Abstract
A new cell design which makes an efficient use of the cathodically evolved H2 to improve the mixing efficiency and the
floatation ability during electrocoagulation was used to remove dyes from waste solution. In this study, the decolorization and
COD reduction of colored solutions containing reactive and basic dyes by electrocoagulation was investigated using aluminum
electrodes in a batch mode. The effect of operating parameters such as current density, initial dye concentration, NaCl
concentration and pH on the percentage color removal and on percentage COD reduction have been examined. The results
indicate that electrocoagulation is very efficient technique which is able to achieve ˃ 95% color removal and ˃ 50% in COD
reduction under suitable operating conditions for the two dyes. The energy consumption was calculated and found to range from
4.26 to 19.04 and from 4.36 to 21 kWh/kg dye removed depending on the operating conditions for reactive and basic dyes
respectively. Energy consumption based on COD reduction was found to be ranges from 10.33 to 36.1 and from 6.53 to 30.6
kWh/kg COD removed for the two dyes respectively.