The Research Of Azo Dyes Degraded By The Potassium Ferrate

With the rapid development of dyestuff industry, the number and the variety of dyestuff has increased day by day. The environment pollution taken by dye wastewater has stepped up in the meanwhile. Azo dyes constitute the largest and the most important class of commercial dyes. Because of its high chromaticity, strong toxicity and difficulty to degrade, traditional techniques such as adsorption, coagulation, biological oxidation can be generally used inefficiently to remove dyes from azo-dye wastewater. Potassium ferrate which is a multi-function water treatment agent with the novel properties of oxidation, coagulation, disinfection and deodorization, is arousing more and more widespread interest of researchers. This article researched the degradation of azo dyes by potassium ferrate, which extends the application of potassium ferrate in wastewater treatment and is meaningful to the treatment of print and dyeing wastewater.In this article, potassium ferrate was used to degrade methyl orange, chrome black T and acid chrome blue K which had azo-dye structure. We use the decoloration of azo-dye, removal ration of TOC and the structure change reflected by UV spectrum to evaluate the disposal effect of azo-dyes by potassium ferrate. We systemically studied the technical condition of this method which effected the disposal of azo-dyes. The result indicated that the supply of ferrate, pH of the initial solution and the time of reaction exerted great effect on the decoloration.We also researched the intermediates of methyl orange degraded by potassium ferrate and speculated the possible degradation pathway using the instruments of HPLC and GC-MS.In the end, we also used potassium ferrate to degrade actual dye wastewater. Potassium ferrate possessed excellent degradation effect. The BOD₅/COD of the wastewater was raised from 0.16 to 0.32 improving the bio-degradability of wastewater.