Selective and efficient transport of Hg(II) through bulk liquid membrane using methyl red as carrier

Abstract

Methyl red was used as an excellent carrier for the uphill transport of Hg(II) through bulk liquid membrane. By using iodide as a metal acceptor and in the presence of sulfuric acid in receiving phase the amount of mercury transport across the bulk liquid membrane was about 90% after 180 min. By replacement of the above receiving phase with 0.45 M HCl, a simpler and more reproducible system was obtained. Oleic acid was used to overcome a minor leaching of the carrier into the aqueous phase at high acid concentration. This system was optimized with a simplex optimization program. Under optimum conditions, the amount of Hg(II) transport across the liquid membrane is about 80% after 150 min. The carrier can selectively and efficiently transport Hg2+ ion from aqueous solution containing other cations such as Cd2+, Zn2+, Cu2+, Mg2+, Ca2+, Ag+, Ni2+, Al3+, Na+, Pb2+, Fe3+ and Pd2+.