Decolorization of reactive blue-2 dye in aqueous solution by electrocoagulation process using aluminum and steel electrodes

Abstract

In this study we have applied electrocoagulation process for the decolorization of synthetic wastewater containing Reactive Blue-2 (RB-2). Electrocoagulation is eco-friendly, cost-effective and low maintenance technique which is best wastewater technology to remove total suspended solids (TSS), soluble organic compounds and other contaminants from water. Experiments for decolorization of RB-2 solutions were performed by varying the types of electrode Aluminum (Al) and steel connected with DC power supply. Color removal of RB-2 solution was determined by double beam UV spectrophotometer. Significance of the data was determined by applying Two-way ANOVA. Synthetic wastewater samples were prepared in laboratory using RB-2 dye by dissolving its known concentrations in distilled water. In this study we had studied the effect of four experimental variables initial pH, electrolysis time and current density and dye concentration on efficiency of color removal of RB-2 dye. Optimum experimental conditions for RB-2 dye was found at 95% color removal efficiency i.e. electrolysis time = 6 min, initial pH = 3 and at current density = 16.6 mA/cm2 and dye concentration = 5 ppm using steel electrodes. Among both the electrodes, steel showed best results at all experimental variables. Chlorine quenching experiments reveals that active chlorine species had also significantly affects the color removal. It was confirmed from the ANOVA that the decolorization of RB-2 solutions were significantly affected by varying the types of electrodes and other experimental parameters. From overall results it can be concluded that this system can be apply for decolorization of real wastewater.