Publications by authors named "Valquiria Maria de Carvalho Aguiar"

Harbours are located in major urban centres around the world and are of great economic importance to the cities in their surroundings. However, the intense traffic of boats and ships can generate environmental impacts that can directly affect the local biota as well as the population that lives in surrounding areas. Therefore, this work aimed to analyse the surface sediment of the Niterói Harbour using chemical, biological and micropalaeontological tools to investigate the environmental condition of this important harbour in Rio de Janeiro State.

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Bottom sediment quality from the Niterói harbor at Guanabara Bay (Rio de Janeiro, Brazil) was evaluated based on concentrations of organic phosphorus (OP) and inorganic phosphorus (IP) and bioavailability of trace metals through BCR fractionation analysis (Zn, Cu, Pb, Cr, Ni, Cd). The study area revealed elevated concentrations of fine sediments and organic matter (TOC: 2.26-7.

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The present study deals with bioavailability of trace metals in the Doce river continental shelf, southeast of Brazil. The bottom sediments of the study area were firstly sampled a few weeks before the biggest environmental disaster of Brazil, the collapse of the Fundão dam in November of 2015. The disaster released around 40 Mm of iron ore tailings into Doce river basin and an estimate of 10 Mm reached the river delta, having the adjacent continental shelf as the final destination.

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Three-stage sequential extraction BCR was applied to surface sediments from the west part of Guanabara Bay to assess the mobility of Zn, Cu, Pb, Ni, Cr, and Mn. Results were satisfactory for the analysis of certificate standard material (BCR 701), with recoveries between 71 (Cu) and 123% (Cr). Evaluation of organic matter composition classified the area as eutrophic (CHO:PRT > 1), with aged organic detritus at some stations.

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Total concentrations of Ni, Cr, Cu, Pb and Zn were determined in surface sediments from 30 stations in Guanabara Bay in 1999 and 2008. An approach using various environmental indices was used to assess contamination status of metals. This approach allowed the comparison with different coastal areas.

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Article Synopsis
  • Four streams in São Gonçalo were studied for their contribution of nutrients to Guanabara Bay, part of a government initiative to reduce pollution.
  • The streams were found to be hyper-eutrophic, with extremely high phosphate levels and nitrogen limiting primary production as indicated by their nutrient ratios.
  • Additionally, the streams experienced severe low oxygen conditions and high suspended particulate matter, making them significant contributors to the eutrophication problem in Guanabara Bay.
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