Electrochemical removal of cadmium from a sulphate solution using a three-dimensional electrode

Abstract

The aim of this study is to investigate the removal of cadmium from sulphate solutions via a batch cell by an electrochemical method. A cadmium/zinc couple was used to generate a spontaneous chemical reaction in the cell. Different parameters such as initial Cd(II) concentration, choice of electrode, and influence of pH were investigated in this work. After 2 h operation of the reactor with a three-dimensional electrode of reticulated vitreous carbon (RVC) cathode, more than 90% of cadmium was recovered from 10, 100 and 500 mg L−1 cadmium sulphate solutions. The electrogenerative system was successful in reducing 10 mg L−1Cd(II) to < 0.4 mg L−1 for 90 min, 100 mg L−1Cd(II) to <0.5 mg L−1 for 150 min, and for 500 mg L−1Cd(II) to <4 mg L−1 for 270 min. For porous graphite (PG) as the cathode material, to achieve 90% of removal, more time is needed especially for 500 mg L−1. Finally, the deposited cadmium was characterized using scanning electron microscopy (SEM), X-ray energy dispersive spectrometry (EDX) and X-ray diffraction (XRD).

Keywords

• Cadmium recovery
• Electrogenerative
• Porous graphite
• Reticulated vitreous carbon
• Three-dimensional electrode