Treatment method of dye wastewater

Abstract

The invention discloses a method for processing dye wastewater, comprising the following steps of: injecting dye wastewater which undergoes a pretreatment into a nanofiltration water inflow tank for nanofiltration to form a nanofiltration concentrated solution with a smaller volume and a nanofiltration dialysate with a larger volume; diluting the nanofiltration concentrated solution to decrease the salt content and then carrying out an anaerobic-aerobic treatment; and carrying out an activated carbon adsorption treatment on the nanofiltration dialysate. In allusion to the features of high salt content and high COD concentration in the dye wastewater, the pretreatment is performed at the front end to reduce part of COD loads, and the nanofiltration technology is adopted at the back end to separate the salt in sewage from organic matters; the concentrated solution with high concentration of organic matters is diluted to reduce COD, simultaneously decrease the salt content and carry out the anaerobic-aerobic biochemical process so as to complete the processing of the sewage. As it is tested that the COD of the dialysate is low, the dialysate undergoes the activated carbon adsorption to directly discharge salts; absorbed organic matters undergo activated carbon desorption and regeneration process as well as biodegradation. The part of wastewater has been desalinized, thus not influencing the biochemical process.

Description

technical field [0001] The invention relates to wastewater treatment, in particular to a treatment method for dye wastewater. Background technique [0002] Due to the characteristics of dye wastewater with high COD, high chroma, high salt content, difficult biodegradation of organic matter, and large changes in water quality and quantity over time (indirect discharge of wastewater), dye wastewater has become a difficult point in the field of industrial wastewater treatment. Since the 1970s, developed countries have begun to invest a lot of money in environmental governance. On the one hand, they have improved the production process, implemented source control, and minimized the discharge of wastewater in production. On the other hand, they have explored various methods to treat dye wastewater. Purify. The treatment of dye wastewater includes various methods. According to different treatment principles, the treatment methods can be mainly divided into physical methods, chemi...

AI Technical Summary

Problems solved by technology

[0017] However, although dye wastewater can be treated by the above method or a combination of several methods, the current treatment of dye wastewater is still not ideal

The main reasons are as follows: due to the high salt content of the wastewater produced by the salting out method, the salt content is as high as 8%-10%, and the high salt content cannot complete the anaerobic-aerobic biochemical process, although the method of dilution can be used to reduce the salt content. content, but a large amount of dye wastewater needs to be diluted several times with water to meet the salt content requirements that biochemical treatment can withstand, so the dilution method is not feasible

On the other hand, if the activated carbon adsorption method is used, although this method has no requirement for the salt content, the high concentration in the wastewater makes the activated carbon reach saturation quickly, and the cost is high, so the activated carbon adsorption method cannot be applied in the main treatment process

Images