Removal of cadmium and production of cadmium powder using a continuous undivided electrochemical reactor with a rotating cylinder electrode

J. M. GRAU; J M. BISANG

JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY

John Wiley & Sons, Ltd

Lugar: Norwich; Año: 2002 vol. 77 p. 465 - 472

0268-2575

The behaviour of a continuous undivided electrochemical reactor with a rotating cylinder electrode under potenciostatic control is examined for the abatement of cadmium from synthetic sodium sulfate solutions with Cd(II) concentrations lower than 500 mg.dm-3 at a reactor inlet pH=7. The process was designed to convert the metal ions in solution to metal powder, which settles to the conical of the reactor and may be removed at intervals as a sludge by opening a drop valve.  The effect of applied potential, inlet cadmium concentration, rotation speed and hydrogen evolution as side for cathodic reaction on the “ figures of merit” of the reactor are analyzad. The best results were obtained for cathodic potential in the range from -0.9V to -1.0V against the saturated calomel electrode. Therefore, when the rotation speed was 1000 rpm the space time yield and the normalizad space velocity were 0.64x102 mol.m-3.s-1 and 0.89 h-1 respectively, while the fractional conversion per pass was 35% with a current efficiency higher than 74%. The surface morphology of the deposits as a function of the process variables is also reported