ESTCB - Comunicações em encontros científicos e técnicos
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- Compositional signature of trace elements in stream sediments along the Babahoyo/Daule riverbeds (Ecuador): A geostatistical and Bayesian approachPublication . Cabrera, Marlon; Pazo, Maria; Gerassis Davite, Saki; Albuquerque, M.T.D.; Sierra, C.; Boente, CarlosThe high concentration of potencially toxic elements (PTEs) in stream sediments may pose a significant threat since the pollutants may travel long distances to the sea, affecting aquatic environments and public health. When rivers cross large cities, minning, or cultivated areas, it is usually observing an increasing concentration of PTEs downstream, reachiong hazardeous levels due to the ability and persistence oh heavy metals by bioaccumulation in the enviromnent.
- Contribuição de modelos estocásticos no estudo da contaminação de antigas explorações mineirasPublication . Góis, Joaquim; Carvalho, Paulo; Isabel Margarida Horta Ribeiro Antunes; Albuquerque, M.T.D.O presente trabalho consiste no estudo sobre eventuais contaminações provocadas pela atividade mineira da uma antiga mina de Sn-W na zona centro de Portugal. Em toda área envolvente da antiga exploração, foram recolhidas amostras de sedimentos de corrente. A análise destas amostras permitiu determinar valores de concentração para vários elementos químicos. Com base no método IGeo e nos critérios de Muller (Antunes et al., 2018), foram estabelecidos um conjunto de índices e níveis de contaminação. Posteriormente, com o recurso a metodologias no âmbito da estatística multivariada e da geoestatística, construíram-se representações cartográficas e quantificou-se a variabilidade espacial dos diferentes elementos químicos suscetíveis de contaminar importantes cursos de água com consequentes implicações para a saúde humana (Antunes et al., 2016).
- The geochemical behavior of Pb and Zn in waters and stream sediments around a former Pb-Zn mine, central PortugalPublication . Carvalho, Paula; Antunes, I.M.H.R.; Albuquerque, M.T.D.; Santos, AntónioIn Portugal, ore mineral exploitation has left millions of tons of mining waste rich in metals in the environment. The former Várzea Pb-Zn mine is located in the Várzea dos Cavaleiros village, about 10 km from Sertã village and 65 km from Castelo Branco county, central Portugal. The Pb-Zn quartz vein with N10ºW; 75º SW orientation, 0.5-1.5 m thick, intruded the Neoproterozoic-Cambrian schist-greywacke complex. About 17576.47 tons of ore minerals were exploited between 1953 and 1967 [1]. There are two main mine dumps, the largest one is 100 m long and 47 m wide. The other dump is mainly composed of fine tailings.
- A geostatistical approach for mercury spatial patterns assessment in sediments in an old mining region: The Caveira Mine case study, PortugalPublication . Mota, Natália; Fonseca, Rita; Araújo, Joana; Isabel Margarida Horta Ribeiro Antunes; Valente, Teresa; Barroso, Ana; Araújo, Alexandre; Albuquerque, M.T.D.; Zanini , Andrea; D'Oria, MarcoMercury pollution is significant in many former mining communities worldwide, including in developing countries. Anthropic contributions to environmental Hg pollution are mostly connected to fuel fossil emissions, industrial and mining activities. Among mining operations, gold exploration contributes to the highest Hg contamination rates, given the processes, widely used in the past, of mixing Hg with the gold containing ore, to separate this metal from the bulk impurities. This study, as part of the GeoMaTre project, an ongoing collaborative network (2021-2024) between the Polytechnic Institute of Castelo Branco and the University of Évora, Portugal, aimed to evaluate the potential risk of mercury pollution in stream sediments in the Caveira area, an abandoned Cu, Pb, Zn, Ag, and Au mine, included in the Iberian Pyrite Belt, at South Portugal. This mine corresponds to a Gossan developed on pyrite mineralization, with high gold and silver content at the official beginning of its exploitation, in 1863, having exhausted the reserves in these precious metals in the 1920s. Until the date of its abandonment (1966) the exploitation focused on the remaining metals (Cu, Pb, Zn) and S. Currently, the surrounding area of Caveira mine is essentially composed of areas of waste accumulation, from mining activity, with little or no vegetation. Thirty-three sediment samples were collected from within 0 to 10 cm depth, in a grid of 1Km x 1Km. Hg was determined in samples preserved at about 4ºC at the time of collection, through a mercury analyzer (NIC MA 3000) based on thermal decomposition, gold amalgamation, and cold vapor atomic absorption spectroscopy detection.
- Green brick – an alternative for the construction industryPublication . Calmeiro dos Santos, Cristina; Albuquerque, M.T.D.; Ribeiro Mendes Cabrito, Arlindo José; Oliveira, BrunoThe sustainable development in the building sector, needs to integrate environmentally sustainable solutions. In the herein research work a new sustainable green-brick, using cellulosis waste, is introduced aiming at the sustainable development in the construction industry. The use of waste contributes to the reduction of landfills with the consequent availability of suitable areas for reafforestation and the production of low cost raw materials with energy consumption reduction, and diminuishing the carbon footprint. The purpose was to characterize a cement brick composed of cement, sand, dregs (in two different proportions), and water. In the current world’s food crisis, the need to preserve healthy and fertile soils is one of the needs of today’s societies and a key point for the EU Green Deal in what is the Road map for the sustainability of the European Union. Promoting resource use efficiency through the adoption of a circular and clean economy in climate change scenarios, reversing biodiversity losses, and controlling pollution, in soils, water, and the atmosphere, are critical for the future of our planet. The present project is at Technologic Readiness level (TRL) 7 and Business Readiness Level (BRL) 4. It is anticipated that TRL 9 will be achieved within one year – and within two years to BRL 7.
- 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, M.T.D.; 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.
- Investigating contamination indexes and mobility processes in mine-stream sediments systems (Central Portugal)Publication . antunes, Isabel Margarida; Carvalho, Paula; Albuquerque, M.T.D.; Santos, AntónioThe mining industry plays a crucial role in today’s society due to the growing demand for strategic materials. Nevertheless, it is essential to acknowledge the signi cant threats posed to the environment by mining operations. Striking a delicate balance between resource needs and environmental protection is imperative.
- Mobility of uranium in groundwater-surface water systems in a post-mining context (Central Portugal)Publication . Antunes, I.M.H.R.; Carvalho, Paula; Albuquerque, M.T.D.; Santos, A.C.T.In uranium abandoned mine areas, particularly with mine tailings and open-pit lakes, the mobility of potentially toxic elements still acts as a source of surface and groundwater contamination. e water of open-pit lakes from Ribeira de Bôco mine and associated groundwater and surface water from the area is neutral and with low metal contents. However, some water samples are contaminated with Cd, Cr, Cu, Fe, Mn, As, and U and should not be used for human consumption or in agricultural activities. e baseline uranium threshold is considerably high for groundwater, which is supported by geogenic features and mining activities.
- 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, M.T.D.Following 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.
- Relations between river sediments and dissolved matterPublication . Egozcue, Juan José; Pawlowsky-Glahn, Vera; Fonseca, Rita; Albuquerque, M.T.D.A typical but actually unsolved problem is relating dissolved ions in water and the chemical composition of the corresponding sediments. Our first assumption is that botH ion concentrations and the sediments are compositional in nature. Data from the 2022 and 2023 campaigns in the Trimpancho river (Mining System) (Huelva, Spain) are used to illustrate the possibilities and the challenges of such an analysis. The data consists of 23 sampling points recording both 14 dissolved ions (mg/L) and 10 elements (mg/kg) from the sediment. A first analysis of association using the proportionality index of parts (PIP) reveals that binary relations are weak, while the Aitchison-distance correlation indicates that there is some moderate correlation between dissolved ions and sediments. The relation was also examined using compositional canonical correlation. A surprising result was that up to three canonical functions exhibited very high correlations. A deeper evaluation suggested that these high correlations are due to overparametrization given the small sample size. Finally, after simplification of the canonical correlation model, some balances within dissolved ions and within sediments evidenced moderate correlations in accordance with the previous results. Results show that the main relations involve several elements and single element relations are irrelevant. For instance, the ion balance of Ca, Cu, Fe, Zn over Mg, Mn, Ni has a 0.7 Pearson correlation with the sediment balance Al, Mn over Cr.