Method for improving effect of treating mixed dye wastewater by iron-based amorphous alloy

Abstract

The application discloses a method for improving the treatment effect of mixed dye wastewater by using an iron-based amorphous alloy, and the method comprises the following steps: uniformly mixing a silane coupling agent, anhydrous ethanol and FeCoCrMoCBY iron-based amorphous alloy powder, ultrasonically reacting and drying the obtained mixture to obtain silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder, and then applying the silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder to effective degradation treatment of mixed dye wastewater. The application realizes a great improvement of the treatment effect of mixed dye wastewater by using the synergistic effect of the FeCoCrMoCBY iron-based amorphous alloy and the silane coupling agent, and has the advantages of time effectiveness, low use cost, strong practicability and suitability for popularization and use.

Description

[0001] The application relates to a method for improving the effect of treating mixed dye wastewater by using an iron-based amorphous alloy, and belongs to the technical field of wastewater treatment. BACKGROUND

[0002] A large amount of dye wastewater is generated in the production processes of the textile, papermaking and leather industries. The main components of the dyes are polycyclic aromatic compounds and heavy metal salts such as lead, arsenic, chromium and mercury. Such substances have the characteristics of high toxicity, high colority and difficult degradation. Dye wastewater, as a kind of synthetic organic pollutant, has a harmful effect on the environment and water resources. Mixed dyes usually exist in actual wastewater, which means that two or more dyes exist in the dye wastewater. The two dyes in the mixed dyes may interfere with each other and cause a more complex degradation process. Therefore, it is of great significance to provide an efficient mixed dye treatment method.

[0003] At present, the common methods for treating wastewater mainly include biological methods, physical methods and chemical methods. The biological method has high requirements on the environment, cannot treat high-concentration dye wastewater, and is also prone to generate biologically toxic aromatic amines. The physical method is selectively adsorbed due to different types of dyes, and the use range is greatly limited. The chemical method commonly uses zero-valent iron catalyst to treat dye wastewater, but a large amount of sludge is generated in the treatment process, and the catalyst is also easily oxidized during storage, which easily leads to catalyst failure. Therefore, it is particularly important to find a new type of catalyst material with low cost and high reaction activity. Iron-based amorphous alloys have become a research hotspot in the field of catalytic degradation due to their characteristics of disordered atomic structure, sufficient active sites and strong corrosion resistance.

[0004] At present, there are some literature reports on the use of iron-based amorphous alloys for treating printing and dyeing wastewater. The patent “Application of an iron-based amorphous alloy strip for treating printing and dyeing wastewater” (CN102070236B) discloses the use of Fe-Mo-Si-B amorphous alloy for degrading and treating direct blue 2B. The results show that the color of the dye solution is completely faded after 60 minutes of degradation treatment. The patent “Application of an iron-based amorphous alloy for degrading methylene blue in dye wastewater” (CN108525688A) uses Fe 80 P 13C7 amorphous alloy degrades methylene blue dye wastewater, and at least 10 minutes is needed under the optimal condition to basically remove the methylene blue dye. The method for degrading azo dye by ultrasonic-assisted iron-based amorphous coating (CN114988551 A) realizes the degradation of iron-based amorphous coating on gold orange II dye wastewater by adding an external ultrasonic field. The amount of iron-based amorphous coating used in the catalytic degradation process is 2-32 g / L. The method for degrading wastewater by iron-based amorphous alloy strip (CN111170414B) improves the degradation rate by ball milling the iron-based amorphous alloy strip for 4-8 hours. The preparation process of the above-mentioned iron-based amorphous alloy is relatively complex, the timeliness of treating wastewater is poor, the amount of reagent is large, some of them also contain phosphorus element, which is easy to cause secondary pollution to wastewater, and the practical application is difficult, which does not fundamentally solve the timeliness and practicality of wastewater treatment. SUMMARY

[0005] The purpose of the present application is to provide a method for adsorption and Fenton-like synergistic effect for treating mixed dye wastewater, for degrading mixed dye wastewater, so as to solve the problems of low degradation efficiency of dye wastewater and easy failure of catalyst.

[0006] In order to achieve the above-mentioned purpose, the method for improving the effect of iron-based amorphous alloy in treating mixed dye wastewater utilizes the synergistic effect of FeCoCrMoCBY iron-based amorphous alloy and silane coupling agent to promote the agglomeration, sedimentation and degradation of mixed dyes, and the specific steps are as follows:

[0007] Step 1: uniformly mix the silane coupling agent, anhydrous ethanol and FeCoCrMoCBY iron-based amorphous alloy powder to obtain a mixture;

[0008] Step 2: after ultrasonic reaction, the mixture is dried to obtain silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder;

[0009] Step 3: the silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder is added to the mixed dye wastewater, then H2O2 is added, and the pH is adjusted to 1-7, and the effective degradation of the mixed dye wastewater is realized under the condition of 35°C and stirring.

[0010] The particle size of the FeCoCrMoCBY iron-based amorphous alloy powder is 35-45 μm.

[0011] The mass ratio of the FeCoCrMoCBY iron-based amorphous alloy powder, anhydrous ethanol and silane coupling agent is 3:18:2.

[0012] The preparation process of the FeCoCrMoCBY iron-based amorphous alloy powder is that: Fe, Co, Cr, Mo, C, FeB and Y raw materials with a purity of 99.99% are mixed in proportion, then a master alloy is obtained by vacuum arc melting, and then FeCoCrMoCBY iron-based amorphous alloy powder is obtained by cutting, grinding, vacuum gas atomization and screening in sequence; wherein the vacuum arc melting parameters are: the voltage is 20 V, the current is 300 A, and the mass ratio of Fe, Co, Cr, Mo, C, FeB and Y raw materials is 38.95:26.25:56.25:52.5:56.25:137.3:7.5.

[0013] The ultrasonic reaction time is 1-30 min.

[0014] The concentration of H2O2 is 20 mmol / L.

[0015] The pH is preferably 3.

[0016] The silane coupling agent is 3-aminopropyl triethoxysilane.

[0017] The stirring speed is 550-600 r / min.

[0018] The principle of the application is that: the FeCoCrMoCBY iron-based amorphous alloy surface has hydroxyl groups, the silane coupling agent is connected with the hydroxyl groups through coupling, thereby realizing the adhesion with the FeCoCrMoCBY iron-based amorphous alloy, and the ultrasonic environment can promote the adhesion of the silane coupling agent and the FeCoCrMoCBY iron-based amorphous alloy. After the silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy is put into mixed dye wastewater, the silane coupling agent adhered to the surface of the FeCoCrMoCBY iron-based amorphous alloy will partially hydrolyze to form silanol, and the silanol will form a polymer in the solution, which will connect the dye molecules together, promoting the agglomeration and sedimentation of the mixed dyes; the silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy will also react with H2O2 to generate hydroxyl radicals (•OH). The •OH will oxidize the remaining dye molecules and degrade them into smaller molecules. The present application utilizes the synergistic effect of FeCoCrMoCBY iron-based amorphous alloy and silane coupling agent to realize the effective degradation of mixed dyes.

[0019] The application utilizes the synergistic effect of FeCoCrMoCBY iron-based amorphous alloy powder and silane coupling agent to promote the agglomeration and degradation of mixed dyes. Compared with the existing iron-based amorphous alloy for degrading dyes, the modified FeCoCrMoCBY iron-based amorphous alloy has a simple preparation process, is easy to operate, and can achieve a nearly 100% decolorization effect in 5 minutes when applied to wastewater treatment. The degradation rate is greatly improved, the time effectiveness is outstanding, the use cost is low, the practicality is strong, and the application is suitable for popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The scanning electron microscope image of the FeCoCrMoCBY iron-based amorphous alloy powder without modification in the present application comparative example 1;

[0021] Figure 2 The scanning electron microscope image of the silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder after 5 minutes of ultrasonic treatment in the present application example 2;

[0022] Figure 3 The scanning electron microscope image of the silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder after 30 minutes of ultrasonic treatment in the present application example 3;

[0023] Figure 4 The mixed dye wastewater color change graph over time in the present application example 2;

[0024] Figure 5 The mixed dye wastewater color change graph over time in the present application example 3;

[0025] Figure 6 The mixed dye wastewater color change graph over time in the present application comparative example 1;

[0026] Figure 7 The mixed dye wastewater color change graph over time in the present application comparative example 2;

[0027] Figure 8 The mixed dye wastewater color change graph over time in the present application comparative example 3;

[0028] Figure 9 The direct yellow dye decolorization rate comparison graph of mixed dye wastewater treated by FeCoCrMoCBY iron-based amorphous alloy powder, silane coupling agent, FeCoCrMoCBY iron-based amorphous alloy powder+silane coupling agent, FeCoCrMoCBY iron-based amorphous powder+silane coupling agent ultrasonic reaction for 5 minutes, FeCoCrMoCBY iron-based amorphous alloy powder+silane coupling agent ultrasonic reaction for 30 minutes, respectively;

[0029] Figure 10 : The present application uses FeCoCrMoCBY iron-based amorphous alloy powder, silane coupling agent, FeCoCrMoCBY iron-based amorphous alloy powder + silane coupling agent, FeCoCrMoCBY iron-based amorphous alloy powder + silane coupling agent ultrasonic reaction for 5 minutes, FeCoCrMoCBY iron-based amorphous alloy powder + silane coupling agent ultrasonic reaction for 30 minutes, respectively used for treating mixed dye wastewater. DETAILED DESCRIPTION

[0030] In order to make the purpose of the present application, the technical method is more clear, the following combining with the example, the present application is further explained in detail. It should be understood that the specific examples described herein are merely intended to illustrate the present application, and are not intended to limit the present application.

[0031] Example 1

[0032] Preparation of FeCoCrMoCBY iron-based amorphous alloy powder

[0033] The raw materials of Fe, Co, Cr, Mo, C, FeB and Y with a purity of 99.99% were weighed as 38.95g, 26.25g, 56.25g, 52.5g, 56.25g, 137.3g and 7.5g respectively, mixed uniformly and then put into a vacuum arc furnace for melting.

[0034] Before melting, the melting furnace was first evacuated to 4´10 -3 Pa, and then argon was introduced for atmosphere protection. The melting of the master alloy was carried out in an argon atmosphere. In order to ensure uniform distribution of elements in the master alloy, the alloy was melted at least 4 times or more, and then the master alloy was taken out after cooling. The vacuum arc melting parameters were: voltage 20 V, current 300 A. After the melting was completed, the master alloy was cut into small pieces by a wire cutting machine, and then the surface of the small pieces of alloy was polished, washed and dried to obtain the material required for vacuum gas atomization. The material required for vacuum gas atomization was placed in a quartz crucible, the atomization system was sealed, and then high-purity argon was introduced to ensure that the entire atomization system was in an inert gas atmosphere. The induction heating instrument was turned on, the small pieces of master alloy were heated to a certain temperature and then melted. The melt flowed down along the liquid guide pipe at the bottom of the crucible. At this time, the atomization switch was turned on synchronously, and the high-speed airflow acted on the melt. The molten alloy was sandblasted under high-speed liquid nitrogen, and the molten alloy wrapped in liquid nitrogen was rapidly cooled to form amorphous alloy powder. The amorphous alloy powder was sieved by using a 325 mesh standard sieve to obtain FeCoCrMoCBY iron-based amorphous alloy powder with a particle size of 35-45μm.

[0035] Example 2

[0036] Treatment of mixed dye wastewater by modified FeCoCrMoCBY iron-based amorphous alloy powder

[0037] Under the condition of 35℃, take 150 mL of mixed dye solution (concentration of 10 mg / L) of direct yellow and direct red, and adjust the pH value to 3 with dilute sulfuric acid to obtain mixed dye wastewater.

[0038] Take 4 mL of mixed dye wastewater with a syringe with a 0.45 μm filter head, and record it as the sample at 0 min before reaction, and analyze it in a UV-visible spectrophotometer; then add 0.225 grams of modified FeCoCrMoCBY iron-based amorphous alloy powder after ultrasonic reaction of FeCoCrMoCBY iron-based amorphous alloy powder + silane coupling agent 3-aminopropyl triethoxysilane to 150 mL of mixed dye wastewater; finally, add 3 mmol of 30% H2O2 solution, and mechanically stir, and take samples with a syringe with a 0.45 μm filter head at 5 min, 10 min, 15 min, 20 min, 30 min and 60 min, then add an appropriate amount of n-butanol solution, and then perform photometric analysis.

[0039] The analysis results are shown in Figure 2 , 4 , 9, 10, from Figure 2 it can be seen that the surface of the amorphous alloy powder is adhered with a lot of silane coupling agent, indicating that the coupling effect of FeCoCrMoCBY iron-based amorphous alloy powder and silane coupling agent is good under the treatment of ultrasonic environment for 5 min. From Figure 4 it can be seen that the mixed dye wastewater is dark in color, but after 5 min of treatment, the mixed dye wastewater has become colorless and transparent, indicating that the mixed dye has been basically removed. From Figure 9 , 10 it can be seen that after 5 min of treatment of the mixed dye wastewater, the decolorization rates of direct yellow and direct red in the mixed dye wastewater are as high as 98.03% and 97.91% respectively. Compared with the treatment of mixed dye wastewater with FeCoCrMoCBY amorphous alloy powder modified by silane coupling agent for 5 min, the decolorization rates of direct yellow and direct red in the mixed dye wastewater are increased by 64.59% and 34.15% respectively.

[0040] Example 3

[0041] Treatment of mixed dye wastewater with modified FeCoCrMoCBY iron-based amorphous alloy powder

[0042] Under the condition of 35℃, take 150 mL of mixed dye solution (concentration of 10 mg / L) of direct yellow and direct red, and adjust the pH value to 3 with dilute sulfuric acid to obtain mixed dye wastewater.

[0043] 4 mL of the mixed dye wastewater was taken by a syringe with a 0.45 μm filter head and recorded as the sample at 0 min before reaction, and analyzed in a UV-visible spectrophotometer; then 0.225 g of FeCoCrMoCBY amorphous alloy powder + silane coupling agent 3-aminopropyl triethoxysilane ultrasonic reaction for 30 min was added to 150 mL of the mixed dye wastewater; finally, 3 mmol of 30% H2O2 solution was added, and mechanical stirring was performed, and samples were taken by a syringe with a 0.45 μm filter head at 5 min, 10 min, 15 min, 20 min, 30 min and 60 min, and then an appropriate amount of n-butanol solution was added, and then photometric analysis was performed.

[0044] The analysis results are shown in Figure 3 、 5 , 9, 10, and it can be seen from Figure 3 that the surface of the FeCoCrMoCBY amorphous alloy powder also adheres to a lot of silane coupling agent, indicating that the coupling effect of the FeCoCrMoCBY amorphous alloy powder and the silane coupling agent 3-aminopropyl triethoxysilane is good under ultrasonic treatment for 30 min. It can be seen from Figure 5 that the mixed dye wastewater has a deep color, but after 5 min of treatment, the mixed dye solution also becomes colorless and transparent, which indicates that the mixed dye has been basically removed. It can be seen from Figure 9 、 10 that after 5 min of treatment of the mixed dye wastewater, the decolorization rates of direct yellow and direct red are as high as 97.99% and 98.59%, respectively. Compared with the treatment of the mixed dye wastewater by the FeCoCrMoCBY amorphous alloy powder without modification by the silane coupling agent for 5 min, the decolorization rates of direct yellow and direct red in the mixed dye wastewater are increased by 64.55% and 35.03%, respectively.

[0045] Example 4

[0046] Silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder

[0047] 1 g of silane coupling agent 3-aminopropyl triethoxysilane and 9 g of anhydrous ethanol were mixed with 1.5 g of FeCoCrMoCBY iron-based amorphous alloy powder to obtain a mixture;

[0048] The above mixture was subjected to ultrasonic reaction and dried at 50°C to obtain the silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder.

[0049] Comparative Example 1

[0050] Method for treating mixed dye wastewater by FeCoCrMoCBY iron-based amorphous alloy powder

[0051] Under the condition of 35℃, 150 mL of mixed solution of direct yellow and direct red (concentration of each was 10 mg / L) was obtained by adjusting pH value to 3 with dilute sulfuric acid to obtain mixed dye wastewater.

[0052] 4 mL of mixed dye wastewater was taken by a syringe with a 0.45 μm filter head and recorded as the sample at 0 min before reaction, and analyzed in a UV-visible spectrophotometer. 0.225 g of unmodified FeCoCrMoCBY iron-based amorphous alloy powder was added into 150 mL of mixed dye wastewater, and then 3 mmol of 30% H2O2 solution was added, and mechanical stirring was carried out. At 5 min, 10 min, 15 min, 20 min, 30 min and 60 min, samples were taken by a syringe with a 0.45 μm filter head, and then an appropriate amount of n-butanol solution was added, and then photometric analysis was carried out.

[0053] The analysis results are shown in Figure 1 , 6 , 9, 10, it can be seen from Figure 1 that the surface of the unmodified FeCoCrMoCBY iron-based amorphous alloy powder is relatively smooth. It can be seen from Figure 5 that the mixed dye wastewater has a deep color, and after 5 min of treatment, the mixed dye wastewater has a slightly lighter color, and after 60 min of treatment, the mixed dye wastewater still has a significant color, which indicates that the decolorization effect of the mixed dye wastewater is poor. It can be seen from Figure 9 , 10 that after 5 min of treatment of the mixed dye wastewater, the decolorization rates of direct yellow and direct red in the mixed dye wastewater are 33.44% and 63.56%, respectively; and after 60 min of treatment, the decolorization rates of direct yellow and direct red in the mixed dye wastewater are 60.59% and 82.74%, respectively.

[0054] Comparative Example 2

[0055] Treatment of mixed dye wastewater by silane coupling agent

[0056] Under the condition of 35℃, 150 mL of mixed solution of direct yellow and direct red (concentration of each was 10 mg / L) was obtained by adjusting pH value to 3 with dilute sulfuric acid to obtain mixed dye wastewater.

[0057] Using a syringe with a 0.45 μm filter, 4 mL of mixed dye wastewater was drawn and recorded as the sample at 0 min before the reaction. This sample was then analyzed using a UV-Vis spectrophotometer. 0.15 g of silane coupling agent 3-aminopropyltriethoxysilane, corresponding to 0.225 g of modified FeCoCrMoCBY iron-based amorphous alloy powder, was added to the mixed dye wastewater. Then, 3 mmol of a 30% (w / w) H₂O₂ solution was added, and the mixture was mechanically stirred. Samples were taken using a syringe with a 0.45 μm filter at reaction times of 5 min, 10 min, 15 min, 20 min, 30 min, and 60 min. An appropriate amount of n-butanol solution was then added, followed by spectrophotometric analysis.

[0058] Analysis results as follows Figure 7 , 9 As shown in Figure 10, from Figure 7 It can be seen that the mixed dye wastewater is initially dark in color. After 5 minutes of treatment, the color lightens. After 60 minutes of treatment, the color intensity of the mixed dye wastewater decreases compared to the 5-minute result, but it is still visible. This indicates that the silane coupling agent can only remove most of the mixed dyes. Figure 9 , 10 The results show that after 5 minutes of treatment, the decolorization rates of Direct Yellow and Direct Red in the mixed dye wastewater were 80.62% and 75.18%, respectively. Compared with the treatment of mixed dye wastewater with FeCoCrMoCBY iron-based amorphous alloy powder without silane coupling agent modification for 5 minutes, the decolorization rates of Direct Yellow and Direct Red increased by 47.18% and 11.62%, respectively; after 60 minutes of treatment, the decolorization rates of Direct Yellow and Direct Red in the mixed dye wastewater were 87.72% and 89.16%, respectively.

[0059] Comparative Example 3

[0060] FeCoCrMoCBY iron-based amorphous alloy + silane coupling agent treatment of mixed dye wastewater

[0061] At 35℃, 150 mL of a mixed solution of Direct Yellow and Direct Red (both with a concentration of 10 mg / L) was taken and the pH value was adjusted to 3 with dilute sulfuric acid to obtain mixed dye wastewater.

[0062] 4 mL of the mixed dye wastewater was taken by a syringe with a 0.45 μm filter head and recorded as a sample at 0 min before reaction, and analyzed in a UV-visible spectrophotometer. 0.225 grams of unmodified FeCoCrMoCBY iron-based amorphous alloy powder and 0.225 grams of modified FeCoCrMoCBY iron-based amorphous alloy powder were added to the mixed dye wastewater, and the corresponding amount (0.15 grams) of silane coupling agent 3-aminopropyl triethoxysilane was added, and then 3 mmol of 30% H2O2 solution was added, and mechanical stirring was performed, and samples were taken by a syringe with a 0.45 μm filter head at 5 min, 10 min, 15 min, 20 min, 30 min and 60 min, and then an appropriate amount of n-butanol solution was added, and then photometric analysis was performed.

[0063] The analysis results are shown in Figure 8 、 9 , 10, and it can be seen from Figure 8 that the mixed dye wastewater has a deep color, and after 5 min of treatment, the color of the mixed dye wastewater becomes lighter, and after 60 min of treatment, the color of the mixed dye wastewater is reduced compared to 5 min, but it is still visible. This shows that the silane coupling agent + unmodified FeCoCrMoCBY iron-based amorphous alloy powder can only remove most of the mixed dyes. From Figure 9 、 10 , it can be seen that after 5 min of treatment, the decolorization rates of direct yellow and direct red are 84% and 81.3%, respectively. Compared with the unmodified FeCoCrMoCBY iron-based amorphous alloy powder, the decolorization rates of direct yellow and direct red are increased by 50.56% and 17.74%, respectively. After 60 min of treatment, the decolorization rates of direct yellow and direct red are 90.4% and 91%, respectively. This shows that the treatment effect of silane coupling agent + unmodified FeCoCrMoCBY iron-based amorphous alloy powder is basically the same as that of silane coupling agent alone.

Claims

1. A method for improving the effect of treating mixed dye wastewater by iron-based amorphous alloy, characterized in that: The method utilizes the synergistic effect of FeCoCrMoCBY iron-based amorphous alloy and silane coupling agent to promote the agglomeration, sedimentation and degradation of mixed dyes, and the specific steps are as follows: Step 1: uniformly mix the silane coupling agent, anhydrous ethanol and FeCoCrMoCBY iron-based amorphous alloy powder to obtain a mixture; Step 2: after ultrasonic reaction, the mixture is dried to obtain silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder; Step 3: the silane coupling agent modified FeCoCrMoCBY iron-based amorphous alloy powder is added to the mixed dye wastewater, then H2O2 is added, and the pH is adjusted to 1-7, and the effective degradation of the mixed dye wastewater is realized under the conditions of 35℃ and stirring.

2. The method for improving the effect of treating mixed dye wastewater according to claim 1, characterized in that: The particle size of the FeCoCrMoCBY iron-based amorphous alloy powder is 35-45μm.

3. The method for improving the effect of treating mixed dye wastewater according to claim 1, characterized in that: The mass ratio of the FeCoCrMoCBY iron-based amorphous alloy powder, anhydrous ethanol and silane coupling agent is 3:18:

2.

4. The method for improving the effect of treating mixed dye wastewater according to claim 1, characterized in that: The preparation process of the FeCoCrMoCBY iron-based amorphous alloy powder is as follows: the raw materials Fe, Co, Cr, Mo, C, FeB and Y with a purity of 99.99% are mixed in proportion, then the master alloy is obtained by vacuum arc melting, and then the FeCoCrMoCBY iron-based amorphous alloy powder is obtained by cutting, grinding, vacuum gas atomization and powder screening in sequence; wherein the vacuum arc melting parameters are: voltage is 20 V, current is 300 A, and the mass ratio of Fe, Co, Cr, Mo, C, FeB and Y raw materials is 38.95:26.25:56.25:52.5:56.25:137.3:7.

5.

5. The method for improving the effect of treating mixed dye wastewater according to claim 1, characterized in that: The ultrasonic reaction time is 1-30min.

6. The method for improving the effect of treating mixed dye wastewater according to claim 1, characterized in that: The concentration of H2O2 is 20mmol / L.

7. The method for improving the effect of treating mixed dye wastewater according to claim 1, characterized in that: The pH is preferably 3.

8. The method for improving the effect of treating mixed dye wastewater according to claim 1, characterized in that: The silane coupling agent is 3-aminopropyl triethoxysilane.

9. The method for improving the effect of treating mixed dye wastewater according to claim 1, characterized in that: The stirring speed is 550-600r / min.

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