Reticulated vitreous carbon as cathode in electrodeposition of cadmium

Three-dimensional porous electrodes have been used in the effluent electrochemical treatment for removing harmful heavy metals from environment. These high surface area electrodes lead to turbulent mass transport conditions to the electrode surface where enhanced electrochemical deposition rate is achieved. Great numbers of porous electrodes have been used for a long time. Nowadays, the tendency is to use reticulated materials such as reticulated vitreous carbon (RVC) or metallic foam as cathodic materials for removing heavy metal ions from diluted solutions. Reticulated vitreous carbon has a regular and reticulated texture, high porosity, high internal surface area and high surface/volume ratio. RVC is almost exclusively made of vitreous carbon with enhanced chemical stability in a wide temperature range, low thermal conductivity and good electrical conductivity. An electrolytic cell with RVC cathode was developed in our laboratory. This cell was efficient for removing cadmium from concentrations in the range of 50-100 ppm. A current efficiency of 22% and a final cadmium ion concentration of 0.17 ppm were obtained under favorable conditions. A scaled-up cell for the purification of the waste effluent from a local plating industry is under development.