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

The removal of radionuclides from nuclear waste solution is one of the biggest environmental challenges in today's world. In this aspect, polyphosphate grafted Fe3O4 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 Fe3O4 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 HNO3. Thus, these magnetic nanosorbents can be used as highly effective, separable and reusable materials for removal of trivalent radionuclides from acidic nuclear waste solution. Polyphosphate grafted Fe3O4 nanomagnets (PPNMs) were synthesized with subsequent characterization by XRD, FTIR, TEM and DLS. The synthesized material was found to be effective for the removal of trivalent radionuclides showing fast kinetic of sorption. The mechanism of sorption was found to be chemisorption which folloed pseudo 2nd order kinetics and Langmuir adsorption isotherm. The synthesized nanomagnets were found to be effective, easily separable and reusable material for the removal of trivalent radinuclides from waste solution in the pH range.