Treatment of debrominated wastewater by electrocoagulation using Mild Steel electrodes

Abstract

Most process industries produce a large amount of effluent which includes bromine, which is valuable for further use. After the separation of valuable bromine from such industrial wastewater, a sizeable amount of debrominated wastewater (DWW) with a large amount of contaminates is left over. Considering the chemical oxygen demand (COD), total dissolved solid (TDS), turbidity, and color parameters, DWW cannot be discharged directly to water bodies. It mandatorily requires to be treated for the removal of various contaminants. Wastewater treatment includes traditional processes like chemical treatment, biological treatment, and physical treatment. Although they have been effective, each process has its limitations and can be energy-intensive and costly. Electrocoagulation (EC) is a highly effective treatment process that has been widely used to treat complex industrial wastewater. To treat DWW, The EC treatment was conducted in a 2-liter batch reactor using Mild Steel electrodes (MS) arranged as four parallel plates. After the treatment achieved maximum color, turbidity, COD, and TDS removal of 71.91%,100%, 36.36%, and 24.95%, respectively, at optimal current intensity 2 A, pH 9, and electrode spacing 1.5 cm. Energy consumption of 3 Wh/L was observed as a maximum at pH 11 and a maximum total metal consumption (TMC) of 2.11 g/L at pH 7. The highest foam and residue weight was 6.81 kg/m3 at pH 9 and the highest sedimentation rate was found at pH 11. Electrocoagulation treatment time was also examined for each parameter such as pH, electrode gap, and current intensity.