title: Remediation of mercury contaminated saltwater with functionalized silica coated magnetite nanoparticles.
abstract: The study aimed to evaluate the efficiency of dithiocarbamate functionalized silica coated magnetite nanoparticles (NPs) for Hg decontamination of saltwater either contaminated with Hg alone or with As and Cd. For this, the residual levels of Hg in seawater were assessed and Hg-contaminated or Hg+As+Cd-contaminated seawater toxicity to aquatic biota, before and after the sorption process, was compared. The results showed that under highly competitive conditions (water salts, Cd and As), the removal of Hg from seawater, by using these magnetic NPs, for the lowest concentration (50μg/L) was superior to 98% and for the highest concentration (500μg/L) ranged between 61% to 67%. Despite the great affinity of the magnetic NPs for Hg, they were not effective at removing As and Cd from seawater. In relation to the ecotoxicity endpoints after remediation, the mixture with lower Hg concentration exhibited no toxicity to rotifer Brachionus plicatilis and bacteria Vibrio fischeri ; however, the mixture with higher concentration revealed toxicity. In addition, the toxicity of bacteria V. fischeri, rotifer B. plicatilis and algae Phaeodactylum tricornutum, whose responses where inhibited during its exposure to the non-remediate sample was considerably reduced after treatment with NPs. Furthermore, microalgae P. tricornutum appears to be most sensitive species while Artemia franciscana showed no toxic effects to the tested solutions. Both chemical and ecotoxicological approaches revealed a high efficiency for the remediation of Hg-contaminated saltwater.
authors.affiliation: CESAM and Department of Chemistry, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Iram
authors.initials: I
authors.lastname: Mohmood
authors.affiliation: CICECO and Department of Chemistry, Campus de Santiago, 3810-193 Aveiro, Portugal; CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas 289, 4050-123 Porto, Portugal.
authors.forename: Cláudia B
authors.initials: CB
authors.lastname: Lopes
authors.affiliation: CESAM and Department of Biology, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Lopes
authors.affiliation: CESAM and Department of Chemistry, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Daniela S
authors.initials: DS
authors.lastname: Tavares
authors.affiliation: CESAM and Department of Biology, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Amadeu M V M
authors.initials: AM
authors.lastname: Soares
authors.affiliation: CESAM and Department of Chemistry, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Armando C
authors.initials: AC
authors.lastname: Duarte
authors.affiliation: CICECO and Department of Chemistry, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Tito
authors.initials: T
authors.lastname: Trindade
authors.affiliation: Centre for Occupational and Environmental Health, Centre for Epidemiology, Institute of Population Health, Faculty of Medical and Human Sciences, The University of Manchester, Manchester M13 9PL, UK.
authors.forename: Iqbal
authors.initials: I
authors.lastname: Ahmad
authors.affiliation: CESAM and Department of Chemistry, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Eduarda
authors.initials: E
authors.lastname: Pereira
mesh_terms: D052918:Environmental Restoration and Remediation / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008628:Mercury / Q000737:chemistry*; D012623:Seawater / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000633:toxicity; D018508:Water Purification / Q000379:methods*
chemical_list: D058185:Magnetite Nanoparticles; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; D008628:Mercury
keywords: Ecotoxicological effects; Mercury; Nanoparticles; Remediation; Seawater