Polyphosphate‐Grafted Fe₃O₄ Nanomagnets for the Removal of Trivalent Radionuclides from Acidic Nuclear Waste Solution

Abstract

The removal of radionuclides from nuclear waste solution is one of the biggest environmental challenges in today's world. In this aspect, polyphosphate grafted Fe 3 O 4 nanomagnets (PPNMs) were investigated for its efficiency in removal of trivalent radionuclides from acidic nuclear waste solution. Various characterization techniques like XRD, FTIR, TEM and DLS were used to characterize these PPNMs, which showed successful formation of single phase, polyphosphate functionalized aqueous stable Fe 3 O 4 nanostructure with average size ∼ 10 nm. The kinetics of sorption for Am(III) and Eu(III) by the PPNMs was found to be very fast with equilibrium being attained within ∼ 5 min. The sorption of both the radionuclides was following pseudo second order kinetic model. With increasing pH of the solution, the sorption efficiency of PPNMs for both the radionuclides was found to increase, whereas it decreased with increasing ionic strength of the medium. These observations clearly suggested that the sorption process proceeds through electrostatic interaction between the nanomagnets and trivalent radionuclides. Moreover, the PPNMs retained their sorption efficiency for at least 10 successive cycles when desorbed with 0.2 M HNO 3 . Thus, these magnetic nanosorbents can be used as highly effective, separable and reusable materials for removal of trivalent radionuclides from acidic nuclear waste solution.