Biological decolorization of dye solution containing malachite green by macroalgae Cladophora sp.

In recent years, the ability of macroalgae on decolorizing of textile wastewater has received great attention due to the environmental persistence and toxicity of these pollutants. In this paper biological decolorization of triphenylmethane dye, Malachite Green, by Cladophora species was investigated. The algal species was acquired from natural lake and used immediately. According to its morphology and microscopic observations, it is identified as Cladophora species belonging to green algae. The effect of operational parameters such as temperature, pH, initial dye concentration and algal weight on decolorization efficiency was examined. Results indicated that uptaken dye amount increased with increasing initial dye concentration in the range of 2.5-15 ppm. Decolorization efficiency was also increased with an increase the amount of alga, reached the optimal value of algae amount (4g fresh weight) and then became constant. The stability and efficiency of the algae in long-term repetitive operations were also examined. Accordingly, it could be stated that the complete removal of color, after selecting optimal operational parameters could be achieved in a relatively short time, about 7 h.