Effects of Stainless Steel and Iron Electrode on Removal of Dyes in Electrocoagulation Process

Abstract

Electrocoagulation (EC) is one of the most effective techniques to remove color and organic pollutants from wastewater, which reduces the sludge generation. In this paper, electrocoagulation has been used for the removal of color from solutions containing Direct Black 22. The effect of operational parameters such as current density, initial pH of the solution, time of electrolysis, initial dye concentration and solution conductivity were studied in an attempt to reach higher removal efficiency. The findings in this study shows that an increase in the current density up to 0.5 to 1.0 enhanced the color removal efficiency, the electrolysis time was 5, 10 and 15 min and the range of pH was determined between 2.0 to 11.0 for dye solutions. It was found that for, the initial concentration of dye in solutions should not be higher than 100mg/l in order to achieve a high color removal percentage. The optimum conductivity was found to be 4 ms/cm, which was adjusted using proper amount of Nacl with the dye concentration of 50 mg/l. Also, during the EC process under the optimized conditions, the COD decreased by more than 70% and 80% in iron and stainless steel electrode. Color removal efficiency for stainless steel electrode is 99.6% and iron 93.39% respectively.