Dye waste water treatment method based on membrane technology

Abstract

The present invention discloses a method for treatment of dye waste water based on membrane technique, mainly comprising the part of fore treatment of dye waste water and the part of membrane filtration-seperation system. Fore treatment of dye waste water consists of techniques such as exhaust conditioning, flocculating setting and clarifying. Membrane filtration-seperation system consists of techniques such as hyperfiltration circulation and Na-filtration circulation. The invention is a new treatment of dye waste water based on membrane technique, characterized in that the CODCr and PH of the dye waste water is adjusted in the equalizing tank before it enters the membrane filtration-seperation system. Afterwards, the waste water is uniformly mixed in the flocculation retort and then deposits in the flocculation precipitating tank. The clarified solution is disposed by the treatment of hyperfiltration, the hyperfiltration dislysate is disposed by the treatment of Na-filtration, the Na-filtration dislysate is absorbed by the activated carbon, and as a result the water let meets the sewage discharge standard of two-level GB8978-96. The method is especially suitable for treatment of waste water of azo-dyes which is difficult to meet the discharge standard by the conventional waste treatment.

Description

technical field [0001] The invention relates to a method for treating wastewater, in particular to a method for treating dye wastewater, and belongs to the field of wastewater treatment for environmental protection. Background technique [0002] With the development of dyestuff and printing and dyeing industry, its production wastewater has become one of the most important sources of water pollution. As an important source of environmental pollution, dyes are characterized by a large amount of pollution. At present, the annual output of dyes in the world is about 800,000 to 900,000 tons, and the annual output of dyes in my country is 150,000 tons, ranking among the top in the world. %-15% of the dyes are discharged into the environment with the wastewater. my country's dye industry and textile printing and dyeing industry are developed, and the pollution of dye wastewater to the environment is more serious. According to the data in the Environmental Bulletin in 1998, the cur...

AI Technical Summary

Problems solved by technology

The second is that as environmental pollutants, there are many kinds of dyes and complex structures

The third is that most dyes are toxic and refractory organic substances with strong chemical stability and have the "three causes" of carcinogenic, teratogenic and mutagenic

Although electrolysis and oxidation are effective in removing the chroma of dye wastewater, COD often Cr The removal is not ideal, the cost of treatment chemicals is relatively high, and many new oxidation methods are still in the stage of experimental research and have not been industrialized

[0014] In terms of biochemistry, azo dyes are typical fine chemical products. They have the characteristics of small batches and many varieties. Such unit operations should have many by-products, low product yields, and complex organic components in wastewater. The chemical reaction process of dye production and the processes of separation, refining, and washing are all using water as a solvent, and the water consumption is large.

Although the biochemical treatment of dye wastewater has the advantage of less investment, there are still problems such as the difficulty for microorganisms to adapt to dye wastewater, the characteristics of large water quality fluctuations, and high toxicity, and the sludge disposal, biogas treatment and management in the anaerobic section are complicated.

It is often difficult to achieve the expected effect by using a single treatment method for the treatment of azo dye wastewater

The conventional method is to combine various treatment methods, which has defects such as long process flow, high operating cost, and unstable effluent quality.

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