Radon (222Rn) as Tracer for Submarine Groundwater Discharge Investigation—Limitations of the Approach at Shallow Wind-Exposed Coastal Settings

Mapping radon (222Rn) distribution patterns in the coastal sea is a widely applied method for localizing and quantifying submarine groundwater discharge (SGD). While the literature reports a wide range of successful case studies, methodical problems that might occur in shallow wind-exposed coastal settings are generally neglected. This paper evaluates causes and effects that resulted in a failure of the radon approach at a distinct shallow wind-exposed location in the Baltic Sea. Based on a simple radon mass balance model, we discuss the effect of both wind speed and wind direction as causal for this failure. We show that at coastal settings, which are dominated by gentle submarine slopes and shallow waters, both parameters have severe impact on coastal radon distribution patterns, thus impeding their use for SGD investigation. In such cases, the radon approach needs necessarily to allow for the impact of wind speed and wind direction not only during but also prior to the field campaign

Kit analítico simplificado: uma ferramenta para avaliação massiva da qualidade da água subterrânea

Groundwater resources constitute an important alternative supply. However, the physic - chemical conditions in the subterranean environment favoring the dissolution of some compounds, including iron. This element, when present in excess in the water for residential use can lead to poor quality of life and health. In this context, this paper presents a method for the preparation and handling of a simplified water test kit, optimized for the qualitative determination of dissolved iron in the water. The method principle is based on visual colorimetry, wherein the sample becomes colored by the addition of reactants, allowing the comparison with a color chart and its associated iron levels. The use of this tool can facilitate, for example, making diagnoses of water quality by a massive evaluation of the water used in communities without access to safe water. This water test kit was applied as a diagnostic tool in an area where there is no supply of drinking water, in Rio Grande city - RS. Of the 309 households assessed, on average 47 ± 23% is supplied by rusty water. These results enabled the awareness and mobilization of the residents, as well as the performance of public agencies to develop strategies for improving the quality of water consumed by the population.Os recursos hídricos subterrâneos configuram uma importante alternativa de abastecimento. Porém, as condições físico-químicas no ambiente subterrâneo favorecem a dissolução de alguns compostos, entre eles o ferro. Esse elemento, quando presente em excesso na água para consumo residencial, pode acarretar problemas de qualidade de vida e de saúde. Nesse contexto, o presente trabalho apresenta um método para a elaboração e manuseio de um kit analítico simplificado, otimizado para a determinação qualitativa do ferro dissolvido na água. Esse instrumento é fundamentado na colorimetria visual, na qual a adição de reagentes confere cor à amostra, permitindo sua comparação com uma cartela de cores contendo níveis de contaminação associados aos diferentes tons da cor laranja. A utilização desta ferramenta pode facilitar a elaboração de diagnósticos da qualidade da água, através da avalia- ção massiva da água subterrânea consumida em comunidades desprovidas de água potável canalizada. Este kit analí- tico foi aplicado como ferramenta de diagnóstico em uma área sem suprimento de água potável em Rio Grande - RS. Das 309 residências avaliadas, em média 47±23 % são abastecidas por água ferruginosa. Esses resultados possibilitaram a conscientização e mobilização dos moradores da área, bem como a atuação dos órgãos públicos na elabora- ção de estratégias para a melhoria na qualidade da água consumida pela população

Especiação química de arsênio inorgânico no estuário da Laguna dos Patos (RS, Brasil)

This study optimized and validated a method to perform chemical speciation of inorganic arsenic in water samples collected under the Monitoring Program of the Port of Rio Grande-RS in July and October 2010 from the Laguna dos Patos Estuary (RS, Brazil). The flow injection hydride generation atomic absorption spectrometry technique was employed, allowing quantification of As3+ and As5+ present in estuarine water samples. Data interpretation for results generated using the improved method for analyzing water samples collected from Laguna dos Patos Estuary was done by main components analysis

CHEMICAL SPECIATION OF INORGANIC ARSENIC IN LAGUNA DOS PATOS ESTUARY (RS, BRAZIL)

Submitted by Paula Gautério ([email protected]) on 2014-05-31T15:19:53Z No. of bitstreams: 1 Especiação química de arsênio inorgânico no estuário da Laguna dos Patos (RS, Brasil).pdf: 268780 bytes, checksum: 868015eaf618029b34109b4e868ce420 (MD5)Approved for entry into archive by cristiane soares ([email protected]) on 2014-08-22T17:21:37Z (GMT) No. of bitstreams: 1 Especiação química de arsênio inorgânico no estuário da Laguna dos Patos (RS, Brasil).pdf: 268780 bytes, checksum: 868015eaf618029b34109b4e868ce420 (MD5)Made available in DSpace on 2014-08-22T17:21:37Z (GMT). No. of bitstreams: 1 Especiação química de arsênio inorgânico no estuário da Laguna dos Patos (RS, Brasil).pdf: 268780 bytes, checksum: 868015eaf618029b34109b4e868ce420 (MD5) Previous issue date: 2012This study optimized and validated a method to perform chemical speciation of inorganic arsenic in water samples collected under the Monitoring Program of the Port of Rio Grande-RS in July and October 2010 from the Laguna dos Patos Estuary (RS, Brazil). The flow injection hydride generation atomic absorption spectrometry technique was employed, allowing quantification of As3+ and As5+ present in estuarine water samples. Data interpretation for results generated using the improved method for analyzing water samples collected from Laguna dos Patos Estuary was done by main components analysis

Submarine groundwater discharge revealed by radium isotopes (Ra-223 and Ra-224) near a paleochannel on the Southern Brazilian continental shelf

Submarine Groundwater Discharge (SGD) has been recognized as an important component of the ocean-continent interface. The few previous studies in Brazil have focused on nearshore areas. This paper explores SGD on the Southern Brazilian Continental Shelf using multiple lines of evidence that include radium isotopes, dissolved nutrients, and water mass observations. The results indicated that SGD may be occurring on the Continental Shelf in the Albardão region, near a paleochannel located 50 km offshore. This paleochannel may thus be a preferential pathway for the delivery of nutrient- and metal-enriched groundwater and porewater into continental shelf waters