Enhanced biological decolourization of azo dyes by the catalysis of reduced acid azo dyes

The enhanced biodecolorization of azo dyes by quinone-reducing community with reduced acid azo dyes as redox mediator was investigated. Products reduced from acid red B could enhance the biodecolorization of several kinds of azo dyes as redox mediators. When the concentration of reduced acid red B was 0.2mol/L, the optimal pH for biodecolorization conditions of active red KE-3B were determined from 7 to11 and the decolorization rate increased with the increase of the temperature in the range of 4~40℃. In conclusion, it was presumed that 2-amino-1-naphthol-4-sulphonate enhanced the biodecolorization of azo dyes as redox mediators from HPLC-MS results of the products reduced from acid red B.