Adsorption Isotherms for Cesium Ions in Seawater of Insoluble Cobalt and Nickel Ferrocyanide-Impregnated Fibers

Abstract

Cobalt or nickel ferrocyanide was impregnated into an anion-exchange polymer chain grafted onto a commercially available 6-nylon fiber. First, ferrocyanide ions (Fe (CN)₆^4－) were bound to the anion-exchange fiber. Second, the fiber was made to reach with cobalt or nickel ions to form insoluble cobalt or nickel ferrocyanide via precipitation. For comparison, a commercially available anion-exchange bead was used as a support for the impregnation of insoluble cobalt or nickel ferrocyanide. The contents of metal ferrocyanides impregnated onto the fiber were approximately half those impregnated onto the bead. Adsorption isotherms of insoluble cobalt or nickel ferrocyanide-impregnated fiber and bead for cesium ions in seawater correlated well with a Langmuir-type isotherm. The saturation capacity for cesium ions in seawater per gram of insoluble metal ferrocyanides was almost identical between the fiber and the bead.