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E. V. Silva-filho - One of the best experts on this subject based on the ideXlab platform.
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Influence of acid Sand Pit lakes in surrounding groundwater chemistry, Sepetiba sedimentary basin, Rio de Janeiro, Brazil
Journal of Geochemical Exploration, 2012Co-Authors: E. D. Marques, Décio Tubbs, Olga Venimar O. Gomes, E. V. Silva-filhoAbstract:Abstract Seropedica–Itaguai Sand mining district has an important role in the Rio de Janeiro Metropolitan Region, supplying approximately 70% of the Sand for civil construction. The Sand extraction process removes surface sedimentary layers (with quartz–feldspatic composition), increasing water table in the mined Pit. However, this activity causes some chemical and physico-chemical changes in the water, such as the oxidation of reduced sediments lowering pH values (reaching values 4 concentration (reaching more than 90 mg.l − 1 ). The relatively low pH values of those waters promote an increase of weathering rate, especially the silicate minerals and, as a consequence, high Al concentrations (> 10 mg.l − 1 ) are obtained. Four Sand Pit lakes and four wells located close to each other were sampled from November 2005 to March 2007. The groundwater physico-chemical parameters and the dissolved species in the Sand Pit lakes are controlled by Sand extraction process as well as the rainfall regime. During dry season the reduced sediments become exposed by the water table drawdown, promoting oxidation which releases H + and other ions present in those lithologies. The increase of water table during wet season induces lithologies lixiviation, increasing the concentration of dissolved species in groundwater. However it also promotes a decreasing of pH values due to the diluting factor induced by rainwater infiltration. During dry season, the Sand Pit lakes have high pH values due to buffering action caused by the dissolved species present, leading to the ion shielding for H + , caused by evapoconcentration process (high ionic strength for this season). The evapoconcentration conditions along that season promote the preciPitation of some complex salts of Na + , Mg 2 + , Cl − and sulfate, decreasing the concentrations of major dissolved species. The opposite occurs during wet season, where pH values increase due the rainwater input, breaking the ion shielding (lower ionic strength) and dissolving some preciPitated compounds (increasing the concentrations of major dissolved constituents). PHREEQC and WATEQ4F modeling were used for Sand Pit lakes and groundwater samples in order to show the Al behavior in these specific environments, which could be a limiting factor for an aquaculture activity towards the end of mining activities. The Sand Pit lakes showed Al 3 + as the main dissolved species in both dry and wet season, while groundwater presented Al(OH) 2 + and Al(OH) 2 + , which are the most toxic species for aquatic life. The dissolved aluminum concentration in the studied environments was considered by the minerals formation, which the SO 4 2 − salts complex are the main Al scavengers, followed by the silicate minerals in both seasons. The information provided by this study gives an insight to the conditions of aquaculture in Sand Pit lakes, having peculiar characteristics. On the other hand, the dissolved aluminum should be considered in groundwater due to the possible water contamination, considering that wells used for water consumption are prevalent in the region.
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Geochemical behavior and dissolved species control in acid Sand Pit lakes,Sepetiba sedimentary basin, Rio de Janeiro, SE - Brazil
Journal of South American Earth Sciences, 2010Co-Authors: E. D. Marques, S. M. Sella, Edison Dausacker Bidone, E. V. Silva-filhoAbstract:This work shows the influence of pluvial waters on dissolved components and mineral equilibrium of four Sand Pit lakes, located in the Sepetiba sedimentary basin, SE Brazil. The Sand mining activities promote sediment oxidation, lowering pH and increasing SO4 contents. The relatively high acidity of these waters, similar to ore Pit lakes environment and associated acid mine drainage, increases weathering rate, especially of silicate minerals, which produces high Al concentrations, the limiting factor for fish aquaculture. During the dry season, basic cations (Ca, Mg, K and Na), SiO2 and Al show their higher values due to evapoconcentration and pH are buffered. In the beginning of the wet season, the dilution factor by rainwater increases SO4 and decreases pH values. The aluminum monomeric forms (Al (OH) 2þ and Al(OH)2 ), the most toxic species for aquatic organisms, occur during the dry season, while AlSO4 species predominate during the wet season. Gibbsite, allophane, alunite and jurbanite are the reactive mineral phases indicated by PHREEQC modeling. During the dry season, hydroxialuminosilicate allophane is the main phase in equilibrium with the solution, while the sulphate salts alunite and jurbanite predominate in the rainy season due to the increasing of SO4 values. Gibbsite is also in equilibrium with Sand Pit lakes waters, pointing out that hydrolysis reaction is a constant process in the system. Comparing to SiO2, sulphate is the main Al retriever in the Pit waters because the most samples (alunite and jurbanite) are in equilibrium with the solution in both seasons. This Al hydrochemical control allied to some precaution, like pH correction and fertilization of these waters, allows the conditions for fishpond culture. Equilibrium of the majority samples with kaolinite (Ca, Mg, Na diagrams) and primary minerals (K diagram) points to moderate weathering rate in Sand Pit sediments, which cannot be considered for the whole basin due to the anomalous acidification of the studied waters. 2010 Published by Elsevier Ltd.
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Hydrogeochemistry of Sand Pit Lakes at Sepetiba Basin, Rio de Janeiro, Southeastern Brazil
Water Air and Soil Pollution, 2008Co-Authors: E. D. Marques, S. M. Sella, W. Z. Mello, L. D. Lacerda, E. V. Silva-filhoAbstract:Four Sand Pit lakes, at the Rio de Janeiro Sand Mining District, were monitored from November 2003 to November 2005, in order to characterize their hydrogeochemistry aiming to provide information to their possible use as fishponds at the end of mining activities. The results show diluted waters (low electrical conductivity) with low pH (
E. D. Marques - One of the best experts on this subject based on the ideXlab platform.
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Influence of acid Sand Pit lakes in surrounding groundwater chemistry, Sepetiba sedimentary basin, Rio de Janeiro, Brazil
Journal of Geochemical Exploration, 2012Co-Authors: E. D. Marques, Décio Tubbs, Olga Venimar O. Gomes, E. V. Silva-filhoAbstract:Abstract Seropedica–Itaguai Sand mining district has an important role in the Rio de Janeiro Metropolitan Region, supplying approximately 70% of the Sand for civil construction. The Sand extraction process removes surface sedimentary layers (with quartz–feldspatic composition), increasing water table in the mined Pit. However, this activity causes some chemical and physico-chemical changes in the water, such as the oxidation of reduced sediments lowering pH values (reaching values 4 concentration (reaching more than 90 mg.l − 1 ). The relatively low pH values of those waters promote an increase of weathering rate, especially the silicate minerals and, as a consequence, high Al concentrations (> 10 mg.l − 1 ) are obtained. Four Sand Pit lakes and four wells located close to each other were sampled from November 2005 to March 2007. The groundwater physico-chemical parameters and the dissolved species in the Sand Pit lakes are controlled by Sand extraction process as well as the rainfall regime. During dry season the reduced sediments become exposed by the water table drawdown, promoting oxidation which releases H + and other ions present in those lithologies. The increase of water table during wet season induces lithologies lixiviation, increasing the concentration of dissolved species in groundwater. However it also promotes a decreasing of pH values due to the diluting factor induced by rainwater infiltration. During dry season, the Sand Pit lakes have high pH values due to buffering action caused by the dissolved species present, leading to the ion shielding for H + , caused by evapoconcentration process (high ionic strength for this season). The evapoconcentration conditions along that season promote the preciPitation of some complex salts of Na + , Mg 2 + , Cl − and sulfate, decreasing the concentrations of major dissolved species. The opposite occurs during wet season, where pH values increase due the rainwater input, breaking the ion shielding (lower ionic strength) and dissolving some preciPitated compounds (increasing the concentrations of major dissolved constituents). PHREEQC and WATEQ4F modeling were used for Sand Pit lakes and groundwater samples in order to show the Al behavior in these specific environments, which could be a limiting factor for an aquaculture activity towards the end of mining activities. The Sand Pit lakes showed Al 3 + as the main dissolved species in both dry and wet season, while groundwater presented Al(OH) 2 + and Al(OH) 2 + , which are the most toxic species for aquatic life. The dissolved aluminum concentration in the studied environments was considered by the minerals formation, which the SO 4 2 − salts complex are the main Al scavengers, followed by the silicate minerals in both seasons. The information provided by this study gives an insight to the conditions of aquaculture in Sand Pit lakes, having peculiar characteristics. On the other hand, the dissolved aluminum should be considered in groundwater due to the possible water contamination, considering that wells used for water consumption are prevalent in the region.
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Geochemical behavior and dissolved species control in acid Sand Pit lakes,Sepetiba sedimentary basin, Rio de Janeiro, SE - Brazil
Journal of South American Earth Sciences, 2010Co-Authors: E. D. Marques, S. M. Sella, Edison Dausacker Bidone, E. V. Silva-filhoAbstract:This work shows the influence of pluvial waters on dissolved components and mineral equilibrium of four Sand Pit lakes, located in the Sepetiba sedimentary basin, SE Brazil. The Sand mining activities promote sediment oxidation, lowering pH and increasing SO4 contents. The relatively high acidity of these waters, similar to ore Pit lakes environment and associated acid mine drainage, increases weathering rate, especially of silicate minerals, which produces high Al concentrations, the limiting factor for fish aquaculture. During the dry season, basic cations (Ca, Mg, K and Na), SiO2 and Al show their higher values due to evapoconcentration and pH are buffered. In the beginning of the wet season, the dilution factor by rainwater increases SO4 and decreases pH values. The aluminum monomeric forms (Al (OH) 2þ and Al(OH)2 ), the most toxic species for aquatic organisms, occur during the dry season, while AlSO4 species predominate during the wet season. Gibbsite, allophane, alunite and jurbanite are the reactive mineral phases indicated by PHREEQC modeling. During the dry season, hydroxialuminosilicate allophane is the main phase in equilibrium with the solution, while the sulphate salts alunite and jurbanite predominate in the rainy season due to the increasing of SO4 values. Gibbsite is also in equilibrium with Sand Pit lakes waters, pointing out that hydrolysis reaction is a constant process in the system. Comparing to SiO2, sulphate is the main Al retriever in the Pit waters because the most samples (alunite and jurbanite) are in equilibrium with the solution in both seasons. This Al hydrochemical control allied to some precaution, like pH correction and fertilization of these waters, allows the conditions for fishpond culture. Equilibrium of the majority samples with kaolinite (Ca, Mg, Na diagrams) and primary minerals (K diagram) points to moderate weathering rate in Sand Pit sediments, which cannot be considered for the whole basin due to the anomalous acidification of the studied waters. 2010 Published by Elsevier Ltd.
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Hydrogeochemistry of Sand Pit Lakes at Sepetiba Basin, Rio de Janeiro, Southeastern Brazil
Water Air and Soil Pollution, 2008Co-Authors: E. D. Marques, S. M. Sella, W. Z. Mello, L. D. Lacerda, E. V. Silva-filhoAbstract:Four Sand Pit lakes, at the Rio de Janeiro Sand Mining District, were monitored from November 2003 to November 2005, in order to characterize their hydrogeochemistry aiming to provide information to their possible use as fishponds at the end of mining activities. The results show diluted waters (low electrical conductivity) with low pH (
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hydrogeochemistry of Sand Pit lakes at sepetiba basin rio de janeiro southeastern brazil
Water Air and Soil Pollution, 2008Co-Authors: E. D. Marques, S. M. Sella, W. Z. Mello, L. D. Lacerda, Emmanoel V SilvafilhoAbstract:Four Sand Pit lakes, at the Rio de Janeiro Sand Mining District, were monitored from November 2003 to November 2005, in order to characterize their hydrogeochemistry aiming to provide information to their possible use as fishponds at the end of mining activities. The results show diluted waters (low electrical conductivity) with low pH (<4) and relatively high sulfate and aluminum concentrations. The major water components (in particular Fe, Mn, SiO2, Al and SO4) are related to water acidity, since it controls solubility of aluminum silicate minerals and Mn and Fe oxides. Fe, Mn and Al availability in these waters are probably associated to organic colloids formation. On the other hand, the SiO2 content, as well as the decrease of Sand mining in rainy season, may partially control Al availability by the formation of hydroxi-aluminum silicates. These geochemical processes together with the interruption of Sand mining in the rainy season and the dilution of Sand Pit lakes water by rainwater can support the use of these Pit lakes as fishpond for aquaculture.
Télesphore Sime-ngando - One of the best experts on this subject based on the ideXlab platform.
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High and differential viral infection rates within bacterial 'morphopopulations' in a shallow Sand Pit lake (Lac de Créteil, France).
FEMS Microbiology Ecology, 2010Co-Authors: A. S. Pradeep Ram, Michael Danger, Jean-françois Carrias, Gérard Lacroix, Mohamad-bashir Arnous, Télesphore Sime-ngandoAbstract:The ecology of viruses in shallow artificial freshwaters is poorly documented and there is no reference for Sand Pit lakes. We examined the seasonal abundances and infection rates of viruses in the Sand Pit Lake Créteil (France). Bacteria were the best predictor of viral abundance (4.0-7.8 × 10(10) viruses L(-1) ), with an average virus-to-bacteria ratio of 13.5 ± 1.9. Virus-induced bacterial mortality (range 37-86%, mean 65%) was higher than that in typical pelagic situations. This was related to high specific contact rates between viruses and bacterial hosts and high burst size (BS) estimates. Seasonal fluctuations in viruses and bacteria were rather homeostatic, although temperature was a major driver of microbial activities. Different bacterial morphotypes, i.e. 'morphopopulations', were analysed. Rod cells dominated the total (90%) and infected (89%) communities. Elongated rods were the most infected (45% of infected cells), whereas fat rods exhibited the highest BS estimates (mean=72 viruses per bacterium) due to a larger specific cell volume. We conclude that the lytic activity of viruses is high and heterogeneous for different bacterial-host phenotypes in the Sand Pit Lake Créteil. A theoretical exercise shows that this can exert a strong influence on the processes occurring in plankton food webs.
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High and differential viral infection rates within bacterial ‘morphopopulations’ in a shallow Sand Pit lake (Lac de Créteil, France)
FEMS microbiology ecology, 2010Co-Authors: A. S. Pradeep Ram, Bashir Arnous, Michael Danger, Jean-françois Carrias, Gérard Lacroix, Télesphore Sime-ngandoAbstract:The ecology of viruses in shallow artificial freshwaters is poorly documented and there is no reference for Sand Pit lakes. We examined the seasonal abundances and infection rates of viruses in the Sand Pit Lake Creteil (France). Bacteria were the best predictor of viral abundance (4.0-7.8 × 10(10) viruses L(-1) ), with an average virus-to-bacteria ratio of 13.5 ± 1.9. Virus-induced bacterial mortality (range 37-86%, mean 65%) was higher than that in typical pelagic situations. This was related to high specific contact rates between viruses and bacterial hosts and high burst size (BS) estimates. Seasonal fluctuations in viruses and bacteria were rather homeostatic, although temperature was a major driver of microbial activities. Different bacterial morphotypes, i.e. 'morphopopulations', were analysed. Rod cells dominated the total (90%) and infected (89%) communities. Elongated rods were the most infected (45% of infected cells), whereas fat rods exhibited the highest BS estimates (mean=72 viruses per bacterium) due to a larger specific cell volume. We conclude that the lytic activity of viruses is high and heterogeneous for different bacterial-host phenotypes in the Sand Pit Lake Creteil. A theoretical exercise shows that this can exert a strong influence on the processes occurring in plankton food webs.
Olga Venimar O. Gomes - One of the best experts on this subject based on the ideXlab platform.
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Influence of acid Sand Pit lakes in surrounding groundwater chemistry, Sepetiba sedimentary basin, Rio de Janeiro, Brazil
Journal of Geochemical Exploration, 2012Co-Authors: E. D. Marques, Décio Tubbs, Olga Venimar O. Gomes, E. V. Silva-filhoAbstract:Abstract Seropedica–Itaguai Sand mining district has an important role in the Rio de Janeiro Metropolitan Region, supplying approximately 70% of the Sand for civil construction. The Sand extraction process removes surface sedimentary layers (with quartz–feldspatic composition), increasing water table in the mined Pit. However, this activity causes some chemical and physico-chemical changes in the water, such as the oxidation of reduced sediments lowering pH values (reaching values 4 concentration (reaching more than 90 mg.l − 1 ). The relatively low pH values of those waters promote an increase of weathering rate, especially the silicate minerals and, as a consequence, high Al concentrations (> 10 mg.l − 1 ) are obtained. Four Sand Pit lakes and four wells located close to each other were sampled from November 2005 to March 2007. The groundwater physico-chemical parameters and the dissolved species in the Sand Pit lakes are controlled by Sand extraction process as well as the rainfall regime. During dry season the reduced sediments become exposed by the water table drawdown, promoting oxidation which releases H + and other ions present in those lithologies. The increase of water table during wet season induces lithologies lixiviation, increasing the concentration of dissolved species in groundwater. However it also promotes a decreasing of pH values due to the diluting factor induced by rainwater infiltration. During dry season, the Sand Pit lakes have high pH values due to buffering action caused by the dissolved species present, leading to the ion shielding for H + , caused by evapoconcentration process (high ionic strength for this season). The evapoconcentration conditions along that season promote the preciPitation of some complex salts of Na + , Mg 2 + , Cl − and sulfate, decreasing the concentrations of major dissolved species. The opposite occurs during wet season, where pH values increase due the rainwater input, breaking the ion shielding (lower ionic strength) and dissolving some preciPitated compounds (increasing the concentrations of major dissolved constituents). PHREEQC and WATEQ4F modeling were used for Sand Pit lakes and groundwater samples in order to show the Al behavior in these specific environments, which could be a limiting factor for an aquaculture activity towards the end of mining activities. The Sand Pit lakes showed Al 3 + as the main dissolved species in both dry and wet season, while groundwater presented Al(OH) 2 + and Al(OH) 2 + , which are the most toxic species for aquatic life. The dissolved aluminum concentration in the studied environments was considered by the minerals formation, which the SO 4 2 − salts complex are the main Al scavengers, followed by the silicate minerals in both seasons. The information provided by this study gives an insight to the conditions of aquaculture in Sand Pit lakes, having peculiar characteristics. On the other hand, the dissolved aluminum should be considered in groundwater due to the possible water contamination, considering that wells used for water consumption are prevalent in the region.
Décio Tubbs - One of the best experts on this subject based on the ideXlab platform.
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Influence of acid Sand Pit lakes in surrounding groundwater chemistry, Sepetiba sedimentary basin, Rio de Janeiro, Brazil
Journal of Geochemical Exploration, 2012Co-Authors: E. D. Marques, Décio Tubbs, Olga Venimar O. Gomes, E. V. Silva-filhoAbstract:Abstract Seropedica–Itaguai Sand mining district has an important role in the Rio de Janeiro Metropolitan Region, supplying approximately 70% of the Sand for civil construction. The Sand extraction process removes surface sedimentary layers (with quartz–feldspatic composition), increasing water table in the mined Pit. However, this activity causes some chemical and physico-chemical changes in the water, such as the oxidation of reduced sediments lowering pH values (reaching values 4 concentration (reaching more than 90 mg.l − 1 ). The relatively low pH values of those waters promote an increase of weathering rate, especially the silicate minerals and, as a consequence, high Al concentrations (> 10 mg.l − 1 ) are obtained. Four Sand Pit lakes and four wells located close to each other were sampled from November 2005 to March 2007. The groundwater physico-chemical parameters and the dissolved species in the Sand Pit lakes are controlled by Sand extraction process as well as the rainfall regime. During dry season the reduced sediments become exposed by the water table drawdown, promoting oxidation which releases H + and other ions present in those lithologies. The increase of water table during wet season induces lithologies lixiviation, increasing the concentration of dissolved species in groundwater. However it also promotes a decreasing of pH values due to the diluting factor induced by rainwater infiltration. During dry season, the Sand Pit lakes have high pH values due to buffering action caused by the dissolved species present, leading to the ion shielding for H + , caused by evapoconcentration process (high ionic strength for this season). The evapoconcentration conditions along that season promote the preciPitation of some complex salts of Na + , Mg 2 + , Cl − and sulfate, decreasing the concentrations of major dissolved species. The opposite occurs during wet season, where pH values increase due the rainwater input, breaking the ion shielding (lower ionic strength) and dissolving some preciPitated compounds (increasing the concentrations of major dissolved constituents). PHREEQC and WATEQ4F modeling were used for Sand Pit lakes and groundwater samples in order to show the Al behavior in these specific environments, which could be a limiting factor for an aquaculture activity towards the end of mining activities. The Sand Pit lakes showed Al 3 + as the main dissolved species in both dry and wet season, while groundwater presented Al(OH) 2 + and Al(OH) 2 + , which are the most toxic species for aquatic life. The dissolved aluminum concentration in the studied environments was considered by the minerals formation, which the SO 4 2 − salts complex are the main Al scavengers, followed by the silicate minerals in both seasons. The information provided by this study gives an insight to the conditions of aquaculture in Sand Pit lakes, having peculiar characteristics. On the other hand, the dissolved aluminum should be considered in groundwater due to the possible water contamination, considering that wells used for water consumption are prevalent in the region.
