High Concentrations Of Dye Wastewater (including Azo Dye Wastewater) Processing Technology

Dye is a kind of typical fine chemical products, wastewater of which is characterized with high concentration and complication of organic components, more difficultly reduced substances, high colority, poison etc. Azo dye constitutes the more than 80 percent dyes. Azo dye, which is the most complete spectrum, most widely applied and lower price dye, is widely applied in textile industry, printing and dyeing, leather industry etc. At present, the treatment of azo dye wastewater is still a big difficult problem in our country. So the study on the treatment process has important and practical significance.In this paper, by means of a large number of references and wastewater examples of azo dye manufacturer the author has systematically studied the whole treatment process technique of wastewater from azo dye production, in view of the cost of treatment, put forward optimum process technique and basic experiment conditions. The author concludes that respectively treating wastewater according to their concentration can acquire better results. Because of Azo dye's special structure and character, we treat the wastewater by bipolar packed bed cell electrolytic reaction container. At the condition of 10V electrolysis voltage, 0.018A/cm2 electrical current density, 2 hours electrolysis, the removal rates of COD and colority of high concentration wastewater are 85% and 95% respectively. Ozone(C>3) can react with aromatic azo compound, destroy azo bond. As the second oxidization treatment after electrolysis, ozonization furthermore reduce COD and colority of high concentration wastewater. The pretreated high concentration wastewater was compounded with low concentration wastewater in proportion, and treated by coagulation process. The effluent quality can reach requirements of wastewater discharge standards. Analyzing the practical beneficial result of certain azo dye manufacturer treatment of wastewater, we conclude the cost of wastewater treatment is 0.8 Yuan/m3. This treatment process technique has better value of application and dissemination.