The methyl orange (MO) simulated dye wastewater was treated by electrocoagulation. The effect of operation parameters on MO decolorization and the kinetic model of chemical oxygen demand (CODCr) removal were investigated. Operation parameters

such as input voltage

electrode distance

initial MO concentration

electrolyte concentration and pH

were investigated based on the decolorization efficiency of MO. Experimental results showed that up to 97% of color decay was obtained after 10 min reaction with input voltage of 20 V

current of 0.4 A

electrode distance of 2.5 cm

treated volume of 500 ml

initial MO concentration of 500 mg·L-1

electrolyte KCl concentration of 0.5 g·L-1 and pH of 3.0. A kinetic model for CODCr reduction was established based on the coagulation and oxidation processes. The experimental data fitted well with the model curves. The parameters predicted from the kinetic model showed that the coagulation process was the main pathway for CODCr removal and the oxidation process was the next. In addition

the increase of Fe2+ in the solution decreased the CODCr removal.