High-stability polyamine/amide-functionalized magnetic nanoparticles for enhanced extraction of uranium from aqueous solutions

In this work, carbon-coated magnetic iron oxide nanoparticles (CCM) functionalized with polyethyleneimine/amide (PEIA) were successfully prepared. The prepared nanocomposite (CCMNPs-PEIA) was characterized by XRD, TEM, FT–IR, TGA and VSM techniques. The stability of CCM was tested in both acidic and basic media and they showed a high stability with good magnetic properties. CCMNPs-PEIA were used for separation of U (VI) from aqueous solutions. Several process parameters were tested to investigate the removal efficiency, adsorption capacity and reusability of the CCMNPs-PEIA including, pH, initial concentration of uranium, and desorption and activation media. The CCMNPs-PEIA nanocomposite was found to have excellent affinity toward U over a wide pH range. Surface oxidation of CCM was found to be of major effect of the adsorption capacity of CCMNPs-PEIA due it carboxylation which enhanced PEIA attachment to the carbon surface. The experimental uptake of the prepared nanocomposite was found to be 127.5 mg (U/g (nanocomposite), while the one calculated according to Langmuir model was found to be 123.45 mg/g with a correlation coefficient (R²) of 0.991. The kinetics analysis of the adsorption process suggests that the kinetics can be described well by the pseudo-second order model suggesting that the rate limiting step is chemisorption.