Browsing by Author "Silva, Eduardo Ferreira da"
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- Acid mine drainage from the Panasqueira mine and its influence on Zêzere river (Central Portugal)Publication . Candeias, Carla; Ávila, Paula Freire; Silva, Eduardo Ferreira da; Ferreira, Adelaide; Salgueiro, Ana Rita; Teixeira, João PauloThe Panasqueira hydrothermal mineralization, located in central Portugal, is the biggest Sn–W deposit of the Western Europe. The main evidences of the mining exploitation and ore treatment operations are testified with huge tailings, mainly, in the Rio and Barroca Grande areas. The mining and beneficiation processes, at the site, produces metal rich mine wastes. Oxidation of sulfides tailings and flow from open impoundments are responsible for the mobilization and migration of metals from the mine wastes into the environment. Acid mine drainage (AMD) discharged from Rio tailing has a pH around 3 and high metal concentrations. In Zêzere river, Fe and As are the most rapidly depleted downstream from AMD once As adsorbs, coprecipitate and form compounds with iron oxyhydroxides. The Zêzere river waters are oversaturated with respect to kaolinite and goethite and ferrihydrite can precipitate on stream with a near-neutral pH. At sites having low pH the dissolved Fe species in the water, mainly, occur as sulfate complexes due to a high SO4 concentration. Melanterite (Fe2+(SO4)·7(H2O)) and minor amounts of rozenite (Fe2+(SO4)·4(H2O)) and szomolnokite (Fe2+(SO4)·(H2O)) were observed on Rio tailing basement.
- Assessment of Panasqueira mine surrounding soils through a contamination factorPublication . Candeias, Carla; Salgueiro, Ana Rita; Silva, Eduardo Ferreira da; Ávila, Paula Freire
- Availability of trace elements in the abandoned Freixeda gold mine area, NE PortugalPublication . Costa, Maria do Rosário; Ávila, Paula Freire; Ferreira, Adelaide; Silva, Eduardo Ferreira da
- Avaliação do impacte da drenagem de água ácida na hidrogeoquímica do rio Zêzere : o caso de estudo da mina da Panasqueira, PortugalPublication . Ávila, Paula Freire; Ferreira, Adelaide; Salgueiro, Ana Rita; Candeias, Carla; Melo, Rita; Silva, Eduardo Ferreira daA mineralização hidrotermal da Panasqueira localiza-se no centro de Portugal e é o maior depósito de Sn-W da Europa Ocidental. A exploração mineira e as operações do tratamento do minério deram origem a escombreiras de grandes dimensões, principalmente, nas áreas do Cabeço do Pião (escombreira do Rio) e Barroca Grande. A exploração e beneficiação dos processos de tratamento no local geraram rejeitados ricos em metais. A oxidação dos sulfuretos existentes na escombreira e o escoamento pela barragem de contenção de lixiviados, são os responsáveis pela mobilização e migração dos metais a partir dos rejeitados da mina até ao meio ambiente. As descargas das drenagens de água ácida da escombreira do Rio possuem um valor baixo de pH (pH < 3) e elevadas concentrações em metais pesados. No Rio Zêzere, o Fe e o As são os elementos que apresentam o mais rápido decaimento de teores uma vez que o As é adsorvido/e ou coprecipita e forma compostos pouco solúveis com os óxidos e hidróxidos de ferro. Em locais com baixo pH as espécies de Fe dissolvidas ocorrem, principalmente, como sulfatos complexos devido à elevada concentração de SO4 2-. Melanterite (Fe2+(SO4).7(H2O)) e pequenas quantidades de rozenite (Fe2+(SO4).4(H2O)) e szomolnokite (Fe2+(SO4).(H2O)) foram observadas na base da escombreira do Rio.
- Environmental assessment of Ni and Cd in topsoil and ground-level dust from urban playgrounds, public gardens and parks from Lisbon, PortugalPublication . Reis, Amélia; Patinha, Carla; Silva, Eduardo Ferreira da; Dias, Ana; Bartolomeu, Sofia; Sousa, António; Cachada, Anabela; Batista, Maria Joao; Prazeres, Cátia; Figueira, Rui; Sergio, Cecilia; Salgueiro, Rita; Neves, Orquídea; Duarte, Armando
- Heavy metal pollution in mine-soil-plant system in S. Francisco de Assis - Panasqueira mine (Portugal)Publication . Candeias, Carla; Melo, Rita; Ávila, Paula Freire; Silva, Eduardo Ferreira da; Salgueiro, Ana Rita; Teixeira, João PauloThe active Panasqueira mine is a tin–tungsten (Sn–W) mineralization hosted by metasediments with quartz veins rich in ferberite. The economic exploitation has been focused on wolframite, cassiterite and chalcopyrite. The mineralization also comprises several sulphides, carbonates and silver sulphosalts. The mining and beneficiation processes produces arsenic-rich mine wastes laid up in huge tailings and open air impoundments that are the main source of pollution in the surrounding area, once the oxidation of sulphides can result in the mobilization and migration of trace metals/metalloids from the mining wastes into the environment, releasing contaminants into the ecosystem. A geochemical survey was undertaken, in order to investigate the environmental contamination impact on agricultural and residential soils in S. Francisco de Assis village due to the mining activities. Rhizosphere samples, vegetables (Solanum tubersum sava and Brassica olerácea L.) which constitute an important part of the local human diet), irrigation waters and road dusts were collected in private residences in S. Francisco de Assis village. According to the Ontario guidelines ( Ministry of Environment, 2011), the Arsenic contents in the rhizosphere soils exceed 20 times the reference value for agricultural soils (11 mg kg-1). The result obtained showed that some edible plants frequently used in the region could be enriched in these metals/metalloids and may represent a serious hazard if consumed. The potatoes tend to have a preferential accumulation in the leaves and roots while in cabbages most elements have a preferential accumulation in the roots. An index of the risk for residents, due to ingesting of these metals/metalloids, by consuming vegetables grown around the sampling area, was calculated and the result indicates that the inhabitants of S. Francisco de Assis village are probably exposed to some potential health risks through the intake of arsenic, cadmium and also lead via consuming their vegetables.
- Heavy metal pollution in Mine-Soil-Plant System in S. Francisco de Assis - Panasqueira mine (Portugal)Publication . Melo, Rita; Candeias, Carla; Ávila, Paula Freire; Salgueiro, Ana Rita; Ferreira, A.; Silva, Eduardo Ferreira da
- Identifying sources and assessing potential risk of exposure to heavy metals and hazardous materials in mining areas : the case study of Panasqueira Mine (Central Portugal) as an examplePublication . Candeias, Carla; Silva, Eduardo Ferreira da; Ávila, Paula Freire; Teixeira, João PauloThe Sn-W Panasqueira mine, in activity since the mid-1890s, is one of the most important economic deposits in the world. Arsenopyrite is the main mineral present as well as rejected waste sulphide. The long history is testified by the presence of a huge amount of tailings, which release considerable quantities of heavy metal(loid)s into the environment. This work assesses soil contamination and evaluates the ecological and human health risks due to exposure to hazardous materials. The metal assemblage identified in soil (Ag-As-Bi-Cd-Cu-W-Zn; potentially toxic elements (PTEs)) reflects the influence of the tailings, due to several agents including aerial dispersion. PTEs and pH display a positive correlation confirming that heavy metal mobility is directly related to pH and, therefore, affects their availability. The estimated contamination factor classified 92.6% of soil samples as moderately to ultra-highly polluted. The spatial distribution of the potential ecological risk index classified the topsoil as being of a very high ecological risk, consistent with wind direction. Non-carcinogenic hazard of topsoil, for children (1–6 years), showed that for As the non-carcinogenic hazard represents a high health risk. The carcinogenic risks, both for children and adult alike, reveal a very high cancer risk mostly due to As ingestion.
- Impact of mining activity in Panasqueira (Central Portugal) : environmental and occupational exposure to heavy metalsPublication . Candeias, Carla; Coelho, Patrícia; Silva, Eduardo Ferreira da; Salgueiro, Rita; Ávila, Paula Freire; Teixeira, João Paulo
- Introducing "UrbanEnviron@Lisbon 2008" a GIS-platform for environmental and human health data managementPublication . Patinha, Carla; Reis, Amélia; Silva, Eduardo Ferreira da; Dias, Ana; Bartolomeu, Sofia; Sousa, António; Cachada, Anabela; Batista, Maria Joao; Prazeres, Cátia; Rocha, Fernando; Costa, Cristiana; Sequeira, Cristina; Terroso, Denise; Figueira, Rui; Sérgio, Cecília; Salgueiro, Rita; Neves, Orquídea; Duarte, Armando