197 research outputs found

    Trace element patterns in heterogeneous land–sea sediments: a comprehensive study of the Ulla–Arousa system (SW Europe)

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    In the continuum of the land–sea interface, sediment reservoirs are often considered separately. Therefore, integrative research is necessary. This study focuses on sediments throughout the tributaries–river–estuary–ria pathway of the Ulla–Arousa system, aiming to quantify trace element contents, identify land sources, determine background levels, and assess sediment enrichment and contamination states. The elements Al, As, Cr, Cu, Fe, Ni, Pb, Sb, U, and Zn were determined in 78 sediment stations. Two approaches were considered. First, background functions and enrichment factors were estimated using Al or U as the reference element. Second, a statistical study was conducted using distribution analysis, which helped identify trace element sources and their influences throughout the basin. The results revealed two significant sources of trace elements. One source is the amphibolite massif of the Arinteiro Unit, influencing the Brandelos (Cu) and Lañas (Fe) tributaries. Another source is the Deza tributary (As, Sb). However, these alterations do not reach the estuary, where anthropogenic sources (Cr, Cu, Ni) dominate. In the inner Ria of Arousa, only a light Cr enrichment was observed. The integrated study of the Ulla–Arousa system provides valuable patterns to understand and address heterogeneous land–sea systems.Consejo Superior de Investigaciones Científicas | Ref. 20181970Xunta de Galicia | Ref. IN607A2021/04Xunta de Galicia | Ref. ED481D 2023/006Consejo Superior de Investigaciones Científicas | Ref. JAEICU-20-IIM-0

    Uranium as reference element to estimate the background of “Anthropocene” sensitive trace elements in sediments of the land-ocean continuum (Ulla-Arousa, NW Iberian Atlantic Margin)

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    Determining the background is a crucial step in differentiating between natural and anthropogenic components in environmental samples. Geochemical normalization is a standard procedure for determining the background contents of trace elements in sediment samples, which involves the careful selection of a reference element. Aluminum (Al), iron (Fe), and other major, minor, and even trace constituents of sediments are commonly used as reference elements. A suitable reference element should behave conservatively, with contents that are not significantly affected by anthropogenic factors or post-depositional processes. In this study, the performance of uranium as a reference element in sediment samples taken from the Ulla River was tested. The Ulla River drains a mainly granitic basin in the Iberian Atlantic Margin, and samples were collected from headwaters to the coastal area. Iterative least squares simple regression was used to estimate the background contents (as background functions) of six trace elements of environmental concern, including arsenic (As), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn). Uranium demonstrated satisfactory performance with correlation coefficients ranging from approximately 0.7 for Cu to 0.9 for As. The background-estimated contents of the six target elements were in good agreement with several references at different geographical scales, with differences possibly attributed to peculiarities in the local lithology. Thus, uranium can be considered a suitable normalizing element. However, it was tested in a relatively homogenous granitic basin and, like any other reference element, should not be used automatically without empirical corroboration.Xunta de Galicia | Ref. ED481B-2019-066Xunta de Galicia | Ref. IN607A2021/04Universidade de Vigo/CISU

    Inventory and assessment of fluvial potholes to promote geoheritage sustainability (Miño River, NW Spain)

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    The Miño is the most important river in the NW Iberian Peninsula. When it flows through Ourense town (Spain), the attractiveness of the thermal springs hides the importance of the fluvial potholes developed over bedrock. These forms reflect the strength of erosion processes, linked to fluvial incision over time. Potholes have an environmental, didactic, socio-economic and cultural potential. In order to promote their integration within territorial heritage, this research is focused on a place-based knowledge and practice. This study aimed to define the meanings and interests of fluvial potholes, regarding their sustainable uses as georesources and offering fit information for the key social actors to assist territorial development. An inventory of sculpted forms was carried out in an urban reach of the Miño River. After the site diagnosis and form characterisation, a set of fluvial potholes (82 cases) was identified within the thermal area. The assessment of the geomorphological and use/management interests delivered their values as resources for territorial sustainability. Ten potholes, selected from a preliminary list and identified through the methodology, have a potential for education, leisure and recreation. Actions designed to raise awareness of the interests and values of these geodiversity components are also presented.Xunta de Galicia | Ref. ED481A-2015/410Universidade de Vigo | Ref. INOU15-02 G501Deputación de Ourense | Ref. INOU15-02 G50

    Research, management and water values in today’s world

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    This volume of the series Perspectives of Water tries various aspects about the research, planning of uses, management and socio-cultural values of aquatic systems in the contemporary period. The contributions induding analyse the relationship between water and human communities in the workl today from scientific, political, social and cultural perspectives. Water is a natural good indispensable for any human activity whose value must be investigated, known and disseminated (European Council, 1968) taking account its role as a resource for the well-being in the international human rights framework (World Health Organization, 2003; United Nations, 2010). The protection, improvement and rational management of aquatic systems are also goals of sustainable development into the future, defined by Agenda 2030 (United Nations, 2015) where education is seen as a process that favours the creation of innovative solutions for current problems of water. At the same time, the generations of actions for sustainability, especially directed toward the integrated management of water resources, are promoted by the declaration of the 2018-2028 Decade of Action by the Water (United Nations, 2016). In Europe, both protection and sustainable use and management of the waters (continental,transitional, coas tal and groundwater) are regulated by the Directive 2000/60/EC in order to prevent their pollution, protect and/or improve their status, mitigate the effects of floods and droughts, and hdp to ensure a long-term equitable provision. This impulse from the institutional sphere represents an opportunity to prioritize the importance of water as a resource of humanity and highlights the relevance of the ítem to encourage the exchange of ideas and collaboration between researchers, managers and social groups particularly interested in aquatic systems

    Un estudio exploratorio para testar los sedimentos atrapados por marmitas de erosión en ríos sobre roca como indicadores ambientales (NO Macizo Ibérico)

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    The capacity of fluvial potholes to trap sediments, together with the geochemical analysis of their stored sediments for environmental assessment, is an overlooked research topic in small bedrock rivers. The present exploratory study is focused on this issue. It was developed in a small river over rock, in the inland territory of Galicia (NW Iberian Peninsula). The study started from an analysis of the inventoried fluvial potholes to identify suitable forms for sampling, and the collection of sediment samples within them. After this, the determination of the grain texture, mineralogy and content of major and trace elements in sediments were carried out. Potholes with maximum vertical depth from 25 cm to 1 m, located in central and sidewall sectors of the bedrock channel, provided the best conditions for sediment sampling. The sediments collected from six potholes showed predominance of coarse-medium grain size and sand fraction. The rough contents of the major and even trace elements are related with the nature of the more refractory minerals of the bedrock. An adequate sampling strategy, considering grain-size fractions, show potential to use trace elements as environmental indicators.La capacidad de las marmitas fluviales para atrapar sedimentos junto con el análisis de los mismos para la evaluación ambiental es un tema de investigación poco estudiado en el caso de pequeños ríos sobre roca. El estudio exploratorio que se presenta, desarrollado en un pequeño río sobre roca del interior de Galicia (noroeste de la Península Ibérica), está centrado en esta cuestión. El estudio partió del análisis de las marmitas fluviales inventariadas con el objetivo de identificar las formas adecuadas para el muestreo y la recolección de sedimentos en su interior. A continuación, se determinó la granulometría, mineralogía y el contenido de elementos mayoritarios y de elementos traza en los sedimentos. Las marmitas fluviales con profundidad máxima vertical desde 25 cm hasta 1 m, localizadas en el sector central y lateral del canal, presentaron las mejores condiciones para el muestreo de sedimentos. En los sedimentos recolectados en seis marmitas predomina el tamaño de grano grueso-medio y la fracción arenosa. El contenido de elementos mayoritarios y traza está relacionado con la naturaleza de los minerales más refractarios de la roca. Mediante una estrategia de muestreo adecuada, teniendo en cuenta las fracciones granulométricas, muestran potencial en el uso de los elementos traza como indicadores ambientales

    Growth of sculpted forms in bedrock channels (Mino River, Northwest Spain)

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    A total of 216 sculpted forms were registered on the granitic bedrock of the Miño River, northwest Iberian Peninsula. Analysis of in situ measurements (length, width and depth) revealed three general type-sets: incipient forms, longitudinal furrows and circular pot-holes. Maximum depth and upper radius (at the incision surface) were identified as key variables to mathematically determine the growth rate in each set. Three regression models are presented revealing that the development of the forms depends on a power law explaining their size and shape. Morphological and dimensional thresholds were established to better identify stages from incipient active growth) and inherited (stationary growth) form

    Anxiety, depression and coping in patients with testicular cancer treatment and follow-up period

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    Introducción: El cáncer de testículo (CT) constituye la neoplasia más común entre los 15 y 39 años. Debido a su incidencia cada vez mayor y a su alta tasa de supervivencia, la literatura se ha centrado en el impacto que puedan tener las secuelas del tratamiento a mediano y a largo plazo. El CT y su asociación con la ansiedad y la depresión constituyen problemas psicológicos frecuentes durante el tratamiento y periodo de seguimiento, en este contexto el afrontamiento ante la enfermedad puede representar un mecanismo de mejor adaptación psicológico. Objetivo: Identificar y comparar los niveles de ansiedad y depresión en pacientes en tratamiento y periodo de seguimiento; así como su relación con los diferentes estilos de afrontamiento positivo. Método: 49 pacientes en tratamiento y 84 en periodo de seguimiento del Instituto Nacional de Cancerología. Se empleo un diseño transversal, no experimental y ex-post-facto. Se utilizaron los Inventarios de Ansiedad de Beck –BAI–, el Inventario de Depresión de Beck –BDI–, y el Instrumento de afrontamiento al estrés de Lazarus y Folkman. Resultados: Se identificaron mayores niveles de ansiedad y depresión en el grupo de pacientes en tratamiento. Se identificó una relación inversamente proporcional entre los estilos de afrontamiento positivos y menores niveles de sintomatología ansiosa y depresiva en ambos grupos. Conclusiones: Se corrobora la asociación entre los estilos de afrontamiento positivos y niveles bajos de ansiedad y depresión. Se recomienda promover en el paciente con CT afrontamiento positivo durante el tratamiento y periodo de seguimiento.Background: Testicular cancer is the most common malignancy between 15 and 39 years old. Due to the increasing incidence and high survival rate of patients with testicular cancer (CT), literature has focused on the impact that may have the aftermath of medium and long term treatment. The CT and its association with anxiety and depression are common psychological problems, in this context, active coping with this disease may represent a psychological best adaptation mechanism. Objective: To identify and compare the levels of depression and anxiety in patients in treatment and follow-up period; as well as his relationship with positive coping styles. Participants and methods: 49 patients in treatment and follow-up period 84 in the National Cancer Institute follow-up period. It is a transversal, retrospective, not experimental and ex-post-facto. The inventories of Beck Depression –BDI– (1961), the Beck anxiety inventory –BAI– (1988) and the instrument of Lazarus and Folkman (1985) for coping with the stress. Results: Higher levels of anxiety and depression in patients in treatment. If you can identify an inversely proportional relationship between positive coping styles and lower levels of anxious and depressive symptoms in both groups Conclusions: Is confirmed the association between positive coping styles and low levels of depression and anxiety. It is recommended to promote in patients with CT positive coping during treatment and follow-up perio

    Background of u and th in sediments of bedrock rivers

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    The Miño River is a good example of bedrock rivers, where sediment geochemistry is scarcely studied. Its urban reach when passing through the city of Ourense gathers some characteristics that provide interest to its sediments, like scarcity of fine sediments accumulation and the impact of several human activities. Sediments trapped by potholes and other rock cavities were considered. In order to evaluate society-nature interactions through sediment composition it is critical to determine the compositional background (in absence of human alterations), particularly when working with trace elements. This work presents an exploratory assay to determine background in sediments from bedrock rivers by using two uncommon elements, uranium (U) and thorium (Th). To determine their background different statistical techniques were applied in order to set the background composition value and calculate possible enrichments. Background was calculated by simple least squares lineal regression by using Al as independent variable (reference element) resulting in 8.7 mgU kg-1 and 5.6 mgTh kg-1. Enrichments were found in some particular samples and can be attributed to intrinsic microenvironment complexities inside rock cavities

    Mathematical analysis and optimal control of heavy metals phytoremediation techniques

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    In this work we optimize different issues related to phytoremediation techniques for heavy metals removal from shallow water, by means of a combination of mathematical modeling, optimal control of partial differential equations and numerical optimization. We introduce, analyze and solve a 2D mathematical system of nonlinear partial differential equations representing the concentrations of heavy metals, algae and nutrients in large waterbodies. Then, we formulate an optimal control problem related to the optimization of the phytoremediation process. In particular, we determine the minimal quantity of algae to be used in the heavy metals remediation process, and locate the optimal place for such algal mass. We also propose two different full algorithms for computing the numerical solution of the control problem and, finally, we present several numerical results for a realistic case.Ministerio de Economía y Competitividad | Ref. MTM2015-65570-

    Industrial supply of trace elements during the “Anthropocene”: a record in estuarine sediments from the Ria of Ferrol (NW Iberian Peninsula)

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    This work addresses the study of a sediment core retrieved in the estuary of the Grande-de-Xubia River (Ria of Ferrol), which is among the first industrialized areas in the Iberian Peninsula and has links to the shipbuilding industry since 1750. The chemical analysis of trace elements (i.e. As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, V, and Zn) was coupled with 210Pb dating. The results span a period of about 130 years and cover the whole of the 20th century. Trace element anthropogenic fluxes accumulating in the sediments were calculated and show that human inputs are the most important sources for Cu, Cd, Hg and Zn, being, on average, well over the natural loads. The temporal variation in the anthropogenic contaminants allows the identification of four main phases describing the human-natural input interactions, which in chronological order, are: (i) early industrialization, (ii) industrial acceleration or first industrial transition, (iii) industrial collapse, and (iv) an industrial maturity or a second industrial transition.Ministerio de Ciencia e Innovación | Ref. CTM 2011-28792-C02-02Xunta de Galicia | Ref. ED481B-2019-06
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