Ultra-efficient removal of chromium from aqueous medium by biogenic iron based nanoparticles

Iron based nanoparticles were synthesized through an eco-friendly one-step reaction of FeCl3 and Syzygium jambos (L.) Alston leaf extract in water. The morphology and structure of the SJA-Fe nanoparticles were characterized by UV-vis, TEM and XRD. The obtained biogenic SJA-Fe nanoparticles demonstrated very high efficiency in removing chromium Cr(VI), a toxic pollutant in surface and ground water. The removal capacity as high as 983.2 mg Cr(VI)/g Fe was achieved. It was found that increased temperature and lowered pH were favored in the Cr(VI) removal. In addition, most of the typical coexisting substances such as humic acid showed insignificant effects on Cr(VI) removal. A pseudo second-order model was developed to simulate the kinetics of this process. Furthermore, a reaction mechanism was proposed.