Removal of direct blue dye by electrocoagulation method has been investigated using aluminum

electrode in a bench-scale electrochemical system. Current density, NaCl concentration,

electrocoagulation time, and dye concentration has been studied as effecting parameters in color

removal efficiency. Increasing of current density will increase the color removal efficiency and

energy consumption as well. While increasing NaCl concentration increase the color removal

efficiency but it decrease energy consumption. High dye concentration is needed for extra

electrocaogolation time to reach the same efficiency that obtained with low dye concentration .With

current applied 0.35 amps. and NaCl concentration of 2 g/l more than 93% efficiency achieved in

14 min. of electrocaogolation time.