Process for comprehensively treating sulfur dye waste water

Abstract

The invention relates to a process for comprehensively treating sulfur dye waste water. The process of the invention uses a split-flow scheme which comprises that dye bath strong liquor with high concentration can be recycled and the comprehensive waste water with low concentration can be collected. The process of the invention comprises the following steps: acidifying the dye bath strong liquor with high concentration, blowing and recovering sodium sulfide, filtering and recovering the sulfur dye, wherein the recovery rate of the sodium sulfide and the sulfur dye can respectively reach more than 85% and 95%, collecting a filtrate into a waste water treatment system for treating; pretreating the comprehensive waste water with low concentration by an electrocoagulation process and discharging or carrying out biochemical treatment. Compared with the current art, the process of the invention has the advantages of high resource recovery rate, simple flow, less equipment, less land occupation, simple operation and maintenance and the like, and is suitable for recycling and treating the sulfur dye waste water.

Description

technical field [0001] The invention relates to the field of wastewater treatment, and more specifically relates to a comprehensive treatment process for sulfur dye printing and dyeing wastewater and its specific implementation technical scheme. Background technique [0002] Sulfur dyes are water-insoluble dyes that can be used for dyeing cotton, linen, viscose and other fibers. The manufacturing process is simple, the cost is low, the fastness is high, and the utility model is widely used. Sulfur dyes are insoluble in water. When dyeing, sodium sulfide or other reducing agents are used to reduce the dyes to soluble leucosomes that have affinity for fibers, and then use oxidants to oxidize and develop color and restore the insoluble state, so that they can be fixed on the fibers. Finish staining. Sulfur dyes will produce a large amount of wastewater during the dyeing process. The wastewater contains a large amount of salts, sulfides, and dyes. It has the characteristics of...

AI Technical Summary

Problems solved by technology

This method has a good treatment effect, but there are several problems as follows: First, due to the high content of sulfide in the wastewater, a large amount of ferrous sulfate needs to be added, which not only has high operating costs, but also produces a large amount of sludge, resulting in The cost of mud treatment and disposal is extremely high; second, because the sulfur dyes and sulfides contained in the wastewater are mixed and precipitated together, the sediment can only be treated as waste, which is not only expensive, but also a great waste of resources; third, due to The amount of ferrous sulfate added is very large, resulting in a high content of sulfate in the wastewater, which is very harmful to the subsequent anaerobic biological treatment

This method can realize the recovery and utilization of useful components in sulfur dye wastewater, but the recovery process is complex and the equipment is numerous, resulting in extremely high investment and operating costs, difficult operation and management, and little practical value.

[0005] To sum up, although sulfur dye wastewater treatment, clean production and recycling methods can realize the discharge of wastewater up to the standard and the recycling of some components, and reduce the load of subsequent process treatment, these methods are usually complicated in process and require multiple unit process equipment, investment High, high operating costs, cumbersome operation; and many process conditions are relatively harsh, and there may be side reactions that affect product yield

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