Method for treating azo printing and dyeing wastewater by using biological filters

Abstract

The invention provides a method for treating azo printing and dyeing wastewater by using biological filters. The method comprises the following steps: S1, mixing oyster shells as a filler with seed sludge, and adding the obtained mixture into an anaerobic biological filter and an aerobic biological filter; S2, arranging azo printing and dyeing wastewater, and adjusting the concentration of azo dyes in the azo printing and dyeing wastewater; S3, sequentially adding the azo printing and dyeing wastewater into the anaerobic biofilter and the aerobic biofilter, and respectively standing the wastewater for 5-14 d; and S4, adjusting the influent flow rate, and continuously sequentially introducing the azo printing and dyeing wastewater into the anaerobic biofilter and the aerobic biofilter. The oyster shells act as a carrier of a biofilm, so the azo dyes can be acidified in the anaerobic degradation process to reduce the pH value, and the calcium carbonate can be dissolved out to increase the alkalinity, thereby maintenance of the pH value of the azo printing wastewater at 6-7 is beneficial to adapt to the characteristic of large change in the pH value of the printing and dyeing wastewater, and achieves a good decolorizing effect; and the anaerobic biological filter adopting oyster shells as the filler has a degrading effect on various azo dyes.

Description

technical field [0001] The invention relates to the field of printing and dyeing wastewater treatment, in particular to a method for treating azo printing and dyeing wastewater by utilizing a biological filter. Background technique [0002] Printing and dyeing wastewater has the characteristics of deep color, high alkalinity, and large changes in water quality. It is a difficult industrial wastewater to treat. The direct discharge of printing and dyeing wastewater is extremely harmful to health and the ecological environment. How to remove chroma smoothly and effectively is the main problem to be solved in the printing and dyeing wastewater treatment process. [0003] Azo dyes account for more than 60-70% of synthetic dyes used in the world, and are the most widely used dyes. Azo dyes are complex organic compounds formed by linking aromatic rings with azo groups. Under anaerobic conditions, the azo dyes obtain electrons from the azo bond and reductively crack to generate ...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems of complicated, difficult and costly treatment of azo printing and dyeing wastewater, the present invention proposes a method for treating azo printing and dyeing wastewater by using a biological filter. The biological filter includes an anaerobic biological filter and an aerobic biological filter. The aerobic biofilter is provided with an air distribution pipe and an air outlet. Both the anaerobic biofilter and the aerobic biofilter include a pool body, oyster shell filler, support plate, water inlet and water outlet. The oyster shell filler is placed on the support On the plate, the supporting plate is set at the lower part of the pool body, the water inlet is set under the supporting plate, the water outlet is set at the top of the pool body, and the water outlet of the anaerobic biological filter is connected with the water inlet of the aerobic biological filter , the method includes the following steps:

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