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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Nature's women: ecofeminist reflections on Jabiluka

Nugent, Monica, School of Science & Technology Studies, UNSW January 2002 (has links)
Environmentalists see the protest against the Jabiluka uranium mine in Australia's Northern Territory as an example of positive green-black relations. The formation of an alliance between Aboriginal owners and greens to protest against the mine resulted in a lengthy campaign that included maintaining a camp near the leasesite and organising a long series of mass protest actions in a remote location over an extended period from March to October 1998. However, some tensions between greens and the traditional Aboriginal owners became evident as the campaign went on. This thesis traces the origins of these tensions to past conflicts between environmentalists and Aboriginal people and shows that they are largely related to their conflicting perceptions of the environment. Those perceptions arise from different knowledge systems and are encapsulated in the terms 'wilderness' and 'country', used to describe the physical world by environmentalists and Aboriginal owners respectively. I discuss the attitudes towards the environment that accompany those perceptions and consider the way they were manifest in some of the tensions that arose at Jabiluka. The close relationship between influential strands of environmentalism and Western science is a related source of conflict. My analysis of that relationship shows that environmentalism, via 'green science' is more closely aligned with the developmentalist worldview than the Aboriginal worldview. The thesis is an analytical reflection upon the Jabiluka Protesters' Camp based on the personal experience I gained from my fieldwork there and informed by the literature of feminism, ecofeminism, social constructionism and anthropology. I discuss the manifestations of ecofeminism I observed at Jabiluka. I argue that the Jabiluka Protesters' Camp functioned successfully because it utilised ecofeminist principles and practices, that as a consequence the relationship between greens and blacks has been strengthened and therefore that ecofeminism can continue to have a positive effect on those relations in the future.
12

Välja för framtid om markanvändningsval och förtroendemannainflytande i kommunal planering /

Castensson, Reinhold. January 1980 (has links)
Thèse Philos., Lund, 1980. / Résumé en anglais. Added t.p. with thesis statement inserted.
13

Avaliacao da contaminacao radiologica de um solo agricola nas proximidades de uma mina de uranio

SZELES, MARLENE S.M.F. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:38:42Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:21Z (GMT). No. of bitstreams: 1 05825.pdf: 11314587 bytes, checksum: 4c78dd49091b4bfc57c3ff1ed797e9e9 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
14

Implantação de técnica para determinação de parâmetros hidráulicos e de transporte de solutos em solos visando a aplicação em simulação computacional de migração de contaminantes / Implementation of a technique for hydraulic and solute transport parameters determination aiming the application in computational simulation of contaminants migration

Silva, Daniela Villa Flor Montes Rey 16 August 2018 (has links)
Orientador: Marcio Luiz de Souza-Santos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-16T10:15:10Z (GMT). No. of bitstreams: 1 Silva_DanielaVillaFlorMontesRey_D.pdf: 4784626 bytes, checksum: 2c07a9198d76af68b1571651aa00046a (MD5) Previous issue date: 2010 / Resumo: Este trabalho tem por objetivo a implantação de uma técnica para estimativa simultânea dos parâmetros hidráulicos e de transporte de solutos em solos, visando a aplicação em simulação computacional de migração de contaminantes. Foi selecionado um aparato experimental para a realização do experimento de transporte de soluto em colunas, assim como o código Hydrus-1D para estimativa de parâmetros através da Técnica de Levenberg-Marquard. Para testar o método foi utilizado um solo arenoso não-reativo. Com esse material foram estimados o conteúdo de água de saturação qs, a condutividade hidráulica de saturação Ks e o coeficiente de dispersão D. Foram testadas quatro estratégias para a estimativa onde os parâmetros foram estimados simultaneamente e separadamente em ordens diversas. As estratégias que fazem a estimativa dos parâmetros separadamente apresentaram melhores resultados. Foi avaliada também a influência das dimensões das colunas nos resultados experimentais e nos resultados das estimativas, demonstrando que colunas de menor comprimento apresentam resultados melhores e que houve uma variação nos resultados devido à variação no diâmetro, o que está em desacordo com o modelo unidimensional utilizado. Em seguida amostras de solo da mina de urânio de Caldas foram testadas. Para este material foram estimados os mesmos parâmetros anteriores mais o coeficiente de distribuição Kd. Os valores estimados para os parâmetros com o solo da mina de urânio apresentaram pequenos desvios-padrão, caracterizando boas estimativas / Abstract: The objective of this work is to implement a technique for the simultaneous estimation of hydraulic and transport parameters of soils, aiming at the application on computational simulation of contaminant migration. An adequate experimental apparatus was selected for the solute transporte experiment in small columns. The software Hydrus-1D was selected as the simulation software capable of estimating the parameters through the Levenberg-Marquardt Technique. For the implementation of the methodology a non-reactive sandy soil was used. The saturation water content qs, the saturation hydraulic conductivity Ks and the dispersion coefficient D were estimated for this material. Four approaches were tested, including simultaneous and sequential estimations in various orders. The sequential estimation resulted in better results. The influence of the dimensions of the columns on the experimental and estimation results was also evaluated, demonstrating that columns with smaller high results in better estimations and that the diameter variations resulted in variation of the behavior, in disagreement with the unidimensional model used. Next, soil samples extracted from de Caldas uranium mine were used for the estimation of the same parameters together with the distribution coefficient Kd. Values for the estimated parameters with the soil samples from the uranium mine showed small standard deviations, characterizing good estimations / Doutorado / Termica e Fluidos / Doutor em Engenharia Mecânica
15

Avaliacao da contaminacao radiologica de um solo agricola nas proximidades de uma mina de uranio

SZELES, MARLENE S.M.F. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:38:42Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:21Z (GMT). No. of bitstreams: 1 05825.pdf: 11314587 bytes, checksum: 4c78dd49091b4bfc57c3ff1ed797e9e9 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
16

Estimativa simultânea de parâmetros hidráulicos e de transporte em estéreis de mineração de urânio / Simultaneous estimation of hydraulic and transport parameters inwaste rock from uranium mining

Oliveira, Alexandre Pereira de 16 August 2018 (has links)
Orientador: Marcio Luiz de Souza-Santos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-16T12:44:27Z (GMT). No. of bitstreams: 1 Oliveira_AlexandrePereirade_D.pdf: 5076022 bytes, checksum: 0be1cd3a8682d6b21786e0251b3086f7 (MD5) Previous issue date: 2010 / Resumo: Este trabalho tem por objetivo a estimativa simultânea dos parâmetros hidráulicos e de transporte relacionados ao material existente em uma das pilhas de estéreis de mineração de urânio (Pilha de Estéreis 4) da Unidade Caldas das Indústrias Nucleares do Brasil (INB Caldas). Antes de realizar as estimativas, foi necessário conhecer as espécies químicas que são solubilizadas desse material pela ação das intempéries climáticas, sabendo-se que este material é rico em pirita (sulfeto de ferro, FeS2). Para isso foi montado um aparato experimental chamado de Experimento de Drenagem Ácida, no qual o processo de oxidação da pirita foi acompanhado em ambiente controlado. Foram feitas as determinações das concentrações de diversos elementos químicos estáveis e radioativos tanto no líquido ao longo dos testes, quanto no material sólido antes e depois dos testes. Foram calculadas a massa (ou atividade) total solubilizada, a taxa de solubilização e o percentual de solubilização. Os resultados mostraram quais espécies são mais facilmente solubilizadas e quais devem ser acompanhadas nos estudos de contaminação. As estimativas dos parâmetros hidráulicos e de transporte foram obtidas através da associação de um Experimento de Transporte de Solutos ao código computacional Hydrus-1D. Além da solução numérica do modelo adequado ao experimento, este código possui implementada a Técnica de Levenberg-Marquardt para estimativa de parâmetros. Foram estimados o conteúdo de água de saturação qs, a condutividade hidráulica de saturação Ks e o coeficiente de dispersão D. Os resultados mostraram que o parâmetro D é mais bem estimado, seguido por qs e Ks / Abstract: The present work aims to simultaneously estimate the hydraulic and transport parameters related to the material of one of the waste rock piles (Waste Rock Pile 4) from the Poços de Caldas uranium mining and milling facility. Before performing the estimation, it was necessary to study the chemical species that are dissolved from this material by the climate action, knowing a priori that the material is rich in pyrite (iron sulfide, FeS2). In order to follow the pyrite oxidation process within a controlled environment, an experimental apparatus called Acid Drainage Experiment was assembled. During tests, concentrations of various stable and radioactive chemical elements were determined in the liquid as well in the solid material before and after the tests. In addition, the total mass (or activity) dissolved, the rate of dissolution and the percentage of dissolution were calculated. Results showed which species are more easily dissolved and those that should be followed in contamination studies. The simultaneous estimation of the hydraulic and transport parameters was accomplished through the so called Solute Transport Experiment combined with the software Hydrus-1D. This software provides the numerical solution of an adequate model, using the Levenberg-Marquardt Technique for parameter estimation. The saturation water content qs, the saturation hydraulic conductivity Ks and the dispersion coefficient D were estimated. Results showed that the parameter D was well estimated, followed by qs and Ks / Doutorado / Termica e Fluidos / Doutor em Engenharia Mecânica
17

Depósito Metamórfico-Hidrotermal de U-ETR Mary Kathleen, Noroeste de Queensland, Austrália = uma investigação baseada em assinaturas hiperespectrais e aeroradiométricas / New insights on the Mary Kathleen Metamorphic-Hydrothermal U-REE Deposit, Northwest Queensland, Austratlia : an approach based on hyperspectral and airbone gamma-ray signatures

Salles, Rodrigo dos Reis 16 August 2018 (has links)
Orientadores: Carlos Roberto de Souza Filho, Thomas John Cudahy / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-16T19:08:54Z (GMT). No. of bitstreams: 1 Salles_RodrigodosReis_M.pdf: 29354186 bytes, checksum: cd94ec7b06a8ec3077ab99b2519adafe (MD5) Previous issue date: 2010 / Resumo: O depósito metamórfico-hidrotermal de U-ETR Mary Kathleen, localiza-se à NW de Queensland, Austrália e está inserido na Província Metamórfica Mount Isa. Os litotipos predominantes nessa região compreendem rochas sedimentares (calcários, folhelhos e etc.), rochas vulcânicas (riolitos, basaltos, dacitos e etc.) e, subordinadamente, rochas granitóides (granodiorito, leucogranito porfirítico e etc.), metamorfisadas entre as fácies xisto-verde à anfibolito. O depósito Mary Kathleen (1550 Ma), atualmente exaurido, ocorre associado a skarns enriquecidos em U-ETR. A área de estudo contém ainda várias ocorrências de U com expressivas concentrações, além dos prospectos uraníferos Rita e Elaine Dorothy. Esta tipologia de depósito distingue-se dos principais depósitos mundiais de U pela ocorrência de alterações do tipo cálcio-silicática, granatização e metassomatismo de contato. Para tanto, foram necessárias condições físico-químicas especiais impostas pela instalação de intrusões graníticas de composição intermediária e ácida sobre calcário impuro, exatamente o caso da Mina Mary Kathleen. No presente estudo, são investigadas as assinaturas radiométricas regionais e as assinaturas hiperespectrais associadas aos minerais vetores da mineralização uranífera. No primeiro capítulo, dois métodos e técnicas de manipulação e integração de dados são comparados, com o objetivo de compilar mapas preditivos visando proporcionar subsídios adicionais à prospecção uranífera regional. Os mapas compilados pela abordagem Geoestatística foram fundamentados na análise das variáveis quanto a sua posição e variabilidade. O método baseado em Lógica Fuzzy reuniu mapas auto-explicativos ainda não experimentados na pesquisa mineral para a commodity U. Nesta conjuntura, áreas com alto potencial prospectivo foram evidenciadas a partir da integração dos dados aeroradiométricos. No segundo capítulo, imagens adquiridas pelo sensor hiperespectral HyMap foram processadas segundo um conjunto de métodos para extração de informações mineralógicas de detalhe. O principal resultado deste estudo foi a determinação das assinaturas hiperespectrais dos minerais satélites da Mina Mary Kathleen. Parte desta associação mineral consiste de minerais passíveis de detecção remota como a andradita, o epidoto, a hornblenda, a calcita e a escapolita. A análise espectral revelou ainda outros minerais tais como, goethita, caulinita e montmorillonita nas proximidades e frente de lavra da mina. Os cartogramas de abundância mineral, resultantes dos métodos de classificação hiperespectral Spectral Angle Mapper (SAM) e Mixture Tuned Matched Filtering (MTMF) foram combinados no espaço de cores RGB. Esta estratégia permitiu delinear áreas de domínio e mistura de minerais com grande aplicabilidade na pesquisa mineral uranífera / Abstract: The Mary Kathleen Metamorphic-Hydrothermal U-REE Deposit of northwest Queensland, Australia is inserted in the Mount Isa Metamorphic Province. The predominant rock types in the study area are represented by sedimentary rocks (limestone, shales, etc.), volcanics rocks (rhyolite, basalt, dacite, etc.) and subordinate intrusive rocks (granodiorite, porphyritic leucogranito, etc.) metamorphosed in green schist to amphibolites facies conditions. This Mary Kathleen deposit (1550 Ma), now depleted, is associated with skarns enriched in U-REE. Nevertheless, there are U occurrences with significant concentrations; also there are two prospectus uraniferous, Rita and Elaine Dorothy. This deposit type differs from the major world U deposits because of the paragenesis calc-silicates, garnetization phase and contact metasomatism. Thus, it is necessary physicochemical conditions imposed by granitic intrusions of intermediate and acid compositions upon impure limestone, as the case of Mary Kathleen Mine. In this study, we investigate the regional airborne radiometric and hyperspectral signatures associated with mineral vectors of uranium mineralization. In the first chapter, we compared two methods and techniques for handling and integration data to build predictive maps to support uranium mineral exploration. The maps compiled by the first technique were based on statistical analysis of the variables of position and variability. While the second method, based in Fuzzy Logic, compiled self-explanatory maps untried in mineral exploration for the commodity U. At this juncture, prospective areas with high potential were evidenced from the data integration of airborne gamma-ray. The second chapter, discuss the methods and techniques for hyperspectral remote sensing and digital image processing for airborne scanner HyMap image. The goal of this study was the analysis of hyperspectral signatures of calc-silicate paragenesis of Mary Kathleen Mine exposed by HyMap spectrum. Part of this mineral association consists of allanita, uraninite, andradite, epidote, hornblende, calcite and scapolite. Also, the spectra nalysis revealed occurrence of minerals such as goethite, kaolinite and montmorillonite nearby mining an open pit mine. The maps on mineral abundance resulting from the methods of hyperspectral classification of Spectral Angle Mapper (SAM) e Mixture Tuned Matched Filtering (MTMF), after compile mineral abundance maps were combined in RGB color space. This strategy allowed enhancing areas of domain and mineral mix with great applicability to uranium mineral exploration / Mestrado / Geologia e Recursos Naturais / Mestre em Geociências
18

Use of remote sensing and GIS in a risk assessment of gold and uranium mine residue deposits and identification of vulnerable land use

Sutton, Malcolm William 29 April 2013 (has links)
A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Environmental Science Johannesburg, November 2012. / Acid rock drainage (ARD) and dust are potential consequences of gold and uranium mine residue deposits (MRDs) on the Witwatersrand basin. Urbanisation has taken place around mines and, with the curtailing of mining activities and clearing of land previously covered by MRDs, there is pressure to use this land for residential, industrial and agricultural purposes. However, mining companies historically were not required to provide pollution control measures and there is evidence for contamination of land and water. Thus, there is a need to prioritise contamination sources for mitigation and to understand the extent of contamination and potential risks associated with different categories of land-use on mining land. The aim of my study was to conduct a first-order risk assessment to aid in identifying vulnerable land use in the vicinity of gold and uranium mining, and prioritising MRDs, including footprints, for mitigation. To achieve this I constructed a Geographical Information System (GIS) using publicly available spatial data, and then tested the usefulness of historical aerial photographs and remote sensing imagery for mapping MRDs and impacts of MRD origin under Highveld conditions (i.e. a seasonal climate with summer rainfall and annual evapotranspiration of >2.5 times mean annual precipitation). The Ekurhuleni Metropolitan Municipality (EMM; 1923 km2) is an area of extensive historical mining with major urbanisation, while retaining areas for agricultural land use; thus it was selected as a representative study site. I used a numerical rating scheme, which combined a number of parameters in two separate stages to calculate a risk index. The first stage involved the classification of hazards associated with MRDs while the second involved an assessment of land use vulnerability based on exposure pathways and proximity. Historical aerial photographs (1938, 1964 and 2003) and the Chamber of Mines (CoM) Dump Indexes were used to identify and classify MRDs in terms of basic geotechnical properties, current status and historical failure. Multi-spectral data, acquired over two years (2002 and 2003) in two seasons (spring and summer) by the TERRA satellite’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor, were used to compile thematic images, indicating potential contamination of surrounding land. It was intended that a zone of influence could be distinguished for each MRD enabling me to rate the hazard severity. The thematic images I selected included primary minerals (pyrophyllite and chlorite), secondary minerals (copiapite and jarosite), an indicator of uranium-bearing ore (referred to as mincrust) and the normalised difference vegetation index (NDVI). These minerals were chosen as potential indicators of different transport routes of contaminants and I tested their associations with different features and land use. I also tested for seasonal differences in the detection of these minerals, and used NDVI to examine the masking effect of active vegetation. I found GIS to be well suited for combining the various forms of spatial data and providing information about MRDs, aqueous pathways, proximity to vulnerable land uses and impacted areas. However, I found that the potential severity of the hazards posed by each MRD, as indicated by a zone of influence, could not be determined from aerial photographs and ASTER alone. I therefore utilised the findings expressed in the literature survey to assign ratings for the different classes of MRDs. The vulnerability assessment was also supplemented by literature review to rate land uses based on human exposure pathways. I determined that MRDs (including footprints) cover 4.1% of EMM, with slimes dams, totalling 3.5%, occupying the majority of this area. I found that 64% of slimes dams had failed prior to 2003 and I plotted a further 0.6% of EMM covered by visible mine residue spillage. Fifty three percent of MRDs were situated within 100 m of drainage lines or old wetlands, while 52% of these (i.e. 27% of the total) had been constructed in the watercourse. I also found that 15% were constructed on dolomites. Informal settlements were located on or bordering 6% of MRDs, with 41% of MRDs within 1 000 m. Eighty eight percent of MRDs were found within 1 000 m of formal residential areas, 71% within 500 m, and formal settlements were located on or bordering 5% of MRDs. Twenty three percent of MRDs were located within 500 m of agricultural land, while 35% were within 1 000 m; and industrial land use was on 9% of MRDs (footprints), with 40% of MRDs being within 500 m of industrial areas and 61% within 1 000 m I found that chlorite did not provide a ‘signature’ of gold and uranium mine residue, whereas the other four minerals did. I also found that, of the two seasons examined (spring and summer), the best time to take an ASTER image to detect mineral signatures of gold and uranium mine contamination is after a few dry days following the first spring rains. For this reason, I used the ASTER taken in late October (spring) 2003 to examine associations with pathways and land use. I found more pyrophyllite and copiapite on industrial and business land use than background, which I suggest is associated with the settling of windborne dust on large and flat roofs; although, in the case of copiapite this could be related to the oxidation of settled wind blown pyrite material. I found jarosite to be a reliable indicator of mine residue, which, together with mincrust, helped me identify contamination in former agricultural holdings, which are now a township. Although, chemically undefined, mincrust was a useful indicator of contamination, as I found it to be reliably detected on MRDs (including footprints), mine residue spillage, wetlands and other contaminated sites, and absent from known uncontaminated sites. Furthermore, it was not necessarily masked by active vegetation, whereas copiapite, jarosite and pyrophyllite were. Mincrust was also detected on irrigated agricultural land with an odds ratio of between 10 to 36 times greater than for rain-fed. Consequently, the most likely pathway for mincrust is the aqueous. The mincrust signature, together with historical aerial photographs, also assisted me to identify historical mining along Black Reef outcrops, through detection in a wetland upstream of known mining activities. The culmination of my study was a risk class and index for MRDs from which ‘risk maps’ were produced. These maps provide a guide to the level of risk posed by each MRD to the surrounding land use. Of the total 287 MRDs (including footprints) identified in the EMM, 50% were classified lower-risk; 40% medium-risk; 10% higher-risk and 0% as much higher risk. The lower-risk MRDs were predominantly rock dumps, whereas the higher-risk MRDs were slimes dams. The findings from my study will contribute to meaningful recommendations for future land use and enable mining companies, landowners, developers and government to allocate their resources judiciously (i.e. appropriate to the level of risk). The results of this study have been published as: Sutton, M.W., Weiersbye, I.M., Galpin, J.S and Heller, D., 2006. A GIS-based history of gold mine residue deposits and risk assessment of post-mining land uses on the Witwatersrand Basin, South Africa. In: A. B. Fourie and M. Tibbett (eds.), Mine Closure 2006: Proceedings of the 1st International Seminar on Mine Closure, Perth, ISBN: 0-9756756-6-4, pp. 667–678 (Appendix I). Sutton, M.W. and Weiersbye, I.M., 2007. South African legislation pertinent to gold mine closure and residual risk. In: A.B. Fourie, M. Tibbett and J. Wiertz (eds.), Mine Closure 2007: Proceedings of the 2nd International Seminar on Mine Closure, Santiago, ISBN: 978-0-9804185-0-7, pp. 89–102 (Appendix II). Sutton, M.W. and Weiersbye, I.M., 2008. Land use after mine closure – Risk assessment of gold and uranium mine residue deposits on the eastern Witwatersrand, South Africa. In: A.B. Fourie, M. Tibbett, I.M. Weiersbye and P.J. Dye (eds.), Mine Closure 2008: Proceedings of the 3rd International Seminar on Mine Closure, Johannesburg, ISBN: 978-0-9804185-6-9, pp. 363–374 (Appendix III).
19

Detecção de bactérias redutoras de sulfato em efluente e sedimento de mina de urânio

Sheila Kênia de Almeida 17 August 2005 (has links)
Um dos graves problemas ambientais oriundos da indústria de mineração é a drenagem ácida de mina que ocorre quando a pirita e outros minerais sulfetados são oxidados devido à presença de oxigênio e água, produzindo ácido sulfúrico que solubiliza metais presentes no solo/rocha. Em uma planta das Indústrias Nucleares do Brasil INB, na Unidade de Tratamento de Minérios (UTM) este problema tem se pronunciado de forma preocupante levando a dissolução de espécies radioativas e metálicas presentes. O tratamento da água ácida usando bactérias redutoras de sulfato, proporciona decréscimo da acidez que é decorrente da redução do sulfato a sulfito e precipitação dos metais como sulfetos. Nesse contexto, o presente estudo foi realizado visando a caracterizar sazonalmente e espacialmente populações de bactérias redutoras de sulfato (BRS) nos efluentes líquidos e amostras de sedimento da cava da mina (CM) e nos bota-foras 4 e 8 (BF4 e BF8) coletadas na UTM. Tais informações poderão permitir posteriormente, estudar mecanismos de biomanipulação a fim de remediar situações impactantes. Menores valores de pH , abaixo de 3,5, foram medidos no período de março a abril em amostras de água da cava da mina e a maior população de BRS (2,8 NMP. mL-1) foi observada em fevereiro em amostras do BF8. Os valores encontrados para matéria orgânica na água foram menores do que aqueles encontrados no sedimento. A concentração de oxigênio dissolvido na água variou de 0,65 g/L a 13,3 g/L. As amostras de sedimento apresentaram maiores valores de BRS (10,2 NMP/mL), quando comparadas com amostras de água (0,63 NMP/mL). Tais resultados eram esperados uma vez que, nas amostras de água coletadas próximas ao sedimento foram observadas menores concentrações de oxigênio dissolvido (7,10g/L) e maiores concentrações de matéria orgânica disponível (17,0 mg/L) quando os resultados foram comparados com aqueles obtidos para amostras de água coletadas na superfície (0,004mg/L). Os resultados mostram, portanto, que o efluente ácido gerado apresenta altos teores de metais estáveis e radioativos, sulfato, baixo pH e presença de bactérias redutoras de sulfato. / One of the most serious environmental problems created by the mining industry is acid mine drainage. In one plant of Nuclear Industries of Brazil - INB, this problem is a matter of concern. The presence of iron sulfites, such as pyrite, generates water with acidity above the levels allowed by the legislation and therefore, inappropriate for releasing straight into the environment. The industry maintain a high cost treatment in acid water from mines and waste disposal which consists in neutralizing and precipitating heavy metals. The treatment of acid water using SRB (sulfate-reducing bacteria) has been used in other countries with quite good technical results as well as economical advantages and thus, the object of this research. The use Sulfate Reducing Bacteria takes to a decreasing of the acidity by reducing sulfate to sulfite and precipitating the stable metals as sulfides. A seasonal study was carried out on the sulfate-reducing bacteria present in the liquid effluent discharged from two wastes disposal of the uranium mine, in phase of decommission, in Caldas/MG. This study shows the presence of SRB in the analyzed environmental, as well as some factors that are related with the amount of SRB presents, such as: dissolved oxygen, pH and organic matter. SRB was presented in water samples with high concentrations of heavy metals and low pH values, as well as in samples with high oxygen levels. The sediment samples were the preferential place for SRB occurrence and site BF8 presented the highest values of SRB.
20

Avaliação da qualidade das águas superficiais no entorno das instalações minero-industriais de urânio de Caldas, Minas Gerais / QUALITY ASSESSMENT OF SURFACE WATERS IN VICINITY OF THE CALDAS URANIUM MINING AND INDUSTRIAL FACILITIES, MINAS GERAIS

Carlos Alberto de Carvalho Filho 09 December 2014 (has links)
Nenhuma / Esta tese apresenta uma avaliação da qualidade das águas superficiais no entorno de uma instalação minero-industrial para produção de urânio, a Unidade de Tratamento de Minérios de Caldas (UTM-Caldas). O objetivo é verificar se os corpos dágua dessa instalação foram impactados por efluentes provenientes da pilha de rocha estéril n 4 (BF4) e da Bacia de Rejeitos (BR). O principal problema ambiental da UTM-Caldas, atualmente em processo de descomissionamento, é a geração de drenagem ácida de mina (DAM). Para o desenvolvimento do trabalho foram implantadas doze estações de amostragem nas bacias que drenam a área da UTM-Caldas: rio Taquari, córrego da Consulta e ribeirão Soberbo. Duas das estações foram posicionadas respectivamente no interior da Bacia Nestor Figueiredo (BNF), bacia de retenção dos efluentes do BF4, e do tanque de deposição do rádio, denominado D2, para onde vertem os efluentes da BR. O monitoramento se desenvolveu em 2010 e 2011, com a determinação de quarenta e dois parâmetros físico-químicos, biológicos e radioativos. Os dados obtidos foram tratados por diferentes abordagens metodológicas, incluindo a distribuição espacial das medianas das determinações, diagramas hidrogeoquímicos, estudo de isótopos estáveis e do cálculo do background geoquímico, além da aplicação de índices de qualidade das águas. De maior relevância, os resultados mostraram que efluentes provenientes da BNF contribuíram para que os corpos dágua a jusante, principalmente o córrego da Consulta, apresentassem contaminação para flúor, cádmio, urânio, zinco, alumínio, manganês e acidez, assim como foram responsáveis para o enriquecimento em sulfato, cálcio, arsênio, magnésio, 238U, 226Ra, 232Th e 228Ra. Os resultados indicaram que efluentes advindos do D2 causaram um enriquecimento em cálcio, flúor, sulfato e molibdênio nas águas do ribeirão Soberbo. As águas do córrego da Consulta, imediatamente a jusante da BNF, receberam a pior classificação do índice WQI/CCME, ou seja, pobre. / This thesis presents an evaluation of the quality of surface waters in the surroundings of the industrial-mineral facilities for the production of uranium owned by the Caldas Ore Treatment Unit (UTM-Caldas), aiming to verify whether the water bodies downstream the plant, were impacted by effluents from the Waste Rock Pile 4 (BF4), and from the Tailings Dam (BR). The main environmental problem of UTM-Caldas, currently in decommissioning process, is the generation of Acid Mine Drainage (AMD). In order to perform the research, twelve sampling stations were established in the watersheds around UTC: the Soberbo and Consulta creeks, and the Taquari river. One of the stations was located, inside the BNF (retention pond that receives effluents from BF4), and another at D2 (a settling tank for radium, which receives the effluents from BR). A monitoring plan has been developed, comprising four sampling campaigns in 2010 and 2011. It involved the measurement of forty-two physical, chemical, biological and radioactive parameters. The data obtained were processed by different methodological approaches, including the spatial distribution of medians of the recorded results, hydrogeochemical diagrams, stable isotopes measurements and evaluation of the geochemical background, besides the use of indexes for water quality. Of greater relevance, the results indicated that the effluents from the BNF contributed to the contamination, mainly of the Consulta creek, by F-, Cd, U, Zn, Al, Mn, besides increased acidity and enrichment of SO42-, Ca, As, 238U, 226Ra, 232Th, and 228Ra. The results indicated that the effluents discharged at D2 caused the waters of the Soberbo creek to be enriched in Ca, F-, Mo and SO42-. The stretch of the Consulta creek immediately downstream the BNF received the worst classification according with the WQI/CCME Index, i.e. "poor".

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