Electrochemical Remediation of Phthalocyanine Dye Wastewater and simultaneous Hydrogen Production

Abstract

In this work a continuously operated electrocoagulation process with sacrificial aluminum electrodes is presented for decolorization of aqueous solution containing nickel phthalocyanine reactive dye and simultaneous production of electrolytic hydrogen. The electrocoagulator is equipped with a gas separation tank for harvesting the electrochemically generated hydrogen gas at the cathode. Hydrogen, compared to common fossil fuels, is a clean alternative fuel of high caloric value and zero emission. The need for hydrogen has been increasing rapidly. In recent years, a major concern is to obtain hydrogen and energy from waste and industrial effluents by using them as an energy source. Electrocoagulation has proved to combine efficient removal of pollutants, such as recalcitrant dyes from wastewaters and simultaneously production of hydrogen gas at the cathode. The influence of all operating parameters on the dye removal efficiency and hydrogen production, such as wastewater pH, conductivity, current density, and inlet flow rate were investigated.Experimental results showed that the quality of the treated wastewater was very satisfactory. By working at the optimal parameters i.e. initial pH 8 and current density 10 mA/cmx2, the dye was completely removed (>99.9 %). The energy yield via the harvested hydrogen amounted to 12.5 % of the electrical energy needed for running the electrocoagulation process