Electrochemical removal of cadmium using a batch undivided reactor with a rotating cylinder electrode

Abstract

The performance of an undivided electrochemical batch reactor with a rotating cylinder electrode under potentiostatic control is examined for the removal of cadmium from a sodium sulfate solution containing 500ppm Cd(II) at pH ≅ 7. The effect of hydrogen evolution as a side cathodic reaction on the figures of merit of the reactor is analysed. The best results were obtained for a cathode potential of -0.9 V against the saturated calomel electrode. With an angular velocity of 1500rpm the space time yield and the normalized space velocity were 0.66 mol m-3s-1 and 3.9 h-1 respectively, while the fractional conversion was 67.3% with a current efficiency of 66.7%. The surface morphology of the deposits as a function of the applied potential is also reported. © 2001 Society of Chemical Industry.