Removal of cesium ions from aqueous solutions using immobilized nickel hexacyanoferrate-sericite beads in the batch and continuous processes

Abstract

Powdered sericite impregnated into nickel hexacyanoferrate (NiHCF-sericite) was immobilized as a bead form by entrapment method using sodium alginate. The immobilized NiHCF-sericite beads have excellent mechanical strength and the increase of pressure drop caused channeling of flow was not observed through column processes even though long time operation. The existence of cesium ions onto the surface of the immobilized NiHCF-sericite beads was verified by the scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The maximum adsorption capacity for cesium ions of immobilized NiHCF-sericite beads was determined as the 13.877mg/g at the initial pH 5.0 of aqueous solution and the equilibrium data followed well the linearized Langmuir isotherm equation which has the higher correlation coefficient (0.993). The breakthrough point was emerged around 50 (1.0mL/min) and 80 bed volumes (0.5mL/min) and the bed volumes can be still maintained as the 75 even though secondary reused immobilized NiHCF-sericite beads were used.