The Use of Redox Mediators for Enhancing the Decolourisation of Orange G in a Sequencing Batch Reactor (SBR)

The declorization of the acid azo dye, Orange G (Acid Orange 10) in an anaerobic phase of the anaerobic-aerobic sequencing batch reactor feed by synthetic wastewater was investigated. Moreover, the impact of a redox mediator (AQS) on the color removal was studied. it is for the first time that the decolorization of Orange G is investigated in SBR system with activated sludge. The redox mediator was really effective for cleavage the azo band and increased the efficiency of the reactor. When 20 mg/l of Orange G was added to the sysnthetic wastewater, the decolorization efficiency was 50 % without the addition of AQS. The decolorization efficiency increased up to 75% when the small quantity of AQS, 0.05nM, was added to the wastewater. The high COD removal of synthetic dye wastewater was observed during the operation. The COD removal was always in the range of 80-90 %.