Removal of cesium ions using nickel hexacyanoferrates-loaded bacterial cellulose membrane as an effective adsorbent

Abstract

Radiocesium is a major fission product that has negative effects on ecosystems and human health due to its radioactivity and chemical toxicity. Metal hexacyanoferrates (MHCF), as efficient adsorbent for cesium removal has aroused great interest because of their high selectivity and adsorption capacity for cesium ions. In this study, a novel biosorbent, sodium nickel hexacyanoferrates-loaded bacterial cellulose membrane (BC/NiHCF), was prepared by loading NiHCF in porous and shape controllable bacterial cellulose (BC). The as-prepared biosorbent presented porosity, flexibility, and good stability in aqueous solutions, and showed a good adsorptive removal capacity for cesium ions. The effect of experimental conditions (e.g. contact time and initial cesium ion concentration) on the uptake of Cs+ was examined. For adsorption kinetics, the data was best described by the pseudo-second-order model with R2 = 0.998; for adsorption isotherms, the data could be efficiently modelled by the Langmuir model (R2 = 0.9715). Meanwhile, its maximum adsorption capacity was estimated to be 175.44 mg g−1, indicating the showcase adsorbent was efficient for Cs+ removal. Additionally, the adsorption mechanism was tentatively proposed. In a word, BC/NiHCF exhibited great adsorption performance towards Cs+.