Azo printing and dyeing wastewater treatment process

Abstract

The invention relates to an azo printing and dyeing wastewater treatment process, which is characterized in that biological adsorption treatment, wall breaking treatment, anaerobic acidification, reduction treatment and membrane filtration treatment are sequentially carried out, printing and dyeing wastewater containing azo dyes is subjected to biological adsorption treatment, due to the huge specific surface area of microorganisms, 70% or above of azo dyes are adsorbed on the surface of zoogloea, ultrasonic wall-breaking treatment is performed on the sludge adsorbed with the dye pollutants, the toxic and harmful dye is sufficiently mixed with slurry obtained after microbial crushing and conveyed to an anaerobic acidification process for treatment, when the pH value is reduced to 4.5-6.3, supernate in an anaerobic acidification pool is conveyed to a reduction treatment process for reduction treatment, zero-valent iron is used for reducing azo dyes under acidic anaerobic conditions, azo bonds are broken, and the chromaticity is reduced.

Description

technical field [0001] The invention belongs to the field of printing and dyeing wastewater treatment, and in particular relates to an azo printing and dyeing wastewater treatment process. Background technique [0002] With the rapid development of the textile industry, the discharge of printing and dyeing wastewater is huge. The printing and dyeing wastewater has the characteristics of high concentration of organic matter, high chroma, high content of inorganic salts, complex components, and poor biodegradability. Due to the low treatment rate, the discharge of printing and dyeing wastewater to the water environment cause serious pollution. Dyes have a complex structure, and many of them are variants. They come from a wide range of sources. Most of the dyes are made from carcinogens. If they are discharged into water bodies without treatment, studies have shown that some dyes will continue to pass through the food chain. accumulation. Although its concentration may be low...

AI Technical Summary

Problems solved by technology

As a strong oxidant, persulfate is added to the printing and dyeing wastewater, because it has no specific oxidation characteristics, and the organic matter in the wastewater will react with it. The treatment cost is high and the efficiency is low, so it is difficult to be used in printing and dyeing wastewater on a large scale. ;

[0004] CN101624250B discloses a sewage treatment method of anaerobic zero-valent iron, which releases Fe in the anaerobic reactor through internal electrolysis, neutralization of organic acids, etc. 2+ , because zero-valent iron contains carbon and other inert materials, it is the cathode during the reaction process, and iron is the anode, forming an electrode reaction. However, in the process of treating printing and dyeing wastewater in this process, due to the poisonous effect of azo fuels, it will greatly reduce the reaction. Efficiency, even difficult to degrade degradable substances in printing and dyeing wastewater

[0005] There is a major problem in the above processes of printing and dyeing wastewater using zero-valent iron as a reducing agent, that is, in the actual wastewater treatment process, it is difficult to directly treat refractory organic matter with oxidants or microorganisms, and the toxic substances in printing and dyeing wastewater will reduce microbial activity and thus As a result, the biochemical method is difficult to continue to operate, and in the oxidation process, due to the variety of organic substances in the printing and dyeing wastewater, it is difficult to treat toxic substances

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