title: Effects of mineral amendments on trace elements leaching from pre-treated marine sediment after simulated rainfall events.
abstract: Bauxite extraction by-products (red mud) were used to evaluate their potential ability to stabilize trace elements from dredged and aerated/humidified marine sediment. The investigated by-products were: bauxaline®(BX) that is a press-filtered red mud; bauxsol™(BS) that is a press-filtered red mud previously washed with excess of seawater, and gypsum neutralized bauxaline®(GBX). These materials were separately mixed to dredged composted sediment sample considering 5% and 20% sediment: stabilizer ratios. For pilot experiments, rainfall events were regularly simulated for 3 months. Concentrations of As, Mo, Cd, Cr, Zn, Cu, and Ni were analyzed in collected leachates as well as toxicity. Results showed that Cd, Mo, Zn, and Cu were efficiently stabilized in the solid matrix when 20% of BX, BS, and GBX was applied. Consequently, toxicity of leachates was lower than for the untreated sediment, meaning that contaminants mobility was reduced. A 5% GBX was also efficient for Mo, Zn and Cu stabilization. In all scenarios, As stabilization was not improved. Compared to all other monitored elements, Mo mobility seemed to depend upon temperature-humidity conditions during pilot experiments suggesting the need of further investigations.
authors.affiliation: Laboratoire de Physique de la Matière Condensée, UMR CNRS 7336, Université de Nice Sophia Antipolis, 28 avenue Valrose, 06108 Nice Cedex 2, France. Electronic address: charlotte.hurel@unice.fr.
authors.forename: C
authors.initials: C
authors.lastname: Hurel
authors.affiliation: Laboratoire Ecosystèmes Marins et réponse aux stress (ECOMERS), FRE CNRS 3729, Université de Nice Sophia Antipolis, 28 avenue Valrose, 06108 Nice Cedex 2, France.
authors.forename: M
authors.initials: M
authors.lastname: Taneez
authors.affiliation: Department of Environmental Sciences, Informatics and Statistics, University Ca' Foscari Venice, Via Torino 155, 30172 Venezia-Mestre, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Volpi Ghirardini
authors.affiliation: Department of Environmental Sciences, Informatics and Statistics, University Ca' Foscari Venice, Via Torino 155, 30172 Venezia-Mestre, Italy; Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cinthia ed. 7, 80126 Naples, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Libralato
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002133:Calcium Sulfate / Q000737:chemistry; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry; D011891:Rain; D012623:Seawater; D012987:Soil; D014131:Trace Elements / Q000032:analysis* / Q000737:chemistry
chemical_list: D004785:Environmental Pollutants; D019216:Metals, Heavy; D012987:Soil; D014131:Trace Elements; D000537:Aluminum Oxide; D002133:Calcium Sulfate
keywords: Dredged marine sediments; Mineral amendments; Red mud; Stabilization; Trace elements