ELECTROCOAGULATION FOR THE TREATMENT OF DYE BEARING WASTEWATER

Abstract

The textile industry discharges a lot of waste water that causes a lot of environmental problems in terms of high color, dissolved organics and lot of inorganic salts. In the present study, Electrocoagulation (EC) has been proved to be an effective mechanism for the removal of color and chemical oxygen demand (COD) from real textile waste water consisting of reactive dye used for dyeing cotton fibre. Several operating parameters: contact time (t), initial pH, current density (J) and electrode spacing (x) were studied for their effect on removal efficiency. It has been seen that pH of the solution greatly influences the removal in terms of COD and does not have significant effect on color removal efficiency. Higher current density and less distance between electrodes favor the process. The removal efficiency in terms of color and COD were found to be 90% and 56% respectively. The optimum pH of the solution was found to be 8, current density (60 mA/cm2), contact time(150 min) and spacing 1 cm. The scum and sludge produced during the process was analyzed. SEM, TGA and XRD were done to determine the major compounds in scum and sludge and to see their burning characteristics. In this way EC is a good technique for the removal of these color and COD.