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International audienceA combined analysis of seismic and morphological features identified in a set of high-resolution seismic reflection and bathymetric data, shows a systematic relationship between major modern seafloor morphological traces and the basinward migration of Late Pleistocene coastlines along the continental shelf of the Santos basin (Rio de Janeiro State, SE Brazil). Observed fairly continuous and sinuous mid-outer shelf escarpments are related to the sea-level variations and shelf exposure during the Last Glacial cycle. A bathymetric step at - 110 m is an erosional remnant of offlapping detached forced-regressive wedges that spread over 50 km in the shelf-dip direction, probably developed during periods of falling sea level between MIS 3 and 2. A second major escarpment at - 130 m was interpreted as the shoreline during the LGM, at the time of most extensive subaerial exposure of the continental shelf. However, a distal escarpment at - 150 m is expressed as a straight contour feature along the two main shelf-edge embayments that characterize the shelf break. This escarpment is coupled with a basal seaward-inclined and highly eroded ramp, and was interpreted as the erosional action of bottom currents during the last transgression due to the displacement of the southward flowing Brazil Current towards the present-day outer shelf. Previously published articles have regarded the morphological features observed on the modern shelf as indicators of stillstands during the post-LGM transgression. We conclude that, on the contrary, most of these features are actually from earlier parts of the Late Pleistocene and were formed in a regressive scenario under oscillating and relative slow sea-level fall

Resinas poliméricas vêm sendo usadas como materiais alternativos para tratamento de águas oleosas, provenientes da indústria de petróleo, as quais já tenham sido tratadas por métodos convencionais. O objetivo deste trabalho é avaliar o grau de purificação de águas oleosas sintéticas, quando tratadas em colunas de leito fixo empacotadas com resinas poliméricas constituídas por segmentos hidrofílicos e lipofílicos. Foram preparadas águas oleosas sintéticas e a fluorimetria foi utilizada para determinar o teor total de óleos e graxas (TOG) nas amostras de água recém-preparada e após eluição pela coluna. Os resultados mostraram que amostras de água tratadas com a coluna apresentaram valor de TOG não superior a 1% do valor de TOG da água oleosa preparada. Um estudo cinético mostrou que a eficiência de remoção dos contaminantes depende ligeiramente da vazão de eluição do sistema, sendo que valores de desempenho ótimos foram alcançados a uma vazão de 7,0 mL/min. A passagem de um volume de água oleosa de 11.087 vezes o volume do leito da coluna não foi suficiente para atingir a completa saturação do sistema. Ensaios preliminares de regeneração e reutilização da coluna mostraram seu potencial de uso em mais de 1 ciclo de tratamento de água oleosa.

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