CN112010486B - Method and system for treating and recycling cotton dyeing waste dye liquor - Google Patents

Abstract

The invention discloses a method for treating and reusing cotton dyeing waste dyeing liquid, which uses electrocoagulation to capture and oxidatively decomposes to completely decolorize the waste dyeing liquid to obtain recovered brine, and further utilizes a concentrating device to distill and concentrate the recovered brine to obtain brine that meets the technological requirements. Saline concentration and distilled water are used in the back dyeing process. According to the treatment requirements of waste dyeing liquid, carry out electrocoagulation, air flotation flocculation, neutralization coagulation, static sedimentation, filtration to remove slag, oxidation decolorization, filtration separation, concentrated distillation procedures to obtain brine that meets the requirements of the dyeing process. Concentration and distilled water are used in the dyeing process, so that the salt content in the waste water is not destroyed, and can be used in the dyeing process, so that the salt and water in the waste dyeing liquid treatment are not discharged, but can be recycled.

Description

A method and system for treating and recycling cotton dyeing waste dyeing liquor

technical field

The invention relates to cotton dyeing waste water treatment and reuse technology, especially for the treatment of high-salt and high-concentration waste dyeing liquid. The waste dyeing liquid is collected by shunting, and the coagulation and sedimentation of the dye in the dyeing liquid is removed, and the residual dye that cannot be removed is oxidatively decomposed. , to achieve complete decolorization technology, to further concentrate the brine concentration that meets the requirements of the dyeing process and to use distilled water in the dyeing process, and to realize the recycling technology of waste dyeing liquid.

Background technique

Cotton dyeing wastewater contains most of the dyes and dye accelerators such as sodium sulfate Na ₂ SO ₄ or sodium chloride NaCl, so removing them for independent treatment can solve most of the wastewater treatment problems. Treatment of COD, and the control of salt discharge is an important issue of environmental protection in the future. Recycling has to be considered. To reuse the waste dyeing liquid, it must be considered that no new substances will be produced after treatment, and the color must be completely removed from damage. Therefore, there must be The slag discharge mechanism of the waste dyeing liquid allows the impurities in the waste dyeing liquid to be captured and removed to realize the feasibility of treatment and reuse.

Waste dyeing liquid is mainly dyeing waste liquid and washing water, which contains more than 95% of residual dyes, leveling agents, dyeing accelerators such as sodium sulfate or sodium chloride and color fixing agents such as sodium carbonate, which are alkaline and highly For COD wastewater, the treatment methods that do not change its composition are:

1. Adsorption method: The most widely used physical treatment method is the adsorption method. This method is to mix activated carbon, clay porous powder or particles with wastewater, or let the wastewater pass through a filter bed composed of its particles, so that The pollutants in the wastewater are adsorbed on the surface of porous substances or removed by filtration. The adsorption rate, BOD removal rate and COD removal rate of activated carbon can reach 93%, 92% and 63% respectively.

2. Chemical oxidation method:

The chemical oxidation method uses strong oxidants to break the chain of dye molecular chromogenic groups to achieve the purpose of decolorization. This method is widely used in the treatment of stable and refractory dyes, including ozone oxidation, Fenton oxidation and high temperature deep oxidation.

Ozone Oxidation Method: Ozone oxidation usually includes two ways, direct reaction and indirect reaction. The direct reaction is that ozone directly reacts with organic pollutants through cycloaddition, electrophile or nucleophile, and the indirect reaction is that ozone reacts with alkali, light, etc. Under the action, free radicals such as hydroxyl (OH) with stronger oxidation ability are generated to destroy the cyclic compounds such as benzene, naphthalene, anthracene and other chromophoric groups to achieve the decolorization effect. The secondary biochemical effluent of printing and dyeing wastewater is treated in depth by ozone oxidation method. Its COD and chroma removal rates are up to 75% and 85% respectively.

Fenton oxidation method: Fenton oxidation method uses hydrogen peroxide (H ₂ O ₂ ) to generate highly reactive OH radicals under the catalysis of ferrous ions (Fe ²⁺ ), and its oxidative properties are not selective. It can react with most organic matter to degrade it. Fenton’s reagent is used to treat the printing and dyeing water of the dyeing factory. Considering the influence of reaction time, ferrous sulfate dosage, hydrogen peroxide dosage and pH value on the chromaticity of wastewater and COD treatment effect, It is found that under the optimal process conditions, the COD removal rate is greater than 80%, and the chroma removal rate is above 95%. Generally, the reaction is under acidic conditions, and the treatment cost is high when the cotton dyeing wastewater is alkaline.

From the above, it can be seen that there are still considerable technical difficulties in the treatment of waste dyeing liquor, the removal rate of color is difficult, it is not easy to realize, and it is difficult to change the composition of brine for reuse. The existing treatment technology is explained as follows:

1. Patent Application No. 201310078136.X A method for treating reactive dye wastewater, which adds 2-8g/L peracetic acid to the reactive dye wastewater, raises the temperature of the wastewater to 90-95°C, and keeps it warm for 25-30min. The oxidized components released by heating peracetic acid destroy the conjugated structure of reactive dyes to achieve effective decolorization. The peracetic acid is a mixture of sulfuric acid, hydrogen peroxide and glacial acetic acid. Although this decolorization method decomposes and destroys the dye, However, its components still exist in the treated water, and the discharge will not cause environmental pollution. Although decolorization and discharge have been achieved, there is no reuse design and no verification of the feasibility of reuse.

2. Patent Application No. 201510075856.X A dyeing method for reactive dye wastewater reuse, characterized in that it comprises the following steps:

(1) Decolorization: According to the chroma of the dyed wastewater, add 5-30g/L of calcium ions or magnesium ions or a mixture of the two to the wastewater for precipitation and decolorization. After the precipitation is completed, centrifuge for 5 minutes, and take the supernatant liquid;

(2) Softening: Add 0-10g/L sodium carbonate to the supernatant of step (1), stir mechanically for 3 minutes, until no precipitation occurs in the waste water, remove residual calcium ions or magnesium ions, centrifuge for 5 minutes, and take supernatant;

(3) neutralization: according to the salt contained in the dyeing waste liquid is sodium chloride or sodium sulfate, add corresponding hydrochloric acid or sulfuric acid to the supernatant in step (2), neutralize the residual sodium carbonate;

(4) salinity measurement: adopt the salinity of the neutralization treatment water of step (3) of salinometer measurement;

(5) Dyeing: In the recycled water, according to the dyeing requirements, use sodium sulfate, sodium chloride or pure water to adjust the salinity, supplement reactive dyes, and use the dyeing methods commonly used for reactive dyes for dyeing.

The calcium ion is Ca0 or Ca(OH) ₂ calcium salt, and the magnesium ion is MgCl ₂ or MgSO ₄ magnesium salt. From the above, the use of calcium and magnesium ions to adsorb and decolorize basically increases the hardness of the water, which is unfavorable for dyeing. After decolorization, a large amount of sludge is formed, which has the risk of secondary pollution, and the wastewater has no diversion treatment. The amount of wastewater is large, and the wastewater contains dyes. There are impurities such as pre-treatment agents, leveling agents, color-fixing agents, softeners, and dissolved substances. There is no removal mechanism, let alone an oxidative decomposition mechanism. There are risks in use, and they cannot be completely captured and removed. There are risks of different salts, and even water-soluble dyes cannot be decolorized through absorption, which will relatively affect the future dyeing process, and a more complete treatment mechanism needs to be developed.

Contents of the invention

The main purpose of the present invention is to establish a new business opportunity for the recycling of waste dyeing liquor; the salt and water in the waste dyeing liquor can be reused; emissions, thereby avoiding environmental pollution, improving the economic benefits of dyeing factories, and creating new business opportunities for recycling in dyeing factories.

Another main purpose of the present invention is to ensure that the reuse of waste dyeing liquor does not affect the dyeing quality; relative requirements are that the components of recycled water must meet the requirements of dyeing applications, and the original required components must not be destroyed and new substances must not be added. Not only must it be able to decompose the dye, but it must also have the effect of removing slag, and can uniformly convert the salt in the waste dyeing liquid into a dyeing accelerator. No other salts should be added, and the leveling agent and influential dyeing metal ions must be removed. substance.

Another main purpose of the present invention is to solve the problem of waste water treatment and discharge; the salt in the waste water will disappear because of no treatment operation, and the excessive salt will affect the ecological environment. Wastewater contains a lot of salt, which will inevitably increase the difficulty of treatment. By diverting the waste dyeing liquid for reuse, more than 90% of the salt in the dyeing factory can be reused, which can meet future environmental protection requirements.

In order to achieve the purpose of the above invention, the reuse of cotton mill wastewater was analyzed and studied, and the process procedures of cotton mills, raw materials used and pollutants formed, and the benefits of possible treatment and reuse were considered, and it was further found that in the overall wastewater, waste dyeing liquid Treatment and reuse is in line with economic benefits, and can improve the treatment efficiency of the dyeing factory. More than 90% of the salts contained in the waste dyeing liquor and more than 95% of the residual dyes are collected through shunting, and a small amount of wastewater treatment can solve the problem of wastewater treatment. The dyeing liquor is treated independently, and a method for the treatment and reuse of cotton dyeing waste dyeing liquor has been specially developed, as shown in Figure 1:

(1) Utilize shunt to collect waste dye liquor;

The waste dyeing liquid can be collected by shunting to eliminate the pre-treatment and post-treatment wastewater, so as to simplify the waste dyeing liquid. The waste dyeing liquid refers to the dyeing liquid for dyeing and its cleaning water. The waste dyeing liquid discharged in the dyeing process accounts for about 20% of the waste water. % or so, containing dyeing accelerators such as sodium sulfate or sodium chloride, leveling agents, dyes and color fixing agents such as sodium carbonate, it is a high-chroma, high-salt wastewater. The more dyes, soda ash, and leveling doses;

(2) Use the electrocoagulation system to treat the insoluble and dissolved pollutants in the waste dyeing liquid, and retain the dye accelerator and color fixing agent;

The electroflocculation system has the functions of electrolysis, capture, coagulation and sedimentation. It releases iron ions to capture leveling agents, dyes and impurities in the waste dyeing liquid, and further converts them into sludge. It is a very efficient treatment solution;

(3) Utilize acid to neutralize sodium carbonate in the waste dyeing liquor, and convert it into a dyeing accelerator;

Cotton dyeing needs to be colored in an alkaline environment, so a large amount of sodium carbonate needs to be invested, while cotton dyeing requires a large amount of sodium salt as a dyeing accelerator, which can be sodium sulfate or sodium chloride, and sulfuric acid can be used to convert sodium carbonate into sodium sulfate

Na ₂ CO ₃ +H ₂ SO ₄ →Na ₂ SO ₄ +CO ₂ +H2O

Convert sodium carbonate to sodium chloride to use hydrochloric acid

Na ₂ CO ₃ +2HCl→2NaCl+CO ₂ +H2O

Through acid-base neutralization, the salt content in the recovered waste dyeing liquid can be made consistent;

(4) Establish hydrogen peroxide deep oxidation technology to decompose and recycle the residual dye in the dye solution to obtain transparent and colorless reclaimed brine;

Recycled waste dyeing liquid can be neutralized to obtain a dyeing accelerator with a consistent composition, and the residual dye must be further removed in order to be effectively recovered. The chromaticity of the recycled dyeing liquid is not high, and it is becoming more and more difficult to remove. The blind spot of technical removal, the chroma needs to be completely removed, which requires higher cost, and hydrogen peroxide can effectively decolorize. In order to solve the problem of decolorization, a hydrogen peroxide deep oxidation technology is specially established to solve the problem of decolorization of recycled dye liquor; hydrogen peroxide is only used for decolorization. The effect is poor, and it often takes a lot of time and 10 hours to more than 1 day to complete, and the residual hydrogen peroxide will also affect the dyeing function. At present, the use of hydrogen peroxide is basically not considered for the reuse of dyeing wastewater, and the cost of hydrogen peroxide is high. , relatively has a great burden. To improve the decolorization function of hydrogen peroxide, the common method is to carry out at a high temperature above 98°C, and the high temperature treatment relatively increases the heat energy loss, and the amount of hydrogen peroxide input is also large, which affects the recovery efficiency; in order to solve the above difficulties, especially Research on the decolorization efficiency of hydrogen peroxide, using activated carbon to catalyze hydrogen peroxide to generate OH free radicals to destroy and decolorize the remaining dyes in the recovered dye solution to obtain transparent brine, and further use activated carbon to absorb decolorization reactants to improve the purity of recovered brine to achieve complete For the purpose of decolorization, the hydrogen peroxide detector is used to measure the change in the amount of decolorization reaction, and the use of color acquisition to track the color change in the reaction process, to establish an effective tracking decolorization reaction measurement mechanism, to achieve an optimized operation plan, especially set up the deep oxidation method of hydrogen peroxide, as shown in Figure 2 , which include:

① Use mobile activated carbon to catalyze the reaction between hydrogen peroxide and dyes to increase the decolorization speed;

The pure hydrogen peroxide decolorization reaction lasts for more than 1 day, which cannot meet the treatment requirements. Therefore, activated carbon is specially added as a reaction catalyst to increase the OH free radical in hydrogen peroxide to accelerate the decolorization reaction, but bubbles will be generated during the reaction, and it is easy to stay in the active state. The contact between the carbons reduces the activated carbon, prevents the decolorization reaction, and affects the decolorization speed. The specially designed agitation device increases the movement of the activated carbon, allowing the air bubbles to move out quickly, and effectively improves the reaction speed. The decolorization reaction can be completed in about 8 hours by using activated carbon alone. The time is still too long and needs further improvement;

② Increase the reaction speed of hydrogen peroxide and dyes by increasing the temperature;

The higher the temperature, the faster the reaction effect of hydrogen peroxide, and the relative increase in hydrogen peroxide and energy consumption, so special tests for different temperature reaction requirements are carried out;

③ Use hydrogen peroxide concentration analysis to track the decolorization reaction process;

Hydrogen peroxide is used for decolorization of recycled dye liquor. The effect of the reaction can be tracked through the detection and tracking of hydrogen peroxide concentration. When hydrogen peroxide is added, the concentration of hydrogen peroxide rises. If the concentration of hydrogen peroxide is not maintained, the decolorization efficiency will increase and the cost of decolorization will be low. Use optimized concentration control to deal with decolorization Reaction, in order to achieve low-cost operation, it is best to deal with the reaction demand and input, and zero residue is the best. To reduce the consumption of hydrogen peroxide, it must be achieved through concentration control;

④ Use the color analyzer to track the effect of decolorization reaction and the basis for dosage control;

During the operation of the decolorization reaction, the color in the water will change. The decolorization reaction path can be known through the color change. Finally, the hydrogen peroxide dosage requirement for each color reaction can be established through the operating experience data. How much hydrogen peroxide is required for treatment? How long is the reaction time? What color will it be? It can clearly track the process, solve the problem of manual operation judgment, and realize the artificial intelligence decolorization operation plan;

⑤ Use reactive carbon to absorb and recover the reactive impurities in the dye solution to ensure the quality of recovered brine;

Activated carbon is a catalytic catalyst, but it is also a good material for impurity adsorption. In the decolorization reaction, activated carbon can absorb the decolorized impurities and remove them from the water, so that the quality of recovered brine is better. When activated carbon absorbs more, its catalytic effect will become worse. , tracked through the reaction time, when the efficiency drops, the activated carbon needs to be renewed after the decolorization is completed, and the activated carbon can be recycled back to the process for utilization.

(5) Utilize the concentration device to concentrate and recover the brine to reach the brine concentration that meets the dyeing requirements and distilled water to be used in the dyeing process;

The recovered brine contains washing water, and its concentration is much lower than the brine concentration required for dyeing. The brine reuse needs to be further concentrated. The recovered brine can be concentrated through MVR (mechanical vapor recompression) concentration equipment, so that the concentrated brine concentration can be used in the dyeing process. The higher the concentrated concentration, the higher the cost required to meet the process requirements. Distilled water can be used in the dyeing process like distilled water;

(6) Use the online detection brine concentration meter and color detector as the verification tool for the control condition of waste dyeing liquid treatment and reuse;

Batch operation is used to control the decolorization treatment steps to ensure the quality of recycling.

In summary, the technical solution of the present application has the following outstanding technical effects:

(1) The chroma effect can be greatly reduced by about 90-95% through electrocoagulation. After treatment, the low chroma recovery dye solution can be obtained by filtration, and the original waste dye solution can have tens of thousands of chroma values. The value is lowered below 5000;

(2) Through the above hydrogen peroxide deep oxidation technology, the ideal reaction temperature is between 35 and 80°C, and the chromaticity is below 5000, the decolorization reaction time can be shortened to 0.2 to 3 hours, and the chromaticity per ton of dye liquor recovered is 800 to 4000 colors The amount of hydrogen peroxide used is between 0.8 and 4kg to complete the decolorization; (3), the concentration and color of the waste dyeing liquid salt change is quite large, through the measurement of the concentration of brine and the acquisition of color, the concentration and color data of the salt water of the waste dyeing liquid are obtained for comparison Analysis, when different salt concentrations and different colors are processed, different conditions will be required. The change of the salt content of the waste dyeing liquid can be clearly understood through the brine concentration meter, and the color type and chroma of the waste dyeing liquid can be clearly understood through the color detector, which can make the treatment Clearer; collect the reaction materials in the treatment process, analyze the optimized treatment plan, and realize a more effective treatment plan. Through the processing of empirical data, it is possible to establish an AI control operation database for the treatment of waste dye liquor in the factory, and effectively improve the feeding and control conditions for waste dye treatment. Set automation to achieve automatic operation goals; for brine reuse, use a brine concentration meter to measure brine reuse deployment, which can meet the requirements of the dyeing process, and can reduce the concentration of recovered brine and improve the efficiency of treatment and reuse;

(4) The decolorization treatment will be different due to the different color and salt content, the control conditions and the amount of hydrogen peroxide will also be different, which cannot be overcome by the consistency condition. Therefore, the decolorization reaction is specially designed as a batch reaction to increase the flexibility of the reaction operation and solve different reactions. Conditions drop, thereby ensuring the consistency of treatment effect and recycling quality.

Description of drawings

Fig. 1, a kind of cotton dyeing waste dye liquor processing and recycling method art roadmap

Figure 2. Composition diagram of hydrogen peroxide deep oxidation method

Figure 3. A specific implementation procedure diagram of a cotton dyeing waste treatment and reuse method and system

Figure 4. A diagram of a cotton dyeing waste treatment and reuse system

Figure 5. Structural diagram of a cotton dyeing waste treatment and reuse system

Explanation of symbols in the figure

10 Electrocoagulation capture reaction system E10 Electrocoagulation device SV10 Waste dye solution valve

system

20 Decolorization reaction system G10 Blower SV11 Electrocoagulation output valve

30 Concentrated distillation system T10 Waste dye liquor collection tank SV12 Acid outlet valve

11 Waste dye solution T11 Electrocoagulation reaction tank SV13 Coagulant output valve

12 Acid dosing device T12 Aeration tank SV14 Neutralization output valve

13 Coagulant dosing device T13 Neutralization reaction tank SV15 Recovery dye solution valve

14 Compressed air T14 Static settling tank SV16 Sludge outlet valve

15 Sludge T15 Recycling dye solution tank SV17 Filtration and slag removal valve

16 Recycling dye liquor T16 Sludge thickening tank SV18 Filter dye liquor valve

18

1 Recovery dye liquor filter 2 T21 3 Decolorization reaction tank 4 SV21 5 Activated carbon outlet control valve

6 19 7 Plate and frame filter press 8 T22 9 Recovery tank 10 SV22 11 Recovery water filter valve

12 21 13 Activated carbon filter 14 T31 15 Distilled water tank 16 SV25 17 Recovered brine output

valve

18 22 19 Remove charcoal 20 T32 21 Salt water tank 22 SV26 23 Hydrogen peroxide dosing valve

24 23 25 Activated carbon inlet 26 H 27 Holding heater

24 color detector M10 neutralizing mixer

25 Hydrogen peroxide detector M20 Decolorization mixer

26 Hydrogen peroxide dosing device P10 Waste dye pump

27 Decolorization sampling device P11 Aeration pump

28 Recovery brine P12 Recovery filter pump

29 Recovery brine filter P13 Sludge filter pump

31 MVR Concentrator P14 Filtrate Pump

32 Brine Concentration Meter P20 Return Pump

33 Brine outlet P21 Decolorization output filter pump

34 Distilled water outlet P22 Recovery water pump

35 Concentrated brine P31 Distilled water pump

36 distilled water P32 brine pump

Detailed ways

A kind of implementation program of cotton dyeing waste dyeing liquor treatment recycling method, as shown in Figure 2, its concrete procedure comprises:

(1) Waste dye liquor diversion collection procedures;

The waste dyeing liquid discharged from the cotton dyeing equipment is separately collected and processed in a centralized manner. The components of the waste dyeing liquid include dyes, leveling agents, dyeing accelerators, color fixing agents and water. After mixing and collecting, the color will vary according to the requirements of the dyeing process. The dyeing accelerator generally uses sodium sulfate or sodium chloride, the color fixing agent is sodium carbonate, and there are no other raw materials, and the ingredients are relatively simple;

(2) Electrocoagulation capture program;

Electrocoagulation is used to treat waste dyeing liquid. Electrocoagulation has the functions of electrolysis, capture and coagulation. The related impurities of soluble and insoluble substances in waste dyeing liquid are captured through the release of iron ions. Leveling agents and dyes can capture and settle. , and retain the ingredients of dye accelerator and color fixing agent;

(3) Air flotation and condensation procedures;

The waste dye solution after electrocoagulation is further introduced into a large amount of air through the blower, so that the divalent iron ion Fe2+ released by the electrode is converted into trivalent Fe3+ iron ion to obtain an effective sedimentation function, so that the iron ion can be precipitated and insoluble in water, which can avoid post-treatment Iron ion residue;

(4) neutralization coagulation procedure;

Through acid-base neutralization, the sodium carbonate in the waste dyeing liquid is converted into sodium sulfate or sodium chloride, so that the salt in the water forms a single salt and can be reused in the process, and the coagulant is further used to make the impurities in the waste dyeing liquid easier to combine , forming larger molecules that can settle rapidly;

(5) Static settlement procedure;

Let the waste dyeing liquid stand still after neutralization and coagulation, and let the pollutants in the water combine and precipitate into sludge;

(6) Filtration removal procedure;

Use the recycled dye solution filter to filter the waste dye solution after standing still, and the recycled dye solution can be obtained. The impurities in the sludge part will stay on the plate and frame filter press and be removed. The filtered recycled water can remove about 95% of the dye , can reduce follow-up costs;

(7) Oxidative decolorization procedure;

The recovered dye liquor is further applied to the hydrogen peroxide deep oxidation technology, and the hydrogen peroxide is catalyzed by activated carbon to decompose and decolorize all the dyes;

(8) Decolorization inspection program;

The decolorization inspection program is the core of decolorization control. Through the hydrogen peroxide detector and color detector, you can clearly understand the decolorization operation status, the amount of hydrogen peroxide input and the timing of input to fully control the decolorization effect. When the decolorization is not complete, you need to go back to the oxidation program. When the standard is reached, it is possible to enter the next program operation;

(9) Filtration and separation procedures;

When the oxidation decolorization procedure is completed and the decolorization inspection procedure is confirmed, the recovered dye solution in the decolorization reaction tank can be further filtered and separated, and the activated carbon in the water can be removed to obtain transparent and colorless recovered water;

(10) Concentrated steaming procedure;

Concentrate the transparent and colorless recovered water with salt water, increase the concentration of salt water to reach the concentration required in the dyeing process, and introduce the concentrated distilled water into the distilled water tank to wait for the supply of cotton dyeing equipment;

(11) Salt concentration testing procedure;

The concentrated brine is further inspected with a brine concentration meter. When the concentration reaches the required concentration, the concentrated brine is introduced into the concentrated brine recovery tank for storage, and waits for the application of cotton dyeing equipment.

Through the above procedures, the waste dyeing liquid treatment and reuse method of cotton dyeing can be realized, and the waste dyeing liquid recycling target can be easily achieved. In order to realize the above method, a waste dyeing liquid treatment and reuse system has been specially established, as shown in Figure 4 and Figure 5. Its contents include:

(1) Electrocoagulation capture treatment system;

10 The electrocoagulation capture treatment system consists of T10 waste dyeing liquid collection tank, T11 electrocoagulation reaction tank, T12 aeration tank, T13 neutralization reaction tank, T14 static settling tank, T16 sludge concentration tank, and 18 recycling dye liquid filter , T15 recovery dye solution tank and 19 plate and frame filter press devices; the waste dye solution discharged from cotton dyeing equipment is collected through the T10 waste dye solution collection tank, and the T10 waste dye solution collection tank is passed through the P10 waste dye solution pump and the SV10 waste dye solution The liquid valve is connected with the T11 electrocoagulation reaction tank, which can introduce the waste dyeing liquid into the electrocoagulation equipment for electrocoagulation operation. The T11 electrocoagulation reaction tank is connected with the T12 aeration tank through the SV11 electrocoagulation output valve, and the waste dyeing liquid after electrocoagulation can be Introduce T12 aeration tank, under the T12 aeration tank, there is an aeration device, which can introduce 14 compressed air through the G10 blower to make the waste dyeing liquid agitate and oxidize and condense. The T12 aeration tank reacts with T13 through the P11 aeration pump. The tanks are connected, and the waste dyeing liquor after aeration can be introduced into the T13 neutralization reaction tank. Above the T13 neutralization reaction tank, there are M10 neutralization mixer, 12 acid dosing device, SV12 acid output valve, and 13 coagulant dosing device. And the SV13 coagulant output valve device, which can stir and neutralize the waste dyeing liquid after aeration, start the 12 acid dosing device and the SV12 acid output valve, introduce acid to neutralize the sodium carbonate in the waste dyeing liquid, and put it Converted into dyeing accelerator, after neutralization, start 13 coagulant dosing device and SV13 coagulant output valve, introduce coagulant into the neutralization waste dyeing liquid, T13 neutralization reaction tank and T14 through SV14 neutralization output valve The static settling tank is connected, and the waste dyeing liquid after the neutralization reaction can be introduced into the T14 static settling tank for coagulation and sedimentation, and the leveling agent, dye and impurities in the waste dyeing liquid are converted into sludge for static settling, and T14 static settling The side of the tank passes through the P12 recovery filter pump and the 18 recovery dye solution filter. The outlet of the 18 recovery dye solution filter is connected to the T15 recovery dye solution tank through the SV18 filter dye solution valve. The T16 sludge thickening tank is connected, the 18 recycled dyeing liquid filter is connected with the T16 sludge thickening tank through the SV17 filter deslagging valve, the T16 sludge thickening tank is connected with the 19 plate and frame filter press through the P13 sludge filter pump, and the 15 The sludge is filtered out, and the filtered water can be connected to the T15 recovery dye solution tank by using the P14 filtrate pump, and the T15 recovery dye solution tank is connected to the 20 decolorization reaction system through the SV15 recovery dye solution valve;

(2) Decolorization reaction system;

20 decolorization reaction system is composed of T21 decolorization reaction tank, 21 activated carbon filter, 29 recovery brine filter, 26 hydrogen peroxide dosing device, 27 decolorization sampling device and T22 recovery water tank; The T15 recovery dye solution tank of the 10 electrocoagulation capture reaction system in the front section is connected to receive the 16 recovery dye solution treated by the 10 electrocoagulation capture reaction system, and the SV21 activated carbon outlet control valve and 21 activated carbon filter are installed under the T21 decolorization reaction tank Connected to filter out the active carbon after use, and the residual liquid can be led back to the T21 decolorization reaction tank through the P20 reflux pump for decolorization reaction. There is a H constant temperature heater on the side of the T21 decolorization reaction tank to maintain the reaction temperature. There is a cover on the top To reduce heat loss, there are 23 activated carbon input ports, M20 decolorization mixer, 26 hydrogen peroxide dosing device, 27 decolorization sampling device on the top, so that 16 recovered dye liquor can undergo decolorization reaction, and there is an outlet on the side of T21 decolorization reaction tank, which can be decolorized through P21 The output filter pump is connected with the 29 recovered brine filter, and the outlet of the filter is connected with the T22 recovered water tank through the SV25 recovered brine output valve, and the 28 recovered brine is introduced into the T22 recovered water tank, and its rear end is connected with the 30 concentrated distillation system; the 26 hydrogen peroxide dosing device is set Above the T21 decolorization reaction tank, the 26 hydrogen peroxide dosing device introduces the amount of hydrogen peroxide into the T21 decolorization reaction tank through the SV26 hydrogen peroxide dosing valve. The detector then flows back into the T21 decolorization reaction tank. The residual amount of hydrogen peroxide is known through the 25 hydrogen peroxide detector, and the decolorization status of the recovered dye solution is checked through the 24 color detector to check the amount of hydrogen peroxide used. The color change in the reaction process can be clearly understood. The 24 color detector can be used for Digital cameras, digital cameras or spectrometers are used to obtain the color of wastewater and track the color change path of waste dyeing liquid treatment;

(3) concentrated distillation system;

The 30 concentration distillation system is composed of 31MVR concentration equipment, T31 distilled water tank and T32 brine tank; the front section is introduced into the 31MVR concentration equipment through the P22 recovery water pump, and the 31MVR concentration equipment has a 33 brine outlet to lead 35 concentrated brine to the T32 brine tank, which can be passed through the P32 brine pump Transported to the dyeing machine, the 31MVR concentration equipment also has 34 distilled water outlets, which can lead the 36 distilled water to the T31 distilled water tank, and can be transported to the dyeing machine through the P31 distilled water pump.

Through 10 electrocoagulation capture treatment systems, 20 decolorization reaction systems and 30 concentration distillation systems, the waste dyeing liquor treatment and reuse system can be formed.

The working principle of the waste dye solution recycling system of this application is as follows:

The dyeing process of cotton dyeing equipment separates the waste dyeing liquid, which is collected through the T10 waste dyeing liquid collection tank, and further uses the P10 waste dyeing liquid pump to introduce the 11 waste dyeing liquid into the T11 electrocoagulation reaction tank through the SV10 waste dyeing liquid valve for electrocoagulation operation. Use the E10 electrocoagulation device to perform electrocoagulation in the T11 electrocoagulation reaction tank. During electrocoagulation, the electrode plate will release ferrous ions Fe2+ to allow dyes, leveling agents and impurities to coagulate. After the electrocoagulation operation, the SV11 electrocoagulation The output valve is introduced into the T12 aeration tank, and then the G10 blower is used to introduce 14 compressed air for oxidation, so that the ferrous ion Fe2+ is converted into the ferric ion Fe3+ that can settle, and after 1 to 2 hours of conversion, start the P11 aeration Pump to introduce the waste dyeing liquid into the T3 neutralization reaction tank for neutralization and flocculant addition operations. Before neutralization, start the M10 neutralization mixer to stir and measure the pH value of the waste dyeing liquid, and then control the amount of acid added by the pH value. Use the 12 acid dosing device and the SV12 acid output valve to introduce acid for neutralization. After the neutralization is completed, the next step is to add coagulant. Through the 13 coagulant dosing device and the SV13 coagulant output valve, the coagulation The agent is introduced into the T13 neutralization reaction tank for coagulation operation. After the coagulation is completed, the SV14 neutralization output valve is further opened, and the waste dyeing liquid in the T13 neutralization reaction tank is introduced into the T14 static settlement tank for static settlement operation. After 1 ~ 3 hours to stand still, let most of the dyes, leveling agents and impurities in the waste dyeing liquid combine and precipitate to form sludge; turn on the P12 recovery filter pump, introduce the waste dyeing liquid into the 18 recovery dyeing liquid filter to stop the sludge impurities , the outlet is connected to the SV18 filter dyeing liquid valve to obtain 16 recycled dyeing liquids, which can be introduced into the T15 recycling dyeing liquid tank to complete the electrocoagulation capture reaction operation; most of the sludge in the T14 static settling tank will settle to the bottom, when the amount of sludge accumulates Open the lower SV16 sludge outlet valve to introduce the sludge into the T16 sludge thickening tank for temporary storage. The slag discharge outlet of the above-mentioned 18-recycled dyeing liquid filter can intercept the sludge impurities by the 18-recycled dyeing liquid filter through the SV17 filter and slag removal valve Introduce the T16 sludge thickening tank. When the volume of the T16 sludge thickening tank is large, use the P13 sludge filter pump to introduce the sludge from the T16 sludge thickening tank into the 19 plate and frame filter press, press out the 15 sludge, and press out the filtrate It can be introduced into the T15 recovery dye solution tank through the P14 filtrate pump for reuse.

Next, the decolorization reaction operation is carried out. Use the SV15 recovery dye liquor valve to introduce the recycled dye liquor into the T21 decolorization reaction tank. The T21 decolorization reaction tank needs to be filled with activated carbon in advance, and can be put into the T21 decolorization reaction tank through the 23 activated carbon inlet. About 0.5-5kg/T is used as a catalyst. After the recycled dyeing liquor is filled, turn on the M20 decolorizing mixer to further heat and keep the recycled dyeing liquor, and keep the recycled dyeing liquor at 35-80°C through the H insulation heater, and wait for the heating to complete After that, the 27 decolorization sampling device is further used to further use the 24 color detector to understand the color information of the recovered dye solution, and further use the color dosing database to obtain the oxidant input information. The color dosing database is established according to the operating experience data, and the dosing needs to be set in advance Quantity and reaction time, color information of reaction completion; using 25 hydrogen peroxide detector, can detect the ratio of input hydrogen peroxide, you can get decolorization reaction, after the hydrogen peroxide detector judges that the reaction is completed, that is, when the hydrogen peroxide drops to the set value, then carry out 24 colors Detector to see the decolorization effect. By sampling the color, it can be clear whether the oxidant input in the early stage is within the control range. Once again, the color dosing database information is used to carry out the decolorization reaction procedure. It needs to be put into the oxidant reaction many times until it meets the set requirements. , to determine the completion of the decolorization process; through the input of hydrogen peroxide and the reaction time speed, it can be known whether the catalytic ability of the activated carbon is normal. When the activated carbon absorbs too many impurities, the reaction rate will be affected, and the activated carbon will need to be updated to ensure the decolorization reaction process. Normal operation; when the decolorization is completed, turn on the P21 decolorization output filter pump and the SV22 recovery water filter valve, introduce the 16 recovery dye solution into the T22 recovery tank after decolorization and filter it through the 29 recovery brine filter, and the filtered 28 recovery brine is recovered through the SV25 The brine output valve is introduced into the T22 recovery tank, and then the next decolorization reaction is carried out; in addition, when the catalytic capacity of the activated carbon decreases and the decolorization time is prolonged, the activated carbon operation needs to be renewed. After the decolorization is completed and the recovered water is filtered, further cleaning and recovery After the water filter, open the SV21 activated carbon outlet control valve below the T21 decolorization reaction tank, and introduce the residual water and activated carbon in the T21 decolorization reaction tank into the 21 activated carbon filter. After completion, close the SV21 activated carbon outlet control valve. 22 remove the activated carbon, further lead the excess water back to the T21 decolorization reaction tank through the P20 reflux pump, and then introduce new activated carbon from the 23 activated carbon input port to complete the activated carbon renewal operation. The 28 brine that flows into the T22 recovery water tank is introduced into the 31MVR concentration equipment through the P22 recovery water pump for concentration operation, and 35 concentrated brine and 36 distilled water can be obtained, which are introduced into the T32 brine tank through the 33 brine outlet, and can be passed through the 32 brine concentration meter in the brine tank Detect the concentration of 35 concentrated brine, and further use the P32 brine pump to lead back to the dyeing machine to provide the dyeing process for deployment, while the 36 distilled water is led to the T31 distilled water tank through the 34 distilled water outlet, and the P31 distilled water pump can be used to lead the 36 distilled water to the dyeing machine to provide the dyeing process use.

Claims (4)

1. A kind of cotton dyeing waste dye liquor treatment recycling method, its content comprises: (1) Utilize shunt to collect waste dye liquor; The waste dyeing liquid is collected separately by shunting, eliminating pre-treatment and post-treatment wastewater, and simplifying the waste dyeing liquid. The waste dyeing liquid refers to the dyeing liquid for dyeing and its cleaning water. The waste dyeing liquid discharged in the dyeing process accounts for 20% of the wastewater. %, containing dyeing accelerator, leveling agent, dyestuff and color-fixing agent, the above-mentioned dyeing accelerator is sodium sulfate or sodium chloride, and the color-fixing agent is sodium carbonate; (2) Use the electrocoagulation system to treat the insoluble and dissolved pollutants in the waste dyeing liquid, and retain the dye accelerator and color fixing agent; The electroflocculation system has the functions of electrolysis, capture, coagulation and sedimentation. It releases iron ions to capture the leveling agent, dyes and impurities in the waste dyeing liquid, and further converts them into sludge precipitation, which greatly reduces the color by 90-95%. The low chroma recovery dye solution is obtained by filtration, and the tens of thousands of chroma values of the original waste dye solution are reduced to less than 5000; (3) Utilize acid to neutralize soda ash in the waste dyeing liquor, and convert it into a dyeing accelerator; Cotton dyeing needs to be colored in an alkaline environment, so a large amount of sodium carbonate needs to be invested, while cotton dyeing requires a large amount of sodium salt as a dyeing accelerator, which is sodium sulfate or sodium chloride, and soda ash is converted into sulfuric acid through acid-base neutralization Sodium or sodium chloride, let the salt in the waste dyeing liquid form a consistent dye accelerator, which is easy to return to the process for utilization. The reaction formula of this process is: Na ₂ CO ₃ +H ₂ SO ₄ →Na ₂ SO ₄ +CO ₂ +H2O; _{Na2CO3 +} 2HCl→2NaCl+ _CO2 +H2O; (4) adopt hydrogen peroxide deep oxidation technology to decompose and recycle the residual dyestuff in the dye liquor, and obtain transparent and colorless reclaimed brine; Activated carbon is used to catalyze hydrogen peroxide to generate OH free radicals to destroy and decolorize the remaining dyes in the recovered dye solution to obtain transparent recovered brine, and further use activated carbon to absorb decolorized reactants to improve the purity of recovered brine to achieve complete decolorization reaction, which is measured by hydrogen peroxide detector Changes in the amount of decolorization reaction, and use color acquisition to track the color change in the reaction process, establish an effective tracking decolorization reaction measurement mechanism, and achieve optimal operation; (5) Utilize the concentrating device to concentrate and recover the brine to achieve the brine concentration that meets the dyeing requirements and the purpose of distilled water back to the dyeing process; The recovered brine contains cleaning water whose concentration is much lower than the brine concentration required for dyeing, so the brine reuse needs to be further concentrated, and the recovered brine is concentrated through MVR, so that the concentration of the concentrated brine meets the requirements of the dyeing process; (6) Use the on-line detection brine concentration meter and color detector as a verification tool for the control conditions of waste dyeing liquid treatment and reuse; The salt concentration and color of the waste dyeing liquid vary greatly. The salt water concentration and color information of the waste dyeing liquid can be obtained through the salt water concentration measurement and color acquisition for comparison and analysis. It is necessary to process the waste dyeing liquid with different salt concentrations and different colors. Different conditions; through the salt water concentration meter, the change of the salt content of the waste dyeing liquid can be clearly understood, and the color type and chroma of the waste dyeing liquid can be clearly understood through the color detector, so that the processing data can be more clearly distinguished, the materials used in the reaction process can be collected, and the optimal treatment can be analyzed The scheme can realize the most effective treatment plan. Through the processing experience data, establish the AI control operation database of the factory waste dyeing liquid treatment, effectively improve the automation of waste dyeing liquid treatment feeding and control condition setting, and realize the goal of automatic operation; for the reuse of brine , Use the brine concentration meter for brine reuse deployment, accurately recover the concentration of brine, and improve the efficiency of treatment and reuse; (7) Use batch operation to control the decolorization process steps to ensure the quality of recycling; The decolorization treatment will be different due to different colors, different salt contents, control conditions and hydrogen peroxide dosage, which cannot be overcome through consistency. Therefore, the decolorization reaction is designed as a batch reaction to increase the flexibility of the reaction operation, solve the gap between different reaction conditions, and ensure the treatment Consistency of effect and recovery quality. 2. the cotton dyeing waste dye liquor treatment recycling method as claimed in claim 1, its implementation program specifically comprises the following steps: (1) Waste dye liquor diversion collection procedures; The waste dyeing liquid discharged from the cotton dyeing equipment is separately collected and concentrated for treatment. The composition of the waste dyeing liquid contains dyes, leveling agents, dyeing accelerators, color fixing agents, soda ash and water. After mixing and collecting, the color will change with the dyeing process. The process requirements have changed, and the dyeing accelerator generally uses sodium sulfate, and the color fixing agent soda ash is sodium carbonate. There are no other raw materials, and the ingredients are relatively simple; (2) Electrocoagulation capture program; Electrocoagulation is used to treat waste dyeing liquid. Electrocoagulation has the functions of electrolysis, capture and coagulation. The related impurities of soluble and insoluble substances in waste dyeing liquid are captured through the release of iron ions. Leveling agents and dyes can capture and settle. And retain sodium sulfate and sodium carbonate; (3) Air flotation and condensation procedures; The waste dyeing solution after electrocoagulation is further introduced into a large amount of air through the blower, so that the divalent iron ions Fe ²⁺ released by the electrodes are converted into trivalent Fe ³⁺ iron ions to obtain an effective sedimentation function, so that the iron ions can be precipitated and insoluble in water. Avoid iron ion residue; (4) neutralization coagulation procedure; Neutralize the acid-base with sulfuric acid or hydrochloric acid to convert the sodium carbonate in the waste dyeing liquid into sodium sulfate or sodium chloride, so that the salt in the water can be reused in the process, and further use coagulant to make the impurities in the waste dyeing liquid more concentrated. Easy to combine to form larger molecules that can settle quickly; (5) Static settlement procedure; Let the waste dyeing liquid stand still after neutralization and coagulation, and let the pollutants in the water settle and combine into sludge; (6) Filtration removal procedure; Use the recycled dye solution filter to filter the waste dye solution after standing still to obtain the recycled dye solution. The impurities in the sludge part will stay on the plate and frame filter press and be removed. The filtered recycled water can remove up to 95% of the dye ; (7) Oxidative decolorization procedure; The hydrogen peroxide deep oxidation technology is further applied to the recycled dye liquor, and the hydrogen peroxide is catalyzed by activated carbon to decompose and decolorize all the dyes, which can effectively remove the color of the recycled dye liquor; (8) Decolorization inspection procedure; The decolorization inspection program is the core of decolorization control. Through the hydrogen peroxide detector and color detector, the decolorization operation status, the amount of hydrogen peroxide input and the timing of input are clear, and the decolorization effect is fully controlled. When the standard is met, go to the next step; (9) Filtration and separation procedures; After the completion of decolorization is confirmed by the decolorization inspection procedure, the dye solution recovered in the decolorization reaction tank is further filtered and separated, and the activated carbon in the water is removed to obtain transparent and colorless recovered brine; (10) Concentrated steaming procedure; Concentrate the transparent and colorless recovered brine to increase the concentration of the brine to meet the requirements of the dyeing process, while the concentrated distilled water is introduced into the distilled water tank to be supplied to the needs of cotton dyeing equipment; (11) Salt concentration testing procedure; The concentrated brine is further inspected with a brine concentration meter, and when the concentration is met, the concentrated brine is introduced into the concentrated brine recovery tank to be supplied to the needs of cotton dyeing equipment. 3. The cotton dyeing waste dye liquor treatment and reuse method as claimed in claim 1, wherein the content of the hydrogen peroxide deep oxidation technology comprises: (1) Use mobile activated carbon to catalyze the reaction between hydrogen peroxide and dyes to increase the decolorization speed; Activated carbon is added as a reaction catalyst to increase the OH free radical in hydrogen peroxide to accelerate the decolorization reaction, but it will generate bubbles during the reaction, which are easy to stay in the activated carbon to reduce the contact of activated carbon and prevent the decolorization reaction. Move, let the bubbles move out quickly, effectively improve the reaction speed; (2) Utilize temperature rise to increase the reaction speed of hydrogen peroxide and dye; The higher the temperature, the faster the reaction effect of hydrogen peroxide, but it will relatively increase the consumption of hydrogen peroxide and energy. Through the verification of different temperatures, the ideal reaction temperature is between 35 and 80°C, and the reaction time is shortened to 0.2 to 3 hours when the chroma is below 5000. completed within (3) Utilize hydrogen peroxide concentration analysis to track the decolorization reaction process; Recycled dyeing solution is oxidized and decolorized by hydrogen peroxide, and the concentration of hydrogen peroxide is used to detect and track the reaction effect. When hydrogen peroxide is added, the concentration of hydrogen peroxide rises. Instead of maintaining a high concentration, the decolorization efficiency will increase and the cost of decolorization will be low. Use the optimal concentration for decolorization reaction , in order to achieve low-cost operation, when the reaction demand is equal to the input amount is zero residue, to reduce the consumption of hydrogen peroxide must be achieved through concentration control; (4) Utilize the color analyzer to track the effect of decolorization reaction and the basis for dosage control; The color of the water in the decolorization reaction process will change, and the decolorization reaction path can be known through the color change, and finally the amount of hydrogen peroxide required for each color reaction, the reaction time and what color will be established through accumulated operating experience; clear tracking, to solve the problem of manual operation judgment , realize the artificial intelligence decolorization operation plan; (5) Utilize activated carbon to absorb and recover the reactive impurities in the dye liquor to ensure the quality of recovered brine; Activated carbon is a catalytic catalyst, but it is also a good material for impurity adsorption. In the decolorization reaction, activated carbon will absorb the decolorized impurities and remove them from the water to make the recovered brine quality better. When activated carbon absorbs more, its catalytic effect will become worse. Through reaction time tracking, when the efficiency slows down, the activated carbon needs to be renewed after the decolorization reaction is completed, and the activated carbon is recycled back to the process for utilization. 4. A waste dyeing liquor treatment and recycling system, which includes: (1) Electrocoagulation capture treatment system; The electrocoagulation capture treatment system consists of a waste dyeing liquid collection tank, an electroflocculation reaction tank, an aeration tank, a neutralization reaction tank, a static settling tank, a sludge concentration tank, a recovery dye solution filter, a recovery dye solution tank and a plate frame The filter press device is composed of; the waste dyeing liquid discharged from the cotton dyeing equipment is collected through the waste dyeing liquid collection tank, and the waste dyeing liquid collection tank is connected with the electroflocculation reaction tank through the waste dyeing liquid pump and the waste dyeing liquid valve, and the waste dyeing liquid is collected Introduce electrocoagulation equipment for electrocoagulation operation, the electrocoagulation reaction tank is connected with the aeration tank through the electrocoagulation output valve, and the waste dyeing liquid after electrocoagulation is introduced into the aeration tank, and an aeration device is installed under the aeration tank to introduce compressed air through a blower Let the waste dyeing liquid produce agitation and oxidation condensation function, the aeration tank is connected with the neutralization reaction tank through the aeration pump, and the aerated waste dyeing liquid is introduced into the neutralization reaction tank, and a neutralization mixer is installed above the neutralization reaction tank , acid dosing device and acid output valve, coagulant dosing device and coagulant output valve device, agitate and neutralize the waste dyeing liquid after aeration, start the acid dosing device and acid output valve, introduce acid Neutralize the sodium carbonate in the waste dyeing liquid and convert it into a dyeing accelerator. After neutralization, start the coagulant dosing device and the coagulant output valve, introduce the coagulant into the neutralizing waste dyeing liquid, and neutralize the reaction tank The neutralization output valve is connected with the static settling tank, and the waste dyeing liquid after the neutralization reaction is introduced into the static settling tank for coagulation and sedimentation, and the leveling agent, dye and impurity conversion sludge in the waste dyeing liquid are statically settled, and static The side of the settling tank is connected to the recovery dye solution filter through the recovery filter pump, the outlet of the recovery dye solution filter is connected to the recovery dye solution tank through the filter dye solution valve, and the sludge concentration tank is connected to the sludge concentration tank through the sludge outlet valve under the settling tank The recovery dyeing liquid filter is connected to the sludge thickening tank through the filter deslagging valve, the sludge thickening tank is connected to the plate and frame filter press through the sludge filter pump, and the sludge is filtered out, and the filtered water is connected to the filter by the filtrate pump. The recovery dye solution tank is connected, and the recovery dye solution tank is connected with the decolorization reaction system through the recovery dye solution valve; (2) Decolorization reaction system; The decolorization reaction system is composed of a decolorization reaction tank, an activated carbon filter, a recovery brine filter, a hydrogen peroxide dosing device, a decolorization sampling device and a recovery water tank; The liquid tank is connected to receive the recovered dye liquor after being treated by the electrocoagulation capture treatment system. An activated carbon outlet control valve is installed under the decolorization reaction tank to connect with the activated carbon filter. After filtering out the activated carbon for use, the residual liquid passes through the return pump. Bring it back to the decolorization reaction tank for decolorization reaction. A constant temperature heater is installed on the side of the decolorization reaction tank to maintain the reaction temperature. A cover is installed on the top to reduce heat loss. The top is equipped with an activated carbon input port, a decolorization mixer, a hydrogen peroxide dosing device, and a decolorization sampling The device allows the recovered dyeing liquid to undergo decolorization reaction. There is an outlet on the side of the decolorization reaction tank, which is connected to the recovery brine filter through the decolorization output filter pump. The filter outlet is connected to the recovery tank through the recovery brine output valve, and the recovered brine is introduced into the recovery tank , its rear end is connected to the concentrated distillation system; the hydrogen peroxide dosing device is set above the decolorization reaction tank, the hydrogen peroxide dosing device introduces the amount of hydrogen peroxide into the decolorization reaction tank through the hydrogen peroxide dosing valve, and the decolorization sampling device extracts the dye liquor from the decolorization reaction tank. The hydrogen peroxide detector and color detector flow back into the decolorization reaction tank. The residual amount of hydrogen peroxide can be known through the hydrogen peroxide detector, and the decolorization status of the recovered dye solution can be checked through the color detector and the amount of hydrogen peroxide. The color change in the reaction process can be clearly understood. The color detector is digital Video camera, digital camera or spectrometer to obtain the color of wastewater, and track the color change path of waste dyeing liquid treatment; (3) concentrated distillation system; The concentration distillation system is composed of MVR concentration equipment, distilled water tank and brine tank; the front section is introduced into the MVR concentration equipment through the recovery water pump, and the MVR concentration equipment has a brine outlet to lead the concentrated brine to the brine tank, which is transported to the dyeing machine for reuse through the brine pump, and the MVR concentration The equipment also has a distilled water outlet, which leads the distilled water to the distilled water tank, and sends it to the dyeing machine for reuse through the distilled water pump.

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