Characterization of Multiphase Oxide Layer Formation on Micro and Nanoscale Iron Particles

The article presents a detailed study and characterization of the oxide layers on the surface of iron particles of various sizes. Ten iron samples with a size range from a few nm to 50 µm were studied in detail using SEM, TEM, XRD, and TGA analysis. The composition of the multiphase oxide layers on the powder surface was investigated. The main components of the oxide layer were FeO, Fe3O4, and Fe2O3. By the obtained data, a model for the calculation of a multiphase oxide layer thickness on the surface of iron particles was proposed. The proposed model was validated and can be used for the characterization and certification of micro– and nanoscale iron particles.

Green Synthesis of Iron Nanoparticles: Application on the Removal of Petroleum Oil from Contaminated Water and Soils

Iron nanoparticles were produced using the extract of mortiño berry (Vaccinium floribundum) (vZVI) as reducing and stabilizer agent. Fresh nanoparticles were characterized using TEM, XRD, and FTIR techniques, while laboratory experiments were conducted to assess the removal of total petroleum hydrocarbons (TPHs) from water and soil after treatment with synthesized nanoscale iron particles. Nanoparticles as produced were spherical in the range of 5–10 nm. After treatment with vZVI nanoparticles, water contaminated with two concentrations of TPHs (9.32 mg/L and 94.20 mg/L) showed removals of 85.94% and 88.34%, respectively, whereas a contaminated soil with a TPHs concentration of 5000 mg/kg treated during 32 h with nanoparticles reached a removal of 81.90%. Results indicate that the addition of vZVI nanoparticles produced strong reducing conditions, which accelerate removal of TPHs and suggest that these nanoparticles might be a promising technology to clean up TPHs contaminated water and soils.