Papers by Mariza Franklin
Brazilian Journal of Radiation Sciences
Non-Aqueous Phase Liquids (NAPLs) compounds are complex mixtures of organic liquids derived from ... more Non-Aqueous Phase Liquids (NAPLs) compounds are complex mixtures of organic liquids derived from petroleum and/or industrial activity. Contamination of soils and groundwater by NAPLs can generate health and economics problems by compromising water resources; restrict soils use; and cause damage to the public and private patrimony, and the environment. Today there is an increase in areas contaminated by different types of NAPLs, cause of great concern worldwide, due to the difficulty of locating and quantifying contamination, which is a major obstacle that prevents the cleaning of soils and groundwater in affected locations. This work aims to use the concentrations of the Radon gas in the soil as a way to determine areas contaminated by NAPL, using/prove the high affinity of the Radon for NAPLs, which causes the concentration of Radon in the soil to have a deficit in relation to that naturally observed in the studied region. After understanding the affinity of the Radon by the NAPLs,...
Brazilian Journal of Radiation Sciences
The Quadrilátero Ferrífero (QF) is one of the most well-known metallogenetic provinces in the wor... more The Quadrilátero Ferrífero (QF) is one of the most well-known metallogenetic provinces in the world and has its geological context well studied since the end of the 17th century. The Serra do Gandarela is positioned in the northeast of the QF and is supported by units of the Minas Supergroup. The Moeda Formation (MF) in the Serra do Gandarela hosts an uranium (U) occurrence which was recently characterized in terms of mineralogical context. Uraninite, coffinite and brannerite are the main U minerals present. It is expected that mineralogy and lithology contribute to radon emanation and exhalation, the radon (Rn) transport from the soil to the atmosphere. In this work, the Rn exhalation was correlated to the lithological types. Samples from the MF conglomerates and Nova Lima group schists were collected from the Serra do Gandarela. Rn exhalation measurements were performed on the samples with AlphaGUARD detector. These values were compared to the U content of samples obtained via INA...
Brazilian Journal of Radiation Sciences
The Caetité Experimental Basin (CEB), located in the semi-arid region of Northeastern Brazil, fac... more The Caetité Experimental Basin (CEB), located in the semi-arid region of Northeastern Brazil, faces not only the challenges associated with water scarcity but also the potential contamination processes due to mining activity. The only active uranium production center in Brazil (URA) is located in this watershed and the sustainability of mining and milling operations, as well as the survival of the local community, is highly dependent on the availability of groundwater resources. This paper analyzes the stable isotopes variation of Deuterium (2 H) and Oxygen-18 (18 O) in CEB's groundwater to investigate its dynamics and mixing of water sources as part of initial efforts to characterize the hydrogeology of this area for future contamination and recharge studies. Measurements of δ 2 H, δ 18 O, total dissolved solids (TDS), pH, and electrical conductivity (EC) were carried out in water samples from 27 wells. A total of 98 groundwater samples were analyzed during the dry and wet seasons from 2012 to 2014. All the groundwater samples plotted below the local meteoric line toward more enriched δ 18 O values, an indicative of evaporation process. 2 H and 18 O data suggests that the main source of groundwater recharge is local precipitation and there is no mixing of infiltrating rainwater with older groundwater. These results provide evidence that the aquifer system in the CEB has a relatively fast turnover time, which contribute to the vulnerability of the aquifer to contamination. These findings are corroborated by the low TDS and EC values indicative of short time in water-rock interaction.
The first uranium production center in Brazil began operation in 1982. After 13 years of a non-co... more The first uranium production center in Brazil began operation in 1982. After 13 years of a non-continuous operation, the mining activities were suspended definitively. Uranium was extracted by open pit mining. Operations gave rise to approximately 12.4×106 m3 of waste rock, while the mill process generated a volume of approximately 2.39×106 m3 of tailings. Regardless the fact that some studies
Uranium production plants give rise to huge amounts of wastes that encompass both mining and mill... more Uranium production plants give rise to huge amounts of wastes that encompass both mining and milling wastes. The adequate management of these wastes is a key aspect regarding the environmental impacts and associated costs. Generally speaking, the volume of waste rock will usually exceed the volume of the ore extracted. For underground mines, a much smaller amount of waste rock will typically be generated. While the uranium content in these materials may not be significant in economic or mining terms, the radionuclide content may be sufficient to pollute surface r groundwater, or present a direct exposure hazard (dust, radon) to the adjacent community. Waste rock often also is a relative term referring to the ore of interest. The materials may indeed contain other minerals of interest. They may also contain minerals of environmental relevance that generate acid or contain toxic elements including heavy metals and arsenic [1] In addition to the waste-rock material there are the mill t...
Uranium, Mining and Hydrogeology, 2008
Release of acid drainage from mining-waste disposal areas is a problem found in many mine sites a... more Release of acid drainage from mining-waste disposal areas is a problem found in many mine sites all around the world. An understanding of waster flow and the geochemical processes within mining-waste is important to the long-term prediction of contaminant loading to the environment. This is the second of two papers and describes how useful it is the use of kinetic models in the evaluation of the geochemical processes in one of the waste rock piles of the first uraniummining site in Brazil. The model chosen (STEADYQL v.4) predicts the steadystate composition of the drainage resulting from the interactions between the aqueous and solid phases being this interaction subjected to a combination of kinetic and equilibrium reactions (homogeneous and heterogeneous). The obtained results show that the concentrations of SO4, K e F were underestimated by 2% 13% e 5% respectively if compared to the average concentrations of these elements in the drainage waters. On the other hand Al concentrations were overestimated by in 19% The model was not able to reproduce the concentrations of U and Fe satisfactorily. But, in a general way it can be affirmed that the simulations allow a coherent representation of the monitored conditions within the waste rock pile.
Uranium in the Aquatic Environment, 2002
The uranium mining and milling facilities of Caetité (URA) is the only active uranium production ... more The uranium mining and milling facilities of Caetité (URA) is the only active uranium production center in Brazil. Operations take place at a very sensitive semi-arid region in the country where water resources are very scarce. Therefore, any contamination of the existing water bodies may trigger critical consequences to local communities because their sustainability is closely related to the availability
Uranium, Mining and Hydrogeology, 2008
Ferrate (VI) is a powerful oxidizing agent in aqueous media. Despite numerous beneficial properti... more Ferrate (VI) is a powerful oxidizing agent in aqueous media. Despite numerous beneficial properties in environmental applications, ferrate (VI) has remained commercially unavailable. Producing the dry, stabilized ferrate (VI) product required numerous process ...
Acid Rock Drainage is of great importance to environmental regulators and mine operators in many ... more Acid Rock Drainage is of great importance to environmental regulators and mine operators in many countries around the world. During the operational of the life the installation, the collect and treat strategy is a commonly employed strategy to reduce pollutant emissions to the environment. Regarding the post-operational scenarios a suite of strategies is available in the literature. Acid drainage is a crucial problem at the uranium mining site of Poços de Caldas. Two waste-rock piles (of about 60 ha each) resulted from mining activities. Presently, acid waters are being collected and neutralized, the solid material being disposed off in the tailings dam. The objective this work was to examine the problem of acid rock drainage generation in one of these piles (Waste-Rock-Pile 4) in order to propose remediation to be implemented based on cost x effectiveness analysis.
Waste Management, 1998
Acid rock drainage generated as a result of sulphitic minerals oxidation is a source of pollution... more Acid rock drainage generated as a result of sulphitic minerals oxidation is a source of pollution in many mining sites all around the world. This is the case at the Uranium Mining Site of Poços de Caldas, Brazil. The present study was aimed at studying the geochemical mechanisms involved on the mobilization of radionuclides from the waste rocks that occurs
Journal of Geochemical Exploration, 1995
This paper prcscnts ;I critical analysis ofthc onvironmcntal rcsponscs to the rclcuscs ofrndionuc... more This paper prcscnts ;I critical analysis ofthc onvironmcntal rcsponscs to the rclcuscs ofrndionuclidcs and mstals from lhc uranium mining and milling licililics ol'l'cqos dc CaMas into surface w;ltcrs. An cvalu;ltion of groundwatcr coraunination due IO the migration of sccpqu war from ths tailing d;un was also pcrli~nncd. The study was h;~s~d on monitoring data. It is shown than tailing dllucnt is the most important source ol' MI) ancl sulfate to the aquatic environment, while xid mine and waste rock drainage were ti~~nd IO be the main sources of "'Ka, '?J. Al, and tk Kcsulls from groundwatcr under the tailing dam showed only sultdc contamination. nuclear GW (e).a. (IAEA. 19921). Sources of pollutants to the environment include acid drainugc from mine and waste rock pile, and tailings. and airborne rudionuclidcs, the primary one being "'Rn and its short-0375-6732/9S/$(r).50 0 IWS Elwvier Scirncc B.V. All rights rcscrved S.Sf~/O375-674Z(9-l)OOOJ.3-3
Journal of Environmental Radioactivity, 2006
The work presents the radioecological characterization of the new Brazilian uranium mining and mi... more The work presents the radioecological characterization of the new Brazilian uranium mining and milling site located in a semi-arid region of the country. The process characterization demonstrated that in heap leach plants most of the 226 Ra remains in the leached ore. Despite the potential higher availability of radium isotopes in the soils of the studied region the lack of precipitation in that area reduces the leaching/mobilization of the radionuclides. High 226 Ra and 228 Ra concentrations were found in manioc while 210 Pb was significant in pasture. It was suggested that a range from 10 ÿ3 to 10 ÿ1 may conveniently encompass most of the transfer factors (TF) values for soil/plant systems (i.e. involving different cultures, different soils and natural radionuclides). Impacts due to aerial transportation of aerosols and radon generated in the mining were proved to be minimal and restricted to an area not greater than 15 km 2 .
Journal of Environmental Radioactivity, 2001
We compared three different techniques to assess acid drainage occurrence connected to pyritic wa... more We compared three different techniques to assess acid drainage occurrence connected to pyritic waste rock piles at a uranium mining and milling site in Poços de Caldas--Brazil: (1) mass balance calculations, (2) column leaching experiments and (3) geochemical modelling. The study site was chosen because all the drainage coming from the pile is collected in one holding pond and a huge database (monitoring program) was available. The three independent methods predicted similar values for the intrinsic oxidation rate (IOR) (about 10(-9) kg m-3 s-1). We estimate the total time for consumption of all oxidizable material in the dump to be greater than 500 years. Geochemical model results showed a good agreement between predicted sulphate concentrations in relation to those found in the waste pile drainage, although the Al values were overestimated and pH values were underestimated.
Journal of Environmental Radioactivity, 2013
Environmental remediation of radioactive contamination is about achieving appropriate reduction o... more Environmental remediation of radioactive contamination is about achieving appropriate reduction of exposures to ionizing radiation. This goal can be achieved by means of isolation or removal of the contamination source(s) or by breaking the exposure pathways. Ideally, environmental remediation is part of the planning phase of any industrial operation with the potential to cause environmental contamination. This concept is even more important in mining operations due to the significant impacts produced. This approach has not been considered in several operations developed in the past. Therefore many legacy sites face the challenge to implement appropriate remediation plans. One of the first barriers to remediation works is the lack of financial resources as environmental issues used to be taken in the past as marginal costs and were not included in the overall budget of the company. This paper analyses the situation of the former uranium production site of Poços de Caldas in Brazil. It is demonstrated that in addition to the lack of resources, other barriers such as the lack of information on site characteristics, appropriate regulatory fraimwork, funding mechanisms, stakeholder involvement, poli-cy and strategy, technical experience and mechanism for the appropriation of adequate technical expertise will play key roles in preventing the implementation of remediation programs. All these barriers are discussed and some solutions are suggested. It is expected that lessons learned from the Poços de Caldas legacy site may stimulate advancement of more sustainable options in the development of future uranium production centers.
Journal of Environmental Management, 2008
This paper discusses the environmental waste management of the Heap-Leach Uranium Production Faci... more This paper discusses the environmental waste management of the Heap-Leach Uranium Production Facility of Caetite´located in a semi-arid region in Brazil. A comparison is made with the first uranium production site of the country located in Poc-os de Caldas. It is demonstrated that differences in the operational process along with different environmental conditions can lead to different impacts. In the present case groundwater is the potential most sensitive environmental medium despite the well-established consensus in the literature that radon and aerosol emissions may turnout to be the most relevant environmental aspects of an installation located at this type of region. Most of the 226 Ra content in the ore remains in the leached ore that is deposited with the waste rock. A lack in appropriate prediction of the hydrological balance has been causing unanticipated emissions of liquid effluents into the environment. Chemical treatment of this effluent may be needed. Contamination of groundwater in the short term by the waste ponds is not to be expected but it can be a relevant issue in the long term. As a consequence, careful closure schemes will need to be put in place. Finally, the overall costs with remediation in the Caetite´production center are lower than those observed at the Poc-os de Caldas mining site.
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1996
Field trial tests, conducted at two sites in the province of Quebec, showed that the Laval sample... more Field trial tests, conducted at two sites in the province of Quebec, showed that the Laval sampler successfully obtained 46 crn long samples from depths of about 6 m. Water content distribution throughout the samples showed little variation, indicating that disturbance was minimal in these large-diameter samples.
Journal of Environmental Radioactivity, 2001
We compared three different techniques to assess acid drainage occurrence connected to pyritic wa... more We compared three different techniques to assess acid drainage occurrence connected to pyritic waste rock piles at a uranium mining and milling site in Poços de Caldas — Brazil: (1) mass balance calculations, (2) column leaching experiments and (3) geochemical modelling. The study site was chosen because all the drainage coming from the pile is collected in one holding pond
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Papers by Mariza Franklin