A method for treating wastewater from anodizing of photovoltaic aluminum profiles

Abstract

The present application relates to a kind of photovoltaic aluminum profile anodizing wastewater treatment methods, including the raw water is treated by acid-base neutralization, then is sent into electrostatic spinning tank, after filtration treatment, in turn is sent into cation exchange resin device and anion exchange resin.The method has less processing procedure, short cycle, can complete a batch of photovoltaic aluminum profile anodizing wastewater treatment in a day, processing efficiency is high, very suitable for centralized treatment of photovoltaic aluminum profile anodizing wastewater in industry, with good industrial application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, in particular to a method for treating photovoltaic aluminum profile anodizing wastewater. Background Art

[0002] Photovoltaic aluminum alloy anodizing wastewater is a special type of wastewater generated during the photovoltaic industry and aluminum alloy processing. It usually contains a variety of pollutants, including grease, surfactants, alkali, acid, heavy metal ions (such as nickel ions and tin ions), dyes, additives, and other trace pollutants. These pollutants come from various anodizing processes, such as degreasing, alkaline etching, neutralization, anodizing, dyeing, and sealing.

[0003] With the improvement of environmental awareness, the treatment of photovoltaic aluminum alloy anodizing wastewater has received more and more attention. At present, the treatment process of photovoltaic aluminum alloy anodizing wastewater mainly includes pretreatment, neutralization, coagulation and sedimentation, oxidation-reduction, biological treatment and deep treatment, as follows:

[0004] Pretreatment: Remove large suspended solids through grid filtration, sedimentation and other steps to reduce the burden of subsequent treatment.

[0005] Neutralization: Adjusting the pH of wastewater to neutral or near neutral for subsequent treatment. This step typically uses chemical reagents such as sulfuric acid or sodium hydroxide.

[0006] Coagulation and sedimentation: Add coagulants (such as polyaluminum chloride, ferrous sulfate, etc.) and flocculants (such as polyacrylamide) to the neutralized wastewater to make the fine suspended matter condense into larger particles, which are then removed by sedimentation.

[0007] Oxidation-reduction: For wastewater containing difficult-to-degrade organic matter such as dyes and additives, oxidation-reduction methods such as Fenton oxidation and ozone oxidation can be used for treatment to decompose the organic matter into harmless substances.

[0008] Biological treatment: After pretreatment and coagulation and sedimentation, wastewater can enter a biological treatment unit for further treatment. Biological treatment units typically include biological contact oxidation tanks and secondary sedimentation tanks, removing organic matter and nutrients from the wastewater through microbial metabolism.

[0009] Advanced treatment: For wastewater with higher requirements, advanced treatment such as reverse osmosis, ultrafiltration, ion exchange, etc. can be carried out to remove salt and other trace pollutants in the wastewater and improve the effluent quality.

[0010] As can be seen, the treatment process for photovoltaic aluminum alloy anodizing wastewater is long and inefficient, typically requiring 4-5 days to treat a batch of wastewater and meet discharge standards. Developing more efficient and economical wastewater treatment technologies is a constant focus for industry researchers. Summary of the Invention

[0011] The purpose of the present invention is to overcome the problems of long treatment process and low efficiency of the existing photovoltaic aluminum alloy anodizing wastewater, and to provide a photovoltaic aluminum profile anodizing wastewater treatment method. Through electrostatic spinning fiber membrane and resin adsorption technology, the process flow is greatly shortened, and the treatment cycle is compressed to 1 day, which greatly improves the sewage treatment efficiency. It is particularly suitable for large-scale centralized treatment of photovoltaic aluminum alloy anodizing wastewater.

[0012] The modified nanofiber membrane obtained by modification in the present invention can simultaneously remove multiple heavy metal pollutants, but it cannot effectively remove inorganic non-metallic pollutants and organic pollutants. For this reason, the inventors have tried many experiments and tried a variety of filter materials. Finally, they found that a specific combination of cationic resin and anionic resin can cooperate with the modified nanofiber membrane to complete the removal of multiple pollutants in three limited treatment steps, including heavy metal ions, total phosphorus, total nitrogen, ammonia nitrogen and organic pollutants.

[0013] Resin adsorption technology is commonly used in wastewater treatment. However, conventional resins have high material sensitivity and poor adaptability to wastewater of different compositions. In addition, the resin has certain requirements for the wastewater entering the resin system, that is, there are certain pollutant thresholds. If the threshold is exceeded, resin adsorption cannot achieve a stable purification effect. This application uses German Lanxess: MonoPlus S100 and MonoPlus MP500 are connected in series. The former can be used with the effluent treated with the modified nanofiber membrane to meet the resin threshold requirements, thereby avoiding the addition of additional processes before the sewage enters the resin; after treatment with the cation exchange resin, the concentrations of total nitrogen, ammonia nitrogen, suspended solids and chemical oxygen demand in the sewage are significantly reduced, which just meets the treatment threshold requirements of the anion exchange resin. Then, the anion exchange resin is used to further adsorb phosphate, total phosphorus, fluoride, etc., reducing the concentration of pollutants, while avoiding the pretreatment of the anion exchange resin and the clogging of the resin.

[0014] The specific plan is as follows:

[0015] A method for treating photovoltaic aluminum profile anodizing wastewater comprises the following steps:

[0016] S1. Filtering the photovoltaic aluminum profile anodizing wastewater through a grid to obtain raw water;

[0017] S2. Passing the raw water into an electrospinning tank, wherein the electrospinning tank uses a modified nanofiber membrane as a filter material to filter the raw water, and collecting the filtrate for the next step; the preparation method of the modified nanofiber membrane comprises: dispersing polylactic acid in a solvent to obtain a dispersion, adding vanadium carbide to the dispersion, stirring uniformly to obtain a spinning solution, adding the spinning solution to an electrospinning device for electrospinning to obtain a modified nanofiber membrane;

[0018] S3, the filtrate is sent to a cation exchange resin device for adsorption treatment, the cation exchange resin device is made of German Lanxess MonoPlus S100 was used as the filter material, and the effluent was collected after adsorption treatment for the next step;

[0019] S4, the effluent is sent to an anion exchange resin device for adsorption treatment, and the cation exchange resin device is made of German Lanxess MonoPlus MP500 is the filter material, and the effluent after adsorption treatment is reused or discharged as reclaimed water.

[0020] Furthermore, the composition of the raw water described in S1 includes: nickel 1-10 mg / L, tin 1-10 mg / L, aluminum 1-10 mg / L, phosphate 1-10 mg / L, total phosphorus 1-10 mg / L, total nitrogen 10-30 mg / L, ammonia nitrogen 1-30 mg / L, suspended matter 10-30 mg / L, fluoride 1-10 mg / L, and a chemical oxygen demand concentration of 10-50 CODcr.

[0021] Furthermore, the solvent in S2 is a mixed solvent of dichloromethane and dimethylformamide in a mass ratio of 2-3:1. This mixed solvent in the above ratio facilitates the dissolution and uniform dispersion of the polylactic acid, and facilitates low-temperature solvent volatilization during the drying of the fiber membrane, thereby protecting the modified fiber membrane and preventing loss of the loaded vanadium carbide particles.

[0022] Furthermore, the amount of vanadium carbide added in S2 is 7-15% of the total weight of the polylactic acid in the dispersion. Under the above conditions, it is beneficial to obtain a better metal ion removal effect, with a simultaneous removal effect on nickel and tin, while helping to maintain the mechanical properties of the material. Conventional polylactic acid electrospun fibers do not have a simultaneous removal effect on nickel and tin, so this application uses vanadium carbide to modify polylactic acid electrospun fibers.

[0023] Furthermore, the electrospinning voltage in S2 is selected to be 10-15 kV, the ejection flow rate is 1.0-3.0 ml / h, and the receiving distance is 10-15 cm. By controlling the spinning process under the above conditions, a nanofiber membrane with stable quality can be obtained, with a product yield exceeding 98.0%.

[0024] Furthermore, the filtrate in S2 after being treated with the nanofiber membrane contains 0.1-1 mg / L nickel, 0.1-1 mg / L tin, and 0.1-1 mg / L aluminum.

[0025] Furthermore, the total flow rate of the cation exchange resin device in S3 is (2-6)*10 -2 m / s.

[0026] Furthermore, under the above flow rate control conditions, the cationic resin has a good removal effect on total nitrogen and ammonia nitrogen. The effluent in S3 contains 1-5 mg / L of total nitrogen and 1-5 mg / L of ammonia nitrogen.

[0027] Furthermore, the total flow rate of the cation exchange resin device in S4 is (2-6)*10 -2 m / s.

[0028] Furthermore, under the above-mentioned flow rate control conditions, the anion resin has a good removal effect on total phosphorus, phosphate and organic pollutants, and the effluent described in S4 contains no more than 0.1 mg / L of nickel, no more than 0.1 mg / L of tin, no more than 0.1 mg / L of aluminum, no more than 0.1 mg / L of phosphate, no more than 0.1 mg / L of total phosphorus, no more than 1 mg / L of total nitrogen, no more than 1 mg / L of ammonia nitrogen, no more than 1 mg / L of suspended solids, no more than 1 mg / L of fluoride, and no more than 2CODcr.

[0029] Beneficial effects: The present invention uses modified nanofiber membranes to treat raw water, and simultaneously removes multiple heavy metal ions such as nickel and tin, which helps to shorten the process flow and complete the treatment of multiple batches of photovoltaic aluminum profile anodizing wastewater in one day, thereby improving the treatment efficiency.

[0030] Furthermore, in view of the characteristics of total phosphorus, total nitrogen, ammonia nitrogen and organic pollutants in the wastewater after electrospinning membrane treatment, this application uses cationic resin and anionic resin from Germany's Lanxess for series treatment, so as to further remove pollutants and meet emission standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings. Obviously, the drawings described below only relate to some embodiments of the present invention, rather than limiting the present invention.

[0032] Figure 1 It is a process flow chart provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. In the examples, if specific techniques or conditions are not specified, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used that do not specify the manufacturer are conventional products that can be obtained commercially. In the following examples, if not clearly stated, "%" refers to weight percentage.

[0034] The test methods used below include:

[0035] The pollutant content in the wastewater is detected in accordance with the "Electroplating Pollutant Emission Standard" GB21900-2008 and the "Comprehensive Wastewater Discharge Standard" GB 8978-1996.

[0036] The main raw materials used include:

[0037] Cationic resin model: Lanxess, Germany MonoPlus S100, and D116 macroporous cation exchange resins.

[0038] Anionic resin model: Lanxess, Germany MonoPlus MP500, and D301 macroporous anion exchange resin.

[0039] Example 1

[0040] Photovoltaic aluminum profile anodizing wastewater treatment method, wherein the wastewater originates from the photovoltaic aluminum profile anodizing section and is filtered through a grid to obtain raw water, the composition of which is shown in Table 1. Caustic soda flakes are added to the raw water to adjust the pH to 7, thereby obtaining acid-base neutralized wastewater.

[0041] Table 1 Wastewater composition analysis

[0042]

[0043] like Figure 1 As shown, the wastewater after acid-base neutralization is passed into an electrospinning tank. This electrospinning tank uses a modified nanofiber membrane as the filter material to filter the wastewater. In this embodiment, two identical electrospinning tanks are connected in parallel to increase the wastewater treatment throughput.

[0044] The raw material dosage of the modified nanofiber membrane is shown in Table 2. The preparation method is as follows:

[0045] S1, dispersing polylactic acid in a mixed solvent of dichloromethane and dimethylformamide, wherein the mass ratio of dichloromethane to dimethylformamide is 2:1, to obtain a dispersion;

[0046] S2, adding vanadium carbide to the dispersion and stirring evenly to obtain a spinning solution;

[0047] S3. Add the spinning solution into the electrospinning equipment, use the electrospinning equipment to perform spinning, select a spinning voltage of 12KV, a spray flow rate of 1.0ml / h, a receiving distance of 10cm, and use aluminum foil as a receiving plate. Dry the prepared nanofiber membrane at 50°C for 24 hours, and take out to obtain a modified nanofiber membrane.

[0048] Table 2 Raw material usage of modified nanofiber membrane

[0049]

[0050] The content of the filtrate obtained by filtration in the electrospinning tank is shown in Table 1.

[0051] As can be seen from Table 1, after treatment with the two-dimensional metal carbide electrospun nanofiber membrane, the metal ion concentration in the solution dropped significantly, but inorganic non-metallic pollutants and organic pollutants still existed.

[0052] Next, the filtrate obtained by the electrospinning tank filtration treatment is sent to the cation exchange resin device. The cation exchange resin device is equipped with pre-treated cationic resin: German Lanxess MonoPlus S100 treatment method: First, soak the resin in saturated salt water (approximately twice the volume of the resin being treated) for 18-20 hours. Drain the salt water and rinse with clean water until the effluent is no longer yellow. Next, soak the resin in the same amount of 4wt% NaOH solution for 2-4 hours (or rinse at a low flow rate). After draining the alkali, rinse the resin until the effluent is nearly neutral. Finally, soak the resin in the same amount of 5wt% HCl solution for 4-8 hours, drain the acid, and rinse with clean water until the effluent is neutral.

[0053] In this embodiment, the cation exchange resin device uses two identical cation exchange resin devices connected in parallel. The total flow rate of wastewater in the cation exchange resin device is: 4*10 -2 m / s, and then the wastewater after resin adsorption was discharged and its composition was analyzed, see Table 1.

[0054] As can be seen from Table 1, the electrospun nanofiber membrane combined with two-dimensional metal carbide has reduced the content of various components in the sewage to a threshold that can be treated by cationic resin. After entering the cationic exchange resin device, the total nitrogen and ammonia nitrogen in the sewage are significantly reduced after adsorption treatment by the cationic resin; at the same time, no blockage of the cationic exchange resin device is observed.

[0055] In order to further reduce the concentrations of phosphate, total phosphorus, fluoride and chemical oxygen demand, the wastewater after the cation exchange resin adsorption treatment is sent to the anion exchange resin device. In this embodiment, the anion exchange resin device uses two identical anion exchange resin devices in parallel. The anion exchange resin is from Lanxess, Germany. MonoPlus MP500 is pretreated as follows: First, soak the resin in saturated saline solution (approximately twice the volume of the resin being treated) for 18-20 hours. Drain the saline solution and rinse with clean water until the effluent is no longer yellow. Then, soak the resin in 5wt% HCl for 4-8 hours, drain the acid, and rinse with water until neutral. Then, soak the resin in 4wt% NaOH solution for 4-8 hours, drain the alkali, and rinse with clean water until neutral.

[0056] The total flow rate of wastewater in the anion exchange resin device is: 4*10 -2 m / s, and then the wastewater after resin adsorption was discharged and its composition was analyzed, see Table 1.

[0057] As can be seen from Table 1, the values ​​of phosphate, total phosphorus, fluoride, and chemical oxygen demand are all reduced, indicating that the anion exchange resin has a further removal effect on the above pollutants, and at the same time, the anion exchange resin device is not blocked.

[0058] This study demonstrates the effectiveness of using anionic and cationic resins in conjunction with two-dimensional metal carbide electrospun fiber membranes for wastewater treatment, demonstrating their effectiveness not only against heavy metal ions but also against other pollutants in the wastewater. Specifically, wastewater treated with the two-dimensional metal carbide electrospun fiber membrane can reduce the concentration of pollutants in the wastewater to a level suitable for treatment with anionic and cationic resins, thereby avoiding the problem of anionic and cationic resins failing during use. Furthermore, the wastewater treated with both treatments achieves a high degree of purity, demonstrating the effectiveness of the fiber membrane and resin combination in treating wastewater.

[0059] Example 2

[0060] A method for treating photovoltaic aluminum profile anodizing wastewater, wherein the wastewater comes from the photovoltaic aluminum profile anodizing section, and is filtered through a grid to obtain raw water, the composition of which is the same as that of Example 1.

[0061] Caustic soda flakes are added to the raw water to adjust the pH to 7, producing acid-base neutralized wastewater. The neutralized wastewater is passed through an electrospinning tank. This tank uses a modified nanofiber membrane as a filter material to filter the wastewater. In this example, two identical electrospinning tanks are connected in parallel to increase wastewater treatment throughput.

[0062] The preparation method of the modified nanofiber membrane is as follows:

[0063] S1, dispersing polylactic acid in a mixed solvent of dichloromethane and dimethylformamide, wherein the mass ratio of dichloromethane to dimethylformamide is 3:1, to obtain a dispersion;

[0064] S2. Adding vanadium carbide to the dispersion, wherein the amount of vanadium carbide added is 10% of the total weight of the polylactic acid in the dispersion, and stirring uniformly to obtain a spinning solution;

[0065] S3. Add the spinning solution into the electrospinning equipment, use the electrospinning equipment to perform spinning, select a spinning voltage of 13KV, a spray flow rate of 1.0ml / h, a receiving distance of 12cm, use aluminum foil as a receiving plate, dry the prepared nanofiber membrane at 50°C for 24 hours, and take out to obtain a modified nanofiber membrane.

[0066] Next, the filtrate obtained by the electrospinning tank filtration treatment is sent to the cation exchange resin device. The cation exchange resin device is equipped with pre-treated cationic resin from German Lanxess. MonoPlus S100, the processing method is the same as Example 1.

[0067] In this embodiment, the cation exchange resin device uses two identical cation exchange resin devices connected in parallel. The total flow rate of wastewater in the cation exchange resin device is: 5*10 -2 m / s.

[0068] Finally, the wastewater after the cation exchange resin adsorption treatment is sent to the anion exchange resin device. In this embodiment, the anion exchange resin device uses two identical anion exchange resin devices in parallel. The anion exchange resin is from Lanxess, Germany. MonoPlus MP500 was pre-treated in advance, and the treatment method was the same as in Example 1. The total flow rate of the wastewater in the anion exchange resin device was: 5*10 -2 m / s, and then the wastewater after resin adsorption was discharged and its composition was analyzed, see Table 3.

[0069] Example 3

[0070] A method for treating photovoltaic aluminum profile anodizing wastewater, wherein the wastewater comes from the photovoltaic aluminum profile anodizing section, and is filtered through a grid to obtain raw water, the composition of which is the same as that of Example 1.

[0071] Caustic soda flakes are added to the raw water to adjust the pH to 7, producing acid-base neutralized wastewater. The neutralized wastewater is passed through an electrospinning tank. This tank uses a modified nanofiber membrane as a filter material to filter the wastewater. In this example, two identical electrospinning tanks are connected in parallel to increase wastewater treatment throughput.

[0072] The preparation method of the modified nanofiber membrane is as follows:

[0073] S1, dispersing polylactic acid in a mixed solvent of dichloromethane and dimethylformamide, wherein the mass ratio of dichloromethane to dimethylformamide is 3:1, to obtain a dispersion;

[0074] S2. Adding vanadium carbide to the dispersion, wherein the amount of vanadium carbide added is 12% of the total weight of the polylactic acid in the dispersion, and stirring uniformly to obtain a spinning solution;

[0075] S3. Add the spinning solution into the electrospinning equipment, use the electrospinning equipment to perform spinning, select a spinning voltage of 13KV, a spray flow rate of 1.0ml / h, a receiving distance of 12cm, use aluminum foil as a receiving plate, dry the prepared nanofiber membrane at 50°C for 24 hours, and take out to obtain a modified nanofiber membrane.

[0076] Next, the filtrate obtained by the electrospinning tank filtration treatment is sent to the cation exchange resin device. The cation exchange resin device is equipped with pre-treated cationic resin from German Lanxess. MonoPlus S100, the processing method is the same as Example 1.

[0077] In this embodiment, the cation exchange resin device uses two identical cation exchange resin devices connected in parallel. The total flow rate of wastewater in the cation exchange resin device is: 5*10 -2 m / s.

[0078] Finally, the wastewater after the cation exchange resin adsorption treatment is sent to the anion exchange resin device. In this embodiment, the anion exchange resin device uses two identical anion exchange resin devices in parallel. The anion exchange resin is from Lanxess, Germany. MonoPlus MP500 was pre-treated in advance, and the treatment method was the same as in Example 1. The total flow rate of the wastewater in the anion exchange resin device was: 5*10 -2 m / s, and then the wastewater after resin adsorption was discharged and its composition was analyzed, see Table 3.

[0079] Example 4

[0080] A method for treating photovoltaic aluminum profile anodizing wastewater, wherein the wastewater comes from the photovoltaic aluminum profile anodizing section, and is filtered through a grid to obtain raw water, the composition of which is the same as that of Example 1.

[0081] Caustic soda flakes are added to the raw water to adjust the pH to 7, producing acid-base neutralized wastewater. The neutralized wastewater is passed through an electrospinning tank. This tank uses a modified nanofiber membrane as a filter material to filter the wastewater. In this example, two identical electrospinning tanks are connected in parallel to increase wastewater treatment throughput.

[0082] The preparation method of the modified nanofiber membrane is as follows:

[0083] S1, dispersing polylactic acid in a mixed solvent of dichloromethane and dimethylformamide, wherein the mass ratio of dichloromethane to dimethylformamide is 3:1, to obtain a dispersion;

[0084] S2. Adding vanadium carbide to the dispersion, wherein the amount of vanadium carbide added is 10% of the total weight of the polylactic acid in the dispersion, and stirring uniformly to obtain a spinning solution;

[0085] S3. Add the spinning solution into the electrospinning equipment, use the electrospinning equipment to perform spinning, select the spinning voltage as 10KV, the spray flow rate as 2.0ml / h, the receiving distance as 12cm, use aluminum foil as the receiving plate, dry the prepared nanofiber membrane at 50°C for 24 hours, and take out to obtain the modified nanofiber membrane.

[0086] Next, the filtrate obtained by the electrospinning tank filtration treatment is sent to the cation exchange resin device. The cation exchange resin device is equipped with pre-treated cationic resin from German Lanxess. MonoPlus S100, the processing method is the same as Example 1.

[0087] In this embodiment, the cation exchange resin device uses two identical cation exchange resin devices connected in parallel. The total flow rate of wastewater in the cation exchange resin device is: 5*10 -2 m / s.

[0088] Finally, the wastewater after the cation exchange resin adsorption treatment is sent to the anion exchange resin device. In this embodiment, the anion exchange resin device uses two identical anion exchange resin devices in parallel. The anion exchange resin is from Lanxess, Germany. MonoPlus MP500 was pre-treated in advance, and the treatment method was the same as in Example 1. The total flow rate of the wastewater in the anion exchange resin device was: 5*10 -2 m / s, and then the wastewater after resin adsorption was discharged and its composition was analyzed, see Table 3.

[0089] Example 5

[0090] A method for treating photovoltaic aluminum profile anodizing wastewater, wherein the wastewater comes from the photovoltaic aluminum profile anodizing section, and is filtered through a grid to obtain raw water, the composition of which is the same as that of Example 1.

[0091] Caustic soda flakes are added to the raw water to adjust the pH to 7, producing acid-base neutralized wastewater. The neutralized wastewater is passed through an electrospinning tank. This tank uses a modified nanofiber membrane as a filter material to filter the wastewater. In this example, two identical electrospinning tanks are connected in parallel to increase wastewater treatment throughput.

[0092] The preparation method of the modified nanofiber membrane is as follows:

[0093] S1, dispersing polylactic acid in a mixed solvent of dichloromethane and dimethylformamide, wherein the mass ratio of dichloromethane to dimethylformamide is 3:1, to obtain a dispersion;

[0094] S2. Adding vanadium carbide to the dispersion, wherein the amount of vanadium carbide added is 10% of the total weight of the polylactic acid in the dispersion, and stirring uniformly to obtain a spinning solution;

[0095] S3. Add the spinning solution into the electrospinning equipment, use the electrospinning equipment to perform spinning, select a spinning voltage of 13KV, a spray flow rate of 1.0ml / h, a receiving distance of 12cm, use aluminum foil as a receiving plate, dry the prepared nanofiber membrane at 50°C for 24 hours, and take out to obtain a modified nanofiber membrane.

[0096] Next, the filtrate obtained by the electrospinning tank filtration treatment is sent to the cation exchange resin device. The cation exchange resin device is equipped with pre-treated cationic resin from German Lanxess. MonoPlus S100, the processing method is the same as Example 1.

[0097] In this embodiment, the cation exchange resin device uses two identical cation exchange resin devices connected in parallel. The total flow rate of wastewater in the cation exchange resin device is: 6*10 -2 m / s.

[0098] Finally, the wastewater after the cation exchange resin adsorption treatment is sent to the anion exchange resin device. In this embodiment, the anion exchange resin device uses two identical anion exchange resin devices in parallel. The anion exchange resin is from Lanxess, Germany. MonoPlus MP500 was pre-treated in advance, and the treatment method was the same as in Example 1. The total flow rate of the wastewater in the anion exchange resin device was: 6*10 -2 m / s, and then the wastewater after resin adsorption was discharged and its composition was analyzed, see Table 3.

[0099] Table 3 Wastewater treatment results of Examples 2-5

[0100]

[0101]

[0102] Comparative Example 1

[0103] Referring to Example 1, conventional cationic resin D116 macroporous cationic exchange resin was used to replace the cationic exchange resin in Example 1. Other methods were the same as in Example 1. The raw water was treated as follows:

[0104] Caustic soda flakes were added to the raw water to adjust the pH to 7, producing neutralized wastewater. The neutralized wastewater was then passed through an electrospinning tank. This tank, using a modified nanofiber membrane (same as in Example 1) as the filter material, filtered the wastewater. Two identical electrospinning tanks were connected in parallel to increase wastewater treatment throughput.

[0105] Next, the filtrate obtained by the electrospinning tank filtration treatment is sent to the cation exchange resin device. The cation exchange resin device is equipped with pre-treated cation resin, which is D116 macroporous cation exchange resin, and is pre-treated using conventional resin activation methods. The cation exchange resin device uses two identical cation exchange resin devices in parallel. The total flow rate of wastewater in the cation exchange resin device is: 4*10 -2 m / s, and then the wastewater adsorbed by the resin is discharged.

[0106] In order to further reduce the pollutant content, the wastewater after the cation exchange resin adsorption treatment is sent to the anion exchange resin device. The anion exchange resin device uses two identical anion exchange resin devices in parallel. The anion exchange resin is from Lanxess, Germany. MonoPlus MP500 was pre-treated in advance, referring to Example 1. The total flow rate of wastewater in the anion exchange resin device was: 4*10 -2 m / s, and then the wastewater adsorbed by the resin is discharged. The results are shown in the table below.

[0107] Table 4 Comparative Example 1 Wastewater Treatment Effect

[0108]

[0109]

[0110] From the above table, it can be found that after replacing with conventional cationic resin, the device has the ability to remove metal ions, but the removal ability of phosphate, total phosphorus and total nitrogen is significantly reduced. Therefore, the final water quality after treatment does not meet the first-level emission standards.

[0111] Comparative Example 2

[0112] Referring to Example 1, conventional anion resin D301 macroporous anion exchange resin was used to replace the anion exchange resin in Example 1. Other methods were the same as in Example 1. The raw water was treated as follows:

[0113] Caustic soda flakes were added to the raw water to adjust the pH to 7, producing neutralized wastewater. The neutralized wastewater was then passed through an electrospinning tank. This tank, using a modified nanofiber membrane (same as in Example 1) as the filter material, filtered the wastewater. Two identical electrospinning tanks were connected in parallel to increase wastewater treatment throughput.

[0114] Next, the filtrate obtained by the electrospinning tank filtration treatment is sent to the cation exchange resin device. The cation exchange resin device is equipped with pre-treated cationic resin, which is from Lanxess, Germany. MonoPlus S100, the pre-treatment method is the same as in Example 1. The cation exchange resin device uses two identical cation exchange resin devices in parallel, and the total flow rate of wastewater in the cation exchange resin device is: 4*10 -2 m / s, and then the wastewater adsorbed by the resin is discharged.

[0115] In order to further reduce the pollutant content, the wastewater after the cation exchange resin adsorption treatment is sent to the anion exchange resin device. The anion exchange resin device uses two identical anion exchange resin devices in parallel. The anion exchange resin is D301 macroporous anion exchange resin, and is pretreated in advance using conventional resin activation methods. The total flow rate of the wastewater in the anion exchange resin device is: 4*10 -2 m / s, and then the wastewater adsorbed by the resin is discharged. The results are shown in the table below.

[0116] Table 5 Comparative Example 2 Wastewater Treatment Effect

[0117]

[0118] As can be seen from the table above, while the device maintains its ability to remove metal ions after replacing it with conventional anion resin, its ability to remove phosphate and total phosphorus has significantly decreased. According to the Level 1 standard in Table 4 of the "Comprehensive Wastewater Discharge Standard" GB8978-1996, the phosphate concentration must be ≤0.5 mg / L. This means that the final treated water quality just meets the Level 1 discharge standard for phosphates. However, there is the potential for fluctuations in treatment effectiveness due to fluctuations in the raw water composition. Therefore, the risk of substandard water quality persists with long-term operation of this device. Furthermore, the anion exchange resin device exhibits poor liquid outflow, suggesting possible resin clogging.

[0119] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0120] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0121] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for treating photovoltaic aluminum profile anodizing wastewater, characterized by: The following steps are involved: S1. Filtering the photovoltaic aluminum profile anodizing wastewater through a grid to obtain raw water; S2, passing the raw water into an electrospinning tank, wherein the electrospinning tank uses a modified nanofiber membrane as a filter material to filter the raw water, and collecting the filtrate for the next step; The modified nanofiber membrane is prepared by dispersing polylactic acid in a solvent to obtain a dispersion, adding vanadium carbide to the dispersion, stirring uniformly to obtain a spinning solution, adding the spinning solution to an electrospinning device for electrospinning to obtain a modified nanofiber membrane; S3, sending the filtrate to a cation exchange resin device for adsorption treatment, wherein the cation exchange resin device uses German Lanxess Lewatit® MonoPlus S100 as the filter material, and collecting the effluent after the adsorption treatment for the next step; S4. The effluent is sent to an anion exchange resin device for adsorption treatment. The anion exchange resin device uses German Lanxess Lewatit® MonoPlus MP500 as the filter material. The effluent after adsorption treatment is reused as reclaimed water or discharged.

2. The photovoltaic aluminum profile anodizing wastewater treatment method according to claim 1, characterized in that: The composition of the raw water described in S1 includes: nickel 1-10 mg / L, tin 1-10 mg / L, aluminum 1-10 mg / L, phosphate 1-10 mg / L, total phosphorus 1-10 mg / L, total nitrogen 10-30 mg / L, ammonia nitrogen 1-30 mg / L, suspended matter 10-30 mg / L, fluoride 1-10 mg / L, and chemical oxygen demand CODcr concentration of 10-50 mg / L.

3. The photovoltaic aluminum profile anodizing wastewater treatment method according to claim 2, characterized in that: The solvent in S2 is a mixed solvent of dichloromethane and dimethylformamide, with a mass ratio of 2-3:

1.

4. The photovoltaic aluminum profile anodizing wastewater treatment method according to claim 3, characterized in that: The amount of vanadium carbide added in S2 is 7-15% of the total weight of the polylactic acid in the dispersion.

5. The photovoltaic aluminum profile anodizing wastewater treatment method according to claim 4, characterized in that: The electrospinning voltage of S2 is 10-15 KV, the ejection flow rate is 1.0-3.0 ml / h, and the receiving distance is 10-15 cm.

6. The photovoltaic aluminum profile anodizing wastewater treatment method according to claim 5, characterized in that: The filtrate in S2 contains 0.1-1 mg / L nickel, 0.1-1 mg / L tin, and 0.1-1 mg / L aluminum.

7. The photovoltaic aluminum profile anodizing wastewater treatment method according to any one of claims 2 to 5, characterized in that: The total flow rate of the cation exchange resin device in S3 is 2×10 -2 m / s-6×10 -2 m / s.

8. The photovoltaic aluminum profile anodizing wastewater treatment method according to claim 6, characterized in that: The effluent in S3 contains 1-5 mg / L of total nitrogen and 1-5 mg / L of ammonia nitrogen.

9. The photovoltaic aluminum profile anodizing wastewater treatment method according to claim 8, characterized in that: The total flow rate of the anion exchange resin device in S4 is 2×10 -2 m / s-6×10 -2 m / s.

10. The photovoltaic aluminum profile anodizing wastewater treatment method according to claim 9, characterized in that: The effluent described in S4 contains no more than 0.1 mg / L of nickel, no more than 0.1 mg / L of tin, no more than 0.1 mg / L of aluminum, no more than 0.1 mg / L of phosphate, no more than 0.1 mg / L of total phosphorus, no more than 1 mg / L of total nitrogen, no more than 1 mg / L of ammonia nitrogen, no more than 1 mg / L of suspended solids, no more than 1 mg / L of fluoride, and the chemical oxygen demand (CODcr) concentration does not exceed 2 mg / L.

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