Abstract

The increasing presence of dyes represents a major environmental toxicity hazard; therefore, finding and development of new methods for dye removal from waste water has generated significant interest. Chemical, physical and electrochemical methods have limited use as they have many disadvantages compared with the biological methods. The aim of this study was to test the effects of immobilization and some culture conditions on decolorization of methylene blue and malachite green by <em>Desmodesmus</em> sp. isolated from local environment. Decolorization of dyes by free and immobilized <em>Desmodesmus</em> sp. was tested by monitoring the decrease in absorbance of each dye under different culture condition such as incubation time and dye concentrations. The results showed that the maximum decolorization of both dyes with immobilized algae after 6 days at 20 mg.L-1 of dye concentration with 98.6%. The results showed that there was decolorization ability of immobilized <em>Desmodesmus</em> sp. against the dyes compared with free one. The analysis of the results showed that there was different factors affected decolorization ability.