Graphene-prussian blue nanocomposite impregnated in alginate for efficient removal of cesium from aquatic environment

Abstract

Simple hydrothermal reaction followed by displacement reaction was used for preparation of prussian blue graphene oxide alginate (PB-GO-Alg) composite in beads form for highly efficient removal of Cs isotopes from aquatic environment. The optimum composition of the beads was 5% loading of PB (Prussian blue)-GO(Graphene Oxide) nanoparticles into 4% Ca-alginate matrix. GO upon functionalization with PB which is a zeolite-like inorganic materials capable of exchange of its K ions for Cs ions. Due to the combined effects of GO, PB and host alginate matrix, the hybrid beads showed excellent removal efficiency (>98%) for Cs isotopes from different aquatic environments. Sorption isotherm followed the Langmuir model (linear regression correlation = 0.95) and the maximum sorption capacity of Cs was calculated to be 290.6 mg g−1. Kinetic study showed that the uptake was following the pseudo second order rate law. The beads were effective at pH5-7 (uptake >98%) for Cs removal and the equilibrium time required was 6 h.Mechanism of sorption was proposed based on the zeta potential values of the GO and PB-GO nanocomposites at different pH. The developed hybrid beads hold great promise to be used in case of any nuclear eventualities to decontaminate Cs contaminated water without disturbing the water quality parameters.