J.O. SANTOS
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Resumo IPEN-doc 10033 Geostatistical mapping of the concentration of Zn in the Bay of Sepetiba in Rio de Janeiro, Brazil2004 - RIBEIRO, A.P.; FIGUEIREDO, A.M.G.; WASSERMAN, J.C.; SANTOS, J.O.In general, the growth of the economical activities in a country is directly conelated to the increase of pressure on natural systems, leading several authorities and specialists to the discussion of the impacts generated and the main actions to minimize them. Over the last years, such discussions have established new paradigms in the means of production in terms of sustainable growth and preservation of natural resources for future generations. In particular, the concern with the water systems has been great, since those are the ones that are most affected by industrial and domestic activities. Within this confext, this study will approach the contamination with Zn of the Bay of Sepetiba, located in the state of Rio de Janeiro, in the southwest region of Brazil. As a result of the industrial and urban expansion over the last three decades, the region has been rather impacted, particularly with the contamination with Zn, as it has been recorded by several authors. With the purpose of assessing precisely the human action concerning the Zn in the region, the concentrations of this metal were determined by instrumental neutron activation analysis (INAA) in 60 samples geographically referred in a regular network. The distribution and evaluation of the risks due to the contamination with Zn in Sepetiba were investigated through classic statistical techniques and geostatistics. In order to limit the effects of discrepant values and later geostatistical analysis, the data were normalized through a Box-Cox transformation. The parameters of the spatial disfribution of the concentrations of Zn were estimated through the adjustment from the theoretical to the experimental variogram via method of the minimum pondered squares. The mapping of the concentrations of the metal studied in this work was carried out through ordinary kriging. In order to evaluate the quality of the geostatistical analysis, the prection variances maps was designed and the cross-validation was carried out. Aiming at identifying the most critical areas with regards to the confamination with Zn, it was constructed the map of probability of concentration that exceed the contents found in the regions that did not undergo human influence. The results obtained in this study provide precise information to evaluate the risks posed by high concentrations of Znin the Bay of Sepetiba, with the purpose of aiding the authorities in their decisions to effectively control the problem.Resumo IPEN-doc 10401 Mobility of zinc in sediments from Sepetiba bay, Rio de Janeiro2005 - RIBEIRO, A.P.; FIGUEIREDO, A.M.G.; WASSERMANN, J.C.; SANTOS, J.O.Resumo IPEN-doc 18962 Concentration attenuation model to assess arsenic, antimony, chromium, selenium and zinc mobility in sediments from Sepetiba Bay, Rio de Janeiro2008 - RIBEIRO, A.P.; FIGUEIREDO, A.M.G.; SANTOS, J.O.; WASSERMAN, J.C.This study proposes a new geostatistical approach for the determination of the mobility of As, Cr, Sb, Se and Zn in sediments based on spatial distribution. The sediment samples were collected from the Sepetiba Bay, Rio de Janeiro, Brazil. The Sepetiba region plays an important role to the economy of Brazil, due to its metallurgical industries and of the Itaguai Harbor. This bay is an example of an aquatic system that has been suffering from severe impact by human occupation and industrial activity in its basin. Total concentrations were determined by using Instrumental Neutron Activation Analysis. The results obtained showed that As, Cr and Se presented higher concentrations close to the Itacuruçá Island (northwest), a region where tourism and small shipyard activities are important. Sb presented a homogeneous distribution along the entire bay. Zn, on the other hand, presented higher concentrations in the northeastern area, close to the mouth of Guandu and Canal de São Francisco rivers, responsible for 95% of the input of fluvial water in the bay. These rivers receive industrial wastes from the industrial park, at about 3 km from the coast. The geostatistical approach (concentration attenuation model) showed that the highest attenuation values for the elements studied are at the same sites where the highest total concentrations were observed. This indicates low mobility of these elements in the Sepetiba bay.Artigo IPEN-doc 10656 Avaliacao da mobilidade de metais e semi-metais em sedimentos coletados em diferentes periodos na Baia de Sepetiba (Rio de Janeiro - Brasil)2005 - CORTEZ, V.D.; RIBEIRO, A.P.; FIGUEIREDO, A.M.G.; SANTOS, J.O.; WASSERMANN, J.C.Artigo IPEN-doc 10779 Identificacao de fontes de contaminacao em sedimentos de dundo coletados na Baia de Sepetiba (RJ) por meio de estatistica multivariada2005 - RIBEIRO, A.P.; FIGUEIREDO, A.M.G.; SANTOS, J.O.; CORTEZ, V.D.; WASSERMANN, J.C.Artigo IPEN-doc 12677 Procedimento de fracionamento e modelagem geoestatística para avaliação dos teores, disponibilidade e mobilidade de cobre em sedimentos da Baia de Sepetiba-RJ2007 - RIBEIRO, A.P.; FIGUEIREDO, A.M.G.; SANTOS, J.O.; COTRIM, M.; DANTAS, E.; WASSERMAN, J.C.; SILVA FILHO, E.This work aimed to'assess copper contamination and mobility in sediments from Sepetiba bay. Rio de Janeiro, where an industrial park composed by about 400 plants, basically metallurgical, is responsible for the input of large amounts of metals, releasing their effluents either directly into the bay or through the local rivers. Copper total concentration, the acid-volatile sulfides (AVS) and the concentration of simultaneously extracted metals (ESEM) were determined in 65 sediment samples collected throughout Sepetiba bay. A geostatistical approach, the attenuation of concentrations model, which aims to estimate the metal mobility was employed. The results obtained showed that Cu presented higher concentrations in the northeastern area, near the entrance of the rivers into the bay. The comparison between copper concentrations with the Canandian Sediment Quality Guidelines (TEL and PEL) showed that Cu levels were below PEL, suggesting low probability of toxicological effects to the aquatic organisms. The ratio FSEM/AVS was below I in northeastern region indicating that in this area Cu is trapped in the sediment as sulfide. The geostatistical approach presented the highest attenuation values for Cu in the northeastern region of Sepetiba bay. indicating low mobility of this metal in this region of the bay, suggesting low availability which is in good agreement with the ESEM/AVS results.