Treating and recycling process of acid wastewater generated in disperse dye production

A technology for disperse dyes and acidic wastewater, which is applied in water/sewage multi-stage treatment, water/sludge/sewage treatment, chemical instruments and methods, etc. It can solve the problem of increasing treatment costs, increasing treatment steps, and the risk factor of liquid ammonia storage and transportation. Advanced problems, to achieve the effect of saving dosage, enhancing flocculation effect, and avoiding adverse effects

Active Publication Date: 2014-06-25
ZHEJIANG DIBANG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] For example, the patent document CN102826673A discloses a cleaning treatment method for dye industrial acid wastewater. After the wastewater is purified by neutralization, decolorization, oxidation, concentration, separation and other measures, it can be reused as synthetic bottom water for dye production and dye filter cake washing water. Abandoning the discharge of a large amount of colored and high COD value wastewater in the traditional dye production process, this patent document uses liquid ammonia to replace the current lime or calcium carbide slag for waste acid neutralization in wastewater treatment, solving the landfill of hazardous solid waste and sulfuric acid Calcium slag is difficult to deal with, but the risk factor of large-scale storage and transportation of liquid ammonia is extremely high. At the same time, the solubility of ammonium sulfate does not change much with temperature, and the temperature difference between cooling and crystallization needs to be relatively large, and it is accompanied by high-concentration ammonia nitrogen wastewater.
[0005] Patent document CN101412571A discloses a waste water recycling process in the production of azo dyes. A large amount of mother liquor waste water and washing waste water generated in the dye production process are treated and reused for washing filter cakes, which reduces waste water discharge to a certain extent. , but did not really achieve zero discharge of wastewater
[0006] Another patent document CN103214116A realizes the recycling of sulfuric acid-containing wastewater, but in the process, the calcium sulfate produced by neutralizing the waste acid needs to be calcined and other post-treatments, which increases the number of treatment steps and increases the treatment cost to a certain extent.

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  • Treating and recycling process of acid wastewater generated in disperse dye production
  • Treating and recycling process of acid wastewater generated in disperse dye production

Examples

Experimental program
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Embodiment 1

[0039] Such as figure 1 Shown:

[0040] (1) Preparation of Disperse Blue 291:3 filter cake

[0041] Add 3800kg of nitrosyl sulfuric acid and 800kg of 98% sulfuric acid into the reactor, and add 2,4-dinitro-6-chloroaniline and 2,4-dinitro-6-bromoaniline with a mass ratio of 3:1 2000kg , stir to dissolve, control the temperature at 25-30°C for reaction, and detect the end point of the reaction with starch potassium iodide test paper to obtain a diazonium salt solution. Add 2600kg (dried) 2-methoxy-5-acetylamino-N,N-diallylaniline and 5kg Pingpingjia O-15 to 32 tons of sulfuric acid aqueous solution with an acid value of 8%, beat for 2 hours use. Slowly add the above-prepared diazonium salt solution into the prepared coupling solution, add 20 tons of ice, and carry out the coupling reaction at -5 ~ 0°C. After the reaction is completed, press filter, and the filtrate is 46 tons of mother liquor water. The filter cake is washed with water until the neutral disperse blue 291:3 f...

Embodiment 2

[0053] Preparation of Disperse Orange 30 filter cake

[0054] According to the method described in embodiment 1, the difference is:

[0055] In step (1), 2400kg of nitrosyl sulfuric acid is added to the reaction kettle, and then 2,6-dichloro-4-nitroaniline is added to react with 2000kg, and 2500kg of N-cyanoethyl-N-acetoxyethylaniline is added to the 25 tons of sulfuric acid aqueous solution with an acid value of 10%. With 15 tons of ice during coupling, filter cake is washed to neutrality with 130 tons of clear water; Obtain 32 tons of mother liquor water, 89 tons of acid washing water, 15 tons of neutral washing water;

[0056] In step (2), use Disperse Orange 30 instead of Disperse Blue 291:3;

[0057] In step (3), use 15 tons of neutral washing water instead of 15 tons of clear water to make ice for the coupling reaction, 15 tons of mother liquor water and 10 tons of acidic washing water instead of sulfuric acid aqueous solution as the bottom water for the coupling react...

Embodiment 3

[0059] (1) Preparation of Disperse Violet 93:1 filter cake

[0060] According to the method described in embodiment 1, the difference is:

[0061] In step (1), add 2100kg of nitrosyl sulfuric acid and 900kg of 98% sulfuric acid into the reactor, then add 2000kg of 2,4-dinitro-6-chloroaniline to react, and 2150kg of N,N-diethylm-acetyl Aminoaniline is added to 29 tons of sulfuric acid aqueous solution with an acid value of 5.5%. During coupling, use 18 tons of ice and 145 tons of clear water to wash the filter cake of Disperse Violet 93:1 to neutral; obtain 42 tons of mother liquor water, 125 tons of acidic washing water, and 18 tons of neutral washing water;

[0062] In step (2), use disperse violet 93:1 instead of disperse blue 291:3;

[0063] In step (3), use 18 tons of neutral washing water instead of 18 tons of clear water to make ice, 19 tons of mother liquor water and 10 tons of acidic washing water instead of sulfuric acid aqueous solution as bottom water for coupling...

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Abstract

The invention discloses a treating and recycling process of acid wastewater generated in disperse dye production. The process comprises the steps of collecting acid wastewater generated by a same disperse dye, and separately collecting mother liquor water and washing water; adding at least one of magnesium oxide, magnesium hydroxide and magnesium carbonate to the collected mother liquor water and washing water, and adjusting the pH value to be 7-8; adding solid soda to the wastewater after adjustment until the pH value of the wastewater is 9-12, thereby obtaining first filtrate and first filter residues; adding a mixture of aluminium trichloride and solid soda to the first filtrate, thereby obtaining second filtrate and second filter residues; recycling part of the second filtrate in washing of dye filter cakes, carrying out condensation crystallization on the remaining filtrate, and recycling the condensed water. According to the process, recycling of the wastewater and magnesium is achieved by neutralizing acid water generated in the dye and intermediate production process by utilizing magnesium oxide, magnesium hydroxide or magnesium carbonate and then precipitating magnesium ions with solid soda, therefore, the process meets the requirement for clean production of resources.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a process for treating and recycling acidic wastewater in the production process of disperse dyes. Background technique [0002] Azo disperse dyes are generally produced through diazotization and coupling reactions between aniline derivatives. Therefore, dye wastewater usually contains toxic and harmful substances such as aniline derivatives, as well as inorganic or organic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and acetic acid. and inorganic salts such as sodium chloride or sodium sulfate. A large amount of acidic wastewater generated in the dye production process not only has high salinity and high COD value, but also has a chromaticity of several tens of times. At the same time, due to its low biodegradability, direct treatment and discharge will cause serious harm to the environment. At present, most enterprises first use calcium carbid...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04
Inventor 徐万福刘伟陈华祥周海斌
Owner ZHEJIANG DIBANG CHEM
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