The paper describes the results obtained by synthesis and characterization of iron oxides nanoparticles functionalized with natural polymers (dextran, chitosan) for water decontamination. The experiments consisted in synthesis of iron oxide nanoparticles, functionalizing them with Dextrane and Chitosan and their characterization. For the synthesis of iron nanoparticles the co-precipitation technique was used, while for the characterization were used techniques such as scanning electron microscopy, transmission electron microscopy, X-Ray diffraction spectrometry. The morphology experiments certified the obtaining of iron oxide nanoparticles functionalized with natural  polymers with agglomeration tendency.  The obtained nanoparticles can be used in the environmental engineering field, as adsorbent particles for heavy metals removal (Cr, Zn, Pb). The removal efficiency was about 78% in case of Zn and Pb removal and 92% for Cr removal.