A method for treating active dye wastewater

Abstract

The application discloses a kind of active dye wastewater treatment methods, it is characterized in that, including the following steps: step 1, in active dye wastewater, polyamino compound or polyhydroxy compound is added, and active dye molecule is condensed to form active dye molecule condensate reaction;Step 2, by coagulation precipitation method or adding color removal coagulant and flocculating agent, with the active dye molecule condensate described above to form precipitate, remove colority.The active dye wastewater treated by the method of the present application compared with prior art, using conventional sewage treatment method, the decolorization effect is greatly improved.

Description

Technical Field

[0001] The invention relates to a method for treating reactive dye wastewater, and belongs to the technical field of organic synthesis. Background Art

[0002] Reactive dyes contain one or more reactive groups within their molecules. Under appropriate conditions, these reactive groups can react chemically with hydroxyl groups on cellulose fibers, and amino groups on protein fibers and polyamide fibers, forming covalent bonds. Because reactive dye molecules contain a high number of water-soluble groups, such as sulfonic acid groups, they are highly water-soluble.

[0003] Reactive dyes are mainly used for dyeing and printing of cotton, linen, viscose, nylon, silk and wool textiles. China is a traditional textile power.

[0004] Due to their high water solubility, reactive dyes are difficult to decolorize using conventional coagulation and sedimentation processes and treatment with color removal coagulants and flocculants. Typically, the color removal rate can only reach 30-50%. Therefore, there is an urgent need to solve the technical problem of how to better treat dye wastewater. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problem of how to better treat dye wastewater.

[0006] In order to achieve the purpose of solving the above problems, the technical solution adopted by the present invention is to provide a method for treating dye wastewater, comprising the following steps:

[0007] Step 1: adding a polyamino compound or a polyhydroxy compound to the reactive dye wastewater to carry out a condensation reaction with the reactive dye molecules to form a reactive dye molecule condensate, wherein the polyamino compound includes a methylenediamine-type aliphatic diamine compound or an aromatic diamine intermediate;

[0008] Step 2: remove the color by coagulation and precipitation method or by adding color removal coagulant and flocculant to form a precipitate with the above-mentioned reactive dye molecule condensate.

[0009] Further preferably, the methylenediamine-based aliphatic diamine compound is selected from one or more of ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine and hexamethylenediamine; and the aromatic diamine intermediate is selected from one or more of p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, naphthalenediamine and DSD acid.

[0010] More preferably, the polyamino compound is selected from one or more of ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine and p-phenylenediamine.

[0011] Preferably, the pH value of the reaction in step 1 is 8.0-13.0; more preferably 8.5-12.0; and even more preferably 9.0-11.5.

[0012] Preferably, the reaction temperature in step 1 is 25-70°C; more preferably 30-60°C; and even more preferably 35-55°C.

[0013] Preferably, the reaction time of step 1 is 2-10 hours, more preferably 3-8 hours, and more preferably 3-6 hours.

[0014] Preferably, the coagulation precipitation method in step 2 is a ferrous sulfate coagulation precipitation method.

[0015] Preferably, the color removal coagulant in step 2 is PAC, and the flocculant is nonionic polyacrylamide or cationic polyacrylamide, more preferably cationic polyacrylamide, and more preferably quaternary ammonium salt polyacrylamide.

[0016] Preferably, the pH range of the coagulation precipitation treatment in step 2 is 10-10.5.

[0017] Preferably, the pH range of the color removal coagulant and flocculant treatment in step 2 is 7.0-9.0.

[0018] Preferably, the standing time after the coagulation sedimentation treatment in step 2 is 5-30 min; more preferably 5-10 min.

[0019] Preferably, the standing time after the treatment with the color removal coagulant and flocculant in step 2 is 2-20 min; more preferably, it is 10-20 min.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. After the reactive dye wastewater is treated by the method of the present invention, the decolorization effect is greatly improved by using conventional sewage treatment methods. DETAILED DESCRIPTION

[0022] In order to make the present invention more clearly understood, preferred embodiments are described in detail as follows:

[0023] Treatment of reactive orange dye wastewater: the original chromaticity of the dye wastewater is 200,000. Take 100g of dye wastewater, add 0.09g of ethylenediamine, react at a pH of 10.5-11.0 and a temperature of 45°C for 5 hours, then mix the dye wastewater with process wastewater at a ratio of 1:20 to form wastewater with an original chromaticity of 10,000 times, add 0.1% PAC and 5ppm cationic PAM, adjust the pH to 8.0 with liquid alkali or hydrochloric acid, stir evenly, let it stand for 10 minutes, and absorb the supernatant to test the chromaticity. The test value is 500 times, and the chromaticity removal rate reaches 95%.

[0024] Example 2

[0025] Treatment of reactive red dye wastewater: the original chromaticity of the dye wastewater is 250,000. Take 100g of dye wastewater, add 0.16g of p-phenylenediamine, react at pH 9.0-9.5, temperature 35-40℃ for 3 hours, then mix the dye wastewater with process wastewater at a ratio of 1:20 to form wastewater with an original chromaticity of 12,500 times, add 0.13% PAC and 6ppm cationic PAM, adjust the pH to 8.0 with liquid alkali or hydrochloric acid, stir evenly, let it stand for 15 minutes, and absorb the supernatant to test the chromaticity. The test value is 800-1000 times, and the chromaticity removal rate reaches 92%.

[0026] Example 3

[0027] Treatment of reactive blue dye wastewater: the original chromaticity of the dye wastewater is 230,000. Take 100g of dye wastewater, add 0.08g of ethylenediamine, react at a pH of 10-10.5 and a temperature of 40°C for 3.5 hours, then mix the dye wastewater with process wastewater at a ratio of 1:20 to form wastewater with an original chromaticity of 11,500 times, add 0.11% PAC and 5ppm cationic PAM, adjust the pH to 8.5 with liquid alkali or hydrochloric acid, stir evenly, let it stand for 15 minutes, and absorb the supernatant to test the chromaticity. The test value is 1200-1500 times, and the chromaticity removal rate reaches 87-89%.

[0028] Example 4

[0029] Reactive black dye wastewater treatment, the original chromaticity of the dye wastewater is 300,000. Take 100g of dye wastewater, add 0.1g of ethylenediamine, react at pH 11.0-11.5, temperature 35℃ for 4.5 hours, then mix the dye wastewater with process wastewater at a ratio of 1:20 to form wastewater with an original chromaticity of 15,000 times, add 0.15% PAC and 6ppm cationic PAM, adjust the pH to 8.5 with liquid alkali or hydrochloric acid, stir evenly, let it stand for 15 minutes, and absorb the supernatant to test the chromaticity. The test value is 600-800 times, and the chromaticity removal rate reaches 94%.

[0030] Comparative Example 1

[0031] The reactive orange dye wastewater in Example 1 was directly mixed with process wastewater at a ratio of 1:20 to form wastewater with an original chroma of 10,000 times. 0.1% PAC and 5 ppm cationic PAM were added, and the pH was adjusted to 8.0 with liquid alkali or hydrochloric acid. After stirring evenly, the mixture was allowed to stand for 10 minutes. The supernatant was aspirated to test the chroma, and the test value was 5000 times, indicating a chroma removal rate of only 50%.

[0032] Comparative Example 2

[0033] The reactive red dye wastewater in Example 2 was directly mixed with the process wastewater at a ratio of 1:20 to form wastewater with an original chromaticity of 12,500 times. 0.13% PAC and 6 ppm cationic PAM were added, and the pH was adjusted to 8.0 with liquid alkali or hydrochloric acid. After stirring evenly, the mixture was allowed to stand for 15 minutes, and the supernatant was aspirated to test the chromaticity. The test value was 5,000 times, and the chromaticity removal rate was 60%.

[0034] Comparative Example 3

[0035] The reactive blue dye wastewater in Example 3 was directly mixed with the process light wastewater at a ratio of 1:20 to form wastewater with an original chroma of 11,500 times. 0.15% PAC and 6 ppm cationic PAM were added, and the pH was adjusted to 8.5 with liquid alkali or hydrochloric acid. After stirring evenly, the mixture was allowed to stand for 15 minutes, and the supernatant was aspirated to test the chroma. The test value was 4,500 times, and the chroma removal rate was 60%.

[0036] Comparative Example 4

[0037] The reactive black dye wastewater in Example 4 was directly mixed with the process light wastewater at a ratio of 1:20 to form wastewater with an original chroma of 15,000 times. 0.15% PAC and 6 ppm cationic PAM were added, and the pH was adjusted to 8.5 with liquid alkali or hydrochloric acid. After stirring evenly, the mixture was allowed to stand for 15 minutes, and the supernatant was aspirated to test the chroma. The test value was 5500 times, and the chroma removal rate was 63%.

Claims

1. A method for treating reactive dye wastewater, characterized in that: The following steps are involved: Step 1: Adding a polyamino compound or a polyhydroxy compound to reactive dye wastewater to carry out a condensation reaction with reactive dye molecules to form a reactive dye molecule condensate, wherein the pH value of the reaction is 8.0-13.0 and the temperature is 25-70°C; the polyamino compound includes a methylenediamine-type aliphatic diamine compound or an aromatic diamine intermediate; the polyamino compound includes one or more of ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine and p-phenylenediamine; Step 2: removing the color by coagulation and precipitation or adding a color removal coagulant and flocculant to form a precipitate with the above-mentioned reactive dye molecule condensate; the color removal coagulant is PAC, and the color removal flocculant is nonionic polyacrylamide or cationic polyacrylamide.

2. The method for treating reactive dye wastewater as claimed in claim 1, wherein The methylenediamine-based aliphatic diamine compound includes one or more of ethylenediamine, propylenediamine, butylenediamine, pentanediamine and hexamethylenediamine; the aromatic diamine intermediate includes one or more of p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, naphthalenediamine and DSD acid.

3. The method for treating reactive dye wastewater as claimed in claim 1, wherein In the step 1, the reaction time is 2-10 hours.

4. The method for treating reactive dye wastewater as claimed in claim 3, wherein: The step 1 satisfies one or more of the following conditions: Condition 1 is that the pH value of the reaction is 8.5-12.0; Condition 2 is a reaction temperature of 30-60°C; Condition 3 is a reaction time of 3-8 hours.

5. The method for treating reactive dye wastewater as claimed in claim 4, wherein: The step 1 satisfies one or more of the following conditions: Condition 1 is that the pH value of the reaction is 9.0-11.5; Condition 2 is a reaction temperature of 35-55°C; Condition 3 is a reaction time of 3-6 hours.

6. The method for treating reactive dye wastewater as claimed in claim 1, wherein Step 2 satisfies one or more of the following conditions: Condition 1 is that the coagulation precipitation method is ferrous sulfate coagulation precipitation method; Condition 2 is that the pH range of the coagulation precipitation method is 10-10.5; Condition 3 is that the pH range of the color removal coagulant and flocculant treatment is 7.0-9.0; Condition 4 is that the standing time after the coagulation sedimentation treatment is 5-30 minutes; Condition 5 is that the standing time after the treatment with the color removal coagulant and flocculant is 2-20 minutes.

7. The method for treating reactive dye wastewater according to claim 6, wherein: Step 2 satisfies one or more of the following conditions: Condition 1 is that the color removal coagulant is PAC and the color removal flocculant is cationic polyacrylamide; Condition 2 is that the standing time after the coagulation sedimentation treatment is 5-10 minutes; Condition 3 is that the standing time after the treatment with the color removal coagulant and flocculant is 10-20 minutes.

8. The method for treating reactive dye wastewater as claimed in claim 7, wherein: The cationic polyacrylamide is a quaternary ammonium salt polyacrylamide.