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Academic literature on the topic 'Sedimenty'

Author: Grafiati

Published: 4 June 2021

Last updated: 10 February 2022

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Journal articles on the topic "Sedimenty"

Tudurí, Adriana, Leandro Bergamino, Roberto Violante, José Luis Cavallotto, and Felipe García-Rodríguez. "SPATIAL AND TEMPORAL VARIATION IN THE PRESENT AND HISTORICAL SEDIMENTARY ORGANIC MATTER WITHIN THE RÍO DE LA PLATA ESTUARY (SOUTH AMERICA) IN RELATION TO THE SALINITY/TURBIDITY GRADIENT / VARIAÇÃO ESPACIAL E TEMPORAL PRESENTE E HISTÓRICA DA MATÉRIA ORGÂNICA SEDIMENTAR NO ESTUÁRIO DO RÍO DE LA PLATA (AMÉRICA DO SUL) EM RELAÇÃO AO GRADIENTE DE SALINIDADE / TURBIDEZ." Journal of Sedimentary Environments 3, no. 4 (December 23, 2018): 265–79. http://dx.doi.org/10.12957/jse.2018.39152.

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The aim of this study is to examine sedimentary organic matter sources, spatial distribution and temporal variability in a large estuarine system, the Río de la Plata estuary (South America). For this purpose, this work integrates recent and historical carbon and nitrogen isotopes (δ13C, δ15N), total organic carbon, total nitrogen, C/N ratios and sediment grain size analyses along the Río de la Plata estuary. Principal component analysis based on biogeochemical variables and salinity revealed two main biogeochemical contrasting zones, corresponding to the upper and the lower estuary. Such zones are derived from the density gradient observed at the maximum turbidity zone acting as a physical barrier by trapping fine sediments and controlling primary productivity. As a consequence, sedimentary total organic carbon and total nitrogen increase from upper reaches towards lower reaches to attain maximum values under the turbidity gradient due to the presence of fine sediments. On the other hand, C/N ratios display an opposite trend, with higher values in the upper reaches due to a higher influence of continental organic matter. Moreover, Stable Isotope Analysis in R (SIAR) based on δ13C and δ15N reveals that the main organic matter source to the sediment appears to be the continental particulate organic matter and the estimated percentages of terrestrial allochthonous contribution (C3 plants) indicated a decreased contribution towards the lower reaches. The paleoenvironmental analysis shows a change in the sedimentary organic matter composition since 1970 associated to an increased influence of terrestrial organic matter. This trend is related to an increase in the Paraná River flow, which in turn is related to climatic variability (i.e., the polarity change of the Pacific Decadal Oscillation). ResumoO objetivo deste estudo é estimar fontes de matéria orgânica sedimentar, distribuição espacial e variabilidade temporal num grande sistema estuarino, o estuário do Río de la Plata (América do Sul). Este trabalho integra dados atuais e históricos de isótopos de carbono e nitrogênio (δ13C, δ15N), carbono orgânico total, nitrogênio total, relação C/N e granulometria do sedimento ao longo do estuário do Río de la Plata. A análise de componentes principais baseada em variáveis biogeoquímicas e salinidade revelou duas zonas biogeoquímicas contrastantes, correspondentes ao estuário superior e inferior. Tais zonas são definidas por diferenças no gradiente de densidade na zona de turbidez máxima, o qual atua como uma barreira física, causando o aprisionamento de sedimentos finos e influenciando a produtividade primária. Como conseqüência, o carbono orgânico total sedimentar e o nitrogênio total aumentam dos trechos superiores para os trechos inferiores atingindo valores máximos sob o gradiente de turbidez devido à presença de sedimentos finos. Por outro lado, a razão C/N exibe uma tendência oposta, atingindo valores mais elevados no estuário superior devido a uma maior influência da matéria orgânica continental. Os resultados isotópicos de δ13C e δ15N sugerem que a principal fonte de matéria orgânica para o sedimento é a matéria orgânica particulada continental. A contribuição alóctone terrestre (plantas C3) diminui no estuário inferior. A análise paleoambiental mostra uma mudança na composição da matéria orgânica sedimentar a partir de 1970, causada pelo aumento do fornecimento da matéria orgânica terrestre. Essa tendência está relacionada a um aumento no fluxo do Rio Paraná, na sequência de alterações climáticas relacionadas com a mudança de polaridade da Oscilação Decadal do Pacífico.

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Ooi, Jieun Lin, Lee Woen Ean, Bashar S. Mohammed, M. A. Malek, Leong Sing Wong, Chao Wei Tang, and He Qing Chua. "Study on the Properties of Compressed Bricks Using Cameron Highlands Reservoir Sediment as Primary Material." Applied Mechanics and Materials 710 (January 2015): 25–29. http://dx.doi.org/10.4028/www.scientific.net/amm.710.25.

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This research is to investigate the properties of compressed building bricks producedfrom Cameron Highlands reservoir sediment. The particle size distribution of the sediments are graded as silt and sand. The sediments used were as total replacement of the normal soils used in the compressed soil bricks. This paper presents the compilation of experimental brick properties; compressive strength, water absorption, microstructure and heavy metal leachingof the compressed sediment bricks. The experimental results shows that increasing use of reservoir sediments decrease the compressive strength andincrease the water absorption. The heavy metal concentrations of the leachates from the leaching test are all within the regulatory limits. The optimum mix is derives from the compressive strength and the water absorption in which in this research is Mix 4, 70% sedimenta, 20% sedimentb and 10% cement,complying with ASTM C129 – Non Load Bearing Bricks [1].

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Laut, Lazaro, Maria Virgina Alves Martins, Pierre Belart, Maria Lucia Lorini, Iara Clemente, Leandro Nogueira, Anna Juliace, and Luiz Francisco Fontana. "ORGANIC COMPOUNDS AS PROXIES OF THE SEDIMENTARY ENVIRONMENTAL QUALITY OF THE MARICÁ-GUARAPINA LAGOON SYSTEM (SE, BRAZIL)." Journal of Sedimentary Environments 4, no. 2 (June 15, 2019): 159–73. http://dx.doi.org/10.12957/jse.2019.43371.

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Bottom sediment is a natural trap for organic matter and different kinds of pollutants. The accumulation of large amount of organic matter gives rise to the eutrophication of the aquatic ecosystems. The analyses of the quantity and quality of the organic matter (biopolymers) help to determine the trophic status of coastal ecosystems. The Maricá-Guarapina Lagoon System (MGLS) is located in Rio de Janeiro and is composed by four connected lagoons: Maricá, Barra, Padre and Guarapina. It has been suffering impacts due to the intense and uncontrolled property speculation. Based on this problem, this study aimed to characterize the organic matter (OM) amount and quality in sediments and the relation with the impacted areas in this lagoon system. The collected sediment samples were analyzed for geochemical data combined with grain size and physical-chemical environmental parameters of the bottom water. Statistical results evidenced that the sedimentary environment of the MGLS is heterogenous. The organic matter supplied to the MGLS is provided from different sources but the autochthonous contribution (phytoplanktonic productivity and vegetal detritus from the mangrove fringe) prevails. The anthropogenic contribution was more evident in Padre Lagoon, where the sediments had relatively low TOC contents (0.1-0.8%). The MGLS is accumulating mainly aged organic matter. The most impacted zones were found in Guarapina, Barra and Maricá lagoons, in bottoms of fine-grained sediments, with relatively high TOC and labile biopolymeric compounds (proteins, carbohydrates and lipids) contents, which should evolve into an ever-increasing stage of eutrophication. COMPOSTOS ORGÂNICOS USADOS COMO INDICADORES DA QUALIDADE AMBIENTAL SEDIMENTAR DO SISTEMA LAGUNAR MARICÁ-GUARAPINA (SE DO BRASIL)ResumoO sedimento de fundo constitui uma armadilha natural para a matéria orgânica e diferentes tipos de poluentes. O acúmulo de grande quantidade de matéria orgânica dá origem à eutrofização dos ecossistemas aquáticos. Estimativas de quantidade e qualidade da matéria orgânica (biopolímeros) podem ajudar a determinar o estado trófico dos ecossistemas costeiros. O Sistema Lagunar de Maricá-Guarapina (MGLS), localizado no Estado do Rio de Janeiro (SE do Brasil), é composto por quatro lagunas interconectadas: Maricá, Barra, Padre e Guarapina. Este sistema tem sofrido impactos devido à intensa e descontrolada especulação imobiliária. Neste contexto, este estudo teve como objetivo caracterizar a quantidade e qualidade de matéria orgânica (MO) dos sedimentos do MGLS. Foram obtidos dados geoquímicos e confrontados com resultados granulométricos em amostras de sedimentos coletados em 22 estações de amostragem e analisados parâmetros físico-químicos da água. Os resultados estatísticos evidenciaram que o ambiente sedimentar do MGLS é heterogêneo. Este sistema recebe matéria orgânica de diferentes fontes, sendo, porém, prevalecente a contribuição autóctone (produtividade fitoplanctônica e detritos vegetais dos manguezais existentes na região). A contribuição antropogênica de matéria orgânica foi mais evidente na Lagoa do Padre, onde os sedimentos apresentaram teores de COT relativamente baixos (0,1-0,8%). As zonas mais impactadas foram encontradas em fundos de sedimentos finos, com teores relativamente elevados de COT e de compostos biopoliméricos lábeis (proteínas, carboidratos e lipídios), nas lagunas de Guarapina, Barra e Maricá. Os resultados obtidos revelam também que o MGLS está acumulando principalmente matéria orgânica envelhecida e permitem prever que as referidas áreas podem evoluir para um estágio de cada vez maior grau de eutrofização.Palavras-chave: Lagunas Costeiras Tropicais. Biopolímeros. Eutrofização. Dinâmica Sedimentar.

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Rosa, Kátia Kellem da, Rosemary Vieira, and Jefferson Cardia Simões. "Identificação de Mudanças Ambientais Através da Caracterização Sedimentar e Investigação de Processos Glaciogênicos e Paraglaciais no Ambiente Glacial da Geleira Wanda, Ilha Rei George, Antártica (Identification of Environmental Change Through...)." Revista Brasileira de Geografia Física 6, no. 1 (July 17, 2013): 029. http://dx.doi.org/10.26848/rbgf.v6i1.232807.

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Este estudo objetiva identificar as características sedimentares associadas aos depósitos glaciogênicos e sedimentos com modificação por processos não glaciais na área proglacial da geleira Wanda, Ilha Rei George, Antártica. A metodologia foi desenvolvida através de atividades de campo realizadas durante a estação de verão em 2007, 2010 e 2011. Os sedimentos foram analisados para determinar a distribuição granulométrica e características morfoscópicas. Este estudo apresenta resultados de interpretações dos sedimentos coletados na proglacial da geleira Wanda. A análise sedimentar possibilita a distinção de sedimentos glaciogênicos e dos sedimentos modificados por atividade paraglacial, podendo evidenciar mudanças ambientais em decorrência do aumento da temperatura atmosférica superficial e da precipitação líquida. AbstractThis study arms identify sediment characteristics related to glaciogenics deposits and modification with paraglacial processes in Wanda Glacier proglacial area, King George Island, Antarctica. The methodology was developed through field activities performed during summers in 2007, 2010 and 2011. The sediments were analyzed to determine the particle size distribution and morphoscopical characteristics. This study presents results of the samples sediment interpretation in Wanda Glacier proglacial area. The sediment analyses provided the discrimination of the glaciogenicssediments and paraglacial modified sediments, and was evidence for environment changes in the study area due to the increase surface atmospheric temperature and liquid precipitation.

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Pinto, Anita Fernandes Souza, José Carlos Martins Ramalho, Leonardo Borghi, Thiago Gonçalves Carelli, Josiane Branco Plantz, Egberto Pereira, Denise Terroso, et al. "BACKGROUND CONCENTRATIONS OF CHEMICAL ELEMENTS IN SEPETIBA BAY (SE BRAZIL)." Journal of Sedimentary Environments 4, no. 1 (March 25, 2019): 108–23. http://dx.doi.org/10.12957/jse.2019.40992.

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This study intends to evaluate baseline concentrations of chemical elements for unpolluted sediments of Sepetiba Bay (SE Brazil). It analyzes the concentrations of potentially toxic elements (PTE) and other chemical elements (by Inductively Coupled Plasma Mass Spectrometry and Inductively Coupled Plasma Emission Spectrometry) from the upper part of the SP2 drillcore (or 2-SPT-1-RJ; with 50.30 m length), collected on the margins of Sepetiba Bay (at latitude 22° 55'S and longitude 43° 46'W). This core was described and sampled. Textural, mineralogical and geochemical analyses were performed in 17 sediment levels. The sediment layers of interest were selected, considering the period in which they were deposited, before high anthropic influence in the area, and on sediment grain-size. Only the muddy levels were selected, since fine sediments generally tend to have higher elemental concentrations. Foraminiferal occurrence was also analyzed in the selected layers. The results indicate that the studied sediments were deposited in a transitional marine context, after being exposed to multiple sedimentary cycles and weathering. The baseline concentrations, related to natural sediment sources were estimated for As, Cd, Co, Cr, Cu, Ni, Pb, Zn) and P and for other chemical elements. These results are useful in environmental impact assessment not only in the study area, but also for other coastal regions of Rio de Janeiro State. TÍTULO: CONCENTRAÇÕES DE FUNDO DE ELEMENTOS QUÍMICOS NA BAÍA DE SEPETIBA (SE BRASIL) RESUMO:Este estudo pretende avaliar as concentrações de fundo de elementos químicos, em sedimentos não poluídos, na Baía de Sepetiba (Se Brasil). Analisa as concentrações de elementos potencialmente tóxicos (PTE) e outros elementos químicos (por Espectrometria de Massa Plasma Acoplada Indutivamente e Espectrometria de Emissão Plasma Acoplada Indutivamente) da parte superior do testemunho SP2 (ou 2-SPT-1 RJ; com 50,30 m de comprimento), coletado nas margens da Baía de Sepetiba (à latitude 22° 55'S e longitude 43° 46'W). Este testemunho foi descrito e amostrado a cada 5 cm. Análises estruturais, mineralógicas e geoquímicas foram realizadas em 17 níveis de sedimentos. Os níveis de interesse foram selecionados, considerando o período em que foram depositados, antes da alta influência antrópica na área, e no tamanho do grão do sedimento. Apenas os níveis de lama foram selecionados, uma vez que os sedimentos finos tendem geralmente a ter maiores concentrações de elementos quimicos. A ocorrência de foraminíferos foi também analisada nas camadas selecionadas. Os resultados indicam que os sedimentos estudados foram depositados num contexto marinho de transição, após serem expostos a múltiplos ciclos sedimentares e a intemperismo. As concentrações de fundo, relacionadas a fontes naturais de sedimento foram estimadas para As, Cd, Co, Cr, Cu, Ni, Pb, Zn) e P e para outros elementos químicos. Esses resultados são úteis para a avaliação de impacto ambiental, não apenas na área de estudo, mas também em outras regiões costeiras do Estado do Rio de Janeiro. PALAVRAS-CHAVE: Multi-indicadores. Sedimentos. Registros Holocénicos. Litoral. Atlântico Sul.

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Alves Martins, Maria Virgínia, Márcia Andréia Da Silva Nunes, Marcio Inacio Alves, Marco Helenio de Paula Alves Coelho, Wellen Fernanda Louzada Castelo, Lucia Maria Lorini, Denise Terroso, et al. "GEOCHEMICAL NORMALIZERS APPLIED TO THE STUDY OF THE PROVENANCE OF LITHOGENIC MATERIALS DEPOSITED AT THE ENTRANCE OF A COASTAL LAGOON. A CASE STUDY IN AVEIRO LAGOON (PORTUGAL) / NORMALIZADORES GEOQUÍMICOS APLICADOS AO ESTUDO DE PROVENIÊNCIA DE MATERIAIS LITOGÉNICOS DEPOSITADOS NA ENTRADA DE UMA LAGUNA COSTEIRA. UM ESTUDO DE CASO NA LAGUNA DE AVEIRO (PORTUGAL)." Journal of Sedimentary Environments 3, no. 2 (June 9, 2018): 74–92. http://dx.doi.org/10.12957/jse.2018.34815.

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The use of geochemical normalizers has been applied in sedimentological studies in several study contexts, such as pollution, diagenetic and provenance assessment. Selected textural and mineralogical data of 137 surface sediment samples were compared by statistical analyses with geogenic elements concentrations normalized by the Al, Be, Ce, Fe, Fe+Al, Li, Rb and Sc aiming to identify the best normalizer to trace different sources of bottom sediments for the Aveiro Lagoon entrance (NW of Portugal). The study area is heterogenous in terms of hydrodynamics and sedimentary processes.The most commonly applied geochemical normalizer for the sediments elemental concentrations has been the aluminum. However, the statistical analyses evidenced that the best normalizer was the scandium, since Principal Components Analysis results have evidenced that the element/Sc values are largely independent of sediment granulometry and thus have allowed the identification of compositional differences not related to grain size. Statistical analyses have also allowed to discriminate groups of stations that: i) trace the entry and exit of mixed sources sediments of the lagoon due to the action of tidal currents; ii) contain materials provided from the erosion of granitoids present mainly along the Douro River basin, located to the north, and transported southward by coastal drift; iii) encompasse sediments provided from the erosion of the Schist–Greywacke Complex crossed by the Vouga River that drains into the inner central zone of the lagoon and; iv) represent an area of sediment accumulation located near the entrance of Mira Channel, where lithogenic materials, provided by mixed lithologies in addition to organic matter, are being deposited. The results of this work contribute to the knowledge of the sedimentary dynamics of the Aveiro Lagoon, a coastal system which is part of a littoral stretch that is being strongly eroded, due to natural and anthropic causes and should be applicable to other coastal systems with similar characteristics. ResumoO uso de normalizadores geoquímicos tem sido aplicado em estudos sedimentológicos em diversos contextos, como por exemplo, de poluição, avaliação diagenética e de proveniência de sediments. Dados texturais e mineralógicos selecionados de 137 amostras de sedimentos superficiais foram comparados através de análises estatísticas com concentrações de elementos geogênicos normalizadas por Al, Be, Ce, Fe, Fe + Al, Li, Rb e Sc. O estudo visou identificar o melhor normalizador para traçar diferentes fontes de sedimentos de fundo para a entrada da Lagoa de Aveiro (NW de Portugal), uma área heterogênea em termos de processos hidrodinâmicos e sedimentares.O normalizador geoquímico mais comumente aplicado em sedimentos tem sido o alumínio. No entanto, as análises estatísticas evidenciaram que o melhor normalizador foi o escândio, uma vez que os resultados da análise de componentes principal evidenciaram que os valores das razões elemento/Sc são amplamente independentes da granulometria sedimentar e permitiram a identificação de diferenças composicionais não relacionadas com o tamanho do grão. Análises estatísticas também permitiram discriminar grupos de estações que: i) traçam a entrada e saída de fontes mistas de sedimentos da laguna, devido à ação das correntes de maré; ii) contêm materiais provenientes da erosão de granitóides presentes principalmente ao longo da bacia do Rio Douro, localizada a norte, e transportados para sul por deriva litoral; iii) contêm sedimentos provenientes da erosão do Complexo Xisto-grauvaquico atravessado pelo Rio Vouga, que desagua na zona central interna da laguna e; iv) representam uma área de acumulação de sedimentos localizada perto da entrada do Canal Mira, onde materiais litogênicos, fornecidos por litologias diversificadas, além de matéria orgânica, estão sendo depositados.Os resultados deste trabalho contribuem para o conhecimento da dinâmica sedimentar da Laguna de Aveiro, um sistema costeiro que faz parte de um trecho litorâneo fortemente erodido, devido a causas naturais e antrópicas and may be applicable to other coastal systems with similar characteristics.

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Kenney, William F., Claire L. Schelske, and Andrew D. Chapman. "Changes in polyphosphate sedimentation: a response to excessive phosphorus enrichment in a hypereutrophic lake." Canadian Journal of Fisheries and Aquatic Sciences 58, no. 5 (May 1, 2001): 879–87. http://dx.doi.org/10.1139/f01-040.

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Historic changes in lake phosphorus (P) loading are often determined in paleolimnological investigations by assessing stratigraphic changes in sediment total P. Polyphosphate (poly-P) in sediments may provide additional information on historic lake trophic status, because phytoplankton store surplus P intracellularly as poly-P when supplies exceed growth requirements. We hypothesize that phytoplankton (i.e., cyanobacteria and diatoms) with stored poly-P can remain intact and viable for many decades after sedimentation and that sedimented poly-P is not geochemically reactive. We tested our hypotheses with sediment cores from Lake Apopka, Fla., U.S.A., where P loading has increased ~7-fold since the 1920s and phytoplankton biomass is nitrogen limited owing to excessive P enrichment. We show that sedimented poly-P is mobilized by sample drying (i.e., becomes water soluble, geochemically reactive, and bioavailable); that anthropogenic P enrichment is expressed in the sediment record as increasing concentrations of poly-P; and that, consequently, sedimentary poly-P is a sensitive indicator of historic excessive P enrichment. Sedimentary poly-P is not geochemically reactive; thus, it represents biological attenuation that may partially ameliorate the effects of excessive P loading.

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Locat, Jacques, and Serge Leroueil. "Physicochemical and geotechnical characteristics of recent Saguenay Fjord sediments." Canadian Geotechnical Journal 25, no. 2 (May 1, 1988): 382–88. http://dx.doi.org/10.1139/t88-039.

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In the spring of 1985 the first goetechnical reconnaissance of recent Saguenay Fjord sediments took place, in which were recorded the two Saint-Jean-Vianney slides of 1663 and 1971. Cores from the upper part of the fjord were tested onboard the ship and in the laboratory. The mineralogy of the recent sediments is like that of the raised marine deposits of the area, except for the organic content, which is higher. The microstructure of the sediment is quite typical of flocculated marine soils. The freshly sedimented soil, in its sedimentary environment, has gained strength and sensitivity (up to 12) in excess of what is usually expected for such material. It has been concluded that the physicochemical characteristics of the sediment, such as depicted by its initial plasticity (before leaching), are first-order parameters in the source of apparent overconsolidation and structuration. Key words: recent sediments, shear strength, sensitivity, consolidation, structuration, microstructure, landslide, physicochemistry, mineralogy.

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Navas-S., G. R., S. Zea, and N. H. Campos. "FLUJO DE NITRÓGENO Y FÓSFORO EN LA INTERFASE AGUA-SEDIMENTO EN UNA LAGUNA COSTERA TROPICAL (CIÉNAGA GRANDE DE SANTA MARTA, CARIBE COLOMBIANO)." CICIMAR Oceánides 18, no. 2 (December 31, 2003): 45. http://dx.doi.org/10.37543/oceanides.v18i2.5.

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. Para evaluar el papel del sedimento sobre la alta producción primaria de una laguna costera tropical, Ciénaga Grande de Santa Marta (Caribe, Colombia), se midió el flujo de nitrógeno y fósforo (inorgánico disuelto, particulado) en la interfase agua-sedimento. Entre 1996 y 1997 se incubaron núcleos de sedimento en el laboratorio y se ubicaron trampas de partículas en campo, en dos estaciones contrastadas por la influencia de aguas dulces y marinas. Los flujos tuvieron una alta variabilidad espacial y temporal pero no mostraron esquemas claros en su dirección e intensidad en relación con las características de los sedimentos o de la columna de agua de las dos estaciones. Esto evidencia una alta heterogeneidad en la naturaleza y actividad de los organismos responsables de los procesos biogeoquímicos. Los sedimentos liberaron en promedio al agua 1643 μmolNm-2d-1 de amonio y 1.3 μmolNm-2d-1 de nitrito, aportando a la columna el 1.90-3.41 % de lo requerido en la producción. En condiciones óxicas normales, el sedimento actuó como sifón del fósforo, absorbiendo en promedio 178 μmolPm-2d-1 disueltos y recibiendo 36277 μmolPm-2d-1 particulados. Pero el fósforo se mantiene en exceso en la columna, en parte, por liberación desde el sedimento en condiciones anóxicas durante florecimientos microalgales masivos. Flux of nitrogen and phosphorus at the water-sediment boundary in a tropical coastal lagoon (Ciénaga Grande de Santa Marta, Colombian Caribbean) To evaluate the role of the sediment in the high primary production of a tropical coastal lagoon, "Ciénaga Grande de Santa Marta" (Caribbean, Colombia), the flux of nitrogen and phosphorous (dissolved, inorganic, particulate) in the water-sediment boundary was measured. From 1996 to 1997 sediment cores were incubated in the laboratory and sediment traps were deployed in the field, in two sites contrasted by the influence of fresh and marine waters. The fluxes were spatially and temporally highly variable but did not show clear patterns in their direction and intensity in relation to the sediment or water column characteristics at the two sites. This evidences a high heterogeneity in the nature and activity of the organisms responsible of the biogeochemical processes. The sediments liberated to the water on average 1643 μmolNm-2d-1 of ammonium and 1.3 μmolNm-2d-1 of nitrite, offering 1.90-3.41 % of the amount required in production. In normal oxic conditions, the sediment acted as a phosphorous sink, absorbing on average 178 μmolPm-2d-1 dissolved and receiving 36277 μmolPm-2d-1 particulate. But the phosphorous is maintained in excess in the column, in part, due to its liberation from the sediment in anoxic conditions during massive algal blooms.

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Dissertations / Theses on the topic "Sedimenty"

Sajner, Pavel. "Hydrodynamická separace sedimentu vodního toku." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228371.

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The dissertation deals with clogging of reservoirs and ponds by redundant sediments which penetrate water system by erosion. It describes methods of extracting pond sediments. It contains measurement of dewatering of sediments on hydrocyclone and design of laboratory hydrocyclone and filter unit. In the conclusion there is design of technology of dewatering sediments which were extracted by wet method by drainage excavator. Numerical simulation of flowing in hydrocyclones is simulated in the CFX programme and dewatering technology is simulated in the CHEMCAD programme.

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Ondrová, Jana. "Hodnocení kalů a sedimentů pomocí testů ekotoxicity." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2013. http://www.nusl.cz/ntk/nusl-216942.

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Sediments and sewage sludges are part of the environment. Sewage sludges are formed in wastewater treatment plants as solid residues after water purification, therefore they have antropogenic origine. Although the sediment are formed by natural processes, humans also contribute to their formation. Sediments and sewage sludges can be a reservoir of a number of contaminants, due to their properties. Utilisation of sediments and sewage sludges as material for recultivation or a natural fertilizer is currently supported. But after application to the land, contaminants can be released to the environment. The consideration of ecotoxicological effects of sediments and sewage sludges is very important. Sediments and sewage sludges were ecotoxicologicaly evaluated by bioassays with water leacheate and by whole sediment bioassays. Daphnia magna, Thamnocephalus platyurus, Sinapis alba and Lemna minor were used to perform tests with water leacheate. Heterocypris incongruens, Lactuca sativa and Eisenia fetida were used to perform whole sediment tests.

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Dobešová, Zuzana. "Ekotoxikologické hodnocení sedimentů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-216573.

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Sediments of lotic and lentic water can be a reservoir of a number of contaminants, which can enter the aquatic ecosystem either due to the controlled discharge of waste water or leakage of various accidents or technological devices. Sediments can hereby affect not only the aquatic ecosystem, but also the terrestrial system in the case that they will be used as fertilizer or as a material for the recultivation. For this reason it is important to consider their potential ecotoxicity. Sediments were subjected to ecotoxicological bioassays and their potential ecotoxicity was assessed. The phytotoxicity assays on terrestrial plants Sinapis alba, Lactuca sativa and Allium cepa were used and the effects of aqueous extracts of sediments on the inhibition of growth their root were evaluated and the value of IC50 was determined. For the ecotoxicological assessment of sediments and determination of IC50 value also Lemna minor as a representative of aquatic plants was selected. For more objective assessment of the sediment ecotoxicity aquatic invertebrates as Artemia salina and Daphnia magna were selected and the value of LC50 or EC50 was determined.

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Kratěnová, Pavla. "Zhodnocení vlivu aplikace vytěžených sedimentů z vodního díla Luhačovice na obsah rizikových prvků v orné půdě." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2013. http://www.nusl.cz/ntk/nusl-216976.

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This diploma thesis focuses on an issue concerning an excavated sediment application on an arable soil and its impact on the soil quality based on a particular case of a deposition of the sediment from the dam Luhačovice on an adjacent agricultural area. The theoretical part of this thesis is focused on a soil and sediment characteristics and functions, contained risk elements, sampling methods, determination possibilities of particular risk elements and a description of conditions which emerged from a need for the deposition of sediment obtained during scavenging of the dam Luhačovice. In the experimental part was described the process of sampling, samples processing and determining of concentration values for chosen risk elements (Cd, Cu, Hg, Ni, Pb) using flame or electrothermal atomic absorption spectrometry methods. This part also contains an evaluation of obtained results and a validation of an approval for the sediment deposition.

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Godoi, Ana Carolina. "Remineralização da matéria orgânica sedimentar em resposta à simulação de processos oceanográficos." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/21/21134/tde-09042014-174007/.

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Os sedimentos marinhos são receptores finais de vários compostos da coluna de água, possuindo uma participação ativa nos ciclos biogeoquímicos. Comunidades microbianas possuem um papel crucial nestes ciclos, sendo responsáveis por grande parte da remineralização da matéria orgânica em sedimentos superficiais. Foram realizados dois experimentos com simulações de processos oceanográficos em microcosmos: Enriquecimento Orgânico, testando a diferença entre a chegada de fitoflagelados e diatomáceas no sedimento e Ressuspensão, simulando a passagem de frente fria. Foram analisados os compostos referentes à qualidade e quantidade da matéria orgânica sedimentar, assim como o fluxo de nutrientes da interface água-sedimento. No Experimento Enriquecimento, as diferentes algas causaram respostas distintas nos processos de degradação da matéria orgânica, aumentando a qualidade e o metabolismo das comunidades presentes, além de modificar os fluxos de nutrientes, sendo notada uma resposta mais rápida nos mecanismos de degradação devido à adição do fitoflagelados. No Experimento Ressuspensão, o distúrbio físico ocasionou uma resposta imediata e significativa na liberação dos nutrientes do sedimento para a interface água-sedimento e alterações nas concentrações de ácidos graxos, principalmente nos dois primeiros dias após a simulação. Logo, os diferentes eventos oceanográficos simulados comprovaram sua influência frente aos processos biogeoquímicos, principalmente na disponibilidade de ácidos graxos e na liberação de nutrientes para a água sobrejacente
Marine sediments are the final receivers of many organic compounds from the water column, playing an important role in biogeochemical cycles. Microbial communities are important to these cycles as they remineralize organic matter within surface sediments. Microcosm experiments were conducted to simulate two important oceanographic processes: Organic Enrichment, to test differences between sinking patterns of phytoflagellates and diatoms and Resuspension, simulating the passage of a cold front. The quality and amount of the organic matter was assessed, as well as the nutrient flow between the sediment-water interface. In the Enrichment Experiment, distinctive responses in the degradation processes were noted between treatments where the addition of phytoflagellates increased the quality of the organic matter, caused faster metabolism communities present in the sediment, and modify the patterns of nutrient flux rates. In the Resuspension Experiment, the physical disturbance caused an immediate and significant release of nutrients from the sediment to the sediment-water interface and changed the in the concentrations of fatty acid content most notably during two days after the resuspension event. Thus, the different simulated oceanographic events influenced biogeochemical processes, particularly in the availability of fatty acids and the release of nutrients to the overlying water

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Kurfürst, Vlastimil. "Monitoring kontaminace vod a sedimentů po těžbě uranové rudy." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2011. http://www.nusl.cz/ntk/nusl-216696.

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This paper deals with the monitoring of water contamination and sediments in the area of Olší - Drahonín. Firstly, the water contamination released into the river Hadůvka is evaluated. Secondly, the sediments in the river are monitored and the surface water flow is evaluated. Finally, the water treatment technology and sampling is described. A description of the separation methods and choice of standard methods is outlined.

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Kovaříková, Vladěna. "Vývoj gelových technik pro in situ měření biodostupných forem kovů v půdách a sedimentech." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-233310.

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The doctoral thesis deals with usage of gel techniques for in situ measurement of bioavailable metals in soils and sediments. The DGT technique was applied to soil samples from the localities of Zlín, Tuřany and Chrlice for estimation of bioavailable metals in soils. These soils were amended by sewage sludges in years 1980-1987. The experiment using diffusive gels with different pore size, APA and RG gels, has shown that the DGT can be used for assessment of trace metal soil complexes - small inorganic and larger organic. The results obtained by DGT measurements were approximately up to two orders of magnitude lower than metal concentrations obtained by leaching with sodium nitrate. The leaching with sodium nitrate does not provide true reflection of metal availability to plant root system and soil microorganisms and the DGT technique seems to be a better predictor of metal bioavailability. Only small differences between undisturbed and homogenized soil samples were found out by application of DGT to soil samples from localities of Veverská Bítýška and Ostrovačice. The undisturbed soil is not homogenous and the DGT unit gives information only about the part of the soil which is in direct contact with the unit. The procedure with soil slurry can be recommended for the characterization of large soil areas and estimation of bioavailable metals in soils. Gel techniques were also used for the study of processes occuring in sediments. Mercury species and other metals were analysed in surface water, pore water and sediments collected from two sampling sites in the Dele River in northern France. This river had been polluted during the last century by the activity of Métaleurop factory, which dealt with metal ore treatment. The application of DGT technique using two specific ion-exchange resins, Chelex-100 and Duolite GT-73, provided assessment of mercury in sediment pore water. DGT and DET techniques together with centrifugation provided also high resolution depth profiles of Fe, Mn, Zn, Pb, Cr and Cd in pore water. It is not possible to determine which sampling site was more contaminated. Only small differences in mercury species and metal content were observed between sampling sites. The Dele River can be classified as contaminated river according to total mercury content in sediments and as slightly contaminated river from the point of view of methylmercury content. Correlations between mercury species and sulphide content confirm that total mercury and sulphide content count among factors influencing the mercury release to pore water and controlling processes of methylation and demethylation. Only low toxicity of sediment slurries was found out by the bioluminiscence test with Vibrio fischeri. The results of doctoral thesis demonstrate gel techniques as a very good tool in environmental analysis.

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Bušinová, Markéta. "Problematika stanovení cínu v environmentálních matricích." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-216863.

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This diploma thesis deals with the retrieval of the content of tin in environmental media, the circulation in them and possibilities of the determination of tin in the environment. Summarizes available information on the properties of tin and its compounds, the occurrence and circulation of tin in environmental and determination of tin in environmental media, attention is paid to the determination of total tin content using method of ET-AAS. The experimental part is focused on optimization methods of determination for the ET AAS and selection of a suitable extraction procedure for determination of total tin content in soils and sediments. The best procedure for the determination of tin in the ET-AAS was applied to samples of soil, sediment and water. As the optimum matrix modifier was chosen the solution of Pd (NO3)2 in 5% ascorbic acid, the optimum pyrolysis temperature was 1400 °C and atomization temperature 2400 ° C. Neither of extraction procedures examined were found to be an appropriate procedure for the determination of tin in environmental samples and further work is necessary to optimize the method of separation.

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Doležalová, Jana. "Stanovení alkylderivátů rtuti ve vodním ekosystému." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-216536.

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Diploma thesis is oriented on the question of the fate and occurence of mercury and its derivatives in water ecosystems. At first, deep literature review will be worked out. At second, the optimal analytical procedure for the determination of mercury alkylderivatives in water ecosystem compartments will be proposed and verified. At third, real samples from selected water ecosystems will be taken and analyzed.

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Horák, Jan. "Kontaminace rizikovými prvky na Kutnohorsku a možnosti jejího využití v paleoenvironmentálním výzkumu." Doctoral thesis, Česká zemědělská univerzita v Praze, 2016. http://www.nusl.cz/ntk/nusl-259654.

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The dissertation focuses on topic of using risk elements contamination as a stratigraphic marker in palaeoenvironmental research. The contamination is not studied only as itself, but is viewed as a way to analyse and interpret the sedimentary record of historical events. The contamination carries the information about its original place, its original activity, about development of the landscape. The Kutná Hora region (central Bohemia; 49°57'0.170"N, 15°15'59.877"E) is a region of important historic mining and smelting activity. The mining started in 13th century and lasted until half of 16th century. Then only sporadic attempts of renewal were made. Spatially limited mining was renewed in second half of the 20th century. Therefore, it is highly probable to find here the contaminants in the role of stratigraphic markers. In the research were used mainly As, Be, Cd, Co, Cr, Cu, Hg, Pb, V and Zn as these are the most analysed in contamination studies performed in the region. The aims of the dissertation were to answer these questions: To characterize the contamination - Are some risk elements typical for the contamination originating from the mining and smelting? - If so, is their environmental (spatial, sedimentary) manifestation diversified? - Is possible diversity spatially related to particular landscape features or areas? - Is possible diversity connected to particular activities? To use the answers in analysis of particular sites - Is it possible to use the risk elements contamination as stratigraphic marker in fluvial sediments? - How is the interpretation of particular site influenced by the whole context of regional contamination? The core of the research is the metaanalysis of contamination data coming from region (the data obtained by our research and also from other studies). The results have brought not only basic characteristics of contamination, mainly concentrations. The crucial result was the structure of studied elemental complex. Only As, Cd, Cu, Pb and Zn are connected to contamination originating in mining and smelting. Other elements - their concentrations and spatial distributions - are uninfluenced by mining and smelting activities. More, the information about connection of As and Cd to mining and Cu, Pb and Zn to smelting was revealed. Both groups recorded with different spatial distributions. Also comparison of results by different approaches has shown that some statistical processing (clr-transformation) of such dataset was much better for interpretation than analyses of only concentrations values. We studied also the area of confluence of two rivers - Klejnárka (main river draining contaminated region), which is tributary to Labe (Elbe) river. The contamination is still recognizable here, but the diversity between contamination elements is not. The confluence of rivers strongly dilutes the contaminated material. The concentrations decrease. Also here clr-transformation of data enabled to analyse structures of contaminants spatial distribution unrecognizable by concentrations values. We performed also two vertical profiles analyses. It was shown, that it is highly risky to interpret data of such origin without the complex information about regional contamination context. It was revealed by contextual interpretation of data from one of the profiles, that there is a mixing of geochemical data coming from different statistical populations. The contamination works there as only one of the factors influencing sedimentary record. The site is therefore suitable for statistical testing of two populations mixing, outliers` detection and the like.

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Books on the topic "Sedimenty"

Tóthová, Lívia. Testy toxicity vhodné pre vody a sedimenty. Bratislava: Výskumný ústav vodného hospodárstva, 1999.

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Bühman, C. Sedimentary petrology of coalbearing Ecca sediments. Pretoria: Geological Survey, Dept. of Mineral and Energy Affairs, Republic of South Africa, 1988.

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Einsele, Gerhard. Sedimentary basins: Evolution, facies, and sediment budget. Berlin: Springer-Verlag, 1992.

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Sedimentary basins: Evolution, facies, and sediment budget. 2nd ed. Berlin: Springer, 2000.

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Bedard, D. Laboratory sediment bioassay report on Wheatly Harbour sediments, 1992. [Toronto, Ontario]: Ministry of Environment and Energy, 1995.

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Li, Michael Z., Christopher R. Sherwood, and Philip R. Hill, eds. Sediments, Morphology and Sedimentary Processes on Continental Shelves. Chichester, West Sussex, UK: John Wiley & Sons, Ltd, 2012. http://dx.doi.org/10.1002/9781118311172.

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Hamburg, Germany) Magdeburger Gewässerschutzseminar (2012. Die Elbe und ihre Sedimente: Tagungsband : Magdeburger Gewässerschutzseminar 2012 : 10. und 11. Oktober 2012 in Hamburg = Labe a jeho sedimenty : sbornik : Magdeburský seminář o ochraně vod 2012 : 10. a 11. října 2012 v Hamburku. Magdeburg: Programmkomitee des Magdeburger Gewässerschutzseminars, 2012.

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Hay, Bernward J. Particle flux in the western Black Sea in the present and over the last 5000 years: Temporal variability, sources, transport mechanisms. Woods Hole, Mass: Woods Hole Oceanographic Institution, 1987.

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Drake, Thomas G. Compilation of suspended-load point-transport theories. [Vicksburg, Miss: U.S. Army Engineer Waterways Experiment Station, 1995.

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Rose, William J. Sediment transport, particle size, and loads in North Fish Creek in Bayfield County, Wisconsin, water years 1990-91. Madison, Wis: U.S. Dept. of the Interior, U.S. Geological Survey, 1996.

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Book chapters on the topic "Sedimenty"

Pikelj, Kristina, and Nina Furčić. "Impact of cliff erosion on marine sediment composition - indication of local coastline evolution (Vrgada Island, Croatia)." In Proceedings e report, 462–68. Florence: Firenze University Press, 2020. http://dx.doi.org/10.36253/978-88-5518-147-1.46.

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Erosive coastal cliffs formed in soft-rocks sediments along the generally carbonaceous Eastern Adriatic are a rare feature. The one from the Vrgada Island gave rise to the idea that local seabed surface sediment may reflect the composition of the cliff sediment. First results of sedimentological analyses showed that sediment samples collected on both sides of the cliff contain material eroded mostly from the eastern side of the cliff. Subsequent longshore drift caused by dominant waves likely sort fallen material, transporting its finer fractions to the northern side and further into the sea.

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Perkins, Dexter, Kevin R. Henke, Adam C. Simon, and Lance D. Yarbrough. "Sediments and Sedimentary Rocks." In Earth Materials, 231–72. Leiden, The Netherlands : CRC Press/Balkema, [2019]: CRC Press, 2019. http://dx.doi.org/10.1201/9780429197109-8.

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Okrusch, Martin, and Hartwig E. Frimmel. "Sediments and Sedimentary Rocks." In Springer Textbooks in Earth Sciences, Geography and Environment, 417–52. Berlin, Heidelberg: Springer Berlin Heidelberg, 2020. http://dx.doi.org/10.1007/978-3-662-57316-7_25.

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Chamley, Hervé. "From Sediment to Sedimentary Rock." In Sedimentology, 105–30. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-75565-1_4.

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Ippoliti, Carla, Susanna Tora, Carla Giansante, Romolo Salini, Federico Filipponi, Emanuela Scamosci, Massimo Petrini, Nicola Di Deo, and Annamaria Conte. "Sentinel-2 e campionamenti in situ per il monitoraggio delle acque marine dell’Abruzzo: primi risultati." In Proceedings e report, 557–68. Florence: Firenze University Press, 2020. http://dx.doi.org/10.36253/978-88-5518-147-1.56.

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In this study, the estimate of chlorophyll "a" and the dispersion of sediment in the sea, calculated from Sentinel-2, was compared with real data acquired in situ by a multiparametric probe, along the Abruzzo coast. The ultimate goal is to optimize parameters and algorithms to be able to derive concentration maps of chlorophyll and suspended solids from satellite, taking advantage of the high time frequency and high spatial resolution of the detections. This information is of particular relevance for aquaculture activities, for monitoring water quality and for analyzing sedimentary processes.

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Clarke, John E. Hughes. "Optimal Use of Multibeam Technology in the Study of Shelf Morphodynamics." In Sediments, Morphology and Sedimentary Processes on Continental Shelves, 1–28. Chichester, West Sussex, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118311172.ch1.

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Li, Michael Z., Edward L. King, and Robert H. Prescott. "Seabed Disturbance and Bedform Distribution and Mobility on the Storm-Dominated Sable Island Bank, Scotian Shelf." In Sediments, Morphology and Sedimentary Processes on Continental Shelves, 197–227. Chichester, West Sussex, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118311172.ch10.

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Flemming, Burghard W., and Alexander Bartholomä. "Temporal Variability, Migration Rates and Preservation Potential of Subaqueous Dune Fields Generated in the Agulhas Current on the Southeast African Continental Shelf." In Sediments, Morphology and Sedimentary Processes on Continental Shelves, 229–47. Chichester, West Sussex, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118311172.ch11.

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Duffy, Garret P., and John E. Hughes Clarke. "Measurement of Bedload Transport in a Coastal Sea Using Repeat Swath Bathymetry Surveys: Assessing Bedload Formulae Using Sand Dune Migration." In Sediments, Morphology and Sedimentary Processes on Continental Shelves, 249–71. Chichester, West Sussex, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118311172.ch12.

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Barnard, Patrick L., Li Erikson, David M. Rubin, Pete Dartnell, and Rikk G. Kvitek. "Analyzing Bedforms Mapped Using Multibeam Sonar to Determine Regional Bedload Sediment Transport Patterns in the San Francisco Bay Coastal System." In Sediments, Morphology and Sedimentary Processes on Continental Shelves, 273–94. Chichester, West Sussex, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118311172.ch13.

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Conference papers on the topic "Sedimenty"

Mohr, Henning, Scott Draper, and David White. "Free Field Sediment Mobility on Australia’s North West Shelf." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-11490.

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Under cyclonic conditions, sediment on the North West Shelf (NWS) of Australia may become mobile in shallow water due to classical sediment transport or local liquefaction, and this can affect, for example, the on-bottom stability of subsea pipelines. In this paper, three calcareous sediments sampled from the NWS are analysed, together with realistic metocean data, to illustrate this potential for sediment mobility on the NWS. Specifically, experiments are performed in a recirculating flume (known as an O-Tube) to measure the erosional behaviour and an additional series of experiments are performed using a shaking table, on which each of the sediments have been liquefied and excess pore pressure measurements recorded to back calculate the consolidation coefficient. Soil characterisation data, threshold velocity measurements and shaking table results have then combined to illustrate the potential for sediment mobility for each of the NWS sediments. Best practice models are used to calculate wave and current combined shear stress at the seabed and excess pore pressure accumulation. We find that for these sediments, freshly deposited in laboratory samples, mobility due to sediment transport or liquefaction is very likely in cyclonic conditions on the NWS. Liquefaction is most likely for loosely packed silt, whilst sediment transport is most likely for sand. However, we also show that in more extreme cyclonic conditions there are a subset of sediments that can become mobile due to both sediment transport and liquefaction.

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Vrålstad, Torbjørn, Ragnhild Skorpa, and Arild Saasen. "Rheological Properties of Barite Sediments in Water-Based Drilling Fluids." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78695.

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When a drilling fluid column remains static over a timeframe of several years, the drilling fluid separates into different sediment phases due to gravity separation. These heavy sediments, entitled “settled barite”, are the cause of significant operational problems several years after drilling. An important problem caused by settled barite occurs when performing casing cut-and-pull operations during slot recovery and well abandonment: the casing is “stuck” due to the sediments in the annulus outside the casing. The consistency and rheological properties of the sediments determine how easily the casing is removed. In this paper, we report a preliminary study were we have artificially prepared gravity sediment phases for two different types of water-based drilling fluids; one KCl/polymer-based fluid and one bentonite-based fluid. By studying the rheological properties of the obtained sediment phases, we see that there are considerable differences between the sediments for these different drilling fluids.

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Zhang, Ning, Anpeng He, Jeff Corbino, Paul Schroeder, and Johnathan Bolton. "The Impacts of Confined Disposal Facilities on Calcasieu Ship Channel Sedimentation." In ASME 2013 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fedsm2013-16160.

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The confined disposal facilities (CDFs) are the areas along Calcasieu Ship Channel to store dredged sediments from the ship channel. As the sediments settle in the CDFs, the low concentration sediment flows are discharged into the open water adjacent to the CDFs. The paper demonstrates flow and sediment transport characteristics in the open water due to the CDF discharge. The sediment distributions in all three dimensions in the water are revealed. The lake current effects were also investigated. A commercial CFD package ANSYS-FLUENT is used to simulate all cases in this study.

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Ong, Muk Chen, Lars Erik Holmedal, and Dag Myrhaug. "Numerical Computation of Suspended Sediment Around a Marine Pipeline Close to the Flat Seabed." In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49111.

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The purpose of this paper is to investigate suspended sediment transport around a marine pipeline near the seabed by solving the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations with the standard k-ε model. High Reynolds number flow simulations are considered in the present study. The suspended sediments are seeded upstream of the pipeline. Particle trajectories of the suspended sediments downstream of the pipeline have been visualized by using a Lagrangian approach. Effects of the gap (i.e. the normal distance between the pipeline and the seabed) and the sediment weight (i.e. taking into account sediment settling velocity) have been investigated and discussed.

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Chi, Sang-Bum, Wonnyon Kim, Cheong-Kee Park, Chanmin Yoo, Youngtak Ko, and Jai-Woon Moon. "Relationship Between Manganese Nodule Distribution and Deep-Sea Sediment Properties in the Northeastern Pacific." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83773.

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In order to identify a potential relationship between the spatial distribution of Mn-nodule and deep-sea sediment properties in the Clarion-Clipperton fracture zone of the northeastern Pacific, physico-chemical properties of deep-sea sediments and photos of sea-floor are analyzed. In general, sediment types in the area show dramatic changes with latitude. Compared to the middle sector (8–12°N) covered with biogenic siliceous sediments, the northern (16–17°N) and southern (5–6°N) areas are dominated by pelagic red clays and calcareous sediments, respectively. Such a difference in sediment types probably produces regional-scale variations in Mn-nodule occurrence with latitude (5–17°N) along longitude (131.5°W). According to the photographic examination, manganese nodules are well exposed on the sea floor in the latitude of >8°N. In connection with the dominant oceanic environment, such observation indicates that calcareous sediments cover the diagenic nodules due to higher primary productivity and sedimentation rate in the latitude of <8°N. In addition, sediments in the latitude of 8–12°N show relatively high shear strength. Considering the operation of miner and environmental effect, highly consolidated B2 and C1 areas (8–12°N), showing higher nodule contents and relatively lower primary productivity, are the most plausible site for commercial mining.

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Beemer, Ryan D., Alexandre N. Bandini-Maeder, Jeremy Shaw, Ulysse Lebrec, and Mark J. Cassidy. "The Granular Structure of Two Marine Carbonate Sediments." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-77087.

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Calcareous sediments are prominent throughout the low-latitudinal offshore environment and have been known to be problematic for offshore foundation systems. These fascinating soils consist largely of the skeletal remains of single-celled marine organisms (plankton and zooplankton) and can be as geologically complex as their onshore siliceous counter parts. To enable an adequate understanding of their characteristics, in particular, their intra-granular micro-structure, it is important that geotechnical engineers do not forget about the multifaceted biological origins of these calcareous sediments and the different geological processes that created them. In this paper, the 3D models of soils grains generated from micro-computed tomography scans, scanning electeron microscope images, and optical microscope images of two calcareous sediments from two different depositional environments are presented and their geotechnical implications discussed. One is a coastal bioclastic sediment from Perth, Western Australia that is geologically similar to carbonate sediments typically used in micro-mechanics and particle crushing studies in the literature. The other is a hemipelagic sediment from a region of the North West Shelf of Australia that has historically been geotechnically problematic for engineers. The results show there is a marked difference between coastal bioclastic and hemipelagic sediments in terms of geological context and the associated particle micro-structures. This brings into question whether a coastal bioclastic calcareous sediment is a good micro-mechanical substitute for a hemipelagic one.

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Abduev, M. A. "ANTHROPOGENIC TRANSFORMATION OF THE STOCK OF WEIGHED WEIGHTS OF THE MOUNTAIN RIVERS OF AZERBAIJAN." In Prirodopol'zovanie i ohrana prirody: Ohrana pamjatnikov prirody, biologicheskogo i landshaftnogo raznoobrazija Tomskogo Priob'ja i drugih regionov Rossii. Izdatel'stvo Tomskogo gosudarstvennogo universiteta, 2020. http://dx.doi.org/10.17223/978-5-94621-954-9-2020-60.

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Based on the data of network hydrometric observations over a multi-year period, the transformation of suspended sediments of mountain rivers of Azerbaijan into the stock has been estimated. To quantify the anthropogenic transformation of suspended sediment runoff, we analyzed the dependences of the average annual flow rates of suspended sediment and water, Rg = f (Qg); It was revealed that in connection with the construction of reservoirs, the natural regime of sediment runoff has radically changed.

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Osadchiev, Alexander, Alexander Osadchiev, Peter Zavialov, Peter Zavialov, Vadim Pelevin, and Vadim Pelevin. "METHOD FOR QUANTIFYING ADVECTION, TURBULENT MIXING, AND GRAVITATIONAL SETTLING OF RIVER-BORNE SUSPENDED SEDIMENTS IN COASTAL AREAS FROM THERMOHALINE AND OPTICAL MEASUREMENTS." In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b431548658b.

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This work presents an original method for quantifying advection and turbulent mixing of river-borne suspended sediments. The main idea of the method consists in joint analysis of surface distributions of salinity and sediment concentration in coastal areas influenced by river discharge. Basing on the Lagrangian approach we represent a river plume as a set of individual water particles, which inflow from a river mouth, mix with ambient sea water during their motion within a river plume and finally dissipate. Surface salinity and sediment concentration of a particle provides information about its turbulent mixing with undelaying ambient sea waters and gravitational settling of its sediments respectively during the period from its origin in the river estuary till the moment of measurement. Using these integrated Lagrangian characteristics calculated for the whole study area we reconstruct advection streamlines within the river plume and ratio between turbulent mixing and gravitational settling of river-borne suspended sediments. This method was applied to coastal areas situated in the north-eastern part of the Black Sea and the western part of the Philippine Sea. High resolution thermohaline and sediment concentration data were collected using a pump-through system equipped by a CTD instrument and a turbidity sensor.

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Zhang, Wei, Mingyuan Yang, Xiaolin Zhang, and Peipei Dong. "Study on the Characteristics of Temporal and Spatial Variation of Suspended Sediment in the Pearl River Estuary." In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-79033.

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The Lingding Estuary is one of the main parts of the whole Pearl River Delta, which lies in the South Sea, China. It is about 60 km wide from Hong Kong in the east to Macao in the west and the water areas are approximately 2110 km2. The process of suspended sediment movement is influenced by many factors, such as the estuarine geometry, tidal range and ravine flows etc.. In this paper, large scale hydrological observations in the Lingding Estuary have been respectively carried out in July, 2003. Based on these data, characteristics of temporal and spatial variation of suspended sediment concentration (SSC) in the Lingding Estuary are studied. The research result shows that SSC changes with the variation of tide current and runoff, the sediment re-suspension is often occurred 1–2 hour following the flood or ebb tide. The maximum turbidity appears near the gauging station V3. In the flood dominant stage, the sediments move towards the mainland, while during the ebb sediments move down.

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Reports on the topic "Sedimenty"

Kuehl, Steven A. Extension of Sediment Geochronology to Coarse-Grained Sediments. Fort Belvoir, VA: Defense Technical Information Center, September 2005. http://dx.doi.org/10.21236/ada572615.

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Ding, Yan, Sung-Chan Kim, Rusty L. Permenter, Richard B. Styles, and Jeffery A. Gebert. Simulations of Shoreline Changes along the Delaware Coast. Engineer Research and Development Center (U.S.), January 2021. http://dx.doi.org/10.21079/11681/39559.

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This technical report presents two applications of the GenCade model to simulate long-term shoreline evolution along the Delaware Coast driven by waves, inlet sediment transport, and longshore sediment transport. The simulations also include coastal protection practices such as periodic beach fills, post-storm nourishment, and sand bypassing. Two site-specific GenCade models were developed: one is for the coasts adjacent to the Indian River Inlet (IRI) and another is for Fenwick Island. In the first model, the sediment exchanges among the shoals and bars of the inlet were simulated by the Inlet Reservoir Model (IRM) in the GenCade. An inlet sediment transfer factor (γ) was derived from the IRM to quantify the capability of inlet sediment bypassing, measured by a rate of longshore sediments transferred across an inlet from the updrift side to the downdrift side. The second model for the Fenwick Island coast was validated by simulating an 11-y ear-long shoreline evolution driven by longshore sediment transport and periodic beach fills. Validation of the two models was achieved through evaluating statistical errors of simulations. The effects of the sand bypassing operation across the IRI and the beach fills in Fenwick Island were examined by comparing simulation results with and without those protection practices. Results of the study will benefit planning and management of coastal sediments at the sites.

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Berkowitz, Jacob F., Christine M. VanZomeren, Jaybus J. Price, and Anthony M. Priestas. Incorporating Color Change Propensity into Dredged Material Management to Increase Beneficial Use Opportunities. Engineer Research and Development Center (U.S.), December 2020. http://dx.doi.org/10.21079/11681/39261.

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Dredged materials provide a number of beneficial use opportunities, including beach nourishment, habitat creation and restoration, and other activities. In situ sediment color is important for determining aesthetic and habitat suitability, for beach nourishment, and for other projects. However, dredged materials must meet locally established color compatibility requirements (for example, material cannot be too dark). Often, potential sediment sources are close to meeting specified color thresholds, and previous observations suggest that sediments lighten over time. In response to these observations, this study quantified sediment color change potential in a dredged m aterial management context. Results indicate that dredged material sediment color responded to changes in secondary color components, sediment mixing, and photolytic bleaching improving the sediment color for beneficial use application. Findings allowed for development of a conceptual color change capacity framework and supported development of tools for resource managers to incorporate color change dynamic into planning and operations activities.The following report provides a framework for determining the color change capacity of dredged materials using (1) a comprehensive laboratory approach and (2) a semiquantitative index based on source material and placement location conditions. These tools allow practitioners to incorporate dredged-material color change into resource management decisions, thus increasing beneficial use opportunities.

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Wilkins, Justin, Andrew McQueen, Joshua LeMonte, and Burton Suedel. Initial survey of microplastics in bottom sediments from United States waterways. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/42021.

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Given the reported extent of microplastics in the aquatic environment, environmentally relevant exposure information for sediments dredged by the US Army Corps of Engineers will lend context to the risks posed by this contaminant during dredging. We measured the occurrence, abundance, and polymer composition of microplastics in sediments collected from nine dredged waterways and two non-dredged reference areas. The number of particles in sediment samples ranged from 162 to 6110 particles/kg dry wt., with a mean of 1636 particles/kg dry wt. Fragments were the most prevalent shape observed among the 11 study sites (100% frequency of occurrence), followed by fibers (81%), spheres (75%), foams (38%) and films (34%). Based on analyses of chemical composition of the particles using Fourier transform infrared spectroscopy, polyethylene:propylene was the most common polymer type observed. Consistent with results presented by other investigators microplastic concentrations and polymer types in bottom sediments in this study were also aligned with the most widely used plastics worldwide.

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Scholz, Florian. Sedimentary fluxes of trace metals, radioisotopes and greenhouse gases in the southwestern Baltic Sea Cruise No. AL543, 23.08.2020 – 28.08.2020, Kiel – Kiel - SEDITRACE. GEOMAR Helmholtz Centre for Ocean Research Kiel, November 2020. http://dx.doi.org/10.3289/cr_al543.

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R/V Alkor Cruise AL543 was planned as a six-day cruise with a program of water column and sediment sampling in Kiel Bight and the western Baltic Sea. Due to restrictions related to the Covid-19 pandemic, the original plan had to be changed and the cruise was realized as six oneday cruises with sampling in Kiel Bight exclusively. The first day was dedicated to water column and sediment sampling for radionuclide analyses at Boknis Eck and Mittelgrund in Eckernförde Bay. On the remaining five days, water column, bottom water, sediment and pore water samples were collected at eleven stations covering different types of seafloor environment (grain size, redox conditions) in western Kiel Bight. The data and samples obtained on cruise AL543 will be used to investigate (i) the sedimentary cycling of bio-essential metals (e.g., nickel, zinc, and their isotopes) as a function of variable redox conditions, (ii) the impact of submarine groundwater discharge and diffusive benthic fluxes on the distribution of radium and radon as well as greenhouse gases (methane and nitrous oxide) in the water column, and (iii) to characterize and quantify the impact of coastal erosion on sedimentary iron, phosphorus and rare earth element cycling in Kiel Bight.

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Priestas, Anthony, Brian McFall, and Katherine Brutsche. Performance of nearshore berms from dredged sediments : validation of the Sediment Mobility Tool. Coastal and Hydraulics Laboratory (U.S.), December 2019. http://dx.doi.org/10.21079/11681/34756.

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Bridges, Todd, Sandra Newell, Alan Kennedy, David Moore, Upal Ghosh, Trevor Needham, Huan Xia, Kibeum Kim, Charles Menzie, and Konrad Kulacki. Long-term stability and efficacy of historic activated carbon (AC) deployments at diverse freshwater and marine remediation sites. Engineer Research and Development Center (U.S.), November 2020. http://dx.doi.org/10.21079/11681/38781.

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A number of sites around the United States have used activated carbon (AC) amendments to remedy contaminated sediments. Variation in site-specific characteristics likely influences the long-term fate and efficacy of AC treatment. The long-term effectiveness of an AC amendment to sediment is largely unknown, as the field performance has not been monitored for more than three years. As a consequence, the focus of this research effort was to evaluate AC’s long-term (6–10 yr) performance. These assessments were performed at two pilot-scale demonstration sites, Grasse River, Massena, New York and Canal Creek, Aberdeen Proving Ground (APG), Aberdeen, Maryland, representing two distinct physical environments. Sediment core samples were collected after 6 and 10 years of remedy implementation at APG and Grasse River, respectively. Core samples were collected and sectioned to determine the current vertical distribution and persistence of AC in the field. The concentration profile of polychlorinated biphenyls (PCBs) in sediment pore water with depth was measured using passive sampling. Sediment samples from the untreated and AC-treated zones were also assessed for bioaccumulation in benthic organisms. The data collected enabled comparison of AC distribution, PCB concentrations, and bioaccumulation measured over the short- and long-term (months to years).

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Noshkin, V. E., R. J. Eagle, K. M. Wong, and W. L. Robison. Sediment studies at Bikini Atoll part 2. inventories of transuranium elements in surface sediments. Office of Scientific and Technical Information (OSTI), October 1997. http://dx.doi.org/10.2172/646365.

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WINONA, SPECHT. Issues Relating To Sediment Toxicity Testing And Bioaccumulation Of Persistent Chemicals In SRS Sediments. Office of Scientific and Technical Information (OSTI), March 2005. http://dx.doi.org/10.2172/838803.

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Bennett, Richard H., Kenneth J. Curry, and Matthew H. Hulbert. Seafloor Sediment Environmental Measurements in Support of High Frequency Sound Interaction in Ocean Sediments. Fort Belvoir, VA: Defense Technical Information Center, September 1999. http://dx.doi.org/10.21236/ada630468.

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Academic literature on the topic 'Sedimenty'

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Conference papers on the topic "Sedimenty"

Reports on the topic "Sedimenty"