Extraction of mercury(II) with dicyclohexano-18-crown-6, and its application to industrial wastes

As part of the study of hazardous metal ion separation from industrial wast es, the extraction behavior of Hg(II) from dilute hydrochloric acid solutio ns with dicyclohexano-18-crown-6 (DC18C6) in 1,2-dichloroethane was investi gated. For comparison, extraction studies also were carried out with 18-cro wn-6 (18C6), benzo-18-crown-6 (B18C6), and dibenzo-18-crown-6 (DB18C6). The extraction data were analyzed by both graphical and theoretical methods th at account for aqueous phase complexation with inorganic ligands and all pl ausible complexes extracted into the organic phase. The results demonstrate that Hg (II) is extracted into dichloroethane as HgCl2.2Crown Ether. The H gCl2.DC18C6 solid complex was prepared and characterized by elemental analy sis, and IR (infrared) and H-1-NMR (nuclear magnetic resonance) spectral st udies. The possible means of extracting and separating Hg(II) from other me tal ions, such as Mg(II), Ca(II), Ba(II), and Fe(III), that are present in the industrial wastes of the chlor-alkali industry is discussed. The potent ial of the DC18C6 for decontaminating mercury from the brine sludge of a ch lor-alkali plant has been assessed.