Electroagulation for Treating Industrial Wastewater Containing Copper

Abstract

Electrocoagulation (EC) is an electrochemical method of treating polluted water whereby sacrificial anodes corrode to release active coagulant precursors (usually aluminium or iron cations) into solution. Accompanying electrolytic reactions evolve gas (usually as hydrogen bubbles) at the cathode. Electrocoagulation involves dissolution of metal from the anode with simultaneous formation of hydroxyl ions and hydrogen gas occurring at the cathode. Electrocoagulation has been proposed since before the turn of the century with Vik et al. (1984) describing a treatment plant in London built in 1889 (for the treatment of sewage by mixing with seawater and electrolyzing). In 1909, in the United States, J.T. Harries (Vik et al., 1984) received a patent for wastewater treatment by electrolysis with sacrificial aluminium and iron anodes. A variety of designs have been employed with no dominant design till now. Often the electrocoagulation units are used simply as a replacement for chemical dosing systems and do not take advantage of the electrolytic gases produced in the electrocoagulation process. It is clear that electrocoagulation has the capability to remove a large range of pollutants under a variety of conditions ranging from: suspended solids This study was conducted to investigate the effectiveness of electrocoagulation using aluminum and iron electrodes for the removal of heavy metals from synthetic wastewater and copper from the industrial wastwater. The purposes of this study were to investigate the effects of the operating parameters on pH, flow rate, reaction time, current density, and inter-electrode distances on a synthetic wastewater containing heavy metals. The optimum operating conditions were determined and then applied to treat an industrial wastewater containing copper. Copper was successfully removed from that industrial wastewater by using electrocoagulation. During the EC process for synthetic wastewater under different conditions, the separation of heavy metal ions such copper (Cu), nickel (Ni) and lead (Pb) was studied. It has been observed that electrocoagulation is feasible technology for the removal of heavy metals from wastewater. It has been showed that at optimum conditions such as HRT 60 seconds, current intensity 0.026 A/cm2, gap between electrodes 10 mm and pH from 6.11, the removal efficiency reached to more than 80% for both Al and Fe electrode. Electrocoagulation process for the treatment of industrial wastewater containing copper was also found very effective method of treatment. It has been observed that after applying the same optimum condition (pH 6.11, HRT 60 seconds, gap 10mm, and current density 0.026A/cm2), the removal efficiency of the electrocoagulation reactor reached above 80% for both Al and Fe electrodes.