Decolorization of Tartrazine azo dye by Sulphidogenesis Process and the effect of pH

Abstract

This study aims to investigate Tartrazine as a model azo dye with a concentration of 100 mg/l for decolorisation by sulphidogenesis process in a sequencing batch reactor (SBR). SBR was operated at 30±2 ℃ room temperature and initial cycle time of 7 days which has later been reduced to 1-2 days. SBR was operated at COD/Sulphate ratio of 1. SBR did well in terms of reducing color, COD and sulphates. Maximum color, COD and sulphate removal were 84%, 74% and 88% respectively. Activated sludge could be used as seed biomass for the development of the process. In the later part of our study, we tried to optimize the best pH to remove color by setting the six reactors with varying pH. The results show that optimal pH for decolorization is between 8 and 9 and effective color removal (87-92%) could be achieved in a day. It is also seen that alkaline pH is more favoured than acidic pH for decolorization of Tartrazine. The results of this study indicate an economical and ecofriendly technique for decolorization of Tartrazine at 100 mg/l.