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Mineralogical attenuation for metallic remediation in a passive system for mine...
Valente, Teresa Maria Fernandes; Antunes, M.; Braga, M. A. Sequeira; Prudêncio, M. I.; Marques, R.; Pamplona, J.Passive systems with constructed wetlands have been consistently used to treat mine water from abandoned mines. Long-term and cost-effective remediation is a crucial expectation for these water treatment facilities. To achieve that, a complex chain of physical, chemical, biological, and mineralogical mechanisms for pollutants removal must be designed to simulate natural attenuation processes. This paper aims to...
Mineralogical composition and metals retention in the fine-fraction streambed p...
Alves, Raquel Cepeda; Valente, Teresa Maria Fernandes; Braga, M. A. Sequeira; Gomes, C. LealThis work presents data from an abandoned mine (Valdarcas, NW Portugal) that, although submitted to environmental rehabilitation, stills presenting marks of AMD. Water and sediment samples from the riverine system were analyzed for chemical composition and mineralogy. Chemical contents of Fe, As and W in the < 20μm fraction indicate strong enrichment relatively to the water. Proportions of iron oxide-oxyhydroxi...
Properties of the ochre-precipitates formed during passive treatment of AMD for...
Valente, Teresa Maria Fernandes; Antunes, M.; Pamplona, J.; Grande, J. A.; De la Torre, M. L.; Santisteban, M.; Cruzado, M.This work presents the properties of the waste sludge formed by neutralization in a passive system, constructed to treat AMD from an abandoned Au-mine (Jales plant, Portugal). These wastes, here designated as ochre-precipitates, pose some management problems since they are quantitatively important and interfere with the biological treatment, affecting the global performance of the treatment plant. The geochemic...
Natural remediation of mine waste-dumps : mapping the evolution of vegetation c...
Valente, Teresa Maria Fernandes; Gomes, Patrícia; Pamplona, J.Abandoned mine waste-dumps are focus of environmental impact, especially when there are reactive minerals, such as sulfides. From their oxidation results long lasting typical impacts, especially acid mine drainage (AMD)and contamination of soil. Natural attenuation is often relevant and sometimes is enough to promote remediation. However, in the presence of abundant sulfide-rich wastes, technical intervention i...
Diagn??stico geol??gico de potencialidades e estrangulamentos no ordenamento do...
Fernandes, R.; Gomes, C. Leal; Alves, Raquel Cepeda; Valente, Teresa Maria Fernandes; Dias, Patr??cia Sofia AlvesO Vale do rio Estor??os apresenta uma diversidade geol??gica singular, materializada em v??rios fulcros de interesse geol??gico - patrimonial e potencial ou econ??mico. Antev??em-se poss??veis ??bices ?? valoriza????o destes locais o que suscita a necessidade de elabora????o de um quadro de ordenamento sustent??vel a n??vel municipal e regional capaz de evitar a sua deprecia????o e tamb??m implica a discuss??o ...
Fuzzy modelling of acid mine drainage environments using geochemical, ecologica...
Valente, Teresa Maria Fernandes; Gomes, C. LealFuzzy logic was applied to model acid mine drainage (AMD) and to obtain a classification index of the environmental impact in a contaminated riverine system. The data set used to develop this fuzzy model (a fuzzy classifier) concerns an abandoned mine in Northern Portugal— Valdarcas mining site. Here, distinctive drainage environments (spatial patterns) can be observed based on the AMD formed in the sulphide-ri...
Occurrence, properties and pollution potential of environmental minerals in aci...
Valente, Teresa Maria Fernandes; Gomes, C. LealThis paper describes the occurrences, the mineralogical assemblages and the environmental relevance of the AMD-precipitates from the abandoned mine of Valdarcas, Northern Portugal. At this mining site, these precipitates are particularly related with the chemical speciation of iron, which is in according to the abundance of mine wastes enriched in pyrrhotite and pyrite. The more relevant supergene mineralogical...
Modelos de caracterização de impacte ambiental para escombreiras reactivas : eq...
Valente, Teresa Maria FernandesOs locais de acumulação dos resíduos de actividade extractiva passada – escombreiras abandonadas – são o principal objecto de estudo. A caracterização do impacte ambiental (IA) que estas infra-estruturas desencadeiam no meio ambiente, em especial nos sistemas fluviais receptores da drenagem superficial, constituiu a principal motivação. Na unidade territorial alvo de estudo – Noroeste de Portugal – foi seleccio...
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