This contribution provides insight on the elimination of heavy metals from water resources using magnetic separation. Nanocomposites based on magnetite and chitosan were prepared. An exhaustive characterization of the magnetic adsorbents was developed. Adsorption assays were performed in batch using Cu, Zn, Cd, and Cr as model heavy metals. The efficiency of magnetic adsorbents followed the order: Cu > Cd > Zn > Cr, with maximum values of 188, 159, 72, and 46 mg of Me/g of nanocomposite, respectively. Kinetics and mechanistic issues were studied. The magnetic materials were efficient for five to eight cycles using Cu(II),Cd(II), and Cr(VI).

Efficient adsorbent ferrogels based on gelatin and dextrose were synthetized using freeze-thawing technique. Two different methodologies of magnetic particles incorporation were developed. An exhaustive morphologic and thermal characterization of hydro and ferrogels was achieved. The performance of ferrogel in water remediation was tested using Cd(II) as model contaminant. The adsorption ability was evaluated as a function of pH, initial heavy metal concentration, and contact time. The maximum adsorption capacity was 35 mg of Cd(II)/g of adsorbent. Ferrogel was regenerated by washing with distilled water, maintaining efficiency of almost 30% after the fourth cycle. GRAPHICAL ABSTRACT