Carrier-mediated transport of Hg(II) through bulk and supported liquid membranes

Abstract

The transport of Hg (II) ions from an aqueous solution into an aqueous receiving solution through bulk and supported liquid membranes containing a calix[4]arene derivative 1 as a carrier was examined. The kinetic parameters of bulk liquid membrane studies were analyzed assuming two consecutive, irreversible first-order reactions. The influence of temperature, stirring rate, carrier concentration and solvent on the kinetic parameters (k1, k2, Rmmax, tmax, Jdmax, Jamax) has also been investigated. The membrane entrance rate, k1, and the membrane exit rate, k2, increased with increasing temperature and stirring rate. The activation energy values are calculated as 4.87 and 48.63kjmol-1 for extraction and reextraction, respectively. The values of calculated activation energy indicate that the process is diffusionally controlled by species. Also, the transport behavior of Hg2+ from aqueous solution through a flat-sheet supported liquid membrane has been investigated by the use of calix[4]arene derivative 1 as carrier and Celgard 2500 as the solid support. A Danesi mass transfer model was used to calculate the permeability coefficients for each parameter studied. The highest values of permeability were obtained with 2-nitrophenyloctyl-ether (NPOE) solvent and the influence was found to be in the order of NPOEchloroformxylene.