Magnetoactive Humic‐Based Nanocomposites

We have elaborated several approaches for the preparation of magnetoactive nano-hybrid composites, including i) ex situ method, which consists of the precipitation of magnetic particles from Fe(II) and Fe(III) salts followed by their incorporation into the humic acids matrix and ii) a chemical precipitation method in situ where the magnetic particles are grown within the humic acids matrix. It was proven that adsorption of humic acids on the magnetic particle surface leads to an enhanced electrostatic and steric stabilization of particles, due to the absorbed layer of highly charged macromolecular compounds. The sorbents under study were found to reveal a high sorption capacity towards uranyl ions. Using the adsorption isotherm, in the linear form of the Langmuir equation, the adsorption parameters were estimated. The results obtained show that the adsorption of uranyl ions by the magneto-active nanocomposite is enhanced in comparison with the free HA.