Title: Biological decolourisation of simulated azo dye in aqueous phase by algae Spirogyra species

Authors: S.V. Mohan, Y.V. Bhaskar, J. Karthikeyan

Addresses: Biochemical and Environmental Engineering Center, Indian Institute of Chemical Technology, Hyderabad 500 007, India. ' Biochemical and Environmental Engineering Center, Indian Institute of Chemical Technology, Hyderabad 500 007, India. ' Department of Civil Engineering, Sri Venkateswara University, Tirupati 517 502, India

Abstract: Biological decolourisation of two azo dye effluents (direct and reactive dye) were investigated using a commonly available green algae Spirogyra sp. in viable form. Batch studies revealed the potential of algal species in removing the dye colour and dye removal was dependant on initial algal inoculum, concentration and application class of the dye. Maximum dye uptake was noticed on the third day for both the dyes. Higher dye uptake was observed in the case of direct red 28 compared to reactive red 2. Dye colour removal by the algal species may be attributed to biosorption of the dye molecules onto the surface of algal cell and subsequent diffusion and participation in metabolism (bioconversion). The remaining dye molecules could be further removed from the aqueous phase by adsorption and/or chelation reaction of the exopolymers released by the algae (biocoagulation). The results of the present study reveal the potential nature of algae in treating azo dyes which in turn can be extended to oxidation pond system of wastewater treatment.

Keywords: reactive dye; direct dye; azo dye; Spirogyra species; biosorption; biocoagulation.

DOI: 10.1504/IJEP.2004.004190

International Journal of Environment and Pollution, 2004 Vol.21 No.3, pp.211 - 222

Available online: 02 Apr 2004 *

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