Amino Acid Functionalized Chitosan Magnetic Nanobased Particles for Uranyl Sorption

Abstract

Nanobased magnetic particles are synthesized by a one-pot hydrothermal precipitation of chitosan in the presence of iron(II) and iron(III) salts. The material is then chemically modified by grafting alanine and serine amino acids. These materials are characterized by elemental analysis, FTIR spectrometry, XRD analysis, TEM observations, and VSM (vibrating-sample magnetometry). In a second step, these materials are tested for uranium(VI) sorption. The effect of pH on sorption performance is first investigated before evaluating uptake kinetics (which are fitted by the pseudo-second-order rate equation) and sorption isotherms (which are modeled by the Langmuir equation). Metal desorption and sorbent recycling are finally carried out for five successive cycles of sorption/desorption. Thermodynamic parameters are determined by investigating sorption properties at different temperatures. Maximum sorption capacities reach 85 and 116 mg U g–1 for alanine- and serine-based sorbents, respectively. The magnetic properties of the particles allow their efficient separation from the solution by external magnetic field.