Removal of methylene blue by electrocoagulation: a study of the effect of operational parameters and mechanism

Electrocoagulation has become an attractive approach to remove organic dye pollutants from wastewater in recent years. The current study investigated the removal of methylene blue by the electrocoagulation method using aluminum electrodes. The effects of the operating parameters, such as electrolysis time, initial solution pH value, initial dye concentration, and electrolyte dosage were investigated to optimize the operating conditions for maximum benefits. The findings in this study revealed that an increase in the electrolysis time up to 5–30 min enhanced the color removal efficiency, from a dye solution in the pH range of 3 to 11. The experimental results showed that the electrocoagulation method is significantly efficient in the removal of methylene blue. The maximum dye removal efficiency achieved was 99.37% under the following operating conditions: current density of 5 mA/cm2, electrolysis time of 30 min, initial solution pH value of 7, and sodium chloride concentration of 0.2 mol/L. The methylene blue removal mechanism was studied by Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy.