In this work, Ricinus communis L. press cake waste from biodiesel production was used to produce a versatile reactive material for environmental applications.The biodiesel cake waste was impregnated with Fe III at different concentrations (19-45 wt.%) and treated at 400, 600 and 800 °C.Mössbauer, X-ray diffraction (XRD), thermogravimetric analysis (TG/DTA), scanning electron microscope (SEM), elemental analysis CHN, Raman, potentiometric titration, saturation magnetization and Brunauer-Emmett-Teller (BET) analyses showed that the materials prepared at 400 °C are composed mainly of a graphitic and amorphous carbon containing dispersed magnetite (Fe 3 O 4 ).At higher temperatures, metallic iron (Fe 0 ) and iron carbide (Fe 3 C) are the predominant phases well dispersed in the carbon porous structure.These reduced iron species, Fe 3 O 4 and Fe 0 , are active for the reduction of different hazardous contaminants.Preliminary experiments showed very high activities for the reduction and removal of aqueous Cr VI .