Avaliação da concentração de radão nas águas minerais naturais nos estabelecimentos termais Portugueses

s águas minerais naturais usadas em tratamentos terapêuticos nos estabelecimentos termais apresentam composições químicas diversificadas, contendo por vezes quantidades significativas de radionuclídeos naturais, como é o caso do radão. O objetivo deste estudo foi avaliar a concentração de radão das águas minerais naturais nas captações (furo e nascente) e nos locais de tratamento (buvete, emanatório, técnicas de inaloterapia-ORL, piscina termal e duche vichy) de 17 estabelecimentos termais Portugueses, tendo como principal foco a exposição ocupacional. Foram realizadas 54 colheitas de água mineral natural nas captações e nos locais de tratamento destes estabelecimentos termais. Os resultados obtidos para a concentração de radão na água variam entre 0.1 e 6949 Bq/L, com uma média geométrica de 175 Bq/L e média aritmética de 842 Bq/L. Verificou-se que 50 % dos resultados obtidos para a concentração de radão na água mineral natural são superiores ao nível de referência preconizado pela UE (100 Bq/L), enquanto 20 % dos resultados excederam o limite de ação (1000 Bq/L). Por outro lado, 26% dos resultados ultrapassam o valor paramétrico previstono DL 23/2016 (500 Bq/L). Em alguns casos, os elevados valores obtidos na água mineral natural são preocupantes, podendo implicar elevadas concentrações de radão no ar interior e consequentemente a exposição ocupacional ao radão.The natural mineral waters used in therapeutic treatments in thermal establishments have diverse chemical compositions, sometimes containing significant amounts of natural radionuclides, such as radon. The objective of this study was to evaluate the radon concentration of natural mineral waters in the holeand spring, and in the treatment sites (buvette, emanatory, inhalation-ORL techniques, thermal pool and vichy shower) of 17 Portuguese thermal establishments focusing on occupational exposure. Fifty-four samples of natural mineral water were collectedin the abstractions and treatment sites of these thermal establishments. The results obtained for the radon concentration in water vary between 0.1and 6949 Bq/L, with a geometric mean of 175 Bq/L and arithmetic mean of 842 Bq/L. It was found that 50% of the results obtained for the radon concentration in the natural mineral water were higher than the reference level recommended by the EU (100 Bq/L), while 20% of the results exceeded the action limit (1000 Bq/L) . On the other hand, 26% of the results exceed the parametric value provided in Decree-Law 23/2016 (500Bq/L). In some cases, the high values obtained in natural mineral water are worrisome and may involve high concentrations of radon in indoor air and consequently occupational exposure to rado

A Holistic Approach in Re-mining Old Tailings Deposits for the Supply of Critical-Metals: A Portuguese Case Study

Demand growth for metallic minerals has been faced with the need for new techniques and improving technologies for all mining life-cycle operations. Nowadays, the exploitation of old tailings and mine-waste facilities could be a solution to this demand, with economic and environmental advantages. The Panasqueira Mine has been operating for more than a century, extracting tungsten and tin ore. Its first processing plant, "Rio", was located near the Zerere river, where mineral-processing residues were deposited on the top hillside on the margin of this river in the Cabeco do PiAo tailings dam. The lack of maintenance and monitoring of this enormous structure in the last twenty years represents a high risk to the environment and the population of the surrounding region. A field-sample campaign allowed the collection of data, and resulted from laboratory tests to use regression optimization. Re-mining the tailings by hydrometallurgical methods was considered to satisfy the two conditions of metal demand and environmental risk. The metal content in Cabeco do PiAo was shown be enough for environmental restoration. The re-mining solution was studied, taking into account the technical, economic, social, and environmental aspects

Characterization of a mine legacy site: an approach for environmental management and metals recovery

The characterization of historical mine tailings provides important information for land-management decisions, in particular when considering potential reprocessing activities or the development of an environmental protection program. In addition, outcomes from such characterization may define the scope for a more detailed investigation. The present work describes the characterization of the waste material from the Cabeco do Piao tailings impoundment performed within the project ReMinE: Improve Resource Efficiency and Minimize Environmental Footprint. The purpose of the work was to investigate alternative mine waste management options such as the extraction of valuable resources from an environmental liability. The study involved the collection of 41 samples at different locations at two different depths, physical and chemical characterization of the wastes, natural leaching tests, and potential for acid generation. The results showed that, apart from the potential instability of the dyke (with an average slope of 35 degrees), the drained solutions flowing by percolation contain very small particles with high arsenic contents that are being incorporated into the river sediments. In addition, these very fine-grained materials are available for the transport by the wind creating secondary sources of environmental contamination. This data is fundamental for economic and environmental assessment of the two main alternatives, reprocessing or removal

Spatial Variability of Atmosphere Dust Fallout Flux in Urban–Industrial Environments

This work aimed to assess and characterize the air quality in what concerns particulate pollution in urban–industrial environments. The main objectives were to study the spatial variability of the deposition flux of particulate pollution identifying areas with higher deposition and to associate the variability with climatological variables and with possible surrounding emitting sources. The method for collecting the deposited particles was based on the standard NF X 43–007. Sampling for particulate pollution took place between April 2015 and February 2016 through seven sampling campaigns. Maps of the spatial dispersion for the particulate pollution were obtained through statistics and geostatistics techniques. Elemental identification by scanning electron microscopy (SEM) was also used but only in two sampling campaigns. The results show that the sampling campaigns that took place during hot and dry periods, 2nd and 3rd, present higher deposition flux: 2.04 g/(m2 × month) and 1.72 g/(m2 × month), respectively. Lower deposition fluxes were registered in the 6th and 7th campaigns: 0.23 g/(m2 × month) and 0.24 g/(m2 × month), respectively. A recurrent high deposition was also observed at specific sampling points that may be due to both the nearby road traffic and the presence of chimneys. SEM analysis allowed to associate repetitive element deposition, at the same sampling point, to the same emitting source

Mitigation of Uranium Mining Impacts - a Review on Ground-water Remediation Technologies

Groundwater contamination is one of the most concerning issues from uranium mining activities. Radionuclides cannot be destroyed or degraded, unlike some organic contaminants (and similar to metals). Besides, sites, where radionuclides may be found, are mainly radioactive and mixed waste disposal areas, and therefore many other contaminants may also be present in groundwater. The state-of-the-art of environmental technology is continually changing, and thus a review on technologies application is of utmost relevance. This work gives an overview of the available remediation technologies for groundwater contaminated with radionuclides resulting mainly from uranium mining. For each technology, a theoretical background is provided; the state of development, limitations, efficiency, and potential adverse effects are also approached. Examples of application and performance monitoring of remediation progress are described, and criteria for the selection of the appropriate remediation technology are given. The most effective remediation technology will always be site-specific as a result of the multitude of geographic and operational factors that influence the effluent quality and impact the technical feasibility of treatment methods. Ion exchange, chemical precipitation, and membrane filtration have been considered by the U.S. Environmental Protection Agency (US EPA) as best demonstrated available technologies for radium and uranium removal. Several factors have been demonstrated to influence the selection of a remediation technology (technological aspects and non-technical factors), but even for the technologies demonstrated or industrial proven, two important challenges remain; the (still) mobile radionuclides and the generation of secondary wastes. Besides, remediation technologies are constantly evolving, but future advancement depends on rigorously monitored, documented efficiency, and results achieved. Therefore, the technologies approached in this paper are by no means exhaustive

Análise qualitativa e quantitativa de uma instaltalação de produção de inertes

Estágio financiado por: PRODEP II, Medida 5/Acção 5.2 - EstágiosRelatório do estágio curricular da LEMI 1996/199

Modelo integrado para a avaliação de exposição ambiental a resíduos mineiros radioactivos

Dissertação apresentada para obtenção do grau de Mestre em Engenharia do Ambiente, ramo Gestão e Tratamento de Resíduos Industriais, sob a orientação do Prof. Doutor António Fiúz