Treatment of textile waste water containing Brilliant Red and a mixture of Brilliant Red & Orange II by electrocoagulation

The decolorization of Brilliant Red and a mixture of Brilliant Red & Orange II by the D.C. Electrocoagulation (EC) method has been studied in a flow cell using sodium chloride as an internal electrolyte. The cell contained five parallel iron electrodes placed vertically parallel to each other. Two of the electrodes were monopolar placed at the two ends and the others acted as bipolar. Experiments were carried out at room temperature under various electrolyte concentrations, dye concentrations, current density, flow rate of the solution, number of cycles, and initial pH to determine the optimum conditions.The optimized conditions are: Current density 155 A/m2; dye concentration 10 ppm; electrolyte concentration 4.0 g/1; flow rate 500 ml/l .The initial pH does not have much effect on removal efficiency (RE%) and the optimum RE% were 86% for mixed dye and 83% for Brilliant Red. The residue from a blank run and dye added run were collected by vacuum filtration and analyzed by XRD, FTIR, and SEM after drying. The XRD data indicated the presence of mainly maghemite (alpha-Fe2O3) and magnetite (Fe3O4) in the residue. In FUR studies, some of the absorbance peaks from both Brilliant Red and Orange II were observed and SEM of the solid residues also indicated the same. It may be concluded that the removal occurred because of simple physical adsorption on the surface.