EQUILIBRIUM AND KINETICS OF CR(VI) EXTRACTION WITH ALIQUOT 336

Solvent extraction has been reported as a useful technology for the recovery of Cr(VI) from industrial effluents. The equilibrium and kinetics of the solvent extraction process based on a complex organic phase (0.5% Aliquat 336,5% n-decanol, and kerosene as diluent) have been studied. The influence of the chromium(VI) concentration on the distribution coefficient has been fitted by a semiempirical model, which allows evaluation of the equilibrium conditions in the mass-transfer kinetic model. A mass-transfer coefficient in the organic phase k(o) = 1.64 X 10(-3) s-1, according to the film theory, or an effective diffusion parameter D(eff)/R2 = 5.03 X 10(-4) s-1, according to a radial diffusion model, describes the mass-transfer kinetics of the process.