Recycling system for dyeing saline water

Abstract

The utility model discloses a dyeing saline water recycling system. The system comprises an adjusting tank, a decarburization tank, an electrochemical reactor, a dechlorination tank, a tail gas absorption tower and a neutralization tank, a dyeing brine outlet of the adjusting tank is connected to a dyeing brine inlet of the decarburization tank; a dyeing brine outlet of the decarburization tank is connected to a dyeing brine inlet of the electrochemical reactor; a dyeing brine outlet of the electrochemical reactor is connected to a dyeing brine inlet of the dechlorination tank; a tail gas outlet of the dechlorination tank is connected to a tail gas inlet of the tail gas absorption tower; a dyeing brine outlet of the dechlorination tank is connected to a dyeing brine inlet of the neutralization tank; and the treated dyeing saline water outlet of the neutralization tank outputs dyeing saline water for reuse. The dyeing brine recycling system has the advantages of low operation cost, simplicity in operation, no pollutant generation and the like.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of environmental protection and resource recycling technology, and specifically relates to a dyeing salt water recycling system. BACKGROUND

[0002] A large amount of sodium chloride is usually used in printing and dyeing process to promote dyeing, and the COD content in dyeing wastewater is also high, so it is very economical and environmentally beneficial to treat and recycle the dyeing wastewater. At present, the recycling methods of dyeing wastewater with high sodium chloride content (also known as dyeing salt water) mainly include extraction method, membrane separation method and Fenton method. However, the operation cost of these methods is usually high, and the process flow is complex, and pollutants such as concentrated water are also produced.

[0003] Therefore, it has become one of the problems to be solved in the field to develop a dyeing salt water recycling system with low operation cost, simple operation and no pollutants. UTILITY MODEL CONTENT

[0004] To solve the above technical problems, the utility model aims at providing a dyeing salt water recycling system. The dyeing salt water recycling system has the advantages of low operation cost, simple operation and no pollutants.

[0005] In order to achieve the above purpose, the utility model provides a dyeing salt water recycling system, which comprises an adjusting tank, a decarburization tank, an electrochemical reactor, a dechlorination tank, a tail gas absorption tower and a neutralization tank.

[0006] The adjusting tank is provided with at least a dyeing salt water outlet, the decarburization tank is provided with at least a dyeing salt water inlet, an acid inlet, a first aeration assembly and a dyeing salt water outlet, the electrochemical reactor is provided with at least a dyeing salt water inlet and a dyeing salt water outlet, the dechlorination tank is provided with at least a dyeing salt water inlet, a second aeration assembly, a tail gas outlet and a dyeing salt water outlet, the tail gas absorption tower is provided with at least a tail gas inlet, an absorption liquid inlet, an absorption liquid outlet and a purified tail gas outlet, and the neutralization tank is provided with at least a dyeing salt water inlet, an alkali inlet and a treated dyeing salt water outlet.

[0007] The dyeing salt water outlet of the adjusting tank is connected to the dyeing salt water inlet of the decarburization tank; the dyeing salt water outlet of the decarburization tank is connected to the dyeing salt water inlet of the electrochemical reactor; the dyeing salt water outlet of the electrochemical reactor is connected to the dyeing salt water inlet of the dechlorination tank; the tail gas outlet of the dechlorination tank is connected to the tail gas inlet of the tail gas absorption tower; the dyeing salt water outlet of the dechlorination tank is connected to the dyeing salt water inlet of the neutralization tank; and the treated dyeing salt water outlet of the neutralization tank outputs the dyeing salt water for recycling.

[0008] According to the specific embodiment of the utility model, preferably, the adjusting pool is further provided with a dyed brine circulation outlet and a dyed brine circulation inlet, the dyed brine circulation outlet is connected to the absorption liquid inlet of the tail gas absorption tower, the absorption liquid outlet of the tail gas absorption tower is connected to the dyed brine circulation inlet, and the dyed brine in the adjusting pool is used as absorption liquid to absorb chlorine in tail gas to obtain purified tail gas, and the absorption liquid after absorbing chlorine in the absorption tail gas is circulated to the adjusting pool. More preferably, a circulating pump is arranged on the pipeline connecting the dyed brine circulation outlet and the absorption liquid inlet of the tail gas absorption tower.

[0009] According to the specific embodiment of the utility model, preferably, the adjusting pool comprises a dyed brine storage tank. More preferably, a stirring assembly is arranged in the adjusting pool. The adjusting pool is used to uniformly adjust the water quality of dyed brine, and the stirring assembly can better realize the uniformization of water quality.

[0010] According to the specific embodiment of the utility model, preferably, a water inlet pump is arranged on the pipeline connecting the dyed brine outlet of the adjusting pool and the dyed brine inlet of the decarburization pool.

[0011] According to the specific embodiment of the utility model, preferably, an acid storage tank is connected to the acid inlet of the decarburization pool, and a first dosing pump is arranged on the pipeline connecting the acid inlet of the decarburization pool and the acid storage tank. The acid inlet of the decarburization pool, the acid storage tank and the first dosing pump are used to add acid to the dyed brine in the decarburization pool to adjust the pH value of the dyed brine to 2.0-4.0. The acid can include hydrochloric acid and / or sulfuric acid and the like.

[0012] According to the specific embodiment of the utility model, preferably, the first aeration assembly of the decarburization pool at least comprises an aeration pipe, and an air source is connected to the aeration pipe, which is used to blow air into the decarburization pool from the bottom of the decarburization pool.

[0013] The utility model discloses a decarburization pool for adding acid to adjust the pH value of dyed brine to 2.0-4.0, and for blowing air into dyed brine to continuously aerate, thereby removing carbonate and stripping carbon dioxide, so as to realize the decarburization of dyed brine, and facilitate the generation of ozone, hydroxyl radical, hypochlorous acid, chlorine radical and chlorine gas in the process of electrochemical decolorization, and improve the decolorization efficiency.

[0014] According to the specific embodiment of the utility model, preferably, the electrochemical reactor at least comprises an electrolytic cell, an anode and a cathode.

[0015] The utility model discloses a dechlorination pool is arranged behind the electrochemical reactor, can take the dyeing brine after decarburization as electrolyte to realize the decoloration of the dyeing brine after decarburization.

[0016] According to the specific embodiment of the utility model, preferably, the second aeration assembly of the dechlorination pool at least comprises an aeration pipe, and the aeration pipe is connected with an air source for blowing air into the dechlorination pool from the bottom of the dechlorination pool.

[0017] The utility model discloses a dechlorination pool is arranged behind the electrochemical reactor, through the air of the dyeing brine after decoloration is blown into and is continuously aerated, can promote the chlorine gas dissolved in the dyeing brine from the water volatilization, to realize the dechlorination of the dyeing brine after decoloration.

[0018] According to the specific embodiment of the utility model, preferably, the tail gas inlet and the absorption liquid outlet of the tail gas absorption tower are arranged at the lower part of the tail gas absorption tower, the absorption liquid inlet and the purified tail gas outlet of the tail gas absorption tower are arranged at the upper part of the tail gas absorption tower, a spraying assembly is arranged in the tail gas absorption tower, the spraying assembly is communicated with the absorption liquid inlet, and the absorption liquid is contacted with the tail gas in countercurrent mode by the spraying mode to absorb the chlorine in the tail gas to obtain the purified tail gas.

[0019] The utility model further uses the dyeing brine in the adjusting pool as the absorption liquid, absorbs the chlorine in the tail gas by the spraying mode, and the chlorine in the tail gas reacts with the dye in the dyeing brine, and the spraying mode can improve the mass transfer efficiency of the two, so that most or even all of the residual chlorine in the tail gas can be removed, the safe discharge of the purified tail gas is realized, no pollution is caused, part of the dye in the dyeing brine can be removed at the same time, the load of the subsequent electrochemical decoloration can be reduced.

[0020] According to the specific embodiment of the utility model, preferably, the alkali inlet of the neutralization tank is connected with an alkali storage tank, and a second dosing pump is arranged on the pipeline connecting the alkali inlet of the neutralization tank with the alkali storage tank. The alkali inlet of the neutralization tank, the alkali storage tank and the second dosing pump are used to add alkali to the dyeing brine in the neutralization tank to adjust the pH value of the dyeing brine to neutral, for example, pH value 6.0-7.0. The alkali can include sodium hydroxide and the like. More preferably, a stirring assembly is arranged in the neutralization tank.

[0021] The utility model adjusts the pH value of the dechlorinated dyeing brine to neutral to obtain reusable dyeing brine. The dyeing brine can be reused by adding dyes and alkali to dye fabrics and the like. By adjusting the pH value of the dyeing brine to neutral through the neutralization tank, the stability of the dyes added during reuse can be protected and the interference of the acid-base neutralization process on dyeing can be avoided.

[0022] According to the specific embodiment of the utility model, preferably, the system further comprises a reuse tank connected to the treated dyeing brine outlet of the neutralization tank. The reuse tank is used to reuse the treated dyeing brine.

[0023] The utility model has at least the following beneficial effects:

[0024] The reuse system of the dyeing brine of the utility model realizes the full reuse of the dyeing brine and zero discharge of wastewater. The utility model realizes the removal of tail gas residual chlorine and most of the dyes in the dyeing brine, and the tail gas can be safely discharged. The utility model has the advantages of low operation cost, simple operation and no pollutants generated. Moreover, the reusable treated dyeing brine obtained by the utility model also has good dyeing effect. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the structure diagram of the reuse system of the dyeing brine provided in the specific embodiment of the utility model.

[0026] EXPLANATION OF REFERENCE NUMBERS:

[0027] 1 - adjustment tank;2 - decarbonization tank;201 - first aeration assembly;3 - electrochemical reactor;4 - dechlorination tank;401 - second aeration assembly;5 - tail gas absorption tower;501 - spraying assembly;6 - neutralization tank;7 - reuse tank;8 - circulating pump;9 - water inlet pump;10 - acid storage tank;11 - first dosing pump;12 - purified tail gas fan;13 - alkali storage tank;14 - second dosing pump. DETAILED DESCRIPTION

[0028] To provide a clearer understanding of the technical features, objectives, and beneficial effects of this utility model, the following detailed description is provided, but it should not be construed as limiting the scope of implementation of this utility model.

[0029] It should be noted that, unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0030] In the description of this utility model, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped with", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0032] In the description of this utility model, it should be noted that the terms "comprising," "including," and / or "containing" as used herein specify the presence of the stated features, integers, steps, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, components, or combinations thereof.

[0033] Example

[0034] In one specific embodiment of this utility model, a system for reusing dyed saline solution is provided, such as... Figure 1 As shown, it includes: equalization tank 1, decarbonization tank 2, electrochemical reactor 3, dechlorination tank 4, tail gas absorption tower 5, neutralization tank 6 and reuse tank 7;

[0035] The equalization tank 1 is equipped with at least a dye brine outlet, a dye brine circulation outlet, and a dye brine circulation inlet; the decarbonization tank 2 is equipped with at least a dye brine inlet, an acid inlet, a first aeration component 201, and a dye brine outlet; the electrochemical reactor 3 is equipped with at least a dye brine inlet and a dye brine outlet; the dechlorination tank 4 is equipped with at least a dye brine inlet, a second aeration component 401, a tail gas outlet, and a dye brine outlet; the tail gas absorption tower 5 is equipped with at least a tail gas inlet, an absorbent liquid inlet, an absorbent liquid outlet, and a purified tail gas outlet; and the neutralization tank 6 is equipped with at least a dye brine inlet, an alkali inlet, and a treated dye brine outlet.

[0036] The dyeing brine outlet of the adjusting tank 1 is connected to the dyeing brine inlet of the decarburization tank 2; the dyeing brine circulation outlet of the adjusting tank 1 is connected to the absorption liquid inlet of the tail gas absorption tower 5, and the absorption liquid outlet of the tail gas absorption tower 5 is connected to the dyeing brine circulation inlet of the adjusting tank 1, which is used for absorbing the chlorine in the tail gas by using the dyeing brine in the adjusting tank 1 as the absorption liquid to obtain the purified tail gas, and recycling the absorption liquid after absorbing the chlorine in the tail gas to the adjusting tank 1; the dyeing brine outlet of the decarburization tank 2 is connected to the dyeing brine inlet of the electrochemical reactor 3; the dyeing brine outlet of the electrochemical reactor 3 is connected to the dyeing brine inlet of the dechlorination tank 4; the tail gas outlet of the dechlorination tank 4 is connected to the tail gas inlet of the tail gas absorption tower 5; the dyeing brine outlet of the dechlorination tank 4 is connected to the dyeing brine inlet of the neutralization tank 6; the treated dyeing brine outlet of the neutralization tank 6 outputs the dyeing brine for reuse; the reuse tank 7 is connected to the treated dyeing brine outlet of the neutralization tank 6, which is used for reusing the treated dyeing brine.

[0037] A circulation pump 8 is arranged on the pipeline connecting the dyeing brine circulation outlet of the adjusting tank 1 and the absorption liquid inlet of the tail gas absorption tower 5.

[0038] The adjusting tank 1 comprises a dyeing brine storage tank. A stirring assembly is arranged in the adjusting tank 1. The adjusting tank 1 is used for uniforming the water quality of the dyeing brine, and the stirring assembly can better realize the uniformization of the water quality.

[0039] A water inlet pump 9 is arranged on the pipeline connecting the dyeing brine outlet of the adjusting tank 1 and the dyeing brine inlet of the decarburization tank 2.

[0040] An acid storage tank 10 is connected to the acid inlet of the decarburization tank 2, and a first dosing pump 11 is arranged on the pipeline connecting the acid inlet of the decarburization tank 2 and the acid storage tank 10. The acid inlet of the decarburization tank 2, the acid storage tank 10 and the first dosing pump 11 are used for adding acid to the dyeing brine in the decarburization tank 2 to adjust the pH value of the dyeing brine to 2.0-4.0. The acid can include hydrochloric acid and / or sulfuric acid, etc.

[0041] The first aeration assembly 201 of the decarburization tank 2 at least comprises an aeration pipe, and an air source is connected to the aeration pipe, which is used for blowing air into the decarburization tank 2 from the bottom of the decarburization tank 2.

[0042] The electrochemical reactor 3 at least comprises an electrolytic cell, an anode and a cathode. The electrolytic cell is a diaphragmless electrolytic cell. The anode comprises a metal oxide electrode, a glassy carbon electrode, a platinum electrode, a graphite electrode or a BDD electrode, etc., and the cathode comprises a pure metal electrode, a carbon material electrode or an alloy electrode, etc. The pure metal electrode can include a copper electrode, a lead electrode, a zinc electrode, a titanium electrode or a stainless steel electrode, etc.

[0043] The second aeration assembly 401 of the dechlorination tank 4 at least comprises an aeration pipe, and an air source is connected to the aeration pipe, which is used for blowing air into the dechlorination tank 4 from the bottom of the dechlorination tank 4.

[0044] The tail gas inlet and the absorption liquid outlet of the tail gas absorption tower 5 are arranged at the lower part of the tail gas absorption tower 5, the absorption liquid inlet and the purified tail gas outlet of the tail gas absorption tower 5 are arranged at the upper part of the tail gas absorption tower 5, the tail gas absorption tower 5 is provided with a spraying assembly 501, the spraying assembly 501 is communicated with the absorption liquid inlet, and the spraying assembly 501 is used for contacting the absorption liquid and the tail gas in a countercurrent manner by spraying to absorb the chlorine in the tail gas, so as to obtain the purified tail gas. A purified tail gas fan 12 is arranged on the pipeline connected with the purified tail gas outlet of the tail gas absorption tower 5, and the purified tail gas fan 12 is used for discharging the purified tail gas at a high altitude.

[0045] The alkali inlet of the neutralization tank 6 is connected with an alkali storage tank 13, and a second dosing pump 14 is arranged on the pipeline connected with the alkali inlet of the neutralization tank 6 and the alkali storage tank 13. The alkali inlet of the neutralization tank 6, the alkali storage tank 13 and the second dosing pump 14 are used for adding alkali to the dyeing brine in the neutralization tank 6, so as to adjust the pH value of the dyeing brine to be neutral, for example, the pH value is 6.0-7.0. The alkali can include sodium hydroxide and the like. The neutralization tank 6 is provided with a stirring assembly.

[0046] The method for recycling the dyeing brine by using the above-mentioned recycling system of dyeing brine can include the following steps: making the dyeing brine enter the conditioning tank 1 to uniformly control the water quality; then entering the decarburization tank 2 to perform decarburization, adding acid to the decarburization tank 2 to adjust the pH value of the dyeing brine to be 2.0-4.0, and continuously blowing air to perform aeration, the aeration time is 0.5-4h; then entering the electrochemical reactor 3 to perform decolorization as an electrolyte, controlling the electrolytic voltage of the electrochemical reactor 3 to be 2-100V, the current to be 1-1000A, the operating temperature to be 10-90℃, and the processing time to be 0.1-10h; then entering the dechlorination tank 4 to perform dechlorination, continuously blowing air to perform aeration, the aeration time is 2-8h, to obtain tail gas and dechlorinated dyeing brine; the tail gas enters the tail gas absorption tower 5 to absorb the chlorine therein, to obtain purified tail gas; the dechlorinated dyeing brine enters the neutralization tank 6, and alkali is added to the neutralization tank 6 to adjust the pH value of the dechlorinated dyeing brine to be neutral, to obtain treated dyeing brine.

[0047] In the method, the sodium chloride concentration of the dyeing brine in the conditioning tank 1 is 40-110g / L, the pH value is 9.0-12.0, the colority is 1000-40000 times, and the COD is 2000-8000mg / L.

[0048] The tail gas absorption tower 5 uses the dyeing brine in the conditioning tank 1 as absorption liquid, and uses a spraying manner to contact the absorption liquid and the tail gas in a countercurrent manner to absorb the chlorine therein, to obtain the purified tail gas, which can be discharged at a high altitude, and the absorption liquid after absorbing chlorine in the tail gas is recycled to the conditioning tank 1. The chlorine content in the purified tail gas is 0.5mg / m 3 The following.

[0049] The treated dyeing brine can enter the recycling pool 7 for recycling. The treated dyeing brine has a sodium chloride concentration of 50-120 g / L, a pH value of 6.0-7.0, a colority of 50-200 times, a residual chlorine content of 0.1-5 mg / L, and a COD of 2500 mg / L or less.

[0050] Test method:

[0051] The pH value of the dyeing brine is measured by a pH meter.

[0052] The sodium chloride concentration and the residual chlorine content of the dyeing brine are measured by a conductivity meter and a residual chlorine electrode, respectively.

[0053] The COD of the dyeing brine is measured by a potassium dichromate method.

[0054] The colority of the dyeing brine is measured by a dilution times method.

[0055] The total alkalinity of the dyeing brine is measured by a potentiometric titration method.

[0056] The dyeing color difference of the fabric is measured by a color difference meter.

[0057] The chlorine content of the tail gas is measured by an iodine method.

[0058] In a specific application example of the utility model, the pH value of the dyeing brine in the adjusting pool 1 is 11.1, the COD is 4500 mg / L, the sodium chloride concentration is 100 g / L, the colority is 10000 times, and the total alkalinity is 2500 mg / L. The dyeing brine is made to enter the decarburization pool 2 for decarburization, hydrochloric acid is added to the decarburization pool 2 to adjust the pH value of the dyeing brine to 2.5, and air is blown in for continuous aeration, and the aeration time is 1 h. Then, the dyeing brine enters the electrochemical reactor 3 as an electrolyte for decolorization, the electrolytic tank is a diaphragmless electrolytic tank, the anode is a ruthenium iridium electrode, the cathode is a graphite electrode, the electrolytic voltage of the electrochemical reactor 3 is controlled to be 6 V, the current is 200 A, the operating temperature is 60 DEG C, the processing time is 1 h, and the decolorized dyeing brine is obtained, the colority of which is 128 times, and the residual chlorine content is 100 mg / L. Then, the dyeing brine is made to enter the dechlorination pool 4 for dechlorination, air is blown in for continuous aeration, and the aeration time is 2 h, and the dechlorinated dyeing brine is obtained, the residual chlorine content of which is 1 mg / L. The tail gas generated in the dechlorination process enters the tail gas absorption tower 5, the dyeing brine in the adjusting pool 1 is used as the absorption liquid, the absorption liquid is contacted with the tail gas in a countercurrent manner by spraying to absorb chlorine in the tail gas to obtain purified tail gas, and the absorption liquid after absorbing chlorine in the tail gas is recycled to the adjusting pool 1. The chlorine content in the purified tail gas is 0.5 mg / m 3, realizes the safe discharge of the purified tail gas, and no pollution. Then the dechlorinated dyeing brine enters the neutralization tank 6, and sodium hydroxide is added to the neutralization tank 6 to adjust the pH value of the dyeing brine to 6.5, to obtain the treated dyeing brine. After that, the treated dyeing brine enters the reuse tank 7, the sodium chloride concentration of the treated dyeing brine is 108g / L, the pH value is 6.5, the colority is 128 times, the residual chlorine content is 1mg / L, and the COD is 2100mg / L.

[0059] The treated dyeing brine is reused, that is, used for dyeing, and the fabric for dyeing is 20 double pure cotton half-bleached cloth. A dyeing composition is added to the treated dyeing brine, the dyeing composition includes: dye Liusu black and substitute alkali, the addition amount of dye Liusu black to the fabric is 7wt%, the addition amount of substitute alkali in the treated dyeing brine is 4g / L, and no sodium chloride is supplemented. The above fabric is dyed at 60℃ for 60min with a bath ratio of 1:10.

[0060] The dyed fabric of the present embodiment and the fabric dyed with fresh sodium chloride are compared, and the color difference (△E) is 0.19, which proves that the reused dyeing brine of the present embodiment has good dyeing effect, and the dyeing effect and level dyeing are better. The process of dyeing with fresh sodium chloride includes: preparing a sodium chloride aqueous solution, the sodium chloride concentration in the solution is 108g / L, the pH value is 6.5, adding a dyeing composition to the solution, the dyeing composition includes: dye Liusu black and substitute alkali, the addition amount of dye Liusu black to the fabric is 7wt%, and the addition amount of substitute alkali in the sodium chloride aqueous solution is 4g / L; dyeing the above fabric at 60℃ for 60min with a bath ratio of 1:10.

[0061] In another specific application example of the utility model, the pH value of the dyeing brine in the adjusting pool 1 is 10.5, the COD is 3000mg / L, the sodium chloride concentration is 80g / L, the colority is 6000 times, and the total alkalinity is 1300mg / L. The dyeing brine is made to enter the decarburization pool 2 to carry out decarburization, hydrochloric acid is added to the decarburization pool 2 to adjust the pH value of the dyeing brine to 3.5, and air is blown in to carry out continuous aeration, and the aeration time is 2h. Then, it enters the electrochemical reactor 3 to carry out decolorization as electrolyte, the electrolytic tank is a diaphragmless electrolytic tank, the anode is a ruthenium iridium electrode, the cathode is a graphite electrode, the electrolytic voltage of the electrochemical reactor 3 is controlled to be 6V, the current is 100A, the operating temperature is 40 DEG C, and the processing time is 2h, and the dyeing brine after decolorization is obtained, and the colority is 64 times, and the residual chlorine content is 215mg / L. Then, it enters the dechlorination pool 4 to carry out dechlorination, air is blown in to carry out continuous aeration, and the aeration time is 2h, and the dyeing brine after dechlorination is obtained, and the residual chlorine content is 2.1mg / L. The tail gas generated in the dechlorination process enters the tail gas absorption tower 5, the dyeing brine in the adjusting pool 1 is used as the absorption liquid, the absorption liquid is contacted with the tail gas in countercurrent by the way of spraying to absorb the chlorine in the tail gas to obtain the purified tail gas, and the absorption liquid after absorbing chlorine in the tail gas is recycled to the adjusting pool 1. The chlorine content in the purified tail gas is 0.2mg / m 3 , realizing the safe discharge and pollution-free of the purified tail gas. Then, the dyeing brine after dechlorination enters the neutralization pool 6, sodium hydroxide is added to the neutralization pool 6 to adjust the pH value of the dyeing brine to 6.8, and the treated dyeing brine is obtained. Then, the treated dyeing brine enters the reuse pool 7, and the sodium chloride concentration of the treated dyeing brine is 82g / L, the pH value is 6.8, the colority is 64 times, the residual chlorine content is 2.1mg / L, and the COD is 800mg / L.

[0062] The treated dyeing brine is reused, that is, used for dyeing, and the fabric for dyeing is 20 double pure cotton half bleached cloth. A dyeing composition is added to the treated dyeing brine, the dyeing composition comprises: dye active navy blue and substitute alkali, the addition amount of the dye active navy blue relative to the fabric is 6wt%, the addition amount of the substitute alkali in the treated dyeing brine is 4g / L, and no sodium chloride is supplemented. The above-mentioned fabric is dyed at 60 DEG C for 60min with a bath ratio of 1:10.

[0063] The dyeing fabric of the present example and the fabric dyed with fresh sodium chloride are compared, and the color difference (△E) is 0.2, which proves that the reused dyeing brine of the present example has good dyeing effect, and the dyeing effect and level dyeing are both good. The process of dyeing with fresh sodium chloride includes: preparing a sodium chloride aqueous solution, wherein the concentration of sodium chloride is 82 g / L, and the pH value is 6.5; adding a dyeing composition to the sodium chloride aqueous solution, wherein the dyeing composition includes: dye active navy blue and substitute alkali, and the addition amount of dye active navy blue relative to the fabric is 6 wt%, and the addition amount of substitute alkali in the sodium chloride aqueous solution is 4 g / L; dyeing the fabric at 60°C for 60 min with a bath ratio of 1:10.

[0064] Comparative Example 1

[0065] The present comparative example provides a dyeing brine reuse system which is basically the same as the dyeing brine reuse system shown in Figure 1 , and the difference lies in that the decarburization tank 2 is not arranged, and the dyeing brine outlet of the adjusting tank 1 is connected to the dyeing brine inlet of the electrochemical reactor 3, and the rest of the structure is the same as Figure 1 .

[0066] In the present comparative example, the pH value of the dyeing brine in the adjusting tank 1 is 11.1, the COD is 4500 mg / L, the concentration of sodium chloride is 100 g / L, the colority is 10000 times, and the total alkalinity is 2500 mg / L. The dyeing brine is made to enter the electrochemical reactor 3 as an electrolyte for decolorization, the electrolytic tank is a diaphragmless electrolytic tank, the anode is a ruthenium-iridium electrode, and the cathode is a graphite electrode. The electrolytic voltage of the electrochemical reactor 3 is controlled to be 6.3 V, the current is 200 A, the operating temperature is 60°C, and the treatment time is 1 h. The decolorized dyeing brine is obtained, and the colority is 526 times, and the residual chlorine content is 432 mg / L. Then, the dyeing brine after decolorization enters the dechlorination tank 4, hydrochloric acid is added to adjust the pH value to 2.5, and dechlorination is carried out. Air is blown in for continuous aeration, and the aeration time is 2 h. The dyeing brine after dechlorination is obtained, and the residual chlorine content is 5 mg / L. The tail gas generated in the dechlorination process enters the tail gas absorption tower 5, the dyeing brine in the adjusting tank 1 is used as the absorption liquid, the absorption liquid and the tail gas are countercurrently contacted in a spraying manner to absorb chlorine in the tail gas to obtain purified tail gas, and the absorption liquid after absorbing chlorine in the tail gas is recycled to the adjusting tank 1. The chlorine content in the purified tail gas is 0.3 mg / m 3 . Then, the dyeing brine after dechlorination enters the neutralization tank 6, sodium hydroxide is added to the neutralization tank 6 to adjust the pH value of the dyeing brine to 6.5, and the treated dyeing brine is obtained. Then, the treated dyeing brine enters the reuse tank 7, the concentration of sodium chloride in the treated dyeing brine is 108 g / L, the pH value is 6.5, the colority is 512 times, the residual chlorine content is 5 mg / L, and the COD is 2800 mg / L.

[0067] The treated dyeing brine was reused for dyeing, and the dyed fabric was 20S pure cotton half bleached cloth. A dyeing composition was added to the treated dyeing brine, the dyeing composition comprising: dye Liusen black and substitute alkali, the addition amount of dye Liusen black was 7wt% with respect to the fabric, the addition amount of substitute alkali in the treated dyeing brine was 4g / L, and no sodium chloride was added. The fabric was dyed at 60°C for 60min with a bath ratio of 1:10.

[0068] The dyed fabric of the present comparative example and the fabric dyed with fresh sodium chloride were compared, and the color difference (△E) was 1.0. The process of dyeing with fresh sodium chloride was the same as the first application example.

[0069] Comparative Example 2

[0070] The present comparative example provided a dyeing brine reuse system which was basically the same as the dyeing brine reuse system shown in Figure 1 , except that the dechlorination tank 4 and the tail gas absorption tower 5 were not provided, the dyeing brine circulation outlet and the dyeing brine circulation inlet were not provided in the adjusting tank 1, the dyeing brine outlet of the electrochemical reactor 3 was connected to the dyeing brine inlet of the neutralization tank 6, and the rest of the structure was the same as Figure 1 .

[0071] In the present comparative example, the pH value of the dyeing brine in the adjusting tank 1 was 11.1, the COD was 4500mg / L, the sodium chloride concentration was 100g / L, the colority was 10000 times, and the total alkalinity was 2500mg / L. The dyeing brine was fed into the decarburization tank 2 for decarburization, hydrochloric acid was added to the decarburization tank 2 to adjust the pH value of the dyeing brine to 2.5, and air was blown in for continuous aeration, and the aeration time was 1h. Then it entered the electrochemical reactor 3 as electrolyte for decolorization, the electrolytic tank was a diaphragmless electrolytic tank, the anode was a ruthenium-iridium electrode, and the cathode was a graphite electrode. The electrolytic voltage of the electrochemical reactor 3 was controlled to be 6V, the current was 200A, the operating temperature was 60°C, the treatment time was 1h, and the decolorized dyeing brine was obtained, the colority of which was 128 times, and the residual chlorine content was 100mg / L. Then it entered the neutralization tank 6, sodium hydroxide was added to the neutralization tank 6 to adjust the pH value of the dyeing brine to 6.5, and the treated dyeing brine was obtained. Then the treated dyeing brine entered the reuse tank 7, the sodium chloride concentration of the treated dyeing brine was 108g / L, the pH value was 6.5, the colority was 128 times, the residual chlorine content was 93mg / L, and the COD was 2100mg / L.

[0072] The treated dyeing brine is reused for dyeing, and the fabric for dyeing is 20 double pure cotton half-bleached cloth. A dyeing composition is added to the treated dyeing brine, the dyeing composition comprising: dye Liusu black and substitute alkali, the addition amount of dye Liusu black being 7 wt% with respect to the fabric, the addition amount of substitute alkali in the treated dyeing brine being 4 g / L, and no sodium chloride is added. The fabric is dyed at 60 DEG C for 60 min with a bath ratio of 1:10.

[0073] The dyed fabric of the present comparison example and the fabric dyed with fresh sodium chloride are compared, and the color difference (△E) is 2.1. The process of dyeing with fresh sodium chloride is the same as the first application example.

[0074] It can be seen that, compared with the comparison examples, the reuse system of the dyeing brine provided by the embodiment of the present application realizes full reuse of the dyeing brine and zero discharge of waste water; and realizes removal of the tail gas residual chlorine and most of the dyes in the dyeing brine, and the tail gas can be safely discharged; has the advantages of low operation cost, simple operation, no pollutants generated, etc.; and the reusable treated dyeing brine also has good dyeing effect.

Claims

1. A system for reusing dyeing saline solution, characterized in that, include: Equalization tank, decarbonization tank, electrochemical reactor, dechlorination tank, tail gas absorption tower, and neutralization tank; The equalization tank is provided with at least a dyed brine outlet; the decarbonization tank is provided with at least a dyed brine inlet, an acid inlet, a first aeration component, and a dyed brine outlet; the electrochemical reactor is provided with at least a dyed brine inlet and a dyed brine outlet; the dechlorination tank is provided with at least a dyed brine inlet, a second aeration component, a tail gas outlet, and a dyed brine outlet; the tail gas absorption tower is provided with at least a tail gas inlet, an absorbent liquid inlet, an absorbent liquid outlet, and a purified tail gas outlet; and the neutralization tank is provided with at least a dyed brine inlet, an alkali inlet, and a treated dyed brine outlet. The dyed brine outlet of the equalization tank is connected to the dyed brine inlet of the decarbonization tank; the dyed brine outlet of the decarbonization tank is connected to the dyed brine inlet of the electrochemical reactor; the dyed brine outlet of the electrochemical reactor is connected to the dyed brine inlet of the dechlorination tank; the tail gas outlet of the dechlorination tank is connected to the tail gas inlet of the tail gas absorption tower; the dyed brine outlet of the dechlorination tank is connected to the dyed brine inlet of the neutralization tank; the treated dyed brine outlet of the neutralization tank outputs dyed brine for reuse.

2. The dyeing saline reuse system according to claim 1, characterized in that, The equalization tank is also equipped with a dyeing brine circulation outlet and a dyeing brine circulation inlet. The dyeing brine circulation outlet is connected to the absorbent inlet of the tail gas absorption tower, and the absorbent outlet of the tail gas absorption tower is connected to the dyeing brine circulation inlet. The dyeing brine in the equalization tank is used as the absorbent to absorb chlorine in the tail gas to obtain purified tail gas, and the absorbent after absorbing chlorine in the tail gas is circulated back to the equalization tank.

3. The dyeing saline reuse system according to claim 1, characterized in that, The acid inlet of the decarbonization tank is connected to an acid storage tank, and a first dosing pump is installed on the pipeline connecting the acid inlet of the decarbonization tank and the acid storage tank.

4. The dyeing saline reuse system according to claim 1, characterized in that, The first aeration component of the decarbonization tank includes at least an aeration pipe connected to an air source for blowing air into the decarbonization tank from the bottom.

5. The dyeing brine reuse system according to claim 1, characterized in that, The electrochemical reactor includes at least an electrolytic cell, an anode, and a cathode.

6. The dyeing brine reuse system according to claim 5, characterized in that, The electrolytic cell is a diaphragmless electrolytic cell.

7. The dyeing brine reuse system according to claim 5, characterized in that, The anode includes a metal oxide electrode, a glassy carbon electrode, a platinum electrode, a graphite electrode, or a BDD electrode, and the cathode includes a pure metal electrode, a carbon material electrode, or an alloy electrode.

8. The dyeing brine reuse system according to claim 1, characterized in that, The second aeration component of the dechlorination tank includes at least an aeration pipe connected to an air source for blowing air into the dechlorination tank from the bottom.

9. The dyeing brine reuse system according to claim 1, characterized in that, The exhaust gas inlet and absorbent outlet of the exhaust gas absorption tower are located at the lower part of the exhaust gas absorption tower, and the absorbent inlet and purified exhaust gas outlet of the exhaust gas absorption tower are located at the upper part of the exhaust gas absorption tower. The exhaust gas absorption tower is equipped with a spray assembly, which is connected to the absorbent inlet and is used to spray the absorbent and exhaust gas in a countercurrent manner to absorb the chlorine in the gas and obtain purified exhaust gas.

10. The dyeing brine reuse system according to claim 1, characterized in that, The neutralization tank has an alkali inlet connected to an alkali storage tank, and a second dosing pump is installed on the pipeline connecting the alkali inlet of the neutralization tank to the alkali storage tank.

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