration, yields sludge, which is known as aluminum profile sludge. According to statistics, on average, producing one ton of aluminum profiles in my country generates approximately 100 kilograms of aluminum profile sludge. Currently, my country's aluminum profile production reaches 200,000 tons, and it is conservatively estimated that production will continue to increase with economic development; therefore, the amount of aluminum profile sludge will also increase accordingly.

[0003] Chromium-containing aluminum profile wastewater is a special type of aluminum profile wastewater, as its treatment produces chromium-containing aluminum profile sludge. In 2021, the Ministry of Environmental Protection released a new version of the "National Hazardous Waste List," classifying chromium-containing aluminum profile sludge, which accounts for 10%-15% of the total aluminum profile sludge, as hazardous waste. Furthermore, because aluminum and chromium compounds in the sludge have similar chemical properties—both are poorly soluble in water but soluble in strong acids and alkalis—chromium cannot be easily separated from the aluminum profile sludge through alkaline or acidic dissolution.

[0004] In recent years, scholars have conducted research on the reuse of aluminum profile sludge. However, chromium-containing aluminum profile sludge, as a special type of aluminum profile sludge, carries the risk of chromium spillage, which limits its resource utilization. Therefore, it is necessary to treat the chromium during the treatment of chromium-containing aluminum profile wastewater to obtain harmless and recyclable chromium-containing aluminum profile sludge. Summary of the Invention

[0005] To address the shortcomings and deficiencies of the existing technologies, the present invention aims to provide a method for the treatment and resource utilization of chromium-containing aluminum profile wastewater based on bio-based microspheres. This invention synthesizes bio-based microspheres using alkali lignin as the main raw material; treats chromium-containing aluminum profile wastewater using these microspheres to obtain chromium-immobilized aluminum profile sludge; calcines and vibrates the chromium-immobilized aluminum profile sludge to obtain activated aluminum profile sludge; finally, the activated aluminum profile sludge is used for wastewater adsorption. The bio-based microspheres prepared by this invention contain a large number of carboxyl groups and exhibit self-aggregation and flocculation effects, achieving multi-effect treatment of chromium-containing aluminum profile wastewater and obtaining chromium-immobilized aluminum profile sludge. During sludge calcination, the chromium adsorbed on the surface of the bio-based microspheres forms chromium oxide protective microspheres. Vibration activation exposes the active sites inside the bio-based microspheres, which, together with the pore structure and alumina, make the activated aluminum profile sludge a highly efficient adsorbent. This achieves the resource utilization of chromium-containing aluminum profile wastewater.

[0006] To solve its technical problems, the technical solution adopted by the present invention is: a method for the treatment and resource utilization of chromium-containing aluminum profile wastewater based on bio-based microspheres, comprising the following steps:

[0007] (1) Synthesis of bio-based microspheres:

[0008] Take 2-15 parts by weight of alkali lignin and 2-10 parts by weight of isocyanate methacrylate in a flask, add 20-80 parts by weight of solvent, and stir at 100-500 rpm for 12-36 h at room temperature to obtain alkali lignin polymer.

[0009] Take 4-20 parts by weight of the dried alkali lignin polymer and add it to a flask. Add 1-10 parts by weight of methacrylic acid, followed by 0.01-0.1 parts by weight of azobisisobutyronitrile, 1-10 parts by weight of methyl methacrylate, and 50-200 parts by weight of N,N-dimethylformamide. React at 50-70℃ for 3-8 hours. Then add 40-150 parts by weight of pure water and stir at 100-500 rpm. After 12 hours, filter the reaction product mixture through a 0.05μm-0.45μm filter membrane. Dry the filtered product in an oven to obtain bio-based microspheres.

[0010] (2) Treatment of wastewater from chromium-containing aluminum profiles:

[0011] Take 500-1000 parts by weight of chromium-containing aluminum profile wastewater from the equalization tank of the wastewater treatment system of an aluminum profile enterprise and put it into a beaker. Add hydrochloric acid dropwise to adjust the pH value to 2-5. Add 0.2-1 parts by weight of bio-based microspheres, stir rapidly at 150-300 r / min for 5-10 min, then stir slowly at 50-90 r / min for 10-30 min, let stand for 20 min, and centrifuge to obtain chromium-immobilized aluminum profile sludge.

[0012] (3) Calcination of chromium-immobilized aluminum profile sludge:

[0013] Chromium-immobilized aluminum profile sludge was placed in an oven and dried at 50-100℃ for 48 hours. After cooling, it was ground and sieved, and the sludge was pressed into cylinders. The samples were then placed in an oven and dried at 40-60℃ for 5 hours, and then placed in a muffle furnace. The temperature was increased from room temperature to 600-900℃ at a rate of 10℃ / min and held for 3 hours. Subsequently, the temperature was increased to 900-1500℃ at a rate of 5℃ / min and held for 3 hours. After cooling to room temperature, calcined aluminum profile sludge was obtained.

[0014] (4) Activation of sludge from calcined aluminum profiles:

[0015] Take a sample of calcined aluminum profile sludge and place it in a beaker. Use a vortex shaker to shake for 10-30 minutes to obtain activated aluminum profile sludge.

[0016] The solvent in step (1) is any one or a mixture of acetonitrile, tetrahydrofuran, and N,N-dimethylformamide.

[0017] Bio-based microspheres were prepared according to the above method.

[0018] Activated aluminum profile sludge prepared according to the above preparation method.

[0019] The prepared activated aluminum profile sludge can be applied to the field of wastewater adsorption.

[0020] The method for resource utilization of activated aluminum profile sludge involves adding an appropriate amount of activated aluminum profile sludge into the wastewater according to the degree of pollution, until the maximum adsorption capacity is reached.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. This invention first uses bio-based microspheres to treat chromium-containing aluminum profile wastewater, simultaneously immobilizing chromium in different valence states to form chromium-immobilized aluminum profile sludge. Then, activated aluminum profile sludge is obtained through calcination and vibration. The activated aluminum profile sludge can be used for pollutant adsorption in wastewater, realizing the resource utilization of chromium-containing aluminum profile wastewater.

[0023] 2. This invention utilizes alkali lignin to prepare bio-based microspheres. These microspheres contain a large number of carboxyl groups, and the selected raw materials exhibit strong reactivity, preventing the formation of other highly volatile small molecules such as acids that could affect subsequent performance. Furthermore, they possess self-aggregation and flocculation effects, enabling multi-effect treatment of chromium-containing aluminum profile wastewater. The carboxyl groups adsorb chromium (III) and chromium (VI) from the wastewater, achieving the first fixation. The microspheres then aggregate through self-aggregation, achieving a second fixation. Finally, the microspheres flocculate other pollutants in the wastewater, forming chromium-immobilized aluminum profile sludge—the third fixation. Finally, the alumina crystals formed by calcination achieve a fourth fixation.

[0024] 3. In the process of calcining chromium-immobilized aluminum profile sludge of this invention, chromium adsorbed on the surface of bio-based microspheres forms chromium oxide protective microspheres. Simultaneously, aluminum, the main component of the sludge, forms alumina. The calcined aluminum profile sludge is activated by vibration, loosening its structure and creating more pores, exposing active sites such as carbonyl groups within the bio-based microspheres. The presence of these active sites, alumina, and the pore structure of the sludge makes the activated aluminum profile sludge a highly promising adsorbent, suitable for adsorbing wastewater such as dye wastewater. Attached Figure Description

[0025] Figure 1 This is a scanning electron microscope image of a cross-section of activated aluminum profile sludge from Embodiment 1 of the present invention.

[0026] Figure 2The results of the chromium leaching toxicity test on the activated aluminum profile of this invention (- indicates no detection) are shown.

[0027] Figure 3 The adsorption results of methylene blue on sludge in this invention.

[0028] Figure 4 The adsorption results of Activated Red 2 by the sludge in this invention. Detailed Implementation

[0029] The present invention will be specifically described below through embodiments, which are only used to further illustrate the invention and should not be construed as limiting the scope of protection of the invention. It should be understood that after reading the contents of this invention, those skilled in the art will be able to make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0030] Example 1

[0031] (1) Synthesis of bio-based microspheres:

[0032] Take 5g of alkali lignin and 3g of isocyanate methacrylate in a flask, add 30mL of tetrahydrofuran, and stir at 100rpm for 24h at room temperature to obtain alkali lignin polymer.

[0033] 4g of dried alkali lignin polymer was added to a flask, followed by 2g of methacrylic acid, then 0.05g of azobisisobutyronitrile, 2g of methyl methacrylate, and 50mL of N,N-dimethylformamide. The mixture was reacted at 60℃ for 3h, then 50mL of pure water was added and stirred at 200rpm. After 12h, the reaction mixture was filtered through a 0.1μm filter membrane. The filtered product was then dried in an oven to obtain bio-based microspheres.

[0034] (2) Treatment of wastewater from chromium-containing aluminum profiles:

[0035] Take 500 mL of chromium-containing aluminum profile wastewater from the equalization tank of the aluminum profile enterprise's wastewater treatment system into a beaker, add hydrochloric acid to adjust the pH value to 3; add 0.4 g of bio-based microspheres, stir rapidly at 150 r / min for 10 min, then stir slowly at 50 r / min for 10 min, let stand for 20 min, and centrifuge to obtain chromium-immobilized aluminum profile sludge;

[0036] (3) Calcination of chromium-immobilized aluminum profile sludge:

[0037] Chromium-immobilized aluminum profile sludge was placed in an oven and dried at 50°C for 48 hours. After cooling, it was ground and sieved, then pressed into cylinders. The samples were then placed in an oven and dried at 60°C for 5 hours, and then placed in a muffle furnace. The temperature was increased from room temperature to 700°C at a rate of 10°C / min and held for 3 hours, followed by an increase to 1100°C at a rate of 5°C / min and held for 3 hours. After cooling to room temperature, calcined aluminum profile sludge was obtained.

[0038] (4) Activation of sludge from calcined aluminum profiles:

[0039] Take a sample of calcined aluminum profile sludge and place it in a beaker. Use a vortex shaker to shake for 20 minutes to obtain activated aluminum profile sludge.

[0040] Example 2

[0041] (1) Synthesis of bio-based microspheres:

[0042] Take 5g of alkali lignin and 5g of isocyanate methacrylate into a flask, add 50mL of tetrahydrofuran, and stir at 200rpm for 26h at room temperature to obtain alkali lignin polymer.

[0043] 7g of dried alkali lignin polymer was added to a flask, followed by 7g of methacrylic acid, then 0.05g of azobisisobutyronitrile, 7g of methyl methacrylate, and 50mL of N,N-dimethylformamide. The mixture was reacted at 50℃ for 6h, then 80mL of pure water was added and stirred at 200rpm. After 12h, the reaction mixture was filtered through a 0.1μm filter membrane. The filtered product was then dried in an oven to obtain bio-based microspheres.

[0044] (2) Treatment of wastewater from chromium-containing aluminum profiles:

[0045] Take 500 mL of chromium-containing aluminum profile wastewater from the equalization tank of the wastewater treatment system of the aluminum profile enterprise into a beaker, add hydrochloric acid to adjust the pH value to 3; add 0.3 g of bio-based microspheres, stir rapidly at 200 r / min for 10 min, then stir slowly at 60 r / min for 20 min, let stand for 20 min, and centrifuge to obtain chromium-immobilized aluminum profile sludge;

[0046] (3) Calcination of chromium-immobilized aluminum profile sludge:

[0047] Chromium-immobilized aluminum profile sludge was placed in an oven and dried at 80℃ for 48 hours. After cooling, it was ground and sieved, and the sludge was pressed into cylinders. The samples were then placed in an oven and dried at 50℃ for 5 hours, and then placed in a muffle furnace. The temperature was increased from room temperature to 700℃ at a rate of 10℃ / min and held for 3 hours, followed by an increase to 1200℃ at a rate of 5℃ / min and held for 3 hours. After cooling to room temperature, calcined aluminum profile sludge was obtained.

[0048] (4) Activation of sludge from calcined aluminum profiles:

[0049] Take a sample of calcined aluminum profile sludge and place it in a beaker. Use a vortex shaker to shake for 15 minutes to obtain activated aluminum profile sludge.

[0050] Example 3

[0051] (1) Synthesis of bio-based microspheres:

[0052] Take 10g of alkali lignin and 8g of isocyanate methacrylate in a flask, add 50mL of tetrahydrofuran, and stir at 200rpm for 36h at room temperature to obtain alkali lignin polymer.

[0053] 15g of dried alkali lignin polymer was added to a flask, followed by 8g of methacrylic acid, then 0.08g of azobisisobutyronitrile, 8g of methyl methacrylate, and 150mL of N,N-dimethylformamide. The mixture was reacted at 70℃ for 3h, then 100mL of pure water was added and stirred at 200rpm. After 12h, the reaction mixture was filtered through a 0.1μm filter membrane. The filtered product was then dried in an oven to obtain bio-based microspheres.

[0054] (2) Treatment of wastewater from chromium-containing aluminum profiles:

[0055] Take 1000mL of chromium-containing aluminum profile wastewater from the equalization tank of the wastewater treatment system of the aluminum profile enterprise into a beaker, add hydrochloric acid to adjust the pH value to 4; add 0.8g of bio-based microspheres, stir rapidly at 300r / min for 5min, then stir slowly at 80r / min for 30min, let stand for 20min, and centrifuge to obtain chromium-immobilized aluminum profile sludge;

[0056] (3) Calcination of chromium-immobilized aluminum profile sludge:

[0057] Chromium-immobilized aluminum profile sludge was placed in an oven and dried at 100℃ for 48 hours. After cooling, it was ground and sieved, and the sludge was pressed into cylinders. The samples were then placed in an oven and dried at 50℃ for 5 hours, and then placed in a muffle furnace. The temperature was increased from room temperature to 900℃ at a rate of 10℃ / min and held for 3 hours, followed by an increase to 1200℃ at a rate of 5℃ / min and held for 3 hours. After cooling to room temperature, calcined aluminum profile sludge was obtained.

[0058] (4) Activation of sludge from calcined aluminum profiles:

[0059] Take a sample of calcined aluminum profile sludge and place it in a beaker. Use a vortex shaker to shake for 30 minutes to obtain activated aluminum profile sludge.

[0060] Example 4

[0061] (1) Synthesis of bio-based microspheres:

[0062] Take 5g of alkali lignin and 3g of isocyanate methacrylate in a flask, add 40mL of tetrahydrofuran, and stir at 400rpm for 24h at room temperature to obtain alkali lignin polymer.

[0063] 5g of dried alkali lignin polymer was added to a flask, followed by 5g of methacrylic acid, then 0.03g of azobisisobutyronitrile, 5g of methyl methacrylate, and 100mL of N,N-dimethylformamide. The mixture was reacted at 50℃ for 7h, then 80mL of pure water was added and stirred at 300rpm. After 12h, the reaction mixture was filtered through a 0.05μm filter membrane. The filtered product was then dried in an oven to obtain bio-based microspheres.

[0064] (2) Treatment of wastewater from chromium-containing aluminum profiles:

[0065] Take 1000mL of chromium-containing aluminum profile wastewater from the equalization tank of the aluminum profile enterprise's wastewater treatment system into a beaker, add hydrochloric acid to adjust the pH value to 3; add 0.5g of bio-based microspheres, stir rapidly at 150r / min for 10min, then stir slowly at 70r / min for 20min, let stand for 20min, centrifuge to obtain chromium-immobilized aluminum profile sludge;

[0066] (3) Calcination of chromium-immobilized aluminum profile sludge:

[0067] Chromium-immobilized aluminum profile sludge was placed in an oven and dried at 80℃ for 48 hours. After cooling, it was ground and sieved, and the sludge was pressed into cylinders. The samples were then placed in an oven and dried at 50℃ for 5 hours, and then placed in a muffle furnace. The temperature was increased from room temperature to 600℃ at a rate of 10℃ / min and held for 3 hours, followed by an increase to 1000℃ at a rate of 5℃ / min and held for 3 hours. After cooling to room temperature, calcined aluminum profile sludge was obtained.

[0068] (4) Activation of sludge from calcined aluminum profiles:

[0069] Take a sample of calcined aluminum profile sludge and place it in a beaker. Use a vortex shaker to shake for 20 minutes to obtain activated aluminum profile sludge.

[0070] Example 5

[0071] (1) Synthesis of bio-based microspheres:

[0072] Take 15g of alkali lignin and 10g of isocyanate methacrylate in a flask, add 80mL of tetrahydrofuran, and stir at 400rpm for 24h at room temperature to obtain alkali lignin polymer.

[0073] 20g of dried alkali lignin polymer was added to a flask, followed by 10g of methacrylic acid, then 0.1g of azobisisobutyronitrile, 10g of methyl methacrylate, and 150mL of N,N-dimethylformamide. The mixture was reacted at 65℃ for 6h, then 100mL of pure water was added and stirred at 300rpm. After 12h, the mixture was filtered through a 0.1μm filter membrane. The filtered product was then dried in an oven to obtain bio-based microspheres.

[0074] (2) Treatment of wastewater from chromium-containing aluminum profiles:

[0075] Take 1000 mL of chromium-containing aluminum profile wastewater from the equalization tank of the wastewater treatment system of the aluminum profile enterprise into a beaker, add hydrochloric acid to adjust the pH value to 4; add 0.8 g of bio-based microspheres, stir rapidly at 300 r / min for 10 min, then stir slowly at 90 r / min for 20 min, let stand for 20 min, and centrifuge to obtain chromium-immobilized aluminum profile sludge;

[0076] (3) Calcination of chromium-immobilized aluminum profile sludge:

[0077] Chromium-immobilized aluminum profile sludge was placed in an oven and dried at 90℃ for 48 hours. After cooling, it was ground and sieved, and the sludge was pressed into cylinders. The samples were then placed in an oven and dried at 60℃ for 5 hours, and then placed in a muffle furnace. The temperature was increased from room temperature to 800℃ at a rate of 10℃ / min and held for 3 hours, followed by an increase to 1200℃ at a rate of 5℃ / min and held for 3 hours. After cooling to room temperature, calcined aluminum profile sludge was obtained.

[0078] (4) Activation of sludge from calcined aluminum profiles:

[0079] Take a sample of calcined aluminum profile sludge and place it in a beaker. Use a vortex shaker to shake for 15 minutes to obtain activated aluminum profile sludge.

[0080] Figure 1 It is evident that there are carbonized microspheres inside, and the surface has gray components, which is due to the presence of some alumina, which is conducive to the generation of adsorption active sites.

[0081] Table 1 shows that chromium has been effectively and stably adsorbed, and no chromium was detected. The simple procedure is to follow the national standard "Leaching Toxicity Methods for Solid Waste - Horizontal Shaking Method".

[0082] To verify the adsorption and fixation effect of bio-based microspheres on chromium in chromium-containing aluminum profile wastewater, the supernatant after centrifugation in step (2) of Example 2 was taken, and the chromium content in the water was determined by the diphenylcarbazide colorimetric method. The results showed that the chromium content in the supernatant after centrifugation in step (2) of Example 2 was 0.03 mg / L, which is lower than the maximum allowable concentration of chromium in surface water.

[0083] To investigate the fixation stability of chromium on activated aluminum profile sludge, 200 mL of water was added to a leaching bottle as the extraction solution, followed by 10 g of activated sludge. The mixture was shaken and extracted at 60 rpm in a shaker. 50 mL of the extract was collected at 18 h, 2 d, and 5 d. The extract was dried to obtain a sample. Approximately 0.1 g of the sample was accurately weighed, to a precision of 0.0001 g. The sample was placed in a 150 mL container, and 5-10 mL of nitric acid and 3-5 mL of perchloric acid were added. A watch glass was placed on top, and the mixture was heated until the sample was completely dissolved and evaporated until perchloric acid fumes were emitted (1-2 min). After cooling, the watch glass and the container walls were rinsed with water, and the mixture was transferred to a 100 mL volumetric flask and brought to volume. The chromium content was determined using inductively coupled plasma atomic emission spectrometry (ICP-AES). The test results are shown in the attached instruction manual. Figure 2 As shown, the chromium leaching toxicity was only 0.05 mg / L after 5 days, indicating that the activated aluminum profile sludge still had a stable effect on chromium fixation.

[0084] The adsorption capacity of calcined aluminum profile sludge and activated aluminum profile sludge on simulated dye wastewater was tested separately. Under room temperature and magnetic stirring, 20 mg of sample was added to 50 mL of 100 mg / L simulated dye wastewater. At 0, 5, 10, 20, 60, and 120 min, 4 mL of analytical sample was taken, centrifuged, and the concentration of the supernatant was measured using a UV-Vis spectrophotometer. The adsorption process was measured using the maximum absorbance corresponding to the characteristic absorption peak of the dye, calculated using the following mass balance equation:

[0085]

[0086] Where Qe (mg / g) is the amount of dye adsorbed per gram of adsorbent at equilibrium, C0 (mg / L) and Ct (mg / L) correspond to the initial concentration and the concentration of the dye at time interval t, respectively. V (L) is the solution volume, and m (g) is the mass of the adsorbent used.

[0087] The dye adsorption results are as shown in the attached instruction manual. Figure 2 Included with instruction manual Figure 3 As shown, the aluminum profile sludge activated by vibration exhibits significantly better adsorption effects on methylene blue and Reactive Red 2 dyes than the calcined aluminum profile sludge due to the exposure of active sites in its microspheres.

[0088] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A method for the treatment and resource utilization of chromium-containing aluminum profile wastewater based on bio-based microspheres, comprising the following steps: (1) Synthesis of bio-based microspheres: Take 2-15 parts by weight of alkali lignin and 2-10 parts by weight of isocyanate methacrylate in a flask, add 20-80 parts by weight of solvent, and stir at 100-500 rpm for 12-36 h at room temperature to obtain alkali lignin polymer. Take 4-20 parts by weight of the dried alkali lignin polymer and add it to a flask. Add 1-10 parts by weight of methacrylate, followed by 0.01-0.1 parts by weight of azobisisobutyronitrile, 1-10 parts by weight of methyl methacrylate, and 50-200 parts by weight of N,N-dimethylformamide. React at 50-70℃ for 3-8 hours. Then add 40-150 parts by weight of pure water and stir at 100-500 rpm. After 12 hours, filter the reaction product mixture through a 0.05µm-0.45µm filter membrane. Dry the filtered product in an oven to obtain bio-based microspheres. (2) Treatment of wastewater from chromium-containing aluminum profiles: Take 500-1000 parts by weight of chromium-containing aluminum profile wastewater from the equalization tank of the wastewater treatment system of an aluminum profile enterprise and put it into a beaker. Add hydrochloric acid dropwise to adjust the pH value to 2-5. Add 0.2-1 parts by weight of bio-based microspheres, stir rapidly at 150-300 r / min for 5-10 min, then stir slowly at 50-90 r / min for 10-30 min, let stand for 20 min, and centrifuge to obtain chromium-immobilized aluminum profile sludge. (3) Calcination of chromium-immobilized aluminum profile sludge: Chromium-immobilized aluminum profile sludge was placed in an oven and dried at 50-100℃ for 48 hours. After cooling, it was ground and sieved. The aluminum sludge was pressed into cylinders and then placed in an oven and dried at 40-60℃ for 5 hours. The sample was then placed in a muffle furnace and heated from room temperature to 600-900℃ at a rate of 10℃ / min and held for 3 hours. Subsequently, the temperature was increased to 900-1500℃ at a rate of 5℃ / min and held for 3 hours. After cooling to room temperature, calcined aluminum profile sludge was obtained. (4) Activation of sludge from calcined aluminum profiles: Take a sample of calcined aluminum profile sludge and place it in a beaker. Use a vortex shaker to shake for 10-30 minutes to obtain activated aluminum profile sludge.

2. The method for wastewater treatment and resource utilization of chromium-containing aluminum profiles based on bio-based microspheres according to claim 1, characterized in that: The solvent in step (1) is any one or a mixture of acetonitrile, tetrahydrofuran, and N,N-dimethylformamide.

3. The method for wastewater treatment and resource utilization of chromium-containing aluminum profiles based on bio-based microspheres according to claim 1, characterized in that: The prepared activated aluminum profile sludge can be applied to the field of wastewater adsorption.

4. The method for treating and utilizing wastewater from chromium-containing aluminum profiles based on bio-based microspheres according to claim 1, characterized in that: The method for resource utilization of activated aluminum profile sludge involves adding an appropriate amount of activated aluminum profile sludge into the wastewater according to the degree of pollution, until the maximum adsorption capacity is reached.

5. A bio-based microsphere prepared by the method according to claim 1.

6. An activated aluminum profile sludge prepared by the preparation method according to claim 1.

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