Magnetic chitosan composite particles: Evaluation of thorium and uranyl ion adsorption from aqueous solutions

Magnetic chitosan composite particles with 40 μm average size and 24 emu/g saturation magnetization obtained by an in situ procedure were evaluated as a new low-cost adsorbent for radioactive wastewater decontamination. Sorbent characterization by SEM, EDX, FTIR and magnetization measurements proved that the target ions were bound and their surface distribution was uniform. The 18 emu/g magnetization of the metal loaded particles was high enough to ensure their easy magnetic field separation and recovery. The parameters influencing the sorption process were optimized with respect to sorbent mass, target ion concentration and contact time. The material under study had superior adsorption capacity both for uranyl (666.67 mg/g) and thorium (312.50 mg/g) ions when compared to other low-cost adsorbents reported in literature. The adsorption process is spontaneous and endothermic. The material may be regenerated and re-used.