title: Core-shell magnetite-silica dithiocarbamate-derivatised particles achieve the Water Framework Directive quality criteria for mercury in surface waters.
abstract: The sorption capacity of nanoporous titanosilicate Engelhard titanosilicate number 4 (ETS-4) and silica-coated magnetite particles derivatised with dithiocarbamate groups towards Hg(II) was evaluated and compared in spiked ultra-pure and spiked surface-river water, for different batch factors. In the former, and using a batch factor of 100 m(3)/kg and an initial Hg(II) concentrations matching the maximum allowed concentration in an effluent discharge, both materials achieve Hg(II) uptake efficiencies in excess of 99 % and a residual metal concentration lower than the guideline value for drinking water quality. For the surface-river water and the same initial concentration, the Hg(II) uptake efficiency of magnetite particles is outstanding, achieving the quality criteria established by the Water Framework Directive (concerning Hg concentration in surface waters) using a batch factor of 50 m(3)/kg, while the efficiency of ETS-4 is significantly inferior. The dissimilar sorbents' Hg(II) removal efficiency is attributed to different uptake mechanisms. This study also highlights the importance of assessing the effective capacity of the sorbents under realistic conditions in order to achieve trustable results.
authors.affiliation: CESAM and Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193, Aveiro, Portugal. claudia.b.lopes@ua.pt
authors.forename: C B
authors.initials: CB
authors.lastname: Lopes
authors.forename: P
authors.initials: P
authors.lastname: Figueira
authors.forename: D S
authors.initials: DS
authors.lastname: Tavares
authors.forename: Z
authors.initials: Z
authors.lastname: Lin
authors.forename: A L
authors.initials: AL
authors.lastname: Daniel-da-Silva
authors.forename: A C
authors.initials: AC
authors.lastname: Duarte
authors.forename: J
authors.initials: J
authors.lastname: Rocha
authors.forename: T
authors.initials: T
authors.lastname: Trindade
authors.forename: E
authors.initials: E
authors.lastname: Pereira
mesh_terms: D004784:Environmental Monitoring; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D007700:Kinetics; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008628:Mercury / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry; D013859:Thiocarbamates / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
chemical_list: D058185:Magnetite Nanoparticles; D013859:Thiocarbamates; D014874:Water Pollutants, Chemical; D014867:Water; D008628:Mercury; D052203:Ferrosoferric Oxide