Percorrer por autor "Silva, N."
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- Avaliação do nível de contaminação nos sedimentos de cursos de água do Sistema Mineiro de Caveira (Grândola)Publication . Silva, R. da; Fonseca1, R.; Araújo, J. F.; Silva, N.; Albuquerque, M.T.D.O presente trabalho, inserido no Projeto GeoMatRe, visa o levantamento das condições mais atualizadas no que toca aos parâmetros físico-químicos numa mina de drenagem ácida. Uma situação crítica que ocorre na área mineira de Caveira, em Grândola, Portugal, abandonada desde a década de 60 do século passado. O objetivo passa por analisar as condições de contaminação de Elementos Potencialmente Tóxicos (EPT) nos sedimentos que ocorrem quer em fases móveis e dissolvidas na água intersticial dos sedimentos, quer em fases mais imóveis. Neste trabalho é realizada uma caracterização geral da área do sistema mineiro, verificando-se um nível de contaminação da área, através da análise do Índice de Geoacumulação (IGEO) e do Fator de Enriquecimento (FE), onde os elementos Cu, Pb, Zn, As e Hg demonstram ser os principais EPT’s na região, apresentando valores, em alguns dos casos, milhares de vezes acima dos estipulados pelas normas nacionais.
- Influence of tailings from a sulfide mine on drainage water quality, 60 years after its abandonment. A case study in SW PortugalPublication . Araújo, J.F.; Albuquerque, M.T.D.; Silva, N.; Silva, R. daThe GeoMatRe project aims to find low-cost solutions for water and sediment rehabilitation using raw geomaterials, in abandoned mines of the Iberian Pyritic Belt. One of our case studies is the Caveira mine in southwestern Portugal, where large piles of mining waste, containing significant amounts of metals, record the long history of its exploitation for gold (Au) and silver (Ag). After the exhaustion of its reserves, the extraction of the remaining metals (cooper (Cu), lead (Pb) and zinc (Zn)) and sulphur (S) continued, until its abandonment during the 60s of 20th century. This work has two objectives: (i) to study the influence of mine and mine tailings drainage on water quality by analysing the dissolved and particulate material in drainage waters, and (ii) to determine whether there are differences in the contamination level of these waters according to the different weather conditions of the last two winters.
- Influência dos rejeitos de uma mina de sulfuretos na qualidade da água de drenagem, 60 anos após o seu abandono: Caso de estudo no SW de PortugalPublication . Araújo, J.; Fonseca, R.; Albuquerque, Maria Teresa; Silva, N.; Silva, R.The GeoMatRe project aims to find low-cost solutions for water and sediment rehabilitation using raw geomaterials, in abandoned mines of the Iberian Pyritic Belt. One of our case studies is the Caveira mine in southwestern Portugal, where large piles of mining waste, containing significant amounts of metals, record the long history of its exploitation for Au and Ag. After the exhaustion of its reserves, the extraction of the remaining metals (Cu, Pb, Zn) and S continued, until its abandonment during the 60s of XX century. This work has two objectives: (i) to study the influence of mine and mine tailings drainage on water quality by analyzing the dissolved and particulate material in drainage waters, and (ii) to determine whether there are differences in these waters according to the different climatic conditions of the last two winters. Therefore, we will conduct a new sampling campaign, which will allow us to make a comparative study.
- Observação do nível de contaminação nos sedimentos de cursos de água do Sistema Mineiro de Caveira (Grândola)Publication . Fonseca, R.; Araújo, J.; Silva, N.; Albuquerque, Maria TeresaFollowing the present work inserted in the GeoMatRe Project, an ongoing project funded by Fundação La Caixa, the conditions of the most updated physical and chemical parameters of an Acid Mine Drainage are analysed, a critical situation which occurs in the mining area of Caveira (Grândola, Portugal), abandoned since the 60’s. It is intended, within the scope of the project, to observe the conditions of contamination by Potentially Toxic Elements in the sediments, both dissolved and suspended forms in the water column, in order to carry out a general characterization of the mining system, based on the nature and amounts of the contaminating elements, as well as the conditions of acidification occurring on sediments present in the environment that surrounds the mining area. The aim is to understand, based on the existing conditions, the best environmental remediation technology to be applied in the region.