title: Modification, adsorption, and geochemistry processes on altered minerals and amorphous phases on the nanometer scale: examples from copper mining refuse, Touro, Spain.
abstract: The sulfide oxidation and precipitation of Al-Fe-secondary minerals associated with abandoned acid mine drainage (AMD) from the abandoned copper mine waste pile at Touro, Spain, has been studied by sequential extraction (SE) combined with several techniques with the intent of understanding the role of these processes play in the natural attenuation of hazardous element contaminants in the AMD. In addition, the fragile nature of nanominerals and ultrafine particle (UFP) assemblages from contaminated sediment systems from the abandoned copper mine required novel techniques and experimental approaches. The investigation of the geochemistry of complex nanominerals and UFP assemblages was a prerequisite to accurately assess the environmental and human health risks of contaminants and cost-effective chemical and biogeological remediation strategies. Particular emphasis was placed on the study and characterization of the complex mixed nanominerals and UFP containing potentially toxic elements. Nanometer-sized phases in sediments were characterized using energy-dispersive X-ray spectrometer (EDS), field-emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM) images. The identification of the geochemical and mineralogical composition of AMD in Touro, as well as the different formation mechanisms proposed, complement the existing literature on secondary mineral assemblages and provide new emphasis to increase the understanding of extreme environments. The results also demonstrated that variations in the geochemical fractionation of hazardous elements in AMD were more influenced by the secondary mineral proportion and by AMD pH.
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil.
authors.forename: Matheus
authors.initials: M
authors.lastname: Civeira
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil.|Department of Soil Science, University of Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Marcos L S
authors.initials: ML
authors.lastname: Oliveira
authors.affiliation: University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY, 40511, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Hower
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil.
authors.forename: Dayana M
authors.initials: DM
authors.lastname: Agudelo-Castañeda
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil.
authors.forename: Silvio R
authors.initials: SR
authors.lastname: Taffarel
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil.
authors.forename: Claudete G
authors.initials: CG
authors.lastname: Ramos
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil.
authors.forename: Rubens M
authors.initials: RM
authors.lastname: Kautzmann
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil. felipeqma@hotmail.com.
authors.forename: Luis F O
authors.initials: LF
authors.lastname: Silva
mesh_terms: D000327:Adsorption; D011232:Chemical Precipitation; D003300:Copper / Q000032:analysis* / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods*; D015386:Hazardous Substances / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D019216:Metals, Heavy / Q000032:analysis / Q000737:chemistry; D008903:Minerals / Q000032:analysis* / Q000737:chemistry; D008906:Mining; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D013030:Spain
chemical_list: D015386:Hazardous Substances; D019216:Metals, Heavy; D008903:Minerals; D012989:Soil Pollutants; D003300:Copper
keywords: Abandoned copper mine; Acid sulfate; Environment; Precipitates