Selective transport of mercury as HgCl42- through a bulk liquid membrane using K+-dicyclohexyl-18-crown-6 as carrier

Potassium-dicyclohexyl-18-crown-6 cation complex was used as an excellent carrier for the selective and efficient transport of mercury as HgCl42- complex anion through a chloroform bulk liquid membrane. In the presence of thiocyanate ions as a suitable stripping agent in the receiving phase at optimum experimental conditions. the amount of mercury transported across the liquid membrane after 2 h was 95.4 +/- 1.5%. The selectivity of mercury transport from aqueous solutions containing other cations. such as Li+, Tl+, Co2+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2-, Fe3+ and Cr3+, was investigated. With the exception of Mg2+ and Ca2+ with some potential interference, in all other cases, the interfering effect or the cations was found to be negligible: most of the cations did not interfere with the mercury transport even at a Mn+/Hg2+ molar ratio of greater than or equal to 100. (C) 2001 Elsevier Science B.V. All rights reserved.