Kinetic Study in Bulk Liquid Membranes

Kinetic study of the transport of different chemical species through bulk liquid membranes has been widely studied, including metallic ions (Cu⁺², Co⁺², Cr⁺⁶, Hg⁺², Na⁺, Pd⁺², U⁺⁶), anionic species (CN⁻, SCN⁻, Cl⁻), dyes (methylene blue, cibacron red FN-R), amino acids (valine, phenylalanine), and other compounds. Most of these studies have employed carrier-mediated transport mechanisms by using different types of carriers and organic diluents in the membrane phase and different stripping agents in the product phase. Dimensionless reduced concentrations of the target species in the feed (R_f), membrane (R_m,), and product phases (R_p) were used (R_f=C_ft/C₀; R_m=C_mt/C₀; R_p=C_pt/C₀; the sum R_f +R_m+R_p obviously being unity).

In most of these studies, the variation with time of the reduced concentrations of target species decreased monoexponentially in the feed phase, followed an increasing sigmoided-type curve in the product phase and presented a maximum in the membrane phase (Fig. 1).

Kinetic...