Selective Active Transport of Hg(II) using Sulfur-containing Derivatives of Liquid Polybutadiene

Abstract

From a view point of the control of environmental pollution, condensation of aqueous Hg (II) was studied. This con densation, that is an active transport, was performed by assembling a system from a source aqueous phase, a receiving aqueous phase including halide salt, and a filter-impregnated liquid membrane which separated the two aqueous phases. Liquid polybutadiene (LPB), epoxidized LPB (LE), and methylthio-substituted LPB derivatives (LSMe) were found to have the ability of selective active transport of Hg(II) when used as the liquid membrane in a mixture with o-nitrophenyl octyl ether. Unsaturated linkage in LPB, epoxy rin g in LE, and sulfide linkage in LSMe are all estimated as an active ingredient in liquid membrane to have interaction with Hg(II) and to induce the absorption of Hg(II) into the membrane from the source phase. The released Hg(II)from the membrane lies in an equilibrium with HgX₄^2- (X=halogen) in the receiving phase, which is inert to interact with the ingredient of membrane. Disappearance of this interaction suppresses reabsorption to the membrane and contributes to the active transport of Hg(II). Methylthio-substituted derivatives, among LPB derivatives tested, especially LSMe-b with higher concentration of sulfide linkage showed the best ability of selective active transport of Hg(II).