Decolorization of Malachite Green and Methylene Blue by Two Microalgal Species

Dye wastewater is one of the most difficult to treat. Meanwhile, there has been exhaustive research on biosorption of dye wastewater and it is evolving as an attractive option to supplement conventional treatment processes. This paper examines the capacity of Chlorella vulgaris Beijerinck and Dunaliella salina Teodoresco (Chlorophyceae) to decolorize two model dyes, malachite green and methylene blue, from their aqueous solutions. The effect of dye concentration, algal concentration (number of cells/ml culture) and pH on the rate of decolorization was studied. The dye concentration at different times of the decolorization process was measured. The rate of dye decolorization was found to increase with the increase of both algal concentration and, to certain extent, the increase of dye concentration. The decolorization of dye is also affected by the pH of the media. In conclusion, these algae showed high efficiency for color removal of the examined dyes.