Enhanced adsorption of cesium on PVA-alginate encapsulated Prussian blue-graphene oxide hydrogel beads in a fixed-bed column system

A continuous fixed-bed column study was performed using PVA-alginate encapsulated Prussian blue-graphene oxide (PB-GO) hydrogel beads as a novel adsorbent for the removal of cesium from aqueous solutions. The effects of different operating parameters, such as initial cesium concentration, pH, bed height, flow rate, and bead size, were investigated. The maximum adsorption capacity of the PB-GO hydrogel beads was 164.5 mg/g at an initial cesium concentration of 5 mM, bed height of 20 cm, and flow rate of 0.83 mL/min at pH 7. The Thomas, Adams-Bohart, and Yoon-Nelson models were applied to the experimental data to predict the breakthrough curves using non-linear regression. Although both the Thomas and Yoon-Nelson models showed good agreement with the experimental data, the Yoon-Nelson model was found to provide the best representation for cesium adsorption on the adsorbent, based on the chi(2) analysis. (C) 2016 Elsevier Ltd. All rights reserved.