title: Optimizing magnetic nanoparticles for drinking water technology: The case of Cr(VI).
abstract: The potential of magnetite nanoparticles to be applied in drinking water treatment for the removal of hexavalent chromium is discussed. In this study, a method for their preparation which combines the use of low-cost iron sources (FeSO4 and Fe2(SO4)3) and a continuous flow mode, was developed. The produced magnetite nanoparticles with a size of around 20 nm, appeared relatively stable to passivation providing a removal capacity of 1.8 μg Cr(VI)/mg for a residual concentration of 50 μg/L when tested in natural water at pH7. Such efficiency is explained by the reducing ability of magnetite which turns Cr(VI) to an insoluble Cr(OH)3 form. The successful operation of a small-scale system consisting of a contact reactor and a magnetic separator demonstrates a way for the practical introduction and recovery of magnetite nanoparticles in water treatment technology.
authors.affiliation: Department of Mechanical Engineering, School of Engineering, University of Thessaly, Volos 38334, Greece. Electronic address: ksime@physics.auth.gr.
authors.forename: K
authors.initials: K
authors.lastname: Simeonidis
authors.affiliation: Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Kaprara
authors.affiliation: Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: T
authors.initials: T
authors.lastname: Samaras
authors.affiliation: Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: M
authors.initials: M
authors.lastname: Angelakeris
authors.affiliation: Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: N
authors.initials: N
authors.lastname: Pliatsikas
authors.affiliation: Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Vourlias
authors.affiliation: Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: M
authors.initials: M
authors.lastname: Mitrakas
authors.affiliation: Department of Mechanical Engineering, School of Engineering, University of Thessaly, Volos 38334, Greece.
authors.forename: N
authors.initials: N
authors.lastname: Andritsos
mesh_terms: D002857:Chromium / Q000032:analysis / Q000737:chemistry*; D060766:Drinking Water / Q000737:chemistry*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water; D058185:Magnetite Nanoparticles; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion
keywords: Drinking water; Hexavalent chromium; Magnetic nanoparticles; Magnetic separation