%0 Journal Article
%T Degradation of a textile reactive azo dye by a combined biological-photocatalytic process: Candida tropicalis Jks2 -Tio2/Uv
%A Jafari Narjes
%A Kasra-Kermanshahi Rouha
%A Soudi Mohammad Reza
%A Mahvi Amir Hossein
%J Iranian Journal of Environmental Health Science & Engineering
%D 2012
%I Tehran University of Medical Sciences
%R 10.1186/1735-2746-9-33
%X In the present study, the decolorization and degradation of Reactive Black 5 (RB5) azo dye was investigated by biological, photocatalytic (UV/TiO2) and combined processes. Application of Candida tropicalis JKS2 in treatment of the synthetic medium containing RB5 indicated complete decolorization of the dye with 200 mg/L in less than 24 h. Degradation of the aromatic rings, resulting from the destruction of the dye, did not occur during the biological treatment. Mineralization of 50 mg/L RB5 solution was obtained after 80 min by photocatalytic process (in presence of 0.2 g/L TiO2). COD (chemical oxygen demand) was not detectable after complete decolorization of 50 mg/L RB5 solution. However, photocatalytic process was not effective in the removal of the dye at high concentrations (¡Ý200 mg/L). With 200 mg/L concentration, 74.9% of decolorization was achieved after 4 h illumination under photocatalytic process and the absorbance peak in UV region (attributed to aromatic rings) was not completely removed. A two-step treatment process, namely, biological treatment by yeast followed by photocatalytic degradation, was also assessed. In the combined process (with 200 mg/L RB5), absorbance peak in UV region significantly disappeared after 2 h illumination and about 60% COD removal was achieved in the biological step. It is suggested that the combined process is more effective than the biological and photocatalytic treatments in the remediation of aromatic rings.
%K Azo dyes
%K Candida tropicalis
%K Combined wastewater treatment
%U http://www.ijehse.com/content/9/1/33