Transport of Hg2+ through bulk liquid membrane using a bis-calix[4]arene nitrile derivative as carrier: kinetic analysis

Abstract

The transport of Hg(II) ions from an aqueous solution into an aqueous receiving solution through a bulk liquid membrane containing a bis-calix[4]arene nitrile derivative (1) as a carrier was examined. The kinetic parameters were analyzed assuming two consecutive, irreversible first-order reactions. The influence of temperature, the solvent and stirring rate on the kinetic parameters (k₁, k₂, R_m^max, t_max, J_d^max, J_a^max) has also been investigated. The membrane entrance rate, k₁, and the membrane exit rate, k₂, increased with increasing temperature and stirring rate. The membrane entrance and exit rate constants are found to vary in the order CH₂Cl₂ > CHCl₃ > CCl₄. For the maximum membrane exit flux, J_a^max, the activation energy was found from the slope of the linear Arrhenius relationship to be 9.95 kcal mol⁻¹, which indicates that the process is controlled by species diffusion.