Electrocoagulation process applied on pollutants treatment- experimental optimization and fundamental investigation of the crystal violet dye removal

Abstract

The removal crystal violet (CV) from wastewater solutions was performed by electrocoagulation process based on an aluminum sacrificial anode. The effect of the operating parameters was experimentally investigated; a complete removal was achieved after 1 h electrolyses, and various ‘short times’ electrolyses were carried out to fundamentally investigate the main physical phenomena conditioning the flocs formation and allowing to achieve satisfactory coagulation rates. A simplified theoretical model was proposed to predict the dye removal rate and to design an electrochemical reactor. It is based on a mechanism, involving Al(OH)3 oligomers formation, and competition between electrochemical oxidation and coagulation rate. The good agreement between simulation and experiments, allows i) the required kinetic constant value to be determined and ii) the limiting step to be defined as a reaction involving one Al(OH)3 fixating 4 molecules of the crystal violet. The presented results may be easily extrapolated to other dyes removal.