Gabriela Garcia | NATIONAL UNIVERSITY OF CORDOBA (ARGENTINA) (original) (raw)

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Papers by Gabriela Garcia

Research paper thumbnail of Natural and anthropic perturbations to the chemical composition of the Colorado River (Tucum�n, Argentina)

Environmental Geology, 2004

Economic and urban development in the province of Tucumán is closely associated with its hydrolog... more Economic and urban development in the province of Tucumán is closely associated with its hydrological network. In spite of the regulatory efforts to preserve the quality of the water resources, the lower basins of the majority of the rivers are contaminated with organic effluents derived from sugar-mill and citrus industry. In this paper, the conditions of the Colorado River basin are described. At its headwater, the lithology and geology determine the chemical composition. Calcite and gypsum dissolution and silicate influence water composition, which is slightly perturbed a few kilometers downstream by geothermal waters discharged by a tributary. Close to the discharge into the Salí River, the Colorado River receives a high organic matter load from the highly polluted Calimayo stream, which produces an increase in the organic matter and depletion of dissolved oxygen with redox conditions that promote the reduction of sulfate to sulfide.

Research paper thumbnail of Geochemistry of groundwater in the alluvial plain of Tucum�n province, Argentina

Hydrogeology Journal, 2001

The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. ... more The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. It is located in the southeastern part of the province of Tucumán, northwestern Argentina, and its groundwater resources are developed for water supply and irrigation. The chemical composition of the water is strongly influenced by the interaction with the basinal sediments and by hydrologic characteristics such as the flow pattern and time of residence.

Research paper thumbnail of Solar light induced removal of arsenic from contaminated groundwater: the interplay of solar energy and chemical variables

Solar Energy, 2004

The removal of arsenic by solar oxidation in individual units (SORAS) is currently being explored... more The removal of arsenic by solar oxidation in individual units (SORAS) is currently being explored as a possible economic and simple technology to treat groundwater in Bangladesh and India. Hydroarsenicism affects also large regions of America, especially Argentina, Chile, Mexico and Peru. In this paper, the efficiency of arsenic removal by solar oxidation coupled with precipitation of iron (hydr)oxide, was assessed under various experimental conditions, both on samples of synthetic water and of groundwater of the province of Tucumán (Argentina). The results demonstrate that the underlying chemistry is very complex, and the efficiency is affected often in unpredictable ways by changes in the chemical matrix, or by changes in the operative conditions. Oxides generated from ferrous salts are more efficient than solids formed by hydrolysis of Fe(III); alkalinity contents (bicarbonate) is also important to permit the adequate precipitation. Addition of small amounts of citric acid (lemon juice) is beneficial, but at larger concentrations the effect is negative, probably because of interference in the formation of the solid. The effect of solar irradiation is variable, depending on the other experimental conditions. Although it is possible to remove As partially without solar irradiation under certain special conditions, a procedure versatile enough to cope with waters of different compositions must be based in the use of solar energy. Light plays the role of accelerating the oxidation of As(III) to As(V), and also affects 0038-092X/$ -see front matter Ó the nature of the solid and, hence, its sorptive properties. The rationale of the effect of light is therefore appreciably more complex than in the case of heterogeneous photocatalysis with TiO 2 .

Research paper thumbnail of Chemical behavior of the Salí River, Province of Tucumán, Argentina

Environmental Geology, 2001

Major ionic composition and other chemical parameters were determined at ®ve sampling stations on... more Major ionic composition and other chemical parameters were determined at ®ve sampling stations on the Salõ Â River (Province of Tucuma Ân, Argentina). The heavy human usage of the river causes increased levels of dissolved ions, from the dissolution of halite and gypsum, and from the weathering of basic sediments. Correlations demonstrate that sodium chloride and sulphate, and calcium carbonate are the main contributors to dissolved ions in the river. In the polluted region, south of the Celestino Gelsi dam, the main source of calcium and sulphate is the dissolution of gypsum. Large amounts of halite are also dissolved. Weathering of biotite, K-feldspar and albite are suggested by the data. Conductivity, dissolved oxygen and organic matter all indicate severe contamination by organic matter (mainly from sugar-cane processing) in the lower course. The data also demonstrate a substantial improvement in water quality before the discharge of the river at the Rõ Âo Hondo dam. Data from the Colorado (a tributary of the Salõ Â River) and Medina rivers are also analyzed and compared.

Research paper thumbnail of Geochemistry of groundwater in the alluvial plain of Tucum�n province, Argentina

Hydrogeology Journal, 2001

The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. ... more The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. It is located in the southeastern part of the province of Tucumán, northwestern Argentina, and its groundwater resources are developed for water supply and irrigation. The chemical composition of the water is strongly influenced by the interaction with the basinal sediments and by hydrologic characteristics such as the flow pattern and time of residence.

Research paper thumbnail of Geochemistry of groundwater in the alluvial plain of Tucumán province, Argentina

Hydrogeology Journal, 2001

The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. ... more The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. It is located in the southeastern part of the province of Tucumán, northwestern Argentina, and its groundwater resources are developed for water supply and irrigation. The chemical composition of the water is strongly influenced by the interaction with the basinal sediments and by hydrologic characteristics such as the flow pattern and time of residence.

Research paper thumbnail of Natural and anthropic perturbations to the chemical composition of the Colorado River (Tucum�n, Argentina)

Environmental Geology, 2004

Economic and urban development in the province of Tucumán is closely associated with its hydrolog... more Economic and urban development in the province of Tucumán is closely associated with its hydrological network. In spite of the regulatory efforts to preserve the quality of the water resources, the lower basins of the majority of the rivers are contaminated with organic effluents derived from sugar-mill and citrus industry. In this paper, the conditions of the Colorado River basin are described. At its headwater, the lithology and geology determine the chemical composition. Calcite and gypsum dissolution and silicate influence water composition, which is slightly perturbed a few kilometers downstream by geothermal waters discharged by a tributary. Close to the discharge into the Salí River, the Colorado River receives a high organic matter load from the highly polluted Calimayo stream, which produces an increase in the organic matter and depletion of dissolved oxygen with redox conditions that promote the reduction of sulfate to sulfide.

Research paper thumbnail of Geochemistry of groundwater in the alluvial plain of Tucum�n province, Argentina

Hydrogeology Journal, 2001

The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. ... more The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. It is located in the southeastern part of the province of Tucumán, northwestern Argentina, and its groundwater resources are developed for water supply and irrigation. The chemical composition of the water is strongly influenced by the interaction with the basinal sediments and by hydrologic characteristics such as the flow pattern and time of residence.

Research paper thumbnail of Solar light induced removal of arsenic from contaminated groundwater: the interplay of solar energy and chemical variables

Solar Energy, 2004

The removal of arsenic by solar oxidation in individual units (SORAS) is currently being explored... more The removal of arsenic by solar oxidation in individual units (SORAS) is currently being explored as a possible economic and simple technology to treat groundwater in Bangladesh and India. Hydroarsenicism affects also large regions of America, especially Argentina, Chile, Mexico and Peru. In this paper, the efficiency of arsenic removal by solar oxidation coupled with precipitation of iron (hydr)oxide, was assessed under various experimental conditions, both on samples of synthetic water and of groundwater of the province of Tucumán (Argentina). The results demonstrate that the underlying chemistry is very complex, and the efficiency is affected often in unpredictable ways by changes in the chemical matrix, or by changes in the operative conditions. Oxides generated from ferrous salts are more efficient than solids formed by hydrolysis of Fe(III); alkalinity contents (bicarbonate) is also important to permit the adequate precipitation. Addition of small amounts of citric acid (lemon juice) is beneficial, but at larger concentrations the effect is negative, probably because of interference in the formation of the solid. The effect of solar irradiation is variable, depending on the other experimental conditions. Although it is possible to remove As partially without solar irradiation under certain special conditions, a procedure versatile enough to cope with waters of different compositions must be based in the use of solar energy. Light plays the role of accelerating the oxidation of As(III) to As(V), and also affects 0038-092X/$ -see front matter Ó the nature of the solid and, hence, its sorptive properties. The rationale of the effect of light is therefore appreciably more complex than in the case of heterogeneous photocatalysis with TiO 2 .

Research paper thumbnail of Chemical behavior of the Salí River, Province of Tucumán, Argentina

Environmental Geology, 2001

Major ionic composition and other chemical parameters were determined at ®ve sampling stations on... more Major ionic composition and other chemical parameters were determined at ®ve sampling stations on the Salõ Â River (Province of Tucuma Ân, Argentina). The heavy human usage of the river causes increased levels of dissolved ions, from the dissolution of halite and gypsum, and from the weathering of basic sediments. Correlations demonstrate that sodium chloride and sulphate, and calcium carbonate are the main contributors to dissolved ions in the river. In the polluted region, south of the Celestino Gelsi dam, the main source of calcium and sulphate is the dissolution of gypsum. Large amounts of halite are also dissolved. Weathering of biotite, K-feldspar and albite are suggested by the data. Conductivity, dissolved oxygen and organic matter all indicate severe contamination by organic matter (mainly from sugar-cane processing) in the lower course. The data also demonstrate a substantial improvement in water quality before the discharge of the river at the Rõ Âo Hondo dam. Data from the Colorado (a tributary of the Salõ Â River) and Medina rivers are also analyzed and compared.

Research paper thumbnail of Geochemistry of groundwater in the alluvial plain of Tucum�n province, Argentina

Hydrogeology Journal, 2001

The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. ... more The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. It is located in the southeastern part of the province of Tucumán, northwestern Argentina, and its groundwater resources are developed for water supply and irrigation. The chemical composition of the water is strongly influenced by the interaction with the basinal sediments and by hydrologic characteristics such as the flow pattern and time of residence.

Research paper thumbnail of Geochemistry of groundwater in the alluvial plain of Tucumán province, Argentina

Hydrogeology Journal, 2001

The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. ... more The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. It is located in the southeastern part of the province of Tucumán, northwestern Argentina, and its groundwater resources are developed for water supply and irrigation. The chemical composition of the water is strongly influenced by the interaction with the basinal sediments and by hydrologic characteristics such as the flow pattern and time of residence.