Treatment method of aluminum profile production sewage

Abstract

The invention discloses a treatment method of aluminum profile production sewage, which treats the aluminum profile production sewage step by step through reasonable process design and processes of pH regulation, grating separation, flocculent precipitation, adsorption, secondary flocculation and activated carbon fine treatment, and the final effluent quality can meet the aluminum profile production reuse standard. And cyclic utilization of water resources is realized. Wherein after chitosan, polyacrylamide and potassium sulfate are compounded, metal ions can be effectively captured through chelation, efficient flocculation bridging, coagulation accelerating and mutual synergistic effects, formation of a flocculating constituent with certain strength is accelerated, a better flocculation effect is achieved, and the cost is low; kaolin and porous silicon carbide are used as adsorption carriers, hexadecyl trimethyl ammonium bromide is introduced, adsorption is modified and enhanced, sodium polyacrylate and silica sol promote component dispersion and bonding, and the adsorbent with the mechanical property meeting the use requirement is prepared and has the excellent adsorption effect.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and more specifically, to a method for treating wastewater from aluminum profile production. Background Technology

[0002] Aluminum profile production is an important part of my country's non-ferrous metals industry, and its production process generates a large amount of industrial wastewater with complex composition and high pollutant concentrations. This type of industrial wastewater mainly originates from processes such as degreasing, alkaline etching, pickling (neutralization), oxidation, coloring, and sealing of aluminum profile surfaces. The wastewater generated from these processes mainly contains high concentrations of heavy metal ions, fluorides, and suspended solids. Heavy metal ions in the wastewater are biotoxic and can accumulate in the environment; fluorides exceeding a certain concentration can cause serious harm to animals, plants, and humans; and suspended solids can disrupt the ecological balance of aquatic bodies.

[0003] There are also many existing technologies for treating wastewater from aluminum profile production. For example, Chinese patent application number CN201210539943.2 discloses a wastewater treatment method in the aluminum profile oxidation process. The treatment method includes steps for treating acidic / alkaline wastewater and wastewater containing heavy metals. Its features are: 1) For acidic / alkaline wastewater without heavy metals, coagulation sedimentation, filtration, ultrafiltration, and nanofiltration are performed. The treated reclaimed water is directly reused in the production line, and the generated sludge is dewatered and then comprehensively utilized. 2) Wastewater containing heavy metals is treated separately through a recovery device. The recovered heavy metals are directly returned to the coloring tank and sealing tank, and the treated fresh water is directly added to the washing tank. For example, Chinese patent application CN201710226610.7 discloses a method for treating industrial wastewater from aluminum alloy production. It innovatively proposes using acid- and alkali-washed seashells as a culture medium for magnetotactic bacteria and a carrier for graphene sheets, providing a carrier for adsorbing heavy metals. After mixing the carrier with the industrial wastewater from aluminum alloy production, the heavy metals are fully adsorbed and then separated by a magnetic field. Experimental comparisons show that this method is more efficient than similar treatment methods without a carrier. Another example is Chinese patent application CN201410106805.4, which discloses a wastewater treatment method, particularly a method for treating wastewater from aluminum profile modification. It involves adding substance A and substance B to wastewater obtained from aluminum profile modification treatment at a mass ratio of 1:1-4. Substance A is one or both of magnesium nitrate and magnesium sulfate; substance B is one or more of calcium hydroxide, calcium oxide, or calcium sulfite. The pH of the wastewater is adjusted to 7.8-8.2, and the reaction is carried out under stirring for 20-40 minutes. Polyacrylamide is added to the reaction solution, followed by solid-liquid separation to obtain wastewater that meets discharge standards. This invention provides safe and environmentally friendly production and thorough wastewater treatment. However, existing technologies still suffer from problems such as insufficient targeting of the added flocculant, resulting in poor flocculation effects; and the inability to reuse the precipitant, leading to high treatment costs. Summary of the Invention

[0004] In view of this, in order to solve one of the above-mentioned technical problems, the present invention provides a method for treating wastewater from aluminum profile production, the specific technical solution of which is as follows:

[0005] A method for treating wastewater from aluminum profile production, the method comprising the following steps:

[0006] S1. Discharge the wastewater from aluminum profile production into the equalization tank and adjust the pH value to 6.0-8.0 to obtain primary wastewater;

[0007] S2. The primary wastewater is separated into large particles by a grid separation method and then discharged into treatment tank A. Flocculant is added, the stirring device in treatment tank A is started, and after stirring under the first stirring condition, it is allowed to settle and the upper liquid is discharged to obtain secondary wastewater.

[0008] S3. Discharge the secondary wastewater into treatment tank B, add adsorbent to treatment tank B, let it stand for treatment, and then discharge the upper liquid to obtain tertiary wastewater.

[0009] S4. Discharge the tertiary wastewater into treatment tank C, add flocculant, then start the stirring device in treatment tank C, stir under the second stirring condition, then let it settle, and discharge the upper liquid to obtain tertiary wastewater.

[0010] S5. The fourth-level wastewater is treated with activated carbon and then discharged into a recycling tank. After passing the test, it is reused according to the water demand for aluminum profile production.

[0011] The structure of the treatment tank A includes: treatment tank A (10) and a stirring device that is disposed in the treatment tank A (10) and can move up and down; the stirring device includes a stirring structure, a lifting structure and a lifting plate (20) connecting the stirring structure and the lifting structure, and the flocculation effect is promoted by controlling the rotation speed of the stirring structure and its lifting in the treatment tank A (10).

[0012] Preferably, the flocculant is prepared by adding chitosan to an acetic acid solution with a mass percentage concentration of 1% to 2%, then adding polyacrylamide and potassium sulfate, stirring at 50°C to 60°C for 1 to 3 hours, and then drying and grinding to obtain the flocculant.

[0013] Preferably, the weight ratio of chitosan, acetic acid solution, polyacrylamide and potassium sulfate is (1-5):(10-15):(3-7):(1-2).

[0014] Preferably, in step S2, the ratio of the amount of flocculant added to the primary wastewater is (100-500) g / m³. 3 .

[0015] Preferably, in step S2, the first stirring conditions are: the rotation speed in the first stage is 300 r / min to 500 r / min, and the stirring time is 5 min to 10 min; the rotation speed in the second stage is 20 r / min to 50 r / min, and the stirring time is 20 min to 30 min.

[0016] Preferably, the adsorbent is prepared by adding kaolin, porous silicon carbide and sodium polyacrylate to an appropriate amount of water, stirring at a speed of 50 r / min to 100 r / min for 1 h to 3 h, then adding hexadecyltrimethylammonium bromide and silica sol, stirring for another 20 min to 30 min, granulating, drying and calcining to obtain the adsorbent.

[0017] Preferably, the ratio of the amount of adsorbent added to the secondary wastewater is (150-500) g / Lm³. 3 .

[0018] Preferably, the weight ratio of kaolin, porous silicon carbide, sodium polyacrylate, water, hexadecyltrimethylammonium bromide and silica sol is (5-15):(7-9):(1-7):(15-30):(2-5):(1-5).

[0019] Preferably, in step S4, the ratio of the amount of flocculant added to the tertiary wastewater is (20-100) g / Lm³. 3 .

[0020] Preferably, in step S4, the second stirring conditions are: in the first stage, the stirring speed is 50 r / min to 100 r / min and the stirring time is 3 min to 5 min; in the second stage, the stirring speed is 20 r / min to 50 r / min and the stirring time is 10 min to 15 min.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. This invention, through a reasonable process design, uses a multi-stage combined process of "pH adjustment → grid separation → flocculation sedimentation → adsorption → secondary flocculation → activated carbon purification" to treat wastewater from aluminum profile production in stages. The final effluent quality can meet the standards for reuse in aluminum profile production, thus realizing the recycling of water resources.

[0023] 2. This invention adds a specially formulated flocculant, which combines chitosan, polyacrylamide, and potassium sulfate. Through chelation, efficient flocculation bridging, and coagulation-promoting effects, they work synergistically to effectively capture metal ions and accelerate the formation of flocs with a certain strength, resulting in better flocculation effects at a lower cost.

[0024] 3. This invention adds a specially formulated adsorbent, using kaolin and porous silicon carbide as adsorption carriers, and introduces hexadecyltrimethylammonium bromide to modify and enhance adsorption. Sodium polyacrylate and silica sol promote the dispersion and bonding of components, thus preparing an adsorbent with mechanical properties that meet the requirements for use and with excellent adsorption effect.

[0025] 4. This invention, by adding a stirring device to treatment tanks A and C and controlling the stirring speed, helps to improve the flocculation effect, achieving a certain degree of efficiency improvement and cost reduction. Furthermore, when flocculation and sedimentation occur, controlling the up-and-down movement of the stirring structure provides a more effective stirring effect and makes it easier for the sediment to be discharged from the bottom of the treatment tank. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the stirring device structure of treatment tank A in a method for treating wastewater from aluminum profile production according to Embodiment 1 of the present invention. Figure 1 ;

[0027] Figure 2 This is a schematic diagram of the stirring device structure of treatment tank A in a method for treating wastewater from aluminum profile production according to Embodiment 1 of the present invention. Figure 2 ;

[0028] Figure 3 This is a schematic flowchart of a method for treating wastewater from aluminum profile production according to Embodiment 1 of the present invention.

[0029] Attached symbols

[0030] 10. Sedimentation tank; 20. Lifting plate; 31. First motor; 32. First chain; 33. Second motor; 34. Second chain; 35. Driven sprocket; 40. Agitator shaft; 41. Agitator rod; 51. Third motor; 52. Cable; 53. Winding wheel. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0032] A method for treating wastewater from aluminum profile production according to one embodiment of the present invention includes the following steps:

[0033] S1. Discharge the wastewater from aluminum profile production into the equalization tank and adjust the pH value to 6.0-8.0 to obtain primary wastewater;

[0034] S2. The primary wastewater is separated into large particles by a grid separation method and then discharged into treatment tank A. Flocculant is added, the stirring device in treatment tank A is started, and after stirring under the first stirring condition, it is allowed to settle and the upper liquid is discharged to obtain secondary wastewater.

[0035] S3. Discharge the secondary wastewater into treatment tank B, add adsorbent to treatment tank B, let it stand for treatment, and then discharge the upper liquid to obtain tertiary wastewater.

[0036] S4. Discharge the tertiary wastewater into treatment tank C, add flocculant, then start the stirring device in treatment tank C, stir under the second stirring condition, then let it settle, and discharge the upper liquid to obtain tertiary wastewater.

[0037] S5. The fourth-level wastewater is treated with activated carbon and then discharged into a recycling tank. After passing the test, it is reused according to the water demand for aluminum profile production.

[0038] The structure of the treatment tank A includes: a treatment tank A10 and a stirring device disposed in the treatment tank A10 and capable of moving up and down; the stirring device includes a stirring structure, a lifting structure and a lifting plate 20 connecting the stirring structure and the lifting structure, and the flocculation effect is promoted by controlling the rotation speed of the stirring structure and its lifting and lowering in the treatment tank A10.

[0039] In one embodiment, the stirring structure includes a first motor 31, a first chain 32, a second motor 33, a second chain 34, a driven wheel 35, a stirring shaft 40, and multiple stirring rods 41. The first motor 31 is mounted on the lifting plate 20 and connected to one end of the first chain 32. The other end of the first chain 32 is connected to the driven wheel 35 mounted on one end of the stirring shaft 40. One end of the second chain 34 is connected to the auxiliary support 33, and the other end of the second chain 34 is connected to the driven wheel 35 mounted on the other end of the stirring shaft 40. When the first motor 31 is started, the first chain 32, the second chain 34, and the driven wheel 35 drive the stirring shaft 40 and the stirring rods 41, thereby achieving stirring within the stirring tank A10 and effectively controlling the stirring speed.

[0040] In one embodiment, the lifting structure includes a third motor 51, a cable 52, and a winding wheel 53. The third motor 51 is connected to the winding wheel 53, the winding wheel 53 is connected to one end of the cable 52, and the other end of the cable 52 is connected to the lifting plate 20. When the third motor 51 is started, the lifting plate 20 is driven by controlling the extension and retraction of the cable 52. The lifting plate 20 drives the stirring structure, thereby realizing the up and down movement of the stirring structure in the treatment tank A. This not only helps to promote flocculation, but also, when the stirring is turned off, raises the stirring structure to a higher position, which also helps to drain the sediment from the bottom of the treatment tank A10 and clean the treatment tank A.

[0041] In one embodiment, the processing pool C is the same as the processing pool A, and will not be described again here. Furthermore, this application... Figure 1 as well as Figure 2 For the purpose of illustrating the technical solution of this application, the specific circuit settings are not protected. The structure is feasible and the solution is clear. Therefore, the specific circuit design will not be described in detail.

[0042] In one embodiment, the flocculant is prepared by adding chitosan to an acetic acid solution with a mass percentage concentration of 1% to 2%, then adding polyacrylamide and potassium sulfate, stirring at 50°C to 60°C for 1 to 3 hours, and then drying and grinding to obtain the flocculant.

[0043] In one embodiment, the weight ratio of chitosan, acetic acid solution, polyacrylamide and potassium sulfate is (1-5):(10-15):(3-7):(1-2).

[0044] In one embodiment, in step S2, the ratio of the amount of flocculant added to the primary wastewater is (100-500) g / m³. 3 .

[0045] In one embodiment, in step S2, the first stirring conditions are: the rotation speed of the first stage is 300 r / min to 500 r / min, and the stirring time is 5 min to 10 min; the rotation speed of the second stage is 20 r / min to 50 r / min, and the stirring time is 20 min to 30 min.

[0046] In one embodiment, in step S2, the settling time is 1h to 3h.

[0047] In one embodiment, the adsorbent is prepared by adding kaolin, porous silicon carbide and sodium polyacrylate to an appropriate amount of water, stirring at a speed of 50 r / min to 100 r / min for 1 h to 3 h, then adding hexadecyltrimethylammonium bromide and silica sol, stirring for another 20 min to 30 min, granulating, drying and calcining to obtain the adsorbent.

[0048] In one embodiment, the ratio of the amount of adsorbent added to the secondary wastewater is (150-500) g / Lm³. 3 .

[0049] In one embodiment, the weight ratio of kaolin, porous silicon carbide, sodium polyacrylate, water, hexadecyltrimethylammonium bromide and silica sol is (5-15):(7-9):(1-7):(15-30):(2-5):(1-5).

[0050] In one embodiment, granulation yields spherical particles with an average particle size of 1 mm to 5 mm.

[0051] In one embodiment, the drying temperature is 65°C to 90°C, and the drying time is 3 hours to 5 hours.

[0052] In one embodiment, the calcination process includes a first stage and a second stage. The first stage involves heating the temperature to 300°C to 350°C at a heating rate of 2°C / min to 5°C / min and holding it at that temperature for 1 hour to 3 hours. The second stage involves heating the temperature to 500°C to 600°C at a heating rate of 8°C / min to 10°C / min and holding it at that temperature for 1 hour to 3 hours.

[0053] In one embodiment, in step S3, the settling time is 5h to 24h.

[0054] In one embodiment, in step S4, the ratio of the amount of flocculant added to the tertiary wastewater is (20-100) g / Lm³. 3 .

[0055] In one embodiment, in step S4, the second stirring conditions are: in the first stage, the stirring speed is 50 r / min to 100 r / min and the stirring time is 3 min to 5 min; in the second stage, the stirring speed is 20 r / min to 50 r / min and the stirring time is 10 min to 15 min.

[0056] In one embodiment, in step S4, the settling time is 1h to 5h.

[0057] In one embodiment, in step S5, the ratio of activated carbon added to the tertiary wastewater is (100-500) g / m³. 3 .

[0058] In one embodiment, in step S5, the activated carbon treatment time is 1h to 10h.

[0059] In one embodiment, the surface of the stirring device is coated with a corrosion-resistant coating.

[0060] The above-mentioned scheme, through reasonable design, can achieve significant overall treatment results, and the treated wastewater can meet the requirements for recycling.

[0061] The embodiments of the present invention will be described in detail below with reference to specific examples. It should be noted that both treatment tank A and treatment tank C in embodiments 1-3 are equipped with stirring devices, which have the same structure. The structure in treatment tank A will be used as the basis for the description, and will not be described in detail again in the embodiments.

[0062] The structure of treatment tank A includes: treatment tank A10 and a stirring device disposed in treatment tank A10 and capable of moving up and down; the stirring device includes a stirring structure, a lifting structure and a lifting plate 20 connecting the stirring structure and the lifting structure, and the flocculation effect is promoted by controlling the rotation speed of the stirring structure and its lifting and lowering in treatment tank A10.

[0063] The stirring structure includes a first motor 31, a first chain 32, a second motor 33, a second chain 34, a driven sprocket 35, a stirring shaft 40, and multiple stirring rods 41. The first motor 31 and the second motor 33 are both mounted on a lifting plate 20 and connected to one end of the first chain 32 and one end of the second chain 34, respectively. The other end of the first chain 32 is connected to the driven sprocket 35 mounted on one end of the stirring shaft 40. One end of the second chain 34 is connected to the second motor 33, and the other end of the second chain 34 is connected to the driven sprocket 35 mounted on the other end of the stirring shaft 40. When the first motor 31 and the second motor 33 are started, the first chain 32, the second chain 34, and the driven sprocket 35 drive the stirring shaft 40 and the stirring rods 41, realizing stirring within the stirring tank A10 and effectively controlling the stirring speed.

[0064] The lifting structure includes a third motor 51, a cable 52, and a winding wheel 53. The third motor 51 is connected to the winding wheel 53, and the winding wheel 53 is connected to one end of the cable 52. The other end of the cable 52 is connected to the lifting plate 20. When the third motor 51 is started, the lifting plate 20 is driven by controlling the extension and retraction of the cable 52. The lifting plate 20 drives the stirring structure, thereby realizing the up and down movement of the stirring structure in the treatment tank A. This not only helps to promote flocculation, but also, when the stirring is turned off, raises the stirring structure to a higher position, which also helps to drain the sediment from the bottom of the treatment tank A10 and clean the treatment tank A.

[0065] Example 1:

[0066] A method for treating wastewater from aluminum profile production, the method comprising the following steps:

[0067] S1. Discharge the wastewater from aluminum profile production into the equalization tank and adjust the pH value to 7.0 to obtain primary wastewater;

[0068] S2. The primary wastewater is separated into large particles using a bar screen separation method, and then discharged into treatment tank A, with 300g / m³ added. 3 Flocculant, start the stirring device in the treatment tank A, stir at a speed of 300 r / min for 5 min in the first stage, then stir at a speed of 20 r / min for 25 min in the second stage, then let it stand and settle for 3 h, and discharge the upper liquid to obtain secondary wastewater;

[0069] The preparation method of the flocculant is as follows: 3 parts by weight of chitosan are added to 10 parts by weight of 1% acetic acid solution, then 5 parts by weight of polyacrylamide and 1 part by weight of potassium sulfate are added, and the mixture is stirred at 60°C for 2 hours, then dried and ground to obtain the flocculant.

[0070] S3. Discharge the secondary wastewater into treatment tank B, and add 400g / m³ of wastewater to treatment tank B. 3 Adsorbent, let stand for 20 hours, discharge the upper liquid to obtain tertiary wastewater;

[0071] The adsorbent is prepared as follows: 12 parts by weight of kaolin, 7 parts by weight of porous silicon carbide, and 5 parts by weight of sodium polyacrylate are added to 20 parts by weight of water and stirred at 100 r / min for 2 h. Then, 3 parts by weight of hexadecyltrimethylammonium bromide and 5 parts by weight of silica sol are added, and stirring is continued for 25 min. Spherical particles with an average particle size of 5 mm are obtained by granulation. The particles are dried at 70°C for 4 h and then calcined. The calcination process includes a first stage and a second stage. The first stage process is: heating to 300°C at a heating rate of 5°C / min and holding at that temperature for 2 h. The second stage process is: heating to 500°C at a heating rate of 10°C / min and holding at that temperature for 1 h to obtain the adsorbent.

[0072] S4. Discharge the tertiary wastewater into treatment tank C, and add 50g / m³ of water. 3 The flocculant in step S2 is then used to start the stirring device in the treatment tank C. In the first stage, the stirring speed is 50 r / min for 4 min, and in the second stage, the stirring speed is 20 r / min for 10 min. After settling for 3 h, the upper liquid is discharged to obtain the fourth-grade wastewater.

[0073] S5. Add 350g / m³ to the fourth-level wastewater. 3 After 2 hours of activated carbon treatment, the water is discharged into a recycling pool. Once it passes the test, it can be reused according to the water requirements for aluminum profile production.

[0074] Example 2:

[0075] A method for treating wastewater from aluminum profile production, the method comprising the following steps:

[0076] S1. Discharge the wastewater from aluminum profile production into the equalization tank and adjust the pH value to 7.0 to obtain primary wastewater;

[0077] S2. The primary wastewater is separated into large particles using a bar screen separation method, and then discharged into treatment tank A, with 350g / m³ added. 3 Flocculant, start the stirring device in the treatment tank A, stir at a speed of 300 r / min for 5 min in the first stage, then stir at a speed of 25 r / min for 20 min in the second stage, then let it stand and settle for 2 h, and discharge the upper liquid to obtain secondary wastewater;

[0078] The flocculant is prepared by adding 4 parts by weight of chitosan to 12 parts by weight of 1% acetic acid solution, then adding 6 parts by weight of polyacrylamide and 2 parts by weight of potassium sulfate, stirring at 55°C for 2 hours, and then drying and grinding to obtain the flocculant.

[0079] S3. Discharge the secondary wastewater into treatment tank B, and add 450g / m³ of wastewater to treatment tank B. 3 Adsorbent, let stand for 20 hours, discharge the upper liquid to obtain tertiary wastewater;

[0080] The adsorbent is prepared as follows: 15 parts by weight of kaolin, 8 parts by weight of porous silicon carbide, and 5 parts by weight of sodium polyacrylate are added to 20 parts by weight of water and stirred at 100 r / min for 2 h. Then, 3 parts by weight of hexadecyltrimethylammonium bromide and 5 parts by weight of silica sol are added and stirred for another 25 min. Spherical particles with an average particle size of 5 mm are obtained and dried at 70°C for 4 h. Calcination is then performed, including a first stage and a second stage. The first stage involves heating to 300°C at a heating rate of 4°C / min and holding for 2 h. The second stage involves heating to 500°C at a heating rate of 8°C / min and holding for 1 h to obtain the adsorbent.

[0081] S4. Discharge the tertiary wastewater into treatment tank C, and add 60g / m³ of water. 3 The flocculant in step S2 is then used to start the stirring device in the treatment tank C. In the first stage, the stirring speed is 50 r / min for 4 min, and in the second stage, the stirring speed is 20 r / min for 10 min. After settling for 3 h, the upper liquid is discharged to obtain the fourth-grade wastewater.

[0082] S5. Add 350g / m³ to the fourth-level wastewater. 3 After 2 hours of activated carbon treatment, the water is discharged into a recycling pool. Once it passes the test, it can be reused according to the water requirements for aluminum profile production.

[0083] Example 3:

[0084] A method for treating wastewater from aluminum profile production, the method comprising the following steps:

[0085] S1. Discharge the wastewater from aluminum profile production into the equalization tank and adjust the pH value to 7.0 to obtain primary wastewater;

[0086] S2. The primary wastewater is separated into large particles using a bar screen separation method, and then discharged into treatment tank A, with 400g / m³ added. 3 Flocculant, start the stirring device in the treatment tank A, stir at a speed of 300 r / min for 5 min in the first stage, then stir at a speed of 20 r / min for 25 min in the second stage, then let it stand and settle for 2 h, and discharge the upper liquid to obtain secondary wastewater;

[0087] The preparation method of the flocculant is as follows: 5 parts by weight of chitosan are added to 15 parts by weight of 1% acetic acid solution, then 7 parts by weight of polyacrylamide and 2 parts by weight of potassium sulfate are added, and the mixture is stirred at 60°C for 2 hours, then dried and ground to obtain the flocculant.

[0088] S3. Discharge the secondary wastewater into treatment tank B, and add 400g / m³ of wastewater to treatment tank B. 3 Adsorbent, let stand for 20 hours, discharge the upper liquid to obtain tertiary wastewater;

[0089] The adsorbent is prepared as follows: 13 parts by weight of kaolin, 8 parts by weight of porous silicon carbide, and 6 parts by weight of sodium polyacrylate are added to 18 parts by weight of water and stirred at 100 r / min for 2 h. Then, 3 parts by weight of hexadecyltrimethylammonium bromide and 5 parts by weight of silica sol are added and stirred for another 25 min. Spherical particles with an average particle size of 5 mm are obtained and dried at 70°C for 3.5 h. Calcination is then performed, including a first stage and a second stage. The first stage involves heating to 300°C at a heating rate of 5°C / min and holding for 2 h. The second stage involves heating to 500°C at a heating rate of 8°C / min and holding for 1 h to obtain the adsorbent.

[0090] S4. Discharge the tertiary wastewater into treatment tank C, and add 60g / m³ of water. 3 The flocculant in step S2 is then used to start the stirring device in the treatment tank C. In the first stage, the stirring speed is 50 r / min for 4 min, and in the second stage, the stirring speed is 20 r / min for 10 min. After settling for 3 h, the upper liquid is discharged to obtain the fourth-grade wastewater.

[0091] S5. Add 350g / m³ to the fourth-level wastewater. 3 After 2 hours of activated carbon treatment, the water is discharged into a recycling pool. Once it passes the test, it can be reused according to the water requirements for aluminum profile production.

[0092] Comparative Example 1:

[0093] The difference between Comparative Example 1 and Example 3 is that the flocculant in Comparative Example 1 is a single polyacrylamide, while the rest is the same as in Example 3.

[0094] Comparative Example 2:

[0095] The difference between Comparative Example 2 and Example 3 is that the flocculant in Comparative Example 2 is a single chitosan, while the rest is the same as in Example 3.

[0096] Comparative Example 3:

[0097] The difference between Comparative Example 3 and Example 3 is that no flocculant was added in step S2 of Comparative Example 3, while the rest is the same as Example 3.

[0098] Comparative Example 4:

[0099] The difference between Comparative Example 4 and Example 3 is that porous silicon carbide was not added to the adsorbent in step S3 of Comparative Example 4, but the rest is the same as Example 3.

[0100] Comparative Example 5:

[0101] The difference between Comparative Example 5 and Example 3 is that the calcination process of the adsorbent used in step S3 of Comparative Example 5 is as follows: the temperature is increased to 550°C at a heating rate of 10°C / min, and held for 3 hours. Everything else is the same as in Example 3.

[0102] Comparative Example 6:

[0103] Compared with Example 3, Comparative Example 5 differs in that no adsorbent was added in step S3 of Comparative Example 6, while the rest is the same as Example 3.

[0104] Comparative Example 7:

[0105] The difference between Comparative Example 7 and Example 3 is that no flocculant was added in step S4 of Comparative Example 7, while the rest is the same as Example 3.

[0106] Comparative Example 8:

[0107] The difference between Comparative Example 8 and Example 3 is that the first stirring conditions in step S2 of Comparative Example 8 are: a rotation speed of 50 r / min and a time of 2 h. Everything else is the same as in Example 3.

[0108] Comparative Example 9:

[0109] The difference between Comparative Example 9 and Example 3 is that no stirring device is installed in the treatment tank A of Comparative Example 9, but otherwise it is the same as Example 3.

[0110] Comparative Example 10:

[0111] Compared with Example 3, Comparative Example 10 differs in that the stirring device in the treatment tank A of Comparative Example 10 is fixed at the bottom of the treatment tank A. After testing, it was found that a lot of flocculent sediment was deposited on the surface of the stirring device, which was not easy to clean and difficult to discharge. This made the overall sewage treatment process more complicated and the treatment effect was worse than that of Example 3. Therefore, after improving the structure of the stirring device, the effect described in Example 3 can be achieved.

[0112] The removal rate was calculated according to the treatment methods of Examples 1 to 3 and Comparative Examples 1 to 9. The removal rate for each item was (content before treatment - content after treatment) / content before treatment × 100%. The results are shown in Table 1 below.

[0113] Table 1: Removal Rate (%)

[0114]

[0115] As can be seen from the data analysis in Table 1, the present invention can significantly improve the wastewater treatment effect through reasonable process design and preparation of specific flocculants and adsorbents. As can be seen from Comparative Examples 1 to 3, the addition of a specific flocculant in step S2, with the chitosan and polyacrylamide components in the flocculant, can improve the treatment effect. In Comparative Example 4, the addition of porous silicon carbide, under the adsorption of porous kaolin, improves the formation of adsorbent particles and increases the number of adsorption sites, thereby playing a synergistic role. The different calcination process in Comparative Example 5 caused the adsorbent to collapse during the calcination process, resulting in a lower porosity than in Example 3, which affected its adsorption effect. In Comparative Example 6, no adsorbent was added, and in Comparative Example 7, no flocculant was added in step S4, resulting in a significant decrease in wastewater treatment effect. This indicates that the addition of appropriate adsorbents and flocculants in the process of this application makes the wastewater treatment effect more significant. In Comparative Example 8, the stirring conditions in treatment tank A were changed, and in Comparative Example 9, no stirring device was set up, resulting in a worse treatment effect than in Example 3. This indicates that under appropriate stirring conditions, the dispersion of flocculant in water can be accelerated, and the flocculant or flocs can be prevented from settling prematurely at the bottom of treatment tank A, which helps to improve the flocculation effect.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for treating wastewater from aluminum profile production, characterized in that, The processing method includes the following steps: S1. Discharge the wastewater from aluminum profile production into the equalization tank and adjust the pH value to 6.0-8.0 to obtain primary wastewater; S2. The primary wastewater is separated into large particles by a grid separation method and then discharged into treatment tank A. Flocculant is added, the stirring device in treatment tank A is started, and after stirring under the first stirring condition, it is allowed to settle and the upper liquid is discharged to obtain secondary wastewater. S3. Discharge the secondary wastewater into treatment tank B, add adsorbent to treatment tank B, let it stand for treatment, and then discharge the upper liquid to obtain tertiary wastewater. S4. Discharge the tertiary wastewater into treatment tank C, add flocculant, then start the stirring device in treatment tank C, stir under the second stirring condition, then let it settle, and discharge the upper liquid to obtain tertiary wastewater. S5. The fourth-level wastewater is treated with activated carbon and then discharged into a recycling tank. After passing the test, it is reused according to the water demand for aluminum profile production. The structure of the treatment tank A includes: treatment tank A (10) and a stirring device that is disposed in the treatment tank A (10) and can move up and down; the stirring device includes a stirring structure, a lifting structure and a lifting plate (20) connecting the stirring structure and the lifting structure, and the flocculation effect is promoted by controlling the rotation speed of the stirring structure and its lifting in the treatment tank A (10).

2. The processing method according to claim 1, characterized in that, The flocculant is prepared by adding chitosan to an acetic acid solution with a mass percentage concentration of 1% to 2%, then adding polyacrylamide and potassium sulfate, stirring at 50℃ to 60℃ for 1 to 3 hours, and then drying and grinding to obtain the flocculant.

3. The processing method according to claim 2, characterized in that, The weight ratio of chitosan, acetic acid solution, polyacrylamide and potassium sulfate is (1-5):(10-15):(3-7):(1-2).

4. The processing method according to claim 1, characterized in that, In step S2, the ratio of the amount of flocculant added to the primary wastewater is (100-500) g / m³. 3 .

5. The processing method according to claim 1, characterized in that, In step S2, the first stirring conditions are: the rotation speed in the first stage is 300 r / min to 500 r / min, and the stirring time is 5 min to 10 min; the rotation speed in the second stage is 20 r / min to 50 r / min, and the stirring time is 20 min to 30 min.

6. The processing method according to claim 1, characterized in that, The adsorbent is prepared by adding kaolin, porous silicon carbide and sodium polyacrylate to an appropriate amount of water, stirring at a speed of 50 r / min to 100 r / min for 1 h to 3 h, then adding hexadecyltrimethylammonium bromide and silica sol, stirring for another 20 min to 30 min, granulating, drying and calcining to obtain the adsorbent.

7. The processing method according to claim 6, characterized in that, The ratio of the amount of adsorbent added to the secondary wastewater is (150-500) g / L. 3 .

8. The processing method according to claim 6, characterized in that, The weight ratio of kaolin, porous silicon carbide, sodium polyacrylate, water, hexadecyltrimethylammonium bromide and silica sol is (5-15):(7-9):(1-7):(15-30):(2-5):(1-5).

9. The processing method according to claim 1, characterized in that, In step S4, the ratio of the amount of flocculant added to the tertiary wastewater is (20-100) g / Lm³. 3 .

10. The processing method according to claim 1, characterized in that, In step S4, the second stirring conditions are: in the first stage, the stirring speed is 50 r / min to 100 r / min and the stirring time is 3 min to 5 min; in the second stage, the stirring speed is 20 r / min to 50 r / min and the stirring time is 10 min to 15 min.

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