Circulation dyeing method for dye wastewater

Abstract

The invention relates to a circulation dyeing method for dye wastewater, belonging to the technical field of treatment of fabrics and the like. The method comprises the following steps: regulating the pH value of the dye wastewater to be 7-7.5, adding 0.1-5g / L of cationic decoloring agent, stirring for 1-5 minutes, and precipitating and decolorizing; taking the supernatant, regulating the salinity, and supplementing new dyes for dyeing. The method disclosed by the invention is applied to dyeing with reactive dyes and has the advantages that the flow is short, the method is simple, discharge amount of the wastewater is greatly reduced, the utilization rate of water and inorganic salts is improved, and the like.

Description

technical field

[0001] The invention relates to a method for circular dyeing of dye wastewater, which belongs to the technical field of fabric treatment. Background technique

[0002] Cellulose fiber is the largest textile fiber in the world, and reactive dyes have become the most important dyes for cellulose fiber textile dyeing due to their simple molecular structure, bright color, complete color spectrum, convenient use, and low cost. At present, the annual output of reactive dyes for cellulose fibers in the world has reached about 250,000 tons, accounting for about 20% of the world's total annual output of dyes, and the development speed of new reactive dyes is also among the best among all kinds of dyes, so dyeing with reactive dyes The amount of waste water produced is relatively large.

[0003] Reactive dyes contain water-soluble groups, which can be ionized in water to form dye anions, and cellulose fibers are negatively charged in the dye bath, so there is an elect...

Examples

Embodiment 1

[0029] In this embodiment, red reactive dyes are used to dye wastewater, and the ultraviolet-visible spectral curve of the wastewater in the wavelength range of 200-800nm ​​is as follows: image 3 As shown, adopt the hydrochloric acid of 5% mass concentration to carry out pH titration to this clear liquid, after adjusting pH to be 7~7.5, add the cationic decolorizing agent of 0.123g / L (Guangzhou Zhongbei Environmental Protection Technology Co., Ltd., model Z8- SD), after stirring for 2 minutes, carry out precipitation decolorization, centrifuge for 5 minutes after decolorization is complete, and take the supernatant. Measure the ultraviolet-visible spectral curve of the clear liquid in the wavelength range of 200-800nm, such as Figure 4 As shown, the color influencing factors in the supernatant have basically been removed, and the supernatant is clear and thorough.

[0030] Add the anionic surfactant (the low-molecular-weight copolymer of maleic acid and acrylic acid) of 2g / ...

Embodiment 2

[0037] In this embodiment, yellow reactive dye dyed wastewater is used as the treatment object, and the ultraviolet-visible spectral curve in the wavelength range of 200-800nm ​​of the wastewater is as follows: Figure 5 As shown, adopt the sulfuric acid of 5% mass concentration to carry out pH titration to this clear liquid, adjust the pH to be 7~7.5 after adding the cationic decolorant of 0.142g / L (Guangzhou Zhongbei Environmental Protection Technology Co., Ltd., model Z8-SD ), after stirring for 2 minutes, precipitate and decolorize, centrifuge for 5 minutes after the decolorization is complete, and take the supernatant. Measure the ultraviolet-visible spectral curve of the clear liquid in the wavelength range of 200-800nm, such as Image 6 As shown, the color influencing factors in the supernatant have basically been removed, and the supernatant is clear and thorough.

[0038] Add 1.5g / L of anionic surfactant (alkyl naphthalene sulfonate) and stir for 5min to make the ani...

Embodiment 3

[0044] In this embodiment, blue reactive dyes are used to dye wastewater, and the ultraviolet-visible spectral curve in the 200-800nm ​​wavelength range of the wastewater is as follows: Figure 7 As shown, adopt the sulfuric acid of 5% mass concentration to carry out pH titration to this clear liquid, adjust the pH to be 7~7.5 after adding the cationic decolorant of 0.215g / L in the waste water (Guangzhou Zhongbei Environmental Protection Technology Co., Ltd., model Z8-SD ), after stirring for 2 minutes, precipitate and decolorize, centrifuge for 5 minutes after the decolorization is complete, and take the supernatant. Measure the ultraviolet-visible spectral curve of the clear liquid in the wavelength range of 200-800nm, such as Figure 8 shown.

[0045] Add 1.2g / L of anionic surfactant and stir for 5min to make the anionic surfactant (low molecular copolymer of maleic acid and acrylic acid or anionic surfactant of alkyl naphthalene sulfonate) fully react with cationic decolo...

technical field

[0001] The invention relates to a method for circular dyeing of dye wastewater, which belongs to the technical field of fabric treatment. Background technique

[0002] Cellulose fiber is the largest textile fiber in the world, and reactive dyes have become the most important dyes for cellulose fiber textile dyeing due to their simple molecular structure, bright color, complete color spectrum, convenient use, and low cost. At present, the annual output of reactive dyes for cellulose fibers in the world has reached about 250,000 tons, accounting for about 20% of the world's total annual output of dyes, and the development speed of new reactive dyes is also among the best among all kinds of dyes, so dyeing with reactive dyes The amount of waste water produced is relatively large.

[0003] Reactive dyes contain water-soluble groups, which can be ionized in water to form dye anions, and cellulose fibers are negatively charged in the dye bath, so there is an elect...

Examples

Embodiment 1

[0029] In this embodiment, red reactive dyes are used to dye wastewater, and the ultraviolet-visible spectral curve of the wastewater in the wavelength range of 200-800nm ​​is as follows: image 3 As shown, adopt the hydrochloric acid of 5% mass concentration to carry out pH titration to this clear liquid, after adjusting pH to be 7~7.5, add the cationic decolorizing agent of 0.123g / L (Guangzhou Zhongbei Environmental Protection Technology Co., Ltd., model Z8- SD), after stirring for 2 minutes, carry out precipitation decolorization, centrifuge for 5 minutes after decolorization is complete, and take the supernatant. Measure the ultraviolet-visible spectral curve of the clear liquid in the wavelength range of 200-800nm, such as Figure 4 As shown, the color influencing factors in the supernatant have basically been removed, and the supernatant is clear and thorough.

[0030] Add the anionic surfactant (the low-molecular-weight copolymer of maleic acid and acrylic acid) of 2g / ...

Embodiment 2

[0037] In this embodiment, yellow reactive dye dyed wastewater is used as the treatment object, and the ultraviolet-visible spectral curve in the wavelength range of 200-800nm ​​of the wastewater is as follows: Figure 5 As shown, adopt the sulfuric acid of 5% mass concentration to carry out pH titration to this clear liquid, adjust the pH to be 7~7.5 after adding the cationic decolorant of 0.142g / L (Guangzhou Zhongbei Environmental Protection Technology Co., Ltd., model Z8-SD ), after stirring for 2 minutes, precipitate and decolorize, centrifuge for 5 minutes after the decolorization is complete, and take the supernatant. Measure the ultraviolet-visible spectral curve of the clear liquid in the wavelength range of 200-800nm, such as Image 6 As shown, the color influencing factors in the supernatant have basically been removed, and the supernatant is clear and thorough.

[0038] Add 1.5g / L of anionic surfactant (alkyl naphthalene sulfonate) and stir for 5min to make the ani...

Embodiment 3

[0044] In this embodiment, blue reactive dyes are used to dye wastewater, and the ultraviolet-visible spectral curve in the 200-800nm ​​wavelength range of the wastewater is as follows: Figure 7 As shown, adopt the sulfuric acid of 5% mass concentration to carry out pH titration to this clear liquid, adjust the pH to be 7~7.5 after adding the cationic decolorant of 0.215g / L in the waste water (Guangzhou Zhongbei Environmental Protection Technology Co., Ltd., model Z8-SD ), after stirring for 2 minutes, precipitate and decolorize, centrifuge for 5 minutes after the decolorization is complete, and take the supernatant. Measure the ultraviolet-visible spectral curve of the clear liquid in the wavelength range of 200-800nm, such as Figure 8 shown.

[0045] Add 1.2g / L of anionic surfactant and stir for 5min to make the anionic surfactant (low molecular copolymer of maleic acid and acrylic acid or anionic surfactant of alkyl naphthalene sulfonate) fully react with cationic decolo...

Images