Kinetic analysis of coupled transport of thiocyanate ions through liquid membranes at different temperatures

Non-steady-state kinetics of coupled transport of thiocyanate ions through liquid membrane (trichloromethane), containing hexadecyl trimethyl ammonium chloride as a carrier, was examined at different temperatures. The kinetics of thiocyanate transport could be analyzed in the formalism of two, consecutive, irreversible first order reactions. The influence of temperature on the kinetic parameters (k(ld), k(2m), R-m(max), t(max), J(d)(max), J(a)(max)) have been also investigated. The membrane entrance rate, k(ld), and the membrane exit rates, k(2m) and k(2a), increase with temperature. For maximum membrane entrance and exit fluxes, J(d)(max) and J(a)(max), the activation energies were found from the slopes of the two linear relationships: 7.75 and 8.30 kcal/mol, respectively. The values of the found activation energy indicate that the process is controlled by species difussion.