New Method of Synthesis of Stable Zero Valent Iron Nanoparticles (Nzvi) by Chelating Agent Diethylene Triamine Penta Acetic Acid (DTPA) and Removal of Radioactive Uranium From Ground Water by using Iron Nanoparticle

Nowdays, iron nanoparticles due to their unique characteristics are used in all of sciences and technology. These nano particles due to their electrical, magnetic, optical and catalytic properties and having high area and activity that is promped by their small size and most importantly many scientists from the entire world are interested in their low cost production. In this project we used method of reduction in the liquid phase for synthesis of iron nano particles. Unlike synthesis so far has been done and they used different kinds of surfactants and capping or they used starch for stabilization, we used chelating agent diethylene triamine penta acetic acid (DTPA) for increasing the stability of iron nano particles for the first time in the world. Ammonium iron(II) sulfate were used for make iron nano particle and Sodium borohydride was used for reduction. This method not only was simple and cheap but also didn’t need special instruments. Also determining of structure, size, particles distribution and surface morphology of this nano particles we used the analysis of FT-IR, XRD and SEM that all of them showed the synthesis of zero valent iron nanoparticles, metallic iron, has been done correctly. The average of synthesis of zero valent iron nano particles is 18 nm and crystal structure of nano particles was designed by using vertical nano lab software. Finally, we studied opration Removal of Radioactive Uranium From groundwater by using iron nanoparticle. 2012 JNS All rights reserved 176 A. Akbari / JNS 2 (2012) 175-181 For example, He et al. [3] reported that by using food-grade water soluble starch both the disposability and the reactivity of Fe nanoparticles were improved. But the starch stabilized Fe became less stable, as evidence by the appearance of floc precipitates after 2 days, thereby limiting long-term storage and commercial application of these Fe nanoparticles. Also, Niu et al. [2]. Used starch during the synthesis of nZVI as dispersing cum stabilizing agent and according to He et al. [4] A stock solution of Fe(II) was added to the CMC solution to prepare desired concentration of Fe and CMC. The mixture was purged with N2 for 15min to complete the formation of the Fe-CMC complex. The Fe(II) ions were then reduced to Fe(0) using sodium borohydride to the mixture. But we used chelating agent Diethylene Triamine Penta Acetic acid (DTPA) for increasing the stability of iron nano particles for the first time in the world. Chelation is the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central atom. Usually these ligands are organic compounds, and are called chelants, chelators, chelating agents, or sequestering agents.The ligand forms a chelate complex with the substrate. Chelate complexes are contrasted with coordination complexes composed of monodentate ligands, which form only one bond with the central atom.Chelants, according to ASTM-A-380, are "chemicals that form soluble, complex molecules with certain metal ions, inactivating the ions so that they cannot normally react with other elements or ions to produce precipitates or scale ".